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The Project Gutenberg eBook of The Earth as Modified by
Human Action
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Title: The Earth as Modified by Human Action
Author: George P. Marsh
Release date: July 1, 2004 [eBook #6019]
Most recently updated: December 29, 2020
Language: English
Other information and formats: www.gutenberg.org/ebooks/6019
Credits: Produced by Steve Harris, Charles Franks and the Online
Distributed Proofreading Team
*** START OF THE PROJECT GUTENBERG EBOOK THE EARTH AS
MODIFIED BY HUMAN ACTION ***
Human Action
This eBook is for the use of anyone anywhere in the United States and most
other parts of the world at no cost and with almost no restrictions
whatsoever. You may copy it, give it away or re-use it under the terms of
the Project Gutenberg License included with this eBook or online at
www.gutenberg.org. If you are not located in the United States, you will
have to check the laws of the country where you are located before using
this eBook.
Title: The Earth as Modified by Human Action
Author: George P. Marsh
Release date: July 1, 2004 [eBook #6019]
Most recently updated: December 29, 2020
Language: English
Other information and formats: www.gutenberg.org/ebooks/6019
Credits: Produced by Steve Harris, Charles Franks and the Online
Distributed Proofreading Team
*** START OF THE PROJECT GUTENBERG EBOOK THE EARTH AS
MODIFIED BY HUMAN ACTION ***
Page 4
Produced by Steve Harris, Charles Franks
and the Online Distributed Proofreading Team.
THE EARTH AS MODIFIED BY
HUMAN ACTION.
A NEW EDITION OF MAN AND NATURE.
BY
GEORGE P. MARSH.
"Not all the winds, and storms, and earthquakes, and seas, and seasons of
the world, have done so much to revolutionize the earth as MAN, the power
of an endless life, has done since the day he came forth upon it, and
received dominion over it."—H. Bushnell, Sermon on the Power of an
Endless Life.
1874.
and the Online Distributed Proofreading Team.
THE EARTH AS MODIFIED BY
HUMAN ACTION.
A NEW EDITION OF MAN AND NATURE.
BY
GEORGE P. MARSH.
"Not all the winds, and storms, and earthquakes, and seas, and seasons of
the world, have done so much to revolutionize the earth as MAN, the power
of an endless life, has done since the day he came forth upon it, and
received dominion over it."—H. Bushnell, Sermon on the Power of an
Endless Life.
1874.
Page 5
PREFACE TO THE FIRST EDITION.
The object of the present volume is: to indicate the character and,
approximately, the extent of the changes produced by human action in the
physical conditions of the globe we inhabit; to point out the dangers of
imprudence and the necessity of caution in all operations which, on a large
scale, interfere with the spontaneous arrangements of the organic or the
inorganic world; to suggest the possibility and the importance of the
restoration of disturbed harmonies and the material improvement of waste
and exhausted regions; and, incidentally, to illustrate the doctrine that man
is, in both kind and degree, a power of a higher order than any of the other
forms of animated life, which, like him, are nourished at the table of
bounteous nature.
In the rudest stages of life, man depends upon spontaneous animal and
vegetable growth for food and clothing, and his consumption of such
products consequently diminishes the numerical abundance of the species
which serve his uses. At more advanced periods, he protects and propagates
certain esculent vegetables and certain fowls and quadrupeds, and, at the
same time, wars upon rival organisms which prey upon these objects of his
care or obstruct the increase of their numbers. Hence the action of man
upon the organic world tends to derange its original balances, and while it
reduces the numbers of some species, or even extirpates them altogether, it
multiplies other forms of animal and vegetable life.
The extension of agricultural and pastoral industry involves an
enlargement of the sphere of man's domain, by encroachment upon the
forests which once covered the greater part of the earth's surface otherwise
adapted to his occupation. The felling of the woods has been attended with
momentous consequences to the drainage of the soil, to the external
configuration of its surface, and probably, also, to local climate; and the
The object of the present volume is: to indicate the character and,
approximately, the extent of the changes produced by human action in the
physical conditions of the globe we inhabit; to point out the dangers of
imprudence and the necessity of caution in all operations which, on a large
scale, interfere with the spontaneous arrangements of the organic or the
inorganic world; to suggest the possibility and the importance of the
restoration of disturbed harmonies and the material improvement of waste
and exhausted regions; and, incidentally, to illustrate the doctrine that man
is, in both kind and degree, a power of a higher order than any of the other
forms of animated life, which, like him, are nourished at the table of
bounteous nature.
In the rudest stages of life, man depends upon spontaneous animal and
vegetable growth for food and clothing, and his consumption of such
products consequently diminishes the numerical abundance of the species
which serve his uses. At more advanced periods, he protects and propagates
certain esculent vegetables and certain fowls and quadrupeds, and, at the
same time, wars upon rival organisms which prey upon these objects of his
care or obstruct the increase of their numbers. Hence the action of man
upon the organic world tends to derange its original balances, and while it
reduces the numbers of some species, or even extirpates them altogether, it
multiplies other forms of animal and vegetable life.
The extension of agricultural and pastoral industry involves an
enlargement of the sphere of man's domain, by encroachment upon the
forests which once covered the greater part of the earth's surface otherwise
adapted to his occupation. The felling of the woods has been attended with
momentous consequences to the drainage of the soil, to the external
configuration of its surface, and probably, also, to local climate; and the
Page 6
importance of human life as a transforming power is, perhaps, more clearly
demonstrable in the influence man has thus exerted upon superficial
geography than in any other result of his material effort.
Lands won from the woods must be both drained and irrigated; river-
banks and maritime coasts must be secured by means of artificial bulwarks
against inundation by inland and by ocean floods; and the needs of
commerce require the improvement of natural and the construction of
artificial channels of navigation. Thus man is compelled to extend over the
unstable waters the empire he had already founded upon the solid land.
The upheaval of the bed of seas and the movements of water and of wind
expose vast deposits of sand, which occupy space required for the
convenience of man, and often, by the drifting of their particles, overwhelm
the fields of human industry with invasions as disastrous as the incursions
of the ocean. On the other hand, on many coasts, sand-hills both protect the
shores from erosion by the waves and currents, and shelter valuable
grounds from blasting sea-winds. Man, therefore, must sometimes resist,
sometimes promote, the formation and growth of dunes, and subject the
barren and flying sands to the same obedience to his will to which he has
reduced other forms of terrestrial surface.
Besides these old and comparatively familiar methods of material
improvement, modern ambition aspires to yet grander achievements in the
conquest of physical nature, and projects are meditated which quite eclipse
the boldest enterprises hitherto undertaken for the modification of
geographical surface.
The natural character of the various fields where human industry has
effected revolutions so important, and where the multiplying population and
the impoverished resources of the globe demand new triumphs of mind over
matter, suggests a corresponding division of the general subject, and I have
demonstrable in the influence man has thus exerted upon superficial
geography than in any other result of his material effort.
Lands won from the woods must be both drained and irrigated; river-
banks and maritime coasts must be secured by means of artificial bulwarks
against inundation by inland and by ocean floods; and the needs of
commerce require the improvement of natural and the construction of
artificial channels of navigation. Thus man is compelled to extend over the
unstable waters the empire he had already founded upon the solid land.
The upheaval of the bed of seas and the movements of water and of wind
expose vast deposits of sand, which occupy space required for the
convenience of man, and often, by the drifting of their particles, overwhelm
the fields of human industry with invasions as disastrous as the incursions
of the ocean. On the other hand, on many coasts, sand-hills both protect the
shores from erosion by the waves and currents, and shelter valuable
grounds from blasting sea-winds. Man, therefore, must sometimes resist,
sometimes promote, the formation and growth of dunes, and subject the
barren and flying sands to the same obedience to his will to which he has
reduced other forms of terrestrial surface.
Besides these old and comparatively familiar methods of material
improvement, modern ambition aspires to yet grander achievements in the
conquest of physical nature, and projects are meditated which quite eclipse
the boldest enterprises hitherto undertaken for the modification of
geographical surface.
The natural character of the various fields where human industry has
effected revolutions so important, and where the multiplying population and
the impoverished resources of the globe demand new triumphs of mind over
matter, suggests a corresponding division of the general subject, and I have
Page 7
conformed the distribution of the several topics to the chronological
succession in which man must be supposed to have extended his sway over
the different provinces of his material kingdom. I have, then, in the
introductory chapter, stated, in a comprehensive way, the general effects
and the prospective consequences of human action upon the earth's surface
and the life which peoples it. This chapter is followed by four others in
which I have traced the history of man's industry as exerted upon Animal
and Vegetable Life, upon the Woods, upon the Waters, and upon the Sands;
and to these I have added a concluding chapter upon Man.
It is perhaps superfluous to add, what indeed sufficiently appears upon
every page of the volume, that I address myself not to professed physicists,
but to the general intelligence of observing and thinking men; and that my
purpose is rather to make practical suggestions than to indulge in theoretical
speculations more properly suited to a different class from that for which I
write.
GEORGE P. MARSH.
December 1, 1868.
PREFACE TO THE PRESENT EDITION.
In preparing for the press an Italian translation of this work, published at
Florence in 1870, I made numerous corrections in the statement of both
facts and opinions; I incorporated into the text and introduced in notes a
large amount of new data and other illustrative matter; I attempted to
improve the method by differently arranging many of the minor
subdivisions of the chapters; and I suppressed a few passages which teemed
succession in which man must be supposed to have extended his sway over
the different provinces of his material kingdom. I have, then, in the
introductory chapter, stated, in a comprehensive way, the general effects
and the prospective consequences of human action upon the earth's surface
and the life which peoples it. This chapter is followed by four others in
which I have traced the history of man's industry as exerted upon Animal
and Vegetable Life, upon the Woods, upon the Waters, and upon the Sands;
and to these I have added a concluding chapter upon Man.
It is perhaps superfluous to add, what indeed sufficiently appears upon
every page of the volume, that I address myself not to professed physicists,
but to the general intelligence of observing and thinking men; and that my
purpose is rather to make practical suggestions than to indulge in theoretical
speculations more properly suited to a different class from that for which I
write.
GEORGE P. MARSH.
December 1, 1868.
PREFACE TO THE PRESENT EDITION.
In preparing for the press an Italian translation of this work, published at
Florence in 1870, I made numerous corrections in the statement of both
facts and opinions; I incorporated into the text and introduced in notes a
large amount of new data and other illustrative matter; I attempted to
improve the method by differently arranging many of the minor
subdivisions of the chapters; and I suppressed a few passages which teemed
Page 8
to me superfluous. In the present edition, which is based on the Italian
translation, I have made many further corrections and changes of
arrangement of the original matter; I have rewritten a considerable portion
of the work, and have made, in the text and in notes, numerous and
important additions, founded partly on observations of my own, partly on
those of other students of Physical Geography, and though my general
conclusions remain substantially the same as those I first announced, yet I
think I may claim to have given greater completeness and a more
consequent and logical form to the whole argument
Since the publication of the original edition, Mr. Elisee Reclus, in the
second volume of his admirable work, La Terre (Paris, 1868), lately made
accessible to English-reading students, has treated, in a general way, the
subject I have undertaken to discuss. He has, however, occupied himself
with the conservative and restorative, rather than with the destructive,
effects of human industry, and he has drawn an attractive and encouraging
picture of the ameliorating influences of the action of man, and of the
compensations by which he, consciously or unconsciously, makes amends
for the deterioration which he has produced in the medium he inhabits. The
labors of Mr. Reclus, therefore, though aiming at a much higher and wider
scope than I have had in view, are, in this particular point, a complement to
my own. I earnestly recommend the work of this able writer to the attention
of my readers.
George P. Marsh
Rome, May 1, 1878.
BIBLIOGRAPHICAL LIST OF WORKS CONSULTED IN THE
PREPARATION OF THIS VOLUME.
translation, I have made many further corrections and changes of
arrangement of the original matter; I have rewritten a considerable portion
of the work, and have made, in the text and in notes, numerous and
important additions, founded partly on observations of my own, partly on
those of other students of Physical Geography, and though my general
conclusions remain substantially the same as those I first announced, yet I
think I may claim to have given greater completeness and a more
consequent and logical form to the whole argument
Since the publication of the original edition, Mr. Elisee Reclus, in the
second volume of his admirable work, La Terre (Paris, 1868), lately made
accessible to English-reading students, has treated, in a general way, the
subject I have undertaken to discuss. He has, however, occupied himself
with the conservative and restorative, rather than with the destructive,
effects of human industry, and he has drawn an attractive and encouraging
picture of the ameliorating influences of the action of man, and of the
compensations by which he, consciously or unconsciously, makes amends
for the deterioration which he has produced in the medium he inhabits. The
labors of Mr. Reclus, therefore, though aiming at a much higher and wider
scope than I have had in view, are, in this particular point, a complement to
my own. I earnestly recommend the work of this able writer to the attention
of my readers.
George P. Marsh
Rome, May 1, 1878.
BIBLIOGRAPHICAL LIST OF WORKS CONSULTED IN THE
PREPARATION OF THIS VOLUME.
Page 9
Amersfoordt, J.P. Het Haarlemmermeer, Oorsprong, Geschiedenis,
Droogmaking. Haarlem, 1857. 8vo.
Andresen, C.C. Om Klitformationen og Klittens Behandling og
Bestyrelse.
Kjobenhavn, 1861. 8vo.
Annali di Agricoltura, Industria e Commercio. Pubblicati per cura del
Ministero d'Agricoltura, Industria e Commercio. Faso i-v. Torino, 1862-'3.
8vo.
Arago, F. Extracts from, in Becquerel, Des Climate.
Arriani, Opera. Lipsiae, 1856. 2 vols. 12mo.
Asbjornen, P.Chr. Om Skoveno og om et ordnet Skovbrug i Norge.
Christiania, 1855. 12mo.
Aus der Natur. Die neuesten Entdeckungen auf dem Gebiete der
Naturwissenschaften. Leipzig, various years. 20 vols. 8vo.
Ave-Lallemant, K.C.B. Die Benutzung der Palmen am Amazonenstrom
in der
Oekonomie der Indier. Hamburg, 1861. 18mo.
Babinet. Etudes et Lectures sur les Sciences d'Obsorvation. Paris, 1855-
1863. 7 vols. 18mo.
Baer, von. Kaspische Studien. St. Petersburg, 1855-1859. 8vo.
Barth, Heinrich. Wanderungen durch die Kustenlander des Mittelmeeres.
V.1. Berlin, 1849. 8vo.
Droogmaking. Haarlem, 1857. 8vo.
Andresen, C.C. Om Klitformationen og Klittens Behandling og
Bestyrelse.
Kjobenhavn, 1861. 8vo.
Annali di Agricoltura, Industria e Commercio. Pubblicati per cura del
Ministero d'Agricoltura, Industria e Commercio. Faso i-v. Torino, 1862-'3.
8vo.
Arago, F. Extracts from, in Becquerel, Des Climate.
Arriani, Opera. Lipsiae, 1856. 2 vols. 12mo.
Asbjornen, P.Chr. Om Skoveno og om et ordnet Skovbrug i Norge.
Christiania, 1855. 12mo.
Aus der Natur. Die neuesten Entdeckungen auf dem Gebiete der
Naturwissenschaften. Leipzig, various years. 20 vols. 8vo.
Ave-Lallemant, K.C.B. Die Benutzung der Palmen am Amazonenstrom
in der
Oekonomie der Indier. Hamburg, 1861. 18mo.
Babinet. Etudes et Lectures sur les Sciences d'Obsorvation. Paris, 1855-
1863. 7 vols. 18mo.
Baer, von. Kaspische Studien. St. Petersburg, 1855-1859. 8vo.
Barth, Heinrich. Wanderungen durch die Kustenlander des Mittelmeeres.
V.1. Berlin, 1849. 8vo.
Page 10
Barth, J.B. Om Skovene i deres Forhold til Nationaloeconomien.
Christiania, 1857. 8vo.
Baude, J.J. Les Cotes de la Manche, Revue des Deux Mondes, 15
Janvier, 1859.
Baumgarten. Notice sur les Rivieres de la Lombardie; in Annales des
Ponts et Chaussees, 1847, 1er semestre, pp. 129-199.
Beckwith, Lieut. Report in Pacific Railroad Report, vol. Ii.
Becquerel. Des Climats et de l'Influence qu'exercent les Sols bolses et
non-boises. Paris, 1858. 8vo.
——Elements de Physique Terrestre et de Meteorologie. Paris, 1847.
8vo.
Belgrand. De l'Influence des Forets sur l'ecoulement des Eaux Pluviales;
in Annales des Ponts et Chaussees, 1854, ler semestre, pp. 1, 27.
Berg, Edmund von. Das Verdrangen der Laubwalder im Nordlichen
Deutschlande durch die Fichte und die Kiefer. Darmstadt, 1844. 8vo.
Bergsoe, A.F. Greve Ch. Ditlev Frederik Reventlovs Virksomhed som
Kongens Embedsmand og Statens Borger. Kjobenhavn, 1837. 2 vols. 8vo.
Berlepsch, H. Die Alpen in Natur-und Lebensbildern. Leipzig, 1862. 8vo.
Bianchi, Celestino. Compendio di Geografia Fisica Speciale d'Italia.
Appendice alla traduzione Italiana della Geog.-Fisica di Maria
Somerville. Firenze, 1861. (2d vol. of translation.)
Bigelow, John. Les Etats Unis d'Amerique en 1868. Paris, 1868. 8vo.
Christiania, 1857. 8vo.
Baude, J.J. Les Cotes de la Manche, Revue des Deux Mondes, 15
Janvier, 1859.
Baumgarten. Notice sur les Rivieres de la Lombardie; in Annales des
Ponts et Chaussees, 1847, 1er semestre, pp. 129-199.
Beckwith, Lieut. Report in Pacific Railroad Report, vol. Ii.
Becquerel. Des Climats et de l'Influence qu'exercent les Sols bolses et
non-boises. Paris, 1858. 8vo.
——Elements de Physique Terrestre et de Meteorologie. Paris, 1847.
8vo.
Belgrand. De l'Influence des Forets sur l'ecoulement des Eaux Pluviales;
in Annales des Ponts et Chaussees, 1854, ler semestre, pp. 1, 27.
Berg, Edmund von. Das Verdrangen der Laubwalder im Nordlichen
Deutschlande durch die Fichte und die Kiefer. Darmstadt, 1844. 8vo.
Bergsoe, A.F. Greve Ch. Ditlev Frederik Reventlovs Virksomhed som
Kongens Embedsmand og Statens Borger. Kjobenhavn, 1837. 2 vols. 8vo.
Berlepsch, H. Die Alpen in Natur-und Lebensbildern. Leipzig, 1862. 8vo.
Bianchi, Celestino. Compendio di Geografia Fisica Speciale d'Italia.
Appendice alla traduzione Italiana della Geog.-Fisica di Maria
Somerville. Firenze, 1861. (2d vol. of translation.)
Bigelow, John. Les Etats Unis d'Amerique en 1868. Paris, 1868. 8vo.
Page 11
Blake, Wm. P. Reports in Pacific Railroad Report, vols. ii and v.
Blanqui. Memoire sur les Populations des Hautes Alpes; in Memoires de
l'Academie del Sciences Morales et Politiques, 1843.
——Voyage en Bulgarie. Paris, 1843. 12mo.
——Precis Elementaire d'Economie Politique, suivi du Resume de
l'Histoire du Commerce et de l'Industrie. Paris, 1857. 12mo.
Boitel, Amedee. Mise en valeur des Terres pauvres par le Pin Maritime.
2d edition. Paris, 1857. 8vo.
Bonnemere, Eugene. Histoire des Paysons depuis la fin du Moyen Age
jusqu'a nos jours. Paris, 1856. 2 vols. 8vo.
Bottger, C. Das Mittelmeer. Leipzig, 1859.
Boussingault, J.B. Economie Rurale consideree dans ses Rapports avec la
Chimie, la Physique, et la Meteorologie. 2d edition. Paris, 1851. 2 vols.
8vo.
Bremontier, N.T. Memoire sur les Dunes; in Annales des Ponts et
Chaussees, 1833, ler semestre, pp. 145, 228.
Brincken, J. von den. Ausichten uber die Bewaldung der Steppen des
Europaeischen Russland. Braunschweig, 1854. 4to.
Buttner, J.G. Zur Physikalischen Geographie; in Berghaus,
Geographisches
Jabrbuch, No. iv, 1852, pp. 9-19.
Caimi, Pietro. Conni sulla Importanza e Coltura del Boschi. Milano,
1857. 8vo.
Blanqui. Memoire sur les Populations des Hautes Alpes; in Memoires de
l'Academie del Sciences Morales et Politiques, 1843.
——Voyage en Bulgarie. Paris, 1843. 12mo.
——Precis Elementaire d'Economie Politique, suivi du Resume de
l'Histoire du Commerce et de l'Industrie. Paris, 1857. 12mo.
Boitel, Amedee. Mise en valeur des Terres pauvres par le Pin Maritime.
2d edition. Paris, 1857. 8vo.
Bonnemere, Eugene. Histoire des Paysons depuis la fin du Moyen Age
jusqu'a nos jours. Paris, 1856. 2 vols. 8vo.
Bottger, C. Das Mittelmeer. Leipzig, 1859.
Boussingault, J.B. Economie Rurale consideree dans ses Rapports avec la
Chimie, la Physique, et la Meteorologie. 2d edition. Paris, 1851. 2 vols.
8vo.
Bremontier, N.T. Memoire sur les Dunes; in Annales des Ponts et
Chaussees, 1833, ler semestre, pp. 145, 228.
Brincken, J. von den. Ausichten uber die Bewaldung der Steppen des
Europaeischen Russland. Braunschweig, 1854. 4to.
Buttner, J.G. Zur Physikalischen Geographie; in Berghaus,
Geographisches
Jabrbuch, No. iv, 1852, pp. 9-19.
Caimi, Pietro. Conni sulla Importanza e Coltura del Boschi. Milano,
1857. 8vo.
Page 12
Cantegril, and others. Extracts in Comptes Rendus a l'Academie des
Sciences. Paris, 1861.
Castellani. Dell' immediata influenza delle Selve sul corso delle acqua.
Torino, 1818, 1819. 2 vols. 4to.
Census of the United States for 1860. Preliminary Report on,
Washington, 1862. 8vo.
Cerini, Giuseppe. Dell' Impianto e Conservazione dei Boschi. Milano,
1844. 8vo.
Champion, Maurice. Les Inondations en France depuis le VIme Siecle
jusqu'a nos jours. Paris, 1858, 1862. Vols. i-iv, 8vo.
Chateauvieux, F. Lullin de. Lettres sur l'Italie. Seconde edition,
Geneve, 1834. 8vo.
Chevandier. Extracts in Comptes Rendus a l'Academie des Sciences.
Juillet-Decembre, 1844. Paris.
Clave, Jules. Etudes sur l'Economie Forestiere. Paris, 1862. 12mo.—-La
Foret de Fontainebleau; Revue des Deux Mondes, 1 Mai, 1868.
Cooper, J. G. The Forests and Trees of Northern America; in Report of
the Commissioner of Patents for the year 1860, pp. 416, 445.
Cotta, Bernhard. Deutschlands Boden. Leipzig, 1858. 2 vols. 8vo.—-
Vorwort zu Paramelle's Quellenkunde. See Paramelle.—-Die Alpen.
Leipzig, 1851. 8vo.
Coultas, Harland. What may be Learned from a Tree. New York, 1860.
8vo.
Sciences. Paris, 1861.
Castellani. Dell' immediata influenza delle Selve sul corso delle acqua.
Torino, 1818, 1819. 2 vols. 4to.
Census of the United States for 1860. Preliminary Report on,
Washington, 1862. 8vo.
Cerini, Giuseppe. Dell' Impianto e Conservazione dei Boschi. Milano,
1844. 8vo.
Champion, Maurice. Les Inondations en France depuis le VIme Siecle
jusqu'a nos jours. Paris, 1858, 1862. Vols. i-iv, 8vo.
Chateauvieux, F. Lullin de. Lettres sur l'Italie. Seconde edition,
Geneve, 1834. 8vo.
Chevandier. Extracts in Comptes Rendus a l'Academie des Sciences.
Juillet-Decembre, 1844. Paris.
Clave, Jules. Etudes sur l'Economie Forestiere. Paris, 1862. 12mo.—-La
Foret de Fontainebleau; Revue des Deux Mondes, 1 Mai, 1868.
Cooper, J. G. The Forests and Trees of Northern America; in Report of
the Commissioner of Patents for the year 1860, pp. 416, 445.
Cotta, Bernhard. Deutschlands Boden. Leipzig, 1858. 2 vols. 8vo.—-
Vorwort zu Paramelle's Quellenkunde. See Paramelle.—-Die Alpen.
Leipzig, 1851. 8vo.
Coultas, Harland. What may be Learned from a Tree. New York, 1860.
8vo.
Page 13
Courier, Paul-Louis. Oeuvres Completes. Bruxelles, 1838. 8vo.
Dana, James D. Manual of Geology. Philadelphia, 1863. 8vo.
Delamarre, L. G. Historique de la Creation d'une Richesse Millionaire
par la culture des Pins. Paris, 1827. 8vo. D. Hericourt, A. F. Les Inondations
et le livre de M. Valles; Annales Forestieres, December, 1857, pp. 310, 321.
Paris.
Diggelen, B. P. G. van. Gruote Werken in Nederland. Zwolle, 1855. 8vo.
Dumas, M. J. La Science des Fontaines. 2me edition, Paris, 1857. 8vo.
Dumont, Aristide. Des Travaux Publics dans leurs Rapports avec
l'Agriculture. Paris, 1847. 8vo.
Dwight, Timothy. Travels in New England and New York. New Haven,
1821. 4 vols. 8vo.
Emerson, George B. A Report on the Trees and Shrubs growing naturally
in
Massachusetts. Boston, 1850. 8vo.
Emory, Wm. H., Col. Report of Commissioners of the United States and
Mexican Boundary Survey, vol. i, 1857.
Escourrou-Miliago, A. L'Italie a propos de l'Exposition Universelle de
Paris. Paris, 1856. 8vo.
Evelyn, John. Silva; or, a Discourse of Forest Trees. With Notes by A.
Hunter. York, 1786. 2 vols. 4to.
——Terra, a Philosophical Discourse of Earth. York, 1786. 4to. in vol. ii
of Silva.
Dana, James D. Manual of Geology. Philadelphia, 1863. 8vo.
Delamarre, L. G. Historique de la Creation d'une Richesse Millionaire
par la culture des Pins. Paris, 1827. 8vo. D. Hericourt, A. F. Les Inondations
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Seneca, L. A. Opera Omnia quae supersont, ex rec. Ruhkopf. Aug.
Taurinorum, 1831. 6 vols. 8vo.
Simonde, J. E. L. Tableau de l'Agriculture Toscane. Geneve, 1801. 8vo.
Smith, Dr. William. A Dictionary of the Bible. London, 1860. 8 vols. 8vo.
——A. Dictionary of Greek and Roman Geography. London, 1854,
1857. 2 vols. 8vo.
Smith, John. Historie of Virginia. London, 1624. Folio.
Somerville, Mary. Physical Geography. Fifth edition. London, 1862.
12mo.
Springer, John S. Forest-Life and Forest-Trees. New York, 1851. 12mo.
Page 23
Stanley, Dr. Lectures on the History of the Jewish Church. London, 1863.
8vo.
Staring, W. H. De Bodem van Nederland. Haarlem, 1856. 2 vols. 8vo.
——Voormaals en Thans. Haarlem, 1858. 8vo.
Stevens, Gov. Report in Pacific Railroad Report, vol. xii.
Strain, Lieut. I.C. Darien Exploring Expedition, by J.T. Headley, in
Harper's Magazine. New York, March, April, and May, 1855.
Streffleur, V. Ueber die Natur und die Wirkungen der Wildbuche. Sitz.
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248.
Strom, Ier. Om Skogarnas Vard och Skotsel. Upsala, 1853. Pamphlet.
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4to.
Tartini, Ferdinando. Memorio sul Bonificamento delle Maremme
Toscane. Firenze, 1888. Folio. Thomas and Baldwin. Gazetteer.
Philadelphia, 1855. 1 vol. 8vo.
Thompson, Z. History of Vermont, Natural, Civil, and Statistical.
Burlington, 1842. 8vo.
——Appendix to History of Vermont. Burlington, 1853. 8vo.
Titcomb, Timothy. Lessons in Life. New York, 1861. 12mo.
Treadwell, Dr. Observations of, quoted from Report of Commissioner of
Patents.
8vo.
Staring, W. H. De Bodem van Nederland. Haarlem, 1856. 2 vols. 8vo.
——Voormaals en Thans. Haarlem, 1858. 8vo.
Stevens, Gov. Report in Pacific Railroad Report, vol. xii.
Strain, Lieut. I.C. Darien Exploring Expedition, by J.T. Headley, in
Harper's Magazine. New York, March, April, and May, 1855.
Streffleur, V. Ueber die Natur und die Wirkungen der Wildbuche. Sitz.
Ber. der M.N.W. Classe der Kaiserl. Akad. der Wis. February, 1852, viii, p.
248.
Strom, Ier. Om Skogarnas Vard och Skotsel. Upsala, 1853. Pamphlet.
Surell, Alexandre. Etude sur les Torrents des Hautes Alpes. Paris, 1844.
4to.
Tartini, Ferdinando. Memorio sul Bonificamento delle Maremme
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Thompson, Z. History of Vermont, Natural, Civil, and Statistical.
Burlington, 1842. 8vo.
——Appendix to History of Vermont. Burlington, 1853. 8vo.
Titcomb, Timothy. Lessons in Life. New York, 1861. 12mo.
Treadwell, Dr. Observations of, quoted from Report of Commissioner of
Patents.
Page 24
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1861. 8vo. pamphlet.
Tschudi, Friedrich von. Ueber die Landwirthschaftliche Bedeutung der
Vogel. St. Gallen, 1854. 12mo.
Tschudi, J.J. von. Travels in Peru. New York, 1848. 8vo.
Valles, M.F. Etudes sur les Inondations, leurs causes et leurs effets.
Paris, 1857. 8vo.
Valvasor, Johann Weichard. Die Ehre des Herzogthums Crain. Laybach,
1689. 4 vols. folio.
Van Lennep. Extracts from Journal of, in the Missionary Herald.
Vaupell, Chr. Bogene Indvandring i de Danske Skove. Kjobenhavn,
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Land.
Groningen, 1854. 8vo.
Villa, Antonio Giovanni Batt. Necessita dei Boschi nella Lombardia.
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Waltershausen, W. Sartorius von. Ueber den Sicilianischen Ackerbau
Gottingen, 1863.
1861. 8vo. pamphlet.
Tschudi, Friedrich von. Ueber die Landwirthschaftliche Bedeutung der
Vogel. St. Gallen, 1854. 12mo.
Tschudi, J.J. von. Travels in Peru. New York, 1848. 8vo.
Valles, M.F. Etudes sur les Inondations, leurs causes et leurs effets.
Paris, 1857. 8vo.
Valvasor, Johann Weichard. Die Ehre des Herzogthums Crain. Laybach,
1689. 4 vols. folio.
Van Lennep. Extracts from Journal of, in the Missionary Herald.
Vaupell, Chr. Bogene Indvandring i de Danske Skove. Kjobenhavn,
1857. 8vo.
——De Nordsjaellandake Skovmoser. Kjobenhavn, 1851. 4to, pamphlet.
Venema, G.A. Over het Dalen van de Noordelijke Kuststreken van ons
Land.
Groningen, 1854. 8vo.
Villa, Antonio Giovanni Batt. Necessita dei Boschi nella Lombardia.
Milano, 1850. 4to.
Viollet, J.B. Theorie des Puits Artesiens. Paris, 1840. 8vo.
Waltershausen, W. Sartorius von. Ueber den Sicilianischen Ackerbau
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Page 25
Webster, Noah. A Collection of Papers on Political, Literary, and Moral
Subjects. New York, 1843. 8vo.
Wessely, Joseph. Die Oesterreichischen Alpenlander und ihre Forste.
Wien, 1853. 2 vols. 8vo.
Wetzstein, J.G. Reisebericht uber Hanran und die Trachonen. Berlin,
1860. 8vo.
Wild, Albert. Die Niederlande. Leipzig, 1862. 2 vols. 8vo.
Wilhelm, Gustav. Der Boden und das Wasser. Wien, 1861. 8vo.
Williams, Dr. History of Vermont. 2 vols. 8vo.
Wittwer, W.C. Die Physikalische Geographie. Leipzig, 1855. 8vo.
Young, Arthur. Voyages en France, pendant les annees 1787, 1788, 1789,
procedee d'une introduction par Lavergne. Paris, 1860. 2 vols. 12mo.
——Voyages en Italie et en Espagne, pendant les annees 1787, 1789.
Paris, 1860. 1 vol. 12mo.
TABLE OF CONTENTS
CHAPTER I.
Subjects. New York, 1843. 8vo.
Wessely, Joseph. Die Oesterreichischen Alpenlander und ihre Forste.
Wien, 1853. 2 vols. 8vo.
Wetzstein, J.G. Reisebericht uber Hanran und die Trachonen. Berlin,
1860. 8vo.
Wild, Albert. Die Niederlande. Leipzig, 1862. 2 vols. 8vo.
Wilhelm, Gustav. Der Boden und das Wasser. Wien, 1861. 8vo.
Williams, Dr. History of Vermont. 2 vols. 8vo.
Wittwer, W.C. Die Physikalische Geographie. Leipzig, 1855. 8vo.
Young, Arthur. Voyages en France, pendant les annees 1787, 1788, 1789,
procedee d'une introduction par Lavergne. Paris, 1860. 2 vols. 12mo.
——Voyages en Italie et en Espagne, pendant les annees 1787, 1789.
Paris, 1860. 1 vol. 12mo.
TABLE OF CONTENTS
CHAPTER I.
Page 26
INTRODUCTORY
Natural Advantages of the Territory of the Roman Empire—Physical
Decay of that Territory—Causes of the Decay—Reaction of Man on Nature
—Observation of Nature—Uncertainty of Our Historical Knowledge of
Ancient Climates—Uncertainty of Modern Meteorology—Stability of
Nature—Formation of Bogs—Natural Conditions Favorable to
Geographical Change—Destructiveness of Man—Human and Brute Action
Compared—Limits of Human Power—Importance of Physical
Conservation and Restoration—Uncertainty as to Effects of Human Action
CHAPTER II.
TRANSFER, MODIFICATION, AND EXTIRPATION OF VEGETABLE AND OF ANIMAL
SPECIES.
Modern Geography takes Account of Organic Life—Geographical
Importance
of Plants—Origin of Domestic Vegetables—Transfer of Vegetable
Life—Objects of Modern Commerce—Foreign Plants, how
Introduced—Vegetable Power of Accommodation—Agricultural Products
of
the United States—Useful American Plants Grown in Europe—Extirpation
of Vegetables—Animal Life as a Geological and Geographical
Agency—Origin and Transfer of Domestic Quadrupeds—Extirpation of
Wild
Quadrupeds—Large Marine Animals Relatively Unimportant in
Geography—Introduction and Breeding of Fish—Destruction of
Fish—Geographical Importance of Birds—Introduction of
Birds—Destruction of Birds—Utility and Destruction of
Reptiles—Utility of Insects and Worms—Injury to the Forest by
Natural Advantages of the Territory of the Roman Empire—Physical
Decay of that Territory—Causes of the Decay—Reaction of Man on Nature
—Observation of Nature—Uncertainty of Our Historical Knowledge of
Ancient Climates—Uncertainty of Modern Meteorology—Stability of
Nature—Formation of Bogs—Natural Conditions Favorable to
Geographical Change—Destructiveness of Man—Human and Brute Action
Compared—Limits of Human Power—Importance of Physical
Conservation and Restoration—Uncertainty as to Effects of Human Action
CHAPTER II.
TRANSFER, MODIFICATION, AND EXTIRPATION OF VEGETABLE AND OF ANIMAL
SPECIES.
Modern Geography takes Account of Organic Life—Geographical
Importance
of Plants—Origin of Domestic Vegetables—Transfer of Vegetable
Life—Objects of Modern Commerce—Foreign Plants, how
Introduced—Vegetable Power of Accommodation—Agricultural Products
of
the United States—Useful American Plants Grown in Europe—Extirpation
of Vegetables—Animal Life as a Geological and Geographical
Agency—Origin and Transfer of Domestic Quadrupeds—Extirpation of
Wild
Quadrupeds—Large Marine Animals Relatively Unimportant in
Geography—Introduction and Breeding of Fish—Destruction of
Fish—Geographical Importance of Birds—Introduction of
Birds—Destruction of Birds—Utility and Destruction of
Reptiles—Utility of Insects and Worms—Injury to the Forest by
Page 27
Insects—Introduction of Insects—Destruction of Insects—Minute
Organisms
CHAPTER III.
THE WOODS.
The Habitable Earth Originally Wooded—General Meteorological
Influence
of the Forest—Electrical Action of Trees—Chemical Influence of
Woods—Trees as Protection against Malaria—Trees as Shelter to Ground
to the Leeward—Influence of the Forest as Inorganic on
Temperature—Thermometrical Action of Trees as Organic—Total Influence
of the Forest on Temperature—Influence of Forests as Inorganic on
Humidity of Air and Earth—Influence as Organic—Balance of Conflicting
Influences—Influence of Woods on Precipitation—Total Climatic Action
of the Forest—Influence of the Forest on Humidity of Soil—The Forest
in Winter—Summer Rain, Importance of—Influence of the Forest on the
Flow of Springs—Influence of the Forest on Inundations and
Torrents—Destructive Action of Torrents—Floods of the
Ardeche—Excavation by Torrents—Extinction of Torrents—Crushing
Force
of Torrents—Transporting Power of Water—The Po and its
Deposits—Mountain Slides—Forest as Protection against
Avalanches—Minor Uses of the Forest—Small Forest Plants and Vitality
of Seeds—Locusts do not Breed in Forests—General Functions of
Forest—General Consequences of Destruction of—Due Proportion of
Woodland—Proportion of Woodland in European Countries—Forests of
Great
Britain—Forests of France—Forests of Italy—Forests of
Germany—Forests of United States—American Forest Trees—European
Organisms
CHAPTER III.
THE WOODS.
The Habitable Earth Originally Wooded—General Meteorological
Influence
of the Forest—Electrical Action of Trees—Chemical Influence of
Woods—Trees as Protection against Malaria—Trees as Shelter to Ground
to the Leeward—Influence of the Forest as Inorganic on
Temperature—Thermometrical Action of Trees as Organic—Total Influence
of the Forest on Temperature—Influence of Forests as Inorganic on
Humidity of Air and Earth—Influence as Organic—Balance of Conflicting
Influences—Influence of Woods on Precipitation—Total Climatic Action
of the Forest—Influence of the Forest on Humidity of Soil—The Forest
in Winter—Summer Rain, Importance of—Influence of the Forest on the
Flow of Springs—Influence of the Forest on Inundations and
Torrents—Destructive Action of Torrents—Floods of the
Ardeche—Excavation by Torrents—Extinction of Torrents—Crushing
Force
of Torrents—Transporting Power of Water—The Po and its
Deposits—Mountain Slides—Forest as Protection against
Avalanches—Minor Uses of the Forest—Small Forest Plants and Vitality
of Seeds—Locusts do not Breed in Forests—General Functions of
Forest—General Consequences of Destruction of—Due Proportion of
Woodland—Proportion of Woodland in European Countries—Forests of
Great
Britain—Forests of France—Forests of Italy—Forests of
Germany—Forests of United States—American Forest Trees—European
Page 28
and
American Forest Trees Compared—The Forest does not furnish Food for
Man—First Removal of the Forest—Principal Causes of Destruction of
Forest—Destruction and Protection of Forests by Governments—Royal
Forests and Game-laws—Effects of the French Revolution—Increased
Demand for Lumber—Effects of Burning Forest—Floating of
Timber—Restoration of the Forest—Economy of the Forest—Forest
Legislation—Plantation of Forests In America—Financial Results of
Forest Plantations—Instability of American Life
CHAPTER IV.
THE WATERS.
Land Artificially Won from the Waters—Great Works of Material
Improvement—Draining of Lincolnshire Fens—Incursions of the Sea in the
Netherlands—Origin of Sea-dikes—Gain and Loss of Land in the
Netherlands—Marine Deposits on the Coast of Netherlands—Draining of
Lake of Haarlem—Draining of the Zuiderzee—Geographical Effects
of—Improvements in the Netherlands—Ancient Hydraulic Works—
Draining
of Lake Celano by Prince Torlonia—Incidental Consequences of Draining
Lakes—Draining of Marshes—Agricultural Draining—Meteorological
Effects of Draining—Geographical Effects of Draining—Geographical
Effects of Aqueducts and Canals—Antiquity of Irrigation—Irrigation in
Palestine, India, and Egypt—Irrigation in Europe—Meteorological
Effects of Irrigation—Water withdrawn from Rivers for
Irrigation—Injurious Effects of Rice-culture—Salts Deposited by Water
of Irrigation—Subterranean Waters—Artesian Wells—Artificial
Springs—Economizing Precipitation—Inundations in France—Basins of
Reception—Diversion of Rivers—Glacier Lakes—River Embankments—
American Forest Trees Compared—The Forest does not furnish Food for
Man—First Removal of the Forest—Principal Causes of Destruction of
Forest—Destruction and Protection of Forests by Governments—Royal
Forests and Game-laws—Effects of the French Revolution—Increased
Demand for Lumber—Effects of Burning Forest—Floating of
Timber—Restoration of the Forest—Economy of the Forest—Forest
Legislation—Plantation of Forests In America—Financial Results of
Forest Plantations—Instability of American Life
CHAPTER IV.
THE WATERS.
Land Artificially Won from the Waters—Great Works of Material
Improvement—Draining of Lincolnshire Fens—Incursions of the Sea in the
Netherlands—Origin of Sea-dikes—Gain and Loss of Land in the
Netherlands—Marine Deposits on the Coast of Netherlands—Draining of
Lake of Haarlem—Draining of the Zuiderzee—Geographical Effects
of—Improvements in the Netherlands—Ancient Hydraulic Works—
Draining
of Lake Celano by Prince Torlonia—Incidental Consequences of Draining
Lakes—Draining of Marshes—Agricultural Draining—Meteorological
Effects of Draining—Geographical Effects of Draining—Geographical
Effects of Aqueducts and Canals—Antiquity of Irrigation—Irrigation in
Palestine, India, and Egypt—Irrigation in Europe—Meteorological
Effects of Irrigation—Water withdrawn from Rivers for
Irrigation—Injurious Effects of Rice-culture—Salts Deposited by Water
of Irrigation—Subterranean Waters—Artesian Wells—Artificial
Springs—Economizing Precipitation—Inundations in France—Basins of
Reception—Diversion of Rivers—Glacier Lakes—River Embankments—
Page 29
Other
Remedies against Inundations—Dikes of the Nile—Deposits of Tuscan
Rivers—Improvements in Tuscan Maremma—Improvements in Val di
Chiana—Coast of the Netherlands
CHAPTER V.
THE SANDS.
Origin of Sand—Sand now Carried to the Sea—Beach Sands of Northern
Africa—Sands of Egypt—Sand Dunes and Sand Plains—Coast Dunes—
Sand
Banks—Character of Dune Sand—Interior Structure of Dunes—Geological
Importance of Dunes—Dunes on American Coasts—Dunes of Western
Europe—Age, Character, and Permanence of Dunes—Dunes as a Barrier
against the Sea—Encroachments of the Sea—Liimfjord—Coasts of
Schleswig-Holstein, Netherlands, and France—Movement of Dunes—
Control
of Dunes by Man—Inland Dunes—Inland Sand Plains
CHAPTER VI.
GREAT PROJECTS OF PHYSICAL CHANGE ACCOMPLISHED OR PROPOSED BY
MAN.
Cutting of Isthmuses—Canal of Suez—Maritime Canals in Greece—
Canals
to Dead Sea—Canals to Libyan Desert—Maritime Canals in Europe—Cape
Cod Canal—Changes in Caspian—Diversion of the Nile—Diversion of the
Rhine—Improvements in North American Hydrography—Soil below
Rock—Covering Rock with Earth—Desert Valleys—Effects of
Mining—Duponchel's Plans of Improvement—Action of Man on the
Weather—Resistance to Great Natural Forces—Incidental Effects of
Remedies against Inundations—Dikes of the Nile—Deposits of Tuscan
Rivers—Improvements in Tuscan Maremma—Improvements in Val di
Chiana—Coast of the Netherlands
CHAPTER V.
THE SANDS.
Origin of Sand—Sand now Carried to the Sea—Beach Sands of Northern
Africa—Sands of Egypt—Sand Dunes and Sand Plains—Coast Dunes—
Sand
Banks—Character of Dune Sand—Interior Structure of Dunes—Geological
Importance of Dunes—Dunes on American Coasts—Dunes of Western
Europe—Age, Character, and Permanence of Dunes—Dunes as a Barrier
against the Sea—Encroachments of the Sea—Liimfjord—Coasts of
Schleswig-Holstein, Netherlands, and France—Movement of Dunes—
Control
of Dunes by Man—Inland Dunes—Inland Sand Plains
CHAPTER VI.
GREAT PROJECTS OF PHYSICAL CHANGE ACCOMPLISHED OR PROPOSED BY
MAN.
Cutting of Isthmuses—Canal of Suez—Maritime Canals in Greece—
Canals
to Dead Sea—Canals to Libyan Desert—Maritime Canals in Europe—Cape
Cod Canal—Changes in Caspian—Diversion of the Nile—Diversion of the
Rhine—Improvements in North American Hydrography—Soil below
Rock—Covering Rock with Earth—Desert Valleys—Effects of
Mining—Duponchel's Plans of Improvement—Action of Man on the
Weather—Resistance to Great Natural Forces—Incidental Effects of
Page 30
Human
Action—Nothing Small In Nature
Action—Nothing Small In Nature
Page 31
THE EARTH AS MODIFIED BY HUMAN
ACTION.
CHAPTER 1.
INTRODUCTORY.
Natural Advantages of the Territory of the Roman Empire.—Physical
Decay
of that Territory.—Causes of the Decay.—Reaction of Man on Nature.—
Observation of Nature.—Uncertainty of Our Historical Knowledge of
Ancient Climates.—Uncertainty of Modern Meteorology.—Stability of
Nature.—Formation of Bogs—Natural Conditions Favorable to
Geographical
Change.—Destructiveness of Man—Human and Brute Action
Compared.—Limits of Human Power.—Importance of Physical
Conservation
and Restoration—Uncertainty as to Effects of Human Action.
Natural Advantages of the Territory of the Roman Empire.
The Roman Empire, at the period of its greatest expansion, comprised the
regions of the earth most distinguished by a happy combination of physical
conditions. The provinces bordering on the principal and the secondary
basins of the Mediterranean enjoyed in healthfulness and equability of
ACTION.
CHAPTER 1.
INTRODUCTORY.
Natural Advantages of the Territory of the Roman Empire.—Physical
Decay
of that Territory.—Causes of the Decay.—Reaction of Man on Nature.—
Observation of Nature.—Uncertainty of Our Historical Knowledge of
Ancient Climates.—Uncertainty of Modern Meteorology.—Stability of
Nature.—Formation of Bogs—Natural Conditions Favorable to
Geographical
Change.—Destructiveness of Man—Human and Brute Action
Compared.—Limits of Human Power.—Importance of Physical
Conservation
and Restoration—Uncertainty as to Effects of Human Action.
Natural Advantages of the Territory of the Roman Empire.
The Roman Empire, at the period of its greatest expansion, comprised the
regions of the earth most distinguished by a happy combination of physical
conditions. The provinces bordering on the principal and the secondary
basins of the Mediterranean enjoyed in healthfulness and equability of
Page 32
climate, in fertility of soil, in variety of vegetable and mineral products, and
in natural facilities for the transportation and distribution of exchangeable
commodities, advantages which have not been possessed in any equal
degree by any territory of like extent in the Old World or the New. The
abundance of the land and of the waters adequately supplied every material
want, ministered liberally to every sensuous enjoyment. Gold and silver,
indeed, were not found in the profusion which has proved so baneful to the
industry of lands richer in veins of the precious metals; but mines and river
beds yielded them in the spare measure most favorable to stability of value
in the medium of exchange, and, consequently, to the regularity of
commercial transactions. The ornaments of the barbaric pride of the East,
the pearl, the ruby, the sapphire, and the diamond—though not unknown to
the luxury of a people whose conquests and whose wealth commanded
whatever the habitable world could contribute to augment the material
splendor of their social life—were scarcely native to the territory of the
empire; but the comparative rarity of these gems in Europe, at somewhat
earlier periods, was, perhaps, the very circumstance that led the cunning
artists of classic antiquity to enrich softer stones with engravings, which
invest the common onyx and cornelian with a worth surpassing, in
cultivated eyes, the lustre of the most brilliant oriental jewels.
Of these manifold blessings the temperature of the air, the distribution of
the rains, the relative disposition of land and water, the plenty of the sea, the
composition of the soil, and the raw material of the primitive arts, were
wholly gratuitous gifts. Yet the spontaneous nature of Europe, of Western
Asia, of Libya, neither fed nor clothed the civilized inhabitants of those
provinces. The luxuriant harvests of cereals that waved on every field from
the shores of the Rhine to the banks of the Nile, the vines that festooned the
hillsides of Syria, of Italy and of Greece, the olives of Spain, the fruits of
the gardens of the Hesperides, the domestic quadrupeds and fowls known in
ancient rural husbandry—all these were original products of foreign climes,
in natural facilities for the transportation and distribution of exchangeable
commodities, advantages which have not been possessed in any equal
degree by any territory of like extent in the Old World or the New. The
abundance of the land and of the waters adequately supplied every material
want, ministered liberally to every sensuous enjoyment. Gold and silver,
indeed, were not found in the profusion which has proved so baneful to the
industry of lands richer in veins of the precious metals; but mines and river
beds yielded them in the spare measure most favorable to stability of value
in the medium of exchange, and, consequently, to the regularity of
commercial transactions. The ornaments of the barbaric pride of the East,
the pearl, the ruby, the sapphire, and the diamond—though not unknown to
the luxury of a people whose conquests and whose wealth commanded
whatever the habitable world could contribute to augment the material
splendor of their social life—were scarcely native to the territory of the
empire; but the comparative rarity of these gems in Europe, at somewhat
earlier periods, was, perhaps, the very circumstance that led the cunning
artists of classic antiquity to enrich softer stones with engravings, which
invest the common onyx and cornelian with a worth surpassing, in
cultivated eyes, the lustre of the most brilliant oriental jewels.
Of these manifold blessings the temperature of the air, the distribution of
the rains, the relative disposition of land and water, the plenty of the sea, the
composition of the soil, and the raw material of the primitive arts, were
wholly gratuitous gifts. Yet the spontaneous nature of Europe, of Western
Asia, of Libya, neither fed nor clothed the civilized inhabitants of those
provinces. The luxuriant harvests of cereals that waved on every field from
the shores of the Rhine to the banks of the Nile, the vines that festooned the
hillsides of Syria, of Italy and of Greece, the olives of Spain, the fruits of
the gardens of the Hesperides, the domestic quadrupeds and fowls known in
ancient rural husbandry—all these were original products of foreign climes,
Page 33
naturalized in new homes, and gradually ennobled by the art of man, while
centuries of persevering labor were expelling the wild vegetation, and
fitting the earth for the production of more generous growths. Every loaf
was eaten in the sweat of the brow. All must be earned by toil. But toil was
nowhere else rewarded by so generous wages; for nowhere would a given
amount of intelligent labor produce so abundant, and, at the same time, so
varied returns of the good things of material existence.
Physical Decay of the Territory of the Roman Empire.
If we compare the present physical condition of the countries of which I
am speaking, with the descriptions that ancient historians and geographers
have given of their fertility and general capability of ministering to human
uses, we shall find that more than one-half their whole extent—not
excluding the provinces most celebrated for the profusion and variety of
their spontaneous and their cultivated products, and for the wealth and
social advancement of their inhabitants—is either deserted by civilized man
and surrendored to hopeless desolation, or at least greatly reduced in both
productiveness and population. Vast forests have disappeared from
mountain spurs and ridges; the vegetable earth accumulated beneath the
trees by the decay of leaves and fallen trunks, the soil of the alpine pastures
which skirted and indented the woods, and the mould of the upland fields,
are washed away; meadows, once fertilized by irrigation, are waste and
unproductive because the cisterns and reservoirs that supplied the ancient
canals are broken, or the springs that fed them dried up; rivers famous in
history and song have shrunk to humble brooklets; the willows that
ornamented and protected the banks of the lesser watercourses are gone,
and the rivulets have ceased to exist as perennial currents, because the little
water that finds its way into their old channels is evaporated by the droughts
of summer, or absorbed by the parched earth before it reaches the lowlands;
centuries of persevering labor were expelling the wild vegetation, and
fitting the earth for the production of more generous growths. Every loaf
was eaten in the sweat of the brow. All must be earned by toil. But toil was
nowhere else rewarded by so generous wages; for nowhere would a given
amount of intelligent labor produce so abundant, and, at the same time, so
varied returns of the good things of material existence.
Physical Decay of the Territory of the Roman Empire.
If we compare the present physical condition of the countries of which I
am speaking, with the descriptions that ancient historians and geographers
have given of their fertility and general capability of ministering to human
uses, we shall find that more than one-half their whole extent—not
excluding the provinces most celebrated for the profusion and variety of
their spontaneous and their cultivated products, and for the wealth and
social advancement of their inhabitants—is either deserted by civilized man
and surrendored to hopeless desolation, or at least greatly reduced in both
productiveness and population. Vast forests have disappeared from
mountain spurs and ridges; the vegetable earth accumulated beneath the
trees by the decay of leaves and fallen trunks, the soil of the alpine pastures
which skirted and indented the woods, and the mould of the upland fields,
are washed away; meadows, once fertilized by irrigation, are waste and
unproductive because the cisterns and reservoirs that supplied the ancient
canals are broken, or the springs that fed them dried up; rivers famous in
history and song have shrunk to humble brooklets; the willows that
ornamented and protected the banks of the lesser watercourses are gone,
and the rivulets have ceased to exist as perennial currents, because the little
water that finds its way into their old channels is evaporated by the droughts
of summer, or absorbed by the parched earth before it reaches the lowlands;
Page 34
the beds of the brooks have widened into broad expanses of pebbles and
gravel, over which, though in the hot season passed dryshod, in winter
sealike torrents thunder; the entrances of navigable streams are obstructed
by sandbars; and harbors, once marts of an extensive commerce, are
shoaled by the deposits of the rivers at whose mouths they lie; the elevation
of the beds of estuaries, and the consequently diminished velocity and
increased lateral spread of the streams which flow into them, have
converted thousands of leagues of shallow sea and fertile lowland into
unproductive and miasmatic morasses.
Besides the direct testimony of history to the ancient fertility of the now
exhausted regions to which I refer—Northern Africa, the greater Arabian
peninsula, Syria, Mesopotamia, Armenia and many other provinces of Asia
Minor, Greece, Sicily, and parts of even Italy and Spain—the multitude and
extent of yet remaining architectural ruins, and of decayed works of internal
improvement, show that at former epochs a dense population inhabited
those now lonely districts. Such a population could have been sustained
only by a productiveness of soil of which we at present discover but slender
traces; and the abundance derived from that fertility serves to explain how
large armies, like those of the ancient Persians, and of the Crusaders and the
Tartars in later ages, could, without an organized commissariat, secure
adequate supplies in long marches through territories which, in our times,
would scarcely afford forage for a single regiment.
It appears then, that the fairest and fruitfulest provinces of the Roman
Empire, precisely that portion of terrestrial surface, in short, which, about
the commencement of the Christian era, was endowed with the greatest
superiority of soil, climate, and position, which had been carried to the
highest pitch of physical improvement, and which thus combined the
natural and artificial conditions best fitting it for the habitation and
enjoyment of a dense and highly refined and cultivated population, are now
gravel, over which, though in the hot season passed dryshod, in winter
sealike torrents thunder; the entrances of navigable streams are obstructed
by sandbars; and harbors, once marts of an extensive commerce, are
shoaled by the deposits of the rivers at whose mouths they lie; the elevation
of the beds of estuaries, and the consequently diminished velocity and
increased lateral spread of the streams which flow into them, have
converted thousands of leagues of shallow sea and fertile lowland into
unproductive and miasmatic morasses.
Besides the direct testimony of history to the ancient fertility of the now
exhausted regions to which I refer—Northern Africa, the greater Arabian
peninsula, Syria, Mesopotamia, Armenia and many other provinces of Asia
Minor, Greece, Sicily, and parts of even Italy and Spain—the multitude and
extent of yet remaining architectural ruins, and of decayed works of internal
improvement, show that at former epochs a dense population inhabited
those now lonely districts. Such a population could have been sustained
only by a productiveness of soil of which we at present discover but slender
traces; and the abundance derived from that fertility serves to explain how
large armies, like those of the ancient Persians, and of the Crusaders and the
Tartars in later ages, could, without an organized commissariat, secure
adequate supplies in long marches through territories which, in our times,
would scarcely afford forage for a single regiment.
It appears then, that the fairest and fruitfulest provinces of the Roman
Empire, precisely that portion of terrestrial surface, in short, which, about
the commencement of the Christian era, was endowed with the greatest
superiority of soil, climate, and position, which had been carried to the
highest pitch of physical improvement, and which thus combined the
natural and artificial conditions best fitting it for the habitation and
enjoyment of a dense and highly refined and cultivated population, are now
Page 35
completely exhausted of their fertility, or so diminished in productiveness,
as, with the exception of a few favored oases that have escaped the general
ruin, to be no longer capable of affording sustenance to civilized man. If to
this realm of desolation we add the now wasted and solitary soils of Persia
and the remoter East that once fed their millions with milk and honey, we
shall see that a territory larger than all Europe, the abundance of which
sustained in bygone centuries a population scarcely inferior to that of the
whole Christian world at the present day, has been entirely withdrawn from
human use, or, at best, is thinly inhabited by tribes too few in numbers, too
poor in superfluous products, and too little advanced in culture and the
social arts, to contribute anything to the general moral or material interests
of the great commonwealth of man.
Causes of this Decay.
The decay of these once flourishing countries is partly due, no doubt, to
that class of geological causes whose action we can neither resist nor guide,
and partly also to the direct violence of hostile human force; but it is, in a
far greater proportion, either the result of man's ignorant disregard of the
laws of nature, or an incidental consequence of war and of civil and
ecclesiastical tyranny and misrule. Next to ignorance of these laws, the
primitive source, the causa causarum, of the acts and neglects which have
blasted with sterility and physical decrepitude the noblest half of the empire
of the Caesars, is, first, the brutal and exhausting despotism which Rome
herself exercised over her conquered kingdoms, and even over her Italian
territory; then, the host of temporal and spiritual tyrannies which she left as
her dying curse to all her wide dominion, and which, in some form of
violence or of fraud, still brood over almost every soil subdued by the
Roman legions. [Footnote: In the Middle Ages, feudalism, and a nominal
Christianity, whose corruptions had converted the most beneficent of
as, with the exception of a few favored oases that have escaped the general
ruin, to be no longer capable of affording sustenance to civilized man. If to
this realm of desolation we add the now wasted and solitary soils of Persia
and the remoter East that once fed their millions with milk and honey, we
shall see that a territory larger than all Europe, the abundance of which
sustained in bygone centuries a population scarcely inferior to that of the
whole Christian world at the present day, has been entirely withdrawn from
human use, or, at best, is thinly inhabited by tribes too few in numbers, too
poor in superfluous products, and too little advanced in culture and the
social arts, to contribute anything to the general moral or material interests
of the great commonwealth of man.
Causes of this Decay.
The decay of these once flourishing countries is partly due, no doubt, to
that class of geological causes whose action we can neither resist nor guide,
and partly also to the direct violence of hostile human force; but it is, in a
far greater proportion, either the result of man's ignorant disregard of the
laws of nature, or an incidental consequence of war and of civil and
ecclesiastical tyranny and misrule. Next to ignorance of these laws, the
primitive source, the causa causarum, of the acts and neglects which have
blasted with sterility and physical decrepitude the noblest half of the empire
of the Caesars, is, first, the brutal and exhausting despotism which Rome
herself exercised over her conquered kingdoms, and even over her Italian
territory; then, the host of temporal and spiritual tyrannies which she left as
her dying curse to all her wide dominion, and which, in some form of
violence or of fraud, still brood over almost every soil subdued by the
Roman legions. [Footnote: In the Middle Ages, feudalism, and a nominal
Christianity, whose corruptions had converted the most beneficent of
Page 36
religions into the most baneful of superstitions, perpetuated every abuse of
Roman tyranny, and added new oppressions and new methods of extortion
to those invented by older despotisms. The burdens in question fell most
heavily on the provinces that had been longest colonized by the Latin race,
and those are the portions of Europe which have suffered the greatest
physical degradation. "Feudalism," says Blanqui, "was a concentration of
scourges. The peasant, stripped of the inheritance of his fathers, became the
property of inflexible, ignorant, indolent masters; he was obliged to travel
fifty leagues with their carts whenever they required it; he labored for them
three days in the week, and surrendered to them half the product of his
earnings during the other three; without their consent he could not change
his residence, or marry. And why, indeed, should he wish to marry, when he
could scarcely save enough to maintain himself The Abbot Alcuin had
twenty thousand slaves, called SERFS, who were forever attached to the
soil. This is the great cauue of the rapid depopulation observed in the
Middle Ages, and of the prodigious multitude of monasteries which sprang
up on every side. It was doubtless a relief to such miserable men to find in
the cloisters a retreat from oppression; but the human race never suffered a
more cruel outrage, industry never received a wound better calculated to
plunge the world again into the darkness of the rudest antiquity. It suffices
to say that the prediction of the approaching end of the world, industriously
spread by the rapacious monks at this time, was received without terror."—
Resume de l'Histoire du Commerce, p. 156.] Man cannot struggle at once
against human oppression and the destructive forces of inorganic nature.
"When both are combined against him, he succumbs after a shorter or
longer struggle, and the fields he has won from the primeval wood relapse
into their original state of wild and luxuriant, but unprofitable forest growth,
or fall into that of a dry and barren wilderness. The abbey of Saint-
Germain-des-Pres, which, in the time of Charlemagne, had possessed a
million of acres, was, down to the Revolution, still so wealthy, that the
Roman tyranny, and added new oppressions and new methods of extortion
to those invented by older despotisms. The burdens in question fell most
heavily on the provinces that had been longest colonized by the Latin race,
and those are the portions of Europe which have suffered the greatest
physical degradation. "Feudalism," says Blanqui, "was a concentration of
scourges. The peasant, stripped of the inheritance of his fathers, became the
property of inflexible, ignorant, indolent masters; he was obliged to travel
fifty leagues with their carts whenever they required it; he labored for them
three days in the week, and surrendered to them half the product of his
earnings during the other three; without their consent he could not change
his residence, or marry. And why, indeed, should he wish to marry, when he
could scarcely save enough to maintain himself The Abbot Alcuin had
twenty thousand slaves, called SERFS, who were forever attached to the
soil. This is the great cauue of the rapid depopulation observed in the
Middle Ages, and of the prodigious multitude of monasteries which sprang
up on every side. It was doubtless a relief to such miserable men to find in
the cloisters a retreat from oppression; but the human race never suffered a
more cruel outrage, industry never received a wound better calculated to
plunge the world again into the darkness of the rudest antiquity. It suffices
to say that the prediction of the approaching end of the world, industriously
spread by the rapacious monks at this time, was received without terror."—
Resume de l'Histoire du Commerce, p. 156.] Man cannot struggle at once
against human oppression and the destructive forces of inorganic nature.
"When both are combined against him, he succumbs after a shorter or
longer struggle, and the fields he has won from the primeval wood relapse
into their original state of wild and luxuriant, but unprofitable forest growth,
or fall into that of a dry and barren wilderness. The abbey of Saint-
Germain-des-Pres, which, in the time of Charlemagne, had possessed a
million of acres, was, down to the Revolution, still so wealthy, that the
Page 37
personal income of the abbot was 300,000 livres. Theabbey of Saint-Denis
was nearly as rich as that of Saint-Germain-des-Pres.—Lavergne, Economie
Rurale de la France, p. 104.
Paul Louis Courier quotes from La Bruyere the following striking picture
of the condition of the French peasantry in his time: "One sees certain dark,
livid, naked, sunburnt, wild animals, male and female, scattered over the
country and attached to the soil, which they root and turn over with
indomitable perseverance. They have, as it were, an articulate voice, and
when they rise to their feet, they show a human face. They are, in fact, men;
they creep at night into dens, where they live on black bread, water, and
roots. They spare other men the labor of ploughing, Bowing, and
harvesting, and therefore deserve some small share of the bread they have
grown." "These are his own words," adds Courier, "and he is speaking of
the fortunate peasants, of those who had work and bread, and they were
then the few."—Petition a la Chambre des Deputes pour les Villageois l'en
empeche ce danser.
Arthur Young, who travelled in France from 1787 to 1789, gives, in the
twenty-first chapter of his Travels, a frightful account of the burdens of the
rural population even at that late period. Besides the regular governmental
taxes, and a multitude of heavy fines imposed for trifling offense, he
enumerates about thirty seignorial rights, the very origin and nature of some
of which are now unknown, while those of some others are as repulsive to
humanity and morality, as the worst abuses ever practised by heathen
despotism. But Young underrates the number of these oppressive
impositions. Moreau de Jonnes, a higher authority, asserts that in a brief
examination he had discovered upwards of three hundred distinct lights of
the feudatory over the person or the property of his vassal. See Etat
Economique et Social de la France, Paris, 1890, p. 389. Most of these,
indeed, had been commuted for money payments, and were levied on the
was nearly as rich as that of Saint-Germain-des-Pres.—Lavergne, Economie
Rurale de la France, p. 104.
Paul Louis Courier quotes from La Bruyere the following striking picture
of the condition of the French peasantry in his time: "One sees certain dark,
livid, naked, sunburnt, wild animals, male and female, scattered over the
country and attached to the soil, which they root and turn over with
indomitable perseverance. They have, as it were, an articulate voice, and
when they rise to their feet, they show a human face. They are, in fact, men;
they creep at night into dens, where they live on black bread, water, and
roots. They spare other men the labor of ploughing, Bowing, and
harvesting, and therefore deserve some small share of the bread they have
grown." "These are his own words," adds Courier, "and he is speaking of
the fortunate peasants, of those who had work and bread, and they were
then the few."—Petition a la Chambre des Deputes pour les Villageois l'en
empeche ce danser.
Arthur Young, who travelled in France from 1787 to 1789, gives, in the
twenty-first chapter of his Travels, a frightful account of the burdens of the
rural population even at that late period. Besides the regular governmental
taxes, and a multitude of heavy fines imposed for trifling offense, he
enumerates about thirty seignorial rights, the very origin and nature of some
of which are now unknown, while those of some others are as repulsive to
humanity and morality, as the worst abuses ever practised by heathen
despotism. But Young underrates the number of these oppressive
impositions. Moreau de Jonnes, a higher authority, asserts that in a brief
examination he had discovered upwards of three hundred distinct lights of
the feudatory over the person or the property of his vassal. See Etat
Economique et Social de la France, Paris, 1890, p. 389. Most of these,
indeed, had been commuted for money payments, and were levied on the
Page 38
peasantry as pecuniary imposts for the benefit of prelates and lay lords,
who, by virtue of their nobility, were exempt from taxation. The collection
of the taxes was enforced with unrelenting severity. On one occasion, in the
reign of Louis XIV., the troops sent out against the recreant peasants made
more than 3,000 prisoners, of whom 400 were condemned to the galleys for
life, and a number so large that the government did not dare to disclose it,
were hung on trees or broken on the wheel.—Moreau de Jonnes, Etat
Economique et Social de la France, p. 420. Who can wonder at the hostility
of the French plebeian classes towards the aristocracy in the days of the
Revolution?
Rome imposed on the products of agricultural labor in the rural districts
taxes which the sale of the entire harvest would scarcely discharge; she
drained them of their population by military conscription; she impoverished
the peasantry by forced and unpaid labor on public works; she hampered
industry and both foreign and internal commerce by absurd restrictions and
unwise regulations. [Footnote: Commerce, in common with all gainful
occupations except agriculture, was despised by the Romans, and the
exercise of it was forbidden to the higher ranks. Cicero, however, admits
that though retail trade, which could only prosper by lying and knavery, was
contemptible, yet wholesale commerce was not altogether to be condemned,
and might even be laudable, provided the merchant retired early from trade
and invested his gaits in farm lands.—De Officiis, lib. i.,42.] Hence, large
tracts of land were left uncultivated, or altogether deserted, and exposed to
all the destructive forces which act with such energy on the surface of the
earth when it is deprived of those protections by which nature originally
guarded it, and for which, in well-ordered husbandry, human ingenuity has
contrived more or less efficient substitutes. [Footnote: The temporary
depopulation of an exhausted soil may be, in some cases, a physical,
though, like fallows in agriculture, a dear-bought advantage. Under
favorable circumstances, the withdrawal of man and his flocks allows the
who, by virtue of their nobility, were exempt from taxation. The collection
of the taxes was enforced with unrelenting severity. On one occasion, in the
reign of Louis XIV., the troops sent out against the recreant peasants made
more than 3,000 prisoners, of whom 400 were condemned to the galleys for
life, and a number so large that the government did not dare to disclose it,
were hung on trees or broken on the wheel.—Moreau de Jonnes, Etat
Economique et Social de la France, p. 420. Who can wonder at the hostility
of the French plebeian classes towards the aristocracy in the days of the
Revolution?
Rome imposed on the products of agricultural labor in the rural districts
taxes which the sale of the entire harvest would scarcely discharge; she
drained them of their population by military conscription; she impoverished
the peasantry by forced and unpaid labor on public works; she hampered
industry and both foreign and internal commerce by absurd restrictions and
unwise regulations. [Footnote: Commerce, in common with all gainful
occupations except agriculture, was despised by the Romans, and the
exercise of it was forbidden to the higher ranks. Cicero, however, admits
that though retail trade, which could only prosper by lying and knavery, was
contemptible, yet wholesale commerce was not altogether to be condemned,
and might even be laudable, provided the merchant retired early from trade
and invested his gaits in farm lands.—De Officiis, lib. i.,42.] Hence, large
tracts of land were left uncultivated, or altogether deserted, and exposed to
all the destructive forces which act with such energy on the surface of the
earth when it is deprived of those protections by which nature originally
guarded it, and for which, in well-ordered husbandry, human ingenuity has
contrived more or less efficient substitutes. [Footnote: The temporary
depopulation of an exhausted soil may be, in some cases, a physical,
though, like fallows in agriculture, a dear-bought advantage. Under
favorable circumstances, the withdrawal of man and his flocks allows the
Page 39
earth to clothe itself again with forests, and in a few generations to recover
its ancient productiveness. In the Middle Ages, worn-out fields were
depopulated, in many parts of the Continent, by civil and ecclesiastical
tyrannies, which insisted on the surrender of the half of a loaf already too
small to sustain its producer. Thus abandoned, these lands often relapsed
into the forest state, and, some centuries later, were again brought under
cultivation with renovated fertility.] Similar abuses have tended to
perpetuate and extend these evils in later ages, and it is but recently that,
even in the most populous parts of Europe, public attention has been half
awakened to the necessity of restoring the disturbed harmonies of nature,
whose well-balanced influences are so propitious to all her organic
offspring, and of repaying to our great mother the debt which the
prodigality and the thriftlessness of former generations have imposed upon
their successors—thus fulfilling the command of religion and of practical
wisdom, to use this world as not abusing it.
Reaction of Man on Nature.
The revolutions of the seasons, with their alternations of temperature and
of length of day and night, the climates of different zones, and the general
conditions and movements of the atmosphere and the seas, depend upon
causes for the most part cosmical, and, of course, wholly beyond our
control. The elevation, configuration, and composition of the great masses
of terrestrial surface, and the relative extent and distribution of land and
water, are determined by geological influences equally remote from our
jurisdiction. It would hence seem that the physical adaptation of different
portions of the earth to the use and enjoyment of man is a matter so strictly
belonging to mightier than human powers, that we can only accept
geographical nature as we find her, and be content with such soils and such
skies as she spontaneously offers.
its ancient productiveness. In the Middle Ages, worn-out fields were
depopulated, in many parts of the Continent, by civil and ecclesiastical
tyrannies, which insisted on the surrender of the half of a loaf already too
small to sustain its producer. Thus abandoned, these lands often relapsed
into the forest state, and, some centuries later, were again brought under
cultivation with renovated fertility.] Similar abuses have tended to
perpetuate and extend these evils in later ages, and it is but recently that,
even in the most populous parts of Europe, public attention has been half
awakened to the necessity of restoring the disturbed harmonies of nature,
whose well-balanced influences are so propitious to all her organic
offspring, and of repaying to our great mother the debt which the
prodigality and the thriftlessness of former generations have imposed upon
their successors—thus fulfilling the command of religion and of practical
wisdom, to use this world as not abusing it.
Reaction of Man on Nature.
The revolutions of the seasons, with their alternations of temperature and
of length of day and night, the climates of different zones, and the general
conditions and movements of the atmosphere and the seas, depend upon
causes for the most part cosmical, and, of course, wholly beyond our
control. The elevation, configuration, and composition of the great masses
of terrestrial surface, and the relative extent and distribution of land and
water, are determined by geological influences equally remote from our
jurisdiction. It would hence seem that the physical adaptation of different
portions of the earth to the use and enjoyment of man is a matter so strictly
belonging to mightier than human powers, that we can only accept
geographical nature as we find her, and be content with such soils and such
skies as she spontaneously offers.
Page 40
But it is certain that man has reacted upon organized and inorganic
nature, and thereby modified, if not determined, the material structure of his
earthly home. The measure of that reaction manifestly constitutes a very
important element in the appreciation of the relations between mind and
matter, as well as in the discussion of many purely physical problems. But
though the subject has been incidentally touched upon by many
geographers, and treated with much fulness of detail in regard to certain
limited fields of human effort and to certain specific effects of human
action, it has not, as a whole, so tar as I know, been made matter of special
observation, or of historical research, by any scientific inquirer. Indeed,
until the influence of geographical conditions upon human life was
recognized as a distinct branch of philosophical investigation, there was no
motive for the pursuit of such speculations; and it was desirable to inquire
how far we have, or can, become the architects of our own abiding place,
only when it was known how the mode of our physical, moral, and
intellectual being is affected by the character of the home which Providence
has appointed, and we have fashioned, for our material habitation.
[Footnote:Gods Almagt wenkte van den troon, En schiep elk volk een land
ter woon: Hier vestte Zij een grondgebied, Dat Zij ona zelven scheppon
llet.] It is still too early to attempt scientific method in discussing this
problem, nor is our present store of the necessary facts by any means
complete enough to warrant me in promising any approach to fulness of
statement respecting them. Systematic observation in relation to this subject
has hardly yet begun, and the scattered data which have chanced to be
recorded have never been collected. It has now no place in the general
scheme of physical science, and is matter of suggestion and speculation
only, not of established and positive conclusion. At present, then, all that I
can hope is to excite an interest in a topic of much economical importance,
by pointing out the directions and illustrating the modes in which human
action has been, or may be, most injurious or most beneficial in its
nature, and thereby modified, if not determined, the material structure of his
earthly home. The measure of that reaction manifestly constitutes a very
important element in the appreciation of the relations between mind and
matter, as well as in the discussion of many purely physical problems. But
though the subject has been incidentally touched upon by many
geographers, and treated with much fulness of detail in regard to certain
limited fields of human effort and to certain specific effects of human
action, it has not, as a whole, so tar as I know, been made matter of special
observation, or of historical research, by any scientific inquirer. Indeed,
until the influence of geographical conditions upon human life was
recognized as a distinct branch of philosophical investigation, there was no
motive for the pursuit of such speculations; and it was desirable to inquire
how far we have, or can, become the architects of our own abiding place,
only when it was known how the mode of our physical, moral, and
intellectual being is affected by the character of the home which Providence
has appointed, and we have fashioned, for our material habitation.
[Footnote:Gods Almagt wenkte van den troon, En schiep elk volk een land
ter woon: Hier vestte Zij een grondgebied, Dat Zij ona zelven scheppon
llet.] It is still too early to attempt scientific method in discussing this
problem, nor is our present store of the necessary facts by any means
complete enough to warrant me in promising any approach to fulness of
statement respecting them. Systematic observation in relation to this subject
has hardly yet begun, and the scattered data which have chanced to be
recorded have never been collected. It has now no place in the general
scheme of physical science, and is matter of suggestion and speculation
only, not of established and positive conclusion. At present, then, all that I
can hope is to excite an interest in a topic of much economical importance,
by pointing out the directions and illustrating the modes in which human
action has been, or may be, most injurious or most beneficial in its
Page 41
influence upon the physical conditions of the earth we inhabit We cannot
always distinguish between the results of man's action and the effects of
purely geological or cosmical causes. The destruction of the forests, the
drainage of lakes and marshes, and the operations of rural husbandry and
industrial art have unquestionably tended to produce great changes in the
hygrometric, thermometric, electric, and chemical condition of the
atmosphere, though we are not yet able to measure the force of the different
elements of disturbance, or to say how far they have been neutralised by
each other, or by still obscurer influences; and it is equally certain that the
myriad forms of animal and vegetable life, which covered the earth when
man first entered upon the theatre of a nature whose harmonies he was
destined to derange, have been, through his interference, greatly changed in
numerical proportion, sometimes much modified in form and product, and
sometimes entirely extirpated. [Footnote: Man has not only subverted the
natural numerical relations of wild as well as domestic quadrupeds, fish,
birds, reptile, insect, and common plants, and even of still humbler tribes of
animal and vegetable life, but he has effected in the forms, habits, nutriment
and products of the organisms which minister to his wants and his
pleasures, changes which, more than any other manifestaion of human
energy, resemble the exercise of a creative power. Even wild animals have
been compelled by him, through the destruction of plants and insects which
furnished their proper aliment, to resort to food belonging to a different
kingdom of nature. Thus a New Zealand bird, originally granivorous and
insectivorous, has become carnivorous, from the want of its natural
supplies, and now tears the fleeces from the backs of the sheep, in order to
feed on their living flesh. All these changes have exercised more or less
direct or indirect action on the inorganic surface of the globe; and the
history of the geographical revolutions thus produced would furnish ample
material for a volume.
always distinguish between the results of man's action and the effects of
purely geological or cosmical causes. The destruction of the forests, the
drainage of lakes and marshes, and the operations of rural husbandry and
industrial art have unquestionably tended to produce great changes in the
hygrometric, thermometric, electric, and chemical condition of the
atmosphere, though we are not yet able to measure the force of the different
elements of disturbance, or to say how far they have been neutralised by
each other, or by still obscurer influences; and it is equally certain that the
myriad forms of animal and vegetable life, which covered the earth when
man first entered upon the theatre of a nature whose harmonies he was
destined to derange, have been, through his interference, greatly changed in
numerical proportion, sometimes much modified in form and product, and
sometimes entirely extirpated. [Footnote: Man has not only subverted the
natural numerical relations of wild as well as domestic quadrupeds, fish,
birds, reptile, insect, and common plants, and even of still humbler tribes of
animal and vegetable life, but he has effected in the forms, habits, nutriment
and products of the organisms which minister to his wants and his
pleasures, changes which, more than any other manifestaion of human
energy, resemble the exercise of a creative power. Even wild animals have
been compelled by him, through the destruction of plants and insects which
furnished their proper aliment, to resort to food belonging to a different
kingdom of nature. Thus a New Zealand bird, originally granivorous and
insectivorous, has become carnivorous, from the want of its natural
supplies, and now tears the fleeces from the backs of the sheep, in order to
feed on their living flesh. All these changes have exercised more or less
direct or indirect action on the inorganic surface of the globe; and the
history of the geographical revolutions thus produced would furnish ample
material for a volume.
Page 42
The modification of organic species by domestication is a branch of
philosophic inquiry which we may almost say has been created by Darwin;
but the geographical results of these modifications do not appear to have yet
been made a subject of scientific investigation.
I do not know that the following passage from Pliny has ever been cited
in connection with the Darwinian theories but it is worth a reference:
"But behold a very strange and new fashion of them [cucumbers] in
Campane, for there you shall have abundance of them come up in forme of
a Quince. And as I heare say, one of the channced so to grow first at a very
venture; but afterwards from the seed of it came a whole race and progenie
of the like, which therefore they call Melonopopones, as a man would say,
the Quince-pompions or cucumbers"—Pliny, Nat. Hist., Holland's
translation, book xix, c.5
The word cucumis used in the original of this passage embraces many of
the cucurbitaceae, but the context shows that here means the cucumber.
The physical revolutions thus wrought by man have not indeed all been
destructive to human interests, and the heaviest blows he has inflicted upon
nature have not been wholly without their compensations. Soils to which no
nutritious vegetable was indigenous, countries which once brought forth but
the fewest products suited for the sustenance and comfort of man—while
the severity of their climates created and stimulated the greatest number and
the most imperious urgency of physical wants—surfaces the most rugged
and intractable, and least blessed with natural facilities of communication,
have been brought in modern times to yield and distribute all that supplies
the material necessities, all that contributes to the sensuous enjoyments and
conveniences of civilized life. The Scythia, the Thule, the Britain, the
Germany, and the Gaul which the Roman writers describe in such
forbidding terms, have been brought almost to rival the native luxuriance
philosophic inquiry which we may almost say has been created by Darwin;
but the geographical results of these modifications do not appear to have yet
been made a subject of scientific investigation.
I do not know that the following passage from Pliny has ever been cited
in connection with the Darwinian theories but it is worth a reference:
"But behold a very strange and new fashion of them [cucumbers] in
Campane, for there you shall have abundance of them come up in forme of
a Quince. And as I heare say, one of the channced so to grow first at a very
venture; but afterwards from the seed of it came a whole race and progenie
of the like, which therefore they call Melonopopones, as a man would say,
the Quince-pompions or cucumbers"—Pliny, Nat. Hist., Holland's
translation, book xix, c.5
The word cucumis used in the original of this passage embraces many of
the cucurbitaceae, but the context shows that here means the cucumber.
The physical revolutions thus wrought by man have not indeed all been
destructive to human interests, and the heaviest blows he has inflicted upon
nature have not been wholly without their compensations. Soils to which no
nutritious vegetable was indigenous, countries which once brought forth but
the fewest products suited for the sustenance and comfort of man—while
the severity of their climates created and stimulated the greatest number and
the most imperious urgency of physical wants—surfaces the most rugged
and intractable, and least blessed with natural facilities of communication,
have been brought in modern times to yield and distribute all that supplies
the material necessities, all that contributes to the sensuous enjoyments and
conveniences of civilized life. The Scythia, the Thule, the Britain, the
Germany, and the Gaul which the Roman writers describe in such
forbidding terms, have been brought almost to rival the native luxuriance
Page 43
and easily won plenty of Southern Italy; and, while the fountains of oil and
wine that refreshed old Greece and Syria and Northern Africa have almost
ceased to flow, and the soils of those fair lands are turned to thirsty and
inhospitable deserts, the hyperborean regions of Europe have learnod to
conquer, or rather compensate, the rigors of climate, and have attained to a
material wealth and variety of product that, with all their natural
advantages, the granaries of the ancient world can hardly be said to have
enjoyed.
Observation of Nature.
In these pages it is my aim to stimulate, not to satisfy, curiosity, and it is
no part of my object to save my readers the labor of observation or of
thought. For labor is life, and Death lives where power lives unused.
[Footnote: Verses addressed by G. C. to Sir Walter Raleigh.—Haklutt, i., p.
608.]
Self is the schoolmaster whose lessons are best worth his wages; and
since the subject I am considering has not yet become a branch of formal
instruction, those whom it may interest can, fortunately, have no pedagogue
but themselves. To the natural philosopher, the descriptive poet, the painter,
the sculptor, and indeed every earnest observer, the power most important
to cultivate, and, at the same time, hardest to acquire, is that of seeing what
is before him. Sight is a faculty; seeing, an art. The eye is a physical but not
a self-acting apparatus, and in general it sees only what it seeks. Like a
mirror, it reflects objects presented to it; but it may be as insensible as a
mirror, and not consciously perceive what it reflects. [Footnote: —I troer, at
Synets Sands er lagt i Oiet, Mens dette kun er Redskab. Synet strommer Fra
Sjaelens Dyb, og Oiets fine Nerver Gaae ud fra Hjernens hemmelige
Vaerksted. Henrik Hertz, Kong Rene's Datter, sc. ii.
wine that refreshed old Greece and Syria and Northern Africa have almost
ceased to flow, and the soils of those fair lands are turned to thirsty and
inhospitable deserts, the hyperborean regions of Europe have learnod to
conquer, or rather compensate, the rigors of climate, and have attained to a
material wealth and variety of product that, with all their natural
advantages, the granaries of the ancient world can hardly be said to have
enjoyed.
Observation of Nature.
In these pages it is my aim to stimulate, not to satisfy, curiosity, and it is
no part of my object to save my readers the labor of observation or of
thought. For labor is life, and Death lives where power lives unused.
[Footnote: Verses addressed by G. C. to Sir Walter Raleigh.—Haklutt, i., p.
608.]
Self is the schoolmaster whose lessons are best worth his wages; and
since the subject I am considering has not yet become a branch of formal
instruction, those whom it may interest can, fortunately, have no pedagogue
but themselves. To the natural philosopher, the descriptive poet, the painter,
the sculptor, and indeed every earnest observer, the power most important
to cultivate, and, at the same time, hardest to acquire, is that of seeing what
is before him. Sight is a faculty; seeing, an art. The eye is a physical but not
a self-acting apparatus, and in general it sees only what it seeks. Like a
mirror, it reflects objects presented to it; but it may be as insensible as a
mirror, and not consciously perceive what it reflects. [Footnote: —I troer, at
Synets Sands er lagt i Oiet, Mens dette kun er Redskab. Synet strommer Fra
Sjaelens Dyb, og Oiets fine Nerver Gaae ud fra Hjernens hemmelige
Vaerksted. Henrik Hertz, Kong Rene's Datter, sc. ii.
Page 44
In the material eye, you think, sight lodgeth! The EYE is but an organ.
SEEING streameth from the soul's inmost depths. The fine perceptive
Nerve springeth from the brain's mysterious workshop.]
It has been maintained by high authority, that the natural acuteness of our
sensuous faculties cannot be heightened by use, and hence, that the minutest
details of the image formed on the retina are as perfect in the most
untrained as in the most thoroughly disciplined organ. This may be
questioned, and it is agreed on all hands that the power of multifarious
perception and rapid discrimination may be immensely increased by well-
directed practice. [Footnote: Skill in marksmanship, whether with firearms
or with other projectile weapons, depends more upon the training of the eye
than is generally supposed, and I have often found particularly good shots
to possess an almost telescopic vision. In the ordinary use of the rifle, the
barrel is guided by the eye, but there are sportemen who fire with the butt of
the gun at the hip. In this case, as in the use of the sling, the lasso, and the
bolas, in hurling the knife (see Babinet, Lectures, vii., p. 84), in throwing
the boomerang, the javelin, or a stone, and in the employment of the
blowpipe and the bow, the movements of the hand and arm are guided by
that mysterious sympathy which exists between the eye and the unseeing
organs of the body. "Some men wonder whye, in casting a man's eye at the
marke, the hand should go streighte. Surely if he considered the nature of a
man's eye he would not wonder at it: for this I am certaine of, that no
servaunt to his maister, no childe to his father, is so obedient, as every
joynte and peece of the bodye is to do whatsover the eye biddes."—Roger
Ascham, Taxophilus, Book ii.
In shooting the tortoises of the Amazon and its tributaries, the Indians use
an arrow with a long twine and a float attached to it. Ave-Lallemant (Die
Benutzung der Palmen am Amazonenstrom, p. 32) thus describes their
mode of aiming: "As the arrow, if aimed directly at the floating tortoise,
SEEING streameth from the soul's inmost depths. The fine perceptive
Nerve springeth from the brain's mysterious workshop.]
It has been maintained by high authority, that the natural acuteness of our
sensuous faculties cannot be heightened by use, and hence, that the minutest
details of the image formed on the retina are as perfect in the most
untrained as in the most thoroughly disciplined organ. This may be
questioned, and it is agreed on all hands that the power of multifarious
perception and rapid discrimination may be immensely increased by well-
directed practice. [Footnote: Skill in marksmanship, whether with firearms
or with other projectile weapons, depends more upon the training of the eye
than is generally supposed, and I have often found particularly good shots
to possess an almost telescopic vision. In the ordinary use of the rifle, the
barrel is guided by the eye, but there are sportemen who fire with the butt of
the gun at the hip. In this case, as in the use of the sling, the lasso, and the
bolas, in hurling the knife (see Babinet, Lectures, vii., p. 84), in throwing
the boomerang, the javelin, or a stone, and in the employment of the
blowpipe and the bow, the movements of the hand and arm are guided by
that mysterious sympathy which exists between the eye and the unseeing
organs of the body. "Some men wonder whye, in casting a man's eye at the
marke, the hand should go streighte. Surely if he considered the nature of a
man's eye he would not wonder at it: for this I am certaine of, that no
servaunt to his maister, no childe to his father, is so obedient, as every
joynte and peece of the bodye is to do whatsover the eye biddes."—Roger
Ascham, Taxophilus, Book ii.
In shooting the tortoises of the Amazon and its tributaries, the Indians use
an arrow with a long twine and a float attached to it. Ave-Lallemant (Die
Benutzung der Palmen am Amazonenstrom, p. 32) thus describes their
mode of aiming: "As the arrow, if aimed directly at the floating tortoise,
Page 45
would strike it at a small angle and glance from its fiat and wet shell, the
archers have a peculiar method of shooting. They are able to calculate
exactly their own muscular effort, the velocity of the stream, the distance
and size of the tortoise, and they shoot the arrow directly up into the air, so
that it falls almost vertically upon the shell of the tortoise, and sticks in it."
Analogous calculations—if such physico-mental operations can property be
so called—are made in the use of other missiles; for no projectile flies in a
right line to its mark. But the exact training of the eye lies at the bottom of
them all, and marksmanship depends almost wholly upon the power of that
organ, whose directions the blind muscles implicitly follow. Savages
accustomed only to the use of the bow become good shots with firearms
after very little practice. It is perhaps not out of place to observe here that
our English word aim comes from the Latin aestimo, I calculate or estimate.
See Wedgwood's Dictionary of English Etymology, and the note to the
American edition, under Aim.
Another proof of the control of the limbs by the eye has been observed in
deaf-and-dumb schools, and others where pupils are first taught to write on
large slates or blackboards. The writing is in large characters, the small
letters being an inch or more high. They are formed with chalk or a slate
pencil firmly grasped in the fingers, and by appropriate motions of the
wrist, elbow, and shoulder, not of the finger joints. Nevertheless, when a
pen is put into the hand of a pupil thus taught, his handwriting, though
produced by a totally different set of muscles and muscular movements, is
identical in character with that which he has practised on the blackboard.
For a very remarkable account of the restoration of vision impaired from
age, by judicious training, see Lessons in Life, by Timothy Titcomb, lesson
xi. It has been much doubted whether the artists of the classic ages
possessed a more perfect light than those of modern times, or whether, in
executing their minute mosaics and gem engravings, they need magnifiers.
Glasses ground convex have been found at Pompeii, but they are too rudely
archers have a peculiar method of shooting. They are able to calculate
exactly their own muscular effort, the velocity of the stream, the distance
and size of the tortoise, and they shoot the arrow directly up into the air, so
that it falls almost vertically upon the shell of the tortoise, and sticks in it."
Analogous calculations—if such physico-mental operations can property be
so called—are made in the use of other missiles; for no projectile flies in a
right line to its mark. But the exact training of the eye lies at the bottom of
them all, and marksmanship depends almost wholly upon the power of that
organ, whose directions the blind muscles implicitly follow. Savages
accustomed only to the use of the bow become good shots with firearms
after very little practice. It is perhaps not out of place to observe here that
our English word aim comes from the Latin aestimo, I calculate or estimate.
See Wedgwood's Dictionary of English Etymology, and the note to the
American edition, under Aim.
Another proof of the control of the limbs by the eye has been observed in
deaf-and-dumb schools, and others where pupils are first taught to write on
large slates or blackboards. The writing is in large characters, the small
letters being an inch or more high. They are formed with chalk or a slate
pencil firmly grasped in the fingers, and by appropriate motions of the
wrist, elbow, and shoulder, not of the finger joints. Nevertheless, when a
pen is put into the hand of a pupil thus taught, his handwriting, though
produced by a totally different set of muscles and muscular movements, is
identical in character with that which he has practised on the blackboard.
For a very remarkable account of the restoration of vision impaired from
age, by judicious training, see Lessons in Life, by Timothy Titcomb, lesson
xi. It has been much doubted whether the artists of the classic ages
possessed a more perfect light than those of modern times, or whether, in
executing their minute mosaics and gem engravings, they need magnifiers.
Glasses ground convex have been found at Pompeii, but they are too rudely
Page 46
fashioned and too imperfectly polished to have been of any practical use for
optical purposes. But though the ancient artists may have had a microscopic
vision, their astronomers cannot have had a telescopic power of sight; for
they did not discover the satellites of Jupiter, which are often seen with the
naked eye at Oormeeah, in Persia, and sometimes, as I can testify by
personal observation, at Cairo.]
This exercise of the eye I desire to promote, and, next to moral and
religious doctrine, I know no more important practical lessons in this
earthly life of ours—which, to the wise man, is a school from the cradle to
the grave—than those relating to the employment of the sense of vision in
the study of nature.
The pursuit of physical geography, embracing actual observation of
terrestrial surface, affords to the eye the best general training that is
accessible to all. The majority of even cultivated men have not the time and
means of acquiring anything beyond a very superficial acquaintance with
any branch of physical knowledge.
Natural science has become so vastly extended, its recorded facts and its
unanswered questions so immensely multiplied, that every strictly scientific
man must be a specialist, and confine the researches of a whole life within a
comparatively narrow circle. The study I am recommending, in the view I
propose to take of it, is yet in that imperfectly developed state which allows
its votaries to occupy themselves with broad and general views attainable
by every person of culture, and it does not now require a knowledge of
special details which only years of application can master. It may be
profitably pursued by all; and every traveller, every lover of rural scenery,
every agriculturist, who will wisely use the gift of sight, may add valuable
contributions to the common stock of knowledge on a subject which, as I
hope to convince my readers, though long neglected, and now inartificially
optical purposes. But though the ancient artists may have had a microscopic
vision, their astronomers cannot have had a telescopic power of sight; for
they did not discover the satellites of Jupiter, which are often seen with the
naked eye at Oormeeah, in Persia, and sometimes, as I can testify by
personal observation, at Cairo.]
This exercise of the eye I desire to promote, and, next to moral and
religious doctrine, I know no more important practical lessons in this
earthly life of ours—which, to the wise man, is a school from the cradle to
the grave—than those relating to the employment of the sense of vision in
the study of nature.
The pursuit of physical geography, embracing actual observation of
terrestrial surface, affords to the eye the best general training that is
accessible to all. The majority of even cultivated men have not the time and
means of acquiring anything beyond a very superficial acquaintance with
any branch of physical knowledge.
Natural science has become so vastly extended, its recorded facts and its
unanswered questions so immensely multiplied, that every strictly scientific
man must be a specialist, and confine the researches of a whole life within a
comparatively narrow circle. The study I am recommending, in the view I
propose to take of it, is yet in that imperfectly developed state which allows
its votaries to occupy themselves with broad and general views attainable
by every person of culture, and it does not now require a knowledge of
special details which only years of application can master. It may be
profitably pursued by all; and every traveller, every lover of rural scenery,
every agriculturist, who will wisely use the gift of sight, may add valuable
contributions to the common stock of knowledge on a subject which, as I
hope to convince my readers, though long neglected, and now inartificially
Page 47
presented, is not only a very important but a very interesting field of
inquiry.
Measurement of Man's Influence.
The exact measurement of the geographical and climatic changes hitherto
effected by man is impracticable, and we possess, in relation to them, the
means of only qualitative, not quantitative analysis. The fact of such
revolutions is established partly by historical evidence, partly by analogical
deduction from effects produced, in our own time, by operations similar in
character to those which must have taken place in more or less remote ages
of human action. Both sources of information are alike defective in
precision; the latter, for general reasons too obvious to require specification;
the former, because the facts to which it bears testimony occurred before the
habit or the means of rigorously scientific observation upon any branch of
physical research, and especially upon climatic changes, existed.
UNCERTAINTY OF OUR HISTORICAL CONCLUSIONS ON
ANCIENT CLIMATES.
The invention of measures of heat and of atmospheric moisture, pressure,
and precipitation, is extremely recent. Hence, ancient physicists have left us
no thermometric or barometric records, no tables of the fall, evaporation,
and flow of waters, and even no accurate maps of coast lines and the course
of rivers. Their notices of these phenomena are almost wholly confined to
excessive and exceptional instances of high or of low temperatures,
extraordinary falls of rain and snow, and unusual floods or droughts. Our
knowledge of the meteorological condition of the earth, at any period more
than two centuries before our own time, is derived from these imperfect
inquiry.
Measurement of Man's Influence.
The exact measurement of the geographical and climatic changes hitherto
effected by man is impracticable, and we possess, in relation to them, the
means of only qualitative, not quantitative analysis. The fact of such
revolutions is established partly by historical evidence, partly by analogical
deduction from effects produced, in our own time, by operations similar in
character to those which must have taken place in more or less remote ages
of human action. Both sources of information are alike defective in
precision; the latter, for general reasons too obvious to require specification;
the former, because the facts to which it bears testimony occurred before the
habit or the means of rigorously scientific observation upon any branch of
physical research, and especially upon climatic changes, existed.
UNCERTAINTY OF OUR HISTORICAL CONCLUSIONS ON
ANCIENT CLIMATES.
The invention of measures of heat and of atmospheric moisture, pressure,
and precipitation, is extremely recent. Hence, ancient physicists have left us
no thermometric or barometric records, no tables of the fall, evaporation,
and flow of waters, and even no accurate maps of coast lines and the course
of rivers. Their notices of these phenomena are almost wholly confined to
excessive and exceptional instances of high or of low temperatures,
extraordinary falls of rain and snow, and unusual floods or droughts. Our
knowledge of the meteorological condition of the earth, at any period more
than two centuries before our own time, is derived from these imperfect
Page 48
details, from the vague statements of ancient historians and geographers in
regard to the volume of rivers and the relative extent of forest and cultivated
land, from the indications furnished by the history of the agriculture and
rural economy of past generations, and from other almost purely casual
sources of information. [Footnote: The subject of climatic change, with and
without reference to human action as a cause, has been much discussed by
Moreau de Jonnes, Dureau de la Malle, Arago, Humboldt, Fuster, Gasparin,
Becquerel, Schleiden, and many other writers in Europe, and by Noah
Webster, Forry, Drake, and others in America. Fraas has endeavored to
show, by the history of vegetation in Greece, not merely that clearing and
cultivation have affected climate, but that change of climate has essentially
modified the character of vegetable life. See his Klima und Pflansenwelt in
der Zeit.]
Among these latter we must rank certain newly laid open fields of
investigation, from which facts bearing on the point now under
consideration have been gathered. I allude to the discovery of artificial
objects in geological formations older than any hitherto recognized as
exhibiting traces of the existence of man; to the ancient lacustrine
habitations of Switzerland and of the terremare of Italy, [Footnote: See two
learned articles by Pigorini, in the Nuova Antologia for January and
October, 1870.] containing the implements of the occupants, remains of
their food, and other relics of human life; to the curious revelations of the
Kjokkenmoddinger, or heaps of kitchen refuse, in Denmark and elsewhere,
and of the peat mosses in the same and other northern countries; to the
dwellings and other evidences of the industry of man in remote ages
sometimes laid bare by the movement of sand dunes on the coasts of France
and of the North Sea; and to the facts disclosed on the tide-washed flats of
the latter shores by excavations in Halligs or inhabited mounds which were
probably raised before the era of the Roman Empire. [Footnote: For a very
picturesque description of the Halligs, see Pliny, N.H., Book xvi, c. 1.]
regard to the volume of rivers and the relative extent of forest and cultivated
land, from the indications furnished by the history of the agriculture and
rural economy of past generations, and from other almost purely casual
sources of information. [Footnote: The subject of climatic change, with and
without reference to human action as a cause, has been much discussed by
Moreau de Jonnes, Dureau de la Malle, Arago, Humboldt, Fuster, Gasparin,
Becquerel, Schleiden, and many other writers in Europe, and by Noah
Webster, Forry, Drake, and others in America. Fraas has endeavored to
show, by the history of vegetation in Greece, not merely that clearing and
cultivation have affected climate, but that change of climate has essentially
modified the character of vegetable life. See his Klima und Pflansenwelt in
der Zeit.]
Among these latter we must rank certain newly laid open fields of
investigation, from which facts bearing on the point now under
consideration have been gathered. I allude to the discovery of artificial
objects in geological formations older than any hitherto recognized as
exhibiting traces of the existence of man; to the ancient lacustrine
habitations of Switzerland and of the terremare of Italy, [Footnote: See two
learned articles by Pigorini, in the Nuova Antologia for January and
October, 1870.] containing the implements of the occupants, remains of
their food, and other relics of human life; to the curious revelations of the
Kjokkenmoddinger, or heaps of kitchen refuse, in Denmark and elsewhere,
and of the peat mosses in the same and other northern countries; to the
dwellings and other evidences of the industry of man in remote ages
sometimes laid bare by the movement of sand dunes on the coasts of France
and of the North Sea; and to the facts disclosed on the tide-washed flats of
the latter shores by excavations in Halligs or inhabited mounds which were
probably raised before the era of the Roman Empire. [Footnote: For a very
picturesque description of the Halligs, see Pliny, N.H., Book xvi, c. 1.]
Page 49
These remains are memorials of races which have left no written records,
which perished at a period beyond the reach of even historical tradition. The
plants and animals that furnished the relics found in the deposits were
certainly contemporaneous with man; for they are associated with his
works, and have evidently served his uses. In some cases, the animals
belonged to species well ascertained to be now altogether extinct; in some
others, both the animals and the vegetables, though extant elsewhere, have
ceased to inhabit the regions where their remains are discovered. From the
character of the artificial objects, as compared with others belonging to
known dates, or at least to known periods of civilization, ingenious
inferences have been drawn as to their age; and from the vegetable remains
which accompany them, as to the climates of Central and Northern Europe
at the time of their production.
There are, however, sources of error which have not always been
sufficiently guarded against in making these estimates. When a boat,
composed of several pieces of wood fastened together by pins of the same
material, is dug out of a bog, it is inferred that the vessel, and the skeletons
and implements found with it, belong to an age when the use of iron was
not known to the builders. But this conclusion is not warranted by the
simple fact that metals were not employed in its construction; for the
Nubians at this day build boats large enough to carry half a dozen persons
across the Nile, out of small pieces of acacia wood pinned together entirely
with wooden bolts, and large vessels of similar construction are used by the
islanders of the Malay archipelago. Nor is the occurrence of flint arrow
heads and knives, in conjunction with other evidences of human life,
conclusive proof as to the antiquity of the latter. Lyell informs us that some
Oriental tribes still continue to use the same stone implements as their
ancestors, "after that mighty empires, where the use of metals in the arts
was well known, had flourished for three thousand years in their
neighborhood;" [Footnote: Antiquity of Man, p. 377.] and the North
which perished at a period beyond the reach of even historical tradition. The
plants and animals that furnished the relics found in the deposits were
certainly contemporaneous with man; for they are associated with his
works, and have evidently served his uses. In some cases, the animals
belonged to species well ascertained to be now altogether extinct; in some
others, both the animals and the vegetables, though extant elsewhere, have
ceased to inhabit the regions where their remains are discovered. From the
character of the artificial objects, as compared with others belonging to
known dates, or at least to known periods of civilization, ingenious
inferences have been drawn as to their age; and from the vegetable remains
which accompany them, as to the climates of Central and Northern Europe
at the time of their production.
There are, however, sources of error which have not always been
sufficiently guarded against in making these estimates. When a boat,
composed of several pieces of wood fastened together by pins of the same
material, is dug out of a bog, it is inferred that the vessel, and the skeletons
and implements found with it, belong to an age when the use of iron was
not known to the builders. But this conclusion is not warranted by the
simple fact that metals were not employed in its construction; for the
Nubians at this day build boats large enough to carry half a dozen persons
across the Nile, out of small pieces of acacia wood pinned together entirely
with wooden bolts, and large vessels of similar construction are used by the
islanders of the Malay archipelago. Nor is the occurrence of flint arrow
heads and knives, in conjunction with other evidences of human life,
conclusive proof as to the antiquity of the latter. Lyell informs us that some
Oriental tribes still continue to use the same stone implements as their
ancestors, "after that mighty empires, where the use of metals in the arts
was well known, had flourished for three thousand years in their
neighborhood;" [Footnote: Antiquity of Man, p. 377.] and the North
Page 50
American Indians now manufacture weapons of stone, and even of glass,
chipping them in the latter case out of the bottoms of thick bottles, with
great facility. [Footnote: "One of the Indians seated himself near me, and
made from a fragment of quartz, with a simple piece of round bone, one end
of which was hemispherical, with a small crease in it (as if worn by a
thread) the sixteenth of an inch deep, an arrow head which was very sharp
and piercing, and such as they use on all their arrows. The skill and rapidity
with which it was made, without a blow, but by simply breaking the sharp
edges with the creased bone by the strength of his hands—for the crease
merely served to prevent the instrument from slipping, affording no
leverage—was remarkable."—Reports of Explorations and Surveys for
Pacific Railroad, vol. ii., 1855, Lieut. Beckwith'S Report, p. 43. See also
American Naturalist for May, 1870, and especially Stevens, Flint Chips,
London, 1870, pp. 77 et seq.
Mariette Bey lately saw an Egyptian barber shave the head of an Arab
with a flint razor.]
We may also be misled by our ignorance of the commercial relations
existing between savage tribes. Extremely rude nations, in spite of their
jealousies and their perpetual wars, sometimes contrive to exchange the
products of provinces very widely separated from each other. The mounds
of Ohio contain pearls, thought to be marine, which must have come from
the Gulf of Mexico, or perhaps even from California, and the knives and
pipes found in the same graves are often formed of far-fetched material, that
was naturally paid for by some home product exported to the locality
whence the material was derived. The art of preserving fish, flesh, and fowl
by drying and smoking is widely diffused, and of great antiquity. The
Indians of Long Island Sound are said to have carried on a trade in dried
shell fish with tribes residing very far inland. From the earliest ages, the
inhabitants of the Faroe and Orkney Islands, and of the opposite mainland
chipping them in the latter case out of the bottoms of thick bottles, with
great facility. [Footnote: "One of the Indians seated himself near me, and
made from a fragment of quartz, with a simple piece of round bone, one end
of which was hemispherical, with a small crease in it (as if worn by a
thread) the sixteenth of an inch deep, an arrow head which was very sharp
and piercing, and such as they use on all their arrows. The skill and rapidity
with which it was made, without a blow, but by simply breaking the sharp
edges with the creased bone by the strength of his hands—for the crease
merely served to prevent the instrument from slipping, affording no
leverage—was remarkable."—Reports of Explorations and Surveys for
Pacific Railroad, vol. ii., 1855, Lieut. Beckwith'S Report, p. 43. See also
American Naturalist for May, 1870, and especially Stevens, Flint Chips,
London, 1870, pp. 77 et seq.
Mariette Bey lately saw an Egyptian barber shave the head of an Arab
with a flint razor.]
We may also be misled by our ignorance of the commercial relations
existing between savage tribes. Extremely rude nations, in spite of their
jealousies and their perpetual wars, sometimes contrive to exchange the
products of provinces very widely separated from each other. The mounds
of Ohio contain pearls, thought to be marine, which must have come from
the Gulf of Mexico, or perhaps even from California, and the knives and
pipes found in the same graves are often formed of far-fetched material, that
was naturally paid for by some home product exported to the locality
whence the material was derived. The art of preserving fish, flesh, and fowl
by drying and smoking is widely diffused, and of great antiquity. The
Indians of Long Island Sound are said to have carried on a trade in dried
shell fish with tribes residing very far inland. From the earliest ages, the
inhabitants of the Faroe and Orkney Islands, and of the opposite mainland
Page 51
coasts, have smoked wild fowl and other flesh. Hence it is possible that the
animal and the vegetable food, the remains of which are found in the
ancient deposits I am speaking of, may sometimes have been brought from
climates remote from that where it was consumed.
The most important, as well as the most trustworthy conclusions with
respect to the climate of ancient Europe and Asia, are those drawn from the
accounts given by the classical writers of the growth of cultivated plants;
but these are by no means free from uncertainty, because we can seldom be
sure of an identity of species, almost never of an identity of race or variety,
between vegetables known to the agriculturists of Greece and Rome and
those of modern times which are thought most nearly to resemble them.
Besides this, there is always room for doubt whether the habits of plants
long grown in different countries may not have been so changed by
domestication or by natural selection, that the conditions of temperature and
humidity which they required twenty centuries ago were different from
those at present demanded for their advantageous cultivation. [Footnote:
Probably no cultivated vegetable affords so good an opportunity of studying
the law of acclimation of plants as maize or Indian corn. Maize is grown
from the tropics to at least lat. 47 degrees in Northeastern America, and
farther north in Europe. Every two or three degrees of latitude brings you to
a new variety with new climatic adaptations, and the capacity of the plant to
accommodate itself to new conditions of temperature and season seems
almost unlimited.
Many persons now living remember that, when the common tomato was
first introduced into Northern New England, it often failed to ripen; but, in
the course of a very few years, it completely adapted itself to the climate,
and now not only matures both its fruit and its seeds with as much certainty
as any cultivated vegetable, but regularly propagates itself by self-sown
animal and the vegetable food, the remains of which are found in the
ancient deposits I am speaking of, may sometimes have been brought from
climates remote from that where it was consumed.
The most important, as well as the most trustworthy conclusions with
respect to the climate of ancient Europe and Asia, are those drawn from the
accounts given by the classical writers of the growth of cultivated plants;
but these are by no means free from uncertainty, because we can seldom be
sure of an identity of species, almost never of an identity of race or variety,
between vegetables known to the agriculturists of Greece and Rome and
those of modern times which are thought most nearly to resemble them.
Besides this, there is always room for doubt whether the habits of plants
long grown in different countries may not have been so changed by
domestication or by natural selection, that the conditions of temperature and
humidity which they required twenty centuries ago were different from
those at present demanded for their advantageous cultivation. [Footnote:
Probably no cultivated vegetable affords so good an opportunity of studying
the law of acclimation of plants as maize or Indian corn. Maize is grown
from the tropics to at least lat. 47 degrees in Northeastern America, and
farther north in Europe. Every two or three degrees of latitude brings you to
a new variety with new climatic adaptations, and the capacity of the plant to
accommodate itself to new conditions of temperature and season seems
almost unlimited.
Many persons now living remember that, when the common tomato was
first introduced into Northern New England, it often failed to ripen; but, in
the course of a very few years, it completely adapted itself to the climate,
and now not only matures both its fruit and its seeds with as much certainty
as any cultivated vegetable, but regularly propagates itself by self-sown
Page 52
seed. Meteorological observations, however, do not show any amelioration
of the summer climate in those States within that period.
It may be said that these cases—and indeed all cases of a supposed
acclimation consisting in physiological changes—are instances of the
origination of new varieties by natural selection, the hardier maize, tomato,
and other vegetables of the North, being the progeny of seeds of individuals
endowed, exceptionally, with greater power of resisting cold than belongs
in general to the species which produced them. But, so far as the evidence
of change of climate, from a difference in vegetable growth, is concerned, it
is immaterial whether we adopt this view or maintain the older and more
familiar doctrine of a local modification of character in the plants in
question.
Maize and the tomato, if not new to human use, have not been long
known to civilization, and were, very probably, reclaimed and domesticated
at a much more recent period than the plants which form the great staples of
agricultural husbandry in Europe and Asia. Is the great power of
accommodation to climate possessed by them due to this circumstance
There is some reason to suppose that the character of maize has been
sensibly changed by cultivation in South America; for, according to
Tschudi, the ears of this grain found in old Peruvian tombs belong to
varieties not now known in Peru.—Travels in Peru, chap. vii. See important
observations in Schubeler, Die Pflanzenwelt Norwegans (Allgemeiner
Theil), Christinania, 1873, 77 and following pp.] Even if we suppose an
identity of species, of race, and of habit to be established between a given
ancient and modern plant, the negative fact that the latter will not grow now
where it flourished two thousand years ago does not in all cases prove a
change of climate. The same result might follow from the exhaustion of the
soil, [Footnote: The cultivation of madder is said to have been introduced
into Europe by an Oriental in the year 1765, and it was first planted in the
of the summer climate in those States within that period.
It may be said that these cases—and indeed all cases of a supposed
acclimation consisting in physiological changes—are instances of the
origination of new varieties by natural selection, the hardier maize, tomato,
and other vegetables of the North, being the progeny of seeds of individuals
endowed, exceptionally, with greater power of resisting cold than belongs
in general to the species which produced them. But, so far as the evidence
of change of climate, from a difference in vegetable growth, is concerned, it
is immaterial whether we adopt this view or maintain the older and more
familiar doctrine of a local modification of character in the plants in
question.
Maize and the tomato, if not new to human use, have not been long
known to civilization, and were, very probably, reclaimed and domesticated
at a much more recent period than the plants which form the great staples of
agricultural husbandry in Europe and Asia. Is the great power of
accommodation to climate possessed by them due to this circumstance
There is some reason to suppose that the character of maize has been
sensibly changed by cultivation in South America; for, according to
Tschudi, the ears of this grain found in old Peruvian tombs belong to
varieties not now known in Peru.—Travels in Peru, chap. vii. See important
observations in Schubeler, Die Pflanzenwelt Norwegans (Allgemeiner
Theil), Christinania, 1873, 77 and following pp.] Even if we suppose an
identity of species, of race, and of habit to be established between a given
ancient and modern plant, the negative fact that the latter will not grow now
where it flourished two thousand years ago does not in all cases prove a
change of climate. The same result might follow from the exhaustion of the
soil, [Footnote: The cultivation of madder is said to have been introduced
into Europe by an Oriental in the year 1765, and it was first planted in the
Page 53
neighborhood of Avignon. Of course, it has been grown in that district for
less than a century; but upon soils where it has been a frequent crop, it is
already losing much of its coloring properties.—Lavergne, Economic
Rurale de la France, pp. 250-201.
I believe there is no doubt that the cultivation of madder in the vicinity of
Avignon is of recent introduction; but it is certain that it was grown by the
ancient Romans, and throughout nearly all Europe in the middle ages. The
madder brought from Persia to France, may belong to a different species, or
at least variety.] or from a change in the quantity of moisture it habitually
contains. After a district of country has been completely or even partially
cleared of its forest growth, and brought under cultivation, the drying of the
soil, under favorable circumstances, goes on for generations, perhaps for
ages. [Footnote: In many parts of New England there are tracts, many
square miles in extent and presenting all varieties of surface and exposure,
which were partially cleared sixty or seventy years ago, and where little or
no change in the proportion of cultivated ground, pasturage, and woodland
has taken place since. In some cases, these tracts compose basins apparently
scarcely at all exposed to any local influence in the way of percolation or
infiltration of water towards or from neighboring valleys. But in such
situations, apart from accidental disturbances, the ground is growing drier
and drier from year to year, springs are still disappearing, and rivulets still
diminishing in their summer supply of water. A probable explanation of this
is to be found in the rapid drainage of the surface of cleared ground, which
prevents the subterranean natural reservoirs, whether cavities or merely
strata of bibulous earth, from filling up. How long this process is to last
before an equilibrium is reached, none can say. It may be, for years; it may
be, for centuries.
Livingstone states facts which strongly favor the supposition that a
secular desiccation is still going on in central Africa, and there is reason to
less than a century; but upon soils where it has been a frequent crop, it is
already losing much of its coloring properties.—Lavergne, Economic
Rurale de la France, pp. 250-201.
I believe there is no doubt that the cultivation of madder in the vicinity of
Avignon is of recent introduction; but it is certain that it was grown by the
ancient Romans, and throughout nearly all Europe in the middle ages. The
madder brought from Persia to France, may belong to a different species, or
at least variety.] or from a change in the quantity of moisture it habitually
contains. After a district of country has been completely or even partially
cleared of its forest growth, and brought under cultivation, the drying of the
soil, under favorable circumstances, goes on for generations, perhaps for
ages. [Footnote: In many parts of New England there are tracts, many
square miles in extent and presenting all varieties of surface and exposure,
which were partially cleared sixty or seventy years ago, and where little or
no change in the proportion of cultivated ground, pasturage, and woodland
has taken place since. In some cases, these tracts compose basins apparently
scarcely at all exposed to any local influence in the way of percolation or
infiltration of water towards or from neighboring valleys. But in such
situations, apart from accidental disturbances, the ground is growing drier
and drier from year to year, springs are still disappearing, and rivulets still
diminishing in their summer supply of water. A probable explanation of this
is to be found in the rapid drainage of the surface of cleared ground, which
prevents the subterranean natural reservoirs, whether cavities or merely
strata of bibulous earth, from filling up. How long this process is to last
before an equilibrium is reached, none can say. It may be, for years; it may
be, for centuries.
Livingstone states facts which strongly favor the supposition that a
secular desiccation is still going on in central Africa, and there is reason to
Page 54
suspect that a like change is taking place in California. When the regions
where the earth is growing drier were cleared of wood, or, indeed, whether
forests ever grew there, we are unable to say, but the change appears to have
been long in progress. A similar revolution appears to have occurred in
Arabia Petraea. In many of the wadis, and particularly in the gorges
between Wadi Feiran and Wadi Esh Sheikh, there are water-worn banks
showing that, at no very remote period, the winter floods must have risen
fifty feet in channels where the growth of acacias and tamarisks and the
testimony of the Arabs concur to prove that they have not risen six feet
within the memory or tradition of the present inhabitants. Recent travellers
have discovered traces of extensive ancient cultivation, and of the former
existence of large towns in the Tih desert, in localities where all agriculture
is now impossible for want of water. Is this drought due to the destruction
of ancient forests or to some other cause?
For important observations on supposed changes of climate in our
Western prairie region, from cultivation of the soil and the introduction of
domestic cattle, see Bryant's valuable Forest Trees, 1871, chapter v., and
Hayden, Preliminary Report on Survey of Wyoming, p. 455. Some
physicists believe that the waters of our earth are, from chemical of other
less known causes, diminishing by entering into new inorganic
combinations, and that this element will finally disappear from the globe.]
In other cases, from injudicioua husbandry, or the diversion or choking
up of natural water-courses, it may become more highly charged with
humidity. An increase or diminution of the moisture of a soil almost
necessarily supposes an elevation or a depression of its winter or its
summer heat, and of its extreme if not of its mean annual temperature,
though such elevation or depression may be so slight as not sensibly to raise
or lower the mercury in a thermometer exposed to the open air. Any of these
causes, more or less humidity, or more or less warmth of soil, would affect
where the earth is growing drier were cleared of wood, or, indeed, whether
forests ever grew there, we are unable to say, but the change appears to have
been long in progress. A similar revolution appears to have occurred in
Arabia Petraea. In many of the wadis, and particularly in the gorges
between Wadi Feiran and Wadi Esh Sheikh, there are water-worn banks
showing that, at no very remote period, the winter floods must have risen
fifty feet in channels where the growth of acacias and tamarisks and the
testimony of the Arabs concur to prove that they have not risen six feet
within the memory or tradition of the present inhabitants. Recent travellers
have discovered traces of extensive ancient cultivation, and of the former
existence of large towns in the Tih desert, in localities where all agriculture
is now impossible for want of water. Is this drought due to the destruction
of ancient forests or to some other cause?
For important observations on supposed changes of climate in our
Western prairie region, from cultivation of the soil and the introduction of
domestic cattle, see Bryant's valuable Forest Trees, 1871, chapter v., and
Hayden, Preliminary Report on Survey of Wyoming, p. 455. Some
physicists believe that the waters of our earth are, from chemical of other
less known causes, diminishing by entering into new inorganic
combinations, and that this element will finally disappear from the globe.]
In other cases, from injudicioua husbandry, or the diversion or choking
up of natural water-courses, it may become more highly charged with
humidity. An increase or diminution of the moisture of a soil almost
necessarily supposes an elevation or a depression of its winter or its
summer heat, and of its extreme if not of its mean annual temperature,
though such elevation or depression may be so slight as not sensibly to raise
or lower the mercury in a thermometer exposed to the open air. Any of these
causes, more or less humidity, or more or less warmth of soil, would affect
Page 55
the growth both of wild and of cultivated vegetation, and consequently,
without any appreciable change in atmospheric temperature, precipitation,
or evaporation, plants of a particular species might cease to be
advantageously cultivated where they had once been easily reared.
[Footnote: The soil of newly subdued countries is generally highly
favorable to the growth of the fruits of the garden and the orchard, but
usually becomes much less so in a very few years. Plums, of many
varieties, were formerly grown, in great perfection and abundance, in many
parts of New England where at present they can scarcely be reared at all;
and the peach, which, a generation or two ago, succeeded admirably in the
southern portion of the same States, has almost ceased to be cultivated
there. The disappearance of these fruits is partly due to the ravages of
insects, which have in later years attacked them; but this is evidently by no
means the sole, or even the principal cause of their decay. In these cases, it
is not to the exhaustion of the particular acres on which the fruit trees have
grown that we are to ascribe their degeneracy, but to a general change in the
condition of the soil or the air; for it is equally impossible to rear them
successfully on absolutely new land in the neighborhood of grounds where,
not long since, they bore the finest fruit.
I remember being told, many years ago, by intelligent early settlers of the
State of Ohio, that the apple trees raised there from seed sown soon after the
land was cleared, bore fruit in less than half the time required to bring to
bearing those reared from seed gown when the ground had been twenty
years under cultivation. Analogous changes occur slowly and almost
imperceptibly even in spontaneous vegetation. In the peat mosses of
Denmark, Scotch firs and other trees not now growing in the same
localities, are found in abundance. Every generation of trees leaves the soil
in a different state from that in which it found it; every tree that springs up
in a group of trees of another species than its own, grows under different
influences of light and shade and atmosphere from its predecessors. Hence
without any appreciable change in atmospheric temperature, precipitation,
or evaporation, plants of a particular species might cease to be
advantageously cultivated where they had once been easily reared.
[Footnote: The soil of newly subdued countries is generally highly
favorable to the growth of the fruits of the garden and the orchard, but
usually becomes much less so in a very few years. Plums, of many
varieties, were formerly grown, in great perfection and abundance, in many
parts of New England where at present they can scarcely be reared at all;
and the peach, which, a generation or two ago, succeeded admirably in the
southern portion of the same States, has almost ceased to be cultivated
there. The disappearance of these fruits is partly due to the ravages of
insects, which have in later years attacked them; but this is evidently by no
means the sole, or even the principal cause of their decay. In these cases, it
is not to the exhaustion of the particular acres on which the fruit trees have
grown that we are to ascribe their degeneracy, but to a general change in the
condition of the soil or the air; for it is equally impossible to rear them
successfully on absolutely new land in the neighborhood of grounds where,
not long since, they bore the finest fruit.
I remember being told, many years ago, by intelligent early settlers of the
State of Ohio, that the apple trees raised there from seed sown soon after the
land was cleared, bore fruit in less than half the time required to bring to
bearing those reared from seed gown when the ground had been twenty
years under cultivation. Analogous changes occur slowly and almost
imperceptibly even in spontaneous vegetation. In the peat mosses of
Denmark, Scotch firs and other trees not now growing in the same
localities, are found in abundance. Every generation of trees leaves the soil
in a different state from that in which it found it; every tree that springs up
in a group of trees of another species than its own, grows under different
influences of light and shade and atmosphere from its predecessors. Hence
Page 56
the succession of crops, which occurs in all natural forests, seems to be due
rather to changes of condition than of climate. See chapter iii., post.]
Uncertainty of Modern Meteorology.
We are very imperfectly acquainted with the present mean and extreme
temperature, or the precipitation and the evaporation of any extensive
region, even in countries most densely peopled and best supplied with
instruments and observers. The progress of science is constantly detecting
errors of method in older observations, and many laboriously constructed
tables of meteorological phenomena are now thrown aside as fallacious, and
therefore worse than useless, because some condition necessary to secure
accuracy of result was neglected, in obtaining and recording the data on
which they were founded.
To take a familiar instance: it is but recently that attention has been
drawn to the great influence of slight differences in station upon the results
of observations of temperature and precipitation. Two thermometers hung
but a few hundred yards from each other differ not unfrequently five,
sometimes even ten degrees in their readings; [Footnote: Tyndall, in a
lecture on Radiation, expresses the opinion that from ten to fifteen per cent.
of the heat radiated from the earth is absorbed by aqueous vapor within ten
feet of the earth's surface.—Fragments of Science, 3d edition, London,
1871, p. 203. Thermometers at most meteorological stations, when not
suspended at points regulated by the mere personal convenience of the
observer, are hung from 20 to 40 feet above the ground. In such positions
they are less exposed to disturbance from the action of surrounding bodies
than at a lower level, and their indications are consequently more uniform;
but according to Tyndall's views they do not mark the temperature of the
atmospheric stratum in which nearly all the vegetables useful to man,
except forest trees, bud and blossom and ripen, and in which a vast majority
rather to changes of condition than of climate. See chapter iii., post.]
Uncertainty of Modern Meteorology.
We are very imperfectly acquainted with the present mean and extreme
temperature, or the precipitation and the evaporation of any extensive
region, even in countries most densely peopled and best supplied with
instruments and observers. The progress of science is constantly detecting
errors of method in older observations, and many laboriously constructed
tables of meteorological phenomena are now thrown aside as fallacious, and
therefore worse than useless, because some condition necessary to secure
accuracy of result was neglected, in obtaining and recording the data on
which they were founded.
To take a familiar instance: it is but recently that attention has been
drawn to the great influence of slight differences in station upon the results
of observations of temperature and precipitation. Two thermometers hung
but a few hundred yards from each other differ not unfrequently five,
sometimes even ten degrees in their readings; [Footnote: Tyndall, in a
lecture on Radiation, expresses the opinion that from ten to fifteen per cent.
of the heat radiated from the earth is absorbed by aqueous vapor within ten
feet of the earth's surface.—Fragments of Science, 3d edition, London,
1871, p. 203. Thermometers at most meteorological stations, when not
suspended at points regulated by the mere personal convenience of the
observer, are hung from 20 to 40 feet above the ground. In such positions
they are less exposed to disturbance from the action of surrounding bodies
than at a lower level, and their indications are consequently more uniform;
but according to Tyndall's views they do not mark the temperature of the
atmospheric stratum in which nearly all the vegetables useful to man,
except forest trees, bud and blossom and ripen, and in which a vast majority
Page 57
of the ordinary operations of material life are performed. They give the rise
and fall of the mercury at heights arbitrarily taken, without reference to the
relations of temperature to human interests, or to any other scientific
consideration than a somewhat less liability to accidental disturbance.] and
when we are told that the annual fall of rain on the roof of the observatory
at Paris is two inches less than on the ground by the side of it, we may see
that the height of the rain-gauge above the earth is a point of much
consequence in making estimates from its measurements. [Footnote:
Careful observations by the late lamented Dallas Bache appeared to show
that there is no such difference in the quantity of precipitation falling at
slightly different levels as has been generally supposed. The apparent
difference was ascribed by Prof. Bache to the irregular distribution of the
drops of rain and flakes of snow, exposed, as they are, to local disturbances
by the currents of air around the corners of buildings or other accidents of
the surface. This consideration much increases the importance of great care
in the selection of positions for rain-gauges. But Mr. Bache's conclusions
seem not to be accepted by late experimenters in England. See Quarterly
Journal of Science for January, 1871, p. 123.]
The data from which results have been deduced with respect to the
hygrometrical and thermometrical conditions, to the climate in short, of
different countries, have very often been derived from observations at
single points in cities or districts separated by considerable distances. The
tendency of errors and accidents to balance each other authorizes us,
indeed, to entertain greater confidence than we could otherwise feel in the
conclusions drawn from such tables; but it is in the highest degree probable
that they would be much modified by more numerous series of
observations, at different stations within narrow limits. [Footnote: The
nomenclature of meteorology is vague and sometimes equivocal. Not long
since, it was suspected that the observers reporting to a scientific institution
did not agree in their understanding of the mode of expressing the direction
and fall of the mercury at heights arbitrarily taken, without reference to the
relations of temperature to human interests, or to any other scientific
consideration than a somewhat less liability to accidental disturbance.] and
when we are told that the annual fall of rain on the roof of the observatory
at Paris is two inches less than on the ground by the side of it, we may see
that the height of the rain-gauge above the earth is a point of much
consequence in making estimates from its measurements. [Footnote:
Careful observations by the late lamented Dallas Bache appeared to show
that there is no such difference in the quantity of precipitation falling at
slightly different levels as has been generally supposed. The apparent
difference was ascribed by Prof. Bache to the irregular distribution of the
drops of rain and flakes of snow, exposed, as they are, to local disturbances
by the currents of air around the corners of buildings or other accidents of
the surface. This consideration much increases the importance of great care
in the selection of positions for rain-gauges. But Mr. Bache's conclusions
seem not to be accepted by late experimenters in England. See Quarterly
Journal of Science for January, 1871, p. 123.]
The data from which results have been deduced with respect to the
hygrometrical and thermometrical conditions, to the climate in short, of
different countries, have very often been derived from observations at
single points in cities or districts separated by considerable distances. The
tendency of errors and accidents to balance each other authorizes us,
indeed, to entertain greater confidence than we could otherwise feel in the
conclusions drawn from such tables; but it is in the highest degree probable
that they would be much modified by more numerous series of
observations, at different stations within narrow limits. [Footnote: The
nomenclature of meteorology is vague and sometimes equivocal. Not long
since, it was suspected that the observers reporting to a scientific institution
did not agree in their understanding of the mode of expressing the direction
Page 58
of the wind prescribed by their instructions. It was found, upon inquiry, that
very many of them used the names of the compass-points to indicate the
quarter FROM which the wind blew, while others employed them to signify
the quarter TOWARDS which the atmospheric currents were moving. In
some instances, the observers were no longer within the reach of inquiry,
and of course their tables of the wind were of no value. "Winds," says Mrs.
Somerville, "are named from the points whence they blow, currents exactly
the reverse. An easterly wind comes from the east; whereas on easterly
current comes from the west, and flows towards the east."—Physical
Geography, p. 229.
There is no philological ground for this distinction, and it probably
originated in a confusion of the terminations -WARDLY and -ERLY, both of
which are modern. The root of the former ending implies the direction TO
or TO-WARDS which motion is supposed. It corresponds to, and is
probably allied with, the Latin VERSUS. The termination -ERLY is a
corruption or softening of -ERNLY, easterly for easternly, and many authors
of the nineteenth century so write it. In Haklnyt (i., p. 2), EASTERLY is
applied to place, "EASTERLY bounds," and means EASTERN. In a
passage in Drayton, "EASTERLY winds" must mean winds FROM the east;
but the same author, in speaking of nations, uses NORTHERLY for
NORTHERN. Lakewell says: "The sonne cannot goe more SOUTHERNLY
from us, nor come more NORTHERNLY towards us." Holland, in his
translation of Pliny, referring to the moon, has: "When shee is
NORTHERLY," and "shee is gone SOUTHERLY." Richardson, to whom I
am indebted for the above citations, quotes a passage from Dampier where
WESTERLY is applied to the wind, but the context does not determine the
direction. The only example of the termination -WARDLY given by this
lexicographer is from Donne, where it means TOWARDS the west.
very many of them used the names of the compass-points to indicate the
quarter FROM which the wind blew, while others employed them to signify
the quarter TOWARDS which the atmospheric currents were moving. In
some instances, the observers were no longer within the reach of inquiry,
and of course their tables of the wind were of no value. "Winds," says Mrs.
Somerville, "are named from the points whence they blow, currents exactly
the reverse. An easterly wind comes from the east; whereas on easterly
current comes from the west, and flows towards the east."—Physical
Geography, p. 229.
There is no philological ground for this distinction, and it probably
originated in a confusion of the terminations -WARDLY and -ERLY, both of
which are modern. The root of the former ending implies the direction TO
or TO-WARDS which motion is supposed. It corresponds to, and is
probably allied with, the Latin VERSUS. The termination -ERLY is a
corruption or softening of -ERNLY, easterly for easternly, and many authors
of the nineteenth century so write it. In Haklnyt (i., p. 2), EASTERLY is
applied to place, "EASTERLY bounds," and means EASTERN. In a
passage in Drayton, "EASTERLY winds" must mean winds FROM the east;
but the same author, in speaking of nations, uses NORTHERLY for
NORTHERN. Lakewell says: "The sonne cannot goe more SOUTHERNLY
from us, nor come more NORTHERNLY towards us." Holland, in his
translation of Pliny, referring to the moon, has: "When shee is
NORTHERLY," and "shee is gone SOUTHERLY." Richardson, to whom I
am indebted for the above citations, quotes a passage from Dampier where
WESTERLY is applied to the wind, but the context does not determine the
direction. The only example of the termination -WARDLY given by this
lexicographer is from Donne, where it means TOWARDS the west.
Page 59
Shakespeare, in Hamlet(v., ii.), uses NORTHERLY wind for wind FROM
the north. Milton does not employ either of these terminations, nor were
they known to the Anglo-Saxons, who, however, had adjectives of direction
in -AN or -EN, -ern and -weard, the last always meaning the point
TOWARDS which motion in supposed, the others that FROM which it
proceeds. The vocabulary of science has no specific name for one of the
most important phenomena in meteorology—I mean for watery vapor
condensed and rendered visible by cold. The Latins expressed this condition
of water by the word vapor. For INVISIBLE vapor they had no name,
because they did not know that it existed, and Van Helmont was obliged to
invent a word, gas, as a generic name for watery and other fluids in the
invisible state. The moderns have perverted the meaning of the word vapor,
and in science its use is confined to express water in the gaseous and
invisible state. When vapor in rendered visible by condensation, we call it
fog or mist—between which two words there is no clearly established
distinction—if it is lying on or near the surface of the earth or of water;
when it floats in the air we call it cloud. But these words express the form
and position of the humid aggregation, not the condition of the water-
globules which compose it. The breath from our mouths, the steam from an
engine, thrown out into cold air, become visible, and consist of water in the
same state as in fog or cloud; but we do not apply those terms to these
phenomena. It would be an improvement in meteorological nomenclature to
restore vapor to its original meaning, and to employ a new word, such for
example as hydrogas, to explain the new scientific idea of water in the
invisible state.]
There is one branch of research which is of the utmost importance in
reference to these questions, but which, from the great difficulty of direct
observation upon it, has been less successfully studied than almost any
other problem of physical science. I refer to the proportions between
precipitation, superficial drainage, absorption, and evaporation. Precise
the north. Milton does not employ either of these terminations, nor were
they known to the Anglo-Saxons, who, however, had adjectives of direction
in -AN or -EN, -ern and -weard, the last always meaning the point
TOWARDS which motion in supposed, the others that FROM which it
proceeds. The vocabulary of science has no specific name for one of the
most important phenomena in meteorology—I mean for watery vapor
condensed and rendered visible by cold. The Latins expressed this condition
of water by the word vapor. For INVISIBLE vapor they had no name,
because they did not know that it existed, and Van Helmont was obliged to
invent a word, gas, as a generic name for watery and other fluids in the
invisible state. The moderns have perverted the meaning of the word vapor,
and in science its use is confined to express water in the gaseous and
invisible state. When vapor in rendered visible by condensation, we call it
fog or mist—between which two words there is no clearly established
distinction—if it is lying on or near the surface of the earth or of water;
when it floats in the air we call it cloud. But these words express the form
and position of the humid aggregation, not the condition of the water-
globules which compose it. The breath from our mouths, the steam from an
engine, thrown out into cold air, become visible, and consist of water in the
same state as in fog or cloud; but we do not apply those terms to these
phenomena. It would be an improvement in meteorological nomenclature to
restore vapor to its original meaning, and to employ a new word, such for
example as hydrogas, to explain the new scientific idea of water in the
invisible state.]
There is one branch of research which is of the utmost importance in
reference to these questions, but which, from the great difficulty of direct
observation upon it, has been less successfully studied than almost any
other problem of physical science. I refer to the proportions between
precipitation, superficial drainage, absorption, and evaporation. Precise
Page 60
actual measurement of these quantities upon even a single acre of ground is
impossible; and in all cabinet experiments on the subject, the conditions of
the surface observed are so different from those which occur in nature, that
we cannot safely reason from one case to the other. In nature, the inclination
and exposure of the ground, the degree of freedom or obstruction of the
flow of water over the surface, the composition and density of the soil, the
presence or absence of perforations by worms and small burrowing
quadrupeds—upon which the permeability of the ground by water and its
power of absorbing and retaining or transmitting moisture depend—its
temperature, the dryness or saturation of the subsoil, vary at comparatively
short distances; and though the precipitation upon very small geographical
basins and the superficial flow from them may be estimated with an
approach to precision, yet even here we have no present means of knowing
how much of the water absorbed by the earth is restored to the atmosphere
by evaporation, and how much carried off by infiltration or other modes of
underground discharge. When, therefore, we attempt to use the phenomena
observed on a few square or cubic yards of earth, as a basis of reasoning
upon the meteorology of a province, it is evident that our data must be
insufficient to warrant positive general conclusions. In discussing the
climatology of whole countries, or even of comparatively small local
divisions, we may safely say that none can tell what percentage of the water
they receive from the atmosphere is evaporated; what absorbed by the
ground and conveyed off by subterranean conduits; what carried down to
the sea by superficial channels; what drawn from the earth or the air by a
given extent of forest, of short pasture vegetation, or of tall meadow-grass;
what given out again by surfaces so covered, or by bare ground of various
textures and composition, under different conditions of atmospheric
temperature, pressure, and humidity; or what is the amount of evaporation
from water, ice, or snow, under the varying exposures to which, in actual
nature, they are constantly subjected. If, then, we are so ignorant of all these
impossible; and in all cabinet experiments on the subject, the conditions of
the surface observed are so different from those which occur in nature, that
we cannot safely reason from one case to the other. In nature, the inclination
and exposure of the ground, the degree of freedom or obstruction of the
flow of water over the surface, the composition and density of the soil, the
presence or absence of perforations by worms and small burrowing
quadrupeds—upon which the permeability of the ground by water and its
power of absorbing and retaining or transmitting moisture depend—its
temperature, the dryness or saturation of the subsoil, vary at comparatively
short distances; and though the precipitation upon very small geographical
basins and the superficial flow from them may be estimated with an
approach to precision, yet even here we have no present means of knowing
how much of the water absorbed by the earth is restored to the atmosphere
by evaporation, and how much carried off by infiltration or other modes of
underground discharge. When, therefore, we attempt to use the phenomena
observed on a few square or cubic yards of earth, as a basis of reasoning
upon the meteorology of a province, it is evident that our data must be
insufficient to warrant positive general conclusions. In discussing the
climatology of whole countries, or even of comparatively small local
divisions, we may safely say that none can tell what percentage of the water
they receive from the atmosphere is evaporated; what absorbed by the
ground and conveyed off by subterranean conduits; what carried down to
the sea by superficial channels; what drawn from the earth or the air by a
given extent of forest, of short pasture vegetation, or of tall meadow-grass;
what given out again by surfaces so covered, or by bare ground of various
textures and composition, under different conditions of atmospheric
temperature, pressure, and humidity; or what is the amount of evaporation
from water, ice, or snow, under the varying exposures to which, in actual
nature, they are constantly subjected. If, then, we are so ignorant of all these
Page 61
climatic phenomena in the best-known regions inhabited by man, it is
evident that we can rely little upon theoretical deductions applied to the
former more natural state of the same regions—less still to such as are
adopted with respect to distant, strange, and primitive countries.
STABILITY OF NATURE.
Nature, left undisturbed, so fashions her territory as to give it almost
unchanging permanence of form, outline, and proportion, except when
shattered by geologic convulsions; and in these comparatively rare cases of
derangement, she sets herself at once to repair the superficial damage, and
to restore, as nearly as practicable, the former aspect of her dominion. In
new countries, the natural inclination of the ground, the self-formed slopes
and levels, are generally such as best secure the stability of the soil. They
have been graded and lowered or elevated by frost and chemical forces and
gravitation and the flow of water and vegetable deposit and the action of the
winds, until, by a general compensation of conflicting forces, a condition of
equilibrium has been readied which, without the action of main, would
remain, with little fluctuation, for countless ages. We need not go far back
to reach a period when, in all that portion of the North American continent
which has been occupied by British colonization, the geographical elements
very nearly balanced and compensated each other. At the commencement of
the seventeenth century, the soil, with insignificant exceptions, was covered
with forests; [Footnote: I do not here speak of the vast prairie region of the
Mississippi valley, which cannot properly said ever to have been a field of
British colonization; but of the original colonies, and their dependencies in
the territory of the present United States, and in Canada. It is, however,
equally true of the Western prairies as of the Eastern forest land, that they
had arrived at a state of equilibrium, though under very different
conditions.] and whenever the Indian, in consequence of war or the
evident that we can rely little upon theoretical deductions applied to the
former more natural state of the same regions—less still to such as are
adopted with respect to distant, strange, and primitive countries.
STABILITY OF NATURE.
Nature, left undisturbed, so fashions her territory as to give it almost
unchanging permanence of form, outline, and proportion, except when
shattered by geologic convulsions; and in these comparatively rare cases of
derangement, she sets herself at once to repair the superficial damage, and
to restore, as nearly as practicable, the former aspect of her dominion. In
new countries, the natural inclination of the ground, the self-formed slopes
and levels, are generally such as best secure the stability of the soil. They
have been graded and lowered or elevated by frost and chemical forces and
gravitation and the flow of water and vegetable deposit and the action of the
winds, until, by a general compensation of conflicting forces, a condition of
equilibrium has been readied which, without the action of main, would
remain, with little fluctuation, for countless ages. We need not go far back
to reach a period when, in all that portion of the North American continent
which has been occupied by British colonization, the geographical elements
very nearly balanced and compensated each other. At the commencement of
the seventeenth century, the soil, with insignificant exceptions, was covered
with forests; [Footnote: I do not here speak of the vast prairie region of the
Mississippi valley, which cannot properly said ever to have been a field of
British colonization; but of the original colonies, and their dependencies in
the territory of the present United States, and in Canada. It is, however,
equally true of the Western prairies as of the Eastern forest land, that they
had arrived at a state of equilibrium, though under very different
conditions.] and whenever the Indian, in consequence of war or the
Page 62
exhaustion of the beasts of the chase, abandoned the narrow fields he had
planted and the woods he had burned over, they speedily returned, by a
succession of herbaceous, arborescent, and arboreal growths, to their
original state. Even a single generation sufficed to restore them almost to
their primitive luxuriance of forest vegetation. [Footnote: The great fire of
Miramichi in 1825, probably the most extensive and terrific conflagration
recorded in authentic history, spread its ravages over nearly six thousand
square miles, chiefly of woodland, and was of such intensity that it seemed
to consume the very soil itself. But so great are the recuperative powers of
nature, that, in twenty-five years, the ground was thickly covered again with
tree of fair dimensions, except where cultivation and pasturage kept down
the forest growth.]
The unbroken forests had attained to their maximum density and strength
of growth, and, as the older trees decayed and fell, they were succeeded by
new shoots or seedlings, so that from century to century no perceptible
change seems to have occurred in the wood, except the slow, spontaneous
succession of crops. This succession involved no interruption of growth,
and but little break in the "boundless contiguity of shade;" for, in the
husbandry of nature, there are no fallows. Trees fall singly, not by square
roods, and the tall pine is hardly prostrate, before the light and heat,
admitted to the ground by the removal of the dense crown of foliage which
had shut them out, stimulate the germination of the seeds of broad-leaved
trees that had lain, waiting this kindly influence, perhaps for centuries.
FORMATION OF BOGS.
Two natural causes, destructive in character, were, indeed, in operation in
the primitive American forests, though, in the Northern colonies, at least,
there were sufficient compensations; for we do not discover that any
planted and the woods he had burned over, they speedily returned, by a
succession of herbaceous, arborescent, and arboreal growths, to their
original state. Even a single generation sufficed to restore them almost to
their primitive luxuriance of forest vegetation. [Footnote: The great fire of
Miramichi in 1825, probably the most extensive and terrific conflagration
recorded in authentic history, spread its ravages over nearly six thousand
square miles, chiefly of woodland, and was of such intensity that it seemed
to consume the very soil itself. But so great are the recuperative powers of
nature, that, in twenty-five years, the ground was thickly covered again with
tree of fair dimensions, except where cultivation and pasturage kept down
the forest growth.]
The unbroken forests had attained to their maximum density and strength
of growth, and, as the older trees decayed and fell, they were succeeded by
new shoots or seedlings, so that from century to century no perceptible
change seems to have occurred in the wood, except the slow, spontaneous
succession of crops. This succession involved no interruption of growth,
and but little break in the "boundless contiguity of shade;" for, in the
husbandry of nature, there are no fallows. Trees fall singly, not by square
roods, and the tall pine is hardly prostrate, before the light and heat,
admitted to the ground by the removal of the dense crown of foliage which
had shut them out, stimulate the germination of the seeds of broad-leaved
trees that had lain, waiting this kindly influence, perhaps for centuries.
FORMATION OF BOGS.
Two natural causes, destructive in character, were, indeed, in operation in
the primitive American forests, though, in the Northern colonies, at least,
there were sufficient compensations; for we do not discover that any
Page 63
considerable permanent change was produced by them. I refer to the action
of beavers and of fallen trees in producing bogs, [Footnote: The English
nomenclature of this geographical feature does not seem well settled. We
have bog, swamp, marsh, morass, moor, fen, turf-moss, peat-moss,
quagmire, all of which, though sometimes more or less accurately
discriminated, are often used interchangeably, or are perhaps employed,
each exclusively, in a particular district. In Sweden, where, especially in the
Lappish provinces, this terr-aqueous formation is very extensive and
important, the names of its different kinds are more specific in their
application. The general designation of all soils permanently pervaded with
water is Karr. The elder Laestadius divides the Karr into two genera: Myror
(sing. myra), and Mossar (sing. mosse). "The former," he observes, "are
grass-grown, and overflowed with water through almost the whole summer;
the latter are covered with mosses and always moist, but very seldom
overflowed." He enumerates the following species of Myra, the character of
which will perhaps be sufficiently understood by the Latin terms into which
he translates the vernacular names, for the benefit of strangers not
altogether familiar with the language and the subject: 1. Homyror, paludes
graminosae. 2. Dy, paludes profundae. 3. Flarkmyror, or proper karr,
paludes limosae. 4. Fjalimyror, paludes uliginosae. 5. Tufmyror, paludes
caespitosae. 6. Rismyror, paludes virgatae. 7. Starrangar, prata irrigata, with
their subdivisions, dry starrungar or risangar, wet starrangar and
frakengropar. 8. Polar, lacunae. 9. Golar, fossae inundatae. The Mossar,
paludes turfosae, which are of great extent, have but two species: 1.
Torfmossar, called also Mossmyror and Snottermyror, and, 2. Bjornmossar.
The accumulations of stagnant or stagnating water originating in bogs are
distinguished into Trask, stagna, and Tjernar or Tjarnar (sing. Tjern or
Tjarn), stagnatiles. Trask are pools fed by bogs, or water emanating from
them, and their bottoms are slimy; Tjernar are small Trask situated within
of beavers and of fallen trees in producing bogs, [Footnote: The English
nomenclature of this geographical feature does not seem well settled. We
have bog, swamp, marsh, morass, moor, fen, turf-moss, peat-moss,
quagmire, all of which, though sometimes more or less accurately
discriminated, are often used interchangeably, or are perhaps employed,
each exclusively, in a particular district. In Sweden, where, especially in the
Lappish provinces, this terr-aqueous formation is very extensive and
important, the names of its different kinds are more specific in their
application. The general designation of all soils permanently pervaded with
water is Karr. The elder Laestadius divides the Karr into two genera: Myror
(sing. myra), and Mossar (sing. mosse). "The former," he observes, "are
grass-grown, and overflowed with water through almost the whole summer;
the latter are covered with mosses and always moist, but very seldom
overflowed." He enumerates the following species of Myra, the character of
which will perhaps be sufficiently understood by the Latin terms into which
he translates the vernacular names, for the benefit of strangers not
altogether familiar with the language and the subject: 1. Homyror, paludes
graminosae. 2. Dy, paludes profundae. 3. Flarkmyror, or proper karr,
paludes limosae. 4. Fjalimyror, paludes uliginosae. 5. Tufmyror, paludes
caespitosae. 6. Rismyror, paludes virgatae. 7. Starrangar, prata irrigata, with
their subdivisions, dry starrungar or risangar, wet starrangar and
frakengropar. 8. Polar, lacunae. 9. Golar, fossae inundatae. The Mossar,
paludes turfosae, which are of great extent, have but two species: 1.
Torfmossar, called also Mossmyror and Snottermyror, and, 2. Bjornmossar.
The accumulations of stagnant or stagnating water originating in bogs are
distinguished into Trask, stagna, and Tjernar or Tjarnar (sing. Tjern or
Tjarn), stagnatiles. Trask are pools fed by bogs, or water emanating from
them, and their bottoms are slimy; Tjernar are small Trask situated within
Page 64
the limits of Mossar.—L.L. Laestadius, om Mojligheten af Uppodlingar i
Lappmarken, pp. 23, 24.
Although the quantity of bog land in New England is less than in many
other regions of equal area, yet there is a considerable extent of this
formation in some of the Northeastern States. Dana (Manual of Geology, p.
614) states that the quantity of peat in Massachusetts is estimated at
120,000,000 cords, or nearly 569,000,000 cubic yards, but he does not give
either the area or the depth of the deposits. In any event, however, bogs
cover but a small percentage of the territory in any of the Northern States,
while it is said that one tenth of the whole surface of Ireland is composed of
bogs, and there are still extensive tracts of undrained marsh in England. The
amount of this formation in Great Britain is estimated at 6,000,000 acres,
with an average depth of twelve feet, which would yield 21,600,000 tons of
air-dried peat.—Asbjornsen, Tore og Torodrift, Christiania, 1868, p. 6. Peat
beds have sometimes a thickness of ten or twelve yards, or even more. A
depth of ten yards would give 48,000 cubic yards to the acre. The greatest
quantity of firewood yielded by the forests of New England to the acre is
100 cords solid measure, or 474 cubic yards; but this comprises only the
trunks and larger branches. If we add the small branches and twigs, it is
possible that 600 cubic yards might, in some cases, be cut on an acre. This
is only one eightieth part of the quantity of peat sometimes found on the
same area. It is true that a yard of peat and a yard of wood are not the
equivalents of each other, but the fuel on an acre of deep peat is worth much
more than that on an acre of the best woodland. Besides this, wood is
perishable, and the quantity of an acre cannot be increased beyond the
amount just stated; peat is indestructible, and the beds are always growing.
See post, Chap. IV. Cold favors the conversion of aquatic vegetables into
peat. Asbjornsen says some of the best peat he has met with is from a bog
which is frozen for forty weeks in the year.
Lappmarken, pp. 23, 24.
Although the quantity of bog land in New England is less than in many
other regions of equal area, yet there is a considerable extent of this
formation in some of the Northeastern States. Dana (Manual of Geology, p.
614) states that the quantity of peat in Massachusetts is estimated at
120,000,000 cords, or nearly 569,000,000 cubic yards, but he does not give
either the area or the depth of the deposits. In any event, however, bogs
cover but a small percentage of the territory in any of the Northern States,
while it is said that one tenth of the whole surface of Ireland is composed of
bogs, and there are still extensive tracts of undrained marsh in England. The
amount of this formation in Great Britain is estimated at 6,000,000 acres,
with an average depth of twelve feet, which would yield 21,600,000 tons of
air-dried peat.—Asbjornsen, Tore og Torodrift, Christiania, 1868, p. 6. Peat
beds have sometimes a thickness of ten or twelve yards, or even more. A
depth of ten yards would give 48,000 cubic yards to the acre. The greatest
quantity of firewood yielded by the forests of New England to the acre is
100 cords solid measure, or 474 cubic yards; but this comprises only the
trunks and larger branches. If we add the small branches and twigs, it is
possible that 600 cubic yards might, in some cases, be cut on an acre. This
is only one eightieth part of the quantity of peat sometimes found on the
same area. It is true that a yard of peat and a yard of wood are not the
equivalents of each other, but the fuel on an acre of deep peat is worth much
more than that on an acre of the best woodland. Besides this, wood is
perishable, and the quantity of an acre cannot be increased beyond the
amount just stated; peat is indestructible, and the beds are always growing.
See post, Chap. IV. Cold favors the conversion of aquatic vegetables into
peat. Asbjornsen says some of the best peat he has met with is from a bog
which is frozen for forty weeks in the year.
Page 65
The Greeks and Romans were not acquainted with the employment of
peat as fuel, but it appears from a curious passage which I have already
cited from Pliny, N. H., book xvi., chap. 1, that the inhabitants of the North
Sea coast used what is called kneaded turf in his time. This is the finer and
more thoroughly decomposed matter lying at the bottom of the peat,
kneaded by the hands, formed into small blocks and dried. It is still
prepared in precisely the same way by the poorer inhabitants of those
shores.
But though the Low German tribes, including probably the Anglo-
Saxons, have used peat as fuel from time immemorial, it appears not to
have been known to the High Germans until a recent period. At least, I can
find neither in Old nor in Middle High German lexicons and glossaries any
word signifying peat. Zurb indeed is found in Graff as an Old High German
word, but only in the sense of grass-turf, or greensward. Peat bogs of vast
extent occur in many High German localities, but the former abundance of
wood in the same regions rendered the use of peat unnecessary.] and of
smaller animals, insects, and birds, in destroying the woods. [Footnote: See
Chapter II., post.]
Bogs generally originate in the checking of watercourses by the falling of
timber or of earth and rocks, or by artificial obstructions across their
channels. If the impediment is sufficient to retain a permanent accumulation
of water behind it, the trees whose roots are overflowed soon perish, and
then by their fall increase the obstruction, and, of course, occasion a still
wider spread of the stagnating stream. This process goes on until the water
finds a new outlet, at a higher level, not liable to similar interruption. The
fallen trees not completely covered by water are soon overgrown with
mosses; aquatic and semiaquatic plants propagate themselves, and spread
until they more or less completely fill up the space occupied by the water,
and the surface is gradually converted from a pond to a quaking morass.
peat as fuel, but it appears from a curious passage which I have already
cited from Pliny, N. H., book xvi., chap. 1, that the inhabitants of the North
Sea coast used what is called kneaded turf in his time. This is the finer and
more thoroughly decomposed matter lying at the bottom of the peat,
kneaded by the hands, formed into small blocks and dried. It is still
prepared in precisely the same way by the poorer inhabitants of those
shores.
But though the Low German tribes, including probably the Anglo-
Saxons, have used peat as fuel from time immemorial, it appears not to
have been known to the High Germans until a recent period. At least, I can
find neither in Old nor in Middle High German lexicons and glossaries any
word signifying peat. Zurb indeed is found in Graff as an Old High German
word, but only in the sense of grass-turf, or greensward. Peat bogs of vast
extent occur in many High German localities, but the former abundance of
wood in the same regions rendered the use of peat unnecessary.] and of
smaller animals, insects, and birds, in destroying the woods. [Footnote: See
Chapter II., post.]
Bogs generally originate in the checking of watercourses by the falling of
timber or of earth and rocks, or by artificial obstructions across their
channels. If the impediment is sufficient to retain a permanent accumulation
of water behind it, the trees whose roots are overflowed soon perish, and
then by their fall increase the obstruction, and, of course, occasion a still
wider spread of the stagnating stream. This process goes on until the water
finds a new outlet, at a higher level, not liable to similar interruption. The
fallen trees not completely covered by water are soon overgrown with
mosses; aquatic and semiaquatic plants propagate themselves, and spread
until they more or less completely fill up the space occupied by the water,
and the surface is gradually converted from a pond to a quaking morass.
Page 66
The morass is slowly solidified by vegetable production and deposit, then
very often restored to the forest condition by the growth of black ashes,
cedars, or, in southern latitudes, cypresses, and other trees suited to such a
soil, and thus the interrupted harmony of nature is at last reestablished.
[Footnote: "Aquatic plants have a utility in raising the level of marshy
grounds, which renders them very valuable, and may well be called a
geological function. The engineer drains ponds at a great expense by
lowering the surface of the water; nature attains the same end, gratuitously,
by raising the level of the soil without depressing that of the water; but she
proceeds more slowly. There are, in the Landes, marshes where this natural
filling has a thickness of four metres, and some of them, at first lower than
the sea, have been thus raised and drained so as to grow summer crops,
such, for example, as maize."—Boitel, Mise en valeur des Terres pauvres,
p. 227.
The bogs of Denmark—the examination of which by Steenstrap and
Vaupell has presented such curious results with respect to the natural
succession of forest trees—appear to have gone through this gradual
process of drying, and the birch, which grow freely in very wet soils, has
contributed very effectually by its annual deposits to raise the surface above
the water level, and thus to prepare the ground for the oak.—Vaupell,
Bogens Indvandring, pp. 39, 40.
The growth of the peat not unfrequently raises the surface of bogs
considerably above the level of the surrounding country, and they
sometimes burst and overflow lower grounds with a torrent of mud and
water as destructive as a current of lava.]
In countries somewhat further advanced in civilization than those
occupied by the North American Indians, as in mediaeval Ireland, the
formation of bogs may be commenced by the neglect of man to remove,
very often restored to the forest condition by the growth of black ashes,
cedars, or, in southern latitudes, cypresses, and other trees suited to such a
soil, and thus the interrupted harmony of nature is at last reestablished.
[Footnote: "Aquatic plants have a utility in raising the level of marshy
grounds, which renders them very valuable, and may well be called a
geological function. The engineer drains ponds at a great expense by
lowering the surface of the water; nature attains the same end, gratuitously,
by raising the level of the soil without depressing that of the water; but she
proceeds more slowly. There are, in the Landes, marshes where this natural
filling has a thickness of four metres, and some of them, at first lower than
the sea, have been thus raised and drained so as to grow summer crops,
such, for example, as maize."—Boitel, Mise en valeur des Terres pauvres,
p. 227.
The bogs of Denmark—the examination of which by Steenstrap and
Vaupell has presented such curious results with respect to the natural
succession of forest trees—appear to have gone through this gradual
process of drying, and the birch, which grow freely in very wet soils, has
contributed very effectually by its annual deposits to raise the surface above
the water level, and thus to prepare the ground for the oak.—Vaupell,
Bogens Indvandring, pp. 39, 40.
The growth of the peat not unfrequently raises the surface of bogs
considerably above the level of the surrounding country, and they
sometimes burst and overflow lower grounds with a torrent of mud and
water as destructive as a current of lava.]
In countries somewhat further advanced in civilization than those
occupied by the North American Indians, as in mediaeval Ireland, the
formation of bogs may be commenced by the neglect of man to remove,
Page 67
from the natural channels of superficial drainage, the tops and branches of
trees felled for the various purposes to which wood is applicable in his rude
industry; and, when the flow of the water is thus checked, nature goes on
with the processes I have already described. In such half-civilized regions,
too, windfalls are more frequent than in those where the forest is unbroken,
because, when openings have been made in it for agricultural or other
purposes, the entrance thus afforded to the wind occasions the sudden
overthrow of hundreds of trees which might otherwise have stood for
generations and have fallen to the ground, only one by one, as natural decay
brought them down. [Footnote: Careful examination of the peat mosses in
North Sjaelland—which are so abundant in fossil wood that, within thirty
years, they have yielded above a million of trees—shows that the trees have
generally fallen from age and not from wind. They are found in depressions
on the declivities of which they grew, and they lie with the top lowest,
always falling towards the bottom of the valley.—Vaupell, Bogens
Indvandring i de Danske Skove, pp. 10,14.] Besides this, the flocks bred by
man in the pastoral state keep down the incipient growth of trees on the
half-dried bogs, and prevent them from recovering their primitive condition.
Young trees in the native forest are sometimes girdled and killed by the
smaller rodent quadrupeds, and their growth is checked by birds which feed
on the terminal bud; but these animals, as we shall see, are generally found
on the skirts of the wood only, not in its deeper recesses, and hence the
mischief they do is not extensive.
In fine, in countries untrodden by man, the proportions and relative
positions of land and water, the atmospheric precipitation and evaporation,
the thermometric mean, and the distribution of vegetable and animal life,
are maintained by natural compensations, in a state of approximate
equilibrium, and are subject to appreciable change only from geological
influences so slow in their operation that the geographical conditions may
be regarded as substantially constant and immutable.
trees felled for the various purposes to which wood is applicable in his rude
industry; and, when the flow of the water is thus checked, nature goes on
with the processes I have already described. In such half-civilized regions,
too, windfalls are more frequent than in those where the forest is unbroken,
because, when openings have been made in it for agricultural or other
purposes, the entrance thus afforded to the wind occasions the sudden
overthrow of hundreds of trees which might otherwise have stood for
generations and have fallen to the ground, only one by one, as natural decay
brought them down. [Footnote: Careful examination of the peat mosses in
North Sjaelland—which are so abundant in fossil wood that, within thirty
years, they have yielded above a million of trees—shows that the trees have
generally fallen from age and not from wind. They are found in depressions
on the declivities of which they grew, and they lie with the top lowest,
always falling towards the bottom of the valley.—Vaupell, Bogens
Indvandring i de Danske Skove, pp. 10,14.] Besides this, the flocks bred by
man in the pastoral state keep down the incipient growth of trees on the
half-dried bogs, and prevent them from recovering their primitive condition.
Young trees in the native forest are sometimes girdled and killed by the
smaller rodent quadrupeds, and their growth is checked by birds which feed
on the terminal bud; but these animals, as we shall see, are generally found
on the skirts of the wood only, not in its deeper recesses, and hence the
mischief they do is not extensive.
In fine, in countries untrodden by man, the proportions and relative
positions of land and water, the atmospheric precipitation and evaporation,
the thermometric mean, and the distribution of vegetable and animal life,
are maintained by natural compensations, in a state of approximate
equilibrium, and are subject to appreciable change only from geological
influences so slow in their operation that the geographical conditions may
be regarded as substantially constant and immutable.
Page 68
NATURAL CONDITIONS FAVORABLE TO GEOGRAPHICAL
CHANGE.
There are, nevertheless, certain climatic conditions and certain forms and
formations of terrestrial surface, which tend respectively to impede and to
facilitate the physical degradation both of new countries and of old. If the
precipitation, whether great or small in amount, be equally distributed
through the seasons, so that there are neither torrential rains nor parching
droughts, and if, further, the general inclination of ground be moderate, so
that the superficial waters are carried off without destructive rapidity of
flow, and without sudden accumulation in the channels of natural drainage,
there is little danger of the degradation of the soil in consequence of the
removal of forest or other vegetable covering, and the natural face of the
earth may be considered as virtually permanent. These conditions are well
exemplified in Ireland, in a great part of England, in extensive districts in
Germany and France, and, fortunately, in an immense proportion of the
valley of the Mississippi and the basin of the great American lakes, as well
as in many parts of the continents of South America and of Africa, and it is
partly, though by no means entirely, owing to topographical and climatic
causes that the blight, which has smitten the fairest and most fertile
provinces of Imperial Rome, has spared Britannia, Germania, Pannonia, and
Moesia, the comparatively inhospitable homes of barbarous races, who, in
the days of the Caesars, were too little advanced in civilized life to possess
either the power or the will to wage that war against the order of nature
which seems, hitherto, an almost inseparable condition precedent of high
social culture, and of great progress in fine and mechanical art. Destructive
changes are most frequent in countries of irregular and mountainous
surface, and in climates where the precipitation is confined chiefly to a
single season, and where, of course, the year is divided into a wet and a dry
period, as is the case throughout a great part of the Ottoman empire, and,
indeed, in a large proportion of the whole Mediterranean basin. In
CHANGE.
There are, nevertheless, certain climatic conditions and certain forms and
formations of terrestrial surface, which tend respectively to impede and to
facilitate the physical degradation both of new countries and of old. If the
precipitation, whether great or small in amount, be equally distributed
through the seasons, so that there are neither torrential rains nor parching
droughts, and if, further, the general inclination of ground be moderate, so
that the superficial waters are carried off without destructive rapidity of
flow, and without sudden accumulation in the channels of natural drainage,
there is little danger of the degradation of the soil in consequence of the
removal of forest or other vegetable covering, and the natural face of the
earth may be considered as virtually permanent. These conditions are well
exemplified in Ireland, in a great part of England, in extensive districts in
Germany and France, and, fortunately, in an immense proportion of the
valley of the Mississippi and the basin of the great American lakes, as well
as in many parts of the continents of South America and of Africa, and it is
partly, though by no means entirely, owing to topographical and climatic
causes that the blight, which has smitten the fairest and most fertile
provinces of Imperial Rome, has spared Britannia, Germania, Pannonia, and
Moesia, the comparatively inhospitable homes of barbarous races, who, in
the days of the Caesars, were too little advanced in civilized life to possess
either the power or the will to wage that war against the order of nature
which seems, hitherto, an almost inseparable condition precedent of high
social culture, and of great progress in fine and mechanical art. Destructive
changes are most frequent in countries of irregular and mountainous
surface, and in climates where the precipitation is confined chiefly to a
single season, and where, of course, the year is divided into a wet and a dry
period, as is the case throughout a great part of the Ottoman empire, and,
indeed, in a large proportion of the whole Mediterranean basin. In
Page 69
mountainous countries various causes combine to expose the soil to
constant dangers. The rain and snow usually fall in greater quantity, and
with much inequality of distribution; the snow on the summits accumulates
for many months in succession, and then is not unfrequently almost wholly
dissolved in a single thaw, so that the entire precipitation of months is in a
few hours hurried down the flanks of the mountains, and through the
ravines that furrow them; the natural inclination of the surface promotes the
swiftness of the gathering currents of diluvial rain and of melting snow,
which soon acquire an almost irresistible force and power of removal and
transportation; the soil itself is less compact and tenacious than that of the
plains, and if the sheltering forest has been destroyed, it is contined by few
of the threads and ligaments by which nature had bound it together, and
attached it to the rocky groundwork. Hence every considerable shower lays
bare its roods of rock, and the torrents sent down by the thaws of spring,
and by occasional heavy discharges of the summer and autumnal rains, are
seas of mud and rolling stones that sometimes lay waste and bury beneath
them acres, and even miles, of pasture and field and vineyard. [Footnote:
The character of geological formation is an element of very great
importance in determining the amount of erosion produced by running
water, and, of course, in measuring the consequences of clearing off the
forests. The soil of the French Alps yields very readily to the force of
currents, and the declivities of the northern Apennines, as well as of many
minor mountain ridges in Tuscany and other parts or Italy, are covered with
earth which becomes itself almost a fluid when saturated with water. Hence
the erosion of such surfaces is vastly greater than on many other mountains
of equal steepness of inclination. The traveller who passes over the route
between Bologna and Florence, and the Perugia and the Siena roads from
the latter city to Rome, will have many opportunities of observing such
localities.]
constant dangers. The rain and snow usually fall in greater quantity, and
with much inequality of distribution; the snow on the summits accumulates
for many months in succession, and then is not unfrequently almost wholly
dissolved in a single thaw, so that the entire precipitation of months is in a
few hours hurried down the flanks of the mountains, and through the
ravines that furrow them; the natural inclination of the surface promotes the
swiftness of the gathering currents of diluvial rain and of melting snow,
which soon acquire an almost irresistible force and power of removal and
transportation; the soil itself is less compact and tenacious than that of the
plains, and if the sheltering forest has been destroyed, it is contined by few
of the threads and ligaments by which nature had bound it together, and
attached it to the rocky groundwork. Hence every considerable shower lays
bare its roods of rock, and the torrents sent down by the thaws of spring,
and by occasional heavy discharges of the summer and autumnal rains, are
seas of mud and rolling stones that sometimes lay waste and bury beneath
them acres, and even miles, of pasture and field and vineyard. [Footnote:
The character of geological formation is an element of very great
importance in determining the amount of erosion produced by running
water, and, of course, in measuring the consequences of clearing off the
forests. The soil of the French Alps yields very readily to the force of
currents, and the declivities of the northern Apennines, as well as of many
minor mountain ridges in Tuscany and other parts or Italy, are covered with
earth which becomes itself almost a fluid when saturated with water. Hence
the erosion of such surfaces is vastly greater than on many other mountains
of equal steepness of inclination. The traveller who passes over the route
between Bologna and Florence, and the Perugia and the Siena roads from
the latter city to Rome, will have many opportunities of observing such
localities.]
Page 70
Destructiveness of Man.
Man has too long forgotten that the earth was given to him for usufruct
alone, not for consumption, still less for profligate waste. Nature has
provided against the absolute destruction of any of her elementary matter,
the raw material of her works; the thunderbolt and the tornado, the most
convulsive throes of even the volcano and the earthquake, being only
phenomena of decomposition and recomposition. But she has left it within
the power of man irreparably to derange the combinations of inorganic
matter and of organic life, which through the night of aeons she had been
proportioning and balancing, to prepare the earth for his habitation, when in
the fulness of time his Creator should call him forth to enter into its
possession.
Apart from the hostile influence of man, the organic and the inorganic
world are, as I have remarked, bound together by such mutual relations and
adaptations as secure, if not the absolute permanence and equilibrium of
both, a long continuance of the established conditions of each at any given
time and place, or at least, a very slow and gradual succession of changes in
those conditions. But man is everywhere a disturbing agent. Wherever he
plants his foot, the harmonies of nature are turned to discords. The
proportions and accommodations which insured the stability of existing
arrangements are overthrown. Indigenous vegetable and animal species are
extirpated, and supplanted by others of foreign origin, spontaneous
production is forbidden or restricted, and the face of the earth is either laid
bare or covered with a new and reluctant growth of vegetable forms, and
with alien tribes of animal life. These intentional changes and substitutions
constitute, indeed, great revolutions; but vast as is their magnitude and
importance, they are, as we shall see, insignificant in comparison with the
contingent and unsought results which have flowed from them.
Man has too long forgotten that the earth was given to him for usufruct
alone, not for consumption, still less for profligate waste. Nature has
provided against the absolute destruction of any of her elementary matter,
the raw material of her works; the thunderbolt and the tornado, the most
convulsive throes of even the volcano and the earthquake, being only
phenomena of decomposition and recomposition. But she has left it within
the power of man irreparably to derange the combinations of inorganic
matter and of organic life, which through the night of aeons she had been
proportioning and balancing, to prepare the earth for his habitation, when in
the fulness of time his Creator should call him forth to enter into its
possession.
Apart from the hostile influence of man, the organic and the inorganic
world are, as I have remarked, bound together by such mutual relations and
adaptations as secure, if not the absolute permanence and equilibrium of
both, a long continuance of the established conditions of each at any given
time and place, or at least, a very slow and gradual succession of changes in
those conditions. But man is everywhere a disturbing agent. Wherever he
plants his foot, the harmonies of nature are turned to discords. The
proportions and accommodations which insured the stability of existing
arrangements are overthrown. Indigenous vegetable and animal species are
extirpated, and supplanted by others of foreign origin, spontaneous
production is forbidden or restricted, and the face of the earth is either laid
bare or covered with a new and reluctant growth of vegetable forms, and
with alien tribes of animal life. These intentional changes and substitutions
constitute, indeed, great revolutions; but vast as is their magnitude and
importance, they are, as we shall see, insignificant in comparison with the
contingent and unsought results which have flowed from them.
Page 71
The fact that, of all organic beings, man alone is to be regarded as
essentially a destructive power, and that he wields energies to resist which
Nature—that nature whom all material life and all inorganic substance obey
—is wholly impotent, tends to prove that, though living in physical nature,
he is not of her, that he is of more exalted parentage, and belongs to a
higher order of existences, than those which are born of her womb and live
in blind submission to her dictates.
There are, indeed, brute destroyers, beasts and birds and insects of prey
—all animal life feeds upon, and, of course, destroys other life,—but this
destruction is balanced by compensations. It is, in fact, the very means by
which the existence of one tribe of animals or of vegetables is secured
against being smothered by the encroachments of another; and the
reproductive powers of species, which serve as the food of others, are
always proportioned to the demand they are destined to supply. Man
pursues his victims with reckless destructiveness; and, while the sacrifice of
life by the lower animals is limited by the cravings of appetite, he
unsparingly persecutes, even to extirpation, thousands of organic forms
which he cannot consume. [Footnote: The terrible destructiveness of man is
remarkably exemplified in the chase of large mammalia and birds for single
products, attended with the entire waste of enormous quantities of flesh, and
of other parts of the animal which are capable of valuable uses. The wild
cattle of South America are slaughtered by millions for their hides and
hairs; the buffalo of North America for his skin or his tongue; the elephant,
the walrus, and the narwhal for their tusks; the cetacen, and some other
marine animals, for their whalebone and oil; the ostrich and other large
birds, for their plumage. Within a few years, sheep have been killed in New
England, by whole flocks, for their pelts and suet alone, the flesh being
thrown away; and it is even said that the bodies of the same quadrupeds
have been used in Australia as fuel for limekilns. What a vast amount of
human nutriment, of bone, and of other animal products valuable in the arts,
essentially a destructive power, and that he wields energies to resist which
Nature—that nature whom all material life and all inorganic substance obey
—is wholly impotent, tends to prove that, though living in physical nature,
he is not of her, that he is of more exalted parentage, and belongs to a
higher order of existences, than those which are born of her womb and live
in blind submission to her dictates.
There are, indeed, brute destroyers, beasts and birds and insects of prey
—all animal life feeds upon, and, of course, destroys other life,—but this
destruction is balanced by compensations. It is, in fact, the very means by
which the existence of one tribe of animals or of vegetables is secured
against being smothered by the encroachments of another; and the
reproductive powers of species, which serve as the food of others, are
always proportioned to the demand they are destined to supply. Man
pursues his victims with reckless destructiveness; and, while the sacrifice of
life by the lower animals is limited by the cravings of appetite, he
unsparingly persecutes, even to extirpation, thousands of organic forms
which he cannot consume. [Footnote: The terrible destructiveness of man is
remarkably exemplified in the chase of large mammalia and birds for single
products, attended with the entire waste of enormous quantities of flesh, and
of other parts of the animal which are capable of valuable uses. The wild
cattle of South America are slaughtered by millions for their hides and
hairs; the buffalo of North America for his skin or his tongue; the elephant,
the walrus, and the narwhal for their tusks; the cetacen, and some other
marine animals, for their whalebone and oil; the ostrich and other large
birds, for their plumage. Within a few years, sheep have been killed in New
England, by whole flocks, for their pelts and suet alone, the flesh being
thrown away; and it is even said that the bodies of the same quadrupeds
have been used in Australia as fuel for limekilns. What a vast amount of
human nutriment, of bone, and of other animal products valuable in the arts,
Page 72
is thus recklessly squandered! In nearly all these cases, the part which
constitutes the motive for this wholesale destruction, and is alone saved, is
essentially of insignificant value as compared with what is thrown away.
The horns and hide of an ox are not economically worth a tenth part as
much as the entire carcass. During the present year, large quantities of
Indian corn have been used as domestic fuel, and even for burning lime, in
Iowa and other Western States. Corn at from fifteen to eighteen cents per
bushel is found cheaper than wood at from five to seven dollars per cord, or
coal at six or seven dollars per ton.-Rep. Agric. Dept., Nov. and Dec., 1872,
p. 487.
One of the greatest benefits to be expected from the improvement
civilization is, that increased facilities of communication will render it
possible to transport to places of consumption much valuable material that
is now wasted because the price at the nearest market will not pay freight.
The cattle slaughtered in South America for their hides would feed millions
of the starving population of the Old World, if their flesh could be
economically preserved and transported across the ocean. This, indeed, is
already done, but on a scale which, though absolutely considerable, is
relatively insignificant. South America sends to Europe a certain quantity of
nutriment in the form of meat extracts, Liebig's and others; and preserved
flesh from Australia is beginning to figure in the English market. We are
beginning to learn a better economy in dealing with the inorganic world.
The utilization—or, as the Germans more happily call it, the Verwerthung,
the BEWORTHING—of waste from metallurgical, chemical, and
manufacturing establishments, is among the most important results of the
application of science to industrial purposes. The incidental products from
the laboratories of manufacturing chemists often become more valuable
than those for the preparation of which they were erected. The slags front
silver refineries, and even from smelting houses of the coarser metals, have
not unfrequently yielded to a second operator a better return than the first
constitutes the motive for this wholesale destruction, and is alone saved, is
essentially of insignificant value as compared with what is thrown away.
The horns and hide of an ox are not economically worth a tenth part as
much as the entire carcass. During the present year, large quantities of
Indian corn have been used as domestic fuel, and even for burning lime, in
Iowa and other Western States. Corn at from fifteen to eighteen cents per
bushel is found cheaper than wood at from five to seven dollars per cord, or
coal at six or seven dollars per ton.-Rep. Agric. Dept., Nov. and Dec., 1872,
p. 487.
One of the greatest benefits to be expected from the improvement
civilization is, that increased facilities of communication will render it
possible to transport to places of consumption much valuable material that
is now wasted because the price at the nearest market will not pay freight.
The cattle slaughtered in South America for their hides would feed millions
of the starving population of the Old World, if their flesh could be
economically preserved and transported across the ocean. This, indeed, is
already done, but on a scale which, though absolutely considerable, is
relatively insignificant. South America sends to Europe a certain quantity of
nutriment in the form of meat extracts, Liebig's and others; and preserved
flesh from Australia is beginning to figure in the English market. We are
beginning to learn a better economy in dealing with the inorganic world.
The utilization—or, as the Germans more happily call it, the Verwerthung,
the BEWORTHING—of waste from metallurgical, chemical, and
manufacturing establishments, is among the most important results of the
application of science to industrial purposes. The incidental products from
the laboratories of manufacturing chemists often become more valuable
than those for the preparation of which they were erected. The slags front
silver refineries, and even from smelting houses of the coarser metals, have
not unfrequently yielded to a second operator a better return than the first
Page 73
had derived from dealing with the natural ore; and the saving of lead carried
off in the smoke of furnaces has, of itself, given a large profit on the capital
invested in the works. According to Ure's Dictionary of Arts, see vol. ii., p.
832, an English miner has constructed flues five miles in length for the
condensation of the smoke from his lead-works, and makes thereby an
annual saving of metal to the value of ten thousand pounds sterling. A few
years ago, an officer of an American mint was charged with embezzling
gold committed to him for coinage. He insisted, in his defence, that much of
the metal was volatilized and lost in refining and melting, and upon
scraping the chimneys of the melting furnaces and the roofs of the adjacent
houses, gold enough was found in the soot to account for no small part of
the deficiency.
The substitution of expensive machinery for manual labor, even in
agriculture—not to speak of older and more familiar applications—besides
being highly remunerative, has better secured the harvests, and it is
computed that the 230,000 threshing machines used in the United States in
1870 obtained five per cent. more grain from the sheaves which passed
through them than could have been secured by the use of the flail.
The cotton growing States in America produce annually nearly three
million tons of cotton seed. This, until very recently, has been thrown away
as a useless incumbrance, but it is now valued at ten or twelve dollars per
ton for the cotton fibre which adheres to it, for the oil extracted from it, and
for the feed which the refuse furnishes to cattle. The oil—which may be
described as neutral—is used very largely for mixing with other oils, many
of which bear a large proportion of it without injury to their special
properties.
There are still, however, cases of enormous waste in many mineral and
mechanical industries. Thus, while in many European countries common
off in the smoke of furnaces has, of itself, given a large profit on the capital
invested in the works. According to Ure's Dictionary of Arts, see vol. ii., p.
832, an English miner has constructed flues five miles in length for the
condensation of the smoke from his lead-works, and makes thereby an
annual saving of metal to the value of ten thousand pounds sterling. A few
years ago, an officer of an American mint was charged with embezzling
gold committed to him for coinage. He insisted, in his defence, that much of
the metal was volatilized and lost in refining and melting, and upon
scraping the chimneys of the melting furnaces and the roofs of the adjacent
houses, gold enough was found in the soot to account for no small part of
the deficiency.
The substitution of expensive machinery for manual labor, even in
agriculture—not to speak of older and more familiar applications—besides
being highly remunerative, has better secured the harvests, and it is
computed that the 230,000 threshing machines used in the United States in
1870 obtained five per cent. more grain from the sheaves which passed
through them than could have been secured by the use of the flail.
The cotton growing States in America produce annually nearly three
million tons of cotton seed. This, until very recently, has been thrown away
as a useless incumbrance, but it is now valued at ten or twelve dollars per
ton for the cotton fibre which adheres to it, for the oil extracted from it, and
for the feed which the refuse furnishes to cattle. The oil—which may be
described as neutral—is used very largely for mixing with other oils, many
of which bear a large proportion of it without injury to their special
properties.
There are still, however, cases of enormous waste in many mineral and
mechanical industries. Thus, while in many European countries common
Page 74
salt is a government monopoly, and consequently so dear that the poor do
not use as much or it as health requires, in others, as in Transylvania, where
it is quarried like stone, the large blocks only are saved, the fragments, to
the amount of millions of hundred weights, being thrown away.—Bonar,
Transylvania, p. 455, 6.
One of the most interesting and important branches of economy at the
present day is the recovery of agents such as ammonia and ethers which had
been utilized in chemical manufactures, and re-employing them indefinitely
afterwards in repeating the same process.
Among the supplemental exhibitions which will be formed in connection
with the Vienna Universal Exhibition is to be one showing what steps have
been taken since 1851 (the date of the first London Exhibition) in the
utilization of substances previously regarded as waste. On the one hand will
be shown the waste products in all the industrial processes included in the
forthcoming Exhibition; on the other hand, the useful products which have
been obtained from such wastes since 1851. This is intended to serve as an
incentive to further researches in the same important direction.]
The earth was not, in its natural condition, completely adapted to the use
of man, but only to the sustenance of wild animals and wild vegetation.
These live, multiply their kind in just proportion, and attain their perfect
measure of strength and beauty, without producing or requiring any
important change in the natural arrangements of surface, or in each other's
spontaneous tendencies, except such mutual repression of excessive
increase as may prevent the extirpation of one species by the encroachments
of another. In short, without man, lower animal and spontaneous vegetable
life would have been practically constant in type, distribution, and
proportion, and the physical geography of the earth would have remained
undisturbed for indefinite periods, and been subject to revolution only from
not use as much or it as health requires, in others, as in Transylvania, where
it is quarried like stone, the large blocks only are saved, the fragments, to
the amount of millions of hundred weights, being thrown away.—Bonar,
Transylvania, p. 455, 6.
One of the most interesting and important branches of economy at the
present day is the recovery of agents such as ammonia and ethers which had
been utilized in chemical manufactures, and re-employing them indefinitely
afterwards in repeating the same process.
Among the supplemental exhibitions which will be formed in connection
with the Vienna Universal Exhibition is to be one showing what steps have
been taken since 1851 (the date of the first London Exhibition) in the
utilization of substances previously regarded as waste. On the one hand will
be shown the waste products in all the industrial processes included in the
forthcoming Exhibition; on the other hand, the useful products which have
been obtained from such wastes since 1851. This is intended to serve as an
incentive to further researches in the same important direction.]
The earth was not, in its natural condition, completely adapted to the use
of man, but only to the sustenance of wild animals and wild vegetation.
These live, multiply their kind in just proportion, and attain their perfect
measure of strength and beauty, without producing or requiring any
important change in the natural arrangements of surface, or in each other's
spontaneous tendencies, except such mutual repression of excessive
increase as may prevent the extirpation of one species by the encroachments
of another. In short, without man, lower animal and spontaneous vegetable
life would have been practically constant in type, distribution, and
proportion, and the physical geography of the earth would have remained
undisturbed for indefinite periods, and been subject to revolution only from
Page 75
slow development, from possible, unknown cosmical causes, or from
geological action.
But man, the domestic animals that serve him, the field and garden plants
the products of which supply him with food and clothing, cannot subsist
and rise to the full development of their higher properties, unless brute and
unconscious nature be effectually combated, and, in a great degree,
vanquished by human art. Hence, a certain measure of transformation of
terrestrial surface, of suppression of natural, and stimulation of artificially
modified productivity becomes necessary. This measure man has
unfortunately exceeded. He has felled the forests whose network of fibrous
roots bound the mould to the rocky skeleton of the earth; but had he
allowed here and there a belt of woodland to reproduce itself by
spontaneous propagation, most of the mischiefs which his reckless
destruction of the natural protection of the soil has occasioned would have
been averted. He has broken up the mountain reservoirs, the percolation of
whose waters through unseen channels supplied the fountains that refreshed
his cattle and fertilized his fields; but he has neglected to maintain the
cisterns and the canals of irrigation which a wise antiquity had constructed
to neutralize the consequences of its own imprudence. While he has torn the
thin glebe which confined the light earth of extensive plains, and has
destroyed the fringe of semi-aquatic plants which skirted the coast and
checked the drifting of the sea sand, he has failed to prevent the spreading
of the dunes by clothing them with artificially propagated vegetation. He
has ruthlessly warred on all the tribes of animated nature whose spoil he
could convert to his own uses, and he has not protected the birds which prey
on the insects most destructive to his own harvests.
Purely untutored humanity, it is true, interferes comparatively little with
the arrangements of nature, [Footnote: It is an interesting and not hitherto
sufficiently noticed fact, that the domestication of the organic world, so far
geological action.
But man, the domestic animals that serve him, the field and garden plants
the products of which supply him with food and clothing, cannot subsist
and rise to the full development of their higher properties, unless brute and
unconscious nature be effectually combated, and, in a great degree,
vanquished by human art. Hence, a certain measure of transformation of
terrestrial surface, of suppression of natural, and stimulation of artificially
modified productivity becomes necessary. This measure man has
unfortunately exceeded. He has felled the forests whose network of fibrous
roots bound the mould to the rocky skeleton of the earth; but had he
allowed here and there a belt of woodland to reproduce itself by
spontaneous propagation, most of the mischiefs which his reckless
destruction of the natural protection of the soil has occasioned would have
been averted. He has broken up the mountain reservoirs, the percolation of
whose waters through unseen channels supplied the fountains that refreshed
his cattle and fertilized his fields; but he has neglected to maintain the
cisterns and the canals of irrigation which a wise antiquity had constructed
to neutralize the consequences of its own imprudence. While he has torn the
thin glebe which confined the light earth of extensive plains, and has
destroyed the fringe of semi-aquatic plants which skirted the coast and
checked the drifting of the sea sand, he has failed to prevent the spreading
of the dunes by clothing them with artificially propagated vegetation. He
has ruthlessly warred on all the tribes of animated nature whose spoil he
could convert to his own uses, and he has not protected the birds which prey
on the insects most destructive to his own harvests.
Purely untutored humanity, it is true, interferes comparatively little with
the arrangements of nature, [Footnote: It is an interesting and not hitherto
sufficiently noticed fact, that the domestication of the organic world, so far
Page 76
as it has yet been achieved, belongs, not indeed to the savage state, but to
the earliest dawn of civilization, the conquest of inorganic nature almost as
exclusively to the most advanced stages of artificial culture. Civilization has
added little to the number of vegetable or animal species grown in our fields
or bred in our folds—the cranberry and the wild grape being almost the
only plants which the Anglo-American has reclaimed out of our most native
flora and added to his harvests—while, on the contrary, the subjugation of
the inorganic forces, and the consequent extension of man's sway over, not
the annual products of the earth only, but her substance and her springs of
action, is almost entirely the work of highly refined and cultivated ages. The
employment of the elasticity of wood and of horn, as a projectile power in
the bow, is nearly universal among the rudest savages. The application of
compressed air to the same purpose, in the blowpipe, is more restricted, and
the use of the mechanical powers, the inclined plane, the wheel and axle,
and even the wedge and lever, seems almost unknown except to civilized
man. I have myself seen European peasants to whom one of the simplest
applications of this latter power was a revelation.
It is familiarly known to all who have occupied themselves with the
psychology and habits of the ruder races, and of persons with imperfectly
developed intellects in civilized life, that although these humble tribes and
individuals sacrifice, without scruple, the lives of the lower animals to the
gratification of their appetites and the supply of their other physical wants,
yet they nevertheless seem to cherish with brutes, and even with vegetable
life, sympathies which are much more feebly felt by civilized men. The
popular traditions of the simpler peoples recognize a certain community of
nature between man, brute animals, and even plants; and this serves to
explain why the apologue or fable, which ascribes the power of speech and
the faculty of reason to birds, quadrupeds, insects, flowers, and trees, is one
of the earliest forms of literary composition.
the earliest dawn of civilization, the conquest of inorganic nature almost as
exclusively to the most advanced stages of artificial culture. Civilization has
added little to the number of vegetable or animal species grown in our fields
or bred in our folds—the cranberry and the wild grape being almost the
only plants which the Anglo-American has reclaimed out of our most native
flora and added to his harvests—while, on the contrary, the subjugation of
the inorganic forces, and the consequent extension of man's sway over, not
the annual products of the earth only, but her substance and her springs of
action, is almost entirely the work of highly refined and cultivated ages. The
employment of the elasticity of wood and of horn, as a projectile power in
the bow, is nearly universal among the rudest savages. The application of
compressed air to the same purpose, in the blowpipe, is more restricted, and
the use of the mechanical powers, the inclined plane, the wheel and axle,
and even the wedge and lever, seems almost unknown except to civilized
man. I have myself seen European peasants to whom one of the simplest
applications of this latter power was a revelation.
It is familiarly known to all who have occupied themselves with the
psychology and habits of the ruder races, and of persons with imperfectly
developed intellects in civilized life, that although these humble tribes and
individuals sacrifice, without scruple, the lives of the lower animals to the
gratification of their appetites and the supply of their other physical wants,
yet they nevertheless seem to cherish with brutes, and even with vegetable
life, sympathies which are much more feebly felt by civilized men. The
popular traditions of the simpler peoples recognize a certain community of
nature between man, brute animals, and even plants; and this serves to
explain why the apologue or fable, which ascribes the power of speech and
the faculty of reason to birds, quadrupeds, insects, flowers, and trees, is one
of the earliest forms of literary composition.
Page 77
In almost every wild tribe, some particular quadruped or bird, though
persecuted as a destroyer of other animals more useful to man, or hunted for
food, is regarded with peculiar respect, one might almost say, affection.
Some of the North American aboriginal nations celebrate a propitiatory
feast to the manes of the intended victim before they commence a bear
hunt; and the Norwegian peasantry have not only retained an old proverb
which ascribes to the same animal "ti Maends Styrke og tolo Maends Vid,"
ten men's strength and twelve men's cunning, but they still pay to him
something of the reverence with which ancient superstition invested him.
The student of Icelandic literature will find in the saga of Finnbogi hinn
rami a curious illustration of this feeling, in an account of a dialogue
between a Norwegian bear and an Icelandic champion—dumb show on the
part of Bruin, and chivalric words on that of Finnbogi—followed by a duel,
in which the latter, who had thrown away his arms and armor in order that
the combatants might meet on equal terms, was victorious. See also Friis,
Lappisk Mythologi, Christiania, 1871, section 37, and the earlier authors
there cited. Drummond Hay's very interesting work on Morocco contains
many amusing notices of a similar feeling entertained by the Moors towards
the redoubtable enemy of their flocks—the lion.
This sympathy helps us to understand how it is that most if not all the
domestic animals—if indeed they ever existed in a wild state—were
appropriated, reclaimed and trained before men had been gathered into
organized and fixed communities, that almost every known esculent plant
had acquired substantially its present artificial character, and that the
properties of nearly all vegetable drugs and poisons were known at the
remotest period to which historical records reach. Did nature bestow upon
primitive man some instinct akin to that by which she has been supposed to
teach the brute to select the nutritious and to reject the noxious vegetables
indiscriminately mixed in forest and pasture?
persecuted as a destroyer of other animals more useful to man, or hunted for
food, is regarded with peculiar respect, one might almost say, affection.
Some of the North American aboriginal nations celebrate a propitiatory
feast to the manes of the intended victim before they commence a bear
hunt; and the Norwegian peasantry have not only retained an old proverb
which ascribes to the same animal "ti Maends Styrke og tolo Maends Vid,"
ten men's strength and twelve men's cunning, but they still pay to him
something of the reverence with which ancient superstition invested him.
The student of Icelandic literature will find in the saga of Finnbogi hinn
rami a curious illustration of this feeling, in an account of a dialogue
between a Norwegian bear and an Icelandic champion—dumb show on the
part of Bruin, and chivalric words on that of Finnbogi—followed by a duel,
in which the latter, who had thrown away his arms and armor in order that
the combatants might meet on equal terms, was victorious. See also Friis,
Lappisk Mythologi, Christiania, 1871, section 37, and the earlier authors
there cited. Drummond Hay's very interesting work on Morocco contains
many amusing notices of a similar feeling entertained by the Moors towards
the redoubtable enemy of their flocks—the lion.
This sympathy helps us to understand how it is that most if not all the
domestic animals—if indeed they ever existed in a wild state—were
appropriated, reclaimed and trained before men had been gathered into
organized and fixed communities, that almost every known esculent plant
had acquired substantially its present artificial character, and that the
properties of nearly all vegetable drugs and poisons were known at the
remotest period to which historical records reach. Did nature bestow upon
primitive man some instinct akin to that by which she has been supposed to
teach the brute to select the nutritious and to reject the noxious vegetables
indiscriminately mixed in forest and pasture?
Page 78
This instinct, it must be admitted, is far from infallible, and, as has been
hundreds of times remarked by naturalists, it is in many cases not an
original faculty but an acquired and transmitted habit. It is a fact familiar to
persons engaged in sheep husbandry in New England—and I have seen it
confirmed by personal observation—that sheep bred where the common
laurel, as it is called, Kalmia angustifolia, abounds, almost always avoid
browsing upon the leaves of that plant, while those brought from districts
where laurel is unknown, and turned into pastures where it grows, very
often feed upon it and are poisoned by it. A curious acquired and hereditary
instinct, of a different character, may not improperly be noticed here. I refer
to that by which horses bred in provinces where quicksands are common
avoid their dangers or extricate themsleves from them. See Bremontier,
Memoire sur les Dunes, Annales des Ponts et Chaussees, 1833; premier
semestre, pp. 155-157.
It is commonly said in New England, and I believe with reason, that the
crows of this generation are wiser than their ancestors. Scarecrows which
were effectual fifty yeara ago are no longer respected by the plunderers of
the cornfield, and new terrors must from time to time be invented for its
protection.
Schroeder van der Kolk, in Het Verschil tusschen den Psychischen,
Aanleg van het Dier en van den Mensch, cites many interesting facts
respecting instincts lost, or newly developed and become hereditary, in the
lower animals, and he quotes Aristotle and Pliny as evidence that the
common quadrupeds and fowls of our fields and our poultry yards were
much less perfectly domesticated in their times than long, long ages of
servitude have now made them.
Among other inntances of obliterated instincts, this author states that in
Holland, where, for centuries, the young of the cow has been usually taken
hundreds of times remarked by naturalists, it is in many cases not an
original faculty but an acquired and transmitted habit. It is a fact familiar to
persons engaged in sheep husbandry in New England—and I have seen it
confirmed by personal observation—that sheep bred where the common
laurel, as it is called, Kalmia angustifolia, abounds, almost always avoid
browsing upon the leaves of that plant, while those brought from districts
where laurel is unknown, and turned into pastures where it grows, very
often feed upon it and are poisoned by it. A curious acquired and hereditary
instinct, of a different character, may not improperly be noticed here. I refer
to that by which horses bred in provinces where quicksands are common
avoid their dangers or extricate themsleves from them. See Bremontier,
Memoire sur les Dunes, Annales des Ponts et Chaussees, 1833; premier
semestre, pp. 155-157.
It is commonly said in New England, and I believe with reason, that the
crows of this generation are wiser than their ancestors. Scarecrows which
were effectual fifty yeara ago are no longer respected by the plunderers of
the cornfield, and new terrors must from time to time be invented for its
protection.
Schroeder van der Kolk, in Het Verschil tusschen den Psychischen,
Aanleg van het Dier en van den Mensch, cites many interesting facts
respecting instincts lost, or newly developed and become hereditary, in the
lower animals, and he quotes Aristotle and Pliny as evidence that the
common quadrupeds and fowls of our fields and our poultry yards were
much less perfectly domesticated in their times than long, long ages of
servitude have now made them.
Among other inntances of obliterated instincts, this author states that in
Holland, where, for centuries, the young of the cow has been usually taken
Page 79
from the dam at birth and fed by hand, calves, even if left with the mother,
make no attempt to suck; while in England, where calves are not weaned
until several weeks old, they resort to the udder as naturally as the young of
wild quadrupeds.-Ziel en Ligchaam, p. 128. n.
Perhaps the half-wild character ascribed by P. Laestadius and other
Swedish writers to the reindeer of Lapland, may be in some degree due to
the comparative shortness of the period during which he has been partially
tamed. The domestic swine bred in the woods of Hungary and the buffalo of
Southern Italy are so wild and savage as to be very dangerous to all but
their keepers. The former have relapsed into their original condition, the
latter, perhaps, have never been fully reclaimed from it.] and the destructive
agency of man becomes more and more energetic and unsparing as he
advances in civilization, until the impoverishment with which his
exhaustion of the natural resources of the soil is threatening him, at last
awakens him to the necessity of preserving what is left, if not of restoring
what has been wantonly wasted. The wandering savage grows no cultivated
vegetable, fells no forest, and extirpates no useful plant, no noxious weed.
If his skill in the chase enables him to entrap numbers of the animals on
which he feeds, he compensates this loss by destroying also the lion, the
tiger, the wolf, the otter, the seal, and the eagle, thus indirectly protecting
the feebler quadrupeds and fish and fowls, which would otherwise become
the booty of beasts and birds of prey. But with stationary life, or at latest
with the pastoral state, man at once commences an almost indiscriminate
warfare upon all the forms of animal and vegetable existence around him,
and as he advances in civilization, he gradually eradicates or transforms
every spontaneous product of the soil he occupies. [Footnote: The
difference between the relations of savage life, and of incipient civilization,
to nature, is well seen in that part of the valley of the Mississippi which was
once occupied by the mound builders and afterwards by the far less
developed Indian tribes. When the tillers of the fields, which must have
make no attempt to suck; while in England, where calves are not weaned
until several weeks old, they resort to the udder as naturally as the young of
wild quadrupeds.-Ziel en Ligchaam, p. 128. n.
Perhaps the half-wild character ascribed by P. Laestadius and other
Swedish writers to the reindeer of Lapland, may be in some degree due to
the comparative shortness of the period during which he has been partially
tamed. The domestic swine bred in the woods of Hungary and the buffalo of
Southern Italy are so wild and savage as to be very dangerous to all but
their keepers. The former have relapsed into their original condition, the
latter, perhaps, have never been fully reclaimed from it.] and the destructive
agency of man becomes more and more energetic and unsparing as he
advances in civilization, until the impoverishment with which his
exhaustion of the natural resources of the soil is threatening him, at last
awakens him to the necessity of preserving what is left, if not of restoring
what has been wantonly wasted. The wandering savage grows no cultivated
vegetable, fells no forest, and extirpates no useful plant, no noxious weed.
If his skill in the chase enables him to entrap numbers of the animals on
which he feeds, he compensates this loss by destroying also the lion, the
tiger, the wolf, the otter, the seal, and the eagle, thus indirectly protecting
the feebler quadrupeds and fish and fowls, which would otherwise become
the booty of beasts and birds of prey. But with stationary life, or at latest
with the pastoral state, man at once commences an almost indiscriminate
warfare upon all the forms of animal and vegetable existence around him,
and as he advances in civilization, he gradually eradicates or transforms
every spontaneous product of the soil he occupies. [Footnote: The
difference between the relations of savage life, and of incipient civilization,
to nature, is well seen in that part of the valley of the Mississippi which was
once occupied by the mound builders and afterwards by the far less
developed Indian tribes. When the tillers of the fields, which must have
Page 80
been cultivated to sustain the large population that once inhabited those
regions, perished, or were driven out, the soil fell back to the normal forest
state, and the savages who succeeded the more advanced race interfered
very little, if at all, with the ordinary course of spontaneous nature.]
Human and Brute Action Compared.
It is maintained by authorities as high as any known to modern science,
that the action of man upon nature, though greater in DEGREE, does not
differ in KIND from that of wild animals. It is perhaps impossible to
establish a radical distinction in genere between the two classes of effects,
but there is an essential difference between the motive of action which calls
out the energies of civilized man and the mere appetite which controls the
life of the beast. The action of man, indeed, is frequently followed by
unforeseen and undesired results, yet it is nevertheless guided by a self-
conscious will aiming as often at secondary and remote as at immediate
objects. The wild animal, on the other hand, acts instinctively, and, so far as
we are able to perceive, always with a view to single and direct purposes.
The backwoodsman and the beaver alike fell trees; the man that he may
convert the forest into an olive grove that will mature its fruit only for a
succeeding generation, the beaver that he may feed upon the bark of the
trees or use them in the construction of his habitation. The action of brutes
upon the material world is slow and gradual, and usually limited, in any
given case, to a narrow extent of territory. Nature is allowed time and
opportunity to set her restorative powers at work, and the destructive animal
has hardly retired from the field of his ravages before nature has repaired
the damages occasioned by his operations. In fact, he is expelled from the
scene by the very efforts which she makes for the restoration of her
dominion. Man, on the contrary, extends his action over vast spaces, his
revolutions are swift and radical, and his devastations are, for an almost
regions, perished, or were driven out, the soil fell back to the normal forest
state, and the savages who succeeded the more advanced race interfered
very little, if at all, with the ordinary course of spontaneous nature.]
Human and Brute Action Compared.
It is maintained by authorities as high as any known to modern science,
that the action of man upon nature, though greater in DEGREE, does not
differ in KIND from that of wild animals. It is perhaps impossible to
establish a radical distinction in genere between the two classes of effects,
but there is an essential difference between the motive of action which calls
out the energies of civilized man and the mere appetite which controls the
life of the beast. The action of man, indeed, is frequently followed by
unforeseen and undesired results, yet it is nevertheless guided by a self-
conscious will aiming as often at secondary and remote as at immediate
objects. The wild animal, on the other hand, acts instinctively, and, so far as
we are able to perceive, always with a view to single and direct purposes.
The backwoodsman and the beaver alike fell trees; the man that he may
convert the forest into an olive grove that will mature its fruit only for a
succeeding generation, the beaver that he may feed upon the bark of the
trees or use them in the construction of his habitation. The action of brutes
upon the material world is slow and gradual, and usually limited, in any
given case, to a narrow extent of territory. Nature is allowed time and
opportunity to set her restorative powers at work, and the destructive animal
has hardly retired from the field of his ravages before nature has repaired
the damages occasioned by his operations. In fact, he is expelled from the
scene by the very efforts which she makes for the restoration of her
dominion. Man, on the contrary, extends his action over vast spaces, his
revolutions are swift and radical, and his devastations are, for an almost
Page 81
incalculable time after he has withdrawn the arm that gave the blow,
irreparable. The form of geographical surface, and very probably the
climate of a given country, depend much on the character of the vegetable
life belonging to it. Man has, by domestication, greatly changed the habits
and properties of the plants he rears; he has, by voluntary selection,
immensely modified the forms and qualities of the animated creatures that
serve him; and he has, at the same time, completely rooted out many forms
of animal if not of vegetable being. [Footnote: Whatever may be thought of
the modification of organic species by natural selection, there is certainly no
evidence that animals have exerted upon any form of life an influence
analogous to that of domestication upon plants, quadrupeds, and birds
reared artificially by man; and this is as true of unforeseen as of purposely
effected improvements accomplished by voluntary selection of breeding
animals.
It is true that nature employs birds and quadrupeds for the dissemination
of vegetable and even of animal species. But when the bird drops the seed
of a fruit it has swallowed, and when the sheep transports in its fleece the
seed-vessel of a burdock from the plain to the mountain, its action is purely
mechanical and unconscious, and does not differ from that of the wind in
producing the same effect.] What is there, in the influence of brute life, that
corresponds to this We have no reason to believe that, in that portion of the
American continent which, though peopled by many tribes of quadruped
and fowl, remained uninhabited by man or only thinly occupied by purely,
savage tribes, any sensible geographical change had occurred within twenty
centuries before the epoch of discovery and colonization, while, during the
same period, man had changed millions of square miles, in the fairest and
most fertile regions of the Old World, into the barrenest deserts. The
ravages committed by man subvert the relations and destroy the balance
which nature had established between her organized and her inorganic
creations, and she avenges herself upon the intruder, by letting loose upon
irreparable. The form of geographical surface, and very probably the
climate of a given country, depend much on the character of the vegetable
life belonging to it. Man has, by domestication, greatly changed the habits
and properties of the plants he rears; he has, by voluntary selection,
immensely modified the forms and qualities of the animated creatures that
serve him; and he has, at the same time, completely rooted out many forms
of animal if not of vegetable being. [Footnote: Whatever may be thought of
the modification of organic species by natural selection, there is certainly no
evidence that animals have exerted upon any form of life an influence
analogous to that of domestication upon plants, quadrupeds, and birds
reared artificially by man; and this is as true of unforeseen as of purposely
effected improvements accomplished by voluntary selection of breeding
animals.
It is true that nature employs birds and quadrupeds for the dissemination
of vegetable and even of animal species. But when the bird drops the seed
of a fruit it has swallowed, and when the sheep transports in its fleece the
seed-vessel of a burdock from the plain to the mountain, its action is purely
mechanical and unconscious, and does not differ from that of the wind in
producing the same effect.] What is there, in the influence of brute life, that
corresponds to this We have no reason to believe that, in that portion of the
American continent which, though peopled by many tribes of quadruped
and fowl, remained uninhabited by man or only thinly occupied by purely,
savage tribes, any sensible geographical change had occurred within twenty
centuries before the epoch of discovery and colonization, while, during the
same period, man had changed millions of square miles, in the fairest and
most fertile regions of the Old World, into the barrenest deserts. The
ravages committed by man subvert the relations and destroy the balance
which nature had established between her organized and her inorganic
creations, and she avenges herself upon the intruder, by letting loose upon
Page 82
her defaced provinces destructive energies hitherto kept in check by organic
forces destined to be his best auxiliaries, but which he has unwisely
dispersed and driven from the field of action. When the forest is gone, the
great reservoir of moisture stored up in its vegetable mould is evaporated,
and returns only in deluges of rain to wash away the parched dust into
which that mould has been converted. The well-wooded and humid hills are
turned to ridges of dry rock, which encumbers the low grounds and chokes
the watercourses with its debris, and—except in countries favored with an
equable distribution of rain through the seasons, and a moderate and regular
inclination of surface—the whole earth, unless rescued by human art from
the physical degradation to which it tends, becomes an assemblage of bald
mountains, of barren, turfless hills, and of swampy and malarious plains.
There are parts of Asia Minor, of Northern Africa, of Greece, and even of
Alpine Europe, where the operation of causes set in action by man has
brought the face of the earth to a desolation almost as complete as that of
the moon; and though, within that brief space of time which we call "the
historical period," they are known to have been covered with luxuriant
woods, verdant pastures, and fertile meadows, they are now too far
deteriorated to be reclaimable by man, nor can they become again fitted for
human use, except through great geological changes, or other mysterious
influences or agencies of which we have no present knowledge, and over
which we have no prospective control. The earth is fast becoming an unfit
home for its noblest inhabitant, and another era of equal human crime and
human improvidence, and of like duration with that through which traces of
that crime and that improvidence extend, would reduce it to such a
condition of impoverished productiveness, of shattered surface, of climatic
excess, as to threaten the depravation, barbarism, and perhaps even
extinction of the species. [Footnote: —-"And it may be remarked that, as
the world has passed through these several stages of strife to produce a
Christendom, so by relaxing in the enterprises it has learnt, does it tend
forces destined to be his best auxiliaries, but which he has unwisely
dispersed and driven from the field of action. When the forest is gone, the
great reservoir of moisture stored up in its vegetable mould is evaporated,
and returns only in deluges of rain to wash away the parched dust into
which that mould has been converted. The well-wooded and humid hills are
turned to ridges of dry rock, which encumbers the low grounds and chokes
the watercourses with its debris, and—except in countries favored with an
equable distribution of rain through the seasons, and a moderate and regular
inclination of surface—the whole earth, unless rescued by human art from
the physical degradation to which it tends, becomes an assemblage of bald
mountains, of barren, turfless hills, and of swampy and malarious plains.
There are parts of Asia Minor, of Northern Africa, of Greece, and even of
Alpine Europe, where the operation of causes set in action by man has
brought the face of the earth to a desolation almost as complete as that of
the moon; and though, within that brief space of time which we call "the
historical period," they are known to have been covered with luxuriant
woods, verdant pastures, and fertile meadows, they are now too far
deteriorated to be reclaimable by man, nor can they become again fitted for
human use, except through great geological changes, or other mysterious
influences or agencies of which we have no present knowledge, and over
which we have no prospective control. The earth is fast becoming an unfit
home for its noblest inhabitant, and another era of equal human crime and
human improvidence, and of like duration with that through which traces of
that crime and that improvidence extend, would reduce it to such a
condition of impoverished productiveness, of shattered surface, of climatic
excess, as to threaten the depravation, barbarism, and perhaps even
extinction of the species. [Footnote: —-"And it may be remarked that, as
the world has passed through these several stages of strife to produce a
Christendom, so by relaxing in the enterprises it has learnt, does it tend
Page 83
downwards, through inverted steps, to wildness and the waste again. Let a
people give up their contest with moral evil; disregard the injustice, the
ignorance, the greediness, that may prevail among them, and part more and
more with the Christian element of their civilization; and in declining this
battle with sin, they will inevitably get embroiled with men. Threats of war
and revolution punish their unfaithfulness; and if then, instead of retracing
their steps, they yield again, and are driven before the storm, the very arts
they had created, the structures they had raised, the usages they had
established, are swept away; 'in that very day their thoughts perish.' The
portion they had reclaimed from the young earth's ruggedness is lost; and
failing to stand fast against man, they finally get embroiled with nature, and
are thrust down beneath her ever-living hand .-Martineau's Sermon, "The
Good Soldier of Jesus Christ."]
Physical Improvement.
True, there is a partial reverse to this picture. On narrow theatres, new
forests have been planted; inundations of flowing streams restrained by
heavy walls of masonry and other constructions; torrents compelled to aid,
by depositing the slime with which they are charged, in filling up lowlands,
and raising the level of morasses which their own overflows had created;
ground submerged by the encroachments of the ocean, or exposed to be
covered by its tides, has been rescued from its dominion by diking; swamps
and even lakes have been drained, and their beds brought within the domain
of agricultural industry; drifting coast dunes have been checked and made
productive by plantation; seas and inland waters have been repeopled with
fish, and even the sands of the Sahara have been fertilized by artesian
fountains. These achievements are more glorious than the proudest triumphs
of war, but, thus far, they give but faint hope that we shall yet make full
atonement for our spendthrift waste of the bounties of nature. [Footnote:
people give up their contest with moral evil; disregard the injustice, the
ignorance, the greediness, that may prevail among them, and part more and
more with the Christian element of their civilization; and in declining this
battle with sin, they will inevitably get embroiled with men. Threats of war
and revolution punish their unfaithfulness; and if then, instead of retracing
their steps, they yield again, and are driven before the storm, the very arts
they had created, the structures they had raised, the usages they had
established, are swept away; 'in that very day their thoughts perish.' The
portion they had reclaimed from the young earth's ruggedness is lost; and
failing to stand fast against man, they finally get embroiled with nature, and
are thrust down beneath her ever-living hand .-Martineau's Sermon, "The
Good Soldier of Jesus Christ."]
Physical Improvement.
True, there is a partial reverse to this picture. On narrow theatres, new
forests have been planted; inundations of flowing streams restrained by
heavy walls of masonry and other constructions; torrents compelled to aid,
by depositing the slime with which they are charged, in filling up lowlands,
and raising the level of morasses which their own overflows had created;
ground submerged by the encroachments of the ocean, or exposed to be
covered by its tides, has been rescued from its dominion by diking; swamps
and even lakes have been drained, and their beds brought within the domain
of agricultural industry; drifting coast dunes have been checked and made
productive by plantation; seas and inland waters have been repeopled with
fish, and even the sands of the Sahara have been fertilized by artesian
fountains. These achievements are more glorious than the proudest triumphs
of war, but, thus far, they give but faint hope that we shall yet make full
atonement for our spendthrift waste of the bounties of nature. [Footnote:
Page 84
The wonderful success which has attended the measures for subduing
torrents and preventing inundations employed in Southern France since
1863 and described in Chapter III., post, ought to be here noticed as a
splendid and most encouraging example of well-directed effort in the way
of physical restoration.]
Limits Of Human Power.
It is on the one hand, rash and unphilosophical to attempt to set limits to
the ultimate power of man over inorganic nature, and it is unprofitable, on
the other, to speculate on what may be accomplished by the discovery of
now unknown and unimagined natural forces, or even by the invention of
new arts and new processes. But since we have seen aerostation, the motive
power of elastic vapors, the wonders of modern telegraphy, the destructive
explosiveness of gunpowder, of nitro-glycerine, and even of a substance so
harmless, unresisting, and inert as cotton, there is little in the way of
mechanical achievement which seems hopelessly impossible, and it is hard
to restrain the imagination from wandering forward a couple of generations
to an epoch when our descendants shall have advanced as far beyond us in
physical conquest, as we have marched beyond the trophies erected by our
grandfathers. There are, nevertheless, in actual practice, limits to the
efficiency of the forces which we are now able to bring into the field, and
we must admit that, for the present, the agencies known to man and
controlled by him are inadequate to the reducing of great Alpine precipices
to such slopes as would enable them to support a vegetable clothing, or to
the covering of large extents of denuded rock with earth, and planting upon
them a forest growth. Yet among the mysteries which science is hereafter to
reveal, there may be still undiscovered methods of accomplishing even
grander wonders than these. Mechanical philosophers have suggested the
possibility of accumulating and treasuring up for human use some of the
torrents and preventing inundations employed in Southern France since
1863 and described in Chapter III., post, ought to be here noticed as a
splendid and most encouraging example of well-directed effort in the way
of physical restoration.]
Limits Of Human Power.
It is on the one hand, rash and unphilosophical to attempt to set limits to
the ultimate power of man over inorganic nature, and it is unprofitable, on
the other, to speculate on what may be accomplished by the discovery of
now unknown and unimagined natural forces, or even by the invention of
new arts and new processes. But since we have seen aerostation, the motive
power of elastic vapors, the wonders of modern telegraphy, the destructive
explosiveness of gunpowder, of nitro-glycerine, and even of a substance so
harmless, unresisting, and inert as cotton, there is little in the way of
mechanical achievement which seems hopelessly impossible, and it is hard
to restrain the imagination from wandering forward a couple of generations
to an epoch when our descendants shall have advanced as far beyond us in
physical conquest, as we have marched beyond the trophies erected by our
grandfathers. There are, nevertheless, in actual practice, limits to the
efficiency of the forces which we are now able to bring into the field, and
we must admit that, for the present, the agencies known to man and
controlled by him are inadequate to the reducing of great Alpine precipices
to such slopes as would enable them to support a vegetable clothing, or to
the covering of large extents of denuded rock with earth, and planting upon
them a forest growth. Yet among the mysteries which science is hereafter to
reveal, there may be still undiscovered methods of accomplishing even
grander wonders than these. Mechanical philosophers have suggested the
possibility of accumulating and treasuring up for human use some of the
Page 85
greater natural forces, which the action of the elements puts forth with such
astonishing energy. Could we gather, and bind, and make subservient to our
control, the power which a West Indian hurricane exerts through a small
area in one continuous blast, or the momentum expended by the waves in a
tempestuous winter, upon the breakwater at Cherbourg, [Footnote: In heavy
storms, the force of the waves as they strike against a sea-wall is from one
and a half to two tons to the square foot, and Stevenson, in one instance at
Skerryvore and in another at the Bell Rock lighthouse, found this force
equal to nearly three tons per foot. The seaward front of the breakwater at
Cherbourg exposes a surface about 2,500,000 square feet. In rough weather
the waves beat against this whole face, though at the depth of twenty-two
yards, which is the height of the breakwater, they exert a very much less
violent motive force than at and near the surface of the sea, because this
force diminishes in geometrical, and the distance below the surface
increases in arithmetical, proportion. The shock of the waves is received
several thousand times in the course of twenty four hours, and hence the
sum of impulse which the breakwater resists in one stormy day amounts to
many thousands of millions of tons. The breakwater is entirely an artificial
construction. If then man could accumulate and control the forces which he
is able effectually to resist, he might be said to be physically speaking,
omnipotent.] or the lifting power of the tide, for a month, at the head of the
Bay of Fundy, or the pressure of a square mile of sea water at the depth of
five thousand fathoms, or a moment of the might of an earthquake or a
volcano, our age—which moves no mountains and casts them into the sea
by faith alone—might hope to scarp the ragged walls of the Alps and
Pyrenees and Mount Taurus, robe them once more in a vegetation as rich as
that of their pristine woods, and turn their wasting torrents into refreshing
streams. [Footnote: Some well-known experiments show that it is quite
possible to accumulate the solar heat by a simple apparatus, and thus to
obtain a temperature which might be economically important even in the
astonishing energy. Could we gather, and bind, and make subservient to our
control, the power which a West Indian hurricane exerts through a small
area in one continuous blast, or the momentum expended by the waves in a
tempestuous winter, upon the breakwater at Cherbourg, [Footnote: In heavy
storms, the force of the waves as they strike against a sea-wall is from one
and a half to two tons to the square foot, and Stevenson, in one instance at
Skerryvore and in another at the Bell Rock lighthouse, found this force
equal to nearly three tons per foot. The seaward front of the breakwater at
Cherbourg exposes a surface about 2,500,000 square feet. In rough weather
the waves beat against this whole face, though at the depth of twenty-two
yards, which is the height of the breakwater, they exert a very much less
violent motive force than at and near the surface of the sea, because this
force diminishes in geometrical, and the distance below the surface
increases in arithmetical, proportion. The shock of the waves is received
several thousand times in the course of twenty four hours, and hence the
sum of impulse which the breakwater resists in one stormy day amounts to
many thousands of millions of tons. The breakwater is entirely an artificial
construction. If then man could accumulate and control the forces which he
is able effectually to resist, he might be said to be physically speaking,
omnipotent.] or the lifting power of the tide, for a month, at the head of the
Bay of Fundy, or the pressure of a square mile of sea water at the depth of
five thousand fathoms, or a moment of the might of an earthquake or a
volcano, our age—which moves no mountains and casts them into the sea
by faith alone—might hope to scarp the ragged walls of the Alps and
Pyrenees and Mount Taurus, robe them once more in a vegetation as rich as
that of their pristine woods, and turn their wasting torrents into refreshing
streams. [Footnote: Some well-known experiments show that it is quite
possible to accumulate the solar heat by a simple apparatus, and thus to
obtain a temperature which might be economically important even in the
Page 86
climate of Switzerland. Saussure, by receiving the sun's rays in a nest of
boxes blackened within and covered with glass, raised a thermometer
enclosed in the inner box to the boiling point; and under the more powerful
sun of the Cape of Good Hope, Sir John Hershel cooked the materials for a
family dinner by a similar process, using however, but at single box,
surrounded with dry sand and covered with two glasses. Why should not so
easy a method of economizing fuel be resorted to in Italy, in Spain, and
even in more northerly climate The unfortunate John Davidson records in
his journal that he saved fuel in Morocco by exposing his teakettle to the
sun on the roof of his house, where the water rose to the temperature of one
hundred and forty degrees, and, of course, needed little fire to bring it to
boil. But this was the direct and simple, not the concentrated or
accumulated heat of the sun.
On the utilizing of the solar heat, simply as heat, see the work of
Mouchot, La Chaleur solaire et ses applications industrielles. Paris, 1860.
The reciprocal convertibility of the natural forces has suggested the
possibility of advantageously converting the heat of the sun into mechanical
power. Ericsson calculates that in all latitudes between the equator and 45
degrees, a hundred square feet of surface exposed to the solar rays develop
continuously, for nine hours a day on an average, eight and one fifth horse-
power.
I do not know that any attempts have been made to accumulate and store
up, for use at pleasure, force derived from this powerful source.] Could this
old world, which man has overthrown, be rebuilded, could human cunning
rescue its wasted hillsides and its deserted plains from solitude or mere
nomade occupation, from barrenness, from nakedness, and from insalubrity,
and restore the ancient fertility and healthfulness of the Etruscan sea coast,
the Campagna and the Pontine marshes, of Calabria, of Sicily, of the
boxes blackened within and covered with glass, raised a thermometer
enclosed in the inner box to the boiling point; and under the more powerful
sun of the Cape of Good Hope, Sir John Hershel cooked the materials for a
family dinner by a similar process, using however, but at single box,
surrounded with dry sand and covered with two glasses. Why should not so
easy a method of economizing fuel be resorted to in Italy, in Spain, and
even in more northerly climate The unfortunate John Davidson records in
his journal that he saved fuel in Morocco by exposing his teakettle to the
sun on the roof of his house, where the water rose to the temperature of one
hundred and forty degrees, and, of course, needed little fire to bring it to
boil. But this was the direct and simple, not the concentrated or
accumulated heat of the sun.
On the utilizing of the solar heat, simply as heat, see the work of
Mouchot, La Chaleur solaire et ses applications industrielles. Paris, 1860.
The reciprocal convertibility of the natural forces has suggested the
possibility of advantageously converting the heat of the sun into mechanical
power. Ericsson calculates that in all latitudes between the equator and 45
degrees, a hundred square feet of surface exposed to the solar rays develop
continuously, for nine hours a day on an average, eight and one fifth horse-
power.
I do not know that any attempts have been made to accumulate and store
up, for use at pleasure, force derived from this powerful source.] Could this
old world, which man has overthrown, be rebuilded, could human cunning
rescue its wasted hillsides and its deserted plains from solitude or mere
nomade occupation, from barrenness, from nakedness, and from insalubrity,
and restore the ancient fertility and healthfulness of the Etruscan sea coast,
the Campagna and the Pontine marshes, of Calabria, of Sicily, of the
Page 87
Peloponnesus and insular and continental Greece, of Asia Minor, of the
slopes of Lebanon and Hermon, of Palestine, of the Syrian desert, of
Mesopotamia and the delta of the Euphrates, of the Cyrenaica, of Africa
proper, Numidia, and Mauritania, the thronging millions of Europe might
still find room on the Eastern continent, and the main current of emigration
be turned towards the rising instead of the setting sun.
But changes like these must await not only great political and moral
revolutions in the governments and peoples by whom these regions are now
possessed, but, especially, a command of pecuniary and of mechanical
means not at present enjoyed by these nations, and a more advanced and
generally diffused knowledge of the processes by which the amelioration of
soil and climate is possible than now anywhere exists. Until such
circumstances shall conspire to favor the work of geographical
regeneration, the countries I have mentioned, with here and there a local
exception, will continue to sink into yet deeper desolation, and in the
meantime the American continent, Southern Africa, Australia, New
Zealand, and the smaller oceanic islands, will be almost the only theatres
where man is engaged, on a great scale, in transforming the face of nature.
IMPORTANCE OF PHYSICAL CONSERVATION, AND
RESTORATION.
Comparatively short as is the period through which the colonization of
foreign lands by European emigrants extends, great and, it is to be feared,
sometimes irreparable injury has already been done in the various processes
by which man seeks to subjugate the virgin earth; and many provinces, first
trodden by the homo sapiens Europae within the last two centuries, begin to
show signs of that melancholy dilapidation which is now driving so many
of the peasantry of Europe from their native hearths. It is evidently a matter
of great moment, not only to the population of the states where these
slopes of Lebanon and Hermon, of Palestine, of the Syrian desert, of
Mesopotamia and the delta of the Euphrates, of the Cyrenaica, of Africa
proper, Numidia, and Mauritania, the thronging millions of Europe might
still find room on the Eastern continent, and the main current of emigration
be turned towards the rising instead of the setting sun.
But changes like these must await not only great political and moral
revolutions in the governments and peoples by whom these regions are now
possessed, but, especially, a command of pecuniary and of mechanical
means not at present enjoyed by these nations, and a more advanced and
generally diffused knowledge of the processes by which the amelioration of
soil and climate is possible than now anywhere exists. Until such
circumstances shall conspire to favor the work of geographical
regeneration, the countries I have mentioned, with here and there a local
exception, will continue to sink into yet deeper desolation, and in the
meantime the American continent, Southern Africa, Australia, New
Zealand, and the smaller oceanic islands, will be almost the only theatres
where man is engaged, on a great scale, in transforming the face of nature.
IMPORTANCE OF PHYSICAL CONSERVATION, AND
RESTORATION.
Comparatively short as is the period through which the colonization of
foreign lands by European emigrants extends, great and, it is to be feared,
sometimes irreparable injury has already been done in the various processes
by which man seeks to subjugate the virgin earth; and many provinces, first
trodden by the homo sapiens Europae within the last two centuries, begin to
show signs of that melancholy dilapidation which is now driving so many
of the peasantry of Europe from their native hearths. It is evidently a matter
of great moment, not only to the population of the states where these
Page 88
symptoms are manifesting themselves, but to the general interests of
humanity, that this decay should be arrested, and that the future operations
of rural husbandry and of forest industry, in districts yet remaining
substantially in their native condition, should be so conducted as to prevent
the widespread mischiefs which have been elsewhere produced by
thoughtless or wanton destruction of the natural safeguards of the soil. This
can be done only by the diffusion of knowledge on this subject among the
classes that, in earlier days, subdued and tilled ground in which they had no
vested rights, but who, in our time, own their woods, their pastures, and
their ploughlands as a perpetual possession for them and theirs, and have,
therefore, a strong interest in the protection of their domain against
deterioration.
PHYSICAL RESTORATION.
Many circumstances conspire to invest with great present interest the
questions: how far man can permanently modify and ameliorate those
physical conditions of terrestrial surface and climate on which his material
welfare depends; how far he can compensate, arrest, or retard the
deterioration which many of his agricultural and industrial processes tend to
produce; and how far he can restore fertility and salubrity to soil which his
follies or his crimes have made barren or pestilential. Among these
circumstances, the most prominent, perhaps, is the necessity of providing
new homes for a European population which is increasing more rapidly
than its means of subsistence, new physical comforts for classes of the
people that have now become too much enlightened and have imbibed too
much culture to submit to a longer deprivation of a share in the material
enjoyments which the privileged ranks have hitherto monopolized.
humanity, that this decay should be arrested, and that the future operations
of rural husbandry and of forest industry, in districts yet remaining
substantially in their native condition, should be so conducted as to prevent
the widespread mischiefs which have been elsewhere produced by
thoughtless or wanton destruction of the natural safeguards of the soil. This
can be done only by the diffusion of knowledge on this subject among the
classes that, in earlier days, subdued and tilled ground in which they had no
vested rights, but who, in our time, own their woods, their pastures, and
their ploughlands as a perpetual possession for them and theirs, and have,
therefore, a strong interest in the protection of their domain against
deterioration.
PHYSICAL RESTORATION.
Many circumstances conspire to invest with great present interest the
questions: how far man can permanently modify and ameliorate those
physical conditions of terrestrial surface and climate on which his material
welfare depends; how far he can compensate, arrest, or retard the
deterioration which many of his agricultural and industrial processes tend to
produce; and how far he can restore fertility and salubrity to soil which his
follies or his crimes have made barren or pestilential. Among these
circumstances, the most prominent, perhaps, is the necessity of providing
new homes for a European population which is increasing more rapidly
than its means of subsistence, new physical comforts for classes of the
people that have now become too much enlightened and have imbibed too
much culture to submit to a longer deprivation of a share in the material
enjoyments which the privileged ranks have hitherto monopolized.
Page 89
To supply new hives for the emigrant swarms, there are, first, the vast
unoccupied prairies and forests of America, of Australia, and of many other
great oceanic islands, the sparsely inhabited and still unexhausted soils of
Southern and even Central Africa, and, finally, the impoverished and half-
depopulated shores of the Mediterranean, and the interior of Asia Minor and
the farther East. To furnish to those who shall remain after emigration shall
have conveniently reduced the too dense population of many European
states, those means of sensuous and of intellectual well-being which are
styled "artificial wants" when demanded by the humble and the poor, but
are admitted to be "necessaries" when claimed by the noble and the rich, the
soil must be stimulated to its highest powers of production, and man's
utmost ingenuity and energy must be tasked to renovate a nature drained, by
his improvidence, of fountains which a wise economy would have made
plenteous and perennial sources of beauty, health, and wealth.
In those yet virgin lands which the progress of modern discovery in both
hemispheres has brought and is still bringing to the knowledge and control
of civilized man, not much improvement of great physical conditions is to
be looked for. The proportion of forest is indeed to be considerably reduced,
superfluous waters to be drawn off, and routes of internal communication to
be constructed; but the primitive geographical and climatic features of these
countries ought to be, as far as possible, retained.
In reclaiming and reoccupying lands laid waste by human improvidence
or malice, and abandoned by man, or occupied only by a nomade or thinly
scattered population, the task of the pioneer settler is of a very different
character. He is to become a co-worker with nature in the reconstruction of
the damaged fabric which the negligence or the wantonness of former
lodgers has rendered untenantable. He must aid her in reclothing the
mountain slopes with forests and vegetable mould, thereby restoring the
fountains which she provided to water them; in checking the devastating
unoccupied prairies and forests of America, of Australia, and of many other
great oceanic islands, the sparsely inhabited and still unexhausted soils of
Southern and even Central Africa, and, finally, the impoverished and half-
depopulated shores of the Mediterranean, and the interior of Asia Minor and
the farther East. To furnish to those who shall remain after emigration shall
have conveniently reduced the too dense population of many European
states, those means of sensuous and of intellectual well-being which are
styled "artificial wants" when demanded by the humble and the poor, but
are admitted to be "necessaries" when claimed by the noble and the rich, the
soil must be stimulated to its highest powers of production, and man's
utmost ingenuity and energy must be tasked to renovate a nature drained, by
his improvidence, of fountains which a wise economy would have made
plenteous and perennial sources of beauty, health, and wealth.
In those yet virgin lands which the progress of modern discovery in both
hemispheres has brought and is still bringing to the knowledge and control
of civilized man, not much improvement of great physical conditions is to
be looked for. The proportion of forest is indeed to be considerably reduced,
superfluous waters to be drawn off, and routes of internal communication to
be constructed; but the primitive geographical and climatic features of these
countries ought to be, as far as possible, retained.
In reclaiming and reoccupying lands laid waste by human improvidence
or malice, and abandoned by man, or occupied only by a nomade or thinly
scattered population, the task of the pioneer settler is of a very different
character. He is to become a co-worker with nature in the reconstruction of
the damaged fabric which the negligence or the wantonness of former
lodgers has rendered untenantable. He must aid her in reclothing the
mountain slopes with forests and vegetable mould, thereby restoring the
fountains which she provided to water them; in checking the devastating
Page 90
fury of torrents, and bringing back the surface drainage to its primitive
narrow channels; and in drying deadly morasses by opening the natural
sluices which have been choked up, and cutting new canals for drawing off
their stagnant waters. He must thus, on the one hand, create new reservoirs,
and, on the other, remove mischievous accumulations of moisture, thereby
equalizing and regulating the sources of atmospheric humidity and of
flowing water, both which are so essential to all vegetable growth, and, of
course, to human and lower animal life.
I have remarked that the effects of human action on the forms of the
earth's surface could not always be distinguished from those resulting from
geological causes, and there is also much uncertainty in respect to the
precise influence of the clearing and cultivating of the ground, and of other
rural operations, upon climate. It is disputed whether either the mean or the
extremes of temperature, the periods of the seasons, or the amount or
distribution of precipitation and of evaporation, in any country whose
annals are known, have undergone any change during the historical period.
It is, indeed, as has been already observed, impossible to doubt that many of
the operations of the pioneer settler TEND to produce great modifications
in atmospheric humidity, temperature, and electricity; but we are at present
unable to determine how far one set of effects is neutralized by another, or
compensated by unknown agencies. This question scientific research is
inadequate to solve, for want of the necessary data; but well conducted
observation, in regions now first brought under the occupation of man,
combined with such historical evidence as still exists, may be expected at
no distant period to throw much light on this subject.
Australia and New Zealand are, perhaps, the countries from which we
have a right to expect the fullest elucidation of these difficult and disputable
problems. Their colonization did not commence until the physical sciences
had become matter of utmost universal attention, and is, indeed, so recent
narrow channels; and in drying deadly morasses by opening the natural
sluices which have been choked up, and cutting new canals for drawing off
their stagnant waters. He must thus, on the one hand, create new reservoirs,
and, on the other, remove mischievous accumulations of moisture, thereby
equalizing and regulating the sources of atmospheric humidity and of
flowing water, both which are so essential to all vegetable growth, and, of
course, to human and lower animal life.
I have remarked that the effects of human action on the forms of the
earth's surface could not always be distinguished from those resulting from
geological causes, and there is also much uncertainty in respect to the
precise influence of the clearing and cultivating of the ground, and of other
rural operations, upon climate. It is disputed whether either the mean or the
extremes of temperature, the periods of the seasons, or the amount or
distribution of precipitation and of evaporation, in any country whose
annals are known, have undergone any change during the historical period.
It is, indeed, as has been already observed, impossible to doubt that many of
the operations of the pioneer settler TEND to produce great modifications
in atmospheric humidity, temperature, and electricity; but we are at present
unable to determine how far one set of effects is neutralized by another, or
compensated by unknown agencies. This question scientific research is
inadequate to solve, for want of the necessary data; but well conducted
observation, in regions now first brought under the occupation of man,
combined with such historical evidence as still exists, may be expected at
no distant period to throw much light on this subject.
Australia and New Zealand are, perhaps, the countries from which we
have a right to expect the fullest elucidation of these difficult and disputable
problems. Their colonization did not commence until the physical sciences
had become matter of utmost universal attention, and is, indeed, so recent
Page 91
that the memory of living men embraces the principal epochs of their
history; the peculiarities of their fauna, their flora, and their geology are
such as to have excited for them the liveliest interest of the votaries of
natural science; their mines have given their people the necessary wealth for
procuring the means of instrumental observation, and the leisure required
for the pursuit of scientific research; and large tracts of virgin forest and
natural meadows are rapidly passing under the control of civilized man.
Here, then, exist greater facilities and stronger motives for the careful study
of the topics in question than have ever been found combined in any other
theatre of European colonization.
In North America, the change from the natural to the artificial condition
of terrestrial surface began about the period when the most important
instruments of meteorological observation were invented. The first settlers
in the territory now constituting the United States and the British American
provinces had other things to do than to tabulate barometrical and
thermometrical readings, but there remain some interesting physical records
from the early days of the colonies, [Footnote: The Travels of Dr. Dwight,
president of Yale College, which embody the results of his personal
observations, and of his inquiries among the early settlers, in his vacation
excursions in the Northern States of the American Union, though presenting
few instrumental measurements or tabulated results, are of value for the
powers of observation they exhibit, and for the sound common sense with
which many natural phenomena, such for instance as the formation of the
river meadows, called "intervales," in New England, are explained. They
present a true and interesting picture of physical conditions, many of which
have long ceased to exist in the theatre of his researches, and of which few
other records are extant.] and there is still an immense extent of North
American soil where the industry and the folly of man have as yet produced
little appreciable change. Here, too, with the present increased facilities for
scientific observation, the future effects, direct a contingent, of man's
history; the peculiarities of their fauna, their flora, and their geology are
such as to have excited for them the liveliest interest of the votaries of
natural science; their mines have given their people the necessary wealth for
procuring the means of instrumental observation, and the leisure required
for the pursuit of scientific research; and large tracts of virgin forest and
natural meadows are rapidly passing under the control of civilized man.
Here, then, exist greater facilities and stronger motives for the careful study
of the topics in question than have ever been found combined in any other
theatre of European colonization.
In North America, the change from the natural to the artificial condition
of terrestrial surface began about the period when the most important
instruments of meteorological observation were invented. The first settlers
in the territory now constituting the United States and the British American
provinces had other things to do than to tabulate barometrical and
thermometrical readings, but there remain some interesting physical records
from the early days of the colonies, [Footnote: The Travels of Dr. Dwight,
president of Yale College, which embody the results of his personal
observations, and of his inquiries among the early settlers, in his vacation
excursions in the Northern States of the American Union, though presenting
few instrumental measurements or tabulated results, are of value for the
powers of observation they exhibit, and for the sound common sense with
which many natural phenomena, such for instance as the formation of the
river meadows, called "intervales," in New England, are explained. They
present a true and interesting picture of physical conditions, many of which
have long ceased to exist in the theatre of his researches, and of which few
other records are extant.] and there is still an immense extent of North
American soil where the industry and the folly of man have as yet produced
little appreciable change. Here, too, with the present increased facilities for
scientific observation, the future effects, direct a contingent, of man's
Page 92
labors, can be measured, and such precautions taken in those rural processes
which we call improvements, as to mitigate evils, perhaps, in some degree,
inseparable from every attempt to control the action of natural laws.
In order to arrive at safe conclusions, we must first obtain a more exact
knowledge of the topography, and of the present superficial and climatic
condition of countries where the natural surface is as yet more or less
unbroken. This can only be accomplished by accurate surveys, and by a
great mutiplication of the points of meteorological registry, [Footnote: The
general law of tempeture is that it decreases as we ascend. But in hilly areas
the law is reversed in cold, still weather, the cold air descending, by reason
of its greater gravity, into the valleys. If there be wind enough however, to
produce a disturbance and intermixture of higher and lower atmospheric
strata, this exception to the general law does not take place. These facts
have long been familiar to the common people of Switzerland and of New
England, but their importance has not been sufficiently taken into account
in the discussion of meterological observations. The descent of the cold air
and the rise of the warm effect the relative temperatures of hills and valleys
to a much greater extent that has been usually supposed. A gentleman well
known to me kept a thermometrical record for nearly a half century in a
New England county town, at an elevation of at least 1,5000 feet above the
sea. During these years his thermometer never fell lower that 26 degrees
Farrenheit, while at the shire town of the county, situated in a basin
thousand feet lower, and only tem miles distant, as well as at other points in
similar positions, the mercury froze several times in the same period]
already so numerous; and as, moreover, considerable changes in the
proportion of forest and of cultivated land, or of dry and wholly or partially
submerged surface, will often take place within brief periods, it is highly
desirable that the attention of observers, in whose neighborhood the
clearing of the soil, of the drainage of lakes and swamps, or other great
works of rural improvement, are going on or meditated, should be
which we call improvements, as to mitigate evils, perhaps, in some degree,
inseparable from every attempt to control the action of natural laws.
In order to arrive at safe conclusions, we must first obtain a more exact
knowledge of the topography, and of the present superficial and climatic
condition of countries where the natural surface is as yet more or less
unbroken. This can only be accomplished by accurate surveys, and by a
great mutiplication of the points of meteorological registry, [Footnote: The
general law of tempeture is that it decreases as we ascend. But in hilly areas
the law is reversed in cold, still weather, the cold air descending, by reason
of its greater gravity, into the valleys. If there be wind enough however, to
produce a disturbance and intermixture of higher and lower atmospheric
strata, this exception to the general law does not take place. These facts
have long been familiar to the common people of Switzerland and of New
England, but their importance has not been sufficiently taken into account
in the discussion of meterological observations. The descent of the cold air
and the rise of the warm effect the relative temperatures of hills and valleys
to a much greater extent that has been usually supposed. A gentleman well
known to me kept a thermometrical record for nearly a half century in a
New England county town, at an elevation of at least 1,5000 feet above the
sea. During these years his thermometer never fell lower that 26 degrees
Farrenheit, while at the shire town of the county, situated in a basin
thousand feet lower, and only tem miles distant, as well as at other points in
similar positions, the mercury froze several times in the same period]
already so numerous; and as, moreover, considerable changes in the
proportion of forest and of cultivated land, or of dry and wholly or partially
submerged surface, will often take place within brief periods, it is highly
desirable that the attention of observers, in whose neighborhood the
clearing of the soil, of the drainage of lakes and swamps, or other great
works of rural improvement, are going on or meditated, should be
Page 93
especially drawn not only to revolutions in atmospheric tempeture and
precipitation, but to the more easily ascertained and perhaps more important
local changes produced by these operations in the temperature and the
hygrometric state of the superficial strata of the earth, and in its
spontaneous vegetable and animal products.
The rapid extension of railroads, which now everywhere keep pace with,
and sometimes even precede, the occupation of new soil for agricultural
purposes, furnishes great facilities for enlarging our knowledge of the
topography of the territory they traverse, because their cuttings reveal the
composition and general structure of surface, and the inclination and
elevation of their lines constitute known hypsometrical sections, which give
numerous points of departure for the measurement of higher and lower
stations, and of course for determining the relief and depression of surface,
the slope of the beds of watercourses, and many other not less important
questions. [Footnote: Railroad surveys must be received with great caution
where any motive exists for COOKING them. Capitalists are shy of
investments in roads with steep grades, and of course it is important to
make a fair show of facilities in obtaining funds for new routes. Joint-stock
companies have no souls; their managers, in general, no consciences. Cases
can be cited where engineers and directors of railroads, with long grades
above one hundred foot to the mile, have regularly sworn in their annual
reports, for years in succession, that there were no grades upon their routes
exceeding half that elevation. In fact, every person conversant with the
history of these enterprises knows that in their public statements falsehood
is the rule, truth the exception.
What I am about to remark is not exactly relevant to my subject; but it is
hard to "get the floor" in the world's great debating society, and when a
speaker who has anything to say once finds access to the public ear, he must
make the must of his opportunity, without inquiring too nicely whether his
precipitation, but to the more easily ascertained and perhaps more important
local changes produced by these operations in the temperature and the
hygrometric state of the superficial strata of the earth, and in its
spontaneous vegetable and animal products.
The rapid extension of railroads, which now everywhere keep pace with,
and sometimes even precede, the occupation of new soil for agricultural
purposes, furnishes great facilities for enlarging our knowledge of the
topography of the territory they traverse, because their cuttings reveal the
composition and general structure of surface, and the inclination and
elevation of their lines constitute known hypsometrical sections, which give
numerous points of departure for the measurement of higher and lower
stations, and of course for determining the relief and depression of surface,
the slope of the beds of watercourses, and many other not less important
questions. [Footnote: Railroad surveys must be received with great caution
where any motive exists for COOKING them. Capitalists are shy of
investments in roads with steep grades, and of course it is important to
make a fair show of facilities in obtaining funds for new routes. Joint-stock
companies have no souls; their managers, in general, no consciences. Cases
can be cited where engineers and directors of railroads, with long grades
above one hundred foot to the mile, have regularly sworn in their annual
reports, for years in succession, that there were no grades upon their routes
exceeding half that elevation. In fact, every person conversant with the
history of these enterprises knows that in their public statements falsehood
is the rule, truth the exception.
What I am about to remark is not exactly relevant to my subject; but it is
hard to "get the floor" in the world's great debating society, and when a
speaker who has anything to say once finds access to the public ear, he must
make the must of his opportunity, without inquiring too nicely whether his
Page 94
observations are "in order." I shall harm no honest man by endeavoring, as I
have often done elsewhere, to excite the attention of thinking and
conscientious men to the dangers which threaten the great moral and even
political interests of Christendom, from the unscrupulousness of the private
associations that now control the monetary affairs, and regulate the transit
of persons and property, in almost every civilized country. More than one
American State is literally governed by unprincipled corporations, which
not only defy the legislative power, but have, too often, corrupted even the
administration of justice. The tremendous power of these associations is due
not merely to pecuniary corruption, but partly to an old legal superstition—
fostered by the decision of the Supreme Court of the United States in the
famous Dartmouth College case—in regard to the sacredness of corporate
prerogatives. There is no good reason why private rights derived from God
and the very constitution of society should be less respected than privileges
granted by legislatures. It should never be forgotten that no privilege can be
a right, and legislative bodies ought never to make a grant to a corporation,
without express reservation of what many sound jurists now hold to be
involved in the very nature of such grants, the power of revocation. Similar
evils have become almost equally rife in England, and on the Continent;
and I believe the decay of commercial morality, and of the sense of all
higher obligations than those of a pecuniary nature, on both sides of the
Atlantic, is to be ascribed more to the influence of joint-stock banks and
manufacturing and railway companies, to the workings, in short, of what is
called the principle of "associate action," than to any other one cause of
demoralization.
The apophthegm, "the world is governed too much," though unhappily
too truly spoken of many countries—and perhaps, in some aspects, true of
all—has done much mischief whenever it has been too unconditionally
accepted as a political axiom. The popular apprehension of being over-
governed, and, I am afraid, more emphatically the fear of being over-taxed,
have often done elsewhere, to excite the attention of thinking and
conscientious men to the dangers which threaten the great moral and even
political interests of Christendom, from the unscrupulousness of the private
associations that now control the monetary affairs, and regulate the transit
of persons and property, in almost every civilized country. More than one
American State is literally governed by unprincipled corporations, which
not only defy the legislative power, but have, too often, corrupted even the
administration of justice. The tremendous power of these associations is due
not merely to pecuniary corruption, but partly to an old legal superstition—
fostered by the decision of the Supreme Court of the United States in the
famous Dartmouth College case—in regard to the sacredness of corporate
prerogatives. There is no good reason why private rights derived from God
and the very constitution of society should be less respected than privileges
granted by legislatures. It should never be forgotten that no privilege can be
a right, and legislative bodies ought never to make a grant to a corporation,
without express reservation of what many sound jurists now hold to be
involved in the very nature of such grants, the power of revocation. Similar
evils have become almost equally rife in England, and on the Continent;
and I believe the decay of commercial morality, and of the sense of all
higher obligations than those of a pecuniary nature, on both sides of the
Atlantic, is to be ascribed more to the influence of joint-stock banks and
manufacturing and railway companies, to the workings, in short, of what is
called the principle of "associate action," than to any other one cause of
demoralization.
The apophthegm, "the world is governed too much," though unhappily
too truly spoken of many countries—and perhaps, in some aspects, true of
all—has done much mischief whenever it has been too unconditionally
accepted as a political axiom. The popular apprehension of being over-
governed, and, I am afraid, more emphatically the fear of being over-taxed,
Page 95
has had much to do with the general abandonment of certain governmental
duties by the ruling powers of most modern states. It is theoretically the
duty of government to provide all those public facilities of
intercommunication and commerce, which are essential to the prosperity of
civilized commonwealths, but which individual means are inadequate to
furnish, and for the due administration of which individual guarantees are
insufficient. Hence public roads, canals, railroads, postal communications,
the circulating medium of exchange whether metallic or representative,
armies, navies, being all matters in which the nation at large has a vastly
deeper interest than any private association can have, ought legitimately to
be constructed and provided only by that which is the visible
personification and embodiment of the nation, namely, its legislative head.
No doubt the organization and management of those insitutions by
government are liable, as are all things human, to great abuses. The
multiplication of public placeholders, which they imply, is a serious evil.
But the corruption thus engendered, foul as it is, does not strike so deep as
the rottenness of private corporations; and official rank, position, and duty
have, in practice, proved better securities for fidelity and pecuniary integrity
in the conduct of the interests in question, than the suretyships of private
corporate agents, whose bondsmen so often fail or abscond before their
principal is detected. Many theoretical statesmen have thought that
voluntary associations for strictly pecuniary and industrial purposes, and for
the construction and control of public works, might furnish, in democratic
countries, a compensation for the small and doubtful advantages, and at the
same time secure an exemption from the great and certain evils, of
aristocratic institutions. The example of the American States shows that
private corporations—whose rule of action is the interest of the association,
not the conscience of the individual—though composed of ultra-democratic
elements, may become most dangerous enemies to rational liberty, to the
duties by the ruling powers of most modern states. It is theoretically the
duty of government to provide all those public facilities of
intercommunication and commerce, which are essential to the prosperity of
civilized commonwealths, but which individual means are inadequate to
furnish, and for the due administration of which individual guarantees are
insufficient. Hence public roads, canals, railroads, postal communications,
the circulating medium of exchange whether metallic or representative,
armies, navies, being all matters in which the nation at large has a vastly
deeper interest than any private association can have, ought legitimately to
be constructed and provided only by that which is the visible
personification and embodiment of the nation, namely, its legislative head.
No doubt the organization and management of those insitutions by
government are liable, as are all things human, to great abuses. The
multiplication of public placeholders, which they imply, is a serious evil.
But the corruption thus engendered, foul as it is, does not strike so deep as
the rottenness of private corporations; and official rank, position, and duty
have, in practice, proved better securities for fidelity and pecuniary integrity
in the conduct of the interests in question, than the suretyships of private
corporate agents, whose bondsmen so often fail or abscond before their
principal is detected. Many theoretical statesmen have thought that
voluntary associations for strictly pecuniary and industrial purposes, and for
the construction and control of public works, might furnish, in democratic
countries, a compensation for the small and doubtful advantages, and at the
same time secure an exemption from the great and certain evils, of
aristocratic institutions. The example of the American States shows that
private corporations—whose rule of action is the interest of the association,
not the conscience of the individual—though composed of ultra-democratic
elements, may become most dangerous enemies to rational liberty, to the
Page 96
moral interests of the commonwealth, to the purity of legislation and of
judicial action, and to the sacredness of private rights.]
The geological, hydrographical, and topographical surveys, which almost
every general and even local government of the civilized world is carrying
on, are making yet more important contributions to our stock of
geographical and general physical knowledge, and, within a comparatively
short space, there will be an accumulation of well established constant and
historical facts, from which we can safely reason upon all the relations of
action and reaction between man and external nature.
But we are, even now, breaking up the floor and wainscoting and doors
and window frames of our dwelling, for fuel to warm our bodies and to
seethe our pottage, and the world cannot afford to wait till the slow and sure
progress of exact science has taught it a better economy. Many practical
lessons have been learned by the common observation of unschooled men;
and the teachings of simple experience, on topics where natural philosophy
has scarcely yet spoken, are not to be despised.
In these humble pages, which do not in the least aspire to rank among
scientific expositions of the laws of nature, I shall attempt to give the most
important practical conclusions suggested by the history of man's efforts to
replenish the earth and subdue it; and I shall aim to support those
conclusions by such facts and illustrations only as address themselves to the
understanding of every intelligent reader, and as are to be found recorded in
works capable of profitable perusal, or at least consultation, by persons who
have not enjoyed a special scientific training.
CHAPTER II.
judicial action, and to the sacredness of private rights.]
The geological, hydrographical, and topographical surveys, which almost
every general and even local government of the civilized world is carrying
on, are making yet more important contributions to our stock of
geographical and general physical knowledge, and, within a comparatively
short space, there will be an accumulation of well established constant and
historical facts, from which we can safely reason upon all the relations of
action and reaction between man and external nature.
But we are, even now, breaking up the floor and wainscoting and doors
and window frames of our dwelling, for fuel to warm our bodies and to
seethe our pottage, and the world cannot afford to wait till the slow and sure
progress of exact science has taught it a better economy. Many practical
lessons have been learned by the common observation of unschooled men;
and the teachings of simple experience, on topics where natural philosophy
has scarcely yet spoken, are not to be despised.
In these humble pages, which do not in the least aspire to rank among
scientific expositions of the laws of nature, I shall attempt to give the most
important practical conclusions suggested by the history of man's efforts to
replenish the earth and subdue it; and I shall aim to support those
conclusions by such facts and illustrations only as address themselves to the
understanding of every intelligent reader, and as are to be found recorded in
works capable of profitable perusal, or at least consultation, by persons who
have not enjoyed a special scientific training.
CHAPTER II.
Page 97
TRANSFER, MODIFICATION, AND EXTIRPATION OF VEGETABLE AND OF ANIMAL
SPECIES.
Modern geography takes account of organic life—Geographical
importance of plants—Origin of domestic vegetables-Transfer of vegetable
life—Objects of modern commerce-Foreign plants, how introduced—
Vegetable power of accommodation—Agricultural products of the United
States—Useful American plants grown in Europe—Extirpation of
vegetables—Animal life as a geological and geographical agency—Origin
and transfer of domestic quadrupeds—Extirpation of wild quadrupeds—
Large marine animals relatively unimportant in geography—Introduction
and breeding of fish—Destruction of fish—Geographical importance of
birds—Introduction of birds—Destruction of birds—Utility and destruction
of reptiles—Utility of insects and worms—Injury to the forest by insects—
Introduction of insects—Destruction of insects—Minute organisms.
MODERN GEOGRAPHY EMBRACES ORGANIC LIFE.
It was a narrow view of geography which confined that science to
delineation of terrestrial surface and outline, and to description of the
relative position and magnitude of land and water. In its improved form it
embraces not only the globe itself and the atmosphere which bathes it, but
the living things which vegetate or move upon it, the varied influences they
exert upon each other, the reciprocal action and reaction between them and
the earth they inhabit. Even if the end of geographical studies were only to
obtain a knowledge of the external forms of the mineral and fluid masses
which constitute the globe, it would still be necessary to take into account
the element of life; for every plant, every animal, is a geographical agency,
man a destructive, vegetables, and in some cases even wild beasts,
restorative powers. The rushing waters sweep down earth from the uplands;
in the first moment of repose, vegetation seeks to reestablish itself on the
SPECIES.
Modern geography takes account of organic life—Geographical
importance of plants—Origin of domestic vegetables-Transfer of vegetable
life—Objects of modern commerce-Foreign plants, how introduced—
Vegetable power of accommodation—Agricultural products of the United
States—Useful American plants grown in Europe—Extirpation of
vegetables—Animal life as a geological and geographical agency—Origin
and transfer of domestic quadrupeds—Extirpation of wild quadrupeds—
Large marine animals relatively unimportant in geography—Introduction
and breeding of fish—Destruction of fish—Geographical importance of
birds—Introduction of birds—Destruction of birds—Utility and destruction
of reptiles—Utility of insects and worms—Injury to the forest by insects—
Introduction of insects—Destruction of insects—Minute organisms.
MODERN GEOGRAPHY EMBRACES ORGANIC LIFE.
It was a narrow view of geography which confined that science to
delineation of terrestrial surface and outline, and to description of the
relative position and magnitude of land and water. In its improved form it
embraces not only the globe itself and the atmosphere which bathes it, but
the living things which vegetate or move upon it, the varied influences they
exert upon each other, the reciprocal action and reaction between them and
the earth they inhabit. Even if the end of geographical studies were only to
obtain a knowledge of the external forms of the mineral and fluid masses
which constitute the globe, it would still be necessary to take into account
the element of life; for every plant, every animal, is a geographical agency,
man a destructive, vegetables, and in some cases even wild beasts,
restorative powers. The rushing waters sweep down earth from the uplands;
in the first moment of repose, vegetation seeks to reestablish itself on the
Page 98
bared surface, and, by the slow deposit of its decaying products, to raise
again the soil which the torrent lhad lowered. So important an element of
reconstruction in this, that it has been seriously questioned whether, upon
the whole, vegetation does not contribute as much to elevate, as the waters
to depress, the level of the surface.
Whenever man has transported a plant from its native habitat to a new
soil, he has introduced a new geographical force to act upon it, and this
generally at the expense of some indigenous growth which the foreign
vegetable has supplanted. The new and the old plants are rarely the
equivalents of each other, and the substitution of an exotic for a native tree,
shrub, or grass, increases or diminishes the relative importance of the
vegetable element in thegeography of the country to which it is removed.
Further, man sows that he may reap. The products of agricultural industry
are not suffered to rot upon the ground, and thus raise it by an annual
stratum of new mould. They are gathered, transported to greater or less
distances, and after they have served their uses in human economy, they
enter, on the final decomposition of their elements, into new combinations,
and are only in smnall proportion returned to the soil on which they grew.
The roots of the grasses, and of many other cultivated plants, however,
usually remain and decay in the earth, and contribute to raise its surface,
though certainly not in the same degree as the forest.
The smaller vegetables which have taken the place of trees
unquestionably perform many of the same functions. They radiate heat, they
absorb gases, and exhale uncombined gases and watery vapor, and
consequently act upon the chemical constitution and hygrometrical
condition of the air, their roots penetrate the earth to greater depths than is
commonly supposed, and form an inextricable labyrinth of filaments which
bind the soil together and prevent its erosion by water. The broad-leaved
annuals and perennials, too, shade the ground, and prevent the evaporation
again the soil which the torrent lhad lowered. So important an element of
reconstruction in this, that it has been seriously questioned whether, upon
the whole, vegetation does not contribute as much to elevate, as the waters
to depress, the level of the surface.
Whenever man has transported a plant from its native habitat to a new
soil, he has introduced a new geographical force to act upon it, and this
generally at the expense of some indigenous growth which the foreign
vegetable has supplanted. The new and the old plants are rarely the
equivalents of each other, and the substitution of an exotic for a native tree,
shrub, or grass, increases or diminishes the relative importance of the
vegetable element in thegeography of the country to which it is removed.
Further, man sows that he may reap. The products of agricultural industry
are not suffered to rot upon the ground, and thus raise it by an annual
stratum of new mould. They are gathered, transported to greater or less
distances, and after they have served their uses in human economy, they
enter, on the final decomposition of their elements, into new combinations,
and are only in smnall proportion returned to the soil on which they grew.
The roots of the grasses, and of many other cultivated plants, however,
usually remain and decay in the earth, and contribute to raise its surface,
though certainly not in the same degree as the forest.
The smaller vegetables which have taken the place of trees
unquestionably perform many of the same functions. They radiate heat, they
absorb gases, and exhale uncombined gases and watery vapor, and
consequently act upon the chemical constitution and hygrometrical
condition of the air, their roots penetrate the earth to greater depths than is
commonly supposed, and form an inextricable labyrinth of filaments which
bind the soil together and prevent its erosion by water. The broad-leaved
annuals and perennials, too, shade the ground, and prevent the evaporation
Page 99
of moisture from its surface by wind and sun. [Footnote: It is impossible to
say how far the abstraction of water from the earth by broad-leaved field
and garden plants—such as maize, the gourd family, the cabbage, &c.—is
compensated by the condensation of dew, which sometimes pours from
them in a stream, by the exhalation of aqueous vapor from their leaves,
which is directly absorbed by the ground, and by the shelter they afford the
soil from sun and wind, thus preventing evaporation. American farmers
often say that after the leaves of Indian corn are large enough to "shade the
ground," there is little danger that the plants will suffer from drought; but it
is probable that the comparative security of the fields from this evil is in
port due to the fact that, at thin period of growth, the roots penetrate down
to a permanently humid stratum of soil, and draw from it the moisture they
require. Stirring the ground between the rows of maize with a light harrow
or cultivator, in very dry seasons, is often recommended as a preventive of
injury by drought. It would seem, indeed, that loosening and turning over
the surface earth might aggravate the evil by promoting the evaporation of
the little remaining moisture; but the practice is founded partly on the belief
that the hygroscopicity of the soil is increased by it to such a degree that it
gains more by absorption than it loses by evaporation, and partly on the
doctrine that to admit air to the rootlets, or at least to the earth near them, is
to supply directly elements of vegetable growth.] At a certain stage of
growth, grass land is probably a more energetic evaporator and refrigerator
than even the forest, but this powerful action is exerted, in its full intensity,
for a comparatively short time only, while trees continue such functions,
with unabated vigor, for many months in succession. Upon the whole, it
seems quite certain, that no cultivated ground is as efficient in tempering
climatic extremes, or in conservation of geographical surface and outline, as
is the soil which nature herself has planted.
ORIGIN OF DOMESTIC PLANTS.
say how far the abstraction of water from the earth by broad-leaved field
and garden plants—such as maize, the gourd family, the cabbage, &c.—is
compensated by the condensation of dew, which sometimes pours from
them in a stream, by the exhalation of aqueous vapor from their leaves,
which is directly absorbed by the ground, and by the shelter they afford the
soil from sun and wind, thus preventing evaporation. American farmers
often say that after the leaves of Indian corn are large enough to "shade the
ground," there is little danger that the plants will suffer from drought; but it
is probable that the comparative security of the fields from this evil is in
port due to the fact that, at thin period of growth, the roots penetrate down
to a permanently humid stratum of soil, and draw from it the moisture they
require. Stirring the ground between the rows of maize with a light harrow
or cultivator, in very dry seasons, is often recommended as a preventive of
injury by drought. It would seem, indeed, that loosening and turning over
the surface earth might aggravate the evil by promoting the evaporation of
the little remaining moisture; but the practice is founded partly on the belief
that the hygroscopicity of the soil is increased by it to such a degree that it
gains more by absorption than it loses by evaporation, and partly on the
doctrine that to admit air to the rootlets, or at least to the earth near them, is
to supply directly elements of vegetable growth.] At a certain stage of
growth, grass land is probably a more energetic evaporator and refrigerator
than even the forest, but this powerful action is exerted, in its full intensity,
for a comparatively short time only, while trees continue such functions,
with unabated vigor, for many months in succession. Upon the whole, it
seems quite certain, that no cultivated ground is as efficient in tempering
climatic extremes, or in conservation of geographical surface and outline, as
is the soil which nature herself has planted.
ORIGIN OF DOMESTIC PLANTS.
Page 100
One of the most important questions connected with our subject is: how far
we are to regard our cereal grains, our esculent bulbs and roots, and the
multiplied tree fruits of our gardens, as artificially modified and improved
forms of wild, self-propagating vegetation. The narratives of botanical
travellers have often announced the discovery of the original form and
habitat of domesticated plants, and scientific journals have described the
experiments by which the identity of particular wild and cultivated
vegetables has been thought to be established. It is confidently affirmed that
maize and the potato—which we must suppose to have been first cultivated
at a much later period than the breadstuffs and most other esculent
vegetables of Europe and the East—are found wild and self-propagating in
Spanish America, though in forms not recognizable by the common
observer as identical with the familiar corn and tuber of modern agriculture.
It was lately asserted, upon what seemed very strong evidence, that the
Aegilops ovata, a plant growing wild in Southern France, had been actually
converted into common wheat; but, upon a repetition of the experiments,
later observers have declared that the apparent change was only a case of
temporary hybridation or fecundation by the pollen of true wheat, and that
the grass alleged to be transformed into wheat could not be perpetuated as
such from its own seed.
The very great modifications which cultivated plants are constantly
undergoing under our eyes, and the numerous varieties and races which
spring up among them, certainly countenance the doctrine, that every
domesticated vegetable, however dependent upon human care for growth
and propagation in its present form, may have been really derived, by a long
Succession of changes, from some wild plant not now perhaps much
resembling it. [Footnote: What is the possible limit of such changes, we do
not know, but they may doubtless be carriad vastly beyond what experience
has yet shown to be practicable. Civilized man has experimented little on
wild plants, and especially on forest trees. He has indeed improved the fruit,
we are to regard our cereal grains, our esculent bulbs and roots, and the
multiplied tree fruits of our gardens, as artificially modified and improved
forms of wild, self-propagating vegetation. The narratives of botanical
travellers have often announced the discovery of the original form and
habitat of domesticated plants, and scientific journals have described the
experiments by which the identity of particular wild and cultivated
vegetables has been thought to be established. It is confidently affirmed that
maize and the potato—which we must suppose to have been first cultivated
at a much later period than the breadstuffs and most other esculent
vegetables of Europe and the East—are found wild and self-propagating in
Spanish America, though in forms not recognizable by the common
observer as identical with the familiar corn and tuber of modern agriculture.
It was lately asserted, upon what seemed very strong evidence, that the
Aegilops ovata, a plant growing wild in Southern France, had been actually
converted into common wheat; but, upon a repetition of the experiments,
later observers have declared that the apparent change was only a case of
temporary hybridation or fecundation by the pollen of true wheat, and that
the grass alleged to be transformed into wheat could not be perpetuated as
such from its own seed.
The very great modifications which cultivated plants are constantly
undergoing under our eyes, and the numerous varieties and races which
spring up among them, certainly countenance the doctrine, that every
domesticated vegetable, however dependent upon human care for growth
and propagation in its present form, may have been really derived, by a long
Succession of changes, from some wild plant not now perhaps much
resembling it. [Footnote: What is the possible limit of such changes, we do
not know, but they may doubtless be carriad vastly beyond what experience
has yet shown to be practicable. Civilized man has experimented little on
wild plants, and especially on forest trees. He has indeed improved the fruit,
Page 101
and developed new varieties, of the chestnut, by cultivation, and it is
observed that our American forest-tree nuts and berries, such as the
butternut and thewild mulberry, become larger and better flavored in a
single generation by planting and training. (Bryant, Forest Trees, 1871, pp.
99, 115.) Why should not the industry and ingenuity which have wrought
such wonders in our horticulture produce analogous results when applied to
the cultivation and amelioration of larger vegetables Might not, for instance,
the ivory nut, the fruit of the Phytelephas macrocarpa, possibly be so
increased in size as to serve nearly all the purposes of animal ivory now
becoming so scarce Might not the various milk-producing trees become, by
cultivation, a really important source of nutriment to the inhabitants of
warm climates In short, there is room to hope incalculable advantage from
the exercise of human skill in the improvement of yet untamed forms of
vegetable life.] But it is, in every case, a question of evidence.
The only satisfactory proof that a given wild plant is identical with a
given garden or field vegetable, is the test of experiment, the actual growing
of the one from the seed of the other, or the conversion of the one into the
other by transplantation and change of conditions. [Footnote: The poisonous
wild parsnip of New England has been often asserted to be convertible into
the common garden parsnip by cultivation, or rather to be the same
vegetable growing under different conditions, and it is said to be deprived
of its deleterious qualities simply by an increased luxuriance of growth in
rich, tilled earth. Wild medicinal plants, so important in the rustic materia
medica of New England—such as pennyroyal, for example—are generally
much less aromatic and powerful when cultivated in gardens than when
self-sown on meagre soils. On the other hand, the cinchona, lately
introduced from South America into British India and carefully cultivated
there, is found to be richer in quinine than the American tree.]
observed that our American forest-tree nuts and berries, such as the
butternut and thewild mulberry, become larger and better flavored in a
single generation by planting and training. (Bryant, Forest Trees, 1871, pp.
99, 115.) Why should not the industry and ingenuity which have wrought
such wonders in our horticulture produce analogous results when applied to
the cultivation and amelioration of larger vegetables Might not, for instance,
the ivory nut, the fruit of the Phytelephas macrocarpa, possibly be so
increased in size as to serve nearly all the purposes of animal ivory now
becoming so scarce Might not the various milk-producing trees become, by
cultivation, a really important source of nutriment to the inhabitants of
warm climates In short, there is room to hope incalculable advantage from
the exercise of human skill in the improvement of yet untamed forms of
vegetable life.] But it is, in every case, a question of evidence.
The only satisfactory proof that a given wild plant is identical with a
given garden or field vegetable, is the test of experiment, the actual growing
of the one from the seed of the other, or the conversion of the one into the
other by transplantation and change of conditions. [Footnote: The poisonous
wild parsnip of New England has been often asserted to be convertible into
the common garden parsnip by cultivation, or rather to be the same
vegetable growing under different conditions, and it is said to be deprived
of its deleterious qualities simply by an increased luxuriance of growth in
rich, tilled earth. Wild medicinal plants, so important in the rustic materia
medica of New England—such as pennyroyal, for example—are generally
much less aromatic and powerful when cultivated in gardens than when
self-sown on meagre soils. On the other hand, the cinchona, lately
introduced from South America into British India and carefully cultivated
there, is found to be richer in quinine than the American tree.]
Page 102
It is hardly contended that any of the cereals or other plants important as
human aliment, or as objects of agricultural industry, exist and propagate
themselves uncultivated in the same form and with the same properties as
when sown and reared by human art. [Footnote: Some recent observations
of Wetzatein are worthy of special notice. "The soil of the Hauran," he
remarks, "produces, in its primitive condition, much wild rye, which is not
known as a cultivated plant in Syria, and much wild barley and oats. These
cereals precisely resemble the corresponding cultivated plants in leaf, ear,
size, and height of straw, but their grains are sensibly flatter and poorer in
flour."—Reisebericht uber Hauran und die Trachenen, p. 40.
Some of the cereals are, to a certain extent, self-propagating in the soil
and climate of California. "VOLUNTEER crops are grown from the seed
which falls out in harvesting. Barley has been known to volunteer five crops
in succession."—Prayer-Frowd, Six Months in California, p. 189.] In fact,
the cases are rare where the identity of a wild with a domesticated plant is
considered by the best authorities as conclusively established, and we are
warranted in affirming of but few of the latter, as a historically known or
experimentally proved fact, that they ever did exist, or could exist,
independently of man. [Footnote: This remark is much less applicable to
fruit trees than to garden vegetables and the cerealia. The wild orange of
Florida, though once considered indigenous, is now generally thought by
botanists to be descended from the European orange introduced by the early
colonists. On the wild apple trees of Massachusetts see an interesting
chapter in Thoreau, Excursions. The fig and the olive are found growing
wild in every country where those trees are cultivated The wild fig differs
from the domesticated in its habits, its season of fructification, and its insect
population, but is, I believe, not specifically distinguishable from the garden
fig, though I do not know that it is reclaimable by cultivation. The wild
olive, which is so abundant in the Tuscan Maremma, produces good fruit
without further care, when thinned out and freed from the shade of other
human aliment, or as objects of agricultural industry, exist and propagate
themselves uncultivated in the same form and with the same properties as
when sown and reared by human art. [Footnote: Some recent observations
of Wetzatein are worthy of special notice. "The soil of the Hauran," he
remarks, "produces, in its primitive condition, much wild rye, which is not
known as a cultivated plant in Syria, and much wild barley and oats. These
cereals precisely resemble the corresponding cultivated plants in leaf, ear,
size, and height of straw, but their grains are sensibly flatter and poorer in
flour."—Reisebericht uber Hauran und die Trachenen, p. 40.
Some of the cereals are, to a certain extent, self-propagating in the soil
and climate of California. "VOLUNTEER crops are grown from the seed
which falls out in harvesting. Barley has been known to volunteer five crops
in succession."—Prayer-Frowd, Six Months in California, p. 189.] In fact,
the cases are rare where the identity of a wild with a domesticated plant is
considered by the best authorities as conclusively established, and we are
warranted in affirming of but few of the latter, as a historically known or
experimentally proved fact, that they ever did exist, or could exist,
independently of man. [Footnote: This remark is much less applicable to
fruit trees than to garden vegetables and the cerealia. The wild orange of
Florida, though once considered indigenous, is now generally thought by
botanists to be descended from the European orange introduced by the early
colonists. On the wild apple trees of Massachusetts see an interesting
chapter in Thoreau, Excursions. The fig and the olive are found growing
wild in every country where those trees are cultivated The wild fig differs
from the domesticated in its habits, its season of fructification, and its insect
population, but is, I believe, not specifically distinguishable from the garden
fig, though I do not know that it is reclaimable by cultivation. The wild
olive, which is so abundant in the Tuscan Maremma, produces good fruit
without further care, when thinned out and freed from the shade of other
Page 103
trees, and is particularly suited for grafting. See Salvagnoli, Memorie sulle
Maremme, pp. 63-73. The olive is indigenous in Syria and in the Punjaub,
and forms vast forests in the Himalayas at from 1,400 to 2,100 feet above
the level of the sea.—Cleghorn, Memoir on the Timber procured from the
Indus, etc., pp. 8-15. Fraas, Klima und Pfanzenwelt in der Zeit, pp. 35-38,
gives, upon the authority of Link and other botanical writers, a lift of the
native habitats of most cereals and of many fruits, or at least of localities
where those plants are said to be now found wild; but the data do not appear
to rest, in general, upon very trustworthy evidence. Theoretically, there can
be little doubt that all our cultivated plants are modified forms of
spontaneous vegetation, though the connection is not historically shown,
nor are we able to say that the originals of some domesticated vegetables
may not be now extinct and unrepresented in the existing wild flora. See, on
this subject, Humboldt, Ansichten der Natur, i., pp. 208, 209.
The Adams of modern botany and zoology have been put to hard shifts in
finding names for the multiplied organisms which the Creator has brought
before them, "to see what they would call them;" and naturalists and
philosophers have shown much moral courage in setting at naught the law
of philology in the coinage of uncouth words to express scientific Ideas. It
is much to be wished that some bold neologist would devise English
technical equivalents for the German verwildert, run-wild, and veredelt,
improved by cultivation.]
Transfer of Vegetable Life.
It belongs to vegetable and animal geography, which are almost sciences
of themselves, to point out in detail what man has done to change the
distribution of plants and of animated life and to revolutionize the aspect of
organic nature; but some of the more important facts bearing on the first
branch of this subject may pertinently be introduced here. Most of the
Maremme, pp. 63-73. The olive is indigenous in Syria and in the Punjaub,
and forms vast forests in the Himalayas at from 1,400 to 2,100 feet above
the level of the sea.—Cleghorn, Memoir on the Timber procured from the
Indus, etc., pp. 8-15. Fraas, Klima und Pfanzenwelt in der Zeit, pp. 35-38,
gives, upon the authority of Link and other botanical writers, a lift of the
native habitats of most cereals and of many fruits, or at least of localities
where those plants are said to be now found wild; but the data do not appear
to rest, in general, upon very trustworthy evidence. Theoretically, there can
be little doubt that all our cultivated plants are modified forms of
spontaneous vegetation, though the connection is not historically shown,
nor are we able to say that the originals of some domesticated vegetables
may not be now extinct and unrepresented in the existing wild flora. See, on
this subject, Humboldt, Ansichten der Natur, i., pp. 208, 209.
The Adams of modern botany and zoology have been put to hard shifts in
finding names for the multiplied organisms which the Creator has brought
before them, "to see what they would call them;" and naturalists and
philosophers have shown much moral courage in setting at naught the law
of philology in the coinage of uncouth words to express scientific Ideas. It
is much to be wished that some bold neologist would devise English
technical equivalents for the German verwildert, run-wild, and veredelt,
improved by cultivation.]
Transfer of Vegetable Life.
It belongs to vegetable and animal geography, which are almost sciences
of themselves, to point out in detail what man has done to change the
distribution of plants and of animated life and to revolutionize the aspect of
organic nature; but some of the more important facts bearing on the first
branch of this subject may pertinently be introduced here. Most of the
Page 104
cereal grains, the pulse, the edible roots, the tree fruits, and other important
forms of esculent vegetation grown in Europe and the United States are
believed, and—if the testimony of Pliny and other ancient naturalists is to
be depended upon—many of them are historically known, to have
originated in the temperate climates of Asia. The agriculture of even so old
a country as Egypt has been almost completely revolutionized by the
introduction of foreign plants, within the historical period. "With the
exception of wheat," says Hehn, "the Nile valley now yields only new
products, cotton, rice, sugar, indigo, sorghum, dates," being all unknown to
its most ancient rural husbandry. [Footnote: On these points see the learned
work of Hehn, Kultur. Pflanzen und Thiere in ihrem Uebergang aus Asien,
1870. On the migration of plants generally, see Lyell, Principles of Geology,
10th ed., vol. ii., c.] The wine grape has been thought to be truly indigenous
only in the regions bordering on the eastern end of the Black Sea, where it
now, particularly on the banks of the Rion, the ancient Phasis, propagates
itself spontaneously, and grows with unexampled luxuriance. [Footnote:
The vine-wood planks of the ancient great door of the cathedral at Ravenna,
which measured thirteen feet in length by a foot and a quarter in width, are
traditionally said to have boon brought from the Black Sea, by way of
Constantinople, about the eleventh or twelfth century. Vines of such
dimension are now very rarely found in any other part of the East, and,
though I have taken some pains on the subject, I never found in Syria or in
Turkey a vine stock exceeding six inches in diameter, bark excluded.
Schulz, however, saw at Beitschin, near Ptolemais, a vine measuring
eighteen inches in diameter. Strabo speaks of vine-stocks in Margiana
(Khorasan) of such dimension that two men, with outstretched arms, could
scarcely embrace them. See Strabo, ed. Casaubon, pp. 78, 516, 826. Statues
of vine wood are mentioned by ancient writers. Very large vine-stems are
not common in Italy, but the vine-wood panels of the door of the chapter-
hall of the church of St. John at Saluzzo are not less than ten inches in
forms of esculent vegetation grown in Europe and the United States are
believed, and—if the testimony of Pliny and other ancient naturalists is to
be depended upon—many of them are historically known, to have
originated in the temperate climates of Asia. The agriculture of even so old
a country as Egypt has been almost completely revolutionized by the
introduction of foreign plants, within the historical period. "With the
exception of wheat," says Hehn, "the Nile valley now yields only new
products, cotton, rice, sugar, indigo, sorghum, dates," being all unknown to
its most ancient rural husbandry. [Footnote: On these points see the learned
work of Hehn, Kultur. Pflanzen und Thiere in ihrem Uebergang aus Asien,
1870. On the migration of plants generally, see Lyell, Principles of Geology,
10th ed., vol. ii., c.] The wine grape has been thought to be truly indigenous
only in the regions bordering on the eastern end of the Black Sea, where it
now, particularly on the banks of the Rion, the ancient Phasis, propagates
itself spontaneously, and grows with unexampled luxuriance. [Footnote:
The vine-wood planks of the ancient great door of the cathedral at Ravenna,
which measured thirteen feet in length by a foot and a quarter in width, are
traditionally said to have boon brought from the Black Sea, by way of
Constantinople, about the eleventh or twelfth century. Vines of such
dimension are now very rarely found in any other part of the East, and,
though I have taken some pains on the subject, I never found in Syria or in
Turkey a vine stock exceeding six inches in diameter, bark excluded.
Schulz, however, saw at Beitschin, near Ptolemais, a vine measuring
eighteen inches in diameter. Strabo speaks of vine-stocks in Margiana
(Khorasan) of such dimension that two men, with outstretched arms, could
scarcely embrace them. See Strabo, ed. Casaubon, pp. 78, 516, 826. Statues
of vine wood are mentioned by ancient writers. Very large vine-stems are
not common in Italy, but the vine-wood panels of the door of the chapter-
hall of the church of St. John at Saluzzo are not less than ten inches in
Page 105
width, and I observed not long since, in a garden at Pie di Mulera, a vine
stock with a circumference of thirty inches.] But some species of the vine
seem native to Europe, and many varieties of grape have been too long
known as common to every part of the United States to admit of the
supposition that they were introduced by European colonists. [Footnote:
The Northmen who—as I think it has been indisputably established by
Professor Rafn of Copenhagen—visited the coast of Massachusetts about
theyear 1000, found grapes growing there in profusion, and the wild vine
still flourishes in great variety and abundance in the southeastern counties
of that State. The townships in the vicinity of the Dighton rock, supposed
by many—with whom, however, I am sorry I cannot agree—to bear a
Scandinavian inscription, abound in wild vines. According to Laudonniere,
Histoire Notable de la Florida, reprint, Paris, 1853, p 5, the French
navigators in 1562 found in that peninsula "wild vines which climb the trees
and produce good grapes."]
OBJECTS OF MODERN COMMERCE.
It is an interesting fact that the commerce—or at least the maritime carrying
trade—and the agricultural and mechanical industry of the world are, in
very large proportion, dependent on vegetable and animal products little or
not at all known to ancient Greek, Roman, and Jewish civilization. In many
instances, the chief supply of these articles comes from countries to which
they are probably indigenous, and where they are still almost exclusively
grown; but in most cases, the plants or animals from which they are derived
have been introduced by man into regions now remarkable for their
successful cultivation, and that, too, in comparatively recent times, or, in
other words, within two or three centuries.
stock with a circumference of thirty inches.] But some species of the vine
seem native to Europe, and many varieties of grape have been too long
known as common to every part of the United States to admit of the
supposition that they were introduced by European colonists. [Footnote:
The Northmen who—as I think it has been indisputably established by
Professor Rafn of Copenhagen—visited the coast of Massachusetts about
theyear 1000, found grapes growing there in profusion, and the wild vine
still flourishes in great variety and abundance in the southeastern counties
of that State. The townships in the vicinity of the Dighton rock, supposed
by many—with whom, however, I am sorry I cannot agree—to bear a
Scandinavian inscription, abound in wild vines. According to Laudonniere,
Histoire Notable de la Florida, reprint, Paris, 1853, p 5, the French
navigators in 1562 found in that peninsula "wild vines which climb the trees
and produce good grapes."]
OBJECTS OF MODERN COMMERCE.
It is an interesting fact that the commerce—or at least the maritime carrying
trade—and the agricultural and mechanical industry of the world are, in
very large proportion, dependent on vegetable and animal products little or
not at all known to ancient Greek, Roman, and Jewish civilization. In many
instances, the chief supply of these articles comes from countries to which
they are probably indigenous, and where they are still almost exclusively
grown; but in most cases, the plants or animals from which they are derived
have been introduced by man into regions now remarkable for their
successful cultivation, and that, too, in comparatively recent times, or, in
other words, within two or three centuries.
Page 106
Something of detail on this subject cannot, I think, fail to prove
interesting. Pliny mentions about thirty or forty oils as known to the
ancients, of which only olive, sesame, rape seed and walnut oil—for except
in one or two doubtful passages I find in this author no notice of linseed oil
—appear to have been used in such quantities as to have had any serious
importance in the carrying trade. At the present time, the new oils, linseed
oil, the oil of the whale and other largeo marine animals, petroleum—of
which the total consumption of the world in 1871 is estimated at 6,000,000
barrels, the port of Philadelphia alone exporting 56,000,000 gallons in that
year—palm-oil recently introduced into commerce, and now imported into
England from the coast of Africa at the rate of forty or fifty thousand tuns a
year, these alone undoubtedly give employment to more shipping than the
whole commerce of Italy—with the exception of wheat—at the most
flourishing period of the Roman empire. [Footnote: A very few years since,
the United States had more than six hundred large ships engaged in the
whale fishery, and the number of American whalers, in spite of the
introduction of many now sources of oils, still amounts to two hundred and
fifty.
The city of Rome imported from Sicily, from Africa, and from the
Levant, enormous quantities of grain for gratuitous distribution among the
lower classes of the capital. The pecuniary value of the gems, the spices, the
unguents, the perfumes, the cosmetics and the tissues, which came
principally from the East, was great, but these articles were neither heavy
nor bulky and their transportation required but a small amount of shipping.
The marbles, the obelisks, the statuary and other objects of art plundered in
conquered provinces by Roman generals and governors, the wild animals,
such as elephants, rhinoceroses, hippopotami, camelopards and the larger
beasts of prey imported for slaughter at the public games, and the prisoners
captured in foreign wars and brought to Italy for sale as slaves or butchery
as gladiators, furnished employment for much more tonnage than all the
interesting. Pliny mentions about thirty or forty oils as known to the
ancients, of which only olive, sesame, rape seed and walnut oil—for except
in one or two doubtful passages I find in this author no notice of linseed oil
—appear to have been used in such quantities as to have had any serious
importance in the carrying trade. At the present time, the new oils, linseed
oil, the oil of the whale and other largeo marine animals, petroleum—of
which the total consumption of the world in 1871 is estimated at 6,000,000
barrels, the port of Philadelphia alone exporting 56,000,000 gallons in that
year—palm-oil recently introduced into commerce, and now imported into
England from the coast of Africa at the rate of forty or fifty thousand tuns a
year, these alone undoubtedly give employment to more shipping than the
whole commerce of Italy—with the exception of wheat—at the most
flourishing period of the Roman empire. [Footnote: A very few years since,
the United States had more than six hundred large ships engaged in the
whale fishery, and the number of American whalers, in spite of the
introduction of many now sources of oils, still amounts to two hundred and
fifty.
The city of Rome imported from Sicily, from Africa, and from the
Levant, enormous quantities of grain for gratuitous distribution among the
lower classes of the capital. The pecuniary value of the gems, the spices, the
unguents, the perfumes, the cosmetics and the tissues, which came
principally from the East, was great, but these articles were neither heavy
nor bulky and their transportation required but a small amount of shipping.
The marbles, the obelisks, the statuary and other objects of art plundered in
conquered provinces by Roman generals and governors, the wild animals,
such as elephants, rhinoceroses, hippopotami, camelopards and the larger
beasts of prey imported for slaughter at the public games, and the prisoners
captured in foreign wars and brought to Italy for sale as slaves or butchery
as gladiators, furnished employment for much more tonnage than all the
Page 107
legitimate commerce of the empire, with the possible exception of wheat.
Independently of the direct testimony of Latin authors, the Greek statuary,
the Egyptian obelisks, and the vast quantities of foreign marbles, granite,
parphyry, basalt, and other stones used in sculpture and in architecture,
which have been found in the remains of ancient Rome, show that the
Imperial capital must have employed an immense amount of tonnage in the
importation of heavy articles for which there could have been no return
freight, unless in the way of military transportation. Some of the Egyptian
obelisks at Rome weigh upwards of four hundred tons, and many of the red
granite columns from the same country must have exceeded one hundred
tons. Greek and African marbles were largely used not only for columns,
contablatures, and solid walls, but for casing the exterior and veneering the
interior of public and private buildings. Scaurus imported, for the scene
alone of a temporary theatre designed to stand scarcely for a month, three
hundred and sixty columns, which were disposed in three tiers, the lower
range being forty-two feet in height—See Pliny, Nat. Hist., Lib. xxxvi. Italy
produced very little for export, and her importations, when not consisting of
booty, were chiefly paid for in coin which was principally either the spoil of
war or the fruit of official extortion.]
England imports annually about 600,000 tons of sugar, 100,000 tons of
jute, and about the same quantity of esparto, six million tons of cotton, of
which the value of $30,000,000 is exported again in the form of
manufactured, goods—including, by a strange industrial revolution, a large
amount of cotton yarn and cotton tissues sent to India and directly or
indirectly paid for by raw cotton to be manufactured in England—30,000
tons of tobacco, from 100,000 to 350,000 tons of guano, hundreds of
thousands of tons of tea, coffee, cacao, caoutchone, gutta-percha and
numerous other important articles of trade wholly unknown, as objects of
commerce, to the ancient European world; and this immense importation is
balanced by a corresponding amount of exportation, not consisting,
Independently of the direct testimony of Latin authors, the Greek statuary,
the Egyptian obelisks, and the vast quantities of foreign marbles, granite,
parphyry, basalt, and other stones used in sculpture and in architecture,
which have been found in the remains of ancient Rome, show that the
Imperial capital must have employed an immense amount of tonnage in the
importation of heavy articles for which there could have been no return
freight, unless in the way of military transportation. Some of the Egyptian
obelisks at Rome weigh upwards of four hundred tons, and many of the red
granite columns from the same country must have exceeded one hundred
tons. Greek and African marbles were largely used not only for columns,
contablatures, and solid walls, but for casing the exterior and veneering the
interior of public and private buildings. Scaurus imported, for the scene
alone of a temporary theatre designed to stand scarcely for a month, three
hundred and sixty columns, which were disposed in three tiers, the lower
range being forty-two feet in height—See Pliny, Nat. Hist., Lib. xxxvi. Italy
produced very little for export, and her importations, when not consisting of
booty, were chiefly paid for in coin which was principally either the spoil of
war or the fruit of official extortion.]
England imports annually about 600,000 tons of sugar, 100,000 tons of
jute, and about the same quantity of esparto, six million tons of cotton, of
which the value of $30,000,000 is exported again in the form of
manufactured, goods—including, by a strange industrial revolution, a large
amount of cotton yarn and cotton tissues sent to India and directly or
indirectly paid for by raw cotton to be manufactured in England—30,000
tons of tobacco, from 100,000 to 350,000 tons of guano, hundreds of
thousands of tons of tea, coffee, cacao, caoutchone, gutta-percha and
numerous other important articles of trade wholly unknown, as objects of
commerce, to the ancient European world; and this immense importation is
balanced by a corresponding amount of exportation, not consisting,
Page 108
however, by any means, exclusively of articles new to commerce.
[Footnote: Many of these articles would undoubtedly have been made
known to the Greeks and Romans and have figured in their commerce, but
for the slowness and costliness of ancient navigation, which, in the seas
familiar to them, was suspended for a full third of the year from the
inability of their vessels to cope with winter weather. The present speed and
economy of transportation have wrought and are still working strange
commercial and industrial revolutions. Algeria now supplies Northern
Germany with fresh cauliflowers, and in the early spring the market-
gardeners of Naples find it more profitable to send their first fruits to St.
Petersburg than to furnish them to Florence and Rome.]
FOREIGN PLANTS, HOW INTRODUCED.
Besides the vegetables I have mentioned, we know that many plants of
smaller economical value have been the subjects of international exchange
in very recent times. Busbequius, Austrian ambassador at Constantinople
about the middle of the sixteenth century—whose letters contain one of the
best accounts of Turkish life which have appeared down to the present day
—brought home from the Ottoman capital the lilac and the tulip. The
Belgian Clusius about the same time introduced from the East the horse
chestnut, which has since wandered to America. The weeping willows of
Europe and the United States are said to have sprung from a slip received
from Smyrna by the poet Pope; and planted by him in an English garden;
Drouyn de l'IIuys, in a discourse delivered before the French Societe
d'Acclimatation, in 1860, claims for Rabelais the introduction of the melon,
the artichoke and the Alexandria pink into France; and the Portuguese
declare that the progenitor of all the European and American oranges was
an Oriental tree transplanted to Lisbon, and still living in the last
generation. [Footnote: The name portogallo, so generally applied to the
[Footnote: Many of these articles would undoubtedly have been made
known to the Greeks and Romans and have figured in their commerce, but
for the slowness and costliness of ancient navigation, which, in the seas
familiar to them, was suspended for a full third of the year from the
inability of their vessels to cope with winter weather. The present speed and
economy of transportation have wrought and are still working strange
commercial and industrial revolutions. Algeria now supplies Northern
Germany with fresh cauliflowers, and in the early spring the market-
gardeners of Naples find it more profitable to send their first fruits to St.
Petersburg than to furnish them to Florence and Rome.]
FOREIGN PLANTS, HOW INTRODUCED.
Besides the vegetables I have mentioned, we know that many plants of
smaller economical value have been the subjects of international exchange
in very recent times. Busbequius, Austrian ambassador at Constantinople
about the middle of the sixteenth century—whose letters contain one of the
best accounts of Turkish life which have appeared down to the present day
—brought home from the Ottoman capital the lilac and the tulip. The
Belgian Clusius about the same time introduced from the East the horse
chestnut, which has since wandered to America. The weeping willows of
Europe and the United States are said to have sprung from a slip received
from Smyrna by the poet Pope; and planted by him in an English garden;
Drouyn de l'IIuys, in a discourse delivered before the French Societe
d'Acclimatation, in 1860, claims for Rabelais the introduction of the melon,
the artichoke and the Alexandria pink into France; and the Portuguese
declare that the progenitor of all the European and American oranges was
an Oriental tree transplanted to Lisbon, and still living in the last
generation. [Footnote: The name portogallo, so generally applied to the
Page 109
orange in Italy, seems to favor this claim. The orange, however, was known
in Europe before the discovery of the Cape of Good Hope, and therefore,
before the establishment of direct relations between Portugal and the East.
—See Amari, Storia del Musulmani in Sicilia, vol ii., p. 445.
The date-palms of eastern and southern Spain were certainly introduced
by the Moors. Leo Von Rozmital, who visited Barcelona in 1476, says that
the date-tree grew in great abundance in the environs of that city and
ripened its fruit well. It is now scarcely cultivated further north than
Valencia. It is singular that Ritter in his very full monograph on the palm
does not mention those of Spain.
On the introduction of conifera into England see an interesting article in
the Edinburgh Review of October, 1864.
Muller, Das Buch der Pfianzenrodt, p. 86, asserts that in 1802 the
ancestor of all the mulberries in France, planted in 1500, was still standing
in a garden in the village of Allan-Montelimart.] The present favorite
flowers of the parterres of Europe have been imported from America, Japan
and other remote Oriental countries, within a century and a half, and, in
fine, there are few vegetables of any agricultural importance, few
ornamental trees or decorative plants, which are not now common to the
three civilized continents.
The statistics of vegetable emigration exhibit numerical results quite
surprising to those not familiar with the subject. The lonely island of St.
Helena is described as producing, at the time of its discovery in the year
1501, about sixty vegetable species, including some three or four known to
grow elsewhere also. [Footnote: It may be considered very highly probable,
if not certain, that the undiscriminating herbalists of the sixteenth century
must have overlooked many plants native to this island. An English
botanist, in an hour's visit to Aden, discovered several species of plants on
in Europe before the discovery of the Cape of Good Hope, and therefore,
before the establishment of direct relations between Portugal and the East.
—See Amari, Storia del Musulmani in Sicilia, vol ii., p. 445.
The date-palms of eastern and southern Spain were certainly introduced
by the Moors. Leo Von Rozmital, who visited Barcelona in 1476, says that
the date-tree grew in great abundance in the environs of that city and
ripened its fruit well. It is now scarcely cultivated further north than
Valencia. It is singular that Ritter in his very full monograph on the palm
does not mention those of Spain.
On the introduction of conifera into England see an interesting article in
the Edinburgh Review of October, 1864.
Muller, Das Buch der Pfianzenrodt, p. 86, asserts that in 1802 the
ancestor of all the mulberries in France, planted in 1500, was still standing
in a garden in the village of Allan-Montelimart.] The present favorite
flowers of the parterres of Europe have been imported from America, Japan
and other remote Oriental countries, within a century and a half, and, in
fine, there are few vegetables of any agricultural importance, few
ornamental trees or decorative plants, which are not now common to the
three civilized continents.
The statistics of vegetable emigration exhibit numerical results quite
surprising to those not familiar with the subject. The lonely island of St.
Helena is described as producing, at the time of its discovery in the year
1501, about sixty vegetable species, including some three or four known to
grow elsewhere also. [Footnote: It may be considered very highly probable,
if not certain, that the undiscriminating herbalists of the sixteenth century
must have overlooked many plants native to this island. An English
botanist, in an hour's visit to Aden, discovered several species of plants on
Page 110
rocks always reported, even by scientific travellers, as absolutely barren.
But after all, it appears to be well established that the original flora of St.
Helena was extremely limited, though now counting hundreds of species.]
At the present time its flora numbers seven hundred and fifty species—a
natural result of the position of the island as the half-way house on the great
ocean highway between Europe and the East. Humboldt and Bonpland
found, among the unquestionably indigenous plants of tropical America,
monocotyledons only, all the dicotyledons of those extensive regions
having been probably introduced after the colonization of the New World
by Spain.
The seven hundred new species which have found their way to St. Helena
within three centuries and a half, were certainly not all, or ever in the largest
proportion, designedly planted there by human art, and if we were well
acquainted with vegetable emigration, we should probably be able to show
that man has intentionally transferred fewer plants than he has accidentally
introduced into countries foreign to them. After the wheat, follow the tares
that infest it. The woods that grow among the cereal grains, the pests of the
kitchen garden, are the same in America as in Europe. [Footnote: Some
years ago I made a collection of weeds in the wheatfields of Upper Egypt,
and another in the gardens on the Bosphorus. Nearly all the plants were
identical with those which grow under the same conditions in New
England. I do not remember to have seen in America the scarlet wild poppy
so common in European grainfields. I have heard, however, that it has lately
crossed the Atlantic, and I am not sorry for it. With our abundant harvests of
wheat, we can well afford to pay now and then a loaf of bread for the
cheerful radiance of this brilliant flower.] The overturning of a wagon, or
any of the thousand accidents which befall the emigrant in his journey
across the Western plains, may scatter upon the ground the seeds he
designed for his garden, and the herbs which fill so important a place in the
rustic materia medica of the Eastern States, spring up along the prairie paths
But after all, it appears to be well established that the original flora of St.
Helena was extremely limited, though now counting hundreds of species.]
At the present time its flora numbers seven hundred and fifty species—a
natural result of the position of the island as the half-way house on the great
ocean highway between Europe and the East. Humboldt and Bonpland
found, among the unquestionably indigenous plants of tropical America,
monocotyledons only, all the dicotyledons of those extensive regions
having been probably introduced after the colonization of the New World
by Spain.
The seven hundred new species which have found their way to St. Helena
within three centuries and a half, were certainly not all, or ever in the largest
proportion, designedly planted there by human art, and if we were well
acquainted with vegetable emigration, we should probably be able to show
that man has intentionally transferred fewer plants than he has accidentally
introduced into countries foreign to them. After the wheat, follow the tares
that infest it. The woods that grow among the cereal grains, the pests of the
kitchen garden, are the same in America as in Europe. [Footnote: Some
years ago I made a collection of weeds in the wheatfields of Upper Egypt,
and another in the gardens on the Bosphorus. Nearly all the plants were
identical with those which grow under the same conditions in New
England. I do not remember to have seen in America the scarlet wild poppy
so common in European grainfields. I have heard, however, that it has lately
crossed the Atlantic, and I am not sorry for it. With our abundant harvests of
wheat, we can well afford to pay now and then a loaf of bread for the
cheerful radiance of this brilliant flower.] The overturning of a wagon, or
any of the thousand accidents which befall the emigrant in his journey
across the Western plains, may scatter upon the ground the seeds he
designed for his garden, and the herbs which fill so important a place in the
rustic materia medica of the Eastern States, spring up along the prairie paths
Page 111
but just opened by the caravan of the settler. [Footnote: Josselyn, who wrote
about fifty years after the foundation of the first British colony in New
England, says that the settlers at Plymouth had observed more than twenty
English plants springing up spontaneously near their improvements.
Every country has many plants not now, if ever, made use of by man, and
therefore not designedly propagated by him, but which cluster around his
dwelling, and continue to grow luxuriantly on the ruins of his rural
habitation after he has abandoned it. The site of a cottage, the very
foundation stones of which have been carried off, may often be recognized,
years afterwards, by the rank weeds which cover it, though no others of the
same species are found for miles.
"Mediaeval Catholicism," says Vaupell, "brought us the red horsehoof—
whose reddish-brown flower buds shoot up from the ground when the snow
melts, and are followed by the large leaves—comfrey and snake-root, which
grow only where there were convents and other dwellings in the Middle
Ages."—Bogens Indvandring & de Daneke Skove, pp. 1, 2. ]
Introduction of Foreign Plants.
"A negro slave of the great Cortez," says Humboldt, "was the first who
sowed wheat in New Spain. He found three grains of it among the rice
which had been brought from Spain as food for the soldiers."
About twenty years ago, a Japanese forage plant, the Lesperadeza striata,
whose seeds had been brought to the United States by some unknown
accident made its appearance in one of the Southern States. It spread
spontaneously in various directions, and in a few years was widely diffused.
It grows upon poor and exhausted soils, where the formation of a turf or
sward by the ordinary grasses would be impossible, and where
about fifty years after the foundation of the first British colony in New
England, says that the settlers at Plymouth had observed more than twenty
English plants springing up spontaneously near their improvements.
Every country has many plants not now, if ever, made use of by man, and
therefore not designedly propagated by him, but which cluster around his
dwelling, and continue to grow luxuriantly on the ruins of his rural
habitation after he has abandoned it. The site of a cottage, the very
foundation stones of which have been carried off, may often be recognized,
years afterwards, by the rank weeds which cover it, though no others of the
same species are found for miles.
"Mediaeval Catholicism," says Vaupell, "brought us the red horsehoof—
whose reddish-brown flower buds shoot up from the ground when the snow
melts, and are followed by the large leaves—comfrey and snake-root, which
grow only where there were convents and other dwellings in the Middle
Ages."—Bogens Indvandring & de Daneke Skove, pp. 1, 2. ]
Introduction of Foreign Plants.
"A negro slave of the great Cortez," says Humboldt, "was the first who
sowed wheat in New Spain. He found three grains of it among the rice
which had been brought from Spain as food for the soldiers."
About twenty years ago, a Japanese forage plant, the Lesperadeza striata,
whose seeds had been brought to the United States by some unknown
accident made its appearance in one of the Southern States. It spread
spontaneously in various directions, and in a few years was widely diffused.
It grows upon poor and exhausted soils, where the formation of a turf or
sward by the ordinary grasses would be impossible, and where
Page 112
consequently no regular pastures or meadows can exist. It makes excellent
fodder for stock, and though its value is contested, it is nevertheless
generally thought a very important addition to the agricultural resources of
the South. [Footnote: Accidents sometimes limit, as well as promote the
propagation of foreign vegetables in countries new to them. The Lombardy
poplar is a deciduous tree, and is very easily grown from cuttings. In most
of the countries into which it has been introduced the cuttings hare been
taken from the male, and as, consequently, males only have grown from
them, the poplar does not produce seed in those regions. This is a fortunate
circumstance, for otherwise this most worthless and least ornamental of
trees would spread with a rapidity that would make it an annoyance to the
agriculturist.]
In most of the Southern countries of Europe, the sheep and horned cattle
winter on the plains, but in the summer are driven, sometimes many days'
journey, to mountain pastures. Their coats and fleeces transport seeds in
both directions. Hence we see Alpine plants in champaign districts, the
plants of the plains on the borders of the glaciers, though in neither case do
these vegetables ripen their seeds and propagate themselves. This explains
the occurrence of tufts of common red clover with pallid and sickly flowers,
on the flanks of the Alps at heights exceeding seven thousand feet.
The hortus siccus of a botanist may accidentally sow seeds from the foot
of the Himalayas on the plains that skirt the Alps; and it is a fact of very
familiar observation, that exotics, transplanted to foreign climates suited to
their growth, often escape from the flower garden and naturalize themselves
among the spontaneous vegetation of the pastures. When the cases
containing the artistic treasures of Thorvaldsen wore opened in the court of
the museum where they are deposited, the straw and grass employed in
packing them were scattered upon the ground, and the next season there
sprang up from the seeds no less than twenty-five species of plants
fodder for stock, and though its value is contested, it is nevertheless
generally thought a very important addition to the agricultural resources of
the South. [Footnote: Accidents sometimes limit, as well as promote the
propagation of foreign vegetables in countries new to them. The Lombardy
poplar is a deciduous tree, and is very easily grown from cuttings. In most
of the countries into which it has been introduced the cuttings hare been
taken from the male, and as, consequently, males only have grown from
them, the poplar does not produce seed in those regions. This is a fortunate
circumstance, for otherwise this most worthless and least ornamental of
trees would spread with a rapidity that would make it an annoyance to the
agriculturist.]
In most of the Southern countries of Europe, the sheep and horned cattle
winter on the plains, but in the summer are driven, sometimes many days'
journey, to mountain pastures. Their coats and fleeces transport seeds in
both directions. Hence we see Alpine plants in champaign districts, the
plants of the plains on the borders of the glaciers, though in neither case do
these vegetables ripen their seeds and propagate themselves. This explains
the occurrence of tufts of common red clover with pallid and sickly flowers,
on the flanks of the Alps at heights exceeding seven thousand feet.
The hortus siccus of a botanist may accidentally sow seeds from the foot
of the Himalayas on the plains that skirt the Alps; and it is a fact of very
familiar observation, that exotics, transplanted to foreign climates suited to
their growth, often escape from the flower garden and naturalize themselves
among the spontaneous vegetation of the pastures. When the cases
containing the artistic treasures of Thorvaldsen wore opened in the court of
the museum where they are deposited, the straw and grass employed in
packing them were scattered upon the ground, and the next season there
sprang up from the seeds no less than twenty-five species of plants
Page 113
belonging to the Roman campagna, some of which were preserved and
cultivated as a new tribute to the memory of the great Scandinavian
sculptor, and at least four are said to have spontaneously naturalized
themselves about Copenhagen. [Footnote: Vaupell, Bogens Indvandring i de
Danske Skove, p. 2.]
The Turkish armies, in their incursions into Europe, brought Eastern
vegetables in their train, and left the seeds of Oriental wall plants to grow
upon the ramparts of Buda and Vienna. [Footnote: I believe it is certain that
the Turks introduced tobacco into Hungary, and probable that they in some
measure compensated, the injury by introducing maize also, which, as well
as tobacco, has been claimed as Hungarian by patriotic Magyars.]
In the campaign of 1814, the Russian troops brought, in the stuffing of
their saddles and by other accidental means, seeds from the banks of the
Dnieper to the valley of the Rhine, and even introduced the plants of the
steppes into the environs of Paris.
The forage imported for the French army in the war of 1870-1871 has
introduced numerous plants from Northern Africa and other countries into
France, and this vegetable emigration is so extensive and so varied in
character, that it will probably have an important botanical, and even
economical, effect on the flora of that country. [Footnote: In a
communication lately made to the French Academy, M. Vibraye gives
numerous interesting details on this subject, and says the appearance of the
many new plants observed in France in 1871, "results from forage supplied
from abroad, the seeds of which had fallen upon the ground. At the present
time, several Mediterranean plants, chiefly Algerian, having braved the cold
of an exceptionally severe winter, are being largely propagated, forming
extensive meadows, and changing soil that was formerly arid and produced
no vegetable of importance into veritable oases." See Nature, Aug. 1, 1872,
cultivated as a new tribute to the memory of the great Scandinavian
sculptor, and at least four are said to have spontaneously naturalized
themselves about Copenhagen. [Footnote: Vaupell, Bogens Indvandring i de
Danske Skove, p. 2.]
The Turkish armies, in their incursions into Europe, brought Eastern
vegetables in their train, and left the seeds of Oriental wall plants to grow
upon the ramparts of Buda and Vienna. [Footnote: I believe it is certain that
the Turks introduced tobacco into Hungary, and probable that they in some
measure compensated, the injury by introducing maize also, which, as well
as tobacco, has been claimed as Hungarian by patriotic Magyars.]
In the campaign of 1814, the Russian troops brought, in the stuffing of
their saddles and by other accidental means, seeds from the banks of the
Dnieper to the valley of the Rhine, and even introduced the plants of the
steppes into the environs of Paris.
The forage imported for the French army in the war of 1870-1871 has
introduced numerous plants from Northern Africa and other countries into
France, and this vegetable emigration is so extensive and so varied in
character, that it will probably have an important botanical, and even
economical, effect on the flora of that country. [Footnote: In a
communication lately made to the French Academy, M. Vibraye gives
numerous interesting details on this subject, and says the appearance of the
many new plants observed in France in 1871, "results from forage supplied
from abroad, the seeds of which had fallen upon the ground. At the present
time, several Mediterranean plants, chiefly Algerian, having braved the cold
of an exceptionally severe winter, are being largely propagated, forming
extensive meadows, and changing soil that was formerly arid and produced
no vegetable of importance into veritable oases." See Nature, Aug. 1, 1872,
Page 114
p. 263. We shall see on a following page that canals are efficient agencies in
the unintentional interchange of organic life, vegetable as well as animal,
between regions connected by such channels.]
The Canada thistle, Erigeron Canadense, which is said to have
accompanied the early French voyagers to Canada from Normandy, is
reported to have been introduced into other parts of Europe two hundred
years ago by a seed which dropped out of the stuffed skin of an American
bird.
VEGETABLE POWER OF ACCOMMODATION.
The vegetables which, so far as we know their history, seem to have been
longest objects of human care, can, by painstaking industry, be made to
grow under a great variety of circumstances, and some of them prosper
nearly equally well when planted and tended on soils of almost any
geological character; but the seeds of most of them vegetate only in
artificially prepared ground, they have little self-sustaining power, and they
soon perish when the nursing hand of man is withdrawn from them.
The vine genus is very catholic and cosmopolite in its habits, but
particular varieties are extremely fastidious and exclusive in their
requirements as to soil and climate. The stocks of many celebrated
vineyards lose their peculiar qualities by transplantation, and the most
famous wines are capable of production only in certain well-defined and for
the most part narrow districts. The Ionian vine which bears the little
stoneless grape known in commerce as the Zante currant, has resisted
almost all efforts to naturalize it elsewhere, and is scarcely grown except in
two or three of the Ionian islands and in a narrow territory on the northern
shores of the Morea.
the unintentional interchange of organic life, vegetable as well as animal,
between regions connected by such channels.]
The Canada thistle, Erigeron Canadense, which is said to have
accompanied the early French voyagers to Canada from Normandy, is
reported to have been introduced into other parts of Europe two hundred
years ago by a seed which dropped out of the stuffed skin of an American
bird.
VEGETABLE POWER OF ACCOMMODATION.
The vegetables which, so far as we know their history, seem to have been
longest objects of human care, can, by painstaking industry, be made to
grow under a great variety of circumstances, and some of them prosper
nearly equally well when planted and tended on soils of almost any
geological character; but the seeds of most of them vegetate only in
artificially prepared ground, they have little self-sustaining power, and they
soon perish when the nursing hand of man is withdrawn from them.
The vine genus is very catholic and cosmopolite in its habits, but
particular varieties are extremely fastidious and exclusive in their
requirements as to soil and climate. The stocks of many celebrated
vineyards lose their peculiar qualities by transplantation, and the most
famous wines are capable of production only in certain well-defined and for
the most part narrow districts. The Ionian vine which bears the little
stoneless grape known in commerce as the Zante currant, has resisted
almost all efforts to naturalize it elsewhere, and is scarcely grown except in
two or three of the Ionian islands and in a narrow territory on the northern
shores of the Morea.
Page 115
The attempts to introduce European varieties of the vine into the United
States have not been successful except in California, [Footnote: In 1869, a
vine of a European variety planted in Sta. Barbara county in 1833 measured
a foot in diameter four foot above the ground. Its ramifications covered ten
thousand square feet of surface and it annually produces twelve thousand
pounds of grapes. The bunches are sixteen or eighteen inches long, and
weigh six or seven pounds.-Letter from Commissioner of Land-Office,
dated May 13, 1860.] and it may be stated as a general rule that European
forest and ornamental trees are not suited to the climate of North America,
and that, at the same time, American garden vegetables are less luxuriant,
productive and tasteful in Europe than in the United States.
The saline atmosphere of the sea is specially injurious both to seeds and
to very many young plants, and it is only recently that the transportation of
some very important vegetables across the ocean lines been made
practicable, through the invention of Ward's air-tight glass cases. By this
means large numbers of the trees which produce the Jesuit's bark were
successfully transplanted from America to the British possessions in the
East, where this valuable plant may now be said to have become fully
naturalized. [Footnote: See Cleghorn, Forests and Gardens of South India,
Edinburgh, 1861, and The British Parliamentary return on the Chinchona
Plant, 1866. It has been found that the seeds of several species of
CINCHONA preserve their vitality long enough to be transported to distant
regions. The swiftness of steam navigation render it possible to transport to
foreign countries not only seeds but delicate living plants which could not
have borne a long voyage by sailing vessels.]
Vegetables, naturalized abroad either by accident or design, sometimes
exhibit a greatly increased luxuriance of growth.
States have not been successful except in California, [Footnote: In 1869, a
vine of a European variety planted in Sta. Barbara county in 1833 measured
a foot in diameter four foot above the ground. Its ramifications covered ten
thousand square feet of surface and it annually produces twelve thousand
pounds of grapes. The bunches are sixteen or eighteen inches long, and
weigh six or seven pounds.-Letter from Commissioner of Land-Office,
dated May 13, 1860.] and it may be stated as a general rule that European
forest and ornamental trees are not suited to the climate of North America,
and that, at the same time, American garden vegetables are less luxuriant,
productive and tasteful in Europe than in the United States.
The saline atmosphere of the sea is specially injurious both to seeds and
to very many young plants, and it is only recently that the transportation of
some very important vegetables across the ocean lines been made
practicable, through the invention of Ward's air-tight glass cases. By this
means large numbers of the trees which produce the Jesuit's bark were
successfully transplanted from America to the British possessions in the
East, where this valuable plant may now be said to have become fully
naturalized. [Footnote: See Cleghorn, Forests and Gardens of South India,
Edinburgh, 1861, and The British Parliamentary return on the Chinchona
Plant, 1866. It has been found that the seeds of several species of
CINCHONA preserve their vitality long enough to be transported to distant
regions. The swiftness of steam navigation render it possible to transport to
foreign countries not only seeds but delicate living plants which could not
have borne a long voyage by sailing vessels.]
Vegetables, naturalized abroad either by accident or design, sometimes
exhibit a greatly increased luxuriance of growth.
Page 116
The European cardoon, an esculent thistle, has broken out from the
gardens of the Spanish colonies on the La Plata, acquired a gigantic stature,
and propagated itself, in impenetrable thickets, over hundreds of leagues of
the Pampas; and the Anacharis alsinastrum, a water plant not much inclined
to spread in its native American habitat, has found its way into English
rivers, and extended itself to such a degree as to form a serious obstruction
to the flow of the current, and even to navigation.
Not only do many wild plants exhibit a remarkable facility of
accommodation, but their seeds usually possess great tenacity of life, and
their germinating power resists very severe trials. Hence, while the seeds of
many cultivated vegetables lose their vitality in two or three years, and can
be transported safely to distant countries only with great precautions, the
weeds that infest those vegetables, though not cared for by man, continue to
accompany him in his migrations, and find a new home on every soil he
colonizes. Nature fights in defence of her free children, but wars upon them
when they have deserted her banners and tamely submitted to the
domination of man. [Footnote: Tempests, violent enough to destroy all
cultivated plants, frequently spare those of spontaneous growth. I have
often seen in Northern Italy, vineyards, maize fields, mulberry and fruit
trees completely stripped of their foliage by hail, while the forest trees
scattered through the meadows, and the shrubs and brambles which sprang
up by the wayslde, passed through the ordeal with scarcely the loss of a
leaflet.]
Indeed, the faculty of spontaneous reproduction and perpetuation
necessarily supposes a greater power of accommodation, within a certain
range, than we find in most domesticated plants, for it would rarely happen
that the seed of a wild plant would fall into ground as nearly similar, in
composition and condition, to that where its parent grew, as the soils of
different fields artificially prepared for growing a particular vegetable are to
gardens of the Spanish colonies on the La Plata, acquired a gigantic stature,
and propagated itself, in impenetrable thickets, over hundreds of leagues of
the Pampas; and the Anacharis alsinastrum, a water plant not much inclined
to spread in its native American habitat, has found its way into English
rivers, and extended itself to such a degree as to form a serious obstruction
to the flow of the current, and even to navigation.
Not only do many wild plants exhibit a remarkable facility of
accommodation, but their seeds usually possess great tenacity of life, and
their germinating power resists very severe trials. Hence, while the seeds of
many cultivated vegetables lose their vitality in two or three years, and can
be transported safely to distant countries only with great precautions, the
weeds that infest those vegetables, though not cared for by man, continue to
accompany him in his migrations, and find a new home on every soil he
colonizes. Nature fights in defence of her free children, but wars upon them
when they have deserted her banners and tamely submitted to the
domination of man. [Footnote: Tempests, violent enough to destroy all
cultivated plants, frequently spare those of spontaneous growth. I have
often seen in Northern Italy, vineyards, maize fields, mulberry and fruit
trees completely stripped of their foliage by hail, while the forest trees
scattered through the meadows, and the shrubs and brambles which sprang
up by the wayslde, passed through the ordeal with scarcely the loss of a
leaflet.]
Indeed, the faculty of spontaneous reproduction and perpetuation
necessarily supposes a greater power of accommodation, within a certain
range, than we find in most domesticated plants, for it would rarely happen
that the seed of a wild plant would fall into ground as nearly similar, in
composition and condition, to that where its parent grew, as the soils of
different fields artificially prepared for growing a particular vegetable are to
Page 117
each other. Accordingly, though every wild species affects a habitat of a
particular character, it is found that, if accidentally or designedly sown
elsewhere, it will grow under conditions extremely unlike those of its
birthplace. Cooper says: "We cannot say positively that any plant is
uncultivable ANYWHERE until it has been tried;" and this seems to be
even more true of wild than of domesticated vegetation.
The wild plant is much hardier than the domesticated vegetable, and the
same law prevails in animated brute and even human life. The beasts of the
chase are more capable of endurance and privation and more tenacious of
life, than the domesticated animals which most nearly resemble them. The
savage fights on, after he has received half a dozen mortal wounds, the least
of which would have instantly paralyzed the strength of his civilized enemy,
and, like the wild boar, he has been known to press forward along the shaft
of the spear which was trans-piercing his vitals, and to deal a deathblow on
the soldier who wielded it.
True, domesticated plants can be gradually acclimatized to bear a degree
of heat or of cold, which, in their wild state, they would not have supported;
the trained English racer out-strips the swiftest horse of the pampas or
prairies, perhaps even the less systematically educated courser of the Arab;
the strength of the European, as tested by the dynamometer, is greater than
that of the New Zealander. But all these are instances of excessive
development of particular capacities and faculties at the expense of general
vital power. Expose untamed and domesticated forms of life, together, to an
entire set of physical conditions equally alien to the former habits of both,
so that every power of resistance and accommodation shall be called into
action, and the wild plant or animal will live, while the domesticated will
perish.
AGRICULTURAL PRODUCTS OF THE UNITED STATES.
particular character, it is found that, if accidentally or designedly sown
elsewhere, it will grow under conditions extremely unlike those of its
birthplace. Cooper says: "We cannot say positively that any plant is
uncultivable ANYWHERE until it has been tried;" and this seems to be
even more true of wild than of domesticated vegetation.
The wild plant is much hardier than the domesticated vegetable, and the
same law prevails in animated brute and even human life. The beasts of the
chase are more capable of endurance and privation and more tenacious of
life, than the domesticated animals which most nearly resemble them. The
savage fights on, after he has received half a dozen mortal wounds, the least
of which would have instantly paralyzed the strength of his civilized enemy,
and, like the wild boar, he has been known to press forward along the shaft
of the spear which was trans-piercing his vitals, and to deal a deathblow on
the soldier who wielded it.
True, domesticated plants can be gradually acclimatized to bear a degree
of heat or of cold, which, in their wild state, they would not have supported;
the trained English racer out-strips the swiftest horse of the pampas or
prairies, perhaps even the less systematically educated courser of the Arab;
the strength of the European, as tested by the dynamometer, is greater than
that of the New Zealander. But all these are instances of excessive
development of particular capacities and faculties at the expense of general
vital power. Expose untamed and domesticated forms of life, together, to an
entire set of physical conditions equally alien to the former habits of both,
so that every power of resistance and accommodation shall be called into
action, and the wild plant or animal will live, while the domesticated will
perish.
AGRICULTURAL PRODUCTS OF THE UNITED STATES.
Page 118
According to the census of 1870, the United States had, on the first of June
in that year, in round numbers, 189,000,000 acres of improved land, the
quantity having been increased by 16,000,000 acres within the ten years
next preceding. [Footnote: Ninth Census of the United States, 1872, p. 841.
By "improved" land, in the reports on the census of the United States, is
meant "cleared land" used for grazing, grass, or tillage, or which is now
fallow, connected with or belonging to a farm."—Instructions to Marshals
and Assistants, Census of 1870.] Not to mention less important crops, this
land produced, in the year ending on the day last mentioned, in round
numbers, 288,000,000 bushels of wheat, 17,000,000 bushels of rye,
282,000,000 bushels of oats, 6,000,000 bushels of peas and beans,
30,000,000 bushels of barley, orchard fruits to the value of $47,000,000,
640,000 bushels of cloverseed, 580,000 bushels of other grass seed, 13,000
tons of hemp, 27,000,000 pounds of flax, and 1,730,000 bushels of
flaxseed. These vegetable growths were familiar to ancient European
agriculture, but they were all introduced into North America after the close
of the sixteenth century.
Of the fruits of agricultural industry unknown to the Greeks and Romans,
or too little employed by them to be of any commercial importance, the
United States produced, in the same year, 74,000,000 pounds of rice,
10,000,000 bushels of buckwheat, 3,000,000 bales of cotton, [Footnote:
Cotton, though cultivated in Asia from the remotest antiquity, and known as
a rare and costly product to the Latins and the Greeks, was not used by
them except as an article of luxury, nor did it enter into their commerce to
any considerable extent as a regular object of importation. The early
voyagers found it in common use in the West Indies and in the provinces
first colonized by the Spaniards; but it was introduced into the territory of
the United States by European settlers, and did not become of any
importance until after the Revolution. Cottonseed was sown in Virginia as
early as 1621, but was not cultivated with a view to profit for more than a
in that year, in round numbers, 189,000,000 acres of improved land, the
quantity having been increased by 16,000,000 acres within the ten years
next preceding. [Footnote: Ninth Census of the United States, 1872, p. 841.
By "improved" land, in the reports on the census of the United States, is
meant "cleared land" used for grazing, grass, or tillage, or which is now
fallow, connected with or belonging to a farm."—Instructions to Marshals
and Assistants, Census of 1870.] Not to mention less important crops, this
land produced, in the year ending on the day last mentioned, in round
numbers, 288,000,000 bushels of wheat, 17,000,000 bushels of rye,
282,000,000 bushels of oats, 6,000,000 bushels of peas and beans,
30,000,000 bushels of barley, orchard fruits to the value of $47,000,000,
640,000 bushels of cloverseed, 580,000 bushels of other grass seed, 13,000
tons of hemp, 27,000,000 pounds of flax, and 1,730,000 bushels of
flaxseed. These vegetable growths were familiar to ancient European
agriculture, but they were all introduced into North America after the close
of the sixteenth century.
Of the fruits of agricultural industry unknown to the Greeks and Romans,
or too little employed by them to be of any commercial importance, the
United States produced, in the same year, 74,000,000 pounds of rice,
10,000,000 bushels of buckwheat, 3,000,000 bales of cotton, [Footnote:
Cotton, though cultivated in Asia from the remotest antiquity, and known as
a rare and costly product to the Latins and the Greeks, was not used by
them except as an article of luxury, nor did it enter into their commerce to
any considerable extent as a regular object of importation. The early
voyagers found it in common use in the West Indies and in the provinces
first colonized by the Spaniards; but it was introduced into the territory of
the United States by European settlers, and did not become of any
importance until after the Revolution. Cottonseed was sown in Virginia as
early as 1621, but was not cultivated with a view to profit for more than a
Page 119
century afterwards. Sea-island cotton was first grown on the coast of
Georgia in 1786, the seed having been brought from the Bahamas, when it
had been introduced from Anguilla—BIGELOW, Les Etats-Unis en 1868,
p. 370]. 87,000 hogsheads of cane sugar, 6,600,000 gallons of cane
molasses, 16,000,000 gallons of sorghum molasses, all yielded by
vegetables introduced into that country within two hundred years, and—
with the exception of buckwheat, the origin of which is uncertain, and of
cotton—all, directly or indirectly, from the East Indies; besides, from
indigenous plants unknown to ancient agriculture, 761,000,000 bushels of
Indian corn, 263,000,000 pounds of tobacco, 143,000,000 bushels of
potatoes, 22,000,000 bushels of sweet potatoes, 28,000,000 pounds of
maple sugar, and 925,000 gallons of maple molasses. [Footnote: There is a
falling off since 1860 of 11,000,000 pounds in the quantity of maple sugar
and of more than a million gallons of maple molasses. The high price of
cane sugar during and since the late civil war must have increased the
product of maple sugar and molasses beyond what it otherwise would have
been, but the domestic warfare on the woods has more than compensated
this cause of increase.] To all this we are to add 27,000,000 tons of hay,—
produced partly by new, partly by long known, partly by exotic and partly
by native herbs and grasses, the value of $21,000,000 in garden vegetables
chiefly of European or Asiatic origin, 3,000,000 gallons of wine, and many
minor agricultural products. [Footnote: Raenie, Bochmeria tenacissima, a
species of Chinese nettle producing a fibre which may be spun and woven,
and which unites many of the properties of silk and of linen, has been
completely naturalized in the United States, and results important to the
industry of the country are expected from it.]
The weight of this harvest of a year would be many times the tonnage of
all the shipping of the United States at the close of the year 1870—and,
with the exception of the maple sugar, the maple molasses, and the products
of the Western prairie lands and of some small Indian clearings, it was all
Georgia in 1786, the seed having been brought from the Bahamas, when it
had been introduced from Anguilla—BIGELOW, Les Etats-Unis en 1868,
p. 370]. 87,000 hogsheads of cane sugar, 6,600,000 gallons of cane
molasses, 16,000,000 gallons of sorghum molasses, all yielded by
vegetables introduced into that country within two hundred years, and—
with the exception of buckwheat, the origin of which is uncertain, and of
cotton—all, directly or indirectly, from the East Indies; besides, from
indigenous plants unknown to ancient agriculture, 761,000,000 bushels of
Indian corn, 263,000,000 pounds of tobacco, 143,000,000 bushels of
potatoes, 22,000,000 bushels of sweet potatoes, 28,000,000 pounds of
maple sugar, and 925,000 gallons of maple molasses. [Footnote: There is a
falling off since 1860 of 11,000,000 pounds in the quantity of maple sugar
and of more than a million gallons of maple molasses. The high price of
cane sugar during and since the late civil war must have increased the
product of maple sugar and molasses beyond what it otherwise would have
been, but the domestic warfare on the woods has more than compensated
this cause of increase.] To all this we are to add 27,000,000 tons of hay,—
produced partly by new, partly by long known, partly by exotic and partly
by native herbs and grasses, the value of $21,000,000 in garden vegetables
chiefly of European or Asiatic origin, 3,000,000 gallons of wine, and many
minor agricultural products. [Footnote: Raenie, Bochmeria tenacissima, a
species of Chinese nettle producing a fibre which may be spun and woven,
and which unites many of the properties of silk and of linen, has been
completely naturalized in the United States, and results important to the
industry of the country are expected from it.]
The weight of this harvest of a year would be many times the tonnage of
all the shipping of the United States at the close of the year 1870—and,
with the exception of the maple sugar, the maple molasses, and the products
of the Western prairie lands and of some small Indian clearings, it was all
Page 120
grown upon lands wrested from the forest by the European race within little
more than two hundred years. The wants of Europe have introduced into the
colonies of tropical America the sugar cane, [Footnote: The sugar cane was
introduced by the Arabs into Sicily and Spain as early as the ninth century,
and though it is now scarcely grown in those localities, I am not aware of
any reason to doubt that its cultivation might be revived with advantage.
From Spain it was carried to the West Indies, though different varieties have
since been introduced into those Islands from other sources.] the coffee
plant, the orange and the lemon, all of Oriental origin, have immensely
stimulated the cultivation of the former two in the countries of which they
are natives, and, of course, promoted agricultural operations which must
have affected the geography of those regions to an extent proportionate to
the scale on which they have been pursued.
USEFUL AMERICAN PLANTS GROWN IN EUROPE.
America has partially repaid her debt to the Eastern continent. Maize and
the potato are very valuable additions to the field agriculture of Europe and
the East, and the tomato is no mean gift to the kitchen gardens of the Old
World, though certainly not an adequate return for the multitude of esculent
roots and leguminous plants which the European colonists carried with
them. [Footnote: John Smith mentions, In his Historie of Virginia, 1624,
pease and beans as having been cultivated by the natives before the arrival
of the whites, and there is no doubt, I believe, that several common
cucurbitaceous plants are of American origin; but most, if not all the
varieties of pease, beans, and other pod fruits now grown in American
gardens, are from European and other foreign seed.
Cartier, A.D. 1535-'6, mentions "vines, great melons, cucumbers, gourds
[courges], pease, beans of various colors, but not like ours," as common
more than two hundred years. The wants of Europe have introduced into the
colonies of tropical America the sugar cane, [Footnote: The sugar cane was
introduced by the Arabs into Sicily and Spain as early as the ninth century,
and though it is now scarcely grown in those localities, I am not aware of
any reason to doubt that its cultivation might be revived with advantage.
From Spain it was carried to the West Indies, though different varieties have
since been introduced into those Islands from other sources.] the coffee
plant, the orange and the lemon, all of Oriental origin, have immensely
stimulated the cultivation of the former two in the countries of which they
are natives, and, of course, promoted agricultural operations which must
have affected the geography of those regions to an extent proportionate to
the scale on which they have been pursued.
USEFUL AMERICAN PLANTS GROWN IN EUROPE.
America has partially repaid her debt to the Eastern continent. Maize and
the potato are very valuable additions to the field agriculture of Europe and
the East, and the tomato is no mean gift to the kitchen gardens of the Old
World, though certainly not an adequate return for the multitude of esculent
roots and leguminous plants which the European colonists carried with
them. [Footnote: John Smith mentions, In his Historie of Virginia, 1624,
pease and beans as having been cultivated by the natives before the arrival
of the whites, and there is no doubt, I believe, that several common
cucurbitaceous plants are of American origin; but most, if not all the
varieties of pease, beans, and other pod fruits now grown in American
gardens, are from European and other foreign seed.
Cartier, A.D. 1535-'6, mentions "vines, great melons, cucumbers, gourds
[courges], pease, beans of various colors, but not like ours," as common
Page 121
among the Indians of the banks of the St. Lawrence—Bref Recit, etc.,
reprint. Paris, 1863, pp. 13, a; 14, b; 20, b; 31, a.] I wish I could believe,
with some, that America is not alone responsible for the introduction of the
filthy weed, tobacco, the use of which is the most vulgar and pernicious
habit engrafted by the semi-barbarism of modern civilization upon the less
multifarious sensualism of ancient life; but the alleged occurrence of pipe-
like objects in old Sclavonic, and, it has been said, in Hungarian sepulchres,
is hardly sufficient evidence to convict those races of complicity in this
grave offence against the temperance and the refinement of modern society.
EXTIRPATION OF VEGETABLES.
Lamentable as are the evils produced by the too general felling of the
woods in the Old World, I believe it does not appear that any species of
native forest tree has yet been extirpated by man on the Eastern continent.
The roots, stumps, trunks, and foliage found in bogs are recognized as
belonging to still extant species. Except in some few cases where there is
historical evidence that foreign material was employed, the timber of the
oldest European buildings, and even of the lacustrine habitations of
Switzerland, is evidently the product of trees still common in or near the
countries where such architectural remains are found; nor have the Egyptian
catacombs themselves revealed to us the former existence of any woods not
now familiar to us as the growth of still living trees. [Footnote: Some
botanists think that a species of water lily represented in many Egyptian
tombs has become extinct, and the papyrus, which must have once been
abundant in Egypt, is now found only in a very few localities near the
mouth of the Nile. It grows very well and ripens its seeds in the waters of
the Anapus near Syracuse, and I have seen it in garden ponds at Messina
and in Malta. There is no apparent reason for believing that it could not be
reprint. Paris, 1863, pp. 13, a; 14, b; 20, b; 31, a.] I wish I could believe,
with some, that America is not alone responsible for the introduction of the
filthy weed, tobacco, the use of which is the most vulgar and pernicious
habit engrafted by the semi-barbarism of modern civilization upon the less
multifarious sensualism of ancient life; but the alleged occurrence of pipe-
like objects in old Sclavonic, and, it has been said, in Hungarian sepulchres,
is hardly sufficient evidence to convict those races of complicity in this
grave offence against the temperance and the refinement of modern society.
EXTIRPATION OF VEGETABLES.
Lamentable as are the evils produced by the too general felling of the
woods in the Old World, I believe it does not appear that any species of
native forest tree has yet been extirpated by man on the Eastern continent.
The roots, stumps, trunks, and foliage found in bogs are recognized as
belonging to still extant species. Except in some few cases where there is
historical evidence that foreign material was employed, the timber of the
oldest European buildings, and even of the lacustrine habitations of
Switzerland, is evidently the product of trees still common in or near the
countries where such architectural remains are found; nor have the Egyptian
catacombs themselves revealed to us the former existence of any woods not
now familiar to us as the growth of still living trees. [Footnote: Some
botanists think that a species of water lily represented in many Egyptian
tombs has become extinct, and the papyrus, which must have once been
abundant in Egypt, is now found only in a very few localities near the
mouth of the Nile. It grows very well and ripens its seeds in the waters of
the Anapus near Syracuse, and I have seen it in garden ponds at Messina
and in Malta. There is no apparent reason for believing that it could not be
Page 122
easily cultivated in Egypt, to any extent, if there were any special motive
for encouraging its growth.
for encouraging its growth.
Page 123
Silphium, a famous medicinal plant of Lybia and of Persia, seems to have
disappeared entirely. At any rate there is no proof that it now exists in either
of those regions. The Silphium of Greek and Roman commerce appears to
have come wholly from Cyrene, that from the Asiatic deserts being
generally of less value, or, as Strabo says, perhaps of an inferior variety.
The province near Cyrene which produced it was very limited, and
according to Strabo (ed. Casaubon, p. 837), it was at one time almost
entirely extirpated by the nomade Africans who invaded the province and
rooted out the plant.
The vegetable which produced the Balm of Gilead has not been found in
modern times, although the localities in which it anciently grew have been
carefully explored.] It is, however, said that the yew tree, Taxus baccata,
formerly very common in England, Germany, and—as we are authorized to
infer from Theophrastus—in Greece, has almost wholly disappeared from
the latter country, and seems to be dying out in Germany. The wood of the
yew surpasses that of almost any other European tree in closeness and
fineness of grain, and it is well known for the elasticity which of old made
it so great a favorite with the English archer. It is much in request among
wood carvers and turners, and the demand for it explains, in part, its
increasing scarcity.
It is also asserted that no insect depends upon it for food or shelter, or
aids in its fructification, and birds very rarely feed upon its berries: these
are circumstances of no small importance, because the tree hence wants
means of propagation or diffusion common to so many other plants. But it
is alleged that the reproductive power of the yew is exhausted, and that it
can no longer be readily propagated by the natural sowing of its seeds, or by
artificial methods. If further investigation and careful experiment should
establish this fact, it will go far to show that a climatic change, of a
disappeared entirely. At any rate there is no proof that it now exists in either
of those regions. The Silphium of Greek and Roman commerce appears to
have come wholly from Cyrene, that from the Asiatic deserts being
generally of less value, or, as Strabo says, perhaps of an inferior variety.
The province near Cyrene which produced it was very limited, and
according to Strabo (ed. Casaubon, p. 837), it was at one time almost
entirely extirpated by the nomade Africans who invaded the province and
rooted out the plant.
The vegetable which produced the Balm of Gilead has not been found in
modern times, although the localities in which it anciently grew have been
carefully explored.] It is, however, said that the yew tree, Taxus baccata,
formerly very common in England, Germany, and—as we are authorized to
infer from Theophrastus—in Greece, has almost wholly disappeared from
the latter country, and seems to be dying out in Germany. The wood of the
yew surpasses that of almost any other European tree in closeness and
fineness of grain, and it is well known for the elasticity which of old made
it so great a favorite with the English archer. It is much in request among
wood carvers and turners, and the demand for it explains, in part, its
increasing scarcity.
It is also asserted that no insect depends upon it for food or shelter, or
aids in its fructification, and birds very rarely feed upon its berries: these
are circumstances of no small importance, because the tree hence wants
means of propagation or diffusion common to so many other plants. But it
is alleged that the reproductive power of the yew is exhausted, and that it
can no longer be readily propagated by the natural sowing of its seeds, or by
artificial methods. If further investigation and careful experiment should
establish this fact, it will go far to show that a climatic change, of a
Page 124
character unfavorable to the growth of the yew, has really taken place in
Germany, though not yet proved by instrumental observation, and the most
probable cause of such change would be found in the diminution of the area
covered by the forests. The industry of man is said to have been so
successful in the local extirpation of noxious or useless vegetables in China,
that, with the exception of a few water plants in the rice grounds, it is
sometimes impossible to find a single weed in an extensive district; and the
late eminent agriculturist, Mr. Coke, is reported to have offered in vain a
considerable reward for the detection of a weed in a large wheatfield on his
estate in England. In these cases, however, there is no reason to suppose
that diligent husbandry has done more than to eradicate the pests of
agriculture within a comparatively limited area, and the cockle and the
darnel will probably remain to plague the slovenly cultivator as long as the
cereal grains continue to bless him. [Footnote: Although it is not known that
man has absolutely extirpated any vegetable, the mysterious diseases which
have, for the last twenty years, so injuriously affected the potato, the vine,
the orange, the olive, and silk husbandry, are ascribed by some to a climatic
deterioration produced by excessive destruction of the woods. As will be
seen in the next chapter, a retardation in the period of spring has been
observed in numerous localities in Southern Europe, as well as in the
United States, and this change has been thought to favor the multiplication
of the obscure parasites which causee the injury to the vegetables
mentioned. Babinet supposes the parasites which attack the grape and the
potato to be animal, not vegetable, and he ascribes their multiplication to
excessive manuring and stimulation of the growth of the plants on which
they live. They are now generally, it not universally, regarded as vegetable,
and if they are so, Babinet's theory would be even more plausible than on
his own supposition.—Etudes et lectures, ii, p. 269.
It is a fact of some interest in agricultural economy, that the oidium,
which is so destructive to the grape, has produced no pecuniary loss to the
Germany, though not yet proved by instrumental observation, and the most
probable cause of such change would be found in the diminution of the area
covered by the forests. The industry of man is said to have been so
successful in the local extirpation of noxious or useless vegetables in China,
that, with the exception of a few water plants in the rice grounds, it is
sometimes impossible to find a single weed in an extensive district; and the
late eminent agriculturist, Mr. Coke, is reported to have offered in vain a
considerable reward for the detection of a weed in a large wheatfield on his
estate in England. In these cases, however, there is no reason to suppose
that diligent husbandry has done more than to eradicate the pests of
agriculture within a comparatively limited area, and the cockle and the
darnel will probably remain to plague the slovenly cultivator as long as the
cereal grains continue to bless him. [Footnote: Although it is not known that
man has absolutely extirpated any vegetable, the mysterious diseases which
have, for the last twenty years, so injuriously affected the potato, the vine,
the orange, the olive, and silk husbandry, are ascribed by some to a climatic
deterioration produced by excessive destruction of the woods. As will be
seen in the next chapter, a retardation in the period of spring has been
observed in numerous localities in Southern Europe, as well as in the
United States, and this change has been thought to favor the multiplication
of the obscure parasites which causee the injury to the vegetables
mentioned. Babinet supposes the parasites which attack the grape and the
potato to be animal, not vegetable, and he ascribes their multiplication to
excessive manuring and stimulation of the growth of the plants on which
they live. They are now generally, it not universally, regarded as vegetable,
and if they are so, Babinet's theory would be even more plausible than on
his own supposition.—Etudes et lectures, ii, p. 269.
It is a fact of some interest in agricultural economy, that the oidium,
which is so destructive to the grape, has produced no pecuniary loss to the
Page 125
proprietors of the vineyards in France. "The price of wine," says Lavergne,
"has quintupled, and as the product of the vintage has not diminished in the
same proportion, the crisis has been, on the whole, rather advantageous than
detrimental to the country."—Economie rurale de la France, pp. 263, 264.
France produces a large surplus of wines for exportation, and the sales to
foreign consumers are the principal source of profit to French vinegrowers.
In Northern Italy, on the contrary, which exports little wine, there has been
no such increase in the price of wine as to compensate the great diminution
in the yield of the vines, and the loss of this harvest is severely felt. In
Sicily, however, which exports much wine, prices have risen as rapidly as in
France. Waltershausen informs us that in the years 1838-'42, the red wine of
Mount Etna sold at the rate of one kreuzer and a half, or one cent the bottle,
and sometimes even at but two thirds that price, but that at present it
commands five or six times as much.
The grape disease has operated severely on small cultivators whose
vineyards only furnished a supply for domestic use, but Sicily has received
a compensation in the immense increase which it has occasioned in both the
product and the profits of the sulphur mines. Flour of sulphur is applied to
the vine as a remedy against the disease, and the operation is repeated from
two to three or four—and sometimes even eight or ten—times in a season.
Hence there is a great demand for sulphur in all the vine-growing countries
of Europe, and
Waltershausen estimates the annual consumption of that mineral for this
single purpose at 850,000 centner, or more than forty thousand tons. The
price of sulphur has risen in about the same proportion as that of the wine.
—Waltershausen, Ueber den Sicilianischen Ackerbau, pp. 19, 20.]
All the operations of rural husbandry are destructive to spontaneous
vegetation by the voluntary substitution of domestic for wild plants, and, as
"has quintupled, and as the product of the vintage has not diminished in the
same proportion, the crisis has been, on the whole, rather advantageous than
detrimental to the country."—Economie rurale de la France, pp. 263, 264.
France produces a large surplus of wines for exportation, and the sales to
foreign consumers are the principal source of profit to French vinegrowers.
In Northern Italy, on the contrary, which exports little wine, there has been
no such increase in the price of wine as to compensate the great diminution
in the yield of the vines, and the loss of this harvest is severely felt. In
Sicily, however, which exports much wine, prices have risen as rapidly as in
France. Waltershausen informs us that in the years 1838-'42, the red wine of
Mount Etna sold at the rate of one kreuzer and a half, or one cent the bottle,
and sometimes even at but two thirds that price, but that at present it
commands five or six times as much.
The grape disease has operated severely on small cultivators whose
vineyards only furnished a supply for domestic use, but Sicily has received
a compensation in the immense increase which it has occasioned in both the
product and the profits of the sulphur mines. Flour of sulphur is applied to
the vine as a remedy against the disease, and the operation is repeated from
two to three or four—and sometimes even eight or ten—times in a season.
Hence there is a great demand for sulphur in all the vine-growing countries
of Europe, and
Waltershausen estimates the annual consumption of that mineral for this
single purpose at 850,000 centner, or more than forty thousand tons. The
price of sulphur has risen in about the same proportion as that of the wine.
—Waltershausen, Ueber den Sicilianischen Ackerbau, pp. 19, 20.]
All the operations of rural husbandry are destructive to spontaneous
vegetation by the voluntary substitution of domestic for wild plants, and, as
Page 126
we have seen, the armies of the colonist are attended by troops of irregular
and unrecognized camp-followers, which soon establish and propagate
themselves over the new conquests. These unbidden and hungry guests—
the gipsies of the vegetable world—often have great aptitude for
accommodation and acclimation, and sometimes even crowd out the native
growth to make room for themselves. The botanist Latham informs us that
indigenous flowering plants, once abundant on the North-Western prairies,
have been so nearly extirpated by the inroads of half-wild vegetables which
have come in the train of the Eastern immigrant, that there is reason to fear
that, in a few years, his herbarium will constitute the only evidence of their
former existence. [Footnote: Report of Commissioner of Agriculture of the
United States for 1870.]
There are plants—themselves perhaps sometimes stragglers from their
proper habitat—which are found only in small numbers and in few
localities. These are eagerly sought by the botanist, and some such species
are believed to be on the very verge of extinction, from the zeal of
collectors.
ANIMAL LIFE AS A GEOLOGICAL AND GEOGRAPHICAL
AGENCY.
The quantitative value of animated life, as a geological agency, seems to be
inversely as the volume of the individual organism; for nature supplies by
numbers what is wanting in the bulk of the animal out of whose remains or
structures she forms strata covering whole provinces, and builds up from
the depths of the sea large islands, if not continents. There are, it is true,
near the mouths of the great Siberian rivers which empty themselves into
the Polar Sea, drift islands composed, in an incredibly large proportion, of
the bones and tusks of elephants, mastodons, and other huge pachyderms,
and many extensive caves in various parts of the world are half filled with
and unrecognized camp-followers, which soon establish and propagate
themselves over the new conquests. These unbidden and hungry guests—
the gipsies of the vegetable world—often have great aptitude for
accommodation and acclimation, and sometimes even crowd out the native
growth to make room for themselves. The botanist Latham informs us that
indigenous flowering plants, once abundant on the North-Western prairies,
have been so nearly extirpated by the inroads of half-wild vegetables which
have come in the train of the Eastern immigrant, that there is reason to fear
that, in a few years, his herbarium will constitute the only evidence of their
former existence. [Footnote: Report of Commissioner of Agriculture of the
United States for 1870.]
There are plants—themselves perhaps sometimes stragglers from their
proper habitat—which are found only in small numbers and in few
localities. These are eagerly sought by the botanist, and some such species
are believed to be on the very verge of extinction, from the zeal of
collectors.
ANIMAL LIFE AS A GEOLOGICAL AND GEOGRAPHICAL
AGENCY.
The quantitative value of animated life, as a geological agency, seems to be
inversely as the volume of the individual organism; for nature supplies by
numbers what is wanting in the bulk of the animal out of whose remains or
structures she forms strata covering whole provinces, and builds up from
the depths of the sea large islands, if not continents. There are, it is true,
near the mouths of the great Siberian rivers which empty themselves into
the Polar Sea, drift islands composed, in an incredibly large proportion, of
the bones and tusks of elephants, mastodons, and other huge pachyderms,
and many extensive caves in various parts of the world are half filled with
Page 127
the skeletons of quadrupeds, sometimes lying loose in the earth, sometimes
cemented together into an osseous breccia by a calcareous deposit or other
binding material. These remains of large animals, though found in
comparatively late formations, generally belong to extinct species, and their
modern congeners or representatives do not exist in sufficient numbers to
be of sensible importance in geology or in geography by the mere mass of
their skeletons. [Footnote: Could the bones and other relics of the domestic
quadrupeds destroyed by disease or slaughtered for human use in civilized
countries be collected into large deposits, as obscure causes have gathered
together those of extinct animals, they would soon form aggregations which
might almost be called mountains. There were in the United States, in 1870,
as we shall see hereafter, nearly one hundred millions of horses, black
cattle, sheep, and swine. There are great numbers of all the same animals in
the British American Provinces and in Mexico, and there are large herds of
wild horses on the plains, and of tamed among the independent Indian tribes
of North America. It would perhaps not be extravagant to suppose that all
these cattle may amount to two thirds as many as those of the United States,
and thus we have in North America a total of 160,000,000 domestic
quadrupeds belonging to species introduced by European colonization,
besides dogs, cats, and other four-footed household pets and pests, also of
foreign origin.
If we allow half a solid foot to the skeleton and other slowly destructible
parts of each animal, the remains of these herds would form a cubical mass
measuring not much short of four hundred and fifty feet to the side, or a
pyramid equal in dimensions to that of Cheops, and as the average life of
these animals does not exceed six or seven years, the accumulations of their
bones, horns, hoofs, and other durable remains would amount to at least
fifteen times as great a volume in a single century. It is true that the actual
mass of solid matter, left by the decay of dead domestic quadrupeds and
permanently added to the crust of the earth, is not so great as this
cemented together into an osseous breccia by a calcareous deposit or other
binding material. These remains of large animals, though found in
comparatively late formations, generally belong to extinct species, and their
modern congeners or representatives do not exist in sufficient numbers to
be of sensible importance in geology or in geography by the mere mass of
their skeletons. [Footnote: Could the bones and other relics of the domestic
quadrupeds destroyed by disease or slaughtered for human use in civilized
countries be collected into large deposits, as obscure causes have gathered
together those of extinct animals, they would soon form aggregations which
might almost be called mountains. There were in the United States, in 1870,
as we shall see hereafter, nearly one hundred millions of horses, black
cattle, sheep, and swine. There are great numbers of all the same animals in
the British American Provinces and in Mexico, and there are large herds of
wild horses on the plains, and of tamed among the independent Indian tribes
of North America. It would perhaps not be extravagant to suppose that all
these cattle may amount to two thirds as many as those of the United States,
and thus we have in North America a total of 160,000,000 domestic
quadrupeds belonging to species introduced by European colonization,
besides dogs, cats, and other four-footed household pets and pests, also of
foreign origin.
If we allow half a solid foot to the skeleton and other slowly destructible
parts of each animal, the remains of these herds would form a cubical mass
measuring not much short of four hundred and fifty feet to the side, or a
pyramid equal in dimensions to that of Cheops, and as the average life of
these animals does not exceed six or seven years, the accumulations of their
bones, horns, hoofs, and other durable remains would amount to at least
fifteen times as great a volume in a single century. It is true that the actual
mass of solid matter, left by the decay of dead domestic quadrupeds and
permanently added to the crust of the earth, is not so great as this
Page 128
calculation makes it. The greatest proportion of the soft parts of domestic
animals, and even of the bones, is soon decomposed, through direct
consumption by man and other carnivora, industrial use, and employment
as manure, and enters into new combinations in which its animal origin is
scarcely traceable; there is, nevertheless, a large annual residuum, which,
like decayed vegetable matter, becomes a part of the superficial mould; and
in any event, brute life immensely changes the form and character of the
superficial strata, if it does not sensibly augment the quantity of the matter
composing them. The remains of man, too, add to the earthy coating that
covers the face of the globe. The human bodies deposited in the catacombs
during the long, long ages of Egyptian history, would perhaps build as large
a pile as one generation of the quadrupeds of the United States. In the
barbarous days of old Moslem warfare, the conquerors erected large
pyramids of human skulls. The soil of cemeteries in the great cities of
Europe has sometimes been raised several feet by the deposit of the dead
during a few generations. In the East, Turks and Christians alike bury
bodies but a cople of feet beneath the sculptures of the ignoble poor, and of
those whose monuments time or accident has removed, are opened again
and again to receive fresh occupants. Hence the ground in Oriental
cemeteries is pervaded with relics of humanity, of not wholly composed of
them; and an examination of the soil of the lower part of the Petit Champ
des Morts, at Pera, by the naked eye alone, shows the observer that it
consists almost exclusively of the comminuted bones of his fellow-man.]
But the vegetable products found with them, and, in rare cases, in the
stomachs of some of them, are those of yet extant plants; and besides this
evidence, the discovery of works of human art, deposited in juxtaposition
with fossil bones, and evidently at the same time and by the same agency
which buried these latter—not to speak of human bones found in the same
strata—proves that the animals whose former existence they testify were
contemporaneous with man, and possibly even extirpated by him.
animals, and even of the bones, is soon decomposed, through direct
consumption by man and other carnivora, industrial use, and employment
as manure, and enters into new combinations in which its animal origin is
scarcely traceable; there is, nevertheless, a large annual residuum, which,
like decayed vegetable matter, becomes a part of the superficial mould; and
in any event, brute life immensely changes the form and character of the
superficial strata, if it does not sensibly augment the quantity of the matter
composing them. The remains of man, too, add to the earthy coating that
covers the face of the globe. The human bodies deposited in the catacombs
during the long, long ages of Egyptian history, would perhaps build as large
a pile as one generation of the quadrupeds of the United States. In the
barbarous days of old Moslem warfare, the conquerors erected large
pyramids of human skulls. The soil of cemeteries in the great cities of
Europe has sometimes been raised several feet by the deposit of the dead
during a few generations. In the East, Turks and Christians alike bury
bodies but a cople of feet beneath the sculptures of the ignoble poor, and of
those whose monuments time or accident has removed, are opened again
and again to receive fresh occupants. Hence the ground in Oriental
cemeteries is pervaded with relics of humanity, of not wholly composed of
them; and an examination of the soil of the lower part of the Petit Champ
des Morts, at Pera, by the naked eye alone, shows the observer that it
consists almost exclusively of the comminuted bones of his fellow-man.]
But the vegetable products found with them, and, in rare cases, in the
stomachs of some of them, are those of yet extant plants; and besides this
evidence, the discovery of works of human art, deposited in juxtaposition
with fossil bones, and evidently at the same time and by the same agency
which buried these latter—not to speak of human bones found in the same
strata—proves that the animals whose former existence they testify were
contemporaneous with man, and possibly even extirpated by him.
Page 129
[Footnote: The bones of mammoths and mastodons, in many instances,
appear to have been grazed or cut by flint arrow-heads or other stone
weapons, and the bones of animals now extinct are often wrought into arms
and utensils, or split to extract the marrow. These accounts have often been
discredited, because it has been assumed that the extinction of these animals
was more ancient than the existence of man. Recent discoveries render it
certain that this conclusion has been too hastily adopted.
On page 143 of the Antiquity of Man, Lyell remarks that man "no doubt
played his part in hastening the era of the extincion" of the large
pachyderms and beasts of prey; but, as contemporaneous species of other
animals, which man cannot be supposed to have extirpated, have also
become extinct, he argues that the disappearance of the quadrupeds in
question cannot be ascribed to human action alone.
On this point it may be observed that, as we cannot know what precise
physical conditions were necessary to the existence of a given extinct
organism, we cannot say how far such conditions may have been modified
by the action of man, and he may therefore have influenced the life of such
organisms in ways, and to an extent, of which we can form no just idea.] I
do not propose to enter upon the thorny question, whether the existing races
of man are genealogically connected with these ancient types of humanity,
and I advert to these facts only for the sake of the suggestion, that man, in
his earliest known stages of existence, was probably a destructive power
upon the earth, though perhaps not so emphatically as his present
representatives. The larger wild animals are not now numerous enough in
any one region to form extensive deposits by their remains; but they have,
nevertheless, a certain geographical importance. If the myriads of large
browsing and grazing quadrupeds which wander over the plains of Southern
Africa—and the slaughter of which by thousands is the source of a
ferocious pleasure and a brutal triumph to professedly civilized hunters—if
appear to have been grazed or cut by flint arrow-heads or other stone
weapons, and the bones of animals now extinct are often wrought into arms
and utensils, or split to extract the marrow. These accounts have often been
discredited, because it has been assumed that the extinction of these animals
was more ancient than the existence of man. Recent discoveries render it
certain that this conclusion has been too hastily adopted.
On page 143 of the Antiquity of Man, Lyell remarks that man "no doubt
played his part in hastening the era of the extincion" of the large
pachyderms and beasts of prey; but, as contemporaneous species of other
animals, which man cannot be supposed to have extirpated, have also
become extinct, he argues that the disappearance of the quadrupeds in
question cannot be ascribed to human action alone.
On this point it may be observed that, as we cannot know what precise
physical conditions were necessary to the existence of a given extinct
organism, we cannot say how far such conditions may have been modified
by the action of man, and he may therefore have influenced the life of such
organisms in ways, and to an extent, of which we can form no just idea.] I
do not propose to enter upon the thorny question, whether the existing races
of man are genealogically connected with these ancient types of humanity,
and I advert to these facts only for the sake of the suggestion, that man, in
his earliest known stages of existence, was probably a destructive power
upon the earth, though perhaps not so emphatically as his present
representatives. The larger wild animals are not now numerous enough in
any one region to form extensive deposits by their remains; but they have,
nevertheless, a certain geographical importance. If the myriads of large
browsing and grazing quadrupeds which wander over the plains of Southern
Africa—and the slaughter of which by thousands is the source of a
ferocious pleasure and a brutal triumph to professedly civilized hunters—if
Page 130
the herds of the American bison, which are numbered by hundreds of
thousands, do not produce visible changes in the forms of terrestrial surface,
they have at least an immense influence on the growth and distribution of
vegetable life, and, of course, indirectly upon all the physical conditions of
soil and climate between which and vegetation a mutual interdependence
exists. In the preceding chapter I referred to the agency of the beaver in the
formation of bogs as producing sensible geographical effects.
I am disposed to think that more bogs in the Northern States owe their
origin to beavers than to accidental obstructions of rivulets by wind-fallen
or naturally decayed trees; for there are few swamps in those States, at the
outlets of which we may not, by careful search, find the remains of a beaver
dam. The beaver sometimes inhabits natural lakelets and even large rivers
like the Upper Mississippi, when the current is not too rapid, but he prefers
to owe his pond to his own ingenuity and toil. The reservoir once
constructed, its inhabitants rapidly multiply so long as the trees, and the
harvests of pond lilies and other aquatic plants on which this quadruped
feeds in winter, suffice for the supply of the growing population. But the
extension of the water causes the death of the neighboring trees, and the
annual growth of those which could be reached by canals and floated to the
pond soon becomes insufficient for the wants of the community, and the
beaver metropolis now sends out expeditions of discovery and colonization.
The pond gradually fills up, by the operation of the same causes as when it
owes its existence to an accidental obstruction, and when, at last, the
original settlement is converted into a bog by the usual processes of
vegetable life, the remaining inhabitants abandon it and build on some
virgin brooklet a new city of the waters. [Footnote: I find confirmation of
my own observations on this point (published in 1863) in the North-West
Passage by Land of Milton and Cheadle, London, 1865. These travellers
observed "a long chain of marshes formed by the damming up of a stream
which had now ceased to exist," Chap. X. In Chap. XII, they state that
thousands, do not produce visible changes in the forms of terrestrial surface,
they have at least an immense influence on the growth and distribution of
vegetable life, and, of course, indirectly upon all the physical conditions of
soil and climate between which and vegetation a mutual interdependence
exists. In the preceding chapter I referred to the agency of the beaver in the
formation of bogs as producing sensible geographical effects.
I am disposed to think that more bogs in the Northern States owe their
origin to beavers than to accidental obstructions of rivulets by wind-fallen
or naturally decayed trees; for there are few swamps in those States, at the
outlets of which we may not, by careful search, find the remains of a beaver
dam. The beaver sometimes inhabits natural lakelets and even large rivers
like the Upper Mississippi, when the current is not too rapid, but he prefers
to owe his pond to his own ingenuity and toil. The reservoir once
constructed, its inhabitants rapidly multiply so long as the trees, and the
harvests of pond lilies and other aquatic plants on which this quadruped
feeds in winter, suffice for the supply of the growing population. But the
extension of the water causes the death of the neighboring trees, and the
annual growth of those which could be reached by canals and floated to the
pond soon becomes insufficient for the wants of the community, and the
beaver metropolis now sends out expeditions of discovery and colonization.
The pond gradually fills up, by the operation of the same causes as when it
owes its existence to an accidental obstruction, and when, at last, the
original settlement is converted into a bog by the usual processes of
vegetable life, the remaining inhabitants abandon it and build on some
virgin brooklet a new city of the waters. [Footnote: I find confirmation of
my own observations on this point (published in 1863) in the North-West
Passage by Land of Milton and Cheadle, London, 1865. These travellers
observed "a long chain of marshes formed by the damming up of a stream
which had now ceased to exist," Chap. X. In Chap. XII, they state that
Page 131
"nearly every stream between the Pembina and the Athabasca—except the
large river McLeod—appeared to have been destroyed by the agency of the
beaver," and they question whether the vast extent of swampy ground in
that region "has not been brought to this condition by the work of beavers
who have thus destroyed, by their own labor, the streams necessary to their
own existence."
But even here nature provides a remedy, for when the process of
"consolidation" referred to in treating of bogs in the first chapter shall have
been completed, and the forest re-established upon the marshes, the water
now diffused through them will be collected in the lower or more yielding
portions, cut new channels for their flow, become running brooks, and thus
restore the ancient aspect of the surface.
The authors add the curious observation that the beavers of the present
day seem to be a degenerate race, as they neither fell huge trees not
construct great dams, while their progenitors cut down trees two feet in
diameter and dammed up rivers a hundred feet in width. The change in the
habits of the beaver is probably due to the diminution of their numbers
since the introduction of fire-arms, and to the tact that their hydraulic
operations are more frequently interrupted by the encroachments of man. In
the valley of the Yellowstone, which has but lately been much visited by the
white man, Hayden saw stumps of trees thirty inches in diameter which had
been cut down by beavers. —Geological Survey of Wyoming, p. 135.
The American beaver closely resembles his European congener, and I
believe most naturalists now regard them as identical. A difference of
speceies has been inferred from a difference in their modes of life, the
European animal being solitary and not a builder, the American gregarious
and constructive. But late careful researches in Germany have shown the
former existence of numerous beaver dams in that country, though the
large river McLeod—appeared to have been destroyed by the agency of the
beaver," and they question whether the vast extent of swampy ground in
that region "has not been brought to this condition by the work of beavers
who have thus destroyed, by their own labor, the streams necessary to their
own existence."
But even here nature provides a remedy, for when the process of
"consolidation" referred to in treating of bogs in the first chapter shall have
been completed, and the forest re-established upon the marshes, the water
now diffused through them will be collected in the lower or more yielding
portions, cut new channels for their flow, become running brooks, and thus
restore the ancient aspect of the surface.
The authors add the curious observation that the beavers of the present
day seem to be a degenerate race, as they neither fell huge trees not
construct great dams, while their progenitors cut down trees two feet in
diameter and dammed up rivers a hundred feet in width. The change in the
habits of the beaver is probably due to the diminution of their numbers
since the introduction of fire-arms, and to the tact that their hydraulic
operations are more frequently interrupted by the encroachments of man. In
the valley of the Yellowstone, which has but lately been much visited by the
white man, Hayden saw stumps of trees thirty inches in diameter which had
been cut down by beavers. —Geological Survey of Wyoming, p. 135.
The American beaver closely resembles his European congener, and I
believe most naturalists now regard them as identical. A difference of
speceies has been inferred from a difference in their modes of life, the
European animal being solitary and not a builder, the American gregarious
and constructive. But late careful researches in Germany have shown the
former existence of numerous beaver dams in that country, though the
Page 132
animal, having becaome rare to form colonies, has of course ceased to
attempt works which require the co-operation of numerous individuals.—
Schleiden, Fur Baum und Wald Leipzig, 1870, p. 68.
On the question of identity and on all others relating to this interesting
animal, see L.H. Morgan's important monograph, The American Beaver and
his Works, Philadelphia, 1868. Among the many new facts observed by this
investigator is the construction of canals by the beaver to float trunks and
branches of trees to his ponds. These canals are sometimes 600 to 700 feet
long, with a width of two or three feet and a depth of one to one and a half.]
INFLUENCE OF ANIMAL LIFE ON VEGETATION
The influence of wild quadrupeds upon vegetable life have been little
studied, and not many facts bearing upon it have been recorded, but, so far
as it is known, it appears to be conservative rather than pernicious. Few
wild animals depend for their subsistence on vegetable products obtainable
only by the destruction of the plant, and they seem to confine their
consumption almost exclusively to the annual harvest of leaf or twig, or at
least of parts of the vegetable easily reproduced. If there are exceptions to
this rule, they are in cases where the numbers of the animal are so
proportioned to the abundance of the vegetable that there is no danger of the
extermination of the plant from the voracity of the quadruped, or of the
extinction of the quadruped from the scarcity of the plant. [Footnote:
European foresters speak of the action of the squirrel as injurious to trees.
Doubtless this is sometimes true in the case of artificial forests, but in
woods of spontaneous growth, ordered and governed by nature, the squirrel
does not attack trees, or at least the injury he may do is too trifling to be
perceptible, but he is a formidable enemy to the plantation. "The squirrels
bite the cones of the pine and consume the seed which might serve to
attempt works which require the co-operation of numerous individuals.—
Schleiden, Fur Baum und Wald Leipzig, 1870, p. 68.
On the question of identity and on all others relating to this interesting
animal, see L.H. Morgan's important monograph, The American Beaver and
his Works, Philadelphia, 1868. Among the many new facts observed by this
investigator is the construction of canals by the beaver to float trunks and
branches of trees to his ponds. These canals are sometimes 600 to 700 feet
long, with a width of two or three feet and a depth of one to one and a half.]
INFLUENCE OF ANIMAL LIFE ON VEGETATION
The influence of wild quadrupeds upon vegetable life have been little
studied, and not many facts bearing upon it have been recorded, but, so far
as it is known, it appears to be conservative rather than pernicious. Few
wild animals depend for their subsistence on vegetable products obtainable
only by the destruction of the plant, and they seem to confine their
consumption almost exclusively to the annual harvest of leaf or twig, or at
least of parts of the vegetable easily reproduced. If there are exceptions to
this rule, they are in cases where the numbers of the animal are so
proportioned to the abundance of the vegetable that there is no danger of the
extermination of the plant from the voracity of the quadruped, or of the
extinction of the quadruped from the scarcity of the plant. [Footnote:
European foresters speak of the action of the squirrel as injurious to trees.
Doubtless this is sometimes true in the case of artificial forests, but in
woods of spontaneous growth, ordered and governed by nature, the squirrel
does not attack trees, or at least the injury he may do is too trifling to be
perceptible, but he is a formidable enemy to the plantation. "The squirrels
bite the cones of the pine and consume the seed which might serve to
Page 133
restock the wood; they do still more mischief by gnawing off, near the
leading shoot, a strip of bark, and thus often completely girdling the tree.
Trees so injured must be felled, as they would never acquire a vigorous
growth. The squirrel is especially destructive to the pine in Sologne, where
he gnaws the bark of trees twenty or twenty-five years old." But even here,
nature sometimes provides a compensation, by making the appetite of this
quadruped serve to prevent an excessive production of seed cones, which
tends to obstruct the due growth of the leading shoot. "In some of the
pineries of Brittany which produce cones so abundantly as to strangle the
development of the leading shoot of the maritime pine, it has been observed
that the pines are most vigorous where the squirrels are most numerous, a
result attributed to the repression of the cones by this rodent."—Boitel,
Mise en valeur des Terres pauvres, p. 50.
Very interesting observations, on the agency of the squirrel and other
small animals in planting and in destroying nuts and other seeds of trees,
may be found in a paper on the Succession of Forests in Thoreau's
Excursions, pp. 135 et seqq.
I once saw several quarts of beech-nuts taken from the winter quarters of
a family of flying squirrels in a hollow tree. The kernels were neatly
stripped of the shells and carefully stored in a dry cavity.] In diet and
natural wants the bison resembles the ox, the ibex and the chamois
assimilate themselves to the goat and the sheep; but while the wild animal
does not appear to be a destructive agency in the garden of nature, his
domestic congeners are eminently so. [Footnote: Evelyn thought the
depasturing of grass by cattle serviceable to its growth. "The biting of
cattle," he remarks, "gives a gentle loosening to the roots of the herbage,
and makes it to grow fine and sweet, and their very breath and treading as
well as soil, and the comfort of their warm bodies, is wholesome and
leading shoot, a strip of bark, and thus often completely girdling the tree.
Trees so injured must be felled, as they would never acquire a vigorous
growth. The squirrel is especially destructive to the pine in Sologne, where
he gnaws the bark of trees twenty or twenty-five years old." But even here,
nature sometimes provides a compensation, by making the appetite of this
quadruped serve to prevent an excessive production of seed cones, which
tends to obstruct the due growth of the leading shoot. "In some of the
pineries of Brittany which produce cones so abundantly as to strangle the
development of the leading shoot of the maritime pine, it has been observed
that the pines are most vigorous where the squirrels are most numerous, a
result attributed to the repression of the cones by this rodent."—Boitel,
Mise en valeur des Terres pauvres, p. 50.
Very interesting observations, on the agency of the squirrel and other
small animals in planting and in destroying nuts and other seeds of trees,
may be found in a paper on the Succession of Forests in Thoreau's
Excursions, pp. 135 et seqq.
I once saw several quarts of beech-nuts taken from the winter quarters of
a family of flying squirrels in a hollow tree. The kernels were neatly
stripped of the shells and carefully stored in a dry cavity.] In diet and
natural wants the bison resembles the ox, the ibex and the chamois
assimilate themselves to the goat and the sheep; but while the wild animal
does not appear to be a destructive agency in the garden of nature, his
domestic congeners are eminently so. [Footnote: Evelyn thought the
depasturing of grass by cattle serviceable to its growth. "The biting of
cattle," he remarks, "gives a gentle loosening to the roots of the herbage,
and makes it to grow fine and sweet, and their very breath and treading as
well as soil, and the comfort of their warm bodies, is wholesome and
Page 134
marvellously cherishing."—Terra, or Philosophical Discourses of Earth, p.
86.
In a note upon this passage, Hunter observes: "Nice farmers consider the
lying of a beast upon the ground, for one night only, as a sufficient tilth for
the year. The breath of graminivorous quadrupeds does certainly enrich the
roots of grass; a circumstance worthy of the attention of the philosophical
farmer."—Terra, same page.
The "philosophical farmer" of the present day will not adopt these
opinions without some qualification, and they certainly are not sustained by
American observation.
The Report of the Department of Agriculture for March and April, 1872,
states that the native grasses are disappearing from the prairies of Texas,
especially on the bottom-lands, depasturing of cattle being destructive to
them.] This is partly from the change of habits resulting from domestication
and association with man, partly from the fact that the number of reclaimed
animals is not determined by the natural relation of demand and
spontaneous supply which regulates the multiplication of wild creatures, but
by the convenience of man, who is, in comparatively few things, amenable
to the control of the merely physical arrangements of nature. When the
domesticated animal escapes from human jurisdiction, as in the case of the
ox, the horse, the goat, and perhaps the ass—which, so far as I know, are
the only well-authenticated instances of the complete emancipation of
household quadrupeds—he becomes again an unresisting subject of nature,
and all his economy is governed by the same laws as that of his fellows
which have never been enslaved by man; but, so long as he obeys a human
lord, he is an auxiliary in the warfare his master is ever waging against all
existences except those which he can tame to a willing servitude.
86.
In a note upon this passage, Hunter observes: "Nice farmers consider the
lying of a beast upon the ground, for one night only, as a sufficient tilth for
the year. The breath of graminivorous quadrupeds does certainly enrich the
roots of grass; a circumstance worthy of the attention of the philosophical
farmer."—Terra, same page.
The "philosophical farmer" of the present day will not adopt these
opinions without some qualification, and they certainly are not sustained by
American observation.
The Report of the Department of Agriculture for March and April, 1872,
states that the native grasses are disappearing from the prairies of Texas,
especially on the bottom-lands, depasturing of cattle being destructive to
them.] This is partly from the change of habits resulting from domestication
and association with man, partly from the fact that the number of reclaimed
animals is not determined by the natural relation of demand and
spontaneous supply which regulates the multiplication of wild creatures, but
by the convenience of man, who is, in comparatively few things, amenable
to the control of the merely physical arrangements of nature. When the
domesticated animal escapes from human jurisdiction, as in the case of the
ox, the horse, the goat, and perhaps the ass—which, so far as I know, are
the only well-authenticated instances of the complete emancipation of
household quadrupeds—he becomes again an unresisting subject of nature,
and all his economy is governed by the same laws as that of his fellows
which have never been enslaved by man; but, so long as he obeys a human
lord, he is an auxiliary in the warfare his master is ever waging against all
existences except those which he can tame to a willing servitude.
Page 135
ORIGIN AND TRANSFER OF DOMESTIC QUADRUPEDS.
Civilization is so intimately associated with certain inferior forms of animal
life, if not dependent on them, that cultivated man has never failed to
accompany himself, in all his migrations, with some of these humble
attendants. The ox, the horse, the sheep, and even the comparatively useless
dog and cat, as well as several species of poultry, are voluntarily transferred
by every emigrant colony, and they soon multiply to numbers far exceeding
those of the wild genera most nearly corresponding to them. [Footnote: The
rat and the mouse, though not voluntarily transported, are passengers by
every ship that sails for a foreign port, and several species of these
quadrupeds have, consequently, much extended their range and increased
their numbers in modern times. From a story of Heliogabalus related by
Lampridius, Hist. Aug. Scriptores, ed. Casaubon, 1690, p. 110, it would
seem that mice at least were not very common in ancient Rome. Among the
capricious freaks of that emperor, it is said that he undertook to investigate
the statistics of the arachnoid population of the capital, and that 10,000
pounds of spiders (or spiders' webs—for aranea is equivocal) were readily
collected; but when he got up a mouse-show, he thought ten thousand mice
a very fair number. Rats are not less numerous in all great cities; and in
Paris, where their skins are used for gloves, and their flesh, it is whispered,
in some very complex and equivocal dishes, they are caught by legions. I
have read of a manufacturer who contracted to buy of the rat-catchers, at a
high price, all the rat-skins they could furnish before a certain date, and
failed, within a week, for want of capital, when the stock of peltry had run
up to 600,000.
Civilization has not contented itself with the introduction of domestic
animals alone. The English sportsman imports foxes from the continent, and
Grimalkin-like turns them loose in order that he may have the pleasure of
chasing them afterwards.]
Civilization is so intimately associated with certain inferior forms of animal
life, if not dependent on them, that cultivated man has never failed to
accompany himself, in all his migrations, with some of these humble
attendants. The ox, the horse, the sheep, and even the comparatively useless
dog and cat, as well as several species of poultry, are voluntarily transferred
by every emigrant colony, and they soon multiply to numbers far exceeding
those of the wild genera most nearly corresponding to them. [Footnote: The
rat and the mouse, though not voluntarily transported, are passengers by
every ship that sails for a foreign port, and several species of these
quadrupeds have, consequently, much extended their range and increased
their numbers in modern times. From a story of Heliogabalus related by
Lampridius, Hist. Aug. Scriptores, ed. Casaubon, 1690, p. 110, it would
seem that mice at least were not very common in ancient Rome. Among the
capricious freaks of that emperor, it is said that he undertook to investigate
the statistics of the arachnoid population of the capital, and that 10,000
pounds of spiders (or spiders' webs—for aranea is equivocal) were readily
collected; but when he got up a mouse-show, he thought ten thousand mice
a very fair number. Rats are not less numerous in all great cities; and in
Paris, where their skins are used for gloves, and their flesh, it is whispered,
in some very complex and equivocal dishes, they are caught by legions. I
have read of a manufacturer who contracted to buy of the rat-catchers, at a
high price, all the rat-skins they could furnish before a certain date, and
failed, within a week, for want of capital, when the stock of peltry had run
up to 600,000.
Civilization has not contented itself with the introduction of domestic
animals alone. The English sportsman imports foxes from the continent, and
Grimalkin-like turns them loose in order that he may have the pleasure of
chasing them afterwards.]
Page 136
Of the origin of our domestic animals, we know historically nothing,
because their domestication belongs to the ages which preceded written
annals; but though they cannot all be specifically identified with now extant
wild animals, it is presumable that they have been reclaimed from an
originally wild state. Ancient writers have preserved to us fewer data
respecting the introduction of domestic animals into new countries than
respecting the transplantation of domestic vegetables. Ritter, in his learned
essay on the camel, has shown that this animal was not employed by the
Egyptians until a comparatively late period in their history; [Footnote: The
horse and the ass were equally unknown to ancient Egypt, and do not
appear in the sculptures before the XV. and XVI. dynasties. But even then,
the horse was only known as a draught animal, and the only representation
of a horseman yet found in the Egyptian tombs is on the blade of a battle
axe of uncertain origin and period.] that he was unknown to the
Carthaginians until after the downfall of their commonwealth; and that his
first appearance in Western Africa is more recent still. The Bactrian camel
was certainly brought from Asia Minor to the Northern shores of the Black
Sea, by the Goths, in the third or fourth century, and the buffalo first
appeared in Italy about A.D. 600, though it is unknown whence or by whom
he was introduced. [Footnote: Erdkunde, viii., Asien, 1ste Abtheuung, pp.
660,758. Hehn, Kuttonpflanzen, p. 845.] The Arabian single-humped camel,
or dromedary, has been carried to the Canary Islands, partially introduced
into Australia, Greece, Spain, and even Tuscany, experimented upon to little
purpose in Venezuela, and finally imported by the American Government
into Texas and New Mexico, where it finds the climate and the vegetable
products best suited to its wants, and promises to become a very useful
agent in the promotion of the special civilization for which those regions
are adapted.
Quadrupeds, both domestic and wild, bear the privations and discomforts
of long voyages better than would be supposed. The elephant, the giraffe,
because their domestication belongs to the ages which preceded written
annals; but though they cannot all be specifically identified with now extant
wild animals, it is presumable that they have been reclaimed from an
originally wild state. Ancient writers have preserved to us fewer data
respecting the introduction of domestic animals into new countries than
respecting the transplantation of domestic vegetables. Ritter, in his learned
essay on the camel, has shown that this animal was not employed by the
Egyptians until a comparatively late period in their history; [Footnote: The
horse and the ass were equally unknown to ancient Egypt, and do not
appear in the sculptures before the XV. and XVI. dynasties. But even then,
the horse was only known as a draught animal, and the only representation
of a horseman yet found in the Egyptian tombs is on the blade of a battle
axe of uncertain origin and period.] that he was unknown to the
Carthaginians until after the downfall of their commonwealth; and that his
first appearance in Western Africa is more recent still. The Bactrian camel
was certainly brought from Asia Minor to the Northern shores of the Black
Sea, by the Goths, in the third or fourth century, and the buffalo first
appeared in Italy about A.D. 600, though it is unknown whence or by whom
he was introduced. [Footnote: Erdkunde, viii., Asien, 1ste Abtheuung, pp.
660,758. Hehn, Kuttonpflanzen, p. 845.] The Arabian single-humped camel,
or dromedary, has been carried to the Canary Islands, partially introduced
into Australia, Greece, Spain, and even Tuscany, experimented upon to little
purpose in Venezuela, and finally imported by the American Government
into Texas and New Mexico, where it finds the climate and the vegetable
products best suited to its wants, and promises to become a very useful
agent in the promotion of the special civilization for which those regions
are adapted.
Quadrupeds, both domestic and wild, bear the privations and discomforts
of long voyages better than would be supposed. The elephant, the giraffe,
Page 137
the rhinoceros, and even the hippopotamus, do not seem to suffer much at
sea. Some of the camels imported by the U.S. government into Texas from
the Crimea and Northern Africa were a whole year on shipboard. On the
other hand, George Sand, in Un Hiver au Midi, gives an amusing
description of the sea-sickness of swine in the short passage from the
Baleares to Barcelona. America had no domestic quadruped but a species of
dog, the lama tribe, and, to a certain extent, the bison or buffalo. [Footnote:
See Chapter III., post; also Humboldt, Ansichten der Natur, i., p. 71. From
the anatomical character of the bones of the urus, or auerochs, found among
the relics of the lacustrine population of ancient Switzerland, and from
other circumstances, it is inferred that this animal had been domesticated by
that people; and it is stated, I know not upon what authority, in Le Alpi che
cingono l'Italia, that it had been tamed by the Veneti also. See Lyell,
Antiquity of Man, pp. 24, 25, and the last-named work, p. 480. This is a fact
of much interest, because it is one of the very few HISTORICALLY known
instances of the extinction of a domestic quadruped, and the extreme
improbability of such an event gives some countenance to the theory of the
identity of the domestic ox with, and its descent from, the urus.]Of course,
it owes the horse, the ass, the ox, the sheep, the goat, and the swine, as does
also Australia, to European colonization. Modern Europe has, thus far, not
accomplished much in the way of importation of new animals, though some
interesting essays have been made. The reindeer was successfully
introduced into Iceland about a century ago, while similar attempts failed,
about the same time, in Scotland. The Cashmere or Thibet goat was brought
to France a generation since, and succeeds well. The same or an allied
species and the Asiatic buffalo were carried to South Carolina about the
year 1850, and the former, at least, is thought likely to prove of permanent
value in the United States. [Footnote: The goat introduced into South
Carolina was brought from the district of Angora, in Asia Minor, which has
long been celebrated for flocks of this valuable animal. It is calculated that
sea. Some of the camels imported by the U.S. government into Texas from
the Crimea and Northern Africa were a whole year on shipboard. On the
other hand, George Sand, in Un Hiver au Midi, gives an amusing
description of the sea-sickness of swine in the short passage from the
Baleares to Barcelona. America had no domestic quadruped but a species of
dog, the lama tribe, and, to a certain extent, the bison or buffalo. [Footnote:
See Chapter III., post; also Humboldt, Ansichten der Natur, i., p. 71. From
the anatomical character of the bones of the urus, or auerochs, found among
the relics of the lacustrine population of ancient Switzerland, and from
other circumstances, it is inferred that this animal had been domesticated by
that people; and it is stated, I know not upon what authority, in Le Alpi che
cingono l'Italia, that it had been tamed by the Veneti also. See Lyell,
Antiquity of Man, pp. 24, 25, and the last-named work, p. 480. This is a fact
of much interest, because it is one of the very few HISTORICALLY known
instances of the extinction of a domestic quadruped, and the extreme
improbability of such an event gives some countenance to the theory of the
identity of the domestic ox with, and its descent from, the urus.]Of course,
it owes the horse, the ass, the ox, the sheep, the goat, and the swine, as does
also Australia, to European colonization. Modern Europe has, thus far, not
accomplished much in the way of importation of new animals, though some
interesting essays have been made. The reindeer was successfully
introduced into Iceland about a century ago, while similar attempts failed,
about the same time, in Scotland. The Cashmere or Thibet goat was brought
to France a generation since, and succeeds well. The same or an allied
species and the Asiatic buffalo were carried to South Carolina about the
year 1850, and the former, at least, is thought likely to prove of permanent
value in the United States. [Footnote: The goat introduced into South
Carolina was brought from the district of Angora, in Asia Minor, which has
long been celebrated for flocks of this valuable animal. It is calculated that
Page 138
more than a million of these goats are raised in that district, and it is
commonly believed that the Angora goat and its wool degenerate when
transported. Probably this is only an invention of the shepherds to prevent
rivals from attempting to interfere with so profitable a monopoly. But if the
popular prejudice has any foundation, the degeneracy is doubtless to be
attributed to ignorance of the special treatment which long experience has
taught the Angora shepherds, and the consequent neglect of such
precautions as are necessary to the proper care of the animal. Throughout
nearly the whole territory of the United States the success of the Angora
goat is perfect, and it would undoubtedly thrive equally well in Italy, though
it is very doubtful whether in either country the value of its fleece would
compensate the damage it would do to the woods.] The yak, or Tartary ox,
seems to thrive in France, and it is hoped that success will attend the present
efforts to introduce the South American alpaca into Europe. [Footnote: The
reproductive powers of animals, as well as of plants, seem to be sometimes
stimulated in an extraordinary way by transfer to a foreign clime. The
common warren rabbit introduced by the early colonists into the island of
Madeira multiplied to such a degree as to threaten the extirpation of
vegetation, and in Australia the same quadruped has become so numerous
as to be a very serious evil. The colonists are obliged to employ
professional rabbit-hunters, and one planter has enclosed his grounds by
four miles of solid wall, at an expense of $6,000, to protect his crops against
those ravagers.—Revue des Eaux et Forets, 1870, p. 38.]
According to the census of the United States for 1870, [Footnote: In the
enumeration of farm stock, "sucking pigs, spring lambs, and calves," are
omitted. I believe they are included in the numbers reported by the census
of 1860. Horses and horned cattle in towns and cities were excluded from
both enumerations, the law providing for returns on these points from rural
districts only. On the whole, there is a diminution in the number of all farm
stock, except sheep, since 1860. This is ascribed by the Report to the
commonly believed that the Angora goat and its wool degenerate when
transported. Probably this is only an invention of the shepherds to prevent
rivals from attempting to interfere with so profitable a monopoly. But if the
popular prejudice has any foundation, the degeneracy is doubtless to be
attributed to ignorance of the special treatment which long experience has
taught the Angora shepherds, and the consequent neglect of such
precautions as are necessary to the proper care of the animal. Throughout
nearly the whole territory of the United States the success of the Angora
goat is perfect, and it would undoubtedly thrive equally well in Italy, though
it is very doubtful whether in either country the value of its fleece would
compensate the damage it would do to the woods.] The yak, or Tartary ox,
seems to thrive in France, and it is hoped that success will attend the present
efforts to introduce the South American alpaca into Europe. [Footnote: The
reproductive powers of animals, as well as of plants, seem to be sometimes
stimulated in an extraordinary way by transfer to a foreign clime. The
common warren rabbit introduced by the early colonists into the island of
Madeira multiplied to such a degree as to threaten the extirpation of
vegetation, and in Australia the same quadruped has become so numerous
as to be a very serious evil. The colonists are obliged to employ
professional rabbit-hunters, and one planter has enclosed his grounds by
four miles of solid wall, at an expense of $6,000, to protect his crops against
those ravagers.—Revue des Eaux et Forets, 1870, p. 38.]
According to the census of the United States for 1870, [Footnote: In the
enumeration of farm stock, "sucking pigs, spring lambs, and calves," are
omitted. I believe they are included in the numbers reported by the census
of 1860. Horses and horned cattle in towns and cities were excluded from
both enumerations, the law providing for returns on these points from rural
districts only. On the whole, there is a diminution in the number of all farm
stock, except sheep, since 1860. This is ascribed by the Report to the
Page 139
destruction of domestic quadrupeds during the civil war, but this hardly
explains the reduction in the number of swine from 39,000,000 in 1800 to
25,000,000 in 1870.] the total number of horses in all the States of the
American Union, was, in round numbers, 7,100,000; of asses and mules,
1,100,000; of the ox tribe, 25,000,000; of sheep, 28,000,000; and of swine,
25,000,000. The only indigenous North American quadruped sufficiently
gregarious in habits, and sufficiently multiplied in numbers, to form really
large herds, is the bison, or, as he is commonly called in America, the
buffalo; and this animal is confined to the prairie region of the Mississippi
basin, a small part of British America, and Northern Mexico. The engineers
sent out to survey railroad routes to the Pacific estimated the number of a
single herd of bisons seen within the last fifteen years on the great plains
near the Upper Missouri, at not less than 200,000, and yet the range
occupied by this animal is now very much smaller in area than it was when
the whites first established themselves on the prairies. [Footnote: "About
five miles from camp we ascended to the top of a high hill, and for a great
distance ahead every square mile seemed to have a herd of buffalo upon it.
Their number was variously estimated by the members of the party; by
some as high as half a million. I do not think it any exaggeration to set it
down at 200,000." Steven's Narrative and Final Report. Reports of
Explorations and Surveys for Railroad to Pacific, vol xii, book i., 1860.
The next day the party fell in with a "buffalo trail," where at least
100,000 were thought to have crossed a slough.
As late as 1868, Sheridan's party estimated the number of bisons seen by
them in a single day at 200,000.—Sheridan's Troopers on the Border, 1868,
p. 41.] But it must be remarked that the American buffalo is a migratory
animal, and that, at the season of his annual journeys, the whole stock of a
vast extent of pasture-ground is collected into a single army, which is seen
at or very near any one point only for a few days during the entire season.
explains the reduction in the number of swine from 39,000,000 in 1800 to
25,000,000 in 1870.] the total number of horses in all the States of the
American Union, was, in round numbers, 7,100,000; of asses and mules,
1,100,000; of the ox tribe, 25,000,000; of sheep, 28,000,000; and of swine,
25,000,000. The only indigenous North American quadruped sufficiently
gregarious in habits, and sufficiently multiplied in numbers, to form really
large herds, is the bison, or, as he is commonly called in America, the
buffalo; and this animal is confined to the prairie region of the Mississippi
basin, a small part of British America, and Northern Mexico. The engineers
sent out to survey railroad routes to the Pacific estimated the number of a
single herd of bisons seen within the last fifteen years on the great plains
near the Upper Missouri, at not less than 200,000, and yet the range
occupied by this animal is now very much smaller in area than it was when
the whites first established themselves on the prairies. [Footnote: "About
five miles from camp we ascended to the top of a high hill, and for a great
distance ahead every square mile seemed to have a herd of buffalo upon it.
Their number was variously estimated by the members of the party; by
some as high as half a million. I do not think it any exaggeration to set it
down at 200,000." Steven's Narrative and Final Report. Reports of
Explorations and Surveys for Railroad to Pacific, vol xii, book i., 1860.
The next day the party fell in with a "buffalo trail," where at least
100,000 were thought to have crossed a slough.
As late as 1868, Sheridan's party estimated the number of bisons seen by
them in a single day at 200,000.—Sheridan's Troopers on the Border, 1868,
p. 41.] But it must be remarked that the American buffalo is a migratory
animal, and that, at the season of his annual journeys, the whole stock of a
vast extent of pasture-ground is collected into a single army, which is seen
at or very near any one point only for a few days during the entire season.
Page 140
Hence there is risk of great error in estimating the numbers of the bison in a
given district from the magnitude of the herds seen at or about the same
time at a single place of observation; and, upon the whole, it is neither
proved nor probable that the bison was ever, at any one time, as numerous
in North America as the domestic bovine species is at present. The elk, the
moose, the musk ox, the caribou, and the smaller quadrupeds popularly
embraced under the general name of deer, though sufficient for the wants of
a sparse savage population, were never numerically very abundant, and the
carnivora which fed upon them were still less so. It is almost needless to
add that the Rocky Mountain sheep and goat must always have been very
rare.
Summing up the whole, then, it is evident that the wild quadrupeds of
North America, even when most numerous, were few compared with their
domestic successors, that they required a much less supply of vegetable
food, and consequently were far less important as geographical elements
than the many millions of hoofed and horned cattle now fed by civilized
man on the same continent.
EXTIRPATION OF WILD QUADRUPEDS.
Although man never fails greatly to diminish, and is perhaps destined
ultimately to exterminate, such of the larger wild quadrupeds as he cannot
profitably domesticate, yet their numbers often fluctuate, and oven after
they seem almost extinct, they sometimes suddenly increase, without any
intentional steps to promote such a result on his part. During the wars which
followed the French Revolution, the wolf multiplied in many parts of
Europe, partly because the hunters were withdrawn from the woods to
chase a nobler game, and partly because the bodies of slain men and horses
supplied this voracious quadraped with more abundant food. [Footnote:
given district from the magnitude of the herds seen at or about the same
time at a single place of observation; and, upon the whole, it is neither
proved nor probable that the bison was ever, at any one time, as numerous
in North America as the domestic bovine species is at present. The elk, the
moose, the musk ox, the caribou, and the smaller quadrupeds popularly
embraced under the general name of deer, though sufficient for the wants of
a sparse savage population, were never numerically very abundant, and the
carnivora which fed upon them were still less so. It is almost needless to
add that the Rocky Mountain sheep and goat must always have been very
rare.
Summing up the whole, then, it is evident that the wild quadrupeds of
North America, even when most numerous, were few compared with their
domestic successors, that they required a much less supply of vegetable
food, and consequently were far less important as geographical elements
than the many millions of hoofed and horned cattle now fed by civilized
man on the same continent.
EXTIRPATION OF WILD QUADRUPEDS.
Although man never fails greatly to diminish, and is perhaps destined
ultimately to exterminate, such of the larger wild quadrupeds as he cannot
profitably domesticate, yet their numbers often fluctuate, and oven after
they seem almost extinct, they sometimes suddenly increase, without any
intentional steps to promote such a result on his part. During the wars which
followed the French Revolution, the wolf multiplied in many parts of
Europe, partly because the hunters were withdrawn from the woods to
chase a nobler game, and partly because the bodies of slain men and horses
supplied this voracious quadraped with more abundant food. [Footnote:
Page 141
During the late civil war in America, deer and other animals of the chase
multiplied rapidly in the regions of the Southern States which were partly
depopulated and deprived of their sportsmen by the military operations of
the contest, and the bear is said to have reappeared in districts where he had
not been seen in the memory of living man.] The same animal became again
more numerous in Poland after the general disarming of the rural population
by the Russian Government. On the other hand, when the hunters pursue
the wolf, the graminivorous wild quadrupeds increase, and thus in turn
promote the multiplication of their great four-footed destroyer by
augmenting the supply of his nourishment. So long as the fur of the beaver
was extensively employed as a material for hats, it bore a very high price,
and the chase of this quadruped was so keen that naturalists feared its
speedy extinction. When a Parisian manufacturer invented the silk hat,
which soon came into almost universal use, the demand for beavers' fur fell
off, and the animal—whose habits are an important agency in the formation
of bogs and other modifications of forest nature—immediately began to
increase, reappeared in haunts which he had long abandoned, and can no
longer be regarded as rare enough to be in immediate danger of extirpation.
Thus the convenience or the caprice of Parisian fashion has unconsciously
exercised an influence which may sensibly affect the physical geography of
a distant continent.
Since the invention of gunpowder, gome quadrupeds have completely
disappeared from many European and Asiatic countries where they were
formerly numerous. The last wolf was killed in Great Britain two hundred
years ago, and the bear was extirpated from that island still earlier. The lion
is believed to have inhabited Asia Minor and Syria, and probably Greece
and Sicily also, long after the commencement of the historical period, and
he is even said to have been not yet extinct in the first-named two of these
countries at the time of the first Crusade. [Footnote: In maintaining the
recent existence of the lion in the countries named in the text, naturalists
multiplied rapidly in the regions of the Southern States which were partly
depopulated and deprived of their sportsmen by the military operations of
the contest, and the bear is said to have reappeared in districts where he had
not been seen in the memory of living man.] The same animal became again
more numerous in Poland after the general disarming of the rural population
by the Russian Government. On the other hand, when the hunters pursue
the wolf, the graminivorous wild quadrupeds increase, and thus in turn
promote the multiplication of their great four-footed destroyer by
augmenting the supply of his nourishment. So long as the fur of the beaver
was extensively employed as a material for hats, it bore a very high price,
and the chase of this quadruped was so keen that naturalists feared its
speedy extinction. When a Parisian manufacturer invented the silk hat,
which soon came into almost universal use, the demand for beavers' fur fell
off, and the animal—whose habits are an important agency in the formation
of bogs and other modifications of forest nature—immediately began to
increase, reappeared in haunts which he had long abandoned, and can no
longer be regarded as rare enough to be in immediate danger of extirpation.
Thus the convenience or the caprice of Parisian fashion has unconsciously
exercised an influence which may sensibly affect the physical geography of
a distant continent.
Since the invention of gunpowder, gome quadrupeds have completely
disappeared from many European and Asiatic countries where they were
formerly numerous. The last wolf was killed in Great Britain two hundred
years ago, and the bear was extirpated from that island still earlier. The lion
is believed to have inhabited Asia Minor and Syria, and probably Greece
and Sicily also, long after the commencement of the historical period, and
he is even said to have been not yet extinct in the first-named two of these
countries at the time of the first Crusade. [Footnote: In maintaining the
recent existence of the lion in the countries named in the text, naturalists
Page 142
have, perhaps, laid. too much weight on the frequent occurrence of
representations of this animal in sculptures apparently of a historical
character. It will not do to argue, twenty centuries hence, that the lion and
the unicorn were common in Great Britain in Queen Victoria's time because
they are often seen "fighting for the crown" in the carvings and paintings of
that period. Many paleontolgists, however, identify the great cat-like
animal, whose skeletons are frequently found in British bone-caves, with
the lion of our times.
The leopard (panthera), though already growing scarce, was found in
Cilicia in Cicero's time. See his letter to Coelius, Epist. ad Diversos,
Lib. II., Ep. 11.
The British wild ox is extinct except in a few English and Scottish parks,
while in Irish bogs of no great apparent antiquity are found antlers which
testify to the former existence of a stag much larger than any extant
European species. Two large graminivorous or browsing quadrupeds, the ur
and the schelk, once common in Germany, have been utterly extirpated, the
eland and the auerochs nearly so. The Nibelungen-Lied, which, in the oldest
form preserved to us, dates from about the year 1200, though its original
composition no doubt belongs to an earlier period, thus sings:
Then slowe the dowghtie Sigfrid a wisent and an elk, he smote four
stoute uroxen and a grim and sturdie schelk. [Footnote: Dar nach sluoger
schiere, einen wisent unde elch. Starker ure viere, unt einen grimmen
schelch. XVI. Aventiure.
The testimony of the Nibelungen-Lied is not conclusive evidence that
these quadrupeds existed in Germany at the time of the composition of that
poem. It proves too much; for, a few lines above those just quoted, Sigfrid
is said to have killed a lion, an animal which the most patriotic Teuton will
hardly claim as a denizen of mediaeval Germany.]
representations of this animal in sculptures apparently of a historical
character. It will not do to argue, twenty centuries hence, that the lion and
the unicorn were common in Great Britain in Queen Victoria's time because
they are often seen "fighting for the crown" in the carvings and paintings of
that period. Many paleontolgists, however, identify the great cat-like
animal, whose skeletons are frequently found in British bone-caves, with
the lion of our times.
The leopard (panthera), though already growing scarce, was found in
Cilicia in Cicero's time. See his letter to Coelius, Epist. ad Diversos,
Lib. II., Ep. 11.
The British wild ox is extinct except in a few English and Scottish parks,
while in Irish bogs of no great apparent antiquity are found antlers which
testify to the former existence of a stag much larger than any extant
European species. Two large graminivorous or browsing quadrupeds, the ur
and the schelk, once common in Germany, have been utterly extirpated, the
eland and the auerochs nearly so. The Nibelungen-Lied, which, in the oldest
form preserved to us, dates from about the year 1200, though its original
composition no doubt belongs to an earlier period, thus sings:
Then slowe the dowghtie Sigfrid a wisent and an elk, he smote four
stoute uroxen and a grim and sturdie schelk. [Footnote: Dar nach sluoger
schiere, einen wisent unde elch. Starker ure viere, unt einen grimmen
schelch. XVI. Aventiure.
The testimony of the Nibelungen-Lied is not conclusive evidence that
these quadrupeds existed in Germany at the time of the composition of that
poem. It proves too much; for, a few lines above those just quoted, Sigfrid
is said to have killed a lion, an animal which the most patriotic Teuton will
hardly claim as a denizen of mediaeval Germany.]
Page 143
Modern naturalists identify the elk with the eland, the wisent with the
auerochs. The period when the ur and the schelk became extinct is not
known. The auerochs survived in Prussia until the middle of the last
century, but unless it is identical with a similar quadruped said to be found
on the Caucasus, it now exists only in the Russian imperial forest of
Bialowitz where about a thousand are still preserved, and in some great
menageries, as for example that at Schonbrunn, near Vienna, which, in
1852, had four specimens. The eland, which is closely allied to the
American wapiti if not specifically the same animal, is still kept in the royal
preserves of Prussia, to the number of four or five hundred individuals. The
chamois is becoming rare, and the ibex or steinbock, once common in all
the high Alps, is now believed to be confined to the Cogne mountains in
Piedmont, between the valleys of the Dora Baltea and the Orco, though it is
said that a few still linger about the Grandes Jorasses near Cormayeur.
The chase, which in early stages of human life was a necessity, has
become with advancing civilization not merely a passion but a
dilettanteism, and the cruel records of this pastime are among the most
discreditable pages in modern literature. It is true that in India and other
tropical countries, the number and ferocity of the wild beasts not only
justify but command a war of extermination against them, but the
indiscriminate slaughter of many quadrupeds which are favorite objects of
the chase can urge no such apology. Late official reports from India state
the number of human victims of the tiger, the leopard, the wolf and other
beasts of prey, in ten "districts," at more then twelve thousand within three
years, and we are informed on like authority that within the last six years
more than ten thousand men, women, and children have perished in the
same way in the Presidency of Bengal alone. One tiger, we are told, had
killed more than a hundred people, and finally stopped the travel on an
important road, and another had caused the desertion of thirteen villages
and thrown 250 square miles out of cultivation. In such facts we find
auerochs. The period when the ur and the schelk became extinct is not
known. The auerochs survived in Prussia until the middle of the last
century, but unless it is identical with a similar quadruped said to be found
on the Caucasus, it now exists only in the Russian imperial forest of
Bialowitz where about a thousand are still preserved, and in some great
menageries, as for example that at Schonbrunn, near Vienna, which, in
1852, had four specimens. The eland, which is closely allied to the
American wapiti if not specifically the same animal, is still kept in the royal
preserves of Prussia, to the number of four or five hundred individuals. The
chamois is becoming rare, and the ibex or steinbock, once common in all
the high Alps, is now believed to be confined to the Cogne mountains in
Piedmont, between the valleys of the Dora Baltea and the Orco, though it is
said that a few still linger about the Grandes Jorasses near Cormayeur.
The chase, which in early stages of human life was a necessity, has
become with advancing civilization not merely a passion but a
dilettanteism, and the cruel records of this pastime are among the most
discreditable pages in modern literature. It is true that in India and other
tropical countries, the number and ferocity of the wild beasts not only
justify but command a war of extermination against them, but the
indiscriminate slaughter of many quadrupeds which are favorite objects of
the chase can urge no such apology. Late official reports from India state
the number of human victims of the tiger, the leopard, the wolf and other
beasts of prey, in ten "districts," at more then twelve thousand within three
years, and we are informed on like authority that within the last six years
more than ten thousand men, women, and children have perished in the
same way in the Presidency of Bengal alone. One tiger, we are told, had
killed more than a hundred people, and finally stopped the travel on an
important road, and another had caused the desertion of thirteen villages
and thrown 250 square miles out of cultivation. In such facts we find
Page 144
abundant justification of the slaying of seven thousand tigers, nearly six
thousand leopards, and twenty-five hundred other ravenous beasts in the
Bengal Presidency, in the space of half a dozen years. But the humane
reader will not think the value of the flesh, the skin, and other less
important products of inoffensive quadrupeds a satisfactory excuse for the
ravages committed upon them by amateur sportsmen as well as by
professional hunters. In 1861, it was computed that the supply of the
English market with ivory cost the lives of 8,000 elephants. Others make
the number much larger and it is said that half as much ivory is consumed
in the United States as in Great Britain. In Ceylon, where the elephants are
numerous and destructive to the crops, as well as dangerous to travellers,
while their tusks are small and of comparatively little value, the government
pays a small reward for killing them. According to Sir Emerson Tennant,
[Footnote: Natural History of Ceylon, chap. iv.] in three years prior to 1848,
the premium was paid for 3,500 elephants in a part of the northern district,
and between 1851 and 1856 for 2,000 in the southern district. Major
Rogers, famous as an elephant shooter in Ceylon, ceased to count his
victims after he had slain 1,300, and Cumming in South Africa sacrificed
his hecatombs every month.
In spite of the rarity of the chamois, his cautious shyness, and the
comparative inaccessibility of his favorite haunts, Colani of Pontresina,
who died in 1837, had killed not less than 2,000 of these animals; Kung,
who is still living in the Upper Engadine, 1,500; Hitz, 1,300, and Zwichi an
equal number; Soldani shot 1,100 or 1,200 in the mountains which enclose
the Val Bregaglia, and there are many living hunters who can boast of
having killed from 500 to 800 of these interesting quadrupeds. [Footnote:
Although it is only in the severest cold of winter that the chamois descends
to the vicinity of grounds occupied by man, its organization does not
confine it to the mountains. In the royal park of Racconigi, on the plain a
few miles from Turin, at a height of less than 1,000 feet, is kept a herd of
thousand leopards, and twenty-five hundred other ravenous beasts in the
Bengal Presidency, in the space of half a dozen years. But the humane
reader will not think the value of the flesh, the skin, and other less
important products of inoffensive quadrupeds a satisfactory excuse for the
ravages committed upon them by amateur sportsmen as well as by
professional hunters. In 1861, it was computed that the supply of the
English market with ivory cost the lives of 8,000 elephants. Others make
the number much larger and it is said that half as much ivory is consumed
in the United States as in Great Britain. In Ceylon, where the elephants are
numerous and destructive to the crops, as well as dangerous to travellers,
while their tusks are small and of comparatively little value, the government
pays a small reward for killing them. According to Sir Emerson Tennant,
[Footnote: Natural History of Ceylon, chap. iv.] in three years prior to 1848,
the premium was paid for 3,500 elephants in a part of the northern district,
and between 1851 and 1856 for 2,000 in the southern district. Major
Rogers, famous as an elephant shooter in Ceylon, ceased to count his
victims after he had slain 1,300, and Cumming in South Africa sacrificed
his hecatombs every month.
In spite of the rarity of the chamois, his cautious shyness, and the
comparative inaccessibility of his favorite haunts, Colani of Pontresina,
who died in 1837, had killed not less than 2,000 of these animals; Kung,
who is still living in the Upper Engadine, 1,500; Hitz, 1,300, and Zwichi an
equal number; Soldani shot 1,100 or 1,200 in the mountains which enclose
the Val Bregaglia, and there are many living hunters who can boast of
having killed from 500 to 800 of these interesting quadrupeds. [Footnote:
Although it is only in the severest cold of winter that the chamois descends
to the vicinity of grounds occupied by man, its organization does not
confine it to the mountains. In the royal park of Racconigi, on the plain a
few miles from Turin, at a height of less than 1,000 feet, is kept a herd of
Page 145
thirty or forty chamois, which thrive and breed apparently as well as in the
Alps.]
In America, the chase of the larger quadrupeds is not less destructive. In a
late number of the American Naturalist, the present annual slaughter of the
bison is calculated at the enormous number of 500,000, and the elk, the
moose, the caribou, and the more familiar species of deer furnish, perhaps,
as many victims. The most fortunate deer-hunter I have personally known
in New England had killed but 960; but in the northern part of the State of
New York, a single sportsman is said to have shot 1,500, and this number
has been doubtless exceeded by zealous Nimrods of the West.
But so far as numbers are concerned, the statistics of the furtrade furnish
the most surprising results. Russia sends annually to foreign markets not
less than 20,000,000 squirrel skins, Great Britain has sometimes imported
from South America 600,000 nutria skins in a year. The Leipzig market
receives annually nearly 200,000 ermine, and the Hudson Bay Company is
said to have occasionally burnt 20,000 ermine skins in order that the market
might not be overstocked. Of course natural reproduction cannot keep pace
with this enormous destruction, and many animals of much interest to
natural science are in imminent danger of final extirpation. [Footnote:
Objectionable as game laws are, they have done something to prevent the
extinction of many quadrupeds, which naturalists would be loth to lose,
and, as in the case of the British ox, private parks and preserves have saved
other species from destruction. Some few wild aminals, such as the
American mink, for example, have been protected and bred with profit, and
in Pennsylvania an association of gentlemen has set apart, and is about
enclosing, a park of 16,000 acres for the breeding of indigenous quadrupeds
and fowls.]
Alps.]
In America, the chase of the larger quadrupeds is not less destructive. In a
late number of the American Naturalist, the present annual slaughter of the
bison is calculated at the enormous number of 500,000, and the elk, the
moose, the caribou, and the more familiar species of deer furnish, perhaps,
as many victims. The most fortunate deer-hunter I have personally known
in New England had killed but 960; but in the northern part of the State of
New York, a single sportsman is said to have shot 1,500, and this number
has been doubtless exceeded by zealous Nimrods of the West.
But so far as numbers are concerned, the statistics of the furtrade furnish
the most surprising results. Russia sends annually to foreign markets not
less than 20,000,000 squirrel skins, Great Britain has sometimes imported
from South America 600,000 nutria skins in a year. The Leipzig market
receives annually nearly 200,000 ermine, and the Hudson Bay Company is
said to have occasionally burnt 20,000 ermine skins in order that the market
might not be overstocked. Of course natural reproduction cannot keep pace
with this enormous destruction, and many animals of much interest to
natural science are in imminent danger of final extirpation. [Footnote:
Objectionable as game laws are, they have done something to prevent the
extinction of many quadrupeds, which naturalists would be loth to lose,
and, as in the case of the British ox, private parks and preserves have saved
other species from destruction. Some few wild aminals, such as the
American mink, for example, have been protected and bred with profit, and
in Pennsylvania an association of gentlemen has set apart, and is about
enclosing, a park of 16,000 acres for the breeding of indigenous quadrupeds
and fowls.]
Page 146
LARGE MARINE ANIMALS RELATIVELY UNIMPORTANT IN
GEOGRAPHY.
Vast as is the bulk of some of the higher orders of aquatic animals, their
remains are generally so perishable that, even where most abundant, they do
not appear to be now forming permanent deposits of any considerable
magnitude; but it is quite otherwise with shell-fish, and, as we shall see
hereafter, with many of the minute limeworkers of the sea. There are, on the
southern coast of the United States, beds of shells so extensive that they
were formerly supposed to have been naturally accumulated, and were
appealed to as proofs of an elevation of the coast by geological causes; but
they are now ascertained to have been derived chiefly from oysters and
other shell-fish, consumed in the course of long ages by the inhabitants of
Indian towns. The planting of a bed of oysters in a new locality might very
probably lead, in time, to the formation of a bank, which, in connection
with other deposits, might perceptibly affect the line of a coast, or, by
changing the course of marine currents, or the outlet of a river, produce
geographical changes of no small importance.
INTRODUCTION AND BREEDING OF FISH.
The introduction and successful breeding of fish or foreign species appears
to have been long practised in China, and was not unknown to the Greeks
and Romans. [Footnote: The observations of COLUMELLA, de Re Rustica,
lib. viii., sixteenth and following chapters, on fish-breeding, are interesting.
The Romans not only stocked natural but constructed artificial ponds, of
both fresh and salt water, and cut off bays of the sea for this purpose. They
also naturalized various species of sea-fish in fresh water.] This art has been
revived in modern times, but thus far without any important results,
economical or physical, though there seems to be good reason to believe it
may be employed with advantage on an extended scale. As in the case of
GEOGRAPHY.
Vast as is the bulk of some of the higher orders of aquatic animals, their
remains are generally so perishable that, even where most abundant, they do
not appear to be now forming permanent deposits of any considerable
magnitude; but it is quite otherwise with shell-fish, and, as we shall see
hereafter, with many of the minute limeworkers of the sea. There are, on the
southern coast of the United States, beds of shells so extensive that they
were formerly supposed to have been naturally accumulated, and were
appealed to as proofs of an elevation of the coast by geological causes; but
they are now ascertained to have been derived chiefly from oysters and
other shell-fish, consumed in the course of long ages by the inhabitants of
Indian towns. The planting of a bed of oysters in a new locality might very
probably lead, in time, to the formation of a bank, which, in connection
with other deposits, might perceptibly affect the line of a coast, or, by
changing the course of marine currents, or the outlet of a river, produce
geographical changes of no small importance.
INTRODUCTION AND BREEDING OF FISH.
The introduction and successful breeding of fish or foreign species appears
to have been long practised in China, and was not unknown to the Greeks
and Romans. [Footnote: The observations of COLUMELLA, de Re Rustica,
lib. viii., sixteenth and following chapters, on fish-breeding, are interesting.
The Romans not only stocked natural but constructed artificial ponds, of
both fresh and salt water, and cut off bays of the sea for this purpose. They
also naturalized various species of sea-fish in fresh water.] This art has been
revived in modern times, but thus far without any important results,
economical or physical, though there seems to be good reason to believe it
may be employed with advantage on an extended scale. As in the case of
Page 147
plants, man has sometimes undesignedly introduced now species of aquatic
animals into countries distant from their birthplace. The accidental escape
of the Chinese goldfish from ponds where they were bred as a garden
ornament, has peopled some European, and it is said American streams with
this species. Canals of navigation and irrigation interchange the fish of
lakes and rivers widely separated by natural barriers, as well as the plants
which drop their seeds into the waters. The Erie Canal, as measured by its
own channel, has a length of about three hundred and sixty miles, and it has
ascending and descending locks in both directions. By this route, the fresh-
water fish of the Hudson and the Upper Lakes, and some of the indigenous
vegetables of these respective basins, have intermixed, and the fauna and
flora of the two regions have now more species common to both than before
the canal was opened. [Footnote: The opening or rather the reconstruction
of the Claudian emissary by Prince Torlonia, designed to drain the Lake
Fucinus, or Celano, has introduced the fish of that lake into the Liri or
Garigliano which received the discharge from the lake.—Dorotea,
Sommario storico dell' Alieutica, p. 60.]The opening of the Suez Canal will,
no doubt, produce very interesting revolutions in the animal and vegetable
population of both basins. The Mediterranean, with some local exceptions
—such as the bays of Calabria, and the coast of Sicily so picturesquely
described by Quatrefages [Footnote: Souvenire d'un Naturaliste, i., pp. 204
et seqq.]-is comparatively poor in marine vegetation, and in shell as well as
in fin fish. The scarcity of fish in some of its gulfs is proverbial, and you
may scrutinize long stretches of beach on its northern shores, after every
south wind for a whole winter, without finding a dozen shells to reward
your search. But no one who has not looked down into tropical or
subtropical seas can conceive the amazing wealth of the Red Sea in organic
life. Its bottom is carpeted or paved with marine plants, with zoophytes and
with shells, while its waters are teeming with infinitely varied forms of
moving life. Most of its vegetables and its animals, no doubt, are confined
animals into countries distant from their birthplace. The accidental escape
of the Chinese goldfish from ponds where they were bred as a garden
ornament, has peopled some European, and it is said American streams with
this species. Canals of navigation and irrigation interchange the fish of
lakes and rivers widely separated by natural barriers, as well as the plants
which drop their seeds into the waters. The Erie Canal, as measured by its
own channel, has a length of about three hundred and sixty miles, and it has
ascending and descending locks in both directions. By this route, the fresh-
water fish of the Hudson and the Upper Lakes, and some of the indigenous
vegetables of these respective basins, have intermixed, and the fauna and
flora of the two regions have now more species common to both than before
the canal was opened. [Footnote: The opening or rather the reconstruction
of the Claudian emissary by Prince Torlonia, designed to drain the Lake
Fucinus, or Celano, has introduced the fish of that lake into the Liri or
Garigliano which received the discharge from the lake.—Dorotea,
Sommario storico dell' Alieutica, p. 60.]The opening of the Suez Canal will,
no doubt, produce very interesting revolutions in the animal and vegetable
population of both basins. The Mediterranean, with some local exceptions
—such as the bays of Calabria, and the coast of Sicily so picturesquely
described by Quatrefages [Footnote: Souvenire d'un Naturaliste, i., pp. 204
et seqq.]-is comparatively poor in marine vegetation, and in shell as well as
in fin fish. The scarcity of fish in some of its gulfs is proverbial, and you
may scrutinize long stretches of beach on its northern shores, after every
south wind for a whole winter, without finding a dozen shells to reward
your search. But no one who has not looked down into tropical or
subtropical seas can conceive the amazing wealth of the Red Sea in organic
life. Its bottom is carpeted or paved with marine plants, with zoophytes and
with shells, while its waters are teeming with infinitely varied forms of
moving life. Most of its vegetables and its animals, no doubt, are confined
Page 148
by the laws of their organization to a warmer temperature than that of the
Mediterranean, but among them there must be many whose habitat is of a
wider range, many whose powers of accommodation would enable them to
acclimate themselves in a colder sea.
We may suppose the less numerous aquatic fauna and flora of the
Mediterranean to be equally capable of climatic adaptation, and hence there
will be a partial interchange of the organic population not already common
to both seas. Destructive species, thus newly introduced, may diminish the
numbers of their proper prey in either basin, and, on the other hand, the
increased supply of appropriate food may greatly multiply the abundance of
others, and at the same time add important contributions to the aliment of
man in the countries bordering on the Mediterranean. [Footnote: The
dissolution of the salts in the bed of the Bitter Lake impregnated the water
admitted from the Red Sea so highly that for some time fish were not seen
in that basin. The flow of the current through the canal has now reduced the
proportion of saline matter to five per cent, and late travellers speak of fish
as abundant in its waters.]
Some accidental attraction not unfrequently induces fish to follow a
vessel for days in succession, and they may thus be enticed into zones very
distant from their native habitat. Several years ago, I was told at
Constantinople, upon good authority, that a couple of fish, of a species
wholly unknown to the natives had just been taken in the Bosphorus. They
were alleged to have followed an English ship from the Thames, and to
have been frequently observed by the crew during the passage; but I was
unable to learn their specific character. [Footnote: Seven or eight years ago,
the Italian government imported from France a dredging machine for use in
the harbor of La Spezia. The dredge brought attached to its hull a shell-fish
not known in Italian waters. The mollusk, finding the local circumstances
favorable, established itself in this new habitat, multiplied rapidly, and is
Mediterranean, but among them there must be many whose habitat is of a
wider range, many whose powers of accommodation would enable them to
acclimate themselves in a colder sea.
We may suppose the less numerous aquatic fauna and flora of the
Mediterranean to be equally capable of climatic adaptation, and hence there
will be a partial interchange of the organic population not already common
to both seas. Destructive species, thus newly introduced, may diminish the
numbers of their proper prey in either basin, and, on the other hand, the
increased supply of appropriate food may greatly multiply the abundance of
others, and at the same time add important contributions to the aliment of
man in the countries bordering on the Mediterranean. [Footnote: The
dissolution of the salts in the bed of the Bitter Lake impregnated the water
admitted from the Red Sea so highly that for some time fish were not seen
in that basin. The flow of the current through the canal has now reduced the
proportion of saline matter to five per cent, and late travellers speak of fish
as abundant in its waters.]
Some accidental attraction not unfrequently induces fish to follow a
vessel for days in succession, and they may thus be enticed into zones very
distant from their native habitat. Several years ago, I was told at
Constantinople, upon good authority, that a couple of fish, of a species
wholly unknown to the natives had just been taken in the Bosphorus. They
were alleged to have followed an English ship from the Thames, and to
have been frequently observed by the crew during the passage; but I was
unable to learn their specific character. [Footnote: Seven or eight years ago,
the Italian government imported from France a dredging machine for use in
the harbor of La Spezia. The dredge brought attached to its hull a shell-fish
not known in Italian waters. The mollusk, finding the local circumstances
favorable, established itself in this new habitat, multiplied rapidly, and is
Page 149
now found almost everywhere on the west coast of the Peninsula.] Many of
the fish which pass the greater part of the year in salt water spawn in fresh,
and some fresh-water species, the common brook-trout of New England for
instance, which under ordinary circumstances never visit the sea, will, if
transferred to brooks emptying directly into the ocean, go down into the salt
water after spawning-time, and return again the next season. Some sea fish
have been naturalized in fresh water, and naturalists have argued from the
character of the fish of Lake Baikal, and especially from the existence of
the seal in that locality, that all its inhabitants were originally marine
species, and have changed their habits with the gradual conversion of the
saline waters of the lake-once, as is assumed, a maritime bay-into fresh.
[Footnote: Babinet, Etudes et Lectures, ii, pp. 108,110.] The presence of the
seal is hardly conclusive on this point, for it is sometimes seen in Lake
Champlain at the distance of some hundreds of miles from even brackish
water. One of these animals was killed on the ice in that lake in February,
1810, another in February, 1846, [Footnote: Thompson, Natural History of
Vermont, p. 38, and Appendix, p. 18. There is no reason to believe that the
seal breeds in Lake Champlain, but the individual last taken there must have
been some weeks, at least, in its waters. It was killed on the ice in the
widest part of the lake, on the 23d of February, thirteen days after the
surface was entirely frozen, except the usual small cracks, and a month or
two after the ice closed at all points north of the place where the seal was
found.] and remains of the seal have been found at other times in the same
waters.
The intentional naturalization of foreign fish, as I have said, has not thus
far yielded important fruits; but though this particular branch of what is
called, not very happily, pisciculture, has not yet established its claims to
the attention of the physical geographer or the political economist, the
artificial breeding of domestic fish, of the lobster and other crustacea, has
already produced very valuable results, and is apparently destined to occupy
the fish which pass the greater part of the year in salt water spawn in fresh,
and some fresh-water species, the common brook-trout of New England for
instance, which under ordinary circumstances never visit the sea, will, if
transferred to brooks emptying directly into the ocean, go down into the salt
water after spawning-time, and return again the next season. Some sea fish
have been naturalized in fresh water, and naturalists have argued from the
character of the fish of Lake Baikal, and especially from the existence of
the seal in that locality, that all its inhabitants were originally marine
species, and have changed their habits with the gradual conversion of the
saline waters of the lake-once, as is assumed, a maritime bay-into fresh.
[Footnote: Babinet, Etudes et Lectures, ii, pp. 108,110.] The presence of the
seal is hardly conclusive on this point, for it is sometimes seen in Lake
Champlain at the distance of some hundreds of miles from even brackish
water. One of these animals was killed on the ice in that lake in February,
1810, another in February, 1846, [Footnote: Thompson, Natural History of
Vermont, p. 38, and Appendix, p. 18. There is no reason to believe that the
seal breeds in Lake Champlain, but the individual last taken there must have
been some weeks, at least, in its waters. It was killed on the ice in the
widest part of the lake, on the 23d of February, thirteen days after the
surface was entirely frozen, except the usual small cracks, and a month or
two after the ice closed at all points north of the place where the seal was
found.] and remains of the seal have been found at other times in the same
waters.
The intentional naturalization of foreign fish, as I have said, has not thus
far yielded important fruits; but though this particular branch of what is
called, not very happily, pisciculture, has not yet established its claims to
the attention of the physical geographer or the political economist, the
artificial breeding of domestic fish, of the lobster and other crustacea, has
already produced very valuable results, and is apparently destined to occupy
Page 150
an extremely conspicuous place in the history of man's efforts to
compensate his prodigal waste of the gifts of nature. The arrangements for
breeding fish in the Venetian lagoon of Comacchio date far back in the
Middle Ages, but the example does not seem to have been followed
elsewhere in Europe at that period, except in small ponds where the
propagation of the fish was left to nature without much artificial aid. The
transplantation of oysters to artificial ponds has long been common, and it
appears to have recently succeeded well on a large scale in the open sea on
the French coast. A great extension of this fishery is hoped for, and it is now
proposed to introduce upon the same coast the American soft clam, which is
so abundant in the tide-washed beach sands of Long Island Sound as to
form an important article in the diet of the neighboring population.
Experimental pisciculture has been highly successful in the United States,
and will probably soon become a regular branch of rural industry, especially
as Congress, at the session of 1871-2, made liberal provision for its
promotion.
The restoration of the primitive abundance of salt and fresh water fish, is
perhaps the greatest material benefit that, with our present physical
resources, governments can hope to confer upon their subjects. The rivers,
lakes, and seacoasts once restocked, and protected by law from exhaustion
by taking fish at improper seasons, by destructive methods, and in
extravagant quantities, would continue indefinitely to furnish a very large
supply of most healthful food, which, unlike all domestic and agricultural
products, would spontaneously renew itself and cost nothing but the taking.
There are many sterile or wornout soils in Europe so situated that they
might, at no very formidable cost, be converted into permanent lakes, which
would serve not only as reservoirs to retain the water of winter rains and
snow, and give it out in the dry season for irrigation, but as breeding ponds
for fish, and would thus, without further cost, yield a larger supply of
human food than can at present be obtained from them even at a great
compensate his prodigal waste of the gifts of nature. The arrangements for
breeding fish in the Venetian lagoon of Comacchio date far back in the
Middle Ages, but the example does not seem to have been followed
elsewhere in Europe at that period, except in small ponds where the
propagation of the fish was left to nature without much artificial aid. The
transplantation of oysters to artificial ponds has long been common, and it
appears to have recently succeeded well on a large scale in the open sea on
the French coast. A great extension of this fishery is hoped for, and it is now
proposed to introduce upon the same coast the American soft clam, which is
so abundant in the tide-washed beach sands of Long Island Sound as to
form an important article in the diet of the neighboring population.
Experimental pisciculture has been highly successful in the United States,
and will probably soon become a regular branch of rural industry, especially
as Congress, at the session of 1871-2, made liberal provision for its
promotion.
The restoration of the primitive abundance of salt and fresh water fish, is
perhaps the greatest material benefit that, with our present physical
resources, governments can hope to confer upon their subjects. The rivers,
lakes, and seacoasts once restocked, and protected by law from exhaustion
by taking fish at improper seasons, by destructive methods, and in
extravagant quantities, would continue indefinitely to furnish a very large
supply of most healthful food, which, unlike all domestic and agricultural
products, would spontaneously renew itself and cost nothing but the taking.
There are many sterile or wornout soils in Europe so situated that they
might, at no very formidable cost, be converted into permanent lakes, which
would serve not only as reservoirs to retain the water of winter rains and
snow, and give it out in the dry season for irrigation, but as breeding ponds
for fish, and would thus, without further cost, yield a larger supply of
human food than can at present be obtained from them even at a great
Page 151
expenditure of capital and labor in agricultural operations. [Footnote: See
Ackerhof, Die Nutzung der Seiche und Gewasser. Quedlinburg, 1860.] The
additions which might be made to the nutriment of the civilized world by a
judicious administration of the resources of the waters, would allow some
restriction of the amount of soil at present employed for agricultural
purposes, and a corresponding extension of the area of the forest, and would
thus facilitate a return to primitive geographical arrangements which it is
important partially to restore.
Destruction of Fish.
The inhabitants of the waters seem comparatively secure from human
pursuit or interference by the inaccessibility of their retreats, and by our
ignorance of their habits—a natural result of the difficulty of observing the
ways of creatures living in a medium in which we cannot exist. Human
agency has, nevertheless, both directly and incidentally, produced great
changes in the population of the sea, the lakes, and the rivers, and if the
effects of such revolutions in aquatic life are apparently of small importance
in general geography, they are still not wholly inappreciable. The great
diminution in the abundance of the larger fish employed for food or pursued
for products useful in the arts is familiar, and when we consider how the
vegetable and animal life on which they feed must be effected by the
reduction of their numbers, it is easy to see that their destruction may
involve considerable modifications in many of the material arrangements of
nature. The whale [Footnote: I use WHALE not in a technical sense, but as
a generic term for all the large inhabitants of the sea popularly grouped
under that name. The Greek kaetos and Latin Balaena, though sometimes,
especially in later classical writers, specifically applied to true cetaceans,
were generally much more comprehensive in their signification than the
modern word whale. This appears abundantly from the enumeration of the
Ackerhof, Die Nutzung der Seiche und Gewasser. Quedlinburg, 1860.] The
additions which might be made to the nutriment of the civilized world by a
judicious administration of the resources of the waters, would allow some
restriction of the amount of soil at present employed for agricultural
purposes, and a corresponding extension of the area of the forest, and would
thus facilitate a return to primitive geographical arrangements which it is
important partially to restore.
Destruction of Fish.
The inhabitants of the waters seem comparatively secure from human
pursuit or interference by the inaccessibility of their retreats, and by our
ignorance of their habits—a natural result of the difficulty of observing the
ways of creatures living in a medium in which we cannot exist. Human
agency has, nevertheless, both directly and incidentally, produced great
changes in the population of the sea, the lakes, and the rivers, and if the
effects of such revolutions in aquatic life are apparently of small importance
in general geography, they are still not wholly inappreciable. The great
diminution in the abundance of the larger fish employed for food or pursued
for products useful in the arts is familiar, and when we consider how the
vegetable and animal life on which they feed must be effected by the
reduction of their numbers, it is easy to see that their destruction may
involve considerable modifications in many of the material arrangements of
nature. The whale [Footnote: I use WHALE not in a technical sense, but as
a generic term for all the large inhabitants of the sea popularly grouped
under that name. The Greek kaetos and Latin Balaena, though sometimes,
especially in later classical writers, specifically applied to true cetaceans,
were generally much more comprehensive in their signification than the
modern word whale. This appears abundantly from the enumeration of the
Page 152
marine animals embraced by Oppian under the name <Greek: kaetos>, in
the first book of the Halieutica.
There is some confusion in Oppian's account of the fishery of the
<Greek: kaetos> in the fifth book of the Halieutica. Part of it is probably to
be understood of cetaceans which have GROUNDED, as some species
often do; but in general it evidently applies to the taking of large fish—
sharks, for example, as appear by the description of the teeth—with hook
and bait.] does not appear to have been an object of pursuit by the ancients,
for any purpose, nor do we know when the whale fishery first commenced.
It was, however, very actively prosecuted in the Middle Ages, and the
Biscayans seem to have been particularly successful in this as indeed in
other branches of nautical industry. [Footnote: From the narrative of Ohther,
introduced by King Alfred into his translation of Orosius, it is clear that the
Northmen pursued the whale fishery in the ninth century, and it appears,
both from the poem called The Whale, in the Codex Exoniensis, and from
the dialogue with the fisherman in the Colloquies of Aelfric, that the Anglo-
Saxons followed this dangerous chore at a period not much later. I am not
aware of any evidence to show that any of the Latin nationals engaged in
this fishery until a century or two afterward, though it may not be easy to
disprove their earlier participation in it. In mediaeval literature, Latin and
Romance, very frequent mention is made of a species of vessel called in
Latin baleneria, balenerium, balenerius, balaneria, etc.; in Catalan, balener;
in French, balenier; all of which words occur the many other forms. The
most obvious etymology of these words would suggest the meaning,
whaler, baleinier; but some have supposed that the name was descriptive of
the great size of the ships, and others have referred it to a different root.
From the fourteenth century, the word occurs oftener, perhaps, in old
Catalan, than in any other language; but Capmany does not notice the whale
fishery as one of the maritime pursuits of the very enterprising Catalan
people, nor do I find any of the products of the whale mentioned in the old
the first book of the Halieutica.
There is some confusion in Oppian's account of the fishery of the
<Greek: kaetos> in the fifth book of the Halieutica. Part of it is probably to
be understood of cetaceans which have GROUNDED, as some species
often do; but in general it evidently applies to the taking of large fish—
sharks, for example, as appear by the description of the teeth—with hook
and bait.] does not appear to have been an object of pursuit by the ancients,
for any purpose, nor do we know when the whale fishery first commenced.
It was, however, very actively prosecuted in the Middle Ages, and the
Biscayans seem to have been particularly successful in this as indeed in
other branches of nautical industry. [Footnote: From the narrative of Ohther,
introduced by King Alfred into his translation of Orosius, it is clear that the
Northmen pursued the whale fishery in the ninth century, and it appears,
both from the poem called The Whale, in the Codex Exoniensis, and from
the dialogue with the fisherman in the Colloquies of Aelfric, that the Anglo-
Saxons followed this dangerous chore at a period not much later. I am not
aware of any evidence to show that any of the Latin nationals engaged in
this fishery until a century or two afterward, though it may not be easy to
disprove their earlier participation in it. In mediaeval literature, Latin and
Romance, very frequent mention is made of a species of vessel called in
Latin baleneria, balenerium, balenerius, balaneria, etc.; in Catalan, balener;
in French, balenier; all of which words occur the many other forms. The
most obvious etymology of these words would suggest the meaning,
whaler, baleinier; but some have supposed that the name was descriptive of
the great size of the ships, and others have referred it to a different root.
From the fourteenth century, the word occurs oftener, perhaps, in old
Catalan, than in any other language; but Capmany does not notice the whale
fishery as one of the maritime pursuits of the very enterprising Catalan
people, nor do I find any of the products of the whale mentioned in the old
Page 153
Catalan tariffs. The WHALEBONE of the mediaeval writers, which is
described as very white, is doubtless the ivory of the walrus or of the
narwhale.] Five hundred years ago, whales abounded in every sea. They
long since became so rare in the Mediterranean as not to afford
encouragement for the fishery as a regular occupation; and the great
demand for oil and whalebone for mechanical and manufacturing purposes,
in the present century, has stimulated the pursuit of the "hugest of living
creatures" to such activity, that he has now almost wholly disappeared from
many favorite fishing grounds, and in others is greatly diminished in
numbers.
What special functions, besides his uses to man, are assigned to the
whale in the economy of nature, wo do not know; but some considerations,
suggested by the character of the food upon which certain species subsist,
deserve to be specially noticed. None of the great mammals grouped under
the general name of whale are rapacious. They all live upon small
organisms, and the most numerous species feed almost wholly upon thesoft
gelatinous mollusks in which the sea abounds in all latitudes. We cannot
calculate even approximately the number of the whales, or the quantity of
organic nutriment consumed by an individual, and of course we can form
no estimate of the total amount of animal matter withdrawn by them, in a
given period, from the waters of the sea. It is certain, however, that it must
have been enormous when they were more abundant, and that it is still very
considerable. In 1846 the United States had six hundred and seventy-eight
whaling ships chiefly employed in the Pacific, and the product of the
American whale fishery for the year ending June 1st, 1860, was seven
millions and a half of dollars. [Footnote: In consequence of the great
scarcity of the whale, the use of coal-gas for illumination, the substitution
of other fatty and oleaginous substances, such as lard, palm-oil, and
petroleum for right-whale oil and spermaceti, the whale fishery has rapidly
fallen off within a few years. The great supply of petroleum, which is much
described as very white, is doubtless the ivory of the walrus or of the
narwhale.] Five hundred years ago, whales abounded in every sea. They
long since became so rare in the Mediterranean as not to afford
encouragement for the fishery as a regular occupation; and the great
demand for oil and whalebone for mechanical and manufacturing purposes,
in the present century, has stimulated the pursuit of the "hugest of living
creatures" to such activity, that he has now almost wholly disappeared from
many favorite fishing grounds, and in others is greatly diminished in
numbers.
What special functions, besides his uses to man, are assigned to the
whale in the economy of nature, wo do not know; but some considerations,
suggested by the character of the food upon which certain species subsist,
deserve to be specially noticed. None of the great mammals grouped under
the general name of whale are rapacious. They all live upon small
organisms, and the most numerous species feed almost wholly upon thesoft
gelatinous mollusks in which the sea abounds in all latitudes. We cannot
calculate even approximately the number of the whales, or the quantity of
organic nutriment consumed by an individual, and of course we can form
no estimate of the total amount of animal matter withdrawn by them, in a
given period, from the waters of the sea. It is certain, however, that it must
have been enormous when they were more abundant, and that it is still very
considerable. In 1846 the United States had six hundred and seventy-eight
whaling ships chiefly employed in the Pacific, and the product of the
American whale fishery for the year ending June 1st, 1860, was seven
millions and a half of dollars. [Footnote: In consequence of the great
scarcity of the whale, the use of coal-gas for illumination, the substitution
of other fatty and oleaginous substances, such as lard, palm-oil, and
petroleum for right-whale oil and spermaceti, the whale fishery has rapidly
fallen off within a few years. The great supply of petroleum, which is much
Page 154
used for lubricating machinery as well as for numerous other purposes, has
produced a more perceptible effect on the whale fishery than any other
single circumstance. According to Bigelow, Les Etats-Unis en 1863, p. 346,
the American whaling fleet was diminished by 29 in 1858, 57 in 1860, 94 in
1861, and 65 in 1862. The number of American ships employed in that
fishery in 1862 was 353. In 1868, the American whaling fleet was reduced
to 223. The product of the whale fishery in that year was 1,485,000 gallons
of sperm oil, 2,065,612 gallons of train oil, and 901,000 pounds of
whalebone. The yield of the two species of whale is about the same, being
estimated at from 4,000 to 5,000 gallons for each fish. Taking the average at
4,500 gallons, the American whalers must have captured 789 whales,
besides, doubtless, many which were killed or mortally wounded and not
secured. The returns for the year are valued at about five million and a half
dollars. Mr. Cutts, from a report by whom most of the above facts are taken,
estimates the annual value of the "products of the sea" at $90,000,000.
According to the New Bedford Standard, the American whalers
numbered 722, measuring 230,218 tons, in 1846. On the 31st December,
1872, the number was reduced to 204, with a tonnage of 47,787 tons, and
the importation of whale and sperm oil amounted in that year to 79,000
barrels. Svend Foyn, an energetic Norwegian, now carries on the whale
fishery in the Arctic Ocean in a steamer of 20 horse-power, accompanied by
freight-ships for the oil. The whales are killed by explosive shells fired from
a small cannon. The number usually killed by Foyn is from 35 to 45 per
year.—The Commerce in the Products of the Sea, a report by Col. R. D.
Cutts, communicated to the U. S. Senate. Washington, 1872.] The mere
bulk of the whales destroyed in a single year by the American and the
European vessels engaged in this fishery would form an island of no
inconsiderable dimensions, and each one of those taken must have
consumed, in the course of his growth, many times his own weight of
mollusks. The destruction of the whales must have been followed by a
produced a more perceptible effect on the whale fishery than any other
single circumstance. According to Bigelow, Les Etats-Unis en 1863, p. 346,
the American whaling fleet was diminished by 29 in 1858, 57 in 1860, 94 in
1861, and 65 in 1862. The number of American ships employed in that
fishery in 1862 was 353. In 1868, the American whaling fleet was reduced
to 223. The product of the whale fishery in that year was 1,485,000 gallons
of sperm oil, 2,065,612 gallons of train oil, and 901,000 pounds of
whalebone. The yield of the two species of whale is about the same, being
estimated at from 4,000 to 5,000 gallons for each fish. Taking the average at
4,500 gallons, the American whalers must have captured 789 whales,
besides, doubtless, many which were killed or mortally wounded and not
secured. The returns for the year are valued at about five million and a half
dollars. Mr. Cutts, from a report by whom most of the above facts are taken,
estimates the annual value of the "products of the sea" at $90,000,000.
According to the New Bedford Standard, the American whalers
numbered 722, measuring 230,218 tons, in 1846. On the 31st December,
1872, the number was reduced to 204, with a tonnage of 47,787 tons, and
the importation of whale and sperm oil amounted in that year to 79,000
barrels. Svend Foyn, an energetic Norwegian, now carries on the whale
fishery in the Arctic Ocean in a steamer of 20 horse-power, accompanied by
freight-ships for the oil. The whales are killed by explosive shells fired from
a small cannon. The number usually killed by Foyn is from 35 to 45 per
year.—The Commerce in the Products of the Sea, a report by Col. R. D.
Cutts, communicated to the U. S. Senate. Washington, 1872.] The mere
bulk of the whales destroyed in a single year by the American and the
European vessels engaged in this fishery would form an island of no
inconsiderable dimensions, and each one of those taken must have
consumed, in the course of his growth, many times his own weight of
mollusks. The destruction of the whales must have been followed by a
Page 155
proportional increase of the organisms they feed upon, and if we had the
means of comparing the statistics of these humble forms of life, for even so
short a period as that between the years 1760 and 1860, we should find a
difference possibly sufficient to suggest an explanation of some phenomena
at present unaccounted for. For instance, as I have observed in another
work, [Footnote: The Origin and History of the English Language, &c., pp.
423, 424.] the phosphorescence of the sea was unknown to ancient writers,
or at least scarcely noticed by them, and even Homer—who, blind as
tradition makes him when he composed his epics, had seen, and marked, in
earlier life, all that the glorious nature of the Mediterranean and its coasts
discloses to unscientific observation—nowhere alludes to this most
beautiful and striking of maritime wonders. In the passage just referred to, I
have endeavored to explain the silence of ancient writers with respect to
this as well as other remarkable phenomena on psychological grounds; but
is it not possible that, in modern times, the animalculae which produce it
may have immensely multiplied, from the destruction of their natural
enemies by man, and hence that the gleam shot forth by their
decomposition, or by their living processes, is both more frequent and more
brilliant than in the days of classic antiquity?
Although the whale does not prey upon smaller creatures resembling
himself in form and habits, yet true fishes are extremely voracious, and
almost every tribe devours unsparingly the feebler species, and even the
spawn and young of its own. [Footnote: Two young pickerel, Gystes
fasciatus, five inches long, ate 128 minnows, an inch long, the first day they
were fed, 132 the second, and 150 the third.—Fifth Report of
Commissioners of Massachusetts for Introduction of Fish. 1871. p. 17.] The
enormous destruction of the shark [Footnote: The shark is pursued in all the
tropical and subtropical seas for its fins—for which there is a great demand
in China as an article of diet—its oil and other products. About 40,000 are
taken annually in the Indian Ocean and the contiguous seas. In the North
means of comparing the statistics of these humble forms of life, for even so
short a period as that between the years 1760 and 1860, we should find a
difference possibly sufficient to suggest an explanation of some phenomena
at present unaccounted for. For instance, as I have observed in another
work, [Footnote: The Origin and History of the English Language, &c., pp.
423, 424.] the phosphorescence of the sea was unknown to ancient writers,
or at least scarcely noticed by them, and even Homer—who, blind as
tradition makes him when he composed his epics, had seen, and marked, in
earlier life, all that the glorious nature of the Mediterranean and its coasts
discloses to unscientific observation—nowhere alludes to this most
beautiful and striking of maritime wonders. In the passage just referred to, I
have endeavored to explain the silence of ancient writers with respect to
this as well as other remarkable phenomena on psychological grounds; but
is it not possible that, in modern times, the animalculae which produce it
may have immensely multiplied, from the destruction of their natural
enemies by man, and hence that the gleam shot forth by their
decomposition, or by their living processes, is both more frequent and more
brilliant than in the days of classic antiquity?
Although the whale does not prey upon smaller creatures resembling
himself in form and habits, yet true fishes are extremely voracious, and
almost every tribe devours unsparingly the feebler species, and even the
spawn and young of its own. [Footnote: Two young pickerel, Gystes
fasciatus, five inches long, ate 128 minnows, an inch long, the first day they
were fed, 132 the second, and 150 the third.—Fifth Report of
Commissioners of Massachusetts for Introduction of Fish. 1871. p. 17.] The
enormous destruction of the shark [Footnote: The shark is pursued in all the
tropical and subtropical seas for its fins—for which there is a great demand
in China as an article of diet—its oil and other products. About 40,000 are
taken annually in the Indian Ocean and the contiguous seas. In the North
Page 156
Sea and the Arctic Ocean large numbers are annually caught. See MERK.
Waarenlexikon—a work of great accuracy and value (Leipzig, 1870), article
Haifisch.] the pike, the trout family, and other ravenous fish, as well as of
the fishing birds, the seal, and the otter, by man, would naturally have
occasioned a great increase in the weaker and more defenceless fish on
which they feed, had he not been as hostile to them also as to their
persecutors.
Destruction of Aquatic Animals.
It does not seem probable that man, with all his rapacity and all his
enginery, will succeed in totally extirpating any salt-water fish, but he has
already exterminated at least one marine warm-blooded animal—Steller's
sea cow—and the walrus, the sea lion, and other large amphibia, as well as
the principal fishing quadrupeds, are in imminent danger of extinction.
Steller's sea cow, Rhytina Stelleri, was first seen by Europeans in the year
1741, on Bering's Island. It was a huge amphibious mammal, weighing not
less than eight thousand pounds, and appears to have been confined
exclusively to the islands and coasts in the neighborhood of Bering's Strait.
Its flesh was very palatable, and the localities it frequented were easily
accessible from the Russian establishments in Kamtschatka. As soon as its
existence and character, and the abundance of fur animals in the same
waters, were made known to the occupants of those posts by the return of
the survivors of Bering's expedition, so active a chase was commenced
against the amphibia of that region, that, in the course of twenty-seven
years, the sea cow, described by Steller as extremely numerous in 1741, is
believed to have been completely extirpated, not a single individual having
been seen since the year 1768. The various tribes of seals [Footnote: The
most valuable variety of fur seal, formerly abundant in all cold latitudes, is
stated to have been completely exterminated in the Southern hemisphere,
Waarenlexikon—a work of great accuracy and value (Leipzig, 1870), article
Haifisch.] the pike, the trout family, and other ravenous fish, as well as of
the fishing birds, the seal, and the otter, by man, would naturally have
occasioned a great increase in the weaker and more defenceless fish on
which they feed, had he not been as hostile to them also as to their
persecutors.
Destruction of Aquatic Animals.
It does not seem probable that man, with all his rapacity and all his
enginery, will succeed in totally extirpating any salt-water fish, but he has
already exterminated at least one marine warm-blooded animal—Steller's
sea cow—and the walrus, the sea lion, and other large amphibia, as well as
the principal fishing quadrupeds, are in imminent danger of extinction.
Steller's sea cow, Rhytina Stelleri, was first seen by Europeans in the year
1741, on Bering's Island. It was a huge amphibious mammal, weighing not
less than eight thousand pounds, and appears to have been confined
exclusively to the islands and coasts in the neighborhood of Bering's Strait.
Its flesh was very palatable, and the localities it frequented were easily
accessible from the Russian establishments in Kamtschatka. As soon as its
existence and character, and the abundance of fur animals in the same
waters, were made known to the occupants of those posts by the return of
the survivors of Bering's expedition, so active a chase was commenced
against the amphibia of that region, that, in the course of twenty-seven
years, the sea cow, described by Steller as extremely numerous in 1741, is
believed to have been completely extirpated, not a single individual having
been seen since the year 1768. The various tribes of seals [Footnote: The
most valuable variety of fur seal, formerly abundant in all cold latitudes, is
stated to have been completely exterminated in the Southern hemisphere,
Page 157
and to be now found only on one or two small islands of the Aleutian group.
In 1867 more than 700,000 seal skins were imported into Great Britain, and
at least 600,000 seals are estimated to have been taken in 1870. These
numbers do not include the seals killed by the Esquimaux and other rude
tribes.] in the Northern and Southern Pacific, the walrus [Footnote: In 1868,
a few American ships engaged in the North Pacific whale fishery turned
their attention to the walrus, and took from 200 to 600 each. In 1869 other
whalers engaged in the same pursuit, and in 1870 the American fleet is
believed to have destroyed not less than fifty thousand of these animals.
They yield about twenty gallons of oil and four or five pounds of ivory
each.] and the sea otter, are already so reduced in numbers that they seem
destined soon to follow the sea cow, unless protected by legislation
stringent enough, and a police energetic enough, to repress the ardent
cupidity of their pursuers. The seals, the otter tribe, and many other
amphibia which feed almost exclusively upon fish, are extremely voracious,
and of course their destruction or numerical reduction must have favored
the multiplication of the species of fish principally preyed upon by them. I
have been assured by the keeper of several young seals that, if supplied at
frequent intervals, each seal would devour not less than fourteen pounds of
fish, or about a quarter of his own weight, in a day. A very intelligent and
observing hunter, who has passed a great part of his life in the forest, after
carefully watching the habits of the fresh-water otter of the North American
States, estimates their consumption of fish at about four pounds per day.
Man has promoted the multiplication of fish by making war on their brute
enemies, but he has by no means thereby compensated his own greater
destructiveness. [Footnote: According to Hartwig, the United Provinces of
Holland had, in 1618, three thousand herring busses, and nine thousand
vessels engaged in the transport of these fish to market. The whole number
of persons employed in the Dutch herring fishery was computed at 200,000.
In 1867 more than 700,000 seal skins were imported into Great Britain, and
at least 600,000 seals are estimated to have been taken in 1870. These
numbers do not include the seals killed by the Esquimaux and other rude
tribes.] in the Northern and Southern Pacific, the walrus [Footnote: In 1868,
a few American ships engaged in the North Pacific whale fishery turned
their attention to the walrus, and took from 200 to 600 each. In 1869 other
whalers engaged in the same pursuit, and in 1870 the American fleet is
believed to have destroyed not less than fifty thousand of these animals.
They yield about twenty gallons of oil and four or five pounds of ivory
each.] and the sea otter, are already so reduced in numbers that they seem
destined soon to follow the sea cow, unless protected by legislation
stringent enough, and a police energetic enough, to repress the ardent
cupidity of their pursuers. The seals, the otter tribe, and many other
amphibia which feed almost exclusively upon fish, are extremely voracious,
and of course their destruction or numerical reduction must have favored
the multiplication of the species of fish principally preyed upon by them. I
have been assured by the keeper of several young seals that, if supplied at
frequent intervals, each seal would devour not less than fourteen pounds of
fish, or about a quarter of his own weight, in a day. A very intelligent and
observing hunter, who has passed a great part of his life in the forest, after
carefully watching the habits of the fresh-water otter of the North American
States, estimates their consumption of fish at about four pounds per day.
Man has promoted the multiplication of fish by making war on their brute
enemies, but he has by no means thereby compensated his own greater
destructiveness. [Footnote: According to Hartwig, the United Provinces of
Holland had, in 1618, three thousand herring busses, and nine thousand
vessels engaged in the transport of these fish to market. The whole number
of persons employed in the Dutch herring fishery was computed at 200,000.
Page 158
In the latter part of the eighteenth century, this fishery was most
successfully prosecuted by the Swedes, and in 1781, the town of
Gottenburg alone exported 136,649 barrels, each containing 1,200 herrings,
making a total of about 164,000,000; but so rapid was the exhaustion of the
fish, from this keen pursuit, that in 1799 it was found necessary to prohibit
the exportation of them altogether.—Das Leben des Meeres, p. 182.
In 1855, the British fisheries produced 900,000 barrels, or almost enough
to supply a fish to every human inhabitant of the globe.
On the shores of Long Island Sound, the white fish, a species of herring
too bony to be easily eaten, is used as manure in very great quantities. Ten
thousand are employed as a dressing for an acre, and a single net has
sometimes taken 200,000 in a day.—Dwight's Travels, ii. pp. 512, 515. The
London Times of May 11, 1872, informs us that 1,100 tons of mackerel
estimated to weigh one pound each had recently been taken in a single night
at a fishing station on the British coast.
About ten million eels are sold annually in Billingsgate market, but
vastly greater numbers of the young fry, when but three or four inches long,
are taken. So abundant are they at the mouths of many French and English
rivers, that they are carried into the country by cart-loads, and not only
eaten, but given to swine or used as manure.] The bird and beast of prey,
whether on land or in the water, hunt only as long as they feel the stimulus
of hunger, their ravages are limited by the demands of present appetite, and
they do not wastefully destroy what they cannot consume. Man, on the
contrary, angles to-day that he may dine to-morrow; he takes and dries
millions of fish on the banks of Newfoundland and the coast of Norway,
that the fervent Catholic of the shores of the Mediterranean may have
wherewithal to satisfy the cravings of the stomach during next year's Lent,
without violating the discipline of the papal church; [Footnote: The fisheries
successfully prosecuted by the Swedes, and in 1781, the town of
Gottenburg alone exported 136,649 barrels, each containing 1,200 herrings,
making a total of about 164,000,000; but so rapid was the exhaustion of the
fish, from this keen pursuit, that in 1799 it was found necessary to prohibit
the exportation of them altogether.—Das Leben des Meeres, p. 182.
In 1855, the British fisheries produced 900,000 barrels, or almost enough
to supply a fish to every human inhabitant of the globe.
On the shores of Long Island Sound, the white fish, a species of herring
too bony to be easily eaten, is used as manure in very great quantities. Ten
thousand are employed as a dressing for an acre, and a single net has
sometimes taken 200,000 in a day.—Dwight's Travels, ii. pp. 512, 515. The
London Times of May 11, 1872, informs us that 1,100 tons of mackerel
estimated to weigh one pound each had recently been taken in a single night
at a fishing station on the British coast.
About ten million eels are sold annually in Billingsgate market, but
vastly greater numbers of the young fry, when but three or four inches long,
are taken. So abundant are they at the mouths of many French and English
rivers, that they are carried into the country by cart-loads, and not only
eaten, but given to swine or used as manure.] The bird and beast of prey,
whether on land or in the water, hunt only as long as they feel the stimulus
of hunger, their ravages are limited by the demands of present appetite, and
they do not wastefully destroy what they cannot consume. Man, on the
contrary, angles to-day that he may dine to-morrow; he takes and dries
millions of fish on the banks of Newfoundland and the coast of Norway,
that the fervent Catholic of the shores of the Mediterranean may have
wherewithal to satisfy the cravings of the stomach during next year's Lent,
without violating the discipline of the papal church; [Footnote: The fisheries
Page 159
of Sicily alone are said to yield 20,000 tons of tunny a year. The tunny is
principally consumed in Italy during Lent, and a large proportion of the
twenty millions of codfish taken annually at the Lofoden fishery on the
coast of Norway is exported to the Mediterranean.] and all the arrangements
of his fisheries are so organized as to involve the destruction of many more
fish than are secured for human use, and the loss of a large proportion of the
annual harvest of the sea in the process of curing, or in transportation to the
places of its consumption. [Footnote According to Berthelote, in the Gulf of
Lyons, between Marseilles and the easternmost spur of the Pyrenees, about
5,000,000 small fish ate taken annually with the drag-net, and not lees than
twice as many more, not to spekak of spawn, are destroyed by the use of
this act.
Between 1861 and 1865 France imported from Norway, for use as bait in
the Sardine fishery, cod-roes to the value of three million francs.—Cutts,
Report on Commerce in the Products of the Sea, 1872, p. 82.
The most reckless waste of aquatic life I remember to have seen noticed,
if we except the destruction of herring and other fish with upawn, is that of
the eggs of the turtle in the Amazon for the sake of the oil extracted from
then. Bates estimates the eggs thus annually sacrificed at 48,000,000.-
Naturalits inthe Amazon, 2d edition, 1864, p. 805.] Fish are more affected
than quadrupeds by slight and even imperceptible differences in their
breeding places and feeding grounds. Every river, every brook, every lake
stamps a special character upon its salmon, its shad, and its trout, which is
at once recognized by those who deal in or consume them. No skill can give
the fish fattened by food selected and prepared by man the flavor of those
which are nourished at the table of nature, and the trout of the artificial
pouds in Germany and Switzerland are so inferior to the brook-fish of the
same species and climate, that it is hard to believe them identical. The
superior sapidity of the American trout and other fresh-water fishes to the
principally consumed in Italy during Lent, and a large proportion of the
twenty millions of codfish taken annually at the Lofoden fishery on the
coast of Norway is exported to the Mediterranean.] and all the arrangements
of his fisheries are so organized as to involve the destruction of many more
fish than are secured for human use, and the loss of a large proportion of the
annual harvest of the sea in the process of curing, or in transportation to the
places of its consumption. [Footnote According to Berthelote, in the Gulf of
Lyons, between Marseilles and the easternmost spur of the Pyrenees, about
5,000,000 small fish ate taken annually with the drag-net, and not lees than
twice as many more, not to spekak of spawn, are destroyed by the use of
this act.
Between 1861 and 1865 France imported from Norway, for use as bait in
the Sardine fishery, cod-roes to the value of three million francs.—Cutts,
Report on Commerce in the Products of the Sea, 1872, p. 82.
The most reckless waste of aquatic life I remember to have seen noticed,
if we except the destruction of herring and other fish with upawn, is that of
the eggs of the turtle in the Amazon for the sake of the oil extracted from
then. Bates estimates the eggs thus annually sacrificed at 48,000,000.-
Naturalits inthe Amazon, 2d edition, 1864, p. 805.] Fish are more affected
than quadrupeds by slight and even imperceptible differences in their
breeding places and feeding grounds. Every river, every brook, every lake
stamps a special character upon its salmon, its shad, and its trout, which is
at once recognized by those who deal in or consume them. No skill can give
the fish fattened by food selected and prepared by man the flavor of those
which are nourished at the table of nature, and the trout of the artificial
pouds in Germany and Switzerland are so inferior to the brook-fish of the
same species and climate, that it is hard to believe them identical. The
superior sapidity of the American trout and other fresh-water fishes to the
Page 160
most nearly corresponding European species, which is familiar to every one
acquainted with both continents, is probably due less to specific difference
than to the fact that, even in the parts of the New World which have been
longest cultivated, wild nature is not yet tamed down to the character it has
assumed in the Old, and which it will acquire in America also when her
civilization shall be as ancient as is now that of Europe. [Footnote: It is
possible that time may modify the habits of the fresh-water fish the North
American States, and accommodate them to the new physical conditions of
their native waters. Hence it may be hoped that nature, even unaided by art,
will do something towards restoring the ancient plenty of our lakes and
rivers. The decrease of our fresh-water fish cannot be alone to exhaustion
by fishing, for in the waters of the valleys and flanks of the Alps, which
have been inhabited and fished ten times as long by a denser population,
fish are still very abundant, and they thrive and multiply under
circumstances where no American species could live at all. On the southern
slope of those mountains, trout are caught in great numbers, in the swift
streams which rush from the glaciers, and where the water is of icy
coldness, and so turbid with particles of fine-ground rock, that you cannot
see an inch below the surface. The glacier streams of Switzerland, however,
are less abundant in fish.]
Man has hitherto hardly anywhere produced such climatic or other
changes as would suffice of themselves totally to banish the wild
inhabitants of the dry land, and thedisappearance of the native birds and
quadrupeds from particular localities is to be ascribed quite as much to his
direct persecutions as to the want of forest shelter, of appropriate food, or of
other conditions indispensable to their existence. But almost all the
processes of agriculture, and of mechanical and chemical industry, are
fatally destructive to aquatic animals within reach of their influence. When,
in consequence of clearing the woods, the changes already described as
thereby produced in the beds and currents of rivers, are in progress, the
acquainted with both continents, is probably due less to specific difference
than to the fact that, even in the parts of the New World which have been
longest cultivated, wild nature is not yet tamed down to the character it has
assumed in the Old, and which it will acquire in America also when her
civilization shall be as ancient as is now that of Europe. [Footnote: It is
possible that time may modify the habits of the fresh-water fish the North
American States, and accommodate them to the new physical conditions of
their native waters. Hence it may be hoped that nature, even unaided by art,
will do something towards restoring the ancient plenty of our lakes and
rivers. The decrease of our fresh-water fish cannot be alone to exhaustion
by fishing, for in the waters of the valleys and flanks of the Alps, which
have been inhabited and fished ten times as long by a denser population,
fish are still very abundant, and they thrive and multiply under
circumstances where no American species could live at all. On the southern
slope of those mountains, trout are caught in great numbers, in the swift
streams which rush from the glaciers, and where the water is of icy
coldness, and so turbid with particles of fine-ground rock, that you cannot
see an inch below the surface. The glacier streams of Switzerland, however,
are less abundant in fish.]
Man has hitherto hardly anywhere produced such climatic or other
changes as would suffice of themselves totally to banish the wild
inhabitants of the dry land, and thedisappearance of the native birds and
quadrupeds from particular localities is to be ascribed quite as much to his
direct persecutions as to the want of forest shelter, of appropriate food, or of
other conditions indispensable to their existence. But almost all the
processes of agriculture, and of mechanical and chemical industry, are
fatally destructive to aquatic animals within reach of their influence. When,
in consequence of clearing the woods, the changes already described as
thereby produced in the beds and currents of rivers, are in progress, the
Page 161
spawning grounds of fish, are exposed from year to year to a succession of
mechanical disturbances; the temperature of the water is higher in summer,
colder in winter, than when it was shaded and protected by wood; the
smaller organisms, which formed the sustenance of the young fry, disappear
or are reduced in numbers, and new enemies are added to the old foes that
preyed upon them; the increased turbidness of the water in the annual
inundations chokes the fish; and, finally, the quickened velocity of its
current sweeps them down into the larger rivers or into the sea, before they
are yet strong enough to support so great a change of circumstances.
[Footnote: A fact mentioned by Schubert—and which in its causes and
many of its results corresponds almost precisely with those connected with
the escape of Barton Pond in Vermont, so well known to geological students
—is important, as showing that the diminution of the fish in rivers exposed
to inundations is chiefly to be ascribed to the mechanical action of the
current, and not mainly, as some have supposed, to changes of temperature
occasioned by clearing.
Our author states that, in 1796, a terrible inundation was produced in the
Indalself, which rises in the Storsjo in Jemtland, by drawing off into it the
waters of another lake near Ragunda. The flood destroyed houses and
fields; much earth was swept into the channel, and the water made turbid
and muddy; the salmon and the smaller fish forsook the river altogether, and
never returned. The banks of the river have never regained their former
solidity, and portions of their soil are still continually falling into the water
and destroying its purity.—Resa genom Sverge, ii, p. 61.] Industrial
operations are not less destructive to fish which live or spawn in fresh
water. Mill-dams impede their migrations, if they do not absolutely prevent
them, the sawdust from lumber mills clogs their gills, and the thousand
deleterious mineral substances, discharged into rivers from metallurgical,
chemical, and manufacturing establishments, poison them by shoals.
[Footnote: The mineral water discharged from a colliery on the river Doon
mechanical disturbances; the temperature of the water is higher in summer,
colder in winter, than when it was shaded and protected by wood; the
smaller organisms, which formed the sustenance of the young fry, disappear
or are reduced in numbers, and new enemies are added to the old foes that
preyed upon them; the increased turbidness of the water in the annual
inundations chokes the fish; and, finally, the quickened velocity of its
current sweeps them down into the larger rivers or into the sea, before they
are yet strong enough to support so great a change of circumstances.
[Footnote: A fact mentioned by Schubert—and which in its causes and
many of its results corresponds almost precisely with those connected with
the escape of Barton Pond in Vermont, so well known to geological students
—is important, as showing that the diminution of the fish in rivers exposed
to inundations is chiefly to be ascribed to the mechanical action of the
current, and not mainly, as some have supposed, to changes of temperature
occasioned by clearing.
Our author states that, in 1796, a terrible inundation was produced in the
Indalself, which rises in the Storsjo in Jemtland, by drawing off into it the
waters of another lake near Ragunda. The flood destroyed houses and
fields; much earth was swept into the channel, and the water made turbid
and muddy; the salmon and the smaller fish forsook the river altogether, and
never returned. The banks of the river have never regained their former
solidity, and portions of their soil are still continually falling into the water
and destroying its purity.—Resa genom Sverge, ii, p. 61.] Industrial
operations are not less destructive to fish which live or spawn in fresh
water. Mill-dams impede their migrations, if they do not absolutely prevent
them, the sawdust from lumber mills clogs their gills, and the thousand
deleterious mineral substances, discharged into rivers from metallurgical,
chemical, and manufacturing establishments, poison them by shoals.
[Footnote: The mineral water discharged from a colliery on the river Doon
Page 162
in Scotland discolored the stones in the bed of the river, and killed the fish
for twenty miles below. The fish of the streams in which hemp is macerated
in Italy are often poisoned by the juices thus extracted from the plant.-
Dorotea, Sommario della storia dell' Alieutica, pp. 64, 65.] We have little
evidence that any fish employed as human food has naturally multiplied in
modern times, while all the more valuable tribes have been immensely
reduced in numbers. This reduction must have affected the more voracious
species not used as food by man, and accordingly the shark, and other fish
of similar habits, even when not objects of systematic pursuit, are now
comparatively rare in many waters where they formerly abounded. The
result is, that man has greatly reduced thenumbers of all larger marine
animals, and consequently indirectly favored the multiplication of the
smaller aquatic organisms which entered into their nutriment. This change
in the relations of the organic and inorganic matter of the sea must have
excercised an influence on the latter. What that influence has been we
cannot say, still less can we predict what it will be hereafter; but its action is
not for that reason the less certain. [Footnote: Among the unexpected results
of human action, the destruction or multiplication of fish, as well as of other
animals, is a not unfrequent occurrence. Footnote: Williams, in his History
of Vermont, i., p. 140, records such a case of the increase of trout. In a pond
formed by damming a small stream to obtain water power for a sawmill,
and covering one thousand acres of primitive forest, the increased supply of
food brought within reach of the fish multiplied them to that degree, that, at
the head of the pond, where, in the spring, they crowded together in the
brook which supplied it, they were taken by the hands at pleasure, and
swine caught them without difficulty. A single sweep of a small scoopnet
would bring up half a bushel, carts were filled with them as fast as if picked
up on dry land, and in the fishing season they were commonly sold at a
shilling (eightpence halfpenny, or about seventeen cents) a bushel. The
for twenty miles below. The fish of the streams in which hemp is macerated
in Italy are often poisoned by the juices thus extracted from the plant.-
Dorotea, Sommario della storia dell' Alieutica, pp. 64, 65.] We have little
evidence that any fish employed as human food has naturally multiplied in
modern times, while all the more valuable tribes have been immensely
reduced in numbers. This reduction must have affected the more voracious
species not used as food by man, and accordingly the shark, and other fish
of similar habits, even when not objects of systematic pursuit, are now
comparatively rare in many waters where they formerly abounded. The
result is, that man has greatly reduced thenumbers of all larger marine
animals, and consequently indirectly favored the multiplication of the
smaller aquatic organisms which entered into their nutriment. This change
in the relations of the organic and inorganic matter of the sea must have
excercised an influence on the latter. What that influence has been we
cannot say, still less can we predict what it will be hereafter; but its action is
not for that reason the less certain. [Footnote: Among the unexpected results
of human action, the destruction or multiplication of fish, as well as of other
animals, is a not unfrequent occurrence. Footnote: Williams, in his History
of Vermont, i., p. 140, records such a case of the increase of trout. In a pond
formed by damming a small stream to obtain water power for a sawmill,
and covering one thousand acres of primitive forest, the increased supply of
food brought within reach of the fish multiplied them to that degree, that, at
the head of the pond, where, in the spring, they crowded together in the
brook which supplied it, they were taken by the hands at pleasure, and
swine caught them without difficulty. A single sweep of a small scoopnet
would bring up half a bushel, carts were filled with them as fast as if picked
up on dry land, and in the fishing season they were commonly sold at a
shilling (eightpence halfpenny, or about seventeen cents) a bushel. The
Page 163
increase in the size of the trout was as remarkable as the multiplication of
their numbers.
The construction of dams and mills is destructive to many fish, but
operates as a protection to their prey. The mills on Connecticut River
greatly diminished the number of the salmon, but the striped bass, on which
the salmon feeds, multiplied in proportion.—Dr. Dwight, Travels, vol. ii., p.
323.]
Geographical Importance of Birds.
Wild birds form of themselves a very conspicuous and interesting feature
in the staffage, as painters call it, of the natural landscape, and they are
important elements in the view we are taking of geography, whether we
consider their immediate or their incidental influence. Birds affect
vegetation directly by sowing seeds and by consuming them; they affect it
indirectly by destroying insects injurious, or, in some cases, beneficial to
vegetable life. Hence, when we kill a seed-sowing bird, we check the
dissemination of a plant; when we kill a bird which digests the seed it
swallows, we promote the increase of a vegetable. Nature protects the seeds
of wild, much more effectually than those of domesticated plants. The
cereal grains are completely digested when consumed by birds, but the
germ of the smaller stone fruits and of very many other wild vegetables is
uninjured, perhaps even stimulated to more vigorous growth, by the natural
chemistry of the bird's stomach. The power of flight and the restless habits
of the bird enable it to transport heavy seeds to far greater distances than
they could be carried by the wind. A swift-winged bird may drop cherry
stones a thousand miles from the tree they grow on; a hawk, in tearing a
pigeon, may scatter from its crop the still fresh rice it had swallowed at a
distance of ten degrees of latitude, and thus the occurrence of isolated plants
in situations where their presence cannot otherwise well be explained, is
their numbers.
The construction of dams and mills is destructive to many fish, but
operates as a protection to their prey. The mills on Connecticut River
greatly diminished the number of the salmon, but the striped bass, on which
the salmon feeds, multiplied in proportion.—Dr. Dwight, Travels, vol. ii., p.
323.]
Geographical Importance of Birds.
Wild birds form of themselves a very conspicuous and interesting feature
in the staffage, as painters call it, of the natural landscape, and they are
important elements in the view we are taking of geography, whether we
consider their immediate or their incidental influence. Birds affect
vegetation directly by sowing seeds and by consuming them; they affect it
indirectly by destroying insects injurious, or, in some cases, beneficial to
vegetable life. Hence, when we kill a seed-sowing bird, we check the
dissemination of a plant; when we kill a bird which digests the seed it
swallows, we promote the increase of a vegetable. Nature protects the seeds
of wild, much more effectually than those of domesticated plants. The
cereal grains are completely digested when consumed by birds, but the
germ of the smaller stone fruits and of very many other wild vegetables is
uninjured, perhaps even stimulated to more vigorous growth, by the natural
chemistry of the bird's stomach. The power of flight and the restless habits
of the bird enable it to transport heavy seeds to far greater distances than
they could be carried by the wind. A swift-winged bird may drop cherry
stones a thousand miles from the tree they grow on; a hawk, in tearing a
pigeon, may scatter from its crop the still fresh rice it had swallowed at a
distance of ten degrees of latitude, and thus the occurrence of isolated plants
in situations where their presence cannot otherwise well be explained, is
Page 164
easily accounted for. [Footnote: Pigeons were shot near Albany, in New
York, a few years ago, with green rice in their crops, which it was thought
must have been growing, a very few hours before, at the distance of seven
or eight hundred miles. The efforts of the Dutch to confine the cultivation of
the nutmeg to the island of Banda are said to have been defeated by the
birds, which transported this heavy fruit to other islands.] There is a large
class of seeds apparently specially fitted by nature for dissemination by
animals. I refer to those which attach themselves, by means of hooks, or by
viscous juices, to the coats of quadrupeds and the feathers of birds, and are
thus transported wherever their living vehicles may chance to wander. Some
birds, too, deliberately bury seeds in the earth, or in holes excavated by
them in the bark of trees, not indeed with a foresight aiming directly at the
propagation of the plant, but from apparently purposeless secretiveness, or
as a mode of preserving food for future use.
The tame fowls play a much less conspicuous part in rural life than the
quadrupeds, and, in their relations to the economy of nature, they are of
very much less moment than four-footed animals, or than the
undomesticated birds. The domestic turkey [Footnote: The wild turkey
takes readily to the water, and is able to cross rivers of very considerable
width by swimming. By way of giving me an idea of the former abundance
of this bird, an old and highly respectable gentleman who was among the
early white settlers of the West, told me that he once counted, in walking
down the northern bank of the Ohio River, within a distance of four miles,
eighty-four turkeys as they landed singly, or at most in pairs, after
swimming over from the Kentucky side.] is probably more numerous in the
territory of the United States than the wild bird of the same species ever
was, and the grouse cannot, at the period of their greatest abundance, have
counted as many as we now number of the common hen. The dove,
however, must fall greatly short of the wild pigeon in multitude, and it is
hardly probable that the flocks of domestic geese and ducks are as
York, a few years ago, with green rice in their crops, which it was thought
must have been growing, a very few hours before, at the distance of seven
or eight hundred miles. The efforts of the Dutch to confine the cultivation of
the nutmeg to the island of Banda are said to have been defeated by the
birds, which transported this heavy fruit to other islands.] There is a large
class of seeds apparently specially fitted by nature for dissemination by
animals. I refer to those which attach themselves, by means of hooks, or by
viscous juices, to the coats of quadrupeds and the feathers of birds, and are
thus transported wherever their living vehicles may chance to wander. Some
birds, too, deliberately bury seeds in the earth, or in holes excavated by
them in the bark of trees, not indeed with a foresight aiming directly at the
propagation of the plant, but from apparently purposeless secretiveness, or
as a mode of preserving food for future use.
The tame fowls play a much less conspicuous part in rural life than the
quadrupeds, and, in their relations to the economy of nature, they are of
very much less moment than four-footed animals, or than the
undomesticated birds. The domestic turkey [Footnote: The wild turkey
takes readily to the water, and is able to cross rivers of very considerable
width by swimming. By way of giving me an idea of the former abundance
of this bird, an old and highly respectable gentleman who was among the
early white settlers of the West, told me that he once counted, in walking
down the northern bank of the Ohio River, within a distance of four miles,
eighty-four turkeys as they landed singly, or at most in pairs, after
swimming over from the Kentucky side.] is probably more numerous in the
territory of the United States than the wild bird of the same species ever
was, and the grouse cannot, at the period of their greatest abundance, have
counted as many as we now number of the common hen. The dove,
however, must fall greatly short of the wild pigeon in multitude, and it is
hardly probable that the flocks of domestic geese and ducks are as
Page 165
numerous as once wore those of their wild congeners. The pigeon, indeed,
seems to have multiplied immensely, for some years after the first clearings
in the woods, because the settlers warred unsparingly upon the hawk, while
the crops of grain and other vegetable growths increased the supply of food
within the reach of the young birds, at the age when their power of flight is
not yet great enough to enable them to seek it over a wide area. [Footnote:
The wood-pigeon, as well as the domestic dove, has been observed to
increase in numbers in Europe also, when pains have been taken to
exterminate the hawk. The American pigeons, which migrated in flocks so
numerous that they were whole days in passing a given point, were no
doubt injurious to the grain, but probably less so than is generally supposed;
for they did not confine themselves exclusively to the harvests for their
nourishment. ] The pigeon is not described by the earliest white inhabitants
of the American States as filling the air with such clouds of winged life as
astonished naturalists in the descriptions of Audubon, and, at the present
day, the net and the gun have so reduced its abundance, that its appearance
in large numbers is recorded only at long intervals, and it is never seen in
the great flocks remembered by many still living observers as formerly very
common.
INTRODUCTION OF BIRDS.
Man has undesignedly introduced into now districts perhaps fewer species
of birds than of quadrupeds; [Footnote: The first mention I have found of
the naturalization of a wild bird in modern Europe is in the Menagiana, vol.
iii., p. 174, edition of 1715, where it is stated that Rene, King of Sicily and
Duke of Anjou, who died in 1480, introduced the red-legged partridge into
the latter country. Attempts have been made, and I believe with success, to
naturalize the European lark on Long Island, and the English sparrow has
been introduced into various parts of the Northern States, where he is useful
seems to have multiplied immensely, for some years after the first clearings
in the woods, because the settlers warred unsparingly upon the hawk, while
the crops of grain and other vegetable growths increased the supply of food
within the reach of the young birds, at the age when their power of flight is
not yet great enough to enable them to seek it over a wide area. [Footnote:
The wood-pigeon, as well as the domestic dove, has been observed to
increase in numbers in Europe also, when pains have been taken to
exterminate the hawk. The American pigeons, which migrated in flocks so
numerous that they were whole days in passing a given point, were no
doubt injurious to the grain, but probably less so than is generally supposed;
for they did not confine themselves exclusively to the harvests for their
nourishment. ] The pigeon is not described by the earliest white inhabitants
of the American States as filling the air with such clouds of winged life as
astonished naturalists in the descriptions of Audubon, and, at the present
day, the net and the gun have so reduced its abundance, that its appearance
in large numbers is recorded only at long intervals, and it is never seen in
the great flocks remembered by many still living observers as formerly very
common.
INTRODUCTION OF BIRDS.
Man has undesignedly introduced into now districts perhaps fewer species
of birds than of quadrupeds; [Footnote: The first mention I have found of
the naturalization of a wild bird in modern Europe is in the Menagiana, vol.
iii., p. 174, edition of 1715, where it is stated that Rene, King of Sicily and
Duke of Anjou, who died in 1480, introduced the red-legged partridge into
the latter country. Attempts have been made, and I believe with success, to
naturalize the European lark on Long Island, and the English sparrow has
been introduced into various parts of the Northern States, where he is useful
Page 166
by destroying noxious insects and worms not preyed upon by native birds.
The humming-bird has resisted all efforts to acclimate him in Europe,
though they have not unfrequently survived the passage across the ocean. In
Switzerland and some other parts of Europe the multiplication of
insectivorous birds is encouraged by building nests for them, and it is
alleged that both fruit and forest trees have been essentially benefited by the
protection thus afforded them.] but the distribution of birds is very much
influenced by the character of his industry, and the transplantation, of every
object of agricultural production is, at a longer or shorter interval, followed
by that of the birds which feed upon its seeds, or more frequently upon the
insects it harbors. The vulture, the crow, and other winged scavengers,
follow the march of armies as regularly as the wolf. Birds accompany ships
on long voyages, for the sake of the offal which is thrown overboard, and,
in such cases, it might often happen that they would breed and become
naturalized in countries where they had been unknown before. [Footnote:
Gulls hover about ships in port, and often far out at sea, diligently watching
for the waste of the caboose. While the four great fleets, English, French,
Turkish, and Egyptian, were lying in the Bosphorus, in the summer and
autumn of 1853, a young lady of my family called my attention to the fact
that the gulls were far more numerous about the ships of one of the fleets
than about the others. This was verified by repeated observation, and the
difference was owing no doubt to the greater abundance of the refuse from
the cookrooms of the naval squadron most frequented by the birds. Persons
acquainted with the economy of the navies of the states in question, will be
able to conjecture which fleet was most favored with these delicate
attentions. The American gull follows the steamers up the Mississippi, and
has been shot 1,500 miles from the sea.] There is a familiar story of an
English bird which built its nest in an unused block in the rigging of a ship,
and made one or two short voyages with the vessel while hatching its eggs.
Had the young become fledged while lying in a foreign harbor, they would
The humming-bird has resisted all efforts to acclimate him in Europe,
though they have not unfrequently survived the passage across the ocean. In
Switzerland and some other parts of Europe the multiplication of
insectivorous birds is encouraged by building nests for them, and it is
alleged that both fruit and forest trees have been essentially benefited by the
protection thus afforded them.] but the distribution of birds is very much
influenced by the character of his industry, and the transplantation, of every
object of agricultural production is, at a longer or shorter interval, followed
by that of the birds which feed upon its seeds, or more frequently upon the
insects it harbors. The vulture, the crow, and other winged scavengers,
follow the march of armies as regularly as the wolf. Birds accompany ships
on long voyages, for the sake of the offal which is thrown overboard, and,
in such cases, it might often happen that they would breed and become
naturalized in countries where they had been unknown before. [Footnote:
Gulls hover about ships in port, and often far out at sea, diligently watching
for the waste of the caboose. While the four great fleets, English, French,
Turkish, and Egyptian, were lying in the Bosphorus, in the summer and
autumn of 1853, a young lady of my family called my attention to the fact
that the gulls were far more numerous about the ships of one of the fleets
than about the others. This was verified by repeated observation, and the
difference was owing no doubt to the greater abundance of the refuse from
the cookrooms of the naval squadron most frequented by the birds. Persons
acquainted with the economy of the navies of the states in question, will be
able to conjecture which fleet was most favored with these delicate
attentions. The American gull follows the steamers up the Mississippi, and
has been shot 1,500 miles from the sea.] There is a familiar story of an
English bird which built its nest in an unused block in the rigging of a ship,
and made one or two short voyages with the vessel while hatching its eggs.
Had the young become fledged while lying in a foreign harbor, they would
Page 167
of course have claimed the rights of citizenship in the country where they
first took to the wing. [Footnote: Birds do not often voluntarily take passage
on board ships bound for foreign countries, but I can testify to one such
case. A stork, which had nested near one of the palaces on the Bosphorus,
had, by some accident, injured a wing, and was unable to join his fellows
when they commenced their winter migration to the banks of the Nile.
Before he was able to fly again, he was caught, and the flag of the nation to
which the palace belonged was tied to his leg, so that he was easily
identified at a considerable distance. As his wing grew stronger, he made
several unsatisfactory experiments at flight, and at last, by a vigorous effort,
succeeded in reaching a passing ship bound southward, and perched himself
on a topsail-yard. I happened to witness this movement, and observed him
quietly maintaining his position as long as I could discern him with a spy-
glass. I supposed he finished the voyage, for he certainly did not return to
the palace.]
An unfortunate popular error greatly magnifies the injury done to the
crops of grain and leguminous vegetables by wild birds. Very many of those
generally supposed to consume large quantities of the seeds of cultivated
plants really feed almost exclusively upon insects, and frequent the
wheatfields, not for the sake of the grain, but for the eggs, larvae, and fly of
the multiplied tribes of insect life which are so destructive to the harvests.
This fact has been so well established by the examination of the stomachs
of great numbers of birds in Europe and the United States, at different
seasons of the year, that it is no longer open to doubt, and it appears highly
probable that even the species which consume more or less grain generally
make amends by destroying insects whose ravages would have been still
more injurious. [Footnote: Even the common crow has found apologists,
and it has been asserted that he pays for the Indian corn he consumes by
destroying the worms and larva which infest that plant.
first took to the wing. [Footnote: Birds do not often voluntarily take passage
on board ships bound for foreign countries, but I can testify to one such
case. A stork, which had nested near one of the palaces on the Bosphorus,
had, by some accident, injured a wing, and was unable to join his fellows
when they commenced their winter migration to the banks of the Nile.
Before he was able to fly again, he was caught, and the flag of the nation to
which the palace belonged was tied to his leg, so that he was easily
identified at a considerable distance. As his wing grew stronger, he made
several unsatisfactory experiments at flight, and at last, by a vigorous effort,
succeeded in reaching a passing ship bound southward, and perched himself
on a topsail-yard. I happened to witness this movement, and observed him
quietly maintaining his position as long as I could discern him with a spy-
glass. I supposed he finished the voyage, for he certainly did not return to
the palace.]
An unfortunate popular error greatly magnifies the injury done to the
crops of grain and leguminous vegetables by wild birds. Very many of those
generally supposed to consume large quantities of the seeds of cultivated
plants really feed almost exclusively upon insects, and frequent the
wheatfields, not for the sake of the grain, but for the eggs, larvae, and fly of
the multiplied tribes of insect life which are so destructive to the harvests.
This fact has been so well established by the examination of the stomachs
of great numbers of birds in Europe and the United States, at different
seasons of the year, that it is no longer open to doubt, and it appears highly
probable that even the species which consume more or less grain generally
make amends by destroying insects whose ravages would have been still
more injurious. [Footnote: Even the common crow has found apologists,
and it has been asserted that he pays for the Indian corn he consumes by
destroying the worms and larva which infest that plant.
Page 168
Professor Treadwell, of Massachusetts, found that a half-grown American
robin in confinement ate in one day sixty-eight worms, weighing together
nearly once and a half as much as the bird himself, and another had
previously starved upon a daily allowance of eight or ten worms, or about
twenty per cent. of his own weight. The largest of these numbers appeared,
so far as could be judged by watching parent birds of the same species, as
they brought food to their young, to be much greater than that supplied to
them when fed in the nest; for the old birds did not return with worms or
insects oftener than once in ten minutes on an average. It we suppose the
parents to hunt for food twelve hours in a day, and a nest to contain four
young, we should have seventy-two worms, or eighteen each, as the daily
supply of the brood. It is probable enough that some of the food collected
by the parents may be more nutritious than the earthworms, and
consequently that a smaller quantity sufficed for the young in the nest than
when reared under artificial conditions.
The supply required by growing birds is not the measure of their wants
after they have arrived at maturity, and it is not by any means certain that
great muscular exertion always increases the demand for nourishment,
either in the lower animals or in man. The members of the English Alpine
Club are not distinguished for appetites which would make them
unwelcome guests to Swiss landlords, and I think every man who has had
the personal charge of field or railway hands, must have observed that
laborers who spare their strength the least are not the most valiant trencher
champions. During the period when imprisonment for debt was permitted in
New England, persons confined in country jails had no specific allowance,
and they were commonly fed without stint. I have often inquired concerning
their diet, and been assured by the jailers that their prisoners, who were not
provided with work or other means of exercise, consumed a considerably
larger supply of food than common out-door laborers.] On this subject, we
have much other evidence besides that derived from dissection. Direct
robin in confinement ate in one day sixty-eight worms, weighing together
nearly once and a half as much as the bird himself, and another had
previously starved upon a daily allowance of eight or ten worms, or about
twenty per cent. of his own weight. The largest of these numbers appeared,
so far as could be judged by watching parent birds of the same species, as
they brought food to their young, to be much greater than that supplied to
them when fed in the nest; for the old birds did not return with worms or
insects oftener than once in ten minutes on an average. It we suppose the
parents to hunt for food twelve hours in a day, and a nest to contain four
young, we should have seventy-two worms, or eighteen each, as the daily
supply of the brood. It is probable enough that some of the food collected
by the parents may be more nutritious than the earthworms, and
consequently that a smaller quantity sufficed for the young in the nest than
when reared under artificial conditions.
The supply required by growing birds is not the measure of their wants
after they have arrived at maturity, and it is not by any means certain that
great muscular exertion always increases the demand for nourishment,
either in the lower animals or in man. The members of the English Alpine
Club are not distinguished for appetites which would make them
unwelcome guests to Swiss landlords, and I think every man who has had
the personal charge of field or railway hands, must have observed that
laborers who spare their strength the least are not the most valiant trencher
champions. During the period when imprisonment for debt was permitted in
New England, persons confined in country jails had no specific allowance,
and they were commonly fed without stint. I have often inquired concerning
their diet, and been assured by the jailers that their prisoners, who were not
provided with work or other means of exercise, consumed a considerably
larger supply of food than common out-door laborers.] On this subject, we
have much other evidence besides that derived from dissection. Direct
Page 169
observation has shown, in many instances, that the destruction of wild birds
has been followed by a great multiplication of noxious insects, and, on the
other hand, that these latter have been much reduced in numbers by the
protection and increase of the birds that devour them. Many interesting
facts of this nature have been collected by professed naturalists, but I shall
content myself with a few taken from familiar and generally accessible
sources. The following extract is from Michelet, L'Oiseau, pp. 169,170:
"The STINGY farmer—an epithet justly and feelingly bestowed by
Virgil. Avaricious, blind, indeed, who proscribes the birds—those
destroyers of insects, those defenders of his harvests. Not a grain for the
creature which, during the rains of winter, hunts the future insect, finds out
the nests of the larvae, examines, turns over every leaf, and destroys, every
day, thousands of incipient caterpillars. But sacks of corn for the mature
insect, whole fields for the grasshoppers, which the bird would have made
war upon. With eyes fixed upon his furrow, upon the present moment only,
without seeing and without foreseeing, blind to the great harmony which is
never broken with impunity, he has everywhere demanded or approved laws
for the extermination of that necessary ally of his toil—the insectivorous
bird. And the insect has well avenged the bird. It has become necessary to
revoke in haste the proscription. In the Isle of Bourbon, for instance, a price
was set on the head of the martin; it disappeared, and the grasshopper took
possession of the island, devouring, withering, scorching with a biting
drought all that they did not consume. In North America it has been the
same with the starling, the protector of Indian corn. [Footnote: I hope
Michelet has good authority for this statement, but I am unable to confirm
it.] Even the sparrow, which really does attack grain, but which protects it
still more, the pilferer, the outlaw, loaded with abuse and smitten with
curses—it has been found in Hungary that they were likely to perish
without him, that he alone could sustain the mighty war against the beetles
and the thousand winged enemies that swarm in the lowlands; they have
has been followed by a great multiplication of noxious insects, and, on the
other hand, that these latter have been much reduced in numbers by the
protection and increase of the birds that devour them. Many interesting
facts of this nature have been collected by professed naturalists, but I shall
content myself with a few taken from familiar and generally accessible
sources. The following extract is from Michelet, L'Oiseau, pp. 169,170:
"The STINGY farmer—an epithet justly and feelingly bestowed by
Virgil. Avaricious, blind, indeed, who proscribes the birds—those
destroyers of insects, those defenders of his harvests. Not a grain for the
creature which, during the rains of winter, hunts the future insect, finds out
the nests of the larvae, examines, turns over every leaf, and destroys, every
day, thousands of incipient caterpillars. But sacks of corn for the mature
insect, whole fields for the grasshoppers, which the bird would have made
war upon. With eyes fixed upon his furrow, upon the present moment only,
without seeing and without foreseeing, blind to the great harmony which is
never broken with impunity, he has everywhere demanded or approved laws
for the extermination of that necessary ally of his toil—the insectivorous
bird. And the insect has well avenged the bird. It has become necessary to
revoke in haste the proscription. In the Isle of Bourbon, for instance, a price
was set on the head of the martin; it disappeared, and the grasshopper took
possession of the island, devouring, withering, scorching with a biting
drought all that they did not consume. In North America it has been the
same with the starling, the protector of Indian corn. [Footnote: I hope
Michelet has good authority for this statement, but I am unable to confirm
it.] Even the sparrow, which really does attack grain, but which protects it
still more, the pilferer, the outlaw, loaded with abuse and smitten with
curses—it has been found in Hungary that they were likely to perish
without him, that he alone could sustain the mighty war against the beetles
and the thousand winged enemies that swarm in the lowlands; they have
Page 170
revoked the decree of banishment, recalled in haste this valiant militia,
which, though deficient in discipline, is nevertheless the salvation of the
country. [Footnote: Apropos of the sparrow—a single pair of which,
according to Michelet, p. 315, carries to the nest four thousand and three
hundred caterpillar or coleoptera in a week—I find in an English newspaper
a report of a meeting of a "Sparrow Club," stating that the member who
took the first prize had destroyed 1,467 of these birds within the year, and
that the prowess of the other members had brought the total number up to
11,944 birds, besides 2,553 eggs. Every one of the fourteen thousand
hatched and unhatched birds, thus sacrificed to puerile vanity and ignorant
prejudice, would have saved his bushel of wheat by preying upon insects
that destroy the grain.]
"Not long since, in the neighborhood of Ronen and in the valley of
Monville, the blackbird was for some time proscribed. The beetles profited
well by this proscription; their larvae, infinitely multiplied, carried on their
subterranean labors with such success, that a meadow was shown me, the
surface of which was completely dried up, every herbaceous root was
consumed, and the whole grassy mantle, easily loosened, might have been
rolled up and carried away like a carpet."
The general hostility of the European populace to the smaller birds is, in
part, the remote effect of the reaction created by the game laws. When the
restrictions imposed upon the chase by those laws were suddenly removed
in France, the whole people at once commenced a destructive campaign
against every species of wild animal. Arthur Young, writing in Provence, on
the 30th of August, 1789, soon after the National Assembly had declared
the chase free, thus complains of the annoyance he experienced from the
use made by the peasantry of their newly-won liberty. "One would think
that every rusty firelock in all Provence was at work in the indiscriminate
destruction of all the birds. The wadding buzzed by my ears, or fell into my
which, though deficient in discipline, is nevertheless the salvation of the
country. [Footnote: Apropos of the sparrow—a single pair of which,
according to Michelet, p. 315, carries to the nest four thousand and three
hundred caterpillar or coleoptera in a week—I find in an English newspaper
a report of a meeting of a "Sparrow Club," stating that the member who
took the first prize had destroyed 1,467 of these birds within the year, and
that the prowess of the other members had brought the total number up to
11,944 birds, besides 2,553 eggs. Every one of the fourteen thousand
hatched and unhatched birds, thus sacrificed to puerile vanity and ignorant
prejudice, would have saved his bushel of wheat by preying upon insects
that destroy the grain.]
"Not long since, in the neighborhood of Ronen and in the valley of
Monville, the blackbird was for some time proscribed. The beetles profited
well by this proscription; their larvae, infinitely multiplied, carried on their
subterranean labors with such success, that a meadow was shown me, the
surface of which was completely dried up, every herbaceous root was
consumed, and the whole grassy mantle, easily loosened, might have been
rolled up and carried away like a carpet."
The general hostility of the European populace to the smaller birds is, in
part, the remote effect of the reaction created by the game laws. When the
restrictions imposed upon the chase by those laws were suddenly removed
in France, the whole people at once commenced a destructive campaign
against every species of wild animal. Arthur Young, writing in Provence, on
the 30th of August, 1789, soon after the National Assembly had declared
the chase free, thus complains of the annoyance he experienced from the
use made by the peasantry of their newly-won liberty. "One would think
that every rusty firelock in all Provence was at work in the indiscriminate
destruction of all the birds. The wadding buzzed by my ears, or fell into my
Page 171
carriage, five or six times in the course of the day." … "The declaration of
the Assembly that every man is free to hunt on his own land … has filled all
France with an intolerable cloud of sportsmen. … The declaration speaks of
compensations and indemnities [to the seigneurs], but the ungovernable
populace takes advantage of the abolition of the game laws and laughs at
the obligation imposed by the decree."
The contagious influence of the French Revolution occasioned the
removal of similar restrictions, with similar results, in other countries. The
habits then formed have become hereditary on the Continent, and though
game laws still exist in England, there is little doubt that the blind
prejudices of the ignorant and half-educated classes in that country against
birds are, in some degree, at least, due to a legislation, which, by restricting
the chase of game worth killing, drives the unprivileged sportsman to
indemnify himself by slaughtering all wild life which is not reserved for the
amusement of his betters. Hence the lord of the manor buys his partridges
and his hares by sacrificing the bread of his tenants, and so long as the
members of "Sparrow Clubs" are forbidden to follow higher game, they will
suicidally revenge themselves by destroying the birds which protect their
wheatfields.
On the Continent, and especially in Italy, the comparative scarcity and
dearness of animal food combine with the feeling I have just mentioned to
stimulate still further the destructive passions of the fowler. In the Tuscan
province of Grosseto, containing less than 2,000 square miles, nearly
300,000 thrushes and other small birds are annually brought to market.
[Footnote: Salvagnoli, Memorie sulle Maremme Toscane, p. 143. The
country about Naples is filled with slender towers fifteen or twenty feet
high, which are a standing puzzle to strangers. They are the stations of the
fowlers who watch from them the flocks of small birds and drive them
down into the nets by throwing stones over them.
the Assembly that every man is free to hunt on his own land … has filled all
France with an intolerable cloud of sportsmen. … The declaration speaks of
compensations and indemnities [to the seigneurs], but the ungovernable
populace takes advantage of the abolition of the game laws and laughs at
the obligation imposed by the decree."
The contagious influence of the French Revolution occasioned the
removal of similar restrictions, with similar results, in other countries. The
habits then formed have become hereditary on the Continent, and though
game laws still exist in England, there is little doubt that the blind
prejudices of the ignorant and half-educated classes in that country against
birds are, in some degree, at least, due to a legislation, which, by restricting
the chase of game worth killing, drives the unprivileged sportsman to
indemnify himself by slaughtering all wild life which is not reserved for the
amusement of his betters. Hence the lord of the manor buys his partridges
and his hares by sacrificing the bread of his tenants, and so long as the
members of "Sparrow Clubs" are forbidden to follow higher game, they will
suicidally revenge themselves by destroying the birds which protect their
wheatfields.
On the Continent, and especially in Italy, the comparative scarcity and
dearness of animal food combine with the feeling I have just mentioned to
stimulate still further the destructive passions of the fowler. In the Tuscan
province of Grosseto, containing less than 2,000 square miles, nearly
300,000 thrushes and other small birds are annually brought to market.
[Footnote: Salvagnoli, Memorie sulle Maremme Toscane, p. 143. The
country about Naples is filled with slender towers fifteen or twenty feet
high, which are a standing puzzle to strangers. They are the stations of the
fowlers who watch from them the flocks of small birds and drive them
down into the nets by throwing stones over them.
Page 172
In Northern and Central Italy, one often sees hillocks crowned with
grove-like plantations of small trees, much resembling large arbors. These
serve to collect birds, which are entrapped in nets in great numbers. These
plantatious are called ragnaje, and the reader will find, in Bindi's edition of
Davanzati, a very pleasant description of a ragnaja, though its authorship is
not now ascribed to that eminent writer. Tschudi has collected in his little
work, Ueber die Landwirthschaftliche Bedeutung der Vogel, many
interesting facts respecting the utility of birds, and, the wanton destruction
of them in Italy and elsewhere. Not only the owl, but many other birds more
familiarly known as predacious in their habits, are useful by destroying
great numbers of mice and moles. The importance of this last service
becomes strikingly apparent when it is known that the burrows of the moles
are among the most frequent causes of rupture in the dikes of the Po, and,
consequently, of inundations which lay many square miles of land under
water. See Annales des Ponts et Chaussees, 1847, 1 semestre, p. 150;
VOGT, Nutzliche und schadliche Thiere; and particularly articles in the
Giornale del Club Alpino, vol. iv., no. 15, and vol. v., no. 16. See also in
Aus der Natur, vol. 54, p. 707, an article entitled Nutzen der Vogel fur die
Landwirthschaft, where it is affirmed that "without birds no agriculture or
even vegetation would be possible." In an interesting memoir by Rondani,
published in the Bolletino del Comizio agrario di Parma for December,
1868, it is maintained that birds are often injurious to the agriculturist, by
preying not only on noxious insects, but sometimes exclusively, or at least
by preference, on entomophagous tribes which would otherwise destroy
those injurious to cultivated plants. See also articles by Prof. Sabbioni in the
Giornale di Agricoltura di Bologna, November and December, 1870, and
other articles in the same journal of 15th and 30th April, 1870.]
Birds are less hardy in constitution, they possess less facility of
accommodation, [Footnote: Wild birds are very tenacious in their habits.
The extension of particular branches of agriculture introduces new birds;
grove-like plantations of small trees, much resembling large arbors. These
serve to collect birds, which are entrapped in nets in great numbers. These
plantatious are called ragnaje, and the reader will find, in Bindi's edition of
Davanzati, a very pleasant description of a ragnaja, though its authorship is
not now ascribed to that eminent writer. Tschudi has collected in his little
work, Ueber die Landwirthschaftliche Bedeutung der Vogel, many
interesting facts respecting the utility of birds, and, the wanton destruction
of them in Italy and elsewhere. Not only the owl, but many other birds more
familiarly known as predacious in their habits, are useful by destroying
great numbers of mice and moles. The importance of this last service
becomes strikingly apparent when it is known that the burrows of the moles
are among the most frequent causes of rupture in the dikes of the Po, and,
consequently, of inundations which lay many square miles of land under
water. See Annales des Ponts et Chaussees, 1847, 1 semestre, p. 150;
VOGT, Nutzliche und schadliche Thiere; and particularly articles in the
Giornale del Club Alpino, vol. iv., no. 15, and vol. v., no. 16. See also in
Aus der Natur, vol. 54, p. 707, an article entitled Nutzen der Vogel fur die
Landwirthschaft, where it is affirmed that "without birds no agriculture or
even vegetation would be possible." In an interesting memoir by Rondani,
published in the Bolletino del Comizio agrario di Parma for December,
1868, it is maintained that birds are often injurious to the agriculturist, by
preying not only on noxious insects, but sometimes exclusively, or at least
by preference, on entomophagous tribes which would otherwise destroy
those injurious to cultivated plants. See also articles by Prof. Sabbioni in the
Giornale di Agricoltura di Bologna, November and December, 1870, and
other articles in the same journal of 15th and 30th April, 1870.]
Birds are less hardy in constitution, they possess less facility of
accommodation, [Footnote: Wild birds are very tenacious in their habits.
The extension of particular branches of agriculture introduces new birds;
Page 173
but unless in the case of such changes in physical conditions, particular
species seem indissolubly attached to particular localities. The migrating
tribes follow almost undeviatingly the same precise line of flight in their
annual journeys, and establish themselves in the same breeding-places from
year to year. The stork is a strong-winged bird and roves far for food, but
very rarely establishes new colonies. He is common in Holland, but
unknown in England. Not above five or six pairs of storks commonly breed
in the suburbs of Constantinople along the European shore of the narrow
Bosphorous, while—much to the satisfaction of the Moslems, who are
justly proud of the marked partiality of so orthodox a bird—dozens of
chimneys of the true believers on the Asiatic side are crowned with his
nests. The appearance of the dove-like grouse, Tetrao paradoxus, or
Syrrhaptus Pallassi, in various parts of Europe, in 1850 and the following
years, is a noticable exception to the law of regularity which seems to
govern the movements and determine the habitat of birds. The proper home
of this bird is the Steppes of Tartary, and it is no recorded to have been
observed in Europe, or at least west of Russia, until the year above
mentioned, when many flocks of twenty or thirty, and even a hundred
individuals, were seen in Bohemia, Germany, Holland, Denmark, England,
Ireland, and France. A considerable flock frequented the Frisian island of
Borkum for more than five months. It was hoped that they would breed and
remain permanently in the island but this expectation has now been
disappointed, and the steppe-grouse seems to have disappeared again
altogether.] and they are more severely affected by climatic excess than
quadrupeds. Besides, they generally want the special means of shelter
against the inclemency of the weather and against pursuit by their enemies,
which holes and dens afford to burrowing animals and to some larger beasts
of prey. The egg is exposed to many dangers before hatching, and the young
bird is especially tender, defenceless, and helpless. Every cold rain, every
violent wind, every hailstorm during the breeding season, destroys hundreds
species seem indissolubly attached to particular localities. The migrating
tribes follow almost undeviatingly the same precise line of flight in their
annual journeys, and establish themselves in the same breeding-places from
year to year. The stork is a strong-winged bird and roves far for food, but
very rarely establishes new colonies. He is common in Holland, but
unknown in England. Not above five or six pairs of storks commonly breed
in the suburbs of Constantinople along the European shore of the narrow
Bosphorous, while—much to the satisfaction of the Moslems, who are
justly proud of the marked partiality of so orthodox a bird—dozens of
chimneys of the true believers on the Asiatic side are crowned with his
nests. The appearance of the dove-like grouse, Tetrao paradoxus, or
Syrrhaptus Pallassi, in various parts of Europe, in 1850 and the following
years, is a noticable exception to the law of regularity which seems to
govern the movements and determine the habitat of birds. The proper home
of this bird is the Steppes of Tartary, and it is no recorded to have been
observed in Europe, or at least west of Russia, until the year above
mentioned, when many flocks of twenty or thirty, and even a hundred
individuals, were seen in Bohemia, Germany, Holland, Denmark, England,
Ireland, and France. A considerable flock frequented the Frisian island of
Borkum for more than five months. It was hoped that they would breed and
remain permanently in the island but this expectation has now been
disappointed, and the steppe-grouse seems to have disappeared again
altogether.] and they are more severely affected by climatic excess than
quadrupeds. Besides, they generally want the special means of shelter
against the inclemency of the weather and against pursuit by their enemies,
which holes and dens afford to burrowing animals and to some larger beasts
of prey. The egg is exposed to many dangers before hatching, and the young
bird is especially tender, defenceless, and helpless. Every cold rain, every
violent wind, every hailstorm during the breeding season, destroys hundreds
Page 174
of nestlings, and the parent often perishes with her progeny while brooding
over it in the vain effort to protect it. [Footnote: It is not the unfledged and
the nursing bird alone that are exposed to destruction by severe weather.
Whole flocks of adult and strong-winged tribes are killed by hail. Severe
winters are usually followed by a sensible diminution in the numbers of the
non-migrating birds, and a cold storm in summer often proves fatal to the
more delicate species. On the 10th of June, 184-, five or six inches of snow
fell in Northern Vermont. The next morning I found a hummingbird killed
by the cold, and hanging by its claws just below a loose clapboard on the
wall of a small wooden building where it had sought shelter.] The great
proportional numbers of birds, their migratory habits, and the ease with
which, by their power of flight they may escape most dangers that beset
them, would seem to secure them from extirpation, and even from very
great numerical reduction. But experience shows that when not protected by
law, by popular favor or superstition, or by other special circumstances,
they yield very readily to the hostile influences of civilization, and, though
the first operations of the settler are favorable to the increase of many
species, the great extension of rural and of mechanical industry is, in a
variety of ways, destructive even to tribes not directly warred upon by man.
[Footnote: Lyell, Antiquity of Man, p. 400, observes: "Of birds it is
estimated that the number of those which die every year equals the
aggregate number by which the species to which they respectively belong
is, on the average, permanently represented." A remarkable instance of the
influence of new circumstances upon birds was observed upon the
establishment of a light-house on Cape Cod some years since. The morning
after the lamps were lighted for the first time, more than a hundred dead
birds of several different species, chiefly water-fowl, were found at the foot
of the tower. They had been killed in the course of the night by flying
against the thick glass or grating of the lantern. From an article by A.
Esquiros, in the Revue des Deux Mondes for Sept. 1, 1864, entitled, La vie
over it in the vain effort to protect it. [Footnote: It is not the unfledged and
the nursing bird alone that are exposed to destruction by severe weather.
Whole flocks of adult and strong-winged tribes are killed by hail. Severe
winters are usually followed by a sensible diminution in the numbers of the
non-migrating birds, and a cold storm in summer often proves fatal to the
more delicate species. On the 10th of June, 184-, five or six inches of snow
fell in Northern Vermont. The next morning I found a hummingbird killed
by the cold, and hanging by its claws just below a loose clapboard on the
wall of a small wooden building where it had sought shelter.] The great
proportional numbers of birds, their migratory habits, and the ease with
which, by their power of flight they may escape most dangers that beset
them, would seem to secure them from extirpation, and even from very
great numerical reduction. But experience shows that when not protected by
law, by popular favor or superstition, or by other special circumstances,
they yield very readily to the hostile influences of civilization, and, though
the first operations of the settler are favorable to the increase of many
species, the great extension of rural and of mechanical industry is, in a
variety of ways, destructive even to tribes not directly warred upon by man.
[Footnote: Lyell, Antiquity of Man, p. 400, observes: "Of birds it is
estimated that the number of those which die every year equals the
aggregate number by which the species to which they respectively belong
is, on the average, permanently represented." A remarkable instance of the
influence of new circumstances upon birds was observed upon the
establishment of a light-house on Cape Cod some years since. The morning
after the lamps were lighted for the first time, more than a hundred dead
birds of several different species, chiefly water-fowl, were found at the foot
of the tower. They had been killed in the course of the night by flying
against the thick glass or grating of the lantern. From an article by A.
Esquiros, in the Revue des Deux Mondes for Sept. 1, 1864, entitled, La vie
Page 175
Anglaise, p. 110, it appears that such occurrences as that stated in the note
have been not unfrequent on the British coast. Are the birds thus attracted
by new lights, flocks in migration?
Migrating birds, whether for greater security from eagles, hawks, and
other enemies, or for some unknown reason, perform a great part of their
annual journeys by night; and it is observed in the Alps that they follow the
high roads in their passage across the mountains. This is partly because the
food in search of which they must sometimes descend is principally found
near the roads. It is, however, not altogether for the sake of consorting with
man, or of profiting by his labors, that their line of flight conforms to the
paths he has traced, but rather because the great roads are carried through
the natural depressions in the chain, and hence the birds can cross the
summit by these routes without rising to a height where at the seasons of
migration the cold would be excessive. The instinct which guides migratory
birds in their course is not in all cases infallible, and it seems to be
confounded by changes in the condition of the surface. I am familiar with a
village in New England, at the junction of two valleys, each drained by a
mill-stream, where the flocks of wild geese which formerly passed, every
spring and autumn, were very frequently lost, as it was popularly phrased,
and I have often heard their screams in the night as they flew wildly about
in perplexity as to the proper course. Perhaps the village lights embarrassed
them, or perhaps the constant changes in the face of the country, from the
clearings then going on, introduced into the landscape features not
according with the ideal map handed down in the anserine family, and thus
deranged its traditional geography.]
Nature sets bounds to the disproportionate increase of birds, while at the
same time, by the multitude of their resources, she secures them from
extinction through her own spontaneous agencies. Man both preys upon
them and wantonly destroys them. The delicious flavor of game-birds, and
have been not unfrequent on the British coast. Are the birds thus attracted
by new lights, flocks in migration?
Migrating birds, whether for greater security from eagles, hawks, and
other enemies, or for some unknown reason, perform a great part of their
annual journeys by night; and it is observed in the Alps that they follow the
high roads in their passage across the mountains. This is partly because the
food in search of which they must sometimes descend is principally found
near the roads. It is, however, not altogether for the sake of consorting with
man, or of profiting by his labors, that their line of flight conforms to the
paths he has traced, but rather because the great roads are carried through
the natural depressions in the chain, and hence the birds can cross the
summit by these routes without rising to a height where at the seasons of
migration the cold would be excessive. The instinct which guides migratory
birds in their course is not in all cases infallible, and it seems to be
confounded by changes in the condition of the surface. I am familiar with a
village in New England, at the junction of two valleys, each drained by a
mill-stream, where the flocks of wild geese which formerly passed, every
spring and autumn, were very frequently lost, as it was popularly phrased,
and I have often heard their screams in the night as they flew wildly about
in perplexity as to the proper course. Perhaps the village lights embarrassed
them, or perhaps the constant changes in the face of the country, from the
clearings then going on, introduced into the landscape features not
according with the ideal map handed down in the anserine family, and thus
deranged its traditional geography.]
Nature sets bounds to the disproportionate increase of birds, while at the
same time, by the multitude of their resources, she secures them from
extinction through her own spontaneous agencies. Man both preys upon
them and wantonly destroys them. The delicious flavor of game-birds, and
Page 176
the skill implied in the various arts of the sportsman who devotes himself to
fowling, make them favorite objects of the chase, while the beauty of their
plumage, as a military and feminine decoration, threatens to involve the
sacrifice of the last survivor of many once numerous species. Thus far, but
few birds described by ancient or modern naturalists are known to have
become absolutely extinct, though there are some cases in which they are
ascertained to have utterly disappeared from the face of the earth in very
recent times. The most familiar instances are those of the dodo, a large bird
peculiar to the Mauritius or Isle of France, exterminated about the year
1690, and now known only by more or less fragmentary skeletons, and the
solitary, which inhabited the islands of Bourbon and Rodriguez, but has not
been seen for more than a century. A parrot and some other birds of the
Norfolk Island group are said to have lately become extinct. The wingless
auk, Alca impennis, a bird remarkable for its excessive fatness, was very
abundant two or three hundred years ago in the Faroe Islands, and on the
whole Scandinavian seaboard. The early voyagers found either the same or
a closely allied species, in immense numbers, on all the coasts and islands
of Newfoundland. The value of its flesh and its oil made it one of the most
important resources of the inhabitants of those sterile regions, and it was
naturally an object of keen pursuit. It is supposed to be now completely
extinct, and few museums can show even its skeleton. There seems to be
strong reason to believe that modern civilization is guiltless of one or two
sins of extermination which have been committed in recent ages. Now
Zealand formerly possessed several species of dinornis, one of which,
called moa by the islanders, was larger than the ostrich. The condition in
which the bones of these birds have been found and the traditions of the
natives concur to prove that, though the aborigines had probably extirpated
them before the discovery of New Zealand by the whites, they still existed
at a comparatively late period. The same remarks apply to a winged giant
the eggs of which have been brought from Madagascar. This bird must have
fowling, make them favorite objects of the chase, while the beauty of their
plumage, as a military and feminine decoration, threatens to involve the
sacrifice of the last survivor of many once numerous species. Thus far, but
few birds described by ancient or modern naturalists are known to have
become absolutely extinct, though there are some cases in which they are
ascertained to have utterly disappeared from the face of the earth in very
recent times. The most familiar instances are those of the dodo, a large bird
peculiar to the Mauritius or Isle of France, exterminated about the year
1690, and now known only by more or less fragmentary skeletons, and the
solitary, which inhabited the islands of Bourbon and Rodriguez, but has not
been seen for more than a century. A parrot and some other birds of the
Norfolk Island group are said to have lately become extinct. The wingless
auk, Alca impennis, a bird remarkable for its excessive fatness, was very
abundant two or three hundred years ago in the Faroe Islands, and on the
whole Scandinavian seaboard. The early voyagers found either the same or
a closely allied species, in immense numbers, on all the coasts and islands
of Newfoundland. The value of its flesh and its oil made it one of the most
important resources of the inhabitants of those sterile regions, and it was
naturally an object of keen pursuit. It is supposed to be now completely
extinct, and few museums can show even its skeleton. There seems to be
strong reason to believe that modern civilization is guiltless of one or two
sins of extermination which have been committed in recent ages. Now
Zealand formerly possessed several species of dinornis, one of which,
called moa by the islanders, was larger than the ostrich. The condition in
which the bones of these birds have been found and the traditions of the
natives concur to prove that, though the aborigines had probably extirpated
them before the discovery of New Zealand by the whites, they still existed
at a comparatively late period. The same remarks apply to a winged giant
the eggs of which have been brought from Madagascar. This bird must have
Page 177
much exceeded the dimensions of the moa, at least so far as we can judge
from the egg, which is eight times as large as the average size of the ostrich
egg, or about one hundred and fifty times that of the hen.
But though we have no evidence that man has exterminated many species
of birds, we know that his persecutions have caused their disappearance
from many localities where they once were common, and greatly
diminished their numbers in others. The cappercailzie, Tetrao urogallus, the
finest of the grouse family, formerly abundant in Scotland, had become
extinct in Great Britain, but has been reintroduced from Sweden. [Footnote:
Thecappercailzie, or tjader, as he is called in Sweden, is a bird of singular
habits, and seems to want some of the protective instincts which secure
most other wild birds from destruction. The younger Laestadius frequently
notices the tjader, in his very remarkable account of the Swedish
Laplanders. The tjader, though not a bird of passage, is migratory, or rather
wandering in domicile, and appears to undertake very purposeless and
absurd journeys. "When he flits," says Laestadius, "he follows a straight
course, and sometimes pursues it quite out of the country. It is said that, in
foggy weather, he sometimes flies out to sea, and, when tired, falls into the
water and is drowned. It is accordingly observed that, when he flies
westwardly, towards the mountains, he soon comes back again; but when he
takes an eastwardly course, he returns no more, and for a long time is very
scarce in Lapland. From this it would seem that he turns back from the bald
mountains, when he discovers that he has strayed from his proper home, the
wood; but when he finds himself over the Baltic, where he cannot alight to
rest and collect himself, he flies on until he is exhausted and falls into the
sea."—Petrus Laestadius, Journal of forsta aret, etc., p. 325.]
The ostrich is mentioned, by many old travellers, as common on the
Isthmus of Suez down to the middle of the seventeenth century. It appears
to have frequented Palestine, Syria, and even Asia Minor at earlier periods,
from the egg, which is eight times as large as the average size of the ostrich
egg, or about one hundred and fifty times that of the hen.
But though we have no evidence that man has exterminated many species
of birds, we know that his persecutions have caused their disappearance
from many localities where they once were common, and greatly
diminished their numbers in others. The cappercailzie, Tetrao urogallus, the
finest of the grouse family, formerly abundant in Scotland, had become
extinct in Great Britain, but has been reintroduced from Sweden. [Footnote:
Thecappercailzie, or tjader, as he is called in Sweden, is a bird of singular
habits, and seems to want some of the protective instincts which secure
most other wild birds from destruction. The younger Laestadius frequently
notices the tjader, in his very remarkable account of the Swedish
Laplanders. The tjader, though not a bird of passage, is migratory, or rather
wandering in domicile, and appears to undertake very purposeless and
absurd journeys. "When he flits," says Laestadius, "he follows a straight
course, and sometimes pursues it quite out of the country. It is said that, in
foggy weather, he sometimes flies out to sea, and, when tired, falls into the
water and is drowned. It is accordingly observed that, when he flies
westwardly, towards the mountains, he soon comes back again; but when he
takes an eastwardly course, he returns no more, and for a long time is very
scarce in Lapland. From this it would seem that he turns back from the bald
mountains, when he discovers that he has strayed from his proper home, the
wood; but when he finds himself over the Baltic, where he cannot alight to
rest and collect himself, he flies on until he is exhausted and falls into the
sea."—Petrus Laestadius, Journal of forsta aret, etc., p. 325.]
The ostrich is mentioned, by many old travellers, as common on the
Isthmus of Suez down to the middle of the seventeenth century. It appears
to have frequented Palestine, Syria, and even Asia Minor at earlier periods,
Page 178
but is now rarely found except in the seclusion of remoter deserts.
[Footnote: Frescobaldi saw ostriches between Suez and Mt. Sinai. Viaggio
in Terra Santa, p. 65. See also Vansler, Voyage d'Egypte, p. 103, and an
article in Petermann, Mittheilungen, 1870, p. 880, entitled Die Verbreitung
des Straussee in Asien.]
The modern increased facilities of transportation have brought distant
markets within reach of the professional hunter, and thereby given a new
impulse to his destructive propensities. Not only do all Great Britain and
Ireland contribute to the supply of game for the British capital, but the
canvas-back duck of the Potomac, and even the prairie hen from the basin
of the Mississippi, may be found at the stalls of the London poulterer. Kohl
[Footnote: Die Herzogthumer Schleswig und Holstein, i., p. 203.] informs
us that, on the coasts of the North Sea, twenty thousand wild ducks are
usually taken in the course of the season in a single decoy, and sent to the
large maritime towns for sale. The statistics of the great European cities
show a prodigious consumption of game-birds, but the official returns fall
far below the truth, because they do not include the rural districts, and
because neither the poacher nor his customers report the number of his
victims. Reproduction, in cultivated countries, cannot keep pace with this
excessive destruction, and there is no doubt that all the wild birds which are
chased for their flesh or their plumage are diminishing with a rapidity
which justifies the fear that the last of them will soon follow the dodo and
the wingless auk.
Fortunately the larger birds which are pursued for their flesh or for their
feathers, and those the eggs of which are used as food, are, so far as we
know the functions appointed to them by nature, not otherwise specially
useful to man, and, therefore, their wholesale destruction is an economical
evil only in the same sense in which all waste of productive capital is an
evil. [Footnote: The increased demand for animal oils for the use of the
[Footnote: Frescobaldi saw ostriches between Suez and Mt. Sinai. Viaggio
in Terra Santa, p. 65. See also Vansler, Voyage d'Egypte, p. 103, and an
article in Petermann, Mittheilungen, 1870, p. 880, entitled Die Verbreitung
des Straussee in Asien.]
The modern increased facilities of transportation have brought distant
markets within reach of the professional hunter, and thereby given a new
impulse to his destructive propensities. Not only do all Great Britain and
Ireland contribute to the supply of game for the British capital, but the
canvas-back duck of the Potomac, and even the prairie hen from the basin
of the Mississippi, may be found at the stalls of the London poulterer. Kohl
[Footnote: Die Herzogthumer Schleswig und Holstein, i., p. 203.] informs
us that, on the coasts of the North Sea, twenty thousand wild ducks are
usually taken in the course of the season in a single decoy, and sent to the
large maritime towns for sale. The statistics of the great European cities
show a prodigious consumption of game-birds, but the official returns fall
far below the truth, because they do not include the rural districts, and
because neither the poacher nor his customers report the number of his
victims. Reproduction, in cultivated countries, cannot keep pace with this
excessive destruction, and there is no doubt that all the wild birds which are
chased for their flesh or their plumage are diminishing with a rapidity
which justifies the fear that the last of them will soon follow the dodo and
the wingless auk.
Fortunately the larger birds which are pursued for their flesh or for their
feathers, and those the eggs of which are used as food, are, so far as we
know the functions appointed to them by nature, not otherwise specially
useful to man, and, therefore, their wholesale destruction is an economical
evil only in the same sense in which all waste of productive capital is an
evil. [Footnote: The increased demand for animal oils for the use of the
Page 179
leather-dresses is now threatening the penguin with the fate of the wingless
auk. According to the Report of the Agricultural Department of the U. S. for
August and September, 1871, p. 840, small vessels are fitted out for the
chase of this bird, and return from a six week's cruise with 25,000 or 30,000
gallons of oil. About eleven birds are required for a gallon, and
consequently the vessels take upon an average 800,000 penguins each.]
If it were possible to confine the consumption of game-fowl to a number
equal to the annual increase, the world would be a gainer, but not to the
same extent as it would be by checking the wanton sacrifice of millions of
the smaller birds, which are of no real value as food, but which, as we have
seen, render a most important service by battling, in our behalf, as well as in
their own, against the countless legions of humming and of creeping things,
with which the prolific powers of insect life would otherwise cover the
earth.
Utility and Destruction of Reptiles.
The disgust and fear with which the serpent is so universally regarded
expose him to constant persecution by man, and perhaps no other animal is
so relentlessly sacrificed by him. Nevertheless, snakes as well as lizards and
other reptiles are not wholly useless to their great enemy. The most
formidable foes of the insect, and even of the small rodents, are the reptiles.
The chameleon approaches the insect perched upon the twig of a tree, with
an almost imperceptible slowness of motion, until, at the distance of a foot,
he shoots out his long, slimy tongue, and rarely fails to secure the victim.
Even the slow toad catches the swift and wary housefly in the same manner;
and in the warm countries of Europe, the numerous lizards contribute very
essentially to the reduction of the insect population, which they both
surprise in the winged state upon walls and trees, and consume as egg,
worm, and chrysalis, in their earlier metamorphoses. The serpents feed
auk. According to the Report of the Agricultural Department of the U. S. for
August and September, 1871, p. 840, small vessels are fitted out for the
chase of this bird, and return from a six week's cruise with 25,000 or 30,000
gallons of oil. About eleven birds are required for a gallon, and
consequently the vessels take upon an average 800,000 penguins each.]
If it were possible to confine the consumption of game-fowl to a number
equal to the annual increase, the world would be a gainer, but not to the
same extent as it would be by checking the wanton sacrifice of millions of
the smaller birds, which are of no real value as food, but which, as we have
seen, render a most important service by battling, in our behalf, as well as in
their own, against the countless legions of humming and of creeping things,
with which the prolific powers of insect life would otherwise cover the
earth.
Utility and Destruction of Reptiles.
The disgust and fear with which the serpent is so universally regarded
expose him to constant persecution by man, and perhaps no other animal is
so relentlessly sacrificed by him. Nevertheless, snakes as well as lizards and
other reptiles are not wholly useless to their great enemy. The most
formidable foes of the insect, and even of the small rodents, are the reptiles.
The chameleon approaches the insect perched upon the twig of a tree, with
an almost imperceptible slowness of motion, until, at the distance of a foot,
he shoots out his long, slimy tongue, and rarely fails to secure the victim.
Even the slow toad catches the swift and wary housefly in the same manner;
and in the warm countries of Europe, the numerous lizards contribute very
essentially to the reduction of the insect population, which they both
surprise in the winged state upon walls and trees, and consume as egg,
worm, and chrysalis, in their earlier metamorphoses. The serpents feed
Page 180
much upon insects, as well as upon mice, moles, and small reptiles,
including also other snakes.
In temperate climates, snakes are consumed by scarcely any beast or bird
of prey except the stork, and they have few dangerous enemies but man,
though in the tropics other animals prey upon them. [Footnote: It is very
questionable whether there is any foundation for the popular belief in the
hostility of swine and of deer to the rattlesnake, and careful experiments as
to the former quadruped seem to show that the supposed enmity is wholly
imaginary. It is however affirmed in an article in Nature, June 11, 1872, p.
215, that the pigs have exterminated the rattlesnake in some parts of
Oregon, and that swine are destructive to the cobra de capello in India.
Observing that the starlings, stornelli, which bred in an old tower in
Piedmont, carried something from their nests and dropped it upon the
ground about as often they brought food to their young, I watched their
proceedings, and found every day lying near the tower numbers of dead or
dying slowworms, and, in a few cases, small lizards, which had, in every
Instance, lost about two inches of the tail. This part I believe the starlings
gave to their nestlings, and threw away the remainder.] It is doubtful
whether any species of serpent has been exterminated within the human
period, and even the dense population of China has not been able
completely to rid itself of the viper. They have, however, almost entirely
disappeared from particular localities. The rattlesnake is now wholly
unknown in many large districts where it was extremely common half a
century ago, and Palestine has long been, if not absolutely free from
venomous serpents, at least very nearly so. [Footnote: Russell denies the
existence of poisonous snakes in Northern Syria, and states that the last
instance of death known to have occurred from the bite of a serpent near
Aleppo took place a hundred years before his time. In Palestine, the climate,
the thinness of population, the multitude of insects and of lizards, all
circumstances, in fact, seem very favorable to the multiplication of serpents,
including also other snakes.
In temperate climates, snakes are consumed by scarcely any beast or bird
of prey except the stork, and they have few dangerous enemies but man,
though in the tropics other animals prey upon them. [Footnote: It is very
questionable whether there is any foundation for the popular belief in the
hostility of swine and of deer to the rattlesnake, and careful experiments as
to the former quadruped seem to show that the supposed enmity is wholly
imaginary. It is however affirmed in an article in Nature, June 11, 1872, p.
215, that the pigs have exterminated the rattlesnake in some parts of
Oregon, and that swine are destructive to the cobra de capello in India.
Observing that the starlings, stornelli, which bred in an old tower in
Piedmont, carried something from their nests and dropped it upon the
ground about as often they brought food to their young, I watched their
proceedings, and found every day lying near the tower numbers of dead or
dying slowworms, and, in a few cases, small lizards, which had, in every
Instance, lost about two inches of the tail. This part I believe the starlings
gave to their nestlings, and threw away the remainder.] It is doubtful
whether any species of serpent has been exterminated within the human
period, and even the dense population of China has not been able
completely to rid itself of the viper. They have, however, almost entirely
disappeared from particular localities. The rattlesnake is now wholly
unknown in many large districts where it was extremely common half a
century ago, and Palestine has long been, if not absolutely free from
venomous serpents, at least very nearly so. [Footnote: Russell denies the
existence of poisonous snakes in Northern Syria, and states that the last
instance of death known to have occurred from the bite of a serpent near
Aleppo took place a hundred years before his time. In Palestine, the climate,
the thinness of population, the multitude of insects and of lizards, all
circumstances, in fact, seem very favorable to the multiplication of serpents,
Page 181
but the venomous species, at least, are extremely rare, if at all known, in
that country. I have, however, been assured by persons very familiar with
Mount Lebanon, that cases of poisoning from the bite of snakes had
occurred within a few years, near Hasbeiyeh, and at other places on the
southern declivities of Lebanon and Hermon. In Egypt, on the other hand,
the cobra, the asp, and the cerastes are as numerous as ever, and are much
dreaded by all the natives except the professional snake charmers.
The recent great multiplication of vipers in some parts of France is a
singular and startling fact. Toussenel, quoting from official documents,
states, that upon the offer of a reward of fifty centimes, or ten cents, a head,
TWELVE THOUSAND vipers were brought to the prefect of a single
department, and that in 1850 fifteen hundred snakes and twenty quarts of
snakes' eggs were found under a farm-house hearthstone. The granary, the
stables, the roof, the very beds swarmed with serpents, and the family were
obliged to abandon its habitation. Dr. Viaugrandmarais, of Nantes, reported
to the prefect of his department more than two hundred recent cases of viper
bites, twenty-four of which proved fatal.—Tristia, p. 176 et seqq. According
to the Journal del Debats for Oct. 1st, 1867, the Department of the Cote
d'Or paid in the year 1866 eighteen thousand francs for the destruction of
vipers. The reward was thirty centimes a head, and consequently the
number killed was about sixty thousand. A friend residing in that
department informs me that it was strongly suspected that many of these
snakes were imported from other departments for the sake of the premium.
In Nature for 1870 and 1871 we are told that the number of deaths from
the bites of venomous serpents in the Bengal Presidency, in the year 1869,
was 11,416, and that in the whole of British India not less than 40,000
human lives are annually lost from this cause. In one small department, a
reward of from three to six pence a head for poisonous serpents brought in
1,200 a day, and in two months the government paid L10,000 sterling for
that country. I have, however, been assured by persons very familiar with
Mount Lebanon, that cases of poisoning from the bite of snakes had
occurred within a few years, near Hasbeiyeh, and at other places on the
southern declivities of Lebanon and Hermon. In Egypt, on the other hand,
the cobra, the asp, and the cerastes are as numerous as ever, and are much
dreaded by all the natives except the professional snake charmers.
The recent great multiplication of vipers in some parts of France is a
singular and startling fact. Toussenel, quoting from official documents,
states, that upon the offer of a reward of fifty centimes, or ten cents, a head,
TWELVE THOUSAND vipers were brought to the prefect of a single
department, and that in 1850 fifteen hundred snakes and twenty quarts of
snakes' eggs were found under a farm-house hearthstone. The granary, the
stables, the roof, the very beds swarmed with serpents, and the family were
obliged to abandon its habitation. Dr. Viaugrandmarais, of Nantes, reported
to the prefect of his department more than two hundred recent cases of viper
bites, twenty-four of which proved fatal.—Tristia, p. 176 et seqq. According
to the Journal del Debats for Oct. 1st, 1867, the Department of the Cote
d'Or paid in the year 1866 eighteen thousand francs for the destruction of
vipers. The reward was thirty centimes a head, and consequently the
number killed was about sixty thousand. A friend residing in that
department informs me that it was strongly suspected that many of these
snakes were imported from other departments for the sake of the premium.
In Nature for 1870 and 1871 we are told that the number of deaths from
the bites of venomous serpents in the Bengal Presidency, in the year 1869,
was 11,416, and that in the whole of British India not less than 40,000
human lives are annually lost from this cause. In one small department, a
reward of from three to six pence a head for poisonous serpents brought in
1,200 a day, and in two months the government paid L10,000 sterling for
Page 182
their destruction.] The serpent does not appear to have any natural limit of
growth, and we are therefore not authorized wholly to discredit the
evidence of ancient naturalists in regard to the extraordinary dimensions
which those reptiles are said by them to have sometimes attained. The use
of firearms has enabled man to reduce the numbers of the larger serpents,
and they do not often escape him long enough to arrive at the size ascribed
to them by travellers a century or two ago. Captain Speke, however, shot a
serpent in Africa which measured fifty-one and a half feet in length.
Some enthusiastic entomologist will, perhaps, by and by discover that
insects and worms are as essential as the larger organisms to the proper
working of the great terraqueous machine, and we shall have as eloquent
pleas in defence of the mosquito, and perhaps oven of the tzetze-fly, as
Toussenel and Michelet have framed in behalf of the bird. The silkworm,
the lac insect, and the bee need no apologist; a gallnut produced by the
puncture of a cynips on a Syrian oak is a necessary ingredient in the ink I
am writing with, and from my windows I recognize the grain of the kermes
and the cochineal in the gay habiliments of the holiday groups beneath
them.
These humble forms of being are seldom conspicuous by more mass, and
though the winds and the waters sometimes sweep together large heaps of
locusts and even of may-flies, their remains are speedily decomposed, their
exuviae and their structures form no strata, and still less does nature use
them, as she does the calcareous and silicious cases and dwellings of
animalcular species, to build reefs and spread out submarine deposits,
which subsequent geological action may convert into islands and even
mountains. [Footnote: Although the remains of extant animals are rarely, if
ever, gathered In sufficient quantities to possess any geographical
importance by their mere mass, the decayed exuviae of even the smaller and
humbler forms of life are sometimes abundant enough to exercise a
growth, and we are therefore not authorized wholly to discredit the
evidence of ancient naturalists in regard to the extraordinary dimensions
which those reptiles are said by them to have sometimes attained. The use
of firearms has enabled man to reduce the numbers of the larger serpents,
and they do not often escape him long enough to arrive at the size ascribed
to them by travellers a century or two ago. Captain Speke, however, shot a
serpent in Africa which measured fifty-one and a half feet in length.
Some enthusiastic entomologist will, perhaps, by and by discover that
insects and worms are as essential as the larger organisms to the proper
working of the great terraqueous machine, and we shall have as eloquent
pleas in defence of the mosquito, and perhaps oven of the tzetze-fly, as
Toussenel and Michelet have framed in behalf of the bird. The silkworm,
the lac insect, and the bee need no apologist; a gallnut produced by the
puncture of a cynips on a Syrian oak is a necessary ingredient in the ink I
am writing with, and from my windows I recognize the grain of the kermes
and the cochineal in the gay habiliments of the holiday groups beneath
them.
These humble forms of being are seldom conspicuous by more mass, and
though the winds and the waters sometimes sweep together large heaps of
locusts and even of may-flies, their remains are speedily decomposed, their
exuviae and their structures form no strata, and still less does nature use
them, as she does the calcareous and silicious cases and dwellings of
animalcular species, to build reefs and spread out submarine deposits,
which subsequent geological action may convert into islands and even
mountains. [Footnote: Although the remains of extant animals are rarely, if
ever, gathered In sufficient quantities to possess any geographical
importance by their mere mass, the decayed exuviae of even the smaller and
humbler forms of life are sometimes abundant enough to exercise a
Page 183
perceptible influence on soil and atmosphere. "The plain of Cumana," saya
Humboldt, "presents a remarkable phenomenon, after heavy rains. The
moistened earth, when heated by the rays of the sun, diffuses the musky
odor common in the torrid zone to animals of very different classes, to the
jaguar, the small species of tiger-cat, the cabiai, the gallinazo vulture, the
crocodile, the viper, and the rattlesnake. The gaseous emanations, the
vehicles of this aroma, appear to be disengaged in proportion as the soil,
which contains the remains of an innumerable multitude of reptiles, worms,
and insects, begins to be impregnated with water. Wherever we stir the
earth, we are struck with the mass of organic substances which in turn are
developed and become transformed or decomposed. Nature in these climes
seems more active, more prolific, and, so to speak, more prodigal of life."]
But the action of the creeping and swarming things of the earth, though
often passed unnoticed, is not without important effects in the general
economy of nature. The geographical importance of insects proper, as well
as of worms, depends principally on their connection with vegetable life as
agents of its fecundation, and of its destruction. We learn from Darwin, "On
Various Contrivances by which British and Foreign Orchids are Fertilized
by Insects," that some six thousand species of orchids are absolutely
dependent upon the agency of insects for their fertilization, and that
consequently, were those plants unvisited by insects, they would all rapidly
disappear. What is true of the orchids is more or less true of many other
vegetable families. [Footnote: Later observations of Darwin and other
naturalists have greatly raised former estimates of the importance of insect
life in the fecundation of plants, and among other remarkable discoveries it
has been found that, in many cases at least, insects are necessary even to
monoecious vegetables, because the male flower does not impregnate the
female growing on the same stem, and the latter can be fecundated only by
pollen supplied to it by insects from another plant of the same species.
Humboldt, "presents a remarkable phenomenon, after heavy rains. The
moistened earth, when heated by the rays of the sun, diffuses the musky
odor common in the torrid zone to animals of very different classes, to the
jaguar, the small species of tiger-cat, the cabiai, the gallinazo vulture, the
crocodile, the viper, and the rattlesnake. The gaseous emanations, the
vehicles of this aroma, appear to be disengaged in proportion as the soil,
which contains the remains of an innumerable multitude of reptiles, worms,
and insects, begins to be impregnated with water. Wherever we stir the
earth, we are struck with the mass of organic substances which in turn are
developed and become transformed or decomposed. Nature in these climes
seems more active, more prolific, and, so to speak, more prodigal of life."]
But the action of the creeping and swarming things of the earth, though
often passed unnoticed, is not without important effects in the general
economy of nature. The geographical importance of insects proper, as well
as of worms, depends principally on their connection with vegetable life as
agents of its fecundation, and of its destruction. We learn from Darwin, "On
Various Contrivances by which British and Foreign Orchids are Fertilized
by Insects," that some six thousand species of orchids are absolutely
dependent upon the agency of insects for their fertilization, and that
consequently, were those plants unvisited by insects, they would all rapidly
disappear. What is true of the orchids is more or less true of many other
vegetable families. [Footnote: Later observations of Darwin and other
naturalists have greatly raised former estimates of the importance of insect
life in the fecundation of plants, and among other remarkable discoveries it
has been found that, in many cases at least, insects are necessary even to
monoecious vegetables, because the male flower does not impregnate the
female growing on the same stem, and the latter can be fecundated only by
pollen supplied to it by insects from another plant of the same species.
Page 184
"Who would ever have thought," says Preyer, "that the abundance and
beauty of the pansy and of the clover were dependent upon the number of
cats and owls But so it is. The clover and the pansy cannot exist without the
bumble-bee, which, in search of his vegetable nectar, transports
unconciously the pollen from the masculine to the feminine flower, a
service which other insects perform only partially for these plants. Their
existence therefore depends upon that of the bumble-bee. The mice make
war upon this bee. In their fondness for honey they destroy the nest and at
the same time the bee. The principal enemies of mice are cats and owls, and
therefore the finest clovers and the most beautiful pansies are found near
villages where cats and owls abound."—Preyer, Der Kampf um daas
Dasein, p. 22. See also Delpino, Pensieri sulla biologia vegetale, and other
works of the same able observer on vegetable physiology.]
We do not know the limits of this agency, and many of the insects
habitually regarded as unqualified pests, may directly or indirectly perform
functions as important to the most valuable plants as the services rendered
by certain tribes to the orchids. I say directly or indirectly, because, besides
the other arrangements of nature for chocking the undue multiplication of
particular species, she has established a police among insects themselves,
by which some of them keep down or promote the increase of others; for
there are insects, as well as birds and beasts, of prey. The existence of an
insect which fertilizes a useful vegetable may depend on that of another
insect which constitutes his food in some stage of his life, and this other
again may be as injurious to some plant as his destroyer is to a different
species.
The ancients, according to Pliny, were accustomed to hang branches of
the wild fig upon the domestic tree, in order that the insects which
frequented the former might hasten the ripening of the cultivated fig by
their punctures—or, as others suppose, might fructify it by transporting to it
beauty of the pansy and of the clover were dependent upon the number of
cats and owls But so it is. The clover and the pansy cannot exist without the
bumble-bee, which, in search of his vegetable nectar, transports
unconciously the pollen from the masculine to the feminine flower, a
service which other insects perform only partially for these plants. Their
existence therefore depends upon that of the bumble-bee. The mice make
war upon this bee. In their fondness for honey they destroy the nest and at
the same time the bee. The principal enemies of mice are cats and owls, and
therefore the finest clovers and the most beautiful pansies are found near
villages where cats and owls abound."—Preyer, Der Kampf um daas
Dasein, p. 22. See also Delpino, Pensieri sulla biologia vegetale, and other
works of the same able observer on vegetable physiology.]
We do not know the limits of this agency, and many of the insects
habitually regarded as unqualified pests, may directly or indirectly perform
functions as important to the most valuable plants as the services rendered
by certain tribes to the orchids. I say directly or indirectly, because, besides
the other arrangements of nature for chocking the undue multiplication of
particular species, she has established a police among insects themselves,
by which some of them keep down or promote the increase of others; for
there are insects, as well as birds and beasts, of prey. The existence of an
insect which fertilizes a useful vegetable may depend on that of another
insect which constitutes his food in some stage of his life, and this other
again may be as injurious to some plant as his destroyer is to a different
species.
The ancients, according to Pliny, were accustomed to hang branches of
the wild fig upon the domestic tree, in order that the insects which
frequented the former might hasten the ripening of the cultivated fig by
their punctures—or, as others suppose, might fructify it by transporting to it
Page 185
the pollen of the wild fruit—and this process, called caprification, is not yet
entirely obsolete. [Footnote: The utility of caprification has been a good
deal disputed, and it has, I believe, been generally abandoned in Italy,
though still practised in Greece. See Browne, The Trees of America, p. 475,
and on caprification in Kabylia, N. Bibesco, Les Kabyles du Djardjura, in
Revue des Deux Mondes for April 1st, 1805, p. 580; also, Aus der Natur,
vol. xxx., p. 684, and Phipson,
Utilization of Minute Life, p. 50. In some parts of Sicily, sprigs of mint,
mentha pulegium, are used instead of branches of the wild for caprification.
Pitre, Usi popolari Siciliani, 1871, p. 18.]
The perforations of the earthworms and of many insect larvae
mechanically affect the texture of the soil and its permeability by water, and
they therefore have a certain influence on the form and character of
terrestrial surface. The earthworms long ago made good their title to the
respect and gratitude of the farmer as well as of the angler. Their utility has
been pointed out in many scientific as well as in many agricultural treatises.
The following extract from an essay on this subject will answer my present
purpose:
"Worms are great assistants to the drainer, and valuable aids to the fanner
in keeping up the fertility of the soil. They love moist, but not wet soils;
they will bore down to, but not into water; they multiply rapidly on land
after drainage, and prefer a deeply-dried soil. On examining part of a field
which had been deeply drained, after long-previous shallow drainage, it was
found that the worms had greatly increased in number, and that their bores
descended quite to the level of the pipes. Many worm-bores were large
enough to receive the little finger. A piece of land near the sea, in
Lincolnshire, over which the sea had broken and killed all the worms,
remained sterile until the worms again inhabited it. A piece of pasture land,
entirely obsolete. [Footnote: The utility of caprification has been a good
deal disputed, and it has, I believe, been generally abandoned in Italy,
though still practised in Greece. See Browne, The Trees of America, p. 475,
and on caprification in Kabylia, N. Bibesco, Les Kabyles du Djardjura, in
Revue des Deux Mondes for April 1st, 1805, p. 580; also, Aus der Natur,
vol. xxx., p. 684, and Phipson,
Utilization of Minute Life, p. 50. In some parts of Sicily, sprigs of mint,
mentha pulegium, are used instead of branches of the wild for caprification.
Pitre, Usi popolari Siciliani, 1871, p. 18.]
The perforations of the earthworms and of many insect larvae
mechanically affect the texture of the soil and its permeability by water, and
they therefore have a certain influence on the form and character of
terrestrial surface. The earthworms long ago made good their title to the
respect and gratitude of the farmer as well as of the angler. Their utility has
been pointed out in many scientific as well as in many agricultural treatises.
The following extract from an essay on this subject will answer my present
purpose:
"Worms are great assistants to the drainer, and valuable aids to the fanner
in keeping up the fertility of the soil. They love moist, but not wet soils;
they will bore down to, but not into water; they multiply rapidly on land
after drainage, and prefer a deeply-dried soil. On examining part of a field
which had been deeply drained, after long-previous shallow drainage, it was
found that the worms had greatly increased in number, and that their bores
descended quite to the level of the pipes. Many worm-bores were large
enough to receive the little finger. A piece of land near the sea, in
Lincolnshire, over which the sea had broken and killed all the worms,
remained sterile until the worms again inhabited it. A piece of pasture land,
Page 186
in which worms were in such numbers that it was thought their casts
interfered too much with its produce, was rolled at night in order to destroy
the worms. The result was, that the fertility of the field greatly declined, nor
was it restored until they had recruited their numbers, which was aided by
collecting and transporting multitudes of worms from the fields.
"The great depth into which worms will bore, and from which they push
up fine fertile soil, and cast it on the surface, have been well shown by the
fact that in a few years they have actually elevated the surface of fields by a
largo layer of rich mould, several inches thick, thus affording nourishment
to the roots of grasses, and increasing the productiveness of the soil."
It should be added that the writer quoted, and all others who have
discussed the subject, have, so far as I know, overlooked one very important
element in the fertilization produced by earthworms. I refer to the
enrichment of the soil by their excreta during life, and by the decomposition
of their remains when they die. Themanure thus furnished is as valuable as
the like amount of similar animal products derived from higher organisms,
and when we consider the prodigious numbers of these worms found on a
single square yard of some soils, we may easily see that they furnish no
insignificant contribution to the nutritive material required for the growth of
plants. [Footnote: I believe there is no foundation for the supposition that
earthworms attack the tuber of the potato. Some of them, especially one or
two species employed by anglers as bait, if natives of the woods, are at least
rare in shaded grounds, but multiply very rapidly after the soil is brought
under cultivation. Forty or fifty years ago they were so scarce in the newer
parts of New England, that the rustic fishermen of every village kept secret
the few places where they were to be found in their neighborhood, as a
professional mystery, but at present one can hardly turn over a shovelfull of
rich moist soil anywhere, without unearthing several of them. A very
intelligent lady, born in the woods of Northern New England, told me that,
interfered too much with its produce, was rolled at night in order to destroy
the worms. The result was, that the fertility of the field greatly declined, nor
was it restored until they had recruited their numbers, which was aided by
collecting and transporting multitudes of worms from the fields.
"The great depth into which worms will bore, and from which they push
up fine fertile soil, and cast it on the surface, have been well shown by the
fact that in a few years they have actually elevated the surface of fields by a
largo layer of rich mould, several inches thick, thus affording nourishment
to the roots of grasses, and increasing the productiveness of the soil."
It should be added that the writer quoted, and all others who have
discussed the subject, have, so far as I know, overlooked one very important
element in the fertilization produced by earthworms. I refer to the
enrichment of the soil by their excreta during life, and by the decomposition
of their remains when they die. Themanure thus furnished is as valuable as
the like amount of similar animal products derived from higher organisms,
and when we consider the prodigious numbers of these worms found on a
single square yard of some soils, we may easily see that they furnish no
insignificant contribution to the nutritive material required for the growth of
plants. [Footnote: I believe there is no foundation for the supposition that
earthworms attack the tuber of the potato. Some of them, especially one or
two species employed by anglers as bait, if natives of the woods, are at least
rare in shaded grounds, but multiply very rapidly after the soil is brought
under cultivation. Forty or fifty years ago they were so scarce in the newer
parts of New England, that the rustic fishermen of every village kept secret
the few places where they were to be found in their neighborhood, as a
professional mystery, but at present one can hardly turn over a shovelfull of
rich moist soil anywhere, without unearthing several of them. A very
intelligent lady, born in the woods of Northern New England, told me that,
Page 187
in her childhood, these worms were almost unknown in that region, though
anxiously sought for by the anglers, but that they increased as the country
was cleared, and at last became so numerous in some places, that the water
of springs, and even of shallow wells, which had formerly been excellent,
was rendered undrinkable by the quantity of dead worms that fell into them.
The increase of the robin and other small birds which follow the settler
when he has prepared a suitable home for them, at last checked the
excessive multiplication of the worms, and abated the nuisance.]
The carnivorous and often herbivorous insects render another important
service to man by consuming dead and decaying animal and vegetable
matter, the decomposition of which would otherwise fill the air with
effluvia noxious to health. Some of them, the grave-digger beetle, for
instance, bury the small animals in which they lay their eggs, and thereby
prevent the escape of the gases disengaged by putrefaction. The prodigious
rapidity of development in insect life, the great numbers of the individuals
in many species, and the voracity of most of them while in the larva state,
justify the appellation of nature's scavengers which has been bestowed upon
them, and there is very little doubt that, in warm countries, they consume a
larger quantity of putrescent organic matter than the quadrupeds and birds
which feed upon such aliment.
INJURY TO THE FOREST BY INSECTS.
The action of the insect on vegetation, as we have thus far described it, is
principally exerted on smaller and less conspicuous plants, and it is
therefore matter rather of agricultural than of geographical interest. But in
the economy of the forest European writers ascribe to insect life an
importance which it has not reached in America, where the spontaneous
woods are protected by safeguards of nature's own devising.
anxiously sought for by the anglers, but that they increased as the country
was cleared, and at last became so numerous in some places, that the water
of springs, and even of shallow wells, which had formerly been excellent,
was rendered undrinkable by the quantity of dead worms that fell into them.
The increase of the robin and other small birds which follow the settler
when he has prepared a suitable home for them, at last checked the
excessive multiplication of the worms, and abated the nuisance.]
The carnivorous and often herbivorous insects render another important
service to man by consuming dead and decaying animal and vegetable
matter, the decomposition of which would otherwise fill the air with
effluvia noxious to health. Some of them, the grave-digger beetle, for
instance, bury the small animals in which they lay their eggs, and thereby
prevent the escape of the gases disengaged by putrefaction. The prodigious
rapidity of development in insect life, the great numbers of the individuals
in many species, and the voracity of most of them while in the larva state,
justify the appellation of nature's scavengers which has been bestowed upon
them, and there is very little doubt that, in warm countries, they consume a
larger quantity of putrescent organic matter than the quadrupeds and birds
which feed upon such aliment.
INJURY TO THE FOREST BY INSECTS.
The action of the insect on vegetation, as we have thus far described it, is
principally exerted on smaller and less conspicuous plants, and it is
therefore matter rather of agricultural than of geographical interest. But in
the economy of the forest European writers ascribe to insect life an
importance which it has not reached in America, where the spontaneous
woods are protected by safeguards of nature's own devising.
Page 188
The insects which damage primitive forests by feeding upon products of
trees essential to their growth, are not numerous, nor is their appearance, in
destructive numbers, frequent, and those which perforate the stems and
branches, to deposit and hatch their eggs, more commonly select dead trees
for that purpose, though, unhappily, there are important exceptions to this
latter remark. [Footnote: The locust Insect, Clitus pictus, which deposits its
eggs in the American locust, Robinia pseudacacia, is one of these, and its
ravages have been and still are more destructive to that very valuable tree,
so remarkable for combining rapidity of growth with strength and durability
of wood. This insect, I believe, has not yet appeared in Europe, where, since
the so general employment of the Robinia to clothe and protect
embankments and the scarps of deep cuts on railroads, it would do
incalculable mischief. As a traveller, however, I should find some
compensation for this evil in the destruction of these acacia hedges, which
as completely obstruct the view on hundreds of miles of French and Italian
railways, as do the garden walls of the same countries on the ordinary
roads.
The lignivorous insects that attack living trees almost uniformly confine
their ravages to trees already unsound or diseased in growth from the
depredations of leaf-eaters, such as caterpillars and the like, or from other
causes. The decay of the tree, therefore, is the cause not the consequence of
the invasions of the borer. This subject has been discussed by Perris in the
Annales de la Societe Entomologique de la France for 1852, and his
conclusions are confirmed by the observations of Samanos, who quotes, at
some length, the views of Perris. "Having, for fifteen years," says the latter
author, "incessantly studied the habits of lignivorous insects in one of the
best wooded regions of France, I have observed facts enough to feel myself
warranted in expressing my conclusions, which are: that insects in general
—I am trees in sound health, and they assail those only whose normal
conditions and functions have been by some cause impaired."
trees essential to their growth, are not numerous, nor is their appearance, in
destructive numbers, frequent, and those which perforate the stems and
branches, to deposit and hatch their eggs, more commonly select dead trees
for that purpose, though, unhappily, there are important exceptions to this
latter remark. [Footnote: The locust Insect, Clitus pictus, which deposits its
eggs in the American locust, Robinia pseudacacia, is one of these, and its
ravages have been and still are more destructive to that very valuable tree,
so remarkable for combining rapidity of growth with strength and durability
of wood. This insect, I believe, has not yet appeared in Europe, where, since
the so general employment of the Robinia to clothe and protect
embankments and the scarps of deep cuts on railroads, it would do
incalculable mischief. As a traveller, however, I should find some
compensation for this evil in the destruction of these acacia hedges, which
as completely obstruct the view on hundreds of miles of French and Italian
railways, as do the garden walls of the same countries on the ordinary
roads.
The lignivorous insects that attack living trees almost uniformly confine
their ravages to trees already unsound or diseased in growth from the
depredations of leaf-eaters, such as caterpillars and the like, or from other
causes. The decay of the tree, therefore, is the cause not the consequence of
the invasions of the borer. This subject has been discussed by Perris in the
Annales de la Societe Entomologique de la France for 1852, and his
conclusions are confirmed by the observations of Samanos, who quotes, at
some length, the views of Perris. "Having, for fifteen years," says the latter
author, "incessantly studied the habits of lignivorous insects in one of the
best wooded regions of France, I have observed facts enough to feel myself
warranted in expressing my conclusions, which are: that insects in general
—I am trees in sound health, and they assail those only whose normal
conditions and functions have been by some cause impaired."
Page 189
See, more fully, Samanos, Traite de la Culture du Pin Maritime, Paris,
1864, pp. 140-145, and Siemoni, Manuale dell' Arte Forestale. 2d edition.
Florence, 1872.]
I do not know that we have any evidence of the destruction or serious
injury of American forests by insects before or even soon after the period of
colonization; but since the white man has laid bare a vast proportion of the
earth's surface, and thereby produced changes favorable, perhaps, to the
multiplication of these pests, they have greatly increased in numbers, and,
apparently, in voracity also. Not many years ago, the pines on thousands of
acres of land in North Carolina were destroyed by insects not known to
have ever done serious injury to that tree before. In such cases as this and
others of the like sort, there is good reason to believe that man is the
indirect cause of an evil for which he pays so heavy a penalty. Insects
increase whenever the birds which feed upon them disappear. Hence, in the
wanton destruction of the robin and other insectivorous birds, the bipes
implumis, the featherless biped, man, is not only exchanging the vocal
orchestra which greets the rising sun for the drowny beetle's evening drone,
and depriving his groves and his fields of their fairest ornament, but he is
waging a treacherous warfare on his natural allies. [Footnote: In the
artificial woods of Europe, insects are far more numerous and destructive to
trees than in the primitive forests of America, and the same remark may be
made of the smaller rodents, such as moles, mice, and squirrels. In the
dense native wood, the ground and the air are too humid, the depth of shade
too great, for many tribes of these creatures, while near the natural
meadows and other open grounds, where circumstances are otherwise more
favorable for their existence and multiplication, their numbers are kept
down by birds, serpents, foxes, and smaller predacious quadrupeds. In
civilized countries these natural enemies of the worm, the beetle, and the
mole, are persecuted, sometimes almost exterminated, by man, who also
removes from his plantations the decayed or wind-fallen trcea, the shrubs
1864, pp. 140-145, and Siemoni, Manuale dell' Arte Forestale. 2d edition.
Florence, 1872.]
I do not know that we have any evidence of the destruction or serious
injury of American forests by insects before or even soon after the period of
colonization; but since the white man has laid bare a vast proportion of the
earth's surface, and thereby produced changes favorable, perhaps, to the
multiplication of these pests, they have greatly increased in numbers, and,
apparently, in voracity also. Not many years ago, the pines on thousands of
acres of land in North Carolina were destroyed by insects not known to
have ever done serious injury to that tree before. In such cases as this and
others of the like sort, there is good reason to believe that man is the
indirect cause of an evil for which he pays so heavy a penalty. Insects
increase whenever the birds which feed upon them disappear. Hence, in the
wanton destruction of the robin and other insectivorous birds, the bipes
implumis, the featherless biped, man, is not only exchanging the vocal
orchestra which greets the rising sun for the drowny beetle's evening drone,
and depriving his groves and his fields of their fairest ornament, but he is
waging a treacherous warfare on his natural allies. [Footnote: In the
artificial woods of Europe, insects are far more numerous and destructive to
trees than in the primitive forests of America, and the same remark may be
made of the smaller rodents, such as moles, mice, and squirrels. In the
dense native wood, the ground and the air are too humid, the depth of shade
too great, for many tribes of these creatures, while near the natural
meadows and other open grounds, where circumstances are otherwise more
favorable for their existence and multiplication, their numbers are kept
down by birds, serpents, foxes, and smaller predacious quadrupeds. In
civilized countries these natural enemies of the worm, the beetle, and the
mole, are persecuted, sometimes almost exterminated, by man, who also
removes from his plantations the decayed or wind-fallen trcea, the shrubs
Page 190
and underwood, which, in a state of nature, furnished food and shelter to the
borer and the rodent, and often also to the animals that preyed upon them.
Hence the insect and the gnawing quadruped are allowed to increase, from
the expulsion of the police which, in the natural wood, prevent their
excessive multiplication, and they become destructive to the forest because
they are driven to the living tree for nutriment and cover. The forest of
Fontainebleau is almost wholly without birds, and their absence is ascribed
by some writers to the want of water, which, in the thirsty sands of that
wood, does not gather into running brooks; but the want of undergrowth is
perhaps an equally good reason for their scarcity.
On the other hand, the thinning out of the forest and the removal of
underwood and decayed timber, by which it is brought more nearly to the
condition of an artificial wood, is often destructive to insect tribes which,
though not injurious to trees, are noxious to man. Thus the troublesome
woodtick, formerly very abundant in the North Eastern, as it unhappily still
is in native forests in the Southern and Western States, has become nearly or
quite extinct in the former region since the woods have been reduced in
extent and laid more open to the sun and air.—Asa Fitch, in Report of New
York Agricultural Society for 1870, pp. 868,864.]
Introduction of Insects.
The general tendency of man's encroachments upon spontaneous nature
has been to increase insect life at the expense of vegetation and of the
smaller quadrupeds and birds. Doubtless there are insects in all woods, but
in temperate climates they are comparatively few and harmless, and the
most numerous tribes which breed in the forest, or rather in its waters, and
indeed in all solitudes, are those which little injure vegetation, such as
mosquitoes, gnats, and the like. With the cultivated plants of man come the
myriad tribes which feed or breed upon them, and agriculture not only
borer and the rodent, and often also to the animals that preyed upon them.
Hence the insect and the gnawing quadruped are allowed to increase, from
the expulsion of the police which, in the natural wood, prevent their
excessive multiplication, and they become destructive to the forest because
they are driven to the living tree for nutriment and cover. The forest of
Fontainebleau is almost wholly without birds, and their absence is ascribed
by some writers to the want of water, which, in the thirsty sands of that
wood, does not gather into running brooks; but the want of undergrowth is
perhaps an equally good reason for their scarcity.
On the other hand, the thinning out of the forest and the removal of
underwood and decayed timber, by which it is brought more nearly to the
condition of an artificial wood, is often destructive to insect tribes which,
though not injurious to trees, are noxious to man. Thus the troublesome
woodtick, formerly very abundant in the North Eastern, as it unhappily still
is in native forests in the Southern and Western States, has become nearly or
quite extinct in the former region since the woods have been reduced in
extent and laid more open to the sun and air.—Asa Fitch, in Report of New
York Agricultural Society for 1870, pp. 868,864.]
Introduction of Insects.
The general tendency of man's encroachments upon spontaneous nature
has been to increase insect life at the expense of vegetation and of the
smaller quadrupeds and birds. Doubtless there are insects in all woods, but
in temperate climates they are comparatively few and harmless, and the
most numerous tribes which breed in the forest, or rather in its waters, and
indeed in all solitudes, are those which little injure vegetation, such as
mosquitoes, gnats, and the like. With the cultivated plants of man come the
myriad tribes which feed or breed upon them, and agriculture not only
Page 191
introduces new speciss, but so multiplies the number of individuals as to
defy calculation. Newly introduced vegetables frequently escape for years
the insect plagues which had infested them in their native habitat; but the
importation of other varieties of the plant, the exchange of seed, or some
more accident, is sure in the long run to carry the egg, the larva, or the
chrysalis to the most distant shores where the plant assigned to it by nature
as its possession has preceded it. For many years after the colonization of
the United States, few or none of the insects which attack wheat in its
different stages of growth, were known in America. During the
Revolutionary war, the Hessian fly, Cecidomyia destructrix, made its
appearance, and it was so called because it was first observed in the year
when the Hessian troops were brought over, and was popularly supposed to
have been accidentally imported by those unwelcome strangers. Other
destroyers of cereal grains have since found their way across the Atlantic,
and a noxious European aphis has first attacked the American wheatfields
within the last fifteen years. Unhappily, in these cases of migration, the
natural corrective of excessive multiplication, the parasitic or voracious
enemy of the noxious insect, does not always accompany the wanderings of
its prey, and the bane long precedes the antidote. Hence, in the United
States, the ravages of imported insects injurious to cultivated crops, not
being checked by the counteracting influences which nature had provided to
limit their devastations in the Old World, are more destructive than in
Europe. It is not known that the wheat midge is preyed upon in America by
any other insect, and in seasons favorable to it, it multiplies to a degree
which would prove almost fatal to the entire harvest, were it not that, in the
great territorial extent of the United States, there is room for such
differences of soil and climate as, in a given year, to present in one State all
the conditions favorable to the increase of a particular insect, while in
another, the natural influences are hostile to it. The only apparent remedy
for this evil is, to balance the disproportionate development of noxious
defy calculation. Newly introduced vegetables frequently escape for years
the insect plagues which had infested them in their native habitat; but the
importation of other varieties of the plant, the exchange of seed, or some
more accident, is sure in the long run to carry the egg, the larva, or the
chrysalis to the most distant shores where the plant assigned to it by nature
as its possession has preceded it. For many years after the colonization of
the United States, few or none of the insects which attack wheat in its
different stages of growth, were known in America. During the
Revolutionary war, the Hessian fly, Cecidomyia destructrix, made its
appearance, and it was so called because it was first observed in the year
when the Hessian troops were brought over, and was popularly supposed to
have been accidentally imported by those unwelcome strangers. Other
destroyers of cereal grains have since found their way across the Atlantic,
and a noxious European aphis has first attacked the American wheatfields
within the last fifteen years. Unhappily, in these cases of migration, the
natural corrective of excessive multiplication, the parasitic or voracious
enemy of the noxious insect, does not always accompany the wanderings of
its prey, and the bane long precedes the antidote. Hence, in the United
States, the ravages of imported insects injurious to cultivated crops, not
being checked by the counteracting influences which nature had provided to
limit their devastations in the Old World, are more destructive than in
Europe. It is not known that the wheat midge is preyed upon in America by
any other insect, and in seasons favorable to it, it multiplies to a degree
which would prove almost fatal to the entire harvest, were it not that, in the
great territorial extent of the United States, there is room for such
differences of soil and climate as, in a given year, to present in one State all
the conditions favorable to the increase of a particular insect, while in
another, the natural influences are hostile to it. The only apparent remedy
for this evil is, to balance the disproportionate development of noxious
Page 192
foreign species by bringing from their native country the tribes which prey
upon them. This, it seems, has been attempted. The United States Census
Report for 1860, p. 82, states that the New York Agricultural Society "has
introduced into this country from abroad certain parasites which Providence
has created to counteract the destructive powers of some of these
depredators." [Footnote: On parasitic and entomophagous insects, see a
paper by Rondani referred to p. 119 ante.]
This is, however, not the only purpose for which man has designedly
introduced foreign forms of insect life. The eggs of the silkworm are known
to have been brought from the farther East to Europe in the sixth century,
and new silk-spinners which feed on the castor-oil bean and the ailanthus,
have recently been reared in France and in South America with promising
success. [Footnote: The silkworm which feeds on the ailanthus has
naturalized itself in the United States, but also the promises of its utility
have not been realized.] The cochineal, long regularly bred in aboriginal
America, has been transplanted to Spain, and both the kermes insect and the
cantharides have been transferred to other climates than their own. The
honey—bee must be ranked next to the silkworm in economical
importance. This useful creature was carried to the United States by
European colonists, in the latter part of theseventeenth century; it did not
cross the Mississippi till the close of the eighteenth, and it is only in 1853
that it was transported to California, where it was previously unknown. The
Italian bee, which seldom stings, has lately been introduced into the United
States. [Footnote: Bee husbandry, now very general in Switzerland and
other Alpine regions, was formerly an important branch of industry in Italy.
It has lately been revived and is now extensively prosecuted it that country.
It is interesting to observe that many of the methods recently introduced
into this art in England and United States, such for example as the
removable honey—boxes, are reinventions of Italian systeams at least three
hundred years old. See Gallo, Le Venti Giornate dell' Agricultura, cap. XV.
upon them. This, it seems, has been attempted. The United States Census
Report for 1860, p. 82, states that the New York Agricultural Society "has
introduced into this country from abroad certain parasites which Providence
has created to counteract the destructive powers of some of these
depredators." [Footnote: On parasitic and entomophagous insects, see a
paper by Rondani referred to p. 119 ante.]
This is, however, not the only purpose for which man has designedly
introduced foreign forms of insect life. The eggs of the silkworm are known
to have been brought from the farther East to Europe in the sixth century,
and new silk-spinners which feed on the castor-oil bean and the ailanthus,
have recently been reared in France and in South America with promising
success. [Footnote: The silkworm which feeds on the ailanthus has
naturalized itself in the United States, but also the promises of its utility
have not been realized.] The cochineal, long regularly bred in aboriginal
America, has been transplanted to Spain, and both the kermes insect and the
cantharides have been transferred to other climates than their own. The
honey—bee must be ranked next to the silkworm in economical
importance. This useful creature was carried to the United States by
European colonists, in the latter part of theseventeenth century; it did not
cross the Mississippi till the close of the eighteenth, and it is only in 1853
that it was transported to California, where it was previously unknown. The
Italian bee, which seldom stings, has lately been introduced into the United
States. [Footnote: Bee husbandry, now very general in Switzerland and
other Alpine regions, was formerly an important branch of industry in Italy.
It has lately been revived and is now extensively prosecuted it that country.
It is interesting to observe that many of the methods recently introduced
into this art in England and United States, such for example as the
removable honey—boxes, are reinventions of Italian systeams at least three
hundred years old. See Gallo, Le Venti Giornate dell' Agricultura, cap. XV.
Page 193
The temporary decline of this industry in Italy was doubtless in great
measure due to the use of sugar which had taken the place of honed, but
perhaps also in part to the decrease of the wild vegetation from which the
bee draws more or less of his nutriment. A new was-producing insect, a
species of coccus, very abundant in China, where its annual produce is said
to amount to the value of ten millions of francs, has recently attracted notice
in France. The wax is white, resembling spermaceti, and is said to be
superior to that of the bee.]
The insects and worms intentionally transplanted by man bear but a small
portion to those accidentally introduced by him. Plants and animals often
carry their parasites with them, and the traffic of commercial countries,
which exchange their products with every zone and every stage of social
existence, cannot fail to transfer in both directions the minute organisms
that are, in one way or another associated with almost every object
important to the material interests of man. [Footnote: A few years ago, a
laborer, employed at a North American port in discharging a cargo of hides
from the opposite extremity of the continent, was fatally poisoned by the
bite or the sting of an unknown insect, which ran out from a hide he was
handling.
The Phylloxera vastatrix, the most destructive pest which has ever
attacked European vineyards—for its ravages are fatal not merely to the
fruit, but to the vine itself—in said by many entomologists to be of
American origin, but I have seen no account of the mode of its
introduction.]
The tenacity of life possessed by many insects, their prodigious
fecundity, the length of time they often remain in the different phases of
their existence, [Footnote: In many insects, some of the stages of life
regularly continue for several years, and they may, under peculiar
measure due to the use of sugar which had taken the place of honed, but
perhaps also in part to the decrease of the wild vegetation from which the
bee draws more or less of his nutriment. A new was-producing insect, a
species of coccus, very abundant in China, where its annual produce is said
to amount to the value of ten millions of francs, has recently attracted notice
in France. The wax is white, resembling spermaceti, and is said to be
superior to that of the bee.]
The insects and worms intentionally transplanted by man bear but a small
portion to those accidentally introduced by him. Plants and animals often
carry their parasites with them, and the traffic of commercial countries,
which exchange their products with every zone and every stage of social
existence, cannot fail to transfer in both directions the minute organisms
that are, in one way or another associated with almost every object
important to the material interests of man. [Footnote: A few years ago, a
laborer, employed at a North American port in discharging a cargo of hides
from the opposite extremity of the continent, was fatally poisoned by the
bite or the sting of an unknown insect, which ran out from a hide he was
handling.
The Phylloxera vastatrix, the most destructive pest which has ever
attacked European vineyards—for its ravages are fatal not merely to the
fruit, but to the vine itself—in said by many entomologists to be of
American origin, but I have seen no account of the mode of its
introduction.]
The tenacity of life possessed by many insects, their prodigious
fecundity, the length of time they often remain in the different phases of
their existence, [Footnote: In many insects, some of the stages of life
regularly continue for several years, and they may, under peculiar
Page 194
circumstances, be almost indefinitely prolonged. Dr. Dwight mentions the
following remarkable case of this sort: "I saw here an insect, about an inch
in length, of a brown color tinged with orange, with two antennae, not
unlike a rosebug. This insect came out of a tea-table made of the boards of
an apple-tree." Dr. Dwight found the "cavity whence the insect had emerged
into the light," to be "about two inches in length. Between the hole, and the
outside of the leaf of the table, there were forty grains of the wood." It was
supposed that the sawyer and the cabinet-maker must have removed at least
thirteen grains more, and the table had been in the possession of its
proprietor for twenty years.] the security of the retreats into which their
small dimensions enable them to retire, are all circumstances very favorable
not only to the perpetuity of their species, but to their transportation to
distant climates and their multiplication in their new homes. The teredo, so
destructive to shipping, has been carried by the vessels whose wooden walls
it mines to almost every part of the globe. The termite, or white ant, is said
to have been brought to Rochefort by the commerce of that port a hundred
years ago. [Footnote: It does not appear to be quite settled whether the
termites of France are indigenous or imported. See Quatrefaces, Souvenirs
d'un naturaliste, ii., pp. 400, 542, 543.
The white ant has lately appeared at St. Helena and is in a high degree
destructive, no wood but teak, and even that not always, resisting it.—
Nature for March 2d, 1871, p. 362.] This creature is more injurious to
wooden structures and implements than any other known insect. It eats out
almost the entire substance of the wood, leaving only thin partitions
between the galleries it excavates in it; but as it never gnaws through the
surface to the air, a stick of timber may be almost wholly consumed without
showing any external sign of the damage it has sustained. The termite is
found also in other parts of France, and particularly at Rochelle, where, thus
far, its ravages are confined to a single quarter of the city. A borer, of similar
habits, is not uncommon in Italy, and you may see in that country handsome
following remarkable case of this sort: "I saw here an insect, about an inch
in length, of a brown color tinged with orange, with two antennae, not
unlike a rosebug. This insect came out of a tea-table made of the boards of
an apple-tree." Dr. Dwight found the "cavity whence the insect had emerged
into the light," to be "about two inches in length. Between the hole, and the
outside of the leaf of the table, there were forty grains of the wood." It was
supposed that the sawyer and the cabinet-maker must have removed at least
thirteen grains more, and the table had been in the possession of its
proprietor for twenty years.] the security of the retreats into which their
small dimensions enable them to retire, are all circumstances very favorable
not only to the perpetuity of their species, but to their transportation to
distant climates and their multiplication in their new homes. The teredo, so
destructive to shipping, has been carried by the vessels whose wooden walls
it mines to almost every part of the globe. The termite, or white ant, is said
to have been brought to Rochefort by the commerce of that port a hundred
years ago. [Footnote: It does not appear to be quite settled whether the
termites of France are indigenous or imported. See Quatrefaces, Souvenirs
d'un naturaliste, ii., pp. 400, 542, 543.
The white ant has lately appeared at St. Helena and is in a high degree
destructive, no wood but teak, and even that not always, resisting it.—
Nature for March 2d, 1871, p. 362.] This creature is more injurious to
wooden structures and implements than any other known insect. It eats out
almost the entire substance of the wood, leaving only thin partitions
between the galleries it excavates in it; but as it never gnaws through the
surface to the air, a stick of timber may be almost wholly consumed without
showing any external sign of the damage it has sustained. The termite is
found also in other parts of France, and particularly at Rochelle, where, thus
far, its ravages are confined to a single quarter of the city. A borer, of similar
habits, is not uncommon in Italy, and you may see in that country handsome
Page 195
chairs and other furniture which have been reduced by this insect to a
framework of powder of post, covered, and apparently held together, by
nothing but the varnish.
DESTRUCTION OF INSECTS.
It is well known to naturalists, but less familiarly to common observers, that
the aquatic larvae of some insects which in other stages of their existence
inhabit the land, constitute, at certain seasons, a large part of the food of
fresh-water fish, while other larvae, in their turn, prey upon the spawn and
even the young of their persecutors. [Footnote: I have seen the larva of the
dragon-fly in an aquarium bite off the head of a young fish as long as itself.]
The larvae of the mosquito and the gnat are the favorite food of the trout in
the wooded regions where those insects abound. [Footnote: Insects and fish
—which prey upon and feed each other—are the only forms of animal life
that are numerous in the native woods, and their range is, of course, limited
by the extent of the waters. The great abundance of the trout, and of other
more or less allied genera in the lakes of Lapland, seems to be due to the
supply of food provided for them by the swarms of insects which in the
larva state inhabit the waters, or, in other stages of their life, are
accidentally swept into them. All travellers in the north of Europe speak of
the gnat and the mosquito as very serious drawbacks upon the enjoyments
of the summer tourist, who visits the head of the Gulf of Bothnia to see the
midnight sun, and the brothers Laestadius regard them as one of the great
plagues of sub-arctic life. "The persecutions of these insects," says Lars
Levi Laestadius [Culex pipiens, Culex reptans, and Culex pulicaris], "leave
not a moment's peace, by day or night, to any living creature. Not only man,
but cattle, and even birds and wild beasts, suffer intolerably from their bite."
He adds in a note, "I will not affirm that they have ever devoured a living
man, but many young cattle, such as lambs and calves, have been worried
framework of powder of post, covered, and apparently held together, by
nothing but the varnish.
DESTRUCTION OF INSECTS.
It is well known to naturalists, but less familiarly to common observers, that
the aquatic larvae of some insects which in other stages of their existence
inhabit the land, constitute, at certain seasons, a large part of the food of
fresh-water fish, while other larvae, in their turn, prey upon the spawn and
even the young of their persecutors. [Footnote: I have seen the larva of the
dragon-fly in an aquarium bite off the head of a young fish as long as itself.]
The larvae of the mosquito and the gnat are the favorite food of the trout in
the wooded regions where those insects abound. [Footnote: Insects and fish
—which prey upon and feed each other—are the only forms of animal life
that are numerous in the native woods, and their range is, of course, limited
by the extent of the waters. The great abundance of the trout, and of other
more or less allied genera in the lakes of Lapland, seems to be due to the
supply of food provided for them by the swarms of insects which in the
larva state inhabit the waters, or, in other stages of their life, are
accidentally swept into them. All travellers in the north of Europe speak of
the gnat and the mosquito as very serious drawbacks upon the enjoyments
of the summer tourist, who visits the head of the Gulf of Bothnia to see the
midnight sun, and the brothers Laestadius regard them as one of the great
plagues of sub-arctic life. "The persecutions of these insects," says Lars
Levi Laestadius [Culex pipiens, Culex reptans, and Culex pulicaris], "leave
not a moment's peace, by day or night, to any living creature. Not only man,
but cattle, and even birds and wild beasts, suffer intolerably from their bite."
He adds in a note, "I will not affirm that they have ever devoured a living
man, but many young cattle, such as lambs and calves, have been worried
Page 196
out of their lives by them. All the people of Lapland declare that young
birds are killed by them, and this is not improbable, for birds are scarce
after seasons when the midge, the gnlat, and the mosquito are numerous."—
Om Uppodlingar i Lappmarken, p. 50.
Petrus Laestadius makes similar statements in his Journal for forsta urst,
p. 283.]
Earlier in the year the trout feeds on the larvae of the May fly, which is
itself very destructive to the spawn of the salmon, and hence, by a sort of
house-that-Jack-built, the destruction of the mosquito, that feeds the trout
that preys on the May fly that destroys the eggs that hatch the salmon that
pampers the epicure, may occasion a scarcity of this latter fish in waters
where he would otherwise be abundant. Thus all nature is linked together
by invisible bonds, and every organic creature, however low, however
feeble, however dependent, is necessary to the well-being of some other
among the myriad forms of life with which the Creator has peopled the
earth.
I have said that man has promoted the increase of the insect and the
worm, by destroying the bird and the fish which feed upon them. Many
insects, in the four different stages of their growth, inhabit in succession the
earth, the water, and the air. In each of these elements they have their
special enemies, and, deep and dark as are the minute recesses in which
they hide themselves, they are pursued to the remotest, obscurest corners by
the executioners that nature has appointed to punish their delinquencies, and
furnished with cunning contrivances for ferreting out the offenders and
dragging them into the light of day. One tribe of birds, the woodpeckers,
seems to depend for subsistence almost wholly on those insects which breed
in dead or dying trees, and it is, perhaps, needless to say that the injury
these birds do the forest is imaginary. They do not cut holes in the trunk of
birds are killed by them, and this is not improbable, for birds are scarce
after seasons when the midge, the gnlat, and the mosquito are numerous."—
Om Uppodlingar i Lappmarken, p. 50.
Petrus Laestadius makes similar statements in his Journal for forsta urst,
p. 283.]
Earlier in the year the trout feeds on the larvae of the May fly, which is
itself very destructive to the spawn of the salmon, and hence, by a sort of
house-that-Jack-built, the destruction of the mosquito, that feeds the trout
that preys on the May fly that destroys the eggs that hatch the salmon that
pampers the epicure, may occasion a scarcity of this latter fish in waters
where he would otherwise be abundant. Thus all nature is linked together
by invisible bonds, and every organic creature, however low, however
feeble, however dependent, is necessary to the well-being of some other
among the myriad forms of life with which the Creator has peopled the
earth.
I have said that man has promoted the increase of the insect and the
worm, by destroying the bird and the fish which feed upon them. Many
insects, in the four different stages of their growth, inhabit in succession the
earth, the water, and the air. In each of these elements they have their
special enemies, and, deep and dark as are the minute recesses in which
they hide themselves, they are pursued to the remotest, obscurest corners by
the executioners that nature has appointed to punish their delinquencies, and
furnished with cunning contrivances for ferreting out the offenders and
dragging them into the light of day. One tribe of birds, the woodpeckers,
seems to depend for subsistence almost wholly on those insects which breed
in dead or dying trees, and it is, perhaps, needless to say that the injury
these birds do the forest is imaginary. They do not cut holes in the trunk of
Page 197
the tree to prepare a lodgment for a future colony of boring larvae, but to
extract the worm which has already begun his mining labors. Hence these
birds are not found where the forester removes trees as fast as they become
fit habitations for such insects. In clearing new lands in the United States,
dead trees, especially of the spike-leaved kinds, too much decayed to serve
for timber, and which, in that state, are worth little for fuel, are often
allowed to stand until they fall of themselves. Such stubs, as they are
popularly called, are filled with borers, and often deeply cut by the
woodpeckers, whose strong bills enable them to penetrate to the very heart
of the tree and drag out the lurking larvae. After a few years, the stubs fall,
or, as wood becomes valuable, are cut and carried off for firewood, and, at
the same time, the farmer selects for felling, in the forest he has reserved as
a permanent source of supply of fuel and timber, the decaying trees which,
like the dead stems in the fields, serve as a home for both the worm and his
pursuer. We thus gradually extirpate this tribe of insects, and, with them, the
species of birds which subsist principally upon them. Thus the fine, large,
red-headed woodpecker, Picus erythrocephalus, formerly very common in
New England, has almost entirely disappeared from those States, since the
dead trees are gone, and the apples, his favorite vegetable food, are less
abundant.
There are even large quadrupeds which feed almost exclusively upon
insects. The ant-bear is strong enough to pull down the clay houses built by
the species of termites that constitute his ordinary diet, and the curious ai-ai,
a climbing quadruped of Madagascar, is provided with a very slender, hook-
nailed finger, long enough to reach far into a hole in the trunk of a tree, and
extract the worm which bored it. [Footnote: On the destruction of insects by
reptiles, see page 125 ante.]
Minute Organisms.
extract the worm which has already begun his mining labors. Hence these
birds are not found where the forester removes trees as fast as they become
fit habitations for such insects. In clearing new lands in the United States,
dead trees, especially of the spike-leaved kinds, too much decayed to serve
for timber, and which, in that state, are worth little for fuel, are often
allowed to stand until they fall of themselves. Such stubs, as they are
popularly called, are filled with borers, and often deeply cut by the
woodpeckers, whose strong bills enable them to penetrate to the very heart
of the tree and drag out the lurking larvae. After a few years, the stubs fall,
or, as wood becomes valuable, are cut and carried off for firewood, and, at
the same time, the farmer selects for felling, in the forest he has reserved as
a permanent source of supply of fuel and timber, the decaying trees which,
like the dead stems in the fields, serve as a home for both the worm and his
pursuer. We thus gradually extirpate this tribe of insects, and, with them, the
species of birds which subsist principally upon them. Thus the fine, large,
red-headed woodpecker, Picus erythrocephalus, formerly very common in
New England, has almost entirely disappeared from those States, since the
dead trees are gone, and the apples, his favorite vegetable food, are less
abundant.
There are even large quadrupeds which feed almost exclusively upon
insects. The ant-bear is strong enough to pull down the clay houses built by
the species of termites that constitute his ordinary diet, and the curious ai-ai,
a climbing quadruped of Madagascar, is provided with a very slender, hook-
nailed finger, long enough to reach far into a hole in the trunk of a tree, and
extract the worm which bored it. [Footnote: On the destruction of insects by
reptiles, see page 125 ante.]
Minute Organisms.
Page 198
Besides the larger inhabitants of the land and of the sea, the quadrupeds,
the reptiles, the birds, the amphibia, the crustacea, the fish, the insects, and
the worms, there are other countless forms of vital being. Earth, water, the
ducts and fluids of vegetable and of animal life, the very air we breathe, are
peopled by minute organisms which perform most important functionsin
both the living and the inanimate kingdoms of nature. Of the offices
assigned to these creatures, the most familiar to common observation is the
extraction of lime, and, more rarely, of silex, from the waters inhabited by
them, and the deposit of these minerals in a solid form, either as the
material of their habitations or as the exuviae of their bodies. The
microscope and other means of scientific observation assure us that the
chalk-beds of England and of France, the coral reefs of marine waters in
warm climates, vast calcareous and silicious deposits in the sea and in many
fresh-water ponds, the common polishing earths and slates, and many
species of apparently dense and solid rock, are the work of the humble
organisms of which I speak, often, indeed, of animaculae so small as to
become visible only by the aid of lenses magnifying thousands of times the
linear measures. It is popularly supposed that animalculae, or what are
commonly embraced under the vague name of infusoria, inhabit the water
alone, but naturalists have long known that the atmospheric dust transported
by every wind and deposited by every calm is full of microscopic life or of
its relics. The soil on which the city of Berlin stands, contains, at the depth
of ten or fifteen feet below the surface, living elaborators of silex;
[Footnote: Wittwer, Physikalische Geographie, p. 142.] and a microscopic
examination of a handful of earth connected with the material evidences of
guilt has enabled the naturalist to point out the very spot where a crime was
committed. It has been computed that one-sixth part of the solid matter let
fall by great rivers at their outlets consists of still recognizable infusory
shells and shields, and, as the friction of rolling water must reduce many of
these fragile structures to a state of comminution which even the
the reptiles, the birds, the amphibia, the crustacea, the fish, the insects, and
the worms, there are other countless forms of vital being. Earth, water, the
ducts and fluids of vegetable and of animal life, the very air we breathe, are
peopled by minute organisms which perform most important functionsin
both the living and the inanimate kingdoms of nature. Of the offices
assigned to these creatures, the most familiar to common observation is the
extraction of lime, and, more rarely, of silex, from the waters inhabited by
them, and the deposit of these minerals in a solid form, either as the
material of their habitations or as the exuviae of their bodies. The
microscope and other means of scientific observation assure us that the
chalk-beds of England and of France, the coral reefs of marine waters in
warm climates, vast calcareous and silicious deposits in the sea and in many
fresh-water ponds, the common polishing earths and slates, and many
species of apparently dense and solid rock, are the work of the humble
organisms of which I speak, often, indeed, of animaculae so small as to
become visible only by the aid of lenses magnifying thousands of times the
linear measures. It is popularly supposed that animalculae, or what are
commonly embraced under the vague name of infusoria, inhabit the water
alone, but naturalists have long known that the atmospheric dust transported
by every wind and deposited by every calm is full of microscopic life or of
its relics. The soil on which the city of Berlin stands, contains, at the depth
of ten or fifteen feet below the surface, living elaborators of silex;
[Footnote: Wittwer, Physikalische Geographie, p. 142.] and a microscopic
examination of a handful of earth connected with the material evidences of
guilt has enabled the naturalist to point out the very spot where a crime was
committed. It has been computed that one-sixth part of the solid matter let
fall by great rivers at their outlets consists of still recognizable infusory
shells and shields, and, as the friction of rolling water must reduce many of
these fragile structures to a state of comminution which even the
Page 199
microscope cannot resolve into distinct particles and identify as relics of
animal or of vegetable life, we must conclude that a considerably larger
proportion of river deposits is really the product of animalcules. [Footnote:
To vary the phrase, I make occasional use of animaloule, which, as a
popular designation, embraces all microscopic organisms. The name is
founded on the now exploded supposition that all of them are animated,
which was the general belief of naturalists when attention was first drawn to
them. It was soon discovered that many of them were unquestionably
vegetable, and there are numerous genera the true classification of which is
a matter of dispute among the ablest observers. There are cases in which
objects formerly taken for living animalcules turn out to be products of the
decomposition of matter once animated, and it is admitted that neither
spontaneous motion nor even apparent irritability are sure signs of animal
life.]
It is evident that the chemical, and in many cases mechanical, character
of a great number of the objects important in the material economy of
human life, must be affected by the presence of so large an organic element
in their substance, and it is equally obvious that all agricultural and all
industrial operations tend to disturb the natural arrangements of this
element, to increase or to diminish the special adaptation of every medium
in which it lives to the particular orders of being inhabited by it. The
conversion of woodland into pasturage, of pasture into plough land, of
swamp or of shallow sea into dry ground, the rotations of cultivated crops,
must prove fatal to millions of living things upon every rood of surface thus
deranged by man, and must, at the same time, more or less fully
compensate this destruction of life by promoting the growth and
multiplication of other tribes equally minute in dimensions. I do not know
that man has yet endeavored to avail himself, by artificial contrivances, of
the agency of these wonderful architects and manufacturers. We are hardly
well enough acquainted with their natural economy to devise means to turn
animal or of vegetable life, we must conclude that a considerably larger
proportion of river deposits is really the product of animalcules. [Footnote:
To vary the phrase, I make occasional use of animaloule, which, as a
popular designation, embraces all microscopic organisms. The name is
founded on the now exploded supposition that all of them are animated,
which was the general belief of naturalists when attention was first drawn to
them. It was soon discovered that many of them were unquestionably
vegetable, and there are numerous genera the true classification of which is
a matter of dispute among the ablest observers. There are cases in which
objects formerly taken for living animalcules turn out to be products of the
decomposition of matter once animated, and it is admitted that neither
spontaneous motion nor even apparent irritability are sure signs of animal
life.]
It is evident that the chemical, and in many cases mechanical, character
of a great number of the objects important in the material economy of
human life, must be affected by the presence of so large an organic element
in their substance, and it is equally obvious that all agricultural and all
industrial operations tend to disturb the natural arrangements of this
element, to increase or to diminish the special adaptation of every medium
in which it lives to the particular orders of being inhabited by it. The
conversion of woodland into pasturage, of pasture into plough land, of
swamp or of shallow sea into dry ground, the rotations of cultivated crops,
must prove fatal to millions of living things upon every rood of surface thus
deranged by man, and must, at the same time, more or less fully
compensate this destruction of life by promoting the growth and
multiplication of other tribes equally minute in dimensions. I do not know
that man has yet endeavored to avail himself, by artificial contrivances, of
the agency of these wonderful architects and manufacturers. We are hardly
well enough acquainted with their natural economy to devise means to turn
Page 200
their industry to profitable account, and they are in very many cases too
slow in producing visible results for an age so impatient as ours. The over-
civilization of the nineteenth century cannot wait for wealth to be amassed
by infinitesimal gains, and we are in haste to SPECULATE upon the powers
of nature, as we do upon objects of bargain and sale in our trafficking one
with another. But there are still some cases where the little we know of a
life, whose workings are invisible to the naked eye, suggests the possibility
of advantageously directing the efforts of troops of artisans that we cannot
see. Upon coasts occupied by the corallines, the reef-building animalcule
does not work near the mouth of rivers. Hence the change of the outlet of a
stream, often a very busy matter, may promote the construction of a barrier
to coast navigation at one point, and check the formation of a reef at
another, by diverting a current of fresh water from the former and pouring it
into the sea at the latter. Cases may probably be found, in tropical seas,
where rivers have prevented the working of the coral animalcules in straits
separating islands from each other or from the mainland. The diversion of
such streams might remove this obstacle, and reefs consequently be formed
which should convert an archipelago into a single large island, and finally
join that to the neighboring continent. Quatrefages proposed to destroy the
teredo in harbors by impregnating the water with a mineral solution fatal to
them. Perhaps the labors of the coralline animals might be arrested over a
considerable extent of sea-coast by similar means. The reef-builders are
leisurely architects, but the precious coral is formed so rapidly that the beds
may be refished advantageously as often as once in ten years. [Footnote:
The smallest twig of the precious coral thrown back into the sea attaches
itself to the bottom or a rock, and grows as well as on its native stem. See
an interesting report on the coral fishery, by Sant' Agabio, Italian Consul-
General at Algiers, in the Bollettino Consolare, published by the
Department of Foreign Affairs, 1862, pp. 139, 151, and in the Annali di
Agricoltura Industria e Commercio, No. ii., pp. 300, 373.]
slow in producing visible results for an age so impatient as ours. The over-
civilization of the nineteenth century cannot wait for wealth to be amassed
by infinitesimal gains, and we are in haste to SPECULATE upon the powers
of nature, as we do upon objects of bargain and sale in our trafficking one
with another. But there are still some cases where the little we know of a
life, whose workings are invisible to the naked eye, suggests the possibility
of advantageously directing the efforts of troops of artisans that we cannot
see. Upon coasts occupied by the corallines, the reef-building animalcule
does not work near the mouth of rivers. Hence the change of the outlet of a
stream, often a very busy matter, may promote the construction of a barrier
to coast navigation at one point, and check the formation of a reef at
another, by diverting a current of fresh water from the former and pouring it
into the sea at the latter. Cases may probably be found, in tropical seas,
where rivers have prevented the working of the coral animalcules in straits
separating islands from each other or from the mainland. The diversion of
such streams might remove this obstacle, and reefs consequently be formed
which should convert an archipelago into a single large island, and finally
join that to the neighboring continent. Quatrefages proposed to destroy the
teredo in harbors by impregnating the water with a mineral solution fatal to
them. Perhaps the labors of the coralline animals might be arrested over a
considerable extent of sea-coast by similar means. The reef-builders are
leisurely architects, but the precious coral is formed so rapidly that the beds
may be refished advantageously as often as once in ten years. [Footnote:
The smallest twig of the precious coral thrown back into the sea attaches
itself to the bottom or a rock, and grows as well as on its native stem. See
an interesting report on the coral fishery, by Sant' Agabio, Italian Consul-
General at Algiers, in the Bollettino Consolare, published by the
Department of Foreign Affairs, 1862, pp. 139, 151, and in the Annali di
Agricoltura Industria e Commercio, No. ii., pp. 300, 373.]
Page 201
It does not seem impossible that branches of this coral might be attached
to the keel of a ship and transplanted to the American coast, where the Gulf
stream would furnish a suitable temperature beyond the climatic limits that
otherwise confine its growth; and thus a new source of profit might perhaps
be added to the scanty returns of the hardy fisherman. In certain geological
formations, the diatomaceae deposit, at the bottom of fresh-water ponds,
beds of silicious shields, valuable as a material for a species of very light
firebrick, in the manufacture of water-glass and of hydraulic cement, and
ultimately, doubtless, in many yet undiscovered industrial processes. An
attentive study of the conditions favorable to the propagation of the
diatomaceae might perhaps help us to profit directly by the productivity of
this organism, and, at the same time, disclose secrets of nature capable of
being turned to valuable account in dealing with silicious rocks, and the
metal which is the base of them.
Our acquaintance with the obscure and infinitesimal life of which I have
now been treating is very recent, and still very imperfect. We know that it is
of vast importance in geology, but we are so ambitious to grasp the great, so
little accustomed to occupy ourselves with the minute, that we are not yet
prepared to enter seriously upon the question how far we can control and
utilize the operations, not of unembodied physical forces merely, but of
beings, in popular apprehension, almost as immaterial as they.
Disturbance of Natural Balances.
It is highly probable that the reef-builders and other yet unstudied minute
forms of vital existence have other functions in the economy of nature
besides aiding in the architecture of the globe, and stand in important
relations not only to man but to the plants and the larger sentient creatures
over which he has dominion. The diminution or multiplication of these
unseen friends or foes may be attended with the gravest consequences to all
to the keel of a ship and transplanted to the American coast, where the Gulf
stream would furnish a suitable temperature beyond the climatic limits that
otherwise confine its growth; and thus a new source of profit might perhaps
be added to the scanty returns of the hardy fisherman. In certain geological
formations, the diatomaceae deposit, at the bottom of fresh-water ponds,
beds of silicious shields, valuable as a material for a species of very light
firebrick, in the manufacture of water-glass and of hydraulic cement, and
ultimately, doubtless, in many yet undiscovered industrial processes. An
attentive study of the conditions favorable to the propagation of the
diatomaceae might perhaps help us to profit directly by the productivity of
this organism, and, at the same time, disclose secrets of nature capable of
being turned to valuable account in dealing with silicious rocks, and the
metal which is the base of them.
Our acquaintance with the obscure and infinitesimal life of which I have
now been treating is very recent, and still very imperfect. We know that it is
of vast importance in geology, but we are so ambitious to grasp the great, so
little accustomed to occupy ourselves with the minute, that we are not yet
prepared to enter seriously upon the question how far we can control and
utilize the operations, not of unembodied physical forces merely, but of
beings, in popular apprehension, almost as immaterial as they.
Disturbance of Natural Balances.
It is highly probable that the reef-builders and other yet unstudied minute
forms of vital existence have other functions in the economy of nature
besides aiding in the architecture of the globe, and stand in important
relations not only to man but to the plants and the larger sentient creatures
over which he has dominion. The diminution or multiplication of these
unseen friends or foes may be attended with the gravest consequences to all
Page 202
his material interests, and he is dealing with dangerous weapons whenever
he interferes with arrangements pre-established by a power higher than his
own. The equation of animal and vegetable life is too complicated a
problem for human intelligence to solve, and we can never know how wide
a circle of disturbance we produce in the harmonics of nature when we
throw the smallest pebble into the ocean of organic being. This much,
however, the facts I have hitherto presented authorize us to conclude: as
often as we destroy the balance by deranging the original proportions
between different orders of spontaneous life, the law of self-preservation
requires us to restore the equilibrium, by either directly returning the weight
abstracted from one scale, or removing a corresponding quantity from the
other. In other words, destruction must be either repaired by reproduction,
or compensated by new destruction in an opposite quarter. The parlor
aquarium has taught even those to whom it is but an amusing toy, that the
balance of animal and vegetable life must be preserved, and that the excess
of either is fatal to the other, in the artificial tank as well as in natural
waters. A few years ago, the water of the Cochituato aqueduct at Boston
became so offensive in smell and taste as to be quite unfit for use. Scientific
investigation found the cause in the too scrupulous care with which aquatic
vegetation had been excluded from the reservoir, and the consequent death
and decay of the animalculae, which could not be shut out, nor live in the
water without the vegetable element. [Footnote: It is remarkable that
Pulisay, to whose great merits as an acute observer I am happy to have
frequent occasion to bear testimony, had noticed that vegetation was
necessary to maintain the purity of water in artificial reservoirs, though he
mistook the rationale of its influence, which he ascribed to the elemental
"salt" supposed by him to play an important part in all the operations of
nature. In his treatise upon Waters and Fountains, p. 174, of the reprint of
1844, he says: "And in special, thou shalt note one point, the which is
understood of few: that is to say, that the leaves of the trees which fall upon
he interferes with arrangements pre-established by a power higher than his
own. The equation of animal and vegetable life is too complicated a
problem for human intelligence to solve, and we can never know how wide
a circle of disturbance we produce in the harmonics of nature when we
throw the smallest pebble into the ocean of organic being. This much,
however, the facts I have hitherto presented authorize us to conclude: as
often as we destroy the balance by deranging the original proportions
between different orders of spontaneous life, the law of self-preservation
requires us to restore the equilibrium, by either directly returning the weight
abstracted from one scale, or removing a corresponding quantity from the
other. In other words, destruction must be either repaired by reproduction,
or compensated by new destruction in an opposite quarter. The parlor
aquarium has taught even those to whom it is but an amusing toy, that the
balance of animal and vegetable life must be preserved, and that the excess
of either is fatal to the other, in the artificial tank as well as in natural
waters. A few years ago, the water of the Cochituato aqueduct at Boston
became so offensive in smell and taste as to be quite unfit for use. Scientific
investigation found the cause in the too scrupulous care with which aquatic
vegetation had been excluded from the reservoir, and the consequent death
and decay of the animalculae, which could not be shut out, nor live in the
water without the vegetable element. [Footnote: It is remarkable that
Pulisay, to whose great merits as an acute observer I am happy to have
frequent occasion to bear testimony, had noticed that vegetation was
necessary to maintain the purity of water in artificial reservoirs, though he
mistook the rationale of its influence, which he ascribed to the elemental
"salt" supposed by him to play an important part in all the operations of
nature. In his treatise upon Waters and Fountains, p. 174, of the reprint of
1844, he says: "And in special, thou shalt note one point, the which is
understood of few: that is to say, that the leaves of the trees which fall upon
Page 203
the parterre, and the herbs growing beneath, and singularly the fruits, if any
there be upon the trees, being decayed, the waters of the parterre shall draw
onto them the salt of the said fruits, leaves, and herbs, the which shall
greatly better the water of thy fountains, and hinder the putrefaction
thereof."]
Animalcular Life.
Nature has no unit of magnitude by which she measures her works. Man
takes his standards of dimension from himself. The hair's breadth was his
minimum until the microscope told him that there are animated creatures to
which one of the hairs of his head is a larger cylinder than is the trunk of the
giant California sequoia to him. He borrows his inch from the breadth of his
thumb, his palm and span from the width of his hand and the spread of his
fingers, his foot from the length of the organ so named; his cubit is the
distance from the tip of his middle finger to his elbow, and his fathom is the
space he can measure with his outstretched arms. [Footnote: The French
metrical system seems destined to be adopted throughout the civilized
world. It is indeed recommended by great advantages, but it is very
doubtful whether they are not more than counterbalanced by the selection of
too large a unit of measure, and by the inherent intractability of all decimal
systems with reference to fractional divisions. The experience of the whole
world has established the superior convenience of a smaller unit, such as the
braccio, the cubit, the foot, and the palm or span, and in practical life every
man finds that he haa much more frequent occasion to use a fraction than a
multiple of the metre. Of course, he must constantly employ numbers
expressive of several centimetres or millimetres instend of the name of a
single smaller unit than the metre. Besides, the metre is not divisible into
twelfths, eighths, sixths, or thirds, or the multiples of any of these
proportions, two of which at least—the eighth and the third—are of as
there be upon the trees, being decayed, the waters of the parterre shall draw
onto them the salt of the said fruits, leaves, and herbs, the which shall
greatly better the water of thy fountains, and hinder the putrefaction
thereof."]
Animalcular Life.
Nature has no unit of magnitude by which she measures her works. Man
takes his standards of dimension from himself. The hair's breadth was his
minimum until the microscope told him that there are animated creatures to
which one of the hairs of his head is a larger cylinder than is the trunk of the
giant California sequoia to him. He borrows his inch from the breadth of his
thumb, his palm and span from the width of his hand and the spread of his
fingers, his foot from the length of the organ so named; his cubit is the
distance from the tip of his middle finger to his elbow, and his fathom is the
space he can measure with his outstretched arms. [Footnote: The French
metrical system seems destined to be adopted throughout the civilized
world. It is indeed recommended by great advantages, but it is very
doubtful whether they are not more than counterbalanced by the selection of
too large a unit of measure, and by the inherent intractability of all decimal
systems with reference to fractional divisions. The experience of the whole
world has established the superior convenience of a smaller unit, such as the
braccio, the cubit, the foot, and the palm or span, and in practical life every
man finds that he haa much more frequent occasion to use a fraction than a
multiple of the metre. Of course, he must constantly employ numbers
expressive of several centimetres or millimetres instend of the name of a
single smaller unit than the metre. Besides, the metre is not divisible into
twelfths, eighths, sixths, or thirds, or the multiples of any of these
proportions, two of which at least—the eighth and the third—are of as
Page 204
frequent use as any other fractions. The adoption of a fourth of the earth's
circumference as a base for the new measures was itself a departure from
the decimal system. Had the Commissioners taken the entire circumference
as a base, and divided it into 100,000,000 instead of 10,000,000 parts, we
should have had a unit of about sixteen inches, which, as a compromise
between the foot and the cubit, would have been much better adapted to
universal use than so large a unit as the metre.] To a being who instinctively
finds the standard of all magnitudes in his own material frame, all objects
exceeding his own dimensions are absolutely great, all falling short of them
absolutely small. Hence we habitually regard the whale and the elephant as
essentially large and therefore important creatures, the animalcule as an
essentially small and therefore unimportant organism. But no geological
formation owes its origin to the labors or the remains of the huge mammal,
while the animalcule composes, or has furnished, the substance of strata
thousands of feet in thickness, and extending, in unbroken beds, over many
degrees of terrestrial surface. If man is destined to inhabit the earth much
longer, and to advance in natural knowledge with the rapidity which has
marked his progress in physical science for the last two or three centuries,
he will learn to put a wiser estimate on the works of creation, and will
derive not only great instruction from studying the ways of nature in her
obscurest, humblest walks, but great material advantage from stimulating
her productive energies in provinces of her empire hitherto regarded as
forever inaccessible, utterly barren. [Footnote: The fermentation of liquids,
and in many cases the decomposition of semi-solids, formerly supposed to
be owing purely to chemical action, are now ascribed by many chemists to
vital processes of living minute organisms, both vegetable and animal, and
consequently to physiological as well as to chemical forces. Even alcohol is
stated to be an animal product. The whole subject of animalcular, or rather
minute organic, life, has assumed a now and startling importance from the
recent researches of naturalists and physiologists, in the agency of such life,
circumference as a base for the new measures was itself a departure from
the decimal system. Had the Commissioners taken the entire circumference
as a base, and divided it into 100,000,000 instead of 10,000,000 parts, we
should have had a unit of about sixteen inches, which, as a compromise
between the foot and the cubit, would have been much better adapted to
universal use than so large a unit as the metre.] To a being who instinctively
finds the standard of all magnitudes in his own material frame, all objects
exceeding his own dimensions are absolutely great, all falling short of them
absolutely small. Hence we habitually regard the whale and the elephant as
essentially large and therefore important creatures, the animalcule as an
essentially small and therefore unimportant organism. But no geological
formation owes its origin to the labors or the remains of the huge mammal,
while the animalcule composes, or has furnished, the substance of strata
thousands of feet in thickness, and extending, in unbroken beds, over many
degrees of terrestrial surface. If man is destined to inhabit the earth much
longer, and to advance in natural knowledge with the rapidity which has
marked his progress in physical science for the last two or three centuries,
he will learn to put a wiser estimate on the works of creation, and will
derive not only great instruction from studying the ways of nature in her
obscurest, humblest walks, but great material advantage from stimulating
her productive energies in provinces of her empire hitherto regarded as
forever inaccessible, utterly barren. [Footnote: The fermentation of liquids,
and in many cases the decomposition of semi-solids, formerly supposed to
be owing purely to chemical action, are now ascribed by many chemists to
vital processes of living minute organisms, both vegetable and animal, and
consequently to physiological as well as to chemical forces. Even alcohol is
stated to be an animal product. The whole subject of animalcular, or rather
minute organic, life, has assumed a now and startling importance from the
recent researches of naturalists and physiologists, in the agency of such life,
Page 205
vegetable or animal, in exciting and communicating contagious diseases,
and it is extremely probable that what are vaguely called germs, to
whichever of the organic kingdoms they may be assigned, creatures
inhabiting various media, and capable of propagating their kind and rapidly
multiplying, are the true seeds of infection and death in the maladies now
called zymotic, as well perhaps as in many others.
The literature of this subject is now very voluminous. For observations
with high microscopic power on this subject, see Beale, Disease Germs,
their supposed Nature, and Disease Germs, their real Nature, both published
in London in 1870.
The increased frequency of typhoidal, zymotic, and malarious diseases in
some parts of the United States, and the now common occurrence of some
of them in districts where they were unknown forty years ago, are startling
facts, and it is a very interesting question how far man's acts or neglects
may have occasioned the change. See Third Anual Report of Massachusetts
State Board of Health for 1873. The causes and remedies of the insalubrity
of Rome and its environs have been for some time the object of careful
investigation, and many valuable reports have been published on the
subject. Among the most recent of these are: Relazione sulle condizioni
agrarie ed igieniche della Campagna di Roma, per Raffaele Pareto; Cenni
Storici sulla questione dell' Agro Romano di G. Guerzoni; Cenni sulle
condizioni Fisico-economiche di Roma per F. Giordano; and a very
important paper in the journal Lo Sperimentale for 1870, by Dr. D.
Pantaleoni.
There are climates, parts of California, for instance, where the flesh of
dead animals, freely exposed, shows no tendency to putrefaction but dries
up and may be almost indefinitely preserved in this condition. Is this owing
to the absence of destructive animalcular life in such localities, and has man
and it is extremely probable that what are vaguely called germs, to
whichever of the organic kingdoms they may be assigned, creatures
inhabiting various media, and capable of propagating their kind and rapidly
multiplying, are the true seeds of infection and death in the maladies now
called zymotic, as well perhaps as in many others.
The literature of this subject is now very voluminous. For observations
with high microscopic power on this subject, see Beale, Disease Germs,
their supposed Nature, and Disease Germs, their real Nature, both published
in London in 1870.
The increased frequency of typhoidal, zymotic, and malarious diseases in
some parts of the United States, and the now common occurrence of some
of them in districts where they were unknown forty years ago, are startling
facts, and it is a very interesting question how far man's acts or neglects
may have occasioned the change. See Third Anual Report of Massachusetts
State Board of Health for 1873. The causes and remedies of the insalubrity
of Rome and its environs have been for some time the object of careful
investigation, and many valuable reports have been published on the
subject. Among the most recent of these are: Relazione sulle condizioni
agrarie ed igieniche della Campagna di Roma, per Raffaele Pareto; Cenni
Storici sulla questione dell' Agro Romano di G. Guerzoni; Cenni sulle
condizioni Fisico-economiche di Roma per F. Giordano; and a very
important paper in the journal Lo Sperimentale for 1870, by Dr. D.
Pantaleoni.
There are climates, parts of California, for instance, where the flesh of
dead animals, freely exposed, shows no tendency to putrefaction but dries
up and may be almost indefinitely preserved in this condition. Is this owing
to the absence of destructive animalcular life in such localities, and has man
Page 206
any agency in the introduction and naturalization of these organisms in
regions previously not infested by them ]
CHAPTER III.
THE WOODS.
The habitable earth originally wooded—General meteorological
influence of the forest—Electrical action of trees—Chemical influence of
woods—Trees as protection against malaria—Trees as shelter to ground to
the leeward—Influence of the forest as inorganic on temperature—
Thermometrical action of trees as organic—Total influence of the forest on
temperature—Influence of forests as inorganic on humidity of air and earth
—Influence as organic—Balance of conflicting influences—Influence of
woods on precipitation—Total climatic action of the forest—Influence of
the forest on humidity of soil—The forest in winter—Summer rain,
importance of—Influence of the forest on the flow of springs—Influence of
the forest on inundations and torrents—Destructive action of torrents—
Floods of the Ardeche—Excavation by torrents—Extinction of torrents—
Crushing force of torrents—Transporting power of water—The Po and its
deposits—Mountain slides—Forest as protection against avalanches—
Minor uses of the forest—Small forest plants and vitality of seeds—Locusts
do not breed in forests—General functions of forest—General
consequences of destruction of—Due proportion of woodland—Proportion
of woodland in European countries—Forests of Great Britain—Forests of
France—Forests of Italy—Forests of Germany—Forests of United States—
American forest trees—European and American forest trees compared—
The forest does not furnish food for man—First removal of the forest—
Principal causes of destruction of forest—Destruction and protection of
forests by governments—Royal forests and game-laws—Effects of the
regions previously not infested by them ]
CHAPTER III.
THE WOODS.
The habitable earth originally wooded—General meteorological
influence of the forest—Electrical action of trees—Chemical influence of
woods—Trees as protection against malaria—Trees as shelter to ground to
the leeward—Influence of the forest as inorganic on temperature—
Thermometrical action of trees as organic—Total influence of the forest on
temperature—Influence of forests as inorganic on humidity of air and earth
—Influence as organic—Balance of conflicting influences—Influence of
woods on precipitation—Total climatic action of the forest—Influence of
the forest on humidity of soil—The forest in winter—Summer rain,
importance of—Influence of the forest on the flow of springs—Influence of
the forest on inundations and torrents—Destructive action of torrents—
Floods of the Ardeche—Excavation by torrents—Extinction of torrents—
Crushing force of torrents—Transporting power of water—The Po and its
deposits—Mountain slides—Forest as protection against avalanches—
Minor uses of the forest—Small forest plants and vitality of seeds—Locusts
do not breed in forests—General functions of forest—General
consequences of destruction of—Due proportion of woodland—Proportion
of woodland in European countries—Forests of Great Britain—Forests of
France—Forests of Italy—Forests of Germany—Forests of United States—
American forest trees—European and American forest trees compared—
The forest does not furnish food for man—First removal of the forest—
Principal causes of destruction of forest—Destruction and protection of
forests by governments—Royal forests and game-laws—Effects of the
Page 207
French revolution—Increased demand for lumber—Effects of burning
forest—Floating of timber—Restoration of the forest—Economy of the
forest—Forest legislation—Plantation of forests in America—Financial
results of forest plantations—Instability of American life.
The Habitable Earth originally Wooded.
There is good reason to believe that the surface of the habitable earth, in
all the climates and regions which have been the abodes of dense and
civilized populations, was, with few exceptions, already covered with a
forest growth when it first became the home of man. This we infer from the
extensive vegetable remains—trunks, branches, roots, fruits, seeds, and
leaves of trees—so often found in conjunction with works of primitive art,
in the boggy soil of districts where no forests appear to have existed within
the eras through which written annals reach; from ancient historical records,
which prove that large provinces, where the earth has long been wholly bare
of trees, were clothed with vast and almost unbroken woods when first
made known to Greek and Roman civilization; [Footnote: The recorded
evidence in support of the proposition in the text has been collected by L. F.
Alfred Maury, in his Histoire des grandes Forets de la Gauls et de l'ancienne
France, and by Becquerel, in his important work, Des climats et de
l'Influence qu'exercent les Sols boises et non boises, livre ii., chap. i. to iv.
We may rank among historical evidences on this point, if not technically
among historical records, old geographical names and terminations
etymologically indicating forest or grove, which are so common in many
parts of the Eastern Continent now entirely stripped of woods—such as, in
Southern Europe, Breuil, Broglio, Brolio, Brolo; in Northern, Bruhl, and the
endings -dean, -den, -don, -ham, -holt, -horst, -hurst, -lund, -shaw, -shot, -
skog, -skov, -wald, -weald, -wold, -wood.] and from the state of much of
North and of South America, as well as of many islands, when they were
forest—Floating of timber—Restoration of the forest—Economy of the
forest—Forest legislation—Plantation of forests in America—Financial
results of forest plantations—Instability of American life.
The Habitable Earth originally Wooded.
There is good reason to believe that the surface of the habitable earth, in
all the climates and regions which have been the abodes of dense and
civilized populations, was, with few exceptions, already covered with a
forest growth when it first became the home of man. This we infer from the
extensive vegetable remains—trunks, branches, roots, fruits, seeds, and
leaves of trees—so often found in conjunction with works of primitive art,
in the boggy soil of districts where no forests appear to have existed within
the eras through which written annals reach; from ancient historical records,
which prove that large provinces, where the earth has long been wholly bare
of trees, were clothed with vast and almost unbroken woods when first
made known to Greek and Roman civilization; [Footnote: The recorded
evidence in support of the proposition in the text has been collected by L. F.
Alfred Maury, in his Histoire des grandes Forets de la Gauls et de l'ancienne
France, and by Becquerel, in his important work, Des climats et de
l'Influence qu'exercent les Sols boises et non boises, livre ii., chap. i. to iv.
We may rank among historical evidences on this point, if not technically
among historical records, old geographical names and terminations
etymologically indicating forest or grove, which are so common in many
parts of the Eastern Continent now entirely stripped of woods—such as, in
Southern Europe, Breuil, Broglio, Brolio, Brolo; in Northern, Bruhl, and the
endings -dean, -den, -don, -ham, -holt, -horst, -hurst, -lund, -shaw, -shot, -
skog, -skov, -wald, -weald, -wold, -wood.] and from the state of much of
North and of South America, as well as of many islands, when they were
Page 208
discovered and colonized by the European race. [Footnote: The island of
Madeira, whose noble forests wore devastated by fire not Iong after its
colonization by European settlors, takes its name from the Portuguese word
tor wood.]
These evidences are strengthened by observation of the natural economy
of our time; for, whenever a tract of country once inhabited and cultivated
by man, is abandoned by him and by domestic animals, and surrendered to
the undisturbed influences of spontaneous nature, its soil sooner of later
clothes itself with herbaceous and arborescent plants, and, at no long
interval, with a dense forest growth. Indeed, upon surfaces of a certain
stability and not absolutely precipitous inclination the special conditions
required for the spontaneous propagation of trees may all be negatively
expressed and reduced to these three: exemption from defect or excess of
moisture, from perpetual frost, and from the depredations of man and
browsing quadrupeds. Where these requisites are secured, the hardest rock
is as certain to be overgrown with wood as the most fertile plain, though,
for obvious reasons, the process is slower in the former than in the latter
case. Lichens and mosses first prepare the way for a more highly organized
vegetation. They retain the moisture of rains and dews, and bring it to act,
in combination with the gases evolved by their organic processes, in
decomposing the surface of the rocks they cover; they arrest and confine the
dust which the wind scatters over them, and their final decay adds new
material to the soil already half formed beneath and upon them. A very thin
stratum of mould is sufficient for the germination of seeds of the hardy
evergreens and birches, the roots of which are often found in immediate
contact with the rock, supplying their trees with nourishment from a soil
deepened and enriched by the decomposition of their own foliage, or
sending out long rootlets into the surrounding earth in search of juices to
feed them.
Madeira, whose noble forests wore devastated by fire not Iong after its
colonization by European settlors, takes its name from the Portuguese word
tor wood.]
These evidences are strengthened by observation of the natural economy
of our time; for, whenever a tract of country once inhabited and cultivated
by man, is abandoned by him and by domestic animals, and surrendered to
the undisturbed influences of spontaneous nature, its soil sooner of later
clothes itself with herbaceous and arborescent plants, and, at no long
interval, with a dense forest growth. Indeed, upon surfaces of a certain
stability and not absolutely precipitous inclination the special conditions
required for the spontaneous propagation of trees may all be negatively
expressed and reduced to these three: exemption from defect or excess of
moisture, from perpetual frost, and from the depredations of man and
browsing quadrupeds. Where these requisites are secured, the hardest rock
is as certain to be overgrown with wood as the most fertile plain, though,
for obvious reasons, the process is slower in the former than in the latter
case. Lichens and mosses first prepare the way for a more highly organized
vegetation. They retain the moisture of rains and dews, and bring it to act,
in combination with the gases evolved by their organic processes, in
decomposing the surface of the rocks they cover; they arrest and confine the
dust which the wind scatters over them, and their final decay adds new
material to the soil already half formed beneath and upon them. A very thin
stratum of mould is sufficient for the germination of seeds of the hardy
evergreens and birches, the roots of which are often found in immediate
contact with the rock, supplying their trees with nourishment from a soil
deepened and enriched by the decomposition of their own foliage, or
sending out long rootlets into the surrounding earth in search of juices to
feed them.
Page 209
The eruptive matter of volcanoes, forbidding as is its aspect, does not
refuse nutriment to the woods. The refractory lava of Etna, it is true,
remains long barren, and that of the great eruption of 1669 is still almost
wholly devoid of vegetation.
[Footnote: Even the volcanic dust of Etna remains very long
unproductive. Near Nicolosi is a great extent of coarse black sand, thrown
out in 1669, which, for almost two centuries, lay entirely bare, and can be
made to grow plants only by artificial mixtures and much labor.
The increase in the price of wines, in consequence of the diminution of
the product from the grape disease, however, has brought even these ashes
under cultivation. "I found," says Waltershausen, referring to the years
1861-62, "plains of volcanic sand and half-subdued lava streams, which
twenty years ago lay utterly waste, now covered with fine vineyards. The
ashfield of ten square miles above Nicolosi, created by the eruption of
1669, which was entirely barren in 1835, is now planted with vines almost
to the summits of Monte Rosso, at a height of three thousand feet" Ueber
den Sicilianischen Ackerbau, p. 19.] But the cactus is making inroads even
here, while the volcanic sand and molten rock thrown out by Vesuvius soon
become productive. Before the great eruption of 1631 even the interior of
the crater was covered with vegetation. George Sandys, who visited
Vesuvius in 1611, after it had reposed for several centuries, found the throat
of the volcano at the bottom of the crater "almost choked with broken rocks
and trees that are falne therein." "Next to this," he continues, "the matter
thrown up is ruddy, light, and soft: more removed, blacke and ponderous:
the uttermost brow, that declineth like the seates in a theater, flourishing
with trees and excellent pasturage. The midst of the hill is shaded with
chestnut trees, and others bearing sundry fruits." [Footnote: A Relation of a
Journey Begun An. Dom. 1610, lib. 4, p. 260, edition of 1615. The
testimony of Sandys on this point is confirmed by that of Pighio, Braccini,
refuse nutriment to the woods. The refractory lava of Etna, it is true,
remains long barren, and that of the great eruption of 1669 is still almost
wholly devoid of vegetation.
[Footnote: Even the volcanic dust of Etna remains very long
unproductive. Near Nicolosi is a great extent of coarse black sand, thrown
out in 1669, which, for almost two centuries, lay entirely bare, and can be
made to grow plants only by artificial mixtures and much labor.
The increase in the price of wines, in consequence of the diminution of
the product from the grape disease, however, has brought even these ashes
under cultivation. "I found," says Waltershausen, referring to the years
1861-62, "plains of volcanic sand and half-subdued lava streams, which
twenty years ago lay utterly waste, now covered with fine vineyards. The
ashfield of ten square miles above Nicolosi, created by the eruption of
1669, which was entirely barren in 1835, is now planted with vines almost
to the summits of Monte Rosso, at a height of three thousand feet" Ueber
den Sicilianischen Ackerbau, p. 19.] But the cactus is making inroads even
here, while the volcanic sand and molten rock thrown out by Vesuvius soon
become productive. Before the great eruption of 1631 even the interior of
the crater was covered with vegetation. George Sandys, who visited
Vesuvius in 1611, after it had reposed for several centuries, found the throat
of the volcano at the bottom of the crater "almost choked with broken rocks
and trees that are falne therein." "Next to this," he continues, "the matter
thrown up is ruddy, light, and soft: more removed, blacke and ponderous:
the uttermost brow, that declineth like the seates in a theater, flourishing
with trees and excellent pasturage. The midst of the hill is shaded with
chestnut trees, and others bearing sundry fruits." [Footnote: A Relation of a
Journey Begun An. Dom. 1610, lib. 4, p. 260, edition of 1615. The
testimony of Sandys on this point is confirmed by that of Pighio, Braccini,
Page 210
Magliocco, Salimbeni, and Nicola di Rubco, all cited by Roth, Der Vesuv.,
p. 9. There is some uncertainty about the date of the last eruption previous
to the great one of 163l. Ashes, though not lava, appear to have been thrown
out about the year 1500, and some chroniclers have recorded an eruption in
the year 1306; but this seems to be an error for 1036, when a great quantity
of lava was ejected. In 1130, ashes were thrown out for many days. I take
these dates from the work of Roth just cited.] I am convinced that forests
would soon cover many parts of the Arabian and African deserts, if man and
domestic animals, especially the goat and the camel, were banished from
them. The hard palate and tongue and strong teeth and jaws of this latter
quadruped enable him to break off and masticate tough and thorny branches
as large as the finger. He is particularly fond of the smaller twigs, leaves,
and seed-pods of the sont and other acacias, which, like the American
Robinia, thrive well on dry and sandy soils, and he spares no tree the
branches of which are within his reach, except, if I remember right, the
tamarisk that produces manna. Young trees sprout plentifully around the
springs and along the winter water-courses of the desert, and these are just
the halting stations of the caravans and their routes of travel. In the shade of
these trees, annual grasses and perennial shrubs shoot up, but are mown
down by the hungry cattle of the Bedouin, as fast as they grow. A few years
of undisturbed vegetation would suffice to cover such points with groves,
and these would gradually extend themselves over soils where now scarcely
any green thing but the bitter colocynth and the poisonous foxglove is ever
seen.
General Meteorological Influence of the Forest.
The physico-geographical influence of forests may be divided into two
great classes, each having an important influence on vegetable and on
animal life in all their manifestations, as well as on every branch of rural
p. 9. There is some uncertainty about the date of the last eruption previous
to the great one of 163l. Ashes, though not lava, appear to have been thrown
out about the year 1500, and some chroniclers have recorded an eruption in
the year 1306; but this seems to be an error for 1036, when a great quantity
of lava was ejected. In 1130, ashes were thrown out for many days. I take
these dates from the work of Roth just cited.] I am convinced that forests
would soon cover many parts of the Arabian and African deserts, if man and
domestic animals, especially the goat and the camel, were banished from
them. The hard palate and tongue and strong teeth and jaws of this latter
quadruped enable him to break off and masticate tough and thorny branches
as large as the finger. He is particularly fond of the smaller twigs, leaves,
and seed-pods of the sont and other acacias, which, like the American
Robinia, thrive well on dry and sandy soils, and he spares no tree the
branches of which are within his reach, except, if I remember right, the
tamarisk that produces manna. Young trees sprout plentifully around the
springs and along the winter water-courses of the desert, and these are just
the halting stations of the caravans and their routes of travel. In the shade of
these trees, annual grasses and perennial shrubs shoot up, but are mown
down by the hungry cattle of the Bedouin, as fast as they grow. A few years
of undisturbed vegetation would suffice to cover such points with groves,
and these would gradually extend themselves over soils where now scarcely
any green thing but the bitter colocynth and the poisonous foxglove is ever
seen.
General Meteorological Influence of the Forest.
The physico-geographical influence of forests may be divided into two
great classes, each having an important influence on vegetable and on
animal life in all their manifestations, as well as on every branch of rural
Page 211
economy and productive industry, and, therefore, on all the material
interests of man. The first respects the meteorology of the countries exposed
to the action of these influences; the second, their superficial geography, or,
in other words, the configuration, consistence, and clothing of their surface.
For reasons assigned in the first chapter, and for others that will appear
hereafter, the meteorological or climatic branch of the subject is the most
obscure, and the conclusions of physicists respecting it are, in a great
degree, inferential only, not founded on experiment or direct observation.
They are, as might be expected, somewhat discordant, though one general
result is almost universally accepted, and seems indeed too well supported
to admit of serious question, and it may be considered as established that
forests tend to mitigate, at least within their own precincts, extremes of
temperature, humidity, and drought. By what precise agencies the
meteorological effects of the forest are produced we cannot say, because
elements of totally unknown value enter into its action, and because the
relative intensity of better understood causes cannot be measured or
compared. I shall not occupy much space in discussing questions which at
present admit of no solution, but I propose to notice all the known forces
whose concurrent or conflicting energies contribute to the general result,
and to point out, in some detail, the value of those influeuces whose mode
of action has been ascertained. Electrical Influence of Trees. The properties
of trees, singly and in groups, as exciters or conductors of electricity, and
their consequent influence upon the electrical state of the atmosphere, do
not appear to have been much investigated; and the conditions of the forest
itself are so variable and so complicated, that the solution of any general
problem respecting its electrical influence would be a matter of extreme
difficulty. It is, indeed, impossible to suppose that a dense cloud, a sea of
vapor, can pass over miles of surface bristling with good conductors,
without undergoing and producing some change of electrical condition.
Hypothetical cases may be put in which the character of the change could
interests of man. The first respects the meteorology of the countries exposed
to the action of these influences; the second, their superficial geography, or,
in other words, the configuration, consistence, and clothing of their surface.
For reasons assigned in the first chapter, and for others that will appear
hereafter, the meteorological or climatic branch of the subject is the most
obscure, and the conclusions of physicists respecting it are, in a great
degree, inferential only, not founded on experiment or direct observation.
They are, as might be expected, somewhat discordant, though one general
result is almost universally accepted, and seems indeed too well supported
to admit of serious question, and it may be considered as established that
forests tend to mitigate, at least within their own precincts, extremes of
temperature, humidity, and drought. By what precise agencies the
meteorological effects of the forest are produced we cannot say, because
elements of totally unknown value enter into its action, and because the
relative intensity of better understood causes cannot be measured or
compared. I shall not occupy much space in discussing questions which at
present admit of no solution, but I propose to notice all the known forces
whose concurrent or conflicting energies contribute to the general result,
and to point out, in some detail, the value of those influeuces whose mode
of action has been ascertained. Electrical Influence of Trees. The properties
of trees, singly and in groups, as exciters or conductors of electricity, and
their consequent influence upon the electrical state of the atmosphere, do
not appear to have been much investigated; and the conditions of the forest
itself are so variable and so complicated, that the solution of any general
problem respecting its electrical influence would be a matter of extreme
difficulty. It is, indeed, impossible to suppose that a dense cloud, a sea of
vapor, can pass over miles of surface bristling with good conductors,
without undergoing and producing some change of electrical condition.
Hypothetical cases may be put in which the character of the change could
Page 212
be deduced from the known laws of electrical action. But in actual nature,
the elements are too numerous for us to seize. The true electrical condition
of neither cloud nor forest could be known, and it could seldom be
predicted whether the vapors would be dissolved as they floated over the
wood, or discharged upon it in a deluge of rain. With regard to possible
electrical influences of the forest, wider still in their range of action, the
uncertainty is even greater. The data which alone could lead to positive, or
even probable, conclusions are wanting, and we should, therefore, only
embarrass our argument by any attempt to discuss this meteorological
element, important as it may be, in its relations of cause and effect to more
familiar and bettor understood meteoric phenomena. It may, however, be
observed that hail-storms—which were once generally supposed, and are
still held by many, to be produced by a specific electrical action, and which,
at least, appear to be always accompanied by electrical disturbances—are
believed, in all countries particularly exposed to that scourge, to have
become more frequent and destructive in proportion as the forests have
been cleared. Caimi observes: "When the chains of the Alps and the
Apennines had not yet been stripped of their magnificent crown of woods,
the May hail, which now desolates the fertile plains of Lombardy, was
much less frequent; but since the general prostration of the forest, these
tempests are laying waste even the mountain-soils whose older inhabitants
scarcely knew this plague. [Footnote: There are, in Northern Italy and in
Switzerland, joint-stock companies which insure against damage by hail, as
well as by fire and lightning. Between the years 1854 and 1861, a single
one of these companies, La Riunione Adriatica, paid, for damage by hail in
Piedmont, Venetian Lombardy, and the Duchy of Parma, above 6,500,000
francs, or nearly $200,000 per year.] The paragrandini, [Footnote: The
paragrandine, or, as it is called in French, the paragrele, is a species of
conductor by which it has been hoped to protect the harvests in countries
particularly exposed to damage by hail. It was at first proposed to employ
the elements are too numerous for us to seize. The true electrical condition
of neither cloud nor forest could be known, and it could seldom be
predicted whether the vapors would be dissolved as they floated over the
wood, or discharged upon it in a deluge of rain. With regard to possible
electrical influences of the forest, wider still in their range of action, the
uncertainty is even greater. The data which alone could lead to positive, or
even probable, conclusions are wanting, and we should, therefore, only
embarrass our argument by any attempt to discuss this meteorological
element, important as it may be, in its relations of cause and effect to more
familiar and bettor understood meteoric phenomena. It may, however, be
observed that hail-storms—which were once generally supposed, and are
still held by many, to be produced by a specific electrical action, and which,
at least, appear to be always accompanied by electrical disturbances—are
believed, in all countries particularly exposed to that scourge, to have
become more frequent and destructive in proportion as the forests have
been cleared. Caimi observes: "When the chains of the Alps and the
Apennines had not yet been stripped of their magnificent crown of woods,
the May hail, which now desolates the fertile plains of Lombardy, was
much less frequent; but since the general prostration of the forest, these
tempests are laying waste even the mountain-soils whose older inhabitants
scarcely knew this plague. [Footnote: There are, in Northern Italy and in
Switzerland, joint-stock companies which insure against damage by hail, as
well as by fire and lightning. Between the years 1854 and 1861, a single
one of these companies, La Riunione Adriatica, paid, for damage by hail in
Piedmont, Venetian Lombardy, and the Duchy of Parma, above 6,500,000
francs, or nearly $200,000 per year.] The paragrandini, [Footnote: The
paragrandine, or, as it is called in French, the paragrele, is a species of
conductor by which it has been hoped to protect the harvests in countries
particularly exposed to damage by hail. It was at first proposed to employ
Page 213
for this purpose poles supporting sheaves of straw connected with the
ground by the same material; but the experiment was afterwards tried in
Lombardy on a large scale, with more perfect electrical conductors,
consisting of poles secured to the top of tall trees and provided with a
pointed wire entering the ground and reaching above the top of the pole. It
was at first thought that this apparatus, erected at numerous points over an
extent of several miles, was of some service as a protection against hail, but
this opinion was soon disputed, and does not appear to be supported by
well-ascertained facts. The question of a repetition of the experiment over a
wide area has been again agitated within a very few years in Lombardy; but
the doubts expressed by very able physicists as to its efficacy, and as to the
point whether hail is an electrical phenomenon, have discouraged its
advocates from attempting it.] which the learned curate of Rivolta advised
to erect, with sheaves of straw set up vertically, over a great extent of
cultivated country, are but a Liliputian imago of the vast paragrandini,
pines, larches, and fire, which nature had planted by millions on the crests
and ridges of the Alps and the Apennines." [Footnote: Cenni sulla
Importansa e Coltura dei Boschi, p. 6.] "Electrical action being diminished,"
says Meguscher, "and the rapid congelation of vapors by the abstraction of
heat being impeded by the influence of the woods, it is rare that hail or
waterspouts are produced within the precincts of a large forest when it is
assailed by the tempest." [Footnote: Memoria sui Boschi, etc., p. 44.]
Arthur Young was told that since the forests which covered the mountains
between the Riviera and the county of Montferrat had disappeared, hail had
become more destructive in the district of Acqui, [Footnote: Travels in Italy,
chap. iii.] and a similar increase in the frequency and violence of hail-
storms in the neighborhood of Saluzzo and Mondovi, the lower part of the
Valtelline, and the territory of Verona and Vicenza, is probably to be
ascribed to a similar cause. [Footnote: Le Alpi che cingono l'Italia, i., p.
377. See "On the Influence of the Forest in Preventing Hail-storms," a paper
ground by the same material; but the experiment was afterwards tried in
Lombardy on a large scale, with more perfect electrical conductors,
consisting of poles secured to the top of tall trees and provided with a
pointed wire entering the ground and reaching above the top of the pole. It
was at first thought that this apparatus, erected at numerous points over an
extent of several miles, was of some service as a protection against hail, but
this opinion was soon disputed, and does not appear to be supported by
well-ascertained facts. The question of a repetition of the experiment over a
wide area has been again agitated within a very few years in Lombardy; but
the doubts expressed by very able physicists as to its efficacy, and as to the
point whether hail is an electrical phenomenon, have discouraged its
advocates from attempting it.] which the learned curate of Rivolta advised
to erect, with sheaves of straw set up vertically, over a great extent of
cultivated country, are but a Liliputian imago of the vast paragrandini,
pines, larches, and fire, which nature had planted by millions on the crests
and ridges of the Alps and the Apennines." [Footnote: Cenni sulla
Importansa e Coltura dei Boschi, p. 6.] "Electrical action being diminished,"
says Meguscher, "and the rapid congelation of vapors by the abstraction of
heat being impeded by the influence of the woods, it is rare that hail or
waterspouts are produced within the precincts of a large forest when it is
assailed by the tempest." [Footnote: Memoria sui Boschi, etc., p. 44.]
Arthur Young was told that since the forests which covered the mountains
between the Riviera and the county of Montferrat had disappeared, hail had
become more destructive in the district of Acqui, [Footnote: Travels in Italy,
chap. iii.] and a similar increase in the frequency and violence of hail-
storms in the neighborhood of Saluzzo and Mondovi, the lower part of the
Valtelline, and the territory of Verona and Vicenza, is probably to be
ascribed to a similar cause. [Footnote: Le Alpi che cingono l'Italia, i., p.
377. See "On the Influence of the Forest in Preventing Hail-storms," a paper
Page 214
by Becquerel, in the Memoires de l'Academie des Sciences, vol. xxxv. The
conclusion of this eminent physicist is, that woods do excercise, both within
their own limits and in their vicinity, the influence popularly ascribed to
them in this respect, and that the effect is probably produced partly by
mechanical and partly by electrical action.] Chemical Influence of the
Forest. We know that the air in a close apartment is appreciably affected
through the inspiration and expiration of gases by plants growing in it. The
same operations are performed on a gigantic scale by the forest, and it has
even been supposed that the absorption of carbon, by the rank vegetation of
earlier geological periods, occasioned a permanent change in the
constitution of the terrestrial atmosphere. [Footnote: "Long before the
appearance of man, … they [the forests] had robbed the atmosphere of the
enormous quantity of carbonic acid it contained, and thereby transformed it
into respirable air. Trees heaped upon trees had already filled up the ponds
and marshes, and buried with them in the bowels of the earth—to restore it
to us, after thousands of ages, in the form of bituminous coal and of
anthracite—the carbon which was destined to become, by this wonderful
condensation, a precious store of future wealth."—Clave, Etudes sur
l'Economie Forestiere, p. 13.
This opinion of the modification of the atmosphere by vegetation is
contested.
Mossman ascribes the great luxuriance and special character of the
Australian and New Zealand forests, as well as other peculiarities of the
vegetation of the Southern hemisphere, to a supposed larger proportion of
carbon in the atmosphere of that hemisphere, though the fact of such excess
does not appear to have been established by chemical analysis. Mossman,
Origin of the Seasons. Edinburgh, 1869. Chaps. xvi. and xvil.] To the
effects thus produced are to be added those of the ultimate gaseous
decomposition of the vast vegetable mass annually shed by trees, and of
conclusion of this eminent physicist is, that woods do excercise, both within
their own limits and in their vicinity, the influence popularly ascribed to
them in this respect, and that the effect is probably produced partly by
mechanical and partly by electrical action.] Chemical Influence of the
Forest. We know that the air in a close apartment is appreciably affected
through the inspiration and expiration of gases by plants growing in it. The
same operations are performed on a gigantic scale by the forest, and it has
even been supposed that the absorption of carbon, by the rank vegetation of
earlier geological periods, occasioned a permanent change in the
constitution of the terrestrial atmosphere. [Footnote: "Long before the
appearance of man, … they [the forests] had robbed the atmosphere of the
enormous quantity of carbonic acid it contained, and thereby transformed it
into respirable air. Trees heaped upon trees had already filled up the ponds
and marshes, and buried with them in the bowels of the earth—to restore it
to us, after thousands of ages, in the form of bituminous coal and of
anthracite—the carbon which was destined to become, by this wonderful
condensation, a precious store of future wealth."—Clave, Etudes sur
l'Economie Forestiere, p. 13.
This opinion of the modification of the atmosphere by vegetation is
contested.
Mossman ascribes the great luxuriance and special character of the
Australian and New Zealand forests, as well as other peculiarities of the
vegetation of the Southern hemisphere, to a supposed larger proportion of
carbon in the atmosphere of that hemisphere, though the fact of such excess
does not appear to have been established by chemical analysis. Mossman,
Origin of the Seasons. Edinburgh, 1869. Chaps. xvi. and xvil.] To the
effects thus produced are to be added those of the ultimate gaseous
decomposition of the vast vegetable mass annually shed by trees, and of
Page 215
their trunks and branches when they fall a prey to time. But the quantity of
gases thus abstracted from and restored to the atmosphere is inconsiderable
—infinitesimal, one might almost say—in comparison with the ocean of air
from which they are drawn and to which they return; and though the
exhalations from bogs, and other low grounds covered with decaying
vegetable matter, are highly deleterious to human health, yet, in general, the
air of the forest is hardly chemically distinguishable from that of the sand
plains, and we can as little trace the influence of the woods in the analysis
of the atmosphere, as we can prove that the mineral ingredients of
landsprings sensibly affect the chemistry of the sea. I may, then, properly
dismiss the chemical, as I have done the electrical, influences of the forest,
and treat them both alike, if not as unimportant agencies, at least as
quantities of unknown value in our meteorological equation. [Footnote:
Schacht ascribes to the forest a specific, if not a measurable, influence upon
the constitution of the atmosphere. "Plants imbibe from the air carbonic
acid and other gaseous or volatile products exhaled by animals or developed
by the natural phenomena of decomposition. On the other hand, the
vegetable pours into the atmosphere oxygen, which is taken up by animals
and appropriated by them. The tree, by means of its leaves and its young
herbaceous twigs, presents a considerable surface for absorption and
evaporation; it abstracts the carbon of carbonic acid, and solidifies it in
wood, fecula, and a multitude of other compounds. The result is that a forest
withdraws from the air, by its great absorbent surface, much more gas than
meadows or cultivated fields, and exhales proportionally a considerably
greater quantity of oxygen. The influence of the forests on the chemical
composition of the atmosphere is, in a word, of the highest importance."—
Les Arbres, p. 111.
See on this subject a paper by J. Jamin, in the Revue des Deux Mondes
for Sept. 15, 1864; and, on the effects of human industry on the atmosphere,
an article in Aus der Natur, vol. 29, 1864, pp. 443, 449, 465, et seq. See also
gases thus abstracted from and restored to the atmosphere is inconsiderable
—infinitesimal, one might almost say—in comparison with the ocean of air
from which they are drawn and to which they return; and though the
exhalations from bogs, and other low grounds covered with decaying
vegetable matter, are highly deleterious to human health, yet, in general, the
air of the forest is hardly chemically distinguishable from that of the sand
plains, and we can as little trace the influence of the woods in the analysis
of the atmosphere, as we can prove that the mineral ingredients of
landsprings sensibly affect the chemistry of the sea. I may, then, properly
dismiss the chemical, as I have done the electrical, influences of the forest,
and treat them both alike, if not as unimportant agencies, at least as
quantities of unknown value in our meteorological equation. [Footnote:
Schacht ascribes to the forest a specific, if not a measurable, influence upon
the constitution of the atmosphere. "Plants imbibe from the air carbonic
acid and other gaseous or volatile products exhaled by animals or developed
by the natural phenomena of decomposition. On the other hand, the
vegetable pours into the atmosphere oxygen, which is taken up by animals
and appropriated by them. The tree, by means of its leaves and its young
herbaceous twigs, presents a considerable surface for absorption and
evaporation; it abstracts the carbon of carbonic acid, and solidifies it in
wood, fecula, and a multitude of other compounds. The result is that a forest
withdraws from the air, by its great absorbent surface, much more gas than
meadows or cultivated fields, and exhales proportionally a considerably
greater quantity of oxygen. The influence of the forests on the chemical
composition of the atmosphere is, in a word, of the highest importance."—
Les Arbres, p. 111.
See on this subject a paper by J. Jamin, in the Revue des Deux Mondes
for Sept. 15, 1864; and, on the effects of human industry on the atmosphere,
an article in Aus der Natur, vol. 29, 1864, pp. 443, 449, 465, et seq. See also
Page 216
Alfred Maury, Les Forete de la Gaule, p. 107.] Our inquiries upon this
branch of the subject will accordingly be limited to the thermometrical and
hygrometrical influences of the woods. There is, however, a special
protective function of the forest, perhaps, in part, of a chemical nature,
which may be noticed here.
Trees as a Protection against Malaria.
The influence of forests in preventing the diffusion of miasmatic vapors
is not a matter of familiar observation, and perhaps it does not come strictly
within the sphere of the present inquiry, but its importance will justify me in
devoting some space to the subject. "It has been observed" (I quote from
Becquerel) "that humid air, charged with miasmata, is deprived of them in
passing through the forest. Rigaud de Lille observed localities in Italy
where the interposition of a screen of trees preserved everything beyond it,
while the unprotected grounds were subject to fevers." [Footnote:
Becquerel, Des Climats, etc., p. 9.] Few European countries present better
opportunities for observation on this point than Italy, because in that
kingdom the localities exposed to miasmatic exhalations are numerous, and
belts of trees, if not forests, are of so frequent occurrence that their efficacy
in this respect can be easily tested. The belief that rows of trees afford an
important protection against malarious influences is very general among
Italians best qualified by intelligence and professional experience to judge
upon the subject. The commissioners, appointed to report on the measures
to be adopted for the improvement of the Tuscan Maremme, advised the
planting of three or four rows of poplars, Populus alla, in such directions as
to obstruct the currents of air from malarious localities, and thus intercept a
great proportion of the pernicious exhalations." [Footnote: Salvagnoli,
Rapporto sul Bonificamento delle Maremme Toscane, pp. xii., 124.] Maury
believed that a few rows of sunflowers, planted between the Washington
Observatory and the marshy banks of the Potomac, had saved the inmates
branch of the subject will accordingly be limited to the thermometrical and
hygrometrical influences of the woods. There is, however, a special
protective function of the forest, perhaps, in part, of a chemical nature,
which may be noticed here.
Trees as a Protection against Malaria.
The influence of forests in preventing the diffusion of miasmatic vapors
is not a matter of familiar observation, and perhaps it does not come strictly
within the sphere of the present inquiry, but its importance will justify me in
devoting some space to the subject. "It has been observed" (I quote from
Becquerel) "that humid air, charged with miasmata, is deprived of them in
passing through the forest. Rigaud de Lille observed localities in Italy
where the interposition of a screen of trees preserved everything beyond it,
while the unprotected grounds were subject to fevers." [Footnote:
Becquerel, Des Climats, etc., p. 9.] Few European countries present better
opportunities for observation on this point than Italy, because in that
kingdom the localities exposed to miasmatic exhalations are numerous, and
belts of trees, if not forests, are of so frequent occurrence that their efficacy
in this respect can be easily tested. The belief that rows of trees afford an
important protection against malarious influences is very general among
Italians best qualified by intelligence and professional experience to judge
upon the subject. The commissioners, appointed to report on the measures
to be adopted for the improvement of the Tuscan Maremme, advised the
planting of three or four rows of poplars, Populus alla, in such directions as
to obstruct the currents of air from malarious localities, and thus intercept a
great proportion of the pernicious exhalations." [Footnote: Salvagnoli,
Rapporto sul Bonificamento delle Maremme Toscane, pp. xii., 124.] Maury
believed that a few rows of sunflowers, planted between the Washington
Observatory and the marshy banks of the Potomac, had saved the inmates
Page 217
of that establishment from the intermittent fevers to which they had been
formerly liable. Maury's experiments have been repeated in Italy. Large
plantations of sunflowers have been made upon the alluvial deposits of the
Oglio, above its entrance into the Lake of Iseo, near Pisogne, and it is said
with favorable results to the health of the neighborhood. [Footnote: Il
Politecnico, Milano, Aprile e Maggio, 1863, p. 35.] In fact, the generally
beneficial effects of a forest wall or other vegetable screen, as a protection
against noxious exhalations from marshes or other sources of disease,
situated to the windward of them, are very commonly admitted.
It is argued that, in these cases, the foliage of trees and of other
vegetables exercises a chemical as well as a mechanical effect upon the
atmosphere, and some, who allow that forests may intercept the circulation
of the miasmatic effluvia of swampy soils, or even render them harmless by
decomposing them, contend, nevertheless, that they are themselves active
causes of the production of malaria. The subject has been a good deal
discussed in Italy, and there is some reason to think that under special
circumstances the influence of the forest in this respect may be prejudicial
rather than salutary, though this does not appear to be generally the case.
[Footnote: Salvagnoli, Memorie sulle Maremme Toscane, pp. 213, 214. The
sanitary action of the forest has been lately matter of much attention in
Italy. See Rendiconti del Congresso Medico del 1869 a Firenze, and
especially the important observations of Selmi, Il Miasma Palustre, Padua,
1870, pp. 100 et seq. This action is held by this able writer to be almost
wholly chemical, and he earnestly recommends the plantation of groves, at
least of belts of trees, as an effectual protection against the miasmatic
influence of marshes. Very interesting observations on this point will be
found in Ebermayer, Die Physikalischen Einwirkungen des Waldes,
Aschaffenburg, 1873, B. I., pp. 237 et seq., where great importance is
ascribed to the development of ozone by the chemical action of the forest.
The beneficial influence of the ozone of the forest atmosphere on the
formerly liable. Maury's experiments have been repeated in Italy. Large
plantations of sunflowers have been made upon the alluvial deposits of the
Oglio, above its entrance into the Lake of Iseo, near Pisogne, and it is said
with favorable results to the health of the neighborhood. [Footnote: Il
Politecnico, Milano, Aprile e Maggio, 1863, p. 35.] In fact, the generally
beneficial effects of a forest wall or other vegetable screen, as a protection
against noxious exhalations from marshes or other sources of disease,
situated to the windward of them, are very commonly admitted.
It is argued that, in these cases, the foliage of trees and of other
vegetables exercises a chemical as well as a mechanical effect upon the
atmosphere, and some, who allow that forests may intercept the circulation
of the miasmatic effluvia of swampy soils, or even render them harmless by
decomposing them, contend, nevertheless, that they are themselves active
causes of the production of malaria. The subject has been a good deal
discussed in Italy, and there is some reason to think that under special
circumstances the influence of the forest in this respect may be prejudicial
rather than salutary, though this does not appear to be generally the case.
[Footnote: Salvagnoli, Memorie sulle Maremme Toscane, pp. 213, 214. The
sanitary action of the forest has been lately matter of much attention in
Italy. See Rendiconti del Congresso Medico del 1869 a Firenze, and
especially the important observations of Selmi, Il Miasma Palustre, Padua,
1870, pp. 100 et seq. This action is held by this able writer to be almost
wholly chemical, and he earnestly recommends the plantation of groves, at
least of belts of trees, as an effectual protection against the miasmatic
influence of marshes. Very interesting observations on this point will be
found in Ebermayer, Die Physikalischen Einwirkungen des Waldes,
Aschaffenburg, 1873, B. I., pp. 237 et seq., where great importance is
ascribed to the development of ozone by the chemical action of the forest.
The beneficial influence of the ozone of the forest atmosphere on the
Page 218
human system is, however, questioned by some observers. See also the able
memoir: Del Miasma vegetale e delle Malattis Miasmatiche of Dr D.
Pantaleoni in Lo Sperimentale, vol. xxii., 1870.
The necessity of such hygienic improvements as shall render the new
capital of Italy a salubrious residence gives great present importance to this
question, and it is much to be hoped that the Agro Romano, as well as more
distant parts of the Campagna, will soon be dotted with groves and
traversed by files of rapidly growing trees. Many forest trees grow with
great luxuriance in Italy, and a moderate expense in plantation would in a
very few years determine whether any amelioration of the sanitary
condition of Rome can be expected from this measure.
It is said by recent writers that in India the villages of the natives and the
encampments of European troops, situated in the midst or in the
neighborhood of groves and of forests, are exempt from cholera. Similar
observations were also made in 18S4 in Germany when this terrible disease
was raging there. It is hence inferred that forests prevent the spreading of
this malady, or rather the development of those unknown influences of
which cholera is the result. These influences, if we may believe certain able
writers on medical subjects, are telluric rather than meteoric; and they
regard it as probable that the uniform moisture of soil in forests may be the
immediate cause of the immunity enjoyed by such localities. See an article
by Pettenkofer in the Sud-Deutsche Presse, August, 1869; and the
observations of Ebermayer in the work above quoted, pp. 246 et seq.
In Australia and New Zealand, as well as generally in the Southern
Hemisphere, the indigenous trees are all evergreens, and even deciduous
trees introduced from the other side of the equator become evergreen. In
those regions, even in the most swampy localities, malarious diseases are
nearly, if not altogether, unknown. Is this most important fact due to the
memoir: Del Miasma vegetale e delle Malattis Miasmatiche of Dr D.
Pantaleoni in Lo Sperimentale, vol. xxii., 1870.
The necessity of such hygienic improvements as shall render the new
capital of Italy a salubrious residence gives great present importance to this
question, and it is much to be hoped that the Agro Romano, as well as more
distant parts of the Campagna, will soon be dotted with groves and
traversed by files of rapidly growing trees. Many forest trees grow with
great luxuriance in Italy, and a moderate expense in plantation would in a
very few years determine whether any amelioration of the sanitary
condition of Rome can be expected from this measure.
It is said by recent writers that in India the villages of the natives and the
encampments of European troops, situated in the midst or in the
neighborhood of groves and of forests, are exempt from cholera. Similar
observations were also made in 18S4 in Germany when this terrible disease
was raging there. It is hence inferred that forests prevent the spreading of
this malady, or rather the development of those unknown influences of
which cholera is the result. These influences, if we may believe certain able
writers on medical subjects, are telluric rather than meteoric; and they
regard it as probable that the uniform moisture of soil in forests may be the
immediate cause of the immunity enjoyed by such localities. See an article
by Pettenkofer in the Sud-Deutsche Presse, August, 1869; and the
observations of Ebermayer in the work above quoted, pp. 246 et seq.
In Australia and New Zealand, as well as generally in the Southern
Hemisphere, the indigenous trees are all evergreens, and even deciduous
trees introduced from the other side of the equator become evergreen. In
those regions, even in the most swampy localities, malarious diseases are
nearly, if not altogether, unknown. Is this most important fact due to the
Page 219
persistence of the foliage Mossman, Origin of Climates, pp. 374, 393, 410,
425, et seq.] It is, at all events, well known that the great swamps of
Virginia and the Carolinas, in climates nearly similar to that of Italy, are
healthy even to the white man, so long as the forests in and around them
remain, but become very insalubrious when the woods are felled. [Footnote:
Except in the seething marshes of northern tropical and subtropical regions,
where vegetable decay is extremely rapid, the uniformity of temperature
and of atmospheric humidity renders all forests eminently healthful. See
Hohensten's observations on this subject, Der Wald, p. 41; also A. Maury,
Les Forets de la Gaule, p. 7.
The flat and marshy district of the Sologne in France was salubrious until
its woods were felled. It then became pestilential, but within the last few
years its healthfulness has been restored by forest plantations. Jules Clave
in Revue des Deux Mondes for 1st March, 1866, p. 209. There is no
question that open squares and parks conduce to the salubrity of cities, and
many observers are of opinion that the trees and other vegetables with
which such grounds are planted contribute essentially to their beneficial
influence. See an article in Aus der Natur, xxii, p. 813.]
Trees as Shelter to Ground to the Leeward.
As a mechanical obstruction, trees impede the passage of air-currents
over the ground, which, as is well known, is one of the most efficient agents
in promoting evaporation and the refrigeration resulting from it. [Footnote:
It is perhaps too much to say that the influence of trees upon the wind is
strictly limited to the mechanical resistance of their trunks, branches, and
foliage. So far as the forest, by dead or by living action, raises or lowers the
temperature of the air within it, so far it creates upward or downward
currents in the atmosphere above it, and, consequently, a flow of air towards
or from itself. These air-streams have a certain, though doubtless a very
425, et seq.] It is, at all events, well known that the great swamps of
Virginia and the Carolinas, in climates nearly similar to that of Italy, are
healthy even to the white man, so long as the forests in and around them
remain, but become very insalubrious when the woods are felled. [Footnote:
Except in the seething marshes of northern tropical and subtropical regions,
where vegetable decay is extremely rapid, the uniformity of temperature
and of atmospheric humidity renders all forests eminently healthful. See
Hohensten's observations on this subject, Der Wald, p. 41; also A. Maury,
Les Forets de la Gaule, p. 7.
The flat and marshy district of the Sologne in France was salubrious until
its woods were felled. It then became pestilential, but within the last few
years its healthfulness has been restored by forest plantations. Jules Clave
in Revue des Deux Mondes for 1st March, 1866, p. 209. There is no
question that open squares and parks conduce to the salubrity of cities, and
many observers are of opinion that the trees and other vegetables with
which such grounds are planted contribute essentially to their beneficial
influence. See an article in Aus der Natur, xxii, p. 813.]
Trees as Shelter to Ground to the Leeward.
As a mechanical obstruction, trees impede the passage of air-currents
over the ground, which, as is well known, is one of the most efficient agents
in promoting evaporation and the refrigeration resulting from it. [Footnote:
It is perhaps too much to say that the influence of trees upon the wind is
strictly limited to the mechanical resistance of their trunks, branches, and
foliage. So far as the forest, by dead or by living action, raises or lowers the
temperature of the air within it, so far it creates upward or downward
currents in the atmosphere above it, and, consequently, a flow of air towards
or from itself. These air-streams have a certain, though doubtless a very
Page 220
small, influence on the force and direction of greater atmospheric
movements.] In the forest, the air is almost quiescent, and moves only as
local changes of temperature affect the specific gravity of its particles.
Hence there is often a dead calm in the woods when a furious blast is raging
in the open country at a few yards' distance. The denser the forest—as, for
example, where it consists of spike-leaved trees, or is thickly intermixed
with them—the more obvious is its effect, and no one can have passed from
the field to the wood in cold, windy weather, without having remarked it.
[Footnote: As a familiar illustration of the influence of the forest in
checking the movement of winds, I may mention the well-known fact, that
the sensible cold is never extreme in thick woods, where the motion of the
air is little felt. The lumbermen in Canada and the Northern United States
labor in the woods, without inconvenience, when the mercury stands many
degrees below the zero of Fahrenheit, while in the open grounds, with only
a moderate breeze, the same temperature is almost insupportable. The
engineers and firemen of locomotives, employed on railways running
through forests of any considerable extent, observe that, in very cold
weather, it is much easier to keep up the steam while the engine is passing
through the woods than in the open ground. As soon as the train emerges
from the shelter of the trees the steam-gauge falls, and the stoker is obliged
to throw in a liberal supply of fuel to bring it up again.
Another less frequently noticed fact, due, no doubt, in a great measure to
the immobility of the air, is, that sounds are transmitted to incredible
distances in the unbroken forest. Many instances of this have fallen under
my own observation, and others, yet more striking, have been related to me
by credible and competent witnesses familiar with a more primitive
condition of the Anglo-American world. An acute observer of natural
phenomena, whose childhood and youth were spent in the interior of one of
the newer New England States, has often told me that when he established
his home in the forest, he always distinctly heard, in still weather, the plash
movements.] In the forest, the air is almost quiescent, and moves only as
local changes of temperature affect the specific gravity of its particles.
Hence there is often a dead calm in the woods when a furious blast is raging
in the open country at a few yards' distance. The denser the forest—as, for
example, where it consists of spike-leaved trees, or is thickly intermixed
with them—the more obvious is its effect, and no one can have passed from
the field to the wood in cold, windy weather, without having remarked it.
[Footnote: As a familiar illustration of the influence of the forest in
checking the movement of winds, I may mention the well-known fact, that
the sensible cold is never extreme in thick woods, where the motion of the
air is little felt. The lumbermen in Canada and the Northern United States
labor in the woods, without inconvenience, when the mercury stands many
degrees below the zero of Fahrenheit, while in the open grounds, with only
a moderate breeze, the same temperature is almost insupportable. The
engineers and firemen of locomotives, employed on railways running
through forests of any considerable extent, observe that, in very cold
weather, it is much easier to keep up the steam while the engine is passing
through the woods than in the open ground. As soon as the train emerges
from the shelter of the trees the steam-gauge falls, and the stoker is obliged
to throw in a liberal supply of fuel to bring it up again.
Another less frequently noticed fact, due, no doubt, in a great measure to
the immobility of the air, is, that sounds are transmitted to incredible
distances in the unbroken forest. Many instances of this have fallen under
my own observation, and others, yet more striking, have been related to me
by credible and competent witnesses familiar with a more primitive
condition of the Anglo-American world. An acute observer of natural
phenomena, whose childhood and youth were spent in the interior of one of
the newer New England States, has often told me that when he established
his home in the forest, he always distinctly heard, in still weather, the plash
Page 221
of horses' feet, when they forded a small brook nearly seven-eighths of a
mile from his house, though a portion of the wood that intervened consisted
of a ridge seventy or eighty feet higher than either the house or the ford.
I have no doubt that, in such cases, the stillness of the air is the most
important element in the extraordinary transmissibilty of sound; but it must
be admitted that the absence of the multiplied, and confused noises, which
accompany human industry in countries thickly peopled by man,
contributes to the same result. We become, by habit, almost insensible to the
familiar and never-resting voices of civilization in cities and towns; but the
indistinguishable drone, which sometimes escapes even the ear of him who
listens for it, deadens and often quite obstructs the transmission of sounds
which would otherwise be clearly audible. An observer, who wishes to
appreciate that hum of civic life which he cannot analyze, will find an
excellent opportunity by placing himself on the hill of Capo di Monte at
Naples, in the line of prolongation of the street called Spaccanapoli.
It is probably to the stillness of which I have spoken that we are to
ascribe the transmission of sound to great distances at sea in calm weather.
In June, 1853, I and my family were passengers on board a ship-of-war
bound up the Aegean. On the evening of the 27th of that month, as we were
discussing, at the tea-table, some observations of Humboldt on this subject,
the captain of the ship told us that he had once heard a single gun at sea at
the distance of ninety nautical miles. The next morning, though a light
breeze had sprung up from the north, the sea was of glassy smoothness
when we went on deck. As we came up, an officer told us that he had heard
a gun at sunrise, and the conversation of the previous evening suggested the
inquiry whether it could have been fired from the combined French and
English fleet then lying at Beshika Bay. Upon examination of our position
we were found to have been, at sunrise, ninety sea miles from that point. We
continued beating up northwards, and between sunrise and twelve o'clock
mile from his house, though a portion of the wood that intervened consisted
of a ridge seventy or eighty feet higher than either the house or the ford.
I have no doubt that, in such cases, the stillness of the air is the most
important element in the extraordinary transmissibilty of sound; but it must
be admitted that the absence of the multiplied, and confused noises, which
accompany human industry in countries thickly peopled by man,
contributes to the same result. We become, by habit, almost insensible to the
familiar and never-resting voices of civilization in cities and towns; but the
indistinguishable drone, which sometimes escapes even the ear of him who
listens for it, deadens and often quite obstructs the transmission of sounds
which would otherwise be clearly audible. An observer, who wishes to
appreciate that hum of civic life which he cannot analyze, will find an
excellent opportunity by placing himself on the hill of Capo di Monte at
Naples, in the line of prolongation of the street called Spaccanapoli.
It is probably to the stillness of which I have spoken that we are to
ascribe the transmission of sound to great distances at sea in calm weather.
In June, 1853, I and my family were passengers on board a ship-of-war
bound up the Aegean. On the evening of the 27th of that month, as we were
discussing, at the tea-table, some observations of Humboldt on this subject,
the captain of the ship told us that he had once heard a single gun at sea at
the distance of ninety nautical miles. The next morning, though a light
breeze had sprung up from the north, the sea was of glassy smoothness
when we went on deck. As we came up, an officer told us that he had heard
a gun at sunrise, and the conversation of the previous evening suggested the
inquiry whether it could have been fired from the combined French and
English fleet then lying at Beshika Bay. Upon examination of our position
we were found to have been, at sunrise, ninety sea miles from that point. We
continued beating up northwards, and between sunrise and twelve o'clock
Page 222
meridian of the 28th, we had made twelve miles northing, reducing our
distance from Beshika Bay to seventy-eight sea miles. At noon we heard
several guns so distinctly that we were able to count the number. On the
29th we came up with the fleet, and learned from an officer who came on
board that a royal salute had been fired at noon on the 28th, in honor of the
day as the anniversary of the Queen of England's coronation. The report at
sunrise was evidently the morning gun, those at noon the salute.
Such cases are rare, because the sea is seldom still, and the [word in
Greek] rarely silent, over so great a space as ninety or even seventy-eight
nautical miles. I apply the epithet silent to [word in Greek] advisedly. I am
convinced that Aeschylus meant the audible laugh of the waves, which is
indeed of COUNTLESS multiplicity, not the visible smile of the sea, which,
belonging to the great expanse as one impersonation, is single, though, like
the human smile, made up of the play of many features.] The action of the
forest, considered merely as a mechanical shelter to grounds lying to the
leeward of it, might seem to be an influence of too restricted a character to
deserve much notice; but many facts concur to allow that it is a most
important element in local climate.
It is evident that the effect of the forest, as a mechanical impediment to
the passage of the wind, would extend to a very considerable distance above
its own height, and hence protect while standing, or lay open when felled, a
much larger surface than might at first thought be supposed. The
atmosphere, movable as are its particles, and light and elastic as are its
masses, is nevertheless held together as a continuous whole by the
gravitation of its atoms and their consequent pressure on each other, if not
by attraction between them, and, therefore, an obstruction which
mechanically impedes the movement of a given stratum of air will retard
the passage of the strata above and below it. To this effect may often be
added that of an ascending current from the forest itself, which must always
distance from Beshika Bay to seventy-eight sea miles. At noon we heard
several guns so distinctly that we were able to count the number. On the
29th we came up with the fleet, and learned from an officer who came on
board that a royal salute had been fired at noon on the 28th, in honor of the
day as the anniversary of the Queen of England's coronation. The report at
sunrise was evidently the morning gun, those at noon the salute.
Such cases are rare, because the sea is seldom still, and the [word in
Greek] rarely silent, over so great a space as ninety or even seventy-eight
nautical miles. I apply the epithet silent to [word in Greek] advisedly. I am
convinced that Aeschylus meant the audible laugh of the waves, which is
indeed of COUNTLESS multiplicity, not the visible smile of the sea, which,
belonging to the great expanse as one impersonation, is single, though, like
the human smile, made up of the play of many features.] The action of the
forest, considered merely as a mechanical shelter to grounds lying to the
leeward of it, might seem to be an influence of too restricted a character to
deserve much notice; but many facts concur to allow that it is a most
important element in local climate.
It is evident that the effect of the forest, as a mechanical impediment to
the passage of the wind, would extend to a very considerable distance above
its own height, and hence protect while standing, or lay open when felled, a
much larger surface than might at first thought be supposed. The
atmosphere, movable as are its particles, and light and elastic as are its
masses, is nevertheless held together as a continuous whole by the
gravitation of its atoms and their consequent pressure on each other, if not
by attraction between them, and, therefore, an obstruction which
mechanically impedes the movement of a given stratum of air will retard
the passage of the strata above and below it. To this effect may often be
added that of an ascending current from the forest itself, which must always
Page 223
exist when the atmosphere within the wood is warmer than the stratum of
air above it, and must be of almost constant occurrence in the case of cold
winds, from whatever quarter, because the still air in the forest is slow in
taking up the temperature of the moving columns and currents around and
above it. Experience, in fact, has shown that mere rows of trees, and even
much lower obstructions, are of essential service in defending vegetation
against the action of the wind. Hardy proposes planting, in Algeria, belts of
trees at the distance of one hundred metres from each other, as a shelter
which experience had proved to be useful in France. [Footnote: Becquerel,
Des Climats, etc., p. 179.] "In the valley of the Rhone," says Becquerel, "a
simple hedge, two metres in height, is a sufficient protection for a distance
of twenty-two metres." [Footnote: Ibid., p. 116. Becquerel's views have
been amply confirmed by recent extensive experiments on the bleak, stony,
and desolate plain of the Cran in the Department of the Bouches-du-Rhone,
which had remained a naked waste from the earliest ages of history. Belts of
trees prove a secure protection even against the furious and chilly blasts of
the Mistral, and in this shelter plantations of fruit-trees and vegetables,
fertilized by the waters and the slime of the Durance, which are conducted
and distributed over the Cran, thrive with the greatest luxuriance. [Footnote:
Surrell, Etude sur les Torrents, 2d edition, 1872, ii, p. 85.] The mechanical
shelter acts, no doubt, chiefly as a defence against the mechanical force of
the wind, but its uses are by no means limited to this effect. If the current of
air which it resists moves horizontally, it would prevent the access of cold
or parching blasts to the ground for a great distance; and did the wind even
descend at a large angle with the surface, still a considerable extent of
ground would be protected by a forest to the windward of it.
In the report of a committee appointed in 1836 to examine an article of
the forest code of France, Arago observes; "If a curtain of forest on the
coasts of Normandy and of Brittany were destroyed, these two provinces
would become accessible to the winds from the west, to the mild breezes of
air above it, and must be of almost constant occurrence in the case of cold
winds, from whatever quarter, because the still air in the forest is slow in
taking up the temperature of the moving columns and currents around and
above it. Experience, in fact, has shown that mere rows of trees, and even
much lower obstructions, are of essential service in defending vegetation
against the action of the wind. Hardy proposes planting, in Algeria, belts of
trees at the distance of one hundred metres from each other, as a shelter
which experience had proved to be useful in France. [Footnote: Becquerel,
Des Climats, etc., p. 179.] "In the valley of the Rhone," says Becquerel, "a
simple hedge, two metres in height, is a sufficient protection for a distance
of twenty-two metres." [Footnote: Ibid., p. 116. Becquerel's views have
been amply confirmed by recent extensive experiments on the bleak, stony,
and desolate plain of the Cran in the Department of the Bouches-du-Rhone,
which had remained a naked waste from the earliest ages of history. Belts of
trees prove a secure protection even against the furious and chilly blasts of
the Mistral, and in this shelter plantations of fruit-trees and vegetables,
fertilized by the waters and the slime of the Durance, which are conducted
and distributed over the Cran, thrive with the greatest luxuriance. [Footnote:
Surrell, Etude sur les Torrents, 2d edition, 1872, ii, p. 85.] The mechanical
shelter acts, no doubt, chiefly as a defence against the mechanical force of
the wind, but its uses are by no means limited to this effect. If the current of
air which it resists moves horizontally, it would prevent the access of cold
or parching blasts to the ground for a great distance; and did the wind even
descend at a large angle with the surface, still a considerable extent of
ground would be protected by a forest to the windward of it.
In the report of a committee appointed in 1836 to examine an article of
the forest code of France, Arago observes; "If a curtain of forest on the
coasts of Normandy and of Brittany were destroyed, these two provinces
would become accessible to the winds from the west, to the mild breezes of
Page 224
the sea. Hence a decrease of the cold of winter. If a similar forest were to be
cleared on the eastern border of France, the glacial east wind would prevail
with greater strength, and the winters would become more severe. Thus the
removal of a belt of wood would produce opposite effects in the two
regions." [Footnote: Becquerel, Des Climats, etc., Discours Prelim., vi.]
This opinion receives confirmation from an observation of Dr. Dwight,
who remarks, in reference to the woods of New England: "Another effect of
removing the forest will be the free passage of the winds, and among them
of the southern winds, over the surface. This, I think, has been an increasing
fact within my own remembrance. As the cultivation of the country has
extended further to the north, the winds from the south have reached
distances more remote from the ocean, and imparted their warmth
frequently, and in such degrees as, forty years since, were in the same
places very little known. This fact, also, contributes to lengthen the summer
and to shorten the winter half of the year." [Footnote: Travels, i., p. 61.]
It is thought in Italy that the clearing of the Apennines has very
materially affected the climate of the valley of the Po. It is asserted in Le
Alpi che cingono l'Italia that: "In consequence of the felling of the woods
on the Apennines, the sirocco prevails greatly on the right bank of the Po, in
the Parmesan territory, and in a part of Lombardy; it injures the harvests
and the vineyards, and sometimes ruins the crops of the season. To the same
cause many ascribe the meteorological changes in the precincts of Modena
and of Reggio. In the communes of these districts, where formerly straw
roofs resisted the force of the winds, tiles are now hardly sufficient; in
others, where tiles answered for roofs, large slabs of stone are now
ineffectual; and in many neighboring communes the grapes and the grain
are swept off by the blasts of the south and south-west winds."
cleared on the eastern border of France, the glacial east wind would prevail
with greater strength, and the winters would become more severe. Thus the
removal of a belt of wood would produce opposite effects in the two
regions." [Footnote: Becquerel, Des Climats, etc., Discours Prelim., vi.]
This opinion receives confirmation from an observation of Dr. Dwight,
who remarks, in reference to the woods of New England: "Another effect of
removing the forest will be the free passage of the winds, and among them
of the southern winds, over the surface. This, I think, has been an increasing
fact within my own remembrance. As the cultivation of the country has
extended further to the north, the winds from the south have reached
distances more remote from the ocean, and imparted their warmth
frequently, and in such degrees as, forty years since, were in the same
places very little known. This fact, also, contributes to lengthen the summer
and to shorten the winter half of the year." [Footnote: Travels, i., p. 61.]
It is thought in Italy that the clearing of the Apennines has very
materially affected the climate of the valley of the Po. It is asserted in Le
Alpi che cingono l'Italia that: "In consequence of the felling of the woods
on the Apennines, the sirocco prevails greatly on the right bank of the Po, in
the Parmesan territory, and in a part of Lombardy; it injures the harvests
and the vineyards, and sometimes ruins the crops of the season. To the same
cause many ascribe the meteorological changes in the precincts of Modena
and of Reggio. In the communes of these districts, where formerly straw
roofs resisted the force of the winds, tiles are now hardly sufficient; in
others, where tiles answered for roofs, large slabs of stone are now
ineffectual; and in many neighboring communes the grapes and the grain
are swept off by the blasts of the south and south-west winds."
Page 225
According to the same authority, the pinery of Porto, near Ravenna—
which is twenty miles long, and is one of the oldest pine woods in Italy—
having been replanted with resinous trees after it was unfortunately cut, has
relieved the city from the sirocco to which it had become exposed, and in a
great degree restored its ancient climate. [Footnote: Le Alpi che cingono
l'Italia, pp. 370, 371.]
The felling of the woods on the Atlantic coast of Jutland has exposed the
soil not only to drifting sands, but to sharp sea-winds, that have exerted a
sensible deteriorating effect on the climate of that peninsula, which has no
mountains to serve at once as a barrier to the force of the winds, and as a
storehouse of moisture received by precipitation or condensed from
atmospheric vapors. [Footnote: Bergsoe, Reventlovs Virksomhed, ii., p.
125.
The following well-attested instance of a local change of climate is
probably to be referred to the influence of the forest as a shelter against cold
winds. To supply the extraordinary demand for Italian iron occasioned by
the exclusion of English iron in the time of Napoleon I., the furnaces of the
valleys of Bergamo were stimulated to great activity. "The ordinary
production of charcoal not sufficing to feed the furnaces and the forges, the
woods were felled, the copses cut before their time, and the whole economy
of the forest was deranged. At Piazzatorre there was such a devastation of
the woods, and consequently such an increased severity of climate, that
maize no longer ripened. An association, formed for the purpose, effected
the restoration of the forest, and maize flourishes again in the fields of
Piazzatorre." —Report by G. Rosa, in Il Politecnico, Dicembre, 1861, p.
614.
Similar ameliorations have been produced by plantations in Belgium. In
an interesting series of articles by Bande, entitled, "Les Cotes de la
which is twenty miles long, and is one of the oldest pine woods in Italy—
having been replanted with resinous trees after it was unfortunately cut, has
relieved the city from the sirocco to which it had become exposed, and in a
great degree restored its ancient climate. [Footnote: Le Alpi che cingono
l'Italia, pp. 370, 371.]
The felling of the woods on the Atlantic coast of Jutland has exposed the
soil not only to drifting sands, but to sharp sea-winds, that have exerted a
sensible deteriorating effect on the climate of that peninsula, which has no
mountains to serve at once as a barrier to the force of the winds, and as a
storehouse of moisture received by precipitation or condensed from
atmospheric vapors. [Footnote: Bergsoe, Reventlovs Virksomhed, ii., p.
125.
The following well-attested instance of a local change of climate is
probably to be referred to the influence of the forest as a shelter against cold
winds. To supply the extraordinary demand for Italian iron occasioned by
the exclusion of English iron in the time of Napoleon I., the furnaces of the
valleys of Bergamo were stimulated to great activity. "The ordinary
production of charcoal not sufficing to feed the furnaces and the forges, the
woods were felled, the copses cut before their time, and the whole economy
of the forest was deranged. At Piazzatorre there was such a devastation of
the woods, and consequently such an increased severity of climate, that
maize no longer ripened. An association, formed for the purpose, effected
the restoration of the forest, and maize flourishes again in the fields of
Piazzatorre." —Report by G. Rosa, in Il Politecnico, Dicembre, 1861, p.
614.
Similar ameliorations have been produced by plantations in Belgium. In
an interesting series of articles by Bande, entitled, "Les Cotes de la
Page 226
Manche," in the Revue des Deux Mondes, I find this statement: "A
spectator, placed on the famous bell-tower of the cathedral of Antwerp, saw,
not long since, on the opposite side of the Schelde, only a vast desert plain;
now he sees a forest, the limits of which are confounded with the horizon.
Let him enter within its shade. The supposed forest is but a system of
regular rows of trees, the oldest of which is not forty years of age. These
plantations have ameliorated the climate which had doomed to sterility the
soil where they are planted. While the tempest is violently agitating their
tops, the air a little below is still, and sands far more barren than the plateau
of La Hague have been transformed, under their protection, into fertile
fields."—Revue des Deux Mondes, January, 1859, p. 277.] The local
retardation of spring, so much complained of in Italy, France, and
Switzerland, and the increased frequency of late frosts at that season, appear
to be ascribable to the admission of cold blasts to the surface, by the felling
of the forests which formerly both screened it as by a wall, and
communicated the warmth of their soil to the air and earth to the leeward.
Caimi states that since the cutting down of the woods of the Apennines,
the cold winds destroy or stunt the vegetation, and that, in consequence of
"the usurpation of winter on the domain of spring," the district of Mugello
has lost all its mulberries, except the few which find in the lee of buildings
a protection like that once furnished by the forest. [Footnote: Cenni sulla
Importanza e Coltura dei Boschi, p. 31.]
The department of Ardeche, which now contains not a single
considerable wood, has experienced within thirty years a climatic
disturbance, of which the late frosts, formerly unknown in the country, are
one of the most melancholy effects. Similar results have been observed in
the plain of Alsace, in consequence of the denudation of several of the
crests of the Vosges. [Footnote: Clave, Etudes, p. 44.] [Footnote It has been
observed in Sweden that the spring, in many districts where the forests have
spectator, placed on the famous bell-tower of the cathedral of Antwerp, saw,
not long since, on the opposite side of the Schelde, only a vast desert plain;
now he sees a forest, the limits of which are confounded with the horizon.
Let him enter within its shade. The supposed forest is but a system of
regular rows of trees, the oldest of which is not forty years of age. These
plantations have ameliorated the climate which had doomed to sterility the
soil where they are planted. While the tempest is violently agitating their
tops, the air a little below is still, and sands far more barren than the plateau
of La Hague have been transformed, under their protection, into fertile
fields."—Revue des Deux Mondes, January, 1859, p. 277.] The local
retardation of spring, so much complained of in Italy, France, and
Switzerland, and the increased frequency of late frosts at that season, appear
to be ascribable to the admission of cold blasts to the surface, by the felling
of the forests which formerly both screened it as by a wall, and
communicated the warmth of their soil to the air and earth to the leeward.
Caimi states that since the cutting down of the woods of the Apennines,
the cold winds destroy or stunt the vegetation, and that, in consequence of
"the usurpation of winter on the domain of spring," the district of Mugello
has lost all its mulberries, except the few which find in the lee of buildings
a protection like that once furnished by the forest. [Footnote: Cenni sulla
Importanza e Coltura dei Boschi, p. 31.]
The department of Ardeche, which now contains not a single
considerable wood, has experienced within thirty years a climatic
disturbance, of which the late frosts, formerly unknown in the country, are
one of the most melancholy effects. Similar results have been observed in
the plain of Alsace, in consequence of the denudation of several of the
crests of the Vosges. [Footnote: Clave, Etudes, p. 44.] [Footnote It has been
observed in Sweden that the spring, in many districts where the forests have
Page 227
been cleared off, now comes on a fortnight later than in the last century.—
Asbjornsen, Om Skovene i norge, p. 101.] Dussard, as quoted by Ribbe,
[Footnote: La Provence au point de vue des Torrents et des Inondations, p.
10.
Dussard is doubtless historically inaccurate in making the origin of the
mistral so late as the time of Augustus. Diodorus Siculus, who was a
contemporary of Julius Caesar, describes the north-west winds in Gaul as
violent enough to hurl along stones as large as the fist with clouds of sand
and gravel, to strip travellers of their arms and clothing, and to throw
mounted men from their horses. Bibliotheca Historica, lib. v., c. xxvi.
Diodorus, it is true, is speaking of the climate of Gaul in general, but his
description can hardly refer to anything but the mistral of South-eastern
France.] maintains that even the MISTRAL, or north-west wind, whose
chilling blasts are so fatal to tender vegetation in the spring, "is the child of
man, the result of his devastations." "Under the reign of Augustus,"
continues he, "the forests which protected the Cevennes were felled, or
destroyed by fire, in mass. A vast country, before covered with impenetrable
woods—powerful obstacles to the movement and even to the formation of
hurricanes—was suddenly denuded, swept bare, stripped, and soon after, a
scourge hitherto unknown, struck terror over the land from Avignon to the
Bouches-du-Rhone, thence to Marseilles, and then extended its ravages,
diminished indeed by a long career which had partially exhausted its force,
over the whole maritime frontier. The people thought this wind a curse sent
of God. They raised altars to it and offered sacrifices to appease its rage." It
seems, however, that this plague was less destructive than at present, until
the close of the sixteenth century, when further clearings had removed most
of the remaining barriers to its course. Up to that time, the north-west wind
appears not to have attained to the maximum of specific effect which now
characterizes it as a local phenomenon. Extensive districts, from which the
rigor of the seasons has now banished valuable crops, were not then
Asbjornsen, Om Skovene i norge, p. 101.] Dussard, as quoted by Ribbe,
[Footnote: La Provence au point de vue des Torrents et des Inondations, p.
10.
Dussard is doubtless historically inaccurate in making the origin of the
mistral so late as the time of Augustus. Diodorus Siculus, who was a
contemporary of Julius Caesar, describes the north-west winds in Gaul as
violent enough to hurl along stones as large as the fist with clouds of sand
and gravel, to strip travellers of their arms and clothing, and to throw
mounted men from their horses. Bibliotheca Historica, lib. v., c. xxvi.
Diodorus, it is true, is speaking of the climate of Gaul in general, but his
description can hardly refer to anything but the mistral of South-eastern
France.] maintains that even the MISTRAL, or north-west wind, whose
chilling blasts are so fatal to tender vegetation in the spring, "is the child of
man, the result of his devastations." "Under the reign of Augustus,"
continues he, "the forests which protected the Cevennes were felled, or
destroyed by fire, in mass. A vast country, before covered with impenetrable
woods—powerful obstacles to the movement and even to the formation of
hurricanes—was suddenly denuded, swept bare, stripped, and soon after, a
scourge hitherto unknown, struck terror over the land from Avignon to the
Bouches-du-Rhone, thence to Marseilles, and then extended its ravages,
diminished indeed by a long career which had partially exhausted its force,
over the whole maritime frontier. The people thought this wind a curse sent
of God. They raised altars to it and offered sacrifices to appease its rage." It
seems, however, that this plague was less destructive than at present, until
the close of the sixteenth century, when further clearings had removed most
of the remaining barriers to its course. Up to that time, the north-west wind
appears not to have attained to the maximum of specific effect which now
characterizes it as a local phenomenon. Extensive districts, from which the
rigor of the seasons has now banished valuable crops, were not then
Page 228
exposed to the loss of their harvests by tempests, cold, or drought. The
deterioration was rapid in its progress. Under the Consulate, the clearings
had exerted so injurious an effect upon the climate, that the cultivation of
the olive had retreated several leagues, and since the winters and springs of
1820 and 1836, this branch of rural industry has been abandoned in a great
number of localities where it was advantageously pursued before. The
orange now flourishes only at a few sheltered points of the coast, and it is
threatened even at Hyeres, where the clearing of the hills near the town has
proved very prejudicial to this valuable tree.
Marchand informs us that, since the felling of the woods, late spring
frosts are more frequent in many localities north of the Alps; that fruit-trees
thrive no longer, and that it is difficult even to raise young fruit-trees.
[Footnote: Ueber die Entwaldung der Gebirge, p. 28. Interesting facts and
observations on this point will be found in the valuable Report on the
Effects of the Destruction of the Forests in Wisconsin, by LAPHAM and
others, pp. 6, 18, 20.]
Influence of the Forest, considered as Inorganic Matter, on Temperature.
The evaporation of fluids, and the condensation and expansion of vapors
and gases, are attended with changes of temperature; and the quantity of
moisture which the air is capable of containing, and of course, other things
being equal, the evaporation, rise and fall with the thermometer. The
hygroscopical and the thermoscopical conditions of the atmosphere are,
therefore, inseparably connected as reciprocally dependent quantities, and
neither can be fully discussed without taking notice of the other. The leaves
of living trees exhale enormous quantities of gas and of aqueous vapor, and
they largely absorb gases, and, under certain conditions, probably also
water. Hence they affect more or less powerfully the temperature as well as
the humidity of the air. But the forest, regarded purely as inorganic matter,
and without reference to its living processes of absorption and exhalation of
deterioration was rapid in its progress. Under the Consulate, the clearings
had exerted so injurious an effect upon the climate, that the cultivation of
the olive had retreated several leagues, and since the winters and springs of
1820 and 1836, this branch of rural industry has been abandoned in a great
number of localities where it was advantageously pursued before. The
orange now flourishes only at a few sheltered points of the coast, and it is
threatened even at Hyeres, where the clearing of the hills near the town has
proved very prejudicial to this valuable tree.
Marchand informs us that, since the felling of the woods, late spring
frosts are more frequent in many localities north of the Alps; that fruit-trees
thrive no longer, and that it is difficult even to raise young fruit-trees.
[Footnote: Ueber die Entwaldung der Gebirge, p. 28. Interesting facts and
observations on this point will be found in the valuable Report on the
Effects of the Destruction of the Forests in Wisconsin, by LAPHAM and
others, pp. 6, 18, 20.]
Influence of the Forest, considered as Inorganic Matter, on Temperature.
The evaporation of fluids, and the condensation and expansion of vapors
and gases, are attended with changes of temperature; and the quantity of
moisture which the air is capable of containing, and of course, other things
being equal, the evaporation, rise and fall with the thermometer. The
hygroscopical and the thermoscopical conditions of the atmosphere are,
therefore, inseparably connected as reciprocally dependent quantities, and
neither can be fully discussed without taking notice of the other. The leaves
of living trees exhale enormous quantities of gas and of aqueous vapor, and
they largely absorb gases, and, under certain conditions, probably also
water. Hence they affect more or less powerfully the temperature as well as
the humidity of the air. But the forest, regarded purely as inorganic matter,
and without reference to its living processes of absorption and exhalation of
Page 229
gases and of water, has, as an absorbent, a radiator and a conductor of heat,
and as a mere covering of the ground, an influence on the temperature of
the air and the earth, which may be considered by itself.
Absorbing and Emitting Surface.
A given area of ground, as estimated by the every-day rule of
measurement in yards or acres, presents always the same apparent quantity
of absorbing, radiating, and reflecting surface; but the real extent of that
surface is very variable, depending, as it does, upon its configuration, and
the bulk and form of the adventitious objects it bears upon it; and, besides,
the true superficies remaining the same, its power of absorption, radiation,
reflection, and conduction of heat will be much affected by its consistence,
its greater or less humidity, and its color, as well as by its inclination of
plane and exposure. An acre of clay, rolled hard and smooth, would have
great reflecting power, but its radiation would be much increased by
breaking it up into clods, because the actually exposed surface would be
greater, though the outline of the field remained the same. The inequalities,
natural or artificial, which always occur in the surface of ordinary earth,
affect in the same way its quantity of superficies acting upon the
temperature of the atmosphere, and acted on by it, though the amount of
this action and reaction is not susceptible of measurement.
Analogous effects are produced by other objects, of whatever form or
character, standing or lying upon the earth, and no solid can be placed upon
a flat piece of ground, without itself exposing a greater surface than it
covers. This applies, of course, to forest trees and their leaves, and indeed to
all vegetables, as well as to other prominent bodies. If we suppose forty
trees to be planted on an acre, one being situated in the centre of every
square of two rods the side, and to grow until their branches and leaves
everywhere meet, it is evident that, when in full foliage, the trunks,
and as a mere covering of the ground, an influence on the temperature of
the air and the earth, which may be considered by itself.
Absorbing and Emitting Surface.
A given area of ground, as estimated by the every-day rule of
measurement in yards or acres, presents always the same apparent quantity
of absorbing, radiating, and reflecting surface; but the real extent of that
surface is very variable, depending, as it does, upon its configuration, and
the bulk and form of the adventitious objects it bears upon it; and, besides,
the true superficies remaining the same, its power of absorption, radiation,
reflection, and conduction of heat will be much affected by its consistence,
its greater or less humidity, and its color, as well as by its inclination of
plane and exposure. An acre of clay, rolled hard and smooth, would have
great reflecting power, but its radiation would be much increased by
breaking it up into clods, because the actually exposed surface would be
greater, though the outline of the field remained the same. The inequalities,
natural or artificial, which always occur in the surface of ordinary earth,
affect in the same way its quantity of superficies acting upon the
temperature of the atmosphere, and acted on by it, though the amount of
this action and reaction is not susceptible of measurement.
Analogous effects are produced by other objects, of whatever form or
character, standing or lying upon the earth, and no solid can be placed upon
a flat piece of ground, without itself exposing a greater surface than it
covers. This applies, of course, to forest trees and their leaves, and indeed to
all vegetables, as well as to other prominent bodies. If we suppose forty
trees to be planted on an acre, one being situated in the centre of every
square of two rods the side, and to grow until their branches and leaves
everywhere meet, it is evident that, when in full foliage, the trunks,
Page 230
branches, and leaves would present an amount of thermoscopic surface
much greater than that of an acre of bare earth; and besides this, the fallen
leaves lying scattered on the ground, would somewhat augment the sum-
total. [Footnote: "The Washington elm at Cambridge—a tree of no
extraordinary size—was some years ago estimated to produce a crop of
seven millions of leaves, exposing a surface of two hundred thousand
square feet, or about five acres of foliage."—Gray, First Lessons in Botany
and Vegetable Physiology.] On the other hand, the growing leaves of trees
generally form a succession of stages, or, loosely speaking, layers,
corresponding to the annual growth of the branches, and more or less
overlying each other. This disposition of the foliage interferes with that free
communication between sun and sky above, and leaf-surface below, on
which the amount of radiation and absorption of light depends. From all
these considerations, it appears that though the effective thermoscopic
surface of a forest in full leaf does not exceed that of bare ground in the
same proportion as does its measured superficies, yet the actual quantity of
area capable of receiving and emitting heat must be greater in the former
than in the latter case. [Footnote: See, on this particular point, and on the
general influence of the forest on temperature, Humboldt, Ansichten der
Natur, i., 158.]
It must further be remembered that the form and texture of a given
surface are important elements in determining its thermoscopic character.
Leaves are porous, and admit air and light more or less freely into their
substance; they are generally smooth and even glazed on one surface; they
are usually covered on one or both sides with spicula, and they very
commonly present one or more acuminated points in their outline—all
circumstances which tend to augment their power of emitting heat by
reflection or radiation. Direct experiment on growing trees is very difficult,
nor is it in any case practicable to distinguish how far a reduction of
temperature produced by vegetation is due to radiation, and how far to
much greater than that of an acre of bare earth; and besides this, the fallen
leaves lying scattered on the ground, would somewhat augment the sum-
total. [Footnote: "The Washington elm at Cambridge—a tree of no
extraordinary size—was some years ago estimated to produce a crop of
seven millions of leaves, exposing a surface of two hundred thousand
square feet, or about five acres of foliage."—Gray, First Lessons in Botany
and Vegetable Physiology.] On the other hand, the growing leaves of trees
generally form a succession of stages, or, loosely speaking, layers,
corresponding to the annual growth of the branches, and more or less
overlying each other. This disposition of the foliage interferes with that free
communication between sun and sky above, and leaf-surface below, on
which the amount of radiation and absorption of light depends. From all
these considerations, it appears that though the effective thermoscopic
surface of a forest in full leaf does not exceed that of bare ground in the
same proportion as does its measured superficies, yet the actual quantity of
area capable of receiving and emitting heat must be greater in the former
than in the latter case. [Footnote: See, on this particular point, and on the
general influence of the forest on temperature, Humboldt, Ansichten der
Natur, i., 158.]
It must further be remembered that the form and texture of a given
surface are important elements in determining its thermoscopic character.
Leaves are porous, and admit air and light more or less freely into their
substance; they are generally smooth and even glazed on one surface; they
are usually covered on one or both sides with spicula, and they very
commonly present one or more acuminated points in their outline—all
circumstances which tend to augment their power of emitting heat by
reflection or radiation. Direct experiment on growing trees is very difficult,
nor is it in any case practicable to distinguish how far a reduction of
temperature produced by vegetation is due to radiation, and how far to
Page 231
exhalation of the gaseous and watery fluids of the plant; for both processes
usually go on together. But the frigorific effect of leafy structure is well
observed in the deposit of dew and the occurrence of hoarfrost on the
foliage of grasses and other small vegetables, and on other objects of
similar form and consistence, when the temperature of the air a few feet
above has not been brought down to the dew-point, still less to 32 degrees,
the degree of cold required to congeal dew to frost. [Footnote: The leaves
and twigs of plants may be reduced by radiation to a temperature lower than
that of the ambient atmosphere, and even be frozen when the air in contact
with them is above 32 degrees. Their temperature may be communicated to
the dew deposited on them and thus this dew be converted into frost when
globules of watery fluid floating in the atmosphere near them, in the
condition of fog or vapor, do not become congealed.
It has long been known that vegetables can be protected against frost by
diffusing smoke through the atmosphere above them. This method has been
lately practised in France on a large scale: vineyards of forty or fifty acres
have been protected by placing one or two rows of pots of burning coal-tar,
or of naphtha, along the north side of the vineyard, and thus keeping up a
cloud of smoke for two or three hours before and after sunrise. The expense
is said to be small, and probably it might be reduced by mixing some less
combustible substance, as earth, with the fluid, and thus checking its too
rapid burning.
The radiating and refrigerating power of objects by no means depends on
their form alone. Melloni cut sheets of metal into the shape of leaves and
grasses, and found that they produced little cooling effect, and were not
moistened under atmospheric conditions which determined a plentiful
deposit of dew on the leaves of vegetables.]
usually go on together. But the frigorific effect of leafy structure is well
observed in the deposit of dew and the occurrence of hoarfrost on the
foliage of grasses and other small vegetables, and on other objects of
similar form and consistence, when the temperature of the air a few feet
above has not been brought down to the dew-point, still less to 32 degrees,
the degree of cold required to congeal dew to frost. [Footnote: The leaves
and twigs of plants may be reduced by radiation to a temperature lower than
that of the ambient atmosphere, and even be frozen when the air in contact
with them is above 32 degrees. Their temperature may be communicated to
the dew deposited on them and thus this dew be converted into frost when
globules of watery fluid floating in the atmosphere near them, in the
condition of fog or vapor, do not become congealed.
It has long been known that vegetables can be protected against frost by
diffusing smoke through the atmosphere above them. This method has been
lately practised in France on a large scale: vineyards of forty or fifty acres
have been protected by placing one or two rows of pots of burning coal-tar,
or of naphtha, along the north side of the vineyard, and thus keeping up a
cloud of smoke for two or three hours before and after sunrise. The expense
is said to be small, and probably it might be reduced by mixing some less
combustible substance, as earth, with the fluid, and thus checking its too
rapid burning.
The radiating and refrigerating power of objects by no means depends on
their form alone. Melloni cut sheets of metal into the shape of leaves and
grasses, and found that they produced little cooling effect, and were not
moistened under atmospheric conditions which determined a plentiful
deposit of dew on the leaves of vegetables.]
Page 232
We are also to take into account the action of the forest as a conductor of
heat between the atmosphere and the earth. In the most important countries
of America and Europe, and especially in those which have suffered most
from the destruction of the woods, the superficial strata of the earth are
colder in winter, and warmer in summer, than those a few inches lower, and
their shifting temperature approximates to the atmospheric mean of the
respective seasons. The roots of large trees penetrate beneath the superficial
strata, and reach earth of a nearly constant temperature, corresponding to
the mean for the entire year. As conductors, they convey the heat of the
atmosphere to the earth when the earth is colder than the air, and transmit it
in the contrary direction when the temperature of the earth is higher than
that of the atmosphere. Of course, then, as conductors, they tend to equalize
the temperature of the earth and the air.
In countries where the questions I am considering have the greatest
practical importance, a very large proportion, if not a majority, of the trees
are of deciduous foliage, and their radiating as well as their shading surface
is very much greater in summer than in winter. In the latter season, they
little obstruct the reception of heat by the ground or the radiation from it;
whereas, in the former, they often interpose a complete canopy between the
ground and the sky, and materially interfere with both processes.
Dead Products of Trees.
Besides this various action of standing trees, considered as inorganic
matter, the forest exercises, by the annual moulting of its foliage, still
another influence on the temperature of the earth, and, consequently, of the
atmosphere which rests upon it. If we examine the constitution of the
superficial soil in a primitive or an old and undisturbed artificially planted
wood, we find, first, a deposit of undecayed leaves, twigs, and seeds, lying
in loose layers on the surface; then, more compact beds of the same
heat between the atmosphere and the earth. In the most important countries
of America and Europe, and especially in those which have suffered most
from the destruction of the woods, the superficial strata of the earth are
colder in winter, and warmer in summer, than those a few inches lower, and
their shifting temperature approximates to the atmospheric mean of the
respective seasons. The roots of large trees penetrate beneath the superficial
strata, and reach earth of a nearly constant temperature, corresponding to
the mean for the entire year. As conductors, they convey the heat of the
atmosphere to the earth when the earth is colder than the air, and transmit it
in the contrary direction when the temperature of the earth is higher than
that of the atmosphere. Of course, then, as conductors, they tend to equalize
the temperature of the earth and the air.
In countries where the questions I am considering have the greatest
practical importance, a very large proportion, if not a majority, of the trees
are of deciduous foliage, and their radiating as well as their shading surface
is very much greater in summer than in winter. In the latter season, they
little obstruct the reception of heat by the ground or the radiation from it;
whereas, in the former, they often interpose a complete canopy between the
ground and the sky, and materially interfere with both processes.
Dead Products of Trees.
Besides this various action of standing trees, considered as inorganic
matter, the forest exercises, by the annual moulting of its foliage, still
another influence on the temperature of the earth, and, consequently, of the
atmosphere which rests upon it. If we examine the constitution of the
superficial soil in a primitive or an old and undisturbed artificially planted
wood, we find, first, a deposit of undecayed leaves, twigs, and seeds, lying
in loose layers on the surface; then, more compact beds of the same
Page 233
materials in incipient, and, as we descend, more and more advanced, stages
of decomposition; then, a mass of black mould, in which traces of organic
structure are hardly discoverable except by microscopic examination; then,
a stratum of mineral soil, more or less mixed with vegetable matter carried
down into it by water, or resulting from the decay of roots; and, finally, the
inorganic earth or rock itself. Without this deposit of the dead products of
trees, this latter would be the superficial stratum, and as its powers of
absorption, radiation, and conduction of heat would differ essentially from
those of the layers with which it has been covered by the droppings of the
forest, it would act upon the temperature of the atmosphere, and be acted on
by it, in a very different way from the leaves and mould which rest upon it.
Dead leaves, still entire, or partially decayed, are very indifferent
conductors of light, and, therefore, though they diminish the warming
influence of the summer sun on the soil below them, they, on the other
hand, prevent the escape of heat from that soil in winter, and, consequently,
in cold climates, even when the ground is not covered by a protecting
mantle of snow, the earth does not freeze to as great a depth in the wood as
in the open field.
Specific Heat.
Trees, considered as organisms, produce in themselves, or in the air, a
certain amount of heat, by absorbing and condensing atmospheric gases,
and they exert an opposite influence by absorbing water and exhaling it in
the form of vapor; but there is still another mode by which their living
processes may warm the air around them, independently of the
thermometric effects of condensation and evaporation. The vital heat of a
dozen persons raises the temperature of a room. If trees possess a specific
temperature of their own, an organic power of generating heat like that with
which the warm-blooded animals are gifted, though by a different process, a
of decomposition; then, a mass of black mould, in which traces of organic
structure are hardly discoverable except by microscopic examination; then,
a stratum of mineral soil, more or less mixed with vegetable matter carried
down into it by water, or resulting from the decay of roots; and, finally, the
inorganic earth or rock itself. Without this deposit of the dead products of
trees, this latter would be the superficial stratum, and as its powers of
absorption, radiation, and conduction of heat would differ essentially from
those of the layers with which it has been covered by the droppings of the
forest, it would act upon the temperature of the atmosphere, and be acted on
by it, in a very different way from the leaves and mould which rest upon it.
Dead leaves, still entire, or partially decayed, are very indifferent
conductors of light, and, therefore, though they diminish the warming
influence of the summer sun on the soil below them, they, on the other
hand, prevent the escape of heat from that soil in winter, and, consequently,
in cold climates, even when the ground is not covered by a protecting
mantle of snow, the earth does not freeze to as great a depth in the wood as
in the open field.
Specific Heat.
Trees, considered as organisms, produce in themselves, or in the air, a
certain amount of heat, by absorbing and condensing atmospheric gases,
and they exert an opposite influence by absorbing water and exhaling it in
the form of vapor; but there is still another mode by which their living
processes may warm the air around them, independently of the
thermometric effects of condensation and evaporation. The vital heat of a
dozen persons raises the temperature of a room. If trees possess a specific
temperature of their own, an organic power of generating heat like that with
which the warm-blooded animals are gifted, though by a different process, a
Page 234
certain amount of weight is to be ascribed to this element in estimating the
action of the forest upon atmospheric temperature.
Boussingault remarks: "In many flowers there has been observed a very
considerable evolution of heat, at the approach of fecundation. In certain
arums the temperature rises to 40 degrees or 50 degrees Cent. [= 104
degrees or 122 degrees Fahr.] It is very probable that this phenomenon in
general, and varies only in the intensity which it is manifested." [Footnote:
Economie Rurale, i., p. 22.]
If we suppose the fecundation of the flowers of forest trees to be attended
with a tenth only of this calorific power, they could not fail to exert an
important influence on the warmth of the atmospheric strata in contact with
them.
Experiments by Meguscher, in Lombardy, led that observer to conclude
"that the wood of a living tree maintains a temperature of + 12 degrees or
18 degrees Cent. [= 54 degrees, 56 degrees Fahr.] when the temperature of
the air stands at 3 degrees, 7 degrees, and 8 degrees [= 37 degrees, 46
degrees, 47 degrees F.] above zero, and that the internal warmth of the tree
does not rise and fall in proportion to that of the atmosphere. So long as the
latter is below 18 degrees [= 67 degrees Fahr.], that of the tree is always the
highest; but if the temperature of the air rises to 18 degrees, that of the
vegetable growth is the lowest. Since then, trees maintain at all seasons a
constant mean temperature of 12 degrees [= 54 degrees Fahr.], it is easy to
see why the air in contact with the forest must be warmer in winter, cooler
in summer than in situations where it is deprived of that influence."
[Footnote: Memoria Sur Boschi Della Lombardia, p. 45. The results of
recent experiments by Becquerel do not accord with those obtained by
Meguscher, and the former eminent physicist holds that "a tree is warmed in
the air like any inert body." At the same time he asserts, as a fact well
action of the forest upon atmospheric temperature.
Boussingault remarks: "In many flowers there has been observed a very
considerable evolution of heat, at the approach of fecundation. In certain
arums the temperature rises to 40 degrees or 50 degrees Cent. [= 104
degrees or 122 degrees Fahr.] It is very probable that this phenomenon in
general, and varies only in the intensity which it is manifested." [Footnote:
Economie Rurale, i., p. 22.]
If we suppose the fecundation of the flowers of forest trees to be attended
with a tenth only of this calorific power, they could not fail to exert an
important influence on the warmth of the atmospheric strata in contact with
them.
Experiments by Meguscher, in Lombardy, led that observer to conclude
"that the wood of a living tree maintains a temperature of + 12 degrees or
18 degrees Cent. [= 54 degrees, 56 degrees Fahr.] when the temperature of
the air stands at 3 degrees, 7 degrees, and 8 degrees [= 37 degrees, 46
degrees, 47 degrees F.] above zero, and that the internal warmth of the tree
does not rise and fall in proportion to that of the atmosphere. So long as the
latter is below 18 degrees [= 67 degrees Fahr.], that of the tree is always the
highest; but if the temperature of the air rises to 18 degrees, that of the
vegetable growth is the lowest. Since then, trees maintain at all seasons a
constant mean temperature of 12 degrees [= 54 degrees Fahr.], it is easy to
see why the air in contact with the forest must be warmer in winter, cooler
in summer than in situations where it is deprived of that influence."
[Footnote: Memoria Sur Boschi Della Lombardia, p. 45. The results of
recent experiments by Becquerel do not accord with those obtained by
Meguscher, and the former eminent physicist holds that "a tree is warmed in
the air like any inert body." At the same time he asserts, as a fact well
Page 235
ascertained by experiment, that "vegetables possess in themselves the
power or resisting extreme cold for a certain length of time,…. and hence it
is believed that there may exist in the organism of plants a force,
independent of the conduction of caloric, which resists a degree of cold
above the freezing-point." In a following page he cites observations made
by Bugeaud, under the parallel of 58 degrees N. L., between the months of
November and June, during most of which time, of course, vegetable life
was in its deepest lethargy. Bugeaud found that when the temperature of the
air was at -34.60 degrees, that of a poplar was only at -29.70 degrees, which
certainly confirms the doctrine that trees exercise a certain internal
resistance against cold.]
Professor Henry says: "As a general deduction from chemical and
mechanical principles, we think no change of temperature is ever produced
where the actions belonging to one or both of these principles are not
present. Hence, in midwinter, when all vegetable functions are dormant, we
do not believe that any heat is developed by a tree, or that its interior differs
in temperature from its exterior further than it is protected from the external
air. The experiments which have been made on this point, we think, have
been directed by a false analogy. During the active circulation of the sap
and the production of new tissue, variations of temperature belonging
exclusively to the plant may be observed; but it is inconsistent with general
principles that heat should be generated where no change is taking place."
[Footnote: United States Patent Office Report for 1857, p. 504.]
power or resisting extreme cold for a certain length of time,…. and hence it
is believed that there may exist in the organism of plants a force,
independent of the conduction of caloric, which resists a degree of cold
above the freezing-point." In a following page he cites observations made
by Bugeaud, under the parallel of 58 degrees N. L., between the months of
November and June, during most of which time, of course, vegetable life
was in its deepest lethargy. Bugeaud found that when the temperature of the
air was at -34.60 degrees, that of a poplar was only at -29.70 degrees, which
certainly confirms the doctrine that trees exercise a certain internal
resistance against cold.]
Professor Henry says: "As a general deduction from chemical and
mechanical principles, we think no change of temperature is ever produced
where the actions belonging to one or both of these principles are not
present. Hence, in midwinter, when all vegetable functions are dormant, we
do not believe that any heat is developed by a tree, or that its interior differs
in temperature from its exterior further than it is protected from the external
air. The experiments which have been made on this point, we think, have
been directed by a false analogy. During the active circulation of the sap
and the production of new tissue, variations of temperature belonging
exclusively to the plant may be observed; but it is inconsistent with general
principles that heat should be generated where no change is taking place."
[Footnote: United States Patent Office Report for 1857, p. 504.]
Page 236
There can be no doubt that moisture is given, out by trees and evaporated
in extremely cold winter weather, and unless new fluid were supplied from
the roots by the exercise of some vital function, the tree would be exhausted
of its juices before winter was over. But this is not observed to be the fact,
and, though the point is disputed, respectable authorities declare that "wood
felled in the depth of winter is the heaviest and fullest of sap." [Footnote:
Rossmassler, Der Wald, p. 158.] Warm weather in winter, of too short
continuance to affect the temperature of the ground sensibly, stimulates a
free flow of sap in the maple. Thus, in the last week of December, 1862,
and the first week of January, 1863, sugar was made from that tree in
various parts of New England. "A single branch of a tree, admitted into a
warm room in winter through an aperture in a window, opened its buds and
developed its leaves, while the rest of the tree in the external air remained in
its winter sleep." [Footnote: Ibid., p. 160.] Like facts are matter of every-
day observation in graperies where the vine is often planted outside the
wall, the stem passing through an aperture into the warm interior. The roots,
of course, stand in ground of the ordinary winter temperature, but
vegetation is developed in the branches at the pleasure of the gardener. The
roots of forest trees in temperate climates remain, for the most part, in a
moist soil, of a temperature not much below the annual mean, through the
whole winter; and we cannot account for the uninterrupted moisture of the
tree, unless we suppose that the roots furnish a constant supply of water.
Atkinson describes a ravine in a valley in Siberia, which was filled with ice
to the depth of twenty-five feet. Poplars were growing in this ice, which
was thawed to the distance of some inches from the stem. But the surface of
the soil beneath it must have remained still frozen, for the holes around the
trees were full of water resulting from its melting, and this would have
escaped below if the ground had been thawed. In this case, although the
roots had not thawed the thick covering of earth above them, the trunks
must have melted the ice in contact with them. The trees, when observed by
in extremely cold winter weather, and unless new fluid were supplied from
the roots by the exercise of some vital function, the tree would be exhausted
of its juices before winter was over. But this is not observed to be the fact,
and, though the point is disputed, respectable authorities declare that "wood
felled in the depth of winter is the heaviest and fullest of sap." [Footnote:
Rossmassler, Der Wald, p. 158.] Warm weather in winter, of too short
continuance to affect the temperature of the ground sensibly, stimulates a
free flow of sap in the maple. Thus, in the last week of December, 1862,
and the first week of January, 1863, sugar was made from that tree in
various parts of New England. "A single branch of a tree, admitted into a
warm room in winter through an aperture in a window, opened its buds and
developed its leaves, while the rest of the tree in the external air remained in
its winter sleep." [Footnote: Ibid., p. 160.] Like facts are matter of every-
day observation in graperies where the vine is often planted outside the
wall, the stem passing through an aperture into the warm interior. The roots,
of course, stand in ground of the ordinary winter temperature, but
vegetation is developed in the branches at the pleasure of the gardener. The
roots of forest trees in temperate climates remain, for the most part, in a
moist soil, of a temperature not much below the annual mean, through the
whole winter; and we cannot account for the uninterrupted moisture of the
tree, unless we suppose that the roots furnish a constant supply of water.
Atkinson describes a ravine in a valley in Siberia, which was filled with ice
to the depth of twenty-five feet. Poplars were growing in this ice, which
was thawed to the distance of some inches from the stem. But the surface of
the soil beneath it must have remained still frozen, for the holes around the
trees were full of water resulting from its melting, and this would have
escaped below if the ground had been thawed. In this case, although the
roots had not thawed the thick covering of earth above them, the trunks
must have melted the ice in contact with them. The trees, when observed by
Page 237
Atkinson, were in full leaf, but it does not appear at what period the ice
around their stems had melted.
From these facts, and others of the like sort, it would seem that "all
vegetable functions are" not absolutely "dormant in winter, and, therefore,
that trees may give out SOME heat even at that season." [Footnote: All
evergreens, even the broad-leaved trees, resist frosts of extraordinary
severity better than the deciduous trees of the same climates. Is not this
because the vital processes of trees of persistent foliage are less interrupted
during winter than those of trees which annually shed their leaves, and that
therefore more organic heat is developed?
In crossing Mont Cenis in October, 1869, when the leaves of the larches
on the northern slope and near the top of the mountain were entirely dead
and turned brown, I observed that these trees were completely white with
hoar-frost. It was a wonderful sight to see how every leaf was covered with
a delicate deposit of frozen aqueous vapor, which gave the effect of the
most brilliant silver. On the other band, the evergreen coniferae, which were
growing among the larches, and therefore in the same conditions of
exposure, were almost entirely free from frost. The contrast between the
verdure of the leaves of the evergreens and the crystalline splendor of those
of the larches was strikingly beautiful. Was this fact due to a difference in
the color and structure of the leaves, or rather is it a proof of a vital force of
resistance to cold in the living foliage of the evergreen tree The low
temperature of air and soil at which, in the frigid zone, as well as in warmer
latitudes under special circumstances, the processes of vegetation go on,
seems to necessitate the supposition that all the manifestations of vegetable
life are attended with an evolution of heat. In the United States it is
common to protect ice, in ice-houses, by a covering of straw, which
naturally sometimes contains kernels of grain. These often sprout, and even
throw out roots and leaves to a considerable length, in a temperature very
around their stems had melted.
From these facts, and others of the like sort, it would seem that "all
vegetable functions are" not absolutely "dormant in winter, and, therefore,
that trees may give out SOME heat even at that season." [Footnote: All
evergreens, even the broad-leaved trees, resist frosts of extraordinary
severity better than the deciduous trees of the same climates. Is not this
because the vital processes of trees of persistent foliage are less interrupted
during winter than those of trees which annually shed their leaves, and that
therefore more organic heat is developed?
In crossing Mont Cenis in October, 1869, when the leaves of the larches
on the northern slope and near the top of the mountain were entirely dead
and turned brown, I observed that these trees were completely white with
hoar-frost. It was a wonderful sight to see how every leaf was covered with
a delicate deposit of frozen aqueous vapor, which gave the effect of the
most brilliant silver. On the other band, the evergreen coniferae, which were
growing among the larches, and therefore in the same conditions of
exposure, were almost entirely free from frost. The contrast between the
verdure of the leaves of the evergreens and the crystalline splendor of those
of the larches was strikingly beautiful. Was this fact due to a difference in
the color and structure of the leaves, or rather is it a proof of a vital force of
resistance to cold in the living foliage of the evergreen tree The low
temperature of air and soil at which, in the frigid zone, as well as in warmer
latitudes under special circumstances, the processes of vegetation go on,
seems to necessitate the supposition that all the manifestations of vegetable
life are attended with an evolution of heat. In the United States it is
common to protect ice, in ice-houses, by a covering of straw, which
naturally sometimes contains kernels of grain. These often sprout, and even
throw out roots and leaves to a considerable length, in a temperature very
Page 238
little above the freezing-point. Three or four years since I saw a lump of
very clear and apparently solid ice, about eight inches long by six thick, on
which a kernel of grain had sprouted in an ice-house, and sent half a dozen
or more very slender roots into the pores of the ice and through the whole
length of the lump. The young plant must have thrown out a considerable
quantity of heat; for though the ice was, as I have said, otherwise solid, the
pores through which the roots passed were enlarged to perhaps double the
diameter of the fibres, but still not so much as to prevent the retention of
water in them by capillary attraction.]
It does not appear that observations have been made on the special point
of the development of heat in forest trees during florification, or at any
other period of intense vital action; and hence an important element in the
argument remains undetermined. The "circulation of the sap" commences at
a very early period in the spring, and the temperature of the air in contact
with trees may then be sufficiently affected by heat evolved in the vital
processes of vegetation, to raise the thermometric mean of wooded
countries for that season, and, of course, for the year. The determination of
this point is of much greater importance to vegetable physiology than the
question of the winter temperature of trees, because a slight increment of
heat in the trees of a forest might so affect the atmosphere in contact with
them as to make possible the growing of many plants in or near the wood
which could not otherwise he reared in that climate.
The evaporation of the juices of trees and other plants is doubtless their
most important thermoscopic function, and as recent observations lead to
the conclusion that the quantity of moisture exhaled by vegetables has been
hitherto underrated, we must ascribe to this element a higher value than has
been usually assigned to it as a meteorological influence.
very clear and apparently solid ice, about eight inches long by six thick, on
which a kernel of grain had sprouted in an ice-house, and sent half a dozen
or more very slender roots into the pores of the ice and through the whole
length of the lump. The young plant must have thrown out a considerable
quantity of heat; for though the ice was, as I have said, otherwise solid, the
pores through which the roots passed were enlarged to perhaps double the
diameter of the fibres, but still not so much as to prevent the retention of
water in them by capillary attraction.]
It does not appear that observations have been made on the special point
of the development of heat in forest trees during florification, or at any
other period of intense vital action; and hence an important element in the
argument remains undetermined. The "circulation of the sap" commences at
a very early period in the spring, and the temperature of the air in contact
with trees may then be sufficiently affected by heat evolved in the vital
processes of vegetation, to raise the thermometric mean of wooded
countries for that season, and, of course, for the year. The determination of
this point is of much greater importance to vegetable physiology than the
question of the winter temperature of trees, because a slight increment of
heat in the trees of a forest might so affect the atmosphere in contact with
them as to make possible the growing of many plants in or near the wood
which could not otherwise he reared in that climate.
The evaporation of the juices of trees and other plants is doubtless their
most important thermoscopic function, and as recent observations lead to
the conclusion that the quantity of moisture exhaled by vegetables has been
hitherto underrated, we must ascribe to this element a higher value than has
been usually assigned to it as a meteorological influence.
Page 239
The exhalation and evaporation of the juices of trees, by whatever
process effected, take up atmospheric heat and produce a proportional
refrigeration. This effect is not less real, though to common observation less
sensible, in the forest than in meadow or pasture land, and it cannot be
doubted that the local temperature is considerably affected by it. But the
evaporation that cools the air diffuses through it, at the same time, a
medium which powerfully resists the escape of heat from the earth by
radiation. Visible vapors, fogs and clouds, it is well known, prevent frosts
by obstructing radiation, or rather by reflecting back again the heat radiated
by the earth, just as any mechanical screen would do. On the other hand,
fogs and clouds intercept the rays of the sun also, and hinder its heat from
reaching the earth. The invisible vapors given out by leaves impede the
passage of heat reflected and radiated by the earth and by all terrestrial
objects, bat oppose much less resistance to the transmission of direct solar
heat, and indeed the beams of the sun seem more scorching when received
through clear air charged with uncondensed moisture than after passing
through a dry atmosphere. Hence the reduction of temperature by the
evaporation of moisture from vegetation, though sensible, is less than it
would be if water in the gaseous state were as impervious to heat given out
by the sun as to that emitted by terrestrial objects.
Total Influence of the Forest on Temperature.
It has not yet been found practicable to measure, sum up, and equate the
total influence of the forest, its processes and its products, dead and living,
upon temperature, and investigators differ much in their conclusions on this
subject. It seems probable that in every particular case the result is, if not
determined, at least so much modified by local conditions which are
infinitely varied, that no general formula is applicable to the question. In the
report to which I referred on page 163, Gay-Lussac says; "In my opinion we
process effected, take up atmospheric heat and produce a proportional
refrigeration. This effect is not less real, though to common observation less
sensible, in the forest than in meadow or pasture land, and it cannot be
doubted that the local temperature is considerably affected by it. But the
evaporation that cools the air diffuses through it, at the same time, a
medium which powerfully resists the escape of heat from the earth by
radiation. Visible vapors, fogs and clouds, it is well known, prevent frosts
by obstructing radiation, or rather by reflecting back again the heat radiated
by the earth, just as any mechanical screen would do. On the other hand,
fogs and clouds intercept the rays of the sun also, and hinder its heat from
reaching the earth. The invisible vapors given out by leaves impede the
passage of heat reflected and radiated by the earth and by all terrestrial
objects, bat oppose much less resistance to the transmission of direct solar
heat, and indeed the beams of the sun seem more scorching when received
through clear air charged with uncondensed moisture than after passing
through a dry atmosphere. Hence the reduction of temperature by the
evaporation of moisture from vegetation, though sensible, is less than it
would be if water in the gaseous state were as impervious to heat given out
by the sun as to that emitted by terrestrial objects.
Total Influence of the Forest on Temperature.
It has not yet been found practicable to measure, sum up, and equate the
total influence of the forest, its processes and its products, dead and living,
upon temperature, and investigators differ much in their conclusions on this
subject. It seems probable that in every particular case the result is, if not
determined, at least so much modified by local conditions which are
infinitely varied, that no general formula is applicable to the question. In the
report to which I referred on page 163, Gay-Lussac says; "In my opinion we
Page 240
have not yet any positive proof that the forest has, in itself, any real
influence on the climate of a great country, or of a particular locality. By
closely examining the effects of clearing off the woods, we should perhaps
find that, far from being an evil, it is an advantage; but these questions are
so complicated when they are examined in a climatological point of view,
that the solution of them is very difficult, not to say impossible." Becquerel,
on the other hand, considers it certain that in tropical climates the
destruction of the forests is accompanied with an elevation of the mean
temperature, and he thinks it highly probable that it has the same effect in
the temperate zones. The following is the substance of his remarks on this
subject: "Forests act as frigorific causes in three ways:
"1. They shelter the ground against solar irradiation and maintain a
greater humidity.
"2. They produce a cutaneous transpiration by the leaves.
"3. They multiply, by the expansion of their branches, the surfaces which
are cooled by radiation.
"These three causes acting with greater or less force, we must, in the
study of the climatology of a country, take into account the proportion
between the area of the forests and the surface which is bared of trees and
covered with herbs and grasses.
"We should be inclined to believe, a priori, according to the foregoing
considerations, that the clearing of the woods, by raising the temperature
and increasing the dryness of the air, ought to react on climate. There is no
doubt that, if the vast desert of the Sahara were to become wooded in the
course of ages, the sands would cease to be heated as much as at the present
epoch, when the mean temperature is twenty-nine degrees [Centigrade, = 85
degrees Fahr.]. In that case, the ascending currents of warm air would cease,
influence on the climate of a great country, or of a particular locality. By
closely examining the effects of clearing off the woods, we should perhaps
find that, far from being an evil, it is an advantage; but these questions are
so complicated when they are examined in a climatological point of view,
that the solution of them is very difficult, not to say impossible." Becquerel,
on the other hand, considers it certain that in tropical climates the
destruction of the forests is accompanied with an elevation of the mean
temperature, and he thinks it highly probable that it has the same effect in
the temperate zones. The following is the substance of his remarks on this
subject: "Forests act as frigorific causes in three ways:
"1. They shelter the ground against solar irradiation and maintain a
greater humidity.
"2. They produce a cutaneous transpiration by the leaves.
"3. They multiply, by the expansion of their branches, the surfaces which
are cooled by radiation.
"These three causes acting with greater or less force, we must, in the
study of the climatology of a country, take into account the proportion
between the area of the forests and the surface which is bared of trees and
covered with herbs and grasses.
"We should be inclined to believe, a priori, according to the foregoing
considerations, that the clearing of the woods, by raising the temperature
and increasing the dryness of the air, ought to react on climate. There is no
doubt that, if the vast desert of the Sahara were to become wooded in the
course of ages, the sands would cease to be heated as much as at the present
epoch, when the mean temperature is twenty-nine degrees [Centigrade, = 85
degrees Fahr.]. In that case, the ascending currents of warm air would cease,
Page 241
or be less warm, and would not contribute, by descending in our latitudes,
to soften the climate of Western Europe. Thus the clearing of a great
country may react on the climates of regions more or less remote from it.
"The observations by Boussingault leave no doubt on this point. This
writer determined the mean temperature of wooded and of cleared points,
under the same latitude, and at the same elevation above the sea, in
localities comprised between the eleventh degree of north and the fifth
degree of south latitude, that is to say, in the portion of the tropics nearest to
the equator, and where radiation tends powerfully during the night to lower
the temperature under a sky without clouds." [Footnote: Becquerel, Des
Climats, etc., pp. 139-141.]
The result of these observations, which has been pretty generally adopted
by physicists, is that the mean temperature of cleared land in the tropics
appears to be about one degree Centigrade, or a little less than two degrees
of Fahrenheit, above that of the forest. On page 147 of the volume just
cited, Becquerel argues that, inasmuch as the same and sometimes a greater
difference is found in favor of the open ground, at points within the tropics
so elevated as to have a temperate or even a polar climate, we must
conclude that theforests in Northern America exert a refrigerating influence
equally powerful. But the conditions of the soil are so different in the two
regions compared, that I think we cannot, with entire confidence, reason
from the one to the other, and it is much to be desired that observations be
made on the summer and winter temperature of both the air and the ground
in the depths of the North American forests, before it is too late.
Recent inquiries have introduced a new element into the problem of the
influence of the forest on temperature, or rather into the question of the
thermometrical effects of its destruction. I refer to the composition of the
soil in respect to its hygroscopicity or aptitude to absorb humidity, whether
to soften the climate of Western Europe. Thus the clearing of a great
country may react on the climates of regions more or less remote from it.
"The observations by Boussingault leave no doubt on this point. This
writer determined the mean temperature of wooded and of cleared points,
under the same latitude, and at the same elevation above the sea, in
localities comprised between the eleventh degree of north and the fifth
degree of south latitude, that is to say, in the portion of the tropics nearest to
the equator, and where radiation tends powerfully during the night to lower
the temperature under a sky without clouds." [Footnote: Becquerel, Des
Climats, etc., pp. 139-141.]
The result of these observations, which has been pretty generally adopted
by physicists, is that the mean temperature of cleared land in the tropics
appears to be about one degree Centigrade, or a little less than two degrees
of Fahrenheit, above that of the forest. On page 147 of the volume just
cited, Becquerel argues that, inasmuch as the same and sometimes a greater
difference is found in favor of the open ground, at points within the tropics
so elevated as to have a temperate or even a polar climate, we must
conclude that theforests in Northern America exert a refrigerating influence
equally powerful. But the conditions of the soil are so different in the two
regions compared, that I think we cannot, with entire confidence, reason
from the one to the other, and it is much to be desired that observations be
made on the summer and winter temperature of both the air and the ground
in the depths of the North American forests, before it is too late.
Recent inquiries have introduced a new element into the problem of the
influence of the forest on temperature, or rather into the question of the
thermometrical effects of its destruction. I refer to the composition of the
soil in respect to its hygroscopicity or aptitude to absorb humidity, whether
Page 242
in a liquid or a gaseous form, and to the conducting power of the particles
of which it is composed. [Footnote: Composition, texture, and color of soil
are important elements to be considered in estimating the effects of the
removal of the forest upon its thermoscopic action. "Experience has
proved," says Becquerel, "that when the soil is bared, it becomes more or
less heated [by the rays of the sun] according to the nature and the color of
the particles which compose it, and according to its humidity, and that, in
the refrigeration resulting from radiation, we must take into the account the
conducting power of those particles also. Other things being equal, siliceous
and calcareous sands, compared in equal volumes with different
argillaceous earths, with calcareous powder or dust, with humus, with
arable and with garden earth, are the soils which least conduct heat. It is for
this reason that sandy ground, in summer, maintains a high temperature
even during the night. We may hence conclude that when a sandy soil is
stripped of wood, the local temperature will be raised. After the sands
follow successively argillaceous, arable, and garden ground, then humus,
which occupies the lowest rank.
"The retentive power of humus is but half as great as that of calcareous
sand. We will add that the power or retaining heat is proportional to the
density. It has also a relation to the magnitude of the particles. It is for this
reason that ground covered with siliceous pebbles cools more slowly than
siliceous sand, and that pebbly soils are best suited to the cultivation of the
vine, because they advance the ripening of the grape more rapidly than
chalky and clayey earths, which cool quickly. Hence we see that in
examining the calorific effects of clearing forests, it is important to take into
account the properties of the soil laid bare."—Becquerel, Des Climats et des
Sols boises, p. 137.]
The hygroscopicity of humus or vegetable earth is much greater than that
of any mineral soil, and consequently forest ground, where humus abounds,
of which it is composed. [Footnote: Composition, texture, and color of soil
are important elements to be considered in estimating the effects of the
removal of the forest upon its thermoscopic action. "Experience has
proved," says Becquerel, "that when the soil is bared, it becomes more or
less heated [by the rays of the sun] according to the nature and the color of
the particles which compose it, and according to its humidity, and that, in
the refrigeration resulting from radiation, we must take into the account the
conducting power of those particles also. Other things being equal, siliceous
and calcareous sands, compared in equal volumes with different
argillaceous earths, with calcareous powder or dust, with humus, with
arable and with garden earth, are the soils which least conduct heat. It is for
this reason that sandy ground, in summer, maintains a high temperature
even during the night. We may hence conclude that when a sandy soil is
stripped of wood, the local temperature will be raised. After the sands
follow successively argillaceous, arable, and garden ground, then humus,
which occupies the lowest rank.
"The retentive power of humus is but half as great as that of calcareous
sand. We will add that the power or retaining heat is proportional to the
density. It has also a relation to the magnitude of the particles. It is for this
reason that ground covered with siliceous pebbles cools more slowly than
siliceous sand, and that pebbly soils are best suited to the cultivation of the
vine, because they advance the ripening of the grape more rapidly than
chalky and clayey earths, which cool quickly. Hence we see that in
examining the calorific effects of clearing forests, it is important to take into
account the properties of the soil laid bare."—Becquerel, Des Climats et des
Sols boises, p. 137.]
The hygroscopicity of humus or vegetable earth is much greater than that
of any mineral soil, and consequently forest ground, where humus abounds,
Page 243
absorbs the moisture of the atmosphere more rapidly and in larger
proportion than common earth. The condensation of vapor by absorption
develops heat, and consequently elevates the temperature of the soil which
absorbs it, together with that of air in contact with the surface. Von Babo
found the temperature of sandy ground thus raised from 68 degrees to 80
degrees F., that of soil rich in humus from 68 degrees to 88 degrees. The
question of the influence of the woods on temperature does not, in the
present state of our knowledge, admit of precise solution, and, unhappily,
the primitive forests are disappearing so rapidly before the axe of the
woodman, that we shall never be able to estimate with accuracy the
climatological action of the natural wood, though all the physical functions
of artificial plantations will, doubtless, one day be approximately known.
But the value of trees as a mechanical screen to the soil they cover, and
often to ground far to the leeward of them, is most abundantly established,
and this agency alone is important enough to justify extensive plantation in
all countries which do not enjoy this indispensable protection.
Influence of Forests as Inorganic on the Humidity of the Air and the
Earth.
The most important hygroscopic as well as thermoscopic influence of the
forest is, no doubt, that which it exercises on the humidity of the air and the
earth, and this climatic action it exerts partly as dead, partly as living
matter. By its interposition as a curtain between the sky and the ground it
both checks evaporation from the earth, and mechanically intercepts a
certain proportion of the dew and the lighter showers, which would
otherwise moisten the surface of the soil, and restores it to the atmosphere
by exhalation; [Footnote: Mangotti had observed and described, in his usual
picturesque way, the retention of rain-water by the foliage and bark of trees,
proportion than common earth. The condensation of vapor by absorption
develops heat, and consequently elevates the temperature of the soil which
absorbs it, together with that of air in contact with the surface. Von Babo
found the temperature of sandy ground thus raised from 68 degrees to 80
degrees F., that of soil rich in humus from 68 degrees to 88 degrees. The
question of the influence of the woods on temperature does not, in the
present state of our knowledge, admit of precise solution, and, unhappily,
the primitive forests are disappearing so rapidly before the axe of the
woodman, that we shall never be able to estimate with accuracy the
climatological action of the natural wood, though all the physical functions
of artificial plantations will, doubtless, one day be approximately known.
But the value of trees as a mechanical screen to the soil they cover, and
often to ground far to the leeward of them, is most abundantly established,
and this agency alone is important enough to justify extensive plantation in
all countries which do not enjoy this indispensable protection.
Influence of Forests as Inorganic on the Humidity of the Air and the
Earth.
The most important hygroscopic as well as thermoscopic influence of the
forest is, no doubt, that which it exercises on the humidity of the air and the
earth, and this climatic action it exerts partly as dead, partly as living
matter. By its interposition as a curtain between the sky and the ground it
both checks evaporation from the earth, and mechanically intercepts a
certain proportion of the dew and the lighter showers, which would
otherwise moisten the surface of the soil, and restores it to the atmosphere
by exhalation; [Footnote: Mangotti had observed and described, in his usual
picturesque way, the retention of rain-water by the foliage and bark of trees,
Page 244
but I do not know that any attempts were made to measure the quantity thus
intercepted before the experiments of Becquerel, communicated to the
Academy of Sciences in 1866. These experiments embraced three series of
observations continued respectively for periods of a year, a month, and two
days. According to Becquerel's measurements, the quantity falling on bare
and on wooded soil respectively was as 1 to 0.07; 1 to 0.5; and 1 to 0.6, or,
in other words, he found that only from five-tenths to sixty-seven
hundredths of the precipitation reached the ground.—Comptes Rendus de
l'Academie des Sciences, 1866. It seemed, indeed, improbable that in rain-
storms which last not hours but whole days in succession, so large a
proportion of the downfall should continue to be intercepted by forest
vegetation after the leaves, the bark, and the whole framework of the trees
were thoroughly wet, but the conclusions of this eminent physicist appear to
have been generally accepted until the very careful experiments of Mathieu
at the Forest-School of Nancy were made known. The observations of
Mathieu were made in a plantation of deciduous trees forty-two years old,
and were continued through the entire years 1866, 1867, and 1868. The
result was that the precipitation in the wood was to that in an open glade of
several acres near the forest station as 043 to 1,000, and the proportion in
each of the three years was nearly identical. According to Mathieu, then,
only 57 thousandths or 5.7 per cent of the precipitation is intercepted by
trees.—Surrell, Etude sur les Torrents, 2d ed., ii., p. 98.
By order of the Direction of the Forests of the Canton of Berne, a series
of experiments on this subject was commenced at the beginning of the year
1869. During the first seven months of the year (the reports for which alone
I have seen), including, of course, the season when the foliage is most
abundant, as well as that when it is thinnest, the pluviometers in the woods
received only fifteen per cent less than those in the open grounds in the
vicinity.—Risler, in Revue des Eaux et Forets, of 10th January, 1870.] while
in heavier rains, the large drops which fall upon the leaves and branches are
intercepted before the experiments of Becquerel, communicated to the
Academy of Sciences in 1866. These experiments embraced three series of
observations continued respectively for periods of a year, a month, and two
days. According to Becquerel's measurements, the quantity falling on bare
and on wooded soil respectively was as 1 to 0.07; 1 to 0.5; and 1 to 0.6, or,
in other words, he found that only from five-tenths to sixty-seven
hundredths of the precipitation reached the ground.—Comptes Rendus de
l'Academie des Sciences, 1866. It seemed, indeed, improbable that in rain-
storms which last not hours but whole days in succession, so large a
proportion of the downfall should continue to be intercepted by forest
vegetation after the leaves, the bark, and the whole framework of the trees
were thoroughly wet, but the conclusions of this eminent physicist appear to
have been generally accepted until the very careful experiments of Mathieu
at the Forest-School of Nancy were made known. The observations of
Mathieu were made in a plantation of deciduous trees forty-two years old,
and were continued through the entire years 1866, 1867, and 1868. The
result was that the precipitation in the wood was to that in an open glade of
several acres near the forest station as 043 to 1,000, and the proportion in
each of the three years was nearly identical. According to Mathieu, then,
only 57 thousandths or 5.7 per cent of the precipitation is intercepted by
trees.—Surrell, Etude sur les Torrents, 2d ed., ii., p. 98.
By order of the Direction of the Forests of the Canton of Berne, a series
of experiments on this subject was commenced at the beginning of the year
1869. During the first seven months of the year (the reports for which alone
I have seen), including, of course, the season when the foliage is most
abundant, as well as that when it is thinnest, the pluviometers in the woods
received only fifteen per cent less than those in the open grounds in the
vicinity.—Risler, in Revue des Eaux et Forets, of 10th January, 1870.] while
in heavier rains, the large drops which fall upon the leaves and branches are
Page 245
broken into smaller ones, and consequently strike the ground with less
mechanical force, or are perhaps even dispersed into vapor without reaching
it. [Footnote: We are not, indeed, to suppose that the condensation of vapor
and the evaporation of water are going on in the same stratum of air at the
same time, or, in other words, that vapor is condensed into rain-drops, and
rain-drops evaporated, under the same conditions; but rain formed in one
stratum may fall through another, where vapor would not be condensed.
Two saturated strata of different temperatures may be brought into contact
in the higher regions, and discharge large rain-drops, which, it not divided
by some obstruction, will reach the ground, though passing through strata
which would vaporize them if they were in a state of more minute division.]
The vegetable mould, resulting from the decomposition of leaves and of
wood, serves as a perpetual mulch to forest-soil by carpeting the ground
with a spongy covering which obstructs the evaporation from the mineral
earth below, [Footnote: The only direct experiments known to me on the
evaporation from the SURFACE of the forest are those of Mathieu.—
Surrell, Etude sur les Torrents, 2d ed., ii, p. 99.
These experiments were continued from March to December, inclusive,
of the year 1868. It was found that during those months the evaporation
from a recipient placed on the ground in a plantation of deciduous trees
sixty-two years old, was less than one-fifth of that from a recipient of like
form and dimensions placed in the open country.] drinks up the rains and
melting snows that would otherwise flow rapidly over the surface and
perhaps be conveyed to the distant sea, and then slowly gives out, by
evaporation, infiltration, and percolation, the moisture thus imbibed. The
roots, too, penetrate far below the superficial soil, conduct water along their
surface to the lower depths to which they reach, and thus by partially
draining the superior strata, remove a certain quantity of moisture out of the
reach of evaporation. The Forest as Organic.
mechanical force, or are perhaps even dispersed into vapor without reaching
it. [Footnote: We are not, indeed, to suppose that the condensation of vapor
and the evaporation of water are going on in the same stratum of air at the
same time, or, in other words, that vapor is condensed into rain-drops, and
rain-drops evaporated, under the same conditions; but rain formed in one
stratum may fall through another, where vapor would not be condensed.
Two saturated strata of different temperatures may be brought into contact
in the higher regions, and discharge large rain-drops, which, it not divided
by some obstruction, will reach the ground, though passing through strata
which would vaporize them if they were in a state of more minute division.]
The vegetable mould, resulting from the decomposition of leaves and of
wood, serves as a perpetual mulch to forest-soil by carpeting the ground
with a spongy covering which obstructs the evaporation from the mineral
earth below, [Footnote: The only direct experiments known to me on the
evaporation from the SURFACE of the forest are those of Mathieu.—
Surrell, Etude sur les Torrents, 2d ed., ii, p. 99.
These experiments were continued from March to December, inclusive,
of the year 1868. It was found that during those months the evaporation
from a recipient placed on the ground in a plantation of deciduous trees
sixty-two years old, was less than one-fifth of that from a recipient of like
form and dimensions placed in the open country.] drinks up the rains and
melting snows that would otherwise flow rapidly over the surface and
perhaps be conveyed to the distant sea, and then slowly gives out, by
evaporation, infiltration, and percolation, the moisture thus imbibed. The
roots, too, penetrate far below the superficial soil, conduct water along their
surface to the lower depths to which they reach, and thus by partially
draining the superior strata, remove a certain quantity of moisture out of the
reach of evaporation. The Forest as Organic.
Page 246
These are the principal modes in which the humidity of the atmosphere is
affected by the forest regarded as lifeless matter. Let us inquire how its
organic processes act upon this meteorological element. The commonest
observation shows that the wood and bark of living trees are always more or
less pervaded with watery and other fluids, one of which, the sap, is very
abundant in trees of deciduous foliage when the buds begin to swell and the
leaves to develop themselves in the spring. This fluid is drawn principally,
if not entirely, from the ground by the absorbent action of the roots, for
though Schacht and some other eminent botanical physiologists have
maintained that water is absorbed by the leaves and bark of trees, yet most
experiments lead to the contrary result, and it is now generally held that no
water is taken in by the pores of vegetables. Late observations by Cailletet,
in France, however, tend to the establishment of a new doctrine on this
subject which solves many difficulties and will probably be accepted by
botanists as definitive. Cailletet finds that under normal conditions, that is,
when the soil is humid enough to supply sufficient moisture through the
roots, no water is absorbed by the leaves, buds, or bark of plants, but when
the roots are unable to draw from the earth the requisite quantity of this
fluid, the vegetable pores in contact with the atmosphere absorb it from that
source.
Popular opinion, indeed, supposes that all the vegetable fluids, during the
entire period of growth, are drawn from the bosom of the earth, and that the
wood and other products of the tree are wholly formed from matter held in
solution in the water abstracted by the roots from the ground. This is an
error, for the solid matter of the tree, in a certain proportion not important to
our present inquiry, is received from the atmosphere in a gaseous form,
through the pores of the leaves and of the young shoots, and, as we have
just seen, moisture is sometimes supplied to trees by the atmosphere. The
amount of water taken up by the roots, however, is vastly greater than that
imbibed through the leaves and bark, especially at the season when the sap
affected by the forest regarded as lifeless matter. Let us inquire how its
organic processes act upon this meteorological element. The commonest
observation shows that the wood and bark of living trees are always more or
less pervaded with watery and other fluids, one of which, the sap, is very
abundant in trees of deciduous foliage when the buds begin to swell and the
leaves to develop themselves in the spring. This fluid is drawn principally,
if not entirely, from the ground by the absorbent action of the roots, for
though Schacht and some other eminent botanical physiologists have
maintained that water is absorbed by the leaves and bark of trees, yet most
experiments lead to the contrary result, and it is now generally held that no
water is taken in by the pores of vegetables. Late observations by Cailletet,
in France, however, tend to the establishment of a new doctrine on this
subject which solves many difficulties and will probably be accepted by
botanists as definitive. Cailletet finds that under normal conditions, that is,
when the soil is humid enough to supply sufficient moisture through the
roots, no water is absorbed by the leaves, buds, or bark of plants, but when
the roots are unable to draw from the earth the requisite quantity of this
fluid, the vegetable pores in contact with the atmosphere absorb it from that
source.
Popular opinion, indeed, supposes that all the vegetable fluids, during the
entire period of growth, are drawn from the bosom of the earth, and that the
wood and other products of the tree are wholly formed from matter held in
solution in the water abstracted by the roots from the ground. This is an
error, for the solid matter of the tree, in a certain proportion not important to
our present inquiry, is received from the atmosphere in a gaseous form,
through the pores of the leaves and of the young shoots, and, as we have
just seen, moisture is sometimes supplied to trees by the atmosphere. The
amount of water taken up by the roots, however, is vastly greater than that
imbibed through the leaves and bark, especially at the season when the sap
Page 247
is most abundant, and when the leaves are yet in embryo. The quantity of
water thus received from the air and the earth, in a single year, even by a
wood of only a hundred acres, is very great, though experiments are
wanting to furnish the data for even an approximate estimate of its measure;
for only the vaguest conclusions can be drawn from the observations which
have been made on the imbibition and exhalation of water by trees and
other plants reared in artificial conditions diverse from those of the natural
forest. [Footnote: The experiments of Hales and others on the absorption
and exhalation of vegetables are of high physiological interest; but
observations on sunflowers, cabbages, hops, and single branches of isolated
trees, growing in artificially prepared soils and under artificial conditions,
furnish no trustworthy data for computing the quantity of water received
and given off by the natural wood.]
Flow of Sap.
The amount of sap which can be withdrawn from living trees furnishes,
not indeed a measure of the quantity of water sucked up by their roots from
the ground—for we cannot extract from a tree its whole moisture—but
numerical data which may aid the imagination to form a general notion of
the powerful action of the forest as an absorbent of humidity from the earth.
The only forest-tree known to Europe and North America, the sap of
which is largely enough applied to economical uses to have made the
amount of its flow a matter of practical importance and popular
observation, is the sugar maple, Acer saccharinum, of the Anglo-American
Provinces and States. In the course of a single "sugar season," which lasts
ordinarily from twenty-five to thirty days, a sugar maple two feet in
diameter will yield not less than twenty gallons of sap, and sometimes much
more. [Footnote: Emerson (Trees of Massachusetts. p. 403) mentions a
maple six feet in diameter, as having yielded a barrel, or thirty-one and a
water thus received from the air and the earth, in a single year, even by a
wood of only a hundred acres, is very great, though experiments are
wanting to furnish the data for even an approximate estimate of its measure;
for only the vaguest conclusions can be drawn from the observations which
have been made on the imbibition and exhalation of water by trees and
other plants reared in artificial conditions diverse from those of the natural
forest. [Footnote: The experiments of Hales and others on the absorption
and exhalation of vegetables are of high physiological interest; but
observations on sunflowers, cabbages, hops, and single branches of isolated
trees, growing in artificially prepared soils and under artificial conditions,
furnish no trustworthy data for computing the quantity of water received
and given off by the natural wood.]
Flow of Sap.
The amount of sap which can be withdrawn from living trees furnishes,
not indeed a measure of the quantity of water sucked up by their roots from
the ground—for we cannot extract from a tree its whole moisture—but
numerical data which may aid the imagination to form a general notion of
the powerful action of the forest as an absorbent of humidity from the earth.
The only forest-tree known to Europe and North America, the sap of
which is largely enough applied to economical uses to have made the
amount of its flow a matter of practical importance and popular
observation, is the sugar maple, Acer saccharinum, of the Anglo-American
Provinces and States. In the course of a single "sugar season," which lasts
ordinarily from twenty-five to thirty days, a sugar maple two feet in
diameter will yield not less than twenty gallons of sap, and sometimes much
more. [Footnote: Emerson (Trees of Massachusetts. p. 403) mentions a
maple six feet in diameter, as having yielded a barrel, or thirty-one and a
Page 248
half gallons, of sap in twenty-four hours, and another, the dimensions of
which are not stated, as having yielded one hundred and seventy-five
gallons in the course of the season.
The Cultivator, an American agricultural journal, for June, 1842, states
that twenty gallons of sap were drawn in eighteen hours from a single
maple, two and a half feet in diameter, in the town of Warner, New
Hampshire, and the truth of this account has been verified by personal
inquiry made in my behalf. This tree was of the original forest growth, and
had been left standing when the ground around it was cleared. It was tapped
only every other year, and then with six or eight incisions. Dr. Williams
(History of Vermont, i., p. 01) says: "A man much employed in milking
maple sugar, found that, for twenty-one days together, a maple-tree
discharged seven and a half gallons per day."
An intelligent correspondent, of much experience in the manufacture of
maple sugar, writes me that a second-growth maple, of about two feet in
diameter, standing in open ground, tapped with four incisions, has, for
several seasons, generally run eight gallons per day in fair weather. He
speaks of a very large tree, from which sixty gallons were drawn in the
course of a season, and of another, something more than three feet through,
which made forty-two pounds of wet sugar, and must have yielded not less
than one hundred and fifty gallons.] This, however, is but a trifling
proportion of the water abstracted from the earth by the roots during this
season; for all this fluid runs from two or three incisions or auger-holes, so
narrow as to intercept the current of comparatively few sap vessels, and
besides, experience shows that large as is the quantity withdrawn from the
circulation, it is relatively too small to affect very sensibly the growth of the
tree. [Footnote: Tapping does not check the growth, but does injure the
quality of the wood of maples. The wood of trees often tapped is lighter and
less dense than that of trees which have not been tapped, and gives less heat
which are not stated, as having yielded one hundred and seventy-five
gallons in the course of the season.
The Cultivator, an American agricultural journal, for June, 1842, states
that twenty gallons of sap were drawn in eighteen hours from a single
maple, two and a half feet in diameter, in the town of Warner, New
Hampshire, and the truth of this account has been verified by personal
inquiry made in my behalf. This tree was of the original forest growth, and
had been left standing when the ground around it was cleared. It was tapped
only every other year, and then with six or eight incisions. Dr. Williams
(History of Vermont, i., p. 01) says: "A man much employed in milking
maple sugar, found that, for twenty-one days together, a maple-tree
discharged seven and a half gallons per day."
An intelligent correspondent, of much experience in the manufacture of
maple sugar, writes me that a second-growth maple, of about two feet in
diameter, standing in open ground, tapped with four incisions, has, for
several seasons, generally run eight gallons per day in fair weather. He
speaks of a very large tree, from which sixty gallons were drawn in the
course of a season, and of another, something more than three feet through,
which made forty-two pounds of wet sugar, and must have yielded not less
than one hundred and fifty gallons.] This, however, is but a trifling
proportion of the water abstracted from the earth by the roots during this
season; for all this fluid runs from two or three incisions or auger-holes, so
narrow as to intercept the current of comparatively few sap vessels, and
besides, experience shows that large as is the quantity withdrawn from the
circulation, it is relatively too small to affect very sensibly the growth of the
tree. [Footnote: Tapping does not check the growth, but does injure the
quality of the wood of maples. The wood of trees often tapped is lighter and
less dense than that of trees which have not been tapped, and gives less heat
Page 249
in burning. No difference has been observed in the bursting of the buds of
tapped and untapped trees.] The number of large maple-trees on an acre is
frequently not less than fifty, [Footnote: Dr. Rush, in a letter to Jefferson,
states the number of maples fit for tapping on an acre at from thirty to fifty.
"This," observes my correspondent, "is correct with regard to the original
growth, which is always more or less intermixed with other trees; but in
second growth, composed of maples alone, the number greatly exceeds this.
I have had the maples on a quarter of an acre, which I thought about an
average of second-growth 'maple orchards,' counted. The number was found
to be fifty-two, of which thirty-two were ten inches or more in diameter,
and, of course, large enough to tap. This gives two hundred and eight trees
to the acre, one hundred and twenty-eight of which were of proper size for
tapping."] and of course the quantity of moisture abstracted from the soil by
this tree alone is measured by thousands of gallons to the acre. The sugar
orchards, as they are called, contain also many young maples too small for
tapping, and numerous other trees—two of which, at least, the black birch,
Betula lenta, and yellow birch, Betula excelsa, both very common in the
same climate, are far more abundant in sap than the maple [Footnote: The
correspondent already referred to informs me that a black birch, tapped
about noon with two incisions, was found the next morning to have yielded
sixteen gallons. Dr. Williams (History of Vermont, i., p. 91) says: "A large
birch, tapped in the spring, ran at the rate of five gallons an hour when first
tapped. Eight or nine days after, it was found to run at the rate of about two
and a half gallons an hour, and at the end of fifteen days the discharge
continued in nearly the same quantity. The sap continued to flow for four or
five weeks, and it was the opinion of the observers that it must have yielded
as much as sixty barrels [l,800 gallons]."]—are scattered among the sugar-
trees; for the North American native forests are remarkable for the mixture
of their crops. The sap of the maple, and of other trees with deciduous
leaves which grow in the same climate, flows most freely in the early
tapped and untapped trees.] The number of large maple-trees on an acre is
frequently not less than fifty, [Footnote: Dr. Rush, in a letter to Jefferson,
states the number of maples fit for tapping on an acre at from thirty to fifty.
"This," observes my correspondent, "is correct with regard to the original
growth, which is always more or less intermixed with other trees; but in
second growth, composed of maples alone, the number greatly exceeds this.
I have had the maples on a quarter of an acre, which I thought about an
average of second-growth 'maple orchards,' counted. The number was found
to be fifty-two, of which thirty-two were ten inches or more in diameter,
and, of course, large enough to tap. This gives two hundred and eight trees
to the acre, one hundred and twenty-eight of which were of proper size for
tapping."] and of course the quantity of moisture abstracted from the soil by
this tree alone is measured by thousands of gallons to the acre. The sugar
orchards, as they are called, contain also many young maples too small for
tapping, and numerous other trees—two of which, at least, the black birch,
Betula lenta, and yellow birch, Betula excelsa, both very common in the
same climate, are far more abundant in sap than the maple [Footnote: The
correspondent already referred to informs me that a black birch, tapped
about noon with two incisions, was found the next morning to have yielded
sixteen gallons. Dr. Williams (History of Vermont, i., p. 91) says: "A large
birch, tapped in the spring, ran at the rate of five gallons an hour when first
tapped. Eight or nine days after, it was found to run at the rate of about two
and a half gallons an hour, and at the end of fifteen days the discharge
continued in nearly the same quantity. The sap continued to flow for four or
five weeks, and it was the opinion of the observers that it must have yielded
as much as sixty barrels [l,800 gallons]."]—are scattered among the sugar-
trees; for the North American native forests are remarkable for the mixture
of their crops. The sap of the maple, and of other trees with deciduous
leaves which grow in the same climate, flows most freely in the early
Page 250
spring, and especially in clear weather, when the nights are frosty and the
days warm; for it is then that the melting snows supply the earth with
moisture in the justest proportion, and that the absorbent power of the roots
is stimulated to its highest activity.
When the buds are ready to burst, and the green leaves begin to show
themselves beneath their scaly covering, the ground has become drier, the
absorption by the roots is diminished, and the sap, being immediately
employed in the formation of the foliage, can be extracted from the stem in
only small quantities.
Absorption and Exhalation by Foliage.
The leaves now commence the process of absorption, and imbibe both
uncombined gases and an unascertained but probably inconsiderable
quantity of aqueous vapor from the humid atmosphere of spring which
bathes them.
The organic action of the tree, as thus far described, tends to the
desiccation of air and earth; but when we consider what volumes of water
are daily absorbed by a large tree, and how small a proportion of the weight
of this fluid consists of matter which, at the period when the flow of sap is
freest, enters into new combinations, and becomes a part of the solid
framework of the vegetable, or a component of its deciduous products, it
becomes evident that the superfluous moisture must somehow be carried
back again almost as rapidly as it flows into the tree. At the very
commencement of vegetation in spring, some of this fluid certainly escapes
through the buds, the nascent foliage, and the pores of the bark, and
vegetable physiology tells us that there is a current of sap towards the roots
as well as from them. [Footnote: "The elaborated sap, passing out of the
leaves, is received into the inner bark, . . . and a part of what descends finds
days warm; for it is then that the melting snows supply the earth with
moisture in the justest proportion, and that the absorbent power of the roots
is stimulated to its highest activity.
When the buds are ready to burst, and the green leaves begin to show
themselves beneath their scaly covering, the ground has become drier, the
absorption by the roots is diminished, and the sap, being immediately
employed in the formation of the foliage, can be extracted from the stem in
only small quantities.
Absorption and Exhalation by Foliage.
The leaves now commence the process of absorption, and imbibe both
uncombined gases and an unascertained but probably inconsiderable
quantity of aqueous vapor from the humid atmosphere of spring which
bathes them.
The organic action of the tree, as thus far described, tends to the
desiccation of air and earth; but when we consider what volumes of water
are daily absorbed by a large tree, and how small a proportion of the weight
of this fluid consists of matter which, at the period when the flow of sap is
freest, enters into new combinations, and becomes a part of the solid
framework of the vegetable, or a component of its deciduous products, it
becomes evident that the superfluous moisture must somehow be carried
back again almost as rapidly as it flows into the tree. At the very
commencement of vegetation in spring, some of this fluid certainly escapes
through the buds, the nascent foliage, and the pores of the bark, and
vegetable physiology tells us that there is a current of sap towards the roots
as well as from them. [Footnote: "The elaborated sap, passing out of the
leaves, is received into the inner bark, . . . and a part of what descends finds
Page 251
its way even to the ends of the roots, and is all along diffused laterally into
the stem, where it meets and mingles with the ascending crude sap or raw
material. So there is no separate circulation of the two kinds of sap; and no
crude sap exists separately in any part of the plant. Even in the root, where
it enters, this mingles at once with some elaborated sap already there."—
Gray, How Plants Grow, Section 273.]
I do not know that the exudation of water into the earth, through the bark
or at the extremities of these latter organs, has been proved, but the other
known modes of carrying off the surplus do not seem adequate to dispose of
it at the almost leafless period when it is most abundantly received, and it is
possible that the roots may, to some extent, drain as well as flood the water-
courses of their stem. Later in the season the roots absorb less, and the now
developed leaves exhale an increased quantity of moisture into the air. In
any event, all the water derived by the growing tree from the atmosphere
and the ground is parted with by transpiration or exudation, after having
surrendered to the plant the small proportion of matter required for
vegetable growth which it held in solution or suspension. [Footnote: Ward's
tight glazed cases for raising and especially for transporting plants, go far to
prove that water only circulates through vegetables, and is again and again
absorbed and transpired by organs appropriated to these functions.
Seeds, growing grasses, shrubs, or trees planted in proper earth,
moderately watered and covered with a glass bell or close frame of glass,
live for months, and even years, with only the original store of air and
water. In one of Ward's early experiments, a spire of grass and a fern, which
sprang up in a corked bottle containing a little moist earth introduced as a
bed for a snail, lived and flourished for eighteen years without a new supply
of either fluid. In these boxes the plants grow till the enclosed air is
exhausted of the gaseous constituents of vegetation, and till the water has
yielded up the assimilable matter it held in solution, and dissolved and
the stem, where it meets and mingles with the ascending crude sap or raw
material. So there is no separate circulation of the two kinds of sap; and no
crude sap exists separately in any part of the plant. Even in the root, where
it enters, this mingles at once with some elaborated sap already there."—
Gray, How Plants Grow, Section 273.]
I do not know that the exudation of water into the earth, through the bark
or at the extremities of these latter organs, has been proved, but the other
known modes of carrying off the surplus do not seem adequate to dispose of
it at the almost leafless period when it is most abundantly received, and it is
possible that the roots may, to some extent, drain as well as flood the water-
courses of their stem. Later in the season the roots absorb less, and the now
developed leaves exhale an increased quantity of moisture into the air. In
any event, all the water derived by the growing tree from the atmosphere
and the ground is parted with by transpiration or exudation, after having
surrendered to the plant the small proportion of matter required for
vegetable growth which it held in solution or suspension. [Footnote: Ward's
tight glazed cases for raising and especially for transporting plants, go far to
prove that water only circulates through vegetables, and is again and again
absorbed and transpired by organs appropriated to these functions.
Seeds, growing grasses, shrubs, or trees planted in proper earth,
moderately watered and covered with a glass bell or close frame of glass,
live for months, and even years, with only the original store of air and
water. In one of Ward's early experiments, a spire of grass and a fern, which
sprang up in a corked bottle containing a little moist earth introduced as a
bed for a snail, lived and flourished for eighteen years without a new supply
of either fluid. In these boxes the plants grow till the enclosed air is
exhausted of the gaseous constituents of vegetation, and till the water has
yielded up the assimilable matter it held in solution, and dissolved and
Page 252
supplied to the roots the nutriment contained in the earth in which they are
planted. After this, they continue for a long time in a state of vegetable
sleep, but if fresh air and water be introduced into the cases, or the plants be
transplanted into open ground, they rouse themselves to renewed life, and
grow vigorously, without appearing to have suffered from their long
imprisonment. The water transpired by the leaves is partly absorbed by the
earth directly from the air, partly condensed on the glass, along which it
trickles down to the earth, enters the roots again, and thus continually
repeats the circuit. See Aus der Natur, 21, B. S. 537.] The hygrometrical
equilibrium is then restored, so far as this: the tree yields up again the
moisture it had drawn from the earth and the air, though it does not return it
each to each; for the vapor carried off by transpiration greatly exceeds the
quantity of water absorbed by the foliage from the atmosphere, and the
amount, if any, carried back to the ground by the roots.
The present estimates of some eminent vegetable physiologists in regard
to the quantity of aqueous vapor exhaled by trees and taken up by the
atmosphere are much greater than those of former inquirers. Direct and
satisfactory experiments on this point are wanting, and it is not easy to
imagine how they could be made on a sufficiently extensive and
comprehensive scale. Our conclusions must therefore be drawn from
observations on small plants, or separate branches of trees, and of course
are subject to much uncertainty. Nevertheless, Schleiden, arguing from such
analogies, comes to the surprising result, that a wood evaporates ten times
as much water as it receives from atmospheric precipitation. [Footnote: Fur
Baum und Wald, pp. 46, 47, notes. Pfaff, too, experimenting on branches of
a living oak, weighed immediately after being cut from the tree, and again
after an exposure to the air for three minutes, and computing the superficial
measure of all the leaves of the tree, concludes that an oak-tree evaporates,
during the season of growth, eight and a half times the mean amount of
rain-fall on an area equal to that shaded by the tree.] In the Northern and
planted. After this, they continue for a long time in a state of vegetable
sleep, but if fresh air and water be introduced into the cases, or the plants be
transplanted into open ground, they rouse themselves to renewed life, and
grow vigorously, without appearing to have suffered from their long
imprisonment. The water transpired by the leaves is partly absorbed by the
earth directly from the air, partly condensed on the glass, along which it
trickles down to the earth, enters the roots again, and thus continually
repeats the circuit. See Aus der Natur, 21, B. S. 537.] The hygrometrical
equilibrium is then restored, so far as this: the tree yields up again the
moisture it had drawn from the earth and the air, though it does not return it
each to each; for the vapor carried off by transpiration greatly exceeds the
quantity of water absorbed by the foliage from the atmosphere, and the
amount, if any, carried back to the ground by the roots.
The present estimates of some eminent vegetable physiologists in regard
to the quantity of aqueous vapor exhaled by trees and taken up by the
atmosphere are much greater than those of former inquirers. Direct and
satisfactory experiments on this point are wanting, and it is not easy to
imagine how they could be made on a sufficiently extensive and
comprehensive scale. Our conclusions must therefore be drawn from
observations on small plants, or separate branches of trees, and of course
are subject to much uncertainty. Nevertheless, Schleiden, arguing from such
analogies, comes to the surprising result, that a wood evaporates ten times
as much water as it receives from atmospheric precipitation. [Footnote: Fur
Baum und Wald, pp. 46, 47, notes. Pfaff, too, experimenting on branches of
a living oak, weighed immediately after being cut from the tree, and again
after an exposure to the air for three minutes, and computing the superficial
measure of all the leaves of the tree, concludes that an oak-tree evaporates,
during the season of growth, eight and a half times the mean amount of
rain-fall on an area equal to that shaded by the tree.] In the Northern and
Page 253
Eastern States of the Union, the mean precipitation during the period of
forest growth, that is from the swelling of the buds in the spring to the
ripening of the fruit, the hardening of the young shoots, and the full
perfection of the other annual products of the tree, exceeds on the average
twenty-four inches. Taking this estimate, the evaporation from the forest
would be equal to a precipitation of two hundred and forty inches, or very
nearly one hundred and fifty standard gallons to the square foot of surface.
The first questions which suggest themselves upon this statement are:
what becomes of this immense quantity of water and from what source does
the tree derive it We are told in reply that it is absorbed from the air by the
humus and mineral soil of the wood, and supplied again to the tree through
its roots, by a circulation analogous to that observed in Ward's air-tight
cases. When we recall the effect produced on the soil even of a thick wood
by a rain-fall of one inch, we find it hard to believe that two hundred and
forty times that quantity, received by the ground between early spring and
autumn, would not keep it in a state of perpetual saturation, and speedily
convert the forest into a bog.
No such power of absorption of moisture by the earth from the
atmosphere, or anything approaching it, has ever been shown by
experiment, and all scientific observation contradicts the supposition.
Schubler found that in seventy-two hours thoroughly dried humus, which is
capable of taking up twice its own weight of water in the liquid state,
absorbed from the atmosphere only twelve per cent. of its weight of
humidity; garden-earth five and one-fifth per cent. and ordinary cultivated
soil two and one-third per cent. After seventy-two hours, and, in most of his
experiments with thirteen different earths, after forty-eight hours, no further
absorption took place. Wilhelm, experimenting with air-dried field-earth,
exposed to air in contact with water and protected by a bell-glass, found
that the absorption amounted in seventy-two hours to two per cent. and a
forest growth, that is from the swelling of the buds in the spring to the
ripening of the fruit, the hardening of the young shoots, and the full
perfection of the other annual products of the tree, exceeds on the average
twenty-four inches. Taking this estimate, the evaporation from the forest
would be equal to a precipitation of two hundred and forty inches, or very
nearly one hundred and fifty standard gallons to the square foot of surface.
The first questions which suggest themselves upon this statement are:
what becomes of this immense quantity of water and from what source does
the tree derive it We are told in reply that it is absorbed from the air by the
humus and mineral soil of the wood, and supplied again to the tree through
its roots, by a circulation analogous to that observed in Ward's air-tight
cases. When we recall the effect produced on the soil even of a thick wood
by a rain-fall of one inch, we find it hard to believe that two hundred and
forty times that quantity, received by the ground between early spring and
autumn, would not keep it in a state of perpetual saturation, and speedily
convert the forest into a bog.
No such power of absorption of moisture by the earth from the
atmosphere, or anything approaching it, has ever been shown by
experiment, and all scientific observation contradicts the supposition.
Schubler found that in seventy-two hours thoroughly dried humus, which is
capable of taking up twice its own weight of water in the liquid state,
absorbed from the atmosphere only twelve per cent. of its weight of
humidity; garden-earth five and one-fifth per cent. and ordinary cultivated
soil two and one-third per cent. After seventy-two hours, and, in most of his
experiments with thirteen different earths, after forty-eight hours, no further
absorption took place. Wilhelm, experimenting with air-dried field-earth,
exposed to air in contact with water and protected by a bell-glass, found
that the absorption amounted in seventy-two hours to two per cent. and a
Page 254
very small fraction, nearly the whole of which was taken up in the first
forty-eight hours. In other experiments with carefully heat-dried field-soil,
the absorption was five per cent. in eighty-four hours, and when the water
was first warmed to secure the complete saturation of the air, air-dried
garden-earth absorbed five and one-tenth per cent. in seventy-two hours.
In nature, the conditions are never so favorable to the absorption of vapor
as in those experiments. The ground is more compact and of course offers
less surface to the air, and, especially in the wood, it is already in a state
approaching saturation. Hence, both these physicists conclude that the
quantity of aqueous vapor absorbed by the earth from the air is so
inconsiderable "that we can ascribe to it no important influence on
vegetation." [Footnote: Wilhelm, Der Boden und das Wasser, pp. 14,20.]
Besides this, trees often grow luxuriantly on narrow ridges, on steep
declivities, on partially decayed stumps many feet above the ground, on
walls of high buildings, and on rocks, in situations where the earth within
reach of their roots could not possibly contain the tenth part of the water
which, according to Schleiden and Pfaff, they evaporate in a day. There are,
too, forests of great extent on high bluffs and well-drained table-lands,
where there can exist, neither in the subsoil nor in infiltration from
neighboring regions, an adequate source of supply for such consumption. It
must be remembered, also, that in the wood the leaves of the trees shade
each other, and only the highest stratum of foliage receives the full
influence of heat and light; and besides, the air in the forest is almost
stagnant, while in the experiments of Unger, Marshal, Vaillant, Pfaff and
others, the branches were freely exposed to light, sun, and atmospheric
currents. Such observations can authorize no conclusions respecting the
quantitative action of leaves of forest trees in normal conditions.
Further, allowing two hundred days for the period of forest vital action,
the wood must, according to Schleiden's position, exhale a quantity of
forty-eight hours. In other experiments with carefully heat-dried field-soil,
the absorption was five per cent. in eighty-four hours, and when the water
was first warmed to secure the complete saturation of the air, air-dried
garden-earth absorbed five and one-tenth per cent. in seventy-two hours.
In nature, the conditions are never so favorable to the absorption of vapor
as in those experiments. The ground is more compact and of course offers
less surface to the air, and, especially in the wood, it is already in a state
approaching saturation. Hence, both these physicists conclude that the
quantity of aqueous vapor absorbed by the earth from the air is so
inconsiderable "that we can ascribe to it no important influence on
vegetation." [Footnote: Wilhelm, Der Boden und das Wasser, pp. 14,20.]
Besides this, trees often grow luxuriantly on narrow ridges, on steep
declivities, on partially decayed stumps many feet above the ground, on
walls of high buildings, and on rocks, in situations where the earth within
reach of their roots could not possibly contain the tenth part of the water
which, according to Schleiden and Pfaff, they evaporate in a day. There are,
too, forests of great extent on high bluffs and well-drained table-lands,
where there can exist, neither in the subsoil nor in infiltration from
neighboring regions, an adequate source of supply for such consumption. It
must be remembered, also, that in the wood the leaves of the trees shade
each other, and only the highest stratum of foliage receives the full
influence of heat and light; and besides, the air in the forest is almost
stagnant, while in the experiments of Unger, Marshal, Vaillant, Pfaff and
others, the branches were freely exposed to light, sun, and atmospheric
currents. Such observations can authorize no conclusions respecting the
quantitative action of leaves of forest trees in normal conditions.
Further, allowing two hundred days for the period of forest vital action,
the wood must, according to Schleiden's position, exhale a quantity of
Page 255
moisture equal to an inch and one-fifth of precipitation per day, and it is
hardly conceivable that so large a volume of aqueous vapor, in addition to
the supply from other sources, could be diffused through the ambient
atmosphere without manifesting its presence by ordinary hygrometrical
tests much more energetically than it has been proved to do, and in fact, the
observations recorded by Ebermayer show that though the RELATIVE
humidity of the atmosphere is considerably greater in the cooler
temperature of the wood, its ABSOLUTE humidity does not sensibly differ
from that of the air in open ground. [Footnote: Ebermeyer, Die
Physikalischen, Einwirkungen des Waldes, i., pp. 150 et seqq. It may be
well here to guard my readers against the common error which supposes
that a humid condition of the AIR is necessarily indicated by the presence
of fog or visible vapor. The air is rendered humid by containing
INVISIBLE vapor, and it becomes drier by the condensation of such vapor
into fog, composed of solid globules or of hollow vesicles of water—for it
is a disputed point whether the particles of fog are solid or vesicular. Hence,
though the ambient atmosphere may hold in suspension, in the form of fog,
water enough to obscure its transparency, and to produce the sensation of
moisture on the skin, the air, in which the finely divided water floats, may
be charged with even less than an average proportion of humidity.]
The daily discharge of a quantity of aqueous vapor corresponding to a
rain-fall of one inch and a fifth into the cool air of the forest would produce
a perpetual shower, or at least drizzle, unless, indeed, we suppose a rapidity
of absorption and condensation by the ground, and of transmission through
the soil to the roots and through them and the vessels of the tree to the
leaves, much greater than has been shown by direct observation.
Notwithstanding the high authority of Schleiden, therefore, it seems
impossible to reconcile his estimates with facts commonly observed and
well established by competent investigators. Hence the important question
of the supply, demand, and expenditure of water by forest vegetation must
hardly conceivable that so large a volume of aqueous vapor, in addition to
the supply from other sources, could be diffused through the ambient
atmosphere without manifesting its presence by ordinary hygrometrical
tests much more energetically than it has been proved to do, and in fact, the
observations recorded by Ebermayer show that though the RELATIVE
humidity of the atmosphere is considerably greater in the cooler
temperature of the wood, its ABSOLUTE humidity does not sensibly differ
from that of the air in open ground. [Footnote: Ebermeyer, Die
Physikalischen, Einwirkungen des Waldes, i., pp. 150 et seqq. It may be
well here to guard my readers against the common error which supposes
that a humid condition of the AIR is necessarily indicated by the presence
of fog or visible vapor. The air is rendered humid by containing
INVISIBLE vapor, and it becomes drier by the condensation of such vapor
into fog, composed of solid globules or of hollow vesicles of water—for it
is a disputed point whether the particles of fog are solid or vesicular. Hence,
though the ambient atmosphere may hold in suspension, in the form of fog,
water enough to obscure its transparency, and to produce the sensation of
moisture on the skin, the air, in which the finely divided water floats, may
be charged with even less than an average proportion of humidity.]
The daily discharge of a quantity of aqueous vapor corresponding to a
rain-fall of one inch and a fifth into the cool air of the forest would produce
a perpetual shower, or at least drizzle, unless, indeed, we suppose a rapidity
of absorption and condensation by the ground, and of transmission through
the soil to the roots and through them and the vessels of the tree to the
leaves, much greater than has been shown by direct observation.
Notwithstanding the high authority of Schleiden, therefore, it seems
impossible to reconcile his estimates with facts commonly observed and
well established by competent investigators. Hence the important question
of the supply, demand, and expenditure of water by forest vegetation must
Page 256
remain undecided, until it can be determined by something approaching to
satisfactory direct experiment. [Footnote: According to Cezanne, Surrell,
Etude sur les Torrents, 2e edition, ii., p. 100, experiments reported in the
Revue des Eaux et Forets for August, 1868, showed the evaporation from a
living tree to be "almost insignificant." Details are not given.]
Balance of Conflicting Influences of Forest on Atmospheric Heat and
Humidity.
We have shown that the forest, considered as dead matter, tends to
diminish the moisture of the air, by preventing the sun's rays from reaching
the ground and evaporating the water that falls upon the surface, and also
by spreading over the earth a spongy mantle which sucks up and retains the
humidity it receives from the atmosphere, while, at the same time, this
covering acts in the contrary direction by accumulating, in a reservoir not
wholly inaccessible to vaporizing influences, the water of precipitation
which might otherwise suddenly sink deep into the bowels of the earth, or
flow by superficial channels to other climatic regions. We now see that, as a
living organism, it tends, on the one hand, to diminish the humidity of the
air by sometimes absorbing moisture from it, and, on the other, to increase
that humidity by pouring out into the atmosphere, in a vaporous form, the
water it draws up through its roots. This last operation, at the same time,
lowers the temperature of the air in contact with or proximity to the wood,
by the same law as in other cases of the conversion of water into vapor.
As I have repeatedly said, we cannot measure the value of any one of
those elements of climatic disturbance, raising or lowering of temperature,
increase or diminution of humidity, nor can we say that in any one season,
any one year, or any one fixed cycle, however long or short, they balance
and compensate each other. They are sometimes, but certainly not always,
contemporaneous in their action, whether their tendency is in the same or in
satisfactory direct experiment. [Footnote: According to Cezanne, Surrell,
Etude sur les Torrents, 2e edition, ii., p. 100, experiments reported in the
Revue des Eaux et Forets for August, 1868, showed the evaporation from a
living tree to be "almost insignificant." Details are not given.]
Balance of Conflicting Influences of Forest on Atmospheric Heat and
Humidity.
We have shown that the forest, considered as dead matter, tends to
diminish the moisture of the air, by preventing the sun's rays from reaching
the ground and evaporating the water that falls upon the surface, and also
by spreading over the earth a spongy mantle which sucks up and retains the
humidity it receives from the atmosphere, while, at the same time, this
covering acts in the contrary direction by accumulating, in a reservoir not
wholly inaccessible to vaporizing influences, the water of precipitation
which might otherwise suddenly sink deep into the bowels of the earth, or
flow by superficial channels to other climatic regions. We now see that, as a
living organism, it tends, on the one hand, to diminish the humidity of the
air by sometimes absorbing moisture from it, and, on the other, to increase
that humidity by pouring out into the atmosphere, in a vaporous form, the
water it draws up through its roots. This last operation, at the same time,
lowers the temperature of the air in contact with or proximity to the wood,
by the same law as in other cases of the conversion of water into vapor.
As I have repeatedly said, we cannot measure the value of any one of
those elements of climatic disturbance, raising or lowering of temperature,
increase or diminution of humidity, nor can we say that in any one season,
any one year, or any one fixed cycle, however long or short, they balance
and compensate each other. They are sometimes, but certainly not always,
contemporaneous in their action, whether their tendency is in the same or in
Page 257
opposite directions, and, therefore, their influence is sometimes cumulative,
sometimes conflicting; but, upon the whole, their general effect is to
mitigate extremes of atmospheric heat and cold, moisture and drought. They
serve as equalizers of temperature and humidity, and it is highly probable
that, in analogy with most other works and workings of nature, they, at
certain or uncertain periods, restore the equilibrium which, whether as
lifeless masses or as living organisms, they may have temporarily disturbed.
[Footnote: There is one fact which I have nowhere seen noticed, but which
seems to me to have an important bearing on the question whether forests
tend to maintain an equilibrium between the various causes of hygroscopic
action, and consequently to keep the air within their precincts in an
approximately constant condition, so far as this meteorological element is
concerned. I refer to the absence of fog or visible vapor in thick woods in
full leaf, even when the air of the neighboring open grounds is so heavily
charged with condensed vapor as completely to obscure the sun. The
temperature of the atmosphere in the forest is not subject to so sudden and
extreme variations as that of cleared ground, but at the same time it is far
from constant, and so large a supply of vapor as is poured out by the foliage
of the trees could not fail to be sometimes condensed into fog by the same
causes as in the case of the adjacent meadows, which are often covered with
a dense mist while the forest-air remains clear, were there not some potent
counteracting influence always in action. This influence, I believe, is to be
found partly in the equalization of the temperature of the forest, and partly
in the balance between the humidity exhaled by the trees and that absorbed
and condensed invisibly by the earth.] When, therefore, man destroys these
natural harmonizors of climatic discords, he sacrifices an important
conservative power, though it is far from certain that he has thereby affected
the mean, however much he may have exaggerated the extremes of
atmospheric temperature and humidity, or, in other words, may have
sometimes conflicting; but, upon the whole, their general effect is to
mitigate extremes of atmospheric heat and cold, moisture and drought. They
serve as equalizers of temperature and humidity, and it is highly probable
that, in analogy with most other works and workings of nature, they, at
certain or uncertain periods, restore the equilibrium which, whether as
lifeless masses or as living organisms, they may have temporarily disturbed.
[Footnote: There is one fact which I have nowhere seen noticed, but which
seems to me to have an important bearing on the question whether forests
tend to maintain an equilibrium between the various causes of hygroscopic
action, and consequently to keep the air within their precincts in an
approximately constant condition, so far as this meteorological element is
concerned. I refer to the absence of fog or visible vapor in thick woods in
full leaf, even when the air of the neighboring open grounds is so heavily
charged with condensed vapor as completely to obscure the sun. The
temperature of the atmosphere in the forest is not subject to so sudden and
extreme variations as that of cleared ground, but at the same time it is far
from constant, and so large a supply of vapor as is poured out by the foliage
of the trees could not fail to be sometimes condensed into fog by the same
causes as in the case of the adjacent meadows, which are often covered with
a dense mist while the forest-air remains clear, were there not some potent
counteracting influence always in action. This influence, I believe, is to be
found partly in the equalization of the temperature of the forest, and partly
in the balance between the humidity exhaled by the trees and that absorbed
and condensed invisibly by the earth.] When, therefore, man destroys these
natural harmonizors of climatic discords, he sacrifices an important
conservative power, though it is far from certain that he has thereby affected
the mean, however much he may have exaggerated the extremes of
atmospheric temperature and humidity, or, in other words, may have
Page 258
increased the range and lengthened the scale of thermometric and
hygrometric variation.
Special Influence of Woods on Precipitation.
With the question of the action of forests upon temperature and upon
atmospheric humidity is intimately connected that of their influence upon
precipitation, which they may affect by increasing or diminishing the
warmth of the air and by absorbing or exhaling uncombincd gas and
aqueous vapor. The forest being a natural arrangement, the presumption is
that it exercises a conservative action, or at least a compensating one, and
consequently that its destruction must tend to produce pluviometrical
disturbances as well as thermometrical variations. And this is the opinion of
perhaps the greatest number of observers. Indeed, it is almost impossible to
suppose that, under certain conditions of time and place, the quantity and
the periods of rain should not depend, more or less, upon the presence or
absence of forests; and without insisting that the removal of the forest has
diminished the sum-total of snow and rain, we may well admit that it has
lessened the quantity which annually falls within particular limits. Various
theoretical considerations make this probable, the most obvious argument,
perhaps, being that drawn from the generally admitted fact, that the summer
and even the mean temperature of the forest is below that of the open
country in the same latitude. If the air in a wood is cooler than that around
it, it must reduce the temperature of the atmospheric stratum immediately
above it, and, of course, whenever a saturated current sweeps over it, it
must produce precipitation which would fall upon it, or at a greater or less
distance from it.
We must here take into the account a very important consideration. It is
not universally or even generally true, that the atmosphere returns its
hygrometric variation.
Special Influence of Woods on Precipitation.
With the question of the action of forests upon temperature and upon
atmospheric humidity is intimately connected that of their influence upon
precipitation, which they may affect by increasing or diminishing the
warmth of the air and by absorbing or exhaling uncombincd gas and
aqueous vapor. The forest being a natural arrangement, the presumption is
that it exercises a conservative action, or at least a compensating one, and
consequently that its destruction must tend to produce pluviometrical
disturbances as well as thermometrical variations. And this is the opinion of
perhaps the greatest number of observers. Indeed, it is almost impossible to
suppose that, under certain conditions of time and place, the quantity and
the periods of rain should not depend, more or less, upon the presence or
absence of forests; and without insisting that the removal of the forest has
diminished the sum-total of snow and rain, we may well admit that it has
lessened the quantity which annually falls within particular limits. Various
theoretical considerations make this probable, the most obvious argument,
perhaps, being that drawn from the generally admitted fact, that the summer
and even the mean temperature of the forest is below that of the open
country in the same latitude. If the air in a wood is cooler than that around
it, it must reduce the temperature of the atmospheric stratum immediately
above it, and, of course, whenever a saturated current sweeps over it, it
must produce precipitation which would fall upon it, or at a greater or less
distance from it.
We must here take into the account a very important consideration. It is
not universally or even generally true, that the atmosphere returns its
Page 259
condensed humidity to the local source from which it receives it. The air is
constantly in motion,
—howling tempests scour amain
From sea to land, from land to sea;
[Footnote: Und Sturme brausen um die Wette
Vom Meer aufs Land, vom Land aufs Meer.
Goethe, Faust, Song of the Archangels.]
and, therefore, it is always probable that the evaporation drawn up by the
atmosphere from a given river, or sea, or forest, or meadow, will be
discharged by precipitation, not at or near the point where it rose, but at a
distance of miles, leagues, or even degrees. The currents of the upper air are
invisible, and they leave behind them no landmark to record their track. We
know not whence they come, or whither they go. We have a certain rapidly
increasing acquaintance with the laws of general atmospheric motion, but of
the origin and limits, the beginning and end of that motion, as it manifests
itself at any particular time and place, we know nothing. We cannot say
where or when the vapor, exhaled to-day from the lake on which we float,
will be condensed and fall; whether it will waste itself on a barren desert,
refresh upland pastures, descend in snow on Alpine heights, or contribute to
swell a distant torrent which shall lay waste square miles of fertile corn-
land; nor do we know whether the rain which feeds our brooklets is due to
the transpiration from a neighboring forest, or to the evaporation from a far-
off sea. If, therefore, it were proved that the annual quantity of rain and dew
is now as great on the plains of Castile, for example, as it was when they
were covered with the native forest, it would by no means follow that those
woods did not augment the amount of precipitation elsewhere. The whole
problem of the pluviometrical influence of the forest, general or local, is so
exceedingly complex and difficult that it cannot, with our present means of
constantly in motion,
—howling tempests scour amain
From sea to land, from land to sea;
[Footnote: Und Sturme brausen um die Wette
Vom Meer aufs Land, vom Land aufs Meer.
Goethe, Faust, Song of the Archangels.]
and, therefore, it is always probable that the evaporation drawn up by the
atmosphere from a given river, or sea, or forest, or meadow, will be
discharged by precipitation, not at or near the point where it rose, but at a
distance of miles, leagues, or even degrees. The currents of the upper air are
invisible, and they leave behind them no landmark to record their track. We
know not whence they come, or whither they go. We have a certain rapidly
increasing acquaintance with the laws of general atmospheric motion, but of
the origin and limits, the beginning and end of that motion, as it manifests
itself at any particular time and place, we know nothing. We cannot say
where or when the vapor, exhaled to-day from the lake on which we float,
will be condensed and fall; whether it will waste itself on a barren desert,
refresh upland pastures, descend in snow on Alpine heights, or contribute to
swell a distant torrent which shall lay waste square miles of fertile corn-
land; nor do we know whether the rain which feeds our brooklets is due to
the transpiration from a neighboring forest, or to the evaporation from a far-
off sea. If, therefore, it were proved that the annual quantity of rain and dew
is now as great on the plains of Castile, for example, as it was when they
were covered with the native forest, it would by no means follow that those
woods did not augment the amount of precipitation elsewhere. The whole
problem of the pluviometrical influence of the forest, general or local, is so
exceedingly complex and difficult that it cannot, with our present means of
Page 260
knowledge, be decided upon a priori grounds. It must now be regarded as a
question of fact which would probably admit of scientific explanation if it
were once established what the actual fact is.
Unfortunately, the evidence is conflicting in tendency, and sometimes
equivocal in interpretation, but I believe that a majority of the foresters and
physicists who have studied the question are of opinion that in many, if not
in all cases, the destruction of the woods has been followed by a diminution
in the annual quantity of rain and dew. Indeed, it has long been a popularly
settled belief that vegetation and the condensation and fall of atmospheric
moisture are reciprocally necessary to each other, and even the poets sing of
Afric's barren sand,
Where nought can grow, because it raineth not,
And where no rain can fall to bless the land,
Because nought grows there.
[Footnote: Det golde Strog i Afrika,
Der Intet voxe kan, da ei det regner,
Og, omvendt, ingen Regn kan falde, da
Der Intet voxer.
Paudan-Muller, Adam Hamo, ii., 408.]
Before going further with the discussion, however, it is well to remark
that the comparative rarity or frequency of inundations in earlier or later
centuries is not necessarily, in most cases not probably, entitled to any
weight whatever, as a proof that more or less rain fell formerly than now;
because the accumulation of water in the channel of a river depends far less
upon the quantity of precipitation in its valley, than upon the rapidity with
which it is conducted, on or under the surface of the ground, to the central
artery that drains the basin. But this point will be more fully discussed in a
subsequent chapter.
question of fact which would probably admit of scientific explanation if it
were once established what the actual fact is.
Unfortunately, the evidence is conflicting in tendency, and sometimes
equivocal in interpretation, but I believe that a majority of the foresters and
physicists who have studied the question are of opinion that in many, if not
in all cases, the destruction of the woods has been followed by a diminution
in the annual quantity of rain and dew. Indeed, it has long been a popularly
settled belief that vegetation and the condensation and fall of atmospheric
moisture are reciprocally necessary to each other, and even the poets sing of
Afric's barren sand,
Where nought can grow, because it raineth not,
And where no rain can fall to bless the land,
Because nought grows there.
[Footnote: Det golde Strog i Afrika,
Der Intet voxe kan, da ei det regner,
Og, omvendt, ingen Regn kan falde, da
Der Intet voxer.
Paudan-Muller, Adam Hamo, ii., 408.]
Before going further with the discussion, however, it is well to remark
that the comparative rarity or frequency of inundations in earlier or later
centuries is not necessarily, in most cases not probably, entitled to any
weight whatever, as a proof that more or less rain fell formerly than now;
because the accumulation of water in the channel of a river depends far less
upon the quantity of precipitation in its valley, than upon the rapidity with
which it is conducted, on or under the surface of the ground, to the central
artery that drains the basin. But this point will be more fully discussed in a
subsequent chapter.
Page 261
In writers on the subject we are discussing, we find many positive
assertions about the diminution of rain in countries which have been
stripped of wood within the historic period, but these assertions very rarely
rest upon any other proof than the doubtful recollection of unscientific
observers, and I am unable to refer to a single instance where the records of
the rain-gauge, for a considerable period before and after the felling or
planting of extensive woods, can be appealed to in support of either side of
the question. The scientific reputation of many writers who have maintained
that precipitation has been diminished in particular localities by the
destruction of forests, or augmented by planting them, has led the public to
suppose that their assertions rested on sufficient proof. We cannot affirm
that in none of these cases did such proof exist, but I am not aware that it
has ever been produced. [Footnote: Among recent writers, Clave, Schacht,
Sir John F. W. Herschel, Hohenstein, Barth, Asbjornsen, Boussingault, and
others, maintain that forests tend to produce rain and clearings to diminish
it, and they refer to numerous facts of observation in support of this
doctrine; but in none of these does it appear that these observations are
supported by actual pluviometrical measure. So far as I know, the earliest
expression of the opinion that forests promote precipitation is that attributed
to Christopher Columbus, in the Historie del S. D. Fernando Colombo,
Venetia, 157l, cap. lviii., where it is said that the Admiral ascribed the daily
showers which fell in the West Indies about vespers to "the great forests and
trees of those countries," and remarked that the same effect was formerly
produced by the same cause in the Canary and Madeira Islands and in the
Azores, but that "now that the many woods and trees that covered them
have been felled, there are not produced so many clouds and rains as
before."
Mr. H. Harrisse, in his very learned and able critical essay, Fernand
Colomb, sa Vie et ses Oeuvres, Paris, 1872, has made it at least extremely
probable that the Historie is a spurious work. The compiler may have found
assertions about the diminution of rain in countries which have been
stripped of wood within the historic period, but these assertions very rarely
rest upon any other proof than the doubtful recollection of unscientific
observers, and I am unable to refer to a single instance where the records of
the rain-gauge, for a considerable period before and after the felling or
planting of extensive woods, can be appealed to in support of either side of
the question. The scientific reputation of many writers who have maintained
that precipitation has been diminished in particular localities by the
destruction of forests, or augmented by planting them, has led the public to
suppose that their assertions rested on sufficient proof. We cannot affirm
that in none of these cases did such proof exist, but I am not aware that it
has ever been produced. [Footnote: Among recent writers, Clave, Schacht,
Sir John F. W. Herschel, Hohenstein, Barth, Asbjornsen, Boussingault, and
others, maintain that forests tend to produce rain and clearings to diminish
it, and they refer to numerous facts of observation in support of this
doctrine; but in none of these does it appear that these observations are
supported by actual pluviometrical measure. So far as I know, the earliest
expression of the opinion that forests promote precipitation is that attributed
to Christopher Columbus, in the Historie del S. D. Fernando Colombo,
Venetia, 157l, cap. lviii., where it is said that the Admiral ascribed the daily
showers which fell in the West Indies about vespers to "the great forests and
trees of those countries," and remarked that the same effect was formerly
produced by the same cause in the Canary and Madeira Islands and in the
Azores, but that "now that the many woods and trees that covered them
have been felled, there are not produced so many clouds and rains as
before."
Mr. H. Harrisse, in his very learned and able critical essay, Fernand
Colomb, sa Vie et ses Oeuvres, Paris, 1872, has made it at least extremely
probable that the Historie is a spurious work. The compiler may have found
Page 262
this observation in some of the writings of Columbus now lost, but however
that may be, the fact, which Humboldt mentions in Cosmos with much
interest, still remains, that the doctrine in question was held, if not by the
great discoverer himself, at least by one of his pretended biographers, as
early as the year 1571.]
The effect of the forest on precipitation, then, is by no means free from
doubt, and we cannot positively affirm that the total annual quantity of rain
is even locally diminished or increased by the destruction of the woods,
though both theoretical considerations and the balance of testimony
strongly favor the opinion that more rain falls in wooded than in open
countries. One important conclusion, at least, upon the meteorological
influence of forests is certain and undisputed: the proposition, namely, that,
within their own limits, and near their own borders, they maintain a more
uniform degree of humidity in the atmosphere than is observed in cleared
grounds. Scarcely less can it be questioned that they tend to promote the
frequency of showers, and, if they do not augment the amount of
precipitation, they probably equalize its distribution through the different
seasons. [Footnote: The strongest direct evidence which I am able to refer
to in support of the proposition that the woods produce even a local
augmentation of precipitation is furnished by the observations of Mathieu,
sub-director of the Forest-School at Nancy. His pluviometrical
measurements, continued for three years, 1866-1868, show that during that
period the annual mean of rain-fall in the centre of the wooded district of
Cinq-Tranchees, at Belle Fontaine on the borders of the forest, and at
Amance, in an open cultivated territory in the same vicinity, was
respectively as the numbers 1,000, 957, and 853.
The alleged augmentation of rain-fall in Lower Egypt, in consequence of
large plantations by Mehemet Ali, is very frequently appealed to as a proof
of this influence of the forest, and this case has become a regular common-
that may be, the fact, which Humboldt mentions in Cosmos with much
interest, still remains, that the doctrine in question was held, if not by the
great discoverer himself, at least by one of his pretended biographers, as
early as the year 1571.]
The effect of the forest on precipitation, then, is by no means free from
doubt, and we cannot positively affirm that the total annual quantity of rain
is even locally diminished or increased by the destruction of the woods,
though both theoretical considerations and the balance of testimony
strongly favor the opinion that more rain falls in wooded than in open
countries. One important conclusion, at least, upon the meteorological
influence of forests is certain and undisputed: the proposition, namely, that,
within their own limits, and near their own borders, they maintain a more
uniform degree of humidity in the atmosphere than is observed in cleared
grounds. Scarcely less can it be questioned that they tend to promote the
frequency of showers, and, if they do not augment the amount of
precipitation, they probably equalize its distribution through the different
seasons. [Footnote: The strongest direct evidence which I am able to refer
to in support of the proposition that the woods produce even a local
augmentation of precipitation is furnished by the observations of Mathieu,
sub-director of the Forest-School at Nancy. His pluviometrical
measurements, continued for three years, 1866-1868, show that during that
period the annual mean of rain-fall in the centre of the wooded district of
Cinq-Tranchees, at Belle Fontaine on the borders of the forest, and at
Amance, in an open cultivated territory in the same vicinity, was
respectively as the numbers 1,000, 957, and 853.
The alleged augmentation of rain-fall in Lower Egypt, in consequence of
large plantations by Mehemet Ali, is very frequently appealed to as a proof
of this influence of the forest, and this case has become a regular common-
Page 263
place in all discussions of the question. It is, however, open to the same
objection as the alleged instances of the diminution of precipitation in
consequence of the felling of the forest.
This supposed increase in the frequency and quantity of rain in Lower
Egypt is, I think, an error, or at least not an established fact. I have heard it
disputed on the spot by intelligent Franks, whose residence in that country
began before the plantations of Mehemet Ali and Ibrahim Pacha, and I have
been assured by them that meterological observations, made at Alexandria
about the begiuning of this century, show an annual fall of rain as great as is
usual at this day. The mere fact that it did not rain during the French
occupation is not conclusive. Having experienced a gentle shower of nearly
twenty-four hours' duration in Upper Egypt, I inquired of the local governor
in relation to the frequency of this phenomenon, and was told by him that
not of drop of rain had fallen at that point for more than two years previous.
The belief in the increase of rain in Egypt rests almost entirely on the
observations of Marshal Marmont, and the evidence collected by him in
1836. His conclusions have been disputed, if not confuted, by Joinard and
others, and are probably erroneous. See Foissac, Meteorologie, German
translation, pp. 634-639.
It certainly sometimes rains briskly at Cairo, but evaporation is
exceedingly rapid in Egypt—as any one who ever saw a Fellah woman
wash a napkin in the Nile, and dry it by shaking it a few moments in the air,
can testify; and a heap of grain, wet a few inches below the surface, would
probably dry again without injury. At any rate, the Egyptian Government
often has vast quantities of wheat stored at Boulak in uncovered yards
through the winter, though it must be admitted that the slovenliness and
want of foresight in Oriental life, public and private, are such that we
objection as the alleged instances of the diminution of precipitation in
consequence of the felling of the forest.
This supposed increase in the frequency and quantity of rain in Lower
Egypt is, I think, an error, or at least not an established fact. I have heard it
disputed on the spot by intelligent Franks, whose residence in that country
began before the plantations of Mehemet Ali and Ibrahim Pacha, and I have
been assured by them that meterological observations, made at Alexandria
about the begiuning of this century, show an annual fall of rain as great as is
usual at this day. The mere fact that it did not rain during the French
occupation is not conclusive. Having experienced a gentle shower of nearly
twenty-four hours' duration in Upper Egypt, I inquired of the local governor
in relation to the frequency of this phenomenon, and was told by him that
not of drop of rain had fallen at that point for more than two years previous.
The belief in the increase of rain in Egypt rests almost entirely on the
observations of Marshal Marmont, and the evidence collected by him in
1836. His conclusions have been disputed, if not confuted, by Joinard and
others, and are probably erroneous. See Foissac, Meteorologie, German
translation, pp. 634-639.
It certainly sometimes rains briskly at Cairo, but evaporation is
exceedingly rapid in Egypt—as any one who ever saw a Fellah woman
wash a napkin in the Nile, and dry it by shaking it a few moments in the air,
can testify; and a heap of grain, wet a few inches below the surface, would
probably dry again without injury. At any rate, the Egyptian Government
often has vast quantities of wheat stored at Boulak in uncovered yards
through the winter, though it must be admitted that the slovenliness and
want of foresight in Oriental life, public and private, are such that we
Page 264
cannot infer the safety of any practice followed in the East merely from its
long continuance.
Grain, however, may be long kept in the open air in climates much less
dry than that of Egypt, without injury, except to the superficial layers; for
moisture does not penetrate to a great depth in a heap of grain once well
dried and kept well aired. When Louis IX. was making his preparations for
his campaign in the East, he had large quantities of wine and grain
purchased in the Island of Cyprus, and stored up for two years to await his
arrival. "When we were come to Cyprus," says Joinville, Histoire de Saint
Louis, Section 72, 73, "we found there greate foison of the Kynge's
purveyance. . . The wheate and the barley they had piled up in greate heapes
in the feeldes, and to looke vpon, they were like vnto mountaynes; for the
raine, the whyche hadde beaten vpon the wheate now a longe whyle, had
made it to sproute on the toppe, so that it seemed as greene grasse. And
whanne they were mynded to carrie it to Egypte, they brake that sod of
greene herbe, and dyd finde under the same the wheate and the barley, as
freshe as yf menne hadde but nowe thrashed it."]
Total Climatic Influence of the Forest.
Aside from the question of local disturbances and their compensations, it
does not seem probable that the forests sensibly affect the general mean of
atmospheric temperature of the globe, or the total quantity of precipitation,
or even that they had this influence when their extent was vastly greater
than at present. The waters cover about three-fourths of the face of the
earth, and if we deduct the frozen zones, the peaks and crests of lofty
mountains and their craggy slopes, the Sahara and other great African and
Asiatic deserts, and all such other portions of the solid surface as are
permanently unfit for the growth of wood, we shall find that probably not
one-tenth of the total superficies of our planet was ever, at any one time in
long continuance.
Grain, however, may be long kept in the open air in climates much less
dry than that of Egypt, without injury, except to the superficial layers; for
moisture does not penetrate to a great depth in a heap of grain once well
dried and kept well aired. When Louis IX. was making his preparations for
his campaign in the East, he had large quantities of wine and grain
purchased in the Island of Cyprus, and stored up for two years to await his
arrival. "When we were come to Cyprus," says Joinville, Histoire de Saint
Louis, Section 72, 73, "we found there greate foison of the Kynge's
purveyance. . . The wheate and the barley they had piled up in greate heapes
in the feeldes, and to looke vpon, they were like vnto mountaynes; for the
raine, the whyche hadde beaten vpon the wheate now a longe whyle, had
made it to sproute on the toppe, so that it seemed as greene grasse. And
whanne they were mynded to carrie it to Egypte, they brake that sod of
greene herbe, and dyd finde under the same the wheate and the barley, as
freshe as yf menne hadde but nowe thrashed it."]
Total Climatic Influence of the Forest.
Aside from the question of local disturbances and their compensations, it
does not seem probable that the forests sensibly affect the general mean of
atmospheric temperature of the globe, or the total quantity of precipitation,
or even that they had this influence when their extent was vastly greater
than at present. The waters cover about three-fourths of the face of the
earth, and if we deduct the frozen zones, the peaks and crests of lofty
mountains and their craggy slopes, the Sahara and other great African and
Asiatic deserts, and all such other portions of the solid surface as are
permanently unfit for the growth of wood, we shall find that probably not
one-tenth of the total superficies of our planet was ever, at any one time in
Page 265
the present geological period, covered with forests. Besides this, the
distribution of forest land, of desert, and of water, is such as to reduce the
possible influence of the woods to a low expression; for the forests are, in
large proportion, situated in cold or temperate climates, where the action of
the sun is comparatively feeble both in elevating temperature and in
promoting evaporation; while, in the torrid zone, the desert and the sea—the
latter of which always presents an evaporable surface—enormously
preponderate. It is, upon the whole, not probable that so small an extent of
forest, so situated, could produce a sensible influence on the general climate
of the globe, though it might appreciably affect the local action of all
climatic elements. The total annual amount of solar heat absorbed and
radiated by the earth, and the sum of terrestrial evaporation and atmospheric
precipitation, must be supposed constant; but the distribution of heat and of
humidity is exposed to disturbance in both time and place by a multitude of
local causes, among which the presence or absence of the forest is doubtless
one.
So far as we are able to sum up the results, it would appear that, in
countries in the temperate zone still chiefly covered with wood, the
summers would be cooler, moister, shorter, the winters milder, drier, longer,
than in the same regions after the removal of the forest, and that the
condensation and precipitation of atmospheric moisture would be, if not
greater in total quantity, more frequent and less violent in discharge. The
slender historical evidence we possess seems to point to the same
conclusion, though there is some conflict of testimony and of opinion on
this point.
Among the many causes which, as we have seen, tend to influence the
general result, the mechanical action of the forest, if not more important, is
certainly more obvious and direct than the immediate effects of its organic
processes. The felling of the woods involves the sacrifice of a valuable
distribution of forest land, of desert, and of water, is such as to reduce the
possible influence of the woods to a low expression; for the forests are, in
large proportion, situated in cold or temperate climates, where the action of
the sun is comparatively feeble both in elevating temperature and in
promoting evaporation; while, in the torrid zone, the desert and the sea—the
latter of which always presents an evaporable surface—enormously
preponderate. It is, upon the whole, not probable that so small an extent of
forest, so situated, could produce a sensible influence on the general climate
of the globe, though it might appreciably affect the local action of all
climatic elements. The total annual amount of solar heat absorbed and
radiated by the earth, and the sum of terrestrial evaporation and atmospheric
precipitation, must be supposed constant; but the distribution of heat and of
humidity is exposed to disturbance in both time and place by a multitude of
local causes, among which the presence or absence of the forest is doubtless
one.
So far as we are able to sum up the results, it would appear that, in
countries in the temperate zone still chiefly covered with wood, the
summers would be cooler, moister, shorter, the winters milder, drier, longer,
than in the same regions after the removal of the forest, and that the
condensation and precipitation of atmospheric moisture would be, if not
greater in total quantity, more frequent and less violent in discharge. The
slender historical evidence we possess seems to point to the same
conclusion, though there is some conflict of testimony and of opinion on
this point.
Among the many causes which, as we have seen, tend to influence the
general result, the mechanical action of the forest, if not more important, is
certainly more obvious and direct than the immediate effects of its organic
processes. The felling of the woods involves the sacrifice of a valuable
Page 266
protection against the violence of chilling winds and the loss of the shelter
afforded to the ground by the thick coating of leaves which the forest sheds
upon it and by the snow which the woods prevent from blowing away, or
from melting in the brief thaws of winter. I have already remarked that bare
ground freezes much deeper than that which is covered by beds of leaves,
and when the earth is thickly coated with snow, the strata frozen before it
fell begin to thaw. It is not uncommon to find the ground in the woods,
where the snow lies two or three feet deep, entirely free from frost, when
the atmospheric temperature has been for several weeks below the freezing-
point, and for some days even below the zero of Fahrenheit. When the
ground is cleared and brought under cultivation, the leaves are ploughed
into the soil and decomposed, and the snow, especially upon knolls and
eminences, is blown off, or perhaps half thawed, several times during the
winter. The water from the melting snow runs into the depressions, and
when, after a day or two of warm sunshine or tepid rain, the cold returns, it
is consolidated to ice, and the bared ridges and swells of earth are deeply
frozen. [Footnote: I have seen, in Northern New England, the surface of the
open ground frozen to the depth of twenty-two inches, in the month of
November, when in the forest-earth no frost was discoverable; and later in
the winter, I have known an exposed sand-knoll to remain frozen six feet
deep, after the ground in the woods was completely thawed.] It requires
many days of mild weather to raise the temperature of soil in this condition,
and of the air in contact with it, to that of the earth in the forests of the same
climatic region. Flora is already plaiting her sylvan wreath before the corn-
flowers which are to deck the garland of Ceres have waked from their
winter's sleep; and it is probably not a popular error to believe that, where
man has substituted his artificial crops for the spontaneous harvest of
nature, spring delays her coming. [Footnote: The conclusion arrived at by
Noah Webster, in his very learned and able paper on the supposed change in
the temperature of winter, read before the Connecticut Academy of Arts and
afforded to the ground by the thick coating of leaves which the forest sheds
upon it and by the snow which the woods prevent from blowing away, or
from melting in the brief thaws of winter. I have already remarked that bare
ground freezes much deeper than that which is covered by beds of leaves,
and when the earth is thickly coated with snow, the strata frozen before it
fell begin to thaw. It is not uncommon to find the ground in the woods,
where the snow lies two or three feet deep, entirely free from frost, when
the atmospheric temperature has been for several weeks below the freezing-
point, and for some days even below the zero of Fahrenheit. When the
ground is cleared and brought under cultivation, the leaves are ploughed
into the soil and decomposed, and the snow, especially upon knolls and
eminences, is blown off, or perhaps half thawed, several times during the
winter. The water from the melting snow runs into the depressions, and
when, after a day or two of warm sunshine or tepid rain, the cold returns, it
is consolidated to ice, and the bared ridges and swells of earth are deeply
frozen. [Footnote: I have seen, in Northern New England, the surface of the
open ground frozen to the depth of twenty-two inches, in the month of
November, when in the forest-earth no frost was discoverable; and later in
the winter, I have known an exposed sand-knoll to remain frozen six feet
deep, after the ground in the woods was completely thawed.] It requires
many days of mild weather to raise the temperature of soil in this condition,
and of the air in contact with it, to that of the earth in the forests of the same
climatic region. Flora is already plaiting her sylvan wreath before the corn-
flowers which are to deck the garland of Ceres have waked from their
winter's sleep; and it is probably not a popular error to believe that, where
man has substituted his artificial crops for the spontaneous harvest of
nature, spring delays her coming. [Footnote: The conclusion arrived at by
Noah Webster, in his very learned and able paper on the supposed change in
the temperature of winter, read before the Connecticut Academy of Arts and
Page 267
Sciences in 1799, was as follows: "From a careful comparison of these
facts, it appears that the weather, in modern winters, in the United States, is
more inconstant than when the earth was covered with woods, at the first
settlement of Europeans in the country; that the warm weather of autumn
extends further into the winter months, and the cold weather of winter and
spring encroaches upon the summer; that, the wind being more variable,
snow is less permanent, and perhaps the same remark may be applicable to
the ice of the rivers. These effects seem to result necessarily from the
greater quantity of heat accumulated in the earth in summer since the
ground has been cleared of wood and exposed to the rays of the sun, and to
the greater depth of frost in the earth in winter by the exposure of its
uncovered surface to the cold atmosphere."—Collection of Papers by Noah
Webster, p. 162.]
There are, in the constitution and action of the forest, many forces,
organic and inorganic, which unquestionably tend powerfully to produce
meteorological effects, and it may, therefore, be assumed as certain that
they must and do produce such effects, UNLESS they compensate and
balance each other, and herein lies the difficulty of solving the question. To
some of these elements late observations give a new importance. For
example, the exhalation of aqueous vapor by plants is now believed to be
much greater, and the absorption of aqueous vapor by them much less, than
was formerly supposed, and Tyndall's views on the relations of vapor to
atmospheric heat give immense value to this factor in the problem. In like
manner the low temperature of the surface of snow and the comparatively
high temperature of its lower strata, and its consequent action on the soil
beneath, and the great condensation of moisture by snow, are facts which
seem to show that the forest, by protecting great surfaces of snow from
melting, must inevitably exercise a great climatic influence. If to these
influences we add the mechanical action of the woods in obstructing
currents of wind, and diminishing the evaporation and refrigeration which
facts, it appears that the weather, in modern winters, in the United States, is
more inconstant than when the earth was covered with woods, at the first
settlement of Europeans in the country; that the warm weather of autumn
extends further into the winter months, and the cold weather of winter and
spring encroaches upon the summer; that, the wind being more variable,
snow is less permanent, and perhaps the same remark may be applicable to
the ice of the rivers. These effects seem to result necessarily from the
greater quantity of heat accumulated in the earth in summer since the
ground has been cleared of wood and exposed to the rays of the sun, and to
the greater depth of frost in the earth in winter by the exposure of its
uncovered surface to the cold atmosphere."—Collection of Papers by Noah
Webster, p. 162.]
There are, in the constitution and action of the forest, many forces,
organic and inorganic, which unquestionably tend powerfully to produce
meteorological effects, and it may, therefore, be assumed as certain that
they must and do produce such effects, UNLESS they compensate and
balance each other, and herein lies the difficulty of solving the question. To
some of these elements late observations give a new importance. For
example, the exhalation of aqueous vapor by plants is now believed to be
much greater, and the absorption of aqueous vapor by them much less, than
was formerly supposed, and Tyndall's views on the relations of vapor to
atmospheric heat give immense value to this factor in the problem. In like
manner the low temperature of the surface of snow and the comparatively
high temperature of its lower strata, and its consequent action on the soil
beneath, and the great condensation of moisture by snow, are facts which
seem to show that the forest, by protecting great surfaces of snow from
melting, must inevitably exercise a great climatic influence. If to these
influences we add the mechanical action of the woods in obstructing
currents of wind, and diminishing the evaporation and refrigeration which
Page 268
such currents produce, we have an accumulation of forces which MUST
manifest great climatic effects, unless—which is not proved and cannot be
presumed—they neutralize each other. These are points hitherto little
considered in the discussion, and it seems difficult to deny that as a question
of ARGUMENT, the probabilities are strongly in favor of the
meteorological influence of the woods. The EVIDENCE, indeed, is not
satisfactory, or, to speak more accurately, it is non-existent, for there really
is next to no trustworthy proof on the subject, but it appears to me a case
where the burden of proof must be taken by those who maintain that, as a
meteorological agent, the forest is inert.
The question of a change in the climate of the Northern American States
is examined in the able Meteorological Report of Mr. Draper, Director of
the New York Central Park Observatory, for 1871. The result arrived at by
Mr. Draper is, that there is no satisfactory evidence of a diminution in the
rainfall, or of any other climatic change in the winter season, in
consequence of clearing of the forests or other human action. The proof
from meteorological registers is certainly insufficient to establish the fact of
a change of climate, but, on the other hand, it is equally insufficient to
establish the contrary. Meteorological stations are too few, their
observations, in many cases, extend over a very short period, and, for
reasons I have already given, the great majority of their records are entitled
to little or no confidence. [Footnote: Since these pages were written, the
subject of forest meteorology has received the most important contribution
ever made to it, in several series of observations at numerous stations in
Bavaria, from the year 1866 to 1871, published by Ebermayer, at
Aschaffenburg, in 1873, under the title: Die Physikalischen Einwirkungen
des Waldes auf Luft und Boden, und seine Klimatologische und
Hygienische Bedeutung. I. Band. So far as observations of only five years'
duration can prove anything, the following propositions, not to speak of
manifest great climatic effects, unless—which is not proved and cannot be
presumed—they neutralize each other. These are points hitherto little
considered in the discussion, and it seems difficult to deny that as a question
of ARGUMENT, the probabilities are strongly in favor of the
meteorological influence of the woods. The EVIDENCE, indeed, is not
satisfactory, or, to speak more accurately, it is non-existent, for there really
is next to no trustworthy proof on the subject, but it appears to me a case
where the burden of proof must be taken by those who maintain that, as a
meteorological agent, the forest is inert.
The question of a change in the climate of the Northern American States
is examined in the able Meteorological Report of Mr. Draper, Director of
the New York Central Park Observatory, for 1871. The result arrived at by
Mr. Draper is, that there is no satisfactory evidence of a diminution in the
rainfall, or of any other climatic change in the winter season, in
consequence of clearing of the forests or other human action. The proof
from meteorological registers is certainly insufficient to establish the fact of
a change of climate, but, on the other hand, it is equally insufficient to
establish the contrary. Meteorological stations are too few, their
observations, in many cases, extend over a very short period, and, for
reasons I have already given, the great majority of their records are entitled
to little or no confidence. [Footnote: Since these pages were written, the
subject of forest meteorology has received the most important contribution
ever made to it, in several series of observations at numerous stations in
Bavaria, from the year 1866 to 1871, published by Ebermayer, at
Aschaffenburg, in 1873, under the title: Die Physikalischen Einwirkungen
des Waldes auf Luft und Boden, und seine Klimatologische und
Hygienische Bedeutung. I. Band. So far as observations of only five years'
duration can prove anything, the following propositions, not to speak of
Page 269
many collateral and subsidiary conclusions, seem to be established, at least
for the localities where the observations were made:
1. The yearly mean temperature of wooded soils, at all depths, is lower
than that of open grounds, p. 85.
This conclusion, it may be remarked, is of doubtful applicability in
regions of excessive climate like the Northern United States and Canada,
where the snow keeps the temperature of the soil in the forest above the
freezing-point, for a large part and sometimes the whole of the winter, while
in unwooded ground the earth remains deeply frozen.
2. The yearly mean atmospheric temperature, other things being equal, is
lower in the forest than in cleared grounds, p. 84.
3. Climates become excessive in consequence of extensive clearings, p.
117.
4. The ABSOLUTE humidity of the air in the forest is about the same as
in open ground, while the RELATIVE humidity is greater in the former than
in the latter case, on account of the lower temperature of the atmosphere in
the wood, p. 150.
5. The evaporation from an exposed surface of water in the forest is
sixty-four per cent. less than in unwooded grounds, pp. 159,161.
6. About twenty-six per cent. of the precipitation is interrupted and
prevented from reaching the ground by the foliage and branches of forest
trees, p. 194.
7. In the interior of thick woods, the evaporation from water and from
earth is much less than the precipitation, p. 210.
for the localities where the observations were made:
1. The yearly mean temperature of wooded soils, at all depths, is lower
than that of open grounds, p. 85.
This conclusion, it may be remarked, is of doubtful applicability in
regions of excessive climate like the Northern United States and Canada,
where the snow keeps the temperature of the soil in the forest above the
freezing-point, for a large part and sometimes the whole of the winter, while
in unwooded ground the earth remains deeply frozen.
2. The yearly mean atmospheric temperature, other things being equal, is
lower in the forest than in cleared grounds, p. 84.
3. Climates become excessive in consequence of extensive clearings, p.
117.
4. The ABSOLUTE humidity of the air in the forest is about the same as
in open ground, while the RELATIVE humidity is greater in the former than
in the latter case, on account of the lower temperature of the atmosphere in
the wood, p. 150.
5. The evaporation from an exposed surface of water in the forest is
sixty-four per cent. less than in unwooded grounds, pp. 159,161.
6. About twenty-six per cent. of the precipitation is interrupted and
prevented from reaching the ground by the foliage and branches of forest
trees, p. 194.
7. In the interior of thick woods, the evaporation from water and from
earth is much less than the precipitation, p. 210.
Page 270
8. The loss of the water of precipitation intercepted by the trees in the
forest is compensated by the smaller evaporation from the ground, p. 219.
9. In elevated regions and during the summer half of the year, woods tend
to increase the precipitation, p. 202.]
Influence of the Forest on the Humidity of the Soil.
I have hitherto confined myself to the influence of the forest on
meteorological conditions, a subject, as has been seen, full of difficulty and
uncertainty. Its comparative effects on the temperature, the humidity, the
texture and consistence, the configuration and distribution of the mould or
arable soil, and, very often, of the mineral strata below, and on the
permanence and regularity of springs and greater superficial water-courses,
are much less disputable as well as more easily estimated and more
important, than its possible value as a cause of strictly climatic equilibrium
or disturbance.
The action of the forest on the earth is chiefly mechanical, but the organic
process of absorption of moisture by its roots affects the quantity of water
contained in the vegetable mould and in the mineral strata near the surface,
and, consequently, the consistency of the soil. In treating of the effects of
trees on the moisture of the atmosphere, I have said that the forest, by
interposing a canopy between the sky and the ground, and by covering the
surface with a thick mantle of fallen leaves, at once obstructed insulation
and prevented the radiation of heat from the earth. These influences go far
to balance each other; but familiar observation shows that, in summer, the
forest-soil is not raised to so high a temperature as open grounds exposed to
irradiation. For this reason, and in consequence of the mechanical resistance
opposed by the bed of dead leaves to the escape of moisture, we should
expect that, except after recent rains, the superficial strata of woodland-soil
forest is compensated by the smaller evaporation from the ground, p. 219.
9. In elevated regions and during the summer half of the year, woods tend
to increase the precipitation, p. 202.]
Influence of the Forest on the Humidity of the Soil.
I have hitherto confined myself to the influence of the forest on
meteorological conditions, a subject, as has been seen, full of difficulty and
uncertainty. Its comparative effects on the temperature, the humidity, the
texture and consistence, the configuration and distribution of the mould or
arable soil, and, very often, of the mineral strata below, and on the
permanence and regularity of springs and greater superficial water-courses,
are much less disputable as well as more easily estimated and more
important, than its possible value as a cause of strictly climatic equilibrium
or disturbance.
The action of the forest on the earth is chiefly mechanical, but the organic
process of absorption of moisture by its roots affects the quantity of water
contained in the vegetable mould and in the mineral strata near the surface,
and, consequently, the consistency of the soil. In treating of the effects of
trees on the moisture of the atmosphere, I have said that the forest, by
interposing a canopy between the sky and the ground, and by covering the
surface with a thick mantle of fallen leaves, at once obstructed insulation
and prevented the radiation of heat from the earth. These influences go far
to balance each other; but familiar observation shows that, in summer, the
forest-soil is not raised to so high a temperature as open grounds exposed to
irradiation. For this reason, and in consequence of the mechanical resistance
opposed by the bed of dead leaves to the escape of moisture, we should
expect that, except after recent rains, the superficial strata of woodland-soil
Page 271
would be more humid than that of cleared land. This agrees with
experience. The soil of the natural forest is always moist, except in the
extremest droughts, and it is exceedingly rare that a primitive wood suffers
from want of humidity. How far this accumulation of water affects the
condition of neighboring grounds by lateral infiltration, we do not know,
but we shall see, in a subsequent chapter, that water is conveyed to great
distances by this process, and we may hence infer that the influence in
question is an important one.
It is undoubtedly true that loose soils, stripped of vegetation and broken
up by the plough or other processes of cultivation, may, until again carpeted
by grasses or other plants, absorb more rain and snow-water than when they
were covered by a natural growth; but it is also true that the evaporation
from such soils is augmented in a still greater proportion. Rain scarcely
penetrates beneath the sod of grass-ground, but runs off over the surface;
and after the heaviest showers a ploughed field will often be dried by
evaporation before the water can be carried off by infiltration, while the soil
of a neighboring grove will remain half saturated for weeks together. Sandy
soils frequently rest on a tenacious subsoil, at a moderate depth, as is
usually seen in the pine plains of the United States, where pools of rain-
water collect in slight depressions on the surface of earth the upper stratum
of which is as porous as a sponge. In the open grounds such pools are very
soon dried up by the sun and wind; in the woods they remain unevaporated
long enough for the water to diffuse itself laterally until it finds, in the
subsoil, crevices through which it may escape, or slopes which it may
follow to their outcrop or descend along them to lower strata.
Drainage by Roots of Trees.
Becquerel notices a special function of the forest to which I have already
alluded, but to which sufficient importance has not, until very recently, been
experience. The soil of the natural forest is always moist, except in the
extremest droughts, and it is exceedingly rare that a primitive wood suffers
from want of humidity. How far this accumulation of water affects the
condition of neighboring grounds by lateral infiltration, we do not know,
but we shall see, in a subsequent chapter, that water is conveyed to great
distances by this process, and we may hence infer that the influence in
question is an important one.
It is undoubtedly true that loose soils, stripped of vegetation and broken
up by the plough or other processes of cultivation, may, until again carpeted
by grasses or other plants, absorb more rain and snow-water than when they
were covered by a natural growth; but it is also true that the evaporation
from such soils is augmented in a still greater proportion. Rain scarcely
penetrates beneath the sod of grass-ground, but runs off over the surface;
and after the heaviest showers a ploughed field will often be dried by
evaporation before the water can be carried off by infiltration, while the soil
of a neighboring grove will remain half saturated for weeks together. Sandy
soils frequently rest on a tenacious subsoil, at a moderate depth, as is
usually seen in the pine plains of the United States, where pools of rain-
water collect in slight depressions on the surface of earth the upper stratum
of which is as porous as a sponge. In the open grounds such pools are very
soon dried up by the sun and wind; in the woods they remain unevaporated
long enough for the water to diffuse itself laterally until it finds, in the
subsoil, crevices through which it may escape, or slopes which it may
follow to their outcrop or descend along them to lower strata.
Drainage by Roots of Trees.
Becquerel notices a special function of the forest to which I have already
alluded, but to which sufficient importance has not, until very recently, been
Page 272
generally ascribed. I refer to the mechanical action of the roots as
conductors of the superfluous humidity of the superficial earth to lower
strata. The roots of trees often penetrate through subsoil almost impervious
to water, and in such cases the moisture, which would otherwise remain
above the subsoil and convert the surface-earth into a bog, follows the roots
downwards and escapes into more porous strata or is received by
subterranean canals or reservoirs. [Footnote: "The roots of vegetables," says
d'Hericourt, "perform the office of draining in a manner analogous to that
artificially practised in parts of Holland and the British islands. This method
consists in driving deeply down into the soil several hundred stakes to the
acre; the water filters down along the stakes, and in some cases as favorable
results have been obtained by this means as by horizontal drains."-Annales
Forestieres, 1837, p. 312.] When the forest is felled, the roots perish and
decay, the orifices opened by them are soon obstructed, and the water, after
having saturated the vegetable earth, stagnates on the surface and
transforms it into ponds and morasses. Thus in La Brenne, a tract of
200,000 acres resting on an impermeable subsoil of argillaceous earth,
which ten centuries ago was covered with forests interspersed with fertile
and salubrious meadows and pastures, has been converted, by the
destruction of the woods, into a vast expanse of pestilential pools and
marshes. In Sologne the same cause has withdrawn from cultivation and
human inhabitation not less than 1,100,000 acres of ground once well
wooded, well drained, and productive.
It is an important observation that the desiccating action of trees, by way
of drainage or external conduction by the roots, is greater in the artificial
than in the natural wood, and hence that the surface of the ground in the
former is not characterized by that approach to a state of saturation which it
so generally manifests in the latter. In the spontaneous wood, the leaves,
fruits, bark, branches, and dead trunks, by their decayed material and by the
conversion of rock into loose earth through the solvent power of the gases
conductors of the superfluous humidity of the superficial earth to lower
strata. The roots of trees often penetrate through subsoil almost impervious
to water, and in such cases the moisture, which would otherwise remain
above the subsoil and convert the surface-earth into a bog, follows the roots
downwards and escapes into more porous strata or is received by
subterranean canals or reservoirs. [Footnote: "The roots of vegetables," says
d'Hericourt, "perform the office of draining in a manner analogous to that
artificially practised in parts of Holland and the British islands. This method
consists in driving deeply down into the soil several hundred stakes to the
acre; the water filters down along the stakes, and in some cases as favorable
results have been obtained by this means as by horizontal drains."-Annales
Forestieres, 1837, p. 312.] When the forest is felled, the roots perish and
decay, the orifices opened by them are soon obstructed, and the water, after
having saturated the vegetable earth, stagnates on the surface and
transforms it into ponds and morasses. Thus in La Brenne, a tract of
200,000 acres resting on an impermeable subsoil of argillaceous earth,
which ten centuries ago was covered with forests interspersed with fertile
and salubrious meadows and pastures, has been converted, by the
destruction of the woods, into a vast expanse of pestilential pools and
marshes. In Sologne the same cause has withdrawn from cultivation and
human inhabitation not less than 1,100,000 acres of ground once well
wooded, well drained, and productive.
It is an important observation that the desiccating action of trees, by way
of drainage or external conduction by the roots, is greater in the artificial
than in the natural wood, and hence that the surface of the ground in the
former is not characterized by that approach to a state of saturation which it
so generally manifests in the latter. In the spontaneous wood, the leaves,
fruits, bark, branches, and dead trunks, by their decayed material and by the
conversion of rock into loose earth through the solvent power of the gases
Page 273
they develop in decomposition, cover the ground with an easily penetrable
stratum of mixed vegetable and mineral matter extremely favorable to the
growth of trees, and at the same time too retentive of moisture to part with
it readily to the capillary attraction of the roots.
The trees, finding abundant nutriment near the surface, and so sheltered
against the action of the wind by each other as not to need the support of
deep and firmly fixed stays, send their roots but a moderate distance
downwards, and indeed often spread them out like a horizontal network
almost on the surface of the ground. In the artificial wood, on the contrary,
the spaces between the trees are greater; they are obliged to send their roots
deeper both for mechanical support and in search of nutriment, and they
consequently serve much more effectually as conduits for perpendicular
drainage.
It is only under special circumstances, however, that this function of the
forest is so essential a conservative agent as in the two cases just cited. In a
champaign region insufficiently provided with natural channels for the
discharge of the waters, and with a subsoil which, though penetrable by the
roots of trees, is otherwise impervious to water, it is of cardinal importance;
but though trees everywhere tend to carry off the moisture of the superficial
strata by this mode of conduction, yet the precise condition of soil which I
have described is not of sufficiently frequent occurrence to have drawn
much attention to this office of the wood. In fact, in most soils, there are
counteracting influences which neutralize, more or less effectually, the
desiccative action of roots, and in general it is as true as it was in Seneca's
time, that "the shadiest grounds are the moistest." [Footnote: Seneca,
Questiones Naturales, iii. 11, 2.]
It is always observed in the American States, that clearing the ground not
only causes running springs to disappear, but dries up the stagnant pools
stratum of mixed vegetable and mineral matter extremely favorable to the
growth of trees, and at the same time too retentive of moisture to part with
it readily to the capillary attraction of the roots.
The trees, finding abundant nutriment near the surface, and so sheltered
against the action of the wind by each other as not to need the support of
deep and firmly fixed stays, send their roots but a moderate distance
downwards, and indeed often spread them out like a horizontal network
almost on the surface of the ground. In the artificial wood, on the contrary,
the spaces between the trees are greater; they are obliged to send their roots
deeper both for mechanical support and in search of nutriment, and they
consequently serve much more effectually as conduits for perpendicular
drainage.
It is only under special circumstances, however, that this function of the
forest is so essential a conservative agent as in the two cases just cited. In a
champaign region insufficiently provided with natural channels for the
discharge of the waters, and with a subsoil which, though penetrable by the
roots of trees, is otherwise impervious to water, it is of cardinal importance;
but though trees everywhere tend to carry off the moisture of the superficial
strata by this mode of conduction, yet the precise condition of soil which I
have described is not of sufficiently frequent occurrence to have drawn
much attention to this office of the wood. In fact, in most soils, there are
counteracting influences which neutralize, more or less effectually, the
desiccative action of roots, and in general it is as true as it was in Seneca's
time, that "the shadiest grounds are the moistest." [Footnote: Seneca,
Questiones Naturales, iii. 11, 2.]
It is always observed in the American States, that clearing the ground not
only causes running springs to disappear, but dries up the stagnant pools
Page 274
and the spongy soils of the low grounds. The first roads in those States ran
along the ridges, when practicable, because there only was the earth dry
enough to allow of their construction, and, for the same reason, the cabins
of the first settlers were perched upon the hills. As the forests have been
from time to time removed, and the face of the earth laid open to the air and
sun, the moisture has been evaporated, and the removal of the highways and
of human habitations from the bleak hills to the sheltered valleys, is one of
the most agreeable among the many improvements which later generations
have witnessed in the interior of the Northern States. [Footnote: The Tuscan
poet Ginati, who hod certainly had little opportunity of observing primitive
conditions of nature and of man, was aware that such must have been the
course of things in new countries. "You know," says he in a letter to a
friend, "that the hills were first occupied by man, because stagnant waters,
and afterwards continual wars, excluded men from the plains. But when
tranquillity was established and means provided for the discharge of the
waters, the low grounds were soon covered with human habitations."—
Letters, Firenze, 1864, p. 98.]
Recent observers in France affirm that evergreen trees exercise a special
desiccating action on the soil, and cases are cited where large tracts of land
lately planted with pines have been almost completely drained of moisture
by some unknown action of the trees. It is argued that the alleged drainage
is not due to the conducting power of the roots, inasmuch as the roots of the
pine do not descend lower than those of the oak and other deciduous trees
which produce no such effect, and it is suggested that the foliage of the pine
continues to exhale through the winter a sufficient quantity of moisture to
account for the drying up of the soil. This explanation is improbable, and I
know nothing in American experience of the forest which accords with the
alleged facts. It is true that the pines, the firs, the hemlock, and all the spike-
leaved evergreens prefer a dry soil, but it has not been observed that such
soils become less dry after the felling of their trees. The cedars and other
along the ridges, when practicable, because there only was the earth dry
enough to allow of their construction, and, for the same reason, the cabins
of the first settlers were perched upon the hills. As the forests have been
from time to time removed, and the face of the earth laid open to the air and
sun, the moisture has been evaporated, and the removal of the highways and
of human habitations from the bleak hills to the sheltered valleys, is one of
the most agreeable among the many improvements which later generations
have witnessed in the interior of the Northern States. [Footnote: The Tuscan
poet Ginati, who hod certainly had little opportunity of observing primitive
conditions of nature and of man, was aware that such must have been the
course of things in new countries. "You know," says he in a letter to a
friend, "that the hills were first occupied by man, because stagnant waters,
and afterwards continual wars, excluded men from the plains. But when
tranquillity was established and means provided for the discharge of the
waters, the low grounds were soon covered with human habitations."—
Letters, Firenze, 1864, p. 98.]
Recent observers in France affirm that evergreen trees exercise a special
desiccating action on the soil, and cases are cited where large tracts of land
lately planted with pines have been almost completely drained of moisture
by some unknown action of the trees. It is argued that the alleged drainage
is not due to the conducting power of the roots, inasmuch as the roots of the
pine do not descend lower than those of the oak and other deciduous trees
which produce no such effect, and it is suggested that the foliage of the pine
continues to exhale through the winter a sufficient quantity of moisture to
account for the drying up of the soil. This explanation is improbable, and I
know nothing in American experience of the forest which accords with the
alleged facts. It is true that the pines, the firs, the hemlock, and all the spike-
leaved evergreens prefer a dry soil, but it has not been observed that such
soils become less dry after the felling of their trees. The cedars and other
Page 275
trees of allied families grow naturally in moist ground, and the white cedar
of the Northern States, Thuya occidentalis, is chiefly found in swamps. The
roots of this tree do not penetrate deeply into the earth, but are spread out
near the surface, and of course do not carry off the waters of the swamp by
perpendicular conduction. On the contrary, by their shade, the trees prevent
the evaporation of the superficial water; but when the cedars are felled, the
swamp—which sometimes rather resembles a pool filled with aquatic trees
than a grove upon solid ground—often dries up so completely as to be fit
for cultivation without any other artificial drainage than, in the ordinary
course of cultivation, is given to other new soils. [Footnote: A special
dessicative influence has long been ascribed to the maritime pine, which
has been extensively planted on the dunes and sand-plains of western
France, and it is well established that, under certain conditions, all trees,
whether evergreen or deciduous, exercise this function, but there is no
convincing proof that in the cases now referred to there is any difference in
the mode of action of the two classes of trees. An article by D'Arbois de
Jubainville in the Revue des Eaux et Forets for April, 1869, ascribing the
same action to the Pinus sylvestris, has excited much attention in Europe,
and the facts stated by this writer constitute the strongest evidence known to
me in support of the alleged influence of evergreen trees, as distinguished
from the draining by downward conduction, which is a function exercised
by all trees, under ordinary circumstances, in proportion to their penetration
of a bibulous subsoil by tap or other descending roots. The question has
been ably discussed by Beraud in the Revue des Deux Mondes for April,
1870, the result being that the drying of the soil by pines is due simply to
conduction by the roots, whatever may be the foliage of the tree. See post:
Influence of the Forest on Flow of Springs. It is however certain, I believe,
that evergreens exhale more moisture in winter than leafless deciduous
trees, and consequently some weight is to be ascribed to this element.]
of the Northern States, Thuya occidentalis, is chiefly found in swamps. The
roots of this tree do not penetrate deeply into the earth, but are spread out
near the surface, and of course do not carry off the waters of the swamp by
perpendicular conduction. On the contrary, by their shade, the trees prevent
the evaporation of the superficial water; but when the cedars are felled, the
swamp—which sometimes rather resembles a pool filled with aquatic trees
than a grove upon solid ground—often dries up so completely as to be fit
for cultivation without any other artificial drainage than, in the ordinary
course of cultivation, is given to other new soils. [Footnote: A special
dessicative influence has long been ascribed to the maritime pine, which
has been extensively planted on the dunes and sand-plains of western
France, and it is well established that, under certain conditions, all trees,
whether evergreen or deciduous, exercise this function, but there is no
convincing proof that in the cases now referred to there is any difference in
the mode of action of the two classes of trees. An article by D'Arbois de
Jubainville in the Revue des Eaux et Forets for April, 1869, ascribing the
same action to the Pinus sylvestris, has excited much attention in Europe,
and the facts stated by this writer constitute the strongest evidence known to
me in support of the alleged influence of evergreen trees, as distinguished
from the draining by downward conduction, which is a function exercised
by all trees, under ordinary circumstances, in proportion to their penetration
of a bibulous subsoil by tap or other descending roots. The question has
been ably discussed by Beraud in the Revue des Deux Mondes for April,
1870, the result being that the drying of the soil by pines is due simply to
conduction by the roots, whatever may be the foliage of the tree. See post:
Influence of the Forest on Flow of Springs. It is however certain, I believe,
that evergreens exhale more moisture in winter than leafless deciduous
trees, and consequently some weight is to be ascribed to this element.]
Page 276
The Forest in Winter.
The influence of the woods on the flow of springs, and consequently on
the supply for the larger water-courses, naturally connects itself with the
general question of the action of the forest on the humidity of the ground.
But the special condition of the woodlands, as affected by snow and frost in
the winter of excessive climates, like that of the United States, has not been
so much studied as it deserves; and as it has a most important bearing on the
superficial hydrology of the earth, I shall make some observations upon it
before I proceed to the direct discussion of the influence of the forest on the
flow of springs.
To estimate rightly the importance of the forest in our climate as a natural
apparatus for accumulating the water that falls upon the surface and
transmitting it to the subjacent strata, we must compare the condition and
properties of its soil with those of cleared and cultivated earth, and examine
the consequently different action of these soils at different seasons of the
year. The disparity between them is greatest in climates where, as in the
Northern American States and in the extreme North of Europe, the open
ground freezes and remains impervious to water during a considerable part
of the winter; though, even in climates where the earth does not freeze at
all, the woods have still an important influence of the same character. The
difference is yet greater in countries which have regular wet and dry
seasons, rain being very frequent in the former period, while, in the latter, it
scarcely occurs at all. These countries lie chiefly in or near the tropics, but
they are not wanting in higher latitudes; for a large part of Asiatic and even
of European Turkey is almost wholly deprived of summer rains. In the
principal regions occupied by European cultivation, and where alone the
questions discussed in this volume are recognized as having, at present, any
practical importance, more or less rain falls at all seasons, and it is to these
regions that, on this point as well as others, I chiefly confine my attention.
The influence of the woods on the flow of springs, and consequently on
the supply for the larger water-courses, naturally connects itself with the
general question of the action of the forest on the humidity of the ground.
But the special condition of the woodlands, as affected by snow and frost in
the winter of excessive climates, like that of the United States, has not been
so much studied as it deserves; and as it has a most important bearing on the
superficial hydrology of the earth, I shall make some observations upon it
before I proceed to the direct discussion of the influence of the forest on the
flow of springs.
To estimate rightly the importance of the forest in our climate as a natural
apparatus for accumulating the water that falls upon the surface and
transmitting it to the subjacent strata, we must compare the condition and
properties of its soil with those of cleared and cultivated earth, and examine
the consequently different action of these soils at different seasons of the
year. The disparity between them is greatest in climates where, as in the
Northern American States and in the extreme North of Europe, the open
ground freezes and remains impervious to water during a considerable part
of the winter; though, even in climates where the earth does not freeze at
all, the woods have still an important influence of the same character. The
difference is yet greater in countries which have regular wet and dry
seasons, rain being very frequent in the former period, while, in the latter, it
scarcely occurs at all. These countries lie chiefly in or near the tropics, but
they are not wanting in higher latitudes; for a large part of Asiatic and even
of European Turkey is almost wholly deprived of summer rains. In the
principal regions occupied by European cultivation, and where alone the
questions discussed in this volume are recognized as having, at present, any
practical importance, more or less rain falls at all seasons, and it is to these
regions that, on this point as well as others, I chiefly confine my attention.
Page 277
Importance of Snow.
Recent observations in Switzerland give a new importance to the
hygrometrical functions of snow, and of course to the forest as its
accumulator and protector. I refer to statements of the condensation of
atmospheric vapor by the snows and glaciers of the Rhone basin, where it is
estimated to be nearly equal to the entire precipitation of the valley.
Whenever the humidity of the atmosphere in contact with snow is above the
point of saturation at the temperature to which the air is cooled by such
contact, the superfluous moisture is absorbed by the snow or condensed and
frozen upon its surface, and of course adds so much to the winter supply of
water received from the snow by the ground. This quantity, in all
probability, much exceeds the loss by evaporation, for during the period
when the ground is covered with snow, the proportion of clear dry weather
favorable to evaporation is less than that of humid days with an atmosphere
in a condition to yield up its moisture to any bibulous substance cold
enough to condense it. [Footnote: The hard snow-crust, which in the early
spring is a source of such keen enjoyment to the children and youth of the
North—and to many older persons in whom the love of nature has kept
awake a relish for the simple pleasures of rural life—is doubtless due to the
congelation of the vapor condensed by the snow rather than to the thawing
and freezing of the superficial stratum; for when the surface is melted by
the sun, the water is taken up by the absorbent mass beneath before the
temperature falls low enough to freeze it.]
In our Northern States, irregular as is the climate, the first autumnal
snows pretty constantly fall before the ground is frozen at all, or when the
frost extends at most to the depth of only a few inches. [Footnote: The hard
autumnal frosts are usually preceded by heavy rains which thoroughly
moisten the soil, and it is a common saying in the North that "the ground
will not freeze till the swamps are full."] In the woods, especially those
Recent observations in Switzerland give a new importance to the
hygrometrical functions of snow, and of course to the forest as its
accumulator and protector. I refer to statements of the condensation of
atmospheric vapor by the snows and glaciers of the Rhone basin, where it is
estimated to be nearly equal to the entire precipitation of the valley.
Whenever the humidity of the atmosphere in contact with snow is above the
point of saturation at the temperature to which the air is cooled by such
contact, the superfluous moisture is absorbed by the snow or condensed and
frozen upon its surface, and of course adds so much to the winter supply of
water received from the snow by the ground. This quantity, in all
probability, much exceeds the loss by evaporation, for during the period
when the ground is covered with snow, the proportion of clear dry weather
favorable to evaporation is less than that of humid days with an atmosphere
in a condition to yield up its moisture to any bibulous substance cold
enough to condense it. [Footnote: The hard snow-crust, which in the early
spring is a source of such keen enjoyment to the children and youth of the
North—and to many older persons in whom the love of nature has kept
awake a relish for the simple pleasures of rural life—is doubtless due to the
congelation of the vapor condensed by the snow rather than to the thawing
and freezing of the superficial stratum; for when the surface is melted by
the sun, the water is taken up by the absorbent mass beneath before the
temperature falls low enough to freeze it.]
In our Northern States, irregular as is the climate, the first autumnal
snows pretty constantly fall before the ground is frozen at all, or when the
frost extends at most to the depth of only a few inches. [Footnote: The hard
autumnal frosts are usually preceded by heavy rains which thoroughly
moisten the soil, and it is a common saying in the North that "the ground
will not freeze till the swamps are full."] In the woods, especially those
Page 278
situated upon the elevated ridges which supply the natural irrigation of the
soil and feed the perennial fountains and streams, the ground remains
covered with snow during the winter; for the trees protect the snow from
blowing from the general surface into the depressions, and new accessions
are received before the covering deposited by the first fall is melted. Snow
is of a color unfavorable for radiation, but, even when it is of considerable
thickness, it is not wholly impervious to the rays of the sun, and for this
reason, as well as from the warmth of lower strata, the frozen crust of the
soil, if one has been formed, is soon thawed, and does not again fall below
the freezing-point during the winter. [Footnote: Dr. Williams, of Vermont,
made some observations on the comparative temperature of the soil in open
and in wooded ground In the years 1789 and 1791, but they generally
belonged to the warmer months, and I do not know that any extensive series
of comparisons between the temperature of the ground in the woods and in
the fields has been attempted in America. Dr. Williams's thermometer was
sunk to the depth of ten inches, and gave the following results:
——
| Temperature | Temperature |
Time. | of ground in| of ground in| Difference.
| pasture. | woods. |
——
May 23………………….| 52 | 46 | 6
" 28………………….| 57 | 48 | 9
June 15………………….| 64 | 51 | 13 " 27………………….| 62 | 51 |
11 July 16………………….| 62 | 51 | 11 " 30………………….| 65 1/2 |
55 1/2 | 10 Aug. 15………………….| 68 | 58 | 10 " 31………………….|
59 1/2 | 55 | 4 1/2 Sept.15………………….| 59 1/2 | 55 | 4 1/2 Oct.
1………………….| 59 1/2 | 55 | 4 1/2 " 15………………….| 49 | 49 | 0
soil and feed the perennial fountains and streams, the ground remains
covered with snow during the winter; for the trees protect the snow from
blowing from the general surface into the depressions, and new accessions
are received before the covering deposited by the first fall is melted. Snow
is of a color unfavorable for radiation, but, even when it is of considerable
thickness, it is not wholly impervious to the rays of the sun, and for this
reason, as well as from the warmth of lower strata, the frozen crust of the
soil, if one has been formed, is soon thawed, and does not again fall below
the freezing-point during the winter. [Footnote: Dr. Williams, of Vermont,
made some observations on the comparative temperature of the soil in open
and in wooded ground In the years 1789 and 1791, but they generally
belonged to the warmer months, and I do not know that any extensive series
of comparisons between the temperature of the ground in the woods and in
the fields has been attempted in America. Dr. Williams's thermometer was
sunk to the depth of ten inches, and gave the following results:
——
| Temperature | Temperature |
Time. | of ground in| of ground in| Difference.
| pasture. | woods. |
——
May 23………………….| 52 | 46 | 6
" 28………………….| 57 | 48 | 9
June 15………………….| 64 | 51 | 13 " 27………………….| 62 | 51 |
11 July 16………………….| 62 | 51 | 11 " 30………………….| 65 1/2 |
55 1/2 | 10 Aug. 15………………….| 68 | 58 | 10 " 31………………….|
59 1/2 | 55 | 4 1/2 Sept.15………………….| 59 1/2 | 55 | 4 1/2 Oct.
1………………….| 59 1/2 | 55 | 4 1/2 " 15………………….| 49 | 49 | 0
Page 279
Nov. 1………………….| 43 | 43 | 0 " 16………………….| 43 1/2 | 43 1/2
|0
On the 14th of January, 1791, in a winter remarkable for its extreme
severity, he found the ground, on a plain open field where the snow had
been blown away, frozen to the depth of three feet and five inches; in the
woods where the snow was three feet deep, and where the soil had frozen to
the depth of six inches before the snow fell, the thermometer, at six inches
below the surface of the ground, stood at 39 degrees. In consequence of the
covering of the snow, therefore, the previously frozen ground had been
thawed and raised to seven degrees above the freezing-point.—William's
Vermont, i., p. 74.
Boussingault's observations are important. Employing three
thermometers, one with the bulb an inch below the surface of powdery
snow; one on the surface of the ground beneath the snow, then four
inches deep; and one in the open air, forty feet above the ground, on the
north side of a building, he found, at 5 P.M., the FIRST thermometer at
-1.5 degrees Centigrade, the second at 0 degrees, and the THIRD at + 2.5
degrees; at 7 A.M. the next morning, the first stood at -12 degrees, the
second at -3.5 degrees and the third at -3 degrees; at 5.30 the same
evening No. 1 stood at -1.4 degrees, No. 2 at 0 degrees, and No. 3 at + 3
degrees. Other experiments were tried, and though the temperature was
affected by the radiation, which varied with the hour of the day and the
state of the sky, the upper surface of the snow was uniformly colder than
the lower, or than the open air.
According to the Report of the Department of Agriculture for May and
June, 1872, Mr. C. G. Prindle, of Vermont, in the preceding winter, found,
for four successive days, the temperature immediately above the snow at 13
|0
On the 14th of January, 1791, in a winter remarkable for its extreme
severity, he found the ground, on a plain open field where the snow had
been blown away, frozen to the depth of three feet and five inches; in the
woods where the snow was three feet deep, and where the soil had frozen to
the depth of six inches before the snow fell, the thermometer, at six inches
below the surface of the ground, stood at 39 degrees. In consequence of the
covering of the snow, therefore, the previously frozen ground had been
thawed and raised to seven degrees above the freezing-point.—William's
Vermont, i., p. 74.
Boussingault's observations are important. Employing three
thermometers, one with the bulb an inch below the surface of powdery
snow; one on the surface of the ground beneath the snow, then four
inches deep; and one in the open air, forty feet above the ground, on the
north side of a building, he found, at 5 P.M., the FIRST thermometer at
-1.5 degrees Centigrade, the second at 0 degrees, and the THIRD at + 2.5
degrees; at 7 A.M. the next morning, the first stood at -12 degrees, the
second at -3.5 degrees and the third at -3 degrees; at 5.30 the same
evening No. 1 stood at -1.4 degrees, No. 2 at 0 degrees, and No. 3 at + 3
degrees. Other experiments were tried, and though the temperature was
affected by the radiation, which varied with the hour of the day and the
state of the sky, the upper surface of the snow was uniformly colder than
the lower, or than the open air.
According to the Report of the Department of Agriculture for May and
June, 1872, Mr. C. G. Prindle, of Vermont, in the preceding winter, found,
for four successive days, the temperature immediately above the snow at 13
Page 280
degrees below zero; beneath the snow, which was but four inches deep, at
19 degrees above zero; and under a drift two feet deep, at 27 degrees above.
On the borders and in the glades of the American forest, violets and other
small plants begin to vegetate as soon as the snow has thawed the soil
around their roots, and they are not unfrequently found in full flower under
two or three feet of snow.—American Naturalist, May, 1869, pp. 155, 156.
In very cold weather, when the ground is covered with light snow, flocks
of the grouse of the Eastern States often plunge into the snow about sunset,
and pass the night in this warm shelter. If the weather moderates before
morning, a frozen crust is sometimes formed on the surface too strong to be
broken by the birds, which consequently perish.] The snow in contact with
the earth now begins to melt, with greater or less rapidity, according to the
relative temperature of the earth and the air, while the water resulting from
its dissolution is imbibed by the vegetable mould, and carried off by
infiltration so fast that both the snow and the layers of leaves in contact
with it often seem comparatively dry, when, in fact, the under-surface of the
former is in a state of perpetual thaw. No doubt a certain proportion of the
snow is given off to the atmosphere by direct evaporation, but in the woods,
the protection against the sun by even leafless trees prevents much loss in
this way, and besides, the snow receives much moisture from the air by
absorption and condensation. Very little water runs off in the winter by
superficial water-courses, except in rare cases of sudden thaw, and there can
be no question that much the greater part of the snow deposited in the forest
is slowly melted and absorbed by the earth.
The immense importance of the forest, as a reservoir of this stock of
moisture, becomes apparent, when we consider that a large proportion of
the summer rain either flows into the valleys and the rivers, because it falls
faster than the ground can imbibe it; or, if absorbed by the warm superficial
19 degrees above zero; and under a drift two feet deep, at 27 degrees above.
On the borders and in the glades of the American forest, violets and other
small plants begin to vegetate as soon as the snow has thawed the soil
around their roots, and they are not unfrequently found in full flower under
two or three feet of snow.—American Naturalist, May, 1869, pp. 155, 156.
In very cold weather, when the ground is covered with light snow, flocks
of the grouse of the Eastern States often plunge into the snow about sunset,
and pass the night in this warm shelter. If the weather moderates before
morning, a frozen crust is sometimes formed on the surface too strong to be
broken by the birds, which consequently perish.] The snow in contact with
the earth now begins to melt, with greater or less rapidity, according to the
relative temperature of the earth and the air, while the water resulting from
its dissolution is imbibed by the vegetable mould, and carried off by
infiltration so fast that both the snow and the layers of leaves in contact
with it often seem comparatively dry, when, in fact, the under-surface of the
former is in a state of perpetual thaw. No doubt a certain proportion of the
snow is given off to the atmosphere by direct evaporation, but in the woods,
the protection against the sun by even leafless trees prevents much loss in
this way, and besides, the snow receives much moisture from the air by
absorption and condensation. Very little water runs off in the winter by
superficial water-courses, except in rare cases of sudden thaw, and there can
be no question that much the greater part of the snow deposited in the forest
is slowly melted and absorbed by the earth.
The immense importance of the forest, as a reservoir of this stock of
moisture, becomes apparent, when we consider that a large proportion of
the summer rain either flows into the valleys and the rivers, because it falls
faster than the ground can imbibe it; or, if absorbed by the warm superficial
Page 281
strata, is evaporated from them without sinking deep enough to reach wells
and springs, which, of course, depend much on winter rains and snows for
their entire supply. This observation, though specially true of cleared and
cultivated grounds, is not wholly inapplicable to the forest, particularly
when, as is too often the case in Europe, the underwood and the decaying
leaves are removed.
The quantity of snow that falls in extensive forests, far from the open
country, has seldom been ascertained by direct observation, because there
are few meteorological stations in or near the forest. According to
Thompson, [Footnote: Thompson's Vermont, Appendix, p. 8.] the
proportion of water which falls in snow in the Northern States does not
exceed one-fifth of the total precipitation, but the moisture derived from it
is doubtless considerably increased by the atmospheric vapor absorbed by
it, or condensed and frozen on its surface. I think I can say from experience
—and I am confirmed in this opinion by the testimony of competent
observers whose attention has been directed specially to the point—that
though much snow is intercepted by the trees, and the quantity on the
ground in the woods is consequently less than in open land in the first part
of the winter, yet most of what reaches the ground at that season remains
under the protection of the wood until melted, and as it occasionally
receives new supplies the depth of snow in the forest in the latter half of
winter is considerably greater than in the cleared fields. Careful
measurements in a snowy region in New England, in the month of
February, gave a mean of 38 inches in the open ground and 44 inches in the
woods. [Footnote: As the loss of snow by evaporation has been probably
exaggerated by popular opinion, an observation or two on the subject may
not be amiss in this place. It is true that in the open grounds, in clear
weather and with a dry atmosphere, snow and ice are evaporated with great
rapidity even when the thermometer is much below the freezing-point; and
Darwin informs us that the snow on the summit of Aconcagua, 23,000 feet
and springs, which, of course, depend much on winter rains and snows for
their entire supply. This observation, though specially true of cleared and
cultivated grounds, is not wholly inapplicable to the forest, particularly
when, as is too often the case in Europe, the underwood and the decaying
leaves are removed.
The quantity of snow that falls in extensive forests, far from the open
country, has seldom been ascertained by direct observation, because there
are few meteorological stations in or near the forest. According to
Thompson, [Footnote: Thompson's Vermont, Appendix, p. 8.] the
proportion of water which falls in snow in the Northern States does not
exceed one-fifth of the total precipitation, but the moisture derived from it
is doubtless considerably increased by the atmospheric vapor absorbed by
it, or condensed and frozen on its surface. I think I can say from experience
—and I am confirmed in this opinion by the testimony of competent
observers whose attention has been directed specially to the point—that
though much snow is intercepted by the trees, and the quantity on the
ground in the woods is consequently less than in open land in the first part
of the winter, yet most of what reaches the ground at that season remains
under the protection of the wood until melted, and as it occasionally
receives new supplies the depth of snow in the forest in the latter half of
winter is considerably greater than in the cleared fields. Careful
measurements in a snowy region in New England, in the month of
February, gave a mean of 38 inches in the open ground and 44 inches in the
woods. [Footnote: As the loss of snow by evaporation has been probably
exaggerated by popular opinion, an observation or two on the subject may
not be amiss in this place. It is true that in the open grounds, in clear
weather and with a dry atmosphere, snow and ice are evaporated with great
rapidity even when the thermometer is much below the freezing-point; and
Darwin informs us that the snow on the summit of Aconcagua, 23,000 feet
Page 282
high, and of course in a temperature of perpetual frost, is sometimes carried
off by evaporation. The surface of the snow in our woods, however, does
not indicate much loss in this way. Very small deposits of snow-flakes
remain unevaporated in the forest, for many days after snow which fell at
the same time in the cleared field has disappeared without either a thaw to
melt it or a wind powerful enough to drift it away. Even when bared of their
leaven, the trees of a wood obstruct, in an important degree, both the direct
action of the sun's rays on the snow and the movement of drying and
thawing winds.
Dr. Piper (Trees of America, p. 48) records the following observations:
"A body of snow, one foot in depth and sixteen feet square, was protected
from the wind by a tight board fence about five feet high, while another
body of snow, much more sheltered from the sun than the first, six feet in
depth, and about sixteen feet square, was fully exposed to the wind. When
the thaw came on, which lasted about a fortnight, the larger body of snow
was entirely dissolved in less than a week, while the smaller body was not
wholly gone at the end of the second week. "Equal quantities of snow were
placed in vessels of the samekind and capacity, the temperature of the air
being seventy degrees. In the one case, a constant current of air was kept
passing over the open vessel, while the other was protected by a cover. The
snow in the first was dissolved in sixteen minutes, while the latter had a
small unthawed proportion remaining at the end of eighty-five minutes."
The snow in the woods is protected in the same way, though not literally to
the same extent, as by the fence in one of these cases and the cover in the
other.]
The general effect of the forest in cold climates is to assimilate the winter
state of the ground to that of wooded regions under softer skies; and it is a
circumstance well worth noting, that in Southern Europe, where Nature has
denied to the earth a warm winter-garment of flocculent snow, she has, by
off by evaporation. The surface of the snow in our woods, however, does
not indicate much loss in this way. Very small deposits of snow-flakes
remain unevaporated in the forest, for many days after snow which fell at
the same time in the cleared field has disappeared without either a thaw to
melt it or a wind powerful enough to drift it away. Even when bared of their
leaven, the trees of a wood obstruct, in an important degree, both the direct
action of the sun's rays on the snow and the movement of drying and
thawing winds.
Dr. Piper (Trees of America, p. 48) records the following observations:
"A body of snow, one foot in depth and sixteen feet square, was protected
from the wind by a tight board fence about five feet high, while another
body of snow, much more sheltered from the sun than the first, six feet in
depth, and about sixteen feet square, was fully exposed to the wind. When
the thaw came on, which lasted about a fortnight, the larger body of snow
was entirely dissolved in less than a week, while the smaller body was not
wholly gone at the end of the second week. "Equal quantities of snow were
placed in vessels of the samekind and capacity, the temperature of the air
being seventy degrees. In the one case, a constant current of air was kept
passing over the open vessel, while the other was protected by a cover. The
snow in the first was dissolved in sixteen minutes, while the latter had a
small unthawed proportion remaining at the end of eighty-five minutes."
The snow in the woods is protected in the same way, though not literally to
the same extent, as by the fence in one of these cases and the cover in the
other.]
The general effect of the forest in cold climates is to assimilate the winter
state of the ground to that of wooded regions under softer skies; and it is a
circumstance well worth noting, that in Southern Europe, where Nature has
denied to the earth a warm winter-garment of flocculent snow, she has, by
Page 283
one of those compensations in which her empire is so rich, clothed the
hillsides with umbrella and other pines, ilexes, cork-oaks, bays and other
trees of persistent foliage, whose evergreen leaves afford to the soil a
protection analogous to that which it derives from snow in more northern
climates.
The water imbibed by the soil in winter sinks until it meets a more or less
impermeable or a saturated stratum, and then, by unseen conduits, slowly
finds its way to the channels springs, or oozes out of the ground in drops
which unite in rills, and so all is conveyed to the larger streams, and by
them finally to the sea. The water, in percolating through the vegetable and
mineral layers, acquires their temperature, and is chemically affected by
their action, but it carries very little matter in mechanical suspension.
The process I have described is a slow one, and the supply of moisture
derived from the snow, augmented by the rains of the following seasons,
keeps the forest-ground, where the surface is level or but moderately
inclined, in a state of approximate saturation throughout almost the whole
year. [Footnote: The statements I have made, here and elsewhere, respecting
the humidity of the soil in natural forests, have been, I understand, denied
by Mr. T. Meehan, a distinguished American naturalist, in a paper which I
have not seen He is quoted as maintaining, among other highly questionable
propositions that no ground is "so dry in its subsoil as that which sustains a
forest on its surface." In open, artificially planted woods, with a smooth and
regular surface, and especially in forests where the fallen leaves and
branches are annually burnt or carried off, both the superficial and the
subjacent strata may under certain circumstances, become dry, but this
rarely, if ever, happens in a wood of spontaneous growth, undeprived of the
protection afforded by its own droppings, and of the natural accidents of
surface which tend to the retention of water. See, on this point, a very able
article by Mr. Henry Stewart, in the New York Tribune of November 23,
hillsides with umbrella and other pines, ilexes, cork-oaks, bays and other
trees of persistent foliage, whose evergreen leaves afford to the soil a
protection analogous to that which it derives from snow in more northern
climates.
The water imbibed by the soil in winter sinks until it meets a more or less
impermeable or a saturated stratum, and then, by unseen conduits, slowly
finds its way to the channels springs, or oozes out of the ground in drops
which unite in rills, and so all is conveyed to the larger streams, and by
them finally to the sea. The water, in percolating through the vegetable and
mineral layers, acquires their temperature, and is chemically affected by
their action, but it carries very little matter in mechanical suspension.
The process I have described is a slow one, and the supply of moisture
derived from the snow, augmented by the rains of the following seasons,
keeps the forest-ground, where the surface is level or but moderately
inclined, in a state of approximate saturation throughout almost the whole
year. [Footnote: The statements I have made, here and elsewhere, respecting
the humidity of the soil in natural forests, have been, I understand, denied
by Mr. T. Meehan, a distinguished American naturalist, in a paper which I
have not seen He is quoted as maintaining, among other highly questionable
propositions that no ground is "so dry in its subsoil as that which sustains a
forest on its surface." In open, artificially planted woods, with a smooth and
regular surface, and especially in forests where the fallen leaves and
branches are annually burnt or carried off, both the superficial and the
subjacent strata may under certain circumstances, become dry, but this
rarely, if ever, happens in a wood of spontaneous growth, undeprived of the
protection afforded by its own droppings, and of the natural accidents of
surface which tend to the retention of water. See, on this point, a very able
article by Mr. Henry Stewart, in the New York Tribune of November 23,
Page 284
1873.] It may be proper to observe here that in Italy, and in many parts of
Spain and France, the Alps, the Apennines, and the Pyrenees, not to speak
of less important mountains, perform the functions which provident nature
has in other regions assigned to the forest, that is, they act as reservoirs
wherein is accumulated in winter a supply of moisture to nourish the
parched plains during the droughts of summer. Hence, however enormous
may be the evils which have accrued to the above-mentioned countries from
the destruction of the woods, the absolute desolation which would
otherwise have smitten them through the folly of man, has been partially
prevented by those natural dispositions, by means of which there are stored
up in the glaciers, in the snow-fields, and in the basins of mountains and
valleys, vast deposits of condensed moisture which are afterwards
distributed in a liquid form during the season in which the atmosphere
furnishes a slender supply of the beneficent fluid so indispensable to
vegetable and animal life. [Footnote: The accumulation of snow and ice
upon the Alps and other mountains—which often fills up valleys to the
height of hundreds of feet—is due not only to the fall or congealed and
crystallized vapor in the form of snow, to the condensation of atmospheric
vapor on the surface of snow-fields and glaciers, and to a temperature
which prevents the rapid melting of snow, but also to the well-known fact
that, at least up to the height of 10,000 feet, rain and snow are more
abundant on the mountains than at lower levels.
But another reason may be suggested for the increase of atmospheric
humidity, and consequently of the precipitation of aqueous vapor on
mountain chains. In discussing the influence of mountains on precipitation,
meteorologists have generally treated the popular belief, that mountains
"attract" to them clouds floating within a certain distance from them, as an
ignorant prejudice, and they ascribe the appearance of clouds about high
peaks solely to the condensation of the humidity of the air carried by
atmospheric currents up the slopes of the mountain to a colder temperature.
Spain and France, the Alps, the Apennines, and the Pyrenees, not to speak
of less important mountains, perform the functions which provident nature
has in other regions assigned to the forest, that is, they act as reservoirs
wherein is accumulated in winter a supply of moisture to nourish the
parched plains during the droughts of summer. Hence, however enormous
may be the evils which have accrued to the above-mentioned countries from
the destruction of the woods, the absolute desolation which would
otherwise have smitten them through the folly of man, has been partially
prevented by those natural dispositions, by means of which there are stored
up in the glaciers, in the snow-fields, and in the basins of mountains and
valleys, vast deposits of condensed moisture which are afterwards
distributed in a liquid form during the season in which the atmosphere
furnishes a slender supply of the beneficent fluid so indispensable to
vegetable and animal life. [Footnote: The accumulation of snow and ice
upon the Alps and other mountains—which often fills up valleys to the
height of hundreds of feet—is due not only to the fall or congealed and
crystallized vapor in the form of snow, to the condensation of atmospheric
vapor on the surface of snow-fields and glaciers, and to a temperature
which prevents the rapid melting of snow, but also to the well-known fact
that, at least up to the height of 10,000 feet, rain and snow are more
abundant on the mountains than at lower levels.
But another reason may be suggested for the increase of atmospheric
humidity, and consequently of the precipitation of aqueous vapor on
mountain chains. In discussing the influence of mountains on precipitation,
meteorologists have generally treated the popular belief, that mountains
"attract" to them clouds floating within a certain distance from them, as an
ignorant prejudice, and they ascribe the appearance of clouds about high
peaks solely to the condensation of the humidity of the air carried by
atmospheric currents up the slopes of the mountain to a colder temperature.
Page 285
But if mountains do not really draw clouds and invisible vapors to them,
they are an exception to the universal law of attraction. The attraction of the
small Mount Shehallien was found sufficient to deflect from the
perpendicular, by a measurable quantity, a plummet weighing but a few
ounces. Why, then, should not greater masses attract to them volumes of
vapor weighing many tons, and floating freely in the atmosphere within
moderate distances of the mountains ]
Summer Rains, Importance of.
Babinet quotes a French proverb: "Summer rain wets nothing," and
explains it by saying that at that season the rainwater is "almost entirely
carried off by evaporation." "The rains of summer," he adds, "however
abundant they may be, do not penetrate the soil beyond the depth of six or
eight inches. In summer the evaporating power of the heat is five or six
times greater than in winter, and this force is exerted by an atmosphere
capable of containing five or six times as much vapor as in winter." "A
stratum of snow which prevents evaporation [from the ground], causes
almost all the water that composes it to filter into the earth, and forms a
provision for fountains, wells, and streams which could not be furnished by
any quantity whatever of summer rain. This latter, useful to vegetation like
the dew, neither penetrates the soil nor accumulates a store to supply the
springs and to be given out again into the open air." [Footnote: Etudes et
Lectures, vol. vi., p. 118. The experiments or Johnstrup in the vicinity of
Copenhagen, where the mean annual precipitation is 23 1/2 inches, and
where the evaporation must be less than in the warmer and drier atmosphere
of France, form the most careful series of observations on this subject
which I have met with. Johnstrup found that at the depth at a metre and a
half (50 inches) the effects of rain and evaporation were almost
imperceptible, and became completely so at a depth of from two to three
they are an exception to the universal law of attraction. The attraction of the
small Mount Shehallien was found sufficient to deflect from the
perpendicular, by a measurable quantity, a plummet weighing but a few
ounces. Why, then, should not greater masses attract to them volumes of
vapor weighing many tons, and floating freely in the atmosphere within
moderate distances of the mountains ]
Summer Rains, Importance of.
Babinet quotes a French proverb: "Summer rain wets nothing," and
explains it by saying that at that season the rainwater is "almost entirely
carried off by evaporation." "The rains of summer," he adds, "however
abundant they may be, do not penetrate the soil beyond the depth of six or
eight inches. In summer the evaporating power of the heat is five or six
times greater than in winter, and this force is exerted by an atmosphere
capable of containing five or six times as much vapor as in winter." "A
stratum of snow which prevents evaporation [from the ground], causes
almost all the water that composes it to filter into the earth, and forms a
provision for fountains, wells, and streams which could not be furnished by
any quantity whatever of summer rain. This latter, useful to vegetation like
the dew, neither penetrates the soil nor accumulates a store to supply the
springs and to be given out again into the open air." [Footnote: Etudes et
Lectures, vol. vi., p. 118. The experiments or Johnstrup in the vicinity of
Copenhagen, where the mean annual precipitation is 23 1/2 inches, and
where the evaporation must be less than in the warmer and drier atmosphere
of France, form the most careful series of observations on this subject
which I have met with. Johnstrup found that at the depth at a metre and a
half (50 inches) the effects of rain and evaporation were almost
imperceptible, and became completely so at a depth of from two to three
Page 286
metres (6 1/2 to 10 feet). During the summer half of the year the
evaporation rather exceeded the rainfall; during the winter half the entire
precipitation was absorbed by the soil and transmitted to lower strata by
infiltration. The stratum between one metre and a half (50 inches) and three
metres (10 feet) from the surface was then permanently in the condition of a
saturated sponge, neither receiving nor losing humidity during the summer
half of the year, but receiving from superior, and giving off to lower, strata
an equal amount of moisture during the winter half.—Johnstrup, Om
Fugtighedens Bezagelse i den naturlige Jordbund. Kjobenhavn, 1866.]
This conclusion, however applicable to the climate and to the soil of
France, is too broadly stated to be received as a general truth; and in
countries like the United States, where rain is comparatively rare during the
winter and abundant during the summer half of the year, common
observation shows that the quantity of water furnished by deep wells and by
natural springs depends almost as much upon the rains of summer as upon
those of the rest of the year, and consequently that a large portion of the rain
of that season must find its way into strata too deep for the water to be
wasted by evaporation.
[Footnote: According to observations at one hundred military stations in
the United States, the precipitation ranges from three and a quarter inches at
Fort Yuma in California to about seventy-two inches at Fort Pike,
Louisiana, the mean for the entire territory, not including Alaska, being
thirty-six inches. In the different sections of the Union it is as follows:
North-eastern States……………… 41 inches,
New York………………………… 36 "
Middle States……………………. 40 1/2 "
Ohio……………………………. 40 "
Southern States………………….. 51 "
evaporation rather exceeded the rainfall; during the winter half the entire
precipitation was absorbed by the soil and transmitted to lower strata by
infiltration. The stratum between one metre and a half (50 inches) and three
metres (10 feet) from the surface was then permanently in the condition of a
saturated sponge, neither receiving nor losing humidity during the summer
half of the year, but receiving from superior, and giving off to lower, strata
an equal amount of moisture during the winter half.—Johnstrup, Om
Fugtighedens Bezagelse i den naturlige Jordbund. Kjobenhavn, 1866.]
This conclusion, however applicable to the climate and to the soil of
France, is too broadly stated to be received as a general truth; and in
countries like the United States, where rain is comparatively rare during the
winter and abundant during the summer half of the year, common
observation shows that the quantity of water furnished by deep wells and by
natural springs depends almost as much upon the rains of summer as upon
those of the rest of the year, and consequently that a large portion of the rain
of that season must find its way into strata too deep for the water to be
wasted by evaporation.
[Footnote: According to observations at one hundred military stations in
the United States, the precipitation ranges from three and a quarter inches at
Fort Yuma in California to about seventy-two inches at Fort Pike,
Louisiana, the mean for the entire territory, not including Alaska, being
thirty-six inches. In the different sections of the Union it is as follows:
North-eastern States……………… 41 inches,
New York………………………… 36 "
Middle States……………………. 40 1/2 "
Ohio……………………………. 40 "
Southern States………………….. 51 "
Page 287
S. W. States and Indian Territories… 39 1/2 "
Western States and Territories…….. 30 "
Texas and New Mexico……………… 24 1/2 "
California………………………. 18 1/2 "
Oregon and Washington Territory……. 50 "
The mountainous regions, it appears, do not recieve the greatest amount
of precipitation. The avenge downfall of the Southern States bordering on
the Atlantic and the Gulf of Mexico exceeds the mean of the whole United
States, being no less than fifty-one inches, while on the Pacific coast it
ranges from fifty to fifty-six inches.
As a general rule, it may be stated that at the stations on or near the sea-
coast the precipitation is greatest in the spring months, though there are
several exceptions to this remark, and at a large majority of the stations the
downfall is considerably greater in the summer months than at any other
season.]
Dalton's experiments in the years 1796, 1797, and 1798 appeared to show
that the mean absorption of the downfall by the earth in those years was
twenty-nine per cent.
Dickinson, employing the same apparatus for eight years, found the
absorption to vary widely in different years, the mean being forty-seven per
cent.
Charnock's experiments in two years show an absorption of from
seventeen to twenty-seven per cent.] Besides, even admitting that the water
from summer rains is so completely evaporated as to contribute nothing
directly to the supply of springs, it at least tends indirectly to maintain their
flow, because it saturates in part the atmosphere, and at the same time it
prevents the heat of the sun from drying the earth to still greater depths, and
Western States and Territories…….. 30 "
Texas and New Mexico……………… 24 1/2 "
California………………………. 18 1/2 "
Oregon and Washington Territory……. 50 "
The mountainous regions, it appears, do not recieve the greatest amount
of precipitation. The avenge downfall of the Southern States bordering on
the Atlantic and the Gulf of Mexico exceeds the mean of the whole United
States, being no less than fifty-one inches, while on the Pacific coast it
ranges from fifty to fifty-six inches.
As a general rule, it may be stated that at the stations on or near the sea-
coast the precipitation is greatest in the spring months, though there are
several exceptions to this remark, and at a large majority of the stations the
downfall is considerably greater in the summer months than at any other
season.]
Dalton's experiments in the years 1796, 1797, and 1798 appeared to show
that the mean absorption of the downfall by the earth in those years was
twenty-nine per cent.
Dickinson, employing the same apparatus for eight years, found the
absorption to vary widely in different years, the mean being forty-seven per
cent.
Charnock's experiments in two years show an absorption of from
seventeen to twenty-seven per cent.] Besides, even admitting that the water
from summer rains is so completely evaporated as to contribute nothing
directly to the supply of springs, it at least tends indirectly to maintain their
flow, because it saturates in part the atmosphere, and at the same time it
prevents the heat of the sun from drying the earth to still greater depths, and
Page 288
bringing within the reach of evaporation the moisture of strata which
ordinarily do not feel the effects of solar irradiation.
Influence of the Forest on the Flow of Springs.
It is an almost universal and, I believe, well-founded opinion, that the
protection afforded by the forest against the escape of moisture from its soil
by superficial flow and evaporation insures the permanence and regularity
of natural springs, not only within the limits of the wood, but at some
distance beyond its borders, and thus contributes to the supply of an
element essential to both vegetable and animal life. As the forests are
destroyed, the springs which flowed from the woods, and, consequently, the
greater water-courses fed by them, diminish both in number and in volume.
This fact is so familiar throughout the American States and the British
Provinces, that there are few old residents of the interior of those districts
who are not able to testify to its truth as a matter of personal observation.
My own recollection suggests to me many instances of this sort, and I
remember one case where a small mountain spring, which disappeared soon
after the clearing of the ground where it rose, was recovered about twenty
years ago, by simply allowing the bushes and young trees to grow up on a
rocky knoll, not more than half an acre in extent, immediately above the
spring. The ground was hardly shaded before the water reappeared, and it
has ever since continued to flow without interruption. The hills in the
Atlantic States formerly abounded in springs and brooks, but in many parts
of these States which were cleared a generation or two ago, the hill-pastures
now suffer severely from drought, and in dry seasons furnish to cattle
neither grass nor water.
Almost every treatise on the economy of the forest adduces facts in
support of the doctrine that the clearing of the woods tends to diminish the
flow of springs and the humidity of the soil, and it might seem unnecessary
ordinarily do not feel the effects of solar irradiation.
Influence of the Forest on the Flow of Springs.
It is an almost universal and, I believe, well-founded opinion, that the
protection afforded by the forest against the escape of moisture from its soil
by superficial flow and evaporation insures the permanence and regularity
of natural springs, not only within the limits of the wood, but at some
distance beyond its borders, and thus contributes to the supply of an
element essential to both vegetable and animal life. As the forests are
destroyed, the springs which flowed from the woods, and, consequently, the
greater water-courses fed by them, diminish both in number and in volume.
This fact is so familiar throughout the American States and the British
Provinces, that there are few old residents of the interior of those districts
who are not able to testify to its truth as a matter of personal observation.
My own recollection suggests to me many instances of this sort, and I
remember one case where a small mountain spring, which disappeared soon
after the clearing of the ground where it rose, was recovered about twenty
years ago, by simply allowing the bushes and young trees to grow up on a
rocky knoll, not more than half an acre in extent, immediately above the
spring. The ground was hardly shaded before the water reappeared, and it
has ever since continued to flow without interruption. The hills in the
Atlantic States formerly abounded in springs and brooks, but in many parts
of these States which were cleared a generation or two ago, the hill-pastures
now suffer severely from drought, and in dry seasons furnish to cattle
neither grass nor water.
Almost every treatise on the economy of the forest adduces facts in
support of the doctrine that the clearing of the woods tends to diminish the
flow of springs and the humidity of the soil, and it might seem unnecessary
Page 289
to bring forward further evidence on this point. [Footnote: "Why go so far
for the proof of a phenomenon that is repeated every day under our own
eyes, and of which every Parisian may convince himself, without venturing
beyond the Bois de Boulogne or the forest of Meudon Let him, after a few
rainy days, pass alone the Chevreuse road, which is bordered on the right by
the wood, on the left by cultivated fields. The fall of water and the
continuance of the rain have been the same on both sides; but the ditch on
the side of the forest will remain filled with water proceeding from the
infiltration through the wooded soil, long after the other, contiguous to the
open ground, has performed its office of drainage and become dry. The
ditch on the left will have discharged in a few hours a quantity of water,
which the ditch on the right requires several days to receive and carry down
to the valley."—Clave, Etudes, etc., pp. 53, 54.] But the subject is of too
much practical importance and of too great philosophical interest to be
summarily disposed of; and it ought to be noticed that there is at least one
case—that of some loose sandy soils which, as observed by Valles,
[Footnote: Valles, Etudes sur les Inondations, p. 472.] when bared of wood
very rapidly absorb and transmit to lower strata the water they receive from
the atmosphere—where the removal of the forest may increase the flow of
springs at levels below it, by exposing to the rain and melted snow a surface
more bibulous, and at the same time less retentive, than its original
covering. Under such circumstances, the water of precipitation, which had
formerly been absorbed by the vegetable mould and retained until it was
evaporated, might descend through porous earth until it meets an
impermeable stratum, and then be conducted along it, until, finally, at the
outcropping of this stratum, it bursts from a hillside as a running spring. But
such instances are doubtless too rare to form a frequent or an important
exception to the general law, because it is very seldom the case that such a
soil as has just been supposed is covered by a layer of vegetable earth thick
for the proof of a phenomenon that is repeated every day under our own
eyes, and of which every Parisian may convince himself, without venturing
beyond the Bois de Boulogne or the forest of Meudon Let him, after a few
rainy days, pass alone the Chevreuse road, which is bordered on the right by
the wood, on the left by cultivated fields. The fall of water and the
continuance of the rain have been the same on both sides; but the ditch on
the side of the forest will remain filled with water proceeding from the
infiltration through the wooded soil, long after the other, contiguous to the
open ground, has performed its office of drainage and become dry. The
ditch on the left will have discharged in a few hours a quantity of water,
which the ditch on the right requires several days to receive and carry down
to the valley."—Clave, Etudes, etc., pp. 53, 54.] But the subject is of too
much practical importance and of too great philosophical interest to be
summarily disposed of; and it ought to be noticed that there is at least one
case—that of some loose sandy soils which, as observed by Valles,
[Footnote: Valles, Etudes sur les Inondations, p. 472.] when bared of wood
very rapidly absorb and transmit to lower strata the water they receive from
the atmosphere—where the removal of the forest may increase the flow of
springs at levels below it, by exposing to the rain and melted snow a surface
more bibulous, and at the same time less retentive, than its original
covering. Under such circumstances, the water of precipitation, which had
formerly been absorbed by the vegetable mould and retained until it was
evaporated, might descend through porous earth until it meets an
impermeable stratum, and then be conducted along it, until, finally, at the
outcropping of this stratum, it bursts from a hillside as a running spring. But
such instances are doubtless too rare to form a frequent or an important
exception to the general law, because it is very seldom the case that such a
soil as has just been supposed is covered by a layer of vegetable earth thick
Page 290
enough to retain, until it is evaporated, all the rain that falls upon it, without
imparting any water to the strata below it.
If we look at the point under discussion as purely a question of fact, to be
determined by positive evidence and not by argument, the observations of
Boussingault are, both in the circumstances they detail and in the weight to
be attached to the testimony, among the most important yet recorded. The
interest of the question will justify me in giving, nearly in Boussingault's
own words, the facts and some of the remarks with which he accompanies
the detail of them. "In many localities," he observes, [Footnote: Economie
Rurale t. ii, p. 780.] "it has been thought that, within a certain number of
years, a sensible diminution has been perceived in the volume of water of
streams utilized as a motive-power; at other points, there are grounds for
believing that rivers have become shallower, and the increasing breadth of
the belt of pebbles along their banks seems to prove the loss of a part of
their water; and, finally, abundant springs have almost dried up. These
observations have been principally made in valleys bounded by high
mountains, and it has been noticed that this diminution of the waters has
immediately followed the epoch when the inhabitants have begun to
destroy, unsparingly, the woods which were spread over the face of the
land. "And here lies the practical point of the question; for if it is once
established that clearing diminishes the volume of streams, it is less
important to know to what special cause this effect is due. The rivers which
rise within the valley of Aragua, having no outlet to the ocean, form, by
their union, the Lake of Tacarigua or Valencia, having a length of about two
leagues and a half [= 7 English miles].
At the time of Humboldt's visit to the valley of Aragua, the inhabitants
were struck by the gradual diminution which the lake had been
undergoing for thirty years. In fact, by comparing the descriptions given
by historians with its actual condition, even making large allowance for
imparting any water to the strata below it.
If we look at the point under discussion as purely a question of fact, to be
determined by positive evidence and not by argument, the observations of
Boussingault are, both in the circumstances they detail and in the weight to
be attached to the testimony, among the most important yet recorded. The
interest of the question will justify me in giving, nearly in Boussingault's
own words, the facts and some of the remarks with which he accompanies
the detail of them. "In many localities," he observes, [Footnote: Economie
Rurale t. ii, p. 780.] "it has been thought that, within a certain number of
years, a sensible diminution has been perceived in the volume of water of
streams utilized as a motive-power; at other points, there are grounds for
believing that rivers have become shallower, and the increasing breadth of
the belt of pebbles along their banks seems to prove the loss of a part of
their water; and, finally, abundant springs have almost dried up. These
observations have been principally made in valleys bounded by high
mountains, and it has been noticed that this diminution of the waters has
immediately followed the epoch when the inhabitants have begun to
destroy, unsparingly, the woods which were spread over the face of the
land. "And here lies the practical point of the question; for if it is once
established that clearing diminishes the volume of streams, it is less
important to know to what special cause this effect is due. The rivers which
rise within the valley of Aragua, having no outlet to the ocean, form, by
their union, the Lake of Tacarigua or Valencia, having a length of about two
leagues and a half [= 7 English miles].
At the time of Humboldt's visit to the valley of Aragua, the inhabitants
were struck by the gradual diminution which the lake had been
undergoing for thirty years. In fact, by comparing the descriptions given
by historians with its actual condition, even making large allowance for
Page 291
exaggeration, it was easy to see that the level was considerably
depressed. The facts spoke for themselves. Oviedo, who, toward the
close of the sixteenth century, had often traversed the valley of Aragua,
says positively that New Valencia was founded, in 1555, at half a league
from the Lake of Tacarigua; in 1800, Humboldt found this city 5,260
metres [= 3 1/2 English miles] from the shore.
"The aspect of the soil furnished new proofs. Many hillocks on the plain
retain the name of islands, which they more justly bore when they were
surrounded by water. The ground laid bare by the retreat of the lake was
converted into admirable plantations; and buildings erected near the lake
showed the sinking of the water from year to year. In 1796, new islands
made their appearance. A fortress built in 1740 on the island of Cabrera,
was now on a peninsula; and, finally, on two granitic islands, those of Cura
and Cabo Blanco, Humboldt observed among the shrubs, somo metres
above the water, fine sand filled with helicites.
"These clear and positive facts suggested numerous explanations, all
assuming a subterranean outlet, which permitted the discharge of the water
to the ocean. Humboldt disposed of these hypotheses, and did not hesitate
to ascribe the diminution of the waters of the lake to the numerous clearings
which had been made in the valley of Aragua within half a century."
Twenty-two years later, Boussingault explored the valley of Aragua. For
some years previous, the inhabitants had observed that the waters of the
lake were no longer retiring, but, on the contrary, were sensibly rising.
Grounds, not long before occupied by plantations, were submerged. The
islands of Nuevas Aparecidas, which appeared above the surface in 1796,
had again become shoals dangerous to navigation. Cabrera, a tongue of land
on the north side of the valley, was so narrow that the least rise of the water
completely inundated it. A protracted north wind sufficed to flood the road
depressed. The facts spoke for themselves. Oviedo, who, toward the
close of the sixteenth century, had often traversed the valley of Aragua,
says positively that New Valencia was founded, in 1555, at half a league
from the Lake of Tacarigua; in 1800, Humboldt found this city 5,260
metres [= 3 1/2 English miles] from the shore.
"The aspect of the soil furnished new proofs. Many hillocks on the plain
retain the name of islands, which they more justly bore when they were
surrounded by water. The ground laid bare by the retreat of the lake was
converted into admirable plantations; and buildings erected near the lake
showed the sinking of the water from year to year. In 1796, new islands
made their appearance. A fortress built in 1740 on the island of Cabrera,
was now on a peninsula; and, finally, on two granitic islands, those of Cura
and Cabo Blanco, Humboldt observed among the shrubs, somo metres
above the water, fine sand filled with helicites.
"These clear and positive facts suggested numerous explanations, all
assuming a subterranean outlet, which permitted the discharge of the water
to the ocean. Humboldt disposed of these hypotheses, and did not hesitate
to ascribe the diminution of the waters of the lake to the numerous clearings
which had been made in the valley of Aragua within half a century."
Twenty-two years later, Boussingault explored the valley of Aragua. For
some years previous, the inhabitants had observed that the waters of the
lake were no longer retiring, but, on the contrary, were sensibly rising.
Grounds, not long before occupied by plantations, were submerged. The
islands of Nuevas Aparecidas, which appeared above the surface in 1796,
had again become shoals dangerous to navigation. Cabrera, a tongue of land
on the north side of the valley, was so narrow that the least rise of the water
completely inundated it. A protracted north wind sufficed to flood the road
Page 292
between Maracay and New Valencia. The fears which the inhabitants of the
shores had so long entertained were reversed. Those who had explained the
diminution of the lake by the supposition of subterranean channels were
suspected of blocking them up, to prove themselves in the right.
During the twenty-two years which had elapsed, the valley of Aragua had
been the theatre of bloody struggles, and war had desolated these smiling
lands and decimated their population. At the first cry of independence a
great number of slaves found their liberty by enlisting under the banners of
the new republic; the great plantations were abandoned, and the forest,
which in the tropics so rapidly encroaches, had soon recovered a large
proportion of the soil which man had wrested from it by more than a
century of constant and painful labor.
Boussingault proceeds to state that two lakes near Ubate, in New
Granada, had formed but one, a century before his visit; that the waters
were gradually retiring, and the plantations extending over the abandoned
bed; that, by inquiry of old hunters and by examination of parish records, he
found that extensive clearings had been made and were still going on.
He found, also, that the length of the Lake of Fuquene, in the same
valley, had, within two centuries, been reduced from ten leagues to one and
a half, its breadth from three leagues to one. At the former period, the
neighboring mountains were well wooded, but at the time of his visit the
mountains had been almost entirely stripped of their wood. Our author adds
that other cases, similar to those already detailed, might be cited, and he
proceeds to show, by several examples, that the waters of other lakes in the
same regions, where the valleys had always been bare of wood, or where
the forests had not been disturbed, had undergone no change of level.
Boussingault further states that the lakes of Switzerland have sustained a
depression of level since the too prevalent destruction of the woods, and
shores had so long entertained were reversed. Those who had explained the
diminution of the lake by the supposition of subterranean channels were
suspected of blocking them up, to prove themselves in the right.
During the twenty-two years which had elapsed, the valley of Aragua had
been the theatre of bloody struggles, and war had desolated these smiling
lands and decimated their population. At the first cry of independence a
great number of slaves found their liberty by enlisting under the banners of
the new republic; the great plantations were abandoned, and the forest,
which in the tropics so rapidly encroaches, had soon recovered a large
proportion of the soil which man had wrested from it by more than a
century of constant and painful labor.
Boussingault proceeds to state that two lakes near Ubate, in New
Granada, had formed but one, a century before his visit; that the waters
were gradually retiring, and the plantations extending over the abandoned
bed; that, by inquiry of old hunters and by examination of parish records, he
found that extensive clearings had been made and were still going on.
He found, also, that the length of the Lake of Fuquene, in the same
valley, had, within two centuries, been reduced from ten leagues to one and
a half, its breadth from three leagues to one. At the former period, the
neighboring mountains were well wooded, but at the time of his visit the
mountains had been almost entirely stripped of their wood. Our author adds
that other cases, similar to those already detailed, might be cited, and he
proceeds to show, by several examples, that the waters of other lakes in the
same regions, where the valleys had always been bare of wood, or where
the forests had not been disturbed, had undergone no change of level.
Boussingault further states that the lakes of Switzerland have sustained a
depression of level since the too prevalent destruction of the woods, and
Page 293
arrives at the general conclusion that, "in countries where great clearings
have been made, there has most probably been a diminution in the living
waters which flow upon the surface of theground." This conclusion he
further supports by two examples: one, where a fine spring, at the foot of a
wooded mountain in the Island of Ascension, dried up when the mountain
was cleared, but reappeared when the wood was replanted; the other at
Marmato, in the province of Popayan, where the streams employed to drive
machinery were much diminished in volume, within two years after the
clearing of the heights from which they derived their supplies. This latter is
an interesting case, because, although the rain-gauges, established as soon
as the decrease of water began to excite alarm, showed a greater fall of rain
for the second year of observation than the first, yet there was no
appreciable increase in the flow of the mill-streams. From these cases, the
distinguished physicist infers that very restricted local clearings may
diminish and even suppress springs and brooks, without any reduction in
the total quantity of rain.
It will have been noticed that these observations, with the exception of
the last two cases, do not bear directly upon the question of the diminution
of springs by clearings, but they logically infer it from the subsidence of the
natural reservoirs which springs once filled. There is, however, no want of
positive evidence on this subject. Marchand cites the following instances:
"Before the felling of the woods, within the last few years, in the valley of
the Soulce, the Combe-es-Monnin and the Little Valley, the Sorne furnished
a regular and sufficient supply of water for the ironworks of Unterwyl,
which was almost unaffected by drought or by heavy rains. The Sorne has
now become a torrent, every shower occasions a flood, and after a few days
of fine weather, the current falls so low that it has been necessary to change
the water-wheels, because those of the old construction are no longer able
to drive the machinery, and at last to introduce a steam-engine to prevent
the stoppage of the works for want of water.
have been made, there has most probably been a diminution in the living
waters which flow upon the surface of theground." This conclusion he
further supports by two examples: one, where a fine spring, at the foot of a
wooded mountain in the Island of Ascension, dried up when the mountain
was cleared, but reappeared when the wood was replanted; the other at
Marmato, in the province of Popayan, where the streams employed to drive
machinery were much diminished in volume, within two years after the
clearing of the heights from which they derived their supplies. This latter is
an interesting case, because, although the rain-gauges, established as soon
as the decrease of water began to excite alarm, showed a greater fall of rain
for the second year of observation than the first, yet there was no
appreciable increase in the flow of the mill-streams. From these cases, the
distinguished physicist infers that very restricted local clearings may
diminish and even suppress springs and brooks, without any reduction in
the total quantity of rain.
It will have been noticed that these observations, with the exception of
the last two cases, do not bear directly upon the question of the diminution
of springs by clearings, but they logically infer it from the subsidence of the
natural reservoirs which springs once filled. There is, however, no want of
positive evidence on this subject. Marchand cites the following instances:
"Before the felling of the woods, within the last few years, in the valley of
the Soulce, the Combe-es-Monnin and the Little Valley, the Sorne furnished
a regular and sufficient supply of water for the ironworks of Unterwyl,
which was almost unaffected by drought or by heavy rains. The Sorne has
now become a torrent, every shower occasions a flood, and after a few days
of fine weather, the current falls so low that it has been necessary to change
the water-wheels, because those of the old construction are no longer able
to drive the machinery, and at last to introduce a steam-engine to prevent
the stoppage of the works for want of water.
Page 294
"When the factory of St. Ursanne was established, the river that furnished
its power was abundant, and had, from time immemorial, sufficed for the
machinery of a previous factory. Afterwards, the woods near its sources
were cut. The supply of water fell off in consequence, the factory wanted
water for half the year, and was at last obliged to stop altogether.
"The spring of Combefoulat, in the commune of Seleate, was well known
as one of the best in the country; it was remarkably abundant, and
sufficient, in the severest droughts, to supply all the fountains of the town;
but as soon as considerable forests were felled in Combe-de-pre Martin and
in the valley of Combefoulat, the famous spring, which lies below these
woods, has become a mere thread of water, and disappears altogether in
times of drought.
"The spring of Varieux, which formerly supplied the castle of Pruntrut,
lost more than half its water after the clearing of Varieux and Rougeoles.
These woods have been replanted, the young trees are growing well, and,
with the woods, the waters of the spring are increasing.
"The Dog Spring between Pruntrut and Bressancourt has entirely
vanished since the surrounding forest-grounds were brought under
cultivation.
"The Wolf Spring, in the commune of Soubey, furnishes a remarkable
example of the influence of the woods upon fountains. A few years ago this
spring did not exist. At the place where it now rises, a small thread of water
was observed after very long rains, but the stream disappeared with the rain.
The spot is in the middle of a very steep pasture inclining to the south.
Eighty years ago, the owner of the land, perceiving that young firs were
shooting up in the upper part of it, determined to let them grow, and they
soon formed a flourishing grove. As soon as they were well grown, a fine
spring appeared in place of the occasional rill, and furnished abundant
its power was abundant, and had, from time immemorial, sufficed for the
machinery of a previous factory. Afterwards, the woods near its sources
were cut. The supply of water fell off in consequence, the factory wanted
water for half the year, and was at last obliged to stop altogether.
"The spring of Combefoulat, in the commune of Seleate, was well known
as one of the best in the country; it was remarkably abundant, and
sufficient, in the severest droughts, to supply all the fountains of the town;
but as soon as considerable forests were felled in Combe-de-pre Martin and
in the valley of Combefoulat, the famous spring, which lies below these
woods, has become a mere thread of water, and disappears altogether in
times of drought.
"The spring of Varieux, which formerly supplied the castle of Pruntrut,
lost more than half its water after the clearing of Varieux and Rougeoles.
These woods have been replanted, the young trees are growing well, and,
with the woods, the waters of the spring are increasing.
"The Dog Spring between Pruntrut and Bressancourt has entirely
vanished since the surrounding forest-grounds were brought under
cultivation.
"The Wolf Spring, in the commune of Soubey, furnishes a remarkable
example of the influence of the woods upon fountains. A few years ago this
spring did not exist. At the place where it now rises, a small thread of water
was observed after very long rains, but the stream disappeared with the rain.
The spot is in the middle of a very steep pasture inclining to the south.
Eighty years ago, the owner of the land, perceiving that young firs were
shooting up in the upper part of it, determined to let them grow, and they
soon formed a flourishing grove. As soon as they were well grown, a fine
spring appeared in place of the occasional rill, and furnished abundant
Page 295
water in the longest droughts. For forty or fifty years this spring was
considered the best in the Clos du Doubs. A few years since, the grove was
felled, and the ground turned again to a pasture. The spring disappeared
with the wood, and is now as dry as it was ninety years ago." [Footnote:
Ueber Die Entwaldung Der Gebirge, pp. 20 et seqq.]
Siemoni gives the following remarkable facts from his own personal
observation:
"In a rocky nook near the crest of a mountain in the Tuscan Apennines,
there flowed a clear, cool, and perennial fountain, uniting three distinct
springs in a single current. The ancient beeches around and particularly
above the springs were felled. On the disappearance of the wood, the
springs ceased to flow, except in a thread of water in rainy weather, greatly
inferior in quality to that of the old fountain. The beeches were succeeded
by firs, and as soon as they had grown sufficiently to shade the soil, the
springs begun again to flow, and they gradually returned to their former
abundance and quality." [Footnote: Manuale D'arte Forestale. 2me editione,
p. 492.]
This and the next preceding case are of great importance both as to the
action of the wood in maintaining springs, and particularly as tending to
prove that evergreens do not exercise the desiccative influence ascribed to
them in France. The latter instance shows, too, that the protective influence
of the wood extends far below the surface, for the quality of the water was
determined, no doubt, by the depth from which it was drawn. The slender
occasional supply after the beeches were cut was rain-water which soaked
through the superficial humus and oozed out at the old orifices, carrying the
taste and temperature of the vegetable soil with it; the more abundant and
grateful water which flowed before the beeches were cut, and after the firs
were well grown, came from a deeper source and had been purified, and
considered the best in the Clos du Doubs. A few years since, the grove was
felled, and the ground turned again to a pasture. The spring disappeared
with the wood, and is now as dry as it was ninety years ago." [Footnote:
Ueber Die Entwaldung Der Gebirge, pp. 20 et seqq.]
Siemoni gives the following remarkable facts from his own personal
observation:
"In a rocky nook near the crest of a mountain in the Tuscan Apennines,
there flowed a clear, cool, and perennial fountain, uniting three distinct
springs in a single current. The ancient beeches around and particularly
above the springs were felled. On the disappearance of the wood, the
springs ceased to flow, except in a thread of water in rainy weather, greatly
inferior in quality to that of the old fountain. The beeches were succeeded
by firs, and as soon as they had grown sufficiently to shade the soil, the
springs begun again to flow, and they gradually returned to their former
abundance and quality." [Footnote: Manuale D'arte Forestale. 2me editione,
p. 492.]
This and the next preceding case are of great importance both as to the
action of the wood in maintaining springs, and particularly as tending to
prove that evergreens do not exercise the desiccative influence ascribed to
them in France. The latter instance shows, too, that the protective influence
of the wood extends far below the surface, for the quality of the water was
determined, no doubt, by the depth from which it was drawn. The slender
occasional supply after the beeches were cut was rain-water which soaked
through the superficial humus and oozed out at the old orifices, carrying the
taste and temperature of the vegetable soil with it; the more abundant and
grateful water which flowed before the beeches were cut, and after the firs
were well grown, came from a deeper source and had been purified, and
Page 296
cooled to the mean temperature of the locality, by filtering through strata of
mineral earth. "The influence of the forest on springs," says Hummel, "is
strikingly shown by an instance at Heilbronn. The woods on the hills
surrounding the town are cut in regular succession every twentieth year. As
the annual cuttings approach a certain point, the springs yield less water,
some of them none at all; but as the young growth shoots up, they flow
more and more freely, and at length bubble up again in all their original
abundance." [Footnote: Physische Geographie, p. 32.] Dr. Piper states the
following case: "Within about half a mile of my residence there is a pond
upon which mills have been standing for a long time, dating back, I believe,
to the first settlement of the town. These have been kept in constant
operation until within some twenty or thirty years, when the supply of water
began to fail. The pond owes its existence to a stream that has its source in
the hills which stretch some miles to the south. Within the time mentioned,
these hills, which were clothed with a dense forest, have been almost
entirely stripped of trees; and to the wonder and loss of the mill-owners, the
water in the pond has failed, except in the season of freshets; and, what was
never heard of before, the stream itself has been entirely dry. Within the last
ten years a new growth of wood has sprung up on most of the land formerly
occupied by the old forest; and now the water runs through the year,
notwithstanding the great droughts of the last few years, going back from
1856."
Dr. Piper quotes from a letter of William C. Bryant the following
remarks: "It is a common observation that our summers are becoming drier
and our streams smaller. Take the Cuyahoga as an illustration. Fifty years
ago large barges loaded with goods went up and down that river, and one of
the vessels engaged in the battle of Lake Erie, in which the gallant Perry
was victorious, was built at Old Portage, six miles north of Albion, and
floated down to the lake. Now, in an ordinary stage of the water, a canoe or
skiff can hardly pass down the stream. Many a boat of fifty tons burden has
mineral earth. "The influence of the forest on springs," says Hummel, "is
strikingly shown by an instance at Heilbronn. The woods on the hills
surrounding the town are cut in regular succession every twentieth year. As
the annual cuttings approach a certain point, the springs yield less water,
some of them none at all; but as the young growth shoots up, they flow
more and more freely, and at length bubble up again in all their original
abundance." [Footnote: Physische Geographie, p. 32.] Dr. Piper states the
following case: "Within about half a mile of my residence there is a pond
upon which mills have been standing for a long time, dating back, I believe,
to the first settlement of the town. These have been kept in constant
operation until within some twenty or thirty years, when the supply of water
began to fail. The pond owes its existence to a stream that has its source in
the hills which stretch some miles to the south. Within the time mentioned,
these hills, which were clothed with a dense forest, have been almost
entirely stripped of trees; and to the wonder and loss of the mill-owners, the
water in the pond has failed, except in the season of freshets; and, what was
never heard of before, the stream itself has been entirely dry. Within the last
ten years a new growth of wood has sprung up on most of the land formerly
occupied by the old forest; and now the water runs through the year,
notwithstanding the great droughts of the last few years, going back from
1856."
Dr. Piper quotes from a letter of William C. Bryant the following
remarks: "It is a common observation that our summers are becoming drier
and our streams smaller. Take the Cuyahoga as an illustration. Fifty years
ago large barges loaded with goods went up and down that river, and one of
the vessels engaged in the battle of Lake Erie, in which the gallant Perry
was victorious, was built at Old Portage, six miles north of Albion, and
floated down to the lake. Now, in an ordinary stage of the water, a canoe or
skiff can hardly pass down the stream. Many a boat of fifty tons burden has
Page 297
been built and loaded in the Tuscarawas, at New Portage, and sailed to New
Orleans without breaking bulk. Now, the river hardly affords a supply of
water at New Portage for the canal. The same may be said of other streams
—they are drying up. And from the same cause—the destruction of our
forests—our summers are growing drier and our winters colder." [Footnote:
The Trees of America, pp. 50, 51.]
No observer has more carefully studied the influence of the forest upon
the flow of the waters, or reasoned more ably on the ascertained
phenomena, than Cantegril. The facts presented in the following case,
communicated by him to the Ami des Sciences for December, 1859, are as
nearly conclusive as any single instance well can be:
"In the territory of the commune of Labruguiere there is a forest of 1,834
hectares [4,530 acres], known by the name of the Forest of Montaut, and
belonging to that commune. It extends along thenorthern slope of the Black
Mountains. The soil is granitic, the maximum altitude 1,243 metres [4,140
feet], and the inclination ranges between 15 and 60 to 100.
"A small current of water, the brook of Caunan, takes its rise in this
forest, and receives the waters of two-thirds of its surface. At the lower
extremity of the wood and on the stream are several fulleries, each requiring
a force of eight horse-power to drive the water-wheels which work the
stampers. The commune of Labruguiere had been for a long time famous
for its opposition to forest laws. Trespasses and abuses of the right of
pasturage had converted the wood into an immense waste, so that this vast
property now scarcely sufficed to pay the expense of protecting it, and to
furnish the inhabitants with a meagre supply of fuel. While the forest was
thus ruined, and the soil thus bared, the water, after every abundant rain,
made an eruption into the valley, bringing down a great quantity of pebbles
which still clog the current of the Caunan. The violence of the floods was
Orleans without breaking bulk. Now, the river hardly affords a supply of
water at New Portage for the canal. The same may be said of other streams
—they are drying up. And from the same cause—the destruction of our
forests—our summers are growing drier and our winters colder." [Footnote:
The Trees of America, pp. 50, 51.]
No observer has more carefully studied the influence of the forest upon
the flow of the waters, or reasoned more ably on the ascertained
phenomena, than Cantegril. The facts presented in the following case,
communicated by him to the Ami des Sciences for December, 1859, are as
nearly conclusive as any single instance well can be:
"In the territory of the commune of Labruguiere there is a forest of 1,834
hectares [4,530 acres], known by the name of the Forest of Montaut, and
belonging to that commune. It extends along thenorthern slope of the Black
Mountains. The soil is granitic, the maximum altitude 1,243 metres [4,140
feet], and the inclination ranges between 15 and 60 to 100.
"A small current of water, the brook of Caunan, takes its rise in this
forest, and receives the waters of two-thirds of its surface. At the lower
extremity of the wood and on the stream are several fulleries, each requiring
a force of eight horse-power to drive the water-wheels which work the
stampers. The commune of Labruguiere had been for a long time famous
for its opposition to forest laws. Trespasses and abuses of the right of
pasturage had converted the wood into an immense waste, so that this vast
property now scarcely sufficed to pay the expense of protecting it, and to
furnish the inhabitants with a meagre supply of fuel. While the forest was
thus ruined, and the soil thus bared, the water, after every abundant rain,
made an eruption into the valley, bringing down a great quantity of pebbles
which still clog the current of the Caunan. The violence of the floods was
Page 298
sometimes such that they were obliged to stop the machinery for some time.
During the summer another inconvenience was felt. If the dry weather
continued a little longer than usual, the delivery of water became
insignificant. Each fullery could for the most part only employ a single set
of stampers, and it was not unusual to see the work entirely suspended.
"After 1840, the municipal authority succeeded in enlightening the
population as to their true interests. Protected by a more watchful
supervision, aided by well-managed replantation, the forest has continued to
improve to the present day. In proportion to the restoration of the forest, the
condition of the manufactories has become less and less precarious, and the
action of the water is completely modified. For example, sudden and violent
floods, which formerly made it necessary to stop the machinery, no longer
occur. There is no increase in the delivery until six or eight hours after the
beginning of the rain; the floods follow a regular progression till they reach
their maximum, and decrease in the same manner. Finally, the fulleries are
no longer forced to suspend work in summer; the water is always
sufficiently abundant to allow the employment of two sets of stampere at
least, and often even of three.
"This example is remarkable in this respect, that, all other circumstances
having remained the same, the changes in the action of the stream can be
attributed only to the restoration of the forest—changes which may be thus
summed up: diminution of flood-water during rains—increase of delivery at
other seasons."
Becquerel and other European writers adduce numerous other cases
where the destruction of forests has caused the disappearance of springs, a
diminution in the volume of rivers, and a lowering of the level of lakes, and
in fact, the evidence in support of the doctrine I have been maintaining on
this subject seems to be as conclusive as the nature of the case admits.
During the summer another inconvenience was felt. If the dry weather
continued a little longer than usual, the delivery of water became
insignificant. Each fullery could for the most part only employ a single set
of stampers, and it was not unusual to see the work entirely suspended.
"After 1840, the municipal authority succeeded in enlightening the
population as to their true interests. Protected by a more watchful
supervision, aided by well-managed replantation, the forest has continued to
improve to the present day. In proportion to the restoration of the forest, the
condition of the manufactories has become less and less precarious, and the
action of the water is completely modified. For example, sudden and violent
floods, which formerly made it necessary to stop the machinery, no longer
occur. There is no increase in the delivery until six or eight hours after the
beginning of the rain; the floods follow a regular progression till they reach
their maximum, and decrease in the same manner. Finally, the fulleries are
no longer forced to suspend work in summer; the water is always
sufficiently abundant to allow the employment of two sets of stampere at
least, and often even of three.
"This example is remarkable in this respect, that, all other circumstances
having remained the same, the changes in the action of the stream can be
attributed only to the restoration of the forest—changes which may be thus
summed up: diminution of flood-water during rains—increase of delivery at
other seasons."
Becquerel and other European writers adduce numerous other cases
where the destruction of forests has caused the disappearance of springs, a
diminution in the volume of rivers, and a lowering of the level of lakes, and
in fact, the evidence in support of the doctrine I have been maintaining on
this subject seems to be as conclusive as the nature of the case admits.
Page 299
[Footnote: See, in the Revue des Eaux et Forets for April, 1867, an article
entitled De l'influence des Forets sur le Regime des Eaux, and the papers in
previous numbers of the same journal therein referred to.] We cannot, it is
true, arrive at the same certainty and precision of result in these inquiries as
in those branches of physical research where exact quantitative appreciation
is possible, and we must content ourselves with probabilities and
approximations. We cannot positively affirm that the precipitation in a
given locality is increased by the presence, or lessened by the destruction,
of the forest, and from our ignorance of the subterranean circulation of the
waters, we cannot predict, with certainty, the drying up of a particular
spring as a consequence of the felling of the wood which shelters it; but the
general truth, that the flow of springs and the normal volume of rivers rise
and fall with the extension and the diminution of the woods where they
originate and through which they run, is as well established as any
proposition in the science of physical geography. [Footnote: Some years
ago it was popularly believed that the volume of the Mississippi, like that of
the Volga and other rivers of the Eastern Hemisphere, was diminished by
the increased evaporation from its basin and the drying up of the springs in
consequence of the felling of the forests in the vicinity of the source of its
eastern affluents. The boatmen of this great river and other intelligent
observers now assure us, however, that the mean and normal level of the
Mississippi has risen within a few years, and that in consequence the river
is navigable at low water for boats of greater draught and at higher points in
its course than was the case twenty-five years ago. This supposed increase
of volume has been attributed by some to the recent re-wooding of the
prairies, but the plantations thus far made are not yet sufficiently extensive
to produce an appreciable effect of this nature; and besides, while young
trees have covered some of the prairies, the destruction of the forest has
been continued perhaps in a greater proportion in other parts of the basin of
the river. A more plausible opinion is that the substitution of ground that is
entitled De l'influence des Forets sur le Regime des Eaux, and the papers in
previous numbers of the same journal therein referred to.] We cannot, it is
true, arrive at the same certainty and precision of result in these inquiries as
in those branches of physical research where exact quantitative appreciation
is possible, and we must content ourselves with probabilities and
approximations. We cannot positively affirm that the precipitation in a
given locality is increased by the presence, or lessened by the destruction,
of the forest, and from our ignorance of the subterranean circulation of the
waters, we cannot predict, with certainty, the drying up of a particular
spring as a consequence of the felling of the wood which shelters it; but the
general truth, that the flow of springs and the normal volume of rivers rise
and fall with the extension and the diminution of the woods where they
originate and through which they run, is as well established as any
proposition in the science of physical geography. [Footnote: Some years
ago it was popularly believed that the volume of the Mississippi, like that of
the Volga and other rivers of the Eastern Hemisphere, was diminished by
the increased evaporation from its basin and the drying up of the springs in
consequence of the felling of the forests in the vicinity of the source of its
eastern affluents. The boatmen of this great river and other intelligent
observers now assure us, however, that the mean and normal level of the
Mississippi has risen within a few years, and that in consequence the river
is navigable at low water for boats of greater draught and at higher points in
its course than was the case twenty-five years ago. This supposed increase
of volume has been attributed by some to the recent re-wooding of the
prairies, but the plantations thus far made are not yet sufficiently extensive
to produce an appreciable effect of this nature; and besides, while young
trees have covered some of the prairies, the destruction of the forest has
been continued perhaps in a greater proportion in other parts of the basin of
the river. A more plausible opinion is that the substitution of ground that is
Page 300
cultivated, and consequently spongy and absorbent, for the natural soil of
the prairies, has furnished a reservoir for the rains which are absorbed by
the earth and carried gradually to the river by subterranean flow, instead of
running off rapidly from the surface, or, as is more probable, instead of
evaporating or being taken up by the vigorous herbaceous vegetation which
covers the natural prairie.
A phenomenon so contrary to common experience, as would be a
permanent increase in the waters of a great river, will not be accepted
without the most convincing proofs. The present greater facility of
navigation may be attributed to improvements in the model of the boats, to
the removing of sand-banks and other impediments to the flow of the
waters, or to the confining of these waters in a narrower channel, by
extending the embankments of the river, or to yet other causes. So
remarkable a change could not have escaped the notice of Humphreys and
Abbot, whose most able labors comprise the years 1850-1861, had it
occurred during that period or at any former time within the knowledge of
the many observers they consulted; but no such fact is noticed in their
exhaustive report. However, even if an increase in the volume of the
Mississippi, for a period of ten or twenty years, were certain, it would still
be premature to consider this increase as normal and constant, since it might
very well be produced by causes yet unknown and analogous to those
which influence the mysterious advance and retreat of those Alpine ice-
rivers, the glaciers. Among such causes we may suppose a long series of
rainy seasons in regions where important tributaries have their far-off and
almost unknown sources; and with no less probability, we may conceive of
the opening of communications with great subterranean reservoirs, which
may from year to year empty large quantities of water into the bed of the
stream; or the closing up of orifices through which a considerable portion of
the water of the river once made its way for the supply of such reservoirs.—
See upon this point, Chap. IV., Of Subterranean Waters; post.]
the prairies, has furnished a reservoir for the rains which are absorbed by
the earth and carried gradually to the river by subterranean flow, instead of
running off rapidly from the surface, or, as is more probable, instead of
evaporating or being taken up by the vigorous herbaceous vegetation which
covers the natural prairie.
A phenomenon so contrary to common experience, as would be a
permanent increase in the waters of a great river, will not be accepted
without the most convincing proofs. The present greater facility of
navigation may be attributed to improvements in the model of the boats, to
the removing of sand-banks and other impediments to the flow of the
waters, or to the confining of these waters in a narrower channel, by
extending the embankments of the river, or to yet other causes. So
remarkable a change could not have escaped the notice of Humphreys and
Abbot, whose most able labors comprise the years 1850-1861, had it
occurred during that period or at any former time within the knowledge of
the many observers they consulted; but no such fact is noticed in their
exhaustive report. However, even if an increase in the volume of the
Mississippi, for a period of ten or twenty years, were certain, it would still
be premature to consider this increase as normal and constant, since it might
very well be produced by causes yet unknown and analogous to those
which influence the mysterious advance and retreat of those Alpine ice-
rivers, the glaciers. Among such causes we may suppose a long series of
rainy seasons in regions where important tributaries have their far-off and
almost unknown sources; and with no less probability, we may conceive of
the opening of communications with great subterranean reservoirs, which
may from year to year empty large quantities of water into the bed of the
stream; or the closing up of orifices through which a considerable portion of
the water of the river once made its way for the supply of such reservoirs.—
See upon this point, Chap. IV., Of Subterranean Waters; post.]
Page 301
Of the converse proposition, namely, that the planting of new forests
gives rise to new springs and restores the regular flow of rivers, I find less
of positive proof, however probable it may be that such effects would
follow. [Footnote: According to the Report of the Department of Agriculture
for February, 1872, it is thought in the Far West that the young plantations
have already influenced the water-courses in that region, and it is alleged
that ancient river-beds, never known to contain water since the settlement of
the country, have begun to flow since these plantations were commenced.
See also Hayden, Report on Geological Survey of Wyoming, 1870, p. 104,
and Bryant. Forest Trees, 1871, chap. iv.
In the Voyage autour du Monde of the Comte da Beauvoir, chap. x., this
passage occurs: Dr. Muller, Director of the Botanic Garden at Melbourne,
"has distributed through the interior of Australia millions of seedling trees
from his nursuries. Small rivulets are soon formed under the young wood;
the results are superb, and the observation of every successive year
confirms them. On bare soils he has created, at more than a hundred points,
forests and water-courses."] A reason for the want of evidence on the
subject may be, that, under ordinary circumstances, the process of
conversion of bare ground to soil with a well-wooded surface is so gradual
and slow, and the time required for a fair experiment is consequently so
long, that many changes produced by the action of the new geographical
element escape the notice and the memory of ordinary observers. The
growth of a forest, including the formation of a thick stratum of vegetable
mould beneath it, is the work of a generation, its destruction may be
accomplished in a day; and hence, while the results of the one process may,
for a considerable time, be doubtful if not imperceptible, those of the other
are immediate and readily appreciable. Fortunately, the plantation of a wood
produces other beneficial consequences which are both sooner realized and
more easily estimated; and though he who drops the seed is sowing for a
gives rise to new springs and restores the regular flow of rivers, I find less
of positive proof, however probable it may be that such effects would
follow. [Footnote: According to the Report of the Department of Agriculture
for February, 1872, it is thought in the Far West that the young plantations
have already influenced the water-courses in that region, and it is alleged
that ancient river-beds, never known to contain water since the settlement of
the country, have begun to flow since these plantations were commenced.
See also Hayden, Report on Geological Survey of Wyoming, 1870, p. 104,
and Bryant. Forest Trees, 1871, chap. iv.
In the Voyage autour du Monde of the Comte da Beauvoir, chap. x., this
passage occurs: Dr. Muller, Director of the Botanic Garden at Melbourne,
"has distributed through the interior of Australia millions of seedling trees
from his nursuries. Small rivulets are soon formed under the young wood;
the results are superb, and the observation of every successive year
confirms them. On bare soils he has created, at more than a hundred points,
forests and water-courses."] A reason for the want of evidence on the
subject may be, that, under ordinary circumstances, the process of
conversion of bare ground to soil with a well-wooded surface is so gradual
and slow, and the time required for a fair experiment is consequently so
long, that many changes produced by the action of the new geographical
element escape the notice and the memory of ordinary observers. The
growth of a forest, including the formation of a thick stratum of vegetable
mould beneath it, is the work of a generation, its destruction may be
accomplished in a day; and hence, while the results of the one process may,
for a considerable time, be doubtful if not imperceptible, those of the other
are immediate and readily appreciable. Fortunately, the plantation of a wood
produces other beneficial consequences which are both sooner realized and
more easily estimated; and though he who drops the seed is sowing for a
Page 302
future generation as well as for his own, the planter of a grove may hope
himself to reap a fair return for his expenditure and his labor.
Influence of the Forest on Inundations and Torrents.
Inasmuch as it is not yet proved that the forests augment or diminish the
precipitation in the regions they principally cover, we cannot positively
affirm that their presence or absence increases or lessens the total volume of
the water annually delivered by great rivers or by mountain torrents. It is
nevertheless certain that they exercise an action on the discharge of the
water of rain and snow into the valleys, ravines, and other depressions of
the surface, where it is gathered into brooks and finally larger currents, and
consequently influence the character of floods, both in rivers and in
torrents. For this reason, river inundations and the devastations of torrents,
and the geographical effects resulting from them, so far as they are
occasioned or modified by the action of forests or of the destruction of the
woods, may properly be discussed in this chapter, though they might seem
otherwise to belong more appropriately to another division of this work.
Besides the climatic question, which I have already sufficiently
discussed, and the obvious inconveniences of a scanty supply of charcoal,
of fuel, and of timber for architectural and naval construction and for the
thousand other uses to which wood is applied in rural and domestic
economy, and in the various industrial processes of civilized life, the
attention of European foresters and public economists has been specially
drawn to three points, namely: the influence of the forests on the
permanence and regular flow of springs or natural fountains; on inundations
by the overflow of rivers; and on the abrasion of soil and the transportation
of earth, gravel, pebbles, and even of considerable masses of rock, from
higher to lower levels, by torrents. There are, however, connected with this
general subject, several other topics of minor or strictly local interest, or of
himself to reap a fair return for his expenditure and his labor.
Influence of the Forest on Inundations and Torrents.
Inasmuch as it is not yet proved that the forests augment or diminish the
precipitation in the regions they principally cover, we cannot positively
affirm that their presence or absence increases or lessens the total volume of
the water annually delivered by great rivers or by mountain torrents. It is
nevertheless certain that they exercise an action on the discharge of the
water of rain and snow into the valleys, ravines, and other depressions of
the surface, where it is gathered into brooks and finally larger currents, and
consequently influence the character of floods, both in rivers and in
torrents. For this reason, river inundations and the devastations of torrents,
and the geographical effects resulting from them, so far as they are
occasioned or modified by the action of forests or of the destruction of the
woods, may properly be discussed in this chapter, though they might seem
otherwise to belong more appropriately to another division of this work.
Besides the climatic question, which I have already sufficiently
discussed, and the obvious inconveniences of a scanty supply of charcoal,
of fuel, and of timber for architectural and naval construction and for the
thousand other uses to which wood is applied in rural and domestic
economy, and in the various industrial processes of civilized life, the
attention of European foresters and public economists has been specially
drawn to three points, namely: the influence of the forests on the
permanence and regular flow of springs or natural fountains; on inundations
by the overflow of rivers; and on the abrasion of soil and the transportation
of earth, gravel, pebbles, and even of considerable masses of rock, from
higher to lower levels, by torrents. There are, however, connected with this
general subject, several other topics of minor or strictly local interest, or of
Page 303
more uncertain character, which I shall have occasion more fully to speak of
hereafter.
The first of these three principal subjects—the influence of the woods on
springs and other living waters—has been already considered; and if the
facts stated in that discussion are well established, and the conclusions I
have drawn from them are logically sound, it would seem to follow, as a
necessary corollary, that the action of the forest is as important in
diminishing the frequency and violence of river-floods as in securing the
permanence and equability of natural fountains; for any cause which
promotes the absorption and accumulation of the water of precipitation by
the superficial strata of the soil, to be slowly given out by infiltration and
percolation, must, by preventing the rapid flow of surface-water into the
natural channels of drainage, tend to check the sudden rise of rivers, and,
consequently, the overflow of their banks, which constitutes what is called
inundation.
The surface of a forest, in its natural condition, can never pour forth such
deluges of water as flow from cultivated soil. Humus, or vegetable mould,
is capable of absorbing almost twice its own weight of water. The soil in a
forest of deciduous foliage is composed of humus, more or less unmixed, to
the depth of several inches, sometimes even of feet, and this stratum is
usually able to imbibe all the water possibly resulting from the snow which
at any one time covers, or the rain which in any one shower falls upon it.
But the vegetable mould does not cease to absorb water when it becomes
saturated, for it then gives off a portion of its moisture to the mineral earth
below, and thus is ready to receive a new supply; and, besides, the bed of
leaves not yet converted to mould takes up and retains a very considerable
proportion of snow-water, as well as of rain.
hereafter.
The first of these three principal subjects—the influence of the woods on
springs and other living waters—has been already considered; and if the
facts stated in that discussion are well established, and the conclusions I
have drawn from them are logically sound, it would seem to follow, as a
necessary corollary, that the action of the forest is as important in
diminishing the frequency and violence of river-floods as in securing the
permanence and equability of natural fountains; for any cause which
promotes the absorption and accumulation of the water of precipitation by
the superficial strata of the soil, to be slowly given out by infiltration and
percolation, must, by preventing the rapid flow of surface-water into the
natural channels of drainage, tend to check the sudden rise of rivers, and,
consequently, the overflow of their banks, which constitutes what is called
inundation.
The surface of a forest, in its natural condition, can never pour forth such
deluges of water as flow from cultivated soil. Humus, or vegetable mould,
is capable of absorbing almost twice its own weight of water. The soil in a
forest of deciduous foliage is composed of humus, more or less unmixed, to
the depth of several inches, sometimes even of feet, and this stratum is
usually able to imbibe all the water possibly resulting from the snow which
at any one time covers, or the rain which in any one shower falls upon it.
But the vegetable mould does not cease to absorb water when it becomes
saturated, for it then gives off a portion of its moisture to the mineral earth
below, and thus is ready to receive a new supply; and, besides, the bed of
leaves not yet converted to mould takes up and retains a very considerable
proportion of snow-water, as well as of rain.
Page 304
The stems of trees, too, and of underwood, the trunks and stumps and
roots of fallen timber, the mosses and fungi and the numerous inequalities
of the ground observed in all forests, oppose a mechanical resistance to the
flow of water over the surface, which sensibly retards the rapidity of its
descent down declivities, and diverts and divides streams which may have
already accumulated from smaller threads of water. [Footnote: In a letter
addressed to the Minister of Public Works, after the terrible inundations of
1857, the late Emperor of France thus happily expressed himself: "Before
we seek the remedy for an evil, we inquire into its cause. Whence come the
sudden floods of our rivers From the water which falls on the mountains,
not from that which falls on the plains. The waters which fall on our fields
produce but few rivulets, but these which fall on our roofs and are collected
in the gutters, form small streams at once. Now, the roofs are mountains—
the gutters are valleys."
"To continue the comparison," observes D'Hericourt, "roofs are smooth
and impermeable, and the rain-water pours rapidly off from their surfaces;
but this rapidity of flow would be greatly diminished if the roofs were
carpeted with mosses and grasses; more still, if they were covered with dry
leaves, little shrubs, strewn branches, and other impediments—in short, if
they were wooded."—Annales Forestieres, Dec. 1857, p. 311.
The mosses and fungi play a more important part in regulating the
humidity of the air and of the soil than writers on the forest have usually
assigned to them. They perish with the trees they grow on; but, in many
situations, nature provides a compensation for the tree-mosses and fungi in
ground species, which, on cold soils, especially those with a northern
exposure, spring up abundantly both before the woods are felled, and when
the land is cleared and employed for pasturage, or deserted. These humble
plants discharge a portion of the functions appropriated to the wood, and
while they render the soil of improved lands much less fit for agricultural
roots of fallen timber, the mosses and fungi and the numerous inequalities
of the ground observed in all forests, oppose a mechanical resistance to the
flow of water over the surface, which sensibly retards the rapidity of its
descent down declivities, and diverts and divides streams which may have
already accumulated from smaller threads of water. [Footnote: In a letter
addressed to the Minister of Public Works, after the terrible inundations of
1857, the late Emperor of France thus happily expressed himself: "Before
we seek the remedy for an evil, we inquire into its cause. Whence come the
sudden floods of our rivers From the water which falls on the mountains,
not from that which falls on the plains. The waters which fall on our fields
produce but few rivulets, but these which fall on our roofs and are collected
in the gutters, form small streams at once. Now, the roofs are mountains—
the gutters are valleys."
"To continue the comparison," observes D'Hericourt, "roofs are smooth
and impermeable, and the rain-water pours rapidly off from their surfaces;
but this rapidity of flow would be greatly diminished if the roofs were
carpeted with mosses and grasses; more still, if they were covered with dry
leaves, little shrubs, strewn branches, and other impediments—in short, if
they were wooded."—Annales Forestieres, Dec. 1857, p. 311.
The mosses and fungi play a more important part in regulating the
humidity of the air and of the soil than writers on the forest have usually
assigned to them. They perish with the trees they grow on; but, in many
situations, nature provides a compensation for the tree-mosses and fungi in
ground species, which, on cold soils, especially those with a northern
exposure, spring up abundantly both before the woods are felled, and when
the land is cleared and employed for pasturage, or deserted. These humble
plants discharge a portion of the functions appropriated to the wood, and
while they render the soil of improved lands much less fit for agricultural
Page 305
use, they, at the same time, prepare it for the growth of a new harvest of
trees, when the infertility they produce shall have driven man to abandon it
and suffer it to relapse into the hands of nature.
In primitive forests, when the ground is not too moist to admit of a dense
growth of trees, the soil is generally so thickly covered with leaves that
there is little room for ground mosses and mushrooms. In the more open
artificial woods of Europe these forms of vegetation, as well as many more
attractive plants, are more frequent than in the native groves of America.
See, on cryptogamic and other wood plants, Rossmassler, Der Wald, pp. 82
et seqq., and on the importance of such vegetables in checking the flow of
water, Mengotti, Idraulica Fisica e Sperimentale, chapters xvi. and xvii. No
writer known to me has so well illustrated this function of forest vegetation
as Mengotti, though both he and Rossmassler ascribe to plants a power of
absorbing water from the atmosphere which they do not possess, or rather
can only rarely exercise.]
The value of the forest as a mechanical check to a too rapid discharge of
rain-water was exemplified in numerous instances in the great floods of
1866 and 1868, in France and Switzerland, and I refer to the observations
made on those occasions as of special importance because no previous
inundations in those countries had been so carefully watched and so well
described by competent investigators. In the French Department of Lozere,
which was among those most severely injured by the inundation of 1866—
an inundation caused by diluvial rains, not by melted snow—it was
everywhere remarked that "grounds covered with wood sustained no
damage even on the steepest slopes, while in cleared and cultivated fields
the very soil was washed away and the rocks laid bare by the pouring rain."
[Footnote: See, for other like observations, an article entitled Le
Reboisement et les Inondations, in the Revue des Eaux et Forets of
September, 1868]
trees, when the infertility they produce shall have driven man to abandon it
and suffer it to relapse into the hands of nature.
In primitive forests, when the ground is not too moist to admit of a dense
growth of trees, the soil is generally so thickly covered with leaves that
there is little room for ground mosses and mushrooms. In the more open
artificial woods of Europe these forms of vegetation, as well as many more
attractive plants, are more frequent than in the native groves of America.
See, on cryptogamic and other wood plants, Rossmassler, Der Wald, pp. 82
et seqq., and on the importance of such vegetables in checking the flow of
water, Mengotti, Idraulica Fisica e Sperimentale, chapters xvi. and xvii. No
writer known to me has so well illustrated this function of forest vegetation
as Mengotti, though both he and Rossmassler ascribe to plants a power of
absorbing water from the atmosphere which they do not possess, or rather
can only rarely exercise.]
The value of the forest as a mechanical check to a too rapid discharge of
rain-water was exemplified in numerous instances in the great floods of
1866 and 1868, in France and Switzerland, and I refer to the observations
made on those occasions as of special importance because no previous
inundations in those countries had been so carefully watched and so well
described by competent investigators. In the French Department of Lozere,
which was among those most severely injured by the inundation of 1866—
an inundation caused by diluvial rains, not by melted snow—it was
everywhere remarked that "grounds covered with wood sustained no
damage even on the steepest slopes, while in cleared and cultivated fields
the very soil was washed away and the rocks laid bare by the pouring rain."
[Footnote: See, for other like observations, an article entitled Le
Reboisement et les Inondations, in the Revue des Eaux et Forets of
September, 1868]
Page 306
The Italian journals of the day state that the province of Brescia and a
part of that of Bergamo, which have heretofore been exposed to enormous
injury, after every heavy rain, from floods of the four principal streams
which traverse them, in a great degree escaped damage in the terrible
inundation of October, 1872, and their immunity is ascribed to the forestal
improvements executed by the former province, within ten or twelve years,
in the Val Camonica and in the upper basins of the other rivers which drain
that territory. Similar facts were noticed in the extraordinary floods of
September and October, 1868, in the valley of the Upper Rhine, and Coaz
makes the interesting observation that not even dense greensward was so
efficient a protection to the earth as trees, because the water soaked through
the sod and burst it up by hydrostatic pressure. [Footnote: Die Hochwasser
in 1868 im Bandnerischen Rheingebiet, pp. 12, 68.
Observations of Forster, cited by Cezanne from the Annales Forestieres
for 1859, p. 358, are not less important than those adduced in the text. The
field of these observations was a slope of 45 degrees divided into three
sections, one luxuriantly wooded from summit to base with oak and beech,
one completely cleared through its whole extent, and one cleared in its
upper portion, but retaining a wooded belt for a quarter of the height of the
slope, which was from 1,360 to 1,800 feet above the brook at its foot.
In the first section, comprising six-sevenths of the whole surface, the
rains had not produced a single ravine; in the second, occupying about a
tenth of the ground, were three ravines, increasing in width from the
summit to the valley beneath, where they had, all together, a cross-section
of 600 square feet; in the third section, of about the same extent as the
second, four ravines had been formed, widening from the crest of the slope
to the belt of wood, where they gradually narrowed and finally disappeared.
part of that of Bergamo, which have heretofore been exposed to enormous
injury, after every heavy rain, from floods of the four principal streams
which traverse them, in a great degree escaped damage in the terrible
inundation of October, 1872, and their immunity is ascribed to the forestal
improvements executed by the former province, within ten or twelve years,
in the Val Camonica and in the upper basins of the other rivers which drain
that territory. Similar facts were noticed in the extraordinary floods of
September and October, 1868, in the valley of the Upper Rhine, and Coaz
makes the interesting observation that not even dense greensward was so
efficient a protection to the earth as trees, because the water soaked through
the sod and burst it up by hydrostatic pressure. [Footnote: Die Hochwasser
in 1868 im Bandnerischen Rheingebiet, pp. 12, 68.
Observations of Forster, cited by Cezanne from the Annales Forestieres
for 1859, p. 358, are not less important than those adduced in the text. The
field of these observations was a slope of 45 degrees divided into three
sections, one luxuriantly wooded from summit to base with oak and beech,
one completely cleared through its whole extent, and one cleared in its
upper portion, but retaining a wooded belt for a quarter of the height of the
slope, which was from 1,360 to 1,800 feet above the brook at its foot.
In the first section, comprising six-sevenths of the whole surface, the
rains had not produced a single ravine; in the second, occupying about a
tenth of the ground, were three ravines, increasing in width from the
summit to the valley beneath, where they had, all together, a cross-section
of 600 square feet; in the third section, of about the same extent as the
second, four ravines had been formed, widening from the crest of the slope
to the belt of wood, where they gradually narrowed and finally disappeared.
Page 307
For important observations to the same purpose, see Marchand, Les
Torrents des Alpes, in Revue des Eaux et Forets for September, 1871.]
The importance of the mechanical resistance of the wood to the flow of
water OVER THE SURFACE has, however, been exaggerated by some
writers. Rain-water is generally absorbed by the forest-soil as fast as it falls,
and it is only in extreme cases that it gathers itself into a superficial sheet or
current overflowing the ground. There is, nevertheless, besides the
absorbent power of the soil, a very considerable mechanical resistance to
the transmission of water BENEATH the surface through and along the
superior strata of the ground. This resistance is exerted by the roots, which
both convey the water along their surface downwards, and oppose a closely
wattled barrier to its descent along the slope of the permeable strata which
have absorbed it. [Footnote: In a valuable report on a bill for compelling the
sale of waste communal lands, now pending in the Parliament of Italy,
Senator Torelli, an eminent man of science, calculates that four-fifths of the
precipitation in the forest are absorbed by the soil, or detained by the
obstructions of the surface, only one-fifth being delivered to the rivers
rapidly enough to create danger of floods, while in open grounds, in heavy
rains, the proportions are reversed. Supposing a rain-fall of four inches, an
area measuring 100,000 acres, or a little more than four American
townships, would receive 53,777,777 cubic yards of water. Of this quantity
it would retain, or rather detain, if wooded, 41,000,000 yards, if bare, only
11,000,000. The difference of discharge from wooded and unwooded soils
is perhaps exaggerated in Col. Torelli's report, but there is no doubt that in
very many cases it is great enough to prevent, or to cause, destructive
inundations.] Rivers fed by springs and shaded by woods are comparatively
uniform in volume, in temperature, and in chemical composition. [Footnote:
Dumont gives an interesting extract from the Misopogon of the Emperor
Julian, showing that, in the fourth century, the Seine—the level of which
now varies to the extent of thirty feet between extreme high and extreme
Torrents des Alpes, in Revue des Eaux et Forets for September, 1871.]
The importance of the mechanical resistance of the wood to the flow of
water OVER THE SURFACE has, however, been exaggerated by some
writers. Rain-water is generally absorbed by the forest-soil as fast as it falls,
and it is only in extreme cases that it gathers itself into a superficial sheet or
current overflowing the ground. There is, nevertheless, besides the
absorbent power of the soil, a very considerable mechanical resistance to
the transmission of water BENEATH the surface through and along the
superior strata of the ground. This resistance is exerted by the roots, which
both convey the water along their surface downwards, and oppose a closely
wattled barrier to its descent along the slope of the permeable strata which
have absorbed it. [Footnote: In a valuable report on a bill for compelling the
sale of waste communal lands, now pending in the Parliament of Italy,
Senator Torelli, an eminent man of science, calculates that four-fifths of the
precipitation in the forest are absorbed by the soil, or detained by the
obstructions of the surface, only one-fifth being delivered to the rivers
rapidly enough to create danger of floods, while in open grounds, in heavy
rains, the proportions are reversed. Supposing a rain-fall of four inches, an
area measuring 100,000 acres, or a little more than four American
townships, would receive 53,777,777 cubic yards of water. Of this quantity
it would retain, or rather detain, if wooded, 41,000,000 yards, if bare, only
11,000,000. The difference of discharge from wooded and unwooded soils
is perhaps exaggerated in Col. Torelli's report, but there is no doubt that in
very many cases it is great enough to prevent, or to cause, destructive
inundations.] Rivers fed by springs and shaded by woods are comparatively
uniform in volume, in temperature, and in chemical composition. [Footnote:
Dumont gives an interesting extract from the Misopogon of the Emperor
Julian, showing that, in the fourth century, the Seine—the level of which
now varies to the extent of thirty feet between extreme high and extreme
Page 308
low water mark—was almost wholly exempt from inundations, and flowed
with a uniform current through the whole year. "Ego olim eram in hibernis
apud curam Lutetiam, [sic] enim Galli Parisiorum oppidum appellant, quae
insula est non magna, in fluvio sita, qui eam omni ex parte cingit. Pontes
sublicii utrinque ad eam ferunt, raroque fluvius minuitur ac crescit; sed
qualis aestate talis esse solet hyeme."—Des Travaux Publics dans leur
Rapports avec l'Agriculture, p. 361, note.
As Julian was six years in Gaul, and his principal residence was at Paris,
his testimony as to the habitual condition of the Seine, at a period when the
provinces where its sources originate were well wooded, is very valuable.]
Their banks are little abraded, nor are their courses much obstructed by
fallen timber, or by earth and gravel washed down from the highlands.
Their channels are subject only to slow and gradual changes, and they carry
down to the lakes and the sea no accumulation of sand or silt to fill up their
outlets, and, by raising their beds, to force them to spread over the low
grounds near their mouth. [Footnote: Forest rivers seldom if ever form large
sedimentary deposits at their points of discharge into lakes or larger
streams, such accumulations beginning or at least advancing far more
rapidly, after the valleys are cleared.]
Causes of Inundations.
The immediate cause of river inundations is the flow of superficial and
subterranean waters into the beds of rivers faster than those channels can
discharge them. The insufficiency of the channels is occasioned partly by
their narrowness and partly by obstructions to their currents, the most
frequent of which is the deposit of sand, gravel, and pebbles in their beds by
torrential tributaries during the floods. [Footnote: The extent of the
overflow and the violence of the current in river- floods are much affected
by the amount of sedimentary matter let fall in their channels by their
with a uniform current through the whole year. "Ego olim eram in hibernis
apud curam Lutetiam, [sic] enim Galli Parisiorum oppidum appellant, quae
insula est non magna, in fluvio sita, qui eam omni ex parte cingit. Pontes
sublicii utrinque ad eam ferunt, raroque fluvius minuitur ac crescit; sed
qualis aestate talis esse solet hyeme."—Des Travaux Publics dans leur
Rapports avec l'Agriculture, p. 361, note.
As Julian was six years in Gaul, and his principal residence was at Paris,
his testimony as to the habitual condition of the Seine, at a period when the
provinces where its sources originate were well wooded, is very valuable.]
Their banks are little abraded, nor are their courses much obstructed by
fallen timber, or by earth and gravel washed down from the highlands.
Their channels are subject only to slow and gradual changes, and they carry
down to the lakes and the sea no accumulation of sand or silt to fill up their
outlets, and, by raising their beds, to force them to spread over the low
grounds near their mouth. [Footnote: Forest rivers seldom if ever form large
sedimentary deposits at their points of discharge into lakes or larger
streams, such accumulations beginning or at least advancing far more
rapidly, after the valleys are cleared.]
Causes of Inundations.
The immediate cause of river inundations is the flow of superficial and
subterranean waters into the beds of rivers faster than those channels can
discharge them. The insufficiency of the channels is occasioned partly by
their narrowness and partly by obstructions to their currents, the most
frequent of which is the deposit of sand, gravel, and pebbles in their beds by
torrential tributaries during the floods. [Footnote: The extent of the
overflow and the violence of the current in river- floods are much affected
by the amount of sedimentary matter let fall in their channels by their
Page 309
affluents, which have usually a swifter flow than the main stream, and
consequently deposit more or less of their transported material when they
join its more slowly-moving waters. Such deposits constitute barriers which
at first check the current and raise its level, and of course its violence at
lower points is augmented, both by increased volume and by the solid
material it carries with it, when it acquires force enough to sweep away the
obstruction.—Risler, Sur L influence des Forets sur les Cours d eau, in
Revue des Eaux et Forets, 10th January, 1870.
In the flood of 1868 the torrent Illgraben, which had formerly spread its
water and its sediment over the surface of a vast cone of dejection, having
been forced, by the injudicious confinement of its current to a single
channel, to discharge itself more directly into the Rhone, carried down a
quantity of gravel, sand, and mud, sufficient to dam that river for a whole
hour, and in the same great inundation the flow of the Rhine at Thusis was
completely arrested for twenty minutes by a similar discharge from the
Nolla. Of course, when the dam yielded to the pressure of the accumulated
water, the damage to the country below was far greater than it would have
ben had the currents of the rivers not been thus obstructed.—Marchand, Les
Torrents des Alpes, in Revue des Eaux et Forets, Sept., 1871.]
In accordance with the usual economy of nature, we should presume that
she had everywhere provided the means of discharging, without disturbance
of her general arrangements or abnormal destruction of her products, the
precipitation which she sheds upon the face of the earth. Observation
confirms this presumption, at least in the countries to which I confine my
inquiries; for, so far as we know the primitive conditions of the regions
brought under human occupation within the historical period, it appears that
the overflow of river-banks was much less frequent and destructive than at
the present day, or, at least, that rivers rose and fell less suddenly, before
man had removed the natural checks to the too rapid drainage of the basins
consequently deposit more or less of their transported material when they
join its more slowly-moving waters. Such deposits constitute barriers which
at first check the current and raise its level, and of course its violence at
lower points is augmented, both by increased volume and by the solid
material it carries with it, when it acquires force enough to sweep away the
obstruction.—Risler, Sur L influence des Forets sur les Cours d eau, in
Revue des Eaux et Forets, 10th January, 1870.
In the flood of 1868 the torrent Illgraben, which had formerly spread its
water and its sediment over the surface of a vast cone of dejection, having
been forced, by the injudicious confinement of its current to a single
channel, to discharge itself more directly into the Rhone, carried down a
quantity of gravel, sand, and mud, sufficient to dam that river for a whole
hour, and in the same great inundation the flow of the Rhine at Thusis was
completely arrested for twenty minutes by a similar discharge from the
Nolla. Of course, when the dam yielded to the pressure of the accumulated
water, the damage to the country below was far greater than it would have
ben had the currents of the rivers not been thus obstructed.—Marchand, Les
Torrents des Alpes, in Revue des Eaux et Forets, Sept., 1871.]
In accordance with the usual economy of nature, we should presume that
she had everywhere provided the means of discharging, without disturbance
of her general arrangements or abnormal destruction of her products, the
precipitation which she sheds upon the face of the earth. Observation
confirms this presumption, at least in the countries to which I confine my
inquiries; for, so far as we know the primitive conditions of the regions
brought under human occupation within the historical period, it appears that
the overflow of river-banks was much less frequent and destructive than at
the present day, or, at least, that rivers rose and fell less suddenly, before
man had removed the natural checks to the too rapid drainage of the basins
Page 310
in which their tributaries originate. The affluents of rivers draining wooded
basins generally transport, and of course let fall, little or no sediment, and
hence in such regions the special obstruction to the currents of water-
courses to which I have just alluded does not occur. The banks of the rivers
and smaller streams in the North American colonies were formerly little
abraded by the currents. [Footnote: In primitive countries, running streams
are very generally fringed by groves, for almost every river is, as Pliny, Nat.
Hist., v. 10, says of the Upper Nile, an opifex silvarum, or, to use the quaint
and picturesque language of Holland's translation, "makes shade of woods
as he goeth."] Even now the trees come down almost to the water's edge
along the rivers, in the larger forests of the United States, and the surface of
the streams seems liable to no great change in level or in rapidity of current.
[Footnote: A valuable memoir by G. Doni, in the Rivista Forestale for
October, 1863, p. 438, is one of the best illustrations I can cite of the
influence of forests in regulating and equalizing the flow of running water,
and of the comparative action of water-courses which drain wooded valleys
and valleys bared of trees, with regard to the erosion of their banks and the
transportation of sediment.
"The Sestajone," remarks this writer, "and the Lima, are two considerable
torrents which collect the waters of two great valleys of the Tuscan
Apennines, and empty them into the Serchio. At the junction of these two
torrents, from which point the combined current takes the name of Lima, a
curious phenomenon is observed, which is in part easily explained. In rainy
weather the waters of the Sestajone are in volume only about one-half those
of the Lima, and while the current of the Lima is turbid and muddy, that of
the Sestajone appears limpid and I might almost say drinkable. In clear
weather, on the contrary, the waters of the Sestajone are abundant and about
double those of the Lima. Now the extent of the two valleys is nearly equal,
but the Sestajone winds down between banks clothed with firs and beeches,
basins generally transport, and of course let fall, little or no sediment, and
hence in such regions the special obstruction to the currents of water-
courses to which I have just alluded does not occur. The banks of the rivers
and smaller streams in the North American colonies were formerly little
abraded by the currents. [Footnote: In primitive countries, running streams
are very generally fringed by groves, for almost every river is, as Pliny, Nat.
Hist., v. 10, says of the Upper Nile, an opifex silvarum, or, to use the quaint
and picturesque language of Holland's translation, "makes shade of woods
as he goeth."] Even now the trees come down almost to the water's edge
along the rivers, in the larger forests of the United States, and the surface of
the streams seems liable to no great change in level or in rapidity of current.
[Footnote: A valuable memoir by G. Doni, in the Rivista Forestale for
October, 1863, p. 438, is one of the best illustrations I can cite of the
influence of forests in regulating and equalizing the flow of running water,
and of the comparative action of water-courses which drain wooded valleys
and valleys bared of trees, with regard to the erosion of their banks and the
transportation of sediment.
"The Sestajone," remarks this writer, "and the Lima, are two considerable
torrents which collect the waters of two great valleys of the Tuscan
Apennines, and empty them into the Serchio. At the junction of these two
torrents, from which point the combined current takes the name of Lima, a
curious phenomenon is observed, which is in part easily explained. In rainy
weather the waters of the Sestajone are in volume only about one-half those
of the Lima, and while the current of the Lima is turbid and muddy, that of
the Sestajone appears limpid and I might almost say drinkable. In clear
weather, on the contrary, the waters of the Sestajone are abundant and about
double those of the Lima. Now the extent of the two valleys is nearly equal,
but the Sestajone winds down between banks clothed with firs and beeches,
Page 311
while the Lima flows through a valley that has been stripped of trees, and in
great part brought under cultivation."
The Sestajone and the Lima are neither of them what is technically
termed a torrent—a name strictly applicable only to streams whose current
is not derived from springs and perennial, but is the temporary effect of a
sudden accumulation of water from heavy rains or from a rapid melting of
the snows, while their beds are dry, or nearly so, at other times. The Lima,
however, in a large proportion of its course, has the erosive character of a
torrent, for the amount of sediment which it carries down, even when it is
only moderately swollen by rains, surpasses almost everything of the kind
which I have observed, under analogous circumstances, in Italy.
Still more striking is the contrast in the regime of the Saint-Phalez and
the Combe-d'Yeuse in the Department of Vancluse, the latter of which
became subject to the most violent torrential floods after the destruction of
the woods of its basin between 1823 and 1833, but has now been
completely subdued, and its waters brought to a peaceful flow, by
replanting its valley. See Labussiere, Revue Agric. et Forestiere de
Provence, 1866, and Revue des Eaux et Forets, 1866.]
Inundations in Winter.
In the Northern United States, although inundations are not very
unfrequently produced by heavy rains in the height of summer, it will be
found generally true that the most rapid rise of the waters, and, of course,
the most destructive "freshets," as they are called in America, are
occasioned by the sudden dissolution of the snow before the open ground is
thawed in the spring. It frequently happens that a powerful thaw sets in after
a long period of frost, and the snow which had been months in
accumulating is dissolved and carried off in a few hours. When the snow is
great part brought under cultivation."
The Sestajone and the Lima are neither of them what is technically
termed a torrent—a name strictly applicable only to streams whose current
is not derived from springs and perennial, but is the temporary effect of a
sudden accumulation of water from heavy rains or from a rapid melting of
the snows, while their beds are dry, or nearly so, at other times. The Lima,
however, in a large proportion of its course, has the erosive character of a
torrent, for the amount of sediment which it carries down, even when it is
only moderately swollen by rains, surpasses almost everything of the kind
which I have observed, under analogous circumstances, in Italy.
Still more striking is the contrast in the regime of the Saint-Phalez and
the Combe-d'Yeuse in the Department of Vancluse, the latter of which
became subject to the most violent torrential floods after the destruction of
the woods of its basin between 1823 and 1833, but has now been
completely subdued, and its waters brought to a peaceful flow, by
replanting its valley. See Labussiere, Revue Agric. et Forestiere de
Provence, 1866, and Revue des Eaux et Forets, 1866.]
Inundations in Winter.
In the Northern United States, although inundations are not very
unfrequently produced by heavy rains in the height of summer, it will be
found generally true that the most rapid rise of the waters, and, of course,
the most destructive "freshets," as they are called in America, are
occasioned by the sudden dissolution of the snow before the open ground is
thawed in the spring. It frequently happens that a powerful thaw sets in after
a long period of frost, and the snow which had been months in
accumulating is dissolved and carried off in a few hours. When the snow is
Page 312
deep, it, to use a popular expression, "takes the frost out of the ground" in
the woods, and, if it lies long enough, in the fields also. But the heaviest
snows usually fall after midwinter, and are succeeded by warm rains or
sunshine, which dissolve the snow on the cleared land before it has had
time to act upon the frost-bound soil beneath it. In this case, the snow in the
woods is absorbed as fast as it melts, by the soil it has protected from
freezing, and does not materially contribute to swell the current of the
rivers. If the mild weather, in which great snow-storms usually occur, does
not continue and become a regular thaw, it is almost sure to be followed by
drifting winds, and the inequality with which they distribute the snow over
the cleared ground leaves the ridges of the surface-soil comparatively bare,
while the depressions are often filled with drifts to the height of many feet.
The knolls become frozen to a great depth; succeeding partial thaws melt
the surface-snow, and the water runs down into the furrows of ploughed
fields, and other artificial and natural hollows, and then often freezes to
solid ice. In this state of things, almost the entire surface of the cleared land
is impervious to water, and from the absence of trees and the general
smoothness of the ground, it offers little mechanical resistance to superficial
currents. If, under these circumstances, warm weather accompanied by rain
occurs, the rain and melted snow are swiftly hurried to the bottom of the
valleys and gathered to raging torrents. It ought further to be considered
that, though the lighter ploughed soils readily imbibe a great deal of water,
yet grass-lands, and all the heavy and tenacious earths, absorb it in much
smaller quantities, and less rapidly than the vegetable mould of the forest.
Pasture, meadow, and clayey soils, taken together, greatly predominate over
sandy ploughed fields, in all large agricultural districts, and hence, even if,
in the case we are supposing, the open ground chance to have boon thawed
before the melting of the snow which covers it, it is already saturated with
moisture, or very soon becomes so, and, of course, cannot relieve the
pressure by absorbing more water. The consequence is that the face of the
the woods, and, if it lies long enough, in the fields also. But the heaviest
snows usually fall after midwinter, and are succeeded by warm rains or
sunshine, which dissolve the snow on the cleared land before it has had
time to act upon the frost-bound soil beneath it. In this case, the snow in the
woods is absorbed as fast as it melts, by the soil it has protected from
freezing, and does not materially contribute to swell the current of the
rivers. If the mild weather, in which great snow-storms usually occur, does
not continue and become a regular thaw, it is almost sure to be followed by
drifting winds, and the inequality with which they distribute the snow over
the cleared ground leaves the ridges of the surface-soil comparatively bare,
while the depressions are often filled with drifts to the height of many feet.
The knolls become frozen to a great depth; succeeding partial thaws melt
the surface-snow, and the water runs down into the furrows of ploughed
fields, and other artificial and natural hollows, and then often freezes to
solid ice. In this state of things, almost the entire surface of the cleared land
is impervious to water, and from the absence of trees and the general
smoothness of the ground, it offers little mechanical resistance to superficial
currents. If, under these circumstances, warm weather accompanied by rain
occurs, the rain and melted snow are swiftly hurried to the bottom of the
valleys and gathered to raging torrents. It ought further to be considered
that, though the lighter ploughed soils readily imbibe a great deal of water,
yet grass-lands, and all the heavy and tenacious earths, absorb it in much
smaller quantities, and less rapidly than the vegetable mould of the forest.
Pasture, meadow, and clayey soils, taken together, greatly predominate over
sandy ploughed fields, in all large agricultural districts, and hence, even if,
in the case we are supposing, the open ground chance to have boon thawed
before the melting of the snow which covers it, it is already saturated with
moisture, or very soon becomes so, and, of course, cannot relieve the
pressure by absorbing more water. The consequence is that the face of the
Page 313
country is suddenly flooded with a quantity of melted snow and rain
equivalent to a fall of six or eight inches of the latter, or even more. This
runs unobstructed to rivers often still-bound with thick ice, and thus
inundations of a fearfully devastating character are produced. The ice
bursts, from the hydrostatic pressure from below, or is violently torn up by
the current, and is swept by the impetuous stream, in large masses and with
resistless fury, against banks, bridges, dams, and mills erected near them.
The bark of the trees along the rivers is often abraded, at a height of many
feet above the ordinary water-level, by cakes of floating ice, which are at
last stranded by the receding flood on meadow or ploughland, to delay, by
their chilling influence, the advent of the tardy spring.
Another important effect of the removal of the forest shelter in cold
climates may be noticed here. We have observed that the ground in the
woods either does not freeze at all, or that if frozen it is thawed by the first
considerable snow-fall. On the contrary, the open ground is usually frozen
when the first spring freshet occurs, but is soon thawed by the warm rain
and melting snow. Nothing more effectually disintegrates a cohesive soil
than freezing and thawing, and the surface of earth which has just
undergone those processes is more subject to erosion by running water than
under any other circumstances. Hence more vegetable mould is washed
away from cultivated grounds in such climates by the spring floods than by
the heaviest rain at other seasons.
In the warm climates of Southern Europe, as I have already said, the
functions of the forest, so far as the disposal of the water of precipitation is
concerned, are essentially the same at all seasons, and are analogous to
those which it performs in the Northern United States in summer. Hence, in
the former countries, the winter floods have not the characteristics which
mark them in the latter, nor is the conservative influence of the woods in
winter relatively so important, though it is equally unquestionable.
equivalent to a fall of six or eight inches of the latter, or even more. This
runs unobstructed to rivers often still-bound with thick ice, and thus
inundations of a fearfully devastating character are produced. The ice
bursts, from the hydrostatic pressure from below, or is violently torn up by
the current, and is swept by the impetuous stream, in large masses and with
resistless fury, against banks, bridges, dams, and mills erected near them.
The bark of the trees along the rivers is often abraded, at a height of many
feet above the ordinary water-level, by cakes of floating ice, which are at
last stranded by the receding flood on meadow or ploughland, to delay, by
their chilling influence, the advent of the tardy spring.
Another important effect of the removal of the forest shelter in cold
climates may be noticed here. We have observed that the ground in the
woods either does not freeze at all, or that if frozen it is thawed by the first
considerable snow-fall. On the contrary, the open ground is usually frozen
when the first spring freshet occurs, but is soon thawed by the warm rain
and melting snow. Nothing more effectually disintegrates a cohesive soil
than freezing and thawing, and the surface of earth which has just
undergone those processes is more subject to erosion by running water than
under any other circumstances. Hence more vegetable mould is washed
away from cultivated grounds in such climates by the spring floods than by
the heaviest rain at other seasons.
In the warm climates of Southern Europe, as I have already said, the
functions of the forest, so far as the disposal of the water of precipitation is
concerned, are essentially the same at all seasons, and are analogous to
those which it performs in the Northern United States in summer. Hence, in
the former countries, the winter floods have not the characteristics which
mark them in the latter, nor is the conservative influence of the woods in
winter relatively so important, though it is equally unquestionable.
Page 314
If the summer floods in the United States are attended with less
pecuniary damage than those of the Loire and other rivers of France, the Po
and its tributaries in Italy, the Emme and her sister torrents which devastate
the valleys of Switzerland, it is partly because the banks of American rivers
are not yet lined with towns, their shores and the bottoms which skirt them
not yet covered with improvements whose cost is counted by millions, and,
consequently, a smaller amount of property is exposed to injury by
inundation. But the comparative exemption of the American people from
the terrible calamities which the overflow of rivers has brought on some of
the fairest portions of the Old World, is, in a still greater degree, to be
ascribed to the fact that, with all our thoughtless improvidence, we have not
yet bared all the sources of our streams, not yet overthrown all the barriers
which nature has erected to restrain her own destructive energies. Let us be
wise in time, and profit by the errors of our older brethren!
The influence of the forest in preventing inundations has been very
generally recognized, both as a theoretical inference and as a fact of
observation; but the eminent engineer Belgrand and his commentator Valles
have deduced an opposite result from various facts of experience and from
scientific considerations. They contend that the superficial drainage is more
regular from cleared than from wooded ground, and that clearing
diminishes rather than augments the intensity of inundations. Neither of
these conclusions appears to be warranted by their data or their reasoning,
and they rest partly upon facts, which, truly interpreted, are not inconsistent
with the received opinions on these subjects, partly upon assumptions
which are contradicted by experience. Two of these latter are, first, that the
fallen leaves in the forest constitute an impermeable covering of the soil
over, not through, which the water of rains and of melting snows flows off,
and secondly, that the roots of trees penetrate and choke up the fissures in
the rocks, so as to impede the passage of water through channels which
nature has provided for its descent to lower strata.
pecuniary damage than those of the Loire and other rivers of France, the Po
and its tributaries in Italy, the Emme and her sister torrents which devastate
the valleys of Switzerland, it is partly because the banks of American rivers
are not yet lined with towns, their shores and the bottoms which skirt them
not yet covered with improvements whose cost is counted by millions, and,
consequently, a smaller amount of property is exposed to injury by
inundation. But the comparative exemption of the American people from
the terrible calamities which the overflow of rivers has brought on some of
the fairest portions of the Old World, is, in a still greater degree, to be
ascribed to the fact that, with all our thoughtless improvidence, we have not
yet bared all the sources of our streams, not yet overthrown all the barriers
which nature has erected to restrain her own destructive energies. Let us be
wise in time, and profit by the errors of our older brethren!
The influence of the forest in preventing inundations has been very
generally recognized, both as a theoretical inference and as a fact of
observation; but the eminent engineer Belgrand and his commentator Valles
have deduced an opposite result from various facts of experience and from
scientific considerations. They contend that the superficial drainage is more
regular from cleared than from wooded ground, and that clearing
diminishes rather than augments the intensity of inundations. Neither of
these conclusions appears to be warranted by their data or their reasoning,
and they rest partly upon facts, which, truly interpreted, are not inconsistent
with the received opinions on these subjects, partly upon assumptions
which are contradicted by experience. Two of these latter are, first, that the
fallen leaves in the forest constitute an impermeable covering of the soil
over, not through, which the water of rains and of melting snows flows off,
and secondly, that the roots of trees penetrate and choke up the fissures in
the rocks, so as to impede the passage of water through channels which
nature has provided for its descent to lower strata.
Page 315
As to the first of those, we may appeal to familiar facts within the
personal knowledge of every man acquainted with the operations of sylvan
nature. Rain-water never, except in very trifling quantities, flows over the
leaves in the woods in summer or autumn. Water runs over them only in the
spring, in the rare cases when they have been pressed down smoothly and
compactly by the weight of the snow—a state in which they remain only
until they are dry, when shrinkage and the action of the wind soon roughen
the surface so as effectually to stop, by absorption, all flow of water. I have
observed that when a sudden frost succeeds a thaw at the close of the
winter, after the snow has principally disappeared, the water in and between
the layers of leaves sometimes freezes into a solid crust, which allows the
flow of water over it. But this occurs only in depressions and on a very
small scale; and the ice thus formed is so soon dissolved that no sensible
effect is produced on the escape of water from the general surface.
As to the influence of roots upon drainage, we have seen that there is no
doubt that they, independently of their action as absorbents, mechanically
promote it. Not only does the water of the soil follow them downwards, but
their swelling growth powerfully tends to enlarge, not to obstruct, the
crevices of rock into which they enter; and as the fissures in rocks are
longitudinal, not mere circular orifices, every line of additional width
gained by the growth of roots within them increases the area of the crevice
in proportion to its length. Consequently, the widening of a fissure to the
extent of one inch might give an additional drainage equal to a square foot
of open tubing.
The observations and reasonings of Belgrand and Valles, though their
conclusions have not been accepted by many, are very important in one
point of view. There writers insist much on the necessity of taking into
account, in estimating the relations between precipitation and evaporation,
the abstraction of water from the surface and surface-currents, by
personal knowledge of every man acquainted with the operations of sylvan
nature. Rain-water never, except in very trifling quantities, flows over the
leaves in the woods in summer or autumn. Water runs over them only in the
spring, in the rare cases when they have been pressed down smoothly and
compactly by the weight of the snow—a state in which they remain only
until they are dry, when shrinkage and the action of the wind soon roughen
the surface so as effectually to stop, by absorption, all flow of water. I have
observed that when a sudden frost succeeds a thaw at the close of the
winter, after the snow has principally disappeared, the water in and between
the layers of leaves sometimes freezes into a solid crust, which allows the
flow of water over it. But this occurs only in depressions and on a very
small scale; and the ice thus formed is so soon dissolved that no sensible
effect is produced on the escape of water from the general surface.
As to the influence of roots upon drainage, we have seen that there is no
doubt that they, independently of their action as absorbents, mechanically
promote it. Not only does the water of the soil follow them downwards, but
their swelling growth powerfully tends to enlarge, not to obstruct, the
crevices of rock into which they enter; and as the fissures in rocks are
longitudinal, not mere circular orifices, every line of additional width
gained by the growth of roots within them increases the area of the crevice
in proportion to its length. Consequently, the widening of a fissure to the
extent of one inch might give an additional drainage equal to a square foot
of open tubing.
The observations and reasonings of Belgrand and Valles, though their
conclusions have not been accepted by many, are very important in one
point of view. There writers insist much on the necessity of taking into
account, in estimating the relations between precipitation and evaporation,
the abstraction of water from the surface and surface-currents, by
Page 316
absorption and infiltration—an element unquestionably of great value, but
hitherto much neglected by meteorological inquirers, who have very often
reasoned as if the surface-earth were either impermeable to water or already
saturated with it; whereas, in fact, it is a sponge, always imbibing humidity
and always giving it off, not by evaporation only, but by infiltration and
percolation.
The remarkable historical notices of inundations in France in the Middle
Ages collected by Champion [Footnote: Les Inondations en France depuis
le VIe siecle jusqu'a nos jours, 6 vols, 8vo. Paris, 1858-64. See a very able
review of this learned and important work by Prof. Messedaglia, read
before the Academy of Agriculture at Verona in 1864.] are considered by
many as furnishing proof, that when that country was much more generally
covered with wood than it now is, destructive inundations of the French
rivers were not less frequent than they are in modern days. But this
evidence is subject to this among other objections: we know, it is true, that
the forests of certain departments of France were anciently much more
extensive than at the present day; but we know also that in many portions of
that country the soil has been bared of its forests, and then, in consequence
of the depopulation of great provinces, left to reclothe itself spontaneously
with trees, many times during the historic period; and our acquaintance with
the forest topography of ancient Gaul or of mediaeval France is neither
sufficiently extensive nor sufficiently minute to permit us to say, with
certainty, that the sources of this or that particular river were more or less
sheltered by wood at any given time, ancient or mediaeval, than at present.
[Footnote: Alfred Maury has, nevertheless, collected, in his erudite and able
work, Les Forets de la Gaule et de l'ancienne France, Paris, 1867, an
immense amount of statistical detail on the extent, the distribution, and the
destruction of the forests of France, but it still remains true that we can very
seldom pronounce on the forestal condition of the upper valley of a
particular river at the time of a given inundation in the ancient or the
hitherto much neglected by meteorological inquirers, who have very often
reasoned as if the surface-earth were either impermeable to water or already
saturated with it; whereas, in fact, it is a sponge, always imbibing humidity
and always giving it off, not by evaporation only, but by infiltration and
percolation.
The remarkable historical notices of inundations in France in the Middle
Ages collected by Champion [Footnote: Les Inondations en France depuis
le VIe siecle jusqu'a nos jours, 6 vols, 8vo. Paris, 1858-64. See a very able
review of this learned and important work by Prof. Messedaglia, read
before the Academy of Agriculture at Verona in 1864.] are considered by
many as furnishing proof, that when that country was much more generally
covered with wood than it now is, destructive inundations of the French
rivers were not less frequent than they are in modern days. But this
evidence is subject to this among other objections: we know, it is true, that
the forests of certain departments of France were anciently much more
extensive than at the present day; but we know also that in many portions of
that country the soil has been bared of its forests, and then, in consequence
of the depopulation of great provinces, left to reclothe itself spontaneously
with trees, many times during the historic period; and our acquaintance with
the forest topography of ancient Gaul or of mediaeval France is neither
sufficiently extensive nor sufficiently minute to permit us to say, with
certainty, that the sources of this or that particular river were more or less
sheltered by wood at any given time, ancient or mediaeval, than at present.
[Footnote: Alfred Maury has, nevertheless, collected, in his erudite and able
work, Les Forets de la Gaule et de l'ancienne France, Paris, 1867, an
immense amount of statistical detail on the extent, the distribution, and the
destruction of the forests of France, but it still remains true that we can very
seldom pronounce on the forestal condition of the upper valley of a
particular river at the time of a given inundation in the ancient or the
Page 317
mediaeval period.] I say the sources of the rivers, because the floods of
great rivers are occasioned by heavy rains and snows which fall in the more
elevated regions around the primal springs, and not by precipitation in the
main valleys or on the plains bordering on the lower course.
The destructive effects of inundations, considered simply as a mechanical
power by which life is endangered, crops destroyed, and the artificial
constructions of man overthrown, are very terrible. Thus far, however, the
flood is a temporary and by no means an irreparable evil, for if its ravages
end here, the prolific powers of nature and the industry of man soon restore
what had been lost, and the face of the earth no longer shows traces of the
deluge that had overwhelmed it. Inundations have even their
compensations. The structures they destroy are replaced by better and more
secure erections, and if they sweep off a crop of corn, they not unfrequently
leave behind them, as they subside, a fertilizing deposit which enriches the
exhausted field for a succession of seasons. [Footnote: The productiveness
of Egypt has been attributed too exclusively to the fertilizing effects of the
slime deposited by the inundations of the Nile; for in that climate a liberal
supply of water would produce good crops on almost any ordinary sand,
while, without water, the richest soil would yield nothing. The sediment
deposited annually is but a very small fraction of an inch in thickness. It is
alleged that in quantity it would be hardly sufficient for a good top-
dressing, and that in quality it is not chemically distinguishable from the
soil inches or feet below the surface. But to deny, as some writers have
done, that the slime has any fertilizing properties at all, is as great a error as
the opposite one of ascribing all the agricultural wealth of Egypt to that
single cause of productiveness. Fine soils deposited by water are almost
uniformly rich in all climates; those brought down by rivers, carried out into
salt-water, and then returned again by the tide, seem to be more
permanently fertile than any others. The polders of the Netherland coast are
of this character, and the meadows in Lincolnshire, which have been
great rivers are occasioned by heavy rains and snows which fall in the more
elevated regions around the primal springs, and not by precipitation in the
main valleys or on the plains bordering on the lower course.
The destructive effects of inundations, considered simply as a mechanical
power by which life is endangered, crops destroyed, and the artificial
constructions of man overthrown, are very terrible. Thus far, however, the
flood is a temporary and by no means an irreparable evil, for if its ravages
end here, the prolific powers of nature and the industry of man soon restore
what had been lost, and the face of the earth no longer shows traces of the
deluge that had overwhelmed it. Inundations have even their
compensations. The structures they destroy are replaced by better and more
secure erections, and if they sweep off a crop of corn, they not unfrequently
leave behind them, as they subside, a fertilizing deposit which enriches the
exhausted field for a succession of seasons. [Footnote: The productiveness
of Egypt has been attributed too exclusively to the fertilizing effects of the
slime deposited by the inundations of the Nile; for in that climate a liberal
supply of water would produce good crops on almost any ordinary sand,
while, without water, the richest soil would yield nothing. The sediment
deposited annually is but a very small fraction of an inch in thickness. It is
alleged that in quantity it would be hardly sufficient for a good top-
dressing, and that in quality it is not chemically distinguishable from the
soil inches or feet below the surface. But to deny, as some writers have
done, that the slime has any fertilizing properties at all, is as great a error as
the opposite one of ascribing all the agricultural wealth of Egypt to that
single cause of productiveness. Fine soils deposited by water are almost
uniformly rich in all climates; those brought down by rivers, carried out into
salt-water, and then returned again by the tide, seem to be more
permanently fertile than any others. The polders of the Netherland coast are
of this character, and the meadows in Lincolnshire, which have been
Page 318
covered with slime by warping, as it is called, or admitting water over them
at high tide, are remarkably productive.
Recent analysis is said to have detected in the water of the Nile a quantity
of organic matter—derived mainly, no doubt, from the decayed vegetation it
bears down from its tropical course—sufficiently large to furnish an
important supply of fertilizing ingredients to the soil.
It is computed that the Durance—a river fed chiefly by torrents, of great
erosive power—carries down annually solid material enough to cover
272,000 acres of soil with a deposit of two-fifths of an inch in thickness,
and that this deposit contains, in the combination most favorable to
vegetation, more azote than 110,000 tons of guano, and more carbon than
121,000 acres of woodland would assimilate in a year. Elisee Reclus, La
Terre, vol. i., p. 467. On the chemical composition, quantity, and value of
the solid matter transported by river, see Herve Magnon, Sur l'Emploi des
Eaux dans les Irrigations, 8vo. Paris, 1869, pp. 132 et seqq. Duponchel,
Traite d'Hydraulique et de Geologie Agricoles. Paris, 1868, chap. i., xii.,
and xiii.]
If, then, the too rapid flow of the surface-waters occasioned no other evil
than to produce, once in ten years upon the average, an inundation which
should destroy the harvest of the low grounds along the rivers, the damage
would be too inconsiderable, and of too transitory a character, to warrant
the inconveniences and the expense involved in the measures which the
most competent judges in many parts of Europe believe the respective
governments ought to take to obviate it.
Destructive Action of Torrents.
at high tide, are remarkably productive.
Recent analysis is said to have detected in the water of the Nile a quantity
of organic matter—derived mainly, no doubt, from the decayed vegetation it
bears down from its tropical course—sufficiently large to furnish an
important supply of fertilizing ingredients to the soil.
It is computed that the Durance—a river fed chiefly by torrents, of great
erosive power—carries down annually solid material enough to cover
272,000 acres of soil with a deposit of two-fifths of an inch in thickness,
and that this deposit contains, in the combination most favorable to
vegetation, more azote than 110,000 tons of guano, and more carbon than
121,000 acres of woodland would assimilate in a year. Elisee Reclus, La
Terre, vol. i., p. 467. On the chemical composition, quantity, and value of
the solid matter transported by river, see Herve Magnon, Sur l'Emploi des
Eaux dans les Irrigations, 8vo. Paris, 1869, pp. 132 et seqq. Duponchel,
Traite d'Hydraulique et de Geologie Agricoles. Paris, 1868, chap. i., xii.,
and xiii.]
If, then, the too rapid flow of the surface-waters occasioned no other evil
than to produce, once in ten years upon the average, an inundation which
should destroy the harvest of the low grounds along the rivers, the damage
would be too inconsiderable, and of too transitory a character, to warrant
the inconveniences and the expense involved in the measures which the
most competent judges in many parts of Europe believe the respective
governments ought to take to obviate it.
Destructive Action of Torrents.
Page 319
But the great, the irreparable, the appalling mischiefs which have already
resulted, and which threaten to ensue on a still more extensive scale
hereafter, from too rapid superficial drainage, are of a properly
geographical, we may almost say geological, character, and consist
primarily in erosion, displacement, and transportation of the superficial
strata, vegetable and mineral—of the integuments, so to speak, with which
nature has clothed the skeleton frame-work of the globe. It is difficult to
convey by description an idea of the desolation of the regions most exposed
to the ravages of torrent and of flood; and the thousands who, in these days
of swift travel, are whirled by steam near or even through the theatres of
these calamities, have but rare and imperfect opportunities of observing the
destructive causes in action. Still more rarely can they compare the past
with the actual condition of the provinces in question, and trace the progress
of their conversion from forest-crowned hills, luxuriant pasture grounds,
and abundant cornfields and vineyards well watered by springs and
fertilizing rivulets, to bald mountain ridges, rocky declivities, and steep
earth-banks furrowed by deep ravines with beds now dry, now filled by
torrents of fluid mud and gravel hurrying down to spread themselves over
the plain, and dooming to everlasting barrenness the once productive fields.
In surveying such scenes, it is difficult to resist the impression that nature
pronounced a primal curse of perpetual sterility and desolation upon these
sublime but fearful wastes, difficult to believe that they wore once, and but
for the folly of man might still be, blessed with all the natural advantages
which Providence has bestowed upon the most favored climes. But the
historical evidence is conclusive as to the destructive changes occasioned
by the agency of man upon the flanks of the Alps, the Apennines, the
Pyrenees, and other mountain ranges in Central and Southern Europe, and
the progress of physical deterioration has been so rapid that, in some
localities, a single generation has witnessed the beginning and the end of
the melancholy revolution.
resulted, and which threaten to ensue on a still more extensive scale
hereafter, from too rapid superficial drainage, are of a properly
geographical, we may almost say geological, character, and consist
primarily in erosion, displacement, and transportation of the superficial
strata, vegetable and mineral—of the integuments, so to speak, with which
nature has clothed the skeleton frame-work of the globe. It is difficult to
convey by description an idea of the desolation of the regions most exposed
to the ravages of torrent and of flood; and the thousands who, in these days
of swift travel, are whirled by steam near or even through the theatres of
these calamities, have but rare and imperfect opportunities of observing the
destructive causes in action. Still more rarely can they compare the past
with the actual condition of the provinces in question, and trace the progress
of their conversion from forest-crowned hills, luxuriant pasture grounds,
and abundant cornfields and vineyards well watered by springs and
fertilizing rivulets, to bald mountain ridges, rocky declivities, and steep
earth-banks furrowed by deep ravines with beds now dry, now filled by
torrents of fluid mud and gravel hurrying down to spread themselves over
the plain, and dooming to everlasting barrenness the once productive fields.
In surveying such scenes, it is difficult to resist the impression that nature
pronounced a primal curse of perpetual sterility and desolation upon these
sublime but fearful wastes, difficult to believe that they wore once, and but
for the folly of man might still be, blessed with all the natural advantages
which Providence has bestowed upon the most favored climes. But the
historical evidence is conclusive as to the destructive changes occasioned
by the agency of man upon the flanks of the Alps, the Apennines, the
Pyrenees, and other mountain ranges in Central and Southern Europe, and
the progress of physical deterioration has been so rapid that, in some
localities, a single generation has witnessed the beginning and the end of
the melancholy revolution.
Page 320
I have stated, in a general way, the nature of the evils in question, and of
the processes by which they are produced; but I shall make their precise
character and magnitude better understood by presenting some descriptive
and statistical details of facts of actual occurrence. I select for this purpose
the south-eastern portion of France, not because that territory has suffered
more severely than some others, but because its deterioration is
comparatively recent, and has been watched and described by very
competent and trustworthy observers, whose reports are more easily
accessible than those published in other countries. [Footnote: Streffleur
(Ueber die Natur und die Wirkungen der Wildbuche, p. 3) maintains that all
the observations and speculations of French authors on the nature of
torrents had been anticipated by Austrian writers. In proof of this assertion
he refers to the works of Franz von Zallinger, 1778, Von Arretin, 1808,
Franz Duile, 1826, all published at Innsbruck, and Hagenus Beschreibung
neuerer Wasserbauwerke, Konigsberg, 1826, none of which works are
known to me. It is evident, however, that the conclusions of Surell and other
French writers whom I cite, are original results of personal investigation,
and not borrowed opinions.]
The provinces of Dauphiny and Provence comprise a territory of fourteen
or fifteen thousand square miles, bounded north-west by the Isere, north-
east and east by the Alps, south by the Mediterranean, west by the Rhone,
and extending from 42 degrees to about 45 degrees of north latitude. The
surface is generally hilly and even mountainous, and several of the peaks in
Dauphiny rise above the limit of perpetual snow. Except upon the mountain
ridges, the climate, as compared with that of the United States in the same
latitude, is extremely mild. Little snow falls, except upon the higher
mountains, the frosts are light, and the summers long, as might, indeed, be
inferred from the vegetation; for in the cultivated districts, the vine and the
fig everywhere flourish; the olive thrives as far north as 43 and one half
degrees, and upon the coast grow the orange, the lemon, and the date-palm.
the processes by which they are produced; but I shall make their precise
character and magnitude better understood by presenting some descriptive
and statistical details of facts of actual occurrence. I select for this purpose
the south-eastern portion of France, not because that territory has suffered
more severely than some others, but because its deterioration is
comparatively recent, and has been watched and described by very
competent and trustworthy observers, whose reports are more easily
accessible than those published in other countries. [Footnote: Streffleur
(Ueber die Natur und die Wirkungen der Wildbuche, p. 3) maintains that all
the observations and speculations of French authors on the nature of
torrents had been anticipated by Austrian writers. In proof of this assertion
he refers to the works of Franz von Zallinger, 1778, Von Arretin, 1808,
Franz Duile, 1826, all published at Innsbruck, and Hagenus Beschreibung
neuerer Wasserbauwerke, Konigsberg, 1826, none of which works are
known to me. It is evident, however, that the conclusions of Surell and other
French writers whom I cite, are original results of personal investigation,
and not borrowed opinions.]
The provinces of Dauphiny and Provence comprise a territory of fourteen
or fifteen thousand square miles, bounded north-west by the Isere, north-
east and east by the Alps, south by the Mediterranean, west by the Rhone,
and extending from 42 degrees to about 45 degrees of north latitude. The
surface is generally hilly and even mountainous, and several of the peaks in
Dauphiny rise above the limit of perpetual snow. Except upon the mountain
ridges, the climate, as compared with that of the United States in the same
latitude, is extremely mild. Little snow falls, except upon the higher
mountains, the frosts are light, and the summers long, as might, indeed, be
inferred from the vegetation; for in the cultivated districts, the vine and the
fig everywhere flourish; the olive thrives as far north as 43 and one half
degrees, and upon the coast grow the orange, the lemon, and the date-palm.
Page 321
The forest trees, too, are of southern type, umbrella pines, various species
of evergreen oaks, and many other trees and shrubs of persistent broad-
leaved foliage, characterizing the landscape.
The rapid slope of the mountains naturally exposed these provinces to
damage by torrents, and the Romans diminished their injurious effects by
erecting, in the beds of ravines, barriers of rocks loosely piled up, which
permitted a slow escape of the water, but compelled it to deposit above the
dikes the earth and gravel with which it was charged. [Footnote: Whether
Palissy was acquainted with this ancient practice, or whether it was one of
those original suggestions of which his works are so full, I know not, but in
his treatise, Des Eaux et Fontaines, he thus recommends it, by way of reply
to the objections of "Theorique," who had expressed the fear that "the
waters which rush violently down from the heights of the mountain would
bring with them much earth, sand, and other things," and thus spoil the
artificial fountain that "Practique" was teaching him to make: "And for
hindrance of the mischiefs of great waters which may be gathered in a few
hours by great storms, when thou shalt have made ready thy parterre to
receive the water, thou must lay great atones athwart the deep channels
which lead to thy parterre. And so the force of the rushing currents shall be
deadened, and thy water shall flow peacefully into his cisterns."—Oeuvres
Completes, p. 178.] At a later period the Crusaders brought home from
Palestine, with much other knowledge gathered from the wiser Moslems,
the art of securing the hillsides and making them productive by terracing
and irrigation. The forests which covered the mountains secured an
abundant flow of springs, and the process of clearing the soil went on so
slowly that, for centuries, neither the want of timber and fuel, nor the other
evils about to be depicted, were seriously felt. Indeed, throughout the
Middle Ages, these provinces were well wooded, and famous for the
fertility and abundance, not only of the low grounds, but of the hills.
of evergreen oaks, and many other trees and shrubs of persistent broad-
leaved foliage, characterizing the landscape.
The rapid slope of the mountains naturally exposed these provinces to
damage by torrents, and the Romans diminished their injurious effects by
erecting, in the beds of ravines, barriers of rocks loosely piled up, which
permitted a slow escape of the water, but compelled it to deposit above the
dikes the earth and gravel with which it was charged. [Footnote: Whether
Palissy was acquainted with this ancient practice, or whether it was one of
those original suggestions of which his works are so full, I know not, but in
his treatise, Des Eaux et Fontaines, he thus recommends it, by way of reply
to the objections of "Theorique," who had expressed the fear that "the
waters which rush violently down from the heights of the mountain would
bring with them much earth, sand, and other things," and thus spoil the
artificial fountain that "Practique" was teaching him to make: "And for
hindrance of the mischiefs of great waters which may be gathered in a few
hours by great storms, when thou shalt have made ready thy parterre to
receive the water, thou must lay great atones athwart the deep channels
which lead to thy parterre. And so the force of the rushing currents shall be
deadened, and thy water shall flow peacefully into his cisterns."—Oeuvres
Completes, p. 178.] At a later period the Crusaders brought home from
Palestine, with much other knowledge gathered from the wiser Moslems,
the art of securing the hillsides and making them productive by terracing
and irrigation. The forests which covered the mountains secured an
abundant flow of springs, and the process of clearing the soil went on so
slowly that, for centuries, neither the want of timber and fuel, nor the other
evils about to be depicted, were seriously felt. Indeed, throughout the
Middle Ages, these provinces were well wooded, and famous for the
fertility and abundance, not only of the low grounds, but of the hills.
Page 322
Such was the state of things at the close of the fifteenth century. The
statistics of the seventeenth show that while there had been an increase of
prosperity and population in Lower Provence, as well as in the
correspondingly situated parts of the other two provinces I have mentioned,
there was an alarming decrease both in the wealth and in the population of
Upper Provence and Dauphiny, although, by the clearing of the forests, a
great extent of plough-land and pasturage had been added to the soil before
reduced to cultivation. It was found, in fact, that the augmented violence of
the torrents had swept away, or buried in sand and gravel, more land than
had been reclaimed by clearing; and the taxes computed by fires or
habitations underwent several successive reductions in consequence of the
gradual abandonment of the wasted soil by its starving occupants. The
growth of the large towns on and near the Rhone and the coast, their
advance in commerce and industry, and the consequently enlarged demand
for agricultural products, ought naturally to have increased the rural
population and the value of their lands; but the physical decay of the
uplands was such that considerable tracts were deserted altogether, and in
Upper Provence, the fires which, in 1471 counted 897, were reduced to 747
in 1699, to 728 in 1733, and to 635 in 1776. [Footnote: These facts I take
from the La Provence au point de vue des Bois, des Torrents et des
Inondations, of Charles de Ribbe, one of the highest authorities.]
Surell—whose admirable work, Etude sur les Torrents des Hautes Alpes,
first published in 1841, [Footnote: A second edition of this work, with an
additional volume of great value by Ernest Cezanne, was published at Paris,
in two 8vo volumes, in 1871-72.] presents a most appalling picture of the
desolations of the torrent, and, at the same time, the most careful studies of
the history and essential character of this great evil—in speaking of the
valley of Devoluy, on page 152, says: "Everything concurs to show that it
was anciently wooded. In its peat-bogs are found buried trunks of trees,
monuments of its former vegetation. In the framework of old houses, one
statistics of the seventeenth show that while there had been an increase of
prosperity and population in Lower Provence, as well as in the
correspondingly situated parts of the other two provinces I have mentioned,
there was an alarming decrease both in the wealth and in the population of
Upper Provence and Dauphiny, although, by the clearing of the forests, a
great extent of plough-land and pasturage had been added to the soil before
reduced to cultivation. It was found, in fact, that the augmented violence of
the torrents had swept away, or buried in sand and gravel, more land than
had been reclaimed by clearing; and the taxes computed by fires or
habitations underwent several successive reductions in consequence of the
gradual abandonment of the wasted soil by its starving occupants. The
growth of the large towns on and near the Rhone and the coast, their
advance in commerce and industry, and the consequently enlarged demand
for agricultural products, ought naturally to have increased the rural
population and the value of their lands; but the physical decay of the
uplands was such that considerable tracts were deserted altogether, and in
Upper Provence, the fires which, in 1471 counted 897, were reduced to 747
in 1699, to 728 in 1733, and to 635 in 1776. [Footnote: These facts I take
from the La Provence au point de vue des Bois, des Torrents et des
Inondations, of Charles de Ribbe, one of the highest authorities.]
Surell—whose admirable work, Etude sur les Torrents des Hautes Alpes,
first published in 1841, [Footnote: A second edition of this work, with an
additional volume of great value by Ernest Cezanne, was published at Paris,
in two 8vo volumes, in 1871-72.] presents a most appalling picture of the
desolations of the torrent, and, at the same time, the most careful studies of
the history and essential character of this great evil—in speaking of the
valley of Devoluy, on page 152, says: "Everything concurs to show that it
was anciently wooded. In its peat-bogs are found buried trunks of trees,
monuments of its former vegetation. In the framework of old houses, one
Page 323
sees enormous timber, which is no longer to be found in the district. Many
localities, now completely bare, still retain the name of 'wood,' and one of
them is called, in old deeds, Comba nigra [Black forest or dell], on account
of its dense woods. These and many other proofs confirm the local
traditions which are unanimous on this point.
"There, as everywhere in the Upper Alps, the clearings began on the
flanks of the mountains, and were gradually extended into the valleys and
then to the highest accessible peaks. Then followed the Revolution, and
caused the destruction of the remainder of the trees which had thus far
escaped the woodman's axe."
In a note to this passage the writer says: "Several persons have told me
that they had lost flocks of sheep, by straying, in the forests of Mont
Auroux, which covered the flanks of the mountain from La Cluse to
Agneres. These declivities are now as bare as the palm of the hand."
The ground upon the steep mountains being once bared of trees, and the
underwood killed by the grazing of horned cattle, sheep, and goats, every
depression becomes a water-course. "Every storm," says Surell, page 153,
"gives rise to a new torrent. [Footnote: No attentive observer can frequent
the southern flank of the Piedmontese Alps or the French province of
Dauphiny, for half a dozen years, without witnessing with his own eyes the
formation and increase of new torrents. I can bear personal testimony to the
conversion of more than one grassy slope into the bed of a furious torrent
by baring the hills above of their woods.] Examples of such are shown,
which, though not yet three years old, have laid waste the finest fields of
their valleys, and whole villages have narrowly escaped being swept into
ravines formed in the course of a few hours. Sometimes the flood pours in a
sheet over the surface, without ravine or even bed, and ruins extensive
grounds, which are abandoned forever."
localities, now completely bare, still retain the name of 'wood,' and one of
them is called, in old deeds, Comba nigra [Black forest or dell], on account
of its dense woods. These and many other proofs confirm the local
traditions which are unanimous on this point.
"There, as everywhere in the Upper Alps, the clearings began on the
flanks of the mountains, and were gradually extended into the valleys and
then to the highest accessible peaks. Then followed the Revolution, and
caused the destruction of the remainder of the trees which had thus far
escaped the woodman's axe."
In a note to this passage the writer says: "Several persons have told me
that they had lost flocks of sheep, by straying, in the forests of Mont
Auroux, which covered the flanks of the mountain from La Cluse to
Agneres. These declivities are now as bare as the palm of the hand."
The ground upon the steep mountains being once bared of trees, and the
underwood killed by the grazing of horned cattle, sheep, and goats, every
depression becomes a water-course. "Every storm," says Surell, page 153,
"gives rise to a new torrent. [Footnote: No attentive observer can frequent
the southern flank of the Piedmontese Alps or the French province of
Dauphiny, for half a dozen years, without witnessing with his own eyes the
formation and increase of new torrents. I can bear personal testimony to the
conversion of more than one grassy slope into the bed of a furious torrent
by baring the hills above of their woods.] Examples of such are shown,
which, though not yet three years old, have laid waste the finest fields of
their valleys, and whole villages have narrowly escaped being swept into
ravines formed in the course of a few hours. Sometimes the flood pours in a
sheet over the surface, without ravine or even bed, and ruins extensive
grounds, which are abandoned forever."
Page 324
I cannot follow Surell in his description and classification of torrents, and
I must refer the reader to his instructive work for a full exposition of the
theory of the subject. In order, however, to show what a concentration of
destructive energies may be effected by felling the woods that clothe and
support the sides of mountain abysses, I cite his description of a valley
descending from the Col Isoard, which he calls "a complete type of a basin
of reception," that is, a gorge which serves as a common point of
accumulation and discharge for the waters of several lateral torrents. "The
aspect of the monstrous channel," says he, "is frightful. Within a distance of
less than two English miles, more than sixty torrents hurl into the depths of
the gorge the debris torn from its two flanks. The smallest of these
secondary torrents, if transferred to a fertile valley, would be enough to ruin
it."
The eminent political economist Blanqui, in a memoir read before the
Academy of Moral and Political Science on the 25th of November, 1843,
thus expresses himself: "Important as are the causes of impoverishment
already described, they are not to be compared to the consequences which
have followed from the two inveterate evils of the Alpine provinces of
France, the extension of clearing and the ravages of torrents. … The most
important result of this destruction is this; that the agricultural capital, or
rather the ground itself—which, in a rapidly increasing degree, is daily
swept away by the waters—is totally lost. Signs of unparalleled destitution
are visible in all the mountain zone, and the solitudes of those districts are
assuming an indescribable character of sterility and desolation. The gradual
destruction of the woods has, in a thousand localities, annihilated at once
the springs and the fuel. Between Grenoble and Briancon, in the valley of
the Romanche, many villages are so destitute of wood that they are reduced
to the necessity of baking their bread with sun-dried cow-dung, and even
this they can afford to do but once a year.
I must refer the reader to his instructive work for a full exposition of the
theory of the subject. In order, however, to show what a concentration of
destructive energies may be effected by felling the woods that clothe and
support the sides of mountain abysses, I cite his description of a valley
descending from the Col Isoard, which he calls "a complete type of a basin
of reception," that is, a gorge which serves as a common point of
accumulation and discharge for the waters of several lateral torrents. "The
aspect of the monstrous channel," says he, "is frightful. Within a distance of
less than two English miles, more than sixty torrents hurl into the depths of
the gorge the debris torn from its two flanks. The smallest of these
secondary torrents, if transferred to a fertile valley, would be enough to ruin
it."
The eminent political economist Blanqui, in a memoir read before the
Academy of Moral and Political Science on the 25th of November, 1843,
thus expresses himself: "Important as are the causes of impoverishment
already described, they are not to be compared to the consequences which
have followed from the two inveterate evils of the Alpine provinces of
France, the extension of clearing and the ravages of torrents. … The most
important result of this destruction is this; that the agricultural capital, or
rather the ground itself—which, in a rapidly increasing degree, is daily
swept away by the waters—is totally lost. Signs of unparalleled destitution
are visible in all the mountain zone, and the solitudes of those districts are
assuming an indescribable character of sterility and desolation. The gradual
destruction of the woods has, in a thousand localities, annihilated at once
the springs and the fuel. Between Grenoble and Briancon, in the valley of
the Romanche, many villages are so destitute of wood that they are reduced
to the necessity of baking their bread with sun-dried cow-dung, and even
this they can afford to do but once a year.
Page 325
"Whoever has visited the valley of Barcelonette, those of Embrun, and of
Verdun, and that Arabia Petraea of the department of the Upper Alps, called
Devoluy, knows that there is no time to lose—that in fifty years from this
date France will be separated from Savoy, as Egypt from Syria, by a
desert." [Footnote: Ladoucette says the peasant of Devoluy "often goes a
distance of five hours over rocks and precipices for a single [man's] load of
wood;" and he remarks on another page, that "the justice of peace of that
canton had, in the course of forty-three years, but once heard the voice of
the nightingale."—Histoire, etc, des Hautes Alpes, pp. 220, 434.]
It deserves to be specially noticed that the district here referred to, though
now among the most hopelessly waste in France, was very productive even
down to so late a period as the commencement of the French Revolution.
Arthur Young, writing in 1789, says: "About Barcelonette and in the highest
parts of the mountains, the hill-pastures feed a million of sheep, besides
large herds of other cattle;" and he adds: "With such a soil and in such a
climate, we are not to suppose a country barren because it is mountainous.
The valleys I have visited are, in general, beautiful." [Footnote: The valley
of Embrun, now almost completely devastated, was once remarkable for its
fertility. In 1800, Hericart de Thury said of it: "In this magnificent valley
nature had been prodigal of her gifts. Its inhabitants have blindly revelled in
her favors, and fallen asleep in the midst of her profusion."—Becquerel,
Des Climats, etc., p. 314.] He ascribes the same character to the provinces
of Dauphiny, Provence, and Auvergne, and, though he visited, with the eye
of an attentive and practised observer, many of the scenes since blasted with
the wild desolation described by Blanqui, the Durance and a part of the
course of the Loire are the only streams he mentions as inflicting serious
injury by their floods. The ravages of the torrents had, indeed, as we have
seen, commenced earlier in some other localities, but we are authorized to
infer that they were, in Young's time, too limited in range, and relatively too
Verdun, and that Arabia Petraea of the department of the Upper Alps, called
Devoluy, knows that there is no time to lose—that in fifty years from this
date France will be separated from Savoy, as Egypt from Syria, by a
desert." [Footnote: Ladoucette says the peasant of Devoluy "often goes a
distance of five hours over rocks and precipices for a single [man's] load of
wood;" and he remarks on another page, that "the justice of peace of that
canton had, in the course of forty-three years, but once heard the voice of
the nightingale."—Histoire, etc, des Hautes Alpes, pp. 220, 434.]
It deserves to be specially noticed that the district here referred to, though
now among the most hopelessly waste in France, was very productive even
down to so late a period as the commencement of the French Revolution.
Arthur Young, writing in 1789, says: "About Barcelonette and in the highest
parts of the mountains, the hill-pastures feed a million of sheep, besides
large herds of other cattle;" and he adds: "With such a soil and in such a
climate, we are not to suppose a country barren because it is mountainous.
The valleys I have visited are, in general, beautiful." [Footnote: The valley
of Embrun, now almost completely devastated, was once remarkable for its
fertility. In 1800, Hericart de Thury said of it: "In this magnificent valley
nature had been prodigal of her gifts. Its inhabitants have blindly revelled in
her favors, and fallen asleep in the midst of her profusion."—Becquerel,
Des Climats, etc., p. 314.] He ascribes the same character to the provinces
of Dauphiny, Provence, and Auvergne, and, though he visited, with the eye
of an attentive and practised observer, many of the scenes since blasted with
the wild desolation described by Blanqui, the Durance and a part of the
course of the Loire are the only streams he mentions as inflicting serious
injury by their floods. The ravages of the torrents had, indeed, as we have
seen, commenced earlier in some other localities, but we are authorized to
infer that they were, in Young's time, too limited in range, and relatively too
Page 326
insignificant, to require notice in a general view of the provinces where they
have now ruined so large a proportion of the soil.
But I resume my citations.
"I do not exaggerate," says Blanqui. "When I shall have finished my
description and designated localities by their names, there will rise, I am
sure, more than one voice from the spots themselves, to attest the rigorous
exactness of this picture of their wretchedness. I have never seen its equal
even in the Kabyle villages of the province of Constantine; for there you
can travel on horseback, and you find grass in the spring, whereas in more
than fifty communes in the Alps there is absolutely nothing.
"The clear, brilliant, Alpine sky of Embrun, of Gap, of Barcelonette, and
of Digne, which for months is without a cloud, produces droughts
interrupted only by diluvial rains like those of the tropics. The abuse of the
right of pasturage and the felling of the woods have stripped the soil of all
its grass and all its trees, and the scorching sun bakes it to the consistence of
porphyry. When moistened by the rain, as it has neither support nor
cohesion, it rolls down to the valleys, sometimes in floods resembling
black, yellow, or reddish lava, sometimes in streams of pebbles, and over
huge blocks of stone, which pour down with a frightful roar, and in their
swift course exhibit the most convulsive movements. If you overlook from
an eminence one of these landscapes furrowed with so many ravines, it
presents only images of desolation and of death. Vast deposits of flinty
pebbles, many feet in thickness, which have rolled down and spread far
over the plain, surround large trees, bury even their tops, and rise above
them, leaving to the husbandman no longer a ray of hope. One can imagine
no sadder spectacle than the deep fissures in the flanks of the mountains,
which seem to have burst forth in eruption to cover the plains with their
ruins. Those gorges, under the influence of the sun which cracks and shivers
have now ruined so large a proportion of the soil.
But I resume my citations.
"I do not exaggerate," says Blanqui. "When I shall have finished my
description and designated localities by their names, there will rise, I am
sure, more than one voice from the spots themselves, to attest the rigorous
exactness of this picture of their wretchedness. I have never seen its equal
even in the Kabyle villages of the province of Constantine; for there you
can travel on horseback, and you find grass in the spring, whereas in more
than fifty communes in the Alps there is absolutely nothing.
"The clear, brilliant, Alpine sky of Embrun, of Gap, of Barcelonette, and
of Digne, which for months is without a cloud, produces droughts
interrupted only by diluvial rains like those of the tropics. The abuse of the
right of pasturage and the felling of the woods have stripped the soil of all
its grass and all its trees, and the scorching sun bakes it to the consistence of
porphyry. When moistened by the rain, as it has neither support nor
cohesion, it rolls down to the valleys, sometimes in floods resembling
black, yellow, or reddish lava, sometimes in streams of pebbles, and over
huge blocks of stone, which pour down with a frightful roar, and in their
swift course exhibit the most convulsive movements. If you overlook from
an eminence one of these landscapes furrowed with so many ravines, it
presents only images of desolation and of death. Vast deposits of flinty
pebbles, many feet in thickness, which have rolled down and spread far
over the plain, surround large trees, bury even their tops, and rise above
them, leaving to the husbandman no longer a ray of hope. One can imagine
no sadder spectacle than the deep fissures in the flanks of the mountains,
which seem to have burst forth in eruption to cover the plains with their
ruins. Those gorges, under the influence of the sun which cracks and shivers
Page 327
to fragments the very rocks, and of the rain which sweeps them down,
penetrate deeper and deeper into the heart of the mountain, while the beds
of the torrents issuing from them are sometimes raised several feet in a
single year, by the debris, so that they reach the level of the bridges, which,
of course, are then carried off. The torrent-beds are recognized at a great
distance, as they issue from the mountains, and they spread themselves over
the low grounds, in fan-shaped expansions, like a mantle of stone,
sometimes ten thousand feet wide, rising high at the centre, and curving
towards the circumference till their lower edges meet the plain.
"Such is their aspect in dry weather. But no tongue can give an adequate
description of their devastations in one of those sudden floods winch
resemble, in almost none of their phenomena, the action of ordinary river-
water. They are now no longer overflowing brooks, but real seas, tumbling
down in cataracts, and rolling before them blocks of stone, which are hurled
forwards by the shock of the waves like balls shot out by the explosion of
gunpowder. Sometimes ridges of pebbles are driven down when the
transporting torrent does not rise high enough to show itself, and then the
movement is accompanied with a roar louder than the crash of thunder. A
furious wind precedes the rushing water and announces its approach. Then
comes a violent eruption, followed by a flow of muddy waves, and after a
few hours all returns to the dreary silence which at periods of rest marks
these abodes of desolation. [Footnote: These explosive gushes of mud and
rock appear to be occasioned by the caving-in of large masses of earth from
the banks of the torrent, which dam up the stream and check its flow until it
has acquired volume enough to burst the barrier and carry all before it. In
1827, such a sudden eruption of a torrent, after the current had appeared to
have ceased, swept off forty-two houses and drowned twenty-eight persons
in the village of Goncelin, near Grenoble, and buried with rubbish a great
part of the remainder of the village."
penetrate deeper and deeper into the heart of the mountain, while the beds
of the torrents issuing from them are sometimes raised several feet in a
single year, by the debris, so that they reach the level of the bridges, which,
of course, are then carried off. The torrent-beds are recognized at a great
distance, as they issue from the mountains, and they spread themselves over
the low grounds, in fan-shaped expansions, like a mantle of stone,
sometimes ten thousand feet wide, rising high at the centre, and curving
towards the circumference till their lower edges meet the plain.
"Such is their aspect in dry weather. But no tongue can give an adequate
description of their devastations in one of those sudden floods winch
resemble, in almost none of their phenomena, the action of ordinary river-
water. They are now no longer overflowing brooks, but real seas, tumbling
down in cataracts, and rolling before them blocks of stone, which are hurled
forwards by the shock of the waves like balls shot out by the explosion of
gunpowder. Sometimes ridges of pebbles are driven down when the
transporting torrent does not rise high enough to show itself, and then the
movement is accompanied with a roar louder than the crash of thunder. A
furious wind precedes the rushing water and announces its approach. Then
comes a violent eruption, followed by a flow of muddy waves, and after a
few hours all returns to the dreary silence which at periods of rest marks
these abodes of desolation. [Footnote: These explosive gushes of mud and
rock appear to be occasioned by the caving-in of large masses of earth from
the banks of the torrent, which dam up the stream and check its flow until it
has acquired volume enough to burst the barrier and carry all before it. In
1827, such a sudden eruption of a torrent, after the current had appeared to
have ceased, swept off forty-two houses and drowned twenty-eight persons
in the village of Goncelin, near Grenoble, and buried with rubbish a great
part of the remainder of the village."
Page 328
The French traveller, D'Abbadie, relates precisely similar occurrences as
not unfrequent in the mountains of Abyssinia.—Surrell, Etudes, etc; 2d
edition, pp. 224, 295.]
"The elements of destruction are increasing in violence. The devastation
advances in geometrical progression as the higher slopes are bared of their
wood, and 'the ruin from above,' to use the words of a peasant, 'helps to
hasten the desolation below.'
"The Alps of Provence present a terrible aspect. In the more equable
climate of Northern France, one can form no conception of those parched
mountain gorges where not even a bush can be found to shelter a bird,
where, at most, the wanderer sees in summer here and there a withered
lavender, where all the springs are dried up, and where a dead silence,
hardly broken by even the hum of an insect, prevails. But if a storm bursts
forth, masses of water suddenly shoot from the mountain heights into the
shattered gulfs, waste without irrigating, deluge without refreshing the soil
they overflow in their swift descent, and leave it even more seared than it
was from want of moisture. Man at last retires from the fearful desert, and I
have, the present season, found not a living soul in districts where I
remember to have enjoyed hospitality thirty years ago."
In 1853, ten years after the date of Blanqui's memoir, M. de Bonville,
prefect of the Lower Alps, addressed to the Government a report in which
the following passages occur:
"It is certain that the productive mould of the Alps, swept off by the
increasing violence of that curse of the mountains, the torrents, is daily
diminishing with fearful rapidity. All our Alps are wholly, or in large
proportion, bared of wood. Their soil, scorched by the sun of Provence, cut
up by the hoofs of the sheep, which, not finding on the surface the grass
they require for their sustenance, gnaw and scratch the ground in search of
not unfrequent in the mountains of Abyssinia.—Surrell, Etudes, etc; 2d
edition, pp. 224, 295.]
"The elements of destruction are increasing in violence. The devastation
advances in geometrical progression as the higher slopes are bared of their
wood, and 'the ruin from above,' to use the words of a peasant, 'helps to
hasten the desolation below.'
"The Alps of Provence present a terrible aspect. In the more equable
climate of Northern France, one can form no conception of those parched
mountain gorges where not even a bush can be found to shelter a bird,
where, at most, the wanderer sees in summer here and there a withered
lavender, where all the springs are dried up, and where a dead silence,
hardly broken by even the hum of an insect, prevails. But if a storm bursts
forth, masses of water suddenly shoot from the mountain heights into the
shattered gulfs, waste without irrigating, deluge without refreshing the soil
they overflow in their swift descent, and leave it even more seared than it
was from want of moisture. Man at last retires from the fearful desert, and I
have, the present season, found not a living soul in districts where I
remember to have enjoyed hospitality thirty years ago."
In 1853, ten years after the date of Blanqui's memoir, M. de Bonville,
prefect of the Lower Alps, addressed to the Government a report in which
the following passages occur:
"It is certain that the productive mould of the Alps, swept off by the
increasing violence of that curse of the mountains, the torrents, is daily
diminishing with fearful rapidity. All our Alps are wholly, or in large
proportion, bared of wood. Their soil, scorched by the sun of Provence, cut
up by the hoofs of the sheep, which, not finding on the surface the grass
they require for their sustenance, gnaw and scratch the ground in search of
Page 329
roots to satisfy their hunger, is periodically washed and carried off by
melting snows and summer storms.
"I will not dwell on the effects of the torrents. For sixty years they have
been too often depicted to require to be further discussed, but it is important
to show that their ravages are daily extending the range of devastation. The
bed of the Durance, which now in some places exceeds a mile and a quarter
in width, and, at ordinary times, has a current of water less than eleven
yards wide, shows something of the extent of the damage." [Footnote: In
the days of the Roman Empire the Durance was a navigable, or at least a
boatable, river, with a commerce so important that the boatmen upon it
formed a distinct corporation.—Ladoucette, Histoire, etc., des Hautes
Alpes, p. 354.
Even as early as 1789 the Durance was computed to have already
covered with gravel and pebbles not less than 130,000 acres, "which, but
for its inundations, would have been the finest land in the province."—
Arthur Young, Travels in France, vol i., ch. i.] Where, ten years ago, there
were still woods and cultivated grounds to be seen, there is now but a vast
torrent; there is not one of our mountains which has not at least one torrent,
and new ones are daily forming.
"An indirect proof of the diminution of the soil is to be found in the
depopulation of the country. In 1852 I reported to the General Council that,
according to the census of that year, the population of the department of the
Lower Alps had fallen off no less than 5,000 souls in the five years between
1846 and 1851.
"Unless prompt and energetic measures are taken, it is easy to fix the
epoch when the French Alps will be but a desert. The interval between 1851
and 1856 will show a further decrease of population. In 1862 the ministry
will announce a continued and progressive reduction, in the number of
melting snows and summer storms.
"I will not dwell on the effects of the torrents. For sixty years they have
been too often depicted to require to be further discussed, but it is important
to show that their ravages are daily extending the range of devastation. The
bed of the Durance, which now in some places exceeds a mile and a quarter
in width, and, at ordinary times, has a current of water less than eleven
yards wide, shows something of the extent of the damage." [Footnote: In
the days of the Roman Empire the Durance was a navigable, or at least a
boatable, river, with a commerce so important that the boatmen upon it
formed a distinct corporation.—Ladoucette, Histoire, etc., des Hautes
Alpes, p. 354.
Even as early as 1789 the Durance was computed to have already
covered with gravel and pebbles not less than 130,000 acres, "which, but
for its inundations, would have been the finest land in the province."—
Arthur Young, Travels in France, vol i., ch. i.] Where, ten years ago, there
were still woods and cultivated grounds to be seen, there is now but a vast
torrent; there is not one of our mountains which has not at least one torrent,
and new ones are daily forming.
"An indirect proof of the diminution of the soil is to be found in the
depopulation of the country. In 1852 I reported to the General Council that,
according to the census of that year, the population of the department of the
Lower Alps had fallen off no less than 5,000 souls in the five years between
1846 and 1851.
"Unless prompt and energetic measures are taken, it is easy to fix the
epoch when the French Alps will be but a desert. The interval between 1851
and 1856 will show a further decrease of population. In 1862 the ministry
will announce a continued and progressive reduction, in the number of
Page 330
acres devoted to agriculture; every year will aggravate the evil and in half a
century France will count more ruins, and a department the less."
Time has verified the predictions of De Bonville. The later census returns
show a progressive diminution in the population of the departments of the
Lower Alps, the Isere, Drome, Ariege, the Upper and the Lower Pyrenees,
Lozere, the Ardennes, Doubs, the Vosges, and, in short, in all the provinces
formerly remarkable for their forests. This diminution is not to be ascribed
to a passion for foreign emigration, as in Ireland, and in parts of Germany
and of Italy; it is simply a transfer of population from one part of the empire
to another, from soils which human folly has rendered uninhabitable, by
ruthlessly depriving them of their natural advantages and securities, to
provinces where the face of the earth was so formed by nature as to need no
such safeguards, and where, consequently, she preserves her outlines in
spite of the wasteful improvidence of man. [Footnote: Between 1851 and
1856 the population of Languedoc and Provence had increased by 101,000
souls. The augmentation, however, was wholly in the provinces of the
plains, where all the principal cities are found. In these provinces the
increase was 204,000, while in the mountain provinces there was a
diminution of 103,000. The reduction of the area of arable land is perhaps
even more striking. In 1842 the department of the Lower Alps possessed
90,000 hectares, or nearly 245,000 acres, of cultivated soil. In 1852 it had
but 74,000 hectares. In other words, in ten years 25,000 hectares, or 61,000
acres, had been washed away, or rendered worthless for cultivation, by
torrents and the abuses of pasturage.—Clave, Etudes, pp. 66, 67.]
Floods of the Ardeche.
The River Ardeche, in the French department of that name, has a
perennial current in a considerable part of its course, and therefore is not,
technically speaking, a torrent; but the peculiar character and violence of its
century France will count more ruins, and a department the less."
Time has verified the predictions of De Bonville. The later census returns
show a progressive diminution in the population of the departments of the
Lower Alps, the Isere, Drome, Ariege, the Upper and the Lower Pyrenees,
Lozere, the Ardennes, Doubs, the Vosges, and, in short, in all the provinces
formerly remarkable for their forests. This diminution is not to be ascribed
to a passion for foreign emigration, as in Ireland, and in parts of Germany
and of Italy; it is simply a transfer of population from one part of the empire
to another, from soils which human folly has rendered uninhabitable, by
ruthlessly depriving them of their natural advantages and securities, to
provinces where the face of the earth was so formed by nature as to need no
such safeguards, and where, consequently, she preserves her outlines in
spite of the wasteful improvidence of man. [Footnote: Between 1851 and
1856 the population of Languedoc and Provence had increased by 101,000
souls. The augmentation, however, was wholly in the provinces of the
plains, where all the principal cities are found. In these provinces the
increase was 204,000, while in the mountain provinces there was a
diminution of 103,000. The reduction of the area of arable land is perhaps
even more striking. In 1842 the department of the Lower Alps possessed
90,000 hectares, or nearly 245,000 acres, of cultivated soil. In 1852 it had
but 74,000 hectares. In other words, in ten years 25,000 hectares, or 61,000
acres, had been washed away, or rendered worthless for cultivation, by
torrents and the abuses of pasturage.—Clave, Etudes, pp. 66, 67.]
Floods of the Ardeche.
The River Ardeche, in the French department of that name, has a
perennial current in a considerable part of its course, and therefore is not,
technically speaking, a torrent; but the peculiar character and violence of its
Page 331
floods is due to the action of the torrents which discharge themselves into it
in its upper valley, and to the rapidity of the flow of the water of
precipitation from the surface of a basin now almost bared of its once
luxuriant woods. [Footnote: The original forests in which the basin of the
Ardeche was rich have been rapidly disappearing for many years, and the
terrific violence of the inundations which are now laying it waste is
ascribed, by the ablest investigators, to that cause. In an article inserted in
the Annales Forestieres for 1843, quoted by Hohenstein, Der Wald, p. 177,
it is said that about one-third of the area of the department had already
become absolutely barren, in consequence of clearing, and that the
destruction of the woods was still going on with great rapidity. New torrents
were constantly forming, and they were estimated to have covered more
than 70,000 acres of good land, or one-eighth of the surface of the
department, with sand and gravel.] A notice of these floods may therefore
not inappropriately be introduced in this place.
The floods of the Ardeche and other mountain streams are attended with
greater immediate danger to life and property than those of rivers of less
rapid flow, because their currents are more impetuous, and they rise more
suddenly and with less previous warning. At the same time, their ravages
are confined within narrower limits, the waters retire sooner to their
accustomed channel, and the danger is more quickly over, than in the case
of inundations of larger rivers. The Ardeche drains a basin of 600,238 acres,
or a little less than nine hundred and thirty-eight square miles. Its remotest
source is about seventy-five miles, in a straight line, from its junction with
the Rhone, and springs at an elevation of four thousand feet above that
point. At the lowest stage of the river, the bed of the Chassezac, its largest
and longest tributary, is in many places completely dry on the surface—the
water being sufficient only to supply the subterranean channels of
infiltration—and the Ardeche itself is almost everywhere fordable, even
below the mouth of the Chassezac. But in floods, the river has sometimes
in its upper valley, and to the rapidity of the flow of the water of
precipitation from the surface of a basin now almost bared of its once
luxuriant woods. [Footnote: The original forests in which the basin of the
Ardeche was rich have been rapidly disappearing for many years, and the
terrific violence of the inundations which are now laying it waste is
ascribed, by the ablest investigators, to that cause. In an article inserted in
the Annales Forestieres for 1843, quoted by Hohenstein, Der Wald, p. 177,
it is said that about one-third of the area of the department had already
become absolutely barren, in consequence of clearing, and that the
destruction of the woods was still going on with great rapidity. New torrents
were constantly forming, and they were estimated to have covered more
than 70,000 acres of good land, or one-eighth of the surface of the
department, with sand and gravel.] A notice of these floods may therefore
not inappropriately be introduced in this place.
The floods of the Ardeche and other mountain streams are attended with
greater immediate danger to life and property than those of rivers of less
rapid flow, because their currents are more impetuous, and they rise more
suddenly and with less previous warning. At the same time, their ravages
are confined within narrower limits, the waters retire sooner to their
accustomed channel, and the danger is more quickly over, than in the case
of inundations of larger rivers. The Ardeche drains a basin of 600,238 acres,
or a little less than nine hundred and thirty-eight square miles. Its remotest
source is about seventy-five miles, in a straight line, from its junction with
the Rhone, and springs at an elevation of four thousand feet above that
point. At the lowest stage of the river, the bed of the Chassezac, its largest
and longest tributary, is in many places completely dry on the surface—the
water being sufficient only to supply the subterranean channels of
infiltration—and the Ardeche itself is almost everywhere fordable, even
below the mouth of the Chassezac. But in floods, the river has sometimes
Page 332
risen more than sixty feet at the Pont d'Arc, a natural arch of two hundred
feet chord, which spans the stream below its junction with all its important
affluents. At the height of the inundation of 1857, the quantity of water
passing this point—after deducting thirty per cent. for material transported
with the current and for irregularity of flow—was estimated at 8,845 cubic
yards to the second, and between twelve o'clock at noon on the 10th of
September of that year and ten o'clock the next morning, the water
discharged through the passage in question amounted to more than
450,000,000 cubic yards. This quantity, distributed equally through the
basin of the river, would cover its entire area to a depth of more than five
inches.
The Ardeche rises so suddenly that, in the inundation of 1846, the women
who were washing in the bed of the river had not time to save their linen,
and barely escaped with their lives, though they instantly fled upon hearing
the roar of the approaching flood. Its waters and those of its affluents fall
almost as rapidly, for in less than twenty-four hours after the rain has ceased
in the Cevennes, where it rises, the Ardeche returns within its ordinary
channel, even at its junction with the Rhone. In the flood of 1772, the water
at La Beaume de Ruoms, on the Beaume, a tributary of the Ardeche, rose
thirty-five feet above low water but the stream was again fordable on the
evening of the same day. The inundation of 1827 was, in this respect,
exceptional, for it continued three days, during which period the Ardeche
poured into the Rhone 1,305,000,000 cubic yards of water.
The Nile delivers into the sea 101,000 cubic feet or 3,741 cubic yards per
second, on an average of the whole year. [Footnote: Sir John F. Herschel,
citing Talabot as his authority, Physical Geography (24).
In an elaborate paper on "Irrigation," printed in the United States Patent
Report for 1860, p. 169, it is stated that the volume of water poured into the
feet chord, which spans the stream below its junction with all its important
affluents. At the height of the inundation of 1857, the quantity of water
passing this point—after deducting thirty per cent. for material transported
with the current and for irregularity of flow—was estimated at 8,845 cubic
yards to the second, and between twelve o'clock at noon on the 10th of
September of that year and ten o'clock the next morning, the water
discharged through the passage in question amounted to more than
450,000,000 cubic yards. This quantity, distributed equally through the
basin of the river, would cover its entire area to a depth of more than five
inches.
The Ardeche rises so suddenly that, in the inundation of 1846, the women
who were washing in the bed of the river had not time to save their linen,
and barely escaped with their lives, though they instantly fled upon hearing
the roar of the approaching flood. Its waters and those of its affluents fall
almost as rapidly, for in less than twenty-four hours after the rain has ceased
in the Cevennes, where it rises, the Ardeche returns within its ordinary
channel, even at its junction with the Rhone. In the flood of 1772, the water
at La Beaume de Ruoms, on the Beaume, a tributary of the Ardeche, rose
thirty-five feet above low water but the stream was again fordable on the
evening of the same day. The inundation of 1827 was, in this respect,
exceptional, for it continued three days, during which period the Ardeche
poured into the Rhone 1,305,000,000 cubic yards of water.
The Nile delivers into the sea 101,000 cubic feet or 3,741 cubic yards per
second, on an average of the whole year. [Footnote: Sir John F. Herschel,
citing Talabot as his authority, Physical Geography (24).
In an elaborate paper on "Irrigation," printed in the United States Patent
Report for 1860, p. 169, it is stated that the volume of water poured into the
Page 333
Mediterranean by the Nile in twenty-four hours, at low water, is
150,566,392,368 cubic meters; at high water, 705,514,667,440 cubic
metres. Taking the mean of these two numbers, the average daily delivery
of the Nile would be 428,081,059,808 cubic metres, or more than
550,000,000,000 cubic yards. There is some enormous mistake, probably a
typographical error, in this statement, which makes the delivery of the Nile
seventeen hundred times as great as computed by Talabot, and more than
physical geographers have estimated the quantity supplied by all the rivers
on the face of the globe.] This is equal to 323,222,400 cubic yards per day.
In a single day of flood, then, the Ardeche, a river too insignificant to be
known except in the local topography of France, contributed to the Rhone
once and a half, and for three consecutive days once and one third, as much
as the average delivery of the Nile during the same periods, though the
basin of the latter river probably contains 1,000,000 square miles of surface,
or more than one thousand times as much as that of the former.
The average annual precipitation in the basin of the Ardeche is not
greater titan in many other parts of Europe, but excessive quantities of rain
frequently fall in that valley in the autumn. On the 9th. of October, 1827,
there fell at Joyeuse, on the Beaume, no less than thirty-one inches between
three o'clock in the morning and midnight. Such facts as this explain the
extraordinary suddenness and violence of the floods of the Ardeche, and the
basins of many other tributaries of the Rhone exhibit meteorological
phenomena not less remarkable. [Footnote: The Drac, a torrent emptying
into the Isere a little below Grenoble, has discharged 5,200, the Isere, which
receives it, 7,800 cubic yards, and the Durance, above its junction with the
Isere, an equal quantity, per second.—Montluisant, Note sur les
Dessechements, etc., Annales des Ponts et Chaussees, 1833, 2me semestre
p. 288.
150,566,392,368 cubic meters; at high water, 705,514,667,440 cubic
metres. Taking the mean of these two numbers, the average daily delivery
of the Nile would be 428,081,059,808 cubic metres, or more than
550,000,000,000 cubic yards. There is some enormous mistake, probably a
typographical error, in this statement, which makes the delivery of the Nile
seventeen hundred times as great as computed by Talabot, and more than
physical geographers have estimated the quantity supplied by all the rivers
on the face of the globe.] This is equal to 323,222,400 cubic yards per day.
In a single day of flood, then, the Ardeche, a river too insignificant to be
known except in the local topography of France, contributed to the Rhone
once and a half, and for three consecutive days once and one third, as much
as the average delivery of the Nile during the same periods, though the
basin of the latter river probably contains 1,000,000 square miles of surface,
or more than one thousand times as much as that of the former.
The average annual precipitation in the basin of the Ardeche is not
greater titan in many other parts of Europe, but excessive quantities of rain
frequently fall in that valley in the autumn. On the 9th. of October, 1827,
there fell at Joyeuse, on the Beaume, no less than thirty-one inches between
three o'clock in the morning and midnight. Such facts as this explain the
extraordinary suddenness and violence of the floods of the Ardeche, and the
basins of many other tributaries of the Rhone exhibit meteorological
phenomena not less remarkable. [Footnote: The Drac, a torrent emptying
into the Isere a little below Grenoble, has discharged 5,200, the Isere, which
receives it, 7,800 cubic yards, and the Durance, above its junction with the
Isere, an equal quantity, per second.—Montluisant, Note sur les
Dessechements, etc., Annales des Ponts et Chaussees, 1833, 2me semestre
p. 288.
Page 334
The Upper Rhone, which drains a basin of about 1,900 square miles,
including seventy-one glaciers, receives many torrential affluents, and rain-
storms and thaws are sometimes extensive enough to affect the whole
tributary system of its narrow valley. In such cases its current swells to a
great volume, but previously to the floods of the autumn of 1868 it was
never known to reach a discharge of 2,600 cubic yards to the second. On the
28th of September in that year, however, its delivery amounted to 3,700
cubic yards to the second, which is about equal to the mean discharge of the
Nile.—Berichte der Experten-Commission uber die Ueberschaeemmungen
im Jahr 1868, pp. 174,175.
The floods of some other French rivers, which have a more or less
torrential character, scarcely fall behind those of the Rhone. The Loire,
above Roanne, has a basin of 2,471 square miles, or about twice and a half
the area of that of the Ardeche. In some of its inundations it has delivered
above 9,500 cubic yards per second, or 400 times its low-water discharge.
—Belgrand, De l'Influence des Forets, etc., Annales des Ponts et Chaussees,
1854, 1er semestre, p.15, note.
The ordinary low-water discharge of the Seine at Paris is nearly 100
cubic yards per second. Belgrand gives a list of eight floods of that river
within the last two centuries, in which it has delivered thirty times that
quantity.]
The Rhone, therefore, is naturally subject to great and sudden
inundations, and the same remark may be applied to most of the principal
rivers of France, because the geographical character of all of them is
approximately the same.
The volume of water in the floods of most great rivers is determined by
the degree in which the inundations of the different tributaries are
coincident in time. Were all the affluents of the Lower Rhone to pour their
including seventy-one glaciers, receives many torrential affluents, and rain-
storms and thaws are sometimes extensive enough to affect the whole
tributary system of its narrow valley. In such cases its current swells to a
great volume, but previously to the floods of the autumn of 1868 it was
never known to reach a discharge of 2,600 cubic yards to the second. On the
28th of September in that year, however, its delivery amounted to 3,700
cubic yards to the second, which is about equal to the mean discharge of the
Nile.—Berichte der Experten-Commission uber die Ueberschaeemmungen
im Jahr 1868, pp. 174,175.
The floods of some other French rivers, which have a more or less
torrential character, scarcely fall behind those of the Rhone. The Loire,
above Roanne, has a basin of 2,471 square miles, or about twice and a half
the area of that of the Ardeche. In some of its inundations it has delivered
above 9,500 cubic yards per second, or 400 times its low-water discharge.
—Belgrand, De l'Influence des Forets, etc., Annales des Ponts et Chaussees,
1854, 1er semestre, p.15, note.
The ordinary low-water discharge of the Seine at Paris is nearly 100
cubic yards per second. Belgrand gives a list of eight floods of that river
within the last two centuries, in which it has delivered thirty times that
quantity.]
The Rhone, therefore, is naturally subject to great and sudden
inundations, and the same remark may be applied to most of the principal
rivers of France, because the geographical character of all of them is
approximately the same.
The volume of water in the floods of most great rivers is determined by
the degree in which the inundations of the different tributaries are
coincident in time. Were all the affluents of the Lower Rhone to pour their
Page 335
highest annual floods into its channel at once—as the smaller tributaries of
the Upper Rhone sometimes do—were a dozen Niles to empty themselves
into its bed at the same moment, its water would rise to a height and rush
with an impetus that would sweep into the Mediterranean the entire
population of its banks, and all the works that man has erected upon the
plains which border it. But such a coincidence can never happen. The
tributaries of this river run in very different directions, and some of them
are swollen principally by the melting of the snows about their sources,
others almost exclusively by heavy rains. When a damp southeast wind
blows up the valley of the Ardeche, its moisture is condensed, and
precipitated in a deluge upon the mountains which embosom the
headwaters of that stream, thus producing a flood, while a neighboring
basin, the axis of which lies transversely or obliquely to that of the Ardeche,
is not at all affected. [Footnote: "There is no example of a coincidence
between great floods of the
Ardeche and of the Rhone, all the known inundations of the former
having taken place when the latter was very low."—MARDIGNY, Memoire
sur les Inondations des Rivieres de l'Ardeche, p. 26.
The same observation may be applied to the tributaries of the Po, their
floods being generally successive, not contemporaneous. The swelling of
the affluents of the Amazon, and indeed of most large rivers, is regulated by
a similar law. See Messedaglia, Analisi dell' opera di Champion, etc., p.
103.
The floods of the affluents of the Tiber form an exception to this law,
being generally coincident, and this is one of the explanations of the
frequency of destructive inundations in that river.—Lombardini, Guida allo
Studio dell' Idrologia, ff. 68; same author, Esame degli studi sul Tevere.
the Upper Rhone sometimes do—were a dozen Niles to empty themselves
into its bed at the same moment, its water would rise to a height and rush
with an impetus that would sweep into the Mediterranean the entire
population of its banks, and all the works that man has erected upon the
plains which border it. But such a coincidence can never happen. The
tributaries of this river run in very different directions, and some of them
are swollen principally by the melting of the snows about their sources,
others almost exclusively by heavy rains. When a damp southeast wind
blows up the valley of the Ardeche, its moisture is condensed, and
precipitated in a deluge upon the mountains which embosom the
headwaters of that stream, thus producing a flood, while a neighboring
basin, the axis of which lies transversely or obliquely to that of the Ardeche,
is not at all affected. [Footnote: "There is no example of a coincidence
between great floods of the
Ardeche and of the Rhone, all the known inundations of the former
having taken place when the latter was very low."—MARDIGNY, Memoire
sur les Inondations des Rivieres de l'Ardeche, p. 26.
The same observation may be applied to the tributaries of the Po, their
floods being generally successive, not contemporaneous. The swelling of
the affluents of the Amazon, and indeed of most large rivers, is regulated by
a similar law. See Messedaglia, Analisi dell' opera di Champion, etc., p.
103.
The floods of the affluents of the Tiber form an exception to this law,
being generally coincident, and this is one of the explanations of the
frequency of destructive inundations in that river.—Lombardini, Guida allo
Studio dell' Idrologia, ff. 68; same author, Esame degli studi sul Tevere.
Page 336
I take this occasion to acknowledge myself indebted to Mardigny's
interesting memoir just quoted for all the statements I make respecting the
floods of the Ardeche, except the comparison of the volume of its water
with that of the Nile.] It is easy to see that the damage occasioned by such
floods as I have described must be almost incalculable, and it is by no
means confined to the effects produced by overflow and the mechanical
force of the superficial currents. In treating of the devastations of torrents, I
have hitherto confined myself principally to the erosion of surface and the
transportation of mineral matter to lower grounds by them. The general
action of torrents, as thus fur shown, tends to the ultimate elevation of their
beds by the deposit of the earth, gravel, and stone conveyed by them; but
until they have thus raised their outlets so as sensibly to diminish the
inclination of their channels—and sometimes when extraordinary floods
give the torrents momentum enough to sweep away the accumulations
which they have themselves heaped up—the swift flow of their currents,
aided by the abrasion of the rolling rocks and gravel, scoops their beds
constantly deeper, and they consequently not only undermine their banks,
but frequently sap the most solid foundations which the art of man can build
for the support of bridges and hydraulic structures. [Footnote: In some cases
where the bed of rapid Alpine streams is composed of very hard rock—as is
the case in many of the valleys once filled by ancient glaciers—and
especially where they are fed by glaciers not overhung by crumbling cliffs,
the channel may remain almost unchanged for centuries. This is observable
in many of the tributaries of the Dora Baltea, which drains the valley of
Aosta. Several of these small rivers are spanned by more or less perfect
Roman bridges—one of which, that over the Lys at Pont St. Martin, is still
in good repair and in constant use. An examination of the rocks on which
the abutments of this and some other similar structures are founded, and of
the channels of the rivers they cross, shows that the beds of the streams
cannot have been much elevated or depressed since the bridges were built.
interesting memoir just quoted for all the statements I make respecting the
floods of the Ardeche, except the comparison of the volume of its water
with that of the Nile.] It is easy to see that the damage occasioned by such
floods as I have described must be almost incalculable, and it is by no
means confined to the effects produced by overflow and the mechanical
force of the superficial currents. In treating of the devastations of torrents, I
have hitherto confined myself principally to the erosion of surface and the
transportation of mineral matter to lower grounds by them. The general
action of torrents, as thus fur shown, tends to the ultimate elevation of their
beds by the deposit of the earth, gravel, and stone conveyed by them; but
until they have thus raised their outlets so as sensibly to diminish the
inclination of their channels—and sometimes when extraordinary floods
give the torrents momentum enough to sweep away the accumulations
which they have themselves heaped up—the swift flow of their currents,
aided by the abrasion of the rolling rocks and gravel, scoops their beds
constantly deeper, and they consequently not only undermine their banks,
but frequently sap the most solid foundations which the art of man can build
for the support of bridges and hydraulic structures. [Footnote: In some cases
where the bed of rapid Alpine streams is composed of very hard rock—as is
the case in many of the valleys once filled by ancient glaciers—and
especially where they are fed by glaciers not overhung by crumbling cliffs,
the channel may remain almost unchanged for centuries. This is observable
in many of the tributaries of the Dora Baltea, which drains the valley of
Aosta. Several of these small rivers are spanned by more or less perfect
Roman bridges—one of which, that over the Lys at Pont St. Martin, is still
in good repair and in constant use. An examination of the rocks on which
the abutments of this and some other similar structures are founded, and of
the channels of the rivers they cross, shows that the beds of the streams
cannot have been much elevated or depressed since the bridges were built.
Page 337
In other cases, as at the outlet of the Val Tournanche at Chatillon, where a
single rib of a Roman bridge still remains, there is nothing to forbid the
supposition that the deep excavation of the channel may have been partly
effected at much later period.
The Roman aqueduct known as the Pont du Gard, near Nismes, was built,
in all probability, nineteen centuries ago. The bed of the river Gardon, a
rather swift stream, which flows beneath it, can have suffered but slight
depression since the piers of the aqueduct were founded.]
In the inundation of 1857, the Ardeche destroyed a stone bridge near La
Beaume, which had been built about eighty years before. The resistance of
the piers, which were erected on piles, the channel at that point being of
gravel, produced an eddying current that washed away the bed of the river
above them, and the foundation, thus deprived of lateral support, yielded to
the weight of the bridge, and the piles and piers fell up-stream.
By a curious law of compensation, the stream which, at flood, scoops out
cavities in its bed, often fills them up again as soon as the diminished
velocity of the current allows it to let fall the sand and gravel with which it
is charged, so that when the waters return to their usual channel, the bottom
shows no sign of having been disturbed. In a flood of the Escontay, a
tributary of the Rhone, in 1846, piles driven sixteen feet into its gravelly
bed for the foundation of a pier were torn up and carried off, and yet, when
the river had fallen to low-water mark, the bottom at that point appeared to
have been raised higher than it was before the flood, by new deposits of
sand and gravel, while the cut stones of the half-built pier were found
buried to a great depth in the excavation which the water had first washed
out. The gravel with which rivers thus restore the level of their beds is
principally derived from the crushing of the rocks brought down by the
mountain torrents, and the destructive effects of inundations are immensely
single rib of a Roman bridge still remains, there is nothing to forbid the
supposition that the deep excavation of the channel may have been partly
effected at much later period.
The Roman aqueduct known as the Pont du Gard, near Nismes, was built,
in all probability, nineteen centuries ago. The bed of the river Gardon, a
rather swift stream, which flows beneath it, can have suffered but slight
depression since the piers of the aqueduct were founded.]
In the inundation of 1857, the Ardeche destroyed a stone bridge near La
Beaume, which had been built about eighty years before. The resistance of
the piers, which were erected on piles, the channel at that point being of
gravel, produced an eddying current that washed away the bed of the river
above them, and the foundation, thus deprived of lateral support, yielded to
the weight of the bridge, and the piles and piers fell up-stream.
By a curious law of compensation, the stream which, at flood, scoops out
cavities in its bed, often fills them up again as soon as the diminished
velocity of the current allows it to let fall the sand and gravel with which it
is charged, so that when the waters return to their usual channel, the bottom
shows no sign of having been disturbed. In a flood of the Escontay, a
tributary of the Rhone, in 1846, piles driven sixteen feet into its gravelly
bed for the foundation of a pier were torn up and carried off, and yet, when
the river had fallen to low-water mark, the bottom at that point appeared to
have been raised higher than it was before the flood, by new deposits of
sand and gravel, while the cut stones of the half-built pier were found
buried to a great depth in the excavation which the water had first washed
out. The gravel with which rivers thus restore the level of their beds is
principally derived from the crushing of the rocks brought down by the
mountain torrents, and the destructive effects of inundations are immensely
Page 338
diminished by this reduction of large stones to minute fragments. If the
blocks hurled down from the cliffs were transported unbroken to the
channels of large rivers, the mechanical force of their movement would be
irresistible. They would overthrow the strongest barriers, spread themselves
over a surface as wide as the flow of the waters, and convert the most
smiling valleys into scenes of the wildest desolation.
As I have before remarked, I have taken my illustrations of the action of
torrents and mountain streams principally from French authorities, because
the facts recorded by them are chiefly of recent occurrence, and as they
have been collected with much care and described with great fulness of
detail, the information furnished by them is not only more trustworthy, but
both more complete and more accessible than that which can be gathered
from any other source. It is not to be supposed, however, that the countries
adjacent to France have escaped the consequences of a like improvidence.
The southern flanks of the Alps, and, in a less degree, the northern slope of
these mountains and the whole chain of the Pyrenees, afford equally
striking examples of the evils resulting from the wanton sacrifice of nature's
safeguards. But I can afford space for few details, and as an illustration of
the extent of these evils in Italy, I shall barely observe that it was calculated
ten years ago that four-tenths of the area of the Ligurian provinces had been
washed away or rendered incapable of cultivation in consequence of the
felling of the woods. [Footnote: Annali di Agricoltura, Industria e
Commercio, vol. i., p. 77. Similar instances of the erosive power of running
water might be collected by hundreds from the narratives of travellers in
warm countries. The energy of the torrents of the Himalayas is such that the
brothers Schlagintweit believe that they will cut gorges through that lofty
chain wide enough to admit the passage of currents of warm wind from the
south, and thereby modify the climate of the countries lying to the north of
the mountains.]
blocks hurled down from the cliffs were transported unbroken to the
channels of large rivers, the mechanical force of their movement would be
irresistible. They would overthrow the strongest barriers, spread themselves
over a surface as wide as the flow of the waters, and convert the most
smiling valleys into scenes of the wildest desolation.
As I have before remarked, I have taken my illustrations of the action of
torrents and mountain streams principally from French authorities, because
the facts recorded by them are chiefly of recent occurrence, and as they
have been collected with much care and described with great fulness of
detail, the information furnished by them is not only more trustworthy, but
both more complete and more accessible than that which can be gathered
from any other source. It is not to be supposed, however, that the countries
adjacent to France have escaped the consequences of a like improvidence.
The southern flanks of the Alps, and, in a less degree, the northern slope of
these mountains and the whole chain of the Pyrenees, afford equally
striking examples of the evils resulting from the wanton sacrifice of nature's
safeguards. But I can afford space for few details, and as an illustration of
the extent of these evils in Italy, I shall barely observe that it was calculated
ten years ago that four-tenths of the area of the Ligurian provinces had been
washed away or rendered incapable of cultivation in consequence of the
felling of the woods. [Footnote: Annali di Agricoltura, Industria e
Commercio, vol. i., p. 77. Similar instances of the erosive power of running
water might be collected by hundreds from the narratives of travellers in
warm countries. The energy of the torrents of the Himalayas is such that the
brothers Schlagintweit believe that they will cut gorges through that lofty
chain wide enough to admit the passage of currents of warm wind from the
south, and thereby modify the climate of the countries lying to the north of
the mountains.]
Page 339
Highly colored as these pictures seem, they are not exaggerated, although
the hasty tourist through Southern France, Switzerland, the Tyrol, and
Northern Italy, finding little in his high-road experiences to justify them,
might suppose them so. The lines of communication by locomotive-train
and diligence lead generally over safer ground, and it is only when they
ascend the Alpine passes and traverse the mountain chains, that scenes
somewhat resembling those just described fall under the eye of the ordinary
traveller. But the extension of the sphere of devastation, by the degradation
of the mountains and the transportation of their debris, is producing
analogous effects upon the lower ridges of the Alps and the plains which
skirt them; and even now one needs but an hour's departure from some great
thoroughfares to reach sites where the genius of destruction revels as wildly
as in the most frightful of the abysses which Blanqui has painted. [Footnote:
The Skalara-Tobel, for instance, near Coire. See the description of this and
other like scenes in Berlepsch, Die Alpen, pp. 169 et seqq., or in Stephen's
English translation.
About an hour from Thusis, on the Splagen road, "opens the awful chasm
of the Nolla which a hundred years ago poured its peaceful waters through
smiling meadows protected by the wooded slopes of the mountains. But the
woods were cut down and with them departed the rich pastures, the pride of
the valley, now covered with piles of rock and rubbish swept down from the
mountains. This result is the more to be lamented as it was entirely
compassed by the improvidence of man in thinning the forests."—Morell,
Scientific Guide to Switzerland, p. 100.
The recent change in the character of the Mella—a river anciently so
remarkable for the gentleness of its current that it was specially noticed by
Catullus as flowing molli flumine—deserves more than a passing remark.
This river rises in the mountain-chain east of Lake Iseo, and traversing the
district of Brescia, empties into the Oglio after a course of about seventy
the hasty tourist through Southern France, Switzerland, the Tyrol, and
Northern Italy, finding little in his high-road experiences to justify them,
might suppose them so. The lines of communication by locomotive-train
and diligence lead generally over safer ground, and it is only when they
ascend the Alpine passes and traverse the mountain chains, that scenes
somewhat resembling those just described fall under the eye of the ordinary
traveller. But the extension of the sphere of devastation, by the degradation
of the mountains and the transportation of their debris, is producing
analogous effects upon the lower ridges of the Alps and the plains which
skirt them; and even now one needs but an hour's departure from some great
thoroughfares to reach sites where the genius of destruction revels as wildly
as in the most frightful of the abysses which Blanqui has painted. [Footnote:
The Skalara-Tobel, for instance, near Coire. See the description of this and
other like scenes in Berlepsch, Die Alpen, pp. 169 et seqq., or in Stephen's
English translation.
About an hour from Thusis, on the Splagen road, "opens the awful chasm
of the Nolla which a hundred years ago poured its peaceful waters through
smiling meadows protected by the wooded slopes of the mountains. But the
woods were cut down and with them departed the rich pastures, the pride of
the valley, now covered with piles of rock and rubbish swept down from the
mountains. This result is the more to be lamented as it was entirely
compassed by the improvidence of man in thinning the forests."—Morell,
Scientific Guide to Switzerland, p. 100.
The recent change in the character of the Mella—a river anciently so
remarkable for the gentleness of its current that it was specially noticed by
Catullus as flowing molli flumine—deserves more than a passing remark.
This river rises in the mountain-chain east of Lake Iseo, and traversing the
district of Brescia, empties into the Oglio after a course of about seventy
Page 340
miles. The iron-works in the upper valley of the Mella had long created a
considerable demand for wood, but their operations were not so extensive
as to occasion any very sudden or general destruction of the forests, and the
only evil experienced from the clearings was the gradual diminution of the
volume of the river. Within the last thirty years, the superior quality of the
arms manufactured at Brescia has greatly enlarged the sale of them, and
very naturally stumulated the activity of both the forges and of the colliers
who supply them, and the hillsides have been rapidly stripped of their
timber. Up to 1850, no destructive inundation of the Mella had been
recorded. Buildings in great numbers had been erected upon its margin, and
its valley was conspicuous for its rural beauty and its fertility. But when the
denudation of the mountains had reached a certain point, avenging nature
began the work of retribution. In the spring and summer of 1850 several
new torrents were suddenly formed in the upper tributary valleys, and on
the 14th and 15th of August in that year a fall of rain, not heavier than had
been often experienced, produced a flood which not only inundated much
ground never before overflowed, but destroyed a great number of bridges,
dams, factories, and other valuable structures, and, what was a far more
serious evil, swept off from the rocks an incredible extent of soil, and
converted one of the most beautiful valleys of the Italian Alps into a ravine
almost us bare and as barren as the savagest gorge of Southern France. The
pecuniary damage was estimated at many millions of francs, and the
violence of the catastrophe was deemed so extraordinary, even in a country
subject to similar visitations, that the sympathy excited for the sufferers
produced, in five months, voluntary contributions for their relief to the
amount of nearly $200,000.—Delle Inondazioni del Mella, etc., nella notte
del 14 al 15 Agosto, 1850.
The author of this pamphlet has chosen as a motto a passage from the
Vulgate translation of Job, which is interesting as showing accurate
observation of the action of the torrent: "Mons cadens definit, et saxum
considerable demand for wood, but their operations were not so extensive
as to occasion any very sudden or general destruction of the forests, and the
only evil experienced from the clearings was the gradual diminution of the
volume of the river. Within the last thirty years, the superior quality of the
arms manufactured at Brescia has greatly enlarged the sale of them, and
very naturally stumulated the activity of both the forges and of the colliers
who supply them, and the hillsides have been rapidly stripped of their
timber. Up to 1850, no destructive inundation of the Mella had been
recorded. Buildings in great numbers had been erected upon its margin, and
its valley was conspicuous for its rural beauty and its fertility. But when the
denudation of the mountains had reached a certain point, avenging nature
began the work of retribution. In the spring and summer of 1850 several
new torrents were suddenly formed in the upper tributary valleys, and on
the 14th and 15th of August in that year a fall of rain, not heavier than had
been often experienced, produced a flood which not only inundated much
ground never before overflowed, but destroyed a great number of bridges,
dams, factories, and other valuable structures, and, what was a far more
serious evil, swept off from the rocks an incredible extent of soil, and
converted one of the most beautiful valleys of the Italian Alps into a ravine
almost us bare and as barren as the savagest gorge of Southern France. The
pecuniary damage was estimated at many millions of francs, and the
violence of the catastrophe was deemed so extraordinary, even in a country
subject to similar visitations, that the sympathy excited for the sufferers
produced, in five months, voluntary contributions for their relief to the
amount of nearly $200,000.—Delle Inondazioni del Mella, etc., nella notte
del 14 al 15 Agosto, 1850.
The author of this pamphlet has chosen as a motto a passage from the
Vulgate translation of Job, which is interesting as showing accurate
observation of the action of the torrent: "Mons cadens definit, et saxum
Page 341
transfertur de loco suo; lapides excavant aquae et alluvione paullatim terra
consumitur."—Job xiv. 18, 19.
The English version is much less striking, and gives a different sense.
The recent date of the change in the character of the Mella is contested,
and it is possible that, though the extent of the revolution is not
exaggerated, the rapidity with which it has taken place may have been.]
There is one effect of the action of torrents which few travellers on the
Continent are heedless enough to pass without notice. I refer to the
elevation of the beds of mountain streams in consequence of the deposit of
the debris with which they are charged. To prevent the spread of sand and
gravel over the fields and the deluging overflow of the raging waters, the
streams are confined by walls and embankments, which are gradually built
higher and higher as the bed of the torrent is raised, so that, to reach a river,
you ascend from the fields beside it; and sometimes the ordinary level of
the stream is above the streets and even the roofs of the towns through
which it passes. [Footnote: Streffleur quotes from Duile the following
observations: "The channel of the Tyrelese brooks is often raised much
above the valleys through which they flow. The bed of the Fersina is
elevated high above the city of Trent, which lies near it. The Villerbach
flows at a much more elevated level than that of the market-place of
Neumarkt and Vill, and threatens to overwhelm both of them with its
waters. The Talfer at Botzen is at least even with the roofs of the adjacent
town, if not above them. The tower-steeples of the villages of Schlanders,
Kortsch, and Laas, are lower than the surface of the Gadribach. The
Saldurbach at Schluderus menaces the far lower village with destruction,
and the chief town, Schwaz, is in similar danger from the Lahnbach."—
Streffleur, Ueber die Wildbuche, etc., p. 7.] The traveller who visits the
depths of an Alpine ravine, observes the length and width of the gorge and
consumitur."—Job xiv. 18, 19.
The English version is much less striking, and gives a different sense.
The recent date of the change in the character of the Mella is contested,
and it is possible that, though the extent of the revolution is not
exaggerated, the rapidity with which it has taken place may have been.]
There is one effect of the action of torrents which few travellers on the
Continent are heedless enough to pass without notice. I refer to the
elevation of the beds of mountain streams in consequence of the deposit of
the debris with which they are charged. To prevent the spread of sand and
gravel over the fields and the deluging overflow of the raging waters, the
streams are confined by walls and embankments, which are gradually built
higher and higher as the bed of the torrent is raised, so that, to reach a river,
you ascend from the fields beside it; and sometimes the ordinary level of
the stream is above the streets and even the roofs of the towns through
which it passes. [Footnote: Streffleur quotes from Duile the following
observations: "The channel of the Tyrelese brooks is often raised much
above the valleys through which they flow. The bed of the Fersina is
elevated high above the city of Trent, which lies near it. The Villerbach
flows at a much more elevated level than that of the market-place of
Neumarkt and Vill, and threatens to overwhelm both of them with its
waters. The Talfer at Botzen is at least even with the roofs of the adjacent
town, if not above them. The tower-steeples of the villages of Schlanders,
Kortsch, and Laas, are lower than the surface of the Gadribach. The
Saldurbach at Schluderus menaces the far lower village with destruction,
and the chief town, Schwaz, is in similar danger from the Lahnbach."—
Streffleur, Ueber die Wildbuche, etc., p. 7.] The traveller who visits the
depths of an Alpine ravine, observes the length and width of the gorge and
Page 342
the great height and apparent solidity of the precipitous walls which bound
it, and calculates the mass of rock required to fill the vacancy, can hardly
believe that the humble brooklet which purls at his feet has been the
principal agent in accomplishing this tremendous erosion. Closer
observation will often teach him, that the seemingly unbroken rock which
overhangs the valley is full of cracks and fissures, and really in such a state
of disintegration that every frost must bring down tons of it. If he computes
the area of the basin which finds here its only discharge, he will perceive
that a sudden thaw of the winter's deposit of snow, or one of those terrible
discharges of rain so common in the Alps, must send forth a deluge mighty
enough to sweep down the largest masses of gravel and of rock. The simple
measurement of the cubical contents of the semicircular hillock which he
climbed before he entered the gorge, the structure and composition of which
conclusively show that it must have been washed out of this latter by
torrential action, will often account satisfactorily for the disposal of most of
the matter which once filled the ravine. When a torrent escapes from the
lateral confinement of its mountain walls and pours out of the gorge, it
spreads and divides itself into numerous smaller streams which shoot out
from the mouth of the ravine as from a centre, in different directions, like
the ribs of a fan from the pivot, each carrying with it its quota of stones and
gravel. The plain below the point of issue from the mountain is rapidly
raised by newly-formed torrents, the elevation depending on the inclination
of the bed and the form and weight of the matter transported. Every flood
both increases the height of this central point and extends the entire
circumference of the deposit. Other things being equal, the transporting
power of the water is greatest where its flow is most rapid. This is usually in
the direction of the axis of the ravine. The stream retaining most nearly this
direction moves with the greatest momentum, and consequently transports
the solid matter with which it is charged to the greatest distance.
it, and calculates the mass of rock required to fill the vacancy, can hardly
believe that the humble brooklet which purls at his feet has been the
principal agent in accomplishing this tremendous erosion. Closer
observation will often teach him, that the seemingly unbroken rock which
overhangs the valley is full of cracks and fissures, and really in such a state
of disintegration that every frost must bring down tons of it. If he computes
the area of the basin which finds here its only discharge, he will perceive
that a sudden thaw of the winter's deposit of snow, or one of those terrible
discharges of rain so common in the Alps, must send forth a deluge mighty
enough to sweep down the largest masses of gravel and of rock. The simple
measurement of the cubical contents of the semicircular hillock which he
climbed before he entered the gorge, the structure and composition of which
conclusively show that it must have been washed out of this latter by
torrential action, will often account satisfactorily for the disposal of most of
the matter which once filled the ravine. When a torrent escapes from the
lateral confinement of its mountain walls and pours out of the gorge, it
spreads and divides itself into numerous smaller streams which shoot out
from the mouth of the ravine as from a centre, in different directions, like
the ribs of a fan from the pivot, each carrying with it its quota of stones and
gravel. The plain below the point of issue from the mountain is rapidly
raised by newly-formed torrents, the elevation depending on the inclination
of the bed and the form and weight of the matter transported. Every flood
both increases the height of this central point and extends the entire
circumference of the deposit. Other things being equal, the transporting
power of the water is greatest where its flow is most rapid. This is usually in
the direction of the axis of the ravine. The stream retaining most nearly this
direction moves with the greatest momentum, and consequently transports
the solid matter with which it is charged to the greatest distance.
Page 343
The untravelled reader will comprehend this the better when he is
informed that the southern slope of the Alps generally rises suddenly out of
the plain, with no intervening hill to break the abruptness of the transition,
except those consisting of comparatively small heaps of its own debris
brought down by ancient glaciers or recent torrents. The torrents do not
wind down valleys gradually widening to the rivers or the sea, but leap at
once from the flanks of the mountains upon the plains below. This
arrangement of surfaces naturally facilitates the formation of vast deposits
at their points of emergence, and the centre of the accumulation in the case
of very small torrents is not unfrequently a hundred feet high, and
sometimes very much more.
The deposits of the torrent which has scooped out the Nantzen Thal, a
couple of miles below Brieg in the Valais, have built up a semicircular
hillock, which most travellers by the Simplon route pass over without even
noticing it, though it is little inferior in dimensions to the great cones of
dejection described by Blanqui. The principal course of the torrent having
been—I know not whether spontaneously or artificially—diverted towards
the west, the eastern part of the hill has been gradually brought under
cultivation, and there are many trees, fields, and houses upon it; but the
larger western part is furrowed with channels diverging from the summit of
the deposit at the outlet of the Nantzen Thal, which serve as the beds of the
water-courses into which the torrent has divided itself. All this portion of
the hillock is subject to inundation after long and heavy rain, and as I saw it
in the great flood of October, 1866, almost its whole surface seemed
covered with an unbrokun sheet of rushing water.
The semi-conical deposit of detritus at the mouth of the Litznerthal, a
lateral branch of the valley of the Adige, at the point where the torrent pours
out of the gorge, is a thousand feet high and, measuring along the axis of
the principal current, two and a half miles long. [Footnote: Sonklar, Die
informed that the southern slope of the Alps generally rises suddenly out of
the plain, with no intervening hill to break the abruptness of the transition,
except those consisting of comparatively small heaps of its own debris
brought down by ancient glaciers or recent torrents. The torrents do not
wind down valleys gradually widening to the rivers or the sea, but leap at
once from the flanks of the mountains upon the plains below. This
arrangement of surfaces naturally facilitates the formation of vast deposits
at their points of emergence, and the centre of the accumulation in the case
of very small torrents is not unfrequently a hundred feet high, and
sometimes very much more.
The deposits of the torrent which has scooped out the Nantzen Thal, a
couple of miles below Brieg in the Valais, have built up a semicircular
hillock, which most travellers by the Simplon route pass over without even
noticing it, though it is little inferior in dimensions to the great cones of
dejection described by Blanqui. The principal course of the torrent having
been—I know not whether spontaneously or artificially—diverted towards
the west, the eastern part of the hill has been gradually brought under
cultivation, and there are many trees, fields, and houses upon it; but the
larger western part is furrowed with channels diverging from the summit of
the deposit at the outlet of the Nantzen Thal, which serve as the beds of the
water-courses into which the torrent has divided itself. All this portion of
the hillock is subject to inundation after long and heavy rain, and as I saw it
in the great flood of October, 1866, almost its whole surface seemed
covered with an unbrokun sheet of rushing water.
The semi-conical deposit of detritus at the mouth of the Litznerthal, a
lateral branch of the valley of the Adige, at the point where the torrent pours
out of the gorge, is a thousand feet high and, measuring along the axis of
the principal current, two and a half miles long. [Footnote: Sonklar, Die
Page 344
Octzthaler Gebirgsgruppe, 1861, p. 231.] The solid material of this hillock
—which it is hardly an exaggeration to call a mountain, the work of a single
insignificant torrent and its tributaries—including what the river which
washes its base has carried off in a comparatively few years, probably
surpasses the mass of the stupendous pyramid of the Matterhorn. In valleys
of ancient geological formation, which extend into the very heart of the
mountains, the streams, though rapid, have often lost the true torrential
character, if, indeed, they ever possessed it. Their beds have become
approximately constant, and their walls no longer crumble and fall into the
waters that wash their bases. The torrent-worn ravines, of which I have
spoken, are of later date, and belong more properly to what may be called
the crust of the Alps, consisting of loose rocks, of gravel, and of earth,
strewed along the surface of the great declivities of the central ridge, and
accumulated thickly between their solid buttresses. But it is on this crust
that the mountaineer dwells. Here are his forests, here his pastures, and the
ravages of the torrent both destroy his world, and convert it into a source of
overwhelming desolation to the plains below.
I do not mean to assert that all the rocky valleys of the Alps have been
produced by the action of torrents resulting from the destruction of the
forests. The greater, and many of the smaller channels, by which that chain
is drained, owe their origin to higher causes. They are primitive fissures,
ascribable to disruption in upheaval or other geological convulsion,
widened and scarped, and often even polished, so to speak, by the action of
glaciers during the ice period, and but little changed in form by running
water in later eras.
It has been contended that all rivers which take their rise in mountains
originated in torrents. These, it is said, have lowered the summits by
gradual erosion, and, with the material thus derived, have formed shoals in
the sea which once beat against the cliffs; then, by successive deposits,
—which it is hardly an exaggeration to call a mountain, the work of a single
insignificant torrent and its tributaries—including what the river which
washes its base has carried off in a comparatively few years, probably
surpasses the mass of the stupendous pyramid of the Matterhorn. In valleys
of ancient geological formation, which extend into the very heart of the
mountains, the streams, though rapid, have often lost the true torrential
character, if, indeed, they ever possessed it. Their beds have become
approximately constant, and their walls no longer crumble and fall into the
waters that wash their bases. The torrent-worn ravines, of which I have
spoken, are of later date, and belong more properly to what may be called
the crust of the Alps, consisting of loose rocks, of gravel, and of earth,
strewed along the surface of the great declivities of the central ridge, and
accumulated thickly between their solid buttresses. But it is on this crust
that the mountaineer dwells. Here are his forests, here his pastures, and the
ravages of the torrent both destroy his world, and convert it into a source of
overwhelming desolation to the plains below.
I do not mean to assert that all the rocky valleys of the Alps have been
produced by the action of torrents resulting from the destruction of the
forests. The greater, and many of the smaller channels, by which that chain
is drained, owe their origin to higher causes. They are primitive fissures,
ascribable to disruption in upheaval or other geological convulsion,
widened and scarped, and often even polished, so to speak, by the action of
glaciers during the ice period, and but little changed in form by running
water in later eras.
It has been contended that all rivers which take their rise in mountains
originated in torrents. These, it is said, have lowered the summits by
gradual erosion, and, with the material thus derived, have formed shoals in
the sea which once beat against the cliffs; then, by successive deposits,
Page 345
gradually raised them above the surface, and finally expanded them into
broad plains traversed by gently flowing streams. If we could get back to
earlier geological periods, we should find this theory often verified, and we
cannot fail to see that the torrents go on at the present hour, depressing still
lower the ridges of the Alps and the Apennines, raising still higher the
plains of Lombardy and Provence, extending the coast still farther into the
Adriatic and the Mediterranean, reducing the inclination of their own beds
and the rapidity of their flow, and thus tending to become river-like in
character.
We cannot measure the share which human action has had in augmenting
the intensity of causes of mountain degradation, and of the formation of
plains and marshes below, but we know that the clearing of the woods has,
in some cases, produced, within two or three generations, effects as blasting
as those generally ascribed to geological convulsions, and has laid waste the
face of the earth more hopelessly than if it had been buried by a current of
lava or a shower of volcanic sand. New torrents are forming every year in
the Alps. Tradition, written records, and analogy concur to establish the
belief that the ruin of most of the now desolate valleys in those mountains is
to be ascribed to the same cause, and authentic descriptions of the
irresistible force of the torrent show that, aided by frost and heat, it is
adequate to level Mont Blanc and Monte Rosa themselves, unless new
upheavals shall maintain their elevation.
There are cases where torrents cease their ravages of themselves, in
consequence of some change in the condition of the basin where they
originate, or of the face of the mountain at a higher level, while the plain or
the sea below remains in substantially the same state as before. If a torrent
rises in a small valley containing no great amount of earth and of
disintegrated or loose rock, it may, in the course of a certain period, wash
out all the transportable material, and if the valley is then left with solid
broad plains traversed by gently flowing streams. If we could get back to
earlier geological periods, we should find this theory often verified, and we
cannot fail to see that the torrents go on at the present hour, depressing still
lower the ridges of the Alps and the Apennines, raising still higher the
plains of Lombardy and Provence, extending the coast still farther into the
Adriatic and the Mediterranean, reducing the inclination of their own beds
and the rapidity of their flow, and thus tending to become river-like in
character.
We cannot measure the share which human action has had in augmenting
the intensity of causes of mountain degradation, and of the formation of
plains and marshes below, but we know that the clearing of the woods has,
in some cases, produced, within two or three generations, effects as blasting
as those generally ascribed to geological convulsions, and has laid waste the
face of the earth more hopelessly than if it had been buried by a current of
lava or a shower of volcanic sand. New torrents are forming every year in
the Alps. Tradition, written records, and analogy concur to establish the
belief that the ruin of most of the now desolate valleys in those mountains is
to be ascribed to the same cause, and authentic descriptions of the
irresistible force of the torrent show that, aided by frost and heat, it is
adequate to level Mont Blanc and Monte Rosa themselves, unless new
upheavals shall maintain their elevation.
There are cases where torrents cease their ravages of themselves, in
consequence of some change in the condition of the basin where they
originate, or of the face of the mountain at a higher level, while the plain or
the sea below remains in substantially the same state as before. If a torrent
rises in a small valley containing no great amount of earth and of
disintegrated or loose rock, it may, in the course of a certain period, wash
out all the transportable material, and if the valley is then left with solid
Page 346
walls, it will cease to furnish debris to be carried down by floods. If, in this
state of things, a new channel be formed at an elevation above the head of
the valley, it may divert a part or even the whole of the rain-water and
melted snow which would otherwise have flowed into it, and the once
furious torrent now sinks to the rank of a humble and harmless brooklet. "In
traversing this department," says Suroll, "one often sees, at the outlet of a
gorge, a flattened hillock, with a fan-shaped outline and regular slopes; it is
the bed of dejection of an ancient torrent. It sometimes requires long and
careful study to detect the primitive form, masked as it is by groves of trees,
by cultivated fields, and often by houses, but, when examined closely, and
from different points of view, its characteristic figure manifestly appears,
and its true history cannot be mistaken. Along the hillock flows a streamlet,
issuing from the ravine, and quietly watering the fields. This was originally
a torrent, and in the background may be discovered its mountain basin.
Such EXTINGUISHED torrents, if I may use the expression, are
numerous." [Footnote: Surrell, Les Torrents des Hautes Alpes, chap. xxiv.
In such cases, the clearing of the ground, which, in consequence of a
temporary diversion of the waters, or from some other cause, has become
rewooded, sometimes renews the ravages of the torrent. Thus, on the left
bank of the Durance, a wooded declivity had been formed by the debris
brought down by torrents, which had extinguished themselves after having
swept off much of the superficial strata of the mountain of Morgon. "All
this district was covered with woods, which have now been thinned out and
are perishing from day to day; consequently, the torrents have
recommenced their devastations, and if the clearings continue, this
declivity, now fertile, will he ruined, like so many others."—Ibid, p. 155.]
But for the intervention of man and domestic animals, these latter
beneficent revolutions would occur more frequently, proceed more rapidly.
The new scarped mountains, the hillocks of debris, the plains elevated by
sand and gravel spread over them, the shores freshly formed by fluviatile
state of things, a new channel be formed at an elevation above the head of
the valley, it may divert a part or even the whole of the rain-water and
melted snow which would otherwise have flowed into it, and the once
furious torrent now sinks to the rank of a humble and harmless brooklet. "In
traversing this department," says Suroll, "one often sees, at the outlet of a
gorge, a flattened hillock, with a fan-shaped outline and regular slopes; it is
the bed of dejection of an ancient torrent. It sometimes requires long and
careful study to detect the primitive form, masked as it is by groves of trees,
by cultivated fields, and often by houses, but, when examined closely, and
from different points of view, its characteristic figure manifestly appears,
and its true history cannot be mistaken. Along the hillock flows a streamlet,
issuing from the ravine, and quietly watering the fields. This was originally
a torrent, and in the background may be discovered its mountain basin.
Such EXTINGUISHED torrents, if I may use the expression, are
numerous." [Footnote: Surrell, Les Torrents des Hautes Alpes, chap. xxiv.
In such cases, the clearing of the ground, which, in consequence of a
temporary diversion of the waters, or from some other cause, has become
rewooded, sometimes renews the ravages of the torrent. Thus, on the left
bank of the Durance, a wooded declivity had been formed by the debris
brought down by torrents, which had extinguished themselves after having
swept off much of the superficial strata of the mountain of Morgon. "All
this district was covered with woods, which have now been thinned out and
are perishing from day to day; consequently, the torrents have
recommenced their devastations, and if the clearings continue, this
declivity, now fertile, will he ruined, like so many others."—Ibid, p. 155.]
But for the intervention of man and domestic animals, these latter
beneficent revolutions would occur more frequently, proceed more rapidly.
The new scarped mountains, the hillocks of debris, the plains elevated by
sand and gravel spread over them, the shores freshly formed by fluviatile
Page 347
deposits, would clothe themselves with shrubs and trees, the intensity of the
causes of degradation would be diminished, and nature would thus regain
her ancient equilibrium. But these processes, under ordinary circumstances,
demand, not years, generations, but centuries; [Footnote: Where a torrent
has not been long in operation, and earth still remains mixed with the rocks
and gravel it heaps up at its point of eruption, vegetation soon starts up and
prospers, it protected from encroachment. In Provence, "several communes
determined, about ten years ago, to reserve the soils thus wasted, that is, to
abandon them for a certain time, to spontaneous vegetation, which was not
slow in making its appearance."-Becquerel, Des Climats, p. 815.] and man,
who even now finds scarce breathing-room on this vast globe, cannot retire
from the Old World to some yet undiscovered continent, and wait for the
slow action of such causes to replace, by a new creation, the Eden he has
wasted.
Crushing Force of Torrents.
I must here notice a mechanical effect of the rapid flow of the torrent,
which is of much importance in relation to the desolating action it exercises
by covering large tracts of cultivated ground with infertile material. The
torrent, as we have seen, shoots or rolls forwards, with great velocity,
masses and fragments of rock, and sometimes rounded pebbles from more
ancient formations. Every inch of this violent movement is accompanied
with crushing concussion, or, at least, with great abrasion of the mineral
material, and, as you follow it along the course of the waters which
transport it, you find the stones gradually rounding off in form, and
diminishing in size, until they pass successively into gravel, and, in the beds
of the rivers to which the torrents convey it, sand, and lastly impalpable
slime.
causes of degradation would be diminished, and nature would thus regain
her ancient equilibrium. But these processes, under ordinary circumstances,
demand, not years, generations, but centuries; [Footnote: Where a torrent
has not been long in operation, and earth still remains mixed with the rocks
and gravel it heaps up at its point of eruption, vegetation soon starts up and
prospers, it protected from encroachment. In Provence, "several communes
determined, about ten years ago, to reserve the soils thus wasted, that is, to
abandon them for a certain time, to spontaneous vegetation, which was not
slow in making its appearance."-Becquerel, Des Climats, p. 815.] and man,
who even now finds scarce breathing-room on this vast globe, cannot retire
from the Old World to some yet undiscovered continent, and wait for the
slow action of such causes to replace, by a new creation, the Eden he has
wasted.
Crushing Force of Torrents.
I must here notice a mechanical effect of the rapid flow of the torrent,
which is of much importance in relation to the desolating action it exercises
by covering large tracts of cultivated ground with infertile material. The
torrent, as we have seen, shoots or rolls forwards, with great velocity,
masses and fragments of rock, and sometimes rounded pebbles from more
ancient formations. Every inch of this violent movement is accompanied
with crushing concussion, or, at least, with great abrasion of the mineral
material, and, as you follow it along the course of the waters which
transport it, you find the stones gradually rounding off in form, and
diminishing in size, until they pass successively into gravel, and, in the beds
of the rivers to which the torrents convey it, sand, and lastly impalpable
slime.
Page 348
There are few operations of nature where the effect seems more
disproportioned to the cause than in the crushing and comminution of rock
in the channel of swift waters. Igneous rocks are generally so hard as to be
wrought with great difficulty, and they bear the weight of enormous
superstructures without yielding to the pressure; but to the torrent they are
as wheat to the millstone. The streams which pour down the southern scarp
of the Mediterranean Alps along the Riviera di Ponente, near Genoa, have
short courses, and a brisk walk of a couple of hours or even less takes you
from the sea-beach to the headspring of many of them. In their heaviest
floods, they bring rounded masses of serpentine quite down to the sea, but
at ordinary high water their lower course is charged only with finely divided
particles of that rock. Hence, while, near their sources, their channels are
filled with pebbles and angular fragments, intermixed with a little gravel,
the proportions are reversed near their months, and, just above the points
where their outlets are partially choked by the rolling shingle of the beach,
their beds are composed of sand and gravel to the almost total exclusion of
pebbles.
Guglielmini argued that the gravel and sand of the beds of running
streams were derived from the trituration of rocks by the action of the
currents, and inferred that this action was generally sufficient to reduce hard
rock to sand in its passage from the source to the outlet of rivers. Frisi
controverted this opinion, and maintained that river-sand was of more
ancient origin, and he inferred from experiments in artificially grinding
stones that the concussion, friction, and attrition of rock in the channel of
running waters were inadequate to its comminution, though he admitted that
these same causes might reduce silicious sand to a fine powder capable of
transportation to the sea by the currents. [Footnote: Frisi, Del modo di
regolare i Fiumi e i Torrenti, pp. 4-19. See in Lombardini, Sulle Inondazioni
in Francia, p. 87, notices of the action of currents transporting only fine
material in wearing down hard rock. In the sluices for gold-washing in
disproportioned to the cause than in the crushing and comminution of rock
in the channel of swift waters. Igneous rocks are generally so hard as to be
wrought with great difficulty, and they bear the weight of enormous
superstructures without yielding to the pressure; but to the torrent they are
as wheat to the millstone. The streams which pour down the southern scarp
of the Mediterranean Alps along the Riviera di Ponente, near Genoa, have
short courses, and a brisk walk of a couple of hours or even less takes you
from the sea-beach to the headspring of many of them. In their heaviest
floods, they bring rounded masses of serpentine quite down to the sea, but
at ordinary high water their lower course is charged only with finely divided
particles of that rock. Hence, while, near their sources, their channels are
filled with pebbles and angular fragments, intermixed with a little gravel,
the proportions are reversed near their months, and, just above the points
where their outlets are partially choked by the rolling shingle of the beach,
their beds are composed of sand and gravel to the almost total exclusion of
pebbles.
Guglielmini argued that the gravel and sand of the beds of running
streams were derived from the trituration of rocks by the action of the
currents, and inferred that this action was generally sufficient to reduce hard
rock to sand in its passage from the source to the outlet of rivers. Frisi
controverted this opinion, and maintained that river-sand was of more
ancient origin, and he inferred from experiments in artificially grinding
stones that the concussion, friction, and attrition of rock in the channel of
running waters were inadequate to its comminution, though he admitted that
these same causes might reduce silicious sand to a fine powder capable of
transportation to the sea by the currents. [Footnote: Frisi, Del modo di
regolare i Fiumi e i Torrenti, pp. 4-19. See in Lombardini, Sulle Inondazioni
in Francia, p. 87, notices of the action of currents transporting only fine
material in wearing down hard rock. In the sluices for gold-washing in
Page 349
California having a grade of 1 to 14 1/2, and paved with the hardest stones,
the wear of the bottom is at the rate of two inches in three months.—
Raymond, Mineral Statistics, 1870, p. 480.] Frisi's experiments were tried
upon rounded and polished river-pebbles, and prove nothing with regard to
the action of torrents upon the irregular, more or less weathered, and often
cracked and shattered rocks which lie loose in the ground at the head of
mountain valleys. The fury of the waters and of the wind which
accompanies them in the floods of the French Alpine torrents is such, that
large blocks of stone are hurled out of the bed of the stream to the height of
twelve or thirteen feet. [Footnote: Surrell, Etude sur les Torrents, pp. 81-
86.] The impulse of masses driven with such force overthrows the most
solid masonry, and their concussion cannot fail to be attended with the
crushing of the rocks themselves.
the wear of the bottom is at the rate of two inches in three months.—
Raymond, Mineral Statistics, 1870, p. 480.] Frisi's experiments were tried
upon rounded and polished river-pebbles, and prove nothing with regard to
the action of torrents upon the irregular, more or less weathered, and often
cracked and shattered rocks which lie loose in the ground at the head of
mountain valleys. The fury of the waters and of the wind which
accompanies them in the floods of the French Alpine torrents is such, that
large blocks of stone are hurled out of the bed of the stream to the height of
twelve or thirteen feet. [Footnote: Surrell, Etude sur les Torrents, pp. 81-
86.] The impulse of masses driven with such force overthrows the most
solid masonry, and their concussion cannot fail to be attended with the
crushing of the rocks themselves.
Page 350
The greatest depth of the basin of the Ardeche is seventy-five miles, but
most of its tributaries have a much shorter course. "These affluents," says
Mardigny, "hurl into the bed of the Ardeche enormous blocks of rock,
which this river, in its turn bears onwards, and grinds down, at high water,
so that its current rolls only gravel at its confluence with the Rhone."
[Footnote: At Rinkenberg, on the right bank of the Vorder Rhein, in the
flood of 1868, a block of stone computed to weigh nearly 9,000 cwt. was
carried bodily forwards, not rolled, by a torrent, a distance of three-quarter
of a mile.—Coaz, die Hochwasser im 1868, p. 54.
Memoire sur les Inondations des Rivieres de l'Ardeche, p. 16. "The
terrific roar, the thunder of the raging torrents proceeds principally from the
stones which are rolled along in the bed of the stream. This movement is
attended with such powerful attrition that, in the Southern Alps, the
atmosphere of valleys where the limestone contains bitumen, has, at the
time of floods, the marked bituminous smell produced by rubbing pieces of
such limestone together."—Wessely, Die Oesterreichischen Alpenlander, i.,
p. 113.] Duponchel makes the following remarkable statement: "The river
Herault rises in a granitic region, but soon reaches calcareous formations,
which it traverses for more than sixty kilometres, rolling through deep and
precipitous ravines, into which the torrents are constantly discharging
enormous masses of pebbles belonging to the hardest rocks of the Jurassian
period. These debris, continually renewed, compose, even below the exit of
the gorge where the river enters into a regular channel cut in a tertiary
deposit, broad beaches, prodigious accumulations of rolled pebbles,
extending several kilometres down the stream, but they diminish in size and
weight so rapidly that above the mouth of the river, which is at a distance of
thirty or thirty-five kilometres from the gorge, every trace of calcareous
matter has disappeared from the sands of the bottom, which are exclusively
silicious." [Footnote: Avant-projet pour la creation d'un sol fertile, p. 20.]
most of its tributaries have a much shorter course. "These affluents," says
Mardigny, "hurl into the bed of the Ardeche enormous blocks of rock,
which this river, in its turn bears onwards, and grinds down, at high water,
so that its current rolls only gravel at its confluence with the Rhone."
[Footnote: At Rinkenberg, on the right bank of the Vorder Rhein, in the
flood of 1868, a block of stone computed to weigh nearly 9,000 cwt. was
carried bodily forwards, not rolled, by a torrent, a distance of three-quarter
of a mile.—Coaz, die Hochwasser im 1868, p. 54.
Memoire sur les Inondations des Rivieres de l'Ardeche, p. 16. "The
terrific roar, the thunder of the raging torrents proceeds principally from the
stones which are rolled along in the bed of the stream. This movement is
attended with such powerful attrition that, in the Southern Alps, the
atmosphere of valleys where the limestone contains bitumen, has, at the
time of floods, the marked bituminous smell produced by rubbing pieces of
such limestone together."—Wessely, Die Oesterreichischen Alpenlander, i.,
p. 113.] Duponchel makes the following remarkable statement: "The river
Herault rises in a granitic region, but soon reaches calcareous formations,
which it traverses for more than sixty kilometres, rolling through deep and
precipitous ravines, into which the torrents are constantly discharging
enormous masses of pebbles belonging to the hardest rocks of the Jurassian
period. These debris, continually renewed, compose, even below the exit of
the gorge where the river enters into a regular channel cut in a tertiary
deposit, broad beaches, prodigious accumulations of rolled pebbles,
extending several kilometres down the stream, but they diminish in size and
weight so rapidly that above the mouth of the river, which is at a distance of
thirty or thirty-five kilometres from the gorge, every trace of calcareous
matter has disappeared from the sands of the bottom, which are exclusively
silicious." [Footnote: Avant-projet pour la creation d'un sol fertile, p. 20.]
Page 351
Similar effects of the rapid flow of water and the concussion of stones
against each other in river-beds may be observed in almost every Alpine
gorge which serves as the channel of a swift stream. The tremendous cleft
through which the well-known Via Mala is carried receives, every year,
from its own crumbling walls and from the Hinter Rhein and its mild
tributaries, enormous quantities of rock, in blocks and boulders. In fact, the
masses hurled into it in a single flood like those of 1868 would probably fill
it up, at its narrow points, to the level of the road 400 feet above its bottom,
were not the stones crushed and carried off by the force of the current. Yet
below the outlet at Thusis only small rounded boulders, pebbles, and gravel,
not rock, are found in the bed of the river. The Swiss glaciers bring down
thousands of cubic yards of hard rock every season. Where the glacier ends
in a plain or wide valley, the rocks are accumulated in a terminal moraine,
but in numerous instances the water which pours from the ice-river has
forces enough to carry down to larger streams the masses delivered by the
glacier, and there they, with other stones washed out from the earth by the
current, are ground down, so that few of the affluents of the Swiss lakes
deliver into them anything but fine sand and slime. Great rivers carry no
boulders to the sea, and, in fact, receive none from their tributaries.
Lombardini found, twenty years ago, that the mineral matter brought down
to the Po by its tributaries was, in general, comminuted to about the same
degree of fineness as the sands of its bed at their points of discharge. In the
case of the Trebbia, which rises high in the Apennines and empties into the
Po at Piacenza, it was otherwise, that river rolling pebbles and coarse gravel
into the channel of the principal stream. The banks of the other affluents—
excepting some of those which discharge their waters into the great lakes—
then either retained their woods, or had been so long clear of them that the
torrents had removed most of the disintegrated and loose rock in their upper
basins. The valley of the Trebbia had been recently cleared, and all the
forces which tend to the degradation and transportation of rock were in full
against each other in river-beds may be observed in almost every Alpine
gorge which serves as the channel of a swift stream. The tremendous cleft
through which the well-known Via Mala is carried receives, every year,
from its own crumbling walls and from the Hinter Rhein and its mild
tributaries, enormous quantities of rock, in blocks and boulders. In fact, the
masses hurled into it in a single flood like those of 1868 would probably fill
it up, at its narrow points, to the level of the road 400 feet above its bottom,
were not the stones crushed and carried off by the force of the current. Yet
below the outlet at Thusis only small rounded boulders, pebbles, and gravel,
not rock, are found in the bed of the river. The Swiss glaciers bring down
thousands of cubic yards of hard rock every season. Where the glacier ends
in a plain or wide valley, the rocks are accumulated in a terminal moraine,
but in numerous instances the water which pours from the ice-river has
forces enough to carry down to larger streams the masses delivered by the
glacier, and there they, with other stones washed out from the earth by the
current, are ground down, so that few of the affluents of the Swiss lakes
deliver into them anything but fine sand and slime. Great rivers carry no
boulders to the sea, and, in fact, receive none from their tributaries.
Lombardini found, twenty years ago, that the mineral matter brought down
to the Po by its tributaries was, in general, comminuted to about the same
degree of fineness as the sands of its bed at their points of discharge. In the
case of the Trebbia, which rises high in the Apennines and empties into the
Po at Piacenza, it was otherwise, that river rolling pebbles and coarse gravel
into the channel of the principal stream. The banks of the other affluents—
excepting some of those which discharge their waters into the great lakes—
then either retained their woods, or had been so long clear of them that the
torrents had removed most of the disintegrated and loose rock in their upper
basins. The valley of the Trebbia had been recently cleared, and all the
forces which tend to the degradation and transportation of rock were in full
Page 352
activity. [Footnote: Since the date of Lombardini's observations, many
Alpine valleys have been stripped of their woods. It would be interesting to
know whether any sensible change has been produced in the character or
quantity of the matter transported by the rivers to the Po.—Notice sur les
Rivieres de la Lombardie, Annales des Ponts et Chaussees, 1847, 1er
semestre, p. 131.]
Transporting Power of Water.
But the geographical effects of the action of torrents are not confined to
erosion of earth and comminution of rock; for they and the rivers to which
they contribute transport the debris of the mountains to lower levels and
spread them out over the dry land and the bed of the sea, thus forming
alluvial deposits, sometimes of a beneficial, sometimes of an injurious,
character, and of vast extent. [Footnote: Lorentz, in an official report quoted
by Marchand, says: "The felling of the woods produces torrents which
cover the cultivated soil with pebbles and fragments of rock, and they do
not confine their ravages to the vicinity of the mountains, but extend them
into the fertile fields of Provence and other departments, to the distance of
forty or fifty leagues."—Entwaldung der Gebirge, p. 17.]
A mountain rivulet swollen by rain or melted snow, when it escapes from
its usual channel and floods the adjacent fields, naturally deposits pebbles
and gravel upon them; but even at low water, if its course is long enough for
its grinding action to have full scope, it transports the solid material with
which it is charged to some larger stream, and there lets it fall in a state of
minute division, and at last the spoil of the mountain is used to raise the
level of the plains or carried down to the sea.
An instance that fell under my own observation, in 1857, will serve to
show something of the eroding and transporting power of streams which, in
Alpine valleys have been stripped of their woods. It would be interesting to
know whether any sensible change has been produced in the character or
quantity of the matter transported by the rivers to the Po.—Notice sur les
Rivieres de la Lombardie, Annales des Ponts et Chaussees, 1847, 1er
semestre, p. 131.]
Transporting Power of Water.
But the geographical effects of the action of torrents are not confined to
erosion of earth and comminution of rock; for they and the rivers to which
they contribute transport the debris of the mountains to lower levels and
spread them out over the dry land and the bed of the sea, thus forming
alluvial deposits, sometimes of a beneficial, sometimes of an injurious,
character, and of vast extent. [Footnote: Lorentz, in an official report quoted
by Marchand, says: "The felling of the woods produces torrents which
cover the cultivated soil with pebbles and fragments of rock, and they do
not confine their ravages to the vicinity of the mountains, but extend them
into the fertile fields of Provence and other departments, to the distance of
forty or fifty leagues."—Entwaldung der Gebirge, p. 17.]
A mountain rivulet swollen by rain or melted snow, when it escapes from
its usual channel and floods the adjacent fields, naturally deposits pebbles
and gravel upon them; but even at low water, if its course is long enough for
its grinding action to have full scope, it transports the solid material with
which it is charged to some larger stream, and there lets it fall in a state of
minute division, and at last the spoil of the mountain is used to raise the
level of the plains or carried down to the sea.
An instance that fell under my own observation, in 1857, will serve to
show something of the eroding and transporting power of streams which, in
Page 353
these respects, fall incalculably below the torrents of the Alps. In a flood of
the Ottaquechee, a small river which flows through Woodstock, Vermont, a
mill-dam on that stream burst, and the sediment with which the pond was
filled, estimated after careful measurement at 13,000 cubic yards, was
carried down by the current. Between this dam and the slackwater of
another, four miles below, the bed of the stream, which is composed of
pebbles interspersed in a few places with larger stones, is about sixty-five
feet wide, though, at low water, the breadth of the current is considerably
less. The sand and fine gravel were smoothly and evenly distributed over
the bed to a width of fifty-five or sixty feet, and, for a distance of about two
miles, except at two or three intervening rapids, filled up all the interstices
between the stones, covering them to the depth of nine or ten inches, so as
to present a regularly formed concave channel, lined with sand, and
reducing the depth of water, in some places, from five or six feet to fifteen
or eighteen inches. Observing this deposit after the river had subsided and
become so clear that the bottom could be seen, I supposed that the next
flood would produce an extraordinary erosion of the banks and some
permanent changes in the channel of the stream, in consequence of the
elevation of the bed and the filling up of the spaces between the stones
through which formerly much water had flowed; but no such result
followed. The spring freshet of the next year entirely washed out the sand
its predecessor had left, deposited some of it in ponds and still-water
reaches below, carried the residue beyond the reach of observation, and left
the bed of the river almost precisely in its former condition, though, of
course, with the displacement of the pebbles which every flood produces in
the channels of such streams. The pond, though often previously discharged
by the breakage of the dam, had then been undisturbed for about twenty-
five years, and its contents consisted almost entirely of sand, the rapidity of
the current in floods being such that it would let fall little lighter sediment,
even above an obstruction like a dam. The quantity I have mentioned
the Ottaquechee, a small river which flows through Woodstock, Vermont, a
mill-dam on that stream burst, and the sediment with which the pond was
filled, estimated after careful measurement at 13,000 cubic yards, was
carried down by the current. Between this dam and the slackwater of
another, four miles below, the bed of the stream, which is composed of
pebbles interspersed in a few places with larger stones, is about sixty-five
feet wide, though, at low water, the breadth of the current is considerably
less. The sand and fine gravel were smoothly and evenly distributed over
the bed to a width of fifty-five or sixty feet, and, for a distance of about two
miles, except at two or three intervening rapids, filled up all the interstices
between the stones, covering them to the depth of nine or ten inches, so as
to present a regularly formed concave channel, lined with sand, and
reducing the depth of water, in some places, from five or six feet to fifteen
or eighteen inches. Observing this deposit after the river had subsided and
become so clear that the bottom could be seen, I supposed that the next
flood would produce an extraordinary erosion of the banks and some
permanent changes in the channel of the stream, in consequence of the
elevation of the bed and the filling up of the spaces between the stones
through which formerly much water had flowed; but no such result
followed. The spring freshet of the next year entirely washed out the sand
its predecessor had left, deposited some of it in ponds and still-water
reaches below, carried the residue beyond the reach of observation, and left
the bed of the river almost precisely in its former condition, though, of
course, with the displacement of the pebbles which every flood produces in
the channels of such streams. The pond, though often previously discharged
by the breakage of the dam, had then been undisturbed for about twenty-
five years, and its contents consisted almost entirely of sand, the rapidity of
the current in floods being such that it would let fall little lighter sediment,
even above an obstruction like a dam. The quantity I have mentioned
Page 354
evidently bears a very inconsiderable proportion to the total erosion of the
stream during that period, because the wash of the banks consists chiefly of
fine earth rather than of sand, and after the pond was once filled, or nearly
so, even this material could no longer be deposited in it. The fact of the
complete removal of the deposit I have described between the two dams in
a single freshet, shows that, in spite of considerable obstruction from
roughness of bed, large quantities of sand may be taken up and carried off
by streams of no great rapidity of inclination; for the whole descent of the
bed of the river between the two dams—a distance of four miles—is but
sixty feet, or fifteen feet to the mile. [Footnote: In a sheet-iron siphon, 1,000
feet long, with a diameter of four inches, having the entrance 18 feet, the
orifice of discharge 40 feet below the summit of the curve, employed in
draining a mine In California, the force of the current was such as to carry
through the tube great quantities of sand and coarse gravel, some of the
grains of which were as large as an English walnut. —Raymond, Mining
Statistics, 1870, p. 602.] The facts which I have adduced may aid us in
forming an idea of the origin and mode of transportation of the prodigious
deposits at the mouth of great rivers like the Mississippi, the Nile, the
Ganges, and the Hoang-Ho, the delta of which last river, composed entirely
of river sediment, has a superficial extent of not less than 96,500 square
miles. But we shall obtain a clearer conception of the character of this
important geographical process by measuring, more in detail, the mass of
earth and rock which a well—known river and its tributaries have washed
from the mountains and transported to the plains or the sea, within the
historic period.
The Po and its Deposits.
The current of the River Po, for a considerable distance after its volume
of water is otherwise sufficient for continuous navigation, is too rapid for
stream during that period, because the wash of the banks consists chiefly of
fine earth rather than of sand, and after the pond was once filled, or nearly
so, even this material could no longer be deposited in it. The fact of the
complete removal of the deposit I have described between the two dams in
a single freshet, shows that, in spite of considerable obstruction from
roughness of bed, large quantities of sand may be taken up and carried off
by streams of no great rapidity of inclination; for the whole descent of the
bed of the river between the two dams—a distance of four miles—is but
sixty feet, or fifteen feet to the mile. [Footnote: In a sheet-iron siphon, 1,000
feet long, with a diameter of four inches, having the entrance 18 feet, the
orifice of discharge 40 feet below the summit of the curve, employed in
draining a mine In California, the force of the current was such as to carry
through the tube great quantities of sand and coarse gravel, some of the
grains of which were as large as an English walnut. —Raymond, Mining
Statistics, 1870, p. 602.] The facts which I have adduced may aid us in
forming an idea of the origin and mode of transportation of the prodigious
deposits at the mouth of great rivers like the Mississippi, the Nile, the
Ganges, and the Hoang-Ho, the delta of which last river, composed entirely
of river sediment, has a superficial extent of not less than 96,500 square
miles. But we shall obtain a clearer conception of the character of this
important geographical process by measuring, more in detail, the mass of
earth and rock which a well—known river and its tributaries have washed
from the mountains and transported to the plains or the sea, within the
historic period.
The Po and its Deposits.
The current of the River Po, for a considerable distance after its volume
of water is otherwise sufficient for continuous navigation, is too rapid for
Page 355
that purpose until near Cremona, where its velocity becomes too much
reduced to transport great quantities of mineral matter, except in a state of
minute division. Its southern affluents bring down from the Apennines a
large quantity of fine earth from various geological formations, while its
Alpine tributaries west of the Ticino are charged chiefly with rock ground
down to sand or gravel. The bed of the river has been somewhat elevated by
the deposits in its channel, though not by any means above the level of the
adjacent plains as has been so often represented. The dikes, which confine
the current at high water, at the same time augment its velocity and compel
it to carry most of its sediment to the Adriatic. It has, therefore, raised
neither its own channel nor its alluvial shores, as it would have done if it
had remained unconfined. But, as the surface of the water in floods is above
the general level of the plains through which it flows, the Po can, at that
period, receive no contributions of earth from the washing of the fields of
Lombardy, and there is no doubt that a large proportion of the sediment it
now deposits at its mouth descended from the Alps in the form of rock,
though reduced by the grinding action of the waters, in its passage seaward,
to the condition of fine sand, and often of silt.
We know little of the history of the Po, or of the geography of the coast
near the point where it enters the Adriatic, at any period more than twenty
centuries before our own. Still less can we say how much of the plains of
Lombardy had been formed by its action, combined with other causes,
before man accelerated its levelling operations by felling the first woods on
the mountains whence its waters are derived. But we know that since the
Roman conquest of Northern Italy, its deposits have amounted to a quantity
which, if recemented into rock, recombined into gravel, common earth, and
vegetable mould, and restored to the situations where eruption or upheaval
originally placed or vegetation deposited it, would fill up hundreds of deep
ravines in the Alps and Apennines, change the plan and profile of their
chains, and give their southern and northern faces respectively a
reduced to transport great quantities of mineral matter, except in a state of
minute division. Its southern affluents bring down from the Apennines a
large quantity of fine earth from various geological formations, while its
Alpine tributaries west of the Ticino are charged chiefly with rock ground
down to sand or gravel. The bed of the river has been somewhat elevated by
the deposits in its channel, though not by any means above the level of the
adjacent plains as has been so often represented. The dikes, which confine
the current at high water, at the same time augment its velocity and compel
it to carry most of its sediment to the Adriatic. It has, therefore, raised
neither its own channel nor its alluvial shores, as it would have done if it
had remained unconfined. But, as the surface of the water in floods is above
the general level of the plains through which it flows, the Po can, at that
period, receive no contributions of earth from the washing of the fields of
Lombardy, and there is no doubt that a large proportion of the sediment it
now deposits at its mouth descended from the Alps in the form of rock,
though reduced by the grinding action of the waters, in its passage seaward,
to the condition of fine sand, and often of silt.
We know little of the history of the Po, or of the geography of the coast
near the point where it enters the Adriatic, at any period more than twenty
centuries before our own. Still less can we say how much of the plains of
Lombardy had been formed by its action, combined with other causes,
before man accelerated its levelling operations by felling the first woods on
the mountains whence its waters are derived. But we know that since the
Roman conquest of Northern Italy, its deposits have amounted to a quantity
which, if recemented into rock, recombined into gravel, common earth, and
vegetable mould, and restored to the situations where eruption or upheaval
originally placed or vegetation deposited it, would fill up hundreds of deep
ravines in the Alps and Apennines, change the plan and profile of their
chains, and give their southern and northern faces respectively a
Page 356
geographical aspect very different from that they now present. Ravenna,
forty miles south of the principal mouth of the Po, was built like Venice, in
a lagoon, and the Adriatic still washed its walls at the commencement of the
Christian era. The mud of the Po has filled up the lagoon, and Ravenna is
now four miles from the sea. The town of Adria, which lies between the Po
and the Adige, at the distance of some four or five miles from each, was
once a harbor famous enough to have given its name to the Adriatic Sea,
and it was still accessible to large vessels, if not by the open sea at least by
lagoons, in the time of Augustus. The combined action of the two rivers has
so advanced the coast-line that Adria is now more than fourteen miles
inland, and, in other places, the deposits made within the same period by
these and other neighboring streams have a width of twenty miles.
What proportion of the earth with which they are charged these rivers
have borne out into deep water, during the last two thousand years, we do
not know, but as they still transport enormous quantities, as the North
Adriatic appears to have shoaled rapidly, and as long islands, composed in
great part of fluviatile deposits, have formed opposite their mouths, it must
evidently have been very great. The floods of the Po occur but once, or
sometimes twice, in a year. [Footnote: In the earlier medieval centuries,
when the declivities of the mountains still retained a much larger proportion
of their woods, the moderate annual floods of the Po were occasioned by
the melting of the snows on the lower slopes, and, according to a passage of
Tasso quoted by Castellani (Dell' Influenza delle Selve, i., p. 58, note), they
took place in May. The usually more violent inundations of later ages are
due to rains, the waters of which are no longer retained by a forest-soil, but
conveyed at once to the rivers—and they occur almost uniformly in the
autumn or late summer. Castellani, on the page just quoted, says that even
so late as about 1780, the Po required a heavy rain of a week to overflow its
banks, but that forty years later it was sometimes raised to full flood in a
single day. Pliny says: "The Po, which is inferior to no river in swiftness of
forty miles south of the principal mouth of the Po, was built like Venice, in
a lagoon, and the Adriatic still washed its walls at the commencement of the
Christian era. The mud of the Po has filled up the lagoon, and Ravenna is
now four miles from the sea. The town of Adria, which lies between the Po
and the Adige, at the distance of some four or five miles from each, was
once a harbor famous enough to have given its name to the Adriatic Sea,
and it was still accessible to large vessels, if not by the open sea at least by
lagoons, in the time of Augustus. The combined action of the two rivers has
so advanced the coast-line that Adria is now more than fourteen miles
inland, and, in other places, the deposits made within the same period by
these and other neighboring streams have a width of twenty miles.
What proportion of the earth with which they are charged these rivers
have borne out into deep water, during the last two thousand years, we do
not know, but as they still transport enormous quantities, as the North
Adriatic appears to have shoaled rapidly, and as long islands, composed in
great part of fluviatile deposits, have formed opposite their mouths, it must
evidently have been very great. The floods of the Po occur but once, or
sometimes twice, in a year. [Footnote: In the earlier medieval centuries,
when the declivities of the mountains still retained a much larger proportion
of their woods, the moderate annual floods of the Po were occasioned by
the melting of the snows on the lower slopes, and, according to a passage of
Tasso quoted by Castellani (Dell' Influenza delle Selve, i., p. 58, note), they
took place in May. The usually more violent inundations of later ages are
due to rains, the waters of which are no longer retained by a forest-soil, but
conveyed at once to the rivers—and they occur almost uniformly in the
autumn or late summer. Castellani, on the page just quoted, says that even
so late as about 1780, the Po required a heavy rain of a week to overflow its
banks, but that forty years later it was sometimes raised to full flood in a
single day. Pliny says: "The Po, which is inferior to no river in swiftness of
Page 357
current, is in flood about the rising of the dog-star, the snow then melting,
and though so rapid in flow, it washes nothing from the soil, but leaves it
increased in fertility."—Natural History, Book iii, 20.
The first terrible inundation of the Po in 1872 took place in May, and
appears to have been occasioned by heavy rains on the southern flank of the
Alps, and to have received little accession from snow. The snow on the
higher Alps does not usually thaw so as to occasion floods before August,
and often considerably later. The more destructive flood of October, 1872,
was caused both by thaws in the high mountains and by an extraordinary
fall of rain. See River Embankments; post. Pliny's remark as to enrichment
of the soil by the floods appear to be verified in the case of that of October,
1872, for it is found that the water has left very extensively a thick deposit
of slime on the fields. See a list of the historically known great inundations
of the Po by the engineer Zuccholli in Torelli, Progetto di Legge per la
Vendita di Beni incolti. Roma, 1873.]
At other times, its waters are comparatively limpid and seem to hold no
great amount of mud or fine sand in mechanical suspension; but at high
water it contains a large proportion of solid matter, and, according to
Lombardini, it annually transports to the shores of the Adriatic not less than
42,760,000 cubic metres, or very nearly 55,000,000 cubic yards, which
carries the coast-line out into the sea at the rate of more than 200 feet in a
year. [Footnote: This change of coast-line cannot be ascribed to upheaval,
for a comparison of the level of old buildings—as, for instance, the church
of San Vitale and the tomb of Theodoric at Ravenna—with that of the sea,
tends to prove a depression rather than an elevation of their foundations. A
computation by a different method makes the deposits at the mouth of the
Po 2,123,000 metres less; but as both of them omit the gravel and silt
carried down at ordinary and low water, we are safe in assuming the larger
quantity.] The depth of the annual deposit is stated at eighteen centimetres,
and though so rapid in flow, it washes nothing from the soil, but leaves it
increased in fertility."—Natural History, Book iii, 20.
The first terrible inundation of the Po in 1872 took place in May, and
appears to have been occasioned by heavy rains on the southern flank of the
Alps, and to have received little accession from snow. The snow on the
higher Alps does not usually thaw so as to occasion floods before August,
and often considerably later. The more destructive flood of October, 1872,
was caused both by thaws in the high mountains and by an extraordinary
fall of rain. See River Embankments; post. Pliny's remark as to enrichment
of the soil by the floods appear to be verified in the case of that of October,
1872, for it is found that the water has left very extensively a thick deposit
of slime on the fields. See a list of the historically known great inundations
of the Po by the engineer Zuccholli in Torelli, Progetto di Legge per la
Vendita di Beni incolti. Roma, 1873.]
At other times, its waters are comparatively limpid and seem to hold no
great amount of mud or fine sand in mechanical suspension; but at high
water it contains a large proportion of solid matter, and, according to
Lombardini, it annually transports to the shores of the Adriatic not less than
42,760,000 cubic metres, or very nearly 55,000,000 cubic yards, which
carries the coast-line out into the sea at the rate of more than 200 feet in a
year. [Footnote: This change of coast-line cannot be ascribed to upheaval,
for a comparison of the level of old buildings—as, for instance, the church
of San Vitale and the tomb of Theodoric at Ravenna—with that of the sea,
tends to prove a depression rather than an elevation of their foundations. A
computation by a different method makes the deposits at the mouth of the
Po 2,123,000 metres less; but as both of them omit the gravel and silt
carried down at ordinary and low water, we are safe in assuming the larger
quantity.] The depth of the annual deposit is stated at eighteen centimetres,
Page 358
or rather more than seven inches, and it would cover an area of not much
less than ninety square miles with a layer of that thickness. The Adige, also,
brings every year to the Adriatic many million cubic yards of Alpine
detritus, and the contributions of the Brenta from the same source are far
from inconsiderable. The Adriatic, however, receives but a small proportion
of the soil and rock washed away from the Italian slope of the Alps and the
northern declivity of the Apennines by torrents. Nearly the whole of the
debris thus removed from the southern face of the Alps between Monte
Rosa and the sources of the Adda—a length of watershed [Footnote: Sir
John F. W. Herschel (Physical Geography, 137, and elsewhere) spells this
word water-sched, because he considers it a translation, or rather an
adoption, of the German "Wasser-scheide, separation of the waters, not
water-SHED the slope DOWN WHICH the waters run." As a point of
historical etymology, it is probable that the word in question was suggested
to those who first used it by the German Wasserscheide; but the spelling
WATER-SCHED, proposed by Herschel, is objectionable, both because
SCH is a combination of letters wholly unknown to modern English
orthography, and properly representing no sound recognized in English
orthoepy, and for the still better reason that WATER-SHED, in the sense of
DIVISION-OF-THE-WATERS, has a legitimate English etymology. The
Anglo-Saxon sceadan meant both to separate or divide, and to shade or
shelter. It is the root of the English verbs TO SHED and TO SHADE, and in
the former meaning is the A. S. equivalent of the German verb scheiden.
SHED in Old English had the meaning to SEPARATE or DISTINGUISH. It
is so used in the Owl and the Nightingale, v. 107. Palsgrave
(Lesclarcissement, etc., p. 717) defines I SHEDE, I departe thinges asonder;
and the word still means TO DIVIDE in several English local dialects.
Hence, watershed, the division or separation of the waters, is good English
both in etymology and in spelling.] not less than one hundred and fifty
miles—is arrested by the still waters of the Lakes Maggiore and Como, and
less than ninety square miles with a layer of that thickness. The Adige, also,
brings every year to the Adriatic many million cubic yards of Alpine
detritus, and the contributions of the Brenta from the same source are far
from inconsiderable. The Adriatic, however, receives but a small proportion
of the soil and rock washed away from the Italian slope of the Alps and the
northern declivity of the Apennines by torrents. Nearly the whole of the
debris thus removed from the southern face of the Alps between Monte
Rosa and the sources of the Adda—a length of watershed [Footnote: Sir
John F. W. Herschel (Physical Geography, 137, and elsewhere) spells this
word water-sched, because he considers it a translation, or rather an
adoption, of the German "Wasser-scheide, separation of the waters, not
water-SHED the slope DOWN WHICH the waters run." As a point of
historical etymology, it is probable that the word in question was suggested
to those who first used it by the German Wasserscheide; but the spelling
WATER-SCHED, proposed by Herschel, is objectionable, both because
SCH is a combination of letters wholly unknown to modern English
orthography, and properly representing no sound recognized in English
orthoepy, and for the still better reason that WATER-SHED, in the sense of
DIVISION-OF-THE-WATERS, has a legitimate English etymology. The
Anglo-Saxon sceadan meant both to separate or divide, and to shade or
shelter. It is the root of the English verbs TO SHED and TO SHADE, and in
the former meaning is the A. S. equivalent of the German verb scheiden.
SHED in Old English had the meaning to SEPARATE or DISTINGUISH. It
is so used in the Owl and the Nightingale, v. 107. Palsgrave
(Lesclarcissement, etc., p. 717) defines I SHEDE, I departe thinges asonder;
and the word still means TO DIVIDE in several English local dialects.
Hence, watershed, the division or separation of the waters, is good English
both in etymology and in spelling.] not less than one hundred and fifty
miles—is arrested by the still waters of the Lakes Maggiore and Como, and
Page 359
some smaller lacustrine reservoirs, and never reaches the sea. The Po is not
continuously embanked except for the lower half of its course. Above
Cremona, therefore, it spreads and deposits sediment over a wide surface,
and the water withdrawn from it for irrigation at lower points, as well as its
inundations in the occasional ruptures of its banks, carry over the adjacent
soil a large amount of slime. [Footnote: The quantity of sediment deposited
by the Po on the plains which border it, before the construction of the
continuous dikes and in the floods which occasionally burst through them,
is vast, and the consequent elevation of those plains is very considerable. I
do not know that this latter point has been made a subject of special
investigation, but vineyards, with the vines still attached to the elms which
supported them, have been found two or three yards below the present
surface at various points on the plains of Lombardy.]
If to the estimated annual deposits of the Po at its mouth, we add the
earth and sand transported to the sea by the Adige, the Brenta, and other
less important streams, the prodigious mass of detritus swept into Lago
Maggioro by the Tosa, the Maggia, and the Ticino, into the lake of Como by
the Maira and the Adda, into the lakes of Garda, Lugano, Iseo, and Idro, by
their affluents, [Footnote: The Po receives about four-tenths of its waters
from these lakes. See Lombardini, Dei cangiamenti nella condizione del Po,
p. 29. All the sediment carried into the lakes by their tributaries is deposited
in them, and the water which flows out of them is perfectly limpid. From
their proximity to the Alps and the number of torrents which empty into
them, they no doubt receive vastly more transported matter than is
contributed to the Po by the six-tenths of its waters received from other
sources.] and the yet vaster heaps of pebbles, gravel, and earth permanently
deposited by the torrents near their points of eruption from mountain
gorges, or spread over the wide plains at lower levels, we may safely
assume that we have an aggregate of not less than ten times the quantity
carried to the Adriatic by the Po, or 550,000,000 cubic yards of solid matter,
continuously embanked except for the lower half of its course. Above
Cremona, therefore, it spreads and deposits sediment over a wide surface,
and the water withdrawn from it for irrigation at lower points, as well as its
inundations in the occasional ruptures of its banks, carry over the adjacent
soil a large amount of slime. [Footnote: The quantity of sediment deposited
by the Po on the plains which border it, before the construction of the
continuous dikes and in the floods which occasionally burst through them,
is vast, and the consequent elevation of those plains is very considerable. I
do not know that this latter point has been made a subject of special
investigation, but vineyards, with the vines still attached to the elms which
supported them, have been found two or three yards below the present
surface at various points on the plains of Lombardy.]
If to the estimated annual deposits of the Po at its mouth, we add the
earth and sand transported to the sea by the Adige, the Brenta, and other
less important streams, the prodigious mass of detritus swept into Lago
Maggioro by the Tosa, the Maggia, and the Ticino, into the lake of Como by
the Maira and the Adda, into the lakes of Garda, Lugano, Iseo, and Idro, by
their affluents, [Footnote: The Po receives about four-tenths of its waters
from these lakes. See Lombardini, Dei cangiamenti nella condizione del Po,
p. 29. All the sediment carried into the lakes by their tributaries is deposited
in them, and the water which flows out of them is perfectly limpid. From
their proximity to the Alps and the number of torrents which empty into
them, they no doubt receive vastly more transported matter than is
contributed to the Po by the six-tenths of its waters received from other
sources.] and the yet vaster heaps of pebbles, gravel, and earth permanently
deposited by the torrents near their points of eruption from mountain
gorges, or spread over the wide plains at lower levels, we may safely
assume that we have an aggregate of not less than ten times the quantity
carried to the Adriatic by the Po, or 550,000,000 cubic yards of solid matter,
Page 360
abstracted every year from the Italian Alps and the Apennines, and removed
out of their domain by the force of running water. [Footnote: Mengotti
estimated the mass of solid matter annually "united to the waters of the Po"
at 822,000,000 cubic metres, or nearly twenty times as much as, according
to Lombardini, that river delivers into the Adriatic. Castellani supposes the
computation of Mengotti to fall much below the truth, and there can be no
doubt that a vastly larger quantity of earth and gravel is washed down from
the Alps and the Apennines than is carried to the sea.—Castellani, Dell
Immediata Influenza delle Salce sul corso delle Acqua, i., pp. 42,43.
I have contented myself with assuming less than one-half of Mengotti's
estimate.] The present rate of deposit at the mouth of the Po has continued
since the year 1600, the previous advance of the coast, after the year 1200,
having been only one-third as rapid. The great increase of erosion and
transport is ascribed by Lombardini chiefly to the destruction of the forests
in the basin of that river and the valleys of its tributaries, since the
beginning of the seventeenth century. [Footnote: Baumgarten, An. des Ponts
et Chaussees, 1847, 1er semestre, p. 175.] We have no data to show the rate
of deposit in any given century before the year 1200, and it doubtless varied
according to the progress of population and the consequent extension of
clearing and cultivation. The transporting power of torrents is greatest soon
after their formation, because at that time their points of delivery are lower,
and, of course, their general slope and velocity more rapid, than after years
of erosion above, and deposit below, have depressed the beds of their
mountain valleys, and elevated the channels of their lower course. Their
eroding action also is most powerful at the same period, both because their
mechanical force is then greatest, and because the loose earth and stones of
freshly cleared forest-ground are most easily removed. Many of the Alpine
valleys west of the Ticino—that of the Dora Baltea, for instance—were
nearly stripped of their forests in the days of the Roman Empire, others in
the Middle Ages, and, of course, there must have been, at different periods
out of their domain by the force of running water. [Footnote: Mengotti
estimated the mass of solid matter annually "united to the waters of the Po"
at 822,000,000 cubic metres, or nearly twenty times as much as, according
to Lombardini, that river delivers into the Adriatic. Castellani supposes the
computation of Mengotti to fall much below the truth, and there can be no
doubt that a vastly larger quantity of earth and gravel is washed down from
the Alps and the Apennines than is carried to the sea.—Castellani, Dell
Immediata Influenza delle Salce sul corso delle Acqua, i., pp. 42,43.
I have contented myself with assuming less than one-half of Mengotti's
estimate.] The present rate of deposit at the mouth of the Po has continued
since the year 1600, the previous advance of the coast, after the year 1200,
having been only one-third as rapid. The great increase of erosion and
transport is ascribed by Lombardini chiefly to the destruction of the forests
in the basin of that river and the valleys of its tributaries, since the
beginning of the seventeenth century. [Footnote: Baumgarten, An. des Ponts
et Chaussees, 1847, 1er semestre, p. 175.] We have no data to show the rate
of deposit in any given century before the year 1200, and it doubtless varied
according to the progress of population and the consequent extension of
clearing and cultivation. The transporting power of torrents is greatest soon
after their formation, because at that time their points of delivery are lower,
and, of course, their general slope and velocity more rapid, than after years
of erosion above, and deposit below, have depressed the beds of their
mountain valleys, and elevated the channels of their lower course. Their
eroding action also is most powerful at the same period, both because their
mechanical force is then greatest, and because the loose earth and stones of
freshly cleared forest-ground are most easily removed. Many of the Alpine
valleys west of the Ticino—that of the Dora Baltea, for instance—were
nearly stripped of their forests in the days of the Roman Empire, others in
the Middle Ages, and, of course, there must have been, at different periods
Page 361
before the year 1200, epochs when the erosion and transportation of solid
matter from the Alps and the Apennines were at least as great as since the
year 1600.
Upon the whole, we shall not greatly err if we assume that, for a period
of not less than two thousand years, the walls of the basin of the Po—the
Italian slope of the Alps, and the northern and north-eastern declivities of
the Apennines—have annually sent down into the lakes, the plains, and the
Adriatic, not less than 375,000,000 cubic yards of earth and disintegrated
rock. We have, then, an aggregate of 750,000,000,000 cubic yards of such
material, which, allowing to the mountain surface in question an area of
50,000,000,000 square yards, would cover the whole to the depth of fifteen
yards. [Footnote: The total superficies of the basin of the Po, down to Ponte
Lagoscuro [Ferrara]—a point where it has received all its affluents—is
6,938,200 hectares, that is, 4,105,600 in mountain lands, 2,832,600 in plain
lands.—Dumont, Travaux Publics, etc., p. 272. These latter two quantities
are equal respectively to 10,145,348, and 6,999,638 acres, or 15,852 and
10,937 square miles.] There are very large portions of this area, where, as
we know from ancient remains—roads, bridges, and the like—from other
direct testimony, and from geological considerations, very little degradation
has taken place within twenty centuries, and hence the quantity to be
assigned to localities where the destructive causes have been most active is
increased in proportion.
If this vast mass of pulverized rock and earth were restored to the
localities from which it was derived, it certainly would not obliterate
valleys and gorges hollowed out by great geological causes, but it would
reduce the length and diminish the depth of ravines of later formation,
modify the inclination of their walls, reclothe with earth many bare
mountain ridges, essentially change the line of junction between plain and
mountain, and carry back a long reach of the Adriatic coast many miles to
matter from the Alps and the Apennines were at least as great as since the
year 1600.
Upon the whole, we shall not greatly err if we assume that, for a period
of not less than two thousand years, the walls of the basin of the Po—the
Italian slope of the Alps, and the northern and north-eastern declivities of
the Apennines—have annually sent down into the lakes, the plains, and the
Adriatic, not less than 375,000,000 cubic yards of earth and disintegrated
rock. We have, then, an aggregate of 750,000,000,000 cubic yards of such
material, which, allowing to the mountain surface in question an area of
50,000,000,000 square yards, would cover the whole to the depth of fifteen
yards. [Footnote: The total superficies of the basin of the Po, down to Ponte
Lagoscuro [Ferrara]—a point where it has received all its affluents—is
6,938,200 hectares, that is, 4,105,600 in mountain lands, 2,832,600 in plain
lands.—Dumont, Travaux Publics, etc., p. 272. These latter two quantities
are equal respectively to 10,145,348, and 6,999,638 acres, or 15,852 and
10,937 square miles.] There are very large portions of this area, where, as
we know from ancient remains—roads, bridges, and the like—from other
direct testimony, and from geological considerations, very little degradation
has taken place within twenty centuries, and hence the quantity to be
assigned to localities where the destructive causes have been most active is
increased in proportion.
If this vast mass of pulverized rock and earth were restored to the
localities from which it was derived, it certainly would not obliterate
valleys and gorges hollowed out by great geological causes, but it would
reduce the length and diminish the depth of ravines of later formation,
modify the inclination of their walls, reclothe with earth many bare
mountain ridges, essentially change the line of junction between plain and
mountain, and carry back a long reach of the Adriatic coast many miles to
Page 362
the west. [Footnote: I do not use these quantities as factors the value of
which is precisely ascertained; nor, for the purposes of the present
argument, is quantitative exactness important. I employ numerical
statements simply as a means of aiding the imagination to form a general
and certainly not extravagant idea of the extent of geographical revolutions
which man has done much to accelerate, if not, strictly speaking, to
produce.
There is an old proverb, Dolus latet in generalibus, and Arthur Young in
not the only public economist who has warned his readers against the
deceitfulness of round numbers. I think, on the contrary, that vastly more
error has been produced by the affectation of precision in cases where
precision is impossible.
In all the great operations of terrestrial nature, the elements are so
numerous and so difficult of exact appreciation, that, until the means of
scientific observation and measurement are much more perfected than they
now are, we must content ourselves with general approximations. I say
TERRESTRIAL nature, because in cosmical movements we have fewer
elements to deal with, and may therefore arrive at much more rigorous
proportional accuracy in determination of time and place than we can in
fixing and predicting the quantities and the epochs of variable natural
phenomena on the earth's surface.
Travellers are often misled by local habits in the use of what may be
called representative numbers, where a definite is put for an indefinite
quantity. A Greek, who wished to express the notion of a great but
undetermined number, "myriad, or ten thousand;" a Roman, "six hundred;"
an Oriental, "forty," or, at present, very commonly, "fifteen thousand."
Many a tourist has gravely repeated, as an ascertained fact; the vague
statement of the Arabs and the monks of Mount Sinai, that the ascent from
which is precisely ascertained; nor, for the purposes of the present
argument, is quantitative exactness important. I employ numerical
statements simply as a means of aiding the imagination to form a general
and certainly not extravagant idea of the extent of geographical revolutions
which man has done much to accelerate, if not, strictly speaking, to
produce.
There is an old proverb, Dolus latet in generalibus, and Arthur Young in
not the only public economist who has warned his readers against the
deceitfulness of round numbers. I think, on the contrary, that vastly more
error has been produced by the affectation of precision in cases where
precision is impossible.
In all the great operations of terrestrial nature, the elements are so
numerous and so difficult of exact appreciation, that, until the means of
scientific observation and measurement are much more perfected than they
now are, we must content ourselves with general approximations. I say
TERRESTRIAL nature, because in cosmical movements we have fewer
elements to deal with, and may therefore arrive at much more rigorous
proportional accuracy in determination of time and place than we can in
fixing and predicting the quantities and the epochs of variable natural
phenomena on the earth's surface.
Travellers are often misled by local habits in the use of what may be
called representative numbers, where a definite is put for an indefinite
quantity. A Greek, who wished to express the notion of a great but
undetermined number, "myriad, or ten thousand;" a Roman, "six hundred;"
an Oriental, "forty," or, at present, very commonly, "fifteen thousand."
Many a tourist has gravely repeated, as an ascertained fact; the vague
statement of the Arabs and the monks of Mount Sinai, that the ascent from
Page 363
the convent of St. Catherine to the summit of Gebel Moosa counts "fifteen
thousand" steps, though the difference of level is two thousand feet; and the
"Forty" Thieves, the "forty" martyr-monks of the convent of El Arbain—not
to speak of a similar use of this numeral in more important cases—have
often been understood as expressions of a known number, when in fact they
mean simply MANY. The number "fifteen thousand" has found its way to
Rome, and De Quincey seriously informs us, on the authority of a lady who
had been at much pains to ascertain the EXACT truth, that, including
closets large enough for a bed, the Vatican contains fifteen thousand rooms.
Any one who has observed the vast dimensions of most of the apartments of
that structure will admit that we make a very small allowance of space
when we assign a square rod, sixteen and a half feet square, to each room
upon the average. On an acre, there might be one hundred and sixty such
rooms, including partition walls; and, to contain fifteen thousand of them, a
building must cover more than nine acres, and be ten stories high, or
possess other equivalent dimensions, which, as every traveller knows, many
times exceeds the truth.
The value of a high standard of accuracy in scientific observation can
hardly be overrated; but habits of rigorous exactness will never be formed
by an investigator who allows himself to trust implicitly to the numerical
precision or the results of a few experiments. The wonderful accuracy of
geodetic measurements in modern times is, in general, attained by taking
the mean of a great number of observations at every station, and this final
precision is but the mutual balance and compensation of numerous errors.
The pretended exactness of statistical tables is too often little better than
an imposture; and those founded not on direct estimation by competent
observers, but on the report of persons who have no particular interest in
knowing the truth, but often have a motive for distorting it, are commonly
to be regarded as but vague guesses at the actual fact.]
thousand" steps, though the difference of level is two thousand feet; and the
"Forty" Thieves, the "forty" martyr-monks of the convent of El Arbain—not
to speak of a similar use of this numeral in more important cases—have
often been understood as expressions of a known number, when in fact they
mean simply MANY. The number "fifteen thousand" has found its way to
Rome, and De Quincey seriously informs us, on the authority of a lady who
had been at much pains to ascertain the EXACT truth, that, including
closets large enough for a bed, the Vatican contains fifteen thousand rooms.
Any one who has observed the vast dimensions of most of the apartments of
that structure will admit that we make a very small allowance of space
when we assign a square rod, sixteen and a half feet square, to each room
upon the average. On an acre, there might be one hundred and sixty such
rooms, including partition walls; and, to contain fifteen thousand of them, a
building must cover more than nine acres, and be ten stories high, or
possess other equivalent dimensions, which, as every traveller knows, many
times exceeds the truth.
The value of a high standard of accuracy in scientific observation can
hardly be overrated; but habits of rigorous exactness will never be formed
by an investigator who allows himself to trust implicitly to the numerical
precision or the results of a few experiments. The wonderful accuracy of
geodetic measurements in modern times is, in general, attained by taking
the mean of a great number of observations at every station, and this final
precision is but the mutual balance and compensation of numerous errors.
The pretended exactness of statistical tables is too often little better than
an imposture; and those founded not on direct estimation by competent
observers, but on the report of persons who have no particular interest in
knowing the truth, but often have a motive for distorting it, are commonly
to be regarded as but vague guesses at the actual fact.]
Page 364
It is, indeed, not to be supposed that all the degradation of the mountains
is due to the destruction of the forests—that the flanks of every Alpine
valley in Central Europe below the snow-line were once covered with earth
and green with woods, but there are not many particular cases in which we
can, with certainty, or even with strong probability, affirm the contrary.
Mountain Slides.
Terrible as are the ravages of the torrent and the river-flood, the
destruction of the woods exposes human life and industry to calamities even
more appalling than those which I have yet described. The slide in the
Notch of the White Mountains, by which the Willey family lost their lives,
is an instance of the sort I refer to, though I am not able to say that in this
particular case the slip of the earth and rock was produced by the
denudation of the surface. It may have been occasioned by this cause, or by
the construction of the road through the Notch, the excavations for which,
perhaps, cut through the natural buttresses that supported the sloping strata
above.
Not to speak of the fall of earth when the roots which held it together,
and the bed of leaves and mould which sheltered it both from disintegrating
frost and from sudden drenching and dissolution by heavy showers, are
gone, it is easy to see that, in a climate with severe winters, the removal of
the forest, and, consequently, of the soil it had contributed to form, might
cause the displacement and descent of great masses of rock. The woods, the
vegetable mould, and the soil beneath, protect the rocks they cover from the
direct action of heat and cold, and from the expansion and contraction
which accompany them. Most rocks, while covered with earth, contain a
considerable quantity of water. [Footnote: Rock is permeable by water to a
greater extent than is generally supposed. Freshly quarried marble, and even
granite, as well as most other stones, are sensibly heavier, as well as softer
is due to the destruction of the forests—that the flanks of every Alpine
valley in Central Europe below the snow-line were once covered with earth
and green with woods, but there are not many particular cases in which we
can, with certainty, or even with strong probability, affirm the contrary.
Mountain Slides.
Terrible as are the ravages of the torrent and the river-flood, the
destruction of the woods exposes human life and industry to calamities even
more appalling than those which I have yet described. The slide in the
Notch of the White Mountains, by which the Willey family lost their lives,
is an instance of the sort I refer to, though I am not able to say that in this
particular case the slip of the earth and rock was produced by the
denudation of the surface. It may have been occasioned by this cause, or by
the construction of the road through the Notch, the excavations for which,
perhaps, cut through the natural buttresses that supported the sloping strata
above.
Not to speak of the fall of earth when the roots which held it together,
and the bed of leaves and mould which sheltered it both from disintegrating
frost and from sudden drenching and dissolution by heavy showers, are
gone, it is easy to see that, in a climate with severe winters, the removal of
the forest, and, consequently, of the soil it had contributed to form, might
cause the displacement and descent of great masses of rock. The woods, the
vegetable mould, and the soil beneath, protect the rocks they cover from the
direct action of heat and cold, and from the expansion and contraction
which accompany them. Most rocks, while covered with earth, contain a
considerable quantity of water. [Footnote: Rock is permeable by water to a
greater extent than is generally supposed. Freshly quarried marble, and even
granite, as well as most other stones, are sensibly heavier, as well as softer
Page 365
and more easily wrought, than after they are dried and hardened by air-
seasoning. Many sandstones are porous enough to serve as filters for
liquids, and much of that of Upper Egypt and Nubia hisses audibly when
thrown into water, from the escape of the air forced out of it by hydrostatic
pressure and the capillary attraction of the pores for water. Even the denser
silicious stones are penetrable by fluids and the coloring matter they
contain, to such an extent that agates and other forms of silex may be
artificially stained through their substance. The colors of the stones cut at
Oberstein are generally produced, or at least heightened, by art. This art was
known to and practised by the ancient lapidaries, and it has been revived in
recent times.]
A fragment of rock pervaded with moisture cracks and splits, if thrown
into a furnace, and sometimes with a loud detonation; and it is a familiar
observation that the fire, in burning over newly cleared lands, breaks up and
sometimes almost pulverizes the stones. This effect is due partly to the
unequal expansion of the stone, partly to the action of heat on the water it
contains in its pores. The sun, suddenly let in upon rock which had been
covered with moist earth for centuries, produces more or less disintegration
in the same way, and the stone is also exposed to chemical influences from
which it was sheltered before. But in the climate of the United States as
well as of the Alps, frost is a still more powerful agent in breaking up
mountain masses. The soil that protects the lime and sandstone, the slate
and the granite from the influence of the sun, also prevents the water which
filters into their crevices and between their strata from freezing in the
hardest winters, and the moisture descends, in a liquid form, until it escapes
in springs, or passes off by deep subterranean channels. But when the ridges
are laid bare, the water of the autumnal rains fills the minutest pores and
veins and fissures and lines of separation of the rocks, then suddenly
freezes, and bursts asunder huge, and apparently solid blocks of adamantine
stone. [Footnote: Palissy had observed the action of frost in disintegrating
seasoning. Many sandstones are porous enough to serve as filters for
liquids, and much of that of Upper Egypt and Nubia hisses audibly when
thrown into water, from the escape of the air forced out of it by hydrostatic
pressure and the capillary attraction of the pores for water. Even the denser
silicious stones are penetrable by fluids and the coloring matter they
contain, to such an extent that agates and other forms of silex may be
artificially stained through their substance. The colors of the stones cut at
Oberstein are generally produced, or at least heightened, by art. This art was
known to and practised by the ancient lapidaries, and it has been revived in
recent times.]
A fragment of rock pervaded with moisture cracks and splits, if thrown
into a furnace, and sometimes with a loud detonation; and it is a familiar
observation that the fire, in burning over newly cleared lands, breaks up and
sometimes almost pulverizes the stones. This effect is due partly to the
unequal expansion of the stone, partly to the action of heat on the water it
contains in its pores. The sun, suddenly let in upon rock which had been
covered with moist earth for centuries, produces more or less disintegration
in the same way, and the stone is also exposed to chemical influences from
which it was sheltered before. But in the climate of the United States as
well as of the Alps, frost is a still more powerful agent in breaking up
mountain masses. The soil that protects the lime and sandstone, the slate
and the granite from the influence of the sun, also prevents the water which
filters into their crevices and between their strata from freezing in the
hardest winters, and the moisture descends, in a liquid form, until it escapes
in springs, or passes off by deep subterranean channels. But when the ridges
are laid bare, the water of the autumnal rains fills the minutest pores and
veins and fissures and lines of separation of the rocks, then suddenly
freezes, and bursts asunder huge, and apparently solid blocks of adamantine
stone. [Footnote: Palissy had observed the action of frost in disintegrating
Page 366
rock, and he thus describes it, in his essay on the formation of ice: "I know
that the stones of the mountains of Ardennes be harder than marble.
Nevertheless, the people of that country do not quarry the said stones in
winter, for that they be subject to frost; and many times the rocks have been
seen to fall without being cut, by means whereof many people have been
killed, when the said rocks were thawing." Palissy was ignorant of the
expansion of water in freezing—in fact, he supposed that the mechanical
force exerted by freezing-water was due to compression, not dilatation—
and therefore he ascribes to thawing alone effects resulting not less from
congelation.
Various forces combine to produce the stone avalanches of the higher
Alps, the fall of which is one of the greatest dangers incurred by the
adventurous explorers of those regions—the direct action of the sun upon
the stone, the expansion of freezing-water, and the loosening of masses of
rock by the thawing of the ice which supported them or held them together.]
Where the strata are inclined at a considerable angle, the freezing of a
thin film of water over a large interstratal area might occasion a slide that
should cover miles with its ruins; and similar results might be produced by
the simple hydrostatic pressure of a column of water, admitted, by the
removal of the covering of earth, to flow into a crevice faster than it could
escape through orifices below. Earth or rather mountain slides, compared to
which the catastrophe that buried the Willey family in New Hampshire was
but a pinch of dust, have often occurred in the Swiss, Italian, and French
Alps. The land-slip, which overwhelmed, and covered to the depth of
seventy feet, the town of Plurs in the valley of the Maira, on the night of the
4th of September, 1618, sparing not a soul of a population of 2,430
inhabitants, is one of the most memorable of these catastrophes, and the fall
of the Rossberg or Rufiberg, which destroyed the little town of Goldan in
Switzerland, and 450 of its people, on the 2d of September, 1806, is almost
that the stones of the mountains of Ardennes be harder than marble.
Nevertheless, the people of that country do not quarry the said stones in
winter, for that they be subject to frost; and many times the rocks have been
seen to fall without being cut, by means whereof many people have been
killed, when the said rocks were thawing." Palissy was ignorant of the
expansion of water in freezing—in fact, he supposed that the mechanical
force exerted by freezing-water was due to compression, not dilatation—
and therefore he ascribes to thawing alone effects resulting not less from
congelation.
Various forces combine to produce the stone avalanches of the higher
Alps, the fall of which is one of the greatest dangers incurred by the
adventurous explorers of those regions—the direct action of the sun upon
the stone, the expansion of freezing-water, and the loosening of masses of
rock by the thawing of the ice which supported them or held them together.]
Where the strata are inclined at a considerable angle, the freezing of a
thin film of water over a large interstratal area might occasion a slide that
should cover miles with its ruins; and similar results might be produced by
the simple hydrostatic pressure of a column of water, admitted, by the
removal of the covering of earth, to flow into a crevice faster than it could
escape through orifices below. Earth or rather mountain slides, compared to
which the catastrophe that buried the Willey family in New Hampshire was
but a pinch of dust, have often occurred in the Swiss, Italian, and French
Alps. The land-slip, which overwhelmed, and covered to the depth of
seventy feet, the town of Plurs in the valley of the Maira, on the night of the
4th of September, 1618, sparing not a soul of a population of 2,430
inhabitants, is one of the most memorable of these catastrophes, and the fall
of the Rossberg or Rufiberg, which destroyed the little town of Goldan in
Switzerland, and 450 of its people, on the 2d of September, 1806, is almost
Page 367
equally celebrated. In 1771, according to Wessely, the mountain-peak Piz,
near Alleghe in the province of Belluno, slipped into the bed of the
Cordevole, a tributary of the Piave, destroying in its fall three hamlets and
sixty lives. The rubbish filled the valley for a distance of nearly two miles,
and, by damming up the waters of the Cordevole, formed a lake about three
miles long, and a hundred and fifty feet deep, which still subsists, though
reduced to half its original length by the wearing down of its outlet.
[Footnote: Wessely, Die Oesterreichischen Alpenlander und ihre Forste, pp.
125, 126. Wessely records several other more or less similar occurrences in
the Austrian Alps. Some of them, certainly, are not to be ascribed to the
removal of the woods, but in most cases they are clearly traceable to that
cause. See Revue des Eaux et Forets for 1860, pp. 182, 205.]
The important provincial town of Veleia, near Piacenza, where many
interesting antiquities have been discovered within a few years, was buried
by a vast land-slip, probably about the time of Probus, but no historical
record of the event has survived to us.
On the 14th of February, 1855, the hill of Belmonte, a little below the
parish of San Stefano, in Tuscany, slid into the valley of the Tiber, which
consequently flooded the village to the depth of fifty feet, and was finally
drained off by a tunnel. The mass of debris is stated to have been about
3,500 feet long, 1,000 wide, and not less than 600 high. [Footnote: Bianchi,
Appendix to the Italian translation of Mrs. Somerville'S Physical
Geography, p. xxxvi.]
Occurrences of this sort have been so numerous in the Alps and
Apennines, that almost every Italian mountain commune has its tradition,
its record, or its still visible traces of a great land-slip within its own limits.
The old chroniclers contain frequent notices of such calamities, and
Giovanni Villani even records the destruction of fifty houses and the loss of
near Alleghe in the province of Belluno, slipped into the bed of the
Cordevole, a tributary of the Piave, destroying in its fall three hamlets and
sixty lives. The rubbish filled the valley for a distance of nearly two miles,
and, by damming up the waters of the Cordevole, formed a lake about three
miles long, and a hundred and fifty feet deep, which still subsists, though
reduced to half its original length by the wearing down of its outlet.
[Footnote: Wessely, Die Oesterreichischen Alpenlander und ihre Forste, pp.
125, 126. Wessely records several other more or less similar occurrences in
the Austrian Alps. Some of them, certainly, are not to be ascribed to the
removal of the woods, but in most cases they are clearly traceable to that
cause. See Revue des Eaux et Forets for 1860, pp. 182, 205.]
The important provincial town of Veleia, near Piacenza, where many
interesting antiquities have been discovered within a few years, was buried
by a vast land-slip, probably about the time of Probus, but no historical
record of the event has survived to us.
On the 14th of February, 1855, the hill of Belmonte, a little below the
parish of San Stefano, in Tuscany, slid into the valley of the Tiber, which
consequently flooded the village to the depth of fifty feet, and was finally
drained off by a tunnel. The mass of debris is stated to have been about
3,500 feet long, 1,000 wide, and not less than 600 high. [Footnote: Bianchi,
Appendix to the Italian translation of Mrs. Somerville'S Physical
Geography, p. xxxvi.]
Occurrences of this sort have been so numerous in the Alps and
Apennines, that almost every Italian mountain commune has its tradition,
its record, or its still visible traces of a great land-slip within its own limits.
The old chroniclers contain frequent notices of such calamities, and
Giovanni Villani even records the destruction of fifty houses and the loss of
Page 368
many lives by a slide of what seems to have been a spur of the hill of San
Giorgio in the city of Florence, in the year 1284. [Footnote: Cronica di
Giovani Villani, lib. vii., cap. 97. For descriptions of other slides in Italy,
see same author, lib. xi, cap. 26; Fanfani, Antologia Italiana, parte ii., p. 95;
Giuliani, Linguaggio vivente della Toscana, 1865, lettera 63.]
Such displacements of earth and rocky strata rise to the magnitude of
geological convulsions, but they are of so rare occurrence in countries still
covered by the primitive forest, so common where the mountains have been
stripped of their native covering, and, in many cases, so easily explicable by
the drenching of incohesive earth from rain, or the free admission of water
between the strata of rocks—both of which a coating of vegetation would
have prevented—that we are justified in ascribing them for the most part to
the same cause as that to which the destructive effects of mountain torrents
are chiefly due—the felling of the woods. [Footnote: There is good reason
for thinking that many of the earth and rock slides in the Alps occurred at an
earlier period than the origin of the forest vegetation which, in later ages,
covered the flanks of those mountains. See Bericht uber die Untersuchung
der Schweizerischen Hochgebirgswaldungen, 1862, p. 61.
Where more recent slides have been again clothed with woods, the trees,
shrubs, and smaller plants which spontaneously grow upon them are usually
of different species from those observed upon soil displaced at remote
periods. This difference is so marked that the site of a slide can often be
recognized at a great distance by the general color of the foliage of its
vegetation.]
In nearly every case of this sort the circumstances of which are known—
except the rare instances attributable to earthquakes—the immediate cause
of the slip has been the imbibition of water in large quantities by bare earth,
or its introduction between or beneath solid strata. If water insinuates itself
Giorgio in the city of Florence, in the year 1284. [Footnote: Cronica di
Giovani Villani, lib. vii., cap. 97. For descriptions of other slides in Italy,
see same author, lib. xi, cap. 26; Fanfani, Antologia Italiana, parte ii., p. 95;
Giuliani, Linguaggio vivente della Toscana, 1865, lettera 63.]
Such displacements of earth and rocky strata rise to the magnitude of
geological convulsions, but they are of so rare occurrence in countries still
covered by the primitive forest, so common where the mountains have been
stripped of their native covering, and, in many cases, so easily explicable by
the drenching of incohesive earth from rain, or the free admission of water
between the strata of rocks—both of which a coating of vegetation would
have prevented—that we are justified in ascribing them for the most part to
the same cause as that to which the destructive effects of mountain torrents
are chiefly due—the felling of the woods. [Footnote: There is good reason
for thinking that many of the earth and rock slides in the Alps occurred at an
earlier period than the origin of the forest vegetation which, in later ages,
covered the flanks of those mountains. See Bericht uber die Untersuchung
der Schweizerischen Hochgebirgswaldungen, 1862, p. 61.
Where more recent slides have been again clothed with woods, the trees,
shrubs, and smaller plants which spontaneously grow upon them are usually
of different species from those observed upon soil displaced at remote
periods. This difference is so marked that the site of a slide can often be
recognized at a great distance by the general color of the foliage of its
vegetation.]
In nearly every case of this sort the circumstances of which are known—
except the rare instances attributable to earthquakes—the immediate cause
of the slip has been the imbibition of water in large quantities by bare earth,
or its introduction between or beneath solid strata. If water insinuates itself
Page 369
between the strata, it creates a sliding surface, or it may, by its expansion in
freezing, separate beds of rock, which had been nearly continuous before,
widely enough to allow the gravitation of the superincumbent mass to
overcome the resistance afforded by inequalities of face and by friction; if it
finds its way beneath hard earth or rock reposing on clay or other bedding
of similar properties, it converts the supporting layer into a semi-fluid mud,
which opposes no obstacle to the sliding of the strata above.
The upper part of the mountain which buried Goldau was composed of a
hard but brittle conglomerate, called nagelflue, resting on unctuous clay,
and inclining rapidly towards the village. Much earth remained upon the
rock, in irregular masses, but the woods had been felled, and the water had
free access to the surface, and to the crevices which sun and frost had
already produced in the rock, and, of course, to the slimy stratum beneath.
The whole summer of 1806 had been very wet, and an almost incessant
deluge of rain had fallen the day preceding the catastrophe, as well as on
that of its occurrence. All conditions, then, were favorable to the sliding of
the rock, and, in obedience to the laws of gravitation, it precipitated itself
into the valley as soon as its adhesion to the earth beneath it was destroyed
by the conversion of the latter into a viscous paste. The mass that fell
measured between two and a half and three miles in length by one thousand
feet in width, and its average thickness is thought to have been about a
hundred feet. The highest portion of the mountain was more than three
thousand feet above the village, and the momentum acquired by the rocks
and earth in their descent carried huge blocks of stone far up the opposite
slope of the Rigi.
The Piz, which fell into the Cordevole, rested on a steeply inclined
stratum of limestone, with a thin layer of calcareous marl intervening,
which, by long exposure to frost and the infiltration of water, had lost its
freezing, separate beds of rock, which had been nearly continuous before,
widely enough to allow the gravitation of the superincumbent mass to
overcome the resistance afforded by inequalities of face and by friction; if it
finds its way beneath hard earth or rock reposing on clay or other bedding
of similar properties, it converts the supporting layer into a semi-fluid mud,
which opposes no obstacle to the sliding of the strata above.
The upper part of the mountain which buried Goldau was composed of a
hard but brittle conglomerate, called nagelflue, resting on unctuous clay,
and inclining rapidly towards the village. Much earth remained upon the
rock, in irregular masses, but the woods had been felled, and the water had
free access to the surface, and to the crevices which sun and frost had
already produced in the rock, and, of course, to the slimy stratum beneath.
The whole summer of 1806 had been very wet, and an almost incessant
deluge of rain had fallen the day preceding the catastrophe, as well as on
that of its occurrence. All conditions, then, were favorable to the sliding of
the rock, and, in obedience to the laws of gravitation, it precipitated itself
into the valley as soon as its adhesion to the earth beneath it was destroyed
by the conversion of the latter into a viscous paste. The mass that fell
measured between two and a half and three miles in length by one thousand
feet in width, and its average thickness is thought to have been about a
hundred feet. The highest portion of the mountain was more than three
thousand feet above the village, and the momentum acquired by the rocks
and earth in their descent carried huge blocks of stone far up the opposite
slope of the Rigi.
The Piz, which fell into the Cordevole, rested on a steeply inclined
stratum of limestone, with a thin layer of calcareous marl intervening,
which, by long exposure to frost and the infiltration of water, had lost its
Page 370
original consistence, and become a loose and slippery mass instead of a
cohesive and tenacious bed.
Protection against Avalanches.
In Switzerland and other snowy and mountainous countries, forests
render a most important service by preventing the formation and fall of
destructive avalanches, and in many parts of the Alps exposed to this
catastrophe, the woods are protected, though too often ineffectually, by law.
No forest, indeed, could arrest a large avalanche once in full motion, but the
mechanical resistance afforded by the trees prevents their formation, both
by obstructing the wind, which gives to the dry snow of the Staub-Lawine,
or dust-avalanche, its first impulse, and by checking the disposition of moist
snow to gather itself into what is called the Rutsch-Lawine, or sliding
avalanche. Marchand states that, the very first winter after the felling of the
trees on the higher part of a declivity between Sannen and Gsteig where the
snow had never been known to slide, an avalanche formed itself in the
clearing, thundered down the mountain, and overthrew and carried with it a
hitherto unviolated forest to the amount of nearly a million cubic feet of
timber. [Footnote: Entwaldung der Gebirge, p. 41.] Elisee Reclus informs us
in his remarkable work, La Terre, vol. i., p. 212, that a mountain, which
rises to the south of the Pyrenaean village Araguanet in the upper valley of
the Neste, having been partially stripped of its woods, a formidable
avalanche rushed down from a plateau above in 1846, and swept off more
than 15,000 pine-trees. The path once opened down the flanks of the
mountain, the evil is almost beyond remedy. The snow sometimes carries
off the earth from the face of the rock, or, if the soil is left, fresh slides
every winter destroy the young plantations, and the restoration of the wood
becomes impossible. The track widens with every new avalanche.
Dwellings and their occupants are buried in the snow, or swept away by the
cohesive and tenacious bed.
Protection against Avalanches.
In Switzerland and other snowy and mountainous countries, forests
render a most important service by preventing the formation and fall of
destructive avalanches, and in many parts of the Alps exposed to this
catastrophe, the woods are protected, though too often ineffectually, by law.
No forest, indeed, could arrest a large avalanche once in full motion, but the
mechanical resistance afforded by the trees prevents their formation, both
by obstructing the wind, which gives to the dry snow of the Staub-Lawine,
or dust-avalanche, its first impulse, and by checking the disposition of moist
snow to gather itself into what is called the Rutsch-Lawine, or sliding
avalanche. Marchand states that, the very first winter after the felling of the
trees on the higher part of a declivity between Sannen and Gsteig where the
snow had never been known to slide, an avalanche formed itself in the
clearing, thundered down the mountain, and overthrew and carried with it a
hitherto unviolated forest to the amount of nearly a million cubic feet of
timber. [Footnote: Entwaldung der Gebirge, p. 41.] Elisee Reclus informs us
in his remarkable work, La Terre, vol. i., p. 212, that a mountain, which
rises to the south of the Pyrenaean village Araguanet in the upper valley of
the Neste, having been partially stripped of its woods, a formidable
avalanche rushed down from a plateau above in 1846, and swept off more
than 15,000 pine-trees. The path once opened down the flanks of the
mountain, the evil is almost beyond remedy. The snow sometimes carries
off the earth from the face of the rock, or, if the soil is left, fresh slides
every winter destroy the young plantations, and the restoration of the wood
becomes impossible. The track widens with every new avalanche.
Dwellings and their occupants are buried in the snow, or swept away by the
Page 371
rushing mass, or by the furious blasts it occasions through the displacement
of the air; roads and bridges are destroyed; rivers blocked up, which swell
till they overflow the valley above, and then, bursting their snowy barrier,
flood the fields below with all the horrors of a winter inundation. [Footnote:
The importance of the wood in preventing avalanches is well illustrated by
the fact that, where the forest is wanting, the inhabitants of localities
exposed to snow-slides often supply the place of the trees by driving stakes
through the snow into the ground, and thus checking its propensity to slip.
The woods themselves are sometimes thus protected against avalanches
originating on slopes above them, and as a further security, small trees are
cut down along the upper line of the forest, and laid against the trunks of
larger trees, transversely to the path of the slide, to serve as a fence or dam
to the motion of an incipient avalanche, which may by this means be
arrested before it acquires a destructive velocity and force.
In the volume cited in the text, Reclus informs us that "the village and the
great thermal establishment of Bareges in the Pyrenees were threatened
yearly by avalanches which precipitated themselves from a height of 1,200
metres and at an angle of 35 degrees; so that the inhabitants had been
obliged to leave large spaces between the different quarters of the town for
the free passage of the descending masses. Attempts have been recently
made to prevent those avalanches by means similar to those employed by
the Swiss mountaineers. They cut terraces three or four yards in width
across the mountain slopes and supported these terraces by a row of iron
piles. Wattled fences, with here and there a wall of stone, shelter the young
shoots of trees, which grow up by degrees under the protection of these
defences. Until natural trees are ready to arrest the snows, these artificial
supports take their place and do their duty very well. The only avalanche
which swept down the slope in the year 1860, when these works were
completed, did not amount to 350 cubic yards, while the masses which fell
of the air; roads and bridges are destroyed; rivers blocked up, which swell
till they overflow the valley above, and then, bursting their snowy barrier,
flood the fields below with all the horrors of a winter inundation. [Footnote:
The importance of the wood in preventing avalanches is well illustrated by
the fact that, where the forest is wanting, the inhabitants of localities
exposed to snow-slides often supply the place of the trees by driving stakes
through the snow into the ground, and thus checking its propensity to slip.
The woods themselves are sometimes thus protected against avalanches
originating on slopes above them, and as a further security, small trees are
cut down along the upper line of the forest, and laid against the trunks of
larger trees, transversely to the path of the slide, to serve as a fence or dam
to the motion of an incipient avalanche, which may by this means be
arrested before it acquires a destructive velocity and force.
In the volume cited in the text, Reclus informs us that "the village and the
great thermal establishment of Bareges in the Pyrenees were threatened
yearly by avalanches which precipitated themselves from a height of 1,200
metres and at an angle of 35 degrees; so that the inhabitants had been
obliged to leave large spaces between the different quarters of the town for
the free passage of the descending masses. Attempts have been recently
made to prevent those avalanches by means similar to those employed by
the Swiss mountaineers. They cut terraces three or four yards in width
across the mountain slopes and supported these terraces by a row of iron
piles. Wattled fences, with here and there a wall of stone, shelter the young
shoots of trees, which grow up by degrees under the protection of these
defences. Until natural trees are ready to arrest the snows, these artificial
supports take their place and do their duty very well. The only avalanche
which swept down the slope in the year 1860, when these works were
completed, did not amount to 350 cubic yards, while the masses which fell
Page 372
before this work was undertaken contained from 75,000 to 80,000 cubic
yards."—La Terre, vol. i., p. 233.]
Minor Uses of the Forest.
Besides the important conservative influences of the forest and its value
as the source of supply of a material indispensable to all the arts and
industries of human life, it renders other services of a less obvious and less
generally recognized character.
Woods often subserve a valuable purpose in preventing the fall of rocks,
by mere mechanical resistance. Trees, as well as herbaceous vegetation,
grow in the Alps upon declivities of surprising steepness of inclination, and
the traveller sees both luxuriant grass and flourishing woods on slopes at
which the soil, in the dry air of lower regions, would crumble and fall by
the weight of its own particles. When loose rocks lie scattered on the face of
these declivities, they are held in place by the trunks of the trees, and it is
very common to observe a stone that weighs hundreds of pounds, perhaps
even tons, resting against a tree which has stopped its progress just as it was
beginning to slide down to a lower level. When a forest in such a position is
cut, these blocks lose their support, and a single wet season is enough not
only to bare the face of a considerable extent of rock, but to cover with
earth and stone many acres of fertile soil below. [Footnote: See in Kohl,
Alpenreisen, i., 120, an account of the ruin of fields and pastures, and even
of the destruction of a broad belt of forest, by the fall of rocks in
consequence of cutting a few large trees. Cattle are very often killed in
Switzerland by rock-avalanches, and their owners secure themselves from
loss by insurance against this risk as against damage by fire or hail.]
In alluvial plains and on the banks of rivers trees are extremely useful as
a check to the swift flow of the water in inundations, and the spread of the
yards."—La Terre, vol. i., p. 233.]
Minor Uses of the Forest.
Besides the important conservative influences of the forest and its value
as the source of supply of a material indispensable to all the arts and
industries of human life, it renders other services of a less obvious and less
generally recognized character.
Woods often subserve a valuable purpose in preventing the fall of rocks,
by mere mechanical resistance. Trees, as well as herbaceous vegetation,
grow in the Alps upon declivities of surprising steepness of inclination, and
the traveller sees both luxuriant grass and flourishing woods on slopes at
which the soil, in the dry air of lower regions, would crumble and fall by
the weight of its own particles. When loose rocks lie scattered on the face of
these declivities, they are held in place by the trunks of the trees, and it is
very common to observe a stone that weighs hundreds of pounds, perhaps
even tons, resting against a tree which has stopped its progress just as it was
beginning to slide down to a lower level. When a forest in such a position is
cut, these blocks lose their support, and a single wet season is enough not
only to bare the face of a considerable extent of rock, but to cover with
earth and stone many acres of fertile soil below. [Footnote: See in Kohl,
Alpenreisen, i., 120, an account of the ruin of fields and pastures, and even
of the destruction of a broad belt of forest, by the fall of rocks in
consequence of cutting a few large trees. Cattle are very often killed in
Switzerland by rock-avalanches, and their owners secure themselves from
loss by insurance against this risk as against damage by fire or hail.]
In alluvial plains and on the banks of rivers trees are extremely useful as
a check to the swift flow of the water in inundations, and the spread of the
Page 373
mineral material it transports; but this will be more appropriately
considered in the chapter on the Waters; and another most important use of
the woods, that of confining the loose sands of dunes and plains, will be
treated of in the chapter on the Sands.
Small Forest Plants, and Vitality of Seed.
Another function of the woods, to which I have barely alluded, deserves
a fuller notice than can be bestowed upon it in a treatise the scope of which
is purely economical. The forest is the native habitat of a large number of
humbler plants, to the growth and perpetuation of which its shade, its
humidity, and its vegetable mould appear to be indispensable necessities.
[Footnote: "A hundred and fifty paces from my house is a hill of drift-sand,
on which stood a few scattered pines (Pinus sylvestris). Sempervivum
tectorum in abundance, Statice armeria, Ammone vernalis, Dianthus
carthusianorum, with other sand-plants, were growing there. I planted the
hill with a few birches, and all the plants I have mentioned completely
disappeared, though there were many naked spots of sand between the trees.
It should be added, however, that the hillock is more thickly wooded than
before. . . . It seems then that Sempervivum tectorum, etc., will not bear the
neighborhood of the birch, though growing well near the Pinus sylvestris. I
have found the large red variety of Agaricus deliciosus only among the
roots of the pine; the greenish-blue Agaricus deliciosus among alder roots,
but not near any other tree. Birds have their partialities among trees and
shrubs. The Silvioe prefer the Pinus Larix to other trees. In my garden this
Pinus is never without them, but I never saw a bird perch on Thuja
occidentalis or Juniperus sabina, although the thick foliage of these latter
trees affords birds a better shelter than the loose leafage of other trees. Not
even a wren ever finds its way to one of them. Perhaps the scent of the
Thuja and the Juniperus is offensive to them. I have spoiled one of my
considered in the chapter on the Waters; and another most important use of
the woods, that of confining the loose sands of dunes and plains, will be
treated of in the chapter on the Sands.
Small Forest Plants, and Vitality of Seed.
Another function of the woods, to which I have barely alluded, deserves
a fuller notice than can be bestowed upon it in a treatise the scope of which
is purely economical. The forest is the native habitat of a large number of
humbler plants, to the growth and perpetuation of which its shade, its
humidity, and its vegetable mould appear to be indispensable necessities.
[Footnote: "A hundred and fifty paces from my house is a hill of drift-sand,
on which stood a few scattered pines (Pinus sylvestris). Sempervivum
tectorum in abundance, Statice armeria, Ammone vernalis, Dianthus
carthusianorum, with other sand-plants, were growing there. I planted the
hill with a few birches, and all the plants I have mentioned completely
disappeared, though there were many naked spots of sand between the trees.
It should be added, however, that the hillock is more thickly wooded than
before. . . . It seems then that Sempervivum tectorum, etc., will not bear the
neighborhood of the birch, though growing well near the Pinus sylvestris. I
have found the large red variety of Agaricus deliciosus only among the
roots of the pine; the greenish-blue Agaricus deliciosus among alder roots,
but not near any other tree. Birds have their partialities among trees and
shrubs. The Silvioe prefer the Pinus Larix to other trees. In my garden this
Pinus is never without them, but I never saw a bird perch on Thuja
occidentalis or Juniperus sabina, although the thick foliage of these latter
trees affords birds a better shelter than the loose leafage of other trees. Not
even a wren ever finds its way to one of them. Perhaps the scent of the
Thuja and the Juniperus is offensive to them. I have spoiled one of my
Page 374
meadows by cutting away the bushes. It formerly bore grass four feet high,
because many umbelliferous plants, such as Heracleum spondylium,
Spiraea ulmaria, Laserpitium latifolia, etc., grew in it. Under the shelter of
the bushes these plants ripened and bore seed, but they gradually
disappeared as the shrubs wore extirpated, and the grass now does not grow
to the height of more than two feet, because it is no longer obliged to keep
pace with the umbellifera which flourished among it." See a paper by J.G.
Buttner, of Kurland, in Berghaus s Geographicsches Jahrbuch, 1852, No. 4,
pp. 14, 15.
These facts are interesting as illustrating the multitude of often obscure
conditions upon which the life or vigorous growth of smaller organisms
depends. Particular species of truffles and of mushrooms are found
associated with particular trees, without being, as is popularly supposed,
parasites deriving their nutriment from the dying or dead roots of those
trees. The success of Rousseau's experiments seem decisive on this point,
for he obtains larger crops of truffles from ground covered with young
seedling oaks than from that filled with roots of old trees. See an article on
Mont Ventoux, by Charles Martins, in the Revue des Deux Mondes, Avril,
1863, p. 626.
It ought to be much more generally known than it is, that most if not all
mushrooms, even of the species reputed poisonous, may be rendered
harmless and healthful as food by soaking them for two hours in acidulated
or salt water. The water requires two or three spoonfuls of vinegar or two
spoonful of gray salt to the quart, and a quart of water is enough for a pound
of sliced mushrooms. After thus soaking, they are well washed in fresh
water, thrown into cold water, which is raised to the boiling-point, and, after
remaining half an hour, taken out and again washed, Gerard, to prove that
"crumpets is wholesome," ate one hundred and seventy-five pounds of the
most poisonous mushrooms thus prepared, in a single month, fed his family
because many umbelliferous plants, such as Heracleum spondylium,
Spiraea ulmaria, Laserpitium latifolia, etc., grew in it. Under the shelter of
the bushes these plants ripened and bore seed, but they gradually
disappeared as the shrubs wore extirpated, and the grass now does not grow
to the height of more than two feet, because it is no longer obliged to keep
pace with the umbellifera which flourished among it." See a paper by J.G.
Buttner, of Kurland, in Berghaus s Geographicsches Jahrbuch, 1852, No. 4,
pp. 14, 15.
These facts are interesting as illustrating the multitude of often obscure
conditions upon which the life or vigorous growth of smaller organisms
depends. Particular species of truffles and of mushrooms are found
associated with particular trees, without being, as is popularly supposed,
parasites deriving their nutriment from the dying or dead roots of those
trees. The success of Rousseau's experiments seem decisive on this point,
for he obtains larger crops of truffles from ground covered with young
seedling oaks than from that filled with roots of old trees. See an article on
Mont Ventoux, by Charles Martins, in the Revue des Deux Mondes, Avril,
1863, p. 626.
It ought to be much more generally known than it is, that most if not all
mushrooms, even of the species reputed poisonous, may be rendered
harmless and healthful as food by soaking them for two hours in acidulated
or salt water. The water requires two or three spoonfuls of vinegar or two
spoonful of gray salt to the quart, and a quart of water is enough for a pound
of sliced mushrooms. After thus soaking, they are well washed in fresh
water, thrown into cold water, which is raised to the boiling-point, and, after
remaining half an hour, taken out and again washed, Gerard, to prove that
"crumpets is wholesome," ate one hundred and seventy-five pounds of the
most poisonous mushrooms thus prepared, in a single month, fed his family
Page 375
ad libitum with the same, and finally administered them, in heroic doses, to
the members of a committee appointed by the Council of Health of the city
of Paris. See Figuier, L'Annee Scientifique, 1862, pp. 353, 384. It should be
observed that the venomous principle of poisonous mushrooms is not
decomposed and rendered innocent by the process described in the note. It
is merely extracted by the acidulated or saline water employed for soaking
the plants, and care should be taken that this water be thrown away out of
the reach of mischief.
It has long been known that the Russian peasantry eat, with impunity,
mushrooms of species everywhere else regarded as very poisonous. Is it not
probable that the secret of rendering them harmless—which was known to
Pliny, though since forgotten in Italy—is possessed by the rustic
Muscovites ]
We cannot positively say that the felling of the woods in a given
vegetable province would involve the final extinction of the smaller plants
which are found only within their precincts. Some of these, though not
naturally propagating themselves in the open ground, may perhaps
germinate and grow under artificial stimulation and protection, and finally
become hardy enough to maintain an independent existence in very
different circumstances from those which at present seem essential to their
life.
Besides this, although the accounts of the growth of seeds, which have
lain for ages in the ashy dryness of Egyptian catacombs, are to be received
with great caution, or, more probably, to be rejected altogether, yet their
vitality seems almost imperishable while they remain in the situations in
which nature deposits them. When a forest old enough to have witnessed
the mysteries of the Druids is felled, trees of other species spring up in its
place; and when they, in their turn, fall before the axe, sometimes even as
the members of a committee appointed by the Council of Health of the city
of Paris. See Figuier, L'Annee Scientifique, 1862, pp. 353, 384. It should be
observed that the venomous principle of poisonous mushrooms is not
decomposed and rendered innocent by the process described in the note. It
is merely extracted by the acidulated or saline water employed for soaking
the plants, and care should be taken that this water be thrown away out of
the reach of mischief.
It has long been known that the Russian peasantry eat, with impunity,
mushrooms of species everywhere else regarded as very poisonous. Is it not
probable that the secret of rendering them harmless—which was known to
Pliny, though since forgotten in Italy—is possessed by the rustic
Muscovites ]
We cannot positively say that the felling of the woods in a given
vegetable province would involve the final extinction of the smaller plants
which are found only within their precincts. Some of these, though not
naturally propagating themselves in the open ground, may perhaps
germinate and grow under artificial stimulation and protection, and finally
become hardy enough to maintain an independent existence in very
different circumstances from those which at present seem essential to their
life.
Besides this, although the accounts of the growth of seeds, which have
lain for ages in the ashy dryness of Egyptian catacombs, are to be received
with great caution, or, more probably, to be rejected altogether, yet their
vitality seems almost imperishable while they remain in the situations in
which nature deposits them. When a forest old enough to have witnessed
the mysteries of the Druids is felled, trees of other species spring up in its
place; and when they, in their turn, fall before the axe, sometimes even as
Page 376
soon as they have spread their protecting shade over the surface, the germs
which their predecessors had shed years, perhaps centuries before, sprout
up, and in due time, if not choked by other trees belonging to a later stage in
the order of natural succession, restore again the original wood. In these
cases, the seeds of the new crop may have been brought by the wind, by
birds, by quadrupeds, or by other causes; but, in many instances, this
explanation is not probable.
When newly cleared ground is burnt over in the United States, the ashes
are hardly cold before they are covered with a crop of fire-weed, Senecio
hieracifolius, a tall, herbaceous plant, very seldom seen growing under
other circumstances, and often not to be found for a distance of many miles
from the clearing. Its seeds, whether the fruit of an ancient vegetation or
newly sown by winds or birds, require either a quickening by a heat which
raises to a certain high point the temperature of the stratum where they lie
buried, or a special pabulum furnished only by the combustion of the
vegetable remains that cover the ground in the woods.
Earth brought up from wells or other excavations soon produces a harvest
of plants often very unlike those of the local flora, and Hayden informs us
that on our great Western desert plains, "wherever the earth is broken up,
the wild sun-flower (Helianthus) and others of the taller-growing plants,
though previously unknown in the vicinity, at once spring up, almost as if
spontaneous generation had taken place." [Footnote: Geological Survey of
Wyoming, p. 455.]
Moritz Wagner, as quoted by Wittwer, [Footnote: Physikalische
Geographie, p. 486.] remarks in his description of Mount Ararat: "A
singular phenomenon to which my guide drew my attention is the
appearance of several plants on the earth-heaps left by the last catastrophe
[an earthquake], which grow nowhere else on the mountain, and had never
which their predecessors had shed years, perhaps centuries before, sprout
up, and in due time, if not choked by other trees belonging to a later stage in
the order of natural succession, restore again the original wood. In these
cases, the seeds of the new crop may have been brought by the wind, by
birds, by quadrupeds, or by other causes; but, in many instances, this
explanation is not probable.
When newly cleared ground is burnt over in the United States, the ashes
are hardly cold before they are covered with a crop of fire-weed, Senecio
hieracifolius, a tall, herbaceous plant, very seldom seen growing under
other circumstances, and often not to be found for a distance of many miles
from the clearing. Its seeds, whether the fruit of an ancient vegetation or
newly sown by winds or birds, require either a quickening by a heat which
raises to a certain high point the temperature of the stratum where they lie
buried, or a special pabulum furnished only by the combustion of the
vegetable remains that cover the ground in the woods.
Earth brought up from wells or other excavations soon produces a harvest
of plants often very unlike those of the local flora, and Hayden informs us
that on our great Western desert plains, "wherever the earth is broken up,
the wild sun-flower (Helianthus) and others of the taller-growing plants,
though previously unknown in the vicinity, at once spring up, almost as if
spontaneous generation had taken place." [Footnote: Geological Survey of
Wyoming, p. 455.]
Moritz Wagner, as quoted by Wittwer, [Footnote: Physikalische
Geographie, p. 486.] remarks in his description of Mount Ararat: "A
singular phenomenon to which my guide drew my attention is the
appearance of several plants on the earth-heaps left by the last catastrophe
[an earthquake], which grow nowhere else on the mountain, and had never
Page 377
been observed in this region before. The seeds of these plants were
probably brought by birds, and found in the loose, clayey soil remaining
from the streams of mud, the conditions of growth which the other soil of
the mountain refused them." This is probable enough, but it is hardly less so
that the flowing mud brought them up to the influence of air and sun, from
depths where a previous convulsion had buried them ages before.
Seeds of small sylvan plants, too deeply buried by successive layers of
forest foliage and the mould resulting from its decomposition to be reached
by the plough when the trees are gone and the ground brought under
cultivation, may, if a wiser posterity replants the wood which sheltered their
parent stems, germinate and grow, after lying for generations in a state of
suspended animation.
Darwin says: "On the estate of a relation there was a large and extremely
barren heath, which had never been touched by the hand of man, but several
hundred acres of exactly the same nature had been enclosed twenty-five
years previously and planted with Scotch fir. The change in the native
vegetation of the planted part of the heath was most remarkable—more than
is generally seen in passing from one quite different soil to another; not
only the proportional numbers of the heath-plants were wholly changed, but
TWELVE SPECIES of plants (not counting grasses and sedges) flourished
in the plantation which could not be found on the heath." [Footnote: Origin
of Species, American edition, p. 60.] Had the author informed us that these
twelve plants belonged to species whose seeds enter into the nutriment of
the birds which appeared with the young wood, we could easily account for
their presence in the soil; but he says distinctly that the birds were of
insectivorous species, and it therefore seems more probable that the seeds
had been deposited when an ancient forest protected the growth of the
plants which bore them, and that they sprang up to new life when a return
of favorable conditions awaked them from a sleep of centuries. Darwin
probably brought by birds, and found in the loose, clayey soil remaining
from the streams of mud, the conditions of growth which the other soil of
the mountain refused them." This is probable enough, but it is hardly less so
that the flowing mud brought them up to the influence of air and sun, from
depths where a previous convulsion had buried them ages before.
Seeds of small sylvan plants, too deeply buried by successive layers of
forest foliage and the mould resulting from its decomposition to be reached
by the plough when the trees are gone and the ground brought under
cultivation, may, if a wiser posterity replants the wood which sheltered their
parent stems, germinate and grow, after lying for generations in a state of
suspended animation.
Darwin says: "On the estate of a relation there was a large and extremely
barren heath, which had never been touched by the hand of man, but several
hundred acres of exactly the same nature had been enclosed twenty-five
years previously and planted with Scotch fir. The change in the native
vegetation of the planted part of the heath was most remarkable—more than
is generally seen in passing from one quite different soil to another; not
only the proportional numbers of the heath-plants were wholly changed, but
TWELVE SPECIES of plants (not counting grasses and sedges) flourished
in the plantation which could not be found on the heath." [Footnote: Origin
of Species, American edition, p. 60.] Had the author informed us that these
twelve plants belonged to species whose seeds enter into the nutriment of
the birds which appeared with the young wood, we could easily account for
their presence in the soil; but he says distinctly that the birds were of
insectivorous species, and it therefore seems more probable that the seeds
had been deposited when an ancient forest protected the growth of the
plants which bore them, and that they sprang up to new life when a return
of favorable conditions awaked them from a sleep of centuries. Darwin
Page 378
indeed says that the heath "had never been touched by the hand of man."
Perhaps not, after it became a heath; but what evidence is there to control
the general presumption that this heath was preceded by a forest, in whose
shade the vegetables which dropped the seeds in question might have grown
[Footnote: Writers on vegetable physiology record numerous instances
where seeds have grown after lying dormant for ages. The following cases
are mentioned by Dr. Dwight (Travels, ii., pp. 438, 430).
"The lands [in Panton, Vermont], which have here been once cultivated,
and again permitted to lie waste for several years, yield a rich and fine
growth of hickory [Carya Porcina]. Of this wood there is not, I believe, a
single tree in any original forest within fifty miles from this spot. The native
growth was here white pine, of which I did not see a single stem in a whole
grove of hickory."
The hickory is a walnut, bearing a fruit too heavy to be likely to be
carried fifty miles by birds, and besides, I believe it is not eaten by any bird
indigenous to Vermont. We have seen, however, on a former page, that birds
transport the nutmeg, which when fresh is probably as heavy as the walnut,
from one inland of the Indian archipelago to another.
"A field, about five miles from Northampton, on an eminence called Rail
Hill, was cultivated about a century ago. The native growth here, and in all
the surrounding region, was wholly oak, chestnut, etc. As the field belonged
to my grandfather, I had the best opportunity of learning its history. It
contained about five acres, in the form of an irregular parallelogram. As the
savages rendered the cultivation dangerous, it was given up. On this ground
there sprang up a grove of white pines covering the field and retaining its
figure exactly. So far as I remember, there was not in it a single oak or
chestnut tree … There was not a single pine whose seeds were, or, probably,
had for ages been, sufficiently near to have been planted on this spot. The
Perhaps not, after it became a heath; but what evidence is there to control
the general presumption that this heath was preceded by a forest, in whose
shade the vegetables which dropped the seeds in question might have grown
[Footnote: Writers on vegetable physiology record numerous instances
where seeds have grown after lying dormant for ages. The following cases
are mentioned by Dr. Dwight (Travels, ii., pp. 438, 430).
"The lands [in Panton, Vermont], which have here been once cultivated,
and again permitted to lie waste for several years, yield a rich and fine
growth of hickory [Carya Porcina]. Of this wood there is not, I believe, a
single tree in any original forest within fifty miles from this spot. The native
growth was here white pine, of which I did not see a single stem in a whole
grove of hickory."
The hickory is a walnut, bearing a fruit too heavy to be likely to be
carried fifty miles by birds, and besides, I believe it is not eaten by any bird
indigenous to Vermont. We have seen, however, on a former page, that birds
transport the nutmeg, which when fresh is probably as heavy as the walnut,
from one inland of the Indian archipelago to another.
"A field, about five miles from Northampton, on an eminence called Rail
Hill, was cultivated about a century ago. The native growth here, and in all
the surrounding region, was wholly oak, chestnut, etc. As the field belonged
to my grandfather, I had the best opportunity of learning its history. It
contained about five acres, in the form of an irregular parallelogram. As the
savages rendered the cultivation dangerous, it was given up. On this ground
there sprang up a grove of white pines covering the field and retaining its
figure exactly. So far as I remember, there was not in it a single oak or
chestnut tree … There was not a single pine whose seeds were, or, probably,
had for ages been, sufficiently near to have been planted on this spot. The
Page 379
fact that these white pines covered this field exactly, go as to preserve both
its extent and its figure, and that there were none in the neighborhood, are
decisive proofs that cultivation brought up the seeds of a former forest
within the limits of vegetation, and gave them an opportunity to germinate."
See, on the Succession of the Forest, Thoreau, Excursions, p. l35 et
seqq.]
Although, therefore, the destruction of a wood and the reclaiming of the
soil to agricultural uses suppose the death of its smaller dependent flora,
these revolutions do not exclude the possibility of its resurrection. In a
practical view of the subject, however, we must admit that when the
woodman fells a tree he sacrifices the colony of humbler growths which
had vegetated under its protection. Some wood-plants are known to possess
valuable medicinal properties, and experiment may show that the number of
these is greater than we now suppose. Few of them, however, have any
other economical value than that of furnishing a slender pasturage to cattle
allowed to roam in the woods; and even this small advantage is far more
than compensated by the mischief done to the young trees by browsing
animals. Upon the whole, the importance of this class of vegetables, as
physic or as food, is not such as to furnish a very telling popular argument
for the conservation of the forest as a necessary means of their perpetuation.
More potent remedial agents may supply their place in the materia medica,
and an acre of grass-land yields more nutriment for cattle than a range of a
hundred acres of forest. But he whose sympathies with nature have taught
him to feel that there is a fellowship between all God's creatures; to love the
brilliant ore better than the dull ingot, iodic silver and crystallized red
copper better than the shillings and the pennies forged from them by the
coiner's cunning; a venerable oak-tree than the brandy-cask whose staves
are split out from its heart-wood; a bed of anemones, hepaticas, or wood
violets than the leeks and onions which he may grow on the soil they have
its extent and its figure, and that there were none in the neighborhood, are
decisive proofs that cultivation brought up the seeds of a former forest
within the limits of vegetation, and gave them an opportunity to germinate."
See, on the Succession of the Forest, Thoreau, Excursions, p. l35 et
seqq.]
Although, therefore, the destruction of a wood and the reclaiming of the
soil to agricultural uses suppose the death of its smaller dependent flora,
these revolutions do not exclude the possibility of its resurrection. In a
practical view of the subject, however, we must admit that when the
woodman fells a tree he sacrifices the colony of humbler growths which
had vegetated under its protection. Some wood-plants are known to possess
valuable medicinal properties, and experiment may show that the number of
these is greater than we now suppose. Few of them, however, have any
other economical value than that of furnishing a slender pasturage to cattle
allowed to roam in the woods; and even this small advantage is far more
than compensated by the mischief done to the young trees by browsing
animals. Upon the whole, the importance of this class of vegetables, as
physic or as food, is not such as to furnish a very telling popular argument
for the conservation of the forest as a necessary means of their perpetuation.
More potent remedial agents may supply their place in the materia medica,
and an acre of grass-land yields more nutriment for cattle than a range of a
hundred acres of forest. But he whose sympathies with nature have taught
him to feel that there is a fellowship between all God's creatures; to love the
brilliant ore better than the dull ingot, iodic silver and crystallized red
copper better than the shillings and the pennies forged from them by the
coiner's cunning; a venerable oak-tree than the brandy-cask whose staves
are split out from its heart-wood; a bed of anemones, hepaticas, or wood
violets than the leeks and onions which he may grow on the soil they have
Page 380
enriched and in the air they made fragrant—he who has enjoyed that special
training of the heart and intellect which can be acquired only in the
unviolated sanctuaries of nature, "where man is distant, but God is near"—
will not rashly assert his right to extirpate a tribe of harmless vegetables,
barely because their products neither tickle his palate nor fill his pocket;
and his regret at the dwindling area of the forest solitude will be augmented
by the reflection that the nurselings of the woodland perish with the pines,
the oaks, and the beeches that sheltered them. [Footnote: Quaint old
Valvasor had observed the subduing influence of nature's solitudes. In
describing the lonely Canker-Thal, which, though rocky, was in his time
well wooded with "fir, larches, beeches and other trees," he says:
"Gladsomeness and beauty, which dwell in many valleys, may not be
looked for there. The journey through it is cheerless, melancholy,
wearisome, and serveth to temper and mortify orer-joyousness of thought
… In sum it is a very desert, wherein the wildness of human pride doth
grow tame."—Ehre der Crain, i., p. 186, b.]
Although, as I have said in a former chapter, birds do not frequent the
deeper recesses of the wood, yet a very large proportion of them build their
nests in trees, and find in their foliage and branches a secure retreat from
the inclemencies of the seasons and the pursuit of the reptiles and
quadrupeds which prey upon them. The borders of the forests are vocal with
song; and when the gray and dewy morning calls the creeping things of the
earth out of their night-cells, it summons from the neighboring wood
legions of their winged enemies, which swoop down upon the fields to save
man's harvests by devouring the destroying worm, and surprising the
lagging beetle in his tardy retreat to the dark cover where he lurks through
the hours of daylight.
training of the heart and intellect which can be acquired only in the
unviolated sanctuaries of nature, "where man is distant, but God is near"—
will not rashly assert his right to extirpate a tribe of harmless vegetables,
barely because their products neither tickle his palate nor fill his pocket;
and his regret at the dwindling area of the forest solitude will be augmented
by the reflection that the nurselings of the woodland perish with the pines,
the oaks, and the beeches that sheltered them. [Footnote: Quaint old
Valvasor had observed the subduing influence of nature's solitudes. In
describing the lonely Canker-Thal, which, though rocky, was in his time
well wooded with "fir, larches, beeches and other trees," he says:
"Gladsomeness and beauty, which dwell in many valleys, may not be
looked for there. The journey through it is cheerless, melancholy,
wearisome, and serveth to temper and mortify orer-joyousness of thought
… In sum it is a very desert, wherein the wildness of human pride doth
grow tame."—Ehre der Crain, i., p. 186, b.]
Although, as I have said in a former chapter, birds do not frequent the
deeper recesses of the wood, yet a very large proportion of them build their
nests in trees, and find in their foliage and branches a secure retreat from
the inclemencies of the seasons and the pursuit of the reptiles and
quadrupeds which prey upon them. The borders of the forests are vocal with
song; and when the gray and dewy morning calls the creeping things of the
earth out of their night-cells, it summons from the neighboring wood
legions of their winged enemies, which swoop down upon the fields to save
man's harvests by devouring the destroying worm, and surprising the
lagging beetle in his tardy retreat to the dark cover where he lurks through
the hours of daylight.
Page 381
The insects most injurious to the rural industry of the garden and the
ploughland do not multiply in or near the woods. The locust, which ravages
the East with its voracious armies, is bred in vast open plains which admit
the full heat of the sun to hasten the hatching of the eggs, gather no
moisture to destroy them, and harbor no bird to feed upon thelarvae.
[Footnote: Smela, in the government of Kiew, has, for some years, not
suffered at all from the locusts, which formerly came every year in vast
swarms, and the curculio, so injurious to the turnip crops, is less destructive
there than in other parts of the province. This improvement is owing partly
to the more thorough cultivation of the soil, partly to the groves which are
interspersed among the ploughlands. … When in the midst of the plains
woods shall be planted and filled with insectivorous birds, the locusts will
cease to be a plague and a terror to the farmer.—Rentzsch, Der Wald, pp.
45, 46.] It is only since the felling of the forests of Asia Minor and Cyrene
that the locust has become so fearfully destructive in those countries; and
the grasshopper, which now threatens to be almost as great a pest to the
agriculture of some North American soils, breeds in seriously injurious
numbers only where a wide extent of surface is bare of woods.
General Functions of Forests.
In the preceding pages we have seen that the electrical and chemical
action of the forest, though obscure, exercises probably a beneficial,
certainly not an injurious, influence on the composition and condition of the
atmosphere; that it serves as a protection against the diffusion of miasmatic
exhalations and malarious poisons; that it performs a most important
function as a mechanical shelter from blasting winds to grounds and crops
in the lee of it; that, as a conductor of heat, it tends to equalize the
temperature of the earth and the air; that its dead products form a mantle
over the surface, which protects the earth from excessive heat and cold; that
ploughland do not multiply in or near the woods. The locust, which ravages
the East with its voracious armies, is bred in vast open plains which admit
the full heat of the sun to hasten the hatching of the eggs, gather no
moisture to destroy them, and harbor no bird to feed upon thelarvae.
[Footnote: Smela, in the government of Kiew, has, for some years, not
suffered at all from the locusts, which formerly came every year in vast
swarms, and the curculio, so injurious to the turnip crops, is less destructive
there than in other parts of the province. This improvement is owing partly
to the more thorough cultivation of the soil, partly to the groves which are
interspersed among the ploughlands. … When in the midst of the plains
woods shall be planted and filled with insectivorous birds, the locusts will
cease to be a plague and a terror to the farmer.—Rentzsch, Der Wald, pp.
45, 46.] It is only since the felling of the forests of Asia Minor and Cyrene
that the locust has become so fearfully destructive in those countries; and
the grasshopper, which now threatens to be almost as great a pest to the
agriculture of some North American soils, breeds in seriously injurious
numbers only where a wide extent of surface is bare of woods.
General Functions of Forests.
In the preceding pages we have seen that the electrical and chemical
action of the forest, though obscure, exercises probably a beneficial,
certainly not an injurious, influence on the composition and condition of the
atmosphere; that it serves as a protection against the diffusion of miasmatic
exhalations and malarious poisons; that it performs a most important
function as a mechanical shelter from blasting winds to grounds and crops
in the lee of it; that, as a conductor of heat, it tends to equalize the
temperature of the earth and the air; that its dead products form a mantle
over the surface, which protects the earth from excessive heat and cold; that
Page 382
the evaporation from the leaves of living trees, while it cools the air around
them, diffuses through the atmosphere a medium which resists the escape of
warmth from the earth by radiation, and hence that its general effect is to
equilibrate caloric influences and moderate extremes of temperature.
We have seen, further, that the forest is equally useful as a regulator of
terrestrial and of atmospheric humidity, preventing by its shade the drying
up of the surface by parching winds and the scorching rays of the sun,
intercepting a part of the precipitation, and pouring out a vast quantity of
aqueous vapor into the atmosphere; that if it does not increase the amount
of rain, it tends to equalize its distribution both in time and in place; that it
preserves a hygrometric equilibrium in the superior strata of the earth's
surface; that it maintains and regulates the flow of springs and rivulets; that
it checks the superficial discharge of the waters of precipitation and
consequently tends to prevent the sudden rise of rivers, the violence of
floods, the formation of destructive torrents, and the abrasion of the surface
by the action of running water; that it impedes the fall of avalanches and of
rocks, and destructive slides of the superficial strata of mountains; that it is
a safeguard against the breeding of locusts, and finally that it furnishes
nutriment and shelter to many tribes of animal and of vegetable life which,
if not necessary to man's existence, are conducive to his rational enjoyment.
In fine, in well-wooded regions, and in inhabited countries where a due
proportion of soil is devoted to the growth of judiciously distributed forests,
natural destructive tendencies of all sorts are arrested or compensated, and
man, bird, beast, fish, and vegetable alike find a constant uniformity of
condition most favorable to the regular and harmonious coexistence of them
all.
General Consequences of the Destruction of the Forest.
them, diffuses through the atmosphere a medium which resists the escape of
warmth from the earth by radiation, and hence that its general effect is to
equilibrate caloric influences and moderate extremes of temperature.
We have seen, further, that the forest is equally useful as a regulator of
terrestrial and of atmospheric humidity, preventing by its shade the drying
up of the surface by parching winds and the scorching rays of the sun,
intercepting a part of the precipitation, and pouring out a vast quantity of
aqueous vapor into the atmosphere; that if it does not increase the amount
of rain, it tends to equalize its distribution both in time and in place; that it
preserves a hygrometric equilibrium in the superior strata of the earth's
surface; that it maintains and regulates the flow of springs and rivulets; that
it checks the superficial discharge of the waters of precipitation and
consequently tends to prevent the sudden rise of rivers, the violence of
floods, the formation of destructive torrents, and the abrasion of the surface
by the action of running water; that it impedes the fall of avalanches and of
rocks, and destructive slides of the superficial strata of mountains; that it is
a safeguard against the breeding of locusts, and finally that it furnishes
nutriment and shelter to many tribes of animal and of vegetable life which,
if not necessary to man's existence, are conducive to his rational enjoyment.
In fine, in well-wooded regions, and in inhabited countries where a due
proportion of soil is devoted to the growth of judiciously distributed forests,
natural destructive tendencies of all sorts are arrested or compensated, and
man, bird, beast, fish, and vegetable alike find a constant uniformity of
condition most favorable to the regular and harmonious coexistence of them
all.
General Consequences of the Destruction of the Forest.
Page 383
With the extirpation of the forest, all is changed. At one season, the earth
parts with its warmth by radiation to an open sky—receives, at another, an
immoderate heat from the unobstructed rays of the sun. Hence the climate
becomes excessive, and the soil is alternately parched by the fervors of
summer, and seared by the rigors of winter. Bleak winds sweep unresisted
over its surface, drift away the snow that sheltered it from the frost, and dry
up its scanty moisture. The precipitation becomes as irregular as the
temperature; the melting snows and vernal rains, no longer absorbed by a
loose and bibulous vegetable mould, rush over the frozen surface, and pour
down the valleys seawards, instead of filling a retentive bed of absorbent
earth, and storing up a supply of moisture to feed perennial springs. The soil
is bared of its covering of leaves, broken and loosened by the plough,
deprived of the fibrous rootlets which held it together, dried and pulverized
by sun and wind, and at last exhausted by new combinations. The face of
the earth is no longer a sponge, but a dust-heap, and the floods which the
waters of the sky pour over it hurry swiftly along its slopes, carrying in
suspension vast quantities of earthy particles which increase the abrading
power and mechanical force of the current, and, augmented by the sand and
gravel of falling banks, fill the beds of the streams, divert them into new
channels, and obstruct their outlets. The rivulets, wanting their former
regularity of supply and deprived of the protecting shade of the woods, are
heated, evaporated, and thus reduced in their summer currents, but swollen
to raging torrents in autumn and in spring. From these causes, there is a
constant degradation of the uplands, and a consequent elevation of the beds
of water-courses and of lakes by the deposition of the mineral and vegetable
matter carried down by the waters. The channels of great rivers become
unnavigable, their estuaries are choked up, and harbors which once
sheltered large navies are shoaled by dangerous sand-bars. The earth,
stripped of its vegetable glebe, grows less and less productive, and,
consequently, less able to protect itself by weaving a new network of roots
parts with its warmth by radiation to an open sky—receives, at another, an
immoderate heat from the unobstructed rays of the sun. Hence the climate
becomes excessive, and the soil is alternately parched by the fervors of
summer, and seared by the rigors of winter. Bleak winds sweep unresisted
over its surface, drift away the snow that sheltered it from the frost, and dry
up its scanty moisture. The precipitation becomes as irregular as the
temperature; the melting snows and vernal rains, no longer absorbed by a
loose and bibulous vegetable mould, rush over the frozen surface, and pour
down the valleys seawards, instead of filling a retentive bed of absorbent
earth, and storing up a supply of moisture to feed perennial springs. The soil
is bared of its covering of leaves, broken and loosened by the plough,
deprived of the fibrous rootlets which held it together, dried and pulverized
by sun and wind, and at last exhausted by new combinations. The face of
the earth is no longer a sponge, but a dust-heap, and the floods which the
waters of the sky pour over it hurry swiftly along its slopes, carrying in
suspension vast quantities of earthy particles which increase the abrading
power and mechanical force of the current, and, augmented by the sand and
gravel of falling banks, fill the beds of the streams, divert them into new
channels, and obstruct their outlets. The rivulets, wanting their former
regularity of supply and deprived of the protecting shade of the woods, are
heated, evaporated, and thus reduced in their summer currents, but swollen
to raging torrents in autumn and in spring. From these causes, there is a
constant degradation of the uplands, and a consequent elevation of the beds
of water-courses and of lakes by the deposition of the mineral and vegetable
matter carried down by the waters. The channels of great rivers become
unnavigable, their estuaries are choked up, and harbors which once
sheltered large navies are shoaled by dangerous sand-bars. The earth,
stripped of its vegetable glebe, grows less and less productive, and,
consequently, less able to protect itself by weaving a new network of roots
Page 384
to bind its particles together, a new carpeting of turf to shield it from wind
and sun and scouring rain. Gradually it becomes altogether barren. The
washing of the soil from the mountains leaves bare ridges of sterile rock,
and the rich organic mould which covered them, now swept down into the
dank low grounds, promotes a luxuriance of aquatic vegetation, that breeds
fever, and more insidious forms of mortal disease, by its decay, and thus the
earth is rendered no longer fit for the habitation of man. [Footnote: Almost
every narrative of travel in those countries which were the earliest seats of
civilization, contains evidence of the truth of these general statements, and
this evidence is presented with more or less detail in most of the special
works on the forest which I have occasion to cite. I may refer particularly to
Hohenstein, Der Wald, 1860, as full of important facts on this subject. See
also Caimi, Cenni sulla Importanza dei Boschi, for some statistics, not
readily found elsewhere, on this and other topics connected with the forest.]
To the general truth of this sad picture there are many exceptions, even in
countries of excessive climates. Some of these are due to favorable
conditions of surface, of geological structure, and of the distribution of rain;
in many others, the evil consequences of man's improvidence have not yet
been experienced, only because a sufficient time has not elapsed, since the
felling of the forest, to allow them to develop themselves. But the
vengeance of nature for the violation of her harmonies, though slow, is sure,
and the gradual deterioration of soil and climate in such exceptional regions
is as certain to result from the destruction of the woods as is any natural
effect to follow its cause.
Due Proportion of Woodland.
The proportion of woodland that ought to be permanently maintained for
its geographical and atmospheric influences varies according to the
character of soil, surface, and climate. In countries with a humid sky, or
and sun and scouring rain. Gradually it becomes altogether barren. The
washing of the soil from the mountains leaves bare ridges of sterile rock,
and the rich organic mould which covered them, now swept down into the
dank low grounds, promotes a luxuriance of aquatic vegetation, that breeds
fever, and more insidious forms of mortal disease, by its decay, and thus the
earth is rendered no longer fit for the habitation of man. [Footnote: Almost
every narrative of travel in those countries which were the earliest seats of
civilization, contains evidence of the truth of these general statements, and
this evidence is presented with more or less detail in most of the special
works on the forest which I have occasion to cite. I may refer particularly to
Hohenstein, Der Wald, 1860, as full of important facts on this subject. See
also Caimi, Cenni sulla Importanza dei Boschi, for some statistics, not
readily found elsewhere, on this and other topics connected with the forest.]
To the general truth of this sad picture there are many exceptions, even in
countries of excessive climates. Some of these are due to favorable
conditions of surface, of geological structure, and of the distribution of rain;
in many others, the evil consequences of man's improvidence have not yet
been experienced, only because a sufficient time has not elapsed, since the
felling of the forest, to allow them to develop themselves. But the
vengeance of nature for the violation of her harmonies, though slow, is sure,
and the gradual deterioration of soil and climate in such exceptional regions
is as certain to result from the destruction of the woods as is any natural
effect to follow its cause.
Due Proportion of Woodland.
The proportion of woodland that ought to be permanently maintained for
its geographical and atmospheric influences varies according to the
character of soil, surface, and climate. In countries with a humid sky, or
Page 385
moderately undulating surface and an equable temperature, a small extent
of forest, enough to serve as a mechanical screen against the action of the
wind in localities where such protection is needed, suffices. But most of the
territory occupied by civilized man is exposed, by the character of its
surface and its climate, to a physical degradation which cannot be averted
except by devoting a large amount of soil to the growth of the woods.
From an economical point of view, the question of the due proportion of
forest is not less complicated or less important than in its purely physical
aspects. Of all the raw materials which nature supplies for elaboration by
human art, wood is undoubtedly the most useful, and at the same time the
most indispensable to social progress. [Footnote: In an imaginary dialogue
in the Recepte Veritable, the author, Palissy, having expressed his
indignation at the folly of men in destroying the woods, his interlocutor
defends the policy of felling them, by citing the example of "divers bishops,
cardinals, priors, abbots, monkeries and chapters, which, by cutting their
woods, have made three profits, "the sale of the timber, the rent of the
ground, and the "good portion" they received of the grain grown by the
peasants upon it. To this argument Palissy replies: "I cannot enough detest
this thing, and I call it not an error, but a curse and a calamity to all France;
for when forests shall be cut, all arts shall cease, and they which practise
them shall be driven out to eat grass with Nebuchadnezzar and the beasts of
the field. I have divers times thought to set down in writing the arts which
shall perish when there shall be no more wood; but when I had written
down a great number, I did perceive that there could be no end of my
writing, and having diligently considered, I found there was not any which
could be followed without wood." … "And truly I could well allege to thee
a thousand reasons, but 'tis so cheap a philosophy, that the very chamber-
wenches, it they do but think, may see that without wood, it is not possible
to exercise any manner of human art or cunning."—Oeuvres de Bernard
Pallisy . Paris, 1844, p. 89.]
of forest, enough to serve as a mechanical screen against the action of the
wind in localities where such protection is needed, suffices. But most of the
territory occupied by civilized man is exposed, by the character of its
surface and its climate, to a physical degradation which cannot be averted
except by devoting a large amount of soil to the growth of the woods.
From an economical point of view, the question of the due proportion of
forest is not less complicated or less important than in its purely physical
aspects. Of all the raw materials which nature supplies for elaboration by
human art, wood is undoubtedly the most useful, and at the same time the
most indispensable to social progress. [Footnote: In an imaginary dialogue
in the Recepte Veritable, the author, Palissy, having expressed his
indignation at the folly of men in destroying the woods, his interlocutor
defends the policy of felling them, by citing the example of "divers bishops,
cardinals, priors, abbots, monkeries and chapters, which, by cutting their
woods, have made three profits, "the sale of the timber, the rent of the
ground, and the "good portion" they received of the grain grown by the
peasants upon it. To this argument Palissy replies: "I cannot enough detest
this thing, and I call it not an error, but a curse and a calamity to all France;
for when forests shall be cut, all arts shall cease, and they which practise
them shall be driven out to eat grass with Nebuchadnezzar and the beasts of
the field. I have divers times thought to set down in writing the arts which
shall perish when there shall be no more wood; but when I had written
down a great number, I did perceive that there could be no end of my
writing, and having diligently considered, I found there was not any which
could be followed without wood." … "And truly I could well allege to thee
a thousand reasons, but 'tis so cheap a philosophy, that the very chamber-
wenches, it they do but think, may see that without wood, it is not possible
to exercise any manner of human art or cunning."—Oeuvres de Bernard
Pallisy . Paris, 1844, p. 89.]
Page 386
The demand for wood, and of course the quantity of forest required to
furnish it, depend upon the supply of fuel from other sources, such as peat
and coal, upon the extent to which stone, brick, or metal can
advantageously be substituted for wood in building, upon the development
of arts and industries employing wood and other forest products as
materials, and upon the cost of obtaining them from other countries, or
upon their commercial value as articles of export.
Upon the whole, taking civilized Europe and America together, it is
probable that from twenty to twenty-five per cent. of well-wooded surface
is indispensable for the maintenance of normal physical conditions, and for
the supply of materials so essential to every branch of human industry and
every form of social life as those which compose the harvest of the woods.
There is probably no country—there are few large farms even—where at
least one-fourth of the soil is not either unfit for agricultural use, or so
unproductive that, as pasture or as ploughland, it yields less pecuniary
return than a thrifty wood. Every prairie has its sloughs where willows and
poplars would find a fitting soil, every Eastern farm its rocky nooks and its
barren hillsides suited to the growth of some species from our rich forest
flora, and everywhere belts of trees might advantageously be planted along
the roadsides and the boundaries and dividing fences. In most cases, it will
be found that trees may be made to grow well where cultivated crops will
not repay the outlay of tillage, and it is a very plain dictate of sound
economy that if trees produce a better profit than the same ground would
return if devoted to grass or grain, the wood should be substituted for the
field.
Woodland in European Countries.
In 1862, Rentzsch calculated the proportions of woodland in different
European countries as follows: [Footnote: Der Wald, pp. 123, 124.]
furnish it, depend upon the supply of fuel from other sources, such as peat
and coal, upon the extent to which stone, brick, or metal can
advantageously be substituted for wood in building, upon the development
of arts and industries employing wood and other forest products as
materials, and upon the cost of obtaining them from other countries, or
upon their commercial value as articles of export.
Upon the whole, taking civilized Europe and America together, it is
probable that from twenty to twenty-five per cent. of well-wooded surface
is indispensable for the maintenance of normal physical conditions, and for
the supply of materials so essential to every branch of human industry and
every form of social life as those which compose the harvest of the woods.
There is probably no country—there are few large farms even—where at
least one-fourth of the soil is not either unfit for agricultural use, or so
unproductive that, as pasture or as ploughland, it yields less pecuniary
return than a thrifty wood. Every prairie has its sloughs where willows and
poplars would find a fitting soil, every Eastern farm its rocky nooks and its
barren hillsides suited to the growth of some species from our rich forest
flora, and everywhere belts of trees might advantageously be planted along
the roadsides and the boundaries and dividing fences. In most cases, it will
be found that trees may be made to grow well where cultivated crops will
not repay the outlay of tillage, and it is a very plain dictate of sound
economy that if trees produce a better profit than the same ground would
return if devoted to grass or grain, the wood should be substituted for the
field.
Woodland in European Countries.
In 1862, Rentzsch calculated the proportions of woodland in different
European countries as follows: [Footnote: Der Wald, pp. 123, 124.]
Page 387
Norway……………………………. 66 per cent.
Sweden……………………………. 60 "
Russia……………………………. 30.00 "
Germany…………………………… 26.58 "
Belgium…………………………… 18.52 "
France……………………………. 16.79 "
Switzerland……………………….. 15 "
Sardinia…………………………… 12.29
Neapolitan States…………………… 9.43 "
Holland……………………………. 7.10 "
Spain……………………………… 5.52 "
Denmark……………………………. 5.50 "
Great Britain………………………. 5 "
Portugal…………………………… 4.40 "
The large proportion of woodland in Norway and Sweden is in a great
measure to be ascribed to the mountainous character of the surface, which
renders the construction of roads difficult and expensive, and hence the
forests are comparatively inaccessible, and transportation is too costly to
tempt the inhabitants to sacrifice their woods for the sake of supplying
distant markets.
The industries which employ wood as a material have only lately been
much developed in these countries, and though the climate requires the
consumption of much wood as a fuel, the population is not numerous
enough to create, for this purpose, a demand exceeding the annually
produced supply, or to need any great extension of cleared ground for
agricultural purposes. Besides this, in many places peat is generally
employed as domestic fuel. Hence, though Norway has long exported a
considerable quantity of lumber, [Footnote: Railway-ties, or, as they are
called in England, sleepers, are largely exported from Norway to India, and
Sweden……………………………. 60 "
Russia……………………………. 30.00 "
Germany…………………………… 26.58 "
Belgium…………………………… 18.52 "
France……………………………. 16.79 "
Switzerland……………………….. 15 "
Sardinia…………………………… 12.29
Neapolitan States…………………… 9.43 "
Holland……………………………. 7.10 "
Spain……………………………… 5.52 "
Denmark……………………………. 5.50 "
Great Britain………………………. 5 "
Portugal…………………………… 4.40 "
The large proportion of woodland in Norway and Sweden is in a great
measure to be ascribed to the mountainous character of the surface, which
renders the construction of roads difficult and expensive, and hence the
forests are comparatively inaccessible, and transportation is too costly to
tempt the inhabitants to sacrifice their woods for the sake of supplying
distant markets.
The industries which employ wood as a material have only lately been
much developed in these countries, and though the climate requires the
consumption of much wood as a fuel, the population is not numerous
enough to create, for this purpose, a demand exceeding the annually
produced supply, or to need any great extension of cleared ground for
agricultural purposes. Besides this, in many places peat is generally
employed as domestic fuel. Hence, though Norway has long exported a
considerable quantity of lumber, [Footnote: Railway-ties, or, as they are
called in England, sleepers, are largely exported from Norway to India, and
Page 388
sold at Calcutta at a lower price than timber of equal quality can be
obtained from the native woods.—Reports on Forest Conservancy, vol. i.,
pt. ii., p. 1533.
From 1861 to 1870 Norway exported annually, on the average, more than
60,000,000 cubic feet of lumber.—Wulfsberg, Norges Velstandskilder.
Christiania, 1872.] and the iron and copper works of Sweden consume
charcoal very largely, the forests have not diminished rapidly enough to
produce very sensible climatic or even economic evils.
At the opposite end of the scale we find Holland, Denmark, Great
Britain, Spain, and Portugal. In the three first-named countries a cold and
humid climate renders the almost constant maintenance of domestic fires a
necessity, while in Great Britain especially the demand of the various
industries which depend on wood as a material, or on mechanical power
derived from heat, are very great. Coal and peat serve as a combustible
instead of wood in them all, and England imports an immense quantity of
timber from her foreign possessions. Fortunately, the character of soil,
surface, and climate renders the forest of less importance as a geographical
agent in these northern regions than in Spain and Portugal, where all
physical conditions concur to make a large extent of forest an almost
indispensable means of industrial progress and social advancement.
Rentzsch, in fact, ascribes the political decadence of Spain almost wholly
to the destruction of the forest. "Spain," observes he, "seemed destined by
her position to hold dominion over the world, and this in fact she once
possessed. But she has lost her political ascendancy, because, during the
feeble administration of the successors of Philip II., her exhausted treasury
could not furnish the means of creating new fleets, the destruction of the
woods having raised the price of timber above the means of the state."
[Footnote: Der Wald, p. 63. Antonio Ponz (Viage de Espana, i., prologo, p.
obtained from the native woods.—Reports on Forest Conservancy, vol. i.,
pt. ii., p. 1533.
From 1861 to 1870 Norway exported annually, on the average, more than
60,000,000 cubic feet of lumber.—Wulfsberg, Norges Velstandskilder.
Christiania, 1872.] and the iron and copper works of Sweden consume
charcoal very largely, the forests have not diminished rapidly enough to
produce very sensible climatic or even economic evils.
At the opposite end of the scale we find Holland, Denmark, Great
Britain, Spain, and Portugal. In the three first-named countries a cold and
humid climate renders the almost constant maintenance of domestic fires a
necessity, while in Great Britain especially the demand of the various
industries which depend on wood as a material, or on mechanical power
derived from heat, are very great. Coal and peat serve as a combustible
instead of wood in them all, and England imports an immense quantity of
timber from her foreign possessions. Fortunately, the character of soil,
surface, and climate renders the forest of less importance as a geographical
agent in these northern regions than in Spain and Portugal, where all
physical conditions concur to make a large extent of forest an almost
indispensable means of industrial progress and social advancement.
Rentzsch, in fact, ascribes the political decadence of Spain almost wholly
to the destruction of the forest. "Spain," observes he, "seemed destined by
her position to hold dominion over the world, and this in fact she once
possessed. But she has lost her political ascendancy, because, during the
feeble administration of the successors of Philip II., her exhausted treasury
could not furnish the means of creating new fleets, the destruction of the
woods having raised the price of timber above the means of the state."
[Footnote: Der Wald, p. 63. Antonio Ponz (Viage de Espana, i., prologo, p.
Page 389
lxiii.), says: "Nor would this be so great an evil, were not some of them
declaimers against TREES, thereby proclaiming themselves, in some sort,
enemies of the works of God, who gave us the leafy abode of Paradise to
dwell in, where we should be even now sojourning, but for the first sin,
which expelled us from it."
I do not know at what period the two Castiles were bared of their woods,
but the Spaniard's proverbial "hatred of a tree" is of long standing. Herrera
combats this foolish prejudice; and Ponz, in the prologue to the ninth
volume of his journey, says that many carried it so far as wantonly to
destroy the shade and ornamental trees planted by the municipal authorities.
"Trees," they contended, and still believe, "breed birds, and birds eat up the
grain." Our author argues against the supposition of the "breeding of birds
by trees," which, he says, is as absurd as to believe that an elm-tree can
yield pears; and he charitably suggests that the expression is, perhaps, a
maniere de dire, a popular phrase, signifying simply that trees harbor birds.]
On the other hand, the same writer argues that the wealth and prosperity of
modern England are in great part due to the supply of lumber, as well as of
other material for ship-building, which she imports from her colonies and
other countries with which she maintains commercial relations.
Forests of Great Britain.
The proportion of forest is very small in Great Britain, where, as I have
said, on the one hand, a prodigious industrial activity requires a vast supply
of ligneous material, but where, on the other, the abundance of coal, which
furnishes a sufficiency of fuel, the facility of importation of timber from
abroad, and the conditions of climate and surface combine to reduce the
necessary quantity of woodland to its lowest expression.
declaimers against TREES, thereby proclaiming themselves, in some sort,
enemies of the works of God, who gave us the leafy abode of Paradise to
dwell in, where we should be even now sojourning, but for the first sin,
which expelled us from it."
I do not know at what period the two Castiles were bared of their woods,
but the Spaniard's proverbial "hatred of a tree" is of long standing. Herrera
combats this foolish prejudice; and Ponz, in the prologue to the ninth
volume of his journey, says that many carried it so far as wantonly to
destroy the shade and ornamental trees planted by the municipal authorities.
"Trees," they contended, and still believe, "breed birds, and birds eat up the
grain." Our author argues against the supposition of the "breeding of birds
by trees," which, he says, is as absurd as to believe that an elm-tree can
yield pears; and he charitably suggests that the expression is, perhaps, a
maniere de dire, a popular phrase, signifying simply that trees harbor birds.]
On the other hand, the same writer argues that the wealth and prosperity of
modern England are in great part due to the supply of lumber, as well as of
other material for ship-building, which she imports from her colonies and
other countries with which she maintains commercial relations.
Forests of Great Britain.
The proportion of forest is very small in Great Britain, where, as I have
said, on the one hand, a prodigious industrial activity requires a vast supply
of ligneous material, but where, on the other, the abundance of coal, which
furnishes a sufficiency of fuel, the facility of importation of timber from
abroad, and the conditions of climate and surface combine to reduce the
necessary quantity of woodland to its lowest expression.
Page 390
With the exception of Russia, Denmark, and parts of Germany, no
European countries can so well dispense with the forests, in their capacity
of conservative influences, as England and Ireland. Their insular position
and latitude secure an abundance of atmospheric moisture; the general
inclination of surface is not such as to expose it to special injury from
torrents, and it is probable that the most important climatic action exercised
by the forest in these portions of the British empire, is in its character of a
mechanical screen against the effects of wind. The due proportion of
woodland in England and Ireland is, therefore, a question not of
geographical, but almost purely of economical, expediency, to be decided
by the comparative direct pecuniary return from forest-growth, pasturage,
and ploughland.
Contrivances for economizing fuel came later into use in the British
Islands than on the Continent. Before the introduction of a system of
drainage, the soil, like the sky, was, in general, charged with humidity; its
natural condition was unfavorable for the construction and maintenance of
substantial common roads, and the transportation of so heavy a material as
coal, by land, from the remote counties where alone it was mined in the
Middle Ages, was costly and difficult. For all these reasons, the
consumption of wood was large, and apprehensions of the exhaustion of the
forests were excited at an early period. Legislation there, as elsewhere,
proved ineffectual to protect them, and many authors of the sixteenth
century express fears of serious evils from the wasteful economy of the
people in this respect. Harrison, in his curious chapter "Of Woods and
Marishes" in Holinshed's compilation, complains of the rapid decrease of
the forests, and adds: "Howbeit thus much I dare affirme, that if woods go
so fast to decaie in the next hundred yeere of Grace, as they haue doone and
are like to doo in this, . . . it is to be feared that the fennie bote, broome,
turfe, gall, heath, firze, brakes, whinnes, ling, dies, hassacks, flags, straw,
sedge, reed, rush, and also seacole, will be good merchandize euen in the
European countries can so well dispense with the forests, in their capacity
of conservative influences, as England and Ireland. Their insular position
and latitude secure an abundance of atmospheric moisture; the general
inclination of surface is not such as to expose it to special injury from
torrents, and it is probable that the most important climatic action exercised
by the forest in these portions of the British empire, is in its character of a
mechanical screen against the effects of wind. The due proportion of
woodland in England and Ireland is, therefore, a question not of
geographical, but almost purely of economical, expediency, to be decided
by the comparative direct pecuniary return from forest-growth, pasturage,
and ploughland.
Contrivances for economizing fuel came later into use in the British
Islands than on the Continent. Before the introduction of a system of
drainage, the soil, like the sky, was, in general, charged with humidity; its
natural condition was unfavorable for the construction and maintenance of
substantial common roads, and the transportation of so heavy a material as
coal, by land, from the remote counties where alone it was mined in the
Middle Ages, was costly and difficult. For all these reasons, the
consumption of wood was large, and apprehensions of the exhaustion of the
forests were excited at an early period. Legislation there, as elsewhere,
proved ineffectual to protect them, and many authors of the sixteenth
century express fears of serious evils from the wasteful economy of the
people in this respect. Harrison, in his curious chapter "Of Woods and
Marishes" in Holinshed's compilation, complains of the rapid decrease of
the forests, and adds: "Howbeit thus much I dare affirme, that if woods go
so fast to decaie in the next hundred yeere of Grace, as they haue doone and
are like to doo in this, . . . it is to be feared that the fennie bote, broome,
turfe, gall, heath, firze, brakes, whinnes, ling, dies, hassacks, flags, straw,
sedge, reed, rush, and also seacole, will be good merchandize euen in the
Page 391
citie of London, whereunto some of them euen now haue gotten readie
passage, and taken up their innes in the greatest merchants' parlours . . . . I
would wish that I might liue no longer than to see foure things in this land
reformed, that is: the want of discipline in the church: the couetous dealing
of most of our merchants in the preferment of the commodities of other
countries, and hinderance of their owne: the holding of faires and markets
vpon the sundaie to be abolished and referred to the wednesdaies: and that
euerie man, in whatsoeuer part of the champaine soile enioieth fortie acres
of land, and vpwards, after that rate, either by free deed, copie hold, or fee
farme, might plant one acre of wood, or sowe the same with oke mast,
hasell, beech, and sufficient prouision be made that it may be cherished and
kept. But I feare me that I should then liue too long, and so long, that I
should either be wearie of the world, or the world of me." [Footnote:
Holinshed, reprint of 1807, i., pp. 357, 358. It is evident from this passage,
and from another on page 397 of the same volume, that, though seacoal was
largely exported to the Continent, it had not yet come into general use in
England. It is a question of much interest, when mineral coal was first
employed in England for fuel. I can find no evidence that it was used as a
combustible until more than a century after the Norman conquest. It has
been said that it was known to the Anglo-Saxon population, but I am
acquainted with no passage in the literature of that people which proves
this. The dictionaries explain the Anglo-Saxon word grofa by sea-coal. I
have met with this word in no Anglo-Saxon work, except in the Chronicle,
A.D. 852, from a manuscript certainly not older than the 12th century, and
in two citations from Anglo-Saxon charters, one published by Kemble in
Codex Diplomaticus, the other by Thorpe in Diplomatarium Anglicum, in
all which passages it more probably means peat than mineral coal.
According to Way, Promptorium Parrulorum, p. 506, note, the Catholicon
Anglicanum has "A turfe grafte, turbarium." Grafte is here evidently the
same word as the A.-S. grafa, and the Danish Torvegraf, a turf-pit, confirms
passage, and taken up their innes in the greatest merchants' parlours . . . . I
would wish that I might liue no longer than to see foure things in this land
reformed, that is: the want of discipline in the church: the couetous dealing
of most of our merchants in the preferment of the commodities of other
countries, and hinderance of their owne: the holding of faires and markets
vpon the sundaie to be abolished and referred to the wednesdaies: and that
euerie man, in whatsoeuer part of the champaine soile enioieth fortie acres
of land, and vpwards, after that rate, either by free deed, copie hold, or fee
farme, might plant one acre of wood, or sowe the same with oke mast,
hasell, beech, and sufficient prouision be made that it may be cherished and
kept. But I feare me that I should then liue too long, and so long, that I
should either be wearie of the world, or the world of me." [Footnote:
Holinshed, reprint of 1807, i., pp. 357, 358. It is evident from this passage,
and from another on page 397 of the same volume, that, though seacoal was
largely exported to the Continent, it had not yet come into general use in
England. It is a question of much interest, when mineral coal was first
employed in England for fuel. I can find no evidence that it was used as a
combustible until more than a century after the Norman conquest. It has
been said that it was known to the Anglo-Saxon population, but I am
acquainted with no passage in the literature of that people which proves
this. The dictionaries explain the Anglo-Saxon word grofa by sea-coal. I
have met with this word in no Anglo-Saxon work, except in the Chronicle,
A.D. 852, from a manuscript certainly not older than the 12th century, and
in two citations from Anglo-Saxon charters, one published by Kemble in
Codex Diplomaticus, the other by Thorpe in Diplomatarium Anglicum, in
all which passages it more probably means peat than mineral coal.
According to Way, Promptorium Parrulorum, p. 506, note, the Catholicon
Anglicanum has "A turfe grafte, turbarium." Grafte is here evidently the
same word as the A.-S. grafa, and the Danish Torvegraf, a turf-pit, confirms
Page 392
this opinion. Coal is not mentioned in King Alfred's Bede, in Neckam, in
Glanville or in Robert of Gloucester, though the two latter writers speak of
the allied mineral, jet, and are very full in their enumeration of the mineral
productions of the island. In a Latin poem ascribed to Giraldus Cambrensis,
who died after the year 1220, but found also in the manuesripts of Walter
Mapes (see Camden Society edition, pp. 131 and 350), and introduced into
Higden's Polychronicon (London, 1865, pp. 398, 399), carbo sub terra
cortice, which can mean nothing but pit-coal, is enumerated among the
natural commodities of England. Some of the translations of the 13th and
14th century render carbo by cool or col, some by gold, and some omit this
line, as well as others unintelligible to the translators. Hence, although
Giraldus was acquainted with coal, it certainly was not generally known to
English writers until at least a century after the time of that author.
The earliest mediaeval notice of mineral coal I have met with is in a
passage cited by Ducange from a document of the year 1198, and it is an
etymological observation of some interest, that carbones ferrei, as sea-coal
is called in the document, are said by Ducange to have been known in
France by the popular name of hulla, a word evidently identical with the
modern French houille and the Cornish Huel, which in the form wheal is an
element in the name of many mining localities.
England was anciently remarkable for its forests, but Caesar says it
wanted the fagus and the abies. There can be no doubt that fagus means the
beech, which, as the remains in the Danish peat-mosses show, is a tree of
late introduction into Denmark, where it succeeded the fir, a tree not now
native to that country. The succession of forest crops seems to have been the
same in England; for Harrison, p. 359, speaks of the "great store of firre"
found lying "at their whole lengths" in the "fens and marises" of Lancashire
and other counties, where not even bushes grew in his time. We cannot be
sure what species of evergreen Caesar intended by abies. The popular
Glanville or in Robert of Gloucester, though the two latter writers speak of
the allied mineral, jet, and are very full in their enumeration of the mineral
productions of the island. In a Latin poem ascribed to Giraldus Cambrensis,
who died after the year 1220, but found also in the manuesripts of Walter
Mapes (see Camden Society edition, pp. 131 and 350), and introduced into
Higden's Polychronicon (London, 1865, pp. 398, 399), carbo sub terra
cortice, which can mean nothing but pit-coal, is enumerated among the
natural commodities of England. Some of the translations of the 13th and
14th century render carbo by cool or col, some by gold, and some omit this
line, as well as others unintelligible to the translators. Hence, although
Giraldus was acquainted with coal, it certainly was not generally known to
English writers until at least a century after the time of that author.
The earliest mediaeval notice of mineral coal I have met with is in a
passage cited by Ducange from a document of the year 1198, and it is an
etymological observation of some interest, that carbones ferrei, as sea-coal
is called in the document, are said by Ducange to have been known in
France by the popular name of hulla, a word evidently identical with the
modern French houille and the Cornish Huel, which in the form wheal is an
element in the name of many mining localities.
England was anciently remarkable for its forests, but Caesar says it
wanted the fagus and the abies. There can be no doubt that fagus means the
beech, which, as the remains in the Danish peat-mosses show, is a tree of
late introduction into Denmark, where it succeeded the fir, a tree not now
native to that country. The succession of forest crops seems to have been the
same in England; for Harrison, p. 359, speaks of the "great store of firre"
found lying "at their whole lengths" in the "fens and marises" of Lancashire
and other counties, where not even bushes grew in his time. We cannot be
sure what species of evergreen Caesar intended by abies. The popular
Page 393
designations of spike-leaved trees are always more vague and uncertain in
their application than those of broad-leaved trees. PINUS, PINE, has been
very loosely employed even in botanical nomenclature, and KIEFER,
FICHTE, and TANNE are often confounded in German.—Rossmassler, Der
Wald, pp. 256, 289, 324. A similar confusion in the names of this family of
trees exists in India. Dr. Cleghorn, Inspector-General of the Indian Forests,
informs us in his official Circular No. 2, that the name of deodar is applied
in some provinces to a cypress, in some to a cedar, and in others to a
juniper. If it were certain that the abies of Caesar was the fir formerly and
still found in peat-mosses, and that he was right in denying the existence of
the beech in England in his time, the observation would be very important,
because it would fix a date at which the fir had become extinct, and the
beech had not yet appeared in the island.
The English oak, though strong and durable, was not considered
generally suitable for finer work in the sixteenth century. There were,
however, exceptions. "Of all in Essex," observes Harrison, Holinshed, i., p.
357, "that growing in Bardfield parke is the finest for ioiners craft; for
oftentimes haue I seene of their workes made of that oke so fine and faire,
as most of the wainescot that is brought hither out of Danske [Danzig]; for
our wainescot is not made in England. Yet diuerse haue assaied to deale
with our okes to that end, but not with so good successe as they haue hoped,
bicause the ab or iuice will not so soone be removed and cleane drawne out,
which some attribute to want of time in the salt water." This passage is also
of interest as showing that soaking in salt-water, as a mode of seasoning,
was practised in Harrison's time.
But the importation of wainscot, or boards for ceiling, panelling, and
otherwise finishing rooms, which was generally of oak, commenced at least
three centuries before the time of Harrison. On page 204 of the Liber Albus
mention is made of "squared oak timber," brought in from the country by
their application than those of broad-leaved trees. PINUS, PINE, has been
very loosely employed even in botanical nomenclature, and KIEFER,
FICHTE, and TANNE are often confounded in German.—Rossmassler, Der
Wald, pp. 256, 289, 324. A similar confusion in the names of this family of
trees exists in India. Dr. Cleghorn, Inspector-General of the Indian Forests,
informs us in his official Circular No. 2, that the name of deodar is applied
in some provinces to a cypress, in some to a cedar, and in others to a
juniper. If it were certain that the abies of Caesar was the fir formerly and
still found in peat-mosses, and that he was right in denying the existence of
the beech in England in his time, the observation would be very important,
because it would fix a date at which the fir had become extinct, and the
beech had not yet appeared in the island.
The English oak, though strong and durable, was not considered
generally suitable for finer work in the sixteenth century. There were,
however, exceptions. "Of all in Essex," observes Harrison, Holinshed, i., p.
357, "that growing in Bardfield parke is the finest for ioiners craft; for
oftentimes haue I seene of their workes made of that oke so fine and faire,
as most of the wainescot that is brought hither out of Danske [Danzig]; for
our wainescot is not made in England. Yet diuerse haue assaied to deale
with our okes to that end, but not with so good successe as they haue hoped,
bicause the ab or iuice will not so soone be removed and cleane drawne out,
which some attribute to want of time in the salt water." This passage is also
of interest as showing that soaking in salt-water, as a mode of seasoning,
was practised in Harrison's time.
But the importation of wainscot, or boards for ceiling, panelling, and
otherwise finishing rooms, which was generally of oak, commenced at least
three centuries before the time of Harrison. On page 204 of the Liber Albus
mention is made of "squared oak timber," brought in from the country by
Page 394
carts, and of course of domestic growth, as free of city duty or octroi, and of
"planks of oak" coming in in the same way as paying one plank a cart-load.
But in the chapter on the "Customs of Billyngesgate," pp. 208, 209, relating
to goods imported from foreign countries, an import duty of one halfpenny
is imposed on every hundred of boards called "weynscotte"—a term
formerly applied only to oak—and of one penny on every hundred of
boards called "Rygholt." The editor explains "Rygholt" as "wood of Riga."
This was doubtless pine or fir. The year in which these provisions were
made does not appear, but they belong to the reign of Henry III.]
Evelyn's "Silva," the first edition of which appeared in 1664, rendered an
extremely important service to the cause of the woods, and there is no doubt
that the ornamental plantations in which England far surpasses all other
countries, are, in some measure, the fruit of Evelyn's enthusiasm. In
England, however, arboriculture, the planting and nursing of single trees,
has, until comparatively recent times, been better understood than
sylviculture, the sowing and training of the forest. But this latter branch of
rural improvement now receives great attention from private individuals,
though, so far as I know, not from the National Government, except in the
East Indian provinces, where the forestal department has assumed great
importance. [Footnote: The improvidence of the population under the native
and early foreign governments has produced great devastations in the
forests of the British East Indian provinces, and the demands of the railways
for fuel and timber have greatly augmented the consumption of lumber, and
of course contributed to the destruction of the woods. The forests of British
India are now, and for several years have been, under the control of an
efficient governmental organization, with great advantage both to the
government and to the general private interests of the people.
The official Reports on Forest Conservancy from May, 1862, to August,
1871, in 4 vols. folio, contain much statistical and practical information on
"planks of oak" coming in in the same way as paying one plank a cart-load.
But in the chapter on the "Customs of Billyngesgate," pp. 208, 209, relating
to goods imported from foreign countries, an import duty of one halfpenny
is imposed on every hundred of boards called "weynscotte"—a term
formerly applied only to oak—and of one penny on every hundred of
boards called "Rygholt." The editor explains "Rygholt" as "wood of Riga."
This was doubtless pine or fir. The year in which these provisions were
made does not appear, but they belong to the reign of Henry III.]
Evelyn's "Silva," the first edition of which appeared in 1664, rendered an
extremely important service to the cause of the woods, and there is no doubt
that the ornamental plantations in which England far surpasses all other
countries, are, in some measure, the fruit of Evelyn's enthusiasm. In
England, however, arboriculture, the planting and nursing of single trees,
has, until comparatively recent times, been better understood than
sylviculture, the sowing and training of the forest. But this latter branch of
rural improvement now receives great attention from private individuals,
though, so far as I know, not from the National Government, except in the
East Indian provinces, where the forestal department has assumed great
importance. [Footnote: The improvidence of the population under the native
and early foreign governments has produced great devastations in the
forests of the British East Indian provinces, and the demands of the railways
for fuel and timber have greatly augmented the consumption of lumber, and
of course contributed to the destruction of the woods. The forests of British
India are now, and for several years have been, under the control of an
efficient governmental organization, with great advantage both to the
government and to the general private interests of the people.
The official Reports on Forest Conservancy from May, 1862, to August,
1871, in 4 vols. folio, contain much statistical and practical information on
Page 395
all subjects connected with the administration of the forest.]
In fact, England is, I believe, the only European country where private
enterprise has pursued sylviculture on a really great scale, though admirable
examples have been set in many others. In England the law of
primogeniture, and other institutions and national customs which tend to
keep large estates long undivided and in the same line of inheritance, the
wealth of the landholders, the special adaptation of the climate to the
growth of forest-trees, and the difficulty of finding safe and profitable
investments of capital, combine to afford encouragements for the plantation
of forests, which scarcely exist elsewhere in the same degree.
In Scotland, where the country is for the most part broken and
mountainous, the general destruction of the forests has been attended with
very serious evils, and it is in Scotland that many of the most extensive
British forest plantations have now been formed. But although the
inclination of surface in Scotland is rapid, the geological constitution of the
soil is not of a character to promote such destructive degradation by running
water as in Southern France, and it has not to contend with the parching
droughts by which the devastations of the torrents are rendered more
injurious in those provinces.
It is difficult to understand how either law or public opinion, in a country
occupied by a dense and intelligent population, and, comparatively
speaking, with an infertile soil, can tolerate the continued withdrawal of a
great portion of the territory from the cultivation of trees and from other
kinds of rural economy, merely to allow wealthy individuals to amuse
themselves with field-sports. In Scotland, 2,000,000 acres, as well suited to
the growth of forests and for pasture as is the soil generally, are withheld
from agriculture, that they may be given up to herds of deer protected by
the game laws. A single nobleman, for example, thus appropriates for his
In fact, England is, I believe, the only European country where private
enterprise has pursued sylviculture on a really great scale, though admirable
examples have been set in many others. In England the law of
primogeniture, and other institutions and national customs which tend to
keep large estates long undivided and in the same line of inheritance, the
wealth of the landholders, the special adaptation of the climate to the
growth of forest-trees, and the difficulty of finding safe and profitable
investments of capital, combine to afford encouragements for the plantation
of forests, which scarcely exist elsewhere in the same degree.
In Scotland, where the country is for the most part broken and
mountainous, the general destruction of the forests has been attended with
very serious evils, and it is in Scotland that many of the most extensive
British forest plantations have now been formed. But although the
inclination of surface in Scotland is rapid, the geological constitution of the
soil is not of a character to promote such destructive degradation by running
water as in Southern France, and it has not to contend with the parching
droughts by which the devastations of the torrents are rendered more
injurious in those provinces.
It is difficult to understand how either law or public opinion, in a country
occupied by a dense and intelligent population, and, comparatively
speaking, with an infertile soil, can tolerate the continued withdrawal of a
great portion of the territory from the cultivation of trees and from other
kinds of rural economy, merely to allow wealthy individuals to amuse
themselves with field-sports. In Scotland, 2,000,000 acres, as well suited to
the growth of forests and for pasture as is the soil generally, are withheld
from agriculture, that they may be given up to herds of deer protected by
the game laws. A single nobleman, for example, thus appropriates for his
Page 396
own pleasures not less than 100,000 acres. [Footnote: Robertson, Our Deer
Forests. London, 1867.] In this way one-tenth of all the land of Scotland is
rendered valueless in an economical point of view—for the returns from the
sale of the venison and other game scarcely suffice to pay the game-keepers
and other incidental expenses—and in these so-called FORESTS there
grows neither building timber nor fire-wood worth the cutting, as the
animals destroy the young shoots.
Forests of France.
The preservation of the woods was one of the wise measures
recommended to France by Sully, in the time of Henry IV., but the advice
was little heeded, and the destruction of the forests went on with such
alarming rapidity, that, two generations later, Colbert uttered the prediction:
"France will perish for want of wood." Still, the extent of wooded soil was
very great, and the evils attending its diminution were not so sensibly felt,
that either the government or public opinion saw the necessity of
authoritative interference, and in 1750 Mirabeau estimated the remaining
forests of the kingdom at seventeen millions of hectares [42,000,000 acres].
In 1860 they were reduced to eight millions [19,769,000 acres], or at the
rate of 82,000 hectares [202,600 acres] per year. Troy, from whose valuable
pamphlet, Etude sur le Reboisement des Montagnes, I take these statistical
details, supposes that Mirabeau's statement may have been an extravagant
one, but it still remains certain that the waste has been enormous; for it is
known that, in some departments, that of Ariege, for instance, clearing has
gone on during the last half-century at the rate of three thousand acres a
year, and in all parts of the empire trees have been felled faster than they
have grown. [Footnote: Among the indirect proofs of the comparatively
recent existence of extensive forests in France, may be mentioned the fact
that wolves were abundant, not very long since, in parts of the empire
Forests. London, 1867.] In this way one-tenth of all the land of Scotland is
rendered valueless in an economical point of view—for the returns from the
sale of the venison and other game scarcely suffice to pay the game-keepers
and other incidental expenses—and in these so-called FORESTS there
grows neither building timber nor fire-wood worth the cutting, as the
animals destroy the young shoots.
Forests of France.
The preservation of the woods was one of the wise measures
recommended to France by Sully, in the time of Henry IV., but the advice
was little heeded, and the destruction of the forests went on with such
alarming rapidity, that, two generations later, Colbert uttered the prediction:
"France will perish for want of wood." Still, the extent of wooded soil was
very great, and the evils attending its diminution were not so sensibly felt,
that either the government or public opinion saw the necessity of
authoritative interference, and in 1750 Mirabeau estimated the remaining
forests of the kingdom at seventeen millions of hectares [42,000,000 acres].
In 1860 they were reduced to eight millions [19,769,000 acres], or at the
rate of 82,000 hectares [202,600 acres] per year. Troy, from whose valuable
pamphlet, Etude sur le Reboisement des Montagnes, I take these statistical
details, supposes that Mirabeau's statement may have been an extravagant
one, but it still remains certain that the waste has been enormous; for it is
known that, in some departments, that of Ariege, for instance, clearing has
gone on during the last half-century at the rate of three thousand acres a
year, and in all parts of the empire trees have been felled faster than they
have grown. [Footnote: Among the indirect proofs of the comparatively
recent existence of extensive forests in France, may be mentioned the fact
that wolves were abundant, not very long since, in parts of the empire
Page 397
where there are now neither wolves nor woods to shelter them. Arthur
Young more than once speaks of the "innumerable multitudes" of these
animals which infested France in 1789, and George Sand states, in the
Histoire de ma Vie, that some years after the restoration of the Bourbons,
they chased travellers on horseback in the southern provinces, and literally
knocked at the doors of her father-in-law's country seat. Eugenie de Guerin,
writing from Rayssac in Languedoc in 1831 speaks of hearing the wolves
fighting with dogs in the night under her very windows. Lettres, 2d ed., p.
6.
There seems to have been a tendency to excessive clearing in Central and
Western, earlier than in South-eastern, France. Bernard Palissy, in the
Recepte Veritable, first printed in 1563, thus complains: "When I consider
the value of the least clump of trees, or even of thorns, I much marvel at the
great ignorance of men, who, as it seemeth, do nowadays study only to
break down, fell, and waste the fair forests which their forefathers did guard
so choicely. I would think no evil of them for cutting down the woods, did
they but replant again some part of them; but they care nought for the time
to come, neither reck they of the great damage they do to their children
which shall come after them."—Oeuvres Completes de Bernard Pallisy,
1844, p. 88.] The total area of France in Mirabeau's time, excluding Savoy,
but including Alsace and Lorraine, was about one hundred and thirty-one
millions of acres. The extent of forest supposed by Mirabeau would be
about thirty-two per cent. of the whole territory. In a country and a climate
where the conservative influences of the forest are so necessary as in
France, trees must cover a large surface and be grouped in large masses, in
order to discharge to the best advantage the various functions assigned to
them by nature. The consumption of wood is rapidly increasing in that
empire, and a large part of its territory is mountainous, sterile, and
otherwise such in character or situation that it can be more profitably
devoted to the growth of wood than to any agricultural use. Hence it is
Young more than once speaks of the "innumerable multitudes" of these
animals which infested France in 1789, and George Sand states, in the
Histoire de ma Vie, that some years after the restoration of the Bourbons,
they chased travellers on horseback in the southern provinces, and literally
knocked at the doors of her father-in-law's country seat. Eugenie de Guerin,
writing from Rayssac in Languedoc in 1831 speaks of hearing the wolves
fighting with dogs in the night under her very windows. Lettres, 2d ed., p.
6.
There seems to have been a tendency to excessive clearing in Central and
Western, earlier than in South-eastern, France. Bernard Palissy, in the
Recepte Veritable, first printed in 1563, thus complains: "When I consider
the value of the least clump of trees, or even of thorns, I much marvel at the
great ignorance of men, who, as it seemeth, do nowadays study only to
break down, fell, and waste the fair forests which their forefathers did guard
so choicely. I would think no evil of them for cutting down the woods, did
they but replant again some part of them; but they care nought for the time
to come, neither reck they of the great damage they do to their children
which shall come after them."—Oeuvres Completes de Bernard Pallisy,
1844, p. 88.] The total area of France in Mirabeau's time, excluding Savoy,
but including Alsace and Lorraine, was about one hundred and thirty-one
millions of acres. The extent of forest supposed by Mirabeau would be
about thirty-two per cent. of the whole territory. In a country and a climate
where the conservative influences of the forest are so necessary as in
France, trees must cover a large surface and be grouped in large masses, in
order to discharge to the best advantage the various functions assigned to
them by nature. The consumption of wood is rapidly increasing in that
empire, and a large part of its territory is mountainous, sterile, and
otherwise such in character or situation that it can be more profitably
devoted to the growth of wood than to any agricultural use. Hence it is
Page 398
evident that the proportion of forest in 1750, taking even Mirabeau's large
estimate, was not very much too great for permanent maintenance, though
doubtless the distribution was so unequal that it would have been sound
policy to fell the woods and clear land in some provinces, while large
forests should have been planted in others. [Footnote: The view I have
taken of this point is confirmed by the careful investigation of Rentzsch,
who estimates the proper proportion of woodland to entire surface at
twenty-three per cent. for the interior of Germany, and supposes that near
the coast, where the air is supplied with humidity by evaporation from the
sea, it might safely be reduced to twenty per cent. See Rentzsch's very
valuable prize essay, Der Wald im Haushalt der Natur und der
Volkswirthschaft. cap. viii.
The due proportion in France would considerably exceed that for the
German States, because France has relatively more surface unfit for any
growth but that of wood, because the form and geological character of her
mountains expose her territory to much greater injury from torrents, and
beause at least her southern provinces are more frequently visited both by
extreme droughts and by deluging rains.] During the period in question
France neither exported manufactured wood or rough timber, nor derived
important collateral advantages of any sort from the destruction of her
forests. She is consequently impoverished and crippled to the extent of the
difference between what she actually possesses of wooded surface and what
she ought to have retained. [Footnote: In 1863, France imported lumber to
the value of twenty-five and a half millions of dollars, and exported to the
amount of six and a half millions of dollars. The annual consumption of
France was estimated in 1866 at 212,000,000 cubic feet for building and
manufacturing, and 1,588,300,000 for firewood and charcoal. The annual
product of the forest-soil of France does not exceed 70,000,000 cubic feet
of wood fit for industrial use, and 1,300,000,000 cubic feet consumed as
fuel. This estimate does not include the product of scattered trees on private
estimate, was not very much too great for permanent maintenance, though
doubtless the distribution was so unequal that it would have been sound
policy to fell the woods and clear land in some provinces, while large
forests should have been planted in others. [Footnote: The view I have
taken of this point is confirmed by the careful investigation of Rentzsch,
who estimates the proper proportion of woodland to entire surface at
twenty-three per cent. for the interior of Germany, and supposes that near
the coast, where the air is supplied with humidity by evaporation from the
sea, it might safely be reduced to twenty per cent. See Rentzsch's very
valuable prize essay, Der Wald im Haushalt der Natur und der
Volkswirthschaft. cap. viii.
The due proportion in France would considerably exceed that for the
German States, because France has relatively more surface unfit for any
growth but that of wood, because the form and geological character of her
mountains expose her territory to much greater injury from torrents, and
beause at least her southern provinces are more frequently visited both by
extreme droughts and by deluging rains.] During the period in question
France neither exported manufactured wood or rough timber, nor derived
important collateral advantages of any sort from the destruction of her
forests. She is consequently impoverished and crippled to the extent of the
difference between what she actually possesses of wooded surface and what
she ought to have retained. [Footnote: In 1863, France imported lumber to
the value of twenty-five and a half millions of dollars, and exported to the
amount of six and a half millions of dollars. The annual consumption of
France was estimated in 1866 at 212,000,000 cubic feet for building and
manufacturing, and 1,588,300,000 for firewood and charcoal. The annual
product of the forest-soil of France does not exceed 70,000,000 cubic feet
of wood fit for industrial use, and 1,300,000,000 cubic feet consumed as
fuel. This estimate does not include the product of scattered trees on private
Page 399
grounds, but the consumption is estimated to exceed the production of the
forests by the amount of about twenty millions of dollars. It is worth
noticing that the timber for building and manufacturing produced in France
comes almost wholly from the forests of the state or of the communes.—
Jules Clave, in Revue des Deux Mondes for March 1, 1866, p. 207.]
The force of the various considerations which have been suggested in
regard to the importance of the forest has been generally felt in France, and
the subject has been amply debated special treatises, in scientific journals,
and by the public press, as well as in the legislative body of that country.
Perhaps no one point has been more prominent in the discussions than the
influence of the forest in equalizing and regulating the flow of the water of
precipitation. Opinion is still somewhat divided on this subject, but the
value of the woods as a safeguard against the ravages of torrents is
universally acknowledged, and it is hardly disputed that the rise of river-
floods is, even if as great, at least less sudden in streams having their
sources in well-wooded territory.
Upon the whole, the conservative action of the woods in regard to
torrents and to inundations has ben generally recognized by the public of
France as a matter of prime importance, and the Government of the empire
has made this principle the basis of a special system of legislation for the
protection of existing forests, and for the formation of new. The clearing of
woodland, and the organization and functions of a police for its protection,
are regulated by a law bearing date June 18th, 1859, and provision was
made for promoting the restoration of private woods by a statute adopted on
the 28th of July, 1860. The former of these laws passed the legislative body
by a vote of 246 against 4, the latter with but a single negative voice. The
influence of the Government, in a country where the throne is as potent as
in France, would account for a large majority, but when it is considered that
both laws, the former especially, interfere very materially with the rights of
forests by the amount of about twenty millions of dollars. It is worth
noticing that the timber for building and manufacturing produced in France
comes almost wholly from the forests of the state or of the communes.—
Jules Clave, in Revue des Deux Mondes for March 1, 1866, p. 207.]
The force of the various considerations which have been suggested in
regard to the importance of the forest has been generally felt in France, and
the subject has been amply debated special treatises, in scientific journals,
and by the public press, as well as in the legislative body of that country.
Perhaps no one point has been more prominent in the discussions than the
influence of the forest in equalizing and regulating the flow of the water of
precipitation. Opinion is still somewhat divided on this subject, but the
value of the woods as a safeguard against the ravages of torrents is
universally acknowledged, and it is hardly disputed that the rise of river-
floods is, even if as great, at least less sudden in streams having their
sources in well-wooded territory.
Upon the whole, the conservative action of the woods in regard to
torrents and to inundations has ben generally recognized by the public of
France as a matter of prime importance, and the Government of the empire
has made this principle the basis of a special system of legislation for the
protection of existing forests, and for the formation of new. The clearing of
woodland, and the organization and functions of a police for its protection,
are regulated by a law bearing date June 18th, 1859, and provision was
made for promoting the restoration of private woods by a statute adopted on
the 28th of July, 1860. The former of these laws passed the legislative body
by a vote of 246 against 4, the latter with but a single negative voice. The
influence of the Government, in a country where the throne is as potent as
in France, would account for a large majority, but when it is considered that
both laws, the former especially, interfere very materially with the rights of
Page 400
private domain, the almost entire unanimity with which they were adopted
is proof of a very general popular conviction, that the protection and
extension of the forests is a measure more likely than any other to arrest the
devastations of the torrents and check the violence, if not to prevent the
recurrence, of destructive river inundations. The law of July 28th, 1860,
appropriated 10,000,000 francs, to be expended, at the rate of 1,000,000
francs per year, in executing or aiding the replanting of woods. It is
computed that this appropriation—which, considering the vast importance
of the subject, does not seem extravagant for a nation rich enough to be able
to expend annually six hundred times that sum in the maintenance of its
military establishments in times of peace—will secure the creation of new
forest to the extent of about 200,000 acres, or one fourteenth part of the soil,
where the restoration of the woods is thought feasible, and, at the same
time, specially important as a security against the evils ascribed, in a great
measure, to its destruction. [Footnote: In 1848 the Government of the so-
called French Republic sold to the Bank of France 187,000 acres of public
forests, and notwithstanding the zeal with which the Imperial Government
had pressed the protective Iegislation of 1860, it introduced, into the
Legislative Assembly in 1865 a bill for the sale, and consequently
destruction, of the forests of the state to the amount of one hundred million
francs. The question was much debated in the Assembly, and public opinion
manifested itself so energetically against the measure that the ministry felt
itself compelled to withdraw it. See the discussions in D'Alienation des
Forets de l'Etat. Paris, 1865. The late Imperial Government sold about
170,000 acres of woodland between 1852 and 1866, both inclusive. The
other Governments, since the restoration of the Bourbons in 1814, alienated
more than 700,000 acres of the public forests, exclusive of sales between
1836 and 1857, which are not reported.—Annuaire des Eaux et Forets,
1872, p. 9.]
is proof of a very general popular conviction, that the protection and
extension of the forests is a measure more likely than any other to arrest the
devastations of the torrents and check the violence, if not to prevent the
recurrence, of destructive river inundations. The law of July 28th, 1860,
appropriated 10,000,000 francs, to be expended, at the rate of 1,000,000
francs per year, in executing or aiding the replanting of woods. It is
computed that this appropriation—which, considering the vast importance
of the subject, does not seem extravagant for a nation rich enough to be able
to expend annually six hundred times that sum in the maintenance of its
military establishments in times of peace—will secure the creation of new
forest to the extent of about 200,000 acres, or one fourteenth part of the soil,
where the restoration of the woods is thought feasible, and, at the same
time, specially important as a security against the evils ascribed, in a great
measure, to its destruction. [Footnote: In 1848 the Government of the so-
called French Republic sold to the Bank of France 187,000 acres of public
forests, and notwithstanding the zeal with which the Imperial Government
had pressed the protective Iegislation of 1860, it introduced, into the
Legislative Assembly in 1865 a bill for the sale, and consequently
destruction, of the forests of the state to the amount of one hundred million
francs. The question was much debated in the Assembly, and public opinion
manifested itself so energetically against the measure that the ministry felt
itself compelled to withdraw it. See the discussions in D'Alienation des
Forets de l'Etat. Paris, 1865. The late Imperial Government sold about
170,000 acres of woodland between 1852 and 1866, both inclusive. The
other Governments, since the restoration of the Bourbons in 1814, alienated
more than 700,000 acres of the public forests, exclusive of sales between
1836 and 1857, which are not reported.—Annuaire des Eaux et Forets,
1872, p. 9.]
Page 401
In 1865 the Legislative Assembly passed a bill amendatory of the law of
1860, providing, among other things, for securing the soil in exposed
localities by grading, and by promoting the growth of grass and the
formation of greensward over the surface. This has proved a most beneficial
measure, and its adoption under corresponding conditions in the United
States is most highly to be recommended. The leading features of the
system are:
1. Marking out and securing from pasturage and all other encroachments
a zone along the banks and around the head of ravines.
2. Turfing this zone, which in France accomplishes itself, if not
spontaneously, at least with little aid from art.
3. Consolidation of the scarps of the ravines by grading and wattling and
establishing barriers, sometimes of solid masonry, but generally of fascines
or any other simple materials at hand, across the bed of the stream.
4. Cutting banquettes or narrow terraces along the scarps, and planting
rows of small deciduous trees and arborescent shrubs upon them,
alternating with belts of grass obtained by turfing with sods or sowing
grass-seeds. Planting the banquettes and slopes with bushes, and sowing
any other vegetables with tenacious roots, is also earnestly recommended.
[Footnote: See a description of similar processes recommended and adopted
by Mengotti, in his Idraulica, vol. ii., chap. xvii.]
Remedies against Torrents.
The rural population, which in France is generally hostile to all forest
laws, soon acquiesced in the adoption of this system, and its success has far
surpassed all expectation. At the end of the year 1868 about 190,000 acres
1860, providing, among other things, for securing the soil in exposed
localities by grading, and by promoting the growth of grass and the
formation of greensward over the surface. This has proved a most beneficial
measure, and its adoption under corresponding conditions in the United
States is most highly to be recommended. The leading features of the
system are:
1. Marking out and securing from pasturage and all other encroachments
a zone along the banks and around the head of ravines.
2. Turfing this zone, which in France accomplishes itself, if not
spontaneously, at least with little aid from art.
3. Consolidation of the scarps of the ravines by grading and wattling and
establishing barriers, sometimes of solid masonry, but generally of fascines
or any other simple materials at hand, across the bed of the stream.
4. Cutting banquettes or narrow terraces along the scarps, and planting
rows of small deciduous trees and arborescent shrubs upon them,
alternating with belts of grass obtained by turfing with sods or sowing
grass-seeds. Planting the banquettes and slopes with bushes, and sowing
any other vegetables with tenacious roots, is also earnestly recommended.
[Footnote: See a description of similar processes recommended and adopted
by Mengotti, in his Idraulica, vol. ii., chap. xvii.]
Remedies against Torrents.
The rural population, which in France is generally hostile to all forest
laws, soon acquiesced in the adoption of this system, and its success has far
surpassed all expectation. At the end of the year 1868 about 190,000 acres
Page 402
had been planted with trees, [Footnote: Travellers spending the winter at
Nice may have a good opportunity of studying the methods of forming and
conducting the rewooding of mountain slopes, under the most unfavorable
conditions, by visiting Mont Boron, in the immediate vicinity of that city,
and other coast plantations in that province, where great difficulties have
been completely overcome by the skill and perseverance of French
foresters. See Les Forets des Maures, Revue des Eaux et Forets, January,
1869.] and nearly 7,000 acres well turfed over in the Department of the
Hautes Alpes. Many hundred ravines, several of which had been the
channels of formidable torrents, had been secured by barriers, grading and
planting, and according to official reports the aspect of the mountains in the
Department, wherever these methods were employed, had rapidly changed.
The soil had acquired such stability that the violent rains of 1868, so
destructive elsewhere, produced no damage in the districts which had been
subjected to these operations, and numerous growing torrents which
threatened irreparable mischief had been completely extinguished, or at
least rendered altogether harmless. [Footnote: For ample details of
processes and results, see the second volume of Surrell, Etudes sur les
Torrents, Paris, 1872, and a Report by De La Grye, in the Revue des Eaux
et Forets for January, 1869.]
Besides the processes directed by the Government of France, various
subsidiary measures of an easily and economically practicable character
have been suggested. Among them is one which has long been favorably
known in our Southern States under the name of circling, and the adoption
of which in hilly regions in other States is to be strongly recommended.
It is simply a method of preventing the wash of surface by rains, and at
the same time of providing a substitute for irrigation of steep pasture-
grounds, consisting in little more than in running horizontal furrows along
the hillsides, thus converting the scarp of the hills into a succession of small
Nice may have a good opportunity of studying the methods of forming and
conducting the rewooding of mountain slopes, under the most unfavorable
conditions, by visiting Mont Boron, in the immediate vicinity of that city,
and other coast plantations in that province, where great difficulties have
been completely overcome by the skill and perseverance of French
foresters. See Les Forets des Maures, Revue des Eaux et Forets, January,
1869.] and nearly 7,000 acres well turfed over in the Department of the
Hautes Alpes. Many hundred ravines, several of which had been the
channels of formidable torrents, had been secured by barriers, grading and
planting, and according to official reports the aspect of the mountains in the
Department, wherever these methods were employed, had rapidly changed.
The soil had acquired such stability that the violent rains of 1868, so
destructive elsewhere, produced no damage in the districts which had been
subjected to these operations, and numerous growing torrents which
threatened irreparable mischief had been completely extinguished, or at
least rendered altogether harmless. [Footnote: For ample details of
processes and results, see the second volume of Surrell, Etudes sur les
Torrents, Paris, 1872, and a Report by De La Grye, in the Revue des Eaux
et Forets for January, 1869.]
Besides the processes directed by the Government of France, various
subsidiary measures of an easily and economically practicable character
have been suggested. Among them is one which has long been favorably
known in our Southern States under the name of circling, and the adoption
of which in hilly regions in other States is to be strongly recommended.
It is simply a method of preventing the wash of surface by rains, and at
the same time of providing a substitute for irrigation of steep pasture-
grounds, consisting in little more than in running horizontal furrows along
the hillsides, thus converting the scarp of the hills into a succession of small
Page 403
terraces which, when once turfed over, are very permanent. Experience is
said to have demonstrated that this simple process at least partially checks
the too rapid flow of surface-water into the valleys, and, consequently, in a
great measure obviates one of the most prominent causes of inundations,
and that it suffices to retain the water of rains, of snows, and of small
springs, long enough for the irrigation of the soil, thus increasing its product
of herbage in a fivefold proportion. [Footnote: Troy, Etude sur le
Reboisement des Montagnes, sections 6, 7, 21.]
As a further recommendation, it may be observed that this process is an
admirable preparation of the ground for forest plantations, as young trees
planted on the terraces would derive a useful protection from the form of
the surface and the coating of turf, and would also find a soil moist enough
to secure their growth.
Forests of Italy.
According to the most recent statistics, Italy has 17.64 per cent. of
woodland, [Footnote: Siemoni, Manuale d'Arte Forestale, 2 ediz., Firenze,
1872, p. 542.] a proportion which, considering the character of climate and
surface, the great amount of soil which is fit for no other purpose than the
growth of trees, and the fact that much of the land classed as forest is either
very imperfectly wooded, or covered with groves badly administered, and
not in a state of progressive improvement, might advantageously be
doubled. Taking Italy as a whole, we may say that she is eminently fitted by
climate, soil, and superficial formation, to the growth of a varied and
luxuriant arboreal vegetation, and that in the interests of self-protection, the
promotion of forestal industry is among the first duties of her people. There
are in Western Piedmont valleys where the felling of the woods has
produced consequences geographically and economically as disastrous as in
South-eastern France, and there are many other districts in the Alps and the
said to have demonstrated that this simple process at least partially checks
the too rapid flow of surface-water into the valleys, and, consequently, in a
great measure obviates one of the most prominent causes of inundations,
and that it suffices to retain the water of rains, of snows, and of small
springs, long enough for the irrigation of the soil, thus increasing its product
of herbage in a fivefold proportion. [Footnote: Troy, Etude sur le
Reboisement des Montagnes, sections 6, 7, 21.]
As a further recommendation, it may be observed that this process is an
admirable preparation of the ground for forest plantations, as young trees
planted on the terraces would derive a useful protection from the form of
the surface and the coating of turf, and would also find a soil moist enough
to secure their growth.
Forests of Italy.
According to the most recent statistics, Italy has 17.64 per cent. of
woodland, [Footnote: Siemoni, Manuale d'Arte Forestale, 2 ediz., Firenze,
1872, p. 542.] a proportion which, considering the character of climate and
surface, the great amount of soil which is fit for no other purpose than the
growth of trees, and the fact that much of the land classed as forest is either
very imperfectly wooded, or covered with groves badly administered, and
not in a state of progressive improvement, might advantageously be
doubled. Taking Italy as a whole, we may say that she is eminently fitted by
climate, soil, and superficial formation, to the growth of a varied and
luxuriant arboreal vegetation, and that in the interests of self-protection, the
promotion of forestal industry is among the first duties of her people. There
are in Western Piedmont valleys where the felling of the woods has
produced consequences geographically and economically as disastrous as in
South-eastern France, and there are many other districts in the Alps and the
Page 404
Apennines where human improvidence has been almost equally destructive.
Some of these regions must be abandoned to absolute desolation, and for
others the opportunity of physical restoration is rapidly passing away. But
there are still millions of square miles which might profitably be planted
with forest-trees, and thousands of acres of parched and barren hillside,
within sight of almost every Italian provincial capital, which might easily
and shortly be reclothed with verdant woods. [Footnote: To one accustomed
to the slow vegetation of less favored climes, the rapidity of growth in
young plantations in Italy seems almost magical. The trees planted along
the new drives and avenues in Florence have attained in three or four years
a development which would require at least ten in our Northern States. This,
it is true, is a special case, for the trees have been planted and tended with a
skill and care which cannot be bestowed upon a forest; but the growth of
trees little cared for is still very rapid in Italy. According to Toscanelli,
Economia rurale nella Provincia di Pisa, p. 8, note—one of the most
complete, curious, and instructive pictures of rural life which exists in any
literature—the white poplar, Populus alba, attains in the valley of the
Serchio a great height, with a mean diameter of two feet, in twenty years.
Solmi states in his Miasma Palustre, p. 115, that the linden reaches a
diameter of sixteen inches in the same period. The growth of foreign trees is
sometimes extremely luxuriant in Italy. Two Atlas cedars, at the well-known
villa of Careggi, near Florence, grown from seed sown in 1850, measure
twenty inches in diameter, above the swell of the roots, with an estimated
height of sixty feet.]
The denudation of the Central and Southern Apennines and of the Italian
declivity of the Western Alps began at a period of unknown antiquity, but it
does not seem to have been carried to a very dangerous length until the
foreign conquests and extended commerce of Rome created a greatly
increased demand for wood for the construction of ships and for military
material. [Footnote: An interesting example of the collateral effects of the
Some of these regions must be abandoned to absolute desolation, and for
others the opportunity of physical restoration is rapidly passing away. But
there are still millions of square miles which might profitably be planted
with forest-trees, and thousands of acres of parched and barren hillside,
within sight of almost every Italian provincial capital, which might easily
and shortly be reclothed with verdant woods. [Footnote: To one accustomed
to the slow vegetation of less favored climes, the rapidity of growth in
young plantations in Italy seems almost magical. The trees planted along
the new drives and avenues in Florence have attained in three or four years
a development which would require at least ten in our Northern States. This,
it is true, is a special case, for the trees have been planted and tended with a
skill and care which cannot be bestowed upon a forest; but the growth of
trees little cared for is still very rapid in Italy. According to Toscanelli,
Economia rurale nella Provincia di Pisa, p. 8, note—one of the most
complete, curious, and instructive pictures of rural life which exists in any
literature—the white poplar, Populus alba, attains in the valley of the
Serchio a great height, with a mean diameter of two feet, in twenty years.
Solmi states in his Miasma Palustre, p. 115, that the linden reaches a
diameter of sixteen inches in the same period. The growth of foreign trees is
sometimes extremely luxuriant in Italy. Two Atlas cedars, at the well-known
villa of Careggi, near Florence, grown from seed sown in 1850, measure
twenty inches in diameter, above the swell of the roots, with an estimated
height of sixty feet.]
The denudation of the Central and Southern Apennines and of the Italian
declivity of the Western Alps began at a period of unknown antiquity, but it
does not seem to have been carried to a very dangerous length until the
foreign conquests and extended commerce of Rome created a greatly
increased demand for wood for the construction of ships and for military
material. [Footnote: An interesting example of the collateral effects of the
Page 405
destruction of the forests in ancient Italy may be found in old Roman
architecture. In the oldest brick constructions of Rome the bricks are very
thin, very thoroughly burnt, and laid with a thick stratum of mortar between
the courses. A few centuries later the bricks were thicker and less well
burnt, and the layers of mortar were thinner. In the Imperial period the
bricks were still thicker, generally soft-burnt, and with little mortar between
the courses. This fact, I think, is due to the abundance and cheapness of fuel
in earlier, and its growing scarceness and dearness in later, ages. When
wood cost little, constructors could afford to burn their brick thoroughly,
and to burn and use a great quantity of lime. As the price of fire-wood
advanced, they were able to consume less fuel in brick- and lime-kilns, and
the quality and quantity of brick and lime used in building were gradually
reversed in proportion.
The multitude of geographical designations in Italy which indicate the
former existence of forests show that even in the Middle Ages there were
woods where no forest-trees are now to be found. There are hundreds of
names of mediaeval towns derived from abete, acero, carpino, castagno,
faggio, frassino, pino, quercia, and other names of trees.] The Eastern Alps,
the Western Apennines, and the Maritime Alps retained their forests much
later; but even here the want of wood, and the injury to the plains and the
nagivation of the rivers by sediment brought down by the torrents, led to
legislation for the protection of the forests, by the Republic of Venice, at
various periods between the fifteenth and the nineteenth centuries,
[Footnote: See A. de Bereuger's valuable Saggio Storico della Legislazione
Veneta Forestale. Venezia, 1863.
We do not find in the Venetian forestal legislation much evidence that
geographical arguments were taken into account by the lawgivers, who
seem to have had an eye only to economical considerations.
architecture. In the oldest brick constructions of Rome the bricks are very
thin, very thoroughly burnt, and laid with a thick stratum of mortar between
the courses. A few centuries later the bricks were thicker and less well
burnt, and the layers of mortar were thinner. In the Imperial period the
bricks were still thicker, generally soft-burnt, and with little mortar between
the courses. This fact, I think, is due to the abundance and cheapness of fuel
in earlier, and its growing scarceness and dearness in later, ages. When
wood cost little, constructors could afford to burn their brick thoroughly,
and to burn and use a great quantity of lime. As the price of fire-wood
advanced, they were able to consume less fuel in brick- and lime-kilns, and
the quality and quantity of brick and lime used in building were gradually
reversed in proportion.
The multitude of geographical designations in Italy which indicate the
former existence of forests show that even in the Middle Ages there were
woods where no forest-trees are now to be found. There are hundreds of
names of mediaeval towns derived from abete, acero, carpino, castagno,
faggio, frassino, pino, quercia, and other names of trees.] The Eastern Alps,
the Western Apennines, and the Maritime Alps retained their forests much
later; but even here the want of wood, and the injury to the plains and the
nagivation of the rivers by sediment brought down by the torrents, led to
legislation for the protection of the forests, by the Republic of Venice, at
various periods between the fifteenth and the nineteenth centuries,
[Footnote: See A. de Bereuger's valuable Saggio Storico della Legislazione
Veneta Forestale. Venezia, 1863.
We do not find in the Venetian forestal legislation much evidence that
geographical arguments were taken into account by the lawgivers, who
seem to have had an eye only to economical considerations.
Page 406
According to Hummel, the desolation of the Karst, the high plateau lying
north of Trieste, now one of the most parched and barren districts in
Europe, is owing to the felling of the woods, centuries ago, to build the
navies of Venice. "Where the miserable peasant of the Karst now sees
nothing but bare rock swept and scoured by the raging Bora, the fury of this
wind was once subdued by mighty firs, which Venice recklessly cut down
to build her fleets."—Physische Geographie, p. 32.] by that of Genoa as
early at least as the seventeenth; and both these Governments, as well as
several others, passed laws requiring the proprietors of mountain-lands to
replant the woods. These, however, seem to have been little observed, and it
is generally true that the present condition of the forest in Italy is much less
due to the want of wise legislation for its protection than to the laxity of the
Governments in enforcing their laws.
It is very common in Italy to ascribe to the French occupation under the
first Empire all the improvements and all the abuses of recent times,
according to the political sympathies of the individual; and the French are
often said to have prostrated every forest which has disappeared within this
century. But, however this may be, no energetic system of repression or
restoration was adopted by any of the Italian States after the downfall of the
Empire, and the taxes on forest property in some of them were so
burdensome that rural municipalities sometimes proposed to cede their
common woods to the Government, without any other compensation than
the remission of the taxes imposed on forest-lands. [Footnote: See the
Politecnico for the month of May, 1862, p. 234.] Under such circumstances,
woodlands would soon become disafforested, and where facilities of
transportation and a good demand for timber have increased the
inducements to fell it, as upon the borders of the Mediterranean, the
destruction of the forest and all the evils which attend it have gone on at a
seriously alarming rate.
north of Trieste, now one of the most parched and barren districts in
Europe, is owing to the felling of the woods, centuries ago, to build the
navies of Venice. "Where the miserable peasant of the Karst now sees
nothing but bare rock swept and scoured by the raging Bora, the fury of this
wind was once subdued by mighty firs, which Venice recklessly cut down
to build her fleets."—Physische Geographie, p. 32.] by that of Genoa as
early at least as the seventeenth; and both these Governments, as well as
several others, passed laws requiring the proprietors of mountain-lands to
replant the woods. These, however, seem to have been little observed, and it
is generally true that the present condition of the forest in Italy is much less
due to the want of wise legislation for its protection than to the laxity of the
Governments in enforcing their laws.
It is very common in Italy to ascribe to the French occupation under the
first Empire all the improvements and all the abuses of recent times,
according to the political sympathies of the individual; and the French are
often said to have prostrated every forest which has disappeared within this
century. But, however this may be, no energetic system of repression or
restoration was adopted by any of the Italian States after the downfall of the
Empire, and the taxes on forest property in some of them were so
burdensome that rural municipalities sometimes proposed to cede their
common woods to the Government, without any other compensation than
the remission of the taxes imposed on forest-lands. [Footnote: See the
Politecnico for the month of May, 1862, p. 234.] Under such circumstances,
woodlands would soon become disafforested, and where facilities of
transportation and a good demand for timber have increased the
inducements to fell it, as upon the borders of the Mediterranean, the
destruction of the forest and all the evils which attend it have gone on at a
seriously alarming rate.
Page 407
Gallenga gives a striking account of the wanton destruction of the forests
in Northern Italy within his personal recollection, [Footnote: "Far away in
the darkest recesses of the mountains a kind of universal conspiracy seems
to have been got up among these Alpine people,—a destructive mania to
hew and sweep down everything that stands on roots."—Country Life in
Piedmont, p. 134.
"There are huge pyramids of mountains now bare and bleak from base to
summit, which men still living and still young remember seeing richly
mantled with all but primeval forests."—Ibid., p. 135.] and there are few
Italians past middle life whose own memory will not supply similar
reminiscences. The clearing of the mountain valleys of the provinces of
Bergamo and of Bescia is recent, and Lombardini informs us the felling of
the woods in the Valtelline commenced little more than forty years ago.
Although no country has produced more able writers on the value of the
forest and the general consequences of its destruction than Italy, yet the
specific geographical importance of the woods, except as a protection
against inundations, has not been so clearly recognized in that country as in
the States bordering it on the north and west. It is true that the face of nature
has been as completely revolutionized by man, and that the action of
torrents has created almost as wide and as hopeless devastation in Italy as in
France; but in the French Empire the recent desolation produced by clearing
the forests is more extensive, has been more suddenly effected, has
occurred in less remote and obscure localities, and therefore, excites a
livelier and more general interest than in Italy, where public opinion does
not so readily connect the effect with its true cause. Italy, too, from ancient
habit, employs little wood in architectural construction; for generations she
has maintained no military or commercial marine large enough to require
exhaustive quantities of timber, [Footnote: The great naval and commercial
marines of Venice and of Genoa must have occasioned an immense
in Northern Italy within his personal recollection, [Footnote: "Far away in
the darkest recesses of the mountains a kind of universal conspiracy seems
to have been got up among these Alpine people,—a destructive mania to
hew and sweep down everything that stands on roots."—Country Life in
Piedmont, p. 134.
"There are huge pyramids of mountains now bare and bleak from base to
summit, which men still living and still young remember seeing richly
mantled with all but primeval forests."—Ibid., p. 135.] and there are few
Italians past middle life whose own memory will not supply similar
reminiscences. The clearing of the mountain valleys of the provinces of
Bergamo and of Bescia is recent, and Lombardini informs us the felling of
the woods in the Valtelline commenced little more than forty years ago.
Although no country has produced more able writers on the value of the
forest and the general consequences of its destruction than Italy, yet the
specific geographical importance of the woods, except as a protection
against inundations, has not been so clearly recognized in that country as in
the States bordering it on the north and west. It is true that the face of nature
has been as completely revolutionized by man, and that the action of
torrents has created almost as wide and as hopeless devastation in Italy as in
France; but in the French Empire the recent desolation produced by clearing
the forests is more extensive, has been more suddenly effected, has
occurred in less remote and obscure localities, and therefore, excites a
livelier and more general interest than in Italy, where public opinion does
not so readily connect the effect with its true cause. Italy, too, from ancient
habit, employs little wood in architectural construction; for generations she
has maintained no military or commercial marine large enough to require
exhaustive quantities of timber, [Footnote: The great naval and commercial
marines of Venice and of Genoa must have occasioned an immense
Page 408
consumption of lumber in the Middle Ages, and the centuries immediately
succeeding those commonly embraced in that designation. The marine
construction of that period employed larger timbers than the modern naval
architecture of most commercial countries, but apparently without a
proportional increase of strength. The old modes of ship-building have
been, to a considerable extent, handed down to very recent times in the
Mediterranean, and though better models and modes of construction are
now employed in Italian shipyards, an American or an Englishman looks
with astonishment at the huge beams and thick planks so often employed in
the construction of very small vessels navigating that sea, and not yet old
enough to be broken up as unseaworthy.] and the mildness of her climate
makes small demands on the woods for fuel. Besides these circumstances, it
must be remembered that the sciences of observation did not become
knowledges of practical application till after the mischief was already
mainly done and even forgotten in Alpine Italy, while its evils were just
beginning to be sensibly felt in France when the claims of natural
philosophy as a liberal study were first acknowledged in modern Europe.
The former political condition of the Italian Peninsula would have
effectually prevented the adoption of a general system of forest economy,
however clearly the importance of a wise administration of this great public
interest might have been understood. The woods which controlled and
regulated the flow of the river-sources were very often in one jurisdiction,
the plains to be irrigated, or to be inundated by floods and desolated by
torrents, in another. Concert of action, on such a subject, between a
multitude of jealous petty sovereignties, was obviously impossible, and
nothing but the permanent union of all the Italian States under a single
government can render practicable the establishment of such arrangements
for the conservation and restoration of the forests, and the regulation of the
flow of the waters, as are necessary for the full development of the yet
succeeding those commonly embraced in that designation. The marine
construction of that period employed larger timbers than the modern naval
architecture of most commercial countries, but apparently without a
proportional increase of strength. The old modes of ship-building have
been, to a considerable extent, handed down to very recent times in the
Mediterranean, and though better models and modes of construction are
now employed in Italian shipyards, an American or an Englishman looks
with astonishment at the huge beams and thick planks so often employed in
the construction of very small vessels navigating that sea, and not yet old
enough to be broken up as unseaworthy.] and the mildness of her climate
makes small demands on the woods for fuel. Besides these circumstances, it
must be remembered that the sciences of observation did not become
knowledges of practical application till after the mischief was already
mainly done and even forgotten in Alpine Italy, while its evils were just
beginning to be sensibly felt in France when the claims of natural
philosophy as a liberal study were first acknowledged in modern Europe.
The former political condition of the Italian Peninsula would have
effectually prevented the adoption of a general system of forest economy,
however clearly the importance of a wise administration of this great public
interest might have been understood. The woods which controlled and
regulated the flow of the river-sources were very often in one jurisdiction,
the plains to be irrigated, or to be inundated by floods and desolated by
torrents, in another. Concert of action, on such a subject, between a
multitude of jealous petty sovereignties, was obviously impossible, and
nothing but the permanent union of all the Italian States under a single
government can render practicable the establishment of such arrangements
for the conservation and restoration of the forests, and the regulation of the
flow of the waters, as are necessary for the full development of the yet
Page 409
unexhausted resources of that fairest of lands, and even for the maintenance
of the present condition of its physical geography.
The Forests of Germany.
Germany, including a considerable part of the Austrian Empire, from
character of surface and climate, and from the attention which has long
been paid in all the German States to sylviculture, is in a far better condition
in this respect than its more southern neighbors; and though in the Alpine
provinces of Bavaria and Austria the corresponding districts of Switzerland,
Italy, and France, has produced effects hardly less disastrous, [Footnote: As
an instance of the scarcity of fuel in some parts of the territory of Bavaria,
where, not long since, wood abounded, I may mention the fact that the
water of salt-springs is, in some instances, conveyed to the distance of sixty
miles, in iron pipes, to reach a supply of fuel for boiling it down.
In France, the juice of the sugar-beet is sometimes carried three or four
miles in pipes for the same reason.
Many of my readers may remember that it was not long ago proposed to
manufacture the gas for the supply of London at the mouths of the coal-
mines, and convey it to the city in pipes, thus saving the transportation of
the coal; but as the coke and mineral tar would still have remained to be
disposed of, the operation would probably not have proved advantageous.
Great economy in the production of petroleum has resulted from the
application of cast-iron tubes to the wells instead of barrels; the oil is thus
carried over the various inequalities of surface for three or four miles to the
tanks on the railroads, and forced into them by steam-engines. The price of
transport is thus reduced one-fifth.] yet, as a whole, the German States, as
Siemoni well observes, must be considered as in this respect the model
of the present condition of its physical geography.
The Forests of Germany.
Germany, including a considerable part of the Austrian Empire, from
character of surface and climate, and from the attention which has long
been paid in all the German States to sylviculture, is in a far better condition
in this respect than its more southern neighbors; and though in the Alpine
provinces of Bavaria and Austria the corresponding districts of Switzerland,
Italy, and France, has produced effects hardly less disastrous, [Footnote: As
an instance of the scarcity of fuel in some parts of the territory of Bavaria,
where, not long since, wood abounded, I may mention the fact that the
water of salt-springs is, in some instances, conveyed to the distance of sixty
miles, in iron pipes, to reach a supply of fuel for boiling it down.
In France, the juice of the sugar-beet is sometimes carried three or four
miles in pipes for the same reason.
Many of my readers may remember that it was not long ago proposed to
manufacture the gas for the supply of London at the mouths of the coal-
mines, and convey it to the city in pipes, thus saving the transportation of
the coal; but as the coke and mineral tar would still have remained to be
disposed of, the operation would probably not have proved advantageous.
Great economy in the production of petroleum has resulted from the
application of cast-iron tubes to the wells instead of barrels; the oil is thus
carried over the various inequalities of surface for three or four miles to the
tanks on the railroads, and forced into them by steam-engines. The price of
transport is thus reduced one-fifth.] yet, as a whole, the German States, as
Siemoni well observes, must be considered as in this respect the model
Page 410
countries of Europe. Not only is the forest area in general maintained
without diminution, but new woods are planted where they are specially
needed, [Footnote: The Austrian Government is making energetic efforts for
the propagation of forests on the desolate waste of the Karst. The
difficulties from drought and from the violence of the winds, which might
prove fatal to young and even to somewhat advanced plantations, are very
serious, but in 1866 upwards of 400,000 trees had been planted and great
quantities of seeds sown. Thus far, the results of this important experiment
are said to be encouraging. See the Chronique Forestiere in the Revue des
Eaux et Forets, Feb. 1870.] and, though the slow growth of forest-trees in
those climates reduces the direct pecuniary returns of woodlands to a
minimum, the governments wisely persevere in encouraging this industry.
The exportation of sawn lumber from Trieste is large, and in fact the
Turkish and Egyptian markets are in great part supplied from this source.
[Footnote: For information respecting the forests of Germany, as well as
other European countries, see, besides the works already cited, the very
valuable Manuale d'Arts Forestale of Siemoni, 2de edizione, Firenze, 1872.]
Forests of Russia.
Russia, which we habitually consider as substantially a forest country—
which has in fact a large proportion of woodland—is beginning to suffer
seriously for want of wood. Jourdier observes: "Instead of a vast territory
with immense forests, which we expect to meet, one sees only scattered
groves thinned by the wind or by the axe of the moujik, grounds cut over
and more or less recently cleared for cultivation. There is probably not a
single district in Russia which has not to deplore the ravages of man or of
fire, those two great enemies of Muscovite sylviculture. This is so true, that
clear-sighted men already foresee a crisis which will become terrible, unless
the discovery of great deposits of some new combustible, as pit-coal or
without diminution, but new woods are planted where they are specially
needed, [Footnote: The Austrian Government is making energetic efforts for
the propagation of forests on the desolate waste of the Karst. The
difficulties from drought and from the violence of the winds, which might
prove fatal to young and even to somewhat advanced plantations, are very
serious, but in 1866 upwards of 400,000 trees had been planted and great
quantities of seeds sown. Thus far, the results of this important experiment
are said to be encouraging. See the Chronique Forestiere in the Revue des
Eaux et Forets, Feb. 1870.] and, though the slow growth of forest-trees in
those climates reduces the direct pecuniary returns of woodlands to a
minimum, the governments wisely persevere in encouraging this industry.
The exportation of sawn lumber from Trieste is large, and in fact the
Turkish and Egyptian markets are in great part supplied from this source.
[Footnote: For information respecting the forests of Germany, as well as
other European countries, see, besides the works already cited, the very
valuable Manuale d'Arts Forestale of Siemoni, 2de edizione, Firenze, 1872.]
Forests of Russia.
Russia, which we habitually consider as substantially a forest country—
which has in fact a large proportion of woodland—is beginning to suffer
seriously for want of wood. Jourdier observes: "Instead of a vast territory
with immense forests, which we expect to meet, one sees only scattered
groves thinned by the wind or by the axe of the moujik, grounds cut over
and more or less recently cleared for cultivation. There is probably not a
single district in Russia which has not to deplore the ravages of man or of
fire, those two great enemies of Muscovite sylviculture. This is so true, that
clear-sighted men already foresee a crisis which will become terrible, unless
the discovery of great deposits of some new combustible, as pit-coal or
Page 411
anthracite, shall diminish its evils." [Footnote: Clave, Etudes sur l'Economie
Forestiere, p. 261. Clave adds (p. 262): "The Russian forests are very
unequally distributed through the territory of this vast empire. In the north
they form immense masses, and cover whole provinces, while in the south
they are so completely wanting that the inhabitants have no other fuel than
straw, dung, rushes, and heath." … "At Moscow, firewood costs thirty per
cent. more than at Paris, while, at the distance of a few leagues, it sells for a
tenth of that price."
This state of things is partly due to the want of facilities of transportation,
and some parts of the United States are in a similar condition. During a
severe winter, ten or twelve years ago, the sudden freezing of the canals and
rivers, before a large American town had received its usual supply of fuel,
occasioned an enormous rise in the price of wood and coal, and the poor
suffered severely for want of it. Within a few hours of the city were large
forests and an abundant stock of firewood felled and prepared for burning.
This might easily have been carried to town by the railroads which
passed through the woods; but the managers of the roads refused to receive
it as freight, because a rival market for wood might raise the price of the
fuel they employed for their locomotives. Truly, our railways "want a
master."
Hohenstein, who was long professionally employed as a forester in
Russia, describes the consequences of the general war upon the woods in
that country as already most disastrous, and as threatening still more
ruinous evils. The river Volga, the life artery of Russian internal commerce,
is drying up from this cause, and the great Muscovite plains are fast
advancing to a desolation like that of Persia.—Der Wald, p. 223.
The level of the Caspian Sea is eighty-three feet lower than that of the
Sea of Azoff, and the surface of Lake Aral is fast sinking. Von Baer
Forestiere, p. 261. Clave adds (p. 262): "The Russian forests are very
unequally distributed through the territory of this vast empire. In the north
they form immense masses, and cover whole provinces, while in the south
they are so completely wanting that the inhabitants have no other fuel than
straw, dung, rushes, and heath." … "At Moscow, firewood costs thirty per
cent. more than at Paris, while, at the distance of a few leagues, it sells for a
tenth of that price."
This state of things is partly due to the want of facilities of transportation,
and some parts of the United States are in a similar condition. During a
severe winter, ten or twelve years ago, the sudden freezing of the canals and
rivers, before a large American town had received its usual supply of fuel,
occasioned an enormous rise in the price of wood and coal, and the poor
suffered severely for want of it. Within a few hours of the city were large
forests and an abundant stock of firewood felled and prepared for burning.
This might easily have been carried to town by the railroads which
passed through the woods; but the managers of the roads refused to receive
it as freight, because a rival market for wood might raise the price of the
fuel they employed for their locomotives. Truly, our railways "want a
master."
Hohenstein, who was long professionally employed as a forester in
Russia, describes the consequences of the general war upon the woods in
that country as already most disastrous, and as threatening still more
ruinous evils. The river Volga, the life artery of Russian internal commerce,
is drying up from this cause, and the great Muscovite plains are fast
advancing to a desolation like that of Persia.—Der Wald, p. 223.
The level of the Caspian Sea is eighty-three feet lower than that of the
Sea of Azoff, and the surface of Lake Aral is fast sinking. Von Baer
Page 412
maintains that the depression of the Caspian was produced by a sudden
subsidence, from ecological causes, and not gradually by excess of
evaporation over supply. See Kaspische Studien, p. 25. But this subsidence
diminished the area and consequently the evaporation of that sea, and the
rivers which once maintained its ancient equilibrium ought to have raised it
to its former level, if their own flow had not been diminished. It is, indeed,
not proved that the laying bare of a wooded country diminishes the total
annual precipitation upon it; but it is certain that the summer delivery of
water from the surface of a champaign region, like that through which the
Volga, its tributaries, and the feeders of Lake Aral, flow, is lessened by the
removal of its woods. Hence, though as much rain may still fall in the
valleys of those rivers as when their whole surface was covered with
forests, more moisture may be carried off by evaporation, and a less
quantity of water be discharged by the rivers since their basins were
cleared, and therefore the present condition of the inland waters in question
may be due to the removal of the forests in their valleys and the adjacent
plains.]
Forests of United States.
I greatly doubt whether any one of the American States, except, perhaps,
Oregon, has, at this moment, more woodland than it ought permanently to
preserve, though, no doubt, a different distribution of the forests in all of
them might be highly advantageous. It is, perhaps, a misfortune to the
American Union that the State Governments have so generally disposed of
their original domain to private citizens. It is true that public property is not
sufficiently respected in the United States; and within the memory of almost
every man of mature age, timber was of so little value in the northernmost
States that the owners of private woodlands submitted, almost without
complaint, to what would be regarded elsewhere as very aggravated
subsidence, from ecological causes, and not gradually by excess of
evaporation over supply. See Kaspische Studien, p. 25. But this subsidence
diminished the area and consequently the evaporation of that sea, and the
rivers which once maintained its ancient equilibrium ought to have raised it
to its former level, if their own flow had not been diminished. It is, indeed,
not proved that the laying bare of a wooded country diminishes the total
annual precipitation upon it; but it is certain that the summer delivery of
water from the surface of a champaign region, like that through which the
Volga, its tributaries, and the feeders of Lake Aral, flow, is lessened by the
removal of its woods. Hence, though as much rain may still fall in the
valleys of those rivers as when their whole surface was covered with
forests, more moisture may be carried off by evaporation, and a less
quantity of water be discharged by the rivers since their basins were
cleared, and therefore the present condition of the inland waters in question
may be due to the removal of the forests in their valleys and the adjacent
plains.]
Forests of United States.
I greatly doubt whether any one of the American States, except, perhaps,
Oregon, has, at this moment, more woodland than it ought permanently to
preserve, though, no doubt, a different distribution of the forests in all of
them might be highly advantageous. It is, perhaps, a misfortune to the
American Union that the State Governments have so generally disposed of
their original domain to private citizens. It is true that public property is not
sufficiently respected in the United States; and within the memory of almost
every man of mature age, timber was of so little value in the northernmost
States that the owners of private woodlands submitted, almost without
complaint, to what would be regarded elsewhere as very aggravated
Page 413
trespasses upon them. [Footnote: According to the maxims of English
jurisprudence, the common law consists of general customs so long
established that "the memory of man runneth not to the contrary." In other
words, long custom makes law. In new countries, the change of
circumstances creates new customs, and, in time, new law, without the aid
of legislation. Had the American colonists observed a more sparing
economy in the treatment of their woods, a new code of customary forest-
law would have sprung up and acquired the force of a statute. Popular habit
was fast elaborating the fundamental principles of such a code, when the
rapid increase in the value of timber, in consequence of the reckless
devastation of the woodlands, made it the interest of the proprietors to
interfere with this incipient system of forest jurisprudence, and appeal to the
rules of English law for the protection of their woods. The courts have
sustained these appeals, and forest property is now legally as inviolable as
any other, though common opinion still combats the course of judicial
decision on such questions.] Persons in want of timber helped themselves to
it wherever they could find it, and a claim for damages, for so insignificant
a wrong as cutting down and carrying off a few pine or oak trees, was
regarded as a mean-spirited act in a proprietor. The habits formed at this
period are not altogether obsolete, and even now the notion of a common
right of property in the woods still lingers, if not as an opinion at least as a
sentiment. Under such circumstances it has been difficult to protect the
forest, whether it belong to the State or to individuals. Property of this kind
is subject to plunder, as well as to frequent damage by fire. The destruction
from these causes would, indeed, considerably lessen, but would by no
means wholly annihilate the climatic and geographical influences of the
forest, or ruinously diminish its value as a regular source of supply of fuel
and timber.
It is evidently a matter of the utmost importance that the public, and
especially land-owners, be roused to a sense of the dangers to which the
jurisprudence, the common law consists of general customs so long
established that "the memory of man runneth not to the contrary." In other
words, long custom makes law. In new countries, the change of
circumstances creates new customs, and, in time, new law, without the aid
of legislation. Had the American colonists observed a more sparing
economy in the treatment of their woods, a new code of customary forest-
law would have sprung up and acquired the force of a statute. Popular habit
was fast elaborating the fundamental principles of such a code, when the
rapid increase in the value of timber, in consequence of the reckless
devastation of the woodlands, made it the interest of the proprietors to
interfere with this incipient system of forest jurisprudence, and appeal to the
rules of English law for the protection of their woods. The courts have
sustained these appeals, and forest property is now legally as inviolable as
any other, though common opinion still combats the course of judicial
decision on such questions.] Persons in want of timber helped themselves to
it wherever they could find it, and a claim for damages, for so insignificant
a wrong as cutting down and carrying off a few pine or oak trees, was
regarded as a mean-spirited act in a proprietor. The habits formed at this
period are not altogether obsolete, and even now the notion of a common
right of property in the woods still lingers, if not as an opinion at least as a
sentiment. Under such circumstances it has been difficult to protect the
forest, whether it belong to the State or to individuals. Property of this kind
is subject to plunder, as well as to frequent damage by fire. The destruction
from these causes would, indeed, considerably lessen, but would by no
means wholly annihilate the climatic and geographical influences of the
forest, or ruinously diminish its value as a regular source of supply of fuel
and timber.
It is evidently a matter of the utmost importance that the public, and
especially land-owners, be roused to a sense of the dangers to which the
Page 414
indiscriminate clearing of the woods may expose not only future
generations, but the very soil itself. Some of the American States, as well as
the Governments of many European colonies, still retain the ownership of
great tracts of primitive woodland. The State of New York, for example,
has, in its north-eastern counties, a vast extent of territory in which the
lumberman has only here and there established his camp, and where the
forest, though interspersed with permanent settlements, robbed of some of
its finest pine groves, and often ravaged by devastating fires, still covers far
the largest proportion of the surface. Through this territory the soil is
generally poor, and even the new clearings have little of the luxuriance of
harvest which distinguishes them elsewhere. The value of the land for
agricultural uses is therefore very small, and few purchases are made for
any other purpose than to strip the soil of its timber. It has been often
proposed that the State should declare the remaining forest the inalienable
property of the commonwealth, but I believe the motive of the suggestion
has originated rather in poetical than in economical views of the subject.
Both these classes of considerations have a real worth. It is desirable that
some large and easily accessible region of American soil should remain, as
far as possible, in its primitive condition, at once a museum for the
instruction of the student, a garden for the recreation of the lover of nature,
and an asylum where indigenous tree, and humble plant that loves the
shade, and fish and fowl and four-footed beast, may dwell and perpetuate
their kind, in the enjoyment of such imperfect protection as the laws of a
people jealous of restraint can afford them. The immediate loss to the public
treasury from the adoption of this policy would be inconsiderable, for these
lands are sold at low rates. The forest alone, economically managed, would,
without injury, and even with benefit to its permanence and growth, soon
yield a regular income larger than the present value of the fee.
The collateral advantages of the preservation of these forests would be
far greater. Nature threw up those mountains and clothed them with lofty
generations, but the very soil itself. Some of the American States, as well as
the Governments of many European colonies, still retain the ownership of
great tracts of primitive woodland. The State of New York, for example,
has, in its north-eastern counties, a vast extent of territory in which the
lumberman has only here and there established his camp, and where the
forest, though interspersed with permanent settlements, robbed of some of
its finest pine groves, and often ravaged by devastating fires, still covers far
the largest proportion of the surface. Through this territory the soil is
generally poor, and even the new clearings have little of the luxuriance of
harvest which distinguishes them elsewhere. The value of the land for
agricultural uses is therefore very small, and few purchases are made for
any other purpose than to strip the soil of its timber. It has been often
proposed that the State should declare the remaining forest the inalienable
property of the commonwealth, but I believe the motive of the suggestion
has originated rather in poetical than in economical views of the subject.
Both these classes of considerations have a real worth. It is desirable that
some large and easily accessible region of American soil should remain, as
far as possible, in its primitive condition, at once a museum for the
instruction of the student, a garden for the recreation of the lover of nature,
and an asylum where indigenous tree, and humble plant that loves the
shade, and fish and fowl and four-footed beast, may dwell and perpetuate
their kind, in the enjoyment of such imperfect protection as the laws of a
people jealous of restraint can afford them. The immediate loss to the public
treasury from the adoption of this policy would be inconsiderable, for these
lands are sold at low rates. The forest alone, economically managed, would,
without injury, and even with benefit to its permanence and growth, soon
yield a regular income larger than the present value of the fee.
The collateral advantages of the preservation of these forests would be
far greater. Nature threw up those mountains and clothed them with lofty
Page 415
woods, that they might serve as a reservoir to supply with perennial waters
the thousand rivers and rills that are fed by the rains and snows of the
Adirondacks, and as a screen for the fertile plains of the central counties
against the chilling blasts of the north wind, which meet no other barrier in
their sweep from the Arctic pole. The climate of Northern New York even
now presents greater extremes of temperature than that of Southern France.
The long-continued cold of winter is more intense, the short heats of
summer even fiercer than in Provence, and hence the preservation of every
influence that tends to maintain an equilibrium of temperature and humidity
is of cardinal importance. The felling of the Adirondack woods would
ultimately involve for Northern and Central New York consequences
similar to those which have resulted from the laying bare of the southern
and western declivities of the French Alps and the spurs, ridges, and
detached peaks in front of them.
It is true that the evils to be apprehended from the clearing of the
mountains of New York may be less in degree than those which a similar
cause has produced in Southern France, where the intensity of its action has
been increased by the inclination of the mountain declivities, and by the
peculiar geological constitution of the earth. The degradation of the soil is,
perhaps, not equally promoted by a combination of the same circumstances,
in any of the American Atlantic States, but still they have rapid slopes and
loose and friable soils enough to render widespread desolation certain, if the
further destruction of the woods is not soon arrested. The effects of clearing
are already perceptible in the comparatively unviolated region of which I
am speaking. The rivers which rise in it flow with diminished currents in
dry seasons, and with augmented volumes of water after heavy rains. They
bring down larger quantities of sediment, and the increasing obstructions to
the navigation of the Hudson, which are extending themselves down the
channel in proportion as the fields are encroaching upon the forest, give
good grounds for the fear of irreparable injury to the commerce of the
the thousand rivers and rills that are fed by the rains and snows of the
Adirondacks, and as a screen for the fertile plains of the central counties
against the chilling blasts of the north wind, which meet no other barrier in
their sweep from the Arctic pole. The climate of Northern New York even
now presents greater extremes of temperature than that of Southern France.
The long-continued cold of winter is more intense, the short heats of
summer even fiercer than in Provence, and hence the preservation of every
influence that tends to maintain an equilibrium of temperature and humidity
is of cardinal importance. The felling of the Adirondack woods would
ultimately involve for Northern and Central New York consequences
similar to those which have resulted from the laying bare of the southern
and western declivities of the French Alps and the spurs, ridges, and
detached peaks in front of them.
It is true that the evils to be apprehended from the clearing of the
mountains of New York may be less in degree than those which a similar
cause has produced in Southern France, where the intensity of its action has
been increased by the inclination of the mountain declivities, and by the
peculiar geological constitution of the earth. The degradation of the soil is,
perhaps, not equally promoted by a combination of the same circumstances,
in any of the American Atlantic States, but still they have rapid slopes and
loose and friable soils enough to render widespread desolation certain, if the
further destruction of the woods is not soon arrested. The effects of clearing
are already perceptible in the comparatively unviolated region of which I
am speaking. The rivers which rise in it flow with diminished currents in
dry seasons, and with augmented volumes of water after heavy rains. They
bring down larger quantities of sediment, and the increasing obstructions to
the navigation of the Hudson, which are extending themselves down the
channel in proportion as the fields are encroaching upon the forest, give
good grounds for the fear of irreparable injury to the commerce of the
Page 416
important towns on the upper waters of that river, unless measures are taken
to prevent the expansion of "improvements" which have already been
carried beyond the demands of a wise economy.
In the Eastern United States the general character of the climate, soil, and
surface is such, that for the formation of very destructive torrents a much
longer time is required than would be necessary in the mountainous
provinces of Italy or of France. But the work of desolation has begun even
there, and wherever a rapid mountain-slope has been stripped of wood,
incipient ravines already plough the surface, and collect the precipitation in
channels which threaten serious mischief in the future. There is a peculiar
action of this sort on the sandy surface of pine-forests and in other soils that
unite readily with water, which has excited the attention of geographers and
geologists. Soils of the first kind are found in all the Eastern States; those of
the second are more frequent in the exhausted counties of Maryland, where
tobacco is cultivated, and in the more southern territories of Georgia and
Alabama. In these localities the ravines which appear after the cutting of the
forest, through some accidental disturbance of the surface, or, in some
formations, through the cracking of the soil in consequence of great drought
or heat, enlarge and extend themselves with fearful rapidity.
In Georgia and in Alabama, Lyell saw "the beginning of the formation of
hundreds of valleys in places where the primitive forest had been recently
cut down." One of these, in Georgia, in a soil composed of clay and sand
produced by the decomposition in situ of hornblendic gneiss with layers and
veins of quartz, "and which did not exist before the felling of the forest
twenty years previous," he describes as more than 55 feet in depth, 300
yards in length, and from 20 to 180 feet in breadth. Our author refers to
other cases in the same States, "where the cutting down of the trees, which
had prevented the rain from collecting into torrents and running off in
sudden land-floods, has given rise to ravines from 70 to 80 feet deep."
to prevent the expansion of "improvements" which have already been
carried beyond the demands of a wise economy.
In the Eastern United States the general character of the climate, soil, and
surface is such, that for the formation of very destructive torrents a much
longer time is required than would be necessary in the mountainous
provinces of Italy or of France. But the work of desolation has begun even
there, and wherever a rapid mountain-slope has been stripped of wood,
incipient ravines already plough the surface, and collect the precipitation in
channels which threaten serious mischief in the future. There is a peculiar
action of this sort on the sandy surface of pine-forests and in other soils that
unite readily with water, which has excited the attention of geographers and
geologists. Soils of the first kind are found in all the Eastern States; those of
the second are more frequent in the exhausted counties of Maryland, where
tobacco is cultivated, and in the more southern territories of Georgia and
Alabama. In these localities the ravines which appear after the cutting of the
forest, through some accidental disturbance of the surface, or, in some
formations, through the cracking of the soil in consequence of great drought
or heat, enlarge and extend themselves with fearful rapidity.
In Georgia and in Alabama, Lyell saw "the beginning of the formation of
hundreds of valleys in places where the primitive forest had been recently
cut down." One of these, in Georgia, in a soil composed of clay and sand
produced by the decomposition in situ of hornblendic gneiss with layers and
veins of quartz, "and which did not exist before the felling of the forest
twenty years previous," he describes as more than 55 feet in depth, 300
yards in length, and from 20 to 180 feet in breadth. Our author refers to
other cases in the same States, "where the cutting down of the trees, which
had prevented the rain from collecting into torrents and running off in
sudden land-floods, has given rise to ravines from 70 to 80 feet deep."
Page 417
[Footnote: Lyell, Principles of Geology, 10th ed., vol i., 345-6.] Similar
results often follow in the North-eastern States from cutting the timber on
the "pine plains," where the soil is usually of a sandy composition and loose
texture.
American Forest-Trees.
The remaining forests of the Northern States and of Canada no longer
boast the mighty pines which almost rivalled the gigantic sequoia and
redwood of California; and the growth of the larger forest-trees is so slow,
after they have attained to a certain size, that if every pine and oak were
spared for two centuries, the largest now standing would not reach the
stature of hundreds recorded to have been cut within two or three
generations. [Footnote: The growth of the white pine, on good soil and in
open ground, is rather rapid until it reaches the diameter of a couple of feet,
after which it is much slower. The favorite habitat of this tree is light, sandy
earth. On this soil, and in a dense wood, it requires a century to attain the
diameter of a yard. Emerson (Trees of Massachusetts, p. 65), says that a
pine of this species, near Paris, "thirty years planted, is eighty feet high,
with a diameter of three feet." He also states that ten white pines planted at
Cambridge, Massachusetts in 1809 or 1810, exhibited, in the winter of 1841
and 1842, an average of twenty inches diameter at the ground, the two
largest measuring, at the height of three feet, four feet eight inches in
circumference; and he mentions another pine growing in a rocky swamp,
which at the age of thirty-two years, "gave seven feet in circumference at
the but, with a height of sixty-two feet six inches." This latter I suppose to
be a seedling, the others TRANSPLANTED trees, which might have been
some years old when placed where they finally grew.
The following case came under my own observation: In 1824 a pine-tree,
so small that a young lady, with the help of a lad, took it up from the ground
results often follow in the North-eastern States from cutting the timber on
the "pine plains," where the soil is usually of a sandy composition and loose
texture.
American Forest-Trees.
The remaining forests of the Northern States and of Canada no longer
boast the mighty pines which almost rivalled the gigantic sequoia and
redwood of California; and the growth of the larger forest-trees is so slow,
after they have attained to a certain size, that if every pine and oak were
spared for two centuries, the largest now standing would not reach the
stature of hundreds recorded to have been cut within two or three
generations. [Footnote: The growth of the white pine, on good soil and in
open ground, is rather rapid until it reaches the diameter of a couple of feet,
after which it is much slower. The favorite habitat of this tree is light, sandy
earth. On this soil, and in a dense wood, it requires a century to attain the
diameter of a yard. Emerson (Trees of Massachusetts, p. 65), says that a
pine of this species, near Paris, "thirty years planted, is eighty feet high,
with a diameter of three feet." He also states that ten white pines planted at
Cambridge, Massachusetts in 1809 or 1810, exhibited, in the winter of 1841
and 1842, an average of twenty inches diameter at the ground, the two
largest measuring, at the height of three feet, four feet eight inches in
circumference; and he mentions another pine growing in a rocky swamp,
which at the age of thirty-two years, "gave seven feet in circumference at
the but, with a height of sixty-two feet six inches." This latter I suppose to
be a seedling, the others TRANSPLANTED trees, which might have been
some years old when placed where they finally grew.
The following case came under my own observation: In 1824 a pine-tree,
so small that a young lady, with the help of a lad, took it up from the ground
Page 418
and carried it a quarter of a mile, was planted near a house in a town in
Vermont. It was occasionally watered, but received no other special
treatment. I measured this tree in 1860, and found it, at four feet from the
ground, and entirely above the spread of the roots, two feet and four inches
in diameter. A new measurement in 1871 gave a diameter of two feet eight
inches, being an increase of four inches in eleven years, a slower rate than
that of preceding years. It could not have been more than three inches
through when transplanted, and up to 1860 must have increased its diameter
at the rate of about seven-tenths of an inch per year, almost double its later
growth. In 1871 the crown had a diameter of 63 feet.
In the same neighborhood, elms transplanted in 1803, when they were
not above three or four inches through, had attained, in 1871, a diameter of
from four feet to four feet two inches, with a spread of crown of from 90 to
112 feet. Sugar-maples, transplanted in 1822, at about the same size,
measured two feet three inches through. This growth undoubtedly
considerably exceeds that of trees of the same species in the natural forest,
though the transplanted trees had received no other fertilizing application
than an unlimited supply of light and air.] Dr. Williams, who wrote about
sixty years ago, states the following as the dimensions of "such trees as are
esteemed large ones of their kind in that part of America" [Vermont],
qualifying his account with the remark that his measurements "do not
denote the greatest which nature has produced of their particular species,
but the greatest which are to be found in most of our towns."
Diameter. Height.
Pine………. 6 feet, 247 feet.
Maple……… 5 " 9 inches \
Buttonwood…. 5 " 6 " |
Elm……….. 5 " |
Hemlock……. 4 " 9 " |
Vermont. It was occasionally watered, but received no other special
treatment. I measured this tree in 1860, and found it, at four feet from the
ground, and entirely above the spread of the roots, two feet and four inches
in diameter. A new measurement in 1871 gave a diameter of two feet eight
inches, being an increase of four inches in eleven years, a slower rate than
that of preceding years. It could not have been more than three inches
through when transplanted, and up to 1860 must have increased its diameter
at the rate of about seven-tenths of an inch per year, almost double its later
growth. In 1871 the crown had a diameter of 63 feet.
In the same neighborhood, elms transplanted in 1803, when they were
not above three or four inches through, had attained, in 1871, a diameter of
from four feet to four feet two inches, with a spread of crown of from 90 to
112 feet. Sugar-maples, transplanted in 1822, at about the same size,
measured two feet three inches through. This growth undoubtedly
considerably exceeds that of trees of the same species in the natural forest,
though the transplanted trees had received no other fertilizing application
than an unlimited supply of light and air.] Dr. Williams, who wrote about
sixty years ago, states the following as the dimensions of "such trees as are
esteemed large ones of their kind in that part of America" [Vermont],
qualifying his account with the remark that his measurements "do not
denote the greatest which nature has produced of their particular species,
but the greatest which are to be found in most of our towns."
Diameter. Height.
Pine………. 6 feet, 247 feet.
Maple……… 5 " 9 inches \
Buttonwood…. 5 " 6 " |
Elm……….. 5 " |
Hemlock……. 4 " 9 " |
Page 419
Oak……….. 4 " > From 100 to 200 feet.
Basswood…… 4 " |
Ash……….. 4 " |
Birch……… 4 " /
He adds a note saying that a white pine was cut in Dunstable, New
Hampshire, in the year 1736, the diameter of which was seven feet and
eight inches. Dr. Dwight says that a fallen pine in Connecticut was found to
measure two hundred and forty-seven feet in height, and adds: "A few years
since, such trees were in great numbers along the northern parts of
Connecticut River." In another letter, he speaks of the white pine as
"frequently six feet in diameter, and two hundred and fifty feet in height,"
and states that a pine had been cut in Lancaster, New Hampshire, which
measured two hundred and sixty-four feet, Emerson wrote in 1846: "Fifty
years ago, several trees growing on rather dry land in Blandford,
Massachusetts, measured, after they were felled, two hundred and twenty-
three feet." All these trees are surpassed by a pine felled at Hanover, New
Hampshire, about a hundred years ago, and described as measuring two
hundred and seventy-four feet. [Footnote: Williams, History of Vermont, ii.,
p. 53. Dwight s Travels, iv., p. 21, and iii, p. 36. Emerson, Trees of
Massachusetts, p. 61. Parish, Life of President Wheelock, p. 56.] These
descriptions, it will be noticed, apply to trees cut from seventy to one
hundred and forty years since.
Persons, whom observation has rendered familiar with the present
character of the American forest, will be struck with the smallness of the
diameter which Dr. Williams and Dr. Dwight ascribe to trees of such
extraordinary height. Individuals of the several species mentioned in Dr.
Williams's table are now hardly to be found in the same climate, exceeding
one-half or at most two-thirds of the height which he assigns to them; but,
except in the case of the oak and the pine, the diameter stated by him would
Basswood…… 4 " |
Ash……….. 4 " |
Birch……… 4 " /
He adds a note saying that a white pine was cut in Dunstable, New
Hampshire, in the year 1736, the diameter of which was seven feet and
eight inches. Dr. Dwight says that a fallen pine in Connecticut was found to
measure two hundred and forty-seven feet in height, and adds: "A few years
since, such trees were in great numbers along the northern parts of
Connecticut River." In another letter, he speaks of the white pine as
"frequently six feet in diameter, and two hundred and fifty feet in height,"
and states that a pine had been cut in Lancaster, New Hampshire, which
measured two hundred and sixty-four feet, Emerson wrote in 1846: "Fifty
years ago, several trees growing on rather dry land in Blandford,
Massachusetts, measured, after they were felled, two hundred and twenty-
three feet." All these trees are surpassed by a pine felled at Hanover, New
Hampshire, about a hundred years ago, and described as measuring two
hundred and seventy-four feet. [Footnote: Williams, History of Vermont, ii.,
p. 53. Dwight s Travels, iv., p. 21, and iii, p. 36. Emerson, Trees of
Massachusetts, p. 61. Parish, Life of President Wheelock, p. 56.] These
descriptions, it will be noticed, apply to trees cut from seventy to one
hundred and forty years since.
Persons, whom observation has rendered familiar with the present
character of the American forest, will be struck with the smallness of the
diameter which Dr. Williams and Dr. Dwight ascribe to trees of such
extraordinary height. Individuals of the several species mentioned in Dr.
Williams's table are now hardly to be found in the same climate, exceeding
one-half or at most two-thirds of the height which he assigns to them; but,
except in the case of the oak and the pine, the diameter stated by him would
Page 420
not be thought very extraordinary in trees of far less height, now standing.
Even in the species I have excepted, those diameters, with half the heights
of Dr. Williams, might perhaps be paralleled at the present time; and many
elms, transplanted, at a diameter of six inches, within the memory of
persons still living, measure four and sometimes even five feet through. For
this change in the growth of forest-trees there are two reasons: the one is,
that the great commercial value of the pine and the oak have caused the
destruction of all the best—that is, the tallest and straightest— specimens of
both; the other, that the thinning of the woods by the axe of the lumberman
has allowed the access of light and heat and air to trees of humbler worth
and lower stature, which have survived their more towering brethren.
These, consequently, have been able to expand their crowns and swell their
stems to a degree not possible so long as they were overshadowed and
stifled by the lordly oak and pine. While, therefore, the New England
forester must search long before he finds a pine fit to be the mast Of some
great ammiral, beeches and elms and birches, as sturdy as the mightiest of
their progenitors, are still no rarity.
[Footnote: The forest-trees of the Northern States do not attain to extreme
longevity in the dense woods. Dr. Williams found that none of the huge
pines, the age of which he ascertained, exceeded three hundred and fifty or
four hundred years, though he quotes a friend who thought he had noticed
trees considerably older. The oak lives longer than the pine, and the
hemlock-spruce is perhaps equally long lived. A tree of this latter species,
cut within my knowledge in a thick wood, counted four hundred and eighty-
six, or, according to another observer, five hundred annual circles. Great
luxuriance of animal and vegetable production is not commonly
accompanied by long duration of the individual. The oldest men are not
found in the crowded city; and in the tropics, where life is prolific and
precocious, it is also short. The most ancient forest-trees of which we have
accounts have not been those growing in thick woods, but isolated
Even in the species I have excepted, those diameters, with half the heights
of Dr. Williams, might perhaps be paralleled at the present time; and many
elms, transplanted, at a diameter of six inches, within the memory of
persons still living, measure four and sometimes even five feet through. For
this change in the growth of forest-trees there are two reasons: the one is,
that the great commercial value of the pine and the oak have caused the
destruction of all the best—that is, the tallest and straightest— specimens of
both; the other, that the thinning of the woods by the axe of the lumberman
has allowed the access of light and heat and air to trees of humbler worth
and lower stature, which have survived their more towering brethren.
These, consequently, have been able to expand their crowns and swell their
stems to a degree not possible so long as they were overshadowed and
stifled by the lordly oak and pine. While, therefore, the New England
forester must search long before he finds a pine fit to be the mast Of some
great ammiral, beeches and elms and birches, as sturdy as the mightiest of
their progenitors, are still no rarity.
[Footnote: The forest-trees of the Northern States do not attain to extreme
longevity in the dense woods. Dr. Williams found that none of the huge
pines, the age of which he ascertained, exceeded three hundred and fifty or
four hundred years, though he quotes a friend who thought he had noticed
trees considerably older. The oak lives longer than the pine, and the
hemlock-spruce is perhaps equally long lived. A tree of this latter species,
cut within my knowledge in a thick wood, counted four hundred and eighty-
six, or, according to another observer, five hundred annual circles. Great
luxuriance of animal and vegetable production is not commonly
accompanied by long duration of the individual. The oldest men are not
found in the crowded city; and in the tropics, where life is prolific and
precocious, it is also short. The most ancient forest-trees of which we have
accounts have not been those growing in thick woods, but isolated
Page 421
specimens, with no taller neighbor to intercept the light and heat and air,
and no rival to share the nutriment afforded by the soil. The more rapid
growth and greater dimensions of trees standing near the boundary of the
forest, are matters of familiar observation. "Long experience has shown that
trees growing on the confines of the wood may be cut at sixty years of age
as advantageously as others of the same species, reared in the depth of the
forest, at a hundred and twenty. We have often remarked, in our Alps, that
the trunk of trees upon the border of a grove is most developed or enlarged
upon the outer or open side, where the branches extend themselves farthest,
while the concentric circles of growth are most uniform in those entirely
surrounded by other trees, or standing entirely alone."—A. and G. Villa,
Necessita dei Boschi pp. 17, 18.]
California fortunately still preserves her magnificent sequoias, which rise
to the height of three hundred feet, and sometimes, as we are assured, even
to three hundred and sixty and four hundred feet, and she has also pines and
cedars of scarcely inferior dimensions. The public being now convinced of
the importance of preserving these colossal trees, it is very probable that the
fear of their total destruction may prove groundless, and we may still hope
that some of them may survive even till that distant future when the skill of
the forester shall have raised from their seeds a progeny as lofty and as
majestic as those which now exist. [Footnote: California must surrender to
Australia the glory of possessing the tallest trees. According to Dr. Mueller,
Director of the Government Botanic Garden at Melbourne, a Eucalyptus,
near Healesville, measured 480 feet in height. Later accounts speak of trees
of the same species fully 500 feet in height. See Schleiden, Fur Baum und
Wald, p. 21.
If we may credit late reports, the growth of the eucalyptus is so rapid in
California, that the child is perhaps now born who will see the tallest
sequoia overtopped by this new vegetable emigrant from Australia.]
and no rival to share the nutriment afforded by the soil. The more rapid
growth and greater dimensions of trees standing near the boundary of the
forest, are matters of familiar observation. "Long experience has shown that
trees growing on the confines of the wood may be cut at sixty years of age
as advantageously as others of the same species, reared in the depth of the
forest, at a hundred and twenty. We have often remarked, in our Alps, that
the trunk of trees upon the border of a grove is most developed or enlarged
upon the outer or open side, where the branches extend themselves farthest,
while the concentric circles of growth are most uniform in those entirely
surrounded by other trees, or standing entirely alone."—A. and G. Villa,
Necessita dei Boschi pp. 17, 18.]
California fortunately still preserves her magnificent sequoias, which rise
to the height of three hundred feet, and sometimes, as we are assured, even
to three hundred and sixty and four hundred feet, and she has also pines and
cedars of scarcely inferior dimensions. The public being now convinced of
the importance of preserving these colossal trees, it is very probable that the
fear of their total destruction may prove groundless, and we may still hope
that some of them may survive even till that distant future when the skill of
the forester shall have raised from their seeds a progeny as lofty and as
majestic as those which now exist. [Footnote: California must surrender to
Australia the glory of possessing the tallest trees. According to Dr. Mueller,
Director of the Government Botanic Garden at Melbourne, a Eucalyptus,
near Healesville, measured 480 feet in height. Later accounts speak of trees
of the same species fully 500 feet in height. See Schleiden, Fur Baum und
Wald, p. 21.
If we may credit late reports, the growth of the eucalyptus is so rapid in
California, that the child is perhaps now born who will see the tallest
sequoia overtopped by this new vegetable emigrant from Australia.]
Page 422
European and American Trees compared.
The woods of North America are strikingly distinguished from those of
Europe by the vastly greater variety of species they contain. According to
Clave, there are in "France and in most parts of Europe only about twenty
forest-trees, five or six of which are spike-leaved and resinous, the
remainder broad-leaved." [Footnote: Etudes Forestieres, p. 7.] Our author,
however, doubtless means genera, though he uses the word especes.
Rossmassler enumerates fifty-seven species of forest-trees as found in
Germany, but some of these are mere shrubs, some are fruit and properly
garden trees, and some others are only varieties of familiar species. The
valuable manual of Parade describes about the same number, including,
however, two of American origin—the locust, Robinia pseudacacia, and the
Weymouth or white pine, Pinus Strobus—and the cedar of Lebanon from
Asia, which, or at least a very closely allied species, is indigenous in
Algeria also. We may then safely say that Europe does not possess above
forty or fifty native trees of such economical value as to be worth the
special care of the forester, while the oak alone numbers more than thirty
species in the United States, [Footnote: For full catalogues of American
forest-trees, and remarks on their geographical distribution, consult papers
on the subject by Dr. J. G. Cooper, in the Report of the Smithsonian
Institution for 1858, and the Report of the United States Patent Office,
Agricultural Division, for 1860.] and some other North American genera
are almost equally diversified. [Footnote: Although Spenser's catalogue of
trees occurs in the first canto of the first book of the "Faery Queene"—the
only canto of that exquisite poem actually read by most students of English
literature—it is not so generally familiar as to make the quotation of it
altogether superfluous:
VII.
The woods of North America are strikingly distinguished from those of
Europe by the vastly greater variety of species they contain. According to
Clave, there are in "France and in most parts of Europe only about twenty
forest-trees, five or six of which are spike-leaved and resinous, the
remainder broad-leaved." [Footnote: Etudes Forestieres, p. 7.] Our author,
however, doubtless means genera, though he uses the word especes.
Rossmassler enumerates fifty-seven species of forest-trees as found in
Germany, but some of these are mere shrubs, some are fruit and properly
garden trees, and some others are only varieties of familiar species. The
valuable manual of Parade describes about the same number, including,
however, two of American origin—the locust, Robinia pseudacacia, and the
Weymouth or white pine, Pinus Strobus—and the cedar of Lebanon from
Asia, which, or at least a very closely allied species, is indigenous in
Algeria also. We may then safely say that Europe does not possess above
forty or fifty native trees of such economical value as to be worth the
special care of the forester, while the oak alone numbers more than thirty
species in the United States, [Footnote: For full catalogues of American
forest-trees, and remarks on their geographical distribution, consult papers
on the subject by Dr. J. G. Cooper, in the Report of the Smithsonian
Institution for 1858, and the Report of the United States Patent Office,
Agricultural Division, for 1860.] and some other North American genera
are almost equally diversified. [Footnote: Although Spenser's catalogue of
trees occurs in the first canto of the first book of the "Faery Queene"—the
only canto of that exquisite poem actually read by most students of English
literature—it is not so generally familiar as to make the quotation of it
altogether superfluous:
VII.
Page 423
Enforst to seeke some covert nigh at hand,
A shadic grove not farr away they spide,
That promist ayde the tempest to withstand;
Whose loftie trees, yclad with sommers pride,
Did spred so broad, that heavens light did hide,
Not perceable with power of any starr:
And all within were pathes and alleies wide,
With footing worne, and leading inward farr;
Faire harbour that them seems; so in they entered ar.
VIII.
And foorth they passe, with pleasure forward led,
Joying to heare the birdes sweete harmony.
Which therein shrouded from the tempest dred,
Seemd in their song to scorne the cruell sky.
Much can they praise the trees so straight and hy,
The sayling pine; the cedar stout and tall;
The vine-propp elm; the poplar never dry;
The builder oake, sole king of forrests all;
The aspine good for staves; the cypresse funerall;
IX.
The laurell, meed of mightie conquerours
And poets sage; the firre that weepeth still;
The willow, worne of forlorn paramours;
The eugh, obedient to the benders will;
The birch for shaftes; the sallow for the mill;
The mirrhe sweete-bleeding in the bitter wound;
A shadic grove not farr away they spide,
That promist ayde the tempest to withstand;
Whose loftie trees, yclad with sommers pride,
Did spred so broad, that heavens light did hide,
Not perceable with power of any starr:
And all within were pathes and alleies wide,
With footing worne, and leading inward farr;
Faire harbour that them seems; so in they entered ar.
VIII.
And foorth they passe, with pleasure forward led,
Joying to heare the birdes sweete harmony.
Which therein shrouded from the tempest dred,
Seemd in their song to scorne the cruell sky.
Much can they praise the trees so straight and hy,
The sayling pine; the cedar stout and tall;
The vine-propp elm; the poplar never dry;
The builder oake, sole king of forrests all;
The aspine good for staves; the cypresse funerall;
IX.
The laurell, meed of mightie conquerours
And poets sage; the firre that weepeth still;
The willow, worne of forlorn paramours;
The eugh, obedient to the benders will;
The birch for shaftes; the sallow for the mill;
The mirrhe sweete-bleeding in the bitter wound;
Page 424
The warlike beech; the ash for nothing ill;
The fruitfull olive; and the platane round;
The carver holme; the maple seeldom inward sound.
Although the number of SPECIES of American forest-trees is much
larger than of European, yet the distinguishable VARIETIES are relatively
more numerous in the Old World, even in the case of trees not generally
receiving special care. This multiplication of varieties is no doubt a result,
though not a foreseen or intended one, of human action; for the ordinary
operations of European forest economy expose young trees to different
conditions from those presented by nature, and new conditions produce new
forms. All European woods, except in the remote North, even if not
technically artificial forests, acquire a more or less artificial character from
the governing hand of man, and the effect of this interference is seen in the
constant deviation of trees from the original type. The holly, for example,
even when growing as absolutely wild as any tree can ever grow in
countries long occupied by man, produces numerous varieties, and twenty
or thirty such, not to mention intermediate shades, are described and named
as recognizably different, in treatises on the forest-trees of Europe.]
While the American forest flora has made large contributions to that of
Europe, comparatively few European trees have been naturalized in the
United States, and as a general rule the indigenous trees of Europe do not
succeed well in our climate. The European mountain-ash—which in beauty,
dimensions, and healthfulness of growth is superior to our own [Footnote:
In the Northern Tyrol mountain-ashes fifteen inches in diameter are not
uncommon. The berries are distilled with grain to flavor the spirit.]—the
horse-chestnut, and the abele, or silver poplar, are valuable additions to the
ornamental trees of North America. The Swiss arve or zirbelkiefer, Pinus
cembra, which yields a well-flavored edible seed and furnishes excellent
wood for carving, the umbrella-pine, [Footnote: The mountain ranges of our
The fruitfull olive; and the platane round;
The carver holme; the maple seeldom inward sound.
Although the number of SPECIES of American forest-trees is much
larger than of European, yet the distinguishable VARIETIES are relatively
more numerous in the Old World, even in the case of trees not generally
receiving special care. This multiplication of varieties is no doubt a result,
though not a foreseen or intended one, of human action; for the ordinary
operations of European forest economy expose young trees to different
conditions from those presented by nature, and new conditions produce new
forms. All European woods, except in the remote North, even if not
technically artificial forests, acquire a more or less artificial character from
the governing hand of man, and the effect of this interference is seen in the
constant deviation of trees from the original type. The holly, for example,
even when growing as absolutely wild as any tree can ever grow in
countries long occupied by man, produces numerous varieties, and twenty
or thirty such, not to mention intermediate shades, are described and named
as recognizably different, in treatises on the forest-trees of Europe.]
While the American forest flora has made large contributions to that of
Europe, comparatively few European trees have been naturalized in the
United States, and as a general rule the indigenous trees of Europe do not
succeed well in our climate. The European mountain-ash—which in beauty,
dimensions, and healthfulness of growth is superior to our own [Footnote:
In the Northern Tyrol mountain-ashes fifteen inches in diameter are not
uncommon. The berries are distilled with grain to flavor the spirit.]—the
horse-chestnut, and the abele, or silver poplar, are valuable additions to the
ornamental trees of North America. The Swiss arve or zirbelkiefer, Pinus
cembra, which yields a well-flavored edible seed and furnishes excellent
wood for carving, the umbrella-pine, [Footnote: The mountain ranges of our
Page 425
extreme West produce a pine closely resembling the European umbrella-
pine.] which also bears a seed agreeable to the taste, and which, from the
color of its foliage and the beautiful form of its dome-like crown, is among
the most elegant of trees, the white birch of Central Europe, with its
pendulous branches almost rivalling those of the weeping willow in length,
flexibility, and gracefulness of fall, and, especially, the "cypresse funerall,"
might be introduced into the United States with great advantage to the
landscape. The European beech and chestnut furnish timber of far better
quality than that of their American congeners. The fruit of the European
chestnut, though inferior to the American in sweetness and flavor, is larger,
and is an important article of diet among the French and Italian peasantry.
The walnut of Europe, though not equal to some of the American species in
beauty of growth or of wood, or to others in strength and elasticity of fibre,
is valuable for its timber and its oil. [Footnote: The walnut is a more
valuable tree than is generally supposed. It yields one-third of the oil
produced in France, and in this respect occupies an intermediate position
between the olive of the south and the oleaginous seeds of the north. A
hectare (about two and a half acres) will produce nuts to the value of five
hundred francs a year, which cost nothing but the gathering. Unfortunately,
its maturity must be long waited for, and more nut-trees are felled than
planted. The demand for its wood in cabinet-work is the principal cause of
its destruction. See Lavergne, Economie Rurale de la France, p. 253.
According to Cosimo Ridolfi (Lezioni Orali, ii., p. 424), France obtains
three times as much oil from the walnut as from the olive, and nearly as
much as from all oleaginous seeds together. He states that the walnut bears
nuts at the age of twenty years, and yields its maximum product at seventy,
and that a hectare of ground, with thirty trees, or twelve to the acre, is equal
to a capital of twenty-five hundred francs.
pine.] which also bears a seed agreeable to the taste, and which, from the
color of its foliage and the beautiful form of its dome-like crown, is among
the most elegant of trees, the white birch of Central Europe, with its
pendulous branches almost rivalling those of the weeping willow in length,
flexibility, and gracefulness of fall, and, especially, the "cypresse funerall,"
might be introduced into the United States with great advantage to the
landscape. The European beech and chestnut furnish timber of far better
quality than that of their American congeners. The fruit of the European
chestnut, though inferior to the American in sweetness and flavor, is larger,
and is an important article of diet among the French and Italian peasantry.
The walnut of Europe, though not equal to some of the American species in
beauty of growth or of wood, or to others in strength and elasticity of fibre,
is valuable for its timber and its oil. [Footnote: The walnut is a more
valuable tree than is generally supposed. It yields one-third of the oil
produced in France, and in this respect occupies an intermediate position
between the olive of the south and the oleaginous seeds of the north. A
hectare (about two and a half acres) will produce nuts to the value of five
hundred francs a year, which cost nothing but the gathering. Unfortunately,
its maturity must be long waited for, and more nut-trees are felled than
planted. The demand for its wood in cabinet-work is the principal cause of
its destruction. See Lavergne, Economie Rurale de la France, p. 253.
According to Cosimo Ridolfi (Lezioni Orali, ii., p. 424), France obtains
three times as much oil from the walnut as from the olive, and nearly as
much as from all oleaginous seeds together. He states that the walnut bears
nuts at the age of twenty years, and yields its maximum product at seventy,
and that a hectare of ground, with thirty trees, or twelve to the acre, is equal
to a capital of twenty-five hundred francs.
Page 426
The nut of this tree is known in the United States as the "English walnut."
The fruit and the wood much resemble those of the American black walnut,
Juglans nigra, but for cabinet-work the American is the more beautiful
material, especially when the large knots are employed. The timber or the
European species, when straight-grained, and clear, or free from knots, is,
for ordinary purposes, better than that of the American black walnut, but
bears no comparison with the wood of the hickory, when strength combined
with elasticity is required, and its nut is very inferior in taste to that of the
shagbark, as well as to the butternut, which it somewhat resembles.
"The chestnut is more valuable still, for it produces on a sterile soil,
which, without it, would yield only ferns and heaths, an abundant nutriment
for man."—Lavergne, Economie Rurale de la France, p. 253.
I believe the varieties developed by cultivation are less numerous in the
walnut than is the chestnut, which latter tree is often grafted in Southern
Europe.
The chestnut crop of France was estimated in 1848 at 3,478,000
hectolitres, or 9,877,520 Winchester bushels, and valued at 13,528,000
francs, or more than two million and a half dollars. In Tuscany the annual
yield is computed at about 550,000 bushels.
The Tuscan peasants think the flour of the dried chestnut not less
nutritious than Indian cornmeal, and it sells at the same price, or about three
cents per English pound, in the mountains, and four cents in the towns.] The
maritime pine, which has proved of such immense use in fixing drifting
sands in France, may perhaps be better adapted to this purpose than any of
the pines of the New World, and it is of great importance for its turpentine,
resin, and tar. The epicea, or common fir, Abies picea, Abies excelsa, Picea
excelsa, abundant in the mountains of France and the contiguous country, is
known for its product, Burgundy pitch, and, as it flourishes in a greater
The fruit and the wood much resemble those of the American black walnut,
Juglans nigra, but for cabinet-work the American is the more beautiful
material, especially when the large knots are employed. The timber or the
European species, when straight-grained, and clear, or free from knots, is,
for ordinary purposes, better than that of the American black walnut, but
bears no comparison with the wood of the hickory, when strength combined
with elasticity is required, and its nut is very inferior in taste to that of the
shagbark, as well as to the butternut, which it somewhat resembles.
"The chestnut is more valuable still, for it produces on a sterile soil,
which, without it, would yield only ferns and heaths, an abundant nutriment
for man."—Lavergne, Economie Rurale de la France, p. 253.
I believe the varieties developed by cultivation are less numerous in the
walnut than is the chestnut, which latter tree is often grafted in Southern
Europe.
The chestnut crop of France was estimated in 1848 at 3,478,000
hectolitres, or 9,877,520 Winchester bushels, and valued at 13,528,000
francs, or more than two million and a half dollars. In Tuscany the annual
yield is computed at about 550,000 bushels.
The Tuscan peasants think the flour of the dried chestnut not less
nutritious than Indian cornmeal, and it sells at the same price, or about three
cents per English pound, in the mountains, and four cents in the towns.] The
maritime pine, which has proved of such immense use in fixing drifting
sands in France, may perhaps be better adapted to this purpose than any of
the pines of the New World, and it is of great importance for its turpentine,
resin, and tar. The epicea, or common fir, Abies picea, Abies excelsa, Picea
excelsa, abundant in the mountains of France and the contiguous country, is
known for its product, Burgundy pitch, and, as it flourishes in a greater
Page 427
variety of soil and climate than almost any other spike-leaved tree, it might
be well worth transplantation. [Footnote: This fir is remarkable for its
tendency to cicatrize or heal over its stumps, a property which it possesses
in common with some other firs, the maritime pine, and the European larch.
When these trees grow in thick clumps, their roots are apt to unite by a
species of natural grafting, and if one of them be felled, although its own
proper rootlets die, the stump may continue, sometimes for a century, to
receive nourishment from the radicles of the surrounding trees, and a dome
of wood and bark of considerable thickness be formed over it. The healing
is, however, only apparent, for the entire stump, except the outside ring of
annual growth, soon dies, and even decays within its covering, without
sending out new shoots. See Monthly Report, Department of Agriculture,
for October, 1872.] The cork oak has been introduced into California and
some other parts of the United States, I believe, and would undoubtedly
thrive in the Southern section of the Union. [Footnote: At the age of twelve
or fifteen years, the cork-tree is stripped of its outer bark for the first time.
This first yield is of inferior quality, and it employed for floats for nets and
buoys, or burnt for lampblack. After this, a new layer of cork, an inch or an
inch and a quarter in thickness, is formed about one in ten years, and is
removed in large sheets without injury to the tree, which lives a hundred
and fifty years or more. According to Clave (p. 252), the annual product of
a forest of cork oaks is calculated at about 660 kilogrammes, worth 150
frances, to the hectare, which, deducting expenses, leaves a profit of 100
francs. This is about equal to 250 pound weight, and eight dollars profit to
the acre. The cork oaks of the national domain in Algeria cover about
500,000 acres, and are let to individuals at rates which are expected, when
the whole is rented, to yield to the state revenue of about $2,000,000.
George Sand, in the Histoire de ma Vie, speaks of the cork-forests in
Southern France as among the most profitable of rural possessions, and
states, what I do not remember to have seen noticed elsewhere, that Russia
be well worth transplantation. [Footnote: This fir is remarkable for its
tendency to cicatrize or heal over its stumps, a property which it possesses
in common with some other firs, the maritime pine, and the European larch.
When these trees grow in thick clumps, their roots are apt to unite by a
species of natural grafting, and if one of them be felled, although its own
proper rootlets die, the stump may continue, sometimes for a century, to
receive nourishment from the radicles of the surrounding trees, and a dome
of wood and bark of considerable thickness be formed over it. The healing
is, however, only apparent, for the entire stump, except the outside ring of
annual growth, soon dies, and even decays within its covering, without
sending out new shoots. See Monthly Report, Department of Agriculture,
for October, 1872.] The cork oak has been introduced into California and
some other parts of the United States, I believe, and would undoubtedly
thrive in the Southern section of the Union. [Footnote: At the age of twelve
or fifteen years, the cork-tree is stripped of its outer bark for the first time.
This first yield is of inferior quality, and it employed for floats for nets and
buoys, or burnt for lampblack. After this, a new layer of cork, an inch or an
inch and a quarter in thickness, is formed about one in ten years, and is
removed in large sheets without injury to the tree, which lives a hundred
and fifty years or more. According to Clave (p. 252), the annual product of
a forest of cork oaks is calculated at about 660 kilogrammes, worth 150
frances, to the hectare, which, deducting expenses, leaves a profit of 100
francs. This is about equal to 250 pound weight, and eight dollars profit to
the acre. The cork oaks of the national domain in Algeria cover about
500,000 acres, and are let to individuals at rates which are expected, when
the whole is rented, to yield to the state revenue of about $2,000,000.
George Sand, in the Histoire de ma Vie, speaks of the cork-forests in
Southern France as among the most profitable of rural possessions, and
states, what I do not remember to have seen noticed elsewhere, that Russia
Page 428
is the best customer for cork. The large sheets taken from the trees are slit
into thin plates, and used to line the walls of apartments in that cold climate.
On the cultivation and management of the cork oak, see Des Incendies et de
la culture du Chene-liege, in Revue das Eaux et Forets for February, 1869.]
the walnut, the chestnut, the cork oak, the mulberry, the olive, the orange,
the lemon, the fig, and the multitude of other trees which, by their fruit, or
by other products, yield an annual revenue, nature has provided Southern
Europe with a partial compensation for the loss of the native forest. It is true
that these trees, planted as most of them are at such distances as to admit of
cultivation, or of the growth of grass among them, are but an inadequate
substitute for the thick and shady wood; but they perform to a certain extent
the same offices of absorption and transpiration, they shade the surface of
the ground, they serve to break the force of the wind, and on many a steep
declivity, many a bleak and barren hillside, the chestnut binds the soil
together with its roots, and prevents tons of earth and gravel from washing
down upon the fields and the gardens. Fruit-trees are not wanting, certainly,
north of the Alps. The apple, the pear, and the prune are important in the
economy both of man and of nature, but they are far less numerous in
Switzerland and Northern France than are the trees I have mentioned in
Southern Europe, both because they are in general less remunerative, and
because the climate, in higher latitudes, does not permit the free
introduction of shade trees into grounds occupied for agricultural purposes.
[Footnote: The walnut, the chestnut, the apple, and the pear are common to
the border between the countries I have mentioned, but the range of the
other trees is bounded by the Alps, and by a well-defined and sharply drawn
line to the west of those mountains. From some peculiarity in the sky of
Europe, cultivated plants will thrive, in Northern Italy, in Southern France,
and even in Switzerland, under a depth of shade where no crop, not even
grass, worth harvesting, would grow in the United States with an equally
high summer temperature. Hence the cultivation of all these trees is
into thin plates, and used to line the walls of apartments in that cold climate.
On the cultivation and management of the cork oak, see Des Incendies et de
la culture du Chene-liege, in Revue das Eaux et Forets for February, 1869.]
the walnut, the chestnut, the cork oak, the mulberry, the olive, the orange,
the lemon, the fig, and the multitude of other trees which, by their fruit, or
by other products, yield an annual revenue, nature has provided Southern
Europe with a partial compensation for the loss of the native forest. It is true
that these trees, planted as most of them are at such distances as to admit of
cultivation, or of the growth of grass among them, are but an inadequate
substitute for the thick and shady wood; but they perform to a certain extent
the same offices of absorption and transpiration, they shade the surface of
the ground, they serve to break the force of the wind, and on many a steep
declivity, many a bleak and barren hillside, the chestnut binds the soil
together with its roots, and prevents tons of earth and gravel from washing
down upon the fields and the gardens. Fruit-trees are not wanting, certainly,
north of the Alps. The apple, the pear, and the prune are important in the
economy both of man and of nature, but they are far less numerous in
Switzerland and Northern France than are the trees I have mentioned in
Southern Europe, both because they are in general less remunerative, and
because the climate, in higher latitudes, does not permit the free
introduction of shade trees into grounds occupied for agricultural purposes.
[Footnote: The walnut, the chestnut, the apple, and the pear are common to
the border between the countries I have mentioned, but the range of the
other trees is bounded by the Alps, and by a well-defined and sharply drawn
line to the west of those mountains. From some peculiarity in the sky of
Europe, cultivated plants will thrive, in Northern Italy, in Southern France,
and even in Switzerland, under a depth of shade where no crop, not even
grass, worth harvesting, would grow in the United States with an equally
high summer temperature. Hence the cultivation of all these trees is
Page 429
practicable in Europe to a greater extent than would be supposed
reconcilable with the interests of agriculture. Some idea of the importance
of the olive orchards may be formed from the fact that Sicily alone, an
island scarcely exceeding 10,000 square miles in area, of which one-third at
least is absolutely barren, has exported to the single port of Marseilles more
than 2,000,000 pounds weight olive-oil per year, for the last thirty years.
According to Cosimo Ridolfi, Lezioni Orali, vol. ii., p. 340, in a
favorable soil and climate the average yield of oil from poorly manured
trees, which compose the great majority, is six English pounds, while with
the best cultivation it rises to twenty-three pounds. The annual production
of olive-oil in the whole of Italy is estimated at upwards of 850,000,000
pounds, and if we allow twelve pounds to the tree, we have something more
than 70,000,000 trees. The real number of trees is, however, much greater
than this estimate, for in Tuscany and many other parts of Italy the average
yield of oil per tree does not exceed two pounds, and there are many
millions of young trees not yet in bearing. Probably we shall not exaggerate
if we estimate the olive trees of Italy at 100,000,000, and as there are about
a hundred trees to the acre, the quantity of land devoted to the cultivation of
the olive may be taken at a million acres. Although olive-oil is much used in
cookery in Italy, lard is preferred as more nutritious. Much American lard is
exported to South-eastern Italy, and olive-oil is imported in return.] The
multitude of species, intermixed as they are in their spontaneous growth,
gives the American forest landscape a variety of aspect not often seen in the
woods of Europe, and the gorgeous tints, which nature repeats from the
dying dolphin to paint the falling leaf of the American maples, oaks, and
ash trees, clothe the hillsides and fringe the water-courses with a rainbow
splendor of foliage, unsurpassed by the brightest groupings of the tropical
flora. It must be confessed, however, that both the northern and the southern
declivities of the Alps exhibit a nearer approximation to this rich and
multifarious coloring of autumnal vegetation than most American travellers
reconcilable with the interests of agriculture. Some idea of the importance
of the olive orchards may be formed from the fact that Sicily alone, an
island scarcely exceeding 10,000 square miles in area, of which one-third at
least is absolutely barren, has exported to the single port of Marseilles more
than 2,000,000 pounds weight olive-oil per year, for the last thirty years.
According to Cosimo Ridolfi, Lezioni Orali, vol. ii., p. 340, in a
favorable soil and climate the average yield of oil from poorly manured
trees, which compose the great majority, is six English pounds, while with
the best cultivation it rises to twenty-three pounds. The annual production
of olive-oil in the whole of Italy is estimated at upwards of 850,000,000
pounds, and if we allow twelve pounds to the tree, we have something more
than 70,000,000 trees. The real number of trees is, however, much greater
than this estimate, for in Tuscany and many other parts of Italy the average
yield of oil per tree does not exceed two pounds, and there are many
millions of young trees not yet in bearing. Probably we shall not exaggerate
if we estimate the olive trees of Italy at 100,000,000, and as there are about
a hundred trees to the acre, the quantity of land devoted to the cultivation of
the olive may be taken at a million acres. Although olive-oil is much used in
cookery in Italy, lard is preferred as more nutritious. Much American lard is
exported to South-eastern Italy, and olive-oil is imported in return.] The
multitude of species, intermixed as they are in their spontaneous growth,
gives the American forest landscape a variety of aspect not often seen in the
woods of Europe, and the gorgeous tints, which nature repeats from the
dying dolphin to paint the falling leaf of the American maples, oaks, and
ash trees, clothe the hillsides and fringe the water-courses with a rainbow
splendor of foliage, unsurpassed by the brightest groupings of the tropical
flora. It must be confessed, however, that both the northern and the southern
declivities of the Alps exhibit a nearer approximation to this rich and
multifarious coloring of autumnal vegetation than most American travellers
Page 430
in Europe are willing to allow; and, besides, the small deciduous shrubs
which often carpet the forest-glades of these mountains are dyed with a
ruddy and orange glow, which, in the distant landscape, is no mean
substitute for the scarlet and crimson and gold and amber of the
transatlantic woodland. [Footnote: The most gorgeous autumnal coloring I
have observed in the vegetation of Europe has been in the valleys of the
Durance and its tributaries in Dauphiny. I must admit that neither in variety
nor in purity and brilliancy of tint, does this coloring fall much, if at all,
short of that of the New England woods. But there is this difference: in
Dauphiny, it is only in small shrubs that this rich painting is seen, while in
North America the foliage of large trees is dyed in full splendor. Hence the
American woodland has fewer broken lights and more of what painters call
breadth of coloring. Besides this, the arrangement of the leafage in large
globular or conical masses, affords a wider scale of light and shade, thus
aiding now the gradation now the contrast of tints, and gives the American
October landscape a softer and more harmonious tone than marks the
humble shrubbery of the forest hillsides of Dauphiny.
Thoreau—who was not, like some very celebrated landscape critics of
the present day, an outside spectator of the action and products of natural
forces, but, in the old religious sense, an OBSERVER of organic nature,
living, more than almost any other descriptive writer, among and with her
children—had a very eloquent paper on the "Autumnal Tints" of the New
England landscape.—See his Excursions, pp. 215 et seqq.
Few men have personally noticed so many facts in natural history
accessible to unscientific observation as Thoreau, and yet he had never seen
that very common and striking spectacle, the phosphorescence of decaying
wood, until, in the latter years of his life, it caught his attention in a bivouac
in the forests of Maine. He seems to have been more excited by this
phenomenon than by any other described in his works. It must be a
which often carpet the forest-glades of these mountains are dyed with a
ruddy and orange glow, which, in the distant landscape, is no mean
substitute for the scarlet and crimson and gold and amber of the
transatlantic woodland. [Footnote: The most gorgeous autumnal coloring I
have observed in the vegetation of Europe has been in the valleys of the
Durance and its tributaries in Dauphiny. I must admit that neither in variety
nor in purity and brilliancy of tint, does this coloring fall much, if at all,
short of that of the New England woods. But there is this difference: in
Dauphiny, it is only in small shrubs that this rich painting is seen, while in
North America the foliage of large trees is dyed in full splendor. Hence the
American woodland has fewer broken lights and more of what painters call
breadth of coloring. Besides this, the arrangement of the leafage in large
globular or conical masses, affords a wider scale of light and shade, thus
aiding now the gradation now the contrast of tints, and gives the American
October landscape a softer and more harmonious tone than marks the
humble shrubbery of the forest hillsides of Dauphiny.
Thoreau—who was not, like some very celebrated landscape critics of
the present day, an outside spectator of the action and products of natural
forces, but, in the old religious sense, an OBSERVER of organic nature,
living, more than almost any other descriptive writer, among and with her
children—had a very eloquent paper on the "Autumnal Tints" of the New
England landscape.—See his Excursions, pp. 215 et seqq.
Few men have personally noticed so many facts in natural history
accessible to unscientific observation as Thoreau, and yet he had never seen
that very common and striking spectacle, the phosphorescence of decaying
wood, until, in the latter years of his life, it caught his attention in a bivouac
in the forests of Maine. He seems to have been more excited by this
phenomenon than by any other described in his works. It must be a
Page 431
capacious eye that takes in all the visible facts in the history of the most
familiar natural object.—The Maine Woods, p. 184.]
I admit, though not without reluctance, that the forest-trees of Central and
Southern Europe have a great advantage over our own in the corresponding
latitudes, in density of foliage as well as in depth of color and persistence of
the leaves in deciduous species. An American, who, after a long absence
from the United States, returns in the full height of summer, is painfully
surprised at the thinness and poverty of the leafage even of the trees which
he had habitually regarded as specially umbrageous, and he must wait for
the autumnal frosts before he can recover his partiality for the glories of his
native woods.
None of our north-eastern evergreens resemble the umbrella pine
sufficiently to be a fair object of comparison with it. A cedar, very common
above the Highlands on the Hudson, and elsewhere, is extremely like the
cypress, straight, slender, with erect, compressed ramification, and
feathered to the ground, but its foliage is neither so dark nor so dense, the
tree does not attain the majestic height of the cypress, nor has it the lithe
flexibility of that tree. [Footnote: The cold winter, or rather spring, of 1872
proved fatal to many cypresses as well as olive trees in the Val d'Arno. The
cypress, therefore, could be introduced only into California and our
Southern States.] In mere shape, the Lombardy poplar nearly resembles this
latter, but it is almost a profanation to compare the two, especially when
they are agitated by the wind; for under such circumstances, the one is the
most majestic, the other the most ungraceful, or—if I may apply such an
expression to anything but human affectation of movement—the most
awkward of trees. The poplar trembles before the blast, flutters, struggles
wildly, dishevels its foliage, gropes around with its feeble branches, and
hisses as in impotent passion. The cypress gathers its limbs still more
closely to its stem, bows a gracious salute rather than an humble obeisance
familiar natural object.—The Maine Woods, p. 184.]
I admit, though not without reluctance, that the forest-trees of Central and
Southern Europe have a great advantage over our own in the corresponding
latitudes, in density of foliage as well as in depth of color and persistence of
the leaves in deciduous species. An American, who, after a long absence
from the United States, returns in the full height of summer, is painfully
surprised at the thinness and poverty of the leafage even of the trees which
he had habitually regarded as specially umbrageous, and he must wait for
the autumnal frosts before he can recover his partiality for the glories of his
native woods.
None of our north-eastern evergreens resemble the umbrella pine
sufficiently to be a fair object of comparison with it. A cedar, very common
above the Highlands on the Hudson, and elsewhere, is extremely like the
cypress, straight, slender, with erect, compressed ramification, and
feathered to the ground, but its foliage is neither so dark nor so dense, the
tree does not attain the majestic height of the cypress, nor has it the lithe
flexibility of that tree. [Footnote: The cold winter, or rather spring, of 1872
proved fatal to many cypresses as well as olive trees in the Val d'Arno. The
cypress, therefore, could be introduced only into California and our
Southern States.] In mere shape, the Lombardy poplar nearly resembles this
latter, but it is almost a profanation to compare the two, especially when
they are agitated by the wind; for under such circumstances, the one is the
most majestic, the other the most ungraceful, or—if I may apply such an
expression to anything but human affectation of movement—the most
awkward of trees. The poplar trembles before the blast, flutters, struggles
wildly, dishevels its foliage, gropes around with its feeble branches, and
hisses as in impotent passion. The cypress gathers its limbs still more
closely to its stem, bows a gracious salute rather than an humble obeisance
Page 432
to the tempest, bends to the wind with an elasticity that assures you of its
prompt return to its regal attitude, and sends from its thick leaflets a
murmur like the roar of the far-off ocean.
The cypress and the umbrella-pine are not merely conventional types of
the Italian landscape. They are essential elements in a field of rural beauty
which can be seen in perfection only in the basin of the Mediterranean, and
they are as characteristic of this class of scenery as is the date-palm of the
oases of the Eastern desert. There is however, this difference: a single
cypress or pine is often enough to shed beauty over a wide area; the palm is
a social tree, and its beauty is not so much that of the individual as of the
group. [Footnote: European poets, whose knowledge of the date-palm is not
founded on personal observation, often describe its trunk as not only
slender, but particularly STRAIGHT. Nothing can be farther from the truth.
When the Orientals compare the form of a beautiful girl to the stem of the
palm, they do not represent it as rigidly straight, but on the contrary as
made up of graceful curves, which seem less like permanent outlines than
like flowing motion. In a palm grove, the trunks, so far from standing
planted upright like the candles of a chandelier, bend in a vast variety of
curves, now leaning towards, now diverging from, now crossing, each
other, and among a hundred you will hardly see two whose axes are
parallel.] The frequency of the cypress and the pine—combined with the
fact that the other trees of Southern Europe which most interest a stranger
from the north, the orange and the lemon, the cork oak, the ilex, the myrtle,
and the laurel, are evergreens—goes far to explain the beauty of the winter
scenery of Italy. Indeed, it is only in the winter that a tourist who confines
himself to wheel-carriages and high roads can acquire any notion of the
face of the earth, and form any proper geographical image of that country.
At other seasons, not high walls only, but equally impervious hedges, and
now, unhappily, acacias thickly planted along the railway routes, confine
the view so completely, that the arch of a tunnel, or a night-cap over the
prompt return to its regal attitude, and sends from its thick leaflets a
murmur like the roar of the far-off ocean.
The cypress and the umbrella-pine are not merely conventional types of
the Italian landscape. They are essential elements in a field of rural beauty
which can be seen in perfection only in the basin of the Mediterranean, and
they are as characteristic of this class of scenery as is the date-palm of the
oases of the Eastern desert. There is however, this difference: a single
cypress or pine is often enough to shed beauty over a wide area; the palm is
a social tree, and its beauty is not so much that of the individual as of the
group. [Footnote: European poets, whose knowledge of the date-palm is not
founded on personal observation, often describe its trunk as not only
slender, but particularly STRAIGHT. Nothing can be farther from the truth.
When the Orientals compare the form of a beautiful girl to the stem of the
palm, they do not represent it as rigidly straight, but on the contrary as
made up of graceful curves, which seem less like permanent outlines than
like flowing motion. In a palm grove, the trunks, so far from standing
planted upright like the candles of a chandelier, bend in a vast variety of
curves, now leaning towards, now diverging from, now crossing, each
other, and among a hundred you will hardly see two whose axes are
parallel.] The frequency of the cypress and the pine—combined with the
fact that the other trees of Southern Europe which most interest a stranger
from the north, the orange and the lemon, the cork oak, the ilex, the myrtle,
and the laurel, are evergreens—goes far to explain the beauty of the winter
scenery of Italy. Indeed, it is only in the winter that a tourist who confines
himself to wheel-carriages and high roads can acquire any notion of the
face of the earth, and form any proper geographical image of that country.
At other seasons, not high walls only, but equally impervious hedges, and
now, unhappily, acacias thickly planted along the railway routes, confine
the view so completely, that the arch of a tunnel, or a night-cap over the
Page 433
traveller's eyes, is scarcely a more effectual obstacle to the gratification of
his curiosity. [Footnote: Besides this, in a country so diversified in surface
as Italy, with the exception of the champaign region drained by the Po,
every new field of view requires either an extraordinary coup d'oeil in the
spectator, or a long study, in order to master its relief, its plans, its salient
and retreating angles. In summer, except of course in the bare mountains,
the universal greenery confounds light and shade, distance and foreground;
and though the impression upon a traveller, who journeys for the sake of
"sensations," may be strengthened by the mysterious annihilation of all
standards for the measurement of space, yet the superior intelligibility of
the winter scenery of Italy is more profitable to those who see with a view
to analyze.]
The Forest does not furnish Food for Man.
In a region absolutely covered with trees, human life could not long be
sustained, for want of animal and vegetable food. The depths of the forest
seldom furnish either bulb or fruit suited to the nourishment of man; and the
fowls and beasts on which he feeds are scarcely seen except upon the
margin of the wood, for here only grow the shrubs and grasses, and here
only are found the seeds and insects, which form the sustenance of the non-
carnivorous birds and quadrupeds. [Footnote: Clave, as well as many earlier
writers, supposes that primitive man derived his nutriment from the
spontaneous productions of the wood. "It is to the forests," says he, "that
man was first indebted for the means of subsistence. Exposed alone,
without defence, to the rigor of the seasons, as well as to the attacks of
animals stronger and swifter than himself, he found in them his first shelter,
drew from them his first weapons. In the first period of humanity, they
provided for all his wants: they furnished him wood for warmth, fruits for
his curiosity. [Footnote: Besides this, in a country so diversified in surface
as Italy, with the exception of the champaign region drained by the Po,
every new field of view requires either an extraordinary coup d'oeil in the
spectator, or a long study, in order to master its relief, its plans, its salient
and retreating angles. In summer, except of course in the bare mountains,
the universal greenery confounds light and shade, distance and foreground;
and though the impression upon a traveller, who journeys for the sake of
"sensations," may be strengthened by the mysterious annihilation of all
standards for the measurement of space, yet the superior intelligibility of
the winter scenery of Italy is more profitable to those who see with a view
to analyze.]
The Forest does not furnish Food for Man.
In a region absolutely covered with trees, human life could not long be
sustained, for want of animal and vegetable food. The depths of the forest
seldom furnish either bulb or fruit suited to the nourishment of man; and the
fowls and beasts on which he feeds are scarcely seen except upon the
margin of the wood, for here only grow the shrubs and grasses, and here
only are found the seeds and insects, which form the sustenance of the non-
carnivorous birds and quadrupeds. [Footnote: Clave, as well as many earlier
writers, supposes that primitive man derived his nutriment from the
spontaneous productions of the wood. "It is to the forests," says he, "that
man was first indebted for the means of subsistence. Exposed alone,
without defence, to the rigor of the seasons, as well as to the attacks of
animals stronger and swifter than himself, he found in them his first shelter,
drew from them his first weapons. In the first period of humanity, they
provided for all his wants: they furnished him wood for warmth, fruits for
Page 434
food, garments to cover his nakedness, arms for his defence."—Etudes sur
l'Economie Forestiere, p. 13.
But the history of savage life, as far as it is known to us, presents man in
that condition as inhabiting only the borders of the forest and the open
grounds that skirt the waters and the woods, and as finding only there the
aliments which make up his daily bread. The villages of the North
American Indians were upon the shores of rivers and lakes, and their
weapons and other relics are found only in the narrow open grounds which
they had burned over and cultivated, or in the margin of the woods around
their hamlets.
Except upon the banks of rivers or of lakes, the woods of the interior of
North America, far from the habitations of man, are almost destitute of
animal life. Dr. Newberry, describing the vast forests of the yellow pine of
the West, Pinus ponderosa, remarks: "In the arid and desert regions of the
interior basin, we made whole days' marches in forests of yellow pine, of
which neither the monotony was broken by other forms of vegetation, nor
its stillness by the flutter of a bird or the hum of an insect."—Pacific
Railroad Report, vol. vi., 1857. Dr. Newberry's Report on Botany, p. 37.
Cheadle and Milton's North-west Passage confirms these statements.
Valvasor says, in a paragraph already quoted, "In my many journeys
through this valley, I did never have sight of so much as a single bird."
The wild fruit and nut trees, the Canada plum, the cherries, the many
species of walnut, the butternut, the hazel, yield very little, frequently
nothing, so long as they grow in the woods; and it is only when the trees
around them are cut down, or when they grow in pastures, that they become
productive. The berries, too—the strawberry, the blackberry, the raspberry,
the whortleberry, scarcely bear fruit at all except in cleared ground.
l'Economie Forestiere, p. 13.
But the history of savage life, as far as it is known to us, presents man in
that condition as inhabiting only the borders of the forest and the open
grounds that skirt the waters and the woods, and as finding only there the
aliments which make up his daily bread. The villages of the North
American Indians were upon the shores of rivers and lakes, and their
weapons and other relics are found only in the narrow open grounds which
they had burned over and cultivated, or in the margin of the woods around
their hamlets.
Except upon the banks of rivers or of lakes, the woods of the interior of
North America, far from the habitations of man, are almost destitute of
animal life. Dr. Newberry, describing the vast forests of the yellow pine of
the West, Pinus ponderosa, remarks: "In the arid and desert regions of the
interior basin, we made whole days' marches in forests of yellow pine, of
which neither the monotony was broken by other forms of vegetation, nor
its stillness by the flutter of a bird or the hum of an insect."—Pacific
Railroad Report, vol. vi., 1857. Dr. Newberry's Report on Botany, p. 37.
Cheadle and Milton's North-west Passage confirms these statements.
Valvasor says, in a paragraph already quoted, "In my many journeys
through this valley, I did never have sight of so much as a single bird."
The wild fruit and nut trees, the Canada plum, the cherries, the many
species of walnut, the butternut, the hazel, yield very little, frequently
nothing, so long as they grow in the woods; and it is only when the trees
around them are cut down, or when they grow in pastures, that they become
productive. The berries, too—the strawberry, the blackberry, the raspberry,
the whortleberry, scarcely bear fruit at all except in cleared ground.
Page 435
The rank forests of the tropics are as unproductive of human aliment as
the less luxuriant woods of the temperate zone. In Strain's unfortunate
expedition across the great American isthmus, where the journey lay
principally through thick woods, several of the party died of starvation, and
for many days the survivors were forced to subsist on the scantiest supplies
of unnutritious vegetables perhaps never before employed for food by man.
See the interesting account of that expedition in Harper's Magazine for
March, April, and May, 1855.]
First Removal of the Forest.
When multiplying man had filled the open grounds along the margin of
the rivers, the lakes, and the sea, and sufficiently peopled the natural
meadows and savannas of the interior, where such existed, he could find
room for expansion and further growth only by the removal of a portion of
the forest that hemmed him in. The destruction of the woods, then, was
man's first geographical conquest, his first violation of the harmonies of
inanimate nature.
Primitive man had little occasion to fell trees for fuel, or for the
construction of dwellings, boats, and the implements of his rude agriculture
and handicrafts. Windfalls would furnish a thin population with a sufficient
supply of such material, and if occasionally a growing tree was cut, the
injury to the forest would be too insignificant to be at all appreciable.
The accidental escape and spread of fire or possibly, the combustion of
forests by lightning, must have first suggested the advantages to be derived
from the removal of too abundant and extensive woods, and at the same
time, have pointed out a means by which a large tract of surface could
readily be cleared of much of this natural incumbrance. As soon as
agriculture had commenced at all, it would be observed that the growth of
the less luxuriant woods of the temperate zone. In Strain's unfortunate
expedition across the great American isthmus, where the journey lay
principally through thick woods, several of the party died of starvation, and
for many days the survivors were forced to subsist on the scantiest supplies
of unnutritious vegetables perhaps never before employed for food by man.
See the interesting account of that expedition in Harper's Magazine for
March, April, and May, 1855.]
First Removal of the Forest.
When multiplying man had filled the open grounds along the margin of
the rivers, the lakes, and the sea, and sufficiently peopled the natural
meadows and savannas of the interior, where such existed, he could find
room for expansion and further growth only by the removal of a portion of
the forest that hemmed him in. The destruction of the woods, then, was
man's first geographical conquest, his first violation of the harmonies of
inanimate nature.
Primitive man had little occasion to fell trees for fuel, or for the
construction of dwellings, boats, and the implements of his rude agriculture
and handicrafts. Windfalls would furnish a thin population with a sufficient
supply of such material, and if occasionally a growing tree was cut, the
injury to the forest would be too insignificant to be at all appreciable.
The accidental escape and spread of fire or possibly, the combustion of
forests by lightning, must have first suggested the advantages to be derived
from the removal of too abundant and extensive woods, and at the same
time, have pointed out a means by which a large tract of surface could
readily be cleared of much of this natural incumbrance. As soon as
agriculture had commenced at all, it would be observed that the growth of
Page 436
cultivated plants, as well as of many species of wild vegetation, was
particularly rapid and luxuriant on soils which had been burned over, and
thus a new stimulus would be given to the practice of destroying the woods
by fire, as a means of both extending the open grounds, and making the
acquisition of a yet more productive soil. After a few harvests had
exhausted the first rank fertility of this virgin mould, or when weeds and
briers and the sprouting roots of the trees had begun to choke the crops of
the half-subdued soil, the ground would be abandoned for new fields won
from the forest by the same means, and the deserted plain or hillock would
soon clothe itself anew with shrubs and trees, to be again subjected to the
same destructive process, and again surrendered to the restorative powers of
vegetable nature. [Footnote: In many parts of the North American States,
the first white settlers found extensive tracts of thin woods, of a very park-
like character, called "oak-openings," from the predominance of different
species of that tree upon them. These were the semi-artificial pasture-
grounds of the Indians, brought into that state, and so kept, by partial
clearing, and by the annual burning of the grass. The object of this
operation was to attract the deer to the fresh herbage which sprang up after
the fire. The oaks bore the annual scorching at least for a certain time; but if
it had been indefinitely continued, they would very probably have been
destroyed at last. The soil would have then been much in the prairie
condition, and would have needed nothing but grazing for a long succession
of years to make the resemblance perfect. That the annual fires alone
occasioned the peculiar character of the oak-openings, is proved by the fact
that as soon as the Indians had left the country, young trees of many species
sprang up and grew luxuriantly upon them. See a very interesting account
of the oak-openings in Dwight s Travels, iv., pp. 58-63. This rude economy
would be continued for generations, and, wasteful as it is, is still largely
pursued in Northern Sweden, Swedish Lapland, and sometimes even in
France and the United States. [Footnote: The practice of burning over
particularly rapid and luxuriant on soils which had been burned over, and
thus a new stimulus would be given to the practice of destroying the woods
by fire, as a means of both extending the open grounds, and making the
acquisition of a yet more productive soil. After a few harvests had
exhausted the first rank fertility of this virgin mould, or when weeds and
briers and the sprouting roots of the trees had begun to choke the crops of
the half-subdued soil, the ground would be abandoned for new fields won
from the forest by the same means, and the deserted plain or hillock would
soon clothe itself anew with shrubs and trees, to be again subjected to the
same destructive process, and again surrendered to the restorative powers of
vegetable nature. [Footnote: In many parts of the North American States,
the first white settlers found extensive tracts of thin woods, of a very park-
like character, called "oak-openings," from the predominance of different
species of that tree upon them. These were the semi-artificial pasture-
grounds of the Indians, brought into that state, and so kept, by partial
clearing, and by the annual burning of the grass. The object of this
operation was to attract the deer to the fresh herbage which sprang up after
the fire. The oaks bore the annual scorching at least for a certain time; but if
it had been indefinitely continued, they would very probably have been
destroyed at last. The soil would have then been much in the prairie
condition, and would have needed nothing but grazing for a long succession
of years to make the resemblance perfect. That the annual fires alone
occasioned the peculiar character of the oak-openings, is proved by the fact
that as soon as the Indians had left the country, young trees of many species
sprang up and grew luxuriantly upon them. See a very interesting account
of the oak-openings in Dwight s Travels, iv., pp. 58-63. This rude economy
would be continued for generations, and, wasteful as it is, is still largely
pursued in Northern Sweden, Swedish Lapland, and sometimes even in
France and the United States. [Footnote: The practice of burning over
Page 437
woodland, at once to clear and manure the ground, is called in Swedieh
svedjande, a participial noun from the verb att svedja, to burn over. Though
used in Sweden as a preparation for crops of rye or other grain, it is
employed in Lapland more frequently to secure an abundant growth of
pasturage, which follows in two or three years after the fire; and it is
sometimes resorted to as a mode of driving the Laplanders and their
reindeer from the vicinity of the Swedish backwoodsman's grass-grounds
and hay-stacks, to which they are dangerous neighbors. The forest, indeed,
rapidly recovers itself, but it is a generation or more before the reindeer-
moss grows again. When the forest consists of pine, tall, the ground, instead
of being rendered fertile by this process, becomes hopelessly barren, and for
a long time afterwards produces nothing but weeds and briers.—Laestadius,
Om Uppodlingar i Lappmarken, p. 15. See also Schubert, Resa i Sverge, ii.,
p. 375.
In some parts of France this practice is so general that Clave says: "In the
department of Ardennes it (le sartage) is the basis of agriculture."]
Principal Causes of the Destruction of the Forest.
The needs of agriculture are the most familiar cause of the destruction of
the forest in new countries; for not only does an increasing population
demand additional acres to grow the vegetables which feed it and its
domestic animals, but the slovenly husbandry of the border settler soon
exhausts the luxuriance of his first fields, and compels him to remove his
household gods to a fresher soil. The extent of cleared ground required for
agricultural use depends very much on the number and kinds of the cattle
bred. We have seen, in a former chapter, that, in the United States, the
domestic quadrupeds amount to more than a hundred millions, or nearly
three times the number of the human population of the Union. In many of
the Western States, the swine subsist more or less on acorns, nuts, and other
svedjande, a participial noun from the verb att svedja, to burn over. Though
used in Sweden as a preparation for crops of rye or other grain, it is
employed in Lapland more frequently to secure an abundant growth of
pasturage, which follows in two or three years after the fire; and it is
sometimes resorted to as a mode of driving the Laplanders and their
reindeer from the vicinity of the Swedish backwoodsman's grass-grounds
and hay-stacks, to which they are dangerous neighbors. The forest, indeed,
rapidly recovers itself, but it is a generation or more before the reindeer-
moss grows again. When the forest consists of pine, tall, the ground, instead
of being rendered fertile by this process, becomes hopelessly barren, and for
a long time afterwards produces nothing but weeds and briers.—Laestadius,
Om Uppodlingar i Lappmarken, p. 15. See also Schubert, Resa i Sverge, ii.,
p. 375.
In some parts of France this practice is so general that Clave says: "In the
department of Ardennes it (le sartage) is the basis of agriculture."]
Principal Causes of the Destruction of the Forest.
The needs of agriculture are the most familiar cause of the destruction of
the forest in new countries; for not only does an increasing population
demand additional acres to grow the vegetables which feed it and its
domestic animals, but the slovenly husbandry of the border settler soon
exhausts the luxuriance of his first fields, and compels him to remove his
household gods to a fresher soil. The extent of cleared ground required for
agricultural use depends very much on the number and kinds of the cattle
bred. We have seen, in a former chapter, that, in the United States, the
domestic quadrupeds amount to more than a hundred millions, or nearly
three times the number of the human population of the Union. In many of
the Western States, the swine subsist more or less on acorns, nuts, and other
Page 438
products of the woods, and the prairies, or natural meadows of the
Mississippi valley, yield a large amount of food for beast, as well as for
man. With these exceptions, all this vast army of quadrupeds is fed wholly
on grass, grain, pulse, and roots grown on soil reclaimed from the forest by
European settlers. It is true that the flesh of domestic quadrupeds enters
very largely into the aliment of the American people, and greatly reduces
the quantity of vegetable nutriment which they would otherwise consume,
so that a smaller amount of agricultural product is required for immediate
human food, and, of course, a smaller extent of cleared land is needed for
the growth of that product, than if no domestic animals existed. But the
flesh of the horse, the ass, and the mule is not consumed by man, and the
sheep is reared rather for its fleece than for food. Besides this, the ground
required to produce the grass and grain consumed in rearing and fattening a
grazing quadruped, would yield a far larger amount of nutriment, if devoted
to the growing of breadstuffs, than is furnished by his flesh; and, upon the
whole, whatever advantages may be reaped from the breeding of domestic
cattle, it is plain that the cleared land devoted to their sustenance in the
originally wooded part of the United States, after deducting a quantity
sufficient to produce an amount of aliment equal to their flesh, still greatly
exceeds that cultivated for vegetables, directly consumed by the people of
the same regions; or, to express a nearly equivalent idea in other words, the
meadow and the pasture, taken together, much exceed the ploughland.
[Footnote: The two ideas expressed in the text are not exactly equivalent,
because, though the consumption of animal food diminishes the amount of
vegetable aliment required for human use, yet the animals themselves
consume a great quantity of grain and roots grown on ground ploughed and
cultivated as regularly and as laboriously as any other.
The 280,000,000 bushels of oats raised in the United States in 1870, and
fed to the 7,000,000 horses, the potatoes, the turnips, and the maize
employed in fattening the oxen, the sheep, and the swine slaughtered the
Mississippi valley, yield a large amount of food for beast, as well as for
man. With these exceptions, all this vast army of quadrupeds is fed wholly
on grass, grain, pulse, and roots grown on soil reclaimed from the forest by
European settlers. It is true that the flesh of domestic quadrupeds enters
very largely into the aliment of the American people, and greatly reduces
the quantity of vegetable nutriment which they would otherwise consume,
so that a smaller amount of agricultural product is required for immediate
human food, and, of course, a smaller extent of cleared land is needed for
the growth of that product, than if no domestic animals existed. But the
flesh of the horse, the ass, and the mule is not consumed by man, and the
sheep is reared rather for its fleece than for food. Besides this, the ground
required to produce the grass and grain consumed in rearing and fattening a
grazing quadruped, would yield a far larger amount of nutriment, if devoted
to the growing of breadstuffs, than is furnished by his flesh; and, upon the
whole, whatever advantages may be reaped from the breeding of domestic
cattle, it is plain that the cleared land devoted to their sustenance in the
originally wooded part of the United States, after deducting a quantity
sufficient to produce an amount of aliment equal to their flesh, still greatly
exceeds that cultivated for vegetables, directly consumed by the people of
the same regions; or, to express a nearly equivalent idea in other words, the
meadow and the pasture, taken together, much exceed the ploughland.
[Footnote: The two ideas expressed in the text are not exactly equivalent,
because, though the consumption of animal food diminishes the amount of
vegetable aliment required for human use, yet the animals themselves
consume a great quantity of grain and roots grown on ground ploughed and
cultivated as regularly and as laboriously as any other.
The 280,000,000 bushels of oats raised in the United States in 1870, and
fed to the 7,000,000 horses, the potatoes, the turnips, and the maize
employed in fattening the oxen, the sheep, and the swine slaughtered the
Page 439
same year, occupied an extent of ground which, cultivated by hand-labor
and with Chinese industry and skill, would probably have produced a
quantity of vegetable food equal in alimentary power to the flesh of the
quadrupeds killed for domestic use. Hence, so far as the naked question of
AMOUNT of aliment is concerned, the meadows and the pastures might as
well have remained in the forest condition. It must, however, be borne in
mind that animal labor, if not a necessary, is probably an economical, force
in agricultural occupations, and that without animal manure many branches
of husbandry could hardly be carried on at all. At the same time, the
introduction of machinery into rural industry, and of artificial, mineral, and
fossil manures, is working great revolutions, and we may find at some
future day that the ox is no longer necessary as a help to the farmer.]
Governments and military commanders have at different periods
deliberately destroyed forests by fire or the axe, because they afforded a
retreat to robbers, outlaws, or enemies, and this was one of the hostile
measures practised by both Julius Caesar and the Gauls in the Roman war
of conquest against that people. It was also resorted to in the Mediterranean
provinces of France, then much infested by robbers and deserters, as late as
the reign of Napoleon I., and is said to have been employed by the early
American colonists in their exterminating wars with the native Indians.
[Footnote: For many instances of this sort, see Maury, Les Forets de la
Gaule, pp. 3-5, and Becquerel, Des Climats, etc., pp. 301-303. In 1664 the
Swedes made an incursion into Jutland and felled a considerable extent of
forest. After they retired, a survey of the damage was had, and the report is
still extant. The number of trees cut was found to be 120,000, and as an
account was taken of the numbers of each species of tree, the document is
of much interest in the history of the forest, as showing the relative
proportions between the different trees which at that time composed the
wood. See Vaupell, Bogens Indvandring, p. 35, and Notes, p. 55.]
and with Chinese industry and skill, would probably have produced a
quantity of vegetable food equal in alimentary power to the flesh of the
quadrupeds killed for domestic use. Hence, so far as the naked question of
AMOUNT of aliment is concerned, the meadows and the pastures might as
well have remained in the forest condition. It must, however, be borne in
mind that animal labor, if not a necessary, is probably an economical, force
in agricultural occupations, and that without animal manure many branches
of husbandry could hardly be carried on at all. At the same time, the
introduction of machinery into rural industry, and of artificial, mineral, and
fossil manures, is working great revolutions, and we may find at some
future day that the ox is no longer necessary as a help to the farmer.]
Governments and military commanders have at different periods
deliberately destroyed forests by fire or the axe, because they afforded a
retreat to robbers, outlaws, or enemies, and this was one of the hostile
measures practised by both Julius Caesar and the Gauls in the Roman war
of conquest against that people. It was also resorted to in the Mediterranean
provinces of France, then much infested by robbers and deserters, as late as
the reign of Napoleon I., and is said to have been employed by the early
American colonists in their exterminating wars with the native Indians.
[Footnote: For many instances of this sort, see Maury, Les Forets de la
Gaule, pp. 3-5, and Becquerel, Des Climats, etc., pp. 301-303. In 1664 the
Swedes made an incursion into Jutland and felled a considerable extent of
forest. After they retired, a survey of the damage was had, and the report is
still extant. The number of trees cut was found to be 120,000, and as an
account was taken of the numbers of each species of tree, the document is
of much interest in the history of the forest, as showing the relative
proportions between the different trees which at that time composed the
wood. See Vaupell, Bogens Indvandring, p. 35, and Notes, p. 55.]
Page 440
In the Middle Ages, as well as in earlier and later centuries, attempts have
been made to protect the woods by law, [Footnote: Stanley, quoting Selden,
De Jure Naturali, lib. vi., and Fabricius, Cod. Psedap., V. T., i. 874,
mentions a noteworthy Hebrew tradition of uncertain date, but
unquestionably very ancient, which is one of the oldest proofs of a public
respect for the woods.
"A Hebrew tradition attributes to Joshua ten statutes, containing precise
regulations for the protection of the property of every tribe and of every
head of a family against irregular depredations. Small quadrupeds were
allowed to pasture in dense woods, not in thin ones; but no animal could
feed in any forest without the consent of the proprietor of the soil. Every
Hebrew might pick up fallen boughs and twigs, but was not permitted to cut
them. Trees might be pruned for the trimmings, with the exception of the
olive and other fruit-trees, and provided there was sufficient shade in the
place."—Lectures on the History of the Jewish Church, part i., p. 271.
Alfred Maury mentions several provisions taken from the laws of the
Indian legislator Manu, on the same subject.—Les Forets de la Gaule, p. 9.
The very ancient Tables of Heracles contain provisions for the protection
of woods, but whether these referred only to sacred groves, to public
forests, or to leased lands, is not clear.] as necessary for the breeding of
deer, wild boars, and other game, or for the more reasonable purpose of
furnishing a supply of building timber and fuel for future generations. It
was reserved for more advanced ages to appreciate the geographical
importance of the woods, and it is only in the most recent times, only in a
few countries of Europe, that the general destruction of the forests has been
recognized as the most potent among the many causes of the physical
deterioration of the earth. [Footnote: We must perhaps make an exception in
favor of the Emperor Constantine, who commenced the magnificent series
been made to protect the woods by law, [Footnote: Stanley, quoting Selden,
De Jure Naturali, lib. vi., and Fabricius, Cod. Psedap., V. T., i. 874,
mentions a noteworthy Hebrew tradition of uncertain date, but
unquestionably very ancient, which is one of the oldest proofs of a public
respect for the woods.
"A Hebrew tradition attributes to Joshua ten statutes, containing precise
regulations for the protection of the property of every tribe and of every
head of a family against irregular depredations. Small quadrupeds were
allowed to pasture in dense woods, not in thin ones; but no animal could
feed in any forest without the consent of the proprietor of the soil. Every
Hebrew might pick up fallen boughs and twigs, but was not permitted to cut
them. Trees might be pruned for the trimmings, with the exception of the
olive and other fruit-trees, and provided there was sufficient shade in the
place."—Lectures on the History of the Jewish Church, part i., p. 271.
Alfred Maury mentions several provisions taken from the laws of the
Indian legislator Manu, on the same subject.—Les Forets de la Gaule, p. 9.
The very ancient Tables of Heracles contain provisions for the protection
of woods, but whether these referred only to sacred groves, to public
forests, or to leased lands, is not clear.] as necessary for the breeding of
deer, wild boars, and other game, or for the more reasonable purpose of
furnishing a supply of building timber and fuel for future generations. It
was reserved for more advanced ages to appreciate the geographical
importance of the woods, and it is only in the most recent times, only in a
few countries of Europe, that the general destruction of the forests has been
recognized as the most potent among the many causes of the physical
deterioration of the earth. [Footnote: We must perhaps make an exception in
favor of the Emperor Constantine, who commenced the magnificent series
Page 441
of aqueducts and cisterns which still supply Constantinople with water, and
enacted strict laws for the protection of the forest of Belgrade, in which rise
the springs that feed the aqueducts. See an article by Mr. H. A. Homes on
the Water-Supply of Constantinople in the Albany Argus of June 6, 1872.]
Royal Forests and Game Laws.
The French authors I have quoted, as well as many other writers of the
same nation, refer to the French Revolution as having given a new impulse
to destructive causes which were already threatening the total extermination
of the woods. [Footnote: Religious intolerance had produced similar effects
in France at an earlier period. "The revocation of the edict of Nantes and the
dragonnades occasioned the sale of the forests of the unhappy Protestants,
who fled to seek in foreign lands the liberty of conscience which was
refused to them in France. The forests were soon felled by the purchasers,
and the soil in part brought under cultivation."—Becquerel, Des Climats,
etc, p. 303.] The general crusade against the forests, which accompanied
that important event, is to be ascribed, in a considerable degree, to political
resentments. The forest codes of the mediaeval kings, and the local
"coutumes" of feudalism, contained many severe and even inhuman
provisions, adopted rather for the preservation of game than from any
enlightened views of the more important functions of the woods. Ordericus
Vitalis informs us that William the Conqueror destroyed sixty parishes and
drove out their inhabitants, in order that he might turn their lands into a
forest, [Footnote: The American reader must be reminded that, in the
language of the chase and of the English law, a "forest" is not necessarily a
wood. Any large extent of ground, withdrawn from cultivation, reserved for
the pleasures of the chase, and allowed to clothe itself with a spontaneous
growth, serving as what is technically called "cover" for wild animals, is, in
the dialects I have mentioned, a forest. When, therefore, the Norman kings
enacted strict laws for the protection of the forest of Belgrade, in which rise
the springs that feed the aqueducts. See an article by Mr. H. A. Homes on
the Water-Supply of Constantinople in the Albany Argus of June 6, 1872.]
Royal Forests and Game Laws.
The French authors I have quoted, as well as many other writers of the
same nation, refer to the French Revolution as having given a new impulse
to destructive causes which were already threatening the total extermination
of the woods. [Footnote: Religious intolerance had produced similar effects
in France at an earlier period. "The revocation of the edict of Nantes and the
dragonnades occasioned the sale of the forests of the unhappy Protestants,
who fled to seek in foreign lands the liberty of conscience which was
refused to them in France. The forests were soon felled by the purchasers,
and the soil in part brought under cultivation."—Becquerel, Des Climats,
etc, p. 303.] The general crusade against the forests, which accompanied
that important event, is to be ascribed, in a considerable degree, to political
resentments. The forest codes of the mediaeval kings, and the local
"coutumes" of feudalism, contained many severe and even inhuman
provisions, adopted rather for the preservation of game than from any
enlightened views of the more important functions of the woods. Ordericus
Vitalis informs us that William the Conqueror destroyed sixty parishes and
drove out their inhabitants, in order that he might turn their lands into a
forest, [Footnote: The American reader must be reminded that, in the
language of the chase and of the English law, a "forest" is not necessarily a
wood. Any large extent of ground, withdrawn from cultivation, reserved for
the pleasures of the chase, and allowed to clothe itself with a spontaneous
growth, serving as what is technically called "cover" for wild animals, is, in
the dialects I have mentioned, a forest. When, therefore, the Norman kings
Page 442
afforested the grounds referred to in the text, it is not to be supposed that
they planted them with trees, though the protection afforded to them by the
game laws would, if cattle had been kept out, soon have converted them
into real woods.] to be reserved as a hunting-ground for himself and his
posterity, and he punished with death the killing of a deer, wild boar, or
even a hare. His successor, William Rufus, according to the Histoire des
Ducs de Normandie et des Rois d'Angleterre, p. 67, "was hunting one day in
a new forest, which he had caused to be made out of eighteen parishes that
he had destroyed, when, by mischance, he was killed by an arrow
wherewith Tyreus de Rois [Sir Walter Tyrell] thought to slay a beast, but
missed the beast, and slew the king, who was beyond it. And in this very
same forest, his brother Richard ran so hard against a tree that he died of it.
And men commonly said that these things were because they had so laid
waste and taken the said parishes."
These barbarous acts, as Bonnemere observes, [Footnote: Histoire des
Paysans, ii., p. 190. The work of Bonnemere is of great value to those who
study the history of mediaeval Europe from a desire to know its real
character, and not in the hope of finding apparent facts to sustain a false and
dangerous theory. Bonnemere is one of the few writers who, like Michelet,
have been honest enough and bold enough to speak the truth with regard to
the relations between the church and the people in the Middle Ages.] were
simply the transfer of the customs of the French kings, of their vassals, and
even of inferior gentlemen, to conquered England. "The death of a hare,"
says our author, "was a hanging matter, the murder of a plover a capital
crime. Death was inflicted on those who spread nets for pigeons; wretches
who had drawn a bow upon a stag were to be tied to the animal alive; and
among the seigniors it was a standing excuse for having killed game on
forbidden ground, that they aimed at a serf." The feudal lords enforced
these codes with unrelenting rigor, and not unfrequently took the law into
their own hands. In the time of Louis IX., according to William of Nangis,
they planted them with trees, though the protection afforded to them by the
game laws would, if cattle had been kept out, soon have converted them
into real woods.] to be reserved as a hunting-ground for himself and his
posterity, and he punished with death the killing of a deer, wild boar, or
even a hare. His successor, William Rufus, according to the Histoire des
Ducs de Normandie et des Rois d'Angleterre, p. 67, "was hunting one day in
a new forest, which he had caused to be made out of eighteen parishes that
he had destroyed, when, by mischance, he was killed by an arrow
wherewith Tyreus de Rois [Sir Walter Tyrell] thought to slay a beast, but
missed the beast, and slew the king, who was beyond it. And in this very
same forest, his brother Richard ran so hard against a tree that he died of it.
And men commonly said that these things were because they had so laid
waste and taken the said parishes."
These barbarous acts, as Bonnemere observes, [Footnote: Histoire des
Paysans, ii., p. 190. The work of Bonnemere is of great value to those who
study the history of mediaeval Europe from a desire to know its real
character, and not in the hope of finding apparent facts to sustain a false and
dangerous theory. Bonnemere is one of the few writers who, like Michelet,
have been honest enough and bold enough to speak the truth with regard to
the relations between the church and the people in the Middle Ages.] were
simply the transfer of the customs of the French kings, of their vassals, and
even of inferior gentlemen, to conquered England. "The death of a hare,"
says our author, "was a hanging matter, the murder of a plover a capital
crime. Death was inflicted on those who spread nets for pigeons; wretches
who had drawn a bow upon a stag were to be tied to the animal alive; and
among the seigniors it was a standing excuse for having killed game on
forbidden ground, that they aimed at a serf." The feudal lords enforced
these codes with unrelenting rigor, and not unfrequently took the law into
their own hands. In the time of Louis IX., according to William of Nangis,
Page 443
"three noble children, born in Flanders, who were sojourning at the abbey
of St. Nicholas in the Wood, to learn the speech of France, went out into the
forest of the abbey, with their bows and iron-headed arrows, to disport them
in shooting hares, chased the game, which they had started in the wood of
the abbey, into the forest of Enguerrand, lord of Coucy, and were taken by
the sergeants which kept the wood. When the fell and pitiless Sir
Enguerrand knew this, he had the children straightway hanged without any
manner of trial." [Footnote: It is painful to add that a similar outrage was
perpetrated a very few years ago, in one of the European states, by a prince
of a family now dethroned. In this case, however, the prince killed the
trespasser with his own hand, his sergeants refusing to execute his
mandate.] The matter being brought to the notice of good King Louis, Sir
Enguerrand was summoned to appear, and, finally, after many feudal shifts
and dilatory pleas, brought to trial before Louis himself and a special
council. Notwithstanding the opposition of the other seigniors, who, it is
needless to say, spared no efforts to save a peer, probably not a greater
criminal than themselves, the king was much inclined to inflict the
punishment of death on the proud baron. "If he believed," said he, "that our
Lord would be as well content with hanging as with pardoning, he would
hang Sir Enguerrand in spite of all his barons;" but noble and clerical
interests unfortunately prevailed. The king was persuaded to inflict a milder
retribution, and the murderer was condemned to pay ten thousand livres in
coin, and to "build for the souls of the three children two chapels wherein
mass should be said every day." [Footnote: Guillame De Nangis, as quoted
in the notes to Joinville, Nouvelle Collection des Memoires, etc., par
Michaud et Poujoulat, premiere serie, i., p. 335. Persons acquainted with the
character and influence of the mediaeval clergy will hardly need to be
informed that the ten thousand livres never found their way to the royal
exchequer. It was easy to prove to the simple-minded king that, as the
profits of sin were a monopoly of the church, he ought not to derive
of St. Nicholas in the Wood, to learn the speech of France, went out into the
forest of the abbey, with their bows and iron-headed arrows, to disport them
in shooting hares, chased the game, which they had started in the wood of
the abbey, into the forest of Enguerrand, lord of Coucy, and were taken by
the sergeants which kept the wood. When the fell and pitiless Sir
Enguerrand knew this, he had the children straightway hanged without any
manner of trial." [Footnote: It is painful to add that a similar outrage was
perpetrated a very few years ago, in one of the European states, by a prince
of a family now dethroned. In this case, however, the prince killed the
trespasser with his own hand, his sergeants refusing to execute his
mandate.] The matter being brought to the notice of good King Louis, Sir
Enguerrand was summoned to appear, and, finally, after many feudal shifts
and dilatory pleas, brought to trial before Louis himself and a special
council. Notwithstanding the opposition of the other seigniors, who, it is
needless to say, spared no efforts to save a peer, probably not a greater
criminal than themselves, the king was much inclined to inflict the
punishment of death on the proud baron. "If he believed," said he, "that our
Lord would be as well content with hanging as with pardoning, he would
hang Sir Enguerrand in spite of all his barons;" but noble and clerical
interests unfortunately prevailed. The king was persuaded to inflict a milder
retribution, and the murderer was condemned to pay ten thousand livres in
coin, and to "build for the souls of the three children two chapels wherein
mass should be said every day." [Footnote: Guillame De Nangis, as quoted
in the notes to Joinville, Nouvelle Collection des Memoires, etc., par
Michaud et Poujoulat, premiere serie, i., p. 335. Persons acquainted with the
character and influence of the mediaeval clergy will hardly need to be
informed that the ten thousand livres never found their way to the royal
exchequer. It was easy to prove to the simple-minded king that, as the
profits of sin were a monopoly of the church, he ought not to derive
Page 444
advantage from the commission of a crime by one of his subjects; and the
priests were cunning enough both to secure to themselves the amount of the
fine, and to extort from Louis large additional grants to carry out the
purposes to which they devoted the money. "And though the king did take
the moneys," says the chronicler, "he put them not into his treasury, but
turned them into good works; for he builded therewith the maison-Dieu of
Pontoise, and endowed the same with rents and lands; also the schools and
the dormitory of the friars preachers of Paris, and the monastery of the
Minorite friars."] The hope of shortening the purgatorial term of the young
persons, by the religious rites to be celebrated in the chapels, was doubtless
the consideration which operated most powerfully on the mind of the king;
and Europe lost a great example for the sake of a mass.
The desolation and depopulation, resulting from the extension of the
forest and the enforcement of the game laws, induced several of the French
kings to consent to some relaxation of the severity of these latter. Francis I.,
however, revived their barbarous provisions, and, according to Bonnemere,
even so good a monarch as Henry IV. re-enacted them, and "signed the
sentence of death upon peasants guilty of having defended their fields
against devastation by wild beasts." "A fine of twenty livres," he continues,
"was imposed on every one shooting at pigeons, which, at that time,
swooped down by thousands upon the new-sown fields and devoured the
seed. But let us count even this a progress, for we have seen that the murder
of a pigeon had been a capital crime." [Footnote: Histoire des Paysans, ii.,
p. 200.]
Not only were the slightest trespasses on the forest domain—the cutting
of an oxgoad, for instance—severely punished, but game animals were still
sacred when they had wandered from their native precincts and were
ravaging the fields of the peasantry. A herd of deer or of wild boars often
consumed or trod down a harvest of grain, the sole hope of the year for a
priests were cunning enough both to secure to themselves the amount of the
fine, and to extort from Louis large additional grants to carry out the
purposes to which they devoted the money. "And though the king did take
the moneys," says the chronicler, "he put them not into his treasury, but
turned them into good works; for he builded therewith the maison-Dieu of
Pontoise, and endowed the same with rents and lands; also the schools and
the dormitory of the friars preachers of Paris, and the monastery of the
Minorite friars."] The hope of shortening the purgatorial term of the young
persons, by the religious rites to be celebrated in the chapels, was doubtless
the consideration which operated most powerfully on the mind of the king;
and Europe lost a great example for the sake of a mass.
The desolation and depopulation, resulting from the extension of the
forest and the enforcement of the game laws, induced several of the French
kings to consent to some relaxation of the severity of these latter. Francis I.,
however, revived their barbarous provisions, and, according to Bonnemere,
even so good a monarch as Henry IV. re-enacted them, and "signed the
sentence of death upon peasants guilty of having defended their fields
against devastation by wild beasts." "A fine of twenty livres," he continues,
"was imposed on every one shooting at pigeons, which, at that time,
swooped down by thousands upon the new-sown fields and devoured the
seed. But let us count even this a progress, for we have seen that the murder
of a pigeon had been a capital crime." [Footnote: Histoire des Paysans, ii.,
p. 200.]
Not only were the slightest trespasses on the forest domain—the cutting
of an oxgoad, for instance—severely punished, but game animals were still
sacred when they had wandered from their native precincts and were
ravaging the fields of the peasantry. A herd of deer or of wild boars often
consumed or trod down a harvest of grain, the sole hope of the year for a
Page 445
whole family; and the simple driving out of such animals from this costly
pasturage brought dire vengeance on the head of the rustic, who had
endeavored to save his children's bread from their voracity. "At all times,"
says Paul Louis Courier, speaking in the name of the peasants of Chambord,
in the "Simple Discours," "the game has made war upon us. Paris was
blockaded eight hundred years by the deer, and its environs, now so rich, so
fertile, did not yield bread enough to support the gamekeepers." [Footnote:
The following details from Bonnemere will serve to give a more complete
idea of the vexatious and irritating nature of the game laws of France. The
officers of the chase went so far as to forbid the pulling up of thistles and
weeds, or the mowing of any unenclosed ground before St. John's day (24th
June), in order that the nests of game birds might not be disturbed. It was
unlawful to fence-in any grounds in the plains where royal residences were
situated; thorns were ordered to be planted in all fields of wheat, barley, or
oats, to prevent the use of ground-nets for catching the birds which
consumed, or were believed to consume, the grain, and it was forbidden to
cut or pull stubble before the first of October, lest the partridge and the quail
might be deprived of their cover. For destroying the eggs of the quail, a fine
of one hundred livres was imposed for the first offence, double that amount
for the second, and for the third the culprit was flogged and banished for
five years to a distance of six leagues from the forest.—Histoire des
Paysans, ii., p. 202, text and notes.
Neither these severe penalties, nor any provisions devised by the
ingenuity of modern legislation, have been able effectually to repress
poaching. "The game laws," says Clave, "have not delivered us from the
poachers, who kill twenty times as much game as the sportsmen. In the
forest of Fontainebleau, as in all those belonging to the state, poaching is a
very common and a very profitable offence. It is in vain that the
gamekeepers are on the alert night and day, they cannot prevent it. Those
who follow the trade begin by carefully studying the habits of the game.
pasturage brought dire vengeance on the head of the rustic, who had
endeavored to save his children's bread from their voracity. "At all times,"
says Paul Louis Courier, speaking in the name of the peasants of Chambord,
in the "Simple Discours," "the game has made war upon us. Paris was
blockaded eight hundred years by the deer, and its environs, now so rich, so
fertile, did not yield bread enough to support the gamekeepers." [Footnote:
The following details from Bonnemere will serve to give a more complete
idea of the vexatious and irritating nature of the game laws of France. The
officers of the chase went so far as to forbid the pulling up of thistles and
weeds, or the mowing of any unenclosed ground before St. John's day (24th
June), in order that the nests of game birds might not be disturbed. It was
unlawful to fence-in any grounds in the plains where royal residences were
situated; thorns were ordered to be planted in all fields of wheat, barley, or
oats, to prevent the use of ground-nets for catching the birds which
consumed, or were believed to consume, the grain, and it was forbidden to
cut or pull stubble before the first of October, lest the partridge and the quail
might be deprived of their cover. For destroying the eggs of the quail, a fine
of one hundred livres was imposed for the first offence, double that amount
for the second, and for the third the culprit was flogged and banished for
five years to a distance of six leagues from the forest.—Histoire des
Paysans, ii., p. 202, text and notes.
Neither these severe penalties, nor any provisions devised by the
ingenuity of modern legislation, have been able effectually to repress
poaching. "The game laws," says Clave, "have not delivered us from the
poachers, who kill twenty times as much game as the sportsmen. In the
forest of Fontainebleau, as in all those belonging to the state, poaching is a
very common and a very profitable offence. It is in vain that the
gamekeepers are on the alert night and day, they cannot prevent it. Those
who follow the trade begin by carefully studying the habits of the game.
Page 446
They will lie motionless on the ground, by the roadside or in thickets, for
whole days, watching the paths most frequented by the animals," etc.—
Revue des Deux Mondes, Mai, 1863, p. 160.
The writer adds many details on this subject, and it appears that, as there
are "beggars on horseback" in South America, there are poachers in
carriages in France.] The Tiers Etat declared, in 1789, "the most terrible
scourge of agriculture is the abundance of wild game, a consequence of the
privileges of the chase; the fields are wasted, the forests ruined, and the
vines gnawed down to the roots."
Effects of the French Revolution.
The abrogation of the game laws and of the harsh provisions of the
forestal code was one of the earliest measures of the revolutionary
government; and the removal of the ancient restrictions on the chase and of
the severe penalties imposed on trespassers upon the public forests, was
immediately followed by unbridled license in the enjoyment of the newly
conceded rights.
In the popular mind the forest was associated with all the abuses of
feudalism, and the evils the peasantry had suffered from the legislation
which protected both it and the game it sheltered, blinded them to the still
greater physical mischiefs which its destruction was to entail upon them.
No longer under the safeguard of the law, the crown forests and those of the
great lords were attacked with relentless fury, unscrupulously plundered and
wantonly laid waste, and even the rights of property in small private woods
ceased to be respected. [Footnote: "Whole trees were sacrificed for the most
insignificant purposes; the peasants would cut down two firs to make a
single pair of wooden shoes."—Michelet, as quoted by Clave. Etudes, p. 24.
whole days, watching the paths most frequented by the animals," etc.—
Revue des Deux Mondes, Mai, 1863, p. 160.
The writer adds many details on this subject, and it appears that, as there
are "beggars on horseback" in South America, there are poachers in
carriages in France.] The Tiers Etat declared, in 1789, "the most terrible
scourge of agriculture is the abundance of wild game, a consequence of the
privileges of the chase; the fields are wasted, the forests ruined, and the
vines gnawed down to the roots."
Effects of the French Revolution.
The abrogation of the game laws and of the harsh provisions of the
forestal code was one of the earliest measures of the revolutionary
government; and the removal of the ancient restrictions on the chase and of
the severe penalties imposed on trespassers upon the public forests, was
immediately followed by unbridled license in the enjoyment of the newly
conceded rights.
In the popular mind the forest was associated with all the abuses of
feudalism, and the evils the peasantry had suffered from the legislation
which protected both it and the game it sheltered, blinded them to the still
greater physical mischiefs which its destruction was to entail upon them.
No longer under the safeguard of the law, the crown forests and those of the
great lords were attacked with relentless fury, unscrupulously plundered and
wantonly laid waste, and even the rights of property in small private woods
ceased to be respected. [Footnote: "Whole trees were sacrificed for the most
insignificant purposes; the peasants would cut down two firs to make a
single pair of wooden shoes."—Michelet, as quoted by Clave. Etudes, p. 24.
Page 447
A similar wastefulness formerly prevailed in Russia, though not from the
same cause. In St. Pierre's time, the planks brought to St. Petersburg were
not sawn, but hewn with the axe, and a tree furnished but a single plank.]
Various absurd theories, some of which are not even yet exploded, were
propagated with regard to the economical advantages of converting the
forest into pasture and plough-land, the injurious effects of the woods upon
climate, health, facility of internal communication, and the like. Thus
resentful memory of the wrongs associated with the forest, popular
ignorance, and the cupidity of speculators cunning enough to turn these
circumstances to profitable account, combined to hasten the sacrifice of the
remaining woods, and a waste was produced which hundreds of years and
millions of treasure will hardly repair.
In the era of savage anarchy which followed the beneficent reforms of
1789, economical science was neglected, and statistical details upon the
amount of the destruction of woods during that period are wanting. But it is
known to have been almost incalculably rapid, and the climatic and
financial evils, which elsewhere have been a more gradual effect of this
cause, began to make themselves felt in France within three or four years
after that memorable epoch. [Footnote: See Becquerel, Memoire sur les
Forets, in the Mem. de l'Academie des Sciences, c. XXXV., p. 411 et seqq.
Similar circumstances produced a like result, though on a far smaller
scale, in Italy, at a very recent period. Gallenga says: "The destruction of
the majestic timber [between the Vals Sesia and Sessera] dates no farther
back than 1848, when, on the first proclamation of the Constitution, the
ignorant boor had taken it for granted that all the old social ties would be
loosened, and therefore the old forest-laws should be at once set at
naught."—Country Life in Piedmont, p. 136.]
Increased Demand for Lumber.
same cause. In St. Pierre's time, the planks brought to St. Petersburg were
not sawn, but hewn with the axe, and a tree furnished but a single plank.]
Various absurd theories, some of which are not even yet exploded, were
propagated with regard to the economical advantages of converting the
forest into pasture and plough-land, the injurious effects of the woods upon
climate, health, facility of internal communication, and the like. Thus
resentful memory of the wrongs associated with the forest, popular
ignorance, and the cupidity of speculators cunning enough to turn these
circumstances to profitable account, combined to hasten the sacrifice of the
remaining woods, and a waste was produced which hundreds of years and
millions of treasure will hardly repair.
In the era of savage anarchy which followed the beneficent reforms of
1789, economical science was neglected, and statistical details upon the
amount of the destruction of woods during that period are wanting. But it is
known to have been almost incalculably rapid, and the climatic and
financial evils, which elsewhere have been a more gradual effect of this
cause, began to make themselves felt in France within three or four years
after that memorable epoch. [Footnote: See Becquerel, Memoire sur les
Forets, in the Mem. de l'Academie des Sciences, c. XXXV., p. 411 et seqq.
Similar circumstances produced a like result, though on a far smaller
scale, in Italy, at a very recent period. Gallenga says: "The destruction of
the majestic timber [between the Vals Sesia and Sessera] dates no farther
back than 1848, when, on the first proclamation of the Constitution, the
ignorant boor had taken it for granted that all the old social ties would be
loosened, and therefore the old forest-laws should be at once set at
naught."—Country Life in Piedmont, p. 136.]
Increased Demand for Lumber.
Page 448
With increasing population and the development of new industries, come
new drains upon the forest from the many arts for which wood is the
material. The demands of the near and the distant market for this product
excite the cupidity of the hardy forester, and a few years of that wild
industry of which Springer's "Forest Life and Forest Trees" so vividly
depicts the dangers and the triumphs, suffice to rob the most inaccessible
glens of their fairest ornaments. The value of timber increases with its
dimensions in almost geometrical proportion, and the tallest, most vigorous,
and most symmetrical trees fall the first sacrifice. This is a fortunate
circuinritiinco for the remainder of the wood; for the impatient lumberman
contents himself with felling a few of the best trees, and then hurries on to
take his tithe of still virgin groves.
The vast extension of railroads, of manufactures and the mechanical arts,
of military armaments, and especially of the commercial fleets and navies
of Christendom, within the present century, has incredibly augmented the
demand for wood, [Footnote: Let us take the supply of timber for railroad-
ties. According to Clave (p. 248), France had, in 1862, 9,000 kilometres of
railway in operation, 7,000 in construction, half of which is built with a
double track. Adding turn-outs and extra tracks at stations, the number of
ties required for a single track is stated at 1,200 to the kilometre, or, as
Clave computes, for the entire network of France, 58,000,000. This number
is too large, for 16,000 + 8,000 for the double track halfway = 24,000, and
24,000 x 1,200 = 28,800,000. In an article in the Revue des Deux Mondes,
July, 1863, Gandy states that 2,000,000 trees had been felled to furnish the
ties for the French railroads, and as the ties must be occasionally renewed,
and new railways have been constructed since 1863, we may probably
double this number.
The United States had in operation on the first of January, 1872, 61,000
miles, or about 97,000 kilometres, of railroad. Allowing the same
new drains upon the forest from the many arts for which wood is the
material. The demands of the near and the distant market for this product
excite the cupidity of the hardy forester, and a few years of that wild
industry of which Springer's "Forest Life and Forest Trees" so vividly
depicts the dangers and the triumphs, suffice to rob the most inaccessible
glens of their fairest ornaments. The value of timber increases with its
dimensions in almost geometrical proportion, and the tallest, most vigorous,
and most symmetrical trees fall the first sacrifice. This is a fortunate
circuinritiinco for the remainder of the wood; for the impatient lumberman
contents himself with felling a few of the best trees, and then hurries on to
take his tithe of still virgin groves.
The vast extension of railroads, of manufactures and the mechanical arts,
of military armaments, and especially of the commercial fleets and navies
of Christendom, within the present century, has incredibly augmented the
demand for wood, [Footnote: Let us take the supply of timber for railroad-
ties. According to Clave (p. 248), France had, in 1862, 9,000 kilometres of
railway in operation, 7,000 in construction, half of which is built with a
double track. Adding turn-outs and extra tracks at stations, the number of
ties required for a single track is stated at 1,200 to the kilometre, or, as
Clave computes, for the entire network of France, 58,000,000. This number
is too large, for 16,000 + 8,000 for the double track halfway = 24,000, and
24,000 x 1,200 = 28,800,000. In an article in the Revue des Deux Mondes,
July, 1863, Gandy states that 2,000,000 trees had been felled to furnish the
ties for the French railroads, and as the ties must be occasionally renewed,
and new railways have been constructed since 1863, we may probably
double this number.
The United States had in operation on the first of January, 1872, 61,000
miles, or about 97,000 kilometres, of railroad. Allowing the same
Page 449
proportion as in France, the American railroads required 116,400,000 ties.
The Report of the Agricultural Department of the United States for
November and December, 1869, estimates the number of ties annually
required for our railways at 30,000,000, and supposes that 150,000 acres of
the best woodland must be felled to supply this number. This is evidently an
error, perhaps a misprint for 15,000. The same authority calculates the
annual expenditure of the American railroads for lumber for buildings,
repairs, and cars, at $38,000,000, and for locomotive fuel, at the rate of
10,000 cords of wood per day, at $50,000,000.
The walnut trees cut in Italy and France to furnish gunstocks to the
American army, during our late civil war, would alone have formed a
considerable forest. A single establishment in Northern Italy used twenty-
eight thousand large walnut trees for that purpose in the years 1862 and
1863.
The consumption of wood for lucifer matches is enormous, and I have
heard of several instances where tracts of pine forest, hundreds and even
thousands of acres in extent, have been purchased and felled, solely to
supply timber for this purpose. The United States government tax, at one
cent per hundred, produces $2,000,000 per year, which shows a
manufacture of 20,000,000,000 matches. Allowing nothing for waste, there
are about fifty matches to the cubic inch of wood, or 86,400 to the cubic
foot, making in all upwards of 230,000 cubic feet, and, as only straight-
grained wood, free from knots, can be used for this purpose, the sacrifice of
not less than three or four thousand well-grown pines is required for this
purpose.
If we add to all this the supply of wood for telegraph-posts, wooden
pavements, wooden wall tapestry-paper, shoe-pegs, and even wooden nails,
which have lately come into use—not to speak of numerous other recent
The Report of the Agricultural Department of the United States for
November and December, 1869, estimates the number of ties annually
required for our railways at 30,000,000, and supposes that 150,000 acres of
the best woodland must be felled to supply this number. This is evidently an
error, perhaps a misprint for 15,000. The same authority calculates the
annual expenditure of the American railroads for lumber for buildings,
repairs, and cars, at $38,000,000, and for locomotive fuel, at the rate of
10,000 cords of wood per day, at $50,000,000.
The walnut trees cut in Italy and France to furnish gunstocks to the
American army, during our late civil war, would alone have formed a
considerable forest. A single establishment in Northern Italy used twenty-
eight thousand large walnut trees for that purpose in the years 1862 and
1863.
The consumption of wood for lucifer matches is enormous, and I have
heard of several instances where tracts of pine forest, hundreds and even
thousands of acres in extent, have been purchased and felled, solely to
supply timber for this purpose. The United States government tax, at one
cent per hundred, produces $2,000,000 per year, which shows a
manufacture of 20,000,000,000 matches. Allowing nothing for waste, there
are about fifty matches to the cubic inch of wood, or 86,400 to the cubic
foot, making in all upwards of 230,000 cubic feet, and, as only straight-
grained wood, free from knots, can be used for this purpose, the sacrifice of
not less than three or four thousand well-grown pines is required for this
purpose.
If we add to all this the supply of wood for telegraph-posts, wooden
pavements, wooden wall tapestry-paper, shoe-pegs, and even wooden nails,
which have lately come into use—not to speak of numerous other recent
Page 450
applications of this material which American ingenuity has devised—we
have an amount of consumption, for entirely new purposes, which is really
appalling.
Wooden field and garden fences are very generally used in America, and
some have estimated the consumption of wood for this purpose as not less
than that for architectural uses.
Fully one-half our vast population is lodged in wooden houses, and barns
and country out-houses of all descriptions are almost universally of the
same material.
The consumption of wood in the United States as fuel for domestic
purposes, for charcoal, for brick and lime kilns, for breweries and
distilleries, for steamboats, and many other uses, defies computation, and is
vastly greater than is employed in Europe for the same ends. For instance,
in rural Switzerland, cold as is the winter climate, the whole supply of wood
for domestic fires, dairies, breweries, distilleries, brick and lime kilns,
fences, furniture, tools, and even house-building and small smitheries,
exclusive of the small quantity derived from the trimmings of fruit-trees,
grape-vines, and hedges, and from decayed fences and buildings, does not
exceed TWO HUNDRED AND THIRTY CUBIC FEET, or less than two
cords a year, per household.—See Bericht uber die Untersuchung der
Schweiz Hochgebirgswaldungen, pp. 85-89. In 1789, Arthur Young
estimated the annual consumption of firewood by single families in France
at from two and a half to ten Paris cords of 134 cubic feet.—Travels, vol.
ii., chap. xv.
The report of the Commissioners on the Forests of Wisconsin, 1867,
allows three cords of wood to each person for household fires alone. Taking
families at an average of five persons, we have eight times the amount
consumed by an equal number of persons in Switzerland for this and all
have an amount of consumption, for entirely new purposes, which is really
appalling.
Wooden field and garden fences are very generally used in America, and
some have estimated the consumption of wood for this purpose as not less
than that for architectural uses.
Fully one-half our vast population is lodged in wooden houses, and barns
and country out-houses of all descriptions are almost universally of the
same material.
The consumption of wood in the United States as fuel for domestic
purposes, for charcoal, for brick and lime kilns, for breweries and
distilleries, for steamboats, and many other uses, defies computation, and is
vastly greater than is employed in Europe for the same ends. For instance,
in rural Switzerland, cold as is the winter climate, the whole supply of wood
for domestic fires, dairies, breweries, distilleries, brick and lime kilns,
fences, furniture, tools, and even house-building and small smitheries,
exclusive of the small quantity derived from the trimmings of fruit-trees,
grape-vines, and hedges, and from decayed fences and buildings, does not
exceed TWO HUNDRED AND THIRTY CUBIC FEET, or less than two
cords a year, per household.—See Bericht uber die Untersuchung der
Schweiz Hochgebirgswaldungen, pp. 85-89. In 1789, Arthur Young
estimated the annual consumption of firewood by single families in France
at from two and a half to ten Paris cords of 134 cubic feet.—Travels, vol.
ii., chap. xv.
The report of the Commissioners on the Forests of Wisconsin, 1867,
allows three cords of wood to each person for household fires alone. Taking
families at an average of five persons, we have eight times the amount
consumed by an equal number of persons in Switzerland for this and all
Page 451
other purposes to which this material in ordinarily applicable. I do not think
the consumption in the North-eastern States is at all less than the calculation
for Wisconsin. Evergreen trees are often destroyed in immense numbers in
the United States for the purpose of decoration of churches and on other
festive occasions. The New York city papers reported that 113,000 young
evergreen trees, besides 20,000 yards of small branches twirled into
festoons, were sold in the markets of that city, for this use, at Christmas, in
1869. At the Cincinnati Industrial Exhibition of 1873, three miles of
evergreen festoons were hung upon the beams and rafters of the "Floral
Hall."
Important statistics on the consumption and supply of wood in the United
States will be found in a valuable paper by the Rev. Frederick Starr,
Jr., in the Transactions of the Agricultural Society for—.
Of course, there is a vast consumption of ligneous material for all these
uses in Europe, but it is greatly less than at earlier periods. The waste of
wood in European carpentry was formerly enormous, the beams of houses
being both larger and more numerous than permanence or stability required.
In examining the construction of the houses occupied by the eighty families
which inhabit the village of Faucigny, in Savoy, in 1854, the forest
inspector found that FIFTY THOUSAND trees had been employed in
building them. The builders "seemed," says Hudry-Menos, "to have tried to
solve the problem of piling upon the walls the largest quantity of timber
possible without crushing them."—Revue des Deux Mondes, 1st June,
1864, p. 601.
European statistics present comparatively few facts on this subject, of
special interest to American readers, but it is worth noting that France
employs 1,500,000 cubic feet of oak per year for brandy and wine casks,
which is about half her annual consumption of that material; and it is not a
the consumption in the North-eastern States is at all less than the calculation
for Wisconsin. Evergreen trees are often destroyed in immense numbers in
the United States for the purpose of decoration of churches and on other
festive occasions. The New York city papers reported that 113,000 young
evergreen trees, besides 20,000 yards of small branches twirled into
festoons, were sold in the markets of that city, for this use, at Christmas, in
1869. At the Cincinnati Industrial Exhibition of 1873, three miles of
evergreen festoons were hung upon the beams and rafters of the "Floral
Hall."
Important statistics on the consumption and supply of wood in the United
States will be found in a valuable paper by the Rev. Frederick Starr,
Jr., in the Transactions of the Agricultural Society for—.
Of course, there is a vast consumption of ligneous material for all these
uses in Europe, but it is greatly less than at earlier periods. The waste of
wood in European carpentry was formerly enormous, the beams of houses
being both larger and more numerous than permanence or stability required.
In examining the construction of the houses occupied by the eighty families
which inhabit the village of Faucigny, in Savoy, in 1854, the forest
inspector found that FIFTY THOUSAND trees had been employed in
building them. The builders "seemed," says Hudry-Menos, "to have tried to
solve the problem of piling upon the walls the largest quantity of timber
possible without crushing them."—Revue des Deux Mondes, 1st June,
1864, p. 601.
European statistics present comparatively few facts on this subject, of
special interest to American readers, but it is worth noting that France
employs 1,500,000 cubic feet of oak per year for brandy and wine casks,
which is about half her annual consumption of that material; and it is not a
Page 452
wholly insignificant fact that, according to Rentzach, the quantity of wood
used in parts of Germany for small carvings and for children's toys is so
largs, that the export of such objects from the town of Sonneberg alone,
amounted, in 1853, to 60,000 centner, or three thousand tons' weight.—Der
Wald, p. 68.
In an article in the Revue des Eaux et Forets for November, 1868, it is
stated that 200,000 dozens of drums for boys aro manufactured per month
in Paris. This is equivalent to 28,800,000 per year, for which 56,000,000
drumsticks are required, and the writer supposes that the annual growth of
50,000 acres of woodland would not more than supply the material. In the
same article the consumption of matches in France is given at
7,200,000,000, and the quantity of lumber annually required for this
manufacture is computed at 80,000 steres, or cubic metres—evidently an
erroneous calculation.] and but for improvements in metallurgy and the
working of iron, which have facilitated the substitution of that metal for
wood, the last twenty-five years would have almost stripped Europe of her
last remaining tree fit for these uses. [Footnote: Besides the substitution of
iron for wood, a great saving of consumption of this latter material has been
effected by the revival of ancient methods of increasing its durability, and
the invention of new processes for the same purpose. The most effectual
preservative yet discovered for wood employed on land, is sulphate of
copper, a solution of which is introduced into the pores of the wood while
green, by soaking, by forcing-pumps, or, most economically, by the simple
pressure of a column of the fluid in a small pipe connected with the end of
the piece of timber subjected to the treatment. Clave (Etudes Forestieres,
pp. 240-249) gives an interesting account of the various processes
employed for rendering wood imperishable, and states that railroad-ties
injected with sulphate of copper in 1846, were found absolutely unaltered in
1855; and telegraphic posts prepared two years earlier, are now in a state of
perfect preservation.
used in parts of Germany for small carvings and for children's toys is so
largs, that the export of such objects from the town of Sonneberg alone,
amounted, in 1853, to 60,000 centner, or three thousand tons' weight.—Der
Wald, p. 68.
In an article in the Revue des Eaux et Forets for November, 1868, it is
stated that 200,000 dozens of drums for boys aro manufactured per month
in Paris. This is equivalent to 28,800,000 per year, for which 56,000,000
drumsticks are required, and the writer supposes that the annual growth of
50,000 acres of woodland would not more than supply the material. In the
same article the consumption of matches in France is given at
7,200,000,000, and the quantity of lumber annually required for this
manufacture is computed at 80,000 steres, or cubic metres—evidently an
erroneous calculation.] and but for improvements in metallurgy and the
working of iron, which have facilitated the substitution of that metal for
wood, the last twenty-five years would have almost stripped Europe of her
last remaining tree fit for these uses. [Footnote: Besides the substitution of
iron for wood, a great saving of consumption of this latter material has been
effected by the revival of ancient methods of increasing its durability, and
the invention of new processes for the same purpose. The most effectual
preservative yet discovered for wood employed on land, is sulphate of
copper, a solution of which is introduced into the pores of the wood while
green, by soaking, by forcing-pumps, or, most economically, by the simple
pressure of a column of the fluid in a small pipe connected with the end of
the piece of timber subjected to the treatment. Clave (Etudes Forestieres,
pp. 240-249) gives an interesting account of the various processes
employed for rendering wood imperishable, and states that railroad-ties
injected with sulphate of copper in 1846, were found absolutely unaltered in
1855; and telegraphic posts prepared two years earlier, are now in a state of
perfect preservation.
Page 453
For many purposes, the method of injection is too expensive, and some
simpler process is much to be desired. The question of the proper time of
felling timber is not settled, and the best modes of air, water, and steam
seasoning are not yet fully ascertained. Experiments on these subjects
would be well worth the patronage of Governments in new countries, where
they can be very easily made, without the necessity of much waste of
valuable material, and without expensive arrangements for observation.
The practice of stripping living trees of their bark some years before they
are felled, is as old as the time of Vitruvius, but is much less followed than
it deserves, partly because the timber of trees so treated inclines to crack
and split, and partly because it becomes so hard as to be wrought with
considerable difficulty.
In America, economy in the consumption of fuel has been much
promoted by the substitution of coal for wood, the general use of stoves
both for wood and coal, and recently by the employment of anthracite in the
furnaces of stationary and locomotive steam-engines. All the objections to
the use of anthracite for this latter purpose appear to have been overcome,
and the improvements in its combustion have been attended with a great
pecuniary saving, and with much advantage to the preservation of the
woods.
The employment of coal has produced a great reduction in the
consumption of firewood in Paris. In 1815, the supply of firewood for the
city required 1,200,000 steres, or cubic metres; in 1859 it had fallen to
501,805, while, in the meantime, the consumption of coal had risen from
600,000 to 4,320,000 metrical quintals. See Clave, Etudes, p. 212.
In 1869 Paris consumed 951,157 steres of firewood, 4,902,414
hectolitres, or more than 13,000,000 bushels, of charcoal, and 6,872,000
simpler process is much to be desired. The question of the proper time of
felling timber is not settled, and the best modes of air, water, and steam
seasoning are not yet fully ascertained. Experiments on these subjects
would be well worth the patronage of Governments in new countries, where
they can be very easily made, without the necessity of much waste of
valuable material, and without expensive arrangements for observation.
The practice of stripping living trees of their bark some years before they
are felled, is as old as the time of Vitruvius, but is much less followed than
it deserves, partly because the timber of trees so treated inclines to crack
and split, and partly because it becomes so hard as to be wrought with
considerable difficulty.
In America, economy in the consumption of fuel has been much
promoted by the substitution of coal for wood, the general use of stoves
both for wood and coal, and recently by the employment of anthracite in the
furnaces of stationary and locomotive steam-engines. All the objections to
the use of anthracite for this latter purpose appear to have been overcome,
and the improvements in its combustion have been attended with a great
pecuniary saving, and with much advantage to the preservation of the
woods.
The employment of coal has produced a great reduction in the
consumption of firewood in Paris. In 1815, the supply of firewood for the
city required 1,200,000 steres, or cubic metres; in 1859 it had fallen to
501,805, while, in the meantime, the consumption of coal had risen from
600,000 to 4,320,000 metrical quintals. See Clave, Etudes, p. 212.
In 1869 Paris consumed 951,157 steres of firewood, 4,902,414
hectolitres, or more than 13,000,000 bushels, of charcoal, and 6,872,000
Page 454
metrical quintals, or more than 7,000,000 tons of mineral coal.—Annuaire
de la Revue des Eaux et Forets for 1872, p. 26.
The increase in the price of firewood at Paris, within a century, has been
comparatively small, while that of timber and of sawed lumber has
increased enormously.] I have spoken of the foreign demand for American
agricultural products as having occasioned an extension of cultivated
ground, which had led to clearing land not required by the necessities of
home consumption. But the forest itself has become, so to speak, an article
of exportation. England, as we have seen, imported oak and pine from the
Baltic ports more than six hundred years ago. She has since drawn largely
on the forests of Norway, and for many years has received vast quantities of
lumber from her American possessions.
The unparalleled facilities for internal navigation, afforded by the
numerous rivers of the present and former British colonial possessions in
North America, have proved very fatal to the forests of that continent.
Quebec became many years ago a centre for a lumber trade, which, in the
bulk of its material, and, consequently, in the tonnage required for its
transportation, rivalled the commerce of the greatest European cities.
Immense rafts were collected at Quebec from the great Lakes, from the
Ottawa, and from all the other tributaries which unite to swell the current of
the St. Lawrence and help it to struggle against its mighty tides. [Footnote:
The tide rises at Quebec to the height of twenty-five feet, and when it is
aided by a north-east wind, it flows with almost irresistible violence. Rafts
containing several hundred thousand cubic feet of timber are often caught
by the flood-tide, torn to pieces, and dispersed for miles along the shores.]
Ships, of burden formerly undreamed of, have been built to convey the
timber to the markets of Europe, and during the summer months the St.
Lawrence is almost as crowded with shipping as the Thames. [Footnote:
One of these, the Baron of Renfrew—so named from one of the titles of the
de la Revue des Eaux et Forets for 1872, p. 26.
The increase in the price of firewood at Paris, within a century, has been
comparatively small, while that of timber and of sawed lumber has
increased enormously.] I have spoken of the foreign demand for American
agricultural products as having occasioned an extension of cultivated
ground, which had led to clearing land not required by the necessities of
home consumption. But the forest itself has become, so to speak, an article
of exportation. England, as we have seen, imported oak and pine from the
Baltic ports more than six hundred years ago. She has since drawn largely
on the forests of Norway, and for many years has received vast quantities of
lumber from her American possessions.
The unparalleled facilities for internal navigation, afforded by the
numerous rivers of the present and former British colonial possessions in
North America, have proved very fatal to the forests of that continent.
Quebec became many years ago a centre for a lumber trade, which, in the
bulk of its material, and, consequently, in the tonnage required for its
transportation, rivalled the commerce of the greatest European cities.
Immense rafts were collected at Quebec from the great Lakes, from the
Ottawa, and from all the other tributaries which unite to swell the current of
the St. Lawrence and help it to struggle against its mighty tides. [Footnote:
The tide rises at Quebec to the height of twenty-five feet, and when it is
aided by a north-east wind, it flows with almost irresistible violence. Rafts
containing several hundred thousand cubic feet of timber are often caught
by the flood-tide, torn to pieces, and dispersed for miles along the shores.]
Ships, of burden formerly undreamed of, have been built to convey the
timber to the markets of Europe, and during the summer months the St.
Lawrence is almost as crowded with shipping as the Thames. [Footnote:
One of these, the Baron of Renfrew—so named from one of the titles of the
Page 455
kings of England—built forty or fifty years ago, measured 5,000 tons. They
were little else than rafts, being almost solid masses of timber designed to
be taken to pieces and sold as lumber on arriving at their port of destination.
The lumber trade at Quebec is still very large. According to an article in
the Revue des Deux Mondes, that city exported, in 1860, 30,000,000 cubic
feet of squared timber, and 400,000,000 square feet of "planches." The
thickness of the boards is not stated, but I believe they are generally cut an
inch and a quarter thick for the Quebec trade, and as they shrink somewhat
in drying, we may estimate ten square for one cubic foot of boards. This
gives a total of 70,000,000 cubic feet. The specific gravity of white pine is
.554, and the weight of this quantity of lumber, very little of which is
thoroughly seasoned, would exceed a million of tons, even supposing it to
consist wholly of wood as light as pine.
The London Times of Oct. 10, 1871, states the exportation of lumber
from
Canada to Europe, in 1870, at 200,000,000 cubic feet, and adds that more
than three times that quantity was sent from the same province to the
United States. A very large proportion of this latter quantity goes to
Burlington, Vermont, whence it is distributed to other parts of the
Union.
There must, I think, be some error or exaggeration in these figures.
Perhaps instead of cubic feet we should read square feet. Two hundred
millions of cubic feet of timber would require more than half the entire
tonnage of England for its transportation.
I suppose the quantities in the following estimates, from a carefully
prepared article in the St. Louis Republican, must be understood as meaning
square or superficial feet, board measure, allowing a thickness of one inch:
were little else than rafts, being almost solid masses of timber designed to
be taken to pieces and sold as lumber on arriving at their port of destination.
The lumber trade at Quebec is still very large. According to an article in
the Revue des Deux Mondes, that city exported, in 1860, 30,000,000 cubic
feet of squared timber, and 400,000,000 square feet of "planches." The
thickness of the boards is not stated, but I believe they are generally cut an
inch and a quarter thick for the Quebec trade, and as they shrink somewhat
in drying, we may estimate ten square for one cubic foot of boards. This
gives a total of 70,000,000 cubic feet. The specific gravity of white pine is
.554, and the weight of this quantity of lumber, very little of which is
thoroughly seasoned, would exceed a million of tons, even supposing it to
consist wholly of wood as light as pine.
The London Times of Oct. 10, 1871, states the exportation of lumber
from
Canada to Europe, in 1870, at 200,000,000 cubic feet, and adds that more
than three times that quantity was sent from the same province to the
United States. A very large proportion of this latter quantity goes to
Burlington, Vermont, whence it is distributed to other parts of the
Union.
There must, I think, be some error or exaggeration in these figures.
Perhaps instead of cubic feet we should read square feet. Two hundred
millions of cubic feet of timber would require more than half the entire
tonnage of England for its transportation.
I suppose the quantities in the following estimates, from a carefully
prepared article in the St. Louis Republican, must be understood as meaning
square or superficial feet, board measure, allowing a thickness of one inch:
Page 456
"The lumber trade of Michigan, Wisconsin, and Minnesota, for the year
1869, shows the amount cut as being 2,029,372,255 feet for the State of
Michigan, and 317,400,000 feet for the State of Minnesota, and
964,600,000 feet for the State of Wisconsin. This includes the lake shore
and the whole State of Wisconsin, which heretofore has been difficult to get
a report from. The total amount cut in these States was 3,311,372,255 feet,
and that to obtain this quantity there have been shipped 883,032 acres, or
1,380 square miles of pine have been removed. It is calculated that
4,000,000 acres of land still remain unstripped in Michigan, which will
yield 15,000,000,000 feet of lumber; while 3,000,000 acres arc still
standing in Wisconsin, which will yield 11,250,000,000 feet, and that which
remains in Minnesota, taking the estimate of a few years since of that which
was surveyed and unexplored, after deducting the amount cut the past few
years, we find 3,630,000 acres to be the proper estimate of trees now
standing which will yield 32,362,500,000 feet of lumber. This makes a total
of 15,630,000 acres of pine lands, which remain standing in the above
States, that will yield 58,612,500,000 feet of lumber, and it is thought that
fifteen or twenty years will be required to cut and send to market the trees
now standing."
See also Bryant, Forest Trees, chap. iv.]
Effects of Forest Fires.
The operations of the lumberman involve other dangers to the woods
besides the loss of the trees felled by him. The narrow clearings around his
shanties form openings which let in the wind, and thus sometimes occasion
the overthrow of thousands of trees, the fall of which dams up small
streams, and creates bogs by the spreading of the waters, while the decaying
trunks facilitate the multiplication of the insects which breed in dead wood
and are, some of them, injurious to living trees. The escape and spread of
1869, shows the amount cut as being 2,029,372,255 feet for the State of
Michigan, and 317,400,000 feet for the State of Minnesota, and
964,600,000 feet for the State of Wisconsin. This includes the lake shore
and the whole State of Wisconsin, which heretofore has been difficult to get
a report from. The total amount cut in these States was 3,311,372,255 feet,
and that to obtain this quantity there have been shipped 883,032 acres, or
1,380 square miles of pine have been removed. It is calculated that
4,000,000 acres of land still remain unstripped in Michigan, which will
yield 15,000,000,000 feet of lumber; while 3,000,000 acres arc still
standing in Wisconsin, which will yield 11,250,000,000 feet, and that which
remains in Minnesota, taking the estimate of a few years since of that which
was surveyed and unexplored, after deducting the amount cut the past few
years, we find 3,630,000 acres to be the proper estimate of trees now
standing which will yield 32,362,500,000 feet of lumber. This makes a total
of 15,630,000 acres of pine lands, which remain standing in the above
States, that will yield 58,612,500,000 feet of lumber, and it is thought that
fifteen or twenty years will be required to cut and send to market the trees
now standing."
See also Bryant, Forest Trees, chap. iv.]
Effects of Forest Fires.
The operations of the lumberman involve other dangers to the woods
besides the loss of the trees felled by him. The narrow clearings around his
shanties form openings which let in the wind, and thus sometimes occasion
the overthrow of thousands of trees, the fall of which dams up small
streams, and creates bogs by the spreading of the waters, while the decaying
trunks facilitate the multiplication of the insects which breed in dead wood
and are, some of them, injurious to living trees. The escape and spread of
Page 457
camp-fires, however, is the most devastating of all the causes of destruction
that find their origin in the operations of the lumberman. The proportion of
trees fit for industrial uses is small in all primitive woods. Only these fall
before the forester's axe, but the fire destroys, almost indiscriminately,
every age and every species of tree. [Footnote: Trees differ in their power of
resisting the action of forest fires. Different woods vary greatly in
combustibility, and even when the bark is scarcely scorched, trees are,
partly in consequence of physiological character, and partly from the greater
or less depth at which their roots habitually lie below the surface,
differently affected by running fires. The white pine, Pinus strobus, as it is
the most valuable, is also perhaps the most delicate tree of the American
forest, while its congener, the Northern pitch-pine, Pinus rigida, is less
injured by fire than any other tree of that country. I have heard experienced
lumbermen maintain that the growth of this pine was even accelerated by a
fire brisk enough to destroy all other trees, and I have myself seen it still
flourishing after a conflagration which had left not a green leaf but its own
in the wood, and actually throwing out fresh foliage, when the old had been
quite burnt off and the bark almost converted into charcoal. The wood of
the pitch-pine is of comparatively little value for the joiner, but it is useful
for very many purposes. Its rapidity of growth in even poor soils, its
hardihood, and its abundant yield of resinous products, entitle it to much
more consideration, as a plantation tree, than it has hitherto received in
Europe or America.]
While, then, without fatal injury to the younger growths, the native forest
will bear several "cuttings over" in a generation—for the increasing value
of lumber brings into use, every four or five years, a quality of timber
which had been before rejected as unmarketable—a fire may render the
declivity of a mountain unproductive for a century. [Footnote: Between
sixty and seventy years ago, a steep mountain with which I am familiar,
composed of metamorphic rock, and at that time covered with a thick
that find their origin in the operations of the lumberman. The proportion of
trees fit for industrial uses is small in all primitive woods. Only these fall
before the forester's axe, but the fire destroys, almost indiscriminately,
every age and every species of tree. [Footnote: Trees differ in their power of
resisting the action of forest fires. Different woods vary greatly in
combustibility, and even when the bark is scarcely scorched, trees are,
partly in consequence of physiological character, and partly from the greater
or less depth at which their roots habitually lie below the surface,
differently affected by running fires. The white pine, Pinus strobus, as it is
the most valuable, is also perhaps the most delicate tree of the American
forest, while its congener, the Northern pitch-pine, Pinus rigida, is less
injured by fire than any other tree of that country. I have heard experienced
lumbermen maintain that the growth of this pine was even accelerated by a
fire brisk enough to destroy all other trees, and I have myself seen it still
flourishing after a conflagration which had left not a green leaf but its own
in the wood, and actually throwing out fresh foliage, when the old had been
quite burnt off and the bark almost converted into charcoal. The wood of
the pitch-pine is of comparatively little value for the joiner, but it is useful
for very many purposes. Its rapidity of growth in even poor soils, its
hardihood, and its abundant yield of resinous products, entitle it to much
more consideration, as a plantation tree, than it has hitherto received in
Europe or America.]
While, then, without fatal injury to the younger growths, the native forest
will bear several "cuttings over" in a generation—for the increasing value
of lumber brings into use, every four or five years, a quality of timber
which had been before rejected as unmarketable—a fire may render the
declivity of a mountain unproductive for a century. [Footnote: Between
sixty and seventy years ago, a steep mountain with which I am familiar,
composed of metamorphic rock, and at that time covered with a thick
Page 458
coating of soil and a dense primeval forest, was accidentally burnt over. The
fire took place in a very dry season, the slope of the mountain was too rapid
to retain much water, and the conflagration was of an extraordinarily fierce
character, consuming the wood almost entirely, burning the leaves and
combustible portion of the mould, and in the many places cracking and
disintegrating the rock beneath. The rains of the following autumn carried
off much of the remaining soil, and the mountain-side was nearly bare of
wood for two or three years afterwards. At length a new crop of trees sprang
up and grew vigorously, and the mountain is now thickly covered again.
But the depth of mould and earth is too small to allow the trees to reach
maturity. When they attain to the diameter of about six inches, they
uniformly die, and this they will no doubt continue to do until the decay of
leaves and wood on the surface, and the decomposition of the subjacent
rock, shall have formed, perhaps hundreds of years hence, a stratum of soil
thick enough to support a full-grown forest. Under favorable conditions,
however, as in the case of the fire of Miramichi, a burnt forest renews itself
rapidly and permanently.]
Aside from the destruction of the trees and the laying bare of the soil, and
consequently the freer admission of sun, rain, and air to the ground, the fire
of itself exerts an important influence on its texture and condition. It cracks
and sometimes even pulverizes the rocks and stones upon and near the
surface; [Footnote: In the burning over of a hill-forest in the Lower
Engadine, in September, 1865, the fire was intense as to shatter and calcine
the rocks on the slope, and their fragments were precipitated into the valley
below.—Ricista Firrestate del Regna d'Italia, Ottobro, 1865, 1865, p. 474.]
it consumes a portion of the half-decayed vegetable mould which served to
hold its mineral particles together and to retain the water of precipitation,
and thus loosens, pulverizes, and dries the earth; it destroys reptiles, insects,
and worms, with their eggs, and the seeds of trees and of smaller plants; it
supplies, in the ashes which it deposits on the surface, important elements
fire took place in a very dry season, the slope of the mountain was too rapid
to retain much water, and the conflagration was of an extraordinarily fierce
character, consuming the wood almost entirely, burning the leaves and
combustible portion of the mould, and in the many places cracking and
disintegrating the rock beneath. The rains of the following autumn carried
off much of the remaining soil, and the mountain-side was nearly bare of
wood for two or three years afterwards. At length a new crop of trees sprang
up and grew vigorously, and the mountain is now thickly covered again.
But the depth of mould and earth is too small to allow the trees to reach
maturity. When they attain to the diameter of about six inches, they
uniformly die, and this they will no doubt continue to do until the decay of
leaves and wood on the surface, and the decomposition of the subjacent
rock, shall have formed, perhaps hundreds of years hence, a stratum of soil
thick enough to support a full-grown forest. Under favorable conditions,
however, as in the case of the fire of Miramichi, a burnt forest renews itself
rapidly and permanently.]
Aside from the destruction of the trees and the laying bare of the soil, and
consequently the freer admission of sun, rain, and air to the ground, the fire
of itself exerts an important influence on its texture and condition. It cracks
and sometimes even pulverizes the rocks and stones upon and near the
surface; [Footnote: In the burning over of a hill-forest in the Lower
Engadine, in September, 1865, the fire was intense as to shatter and calcine
the rocks on the slope, and their fragments were precipitated into the valley
below.—Ricista Firrestate del Regna d'Italia, Ottobro, 1865, 1865, p. 474.]
it consumes a portion of the half-decayed vegetable mould which served to
hold its mineral particles together and to retain the water of precipitation,
and thus loosens, pulverizes, and dries the earth; it destroys reptiles, insects,
and worms, with their eggs, and the seeds of trees and of smaller plants; it
supplies, in the ashes which it deposits on the surface, important elements
Page 459
for the growth of a new forest clothing, as well as of the usual objects of
agricultural industry; and by the changes thus produced, it fits the ground
for the reception of a vegetation different in character from that which had
spontaneously covered it. These new conditions help to explain the natural
succession of forest crops, so generally observed in all woods cleared by
fire and then abandoned. There is no doubt, however, that other influences
contribute to the same result, because effects more or less analogous follow
when the trees are destroyed by other causes, as by high winds, by the
woodman's axe, and even by natural decay. [Footnote: The remarkable
mounds and other earthworks constructed in the valley of the Ohio and
elsewhere in the territory of the United States, by a people apparently more
advanced in the culture than the modern Indian, were overgrown with a
dense clothing of forest when first discovered by the whites. But though the
ground where they were erected must have been occupied by a large
population for a considerable leagth of time, and therefore entirely cleared,
the trees which grew upon the ancient fortresses and the adjacent lands
were not distinguishable in species, or even in dimensions and character of
growth, from the neighboring forests, where the soil seemed never to have
been disturbed. This apparent exception to the law of change of crop in
natured forest growth was ingeniously explained by General Harrison's
suggestion, that the lapse of time since the era of the mound-builders was so
great as to have embraced several successive generations of trees, and
occasioned, by their rotation, a return to the original vegetation.
The succesive changes in the spontaneous growth of the forest, as proved
by the character of the wood found in bogs, are such as to have suggested
the theory of a considerable change of climate during the human period. But
strobus, as it is the most valuable, is also perhaps the most delicate tree of
the American forest, while its congener, the Northern pitch-pine, Pinus
rigida, is less injured by fire than any other tree of that country. I have heard
experienced lumbermen maintain that the growth of this pine was even
agricultural industry; and by the changes thus produced, it fits the ground
for the reception of a vegetation different in character from that which had
spontaneously covered it. These new conditions help to explain the natural
succession of forest crops, so generally observed in all woods cleared by
fire and then abandoned. There is no doubt, however, that other influences
contribute to the same result, because effects more or less analogous follow
when the trees are destroyed by other causes, as by high winds, by the
woodman's axe, and even by natural decay. [Footnote: The remarkable
mounds and other earthworks constructed in the valley of the Ohio and
elsewhere in the territory of the United States, by a people apparently more
advanced in the culture than the modern Indian, were overgrown with a
dense clothing of forest when first discovered by the whites. But though the
ground where they were erected must have been occupied by a large
population for a considerable leagth of time, and therefore entirely cleared,
the trees which grew upon the ancient fortresses and the adjacent lands
were not distinguishable in species, or even in dimensions and character of
growth, from the neighboring forests, where the soil seemed never to have
been disturbed. This apparent exception to the law of change of crop in
natured forest growth was ingeniously explained by General Harrison's
suggestion, that the lapse of time since the era of the mound-builders was so
great as to have embraced several successive generations of trees, and
occasioned, by their rotation, a return to the original vegetation.
The succesive changes in the spontaneous growth of the forest, as proved
by the character of the wood found in bogs, are such as to have suggested
the theory of a considerable change of climate during the human period. But
strobus, as it is the most valuable, is also perhaps the most delicate tree of
the American forest, while its congener, the Northern pitch-pine, Pinus
rigida, is less injured by fire than any other tree of that country. I have heard
experienced lumbermen maintain that the growth of this pine was even
Page 460
accelerated by a fire brisk enough to destroy all other trees, and I have
myself seen it still flourishing after a conflagration which had left not a
green leaf but its own in the wood, and actually throwing out fresh foliage,
when the old had been quite burnt off and the bark almost converted into
charcoal. The wood of the pitch-pine is of comparatively little value for the
joiner, but it is useful for very many purposes. Its rapidity of growth in even
poor soils, its hardihood, and its abundant yield of resinous products, entitle
it to much more consideration, as a plantation tree, than it has hitherto
received in Europe or America.] without fatal injury to the younger
growths, the native forest will hear several "cuttings over" in a generation—
for the increasing value of lumber brings into use, every four or five years,
a quality of timber which had been before rejected as unmarketable—a fire
may render the declivity of a mountain unproductive for a century.
[Footnote: Between sixty and seventy years ago, a steep mountain with
which I am familiar, composed of metamorphic rock, and at that time
covered with a thick coating of soil and a dense primeval forest, was
accidentally burnt over. The fire took place in a very dry season, the slope
of the mountain was too rapid to retain much water, and the conflagration
was of an extraordinarily fierce character, consuming the wood almost
entirely, burning the leaves and combustible portion of the mould, and in
many places cracking and disintegrating the rock beneath. The rains of the
following autumn carried off much of the remaining soil, and the mountain-
side was nearly bare of wood for two or three years afterwards. At length a
new crop of trees sprang up and grew vigorously, and the mountain is now
thickly covered again. But the depth of mould and earth is too small to
allow the trees to reach maturity. When they attain to the diameter of about
six inches, they uniformly die, and this they will no doubt continue to do
until the decay of leaves and wood on the surface, and the decomposition of
the subjacent rock, shall have formed, perhaps hundreds of years hence, a
stratum of soil thick enough to support a full-grown forest. Under favorable
myself seen it still flourishing after a conflagration which had left not a
green leaf but its own in the wood, and actually throwing out fresh foliage,
when the old had been quite burnt off and the bark almost converted into
charcoal. The wood of the pitch-pine is of comparatively little value for the
joiner, but it is useful for very many purposes. Its rapidity of growth in even
poor soils, its hardihood, and its abundant yield of resinous products, entitle
it to much more consideration, as a plantation tree, than it has hitherto
received in Europe or America.] without fatal injury to the younger
growths, the native forest will hear several "cuttings over" in a generation—
for the increasing value of lumber brings into use, every four or five years,
a quality of timber which had been before rejected as unmarketable—a fire
may render the declivity of a mountain unproductive for a century.
[Footnote: Between sixty and seventy years ago, a steep mountain with
which I am familiar, composed of metamorphic rock, and at that time
covered with a thick coating of soil and a dense primeval forest, was
accidentally burnt over. The fire took place in a very dry season, the slope
of the mountain was too rapid to retain much water, and the conflagration
was of an extraordinarily fierce character, consuming the wood almost
entirely, burning the leaves and combustible portion of the mould, and in
many places cracking and disintegrating the rock beneath. The rains of the
following autumn carried off much of the remaining soil, and the mountain-
side was nearly bare of wood for two or three years afterwards. At length a
new crop of trees sprang up and grew vigorously, and the mountain is now
thickly covered again. But the depth of mould and earth is too small to
allow the trees to reach maturity. When they attain to the diameter of about
six inches, they uniformly die, and this they will no doubt continue to do
until the decay of leaves and wood on the surface, and the decomposition of
the subjacent rock, shall have formed, perhaps hundreds of years hence, a
stratum of soil thick enough to support a full-grown forest. Under favorable
Page 461
conditions, however, as in the case of the fire of Miramichi, a burnt forest
renews itself rapidly and permanently.]
Aside from the destruction of the trees and the laying bare of the soil, and
consequently the freer admission of sun, rain, and air to the ground, the fire
of itself exerts an important influence on its texture and condition. It cracks
and sometimes even pulverizes the rocks and stones upon and near the
surface; [Footnote: In the burning over of a hill-forest in the Lower
Engadine, in September, 1865, the fire was so intense as to shatter and
calcine the rocks on the slope, and their fragments were precipitated into the
valley below.—Rivista Forestale del Regno d'Italia, Ottobre, 1865, p. 474.]
it consumes a portion of the half-decayed vegetable mould which served to
hold its mineral particles together and to retain the water of precipitation,
and thus loosens, pulverizes, and dries the earth; it destroys reptiles, insects,
and worms, with their eggs, and the seeds of trees and of smaller plants; it
supplies, in the ashes which it deposits on the surface, important elements
for the growth of a new forest clothing, as well as of the usual objects of
agricultural industry; and by the changes thus produced, it fits the ground
for the reception of a vegetation different in character from that which had
spontaneously covered it. These new conditions help to explain the natural
succession of forest crops, so generally observed in all woods cleared by
fire and then abandoned. There is no doubt, however, that other influences
contribute to the same result, because effects more or less analogous follow
when the trees are destroyed by other causes, as by high winds, by the
woodman's axe, and even by natural decay. [Footnote: The remarkable
mounds and other earthworks constructed in the valley of the Ohio and
elsewhere in the territory of the United States, by a people apparently more
advanced in culture than the modern Indian, were overgrown with a dense
clothing of forest when first discovered by the whites. But though the
ground where they were erected must have been occupied by a large
population for a considerable length of time, and therefore entirely cleared,
renews itself rapidly and permanently.]
Aside from the destruction of the trees and the laying bare of the soil, and
consequently the freer admission of sun, rain, and air to the ground, the fire
of itself exerts an important influence on its texture and condition. It cracks
and sometimes even pulverizes the rocks and stones upon and near the
surface; [Footnote: In the burning over of a hill-forest in the Lower
Engadine, in September, 1865, the fire was so intense as to shatter and
calcine the rocks on the slope, and their fragments were precipitated into the
valley below.—Rivista Forestale del Regno d'Italia, Ottobre, 1865, p. 474.]
it consumes a portion of the half-decayed vegetable mould which served to
hold its mineral particles together and to retain the water of precipitation,
and thus loosens, pulverizes, and dries the earth; it destroys reptiles, insects,
and worms, with their eggs, and the seeds of trees and of smaller plants; it
supplies, in the ashes which it deposits on the surface, important elements
for the growth of a new forest clothing, as well as of the usual objects of
agricultural industry; and by the changes thus produced, it fits the ground
for the reception of a vegetation different in character from that which had
spontaneously covered it. These new conditions help to explain the natural
succession of forest crops, so generally observed in all woods cleared by
fire and then abandoned. There is no doubt, however, that other influences
contribute to the same result, because effects more or less analogous follow
when the trees are destroyed by other causes, as by high winds, by the
woodman's axe, and even by natural decay. [Footnote: The remarkable
mounds and other earthworks constructed in the valley of the Ohio and
elsewhere in the territory of the United States, by a people apparently more
advanced in culture than the modern Indian, were overgrown with a dense
clothing of forest when first discovered by the whites. But though the
ground where they were erected must have been occupied by a large
population for a considerable length of time, and therefore entirely cleared,
Page 462
the trees which grew upon the ancient fortresses and the adjacent lands
were not distinguishable in species, or even in dimensions and character of
growth, from the neighboring forests, where the soil seemed never to have
been disturbed. This apparent exception to the law of change of crop in
natural forest growth was ingeniously explained by General Harrison's
suggestion, that the lapse of time since the era of the mound-builders were
so great as to have embraced several successive generations of trees, and
occasioned, by their rotation, a return to the original vegetation.
The successive changes in the spontaneous growth of the forest, as
proved by the character of a wood found in bogs, are such as to have
suggested the theory of a considerable change of the climate during the
human period. But this theory cannot be admitted upon the evidence in
question. In fact, the order of succession—for a rotation or alternation is
neither proved nor probable—may be made to move in opposite directions
in different countries with the same climate and at the same time. Thus in
Denmark and in Holland the spike-leaved firs have given place to the
broad-leaved beech, while in Northern Germany the process has been
reversed, and evergreens have supplanted the oaks and birches of deciduous
foliage. The principal determining cause seems to be the influence of light
upon the germination of the seeds and the growth of the young tree. In a
forest of firs, for instance, the distribution of the light and shade, to the
influence of which seeds and shoots are exposed, is by no means the same
as in a wood of beeches or of oaks, and hence the growth of different
species will be stimulated in the two forests.
When ground is laid bare both of trees and of vegetable mould, and left
to the action of unaided and unobstructed nature, she first propagates trees
which germinate and grow only under the influence of a full supply of light
and air, and then, in succession, other species, according to their ability to
bear the shade and their demand for more abundant nutriment. In Northern
were not distinguishable in species, or even in dimensions and character of
growth, from the neighboring forests, where the soil seemed never to have
been disturbed. This apparent exception to the law of change of crop in
natural forest growth was ingeniously explained by General Harrison's
suggestion, that the lapse of time since the era of the mound-builders were
so great as to have embraced several successive generations of trees, and
occasioned, by their rotation, a return to the original vegetation.
The successive changes in the spontaneous growth of the forest, as
proved by the character of a wood found in bogs, are such as to have
suggested the theory of a considerable change of the climate during the
human period. But this theory cannot be admitted upon the evidence in
question. In fact, the order of succession—for a rotation or alternation is
neither proved nor probable—may be made to move in opposite directions
in different countries with the same climate and at the same time. Thus in
Denmark and in Holland the spike-leaved firs have given place to the
broad-leaved beech, while in Northern Germany the process has been
reversed, and evergreens have supplanted the oaks and birches of deciduous
foliage. The principal determining cause seems to be the influence of light
upon the germination of the seeds and the growth of the young tree. In a
forest of firs, for instance, the distribution of the light and shade, to the
influence of which seeds and shoots are exposed, is by no means the same
as in a wood of beeches or of oaks, and hence the growth of different
species will be stimulated in the two forests.
When ground is laid bare both of trees and of vegetable mould, and left
to the action of unaided and unobstructed nature, she first propagates trees
which germinate and grow only under the influence of a full supply of light
and air, and then, in succession, other species, according to their ability to
bear the shade and their demand for more abundant nutriment. In Northern
Page 463
Europe the large, the white birch, the aspen, first appear; then follow the
maple, the alder, the ash, the fir; then the oak and the linden; and then the
beech. The trees called by these respective names in the United States are
not specifically the same as their European namesakes, nor are they always
even the equivalents of these latter, and therefore the order of succession in
America would not be precisely as indicated by the foregoing list, but, so
far as is known, it nevertheless very nearly corresponds to it.
It is thought important to encourage the growth of the beech in Denmark
and Northern Germany, because it upon the whole yields better returns than
other trees, and does not exhaust, but on the contrary enriches, the soil; for
by shedding its leaves it returns to it most of the nutriment it has drawn
from it, and at the same time furnishes a solvent which aids materially in
the decomposition of its mineral constituents.
maple, the alder, the ash, the fir; then the oak and the linden; and then the
beech. The trees called by these respective names in the United States are
not specifically the same as their European namesakes, nor are they always
even the equivalents of these latter, and therefore the order of succession in
America would not be precisely as indicated by the foregoing list, but, so
far as is known, it nevertheless very nearly corresponds to it.
It is thought important to encourage the growth of the beech in Denmark
and Northern Germany, because it upon the whole yields better returns than
other trees, and does not exhaust, but on the contrary enriches, the soil; for
by shedding its leaves it returns to it most of the nutriment it has drawn
from it, and at the same time furnishes a solvent which aids materially in
the decomposition of its mineral constituents.
Page 464
When the forest is left to itself, the order of succession is constant, and its
occasional inversion is always explicable by some human interference. It is
curious that the trees which require most light are content with the poorest
soils, and vice versa. The trees which first appear are also those which
propagate themselves farthest to the north. The birch, the larch, and the fir
bear a severer climate than the oak, the oak than the beech. "These
parallelisms," says Vaupell, "are very interesting, because, though they are
entirely independent of each other," they all prescribe the same order of
succession.—Bogens Indvandring, p. 42. See alo Berg, Das Verdrangen der
Laubralder im Nordlichen Deutschland, 1844. Heyer, Das Verhalten der
Waldbaume gegen Licht und Schatten, 1852. Staring, De Bodem van
Nederland, 1856, i., pp. 120-200. Vaupell, De Danske Skove, 1863. Knorr,
Studien uber die Buchen-Wirthschaft, 1863. A. Maury, Les Forets de la
Gaule, pp. 73, 74, 377, 384.]
Another evil, sometimes of serious magnitude, which attends the
operations of the lumberman, is the injury to the banks of rivers from the
practice of floating. I do not here allude to rafts, which, being under the
control of those who navigate them, may be so guided as to avoid damage
to the shore, but to masts, logs, and other pieces of timber singly entrusted
to the streams, to be conveyed by their currents to sawmill ponds, or to
convenient places for collecting them into rafts. The lumbermen usually
haul the timber to the banks of the rivers in the winter, and when the spring
floods swell the streams and break up the ice, they roll the logs into the
water, leaving them to float down to their destination. If the transporting
stream is too small to furnish a sufficient channel for this rude navigation, it
is sometimes dammed up, and the timber collected in the pond thus formed
above the dam. When the pond is full, a sluice is opened, or the dam is
blown up or otherwise suddenly broken, and the whole mass of lumber
above it is hurried down with the rolling flood. Both of these modes of
occasional inversion is always explicable by some human interference. It is
curious that the trees which require most light are content with the poorest
soils, and vice versa. The trees which first appear are also those which
propagate themselves farthest to the north. The birch, the larch, and the fir
bear a severer climate than the oak, the oak than the beech. "These
parallelisms," says Vaupell, "are very interesting, because, though they are
entirely independent of each other," they all prescribe the same order of
succession.—Bogens Indvandring, p. 42. See alo Berg, Das Verdrangen der
Laubralder im Nordlichen Deutschland, 1844. Heyer, Das Verhalten der
Waldbaume gegen Licht und Schatten, 1852. Staring, De Bodem van
Nederland, 1856, i., pp. 120-200. Vaupell, De Danske Skove, 1863. Knorr,
Studien uber die Buchen-Wirthschaft, 1863. A. Maury, Les Forets de la
Gaule, pp. 73, 74, 377, 384.]
Another evil, sometimes of serious magnitude, which attends the
operations of the lumberman, is the injury to the banks of rivers from the
practice of floating. I do not here allude to rafts, which, being under the
control of those who navigate them, may be so guided as to avoid damage
to the shore, but to masts, logs, and other pieces of timber singly entrusted
to the streams, to be conveyed by their currents to sawmill ponds, or to
convenient places for collecting them into rafts. The lumbermen usually
haul the timber to the banks of the rivers in the winter, and when the spring
floods swell the streams and break up the ice, they roll the logs into the
water, leaving them to float down to their destination. If the transporting
stream is too small to furnish a sufficient channel for this rude navigation, it
is sometimes dammed up, and the timber collected in the pond thus formed
above the dam. When the pond is full, a sluice is opened, or the dam is
blown up or otherwise suddenly broken, and the whole mass of lumber
above it is hurried down with the rolling flood. Both of these modes of
Page 465
proceeding expose the banks of the rivers employed as channels of flotation
to abrasion, [Footnote: Caimi states that "a single flotation in the Valtelline,
in 1830, caused damages appraised at $250,000."—Cenni sulla Importanza
e Coltura dei Boschi, p. 65.] and in some of the American States it has been
found necessary to protect, by special legislation, the lands through which
they flow from the serious injury sometimes received through the practices
I have described. [Footnote: Many physicists who have investigated the
laws of natural hydraulics maintain that, in consequence of direct
obstruction and frictional resistance to the flow of the water of rivers along
their banks, there is both an increased rapidity of current and an elevation of
the water in the middle of the channel, so that a river presents always a
convex surface. Others have thought that the acknowledged greater
swiftness of the central current must produce a depression in that part of the
stream. The lumbermen affirm that, while rivers are rising, the water is
highest in the middle of the channel, and tends to throw floating objects
shorewards; while they are falling, it is lowest in the middle, and floating
objects incline towards the centre. Logs, they say, rolled into the water
during the rise, are very apt to lodge on the banks, while those set afloat
during the falling of the waters keep in the current, and are carried without
hindrance to their destination, and this law, which has been a matter of
familiar observation among woodmen for generations, is now admitted as a
scientific truth.
Foresters and lumbermen, like sailors and other persons whose daily
occupations bring them into contact, and often into conflict, with great
natural forces, have many peculiar opinions, not to say superstitious. In one
of these categories we must rank the universal belief of lumbermen, that
with a given head of water, and in a given number of hours, a sawmill cuts
more lumber by night than by day. Having been personally interested in
several sawmills, been assured by them that their uniform experiences
established the fact that, other things being equal, the action of the
to abrasion, [Footnote: Caimi states that "a single flotation in the Valtelline,
in 1830, caused damages appraised at $250,000."—Cenni sulla Importanza
e Coltura dei Boschi, p. 65.] and in some of the American States it has been
found necessary to protect, by special legislation, the lands through which
they flow from the serious injury sometimes received through the practices
I have described. [Footnote: Many physicists who have investigated the
laws of natural hydraulics maintain that, in consequence of direct
obstruction and frictional resistance to the flow of the water of rivers along
their banks, there is both an increased rapidity of current and an elevation of
the water in the middle of the channel, so that a river presents always a
convex surface. Others have thought that the acknowledged greater
swiftness of the central current must produce a depression in that part of the
stream. The lumbermen affirm that, while rivers are rising, the water is
highest in the middle of the channel, and tends to throw floating objects
shorewards; while they are falling, it is lowest in the middle, and floating
objects incline towards the centre. Logs, they say, rolled into the water
during the rise, are very apt to lodge on the banks, while those set afloat
during the falling of the waters keep in the current, and are carried without
hindrance to their destination, and this law, which has been a matter of
familiar observation among woodmen for generations, is now admitted as a
scientific truth.
Foresters and lumbermen, like sailors and other persons whose daily
occupations bring them into contact, and often into conflict, with great
natural forces, have many peculiar opinions, not to say superstitious. In one
of these categories we must rank the universal belief of lumbermen, that
with a given head of water, and in a given number of hours, a sawmill cuts
more lumber by night than by day. Having been personally interested in
several sawmills, been assured by them that their uniform experiences
established the fact that, other things being equal, the action of the
Page 466
machinery of sawmills is more rapid by night than by day. I am sorry—
perhaps I ought to be ashamed—to say that my skepticism has been too
strong to allow me to avail myself of my ooportunites of testing this
question by passing a night, watch in hand, counting the strokes of a
millisaw. More unprejudiced, and, I must add, very intelligent and credible
persons have informed me that they have done so, and found the report of
the sawyers abundantly confirmed. A land surveyor, who was also an
experienced lumberman, sawyer, and machinist, a good mathematician, and
an accurate observer, has repeatedly told me that he had very often "timed"
sawmills, and before the difference in favor of night-work above thirty per
cent. Sed quaere.]
Restoration of the Forest.
In most countries of Europe—and I fear in many parts of the United
States—the woods are already so nearly extirpated, that the mere protection
of those which now exist is by no means an adequate security against a
great increase of the evils which have already resulted from the diminution
of them. Besides this, experience has shown that where the destruction of
the woods has been carried beyond a certain point, no coercive legislation
can absolutely secure the permanence of the remainder, especially if it is
held by private hands. The creation of new forests, therefore, is generally
recognized, wherever the subject has received the attention it merits, as an
indispensable measure of sound public economy. Enlightened individuals in
some European states, the Governments in others, have made extensive
plantations, and France, particularly, has now set herself energetically at
work to restore the woods in her southern provinces, and thereby to prevent
the utter depopulation and waste with which that once fertile soil and genial
climate are threatened.
perhaps I ought to be ashamed—to say that my skepticism has been too
strong to allow me to avail myself of my ooportunites of testing this
question by passing a night, watch in hand, counting the strokes of a
millisaw. More unprejudiced, and, I must add, very intelligent and credible
persons have informed me that they have done so, and found the report of
the sawyers abundantly confirmed. A land surveyor, who was also an
experienced lumberman, sawyer, and machinist, a good mathematician, and
an accurate observer, has repeatedly told me that he had very often "timed"
sawmills, and before the difference in favor of night-work above thirty per
cent. Sed quaere.]
Restoration of the Forest.
In most countries of Europe—and I fear in many parts of the United
States—the woods are already so nearly extirpated, that the mere protection
of those which now exist is by no means an adequate security against a
great increase of the evils which have already resulted from the diminution
of them. Besides this, experience has shown that where the destruction of
the woods has been carried beyond a certain point, no coercive legislation
can absolutely secure the permanence of the remainder, especially if it is
held by private hands. The creation of new forests, therefore, is generally
recognized, wherever the subject has received the attention it merits, as an
indispensable measure of sound public economy. Enlightened individuals in
some European states, the Governments in others, have made extensive
plantations, and France, particularly, has now set herself energetically at
work to restore the woods in her southern provinces, and thereby to prevent
the utter depopulation and waste with which that once fertile soil and genial
climate are threatened.
Page 467
The objects of the restoration of the forest are as multifarious as the
motives that have led to its destruction, and as the evils which that
destruction has occasioned. It is hoped that the replanting of the mountain
slopes, and of bleak and infertile plains, will diminish the frequency and
violence of river inundations, prevent the formation of new torrents and
check the violence of those already existing, mitigate the extremes of
atmospheric temperature, humidity, and precipitation, restore dried-up
springs, rivulets, and sources of irrigation, shelter the fields from chilling
and from parching winds, arrest the spread of miasmatic effluvia, and,
finally, furnish a self-renewing and inexhaustible supply of a material
indispensable to so many purposes of domestic comfort, and to the
successful exercise of every art of peace, every destructive energy of war.
[Footnote: The preservation of the woods on the former eastern frontier of
France, as a kind of natural abattis, was recognized by the Government of
that country as an important measure of military defence, though there have
been conflicting opinions on the subject.]
The Economy of the Forest.
The legislation of European states upon sylviculture, and the practice of
that art, divide themselves into two great branches—the preservation of
existing forests, and the creation of new. Although there are in Europe many
forests neither planted nor regularly trained by man, yet from the long
operation of causes already set forth, what is understood in America and
other new countries by the "primitive forest," no longer exists in the
territories which were the seats of ancient civilization and empire, except
upon a small scale, and in remote and almost inaccessible glens quite out of
the reach of ordinary observation. The oldest European woods are indeed
native, that is, sprung from self-sown seed, or from the roots of trees which
have been felled for human purposes; but their growth has been controlled,
in a variety of ways, by man and by domestic animals, and they almost
motives that have led to its destruction, and as the evils which that
destruction has occasioned. It is hoped that the replanting of the mountain
slopes, and of bleak and infertile plains, will diminish the frequency and
violence of river inundations, prevent the formation of new torrents and
check the violence of those already existing, mitigate the extremes of
atmospheric temperature, humidity, and precipitation, restore dried-up
springs, rivulets, and sources of irrigation, shelter the fields from chilling
and from parching winds, arrest the spread of miasmatic effluvia, and,
finally, furnish a self-renewing and inexhaustible supply of a material
indispensable to so many purposes of domestic comfort, and to the
successful exercise of every art of peace, every destructive energy of war.
[Footnote: The preservation of the woods on the former eastern frontier of
France, as a kind of natural abattis, was recognized by the Government of
that country as an important measure of military defence, though there have
been conflicting opinions on the subject.]
The Economy of the Forest.
The legislation of European states upon sylviculture, and the practice of
that art, divide themselves into two great branches—the preservation of
existing forests, and the creation of new. Although there are in Europe many
forests neither planted nor regularly trained by man, yet from the long
operation of causes already set forth, what is understood in America and
other new countries by the "primitive forest," no longer exists in the
territories which were the seats of ancient civilization and empire, except
upon a small scale, and in remote and almost inaccessible glens quite out of
the reach of ordinary observation. The oldest European woods are indeed
native, that is, sprung from self-sown seed, or from the roots of trees which
have been felled for human purposes; but their growth has been controlled,
in a variety of ways, by man and by domestic animals, and they almost
Page 468
uniformly present more or less of an artificial character and arrangement.
Both they and planted forests—which, though certainly not few, are of
comparatively recent date in Europe—demand, as well for protection as for
promotion of growth, a treatment different in some respects from that which
would be suited to the character and wants of the virgin wood.
On this latter branch of the subject, the management of the primitive
wood, experience and observation have not yet collected a sufficient stock
of facts to serve for the construction of a complete system of this
department of sylviculture; but the government of the forest as it exists in
France—the different zones and climates of which country present many
points of analogy with those of the United States and of some of the British
colonies—has been carefully studied, and several manuals of practice have
been prepared for the foresters of that empire. I believe the Cours
Elementaire de Culture des Bois cree a l'Ecole Forestiere de Nancy, par M.
Lorentz, complete et public par A. Parade, with a supplement under the title
of Cours d'Amenagement des Forets, par Henri Nanquette, has been
generally considered the best of these. The Etudes sur l'Economie
Forestiere, par Jules Clave, which I have often quoted, presents a great
number of interesting views on this subject, but it is not designed as a
practical guide, and it does not profess to be sufficiently specific in its
details to serve that purpose. [Footnote: Among more recent manuals may
be mentioned: in French, Les Etudes de Maitre Pierre, Paris, 1864, 12mo;
Bazelaire, Traite de Roboisement, 2d edition. Paris 1864; Paston,
L'Amenagemend des Forets, Paris, 1867; in English, Gregor, Arboriculture,
Edinburgh, 1868: in Italian, Siemoni 's very valuable Manuale teorico-
pratico d'Arte Forestale, 2d ediz., Firenze, 1872; the excellent work of
Cerini, Dei Vantaggi di Societe, por l'Impianto e Conservazione dei Boschi,
Milano, 1844, 8vo; and the prize essay of Meguscher, Memoria sui Boschi,
etc., 2d edizione, Milano, 1859, 8vo. Another very important treatise of the
uses of the forest, though not a manual of sylviculture, is Schleiden, Fur
Both they and planted forests—which, though certainly not few, are of
comparatively recent date in Europe—demand, as well for protection as for
promotion of growth, a treatment different in some respects from that which
would be suited to the character and wants of the virgin wood.
On this latter branch of the subject, the management of the primitive
wood, experience and observation have not yet collected a sufficient stock
of facts to serve for the construction of a complete system of this
department of sylviculture; but the government of the forest as it exists in
France—the different zones and climates of which country present many
points of analogy with those of the United States and of some of the British
colonies—has been carefully studied, and several manuals of practice have
been prepared for the foresters of that empire. I believe the Cours
Elementaire de Culture des Bois cree a l'Ecole Forestiere de Nancy, par M.
Lorentz, complete et public par A. Parade, with a supplement under the title
of Cours d'Amenagement des Forets, par Henri Nanquette, has been
generally considered the best of these. The Etudes sur l'Economie
Forestiere, par Jules Clave, which I have often quoted, presents a great
number of interesting views on this subject, but it is not designed as a
practical guide, and it does not profess to be sufficiently specific in its
details to serve that purpose. [Footnote: Among more recent manuals may
be mentioned: in French, Les Etudes de Maitre Pierre, Paris, 1864, 12mo;
Bazelaire, Traite de Roboisement, 2d edition. Paris 1864; Paston,
L'Amenagemend des Forets, Paris, 1867; in English, Gregor, Arboriculture,
Edinburgh, 1868: in Italian, Siemoni 's very valuable Manuale teorico-
pratico d'Arte Forestale, 2d ediz., Firenze, 1872; the excellent work of
Cerini, Dei Vantaggi di Societe, por l'Impianto e Conservazione dei Boschi,
Milano, 1844, 8vo; and the prize essay of Meguscher, Memoria sui Boschi,
etc., 2d edizione, Milano, 1859, 8vo. Another very important treatise of the
uses of the forest, though not a manual of sylviculture, is Schleiden, Fur
Page 469
Baum und Wald, Leipzig, 1870.]Notwithstanding the difference of
conditions between the aboriginal and the trained forest, the judicious
observer who aims at the preservation of the former will reap much
instruction from the treatises I have cited, and I believe he will be
convinced that the sooner a natural wood is brought into the state of an
artificially regulated one, the better it is for all the multiplied interests
which depend on the wise administration of this branch of public economy.
One consideration bearing on this subject has received less attention than
it merits, because most persons interested in such questions have not
opportunities for the comparison I refer to. I mean the great general
superiority of cultivated timber to that of strictly spontaneous growth. I say
GENERAL superiority, because there are exceptions to the rule. The white
pine, Pinus strobus, for instance, and other trees of similar character and
uses, require, for their perfect growth and best ligneous texture, a density of
forest vegetation around them, which protects them from too much agitation
by wind, and from the persistence of the lateral branches which fill the
wood with knots. A pine which has grown under those conditions possesses
a tall, straight stem, admirably fitted for masts and spars, and, at the same
time, its wood is almost wholly free from knots, is regular in annular
structure, soft and uniform in texture, and, consequently, superior to almost
all other timber for joinery. If, while a large pine is spared, the broad-leaved
or other smaller trees around it are felled, the swaying of the tree from the
action of the wind mechanically produces separations between the layers of
annual growth, and greatly diminishes the value of the timber. The same
defect is often observed in pines which, from some accident of growth,
have much overtopped their fellows in the virgin forest.
The white pine, growing in the fields, or in open glades in the woods, is
totally different from the true forest-tree, both in general aspect and in
quality of wood. Its stem is much shorter, its top less tapering, its foliage
conditions between the aboriginal and the trained forest, the judicious
observer who aims at the preservation of the former will reap much
instruction from the treatises I have cited, and I believe he will be
convinced that the sooner a natural wood is brought into the state of an
artificially regulated one, the better it is for all the multiplied interests
which depend on the wise administration of this branch of public economy.
One consideration bearing on this subject has received less attention than
it merits, because most persons interested in such questions have not
opportunities for the comparison I refer to. I mean the great general
superiority of cultivated timber to that of strictly spontaneous growth. I say
GENERAL superiority, because there are exceptions to the rule. The white
pine, Pinus strobus, for instance, and other trees of similar character and
uses, require, for their perfect growth and best ligneous texture, a density of
forest vegetation around them, which protects them from too much agitation
by wind, and from the persistence of the lateral branches which fill the
wood with knots. A pine which has grown under those conditions possesses
a tall, straight stem, admirably fitted for masts and spars, and, at the same
time, its wood is almost wholly free from knots, is regular in annular
structure, soft and uniform in texture, and, consequently, superior to almost
all other timber for joinery. If, while a large pine is spared, the broad-leaved
or other smaller trees around it are felled, the swaying of the tree from the
action of the wind mechanically produces separations between the layers of
annual growth, and greatly diminishes the value of the timber. The same
defect is often observed in pines which, from some accident of growth,
have much overtopped their fellows in the virgin forest.
The white pine, growing in the fields, or in open glades in the woods, is
totally different from the true forest-tree, both in general aspect and in
quality of wood. Its stem is much shorter, its top less tapering, its foliage
Page 470
denser and more inclined to gather into tufts, its branches more numerous
and of larger diameter, its wood shows much more distinctly the divisions
of annual growth, is of coarser grain, harder and more difficult to work into
mitre-joints. Intermixed with the most valuable pines in the American
forests, are met many trees of the character I have just described. The
lumbermen call them "saplings," and generally regard them as different in
species from the true white pine, but botanists are unable to establish a
distinction between them, and as they agree in almost all respects with trees
grown in the open grounds from known white-pine seedlings, I believe their
peculiar character is due to unfavorable circumstances in their early growth.
The pine, then, is an exception to the general rule as to the inferiority of the
forest to the open-ground tree. The pasture oak and pasture beech, on the
contrary, are well known to produce far better timber than those grown in
the woods, and there are few trees to which the remark is not equally
applicable. [Footnote: It is often laid down as a universal law, that the wood
of trees of slow vegetation is superior to that of quick growth. This is one of
those commonplaces by which men love to shield themselves from the
labor of painstaking observation. It has, in fact, so many exceptions, that it
may be doubted in whether it is in any sense true. Most of the cedars are
slow of growth; but while the timber of some of them is firm and durable,
that of others is light, brittle, and perishable. The hemlock-spruce is slower
of growth than the pines, but its wood is of very little value. The pasture
oak and beech show a breadth of grain—and, of course, an annual
increment—twice as great as trees of the same species grown in the woods;
and the American locust, Robinia pseudacacia, the wood of which is of
extreme toughness and durability, is, of all trees indigenous to North-
eastern America, by far the most rapid in growth. Some of the species of the
Australian Eucalyptus furnish wood of remarkable strength and durability,
and yet the eucalyptus is surpassed by no known tree in rapidity of growth.
and of larger diameter, its wood shows much more distinctly the divisions
of annual growth, is of coarser grain, harder and more difficult to work into
mitre-joints. Intermixed with the most valuable pines in the American
forests, are met many trees of the character I have just described. The
lumbermen call them "saplings," and generally regard them as different in
species from the true white pine, but botanists are unable to establish a
distinction between them, and as they agree in almost all respects with trees
grown in the open grounds from known white-pine seedlings, I believe their
peculiar character is due to unfavorable circumstances in their early growth.
The pine, then, is an exception to the general rule as to the inferiority of the
forest to the open-ground tree. The pasture oak and pasture beech, on the
contrary, are well known to produce far better timber than those grown in
the woods, and there are few trees to which the remark is not equally
applicable. [Footnote: It is often laid down as a universal law, that the wood
of trees of slow vegetation is superior to that of quick growth. This is one of
those commonplaces by which men love to shield themselves from the
labor of painstaking observation. It has, in fact, so many exceptions, that it
may be doubted in whether it is in any sense true. Most of the cedars are
slow of growth; but while the timber of some of them is firm and durable,
that of others is light, brittle, and perishable. The hemlock-spruce is slower
of growth than the pines, but its wood is of very little value. The pasture
oak and beech show a breadth of grain—and, of course, an annual
increment—twice as great as trees of the same species grown in the woods;
and the American locust, Robinia pseudacacia, the wood of which is of
extreme toughness and durability, is, of all trees indigenous to North-
eastern America, by far the most rapid in growth. Some of the species of the
Australian Eucalyptus furnish wood of remarkable strength and durability,
and yet the eucalyptus is surpassed by no known tree in rapidity of growth.
Page 471
As an illustration of the mutual interdependence of the mechanic arts, I
may mention that in Italy, where stone, brick, and plaster are almost the
only materials used in architecture, and where the "hollow ware" kitchen
implements are of copper or of clay, the ordinary tools for working wood
are of a very inferior description, and the locust timber is found too hard for
their temper. At the same time the work of the Italian stipettai, or cabinet-
makers, and carvers in wood, who take pains to provide themselves with
tools of better metal, is wholly unsurpassed in finish and in accuracy of
adjustment as well as in taste. When a small quantity of mahogany was
brought to England, early in the last century, the cabinet-makers were
unable to use it, from the defective temper of their tools, until the demand
for furniture from the new wood compelled them to improve the quality of
their implements. In America, the cheapness of wood long made it the
preferable material for almost all purposes to which it could by any
possibility be applied. The mechanical cutlery and artisans' tools of the
United States are of admirable temper, finish, and convenience, and no
wood is too hard, or otherwise too refractory, to be wrought with great
facility, both by hand-tools and by the multitude of ingenious machines
which the Americans have invented for this purpose.]
Another advantage of the artificially regulated forest is, that it admits of
such grading of the ground as to favor the retention or discharge of water at
will, while the facilities it affords for selecting and duly proportioning, as
well as properly spacing, and in felling and removing, from time to time,
the trees which compose it, are too obvious to require to be more than
hinted at. In conducting these operations, we must have a diligent eye to the
requirements of nature, and must remember that a wood is not an arbitrary
assemblage of trees to be selected and disposed according to the caprice of
its owner. "A forest," says Clave, "is not, as is often supposed, a simple
collection of trees succeeding each other in long perspective, without bond
of union, and capable of isolation from each other; it is, on the contrary, a
may mention that in Italy, where stone, brick, and plaster are almost the
only materials used in architecture, and where the "hollow ware" kitchen
implements are of copper or of clay, the ordinary tools for working wood
are of a very inferior description, and the locust timber is found too hard for
their temper. At the same time the work of the Italian stipettai, or cabinet-
makers, and carvers in wood, who take pains to provide themselves with
tools of better metal, is wholly unsurpassed in finish and in accuracy of
adjustment as well as in taste. When a small quantity of mahogany was
brought to England, early in the last century, the cabinet-makers were
unable to use it, from the defective temper of their tools, until the demand
for furniture from the new wood compelled them to improve the quality of
their implements. In America, the cheapness of wood long made it the
preferable material for almost all purposes to which it could by any
possibility be applied. The mechanical cutlery and artisans' tools of the
United States are of admirable temper, finish, and convenience, and no
wood is too hard, or otherwise too refractory, to be wrought with great
facility, both by hand-tools and by the multitude of ingenious machines
which the Americans have invented for this purpose.]
Another advantage of the artificially regulated forest is, that it admits of
such grading of the ground as to favor the retention or discharge of water at
will, while the facilities it affords for selecting and duly proportioning, as
well as properly spacing, and in felling and removing, from time to time,
the trees which compose it, are too obvious to require to be more than
hinted at. In conducting these operations, we must have a diligent eye to the
requirements of nature, and must remember that a wood is not an arbitrary
assemblage of trees to be selected and disposed according to the caprice of
its owner. "A forest," says Clave, "is not, as is often supposed, a simple
collection of trees succeeding each other in long perspective, without bond
of union, and capable of isolation from each other; it is, on the contrary, a
Page 472
whole, the different parts of which are interdependent upon each other, and
it constitutes, so to speak, a true individuality. Every forest has a special
character, determined by the form of the surface it grows upon, the kinds of
trees that compose it, and the manner in which they are grouped." The art,
or, as the Continental foresters rather ambitiously call it, the science of
sylviculture has been so little pursued in England and America, that its
nomenclature has not been introduced into the English vocabulary, and it
would not be possible to describe its processes with technical propriety of
language, without occasionally borrowing a word from the forest literature
of France and Germany. A full discussion of the methods of sylviculture
would, indeed, be out of place in a work like the present, but the want of
conveniently accessible means of information on the subject, in the United
States, will justify me in presenting it with somewhat more of detail than
would otherwise be pertinent.
The two best known methods of treating already existing forests are those
distinguished as the TAILLIS, copse or coppice treatment, [Footnote:
COPSE, or COPPICE, from the French COUPER, to cut, means properly a
wood, the trees of which are cut at certain periods of immature growth, and
allowed to shoot up again from the roots; but it has come to signify, very
commonly, a young wood, grove, or thicket, without reference to its origin,
or to the character of a forest crop.] and the FUTAIE, for which I find no
English equivalent, but which may not inappropriately be called the FULL-
GROWTH system. A TAILLIS, copse, or coppice, is a wood composed of
shoots from the roots of trees previously cut for fuel and timber. The shoots
are thinned out from time to time, and finally cut, either after a fixed
number of years, or after the young trees have attained to certain
dimensions, their roots being then left to send out a new progeny as before.
This is the cheapest method of management, and therefore the best
whenever the price of labor and of capital bears a high proportion to that of
land and of timber; but it is essentially a wasteful economy. [Footnote: "In
it constitutes, so to speak, a true individuality. Every forest has a special
character, determined by the form of the surface it grows upon, the kinds of
trees that compose it, and the manner in which they are grouped." The art,
or, as the Continental foresters rather ambitiously call it, the science of
sylviculture has been so little pursued in England and America, that its
nomenclature has not been introduced into the English vocabulary, and it
would not be possible to describe its processes with technical propriety of
language, without occasionally borrowing a word from the forest literature
of France and Germany. A full discussion of the methods of sylviculture
would, indeed, be out of place in a work like the present, but the want of
conveniently accessible means of information on the subject, in the United
States, will justify me in presenting it with somewhat more of detail than
would otherwise be pertinent.
The two best known methods of treating already existing forests are those
distinguished as the TAILLIS, copse or coppice treatment, [Footnote:
COPSE, or COPPICE, from the French COUPER, to cut, means properly a
wood, the trees of which are cut at certain periods of immature growth, and
allowed to shoot up again from the roots; but it has come to signify, very
commonly, a young wood, grove, or thicket, without reference to its origin,
or to the character of a forest crop.] and the FUTAIE, for which I find no
English equivalent, but which may not inappropriately be called the FULL-
GROWTH system. A TAILLIS, copse, or coppice, is a wood composed of
shoots from the roots of trees previously cut for fuel and timber. The shoots
are thinned out from time to time, and finally cut, either after a fixed
number of years, or after the young trees have attained to certain
dimensions, their roots being then left to send out a new progeny as before.
This is the cheapest method of management, and therefore the best
whenever the price of labor and of capital bears a high proportion to that of
land and of timber; but it is essentially a wasteful economy. [Footnote: "In
Page 473
America," says Clave (p. 124, 125), "where there is a vast extent of land
almost without pecuniary value, but where labor is dear and the rate of
interest high, it is profitable to till a large surface at the least possible cost.
EXTENSIVE cultivation is there the most advantageous. In England,
France, and Germany, where every corner of soil is occupied, and the least
bit of ground is sold at a high price, but where labor and capital are
comparatively cheap is wisest to employ INTENSIVE cultivation. … All
the efforts of the cultivator ought to be directed to the obtaining of a given
result with the least sacrifice, and there is equally a loss to the
commonwealth if the application of improved agricultural processes be
neglected where they are advantageous, or if they be employed where they
are not required. … In this point of view, sylviculture must follow the same
laws as agriculture, and, like it, be modified according to the economical
conditions of different states. In countries abounding in good forests, and
thinly peopled, elementary and cheap methods must be pursued; in civilized
regions, where a dense population requires that the soil shall be made to
produce all it can yield, the regular artificial forest, with all the processes
that science teaches, should be cultivated. It would be absurd to apply to the
endless woods of Brazil and of Canada the method of the Spessart by
"double stages," but not less so in our country, where every yard of ground
has a high value, to leave to nature the task of propagating trees, and to
content ourselves with cutting, every twenty or twenty-five years, the
meagre growths that chance may have produced."] If the woodland is, in the
first place, completely cut over as is found most convenient in practice, the
young shoots have neither the shade nor the protection from wind so
important to forest growth, and their progress is comparatively slow, while
at the same time, the thick clumps they form choke the seedlings that may
have sprouted near them. [Footnote: In ordinary coppices, there are few or
no seedlings, because the young shoots are cut before they are old enough
to mature fertile seed, and this is one of the strongest objections to the
almost without pecuniary value, but where labor is dear and the rate of
interest high, it is profitable to till a large surface at the least possible cost.
EXTENSIVE cultivation is there the most advantageous. In England,
France, and Germany, where every corner of soil is occupied, and the least
bit of ground is sold at a high price, but where labor and capital are
comparatively cheap is wisest to employ INTENSIVE cultivation. … All
the efforts of the cultivator ought to be directed to the obtaining of a given
result with the least sacrifice, and there is equally a loss to the
commonwealth if the application of improved agricultural processes be
neglected where they are advantageous, or if they be employed where they
are not required. … In this point of view, sylviculture must follow the same
laws as agriculture, and, like it, be modified according to the economical
conditions of different states. In countries abounding in good forests, and
thinly peopled, elementary and cheap methods must be pursued; in civilized
regions, where a dense population requires that the soil shall be made to
produce all it can yield, the regular artificial forest, with all the processes
that science teaches, should be cultivated. It would be absurd to apply to the
endless woods of Brazil and of Canada the method of the Spessart by
"double stages," but not less so in our country, where every yard of ground
has a high value, to leave to nature the task of propagating trees, and to
content ourselves with cutting, every twenty or twenty-five years, the
meagre growths that chance may have produced."] If the woodland is, in the
first place, completely cut over as is found most convenient in practice, the
young shoots have neither the shade nor the protection from wind so
important to forest growth, and their progress is comparatively slow, while
at the same time, the thick clumps they form choke the seedlings that may
have sprouted near them. [Footnote: In ordinary coppices, there are few or
no seedlings, because the young shoots are cut before they are old enough
to mature fertile seed, and this is one of the strongest objections to the
Page 474
system.] The evergreens, once cut do not shoot up again, [Footnote: It was
not long ago stated, upon the evidence of the Government foresters of
Greece, and of the queen's gardener, that a large wood has been discovered
in Arcadia, consisting of a fir which has the property of sending up both
vertical and lateral shoots from the stump of felled trees and forming a new
crown. It was at first supposed that this forest grew only on the
"mountains," of which the hero of About's most amusing story, Le Roi des
Montagnes, was "king;" but stumps, with the shoots attached, have been
sent to Germany, and recognized by able botanists as true natural products,
and the fact must now be considered as established. Daubeny refers to
Theophrastus as ascribing this faculty of reproduction to the 'Elate [word in
greek] or fir, but he does not cite chapter and verse, and I have not been
able to find the passage. The same writer mentions a case where an entire
forest of the common fir in France had been renewed in this way.—Trees
and Shrubs of the Ancients, 1865, pp. 27-28. The American Northern pitch
possesses the same power in a certain degree.
According to Charles Martins, the cedar of Mount Atlas—which, if not
identical with the cedar of Lebanon, is closely allied to it—possesses the
same power.—Revue des Deux Mondes, July 15, 1864, p. 315.] and the
mixed character of the forest—in many respects an important advantage, if
not an indispensable condition of growth—is lost; [Footnote: Natural
forests are rarely, if ever, composed of trees of a single species, and
experience has shown that oaks and other broad-leaved trees, planted as
artificial woods, require to be mixed, or associated with others of different
habits.
In the forest of Fontainebleau, "oaks, mingled with beeches in due
proportion," says Clave, "may arrive at the age of five or six hundred years
in full vigor, and attain dimensions which I have never seen surpassed;
when, however, they are wholly unmixed with other trees, they begin to
not long ago stated, upon the evidence of the Government foresters of
Greece, and of the queen's gardener, that a large wood has been discovered
in Arcadia, consisting of a fir which has the property of sending up both
vertical and lateral shoots from the stump of felled trees and forming a new
crown. It was at first supposed that this forest grew only on the
"mountains," of which the hero of About's most amusing story, Le Roi des
Montagnes, was "king;" but stumps, with the shoots attached, have been
sent to Germany, and recognized by able botanists as true natural products,
and the fact must now be considered as established. Daubeny refers to
Theophrastus as ascribing this faculty of reproduction to the 'Elate [word in
greek] or fir, but he does not cite chapter and verse, and I have not been
able to find the passage. The same writer mentions a case where an entire
forest of the common fir in France had been renewed in this way.—Trees
and Shrubs of the Ancients, 1865, pp. 27-28. The American Northern pitch
possesses the same power in a certain degree.
According to Charles Martins, the cedar of Mount Atlas—which, if not
identical with the cedar of Lebanon, is closely allied to it—possesses the
same power.—Revue des Deux Mondes, July 15, 1864, p. 315.] and the
mixed character of the forest—in many respects an important advantage, if
not an indispensable condition of growth—is lost; [Footnote: Natural
forests are rarely, if ever, composed of trees of a single species, and
experience has shown that oaks and other broad-leaved trees, planted as
artificial woods, require to be mixed, or associated with others of different
habits.
In the forest of Fontainebleau, "oaks, mingled with beeches in due
proportion," says Clave, "may arrive at the age of five or six hundred years
in full vigor, and attain dimensions which I have never seen surpassed;
when, however, they are wholly unmixed with other trees, they begin to
Page 475
decay and die at the top, at the age of forty or fifty years, like men, old
before their time, weary of the world, and longing only to quit it. This has
been observed in most of the oak plantations of which I have spoken, and
they have not been able to attain to full growth. When the vegetation was
perceived to languish, they were cut, in the hope that this operation would
restore their vigor, and that the new shoots would succeed better than the
original trees; and, in fact, they seemed to be recovering for the first few
years. But the shoots were soon attacked by the same decay, and the
operation had to be renewed at shorter and shorter intervals, until at last it
was found necessary to treat as coppices plantations originally designed for
the full-growth system. Nor was this all: the soil, periodically bared by
these cuttings, became impoverished, and less and less suited to the growth
of the oak. … It was then proposed to introduce the pine and plant with it
the vacancies and glades.
"… By this means, the forest was saved from the ruin which threatened
it, and now more than 10,000 acres of pines, from fifteen to thirty years old
are disseminated at various points, sometimes intermixed with broad-leaved
trees, sometimes forming groves by themselves"—Revue des Deux
Mondes, Mai, 1863, pp. 153, 154.] and besides this, large wood of any
species cannot be grown in this method because trees which shoot from
decaying stumps and their dying roots, become hollow or otherwise
unsound before they acquire their full dimensions. A more fatal objection
still, is, that the roots of trees will not bear more than two or three, or at
most four cuttings of their shoots before their vitality is exhausted, and the
wood can then be restored only by replanting entirely.
The period of cutting coppices varies in Europe from fifteen to forty
years, according to soil, species, and rapidity of growth. In the futaie, or
full-growth system, the trees are allowed to stand as long as they continue
in healthy and vigorous growth. This is a shorter period than would be at
before their time, weary of the world, and longing only to quit it. This has
been observed in most of the oak plantations of which I have spoken, and
they have not been able to attain to full growth. When the vegetation was
perceived to languish, they were cut, in the hope that this operation would
restore their vigor, and that the new shoots would succeed better than the
original trees; and, in fact, they seemed to be recovering for the first few
years. But the shoots were soon attacked by the same decay, and the
operation had to be renewed at shorter and shorter intervals, until at last it
was found necessary to treat as coppices plantations originally designed for
the full-growth system. Nor was this all: the soil, periodically bared by
these cuttings, became impoverished, and less and less suited to the growth
of the oak. … It was then proposed to introduce the pine and plant with it
the vacancies and glades.
"… By this means, the forest was saved from the ruin which threatened
it, and now more than 10,000 acres of pines, from fifteen to thirty years old
are disseminated at various points, sometimes intermixed with broad-leaved
trees, sometimes forming groves by themselves"—Revue des Deux
Mondes, Mai, 1863, pp. 153, 154.] and besides this, large wood of any
species cannot be grown in this method because trees which shoot from
decaying stumps and their dying roots, become hollow or otherwise
unsound before they acquire their full dimensions. A more fatal objection
still, is, that the roots of trees will not bear more than two or three, or at
most four cuttings of their shoots before their vitality is exhausted, and the
wood can then be restored only by replanting entirely.
The period of cutting coppices varies in Europe from fifteen to forty
years, according to soil, species, and rapidity of growth. In the futaie, or
full-growth system, the trees are allowed to stand as long as they continue
in healthy and vigorous growth. This is a shorter period than would be at
Page 476
first supposed, when we consider the advanced age and great dimensions to
which, under favorable circumstances, many forest-trees attain in temperate
climates. But, as every observing person familiar with the forest is aware,
these are exceptional cases, just as are instances of great longevity or of
gigantic stature among men. Able vegetable physiologists have maintained
that the tree, like most fish and reptiles, has no natural limit of life or of
growth, and that the only reason why our oaks and our pines do not reach
the age of twenty centuries and the height of a hundred fathoms, is, that in
the multitude of accidents to which they are exposed, the chances of their
attaining to such a length of years and to such dimensions of growth are
millions to one against them. But another explanation of this fact is
possible. In trees affected by no discoverable external cause of death, decay
begins at the topmost branches, which seem to wither and die for want of
nutriment. The mysterious force by which the sap is carried from the roots
to the utmost twigs, cannot be conceived to be unlimited in power, and it is
probable that it differs in different species, so that while it may suffice to
raise the fluid to the height of five hundred feet in the eucalyptus, it may not
be able to carry it beyond one hundred and fifty in the oak. The limit may
be different, too, in different trees of the same species, not from defective
organization in those of inferior growth, but from more or less favorable
conditions of soil, nourishment, and exposure. Whenever a tree attains to
the limit beyond which its circulating fluids cannot rise, we may suppose
that decay begins, and death follows from want of nutrition at the
extremities, and from the same causes which bring about the same results in
animals of limited size—such, for example, as the interruption of functions
essential to life, in consequence of the clogging up of ducts by matter
assimilable in the stage of growth, but no longer so when increment has
ceased. In the natural woods we observe that, though, among the myriads of
trees which grow upon a square mile, there are several vegetable giants, yet
the great majority of them begin to decay long before they have attained
which, under favorable circumstances, many forest-trees attain in temperate
climates. But, as every observing person familiar with the forest is aware,
these are exceptional cases, just as are instances of great longevity or of
gigantic stature among men. Able vegetable physiologists have maintained
that the tree, like most fish and reptiles, has no natural limit of life or of
growth, and that the only reason why our oaks and our pines do not reach
the age of twenty centuries and the height of a hundred fathoms, is, that in
the multitude of accidents to which they are exposed, the chances of their
attaining to such a length of years and to such dimensions of growth are
millions to one against them. But another explanation of this fact is
possible. In trees affected by no discoverable external cause of death, decay
begins at the topmost branches, which seem to wither and die for want of
nutriment. The mysterious force by which the sap is carried from the roots
to the utmost twigs, cannot be conceived to be unlimited in power, and it is
probable that it differs in different species, so that while it may suffice to
raise the fluid to the height of five hundred feet in the eucalyptus, it may not
be able to carry it beyond one hundred and fifty in the oak. The limit may
be different, too, in different trees of the same species, not from defective
organization in those of inferior growth, but from more or less favorable
conditions of soil, nourishment, and exposure. Whenever a tree attains to
the limit beyond which its circulating fluids cannot rise, we may suppose
that decay begins, and death follows from want of nutrition at the
extremities, and from the same causes which bring about the same results in
animals of limited size—such, for example, as the interruption of functions
essential to life, in consequence of the clogging up of ducts by matter
assimilable in the stage of growth, but no longer so when increment has
ceased. In the natural woods we observe that, though, among the myriads of
trees which grow upon a square mile, there are several vegetable giants, yet
the great majority of them begin to decay long before they have attained
Page 477
their maximum of stature, and this seems to be still more emphatically true
of the artificial forest. In France, according to Clave, "oaks, in a suitable
soil, may stand, without exhibiting any sign of decay, for two or three
hundred years; the pines hardly exceed one hundred and twenty, and the
soft or white woods [bois blancs], in wet soils, languish, and die before
reaching the fiftieth year." [Footnote: Etudes Forestieres, p. 80.] These ages
are certainly below the average of those of American forest-trees, and are
greatly exceeded in very numerous well-attested instances of isolated trees
in Europe.
The former mode of treating the futaie, called the garden system, was to
cut the trees individually as they arrived at maturity, but, in the best
regulated forests, this practice has been abandoned for the German method,
which embraces not only the securing of the largest immediate profit, but
the replanting of the forest, and the care of the young growth. This is
effected in the case of a forest, whether natural or artificial, which is to be
subjected to regular management, by three operations. The first of these
consists in felling about one-third of the trees, in such way as to leave
convenient spaces for the growth of seedlings. The remaining two-thirds are
relied upon to replant the vacancies, by natural sowing, which they seldom
or never fail to do. The seedlings are watched, are thinned out when too
dense, and the ill-formed and sickly, as well as those of species of inferior
value, and the shrubs and thorns which might otherwise choke or too
closely shade them, are pulled up. When they have attained sufficient
strength and development of foliage to require, or at least to bear, more light
and air, the second step is taken, by removing a suitable proportion of the
old trees which had been spared at the first cutting; and when, finally, the
younger trees are hardened enough to bear frost and sun without other
protection than that which they mutually give to each other, the remainder
of the original forest is felled, and the wood now consists wholly of young
and vigorous trees. This result is obtained after about twenty years. At
of the artificial forest. In France, according to Clave, "oaks, in a suitable
soil, may stand, without exhibiting any sign of decay, for two or three
hundred years; the pines hardly exceed one hundred and twenty, and the
soft or white woods [bois blancs], in wet soils, languish, and die before
reaching the fiftieth year." [Footnote: Etudes Forestieres, p. 80.] These ages
are certainly below the average of those of American forest-trees, and are
greatly exceeded in very numerous well-attested instances of isolated trees
in Europe.
The former mode of treating the futaie, called the garden system, was to
cut the trees individually as they arrived at maturity, but, in the best
regulated forests, this practice has been abandoned for the German method,
which embraces not only the securing of the largest immediate profit, but
the replanting of the forest, and the care of the young growth. This is
effected in the case of a forest, whether natural or artificial, which is to be
subjected to regular management, by three operations. The first of these
consists in felling about one-third of the trees, in such way as to leave
convenient spaces for the growth of seedlings. The remaining two-thirds are
relied upon to replant the vacancies, by natural sowing, which they seldom
or never fail to do. The seedlings are watched, are thinned out when too
dense, and the ill-formed and sickly, as well as those of species of inferior
value, and the shrubs and thorns which might otherwise choke or too
closely shade them, are pulled up. When they have attained sufficient
strength and development of foliage to require, or at least to bear, more light
and air, the second step is taken, by removing a suitable proportion of the
old trees which had been spared at the first cutting; and when, finally, the
younger trees are hardened enough to bear frost and sun without other
protection than that which they mutually give to each other, the remainder
of the original forest is felled, and the wood now consists wholly of young
and vigorous trees. This result is obtained after about twenty years. At
Page 478
convenient periods, the unhealthy stocks and those injured by wind or other
accidents are removed, and in some instances the growth of the remainder is
promoted by irrigation or by fertilizing applications. [Footnote: The
grounds which it is most important to clothe with wood as a conservative
influence, and which, also, can best be spared from agricultural use, are
steep hillsides. But the performance of all the offices of the forester to the
tree—seeding, planting, thinning, trimming, and finally felling and
removing for consumption—is more laborious upon a rapid declivity than
on a level soil, and at the same time it is difficult to apply irrigation or
manures to trees so situated. Experience has shown that there in great
advantage in terracing the face of a hill before planting it, both as
preventing the wash of the earth by checking the flow of water down its
slope, and as presenting a surface favorable for irrigation, as well as for
manuring and cultivating the tree. But even without so expensive a process,
very important results have been obtained by simply ditching declivities.
"In order to hasten the growth of wood on the flanks of a mountain, Mr.
Eugene Chevandier divided the slope into zones forty or fifty feet wide, by
horizontal ditches closed at both ends, and thereby obtained, from firs of
different ages, shoots double the dimensions of those which grew on a dry
soil of the same character, where the water was allowed to run off without
obstruction."—Dumont, Des Travaux Publics, etc., pp. 94-96. The ditches
were about two feet and a half deep, and three feet and a half wide, and they
cost about forty francs the hectare, or three dollars the acre. This
extraordinary growth was produced wholly by the retention of the rain-
water in the ditches, whence it filtered through the whole soil and supplied
moisture to the roots of the trees. It may be doubted whether in a climate
cold enough to freeze the entire contents of the ditches in winter, it would
not be expedient to draw off the water in the autumn, as the presence of so
large a quantity of ice in the soil might prove injurious to trees too young
and small to shelter the ground effectually against frost.
accidents are removed, and in some instances the growth of the remainder is
promoted by irrigation or by fertilizing applications. [Footnote: The
grounds which it is most important to clothe with wood as a conservative
influence, and which, also, can best be spared from agricultural use, are
steep hillsides. But the performance of all the offices of the forester to the
tree—seeding, planting, thinning, trimming, and finally felling and
removing for consumption—is more laborious upon a rapid declivity than
on a level soil, and at the same time it is difficult to apply irrigation or
manures to trees so situated. Experience has shown that there in great
advantage in terracing the face of a hill before planting it, both as
preventing the wash of the earth by checking the flow of water down its
slope, and as presenting a surface favorable for irrigation, as well as for
manuring and cultivating the tree. But even without so expensive a process,
very important results have been obtained by simply ditching declivities.
"In order to hasten the growth of wood on the flanks of a mountain, Mr.
Eugene Chevandier divided the slope into zones forty or fifty feet wide, by
horizontal ditches closed at both ends, and thereby obtained, from firs of
different ages, shoots double the dimensions of those which grew on a dry
soil of the same character, where the water was allowed to run off without
obstruction."—Dumont, Des Travaux Publics, etc., pp. 94-96. The ditches
were about two feet and a half deep, and three feet and a half wide, and they
cost about forty francs the hectare, or three dollars the acre. This
extraordinary growth was produced wholly by the retention of the rain-
water in the ditches, whence it filtered through the whole soil and supplied
moisture to the roots of the trees. It may be doubted whether in a climate
cold enough to freeze the entire contents of the ditches in winter, it would
not be expedient to draw off the water in the autumn, as the presence of so
large a quantity of ice in the soil might prove injurious to trees too young
and small to shelter the ground effectually against frost.
Page 479
Chevandier computes that, if the annual growth of the pine in the marshy
and too humid soil of the Vosges be represented by one, it will equal two in
ordinary dry ground, four or five on slopes so ditched or graded as to retain
the water flowing upon them from roads or steep declivities, and six where
the earth is kept sufficiently moist by infiltration from running brooks.—
Comptes Rendus a l'Academie des Sciences, t. xix., Juillet, Dec., 1844, p.
167. The effect of accidental irrigation in well shown in the growth of the
trees planted along the canals of irrigation which traverse the fields in many
parts of Italy. They nourish most luxuriantly, in spite of continual lopping,
and yield a very important contribution to the stock of fuel for domestic use
while trees, situated so far from canals as to be out of the reach of
infiltration from them, are of much slower growth, under circumstances
otherwise equally favorable. In other experiments of Chevandier, under
better conditions, the yield of wood was increased, by judicious irrigation,
in the ratio of seven to one, the profits in that of twelve to one. At the
Exposition of 1855, Chambrelent exhibited young trees, which, in four
years from the seed, had grown to the height of sixteen and twenty feet, and
the circumference of ten and twelve inches. Chevandier experimented with
various manures, and found that some of them might be profitably applied
to young but not to old trees, the quantity required in the latter case being
too great. Wood-ashes and the refuse of soda factories are particularly
recommended. See, on the manuring of trees, Chevandier, Recherches sur
l'emploi de divers amendements, etc., Paris, 1852, and Koderle, Grundsatze
der Kunstlichen Dungung im Forstculturwesen. Wien, 1865.
I have seen an extraordinary growth produced in fir-trees by the
application of soapsuds; in a young and sickly cherry-tree, by heaping the
chips and dust from a marble-quarry, to the height of two or three feet, over
the roots and around the stem; and cases have come to my knowledge
where like results followed the planting of vines and trees in holes half
filled with fragments of plaster-castings, and mortar from old buildings.
and too humid soil of the Vosges be represented by one, it will equal two in
ordinary dry ground, four or five on slopes so ditched or graded as to retain
the water flowing upon them from roads or steep declivities, and six where
the earth is kept sufficiently moist by infiltration from running brooks.—
Comptes Rendus a l'Academie des Sciences, t. xix., Juillet, Dec., 1844, p.
167. The effect of accidental irrigation in well shown in the growth of the
trees planted along the canals of irrigation which traverse the fields in many
parts of Italy. They nourish most luxuriantly, in spite of continual lopping,
and yield a very important contribution to the stock of fuel for domestic use
while trees, situated so far from canals as to be out of the reach of
infiltration from them, are of much slower growth, under circumstances
otherwise equally favorable. In other experiments of Chevandier, under
better conditions, the yield of wood was increased, by judicious irrigation,
in the ratio of seven to one, the profits in that of twelve to one. At the
Exposition of 1855, Chambrelent exhibited young trees, which, in four
years from the seed, had grown to the height of sixteen and twenty feet, and
the circumference of ten and twelve inches. Chevandier experimented with
various manures, and found that some of them might be profitably applied
to young but not to old trees, the quantity required in the latter case being
too great. Wood-ashes and the refuse of soda factories are particularly
recommended. See, on the manuring of trees, Chevandier, Recherches sur
l'emploi de divers amendements, etc., Paris, 1852, and Koderle, Grundsatze
der Kunstlichen Dungung im Forstculturwesen. Wien, 1865.
I have seen an extraordinary growth produced in fir-trees by the
application of soapsuds; in a young and sickly cherry-tree, by heaping the
chips and dust from a marble-quarry, to the height of two or three feet, over
the roots and around the stem; and cases have come to my knowledge
where like results followed the planting of vines and trees in holes half
filled with fragments of plaster-castings, and mortar from old buildings.
Page 480
Chevandier's experiments in the irrigation of the forest would not have been
a "new thing under the sun" to wise King Solomon, for that monarch saya:
"I made me pools of water, to water therewith, the wood that bringeth forth
trees." Eccles. ii. 6.]
When the forest is approaching maturity, the original processes already
described are repeated; and as, in different parts of an extensive forest, they
would take place at different times in different zones, it would afford
indefinitely an annual crop of small wood, fuel, and timber.
The duties of the forester do not end here, for it sometimes happens that
the glades left by felling the older trees are not sufficiently seeded, or that
the species, or essences, as the French oddly call them, are not duly
proportioned in the new crop. In this case, seed must be artificially sown, or
young trees planted in the vacancies. Besides this, all trees, whether grown
for fruit, for fuel, or for timber, require more or less training in order to
yield the best returns. The experiments of the Vicomte de Courval in
sylviculture throw much light on this subject, and show, in a most
interesting way, the importance of pruning forest-trees. The principal
feature of De Courval's very successful method is a systematical mode of
trimming which compels the tree to develop the stem, by reducing the
lateral ramification. Beginning with young trees, the buds are rubbed off
from the stems, and superfluous lateral shoots are pruned down to the trunk.
When large trees are taken in hand, branches which can be spared, and
whose removal is necessary to obtain a proper length of stem, are very
smoothly cut off quite close to the trunk, and the exposed surface is
IMMEDIATELY brushed over with mineral-coal tar. When thus treated, it
is said that the healing of the wound is perfect, and without any decay of the
tree. Trees trained by De Courval's method, which is now universally
approved and much practised in France, rapidly attained a great height.
They grow with remarkable straightness of stem and of grain, and their
a "new thing under the sun" to wise King Solomon, for that monarch saya:
"I made me pools of water, to water therewith, the wood that bringeth forth
trees." Eccles. ii. 6.]
When the forest is approaching maturity, the original processes already
described are repeated; and as, in different parts of an extensive forest, they
would take place at different times in different zones, it would afford
indefinitely an annual crop of small wood, fuel, and timber.
The duties of the forester do not end here, for it sometimes happens that
the glades left by felling the older trees are not sufficiently seeded, or that
the species, or essences, as the French oddly call them, are not duly
proportioned in the new crop. In this case, seed must be artificially sown, or
young trees planted in the vacancies. Besides this, all trees, whether grown
for fruit, for fuel, or for timber, require more or less training in order to
yield the best returns. The experiments of the Vicomte de Courval in
sylviculture throw much light on this subject, and show, in a most
interesting way, the importance of pruning forest-trees. The principal
feature of De Courval's very successful method is a systematical mode of
trimming which compels the tree to develop the stem, by reducing the
lateral ramification. Beginning with young trees, the buds are rubbed off
from the stems, and superfluous lateral shoots are pruned down to the trunk.
When large trees are taken in hand, branches which can be spared, and
whose removal is necessary to obtain a proper length of stem, are very
smoothly cut off quite close to the trunk, and the exposed surface is
IMMEDIATELY brushed over with mineral-coal tar. When thus treated, it
is said that the healing of the wound is perfect, and without any decay of the
tree. Trees trained by De Courval's method, which is now universally
approved and much practised in France, rapidly attained a great height.
They grow with remarkable straightness of stem and of grain, and their
Page 481
timber commands the highest price. [Footnote: See De Courval, Taille et
conduite des Arbres forestieres et autres arbres de grande dimension. Paris,
1861.
The most important part of Viscount de Courval's system will be found in
L'Elagage des Arbres, par le Comte A. Des Cars, an admirable little treatise,
of which numerous editions, at the price of one franc, have been printed
since the first, of 1864, and which ought to be translated and published
without delay in the United States.]
A system of plantation, specially though not exclusively suited to very
moist soils, recommended by Duhamel a hundred years ago, has been
revived in Germany, within about twenty years, with much success. It is
called hill-planting, and consists in placing the young tree upright on the
greensward with its roots properly spread out, and then covering the roots
and supporting the trunk by thick sods cut so as to form a circular hillock
around it. [Footnote: See Manteuffel, L'Art de Planter, traduit par Stumper.
Paris, 1868.] By this method it is alleged trees can be grown
advantageously both in dry ground and on humid soils, where they would
not strike root if planted in holes after the usual mauner. If there is any truth
in the theory of a desiccating action in evergreen trees, plantations of this
sort might have a value as drainers of lands not easily laid dry by other
processes. There is much ground on the great prairies of the West, where
experiments with this method of planting are strongly to be recommended.
It is common in Europe to permit the removal of the fallen leaves and
fragments of bark and branches with which the forest-soil is covered, and
sometimes the cutting of the lower twigs of evergreens. The leaves and
twigs are principally used as litter for cattle, and finally as manure, the bark
and wind-fallen branches as fuel. By long usage, sometimes by express
grant, this privilege has become a vested right of the population in the
conduite des Arbres forestieres et autres arbres de grande dimension. Paris,
1861.
The most important part of Viscount de Courval's system will be found in
L'Elagage des Arbres, par le Comte A. Des Cars, an admirable little treatise,
of which numerous editions, at the price of one franc, have been printed
since the first, of 1864, and which ought to be translated and published
without delay in the United States.]
A system of plantation, specially though not exclusively suited to very
moist soils, recommended by Duhamel a hundred years ago, has been
revived in Germany, within about twenty years, with much success. It is
called hill-planting, and consists in placing the young tree upright on the
greensward with its roots properly spread out, and then covering the roots
and supporting the trunk by thick sods cut so as to form a circular hillock
around it. [Footnote: See Manteuffel, L'Art de Planter, traduit par Stumper.
Paris, 1868.] By this method it is alleged trees can be grown
advantageously both in dry ground and on humid soils, where they would
not strike root if planted in holes after the usual mauner. If there is any truth
in the theory of a desiccating action in evergreen trees, plantations of this
sort might have a value as drainers of lands not easily laid dry by other
processes. There is much ground on the great prairies of the West, where
experiments with this method of planting are strongly to be recommended.
It is common in Europe to permit the removal of the fallen leaves and
fragments of bark and branches with which the forest-soil is covered, and
sometimes the cutting of the lower twigs of evergreens. The leaves and
twigs are principally used as litter for cattle, and finally as manure, the bark
and wind-fallen branches as fuel. By long usage, sometimes by express
grant, this privilege has become a vested right of the population in the
Page 482
neighborhood of many public and even large private forests; but it is
generally regarded as a serious evil. To remove the leaves and fallen twigs
is to withdraw much of the pabulum upon which the tree was destined to
feed. The small branches and leaves are the parts of the tree which yield the
largest proportion of ashes on combustion, and of course they supply a great
amount of nutriment for the young shoots. "A cubic foot of twigs," says
Vaupell, "yields four times as much ashes as a cubic foot of stem wood. …
For every hundred weight of dried leaves carried off from a beech forest,
we sacrifice a hundred and sixty cubic feet of wood. The leaves and the
mosses are a substitute, not only for manure, but for ploughing. The
carbonic acid given out by decaying leaves, when taken up by water, serves
to dissolve the mineral constituents of the soil, and is particularly active in
disintegrating feldspar and the clay derived from its decomposition. … The
leaves belong to the soil. Without them it cannot preserve its fertility, and
cannot furnish nutriment to the beech. The trees languish, produce seed
incapable of germination, and the spontaneous self-sowing, which is an
indispensable element in the best systems of sylviculture, fails altogether in
the bared and impoverished soil." [Footnote: Vaupell, Bogens Indvandring i
de Danske Skove, pp. 29, 46. Vaupell further observes, on the page last
quoted: "The removal of leaves is injurious to the forest, not only because it
retards the growth of trees, but still more because it disqualifies the soil for
the production of particular species. When the beech languishes, and the
development of its branches is less vigorous and its crown less spreading, it
becomes unable to resist the encroachments of the fir. This latter tree thrives
in an inferior soil, and being no longer stifled by the thick foliage of the
beech, it spreads gradually through the wood, while the beech retreats
before it and finally perishes."
Schleiden confirms the opinion of Vaupell, and adds many important
observations on this subject.—Fur Baum und Wald, pp. 64, 65.]
generally regarded as a serious evil. To remove the leaves and fallen twigs
is to withdraw much of the pabulum upon which the tree was destined to
feed. The small branches and leaves are the parts of the tree which yield the
largest proportion of ashes on combustion, and of course they supply a great
amount of nutriment for the young shoots. "A cubic foot of twigs," says
Vaupell, "yields four times as much ashes as a cubic foot of stem wood. …
For every hundred weight of dried leaves carried off from a beech forest,
we sacrifice a hundred and sixty cubic feet of wood. The leaves and the
mosses are a substitute, not only for manure, but for ploughing. The
carbonic acid given out by decaying leaves, when taken up by water, serves
to dissolve the mineral constituents of the soil, and is particularly active in
disintegrating feldspar and the clay derived from its decomposition. … The
leaves belong to the soil. Without them it cannot preserve its fertility, and
cannot furnish nutriment to the beech. The trees languish, produce seed
incapable of germination, and the spontaneous self-sowing, which is an
indispensable element in the best systems of sylviculture, fails altogether in
the bared and impoverished soil." [Footnote: Vaupell, Bogens Indvandring i
de Danske Skove, pp. 29, 46. Vaupell further observes, on the page last
quoted: "The removal of leaves is injurious to the forest, not only because it
retards the growth of trees, but still more because it disqualifies the soil for
the production of particular species. When the beech languishes, and the
development of its branches is less vigorous and its crown less spreading, it
becomes unable to resist the encroachments of the fir. This latter tree thrives
in an inferior soil, and being no longer stifled by the thick foliage of the
beech, it spreads gradually through the wood, while the beech retreats
before it and finally perishes."
Schleiden confirms the opinion of Vaupell, and adds many important
observations on this subject.—Fur Baum und Wald, pp. 64, 65.]
Page 483
Besides these evils, the removal of the leaves deprives the soil of much
of that spongy character which gives it such immense value as a reservoir of
moisture and a regulator of the flow of springs; and, finally, it exposes the
surface-roots to the drying influence of sun and wind, to accidental
mechanical injury from the tread of animals or men, and, in cold climates,
to the destructive effects of frost.
Protection against Wild Animals.
It is often necessary to take measures for the protection of young trees
against the rabbit, the mole, and other rodent quadrupeds, and of older ones
against the damage done by the larvae of insects hatched upon the surface
or in the tissues of the bark, or even in the wood itself. The much greater
liability of the artificial than of the natural forest to injury from this cause is
perhaps the only point in which the superiority of the former to the latter is
not as marked as that of any domesticated vegetable to its wild
representative. But the better quality of the wood and the much more rapid
growth of the trained and regulated forest are abundant compensations for
the loss thus occasioned, and the progress of entomological science will,
perhaps, suggest new methods of preventing the ravages of insects. Thus
far, however, the collection and destruction ofthe eggs, by simple but
expensive means, has proved the most effectual remedy. [Footnote: I have
remarked elsewhere that most insects which deposit and hatch their eggs in
the wood of the natural forest confine themselves to dead trees. Not only is
this the fact, but it is also true that many of the borers attack only freshly-
cut timber. Their season of labor is a short one, and unless the tree is cut
during this period, it is safe from them. In summer you may hear them
plying their augers in the wood of a young pine with soft, green bark, as
you sit upon its trunk, within a week after it has been felled, but the
windfalls of the winter lie uninjured by the worm and even undecayed for
of that spongy character which gives it such immense value as a reservoir of
moisture and a regulator of the flow of springs; and, finally, it exposes the
surface-roots to the drying influence of sun and wind, to accidental
mechanical injury from the tread of animals or men, and, in cold climates,
to the destructive effects of frost.
Protection against Wild Animals.
It is often necessary to take measures for the protection of young trees
against the rabbit, the mole, and other rodent quadrupeds, and of older ones
against the damage done by the larvae of insects hatched upon the surface
or in the tissues of the bark, or even in the wood itself. The much greater
liability of the artificial than of the natural forest to injury from this cause is
perhaps the only point in which the superiority of the former to the latter is
not as marked as that of any domesticated vegetable to its wild
representative. But the better quality of the wood and the much more rapid
growth of the trained and regulated forest are abundant compensations for
the loss thus occasioned, and the progress of entomological science will,
perhaps, suggest new methods of preventing the ravages of insects. Thus
far, however, the collection and destruction ofthe eggs, by simple but
expensive means, has proved the most effectual remedy. [Footnote: I have
remarked elsewhere that most insects which deposit and hatch their eggs in
the wood of the natural forest confine themselves to dead trees. Not only is
this the fact, but it is also true that many of the borers attack only freshly-
cut timber. Their season of labor is a short one, and unless the tree is cut
during this period, it is safe from them. In summer you may hear them
plying their augers in the wood of a young pine with soft, green bark, as
you sit upon its trunk, within a week after it has been felled, but the
windfalls of the winter lie uninjured by the worm and even undecayed for
Page 484
centuries. In the pine woods of New England, after the regular lumberman
has removed the standing trees, these old trunks are hauled out from the
mosses and leaves which half cover them, and often furnish excellent
timber. The slow decay of such timber in the woods, it may be remarked,
furnishes another proof of the uniformity of temperature and humidity in
the forest, for the trunk of a tree lying on grass or ploughland, and of course
exposed to all the alternations of climate, hardly resists complete
decomposition for a generation. The forests of Europe exhibit similar facts.
Wessely, in a description of the primitive wood of Neuwald in Lower
Austria, says that the windfalls required from 150 to 200 years for entire
decay.—Die Oesterreichischen Alpenlander und ihre Forste, p. 312.
The comparative immunity of the American native forests from attacks
by insects is perhaps in some degree due to the fact that the European
destructive tribes have not yet found their way across the ocean, and that
our native species are less injurious to living trees. On the European
lignivorous insects, see Siemoni, Manuale d'Arte Forestale, 2d edizione, pp.
369-379.]
Exclusion of Domestic Quadrupeds.
But probably the most important of all rules for the government of the
forest, whether natural or artificial, is that which prescribes the absolute
exclusion of all domestic quadrupeds, except swine, from every wood
which is not destined to be cleared. No growth of young trees is possible
where horned cattle, sheep, or goats, or even horses, are permitted to
pasture at any season of the year, though they are doubtless most destructive
when trees are in leaf. [Footnote: Although the economy of the forest has
received little attention in the United States, no lover of American nature
can have failed to observe a marked difference between a native wood from
which cattle are excluded and one where they are permitted to browse. A
has removed the standing trees, these old trunks are hauled out from the
mosses and leaves which half cover them, and often furnish excellent
timber. The slow decay of such timber in the woods, it may be remarked,
furnishes another proof of the uniformity of temperature and humidity in
the forest, for the trunk of a tree lying on grass or ploughland, and of course
exposed to all the alternations of climate, hardly resists complete
decomposition for a generation. The forests of Europe exhibit similar facts.
Wessely, in a description of the primitive wood of Neuwald in Lower
Austria, says that the windfalls required from 150 to 200 years for entire
decay.—Die Oesterreichischen Alpenlander und ihre Forste, p. 312.
The comparative immunity of the American native forests from attacks
by insects is perhaps in some degree due to the fact that the European
destructive tribes have not yet found their way across the ocean, and that
our native species are less injurious to living trees. On the European
lignivorous insects, see Siemoni, Manuale d'Arte Forestale, 2d edizione, pp.
369-379.]
Exclusion of Domestic Quadrupeds.
But probably the most important of all rules for the government of the
forest, whether natural or artificial, is that which prescribes the absolute
exclusion of all domestic quadrupeds, except swine, from every wood
which is not destined to be cleared. No growth of young trees is possible
where horned cattle, sheep, or goats, or even horses, are permitted to
pasture at any season of the year, though they are doubtless most destructive
when trees are in leaf. [Footnote: Although the economy of the forest has
received little attention in the United States, no lover of American nature
can have failed to observe a marked difference between a native wood from
which cattle are excluded and one where they are permitted to browse. A
Page 485
few seasons suffice for the total extirpation of the "underbrush," including
the young trees on which alone the reproduction of the forest depends, and
all the branches of those of larger growth which hang within reach of the
cattle are stripped of their buds and leaves, and soon wither and fall off.
These effects are observable at a great distance, and a wood-pasture is
recognized, almost as far as it can be seen, by the regularity with which its
lower foliage terminates at what Ruskin somewhere calls the "cattle-line."
This always runs parallel to the surface of the ground, and is determined by
the height to which domestic quadrupeds can reach to feed upon the leaves.
In describing a visit to the grand-ducal farm of San Rossore near Pisa,
where a large herd of camels is kept, Chateauvieux says: "In passing
through a wood of evergreen oaks, I observed that all the twigs and foliage
of the trees were clipped up to the height of about twelve feet above the
ground, without leaving a single spray below that level. I was informed that
the browsing of the camels had trimmed the trees as high as they could
reach." F. Lullin De Chateuvieux, Lettres sur l'Italie, p. 118.
Browsing animals, and most of all the goat, are considered by foresters as
more injurious to the growth of young trees, and, therefore, to the
reproduction of the forest, than almost any other destructive cause.
According to Beatson's Saint Helena, introductory chapter, and Darwin's
Journal of Researches in Geology and Natural History, pp. 582, 583, it was
the goats which destroyed the beautiful forests that, three hundred and fifty
years ago, covered a continuous surface of not less than two thousand acres
in the interior of the island [of St. Helena], not to mention scattered groups
of trees. Darwin observes: "During our stay at Valparaiso, I was most
positively assured that sandal-wood formerly grew in abundance on the
island of Juan Fernandez, but that this tree had now become entirely extinct
there, having been extirpated by the goats which early navigators had
introduced. The neighboring islands, to which goats have not been carried,
still abound in sandal-wood."
the young trees on which alone the reproduction of the forest depends, and
all the branches of those of larger growth which hang within reach of the
cattle are stripped of their buds and leaves, and soon wither and fall off.
These effects are observable at a great distance, and a wood-pasture is
recognized, almost as far as it can be seen, by the regularity with which its
lower foliage terminates at what Ruskin somewhere calls the "cattle-line."
This always runs parallel to the surface of the ground, and is determined by
the height to which domestic quadrupeds can reach to feed upon the leaves.
In describing a visit to the grand-ducal farm of San Rossore near Pisa,
where a large herd of camels is kept, Chateauvieux says: "In passing
through a wood of evergreen oaks, I observed that all the twigs and foliage
of the trees were clipped up to the height of about twelve feet above the
ground, without leaving a single spray below that level. I was informed that
the browsing of the camels had trimmed the trees as high as they could
reach." F. Lullin De Chateuvieux, Lettres sur l'Italie, p. 118.
Browsing animals, and most of all the goat, are considered by foresters as
more injurious to the growth of young trees, and, therefore, to the
reproduction of the forest, than almost any other destructive cause.
According to Beatson's Saint Helena, introductory chapter, and Darwin's
Journal of Researches in Geology and Natural History, pp. 582, 583, it was
the goats which destroyed the beautiful forests that, three hundred and fifty
years ago, covered a continuous surface of not less than two thousand acres
in the interior of the island [of St. Helena], not to mention scattered groups
of trees. Darwin observes: "During our stay at Valparaiso, I was most
positively assured that sandal-wood formerly grew in abundance on the
island of Juan Fernandez, but that this tree had now become entirely extinct
there, having been extirpated by the goats which early navigators had
introduced. The neighboring islands, to which goats have not been carried,
still abound in sandal-wood."
Page 486
In the winter, the deer tribe, especially the great American moose-deer,
subsists much on the buds and young sprouts of trees; yet—though from the
destruction of the wolves or from some not easily explained cause, these
latter animals have recently multiplied so rapidly in some parts of North
America, that, not long since, four hundred of them are said to have been
killed, in one season, on a territory in Maine not comprising more than one
hundred and fifty square miles—the wild browsing quadrupeds are rarely, if
ever, numerous enough in regions uninhabited by man to produce any
sensible effect on the condition of the forest. A reason why they are less
injurious than the goat to young trees may be that they resort to this
nutriment only in the winter, when the grasses and shrubs are leafless or
covered with snow, whereas the goat feeds upon buds and young shoots
principally in the season of growth. However this may be, the natural law of
consumption and supply keeps the forest growth, and the wild animals
which live on its products, in such a state of equilibrium as to insure the
indefinite continuance of both, and the perpetuity of neither is endangered
until man interferes and destroys the balance.
When, however, deer are bred and protected in parks, they multiply like
domestic cattle, and become equally injurious to trees. "A few years ago,"
says Clave, "there were not less than two thousand deer of different ages in
the forest of Fontainebleau. For want of grass, they are driven to the trees,
and they do not spare them … It is calculated that the browsing of these
animals, and the consequent retardation of the growth of the wood,
diminishes the annual product of the forest to the amount of two hundred
thousand cubic feet per year, … and besides this, the trees thus mutilated
are soon exhausted and die. The deer attack the pines, too, tearing off the
bark in long strips, or rubbing theie heads against them when shedding their
horns; and sometimes, in groves of more than a hundred hectares, not one
pine is found uninjured by them."—Revue des Deux Mondes, Mai, 1863, p.
157.
subsists much on the buds and young sprouts of trees; yet—though from the
destruction of the wolves or from some not easily explained cause, these
latter animals have recently multiplied so rapidly in some parts of North
America, that, not long since, four hundred of them are said to have been
killed, in one season, on a territory in Maine not comprising more than one
hundred and fifty square miles—the wild browsing quadrupeds are rarely, if
ever, numerous enough in regions uninhabited by man to produce any
sensible effect on the condition of the forest. A reason why they are less
injurious than the goat to young trees may be that they resort to this
nutriment only in the winter, when the grasses and shrubs are leafless or
covered with snow, whereas the goat feeds upon buds and young shoots
principally in the season of growth. However this may be, the natural law of
consumption and supply keeps the forest growth, and the wild animals
which live on its products, in such a state of equilibrium as to insure the
indefinite continuance of both, and the perpetuity of neither is endangered
until man interferes and destroys the balance.
When, however, deer are bred and protected in parks, they multiply like
domestic cattle, and become equally injurious to trees. "A few years ago,"
says Clave, "there were not less than two thousand deer of different ages in
the forest of Fontainebleau. For want of grass, they are driven to the trees,
and they do not spare them … It is calculated that the browsing of these
animals, and the consequent retardation of the growth of the wood,
diminishes the annual product of the forest to the amount of two hundred
thousand cubic feet per year, … and besides this, the trees thus mutilated
are soon exhausted and die. The deer attack the pines, too, tearing off the
bark in long strips, or rubbing theie heads against them when shedding their
horns; and sometimes, in groves of more than a hundred hectares, not one
pine is found uninjured by them."—Revue des Deux Mondes, Mai, 1863, p.
157.
Page 487
Vaupell, though agreeing with other writers as to the injury done to the
forest by most domestic animals and by half-tamed deer—which he
illustrates in an interesting way in his posthumous work, The Danish Woods
—thinks, nonetheless, that at the season when the mast is falling, swine are
rather useful than otherwise to forests of beech and oak, by treading into the
ground and thus sowing beechnuts and acorns, and by destroying moles and
mice.—De Danake Skore, p. 12. Meguschor is of the same opinion, and
adds that swine destroy injurious insects and their larvae.—Memoria, etc.,
p. 233.
Beckstein computes that a park of 2,500 acres, containing 250 acres of
marsh, 250 of fields and meadows, and the remaining 2,000 of wood, mny
keep 364 deer of different species, 47 wild boars, 200 hares, 100 rabbits,
and an indefinite number of pheasants. These animals would require, in
winter, 123,000 pounds of hay, and 22,000 pounds of potatoes, besides what
they would pick up themselves. The natural forest most thickly peopled
with wild animals would not, in temperate climates, contain, upon the
average, one-tenth of these numbers to the same extent of surface.]
These animals browse upon the terminal buds and the tender branches,
thereby stunting, if they do not kill, the young trees, and depriving them of
all beauty and vigor of growth.
Forest Fires.
The difficulty of protecting the woods against accidental or incendiary
fires is one of the most discouraging circumstances attending the
preservation of natural and the plantation of artificial forests. [Footnote:
The disappearance of the forests of ancient Gaul and of mediaeval France
has been ascribed by some writers as much to accidental fires as to the
felling of the trees. All the treatises on sylviculture are full of narratives of
forest by most domestic animals and by half-tamed deer—which he
illustrates in an interesting way in his posthumous work, The Danish Woods
—thinks, nonetheless, that at the season when the mast is falling, swine are
rather useful than otherwise to forests of beech and oak, by treading into the
ground and thus sowing beechnuts and acorns, and by destroying moles and
mice.—De Danake Skore, p. 12. Meguschor is of the same opinion, and
adds that swine destroy injurious insects and their larvae.—Memoria, etc.,
p. 233.
Beckstein computes that a park of 2,500 acres, containing 250 acres of
marsh, 250 of fields and meadows, and the remaining 2,000 of wood, mny
keep 364 deer of different species, 47 wild boars, 200 hares, 100 rabbits,
and an indefinite number of pheasants. These animals would require, in
winter, 123,000 pounds of hay, and 22,000 pounds of potatoes, besides what
they would pick up themselves. The natural forest most thickly peopled
with wild animals would not, in temperate climates, contain, upon the
average, one-tenth of these numbers to the same extent of surface.]
These animals browse upon the terminal buds and the tender branches,
thereby stunting, if they do not kill, the young trees, and depriving them of
all beauty and vigor of growth.
Forest Fires.
The difficulty of protecting the woods against accidental or incendiary
fires is one of the most discouraging circumstances attending the
preservation of natural and the plantation of artificial forests. [Footnote:
The disappearance of the forests of ancient Gaul and of mediaeval France
has been ascribed by some writers as much to accidental fires as to the
felling of the trees. All the treatises on sylviculture are full of narratives of
Page 488
forest fires. The woods of Corsica and Sardinia have suffered incalculable
injury from this cause, and notwithstanding the resistance of the cork-tree to
injury from common fires, the government forests of this valuable tree in
Algeria have been lately often set on fire by the natives and have sustained
immense damage. See an article by Ysabeau in the Annales Forestieres, t.
iii., p. 439; Della Marmora, Voyage en Sardaigne, 2d edition, t. i., p. 426;
Rivista Forestale del Regno d'Italia, October, 1865, p. 474. Five or six years
ago I saw in Switzerland a considerable forest, chiefly of young trees,
which had recently been burnt over. I was told that the poor of the
commune had long enjoyed a customary privilege of carrying off dead
wood and windfalls, and that they had set the forest on fire to kill the trees
and so increase the supply of their lawful plunder. The customary rights of
herdsmen, shepherds, and peasants in European forests are often an
insuperable obstacle to the success of attempts to preserve the woods or to
improve their condition. See, on this subject, Alfred Maury, Les anciens
Forets de la Gaule, chap. xxix.] In the spontaneous wood the spread of fire
is somewhat retarded by the general humidity of the soil and of the beds of
leaves which cover it. But in long droughts the superficial layer of leaves
and the dry fallen branches become as inflammable as tinder, and the fire
spreads with fearful rapidity, until its further progress is arrested by want of
material, or, more rarely, by heavy rains, sometimes caused, as many
meteorologists suppose, by the conflagration itself.
In the artificial forest the annual removal of fallen or half-dried trees and
the leaves and other droppings of the wood, though otherwise a very
injurious practice, much diminishes the rapid spread of fires; and the
absence of combustible underwood and the greater distance between the
trees are additional safeguards. But, on the other hand, the comparative
dryness of the soil, and of any leaves or twigs which may remain upon it,
and the greater facility for the passage of wind-currents through a regularly
planted and more open wood, are circumstances unfavorable to the security
injury from this cause, and notwithstanding the resistance of the cork-tree to
injury from common fires, the government forests of this valuable tree in
Algeria have been lately often set on fire by the natives and have sustained
immense damage. See an article by Ysabeau in the Annales Forestieres, t.
iii., p. 439; Della Marmora, Voyage en Sardaigne, 2d edition, t. i., p. 426;
Rivista Forestale del Regno d'Italia, October, 1865, p. 474. Five or six years
ago I saw in Switzerland a considerable forest, chiefly of young trees,
which had recently been burnt over. I was told that the poor of the
commune had long enjoyed a customary privilege of carrying off dead
wood and windfalls, and that they had set the forest on fire to kill the trees
and so increase the supply of their lawful plunder. The customary rights of
herdsmen, shepherds, and peasants in European forests are often an
insuperable obstacle to the success of attempts to preserve the woods or to
improve their condition. See, on this subject, Alfred Maury, Les anciens
Forets de la Gaule, chap. xxix.] In the spontaneous wood the spread of fire
is somewhat retarded by the general humidity of the soil and of the beds of
leaves which cover it. But in long droughts the superficial layer of leaves
and the dry fallen branches become as inflammable as tinder, and the fire
spreads with fearful rapidity, until its further progress is arrested by want of
material, or, more rarely, by heavy rains, sometimes caused, as many
meteorologists suppose, by the conflagration itself.
In the artificial forest the annual removal of fallen or half-dried trees and
the leaves and other droppings of the wood, though otherwise a very
injurious practice, much diminishes the rapid spread of fires; and the
absence of combustible underwood and the greater distance between the
trees are additional safeguards. But, on the other hand, the comparative
dryness of the soil, and of any leaves or twigs which may remain upon it,
and the greater facility for the passage of wind-currents through a regularly
planted and more open wood, are circumstances unfavorable to the security
Page 489
of the trees against this formidable danger. The natural forest, unless
isolated and of small extent, can be protected from fire only by a vigilance
too costly to be systematically practised. But the artificial wood may be
secured by a network of ditches and of paths or occasional open glades,
which both check the running of the fire and furnish the means of
approaching and combating it. [Footnote: It is stated that in the pine woods
of the Landes of Gascony a fire has never been known to cross a railway-
track or a common road. See Des Incendies, etc., dans la Region des
Maures in the Revue des Eaux et Forets for February, 1869. Many other
important articles on this subject will be found in other numbers of the same
very valuable periodical.]
The experience of 1871 ought not to be wholly without value as a lesson.
It is not possible to estimate the damage by forest fires in that disastrous
year, in what were lately the North-western States, and in Canada, but as the
demand for lumber, and consequently, its market price, are rising at a rate
higher than the interest on capital, in a geometrical ratio, one may almost
say it is probable that ten years hence those fires will be thought to have
diminished the national wealth by a larger amount than even the terrible
conflagration at Chicago.
There is no good reason why insurance companies should not guarantee
the proprietor of a wood as well as the owner of a house against damage by
fire. In Europe there is no conceivable liability to pecuniary loss which may
not be insured against. The American companies might at first be
embarrassed in estimating the risk, but the experience of a few years would
suggest safe principles, and all parties would find advantage in this
extension of security.
Forest Legislation.
isolated and of small extent, can be protected from fire only by a vigilance
too costly to be systematically practised. But the artificial wood may be
secured by a network of ditches and of paths or occasional open glades,
which both check the running of the fire and furnish the means of
approaching and combating it. [Footnote: It is stated that in the pine woods
of the Landes of Gascony a fire has never been known to cross a railway-
track or a common road. See Des Incendies, etc., dans la Region des
Maures in the Revue des Eaux et Forets for February, 1869. Many other
important articles on this subject will be found in other numbers of the same
very valuable periodical.]
The experience of 1871 ought not to be wholly without value as a lesson.
It is not possible to estimate the damage by forest fires in that disastrous
year, in what were lately the North-western States, and in Canada, but as the
demand for lumber, and consequently, its market price, are rising at a rate
higher than the interest on capital, in a geometrical ratio, one may almost
say it is probable that ten years hence those fires will be thought to have
diminished the national wealth by a larger amount than even the terrible
conflagration at Chicago.
There is no good reason why insurance companies should not guarantee
the proprietor of a wood as well as the owner of a house against damage by
fire. In Europe there is no conceivable liability to pecuniary loss which may
not be insured against. The American companies might at first be
embarrassed in estimating the risk, but the experience of a few years would
suggest safe principles, and all parties would find advantage in this
extension of security.
Forest Legislation.
Page 490
I have alleged sufficient reasons for believing that a desolation, like that
which has overwhelmed many once beautiful and fertile regions of Europe,
awaits an important part of the territory of the United States, and of other
comparatively new countries over which European civilization is now
extending its sway, unless prompt measures are taken to check the action of
destructive causes already in operation. It is almost in vain to expect that
mere restrictive legislation can do anything effectual to arrest the progress
of the evil in those countries, except so far as the state is still the proprietor
of extensive forests. Woodlands which have passed into private hands will
everywhere be managed, in spite of legal restrictions, upon the same
economical principles as other possessions, and every proprietor will, as a
general rule, fell his woods, unless he believes that it will be for his
pecuniary interest to preserve them. Few of the new provinces which the
last three centuries have brought under the control of the European race,
would tolerate any interference by the law-making power with what they
regard as the most sacred of civil rights—the right, namely, of every man to
do what he will with his own. In the Old World, even in France, whose
people, of all European nations, love best to be governed and are least
annoyed by bureaucratic supervision, law has been found impotent to
prevent the destruction, or wasteful economy, of private forests; and in
many of the mountainous departments of that country, man is at this
moment so fast laying waste the face of the earth, that the most serious fears
are entertained, not only of the depopulation of those districts, but of
enormous mischiefs to the provinces contiguous to them. [Footnote: "The
laws against clearing have never been able to prevent these operations when
the proprietor found his advantage in them, and the long series of royal
ordinances and decrees of parliaments, proclaimed from the days of
Charlemagne to our own, with a view of securing forest property against the
improvidence of its owners, have served only to show the impotence of
which has overwhelmed many once beautiful and fertile regions of Europe,
awaits an important part of the territory of the United States, and of other
comparatively new countries over which European civilization is now
extending its sway, unless prompt measures are taken to check the action of
destructive causes already in operation. It is almost in vain to expect that
mere restrictive legislation can do anything effectual to arrest the progress
of the evil in those countries, except so far as the state is still the proprietor
of extensive forests. Woodlands which have passed into private hands will
everywhere be managed, in spite of legal restrictions, upon the same
economical principles as other possessions, and every proprietor will, as a
general rule, fell his woods, unless he believes that it will be for his
pecuniary interest to preserve them. Few of the new provinces which the
last three centuries have brought under the control of the European race,
would tolerate any interference by the law-making power with what they
regard as the most sacred of civil rights—the right, namely, of every man to
do what he will with his own. In the Old World, even in France, whose
people, of all European nations, love best to be governed and are least
annoyed by bureaucratic supervision, law has been found impotent to
prevent the destruction, or wasteful economy, of private forests; and in
many of the mountainous departments of that country, man is at this
moment so fast laying waste the face of the earth, that the most serious fears
are entertained, not only of the depopulation of those districts, but of
enormous mischiefs to the provinces contiguous to them. [Footnote: "The
laws against clearing have never been able to prevent these operations when
the proprietor found his advantage in them, and the long series of royal
ordinances and decrees of parliaments, proclaimed from the days of
Charlemagne to our own, with a view of securing forest property against the
improvidence of its owners, have served only to show the impotence of
Page 491
legislative action on this subject."—Clave, Etudes sur l'Economie
Forestiere, p. 32.
"A proprietor can always contrive to clear his woods, whatever may be
done to prevent him; it is a mere question of time, and a few imprudent
cuttings, a few abuses of the right of pasturage, suffice to destry a forest in
spite of all regulations to the contrary."—Dunoyer, De la Liberte du Travail,
ii., p. 452, as quoted by Clave, p. 353.
Both authors agree that the preservation of the forests in France is
practicable only by their transfer to the state, which alone can protect them
and secure their proper treatment. It is much to be feared that even this
measure would be inadequate to preserve the forests of the American
Union. There is little respect for public property in America, and the Federal
Government, certainly, would not be the proper agent of the nation for this
purpose. It proved itself unable to protect the live-oak woods of Florida,
which were intended to be preserved for the use of the navy, and it more
than once paid contractors a high price for timber stolen from its own
forests. The authorities of the individual States might be more efficient.]
The only legal provisions from which anything is to be hoped, are such as
shall make it a matter of private advantage to the landholder to spare the
trees upon his grounds, and promote the growth of the young wood. Much
may be done by exempting standing forests from taxation, and by imposing
taxes on wood felled for fuel or for timber, something by more stringent
provisions against trespasses on forest property, and something by
premiums or honorary distinctions for judicious management of the woods;
and, in short, in this matter rewards rather than punishments must be the
incentives to obedience even to a policy of enlightened self-interest. It
might be difficult to induce governments, general or local, to make the
necessary appropriations for such purposes, but there can be no doubt that it
would be sound economy in the end.
Forestiere, p. 32.
"A proprietor can always contrive to clear his woods, whatever may be
done to prevent him; it is a mere question of time, and a few imprudent
cuttings, a few abuses of the right of pasturage, suffice to destry a forest in
spite of all regulations to the contrary."—Dunoyer, De la Liberte du Travail,
ii., p. 452, as quoted by Clave, p. 353.
Both authors agree that the preservation of the forests in France is
practicable only by their transfer to the state, which alone can protect them
and secure their proper treatment. It is much to be feared that even this
measure would be inadequate to preserve the forests of the American
Union. There is little respect for public property in America, and the Federal
Government, certainly, would not be the proper agent of the nation for this
purpose. It proved itself unable to protect the live-oak woods of Florida,
which were intended to be preserved for the use of the navy, and it more
than once paid contractors a high price for timber stolen from its own
forests. The authorities of the individual States might be more efficient.]
The only legal provisions from which anything is to be hoped, are such as
shall make it a matter of private advantage to the landholder to spare the
trees upon his grounds, and promote the growth of the young wood. Much
may be done by exempting standing forests from taxation, and by imposing
taxes on wood felled for fuel or for timber, something by more stringent
provisions against trespasses on forest property, and something by
premiums or honorary distinctions for judicious management of the woods;
and, in short, in this matter rewards rather than punishments must be the
incentives to obedience even to a policy of enlightened self-interest. It
might be difficult to induce governments, general or local, to make the
necessary appropriations for such purposes, but there can be no doubt that it
would be sound economy in the end.
Page 492
In countries where there exist municipalities endowed with an intelligent
public spirit, the purchase and control of forests by such corporations would
often prove advantageous; and in some of the provinces of Northern
Lombardy, experience has shown that such operations may be conducted
with great benefit to all the interests connected with the proper management
of the woods. In Switzerland, on the other hand, except in some few cases
where woods have been preserved as a defence against avalanches, the
forests of the communes have been of little advantage to the public
interests, and have very generally gone to decay. [Footnote: A better
economy has been of late introduced into the management of the forest in
Switzerland. Excellent official reports on the subject have been published
and important legal provisions adopted.] The rights of pasturage,
everywhere destructive to trees, combined with toleration of trespasses,
have so reduced their value, that there is, too often, nothing left that is
worth protecting. In the canton of Ticino, the peasants have very frequently
voted to sell the town-woods and divide the proceeds among the
corporators. The sometimes considerable sums thus received are
squandered in wild revelry, and the sacrifice of the forests brings not even a
momentary benefit to the proprietors. [Footnote: See in Berlepscu, Die
Alpen, chapter Holzschlager und Flosser, a lively account of the sale of a
communal wood.]
Fortunately for the immense economical and sanitary interests involved
in this branch of rural and industrial husbandry, public opinion in many
parts of the United States is thoroughly roused to the importance of the
subject. In the Eastern States, plantations of a certain extent have been
made, and a wiser system is pursued in the treatment of the remaining
native woods. [Footnote: When the census of 1860 was taken, the States of
Maine and New York produced and exported lumber in abundance. Neither
of them now has timber enough for domestic use, and they are both
compelled to draw much of their supply from Canada and the West.]
public spirit, the purchase and control of forests by such corporations would
often prove advantageous; and in some of the provinces of Northern
Lombardy, experience has shown that such operations may be conducted
with great benefit to all the interests connected with the proper management
of the woods. In Switzerland, on the other hand, except in some few cases
where woods have been preserved as a defence against avalanches, the
forests of the communes have been of little advantage to the public
interests, and have very generally gone to decay. [Footnote: A better
economy has been of late introduced into the management of the forest in
Switzerland. Excellent official reports on the subject have been published
and important legal provisions adopted.] The rights of pasturage,
everywhere destructive to trees, combined with toleration of trespasses,
have so reduced their value, that there is, too often, nothing left that is
worth protecting. In the canton of Ticino, the peasants have very frequently
voted to sell the town-woods and divide the proceeds among the
corporators. The sometimes considerable sums thus received are
squandered in wild revelry, and the sacrifice of the forests brings not even a
momentary benefit to the proprietors. [Footnote: See in Berlepscu, Die
Alpen, chapter Holzschlager und Flosser, a lively account of the sale of a
communal wood.]
Fortunately for the immense economical and sanitary interests involved
in this branch of rural and industrial husbandry, public opinion in many
parts of the United States is thoroughly roused to the importance of the
subject. In the Eastern States, plantations of a certain extent have been
made, and a wiser system is pursued in the treatment of the remaining
native woods. [Footnote: When the census of 1860 was taken, the States of
Maine and New York produced and exported lumber in abundance. Neither
of them now has timber enough for domestic use, and they are both
compelled to draw much of their supply from Canada and the West.]
Page 493
Important experiments have been tried in Massachusetts on the propagation
of forest-trees on seashore bluffs exposed to strong winds. This had been
generally supposed to be impossible, but the experiments in question afford
a gratifying proof that this is an erroneous opinion. Piper gives an
interesting account of Mr. Tudor's success in planting trees on the bleak and
barren shore of Nahant. "Mr. Tudor," observes he, "has planted more than
ten thousand trees at Nahaut, and, by the results of his experiments, has
fully demonstrated that trees, properly cared for in the beginning, may be
made to grow up to the very bounds of the ocean, exposed to the biting of
the wind and the spray of the sea. The only shelter they require is, at first,
some interruption to break the current of the wind, such as fences, houses,
or other trees." [Footnote: Trees of America, p. 10.]
Young trees protected against the wind by a fence will somewhat overtop
their shelter, and every tree will serve as a screen to a taller one behind it.
Extensive groves have thus been formed in situations where an isolated tree
would not grow at all.
The people of the Far West have thrown themselves into the work, we
cannot say of restoration, but rather of creation, of woodland, with much of
the passionate energy which marks their action in reference to other modes
of physical improvement. California has appointed a State forester with a
liberal salary, and made such legal provisions and appropriations as to
render the discharge of his duties effectual. The hands that built the Pacific
Railroad at the rate of miles in a day are now busy in planting belts of trees
to shelter the track from snow- drifts, and to supply, at a future day, timber
for ties and fuel for the locomotives. The settlers on the open plains, too, are
not less actively engaged in the propagation of the woods, and if we can put
faith in the official statistics on the subject, not thousands but millions of
trees are annually planted on the prairies.
of forest-trees on seashore bluffs exposed to strong winds. This had been
generally supposed to be impossible, but the experiments in question afford
a gratifying proof that this is an erroneous opinion. Piper gives an
interesting account of Mr. Tudor's success in planting trees on the bleak and
barren shore of Nahant. "Mr. Tudor," observes he, "has planted more than
ten thousand trees at Nahaut, and, by the results of his experiments, has
fully demonstrated that trees, properly cared for in the beginning, may be
made to grow up to the very bounds of the ocean, exposed to the biting of
the wind and the spray of the sea. The only shelter they require is, at first,
some interruption to break the current of the wind, such as fences, houses,
or other trees." [Footnote: Trees of America, p. 10.]
Young trees protected against the wind by a fence will somewhat overtop
their shelter, and every tree will serve as a screen to a taller one behind it.
Extensive groves have thus been formed in situations where an isolated tree
would not grow at all.
The people of the Far West have thrown themselves into the work, we
cannot say of restoration, but rather of creation, of woodland, with much of
the passionate energy which marks their action in reference to other modes
of physical improvement. California has appointed a State forester with a
liberal salary, and made such legal provisions and appropriations as to
render the discharge of his duties effectual. The hands that built the Pacific
Railroad at the rate of miles in a day are now busy in planting belts of trees
to shelter the track from snow- drifts, and to supply, at a future day, timber
for ties and fuel for the locomotives. The settlers on the open plains, too, are
not less actively engaged in the propagation of the woods, and if we can put
faith in the official statistics on the subject, not thousands but millions of
trees are annually planted on the prairies.
Page 494
These experiments are of much scientific as well as economical interest.
The prairies have never been wooded, so far as we know their history, and it
has been contended that successful sylviculture would be impracticable in
those regions from the want of rain. But we are acquainted with no soil and
climate which favor the production of herbage and forbid the rearing of
trees, and, as Bryant well observes, "it seems certain that where grass will
grow trees may be made to grow also." [Footnote: The origin of our
Western treeless prairies and plains, as of the Russian steppes, which much
resemble them, is obscure, but the want of forests upon them, seems to be
due to climatic conditions and especially to a want of spring and summer
rains, which prevents the spontaneous formation of forests upon them,
though not necessarily the growth of trees artificially planted and cared for.
Climatic conditions more or less resembling those of our Western territories
produce analogous effects in India. Much valuable information on the
relations between climate and forest vegetation will be found in an article
by Dr. Brandis, On the Distribution of Forests in India, in Ocean Highways
for October, 1872.
In the more eastwardly prairie region fires have done much to prevent the
spread of the native groves, and throughout the whole woodless plains the
pastorage of the buffalo alone would suffice to prevent a forest growth. The
prairies were the proper feeding-grounds of the bison, and the vast number
of those animals is connected, as cause or consequence, with the existence
of these vast pastures. The bison, indeed, could not convert the forest into a
pasture, but he would do much to prevent the pasture from becoming a
forest.
There is positive evidence that some of the American tribes possessed
large herds of domesticated bisons. See Humboldt, Ansichten der Natur, i.,
pp. 71-73. What authorizes us to affirm that this was simply the wild bison
The prairies have never been wooded, so far as we know their history, and it
has been contended that successful sylviculture would be impracticable in
those regions from the want of rain. But we are acquainted with no soil and
climate which favor the production of herbage and forbid the rearing of
trees, and, as Bryant well observes, "it seems certain that where grass will
grow trees may be made to grow also." [Footnote: The origin of our
Western treeless prairies and plains, as of the Russian steppes, which much
resemble them, is obscure, but the want of forests upon them, seems to be
due to climatic conditions and especially to a want of spring and summer
rains, which prevents the spontaneous formation of forests upon them,
though not necessarily the growth of trees artificially planted and cared for.
Climatic conditions more or less resembling those of our Western territories
produce analogous effects in India. Much valuable information on the
relations between climate and forest vegetation will be found in an article
by Dr. Brandis, On the Distribution of Forests in India, in Ocean Highways
for October, 1872.
In the more eastwardly prairie region fires have done much to prevent the
spread of the native groves, and throughout the whole woodless plains the
pastorage of the buffalo alone would suffice to prevent a forest growth. The
prairies were the proper feeding-grounds of the bison, and the vast number
of those animals is connected, as cause or consequence, with the existence
of these vast pastures. The bison, indeed, could not convert the forest into a
pasture, but he would do much to prevent the pasture from becoming a
forest.
There is positive evidence that some of the American tribes possessed
large herds of domesticated bisons. See Humboldt, Ansichten der Natur, i.,
pp. 71-73. What authorizes us to affirm that this was simply the wild bison
Page 495
reclaimed, and why may we not, with equal probability, believe that the
migratory prairie-buffalo is the progeny of the domestic animal run wild?
There are, both on the prairies, as in Wisconsin, and in deep forests, as in
Ohio, extensive remains of a primitive people, who must have been more
numerous and more advanced in art than the present Indian tribes. There
can be no doubt that the woods where such earthworks are found in Ohio
were cleared by them, and that the vicinity of these fortresses or temples
was inhabited by a large population. Nothing forbids the supposition that
the prairies were cleared by the same or a similar people, and that the
growth of trees upon them has been prevented by fires and grazing, while
the restoration of the woods in Ohio may be due to the abandonment of that
region by its original inhabitants. The climatic conditions unfavorable to the
spontaneous growth of trees on the prairies may possibly be an effect of too
extensive clearings, rather than a cause of the want of woods.
It is disputed whether the steppes of Russia were ever wooded. They
were certainly bare of forest growth at a very remote period; for Herodotus
describes the country of the Scythians between the Ister and the Tanais as
woodless, with the exception of the small province of Xylaea between the
Dnieper and the Gulf of Perekop. They are known to have been occupied by
a large nomade and pastoral population down to the sixteenth century,
though these tribes are now much reduced in numbers. The habits of such
races are scarcely less destructive to the forest than those of civilized life.
Pastoral tribes do not employ much wood for fuel or for construction, but
they carelessly or recklessly burn down the forests, and their cattle
effectually check the growth of young trees wherever their range extends.
At present, the furious winds which sweep over the plains, the droughts
of summer, and the rights and abuses of pasturage, constitute very
formidable obstacles to the employment of measures which have been
migratory prairie-buffalo is the progeny of the domestic animal run wild?
There are, both on the prairies, as in Wisconsin, and in deep forests, as in
Ohio, extensive remains of a primitive people, who must have been more
numerous and more advanced in art than the present Indian tribes. There
can be no doubt that the woods where such earthworks are found in Ohio
were cleared by them, and that the vicinity of these fortresses or temples
was inhabited by a large population. Nothing forbids the supposition that
the prairies were cleared by the same or a similar people, and that the
growth of trees upon them has been prevented by fires and grazing, while
the restoration of the woods in Ohio may be due to the abandonment of that
region by its original inhabitants. The climatic conditions unfavorable to the
spontaneous growth of trees on the prairies may possibly be an effect of too
extensive clearings, rather than a cause of the want of woods.
It is disputed whether the steppes of Russia were ever wooded. They
were certainly bare of forest growth at a very remote period; for Herodotus
describes the country of the Scythians between the Ister and the Tanais as
woodless, with the exception of the small province of Xylaea between the
Dnieper and the Gulf of Perekop. They are known to have been occupied by
a large nomade and pastoral population down to the sixteenth century,
though these tribes are now much reduced in numbers. The habits of such
races are scarcely less destructive to the forest than those of civilized life.
Pastoral tribes do not employ much wood for fuel or for construction, but
they carelessly or recklessly burn down the forests, and their cattle
effectually check the growth of young trees wherever their range extends.
At present, the furious winds which sweep over the plains, the droughts
of summer, and the rights and abuses of pasturage, constitute very
formidable obstacles to the employment of measures which have been
Page 496
attended with so valuable results on the sand-wastes of France and
Germany. The Russian Government has, however, attempted the wooding
of the steppes, and there are thriving plantations in the neighborhood of
Odessa, where the soil is of a particularly loose and sandy character. The
tree best suited to this locality, and, as there is good reason to suppose, to
sand plains in general, is the Ailanthus glandulosa, or Japan varnish-tree.
The remarkable success which has crowned the experiments with the
ailanthus at Odessa, will, no doubt, stimulate to similar trials elsewhere, and
it seems not improbable that the arundo and the maritime pine, which have
fixed so many thousand acres of drifting sands in Western Europe, will be,
partially at leaat, superseded by the tamarisk and the varnish-tree.
According to Hohenstein, Der Wald, pp. 228, 229, an extensive
plantation of pines—a tree new to Southern Russia—was commenced in
1842, on the barren and sandy banks of the Ingula, near Elisabethgrod, and
has met with very flattering success. Other experiments in sylviculture at
different points on the steppes promise valuable results.] In any case the
question will now be subjected to a practical test, and the plantations are so
extensive, and, as is reported, so thrifty in growth, that one generation will
suffice to determine with certainty and precision how far climate is affected
by clothing with wood a vast territory naturally destitute of that protection.
I have thus far spoken only of the preservation and training of existing
woods, not of the planting of new forests, because European experience, to
which alone we can appeal, is conversant only with conditions so different
from those of our own climate, soil, and arboreal vegetation, that precedents
drawn from it cannot be relied upon as entirely safe rules for our guidance
in that branch of rural economy. [Footnote: Many valuable suggestions on
this subject will be found in Bryant, Forest Trees, chap. vi. et seqq.]
Germany. The Russian Government has, however, attempted the wooding
of the steppes, and there are thriving plantations in the neighborhood of
Odessa, where the soil is of a particularly loose and sandy character. The
tree best suited to this locality, and, as there is good reason to suppose, to
sand plains in general, is the Ailanthus glandulosa, or Japan varnish-tree.
The remarkable success which has crowned the experiments with the
ailanthus at Odessa, will, no doubt, stimulate to similar trials elsewhere, and
it seems not improbable that the arundo and the maritime pine, which have
fixed so many thousand acres of drifting sands in Western Europe, will be,
partially at leaat, superseded by the tamarisk and the varnish-tree.
According to Hohenstein, Der Wald, pp. 228, 229, an extensive
plantation of pines—a tree new to Southern Russia—was commenced in
1842, on the barren and sandy banks of the Ingula, near Elisabethgrod, and
has met with very flattering success. Other experiments in sylviculture at
different points on the steppes promise valuable results.] In any case the
question will now be subjected to a practical test, and the plantations are so
extensive, and, as is reported, so thrifty in growth, that one generation will
suffice to determine with certainty and precision how far climate is affected
by clothing with wood a vast territory naturally destitute of that protection.
I have thus far spoken only of the preservation and training of existing
woods, not of the planting of new forests, because European experience, to
which alone we can appeal, is conversant only with conditions so different
from those of our own climate, soil, and arboreal vegetation, that precedents
drawn from it cannot be relied upon as entirely safe rules for our guidance
in that branch of rural economy. [Footnote: Many valuable suggestions on
this subject will be found in Bryant, Forest Trees, chap. vi. et seqq.]
Page 497
I apprehend that one rule, which is certainly alike applicable to both sides
of the Atlantic—that, namely, of the absolute exclusion of domestic
quadrupeds from all woods, old or young, not destined for the axe—would
be least likely to be observed in our practice. The need of shade for cattle,
and our inveterate habits in this respect, are much more serious obstacles to
compliance with this precept than any inherent difficulty in the thing itself;
for there is no good reason why our cattle may not be kept out of our woods
as well as out of our wheatfields. When forest-planting is earnestly and
perseveringly practised, means of overcoming this difficulty will be found,
and our husbandry will be modified to meet the exigency.
The best general advice that can be offered, in the want of an
experimental code, is to make every plantation consist of a great variety of
trees, and this not only because nature favors a diversified forest-crop, but
because the chances of success among a multitude of species are far greater
than if we confine ourselves to one or two.
It will doubtless be found that in our scorching summer, especially on
bare plains, shade for young plants is even more necessary than in most
parts of Europe, and hence a fair proportion of rapidly growing trees and
shrubs, even if themselves of little intrinsic value, ought to be regarded as
an indispensable feature in every young plantation. These trees should be of
species which bear a full supply of air and light, and therefore, in the order
of nature, precede those which are of greater value for the permanent wood;
and it would be a prudent measure to seed the ground with a stock of such
plants, a year or two before sowing or transplanting the more valuable
varieties.
More specific rules than these cannot at present well be given, but very
brief experiments, even if not in all respects wisely conducted, will suffice
to determine the main question: whether in a given locality this or that
of the Atlantic—that, namely, of the absolute exclusion of domestic
quadrupeds from all woods, old or young, not destined for the axe—would
be least likely to be observed in our practice. The need of shade for cattle,
and our inveterate habits in this respect, are much more serious obstacles to
compliance with this precept than any inherent difficulty in the thing itself;
for there is no good reason why our cattle may not be kept out of our woods
as well as out of our wheatfields. When forest-planting is earnestly and
perseveringly practised, means of overcoming this difficulty will be found,
and our husbandry will be modified to meet the exigency.
The best general advice that can be offered, in the want of an
experimental code, is to make every plantation consist of a great variety of
trees, and this not only because nature favors a diversified forest-crop, but
because the chances of success among a multitude of species are far greater
than if we confine ourselves to one or two.
It will doubtless be found that in our scorching summer, especially on
bare plains, shade for young plants is even more necessary than in most
parts of Europe, and hence a fair proportion of rapidly growing trees and
shrubs, even if themselves of little intrinsic value, ought to be regarded as
an indispensable feature in every young plantation. These trees should be of
species which bear a full supply of air and light, and therefore, in the order
of nature, precede those which are of greater value for the permanent wood;
and it would be a prudent measure to seed the ground with a stock of such
plants, a year or two before sowing or transplanting the more valuable
varieties.
More specific rules than these cannot at present well be given, but very
brief experiments, even if not in all respects wisely conducted, will suffice
to determine the main question: whether in a given locality this or that
Page 498
particular tree can advantageously be propagated or introduced. The special
processes of arboriculture suited to the ends of the planter may be gathered
partly from cautious imitation of European practice, and partly from an
experience which, though not pronouncing definitively in a single season,
will, nevertheless, suggest appropriate methods of planting and training the
wood within a period not disproportioned to the importance of the object.
[Footnote: For very judicious suggestions on experiments in sylviculture,
see the Rev. Frederick Starr's remarkable paper on the American Forests in
the Transactions of the Agricultural Society for -.]
The growth of arboreal vegetation is comparatively slow, and we are
often told that, though he who buries an acorn may hope to see it shoot up
to a miniature resemblance of the majestic tree which shall shade his remote
descendants, yet the longest life hardly embraces the seedtime and the
harvest of a forest. The planter of a wood, it is said, must be actuated by
higher motives than those of an investment, the profits of which consist in
direct pecuniary gain to himself or even to his posterity; for if, in rare cases,
an artificial forest may, in a generation or two, more than repay its original
cost, still, in general, the value of its timber will not return the capital
expended and the interest accrued. [Footnote: According to Clave (Etudes,
p. 159), the net revenue from the forests of the state in France, making no
allowance for interest on the capital represented by the forest, is two dollars
per acre. In Saxony it is about the same, though the cost of administration is
twice as much as in France; in Wurtemberg it is about a dollar an acre; and
in Prussia, where half the income is consumed in the expenses of
administration, it sinks to less than half a dollar. This low rate in Prussia and
other German states is partly explained by the fact that a considerable
proportion of the annual product of the wood is either conceded to persons
claiming prescriptive rights, or sold, at a very small price, to the poor.
Taking into account the capital invested in forest-land, and adding interest
upon it, Pressler calculates that a pine wood, managed with a view to felling
processes of arboriculture suited to the ends of the planter may be gathered
partly from cautious imitation of European practice, and partly from an
experience which, though not pronouncing definitively in a single season,
will, nevertheless, suggest appropriate methods of planting and training the
wood within a period not disproportioned to the importance of the object.
[Footnote: For very judicious suggestions on experiments in sylviculture,
see the Rev. Frederick Starr's remarkable paper on the American Forests in
the Transactions of the Agricultural Society for -.]
The growth of arboreal vegetation is comparatively slow, and we are
often told that, though he who buries an acorn may hope to see it shoot up
to a miniature resemblance of the majestic tree which shall shade his remote
descendants, yet the longest life hardly embraces the seedtime and the
harvest of a forest. The planter of a wood, it is said, must be actuated by
higher motives than those of an investment, the profits of which consist in
direct pecuniary gain to himself or even to his posterity; for if, in rare cases,
an artificial forest may, in a generation or two, more than repay its original
cost, still, in general, the value of its timber will not return the capital
expended and the interest accrued. [Footnote: According to Clave (Etudes,
p. 159), the net revenue from the forests of the state in France, making no
allowance for interest on the capital represented by the forest, is two dollars
per acre. In Saxony it is about the same, though the cost of administration is
twice as much as in France; in Wurtemberg it is about a dollar an acre; and
in Prussia, where half the income is consumed in the expenses of
administration, it sinks to less than half a dollar. This low rate in Prussia and
other German states is partly explained by the fact that a considerable
proportion of the annual product of the wood is either conceded to persons
claiming prescriptive rights, or sold, at a very small price, to the poor.
Taking into account the capital invested in forest-land, and adding interest
upon it, Pressler calculates that a pine wood, managed with a view to felling
Page 499
it when eighty years old, would yield one-eighth of one per cent. annual
profit; a fir wood, at one hundred years, one-sixth of one per cent.; a beech
wood, at one hundred and twenty years, one-fourth of one per cent. The
same author gives the net income of the New Forest in England, over and
above expenses, interest not computed, at twenty-five cents per acre only. In
America, where no expense is bestowed upon the woods, the value of the
annual growth has generally been estimated much higher. Forest-trees are
often planted in Europe for what may be called an early crop. Thus in
Germany acorns are sown and the young seedlings cultivated like ordinary
field-vegetables, and cut at the age of a very few years for the sake of the
bark and young twigs used by tanners. In England, trees are grown at the
rate of two thousand to the acre, and cut for props in the mines at the
diameter of a few inches. Plantations for hoop-poles, and other special
purposes requiring small timber, would, no doubt, often prove high
remunerative.] But the modern improved methods of sylviculture show
vastly more favorable financial results; and when we consider the immense
collateral advantages derived from the presence of the forest, the terrible
evils necessarily resulting from its destruction, we cannot but admit that the
preservation of existing woods, and the more costly extension and creation
of them where they have been unduly reduced or have never existed, are
among the plainest dictates of self-interest and most obvious of the duties
which this age owes to those that are to come after it.
Financial Results of Forest Plantation.
Upon the whole, I am persuaded that the financial statistics which are
found in French and German authors, as the results of European experience
in forest economy, present the question under a too unfavorable aspect; and
therefore these calculations ought not to discourage landed proprietors from
making experiments on this subject. These statistics apply to woods whose
profit; a fir wood, at one hundred years, one-sixth of one per cent.; a beech
wood, at one hundred and twenty years, one-fourth of one per cent. The
same author gives the net income of the New Forest in England, over and
above expenses, interest not computed, at twenty-five cents per acre only. In
America, where no expense is bestowed upon the woods, the value of the
annual growth has generally been estimated much higher. Forest-trees are
often planted in Europe for what may be called an early crop. Thus in
Germany acorns are sown and the young seedlings cultivated like ordinary
field-vegetables, and cut at the age of a very few years for the sake of the
bark and young twigs used by tanners. In England, trees are grown at the
rate of two thousand to the acre, and cut for props in the mines at the
diameter of a few inches. Plantations for hoop-poles, and other special
purposes requiring small timber, would, no doubt, often prove high
remunerative.] But the modern improved methods of sylviculture show
vastly more favorable financial results; and when we consider the immense
collateral advantages derived from the presence of the forest, the terrible
evils necessarily resulting from its destruction, we cannot but admit that the
preservation of existing woods, and the more costly extension and creation
of them where they have been unduly reduced or have never existed, are
among the plainest dictates of self-interest and most obvious of the duties
which this age owes to those that are to come after it.
Financial Results of Forest Plantation.
Upon the whole, I am persuaded that the financial statistics which are
found in French and German authors, as the results of European experience
in forest economy, present the question under a too unfavorable aspect; and
therefore these calculations ought not to discourage landed proprietors from
making experiments on this subject. These statistics apply to woods whose
Page 500
present condition is, in an eminent degree, the effect of previous long-
continued mismanagement; and there is much reason to believe that in the
propitious climate of the United States new plantations, regulated
substantially according to the methods of De Courval, Chambrelent, and
Chevandier, and accompanied with the introduction of exotic trees, as, for
example, the Australian caruarina and eucalyptus [Footnote: Although the
eucalyptus thrives admirably in Algeria—where it attains a height of from
fifty to sixty feet, and a diameter of fifteen or sixteen inches, in six years
from the seed—and in some restricted localities in Southern Europe, it will
not bear the winters even of Florence, and consequently cannot be expected
to flourish in any part of the United States except the extreme South and
California. The writer of a somewhat enthusiastic article on this latter State,
in Harper's Monthly for July, 1872, affirms that he saw a eucalyptus "eight
years from a small cutting, which was seventy-five feet in height, and two
feet and a half in diameter at the base."
The paulownia, which thrives in Northern Italy, has a wood of little
value, but the tree would serve well as a shelter for seedlings and young
plants of more valuable species, and in other cases where a temporary shade
is urgently needed. The young shoots, from a stem polled the previous
season, almost surpass even the eucalyptus in rapidity of growth. Such a
shoot from a tree not six inches in diameter, which I had an opportunity of
daily observing, from the bursting out of the bud from the bark of the parent
stem in April till November of the same year, acquired in that interval a
diameter of between four and five inches and a height of above twenty
feet.] which, latter, it is said, has a growth at least five, and, according to
some, ten times more rapid than that of the oak—would prove good
investments even in an economical aspect. [Footnote: The economical
statistics of Grigor, Arboriculture, Edinburgh, 1868, are very encouraging.
In the preface to that work the author says: "Having formed several large
plantations nearly forty years ago, which are still standing, in the Highlands
continued mismanagement; and there is much reason to believe that in the
propitious climate of the United States new plantations, regulated
substantially according to the methods of De Courval, Chambrelent, and
Chevandier, and accompanied with the introduction of exotic trees, as, for
example, the Australian caruarina and eucalyptus [Footnote: Although the
eucalyptus thrives admirably in Algeria—where it attains a height of from
fifty to sixty feet, and a diameter of fifteen or sixteen inches, in six years
from the seed—and in some restricted localities in Southern Europe, it will
not bear the winters even of Florence, and consequently cannot be expected
to flourish in any part of the United States except the extreme South and
California. The writer of a somewhat enthusiastic article on this latter State,
in Harper's Monthly for July, 1872, affirms that he saw a eucalyptus "eight
years from a small cutting, which was seventy-five feet in height, and two
feet and a half in diameter at the base."
The paulownia, which thrives in Northern Italy, has a wood of little
value, but the tree would serve well as a shelter for seedlings and young
plants of more valuable species, and in other cases where a temporary shade
is urgently needed. The young shoots, from a stem polled the previous
season, almost surpass even the eucalyptus in rapidity of growth. Such a
shoot from a tree not six inches in diameter, which I had an opportunity of
daily observing, from the bursting out of the bud from the bark of the parent
stem in April till November of the same year, acquired in that interval a
diameter of between four and five inches and a height of above twenty
feet.] which, latter, it is said, has a growth at least five, and, according to
some, ten times more rapid than that of the oak—would prove good
investments even in an economical aspect. [Footnote: The economical
statistics of Grigor, Arboriculture, Edinburgh, 1868, are very encouraging.
In the preface to that work the author says: "Having formed several large
plantations nearly forty years ago, which are still standing, in the Highlands
Page 501
of Scotland, I can refer to them as, after paying every expense, yielding a
revenue equal to that of the finest arable land in the country, where the
ground previously to these formations was not worth a shilling an acre."
See also Hartig, Ueber den Wachsthumsgang und Ertrag der Buche, Eiche
und Kiefer, 1869, and especially Bryant, Forest Trees, chap. ix.]
There is no doubt that they would pay the expenses of their planting at no
distant period, at least in every case where irrigation is possible, and in very
many situations, terraces, ditches, or even horizontal furrows upon the
hillsides, would answer as a substitute for more artificial irrigation. Large
proprietors would receive important indirect benefits from the shelter and
the moisture which forests furnish for the lands in their neighborhood, and
eventually from the accumulation of vegetable mould in the woods.
[Footnote: The fertility of newly cleared land is by no means due entirely to
the accumulation of decayed vegetable matter on its surface, and to the
decomposition of the mineral constituents of the soil by the gases emitted
by the fallen leaves. Sachs has shown that the roots of living plants exercise
a most powerful solvent action on rocks, and hence stones are disintegrated
and resolved into elements of vegetable nutrition, by the chemical agency
of the forest, more rapidly than by frost, rain, and other meteorological
influences.] The security of the investment, as in the case of all real-estate,
is a strong argument for undertaking such plantations, and a moderate
amount of government patronage and encouragement would be sufficient to
render the creation of new forests an object of private interest as well as of
public advantage, especially in a country where the necessity is so urgent
and the climate so favorable as in the United States.
Instability of American Life.
All human institutions, associate arrangements, modes of life, have their
characteristic imperfections. The natural, perhaps the necessary defect of
revenue equal to that of the finest arable land in the country, where the
ground previously to these formations was not worth a shilling an acre."
See also Hartig, Ueber den Wachsthumsgang und Ertrag der Buche, Eiche
und Kiefer, 1869, and especially Bryant, Forest Trees, chap. ix.]
There is no doubt that they would pay the expenses of their planting at no
distant period, at least in every case where irrigation is possible, and in very
many situations, terraces, ditches, or even horizontal furrows upon the
hillsides, would answer as a substitute for more artificial irrigation. Large
proprietors would receive important indirect benefits from the shelter and
the moisture which forests furnish for the lands in their neighborhood, and
eventually from the accumulation of vegetable mould in the woods.
[Footnote: The fertility of newly cleared land is by no means due entirely to
the accumulation of decayed vegetable matter on its surface, and to the
decomposition of the mineral constituents of the soil by the gases emitted
by the fallen leaves. Sachs has shown that the roots of living plants exercise
a most powerful solvent action on rocks, and hence stones are disintegrated
and resolved into elements of vegetable nutrition, by the chemical agency
of the forest, more rapidly than by frost, rain, and other meteorological
influences.] The security of the investment, as in the case of all real-estate,
is a strong argument for undertaking such plantations, and a moderate
amount of government patronage and encouragement would be sufficient to
render the creation of new forests an object of private interest as well as of
public advantage, especially in a country where the necessity is so urgent
and the climate so favorable as in the United States.
Instability of American Life.
All human institutions, associate arrangements, modes of life, have their
characteristic imperfections. The natural, perhaps the necessary defect of
Page 502
ours, is their instability, their want of fixedness, not in form only, but even
in spirit. The face of physical nature in the United States shares this
incessant fluctuation, and the landscape is as variable as the habits of the
population. It is time for some abatement in the restless love of change
which characterizes us, and makes us almost a nomade rather than a
sedentary people. [Footnote: It is rare that a middle-aged American dies in
the house where he was born, or an old man even in that which he has built;
and this is scarcely less true of the rural districts, where every man owns his
habitation, than of the city, where the majority live hired houses. This life of
incessant flitting is unfavorable for the execution of permanent
improvements of every sort, and especially of those which, like the forest,
are slow in repaying any part of the capital expended in them. It requires a
very generous spirit in a landholder to plant a wood on a farm he expects to
sell, or which he knows will pass out of the hands of his descendants at his
death. But the very fact of having begun a plantation would attach the
proprietor more strongly to the soil for which he had made such a sacrifice;
and the paternal acres would have a greater value in the eyes of a
succeeding generation, if thus improved and beautified by the labors of
those from whom they were inherited. Landed property, therefore, the
transfer of which is happily free from every legal impediment or restriction
in the United States, would find, in the feelings thus prompted, a moral
check against a too frequent change of owners, and would tend to remain
long enough in one proprietor or one family to admit of gradual
improvements which would increase its value both to the possessor and to
the state.] We have now felled forest enough everywhere, in many districts
far too much. Let us restore this one element of material life to its normal
proportions, and devise means of maintaining the permanence of its
relations to the fields, the meadows, and the pastures, to the rain and the
dews of heaven, to the springs and rivulets with which it waters the earth.
The establishment of an approximately fixed ratio between the two most
in spirit. The face of physical nature in the United States shares this
incessant fluctuation, and the landscape is as variable as the habits of the
population. It is time for some abatement in the restless love of change
which characterizes us, and makes us almost a nomade rather than a
sedentary people. [Footnote: It is rare that a middle-aged American dies in
the house where he was born, or an old man even in that which he has built;
and this is scarcely less true of the rural districts, where every man owns his
habitation, than of the city, where the majority live hired houses. This life of
incessant flitting is unfavorable for the execution of permanent
improvements of every sort, and especially of those which, like the forest,
are slow in repaying any part of the capital expended in them. It requires a
very generous spirit in a landholder to plant a wood on a farm he expects to
sell, or which he knows will pass out of the hands of his descendants at his
death. But the very fact of having begun a plantation would attach the
proprietor more strongly to the soil for which he had made such a sacrifice;
and the paternal acres would have a greater value in the eyes of a
succeeding generation, if thus improved and beautified by the labors of
those from whom they were inherited. Landed property, therefore, the
transfer of which is happily free from every legal impediment or restriction
in the United States, would find, in the feelings thus prompted, a moral
check against a too frequent change of owners, and would tend to remain
long enough in one proprietor or one family to admit of gradual
improvements which would increase its value both to the possessor and to
the state.] We have now felled forest enough everywhere, in many districts
far too much. Let us restore this one element of material life to its normal
proportions, and devise means of maintaining the permanence of its
relations to the fields, the meadows, and the pastures, to the rain and the
dews of heaven, to the springs and rivulets with which it waters the earth.
The establishment of an approximately fixed ratio between the two most
Page 503
broadly characterized distinctions of rural surface—woodland and
ploughland—would involve a certain persistence of character in all the
branches of industry, all the occupations and habits of life, which depend
upon or are immediately connected with either, without implying a rigidity
that should exclude flexibility of accommodation to the many changes of
external circumstance which human wisdom can neither prevent nor
foresee, and would thus help us to become, more emphatically, a well-
ordered and stable commonwealth, and, not less conspicuously, a people of
progress.
CHAPTER IV.
THE WATERS.
Land Artificially won from the Waters—Great Works of Material
Improvement—Draining of Lincolnshire Fens—Incursions of the Sea in the
Netherlands—Origin of Sea-dikes—Gain and Loss of Land in the
Netherlands—Marine Deposits on the Coast of Netherlands—Draining of
Lake of Haarlem—Draining of the Zuiderzee—Geographical Effects of
Improvements in the Netherlands—Ancient Hydraulic Works—Draining of
Lake Celano by Prince Torlonia—Incidental Consequences of draining
Lakes—Draining of Marshes—Agricultural Draining—Meteorological
Effects of Draining—Geographical Effects of Draining—Geographical
Effects of Aqueducts and Canals—Antiquity of Irrigation—Irrigation in
Palestine, India, and Egypt—Irrigation in Europe—Meteorological
Effects of Irrigation—Water withdrawn from Rivers for
Irrigation—Injurious Effects of Rice-culture—Salts Deposited by Water
of Irrigation—Subterranean Waters—Artesian Wells—Artificial
Springs—Economizing Precipitation—Inundations in France—Basins of
Reception—Diversion of Rivers—Glacier Lakes—River Embankments—
ploughland—would involve a certain persistence of character in all the
branches of industry, all the occupations and habits of life, which depend
upon or are immediately connected with either, without implying a rigidity
that should exclude flexibility of accommodation to the many changes of
external circumstance which human wisdom can neither prevent nor
foresee, and would thus help us to become, more emphatically, a well-
ordered and stable commonwealth, and, not less conspicuously, a people of
progress.
CHAPTER IV.
THE WATERS.
Land Artificially won from the Waters—Great Works of Material
Improvement—Draining of Lincolnshire Fens—Incursions of the Sea in the
Netherlands—Origin of Sea-dikes—Gain and Loss of Land in the
Netherlands—Marine Deposits on the Coast of Netherlands—Draining of
Lake of Haarlem—Draining of the Zuiderzee—Geographical Effects of
Improvements in the Netherlands—Ancient Hydraulic Works—Draining of
Lake Celano by Prince Torlonia—Incidental Consequences of draining
Lakes—Draining of Marshes—Agricultural Draining—Meteorological
Effects of Draining—Geographical Effects of Draining—Geographical
Effects of Aqueducts and Canals—Antiquity of Irrigation—Irrigation in
Palestine, India, and Egypt—Irrigation in Europe—Meteorological
Effects of Irrigation—Water withdrawn from Rivers for
Irrigation—Injurious Effects of Rice-culture—Salts Deposited by Water
of Irrigation—Subterranean Waters—Artesian Wells—Artificial
Springs—Economizing Precipitation—Inundations in France—Basins of
Reception—Diversion of Rivers—Glacier Lakes—River Embankments—
Page 504
Other
Remedies against Inundations—Dikes of the Nile—Deposits of Tuscan
Rivers—Improvements in Tuscan Maremma—Improvements in Val di
Chiana—Coast of the Netherlands.
Land artificially won from the Waters.
Man, as we have seen, has done much to revolutionize the solid surface
of the globe, and to change the distribution and proportions, if not the
essential character, of the organisms which inhabit the land and even the
waters. Besides the influence thus exerted upon the life which peoples the
sea, his action upon the land has involved a certain amount of indirect
encroachment upon the territorial jurisdiction of the ocean. So far as he has
increased the erosion of running waters by the destruction of the forest or
by other operations which lessen the cohesion of the soil, he has promoted
the deposit of solid matter in the sea, thus reducing the depth of marine
estuaries, advancing the coast-line, and diminishing the area covered by the
waters. He has gone beyond this, and invaded the realm of the ocean by
constructing within its borders wharves, piers, light-houses, breakwaters,
fortresses, and other facilities for his commercial and military operations;
and in some countries he has permanently rescued from tidal overflow, and
even from the very bed of the deep, tracts of ground extensive enough to
constitute valuable additions to his agricultural domain. The quantity of soil
gained from the sea by these different modes of acquisition is, indeed, too
inconsiderable to form an appreciable element in the comparison of the
general proportion between the two great forms of terrestrial surface, land
and water; but the results of such operations, considered in their physical
and their moral bearings, are sufficiently important to entitle them to special
notice in every comprehensive view of the relations between man and
nature.
Remedies against Inundations—Dikes of the Nile—Deposits of Tuscan
Rivers—Improvements in Tuscan Maremma—Improvements in Val di
Chiana—Coast of the Netherlands.
Land artificially won from the Waters.
Man, as we have seen, has done much to revolutionize the solid surface
of the globe, and to change the distribution and proportions, if not the
essential character, of the organisms which inhabit the land and even the
waters. Besides the influence thus exerted upon the life which peoples the
sea, his action upon the land has involved a certain amount of indirect
encroachment upon the territorial jurisdiction of the ocean. So far as he has
increased the erosion of running waters by the destruction of the forest or
by other operations which lessen the cohesion of the soil, he has promoted
the deposit of solid matter in the sea, thus reducing the depth of marine
estuaries, advancing the coast-line, and diminishing the area covered by the
waters. He has gone beyond this, and invaded the realm of the ocean by
constructing within its borders wharves, piers, light-houses, breakwaters,
fortresses, and other facilities for his commercial and military operations;
and in some countries he has permanently rescued from tidal overflow, and
even from the very bed of the deep, tracts of ground extensive enough to
constitute valuable additions to his agricultural domain. The quantity of soil
gained from the sea by these different modes of acquisition is, indeed, too
inconsiderable to form an appreciable element in the comparison of the
general proportion between the two great forms of terrestrial surface, land
and water; but the results of such operations, considered in their physical
and their moral bearings, are sufficiently important to entitle them to special
notice in every comprehensive view of the relations between man and
nature.
Page 505
There are cases, as on the western shores of the Baltic, where, in
consequence of the secular elevation of the coast, the sea appears to be
retiring; others, where, from the slow sinking of the land, it seems to be
advancing. These movements depend upon geological causes wholly out of
our reach, and man can neither advance nor retard them. [Footnote: It is
possible that the weight of the sediment let fall at the mouths of great rivers,
like the Ganges, the Mississippi, and the Po, may cause the depression of
the strata on which they are deposited, and hence if man promotes the
erosion and transport of earthy material by rivers, he augments the weight
of the sediment they convey into their estuaries, and consequently his action
tends to accelerate such depression. There are, however, cases where, in
spite of great deposits of sediment by rivers, the coast is rising. Further, the
manifestation of the internal heat of the earth at any given point is
conditioned by the thickness of the crust at such point. The deposits of
rivers tend to augment that thickness at their estuaries. The sediment of
slowly-flowing rivers emptying into shallow seas is spread over so great a
surface that we can hardly imagine the foot or two of slime they let fall over
a wide area in a century to form an element among even the infinitesimal
quantities which compose the terms of the equations of nature. But some
swift rivers, rolling mountains of fine earth, discharge themselves into
deeply scooped gulfs or bays, and in such cases the deposit amounts, in the
course of a few years, to a mass the transfer of which from the surface of a
large basin, and its accumulation at a single point, may be supposed to
produce other effects than those measurable by the sounding-line. Now,
almost all the operations of rural life, as I have abundantly shown, increase
the liability of the soil to erosion by water. Hence, the clearing of the valley
of the Ganges, for example, by man, must have much augmented the
quantity of earth transported by that river to the sea, and of course have
strengthened the effects, whatever they may be, of thickening the crust of
consequence of the secular elevation of the coast, the sea appears to be
retiring; others, where, from the slow sinking of the land, it seems to be
advancing. These movements depend upon geological causes wholly out of
our reach, and man can neither advance nor retard them. [Footnote: It is
possible that the weight of the sediment let fall at the mouths of great rivers,
like the Ganges, the Mississippi, and the Po, may cause the depression of
the strata on which they are deposited, and hence if man promotes the
erosion and transport of earthy material by rivers, he augments the weight
of the sediment they convey into their estuaries, and consequently his action
tends to accelerate such depression. There are, however, cases where, in
spite of great deposits of sediment by rivers, the coast is rising. Further, the
manifestation of the internal heat of the earth at any given point is
conditioned by the thickness of the crust at such point. The deposits of
rivers tend to augment that thickness at their estuaries. The sediment of
slowly-flowing rivers emptying into shallow seas is spread over so great a
surface that we can hardly imagine the foot or two of slime they let fall over
a wide area in a century to form an element among even the infinitesimal
quantities which compose the terms of the equations of nature. But some
swift rivers, rolling mountains of fine earth, discharge themselves into
deeply scooped gulfs or bays, and in such cases the deposit amounts, in the
course of a few years, to a mass the transfer of which from the surface of a
large basin, and its accumulation at a single point, may be supposed to
produce other effects than those measurable by the sounding-line. Now,
almost all the operations of rural life, as I have abundantly shown, increase
the liability of the soil to erosion by water. Hence, the clearing of the valley
of the Ganges, for example, by man, must have much augmented the
quantity of earth transported by that river to the sea, and of course have
strengthened the effects, whatever they may be, of thickening the crust of
Page 506
the earth in the Bay of Bengal. In such cases, then, human action must rank
among geological influences.
To the geological effects of the thickening of the earth's crust in the Bay
of Bengal, are to be added those of thinning it on the highlands where the
Ganges rises. The same action may, as a learned friend suggests to me, even
have a cosmical influence. The great rivers of the earth, taken as a whole,
transport sediment from the polar regions in an equatorial direction, and
hence tend to increase the equatorial diameter, and at the same time, by
their inequality of action, to a continual displacement of the centre of
gravity, of the earth. The motion of the globe, and of all bodies affected by
its attraction, is modified by every change of its form, and in this case we
are not authorized to say that such effects are in any way compensated.]
There are also cases where similar apparent effects are produced by local
oceanic currents, by river deposit or erosion, by tidal action, or by the
influence of the wind upon the waves and the sands of the seabeach. A
regular current may drift suspended earth and seaweed along a coast until
they are caught by an eddy and finally deposited out of the reach of further
disturbance, or it may scoop out the bed of the sea and undermine
promontories and headlands; a powerful river, as the wind changes the
direction of its flow at its outlet, may wash away shores and sandbanks at
one point to deposit their material at another; the tide or waves, stirred to
unusual depths by the wind, may gradually wear down the line of coast, or
they may form shoals and coast-dunes by depositing the sand they have
rolled up from the bottom of the ocean. These latter modes of action are
slow in producing effects sufficiently important to be noticed in general
geography, or even to be visible in the representations of coast-line laid
down in ordinary maps; but they nevertheless form conspicuous features in
local topography, and they are attended with consequences of great moment
to the material and the moral interests of men. The forces which produce
among geological influences.
To the geological effects of the thickening of the earth's crust in the Bay
of Bengal, are to be added those of thinning it on the highlands where the
Ganges rises. The same action may, as a learned friend suggests to me, even
have a cosmical influence. The great rivers of the earth, taken as a whole,
transport sediment from the polar regions in an equatorial direction, and
hence tend to increase the equatorial diameter, and at the same time, by
their inequality of action, to a continual displacement of the centre of
gravity, of the earth. The motion of the globe, and of all bodies affected by
its attraction, is modified by every change of its form, and in this case we
are not authorized to say that such effects are in any way compensated.]
There are also cases where similar apparent effects are produced by local
oceanic currents, by river deposit or erosion, by tidal action, or by the
influence of the wind upon the waves and the sands of the seabeach. A
regular current may drift suspended earth and seaweed along a coast until
they are caught by an eddy and finally deposited out of the reach of further
disturbance, or it may scoop out the bed of the sea and undermine
promontories and headlands; a powerful river, as the wind changes the
direction of its flow at its outlet, may wash away shores and sandbanks at
one point to deposit their material at another; the tide or waves, stirred to
unusual depths by the wind, may gradually wear down the line of coast, or
they may form shoals and coast-dunes by depositing the sand they have
rolled up from the bottom of the ocean. These latter modes of action are
slow in producing effects sufficiently important to be noticed in general
geography, or even to be visible in the representations of coast-line laid
down in ordinary maps; but they nevertheless form conspicuous features in
local topography, and they are attended with consequences of great moment
to the material and the moral interests of men. The forces which produce
Page 507
these limited results are all in a considerable degree subject to control, or
rather to direction and resistance, by human power, and it is in guiding,
combating, and compensating them that man has achieved some of his most
remarkable and most honorable conquests over nature. The triumphs in
question, or what we generally call harbor and coast improvements,
whether we estimate their value by the money and labor expended upon
them, or by their bearing upon the interests of commerce and the arts of
civilization, must take a very high rank among the great works of man, and
they are fast assuming a magnitude greatly exceeding their former relative
importance.
The extension of commerce and of the military marine, and especially the
introduction of vessels of increased burden and deeper draught of water,
have imposed upon engineers tasks of a character which a century ago
would have been pronounced, and, in fact, would have been, impracticable;
but necessity has stimulated au ingenuity which has contrived means of
executing them, and which gives promise of yet greater performance in
time to come.
Indeed, although man, detached from the solid earth, is almost powerless
to struggle against the sea, he is fast becoming invincible by it so long as
his foot is planted on the shore, or even on the bottom of the rolling ocean;
and though on some battle-fields between the waters and the land he is
obliged slowly to yield his ground, yet he retreats still facing the foe, and
will finally be able to say to the sea, "Thus far shalt thou come and no
farther, and here shall thy proud waves be stayed!" [Footnote: It is,
nevertheless, remarkable that in the particular branch of coast engineering
where great improvements are most urgently needed, comparatively little
has been accomplished. I refer to the creation of artificial harbors, and of
facilities for loading and discharging ships. The whole coast of Italy is, one
may almost say, harborless and even, wharfless, and there are many
rather to direction and resistance, by human power, and it is in guiding,
combating, and compensating them that man has achieved some of his most
remarkable and most honorable conquests over nature. The triumphs in
question, or what we generally call harbor and coast improvements,
whether we estimate their value by the money and labor expended upon
them, or by their bearing upon the interests of commerce and the arts of
civilization, must take a very high rank among the great works of man, and
they are fast assuming a magnitude greatly exceeding their former relative
importance.
The extension of commerce and of the military marine, and especially the
introduction of vessels of increased burden and deeper draught of water,
have imposed upon engineers tasks of a character which a century ago
would have been pronounced, and, in fact, would have been, impracticable;
but necessity has stimulated au ingenuity which has contrived means of
executing them, and which gives promise of yet greater performance in
time to come.
Indeed, although man, detached from the solid earth, is almost powerless
to struggle against the sea, he is fast becoming invincible by it so long as
his foot is planted on the shore, or even on the bottom of the rolling ocean;
and though on some battle-fields between the waters and the land he is
obliged slowly to yield his ground, yet he retreats still facing the foe, and
will finally be able to say to the sea, "Thus far shalt thou come and no
farther, and here shall thy proud waves be stayed!" [Footnote: It is,
nevertheless, remarkable that in the particular branch of coast engineering
where great improvements are most urgently needed, comparatively little
has been accomplished. I refer to the creation of artificial harbors, and of
facilities for loading and discharging ships. The whole coast of Italy is, one
may almost say, harborless and even, wharfless, and there are many
Page 508
thousands of miles of coast in rich commercial countries in Europe, where
vessels can neither lie in safety for a single day, nor even, in better protected
heavens, ship or land their passengers or cargoes except by the help of
lighters, and other not less clumsy contrivances. It is strange that such
enormous inconveniences are borne with so little effort to remove them, and
especially that break-waters are rarely constructed by Governments except
for the benefit of the military marine.]
Great Works of Material Improvement.
Men have ceased to admire the vain exercise of power which heaped up
the great pyramid to gratify the pride of a despot with a giant sepulchre; for
many great harbors, many important lines of internal communication, in the
civilized world, now exhibit works which in volume and weight of material
surpass the vastest remains of ancient architectural art, and demand the
exercise of far greater constructive skill and involve a much heavier
pecuniary expenditure than would now be required for the building of the
tomb of Cheops. It is computed that the great pyramid, the solid contents of
which when complete were about 3,000,000 cubic yards, could be erected
for a million of pounds sterling. The breakwater at Cherbourg, founded in
rough water sixty feet deep, at an average distance of more than two miles
from the shore, contains double the mass of the pyramid, and many a
comparatively unimportant canal has been constructed at twice the cost
which would now build that stupendous monument.
The description of works of harbor and coast improvement which have
only an economical value, not a true geographical importance, does not
come within the plan of the present volume, and in treating this branch of
my subject, I shall confine myself to such as are designed either to gain new
soil by excluding the waters from grounds which they had permanently or
occasionally covered, or to resist new encroachments of the sea upon the
vessels can neither lie in safety for a single day, nor even, in better protected
heavens, ship or land their passengers or cargoes except by the help of
lighters, and other not less clumsy contrivances. It is strange that such
enormous inconveniences are borne with so little effort to remove them, and
especially that break-waters are rarely constructed by Governments except
for the benefit of the military marine.]
Great Works of Material Improvement.
Men have ceased to admire the vain exercise of power which heaped up
the great pyramid to gratify the pride of a despot with a giant sepulchre; for
many great harbors, many important lines of internal communication, in the
civilized world, now exhibit works which in volume and weight of material
surpass the vastest remains of ancient architectural art, and demand the
exercise of far greater constructive skill and involve a much heavier
pecuniary expenditure than would now be required for the building of the
tomb of Cheops. It is computed that the great pyramid, the solid contents of
which when complete were about 3,000,000 cubic yards, could be erected
for a million of pounds sterling. The breakwater at Cherbourg, founded in
rough water sixty feet deep, at an average distance of more than two miles
from the shore, contains double the mass of the pyramid, and many a
comparatively unimportant canal has been constructed at twice the cost
which would now build that stupendous monument.
The description of works of harbor and coast improvement which have
only an economical value, not a true geographical importance, does not
come within the plan of the present volume, and in treating this branch of
my subject, I shall confine myself to such as are designed either to gain new
soil by excluding the waters from grounds which they had permanently or
occasionally covered, or to resist new encroachments of the sea upon the
Page 509
land. [Footnote: Some notice of great works executed by man in foreign
lands, and probably not generally familiar to my readers, may, however,
prove not uninteresting.
The desaguadero, or canal constructed by the Viceroy Revillagigedo to
prevent the inundation of the city of Mexico by the lakes in its vicinity,
besides subsidiary works of great extent, has a cutting half a mile long,
1,000 feet wide, and from 150 to 200 feet deep.—Hoffmann,
Encyclopaedie, art. Mexico.
The adit which drains the mines of Gwennap in Cornwall, with its
branches, is thirty miles long. Those of the silver mines of Saxony are
scarcely less extensive, and the Ernst-August-Stollen, or great drain of the
mines of the Harz, is fifteen miles long.
The excavation for the Suez Canal were computed at 75,000,000 cubic
metres, or about 100,000,000 cubic yards, and those of the Ganges Canal,
which, with its branches, had a length of 3,000 miles, amount to nearly the
same quantity.
The quarries at Maestricht have undermined a space of sixteen miles by
six, or more than two American townships, and the catacombs of Rome, in
part, at least, originally quarries, have a lineal extent of five hundred and
fifty miles. The catacombs of Paris required the excavation of 13,000,000
cubic yards of stone, or more than four times the volume of the great
pyramid.
The excavation for the Mt. Cenis tunnel, eight miles in length, wholly
through solid rock, amounted to more than 900,000 cubic yards, and
16,000,000 of brick were employed for the lining.
lands, and probably not generally familiar to my readers, may, however,
prove not uninteresting.
The desaguadero, or canal constructed by the Viceroy Revillagigedo to
prevent the inundation of the city of Mexico by the lakes in its vicinity,
besides subsidiary works of great extent, has a cutting half a mile long,
1,000 feet wide, and from 150 to 200 feet deep.—Hoffmann,
Encyclopaedie, art. Mexico.
The adit which drains the mines of Gwennap in Cornwall, with its
branches, is thirty miles long. Those of the silver mines of Saxony are
scarcely less extensive, and the Ernst-August-Stollen, or great drain of the
mines of the Harz, is fifteen miles long.
The excavation for the Suez Canal were computed at 75,000,000 cubic
metres, or about 100,000,000 cubic yards, and those of the Ganges Canal,
which, with its branches, had a length of 3,000 miles, amount to nearly the
same quantity.
The quarries at Maestricht have undermined a space of sixteen miles by
six, or more than two American townships, and the catacombs of Rome, in
part, at least, originally quarries, have a lineal extent of five hundred and
fifty miles. The catacombs of Paris required the excavation of 13,000,000
cubic yards of stone, or more than four times the volume of the great
pyramid.
The excavation for the Mt. Cenis tunnel, eight miles in length, wholly
through solid rock, amounted to more than 900,000 cubic yards, and
16,000,000 of brick were employed for the lining.
Page 510
In an article on recent internal improvements in England, in the London
Quarterly Review for January, 1858, it is stated that in a single rock-cutting
on the Liverpool and Manchester railway, 480,000 cubic yards of stone
were removed; that the earth excavated in the construction of English
railways up to that date amounted to a hundred and fifty million cubic
yards, and that at the Round Down Cliff, near Dover, a single blast of
nineteen thousand pounds of powder blew down a thousand million tons of
chalk, and covered fifteen acres of land with the fragments.
In 1869, a mass of marble equal to one and a half times the cubical
contents of the Duomo at Florence, or about 450,000 cubic yards, was
thrown down at Carrara by one blast, and two hours after, another equal
mass, which had been loosened by the explosion, fell of itself. Zolfanelli,
La Lunigiana, p. 43.
The coal yearly extracted from the mines of England averages not less
than 100,000,000 tons. The specific gravity of British coal ranges from 1.20
to 1.35, and consequently we may allow a cubic yard to the ton. If we add
the earth and rock removed in order to reach the coal, we shall have a
yearly amount of excavation for this one object equal to more than thirty
times the volume of the pyramid of Cheops. These are wonderful
achievements of human industry; but the rebuilding of Chicago within a
single year after the great fire—not to speak of the extraordinary material
improvements previously executed at that city—surpasses them all, and it
probably involved the expenditure of a sum of muscular and of moral
energy which has never before been exerted in the accomplishment of a
single material object, within a like period.]
Draining of Lincolnshire Fens.
Quarterly Review for January, 1858, it is stated that in a single rock-cutting
on the Liverpool and Manchester railway, 480,000 cubic yards of stone
were removed; that the earth excavated in the construction of English
railways up to that date amounted to a hundred and fifty million cubic
yards, and that at the Round Down Cliff, near Dover, a single blast of
nineteen thousand pounds of powder blew down a thousand million tons of
chalk, and covered fifteen acres of land with the fragments.
In 1869, a mass of marble equal to one and a half times the cubical
contents of the Duomo at Florence, or about 450,000 cubic yards, was
thrown down at Carrara by one blast, and two hours after, another equal
mass, which had been loosened by the explosion, fell of itself. Zolfanelli,
La Lunigiana, p. 43.
The coal yearly extracted from the mines of England averages not less
than 100,000,000 tons. The specific gravity of British coal ranges from 1.20
to 1.35, and consequently we may allow a cubic yard to the ton. If we add
the earth and rock removed in order to reach the coal, we shall have a
yearly amount of excavation for this one object equal to more than thirty
times the volume of the pyramid of Cheops. These are wonderful
achievements of human industry; but the rebuilding of Chicago within a
single year after the great fire—not to speak of the extraordinary material
improvements previously executed at that city—surpasses them all, and it
probably involved the expenditure of a sum of muscular and of moral
energy which has never before been exerted in the accomplishment of a
single material object, within a like period.]
Draining of Lincolnshire Fens.
Page 511
The draining of the Lincolnshire fens in England, which has converted
about 400,000 acres of marsh, pool, and tide-washed flat into ploughland
and pasturage, is a work, or rather series of works, of great magnitude, and
it possesses much economical, and, indeed, no trifling geographical,
importance. Its plans and methods were, at least in part, borrowed from the
example of like improvements in Holland, and it is, in difficulty and extent,
inferior to works executed for the same purpose on the opposite coast of the
North Sea, by Dutch, Frisie, and Low German engineers. The space I can
devote to such operations will be better employed in describing the latter,
and I content myself with the simple statement I have already made of the
quantity of worthless and even pestilential land which has been rendered
both productive and salubrious in Lincolnshire, by diking out the sea, and
the rivers which traverse the fens of that country.
The almost continued prevalence of west winds upon both coasts of the
German Ocean occasions a constant set of the currents of that sea to the
east, and both for this reason and on account of the greater violence of
storms from the former quarter, the English shores of the North Sea are less
exposed to invasion by the waves than those of the Netherlands and the
provinces contiguous to them on the north. The old Netherlandish
chronicles are filled with the most startling accounts of the damage done by
the irruptions of the ocean, from west winds or extraordinarily high tides, at
times long before any considerable extent of seacoast was diked. Several
hundreds of those terrible inundations are recorded, and in many of them
the loss of human lives is estimated as high as one hundred thousand. It is
impossible to doubt that there must be enormous exaggeration in these
numbers; for, with all the reckless hardihood shown by men in braving the
dangers and privations attached by nature to their birthplace, it is
inconceivable that so dense a population as such wholesale destruction of
life supposes could find the means of subsistence, or content itself to dwell,
on a territory liable, a dozen times in a century, to such fearful devastation.
about 400,000 acres of marsh, pool, and tide-washed flat into ploughland
and pasturage, is a work, or rather series of works, of great magnitude, and
it possesses much economical, and, indeed, no trifling geographical,
importance. Its plans and methods were, at least in part, borrowed from the
example of like improvements in Holland, and it is, in difficulty and extent,
inferior to works executed for the same purpose on the opposite coast of the
North Sea, by Dutch, Frisie, and Low German engineers. The space I can
devote to such operations will be better employed in describing the latter,
and I content myself with the simple statement I have already made of the
quantity of worthless and even pestilential land which has been rendered
both productive and salubrious in Lincolnshire, by diking out the sea, and
the rivers which traverse the fens of that country.
The almost continued prevalence of west winds upon both coasts of the
German Ocean occasions a constant set of the currents of that sea to the
east, and both for this reason and on account of the greater violence of
storms from the former quarter, the English shores of the North Sea are less
exposed to invasion by the waves than those of the Netherlands and the
provinces contiguous to them on the north. The old Netherlandish
chronicles are filled with the most startling accounts of the damage done by
the irruptions of the ocean, from west winds or extraordinarily high tides, at
times long before any considerable extent of seacoast was diked. Several
hundreds of those terrible inundations are recorded, and in many of them
the loss of human lives is estimated as high as one hundred thousand. It is
impossible to doubt that there must be enormous exaggeration in these
numbers; for, with all the reckless hardihood shown by men in braving the
dangers and privations attached by nature to their birthplace, it is
inconceivable that so dense a population as such wholesale destruction of
life supposes could find the means of subsistence, or content itself to dwell,
on a territory liable, a dozen times in a century, to such fearful devastation.
Page 512
There can be no doubt, however, that the low continental shores of the
German Ocean very frequently suffered immense injury from inundation by
the sea, and it is natural, therefore, that the various arts of resistance to the
encroachments of the ocean, and, finally, of aggressive warfare upon its
domain, and of permanent conquest of its territory, should have been earlier
studied and carried to higher perfection in the latter countries, than in
England, which had less to lose or to gain by the incursions or the retreat of
the waters.
Indeed, although the confinement of swelling rivers by artificial
embankments is of great antiquity, I do not know that the defence or
acquisition of land from the sea by diking was ever practised on a large
scale until systematically undertaken by the Netherlanders, a few centuries
after the commencement of the Christian era. The silence of the Roman
historians affords a strong presumption that this art was unknown to the
inhabitants of the Netherlands at the time of the Roman invasion, and the
elder Pliny's description of the mode of life along the coast which has now
been long diked in, applies precisely to the habits of the people who live on
the low islands and mainland flats lying outside of the chain of dikes, and
wholly unprotected by embankments of any sort.
Origin of Sea-dikes.
It has been conjectured, and not without probability, that the causeways
built by the Romans across the marshes of the Low Countries, in their
campaigns against the Germanic tribes, gave the natives the first hint of the
utility which might be derived from similar constructions applied to a
different purpose. [Footnote: It has often been alleged by eminent writers
that a part of the fens in Lincolnshire was reclaimed by sea-dikes under the
government of the Romans. I have found no ancient authority in support of
this assertion, nor can I refer to any passage in Roman literature in which
German Ocean very frequently suffered immense injury from inundation by
the sea, and it is natural, therefore, that the various arts of resistance to the
encroachments of the ocean, and, finally, of aggressive warfare upon its
domain, and of permanent conquest of its territory, should have been earlier
studied and carried to higher perfection in the latter countries, than in
England, which had less to lose or to gain by the incursions or the retreat of
the waters.
Indeed, although the confinement of swelling rivers by artificial
embankments is of great antiquity, I do not know that the defence or
acquisition of land from the sea by diking was ever practised on a large
scale until systematically undertaken by the Netherlanders, a few centuries
after the commencement of the Christian era. The silence of the Roman
historians affords a strong presumption that this art was unknown to the
inhabitants of the Netherlands at the time of the Roman invasion, and the
elder Pliny's description of the mode of life along the coast which has now
been long diked in, applies precisely to the habits of the people who live on
the low islands and mainland flats lying outside of the chain of dikes, and
wholly unprotected by embankments of any sort.
Origin of Sea-dikes.
It has been conjectured, and not without probability, that the causeways
built by the Romans across the marshes of the Low Countries, in their
campaigns against the Germanic tribes, gave the natives the first hint of the
utility which might be derived from similar constructions applied to a
different purpose. [Footnote: It has often been alleged by eminent writers
that a part of the fens in Lincolnshire was reclaimed by sea-dikes under the
government of the Romans. I have found no ancient authority in support of
this assertion, nor can I refer to any passage in Roman literature in which
Page 513
sea-dikes are expressly mentioned otherwise than as walls or piers, except
that in Pliny (Hist. Nat. xxxvi. 24), where it is said that the Tyrrhenian Sea
was excluded from the Lucrino Lake by dikes. Dugdale, whose enthusiasm
for his subject led him to believe that recovering from the sea land subject
to be flooded by it, was of divine appointment, because God said: "Let the
waters under the heavens be gathered together unto one place and let the
dry land appear," unhesitatingly ascribes the reclamation of the Lincolnshire
fens to the Romans, though he is able to cite but one authority, a passage in
Tacitus's Life of Agricola which certainly has no such meaning, in support
of the assertion.—History of Embankment and Drainage, 2d edition, 1772.]
If this is so, it is one of the most interesting among the many instances in
which the arts and enginery of war have been so modified as to be
eminently promotive of the blessings of peace, thereby in some measure
compensating the wrongs and sufferings they have inflicted on humanity.
[Footnote: It is worth mentioning, as an illustration of the applicability of
military instrumentalities to pacific art, that the sale of gunpowder in the
United States was smaller during the late rebellion than before, because the
war caused the suspension of many public and private improvements, in the
execution of which great quantities of powder were used for blasting.
The same observation was made in France during the Crimean war, and it
is alleged that, in general, not ten per cent. of the powder manufactured on
either either side of the Atlantic is employed for military purposes.
The blasting for the Mount Cenis tunnel consumed gunpowder enough to
fill more than 200,000,000 musket cartridges. It is a fact not creditable to
the moral sense of modern civilization, that very many of the most
important improvements in machinery and the working of metals have
originated in the necessities of war, and that man's highest ingenuity has
been shown, and many of his most remarkable triumphs over natural forces
achieved, in the contrivance of engines for the destruction of his fellow-
that in Pliny (Hist. Nat. xxxvi. 24), where it is said that the Tyrrhenian Sea
was excluded from the Lucrino Lake by dikes. Dugdale, whose enthusiasm
for his subject led him to believe that recovering from the sea land subject
to be flooded by it, was of divine appointment, because God said: "Let the
waters under the heavens be gathered together unto one place and let the
dry land appear," unhesitatingly ascribes the reclamation of the Lincolnshire
fens to the Romans, though he is able to cite but one authority, a passage in
Tacitus's Life of Agricola which certainly has no such meaning, in support
of the assertion.—History of Embankment and Drainage, 2d edition, 1772.]
If this is so, it is one of the most interesting among the many instances in
which the arts and enginery of war have been so modified as to be
eminently promotive of the blessings of peace, thereby in some measure
compensating the wrongs and sufferings they have inflicted on humanity.
[Footnote: It is worth mentioning, as an illustration of the applicability of
military instrumentalities to pacific art, that the sale of gunpowder in the
United States was smaller during the late rebellion than before, because the
war caused the suspension of many public and private improvements, in the
execution of which great quantities of powder were used for blasting.
The same observation was made in France during the Crimean war, and it
is alleged that, in general, not ten per cent. of the powder manufactured on
either either side of the Atlantic is employed for military purposes.
The blasting for the Mount Cenis tunnel consumed gunpowder enough to
fill more than 200,000,000 musket cartridges. It is a fact not creditable to
the moral sense of modern civilization, that very many of the most
important improvements in machinery and the working of metals have
originated in the necessities of war, and that man's highest ingenuity has
been shown, and many of his most remarkable triumphs over natural forces
achieved, in the contrivance of engines for the destruction of his fellow-
Page 514
man. The military material employed by the first Napoleon has become, in
less than two generations, nearly as obsolete as the sling and stone of the
shepherd, and attack and defence now begin at distances to which, half a
century ago, military reconnaissances hardly extended. Upon a partial view
of the subject, the human race seems destined to become its own
executioner—on the one hand, exhausting the capacity of the earth to
furnish sustenance to her taskmaster; on the other, compensating diminished
production by inventing more efficient methods of exterminating the
consumer. At the present moment, at an epoch of universal peace, the whole
civilized world with the happy exception of our own country, is devoting its
utmost energies, applying the highest exercise of inventive genius, to the
production of new engines of war; and the last extraordinary rise in the
price of iron and copper is in great part due to the consumption of these
metals in the fabrication of arms and armed vessels. The simple substitution
of sheet-copper for paper and other materials in the manufacture of
cartridges has increased the market-price of copper by a large percentage on
its former cost.
But war develops great civil virtues, and brings into action a degree and
kind of physical energy which seldom fails to awaken a new intellectual life
in a people that achieves great moral and political results through great
heroism and endurance and perseverance. Domestic corruption has
destroyed more nations than foreign invasion, and a people is rarely
conquered till it has deserved subjugation.] The Lowlanders are believed to
have secured some coast and bay islands by ring-dikes and to have
embanked some fresh-water channels, as early as the eighth or ninth
century; but it does not appear that sea-dikes, important enough to be
noticed in historical records, were constructed on the mainland before the
thirteenth century. The practice of draining inland accumulations of water,
whether fresh or salt, for the purpose of bringing under cultivation the
ground they cover, is of later origin, and is said not to have been adopted
less than two generations, nearly as obsolete as the sling and stone of the
shepherd, and attack and defence now begin at distances to which, half a
century ago, military reconnaissances hardly extended. Upon a partial view
of the subject, the human race seems destined to become its own
executioner—on the one hand, exhausting the capacity of the earth to
furnish sustenance to her taskmaster; on the other, compensating diminished
production by inventing more efficient methods of exterminating the
consumer. At the present moment, at an epoch of universal peace, the whole
civilized world with the happy exception of our own country, is devoting its
utmost energies, applying the highest exercise of inventive genius, to the
production of new engines of war; and the last extraordinary rise in the
price of iron and copper is in great part due to the consumption of these
metals in the fabrication of arms and armed vessels. The simple substitution
of sheet-copper for paper and other materials in the manufacture of
cartridges has increased the market-price of copper by a large percentage on
its former cost.
But war develops great civil virtues, and brings into action a degree and
kind of physical energy which seldom fails to awaken a new intellectual life
in a people that achieves great moral and political results through great
heroism and endurance and perseverance. Domestic corruption has
destroyed more nations than foreign invasion, and a people is rarely
conquered till it has deserved subjugation.] The Lowlanders are believed to
have secured some coast and bay islands by ring-dikes and to have
embanked some fresh-water channels, as early as the eighth or ninth
century; but it does not appear that sea-dikes, important enough to be
noticed in historical records, were constructed on the mainland before the
thirteenth century. The practice of draining inland accumulations of water,
whether fresh or salt, for the purpose of bringing under cultivation the
ground they cover, is of later origin, and is said not to have been adopted
Page 515
until after the middle of the fifteenth century. [Footnote: Staring, Voormaals
en Thans, p. 150.]
Gain and Loss of Land in the Netherlands.
The total amount of surface gained to the agriculture of the Netherlands
by diking out the sea and by draining shallow bays and lakes, is estimated
by Staring at three hundred and fifty-five thousand bunder or hectares,
equal to eight hundred and seventy-seven thousand two hundred and forty
acres, which is one-tenth of the area of the kingdom. [Footnote: Idem, p.
163. Much the largest proportion of the lands so reclaimed, though for the
most part lying above low-water tidemark, are at a lower level than the
Lincolnshire fens, and more subject to inundation from the irruptions of the
sea.] In very many instances the dikes have been partially, in some
particularly exposed localities totally, destroyed by the violence of the sea,
and the drained lands again flooded. In some cases the soil thus painfully
won from the ocean has been entirely lost; in others it has been recovered
by repairing or rebuilding the dikes and pumping out the water. Besides
this, the weight of the dikes gradually sinks them into the soft soil beneath,
and this loss of elevation must be compensated by raising the surface, while
the increased burden thus added tends to sink them still lower. "Tetens
declares," says Kohl, "that in some places the dikes have gradually sunk to
the depth of sixty or even a hundred feet." [Footnote: Die Inseln und
Marschen der Herzogthamer Schleswig und Holstein, iii., p. 151.] For these
reasons, the processes of dike-building have been almost everywhere again
and again repeated, and thus the total expenditure of money and of labor
upon the works in question is much greater than would appear from an
estimate of the actual cost of diking-in a given extent of coast-land and
draining a given area of water-surface. [Footnote: The purely agricultural
island of Pelworm, off the coast of Schleswig, containing about 10,000
en Thans, p. 150.]
Gain and Loss of Land in the Netherlands.
The total amount of surface gained to the agriculture of the Netherlands
by diking out the sea and by draining shallow bays and lakes, is estimated
by Staring at three hundred and fifty-five thousand bunder or hectares,
equal to eight hundred and seventy-seven thousand two hundred and forty
acres, which is one-tenth of the area of the kingdom. [Footnote: Idem, p.
163. Much the largest proportion of the lands so reclaimed, though for the
most part lying above low-water tidemark, are at a lower level than the
Lincolnshire fens, and more subject to inundation from the irruptions of the
sea.] In very many instances the dikes have been partially, in some
particularly exposed localities totally, destroyed by the violence of the sea,
and the drained lands again flooded. In some cases the soil thus painfully
won from the ocean has been entirely lost; in others it has been recovered
by repairing or rebuilding the dikes and pumping out the water. Besides
this, the weight of the dikes gradually sinks them into the soft soil beneath,
and this loss of elevation must be compensated by raising the surface, while
the increased burden thus added tends to sink them still lower. "Tetens
declares," says Kohl, "that in some places the dikes have gradually sunk to
the depth of sixty or even a hundred feet." [Footnote: Die Inseln und
Marschen der Herzogthamer Schleswig und Holstein, iii., p. 151.] For these
reasons, the processes of dike-building have been almost everywhere again
and again repeated, and thus the total expenditure of money and of labor
upon the works in question is much greater than would appear from an
estimate of the actual cost of diking-in a given extent of coast-land and
draining a given area of water-surface. [Footnote: The purely agricultural
island of Pelworm, off the coast of Schleswig, containing about 10,000
Page 516
acres, annually expends for the maintenance of its dikes not less than
L6,000 sterling, or nearly $30,000.—J. G. Kohl, Inseln und Marschen
Schleswig's und Holstein's, ii., p. 394.
The original cost of the dikes of Pelworm is not stated. "The greatest part
of the province of Zeeland is protected by dikes measuring 250 miles in
length, the maintenance of which costs, in ordinary years, more than a
million guilders [above $400,000] … The annual expenditure for dikes and
hydraulic works in Holland is from five to seven million guilders"
[$2,000,000 to $2,800,000].—Wild, Die Niederlande, i., p. 62.
One is not sorry to learn that the Spanish tyranny in the Netherlands had
some compensations. The great chain of ring-dikes which surrounds a large
part of Zeeland is due to the energy of Caspar de Robles, the Spanish
governor of that province, who in 1570 ordered the construction of these
works at the public expense, as a substitute for the private embankments
which had previously partially served the same purpose.—Wild, Die
Niederlande, i., p. 62.]
Loss of Land by Incursions of Sea.
On the other hand, by erosion of the coast-line, the drifting of sand-dunes
into the interior, and the drowning of fens and morasses by incursions of the
sea—all caused, or at least greatly aggravated, by human improvidence—
the Netherlands have lost a far larger area of land since the commencement
of the Christian era than they have gained by diking and draining. Staring
despairs of the possibility of calculating the loss from the first-mentioned
two causes of destruction, but he estimates that not less than six hundred
and forty thousand bunder, or one million five hundred and eighty-one
thousand acres, of fen and marsh have been washed away, or rather
deprived of their vegetable surface and covered by water; and thirty-seven
L6,000 sterling, or nearly $30,000.—J. G. Kohl, Inseln und Marschen
Schleswig's und Holstein's, ii., p. 394.
The original cost of the dikes of Pelworm is not stated. "The greatest part
of the province of Zeeland is protected by dikes measuring 250 miles in
length, the maintenance of which costs, in ordinary years, more than a
million guilders [above $400,000] … The annual expenditure for dikes and
hydraulic works in Holland is from five to seven million guilders"
[$2,000,000 to $2,800,000].—Wild, Die Niederlande, i., p. 62.
One is not sorry to learn that the Spanish tyranny in the Netherlands had
some compensations. The great chain of ring-dikes which surrounds a large
part of Zeeland is due to the energy of Caspar de Robles, the Spanish
governor of that province, who in 1570 ordered the construction of these
works at the public expense, as a substitute for the private embankments
which had previously partially served the same purpose.—Wild, Die
Niederlande, i., p. 62.]
Loss of Land by Incursions of Sea.
On the other hand, by erosion of the coast-line, the drifting of sand-dunes
into the interior, and the drowning of fens and morasses by incursions of the
sea—all caused, or at least greatly aggravated, by human improvidence—
the Netherlands have lost a far larger area of land since the commencement
of the Christian era than they have gained by diking and draining. Staring
despairs of the possibility of calculating the loss from the first-mentioned
two causes of destruction, but he estimates that not less than six hundred
and forty thousand bunder, or one million five hundred and eighty-one
thousand acres, of fen and marsh have been washed away, or rather
deprived of their vegetable surface and covered by water; and thirty-seven
Page 517
thousand bunder, or ninety-one thousand four hundred acres, of recovered
land, have been lost by the destruction of the dikes which protected them.
[Footnote: Staring, Voormaals en Thans, p. 163.] The average value of land
gained from the sea is estimated at about nineteen pounds sterling, or ninety
dollars, per acre; while the lost fen and morass was not worth more than one
twenty-fifth part of the same price. The ground buried by the drifting of the
dunes appears to have been almost entirely of this latter character, and,
upon the whole, there is no doubt that the soil added by human industry to
the territory of the Netherlands, within the historical period, greatly exceeds
in pecuniary value that which has fallen a prey to the waves during the
same era.
Upon most low and shelving coasts, like those of the Netherlands, the
maritime currents are constantly changing, in consequence of the variability
of the winds, and the shifting of the sand-banks, which the currents
themselves now form and now displace. While, therefore, at one point the
sea is advancing landward, and requiring great effort to prevent the
undermining and washing away of the dikes, it is shoaling at another by its
own deposits, and exposing, at low water, a gradually widening belt of
sands and ooze. The coast-lands selected for diking-in are always at points
where the sea is depositing productive soil. The Eider, the Elbe, the Weser,
the Ems, the Rhine, the Maas, and the Schelde bring down large quantities
of fine earth. The prevalence of west winds prevents the waters from
carrying this material far out from the coast, and it is at last deposited
northward or southward from the mouth of the rivers which contribute it,
according to the varying drift of the currents.
Marine Deposits.
The process of natural deposit which prepares the coast for diking-in is
thus described by Staring: "All sea-deposited soil is composed of the same
land, have been lost by the destruction of the dikes which protected them.
[Footnote: Staring, Voormaals en Thans, p. 163.] The average value of land
gained from the sea is estimated at about nineteen pounds sterling, or ninety
dollars, per acre; while the lost fen and morass was not worth more than one
twenty-fifth part of the same price. The ground buried by the drifting of the
dunes appears to have been almost entirely of this latter character, and,
upon the whole, there is no doubt that the soil added by human industry to
the territory of the Netherlands, within the historical period, greatly exceeds
in pecuniary value that which has fallen a prey to the waves during the
same era.
Upon most low and shelving coasts, like those of the Netherlands, the
maritime currents are constantly changing, in consequence of the variability
of the winds, and the shifting of the sand-banks, which the currents
themselves now form and now displace. While, therefore, at one point the
sea is advancing landward, and requiring great effort to prevent the
undermining and washing away of the dikes, it is shoaling at another by its
own deposits, and exposing, at low water, a gradually widening belt of
sands and ooze. The coast-lands selected for diking-in are always at points
where the sea is depositing productive soil. The Eider, the Elbe, the Weser,
the Ems, the Rhine, the Maas, and the Schelde bring down large quantities
of fine earth. The prevalence of west winds prevents the waters from
carrying this material far out from the coast, and it is at last deposited
northward or southward from the mouth of the rivers which contribute it,
according to the varying drift of the currents.
Marine Deposits.
The process of natural deposit which prepares the coast for diking-in is
thus described by Staring: "All sea-deposited soil is composed of the same
Page 518
constituents. First comes a stratum of sand, with marine shells, or the shells
of mollusks living in brackish water. If there be tides, and, of course,
flowing and ebbing currents, mud is let fall upon the sand only after the
latter has been raised above low-water mark; for then only, at the change
from flood to ebb, is the water still enough to form a deposit of so light a
material. Where mud is found at great depths, as, for example, in a large
proportion of the Ij, it is a proof that at this point there was never any
considerable tidal flow or other current. … The powerful tidal currents,
flowing and ebbing twice a day, drift sand with them. They scoop out the
bottom at one point, raise it at another, and the sand-banks in the current are
continually shifting. As soon as a bank raises itself above low-water mark,
flags and reeds establish themselves upon it. The mechanical resistance of
these plants checks the retreat of the high water and favors the deposit of
the earth suspended in it, and the formation of land goes on with surprising
rapidity. When it has risen to high-water level, it is soon covered with
grasses, and becomes what is called schor in Zeeland, kwelder in Friesland.
Such grounds are the foundation or starting-point of the process of diking.
When they are once elevated to the flood-tide level, no more mud is
deposited upon them except by extraordinary high tides. Their further rise
is, accordingly, very slow, and it is seldom advantageous to delay longer the
operation of diking." [Footnote: Voormaals en Thans, pp. 150, 151.
According to Reventlov, confercae first appear at the bottom in shoal water,
then, after the deposit has risen above the surface, Salicornia herbacea. The
Salicornia is followed by various sand-plants, and so the ground rises, by
Poa distans and Poa maritum, and finally common grasses establish
themselves.—Om Markdannelsen poa Vestkyeten of Slesvig, pp. 7, 8.]
Sea-dikes of the Netherlands.
of mollusks living in brackish water. If there be tides, and, of course,
flowing and ebbing currents, mud is let fall upon the sand only after the
latter has been raised above low-water mark; for then only, at the change
from flood to ebb, is the water still enough to form a deposit of so light a
material. Where mud is found at great depths, as, for example, in a large
proportion of the Ij, it is a proof that at this point there was never any
considerable tidal flow or other current. … The powerful tidal currents,
flowing and ebbing twice a day, drift sand with them. They scoop out the
bottom at one point, raise it at another, and the sand-banks in the current are
continually shifting. As soon as a bank raises itself above low-water mark,
flags and reeds establish themselves upon it. The mechanical resistance of
these plants checks the retreat of the high water and favors the deposit of
the earth suspended in it, and the formation of land goes on with surprising
rapidity. When it has risen to high-water level, it is soon covered with
grasses, and becomes what is called schor in Zeeland, kwelder in Friesland.
Such grounds are the foundation or starting-point of the process of diking.
When they are once elevated to the flood-tide level, no more mud is
deposited upon them except by extraordinary high tides. Their further rise
is, accordingly, very slow, and it is seldom advantageous to delay longer the
operation of diking." [Footnote: Voormaals en Thans, pp. 150, 151.
According to Reventlov, confercae first appear at the bottom in shoal water,
then, after the deposit has risen above the surface, Salicornia herbacea. The
Salicornia is followed by various sand-plants, and so the ground rises, by
Poa distans and Poa maritum, and finally common grasses establish
themselves.—Om Markdannelsen poa Vestkyeten of Slesvig, pp. 7, 8.]
Sea-dikes of the Netherlands.
Page 519
The formation of new banks by the sea is constantly going on at points
favorable for the deposit of sand and earth, and hence opportunity is
continually afforded for enclosure of new land outside of that already diked
in, the coast is fast advancing seaward, and every new embankment
increases the security of former enclosures. The province of Zeeland
consists of islands washed by the sea on their western coasts, and separated
by the many channels through which the Schelde and some other rivers find
their way to the ocean. In the twelfth century these islands were much
smaller and more numerous than at present. They have been gradually
enlarged, and, in several instances, at last connected by the extension of
their system of dikes. Walcheren is formed of ten islets united into one
about the end of the fourteenth century. At the middle of the fifteenth
century, Goeree and Overflakkee consisted of separate islands, containing
altogether about ten thousand acres; by means of above sixty successive
advances of the dikes, they have been brought to compose a single island,
whose area is not less than sixty thousand acres. [Footnote: Staring,
Voormaals en Thans, p, 152. Kohl states that the peninsula of Diksand on
the coast of Holstein consisted, at the close of the last century, of several
islands measuring together less than five thousand acres. In 1837 they had
been connected with the mainland, and had nearly doubled in area.—Inseln
u. Marschen Schlene, Holst., iii., p. 202]
In the Netherlands—which the first Napoleon characterized as a deposit
of the Rhine, and as, therefore, by natural law, rightfully the property of him
who controlled the sources of that great river—and on the adjacent Frisie,
Low German, and Danish shores and islands, sea and river dikes have been
constructed on a grander and more imposing scale than in any other
country. The whole economy of the art has been there most thoroughly
studied, and the literature of the subject is very extensive. For my present
aim, which is concerned with results rather than with processes, it is not
worth while to refer to professional treatises, and I shall content myself with
favorable for the deposit of sand and earth, and hence opportunity is
continually afforded for enclosure of new land outside of that already diked
in, the coast is fast advancing seaward, and every new embankment
increases the security of former enclosures. The province of Zeeland
consists of islands washed by the sea on their western coasts, and separated
by the many channels through which the Schelde and some other rivers find
their way to the ocean. In the twelfth century these islands were much
smaller and more numerous than at present. They have been gradually
enlarged, and, in several instances, at last connected by the extension of
their system of dikes. Walcheren is formed of ten islets united into one
about the end of the fourteenth century. At the middle of the fifteenth
century, Goeree and Overflakkee consisted of separate islands, containing
altogether about ten thousand acres; by means of above sixty successive
advances of the dikes, they have been brought to compose a single island,
whose area is not less than sixty thousand acres. [Footnote: Staring,
Voormaals en Thans, p, 152. Kohl states that the peninsula of Diksand on
the coast of Holstein consisted, at the close of the last century, of several
islands measuring together less than five thousand acres. In 1837 they had
been connected with the mainland, and had nearly doubled in area.—Inseln
u. Marschen Schlene, Holst., iii., p. 202]
In the Netherlands—which the first Napoleon characterized as a deposit
of the Rhine, and as, therefore, by natural law, rightfully the property of him
who controlled the sources of that great river—and on the adjacent Frisie,
Low German, and Danish shores and islands, sea and river dikes have been
constructed on a grander and more imposing scale than in any other
country. The whole economy of the art has been there most thoroughly
studied, and the literature of the subject is very extensive. For my present
aim, which is concerned with results rather than with processes, it is not
worth while to refer to professional treatises, and I shall content myself with
Page 520
presenting such information as can be gathered from works of a more
popular character.
The superior strata of the lowlands upon and near the coast are, as we
have seen, principally composed of soil brought down by the great rivers I
have mentioned, and either directly deposited by them upon the sands of the
bottom, or carried out to sea by their currents, and then, after a shorter or
longer exposure to the chemical and mechanical action of salt-water and
marine currents, restored again to the land by tidal overflow and subsidence
from the waters in which it was suspended. At a very remote period the
coast-flats were, at many points, raised so high by successive alluvious or
tidal deposits as to be above ordinary high-water level, but they were still
liable to occasional inundation from river-floods, and from the seawater
also, when heavy or long-continued west winds drove it landwards. The
extraordinary fertility of this soil and its security as a retreat from hostile
violence attracted to it a considerable population, while its want of
protection against inundation exposed it to the devastations of which the
chroniclers of the Middle Ages have left such highly colored pictures. The
first permanent dwellings on the coast-flats were erected upon artificial
mounds, and many similar precarious habitations still exist on the unwalled
islands and shores beyond the chain of dikes. River embankments, which,
as is familiarly known, have from the earliest antiquity been employed in
many countries where sea-dikes are unknown, were probably the first works
of this character constructed in the Low Countries, and when two
neighboring streams of fresh water had been embanked, the next step in the
process would naturally be to connect the river-walls together by a
transverse dike or raised causeway, which would serve as a means of
communication between different hamlets and at the same time secure the
intermediate ground both against the backwater of river-floods and against
overflow by the sea. The oldest true sea-dikes described in historical
records, however, are those enclosing islands in the estuaries of the great
popular character.
The superior strata of the lowlands upon and near the coast are, as we
have seen, principally composed of soil brought down by the great rivers I
have mentioned, and either directly deposited by them upon the sands of the
bottom, or carried out to sea by their currents, and then, after a shorter or
longer exposure to the chemical and mechanical action of salt-water and
marine currents, restored again to the land by tidal overflow and subsidence
from the waters in which it was suspended. At a very remote period the
coast-flats were, at many points, raised so high by successive alluvious or
tidal deposits as to be above ordinary high-water level, but they were still
liable to occasional inundation from river-floods, and from the seawater
also, when heavy or long-continued west winds drove it landwards. The
extraordinary fertility of this soil and its security as a retreat from hostile
violence attracted to it a considerable population, while its want of
protection against inundation exposed it to the devastations of which the
chroniclers of the Middle Ages have left such highly colored pictures. The
first permanent dwellings on the coast-flats were erected upon artificial
mounds, and many similar precarious habitations still exist on the unwalled
islands and shores beyond the chain of dikes. River embankments, which,
as is familiarly known, have from the earliest antiquity been employed in
many countries where sea-dikes are unknown, were probably the first works
of this character constructed in the Low Countries, and when two
neighboring streams of fresh water had been embanked, the next step in the
process would naturally be to connect the river-walls together by a
transverse dike or raised causeway, which would serve as a means of
communication between different hamlets and at the same time secure the
intermediate ground both against the backwater of river-floods and against
overflow by the sea. The oldest true sea-dikes described in historical
records, however, are those enclosing islands in the estuaries of the great
Page 521
rivers, and it is not impossible that the double character they possess as a
security against maritime floods and as a military rampart, led to their
adoption upon those islands before similar constructions had been
attempted upon the mainland.
At some points of the coast, various contrivances, such as piers, piles,
and, in fact, obstructions of all sorts to the ebb of the current, are employed
to facilitate the deposit of slime, before a regular enclosure is commenced.
Usually, however, the first step is to build low and cheap embankments,
extending from an older dike, or from high ground, around the parcel of flat
intended to be secured. These are called summer dikes. They are erected
when a sufficient extent of ground to repay the cost has been elevated
enough to be covered with coarse vegetation fit for pasturage. They serve
both to secure the ground from overflow by the ordinary flood-tides of mild
weather, and to retain the slime deposited by very high water, which would
otherwise be partly carried off by the retreating ebb. The elevation of the
soil goes on slowly after this; but when it has at last been sufficiently
enriched, and raised high enough to justify the necessary outlay, permanent
dikes are constructed by which the water is excluded at all seasons. These
embankments are constructed of sand from the coast-dunes or from sand-
banks, and of earth from the mainland or from flats outside the dikes, bound
and strengthened by fascines, and provided with sluices, which are
generally founded on piles and of very expensive construction, for drainage
at low water. The outward slope of the sea-dikes is gentle, experience
having shown that this form is least exposed to injury both from the waves
and from floating ice, and the most modern dikes are even more moderate
in the inclination of the seaward scarp than the older ones. [Footnote: The
inclination varies from one foot rise in four of base to one foot in fourteen.
—Kohl, iii., p. 210.] The crown of the dike, however, for the last three or
four feet of its height, is much steeper, being intended rather as a protection
security against maritime floods and as a military rampart, led to their
adoption upon those islands before similar constructions had been
attempted upon the mainland.
At some points of the coast, various contrivances, such as piers, piles,
and, in fact, obstructions of all sorts to the ebb of the current, are employed
to facilitate the deposit of slime, before a regular enclosure is commenced.
Usually, however, the first step is to build low and cheap embankments,
extending from an older dike, or from high ground, around the parcel of flat
intended to be secured. These are called summer dikes. They are erected
when a sufficient extent of ground to repay the cost has been elevated
enough to be covered with coarse vegetation fit for pasturage. They serve
both to secure the ground from overflow by the ordinary flood-tides of mild
weather, and to retain the slime deposited by very high water, which would
otherwise be partly carried off by the retreating ebb. The elevation of the
soil goes on slowly after this; but when it has at last been sufficiently
enriched, and raised high enough to justify the necessary outlay, permanent
dikes are constructed by which the water is excluded at all seasons. These
embankments are constructed of sand from the coast-dunes or from sand-
banks, and of earth from the mainland or from flats outside the dikes, bound
and strengthened by fascines, and provided with sluices, which are
generally founded on piles and of very expensive construction, for drainage
at low water. The outward slope of the sea-dikes is gentle, experience
having shown that this form is least exposed to injury both from the waves
and from floating ice, and the most modern dikes are even more moderate
in the inclination of the seaward scarp than the older ones. [Footnote: The
inclination varies from one foot rise in four of base to one foot in fourteen.
—Kohl, iii., p. 210.] The crown of the dike, however, for the last three or
four feet of its height, is much steeper, being intended rather as a protection
Page 522
against the spray than against the waves, and the inner slope is always
comparatively abrupt.
The height and thickness of dikes varies according to the elevation of the
ground they enclose, the rise of the tides, the direction of the prevailing
winds, and other special causes of exposure, but it may be said that they are,
in general, raised from fifteen to twenty feet above ordinary high-water
mark. The water-slopes of river-dikes are protected by plantations of
willows or strong semi-aquatic shrubs or grasses, but as these will not grow
upon banks exposed to salt-water, sea-dikes must be faced with stone,
fascines, or some other revetement. [Footnote: The dikes are sometimes
founded upon piles, and sometimes protected by one or more rows of piles
driven deeply down into the bed of the sea in front of them. "Triple rows of
piles of Scandinavian pine," says Wild, "have been driven down along the
coast of Friesland, where there are no dunes, for a distance of one hundred
and fifty miles. The piles are bound together by strong cross-timbers and
iron clamps, and the interstices filled with stones. The ground adjacent to
the piling is secured with fascines, and at exposed points heavy blocks of
stone are heaped up as an additional protection. The earth-dike is built
behind the mighty bulwark of this breakwater, and its foot also is fortified
with stones." … "The great Helder dike is about five miles long and forty
feet wide at the top, along which runs a good road. It slopes down two
hundred feet into the sea, at an angle of forty degrees. The highest waves do
not reach the summit, the lowest always cover its base. At certain distances,
immense buttresses, of a height and width proportioned to those of the dike,
and even more strongly built, run several hundred feet out into the rolling
sea. This gigantic artificial coast is entirely composed of Norwegian
granite."—Wild, Die Niederlande, i., pp. 61, 62.] Upon the coast of
Schleswig and Holstein, where the people have less capital at their
command, they defend their embankments against ice and the waves by a
coating of twisted straw or reeds, which must be renewed as often as once,
comparatively abrupt.
The height and thickness of dikes varies according to the elevation of the
ground they enclose, the rise of the tides, the direction of the prevailing
winds, and other special causes of exposure, but it may be said that they are,
in general, raised from fifteen to twenty feet above ordinary high-water
mark. The water-slopes of river-dikes are protected by plantations of
willows or strong semi-aquatic shrubs or grasses, but as these will not grow
upon banks exposed to salt-water, sea-dikes must be faced with stone,
fascines, or some other revetement. [Footnote: The dikes are sometimes
founded upon piles, and sometimes protected by one or more rows of piles
driven deeply down into the bed of the sea in front of them. "Triple rows of
piles of Scandinavian pine," says Wild, "have been driven down along the
coast of Friesland, where there are no dunes, for a distance of one hundred
and fifty miles. The piles are bound together by strong cross-timbers and
iron clamps, and the interstices filled with stones. The ground adjacent to
the piling is secured with fascines, and at exposed points heavy blocks of
stone are heaped up as an additional protection. The earth-dike is built
behind the mighty bulwark of this breakwater, and its foot also is fortified
with stones." … "The great Helder dike is about five miles long and forty
feet wide at the top, along which runs a good road. It slopes down two
hundred feet into the sea, at an angle of forty degrees. The highest waves do
not reach the summit, the lowest always cover its base. At certain distances,
immense buttresses, of a height and width proportioned to those of the dike,
and even more strongly built, run several hundred feet out into the rolling
sea. This gigantic artificial coast is entirely composed of Norwegian
granite."—Wild, Die Niederlande, i., pp. 61, 62.] Upon the coast of
Schleswig and Holstein, where the people have less capital at their
command, they defend their embankments against ice and the waves by a
coating of twisted straw or reeds, which must be renewed as often as once,
Page 523
sometimes twice a year. The inhabitants of these coasts call the chain of
dikes "the golden border," a name it well deserves, whether we suppose it to
refer to its enormous cost, or, as is more probable, to its immense value as a
protection to their fields and their firesides.
When outlying flats are enclosed by building new embankments the old
interior dikes are suffered to remain, both as an additional security against
the waves, and because the removal of them would be expensive. They
serve, also, as roads or causeways, a purpose for which the embankments
nearest the sea are seldom employed, because the whole structure might be
endangered from the breaking of the turf by wheels and the hoofs of horses.
Where successive rows of dikes have been thus constructed, it is observed
that the ground defended by the more ancient embankments is lower than
that embraced within the newer enclosures, and this depression of level has
been ascribed to a general subsidence of the coast from geological causes;
[Footnote: A similar subsidence of the surface is observed in the diked
ground of the Lincolnshire fens, where there is no reason to suspect a
general depression from geological causes.] but the better opinion seems to
be that it is, in most cases, due merely to the consolidation and settling of
the earth from being more effectually dried, from the weight of the dikes,
from the tread of men and cattle, and from the movement of the heavy
wagons which carry off the crops. [Footnote: The shaking of the ground,
even when loaded with large buildings, by the passage of heavy carriages or
artillery, or by the march of a body of cavalry or even infantry, shows that
such causes may produce important mechanical effects on the condition of
the soil. The bogs in the Netherlands, as in most other countries, contain
large numbers of fallen trees, buried to a certain depth by earth and
vegetable mould. When the bogs are dry enough to serve as pastures, it is
observed that trunks of these ancient trees rise of themselves to the surface.
Staring ascribes this singular phenomenon to the agitation of the ground by
the tread of cattle. "When roadbeds," observes he, "are constructed of
dikes "the golden border," a name it well deserves, whether we suppose it to
refer to its enormous cost, or, as is more probable, to its immense value as a
protection to their fields and their firesides.
When outlying flats are enclosed by building new embankments the old
interior dikes are suffered to remain, both as an additional security against
the waves, and because the removal of them would be expensive. They
serve, also, as roads or causeways, a purpose for which the embankments
nearest the sea are seldom employed, because the whole structure might be
endangered from the breaking of the turf by wheels and the hoofs of horses.
Where successive rows of dikes have been thus constructed, it is observed
that the ground defended by the more ancient embankments is lower than
that embraced within the newer enclosures, and this depression of level has
been ascribed to a general subsidence of the coast from geological causes;
[Footnote: A similar subsidence of the surface is observed in the diked
ground of the Lincolnshire fens, where there is no reason to suspect a
general depression from geological causes.] but the better opinion seems to
be that it is, in most cases, due merely to the consolidation and settling of
the earth from being more effectually dried, from the weight of the dikes,
from the tread of men and cattle, and from the movement of the heavy
wagons which carry off the crops. [Footnote: The shaking of the ground,
even when loaded with large buildings, by the passage of heavy carriages or
artillery, or by the march of a body of cavalry or even infantry, shows that
such causes may produce important mechanical effects on the condition of
the soil. The bogs in the Netherlands, as in most other countries, contain
large numbers of fallen trees, buried to a certain depth by earth and
vegetable mould. When the bogs are dry enough to serve as pastures, it is
observed that trunks of these ancient trees rise of themselves to the surface.
Staring ascribes this singular phenomenon to the agitation of the ground by
the tread of cattle. "When roadbeds," observes he, "are constructed of
Page 524
gravel and pebbles of different sizes, and these latter are placed at the
bottom without being broken and rolled hard together, they are soon
brought to the top by the effect of travel on the road. Lying loosely, they
undergo some motion from the passage of every wagon-wheel and the tread
of every horse that passes over them. This motion is an oscillation or partial
rolling, and as one side of a pebble is raised, a little fine sand or earth is
forced under it, and the frequent repetition of this process by cattle or
carriages moving in opposite directions brings it at last to the surface. We
may suppose that a similar effect is produced on the stems of trees in the
bogs by the tread of animals."—De Bodem van Nederland, i., pp. 75, 76.
It is observed in the Northern United States, that when soils containing
pebbles are cleared and cultivated, and the stones removed from the surface,
new pebbles, and even bowlders of many pounds weight, continue to show
themselves above the ground, every spring, for a long series of years. In
clayey soils the fence-posts are thrown up in a similar way, and it is not
uncommon to see the lower rail of a fence thus gradually raised a foot or
even two feet above the ground. This rising of stones and fences is
popularly ascribed to the action of the severe frosts of that climate. The
expansion of the ground, in freezing, it is said, raises its surface, and, with
the surface, objects lying near or connected with it. When the soil thaws in
the spring, it settles back again to its former level, while the pebbles and
posts are prevented from sinking as low as before by loose earth which has
fallen under them. The fact that the elevation spoken of is observed only in
the spring gives countenance to this theory, which is perhaps applicable also
to the cases stated by Staring, and it is probable that the two causes above
assigned concur in producing the effect.
The question of the subsidence of the Netherlandish coast has been much
discussed. Not to mention earlier geologists, Venema, in several essays, and
particularly in Het Dalen van de Noordelijke Kuststreken van ons Land,
bottom without being broken and rolled hard together, they are soon
brought to the top by the effect of travel on the road. Lying loosely, they
undergo some motion from the passage of every wagon-wheel and the tread
of every horse that passes over them. This motion is an oscillation or partial
rolling, and as one side of a pebble is raised, a little fine sand or earth is
forced under it, and the frequent repetition of this process by cattle or
carriages moving in opposite directions brings it at last to the surface. We
may suppose that a similar effect is produced on the stems of trees in the
bogs by the tread of animals."—De Bodem van Nederland, i., pp. 75, 76.
It is observed in the Northern United States, that when soils containing
pebbles are cleared and cultivated, and the stones removed from the surface,
new pebbles, and even bowlders of many pounds weight, continue to show
themselves above the ground, every spring, for a long series of years. In
clayey soils the fence-posts are thrown up in a similar way, and it is not
uncommon to see the lower rail of a fence thus gradually raised a foot or
even two feet above the ground. This rising of stones and fences is
popularly ascribed to the action of the severe frosts of that climate. The
expansion of the ground, in freezing, it is said, raises its surface, and, with
the surface, objects lying near or connected with it. When the soil thaws in
the spring, it settles back again to its former level, while the pebbles and
posts are prevented from sinking as low as before by loose earth which has
fallen under them. The fact that the elevation spoken of is observed only in
the spring gives countenance to this theory, which is perhaps applicable also
to the cases stated by Staring, and it is probable that the two causes above
assigned concur in producing the effect.
The question of the subsidence of the Netherlandish coast has been much
discussed. Not to mention earlier geologists, Venema, in several essays, and
particularly in Het Dalen van de Noordelijke Kuststreken van ons Land,
Page 525
1854, adduces many facts and arguments to prove a slow sinking of the
northere provinces of Holland. Laveleye (Affaissement du sol at
envasement des fleuves survenus dans les temps historiques, 1859), upon a
still fuller investigation, arrives at the same conclusion. The eminent
geologist Staring, however, who briefly refers to the subject in De Bodem
van Nederland, i., p. 356 et seqq., does not consider the evidence sufficient
to prove anything more than the sinking of the surface of the polders from
drying and consolidation.—See Elisee Reclus, La Terre, vol. i., pp. 730,
732.]
Notwithstanding this slow sinking, most of the land enclosed by dikes is
still above low-water mark, and can, therefore, be wholly or partially freed
from rain-water, and from that received by infiltration from higher ground,
by sluices opened at the ebb of the tide. For this purpose the land is
carefully ditched, and advantage is taken of every favorable occasion for
discharging the water through the sluices. But the ground cannot be
effectually drained by this means, unless it is elevated four or five feet, at
least, above the level of the ebb-tide because the ditches would not
otherwise have a sufficient descent to carry the water off in the short
interval between ebb and flow, and because the moisture of the saturated
sub-soil is always rising by capillary attraction. Whenever, therefore, the
soil has sunk below the level I have mentioned, and in cases where its
surface has never been raised above it, pumps, worked by wind or some
other mechanical power, must be very frequently employed to keep the land
dry enough for pasturage and cultivation. [Footnote: The elevation of the
lands enclosed by dikes—or polders, as they are called in Holland—above
low-water mark, depends upon the height of the tides or, in other words,
upon the difference between ebb and flood. The tide cannot deposit earth
higher than it flows, and after the ground is once enclosed, the decay of the
vegetables grown upon it and the addition of manures do not compensate
the depression occasional by drying and consolidation. On the coast of
northere provinces of Holland. Laveleye (Affaissement du sol at
envasement des fleuves survenus dans les temps historiques, 1859), upon a
still fuller investigation, arrives at the same conclusion. The eminent
geologist Staring, however, who briefly refers to the subject in De Bodem
van Nederland, i., p. 356 et seqq., does not consider the evidence sufficient
to prove anything more than the sinking of the surface of the polders from
drying and consolidation.—See Elisee Reclus, La Terre, vol. i., pp. 730,
732.]
Notwithstanding this slow sinking, most of the land enclosed by dikes is
still above low-water mark, and can, therefore, be wholly or partially freed
from rain-water, and from that received by infiltration from higher ground,
by sluices opened at the ebb of the tide. For this purpose the land is
carefully ditched, and advantage is taken of every favorable occasion for
discharging the water through the sluices. But the ground cannot be
effectually drained by this means, unless it is elevated four or five feet, at
least, above the level of the ebb-tide because the ditches would not
otherwise have a sufficient descent to carry the water off in the short
interval between ebb and flow, and because the moisture of the saturated
sub-soil is always rising by capillary attraction. Whenever, therefore, the
soil has sunk below the level I have mentioned, and in cases where its
surface has never been raised above it, pumps, worked by wind or some
other mechanical power, must be very frequently employed to keep the land
dry enough for pasturage and cultivation. [Footnote: The elevation of the
lands enclosed by dikes—or polders, as they are called in Holland—above
low-water mark, depends upon the height of the tides or, in other words,
upon the difference between ebb and flood. The tide cannot deposit earth
higher than it flows, and after the ground is once enclosed, the decay of the
vegetables grown upon it and the addition of manures do not compensate
the depression occasional by drying and consolidation. On the coast of
Page 526
Zeeland and the islands of South Holland, the tides, and of course the
surface of the lands deposited by them, are so high that the polders can be
drained by ditching and sluices, but at other points, as in the enclosed
grounds of North Holland on the Zuiderzee, where the tide rises but three
feet or even less, pumping is necessary from the beginning.—Staring,
Voormaals en Thans, p. 152]
DRAINING OF THE LAKE OF HAARLEM.
The substitution of steam-engines for the feeble and uncertain action of
windmills, in driving pumps, has much facilitated the removal of water
from the polders as well as the draining of lakes, marshes, and shallow
bays, and thus given such an impulse to these enterprises, that not less than
one hundred and ten thousand acres wore reclaimed from the waters, and
added to the agricultural domain of the Netherlands, between 1815 and
1855. The most important of these undertaking was the draining of the Lake
of Haarlem, and for this purpose some of the most powerful hydraulic
engines over constructed were designed and executed. [Footnote: The
principal engine, of 500 horse-power, drove eleven pumps with a total
delivery of 31,000 cubic yards per hour.—Wild, Die Netherland, i., p. 87.]
The origin of this lake is unknown. It is supposed by some geographers to
be a part of an ancient bed of the Rhine, the channel of which, as there is
good reason to believe, has undergone great changes since the Roman
invasion of the Netherlands; by others it is thought to have once formed an
inland marine channel, separated from the sea by a chain of low islands,
which the sand washed up by the tides has since connected with the
mainland and converted into a continuous line of coast. The best authorities,
however, find geological evidence that the surface occupied by the lake was
originally a marshy tract containing within its limits little solid ground, but
many ponds and inlets, and much floating as well as fixed fen.
surface of the lands deposited by them, are so high that the polders can be
drained by ditching and sluices, but at other points, as in the enclosed
grounds of North Holland on the Zuiderzee, where the tide rises but three
feet or even less, pumping is necessary from the beginning.—Staring,
Voormaals en Thans, p. 152]
DRAINING OF THE LAKE OF HAARLEM.
The substitution of steam-engines for the feeble and uncertain action of
windmills, in driving pumps, has much facilitated the removal of water
from the polders as well as the draining of lakes, marshes, and shallow
bays, and thus given such an impulse to these enterprises, that not less than
one hundred and ten thousand acres wore reclaimed from the waters, and
added to the agricultural domain of the Netherlands, between 1815 and
1855. The most important of these undertaking was the draining of the Lake
of Haarlem, and for this purpose some of the most powerful hydraulic
engines over constructed were designed and executed. [Footnote: The
principal engine, of 500 horse-power, drove eleven pumps with a total
delivery of 31,000 cubic yards per hour.—Wild, Die Netherland, i., p. 87.]
The origin of this lake is unknown. It is supposed by some geographers to
be a part of an ancient bed of the Rhine, the channel of which, as there is
good reason to believe, has undergone great changes since the Roman
invasion of the Netherlands; by others it is thought to have once formed an
inland marine channel, separated from the sea by a chain of low islands,
which the sand washed up by the tides has since connected with the
mainland and converted into a continuous line of coast. The best authorities,
however, find geological evidence that the surface occupied by the lake was
originally a marshy tract containing within its limits little solid ground, but
many ponds and inlets, and much floating as well as fixed fen.
Page 527
In consequence of the cutting of turf for fuel, and the destruction of the
few trees and shrubs which held the loose soil together with their roots, the
ponds are supposed to have gradually extended themselves, until the action
of the wind upon their enlarged surface gave their waves sufficient force to
overcome the resistance of the feeble barriers which separated them, and to
unite them all into a single lake. Popular tradition, it is true, ascribes the
formation of the Lake of Haarlem to a single irruption of the sea, at a
remote period, and connects it with one or another of the destructive
inundations of which the Netherland chronicles describe so many; but on a
map of the year 1531, a chain of four smaller waters occupies nearly the
ground afterwards covered by the Lake of Haarlem, and they have most
probably been united by gradual encroachments resulting from the
improvident practices above referred to, though no doubt the consummation
may have been hastened by floods, and by the neglect to maintain dikes, or
the intentional destruction of them, in the long wars of the sixteenth
century.
The Lake of Haarlem was a body of water not far from fifteen miles in
length, by seven in greatest width, lying between the cities of Amsterdam
and Leyden, running parallel with the coast of Holland at the distance of
about five miles from the sea, and covering an area of about 45,000 acres.
By means of the Ij, it communicated with the Zuiderzee, the Mediterranean
of the Netherlands, and its surface was little above the mean elevation of
that of the sea. Whenever, therefore, the waters of the Zuiderzee were acted
upon by strong north-west winds, those of the Lake of Haarlem were raised
proportionally and driven southwards, while winds from the south tended to
create a flow in the opposite direction. The shores of the lake were
everywhere low, and though between the years 1767 and 1848 more than
$1,700,000 had been expended in checking its encroachments, it often burst
its barriers, and produced destructive inundations. In November, 1836, a
south wind brought its waters to the very gates of Amsterdam, and in
few trees and shrubs which held the loose soil together with their roots, the
ponds are supposed to have gradually extended themselves, until the action
of the wind upon their enlarged surface gave their waves sufficient force to
overcome the resistance of the feeble barriers which separated them, and to
unite them all into a single lake. Popular tradition, it is true, ascribes the
formation of the Lake of Haarlem to a single irruption of the sea, at a
remote period, and connects it with one or another of the destructive
inundations of which the Netherland chronicles describe so many; but on a
map of the year 1531, a chain of four smaller waters occupies nearly the
ground afterwards covered by the Lake of Haarlem, and they have most
probably been united by gradual encroachments resulting from the
improvident practices above referred to, though no doubt the consummation
may have been hastened by floods, and by the neglect to maintain dikes, or
the intentional destruction of them, in the long wars of the sixteenth
century.
The Lake of Haarlem was a body of water not far from fifteen miles in
length, by seven in greatest width, lying between the cities of Amsterdam
and Leyden, running parallel with the coast of Holland at the distance of
about five miles from the sea, and covering an area of about 45,000 acres.
By means of the Ij, it communicated with the Zuiderzee, the Mediterranean
of the Netherlands, and its surface was little above the mean elevation of
that of the sea. Whenever, therefore, the waters of the Zuiderzee were acted
upon by strong north-west winds, those of the Lake of Haarlem were raised
proportionally and driven southwards, while winds from the south tended to
create a flow in the opposite direction. The shores of the lake were
everywhere low, and though between the years 1767 and 1848 more than
$1,700,000 had been expended in checking its encroachments, it often burst
its barriers, and produced destructive inundations. In November, 1836, a
south wind brought its waters to the very gates of Amsterdam, and in
Page 528
December of the same year, in a north-west gale, they overflowed twenty
thousand acres of land at the southern extremity of the lake, and flooded a
part of the city of Leyden. The depth of water in the lake did not, in general,
exceed fourteen feet, but the bottom was a semi-fluid ooze or slime, which
partook of the agitation of the waves, and added considerably to their
mechanical force. Serious fears were entertained that the lake would form a
junction with the inland waters of the Legmeer and Mijdrecht, swallow up a
vast extent of valuable soil, and finally endanger the security of a large
proportion of the land which the industry of Holland had gained in the
course of centuries from the ocean.
For this reason, and for the sake of the large addition the bottom of the
lake would make to the cultivable soil of the state, it was resolved to drain
it, and the preliminary steps for that purpose were commenced in the year
1840. The first operation was to surround the entire lake with a ring-canal
and dike, in order to cut off the communication with the Ij, and to exclude
the water of the streams and morasses which discharged themselves into it
from the land side. The dike was composed of different materials, according
to the means of supply at different points, such as sand from the coast-
dunes, earth and turf excavated from the line of the ring-canal, and floating
turf, [Footnote: In England and New England, where the marshes have been
already drained or are of comparatively small extent, the existence of large
floating islands seems incredible, and has sometimes been treated as a fable,
but no geographical fact is better established. Kohl (Inseln und Marschen
Schleswig-Holsteins, iii., p. 309) reminds us that Pliny mentions among the
wonders of Germany the floating islands, covered with trees, which met the
Roman fleets at the mouths of the Elbe and the Weser. Our author speaks
also of having visited, in the territory of Bremen, floating moors, bearing
not only houses but whole villages. At low stages of the water these moors
rest upon a bed of sand, but are raised from six to ten feet by the high water
of spring, and remain afloat until, in the course of the summer, the water
thousand acres of land at the southern extremity of the lake, and flooded a
part of the city of Leyden. The depth of water in the lake did not, in general,
exceed fourteen feet, but the bottom was a semi-fluid ooze or slime, which
partook of the agitation of the waves, and added considerably to their
mechanical force. Serious fears were entertained that the lake would form a
junction with the inland waters of the Legmeer and Mijdrecht, swallow up a
vast extent of valuable soil, and finally endanger the security of a large
proportion of the land which the industry of Holland had gained in the
course of centuries from the ocean.
For this reason, and for the sake of the large addition the bottom of the
lake would make to the cultivable soil of the state, it was resolved to drain
it, and the preliminary steps for that purpose were commenced in the year
1840. The first operation was to surround the entire lake with a ring-canal
and dike, in order to cut off the communication with the Ij, and to exclude
the water of the streams and morasses which discharged themselves into it
from the land side. The dike was composed of different materials, according
to the means of supply at different points, such as sand from the coast-
dunes, earth and turf excavated from the line of the ring-canal, and floating
turf, [Footnote: In England and New England, where the marshes have been
already drained or are of comparatively small extent, the existence of large
floating islands seems incredible, and has sometimes been treated as a fable,
but no geographical fact is better established. Kohl (Inseln und Marschen
Schleswig-Holsteins, iii., p. 309) reminds us that Pliny mentions among the
wonders of Germany the floating islands, covered with trees, which met the
Roman fleets at the mouths of the Elbe and the Weser. Our author speaks
also of having visited, in the territory of Bremen, floating moors, bearing
not only houses but whole villages. At low stages of the water these moors
rest upon a bed of sand, but are raised from six to ten feet by the high water
of spring, and remain afloat until, in the course of the summer, the water
Page 529
beneath is exhausted by evaporation and drainage, when they sink down
upon the sand again.
Staring explains, in an interesting way, the whole growth, formation, and
functions of floating fens or bogs, in his very valuable work, De Bodem van
Nederland, i., pp. 36-43. The substance of his account is as follows: The
turf and the surface of the fens, is stillness of the water. Hence they are not
found in running streams, nor in pools so large as to be subject to frequent
agitation by the wind. For example, not a single plant grew in the open part
of the Lake of Haarlem, and fens cease to form in all pools as soon as, by
the cutting of the turf for fuel or other purposes, their area is sufficiently
enlarged to be much acted on by wind. When still water above a yard deep
is left undisturbed, aquatic plants of various genera, such as Nuphar,
Nymphaea, Limnanthemum, Stratiotes, Polygonum, and Potamogeton, fill
the bottom with roots and cover the surface with leaves. Many of the plants
die every year, and prepare at the bottom a soil fit for the growth of a higher
order of vegetation, Phragmites, Acorus, Sparganium, Rumex, Lythrum,
Pedicularis, Spiraea, Polystichum, Comarum, Caltha, etc., etc. In the course
of twenty or thirty years the muddy bottom is filled with roots of aquatic
and marsh plants, which are lighter than water, and if the depth is great
enough to give room for detaching this vegetable network, a couple of yard
for example, it rises to the surface, bearing with it, of course, the soil
formed above it by decay of stems and leaves. New genera now appear
upon the mass, such a Carex, Menyanthes, and others, and soon thicky
cover it. The turf has now acquired a thickness of from two to four feet, and
is called in Groningen lad; in Friesland, til, tilland, or drifftil; in Overijsse,
krag; and in Holland, rietzod. It floats about as driven by the wind,
gradually increasing in thickness by the decay of its annual crops of
vegetation, and in about half a century reaches the bottom and becomes
fixed. If it has not been invaded in the meantime by men or cattle, trees and
arborescent plants, Alnus, Salix, Myrica, etc., appear, and these contribute
upon the sand again.
Staring explains, in an interesting way, the whole growth, formation, and
functions of floating fens or bogs, in his very valuable work, De Bodem van
Nederland, i., pp. 36-43. The substance of his account is as follows: The
turf and the surface of the fens, is stillness of the water. Hence they are not
found in running streams, nor in pools so large as to be subject to frequent
agitation by the wind. For example, not a single plant grew in the open part
of the Lake of Haarlem, and fens cease to form in all pools as soon as, by
the cutting of the turf for fuel or other purposes, their area is sufficiently
enlarged to be much acted on by wind. When still water above a yard deep
is left undisturbed, aquatic plants of various genera, such as Nuphar,
Nymphaea, Limnanthemum, Stratiotes, Polygonum, and Potamogeton, fill
the bottom with roots and cover the surface with leaves. Many of the plants
die every year, and prepare at the bottom a soil fit for the growth of a higher
order of vegetation, Phragmites, Acorus, Sparganium, Rumex, Lythrum,
Pedicularis, Spiraea, Polystichum, Comarum, Caltha, etc., etc. In the course
of twenty or thirty years the muddy bottom is filled with roots of aquatic
and marsh plants, which are lighter than water, and if the depth is great
enough to give room for detaching this vegetable network, a couple of yard
for example, it rises to the surface, bearing with it, of course, the soil
formed above it by decay of stems and leaves. New genera now appear
upon the mass, such a Carex, Menyanthes, and others, and soon thicky
cover it. The turf has now acquired a thickness of from two to four feet, and
is called in Groningen lad; in Friesland, til, tilland, or drifftil; in Overijsse,
krag; and in Holland, rietzod. It floats about as driven by the wind,
gradually increasing in thickness by the decay of its annual crops of
vegetation, and in about half a century reaches the bottom and becomes
fixed. If it has not been invaded in the meantime by men or cattle, trees and
arborescent plants, Alnus, Salix, Myrica, etc., appear, and these contribute
Page 530
to hasten the attachment of the turf to the bottom, both by their weight and
by sending their roots quite through into the ground."
This is the regular method employed by nature for the gradual filling up
of shallow lakes and pools, and converting them first into morass and then
into dry land. Whenever, therefore, man removes the peat or turf, he exerts
an injurious geographical agency, and, as I have already said, there is no
doubt that the immense extension of the inland seas of Holland in modern
times is owing to this and other human imprudences. "Hundreds of hectares
of floating pastures," says our author, "which have nothing in their
appearance to distinguish them from grass-lands resting on solid bog, are
found in Overijssel, in North Holland, and near Utrecht. In short, they occur
in all deep bogs, and wherever deep water is left long undisturbed."
In one case a floating island, which had attached itself to the shore,
continued to float about for a long time after it was torn off by a flood, and
was solid enough to keep a pond of fresh water upon it sweet, though the
water in which it was swimming had become brackish from the irruption of
the sea. After the hay is cut, cattle are pastured, and occasionally root-crops
grown upon these islands, and they sometimes have large trees growing
upon them.
When the turf or peat has been cut, leaving water less than a yard deep,
Equisetum limosum grows at once, and is followed by the second class of
marsh plants mentioned above. Their roots do not become detached from
the bottom in such shallow water, but form ordinary turf or peat. These
processes are so rapid that a thickness of from three to six feet of turf is
formed in half a century, and many men have lived to mow grass where
they had fished in their boyhood, and to cut turf twice in the same spot. In
Ireland the growth of peat is said to be much more rapid. Elisee Reclus, La
Terre, i., 591, 592. But see Asbjornsen, Torv og Torvdrift, ii., 29, 30.
by sending their roots quite through into the ground."
This is the regular method employed by nature for the gradual filling up
of shallow lakes and pools, and converting them first into morass and then
into dry land. Whenever, therefore, man removes the peat or turf, he exerts
an injurious geographical agency, and, as I have already said, there is no
doubt that the immense extension of the inland seas of Holland in modern
times is owing to this and other human imprudences. "Hundreds of hectares
of floating pastures," says our author, "which have nothing in their
appearance to distinguish them from grass-lands resting on solid bog, are
found in Overijssel, in North Holland, and near Utrecht. In short, they occur
in all deep bogs, and wherever deep water is left long undisturbed."
In one case a floating island, which had attached itself to the shore,
continued to float about for a long time after it was torn off by a flood, and
was solid enough to keep a pond of fresh water upon it sweet, though the
water in which it was swimming had become brackish from the irruption of
the sea. After the hay is cut, cattle are pastured, and occasionally root-crops
grown upon these islands, and they sometimes have large trees growing
upon them.
When the turf or peat has been cut, leaving water less than a yard deep,
Equisetum limosum grows at once, and is followed by the second class of
marsh plants mentioned above. Their roots do not become detached from
the bottom in such shallow water, but form ordinary turf or peat. These
processes are so rapid that a thickness of from three to six feet of turf is
formed in half a century, and many men have lived to mow grass where
they had fished in their boyhood, and to cut turf twice in the same spot. In
Ireland the growth of peat is said to be much more rapid. Elisee Reclus, La
Terre, i., 591, 592. But see Asbjornsen, Torv og Torvdrift, ii., 29, 30.
Page 531
Captain Gilliss says that before Lake Taguataga in Chili was drained,
there were in it islands composed of dead plants matted together to a
thickness of from four to six feet, and with trees of medium size growing
upon them. These islands floated before the wind "with their trees and
browsing cattle."—United States Naval Astronomical Expedition to the
Southern Hemisphere, i., pp. 16, 17.] fascines being everywhere used to
bind and compact the mass together. This operation was completed in 1848,
and three steam-pumps were then employed for five years in discharging
the water. The whole enterprise was conducted at the expense of the state,
and in 1853 the recovered lands were offered for sale for its benefit. Up to
1858, forty-two thousand acres had been sold at not far from sixteen pounds
sterling or seventy-seven dollars an acre, amounting altogether to L661,000
sterling or $3,200,000. The unsold lands were valued at more than L6,000
or nearly $30,000, and as the total cost was L764,500 or about $3,700,000,
the direct loss to the state, exclusive of interest on the capital expended,
may be stated at L100,000 or something less than $500,000.
The success of this operation has encouraged others of like nature in
Holland. The Zuid Plas, which covered 11,500 acres and was two feet
deeper than the Lake of Haarlem, has been drained, and a similar work now
in course of execution on an arm of the Scheld, will recover about 35,000
acres.
In a country like the United States, of almost boundless extent of sparsely
inhabited territory, such an expenditure for such an object would be poor
economy. But Holland has a narrow domain, great pecuniary resources, an
excessively crowded population, and a consequent need of enlarged room
and opportunity for the exercise of industry. Under such circumstances, and
especially with an exposure to dangers so formidable, there is no question
of the wisdom of the measure. It has already provided homes and
occupation for more than five thousand citizens, and furnished a profitable
there were in it islands composed of dead plants matted together to a
thickness of from four to six feet, and with trees of medium size growing
upon them. These islands floated before the wind "with their trees and
browsing cattle."—United States Naval Astronomical Expedition to the
Southern Hemisphere, i., pp. 16, 17.] fascines being everywhere used to
bind and compact the mass together. This operation was completed in 1848,
and three steam-pumps were then employed for five years in discharging
the water. The whole enterprise was conducted at the expense of the state,
and in 1853 the recovered lands were offered for sale for its benefit. Up to
1858, forty-two thousand acres had been sold at not far from sixteen pounds
sterling or seventy-seven dollars an acre, amounting altogether to L661,000
sterling or $3,200,000. The unsold lands were valued at more than L6,000
or nearly $30,000, and as the total cost was L764,500 or about $3,700,000,
the direct loss to the state, exclusive of interest on the capital expended,
may be stated at L100,000 or something less than $500,000.
The success of this operation has encouraged others of like nature in
Holland. The Zuid Plas, which covered 11,500 acres and was two feet
deeper than the Lake of Haarlem, has been drained, and a similar work now
in course of execution on an arm of the Scheld, will recover about 35,000
acres.
In a country like the United States, of almost boundless extent of sparsely
inhabited territory, such an expenditure for such an object would be poor
economy. But Holland has a narrow domain, great pecuniary resources, an
excessively crowded population, and a consequent need of enlarged room
and opportunity for the exercise of industry. Under such circumstances, and
especially with an exposure to dangers so formidable, there is no question
of the wisdom of the measure. It has already provided homes and
occupation for more than five thousand citizens, and furnished a profitable
Page 532
investment for a private capital of not less than L400,000 sterling or
$2,000,000, which has been expended in improvements over and above the
purchase money of the soil; and the greater part of this sum, as well as of
the cost of drainage, has been paid as a compensation for labor. The excess
of governmental expenditure over the receipts, if employed in constructing
ships of war or fortifications, would have added little to the military
strength of the kingdom; but the increase of territory, the multiplication of
homes and firesides which the people have an interest in defending, and the
augmentation of agricultural resources, constitute a stronger bulwark
against foreign invasion than a ship of the line or a fortress armed with a
hundred cannon.
Draining of the Zuiderzee.
I have referred to the draining of the Lake of Haarlem as an operation of
great geographical as well as economical and mechanical interest. A much
more gigantic project, of a similar character, is now engaging the attention
of the Netherlandish engineers. It is proposed to drain the great salt-water
basin called the Zuiderzee. This inland sea covers an area of not less than
two thousand square miles, or about one million three hundred thousand
acres. The seaward half, or that portion lying north-west of a line drawn
from Enkhuizen to Stavoren, is believed to have been converted from a
marsh to an open bay since the fifth century after Christ, and this change is
ascribed, partly if not wholly, to the interference of man with the order of
nature. The Zuiderzee communicates with the sea by at least six
considerable channels, separated from each other by low islands, and the
tide rises within the basin to the height of three feet. To drain the Zuiderzee,
these channels must first be closed and the passage of the tidal flood
through them cut off. If this be done, the coast currents will be restored
approximately to the lines they followed fourteen or fifteen centuries ago,
$2,000,000, which has been expended in improvements over and above the
purchase money of the soil; and the greater part of this sum, as well as of
the cost of drainage, has been paid as a compensation for labor. The excess
of governmental expenditure over the receipts, if employed in constructing
ships of war or fortifications, would have added little to the military
strength of the kingdom; but the increase of territory, the multiplication of
homes and firesides which the people have an interest in defending, and the
augmentation of agricultural resources, constitute a stronger bulwark
against foreign invasion than a ship of the line or a fortress armed with a
hundred cannon.
Draining of the Zuiderzee.
I have referred to the draining of the Lake of Haarlem as an operation of
great geographical as well as economical and mechanical interest. A much
more gigantic project, of a similar character, is now engaging the attention
of the Netherlandish engineers. It is proposed to drain the great salt-water
basin called the Zuiderzee. This inland sea covers an area of not less than
two thousand square miles, or about one million three hundred thousand
acres. The seaward half, or that portion lying north-west of a line drawn
from Enkhuizen to Stavoren, is believed to have been converted from a
marsh to an open bay since the fifth century after Christ, and this change is
ascribed, partly if not wholly, to the interference of man with the order of
nature. The Zuiderzee communicates with the sea by at least six
considerable channels, separated from each other by low islands, and the
tide rises within the basin to the height of three feet. To drain the Zuiderzee,
these channels must first be closed and the passage of the tidal flood
through them cut off. If this be done, the coast currents will be restored
approximately to the lines they followed fourteen or fifteen centuries ago,
Page 533
and thero can be little doubt that an appreciable effect will thus be produced
upon all the tidal phenomena of that coast, and, of course, upon the
maritime geography of Holland.
A ring-dike and canal must then be constructed around the landward side
of the basin, to exclude and carry off the freshwater streams which now
empty into it. One of these, the Ijssel, a considerable river, has a course of
eighty miles, and is, in fact, one of the outlets of the Rhine, though
augmented by the waters of several independent tributaries. These
preparations being made, and perhaps transverse dikes erected at
convenient points for dividing the gulf into smaller portions, the water must
be pumped out by machinery, in substantially the same way as in the case of
the Lake of Haarlem. [Footnote: The dependence of man upon the aid of
spontaneous nature, in his most arduous material works, is curiously
illustrated by the fact that one of the most serious difficulties to be
encountered in executing this gigantic scheme is that of procuring
brushwood for the fascines to be employed in the embankments. See
Diggelen's pamphlet, "Groote Werken in Nederland."] No safe calculations
can be made as to the expenditure of time and money required for the
execution of this stupendous enterprise, but I believe its practicability is not
denied by competent judges, though doubts are entertained as to its
financial expediency. [Footnote: The plan at present most in favor is that
which proposes the drainage of only a portion of the southern half of the
Zuiderzee, which covers not far from 400,000 acres. The project for the
construction of a ship-canal directly from Amsterdam to the North Sea, now
in course of execution, embraces the drainage of the Ij, a nearly land-locked
basin communicating with the Zuiderzee and covering more than 12,000
acres. See official reports on these projects in Droogmaking vom het
zuidelyk gedeelte der Zuiderzee, te s' Gravenhage, 1868, 4to.] The
geographical results of this improvement would be analogous to those of
the draining of the Lake of Haarlem, but many times multiplied in extent,
upon all the tidal phenomena of that coast, and, of course, upon the
maritime geography of Holland.
A ring-dike and canal must then be constructed around the landward side
of the basin, to exclude and carry off the freshwater streams which now
empty into it. One of these, the Ijssel, a considerable river, has a course of
eighty miles, and is, in fact, one of the outlets of the Rhine, though
augmented by the waters of several independent tributaries. These
preparations being made, and perhaps transverse dikes erected at
convenient points for dividing the gulf into smaller portions, the water must
be pumped out by machinery, in substantially the same way as in the case of
the Lake of Haarlem. [Footnote: The dependence of man upon the aid of
spontaneous nature, in his most arduous material works, is curiously
illustrated by the fact that one of the most serious difficulties to be
encountered in executing this gigantic scheme is that of procuring
brushwood for the fascines to be employed in the embankments. See
Diggelen's pamphlet, "Groote Werken in Nederland."] No safe calculations
can be made as to the expenditure of time and money required for the
execution of this stupendous enterprise, but I believe its practicability is not
denied by competent judges, though doubts are entertained as to its
financial expediency. [Footnote: The plan at present most in favor is that
which proposes the drainage of only a portion of the southern half of the
Zuiderzee, which covers not far from 400,000 acres. The project for the
construction of a ship-canal directly from Amsterdam to the North Sea, now
in course of execution, embraces the drainage of the Ij, a nearly land-locked
basin communicating with the Zuiderzee and covering more than 12,000
acres. See official reports on these projects in Droogmaking vom het
zuidelyk gedeelte der Zuiderzee, te s' Gravenhage, 1868, 4to.] The
geographical results of this improvement would be analogous to those of
the draining of the Lake of Haarlem, but many times multiplied in extent,
Page 534
and its meteorological effects, though perhaps not perceptible on the coast,
could hardly fail to be appreciable in the interior of Holland.
The bearing of the works I have noticed, and of others similar in
character, upon the social and moral, as well as the purely economical,
interests of the people of the Netherlands, has induced me to describe them
more in detail than the general purpose of this volume may be thought to
justify; but if we consider them simply from a geographical point of view,
we shall find that they are possessed of no small importance as
modifications of the natural condition of terrestrial surface. There is good
reason to believe that before the establishment of a partially civilized race
upon the territory now occupied by Dutch, Frisic, and Low German
communities, the grounds not exposed to inundation were overgrown with
dense woods; that the lowlands between these forests and the sea-coasts
were marshes, covered and partially solidified by a thick matting of peat-
plants and shrubs interspersed with trees; and that even the sand-dunes of
the shore were protected by a vegetable growth which, in a great measure,
prevented the drifting and translocation of them.
The present causes of river and coast erosion existed, indeed, at the
period in question; but some of them must have acted with less intensity,
there were strong natural safeguards against the influence of marine and
fresh-water currents, and the conflicting tendencies had arrived at a
condition of approximate equilibrium, which permitted but slow and
gradual changes in the face of nature. The destruction of the forests around
the sources and along the valleys of the rivers by man gave them a more
torrential character. The felling of the trees, and the extirpation of the
shrubbery upon the fens by domestic cattle, deprived the surface of its
cohesion and consistence, and the cutting of peat for fuel opened cavities in
it, which, filling at once with water, rapidly extended themselves by
abrasion of their borders, and finally enlarged to pools, lakes, and gulfs, like
could hardly fail to be appreciable in the interior of Holland.
The bearing of the works I have noticed, and of others similar in
character, upon the social and moral, as well as the purely economical,
interests of the people of the Netherlands, has induced me to describe them
more in detail than the general purpose of this volume may be thought to
justify; but if we consider them simply from a geographical point of view,
we shall find that they are possessed of no small importance as
modifications of the natural condition of terrestrial surface. There is good
reason to believe that before the establishment of a partially civilized race
upon the territory now occupied by Dutch, Frisic, and Low German
communities, the grounds not exposed to inundation were overgrown with
dense woods; that the lowlands between these forests and the sea-coasts
were marshes, covered and partially solidified by a thick matting of peat-
plants and shrubs interspersed with trees; and that even the sand-dunes of
the shore were protected by a vegetable growth which, in a great measure,
prevented the drifting and translocation of them.
The present causes of river and coast erosion existed, indeed, at the
period in question; but some of them must have acted with less intensity,
there were strong natural safeguards against the influence of marine and
fresh-water currents, and the conflicting tendencies had arrived at a
condition of approximate equilibrium, which permitted but slow and
gradual changes in the face of nature. The destruction of the forests around
the sources and along the valleys of the rivers by man gave them a more
torrential character. The felling of the trees, and the extirpation of the
shrubbery upon the fens by domestic cattle, deprived the surface of its
cohesion and consistence, and the cutting of peat for fuel opened cavities in
it, which, filling at once with water, rapidly extended themselves by
abrasion of their borders, and finally enlarged to pools, lakes, and gulfs, like
Page 535
the Lake of Haarlem and the northern part of the Zuiderzee. The cutting of
the wood and the depasturing of the grasses upon the sand-dunes converted
them from solid bulwarks against the ocean to loose accumulations of dust,
which every sea-breeze drove farther landward, burying, perhaps, fertile
soil and choking up water-courses on one side, and exposing the coast to
erosion by the sea upon the other.
Geographical Effect of Physical Improvements in the Netherlands.
The changes which human action has produced within twenty centuries
in the Netherlands and the neighboring provinces, are, certainly of no small
geographical importance, considered simply as a direct question of loss and
gain of territory. They have also, as we shall see hereafter, undoubtedly
been attended with some climatic consequences, they have exercised a great
influence on the spontaneous animal and vegetable life of this region, and
they cannot have failed to produce effects upon tidal and other oceanic
currents, the range of which may be very extensive. The force of the tidal
wave, the height to which it rises, the direction of its currents, and, in fact,
all the phenomena which characterize it, as well as all the effects it
produces, depend as much upon the configuration of the coast it washes,
and the depth of water, and form of bottom near the shore, as upon the
attraction which occasions it. Every one of the terrestrial conditions which
affect the character of tidal and other marine currents has been very sensibly
modified by the operations I have described, and on this coast, at least, man
has acted almost as powerfully on the physical geography of the sea as on
that of the land. [Footnote: See, on the influence of the artificial
modification of the coast-line on tides and other marine currents, Staring,
De Bodem van Nederland, i., p. 279.]
Ancient Hydraulic Works.
the wood and the depasturing of the grasses upon the sand-dunes converted
them from solid bulwarks against the ocean to loose accumulations of dust,
which every sea-breeze drove farther landward, burying, perhaps, fertile
soil and choking up water-courses on one side, and exposing the coast to
erosion by the sea upon the other.
Geographical Effect of Physical Improvements in the Netherlands.
The changes which human action has produced within twenty centuries
in the Netherlands and the neighboring provinces, are, certainly of no small
geographical importance, considered simply as a direct question of loss and
gain of territory. They have also, as we shall see hereafter, undoubtedly
been attended with some climatic consequences, they have exercised a great
influence on the spontaneous animal and vegetable life of this region, and
they cannot have failed to produce effects upon tidal and other oceanic
currents, the range of which may be very extensive. The force of the tidal
wave, the height to which it rises, the direction of its currents, and, in fact,
all the phenomena which characterize it, as well as all the effects it
produces, depend as much upon the configuration of the coast it washes,
and the depth of water, and form of bottom near the shore, as upon the
attraction which occasions it. Every one of the terrestrial conditions which
affect the character of tidal and other marine currents has been very sensibly
modified by the operations I have described, and on this coast, at least, man
has acted almost as powerfully on the physical geography of the sea as on
that of the land. [Footnote: See, on the influence of the artificial
modification of the coast-line on tides and other marine currents, Staring,
De Bodem van Nederland, i., p. 279.]
Ancient Hydraulic Works.
Page 536
The hydraulic works of the Netherlands and of the neighboring states are
of such magnitude that—with the exception of the dikes of the Mississippi
—they quite throw into the shade all other known artificial arrangements
for defending the land against the encroachments of the rivers and the sea,
and for reclaiming to the domain of agriculture and civilization soil long
covered by the waters. But although the recovery and protection of lands
flooded by the sea seems to be an art wholly of Netherlandish origin, we
have abundant evidence that, in ancient as well as in comparatively modern
times, great enterprises more or less analogous in character have been
successfully undertaken, both in inland Europe and in the less familiar
countries of the East.
In many cases no historical record remains to inform us when or by
whom such works were constructed. The Greeks and Romans, the latter
especially, were more inclined to undertake and carry out stupendous
material enterprises than to boast of them; and many of the grandest and
most important constructions of those nations are absolutely unnoticed by
contemporary annalists, and are first mentioned by writers living after all
knowledge of the epochs of the projectors of these works had perished.
Thus the aqueduct known as the Pont du Gard, near Nimes, which, though
not surpassing in volume or in probable cost other analogous constructions
of ancient and of modern ages, is yet among the most majestic and
imposing remains of ancient civil architecture, is not so much as spoken of
by any Roman author, [Footnote: One reason for the silence of Roman
writers in respect to great material improvements which had no immediate
relation to military or political objects, is doubtless the contempt in which
mechanical operations and mechanical contrivances were held by that
nation of spoilers. Even the engineer, upon whose skill the attack or defence
of a great city depended, was only praefectus fabrum, the master-artisan,
and had no military rank or command. This prejudice continued to a late
of such magnitude that—with the exception of the dikes of the Mississippi
—they quite throw into the shade all other known artificial arrangements
for defending the land against the encroachments of the rivers and the sea,
and for reclaiming to the domain of agriculture and civilization soil long
covered by the waters. But although the recovery and protection of lands
flooded by the sea seems to be an art wholly of Netherlandish origin, we
have abundant evidence that, in ancient as well as in comparatively modern
times, great enterprises more or less analogous in character have been
successfully undertaken, both in inland Europe and in the less familiar
countries of the East.
In many cases no historical record remains to inform us when or by
whom such works were constructed. The Greeks and Romans, the latter
especially, were more inclined to undertake and carry out stupendous
material enterprises than to boast of them; and many of the grandest and
most important constructions of those nations are absolutely unnoticed by
contemporary annalists, and are first mentioned by writers living after all
knowledge of the epochs of the projectors of these works had perished.
Thus the aqueduct known as the Pont du Gard, near Nimes, which, though
not surpassing in volume or in probable cost other analogous constructions
of ancient and of modern ages, is yet among the most majestic and
imposing remains of ancient civil architecture, is not so much as spoken of
by any Roman author, [Footnote: One reason for the silence of Roman
writers in respect to great material improvements which had no immediate
relation to military or political objects, is doubtless the contempt in which
mechanical operations and mechanical contrivances were held by that
nation of spoilers. Even the engineer, upon whose skill the attack or defence
of a great city depended, was only praefectus fabrum, the master-artisan,
and had no military rank or command. This prejudice continued to a late
Page 537
period in the Middle Ages, and the chiefs of artillery were equally without
grade or title as soldiers.
"The occupations of all artisans," says Cicero, "are base, and the shop can
have nothing of the respectable." De Officiis, 1, i., 42. The position of the
surgeon relatively to the physician, in England, is a remnant of the same
prejudice, which still survives in full vigor in Italy, with regard to both trade
and industry. See p. 6, ante.] and we are in absolute ignorance of the age or
the construction of the remarkable tunnel cut to drain Lake Copais in
Boeotia. This lake, now reduced by sedimentary deposit and the growth of
aquatic and semi-aquatic vegetation to the condition of a marsh, was
originally partially drained by natural subterranean outlets in the underlying
limestone rock, many of which still exist. But these emissaries, or
katavothra, as they are called in both ancient and modern Greek, were
insufficient for the discharge of the water, and besides, they were constantly
liable to be choked by earth and vegetables, and in such cases the lake rose
to a height which produced much injury. To remedy this evil and secure a
great accession of fertile soil, at some period anterior to the existence of a
written literature in Greece and ages before the time of any prose author
whose works have come down to us, two tunnels, one of them four miles
long, and of course not inferior to the Torlonian emissary in length, were
cut through the solid rock, and may still be followed throughout their whole
extent. They were repaired in the time of Alexander the Great, in the fourth
century before Christ, and their date was at that time traditionally referred
to the reign of rulers who lived as early as the period of the Trojan war.
One of the best known hydraulic works of the Romans is the tunnel
which serves to discharge the surplus waters of the Lake of Albano, about
fourteen miles from Rome. This lake, about six miles in circuit, occupies
one of the craters of an extinct volcanic range, and the surface of its waters
is about nine hundred feet above the sea. It is fed by rivulets and
grade or title as soldiers.
"The occupations of all artisans," says Cicero, "are base, and the shop can
have nothing of the respectable." De Officiis, 1, i., 42. The position of the
surgeon relatively to the physician, in England, is a remnant of the same
prejudice, which still survives in full vigor in Italy, with regard to both trade
and industry. See p. 6, ante.] and we are in absolute ignorance of the age or
the construction of the remarkable tunnel cut to drain Lake Copais in
Boeotia. This lake, now reduced by sedimentary deposit and the growth of
aquatic and semi-aquatic vegetation to the condition of a marsh, was
originally partially drained by natural subterranean outlets in the underlying
limestone rock, many of which still exist. But these emissaries, or
katavothra, as they are called in both ancient and modern Greek, were
insufficient for the discharge of the water, and besides, they were constantly
liable to be choked by earth and vegetables, and in such cases the lake rose
to a height which produced much injury. To remedy this evil and secure a
great accession of fertile soil, at some period anterior to the existence of a
written literature in Greece and ages before the time of any prose author
whose works have come down to us, two tunnels, one of them four miles
long, and of course not inferior to the Torlonian emissary in length, were
cut through the solid rock, and may still be followed throughout their whole
extent. They were repaired in the time of Alexander the Great, in the fourth
century before Christ, and their date was at that time traditionally referred
to the reign of rulers who lived as early as the period of the Trojan war.
One of the best known hydraulic works of the Romans is the tunnel
which serves to discharge the surplus waters of the Lake of Albano, about
fourteen miles from Rome. This lake, about six miles in circuit, occupies
one of the craters of an extinct volcanic range, and the surface of its waters
is about nine hundred feet above the sea. It is fed by rivulets and
Page 538
subterranean springs originating in the Alban Mount, or Monte Cavo, the
most elevated peak of the volcanic group just mentioned, which rises to the
height of about three thousand feet. At present the lake has no discoverable
natural outlet, and it is not known that the water ever stood at such a height
as to flow regularly over the lip of the crater. It seems that at the earliest
period of which we have any authentic memorials, its level was usually kept
by evaporation, or by discharge through subterranean channels,
considerably below the rim of the basin which encompassed it, but in the
year 397 B.C., the water, either from the obstruction of such channels, or in
consequence of increased supplies from unknown sources, rose to such a
height as to flow over the edge of the crater, and threaten inundation to the
country below by bursting through its walls. To obviate this danger, a tunnel
for carrying off the water was pierced at a level much below the height to
which it had risen. This gallery, cut entirely with the chisel through the rock
for a distance of six thousand feet, or nearly a mile and one-seventh, is still
in so good condition as to serve its original purpose. The fact that this work
was contemporaneous with the siege of Veii, has given to ancient annalists
occasion to connect the two events, but modern critics are inclined to reject
Livy's account of the matter, as one of the many improbable fables which
disfigure the pages of that historian. It is, however, repeated by Cicero and
by Dionysius of Halicarnassus, and it is by no means impossible that, in an
age when priests and soothsayers monopolized both the arts of natural
magic and the little which yet existed of physical science, the Government
of Rome, by their aid, availed itself at once of the superstition and of the
military ardor of its citizens to obtain their sanction to an enterprise which
sounder arguments might not have induced them to approve.
Still more remarkable is the tunnel cut by the Emperor Claudius to drain
the Lake Fucinus, now Lago di Celano, in the former Neapolitan territory,
about fifty miles eastward of Rome. This lake, as far as its history is known,
has varied very considerably in its dimensions at different periods,
most elevated peak of the volcanic group just mentioned, which rises to the
height of about three thousand feet. At present the lake has no discoverable
natural outlet, and it is not known that the water ever stood at such a height
as to flow regularly over the lip of the crater. It seems that at the earliest
period of which we have any authentic memorials, its level was usually kept
by evaporation, or by discharge through subterranean channels,
considerably below the rim of the basin which encompassed it, but in the
year 397 B.C., the water, either from the obstruction of such channels, or in
consequence of increased supplies from unknown sources, rose to such a
height as to flow over the edge of the crater, and threaten inundation to the
country below by bursting through its walls. To obviate this danger, a tunnel
for carrying off the water was pierced at a level much below the height to
which it had risen. This gallery, cut entirely with the chisel through the rock
for a distance of six thousand feet, or nearly a mile and one-seventh, is still
in so good condition as to serve its original purpose. The fact that this work
was contemporaneous with the siege of Veii, has given to ancient annalists
occasion to connect the two events, but modern critics are inclined to reject
Livy's account of the matter, as one of the many improbable fables which
disfigure the pages of that historian. It is, however, repeated by Cicero and
by Dionysius of Halicarnassus, and it is by no means impossible that, in an
age when priests and soothsayers monopolized both the arts of natural
magic and the little which yet existed of physical science, the Government
of Rome, by their aid, availed itself at once of the superstition and of the
military ardor of its citizens to obtain their sanction to an enterprise which
sounder arguments might not have induced them to approve.
Still more remarkable is the tunnel cut by the Emperor Claudius to drain
the Lake Fucinus, now Lago di Celano, in the former Neapolitan territory,
about fifty miles eastward of Rome. This lake, as far as its history is known,
has varied very considerably in its dimensions at different periods,
Page 539
according to the character of the seasons. It lies 2,200 feet above the sea,
and has no visible outlet, but was originally either drained by natural
subterranean conduits, or kept within certain extreme limits by evaporation.
In years of uncommon moisture it spread over the adjacent soil and
destroyed the crops; in dry seasons it retreated, and produced epidemic
disease by poisonous exhalations from the decay of vegetable and animal
matter upon its exposed bed. Julius Caesar had proposed the construction of
a tunnel to lower the bed of the lake and provide a regular discharge for its
waters, but the enterprise was not actually undertaken until the reign of
Claudius, when—after a temporary failure, from errors in levelling by the
engineers, as was pretended at the time, or, as now appears certain, in
consequence of frauds by the contractors in the execution of the work—it
was at least partially completed. From this imperfect construction, it soon
got out of repair, but was restored by Hadrian, and is said to have answered
its design for some centuries. [Footnote: The fact alluded to in a note on p.
97, ante, that since the opening of a communication between Lake Celano
and the Garigliano by the works noticed in the text, fish, of species common
in the lake, but not previously found in the river, have become naturalized
in the Garigliano, is a circumstance of some weight as evidence that the
emissary was not actually open in ancient times; for if the waters had been
really connected, the fish of the lake would naturally have followed the
descending current and established themselves in the river as they have
done now.] In the barbarism which followed the downfall of the empire, it
again fell into decay, and though numerous attempts were made to repair it
during the Middle Ages, no tolerable success seems to have attended any of
these efforts until the present generation.
Draining of Lake Celano by Prince Torlonia.
and has no visible outlet, but was originally either drained by natural
subterranean conduits, or kept within certain extreme limits by evaporation.
In years of uncommon moisture it spread over the adjacent soil and
destroyed the crops; in dry seasons it retreated, and produced epidemic
disease by poisonous exhalations from the decay of vegetable and animal
matter upon its exposed bed. Julius Caesar had proposed the construction of
a tunnel to lower the bed of the lake and provide a regular discharge for its
waters, but the enterprise was not actually undertaken until the reign of
Claudius, when—after a temporary failure, from errors in levelling by the
engineers, as was pretended at the time, or, as now appears certain, in
consequence of frauds by the contractors in the execution of the work—it
was at least partially completed. From this imperfect construction, it soon
got out of repair, but was restored by Hadrian, and is said to have answered
its design for some centuries. [Footnote: The fact alluded to in a note on p.
97, ante, that since the opening of a communication between Lake Celano
and the Garigliano by the works noticed in the text, fish, of species common
in the lake, but not previously found in the river, have become naturalized
in the Garigliano, is a circumstance of some weight as evidence that the
emissary was not actually open in ancient times; for if the waters had been
really connected, the fish of the lake would naturally have followed the
descending current and established themselves in the river as they have
done now.] In the barbarism which followed the downfall of the empire, it
again fell into decay, and though numerous attempts were made to repair it
during the Middle Ages, no tolerable success seems to have attended any of
these efforts until the present generation.
Draining of Lake Celano by Prince Torlonia.
Page 540
Works have been some years in progress and are now substantially
completed, at a cost of about six millions of dollars, for restoring, or rather
enlarging and rebuilding, this ancient tunnel, upon a scale of grandeur
which does infinite honor to the liberality and public spirit of the projectors,
and with an ingenuity of design and a constructive skill which reflect the
highest credit upon the professional ability of the engineers who have
planned the works and directed their execution. The length of the Roman
tunnel was 18,634 feet, or rather more than three miles and a half, but as the
new emissary is designed to drain the lake to the bottom, it must be
continued to the lowest part of the basin. It will consequently have a length
of not less than 21,000 feet, and, of course, is among the longest
subterranean galleries in Europe. Many curious particulars in the design and
execution of the original work have been observed in the course of the
restoration, but these cannot here be noticed. The difference between the
lowest and highest known levels of the surface of the lake is rather more
than forty feet and the difference between the areas covered by water at
these levels is not less than nine thousand acres. The complete drainage of
the lake, including the ground occasionally flooded, will recover, for
agricultural occupation, and permanently secure from inundation, about
forty-two thousand acres of as fertile soil as any in Italy. [Footnote: Springs
rising in the bottom of the lake have materially impeded the process of
drainage, and some engineers believe that they will render the complete
discharge of the waters impossible. It appears that the earthy and rocky
strata underlying the lake are extremely porous, and that the ground already
laid dry on the surface absorbs an abnormally large proportion of the
precipitation upon it. These strata, therefore, constitute a reservoir which
contributes to maintain the spring fed chiefly, no doubt, by underground
channels from the neighboring mountains. But it is highly probable that,
after a certain time, the process of natural desiccation noticed in note to p.
20, ante, will drain this reservoir, and the entire removal of the surface-
completed, at a cost of about six millions of dollars, for restoring, or rather
enlarging and rebuilding, this ancient tunnel, upon a scale of grandeur
which does infinite honor to the liberality and public spirit of the projectors,
and with an ingenuity of design and a constructive skill which reflect the
highest credit upon the professional ability of the engineers who have
planned the works and directed their execution. The length of the Roman
tunnel was 18,634 feet, or rather more than three miles and a half, but as the
new emissary is designed to drain the lake to the bottom, it must be
continued to the lowest part of the basin. It will consequently have a length
of not less than 21,000 feet, and, of course, is among the longest
subterranean galleries in Europe. Many curious particulars in the design and
execution of the original work have been observed in the course of the
restoration, but these cannot here be noticed. The difference between the
lowest and highest known levels of the surface of the lake is rather more
than forty feet and the difference between the areas covered by water at
these levels is not less than nine thousand acres. The complete drainage of
the lake, including the ground occasionally flooded, will recover, for
agricultural occupation, and permanently secure from inundation, about
forty-two thousand acres of as fertile soil as any in Italy. [Footnote: Springs
rising in the bottom of the lake have materially impeded the process of
drainage, and some engineers believe that they will render the complete
discharge of the waters impossible. It appears that the earthy and rocky
strata underlying the lake are extremely porous, and that the ground already
laid dry on the surface absorbs an abnormally large proportion of the
precipitation upon it. These strata, therefore, constitute a reservoir which
contributes to maintain the spring fed chiefly, no doubt, by underground
channels from the neighboring mountains. But it is highly probable that,
after a certain time, the process of natural desiccation noticed in note to p.
20, ante, will drain this reservoir, and the entire removal of the surface-
Page 541
water will then become practicable.] The ground already dry enough for
cultivation furnishes occupation and a livelihood for a population of 16,000
persons, and it is thought that this number will be augmented to 40,000
when the drainage shall be completely effected.
The new tunnel follows the line of the Claudian emissary—which though
badly executed was admirably engineered—but its axis is at a somewhat
lower level than that of the old gallery, and its cross-section is about two
hundred and fifteen square feet, allowing a discharge of about 2,400 cubic
feet to the second, while the Roman work had a cross-section of only one
hundred and two square feet, with a possible delivery of 424 cubic feet to
the second.
In consequence of the nature of the rock and of the soil, which had been
loosened and shattered by the falling in of much of the crown and walls of
the old tunnel—every stone of which it was necessary to remove in the
progress of the work—and the great head of water in the lake from
unusually wet seasons, the technical difficulties to be surmounted were
most baffling and discouraging in character, and of such extreme gravity
that it may well be doubted whether the art of engineering has anywhere
triumphed over more serious obstacles. This great "victory of peace"—
probably the grandest work of physical improvement ever effected by the
means, the energy, and the munificence of a single individual—is of no
small geographical and economical, as well as sanitary, importance, but it
has a still higher moral value as an almost unique example of the exercise
of public spirit, courage, and perseverance in the accomplishment of a noble
and beneficent enterprise by a private citizen. [Footnote: The draining of
Lake Celano was undertaken by a company, but Prince Alessandro Torlonia
of Rome bought up the interest of all the shareholders and has executed the
entire work at his own private expense. Montricher, the celebrated
constructor of the great aqueduct of Marseilles, was the engineer who
cultivation furnishes occupation and a livelihood for a population of 16,000
persons, and it is thought that this number will be augmented to 40,000
when the drainage shall be completely effected.
The new tunnel follows the line of the Claudian emissary—which though
badly executed was admirably engineered—but its axis is at a somewhat
lower level than that of the old gallery, and its cross-section is about two
hundred and fifteen square feet, allowing a discharge of about 2,400 cubic
feet to the second, while the Roman work had a cross-section of only one
hundred and two square feet, with a possible delivery of 424 cubic feet to
the second.
In consequence of the nature of the rock and of the soil, which had been
loosened and shattered by the falling in of much of the crown and walls of
the old tunnel—every stone of which it was necessary to remove in the
progress of the work—and the great head of water in the lake from
unusually wet seasons, the technical difficulties to be surmounted were
most baffling and discouraging in character, and of such extreme gravity
that it may well be doubted whether the art of engineering has anywhere
triumphed over more serious obstacles. This great "victory of peace"—
probably the grandest work of physical improvement ever effected by the
means, the energy, and the munificence of a single individual—is of no
small geographical and economical, as well as sanitary, importance, but it
has a still higher moral value as an almost unique example of the exercise
of public spirit, courage, and perseverance in the accomplishment of a noble
and beneficent enterprise by a private citizen. [Footnote: The draining of
Lake Celano was undertaken by a company, but Prince Alessandro Torlonia
of Rome bought up the interest of all the shareholders and has executed the
entire work at his own private expense. Montricher, the celebrated
constructor of the great aqueduct of Marseilles, was the engineer who
Page 542
designed and partly carried out the plans, and after his lamentable death the
work has been directed with equal ability by Bermont and Brisse.—See
Leon De Rothou, Prosciugamento del Lago Fucino, 8vo. Firenza, 1871.]
The crater-lake of Nemi, in the same volcanic region as that of Albano, is
also drained by a subterranean tunnel probably of very ancient construction,
and the Valle-Riccia appears to have once been the basin of a lake long
since laid dry, but whether by the bursting of its banks or by human art we
are unable to say.
The success of the Lake Celano tunnel has suggested other like
improvements in Italy. A gallery has been cut, under circumstances of great
difficulty, to drain Lake Agnano near Naples, and a project for the execution
of a similar operation on the Lake of Perugia, the ancient Trasimenus,
which covers more than 40,000 acres, is under discussion.
Many similar enterprises have been conceived and executed in modern
times, both for the purpose of reclaiming land covered by water and for
sanitary reasons. [Footnote: A considerable work of this character is
mentioned by Captain Gilliss as having been executed in Chili, a country to
which we should hardly have looked for an improvement of such a nature.
The Lake Taguataga was partially drained by cutting through a narrow ridge
of land, not at the natural outlet, but upon one side of the lake, and eight
thousand acres of land covered by it were gained for cultivation.—U. S.
Naval Astronomical Expedition to the Southern Hemisphere, i., pp. 16, 17.
Lake Balaton and the Neusiedler Sea in Hungary have lately been, at
least partially, drained.
The lakes of Neuchatel, Bienne, and Morat, in Switzerland, have been
connected and the common level of all of them lowered about four feet. The
works now in operation will produce, in the course of the year 1874, a
work has been directed with equal ability by Bermont and Brisse.—See
Leon De Rothou, Prosciugamento del Lago Fucino, 8vo. Firenza, 1871.]
The crater-lake of Nemi, in the same volcanic region as that of Albano, is
also drained by a subterranean tunnel probably of very ancient construction,
and the Valle-Riccia appears to have once been the basin of a lake long
since laid dry, but whether by the bursting of its banks or by human art we
are unable to say.
The success of the Lake Celano tunnel has suggested other like
improvements in Italy. A gallery has been cut, under circumstances of great
difficulty, to drain Lake Agnano near Naples, and a project for the execution
of a similar operation on the Lake of Perugia, the ancient Trasimenus,
which covers more than 40,000 acres, is under discussion.
Many similar enterprises have been conceived and executed in modern
times, both for the purpose of reclaiming land covered by water and for
sanitary reasons. [Footnote: A considerable work of this character is
mentioned by Captain Gilliss as having been executed in Chili, a country to
which we should hardly have looked for an improvement of such a nature.
The Lake Taguataga was partially drained by cutting through a narrow ridge
of land, not at the natural outlet, but upon one side of the lake, and eight
thousand acres of land covered by it were gained for cultivation.—U. S.
Naval Astronomical Expedition to the Southern Hemisphere, i., pp. 16, 17.
Lake Balaton and the Neusiedler Sea in Hungary have lately been, at
least partially, drained.
The lakes of Neuchatel, Bienne, and Morat, in Switzerland, have been
connected and the common level of all of them lowered about four feet. The
works now in operation will produce, in the course of the year 1874, a
Page 543
further depression of four feet, and recover for agricultural use more than
twelve thousand acres of fertile soil.] They are sometimes attended with
wholly unexpected evils, as, for example, in the case of Barton Pond, in
Vermont, and in that of a lake near Ragunda in Sweden, already mentioned
on a former page. Another still less obvious consequence of the withdrawal
of the waters has occasionally been observed in these operations. The
hydrostatic force with which the water, in virtue of its specific gravity,
presses against the banks that confine it, has a tendency to sustain them
whenever their composition and texture are not such as to expose them to
softening and dissolution by the infiltration of the water. If, then, the slope
of the banks is considerable, or if the earth of which they are composed
rests on a smooth and slippery stratum inclining towards the bed of the lake,
they are liable to fall or slide forward when the mechanical support of the
water is removed, and this sometimes happens on a considerable scale. A
few years ago the surface of the Lake of Lungern, in the Canton of
Unterwalden, in Switzerland, was lowered by driving a tunnel about a
quarter of a mile long through the narrow ridge, called the Kaiserstuhl,
which forms a barrier at the north end of the basin. When the water was
drawn off, the banks, which are steep, cracked and burst, several acres of
ground slid down as low as the water receded, and even the whole village of
Lungern was thought to be in no small danger. [Footnote: In the course of
the year 1864 there were slides of the banks of the Lake of Como, and in
one case the grounds of a villa near the water suffered a considerable
displacement. More important slips occurred at Fesiolo on the shore of
Lago Maggiore in 1867 and 1869, and on the Lake of Orta in 1868. These
occurrences excited some apprehensions in regard to the possible effects of
projects then under discussion for lowering the level of some of the Italian
lakes, to obtain an increased supply of water for irrigation and as a
mechanical power, but as it was not proposed to depress the surface below
twelve thousand acres of fertile soil.] They are sometimes attended with
wholly unexpected evils, as, for example, in the case of Barton Pond, in
Vermont, and in that of a lake near Ragunda in Sweden, already mentioned
on a former page. Another still less obvious consequence of the withdrawal
of the waters has occasionally been observed in these operations. The
hydrostatic force with which the water, in virtue of its specific gravity,
presses against the banks that confine it, has a tendency to sustain them
whenever their composition and texture are not such as to expose them to
softening and dissolution by the infiltration of the water. If, then, the slope
of the banks is considerable, or if the earth of which they are composed
rests on a smooth and slippery stratum inclining towards the bed of the lake,
they are liable to fall or slide forward when the mechanical support of the
water is removed, and this sometimes happens on a considerable scale. A
few years ago the surface of the Lake of Lungern, in the Canton of
Unterwalden, in Switzerland, was lowered by driving a tunnel about a
quarter of a mile long through the narrow ridge, called the Kaiserstuhl,
which forms a barrier at the north end of the basin. When the water was
drawn off, the banks, which are steep, cracked and burst, several acres of
ground slid down as low as the water receded, and even the whole village of
Lungern was thought to be in no small danger. [Footnote: In the course of
the year 1864 there were slides of the banks of the Lake of Como, and in
one case the grounds of a villa near the water suffered a considerable
displacement. More important slips occurred at Fesiolo on the shore of
Lago Maggiore in 1867 and 1869, and on the Lake of Orta in 1868. These
occurrences excited some apprehensions in regard to the possible effects of
projects then under discussion for lowering the level of some of the Italian
lakes, to obtain an increased supply of water for irrigation and as a
mechanical power, but as it was not proposed to depress the surface below
Page 544
the lowest natural low-water level, there seems to have been little ground
for the fears expressed.
See, for important observations on the character and probable results of
these projects, Tagliasecchi, Nostizie etc. del Canali dell' Alta Lombardia,
Milano, 1871.
Jacini says: "A large proportion of the water of the lakes, instead of
discharging itself by the Ticino, the Adda, the Oglio, the Mincio, filters
through the silicious strata which underlie the hills, and follows
subterranean channels to the plain, where it collects in the fontanili, and
being thence conducted into the canals of irrigation, becomes a source of
great fertility."—La Proprieta Fondiaria, etc., p.144. The quantity of water
escaping from the lakes by infiltration depends much on the hydrostatic
pressure on the bottom and the walls of the lake-basins, and consequently
the depression of the lake surface, diminishing this pressure, would
diminish the infiltration. Hence it is possible that the lowering of the level
of these lakes would manifest itself in a decreased supply of water for the
springs, fontanili, and wells of Lombardy.]
Mountain Lakes.
Other inconveniences of a very serious character have often resulted
from the natural wearing down, or, much more frequently, the imprudent
destruction, of the barriers which confine mountain lakes. In their natural
condition, such basins serve both to receive and retain the rocks and other
detritus brought down by the torrents which empty into them, and to check
the impetus of the rushing waters by bringing them to a temporary pause;
but if the outlets are lowered so as to drain the reservoirs, the torrents
continue their rapid flow through the ancient bed of the basins, and carry
for the fears expressed.
See, for important observations on the character and probable results of
these projects, Tagliasecchi, Nostizie etc. del Canali dell' Alta Lombardia,
Milano, 1871.
Jacini says: "A large proportion of the water of the lakes, instead of
discharging itself by the Ticino, the Adda, the Oglio, the Mincio, filters
through the silicious strata which underlie the hills, and follows
subterranean channels to the plain, where it collects in the fontanili, and
being thence conducted into the canals of irrigation, becomes a source of
great fertility."—La Proprieta Fondiaria, etc., p.144. The quantity of water
escaping from the lakes by infiltration depends much on the hydrostatic
pressure on the bottom and the walls of the lake-basins, and consequently
the depression of the lake surface, diminishing this pressure, would
diminish the infiltration. Hence it is possible that the lowering of the level
of these lakes would manifest itself in a decreased supply of water for the
springs, fontanili, and wells of Lombardy.]
Mountain Lakes.
Other inconveniences of a very serious character have often resulted
from the natural wearing down, or, much more frequently, the imprudent
destruction, of the barriers which confine mountain lakes. In their natural
condition, such basins serve both to receive and retain the rocks and other
detritus brought down by the torrents which empty into them, and to check
the impetus of the rushing waters by bringing them to a temporary pause;
but if the outlets are lowered so as to drain the reservoirs, the torrents
continue their rapid flow through the ancient bed of the basins, and carry
Page 545
down with them the sand and gravel with which they are charged, instead of
depositing their burden as before in the still waters of the lakes.
It is a common opinion in America that the river meadows, bottoms, or
intervales, as they are popularly called, are generally the beds of ancient
lakes which have burst their barriers and left running currents in their place.
It was shown by Dr.
Dwight, many years ago, that this is very far from being universally true;
but there is no doubt that mountain lakes were of much more frequent
occurrence in primitive than in modern geography, and there are many
chains of such still existing in regions where man has yet little disturbed the
original features of the earth. In the long valleys of the Adirondack range in
Northern New York, and in the mountainous parts of Maine, eight, ten, and
even more lakes and lakelets are sometimes found in succession, each
emptying into the next lower pool, and so all at last into some considerable
river. When the mountain slopes which supply these basins shall be stripped
of their woods, the augmented swelling of the lakes will break down their
barriers, their waters will run off, and the valleys will present successions of
flats with rivers running through them, instead of chains of lakes connected
by natural canals.
A similar state of things seems to have existed in the ancient geography
of France. "Nature," says Lavergne, "has not excavated on the flanks of our
Alps reservoirs as magnificent as those of Lombardy; she had, however,
constructed smaller but more numerous lakes, which the improvidence of
man has permitted to disappear. Auguste de Gasparin demonstrated more
than thirty years ago that many natural dikes formerly existed in the
mountain valleys, which have been swept away by the waters." [Footnote:
Economie Rurale de la France, p. 289.]
depositing their burden as before in the still waters of the lakes.
It is a common opinion in America that the river meadows, bottoms, or
intervales, as they are popularly called, are generally the beds of ancient
lakes which have burst their barriers and left running currents in their place.
It was shown by Dr.
Dwight, many years ago, that this is very far from being universally true;
but there is no doubt that mountain lakes were of much more frequent
occurrence in primitive than in modern geography, and there are many
chains of such still existing in regions where man has yet little disturbed the
original features of the earth. In the long valleys of the Adirondack range in
Northern New York, and in the mountainous parts of Maine, eight, ten, and
even more lakes and lakelets are sometimes found in succession, each
emptying into the next lower pool, and so all at last into some considerable
river. When the mountain slopes which supply these basins shall be stripped
of their woods, the augmented swelling of the lakes will break down their
barriers, their waters will run off, and the valleys will present successions of
flats with rivers running through them, instead of chains of lakes connected
by natural canals.
A similar state of things seems to have existed in the ancient geography
of France. "Nature," says Lavergne, "has not excavated on the flanks of our
Alps reservoirs as magnificent as those of Lombardy; she had, however,
constructed smaller but more numerous lakes, which the improvidence of
man has permitted to disappear. Auguste de Gasparin demonstrated more
than thirty years ago that many natural dikes formerly existed in the
mountain valleys, which have been swept away by the waters." [Footnote:
Economie Rurale de la France, p. 289.]
Page 546
Many Alpine valleys in Switzerland and Italy present unquestionable
evidence of the former existence of chains of lakes in their basins, and this
may be regarded as a general fact in regard to the primitive topography of
mountainous regions. Where the forests have not been destroyed, the lakes
remain as characteristic features of the geographical surface. But when the
woods are felled, these reservoirs are sooner or later filled up by wash from
the shores, and of course disappear. Geologists have calculated the period
when the bottom of the Lake of Geneva will be levelled up and its outlet
worn down. The Rhone will then flow, in an unbroken current, from its
source in the great Rhone glacier to the Mediterranean Sea.
Draining of Swamps.
The reclamation of bogs and swamps by draining off the surface-water is
doubtless much more ancient than the draining of lakes. The beneficial
results of the former mode of improvement are more unequivocal, and
balanced by fewer disadvantages, and, at the same time, the processes by
which it is effected are much simpler and more obvious. It has accordingly
been practised through the whole historical period, and in recent times
operations for this purpose have assumed a magnitude, and been attended
with economical as well as sanitary and geographical effects, which entitle
them to a high place in the efforts of man to ameliorate the natural
conditions of the soil he occupies.
The methods by which the draining of marshes is ordinarily
accomplished are too familiar, and examples of their successful
employment too frequent, to require description, and I shall content myself,
for the moment, with a brief notice of some recent operations of this sort
which are less generally known than their importance merits.
evidence of the former existence of chains of lakes in their basins, and this
may be regarded as a general fact in regard to the primitive topography of
mountainous regions. Where the forests have not been destroyed, the lakes
remain as characteristic features of the geographical surface. But when the
woods are felled, these reservoirs are sooner or later filled up by wash from
the shores, and of course disappear. Geologists have calculated the period
when the bottom of the Lake of Geneva will be levelled up and its outlet
worn down. The Rhone will then flow, in an unbroken current, from its
source in the great Rhone glacier to the Mediterranean Sea.
Draining of Swamps.
The reclamation of bogs and swamps by draining off the surface-water is
doubtless much more ancient than the draining of lakes. The beneficial
results of the former mode of improvement are more unequivocal, and
balanced by fewer disadvantages, and, at the same time, the processes by
which it is effected are much simpler and more obvious. It has accordingly
been practised through the whole historical period, and in recent times
operations for this purpose have assumed a magnitude, and been attended
with economical as well as sanitary and geographical effects, which entitle
them to a high place in the efforts of man to ameliorate the natural
conditions of the soil he occupies.
The methods by which the draining of marshes is ordinarily
accomplished are too familiar, and examples of their successful
employment too frequent, to require description, and I shall content myself,
for the moment, with a brief notice of some recent operations of this sort
which are less generally known than their importance merits.
Page 547
Within the present century more than half a million acres of swamp-land
have been drained and brought under cultivation in Hungary, and works are
in progress which will ultimately recover a still larger area for human use.
The most remarkable feature of these operations, and at the same time the
process which has been most immediately successful and remunerative, is
what is called in Europe the regulation of water-courses, and especially of
the River Theiss, on the lower course of which stream alone not less than
250,000 acres of pestilential and wholly unproductive marsh have been
converted into a healthful region of the most exuberant fertility.
The regulation of a river consists in straightening its channel by cutting
off bends, securing its banks from erosion by floods, and, where necessary,
by constructing embankments to confine the waters and prevent them from
overflowing and stagnating upon the low grounds which skirt their current.
In the course of the Theiss about sixty bends, including some of
considerable length, have been cut off, and dikes sufficient for securing the
land along its banks against inundation have been constructed.
Many thousand acres of land have been recently permanently improved
in Italy by the draining of swamps, and extensive operations have been
projected and commenced on the lower Rhone, and elsewhere in France,
with the same object. [Footnote: Very interesting and important
experiments, on the practicability of washing out the salt from seacoast
lands too highly impregnated with that mineral to be fit for cultivation, are
now in progress near the mouth of the Rhone, where millions of acres of
marshy soil can easily be recovered, if these experiments are successful.
See Duponchel, Traite d'Hydraulique et de Geologie agricoles. Paris,
1868, chap. xi. and xii.
In the neighborhood of Ferrara are pools and marshes covering nearly
two hundred square miles, or a surface more than equal to eight American
have been drained and brought under cultivation in Hungary, and works are
in progress which will ultimately recover a still larger area for human use.
The most remarkable feature of these operations, and at the same time the
process which has been most immediately successful and remunerative, is
what is called in Europe the regulation of water-courses, and especially of
the River Theiss, on the lower course of which stream alone not less than
250,000 acres of pestilential and wholly unproductive marsh have been
converted into a healthful region of the most exuberant fertility.
The regulation of a river consists in straightening its channel by cutting
off bends, securing its banks from erosion by floods, and, where necessary,
by constructing embankments to confine the waters and prevent them from
overflowing and stagnating upon the low grounds which skirt their current.
In the course of the Theiss about sixty bends, including some of
considerable length, have been cut off, and dikes sufficient for securing the
land along its banks against inundation have been constructed.
Many thousand acres of land have been recently permanently improved
in Italy by the draining of swamps, and extensive operations have been
projected and commenced on the lower Rhone, and elsewhere in France,
with the same object. [Footnote: Very interesting and important
experiments, on the practicability of washing out the salt from seacoast
lands too highly impregnated with that mineral to be fit for cultivation, are
now in progress near the mouth of the Rhone, where millions of acres of
marshy soil can easily be recovered, if these experiments are successful.
See Duponchel, Traite d'Hydraulique et de Geologie agricoles. Paris,
1868, chap. xi. and xii.
In the neighborhood of Ferrara are pools and marshes covering nearly
two hundred square miles, or a surface more than equal to eight American
Page 548
townships. Centrifugal steam-pumps, of 2,000 horse-power, capable of
discharging more than six hundred and fifty millions of gallons of water per
day have lately been constructed in England for draining these marshes.
This discharge is equal to an area of 640 acres, or a mile square, with nearly
three feet of water.] But there is probably no country where greater
improvements of this sort have either been lately effected, or are now in
course of accomplishment, than in our own. Not to speak of well-known
works on the New Jersey seacoast and the shores of Lake Michigan, the
people of the new State of California are engaging in this mode of subduing
nature with as much enterprise and energy as they have shown in the search
for gold. The Report of the Agricultural Department of the United States for
January, 1872, notices, with more or less detail, several highly successful
experiments in California in the way of swamp-drainage and securing land
from overflow, and it appears that not far from 200,000 acres have either
very recently undergone or will soon be subjected to this method of
improvement.
Agricultural Draining.
I have commenced this chapter with a description of the dikes and other
hydraulic works of the Netherland engineers, because both the immediate
and the remote results of such operations are more obvious and more easily
measured, though certainly not more important, than those of much older
and more widely diffused modes of resisting or directing the flow of waters,
which have been practised from remote antiquity in the interior of all
civilized countries. Draining and irrigation are habitually regarded as purely
agricultural processes, having little or no relation to technical geography;
but we shall find that they exert a powerful influence on soil, climate, and
animal and vegetable life, and may, therefore, justly claim to be regarded as
geographical elements.
discharging more than six hundred and fifty millions of gallons of water per
day have lately been constructed in England for draining these marshes.
This discharge is equal to an area of 640 acres, or a mile square, with nearly
three feet of water.] But there is probably no country where greater
improvements of this sort have either been lately effected, or are now in
course of accomplishment, than in our own. Not to speak of well-known
works on the New Jersey seacoast and the shores of Lake Michigan, the
people of the new State of California are engaging in this mode of subduing
nature with as much enterprise and energy as they have shown in the search
for gold. The Report of the Agricultural Department of the United States for
January, 1872, notices, with more or less detail, several highly successful
experiments in California in the way of swamp-drainage and securing land
from overflow, and it appears that not far from 200,000 acres have either
very recently undergone or will soon be subjected to this method of
improvement.
Agricultural Draining.
I have commenced this chapter with a description of the dikes and other
hydraulic works of the Netherland engineers, because both the immediate
and the remote results of such operations are more obvious and more easily
measured, though certainly not more important, than those of much older
and more widely diffused modes of resisting or directing the flow of waters,
which have been practised from remote antiquity in the interior of all
civilized countries. Draining and irrigation are habitually regarded as purely
agricultural processes, having little or no relation to technical geography;
but we shall find that they exert a powerful influence on soil, climate, and
animal and vegetable life, and may, therefore, justly claim to be regarded as
geographical elements.
Page 549
Superficial draining is a necessity in all lands newly reclaimed from the
forest. The face of the ground in the woods is never so regularly inclined as
to permit water to flow freely over it. There are, even on the hillsides, small
ridges depressions, partly belonging to the original distribution of the soil,
and partly occasioned by irregularities in the growth and deposit of
vegetable matter. These, in the husbandry of nature, serve as dams and
reservoirs to collect a larger supply of moisture than the spongy earth can at
once imbibe. Besides this, the vegetable mould is, even under the most
favorable circumstances, slow in parting with the humidity it has
accumulated under the protection of the woods, and the infiltration from
neighboring forests contributes to keep the soil of small clearings too wet
for the advantageous cultivation of artificial crops. For these reasons,
surface draining must have commenced with agriculture itself, and there is
probably no cultivated district, one may almost say no single field, which is
not provided with artificial arrangements for facilitating the escape of
superficial water, and thus carrying off moisture which, in the natural
condition of the earth, would have been imbibed by the soil.
All these processes belong to the incipient civilization of the ante-
historical periods, but the construction of subterranean channels for the
removal of infiltrated water marks ages and countries distinguished by a
great advance in agricultural theory and practice, a great accumulation of
pecuniary capital and a density of population which creates a ready demand
and a high price for all products of rural industry. Under draining, too,
would be most advantageous in damp and cool climates, where evaporation
is slow, and upon soils where the natural inclination of surface does not
promote a very rapid flow of the surface-waters. All the conditions required
to make this mode of rural improvement, if not absolutely necessary, at
least profitable, exist in Great Britain, and it is, therefore, very natural that
the wealthy and intelligent farmers of England should have carried this
forest. The face of the ground in the woods is never so regularly inclined as
to permit water to flow freely over it. There are, even on the hillsides, small
ridges depressions, partly belonging to the original distribution of the soil,
and partly occasioned by irregularities in the growth and deposit of
vegetable matter. These, in the husbandry of nature, serve as dams and
reservoirs to collect a larger supply of moisture than the spongy earth can at
once imbibe. Besides this, the vegetable mould is, even under the most
favorable circumstances, slow in parting with the humidity it has
accumulated under the protection of the woods, and the infiltration from
neighboring forests contributes to keep the soil of small clearings too wet
for the advantageous cultivation of artificial crops. For these reasons,
surface draining must have commenced with agriculture itself, and there is
probably no cultivated district, one may almost say no single field, which is
not provided with artificial arrangements for facilitating the escape of
superficial water, and thus carrying off moisture which, in the natural
condition of the earth, would have been imbibed by the soil.
All these processes belong to the incipient civilization of the ante-
historical periods, but the construction of subterranean channels for the
removal of infiltrated water marks ages and countries distinguished by a
great advance in agricultural theory and practice, a great accumulation of
pecuniary capital and a density of population which creates a ready demand
and a high price for all products of rural industry. Under draining, too,
would be most advantageous in damp and cool climates, where evaporation
is slow, and upon soils where the natural inclination of surface does not
promote a very rapid flow of the surface-waters. All the conditions required
to make this mode of rural improvement, if not absolutely necessary, at
least profitable, exist in Great Britain, and it is, therefore, very natural that
the wealthy and intelligent farmers of England should have carried this
Page 550
practice farther, and reaped a more abundant pecuniary return from it, than
those of any other country.
Besides superficial and subsoil drains, there is another method of
disposing of superfluous surface-water, which, however, can rarely be
practised, because the necessary conditions for its employment are not of
frequent occurrence. Whenever a tenacious water-holding stratum rests on a
loose, gravelly bed so situated as to admit of a free discharge of water from
or through it by means of the outcropping of the bed at a lower level, or of
deep-lying conduits leading to distant points of discharge, superficial waters
may be carried off by opening a passage for them through the impervious
into the permeable stratum. Thus, according to Bischof, as early as the time
of King Rene, in the first half of the fifteenth century, when subsoil
drainage was scarcely known, the plain of Paluns, near Marseilles, was laid
dry by boring, and Wittwer informs us that drainage is effected at Munich
by conducting the superfluous water into large excavations, from which it
filters through into a lower stratum of pebble and gravel lying a little above
the level of the river Isar. [Foonote: Physikalische Geographie, p. 288. This
method is now frequently employed in France. Details as to the processes
will be found in Mangon Pratique du Drainage, pp. 78 et seqq. Draining by
driving down stakes mentioned in a note in the chapter on the Woods, ante,
is a process of the same nature.
In the United States, large tracts of marshy ground, and even shallow
lakes of considerable extent, have been sufficiently drained not only for
pasturage but for cultivation, without resort to any special measures for
effecting that end. The ordinary processes of rural improvement in the
vicinity, such as felling woods upon and around such grounds, and the
construction of roads, the side ditches of which act as drains, over or near
them, aided now and then by the removal of a fallen tree or other accidental
obstruction in the beds of small streams which flow from them, often
those of any other country.
Besides superficial and subsoil drains, there is another method of
disposing of superfluous surface-water, which, however, can rarely be
practised, because the necessary conditions for its employment are not of
frequent occurrence. Whenever a tenacious water-holding stratum rests on a
loose, gravelly bed so situated as to admit of a free discharge of water from
or through it by means of the outcropping of the bed at a lower level, or of
deep-lying conduits leading to distant points of discharge, superficial waters
may be carried off by opening a passage for them through the impervious
into the permeable stratum. Thus, according to Bischof, as early as the time
of King Rene, in the first half of the fifteenth century, when subsoil
drainage was scarcely known, the plain of Paluns, near Marseilles, was laid
dry by boring, and Wittwer informs us that drainage is effected at Munich
by conducting the superfluous water into large excavations, from which it
filters through into a lower stratum of pebble and gravel lying a little above
the level of the river Isar. [Foonote: Physikalische Geographie, p. 288. This
method is now frequently employed in France. Details as to the processes
will be found in Mangon Pratique du Drainage, pp. 78 et seqq. Draining by
driving down stakes mentioned in a note in the chapter on the Woods, ante,
is a process of the same nature.
In the United States, large tracts of marshy ground, and even shallow
lakes of considerable extent, have been sufficiently drained not only for
pasturage but for cultivation, without resort to any special measures for
effecting that end. The ordinary processes of rural improvement in the
vicinity, such as felling woods upon and around such grounds, and the
construction of roads, the side ditches of which act as drains, over or near
them, aided now and then by the removal of a fallen tree or other accidental
obstruction in the beds of small streams which flow from them, often
Page 551
suffice to reclaim miles square of unproductive swamp and water. See notes
on p. 20, and on cedar swamps, p. 208, ante.] So at Washington, in the
western part of the city, which lies high above the rivers Potomac and Rock
Creek, many houses are provided with dry wells for draining their cellars
and foundations. These extend through hard, tenacious earth to the depth of
thirty or forty feet, when they strike a stratum of gravel, through which the
water readily passes off. This practice has been extensively employed at
Paris, not merely for carrying off ordinary surface-water, but for the
discharge of offensive and deleterious fluids from chemical and
manufacturing establishments. A well of this sort received, in the winter of
1832-'33, twenty thousand gallons per day of the foul water from a starch
factory, and the same process was largely used in other factories. The
apprehension of injury to common and artesian wells and springs led to an
investigation on this subject by Girard and Parent Duchatelet, in the latter
year. The report of these gentlemen, published in the Annales des Ponts et
Chaussees for 1833, second half-year, is full of curious and instructive facts
respecting the position and distribution of the subterranean waters under
and near Paris; but it must suffice to say that the report came to the
conclusion that, in consequence of the absolute immobility of these waters,
and the relatively small quantity of noxious fluid to be conveyed to them,
there was no danger of the diffusion of such fluid if discharged into them.
This result will not surprise those who know that, in another work,
Duchatelet maintains analogous opinions as to the effect of the discharge of
the city sewers into the Seine or the waters of that river. The quantity of
matter delivered by them he holds to be so nearly infinitesimal, as
compared with the volume of water of the river, that it cannot possibly
affect it to a sensible degree, and therefore cannot render the Seine water
unfit for drinking. [Foonote: Coste found, in his experiments on
pisciculture, that the fermentation, which takes place in the water of the
Seine in consequence of the discharge of the drains into the river, destroyed
on p. 20, and on cedar swamps, p. 208, ante.] So at Washington, in the
western part of the city, which lies high above the rivers Potomac and Rock
Creek, many houses are provided with dry wells for draining their cellars
and foundations. These extend through hard, tenacious earth to the depth of
thirty or forty feet, when they strike a stratum of gravel, through which the
water readily passes off. This practice has been extensively employed at
Paris, not merely for carrying off ordinary surface-water, but for the
discharge of offensive and deleterious fluids from chemical and
manufacturing establishments. A well of this sort received, in the winter of
1832-'33, twenty thousand gallons per day of the foul water from a starch
factory, and the same process was largely used in other factories. The
apprehension of injury to common and artesian wells and springs led to an
investigation on this subject by Girard and Parent Duchatelet, in the latter
year. The report of these gentlemen, published in the Annales des Ponts et
Chaussees for 1833, second half-year, is full of curious and instructive facts
respecting the position and distribution of the subterranean waters under
and near Paris; but it must suffice to say that the report came to the
conclusion that, in consequence of the absolute immobility of these waters,
and the relatively small quantity of noxious fluid to be conveyed to them,
there was no danger of the diffusion of such fluid if discharged into them.
This result will not surprise those who know that, in another work,
Duchatelet maintains analogous opinions as to the effect of the discharge of
the city sewers into the Seine or the waters of that river. The quantity of
matter delivered by them he holds to be so nearly infinitesimal, as
compared with the volume of water of the river, that it cannot possibly
affect it to a sensible degree, and therefore cannot render the Seine water
unfit for drinking. [Foonote: Coste found, in his experiments on
pisciculture, that the fermentation, which takes place in the water of the
Seine in consequence of the discharge of the drains into the river, destroyed
Page 552
a large proportion of the eggs of fish in his breeding basins. Analysis of
Seine water by Boussingault in 1855 detected a considerable quantity of
ammonia.]
Meteorological Effects of Draining.
The draining of lakes diminishes the water-surface of the soil, and
consequently, in many cases, the evaporation from it, as well as the
refrigeration which attends all evaporation. [Footnote: The relative
evaporating action of earth and water is a very complicated problem, and
the results of observation on the subject are conflicting. Schubler found that
at Geneva the evaporation from bare loose earth, in the months of
December, January, and February, was from two and a half to nearly six
times as great as from a like surface of water in the other months. The
evaporation from water was from about once and a half to six times as great
as from earth. Taking the whole year together, the evaporation from the two
surfaces was 199 lines from earth and 536 lines from water. Experiments by
Van der Steer, at the Helder, in the years 1861 and 1862, showed, for the
former year, an evaporation of 602.9 millimetres from water, 1399.6
millimetres from ground covered with clover and other grasses; in 1862, the
evaporation from water was 584.5 millimetres, from grassground, 875.5. —
Wilhelm, Der Boden und das Wasser, p. 57; Krecke, Het Klimaat van
Nederland, ii., p. 111.
On the other hand, the evaporation from the Nile in Egypt and Nubia is
stated to be three times as great as that from an equal surface of the soil
which borders it.—Lombardini, Saggio Idrologico sul Nilo, Milano, 1864,
and Appendix. The relative thermometrical conditions of land and water in
the same vicinity are constantly varying, and the hygrometrical state of both
is equally unstable. Consequently there is no general formula to express the
proportionate evaporation from fluid and solid geographical surfaces.] On
Seine water by Boussingault in 1855 detected a considerable quantity of
ammonia.]
Meteorological Effects of Draining.
The draining of lakes diminishes the water-surface of the soil, and
consequently, in many cases, the evaporation from it, as well as the
refrigeration which attends all evaporation. [Footnote: The relative
evaporating action of earth and water is a very complicated problem, and
the results of observation on the subject are conflicting. Schubler found that
at Geneva the evaporation from bare loose earth, in the months of
December, January, and February, was from two and a half to nearly six
times as great as from a like surface of water in the other months. The
evaporation from water was from about once and a half to six times as great
as from earth. Taking the whole year together, the evaporation from the two
surfaces was 199 lines from earth and 536 lines from water. Experiments by
Van der Steer, at the Helder, in the years 1861 and 1862, showed, for the
former year, an evaporation of 602.9 millimetres from water, 1399.6
millimetres from ground covered with clover and other grasses; in 1862, the
evaporation from water was 584.5 millimetres, from grassground, 875.5. —
Wilhelm, Der Boden und das Wasser, p. 57; Krecke, Het Klimaat van
Nederland, ii., p. 111.
On the other hand, the evaporation from the Nile in Egypt and Nubia is
stated to be three times as great as that from an equal surface of the soil
which borders it.—Lombardini, Saggio Idrologico sul Nilo, Milano, 1864,
and Appendix. The relative thermometrical conditions of land and water in
the same vicinity are constantly varying, and the hygrometrical state of both
is equally unstable. Consequently there is no general formula to express the
proportionate evaporation from fluid and solid geographical surfaces.] On
Page 553
the other hand, if the volume of water abstracted is great, its removal
deprives its basin of an equalizing and moderating influence; for large
bodies of water take very slowly the temperature of the air in contact with
their surface, and are almost constantly either sending off heat into the
atmosphere or absorbing heat from it. Besides, as we have seen, lakes in
elevated positions discharge more or less water by infiltration, and
contribute it by the same process to other lakes, to springs, and to rivulets,
at lower levels. Hence the draining of lakes, on a considerable scale, must
modify both the humidity and the temperature of the atmosphere of the
neighboring regions, and the permanent supply of ground-water for the
lands lying below them.
Meteorological Action of Marshes.
The shallow water of marshes, indeed, performs this latter function, but,
under ordinary circumstances, marshes exercise in but a very small degree
the compensating meteorological action which I have ascribed to large
expansions of deeper water. The direct rays of the sun and the warmth of
the atmosphere penetrate to the soil beneath, and raise the temperature of
the water which covers it; and there is usually a much greater evaporation
from marshes than from lakes in the same region during the warmer half of
the year. This evaporation implies refrigeration, and consequently the
diminution of evaporation by the drainage of swamps tends to prevent the
lowering of the atmospheric temperature, and to lessen the frequency and
severity of frosts. Accordingly it is a fact of experience that, other things
being equal, dry soils, and the air in contact with them, are perceptibly
warmer during the season of vegetation, when evaporation is most rapid,
than moist lands and the atmospheric stratum resting upon them.
Instrumental observation on this special point has not yet been undertaken
on a large scale, but still we have thermometric data sufficient to warrant
deprives its basin of an equalizing and moderating influence; for large
bodies of water take very slowly the temperature of the air in contact with
their surface, and are almost constantly either sending off heat into the
atmosphere or absorbing heat from it. Besides, as we have seen, lakes in
elevated positions discharge more or less water by infiltration, and
contribute it by the same process to other lakes, to springs, and to rivulets,
at lower levels. Hence the draining of lakes, on a considerable scale, must
modify both the humidity and the temperature of the atmosphere of the
neighboring regions, and the permanent supply of ground-water for the
lands lying below them.
Meteorological Action of Marshes.
The shallow water of marshes, indeed, performs this latter function, but,
under ordinary circumstances, marshes exercise in but a very small degree
the compensating meteorological action which I have ascribed to large
expansions of deeper water. The direct rays of the sun and the warmth of
the atmosphere penetrate to the soil beneath, and raise the temperature of
the water which covers it; and there is usually a much greater evaporation
from marshes than from lakes in the same region during the warmer half of
the year. This evaporation implies refrigeration, and consequently the
diminution of evaporation by the drainage of swamps tends to prevent the
lowering of the atmospheric temperature, and to lessen the frequency and
severity of frosts. Accordingly it is a fact of experience that, other things
being equal, dry soils, and the air in contact with them, are perceptibly
warmer during the season of vegetation, when evaporation is most rapid,
than moist lands and the atmospheric stratum resting upon them.
Instrumental observation on this special point has not yet been undertaken
on a large scale, but still we have thermometric data sufficient to warrant
Page 554
the general conclusion, and the influence of drainage in diminishing the
frequency of frost appears to be even better established than a direct
increase of atmospheric temperature. The steep and dry uplands of the
Green Mountain range in New England often escape frosts when the Indian-
corn harvest on moister grounds, five hundred or even a thousand feet
lower, is destroyed or greatly injured by them. The neighborhood of a
marsh is sure to be exposed to late spring and early autumnal frosts, but
they cease to be feared after it is drained, and this is particularly observable
in very cold climates, as, for example, in Lapland. [Footnote: "The simplest
backwoodsman knows by experiences that all cultivation is impossible in
the neighborhood of bogs and marshes. Why is a crop near the borders of a
marsh out off by frost, while a field upon a hillock, a few stone's throws
from it, is spared "—Lars Levi Laestadius, Om Uppoldingar Lappmarrken,
pp. 69, 74.]
In England, under-drains are not generally laid below the reach of daily
variations of temperature, or below a point from which moisture, if not
carried off by the drains, might be brought to the surface by capillary
attraction, and evaporated by the heat of the sun. They, therefore, like
surface-drains, withdraw from local solar action much moisture which
would otherwise be vaporized by it, and, at the same time, by drying the
soil above them, they increase its effective hygroscopicity, and it
consequently absorbs from the atmosphere a greater quantity of water than
it did when, for want of under-drainage, the subsoil was always humid, if
not saturated. [Footnote: Mangon thinks that the diminution of evaporation
by agricultural drainage corresponds, in certain circumstances, to five per
cent. of the heat received from the sun by the same surface in a year. He
cites observations by Parkes, showing a difference in temperature of 5.5
degrees (centigrade ) in favor of drained, as compared with undrained,
ground in the same vicinity.—Instructions pratiques sur le Drainage, pp.
227, 228.
frequency of frost appears to be even better established than a direct
increase of atmospheric temperature. The steep and dry uplands of the
Green Mountain range in New England often escape frosts when the Indian-
corn harvest on moister grounds, five hundred or even a thousand feet
lower, is destroyed or greatly injured by them. The neighborhood of a
marsh is sure to be exposed to late spring and early autumnal frosts, but
they cease to be feared after it is drained, and this is particularly observable
in very cold climates, as, for example, in Lapland. [Footnote: "The simplest
backwoodsman knows by experiences that all cultivation is impossible in
the neighborhood of bogs and marshes. Why is a crop near the borders of a
marsh out off by frost, while a field upon a hillock, a few stone's throws
from it, is spared "—Lars Levi Laestadius, Om Uppoldingar Lappmarrken,
pp. 69, 74.]
In England, under-drains are not generally laid below the reach of daily
variations of temperature, or below a point from which moisture, if not
carried off by the drains, might be brought to the surface by capillary
attraction, and evaporated by the heat of the sun. They, therefore, like
surface-drains, withdraw from local solar action much moisture which
would otherwise be vaporized by it, and, at the same time, by drying the
soil above them, they increase its effective hygroscopicity, and it
consequently absorbs from the atmosphere a greater quantity of water than
it did when, for want of under-drainage, the subsoil was always humid, if
not saturated. [Footnote: Mangon thinks that the diminution of evaporation
by agricultural drainage corresponds, in certain circumstances, to five per
cent. of the heat received from the sun by the same surface in a year. He
cites observations by Parkes, showing a difference in temperature of 5.5
degrees (centigrade ) in favor of drained, as compared with undrained,
ground in the same vicinity.—Instructions pratiques sur le Drainage, pp.
227, 228.
Page 555
The diminution of evaporation is not the only mode in which under-
draining affects the temperature. The increased effective hygroscopicity of
the soil increases its absorbent action, and the condensation of atmospheric
vapor thus produced is attended with the manifestation of heat.] Under-
drains, then, contribute to the dryness as well as to the warmth of the
atmosphere, and, as dry ground is more readily heated by the rays of the sun
than wet, they tend also to raise the mean, and especially the summer,
temperature of the soil.
Effects of Draining Lake of Haarlem.
The meteorological influence of the draining of lakes and of humid soils
has not, so far as I know, received much attention from experimental
physicists; but we are not altogether without direct proof in support of
theoretical and a priori conclusions. Thermometrical observations have
been regularly made at Zwanenburg, near the northern extremity of the
Lake of Haarlem, for more than a century; and since 1845 a similiar registry
has been kept at the Helder, forty or fifty miles more to the north. In
comparing these two series of observations, it is found that towards the end
of 1852, when the draining of the lake was finished, and the following
summer had completely dried the newly exposed soil—and, of course,
greatly diminished the water-surface—a change took place in the relative
temperature of those two stations. Taking the mean of each successive
period of five days, from 1845 to 1852, both inclusive, the temperature of
Zwanenburg was thirty-three hundredths of a degree centigrade LOWER
than at the Helder. From the end of 1852 the thermometer at Zwanenburg
has stood, from the 11th of April to the 20th of September, twenty-two
hundredths of a degree HIGHER than that at Helder; but from the 14th of
October to the 17th of March, it has marked one-tenth of a degree LOWER
draining affects the temperature. The increased effective hygroscopicity of
the soil increases its absorbent action, and the condensation of atmospheric
vapor thus produced is attended with the manifestation of heat.] Under-
drains, then, contribute to the dryness as well as to the warmth of the
atmosphere, and, as dry ground is more readily heated by the rays of the sun
than wet, they tend also to raise the mean, and especially the summer,
temperature of the soil.
Effects of Draining Lake of Haarlem.
The meteorological influence of the draining of lakes and of humid soils
has not, so far as I know, received much attention from experimental
physicists; but we are not altogether without direct proof in support of
theoretical and a priori conclusions. Thermometrical observations have
been regularly made at Zwanenburg, near the northern extremity of the
Lake of Haarlem, for more than a century; and since 1845 a similiar registry
has been kept at the Helder, forty or fifty miles more to the north. In
comparing these two series of observations, it is found that towards the end
of 1852, when the draining of the lake was finished, and the following
summer had completely dried the newly exposed soil—and, of course,
greatly diminished the water-surface—a change took place in the relative
temperature of those two stations. Taking the mean of each successive
period of five days, from 1845 to 1852, both inclusive, the temperature of
Zwanenburg was thirty-three hundredths of a degree centigrade LOWER
than at the Helder. From the end of 1852 the thermometer at Zwanenburg
has stood, from the 11th of April to the 20th of September, twenty-two
hundredths of a degree HIGHER than that at Helder; but from the 14th of
October to the 17th of March, it has marked one-tenth of a degree LOWER
Page 556
than its mean between the same dates before 1853. [Footnote: Krecke, Het
Klimaat van Nederland, ii., p. 64.]
There is no reason to doubt that these differences are due to the draining
of the lake. In summer, solar irradiation has acted more powerfully on the
now exposed earth and of course on the air in contact with it; and there is
no longer a large expanse of water still retaining and of course imparting
something of the winter temperature; in winter, the earth has lost more heat
by radiation than when covered by water and the influence of the lake, as a
reservoir of warmth accumulated in summer and gradually given out in
winter, was of course lost by its drainage. Doubtless the quantity of
moisture contained in the atmosphere has been modified by the same cause,
but it does not appear that observations have been made upon this point.
Facts lately observed by Glaisher tend to prove an elevation of not far from
two degrees in the mean temperature of England during the course of the
last hundred years. For reasons which I have explained elsewhere, the early
observations upon which these conclusions are founded do not deserve
entire confidence; but admitting the fact of the alleged elevation, its most
probable explanation would be found in the more thorough draining of the
soil by superficial and by subterranean conduits.
So far as respects the immediate improvement of soil and climate, and
the increased abundance of the harvests, the English system of surface and
subsoil drainage has fully justified the eulogiums of its advocates; but its
extensive adoption appears to have been attended with some altogether
unforeseen and undesirable consequences, very analogous to those which I
have described as resulting from the clearing of the forests. The under-
drains carry off very rapidly the water imbibed by the soil from
precipitation, and through infiltration from neighboring springs or other
sources of supply. Consequently, in wet seasons, or after heavy rains, a river
bordered by artificially drained lands receives in a few hours, from
Klimaat van Nederland, ii., p. 64.]
There is no reason to doubt that these differences are due to the draining
of the lake. In summer, solar irradiation has acted more powerfully on the
now exposed earth and of course on the air in contact with it; and there is
no longer a large expanse of water still retaining and of course imparting
something of the winter temperature; in winter, the earth has lost more heat
by radiation than when covered by water and the influence of the lake, as a
reservoir of warmth accumulated in summer and gradually given out in
winter, was of course lost by its drainage. Doubtless the quantity of
moisture contained in the atmosphere has been modified by the same cause,
but it does not appear that observations have been made upon this point.
Facts lately observed by Glaisher tend to prove an elevation of not far from
two degrees in the mean temperature of England during the course of the
last hundred years. For reasons which I have explained elsewhere, the early
observations upon which these conclusions are founded do not deserve
entire confidence; but admitting the fact of the alleged elevation, its most
probable explanation would be found in the more thorough draining of the
soil by superficial and by subterranean conduits.
So far as respects the immediate improvement of soil and climate, and
the increased abundance of the harvests, the English system of surface and
subsoil drainage has fully justified the eulogiums of its advocates; but its
extensive adoption appears to have been attended with some altogether
unforeseen and undesirable consequences, very analogous to those which I
have described as resulting from the clearing of the forests. The under-
drains carry off very rapidly the water imbibed by the soil from
precipitation, and through infiltration from neighboring springs or other
sources of supply. Consequently, in wet seasons, or after heavy rains, a river
bordered by artificially drained lands receives in a few hours, from
Page 557
superficial and from subterranean conduits, an accession of water which, in
the natural state of the earth, would have reached it only by small
instalments after percolating through hidden paths for weeks or even
months, and would have furnished perennial and comparatively regular
contributions, instead of swelling deluges, to its channel. Thus, when
human impatience rashly substitutes swiftly acting artificial contrivances
for the slow methods by which nature drains the surface and superficial
strata of a river-basin, the original equilibrium is disturbed, the waters of the
heavens are no longer stored up in the earth to be gradually given out again,
but are hurried out of man's domain with wasteful haste; and while the
inundations of the river are sudden and disastrous, its current, when the
drains have run dry, is reduced to a rivulet, it ceases to supply the power to
drive the machinery for which it was once amply sufficient, and scarcely
even waters the herds that pasture upon its margin.
The water of subterranean currents and reservoirs, as well as that of
springs and common wells, is doubtless principally furnished by infiltration,
and hence its quantity must vary with every change of natural surface which
tends to accelerate or to retard the drainage of the surface-soil. The drainage
of marshes, therefore, and all other methods of drying the superficial strata,
whether by open ditches or by underground tubes or drains, has the same
effect as clearing off the forest in depriving the subterranean waters of
accessions which they would otherwise receive by infiltration, and in
proportion as the sphere of such operation is extended, their influence will
make itself felt in the diminished supply of water in springs and wells.
[Footnote: Babinet condemns the general draining of marshes. "Draining,"
says he, "has been much in vogue for some years, and it has been a special
object to dry and fertilize marshy grounds. I believe that excessive dryness
is thus produced, and that other soils in the neighborhood are sterilized in
proportion."—Etudes et Lectures, iv., p. 118.
the natural state of the earth, would have reached it only by small
instalments after percolating through hidden paths for weeks or even
months, and would have furnished perennial and comparatively regular
contributions, instead of swelling deluges, to its channel. Thus, when
human impatience rashly substitutes swiftly acting artificial contrivances
for the slow methods by which nature drains the surface and superficial
strata of a river-basin, the original equilibrium is disturbed, the waters of the
heavens are no longer stored up in the earth to be gradually given out again,
but are hurried out of man's domain with wasteful haste; and while the
inundations of the river are sudden and disastrous, its current, when the
drains have run dry, is reduced to a rivulet, it ceases to supply the power to
drive the machinery for which it was once amply sufficient, and scarcely
even waters the herds that pasture upon its margin.
The water of subterranean currents and reservoirs, as well as that of
springs and common wells, is doubtless principally furnished by infiltration,
and hence its quantity must vary with every change of natural surface which
tends to accelerate or to retard the drainage of the surface-soil. The drainage
of marshes, therefore, and all other methods of drying the superficial strata,
whether by open ditches or by underground tubes or drains, has the same
effect as clearing off the forest in depriving the subterranean waters of
accessions which they would otherwise receive by infiltration, and in
proportion as the sphere of such operation is extended, their influence will
make itself felt in the diminished supply of water in springs and wells.
[Footnote: Babinet condemns the general draining of marshes. "Draining,"
says he, "has been much in vogue for some years, and it has been a special
object to dry and fertilize marshy grounds. I believe that excessive dryness
is thus produced, and that other soils in the neighborhood are sterilized in
proportion."—Etudes et Lectures, iv., p. 118.
Page 558
"The extent of soil artificially dried by drainage is constantly increasing,
and the water received by the surface from precipitation flows off by new
channels, and is in general carried off more rapidly than before. Must not
this fact exercise an influence on the regime of springs whose basin of
supply thus undergoes a more or less complete transformation "—Bernhard
Cotta, Preface to Paramelle, Quellenkunde, p. vii., viii.
The effects of agricultural drainage are perceptible at great depths. It has
been observed in Cornwall that deep mines are more free from water in
well-drained districts than in those where drainage is not generally
practised.—Esquiros, Revue des Deux Mondes, 15 Nov., 1863, p. 430.
See also Asbjornsen, Torv og Torvdrift, p. 31.]
Geographical and Meteorological Effects of Aqueducts, Reservoirs, and
Canals.
Many of the great processes of internal improvement, such as aqueducts
for the supply of great cities, railroad cuts and embankments, and the like,
divert water from its natural channels and affect its distribution and ultimate
discharge. The collecting of the waters of a considerable district into
reservoirs, to be thence carried off by means of aqueducts, as, for example,
in the forest of Belgrade, near Constantinople, deprives the grounds
originally watered by the springs and rivulets of the necessary moisture, and
reduces them to barrenness. [Footnote: See a very interesting paper on the
Water-Supply of Constantinople, by Mr. Homes, of the New York State
Library, in the Albany Argus of June 6, 1872. The system of aqueducts for
the supply of water to that city was commenced by Constantine, and the
great aqueduct, frequently ascribed to Justinian, which is 840 feet long and
112 feet high, is believed to have been constructed during the reign of the
former emperor.] Similar effects must have followed from the construction
and the water received by the surface from precipitation flows off by new
channels, and is in general carried off more rapidly than before. Must not
this fact exercise an influence on the regime of springs whose basin of
supply thus undergoes a more or less complete transformation "—Bernhard
Cotta, Preface to Paramelle, Quellenkunde, p. vii., viii.
The effects of agricultural drainage are perceptible at great depths. It has
been observed in Cornwall that deep mines are more free from water in
well-drained districts than in those where drainage is not generally
practised.—Esquiros, Revue des Deux Mondes, 15 Nov., 1863, p. 430.
See also Asbjornsen, Torv og Torvdrift, p. 31.]
Geographical and Meteorological Effects of Aqueducts, Reservoirs, and
Canals.
Many of the great processes of internal improvement, such as aqueducts
for the supply of great cities, railroad cuts and embankments, and the like,
divert water from its natural channels and affect its distribution and ultimate
discharge. The collecting of the waters of a considerable district into
reservoirs, to be thence carried off by means of aqueducts, as, for example,
in the forest of Belgrade, near Constantinople, deprives the grounds
originally watered by the springs and rivulets of the necessary moisture, and
reduces them to barrenness. [Footnote: See a very interesting paper on the
Water-Supply of Constantinople, by Mr. Homes, of the New York State
Library, in the Albany Argus of June 6, 1872. The system of aqueducts for
the supply of water to that city was commenced by Constantine, and the
great aqueduct, frequently ascribed to Justinian, which is 840 feet long and
112 feet high, is believed to have been constructed during the reign of the
former emperor.] Similar effects must have followed from the construction
Page 559
of the numerous aqueducts which supplied ancient Rome with such a
profuse abundance of water. [Footnote: The unhealthiness of the Roman
Campagna is ascribed by many mediaeval as well as later writers to the
escape of water from the ancient aqueducts, which had fallen out of repair
from neglect, or been broken down by enemies in the sieges of Rome.] On
the other hand, the filtration of water through the banks or walls of an
aqueduct carried upon a high level across low ground, often injures the
adjacent soil, and is prejudicial to the health of the neighboring population;
and it has been observed in Switzerland and elsewhere, that fevers have
been produced by the stagnation of the water in excavations from which
earth had been taken to form embankments for railways.
If we consider only the influence of physical improvements on civilized
life, we shall perhaps ascribe to navigable canals a higher importance, or at
least a more diversified influence, than to aqueducts or to any other works
of man designed to control the waters of the earth, and to affect their
distribution. They bind distant regions together by social ties, through the
agency of the commerce they promote; they facilitate the transportation of
military stores and engines, and of other heavy material connected with the
discharge of the functions of government; they encourage industry by
giving marketable value to raw material and to objects of artificial
elaboration which would otherwise be worthless on account of the cost of
conveyance; they supply from their surplus waters means of irrigation and
of mechanical power; and, in many other ways, they contribute much to
advance the prosperity and civilization of nations. Nor are they wholly
without geographical importance. They sometimes drain lands by
conveying off water which would otherwise stagnate on the surface, and, on
the other hand, like aqueducts, they render the neighboring soil cold and
moist by the percolation of water through their embankments; [Footnote:
Sismondi, speaking of the Tuscan canals, observes: "But inundations are not
the only damage caused by the waters to the plains of Tuscany. Raised, as
profuse abundance of water. [Footnote: The unhealthiness of the Roman
Campagna is ascribed by many mediaeval as well as later writers to the
escape of water from the ancient aqueducts, which had fallen out of repair
from neglect, or been broken down by enemies in the sieges of Rome.] On
the other hand, the filtration of water through the banks or walls of an
aqueduct carried upon a high level across low ground, often injures the
adjacent soil, and is prejudicial to the health of the neighboring population;
and it has been observed in Switzerland and elsewhere, that fevers have
been produced by the stagnation of the water in excavations from which
earth had been taken to form embankments for railways.
If we consider only the influence of physical improvements on civilized
life, we shall perhaps ascribe to navigable canals a higher importance, or at
least a more diversified influence, than to aqueducts or to any other works
of man designed to control the waters of the earth, and to affect their
distribution. They bind distant regions together by social ties, through the
agency of the commerce they promote; they facilitate the transportation of
military stores and engines, and of other heavy material connected with the
discharge of the functions of government; they encourage industry by
giving marketable value to raw material and to objects of artificial
elaboration which would otherwise be worthless on account of the cost of
conveyance; they supply from their surplus waters means of irrigation and
of mechanical power; and, in many other ways, they contribute much to
advance the prosperity and civilization of nations. Nor are they wholly
without geographical importance. They sometimes drain lands by
conveying off water which would otherwise stagnate on the surface, and, on
the other hand, like aqueducts, they render the neighboring soil cold and
moist by the percolation of water through their embankments; [Footnote:
Sismondi, speaking of the Tuscan canals, observes: "But inundations are not
the only damage caused by the waters to the plains of Tuscany. Raised, as
Page 560
the canals are, above the soil, the water percolates through their banks,
penetrates every obstruction, and, in spite of all the efforts of industry,
sterilizes and turns to morasses fields which nature and the richness of the
soil seemed to have designed for the most abundant harvests. In ground thus
pervaded with moisture, or rendered COLD, as the Tuscans express it, by
the filtration of the canal-water, the vines and the mulberries, after having
for a few years yielded fruit of a saltish taste, rot and perish. The wheat
decays in the ground, or dies as soon as it sprouts. Winter crops are given
up, and summer cultivation tried for a time; but the increasing humidity,
and the saline matter communicated to the earth—which affects the taste of
all its products, even to the grasses, which the cattle refuse to touch—at last
compel the husbandman to abandon his fields and leave uncultivated a soil
that no longer repays his labor."—Tableau de l'Agriculture Toscane, pp. 11,
12.] they dam up, check, and divert the course of natural currents, and
deliver them at points opposite to, or distant from, their original outlets;
they often require extensive reservoirs to feed them thus retaining through
the year accumulations of water—which would otherwise run off, or
evaporate in the dry season—and thereby enlarging the evaporable surface
of the country; and we have already seen that they interchange the flora and
the fauna of provinces widely separated by nature. All these modes of
action certainly influence climate and the character of terrestrial surface,
though our means of observation are not yet perfected enough to enable us
to appreciate and measure their effects.
Antiquity of Irrigation.
We know little of the history of the extinct civilizations which preceded
the culture of the classic ages, and no nation has, in modern times,
spontaneously emerged from barbarian and created for itself the arts of
social life. [Footnote: I ought perhaps to except the Mexicans and the
penetrates every obstruction, and, in spite of all the efforts of industry,
sterilizes and turns to morasses fields which nature and the richness of the
soil seemed to have designed for the most abundant harvests. In ground thus
pervaded with moisture, or rendered COLD, as the Tuscans express it, by
the filtration of the canal-water, the vines and the mulberries, after having
for a few years yielded fruit of a saltish taste, rot and perish. The wheat
decays in the ground, or dies as soon as it sprouts. Winter crops are given
up, and summer cultivation tried for a time; but the increasing humidity,
and the saline matter communicated to the earth—which affects the taste of
all its products, even to the grasses, which the cattle refuse to touch—at last
compel the husbandman to abandon his fields and leave uncultivated a soil
that no longer repays his labor."—Tableau de l'Agriculture Toscane, pp. 11,
12.] they dam up, check, and divert the course of natural currents, and
deliver them at points opposite to, or distant from, their original outlets;
they often require extensive reservoirs to feed them thus retaining through
the year accumulations of water—which would otherwise run off, or
evaporate in the dry season—and thereby enlarging the evaporable surface
of the country; and we have already seen that they interchange the flora and
the fauna of provinces widely separated by nature. All these modes of
action certainly influence climate and the character of terrestrial surface,
though our means of observation are not yet perfected enough to enable us
to appreciate and measure their effects.
Antiquity of Irrigation.
We know little of the history of the extinct civilizations which preceded
the culture of the classic ages, and no nation has, in modern times,
spontaneously emerged from barbarian and created for itself the arts of
social life. [Footnote: I ought perhaps to except the Mexicans and the
Page 561
Peruvians, whose arts and institutions are not yet shown to be historically
connected with those of any more ancient people. The lamentable
destruction of so many memorials of these tribes, by the ignorance and
bigotry of the so-called Christian barbarians who conquered them, has left
us much in the dark as to many points of their civilization; but they seem to
have reached that stage where continued progress in knowledge and in
power over nature is secure, and a few more centuries of independence
might have brought them to originate for themselves most of the great
inventions which the last four centuries have bestowed upon man.] The
improvements of the savage races whose history we can distinctly trace are
borrowed and imitative, and our theories as to the origin and natural
development of industrial art are conjectural. Of course, the relative
antiquity of particular branches of human industry depends much upon the
natural character of soil, climate, and spontaneous vegetable and animal life
in different countries; and while the geographical influence of man would,
under given circumstances, be exerted in one direction, it would, under
different conditions, act in an opposite or a diverging line. I have given
some reasons for thinking that in the climates to which our attention has
been chiefly directed, man's first interference with the natural arrangement
and disposal of the waters was in the way of drainage of surface. But if we
are to judge from existing remains alone, we should probably conclude that
irrigation is older than drainage; for, in the regions regarded by general
tradition as the cradle of the human race, we find traces of canals evidently
constructed for the former purpose at a period long preceding the ages of
which we have any written memorials. There are, in ancient Armenia,
extensive districts which were already abandoned to desolation at the
earliest historical epoch, but which, in a yet remoter antiquity, had been
irrigated by a complicated and highly artificial system of canals, the lines of
which can still be followed; and there are, in all the highlands where the
sources of the Euphrates rise, in Persia, in Egypt, in India, and in China,
connected with those of any more ancient people. The lamentable
destruction of so many memorials of these tribes, by the ignorance and
bigotry of the so-called Christian barbarians who conquered them, has left
us much in the dark as to many points of their civilization; but they seem to
have reached that stage where continued progress in knowledge and in
power over nature is secure, and a few more centuries of independence
might have brought them to originate for themselves most of the great
inventions which the last four centuries have bestowed upon man.] The
improvements of the savage races whose history we can distinctly trace are
borrowed and imitative, and our theories as to the origin and natural
development of industrial art are conjectural. Of course, the relative
antiquity of particular branches of human industry depends much upon the
natural character of soil, climate, and spontaneous vegetable and animal life
in different countries; and while the geographical influence of man would,
under given circumstances, be exerted in one direction, it would, under
different conditions, act in an opposite or a diverging line. I have given
some reasons for thinking that in the climates to which our attention has
been chiefly directed, man's first interference with the natural arrangement
and disposal of the waters was in the way of drainage of surface. But if we
are to judge from existing remains alone, we should probably conclude that
irrigation is older than drainage; for, in the regions regarded by general
tradition as the cradle of the human race, we find traces of canals evidently
constructed for the former purpose at a period long preceding the ages of
which we have any written memorials. There are, in ancient Armenia,
extensive districts which were already abandoned to desolation at the
earliest historical epoch, but which, in a yet remoter antiquity, had been
irrigated by a complicated and highly artificial system of canals, the lines of
which can still be followed; and there are, in all the highlands where the
sources of the Euphrates rise, in Persia, in Egypt, in India, and in China,
Page 562
works of this sort which must have been in existence before man had begun
to record his own annals.
In warm countries, such as most of those just mentioned, the effects I
have described as usually resulting from the clearing of the forests would
very soon follow. In such climates, the rains are inclined to be periodical;
they are also violent, and for these reasons the soil would be parched in
summer and liable to wash in winter. In these countries, therefore, the
necessity for irrigation must soon have been felt, and its introduction into
mountainous regions like Armenia must have been immediately followed
by a system of terracing, or at least scarping the hillsides. Pasture and
meadow, indeed, may be irrigated even when the surface is both steep and
irregular, as may be observed abundantly on the Swiss as well as on the
Piedmontese slope of the Alps; but in dry climates, ploughland and gardens
on hilly grounds require terracing, both for supporting the soil and for
administering water by irrigation, and it should be remembered that
terracing, of itself, even without special arrangements for controlling the
distribution of water, prevents or at least checks the flow of rain-water, and
gives it time to sink into the ground instead of running off over the surface.
The summers in Egypt, in Syria, and in Asia Minor and even Rumelia,
are almost rainless. In such climates, the neccssity of irrigation is obvious,
and the loss of the ancient means of furnishing it helps to explain the
diminished fertility of most of the countries in question. [Footnote: In
Egypt, evaporation and absorption by the earth are so rapid, that all annual
crops require irrigation during the whole period of their growth. As fast as
the water retires by the subsidence of the annual inundation, the seed is
sown upon the still moist, uncovered soil, and irrigation begins at once.
Upon the Nile, you hear the creaking of the water-wheels, and sometimes
the movement of steam-pumps, through the whole night, while the poorer
cultivators unceasingly ply the simple shadoof, or bucket-and-sweep,
to record his own annals.
In warm countries, such as most of those just mentioned, the effects I
have described as usually resulting from the clearing of the forests would
very soon follow. In such climates, the rains are inclined to be periodical;
they are also violent, and for these reasons the soil would be parched in
summer and liable to wash in winter. In these countries, therefore, the
necessity for irrigation must soon have been felt, and its introduction into
mountainous regions like Armenia must have been immediately followed
by a system of terracing, or at least scarping the hillsides. Pasture and
meadow, indeed, may be irrigated even when the surface is both steep and
irregular, as may be observed abundantly on the Swiss as well as on the
Piedmontese slope of the Alps; but in dry climates, ploughland and gardens
on hilly grounds require terracing, both for supporting the soil and for
administering water by irrigation, and it should be remembered that
terracing, of itself, even without special arrangements for controlling the
distribution of water, prevents or at least checks the flow of rain-water, and
gives it time to sink into the ground instead of running off over the surface.
The summers in Egypt, in Syria, and in Asia Minor and even Rumelia,
are almost rainless. In such climates, the neccssity of irrigation is obvious,
and the loss of the ancient means of furnishing it helps to explain the
diminished fertility of most of the countries in question. [Footnote: In
Egypt, evaporation and absorption by the earth are so rapid, that all annual
crops require irrigation during the whole period of their growth. As fast as
the water retires by the subsidence of the annual inundation, the seed is
sown upon the still moist, uncovered soil, and irrigation begins at once.
Upon the Nile, you hear the creaking of the water-wheels, and sometimes
the movement of steam-pumps, through the whole night, while the poorer
cultivators unceasingly ply the simple shadoof, or bucket-and-sweep,
Page 563
laboriously raising the water from trough to trough by as many as six or
seven stages when the river is low. The bucket is of flexible leather, with a
stiff rim, and is emptied into the trough, not by inverting it like a wooden
bucket, but by putting the hand beneath and pushing the bottom up till the
water all runs out over the brim, or, in other words, by turning the vessel
inside out.
The quantity of water thus withdrawn from the Nile is enormous. Most of
this is evaporated directly from the surface or the superficial strata, but
some moisture percolates down and oozes through the banks into the river
again, while a larger quantity sinks till it joins the slow current of
infiltration by which the Nile water pervades the earth of the valley to the
distance, at some points, of not less than fifty miles.] The surface of
Palestine, for example, is composed, in a great measure, of rounded
limestone hills, once, no doubt, covered with forests. These were partially
removed before the Jewish conquest. [Footnote: "Forests," "woods," and
"groves," are frequently mentioned in the Old Testament as existing at
particular places, and they are often referred to by way of illustration, as
familiar objects. "Wood" is twice spoken of as a material in the New
Testament, but otherwise—at least according to Cruden—not one of the
above words occurs in that volume. In like manner, while the box, the
cedar, the fir, the oak, the pine, "beams," and "timber," are very frequently
mentioned in the Old Testament, not one of these words is found in the
New, EXCEPT the case of the "beam in the eye," in the parable in Matthew
and Luke.
This interesting fact, were other evidence wanting, would go far to prove
that a great change had taken place in this respect between the periods when
the Old Testament and the New were respectively composed; for the
scriptural writers, and the speakers introduced into their narratives, are
remarkable for their frequent allusions to the natural objects and the social
seven stages when the river is low. The bucket is of flexible leather, with a
stiff rim, and is emptied into the trough, not by inverting it like a wooden
bucket, but by putting the hand beneath and pushing the bottom up till the
water all runs out over the brim, or, in other words, by turning the vessel
inside out.
The quantity of water thus withdrawn from the Nile is enormous. Most of
this is evaporated directly from the surface or the superficial strata, but
some moisture percolates down and oozes through the banks into the river
again, while a larger quantity sinks till it joins the slow current of
infiltration by which the Nile water pervades the earth of the valley to the
distance, at some points, of not less than fifty miles.] The surface of
Palestine, for example, is composed, in a great measure, of rounded
limestone hills, once, no doubt, covered with forests. These were partially
removed before the Jewish conquest. [Footnote: "Forests," "woods," and
"groves," are frequently mentioned in the Old Testament as existing at
particular places, and they are often referred to by way of illustration, as
familiar objects. "Wood" is twice spoken of as a material in the New
Testament, but otherwise—at least according to Cruden—not one of the
above words occurs in that volume. In like manner, while the box, the
cedar, the fir, the oak, the pine, "beams," and "timber," are very frequently
mentioned in the Old Testament, not one of these words is found in the
New, EXCEPT the case of the "beam in the eye," in the parable in Matthew
and Luke.
This interesting fact, were other evidence wanting, would go far to prove
that a great change had taken place in this respect between the periods when
the Old Testament and the New were respectively composed; for the
scriptural writers, and the speakers introduced into their narratives, are
remarkable for their frequent allusions to the natural objects and the social
Page 564
and industrial habits which characterized their ages and their country.]
When the soil began to suffer from drought, reservoirs to retain the waters
of winter were hewn in the rock near the tops of the hills, and the declivities
were terraced. So long as the cisterns were in good order, and the terraces
kept up, the fertility of Palestine was unsurpassed, but when misgovernment
and foreign and intestine war occasioned the neglect or destruction of these
works—traces of which still meet the traveller's eye at every step,—when
the reservoirs were broken and the terrace walls had fallen down, there was
no longer water for irrigation in summer, the rains of winter soon washed
away most of the thin layer of earth upon the rocks, and Palestine was
reduced almost to the condition of a desert.
The course of events has been the same in Idumaea. The observing
traveller discovers everywhere about Petra, particularly if he enters the city
by the route of Wadi Ksheibeh, very extensive traces of ancient cultivation,
and upon the neighboring ridges are the ruins of numerous cisterns
evidently constructed to furnish a supply of water for irrigation. [Footnote:
One of these on Mount Hor, two stories deep, is in such good preservation,
although probably not repaired for many centuries, that I found ten feet of
water in it in June, 1851.] In primitive ages, the precipitation of winter in
these hilly countries was, in great part, retained for a time in the superficial
soil, first by the vegetable mould of the forests, and then by the artificial
arrangements I have described. The water imbibed by the earth was partly
taken up by direct evaporation, partly absorbed by vegetation, and partly
carried down by infiltration to subjacent strata which gave it out in springs
at lower levels, and thus a fertility of soil and a condition of the atmosphere
were maintained sufficient to admit of the dense population that once
inhabited those now arid wastes. At present, the rain-water runs
immediately off from the surface and is carried down to the sea, or is drunk
up by the sands of the wadis, and the hillsides which once teemed with
When the soil began to suffer from drought, reservoirs to retain the waters
of winter were hewn in the rock near the tops of the hills, and the declivities
were terraced. So long as the cisterns were in good order, and the terraces
kept up, the fertility of Palestine was unsurpassed, but when misgovernment
and foreign and intestine war occasioned the neglect or destruction of these
works—traces of which still meet the traveller's eye at every step,—when
the reservoirs were broken and the terrace walls had fallen down, there was
no longer water for irrigation in summer, the rains of winter soon washed
away most of the thin layer of earth upon the rocks, and Palestine was
reduced almost to the condition of a desert.
The course of events has been the same in Idumaea. The observing
traveller discovers everywhere about Petra, particularly if he enters the city
by the route of Wadi Ksheibeh, very extensive traces of ancient cultivation,
and upon the neighboring ridges are the ruins of numerous cisterns
evidently constructed to furnish a supply of water for irrigation. [Footnote:
One of these on Mount Hor, two stories deep, is in such good preservation,
although probably not repaired for many centuries, that I found ten feet of
water in it in June, 1851.] In primitive ages, the precipitation of winter in
these hilly countries was, in great part, retained for a time in the superficial
soil, first by the vegetable mould of the forests, and then by the artificial
arrangements I have described. The water imbibed by the earth was partly
taken up by direct evaporation, partly absorbed by vegetation, and partly
carried down by infiltration to subjacent strata which gave it out in springs
at lower levels, and thus a fertility of soil and a condition of the atmosphere
were maintained sufficient to admit of the dense population that once
inhabited those now arid wastes. At present, the rain-water runs
immediately off from the surface and is carried down to the sea, or is drunk
up by the sands of the wadis, and the hillsides which once teemed with
Page 565
plenty are bare of vegetation, and seared by the scorching winds of the
desert.
In fact, climatic conditions render irrigation a necessity in all the oriental
countries which have any importance in ancient or in modern history, and
there can be no doubt that this diffusion of water over large surfaces has a
certain reaction on climate. Some idea of the extent of artificially watered
soil in India may be formed from the fact that in fourteen districts of the
Presidency of Madras, not less than 43,000 reservoirs, constructed by the
ancient native rulers for the purpose of irrigation, are now in use, and that
there are in those districts at least 10,000 more which are in ruins and
useless. These reservoirs are generally formed by damming the outlets of
natural valleys; and the dams average half a mile in length, though some of
them are thirty miles long and form ponds covering from 37,000 to 50,000
acres. The areas of these reservoirs alone considerably increase the water-
surface, and each one of them irrigates an extent of cultivated ground much
larger than itself. Hence there is a great augmentation of humid surface
from those constructions. [Footnote: The present government of India
obtains the same result more economically and advantageously by
constructing in many provinces of that vast empire canals of great length
and capacity, which not only furnish a greater supply of water than the old
reservoirs, but so distribute it as to irrigate a larger area than could be
watered by any system of artificial basins. The excavacations for the
Ganges Canal were nearly equal to those for the Suez Canal, falling little
short of 100,000 cubic yards, without counting feeders and accessory lines
amounting to a length of 3,000 miles. This canal, according to a recent
article in the London Times, waters a tract of land 320 miles long by 50
broad. The Jumna Canal, 130 miles long, with 608 miles of distributing
branches, waters a territory 120 miles long with a breadth of 15 miles.
desert.
In fact, climatic conditions render irrigation a necessity in all the oriental
countries which have any importance in ancient or in modern history, and
there can be no doubt that this diffusion of water over large surfaces has a
certain reaction on climate. Some idea of the extent of artificially watered
soil in India may be formed from the fact that in fourteen districts of the
Presidency of Madras, not less than 43,000 reservoirs, constructed by the
ancient native rulers for the purpose of irrigation, are now in use, and that
there are in those districts at least 10,000 more which are in ruins and
useless. These reservoirs are generally formed by damming the outlets of
natural valleys; and the dams average half a mile in length, though some of
them are thirty miles long and form ponds covering from 37,000 to 50,000
acres. The areas of these reservoirs alone considerably increase the water-
surface, and each one of them irrigates an extent of cultivated ground much
larger than itself. Hence there is a great augmentation of humid surface
from those constructions. [Footnote: The present government of India
obtains the same result more economically and advantageously by
constructing in many provinces of that vast empire canals of great length
and capacity, which not only furnish a greater supply of water than the old
reservoirs, but so distribute it as to irrigate a larger area than could be
watered by any system of artificial basins. The excavacations for the
Ganges Canal were nearly equal to those for the Suez Canal, falling little
short of 100,000 cubic yards, without counting feeders and accessory lines
amounting to a length of 3,000 miles. This canal, according to a recent
article in the London Times, waters a tract of land 320 miles long by 50
broad. The Jumna Canal, 130 miles long, with 608 miles of distributing
branches, waters a territory 120 miles long with a breadth of 15 miles.
Page 566
Other statements estimate the amount of land actually under irrigation in
British India at 6,000,000 acres, and add that canals now in construction
will water as much more. The Indian irrigation canals are generally
navigable, some of them by boats of large tonnage, and the canals return a
net revenue of from five to twenty per cent. on their cost.]
The cultivable area of Egypt, or the space between desert and desert
where cultivation would be possible, is now estimated at ten thousand
square statute miles. [Footnote: The area which the waters of the Nile, left
to themselves, would now cover is greater than it would have been in
ancient times, because the bed of the river has been elevated, and
consequently the lateral spread of the inundation increased. See Smith's
Dictionary of Geography, article "Aegyptus". But the industry of the
Egyptians in the days of the Pharaohs and the Ptolemies carried the Nile-
water to large provinces, which have now been long abandoned and have
relapsed into the condition of desert. "Anciently," observes the writer of the
article "Egypt" in Smith's Dictionary of the Bible, "2,735 square miles more
[about 3,700 square statute miles] may have been cultivated. In the best
days of Egypt, probably all the land was cultivated that could be made
available for agricultural purposes, and hence we may estimate the ancient
arable area of that country at not less than 11,000 square statute miles, or
fully double its present extent."
According to an article in the Bollettino della Societa Geografica Italiana,
vol. v., pt. iii., p. 210, the cultivated soil of Egypt in 1869 amounted to
4,500,000 acres, and the remaining soil capable of cultivation was estimated
at 2,000,000 acres.] Much of the surface, though not out of the reach of
irrigation, lies too high to be economically watered, and irrigation and
cultivation are therefore at present confined to an area of seven thousand
square miles, nearly the whole of which is regularly and constantly watered
when not covered by the inundation, except in the short interval between
British India at 6,000,000 acres, and add that canals now in construction
will water as much more. The Indian irrigation canals are generally
navigable, some of them by boats of large tonnage, and the canals return a
net revenue of from five to twenty per cent. on their cost.]
The cultivable area of Egypt, or the space between desert and desert
where cultivation would be possible, is now estimated at ten thousand
square statute miles. [Footnote: The area which the waters of the Nile, left
to themselves, would now cover is greater than it would have been in
ancient times, because the bed of the river has been elevated, and
consequently the lateral spread of the inundation increased. See Smith's
Dictionary of Geography, article "Aegyptus". But the industry of the
Egyptians in the days of the Pharaohs and the Ptolemies carried the Nile-
water to large provinces, which have now been long abandoned and have
relapsed into the condition of desert. "Anciently," observes the writer of the
article "Egypt" in Smith's Dictionary of the Bible, "2,735 square miles more
[about 3,700 square statute miles] may have been cultivated. In the best
days of Egypt, probably all the land was cultivated that could be made
available for agricultural purposes, and hence we may estimate the ancient
arable area of that country at not less than 11,000 square statute miles, or
fully double its present extent."
According to an article in the Bollettino della Societa Geografica Italiana,
vol. v., pt. iii., p. 210, the cultivated soil of Egypt in 1869 amounted to
4,500,000 acres, and the remaining soil capable of cultivation was estimated
at 2,000,000 acres.] Much of the surface, though not out of the reach of
irrigation, lies too high to be economically watered, and irrigation and
cultivation are therefore at present confined to an area of seven thousand
square miles, nearly the whole of which is regularly and constantly watered
when not covered by the inundation, except in the short interval between
Page 567
the harvest and the rise of the waters. For nearly half of the year, then,
irrigation adds seven thousand square miles to the humid surface of the Nile
valley, or, in other words, more than decuples the area from which an
appreciable quantity of moisture would otherwise be evaporated; for after
the Nile has retired within its banks, its waters by no means cover one-tenth
of the space just mentioned.
The Nile receives not a single tributary in its course below Khartoum;
there is not so much as one living spring in the whole land, [Footnote: The
so-called spring at Heliopolis is only a thread of water infiltrated from the
Nile or the canals.] and, with the exception of a narrow strip of coast, where
the annual precipitation is said to amount to six inches, the fall of rain in the
territory of the Pharaohs is not two inches in the year. The subsoil of the
whole valley is pervaded with moisture by infiltration from the Nile, and
water can everywhere be found at the depth of a few feet. Were irrigation
suspended, and Egypt abandoned, as in that case it must be, to the
operations of nature, there is no doubt that trees, the roots of which
penetrate deeply, would in time establish themselves on the deserted soil,
fill the valley with verdure, and perhaps at last temper the climate, and even
call down abundant rain from the heavens. [Footnote: The date and the
doum palm, the sont and many other acacias, the caroub, the sycamore and
other trees grow in Egypt without irrigation, and would doubtless spread
through the entire valley in a few years.] But the immediate effect of
discontinuing irrigation would be, first, an immense reduction of the
evaporation from the valley in the dry season, and then a greatly augmented
dryness and heat of the atmosphere. Even the almost constant north wind—
the strength of which would be increased in consequence of these changes
—would little reduce the temperature of the narrow cleft between the
burning mountains which hem in the channel of the Nile, so that a single
year would transform the most fertile of soils to the most barren of deserts,
and render uninhabitable a territory that irrigation makes capable of
irrigation adds seven thousand square miles to the humid surface of the Nile
valley, or, in other words, more than decuples the area from which an
appreciable quantity of moisture would otherwise be evaporated; for after
the Nile has retired within its banks, its waters by no means cover one-tenth
of the space just mentioned.
The Nile receives not a single tributary in its course below Khartoum;
there is not so much as one living spring in the whole land, [Footnote: The
so-called spring at Heliopolis is only a thread of water infiltrated from the
Nile or the canals.] and, with the exception of a narrow strip of coast, where
the annual precipitation is said to amount to six inches, the fall of rain in the
territory of the Pharaohs is not two inches in the year. The subsoil of the
whole valley is pervaded with moisture by infiltration from the Nile, and
water can everywhere be found at the depth of a few feet. Were irrigation
suspended, and Egypt abandoned, as in that case it must be, to the
operations of nature, there is no doubt that trees, the roots of which
penetrate deeply, would in time establish themselves on the deserted soil,
fill the valley with verdure, and perhaps at last temper the climate, and even
call down abundant rain from the heavens. [Footnote: The date and the
doum palm, the sont and many other acacias, the caroub, the sycamore and
other trees grow in Egypt without irrigation, and would doubtless spread
through the entire valley in a few years.] But the immediate effect of
discontinuing irrigation would be, first, an immense reduction of the
evaporation from the valley in the dry season, and then a greatly augmented
dryness and heat of the atmosphere. Even the almost constant north wind—
the strength of which would be increased in consequence of these changes
—would little reduce the temperature of the narrow cleft between the
burning mountains which hem in the channel of the Nile, so that a single
year would transform the most fertile of soils to the most barren of deserts,
and render uninhabitable a territory that irrigation makes capable of
Page 568
sustaining as dense a population as has ever existed in any part of the world.
[Footnote: Wilkinson states that the total population, which, two hundred
years ago, was estimated at 4,000,000, amounted till lately to only about
1,800,000 souls, having been reduced since the year 1800 from 2,500,000
to less than 2,000,000.—Handbook for Travellers in Egypt. p. 10. The
population at the end of the year 1869 is computed at 5,215,000.—
Bollettino della Soc. Geog. Ital., vol. v., pt. iii., p. 215. This estimate
doubtless includes countries bordering on the upper Nile not embraced in
Wilkinson's statistics.] Whether man found the valley of the Nile a forest, or
such a waste as I have just described, we do not historically know. In either
case, he has not simply converted a wilderness into a garden, but has
unquestionably produced extensive climatic change. [Footnote: Ritter
supposes Egypt to have been a sandy desert when it was first occupied by
man. "The first inhabitant of the sandy valley of the Nile was a desert-
dweller, as his neighbors right and left, the Libyan, the nomade Arab, still
are. But the civilized people of Egypt transformed, by canals, the waste into
the richest granary of the world; they liberated themselves from the
shackles of the rock and sand desert, in the midst of which, by a wise
distribution of the fluid through the solid geographical form, by irrigation in
short, they created a region of culture most rich in historical
monuments."—Einleitung zur allgemeinen vergleichenden Geographie, pp.
165, 166.
This view seems to me highly improbable; for great rivers, in warm
climates, are never bordered by sandy plains. A small stream may be
swallowed up by sands, but if the volume of water is too large to be carried
off by evaporation or drank up by absorption, it saturates its banks with
moisture, and unless resisted by art, converts them into marshes covered
with aquatio vegetation. By canals and embankments, man has done much
to modify the natural distribution of the waters of the Nile; yet the annual
inundation is not his work, and the river must have overflowed its banks
[Footnote: Wilkinson states that the total population, which, two hundred
years ago, was estimated at 4,000,000, amounted till lately to only about
1,800,000 souls, having been reduced since the year 1800 from 2,500,000
to less than 2,000,000.—Handbook for Travellers in Egypt. p. 10. The
population at the end of the year 1869 is computed at 5,215,000.—
Bollettino della Soc. Geog. Ital., vol. v., pt. iii., p. 215. This estimate
doubtless includes countries bordering on the upper Nile not embraced in
Wilkinson's statistics.] Whether man found the valley of the Nile a forest, or
such a waste as I have just described, we do not historically know. In either
case, he has not simply converted a wilderness into a garden, but has
unquestionably produced extensive climatic change. [Footnote: Ritter
supposes Egypt to have been a sandy desert when it was first occupied by
man. "The first inhabitant of the sandy valley of the Nile was a desert-
dweller, as his neighbors right and left, the Libyan, the nomade Arab, still
are. But the civilized people of Egypt transformed, by canals, the waste into
the richest granary of the world; they liberated themselves from the
shackles of the rock and sand desert, in the midst of which, by a wise
distribution of the fluid through the solid geographical form, by irrigation in
short, they created a region of culture most rich in historical
monuments."—Einleitung zur allgemeinen vergleichenden Geographie, pp.
165, 166.
This view seems to me highly improbable; for great rivers, in warm
climates, are never bordered by sandy plains. A small stream may be
swallowed up by sands, but if the volume of water is too large to be carried
off by evaporation or drank up by absorption, it saturates its banks with
moisture, and unless resisted by art, converts them into marshes covered
with aquatio vegetation. By canals and embankments, man has done much
to modify the natural distribution of the waters of the Nile; yet the annual
inundation is not his work, and the river must have overflowed its banks
Page 569
and carried spontaneous vegetation with its waters, as well before as since
Egypt was first occupied by the human family. There is, indeed, some
reason to suppose that man lived upon the banks of the Nile when its
channel was much lower, and the spread of its inundations much narrower,
than at present; but wherever its flood reached, there the forest would
propagate itself, and its shores would certainly have been morasses rather
than sands.
The opinions of Ritter on this subject are not only improbable, but they
are contradictory to the little historical testimony we possess. Herodotus
informs us in Euterpe that except the province of Thebes, all Egypt, that is
to say, the whole of the Delta and of middle Egypt extending to Hemopolis
Magna in N. L. 27 degrees 45 minutes, was originally a morass. This
morass was doubtless in great part covered with trees, and hence, in the
most ancient hieroglyphical records, a tree is the sign for the cultivated land
between the desert and the channel of the Nile. In all probability, the real
change effected by human art in the superficial geography of Egypt is the
conversion of pools and marshes into dry land, by a system of transverse
dikes, which compelled the flood-water to deposit its sediment on the banks
of the river instead of carrying it to the sea. The colmate of modern Italy
were thus anticipated in ancient Egypt.]
The fields of Egypt are more regularly watered than those of any other
country bordering on the Mediterranean, except the rice-grounds in Italy,
and perhaps the marcite or winter meadows of Lombardy; but irrigation is
more or less employed throughout almost the entire basin of that sea, and is
everywhere attended with effects which, if less in degree, are analogous in
character, to those resulting from it in Egypt.
There are few things in European husbandry which surprise English or
American observers so much as the extent to which irrigation is employed
Egypt was first occupied by the human family. There is, indeed, some
reason to suppose that man lived upon the banks of the Nile when its
channel was much lower, and the spread of its inundations much narrower,
than at present; but wherever its flood reached, there the forest would
propagate itself, and its shores would certainly have been morasses rather
than sands.
The opinions of Ritter on this subject are not only improbable, but they
are contradictory to the little historical testimony we possess. Herodotus
informs us in Euterpe that except the province of Thebes, all Egypt, that is
to say, the whole of the Delta and of middle Egypt extending to Hemopolis
Magna in N. L. 27 degrees 45 minutes, was originally a morass. This
morass was doubtless in great part covered with trees, and hence, in the
most ancient hieroglyphical records, a tree is the sign for the cultivated land
between the desert and the channel of the Nile. In all probability, the real
change effected by human art in the superficial geography of Egypt is the
conversion of pools and marshes into dry land, by a system of transverse
dikes, which compelled the flood-water to deposit its sediment on the banks
of the river instead of carrying it to the sea. The colmate of modern Italy
were thus anticipated in ancient Egypt.]
The fields of Egypt are more regularly watered than those of any other
country bordering on the Mediterranean, except the rice-grounds in Italy,
and perhaps the marcite or winter meadows of Lombardy; but irrigation is
more or less employed throughout almost the entire basin of that sea, and is
everywhere attended with effects which, if less in degree, are analogous in
character, to those resulting from it in Egypt.
There are few things in European husbandry which surprise English or
American observers so much as the extent to which irrigation is employed
Page 570
in agriculture, and that, too, on soils, and with a temperature, where their
own experience would have led them to suppose it would be injurious to
vegetation rather than beneficial to it. In Switzerland, for example, grass-
grounds on the very borders of glaciers are freely irrigated, and on the
Italian slope of the Alps water is applied to meadows at heights exceeding
6,000 feet. The summers in Northern Italy, though longer, are very often not
warmer than in the Northern United States; and in ordinary years, the
summer rains are as frequent and as abundant in the former country as in
the latter. [Footnote: The mean annual precipitation in Lombardy is thirty-
six inches, of which nearly two-thirds fall during the season of irrigation.
The rain-fall is about the same in Piedmont, though the number of days in
the year classed as "rainy" is said to be but twenty-four in the former
province while it is seventy in the latter.—Baird Smith, Italian Irrigation,
vol. i., p. 196.
The necessity of irrigation in the great alluivial plain of Northern Italy is
partly explained by the fact that the superficial stratum of fine earth and
vegetable mould is very extensively underlaid by beds of pebbles and
gravel brought down by mountain torrents at a remote epoch. The water of
the surface-soil drains rapdily down into these loose beds, and passes off by
subterranean channels to some unknown point of discharge; but this
circumstance alone is not a sufficient solution. It is not possible that the
habits of vegetables, grown in countries where irrigation has been
immemorially employed, have been so changed that they require water
under conditions of soil and climate where their congeners, which have not
been thus indulgently treated, do not It is a remarkable fact that during the
season of irrigation, when large tracts of surface are almost constantly
saturated with water, there is an extraordinary dryness in the atmosphere of
Lombardy, the hygrometer standing for days together a few degrees only
above zero, while in winter the instrument indicates extreme humidity of
own experience would have led them to suppose it would be injurious to
vegetation rather than beneficial to it. In Switzerland, for example, grass-
grounds on the very borders of glaciers are freely irrigated, and on the
Italian slope of the Alps water is applied to meadows at heights exceeding
6,000 feet. The summers in Northern Italy, though longer, are very often not
warmer than in the Northern United States; and in ordinary years, the
summer rains are as frequent and as abundant in the former country as in
the latter. [Footnote: The mean annual precipitation in Lombardy is thirty-
six inches, of which nearly two-thirds fall during the season of irrigation.
The rain-fall is about the same in Piedmont, though the number of days in
the year classed as "rainy" is said to be but twenty-four in the former
province while it is seventy in the latter.—Baird Smith, Italian Irrigation,
vol. i., p. 196.
The necessity of irrigation in the great alluivial plain of Northern Italy is
partly explained by the fact that the superficial stratum of fine earth and
vegetable mould is very extensively underlaid by beds of pebbles and
gravel brought down by mountain torrents at a remote epoch. The water of
the surface-soil drains rapdily down into these loose beds, and passes off by
subterranean channels to some unknown point of discharge; but this
circumstance alone is not a sufficient solution. It is not possible that the
habits of vegetables, grown in countries where irrigation has been
immemorially employed, have been so changed that they require water
under conditions of soil and climate where their congeners, which have not
been thus indulgently treated, do not It is a remarkable fact that during the
season of irrigation, when large tracts of surface are almost constantly
saturated with water, there is an extraordinary dryness in the atmosphere of
Lombardy, the hygrometer standing for days together a few degrees only
above zero, while in winter the instrument indicates extreme humidity of
Page 571
the air, approaching to total saturation.—Baird Smith, Italian Irrigation, i.,
p. 189.
There are some atmospheric phenomena in Northern Italy, which an
American finds it hard to reconcile with what he has observed in the United
States. To an American eye, for instance, the sky of Piedmont, Lombardy,
and the northern coast of the Mediterranean, is always whitish and curdled,
and it never has the intensity and fathomless depth of the blue of his native
heavens. And yet the heat of the sun's rays, as measured by sensation, and,
at the same time, the evaporation, are greater than they would be with the
thermometer at the same point in America. I have frequently felt in Italy,
with the mercury below 60 degrees Fahrenheit, and with a mottled and
almost opaque sky, a heat of solar irradiation which I can compare to
nothing but the scorching sensation experienced in America at a
temperature twenty degrees higher, during the intervals between showers, or
before a rain, when the clear blue of the sky seems infinite in depth and
transparency. Such circumstances may create a necessity for irrigation
where it would otherwise be superfluous, if not absolutely injurious.
In speaking of the superior apparent clearness of the SKY in America, I
confine myself to the concave vault of the heavens, and do not mean to
assert that terrestrial objects are generally visible at greater distances in the
United States than in Italy. Indeed, I am rather disposed to maintain the
contrary; for though I know that the lower strata of the atmosphere in
Europe never equal in transparency the air near the earth in New Mexico,
Peru, and Chili, yet I think the accidents of the coast-line of the Riviera, as,
for example, between Nice and La Spezia, and those of the incomparable
Alpine panorama seen from Turin, are distinguishable at greater distances
than they would be in the United States.] Yet in Piedmont and Lombardy
irrigation is bestowed upon almost every crop, while in our Northern States
it is never employed at all in farming husbandry, or indeed for any purpose
p. 189.
There are some atmospheric phenomena in Northern Italy, which an
American finds it hard to reconcile with what he has observed in the United
States. To an American eye, for instance, the sky of Piedmont, Lombardy,
and the northern coast of the Mediterranean, is always whitish and curdled,
and it never has the intensity and fathomless depth of the blue of his native
heavens. And yet the heat of the sun's rays, as measured by sensation, and,
at the same time, the evaporation, are greater than they would be with the
thermometer at the same point in America. I have frequently felt in Italy,
with the mercury below 60 degrees Fahrenheit, and with a mottled and
almost opaque sky, a heat of solar irradiation which I can compare to
nothing but the scorching sensation experienced in America at a
temperature twenty degrees higher, during the intervals between showers, or
before a rain, when the clear blue of the sky seems infinite in depth and
transparency. Such circumstances may create a necessity for irrigation
where it would otherwise be superfluous, if not absolutely injurious.
In speaking of the superior apparent clearness of the SKY in America, I
confine myself to the concave vault of the heavens, and do not mean to
assert that terrestrial objects are generally visible at greater distances in the
United States than in Italy. Indeed, I am rather disposed to maintain the
contrary; for though I know that the lower strata of the atmosphere in
Europe never equal in transparency the air near the earth in New Mexico,
Peru, and Chili, yet I think the accidents of the coast-line of the Riviera, as,
for example, between Nice and La Spezia, and those of the incomparable
Alpine panorama seen from Turin, are distinguishable at greater distances
than they would be in the United States.] Yet in Piedmont and Lombardy
irrigation is bestowed upon almost every crop, while in our Northern States
it is never employed at all in farming husbandry, or indeed for any purpose
Page 572
except in kitchen-gardens, and possibly, in rare cases, in some other small
branch of agricultural industry. [Footnote: In our comparatively rainless
Western territory, irrigation is extensively and very beneficially employed.
In the Salt Lake valley and in California, hundreds if not thousands of miles
of irrigation canals have been constructed, and there is little doubt that
artificially watering the soil will soon be largely resorted to in the older
States. See valuable observations on this subject in Hayden, Preliminary
Report on Geological Survey of Wyoming, 1870, pp. 194, 195, 258-261.]
In general, it may be said that irrigation is employed only in the seasons
when the evaporating power of the sun and the capacity of the air for
absorbing humidity are greatest, or, in other words, that the soil is nowhere
artificially watered except when it is so dry that little moisture would be
evaporated from it, and, consequently, every acre of irrigated ground is so
much added to the evaporable surface of the country. When the supply of
water is unlimited, it is allowed, after serving its purpose on one field, to
run into drains, canals, or rivers. But in most regions where irrigation is
regularly employed, it is necessary to economize the water; after passing
over or through one parcel of ground, it is conducted to another; no more is
usually withdrawn from the canals at anyone point than is absorbed by the
soil it irrigates, or evaporated from it, and, consequently, it is not restored to
liquid circulation, except by infiltration or precipitation. We are safe, then,
in saying that the humidity evaporated from any artificially watered soil is
increased by a quantity bearing a large proportion to the whole amount
distributed over it, for most even of that which is absorbed by the earth is
immediately given out again either by vegetables or by evaporation; and the
hygrometrical and thermometrical condition of the atmosphere in irrigated
countries is modified proportionally to the extent of the practice.
It is not easy to ascertain precisely either the extent of surface thus
watered, or the amount of water supplied, in any given country, because
branch of agricultural industry. [Footnote: In our comparatively rainless
Western territory, irrigation is extensively and very beneficially employed.
In the Salt Lake valley and in California, hundreds if not thousands of miles
of irrigation canals have been constructed, and there is little doubt that
artificially watering the soil will soon be largely resorted to in the older
States. See valuable observations on this subject in Hayden, Preliminary
Report on Geological Survey of Wyoming, 1870, pp. 194, 195, 258-261.]
In general, it may be said that irrigation is employed only in the seasons
when the evaporating power of the sun and the capacity of the air for
absorbing humidity are greatest, or, in other words, that the soil is nowhere
artificially watered except when it is so dry that little moisture would be
evaporated from it, and, consequently, every acre of irrigated ground is so
much added to the evaporable surface of the country. When the supply of
water is unlimited, it is allowed, after serving its purpose on one field, to
run into drains, canals, or rivers. But in most regions where irrigation is
regularly employed, it is necessary to economize the water; after passing
over or through one parcel of ground, it is conducted to another; no more is
usually withdrawn from the canals at anyone point than is absorbed by the
soil it irrigates, or evaporated from it, and, consequently, it is not restored to
liquid circulation, except by infiltration or precipitation. We are safe, then,
in saying that the humidity evaporated from any artificially watered soil is
increased by a quantity bearing a large proportion to the whole amount
distributed over it, for most even of that which is absorbed by the earth is
immediately given out again either by vegetables or by evaporation; and the
hygrometrical and thermometrical condition of the atmosphere in irrigated
countries is modified proportionally to the extent of the practice.
It is not easy to ascertain precisely either the extent of surface thus
watered, or the amount of water supplied, in any given country, because
Page 573
these quantities vary with the character of the season; but there are not
many districts in Southern Europe where the management of the
arrangements for irrigation is not one of the most important branches of
agricultural labor. The eminent engineer Lombardini describes the system
of irrigation in Lombardy as, "every day in summer, diffusing over 550,000
hectares [1,375,000 acres] of land 45,000,000 cubic metres [nearly
600,000,000 cubic yards] of water, which is equal to the entire volume of
the Seine, at an ordinary flood, or a rise of three metres above the
hydrometer at the bridge of La Tournelle at Paris." [Footnote: Memorie sui
progetti per Pestensions dell' Irrigazione, etc., il Politecniso, for January,
1868, p. 6.]
Niel states the quantity of land irrigated in the former kingdom of
Sardinia, including Savoy, in 1856, at 240,000 hectares, or not much Ices
than 600,000 acres. This is about four-thirteenths of the cultivable soil of
the kingdom. According to the same author, the irrigated lands in Franco
did not exceed 100,000 hectares, or 247,000 acres, while those in Lombardy
amounted to 450,000 hectares, more than 1,100,000 acres. [Footnote: Niel,
L'Agriculture des Etats Sardes, p. 232. This estimate, it will be observed, is
275,000 acres less than that of Lombardini.]
In these three states alone, then, there were more than three thousand
square miles of artificially watered land, and if we add the irrigated soils of
the rest of Italy, [Footnote: In 1865 the total quantity of irrigated lands in
the kingdom of Italy was estimated at 1,357,677 hectares, or 2,000,000
acres, of which one-half is supplied with water by artificial canals. The
Canal Cavour adds 250,000 acres to the above amount. The extent of
artificially watered ground in Italy is consequently equal to the entire area
of the States of Delaware and Rhode Island.—See the official report, Sulle
Bonificazione, Risaie, ed Irrigazioni, 1865, p. 269.] of the Mediterranean
islands, of the Spanish peninsula, of Turkey in Europe and in Asia Minor, of
many districts in Southern Europe where the management of the
arrangements for irrigation is not one of the most important branches of
agricultural labor. The eminent engineer Lombardini describes the system
of irrigation in Lombardy as, "every day in summer, diffusing over 550,000
hectares [1,375,000 acres] of land 45,000,000 cubic metres [nearly
600,000,000 cubic yards] of water, which is equal to the entire volume of
the Seine, at an ordinary flood, or a rise of three metres above the
hydrometer at the bridge of La Tournelle at Paris." [Footnote: Memorie sui
progetti per Pestensions dell' Irrigazione, etc., il Politecniso, for January,
1868, p. 6.]
Niel states the quantity of land irrigated in the former kingdom of
Sardinia, including Savoy, in 1856, at 240,000 hectares, or not much Ices
than 600,000 acres. This is about four-thirteenths of the cultivable soil of
the kingdom. According to the same author, the irrigated lands in Franco
did not exceed 100,000 hectares, or 247,000 acres, while those in Lombardy
amounted to 450,000 hectares, more than 1,100,000 acres. [Footnote: Niel,
L'Agriculture des Etats Sardes, p. 232. This estimate, it will be observed, is
275,000 acres less than that of Lombardini.]
In these three states alone, then, there were more than three thousand
square miles of artificially watered land, and if we add the irrigated soils of
the rest of Italy, [Footnote: In 1865 the total quantity of irrigated lands in
the kingdom of Italy was estimated at 1,357,677 hectares, or 2,000,000
acres, of which one-half is supplied with water by artificial canals. The
Canal Cavour adds 250,000 acres to the above amount. The extent of
artificially watered ground in Italy is consequently equal to the entire area
of the States of Delaware and Rhode Island.—See the official report, Sulle
Bonificazione, Risaie, ed Irrigazioni, 1865, p. 269.] of the Mediterranean
islands, of the Spanish peninsula, of Turkey in Europe and in Asia Minor, of
Page 574
Syria, of Egypt and the remainder of Northern Africa, we shall see that
irrigation increases the evaporable surface of the Mediterranean basin by a
quantity bearing no inconsiderable proportion to the area naturally covered
by water within it.
Arrangements are concluded, and new plans proposed, for an immense
increase of the lands fertilized by irrigation in France and in Belgium, as
well as in Spain and Italy, and there is every reason to believe that the
artificially watered soil of the latter country will be doubled, that of France
quadrupled, before the end of this century. There can be no doubt that by
these operations man is exercising a powerful influence on the soil, on
vegetable and animal life, and on climate, and hence that in this, as in many
other fields of industry, he is truly a geographical agency. [Footnote: It
belongs rather to agriculture than to geography to discuss the quality of the
crops obtained by irrigation, or the permanent effects produced by it on the
productiveness of the soil. There is no doubt, however, that all crops which
can be raised without watering are superior in flavor and in nutritive power
to those grown by the aid of irrigation. Garden vegetables, particularly,
profusely watered, are so insipid as to be hardly eatable. Wherever
irrigation is practised, there is an almost irresistible tendency, especially
among ignorant cultivators, to carry it to excess; and in Piedmont and
Lombardy, if the supply of water is abundant, it is so liberally applied as
sometimes not only to injure the quality of the product, but to drown the
plants and diminish the actual weight of the crop. Grass-lands are perhaps
an exception to this remark, as it seems almost impossible to apply too
much water to them, provided it be kept in motion and not allowed to
stagnate on the surface. Protestor Liebig, in his Modern Agriculture, says:
"There is not to be found in chemistry a more wonderful phenomenon, one
which more confounds all human wisdom, than is presented by the soil of a
garden or field. By the simplest experiment, any one may satisfy himself
that rain-water filtered through field or garden soil does not dissolve out a
irrigation increases the evaporable surface of the Mediterranean basin by a
quantity bearing no inconsiderable proportion to the area naturally covered
by water within it.
Arrangements are concluded, and new plans proposed, for an immense
increase of the lands fertilized by irrigation in France and in Belgium, as
well as in Spain and Italy, and there is every reason to believe that the
artificially watered soil of the latter country will be doubled, that of France
quadrupled, before the end of this century. There can be no doubt that by
these operations man is exercising a powerful influence on the soil, on
vegetable and animal life, and on climate, and hence that in this, as in many
other fields of industry, he is truly a geographical agency. [Footnote: It
belongs rather to agriculture than to geography to discuss the quality of the
crops obtained by irrigation, or the permanent effects produced by it on the
productiveness of the soil. There is no doubt, however, that all crops which
can be raised without watering are superior in flavor and in nutritive power
to those grown by the aid of irrigation. Garden vegetables, particularly,
profusely watered, are so insipid as to be hardly eatable. Wherever
irrigation is practised, there is an almost irresistible tendency, especially
among ignorant cultivators, to carry it to excess; and in Piedmont and
Lombardy, if the supply of water is abundant, it is so liberally applied as
sometimes not only to injure the quality of the product, but to drown the
plants and diminish the actual weight of the crop. Grass-lands are perhaps
an exception to this remark, as it seems almost impossible to apply too
much water to them, provided it be kept in motion and not allowed to
stagnate on the surface. Protestor Liebig, in his Modern Agriculture, says:
"There is not to be found in chemistry a more wonderful phenomenon, one
which more confounds all human wisdom, than is presented by the soil of a
garden or field. By the simplest experiment, any one may satisfy himself
that rain-water filtered through field or garden soil does not dissolve out a
Page 575
trace of potash, silicic acid, ammonia, or phosphoric acid. The soil does not
give up to the water one particle of the food of plants which it contains. The
most continuous rains cannot remove from the field, except mechanically,
any of the essential constituents of ite fertility." "The soil not only retains
firmly all the food of plants which is actually in it, but its power to preserve
all that may be useful to them extends much farther. If rain or other water
holding in solution ammonia, potash, and phosphoric and silicic acids, be
brought in contact with soil, these substances disappear almost immediately
from the solution; the soil withdraws them from the water. Only such
substances are completely withdrawn by the soil as are indispensable
articles of food for plants; all others remain wholly or in part in solution."
These opinions were confirmed, soon after their promulgation, by the
experimental researches of other chemists, but are now questioned, and they
are not strictly in accordance with the alleged experience of agriculturists in
those parts of Italy where irrigation is most successfully applied. They
believe that the constituents of vegetable growth are washed out of the soil
by excessive and long-continued watering. They consider it also established
as a fact of observation, that water which has flowed through or over rich
ground is more valuable for irrigation than water from the same source,
which has not been impregnated with fertilizing substances by passing
through soils containing them; and, on the other hand, that water, rich in the
elements of vegetation, parts with them in serving to irrigate a poor soil,
and is therefore less valuable as a fertilizer of lower grounds to which it
may afterward be conducted. See Baird Smith, Italian Irrigation, i., p. 25;
Scott Moncrieff, Irrigation in Southern Europe, pp. 34, 87, 89; Lombardini,
Sulle Inondazioni etc., p. 73; Mangon, Les Irrigations, p. 48.
The practice of irrigation—except in mountainous countries where
springs and rivulets are numerous—is attended with very serious
economical, social, and political evils. The construction of canals and their
give up to the water one particle of the food of plants which it contains. The
most continuous rains cannot remove from the field, except mechanically,
any of the essential constituents of ite fertility." "The soil not only retains
firmly all the food of plants which is actually in it, but its power to preserve
all that may be useful to them extends much farther. If rain or other water
holding in solution ammonia, potash, and phosphoric and silicic acids, be
brought in contact with soil, these substances disappear almost immediately
from the solution; the soil withdraws them from the water. Only such
substances are completely withdrawn by the soil as are indispensable
articles of food for plants; all others remain wholly or in part in solution."
These opinions were confirmed, soon after their promulgation, by the
experimental researches of other chemists, but are now questioned, and they
are not strictly in accordance with the alleged experience of agriculturists in
those parts of Italy where irrigation is most successfully applied. They
believe that the constituents of vegetable growth are washed out of the soil
by excessive and long-continued watering. They consider it also established
as a fact of observation, that water which has flowed through or over rich
ground is more valuable for irrigation than water from the same source,
which has not been impregnated with fertilizing substances by passing
through soils containing them; and, on the other hand, that water, rich in the
elements of vegetation, parts with them in serving to irrigate a poor soil,
and is therefore less valuable as a fertilizer of lower grounds to which it
may afterward be conducted. See Baird Smith, Italian Irrigation, i., p. 25;
Scott Moncrieff, Irrigation in Southern Europe, pp. 34, 87, 89; Lombardini,
Sulle Inondazioni etc., p. 73; Mangon, Les Irrigations, p. 48.
The practice of irrigation—except in mountainous countries where
springs and rivulets are numerous—is attended with very serious
economical, social, and political evils. The construction of canals and their
Page 576
immensely ramified branches, and the grading and scarping of the ground
to be watered, are always expensive operations, and they very often require
an amount of capital which can be commanded only by the state, by
moneyed corporations, or by very wealthy proprietors; the capacity of the
canals must be calculated with reference to the area intended to be irrigated,
and when they and their branches are once constructed, it in very difficult to
extend them, or to accommodate any of their original arrangements to
changes in the condition of the soil, or in the modes or objects of
cultivation; the flow of the water being limited by the abundance of the
source or the capacity of the canals, the individual proprietor cannot be
allowed to withdraw water at will, according to his own private interest or
convenience, but both the time and the quantity of supply must be regulated
by a general system applicable, as far as may be, to the whole area irrigated
by the same canal, and every cultivator must conform his industry to a plan
which may be quite at variance with his special objects or with his views of
good husbandry. The clashing interests and the jealousies of proprietors
depending on the same means of supply are a source of incessant contention
and litigation, and the caprices or partialities of the officers who control, or
of contractors who farm, the canals, lead not unfrequently to ruinous
injustice towards individual landholders. These circumstances discourage
the division of the soil into small properties, and there is a constant
tendency to the accumulation of large estates of irrigated land in the hands
of great capitalists, and consequently to the dispossession of the small
cultivators, who pass from the condition of owners of the land to that of
hireling tillers.
Though farmers are no longer yeomen, but peasants. Having no interest
in the soil which composes their country, they are virtually expatriated, and
the middle class, which ought to constitute the real physical and moral
strength of the land, ceases to exist as a rural estate, and is found only
among the professional, the mercantile, and the industrial population of the
to be watered, are always expensive operations, and they very often require
an amount of capital which can be commanded only by the state, by
moneyed corporations, or by very wealthy proprietors; the capacity of the
canals must be calculated with reference to the area intended to be irrigated,
and when they and their branches are once constructed, it in very difficult to
extend them, or to accommodate any of their original arrangements to
changes in the condition of the soil, or in the modes or objects of
cultivation; the flow of the water being limited by the abundance of the
source or the capacity of the canals, the individual proprietor cannot be
allowed to withdraw water at will, according to his own private interest or
convenience, but both the time and the quantity of supply must be regulated
by a general system applicable, as far as may be, to the whole area irrigated
by the same canal, and every cultivator must conform his industry to a plan
which may be quite at variance with his special objects or with his views of
good husbandry. The clashing interests and the jealousies of proprietors
depending on the same means of supply are a source of incessant contention
and litigation, and the caprices or partialities of the officers who control, or
of contractors who farm, the canals, lead not unfrequently to ruinous
injustice towards individual landholders. These circumstances discourage
the division of the soil into small properties, and there is a constant
tendency to the accumulation of large estates of irrigated land in the hands
of great capitalists, and consequently to the dispossession of the small
cultivators, who pass from the condition of owners of the land to that of
hireling tillers.
Though farmers are no longer yeomen, but peasants. Having no interest
in the soil which composes their country, they are virtually expatriated, and
the middle class, which ought to constitute the real physical and moral
strength of the land, ceases to exist as a rural estate, and is found only
among the professional, the mercantile, and the industrial population of the
Page 577
cities.—See, on the difficulty of regulating irrigation by law, Negri, Idea su
una Legge in materia di Acqua, 1864; and Agmard, Irrigations du Midi de
L'Europe' where curious and important remarks on the laws and usages of
the Spanish Moors and the Spaniards, in respect to irrigation, will be found.
The Moors were so careful in maintaining the details of their system, that
they kept in publio offices bronze models of their dams and sluices, as
guides for repairs and rebuilding. Some of these models are still preserved.
—Ibidem, pp. 204, 205. For an account of recent irrigation works in Spain,
see Spon, Dictionary of Engineering, article Irrigation. As near as can be
ascertained, the amount of water applied to irrigated lands is scarcely
anywhere less than the total precipitation during the season of vegetable
growth, and in general it much exceeds that quantity. In grass-grounds and
in field-culture it ranges from 27 or 28 to 60 inches, while in smaller crops,
tilled by hand-labor, it is sometimes carried as high as 300 inches.
[Footnote: Niel, Agriculture des Etata Sardes, p. 237. Lombardini's
computation just given allows eighty-one cubic metres per day to the
hectare [two hundred and sixty cubic yards to the acre], which, supposing
the season of irrigation to be one hundred days, in equal to a precipitation of
thirty-two inches. But in Lombardy, water in applied to some crops during a
longer period than one hundred days; and in the marcite it flows over the
ground even in winter. According to Boussingault (Economie Rurale, ii., p.
240), grass-grounds ought to receive, in Germany, twenty-one centimetres
of water per week, and with less than half that quantity it is not advisable to
incur the expense of supplying it. The ground is irrigated twenty-five or
thirty times, and if the full quantity of twenty-one centimetres is applied, it
receives more than two hundred inches of water, or six times the total
amount of precipitation. Puvis, quoted by Boussingault, after much research
comes to the conclusion that a proper quantity is twenty centimetres [eight
inches] applied twenty-five or thirty times, which corresponds with the
estimate just stated. Puvis adds—and, as our author thinks, with reason—
una Legge in materia di Acqua, 1864; and Agmard, Irrigations du Midi de
L'Europe' where curious and important remarks on the laws and usages of
the Spanish Moors and the Spaniards, in respect to irrigation, will be found.
The Moors were so careful in maintaining the details of their system, that
they kept in publio offices bronze models of their dams and sluices, as
guides for repairs and rebuilding. Some of these models are still preserved.
—Ibidem, pp. 204, 205. For an account of recent irrigation works in Spain,
see Spon, Dictionary of Engineering, article Irrigation. As near as can be
ascertained, the amount of water applied to irrigated lands is scarcely
anywhere less than the total precipitation during the season of vegetable
growth, and in general it much exceeds that quantity. In grass-grounds and
in field-culture it ranges from 27 or 28 to 60 inches, while in smaller crops,
tilled by hand-labor, it is sometimes carried as high as 300 inches.
[Footnote: Niel, Agriculture des Etata Sardes, p. 237. Lombardini's
computation just given allows eighty-one cubic metres per day to the
hectare [two hundred and sixty cubic yards to the acre], which, supposing
the season of irrigation to be one hundred days, in equal to a precipitation of
thirty-two inches. But in Lombardy, water in applied to some crops during a
longer period than one hundred days; and in the marcite it flows over the
ground even in winter. According to Boussingault (Economie Rurale, ii., p.
240), grass-grounds ought to receive, in Germany, twenty-one centimetres
of water per week, and with less than half that quantity it is not advisable to
incur the expense of supplying it. The ground is irrigated twenty-five or
thirty times, and if the full quantity of twenty-one centimetres is applied, it
receives more than two hundred inches of water, or six times the total
amount of precipitation. Puvis, quoted by Boussingault, after much research
comes to the conclusion that a proper quantity is twenty centimetres [eight
inches] applied twenty-five or thirty times, which corresponds with the
estimate just stated. Puvis adds—and, as our author thinks, with reason—
Page 578
that this amount might be doubled without disadvantage.—Ibidem, ii., p.
248, 249. In some parts of France this quantity is immensely exceeded, and
it is very important to observe, with reference to the employment of
irrigation in our Northern States, that water is most freely supplied in the
COLDER provinces. Thus, in the Vosges, meadows are literally flooded for
weeks together, and while in the department of Vancluse a meadow may
receive, in five waterings of six and a half hours each, twenty-one inches of
wnter, in the Vosges it might be deluged for twenty-four hundred hours in
six applications, the enormous quantity of thirteen hundred feet of water
flowing over it. See the important work of Herve Mangon, Sur l'emploi des
eaux dans les Irrigations, chap. ix. Boussingault observes that rain-water is
vastly more fertilizing than the water of irrigating canals, and therefore the
supply of the latter must be greater. This is explained partly by the different
character of the substances held in solution or suspension by the waters of
the earth and of the sky, partly by the higher temperature of the latter, and,
possibly, partly also by the mode of application—the rain being finely
divided in its fall or by striking plants on the ground, river-water flowing in
a continuous sheet.
248, 249. In some parts of France this quantity is immensely exceeded, and
it is very important to observe, with reference to the employment of
irrigation in our Northern States, that water is most freely supplied in the
COLDER provinces. Thus, in the Vosges, meadows are literally flooded for
weeks together, and while in the department of Vancluse a meadow may
receive, in five waterings of six and a half hours each, twenty-one inches of
wnter, in the Vosges it might be deluged for twenty-four hundred hours in
six applications, the enormous quantity of thirteen hundred feet of water
flowing over it. See the important work of Herve Mangon, Sur l'emploi des
eaux dans les Irrigations, chap. ix. Boussingault observes that rain-water is
vastly more fertilizing than the water of irrigating canals, and therefore the
supply of the latter must be greater. This is explained partly by the different
character of the substances held in solution or suspension by the waters of
the earth and of the sky, partly by the higher temperature of the latter, and,
possibly, partly also by the mode of application—the rain being finely
divided in its fall or by striking plants on the ground, river-water flowing in
a continuous sheet.
Page 579
The temperature of the water is thought even more important than its
composition. The sources which irrigate the marcite of Lombardy—
meadows so fertile that less than an acre furnishes grass for a cow the
whole year—are very warm. The ground watered by them never freezes,
and a first crop, for soiling, is cut from it in January or February. The Canal
Cavour—which takes its supply chiefly from the Po at Chivasso, fourteen
or fifteen miles below Turin—furnishes water of much higher fertilizing
power than that derived from the Dora Baltea and the Sesia, both because it
is warmer, and because it transports a more abundant and a richer sediment
than the latter streams, which are fed by Alpine ice-fields and melting
snows, and which flow, for long distances, in channels ground smooth and
bare by ancient glaciers and not now contributing much vegetable mould or
fine slime to their waters.]
The rice-grounds and the marcite of Lombardy are not included in these
estimates of the amount of water applied. [Footnote: About one-seventh of
the water which flows over the marcite is absorbed by the soil of those
meadows or evaporated from their surface, and consequently six-sevenths
of the supply remain for use on ground at lower levels.] The meteorological
effect of irrigation on a large scale, which would seem prima facie most
probable, would be an increase of precipitation in the region watered.
[Footnote: On the pluviometric effect of irrigation, see Lombardini, Sulle
Inondazioni, etc., p. 72, 74; the same author, Essai Hydrologique sur le Nil,
p. 32; Messedaglia, Analisi dell' opera di Champion, pp. 96, 97, note; and
Baird Smith, Italian Irrigation, i., pp. 189, 190.
In an article in Aus der Natur, vol. 57, p. 443, it is stated that the rain on
the Isthmus of Suez has increased since the opening of the canal, and has
enlarged the evaporable surface of the country; but this cannot be accepted
as an established fact without further evidence.] Hitherto scientific
composition. The sources which irrigate the marcite of Lombardy—
meadows so fertile that less than an acre furnishes grass for a cow the
whole year—are very warm. The ground watered by them never freezes,
and a first crop, for soiling, is cut from it in January or February. The Canal
Cavour—which takes its supply chiefly from the Po at Chivasso, fourteen
or fifteen miles below Turin—furnishes water of much higher fertilizing
power than that derived from the Dora Baltea and the Sesia, both because it
is warmer, and because it transports a more abundant and a richer sediment
than the latter streams, which are fed by Alpine ice-fields and melting
snows, and which flow, for long distances, in channels ground smooth and
bare by ancient glaciers and not now contributing much vegetable mould or
fine slime to their waters.]
The rice-grounds and the marcite of Lombardy are not included in these
estimates of the amount of water applied. [Footnote: About one-seventh of
the water which flows over the marcite is absorbed by the soil of those
meadows or evaporated from their surface, and consequently six-sevenths
of the supply remain for use on ground at lower levels.] The meteorological
effect of irrigation on a large scale, which would seem prima facie most
probable, would be an increase of precipitation in the region watered.
[Footnote: On the pluviometric effect of irrigation, see Lombardini, Sulle
Inondazioni, etc., p. 72, 74; the same author, Essai Hydrologique sur le Nil,
p. 32; Messedaglia, Analisi dell' opera di Champion, pp. 96, 97, note; and
Baird Smith, Italian Irrigation, i., pp. 189, 190.
In an article in Aus der Natur, vol. 57, p. 443, it is stated that the rain on
the Isthmus of Suez has increased since the opening of the canal, and has
enlarged the evaporable surface of the country; but this cannot be accepted
as an established fact without further evidence.] Hitherto scientific
Page 580
observation has recorded no such increase, but in a question of so purely
local a character, we must ascribe very great importance to a consideration
which I have noticed elsewhere, but which, has been frequently overlooked
by meteorologists, namely, that vapors exhaled in one district may very
probably be condensed and precipitated in another very distant from their
source. If then it were proved that an extension of irrigated soil was not
followed by an increase of rain-fall in the same territory, the probability that
the precipitation was augmented SOMEWHERE would not be in the least
diminished.
But though we cannot show that in the irrigated portions of Italy the
summer rain is more abundant than it was before irrigation was practised—
for we know nothing of the meteorological conditions of that country at so
remote a period—the fact that there is a very considerable precipitation in
the summer months in Lombardy is a strong argument in favor of such
increase. In the otherwise similar climate of Rumelia and of much of Asia
Minor, irrigation is indeed practiced, but in a relatively small proportion. In
those provinces there is little or no summer rain. Is it not highly probable
that the difference between Italy and Turkey in this respect is to be ascribed,
in part at least, to extensive irrigation in the former country, and the want of
it in the latter It is true that, in its accessible strata, the atmosphere of
Lombardy is extremely dry during the period of irrigation, but it receives an
immense quantity of moisture by the evaporation from the watered soil, and
the rapidity with which the aqueous vapor is carried up to higher regions—
where, if not driven elsewhere by the wind, it would be condensed by the
cold into drops of rain or at least visible clouds—is the reason why it is so
little perceptible in the air near the ground. [Footnote: Is not the mottled
appearance of the upper atmosphere in Italy, which I have already noticed,
perhaps due in part to the condensation of the aqueous vapor exhaled by
watered ground ]
local a character, we must ascribe very great importance to a consideration
which I have noticed elsewhere, but which, has been frequently overlooked
by meteorologists, namely, that vapors exhaled in one district may very
probably be condensed and precipitated in another very distant from their
source. If then it were proved that an extension of irrigated soil was not
followed by an increase of rain-fall in the same territory, the probability that
the precipitation was augmented SOMEWHERE would not be in the least
diminished.
But though we cannot show that in the irrigated portions of Italy the
summer rain is more abundant than it was before irrigation was practised—
for we know nothing of the meteorological conditions of that country at so
remote a period—the fact that there is a very considerable precipitation in
the summer months in Lombardy is a strong argument in favor of such
increase. In the otherwise similar climate of Rumelia and of much of Asia
Minor, irrigation is indeed practiced, but in a relatively small proportion. In
those provinces there is little or no summer rain. Is it not highly probable
that the difference between Italy and Turkey in this respect is to be ascribed,
in part at least, to extensive irrigation in the former country, and the want of
it in the latter It is true that, in its accessible strata, the atmosphere of
Lombardy is extremely dry during the period of irrigation, but it receives an
immense quantity of moisture by the evaporation from the watered soil, and
the rapidity with which the aqueous vapor is carried up to higher regions—
where, if not driven elsewhere by the wind, it would be condensed by the
cold into drops of rain or at least visible clouds—is the reason why it is so
little perceptible in the air near the ground. [Footnote: Is not the mottled
appearance of the upper atmosphere in Italy, which I have already noticed,
perhaps due in part to the condensation of the aqueous vapor exhaled by
watered ground ]
Page 581
But the question of an influence on temperature rests on a different
ground; for though the condensation of vapor may not take place within
days of time and degrees of distance from the hour and the place where it
was exhaled from the surface, a local refrigeration must necessarily
accompany a local evaporation. Hence, though the summer temperature of
Lombardy is high, we are warranted in affirming that it must have been still
higher before the introduction of irrigation, and would again become so if
that practice were discontinued. [Footnote: I do not know that observations
have been made on the thermometric influence of irrigation, but I have
often noticed that, on the irrigated plains of Piedmont ten miles south of
Turin, the morning temperature in summer was several degrees below that
marked at the Observatory in the city.]
The quantity of water artificially withdrawn from running streams for the
purpose of irrigation is such as very sensibly to affect their volume, and it
is, therefore, an important element in the geography of rivers. Brooks of no
trifling current are often wholly diverted from their natural channels to
supply the canals, and their entire mass of water is completely absorbed or
evaporated, so that only such proportion as is transmitted by infiltration
reaches the river they originally fed. Irrigation, therefore, diminishes great
rivers in warm countries by cutting off their sources of supply as well as by
direct abstraction of water from their main channels. We have just seen that
the system of irrigation in Lombardy deprives the Po of a quantity of water
equal to the total delivery of the Seine at ordinary flood, or, in other words,
of the equivalent of a tributary navigable for hundreds of miles by vessels
of considerable burden.
The new canals executed and projected will greatly increase the loss. The
water required for irrigation in Egypt is less than would be supposed from
the exceeding rapidity of evaporation in that arid climate; for the soil is
thoroughly saturated during the inundation, and infiltration from the Nile
ground; for though the condensation of vapor may not take place within
days of time and degrees of distance from the hour and the place where it
was exhaled from the surface, a local refrigeration must necessarily
accompany a local evaporation. Hence, though the summer temperature of
Lombardy is high, we are warranted in affirming that it must have been still
higher before the introduction of irrigation, and would again become so if
that practice were discontinued. [Footnote: I do not know that observations
have been made on the thermometric influence of irrigation, but I have
often noticed that, on the irrigated plains of Piedmont ten miles south of
Turin, the morning temperature in summer was several degrees below that
marked at the Observatory in the city.]
The quantity of water artificially withdrawn from running streams for the
purpose of irrigation is such as very sensibly to affect their volume, and it
is, therefore, an important element in the geography of rivers. Brooks of no
trifling current are often wholly diverted from their natural channels to
supply the canals, and their entire mass of water is completely absorbed or
evaporated, so that only such proportion as is transmitted by infiltration
reaches the river they originally fed. Irrigation, therefore, diminishes great
rivers in warm countries by cutting off their sources of supply as well as by
direct abstraction of water from their main channels. We have just seen that
the system of irrigation in Lombardy deprives the Po of a quantity of water
equal to the total delivery of the Seine at ordinary flood, or, in other words,
of the equivalent of a tributary navigable for hundreds of miles by vessels
of considerable burden.
The new canals executed and projected will greatly increase the loss. The
water required for irrigation in Egypt is less than would be supposed from
the exceeding rapidity of evaporation in that arid climate; for the soil is
thoroughly saturated during the inundation, and infiltration from the Nile
Page 582
continues to supply a considerable amount of humidity in the dryest season.
Linant Bey computed that, in the Delta, fifteen and one-third cubic yards
per day sufficed to irrigate an acre. If we suppose water to be applied for
one hundred and fifty days during the season of growth, this would be
equivalent to a total precipitation of about seventeen inches and one-third.
Taking the area of actually cultivated soil in Egypt at the estimate of
4,500,000 acres, and the average amount of water daily applied in both
Upper and Lower Egypt at twelve hundredths of an inch in depth, we have
an abstraction of about 74,000,000 cubic yards, which—the mean daily
delivery of the Nile being in round numbers 320,000,000 cubic yards—is
twenty-three per cent of the average quantity of water contributed to the
Mediterranean by that river. [Footnote: The proportion of the waters of the
Nile withdrawn for irrigation is greater than this calculation makes it. The
quantity required for an acre is less in the Delta than in Upper Egypt, both
because the soil of the Delta, to which Linant Bey's estimate applies, lies
little higher than the surface of the river, and is partly saturated by
infiltration, and because near the sea, in N. L. 30 degrees, evaporation is
much less rapid than it is several degrees southwards and in the vicinity of a
parched desert.]
In estimating the effect of this abstraction of water upon the volume of
great rivers, especially in temperate climates and in countries with a hilly
surface, we must remember that all the water thus withdrawn—except that
which is absorbed by vegetation, that which enters into new inorganic
compounds, and that which is carried off by evaporation—is finally
restored to the original current by superficial flow or by infiltration. It is
generally estimated that from one-third to one-half of the water applied to
the fields is absorbed by the earth, and this, with the deductions just given,
is returned to the river by direct infiltration, or descends through invisible
channels to moisten lower grounds, and thence in part escapes again into
the bed of the river, by similar conduits, or in the form of springs and
Linant Bey computed that, in the Delta, fifteen and one-third cubic yards
per day sufficed to irrigate an acre. If we suppose water to be applied for
one hundred and fifty days during the season of growth, this would be
equivalent to a total precipitation of about seventeen inches and one-third.
Taking the area of actually cultivated soil in Egypt at the estimate of
4,500,000 acres, and the average amount of water daily applied in both
Upper and Lower Egypt at twelve hundredths of an inch in depth, we have
an abstraction of about 74,000,000 cubic yards, which—the mean daily
delivery of the Nile being in round numbers 320,000,000 cubic yards—is
twenty-three per cent of the average quantity of water contributed to the
Mediterranean by that river. [Footnote: The proportion of the waters of the
Nile withdrawn for irrigation is greater than this calculation makes it. The
quantity required for an acre is less in the Delta than in Upper Egypt, both
because the soil of the Delta, to which Linant Bey's estimate applies, lies
little higher than the surface of the river, and is partly saturated by
infiltration, and because near the sea, in N. L. 30 degrees, evaporation is
much less rapid than it is several degrees southwards and in the vicinity of a
parched desert.]
In estimating the effect of this abstraction of water upon the volume of
great rivers, especially in temperate climates and in countries with a hilly
surface, we must remember that all the water thus withdrawn—except that
which is absorbed by vegetation, that which enters into new inorganic
compounds, and that which is carried off by evaporation—is finally
restored to the original current by superficial flow or by infiltration. It is
generally estimated that from one-third to one-half of the water applied to
the fields is absorbed by the earth, and this, with the deductions just given,
is returned to the river by direct infiltration, or descends through invisible
channels to moisten lower grounds, and thence in part escapes again into
the bed of the river, by similar conduits, or in the form of springs and
Page 583
rivulets. Interesting observations have lately been made on this subject in
France and important practical results arrived at. It was maintained that
mountain irrigation is not ultimately injurious to that of the plains below,
because lands liberally watered in the spring, when the supply is abundant,
act as reservoirs, storing up by absorption water which afterwards filters
down to lower grounds or escapes into the channel of the river and keeps up
its current in the dry summer months, so as to compensate for what, during
those months, is withdrawn from it for upland irrigation. Careful
investigation showed that though this proposition is not universally true, it
is so in many cases, and there can be no doubt that the loss in the volume of
rivers by the abstraction of water for irrigation is very considerably less
than the measure of the quantity withdrawn. [Footnote: See Vigan, Etude
sur les Irrigations, Paris, 1867; and Scott Moncrieff, Irrigation in Southern
Europe, pp. 89, 90.
The brook Ain Musa, which runs through the ruined city of Petra and
finally disappears in the sands of Wadi el Araba, is a considerable stream in
winter, and the inhabitants of that town were obliged to excavate a tunnel
through the rock near the right bank, just above the upper entrance of the
narrow Sik, to discharge a part of its swollen current. The sagacity of Dr.
Robinson detected the necessity of this measure, though the tunnel, the
mouth of which was hidden by brushwood, was not discovered till some
time after his visit. I even noticed, near the arch that crosses the Sik,
unequivocal remains of a sluice by which the water was diverted to the
tunnel. Immense labor was also expended in widening the natural channel
at several points below the town, to prevent the damming up and setting
back of the water—a fact I believe not hitherto noticed by travellers.
The Fellahheen above Petra still employ the waters of Ain Musa for
irrigation, and in summer the superficial current is wholly diverted from its
natural channel for that purpose. At this season, the bed of the brook, which
France and important practical results arrived at. It was maintained that
mountain irrigation is not ultimately injurious to that of the plains below,
because lands liberally watered in the spring, when the supply is abundant,
act as reservoirs, storing up by absorption water which afterwards filters
down to lower grounds or escapes into the channel of the river and keeps up
its current in the dry summer months, so as to compensate for what, during
those months, is withdrawn from it for upland irrigation. Careful
investigation showed that though this proposition is not universally true, it
is so in many cases, and there can be no doubt that the loss in the volume of
rivers by the abstraction of water for irrigation is very considerably less
than the measure of the quantity withdrawn. [Footnote: See Vigan, Etude
sur les Irrigations, Paris, 1867; and Scott Moncrieff, Irrigation in Southern
Europe, pp. 89, 90.
The brook Ain Musa, which runs through the ruined city of Petra and
finally disappears in the sands of Wadi el Araba, is a considerable stream in
winter, and the inhabitants of that town were obliged to excavate a tunnel
through the rock near the right bank, just above the upper entrance of the
narrow Sik, to discharge a part of its swollen current. The sagacity of Dr.
Robinson detected the necessity of this measure, though the tunnel, the
mouth of which was hidden by brushwood, was not discovered till some
time after his visit. I even noticed, near the arch that crosses the Sik,
unequivocal remains of a sluice by which the water was diverted to the
tunnel. Immense labor was also expended in widening the natural channel
at several points below the town, to prevent the damming up and setting
back of the water—a fact I believe not hitherto noticed by travellers.
The Fellahheen above Petra still employ the waters of Ain Musa for
irrigation, and in summer the superficial current is wholly diverted from its
natural channel for that purpose. At this season, the bed of the brook, which
Page 584
is composed of pebbles, gravel, and sand, is dry in the Sik and through the
town; but the infiltration is such that water is generally found by digging to
a small depth in the channel. Observing these facts in a visit to Petra in the
summer, I was curious to know whether the subterranean waters escaped
again to daylight, and I followed the ravine below the town for a long
distance. Not very far from the upper entrance of the ravine, arborescent
vegetation appeared upon its bottom, and as soon as the ground was well
shaded, a thread of water burst out. This was joined by others a little lower
down, and, at the distance of a mile from the town, a strong current was
formed and ran down towards Wadi el Araba.
Similar facts are observed in all countries where the superficial current of
water-courses is diverted from their bed for irrigation, but this case is of
special interest because it shows the extent of absorption and infiltration
even in the torrid climate of Arabia. See Baird Smith, Italian Irrigation, vol.
i., pp. 172, 386 and 387.] Irrigation, as employed for certain special
purposes in Europe and America, is productive of very prejudicial climatic
effects. I refer particularly to the cultivation of rice in the Southern States of
the American Union and in Italy. The climate of the Southern States is in
general not necessarily unhealthy for the white man, but he can scarcely
sleep a single night in the vicinity of the rice-grounds without being
attacked by a dangerous fever. The neighborhood of the rice-fields is
possibly less pestilential in Lombardy and Piedmont than in South Carolina
and Georgia, but still very insalubrious to both man and beast. "Not only
does the population decrease where rice is grown," says Escourron-
Milliago, "but even the flocks are attacked by typhus. In the rice-grounds
the soil is divided into compartments rising in gradual succession to the
level of the irrigating canal, in order that the water, after having flowed one
field, may be drawn off to another, and thus a single current serve for
several compartments, the lowest field, of course, still being higher than the
ditch which at last drains both it and the adjacent soil. This arrangement
town; but the infiltration is such that water is generally found by digging to
a small depth in the channel. Observing these facts in a visit to Petra in the
summer, I was curious to know whether the subterranean waters escaped
again to daylight, and I followed the ravine below the town for a long
distance. Not very far from the upper entrance of the ravine, arborescent
vegetation appeared upon its bottom, and as soon as the ground was well
shaded, a thread of water burst out. This was joined by others a little lower
down, and, at the distance of a mile from the town, a strong current was
formed and ran down towards Wadi el Araba.
Similar facts are observed in all countries where the superficial current of
water-courses is diverted from their bed for irrigation, but this case is of
special interest because it shows the extent of absorption and infiltration
even in the torrid climate of Arabia. See Baird Smith, Italian Irrigation, vol.
i., pp. 172, 386 and 387.] Irrigation, as employed for certain special
purposes in Europe and America, is productive of very prejudicial climatic
effects. I refer particularly to the cultivation of rice in the Southern States of
the American Union and in Italy. The climate of the Southern States is in
general not necessarily unhealthy for the white man, but he can scarcely
sleep a single night in the vicinity of the rice-grounds without being
attacked by a dangerous fever. The neighborhood of the rice-fields is
possibly less pestilential in Lombardy and Piedmont than in South Carolina
and Georgia, but still very insalubrious to both man and beast. "Not only
does the population decrease where rice is grown," says Escourron-
Milliago, "but even the flocks are attacked by typhus. In the rice-grounds
the soil is divided into compartments rising in gradual succession to the
level of the irrigating canal, in order that the water, after having flowed one
field, may be drawn off to another, and thus a single current serve for
several compartments, the lowest field, of course, still being higher than the
ditch which at last drains both it and the adjacent soil. This arrangement
Page 585
gives a certain force of hydrostatic pressure to the water with which the rice
is irrigated, and the infiltration from these fields is said to extend through
neighboring grounds, sometimes to the distance of not less than a
myriametre, or six English miles, and to be destructive to crops and even
trees reached by it. Land thus affected can no longer be employed for any
purpose but growing rice, and when prepared for that crop, it propagates
still further the evils under which it had itself suffered, and, of course, the
mischief is a growing one." [Footnote: Escourrou-Milliago, D'Italie a
propos de l'Exposition de Paris, 1856, p. 92. According to an article in the
Gazzetto di Torino for the 17th of January, 1869, the deaths from malarious
fever in the Canavese district—which is asserted to have been altogether
free from this disease before the recent introduction of rice-culture—
between the 1st of January and the 15th of October, 1868, were two
thousand two hundred and fifty. The extent of the injurious influence of this
very lucrative branch of rural industry in Italy is contested by the rice-
growers. But see Secondo Laura, Le Risaje, Torino, 1869; Selmi, Il Miasma
Palustre, p. 89; and especially Carlo Livi, Della coltivazione del Riso in
Italia, in the Nuova Antologia for July, 1871, p. 599 et seqq. According to
official statistics, the rice-grounds of Italy, including the islands, amounted
in 1866 to 450,000 acres. It is an interesting fact in relation to geographical
and climatic conditions, that while little rice is cultivated SOUTH of N. L.
44 degrees in Italy, little is grown in the United States NORTH of 35
degrees. To the southward of the great alluvial plain of the Po, the surface is
in general too much broken to admit of the formation of level fields of
much extent, and where the ground is suitable, the supply of water is often
insufficient.
The Moors introduced the cultivation of rice into Spain at an early period
of their dominion in that country. The Spaniards sowed rice in Lombardy
and in the Neapolitan territory in the 16th century; but besides the want of
water and of level ground convenient for irrigation, rice-husbandry has
is irrigated, and the infiltration from these fields is said to extend through
neighboring grounds, sometimes to the distance of not less than a
myriametre, or six English miles, and to be destructive to crops and even
trees reached by it. Land thus affected can no longer be employed for any
purpose but growing rice, and when prepared for that crop, it propagates
still further the evils under which it had itself suffered, and, of course, the
mischief is a growing one." [Footnote: Escourrou-Milliago, D'Italie a
propos de l'Exposition de Paris, 1856, p. 92. According to an article in the
Gazzetto di Torino for the 17th of January, 1869, the deaths from malarious
fever in the Canavese district—which is asserted to have been altogether
free from this disease before the recent introduction of rice-culture—
between the 1st of January and the 15th of October, 1868, were two
thousand two hundred and fifty. The extent of the injurious influence of this
very lucrative branch of rural industry in Italy is contested by the rice-
growers. But see Secondo Laura, Le Risaje, Torino, 1869; Selmi, Il Miasma
Palustre, p. 89; and especially Carlo Livi, Della coltivazione del Riso in
Italia, in the Nuova Antologia for July, 1871, p. 599 et seqq. According to
official statistics, the rice-grounds of Italy, including the islands, amounted
in 1866 to 450,000 acres. It is an interesting fact in relation to geographical
and climatic conditions, that while little rice is cultivated SOUTH of N. L.
44 degrees in Italy, little is grown in the United States NORTH of 35
degrees. To the southward of the great alluvial plain of the Po, the surface is
in general too much broken to admit of the formation of level fields of
much extent, and where the ground is suitable, the supply of water is often
insufficient.
The Moors introduced the cultivation of rice into Spain at an early period
of their dominion in that country. The Spaniards sowed rice in Lombardy
and in the Neapolitan territory in the 16th century; but besides the want of
water and of level ground convenient for irrigation, rice-husbandry has
Page 586
proved so much more pestilential in Southern than in Northern Italy that it
has long been discouraged by the Neapolitan government.]
Salts deposited by Water of Irrigation.
The attentive traveller in Egypt and Nubia cannot fail to notice many
localities, generally of small extent, where the soil is rendered infertile by
an excess of saline matter in its composition. In many cases, perhaps in all,
these barren spots lie rather above the level usually flooded by the
inundations of the Nile, and yet they exhibit traces of former cultivation.
Observations in India suggest a possible explanation of this fact. A saline
efflorescence called "Reh" and "Kuller" is gradually invading many of the
most fertile districts of Northern and Western India, and changing them into
sterile deserts. It consists principally of sulphate of soda (Glauber's salts),
with varying proportions of common salt. These salts (which in small
quantities are favorable to fertility of soil) are said to be the gradual result
of concentration by evaporation of river and canal waters, which contain
them in very minute quantities, and with which the lands are either irrigated
or occasionally overflowed. The river inundations in hot countries usually
take place but once in a year, and, though the banks remain submerged for
days or even weeks, the water at that period, being derived principally from
rains and snows, must be less highly charged with mineral matter than at
lower stages, and besides, it is always in motion. The water of irrigation, on
the other hand, is applied for many months in succession, it is drawn from
rivers and canals at the seasons when the proportion of salts is greatest, and
it either sinks into the superficial soil, carrying with it the saline substances
it holds in solution, or is evaporated from the surface, leaving them upon it.
Hence irrigation must impart to the soil more salts than natural inundation.
The sterilized grounds in Egypt and Nubia lying above the reach of the
floods, as I have said, we may suppose them to have been first cultivated in
has long been discouraged by the Neapolitan government.]
Salts deposited by Water of Irrigation.
The attentive traveller in Egypt and Nubia cannot fail to notice many
localities, generally of small extent, where the soil is rendered infertile by
an excess of saline matter in its composition. In many cases, perhaps in all,
these barren spots lie rather above the level usually flooded by the
inundations of the Nile, and yet they exhibit traces of former cultivation.
Observations in India suggest a possible explanation of this fact. A saline
efflorescence called "Reh" and "Kuller" is gradually invading many of the
most fertile districts of Northern and Western India, and changing them into
sterile deserts. It consists principally of sulphate of soda (Glauber's salts),
with varying proportions of common salt. These salts (which in small
quantities are favorable to fertility of soil) are said to be the gradual result
of concentration by evaporation of river and canal waters, which contain
them in very minute quantities, and with which the lands are either irrigated
or occasionally overflowed. The river inundations in hot countries usually
take place but once in a year, and, though the banks remain submerged for
days or even weeks, the water at that period, being derived principally from
rains and snows, must be less highly charged with mineral matter than at
lower stages, and besides, it is always in motion. The water of irrigation, on
the other hand, is applied for many months in succession, it is drawn from
rivers and canals at the seasons when the proportion of salts is greatest, and
it either sinks into the superficial soil, carrying with it the saline substances
it holds in solution, or is evaporated from the surface, leaving them upon it.
Hence irrigation must impart to the soil more salts than natural inundation.
The sterilized grounds in Egypt and Nubia lying above the reach of the
floods, as I have said, we may suppose them to have been first cultivated in
Page 587
that remote antiquity when the Nile valley received its earliest inhabitants,
and when its lower grounds were in the condition of morasses. They must
have been artificially irrigated from the beginning; they may have been
under cultivation many centuries before the soil at a lower level was
invaded by man, and hence it is natural that they should be more strongly
impregnated with saline matter than fields which are exposed every year,
for some weeks, to the action of running water so nearly pure that it would
be more likely to dissolve salts than to deposit them.
SUBTERRANEAN WATERS.
I have frequently alluded to a branch of physical geography, the importance
of which is but recently adequately recognized—the subterranean waters of
the earth considered as stationary reservoirs, as flowing currents, and as
filtrating fluids. The earth drinks in moisture by direct absorption from the
atmosphere, by the deposition of dew, by rain and snow, by percolation
from rivers and other superficial bodies of water, and sometimes by currents
flowing into caves or smaller visible apertures. [Footnote: The great
limestone plateau of the Karst in Carniola is completely honey-combed by
caves through which the drainage of that region is conducted. Rivers of
considerable volume pour into some of these caves and can be traced
underground to their exit. Thus the Recca has been satisfactorily identified
with a stream flowing through the cave of Trebich, and with the Timavo—
the Timavus of Virgil and the ancient geographers—which empties through
several mouths into the Adriatic between Trieste and Aquileia. The city of
Trieste is very insufficiently supplied with fresh water. It has been thought
practicable to supply this want by tunnelling through the wall of the plateau,
which rises abruptly in the rear of the town, until some subterranean stream
is encountered, the current of which can be conducted to the city. More
visionary projectors have gone further, and imagined that advantage might
and when its lower grounds were in the condition of morasses. They must
have been artificially irrigated from the beginning; they may have been
under cultivation many centuries before the soil at a lower level was
invaded by man, and hence it is natural that they should be more strongly
impregnated with saline matter than fields which are exposed every year,
for some weeks, to the action of running water so nearly pure that it would
be more likely to dissolve salts than to deposit them.
SUBTERRANEAN WATERS.
I have frequently alluded to a branch of physical geography, the importance
of which is but recently adequately recognized—the subterranean waters of
the earth considered as stationary reservoirs, as flowing currents, and as
filtrating fluids. The earth drinks in moisture by direct absorption from the
atmosphere, by the deposition of dew, by rain and snow, by percolation
from rivers and other superficial bodies of water, and sometimes by currents
flowing into caves or smaller visible apertures. [Footnote: The great
limestone plateau of the Karst in Carniola is completely honey-combed by
caves through which the drainage of that region is conducted. Rivers of
considerable volume pour into some of these caves and can be traced
underground to their exit. Thus the Recca has been satisfactorily identified
with a stream flowing through the cave of Trebich, and with the Timavo—
the Timavus of Virgil and the ancient geographers—which empties through
several mouths into the Adriatic between Trieste and Aquileia. The city of
Trieste is very insufficiently supplied with fresh water. It has been thought
practicable to supply this want by tunnelling through the wall of the plateau,
which rises abruptly in the rear of the town, until some subterranean stream
is encountered, the current of which can be conducted to the city. More
visionary projectors have gone further, and imagined that advantage might
Page 588
be taken of the natural tunnels under the Karst for the passage of roads,
railways, and even navigable canals. But however chimerical these latter
schemes may seem, there is every reason to believe that art might avail
itself of these galleries for improving the imperfect drainage of the
champaign country bounded by the Karst, and that stopping or opening the
natural channels might very much modify the hydrography of an extensive
region. See in Aus des Natur, xx., pp. 250-254, 263-266, two interesting
articles founded on the researches of Schmidt.
The cases are certainly not numerous where marine currents are known to
pour continuously into cavities beneath the surface of the earth, but there is
at least one well-authenticated instance of this sort—that of the mill-stream
at Argostoli in the island of Cephalonia. It had been long observed that the
sea-water flowed into several rifts and cavities in the limestone rocks of the
coast, but the phenomenon has excited little attention until very recently. In
1833, three of the entrances were closed, and a regular channel, sixteen feet
long and three feet wide, with a fall of three feet, was cut into the mouth of
a larger cavity. The sea-water flowed into this canal, and could be followed
eighteen or twenty feet beyond its inner terminus, when it disappeared in
holes and clefts in the rock.
In 1858 the canal had been enlarged to thewidth of five feet and a half,
and a depth of a foot. The water pours rapidly through the canal into an
irregular depression and forms a pool, the surface of which is three or four
feet below the adjacent soil, and about two and a half or three feet below
the level of the sea. From this pool it escapes through several holes and
clefts in the rock, and has not yet been found to emerge elsewhere.
There is a tide at Argostoli of about six inches in still weather, but it is
considerably higher with a south wind. I do not find it stated whether water
flows through the canal into the cavity at low tide, but it distinctly appears
railways, and even navigable canals. But however chimerical these latter
schemes may seem, there is every reason to believe that art might avail
itself of these galleries for improving the imperfect drainage of the
champaign country bounded by the Karst, and that stopping or opening the
natural channels might very much modify the hydrography of an extensive
region. See in Aus des Natur, xx., pp. 250-254, 263-266, two interesting
articles founded on the researches of Schmidt.
The cases are certainly not numerous where marine currents are known to
pour continuously into cavities beneath the surface of the earth, but there is
at least one well-authenticated instance of this sort—that of the mill-stream
at Argostoli in the island of Cephalonia. It had been long observed that the
sea-water flowed into several rifts and cavities in the limestone rocks of the
coast, but the phenomenon has excited little attention until very recently. In
1833, three of the entrances were closed, and a regular channel, sixteen feet
long and three feet wide, with a fall of three feet, was cut into the mouth of
a larger cavity. The sea-water flowed into this canal, and could be followed
eighteen or twenty feet beyond its inner terminus, when it disappeared in
holes and clefts in the rock.
In 1858 the canal had been enlarged to thewidth of five feet and a half,
and a depth of a foot. The water pours rapidly through the canal into an
irregular depression and forms a pool, the surface of which is three or four
feet below the adjacent soil, and about two and a half or three feet below
the level of the sea. From this pool it escapes through several holes and
clefts in the rock, and has not yet been found to emerge elsewhere.
There is a tide at Argostoli of about six inches in still weather, but it is
considerably higher with a south wind. I do not find it stated whether water
flows through the canal into the cavity at low tide, but it distinctly appears
Page 589
that there is no refluent current, as of course there could not be from a base
so much below the sea. Mousson found the delivery through the canal to be
at the rate of 24.88 cubic feet to the second; at what stage of the tide does
not appear. Other mills of the same sort have been erected, and there appear
to be several points on the coast where the sea flows into the land.
Various hypotheses have been suggested to explain this phenomenon,
some of which assume that the water descends to a great depth beneath the
crust of the earth; but the supposition of a difference of level in the surface
of the sea on the opposite sides of the island, which seems confirmed by
other circumstances, is the most obvious method of explaining these
singular facts. If we suppose the level of the water on one side of the island
to be raised by the action of currents three or four feet higher than on the
other, the existence of cavities and channels in the rock would easily
account for a subterranean current beneath the island, and the apertures of
escape might be so deep or so small as to elude observation. See Aus der
Natur, vol. xix., pp. 129 et seqq. I have lately been informed by a resident of
the Ionian Islands, who is familiar with the locality, that the sea flows
uninterruptedly into the sub-insular cavities, at all stages of the tide.] Some
of this humidity is exhaled again by the soil, some is taken up by organic
growths and by inorganic compounds, some poured out upon the surface by
springs and either immediately evaporated or carried down to larger streams
and to the sea, some flows by subterranean courses into the bed of fresh-
water rivers [Footnote: "The affluents received by the Seine below Rouen
are so inconsiderable, that the augmentation of the volume of that river
must be ascribed principally to springs rising in its bed. This is a point of
which engineers now take notice, and M. Belgrand, the able officer charged
with the improvement of the navigation of the Seine between Paris and
Rouen, has devoted much attention to it."—Babinet, Etudes et Lectures, iii.,
p. 185.
so much below the sea. Mousson found the delivery through the canal to be
at the rate of 24.88 cubic feet to the second; at what stage of the tide does
not appear. Other mills of the same sort have been erected, and there appear
to be several points on the coast where the sea flows into the land.
Various hypotheses have been suggested to explain this phenomenon,
some of which assume that the water descends to a great depth beneath the
crust of the earth; but the supposition of a difference of level in the surface
of the sea on the opposite sides of the island, which seems confirmed by
other circumstances, is the most obvious method of explaining these
singular facts. If we suppose the level of the water on one side of the island
to be raised by the action of currents three or four feet higher than on the
other, the existence of cavities and channels in the rock would easily
account for a subterranean current beneath the island, and the apertures of
escape might be so deep or so small as to elude observation. See Aus der
Natur, vol. xix., pp. 129 et seqq. I have lately been informed by a resident of
the Ionian Islands, who is familiar with the locality, that the sea flows
uninterruptedly into the sub-insular cavities, at all stages of the tide.] Some
of this humidity is exhaled again by the soil, some is taken up by organic
growths and by inorganic compounds, some poured out upon the surface by
springs and either immediately evaporated or carried down to larger streams
and to the sea, some flows by subterranean courses into the bed of fresh-
water rivers [Footnote: "The affluents received by the Seine below Rouen
are so inconsiderable, that the augmentation of the volume of that river
must be ascribed principally to springs rising in its bed. This is a point of
which engineers now take notice, and M. Belgrand, the able officer charged
with the improvement of the navigation of the Seine between Paris and
Rouen, has devoted much attention to it."—Babinet, Etudes et Lectures, iii.,
p. 185.
Page 590
On page 232 of the volume just quoted, the same author observes: "In the
lower part of its course, from the falls of the Oise, the Seine receives so few
important affluents, that evaporation alone would suffice to exhaust all the
water which passes under the bridges of Paris."
This supposes a much greater amount of evaporation than has been
usually computed, but I believe it is well settled that the Seine conveys to
the sea much more water than is discharged into it by all its superficial
branches. Babinet states the evaporation from the surface of water at Paris
to be twice as great as the precipitation.
Belgrand supposes that the floods of the Seine at Paris are not produced
by the superficial flow of the water of precipitation into its channel, but
from the augmented discharge of its remote mountain sources, when
swollen by the rains and melted snows which percolate through the
permeable strata in its upper course.—Annales des Ponts et Chaussees,
1851, vol. i.] or of the ocean, and some remains, though even here not in
forever motionless repose, to fill deep cavities and underground channels.
In every case the aqueous vapors of the air are the ultimate source of supply
and all these hidden stores are again returned to the atmosphere by
evaporation.
The proportion of the water of precipitation taken up by direct
evaporation from the surface of the ground seems to have been generally
exaggerated, sufficient allowance not being made for moisture carried
downwards or in a lateral direction by infiltration or by crevices in the
superior rocky or earthy strata. According to Wittwer, Mariotte found that
but one-sixth of the precipitation in the basin of the Seine was delivered
into that sea by the river, "so that five-sixths remained for evaporation and
consumption by the organic world." [Footnote: Physicalische Geographie,
lower part of its course, from the falls of the Oise, the Seine receives so few
important affluents, that evaporation alone would suffice to exhaust all the
water which passes under the bridges of Paris."
This supposes a much greater amount of evaporation than has been
usually computed, but I believe it is well settled that the Seine conveys to
the sea much more water than is discharged into it by all its superficial
branches. Babinet states the evaporation from the surface of water at Paris
to be twice as great as the precipitation.
Belgrand supposes that the floods of the Seine at Paris are not produced
by the superficial flow of the water of precipitation into its channel, but
from the augmented discharge of its remote mountain sources, when
swollen by the rains and melted snows which percolate through the
permeable strata in its upper course.—Annales des Ponts et Chaussees,
1851, vol. i.] or of the ocean, and some remains, though even here not in
forever motionless repose, to fill deep cavities and underground channels.
In every case the aqueous vapors of the air are the ultimate source of supply
and all these hidden stores are again returned to the atmosphere by
evaporation.
The proportion of the water of precipitation taken up by direct
evaporation from the surface of the ground seems to have been generally
exaggerated, sufficient allowance not being made for moisture carried
downwards or in a lateral direction by infiltration or by crevices in the
superior rocky or earthy strata. According to Wittwer, Mariotte found that
but one-sixth of the precipitation in the basin of the Seine was delivered
into that sea by the river, "so that five-sixths remained for evaporation and
consumption by the organic world." [Footnote: Physicalische Geographie,
Page 591
p. 286. It does not appear whether this inference is Mariotte's or Wittwer's. I
suppose it is a conclusion of the latter.
According to Valles, the Seine discharges into the sea thirty per cent. of
the precipitation in its valley, while the Po delivers into the Adriatic two-
thirds and perhaps even three-quarters of the total down-fall of its basin.
The differences between the tributaries of the Mississippi in this respect are
remarkable, the Missouri discharging only fifteen per cent., the Yazoo not
less than ninety. The explanation of these facts is found in the geographical
and geological character of the valleys of these rivers. The Missouri flows
with a rapid current through an irregular country, the Yazoo has a very slow
flow through a low, alluvial region which is kept constantly almost
saturated by infiltration.] Maury estimates the annual amount of
precipitation in the valley of the Mississippi at 620 cubic miles, the
discharge of that river into the sea at 107 cubic miles, and concludes that
"this would leave 513 cubic miles of water to be evaporated from this river-
basin annually." [Footnote: Physical Geography of the Sea. Tenth edition.
London, 1861, Section 274.] In these and other like computations, the water
carried down into the earth by capillary and larger conduits is wholly lost
sight of, and no thought is bestowed upon the supply for springs, for
common and artesian wells, and for underground rivers, like those in the
great caves of Kentucky, which may gush up in fresh-water currents at the
bottom of the Caribbean Sea, or rise to the light of day in the far-off
peninsula of Florida. [Footnote: In the low peninsula of Florida, rivers,
which must have their sources in mountains hundreds of miles distant, pour
forth from the earth with a volume sufficient to permit steamboats to ascend
to their basins of eruption. In January, 1857, a submarine fresh-water river
burst from the bottom of the sea not far from the southern extremity of the
peninsula, and for a whole month discharged a current not inferior in
volume to the river Mississippi, or eleven times the mean delivery of the
Po, and more than six times that of the Nile. We can explain this
suppose it is a conclusion of the latter.
According to Valles, the Seine discharges into the sea thirty per cent. of
the precipitation in its valley, while the Po delivers into the Adriatic two-
thirds and perhaps even three-quarters of the total down-fall of its basin.
The differences between the tributaries of the Mississippi in this respect are
remarkable, the Missouri discharging only fifteen per cent., the Yazoo not
less than ninety. The explanation of these facts is found in the geographical
and geological character of the valleys of these rivers. The Missouri flows
with a rapid current through an irregular country, the Yazoo has a very slow
flow through a low, alluvial region which is kept constantly almost
saturated by infiltration.] Maury estimates the annual amount of
precipitation in the valley of the Mississippi at 620 cubic miles, the
discharge of that river into the sea at 107 cubic miles, and concludes that
"this would leave 513 cubic miles of water to be evaporated from this river-
basin annually." [Footnote: Physical Geography of the Sea. Tenth edition.
London, 1861, Section 274.] In these and other like computations, the water
carried down into the earth by capillary and larger conduits is wholly lost
sight of, and no thought is bestowed upon the supply for springs, for
common and artesian wells, and for underground rivers, like those in the
great caves of Kentucky, which may gush up in fresh-water currents at the
bottom of the Caribbean Sea, or rise to the light of day in the far-off
peninsula of Florida. [Footnote: In the low peninsula of Florida, rivers,
which must have their sources in mountains hundreds of miles distant, pour
forth from the earth with a volume sufficient to permit steamboats to ascend
to their basins of eruption. In January, 1857, a submarine fresh-water river
burst from the bottom of the sea not far from the southern extremity of the
peninsula, and for a whole month discharged a current not inferior in
volume to the river Mississippi, or eleven times the mean delivery of the
Po, and more than six times that of the Nile. We can explain this
Page 592
phenomenon only by supposing that the bed of the sea was suddenly burst
up by the hydrostatic upward pressure of the water in a deep reservoir
communicating with some great subterranean river or receptacle in the
mountains of Georgia or of Cuba, or perhaps even in the valley of the
Mississippi.—Thomassy, Essai sur l'Hydrologie. Late southern journals
inform us that the creek under the Natural Bridge in Virginia has suddenly
disappeared, being swallowed up by newly formed fissures, of unknown
depth, in its channel. It does not appear that an outlet for the waters thus
absorbed has been discovered, and it is not improbable that they are filling
some underground cavity like that which supplied the submarine river just
mentioned.]
The progress of the emphatically modern science of geology has
corrected these erroneous views, because the observations on which it
depends have demonstrated not only the existence, but the movement, of
water in nearly all geological formations, have collected evidence of the
presence of large reservoirs at greater or less depths beneath surfaces of
almost every character, and have investigated the rationale of the attendant
phenomena. [Footnote: See especially Stoppani, Corso di Geologia, i., pp.
270 et seqq.] The distribution of these waters has been minutely studied
with reference to a great number of localities, and though the actual mode
and rate of their vertical and horizontal transmission is still involved in
much obscurity, the laws which determine their aggregation are so well
understood, that, when the geology of a given district is known, it is not
difficult to determine at what depth water will be reached by the borer, and
to what height it will rise. The same principles have been successfully
applied to the discovery of small subterranean collections or currents of
water, and some persons have acquired, by a moderate knowledge of the
superficial structure of the earth combined with long practice, a skill in the
selection of favorable places for digging wells which seems to common
observers little less than miraculous. The Abbe Paramelle—a French
up by the hydrostatic upward pressure of the water in a deep reservoir
communicating with some great subterranean river or receptacle in the
mountains of Georgia or of Cuba, or perhaps even in the valley of the
Mississippi.—Thomassy, Essai sur l'Hydrologie. Late southern journals
inform us that the creek under the Natural Bridge in Virginia has suddenly
disappeared, being swallowed up by newly formed fissures, of unknown
depth, in its channel. It does not appear that an outlet for the waters thus
absorbed has been discovered, and it is not improbable that they are filling
some underground cavity like that which supplied the submarine river just
mentioned.]
The progress of the emphatically modern science of geology has
corrected these erroneous views, because the observations on which it
depends have demonstrated not only the existence, but the movement, of
water in nearly all geological formations, have collected evidence of the
presence of large reservoirs at greater or less depths beneath surfaces of
almost every character, and have investigated the rationale of the attendant
phenomena. [Footnote: See especially Stoppani, Corso di Geologia, i., pp.
270 et seqq.] The distribution of these waters has been minutely studied
with reference to a great number of localities, and though the actual mode
and rate of their vertical and horizontal transmission is still involved in
much obscurity, the laws which determine their aggregation are so well
understood, that, when the geology of a given district is known, it is not
difficult to determine at what depth water will be reached by the borer, and
to what height it will rise. The same principles have been successfully
applied to the discovery of small subterranean collections or currents of
water, and some persons have acquired, by a moderate knowledge of the
superficial structure of the earth combined with long practice, a skill in the
selection of favorable places for digging wells which seems to common
observers little less than miraculous. The Abbe Paramelle—a French
Page 593
ecclesiastic who devoted himself for some years to this subject and was
extensively employed as a well-finder—states, in his work on Fountains,
that in the course of thirty-four years he had pointed out more than ten
thousand subterranean springs; and though his geological speculations were
often erroneous, high scientific authorities have testified to the great
practical value of his methods, and the general accuracy of his predictions.
[Footnote: Paramelle, Quellenkunde, mit einem Vorwort von B. Cotta.
1856.] Hydrographical researches have demonstrated the existence of
subterranean currents and reservoirs in many regions where superficial
geology had not indicated their probable presence. Thus, a much larger
proportion of the precipitation in the valley of the Tiber suddenly disappears
than can be accounted for by evaporation and visible flow into the channel
of the river. Castelli suspected that the excess was received by underground
caverns, and slowly conducted by percolation to the bed of the Tiber.
Lombardini—than whom there is no higher authority—concludes that the
quantity of water gradually discharged into the river by subterranean
conduits, is not less than three-quarters of the total delivery of its basin.
[Footnote: See Lombardini, Importanza degli studi sulla Statistica da Fiumi,
p. 27; also, same author, Sulle Inondazioni avvenute in Francia, etc., p. 29.]
What is true of the hydrology of the Tiber is doubtless more or less true of
that of other rivers, and the immense value of natural arrangements which
diminish the danger of sudden floods by retaining a large proportion of the
precipitation, and of an excessive reduction of river currents in the droughts
of summer, by slowly conducting into their beds water accumulated and
stored up in subterranean reservoirs in rainy seasons, is too obvious to
require to be dwelt upon. The readiness with which water not obstructed by
impermeable strata diffuses itself through the earth in all directions—and
consequently, the importance of keeping up the supply of subterranaean
reservoirs—find a familiar illustration in the effect of paving the ground
about the stems of vines and trees. The surface-earth around the trunk of a
extensively employed as a well-finder—states, in his work on Fountains,
that in the course of thirty-four years he had pointed out more than ten
thousand subterranean springs; and though his geological speculations were
often erroneous, high scientific authorities have testified to the great
practical value of his methods, and the general accuracy of his predictions.
[Footnote: Paramelle, Quellenkunde, mit einem Vorwort von B. Cotta.
1856.] Hydrographical researches have demonstrated the existence of
subterranean currents and reservoirs in many regions where superficial
geology had not indicated their probable presence. Thus, a much larger
proportion of the precipitation in the valley of the Tiber suddenly disappears
than can be accounted for by evaporation and visible flow into the channel
of the river. Castelli suspected that the excess was received by underground
caverns, and slowly conducted by percolation to the bed of the Tiber.
Lombardini—than whom there is no higher authority—concludes that the
quantity of water gradually discharged into the river by subterranean
conduits, is not less than three-quarters of the total delivery of its basin.
[Footnote: See Lombardini, Importanza degli studi sulla Statistica da Fiumi,
p. 27; also, same author, Sulle Inondazioni avvenute in Francia, etc., p. 29.]
What is true of the hydrology of the Tiber is doubtless more or less true of
that of other rivers, and the immense value of natural arrangements which
diminish the danger of sudden floods by retaining a large proportion of the
precipitation, and of an excessive reduction of river currents in the droughts
of summer, by slowly conducting into their beds water accumulated and
stored up in subterranean reservoirs in rainy seasons, is too obvious to
require to be dwelt upon. The readiness with which water not obstructed by
impermeable strata diffuses itself through the earth in all directions—and
consequently, the importance of keeping up the supply of subterranaean
reservoirs—find a familiar illustration in the effect of paving the ground
about the stems of vines and trees. The surface-earth around the trunk of a
Page 594
tree may be made almost impervious to water, by flagstones and cement, for
a distance as great as the spread of the roots; and yet the tree will not suffer
for want of moisture, except in droughts severe enough sensibly to affect
the supply in deep wells and springs. Both forest and fruit trees attain a
considerable age and size in cities where the streets and courts are closely
paved, and where even the lateral access of water to the roots is more or
less obstructed by deep cellars and foundation walls. The deep-lying veins
and sheets of water, supplied by infiltration from often comparatively
distant sources, send up moisture by capillary attraction, and the pavement
prevents the soil beneath it from losing its humidity by evaporation. Hence,
city-grown trees find moisture enough for their roots, and though plagued
with smoke and dust, often retain their freshness, while those planted in the
open fields, where sun and wind dry up the soil faster than the subterranean
fountains can water it, are withering from drought. [Footnote: The roots of
trees planted in towns do not depend exclusively on infiltration for their
supply of water, for they receive a certain amount of both moisture and air
through the interstices between the paving-stones; but where wide surfaces
of streets and courts are paved with air and water tight asphaltum, as in
Paris, trees suffer from the diminished supply of these necessary elements.]
Without the help of artificial conduit or of water-carrier, the Thames and the
Seine refresh the ornamental trees that shade the thoroughfares of London
and of Paris, and beneath the hot and reeking mould of Egypt, the Nile
sends currents to the extremest border of its valley. [Footnote: See the
interesting observations of Krieck on this subject, Schriften zur allgemeinen
Erdkunde, cap. iii., Section 6, and especially the passages in Ritter s
Erdkunde, vol. i., there referred to.
The tenacity with which the parched soil of Egypt retains the supply of
moisture it receives from the Nile is well illustrated by observations of
Girard cited by Lombardini from the Memoires de l'Academie des Sciences,
t. ii., 1817. Girard dug wells at distances of 3,200, 1,800, and 1,200 metres
a distance as great as the spread of the roots; and yet the tree will not suffer
for want of moisture, except in droughts severe enough sensibly to affect
the supply in deep wells and springs. Both forest and fruit trees attain a
considerable age and size in cities where the streets and courts are closely
paved, and where even the lateral access of water to the roots is more or
less obstructed by deep cellars and foundation walls. The deep-lying veins
and sheets of water, supplied by infiltration from often comparatively
distant sources, send up moisture by capillary attraction, and the pavement
prevents the soil beneath it from losing its humidity by evaporation. Hence,
city-grown trees find moisture enough for their roots, and though plagued
with smoke and dust, often retain their freshness, while those planted in the
open fields, where sun and wind dry up the soil faster than the subterranean
fountains can water it, are withering from drought. [Footnote: The roots of
trees planted in towns do not depend exclusively on infiltration for their
supply of water, for they receive a certain amount of both moisture and air
through the interstices between the paving-stones; but where wide surfaces
of streets and courts are paved with air and water tight asphaltum, as in
Paris, trees suffer from the diminished supply of these necessary elements.]
Without the help of artificial conduit or of water-carrier, the Thames and the
Seine refresh the ornamental trees that shade the thoroughfares of London
and of Paris, and beneath the hot and reeking mould of Egypt, the Nile
sends currents to the extremest border of its valley. [Footnote: See the
interesting observations of Krieck on this subject, Schriften zur allgemeinen
Erdkunde, cap. iii., Section 6, and especially the passages in Ritter s
Erdkunde, vol. i., there referred to.
The tenacity with which the parched soil of Egypt retains the supply of
moisture it receives from the Nile is well illustrated by observations of
Girard cited by Lombardini from the Memoires de l'Academie des Sciences,
t. ii., 1817. Girard dug wells at distances of 3,200, 1,800, and 1,200 metres
Page 595
from the Nile, and after three months of low water in the river, found water
in the most remote well, at 4m. 97, in the next at 4m. 23, and in that nearest
the bank at 3m. 44 above the surface of the Nile. The fact that the water was
highest in the most distant well appears to show that it was derived from the
inundation and not, by lateral infiltration, from the river. But water is found
beneath the sands at points far above and beyond the reach of the
inundations, and can be accounted for only by subterranean percolation
from the Nile. At high flood, the hydrostatic pressure on the banks,
combined with capillary attribution, sends water to great horizontal
distances through the loose soil; at low water the current is reversed, and
the moisture received from the river is partly returned, and may often be
seen oozing from the banks into the river.—Clot Bey, Apercu sur l'Egypte,
i., 128.
Laurent (Memoires sur le Sahara Oriental, pp. 8, 9), in speaking of a river
at El-Faid, "which, like all those of the desert, is, most of the time, without
water," observes, that many wells are dug in the bed of the river in the dry
season, and that the subterranean supply of water thus reached extends itself
laterally, at about the same level, at least a kilometre from the river, as water
is found by digging to the depth of twelve or fifteen metres at a village
situated at that distance from the bank.
Recent experiments, however, have shown that in the case of rivers
flowing through thickly peopled regions, and especially where the refuse
from industrial establishments is discharged into them, the finely
comminuted material received from sewers and factories sometimes clogs
up the interstices between the particles of sand and gravel which compose
the bed and banks, and the water is consequently confined to the channel
and no longer diffuses itself laterally through the adjacent soil. This
obstruction of course acts in both directions, according to circumstances. In
one case, it prevents the escape of river-water and tends to maintain a full
in the most remote well, at 4m. 97, in the next at 4m. 23, and in that nearest
the bank at 3m. 44 above the surface of the Nile. The fact that the water was
highest in the most distant well appears to show that it was derived from the
inundation and not, by lateral infiltration, from the river. But water is found
beneath the sands at points far above and beyond the reach of the
inundations, and can be accounted for only by subterranean percolation
from the Nile. At high flood, the hydrostatic pressure on the banks,
combined with capillary attribution, sends water to great horizontal
distances through the loose soil; at low water the current is reversed, and
the moisture received from the river is partly returned, and may often be
seen oozing from the banks into the river.—Clot Bey, Apercu sur l'Egypte,
i., 128.
Laurent (Memoires sur le Sahara Oriental, pp. 8, 9), in speaking of a river
at El-Faid, "which, like all those of the desert, is, most of the time, without
water," observes, that many wells are dug in the bed of the river in the dry
season, and that the subterranean supply of water thus reached extends itself
laterally, at about the same level, at least a kilometre from the river, as water
is found by digging to the depth of twelve or fifteen metres at a village
situated at that distance from the bank.
Recent experiments, however, have shown that in the case of rivers
flowing through thickly peopled regions, and especially where the refuse
from industrial establishments is discharged into them, the finely
comminuted material received from sewers and factories sometimes clogs
up the interstices between the particles of sand and gravel which compose
the bed and banks, and the water is consequently confined to the channel
and no longer diffuses itself laterally through the adjacent soil. This
obstruction of course acts in both directions, according to circumstances. In
one case, it prevents the escape of river-water and tends to maintain a full
Page 596
flow of the current; in another it intercepts the supply the river might
otherwise receive by infiltration from the land, and thus tends to reduce the
volume of the stream. In some instances pits have been sunk along the
banks of large rivers and the water which filters into them pumped up to
supply aqueducts. This method often succeeds, but where the bed of the
stream has been rendered impervious by the discharge of impurities into it,
it cannot be depended upon.
The tubular wells generally known as the American wells furnish another
proof of the free diffusion and circulation of water through the soil. I do not
know the date of the first employment of these tubes in the United States,
but as early as 1861, the Chevalier Calandra used wooden tubes for this
pose in Piedmont, with complete success. See the interesting pamphlet,
Sulla Estrazione delle Acque Sotterrance, by C. Calandra. Torino, 1867.
The most remarkable case of infiltration known to me by personal
observation is the occurrence of fresh water in the beach-sand on the
eastern side of the Gulf of Akaba, the eastern arm of the Red Sea. If you dig
a cavity in the beach near the sea-level, it soon fills with water so fresh as
not to be undrinkable, though the sea-water two or three yards from it
contains even more than the average quantity of salt. It cannot be
maintained that this is sea-water freshed by filtration through a few feet or
inches of sand, for salt-water cannot be deprived of its salt by that process.
It can only come from the highlands of Arabia, and it would seem that there
must exist some large reservoir in the interior to furnish a supply which, in
spite of evaporation, holds out for months after the last rains of winter, and
perhaps even through the year. I observed the fact in the month of June. See
Robinson, Biblical Researches, 1857, vol i., p. 167.
The precipitation in the mountains that border the Red Sea is not known
by pluviometric measurement, but the mass of debris brought down the
otherwise receive by infiltration from the land, and thus tends to reduce the
volume of the stream. In some instances pits have been sunk along the
banks of large rivers and the water which filters into them pumped up to
supply aqueducts. This method often succeeds, but where the bed of the
stream has been rendered impervious by the discharge of impurities into it,
it cannot be depended upon.
The tubular wells generally known as the American wells furnish another
proof of the free diffusion and circulation of water through the soil. I do not
know the date of the first employment of these tubes in the United States,
but as early as 1861, the Chevalier Calandra used wooden tubes for this
pose in Piedmont, with complete success. See the interesting pamphlet,
Sulla Estrazione delle Acque Sotterrance, by C. Calandra. Torino, 1867.
The most remarkable case of infiltration known to me by personal
observation is the occurrence of fresh water in the beach-sand on the
eastern side of the Gulf of Akaba, the eastern arm of the Red Sea. If you dig
a cavity in the beach near the sea-level, it soon fills with water so fresh as
not to be undrinkable, though the sea-water two or three yards from it
contains even more than the average quantity of salt. It cannot be
maintained that this is sea-water freshed by filtration through a few feet or
inches of sand, for salt-water cannot be deprived of its salt by that process.
It can only come from the highlands of Arabia, and it would seem that there
must exist some large reservoir in the interior to furnish a supply which, in
spite of evaporation, holds out for months after the last rains of winter, and
perhaps even through the year. I observed the fact in the month of June. See
Robinson, Biblical Researches, 1857, vol i., p. 167.
The precipitation in the mountains that border the Red Sea is not known
by pluviometric measurement, but the mass of debris brought down the
Page 597
ravines by the torrents proves that their volume must be large. The
proportion of surface covered by sand and absorbent earth, in Arabia
Petraea and the neighboring countries, is small, and the mountains drain
themselves rapidly into the wadies or ravines where the torrents are formed;
but the beds of earth and disintegrated rock at the bottom of the valleys are
of so loose and porous texture, that a great quantity of water is absorbed in
saturating them before a visible current is formed on their surface. In a
heavy thunder-storm, accompanied by a deluging rain, which I witnessed at
Mount Sinai in the month of May, a large stream of water poured, in an
almost continuous cascade, down the steep ravine north of the convent, by
which travellers sometimes descend from the plateau between the two
peaks, but after reaching the foot of the mountain, it flowed but a few yards
before it was swallowed up in the sands.
Fresh-water wells are not unfrequently found upon the borders of ocean
beaches. In the dry summer of 1870, drinkable water was procured in many
places on the coast of Liguria by digging to the depth of a yard in the
beach-sands. Tubular wells reach fresh water at twelve or fifteen feet below
the surface on the sandy plains of Cape Cod. In this latter case, the supply is
more probably derived directly from precipitation than from lateral
infiltration.]
Artesian Wells.
The existence of artesian wells depends upon that of subterranean
reservoirs and rivers, and the supply yielded by borings is regulated by the
abundance of such sources. The waters of the earth are, in many cases,
derived from superficial currents which are seen to pour into chasms
opened, as it were, expressly for their reception; and in others, where no
apertures in the crust of the earth have been detected, their existence is
proved by the fact that artesian wells sometimes bring up from great depths
proportion of surface covered by sand and absorbent earth, in Arabia
Petraea and the neighboring countries, is small, and the mountains drain
themselves rapidly into the wadies or ravines where the torrents are formed;
but the beds of earth and disintegrated rock at the bottom of the valleys are
of so loose and porous texture, that a great quantity of water is absorbed in
saturating them before a visible current is formed on their surface. In a
heavy thunder-storm, accompanied by a deluging rain, which I witnessed at
Mount Sinai in the month of May, a large stream of water poured, in an
almost continuous cascade, down the steep ravine north of the convent, by
which travellers sometimes descend from the plateau between the two
peaks, but after reaching the foot of the mountain, it flowed but a few yards
before it was swallowed up in the sands.
Fresh-water wells are not unfrequently found upon the borders of ocean
beaches. In the dry summer of 1870, drinkable water was procured in many
places on the coast of Liguria by digging to the depth of a yard in the
beach-sands. Tubular wells reach fresh water at twelve or fifteen feet below
the surface on the sandy plains of Cape Cod. In this latter case, the supply is
more probably derived directly from precipitation than from lateral
infiltration.]
Artesian Wells.
The existence of artesian wells depends upon that of subterranean
reservoirs and rivers, and the supply yielded by borings is regulated by the
abundance of such sources. The waters of the earth are, in many cases,
derived from superficial currents which are seen to pour into chasms
opened, as it were, expressly for their reception; and in others, where no
apertures in the crust of the earth have been detected, their existence is
proved by the fact that artesian wells sometimes bring up from great depths
Page 598
seeds, leaves, and even living fish, which must have been carried down
through channels large enough to admit a considerable stream. [Footnote:
Charles Martins, Le Sahara, in Revue des Deux Mondes, Sept. 1, 1864, p.
619; Stoppani, Corso di Geologia, i., 281; Desor, Die Sahara, Basel, 1871,
pp. 50, 51.] But in general, the sheet and currents of water reached by deep
boring appear to be primarily due to infiltration from highlands where the
water is first collected in superficial or subterranean reservoirs. By means
of channels conforming to the dip of the strata, these reservoirs
communicate with the lower basins, and exert upon them a fluid pressure
sufficient to raise a column to the surface, whenever an orifice is opened.
[Footnote: It is conceivable that in shallow subterranean basins
superincumbered mineral strata may rest upon the water and be partly
supported by it. In such case the weight of such strata would be an
additional, if not the sole, cause of the ascent of the water through the tubes
of artesian wells.
The ascent of petroleum in the artesian oil-wells in Pennsylvania, and, in
many cases, of salt-water in similar tubes, can hardly be ascribed to
hydrostatic pressure, and there is much difficulty in accounting for the rise
of water in artesian wells in many parts of the African desert on that
principle. Perhaps the elasticity of gases, which probably aids in forcing up
petroleum and saline waters, may be, not unfrequently, an agency in
causing the flow of water in common artesian borings. It is said that
artesian wells lately bored in Chicago, some to the depth of 1,600 feet, raise
water to the height of 100 feet above the surface. What is the source of the
pressure ] The water delivered by an artesian well is, therefore, often
derived from distant sources, and may be wholly unaffected by
geographical or meteorological changes in its immediate neighborhood,
while the same changes may quite dry up common wells and springs which
are fed only by the local infiltration of their own narrow basins.
through channels large enough to admit a considerable stream. [Footnote:
Charles Martins, Le Sahara, in Revue des Deux Mondes, Sept. 1, 1864, p.
619; Stoppani, Corso di Geologia, i., 281; Desor, Die Sahara, Basel, 1871,
pp. 50, 51.] But in general, the sheet and currents of water reached by deep
boring appear to be primarily due to infiltration from highlands where the
water is first collected in superficial or subterranean reservoirs. By means
of channels conforming to the dip of the strata, these reservoirs
communicate with the lower basins, and exert upon them a fluid pressure
sufficient to raise a column to the surface, whenever an orifice is opened.
[Footnote: It is conceivable that in shallow subterranean basins
superincumbered mineral strata may rest upon the water and be partly
supported by it. In such case the weight of such strata would be an
additional, if not the sole, cause of the ascent of the water through the tubes
of artesian wells.
The ascent of petroleum in the artesian oil-wells in Pennsylvania, and, in
many cases, of salt-water in similar tubes, can hardly be ascribed to
hydrostatic pressure, and there is much difficulty in accounting for the rise
of water in artesian wells in many parts of the African desert on that
principle. Perhaps the elasticity of gases, which probably aids in forcing up
petroleum and saline waters, may be, not unfrequently, an agency in
causing the flow of water in common artesian borings. It is said that
artesian wells lately bored in Chicago, some to the depth of 1,600 feet, raise
water to the height of 100 feet above the surface. What is the source of the
pressure ] The water delivered by an artesian well is, therefore, often
derived from distant sources, and may be wholly unaffected by
geographical or meteorological changes in its immediate neighborhood,
while the same changes may quite dry up common wells and springs which
are fed only by the local infiltration of their own narrow basins.
Page 599
In most cases, artesian wells have been bored for purely economical or
industrial purposes, such as to obtain good water for domestic use or for
driving light machinery, to reach saline or other mineral springs, and
recently, in America, to open fountains of petroleum or rock-oil. The
geographical and geological effects of such abstraction of fluids from the
bowels of the earth are too remote and uncertain to be here noticed;
[Footnote: Many more or less probable conjectures have been made on this
subject but thus far I am not aware that any of the apprehended results have
been actually shown to have happened. In an article in the Annales des
Ponts et Chaussees for July and August, 1839, p. 131, it was suggested that
the sinking of the piers of a bridge at Tours in France was occasioned by the
abstraction of water from the earth by artesian wells, and the consequent
withdrawal of the mechanical support it had previously given to the strata
containing it. A reply to this article will be found in Viollet, Theorie des
Puits Artesiens, p. 217.
In some instances the water has rushed up with a force which seemed to
threaten the inundation of the neighborhood, and even the washing away of
much soil; but in those cases the partial exhaustion of the supply, or the
relief of hydrostatic or elastic pressure, has generally produced a diminution
of theflow in a short time, and I do not know that any serious evil has
everbeen occasioned in this way.
In April, 1866, a case of this sort occurred in boring an artesian well near
the church of St. Agnes at Venice. When the drill reached the depth of 160
feet, a jet of mud and water was shot up to the height of 130 feet above the
surface, and continued to flow with gradually diminishing force for about
eight hours.] but artesian wells have lately been employed in Algeria for a
purpose which has even now a substantial, and may hereafter acquire a very
great geographical importance. It was observed by many earlier as well as
recent travellers in the East, among whom Shaw deserves special mention,
industrial purposes, such as to obtain good water for domestic use or for
driving light machinery, to reach saline or other mineral springs, and
recently, in America, to open fountains of petroleum or rock-oil. The
geographical and geological effects of such abstraction of fluids from the
bowels of the earth are too remote and uncertain to be here noticed;
[Footnote: Many more or less probable conjectures have been made on this
subject but thus far I am not aware that any of the apprehended results have
been actually shown to have happened. In an article in the Annales des
Ponts et Chaussees for July and August, 1839, p. 131, it was suggested that
the sinking of the piers of a bridge at Tours in France was occasioned by the
abstraction of water from the earth by artesian wells, and the consequent
withdrawal of the mechanical support it had previously given to the strata
containing it. A reply to this article will be found in Viollet, Theorie des
Puits Artesiens, p. 217.
In some instances the water has rushed up with a force which seemed to
threaten the inundation of the neighborhood, and even the washing away of
much soil; but in those cases the partial exhaustion of the supply, or the
relief of hydrostatic or elastic pressure, has generally produced a diminution
of theflow in a short time, and I do not know that any serious evil has
everbeen occasioned in this way.
In April, 1866, a case of this sort occurred in boring an artesian well near
the church of St. Agnes at Venice. When the drill reached the depth of 160
feet, a jet of mud and water was shot up to the height of 130 feet above the
surface, and continued to flow with gradually diminishing force for about
eight hours.] but artesian wells have lately been employed in Algeria for a
purpose which has even now a substantial, and may hereafter acquire a very
great geographical importance. It was observed by many earlier as well as
recent travellers in the East, among whom Shaw deserves special mention,
Page 600
that the Libyan desert, bordering upon the cultivated shores of the
Mediterranean, appeared in many places to rest upon a subterranean lake at
an accessible distance below the surface. The Moors are vaguely said to
bore artesian wells down to this reservoir, to obtain water for domestic use
and irrigation, and there is evidence that this art was practised in Northern
Africa in the Middle Ages. But it had been lost by the modern Moors, and
the universal astonishment and incredulity with which the native tribes
viewed the operations of the French engineers sent into the desert for that
purpose, are a sufficient proof that this mode of reaching the subterranean
waters was new to them. They were, however, aware of the existence of
water below the sands, and were dexterous in digging wells—square shafts
lined with a framework of palm-tree stems—to the level of the sheet. The
wells so constructed, though not technically artesian wells, answer the same
purpose; for the water rises to the surface and flows over it as from a spring.
[Footnote: See a very interesting account of these wells, and of the
workmen who clean them out when obstructed by sand brought up with the
water, in Laurent's memoir on the artesian wells recently bored by the
French Government in the Algerian desert. Mimoire sur le Sahara Oriental,
etc., pp. et seqq. Some of the men remained under water from two minutes
to two minutes and forty seconds. Several officers are quoted as having
observed immersions of three minutes' duration, and M. Berbrugger
witnessed ona of six minutes and five seconds and another of five minutes
and fifty-five seconds. The shortest of these periods is longer than the best
pearl-diver can remain below the surface of salt-water. The wells of the
Sahara are from twenty to eighty metres deep.-Desor, Die Sahara, Basel,
1871, p. 43.
The ancient Egyptians were acquainted with the art of boring artesian
wells. Ayme, a French engineer in the service of the Pacha of Egypt, found
several of these old wells, a few years ago, in the oases. They differed little
from modern artesian wells, but were provided with pear-shaped valves of
Mediterranean, appeared in many places to rest upon a subterranean lake at
an accessible distance below the surface. The Moors are vaguely said to
bore artesian wells down to this reservoir, to obtain water for domestic use
and irrigation, and there is evidence that this art was practised in Northern
Africa in the Middle Ages. But it had been lost by the modern Moors, and
the universal astonishment and incredulity with which the native tribes
viewed the operations of the French engineers sent into the desert for that
purpose, are a sufficient proof that this mode of reaching the subterranean
waters was new to them. They were, however, aware of the existence of
water below the sands, and were dexterous in digging wells—square shafts
lined with a framework of palm-tree stems—to the level of the sheet. The
wells so constructed, though not technically artesian wells, answer the same
purpose; for the water rises to the surface and flows over it as from a spring.
[Footnote: See a very interesting account of these wells, and of the
workmen who clean them out when obstructed by sand brought up with the
water, in Laurent's memoir on the artesian wells recently bored by the
French Government in the Algerian desert. Mimoire sur le Sahara Oriental,
etc., pp. et seqq. Some of the men remained under water from two minutes
to two minutes and forty seconds. Several officers are quoted as having
observed immersions of three minutes' duration, and M. Berbrugger
witnessed ona of six minutes and five seconds and another of five minutes
and fifty-five seconds. The shortest of these periods is longer than the best
pearl-diver can remain below the surface of salt-water. The wells of the
Sahara are from twenty to eighty metres deep.-Desor, Die Sahara, Basel,
1871, p. 43.
The ancient Egyptians were acquainted with the art of boring artesian
wells. Ayme, a French engineer in the service of the Pacha of Egypt, found
several of these old wells, a few years ago, in the oases. They differed little
from modern artesian wells, but were provided with pear-shaped valves of
Page 601
stone for closing them when water was not needed. When freed from the
sand and rubbish with which they were choked, they flowed freely and
threw up fish large enough for the table. The fish were not blind, as cave-
fish often are, but were provided with eyes, and belonged to species
common in the Nile. The sand, too, brought up with them resembled that of
the bed of that river. Hence it is probable that they were carried to the oases
by subterranean channels from the Nile.—Desor, Die Sahara, Basel, 1871,
p. 28; Stoppani, Corso di Geologia, i., p. 281. Barth speaks of common
wells in Northern Africa from 200 to 360 feet deep.—Reisen in Africa, ii.,
p. 180.
It is certain that artesian wells have been common in China from a very
remote antiquity, and the simple method used by the Chinese—where the
drill is raised and let fall by a rope, instead of a rigid rod—has lately been
employed in Europe with advantage. Some of the Chinese wells are said to
be 3,000 feet deep; that of Neusalzwerk in Silesia is 2,300. A well was
bored at St. Louis, in Missouri, a few years ago, to supply a sugar refinery,
to the depth of 2,199 feet. This was executed by a private firm in three
years, at the expense of only $10,000. Four years since the boring was
recommenced in this well and reached a depth of 3,150 feet, but without a
satisfactory result. Another artesian well was sunk at Columbus, in Ohio, to
the depth of 2,500 feet, but without obtaining the desired supply of water.
Perhaps, however, the artesian well of the greatest depth ever executed until
very recently, is that bored within the last six or seven years, for the use of
an Insane Asylum near St. Louis. This well descends to the depth of three
thousand eight hundred and forty-three feet, but the water which it furnishes
is small in quantity and of a quality that cannot be used for ordinary
domestic purposes. The bore has a diameter of six inches to the depth of
425 feet, and after that it is reduced to four inches. For about three thousand
feet the strata penetrated were of carboniferous and magnesian limestone
alternating with sandstone. The remainder of the well passes through
sand and rubbish with which they were choked, they flowed freely and
threw up fish large enough for the table. The fish were not blind, as cave-
fish often are, but were provided with eyes, and belonged to species
common in the Nile. The sand, too, brought up with them resembled that of
the bed of that river. Hence it is probable that they were carried to the oases
by subterranean channels from the Nile.—Desor, Die Sahara, Basel, 1871,
p. 28; Stoppani, Corso di Geologia, i., p. 281. Barth speaks of common
wells in Northern Africa from 200 to 360 feet deep.—Reisen in Africa, ii.,
p. 180.
It is certain that artesian wells have been common in China from a very
remote antiquity, and the simple method used by the Chinese—where the
drill is raised and let fall by a rope, instead of a rigid rod—has lately been
employed in Europe with advantage. Some of the Chinese wells are said to
be 3,000 feet deep; that of Neusalzwerk in Silesia is 2,300. A well was
bored at St. Louis, in Missouri, a few years ago, to supply a sugar refinery,
to the depth of 2,199 feet. This was executed by a private firm in three
years, at the expense of only $10,000. Four years since the boring was
recommenced in this well and reached a depth of 3,150 feet, but without a
satisfactory result. Another artesian well was sunk at Columbus, in Ohio, to
the depth of 2,500 feet, but without obtaining the desired supply of water.
Perhaps, however, the artesian well of the greatest depth ever executed until
very recently, is that bored within the last six or seven years, for the use of
an Insane Asylum near St. Louis. This well descends to the depth of three
thousand eight hundred and forty-three feet, but the water which it furnishes
is small in quantity and of a quality that cannot be used for ordinary
domestic purposes. The bore has a diameter of six inches to the depth of
425 feet, and after that it is reduced to four inches. For about three thousand
feet the strata penetrated were of carboniferous and magnesian limestone
alternating with sandstone. The remainder of the well passes through
Page 602
igneous rock. At St. Louis the Missouri and Mississippi rivers are not more
than twenty miles distant from each other, and it is worthy of note that the
waters of neither of those two rivers appear to have opened for themselves a
considerable subterranean passage through the rocky strata of the peninsula
which separates them.
When in boring an artesian well water is not reached at a moderate depth,
it is not always certain that it will be found by driving the drill still lower. In
certain formations, water diminshes as we descend, and it seems probable
that, except in case of caverns and deep fissures, the weight of the
superincumbent mineral strata so compresses the underlying ones, at no
very great distance below the surface, as to render them impermeable to
water and consequently altogether dry. See London Quarterly Journal of
Science, No. xvii., Jan., 1868, p. 18, 19.
In the silver mines of Nevada water is scarcely found at depths below
1,000 feet, and at 1,200 feet from the surface the earth is quite dry.—
American Annual of Scientific Discovery for 1870, p. 75.
Similar facts are observed in Australia. The Pleasant Creek News writes:
"A singular and unaccountable feature in connection with our deep quartz
mines is being developed daily, which must surprise those well experienced
in mining matters. It is the decrease of water as the greater depths are
reached. In the Magdala shaft at 950 ft. the water has decreased to a
MINIMUM; in the Crown Cross Reef Company's shaft, at 800 ft.,
notwithstanding the two reefs recently struck, no extra water has been met
with; and in the long drive of the Extended Cross Reef Company, at a depth
of over 800 ft., the water is lighter than it was nearer the surface."
Boring has been carried to a great depth at Sperenberg near Berlin,
where, in 1871, the drill had descended 5,500 feet below the surface,
passing through a stratum of salt for the last 3,200 feet; but the drilling was
than twenty miles distant from each other, and it is worthy of note that the
waters of neither of those two rivers appear to have opened for themselves a
considerable subterranean passage through the rocky strata of the peninsula
which separates them.
When in boring an artesian well water is not reached at a moderate depth,
it is not always certain that it will be found by driving the drill still lower. In
certain formations, water diminshes as we descend, and it seems probable
that, except in case of caverns and deep fissures, the weight of the
superincumbent mineral strata so compresses the underlying ones, at no
very great distance below the surface, as to render them impermeable to
water and consequently altogether dry. See London Quarterly Journal of
Science, No. xvii., Jan., 1868, p. 18, 19.
In the silver mines of Nevada water is scarcely found at depths below
1,000 feet, and at 1,200 feet from the surface the earth is quite dry.—
American Annual of Scientific Discovery for 1870, p. 75.
Similar facts are observed in Australia. The Pleasant Creek News writes:
"A singular and unaccountable feature in connection with our deep quartz
mines is being developed daily, which must surprise those well experienced
in mining matters. It is the decrease of water as the greater depths are
reached. In the Magdala shaft at 950 ft. the water has decreased to a
MINIMUM; in the Crown Cross Reef Company's shaft, at 800 ft.,
notwithstanding the two reefs recently struck, no extra water has been met
with; and in the long drive of the Extended Cross Reef Company, at a depth
of over 800 ft., the water is lighter than it was nearer the surface."
Boring has been carried to a great depth at Sperenberg near Berlin,
where, in 1871, the drill had descended 5,500 feet below the surface,
passing through a stratum of salt for the last 3,200 feet; but the drilling was
Page 603
still in progress, the whole thickness of the salt-bed not having been
penetrated.—Aus der Natur, vol. 55, p. 208.
The facts that there are mines extending two miles under the bed of the
sea, which are not particularly subject to inconvenience from water, that
little water was encountered in the Mt. Cenis tunnel, 3500 feet below the
surface, and that at Scarpa, not far from Tivoli, there is an ancient well 1700
feet deep with but eighteen feet of water, may also be cited as proofs that
water is not universally diffused at great distances beneath the surface.]
These wells, however, are too few and too scanty in supply to serve any
other purposes than the domestic wells of other countries, and it is but
recently that the transformation of desert into cultivable land by this means
has been seriously attempted. The French Government has bored a large
number of artesian wells in the Algerian desert within a few years, and the
native sheikhs are beginning to avail themselves of the process. Every well
becomes the nucleus of a settlement proportioned to the supply of water,
and before the end of the year 1860, several nomade tribes had abandoned
their wandering life, established themselves around the wells, and planted
more than 30,000 palm trees, besides other perennial vegetables. [Footnote:
"In the anticipation of our success at Oum-Thiour, everything had been
prepared to take advantage of this new source of wealth without a moment's
delay. A division of the tribe of the Selmia, and their sheikh, Aissa ben Sha,
laid the foundation of a village as soon as the water flowed, and planted
twelve hundred date-palms, renouncing their wandering life to attach
themselves to the soil. In this arid spot, life had taken the place of solitude,
and presented itself, with its smiling images, to the astonished traveller.
Young girls were drawing water at the fountain; the flocks, the great
dromedaries with their slow pace, the horses led by the halter, were moving
to the watering trough; the hounds and the falcons enlivened the group of
party-colored tents, and living voices and animated movement had
penetrated.—Aus der Natur, vol. 55, p. 208.
The facts that there are mines extending two miles under the bed of the
sea, which are not particularly subject to inconvenience from water, that
little water was encountered in the Mt. Cenis tunnel, 3500 feet below the
surface, and that at Scarpa, not far from Tivoli, there is an ancient well 1700
feet deep with but eighteen feet of water, may also be cited as proofs that
water is not universally diffused at great distances beneath the surface.]
These wells, however, are too few and too scanty in supply to serve any
other purposes than the domestic wells of other countries, and it is but
recently that the transformation of desert into cultivable land by this means
has been seriously attempted. The French Government has bored a large
number of artesian wells in the Algerian desert within a few years, and the
native sheikhs are beginning to avail themselves of the process. Every well
becomes the nucleus of a settlement proportioned to the supply of water,
and before the end of the year 1860, several nomade tribes had abandoned
their wandering life, established themselves around the wells, and planted
more than 30,000 palm trees, besides other perennial vegetables. [Footnote:
"In the anticipation of our success at Oum-Thiour, everything had been
prepared to take advantage of this new source of wealth without a moment's
delay. A division of the tribe of the Selmia, and their sheikh, Aissa ben Sha,
laid the foundation of a village as soon as the water flowed, and planted
twelve hundred date-palms, renouncing their wandering life to attach
themselves to the soil. In this arid spot, life had taken the place of solitude,
and presented itself, with its smiling images, to the astonished traveller.
Young girls were drawing water at the fountain; the flocks, the great
dromedaries with their slow pace, the horses led by the halter, were moving
to the watering trough; the hounds and the falcons enlivened the group of
party-colored tents, and living voices and animated movement had
Page 604
succeeded to silence and desolation."—Laurent, Memoires sur le Sahara, p.
85.
Between 1856 and 1864 the French engineers had bored 83 wells in the
Hodna and the Sahara of the Province of Constantine, yielding, all together,
9,000 gallons a minute, and irrigating more than 125,000 date-palms.
Reclus, La Terre, i., p. 110.] The water is found at a small depth, generally
from 100 to 200 feet, and though containing too large a proportion of
mineral matter to be acceptable to a European palate, it answers well for
irrigation, and does not prove unwholesome to the natives.
The most obvious use of artesian wells in the desert at present is that of
creating stations for the establishment of military posts and halting-places
for the desert traveller; but if the supply of water shall prove adequate for
the indefinite extension of the system, it is probably destined to produce a
greater geographical transformation than has ever been effected by any
scheme of human improvement.
The most striking contrast of landscape scenery that nature brings near
together in time or place, is that between the greenery of the tropics, or of a
northern summer, and the snowy pall of leafless winter. Next to this in
startling novelty of effect, we must rank the sudden transition from the
shady and verdant oasis of the desert to the bare and burning party-colored
ocean of sand and rock which surrounds it. [Footnote: The variety of hues
and tones in the local color of the desert is, I think, one of the phenomena
which most surprise and interest a stranger to those regions. In England and
the United States, rock is so generally covered with moss or earth, and earth
with vegetation, that untravelled Englishmen and Americans are not very
familiar with naked rock as a conspicuous element of landscape. Hence, in
their conception of a bare cliff or precipice, they hardly ascribe definite
color to it, but depict it to their imagination as wearing a neutral tint not
85.
Between 1856 and 1864 the French engineers had bored 83 wells in the
Hodna and the Sahara of the Province of Constantine, yielding, all together,
9,000 gallons a minute, and irrigating more than 125,000 date-palms.
Reclus, La Terre, i., p. 110.] The water is found at a small depth, generally
from 100 to 200 feet, and though containing too large a proportion of
mineral matter to be acceptable to a European palate, it answers well for
irrigation, and does not prove unwholesome to the natives.
The most obvious use of artesian wells in the desert at present is that of
creating stations for the establishment of military posts and halting-places
for the desert traveller; but if the supply of water shall prove adequate for
the indefinite extension of the system, it is probably destined to produce a
greater geographical transformation than has ever been effected by any
scheme of human improvement.
The most striking contrast of landscape scenery that nature brings near
together in time or place, is that between the greenery of the tropics, or of a
northern summer, and the snowy pall of leafless winter. Next to this in
startling novelty of effect, we must rank the sudden transition from the
shady and verdant oasis of the desert to the bare and burning party-colored
ocean of sand and rock which surrounds it. [Footnote: The variety of hues
and tones in the local color of the desert is, I think, one of the phenomena
which most surprise and interest a stranger to those regions. In England and
the United States, rock is so generally covered with moss or earth, and earth
with vegetation, that untravelled Englishmen and Americans are not very
familiar with naked rock as a conspicuous element of landscape. Hence, in
their conception of a bare cliff or precipice, they hardly ascribe definite
color to it, but depict it to their imagination as wearing a neutral tint not
Page 605
assimilable to any of the hues with which nature tinges her atmospheric or
paints her organic creations. There are certainly extensive desert ranges,
chiefly limestone formations, where the surface is either white, or has
weathered down to a dull uniformity of tone which can hardly be called
color at all; and there are sand plains and drifting hills of wearisome
monotony of tint. But the chemistry of the air, though it may tame the glitter
of the limestone to a dusky gray, brings out the green and brown and purple
of the igneous rocks, and the white and red and blue and violet and yellow
of the sandstone. Many a cliff in Arabia Petraea is as manifold in color as
the rainbow, and the veins are so variable in thickness and inclination, so
contorted and involved in arrangement, as to bewilder the eye of the
spectator like a disk of party-colored glass in rapid evolution.
In the narrower wadies the mirage is not common; but on broad
expanses, as at many points between Cairo and Suez, and in Wadi el Araba,
it mocks you with lakes and land-locked bays, studded with inlands and
fringed with trees, all painted with an illusory truth of representation
absolutely indistinguishable from the reality. The checkered earth, too, is
canopied with a heaven as variegated as itself. You see, high up in the sky,
rosy clouds at noonday, colored probably by reflection from the ruddy
mountains, while near the horizon float cumuli of a transparent, ethereal
blue, seemingly balled up out of the clear cerulean substance of the
firmament, and detached from the heavenly vault, not by color or
consistence, but solely by the light and shade of their salient and retreating
outlines.] The most sanguine believer in indefinite human progress hardly
expects that man's cunning will accomplish the universal fulfilment of the
prophecy, "the desert shall blossom as the rose," in its literal sense; but
sober geographers have thought the future conversion of the sand plains of
Northern Africa into fruitful gardens, by means of artesian wells, not an
improbable expectation. They have gone farther, and argued that, if the soil
were covered with fields and forests, vegetation would call down moisture
paints her organic creations. There are certainly extensive desert ranges,
chiefly limestone formations, where the surface is either white, or has
weathered down to a dull uniformity of tone which can hardly be called
color at all; and there are sand plains and drifting hills of wearisome
monotony of tint. But the chemistry of the air, though it may tame the glitter
of the limestone to a dusky gray, brings out the green and brown and purple
of the igneous rocks, and the white and red and blue and violet and yellow
of the sandstone. Many a cliff in Arabia Petraea is as manifold in color as
the rainbow, and the veins are so variable in thickness and inclination, so
contorted and involved in arrangement, as to bewilder the eye of the
spectator like a disk of party-colored glass in rapid evolution.
In the narrower wadies the mirage is not common; but on broad
expanses, as at many points between Cairo and Suez, and in Wadi el Araba,
it mocks you with lakes and land-locked bays, studded with inlands and
fringed with trees, all painted with an illusory truth of representation
absolutely indistinguishable from the reality. The checkered earth, too, is
canopied with a heaven as variegated as itself. You see, high up in the sky,
rosy clouds at noonday, colored probably by reflection from the ruddy
mountains, while near the horizon float cumuli of a transparent, ethereal
blue, seemingly balled up out of the clear cerulean substance of the
firmament, and detached from the heavenly vault, not by color or
consistence, but solely by the light and shade of their salient and retreating
outlines.] The most sanguine believer in indefinite human progress hardly
expects that man's cunning will accomplish the universal fulfilment of the
prophecy, "the desert shall blossom as the rose," in its literal sense; but
sober geographers have thought the future conversion of the sand plains of
Northern Africa into fruitful gardens, by means of artesian wells, not an
improbable expectation. They have gone farther, and argued that, if the soil
were covered with fields and forests, vegetation would call down moisture
Page 606
from the Libyan sky, and that the showers which are now wasted on the sea,
or so often deluge Southern Europe with destructive inundation, would in
part be condensed over the arid wastes of Africa, and thus, without further
aid from man, bestow abundance on regions which nature seems to have
condemned to perpetual desolation.
An equally bold speculation, founded on the well-known fact that the
temperature of the earth and of its internal waters increases as we descend
beneath the surface, has suggested that artesian wells might supply heat for
industrial and domestic purposes, for hot-house cultivation, and even for the
local amelioration of climate. The success with which Count Lardarel has
employed natural hot springs for the evaporation of water charged with
boracic acid, and other fortunate applications of the heat of thermal sources,
lend some countenance to the latter project; but both must, for the present,
be ranked among the vague possibilities of science, not regarded as
probable future triumphs of man over nature.
Artificial Springs
A more plausible and inviting scheme is that of the creation of perennial
springs by husbanding rain and snow water, storing it up in artificial
reservoirs of earth, and filtering it through purifying strata, in analogy with
the operations of nature. The sagacious Palissy—starting from the theory
that all springs are primarily derived from precipitation, and reasoning
justly on the accumulation and movement of water in the earth—proposed
to reduce theory to practice, and to imitate the natural processes by which
rain is absorbed by the earth and given out again in running fountains.
"When I had long and diligently considered the cause of the springing of
natural fountains and the places where they be wont to issue," says he, "I
did plainly perceive, at last, that they do proceed and are engendered of
nought but the rains. And it is this, look you, which hath moved me to
or so often deluge Southern Europe with destructive inundation, would in
part be condensed over the arid wastes of Africa, and thus, without further
aid from man, bestow abundance on regions which nature seems to have
condemned to perpetual desolation.
An equally bold speculation, founded on the well-known fact that the
temperature of the earth and of its internal waters increases as we descend
beneath the surface, has suggested that artesian wells might supply heat for
industrial and domestic purposes, for hot-house cultivation, and even for the
local amelioration of climate. The success with which Count Lardarel has
employed natural hot springs for the evaporation of water charged with
boracic acid, and other fortunate applications of the heat of thermal sources,
lend some countenance to the latter project; but both must, for the present,
be ranked among the vague possibilities of science, not regarded as
probable future triumphs of man over nature.
Artificial Springs
A more plausible and inviting scheme is that of the creation of perennial
springs by husbanding rain and snow water, storing it up in artificial
reservoirs of earth, and filtering it through purifying strata, in analogy with
the operations of nature. The sagacious Palissy—starting from the theory
that all springs are primarily derived from precipitation, and reasoning
justly on the accumulation and movement of water in the earth—proposed
to reduce theory to practice, and to imitate the natural processes by which
rain is absorbed by the earth and given out again in running fountains.
"When I had long and diligently considered the cause of the springing of
natural fountains and the places where they be wont to issue," says he, "I
did plainly perceive, at last, that they do proceed and are engendered of
nought but the rains. And it is this, look you, which hath moved me to
Page 607
enterprise the gathering together of rain-water after the manner of nature,
and the most closely according to her fashion that I am able; and I am well
assured that by following the formulary of the Supreme Contriver of
fountains, I can make springs, the water whereof shall be as good and pure
and clear as of such which be natural." [Footnote: Oeuvres de Palissy, Des
Eaux et Fontaines, p. 157.] Palissy discusses the subject of the origin of
springs at length and with much ability, dwelling specially on infiltration,
and, among other things, thus explains the frequency of springs in
mountainous regions: "Having well considered the which, thou mayest
plainly see the reason why there be more springs and rivulets proceeding
from the mountains than from the rest of the earth; which is for no other
cause but that the rocks and mountains do retain the water of the rains like
vessels of brass. And the said waters falling upon the said mountains
descend continually through the earth, and through crevices, and stop not
till they find some place that is bottomed with stone or close and thick
rocks; and they rest upon such bottom until they find some channel or other
manner of issue, and then they flow out in springs or brooks or rivers,
according to the greatness of the reservoirs and of the outlets thereof."
[Footnote: Id., p. 166. Palissy's method has recently been tried with good
success in various parts of France.]
After a full exposition of his theory, Palissy proceeds to describe his
method of creating springs, which is substantially the same as that lately
proposed by Babinet in the following terms: "Choose a piece of ground
containing four or five acres, with a sandy soil, and with a gentle slope to
determine the flow of the water. Along its upper line, dig a trench five or six
feet deep and six feet wide. Level the bottom of the trench, and make it
impermeable by paving, by macadamizing, by bitumen, or, more simply
and cheaply, by a layer of clay. By the side of this trench dig another, and
throw the earth from it into the first, and so on until you have rendered the
subsoil of the whole parcel impermeable to rain-water. Build a wall along
and the most closely according to her fashion that I am able; and I am well
assured that by following the formulary of the Supreme Contriver of
fountains, I can make springs, the water whereof shall be as good and pure
and clear as of such which be natural." [Footnote: Oeuvres de Palissy, Des
Eaux et Fontaines, p. 157.] Palissy discusses the subject of the origin of
springs at length and with much ability, dwelling specially on infiltration,
and, among other things, thus explains the frequency of springs in
mountainous regions: "Having well considered the which, thou mayest
plainly see the reason why there be more springs and rivulets proceeding
from the mountains than from the rest of the earth; which is for no other
cause but that the rocks and mountains do retain the water of the rains like
vessels of brass. And the said waters falling upon the said mountains
descend continually through the earth, and through crevices, and stop not
till they find some place that is bottomed with stone or close and thick
rocks; and they rest upon such bottom until they find some channel or other
manner of issue, and then they flow out in springs or brooks or rivers,
according to the greatness of the reservoirs and of the outlets thereof."
[Footnote: Id., p. 166. Palissy's method has recently been tried with good
success in various parts of France.]
After a full exposition of his theory, Palissy proceeds to describe his
method of creating springs, which is substantially the same as that lately
proposed by Babinet in the following terms: "Choose a piece of ground
containing four or five acres, with a sandy soil, and with a gentle slope to
determine the flow of the water. Along its upper line, dig a trench five or six
feet deep and six feet wide. Level the bottom of the trench, and make it
impermeable by paving, by macadamizing, by bitumen, or, more simply
and cheaply, by a layer of clay. By the side of this trench dig another, and
throw the earth from it into the first, and so on until you have rendered the
subsoil of the whole parcel impermeable to rain-water. Build a wall along
Page 608
the lower line with an aperture in the middle for the water, and plant fruit or
other low trees upon the whole, to shade the ground and check the currents
of air which promote evaporation. This will infallibly give you a good
spring which will flow without intermission, and supply the wants of a
whole hamlet or a large chateau." [Footnote: Babinet, Etudes et Lectures sur
les Sciences d'Observation, ii., p. 225. Our author precedes his account of
his method with a complaint which most men who indulge in thinking have
occasion to repeat many times in the course of their lives. "I will explain to
my readers the construction of artificial fountains according to the plan of
the famous Bernard de Palissy, who, a hundred and fifty [three hundred]
years ago, came and took away from me, a humble academician of the
nineteenth century, this discovery which I had taken a great deal of pains to
make. It is enough to discourage all invention when one finds plagiarists in
the past as well as in the future!" (P. 224.)] Babinet states that the whole
amount of precipitation on a reservoir of the proposed area, in the climate
of Paris, would be about 13,000 cubic yards, not above one half of which,
he thinks, would be lost, and, of course, the other half would remain
available to supply the spring. I much doubt whether this expectation would
be realized in practice, in its whole extent; for if Babinet is right in
supposing that the summer rain is wholly evaporated, the winter rains,
being much less in quantity, would hardly suffice to keep the earth saturated
and give off so large a surplus. The method of Palissy, though, as I have
said, similar in principle to that of Babinet, would be cheaper of execution,
and, at the same time, more efficient. He proposes the construction of
relatively small filtering receptacles, into which he would conduct the rain
falling upon a large area of rocky hillside, or other sloping ground not
readily absorbing water. This process would, in all probability, be a very
successful, as well as an inexpensive, mode of economizing atmospheric
precipitation, and compelling the rain and snow to form perennial fountains
at will.
other low trees upon the whole, to shade the ground and check the currents
of air which promote evaporation. This will infallibly give you a good
spring which will flow without intermission, and supply the wants of a
whole hamlet or a large chateau." [Footnote: Babinet, Etudes et Lectures sur
les Sciences d'Observation, ii., p. 225. Our author precedes his account of
his method with a complaint which most men who indulge in thinking have
occasion to repeat many times in the course of their lives. "I will explain to
my readers the construction of artificial fountains according to the plan of
the famous Bernard de Palissy, who, a hundred and fifty [three hundred]
years ago, came and took away from me, a humble academician of the
nineteenth century, this discovery which I had taken a great deal of pains to
make. It is enough to discourage all invention when one finds plagiarists in
the past as well as in the future!" (P. 224.)] Babinet states that the whole
amount of precipitation on a reservoir of the proposed area, in the climate
of Paris, would be about 13,000 cubic yards, not above one half of which,
he thinks, would be lost, and, of course, the other half would remain
available to supply the spring. I much doubt whether this expectation would
be realized in practice, in its whole extent; for if Babinet is right in
supposing that the summer rain is wholly evaporated, the winter rains,
being much less in quantity, would hardly suffice to keep the earth saturated
and give off so large a surplus. The method of Palissy, though, as I have
said, similar in principle to that of Babinet, would be cheaper of execution,
and, at the same time, more efficient. He proposes the construction of
relatively small filtering receptacles, into which he would conduct the rain
falling upon a large area of rocky hillside, or other sloping ground not
readily absorbing water. This process would, in all probability, be a very
successful, as well as an inexpensive, mode of economizing atmospheric
precipitation, and compelling the rain and snow to form perennial fountains
at will.
Page 609
Economizing Precipitation.
The methods suggested by Palissy and by Babinet are of limited
application, and designed only to supply a sufficient quantity of water for
the domestic use of small villages or large private establishments. Dumas
has proposed a much more extensive system for collecting and retaining the
whole precipitation in considerable valleys, and storing it in reservoirs,
whence it is to be drawn for household and mechanical purposes, for
irrigation, and, in short, for all the uses to which the water of natural springs
and brooks is applicable. His plan consists in draining both surface and
subsoil, by means of conduits differing in construction according to local
circumstances, but in the main not unlike those employed in improved
agriculture, collecting the water in a central channel, securing its proper
filterage, checking its too rapid flow by barriers at convenient points, and
finally receiving the whole in spacious, covered reservoirs, from which it
may he discharged in a constant flow or at intervals as convenience may
dictate. [Footnote: M. G. Dumas, La Science des Fontaines, 1857.]
There is no reasonable doubt that a very wide employment of these
various contrivances for economizing and supplying water is practicable,
and the expediency of resorting to them is almost purely an economical
question. There appears to be no serious reason to apprehend collateral evils
from them, and in fact all of them, except artesian wells, are simply indirect
methods of returning to the original arrangements of nature, or, in other
words, of restoring the fluid circulation of the globe; for when the earth was
covered with the forest, perennial springs gushed from the foot of every
hill, brooks flowed down the bed of every valley. The partial recovery of
the fountains and rivulets which once abundantly watered the face of the
agricultural world seems practicable by such means, even without any
general replanting of the forests; and the cost of one year's warfare—or in
some countries of that armed peace which has been called "Platonic war"—
The methods suggested by Palissy and by Babinet are of limited
application, and designed only to supply a sufficient quantity of water for
the domestic use of small villages or large private establishments. Dumas
has proposed a much more extensive system for collecting and retaining the
whole precipitation in considerable valleys, and storing it in reservoirs,
whence it is to be drawn for household and mechanical purposes, for
irrigation, and, in short, for all the uses to which the water of natural springs
and brooks is applicable. His plan consists in draining both surface and
subsoil, by means of conduits differing in construction according to local
circumstances, but in the main not unlike those employed in improved
agriculture, collecting the water in a central channel, securing its proper
filterage, checking its too rapid flow by barriers at convenient points, and
finally receiving the whole in spacious, covered reservoirs, from which it
may he discharged in a constant flow or at intervals as convenience may
dictate. [Footnote: M. G. Dumas, La Science des Fontaines, 1857.]
There is no reasonable doubt that a very wide employment of these
various contrivances for economizing and supplying water is practicable,
and the expediency of resorting to them is almost purely an economical
question. There appears to be no serious reason to apprehend collateral evils
from them, and in fact all of them, except artesian wells, are simply indirect
methods of returning to the original arrangements of nature, or, in other
words, of restoring the fluid circulation of the globe; for when the earth was
covered with the forest, perennial springs gushed from the foot of every
hill, brooks flowed down the bed of every valley. The partial recovery of
the fountains and rivulets which once abundantly watered the face of the
agricultural world seems practicable by such means, even without any
general replanting of the forests; and the cost of one year's warfare—or in
some countries of that armed peace which has been called "Platonic war"—
Page 610
if judiciously expended in a combination of both methods of improvement,
would secure, to almost every country that man has exhausted, an
amelioration of climate, a renovated fertility of soil, and a general physical
improvement, which might almost be characterized as a new creation.
Inundations and Torrents.
In pointing out in a former chapter the evils which have resulted from the
too extensive destruction of the forests, I dwelt at some length on the
increased violence of river inundations, and especially on the devastations
of torrents, in countries improvidently deprived of their woods, and I spoke
of the replanting of the forests as probably the most effectual method of
preventing the frequent recurrence of disastrous floods. There are many
regions where, from the loss of the superficial soil, from financial
considerations, and from other special causes, the general restoration of the
woods is not, under present circumstances, either possible or desirable. In
all inhabited countries, the necessities of agriculture and other
considerations of human convenience will always require the occupation of
much the largest proportion of the surface for purposes inconsistent with the
growth of extensive forests. Even where large plantations are possible and
in actual process of execution, many years must elapse before the action of
the destructive causes in question can be arrested or perhaps even sensibly
mitigated by their influence; and besides, floods will always occur in years
of excessive precipitation, whether the surface of the soil be generally
cleared or generally wooded. [Footnote: All the arrangements of rural
husbandry, and we might say of civilised occupancy of the earth, are such
as necessarily to increase the danger and the range of floods by promoting
the rapid discharge of the waters of precipitation. Superficial, if not
subterranean, drainage is a necessary condition of all agriculture. There is
no field which has not some artificial disposition for this purpose, and even
would secure, to almost every country that man has exhausted, an
amelioration of climate, a renovated fertility of soil, and a general physical
improvement, which might almost be characterized as a new creation.
Inundations and Torrents.
In pointing out in a former chapter the evils which have resulted from the
too extensive destruction of the forests, I dwelt at some length on the
increased violence of river inundations, and especially on the devastations
of torrents, in countries improvidently deprived of their woods, and I spoke
of the replanting of the forests as probably the most effectual method of
preventing the frequent recurrence of disastrous floods. There are many
regions where, from the loss of the superficial soil, from financial
considerations, and from other special causes, the general restoration of the
woods is not, under present circumstances, either possible or desirable. In
all inhabited countries, the necessities of agriculture and other
considerations of human convenience will always require the occupation of
much the largest proportion of the surface for purposes inconsistent with the
growth of extensive forests. Even where large plantations are possible and
in actual process of execution, many years must elapse before the action of
the destructive causes in question can be arrested or perhaps even sensibly
mitigated by their influence; and besides, floods will always occur in years
of excessive precipitation, whether the surface of the soil be generally
cleared or generally wooded. [Footnote: All the arrangements of rural
husbandry, and we might say of civilised occupancy of the earth, are such
as necessarily to increase the danger and the range of floods by promoting
the rapid discharge of the waters of precipitation. Superficial, if not
subterranean, drainage is a necessary condition of all agriculture. There is
no field which has not some artificial disposition for this purpose, and even
Page 611
the furrows of ploughed land, if the surface is inclined, and especially when
it if frozen, serve rather to carry off than to retain water. As Bacquerel has
observed, common road and railway ditches are among the most efficient
conduits for the discharge of surface-water which man has yet constructed,
and of course they are powerful agents in causing river inundations. All
these channels are, indeed, necessary for the convenience of man, but this
convenience, like every other interference with the order of nature, must
often be purchased at a heavy cost.] Physical improvement in this respect,
then, cannot be confined to merely preventive measures, but, in countries
subject to damage by inundation, means must be contrived to obviate
dangers and diminish injuries to which human life and all the works of
human industry will occasionally be exposed, in spite of every effort to
lessen the frequency of their recurrence by acting directly on the causes that
produce them. As every civilized country is, in some degree, subject to
inundation by the overflow of rivers, the evil is a familiar one, and needs no
general description. In discussing this branch of the subject, therefore, I
may confine myself chiefly to the means that have been or may be
employed to resist the force and limit the ravages of floods, which, left
wholly unrestrained, would not only inflict immense injury upon the
material interests of man, but produce geographical revolutions of no little
magnitude.
Inundations of 1856 in France.
The month of May, 1856, was remarkable for violent and almost
uninterrupted rains, and most of the river-basins of France were inundated
to an extraordinary height. In the val-leys of the Loire and its aflluents,
about a million of acres, including many towns and villages, were laid
under water, and the amount of pecuniary damage was almost incalculable.
[Footnote: Champion, Les Inondations en France, iii., p.156, note.] The
it if frozen, serve rather to carry off than to retain water. As Bacquerel has
observed, common road and railway ditches are among the most efficient
conduits for the discharge of surface-water which man has yet constructed,
and of course they are powerful agents in causing river inundations. All
these channels are, indeed, necessary for the convenience of man, but this
convenience, like every other interference with the order of nature, must
often be purchased at a heavy cost.] Physical improvement in this respect,
then, cannot be confined to merely preventive measures, but, in countries
subject to damage by inundation, means must be contrived to obviate
dangers and diminish injuries to which human life and all the works of
human industry will occasionally be exposed, in spite of every effort to
lessen the frequency of their recurrence by acting directly on the causes that
produce them. As every civilized country is, in some degree, subject to
inundation by the overflow of rivers, the evil is a familiar one, and needs no
general description. In discussing this branch of the subject, therefore, I
may confine myself chiefly to the means that have been or may be
employed to resist the force and limit the ravages of floods, which, left
wholly unrestrained, would not only inflict immense injury upon the
material interests of man, but produce geographical revolutions of no little
magnitude.
Inundations of 1856 in France.
The month of May, 1856, was remarkable for violent and almost
uninterrupted rains, and most of the river-basins of France were inundated
to an extraordinary height. In the val-leys of the Loire and its aflluents,
about a million of acres, including many towns and villages, were laid
under water, and the amount of pecuniary damage was almost incalculable.
[Footnote: Champion, Les Inondations en France, iii., p.156, note.] The
Page 612
flood was not less destructive in the valley of the Rhone, and in fact an
invasion by a hostile army could hardly have been more disastrous to the
inhabitants of the plains than was this terrible deluge. There had been a
flood of this latter river in the year 1840, which, for height and quantity of
water, was almost as remarkable as that of 1856, but it took place in the
month of November, when the crops had all been harvested, and the injury
inflicted by it upon agriculturists was, therefore, of a character to be less
severely and less immediately felt than the consequences of the inundation
of 1856. [Footnote: Notwithstanding this favorable circumstance, the
damage done by the inundation of 1840 in the valley of the Rhone was
estimated at seventy-two millions of francs.—Champion, Les Inondations
en France, iv., p. 124.
Several smaller floods of the Rhone, experienced at a somewhat earlier
season of the year in 1846, occasioned a loss of forty-five millions of
francs. "What if," says Dumont, "instead of happening in October, that is,
between harvest and seedtime, they had occurred before the crops were
secured The damage would have been counted by hundreds of millions."—
Des Travaux Publics, p. 99, note.]
In the fifteen years between these two great floods, the population and
the rural improvements of the river valleys had much increased, common
roads, bridges, and railways had been multiplied and extended, telegraph
lines had been constructed, all of which shared in the general ruin, and
hence greater and more diversified interests were affected by the
catastrophe of 1856 than by any former like calamity. The great flood of
1840 had excited the attention and roused the sympathies of the French
people, and the subject was invested with new interest by the still more
formidable character of the inundations of 1856. It was felt that these
scourges had ceased to be a matter of merely local concern, for, although
they bore most heavily on those whose homes and fields were situated
invasion by a hostile army could hardly have been more disastrous to the
inhabitants of the plains than was this terrible deluge. There had been a
flood of this latter river in the year 1840, which, for height and quantity of
water, was almost as remarkable as that of 1856, but it took place in the
month of November, when the crops had all been harvested, and the injury
inflicted by it upon agriculturists was, therefore, of a character to be less
severely and less immediately felt than the consequences of the inundation
of 1856. [Footnote: Notwithstanding this favorable circumstance, the
damage done by the inundation of 1840 in the valley of the Rhone was
estimated at seventy-two millions of francs.—Champion, Les Inondations
en France, iv., p. 124.
Several smaller floods of the Rhone, experienced at a somewhat earlier
season of the year in 1846, occasioned a loss of forty-five millions of
francs. "What if," says Dumont, "instead of happening in October, that is,
between harvest and seedtime, they had occurred before the crops were
secured The damage would have been counted by hundreds of millions."—
Des Travaux Publics, p. 99, note.]
In the fifteen years between these two great floods, the population and
the rural improvements of the river valleys had much increased, common
roads, bridges, and railways had been multiplied and extended, telegraph
lines had been constructed, all of which shared in the general ruin, and
hence greater and more diversified interests were affected by the
catastrophe of 1856 than by any former like calamity. The great flood of
1840 had excited the attention and roused the sympathies of the French
people, and the subject was invested with new interest by the still more
formidable character of the inundations of 1856. It was felt that these
scourges had ceased to be a matter of merely local concern, for, although
they bore most heavily on those whose homes and fields were situated
Page 613
within the immediate reach of the swelling waters, yet they frequently
destroyed harvests valuable enough to be a matter of national interest,
endangered the personal security of the population of important political
centres, interrupted communication for days and even weeks together on
great lines of traffic and travel—thus severing, as it were, all South-western
France from the rest of the empire—and finally threatened to produce great
and permanent geographical changes. The well-being of the whole
commonwealth was seen to be involved in preventing the recurrence and in
limiting the range of such devastations. The Government encouraged
scientific investigation of the phenomena and their laws. Their causes, their
history, their immediate and remote consequences, and the possible
safeguards to be employed against them, have been carefully studied by the
most eminent physicists, as well as by the ablest theoretical and practical
engineers of France. Many hitherto unobserved facts have been collected,
many new hypotheses suggested, and many plans, more or less original in
character, have been devised for combating the evil; but thus far, the most
competent judges are not well agreed as to the mode, or even the possibility,
of applying an effectual remedy. I have noticed in the next preceding
chapter the recent legislation of France upon the preservation and
restoration of the forests, with reference to their utility in subduing torrents
and lessening the frequency and diminishing the violence of river
inundations. The provisions of those laws are preventive rather than
remedial, but most beneficial effects have already been experienced from
the measures adopted in pursuance of them, though sufficient time has not
yet elapsed for the complete execution of the greater operations of the
system.
Basins of Reception.
destroyed harvests valuable enough to be a matter of national interest,
endangered the personal security of the population of important political
centres, interrupted communication for days and even weeks together on
great lines of traffic and travel—thus severing, as it were, all South-western
France from the rest of the empire—and finally threatened to produce great
and permanent geographical changes. The well-being of the whole
commonwealth was seen to be involved in preventing the recurrence and in
limiting the range of such devastations. The Government encouraged
scientific investigation of the phenomena and their laws. Their causes, their
history, their immediate and remote consequences, and the possible
safeguards to be employed against them, have been carefully studied by the
most eminent physicists, as well as by the ablest theoretical and practical
engineers of France. Many hitherto unobserved facts have been collected,
many new hypotheses suggested, and many plans, more or less original in
character, have been devised for combating the evil; but thus far, the most
competent judges are not well agreed as to the mode, or even the possibility,
of applying an effectual remedy. I have noticed in the next preceding
chapter the recent legislation of France upon the preservation and
restoration of the forests, with reference to their utility in subduing torrents
and lessening the frequency and diminishing the violence of river
inundations. The provisions of those laws are preventive rather than
remedial, but most beneficial effects have already been experienced from
the measures adopted in pursuance of them, though sufficient time has not
yet elapsed for the complete execution of the greater operations of the
system.
Basins of Reception.
Page 614
Destructive inundations of large rivers are seldom, if ever, produced by
precipitation within the limits of the principal valley, but almost uniformly
by sudden thaws or excessive rains on the mountain ranges where the
tributaries take their rise. It is therefore plain that any measures which shall
check the flow of surface-waters into the channels of the affluents, or which
shall retard the delivery of such waters into the principal stream by its
tributaries, will diminish in the same proportion the dangers and the evils of
inundation by great rivers. The retention of the surface-waters upon or in
the soil can hardly be accomplished except by the methods already
mentioned, replanting of forests, and furrowing or terracing. The current of
mountain streams can be checked by various methods, among which the
most familiar and obvious is the erection of barriers or dams across their
channels, at points convenient for forming reservoirs large enough to retain
the superfluous waters of great rains and thaws. [Footnote: On the
construction of temporary and more permanent barriera to the curreuts of
torrents and rivulets, see Marchand, Les Torrents des Alpes, in Recue des
Eaux et Forets for October and November, 1871.]
Besides the utility of such basins in preventing floods, the construction of
them is recommended by very strong considerations, such as the furnishing
of a constant supply of water for agricultural and mechanical purposes, and,
also, their value as ponds for breeding and rearing fish, and, perhaps, for
cultivating aquatic vegetables. [Footnote: In reference to the utilization of
artificial as well as natural reservoirs, see Ackerhof, Die Nutruny der Teiche
und Gewasser, Quadlinburg, 1869.]
The objections to the general adoption of the system of reservoirs are
these: the expense of their construction and maintenance; the reduction of
cultivable area by the amount of surface they must cover; the interruption
they would occasion to free communication; the probability that they would
soon be filled up with sediment, and the obvious fact that when full of
precipitation within the limits of the principal valley, but almost uniformly
by sudden thaws or excessive rains on the mountain ranges where the
tributaries take their rise. It is therefore plain that any measures which shall
check the flow of surface-waters into the channels of the affluents, or which
shall retard the delivery of such waters into the principal stream by its
tributaries, will diminish in the same proportion the dangers and the evils of
inundation by great rivers. The retention of the surface-waters upon or in
the soil can hardly be accomplished except by the methods already
mentioned, replanting of forests, and furrowing or terracing. The current of
mountain streams can be checked by various methods, among which the
most familiar and obvious is the erection of barriers or dams across their
channels, at points convenient for forming reservoirs large enough to retain
the superfluous waters of great rains and thaws. [Footnote: On the
construction of temporary and more permanent barriera to the curreuts of
torrents and rivulets, see Marchand, Les Torrents des Alpes, in Recue des
Eaux et Forets for October and November, 1871.]
Besides the utility of such basins in preventing floods, the construction of
them is recommended by very strong considerations, such as the furnishing
of a constant supply of water for agricultural and mechanical purposes, and,
also, their value as ponds for breeding and rearing fish, and, perhaps, for
cultivating aquatic vegetables. [Footnote: In reference to the utilization of
artificial as well as natural reservoirs, see Ackerhof, Die Nutruny der Teiche
und Gewasser, Quadlinburg, 1869.]
The objections to the general adoption of the system of reservoirs are
these: the expense of their construction and maintenance; the reduction of
cultivable area by the amount of surface they must cover; the interruption
they would occasion to free communication; the probability that they would
soon be filled up with sediment, and the obvious fact that when full of
Page 615
earth, or even water, they would no longer serve their principal purpose; the
great danger to which they would expose the country below them in case of
the bursting of their barriers; [Footnote: For accounts of damage from the
bursting of reservoirs, see Vallee, Memoire sur les Reservoir d'Alimentation
des Canaux, Annales des Ponts et Chaussees, 1833, 1er semestre, p.261.
The dam of the reservoir of Puentes in Spain, which was one hundred
and sixty feet high, after having discharged its functions for eleven years,
burst, in 1802, in consequence of a defect in its foundations, and the
eruption of the water destroyed or seriously injured eight hundred houses,
and produced damage to the amount of more than a million dollars.—
Aynard, Irrigations du Midi d l'Europe, pp. 257-259.] the evil consequences
they would occasion by prolonging the flow of inundations in proportion as
they diminished their height; the injurious effects it is supposed they would
produce upon the salubrity of the neighbouring districts; and, lastly, the
alleged impossibility of constructing artificial basins sufficient in capacity
to prevent, or in any considerable measure to mitigate, the evils they are
intended to guard against.
The last argument is more easily reduced to a numerical question than the
others. The mean and extreme annual precipitation of all the basins where
the construction of such works would be seriously proposed is already
approximately known by meteorological tables, and the quantity of water,
delivered by the greatest floods which have occurred within the memory of
man, may be roughly estimated from their visible traces. From these
elements, or from meteorological records, the capacity of the necessary
reservoirs can be calculated. Let us take the case of the Ardeche. In the
inundation of 1857, that river poured into the Rhone 1,305,000,000 cubic
yards of water in three days. If we suppose that half this quantity might
have been suffered to flow down its channel without inconvenience, we
shall have about 650,000,000 cubic yards to provide for by reservoirs. The
great danger to which they would expose the country below them in case of
the bursting of their barriers; [Footnote: For accounts of damage from the
bursting of reservoirs, see Vallee, Memoire sur les Reservoir d'Alimentation
des Canaux, Annales des Ponts et Chaussees, 1833, 1er semestre, p.261.
The dam of the reservoir of Puentes in Spain, which was one hundred
and sixty feet high, after having discharged its functions for eleven years,
burst, in 1802, in consequence of a defect in its foundations, and the
eruption of the water destroyed or seriously injured eight hundred houses,
and produced damage to the amount of more than a million dollars.—
Aynard, Irrigations du Midi d l'Europe, pp. 257-259.] the evil consequences
they would occasion by prolonging the flow of inundations in proportion as
they diminished their height; the injurious effects it is supposed they would
produce upon the salubrity of the neighbouring districts; and, lastly, the
alleged impossibility of constructing artificial basins sufficient in capacity
to prevent, or in any considerable measure to mitigate, the evils they are
intended to guard against.
The last argument is more easily reduced to a numerical question than the
others. The mean and extreme annual precipitation of all the basins where
the construction of such works would be seriously proposed is already
approximately known by meteorological tables, and the quantity of water,
delivered by the greatest floods which have occurred within the memory of
man, may be roughly estimated from their visible traces. From these
elements, or from meteorological records, the capacity of the necessary
reservoirs can be calculated. Let us take the case of the Ardeche. In the
inundation of 1857, that river poured into the Rhone 1,305,000,000 cubic
yards of water in three days. If we suppose that half this quantity might
have been suffered to flow down its channel without inconvenience, we
shall have about 650,000,000 cubic yards to provide for by reservoirs. The
Page 616
Ardeche and its principal affluent, the Chassezae, have, together, about
twelve considerable tributaries rising near the crest of the mountains which
bound the basin. If reservoirs of equal capacity were constructed upon all of
them, each reservoir must be able to contain 54,000,000 cubic yards, or, in
other words, must be equal to a lake 3,000 yards long, 1,000 yards wide,
and 18 yards deep, and besides, in order to render any effectual service, the
reservoirs must all have been empty at the commencement of the rains
which produced the inundation.
Thus far I have supposed the swelling of the waters to be uniform
throughout the whole basin; but such was by no means the fact in the
inundation of 1857, for the rise of the Chassezae, which is as large as the
Ardeche proper, did not exceed the limits of ordinary floods, and the
dangerous excess came solely from the headwaters of the latter stream.
Hence reservoirs of double the capacity I have supposed would have been
necessary upon the tributaries of that river, to prevent the injurious effects
of the inundation. It is evident that the construction of reservoirs of such
magnitude for such a purpose is financially, if not physically, impracticable,
and when we take into account a point I have just suggested, namely, that
the reservoirs must be empty at all times of apprehended flood, and, of
course, their utility limited almost solely to the single object of preventing
inundations, the total inapplicability of such a measure in this particular
case becomes still more glaringly manifest.
Another not less conclusive fact is, that the valleys of all the upland
tributaries of the Ardeche descend so rapidly, and have so little lateral
expansion, as to render the construction of capacious reservoirs in them
quite impracticable. Indeed, engineers have found but two points in the
whole basin suitable for that purpose, and the reservoirs admissible at these
would have only a joint capacity of about 70,000,000 cubic yards, or less
than one-ninth part of what I suppose to be required. The case of the
twelve considerable tributaries rising near the crest of the mountains which
bound the basin. If reservoirs of equal capacity were constructed upon all of
them, each reservoir must be able to contain 54,000,000 cubic yards, or, in
other words, must be equal to a lake 3,000 yards long, 1,000 yards wide,
and 18 yards deep, and besides, in order to render any effectual service, the
reservoirs must all have been empty at the commencement of the rains
which produced the inundation.
Thus far I have supposed the swelling of the waters to be uniform
throughout the whole basin; but such was by no means the fact in the
inundation of 1857, for the rise of the Chassezae, which is as large as the
Ardeche proper, did not exceed the limits of ordinary floods, and the
dangerous excess came solely from the headwaters of the latter stream.
Hence reservoirs of double the capacity I have supposed would have been
necessary upon the tributaries of that river, to prevent the injurious effects
of the inundation. It is evident that the construction of reservoirs of such
magnitude for such a purpose is financially, if not physically, impracticable,
and when we take into account a point I have just suggested, namely, that
the reservoirs must be empty at all times of apprehended flood, and, of
course, their utility limited almost solely to the single object of preventing
inundations, the total inapplicability of such a measure in this particular
case becomes still more glaringly manifest.
Another not less conclusive fact is, that the valleys of all the upland
tributaries of the Ardeche descend so rapidly, and have so little lateral
expansion, as to render the construction of capacious reservoirs in them
quite impracticable. Indeed, engineers have found but two points in the
whole basin suitable for that purpose, and the reservoirs admissible at these
would have only a joint capacity of about 70,000,000 cubic yards, or less
than one-ninth part of what I suppose to be required. The case of the
Page 617
Ardeche is no doubt an extreme one, both in the topographical character of
its basin and in its exposure to excessive rains; but all destructive
inundations are, in a certain sense, extreme cases also, and this of the
Ardeche serves to show that the construction of reservoirs is not by any
means to be regarded as a universal panacea against floods.
Nor, on the other hand, is this measure to be summarily rejected. Nature
has adopted it on a great scale, on both flanks of the Alps, and on a smaller,
on those of the Adirondacks and of many lower chains. The quantity of
water which, in great rains or sudden thaws, rushes down the steep
declivities of the Alps, is so vast that the channels of the Swiss and Italian
rivers would be totally incompetent to carry it off as rapidly as it would
pour into them, were it not absorbed by the capacious basins which nature
has scooped out for its reception, freed from the transported material which
adds immensely both to the volume and to the force of its current, and then,
after some reduction by evaporation and infiltration, gradually discharged
into the beds of the rivers. In the inundation of 1829 the water discharged
into Lake Como from the 15th to the 20th of September amounted to 2,600
cubic yards the second, while the outflow from the lake during the same
period was only at the rate of about 1,050 cubic yards to the second. In
those five days, then, the lake accumulated 670,000,000 cubic yards of
superfluous water, and of course diminished by so much the quantity to be
disposed of by the Po. [Footnote: Baird Smith, Italian Irrigation, i., p. 176.]
In the flood of October, 1868, the surface of Lago Maggiore was raised
twenty-five feet above low-water mark in the course of a few hours.
[Footnote: Bollettino della Societa Geog. Italiana, iii., p. 466.] There can be
no doubt that without such detention of water by the Lakes Como,
Maggiore, Garda, and other subalpine basins, almost the whole of
Lombardy would have been irrecoverably desolated, or rather, its great
plain would never have become anything but a vast expanse of river-beds
and marshes; for the annual floods would always have prevented the
its basin and in its exposure to excessive rains; but all destructive
inundations are, in a certain sense, extreme cases also, and this of the
Ardeche serves to show that the construction of reservoirs is not by any
means to be regarded as a universal panacea against floods.
Nor, on the other hand, is this measure to be summarily rejected. Nature
has adopted it on a great scale, on both flanks of the Alps, and on a smaller,
on those of the Adirondacks and of many lower chains. The quantity of
water which, in great rains or sudden thaws, rushes down the steep
declivities of the Alps, is so vast that the channels of the Swiss and Italian
rivers would be totally incompetent to carry it off as rapidly as it would
pour into them, were it not absorbed by the capacious basins which nature
has scooped out for its reception, freed from the transported material which
adds immensely both to the volume and to the force of its current, and then,
after some reduction by evaporation and infiltration, gradually discharged
into the beds of the rivers. In the inundation of 1829 the water discharged
into Lake Como from the 15th to the 20th of September amounted to 2,600
cubic yards the second, while the outflow from the lake during the same
period was only at the rate of about 1,050 cubic yards to the second. In
those five days, then, the lake accumulated 670,000,000 cubic yards of
superfluous water, and of course diminished by so much the quantity to be
disposed of by the Po. [Footnote: Baird Smith, Italian Irrigation, i., p. 176.]
In the flood of October, 1868, the surface of Lago Maggiore was raised
twenty-five feet above low-water mark in the course of a few hours.
[Footnote: Bollettino della Societa Geog. Italiana, iii., p. 466.] There can be
no doubt that without such detention of water by the Lakes Como,
Maggiore, Garda, and other subalpine basins, almost the whole of
Lombardy would have been irrecoverably desolated, or rather, its great
plain would never have become anything but a vast expanse of river-beds
and marshes; for the annual floods would always have prevented the
Page 618
possibility of its improvement by man. [Footnote: See, as to the probable
effects of certain proposed hydraulic works at the outlet of Lake Maggiore
on the action of the lake as a regulating reservoir, Tagliasecchi, Notizie sui
Canali dell' Alta Lombardia, Milano, 1869.]
Lake Bourget in Savoy, once much more extensive than it is at present,
served, and indeed still serves, a similar purpose in the economy of nature.
In a flood of the Rhone, in 1863, this lake received from the overflow of
that river, which does not pass through it, 72,000,000 cubic yards of water,
and of course moderated, to that extent, the effects of the inundation below.
[Footnote: Elisee Recluse, La Terre, i., p. 460.]
In fact, the alluvial plains which border the course of most considerable
streams, and are overflowed in their inundations, either by the rise of the
water to a higher level than that of their banks, or by the bursting of their
dikes, serve as safety-valves for the escape of their superfluous waters. The
current of the Po, spreading over the whole space between its widely
separated embankments, takes up so much water in its inundations, that,
while a little below the outlet of the Ticino the discharge of the channel is
sometimes not less than 19,500 cubic yards to the second, it has never
exceeded 6,730 yards at Ponte Lagoscuro, near Ferrara. The currents of the
Mississippi, the Rhone, and of many other large rivers, are modified in the
same way. In the flood of 1858, the delivery of the Mississippi, a little
below the month of the Ohio, was 52,000 cubic yards to the second, but at
Baton Rouge, though of course increased by the waters of the Arkansas, the
Yazoo, and other smaller tributaries, the discharge was reduced to 46,760
cubic yards. We rarely err when we cautiously imitate the processes of
nature, and there are doubtless many cases where artificial basins of
reception and lateral expansions of river-beds might be employed with
advantage. Many upland streams present points where none of the
objections usually urged against artificial reservoirs, except those of
effects of certain proposed hydraulic works at the outlet of Lake Maggiore
on the action of the lake as a regulating reservoir, Tagliasecchi, Notizie sui
Canali dell' Alta Lombardia, Milano, 1869.]
Lake Bourget in Savoy, once much more extensive than it is at present,
served, and indeed still serves, a similar purpose in the economy of nature.
In a flood of the Rhone, in 1863, this lake received from the overflow of
that river, which does not pass through it, 72,000,000 cubic yards of water,
and of course moderated, to that extent, the effects of the inundation below.
[Footnote: Elisee Recluse, La Terre, i., p. 460.]
In fact, the alluvial plains which border the course of most considerable
streams, and are overflowed in their inundations, either by the rise of the
water to a higher level than that of their banks, or by the bursting of their
dikes, serve as safety-valves for the escape of their superfluous waters. The
current of the Po, spreading over the whole space between its widely
separated embankments, takes up so much water in its inundations, that,
while a little below the outlet of the Ticino the discharge of the channel is
sometimes not less than 19,500 cubic yards to the second, it has never
exceeded 6,730 yards at Ponte Lagoscuro, near Ferrara. The currents of the
Mississippi, the Rhone, and of many other large rivers, are modified in the
same way. In the flood of 1858, the delivery of the Mississippi, a little
below the month of the Ohio, was 52,000 cubic yards to the second, but at
Baton Rouge, though of course increased by the waters of the Arkansas, the
Yazoo, and other smaller tributaries, the discharge was reduced to 46,760
cubic yards. We rarely err when we cautiously imitate the processes of
nature, and there are doubtless many cases where artificial basins of
reception and lateral expansions of river-beds might be employed with
advantage. Many upland streams present points where none of the
objections usually urged against artificial reservoirs, except those of
Page 619
expense and of danger from the breaking of dams, could have any
application. Reservoirs may be so constructed as to retain the entire
precipitation of the heaviest thaws and rains, leaving only the ordinary
quantity to flow along the channel; they may be raised to such a height as
only partially to obstruct the surface drainage; or they may be provided with
sluices by means of which their whole contents can be discharged in the dry
season and a summer crop be grown upon the ground they cover at high
water. The expediency of employing them and the mode of construction
depend on local conditions, and no rules of universal applicability can be
laid down on the subject. [Footnote: The insufficiency of artificial basins of
reception as a means of averting the evils resulting from the floods of great
rivers has been conclusively shown, in reference to a most important
particular case—that of the Mississippi—by Humphreys and Abbot, in their
admirable monograph of that river.]
It is remarkable that nations which we, in the inflated pride of our
modern civilization, so generally regard as little less than barbarian, should
have long preceded Christian Europe in the systematic employment of great
artificial basins for the various purposes they are calculated to subserve.
The ancient Peruvians built strong walls, of excellent workmanship, across
the channels of the mountain sources of important streams, and the Arabs
executed immense works of similar description, both in the great Arabian
peninsula and in all the provinces of Spain which had the good fortune to
fall under their sway. The Spaniards of the fifteenth and sixteenth centuries,
who, in many points of true civilization and culture, were far inferior to the
races they subdued, wantonly destroyed these noble monuments of social
and political wisdom, or suffered them to perish, because they were too
ignorant to appreciate their value, or too unskilful as practical engineers to
be able to maintain them, and some of their most important territories were
soon reduced to sterility and poverty in consequence.
application. Reservoirs may be so constructed as to retain the entire
precipitation of the heaviest thaws and rains, leaving only the ordinary
quantity to flow along the channel; they may be raised to such a height as
only partially to obstruct the surface drainage; or they may be provided with
sluices by means of which their whole contents can be discharged in the dry
season and a summer crop be grown upon the ground they cover at high
water. The expediency of employing them and the mode of construction
depend on local conditions, and no rules of universal applicability can be
laid down on the subject. [Footnote: The insufficiency of artificial basins of
reception as a means of averting the evils resulting from the floods of great
rivers has been conclusively shown, in reference to a most important
particular case—that of the Mississippi—by Humphreys and Abbot, in their
admirable monograph of that river.]
It is remarkable that nations which we, in the inflated pride of our
modern civilization, so generally regard as little less than barbarian, should
have long preceded Christian Europe in the systematic employment of great
artificial basins for the various purposes they are calculated to subserve.
The ancient Peruvians built strong walls, of excellent workmanship, across
the channels of the mountain sources of important streams, and the Arabs
executed immense works of similar description, both in the great Arabian
peninsula and in all the provinces of Spain which had the good fortune to
fall under their sway. The Spaniards of the fifteenth and sixteenth centuries,
who, in many points of true civilization and culture, were far inferior to the
races they subdued, wantonly destroyed these noble monuments of social
and political wisdom, or suffered them to perish, because they were too
ignorant to appreciate their value, or too unskilful as practical engineers to
be able to maintain them, and some of their most important territories were
soon reduced to sterility and poverty in consequence.
Page 620
Diversion of Rivers.
Another method of preventing or diminishing the evils of inundation by
torrents and mountain rivers, analogous to that employed for the drainage of
lakes, consists in the permanent or occasional diversion of their surplus
waters, or of their entire currents, from their natural courses, by tunnels or
open channels cut through their banks. Nature, in many cases, resorts to a
similar process. Most great rivers divide themselves into several arms in
their lower course, and enter the sea by different mouths. There are also
cases where rivers send off lateral branches to convey a part of their waters
into the channel of other streams. [Footnote: Some geographical writers
apply the term bifurcation exclusively to this intercommunication of rivers;
others, with more etymological propriety, use it to express the division of
great rivers into branches at the head of their deltas. A technical word is
wanting to designate the phenomenon mentioned in the text, and there is no
valid objection to the employment of the anatomical term anastomosis for
this purpose.] The most remarkable of these is the junction between the
Amazon and the Orinoco by the natural canal of the Cassiquiare and the Rio
Negro. In India, the Cambodja and the Menam are connected by the Anam;
the Saluen and the Irawaddi by the Panlaun. There are similar examples,
though on a much smaller scale, in Europe. The Tornea, and the Calix rivers
in Lapland communicate by the Tarando, and in Westphalia, the Else, an
arm of the Haase, falls into the Weser. [Footnote: The division of the
currents of rivers, as a means of preventing the overflow of their banks, is
by no means a remedy capable of general application, even when local
conditions are favorable to the construction of an emissary. The velocity of
a stream, and consequently its delivery in a given time, are frequently
diminished in proportion to the diminution of the volume by diversion; and
on the other hand, the increase of volume by the admission of a new
tributary increases proportionally the velocity and the quantity of water
delivered. Emissaries may, nevertheless, often be useful in carrying off
Another method of preventing or diminishing the evils of inundation by
torrents and mountain rivers, analogous to that employed for the drainage of
lakes, consists in the permanent or occasional diversion of their surplus
waters, or of their entire currents, from their natural courses, by tunnels or
open channels cut through their banks. Nature, in many cases, resorts to a
similar process. Most great rivers divide themselves into several arms in
their lower course, and enter the sea by different mouths. There are also
cases where rivers send off lateral branches to convey a part of their waters
into the channel of other streams. [Footnote: Some geographical writers
apply the term bifurcation exclusively to this intercommunication of rivers;
others, with more etymological propriety, use it to express the division of
great rivers into branches at the head of their deltas. A technical word is
wanting to designate the phenomenon mentioned in the text, and there is no
valid objection to the employment of the anatomical term anastomosis for
this purpose.] The most remarkable of these is the junction between the
Amazon and the Orinoco by the natural canal of the Cassiquiare and the Rio
Negro. In India, the Cambodja and the Menam are connected by the Anam;
the Saluen and the Irawaddi by the Panlaun. There are similar examples,
though on a much smaller scale, in Europe. The Tornea, and the Calix rivers
in Lapland communicate by the Tarando, and in Westphalia, the Else, an
arm of the Haase, falls into the Weser. [Footnote: The division of the
currents of rivers, as a means of preventing the overflow of their banks, is
by no means a remedy capable of general application, even when local
conditions are favorable to the construction of an emissary. The velocity of
a stream, and consequently its delivery in a given time, are frequently
diminished in proportion to the diminution of the volume by diversion; and
on the other hand, the increase of volume by the admission of a new
tributary increases proportionally the velocity and the quantity of water
delivered. Emissaries may, nevertheless, often be useful in carrying off
Page 621
water which has already escaped from the channel and which would
otherwise become stagnant and prevent further lateral discharge from the
main current, and it is upon this principle that Humphreys and Abbot think
a canal of diversion at Lake Providence might be advisable. Emissaries
serve an important purpose in the lower course of rivers where the bed is
nearly a dead level and the water moves from previously acquired
momentum and the pressure of the current above, rather than by the force of
gravitation, and it is, in general, only under such circumstances, as for
example in the deltas at the mouths of great rivers, that nature employs
them.]
The change of bed in rivers by gradual erosion of their banks is familiar
to all, but instances of the sudden abandonment of a primitive channel are
by no means wanting. At a period of unknown antiquity, the Ardeche
pierced a tunnel 200 feet wide and 100 high, through a rock, and sent its
whole current through it, deserting its former bed, which gradually filled
up, though its course remained traceable. In the great inundation of 1827,
the tunnel proved insufficient for the discharge of the water, and the river
burst through the obstructions which had now choked up its ancient
channel, and resumed its original course. [Footnote: Mardigny, Memoire
sur les Inondations de l'Ardeche, p. 13.]
It was probably such facts as these that suggested to ancient engineers the
possibility of like artificial operations, and there are numerous instances of
the execution of works for this purpose in very remote ages. The Bahr
Jusef, the great stream which supplies the Fayoum with water from the
Nile, has been supposed, by some writers, to be a natural channel; but both
it and the Bahr el Wady are almost certainly artificial canals constructed to
water that basin, to regulate the level of Lake Meeris, and possibly, also, to
diminish the dangers resulting from excessive inundations of the Nile, by
serving as waste-weirs to discharge a part of its overflowing waters.
otherwise become stagnant and prevent further lateral discharge from the
main current, and it is upon this principle that Humphreys and Abbot think
a canal of diversion at Lake Providence might be advisable. Emissaries
serve an important purpose in the lower course of rivers where the bed is
nearly a dead level and the water moves from previously acquired
momentum and the pressure of the current above, rather than by the force of
gravitation, and it is, in general, only under such circumstances, as for
example in the deltas at the mouths of great rivers, that nature employs
them.]
The change of bed in rivers by gradual erosion of their banks is familiar
to all, but instances of the sudden abandonment of a primitive channel are
by no means wanting. At a period of unknown antiquity, the Ardeche
pierced a tunnel 200 feet wide and 100 high, through a rock, and sent its
whole current through it, deserting its former bed, which gradually filled
up, though its course remained traceable. In the great inundation of 1827,
the tunnel proved insufficient for the discharge of the water, and the river
burst through the obstructions which had now choked up its ancient
channel, and resumed its original course. [Footnote: Mardigny, Memoire
sur les Inondations de l'Ardeche, p. 13.]
It was probably such facts as these that suggested to ancient engineers the
possibility of like artificial operations, and there are numerous instances of
the execution of works for this purpose in very remote ages. The Bahr
Jusef, the great stream which supplies the Fayoum with water from the
Nile, has been supposed, by some writers, to be a natural channel; but both
it and the Bahr el Wady are almost certainly artificial canals constructed to
water that basin, to regulate the level of Lake Meeris, and possibly, also, to
diminish the dangers resulting from excessive inundations of the Nile, by
serving as waste-weirs to discharge a part of its overflowing waters.
Page 622
[Footnote: The starting-points of these anals were far up the Nile, and of
course at a comparatively high level, and it is probable that they received
water only during the inundation. Linant Bey calculates the capacity of
Lake Moeris at 3,686,667 cubic yards and the water received by it at high
Nile at 465 cubic yards the second.] Several of the seven ancient mouths of
the Nile are believed to be artificial channels, and Herodotus even asserts
that King Menes diverted the entire course of that river from the Libyan to
the Arabian side of the valley. There are traces of an ancient river-bed along
the western mountains, which give eome countenance to this statement. But
it is much more probable that the works of Menes were designed rather to
prevent a natural, than to produce an artificial, change in the channel of the
river.
Two of the most celebrated cascades in Europe, those of the Teverone at
Tivoli and of the Velino at Terni, owe, if not their existence, at least their
position and character, to the diversion of their waters from their natural
beds into new channels, in order to obviate the evils produced by their
frequent floods. Remarkable works of the same sort have been executed in
Switzerland, in very recent times. Until the year 1714, the Kander, which
drains several large Alpine valleys, ran, for a considerable distance, parallel
with the Lake of Thun, and a few miles below the city of that name emptied
into the river Aar. It frequently flooded the flats along the lower part of its
course, and it was determined to divert it into the Lake of Thun. For this
purpose, two parallel tunnels were cut through the intervening rock, and the
river turned into them. The violence of the current burst up the roof of the
tunnels, and, in a very short time, wore the new channel down not less than
one hundred feet, and even deepened the former bed at least fifty feet, for a
distance of two or three miles above the tunnel. The lake was two hundred
feet deep at the point where the river was conducted into it, but the gravel
and sand carried down by the Kander has formed at its mouth a delta
containing more than a hundred acres, which is still advancing at the rate of
course at a comparatively high level, and it is probable that they received
water only during the inundation. Linant Bey calculates the capacity of
Lake Moeris at 3,686,667 cubic yards and the water received by it at high
Nile at 465 cubic yards the second.] Several of the seven ancient mouths of
the Nile are believed to be artificial channels, and Herodotus even asserts
that King Menes diverted the entire course of that river from the Libyan to
the Arabian side of the valley. There are traces of an ancient river-bed along
the western mountains, which give eome countenance to this statement. But
it is much more probable that the works of Menes were designed rather to
prevent a natural, than to produce an artificial, change in the channel of the
river.
Two of the most celebrated cascades in Europe, those of the Teverone at
Tivoli and of the Velino at Terni, owe, if not their existence, at least their
position and character, to the diversion of their waters from their natural
beds into new channels, in order to obviate the evils produced by their
frequent floods. Remarkable works of the same sort have been executed in
Switzerland, in very recent times. Until the year 1714, the Kander, which
drains several large Alpine valleys, ran, for a considerable distance, parallel
with the Lake of Thun, and a few miles below the city of that name emptied
into the river Aar. It frequently flooded the flats along the lower part of its
course, and it was determined to divert it into the Lake of Thun. For this
purpose, two parallel tunnels were cut through the intervening rock, and the
river turned into them. The violence of the current burst up the roof of the
tunnels, and, in a very short time, wore the new channel down not less than
one hundred feet, and even deepened the former bed at least fifty feet, for a
distance of two or three miles above the tunnel. The lake was two hundred
feet deep at the point where the river was conducted into it, but the gravel
and sand carried down by the Kander has formed at its mouth a delta
containing more than a hundred acres, which is still advancing at the rate of
Page 623
several yards a year. The Linth, which formerly sent its waters directly to
the Lake of Zurich, and often produced very destructive inundations, was
turned into the Wallensee about fifty years ago, and in both these cases a
great quantity of valuable land was rescued both from flood and from
insalubrity.
Glacier Lakes.
In Switzerland, the most terrible inundations often result from the
damming up of deep valleys by ice-slips or by the gradual advance of
glaciers, and the accumulation of great masses of water above the
obstructions. The ice is finally dissolved by the heat of summer or the flow
of warm waters, and when it bursts, the lake formed above is discharged
almost in an instant, and all below is swept down to certain destruction. In
1595, about a hundred and fifty lives and a great amount of property were
lost by the eruption of a lake formed by the descent of a glacier into the
valley of the Drance, and a similar calamity laid waste a considerable extent
of soil in the year 1818. On this latter occasion, the barrier of ice and snow
was 3,000 feet long, 600 thick, and 400 high, and the lake which had
formed above it contained not less than 800,000,000 cubic feet. A tunnel
was driven through the ice, and about 300,000,000 cubic feet of water
safely drawn off by it, but the thawing of the walls of the tunnel rapidly
enlarged it, and before the lake was half drained, the barrier gave way and
the remaining 500,000,000 cubic feet of water were discharged in half an
hour. The recurrence of these floods has since been prevented by directing
streams of water, warmed by the sun, upon the ice in the bed of the valley,
and thus thawing it before it accumulates in sufficient mass to form a new
barrier and threaten serious danger. [Footnote: In 1845 a similar lake was
formed by the extension of the Vernagt glacier. When the ice barrier gave
way, 3,000,000 cubic yards of water were discharged in an hour.—Sonklar,
the Lake of Zurich, and often produced very destructive inundations, was
turned into the Wallensee about fifty years ago, and in both these cases a
great quantity of valuable land was rescued both from flood and from
insalubrity.
Glacier Lakes.
In Switzerland, the most terrible inundations often result from the
damming up of deep valleys by ice-slips or by the gradual advance of
glaciers, and the accumulation of great masses of water above the
obstructions. The ice is finally dissolved by the heat of summer or the flow
of warm waters, and when it bursts, the lake formed above is discharged
almost in an instant, and all below is swept down to certain destruction. In
1595, about a hundred and fifty lives and a great amount of property were
lost by the eruption of a lake formed by the descent of a glacier into the
valley of the Drance, and a similar calamity laid waste a considerable extent
of soil in the year 1818. On this latter occasion, the barrier of ice and snow
was 3,000 feet long, 600 thick, and 400 high, and the lake which had
formed above it contained not less than 800,000,000 cubic feet. A tunnel
was driven through the ice, and about 300,000,000 cubic feet of water
safely drawn off by it, but the thawing of the walls of the tunnel rapidly
enlarged it, and before the lake was half drained, the barrier gave way and
the remaining 500,000,000 cubic feet of water were discharged in half an
hour. The recurrence of these floods has since been prevented by directing
streams of water, warmed by the sun, upon the ice in the bed of the valley,
and thus thawing it before it accumulates in sufficient mass to form a new
barrier and threaten serious danger. [Footnote: In 1845 a similar lake was
formed by the extension of the Vernagt glacier. When the ice barrier gave
way, 3,000,000 cubic yards of water were discharged in an hour.—Sonklar,
Page 624
Die Oetzthaler Gebirgsgruppe, section 167.] In the cases of diversion of
streams above mentioned, important geographical changes have been
directly produced by those operations. By the rarer process of draining
glacier lakes, natural eruptions of water, which would have occasioned not
less important changes in the face of the earth, have been prevented by
human agency. River Embankments. The most obvious and doubtless
earliest method of preventing the escape of river-waters from their natural
channels, and the overflow of fields and towns by their spread, is that of
raised embankments along their course. [Footnote: Riparian embankments
are a real, if not a conscious, imitation of a natural process. The waters of
rivers which flow down planes of gentle inclination deposit, in their
inundations, the largest proportion of their sediment as soon as, by
overflowing their banks, they escape from the swift current of the channel.
The immediate borders of such rivers consequently become higher than the
grounds lying further from the stream, and constitute, of themselves, a sort
of natural dike of small elevation. In the "intervales" or "bottoms" of the
great North American rivers the alluvial banks are elevated and dry, the flats
more remote from the river lower and swampy. This is generally observable
in Egypt (see Figari Bey, Studi Scientifici sull' Egitto, i, p. 87), though less
so than in the valley of the Mississippi, where the alluvial banks form
natural glacis, descending as you recede from the river, and in some places,
as below Cape Girardeau, at the rate of seven feet in the first mile.
Humphreys and Abbott, Report, pp. 96, 97.
In fact, rivers, like mountain torrents, often run for a long distance on the
summit of a ridge built up by their own deposits. The delta of the
Mississippi is a regular cone, or rather mountain, of dejection, extending far
out into the Gulf of Mexico, along the crest of which the river flows,
sending off here and there, as it approaches the sea, a system of lateral
streams resembling the fan-shaped discharge of a torrent.] The necessity of
such embankments usually arises from the gradual elevation of the bed of
streams above mentioned, important geographical changes have been
directly produced by those operations. By the rarer process of draining
glacier lakes, natural eruptions of water, which would have occasioned not
less important changes in the face of the earth, have been prevented by
human agency. River Embankments. The most obvious and doubtless
earliest method of preventing the escape of river-waters from their natural
channels, and the overflow of fields and towns by their spread, is that of
raised embankments along their course. [Footnote: Riparian embankments
are a real, if not a conscious, imitation of a natural process. The waters of
rivers which flow down planes of gentle inclination deposit, in their
inundations, the largest proportion of their sediment as soon as, by
overflowing their banks, they escape from the swift current of the channel.
The immediate borders of such rivers consequently become higher than the
grounds lying further from the stream, and constitute, of themselves, a sort
of natural dike of small elevation. In the "intervales" or "bottoms" of the
great North American rivers the alluvial banks are elevated and dry, the flats
more remote from the river lower and swampy. This is generally observable
in Egypt (see Figari Bey, Studi Scientifici sull' Egitto, i, p. 87), though less
so than in the valley of the Mississippi, where the alluvial banks form
natural glacis, descending as you recede from the river, and in some places,
as below Cape Girardeau, at the rate of seven feet in the first mile.
Humphreys and Abbott, Report, pp. 96, 97.
In fact, rivers, like mountain torrents, often run for a long distance on the
summit of a ridge built up by their own deposits. The delta of the
Mississippi is a regular cone, or rather mountain, of dejection, extending far
out into the Gulf of Mexico, along the crest of which the river flows,
sending off here and there, as it approaches the sea, a system of lateral
streams resembling the fan-shaped discharge of a torrent.] The necessity of
such embankments usually arises from the gradual elevation of the bed of
Page 625
running streams in consequence of the deposit of the earth and gravel they
are charged with in high water; and, as we have seen, this elevation is
rapidly accelerated when the highlands around the headwaters of rivers are
cleared of their forests. When a river is embanked at a given point, and,
consequently, the water of its floods, which would otherwise spread over a
wide surface, is confined within narrow limits, the velocity of the current
and its transporting power are augmented, and its burden of sand and gravel
is deposited at some lower point, where the rapidity of its flow is checked
by a dam or other artificial obstruction, by a diminution in the inclination of
the bed, by a wider channel, or finally by a lacustrine or marine basin which
receives its waters. Wherever it lets fall solid material, its channel is raised
in consequence, and the declivity of the whole bed between the head of the
embankment and the slack of the stream is reduced. Hence the current, at
first accelerated by confinement, is afterwards checked by the mechanical
resistance of the matter deposited, and by the diminished inclination of its
channel, and then begins again to let fall the earth it holds in suspension,
and to raise its bed at the point where its overflow had been before
prevented by embankment. [Footnote: In proportion as the dikes are
improved, and breaches and the escape of the water through them are less
frequent, the height of the annual inundations is increased. Some towns on
the banks of the Po, and of course within the system of parallel
embankments, were formerly secure from flood by the height of the
artificial mounds on which they were built; but they have recently been
obliged to construct ring-dikes for their protection.
Lombardini lays down the following general statement of the effects of
river embankments:
"The immediate effect of embanking a river is generally an increase in
the height of its floods, but, at the same time, a depression of its bed, by
are charged with in high water; and, as we have seen, this elevation is
rapidly accelerated when the highlands around the headwaters of rivers are
cleared of their forests. When a river is embanked at a given point, and,
consequently, the water of its floods, which would otherwise spread over a
wide surface, is confined within narrow limits, the velocity of the current
and its transporting power are augmented, and its burden of sand and gravel
is deposited at some lower point, where the rapidity of its flow is checked
by a dam or other artificial obstruction, by a diminution in the inclination of
the bed, by a wider channel, or finally by a lacustrine or marine basin which
receives its waters. Wherever it lets fall solid material, its channel is raised
in consequence, and the declivity of the whole bed between the head of the
embankment and the slack of the stream is reduced. Hence the current, at
first accelerated by confinement, is afterwards checked by the mechanical
resistance of the matter deposited, and by the diminished inclination of its
channel, and then begins again to let fall the earth it holds in suspension,
and to raise its bed at the point where its overflow had been before
prevented by embankment. [Footnote: In proportion as the dikes are
improved, and breaches and the escape of the water through them are less
frequent, the height of the annual inundations is increased. Some towns on
the banks of the Po, and of course within the system of parallel
embankments, were formerly secure from flood by the height of the
artificial mounds on which they were built; but they have recently been
obliged to construct ring-dikes for their protection.
Lombardini lays down the following general statement of the effects of
river embankments:
"The immediate effect of embanking a river is generally an increase in
the height of its floods, but, at the same time, a depression of its bed, by
Page 626
reason of the increased force, and consequently excavating action, of the
current.
"It is true that coarser material may hence be carried further, and at the
same time deposit itself on a reduced slope.
"The embankment of the upper branches of a river increases the volume,
and therefore the height of the floods in the lower course, in consequence of
the more rapid discharge of its affluents into it.
"When, in consequence of the flow of a river channel through an alluvial
soil not yet REGULATED, or, in other words, which has not acquired its
normal inclination, the course of the river has not become established, it is
natural that its bed should rise more rapidly after its embankment. …
"The embankment of the lower course of a river, near its discharge into
the sea, causes the elevation of the bed of the next reach above, both
because the swelling of the current, in consequence of its lateral
confinement, occasions eddies, and of course deposits, and because the
prolongation of the course of the stream, or the advance of its delta into the
sea, is accelerated."—Dei congiamenti cia soggiacque l'idraulica condizione
del Po, etc., pp. 41, 42.
Del Noce states that in the levellings for the proposed Leopolda railway,
he found that the bed of the Sieue had been permanently elevated two yards
between 1708 and 1844, and that of the Fosso di San Gaudenzio more than
a yard and a half between 1752 and 1845. Those, indeed, are not rivers of
the rank of the Po; but neither are they what are technically called torrents
or mountain streams, whose flow is only an occasional effect of heavy rains
or melting snow.—Trattato delle Macchie e Foreste di Tuscana, Firenze,
1857, p. 29.] The bank must now be raised in proportion, and these
processes would be repeated and repeated indefinitely, had not nature
current.
"It is true that coarser material may hence be carried further, and at the
same time deposit itself on a reduced slope.
"The embankment of the upper branches of a river increases the volume,
and therefore the height of the floods in the lower course, in consequence of
the more rapid discharge of its affluents into it.
"When, in consequence of the flow of a river channel through an alluvial
soil not yet REGULATED, or, in other words, which has not acquired its
normal inclination, the course of the river has not become established, it is
natural that its bed should rise more rapidly after its embankment. …
"The embankment of the lower course of a river, near its discharge into
the sea, causes the elevation of the bed of the next reach above, both
because the swelling of the current, in consequence of its lateral
confinement, occasions eddies, and of course deposits, and because the
prolongation of the course of the stream, or the advance of its delta into the
sea, is accelerated."—Dei congiamenti cia soggiacque l'idraulica condizione
del Po, etc., pp. 41, 42.
Del Noce states that in the levellings for the proposed Leopolda railway,
he found that the bed of the Sieue had been permanently elevated two yards
between 1708 and 1844, and that of the Fosso di San Gaudenzio more than
a yard and a half between 1752 and 1845. Those, indeed, are not rivers of
the rank of the Po; but neither are they what are technically called torrents
or mountain streams, whose flow is only an occasional effect of heavy rains
or melting snow.—Trattato delle Macchie e Foreste di Tuscana, Firenze,
1857, p. 29.] The bank must now be raised in proportion, and these
processes would be repeated and repeated indefinitely, had not nature
Page 627
provided a remedy in floods, which sweep out recent deposits, burst the
bonds of the river and overwhelm the adjacent country with final
desolation, or divert the current into a new channel, destined to become, in
its turn, the scene of a similar struggle between man and the waters.
[Footnote: The Noang-ho has repeatedly burst its dikes and changed the
channel of its lower course, sometimes delivering its waters into the sea to
the north, sometimes to the south of the peninsula of Chan-tung, thus
varying its point of discharge by a distance of 220 miles.—Elisee Reclus,
La Terre, t. i, p. 477.
Sec interesting notices of the lower course of the Noang-ho in Nature,
Nov. 25, 1869.
The frequent changes of channel and mouth in the deltas of great rivers
are by no means always an effect of diking. The mere accumulation of
deposits in the beds of rivers which transport much sediment compels them
continually to seek new outlets, and it is only by great effort that art can
keep their points of discharge pproximately constant. The common delta of
the Ganges and the Brahmapootra is in a state of incessant change, and the
latter river is said to have shifted its main channel 200 miles to the west
since 1785, the revolution having been principally accomplished between
1810 and 1830.]
But here, as in so many other fields where nature is brought into conflict
with man, she first resists his attempts at interference with her operations,
then, finding him the stronger, quietly submits to his rule, and ends by
contributing her aid to strengthen the walls and shackles by which he essays
to confine her. If, by assiduous repair of his dikes, he, for a considerable
time, restrains the floods of a river within new bounds, nature, by a series of
ingenious compensations, brings the fluctuating bed of the stream to a
substantially constant level, and when his ramparts have been, by his toil,
bonds of the river and overwhelm the adjacent country with final
desolation, or divert the current into a new channel, destined to become, in
its turn, the scene of a similar struggle between man and the waters.
[Footnote: The Noang-ho has repeatedly burst its dikes and changed the
channel of its lower course, sometimes delivering its waters into the sea to
the north, sometimes to the south of the peninsula of Chan-tung, thus
varying its point of discharge by a distance of 220 miles.—Elisee Reclus,
La Terre, t. i, p. 477.
Sec interesting notices of the lower course of the Noang-ho in Nature,
Nov. 25, 1869.
The frequent changes of channel and mouth in the deltas of great rivers
are by no means always an effect of diking. The mere accumulation of
deposits in the beds of rivers which transport much sediment compels them
continually to seek new outlets, and it is only by great effort that art can
keep their points of discharge pproximately constant. The common delta of
the Ganges and the Brahmapootra is in a state of incessant change, and the
latter river is said to have shifted its main channel 200 miles to the west
since 1785, the revolution having been principally accomplished between
1810 and 1830.]
But here, as in so many other fields where nature is brought into conflict
with man, she first resists his attempts at interference with her operations,
then, finding him the stronger, quietly submits to his rule, and ends by
contributing her aid to strengthen the walls and shackles by which he essays
to confine her. If, by assiduous repair of his dikes, he, for a considerable
time, restrains the floods of a river within new bounds, nature, by a series of
ingenious compensations, brings the fluctuating bed of the stream to a
substantially constant level, and when his ramparts have been, by his toil,
Page 628
raised to a certain height and widened to a certain thickness, she, by her
laws of gravitation and cohesion, consolidates their material until it
becomes almost as hard, as indissoluble, and as impervious as the rock.
But, though man may press the forces of nature into his service, there is a
limit to the extent of his dominion over them, and unless future generations
shall discover new modes of controlling those forces, or new remedies
against their action, he must at last succumb in the struggle. When the
marine estuaries and other basins of reception shall be filled up with the
sedimentary debris of the mountains, or when the lower course of the rivers
shall be raised or prolonged by their own deposits until they have, no
longer, such a descent that gravitation and the momentum of the current can
overcome the frictional resistance of the bed and banks, the water will, in
spite of all obstacles, diffuse itself laterally and for a time raise the level of
the champaign land upon its borders, and at last convert it into morasses. It
is for this reason that Lombardini advises that a considerable space along
the lower course of rivers be left undiked, and the water allowed to spread
itself over its banks and gradually raise them by its deposits. [Footnote:
This method has been adopted on the lower course of the Lamone, and a
considerable extent of low ground adjacent to that river has been raised by
spontaneous deposit to a sufficient height to admit of profitable cultivation.]
This would, indeed, be a palliative, but only a palliative. For the present,
however, we have nothing better, and here, as often in political economy,
we must content ourselves with "apres nous le deluge," allowing posterity
to suffer the penalty of our improvidence and our ignorance, or to devise
means for itself to ward off the consequences of them.
The deposit of slime by rivers upon the flats along their banks not only
contributes greatly to the fertility of the soil thus flowed, but it subserves a
still more important purpose in the general economy of nature. All running
streams begin with excavating channels for themselves, or deepening the
laws of gravitation and cohesion, consolidates their material until it
becomes almost as hard, as indissoluble, and as impervious as the rock.
But, though man may press the forces of nature into his service, there is a
limit to the extent of his dominion over them, and unless future generations
shall discover new modes of controlling those forces, or new remedies
against their action, he must at last succumb in the struggle. When the
marine estuaries and other basins of reception shall be filled up with the
sedimentary debris of the mountains, or when the lower course of the rivers
shall be raised or prolonged by their own deposits until they have, no
longer, such a descent that gravitation and the momentum of the current can
overcome the frictional resistance of the bed and banks, the water will, in
spite of all obstacles, diffuse itself laterally and for a time raise the level of
the champaign land upon its borders, and at last convert it into morasses. It
is for this reason that Lombardini advises that a considerable space along
the lower course of rivers be left undiked, and the water allowed to spread
itself over its banks and gradually raise them by its deposits. [Footnote:
This method has been adopted on the lower course of the Lamone, and a
considerable extent of low ground adjacent to that river has been raised by
spontaneous deposit to a sufficient height to admit of profitable cultivation.]
This would, indeed, be a palliative, but only a palliative. For the present,
however, we have nothing better, and here, as often in political economy,
we must content ourselves with "apres nous le deluge," allowing posterity
to suffer the penalty of our improvidence and our ignorance, or to devise
means for itself to ward off the consequences of them.
The deposit of slime by rivers upon the flats along their banks not only
contributes greatly to the fertility of the soil thus flowed, but it subserves a
still more important purpose in the general economy of nature. All running
streams begin with excavating channels for themselves, or deepening the
Page 629
natural depressions in which they flow; [Footnote: I do not mean to say that
all rivers excavate their own valleys, for I have no doubt that in the majority
of cases such depressions of the surface originate in higher geological
causes, such as the fissures and other irregularities of surface which could
not fail to accompany upheaval, and hence the valley makes the river, not
the river the valley. But even if we suppose a basin of the hardest rock to be
elevated at once, completely formed, from the submarine abyss where it
was fashioned, the first shower of rain that falls upon it, after it rises to the
air, will discharge its waters along the lowest lines of the surface, and cut
those lines deeper, and so on with every successive rain. The disintegrated
rock from the upper part of the basin forms the lower by alluvial deposit,
which is constantly transported farther and farther until the resistance of
gravitation and cohesion balances the mechanical force of the running
water. Thus plains, more or less steeply inclined, are formed, in which the
river is constantly changing its bed, according to the perpetually varying
force and direction of its currents, modified as they are by ever-fluctuating
conditions. Thus the Po is said to have long inclined to move its channel
southwards, at certain points, in consequence of the mechanical force of its
northern affluents. A diversion of these tributaries from their present beds,
so that they should enter the main stream at other points and in different
directions, might modify the whole course of that great river. But the
mechanical force of the tributary is not the only element of its influence on
the course of the principal stream. The deposits it lodges in the bed of the
latter, acting as simple obstructions or causes of diversion, are not less
important agents of change.] but in proportion as their outlets are raised by
the solid material transported by their currents, their velocity is diminished,
they deposit gravel and sand at constantly higher and higher points, and so
at last elevate, in the middle and lower part of their course, the beds they
had previously scooped out. [Footnote: The distance to which a new
obstruction to the flow of a river, whether by a dam or by a deposit in its
all rivers excavate their own valleys, for I have no doubt that in the majority
of cases such depressions of the surface originate in higher geological
causes, such as the fissures and other irregularities of surface which could
not fail to accompany upheaval, and hence the valley makes the river, not
the river the valley. But even if we suppose a basin of the hardest rock to be
elevated at once, completely formed, from the submarine abyss where it
was fashioned, the first shower of rain that falls upon it, after it rises to the
air, will discharge its waters along the lowest lines of the surface, and cut
those lines deeper, and so on with every successive rain. The disintegrated
rock from the upper part of the basin forms the lower by alluvial deposit,
which is constantly transported farther and farther until the resistance of
gravitation and cohesion balances the mechanical force of the running
water. Thus plains, more or less steeply inclined, are formed, in which the
river is constantly changing its bed, according to the perpetually varying
force and direction of its currents, modified as they are by ever-fluctuating
conditions. Thus the Po is said to have long inclined to move its channel
southwards, at certain points, in consequence of the mechanical force of its
northern affluents. A diversion of these tributaries from their present beds,
so that they should enter the main stream at other points and in different
directions, might modify the whole course of that great river. But the
mechanical force of the tributary is not the only element of its influence on
the course of the principal stream. The deposits it lodges in the bed of the
latter, acting as simple obstructions or causes of diversion, are not less
important agents of change.] but in proportion as their outlets are raised by
the solid material transported by their currents, their velocity is diminished,
they deposit gravel and sand at constantly higher and higher points, and so
at last elevate, in the middle and lower part of their course, the beds they
had previously scooped out. [Footnote: The distance to which a new
obstruction to the flow of a river, whether by a dam or by a deposit in its
Page 630
channel, will retard its current, or, in popular phrase, "set back the water," is
a problem of more difficult practical solution than almost any other in
hydraulics. The elements—such as straightness or crookedness of channel,
character of bottom and banks, volume and previous velocity of current,
mass of water far above the obstruction, extraordinary drought or humidity
of seasons, relative extent to which the river may be affected by the
precipitation in its own basin, and by supplies received through
subterranean channels from sources so distant as to be exposed to very
different meteorological influences, effects of clearing and other
improvements always going on in new countries—are all extremely
difficult, and some of them impossible, to be known and measured. In the
American States, very numerous water-mills have been erected within a few
years, and there is scarcely a stream in the settled portion of the country
which has not several mill-dams upon it. When a dam is raised—a process
which the gradual diminution of the summer currents renders frequently
necessary—or when a new dam is built, it often happens that the meadows
above are flowed, or that the retardation of the stream extends back to the
dam next above. This leads to frequent law-suits. From the great uncertainty
of the facts, the testimony is more conflicting in these than in any other
class of cases, and the obstinacy with which "water causes" are disputed has
become proverbial.] The raising of the channels is compensated in part by
the simultaneous elevation of their banks and the flats adjoining them, from
the deposit of the finer particles of earth and vegetable mould brought down
from the mountains, without which elevation the low grounds bordering all
rivers would be, as in many cases they in fact are, mere morasses.
All arrangements which tend to obstruct this process of raising the flats
adjacent to the channel, whether consisting in dikes which confine the
waters, and, at the same time, augment the velocity of the current, or in
other means of producing the last-mentioned effect, interfere with the
restorative economy of nature, and at last occasion the formation of
a problem of more difficult practical solution than almost any other in
hydraulics. The elements—such as straightness or crookedness of channel,
character of bottom and banks, volume and previous velocity of current,
mass of water far above the obstruction, extraordinary drought or humidity
of seasons, relative extent to which the river may be affected by the
precipitation in its own basin, and by supplies received through
subterranean channels from sources so distant as to be exposed to very
different meteorological influences, effects of clearing and other
improvements always going on in new countries—are all extremely
difficult, and some of them impossible, to be known and measured. In the
American States, very numerous water-mills have been erected within a few
years, and there is scarcely a stream in the settled portion of the country
which has not several mill-dams upon it. When a dam is raised—a process
which the gradual diminution of the summer currents renders frequently
necessary—or when a new dam is built, it often happens that the meadows
above are flowed, or that the retardation of the stream extends back to the
dam next above. This leads to frequent law-suits. From the great uncertainty
of the facts, the testimony is more conflicting in these than in any other
class of cases, and the obstinacy with which "water causes" are disputed has
become proverbial.] The raising of the channels is compensated in part by
the simultaneous elevation of their banks and the flats adjoining them, from
the deposit of the finer particles of earth and vegetable mould brought down
from the mountains, without which elevation the low grounds bordering all
rivers would be, as in many cases they in fact are, mere morasses.
All arrangements which tend to obstruct this process of raising the flats
adjacent to the channel, whether consisting in dikes which confine the
waters, and, at the same time, augment the velocity of the current, or in
other means of producing the last-mentioned effect, interfere with the
restorative economy of nature, and at last occasion the formation of
Page 631
marshes where, if left to herself, she might have accumulated inexhaustible
stores of the richest soil, and spread them out in plains above the reach of
ordinary floods. [Footnote: The sediment of the Po has filled up some
lagoons and swamps in its delta, and converted them into comparatively dry
land; but, on the other hand, the retardation of the current from the
lengthening of its course, and the diminution of its velocity by the deposits
at its mouth, have forced its waters at some higher points to spread in spite
of embankments, and thus fertile fields have been turned into unhealthy and
unproductive marshes.—See Botter, Sulla condizione dei Terreni
Maremmani nel Ferraress. Annali di Agricoltura, etc., Fasc. v., 1863.]
Dikes, which, as we have seen, are the means most frequently employed
to prevent damage by inundation, are generally parallel to each other and
separated by a distance not very much greater than the natural width of the
bed. [Footnote: In the case of rivers flowing through wide alluvial plains
and much inclined to shift their beds, like the Po, the embankments often
leave a very wide space between them. The dikes of the Po are sometimes
three or four miles apart.] If such walls are high enough to confine the water
and strong enough to resist its pressure, they secure the lands behind them
from all the evils of inundation except those resulting from filtration; but
such ramparts are enormously costly in original construction and in
maintenance, and, as has been already shown, the filling up of the bed of
the river in its lower course, by sand and gravel, often involves the
necessity of incurring new expenditures in increasing the height of the
banks. [Footnote: It appears from the investigations of Lombardini that the
rate of elevation of the bed of the Po has been much exaggerated by earlier
writers, and in some parts of its course the change is so slow that its level
may be regarded as nearly constant. Observation has established a similar
constancy in the bed of the Rhone and of many other important rivers,
while, on the other hand, the beds of the Adige and the Brenta, streams of a
stores of the richest soil, and spread them out in plains above the reach of
ordinary floods. [Footnote: The sediment of the Po has filled up some
lagoons and swamps in its delta, and converted them into comparatively dry
land; but, on the other hand, the retardation of the current from the
lengthening of its course, and the diminution of its velocity by the deposits
at its mouth, have forced its waters at some higher points to spread in spite
of embankments, and thus fertile fields have been turned into unhealthy and
unproductive marshes.—See Botter, Sulla condizione dei Terreni
Maremmani nel Ferraress. Annali di Agricoltura, etc., Fasc. v., 1863.]
Dikes, which, as we have seen, are the means most frequently employed
to prevent damage by inundation, are generally parallel to each other and
separated by a distance not very much greater than the natural width of the
bed. [Footnote: In the case of rivers flowing through wide alluvial plains
and much inclined to shift their beds, like the Po, the embankments often
leave a very wide space between them. The dikes of the Po are sometimes
three or four miles apart.] If such walls are high enough to confine the water
and strong enough to resist its pressure, they secure the lands behind them
from all the evils of inundation except those resulting from filtration; but
such ramparts are enormously costly in original construction and in
maintenance, and, as has been already shown, the filling up of the bed of
the river in its lower course, by sand and gravel, often involves the
necessity of incurring new expenditures in increasing the height of the
banks. [Footnote: It appears from the investigations of Lombardini that the
rate of elevation of the bed of the Po has been much exaggerated by earlier
writers, and in some parts of its course the change is so slow that its level
may be regarded as nearly constant. Observation has established a similar
constancy in the bed of the Rhone and of many other important rivers,
while, on the other hand, the beds of the Adige and the Brenta, streams of a
Page 632
more torrential character, are raised considerably above the level of the
adjacent fields.
The length of the lower course of the Po having been considerably
increased by the filling up of the Adriatic with its deposits, the velocity of
the current ought, prima facie, to have been diminished and its bed raised in
proportion. There are abundant grounds for believing that this has happened
in the case of the Nile, and one reason why the same effect has not been
more sensibly perceptible in the Po is, that the confinement of the current
by continuous embankements gives it a high-water velocity sufficient to
sweep out deposits let fall at lower stages and slower movements of the
water. Torrential streams tend to excavate or to raise their beds according to
the inclination, and to the character of the material they transport. No
general law on this point can be laid down in relation to the middle and
lower courses of rivers. The conditions which determine the question of the
depression or elevation of a river-bed are too multifarious, variable, and
complex, to be subjected to formulae, and they can scarcely even be
enumerated.
The following observation, however, though apparently too
unconditionally stated, is too important to be omitted.
Rivers which transport sand, gravel, pebbles, heavy mineral matter in
short, tend to raise their own beds; those charged only with fine, light earth,
to cut them deeper. The prairie rivers of the western United States have
deep channels, because the mineral matter they carry down is not heavy
enough to resist the impulse of even a moderate current, and those
tributaries of the Po which deposit their sediment in the lakes—the Ticino,
the Adda, the Oglio, and the Mincio—flow in deep cuts, for the same
reason.—Baumgarten, p. 132.
adjacent fields.
The length of the lower course of the Po having been considerably
increased by the filling up of the Adriatic with its deposits, the velocity of
the current ought, prima facie, to have been diminished and its bed raised in
proportion. There are abundant grounds for believing that this has happened
in the case of the Nile, and one reason why the same effect has not been
more sensibly perceptible in the Po is, that the confinement of the current
by continuous embankements gives it a high-water velocity sufficient to
sweep out deposits let fall at lower stages and slower movements of the
water. Torrential streams tend to excavate or to raise their beds according to
the inclination, and to the character of the material they transport. No
general law on this point can be laid down in relation to the middle and
lower courses of rivers. The conditions which determine the question of the
depression or elevation of a river-bed are too multifarious, variable, and
complex, to be subjected to formulae, and they can scarcely even be
enumerated.
The following observation, however, though apparently too
unconditionally stated, is too important to be omitted.
Rivers which transport sand, gravel, pebbles, heavy mineral matter in
short, tend to raise their own beds; those charged only with fine, light earth,
to cut them deeper. The prairie rivers of the western United States have
deep channels, because the mineral matter they carry down is not heavy
enough to resist the impulse of even a moderate current, and those
tributaries of the Po which deposit their sediment in the lakes—the Ticino,
the Adda, the Oglio, and the Mincio—flow in deep cuts, for the same
reason.—Baumgarten, p. 132.
Page 633
In regard to the level of the bed of the Po, there is another weighty
consideration which does not seem to have received the attention it
deserves. refer to the secular depression of the western coast of the Adriatic,
which is computed at the rate of fifteen or twenty centimetres in a century,
and which of course increases the inclination of the bed, and the velocity
and transporting power of the current of the Po, UNLESS we assume that
the whole course of the river, from the sea to its sources, shares in the
depression. Of this assumption there is no proof, and the probability is to
the contrary. For the evidence, though not conclusive, perhaps, tends to
show an elevation of the Tuscan coast, and even of the Ligurian shore at
points lying farther west than the sources of the Po. The level of certain
parts of the bed of the river referred to by Lombardini as constant, is not
their elevation as compared with points nearer the sea, but relatively to the
adjacent plains, and there is every reason to believe that the depression of
the Adriatic coast, whether, as is conceivable, occasioned by the mere
weight of the fluviatile deposits or by more general geological causes, has
increased the slope of the bed of the river between the points in question
and the sea. In this instance, then, the relative permanency of the river level
at certain points may be, not the ordinary case of a natural equilibrium, but
the negative effect of an increased velocity of current which prevents
deposits where they would otherwise have happened.] They are attended,
too, with some collateral disadvantages. They deprive the earth of the
fertilizing deposits of the waters, which are powerful natural restoratives of
soils exhausted by cultivation; they accelerate the rapidity and transporting
power of the current at high water by confining it to a narrower channel,
and it consequently conveys to the sea the earthy matter it holds in
suspension, and chokes up harbors with a deposit which it would otherwise
have spread over a wider surface; they interfere with roads and the
convenience of river navigation, and no amount of cost or care can secure
them from occasional rupture, in case of which the rush of the waters
consideration which does not seem to have received the attention it
deserves. refer to the secular depression of the western coast of the Adriatic,
which is computed at the rate of fifteen or twenty centimetres in a century,
and which of course increases the inclination of the bed, and the velocity
and transporting power of the current of the Po, UNLESS we assume that
the whole course of the river, from the sea to its sources, shares in the
depression. Of this assumption there is no proof, and the probability is to
the contrary. For the evidence, though not conclusive, perhaps, tends to
show an elevation of the Tuscan coast, and even of the Ligurian shore at
points lying farther west than the sources of the Po. The level of certain
parts of the bed of the river referred to by Lombardini as constant, is not
their elevation as compared with points nearer the sea, but relatively to the
adjacent plains, and there is every reason to believe that the depression of
the Adriatic coast, whether, as is conceivable, occasioned by the mere
weight of the fluviatile deposits or by more general geological causes, has
increased the slope of the bed of the river between the points in question
and the sea. In this instance, then, the relative permanency of the river level
at certain points may be, not the ordinary case of a natural equilibrium, but
the negative effect of an increased velocity of current which prevents
deposits where they would otherwise have happened.] They are attended,
too, with some collateral disadvantages. They deprive the earth of the
fertilizing deposits of the waters, which are powerful natural restoratives of
soils exhausted by cultivation; they accelerate the rapidity and transporting
power of the current at high water by confining it to a narrower channel,
and it consequently conveys to the sea the earthy matter it holds in
suspension, and chokes up harbors with a deposit which it would otherwise
have spread over a wider surface; they interfere with roads and the
convenience of river navigation, and no amount of cost or care can secure
them from occasional rupture, in case of which the rush of the waters
Page 634
through the breach is more destructive than the natural flow of the highest
inundation. [Footnote: To secure the city of Sacramento, in California, from
the inundations to which it is subject, a dike or levee was built upon the
bank of the river and raised to an elevation above that of the highest known
floods, and it was connected, below the town, with grounds lying
considerably above the river. On one occasion a breach in the dike occurred
above the town at a very high stage of the flood. The water poured in
behind it, and overflowed the lower part of the city, which remained
submerged for some time after the river had retired to its ordinary level,
because the dike, which had been built to keep the water OUT, now kept it
IN.
According to Arthur Young, on the lower Po, where the surface of the
river at high water has been elevated considerably above the level of the
adjacent fields by diking, the peasants in his time frequently endeavored to
secure their grounds against threatened devastation through the bursting of
the dikes, by crossing the river when the danger became imminent and
opening a cut in the opposite bank, thus saving their own property by
flooding their neighbors'. He adds, that at high water the navigation of the
river was absolutely interdicted, except to mail and passenger boats, and
that the guards fired upon all others; the object of the prohibition being to
prevent the peasants from resorting to this measure of self-defence.—
Travels in Italy and Spain, Nov. 7, 1789.
In a flood of the Po in 1839, a breach of the embankment took place at
Bonizzo. The water poured through and inundated 116,000 acres, or 181
square miles, of the plain to the depth of from twenty to twenty-three feet,
in the lower parts. The inundation of May, 1872, a giant breach occurred in
the dike near Ferrara, and 170,000 acres of cultivated land were
overflowed, and a population of 30,000 souls driven from their homes. In
the flood of October in the same year, in consequence of a breach of the
inundation. [Footnote: To secure the city of Sacramento, in California, from
the inundations to which it is subject, a dike or levee was built upon the
bank of the river and raised to an elevation above that of the highest known
floods, and it was connected, below the town, with grounds lying
considerably above the river. On one occasion a breach in the dike occurred
above the town at a very high stage of the flood. The water poured in
behind it, and overflowed the lower part of the city, which remained
submerged for some time after the river had retired to its ordinary level,
because the dike, which had been built to keep the water OUT, now kept it
IN.
According to Arthur Young, on the lower Po, where the surface of the
river at high water has been elevated considerably above the level of the
adjacent fields by diking, the peasants in his time frequently endeavored to
secure their grounds against threatened devastation through the bursting of
the dikes, by crossing the river when the danger became imminent and
opening a cut in the opposite bank, thus saving their own property by
flooding their neighbors'. He adds, that at high water the navigation of the
river was absolutely interdicted, except to mail and passenger boats, and
that the guards fired upon all others; the object of the prohibition being to
prevent the peasants from resorting to this measure of self-defence.—
Travels in Italy and Spain, Nov. 7, 1789.
In a flood of the Po in 1839, a breach of the embankment took place at
Bonizzo. The water poured through and inundated 116,000 acres, or 181
square miles, of the plain to the depth of from twenty to twenty-three feet,
in the lower parts. The inundation of May, 1872, a giant breach occurred in
the dike near Ferrara, and 170,000 acres of cultivated land were
overflowed, and a population of 30,000 souls driven from their homes. In
the flood of October in the same year, in consequence of a breach of the
Page 635
dike at Revere, 250,000 acres of cultivated soil were overflowed, and
60,000 persons were made homeless. The dikes were seriously injured at
more than forty points. See page 279, ante. In the flood of 1856, the Loire
made seventy-three breaches in its dikes, and thus, instead of a
comparatively gradual rise and gentle expansion of its waters, it created
seventy-three impetuous torrents, which inflicted infinitely greater mischief
than a simply natural overflow would have done. The dikes or levees of the
Mississippi, being of more recent construction than those of the Po, are not
yet well consolidated and fortified, and for this reason crevasses which
occasion destructive inundations are of very frequent occurrence.]
For these reasons, many experienced engineers are of opinion that the
system of longitudinal dikes is fundamentally wrong, and it has been argued
that if the Po, the Adige, and the Brenta had been left unconfined, as the
Nile formerly was, and allowed to spread their muddy waters at will,
according to the laws of nature, the sediment they have carried to the coast
would have been chiefly distributed over the plains of Lombardy. Their
banks, it is supposed, would have risen as fast as their beds, the coast-line
would not have been extended so far into the Adriatic, and, the current of
the streams being consequently shorter, the inclination of their channel and
the rapidity of their flow would not have been so greatly diminished. Had
man, too, spared a reasonable proportion of the forests of the Alps, and not
attempted to control the natural drainage of the surface, the Po, it has been
said, would resemble the Nile in all its essential characteristics, and, in spite
of the difference of climate, perhaps be regarded as the friend and ally, not
the enemy and the invader, of the population which dwells upon its banks.
But it has been shown by Humphreys and Abbot that the system of
longitudinal dikes is the only one susceptible of advantageous application to
the Mississippi, and if we knew the primitive geography and hydrography
of the basin of the Po as well as wo do those of the valley of the great
60,000 persons were made homeless. The dikes were seriously injured at
more than forty points. See page 279, ante. In the flood of 1856, the Loire
made seventy-three breaches in its dikes, and thus, instead of a
comparatively gradual rise and gentle expansion of its waters, it created
seventy-three impetuous torrents, which inflicted infinitely greater mischief
than a simply natural overflow would have done. The dikes or levees of the
Mississippi, being of more recent construction than those of the Po, are not
yet well consolidated and fortified, and for this reason crevasses which
occasion destructive inundations are of very frequent occurrence.]
For these reasons, many experienced engineers are of opinion that the
system of longitudinal dikes is fundamentally wrong, and it has been argued
that if the Po, the Adige, and the Brenta had been left unconfined, as the
Nile formerly was, and allowed to spread their muddy waters at will,
according to the laws of nature, the sediment they have carried to the coast
would have been chiefly distributed over the plains of Lombardy. Their
banks, it is supposed, would have risen as fast as their beds, the coast-line
would not have been extended so far into the Adriatic, and, the current of
the streams being consequently shorter, the inclination of their channel and
the rapidity of their flow would not have been so greatly diminished. Had
man, too, spared a reasonable proportion of the forests of the Alps, and not
attempted to control the natural drainage of the surface, the Po, it has been
said, would resemble the Nile in all its essential characteristics, and, in spite
of the difference of climate, perhaps be regarded as the friend and ally, not
the enemy and the invader, of the population which dwells upon its banks.
But it has been shown by Humphreys and Abbot that the system of
longitudinal dikes is the only one susceptible of advantageous application to
the Mississippi, and if we knew the primitive geography and hydrography
of the basin of the Po as well as wo do those of the valley of the great
Page 636
American river, we should very probably find that the condemnation of the
plan pursued by the ancient inhabitants of Lombardy is a too hasty
generalization, and that the case of the Nile is an exception, not an example
of the normal regime and condition of a great river. [Footnote:
Embankments have been employed on the lower course of the Po for at
least two thousand years, and for some centuries they have been connected
in a continuous chain from the sea to the vicinity of Cremona. From early
ages the Italian hydrographers have stood in the front rank of their
profession, and the Italian literature of this branch of material improvement
is exceedingly voluminous, exhaustive, and complete.
"The science of rivers after the barbarous ages," says Mengotti, "may be
said to have been born and perfected in Italy." The eminent Italian engineer
Lombardini published in 1870, under the title of Guida allo studio dell'
idrologia fluviale e dell' Idraulica practica, which serves both as a summary
of the recent progress of that science and as an index to the literature of the
subject. The professional student, therefore, as well as the geographer, will
have very frequent occasion to consult Italian authorities, and in the very
valuable Report of Humphreys and Abbot on the Mississippi, America has
lately made a contribution to our potamological knowledge, which, in
scientific interest and practical utility, does not fall short of the ablest
European productions in the same branch of inquiry.]
But in any event, these theoretical objections are counsels apres coup.
The dikes of the Po and probably of some of its tributaries were begun
before we have any trustworthy physical or political annals of the provinces
they water. The civilization of the valley has accommodated itself to these
arrangements, and the interests which might be sacrificed by a change of
system are too vast to be hazarded by what, in the present state of our
knowledge, can be only considered as a doubtful experiment. [Footnote:
Dupenchel advised a resort to the "heroic remedy" of sacrificing, or
plan pursued by the ancient inhabitants of Lombardy is a too hasty
generalization, and that the case of the Nile is an exception, not an example
of the normal regime and condition of a great river. [Footnote:
Embankments have been employed on the lower course of the Po for at
least two thousand years, and for some centuries they have been connected
in a continuous chain from the sea to the vicinity of Cremona. From early
ages the Italian hydrographers have stood in the front rank of their
profession, and the Italian literature of this branch of material improvement
is exceedingly voluminous, exhaustive, and complete.
"The science of rivers after the barbarous ages," says Mengotti, "may be
said to have been born and perfected in Italy." The eminent Italian engineer
Lombardini published in 1870, under the title of Guida allo studio dell'
idrologia fluviale e dell' Idraulica practica, which serves both as a summary
of the recent progress of that science and as an index to the literature of the
subject. The professional student, therefore, as well as the geographer, will
have very frequent occasion to consult Italian authorities, and in the very
valuable Report of Humphreys and Abbot on the Mississippi, America has
lately made a contribution to our potamological knowledge, which, in
scientific interest and practical utility, does not fall short of the ablest
European productions in the same branch of inquiry.]
But in any event, these theoretical objections are counsels apres coup.
The dikes of the Po and probably of some of its tributaries were begun
before we have any trustworthy physical or political annals of the provinces
they water. The civilization of the valley has accommodated itself to these
arrangements, and the interests which might be sacrificed by a change of
system are too vast to be hazarded by what, in the present state of our
knowledge, can be only considered as a doubtful experiment. [Footnote:
Dupenchel advised a resort to the "heroic remedy" of sacrificing, or
Page 637
converting into cellars, the lower storeys of houses in cities exposed to river
inundation, filling up the streets, and admitting the water of floods freely
over the adjacent country, and thus allowing it to raise the level of the soil
to that of the highest inundations.—Traite d'Hydraulique et de Geologie
Agricole, Paris, 1868, p. 241.]
The embankments of the Po, though they are of vast extent and have
employed centuries in their construction, are inferior in magnitude to the
dikes or levees of the Mississippi, which are the work of scarcely a hundred
years, and of a comparatively sparse population. On the right or western
bank of the river, the levee extends, with only occasional interruptions from
high bluffs and the mouths of rivers, for a distance of more than eleven
hundred miles. The left bank is, in general, higher than the right, and upon
that side a continuous embankment is not needed; but the total length of the
dikes of the Mississippi, including those of the lower course of its
tributaries and of its bayous or natural emissaries, is not less than 2,500
miles. They constitute, therefore, not only one of the greatest material
achievements of the American people, but one of the most remarkable
systems of physical improvement which has been anywhere accomplished
in modern times.
Those who condemn the system of longitudinal embankments have often
advised that, in cases where that system cannot be abandoned without
involving too great a sacrifice of existing interests, the elevation of the
dikes should be much reduced, so as to present no obstruction to the lateral
spread of extraordinary floods, and that they should be provided with
sluices to admit the water without violence whenever they are likely to be
overflowed. Where dikes have not been erected, or where they have been
reduced in height, it is proposed to construct, at convenient intervals,
transverse embankments of moderate height running from the banks of the
river across the plains to the hills which bound them. These measures, it is
inundation, filling up the streets, and admitting the water of floods freely
over the adjacent country, and thus allowing it to raise the level of the soil
to that of the highest inundations.—Traite d'Hydraulique et de Geologie
Agricole, Paris, 1868, p. 241.]
The embankments of the Po, though they are of vast extent and have
employed centuries in their construction, are inferior in magnitude to the
dikes or levees of the Mississippi, which are the work of scarcely a hundred
years, and of a comparatively sparse population. On the right or western
bank of the river, the levee extends, with only occasional interruptions from
high bluffs and the mouths of rivers, for a distance of more than eleven
hundred miles. The left bank is, in general, higher than the right, and upon
that side a continuous embankment is not needed; but the total length of the
dikes of the Mississippi, including those of the lower course of its
tributaries and of its bayous or natural emissaries, is not less than 2,500
miles. They constitute, therefore, not only one of the greatest material
achievements of the American people, but one of the most remarkable
systems of physical improvement which has been anywhere accomplished
in modern times.
Those who condemn the system of longitudinal embankments have often
advised that, in cases where that system cannot be abandoned without
involving too great a sacrifice of existing interests, the elevation of the
dikes should be much reduced, so as to present no obstruction to the lateral
spread of extraordinary floods, and that they should be provided with
sluices to admit the water without violence whenever they are likely to be
overflowed. Where dikes have not been erected, or where they have been
reduced in height, it is proposed to construct, at convenient intervals,
transverse embankments of moderate height running from the banks of the
river across the plains to the hills which bound them. These measures, it is
Page 638
argued, will diminish the violence of inundations by permitting the waters
to extend themselves over a greater surface, and by thus retarding the flow
of the river currents, will, at the same time, secure the deposit of fertilizing
slime upon all the soil covered by the flood. [Footnote: The system
described in the text is substantially the Egyptian method, the ancient Nile
dikes having been constructed rather to retain than to exclude the water.]
Rozet, an eminent French engineer, has proposed a method of
diminishing the ravages of inundations, which aims to combine the
advantages of all other systems, and at the same time to obviate the
objections to which they are all more or less liable. [Footnote: Moyens de
forcer les Torrents de rendre une partie du sol qu'ils ravagent, et d'empecher
les grandes Inondations.] The plan of Rozet is recommended by its
simplicity and cheapness as well as its facility and rapidity of execution,
and is looked upon with favor by many persons very competent to judge in
such matters. It is, however, by no means capable of universal application,
though it would often doubtless prove highly useful in connection with the
measures now employed in South-eastern France. He proposes to
commence with the amphitheatres in which mountain torrents so often rise,
by covering their slopes and filling their beds with loose blocks of rock, and
by constructing at their outlets, and at other narrow points in the channels of
the torrents, permeable barriers of the same material promiscuously heaped
up, much according to the method employed by the ancient Romans in their
northern provinces for a similar purpose. By this means, he supposes, the
rapidity of the current would be checked, and the quantity of transported
pebbles and gravel—which, by increasing the mechanical force of the
water, greatly aggravate the damage by floods—much diminished. When
the stream has reached that part of its course where it is bordered by soil
capable of cultivation, and worth the expense of protection, he proposes to
place along one or both banks, according to circumstances, a line of cubical
blocks of stone or pillars of masonry three or four feet high and wide, and at
to extend themselves over a greater surface, and by thus retarding the flow
of the river currents, will, at the same time, secure the deposit of fertilizing
slime upon all the soil covered by the flood. [Footnote: The system
described in the text is substantially the Egyptian method, the ancient Nile
dikes having been constructed rather to retain than to exclude the water.]
Rozet, an eminent French engineer, has proposed a method of
diminishing the ravages of inundations, which aims to combine the
advantages of all other systems, and at the same time to obviate the
objections to which they are all more or less liable. [Footnote: Moyens de
forcer les Torrents de rendre une partie du sol qu'ils ravagent, et d'empecher
les grandes Inondations.] The plan of Rozet is recommended by its
simplicity and cheapness as well as its facility and rapidity of execution,
and is looked upon with favor by many persons very competent to judge in
such matters. It is, however, by no means capable of universal application,
though it would often doubtless prove highly useful in connection with the
measures now employed in South-eastern France. He proposes to
commence with the amphitheatres in which mountain torrents so often rise,
by covering their slopes and filling their beds with loose blocks of rock, and
by constructing at their outlets, and at other narrow points in the channels of
the torrents, permeable barriers of the same material promiscuously heaped
up, much according to the method employed by the ancient Romans in their
northern provinces for a similar purpose. By this means, he supposes, the
rapidity of the current would be checked, and the quantity of transported
pebbles and gravel—which, by increasing the mechanical force of the
water, greatly aggravate the damage by floods—much diminished. When
the stream has reached that part of its course where it is bordered by soil
capable of cultivation, and worth the expense of protection, he proposes to
place along one or both banks, according to circumstances, a line of cubical
blocks of stone or pillars of masonry three or four feet high and wide, and at
Page 639
the distance of about eleven yards from each other. The space between the
two lines, or between a line and the opposite high bank, would, of course,
be determined by observation of the width of the swift-water current at high
floods. As an auxiliary measure, small ditches and banks, or low walls of
pebbles, should be constructed from the line of blocks across the grounds to
be protected, nearly at right angles to the current, but slightly inclining
downwards, and at convenient distances from each other. Rozet thinks the
proper interval would be 300 yards, and it is evident that, if he is right in his
main principle, hedges, rows of trees, or even common fences, would in
many cases answer as good a purpose as banks and trenches or low walls.
The blocks or pillars of stone would, he contends, check the lateral currents
so as to compel them to let fall all their pebbles and gravel in the main
channel—where they would be rolled along until ground down to sand or
silt—and the transverse obstructions would detain the water upon the soil
long enough to secure the deposit of its fertilizing slime. Numerous facts
are cited in support of the author's views, and I imagine there are few
residents of rural districts whose own observation will not furnish testimony
confirmatory of their soundness. [Footnote: The effect of trees and other
detached obstructions in checking the flow of water is particularly noticed
by Palissy in his essay on Waters and Fountains, p. 173, edition of 1844.
"There be," says he, "in divers parts of France, and specially at Nantes,
wooden bridges, where, to break the force of the waters and of the floating
ice, which might endamage the piers of the said bridges, they have driven
upright timbers into the bed of the rivers above the said piers, without the
which they should abide but little. And in like wise, the trees which be
planted along the mountains do much deaden the violence of the waters that
flow from them."
Lombardini attaches great importance to the planting of rows of trees
transversely to the current on grounds subject to overflow.—Esame degli
Studi sul Tevere, Section 53, and Appendice, Sections 33, 34.]
two lines, or between a line and the opposite high bank, would, of course,
be determined by observation of the width of the swift-water current at high
floods. As an auxiliary measure, small ditches and banks, or low walls of
pebbles, should be constructed from the line of blocks across the grounds to
be protected, nearly at right angles to the current, but slightly inclining
downwards, and at convenient distances from each other. Rozet thinks the
proper interval would be 300 yards, and it is evident that, if he is right in his
main principle, hedges, rows of trees, or even common fences, would in
many cases answer as good a purpose as banks and trenches or low walls.
The blocks or pillars of stone would, he contends, check the lateral currents
so as to compel them to let fall all their pebbles and gravel in the main
channel—where they would be rolled along until ground down to sand or
silt—and the transverse obstructions would detain the water upon the soil
long enough to secure the deposit of its fertilizing slime. Numerous facts
are cited in support of the author's views, and I imagine there are few
residents of rural districts whose own observation will not furnish testimony
confirmatory of their soundness. [Footnote: The effect of trees and other
detached obstructions in checking the flow of water is particularly noticed
by Palissy in his essay on Waters and Fountains, p. 173, edition of 1844.
"There be," says he, "in divers parts of France, and specially at Nantes,
wooden bridges, where, to break the force of the waters and of the floating
ice, which might endamage the piers of the said bridges, they have driven
upright timbers into the bed of the rivers above the said piers, without the
which they should abide but little. And in like wise, the trees which be
planted along the mountains do much deaden the violence of the waters that
flow from them."
Lombardini attaches great importance to the planting of rows of trees
transversely to the current on grounds subject to overflow.—Esame degli
Studi sul Tevere, Section 53, and Appendice, Sections 33, 34.]
Page 640
Removal of Obstructions.
The removal of obstructions in the beds of rivers dredging the bottom or
blasting rocks, the washing out of deposits and locally increasing the depth
of water by narrowing the channel by moans of spurs or other constructions
projecting from the banks, and, finally, the cutting off of bends and thus
shortening the course of the stream, diminishing the resistance of its shores
and bottom and giving the bed a more rapid declivity, have all been
employed not only to facilitate navigation, but as auxiliaries to more
effectual modes of preventing inundations. But a bar removed from one
point is almost sure to re-form at the same or another, spurs occasion
injurious eddies and unforeseen diversions of the current, [Footnote: The
introduction of a new system of spurs with parabolic curves has been
attended with giant advantage in France.—Annales du Genie Civil, Mai,
1863.] and the cutting off of bends, though occasionally effected by nature
herself, and sometimes advantageous in torrential streams whose banks are
secured by solid walls of stone or other artificial constructions, seldom
establishes a permanent channel, and besides, the increased rapidity of the
flow through the new cut often injuriously affects the regime of the river for
a considerable distance below. [Footnote: This practice has sometimes been
resorted to on the Mississippi with advantage to navigation, but it is quite
another question whether that advantage has not been too dearly purchased
by the injury to the banks at lower points. If we suppose a river to have a
navigable course of 1,600 miles as measured by its natural channel, with a
descent of 800 feet, we shall have a fall of six inches to the mile. If the
length of channel be reduced to 1,200 miles by cutting off bends, the fall is
increased to eight inches per mile. The augmentation of velocity consequent
upon this increase of inclination is not computable without taking into
account other elements, such as depth and volume of water, diminution of
direct resistance, and the like, but in almost any supposable case, it would
be sufficient to produce great effects on the height of floods, the deposit of
The removal of obstructions in the beds of rivers dredging the bottom or
blasting rocks, the washing out of deposits and locally increasing the depth
of water by narrowing the channel by moans of spurs or other constructions
projecting from the banks, and, finally, the cutting off of bends and thus
shortening the course of the stream, diminishing the resistance of its shores
and bottom and giving the bed a more rapid declivity, have all been
employed not only to facilitate navigation, but as auxiliaries to more
effectual modes of preventing inundations. But a bar removed from one
point is almost sure to re-form at the same or another, spurs occasion
injurious eddies and unforeseen diversions of the current, [Footnote: The
introduction of a new system of spurs with parabolic curves has been
attended with giant advantage in France.—Annales du Genie Civil, Mai,
1863.] and the cutting off of bends, though occasionally effected by nature
herself, and sometimes advantageous in torrential streams whose banks are
secured by solid walls of stone or other artificial constructions, seldom
establishes a permanent channel, and besides, the increased rapidity of the
flow through the new cut often injuriously affects the regime of the river for
a considerable distance below. [Footnote: This practice has sometimes been
resorted to on the Mississippi with advantage to navigation, but it is quite
another question whether that advantage has not been too dearly purchased
by the injury to the banks at lower points. If we suppose a river to have a
navigable course of 1,600 miles as measured by its natural channel, with a
descent of 800 feet, we shall have a fall of six inches to the mile. If the
length of channel be reduced to 1,200 miles by cutting off bends, the fall is
increased to eight inches per mile. The augmentation of velocity consequent
upon this increase of inclination is not computable without taking into
account other elements, such as depth and volume of water, diminution of
direct resistance, and the like, but in almost any supposable case, it would
be sufficient to produce great effects on the height of floods, the deposit of
Page 641
sediment in the channel, on the shores, and at the outlet, the erosion of
banks and other points of much geographical importance.
The Po, in those parts of its course where the embankments leave a wide
space between, often cuts off bends in its channel and straightens its course.
These short cuts are called salti, or leaps, and sometimes abridge the
distance between their termini by several miles. In 1777, the salto of
Cottaro shortened a distance of 7,000 metres by 5,000, or, in other words,
reduced the length of the river by five kilometres, or about three miles, and
in 1807 and 1810 the two salti of Mozzanone effected a still greater
reduction.]
Combination of Methods.
Upon the whole, it is obvious that no one of the methods heretofore
practised or proposed for averting the evils resulting from river inundations
is capable of universal application. Each of them is specially suited to a
special case. But the hydrography of almost every considerable river and its
tributaries will be found to embrace most special cases, most known forms
of superficial fluid circulation. For rivers, in general, begin in the
mountains, traverse the plains, and end in the sea; they are torrents at their
sources, swelling streams in their middle course, placid currents, flowing
molli flumine, at their termination. Hence in the different parts of their
course the different methods of controlling and utilizing them may
successively find application, and there is every reason to believe that by a
judicious application of all, every great river may, in a considerable degree,
be deprived of its powers of evil and rendered subservient to the use, the
convenience, and the dominion of man. [Footnote: On the remedies against
inundation, see the valuable paper of Lombardini, Sulle Inondazioni
avvenute in questi ultimi tempi in Francia. Milano, 1858.
banks and other points of much geographical importance.
The Po, in those parts of its course where the embankments leave a wide
space between, often cuts off bends in its channel and straightens its course.
These short cuts are called salti, or leaps, and sometimes abridge the
distance between their termini by several miles. In 1777, the salto of
Cottaro shortened a distance of 7,000 metres by 5,000, or, in other words,
reduced the length of the river by five kilometres, or about three miles, and
in 1807 and 1810 the two salti of Mozzanone effected a still greater
reduction.]
Combination of Methods.
Upon the whole, it is obvious that no one of the methods heretofore
practised or proposed for averting the evils resulting from river inundations
is capable of universal application. Each of them is specially suited to a
special case. But the hydrography of almost every considerable river and its
tributaries will be found to embrace most special cases, most known forms
of superficial fluid circulation. For rivers, in general, begin in the
mountains, traverse the plains, and end in the sea; they are torrents at their
sources, swelling streams in their middle course, placid currents, flowing
molli flumine, at their termination. Hence in the different parts of their
course the different methods of controlling and utilizing them may
successively find application, and there is every reason to believe that by a
judicious application of all, every great river may, in a considerable degree,
be deprived of its powers of evil and rendered subservient to the use, the
convenience, and the dominion of man. [Footnote: On the remedies against
inundation, see the valuable paper of Lombardini, Sulle Inondazioni
avvenute in questi ultimi tempi in Francia. Milano, 1858.
Page 642
There can be no doubt that in the case of rivers which receive their
supply in a large measure from mountain streams, the methods described in
a former chapter as recently employed in South-eastern France to arrest the
formation and lessen the force of torrents, would prove equally useful as a
preventive remedy against inundations. They would both retard the delivery
of surface-water and diminish the discharge of sediment into rivers, thus
operating at once against the two most efficient causes of destructive floods.
See Chapter III., pp. 316 at seqq.]
Dikes of the Nile.
"History tells us," says Mengotti, "that the Nile became terrible and
destructive to ancient Egypt, in consequence of being confined within
elevated dikes, from the borders of Nubia to the sea. It being impossible for
these barriers to resist the pressure of its waters at such a height, its floods
burst its ramparts, sometimes on one side, sometimes on the other, and
deluged the plains, which lay far below the level of its current. . . . In one of
its formidable inundations the Nile overwhelmed and drowned a large part
of the population. The Egyptians then perceived that they were struggling
against nature in vain, and they resolved to remove the dikes, and permit the
river to expand itself laterally and raise by its deposits the surface of the
fields which border its channel." [Footnote: Idraulica Fisica e Sperimentale.
2d edizione, vol. i., pp. 131, 133.]
The original texts of the passages cited by Mengotti, from Latin
translations of Diodorus Siculus and Plutarch and from Pliny the Elder, do
not by any means confirm this statement, though the most important of
them, that from Diodorus Siculus, is, perhaps, not irreconcilable with it. Not
one of them speaks of the removal of the dikes, and I understand them all as
relating to the mixed system of embankments, reservoirs, and canals which
have been employed in Egypt through the whole period concerning which
supply in a large measure from mountain streams, the methods described in
a former chapter as recently employed in South-eastern France to arrest the
formation and lessen the force of torrents, would prove equally useful as a
preventive remedy against inundations. They would both retard the delivery
of surface-water and diminish the discharge of sediment into rivers, thus
operating at once against the two most efficient causes of destructive floods.
See Chapter III., pp. 316 at seqq.]
Dikes of the Nile.
"History tells us," says Mengotti, "that the Nile became terrible and
destructive to ancient Egypt, in consequence of being confined within
elevated dikes, from the borders of Nubia to the sea. It being impossible for
these barriers to resist the pressure of its waters at such a height, its floods
burst its ramparts, sometimes on one side, sometimes on the other, and
deluged the plains, which lay far below the level of its current. . . . In one of
its formidable inundations the Nile overwhelmed and drowned a large part
of the population. The Egyptians then perceived that they were struggling
against nature in vain, and they resolved to remove the dikes, and permit the
river to expand itself laterally and raise by its deposits the surface of the
fields which border its channel." [Footnote: Idraulica Fisica e Sperimentale.
2d edizione, vol. i., pp. 131, 133.]
The original texts of the passages cited by Mengotti, from Latin
translations of Diodorus Siculus and Plutarch and from Pliny the Elder, do
not by any means confirm this statement, though the most important of
them, that from Diodorus Siculus, is, perhaps, not irreconcilable with it. Not
one of them speaks of the removal of the dikes, and I understand them all as
relating to the mixed system of embankments, reservoirs, and canals which
have been employed in Egypt through the whole period concerning which
Page 643
we have clear information. I suppose that the disastrous inundations
referred to by the authors in question were simply extraordinary floods of
the same character as those which have been frequent at later periods of
Egyptian history, and I find nothing in support of the proposition that
continuous embankments along the banks of the Nile ever existed until such
were constructed by Mehemet Ali. [Footnote: The gradual elevation of the
bed of the Nile from sedimentary deposit, from the prolongation of the
Delta and consequent reduction of the inclination of the river-bed, or, as has
been supposed by some, though without probability, from a secular rise of
the coast, rendered necessary some change in the hydraulic arrangements of
Egypt. Mehemet Ali was advised to adopt a system of longitudinal levees,
and he embanked the river from Jebel Silsileh to the sea with dikes six or
seven feet high and twenty feet thick. Similar embankments were made
around the Delta. These dikes are provided with transverse embankments,
with sluices for admitting and canals for distributing the water, and they
serve rather to retain the water and control its flow than to exclude it. Clot
Bey, Apercu sur l'Egypte, ii., 437.]
The object of the dikes of the Po, and, with few exceptions, of those of
other European rivers, has always been to confine the waters of floods and
the solid material transported by them within as narrow a channel as
possible, and entirely to prevent them from flowing over the adjacent
plains. The object of the Egyptian dikes and canals is the reverse, namely, to
diffuse the swelling waters and their sediment over as wide a surface as
possible, to store them up until the soil they cover has them thoroughly
saturated and enriched, and then to conduct them over other grounds
requiring a longer or a second submersion, and, in general, to suffer none of
the precious fluid to escape except by evaporation and infiltration.
Lake Moeris, whether wholly an artificial excavation, or a natural basin
converted by embankments into a reservoir, was designed chiefly for the
referred to by the authors in question were simply extraordinary floods of
the same character as those which have been frequent at later periods of
Egyptian history, and I find nothing in support of the proposition that
continuous embankments along the banks of the Nile ever existed until such
were constructed by Mehemet Ali. [Footnote: The gradual elevation of the
bed of the Nile from sedimentary deposit, from the prolongation of the
Delta and consequent reduction of the inclination of the river-bed, or, as has
been supposed by some, though without probability, from a secular rise of
the coast, rendered necessary some change in the hydraulic arrangements of
Egypt. Mehemet Ali was advised to adopt a system of longitudinal levees,
and he embanked the river from Jebel Silsileh to the sea with dikes six or
seven feet high and twenty feet thick. Similar embankments were made
around the Delta. These dikes are provided with transverse embankments,
with sluices for admitting and canals for distributing the water, and they
serve rather to retain the water and control its flow than to exclude it. Clot
Bey, Apercu sur l'Egypte, ii., 437.]
The object of the dikes of the Po, and, with few exceptions, of those of
other European rivers, has always been to confine the waters of floods and
the solid material transported by them within as narrow a channel as
possible, and entirely to prevent them from flowing over the adjacent
plains. The object of the Egyptian dikes and canals is the reverse, namely, to
diffuse the swelling waters and their sediment over as wide a surface as
possible, to store them up until the soil they cover has them thoroughly
saturated and enriched, and then to conduct them over other grounds
requiring a longer or a second submersion, and, in general, to suffer none of
the precious fluid to escape except by evaporation and infiltration.
Lake Moeris, whether wholly an artificial excavation, or a natural basin
converted by embankments into a reservoir, was designed chiefly for the
Page 644
same purpose as the barrage built by Mougel Bey across the two great arms
which enclose the Delta, namely, as a magazine to furnish a perennial
supply of water to the thirsty soil. But these artificial arrangements alone
did not suffice. Canals were dug to receive the water at lower stages of the
river and conduct it far into the interior, and as all this was still not enough,
hundreds of thousands of wells were sunk to bring up from the subsoil, and
spread over the surface, the water which, by means of infiltration from the
river-bed, pervades the inferior strata of the whole valley. [Footnote: It is
said that in the Delta alone 50,000 wells are employed for irrigation.]
If a system of lofty continuous dikes, like those of the Po, had really been
adopted in Egypt, in the early dynasties when the power and the will to
undertake the most stupendous material enterprises were so eminently
characteristic of the government of that country, and persevered in through
later ages, and the waters of the annual inundation had thus been
permanently prevented from flooding the land, it is conceivable that the
productiveness of the small area of cultivable soil in the Nile valley might
have been long kept up by artificial irrigation and the application of
manures. But nature would have rebelled at last, and centuries before our
time the mighty river would have burst the fetters by which impotent man
had vainly striven to bind his swelling floods, the fertile fields of Egypt
would have been converted into dank morasses, and then, perhaps, in some
distant future, when the expulsion of man should have allowed the gradual
restoration of the primitive equilibrium, would be again transformed into
luxuriant garden and plough land. Fortunately, the sapientia AEgyptiorum,
the wisdom of the Egyptians, taught them better things. They invited and
welcomed, not repulsed, the slimy embraces of Nilus, and his favors have
been, from the hoariest antiquity, the greatest material blessing that nature
ever bestowed upon a people. [Footnote: Deep borings have not detected
any essential difference in the quantity or quality of the deposits of the Nile
for forty or fifty, or, as some compute, for a hundred centuries. From what
which enclose the Delta, namely, as a magazine to furnish a perennial
supply of water to the thirsty soil. But these artificial arrangements alone
did not suffice. Canals were dug to receive the water at lower stages of the
river and conduct it far into the interior, and as all this was still not enough,
hundreds of thousands of wells were sunk to bring up from the subsoil, and
spread over the surface, the water which, by means of infiltration from the
river-bed, pervades the inferior strata of the whole valley. [Footnote: It is
said that in the Delta alone 50,000 wells are employed for irrigation.]
If a system of lofty continuous dikes, like those of the Po, had really been
adopted in Egypt, in the early dynasties when the power and the will to
undertake the most stupendous material enterprises were so eminently
characteristic of the government of that country, and persevered in through
later ages, and the waters of the annual inundation had thus been
permanently prevented from flooding the land, it is conceivable that the
productiveness of the small area of cultivable soil in the Nile valley might
have been long kept up by artificial irrigation and the application of
manures. But nature would have rebelled at last, and centuries before our
time the mighty river would have burst the fetters by which impotent man
had vainly striven to bind his swelling floods, the fertile fields of Egypt
would have been converted into dank morasses, and then, perhaps, in some
distant future, when the expulsion of man should have allowed the gradual
restoration of the primitive equilibrium, would be again transformed into
luxuriant garden and plough land. Fortunately, the sapientia AEgyptiorum,
the wisdom of the Egyptians, taught them better things. They invited and
welcomed, not repulsed, the slimy embraces of Nilus, and his favors have
been, from the hoariest antiquity, the greatest material blessing that nature
ever bestowed upon a people. [Footnote: Deep borings have not detected
any essential difference in the quantity or quality of the deposits of the Nile
for forty or fifty, or, as some compute, for a hundred centuries. From what
Page 645
vast store of rich earth does this river derive the three or four inches of
fertilizing material which it spreads over the soil of Egypt every hundred
years Not from the White Nile, for that river drops nearly all its suspended
matter in the broad expansions and slow current of its channel south of the
tenth degree of north latitude. Nor does it appear that much sediment is
contributed by the Bahr-el-Azrek, which flows through forests for a great
part of its course. I have been informed by an old European resident of
Egypt who is very familiar with the Upper Nile, that almost the whole of
the earth with which its waters are charged is brought down by the
Takazze.]
Deposits of the Nile.
The Nile is larger than all the rivers of Lombardy together, [Footnote:
From daily measurements during a period of fourteen years—1827 to 1840
—the mean delivery of the Po at Ponte Lagoscuro, below the entrance of its
last tributary, is found to be 1,720 cubic metres, or 60,745 cubic feet, per
second. Its smallest delivery is 186 cubic metres, or 6,569 cubic feet, its
greatest 5,156 cubic metres, or 152,094 cubic feet. The average delivery of
the Nile being 101,000 cubic feet per second, it follows that the Po
contributes to the Adriatic rather more than six-tenths as much water as the
Nile to the Mediterranean—a result which will surprise most readers.
It is worth remembering that the mean delivery of the Rhone is almost
identical with that of the Po, and that of the Rhine is very nearly the same.
Though the Po receives four-tenths of its water from lakes, in which the
streams that empty into them let fall the solid material they bring down
from the mountains, its deposits in the Adriatic are at least sixty or seventy
per cent. greater than those transported to the Mediterranean by the Rhone,
which derives most of its supply from mountain and torrential tributaries.
Those tributaries lodge much sediment in the Lake of Geneva and the Lac
fertilizing material which it spreads over the soil of Egypt every hundred
years Not from the White Nile, for that river drops nearly all its suspended
matter in the broad expansions and slow current of its channel south of the
tenth degree of north latitude. Nor does it appear that much sediment is
contributed by the Bahr-el-Azrek, which flows through forests for a great
part of its course. I have been informed by an old European resident of
Egypt who is very familiar with the Upper Nile, that almost the whole of
the earth with which its waters are charged is brought down by the
Takazze.]
Deposits of the Nile.
The Nile is larger than all the rivers of Lombardy together, [Footnote:
From daily measurements during a period of fourteen years—1827 to 1840
—the mean delivery of the Po at Ponte Lagoscuro, below the entrance of its
last tributary, is found to be 1,720 cubic metres, or 60,745 cubic feet, per
second. Its smallest delivery is 186 cubic metres, or 6,569 cubic feet, its
greatest 5,156 cubic metres, or 152,094 cubic feet. The average delivery of
the Nile being 101,000 cubic feet per second, it follows that the Po
contributes to the Adriatic rather more than six-tenths as much water as the
Nile to the Mediterranean—a result which will surprise most readers.
It is worth remembering that the mean delivery of the Rhone is almost
identical with that of the Po, and that of the Rhine is very nearly the same.
Though the Po receives four-tenths of its water from lakes, in which the
streams that empty into them let fall the solid material they bring down
from the mountains, its deposits in the Adriatic are at least sixty or seventy
per cent. greater than those transported to the Mediterranean by the Rhone,
which derives most of its supply from mountain and torrential tributaries.
Those tributaries lodge much sediment in the Lake of Geneva and the Lac
Page 646
de Bourget, but the total erosion of the Po and its affluents must be
considerably greater than that of the Rhone system. The Rhine conveys to
the sea much less sediment than either of the other two rivers.—
Lombardini, Cargiamenti nella condizione del Po, pp. 29, 39.
The mean discharge of the Mississippi is 675,000 cubic feet per second,
and, accordingly, that river contributes to the sea about eleven times as
much water as the Po, and more than six and a half times as much as the
Nile. The discharge of the Mississippi is estimated at one-fourth of the
precipitation in its basin—certainly a very large proportion, when we
consider the rapidity of evaporation in many parts of the basin, and the
probable loss by infiltration.—Humphreys and Abbott'S Report, p. 93.
The basin of the Mississippi has an area forty-six times as large as that of
the Po, with a mean annual precipitation of thirty inches, while that of the
Po, at least according to official statistics, has a precipitation of forty
inches. Hence the down-fall in the former is one-fourth less than in the
latter. Besides this, the Mississippi loses little or nothing by the diversion of
its waters for irrigation. Consequently the measured discharge of the
Mississippi is proportionally much less than that of the Po, and we are
authorized to conclude that the difference is partly due to the escape of
water from the bed, or at least the basin of the Mississippi, by subterranean
channels.
These comparisons are interesting in reference to the supply received by
the sea directly from great rivers, but they fail to give a true idea of the real
volume of the latter. To take the case of the Nile and the Po: we have reason
to suppose that comparatively little water is diverted from the tributaries of
the former for irrigation, but enormous quantities are drawn from its main
trunk for that purpose, below the point where it receives its last affluent.
This quantity is now increasing in so rapid a proportion, that Elisee Reclus
considerably greater than that of the Rhone system. The Rhine conveys to
the sea much less sediment than either of the other two rivers.—
Lombardini, Cargiamenti nella condizione del Po, pp. 29, 39.
The mean discharge of the Mississippi is 675,000 cubic feet per second,
and, accordingly, that river contributes to the sea about eleven times as
much water as the Po, and more than six and a half times as much as the
Nile. The discharge of the Mississippi is estimated at one-fourth of the
precipitation in its basin—certainly a very large proportion, when we
consider the rapidity of evaporation in many parts of the basin, and the
probable loss by infiltration.—Humphreys and Abbott'S Report, p. 93.
The basin of the Mississippi has an area forty-six times as large as that of
the Po, with a mean annual precipitation of thirty inches, while that of the
Po, at least according to official statistics, has a precipitation of forty
inches. Hence the down-fall in the former is one-fourth less than in the
latter. Besides this, the Mississippi loses little or nothing by the diversion of
its waters for irrigation. Consequently the measured discharge of the
Mississippi is proportionally much less than that of the Po, and we are
authorized to conclude that the difference is partly due to the escape of
water from the bed, or at least the basin of the Mississippi, by subterranean
channels.
These comparisons are interesting in reference to the supply received by
the sea directly from great rivers, but they fail to give a true idea of the real
volume of the latter. To take the case of the Nile and the Po: we have reason
to suppose that comparatively little water is diverted from the tributaries of
the former for irrigation, but enormous quantities are drawn from its main
trunk for that purpose, below the point where it receives its last affluent.
This quantity is now increasing in so rapid a proportion, that Elisee Reclus
Page 647
foresees the day when the entire low-water current will be absorbed by new
arrangements to meet the needs of extended and improved agriculture. On
the other hand, while the affluents of the Po send off a great quantity of
water into canals of irrigation, the main trunk loses little or nothing in that
way except at Chivasso. Trustworthy data are wanting to enable us to
estimate how far these different modes of utilizing the water balance each
other in the case under consideration. Perhaps the Canal Cavour, and other
irrigating canals now proposed, may one day intercept as large a proportion
of the supply of the lower Po as Egyptian dikes, canals, shadoofs, and
steam-pumps do of that of the Nile.
Another circumstance is important to be considered in comparing the
character of these three rivers. The Po runs nearly east and west, and it and
its tributaries are exposed to no other difference of meterological conditions
than those which always subsist between the mountains and the plains. The
course of the Nile and the Mississippi is mainly north and south. The
sources of the Nile are in a very humid region, its lower course for many
hundred miles in almost rainless latitudes with enormous evaporating
power, while the precipitation is large throughout the Mississippi system,
except in the basins of some of its western affluents.] it drains a basin fifty,
possibly even a hundred, times as extensive, its banks have been occupied
by man probably twice as long. But its geographical character has not been
much changed in the whole period of recorded history, and, though its
outlets have somewhat fluctuated in number and position, its historically
known encroachments upon the sea are trifling compared with those of the
Po and the neighboring streams. The deposits of the Nile are naturally
greater in Upper than in Lower Egypt. They are found to have raised the
soil at Thebes about seven feet within the last seventeen hundred years, and
in the Delta the rise has been certainly more than half as great.
arrangements to meet the needs of extended and improved agriculture. On
the other hand, while the affluents of the Po send off a great quantity of
water into canals of irrigation, the main trunk loses little or nothing in that
way except at Chivasso. Trustworthy data are wanting to enable us to
estimate how far these different modes of utilizing the water balance each
other in the case under consideration. Perhaps the Canal Cavour, and other
irrigating canals now proposed, may one day intercept as large a proportion
of the supply of the lower Po as Egyptian dikes, canals, shadoofs, and
steam-pumps do of that of the Nile.
Another circumstance is important to be considered in comparing the
character of these three rivers. The Po runs nearly east and west, and it and
its tributaries are exposed to no other difference of meterological conditions
than those which always subsist between the mountains and the plains. The
course of the Nile and the Mississippi is mainly north and south. The
sources of the Nile are in a very humid region, its lower course for many
hundred miles in almost rainless latitudes with enormous evaporating
power, while the precipitation is large throughout the Mississippi system,
except in the basins of some of its western affluents.] it drains a basin fifty,
possibly even a hundred, times as extensive, its banks have been occupied
by man probably twice as long. But its geographical character has not been
much changed in the whole period of recorded history, and, though its
outlets have somewhat fluctuated in number and position, its historically
known encroachments upon the sea are trifling compared with those of the
Po and the neighboring streams. The deposits of the Nile are naturally
greater in Upper than in Lower Egypt. They are found to have raised the
soil at Thebes about seven feet within the last seventeen hundred years, and
in the Delta the rise has been certainly more than half as great.
Page 648
We shall, therefore, probably not exceed the truth if we suppose the
annually inundated surface of Egypt to have been elevated, upon an
average, ten feet, [Footnote: Fraas and Eyth maintain that we have no
trustworthy data for calculating the annual or secular elevation of the soil of
Egypt by the sediment of the Nile. The deposit, they say, is variable from
irregularity of current, and especially from the interference of man with the
operations of nature, to a degree which renders any probable computation
of the amount quite impossible.—Fraas, Aus dem Orient, pp. 212, 213.
The sedimentary matter transported by the Nile might doubtless be
estimated with approximate precision by careful observation of the
proportion of suspended slime and water at different stations and seasons
for a few successive years. Figari Bey states that at low stages the water of
the Nile contains little or no sediment, and that the greatest proportion
occurs about the end of July, and of course, while the river is still rising.
Experiments at Khartum at that season showed solid matter in the
proportion of one to a thousand by weight. The quantity is relatively greater
at Cairo, a fact which shows that the river receives more earth from the
erosion of its banks than it deposits at its own bottom, and it must
consequently widen its channel unless we suppose a secular depression of
the coast at the mouth of the Nile which produces an increased inclination
of the bed of the river, and consequently an augmented velocity of flow
sufficient to sweep out earth from the bottom and mix it with the current.
Herschell states the Nile sediment at 1 in 633 by weight, and computes
the entire annual quantity at 140 millions of tons.—Physical Geography, p.
231.
The mean proportion of sedimentary material in the waters of the
Mississippi is calculated at 1 to 1,500 by weight, and 1 to 2,900 in volume,
and the total annual quantity at 812,500,000,000 pounds, which would
annually inundated surface of Egypt to have been elevated, upon an
average, ten feet, [Footnote: Fraas and Eyth maintain that we have no
trustworthy data for calculating the annual or secular elevation of the soil of
Egypt by the sediment of the Nile. The deposit, they say, is variable from
irregularity of current, and especially from the interference of man with the
operations of nature, to a degree which renders any probable computation
of the amount quite impossible.—Fraas, Aus dem Orient, pp. 212, 213.
The sedimentary matter transported by the Nile might doubtless be
estimated with approximate precision by careful observation of the
proportion of suspended slime and water at different stations and seasons
for a few successive years. Figari Bey states that at low stages the water of
the Nile contains little or no sediment, and that the greatest proportion
occurs about the end of July, and of course, while the river is still rising.
Experiments at Khartum at that season showed solid matter in the
proportion of one to a thousand by weight. The quantity is relatively greater
at Cairo, a fact which shows that the river receives more earth from the
erosion of its banks than it deposits at its own bottom, and it must
consequently widen its channel unless we suppose a secular depression of
the coast at the mouth of the Nile which produces an increased inclination
of the bed of the river, and consequently an augmented velocity of flow
sufficient to sweep out earth from the bottom and mix it with the current.
Herschell states the Nile sediment at 1 in 633 by weight, and computes
the entire annual quantity at 140 millions of tons.—Physical Geography, p.
231.
The mean proportion of sedimentary material in the waters of the
Mississippi is calculated at 1 to 1,500 by weight, and 1 to 2,900 in volume,
and the total annual quantity at 812,500,000,000 pounds, which would
Page 649
cover one square mile to the depth of 214 feet.—Humphreys and Abbott,
Report, p. 140.] within the last 5,000 years, or twice and a half the period
during which the history of the Po is known to us. [Footnote: We are quite
safe in supposing that the valley of the Nile has been occupied by man at
least 5,000 years. The dates of Egyptian chronology are uncertain, but I
believe no inquirer estimates the age of the great pyramids at less than forty
centuries, and the construction of such works implies an already ancient
civilization.
It is an interesting fact that the old Egyptian system of embankments and
canals is probably more ancient than the geological changes which have
converted the Mississippi from a limpid to a turbid stream, and occasioned
the formation of the vast delta at the mouth of that river. Humphreys and
Abbot conclude that the delta of the Mississippi began its encroachments on
the Gulf of Mexico not more than 4,400 years ago, before which period
they suppose the Mississippi to have been "a comparatively clear stream,"
conveying very little sediment to the sea. The present rate of advance of the
delta is 262 feet a year, and there are reasons for thinking that the amount of
deposit has long been approximately constant.—Report, pp. 435, 436.]
As I have observed, the area of cultivated soil is much less extensive now
than under the dynasties of the Pharaohs and the Ptolemies; for—though, in
consequence of the elevation of the river-bed, the inundations now have a
wider NATURAL spread—the industry of the ancient Egyptians conducted
the Nile water over a great surface which it does not now reach.
Had the Nile been banked in, like the Po, all this deposit, except that
contained in the water diverted by canals or otherwise drawn from the river
for irrigation and other purposes, would have soon carried out to sea. This
would have been a considerable quantity; for the Nile holds some earth in
suspension at all seasons except at the very lowest water, a much larger
Report, p. 140.] within the last 5,000 years, or twice and a half the period
during which the history of the Po is known to us. [Footnote: We are quite
safe in supposing that the valley of the Nile has been occupied by man at
least 5,000 years. The dates of Egyptian chronology are uncertain, but I
believe no inquirer estimates the age of the great pyramids at less than forty
centuries, and the construction of such works implies an already ancient
civilization.
It is an interesting fact that the old Egyptian system of embankments and
canals is probably more ancient than the geological changes which have
converted the Mississippi from a limpid to a turbid stream, and occasioned
the formation of the vast delta at the mouth of that river. Humphreys and
Abbot conclude that the delta of the Mississippi began its encroachments on
the Gulf of Mexico not more than 4,400 years ago, before which period
they suppose the Mississippi to have been "a comparatively clear stream,"
conveying very little sediment to the sea. The present rate of advance of the
delta is 262 feet a year, and there are reasons for thinking that the amount of
deposit has long been approximately constant.—Report, pp. 435, 436.]
As I have observed, the area of cultivated soil is much less extensive now
than under the dynasties of the Pharaohs and the Ptolemies; for—though, in
consequence of the elevation of the river-bed, the inundations now have a
wider NATURAL spread—the industry of the ancient Egyptians conducted
the Nile water over a great surface which it does not now reach.
Had the Nile been banked in, like the Po, all this deposit, except that
contained in the water diverted by canals or otherwise drawn from the river
for irrigation and other purposes, would have soon carried out to sea. This
would have been a considerable quantity; for the Nile holds some earth in
suspension at all seasons except at the very lowest water, a much larger
Page 650
proportion during the flood, and irrigation must have been carried on during
the whole year. The precise amount of sediment which would have been
thus distributed over the soil is matter of conjecture, but though large, it
would have been much less than the inundations have deposited, and
continuous longitudinal embankments would have compelled the Nile to
transport to the Mediterranean an immense quantity over and above what it
has actually deposited in that sea. The Mediterranean is shoal for some
miles out to sea along the whole coast of the Delta, and the large bays or
lagoons within the coast-line, which communicate both with the river and
the sea, have little depth of water. These lagoons the river deposits would
have filled up, and there would still have been surplus earth enough to
extend the Delta far into the Mediterranean.
[Footnote: The present annual extension of the Delta is, if perceptible, at
all events very small. According to some authorities, a few hectares are
added every year at each Nile mouth. Others, among whom I may mention
Fraas, deny that there is any extension at all, the deposit being balanced by
a secular depression of the coast.
Elisee Reclus states that the Delta advances about 40 inches per year.—
La Terre, i., p. 500.]
Obstruction of River Mouths.
The mouths of a large proportion of the streams known to ancient
navigation are already blocked up by sand-bars or fluviatile deposits, and
the maritime approaches to river harbors frequented by the ships of
Phenicia and Carthage and Greece and Rome are shoaled to a considerable
distance out to sea. The inclination of the lower course of almost every
known river bed has been considerably reduced within the historical period,
and nothing but great volume of water, or exceptional rapidity of flow, now
enables a few large streams like the Amazon, the La Plata, the Ganges, and,
the whole year. The precise amount of sediment which would have been
thus distributed over the soil is matter of conjecture, but though large, it
would have been much less than the inundations have deposited, and
continuous longitudinal embankments would have compelled the Nile to
transport to the Mediterranean an immense quantity over and above what it
has actually deposited in that sea. The Mediterranean is shoal for some
miles out to sea along the whole coast of the Delta, and the large bays or
lagoons within the coast-line, which communicate both with the river and
the sea, have little depth of water. These lagoons the river deposits would
have filled up, and there would still have been surplus earth enough to
extend the Delta far into the Mediterranean.
[Footnote: The present annual extension of the Delta is, if perceptible, at
all events very small. According to some authorities, a few hectares are
added every year at each Nile mouth. Others, among whom I may mention
Fraas, deny that there is any extension at all, the deposit being balanced by
a secular depression of the coast.
Elisee Reclus states that the Delta advances about 40 inches per year.—
La Terre, i., p. 500.]
Obstruction of River Mouths.
The mouths of a large proportion of the streams known to ancient
navigation are already blocked up by sand-bars or fluviatile deposits, and
the maritime approaches to river harbors frequented by the ships of
Phenicia and Carthage and Greece and Rome are shoaled to a considerable
distance out to sea. The inclination of the lower course of almost every
known river bed has been considerably reduced within the historical period,
and nothing but great volume of water, or exceptional rapidity of flow, now
enables a few large streams like the Amazon, the La Plata, the Ganges, and,
Page 651
in a loss degree, the Mississippi, to carry their own deposits far enough out
into deep water to prevent the formation of serious obstructions to
navigation. But the degradation of their banks, and the transportation of
earthy matter to the sea by their currents, are gradually filling up the
estuaries even of those mighty floods, and unless the threatened evil shall
be averted by the action of geological forces, or by artificial contrivances
more efficient than dredging-machines, the destruction of every harbor in
the world which receives a considerable river must inevitably take place at
no very distant date.
This result would, perhaps, have followed in some incalculably distant
future, if man had not come to inhabit the earth as soon as the natural forces
which had formed its surface had arrived at such an approximate
equilibrium that his existence on the globe was possible; but the general
effect of his industrial operations has been to accelerate it immensely.
Rivers, in countries planted by nature with forests and never inhabited by
man, employ the little earth and gravel they transport chiefly to raise their
own beds and to form plains in their basins. In their upper course, where the
current is swiftest, they are most heavily charged with coarse rolled or
suspended matter, and this, in floods, they deposit on their shores in the
mountain valleys where they rise; in their middle course, a lighter earth is
spread over the bottom of their widening basins, and forms plains of
moderate extent; the fine silt which floats farther is deposited over a still
broader area, or, if carried out to sea, is in great part quickly swept far off
by marine currents and dropped at last in deep water. Man's "improvement"
of the soil increased the erosion from its surface; his arrangements for
confining the lateral spread of the water in floods compel the rivers to
transport to their mouths the earth derived from that erosion even in their
upper course; and, consequently, the sediment they deposit at their outlets is
not only much larger in quantity, but composed of heavier materials, which
into deep water to prevent the formation of serious obstructions to
navigation. But the degradation of their banks, and the transportation of
earthy matter to the sea by their currents, are gradually filling up the
estuaries even of those mighty floods, and unless the threatened evil shall
be averted by the action of geological forces, or by artificial contrivances
more efficient than dredging-machines, the destruction of every harbor in
the world which receives a considerable river must inevitably take place at
no very distant date.
This result would, perhaps, have followed in some incalculably distant
future, if man had not come to inhabit the earth as soon as the natural forces
which had formed its surface had arrived at such an approximate
equilibrium that his existence on the globe was possible; but the general
effect of his industrial operations has been to accelerate it immensely.
Rivers, in countries planted by nature with forests and never inhabited by
man, employ the little earth and gravel they transport chiefly to raise their
own beds and to form plains in their basins. In their upper course, where the
current is swiftest, they are most heavily charged with coarse rolled or
suspended matter, and this, in floods, they deposit on their shores in the
mountain valleys where they rise; in their middle course, a lighter earth is
spread over the bottom of their widening basins, and forms plains of
moderate extent; the fine silt which floats farther is deposited over a still
broader area, or, if carried out to sea, is in great part quickly swept far off
by marine currents and dropped at last in deep water. Man's "improvement"
of the soil increased the erosion from its surface; his arrangements for
confining the lateral spread of the water in floods compel the rivers to
transport to their mouths the earth derived from that erosion even in their
upper course; and, consequently, the sediment they deposit at their outlets is
not only much larger in quantity, but composed of heavier materials, which
Page 652
sink more readily to the bottom of the sea and are less easily removed by
marine currents.
The tidal movement of the ocean, deep-sea currents, and the agitation of
inland waters by the wind, lift up the sands strewn over the bottom by
diluvial streams or sent down by mountain torrents, and throw them up on
dry land, or deposit them in sheltered bays and nooks of the coast—for the
flowing is stronger than the ebbing tide, the affluent than the refluent wave.
This cause of injury to harbors it is not in man's power to resist by any
means at present available; but, as we have seen, something can be done to
prevent the degradation of high grounds, and to diminish the quantity of
earth which is annually abstracted from the mountains, from table-lands,
and from river-banks, to raise the bottom of the sea.
This latter cause of harbor obstruction, though an active agent, is,
nevertheless, in many cases, the less powerful of the two. The earth
suspended in the lower course of fluviatile currents is lighter than sea-sand,
river water lighter than sea water, and hence, if a land stream enters the sea
with a considerable volume, its water flows over that of the sea, and bears
its slime with it until it lets it fall far from shore, or, as is more frequently
the case, mingles with some marine current and transports its sediment to a
remote point of deposit. The earth borne out of the mouths of the Nile is in
part carried over the waves which throw up sea-sand on the beach, and
deposited in deep water, in part drifted by the current, which sweeps east
and north along the coasts of Egypt and Syria, and lodged in every nook
along the shore—and among others, to the great detriment of the Suez
Canal, in the artificial harbor at its northern terminus—and in part borne
along until it finds a final resting-place in the north-eastern angle of the
Mediterranean. [Footnote: "The stream carries this mud, etc., at first farther
to the east, and only lets it fall where the force of the current becomes
weakened. This explains the continual advance of the land seaward along
marine currents.
The tidal movement of the ocean, deep-sea currents, and the agitation of
inland waters by the wind, lift up the sands strewn over the bottom by
diluvial streams or sent down by mountain torrents, and throw them up on
dry land, or deposit them in sheltered bays and nooks of the coast—for the
flowing is stronger than the ebbing tide, the affluent than the refluent wave.
This cause of injury to harbors it is not in man's power to resist by any
means at present available; but, as we have seen, something can be done to
prevent the degradation of high grounds, and to diminish the quantity of
earth which is annually abstracted from the mountains, from table-lands,
and from river-banks, to raise the bottom of the sea.
This latter cause of harbor obstruction, though an active agent, is,
nevertheless, in many cases, the less powerful of the two. The earth
suspended in the lower course of fluviatile currents is lighter than sea-sand,
river water lighter than sea water, and hence, if a land stream enters the sea
with a considerable volume, its water flows over that of the sea, and bears
its slime with it until it lets it fall far from shore, or, as is more frequently
the case, mingles with some marine current and transports its sediment to a
remote point of deposit. The earth borne out of the mouths of the Nile is in
part carried over the waves which throw up sea-sand on the beach, and
deposited in deep water, in part drifted by the current, which sweeps east
and north along the coasts of Egypt and Syria, and lodged in every nook
along the shore—and among others, to the great detriment of the Suez
Canal, in the artificial harbor at its northern terminus—and in part borne
along until it finds a final resting-place in the north-eastern angle of the
Mediterranean. [Footnote: "The stream carries this mud, etc., at first farther
to the east, and only lets it fall where the force of the current becomes
weakened. This explains the continual advance of the land seaward along
Page 653
the Syrian coast, in consequence of which Tyre and Sideon no longer lie on
the shore, but some distance inland. That the Nile contributes to this deposit
may easily be seen, even by the unscientific observer, from the stained and
turbid character of the water for many miles from its mouths. Ships often
encounter floating masses of Nile mud, and Dr. Clarke thus describes a case
of this sort:
"While we were at table, we heard the sailors who were throwing the lead
suddenly cry out: 'Three and a half!' The ship slackened her way, and
veered about. As she came round, the whole surface of the water was seen
to be covered with thick, black mud, which extended so far that it appeared
like an island. At the same time, actual land was nowhere to be seen—not
even from the mast-head—nor was any notice of such a shoal to be found
or any chart on board. The fact is, as we learned afterwards, that a stratum
of mud, stretching from the mouths of the Nile for many miles out into the
open sea, forms a movable deposit along the Egyptian coast. If this deposit
is driven forwards by powerful currents, it sometimes rises to the surface,
and disturbs the mariner by the sudden appearance of shoals where the
charts lead him to expect a considerable depth of water. But these strata of
mud are, in reality, not in the least dangerous. As soon as a ship strikes them
they break up at once, and a frigate may hold her course in perfect safety
where an inexperienced pilot, misled by his soundings, would every
moment expect to be stranded."—Bottger, Das Mittchneer, pp. 188, 189.
This phenomenon is not peculiar to the locality in question, and it is
frequently observed in the Gulf of Bengal, and other great marine
estuaries.]
Thus the earth loosened by the rude Abyssinian ploughshare, and washed
down by the rain from the hills of Ethiopia which man has stripped of their
protecting forests, contributes to raise the plains of Egypt, to shoal the
the shore, but some distance inland. That the Nile contributes to this deposit
may easily be seen, even by the unscientific observer, from the stained and
turbid character of the water for many miles from its mouths. Ships often
encounter floating masses of Nile mud, and Dr. Clarke thus describes a case
of this sort:
"While we were at table, we heard the sailors who were throwing the lead
suddenly cry out: 'Three and a half!' The ship slackened her way, and
veered about. As she came round, the whole surface of the water was seen
to be covered with thick, black mud, which extended so far that it appeared
like an island. At the same time, actual land was nowhere to be seen—not
even from the mast-head—nor was any notice of such a shoal to be found
or any chart on board. The fact is, as we learned afterwards, that a stratum
of mud, stretching from the mouths of the Nile for many miles out into the
open sea, forms a movable deposit along the Egyptian coast. If this deposit
is driven forwards by powerful currents, it sometimes rises to the surface,
and disturbs the mariner by the sudden appearance of shoals where the
charts lead him to expect a considerable depth of water. But these strata of
mud are, in reality, not in the least dangerous. As soon as a ship strikes them
they break up at once, and a frigate may hold her course in perfect safety
where an inexperienced pilot, misled by his soundings, would every
moment expect to be stranded."—Bottger, Das Mittchneer, pp. 188, 189.
This phenomenon is not peculiar to the locality in question, and it is
frequently observed in the Gulf of Bengal, and other great marine
estuaries.]
Thus the earth loosened by the rude Abyssinian ploughshare, and washed
down by the rain from the hills of Ethiopia which man has stripped of their
protecting forests, contributes to raise the plains of Egypt, to shoal the
Page 654
maritime channels which lead to the city built by Alexander near the mouth
of the Nile, to obstruct the artificial communication between the
Mediterranean and the Red Sea, and to fill up the harbors made famous by
Phenician commerce.
Deposits of the Tuscan Rivers.
The Arno, and all the rivers rising on the western slopes and spurs of the
Apennines, carry down immense quantities of mud to the Mediterranean.
There can be no doubt that the volume of earth so transported is very much
greater than it would have been had the soil about the headwaters of those
rivers continued to be protected from wash by forests; and there is as little
question that the quantity borne out to sea by the rivers of Western Italy is
much increased by artificial embankments, because they are thereby
prevented from spreading over the surface the sedimentary matter with
which they are charged. The western coast of Tuscany has advanced some
miles seawards within a very few centuries. The bed of the sea, for a long
distance, has been raised, and of course the relative elevation of the land
above it lessened; harbors have been filled up and destroyed; long lines of
coast dunes have been formed, and the diminished inclination of the beds of
the rivers near their outlets has caused their waters to overflow their banks
and convert them into pestilential marshes. The territorial extent of Western
Italy has thus been considerably increased, but the amount of soil habitable
and cultivable by man has been, in a still higher proportion, diminished.
The coast of ancient Etruria was filled with great commercial towns, and
their rural environs were occupied by a large and prosperous population.
But maritime Tuscany has long been one of the most unhealthy districts in
Christendom; the famous Etruscan mart of Populonia has scarcely an
inhabitant; the coast is almost absolutely depopulated, and the malarious
fevers have extended their ravages far into the interior.
of the Nile, to obstruct the artificial communication between the
Mediterranean and the Red Sea, and to fill up the harbors made famous by
Phenician commerce.
Deposits of the Tuscan Rivers.
The Arno, and all the rivers rising on the western slopes and spurs of the
Apennines, carry down immense quantities of mud to the Mediterranean.
There can be no doubt that the volume of earth so transported is very much
greater than it would have been had the soil about the headwaters of those
rivers continued to be protected from wash by forests; and there is as little
question that the quantity borne out to sea by the rivers of Western Italy is
much increased by artificial embankments, because they are thereby
prevented from spreading over the surface the sedimentary matter with
which they are charged. The western coast of Tuscany has advanced some
miles seawards within a very few centuries. The bed of the sea, for a long
distance, has been raised, and of course the relative elevation of the land
above it lessened; harbors have been filled up and destroyed; long lines of
coast dunes have been formed, and the diminished inclination of the beds of
the rivers near their outlets has caused their waters to overflow their banks
and convert them into pestilential marshes. The territorial extent of Western
Italy has thus been considerably increased, but the amount of soil habitable
and cultivable by man has been, in a still higher proportion, diminished.
The coast of ancient Etruria was filled with great commercial towns, and
their rural environs were occupied by a large and prosperous population.
But maritime Tuscany has long been one of the most unhealthy districts in
Christendom; the famous Etruscan mart of Populonia has scarcely an
inhabitant; the coast is almost absolutely depopulated, and the malarious
fevers have extended their ravages far into the interior.
Page 655
These results are certainly not to be ascribed wholly to human action.
They are, in a large proportion, due to geological causes over which man
has no control. The soil of much of Tuscany becomes pasty, almost fluid
even, as soon as it is moistened, and when thoroughly saturated with water,
it flows like a river. Such a soil as this would not be completely protected
by woods, and, indeed, it would now be difficult to confine it long enough
to allow it to cover itself with forest vegetation. Nevertheless, it certainly
was once chiefly wooded, and the rivers which flow through it must then
have been much less charged with earthy matter than at present, and they
must have carried into the sea a smaller proportion of their sediment when
they were free to deposit it on their banks than since they have been
confined by dikes.
It is, in general, true, that the intervention of man has hitherto seemed to
insure the final exhaustion, ruin, and desolation of every province of nature
which he has reduced to his dominion. Attila was only giving an energetic
and picturesque expression to the tendencies of human action, as
personified in himself, when he said that "no grass grew where his horse's
hoofs had trod." The instances are few, where a second civilization has
flourished upon the ruins of an ancient culture, and lands once rendered
uninhabitable by human acts or neglect have generally been forever
abandoned as hopelessly irreclaimable. It is, as I have before remarked, a
question of vast importance, how far it is practicable to restore the garden
we have wasted, and it is a problem on which experience throws little light,
because few deliberate attempts have yet been made at the work of physical
regeneration, on a scale large enough to warrant general conclusions in any
one class of cases.
The valleys and shores of Tuscany form, however, a striking exception to
this remark. The succcess with which human guidance has made the
operations of nature herself available for the restoration of her disturbed
They are, in a large proportion, due to geological causes over which man
has no control. The soil of much of Tuscany becomes pasty, almost fluid
even, as soon as it is moistened, and when thoroughly saturated with water,
it flows like a river. Such a soil as this would not be completely protected
by woods, and, indeed, it would now be difficult to confine it long enough
to allow it to cover itself with forest vegetation. Nevertheless, it certainly
was once chiefly wooded, and the rivers which flow through it must then
have been much less charged with earthy matter than at present, and they
must have carried into the sea a smaller proportion of their sediment when
they were free to deposit it on their banks than since they have been
confined by dikes.
It is, in general, true, that the intervention of man has hitherto seemed to
insure the final exhaustion, ruin, and desolation of every province of nature
which he has reduced to his dominion. Attila was only giving an energetic
and picturesque expression to the tendencies of human action, as
personified in himself, when he said that "no grass grew where his horse's
hoofs had trod." The instances are few, where a second civilization has
flourished upon the ruins of an ancient culture, and lands once rendered
uninhabitable by human acts or neglect have generally been forever
abandoned as hopelessly irreclaimable. It is, as I have before remarked, a
question of vast importance, how far it is practicable to restore the garden
we have wasted, and it is a problem on which experience throws little light,
because few deliberate attempts have yet been made at the work of physical
regeneration, on a scale large enough to warrant general conclusions in any
one class of cases.
The valleys and shores of Tuscany form, however, a striking exception to
this remark. The succcess with which human guidance has made the
operations of nature herself available for the restoration of her disturbed
Page 656
harmonies, in the Val di Chiana and the Tuscan Maremma, is among the
noblest, if not the most brilliant achievements of modern engineering, and,
regarded in all its bearings on the great question of which I have just
spoken, it is, as an example, of more importance to the general interests of
humanity than the proudest work of internal improvement that mechanical
means have yet constructed. The operations in the Val di Chiana have
consisted chiefly in so regulating the flow of the surface-waters into and
through it, as to compel them to deposit their sedimentary matter at the will
of the engineers, and thereby to raise grounds rendered insalubrious and
unfit for agricultural use by stagnating water; the improvements in the
Maremma have embraced both this method of elevating the level of the soil,
and the prevention of the mixture of salt-water with fresh in the coast
marshes and shallow bays, which is regarded as a very active cause of the
development of malarious influences. [Footnote: The fact that the mixing of
salt and fresh water in coast marshes and lagoons is deleterious to the
sanitary condition of the vicinity, has been generally admitted, though the
precise reason why a mixture of both should be more injurious than either
alone, is not altogether clear. It has been suggested that the admission of
salt-water to the lagoons and rivers kills many fresh-water plants and
animals, while the fresh water is equally fatal to many marine organisms,
and that the decomposition of the remains originates poisonous minsmata.
Other theories, however, have been proposed. The whole subject is fully
and ably discussed by Dr. Salvagnoli Marchetti in the appendix to his
valuable Rapporto aul Bonificamento delle Maremme Toscane. See also the
Memorie Economico-Statistiche sulle Maremme Toscane, of the same
author. A different view of this subject is taken by Raffanini and Orlandini
in Analisi, Storico-Fisico-Economica sulli insolubrita nelle Maremme
Toscane, Firenze, 1869. See also the important memoir of D. Pantaleoni,
Del miasma vegetale e delle Malattie Miasmatiche, in which the views of
Salvagnoli on this point are combated.]
noblest, if not the most brilliant achievements of modern engineering, and,
regarded in all its bearings on the great question of which I have just
spoken, it is, as an example, of more importance to the general interests of
humanity than the proudest work of internal improvement that mechanical
means have yet constructed. The operations in the Val di Chiana have
consisted chiefly in so regulating the flow of the surface-waters into and
through it, as to compel them to deposit their sedimentary matter at the will
of the engineers, and thereby to raise grounds rendered insalubrious and
unfit for agricultural use by stagnating water; the improvements in the
Maremma have embraced both this method of elevating the level of the soil,
and the prevention of the mixture of salt-water with fresh in the coast
marshes and shallow bays, which is regarded as a very active cause of the
development of malarious influences. [Footnote: The fact that the mixing of
salt and fresh water in coast marshes and lagoons is deleterious to the
sanitary condition of the vicinity, has been generally admitted, though the
precise reason why a mixture of both should be more injurious than either
alone, is not altogether clear. It has been suggested that the admission of
salt-water to the lagoons and rivers kills many fresh-water plants and
animals, while the fresh water is equally fatal to many marine organisms,
and that the decomposition of the remains originates poisonous minsmata.
Other theories, however, have been proposed. The whole subject is fully
and ably discussed by Dr. Salvagnoli Marchetti in the appendix to his
valuable Rapporto aul Bonificamento delle Maremme Toscane. See also the
Memorie Economico-Statistiche sulle Maremme Toscane, of the same
author. A different view of this subject is taken by Raffanini and Orlandini
in Analisi, Storico-Fisico-Economica sulli insolubrita nelle Maremme
Toscane, Firenze, 1869. See also the important memoir of D. Pantaleoni,
Del miasma vegetale e delle Malattie Miasmatiche, in which the views of
Salvagnoli on this point are combated.]
Page 657
Improvements in the Tuscan Maremma.
In the improvements of the Tuscan Maremma, formidable difficulties
have been encountered. The territory to be reclaimed was extensive; the
salubrious places of retreat for laborers and inspectors were remote; the
courses of the rivers to be controlled were long and their natural inclination
not rapid; some of them, rising in wooded regions, transported
comparatively little earthy matter, [Footnote: This difficulty has been
remedied—though with doubtful general advantage—as to one important
river of the Maremma, the Pecora, by clearings recently executed along its
upper course. "The condition of this marsh and of its affluents are now,
November, 1859, much changed, and it is advisable to prosecute its
improvement by deposits. In consequence of the extensive felling of the
woods upon the plains, hills, and mountains of the territory of Massa and
Scarlino, within the last ten years, the Pecora and other affluents of the
marsh receive, during the rains, water abundantly charged with slime, so
that the deposits within the first division of the marsh are already
considerable, and we may now hope to see the whole marsh and pond filled
up in a much shorter time than we had a right to expect before 1850. This
circumstance totally changes the terms of the question, because the filling
of the marsh and pond, which then seemed almost impossible on account of
the small amount of sediment deposited by the Pecora, has now become
practicable."—Salvagnoli, Rapporto sul Bonificamento delle Maremme
Toscane, pp.li., lii.
Between 1830 and 1859 more than 36,000,000 cubic yards of sediment
were deposited in the marsh and shoal-water lake of Castiglione alone.—
Salvagnoli, Raccolta di Documenti, pp. 74, 75.] and above all, the coast,
which is a recent deposit of the waters, is little elevated above the sea, and
admits into its lagoons and the mouths of its rivers floods of salt-water with
every western wind, every rising tide. [Footnote: The tide rises ten inches
In the improvements of the Tuscan Maremma, formidable difficulties
have been encountered. The territory to be reclaimed was extensive; the
salubrious places of retreat for laborers and inspectors were remote; the
courses of the rivers to be controlled were long and their natural inclination
not rapid; some of them, rising in wooded regions, transported
comparatively little earthy matter, [Footnote: This difficulty has been
remedied—though with doubtful general advantage—as to one important
river of the Maremma, the Pecora, by clearings recently executed along its
upper course. "The condition of this marsh and of its affluents are now,
November, 1859, much changed, and it is advisable to prosecute its
improvement by deposits. In consequence of the extensive felling of the
woods upon the plains, hills, and mountains of the territory of Massa and
Scarlino, within the last ten years, the Pecora and other affluents of the
marsh receive, during the rains, water abundantly charged with slime, so
that the deposits within the first division of the marsh are already
considerable, and we may now hope to see the whole marsh and pond filled
up in a much shorter time than we had a right to expect before 1850. This
circumstance totally changes the terms of the question, because the filling
of the marsh and pond, which then seemed almost impossible on account of
the small amount of sediment deposited by the Pecora, has now become
practicable."—Salvagnoli, Rapporto sul Bonificamento delle Maremme
Toscane, pp.li., lii.
Between 1830 and 1859 more than 36,000,000 cubic yards of sediment
were deposited in the marsh and shoal-water lake of Castiglione alone.—
Salvagnoli, Raccolta di Documenti, pp. 74, 75.] and above all, the coast,
which is a recent deposit of the waters, is little elevated above the sea, and
admits into its lagoons and the mouths of its rivers floods of salt-water with
every western wind, every rising tide. [Footnote: The tide rises ten inches
Page 658
on the coast of Tuscany. See Memoir by Fantoni, in the appendix to
Salvagnoli, Rapporto, p. 189.
On the tides of the Mediterranean, see Bottger, Das Mittelmeer, p. 190.]
The western coast of Tuscany is not supposed to have been an unhealthy
region before the conquest of Etruria by the Romans, but it certainly
became so within a few centuries after that event. This was a natural
consequence of the neglect or wanton destruction of the public
improvements, and especially the hydraulic works in which the Etruscans
were so skilful, and of the felling of the upland forests, to satisfy the
demand for wood at Rome for domestic, industrial, and military purposes.
After the downfall of the Roman empire, the incursions of the barbarians,
and then feudalism, foreign domination, intestine wars, and temporal and
spiritual tyrannies, aggravated still more cruelly the moral and physical
evils which Tuscany and the other Italian States were doomed to suffer, and
from which they have enjoyed but brief respites during the whole period of
modern history. The Maremma was already proverbially unhealthy in the
time of Dante, who refers to the fact in several familiar passages, and the
petty tyrants upon its borders often sent criminals to places of confinement
in its territory, as a slow but certain mode of execution. Ignorance of the
causes of the insalubrity, and often the interference of private rights,
[Footnote: In Catholic countries, the discipline of the church requires a
meagre diet at certain seasons, and as fish is not flesh, there is a great
demand for that article of food at those periods. For the convenience of
monasteries and their patrons, and as a source of pecuniary emolument to
ecclesiastical establishments and sometimes to lay proprietors, great
numbers of artificial fish-ponds were created during the Middle Ages. They
were generally shallow pools formed by damming up the outlet of marshes,
and they were among the most fruitful sources of endemic disease, and of
the peculiar malignity of the epidemics which so often ravaged Europe in
Salvagnoli, Rapporto, p. 189.
On the tides of the Mediterranean, see Bottger, Das Mittelmeer, p. 190.]
The western coast of Tuscany is not supposed to have been an unhealthy
region before the conquest of Etruria by the Romans, but it certainly
became so within a few centuries after that event. This was a natural
consequence of the neglect or wanton destruction of the public
improvements, and especially the hydraulic works in which the Etruscans
were so skilful, and of the felling of the upland forests, to satisfy the
demand for wood at Rome for domestic, industrial, and military purposes.
After the downfall of the Roman empire, the incursions of the barbarians,
and then feudalism, foreign domination, intestine wars, and temporal and
spiritual tyrannies, aggravated still more cruelly the moral and physical
evils which Tuscany and the other Italian States were doomed to suffer, and
from which they have enjoyed but brief respites during the whole period of
modern history. The Maremma was already proverbially unhealthy in the
time of Dante, who refers to the fact in several familiar passages, and the
petty tyrants upon its borders often sent criminals to places of confinement
in its territory, as a slow but certain mode of execution. Ignorance of the
causes of the insalubrity, and often the interference of private rights,
[Footnote: In Catholic countries, the discipline of the church requires a
meagre diet at certain seasons, and as fish is not flesh, there is a great
demand for that article of food at those periods. For the convenience of
monasteries and their patrons, and as a source of pecuniary emolument to
ecclesiastical establishments and sometimes to lay proprietors, great
numbers of artificial fish-ponds were created during the Middle Ages. They
were generally shallow pools formed by damming up the outlet of marshes,
and they were among the most fruitful sources of endemic disease, and of
the peculiar malignity of the epidemics which so often ravaged Europe in
Page 659
those centuries. These ponds, in religious hands, were too sacred to be
infringed upon for sanitary purposes, and when belonging to powerful lay
lords they were almost an inviolable. The rights of fishery were a standing
obstacle to every proposal of hydralic improvement, and to this day large
and fertile districts in Southern Europe remain sickly and almost
unimproved and uninhabited, because the draining of the ponds upon them
would reduce the income of proprietors who derive large profits by
supplying the faithful, in Lent, with fish, and with various species of
waterfowl which, though very fat, are, ecclesiastically speaking,
meagre.]prevented the adoption of measures to remove it, and the growing
political and commercial importance of the large towns in more healthful
localities absorbed the attention of Government, and deprived the
Maremma of its just share in the systems of physical improvement which
were successfully adopted in interior and Northern Italy.
Before any serious attempts were made to drain or fill up the marshes of
the Maremma, various other sanitary experiments were tried. It was
generally believed that the insalubrity of the province was the consequence,
not the cause, of its depopulation, and that, if it were once densely
inhabited, the ordinary operations of agriculture, and especially the
maintenance of numerous domestic fires, would restore it to its ancient
healthfulness. [Footnote: Macchiavelli advised the Government of Tuscany
"to provide that men should restore the wholesomeness of the soil by
cultivation, and purify the air by fires."—Salvagnoli, Memorie, p. 111.] In
accordance with these views, settlers were invited from various parts of
Italy, from Greece, and, after the accession of the Lorraine princes, from
that country also, and colonized in the Maremma. To strangers coming from
soils and skies so unlike those of the Tuscan marshes, the climate was more
fatal than to the inhabitants of the neighboring districts, whose constitutions
had become in some degree inured to the local influences, or who at least
knew better how to guard against them. The consequence very naturally
infringed upon for sanitary purposes, and when belonging to powerful lay
lords they were almost an inviolable. The rights of fishery were a standing
obstacle to every proposal of hydralic improvement, and to this day large
and fertile districts in Southern Europe remain sickly and almost
unimproved and uninhabited, because the draining of the ponds upon them
would reduce the income of proprietors who derive large profits by
supplying the faithful, in Lent, with fish, and with various species of
waterfowl which, though very fat, are, ecclesiastically speaking,
meagre.]prevented the adoption of measures to remove it, and the growing
political and commercial importance of the large towns in more healthful
localities absorbed the attention of Government, and deprived the
Maremma of its just share in the systems of physical improvement which
were successfully adopted in interior and Northern Italy.
Before any serious attempts were made to drain or fill up the marshes of
the Maremma, various other sanitary experiments were tried. It was
generally believed that the insalubrity of the province was the consequence,
not the cause, of its depopulation, and that, if it were once densely
inhabited, the ordinary operations of agriculture, and especially the
maintenance of numerous domestic fires, would restore it to its ancient
healthfulness. [Footnote: Macchiavelli advised the Government of Tuscany
"to provide that men should restore the wholesomeness of the soil by
cultivation, and purify the air by fires."—Salvagnoli, Memorie, p. 111.] In
accordance with these views, settlers were invited from various parts of
Italy, from Greece, and, after the accession of the Lorraine princes, from
that country also, and colonized in the Maremma. To strangers coming from
soils and skies so unlike those of the Tuscan marshes, the climate was more
fatal than to the inhabitants of the neighboring districts, whose constitutions
had become in some degree inured to the local influences, or who at least
knew better how to guard against them. The consequence very naturally
Page 660
was that the experiment totally failed to produce the desired effects, and
was attended with a great sacrifice of life and a heavy loss to the treasury of
the state.
The territory known as the Tuscan Maremma, ora maritime, or Maremme
—for the plural form is most generally used—lies upon and near the
western coast of Tuscany, and comprises about 1,900 square miles English,
of which 500 square miles, or 320,000 acres, are plain and marsh including
45,500 acres of water surface, and about 290,000 acres are forest. One of
the mountain peaks, that of Mount Amiata, rises to the height of 6,280 feet.
The mountains of the Maremma are healthy, the lower hills much less so, as
the malaria is felt at some points at the height of 1,000 feet, and the plains,
with the exception of a few localities favorably situated on the seacoast, are
in a high degree pestilential. The fixed population is about 80,000, of whom
one-sixth live on the plains in the winter and about one-tenth in the summer.
Nine or ten thousand laborers come down from the mountains of the
Maremma and the neighboring provinces into the plain, during the latter
season, to cultivate and gather the crops.
Out of this small number of inhabitants and strangers, 35,619 were ill
enough to require medical treatment between the 1st of June, 1840, and the
1st of June, 1841, and more than one-half the cases were of intermittent,
malignant, gastric, or catarrhal fever. Very few agricultural laborers escaped
fever, though the disease did not always manifest itself until they had
returned to the mountains. In the province of Grosseto, which embraces
nearly the whole of the Maremma, the annual mortality was 3.92 per cent.,
the average duration of life but 23.18 years, and 75 per cent. of the deaths
were among persons engaged in agriculture.
The filling up of the low grounds and the partial separation of the waters
of the sea and the land, which had been in progress since the year 1827,
was attended with a great sacrifice of life and a heavy loss to the treasury of
the state.
The territory known as the Tuscan Maremma, ora maritime, or Maremme
—for the plural form is most generally used—lies upon and near the
western coast of Tuscany, and comprises about 1,900 square miles English,
of which 500 square miles, or 320,000 acres, are plain and marsh including
45,500 acres of water surface, and about 290,000 acres are forest. One of
the mountain peaks, that of Mount Amiata, rises to the height of 6,280 feet.
The mountains of the Maremma are healthy, the lower hills much less so, as
the malaria is felt at some points at the height of 1,000 feet, and the plains,
with the exception of a few localities favorably situated on the seacoast, are
in a high degree pestilential. The fixed population is about 80,000, of whom
one-sixth live on the plains in the winter and about one-tenth in the summer.
Nine or ten thousand laborers come down from the mountains of the
Maremma and the neighboring provinces into the plain, during the latter
season, to cultivate and gather the crops.
Out of this small number of inhabitants and strangers, 35,619 were ill
enough to require medical treatment between the 1st of June, 1840, and the
1st of June, 1841, and more than one-half the cases were of intermittent,
malignant, gastric, or catarrhal fever. Very few agricultural laborers escaped
fever, though the disease did not always manifest itself until they had
returned to the mountains. In the province of Grosseto, which embraces
nearly the whole of the Maremma, the annual mortality was 3.92 per cent.,
the average duration of life but 23.18 years, and 75 per cent. of the deaths
were among persons engaged in agriculture.
The filling up of the low grounds and the partial separation of the waters
of the sea and the land, which had been in progress since the year 1827,
Page 661
now began to show very decided effects upon the sanitary condition of the
population. In the year ending June 1st, 1842, the number of the sick was
reduced by more than 2,000, and the cases of fever by more than 4,000. The
next year the cases of fever fell to 10,500, and in that ending June 1st, 1844,
to 9,200. The political events of 1848, and the preceding and following
years, occasioned the suspension of the works of improvement in the
Maremma, but they were resumed after the revolution of 1859. I have
spoken with some detail of the improvements in the Tuscan Maremma,
because of their great relative importance, and because their history is well
known; but like operations have been executed in the territory of Pisa and
upon the coast of the duchy of Lucca. In the latter case they were confined
principally to prevention of the intermixing of fresh water with that of the
sea. In 1741 sluices or lock-gates were constructed for this purpose, and the
following year the fevers, which had been destructive to the coast
population for a long time previous, disappeared altogether. In 1768 and
1769, the works having fallen to decay, the fevers returned in a very
malignant form, but the rebuilding of the gates again restored the
healthfulness of the shore. Similar facts recurred in 1784 and 1785, and
again from 1804 to 1821. This long and repeated experience has at last
impressed upon the people the necessity of vigilant attention to the sluices,
which are now kept in constant repair. The health of the coast is
uninterrupted, and Viareggio, the capital town of the district, is now much
frequented for its sea-baths and its general salubrity, at a season when
formerly it was justly shunned as the abode of disease and death. [Footnote:
Giorgini, Sur les causes de l'Insalubrite de l'air dans le voisinage des marais,
etc., lue a l'Academie des Sciences a Paris, le 12 Juillet, 1825. Reprinted in
Salvagnoli, Rapporto, etc., appendice, p. 5, et seqq.]
Improvements in the Val di Chiana.
population. In the year ending June 1st, 1842, the number of the sick was
reduced by more than 2,000, and the cases of fever by more than 4,000. The
next year the cases of fever fell to 10,500, and in that ending June 1st, 1844,
to 9,200. The political events of 1848, and the preceding and following
years, occasioned the suspension of the works of improvement in the
Maremma, but they were resumed after the revolution of 1859. I have
spoken with some detail of the improvements in the Tuscan Maremma,
because of their great relative importance, and because their history is well
known; but like operations have been executed in the territory of Pisa and
upon the coast of the duchy of Lucca. In the latter case they were confined
principally to prevention of the intermixing of fresh water with that of the
sea. In 1741 sluices or lock-gates were constructed for this purpose, and the
following year the fevers, which had been destructive to the coast
population for a long time previous, disappeared altogether. In 1768 and
1769, the works having fallen to decay, the fevers returned in a very
malignant form, but the rebuilding of the gates again restored the
healthfulness of the shore. Similar facts recurred in 1784 and 1785, and
again from 1804 to 1821. This long and repeated experience has at last
impressed upon the people the necessity of vigilant attention to the sluices,
which are now kept in constant repair. The health of the coast is
uninterrupted, and Viareggio, the capital town of the district, is now much
frequented for its sea-baths and its general salubrity, at a season when
formerly it was justly shunned as the abode of disease and death. [Footnote:
Giorgini, Sur les causes de l'Insalubrite de l'air dans le voisinage des marais,
etc., lue a l'Academie des Sciences a Paris, le 12 Juillet, 1825. Reprinted in
Salvagnoli, Rapporto, etc., appendice, p. 5, et seqq.]
Improvements in the Val di Chiana.
Page 662
For twenty miles or more after the remotest headwaters of the Arno have
united to form a considerable stream, this river flows south-eastwards to the
vicinity of Arezzo. It here sweeps round to the north-west, and follows that
course to near its junction with the Sieve, a few miles above Florence, from
which point its general direction is westward to the sea. From the bend at
Arezzo, a depression called the Val di Chiana runs south-eastwards until it
strikes into the valley of the Paglia, a tributary of the Tiber, and thus
connects the basin of the latter river with that of the Arno. In the Middle
Ages, and down to the eighteenth century, the Val di Chiana was often
overflowed and devastated by the torrents which poured down from the
highlands, transporting great quantities of slime with their currents,
stagnating upon its surface, and gradually converting it into a marshy and
unhealthy district, which was at last very greatly reduced in population and
productiveness. It had, in fact, become so desolate that even the swallow
had deserted it. [Footnote: This curious fact is thus stated in the preface to
Fossombroni (Memorie sopra la Val di Chiana, edition of 1835, p. xiii.),
from which also I borrow most of the data hereafter given with respect to
that valley: "It is perhaps not universally known, that the swallows, which
come from the north [south] to spend the summer in our climate, do not
frequent marshy districts with a malarious atmosphere. A proof of the
restoration of salubrity in the Val di Chiana is furnished by these aerial
visitors, which had never before been seen in those low grounds, but which
have appeared within a few years at Forano and other points similarly
situated."
Is the air of swamps destructive to the swallows, or is their absence in
such localities merely due to the want of human habitations, near which this
half-domestic bird loves to breed, perhaps because the house-fly and other
insects which follow man are found only in the vicinity of his dwellings In
almoust all European countries the swallow is protected, by popular opinion
or superstition, from the persecution to which almost all other birds are
united to form a considerable stream, this river flows south-eastwards to the
vicinity of Arezzo. It here sweeps round to the north-west, and follows that
course to near its junction with the Sieve, a few miles above Florence, from
which point its general direction is westward to the sea. From the bend at
Arezzo, a depression called the Val di Chiana runs south-eastwards until it
strikes into the valley of the Paglia, a tributary of the Tiber, and thus
connects the basin of the latter river with that of the Arno. In the Middle
Ages, and down to the eighteenth century, the Val di Chiana was often
overflowed and devastated by the torrents which poured down from the
highlands, transporting great quantities of slime with their currents,
stagnating upon its surface, and gradually converting it into a marshy and
unhealthy district, which was at last very greatly reduced in population and
productiveness. It had, in fact, become so desolate that even the swallow
had deserted it. [Footnote: This curious fact is thus stated in the preface to
Fossombroni (Memorie sopra la Val di Chiana, edition of 1835, p. xiii.),
from which also I borrow most of the data hereafter given with respect to
that valley: "It is perhaps not universally known, that the swallows, which
come from the north [south] to spend the summer in our climate, do not
frequent marshy districts with a malarious atmosphere. A proof of the
restoration of salubrity in the Val di Chiana is furnished by these aerial
visitors, which had never before been seen in those low grounds, but which
have appeared within a few years at Forano and other points similarly
situated."
Is the air of swamps destructive to the swallows, or is their absence in
such localities merely due to the want of human habitations, near which this
half-domestic bird loves to breed, perhaps because the house-fly and other
insects which follow man are found only in the vicinity of his dwellings In
almoust all European countries the swallow is protected, by popular opinion
or superstition, from the persecution to which almost all other birds are
Page 663
subject. It is possible that this respect for the swallow is founded upon
ancient observation of the fact just stated on the authority of Fossombroni.
Ignorance mistakes the effect for the cause, and the absence of this bird may
have been supposed to be the occasion, not the consequence, of the
unhealthiness of particular localities. This opinion once adopted, the
swallow would become a sacred bird, and in process of time fables and
legends would be invented to give additional sanction to the prejudices
which protected it. The Romans considered the swallow as consecrated to
the Penates, or household gods, and according to Peretti (Le Serate del
Villaggio, p. 168) the Lombard peasantry think it a sin to kill them, because
they are le gallinelle del Signore, the chickens of the Lord.]
The bed of the Arno near Arezzo and that of the Paglia at the southern
extremity of the Val di Chiana did not differ much in level. The general
inclination of the valley was therefore small; it does not appear to have ever
been divided into opposite slopes by a true watershed, and the position of
the summit seems to have shifted according to the varying amount and
place of deposit of the sediment brought down by the lateral streams which
emptied into it. The length of its principal channel of drainage, and even the
direction of its flow at any given point, were therefore fluctuating. Hence,
much difference of opinion was entertained at different times with regard to
the normal course of this stream, and, consequently, to the question whether
it was to be regarded as properly an affluent of the Tiber or of the Arno.
The bed of the latter river at the bend has been eroded to the depth of
thirty or forty feet, and that, apparently, at no very remote period.
[Footnote: Able geologists infer from recent investigations, that, although
the Arno flowed to the south within the pliocenic period, the direction of its
course was changed at an earlier epoch than that supposed in the text.] If it
were elevated to what was evidently original height, the current of the Arno
would be so much above that of the Paglia as to allow of a regular flow
ancient observation of the fact just stated on the authority of Fossombroni.
Ignorance mistakes the effect for the cause, and the absence of this bird may
have been supposed to be the occasion, not the consequence, of the
unhealthiness of particular localities. This opinion once adopted, the
swallow would become a sacred bird, and in process of time fables and
legends would be invented to give additional sanction to the prejudices
which protected it. The Romans considered the swallow as consecrated to
the Penates, or household gods, and according to Peretti (Le Serate del
Villaggio, p. 168) the Lombard peasantry think it a sin to kill them, because
they are le gallinelle del Signore, the chickens of the Lord.]
The bed of the Arno near Arezzo and that of the Paglia at the southern
extremity of the Val di Chiana did not differ much in level. The general
inclination of the valley was therefore small; it does not appear to have ever
been divided into opposite slopes by a true watershed, and the position of
the summit seems to have shifted according to the varying amount and
place of deposit of the sediment brought down by the lateral streams which
emptied into it. The length of its principal channel of drainage, and even the
direction of its flow at any given point, were therefore fluctuating. Hence,
much difference of opinion was entertained at different times with regard to
the normal course of this stream, and, consequently, to the question whether
it was to be regarded as properly an affluent of the Tiber or of the Arno.
The bed of the latter river at the bend has been eroded to the depth of
thirty or forty feet, and that, apparently, at no very remote period.
[Footnote: Able geologists infer from recent investigations, that, although
the Arno flowed to the south within the pliocenic period, the direction of its
course was changed at an earlier epoch than that supposed in the text.] If it
were elevated to what was evidently original height, the current of the Arno
would be so much above that of the Paglia as to allow of a regular flow
Page 664
from its channel to the latter stream, through the Val di Chiana, provided the
bed of the valley had remained at the level which excavations prove it to
have had a few centuries ago, before it was raised by the deposits I have
mentioned. These facts, together with the testimony of ancient geographers
which scarcely admits of any other explanation, are thought to prove that all
the waters of the Upper Arno were originally discharged through the Val di
Chiana into the Tiber, and that a part of them still continued to flow, at least
occasionally, in that direction down to the days of the Roman empire, and
perhaps for some time later. The depression of the bed of the Arno, and the
raising of that of the valley by the deposits of the lateral torrents, finally cut
off the branch of the river which had flowed to the Tiber, and all its waters
were turned into its present channel, though the drainage of the principal
part of the Val di Chiana appears to have been in a south-eastwardly
direction until within a comparatively recent period.
In the sixteenth century the elevation of the bed of the valley had become
so considerable, that in 1551, at a point about ten miles south of the Arno, it
was found to be not less than one hundred and thirty feet above that river;
then followed a level of ten miles, and then a continuous descent to the
Paglia. Along the level portion of the valley was a boatable channel, and
lakes, sometimes a mile or even two miles in breadth, had formed at various
points farther south. At this period the drainage of the summit level might
easily have been determined in either direction, and the opposite descents of
the valley made to culminate at the north or at the south end of the level. In
the former case, the watershed would have been ten miles south of the
Arno; in the latter, twenty miles, and the division of the valley into two
opposite slopes would have been not very unequal.
Various schemes were suggested at this time for drawing off the stagnant
waters, as well as for the future regular drainage of the valley, and small
operations for those purposes were undertaken with partial success; but it
bed of the valley had remained at the level which excavations prove it to
have had a few centuries ago, before it was raised by the deposits I have
mentioned. These facts, together with the testimony of ancient geographers
which scarcely admits of any other explanation, are thought to prove that all
the waters of the Upper Arno were originally discharged through the Val di
Chiana into the Tiber, and that a part of them still continued to flow, at least
occasionally, in that direction down to the days of the Roman empire, and
perhaps for some time later. The depression of the bed of the Arno, and the
raising of that of the valley by the deposits of the lateral torrents, finally cut
off the branch of the river which had flowed to the Tiber, and all its waters
were turned into its present channel, though the drainage of the principal
part of the Val di Chiana appears to have been in a south-eastwardly
direction until within a comparatively recent period.
In the sixteenth century the elevation of the bed of the valley had become
so considerable, that in 1551, at a point about ten miles south of the Arno, it
was found to be not less than one hundred and thirty feet above that river;
then followed a level of ten miles, and then a continuous descent to the
Paglia. Along the level portion of the valley was a boatable channel, and
lakes, sometimes a mile or even two miles in breadth, had formed at various
points farther south. At this period the drainage of the summit level might
easily have been determined in either direction, and the opposite descents of
the valley made to culminate at the north or at the south end of the level. In
the former case, the watershed would have been ten miles south of the
Arno; in the latter, twenty miles, and the division of the valley into two
opposite slopes would have been not very unequal.
Various schemes were suggested at this time for drawing off the stagnant
waters, as well as for the future regular drainage of the valley, and small
operations for those purposes were undertaken with partial success; but it
Page 665
was feared that the discharge of the accumulated waters into the Tiber
would produce a dangerous inundation, while the diversion of the drainage
into the Arno would increase the violence of the floods to which that river
was very subject, and no decisive steps were taken. In 1606 an engineer,
whose name has not been preserved, proposed, as the only possible method
of improvement, the piercing of a tunnel through the hills bounding the
valley on the west to convey its waters to the Ombrone, but the expense and
other objections prevented the adoption of this scheme. [Footnote: Morozzi,
Dello stato dell' Arno, ii., pp. 39, 40.] The fears of the Roman Government
for the safety of the basin of the Tiber had induced it to construct
embankments across the portion of the valley lying within its territory, and
these obstructions, though not specifically intended for that purpose,
naturally promoted the deposit of sediment and the elevation of the bed of
the valley in their neighborhood. The effect of this measure and of the
continued spontaneous action of the torrents was, that the northern slope,
which in 1551 had commenced at the distance of ten miles from the Arno,
was found in 1605 to begin nearly thirty miles south of that river, and in
1645 it had been removed about six miles farther in the same direction.
[Footnote: Morozzi, Dello stato, etc., dell' Arno, ii., pp. 39, 40.]
In the seventeenth century the Tuscan and Papal Governments consulted
Galileo, Torricelli, Castelli, Cassini, Viviani, and other distinguished
philosophers and engineers, on the possibility of reclaiming the valley by a
regular artificial drainage. Most of these eminent physicists were of opinion
that the measure was impracticable, though not altogether for the same
reasons; but they seem to have agreed in thinking that the opening of such
channels, in either direction, as would give the current a flow sufficiently
rapid to drain the lands properly, would dangerously augment the
inundations of the river—whether the Tiber or the Arno—into which the
waters should be turned. The general improvement of the valley was now
for a long time abandoned, and the waters were allowed to spread and
would produce a dangerous inundation, while the diversion of the drainage
into the Arno would increase the violence of the floods to which that river
was very subject, and no decisive steps were taken. In 1606 an engineer,
whose name has not been preserved, proposed, as the only possible method
of improvement, the piercing of a tunnel through the hills bounding the
valley on the west to convey its waters to the Ombrone, but the expense and
other objections prevented the adoption of this scheme. [Footnote: Morozzi,
Dello stato dell' Arno, ii., pp. 39, 40.] The fears of the Roman Government
for the safety of the basin of the Tiber had induced it to construct
embankments across the portion of the valley lying within its territory, and
these obstructions, though not specifically intended for that purpose,
naturally promoted the deposit of sediment and the elevation of the bed of
the valley in their neighborhood. The effect of this measure and of the
continued spontaneous action of the torrents was, that the northern slope,
which in 1551 had commenced at the distance of ten miles from the Arno,
was found in 1605 to begin nearly thirty miles south of that river, and in
1645 it had been removed about six miles farther in the same direction.
[Footnote: Morozzi, Dello stato, etc., dell' Arno, ii., pp. 39, 40.]
In the seventeenth century the Tuscan and Papal Governments consulted
Galileo, Torricelli, Castelli, Cassini, Viviani, and other distinguished
philosophers and engineers, on the possibility of reclaiming the valley by a
regular artificial drainage. Most of these eminent physicists were of opinion
that the measure was impracticable, though not altogether for the same
reasons; but they seem to have agreed in thinking that the opening of such
channels, in either direction, as would give the current a flow sufficiently
rapid to drain the lands properly, would dangerously augment the
inundations of the river—whether the Tiber or the Arno—into which the
waters should be turned. The general improvement of the valley was now
for a long time abandoned, and the waters were allowed to spread and
Page 666
stagnate until carried off by partial drainage, infiltration, and evaporation.
Torricelli had contended that the slope of a large part of the valley was too
small to allow it to be drained by ordinary methods, and that no practicable
depth and width of canal would suffice for that purpose. It could be laid dry,
he thought, only by converting its surface into an inclined plane, and he
suggested that this might be accomplished by controlling the flow of the
numerous torrents which pour into it, so as to force them to deposit their
sediment at the pleasure of the engineer, and, consequently, to elevate the
level of the area over which it should be spread. [Footnote: Torricelli thus
expressed himself on this point: "If we content ourselves with what nature
has made practicable to human industry, we shall endeavor to control, as far
as possible, the outlets of these streams, which, by raising the bed of the
valley with their deposits, will realize the fable of the Tagus and the
Pactolus, and truly roll golden sands for him that is wise enough to avail
himself of them."—Fossombroni, Memoris sopra la Val di China, p. 219.]
This plan did not meet with immediate general acceptance, but it was soon
adopted for local purposes at some points in the southern part of the valley,
and it gradually grew in public favor and was extended in application until
its final triumph a hundred years later.
In spite of these encouraging successes, however, the fear of danger to
the valley of the Arno and the Tiber, and the difficulty of an agreement
between Tuscany and Rome—the boundary between which states crossed
the Val di Chiana not far from the half-way point between the two rivers—
and of reconciling other conflicting interests, prevented the resumption of
the projects for the general drainage of the valley until after the middle of
the eighteenth century. In the meantime the science of hydraulics had
become better understood, and the establishment of the natural law
according to which the velocity of a current of water, and of course the
proportional quantity discharged by it in a given time, are increased by
increasing its mass, had diminished if not dissipated the fear of exposing the
Torricelli had contended that the slope of a large part of the valley was too
small to allow it to be drained by ordinary methods, and that no practicable
depth and width of canal would suffice for that purpose. It could be laid dry,
he thought, only by converting its surface into an inclined plane, and he
suggested that this might be accomplished by controlling the flow of the
numerous torrents which pour into it, so as to force them to deposit their
sediment at the pleasure of the engineer, and, consequently, to elevate the
level of the area over which it should be spread. [Footnote: Torricelli thus
expressed himself on this point: "If we content ourselves with what nature
has made practicable to human industry, we shall endeavor to control, as far
as possible, the outlets of these streams, which, by raising the bed of the
valley with their deposits, will realize the fable of the Tagus and the
Pactolus, and truly roll golden sands for him that is wise enough to avail
himself of them."—Fossombroni, Memoris sopra la Val di China, p. 219.]
This plan did not meet with immediate general acceptance, but it was soon
adopted for local purposes at some points in the southern part of the valley,
and it gradually grew in public favor and was extended in application until
its final triumph a hundred years later.
In spite of these encouraging successes, however, the fear of danger to
the valley of the Arno and the Tiber, and the difficulty of an agreement
between Tuscany and Rome—the boundary between which states crossed
the Val di Chiana not far from the half-way point between the two rivers—
and of reconciling other conflicting interests, prevented the resumption of
the projects for the general drainage of the valley until after the middle of
the eighteenth century. In the meantime the science of hydraulics had
become better understood, and the establishment of the natural law
according to which the velocity of a current of water, and of course the
proportional quantity discharged by it in a given time, are increased by
increasing its mass, had diminished if not dissipated the fear of exposing the
Page 667
banks of the Arno to greater danger from inundations by draining the Val di
China into it. The suggestion of Torricelli was finally adopted as the basis
of a comprehensive system of improvement, and it was decided to continue
and extend the inversion of the original flow of the waters, and to turn them
into the Arno from a point as far to the south as should be found practicable.
The conduct of the works was committed to a succession of able engineers
who, for a long series of years, were under the general direction of the
celebrated philosopher and statesman Fossombroni, and the success has
fully justified the expectations of the most sanguine advocates of the
scheme. The plan of improvement embraced two branches: the one, the
removal of obstructions in the bed of the Arno, and, consequently, the
further depression of the channel of that river, in certain places, with the
view of increasing the rapidity of its current; the other, the gradual filling up
of the ponds and swamps, and raising of the lower grounds of the Val di
Chiana, by directing to convenient points the flow of the streams which
pour down into it, and there confining their waters by temporary dams until
the sediment was deposited where it was needed. The economical result of
these operations has been, that in 1835 an area of more than four hundred
and fifty square miles of pond, marsh, and damp, sickly low grounds had
been converted into fertile, healthy, and well-drained soil, and,
consequently, that so much territory has been added to the agricultural
domain of Tuscany. But in our present view of the subject, the geographical
revolution which has been accomplished is still more interesting. The
climatic influence of the elevation and draining of the soil must have been
considerable, though I do not know that an increase or a diminution of the
mean temperature or precipitation in the valley has been established by
meteorological observation. There is, however, in the improvement of the
sanitary condition of the Val di Chiana, which was formerly extremely
unhealthy, satisfactory proof of a beneficial climatic change. The fevers,
which not only decimated the population of the low grounds but infested
China into it. The suggestion of Torricelli was finally adopted as the basis
of a comprehensive system of improvement, and it was decided to continue
and extend the inversion of the original flow of the waters, and to turn them
into the Arno from a point as far to the south as should be found practicable.
The conduct of the works was committed to a succession of able engineers
who, for a long series of years, were under the general direction of the
celebrated philosopher and statesman Fossombroni, and the success has
fully justified the expectations of the most sanguine advocates of the
scheme. The plan of improvement embraced two branches: the one, the
removal of obstructions in the bed of the Arno, and, consequently, the
further depression of the channel of that river, in certain places, with the
view of increasing the rapidity of its current; the other, the gradual filling up
of the ponds and swamps, and raising of the lower grounds of the Val di
Chiana, by directing to convenient points the flow of the streams which
pour down into it, and there confining their waters by temporary dams until
the sediment was deposited where it was needed. The economical result of
these operations has been, that in 1835 an area of more than four hundred
and fifty square miles of pond, marsh, and damp, sickly low grounds had
been converted into fertile, healthy, and well-drained soil, and,
consequently, that so much territory has been added to the agricultural
domain of Tuscany. But in our present view of the subject, the geographical
revolution which has been accomplished is still more interesting. The
climatic influence of the elevation and draining of the soil must have been
considerable, though I do not know that an increase or a diminution of the
mean temperature or precipitation in the valley has been established by
meteorological observation. There is, however, in the improvement of the
sanitary condition of the Val di Chiana, which was formerly extremely
unhealthy, satisfactory proof of a beneficial climatic change. The fevers,
which not only decimated the population of the low grounds but infested
Page 668
the adjacent hills, have ceased their ravages, and are now not more frequent
than in other parts of Tuscany. The strictly topographical effect of the
operations in question, besides the conversion of marsh into dry surface, has
been the inversion of the inclination of the valley for a distance of thirty-
five miles, so that this great plain which, within a comparatively short
period, sloped and drained its waters to the south, now inclines and sends its
drainage to the north. The reversal of the currents of the valley has added to
the Arno a new tributary equal to the largest of its former affluents, and a
most important circumstance connected with this latter fact is, that the
increase of the volume of its waters has accelerated their velocity in a still
greater proportion, and, instead of augmenting the danger from its
inundations, has almost wholly obviated that source of apprehension.
[Footnote: Arrian observes that at the junction of the Hydaspes and the
Acesines, both of which are described as wide streams, "one very narrow
river is formed of two confluents, and its current is very swift."—Arrian,
Alex. Anab., vi., 4.
A like example is observed in the Anapus near Syracuse, which, below
the junction of its two branches, is narrower, though swifter than either of
them, and such cases are by no means unfrequent. The immediate effect of
the confluence of two rivers upon the current below depends upon local
circumstances, and especially upon the angle of incidence. If the two nearly
coincide in direction, so as to include a small angle, the join current will
have a greater velocity than the slower confluent, perhaps even than either
of them. If the two rivers run in transverse, still more if they flow in more
or less opposite, directions, the velocity of the principal branch will be
retarded both above and below the junction, and at high water it may even
set back the current of the affluent.
On the other hand, the diversion of a considerable branch from a river
retards its velocity below the point of separation, and here a deposit of earth
than in other parts of Tuscany. The strictly topographical effect of the
operations in question, besides the conversion of marsh into dry surface, has
been the inversion of the inclination of the valley for a distance of thirty-
five miles, so that this great plain which, within a comparatively short
period, sloped and drained its waters to the south, now inclines and sends its
drainage to the north. The reversal of the currents of the valley has added to
the Arno a new tributary equal to the largest of its former affluents, and a
most important circumstance connected with this latter fact is, that the
increase of the volume of its waters has accelerated their velocity in a still
greater proportion, and, instead of augmenting the danger from its
inundations, has almost wholly obviated that source of apprehension.
[Footnote: Arrian observes that at the junction of the Hydaspes and the
Acesines, both of which are described as wide streams, "one very narrow
river is formed of two confluents, and its current is very swift."—Arrian,
Alex. Anab., vi., 4.
A like example is observed in the Anapus near Syracuse, which, below
the junction of its two branches, is narrower, though swifter than either of
them, and such cases are by no means unfrequent. The immediate effect of
the confluence of two rivers upon the current below depends upon local
circumstances, and especially upon the angle of incidence. If the two nearly
coincide in direction, so as to include a small angle, the join current will
have a greater velocity than the slower confluent, perhaps even than either
of them. If the two rivers run in transverse, still more if they flow in more
or less opposite, directions, the velocity of the principal branch will be
retarded both above and below the junction, and at high water it may even
set back the current of the affluent.
On the other hand, the diversion of a considerable branch from a river
retards its velocity below the point of separation, and here a deposit of earth
Page 669
in its channel immediately begins, which has a tendency to turn the whole
stream into the new bed. "Theory and the authority of all hydrographical
writers combine to show that the channels of rivers undergo an elevation of
bed below a canal of diversion."—Letter of Fossombroni, in Salvagnoli,
Raccolta di Documenti, p. 32. See the early authorities and discussions on
the principle stated in the text, in Frisi, Del modo di regolare i Fiumi e i
Torrenti, libro iii., capit. i., and Mongotti, Idraulica, ii., pp. 88 et seqq., and
see p. 498, note, ante.
In my account of these improvements I have chiefly followed
Fossombroni, under whose direction they were principally executed. Many
of Fossombroni's statements and opinions have been controverted, and in
comparatively unimportant particulars they have been shown to be
erroneous.—See Lombardini, Guida allo studio dell' Idrologia, cap. xviii.,
and same author, Esame degli Studi sul Tevere, Section 33.]
Between the beginning of the fifteenth century and the year 1761, thirty-
one destructive floods of the Arno are recorded; between 1761, when the
principal streams of the Val di Chiana were diverted into that river, and
1835, not one. [Footnote: Fossombroni, Memorie Idraulico-storiche,
Introduzione, p. xvi. Between the years 1700 and 1799 the chroniclers
record seventeen floods of the Arno, and twenty between 1800 and 1870,
but none of these were of a properly destructive character except those in
1844, 1864, and 1870, and the ravages of this latter were chiefly confined to
Pisa, and were occasioned by the bursting of a dike or wall. They are all
three generally ascribed to extraordinary, if not unprecedented, rains and
snows, but many inquirers attribute them to the felling of the woods in the
valleys of the upper tributaries of the Arno since 1835. See a paper by
Griffini, in the Italia Nuova, 18 Marzo, 1871.]
Results of Operations.
stream into the new bed. "Theory and the authority of all hydrographical
writers combine to show that the channels of rivers undergo an elevation of
bed below a canal of diversion."—Letter of Fossombroni, in Salvagnoli,
Raccolta di Documenti, p. 32. See the early authorities and discussions on
the principle stated in the text, in Frisi, Del modo di regolare i Fiumi e i
Torrenti, libro iii., capit. i., and Mongotti, Idraulica, ii., pp. 88 et seqq., and
see p. 498, note, ante.
In my account of these improvements I have chiefly followed
Fossombroni, under whose direction they were principally executed. Many
of Fossombroni's statements and opinions have been controverted, and in
comparatively unimportant particulars they have been shown to be
erroneous.—See Lombardini, Guida allo studio dell' Idrologia, cap. xviii.,
and same author, Esame degli Studi sul Tevere, Section 33.]
Between the beginning of the fifteenth century and the year 1761, thirty-
one destructive floods of the Arno are recorded; between 1761, when the
principal streams of the Val di Chiana were diverted into that river, and
1835, not one. [Footnote: Fossombroni, Memorie Idraulico-storiche,
Introduzione, p. xvi. Between the years 1700 and 1799 the chroniclers
record seventeen floods of the Arno, and twenty between 1800 and 1870,
but none of these were of a properly destructive character except those in
1844, 1864, and 1870, and the ravages of this latter were chiefly confined to
Pisa, and were occasioned by the bursting of a dike or wall. They are all
three generally ascribed to extraordinary, if not unprecedented, rains and
snows, but many inquirers attribute them to the felling of the woods in the
valleys of the upper tributaries of the Arno since 1835. See a paper by
Griffini, in the Italia Nuova, 18 Marzo, 1871.]
Results of Operations.
Page 670
It is now a hundred years since the commencement of the improvements
in the Val di Chiana, and those of the Maremma have been in more or less
continued operation for above a generation. They have, as we have seen,
produced important geographical changes in the surface of the earth and in
the flow of considerable rivers, and their effects have been not less
conspicuous in preventing other changes, of a more or less deleterious
character, which would infallibly have taken place if they had not been
arrested by the improvements in question.
The sediment washed into the marshes of the Maremma is not less than
12,000,000 cubic yards per annum. The escape of this quantity into the sea,
which, is now almost wholly prevented, would be sufficient to advance the
coast-line fourteen yards per year, for a distance of forty miles, computing
the mean depth of the sea near the shore at twelve yards. It is true that in
this case, as well as in that of other rivers, the sedimentary matter would not
be distributed equally along the shore, and much of it would be carried out
into deep water, or perhaps transported by the currents to distant coasts. The
immediate effects of the deposit in the sea, therefore, would not be so
palpable as they appear in this numerical form, but they would be equally
certain, and would infallibly manifest themselves, first, perhaps, at some
remote point, and afterwards more energetically at or near the outlets of the
rivers which produced them. The elevation of the bottom of the sea would
diminish the inclination of the beds of the rivers discharging themselves
into it on that coast, and of course their tendency to overflow their banks
and extend still further the domain of the marshes which border them would
be increased in proportion.
It has been already stated that, in order to prevent the overflow of the
valley of the Tiber by freely draining the Val di Chiana into it, the Papal
authorities, long before the commencement of the Tuscan works,
constructed strong barriers near the southern end of the valley, which
in the Val di Chiana, and those of the Maremma have been in more or less
continued operation for above a generation. They have, as we have seen,
produced important geographical changes in the surface of the earth and in
the flow of considerable rivers, and their effects have been not less
conspicuous in preventing other changes, of a more or less deleterious
character, which would infallibly have taken place if they had not been
arrested by the improvements in question.
The sediment washed into the marshes of the Maremma is not less than
12,000,000 cubic yards per annum. The escape of this quantity into the sea,
which, is now almost wholly prevented, would be sufficient to advance the
coast-line fourteen yards per year, for a distance of forty miles, computing
the mean depth of the sea near the shore at twelve yards. It is true that in
this case, as well as in that of other rivers, the sedimentary matter would not
be distributed equally along the shore, and much of it would be carried out
into deep water, or perhaps transported by the currents to distant coasts. The
immediate effects of the deposit in the sea, therefore, would not be so
palpable as they appear in this numerical form, but they would be equally
certain, and would infallibly manifest themselves, first, perhaps, at some
remote point, and afterwards more energetically at or near the outlets of the
rivers which produced them. The elevation of the bottom of the sea would
diminish the inclination of the beds of the rivers discharging themselves
into it on that coast, and of course their tendency to overflow their banks
and extend still further the domain of the marshes which border them would
be increased in proportion.
It has been already stated that, in order to prevent the overflow of the
valley of the Tiber by freely draining the Val di Chiana into it, the Papal
authorities, long before the commencement of the Tuscan works,
constructed strong barriers near the southern end of the valley, which
Page 671
detained the waters of the wet season until they could be gradually drawn
off into the Paglia. They consequently deposited most of their sediment in
the Val di Chiana and carried down comparatively little earth to the Tiber.
The lateral streams contributing the largest quantities of sedimentary matter
to the Val di Chiana originally flowed into that valley near its northern end;
and the change of their channels and outlets in a southern direction, so as to
raise that part of the valley by their deposits and thereby reverse its
drainage, was one of the principal steps in the process of improvement.
We have seen that the north end of the Val di Chiana near the Arno had
been raised by spontaneous deposit of sediment to such a height as to
interpose a sufficient obstacle to all flow in that direction. If, then, the
Roman dam had not been erected, or the works of the Tuscan Government
undertaken, the whole of the earth, which has been arrested by those works
and employed to raise the bed and reverse the declivity of the valley, would
have been carried down to the Tiber and thence into the sea. The deposit
thus created would, of course, have contributed to increase the advance of
the shore at the mouth of that river, which has long been going on at the rate
of three metres and nine-tenths (twelve feet and nine inches) per annum.
[Footnote: See the careful estimates of Rozet, Moyens de forcer les
Torrents, etc., pp. 42, 44.] It is evident that a quantity of earth, sufficient to
effect the immense changes I have described in a wide valley more than
thirty miles long, if deposited at the outlet of the Tiber, would have very
considerably modified the outline of the coast, and have exerted no
unimportant influence on the flow of that river, by raising its point of
discharge and lengthening its channel.
The Coast of the Netherlands. It has been shown in a former section that
the dikes of the Netherlands and the adjacent states have protected a
considerable extent of coast from the encroachments of the sea, an have
won a large tract of cultivable land from the dominion of the ocean waters.
off into the Paglia. They consequently deposited most of their sediment in
the Val di Chiana and carried down comparatively little earth to the Tiber.
The lateral streams contributing the largest quantities of sedimentary matter
to the Val di Chiana originally flowed into that valley near its northern end;
and the change of their channels and outlets in a southern direction, so as to
raise that part of the valley by their deposits and thereby reverse its
drainage, was one of the principal steps in the process of improvement.
We have seen that the north end of the Val di Chiana near the Arno had
been raised by spontaneous deposit of sediment to such a height as to
interpose a sufficient obstacle to all flow in that direction. If, then, the
Roman dam had not been erected, or the works of the Tuscan Government
undertaken, the whole of the earth, which has been arrested by those works
and employed to raise the bed and reverse the declivity of the valley, would
have been carried down to the Tiber and thence into the sea. The deposit
thus created would, of course, have contributed to increase the advance of
the shore at the mouth of that river, which has long been going on at the rate
of three metres and nine-tenths (twelve feet and nine inches) per annum.
[Footnote: See the careful estimates of Rozet, Moyens de forcer les
Torrents, etc., pp. 42, 44.] It is evident that a quantity of earth, sufficient to
effect the immense changes I have described in a wide valley more than
thirty miles long, if deposited at the outlet of the Tiber, would have very
considerably modified the outline of the coast, and have exerted no
unimportant influence on the flow of that river, by raising its point of
discharge and lengthening its channel.
The Coast of the Netherlands. It has been shown in a former section that
the dikes of the Netherlands and the adjacent states have protected a
considerable extent of coast from the encroachments of the sea, an have
won a large tract of cultivable land from the dominion of the ocean waters.
Page 672
The immense results obtained from the operations of the Tuscan engineers
in the Val di Chiana, and the Maremma have suggested the question,
whether a different method of accomplishing these objects might not have
been adopted with advantage. It has been argued, as in the case of the Po,
that a system of transverse inland dikes and canals, upon the principle of
those which have been so successfully employed in the Val di Chiana and in
Egypt, might have elevated the low grounds above the ocean tides, by
spreading over them the sediment brought down by the Rhine, the Maes,
and the Scheld. If this process had been introduced in the Middle Ages, and
constantly pursued to our times, the superficial and coast geography, as well
as the hydrography of the countries in question, would undoubtedly have
presented an aspect very different from their present condition; and by
combining the process with a system of maritime dikes, which would have
been necessary, both to resist the advance of the sea and to retain the slime
deposited by river overflows, it is, indeed, possible that the territory of
those states would have been as extensive as it now is, and, at the same
time, somewhat elevated above its natural level.
The argument in favor of that method rests on the assumption that all the
sea-washed earth, which the tides have let fall upon the shallow coast of the
Netherlands, has been brought down by the rivers which empty upon those
shores, and could have been secured by allowing those rivers to spread over
the flats and deposit their sediment in still-water pools formed by cross-
dikes like those of Egypt.
But we are ignorant of the proportions in which the marine deposits that
form the soil of the polders have been derived from materials brought down
by these rivers, or from other more remote sources. Much of the river slime
has, no doubt, been transported by marine currents quite beyond the reach
of returning streams, and it is uncertain how far this loss has been balanced
in the Val di Chiana, and the Maremma have suggested the question,
whether a different method of accomplishing these objects might not have
been adopted with advantage. It has been argued, as in the case of the Po,
that a system of transverse inland dikes and canals, upon the principle of
those which have been so successfully employed in the Val di Chiana and in
Egypt, might have elevated the low grounds above the ocean tides, by
spreading over them the sediment brought down by the Rhine, the Maes,
and the Scheld. If this process had been introduced in the Middle Ages, and
constantly pursued to our times, the superficial and coast geography, as well
as the hydrography of the countries in question, would undoubtedly have
presented an aspect very different from their present condition; and by
combining the process with a system of maritime dikes, which would have
been necessary, both to resist the advance of the sea and to retain the slime
deposited by river overflows, it is, indeed, possible that the territory of
those states would have been as extensive as it now is, and, at the same
time, somewhat elevated above its natural level.
The argument in favor of that method rests on the assumption that all the
sea-washed earth, which the tides have let fall upon the shallow coast of the
Netherlands, has been brought down by the rivers which empty upon those
shores, and could have been secured by allowing those rivers to spread over
the flats and deposit their sediment in still-water pools formed by cross-
dikes like those of Egypt.
But we are ignorant of the proportions in which the marine deposits that
form the soil of the polders have been derived from materials brought down
by these rivers, or from other more remote sources. Much of the river slime
has, no doubt, been transported by marine currents quite beyond the reach
of returning streams, and it is uncertain how far this loss has been balanced
Page 673
by earth washed by the sea from distant shores and let fall on the coasts of
the Netherlands and other neighboring countries.
We know little or nothing of the quantity of solid matter brought down by
the rivers of Western Europe in early ages, but, as the banks of those rivers
are now generally better secured against wash and abrasion than in former
centuries, the sediment transported by them must be less than at periods
nearer the removal of the primitive forests of their valleys, though certainly
greater than it was before those forests were felled. Kladen informs us that
the sedimentary matter transported to the sea by the Rhine would amount to
a cubic geographical mile in five thousand years. [Footnote: Erdhunde, vol.
i, p. 384. The Mississippi—a river "undercharged with sediment"—with a
mean discharge of about ten times that of the Rhine, deposits a cubic
geographical mile in thirty-three years.] The proportion of this suspended
matter which, with our present means, could be arrested and precipitated
upon the ground, is almost infinitesimal, for only the surface-water, which
carries much less sediment than that at the bottom of the channel, would
flow over the banks, and as the movement of this water, if not checked
altogether, would be greatly retarded by the proposed cross-dikes, the
quantity of solid matter which would be conveyed to a given portion of land
during a single inundation would be extremely small. Inundations of the
Rhine occur but once or twice a year, and high water continues but a few
days, or even hours; the flood-tide of the sea happens seven hundred times
in a year, and at the turn of the tide the water is brought to almost absolute
rest. Hence, small as is the proportion of suspended matter in the tide-water,
the deposit probably amounts to far more in a year than would be let fall
upon the same area by the Rhine.
This argument, except as to the comparison between river and tide water,
applies to the Mississippi, the Po, and most other great rivers. Hence, until
that distant day when man shall devise means of extracting from rivers at
the Netherlands and other neighboring countries.
We know little or nothing of the quantity of solid matter brought down by
the rivers of Western Europe in early ages, but, as the banks of those rivers
are now generally better secured against wash and abrasion than in former
centuries, the sediment transported by them must be less than at periods
nearer the removal of the primitive forests of their valleys, though certainly
greater than it was before those forests were felled. Kladen informs us that
the sedimentary matter transported to the sea by the Rhine would amount to
a cubic geographical mile in five thousand years. [Footnote: Erdhunde, vol.
i, p. 384. The Mississippi—a river "undercharged with sediment"—with a
mean discharge of about ten times that of the Rhine, deposits a cubic
geographical mile in thirty-three years.] The proportion of this suspended
matter which, with our present means, could be arrested and precipitated
upon the ground, is almost infinitesimal, for only the surface-water, which
carries much less sediment than that at the bottom of the channel, would
flow over the banks, and as the movement of this water, if not checked
altogether, would be greatly retarded by the proposed cross-dikes, the
quantity of solid matter which would be conveyed to a given portion of land
during a single inundation would be extremely small. Inundations of the
Rhine occur but once or twice a year, and high water continues but a few
days, or even hours; the flood-tide of the sea happens seven hundred times
in a year, and at the turn of the tide the water is brought to almost absolute
rest. Hence, small as is the proportion of suspended matter in the tide-water,
the deposit probably amounts to far more in a year than would be let fall
upon the same area by the Rhine.
This argument, except as to the comparison between river and tide water,
applies to the Mississippi, the Po, and most other great rivers. Hence, until
that distant day when man shall devise means of extracting from rivers at
Page 674
flood, the whole volume of their suspended material and of depositing it at
the same time on their banks, the system of cross-dikes and COLMATAGE
must be limited to torrential streams transporting large proportions of
sediment, and to the rivers of hot countries, like the Nile, where the
saturation of the soil with water, and the securing of a supply for irrigation
afterwards, are the main objects, while raising the level of the banks is a
secondary consideration.
CHAPTER V.
THE SANDS.
Origin of Sand—Sand now Carried to the Sea—Beach Sands of Northern
Africa—Sands of Egypt—Sand Dunes and Sand Plains—Coast Dunes—
Sand
Banks—Character of Dune Sand—Interior Structure of Dunes—Geological
Importance of Dunes—Dunes on American Coasts—Dunes of Western
Europe—Age, Character, and Permanence of Dunes—Dunes as a Barrier
against the Sea—Encroachments of the Sea—Liimfjord—Coasts of
Schleswig-Holstein, Netherlands, and France—Movement of Dunes—
Control
of Dunes by Man—Inland Dunes—Inland Sand Plains.
Origin of Sand.
Sand, which is found in beds or strata at the bottom of the sea or in the
channels of rivers, as well as in extensive deposits upon or beneath the
the same time on their banks, the system of cross-dikes and COLMATAGE
must be limited to torrential streams transporting large proportions of
sediment, and to the rivers of hot countries, like the Nile, where the
saturation of the soil with water, and the securing of a supply for irrigation
afterwards, are the main objects, while raising the level of the banks is a
secondary consideration.
CHAPTER V.
THE SANDS.
Origin of Sand—Sand now Carried to the Sea—Beach Sands of Northern
Africa—Sands of Egypt—Sand Dunes and Sand Plains—Coast Dunes—
Sand
Banks—Character of Dune Sand—Interior Structure of Dunes—Geological
Importance of Dunes—Dunes on American Coasts—Dunes of Western
Europe—Age, Character, and Permanence of Dunes—Dunes as a Barrier
against the Sea—Encroachments of the Sea—Liimfjord—Coasts of
Schleswig-Holstein, Netherlands, and France—Movement of Dunes—
Control
of Dunes by Man—Inland Dunes—Inland Sand Plains.
Origin of Sand.
Sand, which is found in beds or strata at the bottom of the sea or in the
channels of rivers, as well as in extensive deposits upon or beneath the
Page 675
surface of the dry land, appears to consist essentially of the detritus of
rocks. It is not always by any means clear through what agency the solid
rock has been reduced to a granular condition; for there are beds of
quartzose sand, where the sharp, angular shape of the particles renders it
highly improbable that they have been formed by gradual abrasion and
attrition, and where the supposition of a crushing mechanical force seems
equally inadmissible. In common sand, the quartz grains are the most
numerous; but this is not a proof that the rocks from which these particles
were derived were wholly, or even chiefly, quartzose in character; for, in
many composite rocks, as, for example, in the granitic group, the mica,
feldspar, and hornblende are more easily decomposed by chemical action,
or disintegrated, comminuted, and reduced to an impalpable state by
mechanical force, than the quartz. In the destruction of such rocks,
therefore, the quartz would survive the other ingredients, and remain
unmixed, when they had been decomposed and recomposed into new
mineralogical or chemical combinations, or been ground to slime and
washed away by water currents.
The greater or less specific gravity of the different constituents of rock
doubtless aids in separating them into distinct masses when once
disintegrated, though there are veined and stratified beds of sand where the
difference between the upper and lower layers, in this respect, is too slight
to be supposed capable of effecting a complete separation. [Footnote: In the
curiously variegated sandstone of Arabia Petraea—which is certainly a
reaggregation of loose sand derived from disaggregation of older rocks—
the continuous veins frequently differ very widely in color, but not sensibly
in specific gravity or in texture; and the singular way in which they are now
alternated, now confusedly intermixed, must be explained otherwise than by
the weight of the respective grains which compose them. They seem, in
fact, to have been let fall by water in violent ebullition or tumultuous
mechanical agitation, or deposited by a succession of sudden aquatic or
rocks. It is not always by any means clear through what agency the solid
rock has been reduced to a granular condition; for there are beds of
quartzose sand, where the sharp, angular shape of the particles renders it
highly improbable that they have been formed by gradual abrasion and
attrition, and where the supposition of a crushing mechanical force seems
equally inadmissible. In common sand, the quartz grains are the most
numerous; but this is not a proof that the rocks from which these particles
were derived were wholly, or even chiefly, quartzose in character; for, in
many composite rocks, as, for example, in the granitic group, the mica,
feldspar, and hornblende are more easily decomposed by chemical action,
or disintegrated, comminuted, and reduced to an impalpable state by
mechanical force, than the quartz. In the destruction of such rocks,
therefore, the quartz would survive the other ingredients, and remain
unmixed, when they had been decomposed and recomposed into new
mineralogical or chemical combinations, or been ground to slime and
washed away by water currents.
The greater or less specific gravity of the different constituents of rock
doubtless aids in separating them into distinct masses when once
disintegrated, though there are veined and stratified beds of sand where the
difference between the upper and lower layers, in this respect, is too slight
to be supposed capable of effecting a complete separation. [Footnote: In the
curiously variegated sandstone of Arabia Petraea—which is certainly a
reaggregation of loose sand derived from disaggregation of older rocks—
the continuous veins frequently differ very widely in color, but not sensibly
in specific gravity or in texture; and the singular way in which they are now
alternated, now confusedly intermixed, must be explained otherwise than by
the weight of the respective grains which compose them. They seem, in
fact, to have been let fall by water in violent ebullition or tumultuous
mechanical agitation, or deposited by a succession of sudden aquatic or
Page 676
aerial currents flowing in different directions and charged with differently
colored matter.] In cases where rock has been reduced to sandy fragments
by heat, or by obscure chemical and other molecular forces, the sand-beds
may remain undisturbed, and represent, in the series of geological strata, the
solid formations from which they were derived. The large masses of sand
not found in place have been transported and accumulated by water or by
wind, the former being generally considered the most important of these
agencies; for the extensive deposits of the Sahara, of the Arabian
peninsulas, of the Llano Estacado and other North and South American
deserts, of the deserts of Persia, and of that of Gobi, are supposed to have
been swept together or distributed by marine currents, and to have been
elevated above the ocean by the same means as other upheaved strata.
Meteoric and mechanical influences are still active in the reduction of rocks
to a fragmentary state; [Footnote: A good account of the agencies now
operative in the reduction of rock to sand will be found in Winkler, Zand en
Duinen, Dockarm, 1865, pp. 4-20. I take this occasion to acknowledge my
obligations to this author for assuming the responsibility of many of the
errors I may have committed in this chapter, by translating a large part of it
from a former edition of the present work and publishing it as his own.] but
the quantity of sand now transported to the sea seems to be comparatively
inconsiderable, because—not to speak of the absence of diluvial action—
the number of torrents emptying directly into the sea is much less than it
was at earlier periods. The formation of alluvial plains in maritime bays, by
the sedimentary matter brought down from the mountains, has lengthened
the flow of such streams and converted them very generally into rivers, or
rather affluents of rivers of later geographical origin than themselves. The
filling up of the estuaries has so reduced the slope of all large and many
small rivers, and, consequently, so checked the current of what the Germans
call their Unterlauf, or lower course, that they are much less able to
transport heavy material than at earlier epochs. The slime deposited by
colored matter.] In cases where rock has been reduced to sandy fragments
by heat, or by obscure chemical and other molecular forces, the sand-beds
may remain undisturbed, and represent, in the series of geological strata, the
solid formations from which they were derived. The large masses of sand
not found in place have been transported and accumulated by water or by
wind, the former being generally considered the most important of these
agencies; for the extensive deposits of the Sahara, of the Arabian
peninsulas, of the Llano Estacado and other North and South American
deserts, of the deserts of Persia, and of that of Gobi, are supposed to have
been swept together or distributed by marine currents, and to have been
elevated above the ocean by the same means as other upheaved strata.
Meteoric and mechanical influences are still active in the reduction of rocks
to a fragmentary state; [Footnote: A good account of the agencies now
operative in the reduction of rock to sand will be found in Winkler, Zand en
Duinen, Dockarm, 1865, pp. 4-20. I take this occasion to acknowledge my
obligations to this author for assuming the responsibility of many of the
errors I may have committed in this chapter, by translating a large part of it
from a former edition of the present work and publishing it as his own.] but
the quantity of sand now transported to the sea seems to be comparatively
inconsiderable, because—not to speak of the absence of diluvial action—
the number of torrents emptying directly into the sea is much less than it
was at earlier periods. The formation of alluvial plains in maritime bays, by
the sedimentary matter brought down from the mountains, has lengthened
the flow of such streams and converted them very generally into rivers, or
rather affluents of rivers of later geographical origin than themselves. The
filling up of the estuaries has so reduced the slope of all large and many
small rivers, and, consequently, so checked the current of what the Germans
call their Unterlauf, or lower course, that they are much less able to
transport heavy material than at earlier epochs. The slime deposited by
Page 677
rivers at their junction with the sea, is usually found to be composed of
material too finely ground and too light to be denominated sand, and it can
be abundantly shown that the sand-banks at the outlet of most large streams
are of tidal, not of fluviatile, accumulation, or, in lakes and tideless seas, a
result of the concurrent action of waves and of wind. Large deposits of
sand, therefore, must in general be considered as of ancient, not of recent
formation, and many eminent geologists ascribe them to diluvial action.
Staring has discussed this question very fully, with special reference to the
sands of the North Sea, the Zuiderzee, and the bays and channels of the
Dutch coast. [Footnote: De Bodem van Nederland, i., pp. 243, 246-377, et
seqq. See also the arguments of Bremontier as to the origin of the dune-
sands of Gascony, Annales des Ponts et Chaussees, 1833, 1er semestre, pp.
158, 161. Bremontier estimates the sand anually thrown up on that coast at
five cubic toises and two feet to the running toise (ubi supra, p. 162), or
rather more than two hundred and twenty cubic feet to the running foot.
Laval, upon observations continued through seven years, found the quantity
to be twenty-five metres per running metre, which is equal to two hundred
and sixty-eight cubic feet to the running foot.—Annales des Ponts et
Chaussees, 1842, 2me semestre, p. 229. These computations make the
proportion of sand deposited on the coast of Gascony three or four times as
great as that observed by Andresen on the shores of Jutland. Laval estimates
the total quantity of sand annually thrown up on the coast of Gascony at
6,000,000 cubic metres, or more than 7,800,000 cubic yards.] His general
conclusion is, that the rivers of the Netherlands "move sand only by a very
slow displacement of sand-banks, and do not carry it with them as a
suspended or floating material." The sands of the German Ocean he holds to
be a product of the "great North German drift," deposited where they now
lie before the commencement of the present geological period, and he
maintains similar opinions with regard to the sands thrown up by the
material too finely ground and too light to be denominated sand, and it can
be abundantly shown that the sand-banks at the outlet of most large streams
are of tidal, not of fluviatile, accumulation, or, in lakes and tideless seas, a
result of the concurrent action of waves and of wind. Large deposits of
sand, therefore, must in general be considered as of ancient, not of recent
formation, and many eminent geologists ascribe them to diluvial action.
Staring has discussed this question very fully, with special reference to the
sands of the North Sea, the Zuiderzee, and the bays and channels of the
Dutch coast. [Footnote: De Bodem van Nederland, i., pp. 243, 246-377, et
seqq. See also the arguments of Bremontier as to the origin of the dune-
sands of Gascony, Annales des Ponts et Chaussees, 1833, 1er semestre, pp.
158, 161. Bremontier estimates the sand anually thrown up on that coast at
five cubic toises and two feet to the running toise (ubi supra, p. 162), or
rather more than two hundred and twenty cubic feet to the running foot.
Laval, upon observations continued through seven years, found the quantity
to be twenty-five metres per running metre, which is equal to two hundred
and sixty-eight cubic feet to the running foot.—Annales des Ponts et
Chaussees, 1842, 2me semestre, p. 229. These computations make the
proportion of sand deposited on the coast of Gascony three or four times as
great as that observed by Andresen on the shores of Jutland. Laval estimates
the total quantity of sand annually thrown up on the coast of Gascony at
6,000,000 cubic metres, or more than 7,800,000 cubic yards.] His general
conclusion is, that the rivers of the Netherlands "move sand only by a very
slow displacement of sand-banks, and do not carry it with them as a
suspended or floating material." The sands of the German Ocean he holds to
be a product of the "great North German drift," deposited where they now
lie before the commencement of the present geological period, and he
maintains similar opinions with regard to the sands thrown up by the
Page 678
Mediterranean at the mouths of the Nile and on the Barbary coast.
[Footnote: De Bodem van Nederland, i., p. 339.]
Sand now carried to the Sea.
There are, however, cases where mountain streams still bear to the sea
perhaps relatively small, but certainly absolutely large, amounts of
disintegrated rock. [Footnote: The conditions favorable to the production of
sand from disintegrated rock, by causes now in action, are perhaps nowhere
more perfectly realized than in the Sinaitic Peninsula. The mountains are
steep and lofty, unprotected by vegetation or even by a coating of earth, and
the rocks which compose them are in a shattered and fragmentary
condition. They are furrowed by deep and precipitous ravines, with beds
sufficiently inclined for the rapid flow of water, and generally without
basins in which the larger blocks of stone rolled by the torrents can be
dropped and left in repose; there are severe frosts and much snow on the
higher summits and ridges, and the winter rains are abundant and heavy.
The mountains are principally of igneous formation, but many of the less
elevated peaks are capped with sandstone, and on the eastern slope of the
peninsula you may sometimes see, at a single glance, several lofty pyramids
of granite, separated by considerable intervals, and all surmounted by
horizontally stratified deposits of sandstone often only a few yards square,
which correspond to each other in height, are evidently contemporaneous in
origin, and were once connected in continuous beds. The degradation of the
rock on which this formation rests is constantly bringing down masses of it,
and mingling them with the basaltic, porphyritic, granitic, and calcareous
fragments which the torrents carry down to the valleys, and, through them,
in a state of greater or less disintegration, to the sea. The quantity of sand
annually washed into the Red Sea by the larger torrents of the Lesser
Peninsula, is probably at least equal to that contributed to the ocean by any
[Footnote: De Bodem van Nederland, i., p. 339.]
Sand now carried to the Sea.
There are, however, cases where mountain streams still bear to the sea
perhaps relatively small, but certainly absolutely large, amounts of
disintegrated rock. [Footnote: The conditions favorable to the production of
sand from disintegrated rock, by causes now in action, are perhaps nowhere
more perfectly realized than in the Sinaitic Peninsula. The mountains are
steep and lofty, unprotected by vegetation or even by a coating of earth, and
the rocks which compose them are in a shattered and fragmentary
condition. They are furrowed by deep and precipitous ravines, with beds
sufficiently inclined for the rapid flow of water, and generally without
basins in which the larger blocks of stone rolled by the torrents can be
dropped and left in repose; there are severe frosts and much snow on the
higher summits and ridges, and the winter rains are abundant and heavy.
The mountains are principally of igneous formation, but many of the less
elevated peaks are capped with sandstone, and on the eastern slope of the
peninsula you may sometimes see, at a single glance, several lofty pyramids
of granite, separated by considerable intervals, and all surmounted by
horizontally stratified deposits of sandstone often only a few yards square,
which correspond to each other in height, are evidently contemporaneous in
origin, and were once connected in continuous beds. The degradation of the
rock on which this formation rests is constantly bringing down masses of it,
and mingling them with the basaltic, porphyritic, granitic, and calcareous
fragments which the torrents carry down to the valleys, and, through them,
in a state of greater or less disintegration, to the sea. The quantity of sand
annually washed into the Red Sea by the larger torrents of the Lesser
Peninsula, is probably at least equal to that contributed to the ocean by any
Page 679
streams draining basins of no greater extent. Absolutely considered, then,
the mass may be said to be large, but it is apparently very small as
compared with the sand thrown up by the German Ocean and the Atlantic
on the coasts of Denmark and of France. There are, indeed, in Arabia
Petraea, many torrents with very short courses, for the sea-waves in many
parts of the peninsular coast wash the base of the mountains. In these cases,
the debris of the rocks do not reach the sea in a sufficiently comminuted
condition to be entitled to the appellation of sand, or even in the form of
well-rounded pebbles. The fragments retain their annular shape, and, at
some points on the coast, they become cemented together by lime or other
binding substances held in solution or mechanical suspension in the sea-
water, and are so rapidly converted into a singularly heterogeneous
conglomerate, that one deposit seems to be consolidated into a breccia
before the next winter's torrents cover it with another.
In the northern part of the peninsula there are extensive deposits of sand
intermingled with agate pebbles and petrified wood, but these are evidently
neither derived from the Sinaitic group, nor products of local causes known
to be now in action.
I may here notice the often repeated but mistaken assertion, that the
petrified wood of the Western Arabian desert consists wholly of the stems
of palms, or at least of endogenous vegetables. This is an error. I have
myself picked up in that desert, within the space of a very few square yards,
fragments apparently of fossil palms, and of at least two petrified trees
distinctly marked as of exogenous growth both by annular structure and by
knots. In ligneous character, one of these almost precisely resembles the
grain of the extant beech, and this specimen was worm-eaten before it was
converted into silex.]
the mass may be said to be large, but it is apparently very small as
compared with the sand thrown up by the German Ocean and the Atlantic
on the coasts of Denmark and of France. There are, indeed, in Arabia
Petraea, many torrents with very short courses, for the sea-waves in many
parts of the peninsular coast wash the base of the mountains. In these cases,
the debris of the rocks do not reach the sea in a sufficiently comminuted
condition to be entitled to the appellation of sand, or even in the form of
well-rounded pebbles. The fragments retain their annular shape, and, at
some points on the coast, they become cemented together by lime or other
binding substances held in solution or mechanical suspension in the sea-
water, and are so rapidly converted into a singularly heterogeneous
conglomerate, that one deposit seems to be consolidated into a breccia
before the next winter's torrents cover it with another.
In the northern part of the peninsula there are extensive deposits of sand
intermingled with agate pebbles and petrified wood, but these are evidently
neither derived from the Sinaitic group, nor products of local causes known
to be now in action.
I may here notice the often repeated but mistaken assertion, that the
petrified wood of the Western Arabian desert consists wholly of the stems
of palms, or at least of endogenous vegetables. This is an error. I have
myself picked up in that desert, within the space of a very few square yards,
fragments apparently of fossil palms, and of at least two petrified trees
distinctly marked as of exogenous growth both by annular structure and by
knots. In ligneous character, one of these almost precisely resembles the
grain of the extant beech, and this specimen was worm-eaten before it was
converted into silex.]
Page 680
The quantity of sand and gravel carried into the Mediterranean by the
torrents of the Maritime Alps, the Ligurian Apennines, the islands of
Corsica, Sardinia, and Sicily, and the mountains of Calabria, is apparently
great. In mere mass, it is possible, if not probable, that as much rocky
material, more or less comminuted, is contributed to the basin of the
Mediterranean by Europe, even excluding the shores of the Adriatic and the
Euxine, as is washed up from it upon the coasts of Northern Africa and
Syria. A great part of this material is thrown out again by the waves on the
European shores of that sea. The harbors of Luni, Albenga, San Remo, and
Savona west of Genoa, and of Porto Fino on the other side, are filling up,
and the coast near Carrara and Massa is said to have advanced upon the sea
to a distance of 475 feet in thirty-three years. [Footnote: Bottger, Das
Mittelmeer, p. 128.] Besides this, we have no evidence of the existence of
deep-water currents in the Mediterranean, extensive enough and strong
enough to transport quartzose sand across the sea. It may be added that
much of the rock from which the torrent sands of Southern Europe are
derived contains little quartz, and hence the general character of these sands
is such that they must be decomposed or ground down to an impalpable
slime, long before they could be swept over to the African shore.
Sands of Northern Africa.
The torrents of Europe, then, do not at present furnish the material which
composes the beach sands of Northern Africa, and it is equally certain that
those sands are not brought down by the rivers of the latter continent. They
belong to a remote geological period, and have been accumulated by causes
which we cannot at present assign. The wind does not stir water to great
depths with sufficient force to disturb the bottom, [Footnote: The testimony
of divers and of other observers on this point is conflicting, as might be
expected from the infinite variety of conditions by which the movement of
torrents of the Maritime Alps, the Ligurian Apennines, the islands of
Corsica, Sardinia, and Sicily, and the mountains of Calabria, is apparently
great. In mere mass, it is possible, if not probable, that as much rocky
material, more or less comminuted, is contributed to the basin of the
Mediterranean by Europe, even excluding the shores of the Adriatic and the
Euxine, as is washed up from it upon the coasts of Northern Africa and
Syria. A great part of this material is thrown out again by the waves on the
European shores of that sea. The harbors of Luni, Albenga, San Remo, and
Savona west of Genoa, and of Porto Fino on the other side, are filling up,
and the coast near Carrara and Massa is said to have advanced upon the sea
to a distance of 475 feet in thirty-three years. [Footnote: Bottger, Das
Mittelmeer, p. 128.] Besides this, we have no evidence of the existence of
deep-water currents in the Mediterranean, extensive enough and strong
enough to transport quartzose sand across the sea. It may be added that
much of the rock from which the torrent sands of Southern Europe are
derived contains little quartz, and hence the general character of these sands
is such that they must be decomposed or ground down to an impalpable
slime, long before they could be swept over to the African shore.
Sands of Northern Africa.
The torrents of Europe, then, do not at present furnish the material which
composes the beach sands of Northern Africa, and it is equally certain that
those sands are not brought down by the rivers of the latter continent. They
belong to a remote geological period, and have been accumulated by causes
which we cannot at present assign. The wind does not stir water to great
depths with sufficient force to disturb the bottom, [Footnote: The testimony
of divers and of other observers on this point is conflicting, as might be
expected from the infinite variety of conditions by which the movement of
Page 681
water is affected. It is generally believed that the action of the wind upon
the water is not perceptible at greater depths than from fifteen feet in
ordinary to eighty or ninety in extreme cases; but these estimates are
probably very considerably below the truth. Andresen quotes Bremontier as
stating that the movement of the waves sometimes extends to the depth of
five hundred feet, and he adds that others think it may reach to six or even
seven hundred feet below the surface.—Andresen, Om Klitformationen, p.
20.
Many physicists now suppose that the undulations of great bodies of
water reach even deeper. But a movement of undulation is not necessarily a
movement of translation, and besides, there is very frequently an undertow,
which tends to carry suspended bodies out to sea as powerfully as the
superficial waves to throw them on shore. Sand-banks sometimes recede
from the coast, instead of rolling towards it. Reclus informs us that the
Mauvaise, a sand-bank near the Point de Grave, on the Atlantic coast of
France, has moved five miles to the west in less than a century.—Revue des
Deux Mondes for December, 1862, p. 905.
The action of currents may, in some cases, have been confounded with
that of the waves. Sea-currents, strong enough, possibly, to transport sand
for some distance, flow far below the surface in parts of the open ocean,
and in narrow straits they have great force and velocity. The divers
employed at Constantinople in 1853 found in the Bosphorus, at the depth of
twenty-five fathoms and at a point much exposed to the wash from Galata
and Pera, a number of bronze guns supposed to have belonged to a ship-of-
war blown up about a hundred and fifty years before. These guns were not
covered by sand or slime, though a crust of earthy matter, an inch in
thickness, adhered to their upper surfaces, and the bottom of the strait
appeared to be wholly free from sediment. The current was so powerful at
this depth that the divers were hardly able to stand, and a keg of nails,
the water is not perceptible at greater depths than from fifteen feet in
ordinary to eighty or ninety in extreme cases; but these estimates are
probably very considerably below the truth. Andresen quotes Bremontier as
stating that the movement of the waves sometimes extends to the depth of
five hundred feet, and he adds that others think it may reach to six or even
seven hundred feet below the surface.—Andresen, Om Klitformationen, p.
20.
Many physicists now suppose that the undulations of great bodies of
water reach even deeper. But a movement of undulation is not necessarily a
movement of translation, and besides, there is very frequently an undertow,
which tends to carry suspended bodies out to sea as powerfully as the
superficial waves to throw them on shore. Sand-banks sometimes recede
from the coast, instead of rolling towards it. Reclus informs us that the
Mauvaise, a sand-bank near the Point de Grave, on the Atlantic coast of
France, has moved five miles to the west in less than a century.—Revue des
Deux Mondes for December, 1862, p. 905.
The action of currents may, in some cases, have been confounded with
that of the waves. Sea-currents, strong enough, possibly, to transport sand
for some distance, flow far below the surface in parts of the open ocean,
and in narrow straits they have great force and velocity. The divers
employed at Constantinople in 1853 found in the Bosphorus, at the depth of
twenty-five fathoms and at a point much exposed to the wash from Galata
and Pera, a number of bronze guns supposed to have belonged to a ship-of-
war blown up about a hundred and fifty years before. These guns were not
covered by sand or slime, though a crust of earthy matter, an inch in
thickness, adhered to their upper surfaces, and the bottom of the strait
appeared to be wholly free from sediment. The current was so powerful at
this depth that the divers were hardly able to stand, and a keg of nails,
Page 682
purposely dropped into the water, in order that its movements might serve
as a guide in the search for a bag of coin accidentally lost overboard from a
ship in the harbor, was rolled by the stream several hundred yards before it
stopped.] and the sand thrown upon the coast in question must be derived
from a narrow belt of sea. It must hence, in time, become exhausted, and
the formation of new sand-banks and dunes upon the southern shores of the
Mediterranean will cease at last for want of material. [Footnote: Few seas
have thrown up so much sand as the shallow German Ocean; but there is
some reason to think that the amount of this material now cast upon its
northern shores is less than at some former periods, though no extensive
series of observations on this subject has been recorded. On the Spit of
Agger, at the present outlet of the Liimfjord, Andresen found the quantity
during ten years, on a beach about five hundred and seventy feet broad,
equal to an annual deposit of an inch and a half over the whole surface.—
Om Klitformationen, p. 56. This gives seventy-one and a quarter cubic feet
to the running foot—a quantity certainly much smaller than that cast up by
the same sea on the shores of the Dano-German duchies and of Holland,
and, as we have seen, scarcely one-fourth of that deposited by the Atlantic
on the coast of Gascony.]
But even in the cases where the accumulations of sand in extensive
deserts appear to be of marine formation, or rather aggregation, and to have
been brought to their present position by upheaval, they are not wholly
composed of material collected or distributed by the currents of the sea; for,
in all such regions, they continue to receive some small contributions from
the disintegration of the rocks which underlie, or crop out through, the
superficial deposits. [Footnote: See, on this subject, an article in Aus der
Natur, vol. xxx., p. 590.
The Florentine Frescobaldi, who visited the Sinaitic peninsula five
hundred years ago, observed the powerful action of the solar heat in the
as a guide in the search for a bag of coin accidentally lost overboard from a
ship in the harbor, was rolled by the stream several hundred yards before it
stopped.] and the sand thrown upon the coast in question must be derived
from a narrow belt of sea. It must hence, in time, become exhausted, and
the formation of new sand-banks and dunes upon the southern shores of the
Mediterranean will cease at last for want of material. [Footnote: Few seas
have thrown up so much sand as the shallow German Ocean; but there is
some reason to think that the amount of this material now cast upon its
northern shores is less than at some former periods, though no extensive
series of observations on this subject has been recorded. On the Spit of
Agger, at the present outlet of the Liimfjord, Andresen found the quantity
during ten years, on a beach about five hundred and seventy feet broad,
equal to an annual deposit of an inch and a half over the whole surface.—
Om Klitformationen, p. 56. This gives seventy-one and a quarter cubic feet
to the running foot—a quantity certainly much smaller than that cast up by
the same sea on the shores of the Dano-German duchies and of Holland,
and, as we have seen, scarcely one-fourth of that deposited by the Atlantic
on the coast of Gascony.]
But even in the cases where the accumulations of sand in extensive
deserts appear to be of marine formation, or rather aggregation, and to have
been brought to their present position by upheaval, they are not wholly
composed of material collected or distributed by the currents of the sea; for,
in all such regions, they continue to receive some small contributions from
the disintegration of the rocks which underlie, or crop out through, the
superficial deposits. [Footnote: See, on this subject, an article in Aus der
Natur, vol. xxx., p. 590.
The Florentine Frescobaldi, who visited the Sinaitic peninsula five
hundred years ago, observed the powerful action of the solar heat in the
Page 683
disintegration of the desert rocks. "This place," says he, "was a ridge of
rocks burnt to powder by the sun, and this powder is blown away from the
rock by the wind and is the sand of the desert; and there be many hills
which are pure bare rock, and when the sun parcheth them, the wind carries
off the dust, and other sand is there none in that land,"—Viaggio, pp. 69,
70. In Arabia Petraea, when a wind, powerful enough to scour down below
the ordinary surface of the desert and lay bare a fresh bed of stones, is
followed by a sudden burst of sunshine, the dark agate pebbles are often
cracked and broken by the heat; and this is the true explanation of the
occurrence of the fragments in situations where the action of fire is not
probable. If the fragments are small enough to be rolled by the winds, they
are in time ground down to sand and contribute to the stock of that material
which covers the face of the desert, though the sand thus formed is but an
infinitesimal proportion of the whole.] In some instances, too, as in
Northern Africa, additions are constantly made to the mass by the
prevalence of sea-winds, which transport, or, to speak more precisely, roll
the finer beach-sand to considerable distances into the interior. But this is a
very slow process, and the exaggerations of travellers have diffused a vast
deal of popular error on the subject.
Sands of Egypt.
In the narrow valley of the Nile—which, above its bifurcation near Cairo,
is, throughout Egypt and Nubia, generally bounded by precipitous cliffs—
wherever a ravine or other considerable depression occurs in the wall of
rock, one sees what seems a stream of desert sand pouring down, and
common observers have hence concluded that the whole valley is in danger
of being buried under a stratum of infertile soil. The ancient Egyptians
apprehended this, and erected walls, often of unburnt brick, across the
outlet of gorges and lateral valleys, to check the flow of the sand-streams.
rocks burnt to powder by the sun, and this powder is blown away from the
rock by the wind and is the sand of the desert; and there be many hills
which are pure bare rock, and when the sun parcheth them, the wind carries
off the dust, and other sand is there none in that land,"—Viaggio, pp. 69,
70. In Arabia Petraea, when a wind, powerful enough to scour down below
the ordinary surface of the desert and lay bare a fresh bed of stones, is
followed by a sudden burst of sunshine, the dark agate pebbles are often
cracked and broken by the heat; and this is the true explanation of the
occurrence of the fragments in situations where the action of fire is not
probable. If the fragments are small enough to be rolled by the winds, they
are in time ground down to sand and contribute to the stock of that material
which covers the face of the desert, though the sand thus formed is but an
infinitesimal proportion of the whole.] In some instances, too, as in
Northern Africa, additions are constantly made to the mass by the
prevalence of sea-winds, which transport, or, to speak more precisely, roll
the finer beach-sand to considerable distances into the interior. But this is a
very slow process, and the exaggerations of travellers have diffused a vast
deal of popular error on the subject.
Sands of Egypt.
In the narrow valley of the Nile—which, above its bifurcation near Cairo,
is, throughout Egypt and Nubia, generally bounded by precipitous cliffs—
wherever a ravine or other considerable depression occurs in the wall of
rock, one sees what seems a stream of desert sand pouring down, and
common observers have hence concluded that the whole valley is in danger
of being buried under a stratum of infertile soil. The ancient Egyptians
apprehended this, and erected walls, often of unburnt brick, across the
outlet of gorges and lateral valleys, to check the flow of the sand-streams.
Page 684
In later ages, these walls have mostly fallen into decay, and no preventive
measures against such encroachments are now resorted to. But the extent of
the mischief to the soil of Egypt, and the future danger from this source,
have been much overrated. The sand on the borders of the Nile is neither
elevated so high by the wind, nor transported by that agency in so great
masses, as is popularly supposed; and of that which is actually lifted or
rolled and finally deposited by air-currents, a considerable proportion is
either calcareous, and, therefore, readily decomposable, or in the state of a
very fine dust, and so, in neither case, injurious to the soil. There are,
indeed, both in Africa and in Arabia, considerable tracts of fine, silicious
sand, which may be carried far by high winds, but these are exceptional
cases, and in general the progress of the desert sand is by a rolling motion
along the surface. [Footnote: Sand heaps, three and even six hundred feet
high, are indeed formed by the wind, but this is effected by driving the
particles up an inclined plane, not by lifting them. Bremontier, speaking of
the sand-hills on the western coast of France, says: "The particles of sand
composing them are not large enough to resist wind of a certain force, nor
small enough to be taken up by it, like dust; they only roll along the surface
from which they are detached, and, though moving with great velocity, they
rarely rise to a greater height than three or four inches."—Memoirs sur les
Dunes, Annales des Ponts et Chaussecs, 1833, ler semestre, p, 148.
Andresen says that a wind, having a velocity of forty feet per second, is
strong enough to raise particles of sand as high as the face and eyes of a
man, but that, in general, it rolls along the ground, and is scarcely ever
thrown more than to the height of a couple of yards from the surface. Even
in these cases, it is carried forward by a hopping, not a continuous, motion;
for a very narrow sheet or channel of water stops the drift entirely, all the
sand dropping into it until it is filled up.
measures against such encroachments are now resorted to. But the extent of
the mischief to the soil of Egypt, and the future danger from this source,
have been much overrated. The sand on the borders of the Nile is neither
elevated so high by the wind, nor transported by that agency in so great
masses, as is popularly supposed; and of that which is actually lifted or
rolled and finally deposited by air-currents, a considerable proportion is
either calcareous, and, therefore, readily decomposable, or in the state of a
very fine dust, and so, in neither case, injurious to the soil. There are,
indeed, both in Africa and in Arabia, considerable tracts of fine, silicious
sand, which may be carried far by high winds, but these are exceptional
cases, and in general the progress of the desert sand is by a rolling motion
along the surface. [Footnote: Sand heaps, three and even six hundred feet
high, are indeed formed by the wind, but this is effected by driving the
particles up an inclined plane, not by lifting them. Bremontier, speaking of
the sand-hills on the western coast of France, says: "The particles of sand
composing them are not large enough to resist wind of a certain force, nor
small enough to be taken up by it, like dust; they only roll along the surface
from which they are detached, and, though moving with great velocity, they
rarely rise to a greater height than three or four inches."—Memoirs sur les
Dunes, Annales des Ponts et Chaussecs, 1833, ler semestre, p, 148.
Andresen says that a wind, having a velocity of forty feet per second, is
strong enough to raise particles of sand as high as the face and eyes of a
man, but that, in general, it rolls along the ground, and is scarcely ever
thrown more than to the height of a couple of yards from the surface. Even
in these cases, it is carried forward by a hopping, not a continuous, motion;
for a very narrow sheet or channel of water stops the drift entirely, all the
sand dropping into it until it is filled up.
Page 685
Blake observes, Pacific Railroad Report, vol. v., p. 242, that the sand of
the Colorado desert does not rise high in the air, but bounds along on the
surface or only a few inches above it.
The character of the motion of sand drifts is well illustrated by an
interesting fact not much noticed hitherto by travellers in the East. In
situations where the sand is driven through depressions in rock-beds, or
over deposits of silicious pebbles, the surface of the stone is worn and
smoothed much more effectually than it could be by running water, and I
have picked up, in such localities, rounded, irregularly broken fragments of
agate, which had received from the attrition of the sand as fine a polish as
could be given them by the wheel of the lapidary.
Very interesting observations, by Blake, on the polishing of hard stones
by drifting sand will be found in the Pacific Railroad Report, vol. v., pp. 92,
230, 231. The grinding and polishing power of sand has lately received a
new and most ingenious application in America. Jets of sand, and even of
small particles of softer substances, thrown with a certain force, are found
capable of cutting the hardest minerals and metals. A block of corundum,
some inches thick, has been bored through in a few minutes by this process,
and it promises to be highly useful in glass-cutting and other similar
operations.] So little is it lifted, and so inconsiderable is the quantity yet
remaining on the borders of Egypt, that a wall four or five feet high suffices
for centuries to check its encroachments. This is obvious to the eye of every
observer who prefers the true to the marvellous; but the old-world fable of
the overwhelming of caravans by the fearful simoom—which even the
Arabs no longer repeat, if indeed they are the authors of it—is so
thoroughly rooted in the imagination of Christendom that most desert
travellers, of the tourist class, think they shall disappoint the readers of their
journals if they do not recount the particulars of their escape from being
buried alive by a sand-storm, and the popular demand for a "sensation"
the Colorado desert does not rise high in the air, but bounds along on the
surface or only a few inches above it.
The character of the motion of sand drifts is well illustrated by an
interesting fact not much noticed hitherto by travellers in the East. In
situations where the sand is driven through depressions in rock-beds, or
over deposits of silicious pebbles, the surface of the stone is worn and
smoothed much more effectually than it could be by running water, and I
have picked up, in such localities, rounded, irregularly broken fragments of
agate, which had received from the attrition of the sand as fine a polish as
could be given them by the wheel of the lapidary.
Very interesting observations, by Blake, on the polishing of hard stones
by drifting sand will be found in the Pacific Railroad Report, vol. v., pp. 92,
230, 231. The grinding and polishing power of sand has lately received a
new and most ingenious application in America. Jets of sand, and even of
small particles of softer substances, thrown with a certain force, are found
capable of cutting the hardest minerals and metals. A block of corundum,
some inches thick, has been bored through in a few minutes by this process,
and it promises to be highly useful in glass-cutting and other similar
operations.] So little is it lifted, and so inconsiderable is the quantity yet
remaining on the borders of Egypt, that a wall four or five feet high suffices
for centuries to check its encroachments. This is obvious to the eye of every
observer who prefers the true to the marvellous; but the old-world fable of
the overwhelming of caravans by the fearful simoom—which even the
Arabs no longer repeat, if indeed they are the authors of it—is so
thoroughly rooted in the imagination of Christendom that most desert
travellers, of the tourist class, think they shall disappoint the readers of their
journals if they do not recount the particulars of their escape from being
buried alive by a sand-storm, and the popular demand for a "sensation"
Page 686
must be gratified accordingly. [Footnote: Wilkinson says that, in much
experience in the most sandy parts of the Libyan desert, and much inquiry
of the best native sources, he never saw or heard of any instance of danger
to man or beast from the mere accumulation of sand transported by the
wind. Chesney's observations in Arabia, and the testimony of the Bedouins
he consulted, are to the same purpose. The dangers of the simoom are of a
different character, though they are certainly aggravated by the blinding
effects of the light particles of dust and sand borne along by it, and by that
of the inhalation of them upon the respiration. ]
Another circumstance is necessary to be considered in estimating the
danger to which the arable lands of Egypt are exposed. The prevailing wind
in the valley of the Nile and its borders is from the north, and it may be said
without exaggeration that the north wind blows for three-quarters of the
year. [Footnote: In the narrow valley of the Nile, bounded as it is, above the
Delta, by high cliffs, all air-currents from the northern quarter become north
winds, though of course varying in partial direction, in conformity with the
sinuosities of the valley. Upon the desert plateau they incline westwards,
and have already borne into the valley the sands of the eastern banks, and
driven those of the western quite out of the Egyptian portion of the Nile
basin.] The effect of winds blowing up the valley is to drive the sands of the
desert plateau which border it, in a direction parallel with the axis of the
valley, not transversely to it; and if it ran in a straight line, the north wind
would carry no desert sand into it. There are, however, both curves and
angles in its course, and hence, wherever its direction deviates from that of
the wind, it might receive sand-drifts from the desert plain through which it
runs. But, in the course of ages, the winds have, in a great measure, bared
the projecting points of their ancient deposits, and no great accumulations
remain in situations from which either a north or a south wind would carry
them into the valley. [Footnote: These considerations apply, with equal
force, to the supposed danger of the obstruction of the Suez Canal by the
experience in the most sandy parts of the Libyan desert, and much inquiry
of the best native sources, he never saw or heard of any instance of danger
to man or beast from the mere accumulation of sand transported by the
wind. Chesney's observations in Arabia, and the testimony of the Bedouins
he consulted, are to the same purpose. The dangers of the simoom are of a
different character, though they are certainly aggravated by the blinding
effects of the light particles of dust and sand borne along by it, and by that
of the inhalation of them upon the respiration. ]
Another circumstance is necessary to be considered in estimating the
danger to which the arable lands of Egypt are exposed. The prevailing wind
in the valley of the Nile and its borders is from the north, and it may be said
without exaggeration that the north wind blows for three-quarters of the
year. [Footnote: In the narrow valley of the Nile, bounded as it is, above the
Delta, by high cliffs, all air-currents from the northern quarter become north
winds, though of course varying in partial direction, in conformity with the
sinuosities of the valley. Upon the desert plateau they incline westwards,
and have already borne into the valley the sands of the eastern banks, and
driven those of the western quite out of the Egyptian portion of the Nile
basin.] The effect of winds blowing up the valley is to drive the sands of the
desert plateau which border it, in a direction parallel with the axis of the
valley, not transversely to it; and if it ran in a straight line, the north wind
would carry no desert sand into it. There are, however, both curves and
angles in its course, and hence, wherever its direction deviates from that of
the wind, it might receive sand-drifts from the desert plain through which it
runs. But, in the course of ages, the winds have, in a great measure, bared
the projecting points of their ancient deposits, and no great accumulations
remain in situations from which either a north or a south wind would carry
them into the valley. [Footnote: These considerations apply, with equal
force, to the supposed danger of the obstruction of the Suez Canal by the
Page 687
drifting of the desert sands. The winds across the isthmus are almost
uniformly from the north, and they swept it comparatively clean of flying
sands long ages since. The traces of the ancient canal between the Red Sea
and the Nile are easily followed for a considerable distance from Suez. Had
the drifts upon the isthmus been as formidable as some have feared and
others have hoped, those traces would have been obliterated, and Lake
Timsah and the Bitter Lakes filled up, many centuries ago. The few
particles driven by the rare east and west winds towards the line of the
canal, will easily be arrested by plantations or other simple methods, or
removed by dredging. The real dangers and difficulties of this magnificent
enterprise—and they have been great—consisted in the nature of the soil to
be removed in order to form the line, and especially in the constantly
increasing accumulation of sea-sand at the southern terminus by the tides of
the Red Sea, and of sand and Nile slime at the northern, by the action of the
winds and currents. Both seas are shallow for miles from the shore, and the
excavation and maintenance of deep channels, and of capacious harbors
with easy and secure entrances, in such localities, is doubtless one of the
hardest problems offered to modern engineers for practical solution. See
post, Geological Importance of Dunes, note.]
The sand let fall in Egypt by the north wind is derived, not from the
desert, but from a very different source—the sea. Considerable quantities of
sand are thrown up by the Mediterranean, at and between the mouths of the
Nile, and indeed along almost the whole southern coast of that sea, and
drifted into the interior to distances varying according to the force of the
wind and the abundance and quality of the material. The sand so transported
contributes to the gradual elevation of the Delta, and of the banks and bed
of the river itself. But just in proportion as the bed of the stream is elevated,
the height of the water in the annual inundations is increased also, and as
the inclination of the channel is diminished, the rapidity of the current is
checked, and the deposition of the slime it holds in suspension consequently
uniformly from the north, and they swept it comparatively clean of flying
sands long ages since. The traces of the ancient canal between the Red Sea
and the Nile are easily followed for a considerable distance from Suez. Had
the drifts upon the isthmus been as formidable as some have feared and
others have hoped, those traces would have been obliterated, and Lake
Timsah and the Bitter Lakes filled up, many centuries ago. The few
particles driven by the rare east and west winds towards the line of the
canal, will easily be arrested by plantations or other simple methods, or
removed by dredging. The real dangers and difficulties of this magnificent
enterprise—and they have been great—consisted in the nature of the soil to
be removed in order to form the line, and especially in the constantly
increasing accumulation of sea-sand at the southern terminus by the tides of
the Red Sea, and of sand and Nile slime at the northern, by the action of the
winds and currents. Both seas are shallow for miles from the shore, and the
excavation and maintenance of deep channels, and of capacious harbors
with easy and secure entrances, in such localities, is doubtless one of the
hardest problems offered to modern engineers for practical solution. See
post, Geological Importance of Dunes, note.]
The sand let fall in Egypt by the north wind is derived, not from the
desert, but from a very different source—the sea. Considerable quantities of
sand are thrown up by the Mediterranean, at and between the mouths of the
Nile, and indeed along almost the whole southern coast of that sea, and
drifted into the interior to distances varying according to the force of the
wind and the abundance and quality of the material. The sand so transported
contributes to the gradual elevation of the Delta, and of the banks and bed
of the river itself. But just in proportion as the bed of the stream is elevated,
the height of the water in the annual inundations is increased also, and as
the inclination of the channel is diminished, the rapidity of the current is
checked, and the deposition of the slime it holds in suspension consequently
Page 688
promoted. Thus the winds and the water, moving in contrary directions, join
in producing a common effect.
The sand, blown over the Delta and the cultivated land higher up the
stream during the inundation, is covered or mixed with the fertile earth
brought down by the river, and no serious injury is sustained from it. That
spread over the same ground after the water has subsided, and during the
short period when the soil is not stirred by cultivation or covered by the
flood, forms a thin pellicle over the surface as far as it extends, and serves
to divide and distinguish the successive layers of slime deposited by the
annual inundations. The particles taken up by the wind on the sea-beach are
borne onward, by a hopping motion, or rolled along the surface, until they
are arrested by the temporary cessation of the wind, by vegetation, or by
some other obstruction, and they may, in process of time, accumulate in
large masses, under the lee of rocky projections, buildings, or other barriers
which break the force of the wind.
In these facts we find an important element in the explanation of the sand
drifts, which have half buried the Sphinx and so many other ancient
monuments in that part of Egypt. These drifts, as I have said, are not wholly
from the desert, but in largo proportion from the sea; and, as might be
supposed from the distance they have travelled, they have been long in
gathering. While Egypt was a great and flourishing kingdom, measures
were taken to protect its territory against the encroachment of sand, whether
from the desert or from the Mediterranean; but the foreign conquerors, who
destroyed so many of its religious monuments, did not spare its public
works, and the process of physical degradation undoubtedly began as early
as the Persian invasion. The urgent necessity, which has compelled all the
successive tyrannies of Egypt to keep up some of the canals and other
arrangements for irrigation, was not felt with respect to the advancement of
the sands; for their progress was so slow as hardly to be perceptible in the
in producing a common effect.
The sand, blown over the Delta and the cultivated land higher up the
stream during the inundation, is covered or mixed with the fertile earth
brought down by the river, and no serious injury is sustained from it. That
spread over the same ground after the water has subsided, and during the
short period when the soil is not stirred by cultivation or covered by the
flood, forms a thin pellicle over the surface as far as it extends, and serves
to divide and distinguish the successive layers of slime deposited by the
annual inundations. The particles taken up by the wind on the sea-beach are
borne onward, by a hopping motion, or rolled along the surface, until they
are arrested by the temporary cessation of the wind, by vegetation, or by
some other obstruction, and they may, in process of time, accumulate in
large masses, under the lee of rocky projections, buildings, or other barriers
which break the force of the wind.
In these facts we find an important element in the explanation of the sand
drifts, which have half buried the Sphinx and so many other ancient
monuments in that part of Egypt. These drifts, as I have said, are not wholly
from the desert, but in largo proportion from the sea; and, as might be
supposed from the distance they have travelled, they have been long in
gathering. While Egypt was a great and flourishing kingdom, measures
were taken to protect its territory against the encroachment of sand, whether
from the desert or from the Mediterranean; but the foreign conquerors, who
destroyed so many of its religious monuments, did not spare its public
works, and the process of physical degradation undoubtedly began as early
as the Persian invasion. The urgent necessity, which has compelled all the
successive tyrannies of Egypt to keep up some of the canals and other
arrangements for irrigation, was not felt with respect to the advancement of
the sands; for their progress was so slow as hardly to be perceptible in the
Page 689
course of a single reign, and long experience has shown that, from the
natural effect of the inundations, the cultivable soil of the valley is, on the
whole, trenching upon the domain of the desert, not retreating before it.
The oases of the Libyan, as well as of many Asiatic deserts, have no such
safeguards. The sands are fast encroaching upon them, and threaten soon to
engulf them, unless man shall resort to artesian wells and plantations, or to
some other efficient means of checking the advance of this formidable
enemy, in time to save these islands of the waste from final destruction.
Accumulations of sand are, in certain cases, beneficial as a protection
against the ravages of the sea; but, in general, the vicinity, and especially
the shifting of bodies of this material, are destructive to human industry,
and hence, in civilized countries, measures are taken to prevent its spread.
This, however, can be done only where the population is large and
enlightened, and the value of the soil, or of the artificial erections and
improvements upon it, is considerable. Hence in the deserts of Africa and of
Asia, and thee inhabited lands which border on them, no pains are usually
taken to check the drifts, and when once the fields, the houses, the springs,
or the canals of irrigation are covered or choked, the district is abandoned
without a struggle, and surrendered to perpetual desolation. [Footnote: In
parts of the Algerian desert, some efforts are made to retard the advance of
sand dunes which threaten to overwhelm villages. "At Debila," says
Laurent, "the lower parts of the lofty dunes are planted with palms, … but
they are constantly menaced with burial by the sands. The only remedy
employed by the natives consists in little dry walls of crystallized gypsum,
built on the crests of the dunes, together with hedges of dead palm-leaves.
These defensive measures are aided by incessant labor; for every day the
people take up in baskets the sand blown over to them the night before and
carry it back to the other side of the dune."—Memoires sur le Sahara, p.
14.]
natural effect of the inundations, the cultivable soil of the valley is, on the
whole, trenching upon the domain of the desert, not retreating before it.
The oases of the Libyan, as well as of many Asiatic deserts, have no such
safeguards. The sands are fast encroaching upon them, and threaten soon to
engulf them, unless man shall resort to artesian wells and plantations, or to
some other efficient means of checking the advance of this formidable
enemy, in time to save these islands of the waste from final destruction.
Accumulations of sand are, in certain cases, beneficial as a protection
against the ravages of the sea; but, in general, the vicinity, and especially
the shifting of bodies of this material, are destructive to human industry,
and hence, in civilized countries, measures are taken to prevent its spread.
This, however, can be done only where the population is large and
enlightened, and the value of the soil, or of the artificial erections and
improvements upon it, is considerable. Hence in the deserts of Africa and of
Asia, and thee inhabited lands which border on them, no pains are usually
taken to check the drifts, and when once the fields, the houses, the springs,
or the canals of irrigation are covered or choked, the district is abandoned
without a struggle, and surrendered to perpetual desolation. [Footnote: In
parts of the Algerian desert, some efforts are made to retard the advance of
sand dunes which threaten to overwhelm villages. "At Debila," says
Laurent, "the lower parts of the lofty dunes are planted with palms, … but
they are constantly menaced with burial by the sands. The only remedy
employed by the natives consists in little dry walls of crystallized gypsum,
built on the crests of the dunes, together with hedges of dead palm-leaves.
These defensive measures are aided by incessant labor; for every day the
people take up in baskets the sand blown over to them the night before and
carry it back to the other side of the dune."—Memoires sur le Sahara, p.
14.]
Page 690
Sand Dunes and Sand Plains.
Two forms of sand deposit are specially important in European and
American geography. The one is that of dune or shifting hillock upon the
coast, the other that of barren plain in the interior. The coast-dunes are
composed of sand washed up from the depths of the sea by the waves, and
heaped in more or less rounded knolls and undulating ridges by the winds.
The sand with which many plains are covered appears sometimes to have
been deposited upon them while they were yet submerged beneath the sea,
sometimes to have been drifted from the seacoast, and scattered over them
by wind-currents, sometimes to have been washed upon them by running
water. In these latter cases, the deposit, though in itself considerable, is
comparatively narrow in extent and irregular in distribution, while, in the
former, it is often evenly spread over a very wide surface. In all great bodies
of either sort, the silicious grains are the principal constituent, though, when
not resulting from the disintegration of silicious rock and still remaining in
place, they are generally accompanied with a greater or less admixture of
other mineral particles, and of animal and vegetable remains, [Footnote:
Organic constituents, such as comminuted shells, and silicious and
calcareous exuviae of infusorial animals and plants, are sometimes found
mingled in considerable quantities with mineral sands. These are usually the
remains of aquatic vegetables or animals, but not uniformly so, for the
microscopic organisms, whose flinty cases enter so largely into the sand-
beds of the Mark of Brandenburg, are still living and prolific in the dry
earth. See Wittwer, Physikalische Geographic, p. 142. The desert on both
sides of the Nile is inhabited by a land-snail—of which I have counted
eighty, in estimation, on a single shrub barely a foot high—and thousands
of its shells are swept along and finally buried in the drifts by every wind.
Every handful of the sand contains fragments of them. Forchhammer, in
Leonhard und Bronn s Jahrbuch, 1841, p. 8, says of the sand-hills of the
Danish coast: "It is not rare to find, high in the knolls, marine shells, and
Two forms of sand deposit are specially important in European and
American geography. The one is that of dune or shifting hillock upon the
coast, the other that of barren plain in the interior. The coast-dunes are
composed of sand washed up from the depths of the sea by the waves, and
heaped in more or less rounded knolls and undulating ridges by the winds.
The sand with which many plains are covered appears sometimes to have
been deposited upon them while they were yet submerged beneath the sea,
sometimes to have been drifted from the seacoast, and scattered over them
by wind-currents, sometimes to have been washed upon them by running
water. In these latter cases, the deposit, though in itself considerable, is
comparatively narrow in extent and irregular in distribution, while, in the
former, it is often evenly spread over a very wide surface. In all great bodies
of either sort, the silicious grains are the principal constituent, though, when
not resulting from the disintegration of silicious rock and still remaining in
place, they are generally accompanied with a greater or less admixture of
other mineral particles, and of animal and vegetable remains, [Footnote:
Organic constituents, such as comminuted shells, and silicious and
calcareous exuviae of infusorial animals and plants, are sometimes found
mingled in considerable quantities with mineral sands. These are usually the
remains of aquatic vegetables or animals, but not uniformly so, for the
microscopic organisms, whose flinty cases enter so largely into the sand-
beds of the Mark of Brandenburg, are still living and prolific in the dry
earth. See Wittwer, Physikalische Geographic, p. 142. The desert on both
sides of the Nile is inhabited by a land-snail—of which I have counted
eighty, in estimation, on a single shrub barely a foot high—and thousands
of its shells are swept along and finally buried in the drifts by every wind.
Every handful of the sand contains fragments of them. Forchhammer, in
Leonhard und Bronn s Jahrbuch, 1841, p. 8, says of the sand-hills of the
Danish coast: "It is not rare to find, high in the knolls, marine shells, and
Page 691
especially those of the oyster. They are due to the oyster-eater [Haemalopus
ostralegus], which carries his prey to the top of the dunes to devour it." See
also Staring, De Bodem van Nederland, i., p. 821.] and they are also,
usually somewhat changed in consistence by the ever-varying conditions of
temperature and moisture to which they have been exposed since their
deposit. Unless the proportion of these latter ingredients is so large as to
create a considerable adhesiveness in the mass—in which case it can no
longer properly be called sand—it is infertile, and, if not charged with
water, partially agglutinated by iron, lime, or other cement, or confined by
alluvion resting upon it, it is much inclined to drift, whenever, by any
chance, the vegetable network which, in most cases, thinly clothes and at
the same time confines it, is broken. Human industry has not only fixed the
flying dunes by plantations, but, by mixing clay and other tenacious earths
with the superficial stratum of extensive sand plains, and by the application
of fertilizing substances, it has made them abundantly productive of
vegetable life. These latter processes belong to agriculture and not to
geography, and, therefore, are not embraced within the scope of the present
subject. But the preliminary steps, whereby wastes of loose, drifting barren
sands are transformed into wooded knolls and plains, and finally, through
the accummulation of vegetable mould, into arable ground, constitute a
conquest over nature which precedes agriculture—a geographical
revolution—and, therefore, an account of the means by which the change
has been effected belongs properly to the history of man's influence on the
great features of terrestrial surface. I proceed, then, to examine the structure
of dunes, and to describe the warfare man wages with the sand-hills,
striving on the one hand to maintain and even extend them, as a natural
barrier against encroachments of the sea, and, on the other, to check their
moving and wandering propensities, and prevent them from trespassing
upon the fields he has planted and the habitations in which he dwells.
ostralegus], which carries his prey to the top of the dunes to devour it." See
also Staring, De Bodem van Nederland, i., p. 821.] and they are also,
usually somewhat changed in consistence by the ever-varying conditions of
temperature and moisture to which they have been exposed since their
deposit. Unless the proportion of these latter ingredients is so large as to
create a considerable adhesiveness in the mass—in which case it can no
longer properly be called sand—it is infertile, and, if not charged with
water, partially agglutinated by iron, lime, or other cement, or confined by
alluvion resting upon it, it is much inclined to drift, whenever, by any
chance, the vegetable network which, in most cases, thinly clothes and at
the same time confines it, is broken. Human industry has not only fixed the
flying dunes by plantations, but, by mixing clay and other tenacious earths
with the superficial stratum of extensive sand plains, and by the application
of fertilizing substances, it has made them abundantly productive of
vegetable life. These latter processes belong to agriculture and not to
geography, and, therefore, are not embraced within the scope of the present
subject. But the preliminary steps, whereby wastes of loose, drifting barren
sands are transformed into wooded knolls and plains, and finally, through
the accummulation of vegetable mould, into arable ground, constitute a
conquest over nature which precedes agriculture—a geographical
revolution—and, therefore, an account of the means by which the change
has been effected belongs properly to the history of man's influence on the
great features of terrestrial surface. I proceed, then, to examine the structure
of dunes, and to describe the warfare man wages with the sand-hills,
striving on the one hand to maintain and even extend them, as a natural
barrier against encroachments of the sea, and, on the other, to check their
moving and wandering propensities, and prevent them from trespassing
upon the fields he has planted and the habitations in which he dwells.
Page 692
COAST DUNES.
Page 693
Coast dunes are oblong ridges or round hillocks, formed by the action of
the wind upon sands thrown up by the waves on the low beaches of seas,
and sometimes of fresh-water lakes. On most coasts, the supply of sand for
the formation of dunes is derived from tidal waves. The flow of the tide is
more rapid, and consequently its transporting power greater, than that of the
ebb; the momentum, acquired by the heavy particles in rolling in with the
water, tends to carry them even beyond the flow of the waves; and at the
turn of the tide, the water is in a state of repose long enough to allow it to
let fall much of the solid matter it holds in suspension. Hence, on all low,
tide-washed coasts of seas with sandy bottoms, there exist several
conditions favorable to the formation of sand deposits along high-water
mark. [Footnote: There are various reasons why the formation of dunes is
confined to low shores, and this law is so universal, that when bluffs are
surmounted by them, there is always cause to suspect upheaval, or the
removal of a sloping beach in front of the bluff, after the dunes were
formed. Bold shores are usually without a sufficient beach for the
accumulation of large deposits; they are commonly washed by a sea too
deep to bring up sand from its bottom; their abrupt elevation, even if
moderate in amount, would still be too great to allow ordinary winds to lift
the sand above them; and their influence in deadening the wind which
blows towards them would even more effectually prevent the raising of
sand from the beach at their foot. Forchhammer, describing the coast of
Jutland, says that, in high winds, "one can hardly stand upon the dunes,
except when they are near the water line and have been cut down
perpendicularly by the waves. Then the wind is little or not at all felt—a
fact of experience very common on our coasts, observed on all the steep
shore bluffs of 200 feet height, and, in the Faroe Islands, on precipices
2,000 feet high. In heavy gales in those islands, the cattle fly to the very
edge of the cliffs for shelter, and frequently fall over. The wind, impinging
against the vertical wall, creates an ascending current which shoots
the wind upon sands thrown up by the waves on the low beaches of seas,
and sometimes of fresh-water lakes. On most coasts, the supply of sand for
the formation of dunes is derived from tidal waves. The flow of the tide is
more rapid, and consequently its transporting power greater, than that of the
ebb; the momentum, acquired by the heavy particles in rolling in with the
water, tends to carry them even beyond the flow of the waves; and at the
turn of the tide, the water is in a state of repose long enough to allow it to
let fall much of the solid matter it holds in suspension. Hence, on all low,
tide-washed coasts of seas with sandy bottoms, there exist several
conditions favorable to the formation of sand deposits along high-water
mark. [Footnote: There are various reasons why the formation of dunes is
confined to low shores, and this law is so universal, that when bluffs are
surmounted by them, there is always cause to suspect upheaval, or the
removal of a sloping beach in front of the bluff, after the dunes were
formed. Bold shores are usually without a sufficient beach for the
accumulation of large deposits; they are commonly washed by a sea too
deep to bring up sand from its bottom; their abrupt elevation, even if
moderate in amount, would still be too great to allow ordinary winds to lift
the sand above them; and their influence in deadening the wind which
blows towards them would even more effectually prevent the raising of
sand from the beach at their foot. Forchhammer, describing the coast of
Jutland, says that, in high winds, "one can hardly stand upon the dunes,
except when they are near the water line and have been cut down
perpendicularly by the waves. Then the wind is little or not at all felt—a
fact of experience very common on our coasts, observed on all the steep
shore bluffs of 200 feet height, and, in the Faroe Islands, on precipices
2,000 feet high. In heavy gales in those islands, the cattle fly to the very
edge of the cliffs for shelter, and frequently fall over. The wind, impinging
against the vertical wall, creates an ascending current which shoots
Page 694
somewhat past the crest of the rock, and thus the observer or the animal is
protected against the tempest by a barrier of air."-Leonhard und Bronn,
Jahrbuch, 1841, p. 3. The calming, or rather diversion, of the wind by cliffs
extends to a considerable distance in front of them, and no wind would have
sufficient force to raise the sand vertically, parallel to the face of a bluff,
even to the height of twenty feet.] If the land-winds are of greater
frequency, duration, or strength than the sea-winds, the sands left by the
retreating wave will be constantly blown back into the water; but if the
prevailing air-currents are in the opposite direction, the sands will soon be
carried out of the reach of the highest waves, and transported continually
farther and farther into the interior of the land, unless obstructed by high
grounds, vegetation, or other obstacles.
The laws which govern the formation of dunes are substantially these.
We have seen that, under certain conditions, sand is accumulated above
high-water mark on low sea and lake shores. So long as the sand is kept wet
by the spray or by capillary attraction, it is not disturbed by air-currents, but
as soon as the waves retire sufficiently to allow it to dry, it becomes the
sport of the wind, and is driven up the gently sloping beach until it is
arrested by stones, vegetables, or other obstructions, and thus an
accumulation is formed which constitutes the foundation of a dune.
However slight the elevation thus created, it serves to stop or retard the
progress of the sand-grains which are driven against its shoreward face, and
to protect from the further influence of the wind the particles which are
borne beyond it, or rolled over its crest, and fall down behind it. If the shore
above the beach line were perfectly level and straight, the grass or bushes
upon it of equal height, the sand thrown up by the waves uniform in size
and weight of particles as well as in distribution, and if the action of the
wind were steady and regular, a continuous bank would be formed,
everywhere alike in height and cross section. But no such constant
conditions anywhere exist. The banks are curved, broken, unequal in
protected against the tempest by a barrier of air."-Leonhard und Bronn,
Jahrbuch, 1841, p. 3. The calming, or rather diversion, of the wind by cliffs
extends to a considerable distance in front of them, and no wind would have
sufficient force to raise the sand vertically, parallel to the face of a bluff,
even to the height of twenty feet.] If the land-winds are of greater
frequency, duration, or strength than the sea-winds, the sands left by the
retreating wave will be constantly blown back into the water; but if the
prevailing air-currents are in the opposite direction, the sands will soon be
carried out of the reach of the highest waves, and transported continually
farther and farther into the interior of the land, unless obstructed by high
grounds, vegetation, or other obstacles.
The laws which govern the formation of dunes are substantially these.
We have seen that, under certain conditions, sand is accumulated above
high-water mark on low sea and lake shores. So long as the sand is kept wet
by the spray or by capillary attraction, it is not disturbed by air-currents, but
as soon as the waves retire sufficiently to allow it to dry, it becomes the
sport of the wind, and is driven up the gently sloping beach until it is
arrested by stones, vegetables, or other obstructions, and thus an
accumulation is formed which constitutes the foundation of a dune.
However slight the elevation thus created, it serves to stop or retard the
progress of the sand-grains which are driven against its shoreward face, and
to protect from the further influence of the wind the particles which are
borne beyond it, or rolled over its crest, and fall down behind it. If the shore
above the beach line were perfectly level and straight, the grass or bushes
upon it of equal height, the sand thrown up by the waves uniform in size
and weight of particles as well as in distribution, and if the action of the
wind were steady and regular, a continuous bank would be formed,
everywhere alike in height and cross section. But no such constant
conditions anywhere exist. The banks are curved, broken, unequal in
Page 695
elevation; they are sometimes bare, sometimes clothed with vegetables of
different structure and dimensions; the sand thrown up is variable in
quantity and character; and the winds are shifting, gusty, vertical, and often
blowing in very narrow currents. From all these causes, instead of uniform
hills, there rise irregular rows of sand-heaps, and these, as would naturally
be expected, are of a pyramidal, or rather conical shape, and connected at
bottom by more or less continuous ridges of the same material.
Elisee Reclus, in describing the coast dunes of Gascony, observes that
when, as sometimes happens, the sands are not heaped in a continuous,
irregular bulwark, but deposited in isolated hillocks, they have a tendency
to assume a crescent shape, the convexity being turned seawards, or
towards the direction from which the prevailing winds proceed. This fact,
the geological bearing of which is obvious, is not noticed by previous
French writers or even by Andresen, though a semi-lunar outline has been
long generally ascribed to inland dunes. It is, however evident that such a
form would naturally be produced by the action of a wind blowing long in a
given direction upon a mass of loose sand with a fixed centre—such as is
constituted by the shrub or stone around which the sand is first deposited—
and free extremities. On a receding coast, dunes will not attain so great a
height as on more secure shores, because they are undermined and carried
off before they have time to reach their greatest dimensions. Hence, while at
sheltered points in South-western France, there are dunes three hundred feet
or more in height, those on the Frisic Islands and the exposed parts of the
coast of Schleswig-Holstein range only from twenty to one hundred feet.
On the western shores of Africa, it is said that they sometimes attain an
elevation of six hundred feet. This is one of the very few points known to
geographers where desert sands are advancing seawards, [Footnote: "On the
west coast of Africa the dunes are drifting seawards, and always receiving
new accessions from the Sahara. They are constantly advancing out into the
different structure and dimensions; the sand thrown up is variable in
quantity and character; and the winds are shifting, gusty, vertical, and often
blowing in very narrow currents. From all these causes, instead of uniform
hills, there rise irregular rows of sand-heaps, and these, as would naturally
be expected, are of a pyramidal, or rather conical shape, and connected at
bottom by more or less continuous ridges of the same material.
Elisee Reclus, in describing the coast dunes of Gascony, observes that
when, as sometimes happens, the sands are not heaped in a continuous,
irregular bulwark, but deposited in isolated hillocks, they have a tendency
to assume a crescent shape, the convexity being turned seawards, or
towards the direction from which the prevailing winds proceed. This fact,
the geological bearing of which is obvious, is not noticed by previous
French writers or even by Andresen, though a semi-lunar outline has been
long generally ascribed to inland dunes. It is, however evident that such a
form would naturally be produced by the action of a wind blowing long in a
given direction upon a mass of loose sand with a fixed centre—such as is
constituted by the shrub or stone around which the sand is first deposited—
and free extremities. On a receding coast, dunes will not attain so great a
height as on more secure shores, because they are undermined and carried
off before they have time to reach their greatest dimensions. Hence, while at
sheltered points in South-western France, there are dunes three hundred feet
or more in height, those on the Frisic Islands and the exposed parts of the
coast of Schleswig-Holstein range only from twenty to one hundred feet.
On the western shores of Africa, it is said that they sometimes attain an
elevation of six hundred feet. This is one of the very few points known to
geographers where desert sands are advancing seawards, [Footnote: "On the
west coast of Africa the dunes are drifting seawards, and always receiving
new accessions from the Sahara. They are constantly advancing out into the
Page 696
sea."—Naumann, Geognosie, ii., p.1172.] and here they rise to the greatest
altitude to which sand-grains can be carried by the wind. The hillocks, once
deposited, are held together and kept in shape, partly by mere gravity, and
partly by the slight cohesion of the lime, clay, and organic matter mixed
with the sand; and it is observed that, from capillary attraction, evaporation
from lower strata, and retention of rain-water, they are always moist a little
below the surface. [Footnote: "Dunes are always full of water, from the
action of capillary attraction. Upon the summits, one seldom needs to dig
more than a foot to find the sand moist, and in the depressions, fresh water
is met with near the surface."—Forchhammer, in Leonhard and Bronx, for
1841, p.5, note. On the other hand, Andresen, who has very carefully
investigated this as well as all other dune phenomena, maintains that the
humidity of the sand ridges cannot be derived from capillary attraction. He
found by experiment that a heap of drift-sand was not moistened to a
greater height than eight and a half inches, after standing with its base a
whole night in water. He states the minimum of water contained by the sand
of the dunes, one foot below the surface, after a long drought, at two per
cent, the maximum, after a rainy month, at four per cent. At greater depths
the quantity is larger. The hygroscopicity of the sand of the coast of Jutland
he found to be thirty-three per cent, by measure, or 21.5 by weight. The
annual precipitation on that coast is twenty-seven inches, and as the
evaporation is about the same, he argues that rain-water does not penetrate
far beneath the surface of the dunes, and concludes that their humidity can
be explained only by evaporation from below.—Om Klitformationen, pp.
106-110. In the dunes of Algeria, water in so abundant that wells are
constantly dug in them at high points on their surface. They are sunk to the
depth of three or four inches only, and the water rises to the height of a
metre in them.—Laurent, Memoire sur le Sahara, pp. 11, 12, 13. The same
writer observes (p. 14) that the 'hollows in the dunes are planted with palms
which find moisture enough a little below the surface. It would hence seem
altitude to which sand-grains can be carried by the wind. The hillocks, once
deposited, are held together and kept in shape, partly by mere gravity, and
partly by the slight cohesion of the lime, clay, and organic matter mixed
with the sand; and it is observed that, from capillary attraction, evaporation
from lower strata, and retention of rain-water, they are always moist a little
below the surface. [Footnote: "Dunes are always full of water, from the
action of capillary attraction. Upon the summits, one seldom needs to dig
more than a foot to find the sand moist, and in the depressions, fresh water
is met with near the surface."—Forchhammer, in Leonhard and Bronx, for
1841, p.5, note. On the other hand, Andresen, who has very carefully
investigated this as well as all other dune phenomena, maintains that the
humidity of the sand ridges cannot be derived from capillary attraction. He
found by experiment that a heap of drift-sand was not moistened to a
greater height than eight and a half inches, after standing with its base a
whole night in water. He states the minimum of water contained by the sand
of the dunes, one foot below the surface, after a long drought, at two per
cent, the maximum, after a rainy month, at four per cent. At greater depths
the quantity is larger. The hygroscopicity of the sand of the coast of Jutland
he found to be thirty-three per cent, by measure, or 21.5 by weight. The
annual precipitation on that coast is twenty-seven inches, and as the
evaporation is about the same, he argues that rain-water does not penetrate
far beneath the surface of the dunes, and concludes that their humidity can
be explained only by evaporation from below.—Om Klitformationen, pp.
106-110. In the dunes of Algeria, water in so abundant that wells are
constantly dug in them at high points on their surface. They are sunk to the
depth of three or four inches only, and the water rises to the height of a
metre in them.—Laurent, Memoire sur le Sahara, pp. 11, 12, 13. The same
writer observes (p. 14) that the 'hollows in the dunes are planted with palms
which find moisture enough a little below the surface. It would hence seem
Page 697
that proposal to fix the dunes which are supposed to threaten the Suez
Canal, by planting the maratime pine and other trees upon them, is not
altogether so absurd as it has been thought to be by some of those
disinterested philanthropists of other nations who were distressed with fears
that French capitalists would lose the money they had invested in that great
undertaking. Ponds of water are often found in the depression between the
sand-hills of the dune chains in the North American desert.]
By successive accumulations, they gradually rise to the height of thirty,
fifty, sixty, or a hundred feet, and sometimes even much higher. Strong
winds, instead of adding to their elevation, sweep off loose particles from
their surface, and these, with others blown over or between them, build up a
second row of dunes, and so on according to the character of the wind, the
supply and consistence of the sand, and the face of the country. In this way
is formed a belt of sand-dunes, irregularly dispersed and varying much in
height and dimensions, and sometimes many miles in breadth. On the Island
of Sylt, in the German Sea, where there are several rows, the width of the
belt is from half a mile to a mile. There are similar ranges on the coast of
Holland, exceeding two miles in breadth, while at the mouths of the Nile
they form a zone not less than ten miles wide. The base of some of the
dunes in the Delta of the Nile is reached by the river during the annual
inundation, and the infiltration of the water, which contains lime, has
converted the lower strata into a silicious limestone, or rather a calcarous
sandstone, and thus afforded an opportunity of studying the structure of that
rock in a locality where its origin and mode of aggregation and
solidification are known.
The tide, though a usual, is by no means a necessary condition for the
accumulations of sand out of which dunes are formed. The Baltic and the
Mediterranean are almost tideless seas, but there are vast ranges of dunes on
the Russian and Prussian coasts of the Baltic and at the mouths of the Nile
Canal, by planting the maratime pine and other trees upon them, is not
altogether so absurd as it has been thought to be by some of those
disinterested philanthropists of other nations who were distressed with fears
that French capitalists would lose the money they had invested in that great
undertaking. Ponds of water are often found in the depression between the
sand-hills of the dune chains in the North American desert.]
By successive accumulations, they gradually rise to the height of thirty,
fifty, sixty, or a hundred feet, and sometimes even much higher. Strong
winds, instead of adding to their elevation, sweep off loose particles from
their surface, and these, with others blown over or between them, build up a
second row of dunes, and so on according to the character of the wind, the
supply and consistence of the sand, and the face of the country. In this way
is formed a belt of sand-dunes, irregularly dispersed and varying much in
height and dimensions, and sometimes many miles in breadth. On the Island
of Sylt, in the German Sea, where there are several rows, the width of the
belt is from half a mile to a mile. There are similar ranges on the coast of
Holland, exceeding two miles in breadth, while at the mouths of the Nile
they form a zone not less than ten miles wide. The base of some of the
dunes in the Delta of the Nile is reached by the river during the annual
inundation, and the infiltration of the water, which contains lime, has
converted the lower strata into a silicious limestone, or rather a calcarous
sandstone, and thus afforded an opportunity of studying the structure of that
rock in a locality where its origin and mode of aggregation and
solidification are known.
The tide, though a usual, is by no means a necessary condition for the
accumulations of sand out of which dunes are formed. The Baltic and the
Mediterranean are almost tideless seas, but there are vast ranges of dunes on
the Russian and Prussian coasts of the Baltic and at the mouths of the Nile
Page 698
and many other points on the shores of the Mediterranean. The vast shoals
in the latter sea, known to the ancients as the Greater and Lesser Syrtis, are
of marine origin. They are still filling up with sand, washed up from greater
depths, or sometimes drifted from the coast in small quantities, and will
probably be converted, at some future period, into dry land covered with
sand-hills. There are also extensive ranges of dunes upon the eastern shores
of the Caspian, and at the southern, or rather south-eastern, extremity of
Lake Michigan. [Footnote: The careful observations of Colonel J. D.
Graham, of the United States Army, show a tide of about three inches in
Lake Michigan. See "A Lunar Tidal Wave in the North American Lakes,"
demonstrated by Lieut.-Colonel J. D. Graham, in the fourteenth volume of
the Proceedings of the American Association for the Advancement of
Science.] There is no doubt that this latter lake formerly extended much
farther in that direction, but its southern portion has gradually shoaled and
at last been converted into solid land, in consequence of the prevalence of
the north-west winds. These blow over the lake a large part of the year, and
create a southwardly set of the currents, which wash up sand from the bed
of the lake and throw it on shore. Sand is taken up from the beach at
Michigan City by every wind from that quarter, and, after a heavy blow of
some hours' duration, sand ridges may be observed on the north side of the
fences, like the snow wreaths deposited by a drifting wind in winter. Some
of the particles are carried back by contrary winds, but most of them lodge
on or behind the dunes, or in the moist soil near the lake, or are entangled
by vegetables, and tend permanently to elevate the level. Like effects are
produced by constant sea-winds, and dunes will generally be formed on all
low coasts where such prevail, whether in tideless or in tidal waters.
Jobard thus describes the modus operandi, under ordinary circumstances,
at the mouths of the Nile, where a tide can scarcely be detected: "When a
wave breaks, it deposits an almost imperceptible line of fine sand. The next
wave brings also its contribution, and shoves the preceding line a little
in the latter sea, known to the ancients as the Greater and Lesser Syrtis, are
of marine origin. They are still filling up with sand, washed up from greater
depths, or sometimes drifted from the coast in small quantities, and will
probably be converted, at some future period, into dry land covered with
sand-hills. There are also extensive ranges of dunes upon the eastern shores
of the Caspian, and at the southern, or rather south-eastern, extremity of
Lake Michigan. [Footnote: The careful observations of Colonel J. D.
Graham, of the United States Army, show a tide of about three inches in
Lake Michigan. See "A Lunar Tidal Wave in the North American Lakes,"
demonstrated by Lieut.-Colonel J. D. Graham, in the fourteenth volume of
the Proceedings of the American Association for the Advancement of
Science.] There is no doubt that this latter lake formerly extended much
farther in that direction, but its southern portion has gradually shoaled and
at last been converted into solid land, in consequence of the prevalence of
the north-west winds. These blow over the lake a large part of the year, and
create a southwardly set of the currents, which wash up sand from the bed
of the lake and throw it on shore. Sand is taken up from the beach at
Michigan City by every wind from that quarter, and, after a heavy blow of
some hours' duration, sand ridges may be observed on the north side of the
fences, like the snow wreaths deposited by a drifting wind in winter. Some
of the particles are carried back by contrary winds, but most of them lodge
on or behind the dunes, or in the moist soil near the lake, or are entangled
by vegetables, and tend permanently to elevate the level. Like effects are
produced by constant sea-winds, and dunes will generally be formed on all
low coasts where such prevail, whether in tideless or in tidal waters.
Jobard thus describes the modus operandi, under ordinary circumstances,
at the mouths of the Nile, where a tide can scarcely be detected: "When a
wave breaks, it deposits an almost imperceptible line of fine sand. The next
wave brings also its contribution, and shoves the preceding line a little
Page 699
higher. As soon as the particles are fairly out of the reach of the water they
are dried by the heat of the burning sun, and immediately seized by the
wind and rolled or borne farther inland. The gravel is not thrown out by the
waves, but rolls backwards and forwards until it is worn down to the state
of fine sand, when it, in its turn, is cast upon the land and taken up by the
wind." [Footnote: Staring, De Bodun van Nederland, i., p. 327, note.] This
description applies only to the common every-day action of wind and water;
but just in proportion to the increasing force of the wind and the waves,
there is an increase in the quantity of sand, and in the magnitude of the
particles carried off from the beach by it, and, of course, every storm in a
landward direction adds sensibly to the accumulation upon the shore.
Sand Banks.
Although dunes, properly so called, are found only on dry land and above
ordinary high-water mark, and owe their elevation and structure to the
action of the wind, yet, upon many shelving coasts, accumulations of sand
much resembling dunes are formed under water at some distance from the
shore by the oscillations of the waves, and are well known by the name of
sand banks. They are usually rather ridges than banks, of moderate
inclination, and with the steepest slope seawards, [Footnote: Kohl, Inseln
und Marschen Schleswig Holsteins, ii., p. 33. From a drawing in Andresen,
Om Klitformationen, p. 24, it would appear that on the Schleswig coast the
surf-formed banks have the steepest slope landwards, those farther from the
shore, as stated in the text.] and their form differs little from that of dunes
except in this last particular and in being lower and more continuous. Upon
the western coast of the island of Amrum, for example, there are three rows
of such banks, the summits of which are at a distance of perhaps a couple of
miles from each other; so that, including the width of the banks themselves,
the spaces between them, and the breadth of the zone of dunes upon the
are dried by the heat of the burning sun, and immediately seized by the
wind and rolled or borne farther inland. The gravel is not thrown out by the
waves, but rolls backwards and forwards until it is worn down to the state
of fine sand, when it, in its turn, is cast upon the land and taken up by the
wind." [Footnote: Staring, De Bodun van Nederland, i., p. 327, note.] This
description applies only to the common every-day action of wind and water;
but just in proportion to the increasing force of the wind and the waves,
there is an increase in the quantity of sand, and in the magnitude of the
particles carried off from the beach by it, and, of course, every storm in a
landward direction adds sensibly to the accumulation upon the shore.
Sand Banks.
Although dunes, properly so called, are found only on dry land and above
ordinary high-water mark, and owe their elevation and structure to the
action of the wind, yet, upon many shelving coasts, accumulations of sand
much resembling dunes are formed under water at some distance from the
shore by the oscillations of the waves, and are well known by the name of
sand banks. They are usually rather ridges than banks, of moderate
inclination, and with the steepest slope seawards, [Footnote: Kohl, Inseln
und Marschen Schleswig Holsteins, ii., p. 33. From a drawing in Andresen,
Om Klitformationen, p. 24, it would appear that on the Schleswig coast the
surf-formed banks have the steepest slope landwards, those farther from the
shore, as stated in the text.] and their form differs little from that of dunes
except in this last particular and in being lower and more continuous. Upon
the western coast of the island of Amrum, for example, there are three rows
of such banks, the summits of which are at a distance of perhaps a couple of
miles from each other; so that, including the width of the banks themselves,
the spaces between them, and the breadth of the zone of dunes upon the
Page 700
land, the belt of moving sands on that coast is probably not less than eight
miles wide.
Under ordinary circumstances, sand banks are always rolling, landwards,
and they compose the magazine from which the material for the dunes is
derived. [Footnote: Sand banks sometimes connect themselves with the
coast at both ends, and thus cut off a portion of the sea. In this case, as well
as when salt water is enclosed by sea-dikes, the water thus separated from
the ocean gradually becomes fresh, or at least brackish. The Haffs, or large
expanses of fresh water in Eastern Prussia—which are divided from the
Baltic by narrow sand banks called Nehrungen, or, at sheltered points of the
coast, by fluviatile deposits called Werders—all have one or more open
passages, through which the water of the rivers that supply them at last
finds its way to the sea.] The dunes, in fact, are but aquatic sand banks
transferred to dry land. The laws of their formation are closely analogous,
because the action of the two fluids, by which they are respectively
accumulated and built up, is very similar when brought to bear upon loose
particles of solid matter. It would, indeed, seem that the slow and
comparatively regular movements of the heavy, unelastic water ought to
affect such particles very differently from the sudden and fitful impulses of
the light and elastic air. But the velocity of the wind currents gives them a
mechanical force approximating to that of the slower waves, and, however
difficult it may be to explain all the phenomena that characterize the
structure of the dunes, observation has proved that it is nearly identical with
that of submerged sand banks. [Footnote: Forchhammer ascribes the
resemblance between the furrowing of the dune sands and the beach ripples,
not to the similarity of the effect of wind and water upon sand, but wholly
to the action of the wind; in the first instance, directly, in the latter, through
the water. "The wind-ripples on the surface of the dunes precisely resemble
the water-ripples of sand flats occasionally overflowed by the sea; and with
the closest scrutiny, I have never been able to detect the slightest difference
miles wide.
Under ordinary circumstances, sand banks are always rolling, landwards,
and they compose the magazine from which the material for the dunes is
derived. [Footnote: Sand banks sometimes connect themselves with the
coast at both ends, and thus cut off a portion of the sea. In this case, as well
as when salt water is enclosed by sea-dikes, the water thus separated from
the ocean gradually becomes fresh, or at least brackish. The Haffs, or large
expanses of fresh water in Eastern Prussia—which are divided from the
Baltic by narrow sand banks called Nehrungen, or, at sheltered points of the
coast, by fluviatile deposits called Werders—all have one or more open
passages, through which the water of the rivers that supply them at last
finds its way to the sea.] The dunes, in fact, are but aquatic sand banks
transferred to dry land. The laws of their formation are closely analogous,
because the action of the two fluids, by which they are respectively
accumulated and built up, is very similar when brought to bear upon loose
particles of solid matter. It would, indeed, seem that the slow and
comparatively regular movements of the heavy, unelastic water ought to
affect such particles very differently from the sudden and fitful impulses of
the light and elastic air. But the velocity of the wind currents gives them a
mechanical force approximating to that of the slower waves, and, however
difficult it may be to explain all the phenomena that characterize the
structure of the dunes, observation has proved that it is nearly identical with
that of submerged sand banks. [Footnote: Forchhammer ascribes the
resemblance between the furrowing of the dune sands and the beach ripples,
not to the similarity of the effect of wind and water upon sand, but wholly
to the action of the wind; in the first instance, directly, in the latter, through
the water. "The wind-ripples on the surface of the dunes precisely resemble
the water-ripples of sand flats occasionally overflowed by the sea; and with
the closest scrutiny, I have never been able to detect the slightest difference
Page 701
between them. This is easily explained by the fact, that the water-ripples are
produced by the action of light wind on the water which only transmits the
air-waves to the sand."—Leonhard und Bronn, 1841, pp. 7, 8.] The
differences of form are generally ascribable to the greater number and
variety of surface accidents of the ground on which the sand hills of the
land are built up, and to the more frequent changes, and wider variety of
direction, in the courses of the wind.
CHARACTER OF DUNE SAND.
"Dune sand," says Staring, "consists of well-rounded grains of quartz, more
or less colored by iron, and often mingled with fragments of shells, small
indeed, but still visible to the naked eye. [Footnote: According to the French
authorities, the dunes of France are not always composed of quartzose sand.
"The dune sands" of different characters, says Bremontier, "partake of the
nature of the different materials which compose them. At certain points on
the coast of Normandy they are found to be purely calcareous; they are of
mixed composition on the shores of Brittany and Saintonge, and generally
quartzose between the mouth of the Gironde and that of the Adour."—
Memoire sur les Dunes, Annales des Ponts et Chaussees, t. vii., 1833, 1er
semestre, p. 146.
In the dunes of Long Island and of Jutland, there are considerable veins
composed almost wholly of garnet. For a very full examination of the
mechanical and chemical composition of the dune sands of Jutland, see
Andresen, Om Klitformationen, p. 110. Fraas informs us, Aus dem Orient,
pp. 176, 177, that the dune sands of the Egyptian coast arise from the
disintegration of the calcareous sandstone of the same region. This
sandstone, composed in a large proportion of detritus of both land and sea
shells mingled with quartz sand, appears to have been consolidated under
produced by the action of light wind on the water which only transmits the
air-waves to the sand."—Leonhard und Bronn, 1841, pp. 7, 8.] The
differences of form are generally ascribable to the greater number and
variety of surface accidents of the ground on which the sand hills of the
land are built up, and to the more frequent changes, and wider variety of
direction, in the courses of the wind.
CHARACTER OF DUNE SAND.
"Dune sand," says Staring, "consists of well-rounded grains of quartz, more
or less colored by iron, and often mingled with fragments of shells, small
indeed, but still visible to the naked eye. [Footnote: According to the French
authorities, the dunes of France are not always composed of quartzose sand.
"The dune sands" of different characters, says Bremontier, "partake of the
nature of the different materials which compose them. At certain points on
the coast of Normandy they are found to be purely calcareous; they are of
mixed composition on the shores of Brittany and Saintonge, and generally
quartzose between the mouth of the Gironde and that of the Adour."—
Memoire sur les Dunes, Annales des Ponts et Chaussees, t. vii., 1833, 1er
semestre, p. 146.
In the dunes of Long Island and of Jutland, there are considerable veins
composed almost wholly of garnet. For a very full examination of the
mechanical and chemical composition of the dune sands of Jutland, see
Andresen, Om Klitformationen, p. 110. Fraas informs us, Aus dem Orient,
pp. 176, 177, that the dune sands of the Egyptian coast arise from the
disintegration of the calcareous sandstone of the same region. This
sandstone, composed in a large proportion of detritus of both land and sea
shells mingled with quartz sand, appears to have been consolidated under
Page 702
water during an ancient period of subsidence. A later upheaval brought it to
or near the surface, when it was more or less disintegrated by the action of
the waves and by meteoric influences—a process still going on—and it is
now again subsiding with the coast it rests on.
The calcareous sand arising from the comminution of corals forms dunes
on some of the West India Islands.—Agassiz, Bulletin of the Museum of
Comparative Zoology, vol. i.] These fragments are not constant constituents
of dune sand. They are sometimes found at the very summits of the
hillocks, as at Overveen; in the King's Dune, near Egmond, they form a
coarse, calcareous gravel very largely distributed through the sand, while
the interior dunes between Haarlem and Warmond exhibit no trace of them.
It is yet undecided whether the presence or absence of these fragments is
determined by the period of the formation of the dunes, or whether it
depends on a difference in the process by which different dunes have been
accumulated. Land shells, such as snails, for example, are found on the
surface of the dunes in abundance, and many of the shelly fragments in the
interior of the hillocks may be derived from the same source." [Footnote:
De Bodem van Nederland, i., p. 323.]
Sand concretions form within the dunes and especially in the depressions
between them. These are sometimes so extensive and impervious as to
retain a sufficient supply of water to feed perennial springs, and to form
small permanent ponds, and they are a great impediment to the penetration
of roots, and consequently to the growth of trees planted, or germinating
from self-sown seeds, upon the dunes. [Footnote: Staring, De Bodem van
Nederland, i., p.317. See also Bergsoe, Reventlov's Virksomhed, ii., p. 11.
"In the sand-hill ponds mentioned in the text, there is a vigourous growth
of bog plants accompanied with the formation of peat, which goes on
regularly as long as the dune sand does not drift. But if the surface of the
or near the surface, when it was more or less disintegrated by the action of
the waves and by meteoric influences—a process still going on—and it is
now again subsiding with the coast it rests on.
The calcareous sand arising from the comminution of corals forms dunes
on some of the West India Islands.—Agassiz, Bulletin of the Museum of
Comparative Zoology, vol. i.] These fragments are not constant constituents
of dune sand. They are sometimes found at the very summits of the
hillocks, as at Overveen; in the King's Dune, near Egmond, they form a
coarse, calcareous gravel very largely distributed through the sand, while
the interior dunes between Haarlem and Warmond exhibit no trace of them.
It is yet undecided whether the presence or absence of these fragments is
determined by the period of the formation of the dunes, or whether it
depends on a difference in the process by which different dunes have been
accumulated. Land shells, such as snails, for example, are found on the
surface of the dunes in abundance, and many of the shelly fragments in the
interior of the hillocks may be derived from the same source." [Footnote:
De Bodem van Nederland, i., p. 323.]
Sand concretions form within the dunes and especially in the depressions
between them. These are sometimes so extensive and impervious as to
retain a sufficient supply of water to feed perennial springs, and to form
small permanent ponds, and they are a great impediment to the penetration
of roots, and consequently to the growth of trees planted, or germinating
from self-sown seeds, upon the dunes. [Footnote: Staring, De Bodem van
Nederland, i., p.317. See also Bergsoe, Reventlov's Virksomhed, ii., p. 11.
"In the sand-hill ponds mentioned in the text, there is a vigourous growth
of bog plants accompanied with the formation of peat, which goes on
regularly as long as the dune sand does not drift. But if the surface of the
Page 703
dunes is broken, the sand blows into the ponds, covers the peat, and puts
and end to its formation. When, in the course of time, marine currents cut
away the coast, the dunes move landwards and fill up the ponds and thus
are formed the remarkable strata of fossile peat called Martorv, which
appears to be unknown to the geologists of other parts of Europe." —
Forchhammer, in Leonhard und Bronn, 1841, p. 18. Martorv has a specific
gravity thrice as great as that of ordinary peat in consequence of the
pressure of the sand.—Asbjornsen, Torv og Torvdrift, p.26.]
Interior Structure of Dunes.
The interior structure of the dunes, the arrangement of their particles, is
not, as might be expected, that of an unorganized, confused heap, but they
show a strong tendency to stratification. This is a point of much geological
interest, because it indicates that sandstone may owe its stratified character
to the action of other forces as well as of water. The origin and peculiar
character of these layers are due to a variety of causes.
For example, a south-west wind and current may deposit upon a dune a
stratum of a given color and mineral composition, and this may be
succeeded by a north-west wind and current, bringing with them particles of
a different hue, constitution, and origin. Again, if we suppose a violent
tempest to strew the beach with sand-grains very different in magnitude and
specific gravity, and, after the sand is dry, to be succeeded by a gentle
breeze, it is evident that only the lighter particles will be taken up and
carried to the dunes. If, after some time, the wind freshens, heavier grains
will be transported and deposited on the former, and a still stronger
succeeding gale will roll up yet larger kernels. Each of these deposits will
form a stratum. If we suppose the tempest to be followed, after the sand is
dry, not by a gentle breeze, but by a wind powerful enough to lift at the
same time particles of very various magnitudes and weights, the heaviest
and end to its formation. When, in the course of time, marine currents cut
away the coast, the dunes move landwards and fill up the ponds and thus
are formed the remarkable strata of fossile peat called Martorv, which
appears to be unknown to the geologists of other parts of Europe." —
Forchhammer, in Leonhard und Bronn, 1841, p. 18. Martorv has a specific
gravity thrice as great as that of ordinary peat in consequence of the
pressure of the sand.—Asbjornsen, Torv og Torvdrift, p.26.]
Interior Structure of Dunes.
The interior structure of the dunes, the arrangement of their particles, is
not, as might be expected, that of an unorganized, confused heap, but they
show a strong tendency to stratification. This is a point of much geological
interest, because it indicates that sandstone may owe its stratified character
to the action of other forces as well as of water. The origin and peculiar
character of these layers are due to a variety of causes.
For example, a south-west wind and current may deposit upon a dune a
stratum of a given color and mineral composition, and this may be
succeeded by a north-west wind and current, bringing with them particles of
a different hue, constitution, and origin. Again, if we suppose a violent
tempest to strew the beach with sand-grains very different in magnitude and
specific gravity, and, after the sand is dry, to be succeeded by a gentle
breeze, it is evident that only the lighter particles will be taken up and
carried to the dunes. If, after some time, the wind freshens, heavier grains
will be transported and deposited on the former, and a still stronger
succeeding gale will roll up yet larger kernels. Each of these deposits will
form a stratum. If we suppose the tempest to be followed, after the sand is
dry, not by a gentle breeze, but by a wind powerful enough to lift at the
same time particles of very various magnitudes and weights, the heaviest
Page 704
will often lodge on the dune while the lighter will be carried farther. This
would produce a stratum of coarse sand, and the same effect might result
from the blowing away of light particles out of a mixed layer, while the
heavier remained undisturbed. [Footnote: The lower strata must be older
than the superficial layers, and the particles which compose them may in
time become more disintegrated, and therefore finer than those deposited
later and above them.
Hull ingeniously suggests that, besides other changes, fine sand
intermixed with or deposited above a coarser stratum, as well as the minute
particles resulting from the disintegration of the grains of the latter, may be
carried by rain in the case of dunes, or by the ordinary action or sea-water
in that of sand-banks, down through the interstices in the coarser layer, and
thus the relative position of sand and gravel may be changed.—Oorsprong
der Hollandsche Duinen, p. 103.]
Still another cause of apparent stratification may be found in the
occasional interposition of a thin layer of leaves or other vegetable remains
between successive deposits, and this I imagine to be more frequent than
has been generally supposed. Some geologists have thought that the sand
strata of dunes are of annual formation; [Footnote: Schomann, Geologische
Wanderungen durch die Preussischen Ost-See Provinzen, 1869, p. 81.] but
the autumnal deposit of foliage from neighboring trees and shrubs furnishes
a more probable explanation of the division of the sand-heaps into regular
layers.
A late distinguished American admiral communicated to me an
interesting observation made by him at San Francisco, which has an
important bearing on the arrangement of the particles of sand in dunes and
other irregular accumulations of that substance. In laying out a navy-yard at
that port, a large quantity of earthy material was removed from the dunes
would produce a stratum of coarse sand, and the same effect might result
from the blowing away of light particles out of a mixed layer, while the
heavier remained undisturbed. [Footnote: The lower strata must be older
than the superficial layers, and the particles which compose them may in
time become more disintegrated, and therefore finer than those deposited
later and above them.
Hull ingeniously suggests that, besides other changes, fine sand
intermixed with or deposited above a coarser stratum, as well as the minute
particles resulting from the disintegration of the grains of the latter, may be
carried by rain in the case of dunes, or by the ordinary action or sea-water
in that of sand-banks, down through the interstices in the coarser layer, and
thus the relative position of sand and gravel may be changed.—Oorsprong
der Hollandsche Duinen, p. 103.]
Still another cause of apparent stratification may be found in the
occasional interposition of a thin layer of leaves or other vegetable remains
between successive deposits, and this I imagine to be more frequent than
has been generally supposed. Some geologists have thought that the sand
strata of dunes are of annual formation; [Footnote: Schomann, Geologische
Wanderungen durch die Preussischen Ost-See Provinzen, 1869, p. 81.] but
the autumnal deposit of foliage from neighboring trees and shrubs furnishes
a more probable explanation of the division of the sand-heaps into regular
layers.
A late distinguished American admiral communicated to me an
interesting observation made by him at San Francisco, which has an
important bearing on the arrangement of the particles of sand in dunes and
other irregular accumulations of that substance. In laying out a navy-yard at
that port, a large quantity of earthy material was removed from the dunes
Page 705
and other hillocks and carted to a low piece of ground which required filling
up. Sand of various characters, fine and coarse gravel, and common earth
were dropped promiscuously by the carts as accident or convenience
dictated, and of course they were all confusedly intermixed. Some time
after, when the new ground was consolidated, various excavations were
made in it, and the different materials of which the filling was composed
were found to be stratified with considerable regularity, according to their
specific gravity.
Two explanations of this remarkable fact suggest themselves to me,
which, however, do not perhaps exclude others. San Francisco is subject to
earthquakes, and though violent or even sensible shocks are not very
frequent, it is highly probable that, as is shown to be the case in many other
countries, by late seismological observations, there are, in the course of the
year, a great number of slight shocks which escape unscientific observation.
A frequent repetition of slight tremblings of the earth would, like any other
moderate mechanical agitation, probably produce the separation of a
miscellaneous mass, like that described, into distinct layers. Again, the
Pacific coast, like all others upon an open sea, is exposed to incessant
concussion from the shock of the waves, which is repeated many thousand
times a day. This concussion is often sensibly felt by the observer, and it
seems not in the least improbable that the agitation may have tended to
produce a stratified arrangement in the case at San Francisco, as well as in
all coast dunes and other accumulations of loose mineral material in similar
situations. Kohl observes that the shore on the landward side of the files of
dunes often trembles from the shock of the waves on the beach, [Footnote:
Inseln und Marschen, etc., ii., p. 34.] and Villeneuve established by careful
experiment that at Dunkerque the ground is sensibly agitated by the same
cause, in stormy weather, to a distance of more than a mile from the sea.
up. Sand of various characters, fine and coarse gravel, and common earth
were dropped promiscuously by the carts as accident or convenience
dictated, and of course they were all confusedly intermixed. Some time
after, when the new ground was consolidated, various excavations were
made in it, and the different materials of which the filling was composed
were found to be stratified with considerable regularity, according to their
specific gravity.
Two explanations of this remarkable fact suggest themselves to me,
which, however, do not perhaps exclude others. San Francisco is subject to
earthquakes, and though violent or even sensible shocks are not very
frequent, it is highly probable that, as is shown to be the case in many other
countries, by late seismological observations, there are, in the course of the
year, a great number of slight shocks which escape unscientific observation.
A frequent repetition of slight tremblings of the earth would, like any other
moderate mechanical agitation, probably produce the separation of a
miscellaneous mass, like that described, into distinct layers. Again, the
Pacific coast, like all others upon an open sea, is exposed to incessant
concussion from the shock of the waves, which is repeated many thousand
times a day. This concussion is often sensibly felt by the observer, and it
seems not in the least improbable that the agitation may have tended to
produce a stratified arrangement in the case at San Francisco, as well as in
all coast dunes and other accumulations of loose mineral material in similar
situations. Kohl observes that the shore on the landward side of the files of
dunes often trembles from the shock of the waves on the beach, [Footnote:
Inseln und Marschen, etc., ii., p. 34.] and Villeneuve established by careful
experiment that at Dunkerque the ground is sensibly agitated by the same
cause, in stormy weather, to a distance of more than a mile from the sea.
Page 706
The eddies of strong winds between the hillocks must also occasion
disturbances and re-arrangements of the sand layers, and it seems possible
that the irregular thickness and the strange contortions of the strata of the
sandstone at Petra may be due to some such cause. A curious observation of
Professor Forchhammer suggests an explanation of another peculiarity in
the structure of the sandstone of Mount Seir. He describes dunes in Jutland,
composed of yellow quartzose sand intermixed with black titanian iron.
When the wind blows over the surface of the dunes, it furrows the sand with
alternate ridges and depressions, ripples, in short, like those of water. The
swells, the dividing ridges of the system of sand ripples, are composed of
the light grains of quartz, while the heavier iron rolls into the depressions
between, and thus the whole surface of the dune appears as if covered with
a fine black network.
The sea side of dunes, being more exposed to the caprices of the wind, is
more irregular in form than the lee or land side, where the arrangement of
the particles is affected by fewer disturbing and conflicting influences.
Hence, the stratification of the windward slope is somewhat confused,
while the sand on the lee side is found to be disposed in more regular beds,
inclining landwards, and with the largest particles lowest, where their
greater weight would naturally carry them. The lee side of the dunes, being
thus formed of sand deposited according to the laws of gravity, is very
uniform in its slope, which, according to Forchhammer, varies little from an
angle of 30 degrees with the horizon, while the more exposed and irregular
weather side lies at an inclination of from 5 degrees to 10 degrees. When,
however, the outer tier of dunes is formed so near the waterline as to be
exposed to the immediate action of the waves, it is undermined, and the
face of the hill is very steep and sometimes nearly perpendicular.
Geological Importance of Dunes.
disturbances and re-arrangements of the sand layers, and it seems possible
that the irregular thickness and the strange contortions of the strata of the
sandstone at Petra may be due to some such cause. A curious observation of
Professor Forchhammer suggests an explanation of another peculiarity in
the structure of the sandstone of Mount Seir. He describes dunes in Jutland,
composed of yellow quartzose sand intermixed with black titanian iron.
When the wind blows over the surface of the dunes, it furrows the sand with
alternate ridges and depressions, ripples, in short, like those of water. The
swells, the dividing ridges of the system of sand ripples, are composed of
the light grains of quartz, while the heavier iron rolls into the depressions
between, and thus the whole surface of the dune appears as if covered with
a fine black network.
The sea side of dunes, being more exposed to the caprices of the wind, is
more irregular in form than the lee or land side, where the arrangement of
the particles is affected by fewer disturbing and conflicting influences.
Hence, the stratification of the windward slope is somewhat confused,
while the sand on the lee side is found to be disposed in more regular beds,
inclining landwards, and with the largest particles lowest, where their
greater weight would naturally carry them. The lee side of the dunes, being
thus formed of sand deposited according to the laws of gravity, is very
uniform in its slope, which, according to Forchhammer, varies little from an
angle of 30 degrees with the horizon, while the more exposed and irregular
weather side lies at an inclination of from 5 degrees to 10 degrees. When,
however, the outer tier of dunes is formed so near the waterline as to be
exposed to the immediate action of the waves, it is undermined, and the
face of the hill is very steep and sometimes nearly perpendicular.
Geological Importance of Dunes.
Page 707
These observations, and other facts which a more attentive study on the
spot would detect, might furnish the means of determining interesting and
important questions concerning geological formations in localities very
unlike those where dunes are now thrown up. For example, Studer supposes
that the drifting sand-hills of the African desert were originally coast dunes,
and that they have been transported to their present position far in the
interior, by the rolling and shifting leeward movement to which all dunes
not covered with vegetation are subject. The present general drift of the
sands of that desert appears to be to the south-west and west, the prevailing
winds blowing from the north-east and east; but it has been doubted
whether the shoals of the western coast of Northern Africa, and the sands
upon that shore, are derived from the bottom of the Atlantic, in the usual
manner, or, by an inverse process, from those of the Sahara. The latter, as
has been before remarked, is probably the truth, though observations are
wanting to decide the question. [Footnote: "The North African desert falls
into two divisions: the Sahel, or western, and the Sahar, or eastern. The
sands of the Sahar were, at a remote period, drifted to the west. In the Sahel,
the prevailing east winds drive the sand-ocean with a progressive westward
motion. The eastern half of the desert is swept clean."—Naumann,
Geognosie, ii., p. 1173.] There would be nothing violently improbable in
the a priori supposition that they may have been in part first thrown up by
the Mediterranean on its Libyan coast, and thence blown south and west
over the vast space they now cover. But inasmuch as it is now geologically
certain that the Sahara is an uplifted bed of an ancient sea, we may suppose
that, while submerged, it was, like other sea-bottoms, strewn with sand, and
that its present supply of that material was, in great proportion, brought up
with it. Laurent observed, some years ago, that marine shells of still extinct
species were found in the Sahara, far from the sea, and even at considerable
depths below the surface. [Footnote: Memoires sur le Sahara Oriental p. 62]
These observations have been confirmed past all question by Desor,
spot would detect, might furnish the means of determining interesting and
important questions concerning geological formations in localities very
unlike those where dunes are now thrown up. For example, Studer supposes
that the drifting sand-hills of the African desert were originally coast dunes,
and that they have been transported to their present position far in the
interior, by the rolling and shifting leeward movement to which all dunes
not covered with vegetation are subject. The present general drift of the
sands of that desert appears to be to the south-west and west, the prevailing
winds blowing from the north-east and east; but it has been doubted
whether the shoals of the western coast of Northern Africa, and the sands
upon that shore, are derived from the bottom of the Atlantic, in the usual
manner, or, by an inverse process, from those of the Sahara. The latter, as
has been before remarked, is probably the truth, though observations are
wanting to decide the question. [Footnote: "The North African desert falls
into two divisions: the Sahel, or western, and the Sahar, or eastern. The
sands of the Sahar were, at a remote period, drifted to the west. In the Sahel,
the prevailing east winds drive the sand-ocean with a progressive westward
motion. The eastern half of the desert is swept clean."—Naumann,
Geognosie, ii., p. 1173.] There would be nothing violently improbable in
the a priori supposition that they may have been in part first thrown up by
the Mediterranean on its Libyan coast, and thence blown south and west
over the vast space they now cover. But inasmuch as it is now geologically
certain that the Sahara is an uplifted bed of an ancient sea, we may suppose
that, while submerged, it was, like other sea-bottoms, strewn with sand, and
that its present supply of that material was, in great proportion, brought up
with it. Laurent observed, some years ago, that marine shells of still extinct
species were found in the Sahara, far from the sea, and even at considerable
depths below the surface. [Footnote: Memoires sur le Sahara Oriental p. 62]
These observations have been confirmed past all question by Desor,
Page 708
Martins, and others, and the facts and the obvious conclusion they suggest
are at present not disputed. But whatever has been the source and
movement of these sands, they can hardly fail to have left on their route
some sandstone monuments to mark their progress, such, for example, as
we have seen are formed from the dune sand at the mouth of the Nile; and it
is conceivable that the character of the drifting sands themselves, and of the
conglomerates and sandstones to whose formation they have contributed,
might furnish satisfactory evidence as to their origin, their starting-point,
and the course by which they have wandered so far from the sea. [Footnote:
Forchhammer, after pointing out the coincidence between the inclined
stratification of dunes and the structure of ancient tilted rocks, says: "But I
am not able to point out a sandstone formation corresponding to the dunes.
Probably most ancient dunes have been destroyed by submersion before the
loose sand became cemented to solid stone, but we may suppose that
circumstances have existed somewhere which have preserved the
characteristics of this formation."—Leonhard und Bronn, 1841, p. 8, 9.
Such formations, however, certainly exist. Laurent (Memoire sur le Sahara,
etc., p. 12) tells us that in the Algerian desert there are "sandstone
formation" not only "corresponding to the dunes," but, actually consolidated
within them. "A place called El-Mouia-Tadjer presents a repetition of what
we saw at El-Baya; one of the funnels formed in the middle of the dunes
contains wells from two metres to two and a half in depth, dug in a sand
which pressure, and probably the presence of certain salts, have cemented
so as to form true sandstone, soft indeed, but which does not yield except to
the pickaxe. These sandstones exhibit an inclination which seems to be the
effect of wind; for they conform to the direction of the sands which roll
down a scarp occasioned by the primitive obstacle."
"At New Quay the dune sands are converted to stone by an oxide of iron
held in solution by the water which pervades them. This stone, which is
formed, so to speak, under our eye, has been found solid enough to be
are at present not disputed. But whatever has been the source and
movement of these sands, they can hardly fail to have left on their route
some sandstone monuments to mark their progress, such, for example, as
we have seen are formed from the dune sand at the mouth of the Nile; and it
is conceivable that the character of the drifting sands themselves, and of the
conglomerates and sandstones to whose formation they have contributed,
might furnish satisfactory evidence as to their origin, their starting-point,
and the course by which they have wandered so far from the sea. [Footnote:
Forchhammer, after pointing out the coincidence between the inclined
stratification of dunes and the structure of ancient tilted rocks, says: "But I
am not able to point out a sandstone formation corresponding to the dunes.
Probably most ancient dunes have been destroyed by submersion before the
loose sand became cemented to solid stone, but we may suppose that
circumstances have existed somewhere which have preserved the
characteristics of this formation."—Leonhard und Bronn, 1841, p. 8, 9.
Such formations, however, certainly exist. Laurent (Memoire sur le Sahara,
etc., p. 12) tells us that in the Algerian desert there are "sandstone
formation" not only "corresponding to the dunes," but, actually consolidated
within them. "A place called El-Mouia-Tadjer presents a repetition of what
we saw at El-Baya; one of the funnels formed in the middle of the dunes
contains wells from two metres to two and a half in depth, dug in a sand
which pressure, and probably the presence of certain salts, have cemented
so as to form true sandstone, soft indeed, but which does not yield except to
the pickaxe. These sandstones exhibit an inclination which seems to be the
effect of wind; for they conform to the direction of the sands which roll
down a scarp occasioned by the primitive obstacle."
"At New Quay the dune sands are converted to stone by an oxide of iron
held in solution by the water which pervades them. This stone, which is
formed, so to speak, under our eye, has been found solid enough to be
Page 709
employed for building."-Esquiros, L'Angleterre, etc., in Revue des Deux
Mondes, 1864, pp. 44, 45.
The dunes near the mouth of the Nile, the lower sands of which have
been cemented together by the infiltration of Nile water, would probably
show a similar stratification in the sandstone which now forms their base.
Dana describes a laminated rook often formed by the infiltration of water
into the sand dunes on the Hawaian islands.—Corals and Coral Islands,
1872, p.155.]
If the sand of coast dunes is, as Staring describes it, composed chiefly of
well-rounded, quartzose grains, fragments of shells, and other constant
ingredients, it would often be recognizable as coast sand, in its agglutinate
state of sandstone. The texture of this rock varies from an almost
imperceptible fineness of grain to great coarseness, and affords good
facilities for microscopic observation of its structure. There are sandstones,
such, for example, as are used for grindstones, where the grit, as it is called,
is of exceeding sharpness; others where the angles of the grains are so
obtuse that they scarcely act at all on hard metals. The former may be
composed of grains of rock, disintegrated indeed, and re-cemented together,
but not, in the meanwhile, much rolled; the latter, of sands long washed by
the sea, and drifted by land-winds. There is, indeed, so much resemblance
between the effects of driving winds and of rolling water upon light bodies,
that there might be difficulty in distinguishing them; but after all, it is not
probable that sandstone, composed of grains thrown up from the salt sea,
and long tossed by the winds, would be identical in its structure with that
formed from fragments of rock crushed by mechanical force, or
disintegrated by heat, and again agglutinated without much exposure to the
action of moving water.
Mondes, 1864, pp. 44, 45.
The dunes near the mouth of the Nile, the lower sands of which have
been cemented together by the infiltration of Nile water, would probably
show a similar stratification in the sandstone which now forms their base.
Dana describes a laminated rook often formed by the infiltration of water
into the sand dunes on the Hawaian islands.—Corals and Coral Islands,
1872, p.155.]
If the sand of coast dunes is, as Staring describes it, composed chiefly of
well-rounded, quartzose grains, fragments of shells, and other constant
ingredients, it would often be recognizable as coast sand, in its agglutinate
state of sandstone. The texture of this rock varies from an almost
imperceptible fineness of grain to great coarseness, and affords good
facilities for microscopic observation of its structure. There are sandstones,
such, for example, as are used for grindstones, where the grit, as it is called,
is of exceeding sharpness; others where the angles of the grains are so
obtuse that they scarcely act at all on hard metals. The former may be
composed of grains of rock, disintegrated indeed, and re-cemented together,
but not, in the meanwhile, much rolled; the latter, of sands long washed by
the sea, and drifted by land-winds. There is, indeed, so much resemblance
between the effects of driving winds and of rolling water upon light bodies,
that there might be difficulty in distinguishing them; but after all, it is not
probable that sandstone, composed of grains thrown up from the salt sea,
and long tossed by the winds, would be identical in its structure with that
formed from fragments of rock crushed by mechanical force, or
disintegrated by heat, and again agglutinated without much exposure to the
action of moving water.
Page 710
Dunes of American Coasts.
Upon the Atlantic coast of the United States, the prevalence of western or
off-shore winds is unfavorable to the formation of dunes, and, though
marine currents lodge vast quantities of sand, in the form of banks, on that
coast, its shores are proportionally more free from sand-hills than some
others of lesser extent. There are, however, very important exceptions. The
action of the tide throws much sand upon some points of the New England
coast, as well as upon the Beaches of Long Island and other more southern
shores, and here dunes resembling those of Europe are formed. There are
also extensive ranges of dunes on the Pacific coast of the United States, and
at San Francisco they border some of the streets of the city.
The dunes of America are far older than her civilization, and the soil they
threaten or protect possesses, in general, too little value to justify any great
expenditure in measures for arresting their progress or preventing their
destruction. Hence, great as is their extent and their geographical
importance, they have, at present, no such intimate relations to human life
as to render them objects of special interest in the point of view I am taking,
and I do not know that the laws of their formation and motion have been
made a subject of original investigation by any American observer.
Dunes of Western Europe.
Upon the western coast of Europe, on the contrary, the ravages
occasioned by the movement of sand dunes, and the serious consequences
often resulting from the destruction of them, have long engaged the earnest
attention of Governments and of scientific men, and for nearly a century
persevering and systematic effort has been made to bring them under
human control. The subject has been carefully studied in Denmark and the
adjacent duchies, in Western Prussia, in the Netherlands, and in France; and
Upon the Atlantic coast of the United States, the prevalence of western or
off-shore winds is unfavorable to the formation of dunes, and, though
marine currents lodge vast quantities of sand, in the form of banks, on that
coast, its shores are proportionally more free from sand-hills than some
others of lesser extent. There are, however, very important exceptions. The
action of the tide throws much sand upon some points of the New England
coast, as well as upon the Beaches of Long Island and other more southern
shores, and here dunes resembling those of Europe are formed. There are
also extensive ranges of dunes on the Pacific coast of the United States, and
at San Francisco they border some of the streets of the city.
The dunes of America are far older than her civilization, and the soil they
threaten or protect possesses, in general, too little value to justify any great
expenditure in measures for arresting their progress or preventing their
destruction. Hence, great as is their extent and their geographical
importance, they have, at present, no such intimate relations to human life
as to render them objects of special interest in the point of view I am taking,
and I do not know that the laws of their formation and motion have been
made a subject of original investigation by any American observer.
Dunes of Western Europe.
Upon the western coast of Europe, on the contrary, the ravages
occasioned by the movement of sand dunes, and the serious consequences
often resulting from the destruction of them, have long engaged the earnest
attention of Governments and of scientific men, and for nearly a century
persevering and systematic effort has been made to bring them under
human control. The subject has been carefully studied in Denmark and the
adjacent duchies, in Western Prussia, in the Netherlands, and in France; and
Page 711
the experiments in the way of arresting the drifting of the dunes, and of
securing them, and the lands they shelter, from the encroachments of the
sea, have resulted in the adoption of a system of coast improvement
substantially the same in all these countries. The sands, like the forests,
have now their special literature, and the volumes and memoirs, which
describe them and the processes employed to subdue them, are full of
scientific interest and of practical instruction.
Dunes of Gascony.
In the small kingdom of Denmark, inclusive of the duchies of Schleswig
and Holstein, the dunes cover an area of more than two hundred and sixty
square miles. The breadth of the chain is very various, and in some places it
consists only of a single row of sand-hills, while in others, it is more than
six miles wide. [Footnote: Andersen, Om Klitformationen, pp. 78, 202,
275.] The dunes of the Prussian coast are vaguely estimated to cover from
eighty-five to one hundred and ten thousand acres; those of Holland one
hundred and forty thousand acres; and those of Gascony more than two
hundred thousand acres. I do not find any estimate of their extent in other
provinces of France, or in the Baltic provinces of Russia, but it is probable
that the entire quantity of dune land upon the Atlantic and Baltic shores of
Europe does not fall much short of a million of acres. [Footnote: In an
article on the dunes of Europe, in vol. 29 (1864) of Aus der Natur, p. 590,
the dunes are estimated to cover, on the islands and coasts of Schleswig
Holstein, in North-west Germany, Denmark, Holland, and France, one
hundred and eighty-one German, or nearly four thousand English square
miles; in Scotland, about ten German, or two hundred and ten English
miles; in Ireland, twenty German, or four hundred and twenty English
miles; and in England, one hundred and twenty German, or more than
twenty-five hundred English miles. Pannewitz (Anleitung zum Anbau der
securing them, and the lands they shelter, from the encroachments of the
sea, have resulted in the adoption of a system of coast improvement
substantially the same in all these countries. The sands, like the forests,
have now their special literature, and the volumes and memoirs, which
describe them and the processes employed to subdue them, are full of
scientific interest and of practical instruction.
Dunes of Gascony.
In the small kingdom of Denmark, inclusive of the duchies of Schleswig
and Holstein, the dunes cover an area of more than two hundred and sixty
square miles. The breadth of the chain is very various, and in some places it
consists only of a single row of sand-hills, while in others, it is more than
six miles wide. [Footnote: Andersen, Om Klitformationen, pp. 78, 202,
275.] The dunes of the Prussian coast are vaguely estimated to cover from
eighty-five to one hundred and ten thousand acres; those of Holland one
hundred and forty thousand acres; and those of Gascony more than two
hundred thousand acres. I do not find any estimate of their extent in other
provinces of France, or in the Baltic provinces of Russia, but it is probable
that the entire quantity of dune land upon the Atlantic and Baltic shores of
Europe does not fall much short of a million of acres. [Footnote: In an
article on the dunes of Europe, in vol. 29 (1864) of Aus der Natur, p. 590,
the dunes are estimated to cover, on the islands and coasts of Schleswig
Holstein, in North-west Germany, Denmark, Holland, and France, one
hundred and eighty-one German, or nearly four thousand English square
miles; in Scotland, about ten German, or two hundred and ten English
miles; in Ireland, twenty German, or four hundred and twenty English
miles; and in England, one hundred and twenty German, or more than
twenty-five hundred English miles. Pannewitz (Anleitung zum Anbau der
Page 712
Sandfluchen), as cited by Andresen (Om Klitformationen, p. 45), states that
the drifting sands of Europe, including, of course, sand plains as well as
dunes, cover an extent of 21,000 square miles. This is, perhaps, an
exaggeration, though there is, undoubtedly, much more desert-land of this
description on the European continent than has been generally supposed.
There is no question that most of this waste is capable of reclamation by
simple planting, and no mode of physical improvement is better worth the
attention of civilized Governments than this.
There are often serious objections to extensive forest planting on soils
capable of being otherwise made productive, but they do not apply to sand
wastes, which, until covered by woods, are not only a useless incumbrance,
but a source of serious danger to all human improvements in the
neighborhood of them.] This vast deposit of sea-sand extends along the
coasts for a distance of several hundred miles, and from the time of the
destruction of the forests which covered it, to the year 1789, the whole line
was rolling inwards and burying the soil beneath it, or rendering the fields
unproductive by the sand which drifted from it. At the same time, as the
sand-hills moved landwards, the ocean was closely following their retreat
and swallowing up the ground they had covered, as fast as their movement
left it bare.
Age, Character, and Permanence of Dunes.
The origin of most great lines of dunes goes back past all history. There
are on many coasts several distinct ranges of sand-hills which seem to be of
very different ages, and to have been formed under different relative
conditions of land and water. [Footnote: Krause, speaking of the dunes on
the coast of Prussia, says: "Their origin belongs to three different periods, in
which important changes in the relative level of sea and land have
unquestionably taken place…. Except in the deep depressions between
the drifting sands of Europe, including, of course, sand plains as well as
dunes, cover an extent of 21,000 square miles. This is, perhaps, an
exaggeration, though there is, undoubtedly, much more desert-land of this
description on the European continent than has been generally supposed.
There is no question that most of this waste is capable of reclamation by
simple planting, and no mode of physical improvement is better worth the
attention of civilized Governments than this.
There are often serious objections to extensive forest planting on soils
capable of being otherwise made productive, but they do not apply to sand
wastes, which, until covered by woods, are not only a useless incumbrance,
but a source of serious danger to all human improvements in the
neighborhood of them.] This vast deposit of sea-sand extends along the
coasts for a distance of several hundred miles, and from the time of the
destruction of the forests which covered it, to the year 1789, the whole line
was rolling inwards and burying the soil beneath it, or rendering the fields
unproductive by the sand which drifted from it. At the same time, as the
sand-hills moved landwards, the ocean was closely following their retreat
and swallowing up the ground they had covered, as fast as their movement
left it bare.
Age, Character, and Permanence of Dunes.
The origin of most great lines of dunes goes back past all history. There
are on many coasts several distinct ranges of sand-hills which seem to be of
very different ages, and to have been formed under different relative
conditions of land and water. [Footnote: Krause, speaking of the dunes on
the coast of Prussia, says: "Their origin belongs to three different periods, in
which important changes in the relative level of sea and land have
unquestionably taken place…. Except in the deep depressions between
Page 713
them, the dunes are everywhere sprinkled, to a considerable height, with
brown oxydulated iron, which has penetrated into the sand to the depth of
from three to eighteen inches, and colored it red. … Above the iron is a
stratum of sand differing in composition from ordinary sea-sand, and on
this, growing woods are always found…. The gradually accumulated forest
soil occurs in beds of from one to three feet thick, and changes, proceeding
upward, from gray sand to black humus."
Even on the third or seaward range, the sand grasses appear and thrive
luxuriantly, at least on the west coast, though Krause doubts whether the
dunes of the east coast were ever thus protected.—Der Dunenbau, pp. 8,
11.] In some cases there has been an upheaval of the coast line since the
formation of the oldest hillocks, and these have become inland dunes, while
younger rows have been thrown up on the new beach laid bare by elevation
of the sea-bed. Our knowledge of the mode of their first accumulation is
derived from observation of the action of wind and water in the few
instances where, with or without the aid of man, new coast dunes have been
accumulated, and of the influence of wind alone in elevating new sand-
heaps inland of the coast tier, when the outer rows are destroyed by the sea,
as also when the sodded surface of ancient sands has been broken, and the
subjacent strata laid open to the air.
It is a question of much interest, in what degree the naked condition of
most dunes is to be ascribed to the improvidence and indiscretion of man.
There are, in Western France, extensive ranges of dunes covered with
ancient and dense forests, while the recently formed sand-hills between
them and the sea are bare of vegetation, and in some cases are rapidly
advancing upon the wooded dunes, which they threaten to bury beneath
their drifts. Between the old dunes and the new there is no discoverable
difference in material or in structure; but the modern sand-hills are naked
and shifting, the ancient, clothed with vegetation and fixed. It has been
brown oxydulated iron, which has penetrated into the sand to the depth of
from three to eighteen inches, and colored it red. … Above the iron is a
stratum of sand differing in composition from ordinary sea-sand, and on
this, growing woods are always found…. The gradually accumulated forest
soil occurs in beds of from one to three feet thick, and changes, proceeding
upward, from gray sand to black humus."
Even on the third or seaward range, the sand grasses appear and thrive
luxuriantly, at least on the west coast, though Krause doubts whether the
dunes of the east coast were ever thus protected.—Der Dunenbau, pp. 8,
11.] In some cases there has been an upheaval of the coast line since the
formation of the oldest hillocks, and these have become inland dunes, while
younger rows have been thrown up on the new beach laid bare by elevation
of the sea-bed. Our knowledge of the mode of their first accumulation is
derived from observation of the action of wind and water in the few
instances where, with or without the aid of man, new coast dunes have been
accumulated, and of the influence of wind alone in elevating new sand-
heaps inland of the coast tier, when the outer rows are destroyed by the sea,
as also when the sodded surface of ancient sands has been broken, and the
subjacent strata laid open to the air.
It is a question of much interest, in what degree the naked condition of
most dunes is to be ascribed to the improvidence and indiscretion of man.
There are, in Western France, extensive ranges of dunes covered with
ancient and dense forests, while the recently formed sand-hills between
them and the sea are bare of vegetation, and in some cases are rapidly
advancing upon the wooded dunes, which they threaten to bury beneath
their drifts. Between the old dunes and the new there is no discoverable
difference in material or in structure; but the modern sand-hills are naked
and shifting, the ancient, clothed with vegetation and fixed. It has been
Page 714
conjectured that artificial methods of confinement and plantation were
employed by the primitive inhabitants of Gaul; and Laval, basing his
calculations on the rate of annual movement of the shifting dunes, assigns
the fifth century of the Christian era as the period when those processes
wore abandoned. [Footnote: Laval, Memoire sur les Dunes de Gascogne,
Annales des Ponts et Chaussees, 1847, 2me semestre, p. 231. The same
opinion had been expressed by Bremontier, Annales des Ponts et Chaussees,
1833, 1er semestre, p. 185.]
There is no historical evidence that the Gauls were acquainted with
artificial methods of fixing the sands of the coast, and we have little reason
to suppose that they were advanced enough in civilization to be likely to
resort to such processes, especially at a period when land could have had
but a moderate value.
In other countries, dunes have spontaneously clothed themselves with
forests, and the rapidity with which their surface is covered by various
species of sand-plants, and finally by trees, where man and cattle and
burrowing animals are excluded from them, renders it highly probable that
they would, as a general rule, protect themselves, if left to the undisturbed
action of natural causes. The sand-hills of the Frische Nehrung, on the coast
of Prussia, were formerly wooded down to the water's edge, and it was only
in the last century that, in consequence of the destruction of their forests,
they became moving sands. [Footnote: "In the Middle Ages," says Willibald
Alexis, as quoted by Muller, Das Buch der Pflanzenwelt, i., p. 16, "the
Nebrung was extending itself further, and the narrow opening near
Lochstadt had filled itself up with sand. A great pine forest bound with its
roots the dune sand and the heath uninterruptedly from Danzig to Pillau.
King Frederick William I. was once in want of money. A certain Herr von
Korff promised to procure it for him, without loan or taxes, if he could be
allowed to remove something quite useless. He thinned out the forests of
employed by the primitive inhabitants of Gaul; and Laval, basing his
calculations on the rate of annual movement of the shifting dunes, assigns
the fifth century of the Christian era as the period when those processes
wore abandoned. [Footnote: Laval, Memoire sur les Dunes de Gascogne,
Annales des Ponts et Chaussees, 1847, 2me semestre, p. 231. The same
opinion had been expressed by Bremontier, Annales des Ponts et Chaussees,
1833, 1er semestre, p. 185.]
There is no historical evidence that the Gauls were acquainted with
artificial methods of fixing the sands of the coast, and we have little reason
to suppose that they were advanced enough in civilization to be likely to
resort to such processes, especially at a period when land could have had
but a moderate value.
In other countries, dunes have spontaneously clothed themselves with
forests, and the rapidity with which their surface is covered by various
species of sand-plants, and finally by trees, where man and cattle and
burrowing animals are excluded from them, renders it highly probable that
they would, as a general rule, protect themselves, if left to the undisturbed
action of natural causes. The sand-hills of the Frische Nehrung, on the coast
of Prussia, were formerly wooded down to the water's edge, and it was only
in the last century that, in consequence of the destruction of their forests,
they became moving sands. [Footnote: "In the Middle Ages," says Willibald
Alexis, as quoted by Muller, Das Buch der Pflanzenwelt, i., p. 16, "the
Nebrung was extending itself further, and the narrow opening near
Lochstadt had filled itself up with sand. A great pine forest bound with its
roots the dune sand and the heath uninterruptedly from Danzig to Pillau.
King Frederick William I. was once in want of money. A certain Herr von
Korff promised to procure it for him, without loan or taxes, if he could be
allowed to remove something quite useless. He thinned out the forests of
Page 715
Prussia, which then, indeed, possessed little pecuniary value; but he felled
the entire woods of the Frische Nebrung, so far as they lay within the
Prussian territory. The financial operation was a success. The king had
money, but in the material effects which resulted from it, the state received
irreparable injury. The sea-winds rush over the bared hills; the Frische Haff
is half-choked with sand; the channel between Elbing, the sea, and
Konigsberg is endangered, and the fisheries in the Haff injured. The
operation of Herr von Korff brought the king 200,000 thalers. The state
would now willingly expend millions to restore the forests again."] There is
every reason to believe that the dunes of the Netherlands were clothed with
trees until after the Roman invasion. The old geographers, in describing
these countries, speak of vast forests extending to the very brink of the sea;
but drifting coast dunes are first mentioned by the chroniclers of the Middle
Ages, and so far as we know they have assumed a destructive character in
consequence of the improvidence of man. [Footnote: Staring, Voormaals en
Thans, p. 231. Had the dunes of the Netherlandish and French coasts, at the
period of the Roman invasion, resembled the moving sand-hills of the
present day, it is inconceivable that they could have escaped the notice of so
acute a physical geographer as Strabo; and the absolute silence of Caesar,
Ptolemy, and the encyclopaedic Pliny, respecting them, would be not less
inexplicable.] The history of the dunes of Michigan, so far as I have been
able to learn from my own observation, or that of others, is the same. Thirty
years ago, when that region was scarcely inhabited, they were generally
covered with a thick growth of trees, chiefly pines, and underwood, and
there was little appearance of undermining and wash on the lake side, or of
shifting of the sands, except where the trees had been cut or turned up by
the roots. [Footnote: The sands of Cape Cod were partially, if not
completely, covered with vegetation by nature. Dr. Dwight, describing the
dunes as they were in 1800, says: "Some of them are covered with beach
grass; some fringed with whortleberry bushes; and some tufted with a small
the entire woods of the Frische Nebrung, so far as they lay within the
Prussian territory. The financial operation was a success. The king had
money, but in the material effects which resulted from it, the state received
irreparable injury. The sea-winds rush over the bared hills; the Frische Haff
is half-choked with sand; the channel between Elbing, the sea, and
Konigsberg is endangered, and the fisheries in the Haff injured. The
operation of Herr von Korff brought the king 200,000 thalers. The state
would now willingly expend millions to restore the forests again."] There is
every reason to believe that the dunes of the Netherlands were clothed with
trees until after the Roman invasion. The old geographers, in describing
these countries, speak of vast forests extending to the very brink of the sea;
but drifting coast dunes are first mentioned by the chroniclers of the Middle
Ages, and so far as we know they have assumed a destructive character in
consequence of the improvidence of man. [Footnote: Staring, Voormaals en
Thans, p. 231. Had the dunes of the Netherlandish and French coasts, at the
period of the Roman invasion, resembled the moving sand-hills of the
present day, it is inconceivable that they could have escaped the notice of so
acute a physical geographer as Strabo; and the absolute silence of Caesar,
Ptolemy, and the encyclopaedic Pliny, respecting them, would be not less
inexplicable.] The history of the dunes of Michigan, so far as I have been
able to learn from my own observation, or that of others, is the same. Thirty
years ago, when that region was scarcely inhabited, they were generally
covered with a thick growth of trees, chiefly pines, and underwood, and
there was little appearance of undermining and wash on the lake side, or of
shifting of the sands, except where the trees had been cut or turned up by
the roots. [Footnote: The sands of Cape Cod were partially, if not
completely, covered with vegetation by nature. Dr. Dwight, describing the
dunes as they were in 1800, says: "Some of them are covered with beach
grass; some fringed with whortleberry bushes; and some tufted with a small
Page 716
and singular growth of oaks. … The parts of this barrier which are covered
with whortleberry bushes and with oaks, have been either not at all or very
little blown. The oaks, particularly, appear to be the continuation of the
forests originally formed on this spot. … They wore all the marks of
extreme age; were, in some instances, already decayed, and in others
decaying; were hoary with moss and were deformed by branches, broken
and wasted, not by violence, but by time."—Travels, iii., p. 91]
Nature, as she builds up dunes for the protection of the seashore,
provides, with similar conservatism, for the preservation of the dunes
themselves; so that, without the interference of man, these hillocks would
be, not perhaps absolutely perpetual, but very lasting in duration, and very
slowly altered in form or position. When once covered with the trees,
shrubs, and herbaceous growths adapted to such localities, dunes undergo
no apparent change, except the slow occasional undermining of the outer
tier, and accidental destruction by the exposure of the interior, from the
burrowing of animals, or the upturning of trees with their roots, and all
these causes of displacement are very much less destructive when a
vegetable covering exists in the immediate neighborhood of the breach.
Protection of Dunes.
Before the occupation of the coasts by man, dunes, at all points where
they have been observed, seem to have been protected in their rear by
forests, which served to break the force of the winds in both directions,
[Footnote: Bergsoe (Reventlovs Virksomhed, ii., 3) states that the dunes on
the west coast of Jutland were stationary before the destruction of the
forests to the east of them. The felling of the tall trees removed the
resistance to the lower currents of the westerly winds, and the sands have
since buried a great extent of fertile soil. See also same work, ii., p. 124.]
and to have spontaneously clothed themselves with a dense growth of the
with whortleberry bushes and with oaks, have been either not at all or very
little blown. The oaks, particularly, appear to be the continuation of the
forests originally formed on this spot. … They wore all the marks of
extreme age; were, in some instances, already decayed, and in others
decaying; were hoary with moss and were deformed by branches, broken
and wasted, not by violence, but by time."—Travels, iii., p. 91]
Nature, as she builds up dunes for the protection of the seashore,
provides, with similar conservatism, for the preservation of the dunes
themselves; so that, without the interference of man, these hillocks would
be, not perhaps absolutely perpetual, but very lasting in duration, and very
slowly altered in form or position. When once covered with the trees,
shrubs, and herbaceous growths adapted to such localities, dunes undergo
no apparent change, except the slow occasional undermining of the outer
tier, and accidental destruction by the exposure of the interior, from the
burrowing of animals, or the upturning of trees with their roots, and all
these causes of displacement are very much less destructive when a
vegetable covering exists in the immediate neighborhood of the breach.
Protection of Dunes.
Before the occupation of the coasts by man, dunes, at all points where
they have been observed, seem to have been protected in their rear by
forests, which served to break the force of the winds in both directions,
[Footnote: Bergsoe (Reventlovs Virksomhed, ii., 3) states that the dunes on
the west coast of Jutland were stationary before the destruction of the
forests to the east of them. The felling of the tall trees removed the
resistance to the lower currents of the westerly winds, and the sands have
since buried a great extent of fertile soil. See also same work, ii., p. 124.]
and to have spontaneously clothed themselves with a dense growth of the
Page 717
various plants, grasses, shrubs, and trees, which nature has assigned to such
soils. It is observed in Europe that dunes, though now without the shelter of
a forest country behind them, begin to protect themselves as soon as human
trespassers are excluded, and grazing animals denied access to them.
Herbaceous and arborescent plants spring up almost at once, first in the
depressions, and then upon the surface of the sand-hills. Every seed that
sprouts, binds together a certain amount of sand by its roots, shades a little
ground with its leaves, and furnishes food and shelter for still younger or
smaller growths. A succession of a very few favorable seasons suffices to
bind the whole surface together with a vegetable network, and the power of
resistance possessed by the dunes themselves, and the protection they afford
to the fields behind them, are just in proportion to the abundance and
density of the plants they support.
The growth of the vegetable covering can, of course, be much accelerated
by judicious planting and watchful care, and this species of improvement is
now carried on upon a vast scale on the sandy coasts of Western Europe,
wherever the value of land is considerable and the population dense.
Use of Dunes as a Barrier against the Sea.
Although the sea throws up large quantities of sand on flat lee-shores,
there are many cases where it continually encroaches on those same shores
and washes them away. At all points of the shallow North Sea where the
agitation of the waves extends to the bottom, banks are forming and rolling
eastwards. Hence the sea-sand tends to accumulate upon the coast of
Schleswig-Holstein and Jutland, and were there no conflicting influences,
the shore would rapidly extend itself westwards. But the same waves which
wash the sand to the coast undermine the beach they cover, and still more
rapidly degrade the shore at points where it is too high to receive partial
protection by the formation of dunes upon it. The earth of the coast is
soils. It is observed in Europe that dunes, though now without the shelter of
a forest country behind them, begin to protect themselves as soon as human
trespassers are excluded, and grazing animals denied access to them.
Herbaceous and arborescent plants spring up almost at once, first in the
depressions, and then upon the surface of the sand-hills. Every seed that
sprouts, binds together a certain amount of sand by its roots, shades a little
ground with its leaves, and furnishes food and shelter for still younger or
smaller growths. A succession of a very few favorable seasons suffices to
bind the whole surface together with a vegetable network, and the power of
resistance possessed by the dunes themselves, and the protection they afford
to the fields behind them, are just in proportion to the abundance and
density of the plants they support.
The growth of the vegetable covering can, of course, be much accelerated
by judicious planting and watchful care, and this species of improvement is
now carried on upon a vast scale on the sandy coasts of Western Europe,
wherever the value of land is considerable and the population dense.
Use of Dunes as a Barrier against the Sea.
Although the sea throws up large quantities of sand on flat lee-shores,
there are many cases where it continually encroaches on those same shores
and washes them away. At all points of the shallow North Sea where the
agitation of the waves extends to the bottom, banks are forming and rolling
eastwards. Hence the sea-sand tends to accumulate upon the coast of
Schleswig-Holstein and Jutland, and were there no conflicting influences,
the shore would rapidly extend itself westwards. But the same waves which
wash the sand to the coast undermine the beach they cover, and still more
rapidly degrade the shore at points where it is too high to receive partial
protection by the formation of dunes upon it. The earth of the coast is
Page 718
generally composed of particles finer, lighter, and more transportable by
water than the sea-sand. While, therefore, the billows raised by a heavy
west wind may roll up and deposit along the beach thousands of tons of
sand, the same waves may swallow up even a larger quantity of fine shore-
earth. This earth, with a portion of the sand, is swept off by northwardly and
southwardly currents, and let fall at other points of the coast, or carried off,
altogether, out of the reach of causes which might bring it back to its former
position.
Although, then, the eastern shore of the German Ocean here and there
advances into the sea, it in general retreats before it, and but for the
protection afforded it by natural arrangements seconded by the art and
industry of man, whole provinces would soon be engulfed by the waters.
This protection consists in an almost unbroken chain of sand banks and
dunes, extending from the northernmost point of Jutland to the Elbe, a
distance of not much less than three hundred miles, and from the Elbe
again, though with more frequent and wider interruptions, to the Atlantic
borders of France and Spain. So long as the dunes are maintained by nature
or by human art, they serve, like any other embankment or dike, as a partial
or a complete protection against the encroachments of the sea; and on the
other hand, when their drifts are not checked by natural processes, or by the
industry of man, they become a cause of as certain, if not of as sudden,
destruction as the ocean itself whose advance they retard. On the whole, the
dunes on the coast of the German Sea, notwithstanding the great quantity of
often fertile land they cover, and the evils which result from their
movement, are a protective and beneficial agent, and their maintenance is
an object of solicitude with the Governments and people of the shores they
defend. [Footnote: "We must, therefore, not be surprised to see the people
here deal as gingerly with their dunes as if treading among eggs. He who is
lucky enough to own a molehill of dune pets it affectionately, and spends
his substance in cherishing and fattening it. That fair, fertile, rich province,
water than the sea-sand. While, therefore, the billows raised by a heavy
west wind may roll up and deposit along the beach thousands of tons of
sand, the same waves may swallow up even a larger quantity of fine shore-
earth. This earth, with a portion of the sand, is swept off by northwardly and
southwardly currents, and let fall at other points of the coast, or carried off,
altogether, out of the reach of causes which might bring it back to its former
position.
Although, then, the eastern shore of the German Ocean here and there
advances into the sea, it in general retreats before it, and but for the
protection afforded it by natural arrangements seconded by the art and
industry of man, whole provinces would soon be engulfed by the waters.
This protection consists in an almost unbroken chain of sand banks and
dunes, extending from the northernmost point of Jutland to the Elbe, a
distance of not much less than three hundred miles, and from the Elbe
again, though with more frequent and wider interruptions, to the Atlantic
borders of France and Spain. So long as the dunes are maintained by nature
or by human art, they serve, like any other embankment or dike, as a partial
or a complete protection against the encroachments of the sea; and on the
other hand, when their drifts are not checked by natural processes, or by the
industry of man, they become a cause of as certain, if not of as sudden,
destruction as the ocean itself whose advance they retard. On the whole, the
dunes on the coast of the German Sea, notwithstanding the great quantity of
often fertile land they cover, and the evils which result from their
movement, are a protective and beneficial agent, and their maintenance is
an object of solicitude with the Governments and people of the shores they
defend. [Footnote: "We must, therefore, not be surprised to see the people
here deal as gingerly with their dunes as if treading among eggs. He who is
lucky enough to own a molehill of dune pets it affectionately, and spends
his substance in cherishing and fattening it. That fair, fertile, rich province,
Page 719
the peninsula of Eiderstadt in the south of Friesland, has, on the point
towards the sea, only a tiny row of dunes, some six miles long or so; but the
people talk of their fringe of sand hills, as if it were a border set with pearls.
They look upon it as their best defence against Neptune. They have
connected it with their system of dikes, and for years have kept sentries
posted to protect it against wanton injury."—J. G. Kohl, Die Inseln u.
Marschen Schleswig-Holsteins, ii., p. 115.]
The eastward progress of the sea on the Danish, Netherlandish, and
French coasts depends so much on local geological structure, on the force
and direction of tidal and other marine currents, on the volume and rapidity
of coast rivers, on the contingencies of the weather and on other varying
circumstances, that no general rate can be assigned to it.
At Agger, near the western end of the Liimfjord, in Jutland, the coast was
washed away, between the years 1815 and 1839, at the rate of more than
eighteen feet a year. The advance of the sea appears to have been something
less rapid for a century before; but from 1840 to 1857, it gained upon the
land no less than thirty feet a year. At other points of the shore of Jutland
the loss is smaller, but the sea is encroaching generally upon the whole line
of the coast. [Footnote: Andersen, "Om Klitformationen," pp. 68-72.]
The Liimfjord.
The irruption of the sea into the fresh-water lagoon of Liimfjord in
Jutland, in 1825—one of the most remarkable encroachments of the ocean
in modern times—is expressly ascribed to "mismanagement of the dunes"
on the narrow neck of land which separated the fjord from the North Sea. At
earlier periods the sea had swept across the isthmus, and even burst through
it, but the channel had been filled up again, sometimes by artificial means,
sometimes by the operation of natural causes, and on all these occasions
towards the sea, only a tiny row of dunes, some six miles long or so; but the
people talk of their fringe of sand hills, as if it were a border set with pearls.
They look upon it as their best defence against Neptune. They have
connected it with their system of dikes, and for years have kept sentries
posted to protect it against wanton injury."—J. G. Kohl, Die Inseln u.
Marschen Schleswig-Holsteins, ii., p. 115.]
The eastward progress of the sea on the Danish, Netherlandish, and
French coasts depends so much on local geological structure, on the force
and direction of tidal and other marine currents, on the volume and rapidity
of coast rivers, on the contingencies of the weather and on other varying
circumstances, that no general rate can be assigned to it.
At Agger, near the western end of the Liimfjord, in Jutland, the coast was
washed away, between the years 1815 and 1839, at the rate of more than
eighteen feet a year. The advance of the sea appears to have been something
less rapid for a century before; but from 1840 to 1857, it gained upon the
land no less than thirty feet a year. At other points of the shore of Jutland
the loss is smaller, but the sea is encroaching generally upon the whole line
of the coast. [Footnote: Andersen, "Om Klitformationen," pp. 68-72.]
The Liimfjord.
The irruption of the sea into the fresh-water lagoon of Liimfjord in
Jutland, in 1825—one of the most remarkable encroachments of the ocean
in modern times—is expressly ascribed to "mismanagement of the dunes"
on the narrow neck of land which separated the fjord from the North Sea. At
earlier periods the sea had swept across the isthmus, and even burst through
it, but the channel had been filled up again, sometimes by artificial means,
sometimes by the operation of natural causes, and on all these occasions
Page 720
effects were produced very similar to those resulting from the formation of
the new channel in 1825, which still remains open. [Footnote: Id., pp. 231,
232. Andresen's work, though printed in 1861, was finished in 1859. Lyell
(Antiquity of Man, 1863, p. 14) says: "Even in the course of the present
century, the salt-waters have made one eruption into the Baltic by the
Liimfjord, although they have been now again excluded."] Within
comparatively recent historical ages, the Liimfjord has thus been several
times alternately filled with fresh and with salt water, and man has
produced, by neglecting the dunes, or at least might have prevented by
maintaining them, changes identical with those which are usually ascribed
to the action of great geological causes, and sometimes supposed to have
required vast periods of time for their accomplishment.
"This breach," says Forchhammer, "which converted the Liimfjord into a
sound, and the northern part of Jutland into an island, occasioned
remarkable changes. The first and most striking phenomenon was the
sudden destruction of almost all the fresh-water fish previously inhabiting
this lagoon, which was famous for its abundant fisheries. Millions of fresh-
water fish were thrown on shore, partly dead and partly dying, and were
carted off by the people. A few only survived, and still frequent the shores
at the mouth of the brooks. The eel, however, has gradually accommodated
itself to the change of circumstances, and is found in all parts of the fjord,
while to all other fresh-water fish, the salt-water of the ocean seems to have
been fatal. It is more than probable that the sand washed in by the irruption
covers, in many places, a layer of dead fish, and has thus prepared the way
for a petrified stratum similar to those observed in so many older
formations.
"As it seems to be a law of nature that animals whose life is suddenly
extinguished while yet in full vigor, are the most likely to be preserved by
petrification, we find here one of the conditions favorable to the formation
the new channel in 1825, which still remains open. [Footnote: Id., pp. 231,
232. Andresen's work, though printed in 1861, was finished in 1859. Lyell
(Antiquity of Man, 1863, p. 14) says: "Even in the course of the present
century, the salt-waters have made one eruption into the Baltic by the
Liimfjord, although they have been now again excluded."] Within
comparatively recent historical ages, the Liimfjord has thus been several
times alternately filled with fresh and with salt water, and man has
produced, by neglecting the dunes, or at least might have prevented by
maintaining them, changes identical with those which are usually ascribed
to the action of great geological causes, and sometimes supposed to have
required vast periods of time for their accomplishment.
"This breach," says Forchhammer, "which converted the Liimfjord into a
sound, and the northern part of Jutland into an island, occasioned
remarkable changes. The first and most striking phenomenon was the
sudden destruction of almost all the fresh-water fish previously inhabiting
this lagoon, which was famous for its abundant fisheries. Millions of fresh-
water fish were thrown on shore, partly dead and partly dying, and were
carted off by the people. A few only survived, and still frequent the shores
at the mouth of the brooks. The eel, however, has gradually accommodated
itself to the change of circumstances, and is found in all parts of the fjord,
while to all other fresh-water fish, the salt-water of the ocean seems to have
been fatal. It is more than probable that the sand washed in by the irruption
covers, in many places, a layer of dead fish, and has thus prepared the way
for a petrified stratum similar to those observed in so many older
formations.
"As it seems to be a law of nature that animals whose life is suddenly
extinguished while yet in full vigor, are the most likely to be preserved by
petrification, we find here one of the conditions favorable to the formation
Page 721
of such a petrified stratum. The bottom of the Liimfjord was covered with a
vigorous growth of aquatic plants, belonging both to fresh and to salt water,
especially Zostera marina. This vegetation totally disappeared after the
irruption, and, in some instances, was buried by the sand; and here again we
have a familiar phenomenon often observed in ancient strata—the
indication of a given formation by a particular vegetable species—and
when the strata deposited at the time of the breach shall be accessible by
upheaval, the period of eruption will be marked by a stratum of Zostera, and
probably by impressions of fresh-water fishes.
"It is very remarkable that the Zostera marina, a sea-plant, was destroyed
even where no sand was deposited. This was probably in consequence of
the sudden change from brackish to salt water … It is well established that
the Liimfjord communicated with the German Ocean at some former
period.
To that era belong the deep beds of oyster shells and Cardium edule,
which are still found at the bottom of the fjord. And now, after an interval of
centuries, during which the lagoon contained no salt-water shell fish, it
again produces great numbers of Mytilus edulis. Could we obtain a deep
section of the bottom, we should find beds of Ostrea edulis and Cardium
edule, then a layer of Zostera marina with fresh-water fish, and then a bed
of Mytilus edulis. If, in course of time, the new channel should be closed,
the brooks would fill the lagoon again with fresh water; fresh-water fish and
shell fish would reappear, and thus we should have a repeated alternation of
organic inhabitants of the sea and of the waters of the land.
"These events have been accompanied with but a comparatively
insignificant change of land surface, while the formations in the bed of this
inland sea have been totally revolutionized in character." [Footnote:
Forchhammer, Geognostiche Studien am Meeres-Ufer, Leonhard und
vigorous growth of aquatic plants, belonging both to fresh and to salt water,
especially Zostera marina. This vegetation totally disappeared after the
irruption, and, in some instances, was buried by the sand; and here again we
have a familiar phenomenon often observed in ancient strata—the
indication of a given formation by a particular vegetable species—and
when the strata deposited at the time of the breach shall be accessible by
upheaval, the period of eruption will be marked by a stratum of Zostera, and
probably by impressions of fresh-water fishes.
"It is very remarkable that the Zostera marina, a sea-plant, was destroyed
even where no sand was deposited. This was probably in consequence of
the sudden change from brackish to salt water … It is well established that
the Liimfjord communicated with the German Ocean at some former
period.
To that era belong the deep beds of oyster shells and Cardium edule,
which are still found at the bottom of the fjord. And now, after an interval of
centuries, during which the lagoon contained no salt-water shell fish, it
again produces great numbers of Mytilus edulis. Could we obtain a deep
section of the bottom, we should find beds of Ostrea edulis and Cardium
edule, then a layer of Zostera marina with fresh-water fish, and then a bed
of Mytilus edulis. If, in course of time, the new channel should be closed,
the brooks would fill the lagoon again with fresh water; fresh-water fish and
shell fish would reappear, and thus we should have a repeated alternation of
organic inhabitants of the sea and of the waters of the land.
"These events have been accompanied with but a comparatively
insignificant change of land surface, while the formations in the bed of this
inland sea have been totally revolutionized in character." [Footnote:
Forchhammer, Geognostiche Studien am Meeres-Ufer, Leonhard und
Page 722
Bronn, Jahrbuch, 1841, pp. 11, 13.] Coasts of Schleswig-Holstein, Holland,
and France. On the islands on the coast of Schleswig-Holstein, the advance
of the sea has been more unequivocal and more rapid. Near the beginning
of the last century, the dunes which had protected the western coast of the
island of Sylt began to roll to the east, and the sea followed closely as they
retired. In 1757, the church of Rantum, a village upon that island, was
obliged to be taken down in consequence of the advance of the sand-hills;
in 1791, these hills had passed beyond its site, the waves had swallowed up
its foundations, and the sea gained so rapidly, that, fifty years later, the spot
where they lay was seven hundred feet from the shore. [Footnote: Andresen,
Om Klitformationen, pp. 68, 72.] The most prominent geological landmark
on the coast of Holland is the Huis te Britten, Arx Britannica, a fortress
built by the Romans, in the time of Caligula, on the main land near the
mouth of the Rhine. At the close of the seventeenth century, the sea had
advanced sixteen hundred paces beyond it. The older Dutch annalists
record, with much parade of numerical accuracy, frequent encroachments of
the sea upon many parts of the Netherlandish coast. But though the general
fact of an advance of the ocean upon the land is established beyond dispute,
the precision of the measurements which have been given is open to
question. Staring, however, who thinks the erosion of the coast much
exaggerated by popular geographers, admits a loss of more than a million
and a half acres, chiefly worthless morass; [Footnote: Voormaals en Thans,
pp. 126, 170.] and it is certain that but for the resistance of man, but for his
erection of dikes and protection of dunes, there would now be left of
Holland little but the name. It is, as has been already seen, still a debated
question among geologists whether the coast of Holland now is, and for
centuries has been, subsiding. I believe most investigators maintain the
affirmative; and if the fact is so, the advance of the sea upon the land is, in
part, due to this cause. But the rate of subsidence is at all events very small,
and therefore the encroachments of the ocean upon the coast are mainly to
and France. On the islands on the coast of Schleswig-Holstein, the advance
of the sea has been more unequivocal and more rapid. Near the beginning
of the last century, the dunes which had protected the western coast of the
island of Sylt began to roll to the east, and the sea followed closely as they
retired. In 1757, the church of Rantum, a village upon that island, was
obliged to be taken down in consequence of the advance of the sand-hills;
in 1791, these hills had passed beyond its site, the waves had swallowed up
its foundations, and the sea gained so rapidly, that, fifty years later, the spot
where they lay was seven hundred feet from the shore. [Footnote: Andresen,
Om Klitformationen, pp. 68, 72.] The most prominent geological landmark
on the coast of Holland is the Huis te Britten, Arx Britannica, a fortress
built by the Romans, in the time of Caligula, on the main land near the
mouth of the Rhine. At the close of the seventeenth century, the sea had
advanced sixteen hundred paces beyond it. The older Dutch annalists
record, with much parade of numerical accuracy, frequent encroachments of
the sea upon many parts of the Netherlandish coast. But though the general
fact of an advance of the ocean upon the land is established beyond dispute,
the precision of the measurements which have been given is open to
question. Staring, however, who thinks the erosion of the coast much
exaggerated by popular geographers, admits a loss of more than a million
and a half acres, chiefly worthless morass; [Footnote: Voormaals en Thans,
pp. 126, 170.] and it is certain that but for the resistance of man, but for his
erection of dikes and protection of dunes, there would now be left of
Holland little but the name. It is, as has been already seen, still a debated
question among geologists whether the coast of Holland now is, and for
centuries has been, subsiding. I believe most investigators maintain the
affirmative; and if the fact is so, the advance of the sea upon the land is, in
part, due to this cause. But the rate of subsidence is at all events very small,
and therefore the encroachments of the ocean upon the coast are mainly to
Page 723
be ascribed to the erosion and transportation of the soil by marine waves
and currents.
The sea is fast advancing at several points of the western coast of France,
and unknown causes have given a new impulse to its ravages since the
commencement of the present century. Between 1830 and 1842, the Point
de Grave, on the north side of the Girondo, retreated one hundred and
eighty metres, or fifty feet per year; from the latter year to 1846, the rate
was increased to more than three times that quantity, and the loss in those
four years was about six hundred feet. All the buildings at the extremity of
the peninsula have been taken down and rebuilt farther landwards, and the
lighthouse of the Grave now occupies its third position. The sea attacked
the base of the peninsula also, and the Point de Grave and the adjacent
coasts have been for thirty years the scene of one of the most obstinately
contested struggles between man and the ocean recorded in the annals of
modern engineering.
Movement of Dunes.
Besides their importance as a barrier against the inroads of the ocean,
dunes are useful by sheltering the cultivated ground behind them from the
violence of the sea-wind, from salt spray, and from the drifts of beach sand
which would otherwise overwhelm them. But the dunes themselves, unless
their surface sands are kept moist, and confined by the growth of plants, or
at least by a crust of vegetable earth, are constantly rolling inwards, and
thus, while, on one side, they lay bare the traces of ancient human
habitations or other evidences of the social life of primitive man, they are,
on the other, burying fields, houses, churches, and converting populous
districts into barren and deserted wastes.
and currents.
The sea is fast advancing at several points of the western coast of France,
and unknown causes have given a new impulse to its ravages since the
commencement of the present century. Between 1830 and 1842, the Point
de Grave, on the north side of the Girondo, retreated one hundred and
eighty metres, or fifty feet per year; from the latter year to 1846, the rate
was increased to more than three times that quantity, and the loss in those
four years was about six hundred feet. All the buildings at the extremity of
the peninsula have been taken down and rebuilt farther landwards, and the
lighthouse of the Grave now occupies its third position. The sea attacked
the base of the peninsula also, and the Point de Grave and the adjacent
coasts have been for thirty years the scene of one of the most obstinately
contested struggles between man and the ocean recorded in the annals of
modern engineering.
Movement of Dunes.
Besides their importance as a barrier against the inroads of the ocean,
dunes are useful by sheltering the cultivated ground behind them from the
violence of the sea-wind, from salt spray, and from the drifts of beach sand
which would otherwise overwhelm them. But the dunes themselves, unless
their surface sands are kept moist, and confined by the growth of plants, or
at least by a crust of vegetable earth, are constantly rolling inwards, and
thus, while, on one side, they lay bare the traces of ancient human
habitations or other evidences of the social life of primitive man, they are,
on the other, burying fields, houses, churches, and converting populous
districts into barren and deserted wastes.
Page 724
Especially destructive are they when, by any accident, a cavity is opened
into them to a considerable depth, thereby giving the wind access to the
interior, where the sand is thus first dried, and then scooped out and
scattered far over the neighboring soil. The dune is now a magazine of sand,
no longer a rampart against it, and mischief from this source seems more
difficult to resist than from almost any other drift, because the supply of
material at the command of the wind is more abundant and more
concentrated than in its original thin and widespread deposits on the beach.
The burrowing of conies in the dunes is, in this way, not unfreqnently a
cause of their destruction and of great injury to the fields behind them.
Drifts, and even inland sand-hills, sometimes result from breaking the
surface of more level sand deposits, far within the range of the coast dunes.
Thus we learn from Staring, that one of the highest inland dunes in
Friesland owes its origin to the opening of the drift sand by the uprooting of
a large Oak. [Footnote: De Bodem van Nederland, i. p. 425.]
Great as are the ravages produced by the encroachment of the sea upon
the western shores of continental Europe, they have been in some degree
compensated by spontaneous marine deposits at other points of the coast,
and we have seen in a former chapter that the industry of man has reclaimed
a large territory from the bosom of the ocean. These latter triumphs are not
of recent origin, and the incipient victories which paved the way for them
date back perhaps as far as ten centuries. In the meantime, the dunes had
been left to the operation of the laws of nature, or rather freed, by human
imprudence, from the fetters with which nature had bound them, and it is
scarcely three generations since man first attempted to check their
destructive movements. As they advanced, he unresistingly yielded and
retreated before them, and they have buried under their sandy billows many
hundreds of square miles of luxuriant cornfields and vineyards and forests.
into them to a considerable depth, thereby giving the wind access to the
interior, where the sand is thus first dried, and then scooped out and
scattered far over the neighboring soil. The dune is now a magazine of sand,
no longer a rampart against it, and mischief from this source seems more
difficult to resist than from almost any other drift, because the supply of
material at the command of the wind is more abundant and more
concentrated than in its original thin and widespread deposits on the beach.
The burrowing of conies in the dunes is, in this way, not unfreqnently a
cause of their destruction and of great injury to the fields behind them.
Drifts, and even inland sand-hills, sometimes result from breaking the
surface of more level sand deposits, far within the range of the coast dunes.
Thus we learn from Staring, that one of the highest inland dunes in
Friesland owes its origin to the opening of the drift sand by the uprooting of
a large Oak. [Footnote: De Bodem van Nederland, i. p. 425.]
Great as are the ravages produced by the encroachment of the sea upon
the western shores of continental Europe, they have been in some degree
compensated by spontaneous marine deposits at other points of the coast,
and we have seen in a former chapter that the industry of man has reclaimed
a large territory from the bosom of the ocean. These latter triumphs are not
of recent origin, and the incipient victories which paved the way for them
date back perhaps as far as ten centuries. In the meantime, the dunes had
been left to the operation of the laws of nature, or rather freed, by human
imprudence, from the fetters with which nature had bound them, and it is
scarcely three generations since man first attempted to check their
destructive movements. As they advanced, he unresistingly yielded and
retreated before them, and they have buried under their sandy billows many
hundreds of square miles of luxuriant cornfields and vineyards and forests.
Page 725
On the west coast of France a belt of dunes, varying in width from a
quarter of a mile to five miles, extends from the Adour to the estuary of the
Gironde, and covers an area of nine hundred and seventy square kilometres,
or two hundred and forty thousand acres. When not fixed by vegetable
growths, these dunes advance eastwards at a mean rate of about one rod, or
sixteen and a half feet, a year. Wo do not know historically when they began
to drift, but if we suppose their motion to have been always the same as at
present, they would have passed over the space between the sea coast and
their present eastern border, and covered the large area above mentioned, in
fourteen hundred years. We know, from written records, that they have
buried extensive fields and forests and thriving villages, and changed the
courses of rivers, and that the lighter particles carried from them by the
winds, even where not transported in sufficient quantities to form sand-hills,
have rendered sterile much land formerly fertile. [Footnote: The movement
of the dunes has been hardly less destructive on the north side of the
Gironde. See the valuable articles of Elisee Reclus in the Revue des Deux
Mondes for December 1862, and several later numbers, entitled "Le Littoral
de la France."] They have also injuriously obstructed the natural drainage of
the maritime districts by choking up the beds of the streams, and forming
lakes and pestilential swamps of no inconsiderable extent. In fact, so
completely do they embank the coast, that between the Gironde and the
village of Mimizan, a distance of one hundred miles, there are but two
outlets for the discharge of all the waters which flow from the land to the
sea; and the eastern front of the dunes is bordered by a succession of
stagnant pools, some of which are more than six miles in length and
breadth. [Footnote: Laval, Memoire sur les Dunes du Golfe de Gascongne,
Annales des Ponte et Chaussees, 1847, p. 223. The author adds, as a curious
and unexplained fact, that some of these pools, though evidently not
original formations but mere accumulations of water dammed up by the
dunes, have, along their western shore, near the base of the sand-hills, a
quarter of a mile to five miles, extends from the Adour to the estuary of the
Gironde, and covers an area of nine hundred and seventy square kilometres,
or two hundred and forty thousand acres. When not fixed by vegetable
growths, these dunes advance eastwards at a mean rate of about one rod, or
sixteen and a half feet, a year. Wo do not know historically when they began
to drift, but if we suppose their motion to have been always the same as at
present, they would have passed over the space between the sea coast and
their present eastern border, and covered the large area above mentioned, in
fourteen hundred years. We know, from written records, that they have
buried extensive fields and forests and thriving villages, and changed the
courses of rivers, and that the lighter particles carried from them by the
winds, even where not transported in sufficient quantities to form sand-hills,
have rendered sterile much land formerly fertile. [Footnote: The movement
of the dunes has been hardly less destructive on the north side of the
Gironde. See the valuable articles of Elisee Reclus in the Revue des Deux
Mondes for December 1862, and several later numbers, entitled "Le Littoral
de la France."] They have also injuriously obstructed the natural drainage of
the maritime districts by choking up the beds of the streams, and forming
lakes and pestilential swamps of no inconsiderable extent. In fact, so
completely do they embank the coast, that between the Gironde and the
village of Mimizan, a distance of one hundred miles, there are but two
outlets for the discharge of all the waters which flow from the land to the
sea; and the eastern front of the dunes is bordered by a succession of
stagnant pools, some of which are more than six miles in length and
breadth. [Footnote: Laval, Memoire sur les Dunes du Golfe de Gascongne,
Annales des Ponte et Chaussees, 1847, p. 223. The author adds, as a curious
and unexplained fact, that some of these pools, though evidently not
original formations but mere accumulations of water dammed up by the
dunes, have, along their western shore, near the base of the sand-hills, a
Page 726
depth of more than one hundred and thirty feet, and hence their bottoms are
not less than eighty feet below the level of the lowest tides. Their western
banks descend steeply, conforming nearly to the slope of the dunes, while
on the north-east and south the inclination of their beds is very gradual. The
greatest depth of these pools corresponds to that of the sea ten miles from
the shore. Is it possible that the weight of the sands has pressed together the
soil on which they rest, and thus occasioned a subsidence of the surface
extending beyond their base?
A more probable explanation of the fact stated in the note is suggested by
Elisee Reclus, in an article entitled Le Littoral de la France, in the Revue
des Deux Mondes for September 1, 1864, pp. 193, 194. This able writer
believes such pools to be the remains of ancient maritime bays, which have
been cut off from the ocean by gradually accumulated sand banks raised by
the waves and winds to the character of dunes.] A range of dunes extends
along the whole western coast of Jutland and Schleswig-Holstein, and the
movement of these sand-hills was formerly, and at some points still is, very
destructive. The rate of eastward movement of the drifting dunes varies
from three to twenty-four feet per annum. If we adopt the mean of thirteen
feet and a half for the annual motion, these dunes have traversed the widest
part of the belt in about twenty-five hundred years. Historical data are
wanting as to the period of the formation of these dunes and of the
commencement of their drifting; but there is recorded evidence that they
have buried a vast extent of valuable land within three or four centuries, and
further proof is found in the fact that the movement of the sands is
constantly uncovering ruins of ancient buildings, and other evidences of
human occupation, at points far within the present limits of the
uninhabitable desert. Andresen estimates the average depth of the sand
deposited over this area at thirty feet, which would give a cubic mile and a
half for the total quantity. [Footnote: Andresen, On Klitformationen, pp. 56,
79, 82]
not less than eighty feet below the level of the lowest tides. Their western
banks descend steeply, conforming nearly to the slope of the dunes, while
on the north-east and south the inclination of their beds is very gradual. The
greatest depth of these pools corresponds to that of the sea ten miles from
the shore. Is it possible that the weight of the sands has pressed together the
soil on which they rest, and thus occasioned a subsidence of the surface
extending beyond their base?
A more probable explanation of the fact stated in the note is suggested by
Elisee Reclus, in an article entitled Le Littoral de la France, in the Revue
des Deux Mondes for September 1, 1864, pp. 193, 194. This able writer
believes such pools to be the remains of ancient maritime bays, which have
been cut off from the ocean by gradually accumulated sand banks raised by
the waves and winds to the character of dunes.] A range of dunes extends
along the whole western coast of Jutland and Schleswig-Holstein, and the
movement of these sand-hills was formerly, and at some points still is, very
destructive. The rate of eastward movement of the drifting dunes varies
from three to twenty-four feet per annum. If we adopt the mean of thirteen
feet and a half for the annual motion, these dunes have traversed the widest
part of the belt in about twenty-five hundred years. Historical data are
wanting as to the period of the formation of these dunes and of the
commencement of their drifting; but there is recorded evidence that they
have buried a vast extent of valuable land within three or four centuries, and
further proof is found in the fact that the movement of the sands is
constantly uncovering ruins of ancient buildings, and other evidences of
human occupation, at points far within the present limits of the
uninhabitable desert. Andresen estimates the average depth of the sand
deposited over this area at thirty feet, which would give a cubic mile and a
half for the total quantity. [Footnote: Andresen, On Klitformationen, pp. 56,
79, 82]
Page 727
The drifting of the dunes on the coast of Prussia commenced not much
more than a hundred years ago. The Frische Nehrung is separated from the
mainland by the Frische Haff, and there is but a narrow strip of arable land
along its eastern borders. Hence its rolling sands have covered a
comparatively small extent of dry land, but fields and villages have been
buried and valuable forests laid waste by them. The loose coast-row has
drifted over the inland ranges, which, as was noticed in the description of
these dunes on a former page, were protected by a surface of different
composition, and the sand has thus been raised to a height which it could
not have reached upon level ground. This elevation has enabled it to
advance upon and overwhelm woods, which, upon a plain, would have
checked its progress, and, in one instance, a forest of many hundred acres of
tall pines was destroyed by the drifts between 1804 and 1827.
Control of Dunes by Man.
There are three principal modes in which the industry of man is brought
to bear upon the dunes. First, the creation of them, at points where, from
changes in the currents or other causes, new encroachments of the sea are
threatened; second, the maintenance and protection of them where they
have been naturally formed; and third, the removal of the inner rows where
the belt is so broad that no danger is to be apprehended from the loss of
them.
In describing the natural formation of dunes, it was said that they began
with an accumulation of sand around some vegetable or other accidental
obstruction to the drifting of the particles. A high, perpendicular cliff, which
deadens the wind altogether, prevents all accumulation of sand; but, up to a
certain point, the higher and broader the obstruction, the more sand will
heap up in front of it, and the more will that which falls behind it be
protected from drifting further. This familiar observation has taught the
more than a hundred years ago. The Frische Nehrung is separated from the
mainland by the Frische Haff, and there is but a narrow strip of arable land
along its eastern borders. Hence its rolling sands have covered a
comparatively small extent of dry land, but fields and villages have been
buried and valuable forests laid waste by them. The loose coast-row has
drifted over the inland ranges, which, as was noticed in the description of
these dunes on a former page, were protected by a surface of different
composition, and the sand has thus been raised to a height which it could
not have reached upon level ground. This elevation has enabled it to
advance upon and overwhelm woods, which, upon a plain, would have
checked its progress, and, in one instance, a forest of many hundred acres of
tall pines was destroyed by the drifts between 1804 and 1827.
Control of Dunes by Man.
There are three principal modes in which the industry of man is brought
to bear upon the dunes. First, the creation of them, at points where, from
changes in the currents or other causes, new encroachments of the sea are
threatened; second, the maintenance and protection of them where they
have been naturally formed; and third, the removal of the inner rows where
the belt is so broad that no danger is to be apprehended from the loss of
them.
In describing the natural formation of dunes, it was said that they began
with an accumulation of sand around some vegetable or other accidental
obstruction to the drifting of the particles. A high, perpendicular cliff, which
deadens the wind altogether, prevents all accumulation of sand; but, up to a
certain point, the higher and broader the obstruction, the more sand will
heap up in front of it, and the more will that which falls behind it be
protected from drifting further. This familiar observation has taught the
Page 728
inhabitants of the coast that an artificial wall or dike will, in many
situations, give rise to a broad belt of dunes. Thus a sand dike or wall, of
three or four miles in length, thrown in 1610 across the Koegras, a tide-
washed flat between the Zuiderzee and the North Sea, has occasioned the
formation of rows of dunes a mile in breadth, and thus excluded the sea
altogether from the Koegras. A similar dike, called the Zijperzeedijk, has
produced another scarcely less extensive belt in the course of two centuries.
A few years since, the sea was threatening to cut through the island of
Ameland, and, by encroachment on the southern side and the blowing off of
the sand from a low flat which connected the two higher parts of the island,
it had made such progress, that in heavy storms the waves sometimes rolled
quite across the isthmus. The construction of a breakwater and a sand dike
have already checked the advance of the sea, and a large number of sand-
hills has been formed, the rapid growth of which promises complete future
security against both wind and wave. Similar effects have been produced by
the erection of plank fences, and even of simple screens of wattling and
reeds. [Footnote: Staring, De Bodem van Nederland, i., pp. 329-331. Id.,
Voormaals en Thans, p. 163. Andresen, Om Klitformationen, pp. 280, 295.
The creation of new dunes, by the processes mentioned in the text, seems
to be much older in Europe than the adoption of measures for securing them
by planting. Dr. Dwight mentions a case in Massachusetts, where a beach
was restored, and new dunes formed, by planting beach grass. "Within the
memory of my informant, the sea broke over the beach which connects
Truro with Province Town, and swept the body of it away for some
distance. The beach grass was immediately planted on the spot; in
consequence of which the beach was again raised to a sufficient height, and
in various places into hills."—Travels, iii., p. 93.]
The dunes of Holland are sometimes protected from the dashing of the
waves by a revetement of stone, or by piles; and the lateral high-water
situations, give rise to a broad belt of dunes. Thus a sand dike or wall, of
three or four miles in length, thrown in 1610 across the Koegras, a tide-
washed flat between the Zuiderzee and the North Sea, has occasioned the
formation of rows of dunes a mile in breadth, and thus excluded the sea
altogether from the Koegras. A similar dike, called the Zijperzeedijk, has
produced another scarcely less extensive belt in the course of two centuries.
A few years since, the sea was threatening to cut through the island of
Ameland, and, by encroachment on the southern side and the blowing off of
the sand from a low flat which connected the two higher parts of the island,
it had made such progress, that in heavy storms the waves sometimes rolled
quite across the isthmus. The construction of a breakwater and a sand dike
have already checked the advance of the sea, and a large number of sand-
hills has been formed, the rapid growth of which promises complete future
security against both wind and wave. Similar effects have been produced by
the erection of plank fences, and even of simple screens of wattling and
reeds. [Footnote: Staring, De Bodem van Nederland, i., pp. 329-331. Id.,
Voormaals en Thans, p. 163. Andresen, Om Klitformationen, pp. 280, 295.
The creation of new dunes, by the processes mentioned in the text, seems
to be much older in Europe than the adoption of measures for securing them
by planting. Dr. Dwight mentions a case in Massachusetts, where a beach
was restored, and new dunes formed, by planting beach grass. "Within the
memory of my informant, the sea broke over the beach which connects
Truro with Province Town, and swept the body of it away for some
distance. The beach grass was immediately planted on the spot; in
consequence of which the beach was again raised to a sufficient height, and
in various places into hills."—Travels, iii., p. 93.]
The dunes of Holland are sometimes protected from the dashing of the
waves by a revetement of stone, or by piles; and the lateral high-water
Page 729
currents, which wash away their base, are occasionally checked by
transverse walls running from the foot of the dunes to low-water mark; but
the great expense of such constructions has prevented their adoption on a
large scale. [Footnote: Staring, i., pp. 310, 332.] The principal means relied
on for the protection of the sand-hills are the planting of their surfaces and
the exclusion of burrowing and grazing animals. There are grasses, creeping
plants, and shrubs of spontaneous growth, which flourish in loose sand, and,
if protected, spread over considerable tracts, and finally convert their face
into a soil capable of cultivation, or, at least, of producing forest trees.
Krause enumerates one hundred and seventy-one plants as native to the
coast sands of Prussia, and the observations of Andresen in Jutland carry the
number of these vegetables up to two hundred and thirty-four.
Some of these plants, especially the Arundo arenaria or arenosa, or
Psamma or Psammophila arenaria—Klittetag, or Hjelme in Danish, helm in
Dutch, Dunenhalm, Sandschilf, or Hugelrohr in German, gourbet in French,
and marram in English—are exclusively confined to sandy soils, and thrive
well only in a saline atmosphere. [Footnote: There is some confusion in the
popular use of these names, and in the scientific designations of sand-
plants, and they are possibly applied to different plants in different places.
Some writers style the gourbet Calamagrostis arenaria, and distinguish it
from the Danish Klittetag or Hjelme.] The arundo grows to the height of
about twenty-four inches, but sends its strong roots with their many rootlets
to a distance of forty or fifty feet. It has the peculiar property of flourishing
best in the loosest soil, and a sand-shower seems to refresh it as the rain
revives the thirsty plants of the common earth. Its roots bind together the
dunes, and its leaves protect their surface. When the sand ceases to drift, the
arundo dies, its decaying roots fertilizing the sand, and the decomposition
of its leaves forming a layer of vegetable earth over it. Then follows a
succession of other plants which gradually fit the sand-hills by growth and
transverse walls running from the foot of the dunes to low-water mark; but
the great expense of such constructions has prevented their adoption on a
large scale. [Footnote: Staring, i., pp. 310, 332.] The principal means relied
on for the protection of the sand-hills are the planting of their surfaces and
the exclusion of burrowing and grazing animals. There are grasses, creeping
plants, and shrubs of spontaneous growth, which flourish in loose sand, and,
if protected, spread over considerable tracts, and finally convert their face
into a soil capable of cultivation, or, at least, of producing forest trees.
Krause enumerates one hundred and seventy-one plants as native to the
coast sands of Prussia, and the observations of Andresen in Jutland carry the
number of these vegetables up to two hundred and thirty-four.
Some of these plants, especially the Arundo arenaria or arenosa, or
Psamma or Psammophila arenaria—Klittetag, or Hjelme in Danish, helm in
Dutch, Dunenhalm, Sandschilf, or Hugelrohr in German, gourbet in French,
and marram in English—are exclusively confined to sandy soils, and thrive
well only in a saline atmosphere. [Footnote: There is some confusion in the
popular use of these names, and in the scientific designations of sand-
plants, and they are possibly applied to different plants in different places.
Some writers style the gourbet Calamagrostis arenaria, and distinguish it
from the Danish Klittetag or Hjelme.] The arundo grows to the height of
about twenty-four inches, but sends its strong roots with their many rootlets
to a distance of forty or fifty feet. It has the peculiar property of flourishing
best in the loosest soil, and a sand-shower seems to refresh it as the rain
revives the thirsty plants of the common earth. Its roots bind together the
dunes, and its leaves protect their surface. When the sand ceases to drift, the
arundo dies, its decaying roots fertilizing the sand, and the decomposition
of its leaves forming a layer of vegetable earth over it. Then follows a
succession of other plants which gradually fit the sand-hills by growth and
Page 730
decay, for forest planting, for pasturage, and sometimes for ordinary
agricultural use.
But the protection and gradual transformation of the dunes is not the only
service rendered by this valuable plant. Its leaves are nutritious food for
sheep and cattle, its seeds for poultry; [Footnote: Bread, not indeed very
palatable, has been made of the seeds of the arundo, but the quantity which
can be gathered is not sufficient to form an important economical resource.
—Andresen, Om Klitformationen, p. 160.] cordage and netting twine are
manufactured from its fibres, it makes a good material for thatching, and its
dried roots furnish excellent fuel. These useful qualities, unfortunately, are
too often prejudicial to its growth. The peasants feed it down with their
cattle, cut it for rope-making, or dig if up for fuel, and it has been found
necessary to resort to severe legislation to prevent them from bringing ruin
upon themselves by thus improvidently sacrificing their most effectual
safeguard against the drifting of the sands. [Footnote: Bergsoe, Reventlovs
Virksomhed, ii., p. 4.]
In 1539 a decree of Christian III., king of Denmark, imposed a fine upon
persons convicted of destroying certain species of sand-plants upon the
west coast of Jutland. This ordinance was renewed and made more
comprehensive in 1558, and in 1569 the inhabitants of several districts were
required, by royal rescript, to do their best to check the sand-drifts, though
the specific measures to be adopted for that purpose are not indicated.
Various laws against stripping the dunes of their vegetation were enacted in
the following century, but no active measures were taken for the
subjugation of the sand-drifts until 1779, when a preliminary system of
operation for that purpose was adopted. This consisted in little more than
the planting of the Arundo arenaria, and other sand-plants, and the
exclusion of animals destructive to those vegetables. [Footnote: Measures
were taken for the protection of the dunes of Cape Cod, in Massachusetts,
agricultural use.
But the protection and gradual transformation of the dunes is not the only
service rendered by this valuable plant. Its leaves are nutritious food for
sheep and cattle, its seeds for poultry; [Footnote: Bread, not indeed very
palatable, has been made of the seeds of the arundo, but the quantity which
can be gathered is not sufficient to form an important economical resource.
—Andresen, Om Klitformationen, p. 160.] cordage and netting twine are
manufactured from its fibres, it makes a good material for thatching, and its
dried roots furnish excellent fuel. These useful qualities, unfortunately, are
too often prejudicial to its growth. The peasants feed it down with their
cattle, cut it for rope-making, or dig if up for fuel, and it has been found
necessary to resort to severe legislation to prevent them from bringing ruin
upon themselves by thus improvidently sacrificing their most effectual
safeguard against the drifting of the sands. [Footnote: Bergsoe, Reventlovs
Virksomhed, ii., p. 4.]
In 1539 a decree of Christian III., king of Denmark, imposed a fine upon
persons convicted of destroying certain species of sand-plants upon the
west coast of Jutland. This ordinance was renewed and made more
comprehensive in 1558, and in 1569 the inhabitants of several districts were
required, by royal rescript, to do their best to check the sand-drifts, though
the specific measures to be adopted for that purpose are not indicated.
Various laws against stripping the dunes of their vegetation were enacted in
the following century, but no active measures were taken for the
subjugation of the sand-drifts until 1779, when a preliminary system of
operation for that purpose was adopted. This consisted in little more than
the planting of the Arundo arenaria, and other sand-plants, and the
exclusion of animals destructive to those vegetables. [Footnote: Measures
were taken for the protection of the dunes of Cape Cod, in Massachusetts,
Page 731
during the colonial period, though I believe they are now substantially
abandoned. A hundred years ago, before the valley of the Mississippi, or
even the rich plains of Central and Western New York, were opened to the
white settler, the value of land was relatively much greater in New England
than it is at present, and consequently some rural improvements were then
worth making, which would not now yield sufficient returns to tempt the
investment of capital. The money and the time required to subdue and
render productive twenty acres of sea-sand on Cape Cod, would buy a
"section" and rear a family in Illinois. The son of the Pilgrim, therefore,
abandons the sea-hills, and seeks a better fortune on the fertile prairies of
the West. See Dwight, Travels, i., pp. 92, 93.] Ten years later, plantations of
forest trees, which have since proved so valuable a means of fixing the
dunes and rendering them productive, were commenced, and have been
continued ever since. [Footnote: Andresen, Om Klitformationen, pp. 237,
240.] During this latter period, Bremontier, without any knowledge of what
was doing in Denmark, experimented upon the cultivation of forest trees on
the dunes of Gascony, and perfected a system, which, with some
improvements in matters of detail, is still largely pursued on those shores.
The example of Denmark was soon followed in the neighboring kingdom
of Prussia, and in the Netherlands; and, as we shall see hereafter, these
improvements have been everywhere crowned with most flattering success.
Under the administration of Reventlov, a little before the close of the last
century, the Danish Government organized a regular system of
improvement in the economy of the dunes. They were planted with the
arundo and other vegetables of similar habits, protected against trespassers,
and at last partly covered with forest trees. By these means much waste soil
has been converted into arable ground, a large growth of valuable timber
obtained, and the further spread of the drifts, which threatened to lay waste
the whole peninsula of Jutland, to a considerable extent arrested.
abandoned. A hundred years ago, before the valley of the Mississippi, or
even the rich plains of Central and Western New York, were opened to the
white settler, the value of land was relatively much greater in New England
than it is at present, and consequently some rural improvements were then
worth making, which would not now yield sufficient returns to tempt the
investment of capital. The money and the time required to subdue and
render productive twenty acres of sea-sand on Cape Cod, would buy a
"section" and rear a family in Illinois. The son of the Pilgrim, therefore,
abandons the sea-hills, and seeks a better fortune on the fertile prairies of
the West. See Dwight, Travels, i., pp. 92, 93.] Ten years later, plantations of
forest trees, which have since proved so valuable a means of fixing the
dunes and rendering them productive, were commenced, and have been
continued ever since. [Footnote: Andresen, Om Klitformationen, pp. 237,
240.] During this latter period, Bremontier, without any knowledge of what
was doing in Denmark, experimented upon the cultivation of forest trees on
the dunes of Gascony, and perfected a system, which, with some
improvements in matters of detail, is still largely pursued on those shores.
The example of Denmark was soon followed in the neighboring kingdom
of Prussia, and in the Netherlands; and, as we shall see hereafter, these
improvements have been everywhere crowned with most flattering success.
Under the administration of Reventlov, a little before the close of the last
century, the Danish Government organized a regular system of
improvement in the economy of the dunes. They were planted with the
arundo and other vegetables of similar habits, protected against trespassers,
and at last partly covered with forest trees. By these means much waste soil
has been converted into arable ground, a large growth of valuable timber
obtained, and the further spread of the drifts, which threatened to lay waste
the whole peninsula of Jutland, to a considerable extent arrested.
Page 732
In France, the operations for fixing and reclaiming the dunes—which
began under the direction of Bremontier about the same time as in
Denmark, and which are, in principle and in many of their details, similar to
those employed in the latter kingdom—have been conducted on a far larger
scale, and with greater success, than in any other country. This is partly
owing to a climate more favorable to the growth of suitable forest trees than
that of Northern Europe, and partly to the liberality of the Government,
which, having more important landed interests to protect, has put larger
means at the disposal of the engineers than Denmark and Prussia have
found it convenient to appropriate to that purpose. The area of the dunes
already secured from drifting, and planted by the processes invented by
Bremontier and perfected by his successors, is about 100,000 acres.
[Footnote: "These plantations, perseveringly continued from the time of
Bremontier, now cover more than 40,000 hectares, and compose forests
which are not only the salvation of the department, but constitute its
wealth." —Clave, Etudes Forestieres, p. 254. Other authors have stated the
plantations of the French dunes to be much more extensive.] This amount of
productive soil, then, has been added to the resources of France, and a still
greater quantity of valuable land has been thereby rescued from the
otherwise certain destruction with which it was threatened by the advance
of the rolling sand-hills.
The improvements of the dunes on the coast of West Prussia began in
1795, under Soren Bjorn, a native of Denmark, and, with the exception of
the ten years between 1807 and 1817, they have been prosecuted ever since.
The methods do not differ essentially from those employed in Denmark and
France, though they are modified by local circumstances, and, with respect
to the trees selected for planting, by climate. In 1850, between the mouth of
the Vistula and Kahlberg, 6,300 acres, including about 1,900 acres planted
with pines and birches, had been secured from drifting; between Kahlberg
and the eastern boundary of West Prussia, 8,000 acres; and important
began under the direction of Bremontier about the same time as in
Denmark, and which are, in principle and in many of their details, similar to
those employed in the latter kingdom—have been conducted on a far larger
scale, and with greater success, than in any other country. This is partly
owing to a climate more favorable to the growth of suitable forest trees than
that of Northern Europe, and partly to the liberality of the Government,
which, having more important landed interests to protect, has put larger
means at the disposal of the engineers than Denmark and Prussia have
found it convenient to appropriate to that purpose. The area of the dunes
already secured from drifting, and planted by the processes invented by
Bremontier and perfected by his successors, is about 100,000 acres.
[Footnote: "These plantations, perseveringly continued from the time of
Bremontier, now cover more than 40,000 hectares, and compose forests
which are not only the salvation of the department, but constitute its
wealth." —Clave, Etudes Forestieres, p. 254. Other authors have stated the
plantations of the French dunes to be much more extensive.] This amount of
productive soil, then, has been added to the resources of France, and a still
greater quantity of valuable land has been thereby rescued from the
otherwise certain destruction with which it was threatened by the advance
of the rolling sand-hills.
The improvements of the dunes on the coast of West Prussia began in
1795, under Soren Bjorn, a native of Denmark, and, with the exception of
the ten years between 1807 and 1817, they have been prosecuted ever since.
The methods do not differ essentially from those employed in Denmark and
France, though they are modified by local circumstances, and, with respect
to the trees selected for planting, by climate. In 1850, between the mouth of
the Vistula and Kahlberg, 6,300 acres, including about 1,900 acres planted
with pines and birches, had been secured from drifting; between Kahlberg
and the eastern boundary of West Prussia, 8,000 acres; and important
Page 733
preliminary operations had been carried on for subduing the dunes on the
west coast. [Footnote: Kruse, Dunenbau, pp. 34, 38, 40.]
The tree which has been fonnd to thrive best upon the sand-hills of the
French coast, and at the same time to confine the sand most firmly and yield
the largest pecuniary returns, is the maritime pine, Pinus maritima, a species
valuable both for its timber and for its resinous products. It is always grown
from seed, and the young shoots require to be protected for several seasons,
by the branches of other trees, planted in rows, or spread over the surface
and staked down, by the growth of the Arundo arenaria and other small
sand-plants, or by wattled hedges. The beach, from which the sand is
derived, has been generally planted with the arundo, because the pine does
not thrive well so near the sea; but it is thought that a species of tamarisk is
likely to succeed in that latitude even better than the arundo. The shade and
the protection offered by the branching top of this pine are favorable to the
growth of deciduous trees, and, while still young, of shrubs and smaller
plants, which contribute more rapidly to the formation of vegetable mould,
and thus, when the pine has once taken root, the redemption of the waste is
considered as effectually secured.
In France, the maritime pine is planted on the sands of the interior as well
as on the dunes of the seacoast, and with equal advantage. This tree
resembles the pitch pine of the Southern American States in its habits, and
is applied to the same uses. The extraction of turpentine from it begins at
the age of about twenty years, or when it has attained a diameter of from
nine to twelve inches. Incisions are made up and down the trunk, to the
depth of about half an inch in the wood, and it is insisted that if not more
than two such slits are cut, the tree is not sensibly injured by the process.
The growth, indeed, is somewhat checked, but the wood becomes superior
to that of trees from which the turpentine is not extracted. Thus treated, the
pine continues to flourish to the age of one hundred or one hundred and
west coast. [Footnote: Kruse, Dunenbau, pp. 34, 38, 40.]
The tree which has been fonnd to thrive best upon the sand-hills of the
French coast, and at the same time to confine the sand most firmly and yield
the largest pecuniary returns, is the maritime pine, Pinus maritima, a species
valuable both for its timber and for its resinous products. It is always grown
from seed, and the young shoots require to be protected for several seasons,
by the branches of other trees, planted in rows, or spread over the surface
and staked down, by the growth of the Arundo arenaria and other small
sand-plants, or by wattled hedges. The beach, from which the sand is
derived, has been generally planted with the arundo, because the pine does
not thrive well so near the sea; but it is thought that a species of tamarisk is
likely to succeed in that latitude even better than the arundo. The shade and
the protection offered by the branching top of this pine are favorable to the
growth of deciduous trees, and, while still young, of shrubs and smaller
plants, which contribute more rapidly to the formation of vegetable mould,
and thus, when the pine has once taken root, the redemption of the waste is
considered as effectually secured.
In France, the maritime pine is planted on the sands of the interior as well
as on the dunes of the seacoast, and with equal advantage. This tree
resembles the pitch pine of the Southern American States in its habits, and
is applied to the same uses. The extraction of turpentine from it begins at
the age of about twenty years, or when it has attained a diameter of from
nine to twelve inches. Incisions are made up and down the trunk, to the
depth of about half an inch in the wood, and it is insisted that if not more
than two such slits are cut, the tree is not sensibly injured by the process.
The growth, indeed, is somewhat checked, but the wood becomes superior
to that of trees from which the turpentine is not extracted. Thus treated, the
pine continues to flourish to the age of one hundred or one hundred and
Page 734
twenty years, and up to this age the trees on an acre yield annually 300
pounds of essence of turpentine, and 250 pounds of resin, worth together
not far from ten dollars. The expense of extraction and distillation is
calculated at about four dollars, and a clear profit of more than five dollars
per acre is left. [Footnote: These processes are substantially similar to those
employed in the pineries of the Carolinas, but they are better systematized
and more economically conducted in France. In the latter country, all the
products of the pine, even to the cones, find a remunerating market, while,
in America, the price of resin is so low, that in the fierce steamboat races on
the great rivers, large quantities of it are thrown into the furnaces to increase
the intensity of the fires. In a carefully prepared article on the Southern
pineries published in an American magazine—I think Harper's—a few years
ago, it was stated that the resin from the turpentine distilleries was
sometimes allowed to run to waste; and the writer, in one instance, observed
a mass, thus rejected as rubbish, which was estimated to amount to two
thousand barrels. Olmsted saw, near a distillery which had been in operation
but a single year, a pool of resin estimated to contain three thousand barrels,
which had been allowed to run off as waste.—A Journey in the seaboard
Slave States, 1863, p. 345.] This is exclusive of the value of the timber,
when finally cut, which, of course, amounts to a very considerable sum. In
Denmark, where the climate is much colder, hardier conifers, as well as the
birch and other northern trees, are found to answer a better purpose than the
maritime pine, and it is doubtful whether this tree would be able to resist the
winter on the dunes of Massachusetts. Probably the pitch-pine of the
Northern States, in conjunction with some of the American oaks, birches,
and poplars, and especially the robinia or locust, would prove very suitable
to be employed on the sand-hills of Cape Cod and Long Island. The
ailanthus, now coming into notice as a sand-loving tree, some species of
tamarisk, and perhaps the Aspressus macrocarpa, already found useful on
the dunes in California, may prove valuable auxiliaries in resisting the
pounds of essence of turpentine, and 250 pounds of resin, worth together
not far from ten dollars. The expense of extraction and distillation is
calculated at about four dollars, and a clear profit of more than five dollars
per acre is left. [Footnote: These processes are substantially similar to those
employed in the pineries of the Carolinas, but they are better systematized
and more economically conducted in France. In the latter country, all the
products of the pine, even to the cones, find a remunerating market, while,
in America, the price of resin is so low, that in the fierce steamboat races on
the great rivers, large quantities of it are thrown into the furnaces to increase
the intensity of the fires. In a carefully prepared article on the Southern
pineries published in an American magazine—I think Harper's—a few years
ago, it was stated that the resin from the turpentine distilleries was
sometimes allowed to run to waste; and the writer, in one instance, observed
a mass, thus rejected as rubbish, which was estimated to amount to two
thousand barrels. Olmsted saw, near a distillery which had been in operation
but a single year, a pool of resin estimated to contain three thousand barrels,
which had been allowed to run off as waste.—A Journey in the seaboard
Slave States, 1863, p. 345.] This is exclusive of the value of the timber,
when finally cut, which, of course, amounts to a very considerable sum. In
Denmark, where the climate is much colder, hardier conifers, as well as the
birch and other northern trees, are found to answer a better purpose than the
maritime pine, and it is doubtful whether this tree would be able to resist the
winter on the dunes of Massachusetts. Probably the pitch-pine of the
Northern States, in conjunction with some of the American oaks, birches,
and poplars, and especially the robinia or locust, would prove very suitable
to be employed on the sand-hills of Cape Cod and Long Island. The
ailanthus, now coming into notice as a sand-loving tree, some species of
tamarisk, and perhaps the Aspressus macrocarpa, already found useful on
the dunes in California, may prove valuable auxiliaries in resisting the
Page 735
encroachment of drifting sands, whether in America or in Europe, and the
intermixing of different species would doubtless be attended with as
valuable results in this as in other branches of forest economy. It cannot,
indeed, be affirmed that human power is able to arrest altogether the
incursions of the waves on sandy coasts, by planting the beach, and clothing
the dunes with wood. On the contrary, both in Holland and on the French
coast, it has been found necessary to protect the dunes themselves by piling
and by piers and sea-walls of heavy masonry. But experience has amply
shown that the processes referred to are entirely successful in preventing the
movement of the dunes, and the drifting of their sands over cultivated lands
behind them; and that, at the same time, the plantations very much retard
the landward progress of the waters. [Footnote: See a very interesting
article entitled "Le Littoral de la France," by Elisee Reclus, in the Revue
des Deux Mondes for December, 1862, pp. 901, 936.]
Besides the special office of dune plantations already noticed, these
forests have the same general uses as other woods, and they have
sometimes formed by their droppings so thick a layer of vegetable mould
that the sand beneath has become sufficiently secured to allow the wood to
be felled, and the surface to be ploughed and cultivated with ordinary field
crops.
In some cases it has been found possible to confine and cultivate coast
sand-hills, even without preliminary forestal plantation. Thus, in the vicinity
of Cap Breton in France, a peculiar process is successfully employed, both
for preventing the drifting of dunes, and for rendering the sands themselves
immediately productive; but this method is applicable only in exceptional
cases of favorable climate and exposure. It consists in planting vineyards
upon the dunes, and protecting them by hedges of broom, Erica scoparia, so
disposed as to form rectangles about thirty feet by forty. The vines planted
in these enclosures thrive admirably, and the grapes produced by them are
intermixing of different species would doubtless be attended with as
valuable results in this as in other branches of forest economy. It cannot,
indeed, be affirmed that human power is able to arrest altogether the
incursions of the waves on sandy coasts, by planting the beach, and clothing
the dunes with wood. On the contrary, both in Holland and on the French
coast, it has been found necessary to protect the dunes themselves by piling
and by piers and sea-walls of heavy masonry. But experience has amply
shown that the processes referred to are entirely successful in preventing the
movement of the dunes, and the drifting of their sands over cultivated lands
behind them; and that, at the same time, the plantations very much retard
the landward progress of the waters. [Footnote: See a very interesting
article entitled "Le Littoral de la France," by Elisee Reclus, in the Revue
des Deux Mondes for December, 1862, pp. 901, 936.]
Besides the special office of dune plantations already noticed, these
forests have the same general uses as other woods, and they have
sometimes formed by their droppings so thick a layer of vegetable mould
that the sand beneath has become sufficiently secured to allow the wood to
be felled, and the surface to be ploughed and cultivated with ordinary field
crops.
In some cases it has been found possible to confine and cultivate coast
sand-hills, even without preliminary forestal plantation. Thus, in the vicinity
of Cap Breton in France, a peculiar process is successfully employed, both
for preventing the drifting of dunes, and for rendering the sands themselves
immediately productive; but this method is applicable only in exceptional
cases of favorable climate and exposure. It consists in planting vineyards
upon the dunes, and protecting them by hedges of broom, Erica scoparia, so
disposed as to form rectangles about thirty feet by forty. The vines planted
in these enclosures thrive admirably, and the grapes produced by them are
Page 736
among the best grown in France. The dunes are so far from being an
unfavorable soil for the vine, that fresh sea-sand is regularly employed as a
fertilizer for it, alternating every other season with ordinary manure. The
quantity of sand thus applied every second year, raises the surface of the
vineyard about four or five inches. The vines are cut down every year to
three or four shoots, and the raising of the soil rapidly covers the old stocks.
As fast as buried, they send out new roots near the surface, and thus the
vineyard is constantly renewed, and has always a youthful appearance,
though it may have been already planted a couple of generations. This
practice is ascertained to have been followed for two centuries, and is
among the oldest well-authenticated attempts of man to resist and vanquish
the dunes. [Footnote: Boitel, Mise en valeur des Terres pauvres, pp. 212,
218.]
The artificial removal of dunes, no longer necessary as a protection, does
not appear to have been practiced upon a large scale except in the
Netherlands, where the numerous canals furnish an easy and economical
means of transporting the sand, and where the construction and
maintenance of sea and river dikes, and of causeways and other
embankments and fillings, create a great demand for that material. Sand is
also employed in Holland, in large quantities, for improving the consistence
of the tough clay bordering upon or underlying diluvial deposits, and for
forming an artificial soil for the growth of certain garden and ornamental
vegetables. When the dunes are removed, the ground they covered is
restored to the domain of industry; and the quantity of land recovered in the
Netherlands by the removal of the barren sands which encumbered it,
amounts to hundreds and perhaps thousands of acres.
Inland Dunes.
unfavorable soil for the vine, that fresh sea-sand is regularly employed as a
fertilizer for it, alternating every other season with ordinary manure. The
quantity of sand thus applied every second year, raises the surface of the
vineyard about four or five inches. The vines are cut down every year to
three or four shoots, and the raising of the soil rapidly covers the old stocks.
As fast as buried, they send out new roots near the surface, and thus the
vineyard is constantly renewed, and has always a youthful appearance,
though it may have been already planted a couple of generations. This
practice is ascertained to have been followed for two centuries, and is
among the oldest well-authenticated attempts of man to resist and vanquish
the dunes. [Footnote: Boitel, Mise en valeur des Terres pauvres, pp. 212,
218.]
The artificial removal of dunes, no longer necessary as a protection, does
not appear to have been practiced upon a large scale except in the
Netherlands, where the numerous canals furnish an easy and economical
means of transporting the sand, and where the construction and
maintenance of sea and river dikes, and of causeways and other
embankments and fillings, create a great demand for that material. Sand is
also employed in Holland, in large quantities, for improving the consistence
of the tough clay bordering upon or underlying diluvial deposits, and for
forming an artificial soil for the growth of certain garden and ornamental
vegetables. When the dunes are removed, the ground they covered is
restored to the domain of industry; and the quantity of land recovered in the
Netherlands by the removal of the barren sands which encumbered it,
amounts to hundreds and perhaps thousands of acres.
Inland Dunes.
Page 737
Vast deposits of sand, both in the form of dunes and of plains, are found
far in the interior of continents, in the Old World and in the New. The
deserts of Gobi, of Arabia, and of Africa have been rendered familiar by the
narratives of travellers, but the sandy wilderness of America, and even of
Europe, have not yet been generally recognized as important elements in
the geography of the regions where they occur. There are immense wastes
of drifting sands in Poland and other interior parts of Europe, in Peru, and
in the less known regions of our own Western territory, where their extent is
greater than that of all the coast dunes together which have hitherto been
described by European and American geographers. [Footnote: On the
Niobrara river alone, the dunes cover a surface of twenty thousand square
miles.—Hayden, Report on Geological Survey of Wyoming, 1870, p. 108.]
The inland sand-hills of both hemispheres are composed of substantially the
same material and aggregated by the action of the same natural forces as the
dunes of the coast. There is, therefore, a general resemblance between them,
but they appear, nevertheless, to be distinguished by certain differences
which a more attentive study may perhaps enable geologists to recognize in
the sandstone formed by them. The sand of which they are composed comes
in both principally from the bed of the sea being brought to the surface in
one case by the action of the wind and the waves, in the other by geological
upheaval. [Footnote: American observers do not agree in their descriptions
of the form and character of the sand-grains which compose the interior
dunes of the North American desert. C. C. Parry, geologist to the Mexican
Boundary Commission, in describing the dunes near the station at a spring
thirty-two miles west from the Rio Grande at El Paso, says: "The separate
grains of the sand composing the sand-hills are seen under a lens to be
angular, and not rounded, as would be the case in regular beach
deposits."—U. S. Mexican Boundary Survey, Report of, vol i., Geological
Report of C. C. Parry, p. 10.
far in the interior of continents, in the Old World and in the New. The
deserts of Gobi, of Arabia, and of Africa have been rendered familiar by the
narratives of travellers, but the sandy wilderness of America, and even of
Europe, have not yet been generally recognized as important elements in
the geography of the regions where they occur. There are immense wastes
of drifting sands in Poland and other interior parts of Europe, in Peru, and
in the less known regions of our own Western territory, where their extent is
greater than that of all the coast dunes together which have hitherto been
described by European and American geographers. [Footnote: On the
Niobrara river alone, the dunes cover a surface of twenty thousand square
miles.—Hayden, Report on Geological Survey of Wyoming, 1870, p. 108.]
The inland sand-hills of both hemispheres are composed of substantially the
same material and aggregated by the action of the same natural forces as the
dunes of the coast. There is, therefore, a general resemblance between them,
but they appear, nevertheless, to be distinguished by certain differences
which a more attentive study may perhaps enable geologists to recognize in
the sandstone formed by them. The sand of which they are composed comes
in both principally from the bed of the sea being brought to the surface in
one case by the action of the wind and the waves, in the other by geological
upheaval. [Footnote: American observers do not agree in their descriptions
of the form and character of the sand-grains which compose the interior
dunes of the North American desert. C. C. Parry, geologist to the Mexican
Boundary Commission, in describing the dunes near the station at a spring
thirty-two miles west from the Rio Grande at El Paso, says: "The separate
grains of the sand composing the sand-hills are seen under a lens to be
angular, and not rounded, as would be the case in regular beach
deposits."—U. S. Mexican Boundary Survey, Report of, vol i., Geological
Report of C. C. Parry, p. 10.
Page 738
In the general description of the country traversed, same volume, p. 47,
Colonel Emory says that on an "examination of the sand with a microscope
of sufficient power," the grains are seen to be angular, not rounded by
rolling in water.
On the other hand, Blake, in Geological Report, Pacific Railroad Rep.,
vol. v., p. 119, observes that the grains of the dune sand, consisting of
quartz, chalcedony, carnelian, agate, rose quartz, and probably chrysolite,
were much rounded; and on page 241, he says that many of the sand grains
of the Colorado desert are perfect spheres. On page 20 of a report in vol. ii.
of the Pacific Railroad Report, by the same observer, it is said that an
examination of dunes brought from the Llano Estacado by Captain Pope,
showed the grains to be "much rounded by attrition." The sands described
by Mr. Parry and Colonel Emory are not from the same localities as those
examined by Mr. Blake, and the difference in their character may be due to
a difference of origin or of age. In New Mexico, sixty miles south of Fort
Stanton, there are island dunes composed of finely granulated gypsum.—
American Naturalist, Jan. 1871, p. 695.] The sand of the coast dunes is
rendered, to a certain extent, cohesive by moisture and by the saline and
other binding ingredients of sea-water, while long exposure to meteoric
influences has in a great measure deprived the inland sands of these
constituents, though there are not wanting examples of large accumulations
of sand far from the sea, and yet agglutinated by saline material. Hence, as
might be expected, inland dunes, when not confined by a fixed nucleus, are
generally more movable than those of the coast, and the form of such dunes
is more or less modified by their want of consistence. Thus, the crescent or
falciform shape is described by all observers as more constant and
conspicuous in these sandhills than in those of littoral origin; they tend less
to unite in continuous ridges, and they rarely attain the height or other
dimensions of the dunes of the seashore. Meyer describes the sand-hills of
the Peruvian desert as perfectly falciform in shape and from seven to fifteen
Colonel Emory says that on an "examination of the sand with a microscope
of sufficient power," the grains are seen to be angular, not rounded by
rolling in water.
On the other hand, Blake, in Geological Report, Pacific Railroad Rep.,
vol. v., p. 119, observes that the grains of the dune sand, consisting of
quartz, chalcedony, carnelian, agate, rose quartz, and probably chrysolite,
were much rounded; and on page 241, he says that many of the sand grains
of the Colorado desert are perfect spheres. On page 20 of a report in vol. ii.
of the Pacific Railroad Report, by the same observer, it is said that an
examination of dunes brought from the Llano Estacado by Captain Pope,
showed the grains to be "much rounded by attrition." The sands described
by Mr. Parry and Colonel Emory are not from the same localities as those
examined by Mr. Blake, and the difference in their character may be due to
a difference of origin or of age. In New Mexico, sixty miles south of Fort
Stanton, there are island dunes composed of finely granulated gypsum.—
American Naturalist, Jan. 1871, p. 695.] The sand of the coast dunes is
rendered, to a certain extent, cohesive by moisture and by the saline and
other binding ingredients of sea-water, while long exposure to meteoric
influences has in a great measure deprived the inland sands of these
constituents, though there are not wanting examples of large accumulations
of sand far from the sea, and yet agglutinated by saline material. Hence, as
might be expected, inland dunes, when not confined by a fixed nucleus, are
generally more movable than those of the coast, and the form of such dunes
is more or less modified by their want of consistence. Thus, the crescent or
falciform shape is described by all observers as more constant and
conspicuous in these sandhills than in those of littoral origin; they tend less
to unite in continuous ridges, and they rarely attain the height or other
dimensions of the dunes of the seashore. Meyer describes the sand-hills of
the Peruvian desert as perfectly falciform in shape and from seven to fifteen
Page 739
feet high, the chord of their arc measuring from twenty to seventy paces.
The slope of the convex face is described as very small, that of the concave
as high as 70 degrees or 80 degrees, and their surfaces were rippled. No
smaller dunes were observed, nor any in the process of formation. The
concave side uniformly faced the north-west, except towards the centre of
the desert, where, for a distance of one or two hundred paces, they
gradually opened to the west, and then again gradually resumed the former
position. Tschudi observed, in the same desert, two species of dunes, fixed
and movable, and he ascribes a falciform shape to the movable, a conical to
the fixed dunes, or medanos. "The medanos," he observes, "are hillock-like
elevations of sand, some having a firm, others a loose base. The former
[latter], which are always crescent-shaped, are from ten to twenty feet high,
and have an acute crest. The inner side is perpendicular, and the outer or
bow side forms an angle with a steep inclination downwards. [Footnote:
The dunes of the plains between Bokhara and the Oxus are all horse-shoe
shaped, convex towards the north, from which the prevailing wind blows.
On this side they are sloping, inside precipitous, and from fifteen to twenty
feet high.—Burnes, Journal in Bokhara, ii., pp. 1, 2.] When driven by
violent winds, the medanos pass rapidly over the plains. The smaller and
lighter ones move quickly forward, before the larger; but the latter soon
overtake and crush them, whilst they are themselves shivered by the
collision. These medanos assume all sorts of extraordinary figures, and
sometimes move along the plain in rows forming most intricate
labyrinths…. A plain often appears to be covered with a row of medanos,
and some days afterwards it is again restored to its level and uniform
aspect…. "The medanos with immovable bases are formed on the blocks of
rocks which are scattered about the plain. The sand is driven against them
by the wind, and as soon as it reaches the top point, it descends on the other
side until that is likewise covered; thus gradually arises a conical-formed
hill. [Footnote: The sand-hills observed by Desor in the Algerian desert
The slope of the convex face is described as very small, that of the concave
as high as 70 degrees or 80 degrees, and their surfaces were rippled. No
smaller dunes were observed, nor any in the process of formation. The
concave side uniformly faced the north-west, except towards the centre of
the desert, where, for a distance of one or two hundred paces, they
gradually opened to the west, and then again gradually resumed the former
position. Tschudi observed, in the same desert, two species of dunes, fixed
and movable, and he ascribes a falciform shape to the movable, a conical to
the fixed dunes, or medanos. "The medanos," he observes, "are hillock-like
elevations of sand, some having a firm, others a loose base. The former
[latter], which are always crescent-shaped, are from ten to twenty feet high,
and have an acute crest. The inner side is perpendicular, and the outer or
bow side forms an angle with a steep inclination downwards. [Footnote:
The dunes of the plains between Bokhara and the Oxus are all horse-shoe
shaped, convex towards the north, from which the prevailing wind blows.
On this side they are sloping, inside precipitous, and from fifteen to twenty
feet high.—Burnes, Journal in Bokhara, ii., pp. 1, 2.] When driven by
violent winds, the medanos pass rapidly over the plains. The smaller and
lighter ones move quickly forward, before the larger; but the latter soon
overtake and crush them, whilst they are themselves shivered by the
collision. These medanos assume all sorts of extraordinary figures, and
sometimes move along the plain in rows forming most intricate
labyrinths…. A plain often appears to be covered with a row of medanos,
and some days afterwards it is again restored to its level and uniform
aspect…. "The medanos with immovable bases are formed on the blocks of
rocks which are scattered about the plain. The sand is driven against them
by the wind, and as soon as it reaches the top point, it descends on the other
side until that is likewise covered; thus gradually arises a conical-formed
hill. [Footnote: The sand-hills observed by Desor in the Algerian desert
Page 740
were fixed, changing their form only on the surface as sand was blown to
and from them.—Sahara und Atlas, 1865, p. 21.] Entire hillock chains with
acute crests are formed in a similar manner…. On their southern declivities
are found vast masses of sand, drifted thither by the mid-day gales. The
northern declivity, though not steeper than the southern, is only sparingly
covered with sand. If a hillock chain somewhat distant from the sea extends
in a line parallel with the Andes, namely, from S. S. E. to N. N. W., the
western declivity is almost entirely free of sand, as it is driven to the plain
below by the south-east wind, which constantly alternates with the wind
from the south." [Footnote: Travels in Peru, New York, 1848, chap. ix.] It is
difficult to reconcile this description with that of Meyen, but if confidence
is to be reposed in the accuracy of either observer, the formation of the
sand-hills in question must be governed by very different laws from those
which determine the structure of coast dunes. Captain Gilliss, of the
American navy, found the sand-hills of the Peruvian desert to be in general
crescent-shaped, as described by Meyen, and a similar structure is said to
characterize the inland dunes of the Llano Estacado and other plateaus of
the North American desert, though those latter are of greater height and
other dimensions than those described by Meyen. There is no very obvious
explanation of this difference in form between maritime and inland sand-
hills, and the subject merits investigation. It is, however, probable that the
great mobility of the flying dunes of the Peruvian desert is an effect of their
dryness, no rain falling in that desert, and of the want of salt or other
binding material to hold their particles together.
Inland Sand Plains.
The inland sand plains of Europe are either derived from the drifting of
dunes or other beach sands, or consist of diluvial deposits, or are ancient
sea-beds uplifted by geological upheaval. As we have seen, when once the
interior of a dune is laid open to the wind, its contents ars soon scattered far
and from them.—Sahara und Atlas, 1865, p. 21.] Entire hillock chains with
acute crests are formed in a similar manner…. On their southern declivities
are found vast masses of sand, drifted thither by the mid-day gales. The
northern declivity, though not steeper than the southern, is only sparingly
covered with sand. If a hillock chain somewhat distant from the sea extends
in a line parallel with the Andes, namely, from S. S. E. to N. N. W., the
western declivity is almost entirely free of sand, as it is driven to the plain
below by the south-east wind, which constantly alternates with the wind
from the south." [Footnote: Travels in Peru, New York, 1848, chap. ix.] It is
difficult to reconcile this description with that of Meyen, but if confidence
is to be reposed in the accuracy of either observer, the formation of the
sand-hills in question must be governed by very different laws from those
which determine the structure of coast dunes. Captain Gilliss, of the
American navy, found the sand-hills of the Peruvian desert to be in general
crescent-shaped, as described by Meyen, and a similar structure is said to
characterize the inland dunes of the Llano Estacado and other plateaus of
the North American desert, though those latter are of greater height and
other dimensions than those described by Meyen. There is no very obvious
explanation of this difference in form between maritime and inland sand-
hills, and the subject merits investigation. It is, however, probable that the
great mobility of the flying dunes of the Peruvian desert is an effect of their
dryness, no rain falling in that desert, and of the want of salt or other
binding material to hold their particles together.
Inland Sand Plains.
The inland sand plains of Europe are either derived from the drifting of
dunes or other beach sands, or consist of diluvial deposits, or are ancient
sea-beds uplifted by geological upheaval. As we have seen, when once the
interior of a dune is laid open to the wind, its contents ars soon scattered far
Page 741
and wide over the adjacent country, and the beach sands, no longer checked
by the rampart which nature had constrained them to build against their
own encroachments, are also carried to considerable distances from the
coast. Few regions have suffered so much from this cause, in proportion to
their extent, as the peninsula of Jutland. So long as the woods, with which
nature had planted the Danish dunes, were spared, they seem to have been
stationary, and we have no historical evidence, of an earlier date than the
sixteenth century, that they had become in any way injurious. From that
period there are frequent notices of the invasions of cultivated grounds by
the sands; and excavations are constantly bringing to light proof of human
habitation and of agricultural industry, in former ages, on soils now buried
beneath deep drifts from the dunes and beaches of the seacoast. [Footnote:
For details, consult Andresen, Om Klitformationen, pp. 223, 236.]
Extensive tracts of valuable plain land in the Netherlands and in France
have been covered in the same way with a layer of sand deep enough to
render them infertile, and they can be restored to cultivation only by
processes analogous to those employed for fixing and improving the dunes.
[Footnote: When the deposit is not very deep, and the adjacent land lying to
the leeward of the prevailing winds is covered with water, or otherwise
worthless, the surface is sometimes freed from the drifts by repeated
harrowings, which loosen the sand, so that the wind takes it up and
transports it to grounds where accumulations of it are less injurious.]
Diluvial sand plains, also, have been reclaimed by these methods in the
Duchy of Austria, between Vienna and the Semmering ridge, in Jutland, and
in the great champaign country of Northern Germany, especially the Mark
Brandenburg, where artificial forests can be propagated with great ease, and
where, consequently, this branch of industry has been pursued on a great
scale, and with highly beneficial results, both as respects the supply of
forest products and the preparation of the soil for agricultural use.
by the rampart which nature had constrained them to build against their
own encroachments, are also carried to considerable distances from the
coast. Few regions have suffered so much from this cause, in proportion to
their extent, as the peninsula of Jutland. So long as the woods, with which
nature had planted the Danish dunes, were spared, they seem to have been
stationary, and we have no historical evidence, of an earlier date than the
sixteenth century, that they had become in any way injurious. From that
period there are frequent notices of the invasions of cultivated grounds by
the sands; and excavations are constantly bringing to light proof of human
habitation and of agricultural industry, in former ages, on soils now buried
beneath deep drifts from the dunes and beaches of the seacoast. [Footnote:
For details, consult Andresen, Om Klitformationen, pp. 223, 236.]
Extensive tracts of valuable plain land in the Netherlands and in France
have been covered in the same way with a layer of sand deep enough to
render them infertile, and they can be restored to cultivation only by
processes analogous to those employed for fixing and improving the dunes.
[Footnote: When the deposit is not very deep, and the adjacent land lying to
the leeward of the prevailing winds is covered with water, or otherwise
worthless, the surface is sometimes freed from the drifts by repeated
harrowings, which loosen the sand, so that the wind takes it up and
transports it to grounds where accumulations of it are less injurious.]
Diluvial sand plains, also, have been reclaimed by these methods in the
Duchy of Austria, between Vienna and the Semmering ridge, in Jutland, and
in the great champaign country of Northern Germany, especially the Mark
Brandenburg, where artificial forests can be propagated with great ease, and
where, consequently, this branch of industry has been pursued on a great
scale, and with highly beneficial results, both as respects the supply of
forest products and the preparation of the soil for agricultural use.
Page 742
As has been already observed, inland sands are generally looser, dryer,
and more inclined to drift, than those of the seacoast, where the moist and
saline atmosphere of the ocean keeps them always more or less humid and
cohesive. The sands of the valley of the Lower Euphrates—themselves
probably of submarine origin, and not derived from dunes are advancing to
the north-west with a rapidity which seems fabulous when compared with
the slow movement of the sand-hills of Gascony and the Low German
coasts. Loftus, speaking of Niliyya, an old Arab town a few miles east of
the ruins of Babylon, says that, "in 1848, the sand began to accumulate
around it, and in six years, the desert, within a radius of six miles, was
covered with little, undulating domes, while the ruins of the city were so
buried that it is now impossible to trace their original form or extent."
[Footnote: Travels and Researchs in Chaldaea, chap. ix.
Dwight mentions (Travels, vol. iii, p. 101) an instance of great mischief
from the depasturing of the beach grass which had been planted on a sand
plain in Cape Cod: "Here, about one thousand acres were entirely blown
away to the depth, in many places, of ten feet…. Not a green thing was
visible except the whortleberries, which tufted a few lonely hillocks rising
to the height of the original surface and prevented by this defence from
being blown away also. These, although they varied the prospect, added to
the gloom by their strongly picturesque appearance, by marking exactly the
original level of the plain, and by showing us in this manner the immensity
of the mass which had been thus carried away by the wind. The beach grass
had been planted here, and the ground had been formerly enclosed; but the
gates had been left open, and the cattle had destroyed this invaluable
plant."] Loftus considers this sand-flood as the "vanguard of those vast
drifts which advancing from the south-east, threaten eventually to
overwhelm Babylon and Baghdad." An observation of Layard, cited by
Loftus, appears to me to furnish a possible explanation of this irruption. He
"passed two or three places where the sand, issuing from the earth like
and more inclined to drift, than those of the seacoast, where the moist and
saline atmosphere of the ocean keeps them always more or less humid and
cohesive. The sands of the valley of the Lower Euphrates—themselves
probably of submarine origin, and not derived from dunes are advancing to
the north-west with a rapidity which seems fabulous when compared with
the slow movement of the sand-hills of Gascony and the Low German
coasts. Loftus, speaking of Niliyya, an old Arab town a few miles east of
the ruins of Babylon, says that, "in 1848, the sand began to accumulate
around it, and in six years, the desert, within a radius of six miles, was
covered with little, undulating domes, while the ruins of the city were so
buried that it is now impossible to trace their original form or extent."
[Footnote: Travels and Researchs in Chaldaea, chap. ix.
Dwight mentions (Travels, vol. iii, p. 101) an instance of great mischief
from the depasturing of the beach grass which had been planted on a sand
plain in Cape Cod: "Here, about one thousand acres were entirely blown
away to the depth, in many places, of ten feet…. Not a green thing was
visible except the whortleberries, which tufted a few lonely hillocks rising
to the height of the original surface and prevented by this defence from
being blown away also. These, although they varied the prospect, added to
the gloom by their strongly picturesque appearance, by marking exactly the
original level of the plain, and by showing us in this manner the immensity
of the mass which had been thus carried away by the wind. The beach grass
had been planted here, and the ground had been formerly enclosed; but the
gates had been left open, and the cattle had destroyed this invaluable
plant."] Loftus considers this sand-flood as the "vanguard of those vast
drifts which advancing from the south-east, threaten eventually to
overwhelm Babylon and Baghdad." An observation of Layard, cited by
Loftus, appears to me to furnish a possible explanation of this irruption. He
"passed two or three places where the sand, issuing from the earth like
Page 743
water, is called 'Aioun-er-rummal,' sand springs." These "springs" are very
probably merely the drifting of sand from the ancient subsoil, where the
protecting crust of aquatic deposit and vegetable earth has been broken
through, as in the case of the drift which arose from the upturning of an oak
mentioned on a former page. When the valley of the Euphrates was
regularly irrigated and cultivated, the underlying sands were bound by
moisture, alluvial slime, and vegetation; but now, that all improvement is
neglected, and the surface, no longer watered, has become parched,
powdery, and naked, a mere accidental fissure in the superficial stratum
may soon be enlarged to a wide opening, that will let loose sand enongh to
overwhelm a province. The Landes of Gascony. The most remarkable sand
plain of France lies at the south-western extremity of the empire, and is
generally known as the Landes, or heaths, of Gascony. Clave thus describes
it: "Composed of pure sand, resting on an impermeable stratum called alios,
the soil of the Landes was, for centuries, considered incapable of
cultivation. [Footnote: The alios, which from its color and consistence was
supposed to be a ferruginous formation, appears from recent observations to
contain little iron and to owe most of its peculiar properties to vegetable
elements carried down into the soil by the percolation of rain-water. See
Revue des Eaux et Forets for 1870, p. 801.] Parched in summer, drowned in
winter, it produced only ferns, rushes, and heath, and scarcely furnished
pasturage for a few half-starved flocks. To crown its miseries, this plain was
continually threatened by the encroachments of the dunes. Vast ridges of
sand, thrown up by the waves, for a distance of more than fifty leagues
along the coast, and continually renewed, were driven inland by the west
wind, and, as they rolled over the plain, they buried the soil and the
hamlets, overcame all resistance, and advanced with fearful regularity. The
whole province seemed devoted to certain destruction, when Bremontier
invented his method of fixing the dunes by plantations of the maritime
pine." [Footnote: Etudes Forestieres, p. 250. See, also, Reclus, La Terre, i.,
probably merely the drifting of sand from the ancient subsoil, where the
protecting crust of aquatic deposit and vegetable earth has been broken
through, as in the case of the drift which arose from the upturning of an oak
mentioned on a former page. When the valley of the Euphrates was
regularly irrigated and cultivated, the underlying sands were bound by
moisture, alluvial slime, and vegetation; but now, that all improvement is
neglected, and the surface, no longer watered, has become parched,
powdery, and naked, a mere accidental fissure in the superficial stratum
may soon be enlarged to a wide opening, that will let loose sand enongh to
overwhelm a province. The Landes of Gascony. The most remarkable sand
plain of France lies at the south-western extremity of the empire, and is
generally known as the Landes, or heaths, of Gascony. Clave thus describes
it: "Composed of pure sand, resting on an impermeable stratum called alios,
the soil of the Landes was, for centuries, considered incapable of
cultivation. [Footnote: The alios, which from its color and consistence was
supposed to be a ferruginous formation, appears from recent observations to
contain little iron and to owe most of its peculiar properties to vegetable
elements carried down into the soil by the percolation of rain-water. See
Revue des Eaux et Forets for 1870, p. 801.] Parched in summer, drowned in
winter, it produced only ferns, rushes, and heath, and scarcely furnished
pasturage for a few half-starved flocks. To crown its miseries, this plain was
continually threatened by the encroachments of the dunes. Vast ridges of
sand, thrown up by the waves, for a distance of more than fifty leagues
along the coast, and continually renewed, were driven inland by the west
wind, and, as they rolled over the plain, they buried the soil and the
hamlets, overcame all resistance, and advanced with fearful regularity. The
whole province seemed devoted to certain destruction, when Bremontier
invented his method of fixing the dunes by plantations of the maritime
pine." [Footnote: Etudes Forestieres, p. 250. See, also, Reclus, La Terre, i.,
Page 744
105, 106.] Although the Landes had been almost abandoned for ages, they
show numerous traces of ancient cultivation and prosperity, and it is
principally by means of the encroachments of the sands that they have
become reduced to their present desolate condition. The destruction of the
coast towns and harbors, which furnished markets for the products of the
plains, the damming up of the rivers, and the obstruction of the smaller
channels of natural drainage by the advance of the dunes, were no doubt
very influential causes; and if we add the drifting of the sea-sand over the
soil, we have at least a partial explanation of the decayed agriculture and
diminished population of this great waste. When the dunes were once
arrested, and the soil to the east of them was felt to be secure against
invasion by them, experiments, in the way of agricultural improvement, by
drainage and plantation, were commenced, and they have been attended
with such signal success, that the complete recovery of one of the dreariest
and most extensive wastes in Europe may be considered as both a probable
and a near event. [Footnote: Lavergne, Economie Rurale de la France, p.
300, estimates the area of the Landes of Gascony at 700,000 hectares, or
about 1,700,000 acres. The same author states (p. 301), that when the
Moors were driven from Spain by the blind cupidity and brutal intolerance
of the age, they demanded permission to establish themselves in this desert;
but political and religious prejudices prevented the granting of this liberty.
At this period the Moors were a far more cultivated people than their
Christian persecutors, and they had carried many arts, that of agriculttire
especially, to a higher pitch than any other European nation. But France was
not wise enough to accept what Spain had cast out, and the Landes
remained a waste for three centuries longer.
For a brilliant account of the improvement of the Landes, see Edmond
About, Le Progres, chap. vii.
show numerous traces of ancient cultivation and prosperity, and it is
principally by means of the encroachments of the sands that they have
become reduced to their present desolate condition. The destruction of the
coast towns and harbors, which furnished markets for the products of the
plains, the damming up of the rivers, and the obstruction of the smaller
channels of natural drainage by the advance of the dunes, were no doubt
very influential causes; and if we add the drifting of the sea-sand over the
soil, we have at least a partial explanation of the decayed agriculture and
diminished population of this great waste. When the dunes were once
arrested, and the soil to the east of them was felt to be secure against
invasion by them, experiments, in the way of agricultural improvement, by
drainage and plantation, were commenced, and they have been attended
with such signal success, that the complete recovery of one of the dreariest
and most extensive wastes in Europe may be considered as both a probable
and a near event. [Footnote: Lavergne, Economie Rurale de la France, p.
300, estimates the area of the Landes of Gascony at 700,000 hectares, or
about 1,700,000 acres. The same author states (p. 301), that when the
Moors were driven from Spain by the blind cupidity and brutal intolerance
of the age, they demanded permission to establish themselves in this desert;
but political and religious prejudices prevented the granting of this liberty.
At this period the Moors were a far more cultivated people than their
Christian persecutors, and they had carried many arts, that of agriculttire
especially, to a higher pitch than any other European nation. But France was
not wise enough to accept what Spain had cast out, and the Landes
remained a waste for three centuries longer.
For a brilliant account of the improvement of the Landes, see Edmond
About, Le Progres, chap. vii.
Page 745
The forest of Fontainebleau, which contains above 40,000 acres, is not a
plain, but its soil is composed almost wholly of sand, interspersed with
ledges of rock. The sand forms not less than ninety-eight per cent of the
earth, and, as it is almost without water, it would be a drifting desert but for
the artificial propagation of forest trees upon it. The Landes of Sologne and
of Brenne are less known than those of Gascony, because they are not upon
the old great lines of communication. They once compoaed a forest of
1,200,000 acres, but by clearing the woods have relapsed into their
primitive condition of a barren sand waste. Active efforts are now in
progress to reclaim them.]
In the northern part of Belgium, and extending across the confines of
Holland, is another very similar heath plain, called the Campine. This is a
vast sand flat, interspersed with marshes and inland dunes, and, until
recently, considered almost wholly incapable of cultivation. Enormous
sums had been expended in reclaiming it by draining and other familiar
agricultural processes, but without results at all proportional to the capital
invested. In 1849, the unimproved portion of the Campine was estimated at
little less than three hundred and fifty thousand acres. The example of
France prompted experiments in the planting of trees, especially the
maritime pine, upon this barren waste, and the results have now been such
as to show that its sands may both be fixed and made productive, not only
without loss, but with positive pecuniary advantage. [Footnote: Economie
Rurale de la Belgique, par Emile De Laveleye, Revue des Deux Mondes,
Juin, 1861, pp. 6l7-644. The quantity of land annually reclaimed on the
Campine is stated at about 4,000 acres. Canals for navigation and irrigation
have been constructed through the Campine, and it is said that its barren
sands, improved at an expense of one hundred dollars per acre, yield, from
the second year, a return of twenty-five dollars to the acre.]
plain, but its soil is composed almost wholly of sand, interspersed with
ledges of rock. The sand forms not less than ninety-eight per cent of the
earth, and, as it is almost without water, it would be a drifting desert but for
the artificial propagation of forest trees upon it. The Landes of Sologne and
of Brenne are less known than those of Gascony, because they are not upon
the old great lines of communication. They once compoaed a forest of
1,200,000 acres, but by clearing the woods have relapsed into their
primitive condition of a barren sand waste. Active efforts are now in
progress to reclaim them.]
In the northern part of Belgium, and extending across the confines of
Holland, is another very similar heath plain, called the Campine. This is a
vast sand flat, interspersed with marshes and inland dunes, and, until
recently, considered almost wholly incapable of cultivation. Enormous
sums had been expended in reclaiming it by draining and other familiar
agricultural processes, but without results at all proportional to the capital
invested. In 1849, the unimproved portion of the Campine was estimated at
little less than three hundred and fifty thousand acres. The example of
France prompted experiments in the planting of trees, especially the
maritime pine, upon this barren waste, and the results have now been such
as to show that its sands may both be fixed and made productive, not only
without loss, but with positive pecuniary advantage. [Footnote: Economie
Rurale de la Belgique, par Emile De Laveleye, Revue des Deux Mondes,
Juin, 1861, pp. 6l7-644. The quantity of land annually reclaimed on the
Campine is stated at about 4,000 acres. Canals for navigation and irrigation
have been constructed through the Campine, and it is said that its barren
sands, improved at an expense of one hundred dollars per acre, yield, from
the second year, a return of twenty-five dollars to the acre.]
Page 746
There are still unsubdued sand wastes in many parts of interior Europe
not familiarly known to tourists or even geographers. "Olkuez and
Schiewier in Poland," says Naumann, "lie in true sand deserts, and a
boundless plain of sand stretches around Ozenstockau, on which there
grows neither tree nor shrub. In heavy winds, this plain resembles a rolling
sea, and the sand-hills rise and disappear like the waves of the ocean. The
heaps of waste from the Olkuez mines are covered with sand to the depth of
four fathoms." [Footnote: Geognosie, ii., p. 1173.] No attempts have yet
been made to subdue the sands of Poland, but when peace and prosperity
shall be restored to that unhappy country, there is no reasonable doubt that
the measures, which have proved so successful on similar formations in
Germany and near Odessa, may be employed with advantage in the Polish
deserts. [Footnote: "Sixteen years ago," says an Odessa landholder, "I
attempted to fix the sand of the steppes, which covers the rocky ground to
the depth of a foot, and forms moving hillocks with every change of wind. I
tried acacias and pines in vain; nothing would grow in such a soil. At length
I planted the varnish tree, or ailanthus, which succeeded completely in
binding the sand." This result encouraged the proprietor to extend his
plantations over both dunes and sand steppes, and in the course ot sixteen
years this rapidly growing tree had formed real forests. Other landholders
have imitated his example with great advantage.—Rentsch, Der Wald, pp.
44, 45.]
CHAPTER VI.
GREAT PROJECTS OF PHYSICAL CHANGE ACCOMPLISHED OR PROPOSED BY
MAN.
Cutting of Isthmuses—Canal of Suez—Maritime Canals in Greece—
Canals
not familiarly known to tourists or even geographers. "Olkuez and
Schiewier in Poland," says Naumann, "lie in true sand deserts, and a
boundless plain of sand stretches around Ozenstockau, on which there
grows neither tree nor shrub. In heavy winds, this plain resembles a rolling
sea, and the sand-hills rise and disappear like the waves of the ocean. The
heaps of waste from the Olkuez mines are covered with sand to the depth of
four fathoms." [Footnote: Geognosie, ii., p. 1173.] No attempts have yet
been made to subdue the sands of Poland, but when peace and prosperity
shall be restored to that unhappy country, there is no reasonable doubt that
the measures, which have proved so successful on similar formations in
Germany and near Odessa, may be employed with advantage in the Polish
deserts. [Footnote: "Sixteen years ago," says an Odessa landholder, "I
attempted to fix the sand of the steppes, which covers the rocky ground to
the depth of a foot, and forms moving hillocks with every change of wind. I
tried acacias and pines in vain; nothing would grow in such a soil. At length
I planted the varnish tree, or ailanthus, which succeeded completely in
binding the sand." This result encouraged the proprietor to extend his
plantations over both dunes and sand steppes, and in the course ot sixteen
years this rapidly growing tree had formed real forests. Other landholders
have imitated his example with great advantage.—Rentsch, Der Wald, pp.
44, 45.]
CHAPTER VI.
GREAT PROJECTS OF PHYSICAL CHANGE ACCOMPLISHED OR PROPOSED BY
MAN.
Cutting of Isthmuses—Canal of Suez—Maritime Canals in Greece—
Canals
Page 747
to Dead Sea—Canals to Libyan Desert—Maritime Canals in Europe—Cape
Cod Canal—Changes in Caspian—Diversion of the Nile—Diversion of the
Rhine—Improvements in North American Hydrography—Soil below
Rock—Covering Rock with Earth—Desert Valleys—Effects of
Mining—Duponchel's Plans of Improvement—Action of Man on the
Weather—Resistance to Great Natural Forces—Incidental Effects of
Human
Action—Nothing small in Nature.
In a former chapter I spoke of the influence of human action on the
surface of the globe as immensely superior in degree to that exerted by
brute animals, if not essentially different from it in kind. The eminent
Italian geologist, Stoppani, goes further than I had ventured to do, and treats
the action of man as a new physical clement altogether sui generis.
According to him, the existence of man constitutes a geological period
which he designates as the ANTHROPOZOIC ERA. "The creation of man,"
says he, "was the introduction of a new element into nature, of a force
wholly unknown to earlier periods." "It is a new telluric force which in
power and universality may be compared to the greater forces of the earth."
[Foonote: Corso Di Geologia, Milano, 1873, vol ii., cap. xxxi., section
1327.] It has already been abundantly shown that, though the undesigned
and unforeseen results of man's action on the geographical conditions of the
earth have perhaps been hitherto greater and more revolutionary than the
effects specially aimed at by him, yet there is scarcely any assignable limit
to his present and prospective voluntary controlling power over terrestrial
nature.
Cutting of Marine Isthmuses.
Cod Canal—Changes in Caspian—Diversion of the Nile—Diversion of the
Rhine—Improvements in North American Hydrography—Soil below
Rock—Covering Rock with Earth—Desert Valleys—Effects of
Mining—Duponchel's Plans of Improvement—Action of Man on the
Weather—Resistance to Great Natural Forces—Incidental Effects of
Human
Action—Nothing small in Nature.
In a former chapter I spoke of the influence of human action on the
surface of the globe as immensely superior in degree to that exerted by
brute animals, if not essentially different from it in kind. The eminent
Italian geologist, Stoppani, goes further than I had ventured to do, and treats
the action of man as a new physical clement altogether sui generis.
According to him, the existence of man constitutes a geological period
which he designates as the ANTHROPOZOIC ERA. "The creation of man,"
says he, "was the introduction of a new element into nature, of a force
wholly unknown to earlier periods." "It is a new telluric force which in
power and universality may be compared to the greater forces of the earth."
[Foonote: Corso Di Geologia, Milano, 1873, vol ii., cap. xxxi., section
1327.] It has already been abundantly shown that, though the undesigned
and unforeseen results of man's action on the geographical conditions of the
earth have perhaps been hitherto greater and more revolutionary than the
effects specially aimed at by him, yet there is scarcely any assignable limit
to his present and prospective voluntary controlling power over terrestrial
nature.
Cutting of Marine Isthmuses.
Page 748
Besides the great enterprises of physical transformation of which I have
already spoken, other works of internal improvement or change have been
projected in ancient and modern times, the execution of which would
produce considerable, and, in some cases, extremely important, revolutions
in the face of the earth. Some of the schemes to which I refer are evidently
chimerical; others are difficult, indeed, but cannot be said to be
impracticable, though discouraged by the apprehension of disastrous
consequences from the disturbance of existing natural or artificial
arrangements; and there are still others, the accomplishment of which is
ultimately certain, though for the present forbidden by economical
considerations.
Nature sometimes mocks the cunning and the power of man by
spontaneously performing, for his benefit, works which he shrinks from
undertaking, and the execution of which by him she would resist with
unconquerable obstinacy. A dangerous sand bank, that all the enginery of
the world could not dredge out in a generation, may be carried off in a night
by a strong river-flood, or by a current impelled by a violent wind from an
unusual quarter, and a passage scarcely navigable by fishing-boats may be
thus converted into a commodious channel for the largest ship that floats
upon the ocean. In the remarkable gulf of Liimfjord in Jutland, referred to
in the preceding chapter, nature has given a singular example of a canal
which she alternately opens as a marine strait, and, by abutting again,
converts into a fresh-water lagoon. The Liimfjord was doubtless originally
an open channel from the Atlantic to the Baltic between two islands, but the
sand washed up by the sea blocked up the western entrance, and built a wall
of dunes to close it more firmly. This natural dike, as we have seen, has
been more than once broken through, and it is perhaps in the power of man,
either permanently to maintain the barrier, or to remove it and keep a
navigable channel constantly open. If the Liimfjord becomes an open strait,
the washing of sea-sand through it would perhaps block some of the belts
already spoken, other works of internal improvement or change have been
projected in ancient and modern times, the execution of which would
produce considerable, and, in some cases, extremely important, revolutions
in the face of the earth. Some of the schemes to which I refer are evidently
chimerical; others are difficult, indeed, but cannot be said to be
impracticable, though discouraged by the apprehension of disastrous
consequences from the disturbance of existing natural or artificial
arrangements; and there are still others, the accomplishment of which is
ultimately certain, though for the present forbidden by economical
considerations.
Nature sometimes mocks the cunning and the power of man by
spontaneously performing, for his benefit, works which he shrinks from
undertaking, and the execution of which by him she would resist with
unconquerable obstinacy. A dangerous sand bank, that all the enginery of
the world could not dredge out in a generation, may be carried off in a night
by a strong river-flood, or by a current impelled by a violent wind from an
unusual quarter, and a passage scarcely navigable by fishing-boats may be
thus converted into a commodious channel for the largest ship that floats
upon the ocean. In the remarkable gulf of Liimfjord in Jutland, referred to
in the preceding chapter, nature has given a singular example of a canal
which she alternately opens as a marine strait, and, by abutting again,
converts into a fresh-water lagoon. The Liimfjord was doubtless originally
an open channel from the Atlantic to the Baltic between two islands, but the
sand washed up by the sea blocked up the western entrance, and built a wall
of dunes to close it more firmly. This natural dike, as we have seen, has
been more than once broken through, and it is perhaps in the power of man,
either permanently to maintain the barrier, or to remove it and keep a
navigable channel constantly open. If the Liimfjord becomes an open strait,
the washing of sea-sand through it would perhaps block some of the belts
Page 749
and small channels now important for the navigation of the Baltic, and the
direct introduction of a tidal current might produce very perceptible effects
on the hydrography of the Cattegat.
When we consider the number of narrow necks or isthmuses which
separate gulfs and bays of the sea from each other, or from the main ocean,
and take into account the time and cost, and risks of navigation which
would be saved by executing channels to connect such waters, and thus
avoiding the necessity of doubling long capes and promontories, or even
continents, it seems strange that more of the enterprise and money which
have been so lavishly expended in forming artificial rivers for internal
navigation should not have been bestowed upon the construction of
maritime canals. Many such have been projected in early and in recent ages,
and some trifling cuts between marine waters had been actually made; but
before the construction of the Suez Canal, no work of this sort, possessing
real geographical or even commercial importance, had been effected.
These enterprises are attended with difficulties and open to objections
which are not, at first sight, obvious. Nature guards well the chains by
which she connects promontories with mainlands, and binds continents
together. Isthmuses are usually composed of adamantine rock or of shifting
sands—the latter being much the more refractory material to deal with. In
all such works there is a necessity for deep excavation below low-water
mark—always a matter of great difficulty; the dimensions of channels for
sea-going ships must be much greater than those of canals of inland
navigation; the height of the masts or smokepipes of that class of vessels
would often render bridging impossible, and thus a ship-canal might
obstruct a communication more important than that which it was intended
to promote; the securing of the entrances of marine canals and the
construction of ports at their termini would in general be difficult and
expensive, and the harbors and the channel which connected them would be
direct introduction of a tidal current might produce very perceptible effects
on the hydrography of the Cattegat.
When we consider the number of narrow necks or isthmuses which
separate gulfs and bays of the sea from each other, or from the main ocean,
and take into account the time and cost, and risks of navigation which
would be saved by executing channels to connect such waters, and thus
avoiding the necessity of doubling long capes and promontories, or even
continents, it seems strange that more of the enterprise and money which
have been so lavishly expended in forming artificial rivers for internal
navigation should not have been bestowed upon the construction of
maritime canals. Many such have been projected in early and in recent ages,
and some trifling cuts between marine waters had been actually made; but
before the construction of the Suez Canal, no work of this sort, possessing
real geographical or even commercial importance, had been effected.
These enterprises are attended with difficulties and open to objections
which are not, at first sight, obvious. Nature guards well the chains by
which she connects promontories with mainlands, and binds continents
together. Isthmuses are usually composed of adamantine rock or of shifting
sands—the latter being much the more refractory material to deal with. In
all such works there is a necessity for deep excavation below low-water
mark—always a matter of great difficulty; the dimensions of channels for
sea-going ships must be much greater than those of canals of inland
navigation; the height of the masts or smokepipes of that class of vessels
would often render bridging impossible, and thus a ship-canal might
obstruct a communication more important than that which it was intended
to promote; the securing of the entrances of marine canals and the
construction of ports at their termini would in general be difficult and
expensive, and the harbors and the channel which connected them would be
Page 750
extremely liable to fill up by deposits washed in from sea and shore.
Besides all this there is, in many cases, an alarming uncertainty as to the
effects of joining together waters which nature has put asunder. A new
channel may deflect strong currents from safe courses, and thus occasion
destructive erosion of shores otherwise secure, or promote the
transportation of sand or slime to block up important harbors, or it may
furnish a powerful enemy with dangerous facilities for hostile operations
along the coast. The most colossal project of canalization ever suggested,
whether we consider the physical difficulties of its execution, the magnitude
and importance of the waters proposed to be united, or the distance which
would be saved in navigation, is that of a channel between the Gulf of
Mexico and the Pacific, across the Isthmus of Darien. I do not now speak of
a lock-canal, by way of the Lake of Nicaragua or any other route—for such
a work would not differ essentially from other canals, and would scarcely
possess a geographical character—but of an open cut between the two seas.
The late survey by Captain Selfridge, showing that the lowest point on the
dividing ridge is 763 feet above the sea-level, must be considered as
determining in the negative the question of the possibility of such a cut, by
any means now at the control of man; and both the sanguine expectations of
benefits, and the dreary suggestions of danger, from the realization of this
great dream, may now be dismissed as equally chimerical.
Suez Canal.
The cutting of the Isthmus of Suez—the grandest and most truly
cosmopolite physical improvement ever undertaken by man—threatens
none of these dangers, and its only immediate geographical effect will
probably be that interchange between the aquatic animal and vegetable life
of two seas and two zones to which I alluded in a former chapter. [Footnote:
According to an article by Ascherson, in Petermann's Mitthielungen, vol.
Besides all this there is, in many cases, an alarming uncertainty as to the
effects of joining together waters which nature has put asunder. A new
channel may deflect strong currents from safe courses, and thus occasion
destructive erosion of shores otherwise secure, or promote the
transportation of sand or slime to block up important harbors, or it may
furnish a powerful enemy with dangerous facilities for hostile operations
along the coast. The most colossal project of canalization ever suggested,
whether we consider the physical difficulties of its execution, the magnitude
and importance of the waters proposed to be united, or the distance which
would be saved in navigation, is that of a channel between the Gulf of
Mexico and the Pacific, across the Isthmus of Darien. I do not now speak of
a lock-canal, by way of the Lake of Nicaragua or any other route—for such
a work would not differ essentially from other canals, and would scarcely
possess a geographical character—but of an open cut between the two seas.
The late survey by Captain Selfridge, showing that the lowest point on the
dividing ridge is 763 feet above the sea-level, must be considered as
determining in the negative the question of the possibility of such a cut, by
any means now at the control of man; and both the sanguine expectations of
benefits, and the dreary suggestions of danger, from the realization of this
great dream, may now be dismissed as equally chimerical.
Suez Canal.
The cutting of the Isthmus of Suez—the grandest and most truly
cosmopolite physical improvement ever undertaken by man—threatens
none of these dangers, and its only immediate geographical effect will
probably be that interchange between the aquatic animal and vegetable life
of two seas and two zones to which I alluded in a former chapter. [Footnote:
According to an article by Ascherson, in Petermann's Mitthielungen, vol.
Page 751
xvii., p. 247, the sea-grass floras of the opposite sides of the Isthmus of
Suez are as different as possible. It does not appear whether they have yet
intermixed.] A collateral feature of this great enterprise deserves notice as
possessing no inconsiderable geographical importance. I refer to the conduit
or conduits constructed from the Nile to the isthmus, primarily to supply
fresh water to the laborers on the great canal, and ultimately to serve as
aqueducts for the city of Suez and other towns on the line of the canal, and
for the irrigation and reclamation of a large extent of desert soil. In the
flourishing days of the Egyptian empire, the waters of the Nile were carried
over important districts cast of the river. In later ages, most of this territory
relapsed into a desert, from the decay of the canals which once fertilized it.
There is no difficulty in restoring the ancient channels, or in constructing
new, and thus watering not only all the soil that the wisdom of the Pharaohs
had improved, but much additional land. Hundreds of square miles of arid
sand waste would thus be converted into fields of perennial verdure, and the
geography of Lower Egypt would be thereby sensibly changed.
Considerable towns are growing up at both ends of the channel, and at
intermediate points, all depending on the maintenance of aqueducts from
the Nile, both for water and for the irrigation of the neighboring fields
which are to supply them with bread. Important interests will thus be
created, which will secure the permanence of the hydraulic works and of the
geographical changes produced by them, and Suez, or Port Said, or
Ismailieh, may become the capital of the government which has been so
long established at Cairo. Maritime Canals in Greece. A maritime canal
executed and another projected in ancient times, the latter of which is again
beginning to excite attention, deserve some notice, though their importance
is of a commercial rather than a geographical character. The first of those is
the cut made by Xerxes through the rock which connects the promontory of
Mount Athos with the mainland; the other, a navigable canal through the
Isthmus of Corinth. In spite of the testimony of Herodotus and Thucydides,
Suez are as different as possible. It does not appear whether they have yet
intermixed.] A collateral feature of this great enterprise deserves notice as
possessing no inconsiderable geographical importance. I refer to the conduit
or conduits constructed from the Nile to the isthmus, primarily to supply
fresh water to the laborers on the great canal, and ultimately to serve as
aqueducts for the city of Suez and other towns on the line of the canal, and
for the irrigation and reclamation of a large extent of desert soil. In the
flourishing days of the Egyptian empire, the waters of the Nile were carried
over important districts cast of the river. In later ages, most of this territory
relapsed into a desert, from the decay of the canals which once fertilized it.
There is no difficulty in restoring the ancient channels, or in constructing
new, and thus watering not only all the soil that the wisdom of the Pharaohs
had improved, but much additional land. Hundreds of square miles of arid
sand waste would thus be converted into fields of perennial verdure, and the
geography of Lower Egypt would be thereby sensibly changed.
Considerable towns are growing up at both ends of the channel, and at
intermediate points, all depending on the maintenance of aqueducts from
the Nile, both for water and for the irrigation of the neighboring fields
which are to supply them with bread. Important interests will thus be
created, which will secure the permanence of the hydraulic works and of the
geographical changes produced by them, and Suez, or Port Said, or
Ismailieh, may become the capital of the government which has been so
long established at Cairo. Maritime Canals in Greece. A maritime canal
executed and another projected in ancient times, the latter of which is again
beginning to excite attention, deserve some notice, though their importance
is of a commercial rather than a geographical character. The first of those is
the cut made by Xerxes through the rock which connects the promontory of
Mount Athos with the mainland; the other, a navigable canal through the
Isthmus of Corinth. In spite of the testimony of Herodotus and Thucydides,
Page 752
the Romans classed the canal of Xerxes among the fables of "mendacious
Greece," and yet traces of it are perfectly distinct at the present day through
its whole extent, except at a single point where, after it had become so
choked as to be no longer navigable, it was probably filled up to facilitate
communication by land between the promontory and the country in the rear
of it. The emperor Nero commenced the construction of a canal across the
Isthmus of Corinth, solely to facilitate the importation of grain from the
East for distribution among the citizens of Rome—for the encouragement
of general commerce was no part of the policy either of the republic or the
empire, and though the avidity of traders, chiefly foreigners, secured to the
luxury of the imperial city an abundant supply of far-fetched wares, yet
Rome had nothing to export in return. The line of Nero's excavations is still
traceable for three-quarters of a mile, or more than a fifth of the total
distance between gulf and gulf.
If the fancy kingdom of Greece shall ever become a sober reality, escape
from its tutelage and acquire such a moral as well as political status that its
own capitalists—who now prefer to establish themselves and employ their
funds anywhere else rather than in their native land—have any confidence
in the permanency of its institutions, a navigable channel may be opened
between the gulfs of Lepanto and AEgina. The annexation of the Ionian
Islands to Greece will make such a work almost a political necessity, and it
would not only furnish valuable facilities for domestic intercourse, but
become an important channel of communication between the Levant and
the countries bordering on the Adriatic, or conducting their trade through
that sea. SHort as is the distance, the work would be a somewhat formidable
undertaking, for the lowest point of the summit ridge of the isthmus is
stated to be 246 feet above the water, and consequently the depth of
excavation must be not less than 275 feet. As I have said, the importance of
this latter canal and of a navigable channel between Mount Athos and the
continent would be chiefly commercial, but both of them would be
Greece," and yet traces of it are perfectly distinct at the present day through
its whole extent, except at a single point where, after it had become so
choked as to be no longer navigable, it was probably filled up to facilitate
communication by land between the promontory and the country in the rear
of it. The emperor Nero commenced the construction of a canal across the
Isthmus of Corinth, solely to facilitate the importation of grain from the
East for distribution among the citizens of Rome—for the encouragement
of general commerce was no part of the policy either of the republic or the
empire, and though the avidity of traders, chiefly foreigners, secured to the
luxury of the imperial city an abundant supply of far-fetched wares, yet
Rome had nothing to export in return. The line of Nero's excavations is still
traceable for three-quarters of a mile, or more than a fifth of the total
distance between gulf and gulf.
If the fancy kingdom of Greece shall ever become a sober reality, escape
from its tutelage and acquire such a moral as well as political status that its
own capitalists—who now prefer to establish themselves and employ their
funds anywhere else rather than in their native land—have any confidence
in the permanency of its institutions, a navigable channel may be opened
between the gulfs of Lepanto and AEgina. The annexation of the Ionian
Islands to Greece will make such a work almost a political necessity, and it
would not only furnish valuable facilities for domestic intercourse, but
become an important channel of communication between the Levant and
the countries bordering on the Adriatic, or conducting their trade through
that sea. SHort as is the distance, the work would be a somewhat formidable
undertaking, for the lowest point of the summit ridge of the isthmus is
stated to be 246 feet above the water, and consequently the depth of
excavation must be not less than 275 feet. As I have said, the importance of
this latter canal and of a navigable channel between Mount Athos and the
continent would be chiefly commercial, but both of them would be
Page 753
conspicuous instances of the control of man over nature in a field where he
has thus far done little to interfere with her spontaneous arrangements. If
they were constructed upon such a scale as to admit of the free passage of
the water through them, in either direction, as the prevailing winds should
impel it, they would exercise a certain influence on the coast currents,
which are important as hydrographical elements, and also as producing
abrasion of the coast and a drift at the bottom of seas, and hence they would
be entitled to rank higher than simply as artificial means of transit. It has
been thought practicable to cut a canal across the peninsula of Gallipoli
from the outlet of the Sea of Marmora into the Gulf of Saros. It may be
doubted whether the mechanical difficulties of such a work would not be
found insuperable; but when Constantinople shall recover the important
political and commercial rank which naturally belongs to her, the execution
of such a canal will be recommended by strong reasons of military
expediency, as well as by the interests of trade. An open channel across the
peninsula would divert a portion of the water which now flows through the
Dardanelles, diminishing the rapidity of that powerful current, and thus in
part remove the difficulties which obstruct the navigation of the strait. It
would considerably abridge the distance by water between Constantinople
and the northern coast of the AEgean, and it would have the important
advantage of obliging an enemy to maintain two blockading fleets instead
of one.
Canals Communicating with Dead Sea.
The project of Captain Allen for opening a new route to India by cuts
between the Mediterranean and the Dead Sea, and between the Dead Sea
and the Red Sea, presents many interesting considerations. [Footnote: The
Dead Sea a new Route to India. 2 vols. 12mo, London, 1855.] The
hypsometrical observations of Bertou, Roth, and others, render it highly
has thus far done little to interfere with her spontaneous arrangements. If
they were constructed upon such a scale as to admit of the free passage of
the water through them, in either direction, as the prevailing winds should
impel it, they would exercise a certain influence on the coast currents,
which are important as hydrographical elements, and also as producing
abrasion of the coast and a drift at the bottom of seas, and hence they would
be entitled to rank higher than simply as artificial means of transit. It has
been thought practicable to cut a canal across the peninsula of Gallipoli
from the outlet of the Sea of Marmora into the Gulf of Saros. It may be
doubted whether the mechanical difficulties of such a work would not be
found insuperable; but when Constantinople shall recover the important
political and commercial rank which naturally belongs to her, the execution
of such a canal will be recommended by strong reasons of military
expediency, as well as by the interests of trade. An open channel across the
peninsula would divert a portion of the water which now flows through the
Dardanelles, diminishing the rapidity of that powerful current, and thus in
part remove the difficulties which obstruct the navigation of the strait. It
would considerably abridge the distance by water between Constantinople
and the northern coast of the AEgean, and it would have the important
advantage of obliging an enemy to maintain two blockading fleets instead
of one.
Canals Communicating with Dead Sea.
The project of Captain Allen for opening a new route to India by cuts
between the Mediterranean and the Dead Sea, and between the Dead Sea
and the Red Sea, presents many interesting considerations. [Footnote: The
Dead Sea a new Route to India. 2 vols. 12mo, London, 1855.] The
hypsometrical observations of Bertou, Roth, and others, render it highly
Page 754
probable, if not certain, that the watershed in the Wadi-el-Araba between
the Dead Sea and the Red Sea is not less than three hundred feet above the
main level of the latter, and if this is so, the execution of a canal from the
one sea to the other is quite out of the question. But the summit level
between the Mediterranean and the Jordan, near Jezreel, is believed to be
little, if at all, more than one hundred feet above the sea, and the distance is
so short that the cutting of a channel through the dividing ridge would
probably be found by no means an impracticable undertaking. Although,
therefore, we have no reason to believe it possible to open a navigable
channel to India by way of the Dead Sea, there is not much doubt that the
basin of the latter might be made accessible from the Mediterranean.
The level of the Dead Sea lies 1,316.7 feet below that of the ocean. It is
bounded east and west by mountain ridges, rising to the height of from
2,000 to 4,000 feet above the ocean. From its southern end, a depression
called the Wadi-el-Araba extends to the Gulf of Akaba, the eastern arm of
the Red Sea. The Jordan empties into the northern extremity of the Dead
Sea, after having passed through the Lake of Tiberias at an elevation of
663.4 feet above the Dead Sea, or 653.3 below the Mediterranean, and
drains a considerable valley north of the lake, as well as the plain of
Jericho, which lies between the lake and the sea. If the waters of the
Mediterranean were admitted freely into the basin of the Dead Sea, they
would raise its surface to the general level of the ocean, and consequently
flood all the dry land below that level within the basin. I do not know that
accurate levels have been taken in the valley of the Jordan above the Lake
of Tiberias, and our information is very vague as to the hypsometry of the
northern part of the Wadi-el-Araba. As little do we know where a contour
line, carried around the basin at the level of the Mediterranean, would strike
its eastern and western borders. We cannot, therefore, accurately compute
the extent of now dry land which would be covered by the admission of the
waters of the Mediterranean, or the area of the inland sea which would be
the Dead Sea and the Red Sea is not less than three hundred feet above the
main level of the latter, and if this is so, the execution of a canal from the
one sea to the other is quite out of the question. But the summit level
between the Mediterranean and the Jordan, near Jezreel, is believed to be
little, if at all, more than one hundred feet above the sea, and the distance is
so short that the cutting of a channel through the dividing ridge would
probably be found by no means an impracticable undertaking. Although,
therefore, we have no reason to believe it possible to open a navigable
channel to India by way of the Dead Sea, there is not much doubt that the
basin of the latter might be made accessible from the Mediterranean.
The level of the Dead Sea lies 1,316.7 feet below that of the ocean. It is
bounded east and west by mountain ridges, rising to the height of from
2,000 to 4,000 feet above the ocean. From its southern end, a depression
called the Wadi-el-Araba extends to the Gulf of Akaba, the eastern arm of
the Red Sea. The Jordan empties into the northern extremity of the Dead
Sea, after having passed through the Lake of Tiberias at an elevation of
663.4 feet above the Dead Sea, or 653.3 below the Mediterranean, and
drains a considerable valley north of the lake, as well as the plain of
Jericho, which lies between the lake and the sea. If the waters of the
Mediterranean were admitted freely into the basin of the Dead Sea, they
would raise its surface to the general level of the ocean, and consequently
flood all the dry land below that level within the basin. I do not know that
accurate levels have been taken in the valley of the Jordan above the Lake
of Tiberias, and our information is very vague as to the hypsometry of the
northern part of the Wadi-el-Araba. As little do we know where a contour
line, carried around the basin at the level of the Mediterranean, would strike
its eastern and western borders. We cannot, therefore, accurately compute
the extent of now dry land which would be covered by the admission of the
waters of the Mediterranean, or the area of the inland sea which would be
Page 755
thus created. Its length, however, would certainly exceed one hundred and
fifty miles, and its mean breadth, including its gulfs and bays, could
scarcely be less than fifteen, perhaps even twenty. It would cover very little
ground now occupied by civilized or even uncivilized man, though some of
the soil which would be submerged—for instance, that watered by the
Fountain of Elisha and other neighboring sources—is of great fertility, and,
under a wiser government and better civil institutions, might rise to
importance, because, from its depression, it possesses a very warm climate,
and might supply South-eastern Europe with tropical products more readily
than they can be obtained from any other source. Such a canal and sea
would be of no present commercial importance, because they would give
access to no new markets or sources of supply; but when the fertile valleys
and the deserted plains cast of the Jordan shall be reclaimed to agriculture
and civilization, these waters would furnish a channel of communication
which might become the medium of a very extensive trade. Whatever might
be the economical results of the opening and filling of the Dead Sea basin,
the creation of a new evaporable area, adding not less than 2,000 or perhaps
3,000 square miles to the present fluid surface of Syria, could not fail to
produce important meteorological effects. The climate of Syria would
probably be tempered, its precipitation and its fertility increased, the
courses of its winds and the electrical condition of its atmosphere modified.
The present organic life of the valley would be extinguished, and many
tribes of plants and animals would emigrate from the Mediterranean to the
new home which human art had prepared for them. It is possible, too, that
the addition of 1,300 feet, or forty atmospheres, of hydrostatic pressure
upon the bottom of the basin might disturb the equilibrium between the
internal and the external forces of the crust of the earth at this point of
abnormal configuration, and thus produce geological convulsions the
intensity of which cannot be even conjectured.
fifty miles, and its mean breadth, including its gulfs and bays, could
scarcely be less than fifteen, perhaps even twenty. It would cover very little
ground now occupied by civilized or even uncivilized man, though some of
the soil which would be submerged—for instance, that watered by the
Fountain of Elisha and other neighboring sources—is of great fertility, and,
under a wiser government and better civil institutions, might rise to
importance, because, from its depression, it possesses a very warm climate,
and might supply South-eastern Europe with tropical products more readily
than they can be obtained from any other source. Such a canal and sea
would be of no present commercial importance, because they would give
access to no new markets or sources of supply; but when the fertile valleys
and the deserted plains cast of the Jordan shall be reclaimed to agriculture
and civilization, these waters would furnish a channel of communication
which might become the medium of a very extensive trade. Whatever might
be the economical results of the opening and filling of the Dead Sea basin,
the creation of a new evaporable area, adding not less than 2,000 or perhaps
3,000 square miles to the present fluid surface of Syria, could not fail to
produce important meteorological effects. The climate of Syria would
probably be tempered, its precipitation and its fertility increased, the
courses of its winds and the electrical condition of its atmosphere modified.
The present organic life of the valley would be extinguished, and many
tribes of plants and animals would emigrate from the Mediterranean to the
new home which human art had prepared for them. It is possible, too, that
the addition of 1,300 feet, or forty atmospheres, of hydrostatic pressure
upon the bottom of the basin might disturb the equilibrium between the
internal and the external forces of the crust of the earth at this point of
abnormal configuration, and thus produce geological convulsions the
intensity of which cannot be even conjectured.
Page 756
It is now established by the observations of Rohlf and others that Strabo
was right in asserting that a considerable part of the Libyan desert, or
Sahara, lay below the level of the Mediterranean. At some points the
depression exceeds 325 feet, and at Siwah, in the oasis of Jupiter Ammon, it
is not less than 130 feet. It has been proposed to cut a canal through the
coast dunes, on the shore south of the Syrtis Major, or Dschnn el Kebrit of
the Arabs, and another project is to reopen the communication which
appears to have once existed between the Palus Tritonis, or Sebcha el
Nandid, and the Syrtis Parva. As we do not know the southern or eastern
limits of this depression, we cannot determine the area which would thus be
covered with water, but it would certainly be many thousands of square
miles in extent, and the climatic effects would doubtless be sensible through
a considerable part of Northern Africa, and possibly even in Europe. The
rapid evaporation would require a constant influx of water from the
Mediterranean, which might perhaps perceptibly influence the current
through the Straits of Gibraltar.
Maritime Canals in Europe.
A great navigable cut across the peninsula of Jutland, forming a new and
short route between the North Sea and the Baltic, if not actually
commenced, is determined upon. The motives for opening such a
communication are perhaps rather to be found in political than in
geographical or even commercial considerations, but it will not be without
an important bearing on the material interests of all the countries to whose
peoples it will furnish new facilities for communication and traffic.
The North Holland canal between the Helder and the port of Amsterdam,
a distance of fifty miles, executed a few years since at a cost of $5,000,000,
and with dimensions admitting the passage of a frigate, was a magnificent
was right in asserting that a considerable part of the Libyan desert, or
Sahara, lay below the level of the Mediterranean. At some points the
depression exceeds 325 feet, and at Siwah, in the oasis of Jupiter Ammon, it
is not less than 130 feet. It has been proposed to cut a canal through the
coast dunes, on the shore south of the Syrtis Major, or Dschnn el Kebrit of
the Arabs, and another project is to reopen the communication which
appears to have once existed between the Palus Tritonis, or Sebcha el
Nandid, and the Syrtis Parva. As we do not know the southern or eastern
limits of this depression, we cannot determine the area which would thus be
covered with water, but it would certainly be many thousands of square
miles in extent, and the climatic effects would doubtless be sensible through
a considerable part of Northern Africa, and possibly even in Europe. The
rapid evaporation would require a constant influx of water from the
Mediterranean, which might perhaps perceptibly influence the current
through the Straits of Gibraltar.
Maritime Canals in Europe.
A great navigable cut across the peninsula of Jutland, forming a new and
short route between the North Sea and the Baltic, if not actually
commenced, is determined upon. The motives for opening such a
communication are perhaps rather to be found in political than in
geographical or even commercial considerations, but it will not be without
an important bearing on the material interests of all the countries to whose
peoples it will furnish new facilities for communication and traffic.
The North Holland canal between the Helder and the port of Amsterdam,
a distance of fifty miles, executed a few years since at a cost of $5,000,000,
and with dimensions admitting the passage of a frigate, was a magnificent
Page 757
enterprise, but it is thrown quite into the shade by the shorter channel now
in process of construction for bringing that important city into almost direct
communication with the North Sea, and thus restoring to it something at
least of its ancient commercial importance. The work involves some of the
heaviest hydraulic operations yet undertaken, including the construction of
great dams, locks, dikes, embankments, and the execution of draining
works and deep cutting under circumstances of extreme difficulty. In the
course of these labors many novel problems have presented themselves for
practical solution by the ingenuity of modern engineers, and the now
inventions and processes thus necessitated are valuable contributions to our
means of physical improvement.
Cape Cod Canal.
The opening of a navigable cut through the narrow neck which separates
the southern part of Cape Cod Bay in Massachusetts from the Atlantic, was
long ago suggested, and there are few coast improvements on the Atlantic
shores of the United States which are recommended by higher
considerations of utility. It would save the most important coasting trade of
the United States the long and dangerous navigation around Cape Cod,
afford a new and safer entrance to Boston harbor for vessels from Southern
ports, secure a choice of passages, thus permitting arrivals upon the coast
and departures from it at periods when wind and weather might otherwise
prevent them, and furnish a most valuable internal communication in case
of coast blockade by a foreign power. The difficulties of the undertaking are
no doubt formidable, but the expense of maintenance and the uncertainty of
the effects of currents getting through the new strait are still more serious
objections. [Footnote: The opening of a channel across Cape Cod would
have, though perhaps to a smaller extent, the same effects in interchanging
the animal life of the southern and northern shores of the isthmus, as in the
in process of construction for bringing that important city into almost direct
communication with the North Sea, and thus restoring to it something at
least of its ancient commercial importance. The work involves some of the
heaviest hydraulic operations yet undertaken, including the construction of
great dams, locks, dikes, embankments, and the execution of draining
works and deep cutting under circumstances of extreme difficulty. In the
course of these labors many novel problems have presented themselves for
practical solution by the ingenuity of modern engineers, and the now
inventions and processes thus necessitated are valuable contributions to our
means of physical improvement.
Cape Cod Canal.
The opening of a navigable cut through the narrow neck which separates
the southern part of Cape Cod Bay in Massachusetts from the Atlantic, was
long ago suggested, and there are few coast improvements on the Atlantic
shores of the United States which are recommended by higher
considerations of utility. It would save the most important coasting trade of
the United States the long and dangerous navigation around Cape Cod,
afford a new and safer entrance to Boston harbor for vessels from Southern
ports, secure a choice of passages, thus permitting arrivals upon the coast
and departures from it at periods when wind and weather might otherwise
prevent them, and furnish a most valuable internal communication in case
of coast blockade by a foreign power. The difficulties of the undertaking are
no doubt formidable, but the expense of maintenance and the uncertainty of
the effects of currents getting through the new strait are still more serious
objections. [Footnote: The opening of a channel across Cape Cod would
have, though perhaps to a smaller extent, the same effects in interchanging
the animal life of the southern and northern shores of the isthmus, as in the
Page 758
case of the Suez Canal; for although the breadth of Cape Cod does not
anywhere exceed twenty miles, and is in some places reduced to one, it
appears from the official reports on the Natural History of Massachusetts,
that the population of the opposite waters differs widely in species.
Not having the original documents at hand, I quote an extract from the
Report on the Invertebrate Animals of Mass., given by Thoreau, Excursions,
p. 69: "The distribution of the marine shells is well worthy of notice as a
geological fact. Cape Cod, the right arm of the Commonwealth, reaches out
into the ocean some fifty or sixty miles. It is nowhere many miles wide; but
this narrow point of land has hitherto proved a barrier to the migration of
many species of mollusca. Several genera and numerous species, which are
separated by the intervention of only a few miles of land, are effectually
prevented from mingling by the Cape, and do not pass from one side to the
other. … Of the one hundred and ninety-seven marine species, eighty-three
do not pass to the south shore, and fifty are not found on the north shore of
the Cape."
Probably the distribution of the species of mollusks is affected by
unknown local conditions, and therefore an open canal across the Cape
might not make every species that inhabits the waters on one side common
to those of the other; but there can be no doubt that there would be a
considerable migration in both directions.
The fact stated in the report may suggest an important caution in drawing
conclusions upon the relative age of formations from the character of their
fossils. Had a geological movement or movements upheaved to different
levels the bottoms of waters thus separated by a narrow isthmus, and
dislocated the connection between those bottoms, naturalists, in after ages,
reasoning from the character of the fossil faunas, might have assigned them
to different, and perhaps very widely distant, periods.]
anywhere exceed twenty miles, and is in some places reduced to one, it
appears from the official reports on the Natural History of Massachusetts,
that the population of the opposite waters differs widely in species.
Not having the original documents at hand, I quote an extract from the
Report on the Invertebrate Animals of Mass., given by Thoreau, Excursions,
p. 69: "The distribution of the marine shells is well worthy of notice as a
geological fact. Cape Cod, the right arm of the Commonwealth, reaches out
into the ocean some fifty or sixty miles. It is nowhere many miles wide; but
this narrow point of land has hitherto proved a barrier to the migration of
many species of mollusca. Several genera and numerous species, which are
separated by the intervention of only a few miles of land, are effectually
prevented from mingling by the Cape, and do not pass from one side to the
other. … Of the one hundred and ninety-seven marine species, eighty-three
do not pass to the south shore, and fifty are not found on the north shore of
the Cape."
Probably the distribution of the species of mollusks is affected by
unknown local conditions, and therefore an open canal across the Cape
might not make every species that inhabits the waters on one side common
to those of the other; but there can be no doubt that there would be a
considerable migration in both directions.
The fact stated in the report may suggest an important caution in drawing
conclusions upon the relative age of formations from the character of their
fossils. Had a geological movement or movements upheaved to different
levels the bottoms of waters thus separated by a narrow isthmus, and
dislocated the connection between those bottoms, naturalists, in after ages,
reasoning from the character of the fossil faunas, might have assigned them
to different, and perhaps very widely distant, periods.]
Page 759
Changes in the Caspian.
The Russian Government has contemplated the establishment of a nearly
direct water communication between the Caspian Sea and the Sea of Azoff,
partly by natural and partly by artificial channels, and there are now
navigable canals between the Don and the Volga; but these works, though
not wanting in commercial and political interest, do not possess any
geographical importance. It is, however, very possible to produce
appreciable geographical changes in the basin of the Caspian by the
diversion of the great rivers which flow from Central Russia. The surface of
the Caspian is eighty-three feet below the level of the Sea of Azoff, and its
depression has been explained upon the hypothesis that the evaporation
exceeds the supply derived, directly and indirectly, from precipitation,
though able physicists now maintain that the sinking of this sea is due to a
subsidence of its bottom from geological causes. At Tsaritsin, the Don,
which empties into the Sea of Azoff, and the Volga, which pours into the
Caspian, approach each other within ten miles. Near this point, by means of
open or subterranean canals, the Don might be turned into the Volga, or the
Volga into the Don. If we suppose the whole or a large proportion of the
waters of the Don to be thus diverted from their natural outlet and sent
down to the Caspian, the equilibrium between the evaporation from that sea
and its supply of water might be restored, or its level even raised above its
ancient limits. If the Volga were turned into the Sea of Azoff, the Caspian
would be reduced in dimensions until the balance between loss and gain
should be re-established, and it would occupy a much smaller area than at
present. Such changes in the proportion of solid and fluid surface would
have some climatic effects in the territory which drains into the Caspian,
and on the other hand, the introduction of a greater quantity of fresh water
into the Sea of Azoff would render that gulf less saline, affect the character
and numbers of its fish, and perhaps be not wholly without sensible
influence on the water of the Black Sea.
The Russian Government has contemplated the establishment of a nearly
direct water communication between the Caspian Sea and the Sea of Azoff,
partly by natural and partly by artificial channels, and there are now
navigable canals between the Don and the Volga; but these works, though
not wanting in commercial and political interest, do not possess any
geographical importance. It is, however, very possible to produce
appreciable geographical changes in the basin of the Caspian by the
diversion of the great rivers which flow from Central Russia. The surface of
the Caspian is eighty-three feet below the level of the Sea of Azoff, and its
depression has been explained upon the hypothesis that the evaporation
exceeds the supply derived, directly and indirectly, from precipitation,
though able physicists now maintain that the sinking of this sea is due to a
subsidence of its bottom from geological causes. At Tsaritsin, the Don,
which empties into the Sea of Azoff, and the Volga, which pours into the
Caspian, approach each other within ten miles. Near this point, by means of
open or subterranean canals, the Don might be turned into the Volga, or the
Volga into the Don. If we suppose the whole or a large proportion of the
waters of the Don to be thus diverted from their natural outlet and sent
down to the Caspian, the equilibrium between the evaporation from that sea
and its supply of water might be restored, or its level even raised above its
ancient limits. If the Volga were turned into the Sea of Azoff, the Caspian
would be reduced in dimensions until the balance between loss and gain
should be re-established, and it would occupy a much smaller area than at
present. Such changes in the proportion of solid and fluid surface would
have some climatic effects in the territory which drains into the Caspian,
and on the other hand, the introduction of a greater quantity of fresh water
into the Sea of Azoff would render that gulf less saline, affect the character
and numbers of its fish, and perhaps be not wholly without sensible
influence on the water of the Black Sea.
Page 760
Diversion of the Nile.
Perhaps the most remarkable project of great physical change, proposed
or threatened in earlier ages, is that of the diversion of the Nile from its
natural channel, and the turning of its current into either the Libyan Desert
or the Red Sea. The Ethiopian or Abyssinian princes more than once
menaced the Memlouk sultans with the execution of this alarming project,
and the fear of so serious an evil is said to have induced the Moslems to
conciliate the Abyssinian kings by large presents, and by some concessions
to the oppressed Christians of Egypt. Indeed, Arabian historians affirm that
in the tenth century the Ethiopians dammed the river, and, for a whole year,
cut off its waters from Egypt. [Footnote: "Some haue writte, that by certain
kings inhabiting aboue, the Nilus should there be stopped; & at a time
prefixt, let loose vpon a certaine tribute payd them by the Aegyptians. The
error springing perhaps fro a truth (as all wandring reports for the most part
doe) in that the Sultan doth pay a certaine annuall summe to the Abissin
Emperour for not diuerting the course of the Riuer, which (they say) he
may, or impouerish it at the least."—George Sandys, A Relation of a
Journey, etc., p. 98. See, also, Vansles, Voyage en Egypte, p. 61.] The
probable explanation of this story is to be found in a season of extreme
drought, such as have sometimes occurred in the valley of the Nile.
The Libyan Desert, above the junction of the two principal branches of
the Nile at Khartum, is so much higher than the level of the river below that
point, that there is no reason to believe a new channel for the united waters
of the two streams could be found in that direction; but the Bahr-el-Abiad
flows through, if it does not rise in, a great table-land, and some of its
tributaries are supposed to communicate in the rainy season with branches
of great rivers flowing in quite another direction. Hence it is probable that a
portion at least of the waters of this great arm of the Nile—and perhaps a
quantity the abstraction of which would be sensibly felt in Egypt—might be
Perhaps the most remarkable project of great physical change, proposed
or threatened in earlier ages, is that of the diversion of the Nile from its
natural channel, and the turning of its current into either the Libyan Desert
or the Red Sea. The Ethiopian or Abyssinian princes more than once
menaced the Memlouk sultans with the execution of this alarming project,
and the fear of so serious an evil is said to have induced the Moslems to
conciliate the Abyssinian kings by large presents, and by some concessions
to the oppressed Christians of Egypt. Indeed, Arabian historians affirm that
in the tenth century the Ethiopians dammed the river, and, for a whole year,
cut off its waters from Egypt. [Footnote: "Some haue writte, that by certain
kings inhabiting aboue, the Nilus should there be stopped; & at a time
prefixt, let loose vpon a certaine tribute payd them by the Aegyptians. The
error springing perhaps fro a truth (as all wandring reports for the most part
doe) in that the Sultan doth pay a certaine annuall summe to the Abissin
Emperour for not diuerting the course of the Riuer, which (they say) he
may, or impouerish it at the least."—George Sandys, A Relation of a
Journey, etc., p. 98. See, also, Vansles, Voyage en Egypte, p. 61.] The
probable explanation of this story is to be found in a season of extreme
drought, such as have sometimes occurred in the valley of the Nile.
The Libyan Desert, above the junction of the two principal branches of
the Nile at Khartum, is so much higher than the level of the river below that
point, that there is no reason to believe a new channel for the united waters
of the two streams could be found in that direction; but the Bahr-el-Abiad
flows through, if it does not rise in, a great table-land, and some of its
tributaries are supposed to communicate in the rainy season with branches
of great rivers flowing in quite another direction. Hence it is probable that a
portion at least of the waters of this great arm of the Nile—and perhaps a
quantity the abstraction of which would be sensibly felt in Egypt—might be
Page 761
sent to the Atlantic by the Congo or Niger, lost in inland lakes and marshes
in Central Africa, or employed to fertilize the Libyan sand wastes.
About the beginning of the sixteenth century, Albuquerque the "Terrible"
revived the scheme of turning the Nile into the Red Sea, with the hope of
destroying the transit trade through Egypt by way of Kosseir. In 1525 the
King of Portugal was requested by the Emperor of Abyssinia to send him
engineers for that purpose; a successor of that prince threatened to attempt
the project about the year 1700, and even as late as the French occupation
of Egypt, the possibility of driving out the intruder by this means was
suggested in England.
It cannot be positively affirmed that the diversion of the waters of the
Nile to the Red Sea is impossible. In the chain of mountains which
separates the two valleys, Brown found a deep depression or wadi,
extending from the one to the other, apparently at no great elevation above
the bed of the river, but the height of the summit level was not measured.
Admitting the possibility of turning the whole river into the Red Sea, let us
consider the probable effect of the change.
First and most obvious is the total destruction of the fertility of Middle
and Lower Egypt, the conversion of that part of the valley into a desert, and
the extinction of its imperfect civilization, if not the absolute extirpation of
its inhabitants. This is the calamity threatened by the Abyssinian princes
and the ferocious Portuguese warrior, and feared by the Sultans of Egypt.
Beyond these immediate and palpable consequences neither party then
looked; but a far wider geographical area, and far more extensive and
various human interests, would be affected by the measure. The spread of
the Nile during the annual inundation covers, for many weeks, several
thousand square miles with water, and at other seasons of the year pervades
the same and even a larger area with moisture by infiltration. The
in Central Africa, or employed to fertilize the Libyan sand wastes.
About the beginning of the sixteenth century, Albuquerque the "Terrible"
revived the scheme of turning the Nile into the Red Sea, with the hope of
destroying the transit trade through Egypt by way of Kosseir. In 1525 the
King of Portugal was requested by the Emperor of Abyssinia to send him
engineers for that purpose; a successor of that prince threatened to attempt
the project about the year 1700, and even as late as the French occupation
of Egypt, the possibility of driving out the intruder by this means was
suggested in England.
It cannot be positively affirmed that the diversion of the waters of the
Nile to the Red Sea is impossible. In the chain of mountains which
separates the two valleys, Brown found a deep depression or wadi,
extending from the one to the other, apparently at no great elevation above
the bed of the river, but the height of the summit level was not measured.
Admitting the possibility of turning the whole river into the Red Sea, let us
consider the probable effect of the change.
First and most obvious is the total destruction of the fertility of Middle
and Lower Egypt, the conversion of that part of the valley into a desert, and
the extinction of its imperfect civilization, if not the absolute extirpation of
its inhabitants. This is the calamity threatened by the Abyssinian princes
and the ferocious Portuguese warrior, and feared by the Sultans of Egypt.
Beyond these immediate and palpable consequences neither party then
looked; but a far wider geographical area, and far more extensive and
various human interests, would be affected by the measure. The spread of
the Nile during the annual inundation covers, for many weeks, several
thousand square miles with water, and at other seasons of the year pervades
the same and even a larger area with moisture by infiltration. The
Page 762
abstraction of so large an evaporating surface from the southern shores of
the Mediterranean could not but produce important effects on many
meteorological phenomena, and the humidity, the temperature, the electrical
condition and the atmospheric currents of North-eastern Africa might be
modified to a degree that would sensibly affect the climate of Europe.
The Mediterranean, deprived of the contributions of the Nile, would
require a larger supply, and of course a stronger current, of water from the
Atlantic through the Straits of Gibraltar; the proportion of salt it contains
would be increased, and the animal life of at least its southern borders
would be consequently modified; the current which winds along its
southern, eastern, and north-eastern shores would be diminished in force
and volume, if not destroyed altogether, and its basin and its harbors would
be shoaled by no new deposits from the highlands of inner Africa.
In the much smaller Red Sea, more immediately perceptible, if not
greater, effects, would be produced. The deposits of slime would reduce its
depth, and perhaps, in the course of ages, divide it into an inland and an
open sea, the former of which, receiving no supply from rivers, would, as in
the case of the northern part of the Gulf of California, soon be dried up by
evaporation, and its whole area added to the Africo-Arabian desert; the
waters of the latter would be more or less freshened, and their immensely
rich marine fauna and flora changed in character and proportion, and, near
the mouth of the river, perhaps even destroyed altogether; its navigable
channels would be altered in position and often quite obstructed; the flow of
its tides would be modified by the new geographical conditions; the
sediment of the river would form new coast-lines and lowlands, which
would be covered with vegetation, and probably thereby produce sensible
climatic changes.
Diversion of the Rhine.
the Mediterranean could not but produce important effects on many
meteorological phenomena, and the humidity, the temperature, the electrical
condition and the atmospheric currents of North-eastern Africa might be
modified to a degree that would sensibly affect the climate of Europe.
The Mediterranean, deprived of the contributions of the Nile, would
require a larger supply, and of course a stronger current, of water from the
Atlantic through the Straits of Gibraltar; the proportion of salt it contains
would be increased, and the animal life of at least its southern borders
would be consequently modified; the current which winds along its
southern, eastern, and north-eastern shores would be diminished in force
and volume, if not destroyed altogether, and its basin and its harbors would
be shoaled by no new deposits from the highlands of inner Africa.
In the much smaller Red Sea, more immediately perceptible, if not
greater, effects, would be produced. The deposits of slime would reduce its
depth, and perhaps, in the course of ages, divide it into an inland and an
open sea, the former of which, receiving no supply from rivers, would, as in
the case of the northern part of the Gulf of California, soon be dried up by
evaporation, and its whole area added to the Africo-Arabian desert; the
waters of the latter would be more or less freshened, and their immensely
rich marine fauna and flora changed in character and proportion, and, near
the mouth of the river, perhaps even destroyed altogether; its navigable
channels would be altered in position and often quite obstructed; the flow of
its tides would be modified by the new geographical conditions; the
sediment of the river would form new coast-lines and lowlands, which
would be covered with vegetation, and probably thereby produce sensible
climatic changes.
Diversion of the Rhine.
Page 763
The interference of physical improvements with vested rights and ancient
arrangements, is a more formidable obstacle in old countries than in new, to
enterprises involving anything approaching to a geographical revolution.
Hence such projects meet with stronger opposition in Europe than in
America, and the number of probable changes in the face of nature in the
former continent is proportionally less. I have noticed some important
hydraulic improvements as already executed or in progress in Europe, and I
may refer to some others as contemplated or suggested. One of these is the
diversion of the Rhine from its present channel below Ragatz, by a cut
through the narrow ridge near Sargans, and the consequent turning of its
current into the Lake of Wallenstadt. This would be an extremely easy
undertaking, for the ridge is but twenty feet above the level of the Rhine,
and hardly two hundred yards wide. There is no present adequate motive for
this diversion, but it is easy to suppose that it may become advisable within
no long period. The navigation of the Lake of Constance is rapidly
increasing in importance, and the shoaling of the eastern end of that lake by
the deposits of the Rhine may require a remedy which can be found by no
other so ready means as the discharge of that river into the Lake of
Wallenstadt. The navigation of this latter lake is not important, nor is it ever
likely to become so, because the rocky and precipitous character of its
shores renders their cultivation impossible. It is of great depth, and its basin
is capacious enough to receive and retain all the sediment which the Rhine
would carry into it for thousands of years. [Footnote: Many geographers
suppose that the dividing ridge between the Lake of Wallenstadt and the bed
of the Rhine at Sargans is a fluviatile deposit, which has closed a channel
through which the Rhine anciently discharged a part or the whole of its
waters into the lake. In the flood of 1868, the water of the Rhine rose to the
level of the railway station at Sargans, and for some days there was fear of
the giving way of the barrier and the diversion of the current of the river
into the lake.]
arrangements, is a more formidable obstacle in old countries than in new, to
enterprises involving anything approaching to a geographical revolution.
Hence such projects meet with stronger opposition in Europe than in
America, and the number of probable changes in the face of nature in the
former continent is proportionally less. I have noticed some important
hydraulic improvements as already executed or in progress in Europe, and I
may refer to some others as contemplated or suggested. One of these is the
diversion of the Rhine from its present channel below Ragatz, by a cut
through the narrow ridge near Sargans, and the consequent turning of its
current into the Lake of Wallenstadt. This would be an extremely easy
undertaking, for the ridge is but twenty feet above the level of the Rhine,
and hardly two hundred yards wide. There is no present adequate motive for
this diversion, but it is easy to suppose that it may become advisable within
no long period. The navigation of the Lake of Constance is rapidly
increasing in importance, and the shoaling of the eastern end of that lake by
the deposits of the Rhine may require a remedy which can be found by no
other so ready means as the discharge of that river into the Lake of
Wallenstadt. The navigation of this latter lake is not important, nor is it ever
likely to become so, because the rocky and precipitous character of its
shores renders their cultivation impossible. It is of great depth, and its basin
is capacious enough to receive and retain all the sediment which the Rhine
would carry into it for thousands of years. [Footnote: Many geographers
suppose that the dividing ridge between the Lake of Wallenstadt and the bed
of the Rhine at Sargans is a fluviatile deposit, which has closed a channel
through which the Rhine anciently discharged a part or the whole of its
waters into the lake. In the flood of 1868, the water of the Rhine rose to the
level of the railway station at Sargans, and for some days there was fear of
the giving way of the barrier and the diversion of the current of the river
into the lake.]
Page 764
Improvements in North American Hydrography.
We are not yet well enough acquainted with the geography of Central
Africa, or of the interior of South America, to conjecture what
hydrographical revolutions might there be wrought; but from the fact that
many important rivers in both continents drain extensive table-lands, of
moderate elevation and inclination, there is reason to suppose that important
changes in the course of those rivers might be accomplished. Our
knowledge of the drainage of North America is much more complete, and it
is certain that there are numerous points within our territory where the
courses of great rivers, or the discharge of considerable lakes, might be
completely diverted, or at least partially directed into different channels.
The surface of Lake Erie is 565 feet above that of the Hudson at Albany,
and it is so near the level of the great plain lying east of it, that it was found
practicable to supply the western section of the canal, which unites it with
the Hudson, with water from the lake, or rather from the Niagara which
flows out of it. The greatest depth of water yet sounded in Lake Erie is but
two hundred and seventy feet, the mean depth one hundred and twenty.
Open canals parallel with the Niagara, or directly towards the Genesee,
might be executed upon a scale which would exercise an important
influence on the drainage of the lake, if there were any adequate motive for
such an undertaking. Still easier would it be to enlarge the outlet for the
waters of Lake Superior at the Saut St. Mary—where the river which drains
the lake descends twenty-two feet in a single mile—and thus to produce
incalculable effects, both upon that lake and upon the great chain of inland
waters which communicate with it.
The summit level between the surface of Lake Michigan at its mean
height and that of the River Des Plaines, a tributary of the Illinois, at a point
some ten miles west of Chicago, is but ten and a half feet above the lake.
We are not yet well enough acquainted with the geography of Central
Africa, or of the interior of South America, to conjecture what
hydrographical revolutions might there be wrought; but from the fact that
many important rivers in both continents drain extensive table-lands, of
moderate elevation and inclination, there is reason to suppose that important
changes in the course of those rivers might be accomplished. Our
knowledge of the drainage of North America is much more complete, and it
is certain that there are numerous points within our territory where the
courses of great rivers, or the discharge of considerable lakes, might be
completely diverted, or at least partially directed into different channels.
The surface of Lake Erie is 565 feet above that of the Hudson at Albany,
and it is so near the level of the great plain lying east of it, that it was found
practicable to supply the western section of the canal, which unites it with
the Hudson, with water from the lake, or rather from the Niagara which
flows out of it. The greatest depth of water yet sounded in Lake Erie is but
two hundred and seventy feet, the mean depth one hundred and twenty.
Open canals parallel with the Niagara, or directly towards the Genesee,
might be executed upon a scale which would exercise an important
influence on the drainage of the lake, if there were any adequate motive for
such an undertaking. Still easier would it be to enlarge the outlet for the
waters of Lake Superior at the Saut St. Mary—where the river which drains
the lake descends twenty-two feet in a single mile—and thus to produce
incalculable effects, both upon that lake and upon the great chain of inland
waters which communicate with it.
The summit level between the surface of Lake Michigan at its mean
height and that of the River Des Plaines, a tributary of the Illinois, at a point
some ten miles west of Chicago, is but ten and a half feet above the lake.
Page 765
The lake once discharged a part or the whole of its waters into the valley of
the Des Plaines. A slight upheaval, at an unknown period, elevated the bed
of the Des Plaines, and the prairie between it and the lake, to their present
level, and the outflow of the lake was turned into a new direction. The bed
of the Des Plaines is higher than the surface of the lake, and in recent times
the Des Plaines, when at flood, has sent more or less of its waters across the
ridge into the bed of the South Branch of Chicago River, and so into Lake
Michigan.
A navigable channel has now been cut, admitting a constant flow of
water from the lake, by the valley of the Des Plaines, into the Illinois. The
mean discharge by this channel does not much exceed 23,000 cubic feet per
minute, but it would be quite practicable to enlarge its cross-section
indefinitely, and the flow through it might be so regulated as to keep the
Illinois and the Mississippi at flood at all seasons of the year. The increase
in the volume of these rivers would augment their velocity and their
transporting power, and, consequently, the erosion of their banks and the
deposit of slime in the Gulf of Mexico, while the opening of a
communication between the lake and the affluents of the Mississippi,
unobstructed except by locks, and the introduction of a large body of colder
water into the latter, would very probably produce a considerable effect on
the animal life that peoples them. The diversion of water from the common
basin of the great lakes through a new channel, in a direction opposite to
their present discharge, would not be absolutely without influence on the St.
Lawrence, though probably this effect might be too small to be readily
perceptible. [Footnote: From Reports of the Canal Commissioners of the
State of Illinois, and especially from a very interesting private letter from
William Gooding, Esq., an eminent engineer, which I regret I have not
space to print in full, I learn that the length of the present canal, from the
lake to the River Illinois, is 101 miles, with a total descent of a trifle more
than 145 feet, and that it is proposed to enlarge this channel to the width of
the Des Plaines. A slight upheaval, at an unknown period, elevated the bed
of the Des Plaines, and the prairie between it and the lake, to their present
level, and the outflow of the lake was turned into a new direction. The bed
of the Des Plaines is higher than the surface of the lake, and in recent times
the Des Plaines, when at flood, has sent more or less of its waters across the
ridge into the bed of the South Branch of Chicago River, and so into Lake
Michigan.
A navigable channel has now been cut, admitting a constant flow of
water from the lake, by the valley of the Des Plaines, into the Illinois. The
mean discharge by this channel does not much exceed 23,000 cubic feet per
minute, but it would be quite practicable to enlarge its cross-section
indefinitely, and the flow through it might be so regulated as to keep the
Illinois and the Mississippi at flood at all seasons of the year. The increase
in the volume of these rivers would augment their velocity and their
transporting power, and, consequently, the erosion of their banks and the
deposit of slime in the Gulf of Mexico, while the opening of a
communication between the lake and the affluents of the Mississippi,
unobstructed except by locks, and the introduction of a large body of colder
water into the latter, would very probably produce a considerable effect on
the animal life that peoples them. The diversion of water from the common
basin of the great lakes through a new channel, in a direction opposite to
their present discharge, would not be absolutely without influence on the St.
Lawrence, though probably this effect might be too small to be readily
perceptible. [Footnote: From Reports of the Canal Commissioners of the
State of Illinois, and especially from a very interesting private letter from
William Gooding, Esq., an eminent engineer, which I regret I have not
space to print in full, I learn that the length of the present canal, from the
lake to the River Illinois, is 101 miles, with a total descent of a trifle more
than 145 feet, and that it is proposed to enlarge this channel to the width of
Page 766
one hundred and sixty feet, with a minimum depth of seven, and to create a
slack-water navigation in the Illinois by the construction of five dams, one
of which is already completed. The descent for the outlet of the canal at La
Salle on the Illinois to the Mississippi is twenty-eight feet, the distance
being 230 miles. The canal thus enlarged would cost about $16,000,000,
and it would establish a navigation for vessels of 1,200 to 1,500 tons burden
between Lake Michigan and the Mississippi, and consequently, by means of
the great lakes and the Welland canal, between the St. Lawrence and the
Gulf of Mexico.]
In an able and interesting article in a California magazine, Dr. Widney
has suggested a probable cause and a possible remedy for the desiccation of
south-eastern California referred to in a former chapter. The Colorado
Desert which lies considerably below the level of the waters of the Gulf of
California, and has an area of about 4,000 square miles, evidently once
formed a part of that gulf. This northern extension of the gulf appears to
have been cut off from the main body by deposits brought down by the
great river Colorado, at no very distant period. These deposits at the same
time turned the course of the river to the south, and it now enters the gulf at
a point twenty miles distant from its original outlet.
When this northern arm of the gulf was cut off from the sea, and the river
which once discharged itself into it was diverted, it was speedily laid dry by
evaporation, and now yields no vapor to be condensed into fog, rain, and
snow on the neighboring mountains, which are now parched and almost
bare of vegetation.
The ancient bed of the river may still be traced, and in floods the
Colorado still sends a part of its overflowing supply into its old channel,
and for a time waters a portion of the desert. It is believed that the river
might easily be turned back into its original course, and indeed nature
slack-water navigation in the Illinois by the construction of five dams, one
of which is already completed. The descent for the outlet of the canal at La
Salle on the Illinois to the Mississippi is twenty-eight feet, the distance
being 230 miles. The canal thus enlarged would cost about $16,000,000,
and it would establish a navigation for vessels of 1,200 to 1,500 tons burden
between Lake Michigan and the Mississippi, and consequently, by means of
the great lakes and the Welland canal, between the St. Lawrence and the
Gulf of Mexico.]
In an able and interesting article in a California magazine, Dr. Widney
has suggested a probable cause and a possible remedy for the desiccation of
south-eastern California referred to in a former chapter. The Colorado
Desert which lies considerably below the level of the waters of the Gulf of
California, and has an area of about 4,000 square miles, evidently once
formed a part of that gulf. This northern extension of the gulf appears to
have been cut off from the main body by deposits brought down by the
great river Colorado, at no very distant period. These deposits at the same
time turned the course of the river to the south, and it now enters the gulf at
a point twenty miles distant from its original outlet.
When this northern arm of the gulf was cut off from the sea, and the river
which once discharged itself into it was diverted, it was speedily laid dry by
evaporation, and now yields no vapor to be condensed into fog, rain, and
snow on the neighboring mountains, which are now parched and almost
bare of vegetation.
The ancient bed of the river may still be traced, and in floods the
Colorado still sends a part of its overflowing supply into its old channel,
and for a time waters a portion of the desert. It is believed that the river
might easily be turned back into its original course, and indeed nature
Page 767
herself seems to be now tending, by various spontaneous processes, to
accomplish that object. The waters of the Colorado, though perhaps not
sufficient to fill the basin and keep it at the sea-level in spite of the rapid
evaporation in that climate, [Footnote: The thermometer sometimes rises to
120 degrees F. at Fort Yuma, at the S. E. angle of California in N. L. 33
degrees.] would at least create a permanent lake in the lower part of the
depression, the evaporation from which, Dr. Widney suggests, might
sensibly increase the humidity and lower the temperature of an extensive
region which is now an arid and desolate wilderness.
Soil below Rock.
One of the most singular changes of natural surface effected by man is
that observed by Beechey and by Barth at Lin Tefla, and near Gebel
Genunes, in the district of Ben Gasi, in Northern Africa. In this region the
superficial stratum originally consisted of a thin sheet of rock covering a
layer of fertile earth. This rock has been broken up, and, when not
practicable to find use for it in fences, fortresses, or dwellings, heaped
together in high piles, and the soil, thus bared of its stony shell, has been
employed for agricultural purposes. [Footnote: Barth, Wanderungen durch
die Kusten des Mittelmeeres, i., p. 853. In a note on page 380, of the same
volume, Barth cites Strabo as asserting that a similar practice prevailed in
Iapygia; but the epithet [word in Greek: traxeia], applied by Strabo to the
original surface, does not neceasarily imply that it was covered with a
continuous stratum of rock.] If we remember that gunpowder was unknown
at the period when these remarkable improvements were executed, and of
course that the rock could have been broken only with the chisel and
wedge, we must infer that land had at that time a very great pecuniary
value, and, of course, that the province, though now exhausted, and almost
entirely deserted by man, had once a dense population.
accomplish that object. The waters of the Colorado, though perhaps not
sufficient to fill the basin and keep it at the sea-level in spite of the rapid
evaporation in that climate, [Footnote: The thermometer sometimes rises to
120 degrees F. at Fort Yuma, at the S. E. angle of California in N. L. 33
degrees.] would at least create a permanent lake in the lower part of the
depression, the evaporation from which, Dr. Widney suggests, might
sensibly increase the humidity and lower the temperature of an extensive
region which is now an arid and desolate wilderness.
Soil below Rock.
One of the most singular changes of natural surface effected by man is
that observed by Beechey and by Barth at Lin Tefla, and near Gebel
Genunes, in the district of Ben Gasi, in Northern Africa. In this region the
superficial stratum originally consisted of a thin sheet of rock covering a
layer of fertile earth. This rock has been broken up, and, when not
practicable to find use for it in fences, fortresses, or dwellings, heaped
together in high piles, and the soil, thus bared of its stony shell, has been
employed for agricultural purposes. [Footnote: Barth, Wanderungen durch
die Kusten des Mittelmeeres, i., p. 853. In a note on page 380, of the same
volume, Barth cites Strabo as asserting that a similar practice prevailed in
Iapygia; but the epithet [word in Greek: traxeia], applied by Strabo to the
original surface, does not neceasarily imply that it was covered with a
continuous stratum of rock.] If we remember that gunpowder was unknown
at the period when these remarkable improvements were executed, and of
course that the rock could have been broken only with the chisel and
wedge, we must infer that land had at that time a very great pecuniary
value, and, of course, that the province, though now exhausted, and almost
entirely deserted by man, had once a dense population.
Page 768
Covering Rock with Earth.
If man has, in some cases, broken up rock to reach productive ground
beneath, he has, in many other instances, covered bare ledges, and
sometimes extensive surfaces of solid stone, with fruitful earth, brought
from no inconsiderable distance. Not to speak of the Campo Santo at Pisa,
filled, or at least coated, with earth from the Holy Land, for quite a different
purpose, it is affirmed that the garden of the monastery of St. Catherine at
Mount Sinai is composed of Nile mud, transported on the backs of camels
from the banks of that river. Parthey and older authors state that all the
productive soil of the Island of Malta was brought over from Sicily.
[Footnote: Parthey, Wanderungen durch Sicilen und die Levante, i., p. 404.]
The accuracy of the information may be questioned in both cases, but
similar practices, on a smaller scale, are matter of daily observation in many
parts of Southern Europe. Much of the wine of the Moselle is derived from
grapes grown on earth carried high up the cliffs on the shoulders of men,
and the steep terraced slopes of the Island of Teneriffe are covered with soil
painfully scooped out from fissures in and between the rocks which have
been laid bare by the destruction of the native forests. [Footnote:
Mantegazza, Rio de la Plata e Teneriffa, p. 567.] In China, too, rock has
been artificially covered with earth to an extent which gives such operations
a real geographical importance, and the accounts of the importation of earth
at Malta, and the fertilization of the rocks on Mount Sinai with slime from
the Nile, may be not wholly without foundation.
Valleys in Deserts.
In the latter case, indeed, river sediment might be very useful as a
manure, but it could hardly be needed as a soil; for the growth of vegetation
in the wadies of the Sinaitic Peninsula shows that the disintegrated rock of
its mountains requires only water to stimulate it to considerable
If man has, in some cases, broken up rock to reach productive ground
beneath, he has, in many other instances, covered bare ledges, and
sometimes extensive surfaces of solid stone, with fruitful earth, brought
from no inconsiderable distance. Not to speak of the Campo Santo at Pisa,
filled, or at least coated, with earth from the Holy Land, for quite a different
purpose, it is affirmed that the garden of the monastery of St. Catherine at
Mount Sinai is composed of Nile mud, transported on the backs of camels
from the banks of that river. Parthey and older authors state that all the
productive soil of the Island of Malta was brought over from Sicily.
[Footnote: Parthey, Wanderungen durch Sicilen und die Levante, i., p. 404.]
The accuracy of the information may be questioned in both cases, but
similar practices, on a smaller scale, are matter of daily observation in many
parts of Southern Europe. Much of the wine of the Moselle is derived from
grapes grown on earth carried high up the cliffs on the shoulders of men,
and the steep terraced slopes of the Island of Teneriffe are covered with soil
painfully scooped out from fissures in and between the rocks which have
been laid bare by the destruction of the native forests. [Footnote:
Mantegazza, Rio de la Plata e Teneriffa, p. 567.] In China, too, rock has
been artificially covered with earth to an extent which gives such operations
a real geographical importance, and the accounts of the importation of earth
at Malta, and the fertilization of the rocks on Mount Sinai with slime from
the Nile, may be not wholly without foundation.
Valleys in Deserts.
In the latter case, indeed, river sediment might be very useful as a
manure, but it could hardly be needed as a soil; for the growth of vegetation
in the wadies of the Sinaitic Peninsula shows that the disintegrated rock of
its mountains requires only water to stimulate it to considerable
Page 769
productiveness. The wadies present, not unfrequently, narrow gorges, which
might easily be closed, and thus accumulations of earth, and reservoirs of
water to irrigate it, might be formed which would convert many a square
mile of desert into flourishing date gardens and cornfields. For example, not
far from Wadi Feiran, on the most direct route to Wadi Esh-Sheikh, is a very
narrow pass called by the Arabs El Bueb (El Bab) or, The Gate, which
might be securely closed to a very considerable height, with little labor or
expense. Above this pass is a wide and nearly level expanse, filled up to a
certain regular level with deposits brought down by torrents before the
Gate, or Bueb, was broken through, and they have now worn down a
channel in the deposits to the bed of the wadi. If a dam were constructed at
the pass, and reservoirs built to retain the winter rains, a great extent of
valley might be rendered cultivable.
Effects of Mining.
The excavations made by man, for mining and other purposes, may
occasion disturbance of the surface by the subsidence of the strata above
them, as in the case of the mine of Fahlun, in Sweden, but such accidents
have generally been too inconsiderable in extent to deserve notice in a
geographical point of view. [Footnote: In March, 1873, the imprudent
extension of the excavations in a slate mine near Morzine, in Savoy,
occasioned the fall of a mass of rock measuring more than 700,000 yards in
cubical contents. A forest of firs was destroyed, and a hamlet of twelve
houses crushed and buried by the slide.] It is said, however, that in many
places in the mining regions of England alarming indications of a tendency
to a wide dislocation of the superficial strata have manifested themselves.
Indeed, when we consider the measure of the underground cavities which
miners have excavated, we cannot but be surprised that grave catastrophes
have not often resulted from the removal of the foundations on which the
might easily be closed, and thus accumulations of earth, and reservoirs of
water to irrigate it, might be formed which would convert many a square
mile of desert into flourishing date gardens and cornfields. For example, not
far from Wadi Feiran, on the most direct route to Wadi Esh-Sheikh, is a very
narrow pass called by the Arabs El Bueb (El Bab) or, The Gate, which
might be securely closed to a very considerable height, with little labor or
expense. Above this pass is a wide and nearly level expanse, filled up to a
certain regular level with deposits brought down by torrents before the
Gate, or Bueb, was broken through, and they have now worn down a
channel in the deposits to the bed of the wadi. If a dam were constructed at
the pass, and reservoirs built to retain the winter rains, a great extent of
valley might be rendered cultivable.
Effects of Mining.
The excavations made by man, for mining and other purposes, may
occasion disturbance of the surface by the subsidence of the strata above
them, as in the case of the mine of Fahlun, in Sweden, but such accidents
have generally been too inconsiderable in extent to deserve notice in a
geographical point of view. [Footnote: In March, 1873, the imprudent
extension of the excavations in a slate mine near Morzine, in Savoy,
occasioned the fall of a mass of rock measuring more than 700,000 yards in
cubical contents. A forest of firs was destroyed, and a hamlet of twelve
houses crushed and buried by the slide.] It is said, however, that in many
places in the mining regions of England alarming indications of a tendency
to a wide dislocation of the superficial strata have manifested themselves.
Indeed, when we consider the measure of the underground cavities which
miners have excavated, we cannot but be surprised that grave catastrophes
have not often resulted from the removal of the foundations on which the
Page 770
crust of our earth is laid. The 100,000,000 tons of coal yearly extracted
from British mines require the withdrawal of subterranean strata equal to an
area of 20,000 acres one yard deep, or 2,000 acres ten yards deep. These
excavations have gone on for several years at this rate, and in smaller
proportions for centuries. Hence, it cannot be doubted that by these and
other like operations the earth has been undermined and honey-combed in
many countries to an extent that may well excite serious apprehensions as
to the stability of the surface. In any event such excavations may interfere
materially with the course of subterranean waters, and it has even been
conjectured that the removal of large bodies of metallic ore from their
original deposits might, at least locally, affect in a sensible degree the
magnetic and electrical condition of the earth's crust. [Footnote: The
exhaustion of the more accessible deposits of coal and other minerals has
compelled the miners in Belgium, England, and other countries, to carry
their operations to great depths below the surface. At the colliery Des
Viviers, at Cilly near Charleroi, in Belgium, coal is worked at the depth of
2,820 feet, and one pit has been sunk to the depth of 3,411 feet. It is
supposed that the internal heat of the earth will render mining impossible
below 4,000 feet. At Clifford Amalgamated Mines, in Cornwall, the
temperature at 1,590 feet stood at 100 degrees, but after the shaft had
remained a year open it fell to 83 degrees. In another Cornish mine men
work at from 110 degrees to 120 degrees, but only twenty minutes at a time,
and with cold water thrown frequently over them.—The last Thirty Years in
Mining Districts, p. 95.
Stopponi mentions an abandoned mine at Huttenberg, in Bohemia, of the
depth of 3,775 feet.—Corso di Geologia, i., p. 258.]
Hydraulic Mining.
from British mines require the withdrawal of subterranean strata equal to an
area of 20,000 acres one yard deep, or 2,000 acres ten yards deep. These
excavations have gone on for several years at this rate, and in smaller
proportions for centuries. Hence, it cannot be doubted that by these and
other like operations the earth has been undermined and honey-combed in
many countries to an extent that may well excite serious apprehensions as
to the stability of the surface. In any event such excavations may interfere
materially with the course of subterranean waters, and it has even been
conjectured that the removal of large bodies of metallic ore from their
original deposits might, at least locally, affect in a sensible degree the
magnetic and electrical condition of the earth's crust. [Footnote: The
exhaustion of the more accessible deposits of coal and other minerals has
compelled the miners in Belgium, England, and other countries, to carry
their operations to great depths below the surface. At the colliery Des
Viviers, at Cilly near Charleroi, in Belgium, coal is worked at the depth of
2,820 feet, and one pit has been sunk to the depth of 3,411 feet. It is
supposed that the internal heat of the earth will render mining impossible
below 4,000 feet. At Clifford Amalgamated Mines, in Cornwall, the
temperature at 1,590 feet stood at 100 degrees, but after the shaft had
remained a year open it fell to 83 degrees. In another Cornish mine men
work at from 110 degrees to 120 degrees, but only twenty minutes at a time,
and with cold water thrown frequently over them.—The last Thirty Years in
Mining Districts, p. 95.
Stopponi mentions an abandoned mine at Huttenberg, in Bohemia, of the
depth of 3,775 feet.—Corso di Geologia, i., p. 258.]
Hydraulic Mining.
Page 771
What is called hydraulic mining—a system substantially identical with
that described in an interesting way by Pliny the elder, in Book XXXV. of
his Natural History, as practised in his time in the gold mines of Spain
[Footnote: I have little doubt that the hydraulic mining in Gaul, alluded to
by Diodorus Siculus, Bibliotheca Historica, v. 27, as merely a mode of
utilizing the effects of water flowing in its natural channels, was really the
artificial method described by Pliny.]—is producing important geographical
effects in California. Artificially directed currents of water have been long
employed for washing down and removing masses of earth, but in the
Californian mining the process is resorted to on a vastly greater scale than
in any other modern engineering operations, and with results proportioned
to the means. Brooks of considerable volume are diverted from their natural
channels and conducted to great distances in canals or wooden aqueducts,
[Footnote: In 1867 there were 6,000 miles (including branches) of artificial
water-courses employed for mining purposes in California. The flumes of
these canals are often of sheet-iron, and in some places are carried
considerable distances at a height of 250 feet above the ground.—
Raymond, Mineral Statistics west of the Rocky Mountains, 1870, p. 476.]
and then directed against hills and large level surfaces of ground which it is
necessary to remove to reach the gold-bearing strata, or which themselves
contain deposits of the precious mineral. [Footnote: The water is sometimes
driven through iron tubes under a hydrostatic pressure of several hundred
feet, with a force which cuts away rock of considerable solidity almost as
easily as hard earth. In this way of using water, the cutting force might,
doubtless, be greatly augmented by introducing sand or gravel into the
current.] Naked hills and fertile soils are alike washed away by the artificial
torrent, and the material removed—vegetable mould, sand, gravel, pebbles
—is carried down by the current and often spread over ground lying quite
out of the reach of natural inundations, and burying it to the depth
sometimes of twenty-five feet. An orchard valued at $60,000, and another
that described in an interesting way by Pliny the elder, in Book XXXV. of
his Natural History, as practised in his time in the gold mines of Spain
[Footnote: I have little doubt that the hydraulic mining in Gaul, alluded to
by Diodorus Siculus, Bibliotheca Historica, v. 27, as merely a mode of
utilizing the effects of water flowing in its natural channels, was really the
artificial method described by Pliny.]—is producing important geographical
effects in California. Artificially directed currents of water have been long
employed for washing down and removing masses of earth, but in the
Californian mining the process is resorted to on a vastly greater scale than
in any other modern engineering operations, and with results proportioned
to the means. Brooks of considerable volume are diverted from their natural
channels and conducted to great distances in canals or wooden aqueducts,
[Footnote: In 1867 there were 6,000 miles (including branches) of artificial
water-courses employed for mining purposes in California. The flumes of
these canals are often of sheet-iron, and in some places are carried
considerable distances at a height of 250 feet above the ground.—
Raymond, Mineral Statistics west of the Rocky Mountains, 1870, p. 476.]
and then directed against hills and large level surfaces of ground which it is
necessary to remove to reach the gold-bearing strata, or which themselves
contain deposits of the precious mineral. [Footnote: The water is sometimes
driven through iron tubes under a hydrostatic pressure of several hundred
feet, with a force which cuts away rock of considerable solidity almost as
easily as hard earth. In this way of using water, the cutting force might,
doubtless, be greatly augmented by introducing sand or gravel into the
current.] Naked hills and fertile soils are alike washed away by the artificial
torrent, and the material removed—vegetable mould, sand, gravel, pebbles
—is carried down by the current and often spread over ground lying quite
out of the reach of natural inundations, and burying it to the depth
sometimes of twenty-five feet. An orchard valued at $60,000, and another
Page 772
estimated at not less than $200,000, are stated to have been thus sacrificed,
and a report from the Agricultural Bureau at Washington computes the
annual damage done by this mode of mining at the incredible sum of
$12,000,000.
Accidental fires in mines of coal or lignite sometimes lead to
consequences not only destructive to large quantities of valuable material,
but which may, directly or indirectly, produce results important in
geography. The coal is occasionally ignited by the miners' lights or other
fires used by them, and certain kinds of this mineral, if long exposed to air
in deserted galleries, may be spontaneously kindled. Under favorable
circumstances, a stratum of coal will burn until it is exhausted, and a cavity
may be burnt out in a few months which human labor could not excavate in
many years. Wittwer informs us that a coal mine at St. Etienne in Dauphiny
has been burning ever since the fourteenth century, and that a mine near
Duttweiler, another near Epterode, and a third at Zwickau, have been on fire
for two hundred years. Such conflagrations not only produce cavities in the
earth, but communicate a perceptible degree of heat to the surface, and the
author just quoted cites cases where this heat has ben advantageously
employed in forcing vegetation.
Projects of Agricultural Improvements by Duponchel.
Duponchel's schemes of agricultural improvement are so grandiose in
their nature, so vast in their sphere of operation, and so important in their
possible effects upon immense tracts of the earth's surface, that they must
be considered as projects of geographical revolution, and they therefore
merit more than a passing notice. In a memoir already quoted, and in a later
work, [Footnote: Traite d'Hydraulique et de Geologie Agricole, 1868.] this
engineer proposes to construct artificial torrents for the purpose of grinding
up calcareous rock, by rolling and attrition along their beds, and thus
and a report from the Agricultural Bureau at Washington computes the
annual damage done by this mode of mining at the incredible sum of
$12,000,000.
Accidental fires in mines of coal or lignite sometimes lead to
consequences not only destructive to large quantities of valuable material,
but which may, directly or indirectly, produce results important in
geography. The coal is occasionally ignited by the miners' lights or other
fires used by them, and certain kinds of this mineral, if long exposed to air
in deserted galleries, may be spontaneously kindled. Under favorable
circumstances, a stratum of coal will burn until it is exhausted, and a cavity
may be burnt out in a few months which human labor could not excavate in
many years. Wittwer informs us that a coal mine at St. Etienne in Dauphiny
has been burning ever since the fourteenth century, and that a mine near
Duttweiler, another near Epterode, and a third at Zwickau, have been on fire
for two hundred years. Such conflagrations not only produce cavities in the
earth, but communicate a perceptible degree of heat to the surface, and the
author just quoted cites cases where this heat has ben advantageously
employed in forcing vegetation.
Projects of Agricultural Improvements by Duponchel.
Duponchel's schemes of agricultural improvement are so grandiose in
their nature, so vast in their sphere of operation, and so important in their
possible effects upon immense tracts of the earth's surface, that they must
be considered as projects of geographical revolution, and they therefore
merit more than a passing notice. In a memoir already quoted, and in a later
work, [Footnote: Traite d'Hydraulique et de Geologie Agricole, 1868.] this
engineer proposes to construct artificial torrents for the purpose of grinding
up calcareous rock, by rolling and attrition along their beds, and thus
Page 773
reducing it into a fine slime; and at the same time these torrents are to
transport an argillaceous deposit which is to be mingled with the calcareous
slime, and distributed over the Landes by watercourses constructed for the
purpose. By this means, he supposes that a very fertile soil may be formed,
and so graded in depositing as to secure for it a good drainage.
In order that nothing may be wanting to recommend the project,
Duponchel suggests that, as some rivers of Western France are gold-
bearing, it is probable that gold enough may be collected by washing the
sands to reduce materially the expense of such operations.
In the Landes of Gascony alone, he believes that 3,000,000 acres, now
barren, might be made productive at a moderate expense, and that similar
methods might be advantageously employed in France over an extent of not
less than 30,000,000 acres now almost wholly valueless.
The successful execution of the plan would increase the fertile territory
of France by an area of four or five times the extent of Sicily or of Sardinia.
There seems to be no reason why the same method, applied for such
different purposes, should necessarily be destructive in the one case while it
is so advantageous in the other. A wiser economy might bring about a
harmony of action between the miners and the agriculturists of California,
and the soil which is removed by the former as an incumbrance, judiciously
deposited, might become for the latter a source of wealth more solid and
enduring than the gold now obtained by such a sacrifice of agricultural
interests.
Action of Man on the Weather.
transport an argillaceous deposit which is to be mingled with the calcareous
slime, and distributed over the Landes by watercourses constructed for the
purpose. By this means, he supposes that a very fertile soil may be formed,
and so graded in depositing as to secure for it a good drainage.
In order that nothing may be wanting to recommend the project,
Duponchel suggests that, as some rivers of Western France are gold-
bearing, it is probable that gold enough may be collected by washing the
sands to reduce materially the expense of such operations.
In the Landes of Gascony alone, he believes that 3,000,000 acres, now
barren, might be made productive at a moderate expense, and that similar
methods might be advantageously employed in France over an extent of not
less than 30,000,000 acres now almost wholly valueless.
The successful execution of the plan would increase the fertile territory
of France by an area of four or five times the extent of Sicily or of Sardinia.
There seems to be no reason why the same method, applied for such
different purposes, should necessarily be destructive in the one case while it
is so advantageous in the other. A wiser economy might bring about a
harmony of action between the miners and the agriculturists of California,
and the soil which is removed by the former as an incumbrance, judiciously
deposited, might become for the latter a source of wealth more solid and
enduring than the gold now obtained by such a sacrifice of agricultural
interests.
Action of Man on the Weather.
Page 774
Espy's well-known suggestion of the possibility of causing rain
artificially, by kindling great fires, is not likely to be turned to practical
account, but the speculations of this able meteorologist are not, for that
reason, to be rejected as worthless. His labors exhibit great industry in the
collection of facts, much ingenuity in dealing with them, remarkable insight
into the laws of nature, and a ready perception of analogies and relations
not obvious to minds less philosophically constituted. They have
unquestionably contributed essentially to the advancement of
meteorological science.
The possibility that the distribution and action of electricity may be
considerably modified by long lines of iron railways and telegraph wires, is
a kindred thought, and in fact rests much on the same foundation as the
belief in the utility of lightning-rods, but such influence is too obscure and
too uncertain to have been yet demonstrated, though many intelligent
observers believe that sensible meteorological effects have been produced
by it.
It is affirmed that battles and heavy cannonades are generally followed
by rain and thunder-storms, and Powers has collected much evidence on
this subject, [Footnote: War and the Weather, or the Artificial Production of
Rain, Chicago, 1871. Paifer proposed, as early as 1814, arrangements for
producing rain by firing cannon and exploding shells in the air. Ein
wunderbarer Traum die Frucht, barkeit durch willkurlichen Regen zu
befordern, Metz, 1814. See, on the question of the possibility of influencing
the weather by artificial means, London Quarterly Journal of Science, xxix.,
p. 126, and Nature, Feb. 16, 1871, p. 306.] but the proposition does not
seem to be by any means established.
Resistance to Great Natural Forces.
artificially, by kindling great fires, is not likely to be turned to practical
account, but the speculations of this able meteorologist are not, for that
reason, to be rejected as worthless. His labors exhibit great industry in the
collection of facts, much ingenuity in dealing with them, remarkable insight
into the laws of nature, and a ready perception of analogies and relations
not obvious to minds less philosophically constituted. They have
unquestionably contributed essentially to the advancement of
meteorological science.
The possibility that the distribution and action of electricity may be
considerably modified by long lines of iron railways and telegraph wires, is
a kindred thought, and in fact rests much on the same foundation as the
belief in the utility of lightning-rods, but such influence is too obscure and
too uncertain to have been yet demonstrated, though many intelligent
observers believe that sensible meteorological effects have been produced
by it.
It is affirmed that battles and heavy cannonades are generally followed
by rain and thunder-storms, and Powers has collected much evidence on
this subject, [Footnote: War and the Weather, or the Artificial Production of
Rain, Chicago, 1871. Paifer proposed, as early as 1814, arrangements for
producing rain by firing cannon and exploding shells in the air. Ein
wunderbarer Traum die Frucht, barkeit durch willkurlichen Regen zu
befordern, Metz, 1814. See, on the question of the possibility of influencing
the weather by artificial means, London Quarterly Journal of Science, xxix.,
p. 126, and Nature, Feb. 16, 1871, p. 306.] but the proposition does not
seem to be by any means established.
Resistance to Great Natural Forces.
Page 775
I have often spoken of the greater and more subtile natural forces, and
especially of geological agencies, as powers beyond human guidance or
resistance. This is no doubt at present true in the main, but man has shown
that he is not altogether impotent to struggle with even these mighty
servants of nature, and his unconscious as well as his deliberate action may
in some cases have increased or diminished the intensity of their energies. It
is a very ancient belief that earthquakes are more destructive in districts
where the crust of the earth is solid and homogeneous, than where it is of a
looser and more interrupted structure. Aristotle, Pliny the elder, and Seneca
believed that not only natural ravines and caves, but quarries, wells, and
other human excavations, which break the continuity of the terrestrial strata
and facilitate the escape of elastic vapors, have a sensible influence in
diminishing the violence and preventing the propagation of the earth-waves.
In all countries subject to earthquakes this opinion is still maintained, and it
is asserted that, both in ancient and in modern times, buildings protected by
deep wells under or near them have suffered less from earthquakes than
those the architects of which have neglected this precaution. [Footnote:
Landgrebe, Geschichte der Vulkane, ii., pp. 19, 20.]
If the commonly received theory of the cause of earthquakes is true—
that, namely, which ascribes them to the elastic force of gases accumulated
or generated in subterranean reservoirs—it is evident that open channels of
communication between such reservoirs and the atmosphere might serve as
a harmless discharge of gases that would otherwise acquire destructive
energy. The doubt is whether artificial excavations can be carried deep
enough to reach the laboratory where the elastic fluids are distilled. There
are, in many places, small natural crevices through which such fluids
escape, and the source of them sometimes lies at so moderate a depth that
they pervade the superficial soil and, as it were, transpire from it, over a
considerable area. When the borer of an ordinary artesian well strikes into a
cavity in the earth, imprisoned air often rushes out with great violence, and
especially of geological agencies, as powers beyond human guidance or
resistance. This is no doubt at present true in the main, but man has shown
that he is not altogether impotent to struggle with even these mighty
servants of nature, and his unconscious as well as his deliberate action may
in some cases have increased or diminished the intensity of their energies. It
is a very ancient belief that earthquakes are more destructive in districts
where the crust of the earth is solid and homogeneous, than where it is of a
looser and more interrupted structure. Aristotle, Pliny the elder, and Seneca
believed that not only natural ravines and caves, but quarries, wells, and
other human excavations, which break the continuity of the terrestrial strata
and facilitate the escape of elastic vapors, have a sensible influence in
diminishing the violence and preventing the propagation of the earth-waves.
In all countries subject to earthquakes this opinion is still maintained, and it
is asserted that, both in ancient and in modern times, buildings protected by
deep wells under or near them have suffered less from earthquakes than
those the architects of which have neglected this precaution. [Footnote:
Landgrebe, Geschichte der Vulkane, ii., pp. 19, 20.]
If the commonly received theory of the cause of earthquakes is true—
that, namely, which ascribes them to the elastic force of gases accumulated
or generated in subterranean reservoirs—it is evident that open channels of
communication between such reservoirs and the atmosphere might serve as
a harmless discharge of gases that would otherwise acquire destructive
energy. The doubt is whether artificial excavations can be carried deep
enough to reach the laboratory where the elastic fluids are distilled. There
are, in many places, small natural crevices through which such fluids
escape, and the source of them sometimes lies at so moderate a depth that
they pervade the superficial soil and, as it were, transpire from it, over a
considerable area. When the borer of an ordinary artesian well strikes into a
cavity in the earth, imprisoned air often rushes out with great violence, and
Page 776
this has been still more frequently observed, in sinking mineral-oil wells. In
this latter case, the discharge of a vehement current of inflammable fluid
sometimes continues for hours and even longer periods. These facts seem to
render it not wholly improbable that the popular belief of the efficacy of
deep wells in mitigating the violence of earthquakes is well founded.
In general, light, wooden buildings are less injured by earthquakes than
more solid structures of stone or brick, and it is commonly supposed that
the power put forth by the earth-wave is too great to be resisted by any
amount of weight or solidity of mass that man can pile up upon the surface.
But the fact that in countries subject to earthquakes many very large and
strongly constructed palaces, temples, and other monuments have stood for
centuries, comparatively uninjured, suggests a doubt whether this opinion is
sound. The earthquake of the first of November, 1755, which is asserted,
though upon doubtful evidence, to have been felt over a twelfth part of the
earth's surface, was among the most violent of which we have any clear and
distinct account, and it seems to have exerted its most destructive force at
Lisbon. It has often been noticed as a remarkable fact, that the mint, a
building of great solidity, was almost wholly unaffected by the shock which
shattered every house and church in the city, and its escape from the
common ruin can hardly be accounted for except upon the supposition that
its weight, compactness, and strength of material enabled it to resist an
agitation of the earth which overthrew all weaker structures. On the other
hand, a stone pier in the harbor of Lisbon, on which thousands of people
had taken refuge, sank with its foundations to a great depth during the same
earthquake; and it is plain that where subterranean cavities exist, at
moderate depths, the erection of heavy masses upon them would tend to
promote the breaking down of the strata which roof them over.
No physicist, I believe, has supposed that man can avert the eruption of a
volcano or diminish the quantity of melted rock which it pours out of the
this latter case, the discharge of a vehement current of inflammable fluid
sometimes continues for hours and even longer periods. These facts seem to
render it not wholly improbable that the popular belief of the efficacy of
deep wells in mitigating the violence of earthquakes is well founded.
In general, light, wooden buildings are less injured by earthquakes than
more solid structures of stone or brick, and it is commonly supposed that
the power put forth by the earth-wave is too great to be resisted by any
amount of weight or solidity of mass that man can pile up upon the surface.
But the fact that in countries subject to earthquakes many very large and
strongly constructed palaces, temples, and other monuments have stood for
centuries, comparatively uninjured, suggests a doubt whether this opinion is
sound. The earthquake of the first of November, 1755, which is asserted,
though upon doubtful evidence, to have been felt over a twelfth part of the
earth's surface, was among the most violent of which we have any clear and
distinct account, and it seems to have exerted its most destructive force at
Lisbon. It has often been noticed as a remarkable fact, that the mint, a
building of great solidity, was almost wholly unaffected by the shock which
shattered every house and church in the city, and its escape from the
common ruin can hardly be accounted for except upon the supposition that
its weight, compactness, and strength of material enabled it to resist an
agitation of the earth which overthrew all weaker structures. On the other
hand, a stone pier in the harbor of Lisbon, on which thousands of people
had taken refuge, sank with its foundations to a great depth during the same
earthquake; and it is plain that where subterranean cavities exist, at
moderate depths, the erection of heavy masses upon them would tend to
promote the breaking down of the strata which roof them over.
No physicist, I believe, has supposed that man can avert the eruption of a
volcano or diminish the quantity of melted rock which it pours out of the
Page 777
bowels of the earth; but it is not always impossible to divert the course of
even a large current of lava. "The smaller streams of lava near Catania,"
says Ferrara, in describing the great eruption of 1669, "were turned from
their course by building dry walls of stone as a barrier against them. … It
was proposed to divert the main current from Catania, and fifty men,
protected by hides, were sent with hooks and iron bars to break the flank of
the stream near Belpasso. [Footnote: Soon after the current issues from the
volcano, it is covered above and at its sides, and finally in front, with
scoriae, formed by the cooling of the exposed surface, which bury and
conceal the fluid mass. The stream rolls on under the coating, and between
the walls of scoriae, and it was the lateral crust which was broken through
by the workmen mentioned in the text.
The distance to which lava flows, before its surface begns to solidify,
depends on its volume, its composition, its temperature and that of the air,
the force with which it is ejected, and the inclination of the declivity over
which it runs. In most cases it is difficult to approach the current at points
where it is still entirely fluid, and hence opportunities of observing it in that
condition are not very frequent. In the eruption of February, 1850, on the
east side of Vesuvius, I went quite up to one of the outlets. The lava shot out
of the orifice upwards with great velocity, like the water from a fountain, in
a stream eight or ten feet in diameter, throwing up occasionally volcanic
bombs three or four feet in diameter, which exploded at the height of eight
or ten yards, but it immediately spread out on the declivity down which it
flowed, to the width of several yards. It continued red-hot in broad daylight,
and without a particle of scoriae on its surface, for a course of at least one
hundred yards. At this distance, the suffocating, sulphurous vapors became
so dense that I could follow the current no farther. The undulations of the
surface were like those of a brook swollen by rain. I estimated the height of
the waves at five or six inches by a breadth of eighteen or twenty. To the
even a large current of lava. "The smaller streams of lava near Catania,"
says Ferrara, in describing the great eruption of 1669, "were turned from
their course by building dry walls of stone as a barrier against them. … It
was proposed to divert the main current from Catania, and fifty men,
protected by hides, were sent with hooks and iron bars to break the flank of
the stream near Belpasso. [Footnote: Soon after the current issues from the
volcano, it is covered above and at its sides, and finally in front, with
scoriae, formed by the cooling of the exposed surface, which bury and
conceal the fluid mass. The stream rolls on under the coating, and between
the walls of scoriae, and it was the lateral crust which was broken through
by the workmen mentioned in the text.
The distance to which lava flows, before its surface begns to solidify,
depends on its volume, its composition, its temperature and that of the air,
the force with which it is ejected, and the inclination of the declivity over
which it runs. In most cases it is difficult to approach the current at points
where it is still entirely fluid, and hence opportunities of observing it in that
condition are not very frequent. In the eruption of February, 1850, on the
east side of Vesuvius, I went quite up to one of the outlets. The lava shot out
of the orifice upwards with great velocity, like the water from a fountain, in
a stream eight or ten feet in diameter, throwing up occasionally volcanic
bombs three or four feet in diameter, which exploded at the height of eight
or ten yards, but it immediately spread out on the declivity down which it
flowed, to the width of several yards. It continued red-hot in broad daylight,
and without a particle of scoriae on its surface, for a course of at least one
hundred yards. At this distance, the suffocating, sulphurous vapors became
so dense that I could follow the current no farther. The undulations of the
surface were like those of a brook swollen by rain. I estimated the height of
the waves at five or six inches by a breadth of eighteen or twenty. To the
Page 778
eye, the fluidity of the lava seemed as perfect as that of water, but masses of
cold lava weighing ten or fifteen pounds floated upon it like cork.
The heat emitted by lava currents seems extremely small when we
consider the temperature required to fuse such materials and the great
length of time they take in cooling. I saw at Nicolosi ancient oil-jars,
holding a hundred gallons or more, which had been dug out from under a
stream of old lava above that town. They had been very slightly covered
with volcanic ashes before the lava flowed over them, but the lead with
which holes in them had been plugged was not melted. The current that
buried Mompiliere in 1669 was thirty-five feet thick, but marble statues, in
a church over which the lava formed an arch, were found uncalcined and
uninjured in 1704, See Scrope, Volcanoes, chap. vi. Section 6.]
When the opening was made, fluid lava poured forth and flowed rapidly
towards Paterno; but the inhabitants of that place, not caring to sacrifice
their own town to save Catania, rushed out in arms and put a stop to the
operation." [Footnote: Ferrara, Descrizione dell' Etna, p. 108.] In the
eruption of Vesuvius in 1794, the viceroy saved from impending destruction
the town of Portici, and the valuable collection of antiquities then deposited
there but since removed to Naples, by employing several thousand men to
dig a ditch above the town, by which the lava current was carried off in
another direction. [Footnote: Landgrebe, Naturgeschichte der Vulkane, ii.,
p. 82.]
Incidental Effects of Human Action.
I have more than once alluded to the collateral and unsought
consequences of human action as being often more momentous than the
direct and desired results. There are cases where such incidental, or, in
popular speech, accidental, consequences, though of minor importance in
cold lava weighing ten or fifteen pounds floated upon it like cork.
The heat emitted by lava currents seems extremely small when we
consider the temperature required to fuse such materials and the great
length of time they take in cooling. I saw at Nicolosi ancient oil-jars,
holding a hundred gallons or more, which had been dug out from under a
stream of old lava above that town. They had been very slightly covered
with volcanic ashes before the lava flowed over them, but the lead with
which holes in them had been plugged was not melted. The current that
buried Mompiliere in 1669 was thirty-five feet thick, but marble statues, in
a church over which the lava formed an arch, were found uncalcined and
uninjured in 1704, See Scrope, Volcanoes, chap. vi. Section 6.]
When the opening was made, fluid lava poured forth and flowed rapidly
towards Paterno; but the inhabitants of that place, not caring to sacrifice
their own town to save Catania, rushed out in arms and put a stop to the
operation." [Footnote: Ferrara, Descrizione dell' Etna, p. 108.] In the
eruption of Vesuvius in 1794, the viceroy saved from impending destruction
the town of Portici, and the valuable collection of antiquities then deposited
there but since removed to Naples, by employing several thousand men to
dig a ditch above the town, by which the lava current was carried off in
another direction. [Footnote: Landgrebe, Naturgeschichte der Vulkane, ii.,
p. 82.]
Incidental Effects of Human Action.
I have more than once alluded to the collateral and unsought
consequences of human action as being often more momentous than the
direct and desired results. There are cases where such incidental, or, in
popular speech, accidental, consequences, though of minor importance in
Page 779
themselves, serve to illustrate natural processes; others, where, by the
magnitude and character of the material traces they leave behind them, they
prove that man, in primary or in more advanced stages of social life, must
have occupied particular districts for a longer period than has been
supposed by popular chronology. "On the coast of Jutland," says
Forchhammer, "wherever a bolt from a wreck or any other fragment of iron
is deposited in the beach sand, the particles are cemented together, and form
a very solid mass around the iron. A remarkable formation of this sort was
observed a few years ago in constructing the sea-wall of the harbor of
Elsineur. This stratum, which seldom exceeded a foot in thickness, rested
upon common beach sand, and was found at various depths, less near the
shore, greater at some distance from it. It was composed of pebbles and
sand, and contained a great quantity of pins, and some coins of the reign of
Christian IV., between the beginning and the middle of the seventeenth
century. Here and there, a coating of metallic copper had been deposited by
galvanic action, and the presence of completely oxydized metallic iron was
often detected. Investigation made it in the highest degree probable that this
formation owed its origin to the street sweepings of the town, which had
been thrown upon the beach, and carried off and distributed by the waves
over the bottom of the harbor." [Footnote: Geognostische Studien am
Meeres Ufer, Leonhard und Bronn, 1841, pp. 25, 26.] These and other
familiar observations of the like sort show that a sandstone reef, of no
inconsiderable magnitude, might originate from the stranding of a ship with
a cargo of iron, [Footnote: Kohl, Schleswig-Holstein, ii., p. 45.] or from
throwing the waste of an establishment for working metals into running
water which might carry it to the sea.
Parthey records a singular instance of unforeseen mischief from an
interference with the arrangements of nature. A landowner at Malta
possessed a rocky plateau sloping gradually towards the sea, and
terminating in a precipice forty or fifty feet high, through natural openings
magnitude and character of the material traces they leave behind them, they
prove that man, in primary or in more advanced stages of social life, must
have occupied particular districts for a longer period than has been
supposed by popular chronology. "On the coast of Jutland," says
Forchhammer, "wherever a bolt from a wreck or any other fragment of iron
is deposited in the beach sand, the particles are cemented together, and form
a very solid mass around the iron. A remarkable formation of this sort was
observed a few years ago in constructing the sea-wall of the harbor of
Elsineur. This stratum, which seldom exceeded a foot in thickness, rested
upon common beach sand, and was found at various depths, less near the
shore, greater at some distance from it. It was composed of pebbles and
sand, and contained a great quantity of pins, and some coins of the reign of
Christian IV., between the beginning and the middle of the seventeenth
century. Here and there, a coating of metallic copper had been deposited by
galvanic action, and the presence of completely oxydized metallic iron was
often detected. Investigation made it in the highest degree probable that this
formation owed its origin to the street sweepings of the town, which had
been thrown upon the beach, and carried off and distributed by the waves
over the bottom of the harbor." [Footnote: Geognostische Studien am
Meeres Ufer, Leonhard und Bronn, 1841, pp. 25, 26.] These and other
familiar observations of the like sort show that a sandstone reef, of no
inconsiderable magnitude, might originate from the stranding of a ship with
a cargo of iron, [Footnote: Kohl, Schleswig-Holstein, ii., p. 45.] or from
throwing the waste of an establishment for working metals into running
water which might carry it to the sea.
Parthey records a singular instance of unforeseen mischief from an
interference with the arrangements of nature. A landowner at Malta
possessed a rocky plateau sloping gradually towards the sea, and
terminating in a precipice forty or fifty feet high, through natural openings
Page 780
in which the sea-water flowed into a large cave under the rock. The
proprietor attempted to establish salt-works on the surface, and cut shallow
pools in the rock for the evaporation of the water. In order to fill the salt-
pans more readily, he sank a well down to the cave beneath, through which
he drew up water by a windlass and buckets. The speculation proved a
failure, because the water filtered through the porous bottom of the pans,
leaving little salt behind. But this was a small evil, compared with other
destructive consequences that followed. When the sea was driven into the
cave by violent west or north-west winds, it shot a jet d'eau through the well
to the height of sixty feet, the spray of which was scattered far and wide
over the neighboring gardens and blasted the crops. The well was now
closed with stones, but the next winter's storms hurled them out again, and
spread the salt spray over the grounds in the vicinity as before. Repeated
attempts were made to stop the orifice, but at the time of Parthey's visit the
sea had thrice burst through, and it was feared that the evil was without
remedy. [Footnote: Wanderungen durch Sicilien und die Levante, i., p. 406.]
I have mentioned the great extent of the heaps of oyster and other shells
left by the American Indians on the Atlantic coast of the United States.
Some of the Danish kitchen-middens, which closely resemble them, are a
thousand feet long, from one hundred and fifty to two hundred wide, and
from six to ten high. These piles have an importance as geological
witnesses, independent of their bearing upon human history. Wherever the
coast line appears, from other evidence, to have remained unchanged in
outline and elevation since they were accumulated, they are found near the
sea, and not more than about ten feet above its level. In some cases they are
at a considerable distance from the beach, and in these instances, so far as
yet examined, there are proofs that the coast has advanced in consequence
of upheaval or of fluviatile or marine deposit. Where they are altogether
wanting, the coast seems to have sunk or been washed away by the sea. The
constancy of these observations justifies geologists in arguing, where other
proprietor attempted to establish salt-works on the surface, and cut shallow
pools in the rock for the evaporation of the water. In order to fill the salt-
pans more readily, he sank a well down to the cave beneath, through which
he drew up water by a windlass and buckets. The speculation proved a
failure, because the water filtered through the porous bottom of the pans,
leaving little salt behind. But this was a small evil, compared with other
destructive consequences that followed. When the sea was driven into the
cave by violent west or north-west winds, it shot a jet d'eau through the well
to the height of sixty feet, the spray of which was scattered far and wide
over the neighboring gardens and blasted the crops. The well was now
closed with stones, but the next winter's storms hurled them out again, and
spread the salt spray over the grounds in the vicinity as before. Repeated
attempts were made to stop the orifice, but at the time of Parthey's visit the
sea had thrice burst through, and it was feared that the evil was without
remedy. [Footnote: Wanderungen durch Sicilien und die Levante, i., p. 406.]
I have mentioned the great extent of the heaps of oyster and other shells
left by the American Indians on the Atlantic coast of the United States.
Some of the Danish kitchen-middens, which closely resemble them, are a
thousand feet long, from one hundred and fifty to two hundred wide, and
from six to ten high. These piles have an importance as geological
witnesses, independent of their bearing upon human history. Wherever the
coast line appears, from other evidence, to have remained unchanged in
outline and elevation since they were accumulated, they are found near the
sea, and not more than about ten feet above its level. In some cases they are
at a considerable distance from the beach, and in these instances, so far as
yet examined, there are proofs that the coast has advanced in consequence
of upheaval or of fluviatile or marine deposit. Where they are altogether
wanting, the coast seems to have sunk or been washed away by the sea. The
constancy of these observations justifies geologists in arguing, where other
Page 781
evidence is wanting, the advance of land or sea respectively, or the
elevation or depression of the former, from the position or the absence of
these heaps alone.
Every traveller in Italy is familiar with Monte Testaccio, the mountain of
potsherds, at Rome; [Footnote: Untill recently this hillock was supposed to
consist of shards of household pottery broken in using, but it now appears
to be ascertained that it is composed of fragments of earthenware broken in
transportation from the place of manufacture to the emporium on the Tiber
where such articles were landed.] but this deposit, large as it is, shrinks into
insignificance when compared with masses of similar origin in the
neighborhood of older cities. The castaway pottery of ancient towns in
Magna Grecia composes strata of such extent and thickness that they have
been dignified with the appellation of the ceramic formation. The Nile, as it
slowly changes its bed, exposes in its banks masses of the same material, so
vast that the population of the world during the whole historical period
would seem to have chosen this valley as a general deposit for its broken
vessels.
The fertility imparted to the banks of the Nile by the water and the slime
of the inundations, is such that manures are little employed. Hence much
domestic waste, which would elsewhere be employed to enrich the soil, is
thrown out into vacant places near the town. Hills of rubbish are thus piled
up which astonish the traveller almost as much as the solid pyramids
themselves. The heaps of ashes and other household refuse collected on the
borders and within the limits of Cairo were so large, that the removal of
them by Ibrahim Pacha has been looked upon as one of the great works of
the age.
These heaps formed almost a complete rampart around the city, and
impeded both the circulation of the air and the communication between
elevation or depression of the former, from the position or the absence of
these heaps alone.
Every traveller in Italy is familiar with Monte Testaccio, the mountain of
potsherds, at Rome; [Footnote: Untill recently this hillock was supposed to
consist of shards of household pottery broken in using, but it now appears
to be ascertained that it is composed of fragments of earthenware broken in
transportation from the place of manufacture to the emporium on the Tiber
where such articles were landed.] but this deposit, large as it is, shrinks into
insignificance when compared with masses of similar origin in the
neighborhood of older cities. The castaway pottery of ancient towns in
Magna Grecia composes strata of such extent and thickness that they have
been dignified with the appellation of the ceramic formation. The Nile, as it
slowly changes its bed, exposes in its banks masses of the same material, so
vast that the population of the world during the whole historical period
would seem to have chosen this valley as a general deposit for its broken
vessels.
The fertility imparted to the banks of the Nile by the water and the slime
of the inundations, is such that manures are little employed. Hence much
domestic waste, which would elsewhere be employed to enrich the soil, is
thrown out into vacant places near the town. Hills of rubbish are thus piled
up which astonish the traveller almost as much as the solid pyramids
themselves. The heaps of ashes and other household refuse collected on the
borders and within the limits of Cairo were so large, that the removal of
them by Ibrahim Pacha has been looked upon as one of the great works of
the age.
These heaps formed almost a complete rampart around the city, and
impeded both the circulation of the air and the communication between
Page 782
Cairo and its suburbs. At two points these accumulations are said to have
risen to the incredible height of between six and seven hundred feet; and
these two heaps covered two hundred and fifty acres. [Footnote: Clot Bey,
Egypte, i., p. 277.] During the occupation of Cairo by the French, the
invaders constructed redoubts on these hillocks which commanded the city.
They were removed by Mehemet Ali, and the material was employed in
raising the level of low grounds in the environs. [Footnote: Egypt
manufactures annually about 1,200,000 pounds of nitre, by lixiviating the
ancient and modern rubbish-heaps around the towns.]
In European and American cities, street sweepings and other town refuse
are used as manure and spread over the neighboring fields, the surface of
which is perceptibly raised by them, by vegetable deposit, and by other
effects of human industry, and in spite of all efforts to remove the waste, the
level of the ground on which large towns stand is constantly elevated. The
present streets of Rome are twenty feet, and in many places much more,
above those of the ancient city. The Appian Way between Rome and
Albano, when cleared out a few years ago, was found buried four or five
feet deep, and the fields along the road were elevated nearly or quite as
much. The floors of many churches in Italy, not more than six or seven
centuries old, are now three or four feet below the adjacent streets, though it
is proved by excavations that they were built as many feet above them.
[Footnote: Rafinesque maintained many years ago that there was a
continual deposition of dust on the surface of the earth from the
atmosphere, or from cosmical space, sufficient in quantity to explain no
small part of the elevation referred to in the text. Observations during the
eclipse of Dec. 22, 1870, led some astronomers to believe that the
appearance of the corona was dependent upon or modified by cosmical dust
or matter in a very attenuated form diffused through space.
risen to the incredible height of between six and seven hundred feet; and
these two heaps covered two hundred and fifty acres. [Footnote: Clot Bey,
Egypte, i., p. 277.] During the occupation of Cairo by the French, the
invaders constructed redoubts on these hillocks which commanded the city.
They were removed by Mehemet Ali, and the material was employed in
raising the level of low grounds in the environs. [Footnote: Egypt
manufactures annually about 1,200,000 pounds of nitre, by lixiviating the
ancient and modern rubbish-heaps around the towns.]
In European and American cities, street sweepings and other town refuse
are used as manure and spread over the neighboring fields, the surface of
which is perceptibly raised by them, by vegetable deposit, and by other
effects of human industry, and in spite of all efforts to remove the waste, the
level of the ground on which large towns stand is constantly elevated. The
present streets of Rome are twenty feet, and in many places much more,
above those of the ancient city. The Appian Way between Rome and
Albano, when cleared out a few years ago, was found buried four or five
feet deep, and the fields along the road were elevated nearly or quite as
much. The floors of many churches in Italy, not more than six or seven
centuries old, are now three or four feet below the adjacent streets, though it
is proved by excavations that they were built as many feet above them.
[Footnote: Rafinesque maintained many years ago that there was a
continual deposition of dust on the surface of the earth from the
atmosphere, or from cosmical space, sufficient in quantity to explain no
small part of the elevation referred to in the text. Observations during the
eclipse of Dec. 22, 1870, led some astronomers to believe that the
appearance of the corona was dependent upon or modified by cosmical dust
or matter in a very attenuated form diffused through space.
Page 783
Tyndall has shown by optical tests that the proportion of solid matter
suspended or floating in common air is very considerable, and there is
abundant other evidence to the name purpose. Ehrenberg has found African
and even American infusoria in dust transplanted by winds and let fall in
Europe, and Schliemann offers that the quantity of dust brought by the
scirocco from Africa is so great, that by cutting holes in the naked rocks of
Malta enough of Libyan transported earth can be caught and retained, in the
course of fourteen years, to form a soil fit for cultivation.—Beilage zur
Allgemeinen Zeitung, Mar. 24, 1870.]
Nothing Small in Nature.
It is a legal maxim that "the law concerneth not itself with trifles," de
minimis non curat lex; but in the vocabulary of nature, little and great are
terms of comparison only; she knows no trifles, and her laws are as
inflexible in dealing with an atom as with a continent or a planet. [Footnote:
One of the sublimest, and at the same time most fearful suggestions that
have been prompted by the researches of modern science, was made by
Babbage in the ninth chapter of his Ninth Bridgewater Treatise. I have not
the volume at hand, but the following explanation will recall to the reader, if
it does not otherwise make intelligible, the suggestion I refer to:
No atom can be disturbed in place, or undergo any change of
temperature, of electrical state, or other material condition, without
affecting, by attraction or repulsion or other communication, the
surrounding atoms. These, again, by the same law, transmit the influence to
other atoms, and the impulse thus given extends through the whole material
universe. Every human movement, every organic act, every volition,
passion, or emotion, every intellectual process, is accompanied with atomic
disturbance, and hence every such movement, every such act or process,
affects all the atoms of universal matter. Though action and reaction are
suspended or floating in common air is very considerable, and there is
abundant other evidence to the name purpose. Ehrenberg has found African
and even American infusoria in dust transplanted by winds and let fall in
Europe, and Schliemann offers that the quantity of dust brought by the
scirocco from Africa is so great, that by cutting holes in the naked rocks of
Malta enough of Libyan transported earth can be caught and retained, in the
course of fourteen years, to form a soil fit for cultivation.—Beilage zur
Allgemeinen Zeitung, Mar. 24, 1870.]
Nothing Small in Nature.
It is a legal maxim that "the law concerneth not itself with trifles," de
minimis non curat lex; but in the vocabulary of nature, little and great are
terms of comparison only; she knows no trifles, and her laws are as
inflexible in dealing with an atom as with a continent or a planet. [Footnote:
One of the sublimest, and at the same time most fearful suggestions that
have been prompted by the researches of modern science, was made by
Babbage in the ninth chapter of his Ninth Bridgewater Treatise. I have not
the volume at hand, but the following explanation will recall to the reader, if
it does not otherwise make intelligible, the suggestion I refer to:
No atom can be disturbed in place, or undergo any change of
temperature, of electrical state, or other material condition, without
affecting, by attraction or repulsion or other communication, the
surrounding atoms. These, again, by the same law, transmit the influence to
other atoms, and the impulse thus given extends through the whole material
universe. Every human movement, every organic act, every volition,
passion, or emotion, every intellectual process, is accompanied with atomic
disturbance, and hence every such movement, every such act or process,
affects all the atoms of universal matter. Though action and reaction are
Page 784
equal, yet reaction does not restore disturbed atoms to their former place
and condition, and consequently the effects of the least material change are
never cancelled, but in some way perpetuated, so that no action can take
place in physical, moral, or intellectual nature, without leaving all matter in
a different state from what it would have been if such action had not
occurred. Hence, to use language which I have employed on another
occasion: there exists, not alone in the human conscience or in the
omniscience of the Creator, but in external nature, an ineffaceable,
imperishable record, possibly legible even to created intelligence, of every
act done, every word uttered, nay, of every wish and purpose and thought
conceived, by mortal man, from the birth of our first parent to the final
extinction of our race; so that the physical traces of our most secret sins
shall last until time shall be merged in that eternity of which not science,
but religion alone assumes to take cognisance.]
The human operations mentioned in the last few paragraphs, therefore,
do act in the ways ascribed to them, though our limited faculties are at
present, perhaps forever, incapable of weighing their immediate, still more
their ultimate consequences. But our inability to assign definite values to
these causes of the disturbance of natural arrangements is not a reason for
ignoring the existence of such causes in any general view of the relations
between man and nature, and we are never justified in assuming a force to
be insignificant because its measure is unknown, or even because no
physical effect can now be traced to it as its origin. The collection of
phenomena must precede the analysis of them, and every new fact,
illustrative of the action and reaction between humanity and the material
world around it, is another step towards the determination of the great
question, whether man is of material nature or above her.
THE END
and condition, and consequently the effects of the least material change are
never cancelled, but in some way perpetuated, so that no action can take
place in physical, moral, or intellectual nature, without leaving all matter in
a different state from what it would have been if such action had not
occurred. Hence, to use language which I have employed on another
occasion: there exists, not alone in the human conscience or in the
omniscience of the Creator, but in external nature, an ineffaceable,
imperishable record, possibly legible even to created intelligence, of every
act done, every word uttered, nay, of every wish and purpose and thought
conceived, by mortal man, from the birth of our first parent to the final
extinction of our race; so that the physical traces of our most secret sins
shall last until time shall be merged in that eternity of which not science,
but religion alone assumes to take cognisance.]
The human operations mentioned in the last few paragraphs, therefore,
do act in the ways ascribed to them, though our limited faculties are at
present, perhaps forever, incapable of weighing their immediate, still more
their ultimate consequences. But our inability to assign definite values to
these causes of the disturbance of natural arrangements is not a reason for
ignoring the existence of such causes in any general view of the relations
between man and nature, and we are never justified in assuming a force to
be insignificant because its measure is unknown, or even because no
physical effect can now be traced to it as its origin. The collection of
phenomena must precede the analysis of them, and every new fact,
illustrative of the action and reaction between humanity and the material
world around it, is another step towards the determination of the great
question, whether man is of material nature or above her.
THE END
Page 785
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