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The Project Gutenberg eBook of Man and
Nature; Or, Physical Geography as Modified
by Human Action
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Title: Man and Nature; Or, Physical Geography as Modified by Human
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Author: George P. Marsh
Release date: November 9, 2011 [eBook #37957]
Language: English
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Internet Archive/American Libraries.)
*** START OF THE PROJECT GUTENBERG EBOOK MAN AND
NATURE; OR, PHYSICAL GEOGRAPHY AS MODIFIED BY HUMAN
ACTION ***
Nature; Or, Physical Geography as Modified
by 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: Man and Nature; Or, Physical Geography as Modified by Human
Action
Author: George P. Marsh
Release date: November 9, 2011 [eBook #37957]
Language: English
Other information and formats: www.gutenberg.org/ebooks/37957
Credits: Produced by Julia Miller and the Online Distributed
Proofreading Team at http://www.pgdp.net (This file was
produced from images generously made available by The
Internet Archive/American Libraries.)
*** START OF THE PROJECT GUTENBERG EBOOK MAN AND
NATURE; OR, PHYSICAL GEOGRAPHY AS MODIFIED BY HUMAN
ACTION ***
Page 4
TRANSCRIBER'S NOTE: In this HTML
version, some of the references to appendix
notes within footnotes which were incorrect
have been corrected. Also, errors found in page
number references within Appendix have been
corrected.
MAN AND NATURE;
OR,
PHYSICAL GEOGRAPHY
AS MODIFIED BY HUMAN ACTION.
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.
version, some of the references to appendix
notes within footnotes which were incorrect
have been corrected. Also, errors found in page
number references within Appendix have been
corrected.
MAN AND NATURE;
OR,
PHYSICAL GEOGRAPHY
AS MODIFIED BY HUMAN ACTION.
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.
Page 5
Bushnell, Sermon on the Power of an
Endless Life.
NEW YORK:
CHARLES SCRIBNER & CO., No. 654
BROADWAY.
1867.
Entered, according to Act of Congress, in the year 1864, by
CHARLES SCRIBNER,
In the Clerk's Office of the District Court of the United States for the
Southern District of New York.
JOHN F. TROW & CO.
PRINTER, STEREOTYPER, AND ELECTROTYPER,
46, 48, & 50 Greene St., New York.
Endless Life.
NEW YORK:
CHARLES SCRIBNER & CO., No. 654
BROADWAY.
1867.
Entered, according to Act of Congress, in the year 1864, by
CHARLES SCRIBNER,
In the Clerk's Office of the District Court of the United States for the
Southern District of New York.
JOHN F. TROW & CO.
PRINTER, STEREOTYPER, AND ELECTROTYPER,
46, 48, & 50 Greene St., New York.
Page 6
P R E F A C E.
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 subvert the original balance of its species,
and while it reduces the numbers of some of them, 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
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.
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 subvert the original balance of its species,
and while it reduces the numbers of some of them, 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
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.
Page 7
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
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 Probable and Possible
Geographical Revolutions yet to be effected by the art of man.
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
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 Probable and Possible
Geographical Revolutions yet to be effected by the art of man.
Page 8
I have only 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 educated, observing, and thinking men; and that my
purpose is rather to make practical suggestions than to indulge in theoretical
speculations properly suited to a different class from that to which those for
whom I write belong.
GEORGE P. MARSH.
December 1, 1863.
the volume, that I address myself not to professed physicists, but to the
general intelligence of educated, observing, and thinking men; and that my
purpose is rather to make practical suggestions than to indulge in theoretical
speculations properly suited to a different class from that to which those for
whom I write belong.
GEORGE P. MARSH.
December 1, 1863.
Page 9
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Amersfoordt, J. P. Het Haarlemmermeer, Oorsprong, Geschiedenis, Droogmaking. Haarlem,
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Andresen, C. C. Om Klitformationen og Klittens Behandling og Bestyrelse. Kjöbenhavn, 1861.
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Annali di Agricoltura, Industria e Commercio. Pubblicati per cura del Ministero d'Agricoltura,
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Arago, F. Extracts from, in Becquerel, Des Climats.
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Asbjörnsen, P. Chr. Om Skovene og om et ordnet Skovbrug i Norge. Christiania, 1855. 12mo.
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—— Éléments de Physique Terrestre et de Météorologie. Paris, 1847. 8vo.
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Page 10
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Paris.
Statens Borger. Kjöbenhavn, 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 États Unis d'Amérique en 1863. Paris, 1863. 8vo.
Blake, Wm. P. Reports in Pacific Railroad Report, vols. ii and v.
Blanqui. Mémoire sur les Populations des Hautes Alpes; in Mémoires de l'Académie des Sciences
Morales et Politiques, 1843.
—— Voyage en Bulgarie. Paris, 1843. 12mo.
—— Précis Élémentaire d'Économie Politique, suivi du Résumé de l'Histoire du Commerce et de
l'Industrie. Paris, 1857. 12mo.
Boitel, Amédée. Mise en valeur des Terres pauvres par le Pin Maritime. 2d edition. Paris, 1857.
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Bonnemère, Eugène. Histoire des Paysans depuis la fin du Moyen Age jusqu'à nos jours. Paris,
1856. 2 vols. 8vo.
Böttger, C. Das Mittelmeer. Leipzig, 1859.
Boussingault, J. B. Économie Rurale considerée dans ses Rapports avec la Chimie, la Physique,
et la Météorologie. 2d edition. Paris, 1851. 2 vols. 8vo.
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Castellani. Dell' immediata influenza delle Selve sul corso delle acque. 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 Siècle jusqu'à nos jours. Paris,
1858, 1862. Vols. i-iv, 8vo.
Chateauvieux, F. Lullin de. Lettres sur l'Italie. Seconde edition, Genève, 1834. 8vo.
Chevandier. Extracts in Comptes Rendus à l'Académie des Sciences. Juillet-Decembre, 1844.
Paris.
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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.
Courier, Paul-Louis. Œuvres Complètes. Bruxelles, 1833. 8vo.
Dana, James D. Manual of Geology. Philadelphia, 1863. 8vo.
Delamarre, L. G. Historique de la Création d'une Richesse Millionaire par la culture des Pins.
Paris, 1827. 8vo.
D. Héricourt, A. F. Les Inondations et le livre de M. Vallès; Annales Forestières, December, 1857,
pp. 310, 321. Paris.
Diggelen, B. P. G. van. Groote 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 à propos de l'Exposition Universelle de Paris. Paris, 1856. 8vo.
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France, par Michaud et Poujoulat. Tome i. Paris, 1836. 8vo.
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Jahrbuch für Mineralogie, Geognosie, Geologie, etc. Jahrgang, 1841, pp. 1-38.
Fossombroni, Vittorio. Memorie Idraulico-Storiche sopra la Val-di-Chiana. Montepulciano, 3za
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v.
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'9. 3 vols. folio.
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Herschel, Sir J. F. W. Physical Geography. Edinburgh, 1861. 12mo.
Heyer, Gustav. Das Verhalten der Waldbäume gegen Licht und Schatten. Erlangen, 1852. 8vo.
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8vo.
Humboldt, Alexander von. Ansichten der Natur. Dritte Ausgabe, Stuttgart und Tübingen, 1849. 2
vols. 12mo.
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Page 13
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Stockholm, 1831. 8vo.
—— Fortsättning af Journalen öfver Missions-Resor i Lappmarken. Stockholm, 1833. 8vo.
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Le Alpi che cingono l'Italia. Parte 1er, vol. 1er. Torino, 1845. 8vo.
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Lastadius, Lars Levi. Om Möjligheten och Fördelen af allmänna Uppodlingar i Lappmarken.
Stockholm, 1824. 12mo.
Læstadius, Petrus. Journal för första året af hans Tjenstgöring såsom Missionaire i Lappmarken.
Stockholm, 1831. 8vo.
—— Fortsättning af Journalen öfver Missions-Resor i Lappmarken. Stockholm, 1833. 8vo.
Lampridius. Vita Elagabali in Script. Hist., August.
Landgrebe, Georg. Naturgeschichte der Vulcane. Gotha, 1855. 2 vols. 8vo.
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de France.
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2me sémestre, pp. 218-268.
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Le Alpi che cingono l'Italia. Parte 1er, vol. 1er. Torino, 1845. 8vo.
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2me sémestre, pp. 320-332.
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Page 14
Lorentz. Cours Élémentaire de Culture des Bois, complété et publie par A. Parade, 4me edition.
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Martineau. Endeavors after the Christian Life. Boston, 1858.
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etc. Milano, 1859. 8vo.
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Meyer, J. Physik der Schweiz. Leipzig, 1854. 8vo.
Michelet, J. L'Insecte, 4me edition. Paris, 1860. 12mo.
—— L'Oiseau, 7me edition. Paris, 1861. 12mo.
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point de vue des Inondations. Paris, 1858. 8vo.
Montluisant. Note sur les Desséchements, les Endiguements et les Irrigations; in Annales des
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Washington, various years. 12 vols. 4to.
Palissy, Bernard. Œuvres Complètes, avec des Notes, etc., par Paul-Antoine Cap. Paris, 1844.
12mo.
Parade, A. See Lorentz.
Paris et Nancy, 1860. 8vo.
Lyell, Sir Charles. The Geological Evidence of the Antiquity of Man. London, 1863. 8vo.
Principles of Geology. New York, 1862. 8vo.
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Martineau. Endeavors after the Christian Life. Boston, 1858.
Martins. Revue des Deux Mondes, Avril, 1863.
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Medlicott, Dr. Observations of, quoted from London Athenæum, 1863.
Meguscher, Francesco. Memorie sulla migliore maniera per rimettere i Boschi della Lombardia,
etc. Milano, 1859. 8vo.
Mejdell, Th. Om Foranstaltninger til Behandling af Norges Skove. Christiania, 1858. 8vo.
Mella. Delle Inondazioni del Mella nella notto del 14 al 15 Agosto, 1850. Brescia, 1851. 8vo.
Meyer, J. Physik der Schweiz. Leipzig, 1854. 8vo.
Michelet, J. L'Insecte, 4me edition. Paris, 1860. 12mo.
—— L'Oiseau, 7me edition. Paris, 1861. 12mo.
Monestier-Savignat, A. Étude sur les Phénomènes, l'Aménagement et la Législation des Eaux au
point de vue des Inondations. Paris, 1858. 8vo.
Montluisant. Note sur les Desséchements, les Endiguements et les Irrigations; in Annales des
Ponts et Chaussées, 1833, 2me sémestre, pp. 281-294.
Morozzi, Ferdinando. Dello Stato Antico e Moderno del Fiume Arno. Firenze, 1762. 4to.
Müller, K. Das Buch der Pflanzenwelt. Leipzig, 1857. 2 vols. 12mo.
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Michaud et Poujoulat. Vol. i. Paris, 1836.
Nanquette, Henri. Cours d'Aménagement des Forêts. Paris et Nancy, 1860. 8vo.
Newberry, Dr. Report in Pacific Railroad Report, vol. vi.
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Niel. L'Agriculture des États Sardes. Turin, 1857. 8vo.
Pacific Railroad Report. Reports of Explorations and Surveys for a Railroad Route to the Pacific.
Washington, various years. 12 vols. 4to.
Palissy, Bernard. Œuvres Complètes, avec des Notes, etc., par Paul-Antoine Cap. Paris, 1844.
12mo.
Parade, A. See Lorentz.
Page 15
Paramelle, Abbé. Quellenkunde, Lehre von der Bildung und Auffindung der Quellen; mit einem
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—— Raccolta di Documenti sul Bonificamento delle Maremmo Toscane. Firenze, 1861. 8vo.
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—— Rapporto sulle Operazioni Idrauliche ed Economiche eseguite nel 1859-'60 nelle Maremmo
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Parthey, G. Wanderungen durch Sicilien und die Levante. Berlin, 1834. 2 vols. 12mo.
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Plinii, Historia Naturalis, ed. Hardouin. Paris, 1723. 3 vols. folio.
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—— Die Erdkunde im Verhältniss zur Natur und zur Geschichte des Menschen. Berlin, various
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—— Raccolta di Documenti sul Bonificamento delle Maremmo Toscane. Firenze, 1861. 8vo.
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—— Rapporto sulle Operazioni Idrauliche ed Economiche eseguite nel 1859-'60 nelle Maremmo
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Smith, John. Historie of Virginia. London, 1624. Folio.
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—— Voormaals en Thans. Haarlem, 1858. 8vo.
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—— Appendix to History of Vermont. Burlington, 1853. 8vo.
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Page 17
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Wetzstein, J. G. Reisebericht über Hauran und die Trachonen. Berlin, 1860. 8vo.
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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 années 1787, 1788, 1789, précédée d'une
introduction par Lavergne. Paris, 1860. 2 vols. 12mo.
—— Voyages en Italie et en Espagne, pendant les années 1787, 1789. Paris, 1860. 1 vol. 12mo.
Page 18
TABLE OF CONTENTS.
CHAPTER I.
INTRODUCTORY.
ural Advantages of the Territory of the Roman Empire—Physical Decay of
that Territory and of other parts of the Old World—Causes of the Decay—
New School of Geographers—Reaction of Man upon Nature—Observation
of Nature—Cosmical and Geological Influences—Geographical Influence
of Man—Uncertainty of our Meteorological Knowledge—Mechanical
Effects produced by Man on the surface of the Earth—Importance and
Possibility of Physical Restoration—Stability of Nature—Restoration of
Disturbed Harmonies—Destructiveness of Man—Physical Improvement—
Human and Brute Action Compared—Forms and Formations most liable to
Physical Degradation—Physical Decay of New Countries—Corrupt
Influence of Private Corporations, Note, 1
CHAPTER II.
TRANSFER, MODIFICATION, AND EXTIRPATION OF VEGETABLE
AND OF ANIMAL SPECIES.
dern Geography embraces Organic Life—Transfer of Vegetable Life—
Foreign Plants grown in the United States—American Plants grown in
Europe—Modes of Introduction of Foreign Plants—Vegetables, how
affected by transfer to Foreign Soils—Extirpation of Vegetables—Origin of
Domestic Plants—Organic Life as a Geological and Geographical Agency
—Origin and Transfer of Domestic Animals—Extirpation of Animals—
Numbers of Birds in the United States—Birds as Sowers and Consumers of
Seeds, and as Destroyers of Insects—Diminution and Extirpation of Birds
—Introduction of Birds—Utility of Insects and Worms—Introduction of
Insects—Destruction of Insects—Reptiles—Destruction of Fish—
Introduction and Breeding of Fish—Extirpation of Aquatic Animals—
Minute Organisms, 57
CHAPTER I.
INTRODUCTORY.
ural Advantages of the Territory of the Roman Empire—Physical Decay of
that Territory and of other parts of the Old World—Causes of the Decay—
New School of Geographers—Reaction of Man upon Nature—Observation
of Nature—Cosmical and Geological Influences—Geographical Influence
of Man—Uncertainty of our Meteorological Knowledge—Mechanical
Effects produced by Man on the surface of the Earth—Importance and
Possibility of Physical Restoration—Stability of Nature—Restoration of
Disturbed Harmonies—Destructiveness of Man—Physical Improvement—
Human and Brute Action Compared—Forms and Formations most liable to
Physical Degradation—Physical Decay of New Countries—Corrupt
Influence of Private Corporations, Note, 1
CHAPTER II.
TRANSFER, MODIFICATION, AND EXTIRPATION OF VEGETABLE
AND OF ANIMAL SPECIES.
dern Geography embraces Organic Life—Transfer of Vegetable Life—
Foreign Plants grown in the United States—American Plants grown in
Europe—Modes of Introduction of Foreign Plants—Vegetables, how
affected by transfer to Foreign Soils—Extirpation of Vegetables—Origin of
Domestic Plants—Organic Life as a Geological and Geographical Agency
—Origin and Transfer of Domestic Animals—Extirpation of Animals—
Numbers of Birds in the United States—Birds as Sowers and Consumers of
Seeds, and as Destroyers of Insects—Diminution and Extirpation of Birds
—Introduction of Birds—Utility of Insects and Worms—Introduction of
Insects—Destruction of Insects—Reptiles—Destruction of Fish—
Introduction and Breeding of Fish—Extirpation of Aquatic Animals—
Minute Organisms, 57
Page 19
CHAPTER III.
THE WOODS.
Habitable Earth originally Wooded—The Forest does not furnish Food for
Man—First Removal of the Woods—Effects of Fire on Forest Soil—Effects
of the Destruction of the Forest—Electrical Influence of Trees—Chemical
Influence of the Forest.
Influence of the Forest, considered as Inorganic Matter, on Temperature:
a, Absorbing and Emitting Surface; b, Trees as Conductors of Heat; c, Trees
in Summer and in Winter; d, Dead Products of Tree; e, Trees as a Shelter to
Grounds to the leeward of them; f, Trees as a Protection against Malaria—
The Forest, as Inorganic Matter, tends to mitigate extremes.
Trees as Organisms: Specific Temperature—Total Influence of the
Forest on Temperature.
Influence of Forests on the Humidity of the Air and the Earth: a, as
Inorganic Matter; b, as Organic—Wood Mosses and Fungi—Flow of Sap—
Absorption and Exhalation of Moisture by Trees—Balance of Conflicting
Influences—Influence of the Forest on Temperature and Precipitation—
Influence of the Forest on the Humidity of the Soil—Its Influence on the
Flow of Springs—General Consequences of the Destruction of the Woods
—Literature and Condition of the Forest in different Countries—The
Influence of the Forest on Inundations—Destructive Action of Torrents—
The Po and its Deposits—Mountain Slides—Protection against the Fall of
Rocks and Avalanches by Trees—Principal Causes of the Destruction of the
Forest—American Forest Trees—Special Causes of the Destruction of
European Woods—Royal Forests and Game Laws—Small Forest Plants,
Vitality of Seeds—Utility of the Forest—The Forests of Europe—Forests of
the United States and Canada—The Economy of the Forest—European and
American Trees Compared—Sylviculture—Instability of American Life,
128
CHAPTER IV.
THE WOODS.
Habitable Earth originally Wooded—The Forest does not furnish Food for
Man—First Removal of the Woods—Effects of Fire on Forest Soil—Effects
of the Destruction of the Forest—Electrical Influence of Trees—Chemical
Influence of the Forest.
Influence of the Forest, considered as Inorganic Matter, on Temperature:
a, Absorbing and Emitting Surface; b, Trees as Conductors of Heat; c, Trees
in Summer and in Winter; d, Dead Products of Tree; e, Trees as a Shelter to
Grounds to the leeward of them; f, Trees as a Protection against Malaria—
The Forest, as Inorganic Matter, tends to mitigate extremes.
Trees as Organisms: Specific Temperature—Total Influence of the
Forest on Temperature.
Influence of Forests on the Humidity of the Air and the Earth: a, as
Inorganic Matter; b, as Organic—Wood Mosses and Fungi—Flow of Sap—
Absorption and Exhalation of Moisture by Trees—Balance of Conflicting
Influences—Influence of the Forest on Temperature and Precipitation—
Influence of the Forest on the Humidity of the Soil—Its Influence on the
Flow of Springs—General Consequences of the Destruction of the Woods
—Literature and Condition of the Forest in different Countries—The
Influence of the Forest on Inundations—Destructive Action of Torrents—
The Po and its Deposits—Mountain Slides—Protection against the Fall of
Rocks and Avalanches by Trees—Principal Causes of the Destruction of the
Forest—American Forest Trees—Special Causes of the Destruction of
European Woods—Royal Forests and Game Laws—Small Forest Plants,
Vitality of Seeds—Utility of the Forest—The Forests of Europe—Forests of
the United States and Canada—The Economy of the Forest—European and
American Trees Compared—Sylviculture—Instability of American Life,
128
CHAPTER IV.
Page 20
THE WATERS.
d artificially won from the Waters: a, Exclusion of the Sea by Diking; b,
Draining of Lakes and Marshes; c, Geographical Influence of such
Operations—Lowering of Lakes—Mountain Lakes—Climatic Effects of
Draining Lakes and Marshes.
Geographical and Climatic Effects of Aqueducts, Reservoirs, and
Canals—Surface and Underdraining, and their Climatic and Geographical
Effects—Irrigation and its Climatic and Geographical Effects.
Inundations and Torrents: a, River Embankments; b, Floods of the
Ardèche; c, Crushing Force of Torrents; d, Inundations of 1856 in France; e,
Remedies against Inundations—Consequences if the Nile had been
confined by Lateral Dikes.
Improvements in the Val di Chiana—Improvements in the Tuscan
Maremme—Obstruction of River Mouths—Subterranean Waters—Artesian
Wells—Artificial Springs—Economizing Precipitation, 330
CHAPTER V.
THE SANDS.
gin of Sand—Sand now carried down to the Sea—The Sands of Egypt and
the adjacent Desert—The Suez Canal—The Sands of Egypt—Coast Dunes
and Sand Plains—Sand Banks—Dunes on Coast of America—Dunes of
Western Europe—Formation of Dunes—Character of Dune Sand—Interior
Structure of Dunes—Form of Dunes—Geological Importance of Dunes—
Inland Dunes—Age, Character, and Permanence of Dunes—Use of Dunes
as Barrier against the Sea—Encroachments of the Sea—The Lümfjord—
Encroachments of the Sea—Drifting of Dune Sands—Dunes of Gascony—
Dunes of Denmark—Dunes of Prussia—Artificial Formation of Dunes—
Trees suitable for Dune Plantations—Extent of Dunes in Europe—Dune
Vineyards of Cape Breton—Removal of Dunes—Inland Sand Plains—The
Landes of Gascony—The Belgian Campine—Sands and Steppes of Eastern
Europe—Advantages of Reclaiming Dunes—Government Works of
Improvement, 451
d artificially won from the Waters: a, Exclusion of the Sea by Diking; b,
Draining of Lakes and Marshes; c, Geographical Influence of such
Operations—Lowering of Lakes—Mountain Lakes—Climatic Effects of
Draining Lakes and Marshes.
Geographical and Climatic Effects of Aqueducts, Reservoirs, and
Canals—Surface and Underdraining, and their Climatic and Geographical
Effects—Irrigation and its Climatic and Geographical Effects.
Inundations and Torrents: a, River Embankments; b, Floods of the
Ardèche; c, Crushing Force of Torrents; d, Inundations of 1856 in France; e,
Remedies against Inundations—Consequences if the Nile had been
confined by Lateral Dikes.
Improvements in the Val di Chiana—Improvements in the Tuscan
Maremme—Obstruction of River Mouths—Subterranean Waters—Artesian
Wells—Artificial Springs—Economizing Precipitation, 330
CHAPTER V.
THE SANDS.
gin of Sand—Sand now carried down to the Sea—The Sands of Egypt and
the adjacent Desert—The Suez Canal—The Sands of Egypt—Coast Dunes
and Sand Plains—Sand Banks—Dunes on Coast of America—Dunes of
Western Europe—Formation of Dunes—Character of Dune Sand—Interior
Structure of Dunes—Form of Dunes—Geological Importance of Dunes—
Inland Dunes—Age, Character, and Permanence of Dunes—Use of Dunes
as Barrier against the Sea—Encroachments of the Sea—The Lümfjord—
Encroachments of the Sea—Drifting of Dune Sands—Dunes of Gascony—
Dunes of Denmark—Dunes of Prussia—Artificial Formation of Dunes—
Trees suitable for Dune Plantations—Extent of Dunes in Europe—Dune
Vineyards of Cape Breton—Removal of Dunes—Inland Sand Plains—The
Landes of Gascony—The Belgian Campine—Sands and Steppes of Eastern
Europe—Advantages of Reclaiming Dunes—Government Works of
Improvement, 451
Page 21
CHAPTER VI.
PROJECTED OR POSSIBLE GEOGRAPHICAL CHANGES BY MAN.
ting of Marine Isthmuses—The Suez Canal—Canal across Isthmus of Darien
—Canals to the Dead Sea—Maritime Canals in Greece—Canal of Saros—
Cape Cod Canal—Diversion of the Nile—Changes in the Caspian—
Improvements in North American Hydrography—Diversion of the Rhine—
Draining of the Zuiderzee—Waters of the Karst—Subterranean Waters of
Greece—Soil below Rock—Covering Rocks with Earth—Wadies of Arabia
Petræa—Incidental Effects of Human Action—Resistance to great Natural
Forces—Effects of Mining—Espy's Theories—River Sediment—Nothing
small in Nature, 517
PROJECTED OR POSSIBLE GEOGRAPHICAL CHANGES BY MAN.
ting of Marine Isthmuses—The Suez Canal—Canal across Isthmus of Darien
—Canals to the Dead Sea—Maritime Canals in Greece—Canal of Saros—
Cape Cod Canal—Diversion of the Nile—Changes in the Caspian—
Improvements in North American Hydrography—Diversion of the Rhine—
Draining of the Zuiderzee—Waters of the Karst—Subterranean Waters of
Greece—Soil below Rock—Covering Rocks with Earth—Wadies of Arabia
Petræa—Incidental Effects of Human Action—Resistance to great Natural
Forces—Effects of Mining—Espy's Theories—River Sediment—Nothing
small in Nature, 517
Page 22
CHAPTER I.
I N T R O D U C T O R Y.
NATURAL ADVANTAGES OF THE TERRITORY OF THE ROMAN EMPIRE—PHYSICAL
DECAY OF THAT TERRITORY AND OF OTHER PARTS OF THE OLD WORLD—CAUSES OF
THE DECAY—NEW SCHOOL OF GEOGRAPHERS—REACTION OF MAN UPON NATURE—
OBSERVATION OF NATURE—COSMICAL AND GEOLOGICAL INFLUENCES—
GEOGRAPHICAL INFLUENCE OF MAN—UNCERTAINTY OF OUR METEOROLOGICAL
KNOWLEDGE—MECHANICAL EFFECTS PRODUCED BY MAN ON THE SURFACE OF THE
EARTH—IMPORTANCE AND POSSIBILITY OF PHYSICAL RESTORATION—STABILITY OF
NATURE—RESTORATION OF DISTURBED HARMONIES—DESTRUCTIVENESS OF MAN
—PHYSICAL IMPROVEMENT—HUMAN AND BRUTE ACTION COMPARED—FORMS AND
FORMATIONS MOST LIABLE TO PHYSICAL DEGRADATION—PHYSICAL DECAY OF
NEW COUNTRIES—CORRUPT INFLUENCE OF PRIVATE CORPORATIONS, note.
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 advantages. The provinces bordering on the principal and the
secondary basins of the Mediterranean enjoyed a healthfulness and an
equability of climate, a fertility of soil, a variety of vegetable and mineral
products, and natural facilities for the transportation and distribution of
exchangeable commodities, which have not been possessed in an 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
I N T R O D U C T O R Y.
NATURAL ADVANTAGES OF THE TERRITORY OF THE ROMAN EMPIRE—PHYSICAL
DECAY OF THAT TERRITORY AND OF OTHER PARTS OF THE OLD WORLD—CAUSES OF
THE DECAY—NEW SCHOOL OF GEOGRAPHERS—REACTION OF MAN UPON NATURE—
OBSERVATION OF NATURE—COSMICAL AND GEOLOGICAL INFLUENCES—
GEOGRAPHICAL INFLUENCE OF MAN—UNCERTAINTY OF OUR METEOROLOGICAL
KNOWLEDGE—MECHANICAL EFFECTS PRODUCED BY MAN ON THE SURFACE OF THE
EARTH—IMPORTANCE AND POSSIBILITY OF PHYSICAL RESTORATION—STABILITY OF
NATURE—RESTORATION OF DISTURBED HARMONIES—DESTRUCTIVENESS OF MAN
—PHYSICAL IMPROVEMENT—HUMAN AND BRUTE ACTION COMPARED—FORMS AND
FORMATIONS MOST LIABLE TO PHYSICAL DEGRADATION—PHYSICAL DECAY OF
NEW COUNTRIES—CORRUPT INFLUENCE OF PRIVATE CORPORATIONS, note.
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 advantages. The provinces bordering on the principal and the
secondary basins of the Mediterranean enjoyed a healthfulness and an
equability of climate, a fertility of soil, a variety of vegetable and mineral
products, and natural facilities for the transportation and distribution of
exchangeable commodities, which have not been possessed in an 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
Page 23
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 carnelian 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 some of the 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. 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. 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,
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.
Only for the sense of landscape beauty did unaided nature make
provision. Indeed, the very commonness of this source of refined enjoyment
seems to have deprived it of half its value; and it was only in the infancy of
lands where all the earth was fair, that Greek and Roman humanity had
sympathy enough with the inanimate world to be alive to the charms of
rural and of mountain scenery. In later generations, when the glories of the
landscape had been heightened by plantation, and decorative architecture,
and other forms of picturesque improvement, the poets of Greece and Rome
were blinded by excess of light, and became, at last, almost insensible to
beauties that now, even in their degraded state, enchant every eye, except,
too often, those which a lifelong familiarity has dulled to their attractions.
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 carnelian 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 some of the 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. 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. 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,
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.
Only for the sense of landscape beauty did unaided nature make
provision. Indeed, the very commonness of this source of refined enjoyment
seems to have deprived it of half its value; and it was only in the infancy of
lands where all the earth was fair, that Greek and Roman humanity had
sympathy enough with the inanimate world to be alive to the charms of
rural and of mountain scenery. In later generations, when the glories of the
landscape had been heightened by plantation, and decorative architecture,
and other forms of picturesque improvement, the poets of Greece and Rome
were blinded by excess of light, and became, at last, almost insensible to
beauties that now, even in their degraded state, enchant every eye, except,
too often, those which a lifelong familiarity has dulled to their attractions.
Page 24
Physical Decay of the Territory of the Roman Empire,
and of other parts of the Old World.
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 of their whole extent—including
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
surrendered 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; 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
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
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
and of other parts of the Old World.
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 of their whole extent—including
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
surrendered 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; 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
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
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
Page 25
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, is now
completely exhausted of its 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
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, is now
completely exhausted of its 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
Page 26
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 Cæsars, 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.[1] Man cannot struggle at once against crushing oppression
and the destructive forces of inorganic nature. When both are combined
against him, he succumbs after a shorter or a 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.
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 internal commerce by absurd restrictions and unwise
regulations. 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.
[2]
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, 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.
New School of Geographers.
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 Cæsars, 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.[1] Man cannot struggle at once against crushing oppression
and the destructive forces of inorganic nature. When both are combined
against him, he succumbs after a shorter or a 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.
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 internal commerce by absurd restrictions and unwise
regulations. 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.
[2]
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, 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.
New School of Geographers.
Page 27
The labors of Humboldt, of Ritter, of Guyot and their followers, have
given to the science of geography a more philosophical, and, at the same
time, a more imaginative character than it had received from the hands of
their predecessors. Perhaps the most interesting field of speculation, thrown
open by the new school to the cultivators of this attractive study, is the
inquiry: how far external physical conditions, and especially the
configuration of the earth's surface, and the distribution, outline, and
relative position of land and water, have influenced the social life and social
progress of man.
Reaction of Man on Nature.
But, as we have seen, 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 far as I know, been made matter of special
observation, or of historical research by any scientific inquirer.[3] Indeed,
until the influence of physical geography 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 whether 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.[4]
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,[5] 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
given to the science of geography a more philosophical, and, at the same
time, a more imaginative character than it had received from the hands of
their predecessors. Perhaps the most interesting field of speculation, thrown
open by the new school to the cultivators of this attractive study, is the
inquiry: how far external physical conditions, and especially the
configuration of the earth's surface, and the distribution, outline, and
relative position of land and water, have influenced the social life and social
progress of man.
Reaction of Man on Nature.
But, as we have seen, 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 far as I know, been made matter of special
observation, or of historical research by any scientific inquirer.[3] Indeed,
until the influence of physical geography 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 whether 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.[4]
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,[5] 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
Page 28
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 influence
upon the physical conditions of the earth we inhabit.
Observation of Nature.
In these pages, as in all I have ever written or propose to write, 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.[6]
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,
and the sculptor, as well as to the common 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 it does not necessarily perceive what it reflects.
[7]
It is disputed whether the purely material sensibility of the eye is capable
of improvement and cultivation. It has been maintained by high authority,
that the natural acuteness of none of our sensuous faculties can 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 well be doubted, and it is agreed on all hands
that the power of multifarious perception and rapid discrimination may be
immensely increased by well-directed practice.[8] 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.
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 influence
upon the physical conditions of the earth we inhabit.
Observation of Nature.
In these pages, as in all I have ever written or propose to write, 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.[6]
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,
and the sculptor, as well as to the common 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 it does not necessarily perceive what it reflects.
[7]
It is disputed whether the purely material sensibility of the eye is capable
of improvement and cultivation. It has been maintained by high authority,
that the natural acuteness of none of our sensuous faculties can 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 well be doubted, and it is agreed on all hands
that the power of multifarious perception and rapid discrimination may be
immensely increased by well-directed practice.[8] 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.
Page 29
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 such broad and general views as are 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 presented, is not only
a very important, but a very interesting field of inquiry.
Cosmical and Geological Influences.
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 condition 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.
Geographical Influence of Man.
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 such broad and general views as are 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 presented, is not only
a very important, but a very interesting field of inquiry.
Cosmical and Geological Influences.
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 condition 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.
Geographical Influence of Man.
Page 30
But it is certain that man has done much to mould the form of the earth's
surface, though we cannot always distinguish between the results of his
action and the effects of purely geological causes; that the destruction of the
forests, the drainage of lakes and marshes, and the operations of rural
husbandry and industrial art have 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 compensated by
each other, or by still obscurer influences; and, finally, 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 action, greatly changed in numerical
proportion, sometimes much modified in form and product, and sometimes
entirely extirpated.
The physical revolutions thus wrought by man have not all been
destructive to human interests. 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 made 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
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 conquered, or
rather compensated, the rigors of climate, and 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.
These changes for evil and for good have not been caused by great
natural revolutions of the globe, nor are they by any means attributable
wholly to the moral and physical action or inaction of the peoples, or, in all
surface, though we cannot always distinguish between the results of his
action and the effects of purely geological causes; that the destruction of the
forests, the drainage of lakes and marshes, and the operations of rural
husbandry and industrial art have 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 compensated by
each other, or by still obscurer influences; and, finally, 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 action, greatly changed in numerical
proportion, sometimes much modified in form and product, and sometimes
entirely extirpated.
The physical revolutions thus wrought by man have not all been
destructive to human interests. 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 made 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
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 conquered, or
rather compensated, the rigors of climate, and 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.
These changes for evil and for good have not been caused by great
natural revolutions of the globe, nor are they by any means attributable
wholly to the moral and physical action or inaction of the peoples, or, in all
Page 31
cases, even of the races that now inhabit these respective regions. They are
products of a complication of conflicting or coincident forces, acting
through a long series of generations; here, improvidence, wastefulness, and
wanton violence; there, foresight and wisely guided persevering industry.
So far as they are purely the calculated and desired results of those simple
and familiar operations of agriculture and of social life which are as
universal as civilization—the removal of the forests which covered the soil
required for the cultivation of edible fruits, the drying of here and there a
few acres too moist for profitable husbandry, by draining off the surface
waters, the substitution of domesticated and nutritious for wild and
unprofitable vegetable growths, the construction of roads and canals and
artificial harbors—they belong to the sphere of rural, commercial, and
political economy more properly than to geography, and hence are but
incidentally embraced within the range of our present inquiries, which
concern physical, not financial balances. I propose to examine only the
greater, more permanent, and more comprehensive mutations which man
has produced, and is producing, in earth, sea, and sky, sometimes, indeed,
with conscious purpose, but for the most part, as unforeseen though natural
consequences of acts performed for narrower and more immediate ends.
The exact measurement of the geographical changes hitherto thus
effected is, as I have hinted, 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 Meteorological Knowledge.
The invention of measures of heat, and of atmospheric moisture,
pressure, and precipitation, is extremely recent. Hence, ancient physicists
products of a complication of conflicting or coincident forces, acting
through a long series of generations; here, improvidence, wastefulness, and
wanton violence; there, foresight and wisely guided persevering industry.
So far as they are purely the calculated and desired results of those simple
and familiar operations of agriculture and of social life which are as
universal as civilization—the removal of the forests which covered the soil
required for the cultivation of edible fruits, the drying of here and there a
few acres too moist for profitable husbandry, by draining off the surface
waters, the substitution of domesticated and nutritious for wild and
unprofitable vegetable growths, the construction of roads and canals and
artificial harbors—they belong to the sphere of rural, commercial, and
political economy more properly than to geography, and hence are but
incidentally embraced within the range of our present inquiries, which
concern physical, not financial balances. I propose to examine only the
greater, more permanent, and more comprehensive mutations which man
has produced, and is producing, in earth, sea, and sky, sometimes, indeed,
with conscious purpose, but for the most part, as unforeseen though natural
consequences of acts performed for narrower and more immediate ends.
The exact measurement of the geographical changes hitherto thus
effected is, as I have hinted, 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 Meteorological Knowledge.
The invention of measures of heat, and of atmospheric moisture,
pressure, and precipitation, is extremely recent. Hence, ancient physicists
Page 32
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 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.
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, containing the implements of the occupants,
remains of their food, and other relics of human life; to the curious
revelations of the Kjökkenmöddinger, or heaps of kitchen refuse, in
Denmark, 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 shores of the latter,
by excavations in inhabited mounds which were, perhaps, raised before the
period of the Roman Empire. These remains are memorials of races which
have left no written records, because they perished before the historical
period of the countries they occupied began. 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
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 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.
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, containing the implements of the occupants,
remains of their food, and other relics of human life; to the curious
revelations of the Kjökkenmöddinger, or heaps of kitchen refuse, in
Denmark, 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 shores of the latter,
by excavations in inhabited mounds which were, perhaps, raised before the
period of the Roman Empire. These remains are memorials of races which
have left no written records, because they perished before the historical
period of the countries they occupied began. 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
Page 33
their age; and from the vegetation, remains of 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. 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;"[9] and the North
American Indians now manufacture and use weapons of stone, and even of
glass, chipping them in the latter case out of the bottoms of thick bottles,
with great facility.[10]
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
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
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. 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;"[9] and the North
American Indians now manufacture and use weapons of stone, and even of
glass, chipping them in the latter case out of the bottoms of thick bottles,
with great facility.[10]
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
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
Page 34
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 that the conditions of temperature and humidity which they
required twenty centuries ago were different from those at present
demanded for their advantageous cultivation.[11]
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,[12] 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.[13] In other cases, from injudicious
husbandry, or the diversion or choking up of natural watercourses, 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 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.[14] We are very imperfectly acquainted with the present
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 that the conditions of temperature and humidity which they
required twenty centuries ago were different from those at present
demanded for their advantageous cultivation.[11]
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,[12] 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.[13] In other cases, from injudicious
husbandry, or the diversion or choking up of natural watercourses, 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 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.[14] We are very imperfectly acquainted with the present
Page 35
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
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 changes of station upon the results of
observations of temperature and precipitation. A thermometer removed but
a few hundred yards from its first position differs not unfrequently five,
sometimes even ten degrees in its readings; 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 level of the rain-
gauge is a point of much consequence in making estimates from its
measurements. The data from which results have been deduced with respect
to the hygrometrical and thermometrical conditions, 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.[15]
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
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
of the ground, the degree of freedom or obstruction of the surface, the
composition and density of the soil, upon which its permeability by water
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
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 changes of station upon the results of
observations of temperature and precipitation. A thermometer removed but
a few hundred yards from its first position differs not unfrequently five,
sometimes even ten degrees in its readings; 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 level of the rain-
gauge is a point of much consequence in making estimates from its
measurements. The data from which results have been deduced with respect
to the hygrometrical and thermometrical conditions, 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.[15]
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
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
of the ground, the degree of freedom or obstruction of the surface, the
composition and density of the soil, upon which its permeability by water
Page 36
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 and the
superficial flow from very small geographical basins 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
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.
Mechanical Effects produced by Man on the Surface of
the Earth more easily ascertainable.
In investigating the mechanical effects of human action on superficial
geography, we are treading on safer ground, and dealing with much less
subtile phenomena, less intractable elements. Great physical changes can, in
some cases, be positively shown, in some almost certainly inferred, to have
been produced by the operations of rural industry, and by the labors of man
in other spheres of material effort; and hence, in this most important part of
its temperature, the dryness or saturation of the subsoil, vary at
comparatively short distances; and though the precipitation upon and the
superficial flow from very small geographical basins 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
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.
Mechanical Effects produced by Man on the Surface of
the Earth more easily ascertainable.
In investigating the mechanical effects of human action on superficial
geography, we are treading on safer ground, and dealing with much less
subtile phenomena, less intractable elements. Great physical changes can, in
some cases, be positively shown, in some almost certainly inferred, to have
been produced by the operations of rural industry, and by the labors of man
in other spheres of material effort; and hence, in this most important part of
Page 37
our subject, we can arrive at many positive generalizations, and obtain
practical results of no small economical value.
Importance and Possibility of 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 soils 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.
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
practical results of no small economical value.
Importance and Possibility of 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 soils 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.
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
Page 38
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.
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 reached which, without the action of man, 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;[16] and
whenever the Indian, in consequence of war or the 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.[17] 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
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.
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 reached which, without the action of man, 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;[16] and
whenever the Indian, in consequence of war or the 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.[17] 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
Page 39
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. 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 considerable
permanent change was produced by them. I refer to the action of beavers
and of fallen trees in producing bogs,[18] and of smaller animals, insects,
and birds, in destroying the woods. Bogs are less numerous and extensive in
the Northern States of the American union, because the natural inclination
of the surface favors drainage; but they are more frequent, and cover more
ground, in the Southern States, for the opposite reason.[19] They generally
originate in the checking of watercourses by the falling of timber, or of
earth and rocks, across their channels. If the impediment thus created 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 semi-
aquatic 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.[20] 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 reëstablished.
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, but he prefers to owe
his pond to his own ingenuity and toil. The reservoir once constructed, its
inhabitants rapidly multiply, and as its harvests of pond lilies, and other
aquatic plants on which this quadruped feeds in winter, become too small
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. 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 considerable
permanent change was produced by them. I refer to the action of beavers
and of fallen trees in producing bogs,[18] and of smaller animals, insects,
and birds, in destroying the woods. Bogs are less numerous and extensive in
the Northern States of the American union, because the natural inclination
of the surface favors drainage; but they are more frequent, and cover more
ground, in the Southern States, for the opposite reason.[19] They generally
originate in the checking of watercourses by the falling of timber, or of
earth and rocks, across their channels. If the impediment thus created 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 semi-
aquatic 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.[20] 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 reëstablished.
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, but he prefers to owe
his pond to his own ingenuity and toil. The reservoir once constructed, its
inhabitants rapidly multiply, and as its harvests of pond lilies, and other
aquatic plants on which this quadruped feeds in winter, become too small
Page 40
for the growing population, the beaver metropolis 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.
In countries somewhat further advanced in civilization than those
occupied by the North American Indians, as in mediæval Ireland, the
formation of bogs may be commenced by the neglect of man to remove,
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 thus have fallen to the ground, only one by one, as natural
decay brought them down.[21] 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. 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.[22] 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
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.
In countries somewhat further advanced in civilization than those
occupied by the North American Indians, as in mediæval Ireland, the
formation of bogs may be commenced by the neglect of man to remove,
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 thus have fallen to the ground, only one by one, as natural
decay brought them down.[21] 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. 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.[22] 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
Page 41
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 drowsy 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.[23]
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 subject to change only from geological influences so slow in their
operation that the geographical conditions may be regarded as constant and
immutable. These arrangements of nature it is, in most cases, highly
desirable substantially to maintain, when such regions become the seat of
organized commonwealths. It is, therefore, a matter of the first importance,
that, in commencing the process of fitting them for permanent civilized
occupation, the transforming operations should be so conducted as not
unnecessarily to derange and destroy what, in too many cases, it is beyond
the power of man to rectify or restore.
Restoration of Disturbed Harmonies.
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
fury of torrents, and bringing back the surface drainage to its primitive
narrow channels; and in drying deadly morasses by opening the natural
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 drowsy 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.[23]
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 subject to change only from geological influences so slow in their
operation that the geographical conditions may be regarded as constant and
immutable. These arrangements of nature it is, in most cases, highly
desirable substantially to maintain, when such regions become the seat of
organized commonwealths. It is, therefore, a matter of the first importance,
that, in commencing the process of fitting them for permanent civilized
occupation, the transforming operations should be so conducted as not
unnecessarily to derange and destroy what, in too many cases, it is beyond
the power of man to rectify or restore.
Restoration of Disturbed Harmonies.
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
fury of torrents, and bringing back the surface drainage to its primitive
narrow channels; and in drying deadly morasses by opening the natural
Page 42
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.
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 æons 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.
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.
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 æons 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 43
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 born of her womb and submissive 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.[24]
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 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 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 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
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 born of her womb and submissive 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.[24]
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 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 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 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
Page 44
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,[25] 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 rather 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.[26]
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,[25] 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 rather 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.[26]
Page 45
Human and Brute Action Compared.
It has been 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 appears to me to differ in
essential character, because, though it is often followed by unforeseen and
undesired results, yet it is nevertheless guided by a self-conscious and
intelligent 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 their bark or use
them in the construction of his habitation. Human differs from brute action,
too, in its influence upon the material world, because it is not controlled by
natural compensations and balances. Natural arrangements, once disturbed
by man, are not restored until he retires from the field, and leaves free scope
to spontaneous recuperative energies; the wounds he inflicts upon the
material creation are not healed until he withdraws the arm that gave the
blow. On the other hand, I am not aware of any evidence that wild animals
have ever destroyed the smallest forest, extirpated any organic species or
modified its natural character, occasioned any permanent change of
terrestrial surface, or produced any disturbance of physical conditions
which nature has not, of herself, repaired without the expulsion of the
animal that had caused it.[27]
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.[28] 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
It has been 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 appears to me to differ in
essential character, because, though it is often followed by unforeseen and
undesired results, yet it is nevertheless guided by a self-conscious and
intelligent 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 their bark or use
them in the construction of his habitation. Human differs from brute action,
too, in its influence upon the material world, because it is not controlled by
natural compensations and balances. Natural arrangements, once disturbed
by man, are not restored until he retires from the field, and leaves free scope
to spontaneous recuperative energies; the wounds he inflicts upon the
material creation are not healed until he withdraws the arm that gave the
blow. On the other hand, I am not aware of any evidence that wild animals
have ever destroyed the smallest forest, extirpated any organic species or
modified its natural character, occasioned any permanent change of
terrestrial surface, or produced any disturbance of physical conditions
which nature has not, of herself, repaired without the expulsion of the
animal that had caused it.[27]
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.[28] 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
Page 46
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 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.[29]
Physical Improvement.
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 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.[29]
Physical Improvement.
Page 47
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;[30]
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.
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, and even of a substance so harmless,
unresisting, and inert as cotton, nothing in the way of mechanical
achievement seems 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.
I must therefore be understood to mean only, that no agencies now
known to man and directed by him seem adequate 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. But among the mysteries
which science is yet 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 greater natural forces, which the action of the elements puts
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;[30]
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.
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, and even of a substance so harmless,
unresisting, and inert as cotton, nothing in the way of mechanical
achievement seems 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.
I must therefore be understood to mean only, that no agencies now
known to man and directed by him seem adequate 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. But among the mysteries
which science is yet 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 greater natural forces, which the action of the elements puts
Page 48
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,
[31]
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 rugged 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.[32]
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 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 toward the rising instead of the setting sun.
But changes like these must await great political and moral revolutions
in the governments and peoples by whom those regions are now possessed,
a command of pecuniary and of mechanical means not at present enjoyed
by those 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 mean time, the American continent, Southern Africa,
Australia, 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.
Arrest of Physical Decay of New Countries.
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,
[31]
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 rugged 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.[32]
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 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 toward the rising instead of the setting sun.
But changes like these must await great political and moral revolutions
in the governments and peoples by whom those regions are now possessed,
a command of pecuniary and of mechanical means not at present enjoyed
by those 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 mean time, the American continent, Southern Africa,
Australia, 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.
Arrest of Physical Decay of New Countries.
Page 49
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 been already done in the various
processes by which man seeks to subjugate the virgin earth; and many
provinces, first trodden by the homo sapiens Europæ 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 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.
Forms and Formations most liable to Physical
Degradation.
The character and extent of the evils under consideration depend very
much on climate and the natural forms and constitution of surface. 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 substantially 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
foreign lands by European emigrants extends, great, and, it is to be feared,
sometimes irreparable, injury has been already done in the various
processes by which man seeks to subjugate the virgin earth; and many
provinces, first trodden by the homo sapiens Europæ 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 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.
Forms and Formations most liable to Physical
Degradation.
The character and extent of the evils under consideration depend very
much on climate and the natural forms and constitution of surface. 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 substantially 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
Page 50
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.
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 the year is divided into a wet and a dry
period, as is the case throughout a great part of the Ottoman empire, and,
more or less strictly, the whole Mediterranean basin. 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 Mœsia, the
comparatively inhospitable homes of barbarous races, who, in the days of
the Cæsars, 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.[33]
In mountainous countries, on the other hand, 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 confined 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.[34]
Physical Decay of New Countries.
as in many parts of the continents of South America and of Africa.
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 the year is divided into a wet and a dry
period, as is the case throughout a great part of the Ottoman empire, and,
more or less strictly, the whole Mediterranean basin. 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 Mœsia, the
comparatively inhospitable homes of barbarous races, who, in the days of
the Cæsars, 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.[33]
In mountainous countries, on the other hand, 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 confined 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.[34]
Physical Decay of New Countries.
Page 51
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, 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 is, perhaps, the country from which we have a right to expect
the fullest elucidation of these difficult and disputable problems. Its
colonization did not commence until the physical sciences had become
matter of almost universal attention, and is, indeed, so recent that the
memory of living men embraces the principal epochs of its history; the
peculiarities of its fauna, its flora, and its geology are such as to have
excited for it the liveliest interest of the votaries of natural science; its
mines have given its 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 meadow 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
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, 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 is, perhaps, the country from which we have a right to expect
the fullest elucidation of these difficult and disputable problems. Its
colonization did not commence until the physical sciences had become
matter of almost universal attention, and is, indeed, so recent that the
memory of living men embraces the principal epochs of its history; the
peculiarities of its fauna, its flora, and its geology are such as to have
excited for it the liveliest interest of the votaries of natural science; its
mines have given its 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 meadow 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
Page 52
thermometrical readings, but there remain some interesting physical records
from the early days of the colonies,[35] 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 and contingent,
of man's 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 multiplication of the points of meteorological registry,[36] 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,
or the drainage of lakes and swamps, or other great works of rural
improvement, are going on or meditated, should be especially drawn not
only to revolutions in atmospheric temperature 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 keeps pace
with, and sometimes even precedes, 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.[37]
from the early days of the colonies,[35] 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 and contingent,
of man's 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 multiplication of the points of meteorological registry,[36] 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,
or the drainage of lakes and swamps, or other great works of rural
improvement, are going on or meditated, should be especially drawn not
only to revolutions in atmospheric temperature 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 keeps pace
with, and sometimes even precedes, 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.[37]
Page 53
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 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.
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 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.
Page 54
CHAPTER II.
T R A N S F E R , M O D I F I C AT I O N ,
A N D E X T I R PAT I O N O F
V E G E TA B L E A N D O F A N I M A L
SPECIES.
MODERN GEOGRAPHY EMBRACES ORGANIC LIFE—TRANSFER OF VEGETABLE LIFE—
FOREIGN PLANTS GROWN IN THE UNITED STATES—AMERICAN PLANTS GROWS IN
EUROPE—MODES OF INTRODUCTION OF FOREIGN PLANTS—VEGETABLES, HOW
AFFECTED BY TRANSFER TO FOREIGN SOILS—EXTIRPATION OF VEGETABLES—
ORIGIN OF DOMESTIC PLANTS—ORGANIC LIFE AS A GEOLOGICAL AND
GEOGRAPHICAL AGENCY—ORIGIN AND TRANSFER OF DOMESTIC ANIMALS—
EXTIRPATION OF ANIMALS—NUMBERS OF BIRDS IN THE UNITED STATES—BIRDS AS
SOWERS AND CONSUMERS OF SEEDS, AND AS DESTROYERS OF INSECTS—
DIMINUTION AND EXTIRPATION OF BIRDS—INTRODUCTION OF BIRDS—UTILITY OF
INSECTS AND WORMS—INTRODUCTION OF INSECTS—DESTRUCTION OF INSECTS—
REPTILES—DESTRUCTION OF FISH—INTRODUCTION AND BREEDING OF FISH—
EXTIRPATION OF AQUATIC ANIMALS—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, 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 even wild beasts, restorative powers. The rushing waters
sweep down earth from the uplands; in the first moment of repose,
vegetation seeks to reëstablish itself on the bared surface, and, by the slow
deposit of its decaying products, to raise again the soil which the torrent had
T R A N S F E R , M O D I F I C AT I O N ,
A N D E X T I R PAT I O N O F
V E G E TA B L E A N D O F A N I M A L
SPECIES.
MODERN GEOGRAPHY EMBRACES ORGANIC LIFE—TRANSFER OF VEGETABLE LIFE—
FOREIGN PLANTS GROWN IN THE UNITED STATES—AMERICAN PLANTS GROWS IN
EUROPE—MODES OF INTRODUCTION OF FOREIGN PLANTS—VEGETABLES, HOW
AFFECTED BY TRANSFER TO FOREIGN SOILS—EXTIRPATION OF VEGETABLES—
ORIGIN OF DOMESTIC PLANTS—ORGANIC LIFE AS A GEOLOGICAL AND
GEOGRAPHICAL AGENCY—ORIGIN AND TRANSFER OF DOMESTIC ANIMALS—
EXTIRPATION OF ANIMALS—NUMBERS OF BIRDS IN THE UNITED STATES—BIRDS AS
SOWERS AND CONSUMERS OF SEEDS, AND AS DESTROYERS OF INSECTS—
DIMINUTION AND EXTIRPATION OF BIRDS—INTRODUCTION OF BIRDS—UTILITY OF
INSECTS AND WORMS—INTRODUCTION OF INSECTS—DESTRUCTION OF INSECTS—
REPTILES—DESTRUCTION OF FISH—INTRODUCTION AND BREEDING OF FISH—
EXTIRPATION OF AQUATIC ANIMALS—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, 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 even wild beasts, restorative powers. The rushing waters
sweep down earth from the uplands; in the first moment of repose,
vegetation seeks to reëstablish itself on the bared surface, and, by the slow
deposit of its decaying products, to raise again the soil which the torrent had
Page 55
lowered. So important an element of reconstruction is 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 the geography 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 small 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 vegetables, which have taken the place of trees, unquestionably
perform many of the same functions. They radiate heat, they condense the
humidity of the atmosphere, they act upon the chemical constitution 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 of moisture
from its surface by wind and sun.[38] At a certain stage of growth, grass land
is probably a more energetic radiator and condenser than even the forest,
but this powerful action is exerted, in its full intensity, for a few days 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.
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 the geography 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 small 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 vegetables, which have taken the place of trees, unquestionably
perform many of the same functions. They radiate heat, they condense the
humidity of the atmosphere, they act upon the chemical constitution 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 of moisture
from its surface by wind and sun.[38] At a certain stage of growth, grass land
is probably a more energetic radiator and condenser than even the forest,
but this powerful action is exerted, in its full intensity, for a few days 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.
Page 56
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
this subject may pertinently be introduced here. Most of the fruit trees
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 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.[39] 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 all introduced by European colonists.[40]
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 many others, the plants or animals from which
they are derived have been introduced by man into the regions now
remarkable for their most successful cultivation, and that, too, in
comparatively recent times, or, in other words, within two or three
centuries.
Foreign Plants grown in the United States.
According to Bigelow, the United States had, on the first of June, 1860,
in round numbers, 163,000,000 acres of improved land, the quantity having
been increased by 50,000,000 acres within the ten years next preceding.[41]
Not to mention less important crops, this land produced, in the year ending
on the day last mentioned, in round numbers, 171,000,000 bushels of
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
this subject may pertinently be introduced here. Most of the fruit trees
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 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.[39] 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 all introduced by European colonists.[40]
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 many others, the plants or animals from which
they are derived have been introduced by man into the regions now
remarkable for their most successful cultivation, and that, too, in
comparatively recent times, or, in other words, within two or three
centuries.
Foreign Plants grown in the United States.
According to Bigelow, the United States had, on the first of June, 1860,
in round numbers, 163,000,000 acres of improved land, the quantity having
been increased by 50,000,000 acres within the ten years next preceding.[41]
Not to mention less important crops, this land produced, in the year ending
on the day last mentioned, in round numbers, 171,000,000 bushels of
Page 57
wheat, 21,000,000 bushels of rye, 172,000,000 bushels of oats, 15,000,000
bushels of pease and beans, 16,000,000 bushels of barley, orchard fruits to
the value of $20,000,000, 900,000 bushels of cloverseed, 900,000 bushels
of other grass seed, 104,000 tons of hemp, 4,000,000 pounds of flax, and
600,000 pounds 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, 187,000,000
pounds of rice, 18,000,000 bushels of buckwheat, 2,075,000,000 pounds of
ginned cotton,[42] 302,000,000 pounds of cane sugar, 16,000,000 gallons of
cane molasses, 7,000,000 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, 830,000,000 bushels of
Indian corn or maize, 429,000,000 pounds of tobacco, 110,000,000 bushels
of potatoes, 42,000,000 bushels of sweet potatoes, 39,000,000 pounds of
maple sugar, and 2,000,000 gallons of maple molasses. To all this we are to
add 19,000,000 tons of hay, produced partly by new, partly by long known,
partly by exotic, partly by native herbs and grasses, an incalculable quantity
of garden vegetables, chiefly of European or Asiatic origin, and many minor
agricultural products.
The weight of this harvest of a year would be not less than 60,000,000
tons—which is eleven times the tonnage of all the shipping of the United
States at the close of the year 1861—and, with the exception of the maple
sugar, the maple molasses, and the products of the Western prairie lands and
some small Indian clearings, it was all 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, the coffee plant, the orange and the lemon,[43] 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.
bushels of pease and beans, 16,000,000 bushels of barley, orchard fruits to
the value of $20,000,000, 900,000 bushels of cloverseed, 900,000 bushels
of other grass seed, 104,000 tons of hemp, 4,000,000 pounds of flax, and
600,000 pounds 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, 187,000,000
pounds of rice, 18,000,000 bushels of buckwheat, 2,075,000,000 pounds of
ginned cotton,[42] 302,000,000 pounds of cane sugar, 16,000,000 gallons of
cane molasses, 7,000,000 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, 830,000,000 bushels of
Indian corn or maize, 429,000,000 pounds of tobacco, 110,000,000 bushels
of potatoes, 42,000,000 bushels of sweet potatoes, 39,000,000 pounds of
maple sugar, and 2,000,000 gallons of maple molasses. To all this we are to
add 19,000,000 tons of hay, produced partly by new, partly by long known,
partly by exotic, partly by native herbs and grasses, an incalculable quantity
of garden vegetables, chiefly of European or Asiatic origin, and many minor
agricultural products.
The weight of this harvest of a year would be not less than 60,000,000
tons—which is eleven times the tonnage of all the shipping of the United
States at the close of the year 1861—and, with the exception of the maple
sugar, the maple molasses, and the products of the Western prairie lands and
some small Indian clearings, it was all 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, the coffee plant, the orange and the lemon,[43] 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.
Page 58
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.[44] 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;[45] but the alleged occurrence of pipe-like objects in 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.
Modes of Introduction of Foreign Plants.
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;
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.[46] 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.
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.[44] 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;[45] but the alleged occurrence of pipe-like objects in 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.
Modes of Introduction of Foreign Plants.
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;
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.[46] 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.
Page 59
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. At the present time its flora numbers seven hundred
and fifty species. 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 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 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.[47]
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 seven hundred new species which have found their way to St.
Helena within three centuries and a half, were certainly not all, or even 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 weeds that grow among the cereal grains,
the pests of the kitchen garden, are the same in America as in Europe.[48]
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 just opened by the caravan of the settler.[49]
The hortus siccus of a botanist may accidentally sow seeds from the foot of
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. At the present time its flora numbers seven hundred
and fifty species. 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 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 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.[47]
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 seven hundred new species which have found their way to St.
Helena within three centuries and a half, were certainly not all, or even 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 weeds that grow among the cereal grains,
the pests of the kitchen garden, are the same in America as in Europe.[48]
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 just opened by the caravan of the settler.[49]
The hortus siccus of a botanist may accidentally sow seeds from the foot of
Page 60
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 were 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
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.[50] 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
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.[51] The Canada thistle, Erigeron Canadense,
is said to have sprung up in Europe, two hundred years ago, from a seed
which dropped out of the stuffed skin of a bird.[52]
Vegetables, how affected by Transfer to Foreign Soils.
Vegetables, naturalized abroad either by accident or design, sometimes
exhibit a greatly increased luxuriance of growth. 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
very many cultivated vegetables lose their vitality in two or three years, and
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 were 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
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.[50] 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
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.[51] The Canada thistle, Erigeron Canadense,
is said to have sprung up in Europe, two hundred years ago, from a seed
which dropped out of the stuffed skin of a bird.[52]
Vegetables, how affected by Transfer to Foreign Soils.
Vegetables, naturalized abroad either by accident or design, sometimes
exhibit a greatly increased luxuriance of growth. 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
very many cultivated vegetables lose their vitality in two or three years, and
Page 61
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 dominion of man.[53]
Not only is the wild plant much hardier than the domesticated
vegetable, but 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,[54] he has been
known to press forward along the shaft of the spear which was transpiercing
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 outstrips 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.
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 has been made
practicable, through the invention of Ward's airtight glass cases. It is by this
means that large numbers of the trees which produce the Jesuit's bark have
been successfully transplanted from America to the British possessions in
the East, where it is hoped they will become fully naturalized.
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 dominion of man.[53]
Not only is the wild plant much hardier than the domesticated
vegetable, but 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,[54] he has been
known to press forward along the shaft of the spear which was transpiercing
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 outstrips 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.
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 has been made
practicable, through the invention of Ward's airtight glass cases. It is by this
means that large numbers of the trees which produce the Jesuit's bark have
been successfully transplanted from America to the British possessions in
the East, where it is hoped they will become fully naturalized.
Page 62
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 satisfactorily 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.[55] 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
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 worth
remarking that no insect depends upon it for food or shelter, or aids in its
fructification, no bird feeds upon its berries—the latter a circumstance of
some importance, because the tree hence wants one 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 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
Lamentable as are the evils produced by the too general felling of the
woods in the Old World, I believe it does not satisfactorily 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.[55] 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
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 worth
remarking that no insect depends upon it for food or shelter, or aids in its
fructification, no bird feeds upon its berries—the latter a circumstance of
some importance, because the tree hence wants one 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 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
Page 63
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.[56]
Origin of Domestic Plants.
One of the most important, and, at the same time, most difficult
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 Ægilops 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
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.[56]
Origin of Domestic Plants.
One of the most important, and, at the same time, most difficult
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 Ægilops 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
Page 64
succession of changes, from some wild plant not now much resembling it.
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. 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.[57] 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.[58]
Organic Life as a Geological and Geographical
Agency.
The quantitative value of organic 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 plant or 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 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.[59] 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 recent discovery of works of
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. 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.[57] 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.[58]
Organic Life as a Geological and Geographical
Agency.
The quantitative value of organic 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 plant or 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 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.[59] 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 recent discovery of works of
Page 65
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 alleged 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.[60] 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
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.
The influence of wild quadrupeds upon vegetable life has 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.[61] Few
if any of them 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. 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
same time and by the same agency which buried these latter—not to speak
of alleged 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.[60] 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
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.
The influence of wild quadrupeds upon vegetable life has 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.[61] Few
if any of them 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. 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
Page 66
domestic congeners are eminently so. 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.
Number of Quadrupeds in the United States.
Civilization is so intimately associated with, if not dependent upon,
certain inferior forms of animal life, 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 transported
by every emigrant colony, and they soon multiply to numbers very far
exceeding those of the wild genera most nearly corresponding to them.[62]
According to the census of the United States for 1860,[63] the total number
of horses in all the States of the American Union, was, in round numbers,
7,300,000; of asses and mules, 1,300,000; of the ox tribe, 29,000,000;[64] of
sheep, 25,000,000; and of swine, 39,000,000. The only 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 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 ten years on the great plains near the
Upper Missouri, at not less than 200,000, and yet the range occupied by this
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.
Number of Quadrupeds in the United States.
Civilization is so intimately associated with, if not dependent upon,
certain inferior forms of animal life, 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 transported
by every emigrant colony, and they soon multiply to numbers very far
exceeding those of the wild genera most nearly corresponding to them.[62]
According to the census of the United States for 1860,[63] the total number
of horses in all the States of the American Union, was, in round numbers,
7,300,000; of asses and mules, 1,300,000; of the ox tribe, 29,000,000;[64] of
sheep, 25,000,000; and of swine, 39,000,000. The only 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 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 ten years on the great plains near the
Upper Missouri, at not less than 200,000, and yet the range occupied by this
Page 67
animal is now very much smaller in area than it was when the whites first
established themselves on the prairies.[65] 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. 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,[66] 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.
Origin and Transfer of Domestic Quadrupeds.
Of the origin of our domestic animals, we know historically nothing,
because their domestication belongs to the ages which preceded written
history; 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 annalists 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; that he was
unknown to the Carthaginians until after the downfall of their
commonwealth; and that his first appearance in Western Africa is more
established themselves on the prairies.[65] 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. 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,[66] 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.
Origin and Transfer of Domestic Quadrupeds.
Of the origin of our domestic animals, we know historically nothing,
because their domestication belongs to the ages which preceded written
history; 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 annalists 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; that he was
unknown to the Carthaginians until after the downfall of their
commonwealth; and that his first appearance in Western Africa is more
Page 68
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.[67] 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. America had no
domestic quadruped but a species of dog, the lama tribe, and, to a certain
extent, the bison or buffalo.[68] 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. The yak, or
Tartary ox, seems to thrive in France, and success has attended the recent
efforts to introduce the South American alpaca into Europe.
Extirpation of 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 even 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 quadruped with more abundant food. 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
the Northern shores of the Black Sea, by the Goths, in the third or fourth
century.[67] 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. America had no
domestic quadruped but a species of dog, the lama tribe, and, to a certain
extent, the bison or buffalo.[68] 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. The yak, or
Tartary ox, seems to thrive in France, and success has attended the recent
efforts to introduce the South American alpaca into Europe.
Extirpation of 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 even 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 quadruped with more abundant food. 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
Page 69
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 fine 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 this animal—whose habits, as we have
seen, 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, some 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
British wild ox exists only 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. 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 Crusades.[69] Two
large graminivorous or browsing quadrupeds, the ur and the schelk, once
common in Germany, are utterly extinct, the eland and the auerochs nearly
so. The Nibelungen-Lied, which, in the oldest form preserved to us, dates
from about the year 1,200, 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.[70]
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
footed destroyer by augmenting the supply of his nourishment. So long as
the fur of the beaver was extensively employed as a material for fine 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 this animal—whose habits, as we have
seen, 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, some 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
British wild ox exists only 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. 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 Crusades.[69] Two
large graminivorous or browsing quadrupeds, the ur and the schelk, once
common in Germany, are utterly extinct, the eland and the auerochs nearly
so. The Nibelungen-Lied, which, in the oldest form preserved to us, dates
from about the year 1,200, 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.[70]
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
Page 70
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 Schönbrunn, 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.
Number of Birds in the United States.
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[71] 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
numerous as once were 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.[72] 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 astonish
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.
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 Schönbrunn, 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.
Number of Birds in the United States.
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[71] 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
numerous as once were 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.[72] 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 astonish
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.
Page 71
Birds as Sowers and Consumers of Seeds, and as
Destroyers of Insects.
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,[73] and thus the occurrence of isolated
plants in situations where their presence cannot otherwise well be
explained, is easily accounted for. 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, 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.
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, larvæ, and fly of
Destroyers of Insects.
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,[73] and thus the occurrence of isolated
plants in situations where their presence cannot otherwise well be
explained, is easily accounted for. 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, 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.
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, larvæ, and fly of
Page 72
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 New England, 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.[74] On this subject, we have much other evidence besides that
derived from dissection. Direct 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
larvæ, 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 grasshoppers 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.[75] 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
This fact has been so well established by the examination of the stomachs
of great numbers of birds in Europe and New England, 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.[74] On this subject, we have much other evidence besides that
derived from dissection. Direct 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
larvæ, 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 grasshoppers 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.[75] 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
Page 73
that swarm in the lowlands; they have revoked the decree of banishment,
recalled in haste this valiant militia, which, though deficient in discipline, is
nevertheless the salvation of the country.[76]
"Not long since, in the neighborhood of Rouen and in the valley of
Monville, the blackbird was for some time proscribed. The beetles profited
well by this proscription; their larvæ, 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."
Diminution and Extirpation of Birds.
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
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 French Revolution removed 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 all game worth killing, drives the
recalled in haste this valiant militia, which, though deficient in discipline, is
nevertheless the salvation of the country.[76]
"Not long since, in the neighborhood of Rouen and in the valley of
Monville, the blackbird was for some time proscribed. The beetles profited
well by this proscription; their larvæ, 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."
Diminution and Extirpation of Birds.
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
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 French Revolution removed 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 all game worth killing, drives the
Page 74
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 farmers of Crawley are forbidden to follow
higher game, they will suicidally revenge themselves by destroying the
sparrows 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.[77]
Birds are less hardy in constitution, they possess less facility of
accommodation,[78] and they are more severely affected by climatic excess
than quadrupeds. Besides, they generally want the 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
of nestlings, and the parent often perishes with her progeny while brooding
over it in the vain effort to protect it.[79] The great proportional numbers of
birds, their migratory habits, and the ease with which 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.[80]
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
the skill implied in the various arts of the sportsman who devotes himself to
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 farmers of Crawley are forbidden to follow
higher game, they will suicidally revenge themselves by destroying the
sparrows 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.[77]
Birds are less hardy in constitution, they possess less facility of
accommodation,[78] and they are more severely affected by climatic excess
than quadrupeds. Besides, they generally want the 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
of nestlings, and the parent often perishes with her progeny while brooding
over it in the vain effort to protect it.[79] The great proportional numbers of
birds, their migratory habits, and the ease with which 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.[80]
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
the skill implied in the various arts of the sportsman who devotes himself to
Page 75
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 two or three fragments of 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 our boasted modern
civilization is guiltless of one or two sins of extermination which have been
committed in recent ages. New Zealand formerly possessed three species of
dinornis, one of which, called moa by the islanders, was much 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 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
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 two or three fragments of 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 our boasted modern
civilization is guiltless of one or two sins of extermination which have been
committed in recent ages. New Zealand formerly possessed three species of
dinornis, one of which, called moa by the islanders, was much 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 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
Page 76
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.[81] The ostrich is mentioned by all the old travellers, as common
on the Isthmus of Suez down to the middle of the seventeenth century. It
appears to have frequented Syria and even Asia Minor at earlier periods, but
is now found only in the seclusion of remoter deserts.
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[82] 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. 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
urogallus, the finest of the grouse family, formerly abundant in Scotland,
had become extinct in Great Britain, but has been reintroduced from
Sweden.[81] The ostrich is mentioned by all the old travellers, as common
on the Isthmus of Suez down to the middle of the seventeenth century. It
appears to have frequented Syria and even Asia Minor at earlier periods, but
is now found only in the seclusion of remoter deserts.
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[82] 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. 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
Page 77
creeping things, with which the prolific powers of insect life would
otherwise cover the earth.
Introduction of Birds.
Man has undesignedly introduced into new districts perhaps fewer
species of birds than of quadrupeds; 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.
[83]
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 of course have claimed the
rights of citizenship in the country where they first took to the wing.[84]
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 even of the tzetze fly, as
Toussenel and Michelet have framed in behalf of the bird.[85] The silkworm
and the bee need no apologist; a gallnut produced by the puncture of an
insect 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. But agriculture,
too, is indebted to the insect and the worm. 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 the pollen of the wild fruit—and this
process, called caprification, is not yet entirely obsolete. The earthworms
long ago made good their title to the respect and gratitude of the farmer as
otherwise cover the earth.
Introduction of Birds.
Man has undesignedly introduced into new districts perhaps fewer
species of birds than of quadrupeds; 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.
[83]
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 of course have claimed the
rights of citizenship in the country where they first took to the wing.[84]
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 even of the tzetze fly, as
Toussenel and Michelet have framed in behalf of the bird.[85] The silkworm
and the bee need no apologist; a gallnut produced by the puncture of an
insect 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. But agriculture,
too, is indebted to the insect and the worm. 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 the pollen of the wild fruit—and this
process, called caprification, is not yet entirely obsolete. The earthworms
long ago made good their title to the respect and gratitude of the farmer as
Page 78
well as of the angler. The utility of the earthworms has been pointed out in
many scientific as well as in many agricultural treatises. The following
extract, cut from a newspaper, will answer my present purpose:
"Mr. Josiah Parkes, the consulting engineer of the Royal Agricultural
Society of England, says that worms are great assistants to the drainer, and
valuable aids to the farmer in keeping up the fertility of the soil. He says
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 with Mr. Thomas Hammond, of Penhurst, Kent,
part of a field which he had deeply drained, after long-previous shallow
drainage, he 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. Mr. Henry Handley had
informed him of a piece of land near the sea in Lincolnshire, over which the
sea had broken and killed all the worms—the field remained sterile until the
worms again inhabited it. He also showed him a piece of pasture land near
to his house, in which worms were in such numbers that he thought their
casts interfered too much with its produce, which induced him to have it
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, has been admirably traced by
Mr. C. Darwin, of Down, Kent, who has shown that in a few years they
have actually elevated the surface of fields by a large 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 others who have discussed
the subject, have 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. The manure 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
many scientific as well as in many agricultural treatises. The following
extract, cut from a newspaper, will answer my present purpose:
"Mr. Josiah Parkes, the consulting engineer of the Royal Agricultural
Society of England, says that worms are great assistants to the drainer, and
valuable aids to the farmer in keeping up the fertility of the soil. He says
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 with Mr. Thomas Hammond, of Penhurst, Kent,
part of a field which he had deeply drained, after long-previous shallow
drainage, he 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. Mr. Henry Handley had
informed him of a piece of land near the sea in Lincolnshire, over which the
sea had broken and killed all the worms—the field remained sterile until the
worms again inhabited it. He also showed him a piece of pasture land near
to his house, in which worms were in such numbers that he thought their
casts interfered too much with its produce, which induced him to have it
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, has been admirably traced by
Mr. C. Darwin, of Down, Kent, who has shown that in a few years they
have actually elevated the surface of fields by a large 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 others who have discussed
the subject, have 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. The manure 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
Page 79
soils, we may easily see that they furnish no insignificant contribution to the
nutritive material required for the growth of plants.[86]
The perforations of the earthworm 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 surface. But 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.[87] I am acquainted with no single fact so strikingly illustrative
of this importance, as the following statement which I take from a notice of
Darwin's volume, On Various Contrivances by which British and Foreign
Orchids are Fertilized by Insects, in the Saturday Review, of October 18,
1862: "The net result is, that some six thousand species of orchids are
absolutely dependent upon the agency of insects for their fertilization. That
is to say, 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. 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 checking 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, 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
beneficial to another. 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 harmonies of
nature when we throw the smallest pebble into the ocean of organic life.
This much, however, we seem authorized 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,
nutritive material required for the growth of plants.[86]
The perforations of the earthworm 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 surface. But 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.[87] I am acquainted with no single fact so strikingly illustrative
of this importance, as the following statement which I take from a notice of
Darwin's volume, On Various Contrivances by which British and Foreign
Orchids are Fertilized by Insects, in the Saturday Review, of October 18,
1862: "The net result is, that some six thousand species of orchids are
absolutely dependent upon the agency of insects for their fertilization. That
is to say, 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. 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 checking 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, 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
beneficial to another. 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 harmonies of
nature when we throw the smallest pebble into the ocean of organic life.
This much, however, we seem authorized 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,
Page 80
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 Cochituate 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 animalculæ which could not be shut out,
nor live in the water without the vegetable element.[88]
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
introduces new species, 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
mere 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 destructor, 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,
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 Cochituate 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 animalculæ which could not be shut out,
nor live in the water without the vegetable element.[88]
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
introduces new species, 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
mere 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 destructor, 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,
Page 81
and a noxious European aphis has first attacked the American wheatfields
within the last four or five 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 much 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
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."
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. 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.[89] This useful
creature was carried to the United States by European colonists, in the latter
part of the seventeenth century; it did not cross the Mississippi till the close
of the eighteenth, and it is only within the last five or six years that it has
been transported to California, where it was previously unknown. The
Italian stingless bee has very lately been introduced into the United States.
within the last four or five 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 much 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
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."
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. 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.[89] This useful
creature was carried to the United States by European colonists, in the latter
part of the seventeenth century; it did not cross the Mississippi till the close
of the eighteenth, and it is only within the last five or six years that it has
been transported to California, where it was previously unknown. The
Italian stingless bee has very lately been introduced into the United States.
Page 82
The insects and worms intentionally transplanted by man bear but a
small proportion 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.[90]
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,[91] 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.[92] 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 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.
The carnivorous, and often the herbivorous insects render an 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
small proportion 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.[90]
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,[91] 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.[92] 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 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.
The carnivorous, and often the herbivorous insects render an 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
Page 83
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
much larger quantity of putrescent organic material than the quadrupeds and
the birds which feed upon such aliment.
Destruction of Insects.
It is well known to naturalists, but less familiarly to common observers,
that the aquatic larvæ of some insects constitute, at certain seasons, a large
part of the food of fresh-water fish, while other larvæ, in their turn, prey
upon the spawn and even the young of their persecutors.[93] The larvæ of
the mosquito and the gnat are the favorite food of the trout in the wooded
regions where those insects abound.[94] Earlier in the year the trout feeds on
the larvæ 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
the tree to prepare a lodgment for a future colony of boring larvæ, but to
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
much larger quantity of putrescent organic material than the quadrupeds and
the birds which feed upon such aliment.
Destruction of Insects.
It is well known to naturalists, but less familiarly to common observers,
that the aquatic larvæ of some insects constitute, at certain seasons, a large
part of the food of fresh-water fish, while other larvæ, in their turn, prey
upon the spawn and even the young of their persecutors.[93] The larvæ of
the mosquito and the gnat are the favorite food of the trout in the wooded
regions where those insects abound.[94] Earlier in the year the trout feeds on
the larvæ 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
the tree to prepare a lodgment for a future colony of boring larvæ, but to
Page 84
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 larvæ. 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—of which I believe only a single
specimen, secured by Mr. Sandwith, has yet reached Europe—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.
Reptiles.
But perhaps 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
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 larvæ. 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—of which I believe only a single
specimen, secured by Mr. Sandwith, has yet reached Europe—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.
Reptiles.
But perhaps 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
Page 85
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 much upon insects, as well as upon
mice, moles, and small reptiles, including also other snakes. 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. 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.[95] 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.[96]
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 affected 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 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.[97] It was, however, very actively prosecuted in the Middle
Ages, and the Biscayans seem to have been particularly successful in this as
walls and trees, and consume as egg, worm, and chrysalis, in their earlier
metamorphoses. The serpents feed much upon insects, as well as upon
mice, moles, and small reptiles, including also other snakes. 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. 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.[95] 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.[96]
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 affected 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 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.[97] It was, however, very actively prosecuted in the Middle
Ages, and the Biscayans seem to have been particularly successful in this as
Page 86
indeed in other branches of nautical industry.[98] 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, we 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 the soft
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. A very few years since, the United States had more than six
hundred whaling ships constantly 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.[99] 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 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 sufficient, possibly, to suggest an explanation of
some phenomena at present unaccounted for.
For instance, as I have observed in another work,[100] the
phosphorescence of the sea was unknown to ancient writers, or at least
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, we 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 the soft
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. A very few years since, the United States had more than six
hundred whaling ships constantly 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.[99] 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 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 sufficient, possibly, to suggest an explanation of
some phenomena at present unaccounted for.
For instance, as I have observed in another work,[100] the
phosphorescence of the sea was unknown to ancient writers, or at least
Page 87
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 animalculæ 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. The enormous destruction of 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. 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.[101] 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, though not objects of systematic pursuit, are
now comparatively rare in many waters where they formerly abounded. The
result is, that man has greatly reduced the numbers 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
exercised 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.
Introduction and Breeding of Fish.
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 animalculæ 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. The enormous destruction of 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. 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.[101] 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, though not objects of systematic pursuit, are
now comparatively rare in many waters where they formerly abounded. The
result is, that man has greatly reduced the numbers 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
exercised 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.
Introduction and Breeding of Fish.
Page 88
The introduction and successful breeding of fish of foreign species
appears to have been long practised in China and was not unknown to the
Greeks and Romans. 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 plants, man has sometimes undesignedly
introduced new 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. 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.
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. Sea fish, the smelt among others, are said to have been naturalized
in fresh water, and some 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
appears to have been long practised in China and was not unknown to the
Greeks and Romans. 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 plants, man has sometimes undesignedly
introduced new 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. 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.
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. Sea fish, the smelt among others, are said to have been naturalized
in fresh water, and some 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
Page 89
lake—once, as is assumed, a maritime bay—into fresh.[102] 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,[103] and remains of the seal have been
found at other times in the same waters.
The remains of the higher orders of aquatic animals 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 from oysters, 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. 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.
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,[103] and remains of the seal have been
found at other times in the same waters.
The remains of the higher orders of aquatic animals 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 from oysters, 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. 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.
Page 90
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 has already produced very valuable
results, and is apparently destined to occupy an extremely conspicuous
place in the history of man's efforts to compensate his prodigal waste of the
gifts of nature. The restoration of the primitive abundance of salt and fresh
water fish, is one of the greatest material benefits 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
expenditure of capital and labor in agricultural operations. 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.
Extirpation 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.
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 has already produced very valuable
results, and is apparently destined to occupy an extremely conspicuous
place in the history of man's efforts to compensate his prodigal waste of the
gifts of nature. The restoration of the primitive abundance of salt and fresh
water fish, is one of the greatest material benefits 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
expenditure of capital and labor in agricultural operations. 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.
Extirpation 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.
Page 91
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 in the Northern
and Southern Pacific, the walrus 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 tamed 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.[104] 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 Northern 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.[105] 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, that the fervent Catholic of the shores of the
Mediterranean may have wherewithal to satisfy the cravings of the stomach
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 in the Northern
and Southern Pacific, the walrus 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 tamed 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.[104] 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 Northern 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.[105] 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, that the fervent Catholic of the shores of the
Mediterranean may have wherewithal to satisfy the cravings of the stomach
Page 92
during next year's Lent, without imperilling his soul by violating the
discipline of the papal church; 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.[106]
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 ponds 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 to the 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.
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 the disappearance 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
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
discipline of the papal church; 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.[106]
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 ponds 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 to the 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.
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 the disappearance 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
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
Page 93
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.[107]
Industrial operations are not less destructive to fish which live or spawn in
fresh water. Milldams 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.
Minute Organisms.
Besides the larger creatures 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 functions in
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 exuviæ 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 animalculæ so small as to
become visible only by the aid of lenses magnifying a hundred times the
linear measures. It is popularly supposed that animalculæ, or what are
commonly embraced under the vague name of infusoria, inhabit the water
alone, but 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;[108] and a microscopic examination of a
handful of earth connected with the material evidences of guilt has enabled
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.[107]
Industrial operations are not less destructive to fish which live or spawn in
fresh water. Milldams 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.
Minute Organisms.
Besides the larger creatures 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 functions in
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 exuviæ 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 animalculæ so small as to
become visible only by the aid of lenses magnifying a hundred times the
linear measures. It is popularly supposed that animalculæ, or what are
commonly embraced under the vague name of infusoria, inhabit the water
alone, but 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;[108] and a microscopic examination of a
handful of earth connected with the material evidences of guilt has enabled
Page 94
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 much of these fragile structures
to a state of comminution which even the 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.[109]
It is evident that the chemical, and in many cases the 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 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 easy matter, may promote the
construction of a barrier to coast navigation at one point, and check the
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 much of these fragile structures
to a state of comminution which even the 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.[109]
It is evident that the chemical, and in many cases the 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 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 easy matter, may promote the
construction of a barrier to coast navigation at one point, and check the
Page 95
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.[110] It does not seem impossible that this coral
might be 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 diatomaceæ 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 diatomaceæ 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 the
economy of nature, 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
direct the operations, not of unembodied physical forces, but of beings, in
popular apprehension, almost as immaterial as they.
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
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.[110] It does not seem impossible that this coral
might be 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 diatomaceæ 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 diatomaceæ 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 the
economy of nature, 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
direct the operations, not of unembodied physical forces, but of beings, in
popular apprehension, almost as immaterial as they.
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
Page 96
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 redwood 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. 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.[111]
which one of the hairs of his head is a larger cylinder than is the trunk of the
giant California redwood 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. 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.[111]
Page 97
CHAPTER III.
THE WOODS.
THE HABITABLE EARTH ORIGINALLY WOODED—THE FOREST DOES NOT FURNISH
FOOD FOR MAN—FIRST REMOVAL OF THE WOODS—EFFECTS OF FIRE ON FOREST
SOIL—EFFECTS OF THE DESTRUCTION OF THE FOREST—ELECTRICAL INFLUENCE OF
TREES—CHEMICAL INFLUENCE OF THE FOREST.
INFLUENCE OF THE FOREST, CONSIDERED AS INORGANIC MATTER, ON
TEMPERATURE: a, ABSORBING AND EMITTING SURFACE; b, TREES AS CONDUCTORS
OF HEAT; c, TREES IN SUMMER AND IN WINTER; d, DEAD PRODUCTS OF TREES; e,
TREES AS A SHELTER TO GROUNDS TO THE LEEWARD OF THEM; f, TREES AS A
PROTECTION AGAINST MALARIA—THE FOREST, AS INORGANIC MATTER, TENDS TO
MITIGATE EXTREMES.
TREES AS ORGANISMS: SPECIFIC TEMPERATURE—TOTAL INFLUENCE OF THE FOREST
ON TEMPERATURE.
INFLUENCE OF FORESTS ON THE HUMIDITY OF THE AIR AND THE EARTH: a, AS
INORGANIC MATTER; b, AS ORGANIC—WOOD MOSSES AND FUNGI—FLOW OF SAP—
ABSORPTION AND EXHALATION OF MOISTURE BY TREES—BALANCE OF
CONFLICTING INFLUENCES—INFLUENCE OF THE FOREST ON TEMPERATURE AND
PRECIPITATION—INFLUENCE OF THE FOREST ON THE HUMIDITY OF THE SOIL—ITS
INFLUENCE ON THE FLOW OF SPRINGS—GENERAL CONSEQUENCES OF THE
DESTRUCTION OF THE WOODS—LITERATURE AND CONDITION OF THE FOREST IN
DIFFERENT COUNTRIES—THE INFLUENCE OF THE FOREST ON INUNDATIONS—
DESTRUCTIVE ACTION OF TORRENTS—THE PO AND ITS DEPOSITS—MOUNTAIN
SLIDES—PROTECTION AGAINST THE FALL OF ROCKS AND AVALANCHES BY TREES—
PRINCIPAL CAUSES OF THE DESTRUCTION OF THE FOREST—AMERICAN FOREST
TREES—SPECIAL CAUSES OF THE DESTRUCTION OF EUROPEAN WOODS—ROYAL
FORESTS AND GAME LAWS—SMALL FOREST PLANTS, VITALITY OF SEEDS—UTILITY
OF THE FOREST—THE FORESTS OF EUROPE—FORESTS OF THE UNITED STATES AND
CANADA—THE ECONOMY OF THE FOREST—EUROPEAN AND AMERICAN TREES
COMPARED—SYLVICULTURE—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
THE WOODS.
THE HABITABLE EARTH ORIGINALLY WOODED—THE FOREST DOES NOT FURNISH
FOOD FOR MAN—FIRST REMOVAL OF THE WOODS—EFFECTS OF FIRE ON FOREST
SOIL—EFFECTS OF THE DESTRUCTION OF THE FOREST—ELECTRICAL INFLUENCE OF
TREES—CHEMICAL INFLUENCE OF THE FOREST.
INFLUENCE OF THE FOREST, CONSIDERED AS INORGANIC MATTER, ON
TEMPERATURE: a, ABSORBING AND EMITTING SURFACE; b, TREES AS CONDUCTORS
OF HEAT; c, TREES IN SUMMER AND IN WINTER; d, DEAD PRODUCTS OF TREES; e,
TREES AS A SHELTER TO GROUNDS TO THE LEEWARD OF THEM; f, TREES AS A
PROTECTION AGAINST MALARIA—THE FOREST, AS INORGANIC MATTER, TENDS TO
MITIGATE EXTREMES.
TREES AS ORGANISMS: SPECIFIC TEMPERATURE—TOTAL INFLUENCE OF THE FOREST
ON TEMPERATURE.
INFLUENCE OF FORESTS ON THE HUMIDITY OF THE AIR AND THE EARTH: a, AS
INORGANIC MATTER; b, AS ORGANIC—WOOD MOSSES AND FUNGI—FLOW OF SAP—
ABSORPTION AND EXHALATION OF MOISTURE BY TREES—BALANCE OF
CONFLICTING INFLUENCES—INFLUENCE OF THE FOREST ON TEMPERATURE AND
PRECIPITATION—INFLUENCE OF THE FOREST ON THE HUMIDITY OF THE SOIL—ITS
INFLUENCE ON THE FLOW OF SPRINGS—GENERAL CONSEQUENCES OF THE
DESTRUCTION OF THE WOODS—LITERATURE AND CONDITION OF THE FOREST IN
DIFFERENT COUNTRIES—THE INFLUENCE OF THE FOREST ON INUNDATIONS—
DESTRUCTIVE ACTION OF TORRENTS—THE PO AND ITS DEPOSITS—MOUNTAIN
SLIDES—PROTECTION AGAINST THE FALL OF ROCKS AND AVALANCHES BY TREES—
PRINCIPAL CAUSES OF THE DESTRUCTION OF THE FOREST—AMERICAN FOREST
TREES—SPECIAL CAUSES OF THE DESTRUCTION OF EUROPEAN WOODS—ROYAL
FORESTS AND GAME LAWS—SMALL FOREST PLANTS, VITALITY OF SEEDS—UTILITY
OF THE FOREST—THE FORESTS OF EUROPE—FORESTS OF THE UNITED STATES AND
CANADA—THE ECONOMY OF THE FOREST—EUROPEAN AND AMERICAN TREES
COMPARED—SYLVICULTURE—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
Page 98
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;[112] and from the state of
much of North and of South America when they were discovered and
colonized by the European race.[113]
These evidences are strengthened by observation of the natural
economy of our own time; for, whenever a tract of country, once inhabited
and cultivated by man, is abandoned by him and by domestic animals,[114]
and surrendered to the undisturbed influences of spontaneous nature, its soil
sooner or 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
derived from the decomposition of their own foliage, or sending out long
rootlets into the surrounding earth in search of juices to feed them.
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
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;[112] and from the state of
much of North and of South America when they were discovered and
colonized by the European race.[113]
These evidences are strengthened by observation of the natural
economy of our own time; for, whenever a tract of country, once inhabited
and cultivated by man, is abandoned by him and by domestic animals,[114]
and surrendered to the undisturbed influences of spontaneous nature, its soil
sooner or 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
derived from the decomposition of their own foliage, or sending out long
rootlets into the surrounding earth in search of juices to feed them.
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
Page 99
wholly devoid of vegetation.[115] But the cactus is making inroads even
here, while the volcanic sand and molten rock thrown out by Vesuvius soon
becomes productive. George Sandys, who visited this latter mountain 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."[116]
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 seedpods 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
watercourses 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.
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
here, while the volcanic sand and molten rock thrown out by Vesuvius soon
becomes productive. George Sandys, who visited this latter mountain 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."[116]
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 seedpods 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
watercourses 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.
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
Page 100
only are found the seeds and insects, which form the sustenance of the non-
carnivorous birds and quadrupeds.[117]
First Removal of the Forest.
As soon as 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,[118] 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
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 the 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.[119] This rude economy would be continued for
carnivorous birds and quadrupeds.[117]
First Removal of the Forest.
As soon as 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,[118] 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
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 the 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.[119] This rude economy would be continued for
Page 101
generations, and wasteful as it is, is still largely pursued in Northern
Sweden, Swedish Lapland, and sometimes even in France and the United
States.[120]
Effects of Fire on Forest Soil.
Aside from the mechanical and chemical effects of the disturbance of
the soil by agricultural operations, and of 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 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.[121]
Effects of Destruction of the Forest.
The physico-geographical effects of the destruction of the 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 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, configuration, consistence, and clothing of
surface.
Sweden, Swedish Lapland, and sometimes even in France and the United
States.[120]
Effects of Fire on Forest Soil.
Aside from the mechanical and chemical effects of the disturbance of
the soil by agricultural operations, and of 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 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.[121]
Effects of Destruction of the Forest.
The physico-geographical effects of the destruction of the 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 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, configuration, consistence, and clothing of
surface.
Page 102
For reasons assigned in the first chapter, 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 certain general results are almost universally accepted,
and seem indeed too well supported to admit of serious question.
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 some change of electrical condition.
Hypothetical cases may be put in which the character of the change could
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 certain, 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 better 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, are 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
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 certain general results are almost universally accepted,
and seem indeed too well supported to admit of serious question.
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 some change of electrical condition.
Hypothetical cases may be put in which the character of the change could
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 certain, 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 better 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, are 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
Page 103
since the general prostration of the forest, these tempests are laying waste
even the mountain soils whose older inhabitants scarcely knew this plague.
[122]
The paragrandini,[123] 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 image of the vast paragrandini,
pines, larches, firs, which nature had planted by millions on the crests and
ridges of the Alps and the Apennines."[124] "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."[125] 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,[126] and it appears upon good authority, that a similar
increase in the frequency and violence of hail storms in the neighborhood of
Saluzzo and Mondovì, the lower part of the Valtelline, and the territory of
Verona and Vicenza, is probably to be ascribed to a similar cause.[127]
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.[128] 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 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
even the mountain soils whose older inhabitants scarcely knew this plague.
[122]
The paragrandini,[123] 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 image of the vast paragrandini,
pines, larches, firs, which nature had planted by millions on the crests and
ridges of the Alps and the Apennines."[124] "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."[125] 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,[126] and it appears upon good authority, that a similar
increase in the frequency and violence of hail storms in the neighborhood of
Saluzzo and Mondovì, the lower part of the Valtelline, and the territory of
Verona and Vicenza, is probably to be ascribed to a similar cause.[127]
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.[128] 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 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
Page 104
that the mineral ingredients of land springs 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.[129] Our inquiries upon this branch of the subject
will accordingly be limited to the thermometrical and hygrometrical
influences of the woods.
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,
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. But the forest, regarded purely
as inorganic matter, and without reference to its living processes of
absorption and exhalation of water and gases, 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.
a. 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.[130] An acre of chalk, rolled hard and smooth, would
have great reflecting power, but its radiation would be much increased by
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.[129] Our inquiries upon this branch of the subject
will accordingly be limited to the thermometrical and hygrometrical
influences of the woods.
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,
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. But the forest, regarded purely
as inorganic matter, and without reference to its living processes of
absorption and exhalation of water and gases, 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.
a. 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.[130] An acre of chalk, rolled hard and smooth, would
have great reflecting power, but its radiation would be much increased by
Page 105
breaking it up into clods, because the actually exposed surface would be
greater, though the outline of the field remained the same. The area of a
triangle being equal to its base multiplied by half the length of a
perpendicular let fall from its apex, it follows that the entire superficies of
the triangular faces of a quadrangular pyramid, the perpendicular of whose
sides should be twice the length of the base, would be four times the area of
the ground it covered, and would add to the field on which it stood so much
surface capable of receiving and emitting heat, though, in consequence of
obliquity and direction of plane, its actual absorption and emission of heat
might not be so great as that of an additional quantity of level ground
containing four times the area of its base. The lesser inequalities 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,
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.[131] On the other hand, the growing leaves of trees generally form a
succession of stages, or, loosely speaking, layers, corresponding to the
animal 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 heat 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.[132]
greater, though the outline of the field remained the same. The area of a
triangle being equal to its base multiplied by half the length of a
perpendicular let fall from its apex, it follows that the entire superficies of
the triangular faces of a quadrangular pyramid, the perpendicular of whose
sides should be twice the length of the base, would be four times the area of
the ground it covered, and would add to the field on which it stood so much
surface capable of receiving and emitting heat, though, in consequence of
obliquity and direction of plane, its actual absorption and emission of heat
might not be so great as that of an additional quantity of level ground
containing four times the area of its base. The lesser inequalities 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,
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.[131] On the other hand, the growing leaves of trees generally form a
succession of stages, or, loosely speaking, layers, corresponding to the
animal 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 heat 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.[132]
Page 106
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 spiculæ, 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
exhalation of the fluids of the plant in a gaseous form; 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 yards
above has not been brought down to the dew point, still less to 32°, the
degree of cold required to congeal dew to frost.[133]
b. Trees as Conductors of Heat.
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.
c. Trees in Summer and Winter.
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 spiculæ, 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
exhalation of the fluids of the plant in a gaseous form; 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 yards
above has not been brought down to the dew point, still less to 32°, the
degree of cold required to congeal dew to frost.[133]
b. Trees as Conductors of Heat.
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.
c. Trees in Summer and Winter.
Page 107
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.
d. 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 you examine the constitution of the
superficial soil in a primitive or an old and undisturbed artificially planted
wood, you find, first, a deposit of undecayed leaves, twigs, and seeds, lying
in loose layers on the surface; then, more compact beds of the same
materials in incipient, and, as you 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.
Leaves, still entire, or partially decayed, are very indifferent conductors of
heat, 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.
e. Trees as a Shelter to Ground to the Leeward.
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.
d. 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 you examine the constitution of the
superficial soil in a primitive or an old and undisturbed artificially planted
wood, you find, first, a deposit of undecayed leaves, twigs, and seeds, lying
in loose layers on the surface; then, more compact beds of the same
materials in incipient, and, as you 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.
Leaves, still entire, or partially decayed, are very indifferent conductors of
heat, 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.
e. Trees as a Shelter to Ground to the Leeward.
Page 108
The action of the forest, considered merely as a mechanical shelter to
grounds lying to the leeward of it, would seem to be an influence of too
restricted a character to deserve much notice; but many facts concur to
show that it is an important element in local climate, and that it is often a
valuable means of defence against the spread of miasmatic effluvia, though,
in this last case, it may exercise a chemical as well as a mechanical agency.
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 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."[134]
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 farther 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."[135]
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
grounds lying to the leeward of it, would seem to be an influence of too
restricted a character to deserve much notice; but many facts concur to
show that it is an important element in local climate, and that it is often a
valuable means of defence against the spread of miasmatic effluvia, though,
in this last case, it may exercise a chemical as well as a mechanical agency.
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 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."[134]
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 farther 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."[135]
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
Page 109
ineffectual; and in many neighboring communes the grapes and the grain
are swept off by the blasts of the south and southwest winds."
On the other hand, according to the same authority, the pinery of Porto,
near Ravenna—which is 33 kilometres 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.[136]
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.[137]
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
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 mètres from each other, as a shelter
which experience had proved to be useful in France.[138] "In the valley of
the Rhone," says Becquerel, "a simple hedge, two mètres in height, is a
sufficient protection for a distance of twenty-two mètres."[139] The
are swept off by the blasts of the south and southwest winds."
On the other hand, according to the same authority, the pinery of Porto,
near Ravenna—which is 33 kilometres 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.[136]
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.[137]
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
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 mètres from each other, as a shelter
which experience had proved to be useful in France.[138] "In the valley of
the Rhone," says Becquerel, "a simple hedge, two mètres in height, is a
sufficient protection for a distance of twenty-two mètres."[139] The
Page 110
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. If we suppose the trees of a wood to have a mean height of
only twenty yards, they would often beneficially affect the temperature or
the moisture of a belt of land two or three hundred yards in width, and thus
perhaps rescue valuable crops from destruction.[140]
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.[141]
"It is proved," says Clavé, "Études," p. 44, "that the department of
Ardèche, 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."
Dussard, as quoted by Ribbe,[142] maintains that even the mistral, or
northwest 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 Cévennes 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
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. If we suppose the trees of a wood to have a mean height of
only twenty yards, they would often beneficially affect the temperature or
the moisture of a belt of land two or three hundred yards in width, and thus
perhaps rescue valuable crops from destruction.[140]
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.[141]
"It is proved," says Clavé, "Études," p. 44, "that the department of
Ardèche, 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."
Dussard, as quoted by Ribbe,[142] maintains that even the mistral, or
northwest 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 Cévennes 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
Page 111
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 northwest 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 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 Ilyères, 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 well no longer, and that it is difficult to raise young trees.[143]
f. Trees as a Protection against Malaria.
The influence of forests in preventing the diffusion of miasmatic vapors
is a matter of less familiar observation, and perhaps 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 again
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."[144] 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
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 northwest 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 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 Ilyères, 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 well no longer, and that it is difficult to raise young trees.[143]
f. Trees as a Protection against Malaria.
The influence of forests in preventing the diffusion of miasmatic vapors
is a matter of less familiar observation, and perhaps 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 again
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."[144] 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
Page 112
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 alba, in such directions as to obstruct the currents
of air from malarious localities, and thus intercept a great proportion of the
pernicious exhalations."[145] Lieutenant Maury even believed that a few
rows of sunflowers, planted between the Washington Observatory and the
marshy banks of the Potomac, had saved the inmates 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.[146] 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.
[147]
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.[148]
The Forest, as Inorganic Matter, tends to mitigate
Extremes.
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 alba, in such directions as to obstruct the currents
of air from malarious localities, and thus intercept a great proportion of the
pernicious exhalations."[145] Lieutenant Maury even believed that a few
rows of sunflowers, planted between the Washington Observatory and the
marshy banks of the Potomac, had saved the inmates 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.[146] 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.
[147]
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.[148]
The Forest, as Inorganic Matter, tends to mitigate
Extremes.
Page 113
The surface which trees and leaves present augments the general
superficies of the earth exposed to the absorption of heat, and increases the
radiating and reflecting area in the same proportion. It is impossible to
measure the relative value of these two elements—increase of absorbing
and increase of emitting surface—as thermometrical influences, because
they exert themselves under infinitely varied conditions; and it is equally
impossible to make a quantitative estimate of any partial, still more of the
total effect of the forest, considered as dead matter, on the temperature of
the atmosphere, and of the portion of the earth's surface acted on by it. But
it seems probable that its greatest influence in this respect is due to its
character of a screen, or mechanical obstacle to the transmission of heat
between the earth and the air; and this is equally true of the standing tree
and of the dead foliage which it deposits in successive layers at its foot.
The complicated action of trees and their products, as dead absorbents,
radiators, reflectors, and conductors of heat, and as interceptors of its
transmission, is so intimately connected with their effects upon the
humidity of the air and the earth, and with all their living processes, that it
is difficult to separate the former from the latter class of influences; but
upon the whole, the forest must thus far be regarded as tending to mitigate
extremes, and, therefore, as an equalizer of temperature.
TREES AS ORGANISMS.
Specific Heat.
Trees, considered as organisms, produce in themselves, or in the air, a
certain amount of heat, by absorbing and condensing atmospheric vapor,
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 certain amount of weight is to be ascribed to this element, in
estimating the action of the forest upon atmospheric temperature.
superficies of the earth exposed to the absorption of heat, and increases the
radiating and reflecting area in the same proportion. It is impossible to
measure the relative value of these two elements—increase of absorbing
and increase of emitting surface—as thermometrical influences, because
they exert themselves under infinitely varied conditions; and it is equally
impossible to make a quantitative estimate of any partial, still more of the
total effect of the forest, considered as dead matter, on the temperature of
the atmosphere, and of the portion of the earth's surface acted on by it. But
it seems probable that its greatest influence in this respect is due to its
character of a screen, or mechanical obstacle to the transmission of heat
between the earth and the air; and this is equally true of the standing tree
and of the dead foliage which it deposits in successive layers at its foot.
The complicated action of trees and their products, as dead absorbents,
radiators, reflectors, and conductors of heat, and as interceptors of its
transmission, is so intimately connected with their effects upon the
humidity of the air and the earth, and with all their living processes, that it
is difficult to separate the former from the latter class of influences; but
upon the whole, the forest must thus far be regarded as tending to mitigate
extremes, and, therefore, as an equalizer of temperature.
TREES AS ORGANISMS.
Specific Heat.
Trees, considered as organisms, produce in themselves, or in the air, a
certain amount of heat, by absorbing and condensing atmospheric vapor,
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 certain amount of weight is to be ascribed to this element, in
estimating the action of the forest upon atmospheric temperature.
Page 114
"Observation shows," says Meguscher, "that the wood of a living tree
maintains a temperature of +12° or 13° Cent. [= 54°, 56° Fahr.] when the
temperature of the air stands at 3°, 7°, and 8° [=37°, 46°, 47° 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° [= 67° Fahr.],
that of the tree is always the highest; but if the temperature of the air rises to
18°, that of the vegetable growth is the lowest. Since, then, trees maintain at
all seasons a constant mean temperature of 12° [= 54° 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."[149]
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° or 50° Cent. [= 104° or 122° Fahr.]. It is
very probable that this phenomenon is general, and varies only in the
intensity with which it is manifested."[150]
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.
In a paper on Meteorology by Professor Henry, published in the United
States Patent Office Report for 1857, p. 504, that distinguished physicist
observes: "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."
There can be no doubt that moisture is given out by trees and
evaporated in extremely cold winter-weather, and unless new fluid were
maintains a temperature of +12° or 13° Cent. [= 54°, 56° Fahr.] when the
temperature of the air stands at 3°, 7°, and 8° [=37°, 46°, 47° 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° [= 67° Fahr.],
that of the tree is always the highest; but if the temperature of the air rises to
18°, that of the vegetable growth is the lowest. Since, then, trees maintain at
all seasons a constant mean temperature of 12° [= 54° 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."[149]
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° or 50° Cent. [= 104° or 122° Fahr.]. It is
very probable that this phenomenon is general, and varies only in the
intensity with which it is manifested."[150]
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.
In a paper on Meteorology by Professor Henry, published in the United
States Patent Office Report for 1857, p. 504, that distinguished physicist
observes: "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."
There can be no doubt that moisture is given out by trees and
evaporated in extremely cold winter-weather, and unless new fluid were
Page 115
supplied from the roots, 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."[151] 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."[152] 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
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 at that season. But, however this may be,
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.[153]
Total Influence of the Forest on Temperature.
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."[151] 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."[152] 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
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 at that season. But, however this may be,
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.[153]
Total Influence of the Forest on Temperature.
Page 116
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 149, Gay-Lussac says: "In my
opinion we 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 à 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
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 149, Gay-Lussac says: "In my
opinion we 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 à 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
Page 117
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° Fahr.]. In that case, the ascending currents of warm air would cease, 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."[154]
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 the forests 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.[155]
INFLUENCE OF FORESTS ON THE HUMIDITY
OF THE AIR AND THE EARTH.
a. As Inorganic Matter.
The most important influence of the forest on climate is, no doubt, that
which it exercises on the humidity of the air and the earth, and this climatic
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° Fahr.]. In that case, the ascending currents of warm air would cease, 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."[154]
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 the forests 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.[155]
INFLUENCE OF FORESTS ON THE HUMIDITY
OF THE AIR AND THE EARTH.
a. As Inorganic Matter.
The most important influence of the forest on climate is, no doubt, that
which it exercises on the humidity of the air and the earth, and this climatic
Page 118
action it exerts partly as dead, partly as living matter. By its interposition as
a curtain between the sky and the ground, it intercepts a large proportion of
the dew and the lighter showers, which would otherwise moisten the
surface of the soil, and restores it to the atmosphere by evaporation; while
in heavier rains, the large drops which fall upon the leaves and branches are
broken into smaller ones, and consequently strike the ground with less
mechanical force, or are perhaps even dispersed into vapor without reaching
it.[156] As a screen, it prevents the access of the sun's rays to the earth, and,
of course, an elevation of temperature which would occasion a great
increase of evaporation. As a mechanical obstruction, it impedes 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.[157] 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.[158]
The vegetable mould, resulting from the decomposition of leaves and of
wood, carpets the ground with a spongy covering which obstructs the
evaporation from the mineral earth below, 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 the water along their
surface to the lower depths to which they reach, and thus serve to drain the
superior strata and remove the moisture out of the reach of evaporation.
b. The Forest as Organic.
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.
a curtain between the sky and the ground, it intercepts a large proportion of
the dew and the lighter showers, which would otherwise moisten the
surface of the soil, and restores it to the atmosphere by evaporation; while
in heavier rains, the large drops which fall upon the leaves and branches are
broken into smaller ones, and consequently strike the ground with less
mechanical force, or are perhaps even dispersed into vapor without reaching
it.[156] As a screen, it prevents the access of the sun's rays to the earth, and,
of course, an elevation of temperature which would occasion a great
increase of evaporation. As a mechanical obstruction, it impedes 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.[157] 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.[158]
The vegetable mould, resulting from the decomposition of leaves and of
wood, carpets the ground with a spongy covering which obstructs the
evaporation from the mineral earth below, 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 the water along their
surface to the lower depths to which they reach, and thus serve to drain the
superior strata and remove the moisture out of the reach of evaporation.
b. The Forest as Organic.
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.
Page 119
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. The outer
bark of most trees is of a corky character, not admitting the absorption of
much moisture from the atmosphere through its pores, and we can hardly
suppose that the buds are able to extract from the air a much larger supply.
The obvious conclusion as to the source from which the extraordinary
quantity of sap at this season is derived, is that to which scientific
investigation leads us, namely, that it is absorbed from the earth by the
roots, and thence distributed to all parts of the plant. Popular opinion,
indeed, supposes that all the vegetable fluids, during the entire period of
growth, are thus 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, not
only is the solid matter of the tree, in a certain proportion not important to
our present inquiry, received from the atmosphere in a gaseous form,
through the pores of the leaves and of the young shoots, but water in the
state of vapor is absorbed and contributed to the circulation, by the same
organs.[159] The amount of water taken up by the roots, however, is vastly
greater than that imbibed through the leaves, especially at the season when
the juices are most abundant, and when, as we have seen, the leaves are yet
in embryo. The quantity of water thus received from the air and the earth, in
a single year, by a wood of even 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.[160]
Wood Mosses and Fungi.
Besides the water drawn by the roots from the earth and the vapor
absorbed by the leaves from the air, the wood mosses and fungi, which
abound in all dense forests, take up a great quantity of moisture from the
atmosphere when it is charged with humidity, and exhale it again when the
air is dry. These humble organizations, which play a more important part in
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. The outer
bark of most trees is of a corky character, not admitting the absorption of
much moisture from the atmosphere through its pores, and we can hardly
suppose that the buds are able to extract from the air a much larger supply.
The obvious conclusion as to the source from which the extraordinary
quantity of sap at this season is derived, is that to which scientific
investigation leads us, namely, that it is absorbed from the earth by the
roots, and thence distributed to all parts of the plant. Popular opinion,
indeed, supposes that all the vegetable fluids, during the entire period of
growth, are thus 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, not
only is the solid matter of the tree, in a certain proportion not important to
our present inquiry, received from the atmosphere in a gaseous form,
through the pores of the leaves and of the young shoots, but water in the
state of vapor is absorbed and contributed to the circulation, by the same
organs.[159] The amount of water taken up by the roots, however, is vastly
greater than that imbibed through the leaves, especially at the season when
the juices are most abundant, and when, as we have seen, the leaves are yet
in embryo. The quantity of water thus received from the air and the earth, in
a single year, by a wood of even 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.[160]
Wood Mosses and Fungi.
Besides the water drawn by the roots from the earth and the vapor
absorbed by the leaves from the air, the wood mosses and fungi, which
abound in all dense forests, take up a great quantity of moisture from the
atmosphere when it is charged with humidity, and exhale it again when the
air is dry. These humble organizations, which play a more important part in
Page 120
regulating the humidity of the air than writers on the forest have usually
assigned to them, perish with the trees they grow on; but, in many
situations, nature provides a compensation for the tree mosses 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 mosses discharge a
portion of the functions appropriated to the wood, and while they render the
soil of improved lands much less fit for agricultural 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.[161]
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.[162] This, however, is but a trifling proportion of the water abstracted
from the earth by the roots during this season, when the yet undeveloped
leaves can hardly absorb an appreciable quantity of vapor from the
atmosphere;[163] 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.[164] The number of large maple trees on an
acre is frequently not less than fifty,[165] and of course the quantity of
moisture abstracted from the soil by this tree alone is measured by
assigned to them, perish with the trees they grow on; but, in many
situations, nature provides a compensation for the tree mosses 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 mosses discharge a
portion of the functions appropriated to the wood, and while they render the
soil of improved lands much less fit for agricultural 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.[161]
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.[162] This, however, is but a trifling proportion of the water abstracted
from the earth by the roots during this season, when the yet undeveloped
leaves can hardly absorb an appreciable quantity of vapor from the
atmosphere;[163] 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.[164] The number of large maple trees on an
acre is frequently not less than fifty,[165] and of course the quantity of
moisture abstracted from the soil by this tree alone is measured by
Page 121
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[166]—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 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.[167]
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
thirst of the roots is quenched, and the flow of sap from them to the stem is
greatly diminished.[168]
Absorption and Exhalation of Moisture.
The leaves now commence the process of absorption, and imbibe both
uncombined gases and an unascertained but perhaps considerable quantity
of watery 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 enters into new combinations, and
becomes a part of the solid framework of the vegetable, or a component of
its deciduous products, it is evident that the superfluous moisture must
somehow be carried off almost as rapidly as it flows into the tree.[169] 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 barb, and
vegetable physiology tells us that there is a current of sap toward the roots
as well as from them.[170] I do not know that the exudation of water into the
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[166]—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 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.[167]
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
thirst of the roots is quenched, and the flow of sap from them to the stem is
greatly diminished.[168]
Absorption and Exhalation of Moisture.
The leaves now commence the process of absorption, and imbibe both
uncombined gases and an unascertained but perhaps considerable quantity
of watery 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 enters into new combinations, and
becomes a part of the solid framework of the vegetable, or a component of
its deciduous products, it is evident that the superfluous moisture must
somehow be carried off almost as rapidly as it flows into the tree.[169] 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 barb, and
vegetable physiology tells us that there is a current of sap toward the roots
as well as from them.[170] I do not know that the exudation of water into the
Page 122
earth, through the bark or at the extremities of these latter organs, has been
directly 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 therefore difficult to believe that the
roots do not, to some extent, drain as well as flood the watercourses of their
stem. Later in the season the roots absorb less, and the now developed
leaves exhale a vastly 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 returned again 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.[171] 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 evaporation of the juices of the plant, by whatever process effected,
takes up atmospheric heat and produces refrigeration. This effect is not less
real, though much 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 or 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, 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, but 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.
directly 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 therefore difficult to believe that the
roots do not, to some extent, drain as well as flood the watercourses of their
stem. Later in the season the roots absorb less, and the now developed
leaves exhale a vastly 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 returned again 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.[171] 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 evaporation of the juices of the plant, by whatever process effected,
takes up atmospheric heat and produces refrigeration. This effect is not less
real, though much 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 or 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, 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, but 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.
Page 123
The hygroscopicity of vegetable mould is much greater than that of any
mineral earth, and therefore the soil of the forest absorbs more atmospheric
moisture than the open ground. The condensation of the vapor by
absorption disengages heat, and consequently raises the temperature of the
soil which absorbs it. Von Babo found the temperature of sandy earth thus
elevated from 20° to 27° centigrade, making a difference of nearly thirteen
degrees of Fahrenheit, and that of soil rich in humus from 20° to 31°
centigrade, a difference of almost twenty degrees of Fahrenheit.[172]
Balance of Conflicting Influences.
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 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
these 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
opposite directions, and, therefore, their influence is sometimes cumulative,
sometimes conflicting; but, upon the whole, their general effect seems to be
to mitigate extremes of atmospheric heat and cold, moisture and drought.
They serve as equalizers of temperature and humidity, and it is highly
mineral earth, and therefore the soil of the forest absorbs more atmospheric
moisture than the open ground. The condensation of the vapor by
absorption disengages heat, and consequently raises the temperature of the
soil which absorbs it. Von Babo found the temperature of sandy earth thus
elevated from 20° to 27° centigrade, making a difference of nearly thirteen
degrees of Fahrenheit, and that of soil rich in humus from 20° to 31°
centigrade, a difference of almost twenty degrees of Fahrenheit.[172]
Balance of Conflicting Influences.
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 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
these 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
opposite directions, and, therefore, their influence is sometimes cumulative,
sometimes conflicting; but, upon the whole, their general effect seems to be
to mitigate extremes of atmospheric heat and cold, moisture and drought.
They serve as equalizers of temperature and humidity, and it is highly
Page 124
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.
When, therefore, man destroyed these natural harmonizers of climatic
discords, he sacrificed 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 increased the range and lengthened the scale of
thermometric and hygrometric variation.
Influence of the Forest on Temperature and
Precipitation.
Aside from the question of compensation, it does not seem probable that
the forests sensibly affect the total quantity of precipitation, or the general
mean of atmospheric temperature of the globe, 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,[173] 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 the present geological epoch,
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 former 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 an
appreciable 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
they, at certain or uncertain periods, restore the equilibrium which, whether
as lifeless masses or as living organisms, they may have temporarily
disturbed.
When, therefore, man destroyed these natural harmonizers of climatic
discords, he sacrificed 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 increased the range and lengthened the scale of
thermometric and hygrometric variation.
Influence of the Forest on Temperature and
Precipitation.
Aside from the question of compensation, it does not seem probable that
the forests sensibly affect the total quantity of precipitation, or the general
mean of atmospheric temperature of the globe, 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,[173] 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 the present geological epoch,
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 former 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 an
appreciable 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
Page 125
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 general 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. 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, and
some apparently well-established exceptions to particular branches of what
appears to be the general law.
One of these occurs both in climates where the cold of winter is severe
enough to freeze the ground to a considerable depth, as in Sweden and the
Northern States of the American Union, and in milder zones, where the face
of the earth is exposed to cold mountain winds, as in some parts of Italy and
of France; for there, as we have seen, the winter is believed to extend itself
into the months which belong to the spring, later than at periods when the
forest covered the greater part of the ground.[174] More causes than one
doubtless contribute to this result; but in the case of Sweden and the United
States, the most obvious explanation of the fact is to be found in the loss of
the shelter afforded to the ground by the thick coating of leaves which the
forest sheds upon it, and the snow which the woods protect 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.[175] It requires many days of mild weather to raise the temperature
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 general 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. 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, and
some apparently well-established exceptions to particular branches of what
appears to be the general law.
One of these occurs both in climates where the cold of winter is severe
enough to freeze the ground to a considerable depth, as in Sweden and the
Northern States of the American Union, and in milder zones, where the face
of the earth is exposed to cold mountain winds, as in some parts of Italy and
of France; for there, as we have seen, the winter is believed to extend itself
into the months which belong to the spring, later than at periods when the
forest covered the greater part of the ground.[174] More causes than one
doubtless contribute to this result; but in the case of Sweden and the United
States, the most obvious explanation of the fact is to be found in the loss of
the shelter afforded to the ground by the thick coating of leaves which the
forest sheds upon it, and the snow which the woods protect 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.[175] It requires many days of mild weather to raise the temperature
Page 126
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 not a popular error to
believe that, where man has substituted his artificial crops for the
spontaneous harvest of nature, spring delays her coming.
In many cases, the apparent change in the period of the seasons is a
purely local phenomenon, which is probably compensated by a higher
temperature in other months, without any real disturbance of the average
thermometrical equilibrium. We may easily suppose that there are
analogous partial deviations from the general law of precipitation; 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 or near it.
But the subject is so exceedingly complex and difficult, that it is safer to
regard it as a historical problem, or at least as what lawyers call a mixed
question of law and fact, than to attempt to decide it upon à priori grounds.
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,
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 not a popular error to
believe that, where man has substituted his artificial crops for the
spontaneous harvest of nature, spring delays her coming.
In many cases, the apparent change in the period of the seasons is a
purely local phenomenon, which is probably compensated by a higher
temperature in other months, without any real disturbance of the average
thermometrical equilibrium. We may easily suppose that there are
analogous partial deviations from the general law of precipitation; 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 or near it.
But the subject is so exceedingly complex and difficult, that it is safer to
regard it as a historical problem, or at least as what lawyers call a mixed
question of law and fact, than to attempt to decide it upon à priori grounds.
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,
Page 127
And where no rain can fall to bless the land,
Because nought grows there.[176]
Before stating the evidence on the general question and citing the
judgments of the learned upon it, however, it is well to remark that the
comparative variety or frequency of inundations in earlier and 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.
There is another important observation which may properly be
introduced here. It is not universally, or even generally true, that the
atmosphere returns its 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;[177]
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
Because nought grows there.[176]
Before stating the evidence on the general question and citing the
judgments of the learned upon it, however, it is well to remark that the
comparative variety or frequency of inundations in earlier and 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.
There is another important observation which may properly be
introduced here. It is not universally, or even generally true, that the
atmosphere returns its 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;[177]
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
Page 128
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.
But I return to the question. Beginning with the latest authorities, I cite a
passage from Clavé.[178] After arguing that we cannot reason from the
climatic effects of the forest in tropical and sub-tropical countries as to its
influence in temperate latitudes, the author proceeds: "The action of the
forests on rain, a consequence of that which they exercise on temperature, is
difficult to estimate in our climate, but is very pronounced in hot countries,
and is established by numerous examples. M. Boussingault states that in the
region comprised between the Bay of Cupica and the Gulf of Guayaquil,
which is covered with immense forests, the rains are almost continual, and
that the mean temperature of this humid country rises hardly to twenty-six
degrees (= 80° Fahr.). M. Blanqui, in his 'Travels in Bulgaria,' informs us
that at Malta rain has become so rare, since the woods were cleared to make
room for the growth of cotton, that at the time of his visit in October, 1841,
not a drop of rain had fallen for three years.[179] The terrible droughts which
desolate the Cape Verd Islands must also be attributed to the destruction of
the forests. In the Island of St. Helena, where the wooded surface has
considerably extended within a few years, it has been observed that the rain
has increased in the same proportion. It is now in quantity double what it
was during the residence of Napoleon. In Egypt, recent plantations have
caused rains, which hitherto were almost unknown."
Schacht[180] observes: "In wooded countries, the atmosphere is
generally humid, and rain and dew fertilize the soil. As the lightning rod
abstracts the electric fluid from the stormy sky, so the forest attracts to itself
the rain from the clouds, which, in falling, refreshes not it alone, but
extends its benefits to the neighboring fields. * * The forest, presenting a
considerable surface for evaporation, gives to its own soil and to all the
adjacent ground an abundant and enlivening dew. There falls, it is true, less
dew on a tall and thick wood than on the surrounding meadows, which,
being more highly heated during the day by the influence of insolation, cool
with greater rapidity by radiation. But it must be remarked, that this
increased deposition of dew on the neighboring fields is partly due to the
forests themselves; for the dense, saturated strata of air which hover over
were covered with the native forest, it would by no means follow that those
woods did not augment the amount of precipitation elsewhere.
But I return to the question. Beginning with the latest authorities, I cite a
passage from Clavé.[178] After arguing that we cannot reason from the
climatic effects of the forest in tropical and sub-tropical countries as to its
influence in temperate latitudes, the author proceeds: "The action of the
forests on rain, a consequence of that which they exercise on temperature, is
difficult to estimate in our climate, but is very pronounced in hot countries,
and is established by numerous examples. M. Boussingault states that in the
region comprised between the Bay of Cupica and the Gulf of Guayaquil,
which is covered with immense forests, the rains are almost continual, and
that the mean temperature of this humid country rises hardly to twenty-six
degrees (= 80° Fahr.). M. Blanqui, in his 'Travels in Bulgaria,' informs us
that at Malta rain has become so rare, since the woods were cleared to make
room for the growth of cotton, that at the time of his visit in October, 1841,
not a drop of rain had fallen for three years.[179] The terrible droughts which
desolate the Cape Verd Islands must also be attributed to the destruction of
the forests. In the Island of St. Helena, where the wooded surface has
considerably extended within a few years, it has been observed that the rain
has increased in the same proportion. It is now in quantity double what it
was during the residence of Napoleon. In Egypt, recent plantations have
caused rains, which hitherto were almost unknown."
Schacht[180] observes: "In wooded countries, the atmosphere is
generally humid, and rain and dew fertilize the soil. As the lightning rod
abstracts the electric fluid from the stormy sky, so the forest attracts to itself
the rain from the clouds, which, in falling, refreshes not it alone, but
extends its benefits to the neighboring fields. * * The forest, presenting a
considerable surface for evaporation, gives to its own soil and to all the
adjacent ground an abundant and enlivening dew. There falls, it is true, less
dew on a tall and thick wood than on the surrounding meadows, which,
being more highly heated during the day by the influence of insolation, cool
with greater rapidity by radiation. But it must be remarked, that this
increased deposition of dew on the neighboring fields is partly due to the
forests themselves; for the dense, saturated strata of air which hover over
Page 129
the woods descend in cool, calm evenings, like clouds, to the valley, and in
the morning, beads of dew sparkle on the leaves of the grass and the flowers
of the field. Forests, in a word, exert, in the interior of continents, an
influence like that of the sea on the climate of islands and of coasts: both
water the soil and thereby insure its fertility." In a note upon this passage,
quoting as authority the Historia de la Conquista de las siete islas de Gran
Canaria, de Juan de Abreu Galindo, 1632, p. 47, he adds: "Old historians
relate that a celebrated laurel in Ferro formerly furnished drinkable water to
the inhabitants of the island. The water flowed from its foliage,
uninterruptedly, drop by drop, and was collected in cisterns. Every morning
the sea breeze drove a cloud toward the wonderful tree, which attracted it to
its huge top," where it was condensed to a liquid form.
In a number of the Missionary Herald, published at Boston, the date of
which I have mislaid, the Rev. Mr. Van Lennep, well known as a competent
observer, gives the following remarkable account of a similar fact witnessed
by him in an excursion to the east of Tocat in Asia Minor:
"In this region, some 3,000 feet above the sea, the trees are mostly oak,
and attain a large size. I noticed an illustration of the influence of trees in
general in collecting moisture. Despite the fog, of a week's duration, the
ground was everywhere perfectly dry. The dry oak leaves, however, had
gathered the water, and the branches and trunks of the trees were more or
less wet. In many cases the water had run down the trunk and moistened the
soil around the roots of the tree. In two places, several trees had each
furnished a small stream of water, and these, uniting, had run upon the road,
so that travellers had to pass through the mud; although, as I said,
everywhere else the ground was perfectly dry. Moreover, the collected
moisture was not sufficient to drop directly from the leaves, but in every
case it ran down the branches and trunk to the ground. Farther on we found
a grove, and at the foot of each tree, on the north side, was a lump of ice,
the water having frozen as it reached the ground. This is a most striking
illustration of the acknowledged influence of trees in collecting moisture;
and one cannot for a moment doubt, that the parched regions which
commence at Sivas, and extend in one direction to the Persian Gulf, and in
another to the Red Sea, were once a fertile garden, teeming with a
prosperous population, before the forests which covered the hillsides were
the morning, beads of dew sparkle on the leaves of the grass and the flowers
of the field. Forests, in a word, exert, in the interior of continents, an
influence like that of the sea on the climate of islands and of coasts: both
water the soil and thereby insure its fertility." In a note upon this passage,
quoting as authority the Historia de la Conquista de las siete islas de Gran
Canaria, de Juan de Abreu Galindo, 1632, p. 47, he adds: "Old historians
relate that a celebrated laurel in Ferro formerly furnished drinkable water to
the inhabitants of the island. The water flowed from its foliage,
uninterruptedly, drop by drop, and was collected in cisterns. Every morning
the sea breeze drove a cloud toward the wonderful tree, which attracted it to
its huge top," where it was condensed to a liquid form.
In a number of the Missionary Herald, published at Boston, the date of
which I have mislaid, the Rev. Mr. Van Lennep, well known as a competent
observer, gives the following remarkable account of a similar fact witnessed
by him in an excursion to the east of Tocat in Asia Minor:
"In this region, some 3,000 feet above the sea, the trees are mostly oak,
and attain a large size. I noticed an illustration of the influence of trees in
general in collecting moisture. Despite the fog, of a week's duration, the
ground was everywhere perfectly dry. The dry oak leaves, however, had
gathered the water, and the branches and trunks of the trees were more or
less wet. In many cases the water had run down the trunk and moistened the
soil around the roots of the tree. In two places, several trees had each
furnished a small stream of water, and these, uniting, had run upon the road,
so that travellers had to pass through the mud; although, as I said,
everywhere else the ground was perfectly dry. Moreover, the collected
moisture was not sufficient to drop directly from the leaves, but in every
case it ran down the branches and trunk to the ground. Farther on we found
a grove, and at the foot of each tree, on the north side, was a lump of ice,
the water having frozen as it reached the ground. This is a most striking
illustration of the acknowledged influence of trees in collecting moisture;
and one cannot for a moment doubt, that the parched regions which
commence at Sivas, and extend in one direction to the Persian Gulf, and in
another to the Red Sea, were once a fertile garden, teeming with a
prosperous population, before the forests which covered the hillsides were
Page 130
cut down—before the cedar and the fir tree were rooted up from the sides of
Lebanon.
"As we now descended the northern side of the watershed, we passed
through the grove of walnut, oak, and black mulberry trees, which shade the
village of Oktab, whose houses, cattle, and ruddy children were indicative
of prosperity."
Coultas thus argues: "The ocean, winds, and woods may be regarded as
the several parts of a grand distillatory apparatus. The sea is the boiler in
which vapor is raised by the solar heat, the winds are the guiding tubes
which carry the vapor with them to the forests where a lower temperature
prevails. This naturally condenses the vapor, and showers of rain are thus
distilled from the cloud masses which float in the atmosphere, by the woods
beneath them."[181]
Sir John F. W. Herschel enumerates among "the influences unfavorable
to rain," "absence of vegetation in warm climates, and especially of trees.
This is, no doubt," continues he, "one of the reasons of the extreme aridity
of Spain. The hatred of a Spaniard toward a tree is proverbial. Many
districts in France have been materially injured by denudation (Earl of
Lovelace on Climate, etc.), and, on the other hand, rain has become more
frequent in Egypt since the more vigorous cultivation of the palm tree."
Hohenstein remarks: "With respect to the temperature in the forest, I
have already observed that, at certain times of the day and of the year, it is
less than in the open field. Hence the woods may, in the daytime, in summer
and toward the end of winter, tend to increase the fall of rain; but it is
otherwise in summer nights and at the beginning of winter, when there is a
higher temperature in the forest, which is not favorable to that effect. * * *
The wood is, further, like the mountain, a mechanical obstruction to the
motion of rain clouds, and, as it checks them in their course, it gives them
occasion to deposit their water. These considerations render it probable that
the forest increases the quantity of rain; but they do not establish the
certainty of this conclusion, because we have no positive numerical data to
produce on the depression of temperature, and the humidity of the air in the
woods."[182]
Lebanon.
"As we now descended the northern side of the watershed, we passed
through the grove of walnut, oak, and black mulberry trees, which shade the
village of Oktab, whose houses, cattle, and ruddy children were indicative
of prosperity."
Coultas thus argues: "The ocean, winds, and woods may be regarded as
the several parts of a grand distillatory apparatus. The sea is the boiler in
which vapor is raised by the solar heat, the winds are the guiding tubes
which carry the vapor with them to the forests where a lower temperature
prevails. This naturally condenses the vapor, and showers of rain are thus
distilled from the cloud masses which float in the atmosphere, by the woods
beneath them."[181]
Sir John F. W. Herschel enumerates among "the influences unfavorable
to rain," "absence of vegetation in warm climates, and especially of trees.
This is, no doubt," continues he, "one of the reasons of the extreme aridity
of Spain. The hatred of a Spaniard toward a tree is proverbial. Many
districts in France have been materially injured by denudation (Earl of
Lovelace on Climate, etc.), and, on the other hand, rain has become more
frequent in Egypt since the more vigorous cultivation of the palm tree."
Hohenstein remarks: "With respect to the temperature in the forest, I
have already observed that, at certain times of the day and of the year, it is
less than in the open field. Hence the woods may, in the daytime, in summer
and toward the end of winter, tend to increase the fall of rain; but it is
otherwise in summer nights and at the beginning of winter, when there is a
higher temperature in the forest, which is not favorable to that effect. * * *
The wood is, further, like the mountain, a mechanical obstruction to the
motion of rain clouds, and, as it checks them in their course, it gives them
occasion to deposit their water. These considerations render it probable that
the forest increases the quantity of rain; but they do not establish the
certainty of this conclusion, because we have no positive numerical data to
produce on the depression of temperature, and the humidity of the air in the
woods."[182]
Page 131
Barth presents the following view of the subject: "The ground in the
forest, as well as the atmospheric stratum over it, continues humid after the
woodless districts have lost their moisture; and the air, charged with the
humidity drawn from them, is usually carried away by the winds before it
has deposited itself in a condensed form on the earth. Trees constantly
transpire through their leaves a great quantity of moisture, which they partly
absorb again by the same organs, while the greatest part of their supply is
pumped up through their widely ramifying roots from considerable depths
in the ground. Thus a constant evaporation is produced, which keeps the
forest atmosphere moist even in long droughts, when all other sources of
humidity in the forest itself are dried up. * * * Little is required to compel
the stratum of air resting upon a wood to give up its moisture, which thus,
as rain, fog, or dew, is returned to the forest. * * * The warm, moist currents
of air which come from other regions are cooled as they approach the wood
by its less heated atmosphere, and obliged to let fall the humidity with
which they are charged. The woods contribute to the same effect by
mechanically impeding the motion of fog and rain cloud, whose particles
are thus accumulated and condensed to rain. The forest thus has a greater
power than the open ground to retain within its own limits already existing
humidity, and to preserve it, and it attracts and collects that which the wind
brings it from elsewhere, and forces it to deposit itself as rain or other
precipitation. * * * In consequence of these relations of the forest to
humidity, it follows that wooded districts have both more frequent and more
abundant rain, and in general are more humid, than woodless regions; for
what is true of the woods themselves, in this respect, is true also of their
treeless neighborhood, which, in consequence of the ready mobility of the
air and its constant changes, receives a share of the characteristics of the
forest atmosphere, coolness and moisture. * * * When the districts stripped
of trees have long been deprived of rain and dew, * * * and the grass and
the fruits of the field are ready to wither, the grounds which are surrounded
by woods are green and flourishing. By night they are refreshed with dew,
which is never wanting in the moist air of the forest, and in due season they
are watered by a beneficent shower, or a mist which rolls slowly over
them."[183]
Asbjörnsen, after adducing the familiar theoretical arguments on this
point, adds: "The rainless territories in Peru and North Africa establish this
forest, as well as the atmospheric stratum over it, continues humid after the
woodless districts have lost their moisture; and the air, charged with the
humidity drawn from them, is usually carried away by the winds before it
has deposited itself in a condensed form on the earth. Trees constantly
transpire through their leaves a great quantity of moisture, which they partly
absorb again by the same organs, while the greatest part of their supply is
pumped up through their widely ramifying roots from considerable depths
in the ground. Thus a constant evaporation is produced, which keeps the
forest atmosphere moist even in long droughts, when all other sources of
humidity in the forest itself are dried up. * * * Little is required to compel
the stratum of air resting upon a wood to give up its moisture, which thus,
as rain, fog, or dew, is returned to the forest. * * * The warm, moist currents
of air which come from other regions are cooled as they approach the wood
by its less heated atmosphere, and obliged to let fall the humidity with
which they are charged. The woods contribute to the same effect by
mechanically impeding the motion of fog and rain cloud, whose particles
are thus accumulated and condensed to rain. The forest thus has a greater
power than the open ground to retain within its own limits already existing
humidity, and to preserve it, and it attracts and collects that which the wind
brings it from elsewhere, and forces it to deposit itself as rain or other
precipitation. * * * In consequence of these relations of the forest to
humidity, it follows that wooded districts have both more frequent and more
abundant rain, and in general are more humid, than woodless regions; for
what is true of the woods themselves, in this respect, is true also of their
treeless neighborhood, which, in consequence of the ready mobility of the
air and its constant changes, receives a share of the characteristics of the
forest atmosphere, coolness and moisture. * * * When the districts stripped
of trees have long been deprived of rain and dew, * * * and the grass and
the fruits of the field are ready to wither, the grounds which are surrounded
by woods are green and flourishing. By night they are refreshed with dew,
which is never wanting in the moist air of the forest, and in due season they
are watered by a beneficent shower, or a mist which rolls slowly over
them."[183]
Asbjörnsen, after adducing the familiar theoretical arguments on this
point, adds: "The rainless territories in Peru and North Africa establish this
Page 132
conclusion, and numerous other examples show that woods exert an
influence in producing rain, and that rain fails where they are wanting; for
many countries have, by the destruction of the forests, been deprived of
rain, moisture, springs, and watercourses, which are necessary for vegetable
growth. * * * The narratives of travellers show the deplorable consequences
of felling the woods in the Island of Trinidad, Martinique, San Domingo,
and indeed, in almost the entire West Indian group. * * * In Palestine and
many other parts of Asia and Northern Africa, which in ancient times were
the granaries of Europe, fertile and populous, similar consequences have
been experienced. These lands are now deserts, and it is the destruction of
the forests alone which has produced this desolation. * * * In Southern
France, many districts have, from the same cause, become barren wastes of
stone, and the cultivation of the vine and the olive has suffered severely
since the baring of the neighboring mountains. Since the extensive clearings
between the Spree and the Oder, the inhabitants complain that the clover
crop is much less productive than before. On the other hand, examples of
the beneficial influence of planting and restoring the woods are not
wanting. In Scotland, where many miles square have been planted with
trees, this effect has been manifest, and similar observations have been
made in several places in Southern France. In Lower Egypt, both at Cairo
and near Alexandria, rain rarely fell in considerable quantity—for example,
during the French occupation of Egypt, about 1798, it did not rain for
sixteen months—but since Mehemet Aali and Ibrahim Pacha executed their
vast plantations (the former alone having planted more than twenty millions
of olive and fig trees, cottonwood, oranges, acacias, planes, &c.), there now
falls a good deal of rain, especially along the coast, in the months of
November, December, and January; and even at Cairo it rains both oftener
and more abundantly, so that real showers are no rarity."[184]
Babinet, in one of his lectures,[185] cites the supposed fact of the
increase of rain in Egypt in consequence of the planting of trees, and thus
remarks upon it: "A few years ago it never rained in Lower Egypt. The
constant north winds, which almost exclusively prevail there, passed
without obstruction over a surface bare of vegetation. Grain was kept on the
roofs in Alexandria, without being covered or otherwise protected from
injury by the atmosphere; but since the making of plantations, an obstacle
has been created which retards the current of air from the north. The air thus
influence in producing rain, and that rain fails where they are wanting; for
many countries have, by the destruction of the forests, been deprived of
rain, moisture, springs, and watercourses, which are necessary for vegetable
growth. * * * The narratives of travellers show the deplorable consequences
of felling the woods in the Island of Trinidad, Martinique, San Domingo,
and indeed, in almost the entire West Indian group. * * * In Palestine and
many other parts of Asia and Northern Africa, which in ancient times were
the granaries of Europe, fertile and populous, similar consequences have
been experienced. These lands are now deserts, and it is the destruction of
the forests alone which has produced this desolation. * * * In Southern
France, many districts have, from the same cause, become barren wastes of
stone, and the cultivation of the vine and the olive has suffered severely
since the baring of the neighboring mountains. Since the extensive clearings
between the Spree and the Oder, the inhabitants complain that the clover
crop is much less productive than before. On the other hand, examples of
the beneficial influence of planting and restoring the woods are not
wanting. In Scotland, where many miles square have been planted with
trees, this effect has been manifest, and similar observations have been
made in several places in Southern France. In Lower Egypt, both at Cairo
and near Alexandria, rain rarely fell in considerable quantity—for example,
during the French occupation of Egypt, about 1798, it did not rain for
sixteen months—but since Mehemet Aali and Ibrahim Pacha executed their
vast plantations (the former alone having planted more than twenty millions
of olive and fig trees, cottonwood, oranges, acacias, planes, &c.), there now
falls a good deal of rain, especially along the coast, in the months of
November, December, and January; and even at Cairo it rains both oftener
and more abundantly, so that real showers are no rarity."[184]
Babinet, in one of his lectures,[185] cites the supposed fact of the
increase of rain in Egypt in consequence of the planting of trees, and thus
remarks upon it: "A few years ago it never rained in Lower Egypt. The
constant north winds, which almost exclusively prevail there, passed
without obstruction over a surface bare of vegetation. Grain was kept on the
roofs in Alexandria, without being covered or otherwise protected from
injury by the atmosphere; but since the making of plantations, an obstacle
has been created which retards the current of air from the north. The air thus
Page 133
checked, accumulates, dilates, cools, and yields rain.[186] The forests of the
Vosges and Ardennes produce the same effects in the north east of France,
and send us a great river, the Meuse, which is as remarkable for its volume
as for the small extent of its basin. With respect to the retardation of the
atmospheric currents, and the effects of that retardation, one of my
illustrious colleagues, M. Mignet, who is not less a profound thinker than an
eloquent writer, suggested to me that, to produce rain, a forest was as good
as a mountain, and this is literally true."
Monestier-Savignat arrives at this conclusion: "Forests on the one hand
diminish evaporation; on the other, they act on the atmosphere as
refrigerating causes. The second scale of the balance predominates over the
other, for it is established that in wooded countries it rains oftener, and that,
the quantity of rain being equal, they are more humid."[187]
Boussingault—whose observations on the drying up of lakes and
springs, from the destruction of the woods, in tropical America, have often
been cited as a conclusive proof that the quantity of rain was thereby
diminished—after examining the question with much care, remarks: "In my
judgment it is settled that very large clearings must diminish the annual fall
of rain in a country;" and on a subsequent page, he concludes that, "arguing
from meteorological facts collected in the equinoctial regions, there is
reason to presume that clearings diminish the annual fall of rain."[188]
The same eminent author proposes series of observations on the level of
natural lakes, especially on those without outlet, as a means of determining
the increase or diminution of precipitation in their basins, and, of course, of
measuring the effect of clearing when such operations take place within
those basins. But it must be observed that lakes without a visible outlet are
of very rare occurrence, and besides, where no superficial conduit for the
discharge of lacustrine waters exists, we can seldom or never be sure that
nature has not provided subterranean channels for their escape. Indeed,
when we consider that most earths, and even some rocks under great
hydrostatic pressure, are freely permeable by water, and that fissures are
frequent in almost all rocky strata, it is evident that we cannot know in what
proportion the depression of the level of a lake is to be ascribed to
infiltration, to percolation, or to evaporation.[189] Further, we are, in general,
as little able to affirm that a given lake derives all its water from the fall of
Vosges and Ardennes produce the same effects in the north east of France,
and send us a great river, the Meuse, which is as remarkable for its volume
as for the small extent of its basin. With respect to the retardation of the
atmospheric currents, and the effects of that retardation, one of my
illustrious colleagues, M. Mignet, who is not less a profound thinker than an
eloquent writer, suggested to me that, to produce rain, a forest was as good
as a mountain, and this is literally true."
Monestier-Savignat arrives at this conclusion: "Forests on the one hand
diminish evaporation; on the other, they act on the atmosphere as
refrigerating causes. The second scale of the balance predominates over the
other, for it is established that in wooded countries it rains oftener, and that,
the quantity of rain being equal, they are more humid."[187]
Boussingault—whose observations on the drying up of lakes and
springs, from the destruction of the woods, in tropical America, have often
been cited as a conclusive proof that the quantity of rain was thereby
diminished—after examining the question with much care, remarks: "In my
judgment it is settled that very large clearings must diminish the annual fall
of rain in a country;" and on a subsequent page, he concludes that, "arguing
from meteorological facts collected in the equinoctial regions, there is
reason to presume that clearings diminish the annual fall of rain."[188]
The same eminent author proposes series of observations on the level of
natural lakes, especially on those without outlet, as a means of determining
the increase or diminution of precipitation in their basins, and, of course, of
measuring the effect of clearing when such operations take place within
those basins. But it must be observed that lakes without a visible outlet are
of very rare occurrence, and besides, where no superficial conduit for the
discharge of lacustrine waters exists, we can seldom or never be sure that
nature has not provided subterranean channels for their escape. Indeed,
when we consider that most earths, and even some rocks under great
hydrostatic pressure, are freely permeable by water, and that fissures are
frequent in almost all rocky strata, it is evident that we cannot know in what
proportion the depression of the level of a lake is to be ascribed to
infiltration, to percolation, or to evaporation.[189] Further, we are, in general,
as little able to affirm that a given lake derives all its water from the fall of
Page 134
rain within its geographical basin, or that it receives all the water that falls
in that basin except what evaporates from the ground, as we are to show
that all its superfluous water is carried off by visible channels and by
evaporation.
Suppose the strata of the mountains on two sides of a lake, east and
west, to be tilted in the same direction, and that those of the hill on the east
side incline toward the lake, those of that on the west side from it. In this
case a large proportion of the rain which falls on the eastern slope of the
eastern hill may find its way between the strata to the lake, and an equally
large proportion of the precipitation upon the eastern slope of the western
ridge may escape out of the basin by similar channels. In such case the
clearing of the outer slopes of either or both mountains, while the forests of
the inner declivities remained intact, might affect the quantity of water
received by the lake, and it would always be impossible to know to what
territorial extent influences thus affecting the level of a lake might reach.
Boussingault admits that extensive clearing below an alpine lake, even at a
considerable distance, might affect the level of its waters. How it would
produce this influence he does not inform us, but, as he says nothing of the
natural subterranean drainage of surface waters, it is to be presumed that he
refers to the supposed diminution of the quantity of rain from the removal
of the forest, which might manifest itself at a point more elevated than the
cause which occasioned it. The elevation or depression of the level of
natural lakes, then, cannot be relied upon as a proof, still less as a measure
of an increase or diminution in the fall of rain within their geographical
basins, resulting from the felling of the woods which covered them; though
such phenomena afford very strong presumptive evidence that the supply of
water is somehow augmented or lessened. The supply is, in most cases,
derived much less from the precipitation which falls directly upon the
surface of lakes, than from waters which flow above or under the ground
around them, and which, in the latter case, often come from districts not
comprised within what superficial geography would regard as belonging to
the lake basins.
It is, upon the whole, evident that the question can hardly be determined
except by the comparison of pluviometrical observations made at a given
station before and after the destruction of the woods. Such observations,
unhappily, are scarcely to be found, and the opportunity for making them is
in that basin except what evaporates from the ground, as we are to show
that all its superfluous water is carried off by visible channels and by
evaporation.
Suppose the strata of the mountains on two sides of a lake, east and
west, to be tilted in the same direction, and that those of the hill on the east
side incline toward the lake, those of that on the west side from it. In this
case a large proportion of the rain which falls on the eastern slope of the
eastern hill may find its way between the strata to the lake, and an equally
large proportion of the precipitation upon the eastern slope of the western
ridge may escape out of the basin by similar channels. In such case the
clearing of the outer slopes of either or both mountains, while the forests of
the inner declivities remained intact, might affect the quantity of water
received by the lake, and it would always be impossible to know to what
territorial extent influences thus affecting the level of a lake might reach.
Boussingault admits that extensive clearing below an alpine lake, even at a
considerable distance, might affect the level of its waters. How it would
produce this influence he does not inform us, but, as he says nothing of the
natural subterranean drainage of surface waters, it is to be presumed that he
refers to the supposed diminution of the quantity of rain from the removal
of the forest, which might manifest itself at a point more elevated than the
cause which occasioned it. The elevation or depression of the level of
natural lakes, then, cannot be relied upon as a proof, still less as a measure
of an increase or diminution in the fall of rain within their geographical
basins, resulting from the felling of the woods which covered them; though
such phenomena afford very strong presumptive evidence that the supply of
water is somehow augmented or lessened. The supply is, in most cases,
derived much less from the precipitation which falls directly upon the
surface of lakes, than from waters which flow above or under the ground
around them, and which, in the latter case, often come from districts not
comprised within what superficial geography would regard as belonging to
the lake basins.
It is, upon the whole, evident that the question can hardly be determined
except by the comparison of pluviometrical observations made at a given
station before and after the destruction of the woods. Such observations,
unhappily, are scarcely to be found, and the opportunity for making them is
Page 135
rapidly passing away, except so far as a converse series might be collected
in countries—France, for example—where forest plantation is now going
on upon a large scale. The Smithsonian Institution at Washington is well
situated for directing the attention of observers in the newer territory of the
United States to this subject, and it is to be hoped that it will not fail to avail
itself of its facilities for this purpose.
Numerous other authorities might be cited in support of the proposition
that forests tend, at least in certain latitudes and at certain seasons, to
produce rain; but though the arguments of the advocates of this doctrine are
very plausible, not to say convincing, their opinions are rather à priori
conclusions from general meteorological laws, than deductions from facts
of observation, and it is remarkable that there is so little direct evidence on
the subject.
On the other hand, Foissac expresses the opinion that forests have no
influence on precipitation, beyond that of promoting the deposit of dew in
their vicinity, and he states, as a fact of experience, that the planting of large
vegetables, and especially of trees, is a very efficient means of drying
morasses, because the plants draw from the earth a quantity of water larger
than the average annual fall of rain.[190] Klöden, admitting that the rivers
Oder and Elbe have diminished in quantity of water, the former since 1778,
the latter since 1828, denies that the diminution of volume is to be ascribed
to a decrease of precipitation in consequence of the felling of the forests,
and states, what other physicists confirm, that, during the same period,
meteorological records in various parts of Europe show rather an
augmentation than a reduction of rain.[191]
The observations of Belgrand tend to show, contrary to the general
opinion, that less rain falls in wooded than in denuded districts. He
compared the precipitation for the year 1852, at Vezelay in the valley of the
Bouchat, and at Avallon in the valley of the Grenetière. At the first of these
places it was 881 millimètres, at the latter 581 millimètres. The two cities
are not more than eight miles apart. They are at the same altitude, and it is
stated that the only difference in their geographical conditions consists in
the different proportions of forest and cultivated country around them, the
basin of the Bouchat being entirely bare, while that of the Grenetière is well
in countries—France, for example—where forest plantation is now going
on upon a large scale. The Smithsonian Institution at Washington is well
situated for directing the attention of observers in the newer territory of the
United States to this subject, and it is to be hoped that it will not fail to avail
itself of its facilities for this purpose.
Numerous other authorities might be cited in support of the proposition
that forests tend, at least in certain latitudes and at certain seasons, to
produce rain; but though the arguments of the advocates of this doctrine are
very plausible, not to say convincing, their opinions are rather à priori
conclusions from general meteorological laws, than deductions from facts
of observation, and it is remarkable that there is so little direct evidence on
the subject.
On the other hand, Foissac expresses the opinion that forests have no
influence on precipitation, beyond that of promoting the deposit of dew in
their vicinity, and he states, as a fact of experience, that the planting of large
vegetables, and especially of trees, is a very efficient means of drying
morasses, because the plants draw from the earth a quantity of water larger
than the average annual fall of rain.[190] Klöden, admitting that the rivers
Oder and Elbe have diminished in quantity of water, the former since 1778,
the latter since 1828, denies that the diminution of volume is to be ascribed
to a decrease of precipitation in consequence of the felling of the forests,
and states, what other physicists confirm, that, during the same period,
meteorological records in various parts of Europe show rather an
augmentation than a reduction of rain.[191]
The observations of Belgrand tend to show, contrary to the general
opinion, that less rain falls in wooded than in denuded districts. He
compared the precipitation for the year 1852, at Vezelay in the valley of the
Bouchat, and at Avallon in the valley of the Grenetière. At the first of these
places it was 881 millimètres, at the latter 581 millimètres. The two cities
are not more than eight miles apart. They are at the same altitude, and it is
stated that the only difference in their geographical conditions consists in
the different proportions of forest and cultivated country around them, the
basin of the Bouchat being entirely bare, while that of the Grenetière is well
Page 136
wooded.[192] Observations in the same valleys, considered with reference to
the seasons, show the following pluviometric results:
FOR LA GRENETIÈRE.
February, 1852, 42.2 millimètres precipitation.
November, " 23.8 " "
January, 1853, 35.4 " "
Total, 106.4 in three cold months.
September, 1851, 27.1 millimètres precipitation.
May, 1852, 20.9 " "
June, " 56.3 " "
July, " 22.8 " "
September, " 22.8 " "
Total, 149.9 in five warm months.
FOR LE BOUCHAT.
February, 1852, 51.3 millimètres precipitation.
November, " 36.6 " "
January, 1853, 92.0 " "
Total, 179.9 in three cold months.
September, 1851, 43.8 millimètres precipitation.
May, 1852, 13.2 " "
June, " 55.5 " "
July, " 19.5 " "
September, " 26.5 " "
Total, 158.5 in five warm months.
These observations, so far as they go, seem to show that more rain falls
in cleared than in wooded countries, but this result is so contrary to what
has been generally accepted as a theoretical conclusion, that further
experiment is required to determine the question.
Becquerel—whose treatise on the climatic effects of the destruction of
the forest is the fullest general discussion of that subject known to me—
the seasons, show the following pluviometric results:
FOR LA GRENETIÈRE.
February, 1852, 42.2 millimètres precipitation.
November, " 23.8 " "
January, 1853, 35.4 " "
Total, 106.4 in three cold months.
September, 1851, 27.1 millimètres precipitation.
May, 1852, 20.9 " "
June, " 56.3 " "
July, " 22.8 " "
September, " 22.8 " "
Total, 149.9 in five warm months.
FOR LE BOUCHAT.
February, 1852, 51.3 millimètres precipitation.
November, " 36.6 " "
January, 1853, 92.0 " "
Total, 179.9 in three cold months.
September, 1851, 43.8 millimètres precipitation.
May, 1852, 13.2 " "
June, " 55.5 " "
July, " 19.5 " "
September, " 26.5 " "
Total, 158.5 in five warm months.
These observations, so far as they go, seem to show that more rain falls
in cleared than in wooded countries, but this result is so contrary to what
has been generally accepted as a theoretical conclusion, that further
experiment is required to determine the question.
Becquerel—whose treatise on the climatic effects of the destruction of
the forest is the fullest general discussion of that subject known to me—
Page 137
does not examine this particular point, and as, in the summary of the results
of his investigations, he does not ascribe to the forest any influence upon
precipitation, the presumption is that he rejects the doctrine of its
importance as an agent in producing the fall of rain.
The effect of the forest on precipitation, then, is not entirely free from
doubt, and we cannot positively affirm that the total annual quantity of rain
is 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 promote the frequency of showers, and, if
they do not augment the amount of precipitation, they equalize its
distribution through the different seasons.
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 watercourses,
are much less disputable as well as more easily estimated, and much 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 abstraction of water by its roots affects the quantity of
that fluid 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
of his investigations, he does not ascribe to the forest any influence upon
precipitation, the presumption is that he rejects the doctrine of its
importance as an agent in producing the fall of rain.
The effect of the forest on precipitation, then, is not entirely free from
doubt, and we cannot positively affirm that the total annual quantity of rain
is 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 promote the frequency of showers, and, if
they do not augment the amount of precipitation, they equalize its
distribution through the different seasons.
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 watercourses,
are much less disputable as well as more easily estimated, and much 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 abstraction of water by its roots affects the quantity of
that fluid 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
Page 138
insolation 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 would be more humid than that of cleared land. This
agrees with experience. The soil of the 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.
Influence of the Forest on the Flow of Springs.
It is well established that the protection afforded by the forest against
the escape of moisture from its soil, 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 watercourses 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 ten or
twelve 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 it, and has since continued to flow uninterruptedly. The uplands in
the Atlantic States formerly abounded in sources and rills, but in many parts
of those States which have been cleared for above a generation or two, the
hill pastures now suffer severely from drought, and in dry seasons no longer
afford either water or herbage for cattle.
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 would be more humid than that of cleared land. This
agrees with experience. The soil of the 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.
Influence of the Forest on the Flow of Springs.
It is well established that the protection afforded by the forest against
the escape of moisture from its soil, 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 watercourses 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 ten or
twelve 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 it, and has since continued to flow uninterruptedly. The uplands in
the Atlantic States formerly abounded in sources and rills, but in many parts
of those States which have been cleared for above a generation or two, the
hill pastures now suffer severely from drought, and in dry seasons no longer
afford either water or herbage for cattle.
Page 139
Foissac, indeed, quotes from the elder Pliny (Nat. Hist., xxxi, c. 30) a
passage affirming that the felling of the woods gives rise to springs which
did not exist before because the water of the soil was absorbed by the trees;
and the same meteorologist declares, as I observed in treating of the effect
of the forest on atmospheric humidity, that the planting of trees tends to
drain marshy ground, because the roots absorb more water than falls from
the air. But Pliny's statement rests on very doubtful authority, and Foissac
cites no evidence in support of his own proposition.[193] In the American
States, it is always observed that clearing the ground not only causes
running springs to disappear, but dries up the stagnant pools 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 New England and the other Northern States.
Almost every treatise on the economy of the forest adduces numerous
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 to bring forward further evidence on this point.[194] But the
subject is of too much practical importance and of too great philosophical
interest to be summarily disposed of; and it ought particularly to be noticed
that there is at least one case—that of some loose soils which, when bared
of wood, very rapidly absorb and transmit to lower strata the water they
receive from the atmosphere, as argued by Vallès[195]—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 flowed off without penetrating
through the superficial layers of leaves upon the ground—as, in very heavy
showers, it sometimes does—or 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,
passage affirming that the felling of the woods gives rise to springs which
did not exist before because the water of the soil was absorbed by the trees;
and the same meteorologist declares, as I observed in treating of the effect
of the forest on atmospheric humidity, that the planting of trees tends to
drain marshy ground, because the roots absorb more water than falls from
the air. But Pliny's statement rests on very doubtful authority, and Foissac
cites no evidence in support of his own proposition.[193] In the American
States, it is always observed that clearing the ground not only causes
running springs to disappear, but dries up the stagnant pools 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 New England and the other Northern States.
Almost every treatise on the economy of the forest adduces numerous
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 to bring forward further evidence on this point.[194] But the
subject is of too much practical importance and of too great philosophical
interest to be summarily disposed of; and it ought particularly to be noticed
that there is at least one case—that of some loose soils which, when bared
of wood, very rapidly absorb and transmit to lower strata the water they
receive from the atmosphere, as argued by Vallès[195]—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 flowed off without penetrating
through the superficial layers of leaves upon the ground—as, in very heavy
showers, it sometimes does—or 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,
Page 140
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 only under very
uncommon circumstances that rain water runs off over the surface of forest
ground instead of sinking into it, and very rarely the case that such a soil as
has just been supposed is covered by a layer of vegetable earth thick 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
of authority to be attached to the testimony, among the most important yet
recorded. They are embodied in the fourth section of the twentieth chapter
of that writer's Économie Rurale, and I have already referred to them on
page 191 for another purpose. The interest of the question will justify me in
giving, in Boussingault's own words, the facts and some of the remarks with
which he accompanies the details of them: "In many localities," he
observes,[196] "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 is
thought to have 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.
"These facts would indicate that, where clearings have been made, it
rains less than formerly, and this is the generally received opinion. * * * But
while the facts I have stated have been established, it has been observed, at
the same time, that, since the clearing of the mountains, the rivers and the
torrents, which seemed to have lost a part of their water, sometimes
suddenly swell, and that, occasionally, to a degree which causes great
disasters. Besides, after violent storms, springs which had become almost
exhausted have been observed to burst out with impetuosity, and soon after
running spring. But such instances are doubtless too rare to form a frequent
or an important exception to the general law, because it is only under very
uncommon circumstances that rain water runs off over the surface of forest
ground instead of sinking into it, and very rarely the case that such a soil as
has just been supposed is covered by a layer of vegetable earth thick 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
of authority to be attached to the testimony, among the most important yet
recorded. They are embodied in the fourth section of the twentieth chapter
of that writer's Économie Rurale, and I have already referred to them on
page 191 for another purpose. The interest of the question will justify me in
giving, in Boussingault's own words, the facts and some of the remarks with
which he accompanies the details of them: "In many localities," he
observes,[196] "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 is
thought to have 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.
"These facts would indicate that, where clearings have been made, it
rains less than formerly, and this is the generally received opinion. * * * But
while the facts I have stated have been established, it has been observed, at
the same time, that, since the clearing of the mountains, the rivers and the
torrents, which seemed to have lost a part of their water, sometimes
suddenly swell, and that, occasionally, to a degree which causes great
disasters. Besides, after violent storms, springs which had become almost
exhausted have been observed to burst out with impetuosity, and soon after
Page 141
to dry up again. These latter observations, it will be easily conceived, warn
us not to admit hastily the common opinion that the felling of the woods
lessens the quantity of rain; for not only is it very possible that the quantity
of rain has not changed, but the mean volume of running water may have
remained the same, in spite of the appearance of drought presented by the
rivers and springs, at certain periods of the year. Perhaps the only difference
would be that the flow of the same quantity of water becomes more
irregular in consequence of clearing. For instance: if the low water of the
Rhone during one part of the year were exactly compensated by a sufficient
number of floods, it would follow that this river would convey to the
Mediterranean the same volume of water which it carried to that sea in
ancient times, before the period when the countries near its source were
stripped of their woods, and when, probably, its mean depth was not subject
to so great variations as in our days. If this were so, the forests would have
this value—that of regulating, of economizing in a certain sort, the drainage
of the rain water.
"If running streams really become rarer in proportion as clearing is
extended, it follows either that the rain is less abundant, or that evaporation
is greatly favored by a surface which is no longer protected by trees against
the rays of the sun and the wind. These two causes, acting in the same
direction, must often be cumulative in their effects, and before we attempt
to fix the value of each, it is proper to inquire whether it is an established
fact that running waters diminish on the surface of a country in which
extensive clearing is going on; in a word, to examine whether an apparent
fact has not been mistaken for a real one. 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. * * * I shall attach no value except to facts which have taken place
under the eye of man, as it is the influence of his labors on the
meteorological condition of the atmosphere which I propose to estimate.
What I am about to detail has been observed particularly in America, but I
shall endeavor to establish, that what I believe to be true of America would
be equally so for any other continent.
"One of the most interesting parts of Venezuela is, no doubt, the valley
of Aragua. Situated at a short distance from the coast, and endowed, from
its elevation, with various climates and a soil of unexampled fertility, its
us not to admit hastily the common opinion that the felling of the woods
lessens the quantity of rain; for not only is it very possible that the quantity
of rain has not changed, but the mean volume of running water may have
remained the same, in spite of the appearance of drought presented by the
rivers and springs, at certain periods of the year. Perhaps the only difference
would be that the flow of the same quantity of water becomes more
irregular in consequence of clearing. For instance: if the low water of the
Rhone during one part of the year were exactly compensated by a sufficient
number of floods, it would follow that this river would convey to the
Mediterranean the same volume of water which it carried to that sea in
ancient times, before the period when the countries near its source were
stripped of their woods, and when, probably, its mean depth was not subject
to so great variations as in our days. If this were so, the forests would have
this value—that of regulating, of economizing in a certain sort, the drainage
of the rain water.
"If running streams really become rarer in proportion as clearing is
extended, it follows either that the rain is less abundant, or that evaporation
is greatly favored by a surface which is no longer protected by trees against
the rays of the sun and the wind. These two causes, acting in the same
direction, must often be cumulative in their effects, and before we attempt
to fix the value of each, it is proper to inquire whether it is an established
fact that running waters diminish on the surface of a country in which
extensive clearing is going on; in a word, to examine whether an apparent
fact has not been mistaken for a real one. 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. * * * I shall attach no value except to facts which have taken place
under the eye of man, as it is the influence of his labors on the
meteorological condition of the atmosphere which I propose to estimate.
What I am about to detail has been observed particularly in America, but I
shall endeavor to establish, that what I believe to be true of America would
be equally so for any other continent.
"One of the most interesting parts of Venezuela is, no doubt, the valley
of Aragua. Situated at a short distance from the coast, and endowed, from
its elevation, with various climates and a soil of unexampled fertility, its
Page 142
agriculture embraces at once the crops suited to tropical regions and to
Europe. Wheat succeeds well on the heights of Victoria. Bounded on the
north by the coast chain, on the south by a system of mountains connected
with the Llanos, the valley is shut in on the east and the west by lines of
hills which completely close it. In consequence of this singular
configuration, the rivers which rise within it, having no outlet to the ocean,
form, by their union, the beautiful Lake of Tacarigua or Valencia. This lake,
according to Humboldt, is larger than that of Neufchâtel; it is at an elevation
of 439 mètres [= 1,460 English feet] above the sea, and its greatest length
does not exceed two leagues and a half [= seven 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 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 mètres [= 3⅓ 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 of cotton, bananas, and sugar cane;
and buildings erected near the lake showed the sinking of the water from
year to year. In 1796, new islands made their appearance. An important
military point, 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, some mètres 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, after a careful
examination of the locality, the distinguished traveller 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. * * *
Europe. Wheat succeeds well on the heights of Victoria. Bounded on the
north by the coast chain, on the south by a system of mountains connected
with the Llanos, the valley is shut in on the east and the west by lines of
hills which completely close it. In consequence of this singular
configuration, the rivers which rise within it, having no outlet to the ocean,
form, by their union, the beautiful Lake of Tacarigua or Valencia. This lake,
according to Humboldt, is larger than that of Neufchâtel; it is at an elevation
of 439 mètres [= 1,460 English feet] above the sea, and its greatest length
does not exceed two leagues and a half [= seven 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 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 mètres [= 3⅓ 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 of cotton, bananas, and sugar cane;
and buildings erected near the lake showed the sinking of the water from
year to year. In 1796, new islands made their appearance. An important
military point, 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, some mètres 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, after a careful
examination of the locality, the distinguished traveller 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. * * *
Page 143
"In 1800, the valley of Aragua possessed a population as dense as that
of any of the best-peopled parts of France. * * * Such was the prosperous
condition of this fine country when Humboldt occupied the Hacienda de
Cura.
"Twenty-two years later, I explored the valley of Aragua, fixing my
residence in the little town of Maracay. 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 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, important political
events had occurred. Venezuela no longer belonged to Spain. The peaceful
valley of Aragua had been the theatre of bloody struggles, and a war of
extermination 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.
"At the time of the growing prosperity of the valley of Aragua, the
principal affluents of the lake were diverted, to serve for irrigation, and the
rivers were dry for more than six months of the year. At the period of my
visit, their waters, no longer employed, flowed freely."
Boussingault proceeds to state that two lakes near Ubate in New
Granada, at an elevation of 2,562 mètres (= 8,500 English feet), where there
is a constant temperature of 14° to 16° centigrade [= 57°, 61° Fahrenheit],
had formed but one, a century before his visit; that the waters were
of any of the best-peopled parts of France. * * * Such was the prosperous
condition of this fine country when Humboldt occupied the Hacienda de
Cura.
"Twenty-two years later, I explored the valley of Aragua, fixing my
residence in the little town of Maracay. 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 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, important political
events had occurred. Venezuela no longer belonged to Spain. The peaceful
valley of Aragua had been the theatre of bloody struggles, and a war of
extermination 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.
"At the time of the growing prosperity of the valley of Aragua, the
principal affluents of the lake were diverted, to serve for irrigation, and the
rivers were dry for more than six months of the year. At the period of my
visit, their waters, no longer employed, flowed freely."
Boussingault proceeds to state that two lakes near Ubate in New
Granada, at an elevation of 2,562 mètres (= 8,500 English feet), where there
is a constant temperature of 14° to 16° centigrade [= 57°, 61° Fahrenheit],
had formed but one, a century before his visit; that the waters were
Page 144
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 Fuquené, 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, timber
was abundant, and the neighboring mountains were covered, to a certain
height, with American oaks, laurels, and other trees of indigenous species;
but at the time of his visit the mountains had been almost entirely stripped
of their wood, chiefly to furnish fuel for salt-works. 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 maintains that the lakes of Switzerland have
sustained a depression of level since the too prevalent destruction of the
woods, and 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 the ground." 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
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 Fuquené, 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, timber
was abundant, and the neighboring mountains were covered, to a certain
height, with American oaks, laurels, and other trees of indigenous species;
but at the time of his visit the mountains had been almost entirely stripped
of their wood, chiefly to furnish fuel for salt-works. 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 maintains that the lakes of Switzerland have
sustained a depression of level since the too prevalent destruction of the
woods, and 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 the ground." 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
Page 145
natural reservoirs which springs once filled. There is, however, no want of
positive evidence on this subject.
Marschand cites the following instances: "Before the felling of the
woods, within the last few years, in the valley of the Soulce, the Combe-ès-
Mounin and the Little Valley, the Sorne furnished a regular and sufficient
supply of water for the iron works 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.
"When the factory of St. Ursanne was established, the river that
furnished its power was abundant, long known and tried, and had, from
time immemorial, sufficed for the machinery of a previous factory.
Afterward, 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 spite of the severest droughts, to supply all the fountains of the
town; but, as soon as considerable forests were felled in Combe-de-pré
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 Rongeoles.
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 forests grounds were brought under
cultivation.
positive evidence on this subject.
Marschand cites the following instances: "Before the felling of the
woods, within the last few years, in the valley of the Soulce, the Combe-ès-
Mounin and the Little Valley, the Sorne furnished a regular and sufficient
supply of water for the iron works 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.
"When the factory of St. Ursanne was established, the river that
furnished its power was abundant, long known and tried, and had, from
time immemorial, sufficed for the machinery of a previous factory.
Afterward, 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 spite of the severest droughts, to supply all the fountains of the
town; but, as soon as considerable forests were felled in Combe-de-pré
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 Rongeoles.
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 forests grounds were brought under
cultivation.
Page 146
"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
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."[197]
"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 now more and more
freely, and at length bubble up again in all their original abundance."[198]
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 which 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 become drier,
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
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."[197]
"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 now more and more
freely, and at length bubble up again in all their original abundance."[198]
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 which 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 become drier,
Page 147
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
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."[199]
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 Labruguière, 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 the northern slope of the
Black Mountains. The soil is granitic, the maximum altitude 1,243 mètres
[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 Labruguière 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, brought down a great quantity of pebbles
which still clog the current of the Caunan. The violence of the floods was
sometimes such that they were obliged to stop the machinery for some time.
During the summer another inconvenience was felt. If the dry weather
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
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."[199]
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 Labruguière, 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 the northern slope of the
Black Mountains. The soil is granitic, the maximum altitude 1,243 mètres
[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 Labruguière 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, brought down a great quantity of pebbles
which still clog the current of the Caunan. The violence of the floods was
sometimes such that they were obliged to stop the machinery for some time.
During the summer another inconvenience was felt. If the dry weather
Page 148
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, there are, no
longer, sudden and violent floods which make it necessary to stop the
machinery. 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
stampers 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."
The Forest in Winter.
To estimate rightly the importance of the forest 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 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
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, there are, no
longer, sudden and violent floods which make it necessary to stop the
machinery. 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
stampers 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."
The Forest in Winter.
To estimate rightly the importance of the forest 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 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
Page 149
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, 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 forest upon the waters of the earth has been more
studied in France than in any other part of the civilized world, because that
country has, in recent times, suffered most severely from the destruction of
the woods. But in the southern provinces of that empire, where the evils
resulting from this cause are most sensibly felt, the winters are not attended
with much frost, while, in Northern Europe, where the winters are rigorous
enough to freeze the ground to the depth of some inches, or even feet, a
humid atmosphere and frequent summer rains prevent the drying up of the
springs observed in southern latitudes when the woods are gone. For these
reasons, the specific character of the forest, as a winter reservoir of
moisture in countries with a cold and dry atmosphere, has not attracted so
much attention in France and Northern Europe as it deserves in the United
States, where an excessive climate renders that function of the woods more
important.
In New England, irregular as the climate is, the first autumnal snows
usually fall before the ground is frozen at all, or when the frost extends at
most to the depth of only a few inches. In the woods, especially those
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, if one
has been formed, is soon thawed, and does not again fall below the freezing
point during the winter.
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, 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 forest upon the waters of the earth has been more
studied in France than in any other part of the civilized world, because that
country has, in recent times, suffered most severely from the destruction of
the woods. But in the southern provinces of that empire, where the evils
resulting from this cause are most sensibly felt, the winters are not attended
with much frost, while, in Northern Europe, where the winters are rigorous
enough to freeze the ground to the depth of some inches, or even feet, a
humid atmosphere and frequent summer rains prevent the drying up of the
springs observed in southern latitudes when the woods are gone. For these
reasons, the specific character of the forest, as a winter reservoir of
moisture in countries with a cold and dry atmosphere, has not attracted so
much attention in France and Northern Europe as it deserves in the United
States, where an excessive climate renders that function of the woods more
important.
In New England, irregular as the climate is, the first autumnal snows
usually fall before the ground is frozen at all, or when the frost extends at
most to the depth of only a few inches. In the woods, especially those
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, if one
has been formed, is soon thawed, and does not again fall below the freezing
point during the winter.
Page 150
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 returned to the atmosphere by
direct evaporation, but in the woods it is partially protected from the action
of the sun, and as very little water runs off in the winter by superficial
watercourses, except in rare cases of sudden thaw, 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 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 such situations. In the Northeastern
border States of the American Union, the ground in the deep woods is
covered with snow four or five months, and the proportion of water which
falls in snow does not exceed one fifth of the total precipitation for the year.
[200]
Although, in the open grounds, snow and ice are evaporated with great
rapidity in clear weather, even when the thermometer stands far below the
freezing point, the surface of the snow in the woods does not indicate much
loss in this way. Very small deposits of snowflakes remain unevaporated in
the forest, for many days after snow let fall 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 leaves, 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 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.
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 returned to the atmosphere by
direct evaporation, but in the woods it is partially protected from the action
of the sun, and as very little water runs off in the winter by superficial
watercourses, except in rare cases of sudden thaw, 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 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 such situations. In the Northeastern
border States of the American Union, the ground in the deep woods is
covered with snow four or five months, and the proportion of water which
falls in snow does not exceed one fifth of the total precipitation for the year.
[200]
Although, in the open grounds, snow and ice are evaporated with great
rapidity in clear weather, even when the thermometer stands far below the
freezing point, the surface of the snow in the woods does not indicate much
loss in this way. Very small deposits of snowflakes remain unevaporated in
the forest, for many days after snow let fall 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 leaves, 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 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.
Page 151
"Equal quantities of snow were placed in vessels of the same kind 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."[201]
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. Little of the winter precipitation, therefore, is lost by evaporation, and
as it slowly melts at bottom it is absorbed by the earth, and but a very small
quantity of water runs off from the surface. 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 strata, is evaporated from them
without sinking deep enough to reach wells and springs, which, of course,
depend very 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 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 one of those compensations in which her empire is so rich,
clothed the hillsides with umbrella pines, ilexes, cork oaks, 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 of 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
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."[201]
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. Little of the winter precipitation, therefore, is lost by evaporation, and
as it slowly melts at bottom it is absorbed by the earth, and but a very small
quantity of water runs off from the surface. 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 strata, is evaporated from them
without sinking deep enough to reach wells and springs, which, of course,
depend very 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 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 one of those compensations in which her empire is so rich,
clothed the hillsides with umbrella pines, ilexes, cork oaks, 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 of 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
Page 152
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 saturation through almost the whole year. The rivers
fed by springs and shaded by woods are comparatively uniform in volume,
in temperature, and in chemical composition. 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.[202]
In this state of things, destructive tendencies of all sorts are arrested or
compensated, and tree, bird, beast, and fish, 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.
With the disappearance 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 regular
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 seaward, 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.
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 saturation through almost the whole year. The rivers
fed by springs and shaded by woods are comparatively uniform in volume,
in temperature, and in chemical composition. 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.[202]
In this state of things, destructive tendencies of all sorts are arrested or
compensated, and tree, bird, beast, and fish, 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.
With the disappearance 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 regular
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 seaward, 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.
Page 153
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 watercourses 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 sandbars. 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
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.[203]
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.
In the vast farrago of crudities which the elder Pliny's ambition of
encyclopædic attainment and his ready credulity have gathered together, we
meet some judicious observations. Among these we must reckon the remark
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 watercourses 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 sandbars. 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
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.[203]
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.
In the vast farrago of crudities which the elder Pliny's ambition of
encyclopædic attainment and his ready credulity have gathered together, we
meet some judicious observations. Among these we must reckon the remark
Page 154
with which he accompanies his extraordinary statement respecting the
prevention of springs by the growth of forest trees, though, as is usual with
him, his philosophy is wrong. "Destructive torrents are generally formed
when hills are stripped of the trees which formerly confined and absorbed
the rains." The absorption here referred to is not that of the soil, but of the
roots, which, Pliny supposed, drank up the water to feed the growth of the
trees.
Although this particular evil effect of too extensive clearing was so
early noticed, the lesson seems to have been soon forgotten. The legislation
of the Middle Ages in Europe is full of absurd provisions concerning the
forests, which sovereigns sometimes destroyed because they furnished a
retreat for rebels and robbers, sometimes protected because they were
necessary to breed stags and boars for the chase, and sometimes spared with
the more enlightened view of securing a supply of timber and of fuel to
future generations.[204] It was reserved to later ages to appreciate their
geographical importance, and it is only in very recent times, only in a few
European countries, that the too general felling of the woods has been
recognized as the most destructive among the many causes of the physical
deterioration of the earth.
Condition of the Forest, and its Literature in different
Countries.
The literature of the forest, which in England and America has not yet
become sufficiently extensive to be known as a special branch of
authorship, counts its thousands of volumes in Germany, Italy, and France.
It is in the latter country, perhaps, that the relations of the woods to the
regular drainage of the soil, and especially to the permanence of the natural
configuration of terrestrial surface, have been most thoroughly investigated.
On the other hand, the purely economical aspects of sylviculture have been
most satisfactorily expounded, and that art has been most philosophically
discussed, and most skilfully and successfully practised, in Germany.
The eminence of Italian theoretical hydrographers and the great ability
of Italian hydraulic engineers are well known, but the specific geographical
importance of the woods has not been so clearly recognized in Italy as in
prevention of springs by the growth of forest trees, though, as is usual with
him, his philosophy is wrong. "Destructive torrents are generally formed
when hills are stripped of the trees which formerly confined and absorbed
the rains." The absorption here referred to is not that of the soil, but of the
roots, which, Pliny supposed, drank up the water to feed the growth of the
trees.
Although this particular evil effect of too extensive clearing was so
early noticed, the lesson seems to have been soon forgotten. The legislation
of the Middle Ages in Europe is full of absurd provisions concerning the
forests, which sovereigns sometimes destroyed because they furnished a
retreat for rebels and robbers, sometimes protected because they were
necessary to breed stags and boars for the chase, and sometimes spared with
the more enlightened view of securing a supply of timber and of fuel to
future generations.[204] It was reserved to later ages to appreciate their
geographical importance, and it is only in very recent times, only in a few
European countries, that the too general felling of the woods has been
recognized as the most destructive among the many causes of the physical
deterioration of the earth.
Condition of the Forest, and its Literature in different
Countries.
The literature of the forest, which in England and America has not yet
become sufficiently extensive to be known as a special branch of
authorship, counts its thousands of volumes in Germany, Italy, and France.
It is in the latter country, perhaps, that the relations of the woods to the
regular drainage of the soil, and especially to the permanence of the natural
configuration of terrestrial surface, have been most thoroughly investigated.
On the other hand, the purely economical aspects of sylviculture have been
most satisfactorily expounded, and that art has been most philosophically
discussed, and most skilfully and successfully practised, in Germany.
The eminence of Italian theoretical hydrographers and the great ability
of Italian hydraulic engineers are well known, but the specific geographical
importance of the woods has not been so clearly recognized in Italy as in
Page 155
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 as wide and as hopeless devastation in that country as in
France; but in the French Empire the desolation produced by clearing the
forests is more recent,[205] has been more suddenly effected, 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,[206] 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
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 unexhausted resources of that
fairest of lands, and even for the permanent maintenance of the present
condition of its physical geography.
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. The Eastern Alps, the Western Apennines, and the
has been as completely revolutionized by man, and that the action of
torrents has created as wide and as hopeless devastation in that country as in
France; but in the French Empire the desolation produced by clearing the
forests is more recent,[205] has been more suddenly effected, 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,[206] 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
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 unexhausted resources of that
fairest of lands, and even for the permanent maintenance of the present
condition of its physical geography.
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. The Eastern Alps, the Western Apennines, and the
Page 156
Maritime Alps retained their forests much later; but even here the want of
wood, and the injury to the plains and the navigation of the rivers by
sediment brought down by the torrents, led to some legislation for the
protection of the forests, by the Republic of Venice in the fifteenth century,
by that of Genoa as early at least as the seventeenth; and Marschand states
that the latter Government passed laws requiring the proprietors of
mountain lands to replant the woods. These, however, do not seem to have
been effectually enforced. 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 a century.[207] 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.[208] 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. It has even been calculated that
four tenths of the area of the Ligurian provinces have been washed away or
rendered incapable of cultivation by the felling of the woods.[209]
The damp and cold climate of England requires the maintenance of
household fires through a large part of the year. Contrivances for
economizing fuel were of later introduction in that country than on the
Continent. The soil, like the sky, was, in general, charged with humidity; its
natural condition was unfavorable for 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
wood, and the injury to the plains and the navigation of the rivers by
sediment brought down by the torrents, led to some legislation for the
protection of the forests, by the Republic of Venice in the fifteenth century,
by that of Genoa as early at least as the seventeenth; and Marschand states
that the latter Government passed laws requiring the proprietors of
mountain lands to replant the woods. These, however, do not seem to have
been effectually enforced. 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 a century.[207] 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.[208] 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. It has even been calculated that
four tenths of the area of the Ligurian provinces have been washed away or
rendered incapable of cultivation by the felling of the woods.[209]
The damp and cold climate of England requires the maintenance of
household fires through a large part of the year. Contrivances for
economizing fuel were of later introduction in that country than on the
Continent. The soil, like the sky, was, in general, charged with humidity; its
natural condition was unfavorable for 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
Page 157
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, réed, rush, and also seacole, will be good merchandize euen in the
citie of London, whereunto some of them euen now haue gotten readie
passage, and taken vp their innes in the greatest merchants' parlours. * * * I
would wish that I might liue no longer than to sée 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 frée deed, copie hold, or fee
farme, might plant one acre of wood, or sowe the same with oke mast,
hasell, béech, 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."[210] 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
recently, been better understood than sylviculture, the sowing and training
of the forest. But this latter branch of rural improvement is now pursued on
a very considerable scale, though, so far as I know, not by the National
Government.
The Influence of the Forest on Inundations.
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 French foresters and public economists has been specially
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, réed, rush, and also seacole, will be good merchandize euen in the
citie of London, whereunto some of them euen now haue gotten readie
passage, and taken vp their innes in the greatest merchants' parlours. * * * I
would wish that I might liue no longer than to sée 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 frée deed, copie hold, or fee
farme, might plant one acre of wood, or sowe the same with oke mast,
hasell, béech, 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."[210] 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
recently, been better understood than sylviculture, the sowing and training
of the forest. But this latter branch of rural improvement is now pursued on
a very considerable scale, though, so far as I know, not by the National
Government.
The Influence of the Forest on Inundations.
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 French foresters and public economists has been specially
Page 158
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
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 mechanical resistance, too, offered by the trunks of trees
and of undergrowth to the flow of water over the surface, tends sensibly to
retard the rapidity of its descent down declivities, and to divert and divide
streams which may have already accumulated from smaller threads of
water.[211]
Inundations are produced by the insufficiency of the natural channels of
rivers to carry off the waters of their basins as fast as those waters flow into
them. 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
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
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 mechanical resistance, too, offered by the trunks of trees
and of undergrowth to the flow of water over the surface, tends sensibly to
retard the rapidity of its descent down declivities, and to divert and divide
streams which may have already accumulated from smaller threads of
water.[211]
Inundations are produced by the insufficiency of the natural channels of
rivers to carry off the waters of their basins as fast as those waters flow into
them. 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
Page 159
suddenly before man had removed the natural checks to the too rapid
drainage of the basins in which their tributaries originate. The banks of the
rivers and smaller streams in the North American colonies were formerly
little abraded by the currents. 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. A circumstance almost conclusive as to the regularity of
flow in forest rivers, is that they do not 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.
In the Northern United States, although inundations are sometimes
produced in the height of summer by heavy rains, 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 produced 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 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 snowstorms 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 leaves the ridges
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
drainage of the basins in which their tributaries originate. The banks of the
rivers and smaller streams in the North American colonies were formerly
little abraded by the currents. 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. A circumstance almost conclusive as to the regularity of
flow in forest rivers, is that they do not 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.
In the Northern United States, although inundations are sometimes
produced in the height of summer by heavy rains, 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 produced 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 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 snowstorms 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 leaves the ridges
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
Page 160
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 the 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 the sandy ploughed fields, in all
large agricultural districts, and hence, even if, in the case we are supposing,
the open ground chance to have been 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 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.
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 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.
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 the 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 the sandy ploughed fields, in all
large agricultural districts, and hence, even if, in the case we are supposing,
the open ground chance to have been 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 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.
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 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 161
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.
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 Belgrand and his commentator Vallès 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 is
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
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.
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 Belgrand and his commentator Vallès 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 is
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
Page 162
passage of water through channels which nature has provided for its descent
to lower strata.
As to the first of these, we may appeal to familiar facts within the
personal knowledge of every man acquainted with the operations of sylvan
nature. I have before me a letter from an acute and experienced observer,
containing this paragraph: "I think that rain water does not ever, except in
very trifling quantities, flow over the leaves in the woods in summer or
autumn. Water runs over them only in the spring, when they are pressed
down smoothly and compactly, 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, I believe 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 downward,[212] but their
swelling growth powerfully tends to enlarge 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 Vallès, though their
conclusions have not been accepted by many, are very important in one
point of view. These 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 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
to lower strata.
As to the first of these, we may appeal to familiar facts within the
personal knowledge of every man acquainted with the operations of sylvan
nature. I have before me a letter from an acute and experienced observer,
containing this paragraph: "I think that rain water does not ever, except in
very trifling quantities, flow over the leaves in the woods in summer or
autumn. Water runs over them only in the spring, when they are pressed
down smoothly and compactly, 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, I believe 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 downward,[212] but their
swelling growth powerfully tends to enlarge 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 Vallès, though their
conclusions have not been accepted by many, are very important in one
point of view. These 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 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
Page 163
and always giving it off, not by evaporation only, but by infiltration and
percolation.
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.[213] 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.
But the great, the irreparable, the appalling mischiefs which have
already resulted, and threaten to ensue on a still more extensive scale
hereafter, from too rapid superficial drainage, are of a properly geographical
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 framework 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 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
percolation.
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.[213] 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.
But the great, the irreparable, the appalling mischiefs which have
already resulted, and threaten to ensue on a still more extensive scale
hereafter, from too rapid superficial drainage, are of a properly geographical
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 framework 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 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
Page 164
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 traversing such scenes, it is difficult to resist the
impression that nature pronounced the curse of perpetual sterility and
desolation upon these sublime but fearful wastes, difficult to believe that
they were 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.
It is certain 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 vain to expect that 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
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 traversing such scenes, it is difficult to resist the
impression that nature pronounced the curse of perpetual sterility and
desolation upon these sublime but fearful wastes, difficult to believe that
they were 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.
It is certain 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 vain to expect that 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
Page 165
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.[214] 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. Something
may be done by exempting standing forests from taxation, and by imposing
taxes on wood felled for fuel or for timber, something by premiums or
honorary distinctions for judicious management of the woods. It would 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.
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 productive of little
advantage to the public interests, and have very generally gone to decay.
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.[215]
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
indiscriminate clearing of the woods may expose not only future
generations, but the very soil itself. Fortunately, 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 northeastern counties, a vast extent of territory in
which the lumberman has only here and there established his camp, and
serious fears are entertained, not only of the depopulation of those districts,
but of enormous mischiefs to the provinces contiguous to them.[214] 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. Something
may be done by exempting standing forests from taxation, and by imposing
taxes on wood felled for fuel or for timber, something by premiums or
honorary distinctions for judicious management of the woods. It would 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.
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 productive of little
advantage to the public interests, and have very generally gone to decay.
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.[215]
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
indiscriminate clearing of the woods may expose not only future
generations, but the very soil itself. Fortunately, 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 northeastern counties, a vast extent of territory in
which the lumberman has only here and there established his camp, and
Page 166
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
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 far more intense, the short heats of
summer not less fierce 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
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
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 far more intense, the short heats of
summer not less fierce 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
Page 167
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 much 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 serious injury to the
commerce of the 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.
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 southeastern 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.[216]
The provinces of Dauphiny, Avignon, and Provence comprise a territory
of fourteen or fifteen thousand square miles, bounded northwest by the
Isere, northeast and east by the Alps, south by the Mediterranean, west by
the Rhone, and extending from 42° to about 45° of north latitude. The
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 much 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 serious injury to the
commerce of the 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.
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 southeastern 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.[216]
The provinces of Dauphiny, Avignon, and Provence comprise a territory
of fourteen or fifteen thousand square miles, bounded northwest by the
Isere, northeast and east by the Alps, south by the Mediterranean, west by
the Rhone, and extending from 42° to about 45° of north latitude. The
Page 168
surface is generally hilly and even mountainous, and several of the peaks in
Dauphiny rise above the limit of perpetual snow. The climate, as compared
with that of the United States in the same latitude, is extremely mild. Little
snow falls, except upon the higher mountain ranges, 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 43½°, and upon the coast, grow the orange, the
lemon, and the date palm. 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.[217] 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.
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
Dauphiny rise above the limit of perpetual snow. The climate, as compared
with that of the United States in the same latitude, is extremely mild. Little
snow falls, except upon the higher mountain ranges, 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 43½°, and upon the coast, grow the orange, the
lemon, and the date palm. 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.[217] 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.
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
Page 169
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.
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, and I add further details from the same source.
"Commune of Barles, 1707: Two hills have become connected by land
slides, and have formed a lake which covers the best part of the soil. 1746:
New slides buried twenty houses composing a village, no trace of which is
left; more than one third of the land had disappeared.
"Monans, 1724: Deserted by its inhabitants and no longer cultivated.
"Gueydan, 1760: It appears by records that the best grounds have been
swept off since 1756, and that ravines occupy their place.
"Digne, 1762: The river Bléone has destroyed the most valuable part of
the territory.
"Malmaison, 1768: The inhabitants have emigrated, all their fields
having been lost."
In the case of the commune of St. Laurent du Var, it appears that, after
clearings in the Alps, succeeded by others in the common woods of the
town, the floods of the torrent Var became more formidable, and had
already carried off much land as early as 1708. "The clearing continued,
and more soil was swept away in 1761. In 1762, after another destructive
inundation, many of the inhabitants emigrated, and in 1765, one half of the
territory had been laid waste.
"In 1766, the assessor Serraire said to the Assembly: 'As to the damage
caused by brooks and torrents, it is impossible to deny its extent. Upper
Provence is in danger of total destruction, and the waters which lay it waste
threaten also the ruin of the most valuable grounds on the plain below.
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.
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, and I add further details from the same source.
"Commune of Barles, 1707: Two hills have become connected by land
slides, and have formed a lake which covers the best part of the soil. 1746:
New slides buried twenty houses composing a village, no trace of which is
left; more than one third of the land had disappeared.
"Monans, 1724: Deserted by its inhabitants and no longer cultivated.
"Gueydan, 1760: It appears by records that the best grounds have been
swept off since 1756, and that ravines occupy their place.
"Digne, 1762: The river Bléone has destroyed the most valuable part of
the territory.
"Malmaison, 1768: The inhabitants have emigrated, all their fields
having been lost."
In the case of the commune of St. Laurent du Var, it appears that, after
clearings in the Alps, succeeded by others in the common woods of the
town, the floods of the torrent Var became more formidable, and had
already carried off much land as early as 1708. "The clearing continued,
and more soil was swept away in 1761. In 1762, after another destructive
inundation, many of the inhabitants emigrated, and in 1765, one half of the
territory had been laid waste.
"In 1766, the assessor Serraire said to the Assembly: 'As to the damage
caused by brooks and torrents, it is impossible to deny its extent. Upper
Provence is in danger of total destruction, and the waters which lay it waste
threaten also the ruin of the most valuable grounds on the plain below.
Page 170
Villages have been almost submerged by torrents which formerly had not
even names, and large towns are on the point of destruction from the same
cause.'"
In 1776, Viscount Puget thus reported: "The mere aspect of Upper
Provence is calculated to appal the patriotic magistrate. One sees only lofty
mountains, deep valleys with precipitous sides, rivers with broad beds and
little water, impetuous torrents, which in floods lay waste the cultivated
land upon their banks and roll huge rocks along their channels; steep and
parched hillsides, the melancholy consequences of indiscriminate clearing;
villages whose inhabitants, finding no longer the means of subsistence, are
emigrating day by day; houses dilapidated to huts, and but a miserable
remnant of population."
"In a document of the year 1771, the ravages of the torrents were
compared to the effects of an earthquake, half the soil in many communes
seeming to have been swallowed up.
"Our mountains," said the administrators of the province of the Lower
Alps in 1792, "present nothing but a surface of stony tufa; clearing is still
going on, and the little rivulets are becoming torrents. Many communes
have lost their harvests, their flocks, and their houses by floods. The
washing down of the mountains is to be ascribed to the clearings and the
practice of burning them over."
These complaints, it will be seen, all date before the Revolution, but the
desolation they describe has since advanced with still swifter steps.
Surell—whose valuable work, Étude sur les Torrents des Hautes Alpes,
published in 1841, presents the 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 Dévoluy,
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 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
even names, and large towns are on the point of destruction from the same
cause.'"
In 1776, Viscount Puget thus reported: "The mere aspect of Upper
Provence is calculated to appal the patriotic magistrate. One sees only lofty
mountains, deep valleys with precipitous sides, rivers with broad beds and
little water, impetuous torrents, which in floods lay waste the cultivated
land upon their banks and roll huge rocks along their channels; steep and
parched hillsides, the melancholy consequences of indiscriminate clearing;
villages whose inhabitants, finding no longer the means of subsistence, are
emigrating day by day; houses dilapidated to huts, and but a miserable
remnant of population."
"In a document of the year 1771, the ravages of the torrents were
compared to the effects of an earthquake, half the soil in many communes
seeming to have been swallowed up.
"Our mountains," said the administrators of the province of the Lower
Alps in 1792, "present nothing but a surface of stony tufa; clearing is still
going on, and the little rivulets are becoming torrents. Many communes
have lost their harvests, their flocks, and their houses by floods. The
washing down of the mountains is to be ascribed to the clearings and the
practice of burning them over."
These complaints, it will be seen, all date before the Revolution, but the
desolation they describe has since advanced with still swifter steps.
Surell—whose valuable work, Étude sur les Torrents des Hautes Alpes,
published in 1841, presents the 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 Dévoluy,
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 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
Page 171
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
Agnères. 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 watercourse. "Every storm," says Surell, page 153,
"gives rise to a new torrent. 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."
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
Agnères. 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 watercourse. "Every storm," says Surell, page 153,
"gives rise to a new torrent. 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 172
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 three kilomètres [= one mile and seven eighths English], 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 Briançon 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 cowdung, and even this
they can afford to do but once a year. This bread becomes so hard that it can
be cut only with an axe, and I have myself seen a loaf of bread in
September, at the kneading of which I was present the January previous.
"Whoever has visited the valley of Barcelonette, those of Embrun, and
of Verdun, and that Arabia Petræa of the department of the Upper Alps,
called Dévoluy, knows that there is no time to lose, that in fifty years from
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 three kilomètres [= one mile and seven eighths English], 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 Briançon 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 cowdung, and even this
they can afford to do but once a year. This bread becomes so hard that it can
be cut only with an axe, and I have myself seen a loaf of bread in
September, at the kneading of which I was present the January previous.
"Whoever has visited the valley of Barcelonette, those of Embrun, and
of Verdun, and that Arabia Petræa of the department of the Upper Alps,
called Dévoluy, knows that there is no time to lose, that in fifty years from
Page 173
this date France will be separated from Savoy, as Egypt from Syria, by a
desert."[218]
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."[219] 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
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
excursion 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
desert."[218]
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."[219] 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
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
excursion 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
Page 174
cohesion, it rolls down to the valleys, sometimes in floods resembling
black, yellow, or reddish lava, sometimes in streams of pebbles, and even
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. These gorges, under the influence of the sun which cracks and shivers
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
toward 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 which
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
forward 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.
"This is but an imperfect sketch of this scourge of the Alps. Its
devastations are increasing with the progress of clearing, and are every day
black, yellow, or reddish lava, sometimes in streams of pebbles, and even
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. These gorges, under the influence of the sun which cracks and shivers
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
toward 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 which
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
forward 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.
"This is but an imperfect sketch of this scourge of the Alps. Its
devastations are increasing with the progress of clearing, and are every day
Page 175
turning a portion of our frontier departments into barren wastes.
"The unfortunate passion for clearing manifested itself at the beginning
of the French Revolution, and has much increased under the pressure of
immediate want. It has now reached an extreme point, and must be speedily
checked, or the last inhabitant will be compelled to retreat when the last tree
falls.
"The elements of destruction are increasing in violence. Rivers might be
mentioned whose beds have been raised ten feet in a single year. 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, scratch the ground in search of roots to
satisfy their hunger, is periodically washed and carried off by melting
snows and summer storms.
"The unfortunate passion for clearing manifested itself at the beginning
of the French Revolution, and has much increased under the pressure of
immediate want. It has now reached an extreme point, and must be speedily
checked, or the last inhabitant will be compelled to retreat when the last tree
falls.
"The elements of destruction are increasing in violence. Rivers might be
mentioned whose beds have been raised ten feet in a single year. 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, scratch the ground in search of roots to
satisfy their hunger, is periodically washed and carried off by melting
snows and summer storms.
Page 176
"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 2,000 mètres [about
6,600 feet, or a mile and a quarter] in width, and, at ordinary times, has a
current of water less than 10 mètres [about 33 feet] wide, shows something
of the extent of the damage.[220] 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 acres
devoted to agriculture; every year will aggravate the evil, and, in a half
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 Isère, the Drome, Ariège, the Upper and the Lower
Pyrenees, the Lozère, the Ardennes, the 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.[221]
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 2,000 mètres [about
6,600 feet, or a mile and a quarter] in width, and, at ordinary times, has a
current of water less than 10 mètres [about 33 feet] wide, shows something
of the extent of the damage.[220] 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 acres
devoted to agriculture; every year will aggravate the evil, and, in a half
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 Isère, the Drome, Ariège, the Upper and the Lower
Pyrenees, the Lozère, the Ardennes, the 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.[221]
Page 177
Highly colored as these pictures seem, they are not exaggerated,
although the hasty tourist through Southern France 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.[222]
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.[223]
The traveller who visits the depths of an Alpine ravine, observes the
length and width of the gorge and 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 compute 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
although the hasty tourist through Southern France 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.[222]
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.[223]
The traveller who visits the depths of an Alpine ravine, observes the
length and width of the gorge and 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 compute 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
Page 178
masses of gravel and of rock.[224] The simple measurement of the cubical
contents of the semi-circular 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.
It must further be remembered, that every inch of the violent movement
of the rocks is accompanied with crushing concussion, or, at least, with
great abrasion, and, as you follow the deposit 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, sand,
impalpable slime.
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. All 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.[225]
In these valleys of ancient formation, which extend into the very heart
of the mountains, the streams, though rapid, have 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.
Transporting Power of Rivers.
contents of the semi-circular 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.
It must further be remembered, that every inch of the violent movement
of the rocks is accompanied with crushing concussion, or, at least, with
great abrasion, and, as you follow the deposit 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, sand,
impalpable slime.
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. All 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.[225]
In these valleys of ancient formation, which extend into the very heart
of the mountains, the streams, though rapid, have 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.
Transporting Power of Rivers.
Page 179
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
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
milldam 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 slack water 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 deposited, carried it to ponds and still-water reaches
below, and left the bed of the river almost precisely in its former condition,
though, of course, with the slight 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 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
show something of the eroding and transporting power of streams which, in
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
milldam 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 slack water 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 deposited, carried it to ponds and still-water reaches
below, and left the bed of the river almost precisely in its former condition,
though, of course, with the slight 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 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
Page 180
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.
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
that purpose until near Piacenza, 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.[226] 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 from six to fifteen feet above the general level of its banks, 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.[227]
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
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.
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
that purpose until near Piacenza, 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.[226] 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 from six to fifteen feet above the general level of its banks, 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.[227]
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
Page 181
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
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 a seaport in the time of Augustus. The combined action of the
two rivers has so advanced the coast line that Adria is now about 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.[228] 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 mètres, 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.[229] The depth of the annual deposit is stated at
eighteen centimètres, 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
ravines in the Alps and Apennines, change the plan and profile of their
chains, and give their southern and northern faces respectively a
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 a seaport in the time of Augustus. The combined action of the
two rivers has so advanced the coast line that Adria is now about 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.[228] 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 mètres, 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.[229] The depth of the annual deposit is stated at
eighteen centimètres, 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
Page 182
watershed not less than one hundred and fifty miles—is arrested by the still
waters of the Lakes Maggiore and Como, and some smaller lacustrine
reservoirs, and never reaches the sea. The Po is not continuously embanked
except for the lower half of its course. Above Piacenza, 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.
If we add to the estimated annual deposits of the Po at its mouth, 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
Maggiore by the Tosa, the Maggia, and the Ticino, into the lake of Como by
the Maira and the Adda, into the lake of Garda by its affluents, 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 four times the quantity carried to the Adriatic by
the Po, or 220,000,000 cubic yards of solid matter, abstracted every year
from the Italian Alps and the Apennines, and removed out of their domain
by the force of running water.[230]
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.[231] 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
waters of the Lakes Maggiore and Como, and some smaller lacustrine
reservoirs, and never reaches the sea. The Po is not continuously embanked
except for the lower half of its course. Above Piacenza, 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.
If we add to the estimated annual deposits of the Po at its mouth, 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
Maggiore by the Tosa, the Maggia, and the Ticino, into the lake of Como by
the Maira and the Adda, into the lake of Garda by its affluents, 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 four times the quantity carried to the Adriatic by
the Po, or 220,000,000 cubic yards of solid matter, abstracted every year
from the Italian Alps and the Apennines, and removed out of their domain
by the force of running water.[230]
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.[231] 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
Page 183
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
before the year 1200, epochs when the erosion and transportation of solid
matter from the Alps and the Apennines were 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 northeastern declivities of the
Apennines—have annually sent down into the Adriatic, the lakes, and the
plains, not less than 150,000,000 cubic yards of earth and disintegrated
rock. We have, then, an aggregate of 300,000,000,000 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 six
yards.[232] 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
the west.[233]
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.
the Middle Ages, and, of course, there must have been, at different periods
before the year 1200, epochs when the erosion and transportation of solid
matter from the Alps and the Apennines were 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 northeastern declivities of the
Apennines—have annually sent down into the Adriatic, the lakes, and the
plains, not less than 150,000,000 cubic yards of earth and disintegrated
rock. We have, then, an aggregate of 300,000,000,000 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 six
yards.[232] 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
the west.[233]
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.
Page 184
We cannot measure the share which human action has had in
augmenting the intensity of causes of mountain degradation, 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. Now 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.
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,
gradually raised them above the surface, and finally expanded them into
broad plains traversed by gently flowing streams. If we could go 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.
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
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
augmenting the intensity of causes of mountain degradation, 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. Now 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.
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,
gradually raised them above the surface, and finally expanded them into
broad plains traversed by gently flowing streams. If we could go 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.
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
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
Page 185
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 Surell, "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."[234]
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
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;[235] 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.
Mountain Slides.
I have said that the mountainous regions of the Atlantic States of the
American Union are exposed to similar ravages, and I may add that there is,
in some cases, reason to apprehend from the same cause even more
appalling calamities 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 buttresses that supported the sloping strata above.
furious torrent now sinks to the rank of a humble and harmless brooklet. "In
traversing this department," says Surell, "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."[234]
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
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;[235] 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.
Mountain Slides.
I have said that the mountainous regions of the Atlantic States of the
American Union are exposed to similar ravages, and I may add that there is,
in some cases, reason to apprehend from the same cause even more
appalling calamities 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 buttresses that supported the sloping strata above.
Page 186
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.[236] 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
sand stone, 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.[237] 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
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.[236] 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
sand stone, 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.[237] 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
Page 187
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 Goldau in Switzerland, and 450 of its
people, on the 2d of September, 1806, is almost 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.[238]
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.[239]
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.
In nearly every case of this sort the circumstances of which are known,
the immediate cause of the slip has been, either an earthquake, the
imbibition of water in large quantities by bare earth, or its introduction
between or beneath solid strata. If water insinuates itself 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
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 Goldau in Switzerland, and 450 of its
people, on the 2d of September, 1806, is almost 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.[238]
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.[239]
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.
In nearly every case of this sort the circumstances of which are known,
the immediate cause of the slip has been, either an earthquake, the
imbibition of water in large quantities by bare earth, or its introduction
between or beneath solid strata. If water insinuates itself 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
Page 188
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 an unctuous
clay, and inclining rapidly toward 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
original consistence, and become a loose and slippery mass instead of a
cohesive and tenacious bed.
Protection against fall of Rocks and Avalanches by
Trees.
Forests 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
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 an unctuous
clay, and inclining rapidly toward 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
original consistence, and become a loose and slippery mass instead of a
cohesive and tenacious bed.
Protection against fall of Rocks and Avalanches by
Trees.
Forests 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
Page 189
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.[240]
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 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. Marschand states that, the very first winter after the felling of
the trees on the higher part of a declivity between Saanen 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.[241] 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 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.[242]
Principal Causes of the Destruction of the Forest.
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.[240]
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 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. Marschand states that, the very first winter after the felling of
the trees on the higher part of a declivity between Saanen 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.[241] 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 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.[242]
Principal Causes of the Destruction of the Forest.
Page 190
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. With growing numbers, too, come 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 circumstance 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 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 has become a centre for a lumber trade, which, in the bulk of its
material, and, consequently, in the tonnage required for its transportation,
rivals the commerce of the greatest European cities. Immense rafts are
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.[243] 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 vessels as the Thames.[244] Of late, Chicago, in Illinois, has
been one of the greatest lumber as well as grain depots of the United States,
and it receives and distributes contributions from all the forests in the States
washed by Lake Michigan, as well as from some more distant points.
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[245] form openings which let in the wind, and thus sometimes
occasion the overthrow of thousands of trees, the fall of which dams up
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. With growing numbers, too, come 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 circumstance 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 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 has become a centre for a lumber trade, which, in the bulk of its
material, and, consequently, in the tonnage required for its transportation,
rivals the commerce of the greatest European cities. Immense rafts are
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.[243] 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 vessels as the Thames.[244] Of late, Chicago, in Illinois, has
been one of the greatest lumber as well as grain depots of the United States,
and it receives and distributes contributions from all the forests in the States
washed by Lake Michigan, as well as from some more distant points.
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[245] form openings which let in the wind, and thus sometimes
occasion the overthrow of thousands of trees, the fall of which dams up
Page 191
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 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,
indiscriminately, every age and every species of tree.[246] While, then,
without much 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.[247]
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 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.[248] 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, 6feet, 247 feet.
Maple, 5 " 9inches,
Buttonwood, 5 " 6 "
Elm, 5 "
Hemlock, 4 " 9 " — From 100 to 200 feet.
Oak, 4 "
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 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,
indiscriminately, every age and every species of tree.[246] While, then,
without much 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.[247]
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 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.[248] 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, 6feet, 247 feet.
Maple, 5 " 9inches,
Buttonwood, 5 " 6 "
Elm, 5 "
Hemlock, 4 " 9 " — From 100 to 200 feet.
Oak, 4 "
Page 192
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.[249]
These descriptions, it will be noticed, apply to trees cut from sixty to
one hundred 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 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 six, and sometimes even
seven 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
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.[249]
These descriptions, it will be noticed, apply to trees cut from sixty to
one hundred 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 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 six, and sometimes even
seven 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
Page 193
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.[250]
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 intrusted
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
proceeding expose the banks of the rivers employed as channels of flotation
to abrasion,[251] 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.[252]
Special Causes of the Destruction of European Woods.
The causes of forest waste thus far enumerated are more or less
common to both continents; but in Europe extensive woods have, at
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.[250]
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 intrusted
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
proceeding expose the banks of the rivers employed as channels of flotation
to abrasion,[251] 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.[252]
Special Causes of the Destruction of European Woods.
The causes of forest waste thus far enumerated are more or less
common to both continents; but in Europe extensive woods have, at
Page 194
different periods, been deliberately destroyed by fire or the axe, because
they afforded a retreat to enemies, robbers, and outlaws, and this practice is
said to have been resorted to in the Mediterranean provinces of France as
recently as the time of Napoleon I.[253] The severe and even sanguinary
legislation, by which some of the governments of mediæval Europe, as well
as of earlier ages, protected the woods, was dictated by a love of the chase,
or the fear of a scarcity of fuel and timber. The laws of almost every
European state more or less adequately secure the permanence of the forest;
and I believe Spain is the only European land which has not made some
public provision for the protection and restoration of the woods—the only
country whose people systematically war upon the garden of God.[254]
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.[255] 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 mediæval 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,[256] 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."
they afforded a retreat to enemies, robbers, and outlaws, and this practice is
said to have been resorted to in the Mediterranean provinces of France as
recently as the time of Napoleon I.[253] The severe and even sanguinary
legislation, by which some of the governments of mediæval Europe, as well
as of earlier ages, protected the woods, was dictated by a love of the chase,
or the fear of a scarcity of fuel and timber. The laws of almost every
European state more or less adequately secure the permanence of the forest;
and I believe Spain is the only European land which has not made some
public provision for the protection and restoration of the woods—the only
country whose people systematically war upon the garden of God.[254]
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.[255] 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 mediæval 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,[256] 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."
Page 195
These barbarous acts, as Bonnemère observes,[257] 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, "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."[258] 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."[259] 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
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, "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."[258] 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."[259] 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
Page 196
kings to consent to some relaxation of the severity of these latter. Francis I,
however, revived their barbarous provisions, and, according to Bonnemère,
even so good a monarch as Henry IV reënacted 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."[260]
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
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."[261]
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 protected by 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 were no
longer respected.[262] 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 ploughland, its injurious effects 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
however, revived their barbarous provisions, and, according to Bonnemère,
even so good a monarch as Henry IV reënacted 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."[260]
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
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."[261]
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 protected by 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 were no
longer respected.[262] 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 ploughland, its injurious effects 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
Page 197
remaining woods, and a waste was produced which hundreds of years and
millions of treasure will hardly repair.
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.
[263]
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
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 often 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, a tall
herbaceous plant, very seldom seen growing under other circumstances, and
millions of treasure will hardly repair.
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.
[263]
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
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 often 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, a tall
herbaceous plant, very seldom seen growing under other circumstances, and
Page 198
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.
Moritz Wagner, as quoted by Wittwer,[264] 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 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: "In Staffordshire, on the estate of a relation, where I had
ample means of investigation, 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."[265] Had the author
informed us that these twelve plants belonged to a species whose seeds
enter into the nutriment of the birds which appeared with the young wood,
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.
Moritz Wagner, as quoted by Wittwer,[264] 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 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: "In Staffordshire, on the estate of a relation, where I had
ample means of investigation, 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."[265] Had the author
informed us that these twelve plants belonged to a species whose seeds
enter into the nutriment of the birds which appeared with the young wood,
Page 199
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 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?[266]
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
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"—
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 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?[266]
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
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"—
Page 200
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.[267]
Although, as I have said, birds do not frequent the deeper recesses of the
wood,[268] 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
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.
The insects most injurious to rural industry 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 the larvæ.[269] 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.
Utility of the Forest.
In most parts of Europe, the woods are already so nearly extirpated that
the mere protection of those which now exist is by no means an adequate
remedy for the evils resulting from the want of them; and besides, as I have
already said, abundant experience has shown that no legislation can secure
the permanence of the forest in private hands. Enlightened individuals in
most European states, governments in others, have made very extensive
plantations,[270] and France has now set herself energetically at work to
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.[267]
Although, as I have said, birds do not frequent the deeper recesses of the
wood,[268] 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
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.
The insects most injurious to rural industry 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 the larvæ.[269] 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.
Utility of the Forest.
In most parts of Europe, the woods are already so nearly extirpated that
the mere protection of those which now exist is by no means an adequate
remedy for the evils resulting from the want of them; and besides, as I have
already said, abundant experience has shown that no legislation can secure
the permanence of the forest in private hands. Enlightened individuals in
most European states, governments in others, have made very extensive
plantations,[270] and France has now set herself energetically at work to
Page 201
restore the woods in the southern provinces, and thereby to prevent the utter
depopulation and waste with which that once fertile soil and delicious
climate are threatened.
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 planting of the mountains
will diminish the frequency and violence of river inundations, prevent the
formation of torrents, 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,
prevent the spread of miasmatic effluvia, and, finally, furnish an
inexhaustible and self-renewing supply of a material indispensable to so
many purposes of domestic comfort, to the successful exercise of every art
of peace, every destructive energy of war.[271]
But our enumeration of the uses of trees is not yet complete. Besides the
influence of the forest, in mountain ranges, as a means of preventing the
scooping out of ravines and the accumulations of water which fill them,
trees subserve a valuable purpose, in lower positions, as barriers against the
spread of floods and of the material they transport with them; but this will
be more appropriately considered in the chapter on the waters; and another
very important use of trees, that of fixing movable sand-dunes, and
reclaiming them to profitable cultivation, will be pointed out in the chapter
on the sands.
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 greatly augmented
the demand for wood,[272] and, but for improvements in metallurgy which
have facilitated the substitution of iron for that material, the last twenty-five
years would almost have stripped Europe of her only remaining trees fit for
such uses.[273] The walnut trees alone felled in Europe within two years to
furnish the armies of America with gunstocks, would form a forest of no
inconsiderable extent.[274]
The Forests of Europe.
depopulation and waste with which that once fertile soil and delicious
climate are threatened.
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 planting of the mountains
will diminish the frequency and violence of river inundations, prevent the
formation of torrents, 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,
prevent the spread of miasmatic effluvia, and, finally, furnish an
inexhaustible and self-renewing supply of a material indispensable to so
many purposes of domestic comfort, to the successful exercise of every art
of peace, every destructive energy of war.[271]
But our enumeration of the uses of trees is not yet complete. Besides the
influence of the forest, in mountain ranges, as a means of preventing the
scooping out of ravines and the accumulations of water which fill them,
trees subserve a valuable purpose, in lower positions, as barriers against the
spread of floods and of the material they transport with them; but this will
be more appropriately considered in the chapter on the waters; and another
very important use of trees, that of fixing movable sand-dunes, and
reclaiming them to profitable cultivation, will be pointed out in the chapter
on the sands.
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 greatly augmented
the demand for wood,[272] and, but for improvements in metallurgy which
have facilitated the substitution of iron for that material, the last twenty-five
years would almost have stripped Europe of her only remaining trees fit for
such uses.[273] The walnut trees alone felled in Europe within two years to
furnish the armies of America with gunstocks, would form a forest of no
inconsiderable extent.[274]
The Forests of Europe.
Page 202
Mirabeau estimated the forests of France in 1750 at seventeen millions
of hectares [42,000,000 acres]; in 1860 they were reduced to eight millions
[19,769,000 acres]. This would be at the rate of 82,000 hectares [202,600
acres] per year. Troy, from whose valuable pamphlet, Étude 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 Ariège, for instance, clearing has gone on during the
last half century at the rate of three thousand acres a year,[275] and in all
parts of the empire trees have been felled faster than they have grown. The
total area of France, excluding Savoy, is 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.[276] 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
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.[277] 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.
Italy and Spain are bared of trees in a greater degree than France, and
even Russia, which we habitually consider as substantially a forest country,
is beginning to suffer seriously for want of wood. Jourdier, as quoted by
Clavé, 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
of hectares [42,000,000 acres]; in 1860 they were reduced to eight millions
[19,769,000 acres]. This would be at the rate of 82,000 hectares [202,600
acres] per year. Troy, from whose valuable pamphlet, Étude 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 Ariège, for instance, clearing has gone on during the
last half century at the rate of three thousand acres a year,[275] and in all
parts of the empire trees have been felled faster than they have grown. The
total area of France, excluding Savoy, is 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.[276] 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
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.[277] 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.
Italy and Spain are bared of trees in a greater degree than France, and
even Russia, which we habitually consider as substantially a forest country,
is beginning to suffer seriously for want of wood. Jourdier, as quoted by
Clavé, 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
Page 203
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 anthracite, shall diminish its evils."[278]
Germany, from character of surface and climate, and from the attention
which has long been paid in all the German States to sylviculture, is, taken
as a whole, in a far better condition in this respect than its more southern
neighbors; but in the Alpine provinces of Bavaria and Austria, the same
improvidence which marks the rural economy of the corresponding districts
of Switzerland, Italy, and France, is producing effects hardly less disastrous.
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.[279]
Forests of the United States and Canada.
The vast forests of the United States and Canada cannot long resist the
improvident habits of the backwoodsman and the increased demand for
lumber. According to the census of the former country for 1860, which
gives returns of the "sawed and planed lumber" alone, timber for framing
and for a vast variety of mechanical purposes being omitted altogether, the
value of the former material prepared for market in the United States was,
in 1850, $58,521,976; in 1860, $95,912,286. The quantity of unsawed
lumber is not likely to have increased in the same proportion, because
comparatively little is exported in that condition, and because masonry is
fast taking the place of carpentry in building, and stone, brick, and iron are
used instead of timber more largely than they were ten years ago. Still a
much greater quantity of unsawed lumber must have been marketed in 1860
than in 1850. It must further be admitted that the price of lumber rose
considerably between those dates, and consequently that the increase in
quantity is not to be measured by the increase in pecuniary value. Perhaps
this rise of prices may even be sufficient to make the entire difference
between the value of "sawed and planed lumber" produced in the ten years
in question by the six New England States (21 per cent.), and the six Middle
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 anthracite, shall diminish its evils."[278]
Germany, from character of surface and climate, and from the attention
which has long been paid in all the German States to sylviculture, is, taken
as a whole, in a far better condition in this respect than its more southern
neighbors; but in the Alpine provinces of Bavaria and Austria, the same
improvidence which marks the rural economy of the corresponding districts
of Switzerland, Italy, and France, is producing effects hardly less disastrous.
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.[279]
Forests of the United States and Canada.
The vast forests of the United States and Canada cannot long resist the
improvident habits of the backwoodsman and the increased demand for
lumber. According to the census of the former country for 1860, which
gives returns of the "sawed and planed lumber" alone, timber for framing
and for a vast variety of mechanical purposes being omitted altogether, the
value of the former material prepared for market in the United States was,
in 1850, $58,521,976; in 1860, $95,912,286. The quantity of unsawed
lumber is not likely to have increased in the same proportion, because
comparatively little is exported in that condition, and because masonry is
fast taking the place of carpentry in building, and stone, brick, and iron are
used instead of timber more largely than they were ten years ago. Still a
much greater quantity of unsawed lumber must have been marketed in 1860
than in 1850. It must further be admitted that the price of lumber rose
considerably between those dates, and consequently that the increase in
quantity is not to be measured by the increase in pecuniary value. Perhaps
this rise of prices may even be sufficient to make the entire difference
between the value of "sawed and planed lumber" produced in the ten years
in question by the six New England States (21 per cent.), and the six Middle
Page 204
States (15 per cent.); but the amount produced by the Western and by the
Southern States had doubled, and that returned from the Pacific States and
Territories had trebled in value in the same interval, so that there was
certainly, in those States, a large increase in the actual quantity prepared for
sale.
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 a great 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 it is also true
that, within the memory of almost every man of mature age, timber was of
so little value in that country, that the owners of private woodlands
submitted, almost without complaint, to what would be regarded elsewhere
as very aggravated trespasses upon them.[280] Under such circumstances, it
is difficult to protect the forest, whether it belong to the state or to
individuals. Property of this kind would be subject to much plunder, as well
as to frequent damage by fire. The destruction from these causes would,
indeed, considerably lessen, but would not 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. For prevention of the evils
upon which I have so long dwelt, the American people must look to the
diffusion of general intelligence on this subject, and to the enlightened self
interest, for which they are remarkable, not to the action of their local or
general legislatures. Even in France, government has moved with too slow
and hesitating a pace, and preventive measures do not yet compensate
destructive causes. The judicious remarks of Troy on this point may well be
applied to other countries than France, other measures of public policy than
the preservation of the woods. "To move softly," says he, "is to commit the
most dangerous, the most unpardonable of imprudences; it diminishes the
prestige of authority; it furnishes a triumph to the sneerer and the
incredulous; it strengthens opposition and encourages resistance; it ruins the
administration in the opinion of the people, weakens its power and
depresses its courage."[281]
Southern States had doubled, and that returned from the Pacific States and
Territories had trebled in value in the same interval, so that there was
certainly, in those States, a large increase in the actual quantity prepared for
sale.
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 a great 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 it is also true
that, within the memory of almost every man of mature age, timber was of
so little value in that country, that the owners of private woodlands
submitted, almost without complaint, to what would be regarded elsewhere
as very aggravated trespasses upon them.[280] Under such circumstances, it
is difficult to protect the forest, whether it belong to the state or to
individuals. Property of this kind would be subject to much plunder, as well
as to frequent damage by fire. The destruction from these causes would,
indeed, considerably lessen, but would not 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. For prevention of the evils
upon which I have so long dwelt, the American people must look to the
diffusion of general intelligence on this subject, and to the enlightened self
interest, for which they are remarkable, not to the action of their local or
general legislatures. Even in France, government has moved with too slow
and hesitating a pace, and preventive measures do not yet compensate
destructive causes. The judicious remarks of Troy on this point may well be
applied to other countries than France, other measures of public policy than
the preservation of the woods. "To move softly," says he, "is to commit the
most dangerous, the most unpardonable of imprudences; it diminishes the
prestige of authority; it furnishes a triumph to the sneerer and the
incredulous; it strengthens opposition and encourages resistance; it ruins the
administration in the opinion of the people, weakens its power and
depresses its courage."[281]
Page 205
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. 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, indeed, are 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 always present more or less of an
artificial character and arrangement. Both they and planted forests, which,
though certainly not few, are of 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, experience and observation have not
yet collected a sufficient stock of facts to serve for the construction of a
complete system of sylviculture; but the management 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 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
best of these is the Cours Élémentaire de Culture des Bois créé à l'École
Forestière de Nancy, par M. Lorentz, complété, et publié par A. Parade,
with a supplement under the title of Cours d'Aménagement des Forêts, par
Henri Nanquette. The Études sur l'Économie Forestière, par Jules Clavé,
which I have often quoted, presents a great number of interesting views on
this subject, and well deserves to be translated for the use of the English and
American reader; 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.
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
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. 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, indeed, are 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 always present more or less of an
artificial character and arrangement. Both they and planted forests, which,
though certainly not few, are of 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, experience and observation have not
yet collected a sufficient stock of facts to serve for the construction of a
complete system of sylviculture; but the management 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 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
best of these is the Cours Élémentaire de Culture des Bois créé à l'École
Forestière de Nancy, par M. Lorentz, complété, et publié par A. Parade,
with a supplement under the title of Cours d'Aménagement des Forêts, par
Henri Nanquette. The Études sur l'Économie Forestière, par Jules Clavé,
which I have often quoted, presents a great number of interesting views on
this subject, and well deserves to be translated for the use of the English and
American reader; 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.
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
Page 206
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.[282]
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, 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 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
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.[282]
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, 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 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
Page 207
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.[283]
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, 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 Clavé, "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 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."[284]
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
Clavé, 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."[285] Our author, however, doubtless means genera,
though he uses the word espèces. Rossmässler 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, though it is indigenous in Algeria also. We
may then safely say that Europe does not possess above forty or fifty trees
of such economical value as to be worth the special care of the forester,
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.[283]
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, 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 Clavé, "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 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."[284]
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
Clavé, 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."[285] Our author, however, doubtless means genera,
though he uses the word espèces. Rossmässler 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, though it is indigenous in Algeria also. We
may then safely say that Europe does not possess above forty or fifty trees
of such economical value as to be worth the special care of the forester,
Page 208
while the oak alone numbers not less than thirty species in the United
States,[286] and some other North American genera are almost equally
diversified.[287]
Few European trees, except those bearing edible fruit, have been
naturalized in the United States, while the American forest flora has made
large contributions to that of Europe. It is a very poor taste which has led to
the substitution of the less picturesque European for the graceful and
majestic American elm, in some public grounds in the United States. On the
other hand, the European mountain ash—which in beauty and healthfulness
of growth is superior to our own—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 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 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.[288] 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 épicéa, 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 variety of soil and climate
than almost any other spike-leaved tree, it might be well worth
transplantation.[289] The cork oak has been introduced into the United
States, I believe, and would undoubtedly thrive in the Southern section of
the Union.[290]
States,[286] and some other North American genera are almost equally
diversified.[287]
Few European trees, except those bearing edible fruit, have been
naturalized in the United States, while the American forest flora has made
large contributions to that of Europe. It is a very poor taste which has led to
the substitution of the less picturesque European for the graceful and
majestic American elm, in some public grounds in the United States. On the
other hand, the European mountain ash—which in beauty and healthfulness
of growth is superior to our own—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 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 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.[288] 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 épicéa, 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 variety of soil and climate
than almost any other spike-leaved tree, it might be well worth
transplantation.[289] The cork oak has been introduced into the United
States, I believe, and would undoubtedly thrive in the Southern section of
the Union.[290]
Page 209
In 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.[291]
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 watercourses with a
rainbow splendor of foliage, unsurpassed by the brightest groupings of the
tropical flora. It must be admitted, 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 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.
No American evergreen known to me resembles the umbrella pine
sufficiently to be a fair object of comparison with it.[292] A cedar, very
common above the Highlands on the Hudson, is extremely like the cypress,
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.[291]
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 watercourses with a
rainbow splendor of foliage, unsurpassed by the brightest groupings of the
tropical flora. It must be admitted, 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 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.
No American evergreen known to me resembles the umbrella pine
sufficiently to be a fair object of comparison with it.[292] A cedar, very
common above the Highlands on the Hudson, is extremely like the cypress,
Page 210
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. 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
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 the date palm is of the
oases of the 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. 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
traveller's eyes, is scarcely a more effectual obstacle to the gratification of
his curiosity.[293]
Sylviculture.
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. 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
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 the date palm is of the
oases of the 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. 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
traveller's eyes, is scarcely a more effectual obstacle to the gratification of
his curiosity.[293]
Sylviculture.
Page 211
The art, or, as the Continental foresters 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 I shall not be able 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 almost total want of
conveniently accessible means of information on the subject, in English-
speaking countries, will justify me in presenting it with somewhat more of
detail than would otherwise be pertinent.
The two best known methods are those distinguished as the taillis,
copse or coppice treatment,[294] 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 wherever 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. 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. If domestic animals of any species are allowed to roam
in the wood, they 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. The evergreens, once cut, do not shoot up
again,[295] and the mixed character of the forest—in many respects an
important advantage, if not an indispensable condition of growth—is lost;
[296]
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
has been so little pursued in England and America, that its nomenclature has
not been introduced into the English vocabulary, and I shall not be able 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 almost total want of
conveniently accessible means of information on the subject, in English-
speaking countries, will justify me in presenting it with somewhat more of
detail than would otherwise be pertinent.
The two best known methods are those distinguished as the taillis,
copse or coppice treatment,[294] 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 wherever 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. 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. If domestic animals of any species are allowed to roam
in the wood, they 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. The evergreens, once cut, do not shoot up
again,[295] and the mixed character of the forest—in many respects an
important advantage, if not an indispensable condition of growth—is lost;
[296]
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
Page 212
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 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 natural 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 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 a million 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 sequoia, 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 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
their maximum of stature, and this seems to be still more emphatically true
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 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 natural 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 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 a million 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 sequoia, 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 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
their maximum of stature, and this seems to be still more emphatically true
Page 213
of the artificial forest. In France, according to Clavé, "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."[297] 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 wood, in such way as to leave
convenient spaces for the growth of young trees. 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, the ill formed and sickly, as well as those 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 bear or to require 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, they 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 convenient periods afterward, 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.[298] When the forest is approaching to
maturity, the original processes already described are repeated; and as, in
different parts of an extensive forest, they would take place in different
zones, it would afford indefinitely an annual crop of firewood and timber.
The duties of the forester do not end here. It sometimes happens that the
glades left by felling the older trees are not sufficiently seeded, or that the
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."[297] 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 wood, in such way as to leave
convenient spaces for the growth of young trees. 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, the ill formed and sickly, as well as those 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 bear or to require 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, they 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 convenient periods afterward, 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.[298] When the forest is approaching to
maturity, the original processes already described are repeated; and as, in
different parts of an extensive forest, they would take place in different
zones, it would afford indefinitely an annual crop of firewood and timber.
The duties of the forester do not end here. It sometimes happens that the
glades left by felling the older trees are not sufficiently seeded, or that the
Page 214
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.
One of the most important rules in the administration of the forest is the
absolute exclusion of domestic quadrupeds from every wood which is not
destined to be cleared. No growth of young trees is possible where cattle are
admitted to pasture at any season of the year, though they are undoubtedly
most destructive while trees are in leaf.[299]
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 larvæ 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 of the eggs, by simple but
expensive means, has proved the only effectual remedy.[300]
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
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,
proportioned in the new crop. In this case, seed must be artificially sown, or
young trees planted in the vacancies.
One of the most important rules in the administration of the forest is the
absolute exclusion of domestic quadrupeds from every wood which is not
destined to be cleared. No growth of young trees is possible where cattle are
admitted to pasture at any season of the year, though they are undoubtedly
most destructive while trees are in leaf.[299]
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 larvæ 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 of the eggs, by simple but
expensive means, has proved the only effectual remedy.[300]
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
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,
Page 215
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."[301]
Besides these evils, the removal of the leaves deprives the soil 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.
The annual lopping and trimming of trees for fuel, so common in
Europe, is fatal to the higher uses of the forest, but where small groves are
made, or rows of trees planted, for no other purpose than to secure a supply
of firewood, or to serve as supports for the vine, it is often very
advantageous. The willows, and many other trees, bear polling for a long
series of years without apparent diminution of growth of branches, and
though certainly a polled, or, to use an old English word, a doddered tree, is
in general a melancholy object, yet it must be admitted that the aspect of
some species—the American locust, Robinia pseudacacia, for instance—
when young, is improved by this process.[302]
I have spoken of the needs of agriculture as a principal cause of the
destruction of the forest, and of domestic cattle as particularly injurious to
the growth of young trees. But these animals affect the forest, indirectly, in
a still more important way, because 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 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
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."[301]
Besides these evils, the removal of the leaves deprives the soil 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.
The annual lopping and trimming of trees for fuel, so common in
Europe, is fatal to the higher uses of the forest, but where small groves are
made, or rows of trees planted, for no other purpose than to secure a supply
of firewood, or to serve as supports for the vine, it is often very
advantageous. The willows, and many other trees, bear polling for a long
series of years without apparent diminution of growth of branches, and
though certainly a polled, or, to use an old English word, a doddered tree, is
in general a melancholy object, yet it must be admitted that the aspect of
some species—the American locust, Robinia pseudacacia, for instance—
when young, is improved by this process.[302]
I have spoken of the needs of agriculture as a principal cause of the
destruction of the forest, and of domestic cattle as particularly injurious to
the growth of young trees. But these animals affect the forest, indirectly, in
a still more important way, because 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 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 216
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 plough land.[303]
In fertile countries, like the United States, the foreign demand for
animal and vegetable aliment, for cotton, and for tobacco, much enlarges
the sphere of agricultural operations, and, of course, prompts further
encroachments upon the forest. The commerce in these articles, therefore,
constitutes in America a special cause of the destruction of the woods,
which does not exist in the numerous states of the Old World that derive the
raw material of their mechanical industry from distant lands, and import
many articles of vegetable food or luxury which their own climates cannot
advantageously produce.
The growth of arboreal vegetation is so slow 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 must be actuated by higher motives than those of an investment 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 plough land.[303]
In fertile countries, like the United States, the foreign demand for
animal and vegetable aliment, for cotton, and for tobacco, much enlarges
the sphere of agricultural operations, and, of course, prompts further
encroachments upon the forest. The commerce in these articles, therefore,
constitutes in America a special cause of the destruction of the woods,
which does not exist in the numerous states of the Old World that derive the
raw material of their mechanical industry from distant lands, and import
many articles of vegetable food or luxury which their own climates cannot
advantageously produce.
The growth of arboreal vegetation is so slow 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 must be actuated by higher motives than those of an investment the
Page 217
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 two or three
generations, more than repay its original cost, still, in general, the value of
its timber will not return the capital expended and the interest accrued.[304]
But when we consider the immense collateral advantages derived from the
presence, the terrible evils necessarily resulting from the destruction of the
forest, both the preservation of existing woods, and the far more costly
extension of them where they have been unduly reduced, are among the
most obvious of the duties which this age owes to those that are to come
after it. Especially is this obligation incumbent upon Americans. No
civilized people profits so largely from the toils and sacrifices of its
immediate predecessors as they; no generations have ever sown so liberally,
and, in their own persons, reaped so scanty a return, as the pioneers of
Anglo-American social life. We can repay our debt to our noble forefathers
only by a like magnanimity, by a like self-forgetting care for the moral and
material interests of our own posterity.
Instability of American Life.
All human institutions, associate arrangements, modes of life, have their
characteristic imperfections. The natural, perhaps the necessary defect of
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.[305] 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 for 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 broadly characterized distinctions of rural surface—woodland and
plough land—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
posterity; for if, in rare cases, an artificial forest may, in two or three
generations, more than repay its original cost, still, in general, the value of
its timber will not return the capital expended and the interest accrued.[304]
But when we consider the immense collateral advantages derived from the
presence, the terrible evils necessarily resulting from the destruction of the
forest, both the preservation of existing woods, and the far more costly
extension of them where they have been unduly reduced, are among the
most obvious of the duties which this age owes to those that are to come
after it. Especially is this obligation incumbent upon Americans. No
civilized people profits so largely from the toils and sacrifices of its
immediate predecessors as they; no generations have ever sown so liberally,
and, in their own persons, reaped so scanty a return, as the pioneers of
Anglo-American social life. We can repay our debt to our noble forefathers
only by a like magnanimity, by a like self-forgetting care for the moral and
material interests of our own posterity.
Instability of American Life.
All human institutions, associate arrangements, modes of life, have their
characteristic imperfections. The natural, perhaps the necessary defect of
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.[305] 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 for 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 broadly characterized distinctions of rural surface—woodland and
plough land—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
Page 218
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.
Note on word watershed, omitted on p. 257.—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 watershed, 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. 197. 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 sense and spelling.
foresee, and would thus help us to become, more emphatically, a well-
ordered and stable commonwealth, and, not less conspicuously, a people of
progress.
Note on word watershed, omitted on p. 257.—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 watershed, 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. 197. 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 sense and spelling.
Page 219
CHAPTER IV.
T H E WA T E R S .
LAND ARTIFICIALLY WON FROM THE WATERS: a, EXCLUSION OF THE SEA BY DIKING;
b, DRAINING OF LAKES AND MARSHES; c, GEOGRAPHICAL INFLUENCE OF SUCH
OPERATIONS—LOWERING OF LAKES—MOUNTAIN LAKES—CLIMATIC EFFECTS OF
DRAINING LAKES AND MARSHES—GEOGRAPHICAL AND CLIMATIC EFFECTS OF
AQUEDUCTS, RESERVOIRS, AND CANALS—SURFACE AND UNDERDRAINING, AND
THEIR CLIMATIC AND GEOGRAPHICAL EFFECTS—IRRIGATION AND ITS CLIMATIC
AND GEOGRAPHICAL EFFECTS.
INUNDATIONS AND TORRENTS: a, RIVER EMBANKMENTS; b, FLOODS OF THE
ARDÈCHE; c, CRUSHING FORCE OF TORRENTS; d, INUNDATIONS OF 1856 IN FRANCE; e,
REMEDIES AGAINST INUNDATIONS—CONSEQUENCES IF THE NILE HAD BEEN
CONFINED BY LATERAL DIKES.
IMPROVEMENTS IN THE VAL DI CHIANA—IMPROVEMENTS IN THE TUSCAN
MAREMME—OBSTRUCTION OF RIVER MOUTHS—SUBTERRANEAN WATERS—
ARTESIAN WELLS—ARTIFICIAL SPRINGS—ECONOMIZING PRECIPITATION.
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, he
has promoted the deposit of solid matter in the sea, thus reducing its depth,
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, lighthouses, 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
T H E WA T E R S .
LAND ARTIFICIALLY WON FROM THE WATERS: a, EXCLUSION OF THE SEA BY DIKING;
b, DRAINING OF LAKES AND MARSHES; c, GEOGRAPHICAL INFLUENCE OF SUCH
OPERATIONS—LOWERING OF LAKES—MOUNTAIN LAKES—CLIMATIC EFFECTS OF
DRAINING LAKES AND MARSHES—GEOGRAPHICAL AND CLIMATIC EFFECTS OF
AQUEDUCTS, RESERVOIRS, AND CANALS—SURFACE AND UNDERDRAINING, AND
THEIR CLIMATIC AND GEOGRAPHICAL EFFECTS—IRRIGATION AND ITS CLIMATIC
AND GEOGRAPHICAL EFFECTS.
INUNDATIONS AND TORRENTS: a, RIVER EMBANKMENTS; b, FLOODS OF THE
ARDÈCHE; c, CRUSHING FORCE OF TORRENTS; d, INUNDATIONS OF 1856 IN FRANCE; e,
REMEDIES AGAINST INUNDATIONS—CONSEQUENCES IF THE NILE HAD BEEN
CONFINED BY LATERAL DIKES.
IMPROVEMENTS IN THE VAL DI CHIANA—IMPROVEMENTS IN THE TUSCAN
MAREMME—OBSTRUCTION OF RIVER MOUTHS—SUBTERRANEAN WATERS—
ARTESIAN WELLS—ARTIFICIAL SPRINGS—ECONOMIZING PRECIPITATION.
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, he
has promoted the deposit of solid matter in the sea, thus reducing its depth,
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, lighthouses, 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
Page 220
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.
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. 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 sea beach. 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 these results are all in a considerable degree
subject to control, or rather to direction and resistance, by human power,
and it is in guiding and combating them that man has achieved some of his
most remarkable and 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
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.
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. 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 sea beach. 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 these results are all in a considerable degree
subject to control, or rather to direction and resistance, by human power,
and it is in guiding and combating them that man has achieved some of his
most remarkable and 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
Page 221
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 an ingenuity which has
contrived means of executing them, and which gives promise of yet greater
performance in time to come.
Men have ceased to admire the 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 surpass the vastest remains of
ancient architectural art in mass and weight of matter, 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 railroad has been constructed at twice the cost
which would now build that stupendous monument. 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!"
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
land.
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 an ingenuity which has
contrived means of executing them, and which gives promise of yet greater
performance in time to come.
Men have ceased to admire the 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 surpass the vastest remains of
ancient architectural art in mass and weight of matter, 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 railroad has been constructed at twice the cost
which would now build that stupendous monument. 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!"
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
land.
Page 222
a. Exclusion of the Sea by Diking.
The draining of the Lincolnshire fens in England, which converted
about 400,000 acres of marsh, pool, and tide-washed flat into plough land
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, Frisic, 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 are much 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 these
terrible inundations are recorded, and in very 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. 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
The draining of the Lincolnshire fens in England, which converted
about 400,000 acres of marsh, pool, and tide-washed flat into plough land
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, Frisic, 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 are much 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 these
terrible inundations are recorded, and in very 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. 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
Page 223
permanent conquest of its territory, should have been earlier studied and
carried to higher perfection in the latter countries, than in England, which
had much 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.
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.[306] 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.[307] 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 accumulation 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 until after the middle of the fifteenth century.
[308]
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,
carried to higher perfection in the latter countries, than in England, which
had much 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.
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.[306] 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.[307] 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 accumulation 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 until after the middle of the fifteenth century.
[308]
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,
Page 224
equal to eight hundred and seventy-seven thousand two hundred and forty
acres, which is one tenth of the area of the kingdom.[309] 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."[310] 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.[311]
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 thousand bunder, or ninety-one thousand four hundred acres of
recovered land, have been lost by the destruction of the dikes which
protected them.[312] 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.
acres, which is one tenth of the area of the kingdom.[309] 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."[310] 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.[311]
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 thousand bunder, or ninety-one thousand four hundred acres of
recovered land, have been lost by the destruction of the dikes which
protected them.[312] 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.
Page 225
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 sandbanks, 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.
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
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 greater 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 sandbanks 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
maritime currents are constantly changing, in consequence of the variability
of the winds, and the shifting of the sandbanks, 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.
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
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 greater 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 sandbanks 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
Page 226
is, accordingly, very slow, and it is seldom advantageous to delay longer the
operation of diking."[313]
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.[314]
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 Frisic,
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
presenting such information as can be gathered from works of a more
popular character.[315]
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
operation of diking."[313]
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.[314]
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 Frisic,
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
presenting such information as can be gathered from works of a more
popular character.[315]
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
Page 227
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 sea water
also, when heavy or long-continued west winds drove it landward. 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 to 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
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 (sommer-deich, pl.
sommer-deiche, German; zomerkaai, zomerkade, pl. zomerkaaie,
zomerkaden, Dutch). 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
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 sea water
also, when heavy or long-continued west winds drove it landward. 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 to 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
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 (sommer-deich, pl.
sommer-deiche, German; zomerkaai, zomerkade, pl. zomerkaaie,
zomerkaden, Dutch). 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
Page 228
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 sandbanks, 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.[316] 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 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 revêtement.[317] 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, 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
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 sandbanks, 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.[316] 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 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 revêtement.[317] 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, 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
Page 229
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;
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.[318]
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
subsoil 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.[319]
b. Draining of Lakes and Marshes.
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 and 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 were reclaimed from the waters, and added
to the agricultural domain of the Netherlands, between 1815 and 1858. The
most important of these undertakings was the draining of the Lake of
Haarlem, and for this purpose some of the most powerful hydraulic engines
ever constructed were designed and executed.[320] The origin of this lake is
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;
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.[318]
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
subsoil 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.[319]
b. Draining of Lakes and Marshes.
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 and 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 were reclaimed from the waters, and added
to the agricultural domain of the Netherlands, between 1815 and 1858. The
most important of these undertakings was the draining of the Lake of
Haarlem, and for this purpose some of the most powerful hydraulic engines
ever constructed were designed and executed.[320] The origin of this lake is
Page 230
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.
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 afterward covered by the Lake of Haarlem, and they have more
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 northwest winds, those of the Lake of Haarlem were raised
proportionally and driven southward, while winds from the south tended to
create a flow in the opposite direction. The shores of the lake were
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.
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 afterward covered by the Lake of Haarlem, and they have more
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 northwest winds, those of the Lake of Haarlem were raised
proportionally and driven southward, while winds from the south tended to
create a flow in the opposite direction. The shores of the lake were
Page 231
everywhere low, and though in the course of the eighty years between 1767
and 1848 more than £350,000 or $1,700,000 had been expended in
checking its encroachments, it often burst its barriers, and produced
destructive inundations. On the 29th of November, 1836, a south wind
brought its waters to the very gates of Amsterdam, and on the 26th of
December of the same year, in a northwest 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 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,[321] 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 £661,000 sterling or
$3,200,000. The unsold lands were valued at more than £6,000 or nearly
$30,000, and as the total cost was £764,500 or about $3,700,000, the direct
loss to the state, exclusive of interest on the capital expended, may be stated
at £100,000 or something less than $500,000.
and 1848 more than £350,000 or $1,700,000 had been expended in
checking its encroachments, it often burst its barriers, and produced
destructive inundations. On the 29th of November, 1836, a south wind
brought its waters to the very gates of Amsterdam, and on the 26th of
December of the same year, in a northwest 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 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,[321] 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 £661,000 sterling or
$3,200,000. The unsold lands were valued at more than £6,000 or nearly
$30,000, and as the total cost was £764,500 or about $3,700,000, the direct
loss to the state, exclusive of interest on the capital expended, may be stated
at £100,000 or something less than $500,000.
Page 232
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 investment for a capital of not less than £400,000 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.
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,
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 investment for a capital of not less than £400,000 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.
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,
Page 233
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
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
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 watercourses on one side, and exposing the coast to erosion
by the sea upon the other.
c. Geographical Influence of such Operations.
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 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.
Lowering of Lakes.
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
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
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 watercourses on one side, and exposing the coast to erosion
by the sea upon the other.
c. Geographical Influence of such Operations.
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 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.
Lowering of Lakes.
Page 234
The hydraulic works of the Netherlands and of the neighboring states
are of such magnitude, that 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.
One of the best known of these 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 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, but 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 Dionysins of Halicarnassus, and it is by no means impossible that, in an
are of such magnitude, that 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.
One of the best known of these 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 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, but 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 Dionysins of Halicarnassus, and it is by no means impossible that, in an
Page 235
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 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, according to
the character of the seasons. It 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 Cæsar had
proposed the construction of a tunnel to drain the lake, 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 seems to have answered its design for some
centuries. 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.
Works have now been some years in progress 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 this tunnel is
18,634 feet, or rather more than three miles and a half. Of course, it is one
of the longest subterranean galleries yet executed in Europe, and it offers
many curious particulars in its original design which cannot here be
described. The difference between the highest and the lowest known levels
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 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, according to
the character of the seasons. It 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 Cæsar had
proposed the construction of a tunnel to drain the lake, 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 seems to have answered its design for some
centuries. 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.
Works have now been some years in progress 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 this tunnel is
18,634 feet, or rather more than three miles and a half. Of course, it is one
of the longest subterranean galleries yet executed in Europe, and it offers
many curious particulars in its original design which cannot here be
described. The difference between the highest and the lowest known levels
Page 236
of the surface of the lake amounts to at least forty feet, and the difference of
area covered at these respective stages is not much less than eight thousand
acres. The tunnel will reduce the water to a much lower point, and it is
computed that, including the lands occasionally overflowed, not less than
forty thousand acres of as fertile soil as any in Italy will be recovered from
the lake and permanently secured from inundation by its waters.
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.[322] They are sometimes attended with wholly unexpected
evils, as, for example, in the case of Barton Pond, in Vermont, and in that of
the Lake Storsjö, 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 toward 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.
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
area covered at these respective stages is not much less than eight thousand
acres. The tunnel will reduce the water to a much lower point, and it is
computed that, including the lands occasionally overflowed, not less than
forty thousand acres of as fertile soil as any in Italy will be recovered from
the lake and permanently secured from inundation by its waters.
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.[322] They are sometimes attended with wholly unexpected
evils, as, for example, in the case of Barton Pond, in Vermont, and in that of
the Lake Storsjö, 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 toward 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.
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 237
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.
Mountain 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 negligence of man
has permitted to disappear. Auguste de Gasparin, brother of the illustrious
agriculturist, demonstrated more than thirty years ago, in an original paper,
that many natural dikes formerly existed in the mountain valleys, which
have been swept away by the waters. He proposed to rebuild and to
multiply them. This interesting suggestion has reappeared several times
since, but has met with strong opposition from skilful engineers. It would,
nevertheless, be well to try the experiment of creating artificial lakes which
should fill themselves with the water of melting snows and deluging rains,
to be drawn out in times of drought. If this plan has able opposers, it has
also warm advocates. Experience alone can decide the question."[323]
depositing their burden as before in the still waters of the lakes.
Mountain 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 negligence of man
has permitted to disappear. Auguste de Gasparin, brother of the illustrious
agriculturist, demonstrated more than thirty years ago, in an original paper,
that many natural dikes formerly existed in the mountain valleys, which
have been swept away by the waters. He proposed to rebuild and to
multiply them. This interesting suggestion has reappeared several times
since, but has met with strong opposition from skilful engineers. It would,
nevertheless, be well to try the experiment of creating artificial lakes which
should fill themselves with the water of melting snows and deluging rains,
to be drawn out in times of drought. If this plan has able opposers, it has
also warm advocates. Experience alone can decide the question."[323]
Page 238
Climatic Effects of Draining Lakes and Marshes.
The draining of lakes, marshes, and other superficial accumulations of
moisture, reduces the water surface of a country, and, of course, the
evaporation from it. Lakes, too, in elevated positions, lose a part of their
water by infiltration, and thereby supply other lakes, springs, and rivulets at
lower levels. Hence, it is evident that the draining of such waters, if carried
on upon a large scale, must affect both the humidity and the temperature of
the atmosphere, and the permanent supply of water for extensive districts.
[324]
Geographical and Climatic Effects of Aqueducts,
Reservoirs, and Canals.
Many 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. Similar effects must have followed from the
construction of the numerous aqueducts which supplied ancient Rome with
such a profuse abundance of water. 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, 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 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
The draining of lakes, marshes, and other superficial accumulations of
moisture, reduces the water surface of a country, and, of course, the
evaporation from it. Lakes, too, in elevated positions, lose a part of their
water by infiltration, and thereby supply other lakes, springs, and rivulets at
lower levels. Hence, it is evident that the draining of such waters, if carried
on upon a large scale, must affect both the humidity and the temperature of
the atmosphere, and the permanent supply of water for extensive districts.
[324]
Geographical and Climatic Effects of Aqueducts,
Reservoirs, and Canals.
Many 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. Similar effects must have followed from the
construction of the numerous aqueducts which supplied ancient Rome with
such a profuse abundance of water. 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, 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 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
Page 239
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;[325] 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.
Climatic and Geographical Effects of Surface and
Underground Draining.
I have commenced this chapter with a description of the dikes and other
hydraulic works of the Netherland engineers, because the geographical
results of such operations are more obvious and more easily measured,
though certainly not more important, than those of the 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.
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;[325] 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.
Climatic and Geographical Effects of Surface and
Underground Draining.
I have commenced this chapter with a description of the dikes and other
hydraulic works of the Netherland engineers, because the geographical
results of such operations are more obvious and more easily measured,
though certainly not more important, than those of the 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 240
Surface and Under-draining and their Effects.
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, many
small ridges and 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.
The beneficial effects of surface drainage, the necessity of extending the
fields as population increased, and the inconveniences resulting from the
presence of marshes in otherwise improved regions, must have suggested at
a very early period of human industry the expediency of converting bogs
and swamps into dry land by drawing off their waters; and it would not be
long after the introduction of this practice before further acquisition of
agricultural territory would be made by lowering the outlet of small ponds
and lakes, and adding the ground they covered to the domain of the
husbandman.
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
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, many
small ridges and 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.
The beneficial effects of surface drainage, the necessity of extending the
fields as population increased, and the inconveniences resulting from the
presence of marshes in otherwise improved regions, must have suggested at
a very early period of human industry the expediency of converting bogs
and swamps into dry land by drawing off their waters; and it would not be
long after the introduction of this practice before further acquisition of
agricultural territory would be made by lowering the outlet of small ponds
and lakes, and adding the ground they covered to the domain of the
husbandman.
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
Page 241
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 apparently profitable, exist in Great Britain, and it is,
therefore, very natural that the wealthy and intelligent farmers of England
should have carried this 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 Réné, in the first half of the fifteenth century, 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.[326] 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, in behalf
of the municipal authorities, by Girard and Parent Duchatelet, in the latter
year. The report of these gentlemen, published in the Annales des Ponts et
Chaussées for 1833, second half year, is full of curious and instructive facts
respecting the position and distribution of the subterranean waters under
required to make this mode of rural improvement, if not absolutely
necessary, at least apparently profitable, exist in Great Britain, and it is,
therefore, very natural that the wealthy and intelligent farmers of England
should have carried this 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 Réné, in the first half of the fifteenth century, 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.[326] 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, in behalf
of the municipal authorities, by Girard and Parent Duchatelet, in the latter
year. The report of these gentlemen, published in the Annales des Ponts et
Chaussées for 1833, second half year, is full of curious and instructive facts
respecting the position and distribution of the subterranean waters under
Page 242
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 this latter, 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 upon 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 Seine, that it cannot possibly
affect it to a sensible degree. I would, however, advise determined water
drinkers living at Paris to adopt his conclusions, without studying his facts
and his arguments; for it is quite possible that he may convert his readers to
a faith opposite to his own, and that they will finally agree with the poet
who held water an "ignoble beverage."
Climatic and Geographical Effects of Surface
Draining.
When we remove water from the surface, we diminish the evaporation
from it, and, of course, the refrigeration which accompanies all evaporation
is diminished in proportion. Hence superficial draining ought to be attended
with an elevation of atmospheric temperature, and, in cold countries, it
might be expected to lessen the frequency 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 very large scale, but still we have thermometric
data sufficient to warrant 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
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 this latter, 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 upon 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 Seine, that it cannot possibly
affect it to a sensible degree. I would, however, advise determined water
drinkers living at Paris to adopt his conclusions, without studying his facts
and his arguments; for it is quite possible that he may convert his readers to
a faith opposite to his own, and that they will finally agree with the poet
who held water an "ignoble beverage."
Climatic and Geographical Effects of Surface
Draining.
When we remove water from the surface, we diminish the evaporation
from it, and, of course, the refrigeration which accompanies all evaporation
is diminished in proportion. Hence superficial draining ought to be attended
with an elevation of atmospheric temperature, and, in cold countries, it
might be expected to lessen the frequency 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 very large scale, but still we have thermometric
data sufficient to warrant 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
Page 243
particularly observable in very cold climates, as, for example, in Lapland.
[327]
In England, under-drains are not generally laid below the reach of daily
variations of temperature, or below a point from which moisture 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. 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.
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
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
[327]
In England, under-drains are not generally laid below the reach of daily
variations of temperature, or below a point from which moisture 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. 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.
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
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
Page 244
drive the machinery for which it was once amply sufficient, and scarcely
even waters the herds that pasture upon its margin.[328]
Irrigation and its Climatic and Geographical Effects.
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 barbarism, and created for itself the arts of
social life.[329] 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, 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
even waters the herds that pasture upon its margin.[328]
Irrigation and its Climatic and Geographical Effects.
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 barbarism, and created for itself the arts of
social life.[329] 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, 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
Page 245
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, plough land 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.
There are few things in Continental husbandry which surprise English
or American observers so much as the extent to which irrigation is
employed 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. The summers in Northern
Italy, though longer, are very often not warmer than in New England; and in
ordinary years, the summer rains are as frequent and as abundant in the
former country as in the latter. Yet in Piedmont and Lombardy, irrigation is
bestowed upon almost every crop, while in New England it is never
employed at all in farming husbandry, or indeed for any purpose except in
kitchen gardens, and possibly, in rare cases, in some other small branch of
agricultural industry.[330]
The summers in Egypt, in Syria, and in Asia Minor and even Rumelia,
are almost rainless. In such climates, the necessity of irrigation is obvious,
and the loss of the ancient means of furnishing it readily explains the
diminished fertility of most of the countries in question.[331] 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.[332] 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
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, plough land 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.
There are few things in Continental husbandry which surprise English
or American observers so much as the extent to which irrigation is
employed 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. The summers in Northern
Italy, though longer, are very often not warmer than in New England; and in
ordinary years, the summer rains are as frequent and as abundant in the
former country as in the latter. Yet in Piedmont and Lombardy, irrigation is
bestowed upon almost every crop, while in New England it is never
employed at all in farming husbandry, or indeed for any purpose except in
kitchen gardens, and possibly, in rare cases, in some other small branch of
agricultural industry.[330]
The summers in Egypt, in Syria, and in Asia Minor and even Rumelia,
are almost rainless. In such climates, the necessity of irrigation is obvious,
and the loss of the ancient means of furnishing it readily explains the
diminished fertility of most of the countries in question.[331] 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.[332] 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
Page 246
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 Idumæa. 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.[333] 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 plenty are bare of
vegetation, and seared by the scorching winds of the desert.
In Southern Europe, in the Turkish Empire, and in many other countries,
a very large proportion of the surface is, if not absolutely flooded, at least
thoroughly moistened by irrigation, a great number of times in the course of
every season, and this, especially, at periods when it would otherwise be
quite dry, and when, too, the power of the sun and the capacity of the air for
absorbing moisture are greatest. Hence it is obvious that the amount of
evaporation from the earth in these countries, and, of course, the humidity
and the temperature of both the soil and the atmosphere in contact with it,
must be much affected by the practice of irrigation. The cultivable area of
Egypt, or the space accessible to cultivation, between desert and desert, is
more than seven thousand square statute miles. 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 confined to an area of five or six
thousand square miles, nearly the whole of which is regularly and
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 Idumæa. 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.[333] 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 plenty are bare of
vegetation, and seared by the scorching winds of the desert.
In Southern Europe, in the Turkish Empire, and in many other countries,
a very large proportion of the surface is, if not absolutely flooded, at least
thoroughly moistened by irrigation, a great number of times in the course of
every season, and this, especially, at periods when it would otherwise be
quite dry, and when, too, the power of the sun and the capacity of the air for
absorbing moisture are greatest. Hence it is obvious that the amount of
evaporation from the earth in these countries, and, of course, the humidity
and the temperature of both the soil and the atmosphere in contact with it,
must be much affected by the practice of irrigation. The cultivable area of
Egypt, or the space accessible to cultivation, between desert and desert, is
more than seven thousand square statute miles. 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 confined to an area of five or six
thousand square miles, nearly the whole of which is regularly and
Page 247
constantly watered when not covered by the inundation, except in the short
interval between the harvest and the rise of the waters. For nearly half of the
year, then, irrigation adds five or six thousand square miles, or more than a
square equatorial degree, to the evaporable 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.[334] The fresh-water canals now constructing, in connection
with the works for the Suez canal, will not only restore the long abandoned
fields east of the Nile, but add to the arable soil of Egypt hundreds of square
miles of newly reclaimed desert, and thus still further increase the climatic
effects of irrigation.[335]
The Nile receives not a single tributary in its course through Egypt;
there is not so much as one living spring in the whole land,[336] 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.
[337]
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 sustaining as dense a population as has ever existed in any
part of the world.[338] 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.[339]
interval between the harvest and the rise of the waters. For nearly half of the
year, then, irrigation adds five or six thousand square miles, or more than a
square equatorial degree, to the evaporable 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.[334] The fresh-water canals now constructing, in connection
with the works for the Suez canal, will not only restore the long abandoned
fields east of the Nile, but add to the arable soil of Egypt hundreds of square
miles of newly reclaimed desert, and thus still further increase the climatic
effects of irrigation.[335]
The Nile receives not a single tributary in its course through Egypt;
there is not so much as one living spring in the whole land,[336] 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.
[337]
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 sustaining as dense a population as has ever existed in any
part of the world.[338] 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.[339]
Page 248
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. In general, it may be said 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 withdrawn from the canals at any one
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.
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
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 of land 45,000,000 cubic mètres of water, which is equal to the
entire volume of the Seine, at an ordinary flood, or a rise of three mètres
above the hydrometer at the bridge of La Tournelle at Paris."[340] Niel states
the quantity of land irrigated in the former kingdom of Sardinia, including
Savoy, in 1856, at 240,000 hectares, or not much less 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 France did not exceed
100,000 hectares, or 247,000 acres, while those in Lombardy amounted to
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. In general, it may be said 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 withdrawn from the canals at any one
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.
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
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 of land 45,000,000 cubic mètres of water, which is equal to the
entire volume of the Seine, at an ordinary flood, or a rise of three mètres
above the hydrometer at the bridge of La Tournelle at Paris."[340] Niel states
the quantity of land irrigated in the former kingdom of Sardinia, including
Savoy, in 1856, at 240,000 hectares, or not much less 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 France did not exceed
100,000 hectares, or 247,000 acres, while those in Lombardy amounted to
Page 249
450,000 hectares, more than 1,100,000 acres.[341] 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, of the
Mediterranean islands, of the Spanish peninsula, of Turkey in Europe and in
Asia Minor, of 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. 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.[342] The rice grounds
and the marcite of Lombardy are not included in these estimates of the
amount of water applied. Arrangements are concluded, and new plans
proposed, for an immense increase of the lands fertilized by irrigation in
France 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 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.[343] 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 completely absorbed, so that it does
not reach the river which it naturally feeds, except in such proportion as it is
conveyed to it by infiltration. 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 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 commenced 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
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, of the
Mediterranean islands, of the Spanish peninsula, of Turkey in Europe and in
Asia Minor, of 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. 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.[342] The rice grounds
and the marcite of Lombardy are not included in these estimates of the
amount of water applied. Arrangements are concluded, and new plans
proposed, for an immense increase of the lands fertilized by irrigation in
France 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 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.[343] 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 completely absorbed, so that it does
not reach the river which it naturally feeds, except in such proportion as it is
conveyed to it by infiltration. 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 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 commenced 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
Page 250
climate; for the soil is thoroughly saturated during the inundation, and
infiltration from the Nile continues to supply a considerable amount of
humidity in the dryest season. Linant Bey computed that twenty-nine cubic
mètres per day sufficed to irrigate a hectare in the Delta.[344] This is
equivalent to a fall of rain of two millimètres and nine tenths per day, or, if
we suppose water to be applied for one hundred and fifty days during the
dry season, to a total precipitation of 435 millimètres, about seventeen
inches and one third. Taking the area of actually cultivated soil in Egypt at
the low estimate of 3,600,000 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 61,000,000 cubic yards, which—the mean
daily delivery of the Nile being in round numbers 320,000,000 cubic yards
—is nearly one fifth of the average quantity of water contributed to the
Mediterranean by that river.
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 Slave States of the American
Union and in Italy. The climate of the Southern States is 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.
[345]
The neighborhood of the rice fields is 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 Escourrou 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 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 myriamètre, 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
infiltration from the Nile continues to supply a considerable amount of
humidity in the dryest season. Linant Bey computed that twenty-nine cubic
mètres per day sufficed to irrigate a hectare in the Delta.[344] This is
equivalent to a fall of rain of two millimètres and nine tenths per day, or, if
we suppose water to be applied for one hundred and fifty days during the
dry season, to a total precipitation of 435 millimètres, about seventeen
inches and one third. Taking the area of actually cultivated soil in Egypt at
the low estimate of 3,600,000 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 61,000,000 cubic yards, which—the mean
daily delivery of the Nile being in round numbers 320,000,000 cubic yards
—is nearly one fifth of the average quantity of water contributed to the
Mediterranean by that river.
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 Slave States of the American
Union and in Italy. The climate of the Southern States is 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.
[345]
The neighborhood of the rice fields is 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 Escourrou 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 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 myriamètre, 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
Page 251
crop, it propagates still further the evils under which it had itself suffered,
and, of course, the mischief is a growing one."[346]
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.
Recent observations in India, a notice of which I find in an account of a
meeting of the Asiatic Society in the Athenæum of December 20, 1862, No.
1834, suggest a possible explanation of this fact. At this meeting, Professor
Medlicott read an essay on "the saline efflorescence called 'Reh' and
'Kuller,'" which 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. Mr. Medlicott pronounces "these salts (which,
in small quantities are favorable to fertility of soil) 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 at the seasons when their 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 that
remote antiquity when the Nile valley received its earliest inhabitants. 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,
and, of course, the mischief is a growing one."[346]
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.
Recent observations in India, a notice of which I find in an account of a
meeting of the Asiatic Society in the Athenæum of December 20, 1862, No.
1834, suggest a possible explanation of this fact. At this meeting, Professor
Medlicott read an essay on "the saline efflorescence called 'Reh' and
'Kuller,'" which 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. Mr. Medlicott pronounces "these salts (which,
in small quantities are favorable to fertility of soil) 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 at the seasons when their 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 that
remote antiquity when the Nile valley received its earliest inhabitants. 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,
Page 252
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.
INUNDATIONS AND TORRENTS.
be more likely to dissolve salts than to deposit them.
INUNDATIONS AND TORRENTS.
Page 253
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 the only 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 causes, the restoration of the woods is not, under present
circumstances, to be hoped for. Even where that measure is feasible and in
actual process of execution, a great number of years must elapse before the
action of the destructive causes in question can be arrested or perhaps even
sensibly mitigated by it. Besides this, leaving out of view the objections
urged by Belgrand and his followers to the generally received opinions
concerning the beneficial influence of the forest as respects river
inundations—for no one disputes its importance in preventing the formation
and limiting the ravages of mountain torrents—floods will always occur in
years of excessive precipitation, whether the surface of the soil be generally
cleared or generally wooded.
Physical improvement in this respect, then, cannot he confined to
preventive measures, but, in countries subject to damage by inundation,
means must he 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.
a. River Embankments.
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 the only 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 causes, the restoration of the woods is not, under present
circumstances, to be hoped for. Even where that measure is feasible and in
actual process of execution, a great number of years must elapse before the
action of the destructive causes in question can be arrested or perhaps even
sensibly mitigated by it. Besides this, leaving out of view the objections
urged by Belgrand and his followers to the generally received opinions
concerning the beneficial influence of the forest as respects river
inundations—for no one disputes its importance in preventing the formation
and limiting the ravages of mountain torrents—floods will always occur in
years of excessive precipitation, whether the surface of the soil be generally
cleared or generally wooded.
Physical improvement in this respect, then, cannot he confined to
preventive measures, but, in countries subject to damage by inundation,
means must he 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.
a. River Embankments.
Page 254
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. The necessity of such embankments usually arises from the gradual
elevation of the bed of 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 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 afterward 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. The bank must now be raised in proportion, and
these processes would be repeated and repeated indefinitely, had not nature
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.
Few rivers, like the Nile, more than compensate by the fertilizing
properties of their water and their slime for the damage they may do in
inundations, and, consequently, there are few whose floods are not an object
of dread, few whose encroachments upon their banks are not a source of
constant anxiety and expense to the proprietors of the lands through which
they flow. River dikes, for confining the spread of currents at high water,
are of great antiquity in the East, and those of the Po and its tributaries were
begun before we have any trustworthy physical or political annals of the
provinces upon their borders. From the earliest ages, the Italian hydraulic
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. The necessity of such embankments usually arises from the gradual
elevation of the bed of 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 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 afterward 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. The bank must now be raised in proportion, and
these processes would be repeated and repeated indefinitely, had not nature
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.
Few rivers, like the Nile, more than compensate by the fertilizing
properties of their water and their slime for the damage they may do in
inundations, and, consequently, there are few whose floods are not an object
of dread, few whose encroachments upon their banks are not a source of
constant anxiety and expense to the proprietors of the lands through which
they flow. River dikes, for confining the spread of currents at high water,
are of great antiquity in the East, and those of the Po and its tributaries were
begun before we have any trustworthy physical or political annals of the
provinces upon their borders. From the earliest ages, the Italian hydraulic
Page 255
engineers have stood in the front rank of their profession, and the Italian
literature of this branch of material improvement is exceedingly
voluminous. But the countries for which I write have no rivers like the Po,
no plains like those of Lombardy, and the dangers to which the inhabitants
of English and American river banks are exposed are more nearly analogous
to those that threaten the soil and population in the valleys and plains of
France, than to the perils and losses of the Lombard. The writings of the
Italian hydrographers, too, though rich in professional instruction, are less
accessible to foreigners and less adapted to popular use than those of
French engineers.[347] For these reasons I shall take my citations principally
from French authorities, though I shall occasionally allude to Italian writers
on the floods of the Tiber, of the Arno, and some other Italian streams
which much resemble those of the rivers of England and the United States.
b. Floods of the Ardèche.
The floods of 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 Ardèche, which has given its name to a department in France,
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 Ardèche itself is almost
everywhere fordable, even below the mouth of the Chassezac. But in
floods, the river has sometimes 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
1827, 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 at
literature of this branch of material improvement is exceedingly
voluminous. But the countries for which I write have no rivers like the Po,
no plains like those of Lombardy, and the dangers to which the inhabitants
of English and American river banks are exposed are more nearly analogous
to those that threaten the soil and population in the valleys and plains of
France, than to the perils and losses of the Lombard. The writings of the
Italian hydrographers, too, though rich in professional instruction, are less
accessible to foreigners and less adapted to popular use than those of
French engineers.[347] For these reasons I shall take my citations principally
from French authorities, though I shall occasionally allude to Italian writers
on the floods of the Tiber, of the Arno, and some other Italian streams
which much resemble those of the rivers of England and the United States.
b. Floods of the Ardèche.
The floods of 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 Ardèche, which has given its name to a department in France,
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 Ardèche itself is almost
everywhere fordable, even below the mouth of the Chassezac. But in
floods, the river has sometimes 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
1827, 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 at
Page 256
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 Ardèche 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 Cévennes, where it rises, the Ardèche 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
Ardèche, 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 Ardèche 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.[348] This is equal to
323,222,400 cubic yards per day. In a single day of flood, then, the
Ardèche, 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
contains 500,000 square miles of surface, or more than five hundred times
as much as that of the former.
The average annual precipitation in the basin of the Ardèche is not
greater than 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 Ardèche, and the
basins of many other tributaries of the Rhone exhibit meteorological
phenomena not less remarkable.[349] The inundation of the 10th September,
1857, was accompanied with a terrific hurricane, which passed along the
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 Ardèche 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 Cévennes, where it rises, the Ardèche 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
Ardèche, 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 Ardèche 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.[348] This is equal to
323,222,400 cubic yards per day. In a single day of flood, then, the
Ardèche, 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
contains 500,000 square miles of surface, or more than five hundred times
as much as that of the former.
The average annual precipitation in the basin of the Ardèche is not
greater than 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 Ardèche, and the
basins of many other tributaries of the Rhone exhibit meteorological
phenomena not less remarkable.[349] The inundation of the 10th September,
1857, was accompanied with a terrific hurricane, which passed along the
Page 257
eastern slope of the high grounds where the Ardèche and several other
western affluents of the Rhone take their rise. The wind tore up all the trees
in its path, and the rushing torrents bore their trunks down to the larger
streams, which again transported them to the Rhone in such rafts that one
might almost have crossed that river by stepping from trunk to trunk.[350]
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 height and violence of the inundations of most great rivers are
determined by the degree in which the floods of the different tributaries are
coincident in time. Were all the affluents of the Rhone to pour their highest
annual floods into its channel at once, 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 Ardèche, 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 Ardèche,
is not at all affected.[351]
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 in a former chapter, I
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 there 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
western affluents of the Rhone take their rise. The wind tore up all the trees
in its path, and the rushing torrents bore their trunks down to the larger
streams, which again transported them to the Rhone in such rafts that one
might almost have crossed that river by stepping from trunk to trunk.[350]
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 height and violence of the inundations of most great rivers are
determined by the degree in which the floods of the different tributaries are
coincident in time. Were all the affluents of the Rhone to pour their highest
annual floods into its channel at once, 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 Ardèche, 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 Ardèche,
is not at all affected.[351]
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 in a former chapter, I
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 there 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
Page 258
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.[352]
In the inundation of 1857, the Ardèche 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
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.
c. Crushing Force of Torrents.
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.[352]
In the inundation of 1857, the Ardèche 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
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.
c. Crushing Force of Torrents.
Page 259
There are few operations of nature where the effect seems more
disproportioned to the cause than in the 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 mouths, 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. The greatest depth of the basin of the Ardèche is seventy-five
miles, but most of its tributaries have a much shorter course. "These
affluents," says Mardigny, "hurl into the bed of the Ardèche enormous
blocks of rock, which this river, in its turn, bears onward, and grinds down,
at high water, so that its current rolls only gravel at its confluence with the
Rhone."[353]
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.[354] 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
disproportioned to the cause than in the 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 mouths, 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. The greatest depth of the basin of the Ardèche is seventy-five
miles, but most of its tributaries have a much shorter course. "These
affluents," says Mardigny, "hurl into the bed of the Ardèche enormous
blocks of rock, which this river, in its turn, bears onward, and grinds down,
at high water, so that its current rolls only gravel at its confluence with the
Rhone."[353]
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.[354] 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
Page 260
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. 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.[355]
d. 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 valleys of the Loire and its affluents,
about a million of acres, including many towns and villages, were laid
under water, and the amount of pecuniary damage was almost incalculable.
[356]
The 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.[357]
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
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
large blocks of stone are hurled out of the bed of the stream to the height of
twelve or thirteen feet. 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.[355]
d. 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 valleys of the Loire and its affluents,
about a million of acres, including many towns and villages, were laid
under water, and the amount of pecuniary damage was almost incalculable.
[356]
The 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.[357]
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
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
Page 261
centres, interrupted communication for days and even weeks together on
great lines of traffic and travel—thus severing as it were all Southwestern
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 a remedy.
e. Remedies against Inundations.
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. As we have already seen, opinion is still somewhat divided
on this subject, but the conservative action of the woods in this respect has
been generally recognized by the public of France, and the Government of
the empire has made this principle the basis of important 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 so 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
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 check the
violence, if not to prevent the recurrence, of destructive inundations. The
great lines of traffic and travel—thus severing as it were all Southwestern
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 a remedy.
e. Remedies against Inundations.
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. As we have already seen, opinion is still somewhat divided
on this subject, but the conservative action of the woods in this respect has
been generally recognized by the public of France, and the Government of
the empire has made this principle the basis of important 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 so 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
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 check the
violence, if not to prevent the recurrence, of destructive inundations. The
Page 262
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 will secure the creation of
new forest to the extent of about 250,000 acres, or one eleventh part of the
soil where the restoration of the forest is thought feasible and, at the same
time, specially important as a security against the evils ascribed in a great
measure to its destruction.
The provisions of the laws in question are preventive rather than
remedial; but some immediate effect may be expected to result from them,
particularly if they are accompanied with certain other measures, the
suggestion of which has been favorably received. The strong repugnance of
the mountaineers to the application of a system which deprives them of a
part of their pasturage—for the absolute exclusion of domestic animals is
indispensable to the maintenance of an existing forest and to the formation
of a new—is the most formidable obstacle to the execution of the laws of
1859-'60. It is proposed to compensate this loss by a cheap system of
irrigation of lower 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 terraces which, when once turfed over, are very
permanent. Experience is said to have demonstrated that this simple process
suffices to retain the water of rains, of snows, and of small springs and
rivulets, long enough for the irrigation of the soil, thus increasing its
product of herbage in a fivefold proportion, and that it partially checks the
too rapid flow of surface water into the valleys, and, consequently, in some
measure obviates one of the most prominent causes of inundations.[358] It is
evident that, if such results are produced by this method, its introduction
upon an extensive scale must also have the same climatic effects as other
systems of irrigation.
Whatever may be the ultimate advantages of reclothing a large extent of
the territory of France with wood, or of so shaping its surface as to prevent
the too rapid flow of water over it, the results to be obtained by such
processes can be realized in an adequate measure only after a long
succession of years. Other steps must be taken, both for the immediate
security of the lives and property of the present generation, and for the
prevention of yet greater and remoter evils which are inevitable unless
means to obviate them are found before it is forever too late. The frequent
the rate of 1,000,000 francs per year, in executing or aiding the replanting
of woods. It is computed that this appropriation will secure the creation of
new forest to the extent of about 250,000 acres, or one eleventh part of the
soil where the restoration of the forest is thought feasible and, at the same
time, specially important as a security against the evils ascribed in a great
measure to its destruction.
The provisions of the laws in question are preventive rather than
remedial; but some immediate effect may be expected to result from them,
particularly if they are accompanied with certain other measures, the
suggestion of which has been favorably received. The strong repugnance of
the mountaineers to the application of a system which deprives them of a
part of their pasturage—for the absolute exclusion of domestic animals is
indispensable to the maintenance of an existing forest and to the formation
of a new—is the most formidable obstacle to the execution of the laws of
1859-'60. It is proposed to compensate this loss by a cheap system of
irrigation of lower 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 terraces which, when once turfed over, are very
permanent. Experience is said to have demonstrated that this simple process
suffices to retain the water of rains, of snows, and of small springs and
rivulets, long enough for the irrigation of the soil, thus increasing its
product of herbage in a fivefold proportion, and that it partially checks the
too rapid flow of surface water into the valleys, and, consequently, in some
measure obviates one of the most prominent causes of inundations.[358] It is
evident that, if such results are produced by this method, its introduction
upon an extensive scale must also have the same climatic effects as other
systems of irrigation.
Whatever may be the ultimate advantages of reclothing a large extent of
the territory of France with wood, or of so shaping its surface as to prevent
the too rapid flow of water over it, the results to be obtained by such
processes can be realized in an adequate measure only after a long
succession of years. Other steps must be taken, both for the immediate
security of the lives and property of the present generation, and for the
prevention of yet greater and remoter evils which are inevitable unless
means to obviate them are found before it is forever too late. The frequent
Page 263
recurrence of inundations like those of 1856, for a single score of years, in
the basins of the Rhone and the Loire, with only the present securities
against them, would almost depopulate the valleys of those rivers, and
produce physical revolutions in them, which, like revolutions in the
political world, could never be made to "go backward."
Destructive inundations 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. Besides the utility of such
basins in preventing floods, the construction of them is recommended by
very strong considerations, such as the meteorological effects of increased
evaporable surface, the furnishing of a constant supply of water for
agricultural and mechanical purposes, and, finally, their value as ponds for
breeding and rearing fish, and, perhaps, for cultivating aquatic vegetables.
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 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;[359] 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 neighboring districts; and, lastly, the alleged impossibility
of constructing artificial basins sufficient in capacity to prevent, or in any
the basins of the Rhone and the Loire, with only the present securities
against them, would almost depopulate the valleys of those rivers, and
produce physical revolutions in them, which, like revolutions in the
political world, could never be made to "go backward."
Destructive inundations 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. Besides the utility of such
basins in preventing floods, the construction of them is recommended by
very strong considerations, such as the meteorological effects of increased
evaporable surface, the furnishing of a constant supply of water for
agricultural and mechanical purposes, and, finally, their value as ponds for
breeding and rearing fish, and, perhaps, for cultivating aquatic vegetables.
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 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;[359] 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 neighboring districts; and, lastly, the alleged impossibility
of constructing artificial basins sufficient in capacity to prevent, or in any
Page 264
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 recorded observations, the capacity of the necessary
reservoirs can be calculated. Let us take the case of the Ardèche. 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
Ardèche and its principal affluent, the Chassezac, 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 Chassezac, which is as large as the
Ardèche 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.
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 recorded observations, the capacity of the necessary
reservoirs can be calculated. Let us take the case of the Ardèche. 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
Ardèche and its principal affluent, the Chassezac, 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 Chassezac, which is as large as the
Ardèche 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.
Page 265
Another not less conclusive fact is that the valleys of all the upland
tributaries of the Ardèche 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
Ardèche 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
Ardèche 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 lower chains, and in this as in many other
instances, her processes may often be imitated with advantage. The validity
of the remaining objections to the system under discussion depends on the
topography, geology, and special climate of the regions where it is proposed
to establish such reservoirs. Many upland streams present numerous points
where none of these objections, except those of 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.
It is remarkable that nations which we, in the false 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
tributaries of the Ardèche 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
Ardèche 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
Ardèche 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 lower chains, and in this as in many other
instances, her processes may often be imitated with advantage. The validity
of the remaining objections to the system under discussion depends on the
topography, geology, and special climate of the regions where it is proposed
to establish such reservoirs. Many upland streams present numerous points
where none of these objections, except those of 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.
It is remarkable that nations which we, in the false 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
Page 266
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.
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.[360] 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
Torneå and the Calix rivers in Lapland communicate by the Tarando, and in
Westphalia, the Else, an arm of the Haase, falls into the Weser.
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 Ardèche
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.[361]
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
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.
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.[360] 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
Torneå and the Calix rivers in Lapland communicate by the Tarando, and in
Westphalia, the Else, an arm of the Haase, falls into the Weser.
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 Ardèche
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.[361]
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
Page 267
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 Moeris, 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 surplus waters. 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 some
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
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 forty years ago, and in both these cases a
great quantity of valuable land was rescued both from flood and from
insalubrity.
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 Moeris, 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 surplus waters. 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 some
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
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 forty years ago, and in both these cases a
great quantity of valuable land was rescued both from flood and from
insalubrity.
Page 268
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 threaten
serious danger.
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.
The principal means hitherto relied upon for defence against river
inundations has been the construction of dikes along the banks of the
streams, parallel to the channel and generally separated from each other by
a distance not much greater than the natural width of the bed.[362] 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 infiltration; but such ramparts are enormously
costly in original construction and maintenance, and, as we have already
seen, the filling up of the bed of the river in its lower course, by sand and
gravel, involves the necessity of occasionally incurring new expenditures in
increasing the height of the banks.[363] They are attended, too, with some
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 threaten
serious danger.
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.
The principal means hitherto relied upon for defence against river
inundations has been the construction of dikes along the banks of the
streams, parallel to the channel and generally separated from each other by
a distance not much greater than the natural width of the bed.[362] 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 infiltration; but such ramparts are enormously
costly in original construction and maintenance, and, as we have already
seen, the filling up of the bed of the river in its lower course, by sand and
gravel, involves the necessity of occasionally incurring new expenditures in
increasing the height of the banks.[363] They are attended, too, with some
Page 269
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 wide 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 through the breach is more
destructive than the natural flow of the highest inundation.[364]
For these reasons, many experienced engineers are of opinion that the
system of longitudinal dikes ought to be abandoned, or, where that cannot
be done without involving too great a sacrifice of existing constructions,
their elevation should be much reduced, so as to present no obstruction to
the lateral spread of extraordinary floods, and 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, and 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
argued, will diminish the violence of inundations by permitting the waters
to extend themselves over a greater surface and thus retarding the flow of
the river currents, and will, at the same time, secure the deposit of
fertilizing slime upon all the soil covered by the flood.
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.[365] 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. 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
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 wide 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 through the breach is more
destructive than the natural flow of the highest inundation.[364]
For these reasons, many experienced engineers are of opinion that the
system of longitudinal dikes ought to be abandoned, or, where that cannot
be done without involving too great a sacrifice of existing constructions,
their elevation should be much reduced, so as to present no obstruction to
the lateral spread of extraordinary floods, and 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, and 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
argued, will diminish the violence of inundations by permitting the waters
to extend themselves over a greater surface and thus retarding the flow of
the river currents, and will, at the same time, secure the deposit of
fertilizing slime upon all the soil covered by the flood.
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.[365] 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. 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
Page 270
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 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 sides of the stream, according to
circumstances, a line of cubical blocks of stone or pillars of masonry three
or four feet high and wide, and at 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 downward, 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.
[366]
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
natural depressions in which they flow;[367] 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.[368] The raising of the channels is
the current would be checked, and the quantity of transported pebbles and
gravel 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 sides of the stream, according to
circumstances, a line of cubical blocks of stone or pillars of masonry three
or four feet high and wide, and at 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 downward, 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.
[366]
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
natural depressions in which they flow;[367] 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.[368] The raising of the channels is
Page 271
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
marshes where, if left to herself, she would have accumulated inexhaustible
stores of the richest soil, and spread them out in plains above the reach of
ordinary floods.[369]
Consequences if the Nile had been Diked.
If a system of continuous lateral dikes, like those of the Po, had 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 the waters of the
annual inundation consequently 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
"wisdom of Egypt" taught her children 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 ever
bestowed upon a people.[370]
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
marshes where, if left to herself, she would have accumulated inexhaustible
stores of the richest soil, and spread them out in plains above the reach of
ordinary floods.[369]
Consequences if the Nile had been Diked.
If a system of continuous lateral dikes, like those of the Po, had 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 the waters of the
annual inundation consequently 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
"wisdom of Egypt" taught her children 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 ever
bestowed upon a people.[370]
Page 272
The valley of the Po has probably not been cultivated or inhabited so
long as that of the Nile, but embankments have been employed on its lower
course for at least two thousand years, and for many centuries they have
been connected in a continuous chain. I have pointed out in a former
chapter the effects produced on the geography of the Adriatic by the deposit
of river sediment in the sea at the mouths of the Po, the Adige, and the
Brenta. If these rivers had been left unconfined, like the Nile, and allowed
to spread their muddy waters at will, according to the laws of nature, the
slime they have carried to the coast would have been chiefly distributed
over the plains of Lombardy. Their banks 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 spared a reasonable proportion of the forests of the
Alps, and not attempted to control the natural drainage of the surface, the
Po 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.
[371]
The Nile is larger than all the rivers of Lombardy together,[372] it drains
a basin twenty 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.
We shall, therefore, not exceed the truth if we suppose the annually
inundated surface of Egypt to have been elevated, upon an average, ten feet,
within the last 5,000 years, or twice and a half the period during which the
history of the Po is known to us.[373]
We may estimate the present actually cultivated area of Egypt at about
5,500 square statute miles. As I have computed in a note on page 372, that
long as that of the Nile, but embankments have been employed on its lower
course for at least two thousand years, and for many centuries they have
been connected in a continuous chain. I have pointed out in a former
chapter the effects produced on the geography of the Adriatic by the deposit
of river sediment in the sea at the mouths of the Po, the Adige, and the
Brenta. If these rivers had been left unconfined, like the Nile, and allowed
to spread their muddy waters at will, according to the laws of nature, the
slime they have carried to the coast would have been chiefly distributed
over the plains of Lombardy. Their banks 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 spared a reasonable proportion of the forests of the
Alps, and not attempted to control the natural drainage of the surface, the
Po 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.
[371]
The Nile is larger than all the rivers of Lombardy together,[372] it drains
a basin twenty 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.
We shall, therefore, not exceed the truth if we suppose the annually
inundated surface of Egypt to have been elevated, upon an average, ten feet,
within the last 5,000 years, or twice and a half the period during which the
history of the Po is known to us.[373]
We may estimate the present actually cultivated area of Egypt at about
5,500 square statute miles. As I have computed in a note on page 372, that
Page 273
area is not more than half as extensive as 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
extent of soil it does not now reach. We may, then, adopt a mean between
the two quantities, and we shall probably come near the truth if we assume
the convenient number of 7,920 square statute miles as the average measure
of the inundated land during the historical period. Taking the deposit on this
surface at ten feet, the river sediment let fall on the soil of Egypt within the
last fifty centuries would amount to fifteen cubic miles.
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 been carried out to sea.[374]
This would have been a considerable quantity; for the Nile holds earth in
suspension even at low water, a much larger proportion during the flood,
and irrigation must have been carried on during the whole year. The precise
amount which would have been thus distributed over the soil is matter of
conjecture, but three cubic miles is certainly a liberal estimate. This would
leave twelve cubic miles as the quantity which embankments would have
compelled the Nile to transport to the Mediterranean 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.[375]
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
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
extent of soil it does not now reach. We may, then, adopt a mean between
the two quantities, and we shall probably come near the truth if we assume
the convenient number of 7,920 square statute miles as the average measure
of the inundated land during the historical period. Taking the deposit on this
surface at ten feet, the river sediment let fall on the soil of Egypt within the
last fifty centuries would amount to fifteen cubic miles.
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 been carried out to sea.[374]
This would have been a considerable quantity; for the Nile holds earth in
suspension even at low water, a much larger proportion during the flood,
and irrigation must have been carried on during the whole year. The precise
amount which would have been thus distributed over the soil is matter of
conjecture, but three cubic miles is certainly a liberal estimate. This would
leave twelve cubic miles as the quantity which embankments would have
compelled the Nile to transport to the Mediterranean 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.[375]
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
Page 274
prevented from spreading over the surface the sedimentary matter with
which they are charged. The western coast of Tuscany has advanced some
miles seaward 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 mart of Populonia has not an inhabitant; the coast
is almost absolutely depopulated, and the malarious fevers have extended
their ravages far into the interior.
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.[376]
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
which they are charged. The western coast of Tuscany has advanced some
miles seaward 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 mart of Populonia has not an inhabitant; the coast
is almost absolutely depopulated, and the malarious fevers have extended
their ravages far into the interior.
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.[376]
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
Page 275
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 success with which human guidance has made the
operations of nature herself available for the restoration of her disturbed
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 a very active cause of the development
of malarious influences.[377]
Improvements in the Val di Chiana.
For twenty miles or more after the remotest headwaters of the Arno
have united to form a considerable stream, this river flows southeastward to
the vicinity of Arezzo. It here sweeps round to the northwest, 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 southeastward 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
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 success with which human guidance has made the
operations of nature herself available for the restoration of her disturbed
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 a very active cause of the development
of malarious influences.[377]
Improvements in the Val di Chiana.
For twenty miles or more after the remotest headwaters of the Arno
have united to form a considerable stream, this river flows southeastward to
the vicinity of Arezzo. It here sweeps round to the northwest, 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 southeastward 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
Page 276
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.[378]
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. If it were
elevated to what was evidently its original height, the current of the Arno
would be so much above that of the Paglia as to allow of a regular flow
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 and of the
Arno itself, 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
principal drainage of the Val di Chiana appears to have been in a
southeastwardly direction until within a comparatively recent period.
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.[378]
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. If it were
elevated to what was evidently its original height, the current of the Arno
would be so much above that of the Paglia as to allow of a regular flow
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 and of the
Arno itself, 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
principal drainage of the Val di Chiana appears to have been in a
southeastwardly direction until within a comparatively recent period.
Page 277
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 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 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 project.[379] The fears of the
Roman Government for the security of the valley of the Tiber had induced it
to construct barriers across that part of the channel which lay 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.[380]
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
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 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 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 project.[379] The fears of the
Roman Government for the security of the valley of the Tiber had induced it
to construct barriers across that part of the channel which lay 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.[380]
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
Page 278
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 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.[381] 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 halfway 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 mean time 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
banks of the Arno to greater danger from inundations by draining the Val di
Chiana 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
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 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.[381] 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 halfway 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 mean time 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
banks of the Arno to greater danger from inundations by draining the Val di
Chiana 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
Page 279
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 certain
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
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
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 certain
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
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
Page 280
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.
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.[382]
Improvements in the Tuscan Maremme.
In the improvements of the Tuscan Maremma, more formidable
difficulties have been encountered. The territory to be reclaimed was more
extensive; the salubrious places of retreat for laborers and inspectors were
more remote; the courses of the rivers to be controlled were longer and their
natural inclination less rapid; some of them, rising in wooded regions,
transported comparatively little earthy matter,[383] and above all,
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 joint 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
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
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.
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.[382]
Improvements in the Tuscan Maremme.
In the improvements of the Tuscan Maremma, more formidable
difficulties have been encountered. The territory to be reclaimed was more
extensive; the salubrious places of retreat for laborers and inspectors were
more remote; the courses of the rivers to be controlled were longer and their
natural inclination less rapid; some of them, rising in wooded regions,
transported comparatively little earthy matter,[383] and above all,
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 joint 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
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
Page 281
the principle stated in the text, in Frisi, Del modo di regolare i Fiumi e i
Torrenti, libro iii, capit. i. 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.
[384]
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,[385]
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 Maremme, 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.[386] In accordance with these views, settlers were invited
from various parts of Italy, from Greece, and, after the accession of the
Torrenti, libro iii, capit. i. 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.
[384]
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,[385]
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 Maremme, 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.[386] In accordance with these views, settlers were invited
from various parts of Italy, from Greece, and, after the accession of the
Page 282
Lorraine princes, from that country also, and colonized in the Maremme. 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 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 maritima, 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,
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
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 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 maritima, 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,
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
Page 283
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, and are
now in successful progress.
I have spoken, with some detail, of the improvements in the Val di
Chiana and 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.[387]
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 deleterious character, which
would infallibly have taken place if they had not been arrested by the
improvements in question. 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 detained the waters of the wet season until they could be
gradually drawn off into the Paglia. They consequently deposited most of
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, and are
now in successful progress.
I have spoken, with some detail, of the improvements in the Val di
Chiana and 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.[387]
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 deleterious character, which
would infallibly have taken place if they had not been arrested by the
improvements in question. 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 detained the waters of the wet season until they could be
gradually drawn off into the Paglia. They consequently deposited most of
Page 284
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 mètres and nine tenths (twelve feet and nine inches) per annum.[388]
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 sediment washed into the marshes of the Maremme 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, 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
afterward at or near the outlets of the rivers which produced them.
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 mètres and nine tenths (twelve feet and nine inches) per annum.[388]
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 sediment washed into the marshes of the Maremme 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, 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
afterward at or near the outlets of the rivers which produced them.
Page 285
Obstruction of River Mouths.
The mouths of a large proportion of the streams known to ancient
internal navigation are already blocked up by sandbars 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 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,
in a less 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 these 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.[389] 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 increases the erosion from its surface; his arrangements for
confining the lateral spread of the water in floods compel the rivers to
The mouths of a large proportion of the streams known to ancient
internal navigation are already blocked up by sandbars 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 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,
in a less 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 these 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.[389] 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 increases the erosion from its surface; his arrangements for
confining the lateral spread of the water in floods compel the rivers to
Page 286
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
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, until it finds a resting place
in the northeastern angle of the Mediterranean.[390] 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 maritime channels
which lead to the city built by Alexander near the mouth of the Nile, and to
fill up the harbors made famous by Phenician commerce.
Subterranean Waters.
upper course; and, consequently, the sediment they deposit at their outlets is
not only much larger in quantity, but composed of heavier materials, which
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, until it finds a resting place
in the northeastern angle of the Mediterranean.[390] 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 maritime channels
which lead to the city built by Alexander near the mouth of the Nile, and to
fill up the harbors made famous by Phenician commerce.
Subterranean Waters.
Page 287
I have frequently alluded to a branch of 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.[391] 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[392] or of the ocean, and some remains, though even here not in
forever motionless repose, to fill deep cavities and underground channels.
[393]
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
downward, 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
the sea by that river, "so that five sixths remained for evaporation and
consumption by the organic world."[394]
Lieutenant Maury—whose scientific reputation, though fallen, has not
quite sunk to the level of his patriotism—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."[395] 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.
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.[391] 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[392] or of the ocean, and some remains, though even here not in
forever motionless repose, to fill deep cavities and underground channels.
[393]
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
downward, 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
the sea by that river, "so that five sixths remained for evaporation and
consumption by the organic world."[394]
Lieutenant Maury—whose scientific reputation, though fallen, has not
quite sunk to the level of his patriotism—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."[395] 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.
Page 288
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. The distribution of these waters has been minutely studied with
reference to a great number of localities, and though the actual mode of
their vertical and horizontal transmission is still involved in much doubt,
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 Abbé Paramelle—a French 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, the highest scientific
authorities in Europe have testified to the great practical value of his
methods, and the almost infallible certainty of his predictions.[396]
Babinet quotes a French proverb, "Summer rain wets nothing," and
explains it as meaning that the water of such rains is "almost totally taken
up by evaporation." "The rains of summer," he adds, "however abundant
they may be, do not penetrate the soil to a greater depth than 15 or 20
centimètres. In summer the evaporating power of the heat is five or six
times as great as in winter, and this power is exerted by an atmosphere
capable of containing five times as much vapor as in winter." "A stratum of
snow which prevents evaporation [from the soil] causes almost all the water
that composes it to filter down into the earth, and form a reserve for springs,
wells, and rivers which could not be supplied by any amount of summer
rain." "This latter—useful, indeed like dew, to vegetation—does not
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. The distribution of these waters has been minutely studied with
reference to a great number of localities, and though the actual mode of
their vertical and horizontal transmission is still involved in much doubt,
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 Abbé Paramelle—a French 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, the highest scientific
authorities in Europe have testified to the great practical value of his
methods, and the almost infallible certainty of his predictions.[396]
Babinet quotes a French proverb, "Summer rain wets nothing," and
explains it as meaning that the water of such rains is "almost totally taken
up by evaporation." "The rains of summer," he adds, "however abundant
they may be, do not penetrate the soil to a greater depth than 15 or 20
centimètres. In summer the evaporating power of the heat is five or six
times as great as in winter, and this power is exerted by an atmosphere
capable of containing five times as much vapor as in winter." "A stratum of
snow which prevents evaporation [from the soil] causes almost all the water
that composes it to filter down into the earth, and form a reserve for springs,
wells, and rivers which could not be supplied by any amount of summer
rain." "This latter—useful, indeed like dew, to vegetation—does not
Page 289
penetrate the soil and accumulate a store to feed springs and to be brought
up by them to the open air."[397] This conclusion, however applicable it may
be to the climate and soil of France, is too broadly stated to be accepted as a
general truth, and in countries where the precipitation is small in the winter
months, familiar observation shows that the quantity of water yielded by
deep wells and natural springs depends not less on the rains of summer than
on those of the rest of the year, and, consequently, that much of the
precipitation of that season must find its way to strata too deep to lose water
by evaporation.
The supply of subterranean reservoirs and currents, as well as of
springs, is undoubtedly derived chiefly from infiltration, and hence it must
be affected by all changes of the natural surface that accelerate or retard the
drainage of the soil, or that either promote or obstruct evaporation from it. It
has sufficiently appeared from what has gone before, that the spontaneous
drainage of cleared ground is more rapid than that of the forest, and
consequently, that the felling of the woods, as well as the draining of
swamps, deprives the subterranean waters of accessions which would
otherwise be conveyed to them by infiltration. The same effect is produced
by artificial contrivances for drying the soil either by open ditches or by
underground pipes or channels, and in proportion as the sphere of these
operations is extended, the effect of them cannot fail to make itself more
and more sensibly felt in the diminished supply of water furnished by wells
and running springs.[398]
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
up by them to the open air."[397] This conclusion, however applicable it may
be to the climate and soil of France, is too broadly stated to be accepted as a
general truth, and in countries where the precipitation is small in the winter
months, familiar observation shows that the quantity of water yielded by
deep wells and natural springs depends not less on the rains of summer than
on those of the rest of the year, and, consequently, that much of the
precipitation of that season must find its way to strata too deep to lose water
by evaporation.
The supply of subterranean reservoirs and currents, as well as of
springs, is undoubtedly derived chiefly from infiltration, and hence it must
be affected by all changes of the natural surface that accelerate or retard the
drainage of the soil, or that either promote or obstruct evaporation from it. It
has sufficiently appeared from what has gone before, that the spontaneous
drainage of cleared ground is more rapid than that of the forest, and
consequently, that the felling of the woods, as well as the draining of
swamps, deprives the subterranean waters of accessions which would
otherwise be conveyed to them by infiltration. The same effect is produced
by artificial contrivances for drying the soil either by open ditches or by
underground pipes or channels, and in proportion as the sphere of these
operations is extended, the effect of them cannot fail to make itself more
and more sensibly felt in the diminished supply of water furnished by wells
and running springs.[398]
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
Page 290
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.
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 subterranean 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 tree may be made
perfectly impervious to water, by flag stones and cement, for a distance
greater than 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 grow well 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 above, 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.
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.[399]
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
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.
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 subterranean 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 tree may be made
perfectly impervious to water, by flag stones and cement, for a distance
greater than 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 grow well 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 above, 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.
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.[399]
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 291
seeds, leaves, and even living fish, which must have been carried down
through channels large enough to admit a considerable stream. But in
general, the sheets 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.[400] 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.
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;[401] 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, 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 have bored artesian wells
down to this reservoir, to obtain water for domestic use and irrigation, but I
do not find such wells described by any trustworthy traveller, 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
through channels large enough to admit a considerable stream. But in
general, the sheets 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.[400] 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.
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;[401] 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, 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 have bored artesian wells
down to this reservoir, to obtain water for domestic use and irrigation, but I
do not find such wells described by any trustworthy traveller, 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
Page 292
purpose; for the water rises to the surface and flows over it as from a spring.
[402]
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.[403] 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.[404]
The most sanguine believer in indefinite human progress hardly expects
that man's cunning will accomplish the universal fufilment 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
from the Libyan sky, and that the showers which are now wasted on the sea,
[402]
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.[403] 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.[404]
The most sanguine believer in indefinite human progress hardly expects
that man's cunning will accomplish the universal fufilment 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
from the Libyan sky, and that the showers which are now wasted on the sea,
Page 293
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 Lardarello 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
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."[405] 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
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 Lardarello 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
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."[405] 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
Page 294
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."[406]
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
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."[407] 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
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."[406]
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
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."[407] 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
Page 295
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.
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 be discharged in a constant flow or at intervals as convenience may
dictate.[408]
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, if
judiciously expended in a combination of both methods of improvement,
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.
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 be discharged in a constant flow or at intervals as convenience may
dictate.[408]
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, if
judiciously expended in a combination of both methods of improvement,
Page 296
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.
amelioration of climate, a renovated fertility of soil, and a general physical
improvement, which might almost be characterized as a new creation.
Page 297
CHAPTER V
THE SANDS.
ORIGIN OF SAND—SAND NOW CARRIED DOWN TO THE SEA—THE SANDS OF EGYPT
AND THE ADJACENT DESERT——THE SUEZ CANAL——THE SANDS OF EGYPT—
COAST DUNES AND SAND PLAINS—SAND BANKS—DUNES ON COAST OF AMERICA—
DUNES OF WESTERN EUROPE—FORMATION OF DUNES—CHARACTER OF DUNE SAND
—INTERIOR STRUCTURE OF DUNES—FORM OF DUNES—GEOLOGICAL IMPORTANCE
OF DUNES—INLAND DUNES—AGE, CHARACTER, AND PERMANENCE OF DUNES—USE
OF DUNES AS BARRIER AGAINST THE SEA—ENCROACHMENTS OF THE SEA—THE
LIIMFJORD—ENCROACHMENTS OF THE SEA—DRIFTING OF DUNE SANDS—DUNES OF
GASCONY—DUNES OF DENMARK—DUNES OF PRUSSIA—ARTIFICIAL FORMATION OF
DUNES—TREES SUITABLE FOR DUNE PLANTATIONS—EXTENT OF DUNES IN EUROPE
—DUNE VINEYARDS OF CAPE BRETON—REMOVAL OF DUNES—INLAND SAND PLAINS
—THE LANDES OF GASCONY—THE BELGIAN CAMPINE—SANDS AND STEPPES OF
EASTERN EUROPE—ADVANTAGES OF RECLAIMING DUNES—GOVERNMENT WORKS
OF IMPROVEMENT.
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
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,
felspar, 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
THE SANDS.
ORIGIN OF SAND—SAND NOW CARRIED DOWN TO THE SEA—THE SANDS OF EGYPT
AND THE ADJACENT DESERT——THE SUEZ CANAL——THE SANDS OF EGYPT—
COAST DUNES AND SAND PLAINS—SAND BANKS—DUNES ON COAST OF AMERICA—
DUNES OF WESTERN EUROPE—FORMATION OF DUNES—CHARACTER OF DUNE SAND
—INTERIOR STRUCTURE OF DUNES—FORM OF DUNES—GEOLOGICAL IMPORTANCE
OF DUNES—INLAND DUNES—AGE, CHARACTER, AND PERMANENCE OF DUNES—USE
OF DUNES AS BARRIER AGAINST THE SEA—ENCROACHMENTS OF THE SEA—THE
LIIMFJORD—ENCROACHMENTS OF THE SEA—DRIFTING OF DUNE SANDS—DUNES OF
GASCONY—DUNES OF DENMARK—DUNES OF PRUSSIA—ARTIFICIAL FORMATION OF
DUNES—TREES SUITABLE FOR DUNE PLANTATIONS—EXTENT OF DUNES IN EUROPE
—DUNE VINEYARDS OF CAPE BRETON—REMOVAL OF DUNES—INLAND SAND PLAINS
—THE LANDES OF GASCONY—THE BELGIAN CAMPINE—SANDS AND STEPPES OF
EASTERN EUROPE—ADVANTAGES OF RECLAIMING DUNES—GOVERNMENT WORKS
OF IMPROVEMENT.
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
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,
felspar, 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
Page 298
unmixed, when they had been decomposed and had entered into new
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.[409] In cases
where rock has been reduced to sandy fragments by heat, or by obscure
chemical and other molecular forces, the sandbeds 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 deserts of Persia, and of that of Gobi, are
commonly 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; 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 much younger 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 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 sandbanks at the outlet of
large streams are of tidal, not of fluviatile origin, or, in lakes and tideless
seas, a result of the concurrent action of waves and of wind.
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.[409] In cases
where rock has been reduced to sandy fragments by heat, or by obscure
chemical and other molecular forces, the sandbeds 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 deserts of Persia, and of that of Gobi, are
commonly 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; 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 much younger 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 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 sandbanks at the outlet of
large streams are of tidal, not of fluviatile origin, or, in lakes and tideless
seas, a result of the concurrent action of waves and of wind.
Page 299
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.[410] His general conclusion is, that the
rivers of the Netherlands "move sand only by a very slow displacement of
sandbanks, 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 Mediterranean at the
mouths of the Nile and on the Barbary coast.[411]
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.[412] 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 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.[413] 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.
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.[410] His general conclusion is, that the
rivers of the Netherlands "move sand only by a very slow displacement of
sandbanks, 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 Mediterranean at the
mouths of the Nile and on the Barbary coast.[411]
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.[412] 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 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.[413] 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.
Page 300
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,[414]
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 sandbanks and dunes upon the southern shores of the
Mediterranean will cease at last for want of material.[415]
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. 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. 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
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,[414]
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 sandbanks and dunes upon the southern shores of the
Mediterranean will cease at last for want of material.[415]
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. 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. 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
Page 301
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.[416] 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" must be gratified accordingly.[417]
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.[418] 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.[419]
The Suez Canal.
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.[416] 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" must be gratified accordingly.[417]
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.[418] 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.[419]
The Suez Canal.
Page 302
These considerations apply, with equal force, to the supposed danger of
the obstruction of the Suez Canal by the drifting of the desert sands. The
winds across the isthmus are almost uniformly from the north, and they
swept it 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 toward the line of the canal, would easily be arrested by plantations
or other simple methods, or removed by dredging. The real dangers and
difficulties of this magnificent enterprise—and they are great—consist 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 at the northern, by the action of
the winds. 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.
Sands of Egypt.
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
promoted. Thus the winds and the water, moving in contrary directions, join
in producing a common effect.
the obstruction of the Suez Canal by the drifting of the desert sands. The
winds across the isthmus are almost uniformly from the north, and they
swept it 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 toward the line of the canal, would easily be arrested by plantations
or other simple methods, or removed by dredging. The real dangers and
difficulties of this magnificent enterprise—and they are great—consist 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 at the northern, by the action of
the winds. 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.
Sands of Egypt.
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
promoted. Thus the winds and the water, moving in contrary directions, join
in producing a common effect.
Page 303
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 the true 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 primarily from the desert, but
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 sea; 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 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.
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 the true 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 primarily from the desert, but
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 sea; 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 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.
Page 304
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 the 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.[420]
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 knolls and 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, sometimes to have been drifted from the sea
coast, 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,[421] 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 certain
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
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 the 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.[420]
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 knolls and 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, sometimes to have been drifted from the sea
coast, 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,[421] 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 certain
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
Page 305
which, in most cases, thinly clothes and at the same time confines it, is
broken.
Human industry has not only fixed the flying dunes, 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 accumulation 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 physical geography. 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.
Coast Dunes.
Coast dunes are oblong ridges or round hillocks, formed by the action of
the wind upon sands thrown up by the waves on the beach 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.[422] 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
broken.
Human industry has not only fixed the flying dunes, 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 accumulation 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 physical geography. 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.
Coast Dunes.
Coast dunes are oblong ridges or round hillocks, formed by the action of
the wind upon sands thrown up by the waves on the beach 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.[422] 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
Page 306
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 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 dunes on the Russian
and Prussian coasts of the Baltic, and at the mouths of the Nile 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 southeastern extremity of Lake
Michigan.[423] 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 northwest 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 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
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 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 dunes on the Russian
and Prussian coasts of the Baltic, and at the mouths of the Nile 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 southeastern extremity of Lake
Michigan.[423] 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 northwest 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 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
Page 307
gravel is not thrown out by the waves, but rolls backward and forward 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."[424] 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 seaward; and their form differs from
that of dunes only 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 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 landward,
and they compose the magazine from which the material for the dunes is
derived. 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
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."[424] 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 seaward; and their form differs from
that of dunes only 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 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 landward,
and they compose the magazine from which the material for the dunes is
derived. 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
Page 308
the phenomena that characterize the structure of the dunes, observation has
proved that it is nearly identical with that of submerged sand banks. 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.
Dunes on the Coast of America.
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
proved that it is nearly identical with that of submerged sand banks. 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.
Dunes on the Coast of America.
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
Page 309
adjacent duchies, in Western Prussia, in the Netherlands, and in France; and
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.[425]
Formation of Dunes.
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
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, vortical, 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.
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.[425]
Formation of Dunes.
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
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, vortical, 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.
Page 310
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
Southwestern 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 seaward, 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.[426] 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 some times 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 calcareous 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.
Character of Dune Sand.
secure shores, because they are undermined and carried off before they have
time to reach their greatest dimensions. Hence, while at sheltered points in
Southwestern 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 seaward, 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.[426] 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 some times 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 calcareous 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.
Character of Dune Sand.
Page 311
"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.[427] 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."[428]
J. G. Kohl has some poetical thoughts upon the origin and character of
the dune sands, which are worth quoting:
"The sand was composed of pure transparent quartz. I could not observe
this sand without the greatest admiration. If it is the product of the waves,
breaking and crushing flints and fragments of quartz against each other, it is
a result which could be brought about only in the course of countless ages.
We need not lift ourselves to the stars, to their incalculable magnitudes and
distances and numbers, in order to feel the giddiness of astonishment. Here,
upon earth, in the simple sand, we find miracle enough. Think of the
number of sand grains contained in a single dune, then of all the dunes upon
this widely extended coast—not to speak of the innumerable grains in the
Arabian, African, and Prussian deserts—this, of itself, is sufficient to
overwhelm a thoughtful fancy. How long, how many times must the waves
have risen and sunk in order to reduce these vast heaps to powder!
"During the whole time I spent on this coast, I had always some sand in
my fingers, was rubbing and rolling it about, examining it on all sides,
holding a little shining grain on the tip of my finger, and thinking to myself
how, in its corners, its angles, its whole configuration, it might very
probably have a history longer than that of the old German nation—
possibly longer than that of the human race. Where was the original quartz
crystal, of which this is a fragment, first formed? To what was it once fixed?
What power broke it loose? How was it beaten smaller and ever smaller by
more or less colored by iron, and often mingled with fragments of shells,
small indeed, but still visible to the naked eye.[427] 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."[428]
J. G. Kohl has some poetical thoughts upon the origin and character of
the dune sands, which are worth quoting:
"The sand was composed of pure transparent quartz. I could not observe
this sand without the greatest admiration. If it is the product of the waves,
breaking and crushing flints and fragments of quartz against each other, it is
a result which could be brought about only in the course of countless ages.
We need not lift ourselves to the stars, to their incalculable magnitudes and
distances and numbers, in order to feel the giddiness of astonishment. Here,
upon earth, in the simple sand, we find miracle enough. Think of the
number of sand grains contained in a single dune, then of all the dunes upon
this widely extended coast—not to speak of the innumerable grains in the
Arabian, African, and Prussian deserts—this, of itself, is sufficient to
overwhelm a thoughtful fancy. How long, how many times must the waves
have risen and sunk in order to reduce these vast heaps to powder!
"During the whole time I spent on this coast, I had always some sand in
my fingers, was rubbing and rolling it about, examining it on all sides,
holding a little shining grain on the tip of my finger, and thinking to myself
how, in its corners, its angles, its whole configuration, it might very
probably have a history longer than that of the old German nation—
possibly longer than that of the human race. Where was the original quartz
crystal, of which this is a fragment, first formed? To what was it once fixed?
What power broke it loose? How was it beaten smaller and ever smaller by
Page 312
the waves? They tossed it, for æons, to and fro upon the beach, rolled it up
and down, forced it to make thousands and thousands of daily voyages for
millions and millions of days. Then the wind bore it away, and used it in
building up a dune; there it lay for centuries, packed in with its fellows,
protecting the marshes and cherished by the inhabitants, till, seized again by
the pursuing sea, it fell once more into the water, there to begin the endless
dance anew—and again to be swept away by the wind—and again to find
rest in the dunes, a protection and a blessing to the coast. There is
something mysterious about such a grain of sand, and at last I went so far as
to fancy a little immortal spark linked with each one, presiding over its
destiny, and sharing its vicissitudes. Could we arm our eyes with a
microscope, and then dive, like a sparling, into one of these dunes, the pile,
which is in fact only a heap of countless little crystal blocks, would strike us
as the most marvellous building upon earth. The sunbeams would pass, with
illuminating power, through all these little crystalline bodies. We should see
how every sand grain is formed, by what multifarious little facets it is
bounded, we should even discover that it is itself composed of many
distinct particles."[429]
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.[430]
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 wind as well as of water. The origin and peculiar character
of these layers are due to a variety of causes. A southwest wind and current
may deposit upon a dune a stratum of a given color and mineral
composition, and this may be succeeded by a northwest wind and current,
bringing with them particles of a different hue, constitution, and origin.
and down, forced it to make thousands and thousands of daily voyages for
millions and millions of days. Then the wind bore it away, and used it in
building up a dune; there it lay for centuries, packed in with its fellows,
protecting the marshes and cherished by the inhabitants, till, seized again by
the pursuing sea, it fell once more into the water, there to begin the endless
dance anew—and again to be swept away by the wind—and again to find
rest in the dunes, a protection and a blessing to the coast. There is
something mysterious about such a grain of sand, and at last I went so far as
to fancy a little immortal spark linked with each one, presiding over its
destiny, and sharing its vicissitudes. Could we arm our eyes with a
microscope, and then dive, like a sparling, into one of these dunes, the pile,
which is in fact only a heap of countless little crystal blocks, would strike us
as the most marvellous building upon earth. The sunbeams would pass, with
illuminating power, through all these little crystalline bodies. We should see
how every sand grain is formed, by what multifarious little facets it is
bounded, we should even discover that it is itself composed of many
distinct particles."[429]
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.[430]
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 wind as well as of water. The origin and peculiar character
of these layers are due to a variety of causes. A southwest wind and current
may deposit upon a dune a stratum of a given color and mineral
composition, and this may be succeeded by a northwest wind and current,
bringing with them particles of a different hue, constitution, and origin.
Page 313
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 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.[431] Still
another cause of 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.
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.
Form of Dunes.
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.
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 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.[431] Still
another cause of 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.
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.
Form of Dunes.
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.
Page 314
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 landward, 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° with the horizon, while the more exposed and irregular weather side lies
at an inclination of from 5° to 10°. 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.
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 southwest and west, the prevailing
winds blowing from the northeast 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.[432] There is nothing violently improbable in the
supposition that they may have been first thrown up by the Mediterranean
on its Libyan coast, and thence blown south and west over the vast space
they now cover. But whatever has been their source and movement, 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
while the sand on the lee side is found to be disposed in more regular beds,
inclining landward, 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° with the horizon, while the more exposed and irregular weather side lies
at an inclination of from 5° to 10°. 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.
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 southwest and west, the prevailing
winds blowing from the northeast 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.[432] There is nothing violently improbable in the
supposition that they may have been first thrown up by the Mediterranean
on its Libyan coast, and thence blown south and west over the vast space
they now cover. But whatever has been their source and movement, 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
Page 315
satisfactory evidence as to their origin, their starting point, and the course
by which they have wandered so far from the sea.[433]
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 recemented 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 would be difficulty in distinguishing them;[434] 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.[435]
Inland Dunes.
I have met with some observations indicating a structural difference
between interior and coast dunes, which might perhaps be recognized in the
sandstones formed from these two species of sand hills respectively. In the
great American desert between the Andes and the Pacific, Meyen found
sand heaps of a perfect falciform shape.[436] They were from seven to
fifteen 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° or 80°, and their surfaces were rippled. No smaller
dunes were observed, nor any in the process of formation. The concave side
uniformly faced the northwest, except toward 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.
by which they have wandered so far from the sea.[433]
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 recemented 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 would be difficulty in distinguishing them;[434] 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.[435]
Inland Dunes.
I have met with some observations indicating a structural difference
between interior and coast dunes, which might perhaps be recognized in the
sandstones formed from these two species of sand hills respectively. In the
great American desert between the Andes and the Pacific, Meyen found
sand heaps of a perfect falciform shape.[436] They were from seven to
fifteen 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° or 80°, and their surfaces were rippled. No smaller
dunes were observed, nor any in the process of formation. The concave side
uniformly faced the northwest, except toward 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.
Page 316
Pöppig ascribes a falciform shape to the movable, a conical to the fixed
dunes, or medanos, of the same desert. "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 downward. 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 afterward 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.
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 southeast wind, which constantly
alternates with the wind from the south."[437]
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 these 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.[438]
dunes, or medanos, of the same desert. "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 downward. 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 afterward 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.
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 southeast wind, which constantly
alternates with the wind from the south."[437]
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 these 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.[438]
Page 317
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.[439] 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 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 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 these processes were abandoned.[440]
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
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.[439] 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 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 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 these processes were abandoned.[440]
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
Page 318
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.[441] 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.[442] 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.[443]
Nature, as she builds up dunes for the protection of the sea shore,
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.
Before the occupation of the coasts by civilized and therefore
destructive 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,[444] and to have spontaneously clothed
themselves with a dense growth of the various plants, grasses, shrubs, 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.[441] 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.[442] 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.[443]
Nature, as she builds up dunes for the protection of the sea shore,
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.
Before the occupation of the coasts by civilized and therefore
destructive 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,[444] and to have spontaneously clothed
themselves with a dense growth of the various plants, grasses, shrubs, and
Page 319
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, wherever the value of
land is considerable and the population dense. In the main, 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, upon
the whole, a protective and beneficial agent, and their maintenance is an
object of solicitude with the governments and people of the shores they
protect.[445]
Use of Dunes as a Barrier against the Sea.
Although the sea throws up large quantities of sand on flat lee-shores,
there are, as we have seen, 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 eastward. 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 westward. 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 generally composed of particles finer, lighter, and more
transportable by water than the sea sand. While, therefore, the billows
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, wherever the value of
land is considerable and the population dense. In the main, 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, upon
the whole, a protective and beneficial agent, and their maintenance is an
object of solicitude with the governments and people of the shores they
protect.[445]
Use of Dunes as a Barrier against the Sea.
Although the sea throws up large quantities of sand on flat lee-shores,
there are, as we have seen, 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 eastward. 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 westward. 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 generally composed of particles finer, lighter, and more
transportable by water than the sea sand. While, therefore, the billows
Page 320
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.[446] 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.
Encroachments of the Sea.
The eastward progress of the sea on the Danish and Netherlandish coast,
and on certain shores of the Atlantic, 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 he 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
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.[446] 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.
Encroachments of the Sea.
The eastward progress of the sea on the Danish and Netherlandish coast,
and on certain shores of the Atlantic, 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 he 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
Page 321
Jutland, the loss is smaller, but the sea is encroaching generally upon the
whole line of the coast.[447]
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 effects were produced very similar to those resulting from the
formation of the new channel in 1825, which still remains open.[448] 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.
whole line of the coast.[447]
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 effects were produced very similar to those resulting from the
formation of the new channel in 1825, which still remains open.[448] 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.
Page 322
"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
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."[449]
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
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
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."[449]
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
Page 323
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.[450]
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;[451] 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
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 Gironde, retreated one hundred and
eighty mètres, or about 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 above six hundred feet. All the buildings at the
extremity of the peninsula have been taken down and rebuilt farther
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.[450]
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;[451] 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
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 Gironde, retreated one hundred and
eighty mètres, or about 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 above six hundred feet. All the buildings at the
extremity of the peninsula have been taken down and rebuilt farther
Page 324
landward, 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 twenty years the scene of one of the most
obstinately contested struggles between man and the ocean recorded in the
annals of modern engineering.
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.[452]
Drifting of Dune Sands.
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 inward; 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.
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 sea attacked the base of the peninsula also, and the Point de Grave and
the adjacent coasts have been for twenty years the scene of one of the most
obstinately contested struggles between man and the ocean recorded in the
annals of modern engineering.
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.[452]
Drifting of Dune Sands.
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 inward; 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.
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.
Page 325
The burrowing of conies in the dunes is, in this way, not unfrequently 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.[453]
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 mean time, 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.
Dunes of Gascony.
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 three hundred and seventy-five square miles.
When not fixed by vegetable growths, they advance eastward at a mean rate
of about one rod, or sixteen and a half feet, a year. We 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 eastern boundary, 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
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.[453]
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 mean time, 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.
Dunes of Gascony.
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 three hundred and seventy-five square miles.
When not fixed by vegetable growths, they advance eastward at a mean rate
of about one rod, or sixteen and a half feet, a year. We 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 eastern boundary, 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
Page 326
fertile.[454] 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.[455]
The Dunes of Denmark and Prussia.
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. The general rate of eastward movement of the drifting dunes
is from three to twenty-four feet per annum. If we adopt the mean of
thirteen feet and a half for the annual motion, the 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.[456]
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
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.[455]
The Dunes of Denmark and Prussia.
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. The general rate of eastward movement of the drifting dunes
is from three to twenty-four feet per annum. If we adopt the mean of
thirteen feet and a half for the annual motion, the 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.[456]
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
Page 327
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.
Artificial Formation of Dunes.
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 farther. This familiar observation has taught the
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
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.
Artificial Formation of Dunes.
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 farther. This familiar observation has taught the
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
Page 328
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.[457]
Protection of Dunes.
The dunes of Holland are sometimes protected from the dashing of the
waves by a revêtement of stone, or by piles; and the lateral high-water
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.[458] 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, Dünenhalm, Sandschilf, or Hügelrohr in German, gourbet in
French, and marram in English—are exclusively confined to sandy soils,
and thrive well only in a saline atmosphere.[459] 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 nourishing 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,
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.[457]
Protection of Dunes.
The dunes of Holland are sometimes protected from the dashing of the
waves by a revêtement of stone, or by piles; and the lateral high-water
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.[458] 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, Dünenhalm, Sandschilf, or Hügelrohr in German, gourbet in
French, and marram in English—are exclusively confined to sandy soils,
and thrive well only in a saline atmosphere.[459] 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 nourishing 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,
Page 329
by growth and 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;[460] 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 it 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.[461]
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 these vegetables.[462] 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.[463] During this latter period, Brémontier, 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.
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;[460] 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 it 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.[461]
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 these vegetables.[462] 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.[463] During this latter period, Brémontier, 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.
Page 330
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.
In France, the operations for fixing and reclaiming the dunes—which
began under the direction of Brémontier 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
Brémontier and perfected by his successors, is about 100,000 acres.[464]
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 Sören Björn, 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
preliminary operations had been carried on for subduing the dunes on the
west coast.[465]
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.
In France, the operations for fixing and reclaiming the dunes—which
began under the direction of Brémontier 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
Brémontier and perfected by his successors, is about 100,000 acres.[464]
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 Sören Björn, 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
preliminary operations had been carried on for subduing the dunes on the
west coast.[465]
Page 331
Trees suited to Dune Plantations.
The tree which has been found 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 sea coast, 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
twenty years, and up to this age the trees on a hectare yield annually 350
kilogrammes of essence of turpentine, and 280 kilogrammes of resin, worth
together 110 francs. The expense of extraction and distillation is calculated
at 44 francs, and a clear profit of 66 francs per hectare, or more than five
dollars per acre, is left.[466] This is exclusive of the value of the timber,
when finally cut, which, of course, amounts to a very considerable sum.
The tree which has been found 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 sea coast, 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
twenty years, and up to this age the trees on a hectare yield annually 350
kilogrammes of essence of turpentine, and 280 kilogrammes of resin, worth
together 110 francs. The expense of extraction and distillation is calculated
at 44 francs, and a clear profit of 66 francs per hectare, or more than five
dollars per acre, is left.[466] This is exclusive of the value of the timber,
when finally cut, which, of course, amounts to a very considerable sum.
Page 332
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, may, perhaps, serve
a better purpose than any of them.
Extent of Dunes in Europe.
The dunes of Denmark, as we have seen, cover an area of two hundred
and sixty square miles, or one hundred and sixty-six thousand acres; those
of the Prussian coast are vaguely estimated at from eighty-five to one
hundred and ten thousand acres; those of Holland at one hundred and forty
thousand acres;[467] those of Gascony at about three hundred thousand
acres.[468] I do not find any estimate of their extent in other provinces of
France, in the duchies of Schleswig and Holstein, or in the Baltic provinces
of Russia, but it is probable that the entire quantity of dune land upon the
eastern shores of the Atlantic and the Baltic does not fall much short of a
million of acres.[469] This vast deposit of sea sand extends along the coast
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
inward 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
eastward, the ocean was closely following their retreat and swallowing up
the ground they had covered, as fast as their movement left it bare.
Planting the dunes has completely prevented the surface sands from
blowing over the soil to the leeward of the plantations, and though it has
not, in all cases, arrested the encroachments of the sea, it has so greatly
retarded the rapidity of their advance, that sandy coasts, when once covered
with forests, may be considered as substantially secure, so long as proper
measures are taken for the protection of the woods.
Dune Vineyards of Cap Breton.
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, may, perhaps, serve
a better purpose than any of them.
Extent of Dunes in Europe.
The dunes of Denmark, as we have seen, cover an area of two hundred
and sixty square miles, or one hundred and sixty-six thousand acres; those
of the Prussian coast are vaguely estimated at from eighty-five to one
hundred and ten thousand acres; those of Holland at one hundred and forty
thousand acres;[467] those of Gascony at about three hundred thousand
acres.[468] I do not find any estimate of their extent in other provinces of
France, in the duchies of Schleswig and Holstein, or in the Baltic provinces
of Russia, but it is probable that the entire quantity of dune land upon the
eastern shores of the Atlantic and the Baltic does not fall much short of a
million of acres.[469] This vast deposit of sea sand extends along the coast
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
inward 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
eastward, the ocean was closely following their retreat and swallowing up
the ground they had covered, as fast as their movement left it bare.
Planting the dunes has completely prevented the surface sands from
blowing over the soil to the leeward of the plantations, and though it has
not, in all cases, arrested the encroachments of the sea, it has so greatly
retarded the rapidity of their advance, that sandy coasts, when once covered
with forests, may be considered as substantially secure, so long as proper
measures are taken for the protection of the woods.
Dune Vineyards of Cap Breton.
Page 333
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 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.[470]
Removal of Dunes.
The artificial removal of dunes, no longer necessary as a protection,
does not appear to have been practised 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.[471]
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 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.[470]
Removal of Dunes.
The artificial removal of dunes, no longer necessary as a protection,
does not appear to have been practised 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.[471]
Page 334
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. As we have seen,
when once the interior of a dune is laid open to the wind, its contents are
soon scattered far 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
sea coast.[472]
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.
[473]
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.
As a general rule, inland sands are looser, dryer, and more inclined to
drift, than those of the sea coast, where the moist and saline atmosphere of
the ocean keeps them always more or less humid and cohesive. No shore
dunes are so movable as the medanos of Peru described in a passage quoted
from Pöppig on a former page, or as the sand hills of Poland, both of which
seem better entitled to the appellation of sand waves than those of the
The inland sand plains of Europe are either derived from the drifting of
dunes or other beach sands, or consist of diluvial deposits. As we have seen,
when once the interior of a dune is laid open to the wind, its contents are
soon scattered far 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
sea coast.[472]
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.
[473]
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.
As a general rule, inland sands are looser, dryer, and more inclined to
drift, than those of the sea coast, where the moist and saline atmosphere of
the ocean keeps them always more or less humid and cohesive. No shore
dunes are so movable as the medanos of Peru described in a passage quoted
from Pöppig on a former page, or as the sand hills of Poland, both of which
seem better entitled to the appellation of sand waves than those of the
Page 335
Sahara or of the Arabian desert. The sands of the valley of the Lower
Euphrates—themselves probably of submarine origin, and not derived from
dunes—are advancing to the northwest 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."[474] Loftus considers this sand flood as the
"vanguard of those vast drifts which, advancing from the southeast, threaten
eventually to overwhelm Babylon and Baghdad."
Euphrates—themselves probably of submarine origin, and not derived from
dunes—are advancing to the northwest 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."[474] Loftus considers this sand flood as the
"vanguard of those vast drifts which, advancing from the southeast, threaten
eventually to overwhelm Babylon and Baghdad."
Page 336
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 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 enough to overwhelm a province.
The Landes of Gascony.
The most remarkable sand plain of France lies at the southwestern
extremity of the empire, and is generally known as the Landes, or heaths, of
Gascony. Clavé 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. 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 Brémontier
invented his method of fixing the dunes by plantations of the maritime
pine."[475]
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
possible explanation of this irruption. He "passed two or three places where
the sand, issuing from the earth like 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 enough to overwhelm a province.
The Landes of Gascony.
The most remarkable sand plain of France lies at the southwestern
extremity of the empire, and is generally known as the Landes, or heaths, of
Gascony. Clavé 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. 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 Brémontier
invented his method of fixing the dunes by plantations of the maritime
pine."[475]
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
Page 337
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.[476]
The Belgian Campine.
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 wholly incapable of cultivation. Enormous sums have
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 has
prompted experiments in the planting of trees, especially the maritime pine,
upon this barren waste, and the results have been such as to show that its
sands may both be fixed and made productive, not only without loss, but
with positive pecuniary advantage.[477]
Sands and Steppes of Eastern Europe.
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
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.[476]
The Belgian Campine.
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 wholly incapable of cultivation. Enormous sums have
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 has
prompted experiments in the planting of trees, especially the maritime pine,
upon this barren waste, and the results have been such as to show that its
sands may both be fixed and made productive, not only without loss, but
with positive pecuniary advantage.[477]
Sands and Steppes of Eastern Europe.
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
Page 338
heaps of waste from the Olkuez mines are covered with sand to the depth of
four fathoms."[478] 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, may be employed with
advantage in the Polish deserts.
There are sand drifts in parts of the steppes of Russia, but in general the
soil of those vast plains is of a different, though very varied, composition,
and is covered with vegetation. The steppes, however, have many points of
analogy with the sand plains of Northern Germany, and if they are ever
fitted for civilized occupation, it must be by the same means, that is, by
planting forests. It is disputed whether the steppes 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 Xylæa 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
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.[479]
The trees 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.
[480]
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
four fathoms."[478] 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, may be employed with
advantage in the Polish deserts.
There are sand drifts in parts of the steppes of Russia, but in general the
soil of those vast plains is of a different, though very varied, composition,
and is covered with vegetation. The steppes, however, have many points of
analogy with the sand plains of Northern Germany, and if they are ever
fitted for civilized occupation, it must be by the same means, that is, by
planting forests. It is disputed whether the steppes 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 Xylæa 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
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.[479]
The trees 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.
[480]
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
Page 339
fixed so many thousand acres of drifting sands in Western Europe, will be,
partially at least, superseded by the tamarisk and the varnish tree.
Advantages of Reclaiming the Sands.
If we consider the quantity of waste land which has been made
productive by the planting of the sand hills and plains, and the extent of
fertile soil, the number of villages and other human improvements, and the
value of the harbors, which the same process has saved from being buried
under the rolling dunes, and at last swallowed up forever by the invasions
of the sea, we shall be inclined to rank Brémontier and Reventlov among
the greatest benefactors of their race. With the exception of the dikes of the
Netherlands, their labors are the first deliberate and direct attempts of man
to make himself, on a great scale, a geographical power, to restore natural
balances which earlier generations had disturbed, and to atone, by acts
guided by foreseeing and settled purpose, for the waste which thoughtless
improvidence had created.
Government Works.
There is an important political difference between these latter works and
the diking system of the Netherlandish and German coasts. The dikes
originally were, and in modern times very generally have been, private
enterprises, undertaken with no other aim than to add a certain quantity of
cultivable soil to the former possessions of their proprietor, or sometimes of
the state. In short, with few exceptions, they have been merely a pecuniary
investment, a mode of acquiring land not economically different from
purchase. The planting of the dunes, on the contrary, has always been a
public work, executed, not with the expectation of reaping a regular direct
percentage of income from the expenditure, but dictated by higher views of
state economy—by the same governmental principles, in fact, which
animate all commonwealths in repelling invasion by hostile armies, or in
repairing the damages that invading forces may have inflicted on the
general interests of the people. The restoration of the forests in the southern
part of France, as now conducted by the Government of that empire, is a
measure of the same elevated character as the fixing of the dunes. In former
partially at least, superseded by the tamarisk and the varnish tree.
Advantages of Reclaiming the Sands.
If we consider the quantity of waste land which has been made
productive by the planting of the sand hills and plains, and the extent of
fertile soil, the number of villages and other human improvements, and the
value of the harbors, which the same process has saved from being buried
under the rolling dunes, and at last swallowed up forever by the invasions
of the sea, we shall be inclined to rank Brémontier and Reventlov among
the greatest benefactors of their race. With the exception of the dikes of the
Netherlands, their labors are the first deliberate and direct attempts of man
to make himself, on a great scale, a geographical power, to restore natural
balances which earlier generations had disturbed, and to atone, by acts
guided by foreseeing and settled purpose, for the waste which thoughtless
improvidence had created.
Government Works.
There is an important political difference between these latter works and
the diking system of the Netherlandish and German coasts. The dikes
originally were, and in modern times very generally have been, private
enterprises, undertaken with no other aim than to add a certain quantity of
cultivable soil to the former possessions of their proprietor, or sometimes of
the state. In short, with few exceptions, they have been merely a pecuniary
investment, a mode of acquiring land not economically different from
purchase. The planting of the dunes, on the contrary, has always been a
public work, executed, not with the expectation of reaping a regular direct
percentage of income from the expenditure, but dictated by higher views of
state economy—by the same governmental principles, in fact, which
animate all commonwealths in repelling invasion by hostile armies, or in
repairing the damages that invading forces may have inflicted on the
general interests of the people. The restoration of the forests in the southern
part of France, as now conducted by the Government of that empire, is a
measure of the same elevated character as the fixing of the dunes. In former
Page 340
ages, forests were formed or protected simply for the sake of the shelter
they afforded to game, or for the timber they yielded; but the recent
legislation of France, and of some other Continental countries, on this
subject, looks to more distant as well as nobler ends, and these are among
the public acts which most strongly encourage the hope that the rulers of
Christendom are coming better to understand the true duties and interests of
civilized government.
they afforded to game, or for the timber they yielded; but the recent
legislation of France, and of some other Continental countries, on this
subject, looks to more distant as well as nobler ends, and these are among
the public acts which most strongly encourage the hope that the rulers of
Christendom are coming better to understand the true duties and interests of
civilized government.
Page 341
CHAPTER VI.
PROJECTED OR POSSIBLE
GEOGRAPHICAL CHANGES BY
MAN.
CUTTING OF MARINE ISTHMUSES—THE SUEZ CANAL—CANAL ACROSS ISTHMUS OF
DARIEN—CANALS TO THE DEAD SEA—MARITIME CANALS IN GREECE—CANAL OF
SAROS—CAPE COD CANAL—DIVERSION OF THE NILE—CHANGES IN THE CASPIAN—
IMPROVEMENTS IN NORTH AMERICAN HYDROGRAPHY—DIVERSION OF RHINE—
DRAINING OF THE ZUIDERZEE—WATERS OF THE KARST—SUBTERRANEAN WATERS
OF GREECE—SOIL BELOW ROCK—COVERING ROCKS WITH EARTH—WADIES OF
ARABIA PETRÆA—INCIDENTAL EFFECTS OF HUMAN ACTION—RESISTANCE TO
GREAT NATURAL FORCES—EFFECTS OF MINING—ESPY'S THEORIES—RIVER
SEDIMENT—NOTHING SMALL IN NATURE.
Cutting of Marine Isthmuses.
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.
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
PROJECTED OR POSSIBLE
GEOGRAPHICAL CHANGES BY
MAN.
CUTTING OF MARINE ISTHMUSES—THE SUEZ CANAL—CANAL ACROSS ISTHMUS OF
DARIEN—CANALS TO THE DEAD SEA—MARITIME CANALS IN GREECE—CANAL OF
SAROS—CAPE COD CANAL—DIVERSION OF THE NILE—CHANGES IN THE CASPIAN—
IMPROVEMENTS IN NORTH AMERICAN HYDROGRAPHY—DIVERSION OF RHINE—
DRAINING OF THE ZUIDERZEE—WATERS OF THE KARST—SUBTERRANEAN WATERS
OF GREECE—SOIL BELOW ROCK—COVERING ROCKS WITH EARTH—WADIES OF
ARABIA PETRÆA—INCIDENTAL EFFECTS OF HUMAN ACTION—RESISTANCE TO
GREAT NATURAL FORCES—EFFECTS OF MINING—ESPY'S THEORIES—RIVER
SEDIMENT—NOTHING SMALL IN NATURE.
Cutting of Marine Isthmuses.
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.
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
Page 342
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 have been actually made, but
no work of this sort, possessing real geographical or even commercial
importance, has yet 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 smoke pipes 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
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.
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 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
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 have been actually made, but
no work of this sort, possessing real geographical or even commercial
importance, has yet 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 smoke pipes 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
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.
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 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
Page 343
upon the ocean. In the remarkable gulf of Liimfjord in Jutland, nature has
given a singular example of a canal which she alternately opens as a marine
strait, and, by shutting 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 up some of the belts 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.
The Suez Canal.
If the Suez Canal—the greatest and most truly cosmopolite physical
improvement ever undertaken by man—shall prove successful, it will
considerably affect the basins of the Mediterranean and of the Red Sea,
though in a different manner, and probably in a less degree than the
diversion of the current of the Nile from the one to the other—to which I
shall presently refer—would do. It is, indeed, conceivable, that if a free
channel be once cut from sea to sea, the coincidence of a high tide and a
heavy south wind might produce a hydraulic force that would convert the
narrow canal into an open strait. In such a case, it is impossible to estimate,
or even to foresee, the consequences which might result from the
unobstructed mingling of the flowing and ebbing currents of the Red Sea
with the almost tideless waters of the Mediterranean. There can be no
doubt, however, that they would be of a most important character as
respects the simply geographical features and the organic life of both. But
the shallowness of the two seas at the termini of the canal, the action of the
tides of the one and the currents of the other, and the nature of the
intervening isthmus, render the occurrence of such a cataclysm in the
highest degree improbable. The obstruction of the canal by sea sand at both
ends is a danger far more difficult to guard against and avert, than an
irruption of the waters of either sea.
given a singular example of a canal which she alternately opens as a marine
strait, and, by shutting 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 up some of the belts 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.
The Suez Canal.
If the Suez Canal—the greatest and most truly cosmopolite physical
improvement ever undertaken by man—shall prove successful, it will
considerably affect the basins of the Mediterranean and of the Red Sea,
though in a different manner, and probably in a less degree than the
diversion of the current of the Nile from the one to the other—to which I
shall presently refer—would do. It is, indeed, conceivable, that if a free
channel be once cut from sea to sea, the coincidence of a high tide and a
heavy south wind might produce a hydraulic force that would convert the
narrow canal into an open strait. In such a case, it is impossible to estimate,
or even to foresee, the consequences which might result from the
unobstructed mingling of the flowing and ebbing currents of the Red Sea
with the almost tideless waters of the Mediterranean. There can be no
doubt, however, that they would be of a most important character as
respects the simply geographical features and the organic life of both. But
the shallowness of the two seas at the termini of the canal, the action of the
tides of the one and the currents of the other, and the nature of the
intervening isthmus, render the occurrence of such a cataclysm in the
highest degree improbable. The obstruction of the canal by sea sand at both
ends is a danger far more difficult to guard against and avert, than an
irruption of the waters of either sea.
Page 344
There is, then, no reason to expect any change of coast lines or of
natural navigable channels as a direct consequence of the opening of the
Suez Canal, but it 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[481]—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 by the laws of their organization to warmer
temperatures 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,
when the canal shall be opened, there will be an 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.
A collateral feature of this great project 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 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 east 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
natural navigable channels as a direct consequence of the opening of the
Suez Canal, but it 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[481]—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 by the laws of their organization to warmer
temperatures 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,
when the canal shall be opened, there will be an 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.
A collateral feature of this great project 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 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 east 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
Page 345
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. If the canal succeeds, considerable towns will
grow up at once 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 the city at Lake Timsah, may
become the capital of the government which has been so long established at
Cairo.
Canal across the Isthmus of Darien.
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.
It has been by no means shown that the construction of such a channel is
possible, and, if it were opened, it is highly probable that sand bars would
accumulate at both entrances, so as to obstruct any powerful current
through it. But if we suppose the work to be actually accomplished, there
would be, in the first place, such a mixture of the animal and vegetable life
of the two great oceans as I have stated to be likely to result from the
opening of the Suez Canal between two much smaller basins. In the next
place, if the channel were not obstructed by sand bars, it might sooner or
later be greatly widened and deepened by the mechanical action of the
current through it, and consequences, not inferior in magnitude to any
physical revolution which has taken place since man appeared upon the
earth, might result from it.
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. If the canal succeeds, considerable towns will
grow up at once 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 the city at Lake Timsah, may
become the capital of the government which has been so long established at
Cairo.
Canal across the Isthmus of Darien.
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.
It has been by no means shown that the construction of such a channel is
possible, and, if it were opened, it is highly probable that sand bars would
accumulate at both entrances, so as to obstruct any powerful current
through it. But if we suppose the work to be actually accomplished, there
would be, in the first place, such a mixture of the animal and vegetable life
of the two great oceans as I have stated to be likely to result from the
opening of the Suez Canal between two much smaller basins. In the next
place, if the channel were not obstructed by sand bars, it might sooner or
later be greatly widened and deepened by the mechanical action of the
current through it, and consequences, not inferior in magnitude to any
physical revolution which has taken place since man appeared upon the
earth, might result from it.
Page 346
What those consequences would be is in a great degree matter of pure
conjecture, and there is much room for the exercise of the imagination on
the subject; but, as more than one geographer has suggested, there is one
possible result which throws all other conceivable effects of such a work
quite into the shade. I refer to changes in the course of the two great oceanic
rivers, the Gulf Stream and the corresponding current on the Pacific side of
the isthmus. The warm waters which the Gulf Stream transports to high
latitudes and then spreads out, like an expanded hand, along the eastern
shores of the Atlantic, give out, as they cool, heat enough to raise the mean
temperature of Western Europe several degrees. In fact, the Gulf Stream is
the principal cause of the superiority of the climate of Western Europe over
those of Eastern America and Eastern Asia in the corresponding latitudes.
All the meteorological conditions of the former region are in a great
measure regulated by it, and hence it is the grandest and most beneficent of
all purely geographical phenomena. We do not yet know enough of the laws
which govern the movements of this mighty flood of warmth and life to be
able to say whether its current would be perceptibly affected by the
severance of the Isthmus of Darien; but as it enters and sweeps round the
Gulf of Mexico, it is possible that the removal of the resistance of the land
which forms the western shore of that sea, might allow the stream to
maintain its original westward direction, and join itself to the tropical
current of the Pacific.
The effect of such a change would be an immediate depression of the
mean temperature of Western Europe to the level of that of Eastern
America, and perhaps the climate of the former continent might become as
excessive as that of the latter, or even a new "ice period" be occasioned by
the withdrawal of so important a source of warmth from the northern zones.
Hence would result the extinction of vast multitudes of land and sea plants
and animals, and a total revolution in the domestic and rural economy of
human life in all those countries from which the New World has received its
civilized population. Other scarcely less startling consequences may be
imagined as possible; but the whole speculation is too dreary, distant, and
improbable to deserve to be long indulged in.[482]
Canals to the Dead Sea.
conjecture, and there is much room for the exercise of the imagination on
the subject; but, as more than one geographer has suggested, there is one
possible result which throws all other conceivable effects of such a work
quite into the shade. I refer to changes in the course of the two great oceanic
rivers, the Gulf Stream and the corresponding current on the Pacific side of
the isthmus. The warm waters which the Gulf Stream transports to high
latitudes and then spreads out, like an expanded hand, along the eastern
shores of the Atlantic, give out, as they cool, heat enough to raise the mean
temperature of Western Europe several degrees. In fact, the Gulf Stream is
the principal cause of the superiority of the climate of Western Europe over
those of Eastern America and Eastern Asia in the corresponding latitudes.
All the meteorological conditions of the former region are in a great
measure regulated by it, and hence it is the grandest and most beneficent of
all purely geographical phenomena. We do not yet know enough of the laws
which govern the movements of this mighty flood of warmth and life to be
able to say whether its current would be perceptibly affected by the
severance of the Isthmus of Darien; but as it enters and sweeps round the
Gulf of Mexico, it is possible that the removal of the resistance of the land
which forms the western shore of that sea, might allow the stream to
maintain its original westward direction, and join itself to the tropical
current of the Pacific.
The effect of such a change would be an immediate depression of the
mean temperature of Western Europe to the level of that of Eastern
America, and perhaps the climate of the former continent might become as
excessive as that of the latter, or even a new "ice period" be occasioned by
the withdrawal of so important a source of warmth from the northern zones.
Hence would result the extinction of vast multitudes of land and sea plants
and animals, and a total revolution in the domestic and rural economy of
human life in all those countries from which the New World has received its
civilized population. Other scarcely less startling consequences may be
imagined as possible; but the whole speculation is too dreary, distant, and
improbable to deserve to be long indulged in.[482]
Canals to the Dead Sea.
Page 347
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.[483] The
hypsometrical observations of Bertou, Roth, and others, render it highly
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
mean 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 the east 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 its northern extremity, 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 thus created. Its length, however, would
certainly exceed one hundred and fifty miles, and its mean breadth,
between the Mediterranean and the Dead Sea, and between the Dead Sea
and the Red Sea, presents many interesting considerations.[483] The
hypsometrical observations of Bertou, Roth, and others, render it highly
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
mean 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 the east 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 its northern extremity, 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 thus created. Its length, however, would
certainly exceed one hundred and fifty miles, and its mean breadth,
Page 348
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
Southeastern 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 east 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 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.
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 these is the cut made by Xerxes through the rock
which connects the promontory of Mount Athos with the mainland; the
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
Southeastern 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 east 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 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.
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 these is the cut made by Xerxes through the rock
which connects the promontory of Mount Athos with the mainland; the
Page 349
other, a navigable canal through the Isthmus of Corinth. In spite of the
testimony of Herodotus and Thucydides, 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.
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 will no
doubt be opened between the gulfs of Lepanto and Ægina. 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.
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 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 would be entitled to a higher rank than
simply as artificial means of transit.
Canal of Saros.
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
testimony of Herodotus and Thucydides, 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.
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 will no
doubt be opened between the gulfs of Lepanto and Ægina. 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.
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 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 would be entitled to a higher rank than
simply as artificial means of transit.
Canal of Saros.
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
Page 350
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, diminish 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 Ægean, and it would have the
important advantage of obliging an enemy to maintain two blockading
fleets instead of one.
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 setting through the new strait are still more serious
objections.
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,
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, diminish 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 Ægean, and it would have the
important advantage of obliging an enemy to maintain two blockading
fleets instead of one.
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 setting through the new strait are still more serious
objections.
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,
Page 351
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.[484] Indeed, Arabic historians affirm
that in the tenth century the Ethiopians dammed the river, and, for a whole
year, cut off its waters from Egypt. 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. 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 Kesseir. 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, at no great elevation above the bed of
the river. The Libyan desert is so much higher than the Nile below the
junction of the two principal branches at Khartum, that there is no reason to
believe a new channel for their united waters 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 sent to the Atlantic by the Niger,
lost in the inland lakes of Central Africa, or employed to fertilize the Libyan
sand wastes.
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
conciliate the Abyssinian kings by large presents, and by some concessions
to the oppressed Christians of Egypt.[484] Indeed, Arabic historians affirm
that in the tenth century the Ethiopians dammed the river, and, for a whole
year, cut off its waters from Egypt. 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. 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 Kesseir. 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, at no great elevation above the bed of
the river. The Libyan desert is so much higher than the Nile below the
junction of the two principal branches at Khartum, that there is no reason to
believe a new channel for their united waters 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 sent to the Atlantic by the Niger,
lost in the inland lakes of Central Africa, or employed to fertilize the Libyan
sand wastes.
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
Page 352
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 abstraction of so large an evaporable
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 Northeastern 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 northeastern 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; its waters would be more or less freshened, and its 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.
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
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 abstraction of so large an evaporable
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 Northeastern 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 northeastern 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; its waters would be more or less freshened, and its 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.
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
Page 353
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 reëstablished, 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.
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
very moderate inclination, there is reason to suppose that important changes
in the course of rivers might be accomplished. Our knowledge of the
drainage of North America is much more complete, and it is certain that
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 reëstablished, 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.
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
very moderate inclination, there is reason to suppose that important changes
in the course of rivers might be accomplished. Our knowledge of the
drainage of North America is much more complete, and it is certain that
Page 354
there are numerous points 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. Hence a channel might be constructed, which would draw
off into the valley of the Genesee any desirable proportion of the water
naturally discharged by the Niagara. 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
toward 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 create
additional outlets 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 produce incalculable effects, both upon that lake and upon
the great chain of inland waters which communicate with it.
The summit level between Lake Michigan and the Des Plaines, a
tributary of the Mississippi, is only twenty-seven feet above the lake, and
the intervening distance is but a very few miles. It has often been proposed
to cut an open channel across this ridge, and there is no doubt of the
practicability of the project. Were this accomplished, although such a cut
would not, of itself, form a navigable canal, a part of the waters of Lake
Michigan would be contributed to the Gulf of Mexico, instead of to that of
St. Lawrence, and the flow 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 introduction of a larger body of cold water
into the beds of these rivers 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 natural discharge, would not be absolutely without
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. Hence a channel might be constructed, which would draw
off into the valley of the Genesee any desirable proportion of the water
naturally discharged by the Niagara. 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
toward 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 create
additional outlets 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 produce incalculable effects, both upon that lake and upon
the great chain of inland waters which communicate with it.
The summit level between Lake Michigan and the Des Plaines, a
tributary of the Mississippi, is only twenty-seven feet above the lake, and
the intervening distance is but a very few miles. It has often been proposed
to cut an open channel across this ridge, and there is no doubt of the
practicability of the project. Were this accomplished, although such a cut
would not, of itself, form a navigable canal, a part of the waters of Lake
Michigan would be contributed to the Gulf of Mexico, instead of to that of
St. Lawrence, and the flow 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 introduction of a larger body of cold water
into the beds of these rivers 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 natural discharge, would not be absolutely without
Page 355
influence on the St. Lawrence, though probably the effect would be too
small to be in any way perceptible.
Diversion of the Rhine.
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.
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
small to be in any way perceptible.
Diversion of the Rhine.
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.
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
Page 356
two thousand square miles, or about one million three hundred thousand
acres. The seaward half, or that portion lying northwest 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,
and there 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 fresh-water 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. 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. 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, and its meteorological effects, though perhaps not
perceptible on the coast, could hardly fail to be appreciable in the interior of
Holland.
Waters of the Karst.
The singular structure of the Karst, the great limestone plateau lying to
the north of Trieste, has suggested some engineering operations which
acres. The seaward half, or that portion lying northwest 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,
and there 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 fresh-water 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. 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. 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, and its meteorological effects, though perhaps not
perceptible on the coast, could hardly fail to be appreciable in the interior of
Holland.
Waters of the Karst.
The singular structure of the Karst, the great limestone plateau lying to
the north of Trieste, has suggested some engineering operations which
Page 357
might be attended with sensible effects upon the geography of the province.
I have described this table land as, though now bare of forests, and almost
of vegetation, having once been covered with woods, and as being
completely honeycombed by caves through which the drainage of that
region is conducted. Schmidl has spent years in studying the subterranean
geography and hydrography of this singular district, and his discoveries,
and those of earlier cave-hunters, have led to various proposals of physical
improvement of a novel character. Many of the underground water courses
of the Karst are without visible outlet, and, in some instances at least, they,
no doubt, send their waters, by deep channels, to the Adriatic.[485] The city
of Trieste is very insufficiently provided 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 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.
Subterranean Waters of Greece.
There are parts of continental Greece which resemble the Karst and the
adjacent plains in being provided with a natural subterranean drainage. The
superfluous waters run off into limestone caves called catavothra
(καταβόθρα). In ancient times, the entrances to the catavothra were
enlarged or partially closed as the convenience of drainage or irrigation
required, and there is no doubt that similar measures might be adopted at
the present day with great advantage both to the salubrity and the
productiveness of the regions so drained.
Soil below Rock.
I have described this table land as, though now bare of forests, and almost
of vegetation, having once been covered with woods, and as being
completely honeycombed by caves through which the drainage of that
region is conducted. Schmidl has spent years in studying the subterranean
geography and hydrography of this singular district, and his discoveries,
and those of earlier cave-hunters, have led to various proposals of physical
improvement of a novel character. Many of the underground water courses
of the Karst are without visible outlet, and, in some instances at least, they,
no doubt, send their waters, by deep channels, to the Adriatic.[485] The city
of Trieste is very insufficiently provided 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 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.
Subterranean Waters of Greece.
There are parts of continental Greece which resemble the Karst and the
adjacent plains in being provided with a natural subterranean drainage. The
superfluous waters run off into limestone caves called catavothra
(καταβόθρα). In ancient times, the entrances to the catavothra were
enlarged or partially closed as the convenience of drainage or irrigation
required, and there is no doubt that similar measures might be adopted at
the present day with great advantage both to the salubrity and the
productiveness of the regions so drained.
Soil below Rock.
Page 358
One of the most singular changes of natural surface effected by man is
that observed by Beechey and by Barth at Lîn Tefla, and near Gebel
Genûnes, in the district of Ben Gâsi, 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.[486] 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.
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.[487] 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. 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.
Wadies of Arabia, Petræa.
that observed by Beechey and by Barth at Lîn Tefla, and near Gebel
Genûnes, in the district of Ben Gâsi, 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.[486] 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.
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.[487] 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. 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.
Wadies of Arabia, Petræa.
Page 359
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
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. 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, containing a hundred
acres, perhaps much more. This is 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.
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
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
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
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. 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, containing a hundred
acres, perhaps much more. This is 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.
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
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
Page 360
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. An investigation undertaken by Councillor Reinhard and
myself, at the instance of the Society of Science, 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."[488] 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,[489] 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 toward the sea, and terminating
in a precipice forty or fifty feet high, through natural openings 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
northwest 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.[490]
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
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. An investigation undertaken by Councillor Reinhard and
myself, at the instance of the Society of Science, 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."[488] 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,[489] 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 toward the sea, and terminating
in a precipice forty or fifty feet high, through natural openings 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
northwest 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.[490]
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
Page 361
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
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; 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 Græcia 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.
The soil near cities, the street sweepings of which are spread upon the
ground as manure, is perceptibly raised by them and by other effects of
human industry, and in spite of all efforts to remove the waste, the level of
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
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; 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 Græcia 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.
The soil near cities, the street sweepings of which are spread upon the
ground as manure, is perceptibly raised by them and by other effects of
human industry, and in spite of all efforts to remove the waste, the level of
Page 362
the ground on which large towns stand is constantly elevated. The present
streets of Rome are twenty feet 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.
Resistance to Great Natural Forces.
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.[491]
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
streets of Rome are twenty feet 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.
Resistance to Great Natural Forces.
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.[491]
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
Page 363
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
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 was felt over
a twelfth part of the earth's surface, was probably 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
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
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
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 was felt over
a twelfth part of the earth's surface, was probably 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
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
Page 364
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.[492] When the opening was made, fluid lava
poured forth and flowed rapidly toward 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."[493] 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.[494]
Effects of Mining.
The excavations made by man, for mining and other purposes, may
sometimes occasion disturbance of the surface by the subsidence of the
strata above them, as in the case of the mine of Fahlun, but such accidents
must always be too inconsiderable in extent to deserve notice in a
geographical point of view. Such excavations, however, 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 the magnetic and electrical
condition of the earth's crust to a sensible degree.
Accidental fires in mines of coal or lignite sometimes lead to
consequences not only destructive to large quantities of valuable material,
but may, directly or indirectly, produce results important in geography. The
coal occasionally takes fire from the miners' lights or other fires used by
them, and, if long exposed to air in deserted galleries, may be
spontaneously kindled. Under favorable circumstances, a stratum of coal
will burn till 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
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.[492] When the opening was made, fluid lava
poured forth and flowed rapidly toward 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."[493] 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.[494]
Effects of Mining.
The excavations made by man, for mining and other purposes, may
sometimes occasion disturbance of the surface by the subsidence of the
strata above them, as in the case of the mine of Fahlun, but such accidents
must always be too inconsiderable in extent to deserve notice in a
geographical point of view. Such excavations, however, 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 the magnetic and electrical
condition of the earth's crust to a sensible degree.
Accidental fires in mines of coal or lignite sometimes lead to
consequences not only destructive to large quantities of valuable material,
but may, directly or indirectly, produce results important in geography. The
coal occasionally takes fire from the miners' lights or other fires used by
them, and, if long exposed to air in deserted galleries, may be
spontaneously kindled. Under favorable circumstances, a stratum of coal
will burn till 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
Page 365
perceptible degree of heat to the surface, and the author just quoted cites
cases where this heat has been advantageously employed in forcing
vegetation.[495]
Espy's Theories.
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 very 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 small to have been yet detected.
River Sediment.
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
cases where this heat has been advantageously employed in forcing
vegetation.[495]
Espy's Theories.
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 very 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 small to have been yet detected.
River Sediment.
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
Page 366
of the Ganges 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 the earth in the
Bay of Bengal. In such cases, then, human action must rank among
geological influences.
Nothing Small in Nature.
It is a legal maxim that "the law concerneth not itself with trifles," de
minimus 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.[496] 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 toward the determination of the great
question, whether man is of nature or above her.
transported by that river to the sea, and of course have strengthened the
effects, whatever they may be, of thickening the crust of the earth in the
Bay of Bengal. In such cases, then, human action must rank among
geological influences.
Nothing Small in Nature.
It is a legal maxim that "the law concerneth not itself with trifles," de
minimus 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.[496] 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 toward the determination of the great
question, whether man is of nature or above her.
Page 367
FOOTNOTES:
[1] In the Middle Ages, feudalism, and a nominal Christianity whose
corruptions had converted the most beneficent of 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 these 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 cause 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."—Résumé de l'Histoire du Commerce, p.
156.
The abbey of Saint-Germain-des-Prés, which, in the time of Charlemagne,
had possessed a million of acres, was, down to the Revolution, still so wealthy,
that the personal income of the abbot was 300,000 livres. The abbey of Saint-
Denis was nearly as rich as that of Saint-Germain-des-Prés.—Lavergne,
Économie Rurale de la France, p. 104.
Paul Louis Courier quotes from La Bruyère 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, sowing, and harvesting, and therefore deserve some small
share of the bread they have grown." "These are his own words," adds Courier;
"he is speaking of the fortunate peasants, of those who had work and bread, and
they were then the few."—Pétition à la Chambre des Députís pour les Villageois
que l'on empêche de danser.
[1] In the Middle Ages, feudalism, and a nominal Christianity whose
corruptions had converted the most beneficent of 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 these 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 cause 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."—Résumé de l'Histoire du Commerce, p.
156.
The abbey of Saint-Germain-des-Prés, which, in the time of Charlemagne,
had possessed a million of acres, was, down to the Revolution, still so wealthy,
that the personal income of the abbot was 300,000 livres. The abbey of Saint-
Denis was nearly as rich as that of Saint-Germain-des-Prés.—Lavergne,
Économie Rurale de la France, p. 104.
Paul Louis Courier quotes from La Bruyère 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, sowing, and harvesting, and therefore deserve some small
share of the bread they have grown." "These are his own words," adds Courier;
"he is speaking of the fortunate peasants, of those who had work and bread, and
they were then the few."—Pétition à la Chambre des Députís pour les Villageois
que l'on empêche de danser.
Page 368
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 offences, he enumerates about
thirty seignorial rights, the very origin and nature of some of which are now
unknown, while those of some others, claimed and enforced by ecclesiastical as
well as by temporal lords, are as repulsive to humanity and morality, as the worst
abuses ever practised by heathen despotism. Most of these, indeed, had been
commuted for money payments, and were levied on the peasantry as pecuniary
imposts for the benefit of prelates and lay lords, who, by virtue of their nobility,
were exempt from taxation. Who can wonder at the hostility of the French
plebeian classes toward the aristocracy in the days of the Revolution?
[2] 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 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.
[3] 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, 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
Pflanzenwelt in der Zeit.
[4]
Gods Almagt wenkte van den troon,
En schiep elk volk een land ter woon:
Hier vestte Zij een grondgebied,
Dat Zij ons zelven scheppen liet.
[5] The udometric measurements of Belgrand, reported in the Annales
Forestières for 1854, and discussed by Vallès in chap. vi of his Études sur les
Inondations, constitute the earliest, and, in some respects, the most remarkable
series known to me, of persevering and systematic observations bearing directly
and exclusively upon the influence of human action on climate, or, to speak more
accurately, on precipitation and natural drainage. The conclusions of Belgrand,
however, and of Vallès, who adopts them, have not been generally accepted by
the scientific world, and they seem to have been, in part at least, refuted by 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 offences, he enumerates about
thirty seignorial rights, the very origin and nature of some of which are now
unknown, while those of some others, claimed and enforced by ecclesiastical as
well as by temporal lords, are as repulsive to humanity and morality, as the worst
abuses ever practised by heathen despotism. Most of these, indeed, had been
commuted for money payments, and were levied on the peasantry as pecuniary
imposts for the benefit of prelates and lay lords, who, by virtue of their nobility,
were exempt from taxation. Who can wonder at the hostility of the French
plebeian classes toward the aristocracy in the days of the Revolution?
[2] 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 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.
[3] 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, 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
Pflanzenwelt in der Zeit.
[4]
Gods Almagt wenkte van den troon,
En schiep elk volk een land ter woon:
Hier vestte Zij een grondgebied,
Dat Zij ons zelven scheppen liet.
[5] The udometric measurements of Belgrand, reported in the Annales
Forestières for 1854, and discussed by Vallès in chap. vi of his Études sur les
Inondations, constitute the earliest, and, in some respects, the most remarkable
series known to me, of persevering and systematic observations bearing directly
and exclusively upon the influence of human action on climate, or, to speak more
accurately, on precipitation and natural drainage. The conclusions of Belgrand,
however, and of Vallès, who adopts them, have not been generally accepted by
the scientific world, and they seem to have been, in part at least, refuted by the
Page 369
arguments of Héricourt and the observations of Cantegril, Jeandel, and Belland.
See chapter iii: The Woods.
[6] Verses addressed by G. C. to Sir Walter Raleigh.—Hakluyt, i, p. 668.
[7]
——I troer, at Synets Sands er lagt i Öiet,
Mens dette kun er Redskab. Synet strömmer
Fra Sjælens Dyb, og Öiets fine Nerver
Gaae ud fra Hjernens hemmelige Værksted.
Henrik Hertz, Kong René's
Datter, sc. ii.
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.
[8] 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 serves as a guide to the eye, but
there are sportsmen who fire with the but 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 blow pipe 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.
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. Avé-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, would strike it at a small
angle, and glance from its flat 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 properly 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 all of them, and marksmanship depends almost wholly upon the
power of that organ, whose directions the blind muscles implicitly follow. It is
perhaps not out of place to observe here that our English word aim comes from
the Latin æstimo, I calculate or estimate. See Wedgwood's Dictionary of English
Etymology, and the note to the American edition, under Aim.
See chapter iii: The Woods.
[6] Verses addressed by G. C. to Sir Walter Raleigh.—Hakluyt, i, p. 668.
[7]
——I troer, at Synets Sands er lagt i Öiet,
Mens dette kun er Redskab. Synet strömmer
Fra Sjælens Dyb, og Öiets fine Nerver
Gaae ud fra Hjernens hemmelige Værksted.
Henrik Hertz, Kong René's
Datter, sc. ii.
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.
[8] 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 serves as a guide to the eye, but
there are sportsmen who fire with the but 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 blow pipe 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.
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. Avé-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, would strike it at a small
angle, and glance from its flat 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 properly 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 all of them, and marksmanship depends almost wholly upon the
power of that organ, whose directions the blind muscles implicitly follow. It is
perhaps not out of place to observe here that our English word aim comes from
the Latin æstimo, I calculate or estimate. See Wedgwood's Dictionary of English
Etymology, and the note to the American edition, under Aim.
Page 370
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.
It has been much doubted whether the artists of the classic ages possessed a
more perfect sight than those of modern times, or whether, in executing their
minute mosaics and gem engravings, they used magnifiers. Glasses ground
convex have been found at Pompeii, but they are too rudely 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.
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.
[9] Antiquity of Man, p. 377.
[10] "One of them [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.
It has been said that stone weapons are not found in Sicily, except in certain
caves half filled with the skeletons of extinct animals. If they have not been
found in that island in more easily accessible localities, I suspect it is because
eyes familiar with such objects have not sought for them. In January, 1854, I
picked up an arrow head of quartz in a little ravine or furrow just washed out by
a heavy rain, in a field near the Simeto. It is rudely fashioned, but its artificial
character and its special purpose are quite unequivocal.
[11] Probably no cultivated vegetable affords so good an opportunity of
studying the laws of acclimation of plants as maize or Indian corn. Maize is
grown from the tropics to at least lat. 47° 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
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.
It has been much doubted whether the artists of the classic ages possessed a
more perfect sight than those of modern times, or whether, in executing their
minute mosaics and gem engravings, they used magnifiers. Glasses ground
convex have been found at Pompeii, but they are too rudely 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.
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.
[9] Antiquity of Man, p. 377.
[10] "One of them [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.
It has been said that stone weapons are not found in Sicily, except in certain
caves half filled with the skeletons of extinct animals. If they have not been
found in that island in more easily accessible localities, I suspect it is because
eyes familiar with such objects have not sought for them. In January, 1854, I
picked up an arrow head of quartz in a little ravine or furrow just washed out by
a heavy rain, in a field near the Simeto. It is rudely fashioned, but its artificial
character and its special purpose are quite unequivocal.
[11] Probably no cultivated vegetable affords so good an opportunity of
studying the laws of acclimation of plants as maize or Indian corn. Maize is
grown from the tropics to at least lat. 47° 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
Page 371
accommodate itself to new conditions of temperature and season seems almost
unlimited. We may easily suppose a variety of this grain, which had become
acclimated in still higher latitudes, to have been lost, and in such case the failure
to raise a crop from seed brought from some distance to the south would not
prove that the climate had become colder.
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 seed. Meteorological
observations, however, do not show any amelioration of the summer climate in
those States within that period. See Appendix, No. 1.
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 accomodation 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 Pöppig, the ears of this grain found in old Peruvian
tombs belong to varieties not now known in Peru.—Travels in Peru, chap. vii.
[12] 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 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, Économie Rurale de la France, pp. 259-291.
I believe there is no doubt that the cultivation of madder in the vicinity of
Avignon is of recent introduction; but it appears from Fuller and other evidence,
that this plant was grown in Europe before the middle of the seventeenth century.
The madder brought to France from Persia may be of a different species, or, at
least, variety. "Some two years since," says Fuller, "madder was sown by Sir
Nicholas Crispe at Debtford, and I hope will have good success; first because it
groweth in Zeland in the same (if not a more northern) latitude. Secondly,
because wild madder grows here in abundance; and why may not tame madder if
cicurated by art. Lastly, because as good as any grew some thirty years since at
Barn-Elms, in Surrey, though it quit not cost through some error in the first
planter thereof, which now we hope will be rectified."—Fuller, Worthies of
England, ii, pp. 57, 58.
Perhaps the recent diseases of the olive, the vine, and the silkworm—the
prevailing malady of which insect is supposed by some to be the effect of an
incipient decay of the mulberry tree—may be, in part, due to changes produced
in the character of the soil by exhaustion through long cultivation.
[13] In many parts of New England there are tracts, 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
unlimited. We may easily suppose a variety of this grain, which had become
acclimated in still higher latitudes, to have been lost, and in such case the failure
to raise a crop from seed brought from some distance to the south would not
prove that the climate had become colder.
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 seed. Meteorological
observations, however, do not show any amelioration of the summer climate in
those States within that period. See Appendix, No. 1.
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 accomodation 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 Pöppig, the ears of this grain found in old Peruvian
tombs belong to varieties not now known in Peru.—Travels in Peru, chap. vii.
[12] 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 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, Économie Rurale de la France, pp. 259-291.
I believe there is no doubt that the cultivation of madder in the vicinity of
Avignon is of recent introduction; but it appears from Fuller and other evidence,
that this plant was grown in Europe before the middle of the seventeenth century.
The madder brought to France from Persia may be of a different species, or, at
least, variety. "Some two years since," says Fuller, "madder was sown by Sir
Nicholas Crispe at Debtford, and I hope will have good success; first because it
groweth in Zeland in the same (if not a more northern) latitude. Secondly,
because wild madder grows here in abundance; and why may not tame madder if
cicurated by art. Lastly, because as good as any grew some thirty years since at
Barn-Elms, in Surrey, though it quit not cost through some error in the first
planter thereof, which now we hope will be rectified."—Fuller, Worthies of
England, ii, pp. 57, 58.
Perhaps the recent diseases of the olive, the vine, and the silkworm—the
prevailing malady of which insect is supposed by some to be the effect of an
incipient decay of the mulberry tree—may be, in part, due to changes produced
in the character of the soil by exhaustion through long cultivation.
[13] In many parts of New England there are tracts, 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
Page 372
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 toward 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 favor the supposition that a secular desiccation
is still going on in central Africa. 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. There is
reason to suspect a similar revolution in Arabia Petræa. 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. There is little
probability that any considerable part of the Sinaitic peninsula has been wooded
since its first occupation by man, and we must seek the cause of its increasing
dryness elsewhere than in the removal of the forest.
[14] The soil of newly subdued countries is generally in a high degree
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 one of the earliest settlers of the
State of Ohio, a very intelligent and observing person, 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 sown when the
ground had been twenty years under cultivation.
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
these tracts compose basins apparently scarcely at all exposed to any local
influence in the way of percolation or infiltration of water toward 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 favor the supposition that a secular desiccation
is still going on in central Africa. 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. There is
reason to suspect a similar revolution in Arabia Petræa. 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. There is little
probability that any considerable part of the Sinaitic peninsula has been wooded
since its first occupation by man, and we must seek the cause of its increasing
dryness elsewhere than in the removal of the forest.
[14] The soil of newly subdued countries is generally in a high degree
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 one of the earliest settlers of the
State of Ohio, a very intelligent and observing person, 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 sown when the
ground had been twenty years under cultivation.
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
Page 373
influences of light and shade and atmosphere from its predecessors. Hence 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.
[15] 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 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 toward 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 an easterly current comes from the west, and flows toward 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-ward 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 seventeenth century so write it. In Hakluyt (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. Hakewell says: "The sonne
cannot goe more southernely from vs, nor come more northernely towards vs."
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 in -wardly given by this lexicographer is from Donne, where it
means toward the west.
Shakspeare, 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 toward which motion is supposed, the
others that from which it proceeds.
We use an east wind, an eastern wind, and an easterly wind, to signify the
same thing. The two former expressions are old, and constant in meaning; the
last is recent, superfluous, and equivocal. See Appendix, No. 2.
[16] I do not here speak of the vast prairie region of the Mississippi valley,
which cannot properly be 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
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.
[15] 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 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 toward 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 an easterly current comes from the west, and flows toward 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-ward 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 seventeenth century so write it. In Hakluyt (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. Hakewell says: "The sonne
cannot goe more southernely from vs, nor come more northernely towards vs."
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 in -wardly given by this lexicographer is from Donne, where it
means toward the west.
Shakspeare, 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 toward which motion is supposed, the
others that from which it proceeds.
We use an east wind, an eastern wind, and an easterly wind, to signify the
same thing. The two former expressions are old, and constant in meaning; the
last is recent, superfluous, and equivocal. See Appendix, No. 2.
[16] I do not here speak of the vast prairie region of the Mississippi valley,
which cannot properly be 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
Page 374
as of the Eastern forest land, that they had arrived at a state of equilibrium,
though under very different conditions.
[17] 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
trees of fair dimensions, except where cultivation and pasturage kept down the
forest growth.
[18] 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 Kärr. The elder
Læstadius divides the Kärr 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.
Hömyror, paludes graminosæ. 2. Dy, paludes profundæ. 3. Flarkmyror, or proper
kärr, paludes limosæ. 4. Fjällmyror, paludes uliginosæ. 5. Tufmyror, paludes
cæspitosæ. 6. Rismyror, paludes virgatæ. 7. Starrängar, prata irrigata, with their
subdivisions, dry starrängar or risängar, wet starrängar and fräkengropar. 8.
Pölar, laeunæ. 9. Gölar, fossæ inundatæ. The Mossar, paludes turfosæ, which
are of great extent, have but two species: 1. Torfmossar, called also Mossmyror
and Snottermyror, and, 2. Björnmossar.
The accumulations of stagnant or stagnating water originating in bogs are
distinguished into Trāsk, stagna, and Tjernar or Tjärnar (sing. Tjern or Tjärn),
stagnatiles. Trāsk are pools fed by bogs, or water emanating from them, and their
bottoms are slimy; Tjernar are small Träsk situated within the limits of Mossar.
—L. L. Læstadius, om Möjligheten af Uppodlingar i Lappmarken, pp. 23, 24.
[19] 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
though under very different conditions.
[17] 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
trees of fair dimensions, except where cultivation and pasturage kept down the
forest growth.
[18] 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 Kärr. The elder
Læstadius divides the Kärr 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.
Hömyror, paludes graminosæ. 2. Dy, paludes profundæ. 3. Flarkmyror, or proper
kärr, paludes limosæ. 4. Fjällmyror, paludes uliginosæ. 5. Tufmyror, paludes
cæspitosæ. 6. Rismyror, paludes virgatæ. 7. Starrängar, prata irrigata, with their
subdivisions, dry starrängar or risängar, wet starrängar and fräkengropar. 8.
Pölar, laeunæ. 9. Gölar, fossæ inundatæ. The Mossar, paludes turfosæ, which
are of great extent, have but two species: 1. Torfmossar, called also Mossmyror
and Snottermyror, and, 2. Björnmossar.
The accumulations of stagnant or stagnating water originating in bogs are
distinguished into Trāsk, stagna, and Tjernar or Tjärnar (sing. Tjern or Tjärn),
stagnatiles. Trāsk are pools fed by bogs, or water emanating from them, and their
bottoms are slimy; Tjernar are small Träsk situated within the limits of Mossar.
—L. L. Læstadius, om Möjligheten af Uppodlingar i Lappmarken, pp. 23, 24.
[19] 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
Page 375
surface of Ireland is composed of bogs, and there are still extensive tracts of
undrained marsh in England.
Bogs, independently of their importance in geology as explaining the origin
of some kinds of mineral coal, have a present value as repositories of fuel. 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 on an acre cannot be increased
beyond the amount just stated; peat is indestructible, and the beds are always
growing.
[20] "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 mètres, 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 Steenstrup 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 grows 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, Bögens Indvandring, pp. 39, 40.
[21] Careful examination of the peat mosses in North Sjælland—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 toward the bottom of the valley.
—Vaupell, Bögens Indvandring i de Danske Skove, pp. 10, 14.
[22] 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 most 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
undrained marsh in England.
Bogs, independently of their importance in geology as explaining the origin
of some kinds of mineral coal, have a present value as repositories of fuel. 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 on an acre cannot be increased
beyond the amount just stated; peat is indestructible, and the beds are always
growing.
[20] "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 mètres, 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 Steenstrup 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 grows 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, Bögens Indvandring, pp. 39, 40.
[21] Careful examination of the peat mosses in North Sjælland—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 toward the bottom of the valley.
—Vaupell, Bögens Indvandring i de Danske Skove, pp. 10, 14.
[22] 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 most 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
Page 376
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 the garden walls of the same countries do on the ordinary
roads. See Appendix, No. 4.
[23] 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 trees, the shrubs 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. In a wood 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 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 tress 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. See
Appendix, No. 5.
[24] 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 horns; the buffalo of North America for his skin or
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 the garden walls of the same countries do on the ordinary
roads. See Appendix, No. 4.
[23] 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 trees, the shrubs 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. In a wood 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 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 tress 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. See
Appendix, No. 5.
[24] 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 horns; the buffalo of North America for his skin or
Page 377
his tongue; the elephant, the walrus, and the narwhal for their tusks; the cetacea,
and some other marine animals, for their oil and whalebone; 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, 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.
One of the greatest benefits to be expected from the improvements of
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.
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 from 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 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. 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.
[25] It is an interesting and not hitherto sufficiently noticed fact, that the
domestication of the organic world, so far 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. 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
and some other marine animals, for their oil and whalebone; 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, 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.
One of the greatest benefits to be expected from the improvements of
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.
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 from 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 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. 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.
[25] It is an interesting and not hitherto sufficiently noticed fact, that the
domestication of the organic world, so far 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. 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
Page 378
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.
In almost every wild tribe, some particular quadruped or bird, though
persecuted as a destroyer of more domestic beasts, 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 Mœnds Styrke og tolv Mœnds 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. Drummond Hay's
very interesting work on Morocco contains many amusing notices of a similar
feeling entertained by the Moors toward 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 teaches the brute to select the nutritious and to reject
the noxious vegetables indiscriminately mixed in forest and pasture?
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 themselves from
them. See Brémontier, Mémoire sur les Dunes, Annales des Ponts et Chaussées,
1833: premier sémestre, 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 years ago are no longer respected by the plunderers of the
cornfield, and new terrors must from time to time be invented for its protection.
See Appendix, No. 6.
to birds, quadrupeds, insects, flowers, and trees, is one of the earliest forms of
literary composition.
In almost every wild tribe, some particular quadruped or bird, though
persecuted as a destroyer of more domestic beasts, 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 Mœnds Styrke og tolv Mœnds 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. Drummond Hay's
very interesting work on Morocco contains many amusing notices of a similar
feeling entertained by the Moors toward 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 teaches the brute to select the nutritious and to reject
the noxious vegetables indiscriminately mixed in forest and pasture?
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 themselves from
them. See Brémontier, Mémoire sur les Dunes, Annales des Ponts et Chaussées,
1833: premier sémestre, 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 years ago are no longer respected by the plunderers of the
cornfield, and new terrors must from time to time be invented for its protection.
See Appendix, No. 6.
Page 379
Civilization has added little to the number of vegetable or animal species
grown in our fields or bred in our folds, 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.
[26] 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 afterward by the far less
developed Indian tribes. When the tillers of the fields, which must have 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.
[27] There is a possible—but only a possible—exception in the case of the
American bison. See note on that subject in chap. iii, post.
[28] 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.
[29] ——"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 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."
grown in our fields or bred in our folds, 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.
[26] 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 afterward by the far less
developed Indian tribes. When the tillers of the fields, which must have 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.
[27] There is a possible—but only a possible—exception in the case of the
American bison. See note on that subject in chap. iii, post.
[28] 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.
[29] ——"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 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."
Page 380
[30] 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 the proposed gigantic scheme
of draining the Zuiderzee in Holland, is that of procuring brushwood for the
fascines to be employed in the embankments. See Diggelen's pamphlet, "Groote
Werken in Nederland."
[31] 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, found this force equal to three tons per foot.
The seaward front of the breakwater at Cherbourg exposes a surface of 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, as 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.
[32] 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 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
Herschel cooked the materials for a family dinner by a similar process, using,
however, but a 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, and even in more northerly climates?
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
accumulated heat of the sun.
[33] In the successive stages of social progress, the most destructive periods
of human action upon nature are the pastoral condition, and that of incipient
stationary civilization, or, in the newly discovered countries of modern
geography, the colonial, which corresponds to the era of early civilization in
older lands. In more advanced states of culture, conservative influences make
themselves felt; and if highly civilized communities do not always restore the
works of nature, they at least use a less wasteful expenditure than their
predecessors in consuming them.
arduous material works, is curiously illustrated by the fact that one of the most
serious difficulties to be encountered in executing the proposed gigantic scheme
of draining the Zuiderzee in Holland, is that of procuring brushwood for the
fascines to be employed in the embankments. See Diggelen's pamphlet, "Groote
Werken in Nederland."
[31] 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, found this force equal to three tons per foot.
The seaward front of the breakwater at Cherbourg exposes a surface of 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, as 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.
[32] 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 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
Herschel cooked the materials for a family dinner by a similar process, using,
however, but a 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, and even in more northerly climates?
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
accumulated heat of the sun.
[33] In the successive stages of social progress, the most destructive periods
of human action upon nature are the pastoral condition, and that of incipient
stationary civilization, or, in the newly discovered countries of modern
geography, the colonial, which corresponds to the era of early civilization in
older lands. In more advanced states of culture, conservative influences make
themselves felt; and if highly civilized communities do not always restore the
works of nature, they at least use a less wasteful expenditure than their
predecessors in consuming them.
Page 381
[34] 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 are covered with earth which becomes
itself 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.
This point is fully considered by the authors referred to in chap. iii, post.
[35] 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.
[36] The general law of temperature is that it decreases as we ascend. But, in
hilly regions, 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 meteorological observations. The descent of the cold air and the
rise of the warm affect the relative temperatures of hills and valleys to a much
greater extent than has been usually supposed. A gentleman well known to me
kept a thermometrical record for nearly half a century, in a New England country
town, at an elevation of at least 1,500 feet above the sea. During these years his
thermometer never fell lower than 26° Fahrenheit, while at the shire town of the
county, situated in a basin one thousand feet lower, and ten miles distant, as well
as at other points in similar positions, the mercury froze several times in the
same period.
[37] 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 feet 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.
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 are covered with earth which becomes
itself 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.
This point is fully considered by the authors referred to in chap. iii, post.
[35] 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.
[36] The general law of temperature is that it decreases as we ascend. But, in
hilly regions, 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 meteorological observations. The descent of the cold air and the
rise of the warm affect the relative temperatures of hills and valleys to a much
greater extent than has been usually supposed. A gentleman well known to me
kept a thermometrical record for nearly half a century, in a New England country
town, at an elevation of at least 1,500 feet above the sea. During these years his
thermometer never fell lower than 26° Fahrenheit, while at the shire town of the
county, situated in a basin one thousand feet lower, and ten miles distant, as well
as at other points in similar positions, the mercury froze several times in the
same period.
[37] 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 feet 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.
Page 382
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 most of
his opportunity, without inquiring too nicely whether his 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. Similar
evils have become almost equally rife in England, and on the Continent; and I
believe the decay of commercial morality, and indeed 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, 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
guaranties 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 these institutions 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
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 most of
his opportunity, without inquiring too nicely whether his 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. Similar
evils have become almost equally rife in England, and on the Continent; and I
believe the decay of commercial morality, and indeed 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, 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
guaranties 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 these institutions 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
Page 383
composed of ultra-democratic elements, may become most dangerous enemies to
rational liberty, to the moral interests of the commonwealth, to the purity of
legislation and of judicial action, and to the sacredness of private rights.
[38] 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 part due to the fact
that, at this 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.
[39] 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 been brought from the Black Sea, by way of
Constantinople, about the eleventh or twelfth century. No vines of such
dimensions are now 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.
[40] The Northmen who—as I think it has been indisputably established by
Professor Rafn of Copenhagen—visited the coast of Massachusetts about the
year 1000, found grapes growing there in profusion, and the 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, and I have never seen a region which produced them so freely. I
have no doubt that the cultivation of the grape will become, at no distant day, one
of the most important branches of rural industry in that district.
[41] Les États Unis d'Amérique en 1863, p. 360. 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 1850, schedule 4,
§§ 2, 3.
rational liberty, to the moral interests of the commonwealth, to the purity of
legislation and of judicial action, and to the sacredness of private rights.
[38] 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 part due to the fact
that, at this 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.
[39] 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 been brought from the Black Sea, by way of
Constantinople, about the eleventh or twelfth century. No vines of such
dimensions are now 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.
[40] The Northmen who—as I think it has been indisputably established by
Professor Rafn of Copenhagen—visited the coast of Massachusetts about the
year 1000, found grapes growing there in profusion, and the 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, and I have never seen a region which produced them so freely. I
have no doubt that the cultivation of the grape will become, at no distant day, one
of the most important branches of rural industry in that district.
[41] Les États Unis d'Amérique en 1863, p. 360. 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 1850, schedule 4,
§§ 2, 3.
Page 384
[42] Cotton, though cultivated in Asia and Africa from the remotest antiquity,
and known as a rare and costly product to the Latins and the Greeks, was not
used by them to any considerable extent, nor did it enter into their commerce as a
regular article 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. Cotton seed was sown
in Virginia as early as 1621, but was not cultivated with a view to profit for more
than a century afterward. Sea-island cotton was first grown on the coast of
Georgia in 1786, the seed having been brought from the Bahamas, where it had
been introduced from Anguilla.—Bigelow, Les États Unis en 1863, p. 370.
[43] 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. Tea is
now cultivated with a certain success in Brazil, and promises to become an
important crop in the Southern States of the American Union. The lemon is, I
think, readily recognizable, by Pliny's description, as known to the ancients, but
it does not satisfactorily appear that they were acquainted with the orange.
and known as a rare and costly product to the Latins and the Greeks, was not
used by them to any considerable extent, nor did it enter into their commerce as a
regular article 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. Cotton seed was sown
in Virginia as early as 1621, but was not cultivated with a view to profit for more
than a century afterward. Sea-island cotton was first grown on the coast of
Georgia in 1786, the seed having been brought from the Bahamas, where it had
been introduced from Anguilla.—Bigelow, Les États Unis en 1863, p. 370.
[43] 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. Tea is
now cultivated with a certain success in Brazil, and promises to become an
important crop in the Southern States of the American Union. The lemon is, I
think, readily recognizable, by Pliny's description, as known to the ancients, but
it does not satisfactorily appear that they were acquainted with the orange.
Page 385
[44] 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 the pumpkin and several other 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. See Appendix, No. 8.
[45] There are some usages of polite society which are inherently low in
themselves, and debasing in their influence and tendency, and which no custom
or fashion can make respectable or fit to be followed by self-respecting persons.
It is essentially vulgar to smoke or chew tobacco, and especially to take snuff; it
is unbecoming a gentleman, to perform the duties of his coachman; it is
indelicate in a lady to wear in the street skirts so long that she cannot walk
without grossly soiling them. Not that all these things are not practised by
persons justly regarded as gentlemen and ladies; but the same individuals would
be, and feel themselves to be, much more emphatically gentlemen and ladies, if
they abstained from them.
[46] The name portogallo, so generally applied to the 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.
A correspondent of the Athenæum, in describing the newly excavated villa,
which has been named Livia's Villa, near the Porta del Popolo at Rome, states
that: "The walls of one of the rooms are, singularly enough, decorated with
landscape paintings, a grove of palm and orange trees, with fruits and birds on
the branches—the colors all as fresh and lively as if painted yesterday." The
writer remarks on the character of this decoration as something very unusual in
Roman architecture; and if the trees in question are really orange, and not lemon
trees, this circumstance may throw some doubt on the antiquity of the painting.
If, on the other hand, it proves really ancient, it shows that the orange was known
to the Roman painters, if not gardeners. The landscape may perhaps represent
Oriental, not European scenery. The accessories of the picture would probably
determine that question.—Athenæum, No. 1859, June 13, 1863.
Müller, Das Buch der Pflanzenwelt, 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-Montélimart.
[47] The vegetables which, so far as we know their history, seem to have
been longest the objects of human care, can, by painstaking industry, be made to
grow under a great variety of circumstances, and some of them—the vine for
instance—prosper nearly equally well, when planted and tended, on soils of
almost any geological character; but their seeds 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. In range of climate, wild
as having been cultivated by the natives before the arrival of the whites, and
there is no doubt, I believe, that the pumpkin and several other 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. See Appendix, No. 8.
[45] There are some usages of polite society which are inherently low in
themselves, and debasing in their influence and tendency, and which no custom
or fashion can make respectable or fit to be followed by self-respecting persons.
It is essentially vulgar to smoke or chew tobacco, and especially to take snuff; it
is unbecoming a gentleman, to perform the duties of his coachman; it is
indelicate in a lady to wear in the street skirts so long that she cannot walk
without grossly soiling them. Not that all these things are not practised by
persons justly regarded as gentlemen and ladies; but the same individuals would
be, and feel themselves to be, much more emphatically gentlemen and ladies, if
they abstained from them.
[46] The name portogallo, so generally applied to the 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.
A correspondent of the Athenæum, in describing the newly excavated villa,
which has been named Livia's Villa, near the Porta del Popolo at Rome, states
that: "The walls of one of the rooms are, singularly enough, decorated with
landscape paintings, a grove of palm and orange trees, with fruits and birds on
the branches—the colors all as fresh and lively as if painted yesterday." The
writer remarks on the character of this decoration as something very unusual in
Roman architecture; and if the trees in question are really orange, and not lemon
trees, this circumstance may throw some doubt on the antiquity of the painting.
If, on the other hand, it proves really ancient, it shows that the orange was known
to the Roman painters, if not gardeners. The landscape may perhaps represent
Oriental, not European scenery. The accessories of the picture would probably
determine that question.—Athenæum, No. 1859, June 13, 1863.
Müller, Das Buch der Pflanzenwelt, 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-Montélimart.
[47] The vegetables which, so far as we know their history, seem to have
been longest the objects of human care, can, by painstaking industry, be made to
grow under a great variety of circumstances, and some of them—the vine for
instance—prosper nearly equally well, when planted and tended, on soils of
almost any geological character; but their seeds 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. In range of climate, wild
Page 386
plants are much more limited than domestic, but much less so with regard to the
state of the soil in which they germinate and grow. See Appendix, No. 9.
Dr. Dwight remarks that the seeds of American forest trees will not vegetate
when dropped on grassland. This is one of the very few errors of personal
observation to be found in that author's writings. There are seasons, indeed, when
few tree seeds germinate in the meadows and the pastures, and years favorable to
one species are not always propitious to another; but there is no American forest
tree known to me which does not readily propagate itself by seed in the thickest
greensward, if its germs are not disturbed by man or animals.
[48] 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.
[49] 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 afterward, by the
rank weeds which cover it, though no others of the same species are found for
miles.
"Mediæval 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—lægekulsukker and snake-root,
which grow only where there were convents and other dwellings in the Middle
Ages."—Bögens Indvandring i de Danske Skove, pp. 1, 2.
[50] Vaupell, Bögens Indvandring i de Danske Skove, p. 2.
[51] It is, I believe, nearly certain that the Turks inflicted tobacco upon
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.
[52] Accidents sometimes limit, as well as promote, the propagation of
foreign vegetables in countries new to them. The Lombardy poplar is a diœcious
state of the soil in which they germinate and grow. See Appendix, No. 9.
Dr. Dwight remarks that the seeds of American forest trees will not vegetate
when dropped on grassland. This is one of the very few errors of personal
observation to be found in that author's writings. There are seasons, indeed, when
few tree seeds germinate in the meadows and the pastures, and years favorable to
one species are not always propitious to another; but there is no American forest
tree known to me which does not readily propagate itself by seed in the thickest
greensward, if its germs are not disturbed by man or animals.
[48] 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.
[49] 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 afterward, by the
rank weeds which cover it, though no others of the same species are found for
miles.
"Mediæval 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—lægekulsukker and snake-root,
which grow only where there were convents and other dwellings in the Middle
Ages."—Bögens Indvandring i de Danske Skove, pp. 1, 2.
[50] Vaupell, Bögens Indvandring i de Danske Skove, p. 2.
[51] It is, I believe, nearly certain that the Turks inflicted tobacco upon
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.
[52] Accidents sometimes limit, as well as promote, the propagation of
foreign vegetables in countries new to them. The Lombardy poplar is a diœcious
Page 387
tree, and is very easily grown from cuttings. In most of the countries into which
it has been introduced the cuttings have 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. See Appendix, No. 10.
[53] Tempests, violent enough to destroy all cultivated plants, often spare
those of spontaneous growth. During the present summer, I have 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 wayside, passed
through the ordeal with scarcely the loss of a leaflet.
[54] The boar spear is provided with a short crossbar, to enable the hunter to
keep the infuriated animal at bay after he has transfixed him.
[55] 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 easily
cultivated in Egypt, to any extent, if there were any special motive for
encouraging its growth.
[56] Although it is not known that man has 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—whether in this
case the malady resides in the mulberry or in the insect—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. This change has been thought to favor the multiplication of the obscure
parasites which cause the injury to the vegetables just 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, if not universally, regarded as vegetable, and if they are so, Babinet's
theory would be even more plausible than on his own supposition.—Études 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 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
it has been introduced the cuttings have 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. See Appendix, No. 10.
[53] Tempests, violent enough to destroy all cultivated plants, often spare
those of spontaneous growth. During the present summer, I have 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 wayside, passed
through the ordeal with scarcely the loss of a leaflet.
[54] The boar spear is provided with a short crossbar, to enable the hunter to
keep the infuriated animal at bay after he has transfixed him.
[55] 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 easily
cultivated in Egypt, to any extent, if there were any special motive for
encouraging its growth.
[56] Although it is not known that man has 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—whether in this
case the malady resides in the mulberry or in the insect—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. This change has been thought to favor the multiplication of the obscure
parasites which cause the injury to the vegetables just 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, if not universally, regarded as vegetable, and if they are so, Babinet's
theory would be even more plausible than on his own supposition.—Études 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 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
Page 388
crisis has been, on the whole, rather advantageous than detrimental to the
country."—Économie Rurale de la France, pp. 263, 264.
France produces a considerable 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 even, it is said, 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 wine.—
Waltershausen, Ueber den Sicilianischen Ackerbau, pp. 19, 20.
[57] Some recent observations of the learned traveller Wetzstein are worthy
of special notice. "The soil of the Haurân," 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 über Haurân und
die Trachonen, p. 40.
[58] 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. 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 trees, and is
particularly suited for grafting. See Salvagnoli, Memorie sulle Maremme, pp.
63-73. See Appendix, No. 12.
Fraas, Klima und Pflanzenwelt in der Zeit, pp. 35-38, gives, upon the
authority of Link and other botanical writers, a list of the native habitats of most
cereals and of many fruits, or at least of localities where these plants are said to
country."—Économie Rurale de la France, pp. 263, 264.
France produces a considerable 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 even, it is said, 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 wine.—
Waltershausen, Ueber den Sicilianischen Ackerbau, pp. 19, 20.
[57] Some recent observations of the learned traveller Wetzstein are worthy
of special notice. "The soil of the Haurân," 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 über Haurân und
die Trachonen, p. 40.
[58] 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. 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 trees, and is
particularly suited for grafting. See Salvagnoli, Memorie sulle Maremme, pp.
63-73. See Appendix, No. 12.
Fraas, Klima und Pflanzenwelt in der Zeit, pp. 35-38, gives, upon the
authority of Link and other botanical writers, a list of the native habitats of most
cereals and of many fruits, or at least of localities where these plants are said to
Page 389
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, but 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 following are interesting incidents: "A negro slave of the great
Cortez 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. In
the Franciscan monastery at Quito, I saw the earthen pot which contained the
first wheat sown there by Friar Jodoco Rixi, of Ghent. It was preserved as a
relic."
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 laws 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.
[59] 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 1860, as we shall see hereafter, nearly one
hundred and two 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 those cattle may amount to two thirds as many as
those of the United States, and thus we have in North America a total of
170,000,000 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 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;
trustworthy evidence. Theoretically, there can be little doubt that all our
cultivated plants are modified forms of spontaneous vegetation, but 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 following are interesting incidents: "A negro slave of the great
Cortez 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. In
the Franciscan monastery at Quito, I saw the earthen pot which contained the
first wheat sown there by Friar Jodoco Rixi, of Ghent. It was preserved as a
relic."
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 laws 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.
[59] 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 1860, as we shall see hereafter, nearly one
hundred and two 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 those cattle may amount to two thirds as many as
those of the United States, and thus we have in North America a total of
170,000,000 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 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;
Page 390
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 couple of feet beneath the surface. The grave is respected as long as
the tombstone remains, but the sepultures 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, if 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.
[60] It is asserted that the bones of mammoths and mastodons, in many
instances, appear to have been grazed or cut by flint arrow-heads or other stone
weapons. 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 highly probable, if not certain, that this
conclusion has been too hastily adopted. Lyell observes: "These stories * * must
in future be more carefully inquired into, for we can scarcely doubt that the
mastodon in North America lived down to a period when the mammoth
coexisted with man in Europe."—Antiquity of Man, p. 354.
On page 143 of the volume just quoted, the same very distinguished writer
remarks that man "no doubt played his part in hastening the era of the extinction"
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.
[61] 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
marvellously cherishing."—Terra, or Philosophical Discourse of Earth, p. 36.
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 couple of feet beneath the surface. The grave is respected as long as
the tombstone remains, but the sepultures 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, if 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.
[60] It is asserted that the bones of mammoths and mastodons, in many
instances, appear to have been grazed or cut by flint arrow-heads or other stone
weapons. 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 highly probable, if not certain, that this
conclusion has been too hastily adopted. Lyell observes: "These stories * * must
in future be more carefully inquired into, for we can scarcely doubt that the
mastodon in North America lived down to a period when the mammoth
coexisted with man in Europe."—Antiquity of Man, p. 354.
On page 143 of the volume just quoted, the same very distinguished writer
remarks that man "no doubt played his part in hastening the era of the extinction"
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.
[61] 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
marvellously cherishing."—Terra, or Philosophical Discourse of Earth, p. 36.
Page 391
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.
[62] The rat and the mouse, though not voluntarily transported, are
passengers by every ship that sails from Europe to 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. I believe as
many might almost be found in a single palace in modern Rome. 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.
[63] Bigelow, Les États Unis en 1863, pp. 379, 380. In the same paragraph
this volume states the number of animals slaughtered in the United States by
butchers, in 1859, at 212,871,653. This is an error of the press. Number is
confounded with value. A reference to the tables of the census shows that the
animals slaughtered that year were estimated at 212,871,653 dollars; the number
of head is not given. The wild horses and horned cattle of the prairies and the
horses of the Indians are not included in the returns.
[64] Of this total number, 2,240,000, or nearly nine per cent., are reported as
working oxen. This would strike European, and especially English agriculturists,
as a large proportion; but it is explained by the difference between a new country
and an old, in the conditions which determine the employment of animal labor.
Oxen are very generally used in the United States and Canada for hauling timber
and firewood through and from the forests; for ploughing in ground still full of
rocks, stumps, and roots; for breaking up the new soil of the prairies with its
strong matting of native grasses, and for the transportation of heavy loads over
the rough roads of the interior. In all these cases, the frequent obstructions to the
passage of the timber, the plough, and the sled or cart, are a source of constant
danger to the animals, the vehicles, and the harness, and the slow and steady step
of the ox is attended with much less risk than the swift and sudden movements of
the impatient horse. It is surprising to see the sagacity with which the dull and
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.
[62] The rat and the mouse, though not voluntarily transported, are
passengers by every ship that sails from Europe to 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. I believe as
many might almost be found in a single palace in modern Rome. 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.
[63] Bigelow, Les États Unis en 1863, pp. 379, 380. In the same paragraph
this volume states the number of animals slaughtered in the United States by
butchers, in 1859, at 212,871,653. This is an error of the press. Number is
confounded with value. A reference to the tables of the census shows that the
animals slaughtered that year were estimated at 212,871,653 dollars; the number
of head is not given. The wild horses and horned cattle of the prairies and the
horses of the Indians are not included in the returns.
[64] Of this total number, 2,240,000, or nearly nine per cent., are reported as
working oxen. This would strike European, and especially English agriculturists,
as a large proportion; but it is explained by the difference between a new country
and an old, in the conditions which determine the employment of animal labor.
Oxen are very generally used in the United States and Canada for hauling timber
and firewood through and from the forests; for ploughing in ground still full of
rocks, stumps, and roots; for breaking up the new soil of the prairies with its
strong matting of native grasses, and for the transportation of heavy loads over
the rough roads of the interior. In all these cases, the frequent obstructions to the
passage of the timber, the plough, and the sled or cart, are a source of constant
danger to the animals, the vehicles, and the harness, and the slow and steady step
of the ox is attended with much less risk than the swift and sudden movements of
the impatient horse. It is surprising to see the sagacity with which the dull and
Page 392
clumsy ox—hampered as he is by the rigid yoke, the most absurd implement of
draught ever contrived by man—picks his way, when once trained to forest
work, among rocks and roots, and even climbs over fallen trees, not only moving
safely, but drawing timber over ground wholly impracticable for the light and
agile horse.
Cows, so constantly employed for draught in Italy, are never yoked or
otherwise used for labor in America, except in the Slave States.
[65] "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."—Stevens'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.
[66] The most zealous and successful New England hunter of whom I have
any personal knowledge, and who continued to indulge his favorite passion
much beyond the age which generally terminates exploits in woodcraft, lamented
on his deathbed that he had not lived long enough to carry up the record of his
slaughtered deer to the number of one thousand, which he had fixed as the limit
of his ambition. He was able to handle the rifle, for sixty years, at a period when
the game was still nearly as abundant as ever, but had killed only nine hundred
and sixty of these quadrupeds, of all species. The exploits of this Nimrod have
been far exceeded by prairie hunters, but I doubt whether, in the originally
wooded territory of the Union, any single marksman has brought down a larger
number.
[67] Erdkunde, viii. Asien, 1ste Abtheilung, pp. 660, 758.
[68] 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. 489. This is a fact of much interest,
because it is, I believe, the only known instance 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.
[69] In maintaining the recent existence of the lion in the countries named in
the text, naturalists have, perhaps, laid too much weight on the frequent
draught ever contrived by man—picks his way, when once trained to forest
work, among rocks and roots, and even climbs over fallen trees, not only moving
safely, but drawing timber over ground wholly impracticable for the light and
agile horse.
Cows, so constantly employed for draught in Italy, are never yoked or
otherwise used for labor in America, except in the Slave States.
[65] "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."—Stevens'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.
[66] The most zealous and successful New England hunter of whom I have
any personal knowledge, and who continued to indulge his favorite passion
much beyond the age which generally terminates exploits in woodcraft, lamented
on his deathbed that he had not lived long enough to carry up the record of his
slaughtered deer to the number of one thousand, which he had fixed as the limit
of his ambition. He was able to handle the rifle, for sixty years, at a period when
the game was still nearly as abundant as ever, but had killed only nine hundred
and sixty of these quadrupeds, of all species. The exploits of this Nimrod have
been far exceeded by prairie hunters, but I doubt whether, in the originally
wooded territory of the Union, any single marksman has brought down a larger
number.
[67] Erdkunde, viii. Asien, 1ste Abtheilung, pp. 660, 758.
[68] 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. 489. This is a fact of much interest,
because it is, I believe, the only known instance 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.
[69] In maintaining the recent existence of the lion in the countries named in
the text, naturalists have, perhaps, laid too much weight on the frequent
Page 393
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.
[70]
Dar nach sloger schiere, einen wisent bat
elch.
Starcher bore biere. but einen grimmen
schelch.
XVI
Auentiure.
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 mediæval Germany.
[71] 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.
[72] The wood pigeon has been observed to increase in numbers in Europe
also, when pains have been taken to exterminate the hawk. The 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.
[73] 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.
[74] Professor Treadwell, of Massachusetts, found that a half-grown
American robin in confinement ate in one day sixty-eight earthworms, 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
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.
[70]
Dar nach sloger schiere, einen wisent bat
elch.
Starcher bore biere. but einen grimmen
schelch.
XVI
Auentiure.
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 mediæval Germany.
[71] 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.
[72] The wood pigeon has been observed to increase in numbers in Europe
also, when pains have been taken to exterminate the hawk. The 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.
[73] 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.
[74] Professor Treadwell, of Massachusetts, found that a half-grown
American robin in confinement ate in one day sixty-eight earthworms, 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
Page 394
the nest; for the old birds did not return with worms or insects oftener than once
in ten minutes on an average. If 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.
[75] I hope Michelet has good authority for this statement, but I am unable to
confirm it.
[76] Apropos of the sparrow—a single pair of which, according to Michelet,
p. 315, carries to the nest four thousand and three hundred caterpillars or
coleoptera in a week—I take from the Record, an English religious newspaper,
of December 15, 1862, the following article communicated to a country paper by
a person who signs himself "A real friend to the farmer:"
"Crawley Sparrow Club.—The annual dinner took place at the George Inn on
Wednesday last. The first prize was awarded to Mr. I. Redford, Worth, having
destroyed within the last year 1,467. Mr. Heayman took the second with 1,448
destroyed. Mr. Stone, third, with 982 affixed. Total destroyed, 11,944. Old birds,
8,663; young ditto, 722; eggs, 2,556."
This trio of valiant fowlers, and their less fortunate—or rather less
unfortunate, but not therefore less guilty—associates, have rescued by their
prowess, it may be, a score of pecks of grain from being devoured by the
voracious sparrow, but every one of the twelve 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. Mr. Redford,
Mr. Heayman, and Mr. Stone ought to contribute the value of the bread they have
wasted to the fund for the benefit of the Lancashire weavers; and it is to be
hoped that the next Byron will satirize the sparrowcide as severely as the first did
the prince of anglers, Walton, in the well known lines:
in ten minutes on an average. If 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.
[75] I hope Michelet has good authority for this statement, but I am unable to
confirm it.
[76] Apropos of the sparrow—a single pair of which, according to Michelet,
p. 315, carries to the nest four thousand and three hundred caterpillars or
coleoptera in a week—I take from the Record, an English religious newspaper,
of December 15, 1862, the following article communicated to a country paper by
a person who signs himself "A real friend to the farmer:"
"Crawley Sparrow Club.—The annual dinner took place at the George Inn on
Wednesday last. The first prize was awarded to Mr. I. Redford, Worth, having
destroyed within the last year 1,467. Mr. Heayman took the second with 1,448
destroyed. Mr. Stone, third, with 982 affixed. Total destroyed, 11,944. Old birds,
8,663; young ditto, 722; eggs, 2,556."
This trio of valiant fowlers, and their less fortunate—or rather less
unfortunate, but not therefore less guilty—associates, have rescued by their
prowess, it may be, a score of pecks of grain from being devoured by the
voracious sparrow, but every one of the twelve 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. Mr. Redford,
Mr. Heayman, and Mr. Stone ought to contribute the value of the bread they have
wasted to the fund for the benefit of the Lancashire weavers; and it is to be
hoped that the next Byron will satirize the sparrowcide as severely as the first did
the prince of anglers, Walton, in the well known lines:
Page 395
"The quaint, old, cruel coxcomb in his gullet
Should have a hook, and a small trout to pull it."
[77] 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 in to the nets by throwing
stones over them. See Appendix, No. 14.
Tschudi has collected in his little work, Ueber die Landwirthschaftliche
Bedeutung der Vögel, 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
mole are among the most frequent causes of rupture in the dikes of the Po, and,
consequently, of inundations which lay many square miles under water.—
Annales des Ponts et Chaussées, 1847, 1re sémestre, p. 150. See also Vogt,
Nützliche u. schädliche Thiere.
[78] Wild birds are very tenacious in their habits. The extension of particular
branches of agriculture introduces new birds; 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 Bosphorus, 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. See App. No.
15.
[79] 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 humming
bird 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.
[80] Lyell, Antiquity of Man, p. 409, 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."
Should have a hook, and a small trout to pull it."
[77] 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 in to the nets by throwing
stones over them. See Appendix, No. 14.
Tschudi has collected in his little work, Ueber die Landwirthschaftliche
Bedeutung der Vögel, 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
mole are among the most frequent causes of rupture in the dikes of the Po, and,
consequently, of inundations which lay many square miles under water.—
Annales des Ponts et Chaussées, 1847, 1re sémestre, p. 150. See also Vogt,
Nützliche u. schädliche Thiere.
[78] Wild birds are very tenacious in their habits. The extension of particular
branches of agriculture introduces new birds; 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 Bosphorus, 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. See App. No.
15.
[79] 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 humming
bird 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.
[80] Lyell, Antiquity of Man, p. 409, 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."
Page 396
A remarkable instance of the influence of new circumstances upon birds was
observed upon the establishment of a lighthouse 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. See Appendix, No. 16.
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.
[81] The cappercailzie, or tjäder, 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 Læstadius frequently
notices the tjäder, in his very remarkable account of the Swedish Laplanders—a
work wholly unsurpassed as a genial picture of semi-barbarian life, and not
inferior in minuteness of detail to Schlatter's description of the manners of the
Nogai Tartars, or even to Lane's admirable and exhaustive work on the Modern
Egyptians. The tjäder, 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 Læstadius, "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, toward 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 Læstadius, Journal af första året,
etc., p. 325.
observed upon the establishment of a lighthouse 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. See Appendix, No. 16.
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.
[81] The cappercailzie, or tjäder, 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 Læstadius frequently
notices the tjäder, in his very remarkable account of the Swedish Laplanders—a
work wholly unsurpassed as a genial picture of semi-barbarian life, and not
inferior in minuteness of detail to Schlatter's description of the manners of the
Nogai Tartars, or even to Lane's admirable and exhaustive work on the Modern
Egyptians. The tjäder, 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 Læstadius, "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, toward 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 Læstadius, Journal af första året,
etc., p. 325.
Page 397
[82] Die Herzogthümer Schleswig und Holstein, i, p. 203.
[83] 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.
[84] 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 follows 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 grow 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 spyglass. I suppose
he finished the voyage, for he certainly did not return to the palace.
[85] The enthusiasm of naturalists is not always proportioned to the
magnitude or importance of the organisms they concern themselves with. It is
not recorded that Adams, who found the colossal antediluvian pachyderm in a
thick-ribbed mountain of Siberian ice, ran wild over his trouvaille; but Schmidl,
in describing the natural history of the caves of the Karst, speaks of an eminent
entomologist as "der glückliche Entdecker," the happy discoverer of a new
coleopteron, in one of those dim caverns. How various are the sources of
happiness! Think of a learned German professor, the bare enumeration of whose
Rath-ships and scientific Mitglied-ships fills a page, made famous in the annals
of science, immortal, happy, by the discovery of a beetle! Had that imperial
ennuyé, who offered a premium for the invention of a new pleasure, but read
Schmidl's Höhlen des Karstes, what splendid rewards would he not have heaped
upon Kirby and Spence!
[86] 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
[83] 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.
[84] 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 follows 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 grow 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 spyglass. I suppose
he finished the voyage, for he certainly did not return to the palace.
[85] The enthusiasm of naturalists is not always proportioned to the
magnitude or importance of the organisms they concern themselves with. It is
not recorded that Adams, who found the colossal antediluvian pachyderm in a
thick-ribbed mountain of Siberian ice, ran wild over his trouvaille; but Schmidl,
in describing the natural history of the caves of the Karst, speaks of an eminent
entomologist as "der glückliche Entdecker," the happy discoverer of a new
coleopteron, in one of those dim caverns. How various are the sources of
happiness! Think of a learned German professor, the bare enumeration of whose
Rath-ships and scientific Mitglied-ships fills a page, made famous in the annals
of science, immortal, happy, by the discovery of a beetle! Had that imperial
ennuyé, who offered a premium for the invention of a new pleasure, but read
Schmidl's Höhlen des Karstes, what splendid rewards would he not have heaped
upon Kirby and Spence!
[86] 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
Page 398
one can hardly turn over a shovelful 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, 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.
[87] I have already remarked that the remains of extant animals are rarely, if
ever, gathered in sufficient quantities to possess any geographical importance by
their mere mass; but the decayed exuviæ of even the smaller and humbler forms
of life are sometimes abundant enough to exercise a perceptible influence on soil
and atmosphere. "The plain of Cumana," says 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 cabiaï, 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."
[88] It is remarkable that Palissy, 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 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 unto 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."
[89] Between the years 1851 and 1853, both inclusive, the United States
exported 2,665,857 pounds of beeswax, besides a considerable quantity
employed in the manufacture of candles for exportation. This is an average of
more than 330,000 pounds per year. The census of 1850 gave the total
production of wax and honey for that year at 14,853,128 pounds. In 1860, it
amounted to 26,370,813 pounds, the increase being partly due to the introduction
of improved races of bees from Italy and Switzerland.—BIGELOW, Les États
Unis en 1863, p. 376.
unearthing several of them. A very intelligent lady, born in the woods of
Northern New England, told me that, 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.
[87] I have already remarked that the remains of extant animals are rarely, if
ever, gathered in sufficient quantities to possess any geographical importance by
their mere mass; but the decayed exuviæ of even the smaller and humbler forms
of life are sometimes abundant enough to exercise a perceptible influence on soil
and atmosphere. "The plain of Cumana," says 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 cabiaï, 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."
[88] It is remarkable that Palissy, 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 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 unto 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."
[89] Between the years 1851 and 1853, both inclusive, the United States
exported 2,665,857 pounds of beeswax, besides a considerable quantity
employed in the manufacture of candles for exportation. This is an average of
more than 330,000 pounds per year. The census of 1850 gave the total
production of wax and honey for that year at 14,853,128 pounds. In 1860, it
amounted to 26,370,813 pounds, the increase being partly due to the introduction
of improved races of bees from Italy and Switzerland.—BIGELOW, Les États
Unis en 1863, p. 376.
Page 399
[90] 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.
[91] In many insects, some of the stages of life regularly continue for several
years, and they may, under peculiar circumstances, be almost indefinitely
prolonged. Dr. Dwight mentions the following remarkable case of this sort,
which may be new to many readers: "While I was here [at Williamstown, Mass.],
Dr. Fitch showed me an insect, about an inch in length, of a brown color tinged
with orange, with two antennæ, not unlike a rosebug. This insect came out of a
tea table, made of the boards of an apple tree." Dr. Dwight examined the table,
and found the "cavity whence the insect had emerged into the light," to be "about
two inches in length, nearly horizontal, and inclining upward very little, except
at the mouth. 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.
[92] It does not appear to be quite settled whether the termites of France are
indigenous or imported. See Quatrefages, Souvenirs d'un Naturaliste, ii, pp.
400, 542, 543.
[93] I have seen the larva of the dragon fly in an aquarium, bite off the head
of a young fish as long as itself.
[94] 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 Læstadius regard them as one of the great plagues of sub-Arctic life.
"The persecutions of these insects," says Lars Levi Læstadius [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 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 gnat, and the mosquito are
numerous."—Om Uppodlingar i Lappmarken, p. 50.
Petrus Læstadius makes similar statements in his Journal för första året, p.
285.
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.
[91] In many insects, some of the stages of life regularly continue for several
years, and they may, under peculiar circumstances, be almost indefinitely
prolonged. Dr. Dwight mentions the following remarkable case of this sort,
which may be new to many readers: "While I was here [at Williamstown, Mass.],
Dr. Fitch showed me an insect, about an inch in length, of a brown color tinged
with orange, with two antennæ, not unlike a rosebug. This insect came out of a
tea table, made of the boards of an apple tree." Dr. Dwight examined the table,
and found the "cavity whence the insect had emerged into the light," to be "about
two inches in length, nearly horizontal, and inclining upward very little, except
at the mouth. 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.
[92] It does not appear to be quite settled whether the termites of France are
indigenous or imported. See Quatrefages, Souvenirs d'un Naturaliste, ii, pp.
400, 542, 543.
[93] I have seen the larva of the dragon fly in an aquarium, bite off the head
of a young fish as long as itself.
[94] 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 Læstadius regard them as one of the great plagues of sub-Arctic life.
"The persecutions of these insects," says Lars Levi Læstadius [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 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 gnat, and the mosquito are
numerous."—Om Uppodlingar i Lappmarken, p. 50.
Petrus Læstadius makes similar statements in his Journal för första året, p.
285.
Page 400
[95] 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. 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 as 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.
[96] 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, 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. See Appendix, No. 18.
[97] 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.
[98] 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 chase at a period not
much later. I am not aware of any evidence to show that any of the Latin nations
engaged in this fishery until a century or two afterward, though it may not be
easy to disprove their earlier participation in it. In mediæval 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 in 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 Catalan tariffs. The whalebone of
the mediæval writers, which is described as very white, is doubtless the ivory of
the walrus or of the narwhale.
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. 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 as 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.
[96] 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, 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. See Appendix, No. 18.
[97] 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.
[98] 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 chase at a period not
much later. I am not aware of any evidence to show that any of the Latin nations
engaged in this fishery until a century or two afterward, though it may not be
easy to disprove their earlier participation in it. In mediæval 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 in 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 Catalan tariffs. The whalebone of
the mediæval writers, which is described as very white, is doubtless the ivory of
the walrus or of the narwhale.
Page 401
[99] 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 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 États 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 present number of American ships employed in that
fishery is 353.
[100] The Origin and History of the English Language, &c., pp. 423, 424.
[101] Among the unexpected results of human action, the destruction or
multiplication of fish, as well as of other animals, is a not unfrequent occurrence.
I shall have occasion to mention on a following page the extermination of the
fish in a Swedish river by a flood occasioned by the sudden discharge of the
waters of a pond. Williams, in his History of Vermont, i, p. 149, quoted in
Thompson's Natural History of Vermont, p. 142, records a case of the increase of
trout from an opposite cause. 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 increase
in the size of the trout was as remarkable as the multiplication of their numbers.
[102] Babinet, Études et Lectures, ii, pp. 108, 110.
[103] Thompson, Natural History of Vermont, p. 38, and Appendix, p. 13.
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.
[104] See page 89, note, ante.
[105] 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.
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 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 États 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 present number of American ships employed in that
fishery is 353.
[100] The Origin and History of the English Language, &c., pp. 423, 424.
[101] Among the unexpected results of human action, the destruction or
multiplication of fish, as well as of other animals, is a not unfrequent occurrence.
I shall have occasion to mention on a following page the extermination of the
fish in a Swedish river by a flood occasioned by the sudden discharge of the
waters of a pond. Williams, in his History of Vermont, i, p. 149, quoted in
Thompson's Natural History of Vermont, p. 142, records a case of the increase of
trout from an opposite cause. 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 increase
in the size of the trout was as remarkable as the multiplication of their numbers.
[102] Babinet, Études et Lectures, ii, pp. 108, 110.
[103] Thompson, Natural History of Vermont, p. 38, and Appendix, p. 13.
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.
[104] See page 89, note, ante.
[105] 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 402
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 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.
[106] The indiscriminate hostility of man to inferior forms of animated life is
little creditable to modern civilization, and it is painful to reflect that it becomes
keener and more unsparing in proportion to the refinement of the race. The
savage slays no animal, not even the rattlesnake, wantonly; and the Turk, whom
we call a barbarian, treats the dumb beast as gently as a child. One cannot live
many weeks in Turkey without witnessing touching instances of the kindness of
the people to the lower animals, and I have found it very difficult to induce even
the boys to catch lizards and other reptiles for preservation as specimens. See
Appendix, No. 19.
The fearless confidence in man, so generally manifested by wild animals in
newly discovered islands, ought to have inspired a gentler treatment of them; but
a very few years of the relentless pursuit, to which they are immediately
subjected, suffice to make them as timid as the wildest inhabitants of the
European forest. This timidity, however, may easily be overcome. The squirrels
introduced by Mayor Smith into the public parks of Boston are so tame as to
feed from the hands of passengers, and they not unfrequently enter the
neighboring houses.
[107] 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 Storsjö 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.—Resa genom Sverge, ii, p. 51.
[108] Wittwer, Physikalische Geographie, p. 142.
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 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.
[106] The indiscriminate hostility of man to inferior forms of animated life is
little creditable to modern civilization, and it is painful to reflect that it becomes
keener and more unsparing in proportion to the refinement of the race. The
savage slays no animal, not even the rattlesnake, wantonly; and the Turk, whom
we call a barbarian, treats the dumb beast as gently as a child. One cannot live
many weeks in Turkey without witnessing touching instances of the kindness of
the people to the lower animals, and I have found it very difficult to induce even
the boys to catch lizards and other reptiles for preservation as specimens. See
Appendix, No. 19.
The fearless confidence in man, so generally manifested by wild animals in
newly discovered islands, ought to have inspired a gentler treatment of them; but
a very few years of the relentless pursuit, to which they are immediately
subjected, suffice to make them as timid as the wildest inhabitants of the
European forest. This timidity, however, may easily be overcome. The squirrels
introduced by Mayor Smith into the public parks of Boston are so tame as to
feed from the hands of passengers, and they not unfrequently enter the
neighboring houses.
[107] 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 Storsjö 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.—Resa genom Sverge, ii, p. 51.
[108] Wittwer, Physikalische Geographie, p. 142.
Page 403
[109] To vary the phrase, I make occasional use of animalcule, 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 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.
[110] 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. 360, 373.
[111] The fermentation of liquids, and in many cases the decomposition of
semi-solids, formerly supposed to be owing purely to chemical action, are now
ascertained to be due 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. See an interesting article
by Auguste Laugel on the recent researches of Pasteur, in the Revue des Deux
Mondes, for September 15th, 1863.
[112] The recorded evidence in support of the proposition in the text has
been collected by L. F. Alfred Maury, in his Histoire des grandes Forêts de la
Gaule et de l'ancienne France, and by Becquerel, in his important work, Des
climats et de l'Influence qu'exercent les Sols boisés et non boisés, 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, Brühl, -wald, -wold, -wood,
-shaw, -skeg, and -skov.
[113] The island of Madeira, whose noble forests were devastated by fire not
long after its colonization by European settlers, derives its name from the
Portuguese word for wood.
[114] 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," says Emsmann, in
the notes to his translation of Foissac, p. 654, "it was the goats which destroyed
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 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.
[110] 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. 360, 373.
[111] The fermentation of liquids, and in many cases the decomposition of
semi-solids, formerly supposed to be owing purely to chemical action, are now
ascertained to be due 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. See an interesting article
by Auguste Laugel on the recent researches of Pasteur, in the Revue des Deux
Mondes, for September 15th, 1863.
[112] The recorded evidence in support of the proposition in the text has
been collected by L. F. Alfred Maury, in his Histoire des grandes Forêts de la
Gaule et de l'ancienne France, and by Becquerel, in his important work, Des
climats et de l'Influence qu'exercent les Sols boisés et non boisés, 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, Brühl, -wald, -wold, -wood,
-shaw, -skeg, and -skov.
[113] The island of Madeira, whose noble forests were devastated by fire not
long after its colonization by European settlers, derives its name from the
Portuguese word for wood.
[114] 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," says Emsmann, in
the notes to his translation of Foissac, p. 654, "it was the goats which destroyed
Page 404
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.'"
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, who is above natural law, 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
Clavé, "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 their 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. See also Appendix, No. 21.
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, may 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.
[115] 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
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.'"
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, who is above natural law, 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
Clavé, "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 their 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. See also Appendix, No. 21.
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, may 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.
[115] 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
Page 405
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.
[116] A Relation of a Journey Begun An. Dom. 1610, lib. 4, p. 260, edition of
1627. The testimony of Sandys on this point is confirmed by that of Pighio,
Braccini, Magliocco, Salimbeni, and Nicola di Rubeo, 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 1631. 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 1139, ashes were thrown out for many days. I take those
dates from the work of Roth just cited.
[117] 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.
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.
The North American Indians did not inhabit the interior of the forests. Their
settlements 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 villages.
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
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.
[116] A Relation of a Journey Begun An. Dom. 1610, lib. 4, p. 260, edition of
1627. The testimony of Sandys on this point is confirmed by that of Pighio,
Braccini, Magliocco, Salimbeni, and Nicola di Rubeo, 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 1631. 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 1139, ashes were thrown out for many days. I take those
dates from the work of Roth just cited.
[117] 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.
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.
The North American Indians did not inhabit the interior of the forests. Their
settlements 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 villages.
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
Page 406
account of that expedition in Harper's Magazine for March, April, and May,
1855.
Clavé, 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 food,
garments to cover his nakedness, arms for his defence."—Études sur l'Économie
Forestière, 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.
[118] The origin of the great natural meadows, or prairies as they are called,
of the valley of the Mississippi, is obscure. There is, of course, no historical
evidence on the subject, and I believe that remains of forest vegetation are
seldom or never found beneath the surface, even in the sloughs, where the
perpetual moisture would preserve such remains indefinitely. The want of trees
upon them has been ascribed to the occasional long-continued droughts of
summer, and the excessive humidity of the soil in winter; but it is, in very many
instances, certain that, by whatever means the growth of forests upon them was
first prevented or destroyed, the trees have been since kept out of them only by
the annual burning of the grass, by grazing animals, or by cultivation. The groves
and belts of trees which are found upon the prairies, though their seedlings are
occasionally killed by drought, or by excess of moisture, extend themselves
rapidly over them when the seeds and shoots are protected against fire, cattle,
and the plough. The prairies, though of vast extent, must be considered as a
local, and, so far as our present knowledge extends, abnormal exception to the
law which clothes all suitable surfaces with forest; for there are many parts of the
United States—Ohio, for example—where the physical conditions appear to be
nearly identical with those of the States lying farther west, but where there were
comparatively few natural meadows. 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 those 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 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
1855.
Clavé, 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 food,
garments to cover his nakedness, arms for his defence."—Études sur l'Économie
Forestière, 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.
[118] The origin of the great natural meadows, or prairies as they are called,
of the valley of the Mississippi, is obscure. There is, of course, no historical
evidence on the subject, and I believe that remains of forest vegetation are
seldom or never found beneath the surface, even in the sloughs, where the
perpetual moisture would preserve such remains indefinitely. The want of trees
upon them has been ascribed to the occasional long-continued droughts of
summer, and the excessive humidity of the soil in winter; but it is, in very many
instances, certain that, by whatever means the growth of forests upon them was
first prevented or destroyed, the trees have been since kept out of them only by
the annual burning of the grass, by grazing animals, or by cultivation. The groves
and belts of trees which are found upon the prairies, though their seedlings are
occasionally killed by drought, or by excess of moisture, extend themselves
rapidly over them when the seeds and shoots are protected against fire, cattle,
and the plough. The prairies, though of vast extent, must be considered as a
local, and, so far as our present knowledge extends, abnormal exception to the
law which clothes all suitable surfaces with forest; for there are many parts of the
United States—Ohio, for example—where the physical conditions appear to be
nearly identical with those of the States lying farther west, but where there were
comparatively few natural meadows. 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 those 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 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
Page 407
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 be
an effect of too extensive clearings, rather than a cause of the want of woods. See
Appendix, No. 22.
[119] 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.
[120] The practice of burning over woodland, at once to clear and manure the
ground, is called in Swedish 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 haystacks,
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 afterward produces
nothing but weeds and briers.—Læstadius, 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 Clavé says: "In the
department of Ardennes it (le sartage) is the basis of agriculture. The northern
part of the department, comprising the arrondissements of Rocroi and Mézières,
is covered by steep wooded mountains with an argillaceous, compact, moist and
cold soil; it is furrowed by three valleys, or rather three deep ravines, at the
bottom of which roll the waters of the Meuse, the Semoy, and the Sormonne, and
villages show themselves wherever the walls of the valleys retreat sufficiently
from the rivers to give room to establish them. Deprived of arable soil, since the
nature of the ground permits neither regular clearing nor cultivation, the peasant
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 be
an effect of too extensive clearings, rather than a cause of the want of woods. See
Appendix, No. 22.
[119] 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.
[120] The practice of burning over woodland, at once to clear and manure the
ground, is called in Swedish 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 haystacks,
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 afterward produces
nothing but weeds and briers.—Læstadius, 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 Clavé says: "In the
department of Ardennes it (le sartage) is the basis of agriculture. The northern
part of the department, comprising the arrondissements of Rocroi and Mézières,
is covered by steep wooded mountains with an argillaceous, compact, moist and
cold soil; it is furrowed by three valleys, or rather three deep ravines, at the
bottom of which roll the waters of the Meuse, the Semoy, and the Sormonne, and
villages show themselves wherever the walls of the valleys retreat sufficiently
from the rivers to give room to establish them. Deprived of arable soil, since the
nature of the ground permits neither regular clearing nor cultivation, the peasant
Page 408
of the Ardennes, by means of burning, obtains from the forest a subsistence
which, without this resource, would fail him. After the removal of the disposable
wood, he spreads over the soil the branches, twigs, briars, and heath, sets fire to
them in the dry weather of July and August, and sows in September a crop of
rye, which he covers by a light ploughing. Thus prepared, the ground yields from
seventeen to twenty bushels an acre, besides a ton and a half or two tons of straw
of the best quality for the manufacture of straw hats."—Clavé, Études sur
l'Économie Forestière, p. 21.
Clavé does not expressly condemn the sartage, which indeed seems the only
practicable method of obtaining crops from the soil he describes, but, as we shall
see hereafter, it is regarded by most writers as a highly pernicious practice.
[121] 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, 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 was 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 the wood found in bogs, is not unfrequently such as to suggest
the theory of a considerable change of climate during the human period. But the
laws which govern the germination and growth of forest trees must be further
studied, and the primitive local conditions of the sites where ancient woods lie
buried must be better ascertained, before this theory can be admitted upon the
evidence in question. In fact, the order of succession—for a rotation or
alternation is not yet proved—may 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. See Berg, Das Verdrängen
der Laubwälder im Nördlichen Deutschland, 1844. Heyer, Das Verhalten der
Waldbäume gegen Licht und Schatten, 1852. Staring, De Bodem van Nederland,
1856, i, pp. 120-200. Vaupell, Om Bögens Indvandring i de Danske Skove,
1857. Knorr, Studien über die Buchen-Wirthschaft, 1863.
which, without this resource, would fail him. After the removal of the disposable
wood, he spreads over the soil the branches, twigs, briars, and heath, sets fire to
them in the dry weather of July and August, and sows in September a crop of
rye, which he covers by a light ploughing. Thus prepared, the ground yields from
seventeen to twenty bushels an acre, besides a ton and a half or two tons of straw
of the best quality for the manufacture of straw hats."—Clavé, Études sur
l'Économie Forestière, p. 21.
Clavé does not expressly condemn the sartage, which indeed seems the only
practicable method of obtaining crops from the soil he describes, but, as we shall
see hereafter, it is regarded by most writers as a highly pernicious practice.
[121] 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, 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 was 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 the wood found in bogs, is not unfrequently such as to suggest
the theory of a considerable change of climate during the human period. But the
laws which govern the germination and growth of forest trees must be further
studied, and the primitive local conditions of the sites where ancient woods lie
buried must be better ascertained, before this theory can be admitted upon the
evidence in question. In fact, the order of succession—for a rotation or
alternation is not yet proved—may 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. See Berg, Das Verdrängen
der Laubwälder im Nördlichen Deutschland, 1844. Heyer, Das Verhalten der
Waldbäume gegen Licht und Schatten, 1852. Staring, De Bodem van Nederland,
1856, i, pp. 120-200. Vaupell, Om Bögens Indvandring i de Danske Skove,
1857. Knorr, Studien über die Buchen-Wirthschaft, 1863.
Page 409
[122] 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.
[123] The paragrandine, or, as it is called in French, the paragrêle, 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 for this purpose poles supporting sheaves of straw connected with the
ground by the same material; but the experiment was afterward 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.
[124] Cenni sulla Importanza e Coltura dei Boschi, p. 6.
[125] Memoria sui Boschi, etc., p. 44.
[126] Travels in Italy, chap. iii.
[127] Le Alpi che cingono l'Italia, i, p. 377.
[128] "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."—Clavé, Études sur
l'Économie Forestière, p. 13.
This opinion of the modification of the atmosphere by vegetation is
contested.
[129] 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
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.
[123] The paragrandine, or, as it is called in French, the paragrêle, 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 for this purpose poles supporting sheaves of straw connected with the
ground by the same material; but the experiment was afterward 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.
[124] Cenni sulla Importanza e Coltura dei Boschi, p. 6.
[125] Memoria sui Boschi, etc., p. 44.
[126] Travels in Italy, chap. iii.
[127] Le Alpi che cingono l'Italia, i, p. 377.
[128] "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."—Clavé, Études sur
l'Économie Forestière, p. 13.
This opinion of the modification of the atmosphere by vegetation is
contested.
[129] 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
Page 410
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 Appendix, No. 23.
[130] 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, silicious 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. If we
represent the power of calcareous sand to retain heat by 100, we have, according
to Schubler,
For [silicious?] sand 95.6
" arable calcareous soil 74.8
" argillaceous earth 68.4
" garden earth 64.8
" humus 49.0
"The retentive power of humus, then, is but half as great as that of calcareous
sand. We will add that the power of 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 silicious pebbles cools more slowly than silicious 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 boisés, p. 137.
[131] "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, as quoted
by Coultas, What may be learned from a Tree, p. 34.
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 Appendix, No. 23.
[130] 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, silicious 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. If we
represent the power of calcareous sand to retain heat by 100, we have, according
to Schubler,
For [silicious?] sand 95.6
" arable calcareous soil 74.8
" argillaceous earth 68.4
" garden earth 64.8
" humus 49.0
"The retentive power of humus, then, is but half as great as that of calcareous
sand. We will add that the power of 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 silicious pebbles cools more slowly than silicious 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 boisés, p. 137.
[131] "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, as quoted
by Coultas, What may be learned from a Tree, p. 34.
Page 411
[132] See, on this particular point, and on the general influence of the forest
on temperature, Humboldt, Ansichten der Natur, i, 158.
[133] 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.
[134] Becquerel, Des Climats, etc., Discours Prélim. vi.
[135] Travels, i, p. 61.
[136] Le Alpi che cingono l'Italia, pp. 370, 371.
[137] Bergsöe, Reventlovs Virksomhed, ii, p. 125.
[138] Becquerel, Des Climats, etc., p. 179.
[139] Ibid., p. 116.
[140] 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 Baude, entitled "Les Cotes de la 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
on temperature, Humboldt, Ansichten der Natur, i, 158.
[133] 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.
[134] Becquerel, Des Climats, etc., Discours Prélim. vi.
[135] Travels, i, p. 61.
[136] Le Alpi che cingono l'Italia, pp. 370, 371.
[137] Bergsöe, Reventlovs Virksomhed, ii, p. 125.
[138] Becquerel, Des Climats, etc., p. 179.
[139] Ibid., p. 116.
[140] 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 Baude, entitled "Les Cotes de la 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
Page 412
the plateau of La Hague have been transformed, under their protection, into
fertile fields."—Revue des Deux Mondes, January, 1859, p. 277.
[141] Cenni sulla Importanza e Coltura dei Boschi, p. 31.
[142] La Provence au point de vue des Torrents et des Inondations, p. 19.
[143] Ueber die Entwaldung der Gebirge, p. 28.
[144] Becquerel, Des Climats, etc., p. 9.
[145] Salvagnoli, Rapporto sul Bonificamento delle Maremme Toscane, pp.
xli, 124.
[146] Il Politecnico, Milano, Aprile e Maggio, 1863, p. 35.
[147] Salvagnoli, Memorie sulle Maremme Toscane, pp. 213, 214.
[148] Except in the seething marshes of the tropics, where vegetable decay is
extremely rapid, the uniformity of temperature and of atmospheric humidity
renders all forests eminently healthful. See Hohenstein's observations on this
subject, Der Wald, p. 41.
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.
[149] Memoria sui Boschi di Lombardia, p. 45.
[150] Économie Rurale, i, p. 22.
[151] Rossmässler, Der Wald, p. 158.
[152] Ibid., p. 160.
[153] 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 icehouses, by a covering of straw, which naturally
fertile fields."—Revue des Deux Mondes, January, 1859, p. 277.
[141] Cenni sulla Importanza e Coltura dei Boschi, p. 31.
[142] La Provence au point de vue des Torrents et des Inondations, p. 19.
[143] Ueber die Entwaldung der Gebirge, p. 28.
[144] Becquerel, Des Climats, etc., p. 9.
[145] Salvagnoli, Rapporto sul Bonificamento delle Maremme Toscane, pp.
xli, 124.
[146] Il Politecnico, Milano, Aprile e Maggio, 1863, p. 35.
[147] Salvagnoli, Memorie sulle Maremme Toscane, pp. 213, 214.
[148] Except in the seething marshes of the tropics, where vegetable decay is
extremely rapid, the uniformity of temperature and of atmospheric humidity
renders all forests eminently healthful. See Hohenstein's observations on this
subject, Der Wald, p. 41.
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.
[149] Memoria sui Boschi di Lombardia, p. 45.
[150] Économie Rurale, i, p. 22.
[151] Rossmässler, Der Wald, p. 158.
[152] Ibid., p. 160.
[153] 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 icehouses, by a covering of straw, which naturally
Page 413
sometimes contains kernels of grain. These often sprout, and even throw out
roots and leaves to a considerable length, in a temperature very 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 icehouse, 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. See App. 24.
[154] Becquerel, Des Climats, etc., pp. 139-141.
[155] Dr. Williams made some observations on this subject in 1789, and in
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 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 of Temperature of
Time. Difference.
ground in pasture. ground in 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 65½ 55½ 10
Aug. 15 68 58 10
" 31 59½ 55 4½
Sept. 15 59½ 55 4½
Oct. 1 59½ 55 4½
" 15 49 49 0
Nov. 1 43 43 0
" 16 43½ 43½ 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°. 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.—Williams's Vermont, i, p. 74.
Bodies of fresh water, so large as not to be sensibly affected by local
influences of narrow reach or short duration, would afford climatic indications
well worthy of special observation. Lake Champlain, which forms the boundary
roots and leaves to a considerable length, in a temperature very 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 icehouse, 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. See App. 24.
[154] Becquerel, Des Climats, etc., pp. 139-141.
[155] Dr. Williams made some observations on this subject in 1789, and in
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 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 of Temperature of
Time. Difference.
ground in pasture. ground in 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 65½ 55½ 10
Aug. 15 68 58 10
" 31 59½ 55 4½
Sept. 15 59½ 55 4½
Oct. 1 59½ 55 4½
" 15 49 49 0
Nov. 1 43 43 0
" 16 43½ 43½ 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°. 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.—Williams's Vermont, i, p. 74.
Bodies of fresh water, so large as not to be sensibly affected by local
influences of narrow reach or short duration, would afford climatic indications
well worthy of special observation. Lake Champlain, which forms the boundary
Page 414
between the States of New York and Vermont, presents very favorable conditions
for this purpose. This lake, which drains a basin of about 6,000 square miles,
covers an area, excluding its islands, of about 500 square miles. It extends from
lat. 43° 30' to 45° 20', in very nearly a meridian line, has a mean width of four
and a half miles, with an extreme breadth, excluding bays almost land-locked, of
thirteen miles. Its mean depth is not well known. It is, however, 400 feet deep in
some places, and from 100 to 200 in many, and has few shoals or flats. The
climate is of such severity that it rarely fails to freeze completely over, and to be
safely crossed upon the ice, with heavy teams, for several weeks every winter.
Thompson (Vermont, p. 14, and Appendix, p. 9) gives the following table of the
times of the complete closing and opening of the ice, opposite Burlington, about
the centre of the lake, and where it is ten miles wide.
Days Days
Year. Closing. Opening. Year. Closing. Opening.
closed. closed.
February January
1816 1836 April 21 85
9 27
January January
1817 April 16 78 1837 April 26 101
29 15
February February
1818 April 15 72 1838 April 13 70
2 2
January
1819 March 4 April 17 44 1839 April 6 71
25
1820 February February 1840
January February
26
{
3
March 8 March 12
}4 1841
25
February
20
April 19 61
18
January
1821 April 21 95 1842 not closed
15
January February
1822 March 30 75 1843 April 22 65
24 16
February January
1823 April 5 57 1844 April 11 77
7 25
January February February
1824 20 1845 March 26 51
22 11 3
February February
1825 1846 March 26 44
9 10
February February
1826 March 24 51 1847 April 23 68
1 15
January February February
1827 March 31 68 1848 13
21 13 26
February
1828 not closed 1849 March 23 44
7
January
1829 April 1850 not closed
31
February February
1832 April 17 70 1851 March 12 89
6 1
for this purpose. This lake, which drains a basin of about 6,000 square miles,
covers an area, excluding its islands, of about 500 square miles. It extends from
lat. 43° 30' to 45° 20', in very nearly a meridian line, has a mean width of four
and a half miles, with an extreme breadth, excluding bays almost land-locked, of
thirteen miles. Its mean depth is not well known. It is, however, 400 feet deep in
some places, and from 100 to 200 in many, and has few shoals or flats. The
climate is of such severity that it rarely fails to freeze completely over, and to be
safely crossed upon the ice, with heavy teams, for several weeks every winter.
Thompson (Vermont, p. 14, and Appendix, p. 9) gives the following table of the
times of the complete closing and opening of the ice, opposite Burlington, about
the centre of the lake, and where it is ten miles wide.
Days Days
Year. Closing. Opening. Year. Closing. Opening.
closed. closed.
February January
1816 1836 April 21 85
9 27
January January
1817 April 16 78 1837 April 26 101
29 15
February February
1818 April 15 72 1838 April 13 70
2 2
January
1819 March 4 April 17 44 1839 April 6 71
25
1820 February February 1840
January February
26
{
3
March 8 March 12
}4 1841
25
February
20
April 19 61
18
January
1821 April 21 95 1842 not closed
15
January February
1822 March 30 75 1843 April 22 65
24 16
February January
1823 April 5 57 1844 April 11 77
7 25
January February February
1824 20 1845 March 26 51
22 11 3
February February
1825 1846 March 26 44
9 10
February February
1826 March 24 51 1847 April 23 68
1 15
January February February
1827 March 31 68 1848 13
21 13 26
February
1828 not closed 1849 March 23 44
7
January
1829 April 1850 not closed
31
February February
1832 April 17 70 1851 March 12 89
6 1
Page 415
February January
1833 April 6 63 1852 April 10 92
2 18
February February
1834 7
13 20
1835 January January
18
10 23
{ February
7
April 12 64
In 1847, although, at the point indicated, the ice broke up on the 23d of April,
it remained frozen much later at the North, and steamers were not able to
traverse the whole length of the lake until May 6th.
[156] We are not, indeed, to suppose that condensation of vapor and
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 raindrops, and raindrops 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 raindrops, which, if not divided by some obstruction, will reach the ground,
though passing all the time through strata which would vaporize them if they
were in a state of more minute division.
[157] 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 toward or from itself.
These air streams have a certain, though doubtless a very small influence on the
force and direction of greater atmospheric movements.
[158] 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
1833 April 6 63 1852 April 10 92
2 18
February February
1834 7
13 20
1835 January January
18
10 23
{ February
7
April 12 64
In 1847, although, at the point indicated, the ice broke up on the 23d of April,
it remained frozen much later at the North, and steamers were not able to
traverse the whole length of the lake until May 6th.
[156] We are not, indeed, to suppose that condensation of vapor and
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 raindrops, and raindrops 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 raindrops, which, if not divided by some obstruction, will reach the ground,
though passing all the time through strata which would vaporize them if they
were in a state of more minute division.
[157] 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 toward or from itself.
These air streams have a certain, though doubtless a very small influence on the
force and direction of greater atmospheric movements.
[158] 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
Page 416
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 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 transmissibility 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
Ægean. 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 nest 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 northward, and between sunrise and twelve
o'clock 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 κυμάτων
ἀνήριθμον γέλασμα rarely silent, over so great a space as ninety or even seventy-
eight nautical miles. I apply the epithet silent to γέλασμα advisedly. I am
convinced that Æschylus 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.
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 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 transmissibility 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
Ægean. 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 nest 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 northward, and between sunrise and twelve
o'clock 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 κυμάτων
ἀνήριθμον γέλασμα rarely silent, over so great a space as ninety or even seventy-
eight nautical miles. I apply the epithet silent to γέλασμα advisedly. I am
convinced that Æschylus 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.
Page 417
[159] "The presence of watery vapor in the air is general. * * * Vegetable
surfaces are endowed with the power of absorbing gases, vapors, and also, no
doubt, the various soluble bodies which are presented to them. The inhalation of
humidity is carried on by the leaves upon a large scale; the dew of a cold
summer night revives the groves and the meadows, and a single shower of rain
suffices to refresh the verdure of a forest which a long drought had parched."—
Schacht, Les Arbres, ix, p. 340.
The absorption of the vapor of water by leaves is disputed. "The absorption
of watery vapor by the leaves of plants is, according to Unger's experiments,
inadmissible."—Wilhelm, Der Boden und das Wasser, p. 19. If this latter view is
correct, the apparently refreshing effects of atmospheric humidity upon
vegetation must be ascribed to moisture absorbed by the ground from the air and
supplied to the roots. In some recent experiments by Dr. Sachs, a porous flower-
pot, with a plant growing in it, was left unwatered until the earth was dry, and the
plant began to languish. The pot was then placed in a glass case containing air,
which was kept always saturated with humidity, but no water was supplied, and
the leaves of the plant were exposed to the open atmosphere. The soil in the
flower pot absorbed from the air moisture enough to revive the foliage, and keep
it a long time green, but not enough to promote development of new leaves.—
Id., ibid., p. 18.
[160] The experiments of Hales and others, on the absorption and exhalation
of water by vegetables, are of the highest 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.
[161] In the primitive forest, except where the soil is too wet for the dense
growth of trees, the ground is generally too thickly covered with leaves to allow
much room for ground mosses. In the more open woods of Europe, this form of
vegetation is more frequent—as, indeed, are many other small plants of a more
inviting character—than in the native American forest. See, on the cryptogams
and wood plants, Rossmässler, Der Wald, pp. 33 et seqq.
[162] Emerson (Trees of Massachusetts, p. 493) mentions a maple six feet in
diameter, as having yielded a barrel, or thirty-one and a 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. 91) says: "A man much
surfaces are endowed with the power of absorbing gases, vapors, and also, no
doubt, the various soluble bodies which are presented to them. The inhalation of
humidity is carried on by the leaves upon a large scale; the dew of a cold
summer night revives the groves and the meadows, and a single shower of rain
suffices to refresh the verdure of a forest which a long drought had parched."—
Schacht, Les Arbres, ix, p. 340.
The absorption of the vapor of water by leaves is disputed. "The absorption
of watery vapor by the leaves of plants is, according to Unger's experiments,
inadmissible."—Wilhelm, Der Boden und das Wasser, p. 19. If this latter view is
correct, the apparently refreshing effects of atmospheric humidity upon
vegetation must be ascribed to moisture absorbed by the ground from the air and
supplied to the roots. In some recent experiments by Dr. Sachs, a porous flower-
pot, with a plant growing in it, was left unwatered until the earth was dry, and the
plant began to languish. The pot was then placed in a glass case containing air,
which was kept always saturated with humidity, but no water was supplied, and
the leaves of the plant were exposed to the open atmosphere. The soil in the
flower pot absorbed from the air moisture enough to revive the foliage, and keep
it a long time green, but not enough to promote development of new leaves.—
Id., ibid., p. 18.
[160] The experiments of Hales and others, on the absorption and exhalation
of water by vegetables, are of the highest 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.
[161] In the primitive forest, except where the soil is too wet for the dense
growth of trees, the ground is generally too thickly covered with leaves to allow
much room for ground mosses. In the more open woods of Europe, this form of
vegetation is more frequent—as, indeed, are many other small plants of a more
inviting character—than in the native American forest. See, on the cryptogams
and wood plants, Rossmässler, Der Wald, pp. 33 et seqq.
[162] Emerson (Trees of Massachusetts, p. 493) mentions a maple six feet in
diameter, as having yielded a barrel, or thirty-one and a 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. 91) says: "A man much
Page 418
employed in making 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.
[163] "The buds of the maple," says the same correspondent, "do not start till
toward the close of the sugar season. As soon as they begin to swell, the sap
seems less sweet, and the sugar made from it is of a darker color, and with less of
the distinctive maple flavor."
[164] "In this region, maples are usually tapped with a three-quarter inch bit,
boring to the depth of one and a half or two inches. In the smaller trees, one
incision only is made, two in those of eighteen inches in diameter, and four in
trees of larger size. Two 3/4-inch holes in a tree twenty-two inches in diameter =
1/46 of the circumference, and 1/169 of the area of section."
"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 in burning. No difference
has been observed in the starting of the buds of tapped and untapped trees."—
Same correspondent.
[165] 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."
According to the census returns, the quantity of maple sugar made in the
United States in 1850 was 34,253,436 pounds; in 1860, it was 38,863,884
pounds, besides 1,944,594 gallons of molasses. The cane sugar made in 1850
amounted to 237,133,000 pounds; in 1859, to 302,205,000.—Preliminary Report
on the Eighth Census, p. 88.
According to Bigelow, Les États Unis d'Amérique en 1863, chap. iv, the
sugar product of Louisiana alone for 1862 is estimated at 528,321,500 pounds.
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.
[163] "The buds of the maple," says the same correspondent, "do not start till
toward the close of the sugar season. As soon as they begin to swell, the sap
seems less sweet, and the sugar made from it is of a darker color, and with less of
the distinctive maple flavor."
[164] "In this region, maples are usually tapped with a three-quarter inch bit,
boring to the depth of one and a half or two inches. In the smaller trees, one
incision only is made, two in those of eighteen inches in diameter, and four in
trees of larger size. Two 3/4-inch holes in a tree twenty-two inches in diameter =
1/46 of the circumference, and 1/169 of the area of section."
"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 in burning. No difference
has been observed in the starting of the buds of tapped and untapped trees."—
Same correspondent.
[165] 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."
According to the census returns, the quantity of maple sugar made in the
United States in 1850 was 34,253,436 pounds; in 1860, it was 38,863,884
pounds, besides 1,944,594 gallons of molasses. The cane sugar made in 1850
amounted to 237,133,000 pounds; in 1859, to 302,205,000.—Preliminary Report
on the Eighth Census, p. 88.
According to Bigelow, Les États Unis d'Amérique en 1863, chap. iv, the
sugar product of Louisiana alone for 1862 is estimated at 528,321,500 pounds.
Page 419
[166] 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 [1,890 gallons]."
[167] "The best state of weather for a good run," says my correspondent, "is
clear days, thawing fast in the daytime and freezing well at night, with a gentle
west or northwest wind; though we sometimes have clear, fine, thawing days
followed by frosty nights, without a good run of sap, I have thought it probable
that the irregular flow of sap on different days in the same season is connected
with the variation in atmospheric pressure; for the atmospheric conditions above
mentioned as those most favorable to a free flow of sap are also those in which
the barometer usually indicates pressure considerably above the mean. With a
south or southeast wind, and in lowering weather, which causes a fall in the
barometer, the flow generally ceases, though the sap sometimes runs till after the
beginning of the storm. With a gentle wind, south of west, maples sometimes run
all night. When this occurs, it is oftenest shortly before a storm. Last spring, the
sap of a sugar orchard in a neighboring town flowed the greater part of the time
for two days and two nights successively, and did not cease till after the
commencement of a rain storm."
The cessation of the flow of sap at night is perhaps in part to be ascribed to
the nocturnal frost, which checks the melting of the snow, of course diminishing
the supply of moisture in the ground, and sometimes congeals the strata from
which the rootlets suck in water. From the facts already mentioned, however, and
from other well-known circumstances—such, for example, as the more liberal
flow of sap from incisions on the south side of the trunk—it is evident that the
withdrawal of the stimulating influences of the sun's light and heat is the
principal cause of the suspension of the circulation in the night.
[168] "The flow ceases altogether soon after the buds begin to swell."—
Letter before quoted.
[169] We might obtain a contribution to an approximate estimate of the
quantity of moisture abstracted by forest vegetation from the earth and the air, by
ascertaining, as nearly as possible, the quantity of wood on a given area, the
proportion of assimilable matter contained in the fluids of the tree at different
seasons of the year, the ages of the trees respectively, and the quantity of leaf and
seed annually shed by them. The results would, indeed, be very vague, but they
might serve to check or confirm estimates arrived at by other processes. The
following facts are items too loose perhaps to be employed as elements in such a
computation.
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 [1,890 gallons]."
[167] "The best state of weather for a good run," says my correspondent, "is
clear days, thawing fast in the daytime and freezing well at night, with a gentle
west or northwest wind; though we sometimes have clear, fine, thawing days
followed by frosty nights, without a good run of sap, I have thought it probable
that the irregular flow of sap on different days in the same season is connected
with the variation in atmospheric pressure; for the atmospheric conditions above
mentioned as those most favorable to a free flow of sap are also those in which
the barometer usually indicates pressure considerably above the mean. With a
south or southeast wind, and in lowering weather, which causes a fall in the
barometer, the flow generally ceases, though the sap sometimes runs till after the
beginning of the storm. With a gentle wind, south of west, maples sometimes run
all night. When this occurs, it is oftenest shortly before a storm. Last spring, the
sap of a sugar orchard in a neighboring town flowed the greater part of the time
for two days and two nights successively, and did not cease till after the
commencement of a rain storm."
The cessation of the flow of sap at night is perhaps in part to be ascribed to
the nocturnal frost, which checks the melting of the snow, of course diminishing
the supply of moisture in the ground, and sometimes congeals the strata from
which the rootlets suck in water. From the facts already mentioned, however, and
from other well-known circumstances—such, for example, as the more liberal
flow of sap from incisions on the south side of the trunk—it is evident that the
withdrawal of the stimulating influences of the sun's light and heat is the
principal cause of the suspension of the circulation in the night.
[168] "The flow ceases altogether soon after the buds begin to swell."—
Letter before quoted.
[169] We might obtain a contribution to an approximate estimate of the
quantity of moisture abstracted by forest vegetation from the earth and the air, by
ascertaining, as nearly as possible, the quantity of wood on a given area, the
proportion of assimilable matter contained in the fluids of the tree at different
seasons of the year, the ages of the trees respectively, and the quantity of leaf and
seed annually shed by them. The results would, indeed, be very vague, but they
might serve to check or confirm estimates arrived at by other processes. The
following facts are items too loose perhaps to be employed as elements in such a
computation.
Page 420
Dr. Williams, who wrote when the woods of Northern New England were
generally in their primitive condition, states the number of trees growing on an
acre at from one hundred and fifty to six hundred and fifty, according to their
size and the quality of the soil; the quantity of wood, at from fifty to two hundred
cords, or from 238 to 952 cubic yards, but adds that on land covered with pines,
the quantity of wood would be much greater. Whether he means to give the
entire solid contents of the tree, or, as is usual in ordinary estimates in New
England, the marketable wood only, the trunks and larger branches, does not
appear. Next to the pine, the maple would probably yield a larger amount to a
given area than any of the other trees mentioned by Dr. Williams, but mixed
wood, in general, measures most. In a good deal of observation on this subject,
the largest quantity of marketable wood I have ever known cut on an acre of
virgin forest was one hundred and four cords, or 493 cubic yards, and half that
amount is considered a very fair yield. The smaller trees, branches, and twigs
would not increase the quantity more than twenty-five per cent., and if we add as
much more for the roots, we should have a total of about 750 cubic yards. I think
Dr. Williams's estimate too large, though it would fall much below the product of
the great trees of the Mississippi Valley, of Oregon, and of California. It should
be observed that these measurements are those of the wood as it lies when
'corded' or piled up for market, and exceed the real solid contents by not less
than fifteen per cent.
"In a soil of medium quality," says Clavé, quoting the estimates of Pfeil, for
the climate of Prussia, "the volume of a hectare of pines twenty years old, would
exceed 80 cubic mètres [42½ cubic yards to the acre]; it would amount to but 24
in a meagre soil. This tree attains its maximum of mean growth at the age of
seventy-five years. At that age, in the sandy earth of Prussia, it produces annually
about 5 cubic mètres, with a total volume of 311 cubic mètres per hectare [166
cubic yards per acre]. After this age the volume increases, but the mean rate of
growth diminishes. At eighty years, for instance, the volume is 335 cubic mètres,
the annual production 4 only. The beech reaches its maximum of annual growth
at one hundred and twenty years. It then has a total volume of 633 cubic mètres
to the hectare [335 cubic yards to the acre], and produces 5 cubic mètres per
year."—Clavé, Études, p. 151.
These measures, I believe, include the entire ligneous product of the tree,
exclusive of the roots, and express the actual solid contents. The specific gravity
of maple wood is stated to be 75. Maple sap yields sugar at the rate of about one
pound wet sugar to three gallons of sap, and wet sugar is to dry sugar in about
the proportion of nineteen to sixteen. Besides the sugar, there is a small residuum
of "sand," composed of phosphate of lime, with a little silex, and it is certain that
by the ordinary hasty process of manufacture, a good deal of sugar is lost; for the
drops, condensed from the vapor of the boilers on the rafters of the rude sheds
where the sap is boiled, have a decidedly sweet taste.
generally in their primitive condition, states the number of trees growing on an
acre at from one hundred and fifty to six hundred and fifty, according to their
size and the quality of the soil; the quantity of wood, at from fifty to two hundred
cords, or from 238 to 952 cubic yards, but adds that on land covered with pines,
the quantity of wood would be much greater. Whether he means to give the
entire solid contents of the tree, or, as is usual in ordinary estimates in New
England, the marketable wood only, the trunks and larger branches, does not
appear. Next to the pine, the maple would probably yield a larger amount to a
given area than any of the other trees mentioned by Dr. Williams, but mixed
wood, in general, measures most. In a good deal of observation on this subject,
the largest quantity of marketable wood I have ever known cut on an acre of
virgin forest was one hundred and four cords, or 493 cubic yards, and half that
amount is considered a very fair yield. The smaller trees, branches, and twigs
would not increase the quantity more than twenty-five per cent., and if we add as
much more for the roots, we should have a total of about 750 cubic yards. I think
Dr. Williams's estimate too large, though it would fall much below the product of
the great trees of the Mississippi Valley, of Oregon, and of California. It should
be observed that these measurements are those of the wood as it lies when
'corded' or piled up for market, and exceed the real solid contents by not less
than fifteen per cent.
"In a soil of medium quality," says Clavé, quoting the estimates of Pfeil, for
the climate of Prussia, "the volume of a hectare of pines twenty years old, would
exceed 80 cubic mètres [42½ cubic yards to the acre]; it would amount to but 24
in a meagre soil. This tree attains its maximum of mean growth at the age of
seventy-five years. At that age, in the sandy earth of Prussia, it produces annually
about 5 cubic mètres, with a total volume of 311 cubic mètres per hectare [166
cubic yards per acre]. After this age the volume increases, but the mean rate of
growth diminishes. At eighty years, for instance, the volume is 335 cubic mètres,
the annual production 4 only. The beech reaches its maximum of annual growth
at one hundred and twenty years. It then has a total volume of 633 cubic mètres
to the hectare [335 cubic yards to the acre], and produces 5 cubic mètres per
year."—Clavé, Études, p. 151.
These measures, I believe, include the entire ligneous product of the tree,
exclusive of the roots, and express the actual solid contents. The specific gravity
of maple wood is stated to be 75. Maple sap yields sugar at the rate of about one
pound wet sugar to three gallons of sap, and wet sugar is to dry sugar in about
the proportion of nineteen to sixteen. Besides the sugar, there is a small residuum
of "sand," composed of phosphate of lime, with a little silex, and it is certain that
by the ordinary hasty process of manufacture, a good deal of sugar is lost; for the
drops, condensed from the vapor of the boilers on the rafters of the rude sheds
where the sap is boiled, have a decidedly sweet taste.
Page 421
[170] "The elaborated sap, passing out of the leaves, is received into the
inner bark, * * * and a part of what descends finds 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, § 273.
[171] 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 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.
[172] Wilhelm, Der Boden und das Wasser, p. 18. It is not ascertained in
what proportions the dew is evaporated, and in what it is absorbed by the earth,
in actual nature, but there can be no doubt that the amount of water taken up by
the ground, both from vapor suspended in the air and from dew, is large. The
annual fall of dew in England is estimated at five inches, but this quantity is
much exceeded in many countries with a clearer sky. "In many of our Algerian
campaigns," says Babinet, "when it was wished to punish the brigandage of the
unsubdued tribes, it was impossible to set their grain fields on fire until a late
hour of the day; for the plants were so wet with the night dew that it was
necessary to wait until the sun had dried them."—Études et Lectures, ii, p. 212.
[173] "It has been concluded that the dry land occupies about 49,800,000
square statute miles. This does not include the recently discovered tracts of land
in the vicinity of the poles, and allowing for yet undiscovered land (which,
however, can only exist in small quantity), if we assign 51,000,000 to the land,
there will remain about 146,000,000 of square miles for the extent of surface
inner bark, * * * and a part of what descends finds 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, § 273.
[171] 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 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.
[172] Wilhelm, Der Boden und das Wasser, p. 18. It is not ascertained in
what proportions the dew is evaporated, and in what it is absorbed by the earth,
in actual nature, but there can be no doubt that the amount of water taken up by
the ground, both from vapor suspended in the air and from dew, is large. The
annual fall of dew in England is estimated at five inches, but this quantity is
much exceeded in many countries with a clearer sky. "In many of our Algerian
campaigns," says Babinet, "when it was wished to punish the brigandage of the
unsubdued tribes, it was impossible to set their grain fields on fire until a late
hour of the day; for the plants were so wet with the night dew that it was
necessary to wait until the sun had dried them."—Études et Lectures, ii, p. 212.
[173] "It has been concluded that the dry land occupies about 49,800,000
square statute miles. This does not include the recently discovered tracts of land
in the vicinity of the poles, and allowing for yet undiscovered land (which,
however, can only exist in small quantity), if we assign 51,000,000 to the land,
there will remain about 146,000,000 of square miles for the extent of surface
Page 422
occupied by the ocean."—Sir J. F. W. Herschel, Physical Geography, 1861, p.
19.
It does not appear to which category Herschel assigns the inland seas and the
fresh-water lakes and rivers of the earth; and Mrs. Somerville, who states that the
"dry land occupies an area of 38,000,000 of square miles," and that "the ocean
covers nearly three fourths of the surface of the globe," is equally silent on this
point.—Physical Geography, fifth edition, p. 30. On the following page, Mrs.
Somerville, in a note, cites Mr. Gardner as her authority, and says that,
"according to his computation, the extent of land is about 37,673,000 square
British miles, independently of Victoria Continent; and the sea occupies
110,849,000. Hence the land is to the sea as 1 to 4 nearly." Sir John F. W.
Herschel makes the area of dry land and ocean together 197,000,000 square
miles; Mrs. Somerville, or rather Mr. Gardner, 148,522,000. I suppose Sir John
Herschel includes the islands in his aggregate of the "dry land," and the inland
waters under the general designation of the "ocean," and that Mrs. Somerville
excludes both.
[174] It has been observed in Sweden that the spring, in many districts where
the forests have been cleared off, now comes on a fortnight later than in the last
century.—Asbjörnsen, Om Skovene i Norge, p. 101.
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 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.
[175] 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.
[176]
——Det golde Strög i Afrika,
Der Intet voxe kan, da ei det regner,
Og, omvendt, ingen Regn kan falde, da
Der Intet voxer.
19.
It does not appear to which category Herschel assigns the inland seas and the
fresh-water lakes and rivers of the earth; and Mrs. Somerville, who states that the
"dry land occupies an area of 38,000,000 of square miles," and that "the ocean
covers nearly three fourths of the surface of the globe," is equally silent on this
point.—Physical Geography, fifth edition, p. 30. On the following page, Mrs.
Somerville, in a note, cites Mr. Gardner as her authority, and says that,
"according to his computation, the extent of land is about 37,673,000 square
British miles, independently of Victoria Continent; and the sea occupies
110,849,000. Hence the land is to the sea as 1 to 4 nearly." Sir John F. W.
Herschel makes the area of dry land and ocean together 197,000,000 square
miles; Mrs. Somerville, or rather Mr. Gardner, 148,522,000. I suppose Sir John
Herschel includes the islands in his aggregate of the "dry land," and the inland
waters under the general designation of the "ocean," and that Mrs. Somerville
excludes both.
[174] It has been observed in Sweden that the spring, in many districts where
the forests have been cleared off, now comes on a fortnight later than in the last
century.—Asbjörnsen, Om Skovene i Norge, p. 101.
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 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.
[175] 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.
[176]
——Det golde Strög i Afrika,
Der Intet voxe kan, da ei det regner,
Og, omvendt, ingen Regn kan falde, da
Der Intet voxer.
Page 423
Paludan-Müller,
Adam Homo, ii, 408.
[177]
Und Stürme brausen um die Wette
Vom Meer aufs Land, vom Land aufs Meer.
Goethe, Faust, Song of
the Archangels.
[178] Études sur l'Économie Forestière, pp. 45, 46.
[179] I am not aware of any evidence to show that Malta had any woods of
importance at any time since the cultivation of cotton was introduced there; and
if it is true, as has been often asserted, that its present soil was imported from
Sicily, it can certainly have possessed no forests since a very remote period. In
Sandys's time, 1611, there were no woods in the island, and it produced little
cotton. He describes it as "a country altogether champion, being no other than a
rocke couered ouer with earth, but two feete deepe where the deepest; hauing but
few trees but such as beare fruite. * * * So that their wood they haue from
Sicilia." They have "an indifferent quantity of cotton wooll, but that the best of
all other."—Sandys, Travels, p. 228.
[180] Schacht, Les Arbres, p. 412.
[181] What may be learned from a Tree, p. 117.
[182] Der Wald, p. 13.
[183] Om Skovene og deres Forhold til Nationalœconomien, pp. 131-133.
[184] Om Skovene og om et ordnet Skovbrug i Norge, p. 106.
[185] Études et Lectures, iv. p. 114.
[186] The supposed increase in the frequency and quantity of rain in Lower
Egypt is by no means established. I have heard it disputed on the spot by
intelligent Franks, whose residence in that country began before the plantations
of Mehemet Aali and Ibrahim Pacha, and I have been assured by them that
meteorological observations, made at Alexandria about the beginning 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
Adam Homo, ii, 408.
[177]
Und Stürme brausen um die Wette
Vom Meer aufs Land, vom Land aufs Meer.
Goethe, Faust, Song of
the Archangels.
[178] Études sur l'Économie Forestière, pp. 45, 46.
[179] I am not aware of any evidence to show that Malta had any woods of
importance at any time since the cultivation of cotton was introduced there; and
if it is true, as has been often asserted, that its present soil was imported from
Sicily, it can certainly have possessed no forests since a very remote period. In
Sandys's time, 1611, there were no woods in the island, and it produced little
cotton. He describes it as "a country altogether champion, being no other than a
rocke couered ouer with earth, but two feete deepe where the deepest; hauing but
few trees but such as beare fruite. * * * So that their wood they haue from
Sicilia." They have "an indifferent quantity of cotton wooll, but that the best of
all other."—Sandys, Travels, p. 228.
[180] Schacht, Les Arbres, p. 412.
[181] What may be learned from a Tree, p. 117.
[182] Der Wald, p. 13.
[183] Om Skovene og deres Forhold til Nationalœconomien, pp. 131-133.
[184] Om Skovene og om et ordnet Skovbrug i Norge, p. 106.
[185] Études et Lectures, iv. p. 114.
[186] The supposed increase in the frequency and quantity of rain in Lower
Egypt is by no means established. I have heard it disputed on the spot by
intelligent Franks, whose residence in that country began before the plantations
of Mehemet Aali and Ibrahim Pacha, and I have been assured by them that
meteorological observations, made at Alexandria about the beginning 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
Page 424
Egypt, I inquired of the local governor in relation to the frequency of this
phenomenon, and was told by him that not a 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 Jomard and others, and
are probably erroneous. See, Foissac, Météorologie, 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 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, §§ 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."
[187] Étude sur les Eaux au point de vue des Inondations, p. 91.
[188] Économie Rurale, ii, chap. xx, § 4, pp. 756-759. See also p. 733.
[189] Jacini, speaking of the great Italian lakes, 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 Proprietà Fondiaria, etc., p. 144.
[190] Météorologie, German translation by Emsmann, p. 605.
phenomenon, and was told by him that not a 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 Jomard and others, and
are probably erroneous. See, Foissac, Météorologie, 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 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, §§ 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."
[187] Étude sur les Eaux au point de vue des Inondations, p. 91.
[188] Économie Rurale, ii, chap. xx, § 4, pp. 756-759. See also p. 733.
[189] Jacini, speaking of the great Italian lakes, 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 Proprietà Fondiaria, etc., p. 144.
[190] Météorologie, German translation by Emsmann, p. 605.
Page 425
[191] Handbuch der Physischen Geographie, p. 658.
[192] Annales des Ponts et Chaussées, 1854, 1st sémestre, pp. 21 et seqq.
See the comments of Vallès on these observations, in his Études sur les
Inondations, pp. 441 et seqq.
[193] The passage in Pliny is as follows: "Nascuntur fontes, decisis
plerumque silvis, quos arborum alimenta consumebant, sicut in Hæmo, obsidente
Gallos Cassandro, quum valli gratia cecidissent. Plerumque vero damnosi
torrentes corrivantur, detracta collibus silva continere nimbos ac digerere
consueta."—Nat. Hist., xxxi, 30.
Seneca cites this case, and another similar one said to have been observed at
Magnesia, from a passage in Theophrastus, not to be found in the extant works
of that author; but he adds that the stories are incredible, because shaded grounds
abound most in water: ferè aquosissima sunt quæcumque umbrosissima.—
Quæst. Nat., iii, 11. See Appendix, No. 26.
[194] "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 along 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."—Clavé, Études,
etc., pp. 53, 54.
[195] Vallès, Études sur les Inondations, p. 472.
[196] Économie Rurale, p. 730.
[197] Ueber die Entwaldung der Gebirge, pp. 20 et seqq.
[198] Physische Geographie, p. 32.
[199] The Trees of America, pp. 50, 51.
[200] Thompson's Vermont, appendix, p. 8.
[192] Annales des Ponts et Chaussées, 1854, 1st sémestre, pp. 21 et seqq.
See the comments of Vallès on these observations, in his Études sur les
Inondations, pp. 441 et seqq.
[193] The passage in Pliny is as follows: "Nascuntur fontes, decisis
plerumque silvis, quos arborum alimenta consumebant, sicut in Hæmo, obsidente
Gallos Cassandro, quum valli gratia cecidissent. Plerumque vero damnosi
torrentes corrivantur, detracta collibus silva continere nimbos ac digerere
consueta."—Nat. Hist., xxxi, 30.
Seneca cites this case, and another similar one said to have been observed at
Magnesia, from a passage in Theophrastus, not to be found in the extant works
of that author; but he adds that the stories are incredible, because shaded grounds
abound most in water: ferè aquosissima sunt quæcumque umbrosissima.—
Quæst. Nat., iii, 11. See Appendix, No. 26.
[194] "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 along 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."—Clavé, Études,
etc., pp. 53, 54.
[195] Vallès, Études sur les Inondations, p. 472.
[196] Économie Rurale, p. 730.
[197] Ueber die Entwaldung der Gebirge, pp. 20 et seqq.
[198] Physische Geographie, p. 32.
[199] The Trees of America, pp. 50, 51.
[200] Thompson's Vermont, appendix, p. 8.
Page 426
[201] Trees of America, p. 48.
[202] Dumont, following Dansse, 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 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 caram Lutetiam, [sic] enim Galli Parisiorum oppidum appellant,
quæ insula est non magna, in fluvio sita, qui eam omni ex parte eingit. Pontes
sublicii utrinque ad eam ferunt, raròque fluvius minuitur ae crescit; sed qualis
æstate, 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.
[203] 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.
[204] Stanley, citing Selden, De Jure Naturali, book vi, and Fabricius, Cod.
Pseudap. V. T., i, 874, mentions a remarkable Jewish tradition of uncertain but
unquestionably ancient date, which is among the oldest evidences of public
respect for the woods, and of enlightened views of their importance and proper
treatment:
"To Joshua a fixed Jewish tradition ascribed ten decrees, laying down precise
rules, which were instituted to protect the property of each tribe and of each
householder from lawless depredation. Cattle, of a smaller kind, were to be
allowed to graze in thick woods, not in thin woods; in woods, no kind of cattle
without the owner's consent. Sticks and branches might be gathered by any
Hebrew, but not cut. * * * Woods might be pruned, provided they were not olives
or fruit trees, and that there was sufficient shade in the place."—Lectures on the
History of the Jewish Church, part i, p. 271.
[205] There seems to have been a tendency to excessive clearing in Central
and Western, earlier than in Southeastern France. Wise and good Bernard Palissy
—one of those persecuted Protestants of the sixteenth century, whose heroism,
virtue, refinement, and taste shine out in such splendid contrast to the brutality,
corruption, grossness, and barbarism of their oppressors—in the Recepte
Véritable, 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
[202] Dumont, following Dansse, 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 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 caram Lutetiam, [sic] enim Galli Parisiorum oppidum appellant,
quæ insula est non magna, in fluvio sita, qui eam omni ex parte eingit. Pontes
sublicii utrinque ad eam ferunt, raròque fluvius minuitur ae crescit; sed qualis
æstate, 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.
[203] 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.
[204] Stanley, citing Selden, De Jure Naturali, book vi, and Fabricius, Cod.
Pseudap. V. T., i, 874, mentions a remarkable Jewish tradition of uncertain but
unquestionably ancient date, which is among the oldest evidences of public
respect for the woods, and of enlightened views of their importance and proper
treatment:
"To Joshua a fixed Jewish tradition ascribed ten decrees, laying down precise
rules, which were instituted to protect the property of each tribe and of each
householder from lawless depredation. Cattle, of a smaller kind, were to be
allowed to graze in thick woods, not in thin woods; in woods, no kind of cattle
without the owner's consent. Sticks and branches might be gathered by any
Hebrew, but not cut. * * * Woods might be pruned, provided they were not olives
or fruit trees, and that there was sufficient shade in the place."—Lectures on the
History of the Jewish Church, part i, p. 271.
[205] There seems to have been a tendency to excessive clearing in Central
and Western, earlier than in Southeastern France. Wise and good Bernard Palissy
—one of those persecuted Protestants of the sixteenth century, whose heroism,
virtue, refinement, and taste shine out in such splendid contrast to the brutality,
corruption, grossness, and barbarism of their oppressors—in the Recepte
Véritable, 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
Page 427
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."—Œuvres
Complètes de Bernard Palissy, 1844, p. 88.
[206] The great naval and commercial marines of Venice and of Genoa must
have occasioned an immense 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 the present day in the Mediterranean, and
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. 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 its woods 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. See Appendix, No. 27.
[207] Le Alpi che cingono l'Italia, i, p. 367.
[208] See the periodical Politecnico, published at Milan, for the month of
May, 1862, p. 234.
[209] Annali di Agricoltura, Industria e Commercio, vol. i, p. 77.
[210] 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 sea coal
was largely exported to the Continent, it had not yet come into general use in
England. It is a question of much interest, when 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 græfa 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 twelfth century, and in that passage it may as probably mean peat
as coal, and quite as probably something else as either. Coal is not mentioned in
King Alfred's Bede, in Glanville, or in Robert of Gloucester, though all these
writers speak of jet as found in England, and are full in their enumeration of the
mineral products of the island.
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."—Œuvres
Complètes de Bernard Palissy, 1844, p. 88.
[206] The great naval and commercial marines of Venice and of Genoa must
have occasioned an immense 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 the present day in the Mediterranean, and
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. 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 its woods 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. See Appendix, No. 27.
[207] Le Alpi che cingono l'Italia, i, p. 367.
[208] See the periodical Politecnico, published at Milan, for the month of
May, 1862, p. 234.
[209] Annali di Agricoltura, Industria e Commercio, vol. i, p. 77.
[210] 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 sea coal
was largely exported to the Continent, it had not yet come into general use in
England. It is a question of much interest, when 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 græfa 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 twelfth century, and in that passage it may as probably mean peat
as coal, and quite as probably something else as either. Coal is not mentioned in
King Alfred's Bede, in Glanville, or in Robert of Gloucester, though all these
writers speak of jet as found in England, and are full in their enumeration of the
mineral products of the island.
Page 428
England was anciently remarkable for its forests, but Cæsar 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 Cæsar intended by abies. The popular 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.—Rossmässler, Der Wald, pp. 256, 289, 324. If it were certain that the
abies of Cæsar 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; for our wainescot is not made in England. Yet
diuerse haue assaied to deale without [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
remoued 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 three
centuries before the time of Harrison. On page 204 of the Liber Albus—a book
which could have been far more valuable if the editor had given us the texts,
with his learned notes, instead of a translation—mention is made of "squared oak
timber," brought in from the country by 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 cartload. But in the chapter on the "Customs of
Billyngesgate," pp. 208, 209, relating to goods imported from foreign countries,
a duty of one halfpenny is imposed on every hundred of boards called
"weynscotte," 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.
[211] In a letter addressed to the Minister of Public Works, after the terrible
inundations of 1857, the Emperor 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
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 Cæsar intended by abies. The popular 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.—Rossmässler, Der Wald, pp. 256, 289, 324. If it were certain that the
abies of Cæsar 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; for our wainescot is not made in England. Yet
diuerse haue assaied to deale without [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
remoued 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 three
centuries before the time of Harrison. On page 204 of the Liber Albus—a book
which could have been far more valuable if the editor had given us the texts,
with his learned notes, instead of a translation—mention is made of "squared oak
timber," brought in from the country by 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 cartload. But in the chapter on the "Customs of
Billyngesgate," pp. 208, 209, relating to goods imported from foreign countries,
a duty of one halfpenny is imposed on every hundred of boards called
"weynscotte," 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.
[211] In a letter addressed to the Minister of Public Works, after the terrible
inundations of 1857, the Emperor 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
Page 429
which falls on the plains. The waters which fall on our fields produce but few
rivulets, but those 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'Héricourt, "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 Forestières, Déc., 1857, p. 311.
[212] "The roots of vegetables," says D'Héricourt, "perform the office of a
perpendicular drainage analogous to that which has been practised with success
in Holland and in some parts of the British Islands. This system consists in
driving down three or four thousand stakes upon a hectare; the rain water filters
down along the stakes, and, in certain cases, as favorable results are obtained by
this method as by horizontal drains."—Annales Forestières, 1857, p. 312.
[213] 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 an 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 covered
with slime by warping, as it is called, or admitting water over them at high tide,
are remarkably productive. See Appendix, No. 28.
[214] "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, have served
only to show the impotence of legislative notion on this subject."—Clavé,
Études sur l'Économie Forestière, 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 destroy a forest in spite of all
regulations to the contrary."—Dunoyer, De la Liberté du Travail, ii, p. 452, as
quoted by Clavé, p. 353.
rivulets, but those 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'Héricourt, "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 Forestières, Déc., 1857, p. 311.
[212] "The roots of vegetables," says D'Héricourt, "perform the office of a
perpendicular drainage analogous to that which has been practised with success
in Holland and in some parts of the British Islands. This system consists in
driving down three or four thousand stakes upon a hectare; the rain water filters
down along the stakes, and, in certain cases, as favorable results are obtained by
this method as by horizontal drains."—Annales Forestières, 1857, p. 312.
[213] 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 an 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 covered
with slime by warping, as it is called, or admitting water over them at high tide,
are remarkably productive. See Appendix, No. 28.
[214] "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, have served
only to show the impotence of legislative notion on this subject."—Clavé,
Études sur l'Économie Forestière, 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 destroy a forest in spite of all
regulations to the contrary."—Dunoyer, De la Liberté du Travail, ii, p. 452, as
quoted by Clavé, p. 353.
Page 430
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 save 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.
[215] See the lively account of the sale of a communal wood in Berlepsch,
Die Alpen, Holzschläger und Flösser.
[216] Streffleur (Ueber die Natur und die Wirkungen der Wildbäche, 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 Hagen's Beschreibung
neuerer Wasserbauwerke, Königsberg, 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.
[217] 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 "Théorique," 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 few hours by great storms,
when thou shalt have made ready thy parterre to receive the water, thou must lay
great stones 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."—Œuvres Complètes, p. 173.
[218] Ladoucette says the peasant of Dévoluy "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.
[219] The valley of Embrun, now almost completely devastated, was once
remarkable for its fertility. In 1806, Héricart de Thury said of it: "In this
magnificent valley nature had been prodigal of her gifts. Its inhabitants have
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 save 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.
[215] See the lively account of the sale of a communal wood in Berlepsch,
Die Alpen, Holzschläger und Flösser.
[216] Streffleur (Ueber die Natur und die Wirkungen der Wildbäche, 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 Hagen's Beschreibung
neuerer Wasserbauwerke, Königsberg, 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.
[217] 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 "Théorique," 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 few hours by great storms,
when thou shalt have made ready thy parterre to receive the water, thou must lay
great stones 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."—Œuvres Complètes, p. 173.
[218] Ladoucette says the peasant of Dévoluy "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.
[219] The valley of Embrun, now almost completely devastated, was once
remarkable for its fertility. In 1806, Héricart de Thury said of it: "In this
magnificent valley nature had been prodigal of her gifts. Its inhabitants have
Page 431
blindly revelled in her favors, and fallen asleep in the midst of her profusion."—
Becquerel, Des Climats, etc., p. 314.
[220] In the days of the Roman empire the Durance was a navigable 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.
[221] 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 99,000
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.—Clavé, Études, pp. 66, 67.
[222] The Skalära-Tobel, for instance, near Coire. See the description in
Berlepsch, Die Alpen, pp. 169 et seqq, or in Stephen's English translation.
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 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 twenty years, the superior quality of the arms manufactured at Brescia has
greatly enlarged the sale of them, and very naturally stimulated 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
Becquerel, Des Climats, etc., p. 314.
[220] In the days of the Roman empire the Durance was a navigable 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.
[221] 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 99,000
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.—Clavé, Études, pp. 66, 67.
[222] The Skalära-Tobel, for instance, near Coire. See the description in
Berlepsch, Die Alpen, pp. 169 et seqq, or in Stephen's English translation.
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 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 twenty years, the superior quality of the arms manufactured at Brescia has
greatly enlarged the sale of them, and very naturally stimulated 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
Page 432
most beautiful valleys of the Italian Alps into a ravine almost as 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 remarkable 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
transfertur de loco suo; lapides excavant aquæ et alluvione paullatim terra
consumitur."—Job xiv, 18, 19.
The English version is much less striking, and gives a different sense.
[223] Streffleur quotes from Duile the following observations: "The channel
of the Tyrolese brooks is often raised much above the valleys through which they
flow. The bed of the Fersina is elevated high above the city of Trient, 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 Schluderns menaces the far lower village with destruction, and the
chief town, Schwaz, is in similar danger from the Lahnbach."—Streffleur,
Ueber die Wildbäche, etc., p. 7.
[224] The snow drifts into the ravines and accumulates to incredible depths,
and the water resulting from its dissolution and from the deluging rains which
fall in spring, and sometimes in the summer, being confined by rocky walls on
both sides, rises to a very great height, and of course acquires an immense
velocity and transporting power in its rapid descent to its outlet from the
mountain. In the winter of 1842—'3, the valley of the Doveria, along which the
Simplon road passes, was filled with solid snowdrifts to the depth of a hundred
feet above the carriage road, and the sledge track by which passengers and the
mails were carried ran at that height.
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. As the current pours out of the gorge and escapes from the lateral
confinement of its walls, it spreads and divides itself into numerous smaller
streams, which shoot out from the mouth of the valley, 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. The stream retaining most nearly the original
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 remarkable 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
transfertur de loco suo; lapides excavant aquæ et alluvione paullatim terra
consumitur."—Job xiv, 18, 19.
The English version is much less striking, and gives a different sense.
[223] Streffleur quotes from Duile the following observations: "The channel
of the Tyrolese brooks is often raised much above the valleys through which they
flow. The bed of the Fersina is elevated high above the city of Trient, 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 Schluderns menaces the far lower village with destruction, and the
chief town, Schwaz, is in similar danger from the Lahnbach."—Streffleur,
Ueber die Wildbäche, etc., p. 7.
[224] The snow drifts into the ravines and accumulates to incredible depths,
and the water resulting from its dissolution and from the deluging rains which
fall in spring, and sometimes in the summer, being confined by rocky walls on
both sides, rises to a very great height, and of course acquires an immense
velocity and transporting power in its rapid descent to its outlet from the
mountain. In the winter of 1842—'3, the valley of the Doveria, along which the
Simplon road passes, was filled with solid snowdrifts to the depth of a hundred
feet above the carriage road, and the sledge track by which passengers and the
mails were carried ran at that height.
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. As the current pours out of the gorge and escapes from the lateral
confinement of its walls, it spreads and divides itself into numerous smaller
streams, which shoot out from the mouth of the valley, 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. The stream retaining most nearly the original
Page 433
direction moves with the greatest momentum, and consequently transports the
solid matter with which it is charged to the greatest distance.
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.
Torrents and the rivers that receive them transport mountain debris to almost
incredible distances. Lorentz, in an official report on this subject, as quoted by
Marschand from the Memoirs of the Agricultural Society of Lyons, 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.
[225] The precipitous walls of the Val de Lys, and more especially of the Val
Doveria, though here and there shattered, show in many places a smoothness of
face over a large vertical plane, at the height of hundreds of feet above the
bottom of the valley, which no known agency but glacier ice is capable of
producing, and of course they can have undergone no sensible change at those
points for a vast length of time. The beds of the rivers which flow through those
valleys suffer lateral displacement occasionally, where there is room for the
shifting of the channel; but if any elevation or depression takes place in them, it
is too slow to be perceptible except in case of some merely temporary
obstruction.
[226] 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 activity.—Notice sur les
Rivières de la Lombardie, Annales des Ponts et Chaussées, 1847, 1er sémestre,
p. 131.
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
solid matter with which it is charged to the greatest distance.
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.
Torrents and the rivers that receive them transport mountain debris to almost
incredible distances. Lorentz, in an official report on this subject, as quoted by
Marschand from the Memoirs of the Agricultural Society of Lyons, 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.
[225] The precipitous walls of the Val de Lys, and more especially of the Val
Doveria, though here and there shattered, show in many places a smoothness of
face over a large vertical plane, at the height of hundreds of feet above the
bottom of the valley, which no known agency but glacier ice is capable of
producing, and of course they can have undergone no sensible change at those
points for a vast length of time. The beds of the rivers which flow through those
valleys suffer lateral displacement occasionally, where there is room for the
shifting of the channel; but if any elevation or depression takes place in them, it
is too slow to be perceptible except in case of some merely temporary
obstruction.
[226] 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 activity.—Notice sur les
Rivières de la Lombardie, Annales des Ponts et Chaussées, 1847, 1er sémestre,
p. 131.
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
Page 434
change has been produced in the character or quantity of the matter transported
by them to the Po.
[227] 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. Many towns on the banks of the river, 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.—Baumgarten, after Lombardini, in
the paper last quoted, pp. 141, 147.
[228] Three centuries ago, 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, and, as appears by a passage of
Tasso quoted by Castellani (Dell' Influenza delle Selve, i, p. 58, note), they took
place in May. The much more violent inundations of the present century 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.
[229] 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 mètres less; but as both of them omit the gravel and silt rolled, if
not floated, down at ordinary and low water, we are safe in assuming the larger
quantity.—Article last quoted, p. 174. (See note, p. 329)
[230] Mengotti estimated the mass of solid matter annually "united to the
waters of the Po" at 822,000,000 cubic mètres, 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 Selve sul corso delle Acque, i, pp. 42, 43.
I have contented myself with assuming less than one fifth of Mengotti's
estimate.
[231] Baumgarten, An. des Ponts et Chaussées, 1847, 1er sémestre, p. 175.
by them to the Po.
[227] 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. Many towns on the banks of the river, 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.—Baumgarten, after Lombardini, in
the paper last quoted, pp. 141, 147.
[228] Three centuries ago, 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, and, as appears by a passage of
Tasso quoted by Castellani (Dell' Influenza delle Selve, i, p. 58, note), they took
place in May. The much more violent inundations of the present century 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.
[229] 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 mètres less; but as both of them omit the gravel and silt rolled, if
not floated, down at ordinary and low water, we are safe in assuming the larger
quantity.—Article last quoted, p. 174. (See note, p. 329)
[230] Mengotti estimated the mass of solid matter annually "united to the
waters of the Po" at 822,000,000 cubic mètres, 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 Selve sul corso delle Acque, i, pp. 42, 43.
I have contented myself with assuming less than one fifth of Mengotti's
estimate.
[231] Baumgarten, An. des Ponts et Chaussées, 1847, 1er sémestre, p. 175.
Page 435
[232] 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.
[233] I do not use the numbers I have borrowed or assumed 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 is 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 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.
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 of
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.
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,
used "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 the convent of St. Catherine to the summit
of Gebel Moosa counts "fifteen thousand" steps, though the difference of level is
barely 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
[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.
[233] I do not use the numbers I have borrowed or assumed 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 is 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 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.
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 of
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.
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,
used "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 the convent of St. Catherine to the summit
of Gebel Moosa counts "fifteen thousand" steps, though the difference of level is
barely 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
Page 436
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.
That most entertaining writer, About, reduces the number of rooms in the
Vatican, but he compensates this reduction by increased dimensions, for he uses
the word salle, which cannot be applied to closets barely large enough to contain
a bed. According to him, there are in that "presbytère," as he irreverently calls it,
twelve thousand large rooms [salles], thirty courts, and three hundred staircases.
—Rome Contemporaire, p. 68.
The pretended exactness of statistical tables is generally 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, but often
have a motive for distorting, the truth—such as census returns—are commonly
to be regarded as but vague guesses at the actual fact.
Fuller, who, for the combination of wit, wisdom, fancy, and personal
goodness, stands first in English literature, thus remarks on the pretentious
exactness of historical and statistical writers: "I approve the plain, country By-
word, as containing much Innocent Simplicity therein,
'Almost and very nigh
Have saved many a Lie.'
So have the Latines their prope, fere, juxta, circiter, plus minus, used in
matters of fact by the most authentic Historians. Yea, we may observe that the
Spirit of Truth itself, where Numbers and Measures are concerned, in Times,
Places, and Persons, useth the aforesaid Modifications, save in such cases where
some mystery contained in the number requireth a particular specification
thereof:
In Times. In Places. In Person.
Daniel, 5:33. Luke, 24:13. Exodus, 12:37.
Luke, 3:23. John, 6:19. Acts, 2:41.
None therefore can justly find fault with me, if, on the like occasion, I have
secured myself with the same Qualifications. Indeed, such Historians who grind
their Intelligence to the powder of fraction, pretending to cleave the pin, do
sometimes misse the But. Thus, one reporteth, how in the Persecution under
Dioeletian, there were neither under nor over, but just nine hundred ninety-nine
martyrs. Yea, generally those that trade in such Retail-ware, and deal in such
small parcells, may by the ignorant be commended for their care, but condemned
by the judicious for their ridiculous curiosity."—The History of the Worthies of
England, i, p. 59.
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.
That most entertaining writer, About, reduces the number of rooms in the
Vatican, but he compensates this reduction by increased dimensions, for he uses
the word salle, which cannot be applied to closets barely large enough to contain
a bed. According to him, there are in that "presbytère," as he irreverently calls it,
twelve thousand large rooms [salles], thirty courts, and three hundred staircases.
—Rome Contemporaire, p. 68.
The pretended exactness of statistical tables is generally 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, but often
have a motive for distorting, the truth—such as census returns—are commonly
to be regarded as but vague guesses at the actual fact.
Fuller, who, for the combination of wit, wisdom, fancy, and personal
goodness, stands first in English literature, thus remarks on the pretentious
exactness of historical and statistical writers: "I approve the plain, country By-
word, as containing much Innocent Simplicity therein,
'Almost and very nigh
Have saved many a Lie.'
So have the Latines their prope, fere, juxta, circiter, plus minus, used in
matters of fact by the most authentic Historians. Yea, we may observe that the
Spirit of Truth itself, where Numbers and Measures are concerned, in Times,
Places, and Persons, useth the aforesaid Modifications, save in such cases where
some mystery contained in the number requireth a particular specification
thereof:
In Times. In Places. In Person.
Daniel, 5:33. Luke, 24:13. Exodus, 12:37.
Luke, 3:23. John, 6:19. Acts, 2:41.
None therefore can justly find fault with me, if, on the like occasion, I have
secured myself with the same Qualifications. Indeed, such Historians who grind
their Intelligence to the powder of fraction, pretending to cleave the pin, do
sometimes misse the But. Thus, one reporteth, how in the Persecution under
Dioeletian, there were neither under nor over, but just nine hundred ninety-nine
martyrs. Yea, generally those that trade in such Retail-ware, and deal in such
small parcells, may by the ignorant be commended for their care, but condemned
by the judicious for their ridiculous curiosity."—The History of the Worthies of
England, i, p. 59.
Page 437
[234] Surell, 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 be ruined, like so many others."—Id., p. 155.
[235] 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, if 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.
315.
[236] 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 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. See
Appendix, No. 29.
[237] Palissy had observed the action of frost in disintegrating 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.
[238] Wessely, Die Oesterreichischen Alpenländer und ihre Forste, pp. 125,
126. Wessely records several other more or less similar occurrences in 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 be ruined, like so many others."—Id., p. 155.
[235] 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, if 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.
315.
[236] 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 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. See
Appendix, No. 29.
[237] Palissy had observed the action of frost in disintegrating 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.
[238] Wessely, Die Oesterreichischen Alpenländer und ihre Forste, pp. 125,
126. Wessely records several other more or less similar occurrences in the
Page 438
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.
[239] Bianchi, Appendix to the Italian translation of Mrs. Somerville's
Physical Geography, p. xxxvi.
[240] 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.
[241] Entwaldung der Gebirge, p. 41.
[242] 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.
[243] The tide rises at Quebec to the height of twenty-five feet, and when it
is aided by a northeast 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.
[244] One of these, the Baron of Renfrew—so named from one of the titles
of the kings of England—built thirty or forty 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 a recent 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.
New Brunswick, too, exports a large amount of lumber.
the woods, but in most cases they are clearly traceable to that cause.
[239] Bianchi, Appendix to the Italian translation of Mrs. Somerville's
Physical Geography, p. xxxvi.
[240] 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.
[241] Entwaldung der Gebirge, p. 41.
[242] 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.
[243] The tide rises at Quebec to the height of twenty-five feet, and when it
is aided by a northeast 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.
[244] One of these, the Baron of Renfrew—so named from one of the titles
of the kings of England—built thirty or forty 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 a recent 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.
New Brunswick, too, exports a large amount of lumber.
Page 439
[245] This name, from the French chantier, which has a wider meaning, is
applied in America to temporary huts or habitations erected for the convenience
of forest life, or in connection with works of material improvement.
[246] Trees differ much in their power of resisting the action of forest fires.
Different woods vary greatly in combustibility, and even when their bark is
scarcely scorched, they are, partly in consequence of physiological character, and
partly from the greater or less depth at which their roots habitually lie below the
surface, very 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.
[247] Between fifty and sixty years ago, a steep mountain with which I am
very 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 afterward. 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.
[248] The growth of the white pine, on a 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
applied in America to temporary huts or habitations erected for the convenience
of forest life, or in connection with works of material improvement.
[246] Trees differ much in their power of resisting the action of forest fires.
Different woods vary greatly in combustibility, and even when their bark is
scarcely scorched, they are, partly in consequence of physiological character, and
partly from the greater or less depth at which their roots habitually lie below the
surface, very 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.
[247] Between fifty and sixty years ago, a steep mountain with which I am
very 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 afterward. 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.
[248] The growth of the white pine, on a 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
Page 440
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 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. It could not have
been more than three inches through when transplanted, and must have increased
its diameter twenty-five inches in thirty-six years.
[249] 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.
[250] 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 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, Necessità dei Boschi,
pp. 17, 18.
[251] Caimi states that "a single flotation in the Valtelline in 1839, caused
damages alleged to amount to more than $800,000, and actually appraised at
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 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. It could not have
been more than three inches through when transplanted, and must have increased
its diameter twenty-five inches in thirty-six years.
[249] 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.
[250] 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 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, Necessità dei Boschi,
pp. 17, 18.
[251] Caimi states that "a single flotation in the Valtelline in 1839, caused
damages alleged to amount to more than $800,000, and actually appraised at
Page 441
$250,000."—Cenni sulla Importanza e Coltura dei Boschi, p. 65.
[252] Most 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. The lumbermen deny this. They affirm
that, while rivers are rising, the water is highest in the middle of the channel, and
tends to throw floating objects shoreward; while they are falling, it is lowest in
the middle, and floating objects incline toward 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.
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 superstitions. 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, I have
frequently conversed with sawyers on this subject, and have always been assured
by them that their uniform experience established the fact that, other things being
equal, the action of the machinery of sawmills is more rapid by night than by
day. I am sorry—perhaps I ought to be ashamed—to say that my scepticism has
been too strong to allow me to avail myself of my opportunities of testing this
question by passing a night, watch in hand, counting the strokes of a millsaw.
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 exact observer,
has repeatedly told me, that he had very often "timed" sawmills, and found the
difference in favor of night work above thirty per cent. Sed quære.
[253] For many instances of this sort, see 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 kept of the numbers of each species of tree, the document
is of interest in the history of the forest, as showing the relative proportions
between the different trees which composed the wood. See Vaupell. Bögens
Indvandring, p. 35, and Notes, p. 55.
[254] Since writing this paragraph, I have fallen upon—and that in a Spanish
author—one of those odd coincidences of thought which every man of
miscellaneous reading so often meets with. Antonio Ponz (Viage de España, i,
prólogo, p. 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
[252] Most 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. The lumbermen deny this. They affirm
that, while rivers are rising, the water is highest in the middle of the channel, and
tends to throw floating objects shoreward; while they are falling, it is lowest in
the middle, and floating objects incline toward 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.
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 superstitions. 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, I have
frequently conversed with sawyers on this subject, and have always been assured
by them that their uniform experience established the fact that, other things being
equal, the action of the machinery of sawmills is more rapid by night than by
day. I am sorry—perhaps I ought to be ashamed—to say that my scepticism has
been too strong to allow me to avail myself of my opportunities of testing this
question by passing a night, watch in hand, counting the strokes of a millsaw.
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 exact observer,
has repeatedly told me, that he had very often "timed" sawmills, and found the
difference in favor of night work above thirty per cent. Sed quære.
[253] For many instances of this sort, see 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 kept of the numbers of each species of tree, the document
is of interest in the history of the forest, as showing the relative proportions
between the different trees which composed the wood. See Vaupell. Bögens
Indvandring, p. 35, and Notes, p. 55.
[254] Since writing this paragraph, I have fallen upon—and that in a Spanish
author—one of those odd coincidences of thought which every man of
miscellaneous reading so often meets with. Antonio Ponz (Viage de España, i,
prólogo, p. 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
Page 442
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
vigorously 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 manière de dire, a popular phrase,
signifying simply that trees harbor birds.
[255] 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.
[256] 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 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.
[257] Histoire des Paysans, ii, p. 190. The work of Bonnemère is of great
value to those who study the history of mediæval 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. Bonnemère 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.
[258] 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.
[259] Guillaume de Nangis, as quoted in the notes to Joinville, Nouvelle
Collection des Mémoires, etc., par Michaud et Poujoulat, première série, i, p.
335.
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
vigorously 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 manière de dire, a popular phrase,
signifying simply that trees harbor birds.
[255] 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.
[256] 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 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.
[257] Histoire des Paysans, ii, p. 190. The work of Bonnemère is of great
value to those who study the history of mediæval 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. Bonnemère 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.
[258] 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.
[259] Guillaume de Nangis, as quoted in the notes to Joinville, Nouvelle
Collection des Mémoires, etc., par Michaud et Poujoulat, première série, i, p.
335.
Page 443
Persons acquainted with the character and influence of the mediæval 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
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."
[260] Histoire des Paysans, ii, p. 200.
[261] The following details from Bonnemère 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 Clavé, "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. They will lie motionless on the ground, by the roadside or in
thickets, for whole days, watching the paths most frequented by the animals,"
&c.—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.
[262] "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 Clavé, Études, p. 24.
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
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."
[260] Histoire des Paysans, ii, p. 200.
[261] The following details from Bonnemère 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 Clavé, "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. They will lie motionless on the ground, by the roadside or in
thickets, for whole days, watching the paths most frequented by the animals,"
&c.—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.
[262] "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 Clavé, Études, p. 24.
Page 444
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.
[263] "A hundred and fifty paces from my house is a hill of drift sand, on
which stood a few scattered pines. Pinus sylvestris, and 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, &c., 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 Silviæ 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 occidenialis 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 meadows by cutting
away the bushes. It formerly bore grass four feet high, because many
umbelliferous plants, such as Heracleum spondylium, Spiræa ulmaria,
Laserpitium latifolia, &c., grew in it. Under the shelter of the bushes these plants
ripened and bore seed, but they gradually disappeared as the shrubs were
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. Büttner, of Kurland, in Berghaus'
Geographisches 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 spoonfuls 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. Gérard, 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 ad libitum with the same, and finally
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.
[263] "A hundred and fifty paces from my house is a hill of drift sand, on
which stood a few scattered pines. Pinus sylvestris, and 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, &c., 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 Silviæ 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 occidenialis 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 meadows by cutting
away the bushes. It formerly bore grass four feet high, because many
umbelliferous plants, such as Heracleum spondylium, Spiræa ulmaria,
Laserpitium latifolia, &c., grew in it. Under the shelter of the bushes these plants
ripened and bore seed, but they gradually disappeared as the shrubs were
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. Büttner, of Kurland, in Berghaus'
Geographisches 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 spoonfuls 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. Gérard, 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 ad libitum with the same, and finally
Page 445
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'Année Scientifique,
1862, pp. 353, 384. See Appendix, No. 31.
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?
[264] Physikalische Geographie, p. 486.
[265] Origin of Species, American edition, p. 69.
[266] Writers on vegetable physiology record numerous instances where
seeds have grown after lying dormant for ages. The following cases, mentioned
by Dr. Dwight (Travels, ii, pp. 438, 439), may be new to many readers:
"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.
"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, &c. 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 fact that these white pines covered this
field exactly, so 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."
[267] 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 over-joyousness of thought. * * * In sum it is a very wild,
the Council of Health of the city of Paris. See Figuier, L'Année Scientifique,
1862, pp. 353, 384. See Appendix, No. 31.
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?
[264] Physikalische Geographie, p. 486.
[265] Origin of Species, American edition, p. 69.
[266] Writers on vegetable physiology record numerous instances where
seeds have grown after lying dormant for ages. The following cases, mentioned
by Dr. Dwight (Travels, ii, pp. 438, 439), may be new to many readers:
"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.
"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, &c. 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 fact that these white pines covered this
field exactly, so 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."
[267] 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 over-joyousness of thought. * * * In sum it is a very wild,
Page 446
wherein the wildness of human pride doth grow tame."—Ehre der Crain, i, p.
136, b.
[268] Valvasor says, in the same paragraph from which I have just quoted,
"In my many journeys through this valley, I did never have sight of so much as a
single bird."
[269] 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
plough lands. * * * 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.
[270] England is, I believe, the only country where private enterprise has
pursued sylviculture on a really great scale, though admirable examples have
been set in many others on both sides of the Atlantic. 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, and the difficulty of finding safe and profitable investments of
capital, combine to afford encouragements for the plantation of forests, which
nowhere else exist in the same degree. The climate of England, too, is very
favorable to the growth of forest trees, though the character of surface secures a
large part of the island from the evils which have resulted from the destruction of
the woods elsewhere, and therefore their restoration is a matter of less
geographical importance in England than on the Continent.
[271] The preservation of the woods on the eastern frontier of France, as a
kind of natural abattis, is also recognized by the Government of that country as
an important measure of military defence, though there have been conflicting
opinions on the subject.
[272] Let us take the supply of timber for railroad ties. According to Clavé
(p. 248), France has 9,000 kilomètres of railway in operation, 7,000 in
construction, half of which is built with a double track. Adding turnouts and
extra tracks at stations, the number of ties required for a single track is stated at
1,200 to the kilomètre, or, as Clavé computes, for the entire network of France,
58,000,000. As the schoolboys say, "this sum does not prove;" for 16,000 +
8,000 for the double track halfway = 24,000, and 24,000 × 1,200 = 28,800,000.
According to Bigelow (Les États Unis en 1863, p. 439), the United States had in
operation or construction on the first of January, 1862, 51,000 miles, or about
81,000 kilomètres of railroad, and the military operations of the present civil war
are rapidly extending the system. Allowing the same proportion as in France, the
American railroads required 97,200,000 ties in 1862. The consumption of timber
in Europe and America during the present generation, occasioned by this
136, b.
[268] Valvasor says, in the same paragraph from which I have just quoted,
"In my many journeys through this valley, I did never have sight of so much as a
single bird."
[269] 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
plough lands. * * * 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.
[270] England is, I believe, the only country where private enterprise has
pursued sylviculture on a really great scale, though admirable examples have
been set in many others on both sides of the Atlantic. 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, and the difficulty of finding safe and profitable investments of
capital, combine to afford encouragements for the plantation of forests, which
nowhere else exist in the same degree. The climate of England, too, is very
favorable to the growth of forest trees, though the character of surface secures a
large part of the island from the evils which have resulted from the destruction of
the woods elsewhere, and therefore their restoration is a matter of less
geographical importance in England than on the Continent.
[271] The preservation of the woods on the eastern frontier of France, as a
kind of natural abattis, is also recognized by the Government of that country as
an important measure of military defence, though there have been conflicting
opinions on the subject.
[272] Let us take the supply of timber for railroad ties. According to Clavé
(p. 248), France has 9,000 kilomètres of railway in operation, 7,000 in
construction, half of which is built with a double track. Adding turnouts and
extra tracks at stations, the number of ties required for a single track is stated at
1,200 to the kilomètre, or, as Clavé computes, for the entire network of France,
58,000,000. As the schoolboys say, "this sum does not prove;" for 16,000 +
8,000 for the double track halfway = 24,000, and 24,000 × 1,200 = 28,800,000.
According to Bigelow (Les États Unis en 1863, p. 439), the United States had in
operation or construction on the first of January, 1862, 51,000 miles, or about
81,000 kilomètres of railroad, and the military operations of the present civil war
are rapidly extending the system. Allowing the same proportion as in France, the
American railroads required 97,200,000 ties in 1862. The consumption of timber
in Europe and America during the present generation, occasioned by this
Page 447
demand, has required the sacrifice of many hundred thousand acres of forest, and
if we add the quantity employed for telegraph posts, we have an amount of
destruction, for entirely new purposes, which is really appalling.
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 demand for wood for small carvings and for children's toys is incredibly
large. Rentzsch states the export of such objects from the town of Sonneberg
alone to have amounted, in 1853, to 60,000 centner, or three thousand tons'
weight.—Der Wald, p. 68. See Appendix, No. 33.
The importance of so managing the forest that it may continue indefinitely to
furnish an adequate supply of material for naval architecture is well illustrated by
some remarks of the same author in the valuable little work just cited. He
suggests that the prosperity of modern England is due, in no small degree, to the
supplies of wood and other material for building and equipping ships, received
from the forests of her colonies and of other countries with which she has
maintained close commercial relations, and he adds: "Spain, which by her
position seemed destined for universal power, and once, in fact, possessed it, has
lost her political rank, because during the unwise administration of the
successors of Philip II, the empty exchequer could not furnish the means of
building new fleets; for the destruction of the forests had raised the price of
timber above the resources of the state."—Der Wald, p. 63.
The market price of timber, like that of all other commodities, may be said,
in a general way, to be regulated by the laws of demand and supply, but it is also
controlled by those seemingly unrelated accidents which so often disappoint the
calculations of political economists in other branches of commerce. A curious
case of this sort is noticed by Cerini, Dell' Impianto e Conservazione dei Boschi,
p. 17: "In the mountains on the Lago Maggiore, in years when maize is cheap,
the woodcutters can provide themselves with corn meal enough for a week by
three days' labor, and they refuse to work the remaining four. Hence the dealers
in wood, not being able to supply the demand, for want of laborers, are obliged
to raise the price for the following season, both for timber and for firewood; so
that a low price of grain occasions a high price of building lumber and of fuel.
The consequence is, that though the poor have supplied themselves cheaply with
food, they must pay dear for firewood, and they cannot get work, because the
high price of lumber has discouraged repairs and building, the expense of which
landed proprietors cannot undertake when their incomes have been reduced by
sales of grain at low rates, and hence there is not demand enough for lumber to
induce the timber merchants to furnish employment to the woodmen."
[273] 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
if we add the quantity employed for telegraph posts, we have an amount of
destruction, for entirely new purposes, which is really appalling.
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 demand for wood for small carvings and for children's toys is incredibly
large. Rentzsch states the export of such objects from the town of Sonneberg
alone to have amounted, in 1853, to 60,000 centner, or three thousand tons'
weight.—Der Wald, p. 68. See Appendix, No. 33.
The importance of so managing the forest that it may continue indefinitely to
furnish an adequate supply of material for naval architecture is well illustrated by
some remarks of the same author in the valuable little work just cited. He
suggests that the prosperity of modern England is due, in no small degree, to the
supplies of wood and other material for building and equipping ships, received
from the forests of her colonies and of other countries with which she has
maintained close commercial relations, and he adds: "Spain, which by her
position seemed destined for universal power, and once, in fact, possessed it, has
lost her political rank, because during the unwise administration of the
successors of Philip II, the empty exchequer could not furnish the means of
building new fleets; for the destruction of the forests had raised the price of
timber above the resources of the state."—Der Wald, p. 63.
The market price of timber, like that of all other commodities, may be said,
in a general way, to be regulated by the laws of demand and supply, but it is also
controlled by those seemingly unrelated accidents which so often disappoint the
calculations of political economists in other branches of commerce. A curious
case of this sort is noticed by Cerini, Dell' Impianto e Conservazione dei Boschi,
p. 17: "In the mountains on the Lago Maggiore, in years when maize is cheap,
the woodcutters can provide themselves with corn meal enough for a week by
three days' labor, and they refuse to work the remaining four. Hence the dealers
in wood, not being able to supply the demand, for want of laborers, are obliged
to raise the price for the following season, both for timber and for firewood; so
that a low price of grain occasions a high price of building lumber and of fuel.
The consequence is, that though the poor have supplied themselves cheaply with
food, they must pay dear for firewood, and they cannot get work, because the
high price of lumber has discouraged repairs and building, the expense of which
landed proprietors cannot undertake when their incomes have been reduced by
sales of grain at low rates, and hence there is not demand enough for lumber to
induce the timber merchants to furnish employment to the woodmen."
[273] 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
Page 448
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. Clavé
(Études Forestières, 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.
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 fire wood in Paris. In 1815, the supply of fire wood for the city required
1,200,000 stères, or cubic mètres; in 1859, it had fallen to 501,805, while, in the
mean time, the consumption of coal had risen from 600,000 to 432,000,000
metrical quintals. See Clavé, Études, p. 212.
I think there must be some error in this last sum, as 432 millions of metrical
quintals would amount to 43 millions of tons, a quantity which it is difficult to
suppose could be consumed in the city of Paris. The price of fire wood has
scarcely advanced at all in Paris for half a century, though that of timber
generally has risen enormously.
[274] In the first two years of the present civil war in the United States,
twenty-eight thousand walnut trees were felled to supply a single European
manufactory of gunstocks for the American market.
[275] 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 where there are now neither
wolves nor woods to shelter them. Arthur Young more than once speaks of the
connected with the end of the piece of timber subjected to the treatment. Clavé
(Études Forestières, 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.
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 fire wood in Paris. In 1815, the supply of fire wood for the city required
1,200,000 stères, or cubic mètres; in 1859, it had fallen to 501,805, while, in the
mean time, the consumption of coal had risen from 600,000 to 432,000,000
metrical quintals. See Clavé, Études, p. 212.
I think there must be some error in this last sum, as 432 millions of metrical
quintals would amount to 43 millions of tons, a quantity which it is difficult to
suppose could be consumed in the city of Paris. The price of fire wood has
scarcely advanced at all in Paris for half a century, though that of timber
generally has risen enormously.
[274] In the first two years of the present civil war in the United States,
twenty-eight thousand walnut trees were felled to supply a single European
manufactory of gunstocks for the American market.
[275] 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 where there are now neither
wolves nor woods to shelter them. Arthur Young more than once speaks of the
Page 449
"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.
[276] In the Recepte Véritable, 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, if they do but think, may see that without wood, it is not possible to
exercise any manner of human art or cunning."—Œuvres de Bernard Palissy,
p. 89.
[277] Since writing the above paragraph, I have found the view I have taken
of this point confirmed by the careful investigations 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 because at least her southern
provinces are more frequently visited both by extreme drought and by deluging
rains.
[278] Études sur l'Économie Forestière, p. 261. Clavé 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
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.
[276] In the Recepte Véritable, 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, if they do but think, may see that without wood, it is not possible to
exercise any manner of human art or cunning."—Œuvres de Bernard Palissy,
p. 89.
[277] Since writing the above paragraph, I have found the view I have taken
of this point confirmed by the careful investigations 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 because at least her southern
provinces are more frequently visited both by extreme drought and by deluging
rains.
[278] Études sur l'Économie Forestière, p. 261. Clavé 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
Page 450
winter, six or seven 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 the opening of a
new market for wood might raise the price of the fuel they employed for their
locomotives.
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 maintains that the
depression of the Caspian was produced by a sudden subsidence, from
geological 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 raise 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 evaporation from the surface of a champaign region, like that through
which the Volga, its tributaries, and the feeders of Lake Aral flow, is increased 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, a less
quantity of water may be delivered by them 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 basins.
[279] Rentzsch (Der Wald, etc., pp. 123, 124) states the proportions of
woodland in different European countries as follows:
Acres per Acres per
Per Per
head head
cent. cent.
of population. of population.
Germany 26.58 0.6638 Switzerland 15. 0.396
Great
5. 0.1 Holland 7.10 0.12
Britain
France 16.79 0.3766 Belgium 18.52 0.186
Russia 30.90 4.28 Spain 5.52 0.291
Sweden 60. 8.55 Portugal 4.40 0.182
Norway 66. 24.61 Sardinia 12.29 0.223
Denmark 5.50 0.22 Naples 9.43 0.138
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 the opening of a
new market for wood might raise the price of the fuel they employed for their
locomotives.
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 maintains that the
depression of the Caspian was produced by a sudden subsidence, from
geological 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 raise 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 evaporation from the surface of a champaign region, like that through
which the Volga, its tributaries, and the feeders of Lake Aral flow, is increased 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, a less
quantity of water may be delivered by them 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 basins.
[279] Rentzsch (Der Wald, etc., pp. 123, 124) states the proportions of
woodland in different European countries as follows:
Acres per Acres per
Per Per
head head
cent. cent.
of population. of population.
Germany 26.58 0.6638 Switzerland 15. 0.396
Great
5. 0.1 Holland 7.10 0.12
Britain
France 16.79 0.3766 Belgium 18.52 0.186
Russia 30.90 4.28 Spain 5.52 0.291
Sweden 60. 8.55 Portugal 4.40 0.182
Norway 66. 24.61 Sardinia 12.29 0.223
Denmark 5.50 0.22 Naples 9.43 0.138
Page 451
Probably 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, and the
general inclination of surface is not such as to expose it to special injury from
torrents. The due proportion of woodland in England and Ireland is, therefore,
almost purely an economical question, to be decided by the comparative direct
pecuniary return from forest growth, pasturage, and plough land.
In Scotland, where the country is for the most part more 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 that part of the French empire.
In giving the proportion of woodland to population, I compute Rentzsch's
Morgen at .3882 of an English acre, because I find, by Alexander's most accurate
and valuable Dictionary of Weights and Measures, that this is the value of the
Dresden Morgen, and Rentzsch is a Saxon writer. In the different German States,
there are more than twenty different land measures known by the name of
Morgen, varying from about one third of an acre to more than three acres in
value. When will the world be wise enough to unite in adopting the French
metrical and monetary systems? As to the latter, never while Christendom
continues to be ruled by money changers, who can compel you to part with your
sovereigns in France at twenty-five francs, and in England to accept fifteen
shillings for your napoleons. I speak as a sufferer. Experto crede Roberto.
[280] 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.
In the United States, swarms of honey bees, on leaving the parent hive, often
take up their quarters in hollow trees in the neighboring woods. By the early
customs of New England, the finder of a "bee tree" on the land of another owner
was regarded as entitled to the honey by right of discovery; and as a necessary
incident of that right, he might cut the tree, at the proper season, without asking
permission of the proprietor of the soil. The quantity of "wild honey" in a tree
was often large, and "bee hunting" was so profitable that it became almost a
their capacity of conservative influences, as England and Ireland. Their insular
position and latitude secure an abundance of atmospheric moisture, and the
general inclination of surface is not such as to expose it to special injury from
torrents. The due proportion of woodland in England and Ireland is, therefore,
almost purely an economical question, to be decided by the comparative direct
pecuniary return from forest growth, pasturage, and plough land.
In Scotland, where the country is for the most part more 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 that part of the French empire.
In giving the proportion of woodland to population, I compute Rentzsch's
Morgen at .3882 of an English acre, because I find, by Alexander's most accurate
and valuable Dictionary of Weights and Measures, that this is the value of the
Dresden Morgen, and Rentzsch is a Saxon writer. In the different German States,
there are more than twenty different land measures known by the name of
Morgen, varying from about one third of an acre to more than three acres in
value. When will the world be wise enough to unite in adopting the French
metrical and monetary systems? As to the latter, never while Christendom
continues to be ruled by money changers, who can compel you to part with your
sovereigns in France at twenty-five francs, and in England to accept fifteen
shillings for your napoleons. I speak as a sufferer. Experto crede Roberto.
[280] 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.
In the United States, swarms of honey bees, on leaving the parent hive, often
take up their quarters in hollow trees in the neighboring woods. By the early
customs of New England, the finder of a "bee tree" on the land of another owner
was regarded as entitled to the honey by right of discovery; and as a necessary
incident of that right, he might cut the tree, at the proper season, without asking
permission of the proprietor of the soil. The quantity of "wild honey" in a tree
was often large, and "bee hunting" was so profitable that it became almost a
Page 452
regular profession. The "bee hunter" sallied forth with a small box containing
honey and a little vermilion. The bees which were attracted by the honey marked
themselves with the vermilion, and hence were more readily followed in their
homeward flight, and recognized when they returned a second time for booty.
When loaded with spoil, this insect returns to his hive by the shortest route, and
hence a straight line is popularly called in America a "bee line." By such a line,
the hunter followed the bees to their sylvan hive, marked the tree with his
initials, and returned to secure his prize in the autumn. When the right of the
"bee hunter" was at last disputed by the land proprietors, it was with difficulty
that judgments could be obtained, in inferior courts, in favor of the latter, and it
was only after repeated decisions of the higher legal tribunals that the superior
right of the owner of the soil was at last acquiesced in.
[281] Étude sur le Reboisement des Montagnes, p. 5.
[282] "In America," says Clavé (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, it 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," and 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."
[283] 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 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
honey and a little vermilion. The bees which were attracted by the honey marked
themselves with the vermilion, and hence were more readily followed in their
homeward flight, and recognized when they returned a second time for booty.
When loaded with spoil, this insect returns to his hive by the shortest route, and
hence a straight line is popularly called in America a "bee line." By such a line,
the hunter followed the bees to their sylvan hive, marked the tree with his
initials, and returned to secure his prize in the autumn. When the right of the
"bee hunter" was at last disputed by the land proprietors, it was with difficulty
that judgments could be obtained, in inferior courts, in favor of the latter, and it
was only after repeated decisions of the higher legal tribunals that the superior
right of the owner of the soil was at last acquiesced in.
[281] Étude sur le Reboisement des Montagnes, p. 5.
[282] "In America," says Clavé (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, it 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," and 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."
[283] 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 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
Page 453
wood of which is of extreme toughness and durability, is, of all trees indigenous
to Northeastern America, by far the most rapid in growth.
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.
Southey informs us, in "Espriella's Letters," that when a small quantity of
mahogany was brought to England, early in the last century, the cabinetmakers
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.
[284] Études Forestières, p. 7.
[285] Études Forestières, p. 7.
[286] For very 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.
[287] Although Spenser's catalogue of trees occurs in the first canto of the
first book of the "Faëry 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.
Enforst to seeke some covert nigh at hand,
A shadie grove not farr away they spide,
That promist ayde the tempest to withstand;
Whose loftie trees, yelad 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 entred
ar.
VIII.
to Northeastern America, by far the most rapid in growth.
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.
Southey informs us, in "Espriella's Letters," that when a small quantity of
mahogany was brought to England, early in the last century, the cabinetmakers
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.
[284] Études Forestières, p. 7.
[285] Études Forestières, p. 7.
[286] For very 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.
[287] Although Spenser's catalogue of trees occurs in the first canto of the
first book of the "Faëry 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.
Enforst to seeke some covert nigh at hand,
A shadie grove not farr away they spide,
That promist ayde the tempest to withstand;
Whose loftie trees, yelad 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 entred
ar.
VIII.
Page 454
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;
The warlike beech; the ash for nothing ill;
The fruitfull olive; and the platane round;
The carver holme; the maple seeldom inward
sound.
[288] 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, Économie 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.
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 of 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,
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;
The warlike beech; the ash for nothing ill;
The fruitfull olive; and the platane round;
The carver holme; the maple seeldom inward
sound.
[288] 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, Économie 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.
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 of 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,
Page 455
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, Économie Rurale de la France, p. 253.
I believe the varieties developed by cultivation are less numerous in the
walnut than in the chestnut, which latter tree is often grafted in Southern Europe.
[289] 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
cicatrization 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.
[290] 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 is 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 once 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 Clavé (p. 252), the annual product
of a forest of cork oaks is calculated at about 660 kilogrammes, worth 150
francs, 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 a 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 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.
[291] 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. I cannot give statistical details as to the number of any of the
trees in question, or as to the area they would cover if brought together in a given
country. 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
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, Économie Rurale de la France, p. 253.
I believe the varieties developed by cultivation are less numerous in the
walnut than in the chestnut, which latter tree is often grafted in Southern Europe.
[289] 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
cicatrization 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.
[290] 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 is 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 once 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 Clavé (p. 252), the annual product
of a forest of cork oaks is calculated at about 660 kilogrammes, worth 150
francs, 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 a 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 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.
[291] 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. I cannot give statistical details as to the number of any of the
trees in question, or as to the area they would cover if brought together in a given
country. 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
Page 456
cultivation of all these trees is 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 of olive oil per year, for the last twenty
years.
[292] It is hard to say how far the peculiar form of the graceful crown of this
pine is due to pruning. It is true that the extremities of the topmost branches are
rarely lopped, but the lateral boughs are almost uniformly removed to a very
considerable height, and it is not improbable that the shape of the top is thereby
affected.
[293] Besides this, in a country so diversified in surface—I wish we could
with the French say accidented—as Italy with the exception of the champaign
region drained by the Po, every new field of view requires either an
extraordinary coup d'œil in the spectator, or a long study, in order to master its
relief, its plans, its salient and retreating angles. In summer, 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.
[294] Copse, or coppice, from the French couper, to cut, signifies 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
its character of a forest crop.
[295] It has been recently 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 it is now said that small stumps, with the shoots attached, have been
sent to Germany, and recognized by able botanists as true natural products.
[296] 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 Clavé, "may arrive at the age of five or six hundred years in
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 of olive oil per year, for the last twenty
years.
[292] It is hard to say how far the peculiar form of the graceful crown of this
pine is due to pruning. It is true that the extremities of the topmost branches are
rarely lopped, but the lateral boughs are almost uniformly removed to a very
considerable height, and it is not improbable that the shape of the top is thereby
affected.
[293] Besides this, in a country so diversified in surface—I wish we could
with the French say accidented—as Italy with the exception of the champaign
region drained by the Po, every new field of view requires either an
extraordinary coup d'œil in the spectator, or a long study, in order to master its
relief, its plans, its salient and retreating angles. In summer, 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.
[294] Copse, or coppice, from the French couper, to cut, signifies 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
its character of a forest crop.
[295] It has been recently 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 it is now said that small stumps, with the shoots attached, have been
sent to Germany, and recognized by able botanists as true natural products.
[296] 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 Clavé, "may arrive at the age of five or six hundred years in
Page 457
full vigor, and attain dimensions which I have never seen surpassed; when,
however, they are wholly unmixed with other trees, they begin to 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.
The forests of Denmark, which, in modern times, have been succeeded by
the beech—a species more inclined to be exclusive than any other broad-leaved
tree—were composed of birches, oaks, firs, aspens, willows, hazel, and maple,
the first three being the leading species. At present, the beech greatly
predominates.—Vaupell, Bögens Indvandring, pp. 19, 20.
[297] Études Forestières, p. 89.
[298] 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, 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 is 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. Eugène 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
however, they are wholly unmixed with other trees, they begin to 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.
The forests of Denmark, which, in modern times, have been succeeded by
the beech—a species more inclined to be exclusive than any other broad-leaved
tree—were composed of birches, oaks, firs, aspens, willows, hazel, and maple,
the first three being the leading species. At present, the beech greatly
predominates.—Vaupell, Bögens Indvandring, pp. 19, 20.
[297] Études Forestières, p. 89.
[298] 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, 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 is 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. Eugène 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
Page 458
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.
Chevandier computes that, if the annual growth of the pine in the marshy soil
of the Vosges be represented by one, it will equal two in 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 constantly moist by
infiltration from running brooks.—Comptes Rendus à l'Académie des Sciences—
t. xix, Juillet, Dec., 1844, p. 167.
The effect of accidental irrigation is well shown in the growth of the trees
planted along the canals of irrigation which traverse the fields in many parts of
Italy. They flourish 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 diameter 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. I have seen an extraordinary growth produced in fir
trees by the application of soapsuds.
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.
Chevandier computes that, if the annual growth of the pine in the marshy soil
of the Vosges be represented by one, it will equal two in 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 constantly moist by
infiltration from running brooks.—Comptes Rendus à l'Académie des Sciences—
t. xix, Juillet, Dec., 1844, p. 167.
The effect of accidental irrigation is well shown in the growth of the trees
planted along the canals of irrigation which traverse the fields in many parts of
Italy. They flourish 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 diameter 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. I have seen an extraordinary growth produced in fir
trees by the application of soapsuds.
Page 459
[299] 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 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."—Lullin de Chateauvieux, Lettres sur
l'Italie, p. 113.
The removal of the shelter afforded by the brushwood and the pendulous
branches of trees permits drying and chilling winds to parch and cool the ground,
and of course injuriously affects the growth of the wood. But this is not all. The
tread of quadrupeds exposes and bruises the roots of the trees, which often die
from this cause, as any one may observe by following the paths made by cattle
through woodlands.
[300] 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 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 plough land, 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 Alpenländer und ihre Forste, p. 312.
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 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."—Lullin de Chateauvieux, Lettres sur
l'Italie, p. 113.
The removal of the shelter afforded by the brushwood and the pendulous
branches of trees permits drying and chilling winds to parch and cool the ground,
and of course injuriously affects the growth of the wood. But this is not all. The
tread of quadrupeds exposes and bruises the roots of the trees, which often die
from this cause, as any one may observe by following the paths made by cattle
through woodlands.
[300] 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 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 plough land, 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 Alpenländer und ihre Forste, p. 312.
Page 460
[301] Vaupell, Bögens 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."
The study of the natural order of succession in forest trees is of the utmost
importance in sylviculture, because it guides us in the selection of the species to
be employed in planting a new or restoring a decayed forest. 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 Europe, the larch, 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 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 particularly because it appears not to exhaust, but on the contrary to
enrich 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.
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 they are entirely independent of each other," and
each prescribes the same order of succession.—Bögens Indvandring, p. 42.
[302] When vigorous young locusts, of two or three inches in diameter, are
polled, they throw out a great number of very thick-leaved shoots, which arrange
themselves in a globular head, so unlike the natural crown of the acacia, that
persons familiar only with the untrained tree often take them for a different
species.
[303] 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
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."
The study of the natural order of succession in forest trees is of the utmost
importance in sylviculture, because it guides us in the selection of the species to
be employed in planting a new or restoring a decayed forest. 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 Europe, the larch, 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 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 particularly because it appears not to exhaust, but on the contrary to
enrich 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.
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 they are entirely independent of each other," and
each prescribes the same order of succession.—Bögens Indvandring, p. 42.
[302] When vigorous young locusts, of two or three inches in diameter, are
polled, they throw out a great number of very thick-leaved shoots, which arrange
themselves in a globular head, so unlike the natural crown of the acacia, that
persons familiar only with the untrained tree often take them for a different
species.
[303] 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
Page 461
quantity of grain and roots grown on ground ploughed and cultivated as regularly
and as laboriously as any other.
The 170,000,000 bushels of oats raised in the United States in 1860, and fed
to the 6,000,000 horses, the potatoes, the turnips, and the maize employed in
fattening the oxen, the sheep, and the swine slaughtered the 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.
[304] According to Clavé (Études, 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 Würtemberg 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 is partly explained by the fact that a considerable proportion of the
annual product of 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 it when eighty years old, would yield only
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 (p. 335) 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
annual growth would generally be estimated much higher.
[305] 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 in 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.
and as laboriously as any other.
The 170,000,000 bushels of oats raised in the United States in 1860, and fed
to the 6,000,000 horses, the potatoes, the turnips, and the maize employed in
fattening the oxen, the sheep, and the swine slaughtered the 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.
[304] According to Clavé (Études, 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 Würtemberg 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 is partly explained by the fact that a considerable proportion of the
annual product of 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 it when eighty years old, would yield only
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 (p. 335) 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
annual growth would generally be estimated much higher.
[305] 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 in 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.
Page 462
[306] It has been often asserted 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 allegation, nor can I refer to
any passage in Roman literature in which 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 Lucrine lake by
dikes.
[307] A friend has recently suggested to me an interesting illustration of the
applicability of military instrumentalities to pacific art. The sale of gunpowder in
the United States, he informs me, is smaller since the commencement of the
present rebellion than before, because the war has caused the suspension of many
public and private improvements, in the execution of which great quantities of
powder were used for blasting.
It is alleged that the same observation was made in France during the
Crimean war, and that, in general, not ten per cent. of the powder manufactured
on either side of the Atlantic is employed for military purposes.
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 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
reconnoissances 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.
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.
[308] Staring, Voormaals en Thans, p. 150.
[309] 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.
Lincolnshire was reclaimed by sea dikes under the government of the Romans. I
have found no ancient authority in support of this allegation, nor can I refer to
any passage in Roman literature in which 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 Lucrine lake by
dikes.
[307] A friend has recently suggested to me an interesting illustration of the
applicability of military instrumentalities to pacific art. The sale of gunpowder in
the United States, he informs me, is smaller since the commencement of the
present rebellion than before, because the war has caused the suspension of many
public and private improvements, in the execution of which great quantities of
powder were used for blasting.
It is alleged that the same observation was made in France during the
Crimean war, and that, in general, not ten per cent. of the powder manufactured
on either side of the Atlantic is employed for military purposes.
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 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
reconnoissances 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.
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.
[308] Staring, Voormaals en Thans, p. 150.
[309] 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.
Page 463
[310] Die Inseln und Marschen der Herzogthümer Schleswig und Holstein,
iii, p. 151.
[311] The purely agricultural island of Pelworm, off the coast of Schleswig,
containing about 10,000 acres, annually expends for the maintenance of its dikes
not less than £6,000 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.
[312] Staring, Voormaals en Thans, p. 163.
[313] Voormaals en Thans, pp. 150, 151.
[314] 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 Schlesw. Holst., iii, p. 262.
[315] The most instructive and entertaining of tourists, J. G. Kohl—so aptly
characterized by Davies as the "Herodotus of modern Europe"—furnishes a great
amount of interesting information on the dikes of the Low German seacoast, in
his Inseln und Marschen der Herzogthümer Schleswig und Holstein. I am
acquainted with no popular work on this subject which the reader can consult
with greater profit. See also Staring, Voormaals en Thans, and De Bodem van
Nederland, on the dikes of the Netherlands.
[316] The inclination varies from one foot rise in four of base to one foot in
fourteen.—Kohl, iii, p. 210.
[317] 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
iii, p. 151.
[311] The purely agricultural island of Pelworm, off the coast of Schleswig,
containing about 10,000 acres, annually expends for the maintenance of its dikes
not less than £6,000 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.
[312] Staring, Voormaals en Thans, p. 163.
[313] Voormaals en Thans, pp. 150, 151.
[314] 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 Schlesw. Holst., iii, p. 262.
[315] The most instructive and entertaining of tourists, J. G. Kohl—so aptly
characterized by Davies as the "Herodotus of modern Europe"—furnishes a great
amount of interesting information on the dikes of the Low German seacoast, in
his Inseln und Marschen der Herzogthümer Schleswig und Holstein. I am
acquainted with no popular work on this subject which the reader can consult
with greater profit. See also Staring, Voormaals en Thans, and De Bodem van
Nederland, on the dikes of the Netherlands.
[316] The inclination varies from one foot rise in four of base to one foot in
fourteen.—Kohl, iii, p. 210.
[317] 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
Page 464
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.
[318] 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 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.
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.
[318] 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 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.
Page 465
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, 1854,
adduces many facts and arguments to prove a slow sinking of the northern
provinces of Holland. Laveleye (Affaissement du sol et 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.
[319] 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 occasioned by drying and consolidation. On the coast
of 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.
[320] The principal engine—called the Leeghwater, from the name of an
engineer who had proposed the draining of the lake in 1641—was of 500 horse
power, and drove eleven pumps making six strokes per minute. Each pump
raised six cubic mètres, or nearly eight cubic yards of water to the stroke,
amounting in all to 23,760 cubic mètres, or above 31,000 cubic yards, the hour.
—Wild, Die Niederlande, i, p. 87.
[321] 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 beneath is exhausted by evaporation and
drainage, when they sink down upon the sand again. See Appendix, No. 40.
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 first
condition for the growth of the plants which compose the substance of turf and
discussed. Not to mention earlier geologists, Venema, in several essays, and
particularly in Het Dalen van de Noordelijke Kuststreken van ons Land, 1854,
adduces many facts and arguments to prove a slow sinking of the northern
provinces of Holland. Laveleye (Affaissement du sol et 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.
[319] 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 occasioned by drying and consolidation. On the coast
of 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.
[320] The principal engine—called the Leeghwater, from the name of an
engineer who had proposed the draining of the lake in 1641—was of 500 horse
power, and drove eleven pumps making six strokes per minute. Each pump
raised six cubic mètres, or nearly eight cubic yards of water to the stroke,
amounting in all to 23,760 cubic mètres, or above 31,000 cubic yards, the hour.
—Wild, Die Niederlande, i, p. 87.
[321] 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 beneath is exhausted by evaporation and
drainage, when they sink down upon the sand again. See Appendix, No. 40.
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 first
condition for the growth of the plants which compose the substance of turf and
Page 466
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 us Nuphar, Nymphæa, 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, Spiræa, Polystichum, Comarum,
Caltha, &c., &c. 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 yards 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 as Carex, Menyanthes, and others, and soon thickly 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 drijftil; in Overijssel, 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
mean time by men or cattle, trees and arborescent plants, Alnus, Salix, Myrica,
&c. appear, and these contribute 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 upon those 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
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 us Nuphar, Nymphæa, 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, Spiræa, Polystichum, Comarum,
Caltha, &c., &c. 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 yards 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 as Carex, Menyanthes, and others, and soon thickly 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 drijftil; in Overijssel, 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
mean time by men or cattle, trees and arborescent plants, Alnus, Salix, Myrica,
&c. appear, and these contribute 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 upon those 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
Page 467
many men have lived to mow grass where they had fished in their boyhood, and
to cut turf twice in the same spot.
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.
[322] A considerable work of this character is mentioned by Captain Gilliss
as having been executed in Chili, a country to which we should have hardly
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.
[323] Économie Rurale de la France, p. 289.
[324] In a note on a former page of this volume I noticed an observation of
Jacini, to the effect that the great Italian lakes discharge themselves partly by
infiltration beneath the hills which bound them. The amount of such infiltration
must depend much upon the hydrostatic pressure on the walls of the lake basins,
and, of course, the lowering of the surface of these lakes, by diminishing that
pressure, would diminish also the infiltration. It is now proposed to lower the
level of the Lake of Como some feet by deepening its outlet. It is possible that
the effect of this may manifest itself in a diminution of the water in springs and
fontanili or artesian wells in Lombardy. See Appendix, No. 43.
[325] Simonde, speaking of the Tuscan canals, observes: "But inundations
are not the only damage caused by the waters to the plains of Tuscany. Raised, as
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.
[326] Physikalische Geographie, p. 288. Draining by driving down stakes,
mentioned in a note in a chapter on the woods, ante, is a process of the same
to cut turf twice in the same spot.
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.
[322] A considerable work of this character is mentioned by Captain Gilliss
as having been executed in Chili, a country to which we should have hardly
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.
[323] Économie Rurale de la France, p. 289.
[324] In a note on a former page of this volume I noticed an observation of
Jacini, to the effect that the great Italian lakes discharge themselves partly by
infiltration beneath the hills which bound them. The amount of such infiltration
must depend much upon the hydrostatic pressure on the walls of the lake basins,
and, of course, the lowering of the surface of these lakes, by diminishing that
pressure, would diminish also the infiltration. It is now proposed to lower the
level of the Lake of Como some feet by deepening its outlet. It is possible that
the effect of this may manifest itself in a diminution of the water in springs and
fontanili or artesian wells in Lombardy. See Appendix, No. 43.
[325] Simonde, speaking of the Tuscan canals, observes: "But inundations
are not the only damage caused by the waters to the plains of Tuscany. Raised, as
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.
[326] Physikalische Geographie, p. 288. Draining by driving down stakes,
mentioned in a note in a chapter on the woods, ante, is a process of the same
Page 468
nature.
[327] "The simplest backwoodsman knows by experience that all cultivation
is impossible in the neighborhood of bogs and marshes. Why is a crop near the
borders of a marsh cut off by frost, while a field upon a hillock, a few stone's
throws from it, is spared?"—Lars Levi Læstadius, Om Uppodlingar i
Lappmarken, pp. 69, 74.
[328] Babinet condemns even the general draining of marshes. "Draining,"
says he, "has been much in fashion for some years. It has been a special object to
dry and fertilize marshy grounds. My opinion has always been that excessive
dryness is thus produced, and that other soils in the neighborhood are sterilized
in proportion."
[329] I ought perhaps to except the Mexicans and the 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.
[330] The necessity of irrigation in the great alluvial 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 rapidly 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. Is it 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?
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° 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
[327] "The simplest backwoodsman knows by experience that all cultivation
is impossible in the neighborhood of bogs and marshes. Why is a crop near the
borders of a marsh cut off by frost, while a field upon a hillock, a few stone's
throws from it, is spared?"—Lars Levi Læstadius, Om Uppodlingar i
Lappmarken, pp. 69, 74.
[328] Babinet condemns even the general draining of marshes. "Draining,"
says he, "has been much in fashion for some years. It has been a special object to
dry and fertilize marshy grounds. My opinion has always been that excessive
dryness is thus produced, and that other soils in the neighborhood are sterilized
in proportion."
[329] I ought perhaps to except the Mexicans and the 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.
[330] The necessity of irrigation in the great alluvial 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 rapidly 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. Is it 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?
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° 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
Page 469
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.
[331] 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, 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.
[332] "Forests," "woods," and "groves," are very 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.
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 and industrial habits which
characterized their ages and their country. See Appendix, No. 44.
Solomon anticipated Chevandier in the irrigation of forest trees: "I made me
pools of water, to water therewith the wood that bringeth forth trees."—
Ecclesiastes ii, 6.
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.
[331] 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, 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.
[332] "Forests," "woods," and "groves," are very 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.
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 and industrial habits which
characterized their ages and their country. See Appendix, No. 44.
Solomon anticipated Chevandier in the irrigation of forest trees: "I made me
pools of water, to water therewith the wood that bringeth forth trees."—
Ecclesiastes ii, 6.
Page 470
[333] One of these, upon Mount Hor, two stories in height, is still in such
preservation that I found not less than ten feet of water in it in the month of June,
1851.
The brook Ain Musa, which runs through the city of Petra and finally
disappears in the sands of Wadi el Araba, is a considerable river 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 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 unequivocal remains
of a sluice by which the water was diverted to the tunnel near the arch that
crosses the Sik. 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 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 toward Wadi el Araba.
[334] The authorities differ as to the extent of the cultivable and the
cultivated soil of Egypt. Lippincott's, or rather Thomas and Baldwin's, Gazetteer
—a work of careful research—estimates "the whole area comprised in the valley
[below the first cataract] and delta," at 11,000 square miles. Smith's Dictionary
of the Bible, article "Egypt," says: "Egypt has a superficies of about 9,582 square
geographical miles of soil, which the Nile either does or can water and fertilize.
This computation includes the river and lakes as well as sundry tracts which can
be inundated, and the whole space either cultivated or fit for cultivation is no
more than about 5,626 square miles." By geographical mile is here meant, I
suppose, the nautical mile of sixty to an equatorial degree, or about 2,025 yards.
The whole area, then, by this estimate, is 12,682 square statute or English miles,
that of the space "cultivated or fit for cultivation," 7,447. Smith's Dictionary of
Greek and Roman Geography, article "Ægyptus," gives 2,255 square miles as the
area of the valley between Syene and the bifurcation of the Nile, exclusive of the
Fayoom, which is estimated at 340. The area of the Delta is stated at 1,976
square miles between the main branches of the river, and, including the irrigated
lands east and west of those branches, at 4,500 square miles. This latter work
does not inform us whether these are statute or nautical miles, but nautical miles
must be intended.
Other writers give estimates differing considerably from those just cited. The
latest computations I have seen are those in the first volume of Kremer's
preservation that I found not less than ten feet of water in it in the month of June,
1851.
The brook Ain Musa, which runs through the city of Petra and finally
disappears in the sands of Wadi el Araba, is a considerable river 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 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 unequivocal remains
of a sluice by which the water was diverted to the tunnel near the arch that
crosses the Sik. 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 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 toward Wadi el Araba.
[334] The authorities differ as to the extent of the cultivable and the
cultivated soil of Egypt. Lippincott's, or rather Thomas and Baldwin's, Gazetteer
—a work of careful research—estimates "the whole area comprised in the valley
[below the first cataract] and delta," at 11,000 square miles. Smith's Dictionary
of the Bible, article "Egypt," says: "Egypt has a superficies of about 9,582 square
geographical miles of soil, which the Nile either does or can water and fertilize.
This computation includes the river and lakes as well as sundry tracts which can
be inundated, and the whole space either cultivated or fit for cultivation is no
more than about 5,626 square miles." By geographical mile is here meant, I
suppose, the nautical mile of sixty to an equatorial degree, or about 2,025 yards.
The whole area, then, by this estimate, is 12,682 square statute or English miles,
that of the space "cultivated or fit for cultivation," 7,447. Smith's Dictionary of
Greek and Roman Geography, article "Ægyptus," gives 2,255 square miles as the
area of the valley between Syene and the bifurcation of the Nile, exclusive of the
Fayoom, which is estimated at 340. The area of the Delta is stated at 1,976
square miles between the main branches of the river, and, including the irrigated
lands east and west of those branches, at 4,500 square miles. This latter work
does not inform us whether these are statute or nautical miles, but nautical miles
must be intended.
Other writers give estimates differing considerably from those just cited. The
latest computations I have seen are those in the first volume of Kremer's
Page 471
Ægypten, 1863. This author (pp. 6, 7) assigns to the Delta an area of 200 square
German geographical miles (fifteen to the degree); to all Lower Egypt, including,
of course, the Delta, 400 such miles. These numbers are equal, respectively, to
4,239 and 8,478 square statute miles, and the great lagoons are embraced in the
areas computed. Upper Egypt (above Cairo) is said (p. 11) to contain 4,000,000
feddan of culturfläche, or cultivable land. The feddan is stated (p. 37) to contain
7,333 square piks, the pik being 75 centimètres, and it therefore corresponds
almost exactly to the English acre. Hence, according to Kremer, the cultivable
soil of Upper Egypt is 6,250 square statute miles, or twice as much as the whole
area of the valley between Syene and the bifurcation of the Nile, according to
Smith's Dictionary of Greek and Roman Geography. I suspect that 4,000,000
feddan is erroneously given as the cultivable area of Upper Egypt alone, when in
fact it should be taken for the arable surface of both Lower and Upper Egypt; for
from the statistical tables in the same volume, it appears that 3,317,125 feddan,
or 5,253 square statute miles, were cultivated, in both geographical divisions, in
the year referred to in the tables, the date of which is not stated.
The area which the Nile would now cover at high water, if left to itself, is
greater than 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 "Ægyptus." But the industry of the Egyptians in
the days of the Pharaohs and the Ptolomies carried the Nile-water to large
provinces which have now been long abandoned and have relapsed into the
condition of a 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."
[335] A canal has been constructed, and new ones are in progress, to convey
water from the Nile to the city of Suez, and to various points on the line of the
ship canal, with the double purpose of supplying fresh water to the inhabitants
and laborers, and of irrigating the adjacent soil. The area of land which may be
thus reclaimed and fertilized is very large, but the actual quantity which it will be
found economically expedient to bring under cultivation cannot now be
determined.
[336] The so-called spring at Heliopolis is only a thread of water infiltrated
from the Nile or the canals.
[337] The date and the doum palm, the sont and many other acacias, the
caroub, the sycamore, and other trees, grow well in Egypt without irrigation, and
would doubtless spread through the entire valley in a few years.
[338] Wilkinson has shown that the cultivable soil of Egypt has not been
diminished by encroachment of the desert sands, or otherwise, but that, on the
contrary, it must have been increased since the age of the Pharaohs. The Gotha
German geographical miles (fifteen to the degree); to all Lower Egypt, including,
of course, the Delta, 400 such miles. These numbers are equal, respectively, to
4,239 and 8,478 square statute miles, and the great lagoons are embraced in the
areas computed. Upper Egypt (above Cairo) is said (p. 11) to contain 4,000,000
feddan of culturfläche, or cultivable land. The feddan is stated (p. 37) to contain
7,333 square piks, the pik being 75 centimètres, and it therefore corresponds
almost exactly to the English acre. Hence, according to Kremer, the cultivable
soil of Upper Egypt is 6,250 square statute miles, or twice as much as the whole
area of the valley between Syene and the bifurcation of the Nile, according to
Smith's Dictionary of Greek and Roman Geography. I suspect that 4,000,000
feddan is erroneously given as the cultivable area of Upper Egypt alone, when in
fact it should be taken for the arable surface of both Lower and Upper Egypt; for
from the statistical tables in the same volume, it appears that 3,317,125 feddan,
or 5,253 square statute miles, were cultivated, in both geographical divisions, in
the year referred to in the tables, the date of which is not stated.
The area which the Nile would now cover at high water, if left to itself, is
greater than 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 "Ægyptus." But the industry of the Egyptians in
the days of the Pharaohs and the Ptolomies carried the Nile-water to large
provinces which have now been long abandoned and have relapsed into the
condition of a 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."
[335] A canal has been constructed, and new ones are in progress, to convey
water from the Nile to the city of Suez, and to various points on the line of the
ship canal, with the double purpose of supplying fresh water to the inhabitants
and laborers, and of irrigating the adjacent soil. The area of land which may be
thus reclaimed and fertilized is very large, but the actual quantity which it will be
found economically expedient to bring under cultivation cannot now be
determined.
[336] The so-called spring at Heliopolis is only a thread of water infiltrated
from the Nile or the canals.
[337] The date and the doum palm, the sont and many other acacias, the
caroub, the sycamore, and other trees, grow well in Egypt without irrigation, and
would doubtless spread through the entire valley in a few years.
[338] Wilkinson has shown that the cultivable soil of Egypt has not been
diminished by encroachment of the desert sands, or otherwise, but that, on the
contrary, it must have been increased since the age of the Pharaohs. The Gotha
Page 472
Almanac for 1862 states the population of Egypt in 1859 at 5,125,000 souls; but
this must be a great exaggeration, even supposing the estimate to include the
inhabitants of Nubia, and of much other territory not geographically belonging to
Egypt. In general, the population of that country has been estimated at something
more than three millions, or about six hundred to the square mile; but with a
better government and better social institutions, the soil would sustain a much
greater number, and in fact it is believed that in ancient times its inhabitants were
twice, perhaps even thrice, as numerous as at present.
Wilkinson (Handbook for Travellers in Egypt, p. 10) observes that the total
population, which two hundred years ago was estimated at 4,000,000, amounted
till lately only to about 1,800,000 souls, having been reduced since 1800 from
2,500,000 to that number.
[339] 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 though, by canals and
embankments, man has done much to modify the natural distribution of the
waters of the Nile, and possibly has even transferred its channel from one side of
the valley to the other, yet the annual inundation is not his work, and the river
must have overflowed its banks 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 are much more likely to have been morasses than
sands.
[340] Memorie sui progetti per l'estensione dell' Irrigazione, etc., il
Politecnico, for January, 1863, p. 6.
[341] Niel, L'Agriculture des États Sardes, p. 232.
[342] Niel, Agriculture des États Sardes, p. 237. Lombardini's computation
just given allows eighty-one cubic mètres per day to the hectare, which,
supposing the season of irrigation to be one hundred days, is equal to a
precipitation of thirty-two inches. But in Lombardy, water is applied to some
crops during a longer period than one hundred days; and in the marcite it flows
over the ground even in winter.
this must be a great exaggeration, even supposing the estimate to include the
inhabitants of Nubia, and of much other territory not geographically belonging to
Egypt. In general, the population of that country has been estimated at something
more than three millions, or about six hundred to the square mile; but with a
better government and better social institutions, the soil would sustain a much
greater number, and in fact it is believed that in ancient times its inhabitants were
twice, perhaps even thrice, as numerous as at present.
Wilkinson (Handbook for Travellers in Egypt, p. 10) observes that the total
population, which two hundred years ago was estimated at 4,000,000, amounted
till lately only to about 1,800,000 souls, having been reduced since 1800 from
2,500,000 to that number.
[339] 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 though, by canals and
embankments, man has done much to modify the natural distribution of the
waters of the Nile, and possibly has even transferred its channel from one side of
the valley to the other, yet the annual inundation is not his work, and the river
must have overflowed its banks 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 are much more likely to have been morasses than
sands.
[340] Memorie sui progetti per l'estensione dell' Irrigazione, etc., il
Politecnico, for January, 1863, p. 6.
[341] Niel, L'Agriculture des États Sardes, p. 232.
[342] Niel, Agriculture des États Sardes, p. 237. Lombardini's computation
just given allows eighty-one cubic mètres per day to the hectare, which,
supposing the season of irrigation to be one hundred days, is equal to a
precipitation of thirty-two inches. But in Lombardy, water is applied to some
crops during a longer period than one hundred days; and in the marcite it flows
over the ground even in winter.
Page 473
According to Boussingault (Économie Rurale, ii, p. 246) grass grounds ought
to receive, in Germany, twenty-one centimètres 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 centimètres is applied, it receives about 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
centimètres applied twenty-five or thirty times, which corresponds with the
estimate just stated. Puvis adds—and, as our author thinks, with reason—that
this amount might be doubled without disadvantage.
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.
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, just now commenced—
which is to take its supply from the Po at Chivasso, fourteen or fifteen miles
below Turin—will furnish 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 icefields 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.
[343] 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.
Professor 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 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 its fertility."
to receive, in Germany, twenty-one centimètres 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 centimètres is applied, it receives about 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
centimètres applied twenty-five or thirty times, which corresponds with the
estimate just stated. Puvis adds—and, as our author thinks, with reason—that
this amount might be doubled without disadvantage.
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.
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, just now commenced—
which is to take its supply from the Po at Chivasso, fourteen or fifteen miles
below Turin—will furnish 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 icefields 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.
[343] 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.
Professor 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 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 its fertility."
Page 474
"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."
The first of the paragraphs just quoted is not 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 far 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.
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 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 is 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 toward 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. The 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 cities.
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."
The first of the paragraphs just quoted is not 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 far 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.
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 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 is 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 toward 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. The 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 cities.
Page 475
[344] Boussingault, Économie Rurale, ii, pp. 248, 249.
[345] The cultivation of rice is so prejudicial to health everywhere that
nothing but the necessities of a dense population can justify the sacrifice of life it
costs in countries where it is pursued.
It has been demonstrated by actual experiment, that even in Mississippi,
cotton can be advantageously raised by the white man without danger to health;
and in fact, a great deal of the cotton brought to the Vicksburg market for some
years past has been grown exclusively by white labor. There is no reason why the
cultivation of cotton should be a more unhealthy occupation in America than it is
in other countries where it was never dreamed of as dangerous, and no well-
informed American, in the Slave States or out of them, believes that the abolition
of slavery in the South would permanently diminish the cotton crop of those
States.
[346] L'Italie à propos de l'Exposition de Paris, p. 92.
[347] The very valuable memoirs of Lombardini, Cenni idrografi sulla
Lombardia, Intorno al sistema idraulico del Po, and other papers on similar
subjects, were published in periodicals little known out of Italy; and the
Idraulica Pratica of Mari has not, I believe, been translated into French or
English. These works, and other sources of information equally inaccessible out
of Italy, have been freely used by Baumgarten, in a memoir entitled Notice sur
les Rivières de la Lombardie, in the Annales des Ponts et Chaussées, 1847, 1er
sémestre, pp. 129 et seqq., and by Dumont, Des Travaux Publics dans leurs
Rapports avec l'Agriculture, note, viii, pp. 269 et seqq. For the convenience of
my readers, I shall use these two articles instead of the original authorities on
which they are founded.
[348] Sir John F. W. 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
Mediterranean by the Nile in twenty-four hours, at low water, is 150,566,392,368
cubic mètres; at high water, 705,514,667,440 cubic mètres. Taking the mean of
these two numbers, the average daily delivery of the Nile would be
428,081,059,808 cubic mètres, 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 many times more than any physical geographer has
ever estimated the quantity supplied by all the rivers on the face of the globe.
[349] The Drac, a torrent emptying into the Isère a little below Grenoble, has
discharged 5,200, the Isère, which receives it, 7,800 cubic yards, and the
Durance an equal quantity, per second.—Montluisant, Note sur les
[345] The cultivation of rice is so prejudicial to health everywhere that
nothing but the necessities of a dense population can justify the sacrifice of life it
costs in countries where it is pursued.
It has been demonstrated by actual experiment, that even in Mississippi,
cotton can be advantageously raised by the white man without danger to health;
and in fact, a great deal of the cotton brought to the Vicksburg market for some
years past has been grown exclusively by white labor. There is no reason why the
cultivation of cotton should be a more unhealthy occupation in America than it is
in other countries where it was never dreamed of as dangerous, and no well-
informed American, in the Slave States or out of them, believes that the abolition
of slavery in the South would permanently diminish the cotton crop of those
States.
[346] L'Italie à propos de l'Exposition de Paris, p. 92.
[347] The very valuable memoirs of Lombardini, Cenni idrografi sulla
Lombardia, Intorno al sistema idraulico del Po, and other papers on similar
subjects, were published in periodicals little known out of Italy; and the
Idraulica Pratica of Mari has not, I believe, been translated into French or
English. These works, and other sources of information equally inaccessible out
of Italy, have been freely used by Baumgarten, in a memoir entitled Notice sur
les Rivières de la Lombardie, in the Annales des Ponts et Chaussées, 1847, 1er
sémestre, pp. 129 et seqq., and by Dumont, Des Travaux Publics dans leurs
Rapports avec l'Agriculture, note, viii, pp. 269 et seqq. For the convenience of
my readers, I shall use these two articles instead of the original authorities on
which they are founded.
[348] Sir John F. W. 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
Mediterranean by the Nile in twenty-four hours, at low water, is 150,566,392,368
cubic mètres; at high water, 705,514,667,440 cubic mètres. Taking the mean of
these two numbers, the average daily delivery of the Nile would be
428,081,059,808 cubic mètres, 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 many times more than any physical geographer has
ever estimated the quantity supplied by all the rivers on the face of the globe.
[349] The Drac, a torrent emptying into the Isère a little below Grenoble, has
discharged 5,200, the Isère, which receives it, 7,800 cubic yards, and the
Durance an equal quantity, per second.—Montluisant, Note sur les
Page 476
Desséchements, etc., Annales des Ponts et Chaussées, 1833, 2me sémestre, p.
288.
The floods of some other French rivers 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 Ardèche. In some of its inundations it has
delivered above 9,500 cubic yards per second.—Belgrand, De l'Influence des
Forêts, etc., Annales des Ponts et Chaussées, 1854, 1er sémestre, p. 15, note.
[350] The original forests in which the basin of the Ardèche 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 Forestières 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.
[351] "There is no example of a coincidence between great floods of the
Ardèche and of the Rhone, all the known inundations of the former having taken
place when the latter was very low."—Mardigny, Mémoire sur les Inondations
des Rivières de l'Ardèche, p. 26.
I take this occasion to acknowledge myself indebted to the interesting
memoir just quoted for all the statements I make respecting the floods of the
Ardèche, except the comparison of the volume of its waters with that of the Nile,
and the computation with respect to the capacity required for reservoirs to be
constructed in its basin.
[352] 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 the 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. 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 a much later period.
See App., No. 47.
288.
The floods of some other French rivers 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 Ardèche. In some of its inundations it has
delivered above 9,500 cubic yards per second.—Belgrand, De l'Influence des
Forêts, etc., Annales des Ponts et Chaussées, 1854, 1er sémestre, p. 15, note.
[350] The original forests in which the basin of the Ardèche 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 Forestières 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.
[351] "There is no example of a coincidence between great floods of the
Ardèche and of the Rhone, all the known inundations of the former having taken
place when the latter was very low."—Mardigny, Mémoire sur les Inondations
des Rivières de l'Ardèche, p. 26.
I take this occasion to acknowledge myself indebted to the interesting
memoir just quoted for all the statements I make respecting the floods of the
Ardèche, except the comparison of the volume of its waters with that of the Nile,
and the computation with respect to the capacity required for reservoirs to be
constructed in its basin.
[352] 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 the 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. 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 a much later period.
See App., No. 47.
Page 477
[353] Mémoire sur les Inondations des Rivières de l'Ardèche, 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 Oesterreichischien Alpenländer, i, p. 113. See
Appendix, No. 48.
[354] Frisi, Del modo di regolare i Fiumi e i Torrenti, pp. 4-19.
[355] Surell, Étude sur les Torrents, pp. 31-36.
[356] Champion, Les Inondations en France, iii, p. 156, note.
[357] 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.
[358] Troy, Étude sur le Reboisement des Montagnes, §§ 6, 7, 21.
[359] For accounts of damage from the bursting of reservoirs, see Vallée,
Mémoire sur les Reservoirs d'Alimentation des Canaux, Annales des Ponts et
Chaussées, 1833, 1er sémestre, p. 261.
[360] 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 term is wanting to designate the phenomenon mentioned in the text.
[361] Mardigny, Mémoire sur les Inondations de l'Ardèche, p. 13.
[362] 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.
—Baumgarten, after Lombardini, Annales des Ponts et Chaussées, 1847, 1er
sémestre, p. 149.
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 Oesterreichischien Alpenländer, i, p. 113. See
Appendix, No. 48.
[354] Frisi, Del modo di regolare i Fiumi e i Torrenti, pp. 4-19.
[355] Surell, Étude sur les Torrents, pp. 31-36.
[356] Champion, Les Inondations en France, iii, p. 156, note.
[357] 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.
[358] Troy, Étude sur le Reboisement des Montagnes, §§ 6, 7, 21.
[359] For accounts of damage from the bursting of reservoirs, see Vallée,
Mémoire sur les Reservoirs d'Alimentation des Canaux, Annales des Ponts et
Chaussées, 1833, 1er sémestre, p. 261.
[360] 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 term is wanting to designate the phenomenon mentioned in the text.
[361] Mardigny, Mémoire sur les Inondations de l'Ardèche, p. 13.
[362] 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.
—Baumgarten, after Lombardini, Annales des Ponts et Chaussées, 1847, 1er
sémestre, p. 149.
Page 478
[363] 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.—Baumgarten, volume before cited, pp. 175, et seqq. See
Appendix, No. 49.
If the western coast of the Adriatic is undergoing a secular depression, as
many circumstances concur to prove, the sinking of the plain near the coast may
both tend to prevent the deposit of sediment in the river bed by increasing the
velocity of its current, and compensate the elevation really produced by deposits,
so that no sensible elevation would result, though much gravel and slime might
be let fall.
[364] To secure the city of Sacramento in California from the inundations to
which it is subject, a dike or levée 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
has been elevated much 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 its lower
parts.—Baumgarten, after Lombardini, volume before cited, p. 152.
[365] Moyens de forcer les Torrents de rendre une partie du sol qu'ils
ravagent, et d'empêcher les grandes Inondations.
[366] 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
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.—Baumgarten, volume before cited, pp. 175, et seqq. See
Appendix, No. 49.
If the western coast of the Adriatic is undergoing a secular depression, as
many circumstances concur to prove, the sinking of the plain near the coast may
both tend to prevent the deposit of sediment in the river bed by increasing the
velocity of its current, and compensate the elevation really produced by deposits,
so that no sensible elevation would result, though much gravel and slime might
be let fall.
[364] To secure the city of Sacramento in California from the inundations to
which it is subject, a dike or levée 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
has been elevated much 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 its lower
parts.—Baumgarten, after Lombardini, volume before cited, p. 152.
[365] Moyens de forcer les Torrents de rendre une partie du sol qu'ils
ravagent, et d'empêcher les grandes Inondations.
[366] 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
Page 479
along the mountains do much deaden the violence of the waters that flow from
them."
[367] 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, 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, while
its waters will follow the lowest lines of the surface, will 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 southward in consequence of the superior 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.
[368] The distance to which a new obstruction to the flow of a river, whether
by a dam or by a deposit in its 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
watermills have been erected within a few years, and there is scarcely a stream in
the settled portion of the country which has not several milldams 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 lawsuits. 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 subterranean courses of the waters form a subject very difficult of
investigation, and it is only recently that its vast importance has been recognized.
them."
[367] 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, 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, while
its waters will follow the lowest lines of the surface, will 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 southward in consequence of the superior 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.
[368] The distance to which a new obstruction to the flow of a river, whether
by a dam or by a deposit in its 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
watermills have been erected within a few years, and there is scarcely a stream in
the settled portion of the country which has not several milldams 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 lawsuits. 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 subterranean courses of the waters form a subject very difficult of
investigation, and it is only recently that its vast importance has been recognized.
Page 480
The interesting observations of Schmidt on the caves of the Karst and their rivers
throw much light on the underground hydrography of limestone districts, and
serve to explain how, in the low peninsula of Florida, rivers, which must have
their sources in mountains a hundred or more miles distant, can pour out of the
earth in currents large enough to admit of steamboat navigation to their very
basins of eruption. Artesian wells are revealing to us the existence of
subterranean lakes and rivers sometimes superposed one above another in
successive sheets; but the still more important subject of the absorption of water
by earth and its transmission by infiltration is yet wrapped in great obscurity.
[369] 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 Ferrarese. Annali di Agricoltura, etc.,
Fasc. v, 1863.
[370] 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 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 Takazzé.
[371] It is very probably true that, as Lombardini supposes, the plain of
Lombardy was anciently covered with forests and morasses (Baumgarten, l. c. p.
156); but, had the Po remained unconfined, its deposits would have raised its
banks as fast as its bed, and there is no obvious reason why this plain should be
more marshy than other alluvial flats traversed by great rivers. Its lower course
would possibly have become more marshy than at present, but the banks of its
middle and upper course would have been in a better condition for agricultural
use than they now are.
[372] 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 mètres, or 60,745 cubic feet, per second.
Its smallest delivery is 186 cubic mètres, or 6,569 cubic feet, its greatest 5,156
cubic mètres, or 182,094 cubic feet.—Baumgarten, following Lombardini,
volume before cited, p. 159.
throw much light on the underground hydrography of limestone districts, and
serve to explain how, in the low peninsula of Florida, rivers, which must have
their sources in mountains a hundred or more miles distant, can pour out of the
earth in currents large enough to admit of steamboat navigation to their very
basins of eruption. Artesian wells are revealing to us the existence of
subterranean lakes and rivers sometimes superposed one above another in
successive sheets; but the still more important subject of the absorption of water
by earth and its transmission by infiltration is yet wrapped in great obscurity.
[369] 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 Ferrarese. Annali di Agricoltura, etc.,
Fasc. v, 1863.
[370] 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 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 Takazzé.
[371] It is very probably true that, as Lombardini supposes, the plain of
Lombardy was anciently covered with forests and morasses (Baumgarten, l. c. p.
156); but, had the Po remained unconfined, its deposits would have raised its
banks as fast as its bed, and there is no obvious reason why this plain should be
more marshy than other alluvial flats traversed by great rivers. Its lower course
would possibly have become more marshy than at present, but the banks of its
middle and upper course would have been in a better condition for agricultural
use than they now are.
[372] 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 mètres, or 60,745 cubic feet, per second.
Its smallest delivery is 186 cubic mètres, or 6,569 cubic feet, its greatest 5,156
cubic mètres, or 182,094 cubic feet.—Baumgarten, following Lombardini,
volume before cited, p. 159.
Page 481
The average delivery of the Nile being 101,000 cubic feet per second, it
follows that the Po contributes to the Adriatic six tenths as much water as the
Nile to the Mediterranean—a result which will surprise most readers.
[373] 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.
[374] There are many dikes in Egypt, but they are employed in but a very
few cases to exclude the waters of the inundation. Their office is to retain the
water received at high Nile into the inclosures formed by them until it shall have
deposited its sediment or been drawn out for irrigation; and they serve also as
causeways for interior communication during the floods. The Egyptian dikes,
therefore, instead of forcing the river, like those of the Po, to transport its
sediment to the sea, help to retain the slime, which, if the flow of the current
over the land were not obstructed, might be carried back into the channel, and at
last to the Mediterranean.
[375] The Mediterranean front of the Delta may be estimated at one hundred
and fifty miles in length. Two cubic miles of earth would more than fill up the
lagoons on the coast, and the remaining ten, even allowing the mean depth of the
water to be twenty fathoms, which is beyond the truth, would have been
sufficient to extend the coast line about three miles farther seaward, and thus,
including the land gained by the filling up of the lagoons, to add more than five
hundred square miles to the area of Egypt. Nor is this all; for the retardation of
the current, by lengthening the course and consequently diminishing the
inclination of the channel, would have increased the deposit of suspended matter,
and proportionally augmented the total effect of the embankment.
[376] For the convenience of navigation, and to lessen the danger of
inundation by giving greater directness, and, of course, rapidity to the current,
bends in rivers are sometimes cut off and winding channels made straight. This
process has the same general effects as diking, and therefore cannot be employed
without many of the same results.
This practice has often 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 sediment in the
follows that the Po contributes to the Adriatic six tenths as much water as the
Nile to the Mediterranean—a result which will surprise most readers.
[373] 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.
[374] There are many dikes in Egypt, but they are employed in but a very
few cases to exclude the waters of the inundation. Their office is to retain the
water received at high Nile into the inclosures formed by them until it shall have
deposited its sediment or been drawn out for irrigation; and they serve also as
causeways for interior communication during the floods. The Egyptian dikes,
therefore, instead of forcing the river, like those of the Po, to transport its
sediment to the sea, help to retain the slime, which, if the flow of the current
over the land were not obstructed, might be carried back into the channel, and at
last to the Mediterranean.
[375] The Mediterranean front of the Delta may be estimated at one hundred
and fifty miles in length. Two cubic miles of earth would more than fill up the
lagoons on the coast, and the remaining ten, even allowing the mean depth of the
water to be twenty fathoms, which is beyond the truth, would have been
sufficient to extend the coast line about three miles farther seaward, and thus,
including the land gained by the filling up of the lagoons, to add more than five
hundred square miles to the area of Egypt. Nor is this all; for the retardation of
the current, by lengthening the course and consequently diminishing the
inclination of the channel, would have increased the deposit of suspended matter,
and proportionally augmented the total effect of the embankment.
[376] For the convenience of navigation, and to lessen the danger of
inundation by giving greater directness, and, of course, rapidity to the current,
bends in rivers are sometimes cut off and winding channels made straight. This
process has the same general effects as diking, and therefore cannot be employed
without many of the same results.
This practice has often 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 sediment in the
Page 482
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 reduce the distance
between their termini by several miles. In 1777, the salto of Cottaro shortened a
distance of 7,000 mètres by 5,000, or, in other words, reduced the length of the
channel more than three miles; and in 1807 and 1810 the two salti of Mezzanone
effected a reduction of distance to the amount of between seven and eight miles.
—Baumgarten, l. c. p. 38.
[377] The fact, that the mixing of salt and fresh water in coast marshes and
lagoons is deleterious to the sanitary condition of the vicinity, seems almost
universally 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
miasmata. 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 sul Bonificamento delle Maremme Toscane. See also the
Memorie Economico-Statistiche sulle Maremme Toscane, of the same author.
[378] 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 almost all European countries, the swallow is protected, by popular
opinion or superstition, from the persecution to which almost all other birds are
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
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 reduce the distance
between their termini by several miles. In 1777, the salto of Cottaro shortened a
distance of 7,000 mètres by 5,000, or, in other words, reduced the length of the
channel more than three miles; and in 1807 and 1810 the two salti of Mezzanone
effected a reduction of distance to the amount of between seven and eight miles.
—Baumgarten, l. c. p. 38.
[377] The fact, that the mixing of salt and fresh water in coast marshes and
lagoons is deleterious to the sanitary condition of the vicinity, seems almost
universally 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
miasmata. 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 sul Bonificamento delle Maremme Toscane. See also the
Memorie Economico-Statistiche sulle Maremme Toscane, of the same author.
[378] 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 almost all European countries, the swallow is protected, by popular
opinion or superstition, from the persecution to which almost all other birds are
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
Page 483
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 following little Tuscan rispetto from Gradi (Racconti Popolari, p. 33)
well expresses the feeling of the peasantry toward this bird:
O rondinella che passi lo mare
Torna 'ndietro, vo' dirti du' parole;
Dammi 'na penna delle tue bell' ale,
Vo' scrivere 'na lettera al mi' amore;
E quando l' avrò scritta 'n carta bella,
Ti renderò la penna, o rondinella;
E quando l' avrò scritta 'n carta bianca,
Ti renderò la penna che ti manca;
E quando l' avrò scritta in carta d' oro,
Ti renderò la penna al tuo bel volo.
O swallow, that fliest beyond the sea,
Turn back! I would fain have a word with thee.
A feather oh grant, from thy wing so bright!
For I to my sweetheart a letter would write;
And when it is written on paper fine
I'll give thee, O swallow, that feather of thine;
—On paper so white, and I'll give thee back,
O pretty swallow, the pen thou dost lack;
—On paper of gold, and then I'll restore
To thy beautiful pinion the feather once more.
Popular traditions and superstitions are so closely connected with localities,
that, though an emigrant people may carry them to a foreign land, they seldom
survive a second generation. The swallow, however, is still protected in New
England by prejudices of transatlantic origin; and I remember hearing, in my
childhood, that if the swallows were killed, the cows would give bloody milk.
[379] Morozzi, Dello stato antico e moderno del fiume Arno, ii, p. 42.
[380] Morozzi, Dello stato, etc., dell' Arno, ii, pp. 39, 40.
[381] 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, Memorie sopra la Val di Chiana, p. 219.
[382] 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.
kill them, because they are le gallinelle del Signore, the chickens of the Lord.
The following little Tuscan rispetto from Gradi (Racconti Popolari, p. 33)
well expresses the feeling of the peasantry toward this bird:
O rondinella che passi lo mare
Torna 'ndietro, vo' dirti du' parole;
Dammi 'na penna delle tue bell' ale,
Vo' scrivere 'na lettera al mi' amore;
E quando l' avrò scritta 'n carta bella,
Ti renderò la penna, o rondinella;
E quando l' avrò scritta 'n carta bianca,
Ti renderò la penna che ti manca;
E quando l' avrò scritta in carta d' oro,
Ti renderò la penna al tuo bel volo.
O swallow, that fliest beyond the sea,
Turn back! I would fain have a word with thee.
A feather oh grant, from thy wing so bright!
For I to my sweetheart a letter would write;
And when it is written on paper fine
I'll give thee, O swallow, that feather of thine;
—On paper so white, and I'll give thee back,
O pretty swallow, the pen thou dost lack;
—On paper of gold, and then I'll restore
To thy beautiful pinion the feather once more.
Popular traditions and superstitions are so closely connected with localities,
that, though an emigrant people may carry them to a foreign land, they seldom
survive a second generation. The swallow, however, is still protected in New
England by prejudices of transatlantic origin; and I remember hearing, in my
childhood, that if the swallows were killed, the cows would give bloody milk.
[379] Morozzi, Dello stato antico e moderno del fiume Arno, ii, p. 42.
[380] Morozzi, Dello stato, etc., dell' Arno, ii, pp. 39, 40.
[381] 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, Memorie sopra la Val di Chiana, p. 219.
[382] 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.
Page 484
[383] This difficulty has been remedied 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.
The annual amount of sediment brought down by the rivers of the Maremma
is computed at more than 12,000,000 cubic yards, or enough to raise an area of
four square miles one yard. Between 1830 and 1859 more than three times that
quantity was deposited in the marsh and shoal water lake of Castiglione alone.—
Salvagnoli, Raccolta di Documenti, pp. 74, 75.
[384] The tide rises ten inches on the coast of Tuscany. See Memoir by
Fantoni, in the appendix to Salvagnoli, Rapporto, p. 189.
On the tides of the Mediterranean, see Böttger, Das Mittelmeer, p. 190. Not
having Admiral Smyth's Mediterranean—on which Böttger's work is founded—
at hand, I do not know how far credit is due to the former author for the matter
contained in the chapter referred to.
[385] 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 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 as inviolable. The rights of fishery were a
standing obstacle to every proposal of hydraulic 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.
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.
The annual amount of sediment brought down by the rivers of the Maremma
is computed at more than 12,000,000 cubic yards, or enough to raise an area of
four square miles one yard. Between 1830 and 1859 more than three times that
quantity was deposited in the marsh and shoal water lake of Castiglione alone.—
Salvagnoli, Raccolta di Documenti, pp. 74, 75.
[384] The tide rises ten inches on the coast of Tuscany. See Memoir by
Fantoni, in the appendix to Salvagnoli, Rapporto, p. 189.
On the tides of the Mediterranean, see Böttger, Das Mittelmeer, p. 190. Not
having Admiral Smyth's Mediterranean—on which Böttger's work is founded—
at hand, I do not know how far credit is due to the former author for the matter
contained in the chapter referred to.
[385] 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 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 as inviolable. The rights of fishery were a
standing obstacle to every proposal of hydraulic 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.
Page 485
[386] 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.
[387] Giorgini, Sur les causes de l'Insalubrité de l'air dans le voisinage des
marais, etc., lue à l'Académie des Sciences à Paris, le 12 Juillet, 1825. Reprinted
in Salvagnoli, Rapporto, etc., appendice, p. 5, et seqq.
[388] See the careful estimates of Roset, Moyens de forcer les Torrents, etc.,
pp. 42, 44.
[389] 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 West 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, l. c., p. 132.
[390] "The stream carries this mud, &c., 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 the Syrian coast, in consequence of
which Tyre and Sidon 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. A somewhat alarming phenomenon was observed in this
neighborhood in 1801, on board the English frigate Romulus, Captain
Culverhouse, on a voyage from Acre to Abukir. Dr. E. D. Clarke, who was a
passenger on board this ship, thus describes it:
"'26th July.—To-day, Sunday, we accompanied the captain to the wardroom
to dine, as usual, with his officers. While we were at table, we heard the sailors
who were throwing the lead suddenly cry out: "Three and a half!" The captain
sprang up, was on deck in an instant, and, almost at the same moment, the ship
slackened her way, and veered about. Every sailor on board supposed she would
ground at once. Meanwhile, however, as the ship 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 masthead—nor was any notice of such a shoal to be
found on any chart on board. The fact is, as we learned afterward, 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
forward 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,
should restore the wholesomeness of the soil by cultivation, and purify the air by
fires."—Salvagnoli, Memorie, p. 111.
[387] Giorgini, Sur les causes de l'Insalubrité de l'air dans le voisinage des
marais, etc., lue à l'Académie des Sciences à Paris, le 12 Juillet, 1825. Reprinted
in Salvagnoli, Rapporto, etc., appendice, p. 5, et seqq.
[388] See the careful estimates of Roset, Moyens de forcer les Torrents, etc.,
pp. 42, 44.
[389] 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 West 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, l. c., p. 132.
[390] "The stream carries this mud, &c., 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 the Syrian coast, in consequence of
which Tyre and Sidon 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. A somewhat alarming phenomenon was observed in this
neighborhood in 1801, on board the English frigate Romulus, Captain
Culverhouse, on a voyage from Acre to Abukir. Dr. E. D. Clarke, who was a
passenger on board this ship, thus describes it:
"'26th July.—To-day, Sunday, we accompanied the captain to the wardroom
to dine, as usual, with his officers. While we were at table, we heard the sailors
who were throwing the lead suddenly cry out: "Three and a half!" The captain
sprang up, was on deck in an instant, and, almost at the same moment, the ship
slackened her way, and veered about. Every sailor on board supposed she would
ground at once. Meanwhile, however, as the ship 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 masthead—nor was any notice of such a shoal to be
found on any chart on board. The fact is, as we learned afterward, 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
forward 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,
Page 486
misled by his soundings, would every moment expect to be stranded.'"—
Böttger, Das Mittelmeer, pp. 188, 189.
[391] The caves of Carniola receive considerable rivers from the surface of
the earth, which cannot, in all cases, be identified with streams flowing out of
them at other points, and like phenomena are not uncommon in other limestone
countries.
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 streams 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 the width 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 that
there is no refluent current, as of course there could not be from a basin 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. 19, pp. 129, et seqq. See Appendix, No. 53.
[392] "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
Böttger, Das Mittelmeer, pp. 188, 189.
[391] The caves of Carniola receive considerable rivers from the surface of
the earth, which cannot, in all cases, be identified with streams flowing out of
them at other points, and like phenomena are not uncommon in other limestone
countries.
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 streams 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 the width 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 that
there is no refluent current, as of course there could not be from a basin 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. 19, pp. 129, et seqq. See Appendix, No. 53.
[392] "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
Page 487
improvement of the navigation of the Seine between Paris and Rouen, has
devoted much attention to it."—Babinet, Études et Lectures, iii, p. 185.
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.
[393] Girard and Duchatelet maintain that the subterranean waters of Paris
are absolutely stagnant. See their report on drainage by artesian wells, Annales
des Ponts et Chaussées, 1833, 2me sémestre, pp. 313, et seqq.
This opinion, if locally true, cannot be generally so, for it is inconsistent with
the well-known fact that the very first eruption of water from a boring often
brings up leaves and other objects which must have been carried into the
underground reservoirs by currents.
[394] Physikalische Geographie, p. 286. It does not appear whether this
inference is Mariotte's or Wittwer's. I suppose it is a conclusion of the latter.
[395] Physical Geography of the Sea. Tenth edition. London, 1861, § 274.
[396] Paramelle, Quellenkunde, mit einem Vorwort von B. Cotta, 1856.
[397] Études et Lectures, vi, p. 118.
[398] "The area of soil dried by draining is constantly increasing, and the
water received by the surface from atmospheric precipitation is thereby partly
conducted into new channels, and, in general, carried off more rapidly than
before. Will not this fact exert an influence on the condition of many springs,
whose basin of supply thus undergoes a partial or complete transformation? I am
convinced that it will, and it is important to collect data for solving the question."
Bernhard Cotta, Preface to Paramelle, Quellenkunde (German translation),
pp. vii, viii. See Appendix, No. 54.
[399] See the interesting observations of Kriegk on this subject, Schriften
zur allgemeinen Erdkunde, cap. iii, § 6, and especially the passages in Ritter's
Erdkunde, vol. i, there referred to.
Laurent, (Mémoires 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
devoted much attention to it."—Babinet, Études et Lectures, iii, p. 185.
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.
[393] Girard and Duchatelet maintain that the subterranean waters of Paris
are absolutely stagnant. See their report on drainage by artesian wells, Annales
des Ponts et Chaussées, 1833, 2me sémestre, pp. 313, et seqq.
This opinion, if locally true, cannot be generally so, for it is inconsistent with
the well-known fact that the very first eruption of water from a boring often
brings up leaves and other objects which must have been carried into the
underground reservoirs by currents.
[394] Physikalische Geographie, p. 286. It does not appear whether this
inference is Mariotte's or Wittwer's. I suppose it is a conclusion of the latter.
[395] Physical Geography of the Sea. Tenth edition. London, 1861, § 274.
[396] Paramelle, Quellenkunde, mit einem Vorwort von B. Cotta, 1856.
[397] Études et Lectures, vi, p. 118.
[398] "The area of soil dried by draining is constantly increasing, and the
water received by the surface from atmospheric precipitation is thereby partly
conducted into new channels, and, in general, carried off more rapidly than
before. Will not this fact exert an influence on the condition of many springs,
whose basin of supply thus undergoes a partial or complete transformation? I am
convinced that it will, and it is important to collect data for solving the question."
Bernhard Cotta, Preface to Paramelle, Quellenkunde (German translation),
pp. vii, viii. See Appendix, No. 54.
[399] See the interesting observations of Kriegk on this subject, Schriften
zur allgemeinen Erdkunde, cap. iii, § 6, and especially the passages in Ritter's
Erdkunde, vol. i, there referred to.
Laurent, (Mémoires 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
Page 488
that the subterranean current thus reached appears to extend itself laterally, at
about the same level, at least a kilomètre from the river, as water is found by
digging to the depth of twelve or fifteen mètres at a village situated at that
distance from the bank.
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 freshened
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.
The precipitation in the mountains that border the Red Sea is not known by
pluviometric measurement, but the mass of debris brought down the ravines by
the torrents proves that their volume must be large. The proportion of surface
covered by sand and absorbent earth, in Arabia Petræa 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.
[400] It is conceivable that in large and shallow subterranean basins the
superincumbent earth may rest upon the water and be partly supported by it. In
such case the weight of the earth would be an additional, if not the sole, cause of
the ascent of the water through the tubes of artesian wells. The elasticity of gases
in the cavities may also aid in forcing up water.
A French engineer, M. Mullot, invented a simple method of bringing to the
surface water from any one of several successive accumulations at different
depths, or of raising it, unmixed, from two or more of them at once. It consists in
employing concentric tubes, one within the other, leaving a space for the rise of
water between them, and reaching each to the sheet from which it is intended to
draw.
[401] 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
Chaussées for July and August, 1839, p. 131, it was suggested that the sinking of
about the same level, at least a kilomètre from the river, as water is found by
digging to the depth of twelve or fifteen mètres at a village situated at that
distance from the bank.
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 freshened
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.
The precipitation in the mountains that border the Red Sea is not known by
pluviometric measurement, but the mass of debris brought down the ravines by
the torrents proves that their volume must be large. The proportion of surface
covered by sand and absorbent earth, in Arabia Petræa 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.
[400] It is conceivable that in large and shallow subterranean basins the
superincumbent earth may rest upon the water and be partly supported by it. In
such case the weight of the earth would be an additional, if not the sole, cause of
the ascent of the water through the tubes of artesian wells. The elasticity of gases
in the cavities may also aid in forcing up water.
A French engineer, M. Mullot, invented a simple method of bringing to the
surface water from any one of several successive accumulations at different
depths, or of raising it, unmixed, from two or more of them at once. It consists in
employing concentric tubes, one within the other, leaving a space for the rise of
water between them, and reaching each to the sheet from which it is intended to
draw.
[401] 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
Chaussées for July and August, 1839, p. 131, it was suggested that the sinking of
Page 489
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 Violett, Théorie des Puits Artésiens, 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 the flow
in a short time, and I do not know that any serious evil has ever been occasioned
in this way.
[402] 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, Mémoire sur le Sahara Oriental, etc., pp. 19, 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 alleges that he witnessed one 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 mètres deep.
It has often been asserted that the ancient Egyptians were acquainted with the
art of boring artesian wells. Parthey, describing the Little Oasis, mentions ruins
of a Roman aqueduct, and observes: "It appears from the recent researches of
Aim, a French engineer, that these aqueducts are connected with old artesian
wells, the restoration of which would render it practicable to extend cultivation
much beyond its present limits. This agrees with ancient testimony. It is asserted
that the inhabitants of the oases sunk wells to the depth of 200, 300, and even
500 ells, from which affluent streams of water poured out. See Olympiodorus in
Photii Bibl., cod. 80, p. 61, l. 17, ed. Bekk."—Parthey, Wanderungen, ii, p. 528.
In a paper entitled, Note relative à l'execution d'un Puits Artésien en Egypte
sous la XVIII dynastie, presented to the Académie des Inscriptions et Belles
Lettres, on the 12th of November, 1852, M. Lenormant endeavors to show that a
hieroglyphic inscription found at Contrapscelcis proves the execution of a work
of this sort in the Nubian desert, at the period indicated in the title to his paper.
The interpretation of the inscription is a question for Egyptologists; but if wells
were actually bored through the rock by the Egyptians after the Chinese or the
European fashion, it is singular that among the numerous and minute
representations of their industrial operations, painted or carved on the walls of
their tombs, no trace of the processes employed for so remarkable and important
a purpose should have been discovered. See Appendix, No. 56.
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 borer is
raised and let fall by a rope, instead of a rigid rod—has been 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—the deepest in Europe—is
2,300. A well was bored at St. Louis, in Missouri, a few years ago, to supply a
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 Violett, Théorie des Puits Artésiens, 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 the flow
in a short time, and I do not know that any serious evil has ever been occasioned
in this way.
[402] 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, Mémoire sur le Sahara Oriental, etc., pp. 19, 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 alleges that he witnessed one 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 mètres deep.
It has often been asserted that the ancient Egyptians were acquainted with the
art of boring artesian wells. Parthey, describing the Little Oasis, mentions ruins
of a Roman aqueduct, and observes: "It appears from the recent researches of
Aim, a French engineer, that these aqueducts are connected with old artesian
wells, the restoration of which would render it practicable to extend cultivation
much beyond its present limits. This agrees with ancient testimony. It is asserted
that the inhabitants of the oases sunk wells to the depth of 200, 300, and even
500 ells, from which affluent streams of water poured out. See Olympiodorus in
Photii Bibl., cod. 80, p. 61, l. 17, ed. Bekk."—Parthey, Wanderungen, ii, p. 528.
In a paper entitled, Note relative à l'execution d'un Puits Artésien en Egypte
sous la XVIII dynastie, presented to the Académie des Inscriptions et Belles
Lettres, on the 12th of November, 1852, M. Lenormant endeavors to show that a
hieroglyphic inscription found at Contrapscelcis proves the execution of a work
of this sort in the Nubian desert, at the period indicated in the title to his paper.
The interpretation of the inscription is a question for Egyptologists; but if wells
were actually bored through the rock by the Egyptians after the Chinese or the
European fashion, it is singular that among the numerous and minute
representations of their industrial operations, painted or carved on the walls of
their tombs, no trace of the processes employed for so remarkable and important
a purpose should have been discovered. See Appendix, No. 56.
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 borer is
raised and let fall by a rope, instead of a rigid rod—has been 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—the deepest in Europe—is
2,300. A well was bored at St. Louis, in Missouri, a few years ago, to supply a
Page 490
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. Another has since been bored at the
State capitol at Columbus, Ohio, 2,500 feet deep, but without obtaining the
desired supply of water.
[403] "In the anticipation of our success at Oum-Thiour, every thing 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, Aïssa ben Shâ, 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 succeeded to silence and desolation."—Laurent,
Mémoires sur le Sahara, p. 85.
[404] 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 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 Petræa 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
revolution.
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 islands 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 prominences.
three years, at the expense of only $10,000. Another has since been bored at the
State capitol at Columbus, Ohio, 2,500 feet deep, but without obtaining the
desired supply of water.
[403] "In the anticipation of our success at Oum-Thiour, every thing 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, Aïssa ben Shâ, 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 succeeded to silence and desolation."—Laurent,
Mémoires sur le Sahara, p. 85.
[404] 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 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 Petræa 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
revolution.
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 islands 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 prominences.
Page 491
[405] Œuvres de Palissy, Des Eaux et Fontaines, p. 157.
[406] Id., p. 166. See Appendix, No. 57.
[407] Babinet, Études 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.)
[408] M. G. Dumas, La Science des Fontaines, 1857.
[409] In the curiously variegated sandstone of Arabia Petræa—which is
certainly a reaggregation of loose sand derived from particles of older rocks—the
contiguous 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
by a succession of sudden aquatic or aerial currents flowing in different
directions and charged with differently colored matter.
[410] De Bodem van Nederland, i, pp. 243, 246-377, et seqq. See also the
arguments of Brémontier as to the origin of the dune sands of Gascony, Annales
des Ponts et Chaussées, 1833, 1er sémestre, pp. 158, 161. Brémontier estimates
the sand annually 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 mètres per running mètre, which is
equal to two hundred and sixty-eight cubic feet to the running foot.—Annales
des Ponts et Chaussées, 1842, 2me sémestre, 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 mètres, or more than 7,800,000 cubic yards.
[411] De Bodem van Nederland, i, p. 339.
[412] 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
[406] Id., p. 166. See Appendix, No. 57.
[407] Babinet, Études 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.)
[408] M. G. Dumas, La Science des Fontaines, 1857.
[409] In the curiously variegated sandstone of Arabia Petræa—which is
certainly a reaggregation of loose sand derived from particles of older rocks—the
contiguous 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
by a succession of sudden aquatic or aerial currents flowing in different
directions and charged with differently colored matter.
[410] De Bodem van Nederland, i, pp. 243, 246-377, et seqq. See also the
arguments of Brémontier as to the origin of the dune sands of Gascony, Annales
des Ponts et Chaussées, 1833, 1er sémestre, pp. 158, 161. Brémontier estimates
the sand annually 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 mètres per running mètre, which is
equal to two hundred and sixty-eight cubic feet to the running foot.—Annales
des Ponts et Chaussées, 1842, 2me sémestre, 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 mètres, or more than 7,800,000 cubic yards.
[411] De Bodem van Nederland, i, p. 339.
[412] 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
Page 492
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 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 Petræa, 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 angular 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 both 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 wormeaten before it was converted into silex.
[413] Böttger, Das Mittelmeer, p. 128.
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 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 Petræa, 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 angular 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 both 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 wormeaten before it was converted into silex.
[413] Böttger, Das Mittelmeer, p. 128.
Page 493
[414] 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 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 Brémontier 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. Sandbanks sometimes recede from the coast, instead of rolling
toward it. Reclus informs us that the Mauvaise, a sandbank 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, 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.
[415] 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. See ante, p. 453,
note.
[416] 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
conflicting, as might be expected from the infinite variety of conditions by which
the movement of 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 Brémontier 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. Sandbanks sometimes recede from the coast, instead of rolling
toward it. Reclus informs us that the Mauvaise, a sandbank 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, 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.
[415] 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. See ante, p. 453,
note.
[416] 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
Page 494
lifting them. Brémontier, 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."—Mémoire sur les Dunes, Annales des Ponts et Chaussées, 1833, 1er
sémestre, 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.
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 you may pick up, in such localities,
rounded, irregularly broken fragments of agate, which have 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 on the polishing of hard stones by drifting sand
will be found in the Geological Report of William P. Blake: Pacific Railroad
Report, vol. v, pp. 92, 230, 231. The same geologist observes, 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.
[417] 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.
[418] 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 westward, 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.
[419] "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
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."—Mémoire sur les Dunes, Annales des Ponts et Chaussées, 1833, 1er
sémestre, 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.
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 you may pick up, in such localities,
rounded, irregularly broken fragments of agate, which have 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 on the polishing of hard stones by drifting sand
will be found in the Geological Report of William P. Blake: Pacific Railroad
Report, vol. v, pp. 92, 230, 231. The same geologist observes, 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.
[417] 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.
[418] 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 westward, 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.
[419] "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
Page 495
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.
[420] 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."—Mémoires sur le Sahara, p. 14.
[421] Organic constituents, such as comminuted shells, and silicious and
calcareous exuviæ 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 sandbeds of
the Mark of Brandenburg, are still living and prolific in the dry earth. See
Wittwer, Physikalische Geographie, p. 142.
The desert on both sides of the Nile is inhabited by a land snail, 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
especially those of the oyster. They are due to the oyster eater [Hæmalopus
ostralegus], which carries his prey to the top of the dunes to devour it." See also
Staring, De Bodem van, N. I. p. 321.
[422] 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 toward 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 two hundred feet in height, and, in the Faroe Islands, on
precipices two thousand 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,
ocean with a progressive westward motion. The eastern half of the desert is
swept clean."—Naumann, Geognosie, ii, p. 1173.
[420] 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."—Mémoires sur le Sahara, p. 14.
[421] Organic constituents, such as comminuted shells, and silicious and
calcareous exuviæ 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 sandbeds of
the Mark of Brandenburg, are still living and prolific in the dry earth. See
Wittwer, Physikalische Geographie, p. 142.
The desert on both sides of the Nile is inhabited by a land snail, 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
especially those of the oyster. They are due to the oyster eater [Hæmalopus
ostralegus], which carries his prey to the top of the dunes to devour it." See also
Staring, De Bodem van, N. I. p. 321.
[422] 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 toward 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 two hundred feet in height, and, in the Faroe Islands, on
precipices two thousand 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,
Page 496
impinging against the vertical wall, creates an ascending current which shoots
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.
It is very commonly believed that it is impossible to grow forest trees on sea-
shore bluffs, or points much exposed to strong winds. The observations just cited
tend to show that it would not be difficult to protect trees from the mechanical
effect of the wind, by screens much lower than the height to which they are
expected to grow. Recent experiments confirm this, and it is found that, though
the outer row or rows may suffer from the wind, every tree shelters a taller one
behind it. Extensive groves have thus been formed in situations where an
isolated tree would not grow at all.
Piper, in his Trees of America, p. 19, 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 Nahant, 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."
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.
It is very commonly believed that it is impossible to grow forest trees on sea-
shore bluffs, or points much exposed to strong winds. The observations just cited
tend to show that it would not be difficult to protect trees from the mechanical
effect of the wind, by screens much lower than the height to which they are
expected to grow. Recent experiments confirm this, and it is found that, though
the outer row or rows may suffer from the wind, every tree shelters a taller one
behind it. Extensive groves have thus been formed in situations where an
isolated tree would not grow at all.
Piper, in his Trees of America, p. 19, 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 Nahant, 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."
Page 497
[423] 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.
[424] Staring, De Bodem van Nederland, i, p. 327, note.
[425] The principal special works and essays on this subject known to me
are:
Brémontier, Mémoire sur les Dunes, etc., 1790, reprinted in Annales des
Ponts et Chaussées, 1833, 1er sémestre, pp. 145-186.
Rapport sur les differents Mémoires de M. Brémontier, par Laumont et
autres, 1806, same volume, pp. 192, 224.
Lefort, Notice sur les Travaux de Fixation des Dunes, Annales des Ponts et
Chaussées, 1831, 2me sémestre, pp. 320-332.
Forchhammer, Geognostische Studien am Meeres Ufer, in Leonhard und
Bronn, Jahrbuch, etc., 1841, pp. 1, 38.
J. G. Kohl, Die Inseln und Marschen der Herzogthümer Schleswig und
Holstein, 1846, vol. ii, pp. 112-162, 193-204.
Laval, Mémoire sur les Dunes du Golfe de Gascogne, Annales des Ponts et
Chaussées, 1847, 2me sémestre, pp. 218-268.
G. C. A. Krause, Der Dünenbau auf den Ostsee-Küsten West-Preussens,
1850, 1 vol. 8vo.
W. C. H. Staring, De Bodem van Nederland, 1856, vol. i, pp. 310-341, and
424-431.
Same author, Voormaals en Thans, 1858, pages cited.
C. C. Andresen, Om Klitformationen og Klittens Behandling og Bestyrelse,
1861, 1 vol. 8vo, x, 392 pp., much the most complete treatise on the subject.
Andresen cites, upon the origin of the dunes: Hull, Over den Oorsprong en
de Geschiedenis der Hollandsche Duinen, 1838, and Gross's Veiledning ved
Behandlingen af Sandflugtstrækningerne, 1847; and upon the improvement of
sand plains by planting, Pannewitz, Anleitung zum Anbau der Sandflächen,
1832. I am not acquainted with either of the latter two works but I have
consulted with advantage, on this subject, Delamarre, Historique de la Création
d'une Richesse millionaire par la culture des Pins, 1827; Boitel, Mise en valeur
des terres pauvres par le Pin maritime, 1857; and Brincken, Ansichten über die
Bewaldung der Steppen des Europäischen Russlands, 1854.
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.
[424] Staring, De Bodem van Nederland, i, p. 327, note.
[425] The principal special works and essays on this subject known to me
are:
Brémontier, Mémoire sur les Dunes, etc., 1790, reprinted in Annales des
Ponts et Chaussées, 1833, 1er sémestre, pp. 145-186.
Rapport sur les differents Mémoires de M. Brémontier, par Laumont et
autres, 1806, same volume, pp. 192, 224.
Lefort, Notice sur les Travaux de Fixation des Dunes, Annales des Ponts et
Chaussées, 1831, 2me sémestre, pp. 320-332.
Forchhammer, Geognostische Studien am Meeres Ufer, in Leonhard und
Bronn, Jahrbuch, etc., 1841, pp. 1, 38.
J. G. Kohl, Die Inseln und Marschen der Herzogthümer Schleswig und
Holstein, 1846, vol. ii, pp. 112-162, 193-204.
Laval, Mémoire sur les Dunes du Golfe de Gascogne, Annales des Ponts et
Chaussées, 1847, 2me sémestre, pp. 218-268.
G. C. A. Krause, Der Dünenbau auf den Ostsee-Küsten West-Preussens,
1850, 1 vol. 8vo.
W. C. H. Staring, De Bodem van Nederland, 1856, vol. i, pp. 310-341, and
424-431.
Same author, Voormaals en Thans, 1858, pages cited.
C. C. Andresen, Om Klitformationen og Klittens Behandling og Bestyrelse,
1861, 1 vol. 8vo, x, 392 pp., much the most complete treatise on the subject.
Andresen cites, upon the origin of the dunes: Hull, Over den Oorsprong en
de Geschiedenis der Hollandsche Duinen, 1838, and Gross's Veiledning ved
Behandlingen af Sandflugtstrækningerne, 1847; and upon the improvement of
sand plains by planting, Pannewitz, Anleitung zum Anbau der Sandflächen,
1832. I am not acquainted with either of the latter two works but I have
consulted with advantage, on this subject, Delamarre, Historique de la Création
d'une Richesse millionaire par la culture des Pins, 1827; Boitel, Mise en valeur
des terres pauvres par le Pin maritime, 1857; and Brincken, Ansichten über die
Bewaldung der Steppen des Europäischen Russlands, 1854.
Page 498
[426] "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 und Bronn, 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 drift
sand was not moistened to a greater height than eight and a half inches, after
standing 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 is 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
mètres only, and the water rises to the height of a mètre in them.—Laurent,
Mémoire 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 that the proposal to fix the dunes which are supposed to threaten the Suez
Canal, by planting the maritime pine and other trees upon them, is not altogether
so absurd as it is thought to be by some of those disinterested philanthropists of
other nations who are distressed with fears that French capitalists will lose the
money they have invested in that great undertaking.
Ponds of water are often found in the depressions between the sand hills of
the dune chains in the North American desert.
[427] According to the French authorities, the dunes of France are not always
composed of quartzose sand. "The dune sands" of different characters, says
Brémontier, "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."—Mémoire sur les Dunes, Annales des Ponts et Chaussées, t. vii,
1833, 1er sémestre, 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.
[428] De Bodem van Nederland, i, p. 323.
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 und Bronn, 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 drift
sand was not moistened to a greater height than eight and a half inches, after
standing 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 is 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
mètres only, and the water rises to the height of a mètre in them.—Laurent,
Mémoire 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 that the proposal to fix the dunes which are supposed to threaten the Suez
Canal, by planting the maritime pine and other trees upon them, is not altogether
so absurd as it is thought to be by some of those disinterested philanthropists of
other nations who are distressed with fears that French capitalists will lose the
money they have invested in that great undertaking.
Ponds of water are often found in the depressions between the sand hills of
the dune chains in the North American desert.
[427] According to the French authorities, the dunes of France are not always
composed of quartzose sand. "The dune sands" of different characters, says
Brémontier, "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."—Mémoire sur les Dunes, Annales des Ponts et Chaussées, t. vii,
1833, 1er sémestre, 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.
[428] De Bodem van Nederland, i, p. 323.
Page 499
[429] J. G. Kohl, Die Inseln und Marschen der Herzogthümer Schleswig und
Holstein, ii, p. 200.
[430] Staring, De Bodem van Nederland, i, p. 317. See also, Bergsöe,
Reventov's Virksomhed, ii, p. 11.
"In the sand-hill ponds mentioned in the text, there is a vigorous 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 dunes is broken, the
sand blows into the ponds, covers the peat, and puts an end to its formation.
When, in the course of time, marine currents cut away the coast, the dunes move
landward and fill up the ponds, and thus are formed the remarkable strata of
fossile peat called Martörv, which appears to be unknown to the geologists of
other parts of Europe."—Forchhammer, in Leonhard und Bronn, 1841, p. 13.
[431] 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.
[432] "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 sea." See ante, p. 16, note.—Naumann, Geognosie, ii, p. 1172. See
Appendix, No. 58.
[433] 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. I find from Laurent (Mémoire sur
le Sahara, etc., p. 12), that in the Algerian desert there exist "sandstone
formations" 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 mètres 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." See Appendix, No. 59.
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.
Holstein, ii, p. 200.
[430] Staring, De Bodem van Nederland, i, p. 317. See also, Bergsöe,
Reventov's Virksomhed, ii, p. 11.
"In the sand-hill ponds mentioned in the text, there is a vigorous 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 dunes is broken, the
sand blows into the ponds, covers the peat, and puts an end to its formation.
When, in the course of time, marine currents cut away the coast, the dunes move
landward and fill up the ponds, and thus are formed the remarkable strata of
fossile peat called Martörv, which appears to be unknown to the geologists of
other parts of Europe."—Forchhammer, in Leonhard und Bronn, 1841, p. 13.
[431] 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.
[432] "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 sea." See ante, p. 16, note.—Naumann, Geognosie, ii, p. 1172. See
Appendix, No. 58.
[433] 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. I find from Laurent (Mémoire sur
le Sahara, etc., p. 12), that in the Algerian desert there exist "sandstone
formations" 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 mètres 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." See Appendix, No. 59.
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.
Page 500
[434] 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 former fluid; 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 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.
[435] 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.
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 dune sands 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 denote a difference of origin or of age.
[436] Laurent (Mémoire sur le Sahara, pp. 11, 12, and elsewhere) speaks of
a funnel-shaped depression at a high point in the dunes, as a characteristic
feature of the sand hills of the Algerian desert. This seems to be an
approximation to the crescent form noticed by Meyen and Pöppig in the inland
dunes of Peru.
[437] Travels in Peru, New York, 1848, chap. ix.
[438] Notwithstanding the general tendency of isolated coast dunes and of
the peaks of the sand ridges to assume a conical form, Andresen states that 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 former fluid; 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 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.
[435] 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.
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 dune sands 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 denote a difference of origin or of age.
[436] Laurent (Mémoire sur le Sahara, pp. 11, 12, and elsewhere) speaks of
a funnel-shaped depression at a high point in the dunes, as a characteristic
feature of the sand hills of the Algerian desert. This seems to be an
approximation to the crescent form noticed by Meyen and Pöppig in the inland
dunes of Peru.
[437] Travels in Peru, New York, 1848, chap. ix.
[438] Notwithstanding the general tendency of isolated coast dunes and of
the peaks of the sand ridges to assume a conical form, Andresen states that the
Page 501
hills of the inner or landward rows are sometimes bow-shaped, and sometimes
undulating in outline.—Om Klitformationen, p. 84. He says further that: "Before
an obstruction, two or three feet high and considerably longer, lying
perpendicularly to the direction of the wind, the sand is deposited with a
windward angle of from 6° to 12°, and the bank presents a concave face to the
wind, while, behind the obstruction, the outline is convex;" and he lays it down
as a general rule, that a slope, from which sand is blown, is left with a concavity
of about one inch of depth to four feet of distance; a slope, upon which sand is
dropped by the wind, is convex. It appears from Andresen's figures, however,
that the concavity and convexity referred to, apply, not to the horizontal
longitudinal section of the sand bank, as his language unexplained by the
drawings might be supposed to mean, but to the vertical cross-section, and hence
the dunes he describes, with the exception above noted, do not correspond to
those of the American deserts.—Om Klitformationen, p. 86.
The dunes of Gascony, which sometimes exceed three hundred feet in height,
present the same concavity and convexity of vertical cross-section. The slopes of
these dunes are much steeper than those of the Netherlands and the Danish coast;
for while all observers agree in assigning to the seaward and landward faces of
those latter, respectively, angles of from 5° to 12°, and 30° with the horizon, the
corresponding faces of the dunes of Gascony present angles of from 10° to 25°,
and 50° to 60°.—Laval, Mémoire sur les Dunes de Gascogne, Annales des Ponts
et Chaussées, 1847, 2me sémestre.
[439] 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 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 Dünenbau, pp. 8, 11.
[440] Laval, Mémoire sur les Dunes de Gascogne, Annales des Ponts et
Chaussées, 1847, 2me sémestre, p. 231. The same opinion had been expressed
by Brémontier, Annales des Ponts et Chaussées, 1833, 1er sémestre, p. 185.
[441] "In the Middle Ages," says Willibald Alexis, as quoted by Müller, Das
Buch der Pflanzenwelt i, p. 16, "the Nehrung 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
undulating in outline.—Om Klitformationen, p. 84. He says further that: "Before
an obstruction, two or three feet high and considerably longer, lying
perpendicularly to the direction of the wind, the sand is deposited with a
windward angle of from 6° to 12°, and the bank presents a concave face to the
wind, while, behind the obstruction, the outline is convex;" and he lays it down
as a general rule, that a slope, from which sand is blown, is left with a concavity
of about one inch of depth to four feet of distance; a slope, upon which sand is
dropped by the wind, is convex. It appears from Andresen's figures, however,
that the concavity and convexity referred to, apply, not to the horizontal
longitudinal section of the sand bank, as his language unexplained by the
drawings might be supposed to mean, but to the vertical cross-section, and hence
the dunes he describes, with the exception above noted, do not correspond to
those of the American deserts.—Om Klitformationen, p. 86.
The dunes of Gascony, which sometimes exceed three hundred feet in height,
present the same concavity and convexity of vertical cross-section. The slopes of
these dunes are much steeper than those of the Netherlands and the Danish coast;
for while all observers agree in assigning to the seaward and landward faces of
those latter, respectively, angles of from 5° to 12°, and 30° with the horizon, the
corresponding faces of the dunes of Gascony present angles of from 10° to 25°,
and 50° to 60°.—Laval, Mémoire sur les Dunes de Gascogne, Annales des Ponts
et Chaussées, 1847, 2me sémestre.
[439] 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 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 Dünenbau, pp. 8, 11.
[440] Laval, Mémoire sur les Dunes de Gascogne, Annales des Ponts et
Chaussées, 1847, 2me sémestre, p. 231. The same opinion had been expressed
by Brémontier, Annales des Ponts et Chaussées, 1833, 1er sémestre, p. 185.
[441] "In the Middle Ages," says Willibald Alexis, as quoted by Müller, Das
Buch der Pflanzenwelt i, p. 16, "the Nehrung 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
Page 502
allowed to remove something quite useless. He thinned out the forests of Prussia,
which then, indeed, possessed little pecuniary value; but he felled the entire
woods of the Frische Nehrung, so far as they lay within the Prussian territory.
The financial operation was a success. The king had money, but in the
elementary operation 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 Königsberg 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."
[442] 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 Cæsar, Ptolemy, and the encyclopædic Pliny, respecting them, would
be not less inexplicable.
The Old Northern language, the ancient tongue of Denmark, though rich in
terms descriptive of natural scenery, had no name for dune, nor do I think the
sand hills of the coast are anywhere noticed in Icelandic literature. The modern
Icelanders, in treating of the dunes of Jutland, call them klettr, hill, cliff, and the
Danish klit is from that source. The word Düne is also of recent introduction into
German. Had the dunes been distinguished from other hillocks, in ancient times,
by so remarkable a feature as the propensity to drift, they would certainly have
acquired a specific name in both Old Northern and German. So long as they
were wooded knolls, they needed no peculiar name; when they became
formidable, from the destruction of the woods which confined them, they
acquired a designation.
[443] 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 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.
[444] Bergsöe (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.
which then, indeed, possessed little pecuniary value; but he felled the entire
woods of the Frische Nehrung, so far as they lay within the Prussian territory.
The financial operation was a success. The king had money, but in the
elementary operation 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 Königsberg 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."
[442] 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 Cæsar, Ptolemy, and the encyclopædic Pliny, respecting them, would
be not less inexplicable.
The Old Northern language, the ancient tongue of Denmark, though rich in
terms descriptive of natural scenery, had no name for dune, nor do I think the
sand hills of the coast are anywhere noticed in Icelandic literature. The modern
Icelanders, in treating of the dunes of Jutland, call them klettr, hill, cliff, and the
Danish klit is from that source. The word Düne is also of recent introduction into
German. Had the dunes been distinguished from other hillocks, in ancient times,
by so remarkable a feature as the propensity to drift, they would certainly have
acquired a specific name in both Old Northern and German. So long as they
were wooded knolls, they needed no peculiar name; when they became
formidable, from the destruction of the woods which confined them, they
acquired a designation.
[443] 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 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.
[444] Bergsöe (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.
Page 503
[445] "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, the peninsula of
Eiderstädt in the south of Friesland, has, on the point toward 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.
[446] 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.
[447] Andresen, Om Klitformationen, pp. 68-72.
[448] 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."
[449] Forchhammer, Geognostische Studien am Meeres-Ufer. Leonhard
und Bronn, Jahrbuch, 1841, pp. 11, 13.
[450] Andresen, Om Klitformationen, pp. 68, 72.
[451] Voormaals en Thans, pp. 126, 170.
[452] See a very interesting article entitled "Le Littoral de la France," by
Élisée Reclus, in the Revue des Deux Mondes, for December, 1862, pp. 901,
936.
[453] De Bodem van Nederland, i, p. 425. See Appendix, No. 60.
[454] The movement of the dunes has been hardly less destructive on the
north side of the Gironde. Sea the valuable article of Élisée Reclus already
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, the peninsula of
Eiderstädt in the south of Friesland, has, on the point toward 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.
[446] 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.
[447] Andresen, Om Klitformationen, pp. 68-72.
[448] 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."
[449] Forchhammer, Geognostische Studien am Meeres-Ufer. Leonhard
und Bronn, Jahrbuch, 1841, pp. 11, 13.
[450] Andresen, Om Klitformationen, pp. 68, 72.
[451] Voormaals en Thans, pp. 126, 170.
[452] See a very interesting article entitled "Le Littoral de la France," by
Élisée Reclus, in the Revue des Deux Mondes, for December, 1862, pp. 901,
936.
[453] De Bodem van Nederland, i, p. 425. See Appendix, No. 60.
[454] The movement of the dunes has been hardly less destructive on the
north side of the Gironde. Sea the valuable article of Élisée Reclus already
Page 504
referred to, in the Revue des Deux Mondes, for December, 1862, entitled "Le
Littoral de la France."
[455] Laval, Mémoire sur les Dunes du Golfe de Gascogne, Annales des
Ponts et Chaussées, 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 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 northeast 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? See Appendix, No. 61.
[456] Andresen, Om Klitformationem, pp. 56, 79, 82.
[457] 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."—Dwight's Travels,
iii, p. 93.
[458] Staring, i, pp. 310, 332.
[459] 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.
[460] 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.
[461] Bergsöe, Reventlovs Virksomhed, ii, p. 4.
Littoral de la France."
[455] Laval, Mémoire sur les Dunes du Golfe de Gascogne, Annales des
Ponts et Chaussées, 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 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 northeast 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? See Appendix, No. 61.
[456] Andresen, Om Klitformationem, pp. 56, 79, 82.
[457] 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."—Dwight's Travels,
iii, p. 93.
[458] Staring, i, pp. 310, 332.
[459] 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.
[460] 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.
[461] Bergsöe, Reventlovs Virksomhed, ii, p. 4.
Page 505
[462] Measures were taken for the protection of the dunes of Cape Cod, in
Massachusetts, 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 Pilgrims, therefore, abandons the sand hills,
and seeks a better fortune on the fertile prairies of the West.
Dr. Dwight, who visited Cape Cod in the year 1800, after describing the
"beach grass, a vegetable bearing a general resemblance to sedge, but of a light
bluish-green, and of a coarse appearance," which "flourishes with a strong and
rapid vegetation on the sands," observes that he received "from a Mr. Collins,
formerly of Truro, the following information:" "When he lived at Truro, the
inhabitants were, under the authority of law, regularly warned in the month of
April, yearly, to plant beach grass, as, in other towns of New England, they are
warned to repair highways. It was required by the laws of the State, and under
the proper penalties for disobedience; being as regular a public tax as any other.
The people, therefore, generally attended and performed the labor. The grass was
dug in bunches, as it naturally grows; and each bunch divided into a number of
smaller ones. These were set out in the sand at distances of three feet. After one
row was set, others were placed behind it in such a manner as to shut up the
interstices; or, as a carpenter would say, so as to break the joints. * * * When it is
once set, it grows and spreads with rapidity. * * * The seeds are so heavy that
they bend down the heads of the grass; and when ripe, drop directly down by its
side, where they immediately vegetate. Thus in a short time the ground is
covered.
"Where this covering is found, none of the sand is blown. On the contrary, it
is accumulated and raised continually as snow gathers and rises among bushes,
or branches of trees cut and spread upon the earth. Nor does the grass merely
defend the surface on which it is planted; but rises, as that rises by new
accumulations; and always overtops the sand, however high that may be raised
by the wind."—Dwight's Travels in New England and New York, ii, p. 92, 93.
This information was received in 1800, and it relates to a former state of
things, probably more than twenty years previous, and earlier than 1779, when
the Government of Denmark first seriously attempted the conquest of the dunes.
The depasturing of the beach grass—a plant allied in habits, if not in
botanical character, to the arundo—has been attended with very injurious effects
in Massachusetts. Dr. Dwight, after referring to the laws for its propagation,
already cited, says: "The benefit of this useful plant, and of these prudent
regulations, is, however, in some measure lost. There are in Province Town, as I
was informed, one hundred and forty cows. These animals, being stinted in their
means of subsistence, are permitted to wander, at times, in search of food. In
every such case, they make depredations on the beach grass, and prevent its
seeds from being formed. In this manner the plant is ultimately destroyed."—
Travels, iii, p. 94.
Massachusetts, 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 Pilgrims, therefore, abandons the sand hills,
and seeks a better fortune on the fertile prairies of the West.
Dr. Dwight, who visited Cape Cod in the year 1800, after describing the
"beach grass, a vegetable bearing a general resemblance to sedge, but of a light
bluish-green, and of a coarse appearance," which "flourishes with a strong and
rapid vegetation on the sands," observes that he received "from a Mr. Collins,
formerly of Truro, the following information:" "When he lived at Truro, the
inhabitants were, under the authority of law, regularly warned in the month of
April, yearly, to plant beach grass, as, in other towns of New England, they are
warned to repair highways. It was required by the laws of the State, and under
the proper penalties for disobedience; being as regular a public tax as any other.
The people, therefore, generally attended and performed the labor. The grass was
dug in bunches, as it naturally grows; and each bunch divided into a number of
smaller ones. These were set out in the sand at distances of three feet. After one
row was set, others were placed behind it in such a manner as to shut up the
interstices; or, as a carpenter would say, so as to break the joints. * * * When it is
once set, it grows and spreads with rapidity. * * * The seeds are so heavy that
they bend down the heads of the grass; and when ripe, drop directly down by its
side, where they immediately vegetate. Thus in a short time the ground is
covered.
"Where this covering is found, none of the sand is blown. On the contrary, it
is accumulated and raised continually as snow gathers and rises among bushes,
or branches of trees cut and spread upon the earth. Nor does the grass merely
defend the surface on which it is planted; but rises, as that rises by new
accumulations; and always overtops the sand, however high that may be raised
by the wind."—Dwight's Travels in New England and New York, ii, p. 92, 93.
This information was received in 1800, and it relates to a former state of
things, probably more than twenty years previous, and earlier than 1779, when
the Government of Denmark first seriously attempted the conquest of the dunes.
The depasturing of the beach grass—a plant allied in habits, if not in
botanical character, to the arundo—has been attended with very injurious effects
in Massachusetts. Dr. Dwight, after referring to the laws for its propagation,
already cited, says: "The benefit of this useful plant, and of these prudent
regulations, is, however, in some measure lost. There are in Province Town, as I
was informed, one hundred and forty cows. These animals, being stinted in their
means of subsistence, are permitted to wander, at times, in search of food. In
every such case, they make depredations on the beach grass, and prevent its
seeds from being formed. In this manner the plant is ultimately destroyed."—
Travels, iii, p. 94.
Page 506
On page 101 of the same volume, the author mentions an instance of great
injury from this cause. "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."
[463] Andresen, Om Klitformationen, pp. 237, 240.
[464] "These plantations, perseveringly continued from the time of
Brémontier now cover more than 40,000 hectares, and compose forests which
are not only the salvation of the department, but constitute its wealth."—Clavé,
Études Forestières, p. 254.
Other authors have stated the plantations of the French dunes to be much
more extensive.
[465] Kruse, Dünenbau, pp. 34, 38, 40.
[466] 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. See Appendix, No. 62.
[467] Andresen, Om Klitformationen, pp. 78, 262, 275.
[468] Laval, Mémoire sur les Dunes du Golfe de Gascogne, Annales des
Ponts et Chaussées, 1847, 2me sémestre, p. 261. See Appendix, No. 63.
[469] There are extensive ranges of dunes on various parts of the coasts of
the British Islands, but I find no estimate of their area. Pannewitz (Anleitung zam
Anbau der Sandflächen), as cited by Andresen (Om Klitformationen, p. 45),
states that the drifting sands of Europe, including, of course, sand plains as well
injury from this cause. "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."
[463] Andresen, Om Klitformationen, pp. 237, 240.
[464] "These plantations, perseveringly continued from the time of
Brémontier now cover more than 40,000 hectares, and compose forests which
are not only the salvation of the department, but constitute its wealth."—Clavé,
Études Forestières, p. 254.
Other authors have stated the plantations of the French dunes to be much
more extensive.
[465] Kruse, Dünenbau, pp. 34, 38, 40.
[466] 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. See Appendix, No. 62.
[467] Andresen, Om Klitformationen, pp. 78, 262, 275.
[468] Laval, Mémoire sur les Dunes du Golfe de Gascogne, Annales des
Ponts et Chaussées, 1847, 2me sémestre, p. 261. See Appendix, No. 63.
[469] There are extensive ranges of dunes on various parts of the coasts of
the British Islands, but I find no estimate of their area. Pannewitz (Anleitung zam
Anbau der Sandflächen), as cited by Andresen (Om Klitformationen, p. 45),
states that the drifting sands of Europe, including, of course, sand plains as well
Page 507
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.
[470] Boitel, Mise en valeur des Terres pauvres par le Pin maritime, pp.
212, 218.
[471] See Appendix, No. .
[472] For details, consult Andresen, Om Klitformationen, pp. 223, 236.
[473] 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.
[474] Travels and Researches in Chaldæa, chap. ix.
[475] Études Forestières, p. 253.
[476] Lavergne, Économie 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. 304), 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
agriculture 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. See Appendix, No. 64.
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.
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.
[470] Boitel, Mise en valeur des Terres pauvres par le Pin maritime, pp.
212, 218.
[471] See Appendix, No. .
[472] For details, consult Andresen, Om Klitformationen, pp. 223, 236.
[473] 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.
[474] Travels and Researches in Chaldæa, chap. ix.
[475] Études Forestières, p. 253.
[476] Lavergne, Économie 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. 304), 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
agriculture 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. See Appendix, No. 64.
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.
Page 508
[477] Économie Rurale de la Belgique, par Emile de Laveleye, Revue des
Deux Mondes, Juin, 1861, pp. 617-644.
[478] Geognosie, ii, p. 1173.
[479] 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.
[480] "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 of sixteen years this rapidly growing tree had formed
real forests. Other landowners have imitated his example with great advantage.
—Rentsch, Der Wald, p. 44, 45.
[481] Souvenirs d'un Naturaliste, i, pp. 204 et seqq.
[482] "If we suppose the narrow isthmus of Central America to be sunk in the
ocean, the warm equatorial current would no longer follow its circuitous route
around the Gulf of Mexico, but pour itself through the new opening directly into
the Pacific. We should then lose the warmth of the Gulf Stream, and cold polar
currents flowing farther southward would take its place and be driven upon our
coasts by the western winds. The North Sea would resemble Hudson's Bay, and
its harbors be free from ice at best only in summer. The power and prosperity of
its coasts would shrivel under the breath of winter, as a medusa thrown on shore
shrinks to an insignificant film under the influence of the destructive atmosphere.
Commerce, industry, fertility of soil, population, would disappear, and the vast
waste—a new Labrador—would become a worthless appendage of some clime
more favored by nature."—Hartwig, Das Leben des Meeres, p. 70.
[483] I know nothing of Captain Allen's work but its title and its subject.
Very probably he may have anticipated many of the following speculations, and
thrown light on points upon which I am ignorant.
[484] "Some haue writtē, 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 frō 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,
Deux Mondes, Juin, 1861, pp. 617-644.
[478] Geognosie, ii, p. 1173.
[479] 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.
[480] "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 of sixteen years this rapidly growing tree had formed
real forests. Other landowners have imitated his example with great advantage.
—Rentsch, Der Wald, p. 44, 45.
[481] Souvenirs d'un Naturaliste, i, pp. 204 et seqq.
[482] "If we suppose the narrow isthmus of Central America to be sunk in the
ocean, the warm equatorial current would no longer follow its circuitous route
around the Gulf of Mexico, but pour itself through the new opening directly into
the Pacific. We should then lose the warmth of the Gulf Stream, and cold polar
currents flowing farther southward would take its place and be driven upon our
coasts by the western winds. The North Sea would resemble Hudson's Bay, and
its harbors be free from ice at best only in summer. The power and prosperity of
its coasts would shrivel under the breath of winter, as a medusa thrown on shore
shrinks to an insignificant film under the influence of the destructive atmosphere.
Commerce, industry, fertility of soil, population, would disappear, and the vast
waste—a new Labrador—would become a worthless appendage of some clime
more favored by nature."—Hartwig, Das Leben des Meeres, p. 70.
[483] I know nothing of Captain Allen's work but its title and its subject.
Very probably he may have anticipated many of the following speculations, and
thrown light on points upon which I am ignorant.
[484] "Some haue writtē, 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 frō 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,
Page 509
which (they say) he may, or impouerish it at the least."—George Sandys, A
Relation of a Journey, etc., p. 98.
[485] The Recca, a river with a considerable current, 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
distance from Trieste to a suitable point in the grotto of Trebich is thought to be
less than three miles, and the difficulties in the way of constructing a tunnel do
not seem formidable. The works of Schmidl, Die Höhlen des Karstes, and Der
unterirdische Lauf der Recca, are not common out of Germany, but the reader
will find many interesting facts derived from them in two articles entitled Der
unterirdische Lauf der Recca, in Aus der Natur, xx, pp. 250-254, 263-266.
[486] Barth, Wanderungen durch die Küsten des Mittelmeeres, i, p. 353. In a
note on page 380, of the same volume, Barth cites Strabo as asserting that a
similar practice prevailed in Iapygia; but it may be questioned whether the
epithet τραχεῖα, applied by Strabo to the original surface, necessarily implies that
it was covered with a continuous stratum of rock.
[487] Parthey, Wanderungen durch Sicilien und die Levante, i, p. 404.
[488] Geognostische Studien am Meeres Ufer, Leonhard und Bronn,
Jahrbuch, 1841, pp. 25, 26.
[489] Kohl, Schleswig-Holstein, ii, p. 45.
[490] Wanderungen durch Sicilien und die Levante, i, p. 406.
[491] Landgrebe, Naturgeschichte der Vulkane, ii, pp. 19, 20.
[492] Soon after the current issues from the volcano, it is covered above and
at its sides, and finally in front, with scoriæ, 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 scoriæ, 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 begins 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 upward with
great velocity, like the water from a spring, in a stream eight or ten feet in
Relation of a Journey, etc., p. 98.
[485] The Recca, a river with a considerable current, 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
distance from Trieste to a suitable point in the grotto of Trebich is thought to be
less than three miles, and the difficulties in the way of constructing a tunnel do
not seem formidable. The works of Schmidl, Die Höhlen des Karstes, and Der
unterirdische Lauf der Recca, are not common out of Germany, but the reader
will find many interesting facts derived from them in two articles entitled Der
unterirdische Lauf der Recca, in Aus der Natur, xx, pp. 250-254, 263-266.
[486] Barth, Wanderungen durch die Küsten des Mittelmeeres, i, p. 353. In a
note on page 380, of the same volume, Barth cites Strabo as asserting that a
similar practice prevailed in Iapygia; but it may be questioned whether the
epithet τραχεῖα, applied by Strabo to the original surface, necessarily implies that
it was covered with a continuous stratum of rock.
[487] Parthey, Wanderungen durch Sicilien und die Levante, i, p. 404.
[488] Geognostische Studien am Meeres Ufer, Leonhard und Bronn,
Jahrbuch, 1841, pp. 25, 26.
[489] Kohl, Schleswig-Holstein, ii, p. 45.
[490] Wanderungen durch Sicilien und die Levante, i, p. 406.
[491] Landgrebe, Naturgeschichte der Vulkane, ii, pp. 19, 20.
[492] Soon after the current issues from the volcano, it is covered above and
at its sides, and finally in front, with scoriæ, 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 scoriæ, 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 begins 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 upward with
great velocity, like the water from a spring, in a stream eight or ten feet in
Page 510
diameter, throwing up occasionally volcanic bombs, 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 scoriæ 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 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. § 6.
[493] Ferrara, Descrizione dell' Etna, p. 108.
[494] Langrebe, Naturgeschichte der Vulkane, ii, p. 82.
[495] Physikalische Geographie, p. 168. Beds of peat, accidentally set on
fire, sometimes continue to burn for months. I take the following account of a
case of this sort from a recent American journal:
"A Curious Phenomenon.—When the track of the railroad between
Brunswick and Bath was being graded, in crossing a meadow near the populous
portion of the latter city, the 'dump' suddenly took on a sinking symptom, and
down went the twenty feet fill of gravel, clay, and broken rocks, out of sight, and
it was a long, long time before dirt trains could fill the capacious stomach that
seemed ready to receive all the solid material that could be turned into it. The
difficulty was at length overcome, but all along the side of the sinkage the earth
was thrown up, broken into yawning chasms, and the surface was thus elevated
above its old watery level. Since that time this ground, thus slightly elevated, has
been cultivated, and has yielded enormously of whatever the owner seemed
disposed to plant upon it. Some three months ago, by some means unknown to
us, the underlying peat took fire, and for weeks, as we had occasion to pass it, we
noticed the smoke arising from the smouldering combustion beneath the surface.
Rains fell, but the fire burned, and the smoke continued to arise. Monday we had
occasion to pass the spot, and though nearly a week's rain had been drenching
the ground, and though the surface was whitened with snow, and though pools of
water were standing upon the surface in the immediate neighborhood, still the
everlasting subterranean fire was burning, and the smoke arising through the
snow."
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 scoriæ 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 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. § 6.
[493] Ferrara, Descrizione dell' Etna, p. 108.
[494] Langrebe, Naturgeschichte der Vulkane, ii, p. 82.
[495] Physikalische Geographie, p. 168. Beds of peat, accidentally set on
fire, sometimes continue to burn for months. I take the following account of a
case of this sort from a recent American journal:
"A Curious Phenomenon.—When the track of the railroad between
Brunswick and Bath was being graded, in crossing a meadow near the populous
portion of the latter city, the 'dump' suddenly took on a sinking symptom, and
down went the twenty feet fill of gravel, clay, and broken rocks, out of sight, and
it was a long, long time before dirt trains could fill the capacious stomach that
seemed ready to receive all the solid material that could be turned into it. The
difficulty was at length overcome, but all along the side of the sinkage the earth
was thrown up, broken into yawning chasms, and the surface was thus elevated
above its old watery level. Since that time this ground, thus slightly elevated, has
been cultivated, and has yielded enormously of whatever the owner seemed
disposed to plant upon it. Some three months ago, by some means unknown to
us, the underlying peat took fire, and for weeks, as we had occasion to pass it, we
noticed the smoke arising from the smouldering combustion beneath the surface.
Rains fell, but the fire burned, and the smoke continued to arise. Monday we had
occasion to pass the spot, and though nearly a week's rain had been drenching
the ground, and though the surface was whitened with snow, and though pools of
water were standing upon the surface in the immediate neighborhood, still the
everlasting subterranean fire was burning, and the smoke arising through the
snow."
Page 511
[496] 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 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
material 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 cognizance.
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 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
material 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 cognizance.
Page 512
APPENDIX.
No. 1 (page 19, note). It may be said that the cases referred to in the
note on p. 19—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.
No. 2 (page 24, note). The adjectives of direction in -erly are not
unfrequently used to indicate, in a loose way, the course of winds blowing
from unspecified points between N.E. and S.E.; S.E. and S.W.; S.W. and
N.W. or N.W. and N.E. If the employment of these words were understood
to be limited to thus expressing a direction nearer to the cardinal point from
whose name the adjective is taken than to any other cardinal point, they
would be valuable elements of English meteorological nomenclature.
No. 3 (page 31). I find a confirmation of my observations on the habits
of the beaver as a geographical agency, in a report of the proceedings of the
British Association, in the London Athenæum of October 8, 1864, p. 469. It
is there stated that Viscount Milton and Dr. Cheadle, in an expedition across
the Rocky Mountains by the Yellow Head, or Leather Pass, observed that "a
great portion of the country to the east of the mountains" had been
"completely changed in character by the agency of the beaver, which
formerly existed here in enormous numbers. The shallow valleys were
formerly traversed by rivers and chains of lakes which, dammed up along
their course at numerous points, by the work of those animals, have become
a series of marshes in various stages of consolidation. So complete has this
change been, that hardly a stream is found for a distance of two hundred
miles, with the exception of the large rivers. The animals have thus
No. 1 (page 19, note). It may be said that the cases referred to in the
note on p. 19—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.
No. 2 (page 24, note). The adjectives of direction in -erly are not
unfrequently used to indicate, in a loose way, the course of winds blowing
from unspecified points between N.E. and S.E.; S.E. and S.W.; S.W. and
N.W. or N.W. and N.E. If the employment of these words were understood
to be limited to thus expressing a direction nearer to the cardinal point from
whose name the adjective is taken than to any other cardinal point, they
would be valuable elements of English meteorological nomenclature.
No. 3 (page 31). I find a confirmation of my observations on the habits
of the beaver as a geographical agency, in a report of the proceedings of the
British Association, in the London Athenæum of October 8, 1864, p. 469. It
is there stated that Viscount Milton and Dr. Cheadle, in an expedition across
the Rocky Mountains by the Yellow Head, or Leather Pass, observed that "a
great portion of the country to the east of the mountains" had been
"completely changed in character by the agency of the beaver, which
formerly existed here in enormous numbers. The shallow valleys were
formerly traversed by rivers and chains of lakes which, dammed up along
their course at numerous points, by the work of those animals, have become
a series of marshes in various stages of consolidation. So complete has this
change been, that hardly a stream is found for a distance of two hundred
miles, with the exception of the large rivers. The animals have thus
Page 513
destroyed, by their own labors, the waters necessary to their own
existence."
When the process of "consolidation" shall have been completed, and the
forest reëstablished 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.
No. 4 (page 33, note). 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 Société Entomologique de la
France, for 1851 (?), 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 not speaking of those
which confine their voracity to the leaf—do not attack trees in sound health,
and they assail those only whose normal conditions and functions have been
by some cause impaired."
See, more fully, Samanos, Traité de la Culture du Pin Maritime, Paris,
1864, pp. 140-145.
No. 5 (page 34, note). 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 their shells and carefully stored in a dry cavity.
No. 6 (page 40, note). Schroeder van der Kolk, in Het Verschil tusschen
den Psychischen Aanleg van het Dier en van den Mensch, cites from
existence."
When the process of "consolidation" shall have been completed, and the
forest reëstablished 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.
No. 4 (page 33, note). 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 Société Entomologique de la
France, for 1851 (?), 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 not speaking of those
which confine their voracity to the leaf—do not attack trees in sound health,
and they assail those only whose normal conditions and functions have been
by some cause impaired."
See, more fully, Samanos, Traité de la Culture du Pin Maritime, Paris,
1864, pp. 140-145.
No. 5 (page 34, note). 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 their shells and carefully stored in a dry cavity.
No. 6 (page 40, note). Schroeder van der Kolk, in Het Verschil tusschen
den Psychischen Aanleg van het Dier en van den Mensch, cites from
Page 514
Burdach and other authorities 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.
Perhaps the half-wild character ascribed by P. Læstadius 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 buffaloes
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 have not yet been reclaimed from it.
Among other instances of obliterated instincts, Schroeder van der Kolk
states that in Holland, where, for centuries, the young of the cow has been
usually taken 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.
No. 7 (page 60, first note). At Piè di Mulera, at the outlet of the Val
Anzasca, near the principal hotel, is a vine measuring thirty-one inches in
circumference. The door of the chapter-hall in the cloister of the church of
San Giovanni, at Saluzzo, is of vine wood, and the boards of which the
panels were made could not have been less than ten inches wide. Statues
and other objects of considerable dimensions, of vine wood, are mentioned
by ancient writers.
No. 8 (page 63, second note). Cartier, A. D. 1535-'6, mentions "vines,
great melons, cucumbers, gourds [courges], pease, beans of various colors,
but not like ours," as common 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.
No. 8 (page 65, second paragraph). 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
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.
Perhaps the half-wild character ascribed by P. Læstadius 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 buffaloes
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 have not yet been reclaimed from it.
Among other instances of obliterated instincts, Schroeder van der Kolk
states that in Holland, where, for centuries, the young of the cow has been
usually taken 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.
No. 7 (page 60, first note). At Piè di Mulera, at the outlet of the Val
Anzasca, near the principal hotel, is a vine measuring thirty-one inches in
circumference. The door of the chapter-hall in the cloister of the church of
San Giovanni, at Saluzzo, is of vine wood, and the boards of which the
panels were made could not have been less than ten inches wide. Statues
and other objects of considerable dimensions, of vine wood, are mentioned
by ancient writers.
No. 8 (page 63, second note). Cartier, A. D. 1535-'6, mentions "vines,
great melons, cucumbers, gourds [courges], pease, beans of various colors,
but not like ours," as common 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.
No. 8 (page 65, second paragraph). 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
Page 515
botanist, in an hour's visit to Aden, discovered several species of plants on
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.
No. 9 (page 66, first note). Although the vine genus is very catholic and
cosmopolite in its habits, yet 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.
No. 10 (page 68, first note). In most of the countries of Southern
Europe, sheep and beeves are wintered upon the plains, but driven in the
summer to mountain pastures at many days' distance from the homesteads
of their owners. They transport seeds in their coats in both directions, and
hence Alpine plants often shoot up at the foot of the mountains, the grasses
of the plain on the borders of the glaciers; but in both cases, they usually
fail to propagate themselves by ripening their seed. This explains the
scattered tufts of common clover, with pale and flaccid blossoms, which are
sometimes seen at heights exceeding 7,000 feet above the sea.
No. 11 (page 73, last paragraph). The poisonous wild parsnip, which is
very common in New England, is popularly believed to be identical with
the garden parsnip, and differenced only by conditions of growth, a richer
soil depriving it, it is said, of its noxious properties. Many wild medicinal
plants, such as pennyroyal for example, are so much less aromatic and
powerful, when cultivated in gardens, than when self-sown on meagre soils,
as to be hardly fit for use.
No. 12 (page 74, second note). See in Thoreau's Excursions, an
interesting description of the wild apple-trees of Massachusetts.
No. 13 (page 86, first paragraph). It is said at Courmayeur that a very
few ibexes of a larger variety than those of the Cogne mountains, still linger
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.
No. 9 (page 66, first note). Although the vine genus is very catholic and
cosmopolite in its habits, yet 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.
No. 10 (page 68, first note). In most of the countries of Southern
Europe, sheep and beeves are wintered upon the plains, but driven in the
summer to mountain pastures at many days' distance from the homesteads
of their owners. They transport seeds in their coats in both directions, and
hence Alpine plants often shoot up at the foot of the mountains, the grasses
of the plain on the borders of the glaciers; but in both cases, they usually
fail to propagate themselves by ripening their seed. This explains the
scattered tufts of common clover, with pale and flaccid blossoms, which are
sometimes seen at heights exceeding 7,000 feet above the sea.
No. 11 (page 73, last paragraph). The poisonous wild parsnip, which is
very common in New England, is popularly believed to be identical with
the garden parsnip, and differenced only by conditions of growth, a richer
soil depriving it, it is said, of its noxious properties. Many wild medicinal
plants, such as pennyroyal for example, are so much less aromatic and
powerful, when cultivated in gardens, than when self-sown on meagre soils,
as to be hardly fit for use.
No. 12 (page 74, second note). See in Thoreau's Excursions, an
interesting description of the wild apple-trees of Massachusetts.
No. 13 (page 86, first paragraph). It is said at Courmayeur that a very
few ibexes of a larger variety than those of the Cogne mountains, still linger
Page 516
about the Grande Jorasse.
No. 14 (page 92, first note). 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 plantations 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.
No. 15 (page 93, second note). The appearance of the dove-like grouse,
Tetrao paradoxus, or Syrrhaptes Pallasii, in various parts of Europe, in
1859 and the following years, is a noticeable 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 not
recorded to have been observed in Europe, or at least west of Russia, until
the year abovementioned, 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 they would breed
and remain permanently in the island, but this expectation has been
disappointed, and the steppe-grouse seems to have disappeared again
altogether.
No. 16 (page 94, note). From an article by A. Esquiros, in the Revue des
Deux Mondes for Sept. 1, 1864, entitled, La vie Anglaise, p. 119, it appears
that such occurrences as that stated in the note are not unfrequent on the
British coast.
No. 17 (page 100, first paragraph). I cannot learn that caprification is
now practised in Italy, but it is still in use in Greece.
No. 18 (page 112, first note). 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 1859 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
No. 14 (page 92, first note). 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 plantations 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.
No. 15 (page 93, second note). The appearance of the dove-like grouse,
Tetrao paradoxus, or Syrrhaptes Pallasii, in various parts of Europe, in
1859 and the following years, is a noticeable 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 not
recorded to have been observed in Europe, or at least west of Russia, until
the year abovementioned, 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 they would breed
and remain permanently in the island, but this expectation has been
disappointed, and the steppe-grouse seems to have disappeared again
altogether.
No. 16 (page 94, note). From an article by A. Esquiros, in the Revue des
Deux Mondes for Sept. 1, 1864, entitled, La vie Anglaise, p. 119, it appears
that such occurrences as that stated in the note are not unfrequent on the
British coast.
No. 17 (page 100, first paragraph). I cannot learn that caprification is
now practised in Italy, but it is still in use in Greece.
No. 18 (page 112, first note). 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 1859 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
Page 517
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.
No. 19 (page 121, first note). The Beduins are little given to the chase,
and seldom make war on the game birds and quadrupeds of the desert.
Hence the wild animals of Arabia are less timid than those of Europe. On
one occasion, when I was encamped during a sand storm of some violence
in Arabia Petræa, a wild pigeon took refuge in one of our tents which had
not been blown down, and remained quietly perched on a boy in the midst
of four or five persons, until the storm was over, and then took his
departure, insalutato hospite.
No. 20 (page 122). It is possible that time may modify the habits of the
fresh water fish of the North American States, and accommodate them to
the now physical conditions of their native waters. Hence it may be hoped
that nature, even unaided by art, will do something toward restoring the
ancient plenty of our lakes and rivers. The decrease of our fresh water fish
cannot be ascribed 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.
No. 21 (page 131, note). Vaupell, though agreeing with other writers as
to the injury done to the forest by most domestic animals—which he
illustrates in an interesting way in his posthumous work, The Danish Woods
—thinks, nevertheless, 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 Danske Skore, p. 12.
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.
No. 19 (page 121, first note). The Beduins are little given to the chase,
and seldom make war on the game birds and quadrupeds of the desert.
Hence the wild animals of Arabia are less timid than those of Europe. On
one occasion, when I was encamped during a sand storm of some violence
in Arabia Petræa, a wild pigeon took refuge in one of our tents which had
not been blown down, and remained quietly perched on a boy in the midst
of four or five persons, until the storm was over, and then took his
departure, insalutato hospite.
No. 20 (page 122). It is possible that time may modify the habits of the
fresh water fish of the North American States, and accommodate them to
the now physical conditions of their native waters. Hence it may be hoped
that nature, even unaided by art, will do something toward restoring the
ancient plenty of our lakes and rivers. The decrease of our fresh water fish
cannot be ascribed 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.
No. 21 (page 131, note). Vaupell, though agreeing with other writers as
to the injury done to the forest by most domestic animals—which he
illustrates in an interesting way in his posthumous work, The Danish Woods
—thinks, nevertheless, 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 Danske Skore, p. 12.
Page 518
No. 22 (page 135, note). The able authors of Humphreys and Abbot's
most valuable Report on the Physics and Hydraulics of the Mississippi,
conclude that the delta of that river 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.
The change in the character of the river must, if this opinion is well
founded, be due to some geological revolution, or at least convulsion, and
the hypothesis of the former existence of one or more great lakes in its
upper valley, whose bottoms are occupied by the present prairie region, has
been suggested. The shores of these supposed lakes have not, I believe,
been traced, or even detected, and we cannot admit the truth of this
hypothesis without supposing changes much more extensive than the mere
bursting of the barrier which confined the waters.
No. 23 (page 143, note). 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 seqq.
No. 24 (page 159, second paragraph). 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 therefore more organic heat is
developed?
No. 25 (page 191, first paragraph). 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. But if mountains do not really draw
clouds and invisible vapors to them, they are an exception to the universal
most valuable Report on the Physics and Hydraulics of the Mississippi,
conclude that the delta of that river 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.
The change in the character of the river must, if this opinion is well
founded, be due to some geological revolution, or at least convulsion, and
the hypothesis of the former existence of one or more great lakes in its
upper valley, whose bottoms are occupied by the present prairie region, has
been suggested. The shores of these supposed lakes have not, I believe,
been traced, or even detected, and we cannot admit the truth of this
hypothesis without supposing changes much more extensive than the mere
bursting of the barrier which confined the waters.
No. 23 (page 143, note). 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 seqq.
No. 24 (page 159, second paragraph). 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 therefore more organic heat is
developed?
No. 25 (page 191, first paragraph). 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. But if mountains do not really draw
clouds and invisible vapors to them, they are an exception to the universal
Page 519
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 hundreds of tons, and floating
freely in the atmosphere within moderate distances of the mountains?
No. 26 (page 198, note). Élisée Redus ascribes the diminution of the
ponds which border the dunes of Gascony to the absorption of their water
by the trees which have been planted upon the sands.—Revue des Deux
Mondes, 1 Aug., 1863, p. 694.
No. 27 (page 219, note). 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 1834, 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, 1 June, 1864, p. 601.
No. 28 (page 231, note). In a remarkable pamphlet, to which I shall
have occasion to refer more than once hereafter, entitled Avant-projet pour
la création d'un sol fertile à la surface des Landes de Gascogne, Duponchel
argues with much force, that the fertilizing properties of river-slime are
generally due much more to its mineral than to its vegetable constituents.
No. 29 (page 265, note). 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.
This art was known to and practised by the ancient lapidaries, and it has
been revived in recent times.
No. 30 (page 268). 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 über die Untersuchung der Schweizerischen
Hochgebirgswaldungen. 1862. P. 61.
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 hundreds of tons, and floating
freely in the atmosphere within moderate distances of the mountains?
No. 26 (page 198, note). Élisée Redus ascribes the diminution of the
ponds which border the dunes of Gascony to the absorption of their water
by the trees which have been planted upon the sands.—Revue des Deux
Mondes, 1 Aug., 1863, p. 694.
No. 27 (page 219, note). 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 1834, 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, 1 June, 1864, p. 601.
No. 28 (page 231, note). In a remarkable pamphlet, to which I shall
have occasion to refer more than once hereafter, entitled Avant-projet pour
la création d'un sol fertile à la surface des Landes de Gascogne, Duponchel
argues with much force, that the fertilizing properties of river-slime are
generally due much more to its mineral than to its vegetable constituents.
No. 29 (page 265, note). 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.
This art was known to and practised by the ancient lapidaries, and it has
been revived in recent times.
No. 30 (page 268). 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 über die Untersuchung der Schweizerischen
Hochgebirgswaldungen. 1862. P. 61.
Page 520
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.
No. 31 (page 286, note). It should have been 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.
No. 32 (page 293, note). Gaudry estimates the ties employed in the
railways of France at thirty millions, to supply which not less than two
millions of large trees have been felled. These ties have been, upon the
average, at least once renewed, and hence we must double the number of
ties and of trees required to furnish them.—Revue des Deux Mondes, 15
July, 1863, p. 425.
No. 33 (page 294, second paragraph of note). After all, the present
consumption of wood and timber for fuel and other domestic and rural
purposes, in many parts of Europe, seems incredibly small to an American.
In rural Switzerland, the whole supply of firewood, fuel for small
smitheries, dairies, breweries, brick and lime kilns, distilleries, fences,
furniture, tools, and even house building—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 an average of two hundred
and thirty cubic feet, or less than two cords, a year per household. The
average consumption of wood in New England for domestic fuel alone, is
from five to ten times as much as Swiss families require for all the uses
above enumerated. But the existing habitations of Switzerland are sufficient
for a population which increases but slowly, and in the peasants' houses but
a single room is usually heated. See Bericht über die Untersuchung der
Schweiz. Hochgebirgswaldungen, pp. 85-89.
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.
No. 31 (page 286, note). It should have been 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.
No. 32 (page 293, note). Gaudry estimates the ties employed in the
railways of France at thirty millions, to supply which not less than two
millions of large trees have been felled. These ties have been, upon the
average, at least once renewed, and hence we must double the number of
ties and of trees required to furnish them.—Revue des Deux Mondes, 15
July, 1863, p. 425.
No. 33 (page 294, second paragraph of note). After all, the present
consumption of wood and timber for fuel and other domestic and rural
purposes, in many parts of Europe, seems incredibly small to an American.
In rural Switzerland, the whole supply of firewood, fuel for small
smitheries, dairies, breweries, brick and lime kilns, distilleries, fences,
furniture, tools, and even house building—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 an average of two hundred
and thirty cubic feet, or less than two cords, a year per household. The
average consumption of wood in New England for domestic fuel alone, is
from five to ten times as much as Swiss families require for all the uses
above enumerated. But the existing habitations of Switzerland are sufficient
for a population which increases but slowly, and in the peasants' houses but
a single room is usually heated. See Bericht über die Untersuchung der
Schweiz. Hochgebirgswaldungen, pp. 85-89.
Page 521
No. 34 (page 304). Among more recent manuals may be mentioned: Les
Études de Maitre Pierre. Paris, 1864. 12mo; Bazelaire, Traité de
Reboisement. 2d edition, Paris, 1864; and, in Italian, Siemoni, Manuale
teorico-pratico d'arte Forestale. Firenze, 1864. 8vo. A very important work
has lately been published in France by Viscount de Courval, which is
known to me only by a German translation published at Berlin, in 1864,
under the title, Das Aufästen der Waldbäume. The principal feature of De
Courval's very successful system of sylviculture, is a 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.
No. 35 (page 313). 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 hill-sides 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
—has a very eloquent paper on the "Autumnal Tints" of the New England
landscape.—See his Excursions, pp. 215 et seqq.
Études de Maitre Pierre. Paris, 1864. 12mo; Bazelaire, Traité de
Reboisement. 2d edition, Paris, 1864; and, in Italian, Siemoni, Manuale
teorico-pratico d'arte Forestale. Firenze, 1864. 8vo. A very important work
has lately been published in France by Viscount de Courval, which is
known to me only by a German translation published at Berlin, in 1864,
under the title, Das Aufästen der Waldbäume. The principal feature of De
Courval's very successful system of sylviculture, is a 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.
No. 35 (page 313). 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 hill-sides 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
—has a very eloquent paper on the "Autumnal Tints" of the New England
landscape.—See his Excursions, pp. 215 et seqq.
Page 522
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
capacious eye that takes in all the visible facts in the history of the most
familiar natural object.—The Maine Woods, p. 184.
"The luminous appearance of bodies projected against the sky adjacent
to the rising" or setting sun, so well described in Professor Necker's Letter
to Sir David Brewster, is, as Tyndall observes, "hardly ever seen by either
guides or travellers, though it would seem, prima facie, that it must be of
frequent occurrence." See Tyndall, Glaciers of the Alps. Part I. Second
ascent of Mont Blanc.
Judging from my own observation, however, I should much doubt
whether this brilliant phenomenon can be so often seen in perfection as
would be expected; for I have frequently sought it in vain at the foot of the
Alps, under conditions apparently otherwise identical with those where, in
the elevated Alpine valleys, it shows itself in the greatest splendor.
No. 36 (page 314). 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.
No. 37 (page 316, first note). Charles Martin ascribes the power of
reproduction by shoots from the stump to the cedar of Mount Atlas, which
appears to be identical with the cedar of Lebanon.—Revue des Deux
Mondes, 15 July, 1864, p. 315.
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
capacious eye that takes in all the visible facts in the history of the most
familiar natural object.—The Maine Woods, p. 184.
"The luminous appearance of bodies projected against the sky adjacent
to the rising" or setting sun, so well described in Professor Necker's Letter
to Sir David Brewster, is, as Tyndall observes, "hardly ever seen by either
guides or travellers, though it would seem, prima facie, that it must be of
frequent occurrence." See Tyndall, Glaciers of the Alps. Part I. Second
ascent of Mont Blanc.
Judging from my own observation, however, I should much doubt
whether this brilliant phenomenon can be so often seen in perfection as
would be expected; for I have frequently sought it in vain at the foot of the
Alps, under conditions apparently otherwise identical with those where, in
the elevated Alpine valleys, it shows itself in the greatest splendor.
No. 36 (page 314). 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.
No. 37 (page 316, first note). Charles Martin ascribes the power of
reproduction by shoots from the stump to the cedar of Mount Atlas, which
appears to be identical with the cedar of Lebanon.—Revue des Deux
Mondes, 15 July, 1864, p. 315.
Page 523
No. 38 (page 332). In an interesting article on recent internal
improvements in England, in the London Quarterly Review for January,
1858, it is related that in a single rock cutting on the Liverpool and
Manchester railway, 480,000 cubic yards of stone were removed; that the
earth excavated and removed 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.
No. 39 (page 339). According to Reventlov, whose work is one of the
best sources of information on the subject of diking-in tide-washed flats,
Salicornia herbacea appears as soon as the flat is raised high enough to be
dry for three hours at ordinary ebb tide, or, in other words, where the
ordinary flood covers it to a depth of not more than two feet. At a flood
depth of one foot, the Salicornia dies and is succeeded by various sand
plants. These are followed by Poa distans and Poa maritima as the ground
is raised by further deposits, and these plants finally by common grasses.
The Salicornia is preceded by confervæ, growing in deeper water, which
spread over the bottom, and when covered by a fresh deposit of slime
reappear above it, and thus vegetable and alluvial strata alternate until the
flat is raised sufficiently high for the growth of Salicornia.—Om
Marskdannelsen paa Vestkysten af Hertugdömmet Slesvig, pp. 7, 8.
No. 40 (page 348, note). The drijftil employed for the ring dike of the
Lake of Haarlem, was in part cut in sections fifty feet long by six or seven
wide, and these were navigated like rafts to the spot where they were sunk
to form the dike.—Emile de Laveleye, Revue des Deux Mondes, 15 Sept.,
1863, p. 285.
No. 41 (page 352, last paragraph). See on the influence of the
improvements in question on tidal and other marine currents, Staring, De
Bodem van Nederland, I. p. 279.
Although the dikes of the Netherlands and the adjacent states have
protected a considerable extent of coast from the encroachments of the sea,
and have won a large tract of cultivable land from the dominion of the
waters, it has been questioned whether a different method of accomplishing
improvements in England, in the London Quarterly Review for January,
1858, it is related that in a single rock cutting on the Liverpool and
Manchester railway, 480,000 cubic yards of stone were removed; that the
earth excavated and removed 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.
No. 39 (page 339). According to Reventlov, whose work is one of the
best sources of information on the subject of diking-in tide-washed flats,
Salicornia herbacea appears as soon as the flat is raised high enough to be
dry for three hours at ordinary ebb tide, or, in other words, where the
ordinary flood covers it to a depth of not more than two feet. At a flood
depth of one foot, the Salicornia dies and is succeeded by various sand
plants. These are followed by Poa distans and Poa maritima as the ground
is raised by further deposits, and these plants finally by common grasses.
The Salicornia is preceded by confervæ, growing in deeper water, which
spread over the bottom, and when covered by a fresh deposit of slime
reappear above it, and thus vegetable and alluvial strata alternate until the
flat is raised sufficiently high for the growth of Salicornia.—Om
Marskdannelsen paa Vestkysten af Hertugdömmet Slesvig, pp. 7, 8.
No. 40 (page 348, note). The drijftil employed for the ring dike of the
Lake of Haarlem, was in part cut in sections fifty feet long by six or seven
wide, and these were navigated like rafts to the spot where they were sunk
to form the dike.—Emile de Laveleye, Revue des Deux Mondes, 15 Sept.,
1863, p. 285.
No. 41 (page 352, last paragraph). See on the influence of the
improvements in question on tidal and other marine currents, Staring, De
Bodem van Nederland, I. p. 279.
Although the dikes of the Netherlands and the adjacent states have
protected a considerable extent of coast from the encroachments of the sea,
and have won a large tract of cultivable land from the dominion of the
waters, it has been questioned whether a different method of accomplishing
Page 524
these objects might not have been adopted with advantage. It has been
suggested that a system of inland dikes and canals, upon the principle of
those which, as will be seen in a subsequent part of the chapter on the
waters, 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 possible that the territory of those states
would have been as extensive as it now is, and, at the same time, more
elevated by several feet. But it must be borne in mind that we do not know
the proportions in which the marine deposits that form 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 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. Klöden
states the quantity of sedimentary matter now annually brought down by the
Rhine at Bonn to be sufficient only to cover a square English mile to the
depth of a little more than a foot.—Erdkunde, I. p. 384.
No. 42 (page 358, first paragraph). Meteorological observations have
been regularly recorded at Zwanenburg, near the north end of the Lake of
Haarlem, for more than a century, and since 1845 a similar register has been
kept at the Helder, forty or fifty miles farther north. In comparing these two
series of observations, it is found that about the end of the year 1852, when
the drawing off of the waters of the Lake of Haarlem was completed, and
suggested that a system of inland dikes and canals, upon the principle of
those which, as will be seen in a subsequent part of the chapter on the
waters, 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 possible that the territory of those states
would have been as extensive as it now is, and, at the same time, more
elevated by several feet. But it must be borne in mind that we do not know
the proportions in which the marine deposits that form 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 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. Klöden
states the quantity of sedimentary matter now annually brought down by the
Rhine at Bonn to be sufficient only to cover a square English mile to the
depth of a little more than a foot.—Erdkunde, I. p. 384.
No. 42 (page 358, first paragraph). Meteorological observations have
been regularly recorded at Zwanenburg, near the north end of the Lake of
Haarlem, for more than a century, and since 1845 a similar register has been
kept at the Helder, forty or fifty miles farther north. In comparing these two
series of observations, it is found that about the end of the year 1852, when
the drawing off of the waters of the Lake of Haarlem was completed, and
Page 525
the preceding summer had dried the grounds laid bare so as greatly to
reduce the evaporable surface, a change took place in the relative
temperature of the two stations. Taking the mean of every successive period
of five days from 1845 to 1852, the temperature at Zwanenburg was thirty-
three hundredths of a centigrade degree lower than at the Helder. Since the
end of 1852, the thermometer at Zwanenburg has stood, from the 11th of
April to the 20th of September inclusive, twenty-two hundredths of a
degree higher than at the Helder, but from the 14th of October to the 17th of
March, it has averaged one-tenth of a degree lower than its mean between
the same dates before 1853.
There is no reasonable doubt that these differences are due to the
draining of the lake. There has been less refrigeration from evaporation in
summer, and the ground has absorbed more solar heat at the same period,
while in the winter it has radiated more warmth then when it was covered
with water. Doubtless the quantity of humidity contained in the atmosphere
has also been affected by the same cause, but observations do not appear to
have been made on that point. See Krecke, Het Klimaat van Nederland, II.
64.
No. 43 (page 358, note). In the course of the present year (1864), there
have been several land slips on the borders of the Lake of Como, and in one
instance the grounds of a villa lying upon the margin of the water suffered a
considerable displacement. If the lake should be lowered to any
considerable extent, in pursuance of the plan mentioned in the note on page
358, there is ground to fear that the steep shores of the lake might, at some
points, be deprived of a lateral pressure requisite to their stability, and slide
into the water as on the Lake of Lungern. See p. 356.
No. 44 (page 369, last paragraph but one of note). 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.
No. 45 (page 375, note). 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
reduce the evaporable surface, a change took place in the relative
temperature of the two stations. Taking the mean of every successive period
of five days from 1845 to 1852, the temperature at Zwanenburg was thirty-
three hundredths of a centigrade degree lower than at the Helder. Since the
end of 1852, the thermometer at Zwanenburg has stood, from the 11th of
April to the 20th of September inclusive, twenty-two hundredths of a
degree higher than at the Helder, but from the 14th of October to the 17th of
March, it has averaged one-tenth of a degree lower than its mean between
the same dates before 1853.
There is no reasonable doubt that these differences are due to the
draining of the lake. There has been less refrigeration from evaporation in
summer, and the ground has absorbed more solar heat at the same period,
while in the winter it has radiated more warmth then when it was covered
with water. Doubtless the quantity of humidity contained in the atmosphere
has also been affected by the same cause, but observations do not appear to
have been made on that point. See Krecke, Het Klimaat van Nederland, II.
64.
No. 43 (page 358, note). In the course of the present year (1864), there
have been several land slips on the borders of the Lake of Como, and in one
instance the grounds of a villa lying upon the margin of the water suffered a
considerable displacement. If the lake should be lowered to any
considerable extent, in pursuance of the plan mentioned in the note on page
358, there is ground to fear that the steep shores of the lake might, at some
points, be deprived of a lateral pressure requisite to their stability, and slide
into the water as on the Lake of Lungern. See p. 356.
No. 44 (page 369, last paragraph but one of note). 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.
No. 45 (page 375, note). 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
Page 526
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.
No. 46 (page 378). We have seen in Appendix, No. 42, ante, that the
mean temperature of a station on the borders of the Lake of Haarlem—a
sheet of water formerly covering sixty-two and a half square English miles
—for the period between the 11th of April and the 20th of September, had
been raised not less than a degree of Fahrenheit by the draining of that lake;
or, to state the case more precisely, that the formation of the lake, which
was a consequence of man's improvidence, had reduced the temperature one
degree F. below the natural standard. The artificially irrigated lands of
France, Piedmont, and Lombardy, taken together, are fifty times as
extensive as the Lake of Haarlem, and they are situated in climates where
evaporation is vastly more rapid than in the Netherlands. They must
therefore, no doubt, affect the local climate to a far greater extent than has
been observed in connection with the draining of the lake in question. I do
not know that special observations have been made with a view to measure
the climatic effects of irrigation, but in the summer I have often found the
morning temperature, when the difference would naturally be least
perceptible, on the watered plains of Piedmont, nine miles south of Turin,
several degrees lower than that recorded at an observatory in the city.
No. 47 (page 391, note). 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 a slight depression since the piers of the aqueduct were
founded.
No. 48 (page 393, first note). 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
instead of carrying it to the sea. The colmate of modern Italy were thus
anticipated in ancient Egypt.
No. 46 (page 378). We have seen in Appendix, No. 42, ante, that the
mean temperature of a station on the borders of the Lake of Haarlem—a
sheet of water formerly covering sixty-two and a half square English miles
—for the period between the 11th of April and the 20th of September, had
been raised not less than a degree of Fahrenheit by the draining of that lake;
or, to state the case more precisely, that the formation of the lake, which
was a consequence of man's improvidence, had reduced the temperature one
degree F. below the natural standard. The artificially irrigated lands of
France, Piedmont, and Lombardy, taken together, are fifty times as
extensive as the Lake of Haarlem, and they are situated in climates where
evaporation is vastly more rapid than in the Netherlands. They must
therefore, no doubt, affect the local climate to a far greater extent than has
been observed in connection with the draining of the lake in question. I do
not know that special observations have been made with a view to measure
the climatic effects of irrigation, but in the summer I have often found the
morning temperature, when the difference would naturally be least
perceptible, on the watered plains of Piedmont, nine miles south of Turin,
several degrees lower than that recorded at an observatory in the city.
No. 47 (page 391, note). 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 a slight depression since the piers of the aqueduct were
founded.
No. 48 (page 393, first note). 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
Page 527
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."—Avant-projet pour la
création d'un sol fertile, etc., p. 20.
No. 49 (page 404, first paragraph of second note). 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
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 embankments 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 first to
excavate, then to raise, their beds. No general law on this point can be
stated in relation to the middle and lower course 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 formulæ, and
they can scarcely even be enumerated. See, however, note on p. 431.
No. 50 (page 406, first paragraph). The system proposed in the text is
substantially the Egyptian method, the Nile dikes having been constructed
rather to retain than to exclude the water. 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, and consequently the
immediate banks of such rivers become higher than the grounds lying
farther from the stream. In the "intervals," 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, though less so than in the valley of the Mississippi, where, below
Cape Girardeau, the alluvial banks constitute natural glacis descending as
you recede from the river, at an average of seven feet in the first mile.—
Humphreys and Abbot's Report, pp. 96, 97.
The Egyptian crossdikes, by retaining the water of the inundations,
compel it to let fall its remaining slime, and hence the elevation of 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."—Avant-projet pour la
création d'un sol fertile, etc., p. 20.
No. 49 (page 404, first paragraph of second note). 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
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 embankments 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 first to
excavate, then to raise, their beds. No general law on this point can be
stated in relation to the middle and lower course 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 formulæ, and
they can scarcely even be enumerated. See, however, note on p. 431.
No. 50 (page 406, first paragraph). The system proposed in the text is
substantially the Egyptian method, the Nile dikes having been constructed
rather to retain than to exclude the water. 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, and consequently the
immediate banks of such rivers become higher than the grounds lying
farther from the stream. In the "intervals," 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, though less so than in the valley of the Mississippi, where, below
Cape Girardeau, the alluvial banks constitute natural glacis descending as
you recede from the river, at an average of seven feet in the first mile.—
Humphreys and Abbot's Report, pp. 96, 97.
The Egyptian crossdikes, by retaining the water of the inundations,
compel it to let fall its remaining slime, and hence the elevation of the
Page 528
remoter land goes on at a rate not very much slower than that of the
immediate banks. Probably transverse embankments would produce the
same effect in the Mississippi valley. In the great floods of this river, it is
observed that, at a certain distance from the channel, the bottoms, though
lower than the banks, are flooded to a less depth. See cross sections in Plate
IV. of Humphreys and Abbot's Report. This apparently anomalous fact is
due, I suppose, to the greater swiftness of the current of the overflowing
water in the low grounds, which are often drained through the channels of
rivers whose beds lie at a lower level than that of the Mississippi, or by the
bayous which are so characteristic a feature of the geography of that valley.
A judicious use of dikes would probably convert the swamps of the lower
Mississippi valley into a region like Egypt.
No. 51 (second note). 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 sis 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 Abbot's Report, p.
93.
No. 52 (page 423, first paragraph). Artificially directed currents of
water have been advantageously used in civil engineering for displacing
and transporting large quantities of earth, and there is no doubt that this
agency might be profitably employed to a far greater extent than has yet
been attempted. Some of the hydraulic works in California for washing
down masses of auriferous earth are on a scale stupenduous enough to
produce really important topographical changes.
No. 53 (page 435, first note). I have lately been informed by a resident
of the Ionian Islands, who is familiar with this phenomenon, that the sea
flows uninterruptedly into the sub-insular cavities, at all stages of the tide.
No. 54 (page 438, note). It is observed in Cornwall that deep mines are
freer from water in artificially well-drained, than in undrained agricultural
districts.—Esquiros, Revue des Deux Mondes, Nov. 15, 1863, p. 430.
immediate banks. Probably transverse embankments would produce the
same effect in the Mississippi valley. In the great floods of this river, it is
observed that, at a certain distance from the channel, the bottoms, though
lower than the banks, are flooded to a less depth. See cross sections in Plate
IV. of Humphreys and Abbot's Report. This apparently anomalous fact is
due, I suppose, to the greater swiftness of the current of the overflowing
water in the low grounds, which are often drained through the channels of
rivers whose beds lie at a lower level than that of the Mississippi, or by the
bayous which are so characteristic a feature of the geography of that valley.
A judicious use of dikes would probably convert the swamps of the lower
Mississippi valley into a region like Egypt.
No. 51 (second note). 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 sis 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 Abbot's Report, p.
93.
No. 52 (page 423, first paragraph). Artificially directed currents of
water have been advantageously used in civil engineering for displacing
and transporting large quantities of earth, and there is no doubt that this
agency might be profitably employed to a far greater extent than has yet
been attempted. Some of the hydraulic works in California for washing
down masses of auriferous earth are on a scale stupenduous enough to
produce really important topographical changes.
No. 53 (page 435, first note). I have lately been informed by a resident
of the Ionian Islands, who is familiar with this phenomenon, that the sea
flows uninterruptedly into the sub-insular cavities, at all stages of the tide.
No. 54 (page 438, note). It is observed in Cornwall that deep mines are
freer from water in artificially well-drained, than in undrained agricultural
districts.—Esquiros, Revue des Deux Mondes, Nov. 15, 1863, p. 430.
Page 529
No. 55 (page 441). See, on the Artesian wells of the Sahara, and
especially on the throwing up of living fish by them, an article entitled, Le
Sahara, etc., by Charles Martins, in the Revue des Deux Mondes for August
1, 1864, pp. 618, 619.
No. 56 (page 444, first note). From the article in the Rev. des Deux
Mondes, referred to in the preceding note, it appears that the wells
discovered by Ayme were truly artesian. They were bored in rock, and
provided at the outlet with a pear-shaped valve of stone, by which the
orifice could be closed or opened at pleasure.
No. 57 (page 447, second note). 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 latter, may be carried by rain in the case of dunes, or by the ordinary
action of sea water in that of subaqueous sandbanks, down through the
interstices in the coarser layer, and thus the relative position of fine sand
and gravel may be more or less changed.—Oorsprong der Hollandsche
Duinen, p. 103.
No. 58 (page 479). It appears from Laurent, that marine shells, of extant
species, are found in the sands of the Sahara, far from the sea, and even at
considerable depths below the surface.—Mémoires sur le Sahara Oriental,
p. 62.
This observation has been confirmed by late travellers, and is an
important link in the chain of evidence which tends to prove that the
upheaval of the Libyan desert is of comparatively recent date.
No. 59 (p. 480). "At New Quay [in England] the dune sands are
converted to stone by an oxyde 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 employed for building."—Esquiros,
L'Angleterre et la vie Anglaise, Revue des Deux Mondes, 1 March, 1864,
pp. 44, 45.
No. 60 (page 496, first paragraph). In Ditmarsh, the breaking of the
surface by the manœuvering of a corps of cavalry let loose a sand-drift
especially on the throwing up of living fish by them, an article entitled, Le
Sahara, etc., by Charles Martins, in the Revue des Deux Mondes for August
1, 1864, pp. 618, 619.
No. 56 (page 444, first note). From the article in the Rev. des Deux
Mondes, referred to in the preceding note, it appears that the wells
discovered by Ayme were truly artesian. They were bored in rock, and
provided at the outlet with a pear-shaped valve of stone, by which the
orifice could be closed or opened at pleasure.
No. 57 (page 447, second note). 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 latter, may be carried by rain in the case of dunes, or by the ordinary
action of sea water in that of subaqueous sandbanks, down through the
interstices in the coarser layer, and thus the relative position of fine sand
and gravel may be more or less changed.—Oorsprong der Hollandsche
Duinen, p. 103.
No. 58 (page 479). It appears from Laurent, that marine shells, of extant
species, are found in the sands of the Sahara, far from the sea, and even at
considerable depths below the surface.—Mémoires sur le Sahara Oriental,
p. 62.
This observation has been confirmed by late travellers, and is an
important link in the chain of evidence which tends to prove that the
upheaval of the Libyan desert is of comparatively recent date.
No. 59 (p. 480). "At New Quay [in England] the dune sands are
converted to stone by an oxyde 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 employed for building."—Esquiros,
L'Angleterre et la vie Anglaise, Revue des Deux Mondes, 1 March, 1864,
pp. 44, 45.
No. 60 (page 496, first paragraph). In Ditmarsh, the breaking of the
surface by the manœuvering of a corps of cavalry let loose a sand-drift
Page 530
which did serious injury before it was subdued.—Kohl, Inseln u.
Marschen. etc., III. p. 282.
Similar cases have occurred in Eastern Massachusetts, from equally
slight causes.—See Thoreau, A Week on the Concord and Merrimack
Rivers, pp. 151-208.
No. 61 (page 497, last note). A more probable explanation of the fact
stated in the note is suggested by Èlisée Reclus, in an article entitled, Le
Littoral de la France, in the Revue des Deux Mondes for Sept. 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.
No. 62 (page 506, note). The statement in the note is confirmed by
Olmsted: "There is not a sufficient demand for rosin, except of the first
qualities, to make it worth transporting from the inland distilleries; it is
ordinarily, therefore, conducted off to a little distance, in a wooden trough,
and allowed to flow from it to waste upon the ground. At the first distillery I
visited, which had been in operation but one year, there lay a congealed
pool of rosin, estimated to contain over three thousand barrels."—A Journey
in the Seaboard Slave States, 1863, p. 345.
No. 63 (page 507). 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 Northwest 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.
No. 64 (page 512, last paragraph). For a brilliant account of the
improvement of the Landes, see Edmond About, Le Progrès, Chap, VII.
In the memoir referred to in Appendix, No. 48, ante, Duponchel
proposes the construction of artificial torrents to grind calcareous rock to
slime by rolling and attrition in its bed, and, at the same time, the washing
Marschen. etc., III. p. 282.
Similar cases have occurred in Eastern Massachusetts, from equally
slight causes.—See Thoreau, A Week on the Concord and Merrimack
Rivers, pp. 151-208.
No. 61 (page 497, last note). A more probable explanation of the fact
stated in the note is suggested by Èlisée Reclus, in an article entitled, Le
Littoral de la France, in the Revue des Deux Mondes for Sept. 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.
No. 62 (page 506, note). The statement in the note is confirmed by
Olmsted: "There is not a sufficient demand for rosin, except of the first
qualities, to make it worth transporting from the inland distilleries; it is
ordinarily, therefore, conducted off to a little distance, in a wooden trough,
and allowed to flow from it to waste upon the ground. At the first distillery I
visited, which had been in operation but one year, there lay a congealed
pool of rosin, estimated to contain over three thousand barrels."—A Journey
in the Seaboard Slave States, 1863, p. 345.
No. 63 (page 507). 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 Northwest 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.
No. 64 (page 512, last paragraph). For a brilliant account of the
improvement of the Landes, see Edmond About, Le Progrès, Chap, VII.
In the memoir referred to in Appendix, No. 48, ante, Duponchel
proposes the construction of artificial torrents to grind calcareous rock to
slime by rolling and attrition in its bed, and, at the same time, the washing
Page 531
down of an argillaceous deposit which is to be mixed with the calcareous
slime and distributed over the Landes by watercourses constructed for the
purpose. By this means, he supposes that a highly fertile soil could be
formed on the surface, which would also be so raised by the process as to
admit of freer drainage. That nothing may be wanting to recommend this
project, Duponchel suggests that, as some of the rivers of Western France
are auriferous, it is probable that gold enough may be collected from the
washings to reduce the cost of the operations materially.
No. 65 (page 528, first paragraph). 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 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.
slime and distributed over the Landes by watercourses constructed for the
purpose. By this means, he supposes that a highly fertile soil could be
formed on the surface, which would also be so raised by the process as to
admit of freer drainage. That nothing may be wanting to recommend this
project, Duponchel suggests that, as some of the rivers of Western France
are auriferous, it is probable that gold enough may be collected from the
washings to reduce the cost of the operations materially.
No. 65 (page 528, first paragraph). 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 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.
Page 532
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.
No. 66 (page 548, first paragraph). 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.
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.
No. 66 (page 548, first paragraph). 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.
Page 533
INDEX
Page 534
Abbeys of St. Germain and St. Denis, revenues of, 6.
Adirondack forest, 235;
lakes of, 357.
Ailanthus glandulosa, 515.
Akaba, gulf of, infiltration of fresh water in, 440.
Albano, lake of, artificial lowering of, 353.
Algeria, deserts of, artesian wells in, 443;
sand dunes of, 463;
consolidated dunes, 480.
Alpaca, South American, 83.
Amazon, Indians of, 11.
Ameland, island of, 499.
America, North, primitive physical condition of, 27, 43;
forests of, 28;
possibility of noting its physical changes, 52;
by scientific observation, 53;
forest trees of, 274;
sand dunes of, 469;
proposed changes in hydrography of, 532.
Animal life, sympathy of ruder races with, 39;
instinct, fallibility of, 40;
hostility of civilized man to inferior forms of, 121.
Animals, wild, action of on vegetation, 78.
Aphis, the European, 104.
Apennines, effects of felling the woods on, 150, 152.
Appian way, the, 542.
Aqueducts, geographical and climatic effects of, 358.
Arabia Petræa, surface drainage of, 440;
sandstone of, 452;
sands and petrified wood of, 455;
wadies of, 538.
Aragua, valley of, Venezuela, 202.
Adirondack forest, 235;
lakes of, 357.
Ailanthus glandulosa, 515.
Akaba, gulf of, infiltration of fresh water in, 440.
Albano, lake of, artificial lowering of, 353.
Algeria, deserts of, artesian wells in, 443;
sand dunes of, 463;
consolidated dunes, 480.
Alpaca, South American, 83.
Amazon, Indians of, 11.
Ameland, island of, 499.
America, North, primitive physical condition of, 27, 43;
forests of, 28;
possibility of noting its physical changes, 52;
by scientific observation, 53;
forest trees of, 274;
sand dunes of, 469;
proposed changes in hydrography of, 532.
Animal life, sympathy of ruder races with, 39;
instinct, fallibility of, 40;
hostility of civilized man to inferior forms of, 121.
Animals, wild, action of on vegetation, 78.
Aphis, the European, 104.
Apennines, effects of felling the woods on, 150, 152.
Appian way, the, 542.
Aqueducts, geographical and climatic effects of, 358.
Arabia Petræa, surface drainage of, 440;
sandstone of, 452;
sands and petrified wood of, 455;
wadies of, 538.
Aragua, valley of, Venezuela, 202.
Page 535
Ararat, Mt., phenomenon of vegetation on, 287.
Ardèche, l', department of, 152;
destruction of forests in, 389.
— river and basin, floods of, 386;
supply of water to the Rhone, 388, 398;
violence of inundations of, 388;
damage done by, 390;
effect on river beds, 391;
force of its affluents, 392.
Argostoli, Cephalonia, millstreams of, 434.
Armenia, ancient irrigation of, 366.
Arno, the river, deposits of, 414;
upper course of in the Val di Chiana, 417, 420.
Artesian wells, their sources, 441;
usual objects, 442;
occasional effects, 442;
employment in the Algerian desert, 443;
by the French Government, 444;
success and probable results of, 445;
known to the ancients, 443;
depth of, 444.
Arundo arenaria, 501.
Ascension, island of, 205.
Auk, the wingless, extirpation of, 95.
Australia a field of physical observation, 51.
Avalanches, Alpine, various causes of, 266;
by felling trees, 270.
Azoff, sea of, proposed changes, 531.
Babinet, plan for artificial springs, by, 448.
Baikal Lake, the fish of, 117.
Baltic Sea, sand dunes of, 467.
Barcelonette, valley of, former fertility, 243;
present degradation of, 244.
Ardèche, l', department of, 152;
destruction of forests in, 389.
— river and basin, floods of, 386;
supply of water to the Rhone, 388, 398;
violence of inundations of, 388;
damage done by, 390;
effect on river beds, 391;
force of its affluents, 392.
Argostoli, Cephalonia, millstreams of, 434.
Armenia, ancient irrigation of, 366.
Arno, the river, deposits of, 414;
upper course of in the Val di Chiana, 417, 420.
Artesian wells, their sources, 441;
usual objects, 442;
occasional effects, 442;
employment in the Algerian desert, 443;
by the French Government, 444;
success and probable results of, 445;
known to the ancients, 443;
depth of, 444.
Arundo arenaria, 501.
Ascension, island of, 205.
Auk, the wingless, extirpation of, 95.
Australia a field of physical observation, 51.
Avalanches, Alpine, various causes of, 266;
by felling trees, 270.
Azoff, sea of, proposed changes, 531.
Babinet, plan for artificial springs, by, 448.
Baikal Lake, the fish of, 117.
Baltic Sea, sand dunes of, 467.
Barcelonette, valley of, former fertility, 243;
present degradation of, 244.
Page 536
Bavaria, scarcity of fuel in, 299.
Bear, the mythical character of, 40.
Beaver, the, agency in forming bogs, 31;
cause of its increased numbers, 84.
Bee, the honey, products of, 105;
introduction in United States, 106.
Belgium, effect of plantations in, 152;
Campine of, 513.
Ben Gâsi, district of, rock formation in, 537.
Bergamo, change of climate in the valley of, 151.
Bibliographical list of authorities, vii.
Birch tree (black and yellow), produce of, 171.
Birds, number of, in United States, 86;
the turkey, dove, pigeon, 87;
as sowers and consumers of seeds, 87;
as destroyers of insects, 89;
injurious extirpation of, 90;
wanton destruction of, 92;
weakness of, 93;
instinct of migratory, 94;
extinction of species, 95;
commercial value of, 97;
introduction of species, 98.
Bison, the American, 78;
number and migrations of, 81, 83;
domesticated, 135.
Blackbird, the proscription of, 91.
Bogs, formation and nomenclature of, 29-32;
of New England, 29;
repositories of fuel, 30.
Brémontier, system of dune plantations of, 503;
a benefactor to his race, 515.
Breton, Cap, dune vineyards of, 508.
Busbequius' letters, 64.
Bear, the mythical character of, 40.
Beaver, the, agency in forming bogs, 31;
cause of its increased numbers, 84.
Bee, the honey, products of, 105;
introduction in United States, 106.
Belgium, effect of plantations in, 152;
Campine of, 513.
Ben Gâsi, district of, rock formation in, 537.
Bergamo, change of climate in the valley of, 151.
Bibliographical list of authorities, vii.
Birch tree (black and yellow), produce of, 171.
Birds, number of, in United States, 86;
the turkey, dove, pigeon, 87;
as sowers and consumers of seeds, 87;
as destroyers of insects, 89;
injurious extirpation of, 90;
wanton destruction of, 92;
weakness of, 93;
instinct of migratory, 94;
extinction of species, 95;
commercial value of, 97;
introduction of species, 98.
Bison, the American, 78;
number and migrations of, 81, 83;
domesticated, 135.
Blackbird, the proscription of, 91.
Bogs, formation and nomenclature of, 29-32;
of New England, 29;
repositories of fuel, 30.
Brémontier, system of dune plantations of, 503;
a benefactor to his race, 515.
Breton, Cap, dune vineyards of, 508.
Busbequius' letters, 64.
Page 537
Camel, the, transfer and migrations of, 83;
injurious to vegetation, 132.
Campine of Belgium, 513.
Canada thistle, the, 68.
Canals, geographic and climatic effects of, 359;
injurious effects of Tuscan, 359;
projected, Suez, 519;
Isthmus of Darien, 522;
to the Dead Sea, 524;
maritime, in Greece, 526;
Saros, 527;
Cape Cod, 528;
the Don and the Volga, 531;
Lake Erie and the Genesee, 532;
Lake Michigan and the Mississippi, 533.
Cape Cod, sand dunes of, 487;
legislative protection of, 502;
vegetation of, 503;
projected canal through, 528.
Cappercailzie, the, extinction of, in Britain, 96.
Carniola, caves of, 434.
Caspian Sea, proposed changes in its basin, 531.
Catania, lava streams of, 544.
Catavothra of Greece, 536.
Cévennes, effects of clearing the, 153.
Champlain, lake, dates of its congelation, 163.
Cherbourg, breakwater of, 46, 332.
Chiana, Val di, description and character of, 417-420;
plans for its restoration, 420;
artificial drainage of, attempted, 421;
successfully executed, 423.
Clergy, mediæval, their character, 282.
Climatic change, discussions of, 9;
injurious to vegetation, 132.
Campine of Belgium, 513.
Canada thistle, the, 68.
Canals, geographic and climatic effects of, 359;
injurious effects of Tuscan, 359;
projected, Suez, 519;
Isthmus of Darien, 522;
to the Dead Sea, 524;
maritime, in Greece, 526;
Saros, 527;
Cape Cod, 528;
the Don and the Volga, 531;
Lake Erie and the Genesee, 532;
Lake Michigan and the Mississippi, 533.
Cape Cod, sand dunes of, 487;
legislative protection of, 502;
vegetation of, 503;
projected canal through, 528.
Cappercailzie, the, extinction of, in Britain, 96.
Carniola, caves of, 434.
Caspian Sea, proposed changes in its basin, 531.
Catania, lava streams of, 544.
Catavothra of Greece, 536.
Cévennes, effects of clearing the, 153.
Champlain, lake, dates of its congelation, 163.
Cherbourg, breakwater of, 46, 332.
Chiana, Val di, description and character of, 417-420;
plans for its restoration, 420;
artificial drainage of, attempted, 421;
successfully executed, 423.
Clergy, mediæval, their character, 282.
Climatic change, discussions of, 9;
Page 538
how tested, 20;
causes producing, in New England, Africa, Arabia Petræa, 20-22;
man's action on, difficult to ascertain, 51;
deterioration, 71.
Coal mines, combustion of, 546.
Coal, sea, early use of, for fuel, 222;
increased use of, in Paris, 295.
Coast line, change of, from natural causes, 331;
subject to human guidance, 332.
Cochineal insect transferred to Spain, 105.
Cochituate Aqueduct, Boston, 103.
Col Isoard, valley of, devastated, 242.
Commerce, modern, on what dependent, 60.
Como, lake of, proposed lowering of, 358.
Constance, lake of, 534.
Cork-oak tree, yield of, 311.
Corporations, social and political, influence of, 54.
Cosmical influences, 13.
Cotton, early cultivation of, 61;
can be raised by white labor, 381.
Crawley Sparrow Club, 90.
Currents, sea, strength of, 456;
in the Bosphorus, 457.
Cuyahoga river, 208.
Cypress tree, its beauty, 314.
Darien, Isthmus of, proposed canal across, 522;
conjectural effects of, 523.
Dead Sea, projected canals to, 524;
possible results of, 525.
causes producing, in New England, Africa, Arabia Petræa, 20-22;
man's action on, difficult to ascertain, 51;
deterioration, 71.
Coal mines, combustion of, 546.
Coal, sea, early use of, for fuel, 222;
increased use of, in Paris, 295.
Coast line, change of, from natural causes, 331;
subject to human guidance, 332.
Cochineal insect transferred to Spain, 105.
Cochituate Aqueduct, Boston, 103.
Col Isoard, valley of, devastated, 242.
Commerce, modern, on what dependent, 60.
Como, lake of, proposed lowering of, 358.
Constance, lake of, 534.
Cork-oak tree, yield of, 311.
Corporations, social and political, influence of, 54.
Cosmical influences, 13.
Cotton, early cultivation of, 61;
can be raised by white labor, 381.
Crawley Sparrow Club, 90.
Currents, sea, strength of, 456;
in the Bosphorus, 457.
Cuyahoga river, 208.
Cypress tree, its beauty, 314.
Darien, Isthmus of, proposed canal across, 522;
conjectural effects of, 523.
Dead Sea, projected canals to, 524;
possible results of, 525.
Page 539
Deer, numbers of, in United States; 82;
tame, injurious to trees, 130.
Denmark, peat mosses of, 22;
dunes of, 497;
extent and movement of, 498;
legislative protection of, 501, 504.
Desert, the, richness of local color, 445;
mirage in, 446.
Des Plaines river, 533.
Despotism a cause of physical decay, 5.
Dikes, recovery of land by, in the Netherlands, 335;
early usage and immense extent of, 336;
encouraged by the Spaniards, 337;
details of their construction and effect on the land gained, 340-345;
in Egypt, 413.
Dinornis, or moa, recent extirpation of, in New Zealand, 95.
Dodo, the, extirpation of, 95.
Domestic animals, action of, on vegetation, 79;
origin and transfer of, 82;
injurious to the forest growth, 130.
Don river, proposed diversion of, 531.
Draining a geographical element, 360;
superficial, its necessity in forest lands, 363;
effect on temperature, 364;
underground, ib.;
extensive use of, in England, 362;
affects the atmosphere, 364;
disturbs the equilibrium of river supply, 365;
by boring, 362;
in France, &c., 362;
Paris, 363.
Drance, Switzerland, glacier lake of, 403.
Dry land and water, relative extent of, 178.
Dwight, Dr., Travels in the United States, characterized, 52.
Earth, fertile, below the rock, 537;
tame, injurious to trees, 130.
Denmark, peat mosses of, 22;
dunes of, 497;
extent and movement of, 498;
legislative protection of, 501, 504.
Desert, the, richness of local color, 445;
mirage in, 446.
Des Plaines river, 533.
Despotism a cause of physical decay, 5.
Dikes, recovery of land by, in the Netherlands, 335;
early usage and immense extent of, 336;
encouraged by the Spaniards, 337;
details of their construction and effect on the land gained, 340-345;
in Egypt, 413.
Dinornis, or moa, recent extirpation of, in New Zealand, 95.
Dodo, the, extirpation of, 95.
Domestic animals, action of, on vegetation, 79;
origin and transfer of, 82;
injurious to the forest growth, 130.
Don river, proposed diversion of, 531.
Draining a geographical element, 360;
superficial, its necessity in forest lands, 363;
effect on temperature, 364;
underground, ib.;
extensive use of, in England, 362;
affects the atmosphere, 364;
disturbs the equilibrium of river supply, 365;
by boring, 362;
in France, &c., 362;
Paris, 363.
Drance, Switzerland, glacier lake of, 403.
Dry land and water, relative extent of, 178.
Dwight, Dr., Travels in the United States, characterized, 52.
Earth, fertile, below the rock, 537;
Page 540
transported to cover rocky surfaces, 537.
Earthquakes, effects of, 542;
causes and possible prevention of, 543;
of Lisbon, 544.
Earthworm, utility of, in agriculture, 100;
multiplication of, in New England, 101.
Egypt, catacombs, 70;
papyrus or water lily, 70;
poisonous snakes of, 112;
supposed increase of rain in, 190;
productiveness of, 230;
necessity and extent of irrigation in, 368, 373;
cultivated soil of, 372, 374;
population of, 374;
amount of water used for irrigation, 380;
saline deposits, 382;
artificial river courses of, 402;
cultivated area of, 412;
sands of, 458;
their prevalence and extent, 459;
source of, 461;
action on the Delta and cultivated land, 462;
effect of the diversion of the Nile on, 529;
refuse heaps near Cairo, 541.
Eland, the, preserved in Prussia, 86.
Elm, the Washington, Cambridge, 146.
Elsineur, artificial formation in harbor of, 539.
England, forest economy of, 221;
large extent of ornamental plantations, 222;
Forests of, described by Cæsar, 222;
private enterprise in sylviculture, 292;
sand dunes of, 507.
Enguerrand de Coucy, cruelty of, 281.
Erie Canal, the, influence on the fauna and flora of its region, 116;
lake, depth and level of, 532;
proposed canal from, 532.
Espy's theories of artificial rain, 547.
Etna, volcanic lava and dust, 131.
Earthquakes, effects of, 542;
causes and possible prevention of, 543;
of Lisbon, 544.
Earthworm, utility of, in agriculture, 100;
multiplication of, in New England, 101.
Egypt, catacombs, 70;
papyrus or water lily, 70;
poisonous snakes of, 112;
supposed increase of rain in, 190;
productiveness of, 230;
necessity and extent of irrigation in, 368, 373;
cultivated soil of, 372, 374;
population of, 374;
amount of water used for irrigation, 380;
saline deposits, 382;
artificial river courses of, 402;
cultivated area of, 412;
sands of, 458;
their prevalence and extent, 459;
source of, 461;
action on the Delta and cultivated land, 462;
effect of the diversion of the Nile on, 529;
refuse heaps near Cairo, 541.
Eland, the, preserved in Prussia, 86.
Elm, the Washington, Cambridge, 146.
Elsineur, artificial formation in harbor of, 539.
England, forest economy of, 221;
large extent of ornamental plantations, 222;
Forests of, described by Cæsar, 222;
private enterprise in sylviculture, 292;
sand dunes of, 507.
Enguerrand de Coucy, cruelty of, 281.
Erie Canal, the, influence on the fauna and flora of its region, 116;
lake, depth and level of, 532;
proposed canal from, 532.
Espy's theories of artificial rain, 547.
Etna, volcanic lava and dust, 131.
Page 541
Euphrates, sand plains in the valley of, 511.
Eye, cultivation of the, 11;
control of the limbs by, 12;
trained by the study of physical geography, 12.
Feudalism, pernicious influence of, 6.
Fir tree, the, its products, 311.
Fire weed, in burnt forests of the United States, 287.
Fish, destruction of, by man, 112, 114, 120, 122;
voracity of, 114;
introduction and breeding of foreign, 116;
naturalization of, 117;
inferiority of the artificially fattened, 121.
Fish, shell, extensive remains of, in United States, 117;
of Indian origin, 128.
Fish ponds of Catholic countries, 426.
Fontainebleau, forest of, 34, 130;
poaching in, 284;
its renovation, 316;
soil of, 513.
Food, ancient arts of preservation of, 18.
Forest, the, influence of, on the humidity of air, 162;
do. of earth, 165;
as organic, 166;
balance of conflicting influences in, 176;
influence on temperature, 178;
on precipitation, 181, 196;
in South America, 184;
the Canary Islands and Asia Minor, 185;
Peru, 188;
Palestine, Southern France, Scotland and Egypt, 189;
influence of, on humidity of soil, 196;
on springs, 197;
in Venezuela, 202;
New Granada, 204;
Switzerland and France, 205, 208;
United States, 207;
in winter, 210;
general consequences of its destruction, 214;
on the earth, springs, rivers, 215;
Eye, cultivation of the, 11;
control of the limbs by, 12;
trained by the study of physical geography, 12.
Feudalism, pernicious influence of, 6.
Fir tree, the, its products, 311.
Fire weed, in burnt forests of the United States, 287.
Fish, destruction of, by man, 112, 114, 120, 122;
voracity of, 114;
introduction and breeding of foreign, 116;
naturalization of, 117;
inferiority of the artificially fattened, 121.
Fish, shell, extensive remains of, in United States, 117;
of Indian origin, 128.
Fish ponds of Catholic countries, 426.
Fontainebleau, forest of, 34, 130;
poaching in, 284;
its renovation, 316;
soil of, 513.
Food, ancient arts of preservation of, 18.
Forest, the, influence of, on the humidity of air, 162;
do. of earth, 165;
as organic, 166;
balance of conflicting influences in, 176;
influence on temperature, 178;
on precipitation, 181, 196;
in South America, 184;
the Canary Islands and Asia Minor, 185;
Peru, 188;
Palestine, Southern France, Scotland and Egypt, 189;
influence of, on humidity of soil, 196;
on springs, 197;
in Venezuela, 202;
New Granada, 204;
Switzerland and France, 205, 208;
United States, 207;
in winter, 210;
general consequences of its destruction, 214;
on the earth, springs, rivers, 215;
Page 542
literature of, in France, 217;
Germany, 218;
Italy, 218;
England, 221;
influence of, on inundations, 223;
in North America, 225;
disputed effects of, in Europe, 228;
principal causes of its destruction, 270;
in British America, 271;
in Europe, 279;
royal forests, 280;
effects of the Revolution on, in France, 284;
utility of, for the preservation of smaller plants, 286, 290;
do. of birds, 291;
economic utility of, and necessity for its restoration, 292;
extent of, in Europe, 296;
proportion in different countries of, 300;
of the United States and Canada, 300;
economy of, 303;
management of, in France, 304;
European forests, all of artificial growth, 305;
artificial and natural, their respective advantages, 307;
American do., their peculiar characteristics, 313;
economic action of cattle on, 325;
duty of preserving, 327;
average revenue from, 327;
regulated by laws in France, 395.
See Trees, Woods.
Forests of North America, balance of geographical elements in, 27;
agency of quadrupeds and insects in, 32;
injury to, by insects, 33;
meteorological importance of, 139.
Forest laws, mediæval, character of, 217;
do. Jewish, 217;
severity of, in France and England, 280;
under Louis IX., 281;
of America, created by circumstances, 302.
France, forest literature and economy of, 217;
legislation on forests, 233;
— Southeastern, former physical state of, 237;
altered condition of, 239;
royal forests of, and forest laws, 280;
extent of, in, 296;
ancient lakes of, 357;
inundations of 1856 in, 393;
remedies against inundations in, 395;
Germany, 218;
Italy, 218;
England, 221;
influence of, on inundations, 223;
in North America, 225;
disputed effects of, in Europe, 228;
principal causes of its destruction, 270;
in British America, 271;
in Europe, 279;
royal forests, 280;
effects of the Revolution on, in France, 284;
utility of, for the preservation of smaller plants, 286, 290;
do. of birds, 291;
economic utility of, and necessity for its restoration, 292;
extent of, in Europe, 296;
proportion in different countries of, 300;
of the United States and Canada, 300;
economy of, 303;
management of, in France, 304;
European forests, all of artificial growth, 305;
artificial and natural, their respective advantages, 307;
American do., their peculiar characteristics, 313;
economic action of cattle on, 325;
duty of preserving, 327;
average revenue from, 327;
regulated by laws in France, 395.
See Trees, Woods.
Forests of North America, balance of geographical elements in, 27;
agency of quadrupeds and insects in, 32;
injury to, by insects, 33;
meteorological importance of, 139.
Forest laws, mediæval, character of, 217;
do. Jewish, 217;
severity of, in France and England, 280;
under Louis IX., 281;
of America, created by circumstances, 302.
France, forest literature and economy of, 217;
legislation on forests, 233;
— Southeastern, former physical state of, 237;
altered condition of, 239;
royal forests of, and forest laws, 280;
extent of, in, 296;
ancient lakes of, 357;
inundations of 1856 in, 393;
remedies against inundations in, 395;
Page 543
sand dunes of Western, 485;
encroachments of the sea on, 494.
French peasantry, described by La Bruyere, 6;
do. Arthur Young, 7;
of Chambord, 283.
Friesland, sand dunes of, 489.
Fucinus Lake (Lago di Celano), drainage of, by the Romans, 354;
moderns, 355.
Game Laws, effect on the numbers of birds in France, 91;
in England and Italy, 92;
severity of, in France, 283;
unable to stop poaching, 284.
Ganges, valley of the, 548.
Gascony, coast sands of, 453;
dunes of, 496;
extent and advance of, 497;
fixing and reclaiming of, 504;
Landes of, 511;
their reclamation, 512.
Geological influences, 13.
Geographers, new school of, 8.
Geographical influence of changes produced by man, 352.
Geography, modern, improved form of, 57.
German Ocean, sands of, 454, 457.
Germany, extent of forests in, 299.
Glacier lakes in Switzerland, 403.
Goat, the Cashmere or Thibet, 83.
Gold fish, the migration from China, 116.
Goldau, Switzerland, destruction of, 268.
Grape disease, its economic effect in France, Italy, Sicily, 72.
Grasshopper, the rapid increase in America, 291.
encroachments of the sea on, 494.
French peasantry, described by La Bruyere, 6;
do. Arthur Young, 7;
of Chambord, 283.
Friesland, sand dunes of, 489.
Fucinus Lake (Lago di Celano), drainage of, by the Romans, 354;
moderns, 355.
Game Laws, effect on the numbers of birds in France, 91;
in England and Italy, 92;
severity of, in France, 283;
unable to stop poaching, 284.
Ganges, valley of the, 548.
Gascony, coast sands of, 453;
dunes of, 496;
extent and advance of, 497;
fixing and reclaiming of, 504;
Landes of, 511;
their reclamation, 512.
Geological influences, 13.
Geographers, new school of, 8.
Geographical influence of changes produced by man, 352.
Geography, modern, improved form of, 57.
German Ocean, sands of, 454, 457.
Germany, extent of forests in, 299.
Glacier lakes in Switzerland, 403.
Goat, the Cashmere or Thibet, 83.
Gold fish, the migration from China, 116.
Goldau, Switzerland, destruction of, 268.
Grape disease, its economic effect in France, Italy, Sicily, 72.
Grasshopper, the rapid increase in America, 291.
Page 544
Gravedigger beetle, the, 107.
Greece, proposed maritime canals in, through the Corinthian Isthmus, 526;
Mount Athos, 527;
subterranean waters of, 536.
Gulls, sea, habits of, 98.
Gulf stream, the, 523.
Gunpowder chiefly used for industrial purposes, 335.
Haarlem Lake, origin and extent of, 346, 347;
reasons for draining it, 348;
means employed, 349;
successful results, 350.
Hauran, the productions of, its soil, 74.
Heilbronn, springs at, 207.
Herring fishery, produce of, 120.
Hessian fly, introduction of in the United States, 104.
Honey bee, the wild, New England, legal usage, 302.
Humid air, movement of, 183.
Hunter in New England, exploits of, 82.
Ibex, the Alpine, 86.
India, saline efflorescence of its soil, 382;
natural connection of rivers in, 401.
Insects, injurious to vegetable life, 33;
utility of, 99;
agency in the fertilization of orchids, 102;
mass of their exuviæ in South America, 102;
introduction of injurious species, 104, 106;
ravages of, 105;
tenacity of life in, 106;
the carnivorous, useful to man, 107;
destruction of, by fish, 108;
abundance of, in Northern Europe, 108;
destruction of, by birds, 109;
Greece, proposed maritime canals in, through the Corinthian Isthmus, 526;
Mount Athos, 527;
subterranean waters of, 536.
Gulls, sea, habits of, 98.
Gulf stream, the, 523.
Gunpowder chiefly used for industrial purposes, 335.
Haarlem Lake, origin and extent of, 346, 347;
reasons for draining it, 348;
means employed, 349;
successful results, 350.
Hauran, the productions of, its soil, 74.
Heilbronn, springs at, 207.
Herring fishery, produce of, 120.
Hessian fly, introduction of in the United States, 104.
Honey bee, the wild, New England, legal usage, 302.
Humid air, movement of, 183.
Hunter in New England, exploits of, 82.
Ibex, the Alpine, 86.
India, saline efflorescence of its soil, 382;
natural connection of rivers in, 401.
Insects, injurious to vegetable life, 33;
utility of, 99;
agency in the fertilization of orchids, 102;
mass of their exuviæ in South America, 102;
introduction of injurious species, 104, 106;
ravages of, 105;
tenacity of life in, 106;
the carnivorous, useful to man, 107;
destruction of, by fish, 108;
abundance of, in Northern Europe, 108;
destruction of, by birds, 109;
Page 545
do. quadrupeds, 110;
do. reptiles, 110;
do not multiply in the forest, 291;
confine themselves to dead trees, 322.
Inundations, influence of the forest on, 223;
of the German Ocean, 334;
means for obviating, 384;
of 1856 in France, 393;
remedies against, 395;
legislative regulation of the woodlands in France for prevention of, 396;
proposed basins of reception, 398;
do. in Peru and Spain, 400;
Rozet's plan for diminishing, 406.
Irrigation, remote date of in ancient nations, 366;
among Mexicans and Peruvians, 366;
its necessity in hot climates, 367;
in Europe, 367;
in Palestine, 368;
in Idumæa, 370;
Egypt, 371, 373;
quantity of water so applied, 376, 377;
extent of lands irrigated, 396;
effects of, 378;
on river supply, 380;
on human health, 381;
saline deposits from, in India and Egypt, 382;
effect of, on vegetable crops, 378;
on the soil, 379;
economic evils of, 379.
Islands, floating, in Holland and South America, 349, 351.
Ijssel river, Holland, 535.
Italy, effects of the denudation of its forests, 220;
political condition adverse to their preservation, 219;
beauty of its winter scenery, 314;
extent of irrigation in, 368;
atmospheric phenomena of Northern, 368.
Jupiter, satellites of, visible to the eye, 12.
Jutland, effects of felling the woods in, 150;
destruction of forests in, 279;
encroachments of the sea on, 491.
do. reptiles, 110;
do not multiply in the forest, 291;
confine themselves to dead trees, 322.
Inundations, influence of the forest on, 223;
of the German Ocean, 334;
means for obviating, 384;
of 1856 in France, 393;
remedies against, 395;
legislative regulation of the woodlands in France for prevention of, 396;
proposed basins of reception, 398;
do. in Peru and Spain, 400;
Rozet's plan for diminishing, 406.
Irrigation, remote date of in ancient nations, 366;
among Mexicans and Peruvians, 366;
its necessity in hot climates, 367;
in Europe, 367;
in Palestine, 368;
in Idumæa, 370;
Egypt, 371, 373;
quantity of water so applied, 376, 377;
extent of lands irrigated, 396;
effects of, 378;
on river supply, 380;
on human health, 381;
saline deposits from, in India and Egypt, 382;
effect of, on vegetable crops, 378;
on the soil, 379;
economic evils of, 379.
Islands, floating, in Holland and South America, 349, 351.
Ijssel river, Holland, 535.
Italy, effects of the denudation of its forests, 220;
political condition adverse to their preservation, 219;
beauty of its winter scenery, 314;
extent of irrigation in, 368;
atmospheric phenomena of Northern, 368.
Jupiter, satellites of, visible to the eye, 12.
Jutland, effects of felling the woods in, 150;
destruction of forests in, 279;
encroachments of the sea on, 491.
Page 546
Kander river, Switzerland, artificial course of, 403.
Karst, the subterranean waters of, 536.
Kjökkenmöddinger in Denmark, 16;
their extent, 540.
Kohl, J. G., "the Herodotus of modern Europe," 340;
on dune sand, 475.
Labruguière, commune of, 208.
Læstadius, account of the Swedish Laplanders, 96.
Lakes, draining of, by steam hydraulic engines, 346;
natural process of filling up by aquatic vegetation, 349;
lowering of, in ancient and modern times, 353;
in Italy, 354;
in Switzerland, 356;
inconvenient consequences of, 356;
mountain, their disappearance, 357.
Landscape beauty, insensibility of the ancients to, 2;
of the oasis and the desert, 445.
Lava currents, diversion of their course, 544;
from Vesuvius, phenomena of, 545;
heat emitted by, 545.
Life, balance of animal and vegetable, 103.
Liimfjord, the, irruption of the sea into, 491;
aquatic vegetation of, 492;
original state of, 519.
Lion, an inhabitant of Europe, 85.
Lisbon, earthquake of, 544.
Locust, the, does not multiply in woods, 296;
tree and insect, 32.
Lombardy, statistics of irrigation in, 376.
Louis IX., of France, clemency of, 282.
Lower Alps, department of, ravages of torrents in, 246.
Lumber trade of Quebec, 271;
Karst, the subterranean waters of, 536.
Kjökkenmöddinger in Denmark, 16;
their extent, 540.
Kohl, J. G., "the Herodotus of modern Europe," 340;
on dune sand, 475.
Labruguière, commune of, 208.
Læstadius, account of the Swedish Laplanders, 96.
Lakes, draining of, by steam hydraulic engines, 346;
natural process of filling up by aquatic vegetation, 349;
lowering of, in ancient and modern times, 353;
in Italy, 354;
in Switzerland, 356;
inconvenient consequences of, 356;
mountain, their disappearance, 357.
Landscape beauty, insensibility of the ancients to, 2;
of the oasis and the desert, 445.
Lava currents, diversion of their course, 544;
from Vesuvius, phenomena of, 545;
heat emitted by, 545.
Life, balance of animal and vegetable, 103.
Liimfjord, the, irruption of the sea into, 491;
aquatic vegetation of, 492;
original state of, 519.
Lion, an inhabitant of Europe, 85.
Lisbon, earthquake of, 544.
Locust, the, does not multiply in woods, 296;
tree and insect, 32.
Lombardy, statistics of irrigation in, 376.
Louis IX., of France, clemency of, 282.
Lower Alps, department of, ravages of torrents in, 246.
Lumber trade of Quebec, 271;
Page 547
of United States, 1850-'60, 301.
Lungern, lake of, lowering of, 356.
Madagascar, gigantic bird of, 96;
the ai-ai of, 110.
Madder, early cultivation of, in Europe, 20.
Madeira, named from its forests, 129.
Maize, early cultivation of, law of its acclimation, 19;
native country of, 73.
Malta, transported soil of, 538;
salt works at, 540.
Man, reaction of, on nature, 8;
insufficiency of data, 9;
geographical influence of, 13;
physical revolutions wrought by, 14;
unpremeditated results of conscious action, 15;
ancient relics of, in old geological formations, 16;
mechanical effects of, on the earth's surface, 25;
destructiveness of, 35;
in animal life and inorganic nature, 36-39;
character of his action compared with that of brutes, 42;
subversive of the balance of nature, 43;
sometimes exercised for good, 44;
present limits to, 45;
transfer of vegetable life by, 59;
remains of, 76;
contemporary with the mammoth, 77;
agency in the extermination of birds, 96;
do. introduction of species, 98;
increase of insect life, 104;
introduction of new forms of do. by, 105;
destruction of fish by, 112, 120, 122;
extirpation of aquatic animals by, 119;
possible control of minute organisms, 125;
his first physical conquest, 135;
his action on land and the waters, 330;
possible geographical changes by, 517;
incidental effects of his action, 539;
illimitable and ever enduring do., 548.
Maremme of Tuscany, ancient and mediæval state of, 425;
extent of, 427;
inhabitants, 428;
Lungern, lake of, lowering of, 356.
Madagascar, gigantic bird of, 96;
the ai-ai of, 110.
Madder, early cultivation of, in Europe, 20.
Madeira, named from its forests, 129.
Maize, early cultivation of, law of its acclimation, 19;
native country of, 73.
Malta, transported soil of, 538;
salt works at, 540.
Man, reaction of, on nature, 8;
insufficiency of data, 9;
geographical influence of, 13;
physical revolutions wrought by, 14;
unpremeditated results of conscious action, 15;
ancient relics of, in old geological formations, 16;
mechanical effects of, on the earth's surface, 25;
destructiveness of, 35;
in animal life and inorganic nature, 36-39;
character of his action compared with that of brutes, 42;
subversive of the balance of nature, 43;
sometimes exercised for good, 44;
present limits to, 45;
transfer of vegetable life by, 59;
remains of, 76;
contemporary with the mammoth, 77;
agency in the extermination of birds, 96;
do. introduction of species, 98;
increase of insect life, 104;
introduction of new forms of do. by, 105;
destruction of fish by, 112, 120, 122;
extirpation of aquatic animals by, 119;
possible control of minute organisms, 125;
his first physical conquest, 135;
his action on land and the waters, 330;
possible geographical changes by, 517;
incidental effects of his action, 539;
illimitable and ever enduring do., 548.
Maremme of Tuscany, ancient and mediæval state of, 425;
extent of, 427;
inhabitants, 428;
Page 548
improvement of, 429;
sedimentary deposits of, 425, 430.
Marine isthmuses, cutting of, 517;
its difficulties, 518;
sometimes done by nature, 519.
Marmato in Popayan, 205.
Marshes, climatic effects of draining, 358;
insalubrity of mixture of fresh and salt water in, 417.
Mechanic arts, illustration of their mutual interdependence, 307.
Medanos of the South American desert, 482.
Mediterranean Sea, tides of, 425;
sand dunes of, 467;
poor in organic life, 520.
Mella, the river, Italy, 248.
Meteorology, uncertainty and late rise of, 16, 22;
varying nomenclature of, 23;
precipitation and evaporation, 24.
Michigan, lake, sand dunes of, 467;
originally wooded, 487;
proposed diversion of its waters, 532.
Mining excavations, effects of, 545.
Minute organisms, their offices, 123;
universal diffusion and products of, 124, 127;
possible control of their agency by man, 125;
the coral insect, 125;
the diatomaceæ, 126.
Miramichi, great fire of, 28.
Mistral in France, 153.
Mississippi river, "cut offs" and their effect, 415;
precipitation in the valley of, 436;
projected canal to, 533.
Mountain slides, their cause, 265, 268;
their frequency in the Alps, 267.
Mountainous countries, their liability to physical degradation, 50.
sedimentary deposits of, 425, 430.
Marine isthmuses, cutting of, 517;
its difficulties, 518;
sometimes done by nature, 519.
Marmato in Popayan, 205.
Marshes, climatic effects of draining, 358;
insalubrity of mixture of fresh and salt water in, 417.
Mechanic arts, illustration of their mutual interdependence, 307.
Medanos of the South American desert, 482.
Mediterranean Sea, tides of, 425;
sand dunes of, 467;
poor in organic life, 520.
Mella, the river, Italy, 248.
Meteorology, uncertainty and late rise of, 16, 22;
varying nomenclature of, 23;
precipitation and evaporation, 24.
Michigan, lake, sand dunes of, 467;
originally wooded, 487;
proposed diversion of its waters, 532.
Mining excavations, effects of, 545.
Minute organisms, their offices, 123;
universal diffusion and products of, 124, 127;
possible control of their agency by man, 125;
the coral insect, 125;
the diatomaceæ, 126.
Miramichi, great fire of, 28.
Mistral in France, 153.
Mississippi river, "cut offs" and their effect, 415;
precipitation in the valley of, 436;
projected canal to, 533.
Mountain slides, their cause, 265, 268;
their frequency in the Alps, 267.
Mountainous countries, their liability to physical degradation, 50.
Page 549
Monte Testaccio, Rome, 541.
Moose deer, the American, rapid multiplication of, 130.
Mushrooms, poisonous, how to render harmless, 286.
Natural forces, accumulation of, 46;
resistance to, 542.
Nature, man's reaction on, 8;
observation of, 10;
stability of, 27, 34;
restoration of disturbed harmonies of, 35;
nothing small in, 548.
Naturalists, enthusiasm of, 99.
Netherlands, ancient inundations of, 334;
recovery of land by diking, 334;
the practice derived from the Romans, 335;
extent of land gained from the sea, 336;
do. lost by incursions of do., 337;
character of lands gained, 338;
natural process of recovery, 339;
grandeur of the dike system of, 340;
method of their construction in, 341;
modes of protection, 343;
various uses of, 343;
effect on the level of the land, 344;
drainage of do., 345;
primitive condition of, 351;
effects on the social, moral, and economic interests of the people of, 351;
sand dunes of, 486;
encroachments of the sea on, 494;
artificial dunes in, 499;
protection of dunes in, 500;
removal of do., 509.
Nile, the river, valley of, 374;
its ancient state, 375;
inundations of, 385;
water delivery of, 387;
artificial mouths of, 402;
consequences of diking, 410, 413;
richness of its deposits, 411;
extent of do., 412;
mud banks caused by its deposits, 433;
sand dunes at its mouths, 468;
Moose deer, the American, rapid multiplication of, 130.
Mushrooms, poisonous, how to render harmless, 286.
Natural forces, accumulation of, 46;
resistance to, 542.
Nature, man's reaction on, 8;
observation of, 10;
stability of, 27, 34;
restoration of disturbed harmonies of, 35;
nothing small in, 548.
Naturalists, enthusiasm of, 99.
Netherlands, ancient inundations of, 334;
recovery of land by diking, 334;
the practice derived from the Romans, 335;
extent of land gained from the sea, 336;
do. lost by incursions of do., 337;
character of lands gained, 338;
natural process of recovery, 339;
grandeur of the dike system of, 340;
method of their construction in, 341;
modes of protection, 343;
various uses of, 343;
effect on the level of the land, 344;
drainage of do., 345;
primitive condition of, 351;
effects on the social, moral, and economic interests of the people of, 351;
sand dunes of, 486;
encroachments of the sea on, 494;
artificial dunes in, 499;
protection of dunes in, 500;
removal of do., 509.
Nile, the river, valley of, 374;
its ancient state, 375;
inundations of, 385;
water delivery of, 387;
artificial mouths of, 402;
consequences of diking, 410, 413;
richness of its deposits, 411;
extent of do., 412;
mud banks caused by its deposits, 433;
sand dunes at its mouths, 468;
Page 550
conduits for irrigation, 521;
proposed diversion of, 528;
not impossible, 529;
effects of, 530;
ceramic banks of, 541.
Northmen in New England, 60.
Nubians, Nile boats of the, 17.
Numbers, the frequent error in too definite statements of, 260;
oriental and Italian usage of, 261.
Oak, the English, early uses in the arts, 223;
"openings" of North America, 136.
Ohio, mounds of, 18;
remains of a primitive people in, 135, 138;
apple trees of, 22.
Old World, former populousness of, 4;
physical decay of, 3;
present desolation of, 5;
its causes, 5;
ancient climate of, 19;
physical restoration of, 47.
Olive tree, the wild, 74;
importance of, 312.
Orange tree known to the ancients, 64;
the wild, 74.
Orchids, fertilization of, by insects, 102.
Organic life embraced in modern geography, 57;
its geological agency, 75;
geographical importance of, 7;
bones and relics of, human and animal, 76.
Ostrich, the, diminution of its numbers, 97.
Ottaquechee river, Vermont, transporting power of, 253.
Otter, the American, voracity of, 120.
Oxen, agricultural uses of, in United States, 80.
Oyster, the, transplantation of, 118.
proposed diversion of, 528;
not impossible, 529;
effects of, 530;
ceramic banks of, 541.
Northmen in New England, 60.
Nubians, Nile boats of the, 17.
Numbers, the frequent error in too definite statements of, 260;
oriental and Italian usage of, 261.
Oak, the English, early uses in the arts, 223;
"openings" of North America, 136.
Ohio, mounds of, 18;
remains of a primitive people in, 135, 138;
apple trees of, 22.
Old World, former populousness of, 4;
physical decay of, 3;
present desolation of, 5;
its causes, 5;
ancient climate of, 19;
physical restoration of, 47.
Olive tree, the wild, 74;
importance of, 312.
Orange tree known to the ancients, 64;
the wild, 74.
Orchids, fertilization of, by insects, 102.
Organic life embraced in modern geography, 57;
its geological agency, 75;
geographical importance of, 7;
bones and relics of, human and animal, 76.
Ostrich, the, diminution of its numbers, 97.
Ottaquechee river, Vermont, transporting power of, 253.
Otter, the American, voracity of, 120.
Oxen, agricultural uses of, in United States, 80.
Oyster, the, transplantation of, 118.
Page 551
Palestine, ancient terrace culture and irrigation of, 369;
disastrous effects of its neglect, 370.
Palissy, Bernard, character of, 218;
plan for artificial springs, 447.
Paragrandini of Lombardy, 141.
Paramelle, the Abbé, on fountains, 437.
Peat beds, accidental burning of, 546;
— mosses of Denmark, 32.
Pecora, river of the Maremma, its deposits, 425.
Peru, ancient progress in the arts, 366;
basins of reception in, 400.
Petra, in Idumæa, ancient irrigation at, 370.
Phosphorescence of the sea unknown to the ancients, 114.
Physical decay of the earth's surface, 3;
its causes, 5;
arrest of, in new countries, 48;
forms and formations predisposing to, 49.
Physical geography, study of recommended, 12;
restoration of the earth, 8;
importance and possibility of, 26;
of disturbed harmonies, 35;
of the Old World, 47.
Pine, the American, former ordinary dimensions of, 275;
how affected by the accidents of its growth, 306;
the maritime, on dune sands in France, 506;
the pitch, hardihood of, 273;
umbrella, the, most elegant of trees, 309, 313;
the white, rapidity of its growth, 274.
Pinus cembra of Switzerland, 309.
Pisciculture, its valuable results, 118.
Plants, cultivated, uncertain identity of ancient and modern, 19;
do. of wild and domestic species, 73;
changes of habit by domestication, 19;
geographical influence of, 58;
disastrous effects of its neglect, 370.
Palissy, Bernard, character of, 218;
plan for artificial springs, 447.
Paragrandini of Lombardy, 141.
Paramelle, the Abbé, on fountains, 437.
Peat beds, accidental burning of, 546;
— mosses of Denmark, 32.
Pecora, river of the Maremma, its deposits, 425.
Peru, ancient progress in the arts, 366;
basins of reception in, 400.
Petra, in Idumæa, ancient irrigation at, 370.
Phosphorescence of the sea unknown to the ancients, 114.
Physical decay of the earth's surface, 3;
its causes, 5;
arrest of, in new countries, 48;
forms and formations predisposing to, 49.
Physical geography, study of recommended, 12;
restoration of the earth, 8;
importance and possibility of, 26;
of disturbed harmonies, 35;
of the Old World, 47.
Pine, the American, former ordinary dimensions of, 275;
how affected by the accidents of its growth, 306;
the maritime, on dune sands in France, 506;
the pitch, hardihood of, 273;
umbrella, the, most elegant of trees, 309, 313;
the white, rapidity of its growth, 274.
Pinus cembra of Switzerland, 309.
Pisciculture, its valuable results, 118.
Plants, cultivated, uncertain identity of ancient and modern, 19;
do. of wild and domestic species, 73;
changes of habit by domestication, 19;
geographical influence of, 58;
Page 552
foreign, grown in United States, 61;
American, grown in Europe, 63;
modes of introduction, 64;
accidental do., 66;
power of accommodation of, 65;
how affected by transfer, 68;
tenacity of life in wild species, 69;
extirpation of, 70;
domestic origin of, 72;
species employed for protection of sand dunes, 500.
Pliny, the elder, theory of springs, 198, 216.
Po, river, ancient state of its basin, 255;
modern changes, 256;
its floods, tributaries, and deposits, 256-261, 405;
embankments of, 385, 404;
sediment of, 410;
age and consequences of its embankments, 411;
mean delivery of, 412;
salti of, 415.
Poland, sand plains of, 514.
Poplar, the Lombardy, 68;
characterized, 313.
Potato, native country of, 73.
Prairies, conjectural origin of, 134.
Provence, physical structure of, 237;
ancient state of, 238;
destructive action of torrents on, 236;
Alps of, 245.
Prussia, sand dunes of, 485;
drifting of, 498;
measures for reclaiming of, 505.
Quadrupeds, number in United States, 79;
extirpation of, 84.
Quebec, high tides of, 271;
lumber trade of, 272.
Railways, scientific uses of, 53.
American, grown in Europe, 63;
modes of introduction, 64;
accidental do., 66;
power of accommodation of, 65;
how affected by transfer, 68;
tenacity of life in wild species, 69;
extirpation of, 70;
domestic origin of, 72;
species employed for protection of sand dunes, 500.
Pliny, the elder, theory of springs, 198, 216.
Po, river, ancient state of its basin, 255;
modern changes, 256;
its floods, tributaries, and deposits, 256-261, 405;
embankments of, 385, 404;
sediment of, 410;
age and consequences of its embankments, 411;
mean delivery of, 412;
salti of, 415.
Poland, sand plains of, 514.
Poplar, the Lombardy, 68;
characterized, 313.
Potato, native country of, 73.
Prairies, conjectural origin of, 134.
Provence, physical structure of, 237;
ancient state of, 238;
destructive action of torrents on, 236;
Alps of, 245.
Prussia, sand dunes of, 485;
drifting of, 498;
measures for reclaiming of, 505.
Quadrupeds, number in United States, 79;
extirpation of, 84.
Quebec, high tides of, 271;
lumber trade of, 272.
Railways, scientific uses of, 53.
Page 553
Rain water, its absorption and infiltration, 438, 439;
economizing its precipitation, 449.
Ravenna, cathedral of, 60;
pine woods of, 150.
Red Sea, richness of, in organic life, 320;
diversion of the Nile to, its effects, 530.
Reindeer, the, 83.
Reservoirs, geographic and climatic effects of, 258.
Reventlov's organization of dune economy in Denmark, 504;
a benefactor to his race, 515.
Rhine, river, proposed diversion of, 533.
Rice, cultivation of, 381.
Rivers, transporting power of, 252;
in Vermont, 253;
their origin, 262;
injury to their banks by lumbermen, 277;
conditions of their rise and fall, 278;
mutual action of rivers and valleys, 408;
effect of obstructions in, 409;
subterranean course of, 409;
confluences of, effect on the current below, 424;
sediment of, its extent, 547.
River beds, natural change of, 401;
artificial do. in Egypt, 402;
Italy and Switzerland, 403.
River deposits, 408;
of the Nile, 410;
the Po, 411;
the Tuscan rivers, 414.
River embankments, 384;
their use, 404;
disadvantages, 405;
transverse do., superiority of, 406;
effects of, 409.
River mouths, obstructions of, 430;
by sand banks, 431;
accelerated by man's influence, 432;
effect of tidal movements, 432.
economizing its precipitation, 449.
Ravenna, cathedral of, 60;
pine woods of, 150.
Red Sea, richness of, in organic life, 320;
diversion of the Nile to, its effects, 530.
Reindeer, the, 83.
Reservoirs, geographic and climatic effects of, 258.
Reventlov's organization of dune economy in Denmark, 504;
a benefactor to his race, 515.
Rhine, river, proposed diversion of, 533.
Rice, cultivation of, 381.
Rivers, transporting power of, 252;
in Vermont, 253;
their origin, 262;
injury to their banks by lumbermen, 277;
conditions of their rise and fall, 278;
mutual action of rivers and valleys, 408;
effect of obstructions in, 409;
subterranean course of, 409;
confluences of, effect on the current below, 424;
sediment of, its extent, 547.
River beds, natural change of, 401;
artificial do. in Egypt, 402;
Italy and Switzerland, 403.
River deposits, 408;
of the Nile, 410;
the Po, 411;
the Tuscan rivers, 414.
River embankments, 384;
their use, 404;
disadvantages, 405;
transverse do., superiority of, 406;
effects of, 409.
River mouths, obstructions of, 430;
by sand banks, 431;
accelerated by man's influence, 432;
effect of tidal movements, 432.
Page 554
Robin, the American, voracity of, 88.
Rock generally permeable by water, 265.
Roman empire, natural advantages of its territory, 1;
increased by intelligent labor, 2;
physical decay of, 3;
present desolation, 4;
caused by its despotism and oppression, 5.
Rozet's plan for diminishing inundations, 406.
Rude tribes, continuity of arts among, 17;
commerce of, 18;
relations to organic life, 39;
and to nature, 41.
Russia, diminution of forests in, 298;
effects of, on rivers and lakes, 299;
sand drifts of the steppes of, 514;
attempts to reclaim them, 515.
Sacramento City, California, effect of river dike at, 405.
Sand, its composition and origin, 452;
action of rivers, 453;
ancient deposits of, 454, 456;
amount of, carried to the Mediterranean, 455;
of Egypt, 458, 461;
movement of, by the wind, 459;
drifts of, from the sea, 461;
dangers of accumulation of, 463;
two forms of deposit, 463;
drifting of dune, 495.
Sand banks, aquatic, 468;
movement of, 469;
connect themselves with the coast, 490.
Sand dunes, how formed, 464;
utilization of, 465;
inland, of the South American desert, 482;
their peculiarities, 483;
age, character, and permanence of, 484;
naturally wooded, 486;
not noticed by ancient writers, 487;
management of, 488;
coast, sources of supply, 465;
Rock generally permeable by water, 265.
Roman empire, natural advantages of its territory, 1;
increased by intelligent labor, 2;
physical decay of, 3;
present desolation, 4;
caused by its despotism and oppression, 5.
Rozet's plan for diminishing inundations, 406.
Rude tribes, continuity of arts among, 17;
commerce of, 18;
relations to organic life, 39;
and to nature, 41.
Russia, diminution of forests in, 298;
effects of, on rivers and lakes, 299;
sand drifts of the steppes of, 514;
attempts to reclaim them, 515.
Sacramento City, California, effect of river dike at, 405.
Sand, its composition and origin, 452;
action of rivers, 453;
ancient deposits of, 454, 456;
amount of, carried to the Mediterranean, 455;
of Egypt, 458, 461;
movement of, by the wind, 459;
drifts of, from the sea, 461;
dangers of accumulation of, 463;
two forms of deposit, 463;
drifting of dune, 495.
Sand banks, aquatic, 468;
movement of, 469;
connect themselves with the coast, 490.
Sand dunes, how formed, 464;
utilization of, 465;
inland, of the South American desert, 482;
their peculiarities, 483;
age, character, and permanence of, 484;
naturally wooded, 486;
not noticed by ancient writers, 487;
management of, 488;
coast, sources of supply, 465;
Page 555
law of their formation, 466, 471, 483;
of the Mediterranean, 467;
of Lake Michigan, 467;
of the Nile mouths, 468;
of America, 469;
of Western Europe, 470;
literature of, 471;
height of, 472;
humidity of, 473;
of Cape Cod, 487;
character of their sand, 474, 481;
concretion within, 476;
interior structure of, 477;
general form of, 478;
geological importance of, 479;
composition of sandstone, 481;
as barriers against the sea, 489;
in Western Europe, 490;
extent of, 507;
of Gascony, 496;
of Denmark, 497;
of Prussia, 497;
artificial formation of, in Holland, 499;
protection of, 500;
by vegetation, 501;
trees adapted to, 505;
removal of, 509.
Sand-dune vineyard of Cap Breton, 508.
Sand plains, mode of deposit, 464;
constituent parts, 464;
inland, of Europe, 509;
landes of Gascony, 511;
Belgium, 513;
Eastern Europe, 513;
advantages of reclaiming, 515;
private and public enterprise, 516.
Sand springs, 511.
Sandal wood extirpated in Juan Fernandez, 130.
Saros, projected canal of, 527.
Sawmills, action of their machinery more rapid by night, 278.
Schelk, the extirpation of, 85.
Schleswig-Holstein, encroachments of the sea on, 493.
of the Mediterranean, 467;
of Lake Michigan, 467;
of the Nile mouths, 468;
of America, 469;
of Western Europe, 470;
literature of, 471;
height of, 472;
humidity of, 473;
of Cape Cod, 487;
character of their sand, 474, 481;
concretion within, 476;
interior structure of, 477;
general form of, 478;
geological importance of, 479;
composition of sandstone, 481;
as barriers against the sea, 489;
in Western Europe, 490;
extent of, 507;
of Gascony, 496;
of Denmark, 497;
of Prussia, 497;
artificial formation of, in Holland, 499;
protection of, 500;
by vegetation, 501;
trees adapted to, 505;
removal of, 509.
Sand-dune vineyard of Cap Breton, 508.
Sand plains, mode of deposit, 464;
constituent parts, 464;
inland, of Europe, 509;
landes of Gascony, 511;
Belgium, 513;
Eastern Europe, 513;
advantages of reclaiming, 515;
private and public enterprise, 516.
Sand springs, 511.
Sandal wood extirpated in Juan Fernandez, 130.
Saros, projected canal of, 527.
Sawmills, action of their machinery more rapid by night, 278.
Schelk, the extirpation of, 85.
Schleswig-Holstein, encroachments of the sea on, 493.
Page 556
Scientific observation, practical lessons of, 54-56.
Sea, the, exclusion of, by dikes, in Lincolnshire, 333;
encroachments of, 490;
coast, 491;
the Liimfjord, 491;
Schleswig-Holstein, 493;
Holland, 494;
France, 494.
Sea cow, Steller's, extirpation of, 119.
Seal, the, in Lake Champlain, 117;
voracity of, 120.
Seeds, vitality of, as preserved by the forest, 287, 289.
Seine river, ancient level of, 214;
affluents of, 435.
Ship building of the middle ages, Venice and Genoa, 218.
Siberia, ice ravine in, 158.
Sicily, stone weapons found in, 18;
sulphur mines of, 72;
olive oil crop of, 312.
Silkworm, introduction in South America, 105.
Sinai, Mt., rain torrent at, 441;
production of sand in peninsula of, 454;
garden of monastery at, 537.
Snakes, destructive to insects, 110;
tenacity of species, 111;
number of, in Palestine and Egypt, 111.
Snow, action of the woods on, 211;
experiments on, 212.
Soils, amount of thermoscopic action on various, 144;
mechanical effects of shaking in the Netherlands, 344;
effect of frost on, in United States, 344.
Solar heat, economic employment of, 47.
Solitary, the, extirpation of, 95.
Sea, the, exclusion of, by dikes, in Lincolnshire, 333;
encroachments of, 490;
coast, 491;
the Liimfjord, 491;
Schleswig-Holstein, 493;
Holland, 494;
France, 494.
Sea cow, Steller's, extirpation of, 119.
Seal, the, in Lake Champlain, 117;
voracity of, 120.
Seeds, vitality of, as preserved by the forest, 287, 289.
Seine river, ancient level of, 214;
affluents of, 435.
Ship building of the middle ages, Venice and Genoa, 218.
Siberia, ice ravine in, 158.
Sicily, stone weapons found in, 18;
sulphur mines of, 72;
olive oil crop of, 312.
Silkworm, introduction in South America, 105.
Sinai, Mt., rain torrent at, 441;
production of sand in peninsula of, 454;
garden of monastery at, 537.
Snakes, destructive to insects, 110;
tenacity of species, 111;
number of, in Palestine and Egypt, 111.
Snow, action of the woods on, 211;
experiments on, 212.
Soils, amount of thermoscopic action on various, 144;
mechanical effects of shaking in the Netherlands, 344;
effect of frost on, in United States, 344.
Solar heat, economic employment of, 47.
Solitary, the, extirpation of, 95.
Page 557
Sound, transmission of, in still air, 165.
Springs, artificial, proposed by Palissy, 447;
by Babinet, 448.
Spain, neglect of forest culture in, 279.
Squirrel, the, destructiveness of, in forests, 34;
of Boston, 121.
St. Helena, flora of, 65;
destruction of its forests, 130.
Staffordshire, phenomena of vegetation in, 288.
Starlings, habits of, in Piedmont, 111.
Stork, the, geographical range of, 93;
anecdote of a, 99.
Subterranean waters, their origin, 434;
sources of supply, 435;
reservoirs and currents of, 438;
diffusion of, in the soil, 439;
importance, 440;
of the Karst, 535;
of Greece, 536.
Suez canal, the, danger from sand drifts, 461;
effect on the Mediterranean and Red Sea basins, 520.
Sugar cane, culture of, 62.
Sugar-maple tree, produce of, 169.
Summer dikes of Holland, 342.
Sunflowers, effect of plantations of, 154.
Swallow, the, popular superstitions respecting, 418.
Switzerland, ancient lacustrine habitations of, 16, 70, 83.
Sylt Island, sand dunes of, 474;
encroachments of the sea on, 493.
Sylviculture, best manuals of practice of, 304;
when and how profitable, 305;
its methods, 315;
the taillis treatment, 315;
Springs, artificial, proposed by Palissy, 447;
by Babinet, 448.
Spain, neglect of forest culture in, 279.
Squirrel, the, destructiveness of, in forests, 34;
of Boston, 121.
St. Helena, flora of, 65;
destruction of its forests, 130.
Staffordshire, phenomena of vegetation in, 288.
Starlings, habits of, in Piedmont, 111.
Stork, the, geographical range of, 93;
anecdote of a, 99.
Subterranean waters, their origin, 434;
sources of supply, 435;
reservoirs and currents of, 438;
diffusion of, in the soil, 439;
importance, 440;
of the Karst, 535;
of Greece, 536.
Suez canal, the, danger from sand drifts, 461;
effect on the Mediterranean and Red Sea basins, 520.
Sugar cane, culture of, 62.
Sugar-maple tree, produce of, 169.
Summer dikes of Holland, 342.
Sunflowers, effect of plantations of, 154.
Swallow, the, popular superstitions respecting, 418.
Switzerland, ancient lacustrine habitations of, 16, 70, 83.
Sylt Island, sand dunes of, 474;
encroachments of the sea on, 493.
Sylviculture, best manuals of practice of, 304;
when and how profitable, 305;
its methods, 315;
the taillis treatment, 315;
Page 558
the futaie do., 317;
beneficial effects of irrigation, 319;
exclusion of animals, 321;
removal of leaves, &c., 322;
topping and trimming, 324.
Taguataga Lake, Chili, 355.
Tea plant, the, cultivated in America, 62.
Temperature, general law of, 52.
Teredo, the general diffusion of, 107.
Termite, or white ant, ravages of, 107.
Teverone, cascade of, Tivoli, 402.
Timber, general superiority of cultivated, 305;
slow decay of, in forest, 322.
Tobacco an American plant, 68;
introduction in Hungary, 67.
Tocat, Asia Minor, oak woods of, 186.
Tomato, the, introduction to New England, 19.
Torricelli, successful plan for draining the Val di Chiana, 421.
Torrents, destructive action of, 231;
means of prevention, 233;
ravages of, in Southeastern France, 237;
Provence, 239;
Upper Alps, 240;
Lower Alps, 246;
action of, in elevating the beds of mainland streams, 249;
in excavating ravines, 250;
transporting power of, 251;
signs of, extinguished, 263;
crushing force of, 392.
Trees, as organisms, specific temperature of, 156;
moisture given out by, 158;
total influence on temperature, 159;
absorption of water by, 166;
flow of sap, 169;
absorption of moisture by foliage of, 172;
exhalation of do., 174;
beneficial effects of irrigation, 319;
exclusion of animals, 321;
removal of leaves, &c., 322;
topping and trimming, 324.
Taguataga Lake, Chili, 355.
Tea plant, the, cultivated in America, 62.
Temperature, general law of, 52.
Teredo, the general diffusion of, 107.
Termite, or white ant, ravages of, 107.
Teverone, cascade of, Tivoli, 402.
Timber, general superiority of cultivated, 305;
slow decay of, in forest, 322.
Tobacco an American plant, 68;
introduction in Hungary, 67.
Tocat, Asia Minor, oak woods of, 186.
Tomato, the, introduction to New England, 19.
Torricelli, successful plan for draining the Val di Chiana, 421.
Torrents, destructive action of, 231;
means of prevention, 233;
ravages of, in Southeastern France, 237;
Provence, 239;
Upper Alps, 240;
Lower Alps, 246;
action of, in elevating the beds of mainland streams, 249;
in excavating ravines, 250;
transporting power of, 251;
signs of, extinguished, 263;
crushing force of, 392.
Trees, as organisms, specific temperature of, 156;
moisture given out by, 158;
total influence on temperature, 159;
absorption of water by, 166;
flow of sap, 169;
absorption of moisture by foliage of, 172;
exhalation of do., 174;
Page 559
consequent refrigeration, 175;
amount of ligneous products of, 173;
protection against avalanches afforded by, 269;
power of resisting the action of fire, 273;
American forest trees, 274;
their dimensions, 275;
change in relative proportions of height and diameter, 276;
comparative longevity of, 277;
European and American compared, 308;
species more numerous in America, 309;
Spenser's catalogue of, 308;
interchange of European and American species, 310;
species of Southern Europe and their extent, 312;
natural order of succession in, 323.
See Forest, Woods.
Trieste, proposed supply of water to, 536.
Trout, the American, 115, 117, 121.
Tuscany, rivers of, their deposits, 414;
physical restoration in, 416;
improvements in Val di Chiana, 417;
do. in the Maremma, 424.
Tyrolese rivers, elevation of their beds, 249.
Ubate, lakes of, New Granada, 204.
Undulation of water, 456.
United States, foreign plants grown in, 61;
weight of annual harvest in, 62;
number of quadrupeds in, 79;
of birds, 86;
effect of felling woods on its climate, 180;
forests of, 300;
instability of life in, 328.
Upper Alps, department of, ravages of torrents in, 240.
Urus, or auerochs, domesticated by man, 83;
extirpation of, 85.
Val de Lys, evidence of glacier action in, 252.
Vegetable life, transfer by man's action, 59.
amount of ligneous products of, 173;
protection against avalanches afforded by, 269;
power of resisting the action of fire, 273;
American forest trees, 274;
their dimensions, 275;
change in relative proportions of height and diameter, 276;
comparative longevity of, 277;
European and American compared, 308;
species more numerous in America, 309;
Spenser's catalogue of, 308;
interchange of European and American species, 310;
species of Southern Europe and their extent, 312;
natural order of succession in, 323.
See Forest, Woods.
Trieste, proposed supply of water to, 536.
Trout, the American, 115, 117, 121.
Tuscany, rivers of, their deposits, 414;
physical restoration in, 416;
improvements in Val di Chiana, 417;
do. in the Maremma, 424.
Tyrolese rivers, elevation of their beds, 249.
Ubate, lakes of, New Granada, 204.
Undulation of water, 456.
United States, foreign plants grown in, 61;
weight of annual harvest in, 62;
number of quadrupeds in, 79;
of birds, 86;
effect of felling woods on its climate, 180;
forests of, 300;
instability of life in, 328.
Upper Alps, department of, ravages of torrents in, 240.
Urus, or auerochs, domesticated by man, 83;
extirpation of, 85.
Val de Lys, evidence of glacier action in, 252.
Vegetable life, transfer by man's action, 59.
Page 560
Velino, cascade of, Tivoli, 402.
Vesuvius, vegetation on, 131;
eruption of February, 1851, 544.
Volcanic action, resistance to, 544;
matter, vegetation in, 131.
Volga river, proposed diversion of, 531.
Walcheren, formation of the island, 340.
Wallenstadt, lake of, 534.
Walnut tree, consumption of, for gun stocks, 296;
oil yielded by, 310.
Ward's cases for plants, 175.
Waste products, utilization of, 37.
Weeds common to Old and New World, 66;
extirpated in China, &c., 71.
Whale, the, food of, 113;
destruction of, 114.
Whale fishery, date of its commencement unknown, 112;
in the middle ages, 112;
American, 113.
Wheat, its asserted origin, 73;
introduction to America, 74.
Wild animals, number of, 84.
Wild organisms, vegetable and animal, tenacity of life in, 69.
Willow, the weeping, introduction in Europe, 64.
Wolf, increase of the, 84;
prevalence in forests of France, 296.
Wolf Spring, Soubey, 206.
Wood, increased demand for, 293;
ship building, railroads, &c., 294;
market price of, 294;
replaced by iron in the arts, 295;
Vesuvius, vegetation on, 131;
eruption of February, 1851, 544.
Volcanic action, resistance to, 544;
matter, vegetation in, 131.
Volga river, proposed diversion of, 531.
Walcheren, formation of the island, 340.
Wallenstadt, lake of, 534.
Walnut tree, consumption of, for gun stocks, 296;
oil yielded by, 310.
Ward's cases for plants, 175.
Waste products, utilization of, 37.
Weeds common to Old and New World, 66;
extirpated in China, &c., 71.
Whale, the, food of, 113;
destruction of, 114.
Whale fishery, date of its commencement unknown, 112;
in the middle ages, 112;
American, 113.
Wheat, its asserted origin, 73;
introduction to America, 74.
Wild animals, number of, 84.
Wild organisms, vegetable and animal, tenacity of life in, 69.
Willow, the weeping, introduction in Europe, 64.
Wolf, increase of the, 84;
prevalence in forests of France, 296.
Wolf Spring, Soubey, 206.
Wood, increased demand for, 293;
ship building, railroads, &c., 294;
market price of, 294;
replaced by iron in the arts, 295;
Page 561
means of increasing its durability, 295;
how affected by rapid growth, 306;
facilities for working, 307.
Woods, habitable earth originally covered by, 128;
conditions of their propagation, 131;
destructive agency of man and domestic animals, 132;
do not furnish food for man, 133;
first removal of, 134;
burning of, 136;
in Sweden and France, 137;
effect on the soil, 138;
destruction of, its effect, 139;
electrical influence of, 140;
chemical influence of, 142;
influence on temperature, 143;
absorbing and emitting surface of, 144;
in summer and winter, 147;
dead products of, 148;
as a shelter, 149;
in France, 149, 151;
New England, 149;
Italy and Jutland, 150;
as a protection against malaria, 154;
tend to mitigate extremes of temperature, 155.
See Forest, Trees.
Wood mosses and fungi, absorbent of moisture, 168.
Woodpecker, the, destroyer of insects, 109.
Yak, or Tartary ox, the, 83.
Yew tree, geographical range of, 70.
Zeeland, province, formation of, 339.
Zostera marina, 492.
Zuiderzee, proposed drainage of, 534;
means of, and geographical results, 535.
THE END.
how affected by rapid growth, 306;
facilities for working, 307.
Woods, habitable earth originally covered by, 128;
conditions of their propagation, 131;
destructive agency of man and domestic animals, 132;
do not furnish food for man, 133;
first removal of, 134;
burning of, 136;
in Sweden and France, 137;
effect on the soil, 138;
destruction of, its effect, 139;
electrical influence of, 140;
chemical influence of, 142;
influence on temperature, 143;
absorbing and emitting surface of, 144;
in summer and winter, 147;
dead products of, 148;
as a shelter, 149;
in France, 149, 151;
New England, 149;
Italy and Jutland, 150;
as a protection against malaria, 154;
tend to mitigate extremes of temperature, 155.
See Forest, Trees.
Wood mosses and fungi, absorbent of moisture, 168.
Woodpecker, the, destroyer of insects, 109.
Yak, or Tartary ox, the, 83.
Yew tree, geographical range of, 70.
Zeeland, province, formation of, 339.
Zostera marina, 492.
Zuiderzee, proposed drainage of, 534;
means of, and geographical results, 535.
THE END.
Page 562
FORSYTH'S "CICERO."
A New Life of Cicero.
BY WILLIAM FORSYTH, M. A., Q. C.
With Twenty Illustrations. 2 vols. crown octavo. Printed on tinted and laid
paper. Price, $5.00.
The object of this work is to exhibit Cicero not merely as a Statesman
and an Orator, but as he was at home in the relations of private life, as a
Husband, a Father, a Brother, and a Friend. His letters are full of interesting
details, which enable us to form a vivid idea of how the old Romans lived
2,000 years ago; and the Biography embraces not only a History of Events,
as momentous as any in the annals of the world, but a large amount of
Anecdote and Gossip, which amused the generation that witnessed the
downfall of the Republic.
A New Life of Cicero.
BY WILLIAM FORSYTH, M. A., Q. C.
With Twenty Illustrations. 2 vols. crown octavo. Printed on tinted and laid
paper. Price, $5.00.
The object of this work is to exhibit Cicero not merely as a Statesman
and an Orator, but as he was at home in the relations of private life, as a
Husband, a Father, a Brother, and a Friend. His letters are full of interesting
details, which enable us to form a vivid idea of how the old Romans lived
2,000 years ago; and the Biography embraces not only a History of Events,
as momentous as any in the annals of the world, but a large amount of
Anecdote and Gossip, which amused the generation that witnessed the
downfall of the Republic.
Page 563
The London Athenæuem says: "Mr. Forsyth has rightly aimed to set before us a portrait of Cicero
in the modern style of biography, carefully gleaning from his extensive correspondence all those little
traits of character and habit which marked his private and domestic life. These volumes form a very
acceptable addition to the classic library. The style is that of a scholar and a man of taste."
From the Saturday Review:—"Mr. Forsyth has discreetly told his story, evenly and pleasantly
supplied it with apt illustrations from modern law, eloquence, and history, and brought Cicero as near
to the present time as the differences of age and manners warrant. * * * These volumes we heartily
recommend as both a useful and agreeable guide to the writings and character of one who was next in
intellectual and political rank to the foremost man of all the world, at a period when there were many
to dispute with him the triple crown of forensic, philosophic, and political composition."
"A scholar without pedantry, and a Christian without cant, Mr. Forsyth seems to have seized with
praiseworthy tact the precise attitude which it behoves a biographer to take when narrating the life,
the personal life, of Cicero. Mr. Forsyth produces what we venture to say will become one of the
classics of English biographical literature, and will be welcomed by readers of all ages and both
sexes, of all professions and of no profession at all."—London Quarterly.
"This book is a valuable contribution to our Standard Literature. It is a work which will aid our
progress towards the truth; it lifts a corner of the veil which has hung over the scenes and actors of
times so full of ferment, and allows us to catch a glimpse of the stage upon which the great drama
was played."—North American Review.
Copies sent by mail, post paid, on receipt of price.
LORD DERBY'S "HOMER."
T h e I l i a d o f H o m e r.
RENDERED INTO ENGLISH BLANK VERSE BY
EDWARD, EARL OF DERBY.
From the fifth London Edition.
Two volumes, royal octavo, on tinted paper. Price $7.50 per vol.
Extracts from Notices and Reviews from the English
Quarterlies, &c.
"The merits of Lord Derby's translation may be summed up in one word: "it is eminently
attractive; it is instinct with life; it may be read with fervent interest; it is immeasurably nearer than
in the modern style of biography, carefully gleaning from his extensive correspondence all those little
traits of character and habit which marked his private and domestic life. These volumes form a very
acceptable addition to the classic library. The style is that of a scholar and a man of taste."
From the Saturday Review:—"Mr. Forsyth has discreetly told his story, evenly and pleasantly
supplied it with apt illustrations from modern law, eloquence, and history, and brought Cicero as near
to the present time as the differences of age and manners warrant. * * * These volumes we heartily
recommend as both a useful and agreeable guide to the writings and character of one who was next in
intellectual and political rank to the foremost man of all the world, at a period when there were many
to dispute with him the triple crown of forensic, philosophic, and political composition."
"A scholar without pedantry, and a Christian without cant, Mr. Forsyth seems to have seized with
praiseworthy tact the precise attitude which it behoves a biographer to take when narrating the life,
the personal life, of Cicero. Mr. Forsyth produces what we venture to say will become one of the
classics of English biographical literature, and will be welcomed by readers of all ages and both
sexes, of all professions and of no profession at all."—London Quarterly.
"This book is a valuable contribution to our Standard Literature. It is a work which will aid our
progress towards the truth; it lifts a corner of the veil which has hung over the scenes and actors of
times so full of ferment, and allows us to catch a glimpse of the stage upon which the great drama
was played."—North American Review.
Copies sent by mail, post paid, on receipt of price.
LORD DERBY'S "HOMER."
T h e I l i a d o f H o m e r.
RENDERED INTO ENGLISH BLANK VERSE BY
EDWARD, EARL OF DERBY.
From the fifth London Edition.
Two volumes, royal octavo, on tinted paper. Price $7.50 per vol.
Extracts from Notices and Reviews from the English
Quarterlies, &c.
"The merits of Lord Derby's translation may be summed up in one word: "it is eminently
attractive; it is instinct with life; it may be read with fervent interest; it is immeasurably nearer than
Page 564
Pope to the text of the original. * * * We think that Lord Derby's translation will not only be read, but
read over and over again. * * * Lord Derby has given to England a version far more closely allied to
the original, and superior to any that has yet been attempted in the blank verse of our language."—
Edinburgh Review, January 1865.
"As often as we return from even the best of them (other translations) to the translation before us,
we find ourselves in a purer atmosphere of taste. We find more spirit, more tact in avoiding either
trivial or conceited phrases, and altogether a presence of merits, and an absence of defects which
continues, as we read, to lengthen more and more the distance between Lord Derby and the foremost
of his competitors."—London Quarterly Review, January, 1865.
"While the versification of Lord Derby is such as Pope himself would have admired, his Iliad is
in all other essentials superior to that of his great rival. For the rest, if Pope is dethroned what
remains? * * * It is the Iliad we would place in the hands of English readers as the truest counterpart
of the original, the nearest existing approach to a reproduction of that original's matchless feature."—
Saturday Review.
"Among those curiosities of literature which are also its treasures, Lord Derby's translation of
Homer must occupy a very conspicuous place. * * * Lord Derby's work is, on the whole, more
remarkable for the constancy of its excellence and the high level which it maintains throughout, than
for its special bursts of eloquence. It is uniformly worthy of itself and its author."—The Reader.
"Whatever may be the ultimate fate of this poem—whether it take sufficient hold of the public
mind to satisfy that demand for a translation of Homer which we have alluded to, and thus become a
permanent classic of the language, or whether it give place to the still more perfect production of
some yet unknown poet—it must equally be considered a splendid performance; and for the present
we have no hesitation in saying that it is by far the best representation of Homer's Iliad in the English
language."
AMERICAN NOTICES.
The Publishers Circular says:—At the advanced age of sixty-five, the Earl of Derby, leader of the
Tory party in England, has published a translation of Homer, in blank verse. Nearly all the London
critics unite in declaring, with The Times, "that it is by far the best representation of Homer's 'Iliad' in
the English language." His purpose was to produce a translation, and not a paraphrase—fairly and
honestly giving the sense of every passage and of every line. Without doubt the greatest of all living
British orators, he has now shown high poetic power as well as great scholarship.
From the New York World:—"The reader of English, who seeks to know what Homer really was,
and in what fashion he thought and felt and wrote, will owe to Lord Derby his first honest
opportunity of doing so. The Earl's translation is devoid alike of pretension and of prettiness. It is
animated in movement, simple and representative to phraseology, breezy in atmosphere, if we may so
speak, and pervaded by a refinement of taste which is as far removed from daintiness or effeminacy
as can well be imagined."
Copies sent by mail, post paid, on receipt of price.
read over and over again. * * * Lord Derby has given to England a version far more closely allied to
the original, and superior to any that has yet been attempted in the blank verse of our language."—
Edinburgh Review, January 1865.
"As often as we return from even the best of them (other translations) to the translation before us,
we find ourselves in a purer atmosphere of taste. We find more spirit, more tact in avoiding either
trivial or conceited phrases, and altogether a presence of merits, and an absence of defects which
continues, as we read, to lengthen more and more the distance between Lord Derby and the foremost
of his competitors."—London Quarterly Review, January, 1865.
"While the versification of Lord Derby is such as Pope himself would have admired, his Iliad is
in all other essentials superior to that of his great rival. For the rest, if Pope is dethroned what
remains? * * * It is the Iliad we would place in the hands of English readers as the truest counterpart
of the original, the nearest existing approach to a reproduction of that original's matchless feature."—
Saturday Review.
"Among those curiosities of literature which are also its treasures, Lord Derby's translation of
Homer must occupy a very conspicuous place. * * * Lord Derby's work is, on the whole, more
remarkable for the constancy of its excellence and the high level which it maintains throughout, than
for its special bursts of eloquence. It is uniformly worthy of itself and its author."—The Reader.
"Whatever may be the ultimate fate of this poem—whether it take sufficient hold of the public
mind to satisfy that demand for a translation of Homer which we have alluded to, and thus become a
permanent classic of the language, or whether it give place to the still more perfect production of
some yet unknown poet—it must equally be considered a splendid performance; and for the present
we have no hesitation in saying that it is by far the best representation of Homer's Iliad in the English
language."
AMERICAN NOTICES.
The Publishers Circular says:—At the advanced age of sixty-five, the Earl of Derby, leader of the
Tory party in England, has published a translation of Homer, in blank verse. Nearly all the London
critics unite in declaring, with The Times, "that it is by far the best representation of Homer's 'Iliad' in
the English language." His purpose was to produce a translation, and not a paraphrase—fairly and
honestly giving the sense of every passage and of every line. Without doubt the greatest of all living
British orators, he has now shown high poetic power as well as great scholarship.
From the New York World:—"The reader of English, who seeks to know what Homer really was,
and in what fashion he thought and felt and wrote, will owe to Lord Derby his first honest
opportunity of doing so. The Earl's translation is devoid alike of pretension and of prettiness. It is
animated in movement, simple and representative to phraseology, breezy in atmosphere, if we may so
speak, and pervaded by a refinement of taste which is as far removed from daintiness or effeminacy
as can well be imagined."
Copies sent by mail, post paid, on receipt of price.
Page 565
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