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Title: Cosmos: A Sketch of the Physical Description of the Universe, Vol. 1

Author: Alexander von Humboldt

Translator: E. C. Otté

Release date: January 3, 2005 [eBook #14565]
Most recently updated: October 28, 2024

Language: English

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Credits: This eBook was prepared by Amy Zelmer

*** START OF THE PROJECT GUTENBERG EBOOK COSMOS: A
SKETCH OF THE PHYSICAL DESCRIPTION OF THE UNIVERSE,
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This material taken from pages i-ii, iv and v, and 3-12

COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1
by Alexander von Humboldt

Translated by E C Otte

from the 1858 Harper & Brothers edition of Cosmos, volume 1
—————————————————————————

p i COSMOS

VOLUME I

[p ii is blank]

[p iii - not copied; pertains to reprint series]

p iv [portrait]

pv

COSMOS

A SKETCH OR A PHYSICAL DESCRIPTION OF THE UNIVERSE

BY ALEXANDER VON HUMBOLDT

TRANSLATED FROM THE GERMAN BY E. C. OTTE

Naturae vero rerum vis atque majestas in omnibus momentis fides caret,
si quis modo partes ejus ac non totam complectatur animo. — Plin., 'Hist.
Nat.', lib. vii, c. 1.

VOLUME I

WITH AN INTRODUCTION BY NICOLAAS A. RUPKE

THE JOHNS HOPKINS UNIVERSITY PRESS
Baltimore and London

[page vi and Introduction to the 1997 edition not copied]

p 1 COSMOS

VOLUME I

[p 2 is blank]

p 3 TRANSLATOR'S PREFACE. ———————————-

I CAN not more appropriately introduce the Cosmos than by presenting a
brief sketch of the life of its illustrious author.* While the name of
Alexander von Humboldt is familiar to every one, few, perhaps, are aware
of the peculiar circumstances of his scientific career and of the extent of his
labors in almost every department of physical knowledge. He was born on
the 14th of September, 1769, and is, therefore, now in his 80th year. After
going through the ordinary course of education at Gottingen, and having
made a rapid tour through Holland, England, and France, he became a pupil
of Werner at the mining school of Freyburg, and in his 21st year published
an "Essay on the Basalts of the Rhine." Though he soon became officially
connected with the mining corps, he was enabled to continue his excursions
in foreign countries, for, during the six or seven years succeeding the

publication of his first essay, he seems to have visited Austria, Switzerland,
Italy, and France. His attention to mining did not, however, prevent him
from devoting his attention to other scientific pursuits, among which botany
and the then recent discovery of galvanism may be especially noticed.
Botany, indeed, we know from his own authority, occupied him almost
exclusively for some years; but even at this time he was practicing the use
of those astronomical and physical instruments which he afterward turned
to so singularly excellent an account.

[footnote] *For the following remarks I am mainly indebted to the
articles on the Cosmos in the two leading Quarterly Reviews.

The political disturbances of the civilized world at the close p 4 of the
last century prevented our author from carrying out various plans of foreign
travel which he had contemplated, and detained him an unwilling prisoner
in Europe. In the year 1799 he went to Spain, with the hope of entering
Africa from Cadiz, but the unexpected patronage which he received at the
court of Madrid led to a great alteration in his plans, and decided him to
proceed directly to the Spanish possessions in America, "and there gratify
the longings for foreign adventure, and the scenery of the tropics, which
had haunted him from boyhood, but had all along been turned in the
diametrically opposite direction of Asia." After encountering various risks
of capture, he succeeded in reaching America, and from 1799 to 1804
prosecuted there extensive researches in the physical geography of the New
World, which has indelibly stamped his name in the undying records of
science.

Excepting an excursion to Naples with Gay-Lussac and Von Buch in
1805 (the year after his return from America), the succeeding twenty years
of his life were spent in Paris, and were almost exclusively employed in
editing the results of his American journey. In order to bring these results

before the world in a manner worthy of their importance, he commenced a
series of gigantic publications in almost every branch of science on which
he had instituted observations. In 1817, after twelve years of incessant toil,
four fifths were completed, and an ordinary copy of the part then in print
cost considerably more than one hundred pounds sterling. Since that time
the publication has gone on more slowly, and even now after the lapse of
nearly half a century, it remains, and probably ever will remain, incomplete.

In the year 1828, when the greatest portion of his literary labor had been
accomplished, he undertook a scientific journey to Siberia, under the
special protection of the Russian government. In this journey — a journey
for which he had prepared himself by a course of study unparalleled in the
history of travel — he was accompanied by two companions hardly less
distinguished than himself, Ehrenberg and Gustav Rose, and p 5 the results
obtained during their expedition are recorded by our author in his
'Fragments Asiatiques', and in his 'Asie Centrale', and by Rose in his 'Reise
nach dem Oural'. If the 'Asie Centrale' had been his only work, constituting,
as it does, an epitome of all the knowledge acquired by himself and by
former travelers on the physical geography of Northern and Central Asia,
that work alone would have sufficed to form a reputation of the highest
order.

I proceed to offer a few remarks on the work of which I now present a
new translation to the English public, a work intended by its author "to
embrace a summary of physical knowledge, as connected with a delineation
of the material universe."

The idea of such a physical description of the universe had, it appears,
been present to his mind from a very early epoch. It was a work which he
felt he must accomplish, and he devoted almost a lifetime to the
accumulation of materials for it. For almost half a century it had occupied

his thoughts; and at length, in the evening of life, he felt himself rich
enough in the accumulation of thought, travel, reading, and experimental
research, to reduce into form and reality the undefined vision that has so
long floated before him. The work, when completed, will form three
volumes. The 'first' volume comprises a sketch of all that is at present
known of the physical phenomena of the universe; the 'second'
comprehends two distinct parts, the first of which treats of the incitements
to the study of nature, afforded in descriptive poetry, landscape painting,
and the cultivation of exotic plants; while the second and larger part enters
into the consideration of the different epochs in the progress of discovery
and of the corresponding stages of advance in human civilization. The
'third' volume, the publication of which, as M. Humboldt himself informs
me in a letter addressed to my learned friend and publisher, Mr. H. G. Bohn,
"has been somewhat delayed, owing to the present state of public affairs,
will comprise the special and scientific development of the great Picture of
Nature p 6 Each of the three parts of the 'Cosmos' is therefore, to a certain
extent, distinct in its object, and may be considered complete in itself. We
can not better terminate this brief notice than in the words of one of the
most eminent philosophers of our own country, that, "should the conclusion
correspond (as we doubt not) with these beginnings, a work will have been
accomplished every way worthy of the author's fame, and a crowning laurel
added to that wreath with which Europe will always delight to surround the
name of Alexander von Humboldt."

In venturing to appear before the English public as the interpreter of "the
great work of our age,"* I have been encouraged by the assistance of many
kind literary and scientific friends, and I gladly avail myself of this
opportunity of expressing my deep obligations to Mr. Brooke, Dr. Day,
Professor Edward Forbes, Mr. Hind, Mr. Glaisher, Dr. Percy, and Mr.
Ronalds, for the valuable aid they have afforded me.

[footnote] *The expression applied to the Cosmos by the learned Bunsen,
in his late Report on Ethnology, in the 'Report of the British Association for'
1847, p. 265.

It would be scarcely right to conclude these remarks without a reference
to the translations that have preceded mine. The translation executed by
Mrs. Sabine is singularly accurate and elegant. The other translation is
remarkable for the opposite qualities, and may therefore be passed over in
silence. The present volumes differ from those of Mrs. Sabine in having all
the foreign measures converted into corresponding English terms, in being
published at considerably less than one third of the price, and in being a
translation of the entire work, for I have not conceived myself justified in
omitting passages, sometimes amounting to pages, simply because they
might be deemed slightly obnoxious to our national prejudices.

p 7 AUTHOR'S PREFACE. —————————-

In the late evening of an active life I offer to the German public a work,
whose undefined image has floated before my mind for almost half a
century. I have frequently looked upon its completion as impracticable, but
as often as I have been disposed to relinquish the undertaking, I have again
— although perhaps imprudently — resumed the task. This work I now
present to my contemporaries with a diffidence inspired by a just mistrust of
my own powers, while I would willingly forget that writings long expected
are usually received with less indulgence.

Although the outward relations of life, and an irresistible impulse toward
knowledge of various kinds, have led me to occupy myself for many years
— and apparently exclusively — with separate branches of science, as, for
instance, with descriptive botany, geognosy, chemistry, astronomical

determinations of position, and terrestrial magnetism, in order that I might
the better prepare myself for the extensive travels in which I was desirous
of engaging, the actual object of my studies has nevertheless been of a
higher character. The principal impulse by which I was directed was the
earnest endeavor to comprehend the phenomena of physical objects in their
general connection, and to represent nature as one great whole, moved and
animated by internal forces. My intercourse with highly-gifted men early
led me to discover that, without an earnest striving to attain to a knowledge
of special branches of study, all attempts to give a grand and general view
of the universe would be nothing more than a vain illusion. These special
departments in the great domain of natural p 8 science are, moreover,
capable of being reciprocally fructified by means of the appropriative forces
by which they are endowed. Descriptive botany, no longer confined to the
narrow circle of the determination of genera and species, leads the observer
who traverses distant lands and lofty mountains to the study of the
geographical distribution of plants of the earth's surface, according to
distance from the equator and vertical elevation above the sea. It is further
necessary to investigate the laws which regulate the differences of
temperature and climate, and the meteorological processes of the
atmosphere, before we can hope to explain the involved causes of vegetable
distribution; and it is thus that the observer who earnestly pursues the path
of knowledge is led from one class of phenomena to another, by means of
the mutual dependence and connection existing between them.

I have enjoyed an advantage which few scientific travelers have shared to
an equal extent, viz., that of having seen not only littoral districts, such as
are alone visited by the majority of those who take part in voyages of
circumnavigation, but also those portions of the interior of two vast
continents which present the most striking contrasts manifested in the
Alpine tropical landscapes of South America, and the dreary wastes of the
steppes in Northern Asia. Travels, undertaken in districts such as these,

could not fail to encourage the natural tendency of my mind toward a
generalization of views, and to encourage me to attempt, in a special work,
to treat of the knowledge which we at present possess, regarding the
sidereal and terrestrial phenomena of the Cosmos in their empirical
relations. The hitherto undefined idea of a physical geography has thus, by
an extended and perhaps too boldly imagined a plan, been comprehended
under the idea of a physical description of the universe, embracing all
created things in the regions of space and in the earth.

The very abundance of the materials which are presented to the mind for
arrangement and definition, necessarily impart no inconsiderable difficulties
in the choice of the form under p 9 which such a work must be presented, if
it would aspire to the honor of being regarded as a literary composition.
Descriptions of nature ought not to be deficient in a tone of life-like
truthfulness, while the mere enumeration of a series of general results is
productive of a no less wearying impression than the elaborate
accumulation of the individual data of observation. I scarcely venture to
hope that I have succeeded in satisfying these various requirements of
composition, or that I have myself avoided the shoals and breakers which I
have known how to indicate to others. My faint hope of success rests upon
the special indulgence which the German public have bestowed upon a
small work bearing the title of 'Ansichten der Natur', which I published
soon after my return from Mexico. This work treats, under general points of
view, of separate branches of physical geography (such as the forms of
vegetation, grassy plains, and deserts). The effect produced by this small
volume has doubtlessly been more powerfully manifested in the influence it
has exercised on the sensitive minds of the young, whose imaginative
faculties are so strongly manifested, than by means of any thing which it
could itself impart. In the work on the Cosmos on which I am now engaged,
I have endeavored to show, as in that entitled 'Ansichten der Natur', that a
certain degree of scientific completeness in the treatment of individual facts

is not wholly incompatible with a picturesque animation of style. Since
public lectures seemed to me to present an easy and efficient means of
testing the more or less successful manner of connecting together the
detached branches of any one science, I undertook, for many months
consecutively, first in the French language, at Paris, and afterward in my
own native German, at Berlin (almost simultaneously at two different
places of assembly), to deliver a course of lectures on the physical
description of the universe, according to my conception of the science. My
lectures were given extemporaneously, both in French and German, and
without the aid of written notes, nor have I, in any way, made use, in the
present work, p 10 of those portions of my discourses which have been
preserved by the industry of certain attentive auditors. With the exception of
the first forty pages, the whole of the present work was written, for the first
time, in the years 1843 and 1844.

A character of unity, freshness, and animation must, I think, be derived
from an association with some definite epoch, where the object of the writer
is to delineate the present condition of knowledge and opinions. Since the
additions constantly made to the latter give rise to fundamental changes in
pre-existing views, my lectures and the Cosmos have nothing in common
beyond the succession in which the various facts are treated. The first
portion of my work contains introductory considerations regarding the
diversity in the degrees of enjoyment to be derived from nature, and the
knowledge of the laws by which the universe is governed; it also considers
the limitation and scientific mode of treating a physical description of the
universe, and gives a general picture of nature which contains a view of all
the phenomena comprised in the Cosmos.

This general picture of nature, which embraces within its wide scope the
remotest nebulous spots, and the revolving double stars in the regions of
space, no less than the telluric phenomena included under the department of

the geography of organic forms (such as plants, animals, and races of men),
comprises all that I deem most specially important with regard to the
connection existing between generalities and specialities, while it moreover
exemplifies, by the form and style of the composition, the mode of
treatment pursued in the selection of the results obtained from experimental
knowledge. The two succeeding volumes will contain a consideration of the
particular means of incitement toward the study of nature (consisting in
animated delineations, landscape painting, and the arrangement and
cultivation of exotic vegetable forms), of the history of the contemplation of
the universe, or the gradual development of the reciprocal action of natural
forces constituting one natural whole; and lastly, of the special p 11
branches of the several departments of science, whose mutual connection is
indicated in the beginning of the work. Wherever it has been possible to do
so, I have adduced the authorities from whence I derived my facts, with a
view of affording testimony both to the accuracy of my statements and to
the value of the observations to which reference was made. In those
instances where I have quoted from my own writings (the facts contained in
which being, from their very nature, scattered through different portions of
my works), I have always referred to the original editions, owing to the
importance of accuracy with regard to numerical relations, and to my own
distrust of the care and correctness of translators. In the few cases where I
have extracted short passages from the works of my friends, I have
indicated them by marks of quotation; and, in imitation of the practice of
the ancients, I have invariably preferred the repetition of the same words to
any arbitrary substitution of my own paraphrases. The much-contested
question of priority of claim to a first discovery, which it is so dangerous to
treat of in a work of this uncontroversial kind, has rarely been touched
upon. Where I have occasionally referred to classical antiquity, and to that
happy period of transition which has rendered the sixteenth and seventeenth
centuries so celebrated, owing to the great geographical discoveries by

which the age was characterized, I have been simply led to adopt this mode
of treatment, from the desire we experience from time to time, when
considering the general views of nature, to escape from the circle of more
strictly dogmatical modern opinions, and enter the free and fanciful domain
of earlier presentiments.

It has frequently been regarded as a subject of discouraging
consideration, that while purely literary products of intellectual activity are
rooted in the depths of feeling, and interwoven with the creative force of
imagination, all works treating of empirical knowledge, and of the
connection of natural phenomena and physical laws, are subject to the most
marked modifications of form in the lapse of short periods of time, both p
12 by the improvement in the instruments used, and by the consequent
expansion of the field of view opened to rational observation, and that those
scientific works which have, to use a common expression, become
'antiquated' by the acquisition of new funds of knowledge, are thus
continually being consigned to oblivion as unreadable. However
discouraging such a prospect must be, no one who is animated by a genuine
love of nature, and by a sense of the dignity attached to its study, can view
with regret any thing which promises future additions and a greater degree
of perfection to general knowledge. Many important branches of knowledge
have been based upon a solid foundation which will not easily be shaken,
both as regards the phenomena in the regions of space and on the earth;
while there are other portions of science in which general views will
undoubtedly take the place of merely special; where new forces will be
discovered and new substances will be made known, and where those
which are now considered as simple will be decomposed. I would,
therefore, venture to hope that an attempt to delineate nature in all its vivid
animation and exalted grandeur, and to trace the 'stable' amid the
vacillating, ever-recurring alternation of physical metamorphoses, will not
be wholly disregarded even at a future age. 'Potsdam, Nov.', 1844.

This material taken from pages 13-22
NB - The page numbers will be properly aligned in Courier 12 font.

COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1
by Alexander von Humboldt

Translated by E C Otte

from the 1858 Harper & Brothers edition of Cosmos, volume 1
—————————————————————————

p 13

CONTENTS OF VOL. I. ———————————

Page
The Translator's Preface . . . . . . . . . . . . . . . . . . . . . .3
The Author's Preface . . . . . . . . . . . . . . . . . . . . . . . .7
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

INTRODUCTION.
The Results of the Study of Physical Phenomena . . . . . . . . . . 23
The different Epochs of the Contemplation of the external World . .24
The different Degrees of Enjoyment presented by the Contemplation
of Nature . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Instances of this Species of Enjoyment . . . . . . . . . . . . . . 26
Means by which it is induced . . . . . . . . . . . . . . . . . . . 26
The Elevations and climatic Relations of many of the most
celebrated Mountains in the World, considered with
Reference to the Effect produced on the Mind of the
Observer . . . . . . . . . . . . . . . . . . . . . . . . . .27-33
The Impressions awakened by the Aspect of tropical Regions . . . . 34

The more accurate Knowledge of the Physical Forces of the
Universe, acquired by the Inhabitants of a small Section
of the temperate Zone . . . . . . . . . . . . . . . . . . . . .36
The earliest Dawn of the Science of the Cosmos . . . . . . . . . . 36
The Difficulties that opposed the Progress of Inquiry . . . . . . . 37
Consideration of the Effect produced on the Mind by the
Observation of Nature, and the Fear entertained by some of
its injurious Influence . . . . . . . . . . . . . . . . . . . 40
Illustrations of the Manner in which many recent Discoveries have
tended to Remove the groundless Fears entertained
regarding the Agency of certain Natural Phenomena . . . . . . 43
The Amount of Scientific Knowledge required to enter on the
Consideration of Physical Phenomena . . . . . . . . . . . . . 47
The Object held in View by the present Work . . . . . . . . . . . . 49
The Nature of the Study of the Cosmos . . . . . . . . . . . . . . . 50
The special Requirements of the present Age . . . . . . . . . . . . 53
Limits and Method of Exposition of the Physical Description of the
Universe . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Considerations on the terms Physiology and Physics . . . . . . . . .58
Physical Geography . . . . . . . . . . . . . . . . . . . . . . . . 59
Celestial Phenomena . . . . . . . . . . . . . . . . . . . . . . . . 63
The Natural Philosophy of the Ancients directed more to Celestial
than to Terrestrial Phenomena . . . . . . . . . . . . . . . . .65
The able Treatises of Varenius and Carl Ritter . . . . . . . . .66, 67
Signification of the Word Cosmos . . . . . . . . . . . . . . . . 68-70
The Domain embraced by Cosmography . . . . . . . . . . . . . . . . 71
Empiricism and Experiments . . . . . . . . . . . . . . . . . . . . 74
The Process of Reason and Induction . . . . . . . . . . . . . . . .77
p 14
GENERAL REVIEW OF NATURAL PHENOMENA.

Connection between the Material and the Ideal World . . . . . . . . 80
Delineation of Nature . . . . . . . . . . . . . . . . . . . . . . . 82
Celestial Phenomena . . . . . . . . . . . . . . . . . . . . . . . . 83
Sidereal Systems . . . . . . . . . . . . . . . . . . . . . . . . . 89
Planetary Systems . . . . . . . . . . . . . . . . . . . . . . . . .90
Comets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Aerolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111
Zodiacal Light . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Translatory Motion of the Solar System . . . . . . . . . . . . . . 145
The Milky Way . . . . . . . . . . . . . . . . . . . . . . . . . . .150
Starless Openings . . . . . . . . . . . . . . . . . . . . . . . 152
Terrestrial Phenomena . . . . . . . . . . . . . . . . . . . . . . .154
Geographical Distribution . . . . . . . . . . . . . . . . . . . . .161
Figure of the Earth . . . . . . . . . . . . . . . . . . . . . . . .163
Density of the Earth . . . . . . . . . . . . . . . . . . . . . . . 169
Internal Heat of the Earth . . . . . . . . . . . . . . . . . . . . 172
Mean Temperature of the Earth . . . . . . . . . . . . . . . . . . .175
Terrestrial Magnetism . . . . . . . . . . . . . . . . . . . . . . 177
Magnetism . . . . . . . . . . . . . . . . . . . . . . . . . . . . .183
Aurora Borealis . . . . . . . . . . . . . . . . . . . .. . . . . .193
Geognostic Phenomena . . . . . . . . . . . . . . . . . . . . . . . 202
Earthquakes . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Gaseous Emanations . . . . . . . . . . . . . . . . . . . . . . . . 207
Hot Springs . . . . . . . . . . . . . . . . . . . . . . . . . . . .221
Salses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .224
Volcanoes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227
Rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .247
Palaeontology . . . . . . . . . . . . . . . . . . . . . . . . . . .270
Geognostic Periods . . . . . . . . . . . . . . . . . . . . . . . . 286
Physical Geography . . . . . . . . . . . . . . . . . . . . . . . . 287

Meteorology . . . . . . . . . . . . . . . . . . . . . . . . . . . .311
Atmospheric Pressure . . . . . . . . . . . . . . . . . . . . . . . 315
Climatology . . . . . . . . . . . . . . . . . . . . . . . . . . . .317
The Snow-line . . . . . . . . . . . . . . . . . . . . . . . . . . .329
Hygrometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Atmospheric Electricity . . . . . . . . . . . . . . . . . . . . . .335
Organic Life . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Motion in Plants . . . . . . . . . . . . . . . . . . . . . . . . . 341
Universality of Animal Life . . . . . . . . . . . . . . . . . . . .342
Geography of Plants and Animals . . . . . . . . . . . . . . . . . .346
Floras of different Countries . . . . . . . . . . . . . . . . . . .350
Man . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .352
Races . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .353
Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Conclusion of the Subject . . . . . . . . . . . . . . . . . . . . .359

p 15 SUMMARY. —————-

Translator's Preface.
Author's Preface.

Vol I.

GENERAL SUMMARY OF THE CONTENTS.

Introduction. — Reflections on the different Degrees of Enjoyment
presented to us by the Aspect of Nature and the scientific Exposition of the
Laws of the Universe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 23-78

Insight into the connection of phenomena as the aim of all natural
investigation. Nature presents itself to meditative contemplation as a unity

in diversity. Differences in the grades of enjoyment yielded by nature.
Effect of contact with free nature; enjoyment derived from nature
independently of a knowledge of the action of natural forces, or of the
physiognomy and configuration of the surface, or of the character of
vegetation. Reminiscences of the woody valleys of the Cordilleras and of
the Peak of Teneriffe. Advantages of the mountainous region near the
equator, where the multiplicity of natural impressions attains its maximum
within the most circumscribed limits, and where it is permitted to man
simultaneously to behold all the stars of the firmament and all the forms of
vegetation — p. 23-33.

Tendency toward the investigation of the causes of physical phenomena.
Erroneous views of the character of natural forces arising from an imperfect
mode of observation or of induction. The crude accumulation of physical
dogmas transmitted from one country to another. Their diffusion among the
higher classes. Scientific physics are associated with another and a deep-
rooted system of untried and misunderstood experimental positions.
Investigation of natural laws. Apprehension that nature may lose a portion
of its secret charm by an inquiry into the internal character of its forces, and
that the enjoyment of nature must necessarily be weakened by a study of its
domain. Advantages of general views which impart an exalted and solemn
character to natural science. The possibility of separating generalities from
specialties. Examples drawn from astronomy, recent optical discoveries,
physical geognosy, and the geography of plants. Practicability of the study
of physical cosmography — p. 33-54. Misunderstood popular knowledge,
confounding cosmography with a mere encyclopedic enumeration of
natural sciences. Necessity for a simultaneous regard for all branches of
natural science. Influence of this study on national prosperity and the
welfare of nations; its more earnest and characteristic aim is an inner one,
arising from exalted mental activity. Mode of treatment with regard to the

object and presentation; reciprocal connection existing between thought and
speech — p. 54-56.

The notes to p. 28-33. Comparative hypsometrical data of the elevations
of the Dhawalagiri, Jawahir, Chimborazo, Aetna (according to the
measurement of Sir John Herschel), the Swiss Alps, etc. — p. 28. Rarity p
16 of palms and ferns in the Himalaya Mountains — p. 29. European
vegetable forms in the Indian Mountains — p. 30. Northern and southern
limits of perpetual snow on the Himalaya; influence of the elevated plateau
of Thibet — p. 30-33. Fishes of an earlier world — p. 46.

Limits and Method of Exposition of the Physical Description of the
Universe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . Page 56-78

Subjects embraced by the study of the Cosmos or of physical
cosmography. Separation of other kindred studies — p. 56-62. The
uranological portion of the Cosmos is more simple than the telluric; the
impossibility of ascertaining the diversity of matter simplifies the study of
the mechanism of the heavens. Origin of the word 'Cosmos', its
signification of adornment and order of the universe. The 'existing' can not
be absolutely separated in our contemplation of nature from the 'future'.
History of the world and description of the world — p. 26-73. Attempts to
embrace the multiplicity of the phenomena of the Cosmos in the unity of
thought and under the form of a purely rational combination. Natural
philosophy, which preceded all exact observation in antiquity, is a natural,
but not unfrequently ill-directed, effort of reason. Two forms of abstraction
rule in the whole mass of knowledge, viz.: the 'quantitative', relative
determinations according to number and magnitude, and 'qualitative',
material characters. Means of submitting phenomena to calculation. Atoms,
mechanical methods of construction. Figurative representations; mythical
conception of imponderable matters, and the peculiar vital forces in every

organism. That which is attained by observation and experiment (calling
forth phenomena) leads, by analogy and induction, to a knowledge of
'empirical laws'; their gradual simplification and generalization.
Arrangement of the facts discovered in accordance with leading ideas. The
treasure of empirical contemplation, collected through ages, is in no danger
of experiencing any hostile agency from philosophy — p. 73-78.

[In the notes appended to p. 66-70 are considerations of the general and
comparative geography of Varenius. Philological investigation into the
meaning of the words [Greek word] and 'mundus'.]

Delineation of Nature. General Review of Natural Phenomena. . . . . p.
79-359

Introduction — p. 79-83. A descriptive delineation of the world embraces
the whole universe ([Greek words]) in the celestial and terrestrial spheres.
Form and course of the representation. It begins with the laws of
gravitation, and with the region of the remotest nebulous spots and double
stars, and then, gradually descending through the starry stratum to which
our solar system belongs, it contemplates this terrestrial spheroid,
surrounded by air and water, and finally, proceeds to the consideration of
the form of our planet, its temperature and magnetic tension, and the
fullness of organic vitality which is unfolded on its surface under the action
of light. Partial insight into the relative dependence existing among all
phenomena. Amid all the mobile and unstable elements in space, 'mean
numerical values' are the ultimate aim of investigation, being the expression
of the physical laws, or forces of the Cosmos. The delineation of the
universe does not begin with the earth, from which a merely subjective
point of view might have led us to start, but rather with the objects
comprised in the regions of space. Distribution of matter, which is partially
conglomerated into rotating p 17 and circling heavenly bodies of very

different density and magnitude, and partly scattered as self-luminous
vapor. Review of the separate portions of the picture of nature, for the
purpose of explaining the reciprocal connection of all phenomena.

I. Celestial Portion of the Cosmos . . . . . . . . . . . . . . . . .Page 83-154

II. Terrestrial Portion of the Cosmos . . . . . . . . . . . . . . . .p. 154-359

a. Form of the earth, its mean density, quantity of heat, electro-magnetic
activity, process of light — p. 154-202.

b. Vital activity of the earth toward its external surface. Reaction of the
interior of a planet on its crust and surface. Subterranean noise without
waves of concussion. Earthquakes dynamic phenomena — p. 202-217.

c. Material products which frequently accompany earthquakes. Gaseous
and aqueous springs. Salses and mud volcanoes. Upheavals of the soil by
elastic forces — p. 217-228.

d. Fire-emitting mountains. Craters of elevation. Distribution of
volcanoes on the earth — p. 228-247.

e. Volcanic forces form new kinds of rock, and metamorphose those
already existing. Geognostical classification of rocks into four groups.
Phenomena of contact. Fossiliferous strata; their vertical arrangement. The
faunas and floras of an earlier world. Distribution of masses of rock — p.
247-384.

f. Geognostical epochs, which are indicated by the mineralogical
difference of rocks, have determined the distribution of solids and fluids
into continents and seas. Individual configuration of solids into horizontal
expansion and vertical elevation. Relations of area. Articulation. Probability
of the continued elevation of the earth's crust in ridges — p. 284-301.

g. Liquid and aeriform envelopes of the solid surface of our planet.
Distribution of heat in both. The sea. The tides. Currents and their effects —
p. 301-311.

h. The atmosphere. Its chemical composition. Fluctuations in its density.
Law of the direction of the winds. Mean temperature. Enumeration of the
causes which tend to raise and lower the temperature. Continental and
insular climates. East and west coasts. Cause of the curvature of the
isothermal lines. Limits of perpetual snow. Quantity of vapor. Electricity in
the atmosphere. Forms of the clouds — p. 311-339.

i. Separation of inorganic terrestrial life from the geography of vital
organisms; the geography of vegetables and animals. Physical gradations of
the human race — p. 339-359.

Special Analysis of the Delineation of Nature, including References to
the
Subjects treated of in the Notes.

I. Celestial Portion of the Cosmos . . . . . . . . . . . . . . . . . p. 83-154

The universe and all that it comprises — multiform nebulous spots,
planetary vapor, and nebulous stars. The picturesque charm of a southern
sky — note, p. 85. Conjectures on the position in space of the world. Our
stellar masses. A cosmical island. Gauging stars. Double stars revolving
round a common center. Distance of the star 61 Cygni — p. 88 and note.
Our solar system more complicated than was conjectured at the close of the
last century. Primary planets with Neptune, Astrea, Hebe, Iris, and Flora,
now constitute 16; secondary planets 18; myriad of comets of which many
of the inner ones are inclosed p 18 in the orbits of the planets; a rotating
ring (the zodiacal light) and meteoric stones, probably to be regarded as

small cosmical bodies. The telescopic planets, Vesta, Juno, Ceres, Pallas,
Astrea, Hebe, Iris and Flora, with their frequently intersecting, strongly
inclined, and more eccentric orbits, constitute a central group of separation
between the inner planetary group (Mercury, Venus, the Earth, and Mars)
and the outer group (Jupiter, Saturn, Uranus, and Neptune). Contrasts of
these planetary groups. Relations of distance from one central body.
Differences of absolute magnitude, density, period of revolution,
eccentricity, and inclination of the orbits. The so-called law of the distances
of the planets from their central sun. The planets which have the largest
number of moons — p. 96 and note. Relations in space, both absolute and
relative, of the secondary planets. Largest and smallest of the moons.
Greatest approximation to a primary planet. Retrogressive movement of the
moons of Uranus. Libration of the Earth's satellite — p. 98 and note.
Comets; the nucleus and tail; various forms and directions of the
emanations in conoidal envelopes, with more or less dense walls. Several
tails inclined toward the sun; change of form of fixed stars by the nuclei of
comets. Eccentricity of their orbits and periods of revolution. Greatest
distance and greatest approximation of comets. Passage through the system
of Jupiter's satellites. Comets of short periods of revolution, more correctly
termed inner comets (Encke, Biela, Faye) — p. 107 and note. Revolving
aerolites (meteoric stones, fire-balls, falling stars). Their planetary velocity,
magnitude, form, observed height. Periodic return in streams; the
November stream and the stream of St. Lawrence. Chemical composition of
meteoric asteroids — p. 130 and notes. Ring of zodiacal light. Limitation of
the present solar atmosphere — p. 141 and note. Translatory motion of the
whole solar system — p. 145-149 and note. The existence of the law of
gravitation beyond our solar system. The milky way of stars and its
conjectured breaking up. Milky way of nebulous spots, at right angles with
that of the stars. Periods of revolutions of bi-colored double stars. Canopy
of stars; openings in the stellar stratum. Events in the universe; the

apparition of new stars. Propagation of light, the aspect of the starry vault of
the heavens conveys to the mind an idea of inequality of time — p. 149-154
and notes.

II. Terrestrial Portion of the Cosmos . . . . . . . . . . . . . . Page 154-359

a. Figure of the earth. Density, quantity of heat, electro-magnetic tension,
and terrestrial light — p. 154-202 and note. Knowledge of the compression
and curvature of the earth's surface acquired by measurements of degrees,
pendulum oscillations, and certain inequalities in the moon's orbit. Mean
density of the earth. The earth's crust, and the depth to which we are able to
penetrate — p. 159, 160, note. Threefold movement of the heat of the earth;
its thermic condition. Law of the increase of heat with the increase of depth
— p. 160, 161 and note. Magnetism electricity in motion. Periodical
variation of terrestrial magnetism. Disturbance of the regular course of the
magnetic needle. Magnetic storms; extension of their action. Manifestations
of magnetic force on the earth's surface presented under three classes of
phenomena, namely, lines of equal force (isodynamic), equal inclination
(isoclinic), and equal deviation (isogonic). Position of the magnetic pole. Its
probable connection with the poles of cold. Change of all the magnetic
phenomena of the earth. Erection of magnetic observatories p 19 since
1828; a far-extending net-work of magnetic stations — p. 190 and note.
Development of light at the magnetic poles; terrestrial light as a
consequence of the electro-magnetic activity of our planet. Elevation of
polar light. Whether magnetic storms are accompanied by noise.
Connection of polar light (an electro-magnetic development of light) with
the formation of cirrus clouds. Other examples of the generation of
terrestrial light — p. 202 and note.

b. The vital activity of a planet manifested from within outward, the
principal source of geognostic phenomena. Connection between merely

dynamic concussions or the upheaval of whole portions of the earth's crust,
accompanied by the effusion of matter, and the generation of gaseous and
liquid fluids, of hot mud and fused earths, which solidify into rocks.
Volcanic action, in the most general conception of the idea, is the reaction
of the interior of a planet on its outer surface. Earthquakes. Extent of the
circles of commotion and their gradual increase. Whether there exists any
connection between the changes in terrestrial magnetism and the processes
of the atmosphere. Noises, subterranean thunder without any perceptible
concussion. The rocks which modify the propagation of the waves of
concussion. Upheavals; eruption of water, hot steam, mud mofettes, smoke,
and flame during an earthquake — p. 202-218 and notes.

c. Closer consideration of material products as a consequence of internal
planetary activity. There rise from the depths of the earth, through fissures
and cones of eruption, various gases, liquid fluids (pure or acidulated), mud,
and molten earths. Volcanoes are a species of intermittent spring.
Temperature of thermal springs; their constancy and change. Depth of the
foci — p. 219-224 and notes. Salses, mud volcanoes. While fire-emitting
mountains, being sources of molten earths, produce volcanic rocks, spring
water forms, by precipitation, strata of limestone. Continued generation of
sedimentary rocks — p. 228 and note.

d. Diversity of volcanic elevations. Dome-like closed trachytic
mountains. Actual volcanoes which are formed from craters of elevations or
among the detritus of their original structure. Permanent connection of the
interior of our earth with the atmosphere. Relation to certain rocks.
Influence of the relations of height on the frequency of the eruptions.
Heights of the cone of cinders. Characteristics of those volcanoes which
rise above the snow-line. Columns of ashes and fire. Volcanic storm during
the eruption. Mineral composition of lavas — p. 236 and notes. Distribution
of volcanoes on the earth's surface; central and linear volcanoes; insular and

littoral volcanoes. Distance of volcanoes from the sea-coast. Extinction of
volcanic forces — p. 246 and notes.

e. Relation of volcanoes to the character of rocks. Volcanic forces form
new rocks, and metamorphose the more ancient ones. The study of these
relations leads, by a double course, to the mineral portion of geognosy (the
study of the textures and of the position of the earth's strata), and to the
configuration of continents and insular groups elevated above the level of
the sea (the study of the geographical form and outlines of the different
parts of the earth. Classification of rocks according to the scale of the
phenomena of structure and metamorphosis, which are still passing before
our eyes. Rocks of eruption, sedimentary rocks, changed (metamorphosed)
rocks, conglomerates — compound rocks are definite associations of
cryctognostically simple fossils. There are four phases in the formative
condition; rocks of eruption, p 20 endogenous (granite, sienite, porphyry,
greenstone, hyperathene, rock, euphotide, melaphyre, basalt, and
phonolithe); sedimentary rocks (silurian schist, coal measures, limestone,
travertino, infusorial deposit); metamorphosed rock, which contains also,
together with the detritus mica schist, and more ancient metamorphic
masses. Aggregate and sandstone formations. The phenomenon of contact
explained by the artificial imitation of minerals. Effects of pressure and the
various rapidity of cooling. Origin of granular or saccharoidal marble,
silicification of schist into ribbon jasper. Metamorphosis of calcareous marl
into micaceous schist through granite. Conversion of dolomite and granite
into argillaceous schist, by contact with basaltic and doleritic rocks. Filling
up of the veins from below. Processes of cementation in agglomerate
structures. Friction conglomerates — p. 269 and note. Relative age of rocks,
chronometry of the earth's crust. Fossiliferous strata. Relative age of
organisms. Simplicity of the first vital forms. Dependence of physiological
gradations on the age of the formations. Geognostic horizon, whose careful
investigation may yield certain data regarding the identity or the relative

age of formations, the periodic recurrence of certain strata, their parallelism,
or their total suppression. Types of the sedimentary structures considered in
their most simple and general characters; silurian and devonian formations
(formerly known as rocks of transition); the lower trias (mountain
limestone, coal measures, together with 'todilegende' and zechstein); the
upper trias (butter sandstone, muschelkalk, and keuper); Jura limestone (lias
and oolite); freestone, lower and upper chalk, as the last of the flotz strata,
which begin with mountain limestone; tertiary formations in three divisions,
which are designated by granular limestone, lignite, and south Apennine
gravel — p. 269-278.

The faunas and floras of an earlier world, and their relations to existing
organisms. Colossal bones of antediluvian mammalia in the upper alluvium.
Vegetation of an earlier world; monuments of the history of its vegetation.
The points at which certain vegetable groups attain their maximum;
cycadeae in the keuper and lias, and coniferae in the butter sandstone.
Lignite and coal measures (amber-tree). Deposition of large masses of rock;
doubts regarding their origin — p. 285 and note.

f. The knowledge of geognostic epochs — of the upheaval of mountain
chains and elevated plateaux, by which lands are both formed and
destroyed, leads, by an internal causal connection, to the distribution into
solids and fluids, and to the peculiarities in the natural configuration of the
earth's surface. Existing areal relations of the solid to the fluid differ
considerably from those presented by the maps of the physical portion of a
more ancient geography. Importance of the eruption of quartzose, porphyry
with reference to the then existing configuration of continental masses.
Individual conformation in horizontal extension (relations of articulation)
and in vertical elevation (hypsometrical views). Influence of the relations of
the area of land and sea on the temperature, direction of the winds,
abundance or scarcity of organic products, and on all meteorological

processes collectively. Direction of the major axes of continental masses.
Articulation and pyramidal termination toward the south. Series of
peninsulas. Valley-like formation of the Atlantic Ocean. Forms which
frequently recur — p. 285-293 and notes. Ramifications and systems of
mountain chains, and the means of determining their relative ages. Attempts
to determine the centre of gravity of the volume of the lands upheaved
above the level p 21 of the sea. The elevation of continents is still
progressing slowly, and is being compensated for at some definite points by
a perceptible sinking. All geognostic phenomena indicate a periodical
alteration of activity in the interior of our planet. Probability of new
elevations of ridges — p. 293-301 and notes.

g. The solid surface of the earth has two envelopes, one liquid, and the
other aeriform. Contrasts and analogies which these envelopes — the sea
and the atmosphere — present in their conditions of aggregation and
electricity, and in their relations of currents and temperature. Depths of the
ocean and of the atmosphere, the shoals of which constitute our highlands
and mountain chains. The degree of heat at the surface of the sea in
different latitudes and in the lower strata. Tendency of the sea to maintain
the temperature of the surface in the strata nearest to the atmosphere, in
consequence of the mobility of its particles and the alteration in its density.
Maximum of the density of salt water. Position of the zones of the hottest
water, and of those having the greatest saline contents. Thermic influence of
the lower polar current and the counter currents in the straits of the sea — p.
302-304 and notes. General level of the sea, and permanent local
disturbances of equilibrium; the periodic disturbances manifested as tides.
Oceanic currents; the equatorial or rotation current, the Atlantic warm Gulf
Stream, and the further impulse which it receives; the cold Peruvian stream
in the eastern portion of the Pacific Ocean of the southern zone.
Temperature of shoals. The universal diffusion of life in the ocean.
Influence of the small submarine sylvan region at the bottom of beds of

rooted algae, or on far-extending floating layers of fucus — p. 302-311 and
notes.

h. The gaseous envelope of our planet, the atmosphere. Chemical
composition of the atmosphere, its transparency, its polarization, pressure,
temperature, humidity, and electric tension. Relation of oxygen to nitrogen;
amount of carbonic acid; carbureted hydrogen; ammoniacal vapors.
Miamata. Regular (horary) changes in the pressure of the atmosphere. Mean
barometrical height at the level of the sea in different zones of the earth.
Isobarometrical curves. Barometrical windroses. Law of rotation of the
winds, and its importance with reference to the knowledge of many
meteorological processes. Land and sea winds, trade winds and monsoons
— p. 311-317. Climatic distribution of heat in the atmosphere, as the effect
of the relative position of transparent and opaque masses (fluid and solid
superficial area), and of the hypsometrical configuration of continents.
Curvature of the isothermal lines in a horizontal and vertical direction, on
the earth's surface and in the superimposed strata of air. Convexity and
concavity of the isothermal lines. Mean heat of the year, seasons, months,
and days. Enumeration of the causes which produce disturbances in the
form of isothermal lines, i.e., their deviation from the position of the
geographical parallels. Isochimenal and isotheral lines are the lines of equal
winter and summer heat. Causes which raise or lower the temperature.
Radiation of the earth's surface, according to its inclination, color, density,
dryness, and chemical composition. The form of the cloud which announces
what is passing in the upper strata of the atmosphere is the image of the
strongly radiating ground projected on a hot summer sky. Contrast between
an insular or littoral climate, such as is experienced by all deeply-articulated
continents, and the climate of the interior of large tracts of land. East and
west coasts. Difference between the southern and northern hemispheres.
Thermal scales of p 22 cultivated plants, going down from the vanilla,
cacoa, and musaceae, by citrous and olives, and to vines yielding potable

wines. The influence which these scales exercise on the geographical
distribution of cultivated plants. The favorable ripening and the immaturity
of fruits are essentially influenced by the difference in the action of direct or
scattered light in a clear sky or in one overcast with mist. General summary
of the causes which yield a more genial climate to the greater portion of
Europe considered as the western peninsula of Asia — p. 326.
Determination of the changes in the mean annual and summer temperature,
which correspond to one degree of geographical latitude. Equality of the
mean temperature of a mountain station, and of the polar distance of any
point lying at the level of the sea. Decrease of temperature with the
decrease in elevation. Limits of perpetual snow, and the fluctuations in
these limits. Causes of disturbance in the regularity of the phenomenon.
Northern and southern chains of the Himalaya; habitability of the elevated
plateaux of Thibet — p. 331. Quantity of moisture in the atmosphere,
according to the hours of the day, the seasons of the year, degrees of
latitude, and elevation. Greatest dryness of the atmosphere observed in
Northern Asia, between the river districts of the Irtysch and the Obi. Dew, a
consequence of radiation. Quantity of rain — p. 335. Electricity of the
atmosphere, and disturbance of the electric tension. Geographical
distribution of storms. Predettermination of atmospheric changes. The most
important climatic disturbances can not be traced, at the place of
observation, to any local cause, but are rather the consequence of some
occurrence by which the equilibrium in the atmospheric currents has been
destroyed at some considerable distance — p. 335-339.

i. Physical geography is not limited to elementary inorganic terrestrial
life, but, elevated to a higher point of view, it embraces the sphere of
organic life, and the numerous gradations of its typical development.
Animal and vegetable life. General diffusion of life in the sea and on the
land; microscopic vital forms discovered in the polar ice no less than in the
depths of the ocean within the tropics. Extension imparted to the horizon of

life by Ehrenberg's discoveries. Estimation of the mass (volume) of animal
and vegetable organisms — p. 339-346. Geography of plants and animals.
Migrations of organisms in the ovum, or by means of organs capable of
spontaneous motion. Spheres of distribution depending on climatic
relations. Regions of vegetation, and classification of the genera of animals.
Isolated and social living plants and animals. The character of flora and
fauna is not determined so much by the predominance of separate families,
in certain parallels of latitude, as by the highly complicated relations of the
association of many families, and the relative numerical value of their
species. The forms of natural families which increase or decrease from the
equator to the poles. Investigations into the numerical relation existing in
different districts of the earth between each one of the large families to the
whole mass of phanerogamia — p. 346-351. The human race considered
according to its physical gradations, and the geographical distribution of its
simultaneously occurring types. Races and varieties. All races of men are
forms of one single species. Unity of the human race. Languages considered
as the intellectual creations of mankind, or as portions of the history of
mental activity, manifest a character of nationality, although certain
historical occurrences have been the means of diffusing idioms of the same
family of languages among nations of wholly different descent — p. 351-
359.

In This material taken from pages 23 to 56

COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1
by Alexander von Humboldt

Translated by E C Otte

from the 1858 Harper & Brothers edition of Cosmos, volume 1
—————————————————————————

p 23 INTRODUCTION. ————————

REFLECTIONS ON THE DIFFERENT DEGREES OF ENJOYMENT PRESENTED TO US
BY THE ASPECT OF NATURE AND THE STUDY OF HER LAWS.

In attempting, after a long absence from my native country, to develop
the physical phenomena of the globe, and the simultaneous action of the
forces that pervade the regions of space, I experience a two-fold cause of
anxiety. The subject before me is so inexhaustible and so varied, that I fear
either to fall into the superficiality of the encyclopedist, or to weary the
mind of my reader by aphorisms consisting of mere generalities clothed in
dry and dogmatical forms. Undue conciseness often checks the flow of
expression, while diffuseness is alike detrimental to a clear and precise
exposition of our ideas. Nature is a free domain, and the profound
conceptions and enjoyments she awakens within us can only be vividly
delineated by thought clothed in exalted forms of speech, worthy of bearing
witness to the majesty and greatness of the creation.

In considering the study of physical phenomena, not merely in its
bearings on the material wants of life, but in its general influence on the
intellectual advancement of mankind, we find its noblest and most
important result to be a knowledge of the chain of connection, by which all
natural forces are linked together, and made mutually dependent upon each
other; and it is the perception of these relations that exalts our views and
ennobles our enjoyments. Such a result can, however, only be reaped as the
fruit of observation and intellect, combined with the spirit of the age, in
which are reflected all the varied phases of thought. He who can trace,
through by-gone times, the stream of our knowledge to its primitive source,
will learn from history how, for thousands of years, man has labored, amid

the ever-recurring changes of form, to recognize the invariability of natural
laws, and has thus, by the force of mind, gradually subdued a great portion
of the physical world to his dominion. In interrogating the history of the
past, we trace the mysterious course of ideas yielding the first glimmering
perception of the same image of p 24 a Cosmos, or harmoniously ordered
whole, which, dimly shadowed forth to the human mind in the primitive
ages of the world, is now fully revealed to the maturer intellect of mankind
as the result of long and laborious observation.

Each of these epochs of the contemplation of the external world — the
earliest dawn of thought and the advanced stage of civilization — has its
own source of enjoyment. In the former, this enjoyment, in accordance with
the simplicity of the primitive ages, flowed from an intuitive feeling of the
order that was proclaimed by the invariable and successive reappearance of
the heavenly bodies, and by the progressive development of organized
beings; while in the latter, this sense of enjoyment springs from a definite
knowledge of the phenomena of nature. When man began to interrogate
nature, and, not content with observing, learned to evoke phenomena under
definite conditions; when once he sought to collect and record facts, in
order that the fruit of his labors might aid investigation after his own brief
existence had passed away, the 'philosophy of Nature' cast aside the vague
and poetic garb in which she had been enveloped from her origin, and,
having assumed a severer aspect, she now weighs the value of observations,
and substitutes induction and reasoning for conjecture and assumption. The
dogmas of former ages survive now only in the superstitions of the people
and the prejudices of the ignorant, or are perpetuated in a few systems,
which, conscious of their weakness, shroud themselves in a vail of mystery.
We may also trace the same primitive intuitions in languages exuberant in
figurative expressions; and a few of the best chosen symbols engendered by
the happy inspiration of the earliest ages, having by degrees lost their

vagueness through a better mode of interpretation, are still preserved among
our scientific terms.

Nature considered 'rationally', that is to say, submitted to the process of
thought, is a unity in diversity of phenomena; a harmony blending together
all created things, however dissimilar in form and attributes; one great
whole ([Greek words]) animated by the breath of life. The most important
result of a rational inquiry into nature is, therefore, to establish the unity and
harmony of this stupendous mass of force and matter, to determine with
impartial justice what is due to the discoveries of the past and to those of
the present, and to analyze the individual parts of natural phenomena
without succumbing beneath the weight of the whole. Thus, and thus alone,
is it permitted to man, while mindful of the high destiny p 25 of his race, to
comprehend nature, to lift the vail that shrouds her phenomena, and as it
were, submit the results of observation to the test of reason and of intellect.

In reflecting upon the different degrees of enjoyment presented to us in
the contemplation of nature, we find that the first place must be assigned to
a sensation, which is wholly independent of an intimate acquaintance with
the physical phenomena presented to our view, or of the peculiar character
of the region surrounding us. In the uniform plain bounded only by a distant
horizon, where the lowly heather, the cistus, or waving grasses, deck the
soil; on the ocean shore, where the waves, softly rippling over the beach,
leave a track, green with the weeds of the sea; every where, the mind is
penetrated by the same sense of the grandeur and vast expanse of nature,
revealing to the soul, by a mysterious inspiration, the existence of laws that
regulate the forces of the universe. Mere communion with nature, mere
contact with the free air, exercise a soothing yet strengthening influence on
the wearied spirit, calm the storm of passion, and soften the heart when
shaken by sorrow to its inmost depths. Every where, in every region of the
globe, in every stage of intellectual culture, the same sources of enjoyment

are alike vouchsafed to man. The earnest and solemn thoughts awakened by
a communion with nature intuitively arise from a presentiment of the order
and harmony pervading the whole universe, and from the contrast we draw
between the narrow limits of our own existence and the image of infinity
revealed on every side, whether we look upward to the starry vault of
heaven, scan the far-stretching plain before us, or seek to trace the dim
horizon across the vast expanse of ocean.

The contemplation of the individual characteristics of the landscape, and
of the conformation of the land in any definite region of the earth, gives rise
to a different source of enjoyment, awakening impressions that are more
vivid, better defined, and more congenial to certain phases of the mind, than
those of which we have already spoken. At one time the heart is stirred by a
sense of the grandeur of the face of nature, by the strife of the elements, or,
as in Northern Asia by the aspect of the dreary barrenness of the far-
stretching steppes; at another time, softer emotions are excited by the
contemplation of rich harvests wrested by the hand of man from the wild
fertility of nature, or by the sight of human habitations raised beside some
wild and foaming torrent. Here I regard less the degree of intensity than the
difference existing in the p 26 various sensations that derive their charm and
permanence from the peculiar character of the scene.

If I might be allowed to abandon myself to the recollections of my own
distant travels, I would instance, among the most striking scenes of nature,
the calm sublimity of a tropical night, when the stars, not sparkling, as in
our northern skies, shed their soft and planetary light over the gently-
heaving ocean; or I would recall the deep valleys of the Cordilleras, where
the tall and slender palms pierce the leafy vail around them, and waving on
high their feathery and arrow-like branches for, as it were, "a forest above a
forest;"* or I would describe the summit of the Peak of Teneriffe, when a
horizontal layer of clouds, dazzling in whiteness, has separated the cone of

cinders from the plain below, and suddenly the ascending current pierces
the cloudy vail, so that the eye of the traveler may range from the brink of
the crater, along the vine-clad slopes of Orotava, to the orange gardens and
banana groves that skirt the shore. In scenes like these, it is not the peaceful
charm uniformly spread over the face of nature that moves the heart, but
rather the peculiar physiognomy and conformation of the land, the features
of the landscape, the ever varying outline of the clouds, and their blending
with the horizon of the sea, whether it lies spread before us like a smooth
and shining mirror, or is dimly seen through the morning mist. All that the
senses can but imperfectly comprehend, all that is most awful in such
romantic scenes of nature, may become a source of enjoyment to man, by
opening a wide field to the creative powers of his imagination. Impressions
change with the varying movements of the mind, and we are led by a happy
illusion to believe that we receive from the external world that with which
we have ourselves invested it.

[footnote] *This expression is taken from a beautiful description of
tropical forest scenery in 'Paul and Virginia', by Bernardia de Saint Pierre.

When far from our native country, after a long voyage, we tread for the
first time the soil of a tropical land, we experience a certain feeling of
surprise and gratification in recognizing, in the rocks that surround us, the
same inclined schistose strata, and the same columnar basalt covered with
cellular amygdaloids, that we had left in Europe, and whose identity of
character, in latitudes so widely different, reminds us that the solidification
of the earth's crust is altogether independent of climatic influences. But
these rocky masses of schist and of basalt are covered with vegetation of a
character with which we are unacquainted, and of a physiognomy wholly p
27 unknown to us; and it is then, amid the colossal and majestic forms of an
exotic flora, that we feel how wonderfully the flexibility of our nature fits

us to receive new impressions, linked together by a certain secret analogy.
We so readily perceive the affinity existing among all the forms of organic
life, that although the sight of a vegetation similar to that of our native
country might at first be most welcome to the eye, as the sweet familiar
sounds of our mother tongue are to the ear, we nevertheless, by degrees, and
almost imperceptibly, become familiarized with a new home and a new
climate. As a true citizen of the world, man every where habituates himself
to that which surrounds him; yet fearful, as it were, of breaking the links of
association that bind him to the home of his childhood, the colonist applies
to some few plants in a far-distant clime the names he had been familiar
with in his native land; and by the mysterious relations existing among all
types of organization, the forms of exotic vegetation present themselves to
his mind as nobler and more perfect developments of those he had loved in
earlier days. Thus do the spontaneous impressions of the untutored mind
lead, like the laborious deductions of cultivated intellect, to the same
intimate persuasion, that one sole and indissoluble chain binds together all
nature.

It may seem a rash attempt to endeavor to separate, into its different
elements, the magic power exercised upon our minds by the physical world,
since the character of the landscape, and of every imposing scene in nature,
depends so materially upon the mutual relation of the ideas and sentiments
simultaneously excited in the mind of the observer.

The powerful effect exercised by nature springs, as it were, from the
connection and unity of the impressions and emotions produced; and we
can only trace their different sources by analyzing the individuality of
objects and the diversity of forces.

The richest and most varied elements for pursuing an analysis of this
nature present themselves to the eyes of the traveler in the scenery of

Southern Asia, in the Great Indian Archipelago, and more especially, too, in
the New Continent, where the summits of the lofty Cordilleras penetrate the
confines of the aerial ocean surrounding our globe, and where the same
subterranean forces that once raised these mountain chains still shake them
to their foundation and threaten their downfall.

Graphic delineations of nature, arranged according to systematic views,
are not only suited to please the imagination, p 28 but may also, when
properly considered, indicate the grades of the impressions of which I have
spoken, from the uniformity of the sea-shore, or the barren steppes of
Siberia, to the inexhaustible fertility of the torrid zone. If we were even to
picture to ourselves Mount Pilatus placed on the Schreckhorn,* or the
Schneekoppe of Silesia on Mont Blanc, we should p 29 not have attained to
the height of that great Colossus of the Andes, the Chimborazo, whose
height is twice that of Mont Aetna; and we must pile the Righi, or Mount
Athos, on the summit of the Chimborazo, in order to form a just estimate of
the elevation of the Dhawalagiri, the highest point of the Himalaya.

[footnote] *These comparisons are only approximative. The several
elevations above the level of the sea are, in accurate numbers, as follows:
The Schneekoppe or Riesenkoppe, in Silesia about 5270 feet, according to
Hallaschka. The Righi, 5902 feet, taking the height of the Lake of Lucerne
at 1426 feet, according to Eschman. (See 'Compte Rendu des Mesures
Trigonometriques en Suisse', 1840, p. 230.) Mount Athos, 6775 feet,
according to Captain Gaultier; Mount Pilatus, 7546 feet; Mount Aetna,
10,871 feet, according to Captain Smyth; or 10,874 feet, according to the
barometrical measurement made by Sir John Herschel, and communicated
to me in writing in 1825, and 10,899 feet, according to angles of altitude
taken by Cacciatore at Palermo (calculated by assuming the terrestrial
refraction to be 0.076); the Schreckhorn, 12,383 feet; the Jungfrau, 13,720

feet, according to Tralles; Mount Blanc, 15,775 feet, according to the
different measurements considered by Roger ('Bibl. Univ.', May, 1828, 0.
24-53), 15,733 feet, according to the measurements taken from Mount
Columbier by Carlini in 1821, and 15,748 feet, as measured by the Austrian
engineers from Trelod and the Glacier d'Ambin.

[footnote continued] The actual height of the Swiss mountains fluctuates,
according to Eschman's observations, as much as 25 English feet, owing to
the varying thickness of the stratum of snow that covers the summits.
Chimborazo is, according to my trigonometrical measurements, 21,421 feet
(see Humboldt, 'Recueil d'Obs. Astr.', tome i., p. 73), and Dhawalagiri,
28,074 feet. As there is a difference of 445 feet between the determinations
of Blake and Webb, the elevation assigned to the Dhawalagiri (or white
mountain, from the Sanscrit 'dhawala', white, and 'giri', mountain) can not
be received with the same confidence as that of the Jawahir, 25,749 feet,
since the latter rests on a complete trigonomietrical measurement (see
Herbert and Hodgson in the 'Asiat. Res.', vol. xiv., p. 189, and Suppl. to
'Encycl. Brit.', vol. iv., p. 643). I have shown elsewhere ('Ann. des Sciences
Naturelles', Mars, 1825) that the height of the Dhawalagiri (28,074 feet)
depends on several elements that have not been ascertained with certainty,
as azimuths and latitudes (Humboldt, 'Asie Centrale', t. iii., p. 282). It has
been believed, but without foundation, that in the Tartaric chain, north of
Thibet, opposite to the chain of Kuen-lun, there are several snowy summits,
whose elevation is about 30,000 English feet (almost twice that of Mont
Blanc), or, at any rate, 29,000 feet (see Captain Alexander Gerard's and
John Gerard's 'Journey to the Boorendo Pass', 1840, vol. i., p. 143 and 311).
Chimborazo is spoken of in the text only as 'one' of the highest summits of
the chain of the Andes; for in the year 1827, the learned and highly-gifted
traveler, Pentland, in his memorable expedition to Upper Peru (Bolivia),
measured the elevation of two mountains situated to the east of Lake
Titicaca, viz., the Sorata, 25,200 feet, and the Illimani, 24,000 feet, both

greatly exceeding the height of Chimborazo, which is only 21,421 feet, and
being nearly equal in elevation to the Jawahir, which is the highest
mountain in the Himalaya that has as yet been accurately measured. Thus
Mont Blanc is 5646 feet below Chimborazo; Chimborazo, 3779 feet below
the Sorata; the Sorata, 549 feet below the Jawahir, and probably about 2880
feet below the Dhawalagiri. According to a new measurement of the
Illimani, by Pentland, in 1838, the elevation of this mountain is given at
23,868 feet, varying only 133 feet from the measurement taken in 1827.
The elevations have been given in this note with minute exactness, as
erroneous numbers have been introduced into many maps and tables
recently published, owing to incorrect reductions of the measurements. [In
the preceding note, taken from those appended to the Introduction in the
French translation, rewritten by Humboldt himself, the measurements are
given in meters, but these have been converted into English feet, for the
greater convenience of the general reader.] — 'Tr.'

But although the mountains of India greatly surpass the Cordilleras of
South America by their astonishing elevation (which, after being long
contested, has at last been confirmed by accurate measurements), they can
not, from their geographical position, present the same inexhaustible variety
of phenomena by which the latter are characterized. The impression
produced by the grander aspects of nature dies not depend exclusively on
height. The chain of the Himalaya is placed far beyond the limits of the
torrid zone, and scarcely is a solitary palm-tree to be found in the beautiful
valleys of Kumaoun and Garhwal.*

[Footnote] *The absence of palms and tree-ferns on the temperate slopes
of the Himalaya is shown in Don's 'Flora Nepalensis', 1825, and in the
remarkable series of lithographs of Wallich's 'Flora Indica', whose catalogue
contains the enormous number of 7683 Himalaya species, almost all

phanerogamic plants, which have as yet been but imperfectly classified. In
Nepaul (lat. 26 1/2 degrees to 27 1/4 degrees) there has hitherto been
observed only one species of palm, Chamaerops martiana, Wall. ('Plantae
Asiat.', lib. iii., p. 5,211), which is found at the height of 5250 English feet
above the level of the sea, in the shady valley of Bunipa. The magnificent
tree-fern, Alsophila brunoniana, Wall. (of which a stem 48 feet long has
been in the possession of the British Museum since 1831), does not grow in
Nepaul, but is found on the mountains of Silhet, to the northwest of
Calcutta, in lat. 24 degrees 50 minutes. The Nepaul fern, Paranema
cyathoides, Don, formerly known as Sphaeroptera barbata, Wall. ('Plantae
Asiat.', lib. i., p. 42, 48), is indeed, nearly related to Cyathea, a species of
which I have seen in the South American Missions of Caripe, measuring 33
feet in height; this is not, however, properly speaking a tree.

On the southern slope of the ancient Paropamisus, in the latitudes of 28
degrees and 34 degrees, nature no longer displays the same abundance of
tree-ferns and arborescent grasses, heliconias and orchideous plants, which
in tropical p 30 regions are to be found even on the highest plateaux of the
mountains. On the slope of the Himalaya, under the shade of the Deodora
and the broad-leaved oak, peculiar to these Indian Alps, the rocks of granite
and of mica schist are covered with vegetable forms almost similar to those
which characterize Europe and Northern Asia. The species are not identical,
but closely analogous in aspect and physiognomy, as, marsh parnassia, and
the prickly species of Ribes.* The chain of the Himalaya is also wanting in
the imposing phenomena of volcanoes, which in the Andes and in the
Indian Archipelago often reveal to the inhabitants, under the most terrific
forms, the existence of the forces pervading the interior of our planet.

[footnote] *Ribes nubicola, R. glaciale, R. grossularia. The species which
compose the vegetation of the Himalaya are four pines, notwithstanding the

assertion of the ancients regarding Eastern Asia (Strabo, lib. 11, p. 510,
Cas.), twenty-five oaks, four birches, two chestnuts, seven maples, twelve
willows, fourteen roses, three species of strawberry, seven species of Alpine
roses ('rhododendra'), one of which attains a height of 20 feet, and many
other northern genera. Large white apes, having black faces, inhabit the
wild chestnut-tree of Kashmir, which grows to a height of 100 feet, in lat.
33 degrees (see Carl von Hugel's 'Kaschmir', 1840, 2d pt. 249). Among the
Coniferae, we find the Pinus deodwara, or deodara (in Sanscrit, 'dewa-daru',
the timber of the gods), which is nearly allied to Pinus cedrus. Near the
limit of perpetual snow flourish the large and showy flowers of the
Gentiana venusta, G. Moorcroftiana, Swertia purpurescens, S. speciosa,
Parnassia armata, P. nubicola, Poenia Emode, Tulipa stellata; and besides
varieties of European genera peculiar to these Indian mountains, true
European species as Leontodon taraxacum, Prunella vulgaris, Galium
aparine, and Thlaspi arvense. The heath mentioned by Saunders, in Turner's
'Travels', and which had been confounded with Calluna vulgaris, is an
Andromeda, a fact of the greatest importance in the geography of Asiatic
plants. If I have made use, in this work, of the unphilosophical expressions
of European genera, 'European' special, 'growing wild in Asia', etc., it has
been in consequence of the old botanical language, which, instead of the
idea of a large dissemination, or, rather, of the coexistence of organic
productions, has dogmatically substituted the false hypothesis of a
migration, which, from predilection for Europe, is further assumed to have
been from west to east.

Moreover, on the southern declivity of the Himalaya, where the
ascending current deposits the exhalations rising from a vigorous Indian
vegetation, the region of perpetual snow begins at an elevation of 11,000 or
12,000 feet above the level of the sea,* thus setting a limit to the

development of organic p 31 life in a zone that is nearly 3000 feet lower
than that to which it attains in the equinoctial region of the Cordilleras.

[footnote] *On the southern declivity of the Himalaya, the limit of
perpetual snow is 12,978 feet above the level of the sea; on the northern
declivity, or, rather, on the peaks which rise above the Thibet, or Tartarian
plateau, this limit is at 16,625 feet from 30 1/2 degrees to 32 degrees of
latitude, while at the equator, in the Andes of Quito, it is 15,790 feet. Such
is the result I have deduced from the combination of numerous data
furnished by Webb, Gerard, Herbert, and Moorcroft. (See my two memoirs
on the mountains of India, in 1816 and 1820, in the 'Ann. de Chimie et de
Physique', t. iii., p. 303; t. xiv., p. 6, 22, 50.) The greater elevation to which
the limit of perpetual snow recedes on the Tartarian declivity is owing to the
radiation of heat from the neighboring elevated plains, to the purity of the
atmosphere, and to the infrequent formation of snow in an air which is both
very cold and very dry. (Humboldt, 'Asie Centrale', t. iii., p. 281-326.) My
opinion on the difference of height of the snow-line on the two sides of the
Himalaya has the high authority of Colebrooke in its favor. He wrote to me
in June, 1824, as follows: "I also find, from the data in my possession, that
the elevation of the line of perpetual snow is 13,000 feet. On the southern
declivity, and at latitude 31 degrees, Webb's measurements give me 13,500
feet, consequently 500 feet more than the height deduced from Captain
Hodgson's observations. Gerard's measurements fully confirm your opinion
that the line of snow is higher on the northern than on the southern side." It
was not until the present year (1840) that we obtained the complete and
collected journal of the brothers Gerard, published under the supervision of
Mr. Lloyd. ('Narrative of a Journey from Cawnpoor to the Boorendo Pass,
in the Himalaya, by Captain Alexander Gerard and John Gerard, edited by
George Lloyd', vol. i., p. 292, 311, 320, 327 and 341.) Many interesting
details regarding some localities may be found in the narrative of 'A Visit to

the Shatool, for the Purpose of determining the Line of Perpetual Snow on
the southern face of the Himalaya, in August', 1822. Unfortunately,
however, these travelers always confound the elevation at which sporadic
snow falls with the maximum of the height that the snow-line attains on the
Thibetian plateau. Captain Gerard distinguishes between the summits that
rise in the middle of the plateau, where he states the elevation of the snow-
line to be between 18,000 and 19,000 feet, and the northern slopes of the
chain of the Himalaya, which border on the defile of the Sutledge, and can
radiate but little heat, owing to the deep ravines with which they are
intersected. The elevation of the village of Tangno is given at only 9300
feet, while that of the plateau surrounding the sacred lake of Maqasa is
17,000 feet. Captain Gerard finds the snow-line 500 feet lower on the
northern slopes, where the chain of the Himalaya is broken through, than
toward the southern declivities facing Hindostan, and he there estimates the
line of perpetual snow at 15,000 feet. The most striking differences are
presented between the vegetation on the Thibetian plateau and that
characteristic of the southern slopes of the Himalaya. On the latter the
cultivation of grain is arrested at 9974 feet and even there the corn has often
to be cut when the blades are still green. The extreme limit of forests of tall
oaks and deodars is 11,960 feet; that of dwarf birches, 12,983 feet. On the
plains, Captain Gerard found pastures up to the height of 17,000 feet; the
cereals will grow at 14,100 feet, or even at 18,540 feet; birches with tall
stems at 14,100 feet, and copse or brush wood applicable for fuel is found
at an elevation of upward of 17,000 feet, that is to say, 1280 feet and above
the lower limits of the snow-line at the equator, in the province of Quito. It
is very desirable that the 'mean' elevation of the Thibetian plateau, which I
have estimated at only about 8200 feet between the Himalaya and the
Kuen-lun, and the difference in the height of the line of perpetual snow on
the southern and on the northern slopes of the Himalaya, should be again
investigated by travelers who are accustomed to judge of the general

conformation of the land. Hitherto simple calculations have too often been
confounded with actual measurements, and the elevations of isolated
summits with that of the surrounding plateau. (Compare Carl Zimmerman's
excellent Hypsometrical Remarks in his 'Geographischen Analyse der Karte
von Inner Asien', 1841, s. 98.) Lord draws attention to the difference
presented by the two faces of the Himalaya and those of the Alpine chain of
Hindoo-Coosh, with respect to the limits of the snow-line. "The latter
chain," he says, "has the table-land to the south, in consequence of which
the snow-line is higher on the southern side, contrary to what we find to be
the case with respect to the Himalaya, which is bounded on the south by
sheltered plains, as Hindoo-Coosh is on the north." It must, however, be
admitted that the hypsometrical data on which these statements are based
require a critical revision with regard to several of their details; but still they
suffice to establish the main fact, that the remarkable configuration of the
land in Central Asia affords man all that is essential to the maintenance of
life, as habitation, food, and fuel, at an elevation above the level of the sea
which in almost all other parts of the globe is covered with perpetual ice.
We must except the very dry districts of Bolivia, where snow is so rarely
met with, and where Pentland (in 1838) fixed the snow-line at 15,667 feet,
between 16 degrees and 17 3/4 degrees south latitude. The opinion that I
had advanced regarding the difference in the snow-line on the two faces of
the Himalaya has been most fully confirmed by the barometrical
observations of Victor Jacquemont, who fell an early sacrifice to his noble
and unwearied ardor. (See his 'Correspondance pendant son Voyage dans
l'Inde', 1828 'a' 1832, liv. 23, p. 290, 296, 299.) "Perpetual snow," says
Jacquemont, "descends lower on the southern than on the northern slopes of
the Himalaya, and the limit constantly rises as we advance to the north of
the chain bordering on India. On the Kionbrong, about 18,317 feet in
elevation, according to Captain Gerard, I was still considerably below the

limit of perpetual snow which I believe to be 19,690 feet in this part of
Hindostan." (This estimate I consider much too high.)

[Footnote continues] The same traveler says, "To whatever height we rise
on the southern declivity of the Himalaya, the climate retains the same
character, and the same division of the seasons as in the plains of India; the
summer solstice being every year marked by the same prevalence of rain
which continues to fall without intermission until the autumnal equinox.
But a new, a totally different climate begins at Kashmir, whose elevation I
estimate to be 5350 feet, nearly equal to that of the cities of Mexico and
Popayan" ('Correspond. de Jacquemont', t. ii., p. 58 et 74). The warm and
humid air of the sea, as Leopold von Buch well observes, is carried by the
monsoons across the plains of India to the skirts of the Himalaya which
arrest its course, and hinder it from diverging to the Thibetian districts of
Ladak and Lassa. Carl von Hugel estimates the elevation of the Valley of
Kashmir above the level of the sea at 5818 feet, and bases his observation
on the determination of the boiling point of water (see theil 11, s. 155, and
'Journal of Geog. Soc.', vol. vi., p. 215). In this valley, where the
atmosphere is scarcely ever agitated by storms, and in 34 degrees 7 minutes
lat., snow is found, several feet in thickness, from December to March.

p 32 But the countries bordering on the equator possess another
advantage, to which sufficient attention has not hitherto been p 33 directed.
This portion of the surface of the globe affords in the smallest space the
greatest possible variety of impressions from the contemplation of nature.
Among the colossal mountains of Cundinamarea, of Quito, and of Peru,
furrowed by deep ravines, man is enabled to contemplate alike all the
families of plants, and all the stars of the firmament. There, at a single
glance, the eye surveys majestic palms, humid forests of bambusa, and the
varied species of Musaceae, while above these forms of tropical vegetation
appear oaks, medlars, the sweet-brier, and umbelliferous plants, as in our

European homes. There as the traveler turns his eyes to the vault of heaven,
a single glance embraces the constellation of the Southern Cross, the
Magellanic clouds, and the guiding stars of the constellation of the Bear, as
they circle round the arctic pole. There the depths of the earth and the vaults
of heaven display all the richness of their forms and the variety of their
phenomena. There the different climates are ranged the one above the other,
stage by stage, like the vegetable zones, whose succession they limit; and
there the observer may readily trace the laws that regulate the diminution of
heat, as they stand indelibly inscribed on the rocky walls and abrupt
declivities of the Cordilleras.

Not to weary the reader with the details of the phenomena which I long
since endeavored graphically to represent,* I will here limit myself to the
consideration of a few of the general results whose combination constitutes
the 'physical delineation of the torrid zone.' That which, in the vagueness of
our p 34 impressions, loses all distinctness of form, like some distant
mountain shrouded from view by a vail of mist, is clearly revealed by the
light of mind, which, by its scrutiny into the causes of phenomena, learns to
resolve and analyze their different elements, assigning to each its individual
character. Thus, in the sphere of natural investigation, as in poetry and
painting, the delineation of that which appeals most strongly to the
imagination, derives its collective interest from the vivid truthfulness with
which the individual features are portrayed.

[footnote] *See, generally my 'Essai sur la Geographie des Plantes, et le
Tableau physique des Regions Equinoxiales', 1807, p. 80-88. On the diurnal
and nocturnal variations of temperature, see Plate 9 of my 'Atlas Geogr. et
Phys. du Nouveau Continent'; and the Tables in my work, entitled 'De
distributione Geographica Plantarum, secundum coeli tempriem, et
altitudinem Montium', 1817, p. 90-116; the meteorological portion of my

'Asie Centrale', t. iii., p. 212, 224; and, finally, the more recent and far more
exact exposition of the variations of temperature experienced in
correspondence with the increase of altitude on the chain of the Andes,
given in Boussingault's Memoir, 'Sur la profondeur a laquelle on trouve,
sous les Tropiques, la couche de Temperature Invariable.' (Ann. de Chimie
et de Physique, 1833, t. liii., p. 225-247.) This treatise contains the
elevations of 128 points, included between the level of the sea and the
declivity of the Antisana (17,900 feet), as well as the mean temperature of
the atmosphere, which varies with the height between 81 degrees and 35
degrees F.

The regions of the torrid zone not only give rise to the most powerful
impressions by their organic richness and their abundant fertility, but they
likewise afford the inestimable advantage of revealing to man, by the
uniformity of the variations of the atmosphere and the development of vital
forces, and by the contrasts of climate and vegetation exhibited at the
different elevations, the invariability of the laws that regulate the course of
the heavenly bodies, reflected, as it were, in terrestrial phenomena. Let us
dwell, then, for a few moments, on the proofs of this regularity, which is
such that it may be submitted to numerical calculation and computation.

In the burning plains that rise but little above the level of the sea, reign
the families of the banana, the cycas, and the palm, of which the number of
species comprised in the flora of tropical regions has been so wonderfully
increased in the present day by the zeal of botanical travelers. To these
groups succeed, in the Alpine valleys, and the humid and shaded clefts on
the slopes of the Cordilleras, the tree-ferns, whose thick cylindrical trunks
and delicate lace-like foliage stand out in bold relief against the azure of the
sky, and the cinchona, from which we derive the febrifuge bark. The
medicinal strength of this bark is said to increase in proportion to the degree

of moisture imparted to the foliage of the tree by the light mists which form
the upper surface of the clouds resting over the plains. Every where around,
the confines of the forest are encircled by broad bands of social plants, as
the delicate aralia, the thibaudia, and the myrtle-leaved Andromeda, while
the Alpine rose, the magnificent befaria, weaves a purple girdle round the
spiry peaks. In the cold regions of the Paramos, which is continually
exposed to the fury of storms and winds, we find that flowering shrubs and
herbaceous plants, bearing large and variegated blossoms, have given place
to monocotyledons, whose slender spikes constitute the sole covering of the
soil. This is the zone of the p 35 grasses, one vast savannah extending over
the immense mountain plateaux, and reflecting a yellow, almost golden
tinge, to the slopes of the Cordilleras, on which graze the lama and the
cattle domesticated by the European colonist. Where the naked trachyte
rock pierces the grassy turf, and penetrates into those higher strata of air
which are supposed to be less charged with carbonic acid, we meet only
with plants of an inferior organization, as lichens, lecideas, and the brightly-
colored, dust-like lepraria, scattered around in circular patches. Islets of
fresh-fallen snow, varying in form and extent, arrest the last feeble traces of
vegetable development, and to these succeeds the region of perpetual snow,
whose elevation undergoes but little change, and may be easily determined.
It is but rarely that the elastic forces at work within the interior of our globe
have succeeded in breaking through the spiral domes, which, resplendent in
the brightness of eternal snow, crown the summits of the Cordilleras; and
even where these subterranean forces have opened a permanent
communication with the atmosphere, through circular craters or long
fissures, they rarely send forth currents of lava, but merely eject ignited
scoriae, steam, sulphureted hydrogen gas, and jets of carbonic acid.

In the earliest stages of civilization, the grand and imposing spectacle
presented to the minds of the inhabitants of the tropics could only awaken
feelings of astonishment and awe. It might, perhaps, be supposed, as we

have already said, that the periodical return of the same phenomena, and the
uniform manner in which they arrange themselves in successive groups,
would have enabled man more readily to attain to a knowledge of the laws
of nature; but, as far as tradition and history guide us, we do not find that
any application was made of the advantages presented by these favored
regions. Recent researches have rendered it very doubtful whether the
primitive seat of Hindoo civilization — one of the most remarkable phases
in the progress of mankind — was actually within the tropics. Airyana
Vaedjo, the ancient cradle of the Zend, was situated to the northwest of the
upper Indus, and after the great religious schism, that is to say, after the
separation of the Iranians from the Brahminical institution, the language
that had previously been common to them and to the Hindoos assumed
among the latter people (together with the literature, habits, and conditions
of society) an individual form in the Magodha of Madhya Desa,* a district
that is bounded by the great chain p 36 of Himalaya and the smaller range
of the Vindhya.

[footnote] *See, on the Madhjadeca, properly so called, Lassen's
excellent work, entitled 'Indische Alterthumskunde', bd. i., s. 92. The
Chinese give the name of Mo-kie-thi to the southern Bahar, situated to the
south of the Ganges (see 'Foe-Koue-Ki' by, 'Chy-Fa-Hian', 1836, p. 256).
Djambu-dwipa is the name given to the whole of India; but the words also
indicate one of the four Buddhist continents.

In less ancient times the Sanscrit language and civilization advanced
toward the southeast, penetrating further within the torrid zone, as my
brother Wilhelm von Humboldt has shown in his great work on the Kavi
and other languages of analogous structure.*

[Footnote] *'Ueber die Kawi Sprache auf der Insel Java, nebst einer
Einleitung uber die Verschiedenheit des menschlichen Sprachbaues und
ihren
Ein fluss auf die geistige Entwickelung des Menschengrshlecht's' von
Wilhelm
v. Humboldt, 1836, bd. i., s. 50519.

Notwithstanding the obstacles opposed in northern latitudes to the
discovery of the laws of nature, owing to the excessive complication of
phenomena, and the perpetual local variations and the distribution of
organic forms, it is to the inhabitants of a small section of the temperate
zone that the rest of mankind owe the earliest revelation of an intimate and
rational acquaintance with the forces governing the physical world.
Moreover, it is from the same zone (which is apparently more favorable to
the progress of reason, the softening of manners, and the security of public
liberty) that the germs of civilization have been carried to the regions of the
tropics, as much by the migratory movement of races as by the
establishment of colonies, differing widely in their institution from those of
the Phoenicians or Greeks.

In speaking of the influence exercised by the succession of phenomena
on the greater or lesser facility of recognizing the causes producing them, I
have touched upon that important stage of our communion with the external
world, when the enjoyment arising from a knowledge of the laws, and the
mutual connection of phenomena, associates itself with the charm of a
simple contemplation of nature. That which for a long time remains merely
an object of vague intuition, by degrees acquires the certainty of positive
truth; and man, as an immortal poet has said, in our own tongue — Amid
ceaseless change seeks the unchanging pole.*

[Footnote] *This verse occurs in a poem of Schiller, entitled 'Der
Spaziergang' which first appeared in 1795, in the 'Horen.'

In order to trace to its primitive source the enjoyment derived from the
exercise of thought, it is sufficient to cast a rapid glance on the earliest
dawnings of the philosophy of nature, or of the ancient doctrine of the
'Cosmos.' We find even p 37 among the most savage nations (as my own
travels enable me to attest) a certain vague, terror-stricken sense of the all-
powerful unity of natural forces, and of the existence of an invisible,
spiritual essence manifested in these forces, whether in unfolding the flower
and maturing the fruit of the nutrient tree, in upheaving the soil of the
forest, or in rending the clouds with the might of the storm. We may here
trace the revelation of a bond of union, linking together the visible world
and that higher spiritual world which escapes the grasp of the senses. The
two become unconsciously blended together, developing in the mind of
man, as a simple product of ideal conception and independently of the aid
of observation, the first germ of a 'Philosophy of Nature.'

Among nations least advanced in civilization, the imagination revels in
strange and fantastic creations, and, by its predilection for symbols, alike
influences ideas and language. Instead of examining, men are led to
conjecture, dogmatize, and interpret supposed facts that have never been
observed. The inner world of thought and of feeling does not reflect the
image of the external world in its primitive purity. That which in some
regions of the earth manifested itself as the rudiments of natural philosophy,
only to a small number of persons endowed with superior intelligence,
appears in other regions, and among entire races of men, to be the result of
mystic tendencies and instinctive intuitions. An intimate communion with
nature, and the vivid and deep emotions thus awakened, are likewise the
source from which have sprung the first impulses toward the worship and

deification of the destroying and preserving forces of the universe. But by
degrees, as man, after having passed through the different gradations of
intellectual development, arrives at the free enjoyment of the regulating
power of reflection, and learns by gradual progress, as it were, to separate
the world of ideas from that of sensations, he no longer rests satisfied
merely with a vague presentiment of the harmonious unity of natural forces;
thought begins to fulfill its noble mission; and observation, aided by reason,
endeavors to trace phenomena to the causes from which they spring.

The history of science teaches us the difficulties that have opposed the
progress of this active spirit of inquiry. Inaccurate and imperfect
observations have led, by false inductions, to the great number of physical
views that have been perpetuated as popular prejudices among all classes of
society. Thus by the side of a solid and scientific knowledge of natural
phenomena there has been preserved a system of the pretended p 38 results
of observation, which is so much the more difficult to shake, as it denies the
validity of the facts by which it may be refuted. This empiricism, the
melancholy heritage transmitted to us from former times, invariably
contends for the truth of its axioms with the arrogance of a narrow-minded
spirit. Physical philosophy, on the other hand, when based upon science,
doubts because it seeks to investigate, distinguishes between that which is
certain and that which is merely probable, and strives incessantly to perfect
theory by extending the circle of observation.

This assemblage of imperfect dogmas, bequeathed by one age to another
— this physical philosophy, which is composed of popular prejudices — is
not only injurious because it perpetuates error with the obstinacy
engendered by the evidence of ill-observed facts, but also because it hinders
the mind from attaining to higher views of nature. Instead of seeking to
discover the 'mean' or 'medium' point, around which oscillate, in apparent
independence of forces, all the phenomena of the external world, this

system delights in multiplying exceptions to the law, and seeks, amid
phenomena and in organic forms for something beyond the marvel of a
regular succession, and an internal and progressive development. Ever
inclined to believe that the order of nature is disturbed, it refuses to
recognize in the present any analogy with the past, and guided by its own
varying hypotheses, seeks at hazard, either in the interior of the globe or in
the regions of space, for the cause of these pretended perturbations.

It is the special object of the present work to combat those errors which
derive their source from a vicious empiricism and from imperfect
inductions. The higher enjoyments yielded by the study of nature depend
upon the correctness and the depth of our views, and upon the extent of the
subjects that may be comprehended in a single glance. Increased mental
cultivation has given rise, in all classes of society, to an increased desire of
embellishing life by augmenting the mass of ideas, and by multiplying
means for their generalization; and this sentiment fully refutes the vague
accusations advanced against the age in which we live, showing that other
interests, besides the material wants of life, occupy the minds of men.

It is almost with reluctance that I am about to speak of a sentiment, which
appears to arise from narrow-minded views, or from a certain weak and
morbid sentimentality — I allude to the 'fear' entertained by some persons,
that nature may by degrees lose a portion of the charm and magic of her
power, p 39 as we learn more and more how to unvail her secrets,
comprehend the mechanism of the movements of the heavenly bodies, and
estimate numerically the intensity of natural forces. It is true that, properly
speaking, the forces of nature can only exercise a magical power over us as
long as their action is shrouded in mystery and darkness, and does not admit
of being classed among the conditions with which experience has made us
acquainted. The effect of such a power is, therefore, to excite the
imagination, but that, assuredly, is not the faculty of mind we would evoke

to preside over the laborious and elaborate observations by which we strive
to attain to a knowledge of the greatness and excellence of the laws of the
universe.

The astronomer who, by the aid of the heliometer or a double-refracting
prism,* determines the diameter of planetary bodies; who measures
patiently year after year, the meridian altitude and the relative distances of
stars, or who seeks a telescopic comet in a group of nebulae, does not feel
his imagination more excited — and this is the very guarantee of the
precision of his labors — than the botanist who counts the divisions of the
calyx, or the number of stamens in a flower, or examines the connected or
the separate teeth of the peristoma surrounding the capsule of a moss. Yet
the multiplied angular measurements on the one hand, and the detail of
organic relations on the other, alike aid in preparing the way for the
attainment of higher views of the laws of the universe.

[Footnote] *Arago's ocular micrometer, a happy improvement upon
Rochon's prismatic or double-refraction micrometer. See M. Mathieu's note
in Delambre's 'Histoire de l'Astronomie au dix-huitieme Siecle', 1827.

We must not confound the disposition of mind in the observer at the time
he is pursuing his labors, with the ulterior greatness of the views resulting
from investigation and the exercise of thought. The physical philosopher
measures with admirable sagacity the waves of light of unequal length
which by interference mutually strengthen or destroy each other, even with
respect to their chemical actions; the astronomer, armed with powerful
telescopes, penetrates the regions of space, contemplates, on the extremest
confines of our solar system, the satellites of Uranus, or decomposes faintly
sparkling points into double stars differing in color. The botanist discovers
the constancy of the gyratory motion of the chara in the greater number of

vegetable cells, and recognizes in the genera and natural families of plants
the intimate relations or organic forms. The vault of heaven, studded with
nebulae p 40 and stars, and the rich vegetable mantle that covers the soil in
the climate of palms, can not surely fail to produce on the minds of these
laborious observers of nature an impression more imposing and more
worthy of the majesty of creation than on those who are unaccustomed to
investigate the great mutual relations of phenomena. I can not, therefore,
agree with Burke when he says, "it is our ignorance of natural things that
causes all our admiration and chiefly excites our passions."

While the illusion of the senses would make the stars stationary in the
vault of heaven, Astronomy, by her aspiring labors, has assigned indefinite
bounds to space; and if she have set limits to the great nebula to which our
solar system belongs, it has only been to show us in those remote regions of
our optic powers, islet on islet of scattered nebulae. The feeling of the
sublime, so far as it arises from a contemplation of the distance of the stars,
of their greatness and physical extent, reflects itself in the feeling of the
infinite, which belongs to another sphere of ideas included in the domain of
mind. The solemn and imposing impressions excited by this sentiment are
owing to the combination of which we have spoken, and to the analogous
character of the enjoyment and emotions awakened in us, whether we float
on the surface of the great deep, stand on some lonely mountain summit
enveloped in the half-transparent vapory vail of the atmosphere, or by the
aid of powerful optical instruments scan the regions of space, and see the
remote nebulous mass resolve itself into worlds of stars.

The mere accumulation of unconnected observations of details, devoid of
generalization of ideas, may doubtlessly have tended to create and foster the
deeply-rooted prejudice, that the study of the exact sciences must
necessarily chill the feelings, and diminish the nobler enjoyments attendant
upon a contemplation of nature. Those who still cherish such erroneous

views in the present age, and amid the progress of public opinion, and the
advancement of all branches of knowledge, fail in duly appreciating the
value of every enlargement of the sphere of intellect, and the importance of
the detail of isolated facts in leading us on to general results. The fear of
sacrificing the free enjoyment of nature, under the influence of scientific
reasoning, is often associated with an apprehension that every mind may
not be capable of grasping the truths of the philosophy of nature. It is
certainly true that in the midst of the universal fluctuation of phenomena
and vital p 41 forces — in that inextricable net-work of organisms by turns
developed and destroyed — each step that we make in the more intimate
knowledge of nature leads us to the entrance of new labyrinths; but the
excitement produced by a presentiment of discovery, the vague intuition of
the mysteries to be unfolded, and the multiplicity of the paths before us, all
tend to stimulate the exercise of thought in every stage of knowledge. The
discovery of each separate law of nature leads to the establishment of some
other more general law, or at least indicates to the intelligent observer its
existence. Nature, as a celebrated physiologist* has defined it, and as the
word was interpreted by the Greeks and Romans, is "that which is ever
growing and ever unfolding itself in new forms."

[Footnote] *Carus, 'Von den Urtheilen des Knochen und Schalen
Gerustes', 1828 6.

The series of organic types becomes extended or perfected in proportion
as hitherto unknown regions are laid open to our view by the labors and
researches of travelers and observers; as living organisms are compared
with those which have disappeared in the great revolutions of our planet;
and as microscopes are made more perfect, and are more extensively and
efficiently employed. In the midst of this immense variety, and this periodic
transformation of animal and vegetable productions, we see incessantly

revealed the primordial mystery of all organic development, that same great
problem of 'metamorphosis' which Göthe has treated with more than
common sagacity, and to the solution of which man is urged by his desire of
reducing vital forms to the smallest number of fundamental types. As men
contemplate the riches of nature, and see the mass of observations
incessantly increasing before them, they become impressed with the
intimate conviction that the surface and the interior of the earth, the depths
of the ocean, and the regions of air will still, when thousands and thousands
of years have passed away, open to the scientific observer untrodden paths
of discovery. The regret of Alexander can not be applied to the progress of
observation and intelligence.*

[footnote] * Plut., in 'Vita Alex. Magni', cap. 7

General considerations, whether they treat of the agglomeration of matter
in the heavenly bodies, or of the geographical distribution of terrestrial
organisms, are not only in themselves more attractive than special studies,
but they also afford superior advantages to those who are unable to devote
much time to occupations of this nature. The different branches of the study
of natural history are only accessible in certain positions of social life, and
do not, at every season p 42 and in every climate, present like enjoyments.
Thus, in the dreary regions of the north, man is deprived for a long period
of the year of the spectacle presented by the activity of the productive
forces of organic nature; and if the mind be directed to one sole class of
objects, the most animated narratives of voyages in distant lands will fail to
interest and attract us, if they do not touch upon the subjects to which we
are most partial.

As the history of nations — if it were always able to trace events to their
true causes — might solve the ever-recurring enigma of the oscillations

experienced by the alternately progressive and retrograde movement of
human society, so might also the physical description of the world, the
science of the 'Cosmos', if it were grasped by a powerful intellect, and
based upon a knowledge of all the results of discovery up to a given period,
succeed in dispelling a portion of the contradictions which, at first sight,
appear to arise from the complication or phenomena and the multitude of
the perturbations simultaneously manifested.

The knowledge of the laws of nature, whether we can trace them in the
alternate ebb and flow of the ocean, in the measured path of comets, or in
the mutual attractions of multiple stars, alike increases our sense of the calm
of nature, while the chimera so long cherished by the human mind in its
early and intuitive contemplations, the belief in a "discord of the elements,"
seems gradually to vanish in proportion as science extends her empire.
General views lead us habitually to consider each organism as a part of the
entire creation, and to recognize in the plant or the animal not merely an
isolated species, but a form linked in the chain of being to other forms
either living or extinct. They aid us in comprehending the relations that
exist between the most recent discoveries and those which have prepared
the way for them. Although fixed to one point of space, we eagerly grasp at
a knowledge of that which has been observed in different and far-distant
regions. We delight in tracking the course of the bold mariner through seas
of polar ice, or in following him to the summit of that volcano of the
antarctic pole, whose fires may be seen from afar, even at mid-day. It is by
an acquaintance with the results of distant voyages that we may learn to
comprehend some of the marvels of terrestrial magnetism, and be thus led
to appreciate the importance of the establishments of the numerous
observatories which in the present day cover both hemispheres, and are
designed to note p 43 the simultaneous occurrence of perturbations, and the
frequency and duration of 'magnetic storms.'

Let me be permitted here to touch upon a few points connected with
discoveries, whose importance can only be estimated by those who have
devoted themselves to the study of the physical sciences generally.
Examples chosen from among the phenomena to which special attention
has been directed in recent times, will throw additional light upon the
preceding considerations. Without a preliminary knowledge of the orbits of
comets, we should be unable duly to appreciate the importance attached to
the discovery of one of these bodies, whose elliptical orbit is included in the
narrow limits of our solar system, and which has revealed the existence of
an ethereal fluid, tending to diminish its centrifugal force and the period of
its revolution.

The superficial half-knowledge, so characteristic of the present day,
which leads to the introduction of vaguely comprehended scientific views
into general conversation, also gives rise, under various forms, to the
expression of alarm at the supposed danger of a collision between the
celestial bodies, or of disturbance in the climatic relations of our globe.
These phantoms of the imagination are so much the more injurious as they
derive their source from dogmatic pretensions to true science. The history
of the atmosphere, and of the annual variations of its temperature, extends
already sufficiently far back to show the recurrence of slight disturbances in
the mean temperature of any given place, and thus affords sufficient
guarantee against the exaggerated apprehension of a general and
progressive deterioration of the climates of Europe. Encke's comet, which is
one of the three 'interior comets', completes its course in 1200 days, but
from the form and position of its orbit it is as little dangerous to the earth as
Halley's great comet, whose revolution is not completed in less than
seventy-six years (and which appeared less brilliant in 1835 than it had
done in 1759): the interior comet of Biela intersects the earth's orbit, it is
true, but it can only approach our globe when its proximity to the sun
coincides with our winter solstice.

The quantity of heat received by a planet, and whose unequal distribution
determines the meteorological variations of its atmosphere, depends alike
upon the light-engendering force of the sun; that is to say, upon the
condition of its gaseous coverings, and upon the relative position of the
planet and the central body.

p 44 There are variations, it is true, which, in obedience to the laws of
universal gravitation, affect the form of the earth's orbit and the inclination
of the ecliptic, that is, the angle which the axis of the earth makes with the
plane of its orbit; but these periodical variations are so slow, and are
restricted within such narrow limits, that their thermic effects would hardly
be appreciable by our instruments in many thousands of years. The
astronomical causes of a refrigeration of our globe, and of the diminution of
moisture at its surface, and the nature and frequency of certain epidemics —
phenomena which are often discussed in the present day according to the
benighted views of the Middle Ages — ought to be considered as beyond
the range of our experience in physics and chemistry.

Physical astronomy presents us with other phenomena, which can not be
fully comprehended in all their vastness without a previous acquirement of
general views regarding the forces that govern the universe. Such, for
instance, are the innumerable double stars, or rather suns, which revolve
round one common center of gravity, and thus reveal in distant worlds the
existence of the Newtonian law; the larger or smaller number of spots upon
the sun, that is to say, the openings formed through the luminous and
opaque atmosphere surrounding the solid nucleus; and the regular
appearance about the 13th of November and the 11th of August, of shooting
stars, which probably form part of a belt of asteroids, intersecting the earth's
orbit, and moving with planetary velocity.

Descending from the celestial regions to the earth, we would fain inquire
into the relations that exist between the oscillations of the pendulum in air
(the theory of which has been perfected by Bessel) and the density of our
planet; and how the pendulum, acting the part of a plummet, can, to a
certain extent, throw light upon the geological constitution of strata at great
depths? By means of this instrument we are enabled to trace the striking
analogy which exists between the formation of the granular rocks
composing the lava currents ejected from active volcanoes, and those
endogenous masses of granite, porphyry, and serpentine, which, issuing
from the interior of the earth, have broken, as eruptive rocks, through the
secondary strata, and modified them by contact, either in rendering them
harder by the introduction of silex, or reducing them into dolomite, or,
finally, by inducing within them the formation of crystals of the most varied
composition. The elevation of sporadic islands, of p 45 domes of trachyte,
and cones of basalt, by the elastic forces emanating from the fluid interior
of our globe, has led one of the first geologists of the age, Leopold von
Buch, to the theory of the elevation of continents, and of mountain chains
generally. This action of subterranean forces in breaking through and
elevating strata of sedimentary rocks, of which the coast of Chili, in
consequence of a great earthquake, furnished a recent example, leads to the
assumption that the pelagic shells found by M. Bonpland and myself on the
ridge of the Andes, at an elevation of more than 15,000 English feet, may
have been conveyed to so extraordinary a position, not by a rising of the
ocean, but by the agency of volcanic forces capable of elevating into ridges
the softened crust of the earth.

I apply the term 'volcanic', in the widest sense of the word, to every
action exercised by the interior of a planet on its external crust. The surface
of our globe, and that of the moon, manifest traces of this action, which in
the former, at least, has varied during the course of ages. Those who are
ignorant of the fact that the internal heat of the earth increases so rapidly

with the increase of depth that granite is in a state of fusion about twenty or
thirty geographical miles below the surface,* can not have a clear
conception of the causes, and the simultaneous occurrence of volcanic
eruptions at places widely removed from one another, or of the extent and
intersection of 'circles of commotion' in earthquakes, or of the uniformity of
temperature, and equality of chemical composition observed in thermal
springs during a long course of years.

[Footnote] * The determinations usually given of the point of fusion are
in general much too high for refracting substances. According to the very
accurate researches of Mitscherlich, the melting point of granite can hardly
exceed 2372 degrees F. [Dr. Mantell states in 'The Wonders of Geology',
1848, vol. i., p. 34, that this increase of temperature amounts to 1 degree of
Fahrenheit for every fifty-four feet of vertical depth.] — Tr.

The quantity of heat peculiar to a planet is, however, a matter of such
importance — being the result of its primitive condensation, and varying
according to the nature and duration of the radiation — that the study of this
subject may throw some degree of light on the history of the atmosphere,
and the distribution of the organic bodies imbedded in the solid crust of the
earth. This study enables us to understand how a tropical temperature,
independent of latitude (that is, of the distance from the poles), may have
been produced by deep fissures remaining open, and exhaling heat from the
interior p 46 of the globe, at a period when the earth's crust was still
furrowed and rent, and only in a state of semi-solidification; and a
primordial condition is thus revealed to us, in which the temperature of the
atmosphere, and climates generally, were owing rather to a liberation of
caloric and of different gaseous emanations (that is to say, rather to the
energetic reaction of the interior on the exterior) than to the position of the
earth with respect to the central body, the sun.

The cold regions of the earth contain, deposited in sedimentary strata, the
products of tropical climates; thus, in the coal formations, we find the
trunks of palms standing upright amid coniferae, tree ferns, goniatites, and
fishes having rhomboidal osseous scales;* in the Jura limestone, colossal
skeletons of crocodiles, plesiosauri, planulites, and stems of the cycadeae;
in the chalk formations, small polythalmia and bryozoa, whose species still
exist in our seas; in tripoli, or polishing slate, in the semi-opal and the
farina-like opal or mountain meal, agglomerations of siliceous infusoria,
which have been brought to light by the powerful microscope of
Ehrenberg;** and, lastly, in transported soils, and in certain caves, the
bones of elephants, hyenas, and lions.

[Footnote] *See the classical work on the fishes of the Old World by
Agassiz, 'Rech. sur les Poissons Fossiles', 1834, vol. i., p. 38; vol. ii., p. 3,
28, 34, App., p. 6. The whole genus of Amblypterus, Ag., nearly allied to
Palaeoniscus (called also Palaeothrissum), lies buried beneath the Jura
formations in the old carboniferous strata. Scales which, in some fishes, as
in the family of Lepidoides (order of Ganoides), are formed like teeth, and
covered in certain parts with enamel, belong, after the Placoides, to the
oldest forms of fossil fishes; their living representatives are still found in
two genera, the 'Bichir' of the Nile and Senegal, and the 'Lepidosteus' of the
Ohio.

[Footnote] **[The 'polishing slate' of Bilin is stated by M. Ehrenberg to
form a 'series' of strata fourteen feet in thickness, entirely made up of the
siliceous shells of 'Gaillonellae', of such extreme minuteness that a cubic
inch of the stone contains forty-one thousand millions! The 'Bergmehl'
('mountain meal' or 'fossil farina') of San Fiora, in Tuscany, is one mass of
animalculites. See the interesting work of G. A. Mantell, 'On the Medals of
Creation', vol. i., p. 233.] — Tr.

An intimate acquaintance with the physical phenomena of the universe
leads us to regard the products of warm latitudes that are thus found in a
fossil condition in northern regions not merely as incentives to barren
curiosity, but as subjects awakening deep reflection, and opening new
sources of study.

The number and the variety of the objects I have alluded to give rise to
the question whether general considerations of physical phenomena can be
made sufficiently clear to persons who have not acquired a detailed and
special knowledge of p 47 descriptive natural history, geology, or
mathematical astronomy? I think we ought to distinguish here between him
whose task it is to collect the individual details of various observations, and
study the mutual relations existing among them, and him to whom these
relations are to be revealed, under the form of general results. The former
should be acquainted with the specialities of phenomena, that he may arrive
at a generalization of ideas as the result, at least in part, of his own
observations, experiments, and calculations. It can not be denied, that where
there is an absence of positive knowledge of physical phenomena, the
general results which impart so great a charm to the study of nature can not
all be made equally clear and intelligible to the reader, but still I venture to
hope, that in the work which I am now preparing on the physical laws of the
universe, the greater part of the facts advanced can be made manifest
without the necessity of appealing to fundamental views and principles. The
picture of nature thus drawn, notwithstanding the want of distinctness of
some of its outlines, will not be the less able to enrich the intellect, enlarge
the sphere of ideas, and nourish and vivify the imagination.

There is, perhaps, some truth in the accusation advanced against many
German scientific works, that they lessen the value of general views by an
accumulation of detail, and do not sufficiently distinguish between those
great results which form, as it were, the beacon lights of science, and the

long series of means by which they have been attained. This method of
treating scientific subjects led the most illustrious of our poets* to exclaim
with impatience, "The Germans have the art of making science
inaccessible." An edifice can not produce a striking effect until the
scaffolding is removed, that had of necessity been used during its erection.

[Footnote] *Gothe, in 'Die Aphorismen uber Naturwissenschaft', bd. I., s.
155 ('Werke kleine Ausgabe','von' 1833.)

Thus the uniformity of figure observed in the distribution of continental
masses, which all terminate toward the south in a pyramidal form, and
expand toward the north (a law that determines the nature of climates, the
direction of currents in the ocean and the atmosphere, and the transition of
certain types of tropical vegetation toward the southern temperate zone),
may be clearly apprehended without any knowledge of the geodesical and
astronomical operations by means of which these pyramidal forms of
continents have been determined. In like manner, physical geography
teaches us by how many leagues p 48 the equatorial axis exceeds the polar
axis of the globe, and shows us the mean equality of the flattening of the
two hemispheres, without entailing on us the necessity of giving the detail
of the measurement of the degrees in the meridian, or the observations on
the pendulum, which have led us to know that the true figure of our globe is
not exactly that of a regular ellipsoid of revolution, and that this irregularity
is reflected in the corresponding irregularity of the movements of the moon.

The views of comparative geography have been specially enlarged by
that admirable work, 'Erdkunde im Verhältniss zur Natur und sur
Geschichte', in which Carl Ritter so ably delineates the physiognomy of our
globe, and shows the influence of its external configuration on the physical
phenomena on its surface, on the migrations, laws, and manners of nations,
and on all the principal historical events enacted upon the face of the earth.

France possesses an immortal work, 'L'Exposition du Système du
Monde', in which the author has combined the results of the highest
astronomical and mathematical labors, and presented them to his readers
free from all processes of demonstration. The structure of the heavens is
here reduced to the simple solution of a great problem in mechanics; yet
Laplace's work has never yet been accused of incompleteness and want of
profundity.

The distinction between dissimilar subjects, and the separation of the
general from the special, are not only conducive to the attainment of
perspicuity in the composition of a physical history of the universe, but are
also the means by which a character of greater elevation may be imparted to
the study of nature. By the suppression of all unnecessary detail, the great
masses are better seen, and the reasoning faculty is enabled to grasp all that
might otherwise escape the limited range of the senses.

The exposition of general results has, it must be owned, been singularly
facilitated by the happy revolution experienced since the close of the last
century, in the condition of all the special sciences, more particularly of
geology, chemistry, and descriptive natural history. In proportion as laws
admit of more general application, and as sciences mutually enrich each
other, and by their extension become connected together in more numerous
and more intimate relations, the development of general truths may be
given with conciseness devoid of superficiality. On being first examined, all
phenomena appear to be p 49 isolated, and it is only by the result of a
multiplicity of observations, combined by reason, that we are able to trace
the mutual relations existing between them. If, however, in the present age,
which is so strongly characterized by a brilliant course of scientific
discoveries, we perceive a want of connection in the phenomena of certain
sciences, we may anticipate the revelation of new facts, whose importance
will probably be commensurate with the attention directed to these branches

of study. Expectations of this nature may be entertained with regard to
meteorology, several parts of optics, and to radiating heat, and electro-
magnetism, since the admirable discoveries of Melloni and Faraday. A
fertile field is here opened to discovery, although the voltaic pile has
already taught us the intimate connection existing between electric,
magnetic, and chemical phenomena. Who will venture to affirm that we
have any precise knowledge, in the present day, of that part of the
atmosphere which is not oxygen, or that thousands of gaseous substances
affecting our organs may not be mixed with the nitrogen, or, finally, that we
have even discovered the whole number of the forces which pervade the
universe?

It is not the purpose of this essay on the physical history of the world to
reduce all sensible phenomena to a small number of abstract principles,
based on reason only. The physical history of the universe, whose
exposition I attempt to develop, does not pretend to rise to the perilous
abstractions of a purely rational science of nature, and is simply a 'physical
geography, combined with a description of the regions of space and the
bodies occupying them.' Devoid of the profoundness of a purely speculative
philosophy, my essay on the 'Cosmos' treats of the contemplation of the
universe, and is based upon a rational empiricism, that is to say, upon the
results of the facts registered by science, and tested by the operations of the
intellect. It is within these limits alone that the work, which I now venture
to undertake, appertains to the sphere of labor to which I have devoted
myself throughout the course of my long scientific career. The path of
inquiry is not unknown to me, although it may be pursued by others with
greater success. The unity which I seek to attain in the development of the
great phenomena of the universe, is analogous to that which historical
composition is capable of acquiring. All points relating to the accidental
individualities, and the essential variations of the actual, whether in the
form and arrangement of natural objects in the struggle of man against the

elements, or of nations against nations, do not admit of being p 50 based
only on a 'rational foundation' — that is to say, of being deduced from ideas
alone.

It seems to me that a like degree of empiricism attaches to the
Description of the Universe and to Civil History; but in reflecting upon
physical phenomena and events, and tracing their causes by the process of
reason, we become more and more convinced of the truth of the ancient
doctrine, that the forces inherent in matter, and those which govern the
moral necessity, and in accordance with movements occurring periodically
after longer or shorter intervals.

It is this necessity, this occult but permanent connection, this periodical
recurrence in the progressive development of forms, phenomena, and
events, which constitute 'nature', obedient to the first impulse imparted to it.
Physics, as the term signifies, is limited to the explanation of the
phenomena of the material world by the properties of matter. The ultimate
object of the experimental sciences is, therefore, to discover laws, and to
trace their progressive generalization. All that exceeds this goes beyond the
province of the physical description of the universe, and appertains to a
range of higher speculative views.

Emmanuel Kant, one of the few philosophers who have escaped the
imputation of impiety, has defined with rare sagacity the limits of physical
explanations, in his celebrated essay 'On the Theory and Structure of the
Heavens', published at Konigsberg in 1755.

The study of a science that promises to lead us through the vast range of
creation may be compared to a journey in a far-distant land. Before we set
forth, we consider, and often with distrust, our own strength, and that of the
guide we have chosen. But the apprehensions which have originated in the
abundance and the difficulties attached to the subjects we would embrace,

recede from view as we remember that with the increase of observations in
the present day there has also arisen a more intimate knowledge of the
connection existing among all phenomena. It has not unfrequently
happened, that the researches made at remote distances have often and
unexpectedly thrown light upon subjects which had long resisted the
attempts made to explain them within the narrow limits of our own sphere
of observation. Organic forms that had long remained isolated, both in the
animal and vegetable kingdom, have been connected by the discovery of
intermediate links or stages of transition. The geography of beings endowed
p 51 with life attains completeness as we see the species, genera, and entire
families belonging to one hemisphere, reflected as it were, in analogous
animal and vegetable forms in the opposite hemisphere. There are, so to
speak, the 'equivalents' which mutually personate and replace one another
in the great series of organisms. These connecting links and stages of
transition may be traced, alternately, in a deficiency or an excess of
development of certain parts, in the mode of junction of distinct organs, in
the differences in the balance of forces, or in a resemblance to intermediate
forms which are not permanent, but merely characteristic of certain phases
of normal development. Passing from the consideration of beings endowed
with life to that of inorganic bodies, we find many striking illustrations of
the high state of advancement to which modern geology has attained. We
thus see, according to the grand views of Elie de Beaumont, how chains of
mountains dividing different climates and floras and different races of men,
reveal to us their 'relative age', both by the character of the sedimentary
strata they have uplifted, and by the directions which they follow over the
long fissures and which the earth's crust is furrowed. Relations of
superposition of trachyte and of syenitic porphyry, of diorite and of
serpentine, which remain in the rich platinum districts of the Oural, and on
the south-western declivity of the Siberian Alti, are elucidated by the
observations that have been made on the plateaux of Mexico and Antioquia,

and in the unhealthy ravines of Choco. The most important facts on which
the physical history of the world has been based in modern times, have not
been accumulated by chance. It has at length been fully acknowledged, and
the conviction is characteristic of the age, that the narratives of distant
travels, too long occupied in the mere recital of hazardous adventures, can
only be made a source of instruction where the traveler is acquainted with
the condition of the science he would enlarge, and is guided by reason in his
researches.

It is by this tendency to generalization, which is only dangerous in its
abuse, that a great portion of the physical knowledge already acquired may
be made the common property of all classes of society; but, in order to
render the instruction impaired by these means commensurate with the
importance of the subject, it is desirable to deviate as widely as possible
from the imperfect compilations designated, till the close of the eighteenth
century, by the inappropriate term of 'popular p 52 knowledge.' I take
pleasure in persuading myself that scientific subjects may be treated of in
language at once dignified, grave, and animated, and that those who are
restricted within the circumscribed limits of ordinary life, and have long
remained strangers to an intimate communion with nature, may thus have
opened to them one of the richest sources of enjoyment, by which the mind
is invigorated by the acquisition of new ideas. Communion with nature
awakens within us perceptive faculties that had long lain dormant; and we
thus comprehend at a single glance the influence exercised by physical
discoveries on the enlargement of the sphere of intellect, and perceive how
a judicious application of mechanics, chemistry, and other sciences may be
made conducive to national prosperity.

A more accurate knowledge of the connection of physical phenomena
will also tend to remove the prevalent error that all branches of natural
science are not equally important in relation to general cultivation and

industrial progress. An arbitrary distinction is frequently made between the
various degrees of importance appertaining to mathematical sciences, to the
study of organized beings, the knowledge of electro-magnetism, and
investigations of the general properties of matter in its different conditions
of molecular aggregation; and it is not uncommon presumptuously to affix a
supposed stigma upon researches of this nature, by terming them "purely
theoretical," forgetting , although the fact has been long attested, that in the
observation of a phenomenon, which at first sight appears to be wholly
isolated, may be concealed the germ of a great discovery. When Aloysio
Galvani first stimulated the nervous fiber by the accidental contact of two
heterogeneous metals, his contemporaries could never have anticipated that
the action of the voltaic pile would discover to us, in the alkalies, metals of
a silvery luster, so light as to swim on water, and eminently inflammable; or
that it would become a powerful instrument of chemical analysis, and at the
same time a thermoscope and a magnet. When Hygens first observed, in
1678, the phenomenon of the polarization of light, exhibited in the
difference between the two rays into which a pencil of light divides itself in
passing through a doubly refracting crystal, it could not have been foreseen
that, a century and a half later, the great philosopher Arago would, by his
discovery of 'chromatic polarization', be led to discern, by means of a small
fragment of Iceland spar, whether solar light emanates from a solid body or
a gaseous covering, or p 53 whether comets transmit light directly or merely
by reflection.*

[Footnote] *Arago's Discoveries in the year 1811. — Delambro's
'Histoire de l'Ast.', p. 652. (Passage already quoted.)

An equal appreciation of all branches of the mathematical, physical, and
natural sciences is a special requirement of the present age, in which the
material wealth and the growing prosperity of nations are principally based

upon a more enlightened employment of the products and forces of nature.
The most superficial glance at the present condition of Europe shows that a
diminution, or even a total annihilation of national prosperity, must be the
award of those states who shrink with slothful indifference from the great
struggle of rival nations in the career of the industrial arts. It is with nations
as with nature, which, according to a happy expression of Göthe,* "knows
no pause in progress and development, and attaches her curse on all
inaction."

[Footnote] *Gothe, in 'Die Aphorismen uber Naturwissenschaft.' —
'Werke', bd. 1., s. 4

The propagation of an earnest and sound knowledge of science can
therefore alone avert the dangers of which I have spoken. Man can not act
upon nature, or appropriate her forces to his own use, without
comprehending their full extent, and having an intimate acquaintance with
the laws of the physical world. Bacon has said that, in human societies,
knowledge is power. Both must rise and sink together. But the knowledge
that results from the free action of thought is at once the delight and the
indestructible prerogative of man; and in forming part of the wealth of
mankind, it not unfrequently serves as a substitute for the natural riches,
which are but sparingly scattered over the earth. Those states which take no
active part in the general industrial movement, in the choice and preparation
of natural substances, or in the application of mechanics and chemistry, and
among whom this activity is not appreciated by all classes of society, will
infallibly see their prosperity diminish in proportion as neighboring
countries become strengthened and invigorated under the genial influence
of arts and sciences.

As in nobler spheres of thought and sentiment, in philosophy, poetry, and
the fine arts, the object at which we aim ought to be an inward one — an
ennoblement of the intellect — so ought we likewise in our pursuit of
science, to strive after a knowledge of the laws and the principles of unity
that pervade the vital forces of the universe; and it is by such a course that p
54 physical studies may be made subservient to the progress of industry,
which is a conquest of mind over matter. By a happy connection of causes
and effects, we often see the useful linked to the beautiful and the exalted.
The improvement of agriculture in the hands of freemen, and on properties
of a moderate extent — the flourishing state of the mechanical arts freed
from the trammels of municipal restrictions — the increased impetus
imparted to commerce by the multiplied means of the intellectual progress
of mankind, and of the amelioration of political institutions, in which this
progress is reflected. The picture presented by modern history ought to
convince those who are tardy in awakening to the truth of the lesson it
teaches.

Nor let it be feared that the marked predilection for the study of nature,
and for industrial progress, which is so characteristic of the present age,
should necessarily have a tendency to retard the noble exertions of the
intellect in the domains of philosophy, classical history, and antiquity, or to
deprive the arts by which life is embellished of the vivifying breath of
imagination. Where all the germs of civilization are developed beneath the
aegis of free institutions and wise legislation, there is no cause for
apprehending that any one branch of knowledge should be cultivated to the
prejudice of others. All afford the state precious fruits, whether they yield
nourishment to man and constitute his physical wealth, or whether, more
permanent in their nature, they transmit in the works of mind the glory of
nations to remotest posterity. The Spartans, notwithstanding their Doric
austerity, prayed the gods to grant them "the beautiful with the good."*

[Footnote] *Pseudo-Plato, — 'Alcib.', xi., p. 184, ed. Steph.; Plut.,
'Instituta Laconica', p. 253, ed. Hatten.

I will no longer dwell upon the considerations of the influence exercised
by the mathematical and physical sciences on all that appertains to the
material wants of social life, for the vast extent of the course on which I am
entering forbids me to insist further upon the utility of these applications.
Accustomed to distant excursions, I may, perhaps, have erred in describing
the path before us as more smooth and pleasant than it really is, for such is
wont to be the practice of those who delight in guiding others to the
summits of lofty mountains: they praise the view even when great part of
the distant plains lie hidden by clouds, knowing that this half-transparent
vapory vail imparts to the scene a certain charm from p 55 the power
exercised by the imagination over the domain of the senses. In like manner,
from the height occupied by the physical history of the world, all parts of
the horizon will not appear equally clear and well defined. This
indistinctness will not, however, be wholly owing to the present imperfect
state of some of the sciences, but in part, likewise, to the unskillfulness of
the guide who has imprudently ventured to ascend these lofty summits.

The object of this introductory notice is not, however, solely to draw
attention to the importance and greatness of the physical history of the
universe, for in the present day these are too well understood to be
contested, but likewise to prove how, without detriment to the stability of
special studies, we may be enabled to generalize our ideas by concentrating
them in one common focus, and thus arrive at a point of view from which
all the organisms and forces of nature may be seen as one living active
whole, animated by one sole impulse. "Nature," as Schelling remarks in his
poetic discourse on art, "is not an inert mass; and to him who can
comprehend her vast sublimity, she reveals herself as the creative force of

the universe — before all time, eternal, ever active, she calls to life all
things, whether perishable or imperishable."

By uniting, under one point of view, both the phenomena of our own
globe and those presented in the regions of space, we embrace the limits of
the science of the 'Cosmos', and convert the physical history of the globe
into the physical history of the universe, the one term being modeled upon
that of the other. This science of the Cosmos is not, however, to be regarded
as a mere encyclopedic aggregation of the most important and general
results that have been collected together from special branches of
knowledge. These results are nothing more than the materials for a vast
edifice, and their combination can not constitute the physical history of the
world, whose exalted part it is to show the simultaneous action and the
connecting links of the forces which pervade the universe. The distribution
of organic types in different climates and at different elevations — that is to
say, the geography of plants and animals — differs as widely from botany
and descriptive zoology as geology does from mineralogy, properly so
called. The physical history of the universe must not, therefore, be
confounded with the 'Encyclopedias of the Natural Sciences', as they have
hitherto been compiled, and whose title is as vague as their limits are ill
defined. In the work before us, partial facts will be considered only in
relation to the whole. p 56 The higher the point of view, the greater is the
necessity for a systematic mode of treating the subject in language at once
animated and picturesque.

But thought and language have ever been most intimately allied. If
language, by its originality of structure and its native richness, can, in its
delineations, interpret thought with grace and clearness, and if, by its happy
flexibility, it can paint with vivid truthfulness the objects of the external
world, it reacts at the same time upon thought, and animates it, as it were,
with the breath of life. It is this mutual reaction which makes words more

than mere signs and forms of thought; and the beneficent influence of a
language is most strikingly manifested on its native soil, where it has
sprung spontaneously from the minds of the people, whose character it
embodies. Proud of a country that seeks to concentrate her strength in
intellectual unity, the writer recalls with delight the advantages he has
enjoyed in being permitted to express his thoughts in his native language;
and truly happy is he who, in attempting to give a lucid exposition of the
great phenomena of the universe, is able to draw from the depths of a
language, which, through the free exercise of thought, and by the effusions
of creative fancy, has for centuries past exercised so powerful an influence
over the destinies of man.

This material taken from pages 56 to 78

COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1
by Alexander von Humboldt

Translated by E C Otte

from the 1858 Harper & Brothers edition of Cosmos, volume 1
—————————————————————————

p 56

LIMITS AND METHOD OF EXPOSITION OF THE PHYSICAL DESCRIPTION OF THE
UNIVERSE.

I HAVE endeavored, in the preceding part of my work, to explain and
illustrate, by various examples, how the enjoyments presented by the aspect
of nature, varying as they do in the sources from when they flow, may be
multiplied and ennobled by an acquaintance with the connection of

phenomena and the laws by which they are regulated. It remains, then, for
me to examine the spirit of the method in which the exposition of the
'physical description of the universe' should be conducted, and to indicate
the limits of this science in accordance with the views I have acquired in the
course of my studies and travels in various parts of the earth. I trust I may
flatter myself with a hope that a treatise of this nature will justify the title I
have ventured to adopt for my work, and exonerate me from the reproach of
a presumption that would be doubly reprehensible in a scientific discussion.

Before entering upon the delineation of the partial phenomena p 57
which are found to be distributed in various groups, I would consider a few
general questions intimately connected together, and bearing upon the
nature of our knowledge of the external world and its different relations, in
all epochs of history and in all phases of intellectual advancement. Under
this head will be comprised the following considerations:

1. The precise limits of the physical description of the universe,
considered as a distinct science.

2. A brief enumeration of the totality of natural phenomena, presented
under the form of a 'general delineation of nature.'

3. The influence of the external world on the imagination and feelings,
which has acted in modern times as a powerful impulse toward the study of
natural science, by giving animation to the description of distant regions
and to the delineation of natural scenery, as far as it is characterized by
vegetable physiognomy and by the cultivation of exotic plants, and their
arrangement in well-contrasted groups.

4. The history of the contemplation of nature, or the progressive
development of the idea of the Cosmos, considered with reference to the

historical and geographical facts that have led to the discovery of the
connection of phenomena.

The higher the point of view from which natural phenomena may be
considered, the more necessary it is to circumscribe the science within its
just limits, and to distinguish it from all other analogous or auxiliary
studies.

Physical cosmography is founded on the contemplation of all created
things — all that exists in space, whether as substances or forces — that is,
all the material beings that constitute the universe. The science which I
would attempt to define presents itself, therefore, to man, as the inhabitant
of the earth, under a two-fold form — as the earth itself and the regions of
space. It is with a view of showing the actual character and the
independence of the study of physical cosmography, and at the same time
indicating the nature of its relations to 'general physics, descriptive natural
history, geology, and comparative geography', that I will pause for a few
moments to consider that portion of the science of the Cosmos which
concerns the earth. As the history of philosophy does not consist of a mere
material enumeration of the philosophical views entertained in different
ages, neither should the physical description of the universe be a simple
encyclopedic compilation of the sciences we have enumerated. The
difficulty of defining the limits of intimately-connected studies has been
increased, because for centuries it has been customary to designate various
branches p 58 of empirical knowledge by terms which admit either of too
wide or too limited a definition of the ideas which they were intended to
convey, and are, besides, objectionable from having had a different
signification in those classical languages of antiquity from thish chey have
been borrowed. The terms physiology, physics, natural history, geology and
geography arose, and were commonly used, long before clear ideas were
entertained of the diversity of objects embraced by these sciences, and

consequently of their reciprocal limitation. Such is the influence of long
habit upon language, that by one of the nations of Europe most advanced in
civilization the word "physic" is applied to medicine, while in a society of
justly deserved universal reputation, technical chemistry, geology and
astronomy (purely experimental sciences) are comprised under the head of
"Philosophical Transactions."

An attempt has often been made, and almost always in vain, to substitute
new and more appropriate terms for these ancient designations, which,
notwithstanding their undoubted vagueness, are now generally understood.
These changes have been proposed, for the most part, by those who have
occupied themselves with the general classification of the various branches
of knowledge, from the first appearance of the great encyclopedia
('Margarita Philosophica') of Gregory Reisch,* prior of the Chartreuse at
Freiburg, toward the close of the fifteenth century, to Lord Bacon, and from
Bacon to D'Alembert; and in recent times to an eminent physicist, Andre
Marie Ampere.**

[footnote] *The 'Margarita Philosophica' of Gregory Reisch, prior of the
Chartreuse at Freiburg, first appeared under the following title: Aepitome
omnis Philosophiæ, alias Margarita Philosophica, tractans de omni generi
scibili. The Heidelberg edition (1486), and that of Strasburg (1504), both
bear this title, but the first part was suppressed in the Freiburg edition of the
same year, as well as in the twelve subsequent editions, which succeeded
one another, at short intervals, till 1535. This work exercised a great
influence on the diffusion of mathematical and physical sciences toward the
beginning of the sixteenth century, and Crasles, the learned author of
'L'Aperçu Historique des Methodes en Géometrica' (1837) has shown the
great importance of Reisch's 'Encyclopedia' in the history of mathematics in
the Middle Ages. I have had recourse to a passage in the 'Margarita

Philosophica', found only in the edition of 1513, to elucidate the important
question of the relations between the statements of the geographer of Saint-
Die, Hylacomilus (Martin Waldseemuller), the first who gave the name of
America to the New Continent, and those of Amerigo Vespucci, Rene, King
of Jerusalem and Duke of Lorraine, as also those contained in the celebrated
editions of Ptolemy of 1513 and 1522. See my 'Examen Critique de la
Gegraphie du Nouveau Continent, et des Progres de l'Astronomie Nautique
aux 15e et 16e Siecles', t. iv., p. 99-125.

[footnote] II Ampère, 'Essai sur la Phil. des Sciences', 1834, p. 25.
Whewell, 'Philosophy of the Inductive Sciences', vol. ii., p. 277. Park,
'Pantology', p. 87.

p 59 The selection of an inappropriate Greek nomenclature has perhaps
been even more prejudicial to the last of these attempts than the injudicious
use of binary divisions and the excessive multiplication of groups.

The physical description of the world, considering the universe as an
object of the external senses, does undoubtedly require the aid of general
physics and of descriptive natural history, but thecontemplation of all
created things, which are linked together, and form one 'whole', animated by
internal forces, given to the science we are considering a peculiar character.
Phyical science considers only the general properties of bodies; it is the
product of abstraction — a generalization of perceptible phenomena; and
even in the work in which were laid the first foundations of general physics,
in the eight books on physics of Aristotle,* all the phenomena of nature are
considered as depending upon the primitive and vital action of one sole
force, from which emaate all the movements of the universe.

[footnote] * All changes in the physical world may be reduced to motion.
Aristot., 'Phys. Ausc.', iii., 1 and 4, p. 200, 201. Bekker, viii., 1, 8, and 9, p.
250, 262, 265. 'De Genere et Corr.', ii., 10, p. 336. Pseudo-Aristot., 'De
Mundo.' cap. vi., p. 398.

The terrestrial portion of physical cosmography, for which I would
willingly retain the expressive designation of 'physical geography', treats of
the distribution of magnetism in our planet with relation to its intensity and
direction, but does not enter into a consideration of the laws of attraction or
repulsion of the poles, or the means of eliciting either permanent or
transitory electro-magnetic currents. Physical geography depicts in broad
outlines the even or irregular configuration of continents, the relations of
superficial area, and the distribution of continental masses in the two
hemispheres, a distribution which exercises a powerful influence on the
diversity of climate and the meteorological modifications of the
atmosphere; this science defines the character of mountain chains, which,
having been elevated at different epochs, constitute distinct systems,
whether they run in parallel lines or intersect one another; determines the
mean height of continents above the level of the sea, the position of the
center of gravity of their volume, and the relation of the highest summits of
mountain chains to the mean elevation of their crests, or to their proximity
with the sea-shore. It depicts the eruptive rocks as principles of movement,
acting upon the sedimentary rocks by traversing, uplifting, and inclining
them at various angles; it p 60 considers volcanoes either as isolated, or
ranged in single or in double series, and extending their sphere of action to
various distances, either by raising long and narrow lines of rocks, or by
means of circles of commotion, which expand or diminish in diameter in
the course of ages. This terrestrial portion of the science of the Cosmos
describes the strife of the liquid element with the solid land; it indicates the
features possessed in common by all great rivers in the upper and lower

portion of their course, and in their mode of bifurcation when their basins
are unclosed; and shows us rivers breaking through the highest mountain
chains, or following for a long time a course parallel to them, either at their
base, or at a considerable distance, where the elevation of the strata of the
mountain system and the direction of their inclination correspond to the
configuration of the table-land. It is only the general results of comparative
orography and hydrography that belong to the science whose true limits I
am desirous of determining, and not the special enumeration of the greatest
elevations of our globe, of active volcanoes, of rivers, and the number of
their tributaries, these details falliing rather within the domain of
geography, properly so called. We would here only consider phenomena in
their mutual connection, and in their relations to different zones of our
planet, and to its physical constitution generally. The specialties both of
inorganic and organized matter, classed according to analogy of form and
composition, undoubtedly constitute a most interesting branch of study, but
they appertain to a sphere of ideas having no affinity with the subject of this
work.

The description of different countries certainly furnishes us with the most
important materials for the composition of a physical geography; but the
combination of these different descriptions, ranged in series, would as little
give us a true image of the general conformation of the irregular surface of
our globe, as a succession of all the floras of different regions would
constitute that which I designate as a 'Geography of Plants.' It is by
subjecting isolated observations to the process of thought, and by
combining and comparing them, that we are enabled to discover the
relations existing in common between the climatic distribution of beings
and the individuality of organic forms (in the morphology or descriptive
natural history of plants and animals); and it is by induction that we are led
to comprehend numerical laws, the proportion of natural families to the
whole number of species, and to designate the latitude or geographical

position of the zones in whose p 61 plains each organic form attains the
maximum of its development. Considerations of this nature, by their
tendency to generalization, impress a nobler character on the physical
description of the globe, and enable us to understand how the aspect of the
scenery, that is to say, the impression produced upon the mind by the
physiognomy of the vegetation, depends upon the local distribution, the
number, and the luxuriance of growth of the vegetable forms predominating
in the general mass. The catalogues of organized beings to which was
formerly given the pompous title of 'Systems of Nature', present us with an
admirably connected arrangement by analogies of structure, either in the
perfected development of these beings, or in the different phases which, in
accordance with the views of a spiral evolution, affect in vegetables the
leaves, bracts, calyx, corolla and fructifying organs; and in animals, with
more or less symmetrical regularity, the cellular and fibrous tissues, and
their perfect or but obscurely developed articulations. But these pretended
systems of nature, however ingenious their mode of classification may be,
do not show us organic beings as they are distributed in groups throughout
our planet, according to their different relations of latitude and elevation
above the level of the sea, and to climatic influences, which are owing to
general and often very remote causes. The ultimate aim of physical
geography is, however, as we have already said, to recognise unity in the
vast diversity of phenomena, and by the exercise of thought and the
combination of observations, to discern the constancy of phenomena in the
midst of apparent changes. In the exposition of the terrestrial portion of the
Cosmos, it will occasionally be necessary to descend to very special facts;
but this will only be in order to recall the connection existing between the
actual distribution of organic beings over the globe, and the laws of the
ideal classification by natural families, analogy of internal organization and
progressive evolution.

It follows from these discussions on the limits of the various sciences,
and more particularly from the distinction which must necessarily be made
between descriptive botany (morphology of vegetables) and the geography
of plants, that in the physical history of the globe, the innumerable
multitude of organized bodies which embellish creation are considered
rather according to 'zones of habitation' or 'stations', and to differently
inflected 'isothermal bands', than with reference to the principles of
gradation in the development of internal organism. Notwithstanding this,
botany and zoology, which constitute p 62 the descriptive natural history of
all organized beings, are the fruitful sources whence we draw the materials
necessary to give a solid basis to the study of the mutual relations and
connection of phenomena.

We will here subjoin one important observation by way of elucidating the
connection of which we have spoken. The first general glance over the
vegetation of a vast extent of a continent shows us forms the most
dissimilar — Graminae and Orchideae, Coniferae and oaks, in local
approximation to one another; while natural families and genera, instead of
being locally associated, are dispersed as if by chance. This dispersion is,
however, only apparent. The physical description of the globe teaches us
that vegetation every where presents numerically constant relations in the
development of its forms and types; that in the same climates, the species
which are wanting in one country are replaced in a neighboring one by
other species of the same family; and that this 'law of substitution', which
seems to depend upon some inherent mysteries of the organism, considered
with reference to its origin, maintains in contiguous regions a numerical
relation between the species of various great families and the general mass
of the phanerogamic plants constituting the two floras. We thus revealed in
the multiplicity of the distinct organizations by which these regions are
occupied; and we also discover in each zone, and diversified according to
the families of plants, a slow but continuous action on the aerial ocean,

depending upon the influence of light — the primary condition of all
organic vitality — on the solid and liquid surface of our planet. It might be
said, in accordance with a beautiful expression of Lavoisier, that the ancient
marvel of the myth of Prometheus was incessantly renewed before our eyes.

If we extend the course which we have proposed, following in the
exposition of the physical description of the earth to the sidereal part of the
science of the Cosmos, the delineation of the regions of space and the
bodies by which they are occupied, we shall find our task simplified in no
common degree. If, according to ancient but unphilosophical forms of
nomenclature, we would distinguish between 'physics', that is to say,
general considerations on the essence of matter, and the forces by which it
is actuated, and 'chemistry', which treats of the nature of substances, their
elementary composition, and those attractions that are not determined solely
by the relations of mass, we must admit that the description of the earth
comprises at p 63 once 'physical' and 'chemical' actions. In addition to
gravitation, which must be considered as a primitive force in nature, we
observe that attractions of another kind are at work around us, both in the
interior of our planet and on its surface. These forces, to which we apply the
term 'chemical affinity', act upon molecules in contact, or at infinitely
minute distances from one another,* and which, being differently modified
by electricity, heat, condensation in porous bodies, or by the contact of an
intermediate substance, animate equally the inorganic world and animal and
vegetable tissues.

[footnote] * On the question already discussed by Newton, regarding the
difference existing between the attraction of masses and molecular
attraction, see Laplace, 'Exposition du Systeme du Monde', p. 384, and
supplement to book x. of the 'Mecanique Celeste', p. 3, 4; Kant, 'Metaph.
Anfangegrunde der Naturwissenschaft, Säm. Werke', 1839, bd. v., s. 309

(Metaphysical Principles of the Natural Sciences); Pectet, 'Physique', 1838,
vol. i., p. 59-63.

If we except the small asteroids, which appear to us under the forms of
aerolites and shooting stars, the regions of space have hitherto presented to
our direct observation physical phenomena alone; and in the case of these,
we know only with certainty the effects depending upon the quantitative
relations of matter of the distribution of masses. The phenomena of the
regions of space may consequently be considered as influenced by simple
dynamical laws — the laws of motion.

The effects that may arise from the specific difference and the
hererogeneous nature of matter have not hitherto entered into our
calculations of the mechanism of the heavens. The only means by which the
inhabitants of our planet can enter into relation with the matter contained
within the regions of space, whether existing in scattered forms or united
into large spheroids, is by the phenomena of light, the propagation of the
force of gravitation or the attraction of masses. The existence of a periodical
action of the sun and moon on the variations of terrestrial magnetism is
even at the present day extremely problematical. We have no direct
experimental knowledge regarding the properties and specific qualities of
the masses circulating in space, or of the matter of which they are probably
composed, if we except what may be derived from the fall of aerolites or
meteoric stones, which, as we have already observed, enter within the limits
of our terrestrial sphere. It will be sufficient here to remark, that the
direction and the excessive velocity of projection (a velocity wholly
planetary) manifested by these masses, render it more than probable that p
64 they are small celestial bodies, which, being attracted by our planet, are
made to deviate from their original course, and thus reach the earth
enveloped in vapors, and in a high state of actual incandescence. The

familiar aspect of these asteroids, and the analogies which they present with
the minerals composing the earth's crust, undoubtedly afford ample grounds
for surprise,* but, in my opinion, the only conclusion to be drawn from
these facts is that, in general, planets and other sidereal masses, which by
the influence of a central body, have been agglomerated into rings of vapor,
and subsequently into spheroids, being integrant parts of the same system,
and having one common origin, may likewise be composed of substances
chemically identical.

[footnote] I[The analysis of an aerolite which fell a few years since in
Maryland, United States, and was examined by Professor Silliman, of New
Haven, Connecticut, gave the following results: Oxyd of iron, 24; oxyd of
nickel, 1.25; silica, with earthy matter, 3.46; sulphur, a trace - 28.71. Dr.
Mantell's 'Wonders of Geology', 1848, vol. i., p. 51.] — 'Tr.'

Again, experiments with the pendulum, particularly those prosecuted
with such rare precision by Bessel, confirm the Newtonian axiom, that
bodies the most heterogeneous in their nature (as water, gold, quartz,
granular limestone, and different masses of aerolites) experience a perfectly
similar degree of acceleration from the attraction of the earth. To the
experiments of the pendulum may be added the proofs furnished by purely
astronomical observations. The almost perfect identity of the mass of
Jupiter, deduced from the influence exercised by this stupendous planet on
its own satellites, on Enck's comet of short period, and on the small planets
Vesta, Juno, Ceres, and Pallas, indicates with equal certainty that within the
limits of actual observation attraction is determined solely by the quantity
of matter.*

[footnote] *Poisson, 'Connaissances des Temps pour l'Anne' 1836, p. 64-
66. Bessel, Poggendorf's 'Annalen', bd. xxv., s. 417. Encke, 'Abhandlungen
der Berliner Academie' (Trans. of the Berlin Academy), 1826, s. 257.
Mitscherlich, 'Lehrbuch der Chemie' (Manual of Chemistry), 1837 bd. i. s.
352.

This absence of any perceptible difference in the nature of matter, alike
proved by direct observation and theoretical deductions, imparts a high
degree of simplicity to the mechanism of the heavens. The immeasurable
extent of the regions of space being subjected to laws of motion alone, the
sidereal portion of the science of the Cosmos is based on the pure and
abundant source of mathematical astronomy, as is the terrestrial portion on
physics, chemistry, and organic morphology; but the domain of these three
last-named sciences embraces p 65 the consideration of phenomena which
are so complicated and have, up to the present time, been found so little
susceptible of the application of rigorous method, that the physical science
of the earth can not boast of the same certainty and simplicity in the
exposition of facts and their mutual connection which characterize the
celestial portion of the Cosmos. It is not improbable that the difference to
which we allude may furnish an explanation of the cause which, in the
earliest ages of intellectual culture among the Greeks, directed the natural
philosophy of the Pythagoreans with more ardor to the heavenly bodies and
the regions of space than to the earth and its productions, and how through
Philolaus, and subsequently through the analogous views of Aristarchus of
Samos, and of Seleucus of Erythrea, this science has been made more
conducive to the attainment of a knowledge of the true system of the world
than the natural philosophy of the Ionian school could ever be to the
physical history of the earth. Giving but little attention to the properties and
specific differences of matter filling space, the great Italian school, in its
Doric gravity, turned by preference toward all that relates to measure, to the

form of bodies, and to the number and distances of the planets,* while the
Ionian physicists directed their attention to the qualities of matter, its true or
supposed metamorphoses, and to relations of origin.

[footnote] *Compare Otfried Muller's 'Dorien', bd. i., s. 365.

It was reserved for the powerful genius of Aristotle, alike profoundly
speculative and practical to sound with equal success the depths of
abstraction and the inexhaustible resources of vital activity pervading the
material world.

Several highly distinguished treatises on physical geography are prefaced
by an introduction, whose purely astronomical sections are directed to the
consideration of the earth in its planetary dependence, and as constituting a
part of that great system which is animated by one central body, the sun.
This course is diametrically opposed to the one which I propose following.
In order adequately to estimate the dignity of the Cosmos, it is requisite that
the sidereal portion, termed by Kant the 'natural history of the heavens',
should not be made subordinate to the terrestrial. In the science of the
Cosmos, according to the expression of Aristarchus of Samos, the pioneer
of the Copernican system, the sun, with its satellites, was nothing more than
one of the innumerable stars by which space is occupied. The physical
history of the world must, therefore, begin with the description of the
heavenly bodies, p 66 and with a geographical sketch of the universe, or, I
would rather say, a true 'map of th world', such as was traced by the bold
hand of the elder Herschel. If, notwithstanding the smallness of our planet,
the most considerable space and the most attentive consideration be here
afforded to that which exclusively concerns it, this arises solely from the
disproportion in the extent of our knowledge of that which is accessible and
of that which is closed to our observation. This subordination of the

celestial to the terrestrial portion is met with in the great work of Bernard
Varenius,* which appeared in the middle of the seventeenth century.

[Footnote] *'Geographia Generalis in qua affectiones generales telluris
explicantur.' The oldest Elzevir edition bears date 1650, the second 1672,
and the third 1681; these were published at Cambridge, under Newton's
supervision. This excellent work by Varenius is, in the true sense of the
words, a physical description of the earth. Since the work 'Historia Natural
de las Indias', 1590, in which the Jesuit Joseph de Acosta sketched in so
masterly a manner the delineation of the New Continent, questions relating
to the physical history of the earth have never been considered with such
admirable generality. Acosta is richer in original observations, while
Varenius embraces a wider circle of ideas, since his sojourn in Holland,
which was at that period the center of vast commercial relations, had
brought him in contact with a great number of well-iinformed travelers.
'Generalis sive Universalis Geographia dictur quae tellurem in genere
considerat atque affectiones explicat, non habita particularium regionum
ratione.' The general description of the earth by Varenius ('Pars Absoluta',
cap. i.-xxii.) may be considered as a treatise of comparative geography, if
we adopt the term used by the author himself ('Geographia Comparativa',
cap. xxxiii.-xl.), although this must be understood in a limited acceptation.
We may cite the following among the most remarkable passages of this
book: the enumeration of the systems of mountains; the examination of the
relations existing between their directions and the general form of
continents (p. 66, 76, ed. Cantab., 1681); a list of extinct volcanoes, and
such as were still in a state of activity; the discussion of facts relative to the
general distribution of islands and archipelagoes (p. 220); the depth of the
ocean relatively to the height of neighboring coasts (p. 103); the uniformity
of level observed in all open seas (p. 97); the dependence of currents on the
prevailing winds; the unequal saltness of the sea; the configuration of

shores (p. 139); the direction of the winds as the result of differences of
temperature, etc. We may further instance the remarkable considerations of
Varenius regarding the equinoctial current from east to west, to which he
attributes the origin of the Gulf Stream, beginning at Cape St. Augustin, and
issuing forth between Cuba and Florida (p. 140). Nothing can be more
accurate than his description of the current which skirts the western coast of
Africa, between Cape Verde and the island of Fernando Po in the Gulf of
Guinea. Varenius explains the formation of sporadic islands by supposing
them to be "the raised bottom of the sea:" 'magna spirituum inclusorum vi,
sicut aliquando montes e terra protusos esse quidam scribunt' (p. 225). The
edition published by Newton in 1681 ('auctior et emendatior' unfortunately
contains no additions from this great authority; and there is not even
mention made of the polar compression of the globe, although the
experiments on the pendulum by Richer had been made nine years prior to
the appearance of the Cambridge edition. Newton's 'Principia Mathematica
Philosophie Naturalis' were not communicated in manuscript to the Royal
Society until April, 1686. Much uncertainty seems to prevail regarding the
birth-place of Varenius. Jaecher says it was England, while, according to 'La
Biographie Universelle' (b.xlvii., p. 495), he is stated to have been born at
Amsterdam; but it would appear, from the dedicatory address to the
burgomaster of that city (see his 'Geographia Comparativa', that both
suppositions are false. Varenius expressly says that he had sought refuge in
Amsterdam, "because his native city had been burned and completely
destroyed during a long war," words which appear to apply to the north of
Germany, and to the devastations of the Thirty Years' War. In his dedication
of another work, 'Descriptio regni Japoniae' (Amst., 1649), to the Senate of
Hamburgh, Varenius says that he prosecuted his elementary mathematical
studies in the gymnasium of that city. There is, therefore, every reason to
believe that this admirable geographer was a native of Germany, and was

probably born at Luneburg ('Witten. Mem. Theol.', 1685, p. 2142; Zedler,
'Universal Lexicon', vol. xlvi., 1745, p. 187).

p 67 He was the first to distinguish between 'general and special
geography', the former of which he subdivides into an 'absolute', or,
properly speaking, 'terrestrial' part, and a 'relative or planetary' portion,
according to the mode of considering our planet either with reference to its
surface in its different zones, or to its relations to the sun and moon. It
redounds to the glory of Varenius that his work on 'General and
Comparative Geography' should in so high a degree have arrested the
attention of Newton. The imperfect state of many of the auxiliary sciences
from which this writer was obliged to draw his materials prevented his
work from corresponding to the greatness of the design, and it was reserved
for the present age, and for my own country, to see the delineation of
comparative geography, drawn in its full extent, and in all its relations with
the history of man, by the skillful hand of Carl Ritter.*

[Footnote] *Carl Ritter's 'Erdkunde im Verhältniss zur Natur und zur
Geschichte des Menschen, oder allgemeine vergleichende Geographie'
(Geography in relation to Nature and the History of Man, or general
Comparative Geography).

The enumeration of the most important results of the astronomical and
physical sciences which in the history of the Cosmos radiate toward one
common focus, may perhaps, to a certain degree, justify the designation I
have given to my work, and, considered within the circumscribed limits I
have proposed to myself, the undertaking may be esteemed less
adventurous than the title. The introduction of new terms, especially with
reference to the general results of a science which p 68 ought to be
accessible to all, has always been greatly in opposition to my own practice;

and whenever I have enlarged upon the established nomenclature, it has
only been in the specialities of descriptive botany and zoology, where the
introduction of hitherto unknown objects rendered new names necessary.
The denominations of physical descriptions of the universe, or physical
cosmography, which I use indiscriminantely, have been modeled upon those
of 'physical descriptions of the earth', that is to say, 'physical geography',
terms that have long been in common use. Descartes, whose genius was one
of the most powerful manifested in any age, has left us a few fragments of a
great work, which he intended publishing under the title of 'Monde', and for
which he had prepared hiimself by special studies, including even that of
human anatomy. The uncommon, but definite expression of the 'science of
the Cosmos' recalls to the mind of the inhabitant of the earth that we are
treating of a more widely-extended horizon — of the assemblage of all
things with which space is filled, from the remotest nebulae to the climatic
distribution of those delicate tissues of vegetable matter which spread a
variegated covering over the surface of our rocks.

The influence of narrow-minded views peculiar to the earlier ages of
civilization led in all languages to a confusion of ideas in the synonymic use
of the words 'earth' and 'world', while the common expressions 'voyages
round the world', 'map of the world', and 'new world', afford further
illustrations of the same confusion. The more noble and precisely-defined
expressions of 'system of the world', 'the planetary world', and 'creation and
age of the world', relate either to the totality of the substances by which
space is filled, or to the origin of the whole universe.

It was natural that, in the midst of the extreme variability of phenomena
presented by the surface of our globe, and the aerial ocean by which it is
surrounded, man should have been impressed by the aspect of the vault of
heaven, and the uniform and regular movements of the sun and planets.
Thus the word Cosmos, which primitively, in the Homeric ages, indicated

an idea of order and harmony, was subsequently adopted in scientific
language, where it was gradually applied to the order observed in the
movements of the heavenly bodies, to the whole universe, and then finally
to the world in which this harmony was reflected to us. According to the
assertion of Philolaus, whose fragmentary works have been so ably
commented upon by Böckh, and conformably to the general testimony p 69
of antiquity, Pythagoras was the first who used the word Cosmos to
designate the order that reigns in the universe, or entire world.*

[footnote] *[Greek word], in the most ancient, and at the same time most
precise, definition of the word, signified 'ornament' (as an adornment for a
man, a woman, or a horse); taken figuratively for [Greek word], it implied
the order or adornment of a discourse. According to the testimony of all the
ancients, it was Pythagoras who first used the word to designate the order in
the universe, and the universe itself. Pythagoras left no writings; but ancient
attestation to the truth of this assertion is to be found in several passages of
the fragmentary works of Philolaus (Stob., 'Eclog.', p. 360 and 460,
Heeren), p. 62, 90, in Bockh's German edition. I do not, according to the
example of Nake, cite Timof Locris, since his authenticity is doubtful.
Plutarch ('De plac. Phil.', ii., I) says, in the most express manner, that
Pythatoras gave the name of Cosmos to the universe on account of the order
which reigned throughout it; so likewise does Galen ('Hist. Phil.', p. 429).
This word, together with its novel signification, passed from the schools of
philosophy into the language of poets and prose writers. Plato designates
the heavenly bodies by the name of 'Uranos', but the order pervading the
regions of space he too terms the Cosmos, and in his 'Timus' (p. 30 a.) he
says 'that the world is an animal endowed with a soul' [Greek words].
Compare Anaxag. Claz., ed. Schaubach, p. III, and Plut. ('De plac. Phil.', in
Aristotle ('De Caelo', I, 9), 'Cosmos' signifies "the universe and the order
pervading it," but it is likewise considered as divided in space into two parts

— the sublunary world, and the world above the moon. ('Meteor.', I., w, 1,
and I., 3, 13, p. 339, 'a', and 340, 'b', Bekk.) The definition of Cosmos,
which I have already cited is taken from Pseudo-Aristoteles 'de Mundo',
cap. ii. (p. 391); the passage referred to is as follows: [Greek words]. Most
of the passages occurring in Greek writers on the word 'Cosmos' may be
found collected together in the controversy between Richard Bentley and
Charles Boyle ('Opuscula Philologica', 1781, p. 347, 445; 'Dissertation upon
the Epistles of Phalaris', 1817, p. 254); on the historical existence of
Zaleucus, legislator of Leucris, in Nake's excellent work, 'Sched. Crit.',
1812, p. 9, 15; and, finally in Theophilus Schmidt, 'ad Cleom. Cycl. Theor.',
met. I., 1, p. ix., 1 and 99. Taken in a more limited sense, the word Cosmos
is also used in the plural (Plut., 1, 5), either to designate the stars (Stob., 1,
p. 514; Plut., 11, 13) or the innumerable systems scattered like islands
through the immensity of space, and each composed of a sun and a moon.
(Anax. Claz., 'Fragm.', p. 89, 93, 120; Brandis, 'Gesch. der Griechisch-
Römischen Philosophie', b. i., s. 252 (History of the Greco-Roman
Philosophy). Each of these groups forming thus a 'Cosmos', the universe,
[Greek words], the word must be understood in a wider sense (Plut., ii., 1).
It was not until long after the time of the Ptolemies that the word was
applied to the earth. Bockh has made known inscriptions in praise of Trajan
and Adrian ('Corpus Inscr. Graec.', I, n. 334 and 1036), in which [Greek
word] occurs for [Greek word] in the same manner as we still use the term
'world' to signify the earth alone. We have already mentioned the singular
division of the regions of space p 70 [Footnote continues] into three parts,
the 'Olympus, Cosmos' and 'Ouranos' (Stob., i., p. 488; Philolaus, p. 95,
303); this division applies to the different regions surrounding that
mysterious focus of the universe, the [Greek words] of the Pythagoreans. In
the fragmentary passage in which this division is found, the term [Greek
word] designates the innermost region, situated between the moon and
earth; this is the domain of changing things. The middle region, where the

planets circulate in an invariable and harmonious order, is, in accordance
with the special conceptions entertained of the universe, exclusively termed
'Cosmos', while the word 'Olympus' is used to express the exterior or
igneous region. Bopp, the profound philologist, has remarked that we may
deduce, as Pott has done, 'Etymol. Forschungen', th.i., s. 39 and 252
('Etymol. Researches'), the word [Greek word] from the Sanscrit root 'sud',
'purificari', by assuming two conditions; first that the Greek letter 'kappa' in
[Greek word] comes from the palatial 'epsilon', which Bopp represents by 's'
and Pott by 'ç' (in the same manner as [Greek word], 'decem, taihun' in
Gothic, comes from the Indian word 'dasan'), and, next, that the Indian 'd''
corresponds, as a general rule, with the Greek 'theta' ('Vergleichende
Grammatik' 99 — Comparative Grammar), which shows the relation of
[Greek word] (for [Greek word]) with the Sanscrit root 'sud', whence is also
derived [Greek word]. Another Indian term for the world is 'gagat'
(pronounced 'dschagat'), which is, properly speaking the present participle
of the verb 'gagami' (I go), the root of which is 'ga.' In restricting ourselves
to the circle of Hellenic etymologies, we find ('Etymol. M.', p. 532, 12) that
[Greek word] is intimately associated with [Greek word] or rather with
[Greek word], whence we have [Greek word] or [Greek word] Welcker
('Eine Kretische Col in Theben', s. 23 — A Cretan Colony in Thebes)
combines with this the name [Greek word] , as in Hesychius [Greek word]
signifies a Cretan suit of arms. When the scientific language of Greece was
introduced among the Romans, the word 'mundus', which at first had only
the primary meaning of [Greek word] (female ornament), was applied to
designate the entire universe. Ennius seems to have been the first who
ventured upon this innovation. In one of the fragments of this poet,
preserved by Macrobius, on the occasion of his quarrel with Virgil, we find
the word used in its novel mode of acceptation: "Mundus caeli vastus
constitit silentio" (Sat., vi., 2). Cicero also says, "Quem nos lucentem
mundum vocamus" (Timæus, 'S.de univer.', cap. x.) The Sanscrit root

'mand' from which Pott derives the Latin 'mundus' ('Etym. Forsch.', th. i., s.
240), combines the double signification of shining and adorning. 'Loka'
designates in Sanscrit the world and people in general, in the same manner
as the French word 'monde', and is derived according to Bopp, from 'lok' (to
see and shine); it is the same with the Slavonic root 'swjet', which means
both 'light' and 'world.' (Grimm, 'Deutsche Gramm.', b. iii., s. 394 —
German Grammar.) The word 'welt', which the Germans make use of at the
present day, and which was 'weralt' in old German, 'worold' in old Saxon,
and 'weruld' in Anglo-Saxon, was, according to James Grimm's
interpretation, a period of time, an age ('saeculum') rather than a term used
for the world in space. The Etruscans figured to themselves 'mundus' as an
inverted dome, symmetrically opposed to the celestial vault (Otfried
Muller's 'Etrusken', th. ii., s. 96, etc.). Taken in a still more limited sense,
the word appears to have signified among the Goths the terrestrial surface
girded by seas ('marei, meri',) the 'merigard', literally, 'garden of seas.'

From the Italian school of philosophy, the expression passed, in this
signification, into the language of those early poets p 71 of nature,
Parmenides and Empedocles, and from thence into the works of prose
writers. We will not here enter into a discussion of the manner in which,
according to the Pythagorean views, Philolaus distinguishes between
Olympus, Uranus, or the heavens, and Cosmos, or how the same word, used
in a plural sense, could be applied to certain heavenly bodies (the planets)
revolving round one central focus of the world, or to groups of stars. In this
work I use the word Cosmos in conformity with the Hellenic usage of the
term subsequently to the time of Pythagorus, and in accordance with the
precise definition given of it in the treatise entitled 'De Mundo', which was
long erroneously attributed to Aristotle. It is the assemblage of all things in
heaven and earth, the universality of created things constituting the
perceptible world. If scientific terms had not long been diverted from their

true verbal signification, the present work ought rather to have borne the
title of 'Cosmography', divided into 'Uranography' and 'Geography.' The
Romans, in their feeble essays on philosophy, imitated the Greeks by
applying to the universe the term 'mundus', which, in its primary meaning,
indicated nothing more than ornament, and did not even imply order or
regularity in the disposition of parts. It is probable that the introduction into
the language of Latium of this technical term as an equivalent for Cosmos,
in its double signification, is due to Ennius,* who was a follower of the
Italian school, and the translator of the writings of Epicharmus and some of
his pupils on the Pythagorean philosophy.

[footnote] *See, on Ennius, the ingenious researches of Leopold Krahner,
in his 'Grundlinien zur Geschichte des Verfalls der Romischen Staats-
Reigion', 1837, s. 41-45 (Outlines of the History of the Decay of the
Established Religion among the Romans). In all probability, Ennius did not
quote from writings of Epicharmus himself, but from poems composed in
the name of that philosopher, and in accordance with his views.

We would first distinguish between the physical 'history' and the physical
'description' of the world. The former, conceived in the most general sense
of the word, ought, if materials for writing it existed, to trace the variations
experienced by the universe in the course of ages from the new stars which
have suddenly appeared and disappeared in the vault of heaven, from
nebulæ dissolving or condensing — to the first stratum of cryptogamic
vegetation on the still imperfectly cooled surface of the earth, or on a reef of
coral uplifted from the depths of ocean. 'The physical description of the
world' presents a picture of all that exists in space — of the siimultaneous
action of p 72 natural forces, together with the phenomena which they
produce.

But if we would correctly comprehend nature, we must not entirely or
absolutely separate the consideration of the present state of things from that
of the successive phases through which they have passed. We can not form
a just conception of their nature without looking back on the mode of their
formation. It is not organic matter alone that is continually undergoing
change, and being dissolved to form new combinations. The globe itself
reveals at every phase of its existence the mystery of its former conditions.

We can not survey the crust of our planet without recognizing the traces
of the prior existence and destruction of an organic world. The sedimentary
rocks present a succession of organic forms, associated in groups, which
have successively displaced and succeeded each other. The different super-
imposed strata thus display to us the faunas and floras of different epochs.
In this sense the description of nature is intimately connected with its
history; and the geologist, who is guided by the connection existing among
the facts observed, can not form a conception of the present without
pursuing, through countless ages, the history of the past. In tracing the
physical delineation of the globe, we behold the present and the past
reciprocally incorporated, as it were, with one another; for the domain of
nature is like that of languages, in which etymological research reveals a
successive development, by showing us the primary condition of an idiom
reflected in the forms of speech in use at the present day. The study of the
material world renders this reflection of the past peculiarly manifest, by
displaying in the process of formation rocks of eruption and sedimentary
strata similar to those of former ages. If I may be allowed to borrow a
striking illustration from the geological relations by which the physiognomy
of a country is determined, I would say that domes of trachyte, cones of
basalt, lava streams ('coules')of amygdaloid with elongated and parallel
pores, and white deposits of pumice, intermixed with black scoriae, animate
the scenery by the associations of the past which they awaken, acting upon

the imagination of the enlightened observer like traditional records of an
earlier world. Their form is their history.

The sense in which the Greeks and Romans originally employed the
word 'history' proves that they too were intimately convinced that, to form a
complete idea of the present state of the universe, it was necessary to
consider it in its successive p 73 phases. It is not, however, in the definition
given by Valerius Flaccus,* but in the zoological writings of Aristotle, that
the word 'history' presents itself as an exposition of the results of experience
and observation.

[Footnote] *Aul. Gell., 'Nect. Att.', v., 18.

The physical description of the word by Pliny the elder bears the title of
'Natural History', while in the letters of his nephew it is designated by the
nobler term of 'History of Nature.' The earlier Greek historians did not
separate the description of countries from the narrative of events of which
they had been the theater. With these writers, physical geography and
history were long intimately associated, and remained simply but elegantly
blended until the period of the development of political interests, when the
agitation in which the lives of men were passed caused the geographical
portion to be banished from the history of nations, and raised into an
independent science.

It remains to be considered whether by the operation of thought, we may
hope to reduce the immense diversity of phenomena comprised by the
Cosmos to the unity of a principle, and the evidence afforded by rational
truths. In the present state of empirical knowledge, we can scarcely flatter
ourselves with such a hope. Experimental sciences, based on the
observation of the external world, can not aspire to completeness; the nature

of things, and the imperfection of our organs, are alike opposed to it. We
shall never succeed in exhausting the immeasurable riches of nature; and no
generation of men will ever have cause to boast of having comprehended
the total aggregation of phenomena. It is only by distributing them into
groups that we have been able, in the case of a few, to discover the empire
of certain natural laws, grand and simple as nature itself. The extent of this
empire will no doubt increase in proportion as physical sciences are more
perfectly developed. Striking proofs of this advancement have been made
manifest in our own day, in the phenomena of electro-magnetism, the
propagation of luminous waves and radiating heat. In the same manner, the
fruitful doctrine of evolution shows us how, in organic development, all that
is formed is sketched out beforehand, and how the tissues of vegetable and
animal matter uniformly arise from the multiplication and transformation of
cells.

The generalization of laws, which, being at first bounded by narrow
limits, had been applied solely to isolated groups of phenomena, acquires in
time more marked gradations, and gains in extent and certainty as long as
the process of reasoning p 74 is applied strictly to analogous phenomena;
but as soon as dynamical views prove insufficient where the specific
properties and heterogeneous nature of matter come into play; it is to be
feared that, by persisting in the pursuit of laws, we may find our course
suddenly arrested by an impassible chasm. The principle of unity is lost
sight of, and the guiding clew is rent asunder whenever any specific and
peculiar kind of action manifests itself amid the active forces of nature. The
law of equivalents and the numerical proportions of composition, so happily
recognized by modern chemists, and proclaimed under the ancient form of
atomic symbols, still remains isolated and independent of mathematicl laws
of motion and gravitation.

Those productions of nature which are objects of direct observation may
be logically distributed in classes, orders, and families. This form of
distribution undoubtedly sheds some light on descriptive natural history, but
the study of organized bodies, considered in their linear connection,
although it may impart a greater degree of unity and simplicity to the
distribution of groups, can not rise to the height of a classification based on
one sole principle of composition and internal organization. As different
gradations are presented by the laws of nature according to the extent of the
horizon, or the limits of the phenomena to be considered, so there are
likewise differently graduated phases in the investigation of the external
world. Empiricism originates in isolated views, which are subsequently
grouped according to their analogy or dissimilarity. To direct observation
succeeds, although long afterward, the wish to prosecute experiments; that
is to say, to evoke phenomena under different determined conditions. The
rational experimentalist does not proceed at hazard, but acts under the
guidance of hypotheses, founded on a half indistinct and more or less just
intuition of the connection existing among natural objects or forces. That
which has been conquered by observation or by means of experiments,
leads, by analysis and induction, to the discovery of empirical laws. These
are the phases in human intellect that have marked the different epochs in
the life of nations, and by means of which that great mass of facts has been
accumulated which constitutes at the present day the solid basis of the
natural sciences.

Two forms of abstraction conjointly regulate our knowledge, namely,
relations of 'quantity', comprising ideas of number and size, and relations of
'quality', embracing the consideration of the specific properties and the
heterogeneous nature p 75 of matter. The former, as being more accessible
to the exercise of thought, appertains to mathematics; the latter, from the
apparent mysteries and greater difficulties, falls under the domain of the
chemical sciences. In order to submit phenomena to calculation, recourse is

had to a hypothetical construction of matter by a combination of molecules
and atoms, whose number, form, position, and polarity determine, modify,
or vary phenomena.

The mythical ideas long entertained of the imponderable substances and
vital forces peculiar to each mode of organization, have complicated our
views generally, and shed an uncertain light on the path we ought to pursue.

The most various forms of intuition have thus, age after age, aided in
augmenting the prodigious mass of empirical knowledge, which, in our own
day has been enlarged with ever-increasing rapidity. The investigating spirit
of man strives from time to time, with varying success, to break through
those ancient forms and symbols invented, to subject rebellious matter to
rules of mechanical construction.

We are still very far from the time when it will be possible for us to
reduce, by the operation of thought, all that we perceive by the senses, to
the unity of a rational principle. It may even be doubted if such a victory
could ever be achieved in the field of natural philosophy. The complication
of phenomena, and of the vast extent of the Cosmos, would seem to oppose
such a result; but even a partial solution of the problem — the tendency
toward a comprehension of the phenomena of the universe — will not the
less remain the eternal and sublime aim of every investigation of nature.

In conformity with the character of my former writings, as well as with
the labors in which I have been engaged during my scientific career, in
measurements, experiments, and the investigation of facts, I limit myself to
the domain of empirical ideas.

The exposition of mutually connected facts does not exclude the
classification of phenomena according to their rational connection, the
generalization of many specialities in the great mass of observations, or the

attempt to discover laws. Conceptions of the universe solely based upon
reason, and the principles of speculative philosophy, would no doubt assign
a still more exalted aim to the science of the Cosmos. I am far from blaming
the efforts of others solely because their success has hitherto remained very
doubtful. Contrary to the wishes and counsel of of those profound and
powerful thinkers who p 76 have given new life to speculations which were
already familiar to the ancients, systems of natural philosophy have in our
own country for some time past turned aside the minds of men from the
graver study of mathematical and physical sciences. The abuse of better
powers, which has led many of our noble but ill-judging youth into the
saturnalia of a purely ideal science of nature, has been signalized by the
intoxication of pretended conquests, by a novel and fantastically symbolical
phraseology, and by a predilection for the formulae of a scholastic
rationalism, more contracted in its views than any known to the Middle
Ages. I use the expression "abuse of better powers," because superior
intellects devoted to philosophical pursuits and experimental sciences have
remained strangers to these saturnalia. The results yielded by an earnest
investigation in the path of experiment can not be at variance with a true
philosophy of nature. If there be any contradiction, the fault must lie either
in the unsoundness of speculation, or in the exaggerated pretensions of
empiricism, which thinks that more is proved by experiment than is actually
derivable from it.

External nature may be opposed to the intellectual world, as if the latter
were not comprised within the limits of the former, or nature may be
opposed to art when the latter is defined as a manifestation of the
intellectual power of man; but these contrasts, which we find reflected in
the most cultivated languages, must not lead us to separate the sphere of
nature from that of mind, since such a separation would reduce the physical
science of the world to a mere aggregation of empirical specialities. Science
does not present itself to man until mind conquers matter in striving to

subject the result of experimental investigation to rational combinations.
Science is the labor of mind applied to nature, but the external world has no
real existence for us beyond the image reflected within ourselves through
the medium of the senses. As intelligence and forms of speech, thought and
its verbal symbols, are united by secret and indissoluble links, so does the
external world blend almost unconsciously to ourselves with our ideas and
feelings. "External phenomena," says Hegel, in his 'Philosophy of History',
"are in some degree translated in our inner representations." The objective
world, conceived and reflected within us by thought, is subjected to the
eternal and necessary conditions of our intellectual being. The activity of
the mind exercises itself on the elements furnished to it by the perceptions
of the senses. Thus, in the p 77 early ages of mankind, there manifests itself
in the simple intuition of natural facts, and in the efforts made to
comprehend them, the germ of the philosophy of nature. These ideal
tendencies vary, and are more or less powerful, according to the individual
characteristics and moral dispositions of nations, and to the degrees of their
mental culture, whether attained amid scenes of nature that excite or chill
the imagination.

History has preserved the record of the numerous attempts that have been
made to form a rational conception of the whole world of phenomena, and
to recognize in the universe the action of one sole active force by which
matter is penetrated, transformed, and animated. These attempts are traced
in classical antiquity in those treatises on the principles of things which
emanated from the Ionian school, and in which all the phenomena of nature
were subjected to hazardous speculations, based upon a small number of
observations. By degrees, as the influence of great historical events has
favored the development of every branch of science supported by
observation, that ardor has cooled which formerly led men to seek the
essential nature and connection of things by ideal construction and in purely
rational principles. In recent times, the mathematical portion of natural

philosophy has been most remarkably and admirably enlarged. The method
and the instrument (analysis) have been simultaneously perfected. That
which has been acquired by means so different — by the ingenious
application of atomic suppositions, by the more general and intimate study
of phenomena, and by the improved construction of new apparatus — is the
common property of mankind, and shouldnot, in our opinion, now, more
than in ancient times, be withdrawn from the free exercise of speculative
thought.

It can not be denied that in this process of thought, the results of
experience have had to contend with many disadvantages; we must not,
therefore, be surprised if, in the perpetual vicissitude of theoretical views,
as is ingeniously expressed by the author of 'Giordano Bruno', "most men
see nothing in philosophy but a succession of passing meteors, while even
the grander forms in which she has revealed herself share the fate of
comets, bodies that do not rank in popular opinion among the eternal and
permanent works of nature, p 78 but are regarded as mere fugitive
apparitions of igncor vapor."

[Footnote] *Schelling's Bruno, 'eber das Gottliche und Naturaliche
Princip. der Dinge', 181 (Bruno, on the 'Divine and Natural Principle of
Things')

We would here remark that the abuse of thought, and the false track it too
often pursues, ought not to sanction an opinion derogatory to the intellect,
which would imply that the domain of mind is essentially a world of vague
fantastic illusions, and that the treasures accumulated by laborious
observations in philosophy are powers hostile to its own empire. It does not
become the spirit which characterizes the present age distrustfully to reject
every generalization of views and every attempt to examine into the nature

of things by the process of reason and induction. It would be a denial of the
dignity of human nature and the relative importance of the faculties with
which we are endowed, were we to condemn at one time austere reason
engaged in investigating causes and their natural connections, and at
another that exercise of the imagination which prompts and excites
discoveries by its creative powers.

This material taken from pages 79 to 111

COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1
by Alexander von Humboldt

Translated by E C Otte

from the 1858 Harper & Brothers edition of Cosmos, volume 1
—————————————————————————

p 79

COSMOS.

————————————-

DELINEATION OF NATURE. GENERAL REVIEW OF NATURAL PHENOMENA.

WHEN the human mind first attempts to subject to its control the world
of physical phenomena, and strives by meditative contemplation to
penetrate the rich luxuriance of living nature, and the mingled web of free
and restricted natural forces, man feels himself raised to a height from
whence, as he embraces the vast horizon, individual things blend together in
varied groups, and appear as if shrouded in a vapory vail. These figurative
expressions are used in order to illustrate the point of view from whence we

would consider the universe both in its celestial and terrestrial sphere. I am
not insensible of the boldness of such an undertaking. Among all the forms
of exposition to which these pages are devoted, there is none more difficult
than the general delineation of nature, which we purpose sketching, since
we must not allow ourselves to be overpowered by a sense of the
stupendous richness and variety of the forms presented to us, but must
dwell only on the consideration of masses either possessing actual
magnitude, or borrowing its semblance from the associations awakened
within the subjective sphere of ideas. It is by a separation and classification
of phenomena by an intuitive insight into the play of obscure forces, and by
animated expressions, in which the perceptible spectacle is reflected with
vivid truthfulness, that we may hope to comprehend and describe the
'universal all' [Greek words] in a manner worthy of the dignity of the word
'Cosmos' in its signification of 'universe, order of the world', and
'adornment' of this universal order. May the immeasurable diversity of
phenomena which crowd into the picture of nature in no way detract from
that harmonious impression of rest and unity which is the ultimate object of
every literary or purely artistical composition.

Beginning with the depths of space and the regions of remotest nebulae,
we will gradually descend through the starry zone to which our solar system
belongs, to our own terrestrial spheroid, circled by air and ocean, there to
direct our attention p 80 to its form, temperature, and magnetic tension, and
to consider the fullness of organic life unfolding itself upon its surface
beneath the vivifying influence of light. In this manner a picture of the
world may, with a few strokes, be made to include the realms of infinity no
less than the minute microscopic animal and vegetable organisms which
exist in standing waters and on the weather-beaten surface of our rocks. All
that can be perceived by the senses, and all that has been accumulated up to
the present day by an attentive and variously directed study of nature,
constitute the materials from which this representation is to be drawn,

whose character is an evidence of its fidelity and truth. But the descriptive
picture of nature which we purpose drawing must not enter too fully into
detail, since a minute enumeration of all vital forms, natural objects, and
processes is not requisite to the completeness of the undertaking. The
delineator of nature must resist the tendency toward endless division, in
order to avoid the dangers presented by the very abundance of our empirical
knowledge. A considerable portion of the qualitative properties of matter —
or, to speak more in accordance with the language of natural philosophy, of
the qualitative expression of forces — is doubtlessly still unknown to us,
and the attempt perfectly to represent unity in diversity must therefore
necessarily prove unsuccessful. Thus, besides the pleasure derived and
tinged with a shade of sadness, an unsatisfied longing for something beyond
the present — a striving toward regions yet unknown and unopened. Such a
sense of longing binds still faster the links which, in accordance with the
supreme laws of our being, connect the material with the ideal world, and
animates the mysterious relation existing between that which the mind
receives from without, and that which it reflects from its own depths to the
external world. If, then, nature (understanding by the term all natural
objects and phenomena) be illimitable in extent and contents, it likewise
presents itself to the human intellect as a problem which can not be grasped,
and whose solution is impossible, since it requires a knowledge of the
combined action of all natural forces. Such an acknowledgement is due
where the actual state and prospective development of phenomena
constitute the sole objects of direct investigation, which does not venture to
depart from the strict rules of induction. But, although the incessant effort to
embrace nature in its universality may remain unsatisfied, the history of the
contemplation of the universe (which p 81 will be considered in another
part of this work) will teach us how, in the course of ages, mankind has
gradually attained to a partial insight into the relative dependence of
phenomena. My duty is to depict the results of our knowledge in all their

bearings with reference to the present. In all that is subject to motion and
change in space, the ultimate aim, the very expression of physical laws,
depend upon 'mean numerical values', which show us the constant amid
change, and the stable amid apparent fluctuations of phenomena. Thus the
progress of modern physical science is especially characterized by the
attainment and the rectification of the mean values of certain quantities by
means of the processes of weighing and measuring; and it may be said, that
the only remaining and widely-diffused hieroglyphic characters still in our
writing — 'numbers' — appear to us again, as powers of the Cosmos,
although in a wider sense than that applied to them by the Italian School.

The earnest investigator delights in the simplicity of numerical relations,
indicating the dimensions of the celestial regions, the magnitudes and
periodical disturbances of the heavenly bodies, the triple elements of
terrestrial magnetism, the mean pressure of the atmosphere, and the
quantity of heat which the sun imparts in each year, and in every season of
the year, to all points of the solid and liquid surface of our planet. These
sources of enjoyment do not, however, satisfy the poet of Nature, or the
mind of the inquiring many. To both of these the present state of science
appears as a blank, now that she answers doubtingly, or wholly rejects as
unanswerable, questions to which former ages deemed they could furnish
satisfactory replies. In her severer aspect, and clothed with less luxuriance,
she shows herself deprived of that seductive charm with which a
dogmatizing and symbolizing physical philosophy knew how to deceive the
understanding and give the rein to imagination. Long before the discovery
of the New World, it was believed that new lands in the Far West might be
seen from the shores of the Canaries and the Azores. These illusive images
were owing, not to any extraordinary refraction of the rays of light, but
produced by an eager longing for the distant and the unattained. The
philosophy of the Greeks, the physical views of the Middle Ages, and even
those of a more recent period, have been eminently imbued with the charm

springing from similar illusive phantoms of the imagination. At the limits of
circumscribed knowledge, as from some lofty island shore, the eye delights
to penetrate p 82 to distant regions. The belief in the uncommon and the
wonderful lends a definite outline to every manifestation of ideal creation;
and the realm of fancy — a fairy-land of cosmological, geognostical, and
magnetic visions — becomes thus involuntarily blended with the domain of
reality.

Nature, in the manifold signification of the word — whether considered
as the universality of all that is and ever will be — as the inner moving
force of all phenomena, or as their mysterious prototype — reveals itself to
the simple mind and feelings of man as something earthly, and closely
allied to himself. It is only within the animated circles of organic structure
that we feel ourselves peculiarly at home. Thus, wherever the earth unfolds
her fruits and flowers, and gives food to countless tribes of animals, there
the image of nature impresses itself most vividly upon our senses. The
impression thus produced upon our minds limits itself almost exclusively to
the reflection of the earthly. The starry vault and the wide expanse of the
heavens belong to a picture of the universe, in which the magnitude of
masses, the number of congregated suns and faintly glimmering nebulae,
although they excite our wonder and astonishment, manifest themselves to
us in apparent isolation, and as utterly devoid of all evidence of their being
the scenes of organic life. Thus, even in the earliest physical views of
mankind, heaven and earth have been separated and opposed to one another
as an upper and lower portion of space. If, then, a picture of nature were to
correspond to the requirements of contemplation by the senses, it ought to
begin with a delineation of our native earth. It should depict, first, the
terrestrial planet as to its size and form; its increasing density and heat at
increasing depths in its superimposed solid and liquid strate; the separation
of sea and land, and the vital forms animating both, developed in the
cellular tissues of plants and animals; the atmospheric ocean, with its waves

and currents, through which pierce the forest-crowned summits of our
mountain chains. After this delineation of purely telluric relations, the eye
would rise to the celestial regions, and the Earth would then, as the well-
known seat of organic development, be considered as a planet, occupying a
place in the series of those heavenly bodies which circle round one of the
innumerable host of self-luminous stars. This succession of ideas indicates
the course pursued in the earliest stages of perceptive contemplation, and
reminds us of the ancient conception of the "sea-girt disk of earth,"
supporting the vault of heaven. It begins to exercise in action p 83 at the
spot where it originated, and passes from the consideration of the known to
the unknown, of the near to the distant. It corresponds with the method
pursued in our elementary works on astronomy (and which is so admirable
in a mathematical point of view), of proceeding from the apparent to the
real movements of the heavenly bodies.

Another course of ideas must, however, be pursued in a work which
proposes merely to give an exposition of what is known — of what may in
the present state of our knowledge be regarded as certain, or as merely
probable in a greater or lesser degree — and does not enter into a
consideration of the proofs on which such results have been based. Here,
therefore, we do not proceed from the subjective point of view of human
interests. The terrestrial must be treated only as grand and free,
uninfluenced by motives of proximity, social sympathy, or relative utility. A
physical cosmography — a picture of the universe — does not begin,
therefore, with the picture of the universe — does not begin, therefore, with
the terrestrial, but with that which fills the regions of space. But as the
sphere of contemplation contracts in dimension our perception of the
richness of individual parts, the fullness of physical phenomena, and of the
heterogeneous properties of matter becomes enlarged. From the regions in
which we recognize ony the dominion of the laws of attraction, we descend
to our own planet, and to the intricate play of terrestrial forces. The method

here described for the delineation of nature is opposed to that which mst be
pursued in establishing conclusive results. The one enumerates what the
other demonstrates.

Man learns to know the external world through the organs of the senses.
Phenomena of light proclaim the existence of matter in remotest space, and
the eye is thus made the medium through which we may contemplate the
universe. The discovery of telescopic vision more than two centuries ago,
has transmitted to latest generations a power whose limits are as yet
unattained.

The first and most general consideration of the Cosmos is that of the
'contents of space' — the distribution of matter, or of creation, as we are
wont to designate the assemblage of all that is and ever will be developed.
We see matter either agglomerated into rotating, revolving spheres of
different density and size, or scattered through space in the form of self-
luminous vapor. If we consider first the cosmical vapor dispersed in definite
nebulous spots, its state of aggregation will p 84 appear constantly to vary,
sometimes appearing separated into round or elliptical disks, single or in
pairs, occasionally connected by a thread of light; while, at another time,
these nebulae occur in forms of larger dimensions, and are either elongated,
or variously branched or fan-shaped or appear like well-defined rings,
including a dark interior. It is conjectured that these bodies are undergoing
variously developed formative processes, as the cosmical vapor becomes
condensed in conformity with the laws of attraction, either round one or
more of the nuclei. Between two and three thousand of such unresolvable
nebulae, in which the most powerful telescopes have hitherto been unable
to distinguish the presence of stars, have been counted, and their positions
determined.

The genetic evolution — that perpetual state of development which
seems to affect this portion of the regions of space — has led philosophical
observers to the discovery of the analogy existing among organic
phenomena. As in our forests we see the same kind of tree in all the various
stages of its growth, and are thus enabled to form an idea of progressive,
vital development, so do we also in the great garden of the universe,
recognise the most different phases of sidereal formation. The process of
condensation, which formed a part of the doctrines of Anaximenes and of
the Ionian School, appears to be going on before our eyes. This subject of
investigation and conjecture is especially attractive to the imagination, for
in the study of the animated circles of nature, and of the action of all the
moving forces of the universe, the charm that exercises the most powerful
influence on the mind is derived less from a knowledge of that which 'is'
than from a perception of that which 'will be', even though the latter be
nothing more than a new condition of a known material existence; for of
actual creation, of origin, the beginning of existence from non-existence, we
have no experience, and can therefore form no conception.

A comparison of the various causes influencing the development
manifested by the greater or less degree of condensation in the interior of
nebulae, no less than a successive course of direct observations, have led to
the belief that changes of form have been recognized first in Andromeda,
next in the constallation Argo, and in the isolated filamentous portion of the
nebula in Orion. But want of uniformity in the power of the instruments
employed, different conditions of our atmosphere, and other optical
relations, render a part of the results invalid as historical evidence.

p 85 'Nebulous stars' must not be confounded either with irregularly-
shaped nebulous spots, properly so called, whose separate parts have an
unequal degree of brightness (and which may, perhaps, become
concentrated into stars as their circumference contracts), nor with the so-

called planetary nebulae, whose circular or slightly oval disks manifest in
all their parts a perfectly uniform degree of faint light. 'Nebulous stars' are
not merely accidental bodies projected upon a nebulous ground, but are a
part of the nebulous matter constituting one mass with the body which it
surrounds. The not unfrequently considerable magnitude of their apparent
diameter, and the remote distance from which they are revealed to us, show
that both the planetary nebulae and the nebulous stars must be of enormous
dimensions. New and ingenious considerations of the different influence
exercised by distance* on the intensity of light of a disk of appreciable
diameter, and of a single self-luminous point, render it not improbable that
the planetary nebulae are very remote nebulous stars, in which the
difference between the central body and the surrounding nebulous covering
can no longer be detected by our telescopic instruments.

[footnote] * The optical considerations relative to the difference
presented by a single luminous point, and by a disk subtending an
appreciable angle, in which the intensity of light is constant at every
distance, are explained in Arago's 'Analyse des Travaux de Sir William
Herschel' ('Annuaire du Bureau des Long.', 1842, p. 410-412, and 441).

The magnificent zones of the southern heavens, between 50 degrees and
80 degrees, are especially rich in nebulous stars, and in compressed
unresolvable nebua e. The larger of the two Magellanic clouds, which circle
round the starless, desert pole of the south, appears, according to the most
recent researches,* as "a collection of clusters of stars, composed of
globular clusters and nebulae of different magnitude, and of large nebulous
spots

p 86 not resolvable, which, producing a general brightness in the field of
view, form, as it were, the back-ground of the picture."

[footnote] *The two Magellanic clouds, Nubecula major and Nubecula
minor, are very remarkable objects. The larger of the two is an accumulated
mass of stars, and consists of clusters of stars of irregular form, either
conical masses or nebulae of different magnitudes and degrees of
condensation. This is interspersed with nebulous spots, not resolvable into
stars, but which are probably 'star dust', appearing only as a general
radiance upon the telescopic field of a twenty-feet reflector, and forming a
luminous ground on which other objects of striking and indescribable form
are scattered. In no other portion of the heavens are so many nebulous and
stellar masses thronged together in an equally small space. Nubecula minor
is much less beautiful, has more unresolvable nebulous light, while the

stellar masses are fewer and fainter in intensity. — (From a letter of Sir
John Herschel, Feldhuysen, Cape of Good Hope, 13th June, 1836.)

The appearance of these clouds, of the brightly-beaming constellation
Argo, of the Milky Way between Scorpio, the Centaur, and the Southern
Cross, the picturesque beauty, if one may so speak, of the whole expanse of
the southern celestial hemisphere, has left upon my mind an ineffaceable
impression. The zodiacal light, which rises in a pyramidal form, and
constantly contributes, by its mild radiance, to the external beauty of the
tropical nights, is either a vast nebulous ring, rotating between the Earth and
Mars, or, less probably, the exterior stratum of the solar atmosphere.
Besides these luminous clouds and nebulae of definite form, exact and
corresponding observations indicate the existence and the general
distribution of an apparently non-luminous, infinitely-divided matter, which
posssesses a force of resistance and manifests its presence in Encke's, and
perhaps also in Biela's comet, by diminishing their eccentricity and
shortening their period of revolution. Of this impending, ethereal, and
cosmical matter, it may be supposed that it is in motion; that it gravitates,
notwithstanding its original tenuity; that it is condensed in the vicinity of
the great mass of the Sun; and, finally, that it may, for myriads of ages, have
been augmented by the vapor emanating from the tails of comets.

If we now pass from the consideration of the vaporous matter of the
immeasurable regions of space [(Greek)*] — whether scattered without
definite form and limits, it exists as a cosmical other, or is condensed into
nebulous spots, and becomes comprised among the solid agglomerated
bodies of the universe — we approach a class of phenomena exclusively
designated by the form of stars, or as the sidereal world.

[footnote] *I should have made use, in the place of garden of the
universe, of the beautiful expression [Greek], borrowed by Hesychius from
an unknown poet, if [Greek] had not rather signified in general an inclosed
space. The connection with the German 'garten' and the English 'garden',
'gards' in Gothic (derived according to Jacob Grimm, from 'gairdan', 'to
gird'), is, however, evident, as is likewise the affinity with the Slavonic
'grad', 'gorod', and as Pott remarks, in his 'Etymol. Forschungen', th. i., s.
144 (Etymol. Researches), with the Latin 'chors', whence we have the
Spanish 'corte', the French 'cour', and the English word 'court', together with
the Ossetic 'khart'. To these may be further added the Scandinavian 'gard',**
'gard', a place inclosed, as a court, or a country seat, and the Persian 'gerd',
'gird', a district, a circle, a princely country seat, a castle or city, as we find
the term applied to the names of places in Firdusi's Schahnameh, as
'Siyawakschgird', 'Darabgird', etc.

** (This word is written 'gaard' in the Danish) — Tr.

p 87 Here, too, we find differences existing in the solidity or density of
the spheroidally agglomerated matter. Our own solar system presents all
stages of 'mean' density (or of the relation of 'volume' to 'mass'.) On
comparing the planets from Mercury to Mars with the Sun and with Jupiter,
and these two last named with the yet inferior density of Saturn, we arrive,
by a descending scale — to draw our illustration from the terrestrial
substances — at the respective densities of antimony, honey, water, and
pine wood. In comets, which actually constitute the most considerable
portion of our solar system with respect to the number of individual forms,
the concentrated part, usually termed the 'head', or 'nucleus', transmits
sidereal light unimpaired. The mass of a comet probably in no case equals
the five thousandth part of that of the earth, so dissimilar are the formative
processes manifested in the original and perhaps still progressive

agglomerations of matter. In proceeding from general to special
considerations, it was particularly desirable to draw attention to this
diversity, not merely as a possible, but as an actually proved fact.

The purely speculative conclusions arrived at by Wright, Kant, and
Lambert, concerning the general structural arrangement of the universe, and
of the distribution of matter in space, have been confirmed by Sir William
Herschel, on the more certain path of observation and measurement. That
great and enthusiastic, although cautious observer, was the first to sound the
depths of heaven in order to determine the limits and form of the starry
stratum which we inhabit, and he, too, was the first who ventured to throw
the light of investigation upon the relations existing between the position
and distance of remote nebulae and our own portion of the sidereal
universe. William Herschel, as is well expressed in the elegant inscription
on his monument at Upton, broke through the inclosures of heaven
('caelorum perrupit claustra'), and, like another Columbus, penetrated into
an unknown ocean, from which he beheld coasts and groups of islands,
whose true position it remains for future ages to determine.

Considerations regarding the different intensity of light in stars, and their
relative number, that is to say, their numerical frequency on telescopic fields
of equal magnitude, have led to the assumption of unequal distances and
distribution in space in the strata which they compose. Such assumptions, in
as far as they may lead us to draw the limits of the individual portions of the
universe, can not offer the same degree of mathematical certainty as that
which may be attained in all that p 88 relates to our solar system, whether
we consider the rotation of double stars with unequal velocity round one
common center of gravity, or the apparent or true movements of all the
heavenly bodies. If we take up the physical description of the universe from
the remotest nebulae, we may be inclined to compare it with the mythical
portions of history. The one begins in the obscurity of antiquity, the other in

that of inaccessible space; and at the point where reality seems to flee
before us, imagination becomes doubly incited to draw from its own
fullness, and give definite outline and permanence to the changing forms of
objects.

If we compare the regions of the universe with one of the island-studded
seas of our own planet, we may imagine matter to be distributed in groups,
either as unresolvable nebulae of different ages, condensed around one or
more nuclei, or as already agglomerated into clusters of stars, or isolated
spheroidal bodies. The cluster of stars, to which our cosmical island
belongs, forms a lens-shaped, flattened stratum, detached on every side,
whose major axis is estimated at seven or eight hundred, and its minor one
at a hundred and fifty times the distance of Sirius. It would appear, on the
supposition that the parallax of Sirius is not greater than that accurately
determined for the brightest star in the Centaur (0".9128), that light
traverses one distance of Sirius in three years, while it also follows, from
Bessel's earlier excellent Memoir* on the parallax of the remarkable star 61
Cygni (0".3483), (whose considerable motion might lead to the inference of
great proximity), that a period of nine years and a quarter is required for the
transmission of light from this star to our planet.

[footnote] *See Maclear's "Results from 1839 to 1840," in the 'Trans. of
the Astronomical Soc.', vol. xii., p. 370, on 'a' Centauri, the probable mean
error being 0".0649. For 61 Cygni, see Bessel, in Schumacher's 'Jahrbuch',
1839, s. 47, and Schumacher's 'Astron. Nachr.', bd. xviii., s. 401, 402,
probable mean error, 0".0141. With reference to the relative distances of
stars of different magnitudes, how those of the third magnitude may
probably be three times more remote, and the manner in which we represent
to ourselves the material arrangement of the starry strata, I have found the
following remarkable passage in Kepler's 'Epitome Astronomiae

Copernicanae', 1618, t. i., lib. 1, p. 34-39: "Sol hic noster nil aliud est quam
una ex fixis, nobis major et clarior visa, quia propior quam fixa. Pone
terram stare ad latus, una semi-diametro via e lactea e, tunc ha ec via lactea
apparebit circulus parvus, vel ellipsis parva, tota declinans ad latus alterum;
eritque simul uno intuitu conspicua, quae nunc no potest nisi dimidia
conspici quovis momento. Itaque fix arum spha era non tantum orbe
stellarum, sed etiam circulo lactis versus not deorsum est terminata."

Our starry stratum is a disk of inconsiderable thickness, divided a p 89
third of its length into two branches; it is supposed that we are near this
division, and nearer to the region of Sirius than to the constellation Aquila,
almost in the middle of the stratum in the line of its thickness or minor axis.

This position of our solar system, and the form of the whole discoidal
stratum, have been inferred from sidereal scales, that is to say, from that
method of counting the stars to which I have already alluded, and which is
based upon the equidistant subdivision of the telescopic field of view. The
relative depth of the stratum in all directions is measured by the greater or
smaller number of stars appearing in each division. These divisions give the
length of the ray of vision in the same manner as we measure the depth to
which the plummet has been thrown, before it reaches the bottom, although
in the case of a starry stratum there can not, correctly speaking, be any idea
of depth, but merely of outer limits. In the direction of the longer axis,
where the stars lie behind one another, the more remote ones appear closely
crowded together, united, as it were, by a milky-white radiance or luminous
vapor, and are perspectively grouped, encircling as in a zone, the visible
vault of heaven. This narrow and branched girdle, studded with a radiant
light, and here and there interrupted by dark spots, deviates only by a few
degrees from forming a perfect large circle round the concave sphere of
heaven, owing to our being near the center of the large starry cluster, and

almost on the plane of the Milky Way. If our planetary system were far
'outside' this cluster, the Milky Way would appear to telescopic vision as a
ring, and at a still greater distance as a resolvable discoidal nebula.

Among the many self-luminous moving suns, erroneously called 'fixed
stars', which constitute our cosmical island, our own sun is the only one
known by direct observation to be a 'central body' in its relations to
spherical agglomerations of matter directly depending upon and revolving
round it, either in the form of planets, comets, or aerolite asteroids. As far as
we have hitherto been able to investigate 'multiple' stars (double stars or
suns), these bodies are not subject, with respect to relative motion and
illumination, to the same planetary dependence that characterizes our own
solar system. Two or more self-luminous bodies, whose planets and moon,
if such exist, have hitherto escaped our telescopic powers of vision,
certainly revolve around one common center of gravity; but this is in a
portion of space which is probably occupied merely by unagglomerated
matter or cosmical vapor, while in our system p 90 the center of gravity is
often comprised within the innermost limits of a 'visible' central body. If,
therefore, we regard the Sun and the Earth, or the Earth and the Moon, as
double-stars, and the whole of our planetary solar system as a multiple
cluster of stars, the analogy thus suggested must be limited to the
universality of the laws of attraction in different systems, being alike
applicable to the independent processes of light and to the method of
illumination.

For the generalization of cosmical views, corresponding with the plan we
have proposed to follow in giving a delineation of nature or of the universe,
the solar system to which the Earth belongs may be considered in a two-
fold relation: first, with respect to the different classes of individually
agglomerated matter, and the relative size, conformation, density, and
distance of the heavenly bodies of this system; and secondly, with reference

to other portions of our starry cluster, and of the changes of position of its
central body, the Sun.

The solar system, that is to say, the variously-formed matter circling
round the Sun, consists, according to the present state of our knowledge of
'eleven primary planets',* eighteen satellites p 91 or secondary planets, and
myriads of comets, three of which, known as the "planetary comets," do not
pass beyond the narrow limits of the orbits described by the principal
planets.

[footnote] * (Since the publication of Baron Humboldt's work in 1845,
several other planets have been discovered, making the number of those
belonging to our planetary system 'sixteen' instead of 'eleven'. Of these,
Astrea, Hebe, Flora, and Iris are members of the remarkable group of
asteroids between Mars and Jupiter. Astrea and Hebe were discovered by
Hencke at Driesen, the one in 1846 and the other in 1847; Flora and Iris
were both discovered in 1847 by Mr. Hind, at the South Villa Observatory,
Regent's Park. It would appear from the latest determinations of their
elements, that the small planets have the following order with respect to
mean distance from the Sun: Flora, Iris, Vesta, Hebe, Astrea, Juno, Ceres,
Pallas. Of these, Flora has the shortest period (about 3 1/4 years). The
planet Neptune, which, after having been predicted by several astronomers,
was actually observed on the 25th of September, 1846, is situated on the
confines of our planetary system beyond Uranus. The discovery of this
planet is not only highly interesting from the importance attached to it as a
question of science, but also from the evidence it affords of the care and
unremitting labor evinced by modern astronomers in the investigation and
comparison of the older calculations, and the ingenious application of the
results thus obtained to the observation of new facts. The merit of having
paved the way for the discovery of the planet Neptune is due to M.

Bouvard, who, in his persevering and assiduous efforts to deduce the entire
orbit of Uranus from observations made during the forty years that
succeeded the discovery of that planet in 1781, found the results yielded by
theory to be at variance with fact, in a degree that had no parallel in the
history of astronomy. This startling discrepancy, which seemed only to gain
additional weight from every attempt made by M. Bouvard to correct his
calculations, led Leverrier, after a careful modification of the tables of
Bouvard, to establish the proposition that there was "a formal
incompatibility between the observed motions of Uranus and the hypothesis
that he was acted on 'only' by the Sun and known planets, according to the
law of universal gravitation." Pursuing this idea, Leverrier arrived at the
conclusion that the disturbing cause must be a 'planet', and finally, after an
amount of labor that seems perfectly overwhelming, he, on the 31st of
August, 1846, laid before the French Institute a paper, in which he indicated
the exact spot in the heavens where this new planetary body would be
found, giving the following data for its various elements: mean distance
from the Sun, 36.154 times that of the Earth; period of revolution, 217.387
years; mean long., Jan. 1st, 1847, 318 degrees 47'; mass, 1/9300th;
heliocentric long., Jan 1st1847, 326 degrees 32'. Essential difficulties still
intervened, however, and as the remoteness of the planet rendered it
improbable that its disk would be discernible by any telescopic instrument,
no other means remained for detecting the suspected body but its planetary
motion, which could only be ascertained by mapping, after every
observation, the quarter of the heavens scanned, and by a comparison of the
various maps. Fortunately for the verification of Leverrier's predictions, Dr.
Bremiker had just completed a map of the precise region in which it was
expected the new planet would apper, this being one of a series of maps
made for the Academy of Berlin, of the small stars along the entire zodiac.
By means of this valuable assistance, Dr. Galle, of the Berlin Observatory,
was led, on the 25th of September, 1846, by the discovery of a star of the

eighth magnitude, not recorded in Dr. Bremiker's map, to make the first
observation of the planet predicted by Leverrier. By a singular coincidence,
Mr. Adams, of Cambridge, had predicted the appearance of the planet
simultaneously with M. Leverrier; but by the concurrence of several
circumstances much to be regretted, the world at large were not made
acquainted with Mr. Adams's valuable discovery until subsequently to the
period at which Leverrier published his observations. As the data of
Leverrier and Adams stand at present, there is a discrepancy between the
predicted and the true distance, and in some other elements of the planet; it
remains therefore, for these or future astronomers to reconcile theory with
fact, or perhaps, as in the case of Uranus, to make the new planet the means
of leading to yet greater discoveries. It would appear from the most recent
observations, that the mass of Neptune, instead of being, as at first stated,
1/9300th, is only about 1/23000th that of the Sun, while its periodic time is
now given with a greater probability at 166 years, and its mean distance
from the Sun nearly 30. The planet appears to have a ring, but as yet no
accurate observations have been made regarding its system of satellites. See
'Trans. Astron. Soc.', and 'The Planet Neptune', 1848, by J. P. Nicholl.) —
Tr.

We may, with no incondsiderable degree of probability, include within
the domain of our Sun, in the immediate sphere of its central force, a
rotating ring of vaporous matter, lying probably between the orbits of Venus
and Mars, but certainly beyond that of the Earth,* which appears to us in p
92 a pyramidal form, and is known as the 'Zodiacal Light'; and a host of
very small asteroids, whose orbits either intersect, or very nearly approach,
that of our earth, and which present us with the phenomena of aerolites and
falling or shooting stars.

[footnote] * "If there should be molecules in the zones diffused by the
atmosphere of the Sun of too volatile a nature either to combine with one
another or with the planets, we must suppose that they would, in circling
round that luminary, present all the appearances of zodiacal light, without
opposing any appreciable resistance to the different bodies composing the
planetary system, either owing to their extreme rarity, or to the similarity
existing between their motion and that of the planets with which they come
in contact." — Laplace, 'Expos. du Syst. du Monde' (ed. 5), p. 415.

When we consider the complication of variously-formed bodies which
revolve round the Sun in orbits of such dissimilar eccentricity—although
we may not be disposed, with the immortal author of the 'Mecanique
Celeste', to regard the largr number of comets as nebulous stars, passing
from one central system to another,* we yet can not fail to acknowledge
that the planetary system, especially so called (that is, the group of heavenly
bodies which, together with their satellites, revolve with but slightly
eccentric orbits round the Sun), constitutes but a small portion of the whole
system with respect to individual numbers, if not to mass.

[footnote] *Laplace, 'Exp. du Syst. du Monde', p. 396, 414.

It has been proposed to consider the telescopic planets, Vesta, Juno,
Ceres, and Pallas, with their more closely intersecting, inclined, and
eccentric orbits, as a zone of separation, or as a middle group in space; and
if this view be adopted, we shall discover that the interior planetary group
(consisting of Mercury, Venus, the Earth, and Mars) presents several very
striking contrasts* when compared with the exterior group, comprising
Jupiter, Saturn, and Uranus.

[footnote] *Littrow, 'Astronomie', 1825, bd.xi., 107. Mädler, 'Astron.',
1841, § 212. Laplace, 'Exp. du Syst. du Monde', p. 210.

The planets nearest the Sun, and consequently included in the inner
group, are of more moderate size, denser, rotate more slowly and with
nearly equal velocity (their periods of revolution being almost all about 24
hours), are less compressed at the poles, and with the exception of one, are
without satellites. The exterior planets, which are further removed from the
Sun, are very considerably larger, have a density five times less, more than
twice as great a velocity in the period of their rotation round their axes, are
more compressed at the poles, and if six satellites may be ascribed to
Uranus, have a quantitative preponderance in the number of their attendant
moons, which is as seventeen to one.

p 93 Such general considerations regarding certain characteristic
properties appertaining to whole groups, can not, however, be applied with
equal justice to the individual planets of every group, nor to the relations
between the distances of the revolving planets from the central body, and
their absolute size, density, period or rotation, eccentricity, and the
inclination of their orbits and the axes. We know as yet of no inherent
necessity, no mechanical natural law, similar to the one which teaches us
that the squares of the periodic times are proportional to the cubes of the
major axes, by which the above-named six elements of the planetary bodies
and the form of their orbit are made dependent either on one another, or on
their mean distance from the Sun. Mars is smaller than the Earth and Venus,
although further removed from the Sun than these last-named planets,
approaching most nearly in size to Mercury, the nearest planet to the Sun.
Saturn is smaller than Jupiter, and yet much larger than Uranus. The zone of
the telescopic planets, which have so inconsiderable a volume, immediately
procede Jupiter (the greatest in size of any of the planetary bodies), if we

consider them with regard to distance from the Sun; and yet the disks of
these small asteroids, which scarcely admit of measurement, have an areal
surface not much more than half that of France, Madagascar, or Borneo.
However striking may be the extremely small density of all the colossal
planets, which are furthest removed from the Sun, we are yet unable in this
respect to recognize any regular succession.*

[footnote] *See Kepler, on the increasing density and volume of the
planets in proportion with their increase of distance from the Sun, which is
described as the densest of all the heavenly bodies; in the 'Epitome Astran.
Copern. in' vii. 'libros digesta', 1618-1622, p. 420. Leibnitz also inclined to
the opinions of Kepler and Otto von Guericke, that the planets increase in
volume in proportion to their increase of distance from the Sun. See his
letter to the Magdeburg Burgomaster (Mayence, 1671), in Leibnitz,
'Deutschen Schriften, herausg. von Guhrauer', th. i., 264.

Uranus appears to be denser than Saturn, even if we adopt the smaller
mass, 1/24605, assumed by Lamont; and, notwithstanding the
inconsiderable difference of density observed in the innermost planetary
group,* we find both Venus and Mars less dense than the Earth, which lies
between them.

[footnote] *On the arrangement of masses, see Encke, in Schum., 'Astr.
Nachr', 1843 Nr. 488, 114.

The time of rotation certainly diminishes with increasing solar distance,
but yet it is greater in Mars than in the Earth, and in Saturn than in Jupiter.
The elliptic p 94 orbits of Juno, Pallas, and Mercury have the greatest
degree of eccentricity, and Mars and Venus, which immediately follow each

other, have the least. Mercury and Venus exhibit the same contrasts that
may be observed in the four smaller planets, or asteroids, whose paths are
so closely interwoven.

The eccentriciities of Juno and Pallas are very nearly identical, and reach
three times as great as those of Ceres and Vesta. The same may be said of
the inclination of the orbits of the planets toward the plane of projection of
the ecliptic, or in the position of their axes of rotation with relation to their
orbits, a position on which the relations of climate, seasons of the year, and
length of the days depend more than on eccentricity. Those planets that
have the most elongated elliptic orbits, as Juno, Pallas, and Mercury, have
also, although not to the same degree their orbits most strongly inclined
toward the ecliptic. Pallas has a comet-like inclination nearly twenty-six
times greater than that of Jupiter, while in the little planet Vesta, which is so
near Pallas, the angle of inclination scarcely by six times exceeds that of
Jupiter. An equally irregular succession is observed in the position of the
axes of the few planets (four or five) whose planes of rotation we know
with any degree of certainty. It would appear from the position of the
satellites of Uranus, two of which, the second and fourth, have been
recently observed with certainty, that the axis of this, the outermost of all
the planets is scarcely inclined as much as 11 degrees toward the plane of
its orbit, while Saturn is placed between this planet, whose axis almost
coincides with the plane of its orbit, and Jupiter, whose axis of rotation is
nearly perpendicular to it.

In this enumeration of the forms which compose the world in space, we
have delineated them as possessing an actual existence, and not as objects
of intellectual contemplation, or as mere links of a mental and causal chain
of connection. The planetary system, in its relations of absolute size and
relative position of the axes, density, time of rotation, and different degrees
of eccentricity of the orbits, does not appear to offer to our apprehension

any stronger evidence of a natural necessity than the proportion observed in
the distribution of land and water on the Earth, the configuration of
continents, or the height of mountain chains. In these respects we can
discover no common law in the regions of space or in the inequalities of the
earth's crust. They are 'facts' in nature that have arisen from the conflict of
manifold forces acting under unknown p 95 conditions, although man
considers as 'accidental' whatever he is unable to explain in the planetary
formation on purely genetic principles. If the planets have been formed out
of separate rings of vaporous matter revolving round the Sun, we may
conjecture that the different thickness, unequal density, temperature, and
electro-magnetic tension of these rings may have given occasion to the most
various agglomerations of matter, in the same manner as the amount of
tangential velocity and small variations in its direction have produced so
great a differencein the forms and inclinations of the elliptic orbits.
Attractions of mass and laws of gravitation have no doubt exercised an
influence here, no less than in the geognostic relations of the elevations of
continents; but we are unable from the present forms to draw any
conclusions regarding the series of conditions through which they have
passed. Even the so-called law of the distances of the planets from the Sun,
the law of progression (which led Kepler to conjecture the existence of a
planet supplying the link that was wanting in the chain of connection
between Mars and Jupiter), has been found numerically inexact for the
distances between Mercury, Venus, and the Earth, and a variance with the
conception of a series, owing to the necessity for a supposition in the case
of the first member.

The hitherto disscovered principal planets that revolve round our Sun are
attended certainly by fourteen, and probably by eighteen secondary planets
(moons or satellites). The principal planets are, therefore, themselves the
central bodies of subordinate systems. We seem to recognize in the fabric of
the universe the same process of arrangement so frequently exhibited in the

development of organic life, where we find in the manifold combinations of
groups of plants or animals the same typical form repeated in the
'subordinate classes'. The secondary planets or satellites are more frequent
in the external region of the planetary system, lying beyond the intersecting
orbits of the smaller planets or asteroids; in the inner region none of the
planets are attended by satellites, with the exception of the Earth, whose
moon is relatively of great magnitude, since its diameter is equal to a fourth
of that of the Earth, while the diameter of the largest of all known
secondary planets — the sixth satellite of Saturn — is probably about one
seventeenth, and the largest of Jupiter's moons, the third, only about one
twenty-sixth part that of the primary planet or central body. The planets
which are attended by the largest number of satellites are most remote from
the Sun, p 96 and are at the same time the largest, most compressed at the
poles, and the least dense. According to the most recent measurements of
Mädler, Uranus has a greater planetary compression than any other of the
planets, viz., 1/9.92d. In our Earth and her moon, whose mean distance
from one another amounts to 207,200 miles, we find that the differences of
mass* and diameter between the two are much less considerable than are
usually observed to exist between the principal planets and their attendant
satellites, or between bodies of different orders in the solar system.

[footnote] *If, according to Burckhardt's determination, the Moon's
radius be 0.2725 and its volume 1/49.00th, its density will be 0.5596, or
nearly five ninths. Compare, also, Wilh. Beer and H. Madler, 'der Mond', 2,
10, and Madler, 'Ast.', 157. The material contents of the Moon are,
according to Hansen, nearly 1/34th (and ädler 1/40.6th) that of the Earth,
and its mass equal to 1/87.73d that of the Earth. In the largest of Jupiter's
moons, the third, the relations of volume to the central body are 1/15370th,
and of mass 1/11300th. On the polar flattening of Uranus, see Schum,
'Astron. Nachr.', 1844, No. 493.

While the density of the Moon is five ninths less than that of the Earth, it
would appear, if we may sufficiently depend upon the determinations of
their magnitudes and masses, that the second of Jupiter's moons is actually
denser than that great planet itself. Among the fourteen satellites that have
been investigated with any degree of certainty, the system of the seven
satellites of Saturn presents an instance of the greatest possible contrast,
both in absolute magnitude and in distance from the central body. The sixth
of these satellites is probably not much smaller than Mars, while our moon
has a diameter which does not amount to more than half that of the latter
planet. With respect to volume, the two outer, the sixth and seventh of
Saturn's satellites, approach the nearest to the third and brightest of Jupiter's
moons. The two innermost of these satellites belong perhaps, together with
the remote moons of Uranus to the smallest cosmical bodies of our solar
system, being only made visible under favorable circumstances by the most
powerful instruments. They were first discovered by the forty-foot telescope
of William Herschel in 1789, and were seen again by John Herschel at the
Cape of Good Hope, by Vico at Rome, and by Lamont at Munich.
Determinations of the 'true' diameter of satellites, made by the measurement
of the apparent size of their small disks, are subjected to many optical
difficulties; but numerical astronomy, whose task it is to predetermine by
calculation the motions of the heavenly bodies as they will appear when
viewed from the Earth, is directed almost p 97 exclusively to motion and
mass, and but little to volume. The absolute distance of a satellite from its
central body is greatest in the case of the outermost or seventh satellite of
Saturn, its distance from the body round which it revolves amounting to
more than two millions of miles, or ten times as great a distance as that of
our moon from the Earth. In the case of Jupiter we find that the outermost
or fourth attendant moon is only 1,040,000 miles from that planet, while the
distance between Uranus and its sixth satellite (if the latter really exist)
amounts to as much as 1,360,000 miles. If we compare, in each of these

subordinate systems, the volume of the satellite, we discover the existence
of entirely new numerical relations. The distances of the outermost satellites
of Uranus, Saturn, and Jupiter are when expressed in semi-diameters of the
main planets, as 91, 64, and 27. The outermost satellite of Saturn appears,
therefore, to be removed only about one fifteenth further from the center of
that planet than our moon is from the Earth. The first or innermost of
Saturn's satellites is nearer to its central body than any other of the
secondary planets, and presents, moreover, the only instance of a period of
revolution of less than twenty-four hours. Its distance from the center of
Saturn may, according to Mädler and Wilhelm Beer, be expressed as 2.47
semi-diameters of that planet, or as 80,088 miles. Its distance from the
surface of the main planet is therefore 47,480 miles, and from the outer-
most edge of the ring only 4916 miles. The traveler may form to himself an
estimate of the smallness of this amount by remembering the statement of
an enterprising navigator, Captain Beechey, that he had in three years
passed over 72,800 miles. If, instead of absolute distances, we take the
semi-diameters of the principal planets, we shall find that even the first or
nearest of the moons of Jupiter (which is 26,000 miles further removed
from the center of that planet than our moon is from that of the Earth) is
only six semi-diameters of Jupiter from its center, while our moon is
removed from us fully 60 1/3d semi-diameters of the Earth.

In the subordinate systems of satellites, we find that the same laws of
gravitation which regulate the revolutions of the principal planets round the
Sun likewise govern the mutual relations existing between these planets
among one another and with reference to their attendant satellites. The
twelve moons of Saturn, Jupiter, and the Earth all most like the primary
planets from west to east, and in elliptic orbits, deviating p 98 but little from
circles. It is only in the case of one moon, and perhaps in that of the first
and innermost of the satellites of Saturn (0.068), that we discover an
eccentricity greater than that of Jupiter; according to the very exact

observations of Bessel, the eccentricity of the sixth of Saturn's satellites
(0.029) exceeds that of the Earth. On the extremest limits of the planetary
system, where, at a distance nineteen times greater than that of our Earth,
the centripetal force of the Sun is greatly diminished, the satellites of
Uranus (which most striking contrasts from the facts observed with regard
to other secondary planets. Instead, as in all other satellites, of having their
orbits but slightly inclined toward the ecliptic and (not excepting even
Saturn's ring, which may be regarded as a fusion of agglomerated satellites)
moving from west to east, the satellites of Uranus are almost perpendicular
to the ecliptic, and move retrogressively from east to west, as Sir John
Herschel has proved by observations continued during many years. If the
primary and secondary planets have been formed by the condensation of
rotating rings of solar and planetary atmospheric vapor, there must have
existed singular causes of retardation or impediment in the vaporous rings
revolving round Uranus, by which, under the relations with which we are
unacquainted, the revolution of the second and fourth of its satellites was
made to assume a direction opposite to that of the rotation of the central
planet.

It seems highly probable that the period of rotation of 'all' secondary
planets is equal to that of their revolution round the main planet, and
therefore that they always present to the latter the same side. Inequalities,
occasioned by sight variations in the revolution, give rise to fluctuations of
from 6 degrees to 8 degrees, or to an apparent libration in longitude as well
as in latitude. Thus, in the case of our moon, we sometimes observe more
than the half of its surface, the eastern and northern edges being more
visible at one time, and the western or southern at another. By means of this
libration* we are enabled to see the annular mountain Malapert (which
occasionally conceals the Moon's south pole), the arctic landscape round the
crater of Gioja, and the large gray plane near Endymion which exceeds in
superficial extent the 'Mare Vaporum'.

[footnote] *Beer and Madler, op. cit., 185, s.208, and § 347, s. 332; and
ix their 'Phys. Kenntniss der himml. Korper', s. 4 und 69, Tab. 1 (Physical
History of the Heavenly Bodies).

Three sevenths of the Moon's surface are entirely p 99 concealed from
our observation, and must always remain so, unless new and unexpected
disturbing causes come into play. These cosmical relations involuntarily
remind us of nearly similar conditions in the intellectual world, where, in
the domain of deep research into the mysteries and the primeval creative
forces of nature, there are regions similarly turned away from us, and
apparently unattainable, of which only a narrow margin has revealed itself,
for thousands of years, to the human mind, appearing, from time to time,
either glimmering in true or delusive light. We have hitherto considered the
primary planets, their satellites, and the concentric rings which belong to
one, at least, of the outermost planets, as products of tangential force, and as
closely connected together by mutual attraction; it therefore now only
remains for us to speak of the unnumbered host of 'comets' which constitute
a portion of the cosmical bodies revolving in independent orbits round the
Sun. If we assume an equable distribution of their orbits, and the limits of
their perihelia, or greatest proximities to the Sun, and the possibility of their
remaining invisible to the inhabitants of the Earth, and base our estimates
on the rules of the calculus of probabilities, we shall obtain as the result an
amount of myriads perfectly astonishing. Kepler, with his usual animation
of expression, said that there were more comets in the regions of space than
fishes in the depths of the ocean. As yet, however, there are scarcely one
hundred and fifty whose paths have been calculated, if we may assume at
six or seven hundred the number of comets whose appearance and passage
through known constellations have been ascertained by more or less precise
observations. While the so-called classical nations of the West, the Greeks
and Romans, although they may occasionally have indicated the position in

which a comet first appeared, never afford any information regarding its
apparent path, the copious literature of the Chinese (who observed nature
carefully, and recorded with accuracy what they saw) contains
circumstantial notices of the constellations through which each comet was
observed to pass. These notices go back to more than five hundred years
before the Christian era, and many of them are still found to be of value in
astronomical observations.*

[footnote] *The first comets of whose orbits we have any knowledge, and
which were calculated from Chinese observations, are those of 240 (under
Gordian II.), 539 (under Justinian), 565, 568, 574, 837, 1337, and 1385. See
John Russell Hind, in Schum., 'Astron. Nachr.', 1843, No. 498. While the
comet of 837 (which, according to Du Sejour, continued during twenty-four
hours within a distance of 2,000,000 miles from the Earth) terrified Louis I.
of France to that degree that he busied himself in building churches and
founding monastic establishments, in the hope of appeasing the evils
threatened by its appearance, the Chinese astronomers made observations
on the path of this cosmical body, whose tail extended over a space of 60
degrees, appearing sometimes single and sometimes multiple. The first
comet that has been calculated solely from European observations was that
of 1456, known as Halley's comet, from the belief long, but erroneously,
entertained that the period when it was first observed by that astronomer
was its first and only well-attested appearance. See Arago, in the 'Annuaire',
1836, p. 204, and Langier, 'Comptes Rendus des Seances de l'Acad.', 1843,
t. xvi., 1006.

p 100 Although comets have a smaller mass than any other cosmical
bodies — being, according to our present knowledge, probably not equal to
1/5000th part of the Earth's mass — yet they occupy the largest space, as
their tails in several instances extend over many millions of miles. The cone

of luminous vapor which radiates from them has been found, in some cases
(as in 1680 and 1811), to equal the length of the Earth's distance from the
Sun, forming a line that intersects both the orbits of Venus and Mercury. It
is even probable that the vapor of the tails of comets mingled with our
atmosphere in the years 1819 and 1823.

Comets exhibit such diversities of form, which appear rather to appertain
to the individual than the class, that a description of one of these
"wandering light-clouds," as they were already called by Xenophanes and
Theon of Alexandria, contemporaries of Pappus, can only be applied with
caution to another. The faintest telescopic comets are generally devoid of
visible tails, and resemble Herschel's nebulous stars. They appear like
circular nebulae of faintly-glimmering vapor, with the light concentrted
toward the middle. This is the most simple type; but it can not, however, be
regarded as rudimentary, since it might equally be the type of an older
cosmical body, exhausted by exhalation. In the larger comets we may
distinguish both the so-called "head" or "nucleus," and the single or
multiple tail, which is characteristically denominated by the Chinese
astronomers "the brush" ('sui'). The nucleus generally presents no definite
outline, although, in a few rare cases, it appears like a star of the first or
second magnitude, and has even been seen in bright sunshine;* as, p 101 for
instance, in the large comets of 1402, 1532, 1577, 1744, and 1843.

[footnote] *Arago, 'Annuaire', 1832, p. 209, 211. The phenomenon of the
tail of a comet being visible in bright sunshine, which is recorded of the
comet of 1402, occurred again in the case of the large comet of 1843, whose
nucleus and tail were seen in North America on the 28th of February
(according to the testimony of J. G. Clarke, of Portland, state of Maine),
between 1 and 3 o'clock in the afternoon.(a) The distance of the very dense
nucleus from the sun's light admitted of being measured with much

exactness. The nucleus and tail appeared like a very pure white cloud, a
darker space intervening between the tail and the nucleus. ('Amer. Journ. of
Science', vol. xiv., No. 1, p. 229.)

[footnote] (a) [The translator was at New Bedford, Massachusetts, U.S.,
on the 28th February, 1843, and distinctly saw the comet, between 1 and 2
in the afternoon. The sky at the time was intensely blue, and the sun shining
with a dazzling brightness unknown in European climates.] — Tr

This latter circumstance indicates, in particular individuals, a denser
mass, capable of reflecting light with greater intensity. Even in Herschel's
large telescope, only two comets, that discovered in Sicily in 1807, and the
splendid one of 1811, exhibited well-defined disks;* the one at an angle of
1 second, and the other at 0.77 seconds, whence the true diameters are
assumed to be 536 and 428 miles.

[footnote] *'Phil. Trans.' for 1808, Part ii., p. 155, and for 1812, Part i., p.
118. The diameters found by Herschel for the nuclei were 538 and 428
English miles. For the magnitudes of the comets of 1798 and 1805, see
Arago, 'Annuaire', 1832, p. 203.

The diameters of the less well-defined nuclei of the comets of 1798 and
1805 did not appear to exceed 24 or 28 miles.

In several comets that have been investigated with great care, especially
in the above-named one of 1811, which continued visible for so long a
period, the nucleus and its nebulous envelope were entirely separated from
the tail by a darker space. The intensity of light in the nucleus of comets
does not augment toward the center in any uniform degree, brightly shining

zones being in many cases separated by concentric nebulous envelopes. The
tails sometimes appear single, sometimes, although more rarely, double;
and in the comets of 1807 and 1843 the branches were of different lengths;
in one instance (1744) the tail had six branches, the whole forming an angle
of 60 degrees. The tails have been sometimes straight, sometimes curved,
either toward both sides, or toward the side appearing to us as the exterior
(as in 1811), or convex toward the direction in which the comet is moving
(as in that of 1618); and sometimes the tail has even appeared like a flame
in motion. The tails are always turned away from the sun, so that their line
of prolongation passes through its center; a fact which, according to Edward
Biot, was noticed by the Chinese astronomers as early as 837, but was first
generally made known in Europe by Fracastoro and Peter Apian in the
sixteenth century. These emanations may be regarded as conoidal envelopes
of greater of less thickness, p 102 and, considered in this manner, they
furnish a simple explanation of many of the remarkable optical phenomena
already spoken of.

Comets are not only characteristically different in form, some being
entirely without a visible tail, while others have a tail of immense length (as
in the instance of the comet of 1618, whose tail measured 104 degrees), but
we also see the same comets undergoing successive and rapidly-changing
processes of configuration. These variations of form have been most
accurately and admirably described in the comet of 1744, by Hensius, at St.
Petersburg, and in Halley's comet, on its last reappearance in 1835, by
Bessel, at Konigsberg. A more or less well-defined tuft of rays emanated
from that part of the nucleus which was turned toward the Sun; and the rays
being bent backward, formed a part of the tail. The nucleus of Halley's
comet; with its emanations, presented the appearance of a burning rocket,
the end of which was turned sideways by the force of the wind. The rays
issuing from the head were seen by Arago and myself, at the Observatory at
Paris, to assume very different forms on successive nights.*

[footnote] *Arago, 'Des Changements physiques de la Comete de Halley
du 15-23 Oct., 1835. 'Annuaire', 1836, p. 218, 221. The ordinary direction
of the emanations was noticed even in Nero's time. "Comae radios solis
effugiunt." — Seneca, 'Nat. Quaest.', vii., 20.

The great Konigsberg astronomer concluded from many measurements,
and from theoretical considerations, "that the cone of light issuing from the
comet deviated considerably both to the right and the left of the true
direction of the Sun, but that it always returned to that direction, and passed
over to the opposite side, so that both the cone of light and the body of the
comet from whence it emanated experienced a rotatory, or, rather, a
vibratory motion in the plane of the orbit." He finds that "the attractive
force exercised by the Sun on heavy bodies is inadequate to explain such
vibrations, and is of opinion that they indicate a polar force, which turns
one semi-diameter of the comet toward the Sun, and strives to turn the
opposite side away from that luminary. The magnetic polarity possessed by
the Earth may present some analogy to this, and, should the Sun have an
opposite polarity, an influence might be manifested, resulting in the
precession of the equinoxes." This is not the place to enter more fully upon
the grounds on which explanations of this subject have been based; but
observations so remarkable,* and views of so exalted p 103 a character,
regarding the most wonderful class of the cosmical bodies belonging to our
solar system, ought not to be entirely passed over in this sketch of a general
picture of nature.

[footnote] *Bessel, in Schumacher, 'Astr. Nachr.', 1836, No. 300-302, s.
188, 192, 197, 200, 202, und 230. Also in Schumacher, 'Jahrb.', 1837, s.
149, 168. William Herschel, in his observations on the beautiful comet of
1811, believed that he had discovered evidences of the rotation of the

nucleus and tail ('Phil. Trans.' for 1812, Part i., p. 140). Dunlop, at
Paramatta thought the same with reference to the third comet of 1825.

Although, as a rule, the tails of comets increase in magnitude and
brilliancy in the vicinity of the sun, and are directed away from that central
body, yet the comet of 1823 offered the remarkable example of two tails,
one of which was turned toward the sun, and the other away from it,
forming with each other an angle of 160 degrees. Modifications of polarity
and the unequal manner of its distribution, and of the direction in which it is
conducted, may in this rare instance have occasioned a double, unchecked,
continuous emanation of nebulous matter.*

[footnote] *Bessel, in 'Astr. Nachr.', 1836, No. 302, s. 231. Schum,
'Jahrb.', 1837 s. 175. See, also Lehmann, 'Ueber Cometenschweife' (On the
Tails of Comets), in Bode, 'Astron. Jahrb. fur' 1826, s. 168.

Aristotle, in his 'Natural Philosophy', makes these emanations the means
of bringing the phenomena of comets into a singular connection with the
existence of the Milky Way. According to his views, the innumerable
quantity of stars which compose this starry zone give out a self-luminous,
incandescent matter. The nebulous belt which separates the different
portions of the vault of heaven was therefore regarded by the Stagirite as a
large comet, the substance of which was incessantly being renewed.*

[footnote] *Aristot., 'Meteor.', i., 8, 11-14, und 19-21 (ed. Ideler, t. i., p.
32-34). Biese, 'Phil. des Aristoteles', bd. ii., s. 86. Since Aristotle exercised
so great an influence throughout the whole of the Middle Ages, it is very
much to be regretted that he was so averse to those grander views of the
elder Pythagoreans, which inculcated ideas so nearly approximating to truth

respecting the structure of the universe. He asserts that comets are transitory
meteors belonging to our atmosphere in the very book in which he cites the
opinion of the Pythagorean school, according to which these cosmical
bodies are supposed to be planets having long periods of revolution.
(Aristot., i., 6, 2.) This Pythagorean doctrine, which, according to the
testimony of Apollonius Myndius, was still more ancient, having originated
with the Chaldeans, passed over to the Romans, who in this instance, as was
their usual practice, were merely the copiers of others. The Myndian
philosopher describes the path of comets as directed toward the upper and
remote regions of heaven. Hence Seneca says, in his 'Nat. Quaest.', vii., 17:
"Cometes non est species falsa, sed proprium sidus sicut solis et lunae:
altiora mundi secat et tunc demum apparet quum in imum cursum sui
venit;" and again (at vii., 27), "Cometes aternos esse et sortis ejusdem, cujus
caetera (sidera), etiamsi faciem illis non habent similem." Pliny (ii., 25) also
refers to Apollonius Myndius, when he says, "Sunt qui et haec sidera
perpetua esse credant suoque ambitu ire, sed non nisi relicta a sole cerni."

p 104 The occulation of the fixed stars by the nucleus of a comet, or by
its innermost vaporous envelopes, might throw some light on the physical
character of these wonderful bodies; but we are unfortunately deficient in
observations by which we may be assured* that the occulation was
perfectly central; for, as it has already been observed, the parts of the
envelope contiguous to the nucleus are alternately composed of layers of
dense or very attenuated vapor.

[footnote] *Olbers, in 'Astr. Nachr.', 1828, s. 157, 184. Arago, 'De la
Constitution physique des Cometes; Annuaire de' 1832, p. 203, 208. The
ancients were struck by the phenomenon that it was possible to see through
comets as through a flame. The earliest evidence to be met with of stars
having been seen through comets is that of Democritus (Aristot., 'Meteor.',

i., 6, 11), and the statement leads Aristotle to make the not unimportant
remark, that he himself had observed the occulation of one of the stars of
Gemini by Jupiter. Seneca only speaks decidedly of the transparence of the
tail of comets. "We may see," says he, "stars through a comet as through a
cloud ('Nat. Quaest.', vii., 18); but we can ony see through the rays of the
tail, and not through the body of the comet itself: 'non in ea parte qua sidus
ipsum est spissi et solidi ignis, sed qua rarus splendor occurrit et in crines
dispergitur. Per intervalla ignium, non er ipsos, vides" (vii., 26). The last
remark is unnecessary, since, as Galileo observed in the 'Saggiatore (Lettera
a Monsignor Cesarini', 1619), we can certainly see through a flame when it
is not of too great a thickness'.

On the other hand the carefully conducted measurements of Bessel prove,
beyond all doubt, that on the 29th of September, 1835, the light of a star of
the tenth magnitude, which was then at a distance of 7".78 from the central
point of the head of Halley's comet, passed through very dense nebulous
matter, without experiencing any deflection during its passage.*

[footnote] *Bessel, in the 'Astron. Nachr.', 1836, No. 301, s. 204, 206.
Struve, in 'Recueil des Mem. de l'Acad. de St. Peterab.', 1836, p. 140, 143,
and 'Astr. Nachr.', 1836, No. 303, s. 238, writes as follows: "At Dorpat the
star was in conjunction only 2".2 from the brightest point of the comet. The
star remained continually visible, and its light was not perceptibly
diminished, while the nucleus of the comet seemed to be almost
extinguished before the radiance of the small star of the ninth or tenth
magnitude."

If such an absence of refracting power must be ascribed to the nucleus of
a comet, we can scarcely regard the matter composing comets as a gaseous

fluid. The question here arises whether this absence of refracting power
may not be owing to the extreme tenuity of the fluid; or does the comet
consist of separated particles, constituting a cosmical stratum of clouds,
which, like the clouds of our atmosphere, that exercise no influence on the p
105 zenith distance of the stars, does not affect the ray of light passing
through it? In the passage of a comet over a star, a more or less considerable
diminution of light has often been observed; but this has been justly
ascribed to the brightness of the ground from which the star seems to stand
forth during the passage of the comet.

The most important and decisive observations that we possess on the
nature and the light of comets are due to Arago's polarization experiments.
His polariscope instructs us regarding the physical constitution of the Sun
and comets, indicating whether a ray that reaches us from a distance of
many millions of miles transmits light directly or by reflection; and if the
former, whther the source of light is a solid, a liquid, or a gaseous body. His
apparatus was used at the Paris Observatory in examining the light of
Capella and that of the great comet of 1819. The latter showed polarized,
and therefore reflected light, while the fixed star, as was to be expected,
appeared to be a self-luminous sun.*

[footnote] *On the 3d of July, 1819, Arago made the first attempt to
analyze the light of comets by polarization, on the evening of the sudden
appearance of the great comet. I was present at the Paris Observatory, and
was fully convinced, as were also Matthieu and the late Bouvard of the
dissimilarity in the intensity of the light seen in the polariscope, when the
instrument received cometary light. When it received light from Capella,
which was near the comet, and at an equal altitude, the images were of
equal intensity. On the reappearance of Halley's comet in 1835, the
instrument was altered so as to give, according to Arago's chromatic

polarization, two images of complementary colors (green and red).
('Annales de Chimie', t. xiii., p. 108; 'Annuaire', 1832, p. 216.) "We must
conclude from these observations," says Arago, "that the cometary light was
not entirely composed of rays having the properties of direct light, there
being light which was reflected specularly or polarized, that is, coming
from the sun. It can not be stated with absolute certainty that comets shine
only with borrowed light, for bodies, in becoming self-luminous, do not, on
that account, lose the power of reflecting foreign light."

The existance of polarized cometary light announced itself not only by
the inequality of the images, but was proved with greater certainty on the
reappearance of Halley's comet, in the year 1835, by the more striking
contrast of the complementary colors, deduced from the laws of chromatic
polarization discovered by Arago in 1811. These beautiful experiments still
leave it undecided whether, in addition to this reflected solar light, comets
may not have light of their own. Even in the case of the planets, as, for
instance, in Venus, an evolution of independent light seems very probable.

The variable intensity of light in comets can not always be p 106
explained by the position of their orbits and their distance from the Sun. It
would seem to indicate, in some individuals, the existence of an inherent
process of condensation, and an increased or diminished capacity of
reflecting borrowed light. In the comet of 1618, and in that which has a
period of three years, it was observed first by Hevelius that the nucleus of
the comet diminished at its perihelion and enlarged at its aphelion, a fact
which, after remaining long unheeded, was again noticed by the talented
astronomer Valz at Nismes. The regularity of the change of volume,
according to the different degrees of distance from the Sun, appears very
striking. The physical explanation of the phenomenon can not, however, be
sought in the condensed layers of cosmical vapor occurring in the vicinity

of the Sun, since it is difficult to imagine the nebulous envelope of the
nucleus of the comet to be vesicular and impervious to the other.*

[footnote] *Arago, in the 'Annuaire', 1832, p. 217-220. Sir John Herschel,
'Astron.', 488.

The dissimilar eccentricity of the orbits of comets has, in recent times
(1819), in the most brilliant manner enriched our knowledge of the solar
system. Encke has discovered the existence of a comet of so short a period
of revolution that it remains entirely within the limits of our planetary
system, attaining its aphelion between the orbits of the smaller planets and
that of Jupiter. Its eccentricity must be assumed at 0.845, that of Juno
(which has the greatest eccentricity of any of the planets) being 0.255.
Encke's comet has several times, although with difficulty, been observed by
the naked eye, as in Europe in 1819, and according to Rumker, in New
Holland in 1822. Its period of revolution is about 3 1/3d years; but, from a
careful comparison of the epochs of its return to its perihelion, the
remarkable fact has been discovered that these periods have diminished in
the most regular manner between the years 1786 and 1838, the diminution
amounting, in the course of 52 years, to about 1 3/10th days. The attempt to
bring into unison the results of observation and calculation in the
investigation of all the planetary disturbances, with the view of explaining
this phenomenon, has led to the adoption of the very probable hypothesis
that there exists dispersed in space a vaporous substance capable of acting
as a resisting medium. This matter diminished the tangential force, and with
it the major axis of the comet's orbit. The value of the constant of the
resistance appears to be somewhat different before and after the perihelion;
and this may, perhaps, be ascribed p 107 to the altered form of the small
nebulous star in the vicinity of the Sun, and to the action of the unequal
density of the strata of cosmical ether.*

[footnote] *Encke, in the 'Astronomiche Nachrichten', 1843, No. 489, s.
130-132.

These facts, and the investigations to which they have led, belong to the
most interesting results of modern astronomy. Encke's comet has been the
means of leading astronomers to a more exact investigation of Jupiter's
mass (a most important point with reference to the calculation of
perturbations); and, more recently, the course of this comet has obtained for
us the first determination, although only an approximative one, of a smaller
mass for Mercury.

The discovery of Encke's comet, which had a period of only 3 1/3d years,
was speedily followed, in 1826, by that of another, Biela's comet, whose
period of revolution is 6 3/4th years, and which is likewise planetary,
having its aphelion beyond the orbit of Jupiter, but within that of Saturn. It
has a fainter light than Encke's comet, and, like the latter, its motion is
direct, while Halley's comet moves in a course opposite to that pursued by
the planets. Biela's comet presents the first certain example of the orbit of a
comet intersecting that of the Earth. This position, with reference to our
planet, may therefore be productive of danger, if we can associate an idea of
danger with so extraordinary a natural phenomenon, whose history presents
no parallel, and the results of which we are consequently unable correctly to
estimate. Small masses endowed with enormous velocity may certainly
exercise a considerable power; but Laplace has shown that the mass of the
comet of 1770 is probably not equal to 1/5000th that of the Earth, or about
1/2000th that of the Moon.*

[footnote] *Laplace, 'Expos. du Syst. du Monde', p. 216, 237.

We must not confound the passage of Biela's comet through the Earth's
orbit with its proximity to, or collision with our globe. When this passage
took place, on the 29th of October, 1832, it required a full month before the
Earth would reach the point of intersection of the two orbits. These two
comets of short periods of revolution also intersect each other, and it has
been justly observed,* that amid the many perturbations experienced by
such small bodies from the largr planets, there is a 'possibility' — supposing
a meeting of these comets to occur in October — that the inhabitants of the
Earth may witness the extraordinary spectacle of an encounter between two
cosmical bodies, and possibly of their reciprocal penetration and
amalgamation, or of their destruction by means of exhausting emanations.

[footnote] *Littrow, 'Beschreibende Astron.', 1835, s. 274. On the inner
comet recently discovered by M. Faye, at the Observatory of Paris, and
whose eccentricity is 0.551, its distance at its perihelion 1.690, and its
distance at its aphelion 5.832, see Schumacher, 'Astron. Nachr.', 1844, No.
495. Regarding the supposed identity of the comet of 1766 with the third
comet of 1819, see 'Astr. Nachr.', 1833, No. 239; and on the identity of the
comet of 1743 and the fourth comet of 1819, see No. 237 or the last
mentioned work.

Events of this nature, resulting either from deflection occasioned by
disturbing masses or primevally intersecting orbits, must have been of
frequent occurrence in the course of millions of years in the immeasurable
regions of ethereal space; but they must be regarded as isolated
occurrences, exercising no more general or alternative effects on cosmical
relations than the breaking forth or extinction of a volcano within the
limited sphere of our Earth.

A third interior comet, having likewise a short period of revolution was
discovered by Faye on the 22d of November, 1843, at the Observatory at
Paris. Its elliptic path, which approaches much more nearly to a circle than
that of any other known comet, is included within the orbits of Mars and
Saturn. This comet, therefore, which, according to Goldschmidt, passes
beyond the orbit of Jupiter, is one of the few whose perihelia are beyond
Mars. Its period of revolution is 7 29/100 years, and it is not improbable
that the form of its present orbit may be owing to its great approximation to
Jupiter at the close of the year 1839.

If we consider the comets in their inclosed elliptic orbits as members of
our solar system, and with respect to the length of their major axes, the
amount of their eccentricity, and their periods of revolution, we shall
probably find that the three planetary comets of Encke, Biela, and Faye are
most nearly approached in these respects, first, by the comet discovered in
1766 by Messier, and which is regarded by Clausen as identical with the
third comet of 1819; and next, by the fourth comet of the last-mentioned
year, discovered by Blaupain, but considered by Clausen as identical with
that of the year 1743, and whose orbit appears, like that of Lexell's comet,
to have suffered great variations from the proximity and attraction of
Jupiter. The two last-named comets would likewise seem to have a period
of revolution not exceeding five or six years, and their aphelia are in the
vicinity of Jupiter's orbit. Among the comets that have a period of
revolution of from seventy to p 109 seventy-six years, the first in point of
importance with respect to theoretical and physical astronomy is Halley's
comet, whose last appearance, in 1835, was much less brilliant than was to
be expected from preceding ones; next we would notice Olbers's comet,
discovered on the 6th of March, 1815; and, lastly, the comet discovered by
Pons in the year 1812, and whose elliptic orbit has been determined by
Encke. The two latter comets were invisible to the naked eye. We now
know with certainty of nine returns of Halley's large comet, it having

recently been proved by Laugier's calculations*, that in the Chinese table of
comets, first made known to us by Edward Biot, the comet of 1378 is
identical with Halley's; its periods of revolution have varied in the interval
between 1378 and 1835 from 74.91 to 77.58 years, the mean being 76.1.

[footnote] *Laugier, in the 'Comptes Rendus des Seances de l'Academie',
1843, t. xvi., p. 1006.

A host of other comets may be contrasted with the cosmical bodies of
which we have spoken, requiring several thousand years to perform their
orbits, which it is difficult to determine with any degree of certainty. The
beautiful comet of 1811 requires, according to Argelander, a period of 3065
years for its revolution, and the colossal one of 1680 as much as 8800 years,
according to Encke's calculation. These bodies respectively recede,
therefore, 21 and 44 times further than Uranus from the Sun, that is to say,
33,600 and 70,400 millions of miles. At this enormous distance the
attractive force of the Sun is still manifested; but while the velocity of the
comet of 1680 at its perihelion is 212 miles in a second, that is, thirteen
times greater than that of the Earth, it scarcely moves ten feet in the second
when at its aphelion. This velocity is only three times greater than that of
water in our most sluggish European rivers, and equal only to half that
which I have observed in the Cassiquiare, a branch of the Orinoco. It is
highly probable that, among the innumerable host of uncalculated or
undiscovered comets, there are many whose major axes greatly exceed that
of the comet of 1680. In order to form some idea by numbers, I do not say
of the sphere of attraction, but of the distance in space of a fixed star, or
other sun, from the aphelion of the comet of 1680 (the furthest receding
cosmical body with which we are acquainted in our solar system), it must
be remembered that, according to the most recent determinations of
parallaxes, the nearest fixed star is full 250 times further removed from our

sun than the comet in its aphelion. The comet's distance is only 44 p 110
times that of Uranus, while 'a' Centauri is 11,000 and 61 Cygni 31,000
times that of Uranus, according to Bessel's determinations.

Having considered the greatest distances of comets from the central body,
it now remains for us to notice instances of the greatest proximity hitherto
measured. Lexell and Burckhardt's comet of 1770, so celebrated on account
of the disturbances it experienced from Jupiter, has approached the Earth
within a smaller distance than any other comet. On the 28th of June, 1770,
its distance from the Earth was ony six times than of the Moon. The same
comet passed twice, viz., in 1769 and 1779, through the system of Jupiter's
four satellites without producing the slightest notable change in the well-
known orbits of these bodies. The great comet of 1680 approached at its
perihelion eight or nine times nearer to the surface of the Sun than Lexell's
comet did to that of our Earth, being on the 17th of December a sixth part of
the Sun's diameter, or seven tenths of the distance of the Moon from that
luminary. Perihelia occurring beyond the orbit of Mars can seldom be
observed by the inhabitants of the Earth, owing to the faintness of the light
of distant comets; and among those already calculated the comet of 1729 is
the only one which has its perihelion between the orbits of Pallas and
Jupiter; it was even observed beyond the latter.

Since scientific knowledge, although frequently blended with vague and
superficial views, has been more extensively diffused through wider circles
of social life, apprehensions of the possible evils threatened by comets have
acquired more weight as their direction has become more definite. The
certainty that there are within the known planetary orbits comets which
revisit our regions of space at short intervals — that great disturbances have
been produced by Jupiter and Saturn in their orbits, by which such as were
apparently harmless have been converted into dangerous bodies — the
intersection of the Earth's orbit by Biela's comet — the cosmical vapor,

which, acting as a resisting and impeding medium, tends to contract all
orbits — the individual difference of comets, which would seem to indicate
considerable decreasing gradations in the quantity of the mass of the
nucleus, are all considerations more than equivalent, both as to number and
variety, to the vague fears entertained in early ages of the general
conflagration of the world by 'flaming swords', and stars with 'fiery
streaming hair'. As the consolatory considerations which may be derived
from the calculus of probabilities address themselves to reason and to p 111
meditative understanding only, and not to the imagination or to a
desponding condition of mind, modern science has been accused, and not
entirely without reason, of not attempting to allay apprehensions which it
has been the very means of exciting. It is an inherent attribute of the human
mind to experience fear, and not hope or joy, at the aspect of that which is
unexpected and extraordinary.*

[footnote] *Fries, 'Vorlesungen uber die Sternkunde', 1833, s. 262-267
(Lectures on the Science of Astronomy). An infelicitously chosen instance
of the good omen of a comet may be found in Seneca, 'Nat. Quest.', vii., 17
and 21. The philosopher thus writes of the comet: "Quem nos Neronis
principatu latissimo vidimus et qui cometis detraxit infamiam."

The strange form of a large comet, its faint nebulous light, and its sudden
appearance in the vault of heaven, have in all regions been almost
invariably regarded by the people at large as some new and formidable
agent inimical to the existing state of things. The sudden occurrence and
short duration of the phenomenon lead to the belief of some equally rapid
reflection of its agency in terrestrial matters, whose varied nature renders it
easy to find events that may be regarded as the fulfillment of the evil
foretold by the appearance of these mysterious cosmical bodies. In our own
day, however, the public mind has taken another and more cheerful,

although singular, turn with regard to comets; and in the German vineyards
in the beautiful valleys of the Rhine and Moselle, a belief has arisen,
ascribing to these once ill-omened bodies a beneficial influence on the
ripening of the vine. The evidence yielded by experience, of which there is
no lack in these days, when comets may so frequently be observed, has not
been able to shake the common belief in the meteorological myth of the
existence of wandering stars capable of radiating heat.

This material taken from pages 111- 147

COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1
by Alexander von Humboldt

Translated by E C Otte

from the 1858 Harper & Brothers edition of Cosmos, volume 1
—————————————————————————

From comets I would pass to the consideration of a far more enigmatical
class of agglomerated matter — the smallest of all asteroids, to which we
apply the name 'aërolites', or 'meteoric stones',* when they reach our
atmosphere in a fragmentary condition.

[footnote] * (Much valuable information may be obtained regarding the
origin and composition of aërolites or meteoric stones in Memoirs on the
subject, by Baumbeer and other writers, in the numbers of Poggendorf's
'Annalen', from 1845 to the present time.) — Tr.

If I should seem to dwell on the specific enumeration of these bodies, and
of comets, longer than the general nature of this work might warrant, I have
not done so undesignedly. The diversity existing in the individual

characteristics of comets has already been noticed. The imperfect
knowledge we possess of their physical character renders it p 112 diifficult
in a work like the present, to give the proper degree of circumstantiality to
the phenomena, which, although of frequent recurrence, have been
observed with such various degrees of accuracy, or to separate the necessary
from the accidental. It is only with respect to measurements and
computations that the astronomy of comets has made any marked
advancement, and, consequently, a scientific consideration of these bodies
must be limited to a specification of the differences of physiognomy and
conformation in the nucleus and tail, the instances of great approximation to
other cosmical bodies, and of the extremes in the length of their orbits and
in their periods of revolution. A faithful delineation of these phenomena, as
well as of those which we proceed to consider, can only be given by
sketching individual features with the animated circumstantiality of reality.

Shooting stars, fire-balls, and meteoric stones are, with great probability,
regarded as small bodies moving with planetary velocity, and revolving in
obedience to the laws of general gravity in conic sections round the Sun.
When these masses meet the Earth in their course, and are attracted by it,
they enter within the limits of our atmosphere in a luminous condition, and
frequently let fall more or less strongly heated stony fragments, covered
with a shining black crust. When we enter into a careful investigation of the
facts observed at those epochs when showers of shooting stars fell
periodically in Cumana in 1799, and in North America during the years
1833 and 1834, we shall find that 'fire-balls' can not be considered
separately from shooting stars. Both these phenomena are frequently not
only simultaneous and blended together, but they likewise are often found
to merge into one another, the one phenomenon gradually assuming the
character of the other alike with respect to the size of their disks, the
emanation of sparks, and the velocities of their motion. Although exploding
smoking luminous fire-balls are sometimes seen, even in the brightness of

tropical daylight,* equaling in size the apparent p 113 diameter of the
Moon, innumerable quantities of shooting stars have, on the other hand,
been observed to fall in forms of such extremely small dimensions that they
appear only as moving points or 'phosphorescent lines.'**

[footnote] *A friend of mine, much accustomed to exact trigonometrical
measurements, was in the year 1788 at Popayan, a city which is 2 degrees
26' north latitude, lying at an elevation of 5583 feet above the level of the
sea, and at noon, when the sun was shining brightly in a cloudless sky, saw
his room lighted up by a fire-ball. He had his back to the window at the
time, and on turning round, perceived that great part of the path traversed
by the fire-ball was still illuminated by the brightest radiance. Different
nations have had the most various terms to express these phenomena: The
Germans use the word 'Sternschnuppe', literally 'star snuff' — an expression
well suited to the physical views of the vulgar in former times, according to
which, the lights in the firmament were said to undergo a process of
'snuffing' or cleaning; and other nations generally adopt a term expressive
of a 'shot' or 'fall' of stars, as the Swedish 'stjernifall', the Italian 'stella
cadente', and the English 'star shoot.' In the woody district of the Orinoco,
on the dreary banks of the Cassiquiare, I heard the natives in the Mission of
Vasiva use terms still more inelegant than the German 'star snuff.' ('Relation
Historique du Voy. aux Régions Equinox.', t. ii., p. 513.) These same tribes
term the pearly drops of dew which cover the beautiful leaves of the
heliconia 'star spit.' In the Lithuanian mythology, the imagination of the
people has embodied its ideas of the nature and signification of falling stars
under nobler and more graceful symbols. The Parcæ, 'Werpeja', weave in
heaven for the new-born child its thread of fate, attaching each separate
thread to a star. When death approaches the person, the thread is rent, and
the star wanes and sinks to the earth. Jacob Grimm, 'Deutsche Mythologie',
1843, s. 685.

[footnote] ** According to the testimony of Professor Denison Olmsted,
of Yale College, New Haven, Connecticut. (See Poggend., 'Annalen der
Physik', bd. xxx., s. 194.) Kepler, who excluded fire-balls and shooting stars
from the domain of astronomy, because they were, according to his views,
"meteors arising from the exhalations of the earth, and blending with the
higher ether," expresses himself, however, generally with much caution. He
says: "Stellæ cadentes sunt materia viscida inflammata. Earum aliquæ inter
cadendum absumuntur, aliquæ verè in terram cadunt, pondere suo tractæ.
Nec est dissimile vero, quasdam conglobatas esse ex materia fæculentâ, in
ipsam auram ætheream immixta: exque aëtheris regione, tractu rectilineo,
per aërem trajicere, ceu minutos competas, occultâ causa motus
utrorumque." — Kepler, 'Epit. Astron. Copernicanæ', t. i., p. 80.

It still remains undertermined whether the many luminous bodies that
shoot across the sky may not vary in their nature. On my return from the
equinoctial zones, I was impressed with an idea that in the torrid regions of
the tropics I had more frequently than in our colder latitudes seen shooting
stars fall as if from a height of twelve or fifteen thousand feet; that they
were of brighter colors, and left a more brilliant line of light in their track;
but this impression was no doubt owing to the greater transparency of the
tropical atmosphere*, which enables the eye to penetrate further into
distance.

[footnote] *'Relation Historique', t. i., p. 80, 213, 527. If in falling stars,
as in comets, we distinguish between the head or nucleus and the tail, we
shall find that the greater transparency of the atmosphere in tropical
climates is evinced in the greater length and brilliancy of the tail which may
be observed in those latitudes. The phenomenon is therefore not necessarily
more frequent there, because it is oftener seen and continues longer visible.

The influence exercised on shooting stars by the character of the
atmosphere is shown occasionally even in our temperate zone, and at very
small distances apart. Wartmann relates that on the occasion of a November
phenomenon at two places lying very near each other, Geneva and Aux
Planchettes, the number of the meteors counted were as 1 to 7. (Wartmann,
'Mém. sur les Etoiles filantes', p. 17.) The tail of a shooting star (or its
'train'), on the subject of which Brandes has made so many exact and
delicate observations, is in no way to be ascribed to the continuance of the
impression produced by light on the retina. It sometimes continues visible a
whole minute, and in some rare instances longer than the light of the
nucleus of the shooting star; in which case the luminous track remains
motionless. (Gilb., 'Ann.', bd. xiv., s. 251.) This circumstance further
indicates the analogy between large shooting stars and fire-balls. Admiral
Krusenstern saw, in his voyage round the world, the train of a fire-ball shine
for an hour after the lluminous body itself had disappeared, and scarcely
move throughout the whole time. ('Reise', th. i., s. 58.) Sir Alexander
Burnes gives a charming description of the transparency of the clear
atmosphere of Bokhara, which was once so favorable to the pursuit of
astronomical observations. Bokhara is situated in 39 degrees 48' north
latitude, and at an elevation of 1280 feet above the level of the sea. "There
is a constant serenity in its atmosphere, and an admirable clearness in the
sky. At night, the stars have uncommon luster, and the Milky Way shines
gloriously in the firmament. There is also a never-ceasing display of the
most brilliant meteors, which dart like rockets in the sky; ten or twelve of
them are sometimes seen in an hour, assuming every color — fiery red,
blue, pale, and faint. It is a noble country for astronomical science, and
great must have been the advantage enjoyed by the famed observatory of
Samarkand." (Burnes, 'Travels into Bokhara', vol. ii. (1834), p. 158.) A mere
traveler must not be reproached for calling ten or twelve shooting stars in an
hour "many," since it is only recently that we have learned, from careful

observations on this subject in Europe, that eight is the mean number which
may be seen in an hour in the field of vision of one individual (Quetelet,
'Corresp. Mathém.', Novem., 1837, p. 447); this number is, however,
limited to five or six by that diligent observer, Olbers. (Schum., 'Jahrb.',
1838, s. 325.)

p 114 Sir Alexander Burnes likewise extols as a consequence of the
purity of the atmosphere in Bokhara the enchanting and constantly-
recurring spectacle of variously-colored shooting stars.

The connection of meteoric stones with the grander phenomenon of fire-
balls — the former being known to be projected from the latter with such
force as to penetrate from ten to fifteen feet into the earth — has been
proved, among many other instances, in the falls of azzzuerolites at
Barbotan, in the Department des Landes (24th July, 1790), at Siena (16th
June, 1794), at Weston, in Connecticut, U. S. (14th December, 1807), and at
Juvenas in the Department of Ardèche (14th June, 1821). Meteoric stones
are in some instances thrown from dark clouds suddenly formed in a clear
sky, and fall with a noise resembling thunder. Whole districts have thus
occasionally been covered with thousands of fragmentary masses, of
uniform character but unequal magnitudes, that p 115 have been hurled
from one of these moving clouds. In less frequent cases, as in that which
occurred on the 16th of September, 1843, at Kleinwenden, near
Mühilhausen, a large aërolite fell with a thundering crash while the sky was
clear and cloudless. The intimate affinity between fire-balls and shooting
stars is further proved by the fact that fire-balls, from which meteoric stones
have been thrown have occasionally been found, as at Angers, on the 9th of
June, 1822, having a diameter scarcely equal to that of the small fire-works
called Roman candles.

The formative power, and the nature of the physical and chemical
processes involved in these phenomena are questions all equally shrouded
in mystery, and we are as yet ignorant whether the particles composing the
dense mass of meteoric stones are originally, as in comets, separated from
one another when they become luminous to our sight, or whether in the case
of smaller shooting stars, any compace substance actually falls, or, finally,
whether a meteor is composed only of a smoke-like dust, containing iron
and nickel; while we are wholly ignorant of what takes place within the
dark cloud from which a noise like thunder is often heard for many minutes
before the stones fall.*

[footnote] *On 'méteoric dust', see Arago, in the 'Annuaire' for 1832, p.
254. I haave very recently endeavored to show, in another work ('Asie
Centrale', t. i., p. 408). how the Scythian saga of the sacred gold, which fell
burning from heaven, and remained in the possession of the Golden Horde
of the Paralatæ (Herod., iv., 5-7), probably originated in the vague
recollection of the fall of an aërolite. The ancients had also some strange
fictions (Dio Cassius, lxxv., 1259) or silver which had fallen from heaven,
and with which it had been attempted, under the Emperor Severus, to cover
bronze coins; metallic iron was however, known to exist in meteoric stones.
(Plin., ii., 56.) The frequently-recurring expression 'lapidibus pluit' must not
always be understood to refer to falls of aërolites. In Liv., xxv., 7, it
probably refers to pumice ('rapilli') ejected from the volcano, Mount
Albanus (Monte Cavo), which was not wholly extinguished at the time.
(See Heyne, 'Opuscula Acad.', t. iii., p. 261; and my 'Relation Hist.', t. i., p.
394.) The contest of Hercules with the Ligyans, on the road from the
Caucasus to the Hesperides, belongs to a different sphere of ideas, being an
attempt to explain mythically the origin of the round quartz blocks in the
Ligyan field of stones at the mouth of the Rhone, which Aristotle supposes
to have been ejected from a fissure during an earthquake, and Posidonius to

have been caused by the force of the waves of an inland piece of water. In
the fragments that we still possess of the play of Æschylus, the 'Prometheus
Delivered', every thing proceeds, however, in part of the narration, as in a
fall of aërolites, for Jupiter draws together a cloud, and causes the "district
around to be covered by a shower of round stones". Posidonius even
ventured to deride the geognostic myth of the blocks and stones. The
Lygian field of stones was, however, very naturally and well described by
the ancients. The district is now known as 'La Crau.' (See Guerin, 'Mesures
Barométriques dans les Alpes, et Météorologie d'Avignon', 1829, chap. xii.,
p. 115.)

p 116 We can ascertain by measurement the enormous, wonderful, and
wholly planetary velocity of shooting stars, fire-valls and meteoric stones,
and we can gain a knowledge of what is the general and uniform character
of the phenomenon, but not of the genetically cosmical process and the
results of the metamorphoses. If meteoric stones while revolving in space
are already consolidated into dense masses,* less dense, however, p 117
than the mean density of the earth, they must be very small nuclei, which
surrounded by inflammable vapor or gas, form the innermost part of fire-
balls, from the height and apparent diameter of which we may, in the case
of the largest, estimate that the actual diameter varies from 500 to about
2800 feet.

[footnote] *The specific weight of aërolites varies from 1.9 (Alais) to 4.3
(Tabor). Their general density may be set down as 3, water being 1. As to
what has been said in the text of the actual diameters of fire-balls, we must
remark, that the numbers have been taken from the few measurements that
can be relied upon as correct. These give for the fire-ball of Weston,
Connecticut (14th December, 1807), only 500; for that observed by Le Roi
(10th July, 1771) about 1000 and for that estimated by Sir Charles Blagden

(18th January, 1783) 2600 feet in diameter. Brandes ('Unterhaltungen' bd.i.,
s. 42) ascribes a diameter varying from 80 to 120 feet to shooting stars, and
a luminous train extending from 12 to 16 miles. There are, however, ample
optical causes for supposing that the apparent diameter of fire-balls and
shooting stars has been very much overrated. The volume of the largest fire-
ball yet observed can not be compared with that of Ceres, estimating
generally so exact and admirable treatise, 'On the Connection of the
Physical Sciences', 1835, p. 411.) With the view of elucidating what has
been stated in the text regarding the large zërolite that fell into the bed of
the River Narni, but has not again been found, I will give the passage made
known by Pertz, from the 'Chronicon Benedicti, Monachi Sancti Andreæ in
Mont Soracte', a MS. belonging to the tenth century, and preserved in the
Chigi Library at Rome. The Barbarous Latin of that age has been left
unchanged. "Anno 921, temporibus domini Johannis Decimi pape, in anno
pontificatus illius 7 visa sunt signa. Nam juxta urben Romam lapides
plurimi de cælo cadere visi sunt. In civilate quæ vocatur Narnia tam diri ac
tetri, ut nihil aliud credatur, quam de infernalibus locis deducti essent. Nam
ita ex illis lapidibus unus omnium maximum est, ut decidens in flumen
Narnus, ad mensuram unius cubiti super aquas fluminus usque hodie
videretur. Nam et ignitæita ut pene terra contingeret. AliAnno 921,
temporibus domini Johannis Decimi pape, in anno pontificatus illius 7 visa
sunt signa. Nam juxta urben Romam lapides plurimi de cælo cadere visi
sunt. In civilate quæ vocatur Narnia tam diri ac tetri, ut nihil aliud credatur,
quam de infernalibus locis deducti essent. Nam ita ex illis lapidibus unus
omnium maximum est, ut decidens in flumen Narnus, ad mensuram unius
cubiti super aquas fluminus usque hodie videretur. Nam et ignitæ ita ut pene
terra contingeret. Ali cadentes," etc. (Pertz, 'Monum. Germ. Hist.
Scriptores', t. iii., p. 715.) On the aërolites of gos Potamus, which fell,
according to the Parian Chroniccle, in the 78 1 Olympiad, see Böckh, 'Corp.
Inscr. Graec', t. ii., p. 302, 320, 340; also Aristot., 'Meteor.', i., 7 (Ideler's

'Comm.', t. i., p. 404-407); Stob., 'Eel. Phys.', i., 25, p. 508 (Heeren); Plut.,
'Lys.', c. 12; Diog. Laert., ii., 10; and see, also, subsequent notes in this
work. According to a Mongolisn tradition, a black fragment of a rock, forty
feet in height, fell from heaven on a plain near the source of the Great
Yellow River in Western China. (Abel Rémusat, in Lamétherie, 'Jour. de
Phys.', 1819, Mai p. 264.)

The largest meteoric masses as yet known are those of Otumpa, in Chaco,
and of Bahia, in Brazil, described by Rubi de Celis as being from 7 to 7 1/2
feet in length. The meteoric stone of gos Potamos, celebrated in antiquity,
and even mentioned in the Chronicle of the Parian Marbles, which fell
about the year in which Socrates was born, has been described as of the size
of two mill-stones, and equal in weight to a full wagon load.
Notwithstanding the failure that has attended the efforts of the African
traveler, Brown, I do not wholly relinquish the hope that, even after the
lapse of 2312 years, this Thracian meteoric mass, which it would be so
difficult to destroy, may be found, since the region in which it fell is now
bcome so easy of access to European travelers. The huge aërolite which in
the beginning of the tenth century fell into the river at Narni, projected
between three and four feet above the surface of the water, as we learn from
a document lately discovered by Pertz. It must be remarked that these
meteoric bodies, whether in ancient or modern times can only be regarded
as the principal fragments of masses that have been broken up by the
explosion either of a fire-ball of a dark cloud.

On considering the enormous velocity with which, as has been
mathematically proved, meteoric stones reach the earth from the extremest
confines of the atmosphere, and the lengthened course traversed by fire-
balls through the denser strata of the air, it seems more than improbable that
these metalliferous stony masses, containing perfectly-formed crystals of

olivine, labradorite, and pyroxene, should in so short a period of time has
been converted from a vaporous condition to a solid nucleus. Moreover, that
which falls from meteoric masses, even where the internal composition is
chemically different, exhibits almost always the peculiar character of a
fragment, being of a prismatic or truncated pyramidal form, with broad,
somewhat curved faces, and rounded angles. But whence comes this form,
which was first recognized by Schreiber as characteristic of the 'severed'
part of a rotating planetary body? Here, as in the sphere of organic life, all
that appertains to the history of development remains hidden in obscurity.
Meteoric masses become luminous and kindle at heights which p 118 must
be regarded as almost devoid of air, of occupied by an atmosphere that does
not even contain 1/100000th part of oxygen. The recent investigations of
Biot on the important phenomenon of twilight* have considerably lowered
the lines which had, perhaps with some degree of temerity, been usually
termed the boundaries of the atmosphere; but processes of light may be
evolved independently of the presence of oxygen, and Poisson conjectured
that aëroliteswere ignited far beyond the range of our atmosphere.
Numerical calculation and geometrical measurement are the only means by
which as in the case of the larger bodies of our solar system, we are enabled
to impart a firm and safe basis to our investigations of meteoric stones.

[footnote] *Biot, 'Traité d'Astronomie Physique' (3ème éd.), 1841, t. i., p.
149, 177, 238, 312. My lamented friend Poisson endeavored, in a singular
manner, to solve the difficulty attending an assumption of the spontaneous
ignition of meteoric stones at an elevation where the density of the
atmosphere is almost null. These are his words: "It is difficult to attribute,
as is uaually done, the incandescence of aërolites to friction against the
molecules of the atmosphere at an elevation above the earth where the
density of the air is almost null. May we not suppose that the electric fluid,
in a neutral condition, forms a kind of atmosphere, extending far beyond the

mass of our atmosphere, yet subject to terrestrial attraction, although
physically imponderable, and consequently following our globe in its
motion? According to this hypothesis, the bodies of which we have been
speaking would, on entering this imponderable atmosphere, decompose the
neutral fluid by their unequal action on the two electricities, and they would
thus be heated, and in a state of incandescence, by becoming electrified."
(Poisson, 'Rech. sur la Probabilité des Jugements', 1837, p. 6.)

Although Halley pronounced the great fire-ball of 1686, whose motion
was opposite to that of the earth in its orbit,* to be a cosmical body, Chadni,
in 1794, first recognized, with ready acuteness of mind, the connection
between fire-balls and the stones projected from the atmosphere, and the
motions of the former bodies in space.**

[footnote] *'Philos. Transact.', vol. xxix., p. 161-163.

[footnote] **The first edition of Chlandni's important treatise, 'Ueber den
Ursprung der von Pallas gefundenen und anderen Eisenmassen' (On the
Origin of the masses of Iron found by Pallas, and other similar masses),
appeared two months prior to the shower of stones at Siena, and two years
before Lichtenberg stated, in the 'Güttingen Taschenbuch', that "stones
reach our atmosphere from the remoter regions of space.' Comp., also,
Olbers's letter to Benzenberg, 18th Nov., 1837, in Benzenberg's 'Treatise on
Shooting Stars', p. 186.

A brilliant confirmation of the cosmical origin of these phenomena has
been afforded by Denison Olmsted, at New Haven, Connecticut, who has
shown on the concurrent authority of all eye-witnesses, that during the
celebrated fall of shooting stars on the night between the 12th p 119 and

13th of November, 1833, the fire-balls and shooting stars all emerged from
one and the same quarter of the heavens, namely, in the vicinity of the star
'gamma' in the constellation Leo, and did not deviate from this point,
although the star changed its apparent height and azimuth during the time of
the observation. Such an independence of the Earth's rotation shows that the
luminous body must have reached our atmosphere from 'without.'
According to Encke's computation* of the whole p 120 number of
observations made in the United States of North America, between the
thirty-fifth and the forty-second degrees of latitude, it would appear that all
these meteors came from the same point of space in the direction in which
the Earth was moving at the time.

[footnote] *Encke, in Poggend., 'Annalen', bd. xxxiii. (1834), s. 213.
Arago, in the 'Annuaire' for 1836, p. 291. Two letters which I wrote to
Benzenberg, May 19 and October 22, 1837, on the conjectural precession of
the nodes in the orbit of periodical falls of shooting stars. (Benzenberg's
'Sternsch.', s. 207 and 209.) Olbers subsequently adopted this opinion of the
gradual retardation of the November phenomenon. ('Astron. Nachr.', 1838,
No. 372, s. 180.) If I may venture to combine two of the falls of shooting
stars mentioned by the Arabian writers with the epochs found by
Boguslawski for the fourteenth century, I obtain the following more or less
accordant elements of the movements of the nodes: In Oct., 902, on the
night in which King Ibrahim ben Ahmed died, there fell a heavy shower of
shooting stars, "like a fiery rain;" and this year was, therefore, called the
year of stars. (Conde, 'Hist. de la Domin.' de los Arabes', p. 346.) On the
19th of Oct., 1202, the stars were in motion all night. "They fell like
locusts." ('Comptes Rendus', 1837, t. i., p. 294; and Fræhn, in the 'Bull. de
l'Académie de St. Pétersbourg', t. iii., p. 308.) On the 21st Oct., O.S., 1366,
"'die sequente post festum XI. millia Virginum ab hora matutina usque ad
horam primam visæ sunt quasi stellæ de cælo cadere continuo, et in tanta

multitudine, quod nemo narrare suf ficit.'" This remarkable notice, of which
we shall speak more fully in the subsequent part of this work, was found by
the younger Von Boguslawski, in Benesse (de Horowic) de Weitmil or
Weithmül, 'Chronicon Ecclesiæ Pragensis', p. 389. This chronicle may also
be found in the second part of 'Scriptores rerum Bohemicarum', by Pelzel
and Dobrowsky, 1784. (Schum., 'Astr. Nachr.', Dec., 1839.) On the night
between the 9th and 10th of November, 1787, many falling stars were
observed at Manheim, Southern Germany, by Hemmer (Kämtz, 'Meteor.',
th. iii., s. 237.) After midnight, on the 12th of November, 1799, occurred the
extraordinary fall of stars at Cumana, which Bonpland and myself have
described, and which was observed over a great part of the earth. ('Relat.
Hist.', t. i., p. 519-527.) Between the 12th and 13th of November, 1822,
shooting stars, intermingled with fire-balls, were seen in large numbers by
Kloden, at Potsdam. (Gilbert's 'Ann.', bd. lxxii., s. 291.) On the 13th of
November, 1831, at 4 o'clock in the morning, a great shower of falling stars
was seen by Captain Bérard, on the Spanish coast, near Carthagena del
Levante. ('Annuaire', 1836, p. 297.) In the night between the 12th and 13th
of November, 1833, occurred the phenomenon so admirably described by
Professor Olmsted, in North America. In the night of the 13-14th of
November, 1834, a similar fall of shooting stars was seen in North America,
although the numbers were not quite so considerable. (Poggend., 'Annalen',
bd. xxxiv., s. 129.) On the 13th of November, 1835, a barn was set on fire
by the fall of a sporadic fire-ball, at Belley, in the Department de l'Ain.
('Annuaire', 1836, p. 296.) In the year 1838, the stream showed itself most
decidedly on the night of the 13-14th of November. ('Astron. Nachr.', 1838,
No. 372.)

On the recurrence of falls of shooting stars in North America, in the
month of November of the years 1834 and 1837, and in the analogous falls
observed at Bremen in 1838, a like general parallelism of the orbits, and the

same direction of the meteors from the constellation Leo, were again
noticed. It has been supposed that a greater parallelism was observable in
the direction of periodic falls of shooting stars than in those of sporadic
occurrence; and it has further been remarked, that in the periodically-
recurring falls in the month of August, as, for instance, in the year 1839, the
meteors came principally from one point between Perseus and Taurus,
toward the latter of which constellations in the Earth was then moving. This
peculiarity of the phenomenon, manifested in the retrograde direction of the
orbits in November and August, should be thoroughly investigated by
accurate observations, in order that it may either be fully confirmed or
refuted.

The heights of shooting stars, that is to say, the heights of the points at
which they begin and cease to be visible, vary exceedingly, fluctuating
between 16 and 140 miles. This important result, and the enormous velocity
of these problematical asteroids, were first ascertained by Benzenberg and
Brandes, by simultaneous observations and determinations of parallax at the
extremities of a base line of 49,020 feet in length.*

[footnote] *I am well aware that, among the 62 shooting stars
simultaneously observed in Silesia, in 1823, at the suggestion of Professor
Brandes some appeared to have an elevation of 183 to 240, or even 400
miles. (Brandes, 'Unterhaltungen für Freunde der Astronomie und Physik',
heft i., s. 48. Instructive Narratives for the Lovers of Astronomy and
Physics.) But Olbers considered that all determinations for elevations
beyond 120 miles must be doubtful, owing to the smallness of the parallax.

The relative velocity of motion is from 18 to 36 miles in a second, and
consequently equal to planetary velocity. This planetary velocity,* as well
as the direction of the orbits p 121 of fire-balls and shooting stars, which

has frequently been observed to be opposite to that of the Earth, may be
considered as conclusive arguments against the hypothesis that aërolites
derive their origin from the so-called active 'lunar volcanoes.'

[footnote] *The planetary velocity of translation, the movement in the
orbit, is in Mercury 26.4, in Venus 19.2, and in the Earth 16.4 miles in a
second.

Numerical views regarding a greater or lesser volcanic force on a small
cosmical body, not surrounded by any atmosphere, must, from their nature,
be wholly arbitrary. We may imagine the reaction of the interior of a planet
on its crust ten or even a hundred times greater than that of our present
terrestrial volcanoes; the direction of masses projected from a satellite
revolving from west to east might appear retrogressive, owing to the Earth
in its orbit subsequently reaching that point of space at which these bodies
fall. If we examine the whole sphere of relations which I have touched upon
in this work, in order to escape the charge of having made unproved
assertions, we shall find that the hypothesis of the selenic origin of meteoric
stones* depends upon a number of conditions p 122 whose accidental
coincidence could alone convert a possible into an actual fact.

[footnote] *Chladni states that an Italian physicist, Paolo Maria Terzago,
on the occasion of the fall of an aërolite at Milan in 1660, by which a
Franciscan monk was killed, was the first who surmised that aërolites were
of selenic origin. He says, in a memoir entitled 'Musæum Septalianum,
Manfredi Septalæ, Patricii Mediolanensis, industrioso labore constructum'
(Tortona, 1664, p. 44), "Labant philosophorum mentes sub horum lapidum
ponderibus; ni dicire velimus, lunan terram alteram, sine mundum esse, ex
cujus montibus divisa frustra in inferiorem nostrum hunc orben dela

bantur." Without any previous knowledge of this conjecture, Olbers was
led, in the year 1795 (after the celebrated fall at Siena on the 16th of June,
1794), into an investigation of the amount of the initial tangential force that
would be requisite to bring to the Earth masses projected from the Moon.
This ballistic problem occupied, during ten or twelve years, the attention of
the geometricians Laplace, Biot, Brandes, and Poisson. The opinion which
was then so prevalent, but which has since been abandoned, of the existence
of active volcanoes in the Moon, where air and water are absent, led to a
confusion in the minds of the generality of persons between mathematical
possibilities and physical probabilities. Olbers, Brandes, and Chladni
thought "that the velocity of 16 to 32 miles, with which fire-balls and
shooting stars entered our atmosphere," furnished a refutation to the view of
their selenic origin. According to Olbers, it would require to reach the
Earth, setting aside the resistance of the air, an initial velocity of 8292 feet
in the second; according to Laplace, 7862; to Biot, 8282; and to Poisson,
7595. Laplace states that this velocity is only five or six times as great as
that of a cannon ball; but Olbers has shown "that, with such an initial
velocity as 7500 or 8000 feet in a second, meteoric stones would arrive at
the surface of our earth with a velocity of only 35,000 feet (or 1.53 German
geographical mile). But the measured velocity of meteoric stones averages
five such miles, or upward of 114,000 feet to a second; and, consequently,
the original velocity of projection from the Moon must be almost 110,000
feet, and therefore fourteen times greater than Laplace asserted." (Olbers, in
Schum, 'Jahrb.', 1837, p. 52-58; and in Gehler, 'Neues Physik.'
'Wörterbuche', bd. vi., abth.3, s. 2199-2136.) If we could assume volcanic
forces to be still active on the Moon's surface, the absence of atmospheric
resistance would certainly give to their projectile force an advantage over
that of our terrestrial volcanoes; but even in respect to the measure of the
latter force (the projectile force of our own volcanoes), we have no
observations on which any reliance can be placed, and it has probably been

exceedingly overrated. Dr. Peters, who accurately observed and measured
the phenomena presented by Ætna, found that the greatest velocity of any of
the stones projected from the crater was only 1250 feet to a second.
Observations on the Peak of Teneriffe, in 1798, gave 3000 feet. Although
Laplace, at the end of his work ('Expos. du Syst. du Monde', ed. de 1824, p.
399), cautiously observes, regarding aërolites, "that in all probability they
come from the depths of space," yet we see from another passage (chap. vi.,
p. 233) 6that, being probably unacquainted with the extraordinary planetary
velocity of meteoric stones, he inclines to the hypothesis of their lunar
origin, always, however, assuming that the stones projjected from the Moon
"become satellites of our Earth, describing around it more or less eccentric
orbits, and thus not reaching its atmosphere until several or even many
revolutions have been accomplished." As an Italian at Tortona had the fancy
that aërolites came from the Moon, so some of the Greek philosophers
thought they came from the Sun. This was the opinion of Diogenes Laertius
(ii., 9) regarding the origin of the mass that fell at "gos Potamos (see note,
p. 116). Pliny, whose labors in recording the opinions and statements of
preceding writers are astonishing, repeats the theory, and derides it the more
freely, because he, with earlier writers (Diog. Laert., 3 and 5, p. 99,
Hübner), accuses Anaxagoras of having predicted the fall of aërolites from
the Sun: "Celebrant Græci Anaxagoram Clazomenium Olympiadis
septuagesimæ octavæ secundo anno prædixisse cælestium litterarum
scientia quibus diebus saxum casurum esse e sole, idque factum interdia in
Thraciæ parte ad gos flumen. Quod si quis prædictum credat, simul fateatur
necesse est, majoris miraculi divinitatem Anaxagoræ fuisse, solvique rerum
naturæ intellectum, et confundi omnia, si aut ipse Sol lapis esse aut unquam
lapidem in eo fuisse credatur; decidere tamen crebro non erit dubium." The
fall of a moderate-sized stone, which is preserved in the Gymnasium at
Abydos, is also reported to have been foretold by Anaxagoras. The fall of
aërolites in bright sunshine, and when the Moon's disk was invisible,

probably led to the idea of sun-stones. Moreover, according to one of the
physical dogmas of Anaxagoras, which brought on him the persecution of
the theologians (even as they have attacked the geologists of our own
times), the Sun was regarded as "a molten fiery mass" ([Greed words]). In
accordance with these views of Anaxagoras, we find Euripides, in 'Phaëton',
terming the Sun "a golden mass;" that is to say, a fire-colored, brightly-
shining matter, but not leading to the inference that aërolites are golden sun-
stones. (See note to page 115.) Compare Valckenaer, 'Diatribe in Eurip.
perd. Dram. Reliquias', 1767, p. 30. Diog. Laert., ii., 40. Hence, among the
Greek philosophers, we find four hypotheses regarding the origin of falling
stars: a telluric origin from ascending exhalations; masses of stone raised by
hurricane (see Aristot., 'Meteor., lib. i., cap. iv., 2-13, and cap. vii., 9); a
solar origin; and, lastly, an origin in the regions of space, as heavenly
bodies which had long remained invisible. Respecting this last opinion,
which is that of Diogenes of Apollonia, and entirely accords with that of the
present day, see pages 124 and 125. It is worthy of remark, that in Syria, as
I have been assured by a learned Orientalist, now resident at Smyrna,
Andrea de Nericat, who instructed me in Persian, there is a popular belief
that aërolites chiefly fall on clear moonlight nights. The ancients, on the
contrary, especially looked for their fall during lunar eclipses. (See Pliny,
xxxvii., 10, p. 164. Solinus, c. 37. Salm., 'Exere.', p. 531; and the passages
collected by Ukert, in his 'Geogr. der Griechen und Römer', th. ii., 1, s. 131,
note 14.) On the improbability that meteoric masses are formed from metal-
dissolving gases, which, according to Fusinieri, may exist in the highest
strata of our atmosphere, and previously diffused through an almost
boundless space, may suddenly assume a solid condition, and on the
penetration and misceability of gases, see my ' Relat. Hist.', t. i., p. 525.

p 122 The view of the original existence of p 123 small planetary masses
in space is simpler, and at the same time, more analogous with those

entertained concerning the formation of other portions of the solar system.

It is very probable that a large number of these cosmical bodies traverse
space undestroyed by the vicinity of our atmosphere, and revolve round the
Sun without experiencing any alteration but a slight increase in the
eccentricity of their orbits, occasioned by the attraction of the Earth's mass.
We may, consequently, suppose the possibility of these bodied remaining
invisible to us during many years and frequent revolutions. The supposed
phenomenon of ascending shooting stars and fire-balls, which Chladni has
unsuccessfully endeavored to explain on the hypothesis of the 'reflection' of
strongly compressed air, appears at first sight as the consequence of some
unknown tngential force propelling bodies from the earth; but Bessel has
shown by theoretical deductions, confirmed by Feldt's carefully-conducted
calculations, that, owing to the absence of any proofs of the simultaneous
occurrence of the observed disappearances, the assumptiopn of an ascent of
shooting stars was rendered wholly improbable, and inadmissible as a result
of observation.*

[footnote] *Bessel, in Schum., 'Astr. Nachr.', 1839, No 389 und 381, s.
222 und 346. At the conclusion of the Memoir there is a comparison of the
Sun's longitudes with the epochs of the November phenomenon, from the
period of the first observations in Cumana in 1799,

The opinion advanced by Olbers that the explosion of shooting stars and
ignited fire-balls not moving in straight lines may impel meteors upward in
the manner of rockets, and influence the direction of their orbits, must be
made the subject of future researches.

Shooting stars fall either seprately and in inconsiderable numbers, that is,
sporadically, or in swarms of many thousands. p 124 The latter, which are

compared by Arabian authors to swarms of locusts, are periodic in their
occurrence, and move in streams, generally in a parallel direction. Among
periodic falls, the most celebrated are that known as the November
phenomenon, occurring from about the 12th to the 14th of November, and
that of the festival of St. Lawrence (the 10th of August), whose "fiery tears"
were noticed in former times in a church calendar of England, no less than
in old traditionary legends, as a meteorological event of constant
recurrence.*

[footnote] *Dr. Thomas Forster ('The Pocket Encyclopedia of Natural
Phenomena' 1827, p. 17) states that a manuscript is preserved in the library
of Christ's College, Cambridge,** written in the tenth century by a monk,
and entitled 'Ephemerides Rerum Naturalium', in which the natural
phenomena for each day of the year are inscribed as, for instance, the first
flowering of plants, the arrival of birds, etc.; the 10th of August is
distinguished by the word "meteorodes." It was this indication, and the
tradition of the fiery tears of St. Lawrence, that chiefly induced Dr. Forster
to undertake his extremely zealous investigation of the August phenomena.
(Quetelet, 'Correspond. Mathém.', Série III., t. i., 1837, p. 433.)

[further footnote] **[No such manuscript is at present known to exist in
the library of that college. For this information I am indebted to the
inquiries of Mr. Cory, of Pembroke College, the learned editor of
'Hieroglyphics of Horapollo Nilous', Greek and English, 1840.] — Tr.

Notwithstanding the great quantity of shooting stars and fire-balls of the
most various dimensions, which, according to Klöden, were seen to fall at
Potsdam on the night between the 12th and 13th of November, 1822, and on
the same night of the year in 1832 throughout the whole of Europe, from
Portsmouth to Orenburg on the Ural River, and even in the southern
hemisphere, as in the Isle of France, no attention was directed to the

'periodicity' of the phenomenon, and no idea seems to have been entertained
of the connection existing between the fall of shooting stars and the
recurrence of certain days, until the prodigious swarm of shooting stars
which occurred in North America between the 12th and 13th of November,
1833, and was observed by Olmsted and Palmer. The stars fell on this
occasion, like flakes of snow, and it was calculated that at least 240,000 had
fallen during a period of nine hours. Palmer, of New Haven, Connecticut,
was led, in consequence of this splendid phenomenon, to the recollection of
the fall of meteoric stones in 1799, first described by Ellicot and myself,*
and which, by p 125 a comparison of the facts I had adduced, showed that
the phenomenon had been simultaneously seen in the New Continent, from
the equator to New Herrnhut in Greenland (65 degrees 14' north latitude),
and between 46 degrees and 82 degrees longitude.

[footnote] *Humb., 'Rel. Hist.', t. i., p. 519-527. Ellicot in the
'Transactions of the American Society', 1804, vol. vi., . 29. Arago makes the
following observations in reference to the November phenomena: "We thus
become more and more confirmed in the belief that there exists a zone
composed of millions of small bodies, whose orbits cut the plane of the
ecliptic at about the point which out Earth annually occupies between the
11th and 13th of November. It is a new planetary world beginning to be
revealed to us." ('Annuaire', 1836, p. 296.)

The identity of the epochs was recognized with astonishment. The stream
which had been seen from Jamaica to Boston (40 degrees 21' north latitude)
to traverse the whole vault of heaven on the 12th and 13th of November,
1833, was again observed in the United States in 1834, on the night
between the 13th and 14th of November, although on this latter occasion it
showed itself with somewhat less intensity. In Europe the periodicity of the
phenomenon has since been manifested with great regularity.

Another and a like regularly recurring phenomenon is that noticed in the
month of August, the meteoric stream of St. Lawrence, appearing between
the 9th and 14th of August. Muschenbrock,* as early as in the middle of the
last century, drew attention to the frequency of meteors in the month of
August' but their certain periodic return about the time of St. Lawrence's
day was first shown by Quetelet, Olbers, and Benzenberg.

[footnote] *Compare Muschenbroek, 'Introd. ad Phil. Nat.', 1762, t. ii., p.
1061; Howard, 'On the Climate of London', vol. ii., p. 23, observations of
the year 1806; seven years, therefore aftr the earliest observations of
Brandes (Benzenberg, 'über Sternschnuppen', s. 240-244); the August
observations of Thomas Forster, in Quetelet, op. cit., p. 438-453; those of
Adolph Erman, Boguslawski, and Kreil, in Schum., 'Jahrb.', 1838, s. 317-
330. Regarding the point of origin in Perseus, on the 10th of August, 1839,
see the accurate measurements of Bessel and Erman (Schum., 'Astr. Nachr.',
No. 385 und 428); but on the 10th of August, 1837, the path does not apper
to have been retrograde; see Arago in 'Comptes Rendus', 1837, t. ii., p. 183.

We shall, no doubt, in time, discover other periodically appearing
streams,* probably about the 22d to the p. 126 25th of April, between the
6th and 12th of December, and, to judge by the number of true falls of
aërolites enumerated by Capocci, also between the 27th and 29th of
November, of about the 17th of July.

[footnote] *On the 25th of April, 1095, "innumerable eyes in France saw
stars falling from heaven as thickly as hail" ('ut grando, nisi lucerent, pro
densitate putaretur'; Baldr., p. 88), and this occurrence was regarded by the
Council of Clermont as indicative of the great movement in Christendom.
(Wilken, 'Gesch. der Kreuzzüge', bd. i., s. 75.) On the 25th of April, 1800, a
great fall of stars was observed in Virginia and Massachusetts; it was "a fire

of rockets that lasted two hours." Arago was the first to call attention to the
"trainée d'asteroïdes," as a recurring phenomenon. ('Annuaire', 1836, p.
297.) The falls of aërolites in the beginning of the month of December are
also deserving of notice. In reference to their periodic recurrence as a
meteoric stream, we may mention the early observation of Brandes on the
night of the 6th and 7th of December, 1798 (when he counted 2000 falling
stars), and very probably the enormous fall of aërolites that occurred at the
Rio Assu, near the village of Macao, in the Brazils, on the 11th of
December, 1836. (Brandes, 'Unterhalt. für Freunde der Physik', 1825, heft
i., s. 65, and 'Comptes Rendus', t. v., p. 211.) Capocci, in the interval
between 1809 and 1839, a space of thirty years, has discovered twelve
authenticated cases of aërolites occurring between the 27th and 29th of
November, besides others on the 13th of November, the 10th of August, and
the 17th of July. ('Comptes Rendus', t. xi., p. 357.) It is singular that in the
portion of the Earth's path corresponding with the months of January and
February, and probably also with March, no 'periodic' streams of falling
stars of aërolites have as yet been noticed; although when in the South Sea
in the year 1803, I observed on the 15th of March a remarkably large
number of falling stars, and they were seen to fall as in a swarm in the city
of Quito, shortly before the terrible earthquake of Riobamba on the 4th of
February, 1797. From the phenomena hitherto observed, the following
epochs seem especially worthy of remark: 22d to the 25th of April. 17th of
July (17th to the 26th of July?). (Quet., 'Corr.', 1837, p. 435.) 10th of
August. 12th to the 14th of November. 27th to the 29th of November. 6th to
the 12th of December. When we consider that the regions of space must be
occupied by myriads of comets, we are led by analogy, notwithstanding the
differences existing between isolated comets and rings filled with asteroids,
to regard the frequency of these meteoric streams with less astonishment
than the first consideration of the phenomenon would be likely to excite.

Although the phenomena hitherto observed appear to have been
independent of the distance from the pole, the temperature of the air, and
other climatic relations, there is, however, one perhaps accidentally
coincident phenomenon which must not be wholly disregarded. The
Northern Light, the Aurora Borealis, was unusually brilliant on the
occurrence of the Borealis, was unusually brilliant on the occurrence of the
splendid fall of meteors of the 12th and 13th November, 1833, described by
Olmsted. It was also observed at Bremen in 1838, where the periodic
meteoric fall was, however, less remarkable than at Richmond, near
London. I have mentioned in another work the singular fact observed by
Admiral Wrangel, and frequently confirmed to me by himself,* that when
he p 127 was on the Siberian coast of the Polar Sea, he observed, during an
Aurora Borealis, certain portions of the vault of heaven which were not
illuminated, light up and continue luminous whenever a shooting star
passed over them.

[footnote] *Ferd. v. Wrangle, 'Reise längs der Nordküste von Sibirien in
den Jahren', 1820-1824, th. ii., s. 259. Regarding the recurrence of the
denser swarm of the November stream after an interval of thirty-three years,
see Olbers, in 'Jahrb.', 1837, s. 280. I was informed in Cumana that shortly
before the fearful earthquake of 1766, and consequently thirty-three years
(the same interval) before the great fall of stars on the 11th and 12th of
November, 1799, a similar fiery manifestation had been observed in the
heavens. But it was on the 21st of October, 1766, and not in the beginning
of November, that the earthquake occurred. Possibly some traveler in Quito
may yet be able to ascertain the day on which the volcano of Cayambe,
which is situated there, was for the space of an hour enveloped in falling
stars, so that the inhabitants endeavored to appease heaven by religious
processions. ('Relat. Hist.', t. i., chap. iv., p 307; chap. x., p. 520 and 527.)

The different meteoric streams, each of which is composed of myriads of
small cosmical bodies, probably intersect our Earth's orbit in the same
manner as Biela's comet. According to this hypothesis, we may represent to
ourselves these asteroid-meteors as composing a closed ring or zone, within
which they all pursue one common orbit. The s aller planets between Mars
and Jupiter present us if we except Pallas with an analogous relation in their
constantly intersecting orbits. As yet, however, we have no certain
knowledge as to whether changes in the periods at which the stream
becomes visible, or the 'retardations' of the phenomena of which I have
already spoken, indicate a regular precession of oscillation of the nodes —
that is to say, of the points of intersection of the Earth's orbit and of that of
the ring; or whether this ring or zone attains so considerable a degree of
breadth from the irregular grouping and distances apart of the small bodies,
that it requires several days for the Earth to traverse it. The system of
Saturn's satellites shows us likewise a group of immense width, composed
of most intimately-connected cosmical bodies. In this system, the orbit of
the outermost (the seventh) satellite has such a vast diameter, that the Earth,
in her revolution round the Sun, requires three days to traverse an extent of
space equal to this diameter. If, therefore, in one of these rings, which we
regard as the orbit of a periodical stream, the asteroids should be so
irregularly distributed as to consist of but few groups sufficiently dense to
give rise to these phenomena, we may easily understand why we so seldom
witness such glorious spectacles as those exhibited in the November months
of 1799 and 1833. The acute mind of Olbers led him almost to predict that
the next appearance of the phenomenon of shooting stars and fire-balls
intermixed, falling like flakes of snow, would not recur until between the
12th and 14th of November, 1867.

p 128 The stream of the November asteroids has occasionally only been
visible in a small section of the Earth. Thus, for instance, a very splendid
'meteoric shower' was seen in England in the year 1837, while a most

attentive and skillful observer at Braunsberg, in Prussia only saw on the
same night, which was there uninterruptedly clear, a few sporadic shooting
stars fall between seven o'clock in the evening and sunrise the next
morning. Bessel* concluded from this "that a dense group of the bodies
composing the great ring may have reached that part of the Earth in which
England is situated, while the more eastern districts of the Earth might be
passing at the time through a part of the meteoric ring proportionally less
densely studded with bodies."

[footnote] *From a letter to myself, dated Jan. 24th, 1838. The enormous
swarm of falling stars in November, 1799, was almost exclusively seen in
America, where it was witnessed from New Herrnhut in Greenland to the
equator. The swarms of 1831 and 1832 were visible only in Europe, and
those of 1833 and 1834 only in the United States of North America.

If the hypothesis of a regular progression or oscillation of the nodes
should acquire greater weight, special interest will be attached to the
investigation of older observations. The Chinese annals, in which great falls
of shooting stars, as well as the phenomena of comets, are recorded, go
back beyond the age of Tyrtæs, or the second Messenian war. They give a
description of two streams in the month of March, one of which is 687
years anterior to the Christian era. Edward Biot has observed that among
the fifty-two phenomena which he has collected from the Chinese annals,
those that were of most frequent recurrence are recorded at periods nearly
corresponding with the 20th and 22d of July, O.S., and might consequently
be identical with the stream of St. Lawrence's day, taking into account that
it has advanced since the epochs* indicated.

[footnote] *Lettre de M. Edouard Biot à M. Quetelet, sur les anciennes
apparitions d'Etoiles Filantes en Chine, in the 'Bull. de l'Académie de
Bruxelles', 1843, t. x., No. 7, p. 8. On the notice from the 'Chronicon
Ecclesiæ Pragensis', see the younger Boguslawski, in Poggend., 'Annalen',
bd. xlviii., s. 612.

If the fall of shooting stars of the 21st of October, 1366, O.S. (a notice of
which was found by the younger Von Boguslawski, in Benessius de
Horowic's 'Chronicon Ecclesiæ Pragensis'), be identical with our November
phenomenon, although the occurrence in the fourteenth century was seen in
broad daylight, we find by the precession in 477 years that this system of
meteors, or, rather, its common center of gravity, must describe p 129 a
retrograde orbit round the Sun. It also follows, from the views thus
developed, that the non-appearance, during certain years, in any portion of
the Earth, of the two streams hitherto observed in November and about the
time of St. Lawrence's day, must be ascribed either to an interruption in the
meteoric ring, that is to say, to intervals occurring between the asteroid
groups, or, according to Poisson to the action of the larger planets* on the
form and position of this annulus.

[footnote] *"It appears that an apparently inexhaustible number of
bodies, too small to be observed, are moving in the regions of space, either
around the Sun or the planets, or perhaps even around their satellites. It is
supposed that when these bodies come in contact with our atmosphere, the
difference between their velocity and that of our planet is so great, that the
friction which they experience from their contact with the air heats them to
incandescence, and sometimes causes their explosion. If the group of falling
stars form an annulus around the Sun, its velocity of circulation may be
very different from that of our Earth; and the displacements it may
experience in space, in consequence of the actions of the various planets,

may render the phenomenon of its intersecting the planes of the ecliptic
possible at some epochs, and altogether impossible at others." — Poisson,
'Recherches sur la Probabilité des Jugements', p. 306, 307.

The solid masses which are observed by night to fall to the earth from
fire-balls, and by day generally when the sky is clear, from a cark small
cloud, are accompanied by much candescence. They undeniably exhibit a
great degree of general identity with respect to their external form, the
character of their crust, and the chemical composition of their principal
constituents. These characteristics of identity have been observed at all the
different epochs and in the most various parts of the earth in which these
meteoric stones have been found. This striking and early-observed analogy
of physiognomy in the denser meteoric masses is, however, met by many
exceptions regarding individual points. What differences, for instance, do
we not find between the malleable masses of for instance, do we not find
between the malleable masses of iron of Hradeschina in the district of
Agram, those from the shores of the Sisim in the government of Jeniseisk,
rendered so celebrated by Pallas, or those which I brought from Mexico,*
all of which contain 96 per cent. of iron, from the aërolites of Siena, in
which the iron scarcely amounts to 2 per cent., or the earthy aërolite of
Alais (in the Department du Gard), which broke up in water, or, lastly, from
those of Jonzac and Javenas, which contained no metallic iron, but
presented a p 130 mixture of oryctognostically distinct crystalline
compoonents!

[footnote] *Humboldt, 'Essai Politique sur la Nouv. Espagne' (2de édit.),
t. iii. p. 310.

These differences have led mineralogists to separate these cosmical
masses into two classes, namely, those containing nickelliferous meteoric
iron, and those consisting of fine or coarsely-granular meteoric dust. The
crust or rind of aërolites is peculiarly characteristic of these bodies, being
only a few tenths of a line in thickness, often glossy and pitch-like, and
occasionally veined.*

[footnote] *The peculiar color of their crust was observed even as early
as in the time of Pliny (ii., 56 and 58): "colore adusto." The phrase
"lateribus pluisse" seems also to refer to the burned outer surface of
aërolites.

There is only one instance on record, as far as I am aware (the aërolite of
Chantonnay, in La Vendée), in which the rind was absent, and this meteor,
like that of Juvenas, presented likewise the peculiarity of having pores and
vesicular cavities. In all other cases the black crust is divided from the inner
light-gray mass by as sharply-defined a line of separation as is the black
leaden-colored investment of the white granit blocks* which I brought from
the cataracts of the Orinoco, and which are also associated with many other
cataracts, as, for instance, those of the Nile and of the Congo River.

[footnote] * Humb., 'Rel. Hist.', t. ii., chap xx., p. 299-302.

The greatest heat employed in our porcelain ovens would be insufficient
to produce any thing similar to the crust of meteoric stones, whose interior
remains wholly unchanged. Here and there, facts have been observed which
would seem to indicate a fusion together of the meteoric fragments; but, in
general, the character of the aggregate mass, the absence of compression by

the fall, and the inconsiderable degree of heat possessed by these bodies
when they reach the earth, are all opposed to the hypothesis of the interior
being in a state of fusion during their short passage from the boundary of
the atmosphere to our Earth.

The chemical elements of which these meteoric masses consist, and on
which Berzelius has thrown so much light, are the same as those distributed
throughout the earth's crust, and are fifteen in number, namely, iron, nickel,
cobalt, manganese, chromium, copper, arsenic, zinc, potash, soda, sulphur,
phosphorus, and carbon, constituting altogether nearly one third of all the
known simple bodies. Notwithstanding this similarity with the primary
elements into which inorganic bodies are chemically reducible, the aspect
of aërolites, owing to the mode in which their constituent parts are
compounded, presents, generally, some features foreign to our telluric rocks
and minerals. The pure native iron, which is almost always p 131 found
incorporated with aërolites, imparts to them a peculiar, but not
consequently, a 'selenic' character; for in other regions of space, and in other
cosmical bodies besides our Moon, water may be wholly absent, and
processes of oxydation of rare occurence.

Cosmical gelatinous vesicles, similar to the organic 'nostoc' (masses
which have been supposed since the Middle Ages to be connected with
shooting stars), and those pyrites of Sterlitamak, west of the Uralian
Mountains, which are said to have constituted the interior of hailstones,*
must both be classed among the mythical fables of meteorology.

[footnote] *Gustav Rose, 'Reise nach dem Ural', bd. II., s. 202.

Some few aërolites, as those composed of a finely granular tissue of
olivine, augite, and labradorite blended together* (as the meteoric stone

found at Juvenas, in the Department de l'Ardèche, which resembled
dolorite), are the only ones, as Gustav Rose has remarked, which have a
more familiar aspect.

[footnote] *Gustav Rose, in Poggend., 'Ann.', 1825, bd. iv., x. 173-192.
Rammelsberg, 'Erstes Suppl. zum chem. Handwörterbuche der
Mineralogie', 1843, s. 102. "It is," says the clear-minded observer Olbers, "a
remarkable but hitherto unregarded fact, that while shells are found in
secondary and tertiary formations, no 'fossil meteoric stones' have as yet
been discovered. May we conclude from this circumstance that previous to
the present and last modification of the earth's surface no meteoric stones
fell on it, although at the present time it appears probable, from the
researches of Schreibers, that 700 fall annually?" (Olbers, in Schum.,
'Jahrb.', 1838, s. 329.) Problematical nickelliferous masses of native iron
have been found in Northern Asia (at the gold-washing establishment at
Petropawlowsk, eighty miles southeast of Kusnezk), imbedded thirty-one
feet in the ground, and more recently in the Western Carpathians (the
mountain chain of Magura, at Szlanicz), both of which are remarkably like
meteoric stones. Compart Erman, 'Archiv für wissenschaftliche Kunde von
Russland', bd. i., s. 315, and Haidinger, 'Bericht über Szlaniczer Schürfe in
Ungarn.'

These bodiescontain, for instance, crystalline substances, perfectly
similar to those of our earth's crust; and in the Siberian mass of meteoric
iron investigated by Pallas, the olivine only differs from common olivine by
the absence of nickel, which is replaced by the oxyd of tin.*

[footnote] *Berzelius, 'Jahresber.', bd. xv., s. 217 und 231. Rammelsberg,
'Handwörterb., abth. ii., s. 25-28.

As meteoric olivine, like our basalt, contains from 47 to 49 per cent. of
magnesia, constituting, according to Berzelius, almost the half of the earthy
components of meteoric stones, we can not be surprised at the great
quantity of silicate of magnesia found in these cosmical bodies. If the
zërolite of Juvenas contain separable crystals of augite and labradorite, the
numerical relation of the constituents p 132 render it at least probable that
the meteoric masses of Chateau-Renard may be a compound of diorite,
consisting of hornblende and albite, and those of Blansko and Chantonnay
compounds of hornblende and labradorite. The proofs of the telluric and
atmospheric origin of aUerolites, which it is attempted to base upon the
oryctognostic analogies presented by these bodies, do not appear to me to
possess any great weight.

Recalling to mind the remarkable interview between Newton and
Conduit at Kensington,* I would ask why the elementary substances that
compose one group of cosmical bodies, or one planetary system, may not,
in a great measure, be identical?

[footnote] * "Sir Isaac Newton said he took all the planets to be
composed of the same matter with the Earth, viz., earth, water, and stone,
but variously connected." — Turner, 'Collections for the History of
Grantham, containing authentic Memoirs of Sir Isaac Newton', p. 172.

Why should we not adopt this view, since we may conjecture that these
planetary bodies, like all the larger or smaller agglomerated masses
revolving round the sun, have been thrown off from the once far more
expanded solar atmosphere, and been formed from vaporous rintgs
describing their orbits round the central body? We are not, it appears to me,
more justified in applying the term telluric to the nickel and iron, the olivine
and pyroxene (augite), found in meteoric stones, than in indicating the
German plants which I found beyond the Obi as European species of the

flora of Northern Asia. If the elementary substances composing a group of
cosmical bodies of different magnitudes be identical, why should they not
likewise, in obeying the laws of mutual attraction, blend together under
definite relations of mixture, composing the white glittring snow and ice in
the polar zones of the planet Mars, or constituting in the smaller cosmical
masses mineral bodies inclosing crystals of olivine, augite, and labradorite?
Even in the domain of pure conjecture we should not suffer ourselves to be
led away by unphilosophical and arbitrary views devoid of the support of
inductive reasoning.

Remarkable obscurations of the sun's disk, during which the stars have
been seen at mid-day (as, for instance, in the obscuration of 1547, which
continued for three days, and occurred about the time of the eventful battle
of Mühlberg), can not be explained as arising from volcanic ashes or mists,
and were regarded by Kepler as owing either to a 'materia cometica', or to a
black cloud formed by the sooty exhalations of the solar body. The shorter
obscurations of 1090 and 1203, which continued, the one only three, and
the other six p 133 hours, were supposed by Chladni and Schnurrer to be
occasioned by the passage of meteoric masses before the sun's disk. Since
the period that streams of meteoric shooting stars were first considered with
reference to the direction of their orbit as a closed ring, the epochs of these
mysterious celestial phenomena have been observed to present a remarkable
connection with the regular recurrence of swarms of shooting stars Adolph
Erman has evinced great acuteness of mind in his accurate investigation of
the facts hitherto observed on this subject, and his researches have enabled
him to discover the connection of the sun's conjunction with the August
asteroids on the 7th of February, and with the November asteroids on the
12th of May, the latter period corresponding with the days of St. Mamert
(May 11th), St. Pancras (May 12th), and St. Servatius (May 13th), which
according to popular belief, were accounted "cold days."*

[footnote] Adolph Erman, in Poggend., 'Annalen', 1839, bd. xlviii., s.
582-601. Biot had previously thrown doubt regarding the probability of the
November stream reappearing in the beginning of May ('Comptes Rendus',
1836, t. ii., p. 670). Mädler has examined the mean depression of
temperature on the three ill-named days of May by Berlin observations for
eighty-six years ('Verhandl. des Vereins zur Bedförd, des Gartenbaues',
1834, s. 377), and found a retrogression of temperature amounting to 2.2
degrees Fahr. from the 11th to the 13th of May, a period at which nearly the
most rapid advance of heat takes place. It is much to be desired that this
phenomenon of depressed temperature, which some have felt inclined to
attribute to the melting of the ice in the northeast of Europe, should be also
investigated in very remote spots, as in America, or in the southern
hemisphere. (Comp. 'Bull. de l'Acad. Imp. de St. Pétersbourg', 1843, t. i.,
No. 4.)

The Greek natural philosophers, who were but little disposed to pursue
observations, but evinced inexhaustible fergility of imagination in giving
the most various interpretation of half-perceived facts, have, however, left
some hypotheses regarding shooting stars and meteoric stones which
strikingly accord with the views now almost universally admitted of the
cosmical process of these phenomena. "Falling stars," says Plutarch, in his
life of Lysander,* are, according to the opinion of some physicists, not
eruptions of the ethereal fire extinguished in the air immediately after its
ignition, nor yet an inflammatory combustion of the air, which is dissolved
in large quantities in the upper regions of space, but these meteors are rather
a fall of celestial bodies, which, in consequence of a certain intermission in
the rotatory force, and by the impulse of some irregular movements, have
been hurled down not only to the inhabited portions of the Earth, but also
beyond it into the great ocean, where we can not find them."

[footnote] *Plut., 'Vitæ par, in Lysandro', cap. 22. The statement of
Damachos (Daïmachos), that for seventy days continuously there was a
fiery cloud seen in the sky, emitting sparks like falling stars, and which
then, sinking nearer to the earth, let fall the stone of Ægos Potamos, "which,
however, was only a small part of it," is extremely improbable, since the
direction and velocity of the fire-cloud would in that case of necessity have
to remain for so many days the same as those of the earth; and this, in the
fire-ball of the 19th of July, 1686, described by Halley ('Trans.', vol. xxix.,
p. 163), lasted only a few minutes. It is not altogether certain whether
Daïmachos, the writer, [Greek words], was the same person as Daïmachos
of Platæa, who was sent by Selencus to India to the son of Androcottos, and
who ws charged by Strabo with being "a speaker of lies" (p. 70, Casaub.).
From another passage of Plutarch ('Compar. Solonis c. Cop.', cap. 5) we
should almost believe that he was. At all events, we have here only the
evidence of a very late author, who wrote a century and a half after the fall
of aërolites occurred in Thrace, and whose authenticity is also doubted by
Plutarch.

Diogenes of Apollonia* expresses himself still more explicitly.

[footnote] *Stob., ed. Heeren, i., 25, p. 508; Plut., 'de plac. Philos.', ii.,
13.

According to his views, "Stars that are 'invisible', and, consequently, have
no name, move in space together with those that are visible. These invisible
stars frequently fall burning at Ægos Potamos." The Apollonian, who held
all other stellar bodies, when luminous, to be of a pumice-like nature,
probably grounded his opinions regarding shooting stars and meteoric
masses on the doctrine of Anaxagoras the Clazomenian, who regarded all

the bodies in the universe "as fragments of rocks, which the fiery ether, in
the force of its gyratory motion, had torn from the Earth and converted into
stars." In the Ionian school, therefore, according to the testimony
transmitted to us in the views of Diogenes of Apollonia, aërolites and stars
were ranged in one and the same class; both, when considered with
reference to their primary origin, being equally telluric, this being
understood only so far as the Earth was then regarded as a central body,* p
135 forming all things around it in the same manner was we, according to
our present views, suppose the planets of our system to have originated in
the expanded atmosphere of another central body, the Sun.

[footnote] *The remarkable passage in Plut., 'de plac. Philos.', ii., 13,
runs thus: "Anaxagoras teaches that the surrounding ether is a fiety
substance, which, by the power of its rotation, tears rocks from the earth,
inflames them, and converts them into stars." Applying an ancient fable to
illustrate a physical dogma, the Clazomenian appears to have ascribed the
fall of the Nemæan Lion to the Peloponnesus from the Moon to such a
rotatory or centrifugal force. (Ælian., xii., 7; Plut., 'de Facie in Orge Lunæ'
c. 24; Schol. ex Cod. Paris., in 'Apoll. Argon.', lib. i., p. 498, ed. Schaef., t.
ii., p. 40; Meineke, 'Annal. Alex.', 1843, p. 85.) Here, instead of stones from
the Moon, we have an animal from the Moon! According to an acute
remark of Böckh, the ancient mythology of the Nemæan lunar lion has an
astronomical origin, and is symbolically connected in chronology with the
cycle of intercalation of the lunar year, with the moon-worship at Nemæa,
and the games by which it was accompanied.

These views must not, therefore, be confounded with what is commonly
termed the telluric or atmospheric origin of meteoric stones, nor yet with
the singular opinion of Aristotle, which supposed the enormous mass of
Ægos Potamos to have been raised by a hurricane. That rrogant spirit of

incredulity, which rejects facts without attempting to investigate them, is in
some cases almost more injurious than an unquestioning credulity. Both are
alike detrimental to the force of investigation. Notwithstanding that for
more than two thousand years the annals of different nations had recorded
falls of meteoric stones, many of which had been attested beyond all doubt
by the evidence of irreproachable eye-witnesses — notwithstanding the
important part enacted by the Bætylia in the meteor-worship of the ancients
— notwithstanding the fact of the companions of Cortez having see an
aërolite at Cholula which had fallen on the neighboring pyramid —
notwithstanding that califs and Mongolian chiefs had caused swords to be
forged from recently-fallen meteoric stones — nay, notwithstanding that
several persons had been struck dead by stones falling from heaven, as for
instance, a monk at Crema on the 4th of September, 1511, another monk at
Milan in 1650, and two Swedish sailors on board ship in 1674, yet this great
cosmical phenomenon remained almost wholly unheeded, and its intimate
connection drawn to the subject by Chladni, who had already gained
immortal renown by his discovery of the sound-figures. He who is
penetrated with a sense of this mysterious connection, and whose mind is
open to deep impressions of nature, will feel himself moved by the deepest
and most solemn emotion at the sight of every star that shoots across the
vault of heaven, no less than at the glorious spectacle of meteoric swarms in
the November phenomenon or on St. Lawrence's day. Here motion is
suddenly revealed in the midst of nocturnal rest. The still radiance of the
vault of heaven is for a moment animated with life and movement. In the
mild radiance left on the track of the shooting star, imagination pictures the
lengthened path of the meteor through the vault of heaven, p 136 while,
every where around, the luminous asteroids proclaim the existence of one
common material universe.

If we compare the volume of the innermost of Saturn's satellites, or that
of Ceres, with the immense volume of the Sun, all relations of magnitude

vanish from our minds. The extinction of suddenly resplendent stars in
Cassiopeia, Cygnus, and Serpentarius have already led to the assumption of
other and non-luminous cosmical bodies. We now know that the meteoric
asteroids, spherically agglomerated into small masses, revolve round the
Sun, intersect, like comets, the orbits of the luminous larger planets, and
become ignited either in the vicinity of our atmosphere or in its upper strata.

The only media by which we are brought in connection with other
planetary bodies, and with all portions of the universe beyond our
atmosphere, are light and heat (the latter of which can scarcely be separated
from the former),* and those mysterious powers of attraction exercised by
remote masses, according to the quantity of their constituents, upon our
globe, the ocean, and the strata of our atmosphere.

[footnote' *The following remarkable passage on the radiation of heat
from the fixed stars, and on their low combustion and vitality — one of
Kepler's many aspirations — occurs in the 'Paralipom. in Vitell. Astron.
parsOpticqa', 1604, Propos. xxxii., p. 25: "Luciis proprium est calor, sydera
omnia calefaciunt. De syderum luce claritatis ratio testatur, calorem
universorum in minori esse proportione ad calorem unius solis, quam ut ab
homine, cujus est certa caloris mensura, utrque simul percipi et judicari
possit. De cincindularum lucula tenuissima negare non potes, quin cum
calore sit. Vivunt enim et moventur, hoc auten non sine calefactione
perficitur. Sic neque putrescentium lignorum lux sui calore destituitur; nam
ipsa puetredo quidam lentus ignis est. Inest et stirpibus suus calor."
(Compare Kepler, 'Epit. Astron. Copernicanæ', 1618, t. i., lib. i., p. 35.)

Another and different kind of cosmical, or, rather, material mode of
contact is, however, opened to us, if we admit falling stars and meteoric
stones to be planetary asteroids. They not only act upon us merely from a

distance by the excitement of luminous or calorific vibrations, or in
obedience to the laws of mutual attraction, but they acquire an actual
material existence for us, reaching our atmosphere from the remoter regions
of universal space, and remaining on the earth itself. Meteoric stones are the
only means by which we can be brought in possible contact with that which
is foreign to our own planet. Accustomed to gain our knowledge of what is
not telluric solely through measurement, calculations, and the deductions of
reason, we experience a sentiment of astonishment at finding that we may
examine, weigh, and analyze bodies that appertain p 137 to the outer world.
This awakens, by the power of the imagination, a meditative, spiritual train
of thought, where the untutored mind perceives only scintillations of light
in the firmament, and sees in the blackened stone that falls from the
exploded cloud nothing beyond the rough product of a powerful natural
force.

Although the asteroid-swarms, on which we have been led, from special
predilection, to dwell somewhat at length, approximate to a certain degree,
in their inconsiderable mass and the diversity of their orbits, to comets, they
present this essential difference from the latter bodies, that our knowledge
of their existence is almost entirely limited to the moment of their
destruction, that is, to the period when, drawn within the sphere of the
Earth's attraction they become luminous and ignite.

In order to complete our view of all that we have learned to consider as
appertaining to our solar system, which now, since the discovery of the
small planets, of the interior comets of short revolutions, and of the
meteoric asteroids, is so rich and complicated in its form, it remains for us
to speak of the ring of Zodiacal light, to which we have already alluded.
Those who have lived for many years in the zone of palms must retain a
pleasing impression of the mild radiance with which the zodiacal light,
shooting pyramidally upward, illumines a part of the uniform length of

tropical nights. I have seen it shine with an intensity of light equal to the
milky way in Sagittarius, and that not only in the rare and dry atmosphere
of the summits of the Andes, at an elevation of from thirteen to fifteen
thousand feet, but even on the boundless grassy plains, the Illanos of
Venezuela, and on the sea-shore, beneath the ever-clear sky of Cumana.
This phenomenon was often rendered especially beautiful by the passage of
light, fleecy clouds, which stood out in picturesque and bold relief from the
luminous back-ground. A notice of this aërial spectacle is contained in a
passage in my journal, while I was on the voyage from Lima to the western
coasts of Mexico: "For three or four nights (between 10ºdegrees and
14ºdegrees north latitude) the zodiacal light has appeared in greater
splendor than I have ever observed it. The transparency of the atmosphere
must be remarkably great in this part of the Southern Ocean, to judge by the
radiance of the stars and nebulous spots. From the 14th to the 19th of March
a regular interval of three quarters of an hour occurred between the
disappearance of the sun's disk in the ocean and the first manifestation of
the zodiacal p 138 light, although the night was already perfectly dark. an
hour after sunset it was seen in great briliancy between Aldebaran and the
Pleiades; and on the 18th of March it attained an altitude of
39ºdegrees5'minutes. Narrow elongated clouds are scattered over the
beautiful deep azure of the distant horizon, flitting past the zodiacal light as
before a golden curtain. Above these, other clouds are from time to time
reflecting the most brightly variegated colors. It seems a second sunset. On
this side of the vault of heaven the lightness of the night appears to increase
almost as much as at the first quarter of the moon. Toward 10 o'clock the
zodiacal light generally becomes very faint in this part of the Southern
Ocean, and at midnight I have scarcely been able to trace a vestige of it. On
the 16th of March, when most strongly luminous a faint reflection was
visible in the east." In our gloomy so-called "temperate" northern zone, the
zodiacal light is only distinctly visible in the beginning of Spring, after the

evening twilight, in the western part of the sky, and at the close of Autumn,
before the dawn of day, above the eastern horizon.

It is difficult to understand how so striking a natural phenomenon should
have failed to attract the attention of physicists and astronomers until the
middle of the seventeenth century, or how it could have escaped the
observation of the Atabian natural philosophers in ancient Bactria, on the
euphrates, and in the south of Spain. Almost equal surprise is excited by the
tardiness of observation of the nebulous spots in Andromeda and Orion,
first described by Simon Marius and Huygens. The earliest explicit
descriptions of the zodiacal light occurs in Childrey's 'Britannia Baconica',*
in the year 1661. p 139

[footnote] *"There is another thing which I recommend to the
observation of mathematical men, which is that in February, and for a little
before and a little after that month (as I have observed several years
together), about six in the evening, when the twilight hath almost deserted
the horizon, you shall see a plainly discernible way of the twilight striking
up toward the Pleiades, and seeming almost to touch them. It is so observed
any clear night, but it is best illac nocte. There is no such way to be
observed at any other time of the year (that I can perceive), nor any other
way at that time to be perceived darting up elsewhere; and I believe it hath
been, and will be constantly visible at that time of the year; but what the
cause of it in nature should be, I can not yet imagine, but leave it to future
inquiry." (Childrey, 'Britannia Baconica', 1661, p. 183.) This is the first
view and a simple description of the phenomenon. (Cassini, 'Découverte de
la Lumi dfd éleste qui paroît dans le Zodiaque', in the 'Mém. de l'Acad.', t.
viii., 1730, p 276. Mairan, 'TraitéPhys de l'Aurore Boréale', 1754, 0. 16.) In
this remarkable work by Childrey there are to be found (p. 91) very clear
accounts of the epochs of maxima and minima diurnal and annual

temperatures, and of the retardation of the extremes of the effects in
meteorological processes. It is, however, to be regretted that our Baconian-
philosophy-loving author, who was Lord Henry Somerset's chaplain, fell
into the same error as Bernardin de St. Pierre, and regarded the Earth as
elongated at the poles (see p. 148). At the first he believes that the Earth
was spherical, but supposes that the uninterrupted and increasing addition
of layers of ice at both poles has changed its figure; and that as the ice is
formed from water, the quantity of that liquid is every where diminishing.

The first observation of the phenomenon may have been made two or
three years prior to this period; but, notwithstanding, the merit of having (in
the spring of 1683) been the first to investigate the phenomenon in all its
relations in space is incontestably due to Dominicus Cassini. The light
which he saw at Bologna in 1668, and which was observed at the same time
in Persia by the celebrated traveler Chardin (the court astrologers of Ispahan
called this light, which had never before been observed, 'nyzek', a small
lance), was not the zodiacal light, as has often been asserted,* but the p 140
enormous tail of a comet, whose head was concealed in the vapory mist of
the horizon, and which, from its length and appearance, presented much
similarity to the great comet of 1843.

[footnote] *Dominicus Cassini ('Mém. de l'Acad.', t. viii., 1730, p. 188),
and Mairan ('Aurore Bor.', p. 16), have even maintained that the
phenomenon observed in Persia in 1668 was the zodiacal light. Delambre
('Hist. de l'Astron. Moderne', t. ii., p. 742), in very decided trms ascribes the
discovery of this light to the celebrated traveler Chardin; but in the
'Couronnement de Soliman', and in several passages of the narrative of his
travels (éd. de Langlès. t. iv., p. 326; t. x., p. 97), he only applies the term
niazouk (nyzek), or "petite lance," to "the great and famous comet which
appeared over nearly the whole world in 1668, and whose head was so

hidden in the wewst that it could not be perceived in the horizon of
Ispahan" ('Atlas du Voyage de Chardin', Tab. iv.; from the observations at
Schiraz). The head or nucleus of the comet was, however, visible in the
Brazils and in India (Pingré, 'Cométogr.', t. ii., p. 22). Regarding the
conjectured identity of the last great comet of March, 1843, with this, which
Cassini mistook for the zodiacal light, see Schum., 'Astr. Nachr.', 1843, No.
476 and 480. In Persian, the term "nizehi âteschîn"(fiery spears or lances) is
also applied to the rays of the rising or setting sun, in the same way as
"nayâzik," according to Freytag's Arabic Lexicon, signifies "stellæ
cadentes." The comparison of comets to lances and swords was, however, in
the Middle Ages, very common in all languages. The great comet of 1500,
which was visible from April to June, was always termed by the Italian
writers of that time 'il Signor Astone' (see my 'Examen Critique de l'Hist. de
la Géographie', t. v., p. 80). All the hypotheses that have been advanced to
show that Descartes (Cassini, p. 230; Mairan, p. 16), and even Kepler
(Delambre, t. i., p. 601), were acquainted with the zodiacal light, appear to
me altogether untenable. Descartes ('Principes', iii., art. 136, 137) is very
obscure in his remarks on comets, observing that their tails are formed "by
oblique rays, which, falling on different parts of the planetary orbs, strike
the eye laterally by extraordinary refraction," and that they might be seen
morning and evening, "like a long beam," when the Sun is between the
comet and the Earth. This passage no more refers to the zodiacal light than
those in which Kepler ('Epit. Astron. Copernicanæ', t. i., p. 57, and t. ii., p.
893) speaks of the existence of a solar atmosphere (limbus circa solem,
coma lucida), which, in eclipses of the Sun, prevents it "from being quite
night:" and even more uncertain, or indeed erroneous, is the assumption that
the "trabes quas [Greek word] vocant" (Plin., ii., 26 and 27) had reference
to the tongue-shaped rising zodiacal light, as Cassini (p. 231, art. xxxi.) and
Mairan (p. 15) have maintained. Every where among the ancients the trabes
are associated with the bolides (ardores et faces) and other fiery meteors,

and even with long-barbed comets. (Regarding [Greek words] . see Schäfer,
'Schol. Par. ad Apoll. Rhod.', 1813, t. ii., p. 206; Pseudo-Aristot., 'de
Mundo, 2, 9; 'Comment. Alex. Joh. Philop. et Olymp. in Aristot. Meteor.',
lib. i., cap. vii., 3, p. 195, Ideler; Seneca, 'Nat. Quæst.', i., 1.)

We may conjecture, with much probability, that the remarkable light on
the elevated plains of Mexico, seen for forty nights consecutively i8n 1509,
and observed in the eastern horizon rising pyramidally from the earth, was
the zodiacal light. I found a notice of this phenomenon in an ancient Aztec
MS., the 'CodexTelleriano-Remensis',* preserved in the Royal Library at
Paris.

[footnote] *Humboldt, 'Monumens des Peuples Indigènes de l'Amérique',
t. ii., p. 301. The rare manuscript which belonged to the Archbishop of
Rheims, Le Tellier, contains various kinds of extracts from an Aztec ritual,
an astrological calendar, and historical annals, extending from 1197 to
1549, and embracing a notice of different natural phenomena, epochs of
earthquakes and comets (as, for instance, those of 1490 and 1529), and of
(which are important in relation to Mexican chronology) solar eclipses. In
Camargo's manuscript 'Historia de Tlascala', the light rising in the east
almost to the zenith is, singularly enough, described as "sparkling, and as if
sown with stars." The description of this phenomenon, which lasted forty
days, can not in any way apply to volcanic eruptions of Popcatepetl, which
lies very near, in the southeastery direction. (Prescott, 'History of the
Conquest of Mesico', vol. i., p. 284.) Later commentators have confounded
this phenomenon, which Montezuma regarded as a warning of his
misfortunes, with the "estrella que humeava" (literally, 'which spring forth';
Mexican 'choloa, to leap or spring forth'). With respect to the connection of
this vapor with the star Citlal Choloha (Venus) and with "the mountain of

the star" (Citialtepetl, the volcano of Orizaba), see my 'Monumens', t. ii., p.
303.

This phenomenon, whose primordial antiquity can scarcely be doubted,
and which was first noticed in Europe by Childrey and Dominicus Cassini,
is not the luminous solar atmosphere itself, since this can not, in accordance
with mechanical laws, be more compressed than in the relation of 2 to 3,
and consequently can not be diffused beyond 9/20ths of Mercury's
heliocentric distance. These same laws teach us that the altitude of the
extreme boundaries of the atmosphere of a cosmical p 141 body above its
equator, that is to say, the point at which gravity and centrifugal force are in
equilibrium, must be the same as the altitude at which a satellite would
rotate round the central body simultaneously with the diurnal revolution of
the latter.*

[footnote] *Laplace, 'Expos. du Syst. du Monde', p. 270; 'Mécanique
Céleste', t. ii., p. 169 and 171; Schubert, 'Astr.', bd. iii., § 206.

This limitation of the solar atmosphere in its present concentrated
condition is especially remarkable when we compare the central body of
our system with the nucleus of other nebulous stars. Herschel has
discovered several, in which the radius of the nebulous matter surrounding
the star appeared at an angle of 150". On the assumption that the parallax is
not fully equal to 1", we find that the outermost nebulous layer of such a
star must be 150 times further from the central body than our Earth is from
the Sun. If, therefore, the nebulous star were to occupy the place of our Sun,
its atmosphere would not only include the orbit of Uranus, but even extend
eight times beyond it.•

[footnote] *Arago, in the 'Annuaire', 1842, p. 408. Compare Sir John
Herschel's considerations on the volume and faintness of light of planetary
nebulæ, in Mary Somerville's 'Connection of the Physical Sciences', 1835,
p. 108. The opinion that the Sun is a nebulous star, whose atmosphere
presents the phenomenon of zodiacal light, did not originate with
Dominicus Cassini, but was first promulgated by Mairan in 1730 ('Traité de
l'Aurore Bor.', p. 47 and 263; Arago, in the 'Annuaire', 1842, p. 412). It is a
renewal of Kepler's views.

Considering the narrow limitation of the Sun's atmosphere, which we
have just described, we may with much probability regard the existence of a
very compressed annulus of nebulous matter,* revolving freely in space
between the orbits of Venus and Mars, as the material cause of the zodiacal
light.

[footnote] *Cominicus Cassini was the first to assume, as did
subsequently Laplace, Schubert, and Poisson, the hypothesis of a separate
ring to explain the form of the zodiacal light. He says distinctly, "If the
orbits of Mercury and Venus were visible (throughout their whole extent),
we should invariably observe them with the same figure and in the same
position with regard to the Sun, and at the same time of the year with the
zodiacal light." ('Mém. de l'Acad.', t. viii., 1730, p. 218, and Biot, in the
'Comptes Rendus', 1836, t. iii., p. 666.) Cassini believed that the nebulous
ring of zodiacal light consisted of innumerable small planetary bodies
revolving round the Sun. He even went so far as to believe that the fall of
fire-balls might be connected with the passage of the Earth through the
zodiacal nebulous ring. Olmsted, and especially Biot (op. cit., p. 673), have
attempted to establish its connection with the November phenomenon — a
connection which Olbers doubts. (Schum., 'Jahrb.', 1837, s. 281.) Regarding
the question whether the place of the zodiacal light perfectly coincides with

that of the Sun's equator, see Houzeau, in Schum., 'Astr. Nachr.', 1843, No.
492, s. 190.

As p 142 yet we certainly know nothing definite regarding its actual
material dimensions; its augmentation* by emanations from the tails of
myriads of comets that come within the Sun's vicinity; the singular changes
affecting its expansion, since it sometimes does not apper to extend beyond
our Earth's orbit; or, lastly, regarding its conjectural intimate connection
with the more condensed cosmical vapor in the vicinity of the Sun.

[footnote] *Sir John Herschel, 'Astron.', § 487.

The nebulous particles composing this ring, and revolving round the sun
in accordance with planetary laws, may either be self-luminous or receive
light from that luminary. Even in the case of a terrestrial mist (and this fact
is very remarkable), which occurred at the time of the new moon at
midnight in 1743, the phosphorescence was so intense that objects could be
distinctly recognized at a distance of more than 600 feet.

I have occasionally been astonished in the tropical climates of south
america, to observe the variable intensity of the zodiacal light. As i passed
the nights, during many months, in the open air, on the shores of rivers and
on ilanos, i enjoyed ample opportunities of carefully examining this
phenomenon. When the zodiacal light had been most intense, i have
observed that it would be perceptibly weakened for a few minutes, until it
again suddenly shone forth in full brilliancy. In some few instances i have
thought that i could perceive — not exactly a reddish coloration, nor the
lower portion darkened in an arc-like form, nor even a scintillation, as

mairan affirms he has observed — but a kind of flickering and wavering of
the light.*

[footnote] *Arago, in the 'Annuaire', 1832, p. 246. Several physical facts
appear to indicate that, in a mechanical separation of matter into its smallest
particles, if the mass be very small in relation to the surface, the electrical
tension may increase sufficiently for the production of light and heat.
Experiments with a large concave mirror have not hitherto given any
positive evidence of the presence of radiant heat in the zodiacal light.
(Lettre de M. Matthiessen à M. Arago, in the 'Comptes Rendus', t. xvi.,
1843, Avril, p. 687.)

Must we suppose that changes are actually in progress in the nebulous
ring? or is it not more probable that, although I could not, by my
meteorological instruments, detect any change of heat or moisture near the
ground, and small stars of the fifth and sixth magnitudes appeared to shine
with equally undiminished intensity of light, processes of condensation may
be going on in the uppermost strata of the air, by means of which the
transparency, or rather, the reflection of light, may be modified in some
peculiar and unknown manner? p 143 An assumption of the existence of
such meteorological causes on the confines of our atmosphere is
strengthened by the "sudden flash and pulsation of light," which, according
to the acute observations of Olbers, vibrated for several seconds through the
tail of a comet, which appeared during the continuance of the pulsations of
light to be lengthened by several degrees, and then again contracted.*

[footnote] *"What you tell me of the changes of light in the zodiacal
light, and of the causes to which you ascribe such changes within the
tropics, is of the greatr interest to me, since I have been for a long time past

particularly attentive, every spring, to this phenomenon in our northern
latitudes. I, too, have always believed that the zodiacal light rotated; but I
assumed (contrary to Poisson's opinion, which you have communicated to
me) that it completely extended to the Sun, with considerably augmenting
brightness. The light circle which, in total solar eclipses, is seen
surrounding the darkened Sun, I have regarded as the brightest portion of
the zodiacal light. I have convinced my self that this light is very different
in different years, often for several successive years being very bright and
diffused, while in othr years it is scarcely perceptible. I tyhink that I find the
first trace of an allusion to the zodiacal light in a letter from Rothmann to
Tycho, in which he mentions that in the spring he has observed the twilight
did not close until the sun was 24ºdegrees below the horizon. Rothmann
must certainly have confounded the disappearance of the setting zodiacal
light in the vapors of the western horizon with the actual cessation of
twilight. I have failed to observe the pulsations of the light, probably on
account of the faintness with which it appears in these countries. You are,
however, certainly right in ascribing those rapid variations in the light of the
heavenly bodies, which you have perceived in tropical climates, to our own
atmosphere, and especially to its higher regions. This is especially in the
clearest weather, that these tails exhibit pulsations, commencing from the
head, as being the lowest part, and vibrating in one or two seconds through
the entire tail, which thus appears rapidly to become some degrees longer,
but again as rapidly contracts. That these undulations, which were formerly
noticed with attention by Robert Hooke, and in more recent times by
Schröter and Chladni, 'do not actually occur in the tails of the comets', but
are produced by our atmosphere, is obvious when we recollect that the
individual parts of those tails (which are many millions of miles in length)
lie 'at very different distances' from us, and that the light from their extreme
points can only reach us at intervals of time which differ several minutes
from one another. Whether what you saw on the Orinoco, not at intervals of

seconds, but of minutes, were actual coruscations of the zodiacal light, or
whether they belonged exclusively to the upper strata of our atmosphere, I
will not attempt to decide; neither can I explain the remarkable 'lightness of
whole nights', nor the anomalous augmentation and prolongation of the
twilight in the year 1831, particularly if, as has been remarked, the lightest
part of these singular twilights did not coincide with the Sun's place below
the horizon." (From a lettr written by Dr. Olbers to myself, and dated
Bremen, Marth 26th, 1833.)

As, however, the separate particles of a comet's tail, measuring millions
of miles, p 144 are very unequally distant from earth, it is not possible,
according to the laws of the velocity and transmission of light, that we
should be able, in so short a period of time, to perceive any actual changes
in a cosmical body of such vast extent. There considerations in no way
exclude the realith of the changes that have been observed in the
emanations from the more condensed envelopes around the nucleus of a
comet, nor that of the sudden irradiation of the zodiacal light, from internal
molecular motion, nor of the increased or diminished reflection of light in
the cosmical vapor of the luminous ring, but should simply be the means of
drawing our attention to the differences existing between that which
appertains to the air of heaven (the realms of universal space) and that
which belongs to the strata of our terrestrial atmosphere. It is not possible,
as well-attested facts prove, perfectly to explain the operations at work in
the much-contested upper boundaries of our atmosphere. The extraordinary
lightness of whole nights in the year 1831, during which small print might
be read at midnight in the latitudes of Italy and the north of Germany is a
fact directly at variance with all that we know, according to the most recent
and acute researches on the crepuscular theory, and of the height of the
atmosphere.*

[footnote] *Biot, 'Traité d'Astron. Physique', 3ème éd., 1841, t. i., p. 171,
238 and 312.

The phenomena of light depend upon conditions still less understood, and
their variability at twilight, as well as in the zodiacal light, excite our
astonishment.

We have hitherto considered that which belongs to our solare system —
that world of material forms governed by the Sun — which includes the
primary and secondary planets, comets of short and long periods of
revolution, meteoric asteroids, which move thronged together in streams,
either sporadically or in closed rings, and finally a luminous nebulous ring,
that revolves round the Sun in the vicinity of the Earth, and for which,
owing to its position, we may retain the name of zodiacal light. Every
where the law of periodicity governs the motions of these bodies, however
different may be the amount of tangential velocity, or the quantity of their
agglomerated material parts; the meteoric asteroids which enter our
atmosphere from the external regions of universal space are alone arrested
in the course of their planetary revolution, and retained within the sphere of
a larger planet. In the solar system, whose boundaries determine the
attractive force of the central body, comets are made to revolve in their
elliptical p 145 orbits at a distance 44 times greater than that of Uranus;
may, in those comets whose nucleus appears to us, from its inconsiderable
mass, like a mere passing cosmical cloud, the Sun exercises its attractive
force on the outermost parts of the emanations radiating from the tail over a
space of many millions of miles. Central forces, therefore, at once
constitute and maintain the system.

Our Sun may be considered as at rest when compared to all the large and
small, dense and almost vaporous cosmical bodies tht appertain to and
revolve around it; but it actually rotates around the common center of

gravity of the whole system, which occasionally falls within itself, that is to
say, remains within the material circumference of the Sun, whatever
changes may be assumed by the position of the planets. A very different
phenomenon is that presented by the translatory motion of the Sun, that is,
the progressive motion of the center of gravity of the whole solar system in
universal space. Its velocity is such* that, according to Bessel, the relative
motion of the Sun, and that of 61 Cygni, is not less in one day than
3,336,000 geographical miles.

[footnote] *Bessel, in Schum., 'Jahrb. für' 1839, s. 51; probably four
millions of miles daily, in a relative velocity of at the least 3,336,000 miles,
or more than couble the velocity of revolution of the Earth in her orbit
round the Sun.

This change of the entire solar system would remain unknown to us, if
the admirable exactness of our astronomical instruments of measurement,
and the advancement recently made in the art of observing, did not cause
our advance toward remote stars to be perceptible, like an approximation to
the objects of a distant shore in apparent motion. The proper motion of the
star 61 Cygni, for instance, is so considerable, that it has amounted to a
whole degree in the course of 700 years.

The amount or quantity of these alterations in the fixed stars (that is to
say, the changes in the relative position of self-luminous stars toward each
other), can be determined with a greater degree of certainty than we are able
to attach to the genetic explanation of the phenomenon. After taking into
consideration what is due to the precession of the equinoxes, and the
nutation of the earth's axis produced by the action of the Sun and Moon on
the spheroidal figure of our globe, and what may be ascribed to the
transmission of light, that is to say, to its aberration, and to the parallax

formed by the diametrically opposite position of the Earth in its course
round the Sun, we still find that there is a residual portion p 146 of the
annual motion of the fixed stars due to the translation of the whole solar
system in universal space, and to the true proper motion of the stars. The
difficult problem of numerically separating these two elements, the true and
the apparent motion, has been effected by the careful study of the direction
of the motion of certain individual stars, and by the consideration of the fact
that, if all the stars were in a state of absolute rest, they would appear
perspectively to recede from the point in space toward which the Sun was
directing its course. But the ultimate result of this investigation, confirmed
by the calculus of probabilities, is, that our solar system and the stars both
change their places in space. According to the admirable researches of
d'Argelander at Abo, who has extended and more perfectly developed the
work begun by William Herschel and Prevost, the Sun moves in the
direction of the constellation Hercules, and probably, from the combination
of the observations made of 537 stars, toward a point lying (at the equinox
of 1792.5) at 257ºdegrees 49.'7 R.A., and 28ºdegrees 49.'7 N.D. It is
extremely difficult, in investigations of this nature, to separate the absolute
from the relative motion, and to determine what is aloone owing to the solar
system.*

[footnote] *Regarding the motion of the solar system, according to
Bradley, Tobias Mayer, Lambert, Lalande, and William Herschel, see Arago
in the 'Annuaire', 1842, p. 388-399' Argelander, in Schum., 'Astron. Nachr .,
No. 363, 364, 398, and in the treatise 'Von der eigenen Bewegung des
Sonnensystems' (On the proper Motion of the Solar System), 1837, s. 43,
respecting Perseus as the central body of the whole stellar stratum, likewise
Otho Struve, in the 'Bull. de l'Acad. de St. Pétersb.', 1842, t. x., No. 9, p.
137-139. The last-named astronomer has found, by a mo4re recent
combination, 261ºdegrees 23' R.A.+37ºdegrees 36' Decl. for the direction of

the Sun's motion; and, taking the mean of his own results with that of
Argelander, we have, by a combination of 797 stars, the formula
259ºdegrees 9' R.A.+34ºdegrees 36' Decl.

If we consider the proper, and not the perspective motions of the stars, we
shall find many that appear to be distributed in groups, having an opposite
direction; and facts hitherto observed do not, at any rate, render it a
necessary assumption that all parts of our starry stratum, or the whole of the
stellar islands filling space, should move round one large unknown
luminous or non-luminous central body. The tendency of the human mind to
investigate ultimate and highest causes certainly inclines the intellectual
activity, no less than the imagination of mankind, to adopt such an
hypothesis. Even the Stagirite proclaimed that "every thing which is moved
must be referable to a motor, and that there would be no end to p 147 the
concatenation of causes if there were not one primordial immovable
morot."*

[footnote] *Aristot., 'de Cælo', iii., 2, p. 301, Bekker: 'Phys.', viii., t, p.
256.

This material taken from pages 147-203

COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1
by Alexander von Humboldt

Translated by E C Otte

from the 1858 Harper & Brothers edition of Cosmos, volume 1
—————————————————————————

The manifold translatory changes of the stars, not those produced by the
parallaxes at which they are seen from the changing position of the
spectator, but the true changes constantly going on in the regions of space,
afford us incontrovertible evidence of the 'dominion of the laws of
attraction' in the remotest regions of space, beyond the limits of our solar
system. The existence of these laws is revealed to us by many phenomena,
as, for instance, by the motion of double stars, and by the amount of
retarded or accelerated motion in different parts of their elliptic orbits.
Human inquiry need no longer pursue this subject in the domain of vague
conjecture, or amid the undefined analogies of the ideal world; for even
here the progress made in the method of astronomical observations and
calculations has enabled astronomy to take up its position on a firm basis. It
is not only the discovery of the astounding numbers of double and multiple
stars revolving round a center of gravity lying 'without' their system (2800
such systems having been discovered up to 1837), but rather the extension
of our knowledge regarding the fundamental forces of the whole material
world, and the proofs we have obtained of the universal empire of the laws
of attraction, that must be ranked among the most brilliant discoveries of
the age. The periods of revolution of colored stars present the greatest
differences; thus, in some instances, the period extends to 43 years, as in πpi
of Corona, and in others to several thousands,, as in 66 of Cetus, 38 of
Gemini, and 100 of Pisces. Since Herschel's measurements in 1782, the
satellite of the nearest star in the triple system of [Greek letter] of Cancer
has completed more than one entire revolution. By a skillful combination of
the altered distances and angles of position,* the elements of these orbits
may be found, conclusions drawn regarding the absolute distance of the
double stars from the Earth, and comparisons made between their mass and
that of the Sun.

[footnote] *Savary, in the 'Connaissance des Tems', 1830, p. 56 and 163.
Encke, 'Berl. Jahrb.', 1832, s. 253, etc. Arago, in the 'Annuaire' 1834, p.
260, 295. John Herschel, in the 'Memoirs of the Astronom. Soc.', vol. v., p.
171.

Whether, however, here and in our solar system, quantity of matter is the
only standard of the amount of attractive force, or whether 'specific' forces
of attraction proportionate to the mass may not at the same time come into
operation, as Bessel was the first to conjecture, are questions p 148 whose
practical solution must be left to future ages.*

[footnote] * Bessel, 'Untersuchung. des Theils der planetarischen
Storungen, welche aus der Bewegung der Sonne entstchen' (An
Investigation of the portion of the Planetary Disturbances depending on the
motion of the Sun) in 'Abh. der Berl. Akad. der Wissensch.', 1824 (Mathem.
Classe), s. 2-6. The question has been raised by John Tobias Mayer, in
'Comment. Soc. Reg. Gotting.', 1804-1808, vol. xvi., p. 31-68.

When we compare our Sun with the other fixed stars, that is, with other
self-luminous Suns in the lenticular starry stratum of which our system
forms a part, we find, at least in the case of some, that channels are opened
to us, which may lead, at all events, to an 'approximate' and limited
knowledge of their relative distances, volumes, and masses, and of the
velocities of their translatory motion. If we assume the distance of Uranus
from the Sun to be nineteen times that of the Earth, that is to say, nineteen
times as great as that of the Sun from the Earth, the central body of our
planetary system will be 11,900 times the distance of Uranus from the star
'a' in the constellation Centaur, almost 31,300 from 61 Cygni, and 41,600
from Vega in the constellation Lyra. The comparison of the volume of the

Sun with that of the fixed stars of the first magnitude is dependent upon the
apparent diameter of the latter bodies — an extremely undertain optical
element. If even we assume, with Herschel, that the apparent diameter of
Arcturus is only a tenth part of a second, it still follows that the true
diameter of this star is eleven times greater than that of the Sun.*

[footnote] *'Philos. Trans.' for 1803, p. 225. Arago, in the 'Annuaire',
1842, p. 375. In order to obtain a clearer idea of the distances ascribed in a
rather earlier part of the text to the fixed stars, let us assume that the Earth is
a distance of one foot from the Sun; Uranus is then 19 feet, and Vega Lyrae
is 158 geographical miles from it.

The distance of the star 61 Cygni, made known by Bessel, has led
approximately to a knowledge of the quantity of matter contained in this
body as a double star. Notwithstanding that, since Bradley's observations,
the portion of the apparent orbit traversed by this star is not sufficiently
great to admit of our arriving with perfect exactness at the true orbit nd the
major axis of this star, it has been conjectured with much probability by the
great Konigsberg astronomer,* "that the mass of this double star can not be
very considerably larger or smaller than half of the mass of the Sun."

[footnote] *Bessel, in Schum., 'Jahrb.', 1839, s. 53.

This result is from actual measurement. The analogies deduced from the
relatively larger mass of those planets in our solar system that are attended
by satellites, and from the fact that Struve has discovered six times more
double stars among p 194 the brighter than among the telescopic fixed stars,
have led other astronomers to conjecture that the average mass of the larger
number of the binary stars exceeds the mass of the Sun.*

[footnote] *Mädler, 'Astron.', s. 476; also in Schum, 'Jahrb.', 1839, s. 95.

We are, however, far from having arrived at general results regarding this
subject. Our Sun, according to Argenlander, belongs, with reference to
proper motion in space, to the class of rapidly-moving fixed stars.

The aspect of the starry heavens, the relative position of stars and
nebullae, the distribution of their luminous masses, the picturesque beauty,
if I may so express myself, of the whole firmament, depend in the course of
ages conjointly upon the proper motion of the stars and nebulae, the
translation of our solar system in space, the appearance of new stars, and
the disappearance or sudden diminution in the intensity of the light of
others, and lastly and specially, on the changes which the Earth's axis
experiences from the attraction of the Sun and Moon. The beautiful stars in
the constellation of the Centaur and the Southern Cross will at some future
time be visible in our northern latitudes, while other stars, as Sirius and the
stars in the Belt of Orion, will in their turn disappear below the horizon. The
places of the North Pole will successively be indicated by the stars ß beta
and a alpha Cephei, and ∂ delta Cygni, until after a period of 12,000 years,
Vega in Lyra will shine forth as the brightest of all possible pole stars.
These data give us some idea of the extent of the motions which, divided
into infinitely small portions of time, proceed without intermission in the
great chronometer of the universe. If for a moment we could yield to the
power of fancy, and imagine the acuteness of our visual organs to be made
equal with the extremest bounds of telescopic vision, and bring together
that which is now divided by long periods of time, the apparent rest that
reigns in space would suddenly disappear. We should see the countless host
of fixed stars moving in thronged groups in different directions; nebulae
wandering through space, and becoming condensed and dissolved like
cosmical clouds; the vail of the Milky Way separated and broken up in

many parts, and 'motion' ruling supreme in every portion of the vault of
heave, even as on the Earth's surface, where we see it unfolded in the germ,
the leaf, and the blossom, the organisms of the vegetable world. The
celebrated Spanish botanist Cavanilles was the first who entertained the
idea of "seeing grass grow," and he directed the horizontal micrometer
threads of a powerfully magnifying glass at one time to p 150 the apex of
the shoot of a bambusa, and at another on the rapidly-growing stem of an
American aloe ('Agave Americana', precisely as the astronomer places his
cross of net-work against a culminating star. In the collective life of
physical nature, in the organic as in the sidereal world, all things that have
been, that are, and will be, are alike dependent on motion.

The breaking up of the Milky Way, of which I have just spoken, requires
special notice. William Herschel, our safe and admirable guide to this
portion of the regions of space, has discovered by his star-guagings that the
telescopic breadth of the Milky Way extends from six to seven degrees
beyond what is indicated by our astronomical maps and by the extent of the
sidereal radiance visible to the naked eye.*

[footnote] *Sir William Herschel, in the 'Philos. Transact.' for 1817, Part
ii p. 438.

The two brilliant nodes in which the branches of the zone unite, in the
region of Cepheus and Cassiopeia, and in the vicinity of Scorpio and
Sagittarius, appear to exercise a powerful attraction on the contiguous stars;
in the most brilliant part, however between beta and [Greek symbol] Cygni,
one half of the 330,000 stars that have been discovered in a breadth of 5
degrees are directed toward one side, and the remainder to the other. It is in
this part that Herschel supposes the layer to be broken up.*

[footnote] *Arago, in the 'Annuaire', 1842, p. 569

The number of telescopic stars in the Milky Way uninterrupted by any
nebulae is estimated at 18 millions. In order, I will not say, to realize the
greatness of this number, but, at any rate, to compare it with something
analogous, I will call attention to the fact that there are not in the whole
heavens more than about 8000 stars between the first and the sixth
magnitudes, visible to the naked eye. The barren astonishment excited by
numbers and dimensions in space, when not considered with reference to
applications engaging the mental and perceptive powers of man, is
awakened in both extremes of the universe, in the celestial bodies as in the
minutest animalcules.*

[footnote] *Sir John Herschel, in a letter from Feldhuysen, dated Jan.
13th, 1836. Nicholl, 'Architecture of the Heavens', 1838, p. 22. (See, also,
some separate notices by Sir William Herschel on the starless space which
separates us by a great distance from the Milky Way, in the 'Philos.
Transact.' for 1817, Part ii., p. 328.)

A cubic inch of the polishing slate of Bilin contains, according to
Ehrenberg, 40,000 millions of the silicious shells of Galionellae.

The stellar Milky Way, in the region of which, according to Argelander's
admirable observations, the brightest stars of the firmament appear to be
congregated, is almost at right angles p 151 with another Milky Way,
composed of nebulae. The former constitutes, according to Sir John
Herschel's views, an annulus, that is to say, an independent zone, somewhat
remote from our lenticular-shaped starry stratum, and similar to Saturn's

ring. Our planetary system lies in an eccentric direction, nearer to the region
of the Cross than to the diametrically opposite point, Cassiopeia.*

[footnote] *Sir John Herschel, 'Astronom.', 624; likewise in his
'Observations on Nebulae and Clusters of Stars' ('Phil. Transact.', 1833, Part
ii., p. 479, fig. 25): "We have here a brother system, bearing a real physical
resemblance and strong analogy of structure to our own."

An imperfectly seen nebulous spot, discovered by Messier in 1774,
appeared to present a remarkable similarity to the form of our starry stratum
and the divided ring of our Milky Way.*

[footnote] *Sir William Herschel, in the 'Phil. Trans.' for 1785, Part i., p.
257. Sir John Herschel, 'Astron.', 616. ("The 'nebulous' region of the
heavens forms 'a nebulous Milky Way', composed of distinct nebulae, as the
other of stars." The same observation was made in a letter he addressed to
me in March, 1829.)

The Milky Way composed of nebulae does not belong to our starry
stratum, but surrounds it at a great distance without being physically
connected with it, passing almost in the form of a large cross through the
dense nebulae of Virgo, especially in the northern wing, through Comae
Berenicis, Ursa Major, Andromeda's girdle, and Pisces Boreales. It probably
intersects the stellar Milky Way in Cassiopeia, and connects its dreary poles
(rendered starless from the attractive forces by which stellar bodies are
made to agglomerate into groups) in the least dense portion of the starry
stratum.

We see from these considerations that our starry cluster, which bears
traces in its projecting branches of having been subject in the course of time
to various metamorphoses, and evinces a tendency to dissolve and separate,
owing to secondary centers of attraction — is surrounded by two rings, one
of which, the nebulous zone, is very remote, while the other is nearer, and
composed of stars alone. The latter, which we generally term the Milky
Way, is composed of nebulous stars, averaging from the tenth to the
eleventh degree of magnitude,* but appearing, when considered
individually, of very different magnitudes, while isolated starry clusters
(starry swarms) almost always exhibit throughout a character of great
uniformity in magnitude and brilliancy.

[footnote] *Sir John Herschel, 'Astron.', 585.

In whatever part the vault of heaven has been pierced by powerful and
far-penetrating telescopic instruments, stars or luminous nebulae are every
where discoverable, the former, in p 152 some cases, not exceeding the
twentieth or twenty-fourth degree of telescopic magnitude. A portion of the
nebulous vapor would probably be found resolvable into stars by more
powerful optical instruments. As the retina retains a less vivid impression of
separate than of infinitely near luminous points, less strongly marked
photometric relations are excited in the latter case, as Arago has recently
shown.*

[footnote] *Arago, in the 'Annuaire', 1842, p. 282-285, 409-411, and 439-
442.

The definite or amorphous cosmical vapor so universally diffused, and
which generates heat through condensation, probably modifies the

transparency of the universal atmosphere, and diminishes that uniform
intensity of light which, according to Halley and Olbers, should arise, if
every point throughout the depths of space were filled by an infinite series
of stars.*

[footnote] *Olbers, on the transparency of celestial space, in Bode's
'Jahrb.', 1826, s. 110-121.

The assumption of such a distribution in space is, however, at variance
with observation, which shows us large starless regions of space, 'openings'
in the heavens, as William Herschel terms them — one, four degrees in
width, in Scorpio, and another in Serpentarius. In the vicinity of both, near
their margin, we find unresolvable nebulae, of which that on the western
edge of the opening Scorpio is one of the most richly thronged of the
clusters of small stars by which the firmament is adorned. Herschel ascribes
these openings or starless regions to the attractive and agglomerative
forcesof the marginal groups.*

[footnote] *"An opening in the heavens," William Herschel, in the 'Phil.
Trans.' for 1785, vol. lxxv., Part i., p. 256. Le Francais Lalande, in the
'Connaiss. des Tems pour l'An.' VIII., p. 383. Arago, in the 'Annuaire', 1842,
p. 425.

"They are parts of our starry stratum," says he, with his usual graceful
animation of style, "that have experienced great devastation from time." If
we picture to ourselves the telescopic stars lying behind one another as a
starry canopy spread over the vault of heaven, these starless regions in
Scorpio and Serpentarius may, I think, be regarded as tubes through which
we may look into the remotest depths of space. Other stars may certainly lie

in those parts where the strata forming the canopy are interrupted, but these
are unattainable by our instruments. The aspect of fiery meteors had led the
ancients likewise to the idea of clefts or openings ('chasmata') in the vault
of heaven. These openings were, however, only regarded as transient, while
the reason of their being luminous and fiery, instead of obscure, was
supposed to be owing to the p 153 translucent illuminated ether which lay
beyond them.*

[footnote] *Aristot., 'Meteor.', ii.,, 5, 1. Seneca, 'Natur. Quaest.', i., 14, 2.
"Coelum discessisse," in Cic., 'de Divin.', i., 43.

Derham, and even Huygens, did not appear disinclined to explain in a
similar manner the mild radiance of the nebulae.*

[footnote] *Arago, in the 'Annuaire', 1842, p. 429.

When we compare the stars of the first magnitude, which, on an average,
are certainly the nearest to us, with the non-nebulous telescopic stars, and
further, when we compare the nebulous stars with unresolvable nebulae, for
instance, with the nebula in Andromeda, or even with the so-called
planetary nebulous vapor, a fact is made manifest to us by the consideration
of the varying distances and the boundlessness of space, which shows the
world of phenomena, and that which constitutes its causal reality, to be
dependent upon the 'propagation of light'. The velocity of this propagation
is according to Struve's most recent investigations, 166,072 geographical
miles in a second, consequently almost a million of times greater than the
velocity of sound. According to the measurements of Maclear, Bessel, and
Struve, of the parallaxes and distances of three fixed stars of very unequal
magnitudes ('a' Centauri, 16 Cygni, and 'a' Lyrae), a ray of light requires

respectively 3, 9 1/4, and 12 years to reach us from these three bodies. In
the short but memorable period between 1572 and 1604, from the time of
Cornelius Gemma and Tycho Brahe to that of Kepler, three new stars
suddenly appeared in Cassiopeia and Cygnus, and in the foot of
Serpentarius. A similar phenomenon exhibited itself at intervals in 1670, in
the constellation Vulpis. In recent times, even since 1837, Sir John Herschel
has observed, at the Cape of Good Hope, the brilliant star [Greek symbol]
in Argo increase in splendor from the second to the first magnitude.*

[footnote] *In December, 1837, Sir John Herschel saw the star [Greek
symbol] Argo, which till that time appeared as of the second magnitude, and
liable to no change, rapidly increase till it became of the first magnitude. In
January, 1838, the intensity of its light was equal to that of 'a' Centauri.
According to our latest information, Maclear in March, 1843, found it as
bright as Canopus; and even 'a' Crucis looked faint by [Greek symbol]
Argo.

These events in the universe belong, however, with reference to their
historical reality, to other periods of time than those in which the
phenomena of light are first revealed to the inhabitants of the Earth: they
reach us like the voices of the past. It has been truly said, that with our large
and powerful telescopic instruments we penetrate alike through the
boundaries of time and space: we measure the former through the latter, for
in the course of an p 154 hour a ray of light traverses over a space of 592
millions of miles. While according to the theogony of Hesiod, the
dimensions of the universe were supposed to be expressed by the time
occupied by bodies in falling to the ground ("the brazen anvil was not more
than nine days and nine nights in falling from heaven to earth"), the elder
Herschel was of opinion* that light required almost two millions of years to

pass to the Earth from the remotest luminous vapor reached by his forty-
foot reflector.

[footnote] *"Hence it follows that the rays of light of the remotest
nebulae must have been almost two millions of years on their way, and that
consequently, so many years ago, this object must already have had an
existence in the sidereal heaven, in order to send out those rays by which
we now perceive it." William Herschel, in the 'Phil. Trans.' for 1802, p. 498.
John Herschel, 'Astron.', 590. Arago, in the 'Annuaire', 1842, p. 334, 359,
and 382-385.

Much, therefore, has vanished long before it is rendered visible to us —
much that we see was once differently arranged from what it now appears.
The aspect of the starry heavens presents us with the spectacle of that which
is only apparently simultaneous, and however much we may endeavor, by
the aid of optical instruments, to bring the mildly-radiant vapor of nebulous
masses or the faintly-glimmering starry clusters nearer, and diminish the
thousands of years interposed between us and them, that serve as a criterion
of their distance, it still remains more than probable, from the knowledge
we possess of the velocity of the transmission of luminous rays, that the
light of remote heavenly bodies presents us with the most ancient
perceptible evidence of the existence of matter. It is thus that the reflective
mind of man is led from simple premises to rise to those exalted heights of
nature, where in the light-illumined realms of space, "myriads of worlds are
bursting into life like the grass of the night."*

[fotnote] *From my brother's beautiful sonnet "Freiheit und Gesetz."
(Wilhelm von Humboldt, 'Gesammelte Werke', bd. iv., s. 358, No. 25.)

From the regions of celestial forms, the domain of Uranus, we will now
descend to the more contracted sphere of terrestrial forces — to the interior
of the Earth itself. A mysterious chain links together both classes of
phenomena. According to the ancient signification of the Titanic myth,* the
powers of organic life, that is to say, the great order of nature, depend upon
the combined action of heaven and earth.

[footnote] *Otfried Muller, 'Prolegomena', s. 373.

If we suppose that the Earth, like all the other planets, primordially
belonged, according to its origin, to the central body, the Sun, and to the
solar atmosphere that has been separated into nebulous p 155 rings, the
same connection with this continguous Sun, as well as with all the remote
suns that shine in the firmament, is still revealed through the phenomena of
light and radiating heat. The difference in the degree of these actions must
not lead the physicist, in his delineation of nature, to forget the connection
and the common empire of similar forces in the universe. A small fraction
of telluric heat is derived from the regions of universal space in which our
planetary system is moving, whose temperature (which according to
Fourier, is almost equal to our mean icy polar heat) is the result of the
combined radiation of all the stars. The causes that more powerfully excite
the light of the Sun in the atmosphere and in the upper strata of our air, that
give rise to heat-engendering electric and magnetic currents, and awaken
and genially vivify the vital spark in organic structures on the earth's
surface, must be reserved for the subject of our future consideration.

As we purpose for the present to confine ourselves exclusively within the
telluric sphere of nature, it will be expedient to cast a preliminary glance
over the relations in space of solids and fluids, the form of the Earth, its
mean density, and the partial distribution of this density in the interior of

our planet, its temperature and its electro-magnetic tension. From the
consideration of these relations in space, and of the forces inherent in
matter, we shall pass to the reaction of the interior on the exterior of our
globe; and to the special consideration of a universally distributed natural
power — subterranean heat; to the phenomena of earthquakes, exhibited in
unequally expanded circles of commotion, which are not referable to the
action of dynamic laws alone; to the springing forth of hot wells; and, lastly,
to the more powerful actions of volcanic processes. The crust of the Earth,
which may scarcely have been perceptibly elevated by the sudden and
repeated, or almost uninterrupted shocks by which it has been moved from
below, undergoes, nevertheless, great changes in the course of centuries in
the relations of the elevation of solid portions, when compared with the
surface of the liquid parts, and even in the form of the bottom of the sea. In
this manner simultaneous temporary or permanent fissures are opened, by
which the interior of the Earth is brought in contact with the external
atmosphere. Molten masses, rising from an unknown depth, flow in narrow
streams along the declivity of mountains, rushing impetuously onward, or
moving slowly and gently, until the fiery source is quenched in the midst of
exhalations, and the lava becomes incrusted, as it were, by p 156 the
solidification of its outer surface. New masses of rocks are thus formed
before our eyes, while the older ones are in their turn converted into other
forms by the greater or lesser agency of Platonic forces. Even where no
disruption takes place the crystalline moleculres are displaced, combining
to form bodies of denser texture. The water presents structures of a totally
different nature, as, for instance, concretions of animal and vegetable
remains, of earthy, calcareous, or aluminous precipitates, agglomerations of
finely-pulverized mineral bodies, covered with layers of the silicious
shields of infusoria, and with transported soils containing the bones of fossil
animal forms of a more ancient world. The study of the strata which are so
differently formed and arranged before our eyes, and of all that has been so

variously dislocated, conforted, and upheaved, by mutual compression and
volcanic force, leads the reflective observer, by simple analogies, to draw a
comparison between the present and an age that has long passed. It is by a
combination of actual phenomena, by an ideal enlargement of relations in
space, and of the amount of active forces, that we are able to advance into
the long sought and indefinitely anticipated domain of geognosy, which has
only within the last half century been based on the solid foundation of
scientific deduction.

It has been acutely remarked, "that notwithstanding our continual
employment of large telescopes, we are less acquainted with the exterior
than with the interior of other planets, excepting, perhaps, our own
satellite." They have been weighed, and their volume measured; and their
mass and density are becoming known with constantly-increasing
exactness; thanks to the progress made in astronomical observation and
calculation. Their physical character is, however, hidden in obscurity, for it
is only in our own globe that we can be brought in immediate contact with
all the elements of organic and inorganic creation. The diversity of the most
heterogenous substances, their admixtures and metamorphoses, and the
ever-changing play of the forces called into action, afford to the human
mind both nourishment and enjoyment, and open an immeasurable field of
observation, from which the intellectual activity of man derives a great
portion of its grandeur and power. The world of perceptive phenomena is
reflected in the depths of the ideal world, and the richness of nature and the
mass of all that admits of classification gradually become the objects of
inductive reasoning.

I would here allude to the advantage, of which I have already p 157
spoken, possessed by that portion of physical science whose origin is
familiar to us, and is connected with our earthly existence. The physical
description of celestial bodies from the remotely-glimmering nebulae with

their suns, to the central body of our own system, is limited, as we have
seen, to general conceptions of the volume and quantity of matter. No
manifestation of vital activity is there presented to our senses. It is only
from analogies, frequently from purely ideal combinations, that we hazard
conjectures on the specific elements of matter, or on their various
modifications in the different planetary bodies. But the physical knowledge
of the heterogeneous nature of matter, its chemical differences, the regular
forms in which its molecules combine together, whether in crystals or
granules; its relations to the deflected or decomposed waves of light by
which it is penetrated; to radiating, transmitted, or polarized heat; and to the
brilliant or invisible, but not, on that account, less active phenomena of
electro-magnetism — all this inexhaustible treasure, by which the
enjoyment of the contemplation of nature is so much heightened, is
dependent on the surface of the planet which we inhabit, and more on its
solid than on its liquid parts. I have already remarked how greatly the study
of natural objects and forces, and the infinite diversity of the sources they
open for our consideration, strengthen the mental activity, and call into
action every manifestation of intellectual progress. These relations require,
however, as little comment as that concatenation of causes by which
particular nations are permitted to enjoy a superiority over others in the
exercise of a material power derived from their command of a portion of
these elementary forces of nature.

If, on the one hand, it were necessary to indicate the difference existing
between the nature of our knowledge of the Earth and of that of the celestial
regions and their contents, I am no less desirous, on the other hand, to draw
attention to the limited boundaries of that portion of spacefrom which we
derive all our knowledge of the heterogeneous character of matter. This has
been somewhat inappropriately termed the Earth's crust; it includes the
strata most contiguous to the upper surface of our planet, and which have
been laid open before us by deep fissure-like valleys, or by the labors of

man, in the bores and shafts formed by miners. These labors* do not extend
beyond a vertical depth of somewhat more than 2000 feet (about one third
of a geographical mile) below the p 159 level of the sea, and consequently
only about 1/9800th of the Earth's radius.

[footnote] *In speaking of the greatest depths within the Earth reached by
human labor, we must recollect that there is a difference between the
'absolute depth' (that is to say, the depth below the Earth's surface at that
point) and the 'relative depth' (or that beneath the level of the sea). The
greatest relative depth that man has hitherto reached is probably the bore at
the new salt-works at Minden, in Prussia: in June, 1814, it was exactly 1993
feet, the absolute depth being 2231 feet. The temperature of the water at the
bottom was 98 degrees F., which assuming the mean temperature of the air
at 49.3 degrees gives an augmentation of temperature of 1 degree for every
54 feet. The absolute depth of the Artesian well of Grenelle, near Paris, is
only 1795 feet. According to the account of the missionary Imbert, the fire-
springs, "Ho-tsing." of the Chinese, which are sunk to obtain [carbureted]
hydrogen gas for salt-boiling, far exceed our Artesian springs in depth. In
the Chinese province of Szu-tschuan these fire-springs are very commonly
of the depth of more than 2000 feet; indeed, at Tseu-lieu-tsing (the place of
continual flow) there is a Ho-tsing which, in the year 1812, was found to be
3197 feet deep. (Humboldt, 'Asie Centrale', t. ii., p. 521 and 525. 'Annales
de l'Association de la Propagation de la Foi', 1829, No. 16, p. 369.)

[footnote continues] The relative depth reached at Mount Massi, in
Tuscany, south of Volterra, amounts, according to Matteuci, to only 1253
feet. The boring at the new salt-works near Minden is probably of about the
same relative depth as the coal-mine at Apendale, near Newcastle-under-
Lyme, in Staffordshire, where men work 725 yards below the surface of the
earth. (Thomas Smith, 'Miner's Guide', 1836, p. 160.) Unfortunately, I do

not know the exact height of its mouth above the level of the sea. The
relative depth of the Monk-wearmouth mine, near Newcastle, is only 1496
feet. (Phillips, in the 'Philos. Mag.', vol. v., 1834, p. 446.) That of the Liege
coal-mine, 'l'Esperance' at Seraing, is, according to M. Gernaert, Ingenieur
des Mines, 1223 feet in depth. The works of greatest absolute depth that
have ever been formed are for the most part situated in such elevated plains
or valleys that they either do not descend so low as the level of the sea, or at
most reach very little below it. Thus the Eselchacht, at Kuttenberg, in
Bohemia, a mine which can not now be worked, had the enormous absolute
depth of 3778 feet. (Fr. A. Schmidt, 'Berggestze der oter Mon.', abth. i., bd.
i., s. xxxii.) Also, at St. Daniel and at Geish, on the Rorerbubel, in the
'Landgericht' (or provincial district) of Kitzbuhl, there were, in the sixteenth
century, excavations of 3107 feet. The plans of the works of the Rorerbubel
are still preserved. (See Joseph von Sperges, 'Tyroler Bergwerksgeschichte',
s. 121. Compare, also, Humboldt, 'Gutachten uber √∫erantreibung des
Meissner Stollens in die Freiberger Erzrevier', printed in Herder, 'uber
Herantreibung des Meissner Stollens in die Freiberger Erzrevier', printed in
Herder, 'uber den jetz begonnenen Erbstollen', 1838, s. cxxiv.) We may
presume that the knowledge of the extraordinary depth of the Rorerbuhel
reached England at an early period, for I find it remarked in Gilbert, 'de
Magnete', that men have penetrated 2400 or even 3000 feet into the crust of
the Earth. ("Exigua videtur terrae portio, quae unquam hominibus spectanda
emerget aut eruitur; cum profundinus in ejus viscera, ultra efflorescentis
extremitatis corruptelam, aut propter aquas in magnis fodin, tanquam per
venas scaturientesaut propter seris salubrioris ad vitam operariorum
sustinendam necessarii defectum, aut propter ingentex sumptus ad tantos
labores exantlandos, multasque difficultates, ad profundiores terrz' partes
penetrre non possumus; adeo ut quadrigentas aut [quod rarissime]
quingentas orgyas in quibusdam metallis descendisse, stupendus omnibus

videatur connatus." — Guilielmi Gilberti, Colcestrensis, 'de Magnete
Physiologia nova'. Lond., 1600, p. 40.)

[footnote continues] The absolute depth of the mines in the Saxon
Erzgebirge, near Freiburg, are: in the Thurmhofer mines, 1944 feet; in the
Honenbirker mines, 1827 feet; the relative depths are only 677 and 277 feet,
if, in order to calculate the elevation of the mine's mouth above the level of
the sea, we regard the elevation of Freiburg as determined by Reich's recent
observations to be 1269 feet. The absolute depth of the celebrated mine of
Joachimsthal, in Bohemia (Verkreuzung des Jung Hauer Zechen-und
Andreasganges), is full 2120 feet; so that, as Von Dechen's measurements
show that its surface is about 2388 feet above the level of the sea, it follows
that the excavations have not as yet reached that point. In the Harz, the
Samson mine at Andreasberg has an absolute depth of 2197 feet. In what
was formerly Spanish America, I know of no mine deeper than the
Valenciana, near Guanaxuato (Mexico), where I found the absolute depth of
the Planes de San Bernardo to be 1686 feet; but these planes are 5960 feet
above the level of the sea. If we compare the depth of the old Kuttenberger
mine (a depth greater than the height of our Brocken, and only 200 feet less
than that of Vesuvius) with the loftiest structures that the hands of man have
erected (with the Pyramid of Cheops and with the Cathedral of Strasburg),
we find that they stand in the ratio of eight to one. In this note I have
collected all the certain information I could find regarding the greatest
absolute and relative depths of mines and borings. In descending eastward
from Jerusalem toward the Dead Sea, a view presents itself to the eye,
which, according to our present hypsometrical knowledge of the surface of
our planet, is unrivaled in any country; as we approach the open ravine
through which the Jordan takes its course, we tread, with the open sky
above us, on rocks which, according to the barometric measurements of
Berton and Russegger are 1385 feet below the level of the Mediterranean.
(Humboldt, 'Asie Centrale', th. ii., p. 323.)

The crystalline masses that have been erupted from active volcanoes, and
are generally similar to the rocks on the upper surface, have come from
depths which, although not accurately determined, must certainly be sixty
times greater than those to which human labor has been enabled to
penetrate. We are able to give in numbers the depth of the shaft where the
strata of coal, after penetrating a certain way, rise again at a distance that
admits of being accurately defined by measurements. These dips show that
the carboniferous strata, together with the fossil organic remains which they
contain, must lie, as, for instance, in Belgium, more than five or six
thousand feet* below the present level p 160 of the sea, and that the
calcareous and the curved strata of the Devonian basin penetrate twice that
depth.

[footnote] *Basin-shaped curved strata, which dip and reappear at
measureable distances, although their deepest portions are beyond the reach
of the miner, afford sensible evidence of the nature of the earth's crust at
great depths below its surface. Testimony of this kind possesses,
consequently, a great geognostic interest. I am indebted to that excellent
geognosist, Von Dechen, for the following observations. "The depth of the
coal basin of Liege, at Mont St. Gilles, which I, in conjunction with our
friend Von Oeynhausen, have ascertained to be 3890 feet below the surface,
extends 3464 feet below the surface of the sea, for the absolute height of
Mont St. Gilles certainly does not much exceed 400 feet; the coal basin of
Mons is fully 1865 feet deeper. But all these depths are trifling compared
with those which are presented by the coal strata of Saar-Revier
(Saarbrucken). I have found after repeated examinations, that the lowest
coal stratum which is known in the neighborhood of Duttweiler, near
Bettingen, northeast of Saarlouis, must descend to depths of 20,682 and
22,015 feet (or 3.6 geographical miles) below the level of the sea." This
result exceeds, by more than 8000 feet, the assumption made in the text

regarding the basin of the Devonian strata. This coal-field is therefore sunk
as far below the surface of the sea as Chimborazo is elevated above it — at
a depth at which the Earth's temperature must be as high as 435ºdegrees F.
Hence, from the highest pinnacles of the Himalaya to the lowest basins
containing the vegetation of an earlier world, there is a vertical distance of
about 48,000 feet, or of the 435th part of the Earth's radius.

If we compare these subterranean basins with the summits of montains
that have hitherto been considered as the most elevated portions of the
raised crust of the Earth, we obtain a distance of 37,000 feet (about seven
miles), that is, about the 1/524th of the Earth's radius. These, therefore,
would be the limits of vertical depth and of the superposition of mineral
strata to which geognostical inquiry could penetrate, even if the general
elevation of the upper surface of the earth were equal to the height of the
Dhawalagigi in the Himalaya, or of the Sorata in Bolivia. All that lies at a
greater depth below the level of the sea than the shafts or the basins of
which I have spoken, the limits to which man's labors have penetrated, or
than the depths to which the sea has in some few instances been sounded
(Sir James Ross was unable to find bottom with 27,600 feet of line), is as
much unknown to us as the interior of the other planets of our solar system.
We only know the mass of the whole Earth and its mean density by
comparing it with the open strata, which alone are accessible to us. In the
interior of the Earth, where all knowledge of its chemical and mineralogical
character fails, we are again limited to as pure conjecture, as in the remotest
bodies that revolve round the Sun. We can determine nothing with certainty
regarding the depth at which the geological strata must be supposed to be in
state of softening or of liquid fusion, of the cavities occupied by elastic
vapor, of the condition of fluids when heated under an enormous pressure,
or of the law of the increase p 161 of density from the upper surface to the
center of the Earth.

The consideration of the increase of heat with the increase of depth
toward the interior of our planet, and of the reaction of the interior on the
external crust, leads us to the long series of volcanic phenomena. These
elastic forces are manifested in earthquakes, eruptions of gas, hot wells,
mud volcanoes and lava currents from craters of eruption and even in
producing alterations in the level of the sea.*

[footnote] * [See Daubeney 'On Volcanoes', 2d edit., 3848, p. 539, etc.,
on the so called 'mud volcanoes', and the reasons advanced in favor of
adopting the term "salses" to designate these phenomena.] — Tr.

Large plains and variously indented continents are raised or sunk, lands
are separated from seas, and the ocean itself, which is permeated by hot and
cold currents, coagulates at both poles, converting water into dense masses
of rock, which are either stratified and fixed, or broken up into floating
banks. The boundaries of sea and land, of fluids and solids, are thus
variously and frequently changed. Plains have undergone oscillatory
movements, being alternately elevated and depressed. After the elevation of
continents, mountain chains were raised upon long fissures, mostly parallel,
and in that case, probably cotemporaneous; and salt lakes and inland seas,
long inhabited by the same creatures, were forcibly separated, the fossil
remains of shells and zoophytes still giving evidence of their original
connection. Thus, in following phenomena in their mutual dependence, we
are led from the consideration of the forces acting in the interior of the
Earth to those which cause eruptions on its surface, and by the pressure of
elastic vapors give rise to burning streams of lava that flow from open
fissures.

The same powers that raised the chains of the Andes and the Hiimalaya
to the regions of perpetual snow, have occasioned new compositions and

new textures in the rocky masses, and have altered the strata which had
been previously deposited from fluids impregnated with organic substances.
We here trace the series of formations, divided and superposed according to
their age, and depending upon the changes of configuration of the surface,
the dynamic relations of upheaving forces, and the chemical action of
vapors issuing from the fissures.

The form and distribution of continents, that is to say, of that solid
portion of the Earth's surface which is suited to the luxurious development
of vegetable life, are associated by intimate connection and reciprocal
action with the encircling p 162 sea in which organic life is almost entirely
limited to the animal world. The liquid element is again covered by the
atmosphere, an aërial ocean in which the mountain chains and high plains
of the dry land rise like shoals, occasioning a variety of currents and
changes of temperature, collecting vapor from the region of clouds, and
distributing life and motion by the action of the streams of water which
flow from their declivities.

While the geography of plants and animals depends on these intricate
relations of the distribution of sea and land, the configuration of the surface,
and the direction of isothermal lines (or zones of equal mean annual heat),
we find that the case is totally different when we consider the human race
— the last and noblest subject in a physical description of the globe. The
characteristic differences in races, and their relative numerical distribution
over the Earth's surface, are conditions affected not by natural relations
alone, but at the same time and specially, by the progress of civilization,
and by moral and intellectual cultivation on which depends the political
superiority that distinguishes national progress. Some few races, clinging,
as it were, to the soil, are supplanted and ruined by the dangerous vicinity
of others more civilized than themselves, until scarce a trace of their
existence remains. Other races, again, not the strongest in numbers, traverse

the liquid element, and thus become the first to acquire, although late, a
geographical knowledge of at least the maritime lands of the whole surface
of our globe, from pole to pole.

I have thus, before we enter on the individual characters of that portion of
the delineation of nature which includes the sphere of telluric phenomena,
shown generally in what manner the consideration of the form of the Earth
and the incessant action of electro-magnetism and subterranean heat may
enable us to embrace in one view the relations of horizontal expansion and
elevation on the Earth's surface, the geognostic type of formations, the
domain of the ocean (of the liquid portions of the Earth), the atmosphere
with its meteorological processes, the geographical distribution of plants
and animals, and, finally, the physical gradations of the human race, which
is, exclusively and every where, susceptible of intellectual culture. This
unity of contemplation presupposes a connection of phenomena according
to their internal combination. A mere tabular arrangement of these facts
would not fulfill the object I have proposed to myself, and would not satisfy
that requirement for cosmical presentation awakened in me by the p 163
aspect of nature in my journeyings by sea and land, by the careful study of
forms and forces, and by a vivid impression of the unity of nature in the
midst of the most varied portions of the Earth. In the rapid advance of all
branches of physical science, much that is deficient in this attempt will,
perhaps, at no remote period, be corrected and rendered more perfect, for it
belongs to the history of the development of knowledge that portions which
have long stood isolated become gradually connected, and subject to higher
laws. I only indicate the empirical path in which I and many others of
similar pursuits with myself are advancing, full of expectation that, as Plato
tells us Socrates once desired, "Nature may be interpreted by reason
alone."*

[footnote] *Plato, 'Phaedo', p. 97. (Arist., 'Metaph.', p. 985.) compare
Hegel, 'Philosophie der Geschichte', 1840, s. 16.

The delineation of the principal characteristics of telluric phenomena
must begin with the form of our planet and its relations in space. Here too,
we may say that it is not only the mineralogical character of rocks, whether
they are crystalline, granular, or densely fossiliferous, but the geometrical
form of the Earth itself, which indicates the mode of its origin, and is, in
fact, its history. An elliptical spheroid of revolution gives evidence of
having once been a soft or fluid mass. Thus the Earth's compression
constitutes one of the most ancient geognostic events, as every attentive
reader of the book of nature can easily discern; and an analogous fact is
presented in the case of the Moon, the perpetual direction of whose axes
toward the Earth, that is to say, the increased accumulation of matter on that
half of the Moon which is turned toward us, determines the relations of the
periods of rotation and revolution, and is probably contemporaneous with
the earliest epoch in the formative history of this satellite. The mathematical
figure of the Earth is that which it would have were its surface covered
entirely by water in a state of rest; and it is this assumed form to which all
geodesical measurements of degrees refer. This mathematical surface is
different from that true physical surface which is affected by all the
accidents and inequalities of the solid parts.*

[footnote] *Bessel, 'Allgemeine Betrachtungen uber Gradmessungen
nach astronomisch-geodätischen Arbeiten', at the conclusion of Bessel and
Baeyer, 'Gradmessung in Ostpreussen', s. 427. Regarding the accumulation
of matter on the side of the Moon turned toward us (a subject noticed in an
earlier part of the text), see Laplace, 'Expos. du Syst. du Monde', p. 308.

The whole figure of the Earth is determined when we know the amount
of the p 164 compression at the poles and the equatorial diameter; in order,
however, to obtain a perfect representation of its form it is necessary to
have measurements in two directions, perpendicular to one another.

Eleven measurements of degrees (or determinations of the curvature of
the
Earth's surface in different parts), of which nine only belong to the
present century, have made us acquainted with the size of our globe, which
Pliny names "a point in the immeasurable universe."*

[footnote] *Plin., ii., 68. Seneca, 'Nat. Quaest., Praef., c. ii. "El mundo
espoco" (the Earth is small and narrow), writes Columbus from Jamaica to
Queen Isabella on the 7th of July, 1503: not because he entertained the
philosophic views of the aforesaid Romans, but because it appeared
advantageous to him to maintain that the journey from Spain was not long,
if, as he observes, "we seek the east from the west." Compare my 'Examen
Crit. de l'Hist. de la Geogr. du 15 me Siecle', t.i., p. 83, and t. ii., p. 327,
where I have shown that the opinion maintained by Delisle, Freret, and
Gosselin, that the excessive differences in the statements regarding the
Earth's circumference, found in the writings of the Greeks, are only
apparent, and dependent on different values being attached to the stadia,
was put forward as early as 1495 by Jaime Ferrer, in a proposition regarding
the determination of the line of demarkation of the papal dominions.

If these measurements do not always accord in the curvatures of different
meridians under the same degree of latitude, this very circumstance speaks
in favor of the exactness of the instruments and the methods employed, and
of the accuracy and the fidelity to nature of these partial results. The
conclusion to be drawn from the increase of forces of attraction (in the
direction from the equator to the poles) with respect to the figure of a planet
is dependent on the distribution of density in its interior. Newton, from
theoretical principles, and perhaps likewise prompted by Cassini's
discovery, previously to 1666, of the compression of Jupiter,* determined,

in his immortal work, 'Philosophiae Naturalis Principia', that the
compression of the Earth, as a homogeneous mass, was 1/230th.

[footnote] *Brewster, 'Life of Sir Isaac Newton', 1831, p. 162. "The
discovery of the spheroidal form of Jupiter by Cassini had probably directed
the attention of Newton to the determination of its cause, and consequently,
to the investigation of the true figure of the Earth." Although Cassini did not
announce the amount of the compression of Jupiter (1/15th) till 1691
('Anciens Memoires de l'Acad. des Sciences', t. ii., p. 108), yet we know
from Lalande ('Astron.', 3me ed., t. iii., p. 335) that Moraldi possessed some
printed sheets of a Latin work, "On the Spots of the Planets," commenced
by Cassini, from which it was obvious that he was aware of the
compression of Jupiter before the year 1666, and therefore at least twenty-
one years before the publication of Newton's 'Principia'.

Actual mesurements, p 165 made by the aid of new and more perfect
analysis, have, however, shown that the compression of the poles of the
terrestrial spheroid, when the density of the strata is regarded as increasing
toward the center, is very nearly 1/300th.

Three methods have been employed to investigate the curvature of the
Earth's surface, viz., measurements of degrees, oscillations of the
pendulum, and observations of the inequalities in the Moon's orbit. The first
is a direct geometrical and astronomical method, while in the other two we
determine from accurately observed movements the amount of the forces
which occasion those movements, and from these forces we arrive at the
cause from whence they have originated, viz., the compression of our
terrestrial spheroid. In this part of my delineation of nature, contrary to my
usual practice, I have instanced methods because their accuracy affords a
striking illustration of the intimate connection existing among the forms and

forces of natural phenomena, and also because their application has given
occasion to improvements in the exactness of instruments (as those
employed in the measurements of space) in optical and chronological
observations; to greater perfection in the fundamental branches of
astronomy and mechanics in respect to lunar motion and to the resistance
experienced by the oscillations of the pendulum; and to the discovery of
new and hitherto untrodden paths of analysis. With the exception of the
investigations of the parallax of stars, which led to the discovery of
aberration and nutation, the history of science presents no problem in which
the object attained — the knowledge of the compression and of the irregular
form of our planet — is so far exceeded in importance by the incidental
gain which has accrued, through a long and weary course of investigation,
in the general furtherance and improvement of the mathematical and
astronomical sciences. The comparison of eleven measurements of degrees
(in which are included three extra-European, namely, the old Peruvian and
two East Indian) gives, according to the most strictly theoretical
requirements allowed for by Bessel,* a compression p 166 of 1/299th.

[footnote] *According to Bessel's examination of ten measurements of
degrees, in which the error discovered by Poissant in the calculation of the
French measurements is taken into consideration (Schumacher, 'Astron.
Nachr.', 1841, No. 438, s. 116), the semi-axis major of the elliptical
spheroid of revolution to which the irregular figure of the Earth most
closely approximates is 3,272,077.14 toises, or 20,924,774 feet; the semi-
axis minor, 3,261,159,83 toises, or 20,854,821 feet; and the amount of
compression or eccentricity 1/299.152d; the length of a mean degree of the
meridian, 57,013.109 toises, or 364,596 feet, with an error of + 2.8403
toises, or 18.16 feet, whence the length of a geographical mile is 3807.23
toises, or 6086.7 feet. Previous combinations of measurements of degrees
varied between 1/302d and 1/297th; thus Walbeck ('De Forma of

Magnitudine telluris in demensis arcubus Meridiani definiendis', 1819)
gives 1/30278th: Ed. Schmidt ('Lehrbuch der Mathem. und Phys.
Geographie', 1829, s. 5) gives 1/20742d, as the mean of seven measures.
Respecting the influence of great differences of longitude on the polar
compression, see 'Bibliotheque Universelle', t. xxxiii., p. 181, and t. xxxv.,
p. 50: likewise 'Connaissance des Tems', 1829, p. 290. From the lunar
inequalities alone, Laplace ('Exposition du Syst. du Monde', p. 229) found
it, by the older tables of Burg, to be 1/3245th; and subsequently, from the
lunar observations of Burckhardt and Bouvard, he fixed it at 1/299.1th
('Mecanique Celeste', t. v., p. 13 and 43).

In accordance with this, the polar radius is 10,938 toises (69,944 feet), or
about 11 1/2 miles, shorter than the equatorial radius of our terrestrial
spheroid. The excess at the equator in consequence of the curvature of the
upper surface of the globe amounts, consequently, in the direction of
gravitation, to somewhat more than 4 3/7th times the height of Mont Blanc,
or only 2 1/2 times the probable height of the summit of the Chawalagiri, in
the Himalaya chain. The lunar inequalities (perturbation in the moon's
latitude and longitude) give according to the last investigations of Laplace,
almost the same result for the ellipticity as the measurements of degrees,
viz., 1/299th. The results yielded by the oscillation of the pendulum give, on
the whole, a much greater amount of compression, viz., 1/288th.*

[footnote] *The oscillations of the pendulum give 1/288.7th as the
general result of Sabine's great expedition (1822 and 1823, from the equator
to 80 degrees north latitude); according to Freycinet, 1/286.2d, exclusive of
the experiments instituted at the Isle of France, Guam, and Mowi (Mawi);
according to Forster, 1/289.5th; according to Duperrey, 1/266.4th; and
according to Lutke ('Partie Nautique', 1836, p. 232), 1/270th, calculated
from eleven stations. On the other hand, Mathieu ('Connais. des Temps',

1816, p. 330) fixed the amount at 1/298.2d, from observations made
between Formentera and Dunkirk; and Biot, at 1/304th, from observations
between Formentera and the island of Ust. Compare Baily, 'Report on
Pendulum Experiments', in the 'Memoirs of the Royal Astronomical
Society', vol. vii., p. 96; also Borenius, in the 'Bulletin de l'Acad. de St.
Petersbourg', 1843, t. i., p. 25. The first proposal to apply the length of the
pendulum as a standard of measure, and to establish the third part of the
seconds pendulum (then supposed to be every where of equal length) as a
'pes horarius', or general measure, that might be recovered at any age and
by all nations, is to be found in Huygens's 'Horologium Oscillatorium',
1673, Prop. 25. A similar wish was afterward publicly expressed, in 1742,
on a monument erected at the equator by Bouguer, La Condamine, and
Godin. On the beautiful marble tablet which exists, as yet uninjured, in the
old Jesuits' College at Quito, I have myself read the inscription, 'Penduli
simplicis aequinoctialis unius minuti secundi archetypus, mensurae
naturalis exemplar, utinam universalis!' From an observation made by La
Condamine, in his 'Journal du Voyage a l'Equateur', 1751, p. 163, regarding
parts of the inscription that were not filled up, and a slight difference
between Bonguer and himself respecting the numbers, I was led to expect
that I should find considerable discrepancies between the marble tablet and
the inscription as it had been described in Paris; but, after a careful
comparison, I merely found two "ex arca graduum plusquam trium," and
the date of 1745 instead of 1742. The latter circumstance is singular,
because La Condamine returned to Europe in November, 1744, Bouguer in
June of the same year, and Godin had left South America in July, 1744. The
most necessary and useful amendment to the numbers on this inscription
would have been the astronomical longitude of Quito. (Humboldt, 'Recueil
d'Observ. Astron.', t. ii., p. 319-354.) Nouet's latitudes, engraved on
Egyptian monuments, offer a more recent example of the danger presented
by the grave perpetuation of false or careless results.

Galileo, who first observed when a boy (having, probably, suffered his
thoughts to wander from the service) that the height of the vaulted roof of a
church might be measured by the time of the vibration of the chandeliers
suspended at different altitudes, could hardly have anticipated that the
pendulum would one day be carried from pole to pole, in order to determine
the form of the Earth, or, rather, that the unequal density of the strata of the
Earth affects the length of the seconds pendulum by means of intricate
forces of local attraction, which are, however, almost regular in large tracts
of land. These geognostic relations of an instrument intended for the
measurement of time — this property of the pendulum, by which, like a
sounding line, it searches unknown depths, and reveals in volcanic islands,*
or in the declivity of elevated continental mountain chains,** dense masses
of basalt and melaphyre instead of cavities, render it difficult,
notwithstanding the admirable simplicity of the method, to arrive at any
great result regarding the figure of the Earth from observation of the
oscillations of the pendulum.

[footnote] *Respecting the augmented intensity of the attraction of
gravitation in volcanic islands (St. Helena, Ualan, Fernando de Noronha,
Isle of France, Guam, Mowe, and Galapagos), Rawak (Lutke, p. 240) being
an exception, probably in consequence of its proximity to the highland of
New Guinea, see Mathieu, in Delambre, 'Hist. de l'Astronomie, au 18me
Siecle', p. 701.

[footnote] **Numerous observations also show great irregularities in the
length of the pendulum in the midst of continents, and which are ascribed to
local attractions. (Delambre, 'Mesure de la Meridienne', t. iii., p. 548; Biot,
in the 'Mem. de l'Academie des Sciences', t. viii., 1829, p. 18 and 23.) In
passing over the South of France and Lombardy from west to east, we find
the minimum intensity of gravitation at Bordeaux; from thence it increases

rapidly as we advance eastward, through Figeac, Clermont-Ferrand, Milan,
and Padua; and in the last town we find that the intensity has attained its
maximum. The influence of the southern declivities of the Alps is not
merely t on the general size of their mass, but (much more), in the opinion
of Elie de Beaumont ('Rech. sur les Revol. de la Surface du Globe', 1830, p.
729), on the rocks of melaphyre and serpentine, which have elevated the
chain. On the declivity of Ararat, which with Caucasus may be said to lie in
the center of gravity of the old continent formed by Europe, Asia, and
Africa, the very exact pendulum experiments of Fedorow give indications,
not of subterranean cavities, but of dense volcanic masses. (Parrot, 'Reise
zum Ararat', bd. ii., s. 143.) In the geodesic operations of Carlini and Plana,
in Lombardy, differences ranging from 20" to 47".8 have been found
between direct observations of latitude and the results of these operations.
(See the instances of Andrate and Mondovi, and those of Milan and Padua,
in the 'Operations Geodes. et Astron. pour la Mesure d'un Arc du Parallele
Moyen', t. ii., p. 347; 'Effemeridi Astron. di Milano', 1842, p. 57.) The
latitude of Milan, deduced from that of Berne, according to the , is
45ºdegrees 27' 52", while, according to direct astronomical observations, it
is 45 degrees 27' 35". As the perturbations extend in the plain of Lombardy
to Parma, which is far south of the Po (Plana, 'Operat. Geod.', t. ii., p. 847),
it is probable that there are deflecting causes 'concealed beneath the soil of
the plain itself'. Struve has made similar experiments [with corresponding
results] in the most level parts of eastern Europe. (Schumacher, 'Astron.
Nachrichten', 1830, No. 164, s. 399.) Regarding the influence of dense
masses supposed to lie at a small depth, equal to the mean height of the
Alps, see the analytical expressions given by Hossard and Rozet, in the
'Comptes Rendus', t. xviii., 1844, p. 292, and compare them with Poisson,
'Traite de Mecanique' (2me ed., t. i., p. 482. The earliest observations on the
influence which different kinds of rocks exercise on the vibration of the
pendulum are those of Thomas Young, in the 'Philos. Transactions' for

1819, p. 70-96. In drawing conclusions regarding the Earth's curvature from
the length of the pendulum, we ought not to overlook the possibility that its
crust may have undergone a process of hardening previously to metallic and
dense basaltic masses having penetrated from great depths, through open
clefts, and approached near the surface.

In the astronomical part of the determination of degrees of latitude,
mountain chains, or the denser strata of the Earth, likewise exercise,
although in a less degree, an unfavorable influence on the measurement.

As the form of the Earth exerts a powerful influence on the motions of
other cosmical bodies, and especially on that of its own neighboring
satellite, a more perfect knowledge of the motion of the latter will enable us
reciprocally to draw an inference regarding the figure of the Earth. Thus, as
Laplace ably remarks,* "An astronomer, without leaving his observatory,
may, by a comparison of lunar theory with true observations, not only be
enabled to determine the form and size of the Earth, but also its distance
from the Sun and Moon — results that otherwise could only be arrived at
by long and arduous expeditions to the most remote parts of both
hemispheres."

[footnote] *Laplace, 'Expos. du Syst. du Monde', p. 231.

p 169 The compression which may be inferred from lunar inequalities
affords an advantage not yielded by individual measurements of degrees or
experiments with the pendulum, since it gives a mean amount which is
referable to the whole planet. The comparison of the Earth's compression
with the velocity of rotation shows, further, the increase of density from the
strata from the surface toward the center — an increase which a comparison

of the ratios of the axes of Jupiter and Saturn with their times of rotation
likewise shows to exist in these two large planets. Thus the knowledge of
the external form of planetary bodies leads us to draw conclusions
regarding their internal character.

The northern and southern hemispheres appear to present nearly the same
curvature under equal degrees of latitude, but, as has already been observed,
pendulum experiments and measurements of degrees yield such different
results for individual portions of the Earth's surface that no regular figure
can be given which would reconcile all the results hitherto obtained by this
method. the true figure of the Earth is to a regular figure as the uneven
surfaces of water in motion are on the even surface of water at rest.

When the Earth had been measured, it still had to be weighed. The
oscillations of the pendulum* and the plummet have here likewise served to
determine the mean density of the Earth, either in connection with
astronomical and geodetic operations, with the view of finding the
deflection of the plummet from a vertical line in the vicinity of a mountain,
or by a comparison of the length of the pendulum in a plain and on the
summit of an elevation, or, finally, by the employment of a torsion balance,
which may be considered as a horizontally vibrating pendulum for the
measurement of the relative density of neighbouring strata.

[footnote] *La Caille's pendulum measurements at the Cape of Good
Hope, which have been calculated with much care by Mathieu (Delambre,
'Hist. de l'Astron. au 18me Siecle', p. 479), give a compression of 1/284.4th;
but, from several comparisons of observations made in equal latitudes in the
two hemispheres (New Holland and the Malouines (Falkland Islands),
compared with Barcelona, New York, and Dunkirk), there is as yet no
reason for supposing that the mean compression of the southern hemisphere

is greater than that of the northern. (Biot, in the 'Mem. de l'Acad. des
Sciences', t. viii., 1829, p. 39-41.)

Of these three methods* the p 170 last is the most certain, since it is
independent of the difficult determination of the density of the mineral
masses of which the spherical segment of the mountain consists near which
the observations are made.

[footnote] *The three methods of observation give the following results:
(1.) by the deflection of the plumb-line in the proximity of the Shehallien
Mountain (Gaelic, Thichallin) in Perthshire, r.713, as determined by
Maskelyne, Hutton, and Playfair (1774-1776 and 1810), according to a
method that had been proposed by Newton; (2.) by pendulum vibrations on
mountains, 4.837 (Carlini's observations on Mount Cenis compared with
Biot's observations at Bordeaux, 'Effemer. Astron. di Milano', 1824, p. 184);
(3.) by the torsion balance used by Cavendish, with an apparatus originally
devised by Mitchell, 5.48 (according to Hutton's revision of the calculation,
5.32, and according to that of Eduard Schmidt, 5.52; 'Lehrbuch der Math.
Geographie', bd. i., s. 487); by the torsion balance, according to Reich, 5.44.
In the calculation of these experiments of Professor Reich, which have been
made with masterly accuracy, the original mean result was 5.43 (with a
probable error of only 0.0233), a result which, being increased by the
quantity by which the Earth's centrifugal force diminishes the force of
gravity for the latitude of Freiberg (50 degrees 55'), becomes changed to
5.44. The employment of cast iron instead of lead has not presented any
sensible difference, or none exceeding the limits of errors of observation,
hence disclosing no traces of magnetic influences. (Reich, 'Vrsuche uber die
mittlere Dichtigheit der Erde', 1838, s. 60, 62, and 66.) By the assumption
of too slight a degree of ellipticity of the Earth, and by the uncertainty of
the estimations regarding the density of rocks on its surface, the mean

density of the Earth, as deduced from experiments on and near mountains,
was found about one sixth smaller than it really is, namely, 4.761 (Laplace,
'Mecan. Celeste', t. v., p. 46), or 4.785. (Eduard Schmidt, 'Lehrb. der Math.
Geogr.', bd. i., 387 und 418.) On Halley's hypothesis of the Earth being a
hollow sphere (noticed in page 171), which was the germ of Franklin's ideas
concerning earthquakes, see 'Philos. Trans.' for the year 1693, vol. xvii., p.
563 ('On the Structure of the Internal Parts of the Earth, and the concave
habited 'Arch of the Shell'). Halley regarded it as more worthy of the
Creator "that the Earth, like a house of several stories, should be inhabited
both without and within. For light in the hollow sphere (p. 576) provision
might in some manner be contrived."

According to the most recent experiments of Reich, the result obtained is
5.44; that is to say, the mean density of the whole Earth is 5.44 times
greater than tht of pure water. As according to the nature of the
mineralogical strata constituting the dry continental part of the Earth's
surface, the mean density of this portion scarcely amounts to 2.7, and the
density of the dry and liquid surface conjointly to scarcely 1.6, it follows
that the elliptical unequally compressed layers of the interior must greatly
increase in density toward the center, either through pressure or owing to
the heterogeneous nature of the substances. Here again we see that the
vertical, as well as the horizontally vibrating pendulum, may justly be
termed a geognostical instrument.

The results obtained by the employment of an instrument of this kind
have led celebrated physicists, according to the difference of the hypothesis
from which they started, to adopt p 171 entirely opposite views regarding
the nature of the interior of the globe. It has been computed at what depths
liquid or even gaseous substances would, from the pressure of their own
superimposed strata, attain a density exceeding that of platinum or even

iridium; and in order that the compression which has been detrmined within
such narrow limits might be brought into harmony with the assumption of
simple and infinitely compressible matter, Leslie has ingeniously conceived
the nucleus of the world to be a hollow sphere, filled with an assumed
"imponderable matter, having an enormous force of expansion." These
venturesome and arbitrary conjectures have given rise, in wholly
unscientific circles, to still more fantastic notions. The hollow sphere has by
degrees been peopled with plants and animals, and two small subterranean
revolving planets — Pluto and Proserpine — were imaginatively supposed
to shed over it their mild light; as, however, it was further imagined that an
ever-uniform temperature reigned in these internal regions, the air, which
was made self-luminous by compression, might well render the planets of
this lower world unnecessary. Near the north pole, at 80 degrees latitude,
whence the polar light emanates, was an enormous opening, through which
a descent might be made into the hollow sphere, and Sir Humphrey Davy
and myself were even publicly and frequently invited by Captain Symmes
to enter upon this subterranean expedition: so powerful is the morbid
inclination of men to fill unknown spaces with shapes of wonder, totally
unmindful of the counter evidence furnished by well-attested facts and
universally acknowledged natural laws. Even the celebrated Halley, at the
end of the seventeenth century, hollowed out the Earth in his magnetic
speculations. Men were invited to believe that a subterranean freely-rotating
nucleus occasions by its position the diurnal and annual changes of
magnetic declination. It has thus been attempted in our own day, with
tedious solemnity, to clothe in a scientific garb the quaintly-devised fiction
of the humorous Holbert.*

[footnote] *[The work referred to, one of the wittiest productions of the
learned Norwegian satirist and dramatist Holberg, was written in Latin, and
first appeared under the following title: 'Nicolai Klimii iter subterraneum

novam telluris theoriam ac historiam quintae monarchi Nicolai Klimii iter
subterraneum novam telluris theoriam ac historiam quintae monarchi ad huc
nobis incognitae exhibens e bibliotheca b. Abelini. Hafniae et Lipsiae sunt.
Jac. Preuss', 1741. An admirable Danish translation of this learned but
severe satire on the institutions, morals, and manners of the inhabitants of
the upper Earth, appeared at Copenhagen in 1789, and was entitled 'Niels
Klim's underjordiske reise ocd Ludwig Holberg, oversal after den Latinske
original of Jens Baggesen'. Holberg, who studied for a time at Oxford, was
born at Bergen in 1685, and died in 1754 as Rector of the University of
Copenhagen.] — Tr.

p 172 The figure of the Earth and the amount of solidification (density)
which it has acquired are intimately connected with the forces by which it is
animated, in so far, at least, as they have been excited or awakened from
without, through its planetry position with reference to a luminous central
body. Compression, when considered as a consequence of centrifugal force
acting on a rotating mass, explains the earlier condition of fluidity of our
planet. During the solidification of this fluid, which is commonly
conjectured to have been gaseous and primordially heated to a very high
temperature, an enormous quantity of latent heat must have been liberated.
If the process of solidification began as Fourier conjectures, by radiation
from the cooling surface exposed to the atmosphere, the particles near the
center would have continued fluid and hot. As, after long emanation of heat
from the center toward the exterior, a stable condition of the temperature of
the Earth would at length be established, it has been assumed that with
increasing depth the subterranean heat likewise uninterruptedly increases.
The heat of the water which flows from deep borings (Artesian wells),
direct experiments regarding the temperature of rocks in mines, but, above
all, the volcanic activity of the Earth, shown by the flow of molten masses
from open fissures, afford unquestionable evidence of this increase for very

considerable depths from the upper strata. According to conclusions based
certainly upon mere analogies, this increase is probably much greater
toward the center.

That which has been learned by an ingenious analytic calculation,
expressly perfected for this class of investigations,* p 173 regarding the
motion of heat in homogeneous metallic spheroids, must be applied with
much caution to the actual character of our planet, considering our present
imperfect knowledge of the substances of which the Earth is composed, the
difference in the capacity of heat and in the conducting power of different
superimposed masses, and the chemical changes experienced by solid and
liquid masses from any enormous compression.

[footnote] *Here we must notice the admirable analytical labors of
Fourier, Biot, Laplace, Poisson, Duhamel, and Lame. In his 'Theorie
Mathematique de la Chaleur', 1835, p. 3, 428-430, 436, and 521-524 (see,
also, De la Rive's abstract in the 'Bibliotheque Universelle de Geneve',
Poisson has developed an hypothesis totally different from Fourier's view
('Theorie Analytique de la Chaleur'.) He denies the present fluid state of the
Earth's center; he believes that "in cooling by radiation to the medium
surrounding the Earth, the parts which were first solidified sunk, and that by
a double descending and ascending current, the great inequality was
lessened which would have taken place in a solid body cooling from the
surface." It seems more probable to this great geometer that the
solidification began in the parts lying nearest to the center: "the
phenomenon of the increase of heat with the depth does not extend to the
whole mass of the Earth, and is merely a consequence of the motion of our
planetary system in space, of which some parts are of a very different
temperature from others, in consequence of stellar heat (chaleur stellaire)."
Thus, according to Poisson, the warmth of the water of our Artesian wells is

merely that which has penetrated into the Earth from without; and the Earth
itself "might be regarded as in the same circumstances as a mass of rock
conveyed from the equator to the pole in so short a time as not to have
entirely cooled. The increase of temperature in such a block would not
extend to the central strata." The physical doubts which have reasonably
been entertained against this extraordinary cosmical view (which attributes
to the regions of space that which probably is more dependent on the first
transition of matter condensing from the gaseo-fluid into the solid state)
will be found collected in Poggendorf's 'Annalen', bd. xxxix., s 93-100.

It is with the greatest difficulty that our powers of comprehension can
conceive the boundary line which divides the fluid mass of the interior from
the hardened mineral masses of the external surface, or the gradual increase
of the solid strata, and the condition of semi-fluidity of the earthy
substances, these being conditions to which known laws of hydraulics can
only apply under considerable modifications. The Sun and Moon, which
cause the sea to ebb and flow, most probably also affect these subterranean
depths. We may suppose that the periodic elevations and depressions of the
molten mass under the already solidified strata must have caused
inequalities in the vaulted surface from the force of pressure. The amount
and action of such oscillations must, however, be small; and if the relative
position of the attracting cosmical bodies may here also excite "spring
tides," it is certainly not to these, but to more powerful internal forces, that
we must ascribe the movements that shake the Earth's surface. There are
groups of phenomena to whose existence it is necessary to draw attention,
in order to indicate the universality of the influence of the attraction of the
Sun and Moon on the external and internal conditions of the Earth, however
little we may be able to determine the quantity of this influence.

According to tolerably accordant experiments in Artesian wells, it has
been shown that the heat increases on an average about 1 degree for every
54.5 feet. If this increase can be reduced p 174 to arithmetical relations, it
will follow, as I have already observed,* that a stratum of granite would be
in a state of fusion at a depth of nearly twenty-one geographical miles, or
between four and five times the elevation of the highest summit of the
Hinalaya.

[footnote] *See the Introduction. This increase of temperature has been
found in the Puits de Grenelle, at Paris, at 58.3 feet; in the boring at the new
salt-works at Minden, almost 53.6; at Pregny, near Geneva, according to
Auguste de la Rive and Marcet, notwithstanding that the mouth of the
boring is 1609 feet above the level of the sea, it is also 53.6 feet. This
coincidence between the results of a method first proposed by Arago in the
year 1821 ('Annuaire du Bureau des Longitudes', 1835, p. 234), for three
different mines, of the absolute depths of 1794, 2231, and 725 feet
respectively, is remarkable. The two points on the Earth, lying at a small
vertical distance from each other, whose annual mean temperatures are most
accurately known, are probably at the spot on which the Paris Observatory
stands, and the Caves de l'Observatoire beneath it; the mean temperature of
the former is 51.5ºdegrees, and of the latter 53.3ºdegrees, the difference
being 1.8ºdegrees for 92 feet, or 1 degree for 51.77 feet. (Poisson, 'Theorie
Math. de la Chaleur', p. 415 and 462.) In the course of the last seventeen
years, from causes not yet perfectly understood, but probably not connected
with the actual temperature of the caves, the thermometer standing there has
risen very nearly 0.4 degrees. Although in Artesian wells there are
sometimes slight errors from the lateral permeation of water, these errors
are less injurious to the accuracy of conclusions than those resulting from
currents of cold air, which are almost always present in mines. The general
result of Reich's great work on the temperature of the mines in the Saxony

mining districts gives a somewhat slower increase of the terrestrial heat, or
1 degree to 76.3 feet. (Reich, 'Beob. uber die Temperatur des Gesteins in
verschielen en Tiefen', 1834, s. 134.) Phillips, however, found (Pogg.,
'Annalen', bd. xxxiv., s. 191), in a shaft of the coal-mine of Monk-
wearmouth, near Newcastle, in which, as I have already remarked,
excavations are going on at a depth of about 1500 feet below the level of
the sea, an increase of 1 degree to 59.06 feet, a result almost identical with
that found by Arago in the Puits de Grenell.

We must distinguish in our globe three different modes for the
transmission of heat. The first is periodic, and affects the temperature of the
terrestrial strata according as the heat penetrates from above downward or
from below upward, being influenced by the different positions of the Sun
and the seasons of the year. The second is likewise an effect of the Sun,
although extremely slow: a portion of the heat that has penetrated into the
equatorial regions moves in the interior of the globe toward the poles,
where it escapes into the atmosphere and the remoter regions of space. The
third mode of transmission is the slowest of all, and is derived from the
secular cooling of the globe, and from the small portion of the primitive
heat which is still being disengaged from the surface. p 175 This loss
experienced by the central heat must have been very considerable in the
earliest epochs of the Earth's revolutions, but within historical periods it has
hardly been appreciable by our instruments. The surface of the Earth is
therefore situated between the glowing heat of the inferior strata and the
universal regions of space, whose temperature is probably below the
freezing-point of mercury.

The periodic changes of temperature which have been occasioned on the
Earth's surface by the Sun's position and by meteorological processes, are
continued in its interior, although to a very inconsiderable depth. The slow

conducting power of the ground diminishes this loss of heat in the winter,
and is very favorable to deep-rooted trees. Points that lie at very different
depths on the same vertical line attain the maximum and minimum of the
imparted temperature at very different periods of time. The further they are
removed from the surface, the smaller is this difference between the
extremes. In the latitudes of our temperate zone (between 48 degrees and 52
degrees), the stratum of invariable temperature is at a depth of from 59 to
64 feet, and at half that depth the oscillations of the thermometer, from the
influence of the seasons, scarcely amount to half a degree. In tropical
climates this invariable stratum is only one foot below the surface, and this
fact has been ingeniously made use of by Boussingault to obtain a
convenient, and as he believes, certain determination of the mean
temperature of the air of different places.*

[footnote] *Boussingault, 'Sur la Profondeus a laquelle se trouve la
Couche de Temperature invariable, entre les Tropiques', in the 'Annales de
Chimie et de Physique', t. liii., 1833, p. 225-247.

This mean temperature of the air at a fixed point, or at a group of
contiguous points on the surface, is to a certain degree the fundamental
element of the climate and agricultural relations of a district; but the mean
temperature of the whole surface is very different from that of the globe
itself. The questions so often agitated, whether the mean temperature has
experienced any considerable differences in the course of centuries, whether
the climate of a country has deteriorated, and whether the winters have not
become milder and the summers cooler, can only be answered by means of
the thermometer; this instrument has, however, scarcely been invented more
than two centuries and a half, and its scientific application hardly dates back
120 years. The nature and novelty of the means interpose, therefore, very
narrow limits to our investigation regarding the temperature p 176 of the air.

It is quite otherwise, however, with the solution of the great problem of the
internal heat of the whole Earth. As we may judge of uniformity of
temperature from the unaltered time of vibration of a pendulum, so we may
also learn, from the unaltered rotatory velocity of the Earth, the amount of
stability in the mean temperature of our globe. This insight into the relations
between the 'length of the day' and the 'heat of the Earth' is the result of one
of the most brilliant applications of the knowledge we had long possessed
of the planet. The rotatory velocity of the Earth depends on its volume; and
since, by the gradual cooling of the mass by radiation, the axis of rotation
would become shorter, the rotatory velocity would necessarily increase, and
the length of the day diminish, with a decrease of the temperature. From the
comparison of the secular inequalities in the motions of the Moon with the
eclipses observed in ancient times, it follows that, since the time of
Hipparchus, that is, for full 2000 years, the length of the day has certainly
not diminished by the hundredth part of a second. The decrease of the mean
heat of the globe during a period of 2000 years has not, therefore, taking the
extremest limits, diminished as much as 1/306th of a degree of Fahrenheit.*

[footnote] *Laplace, 'Exp. du Syst. du Monde', p. 229 and 263;
'Mecanique Celeste', t. v., p. 18 and 72. It should be remarked that the
fraction 1/306th of a degree of Fahrenheit of the mercurial thermometer,
given in the text as the limit of the stability of the Earth's temperature since
the days of Hipparchus, rests on the assumption that the dilation of the
substances of which the Earth is composed is equal to that of glass, that is
to say, 1/18,000th for 1 degree. Regarding this hypothesis, see Arago in the
'Annuaire' for 1834, p. 177-190.

This invariability of form presupposes also a great invariability in the
distribution of relations of density in the interior of the globe. The
translatory movements, which occasion the eruptions of our present