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COSMOS:

A SKETCH

A PHYSICAL DESCKIPTION OF THE UNIVERSE.

ALEXANDER VON HUMBOLDT. / J^ ^ 7 - / ^ 6^

TaANSI.ATED FROU THE OEBOIAN,

BY E. 0. OTTE.

NatursQ vero rerum vis atque majestas in omnibus momentis fide caret, si quis modo
partes ejus ac non totam cornplectatur animo. — Plin., Hist. Nat, lib. vii., c. L

IN FOUR VOLUMES.

VOL. L

NEW YORK:
HARPER & BROTHERS, PUBLISHERS

329 & 331 PEARL STREET,
FRANKLIN SqVARE.

TRANSLATOR'S PREFACE.

I CAN not more appropriately introduce the Cosmos tliau
by presenting a brief sketch of the life of its illustrious au-
thor.* While the name of Alexander von Humboldt is fa-
miliar to every one, few, perhaps, are aware of the peculiar
circumstances of his scientific career and of the e:3ctent of his
labors in almost every department of physical knowledge. He
was bom 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 pu-
pil 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
borps, 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 oth-
er scientific pursuits, among which botany and the then re-
cent discovery of galvanism may be especially noticed. Bot-
any, 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 in-
struments which he afterward turned to so singularly excel-
lent an account.

The political disturbances of the civilized world at the close

* For the following remarks I am mainly indebted to the articles on
die Cosmos in the two leaduig Quarterly Reviews.

IV TRANSLATOR'S PREFACE.

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 posses-
sions 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 dia-
metrically 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 have in-
delibly 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 considera-
bly 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 govern-
ment. 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

TRANSLATOR S PREFACE. V

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 de-
voted 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 compre-
hends two distinct parts, the first of which treats of the in-
citements to the study of nature, afforded in descriptive poet-
ry, 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 him-
self 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 Na-

VI TRANSLATOR S PREFACE.

ture." Each of the three parts of the Cosmos is therefore, to
a certain extent, distinct in its object, and may he considered
complete in itself We can not better terminate this brief
notice than in the words of one of the most eminent philos
ophers of our own country, that, " should the conclusion cor-
respond (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 Alexan
der von Humboldt."

In venturing to appear before the English pubHc as the in
terpreter of " the great work of our age,''* I have been en-
couraged by the assistance of many kind literary and scientific
friends, and I gladly avail myself of this opportunity of ex-
pressing my deep obligations to Mr. Brooke, Dr. Day, Pro
fessor Edward Forbes, Mr. Hind, Mr. Glaisher, Dr. Percy, ai^d
Mr. Ronalds, for the valuable aid they have afforded me.

It would be scarcely right to conclude these remarks with-
out a reference to the translations that have preceded mine.
The translation executed by Mrs. Sabine is singularly accu-
rate and elegant. The other translation is remarkable fo/
the opposite quaHties, and may therefore be passed over in si-
lence. The present volumes differ from those of Mrs. Sabinp
in having all the foreign measures converted into correspond-
ing Enghsh 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 omit-
ting passages, sometimes amounting to pages, simply because
they might be deemed slightly obnoxious to our national prej-
udices.

* 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.

AUTHOB'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 cotemporaries 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 mygelf for many years — and apparently exclusively —
with separate branches of science, as, for instance, with de-
scriptive botany, geognosy, chemistry, astronomical determin-
ations 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 inter
course 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 illu*
gion. These special departments in the great dom^^ni of nat-

mi AUTHOR S PREFACE.

ural science are, moreover, capable of being reciprocally fruc-
tified by means of the appropriative forces by which they are
endowed. Descriptive botany, no longer confined to the nar-
row 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 over the
earth's surface, according to distance from the equator and ver-
tical elevation above the sea. It is further necessary to in-
vestigate the laws which regulate the differences of tempera-
ture and climate, and the meteorological processes of the at-
mosphere, before we can hope to explain the involved causes
of vegetable distribution ; and it is thus tffat 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 dis-
tricts 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 geog-
raphy has thus, by an extended and perhaps too boldly imag-
ined 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 difiiculties in the choice of the form under

AUTHOR S PREFACE. IX

which such a work must be presented, if it would aspire to
the honor of being regarded as a Hterary ccmposition. De-
scriptions 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 ob-
Fervation. 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 wliich the German public
have bestowed upon a small work bearing the title of Ansich-
ten 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 strong-
ly manifested, than by means of any thing which it could it-
self impart. In the work on the Cosmos on which I am now
engaged, I have endeavored to show, as in that entitled An-
sichten der Natur, that a certain degree of scientific com-
pleteness in the treatment of individual facts is not wholly
mcompatible 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 sci-
ence, 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 phys-
ical 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.

X AUTHOR S PREFACE.

of those portions of my discourses which have been preserved
by the industry of certain attentive auditors. With the ex-
ception 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 pres-
ent condition of knowledge and opinions. Since the addi-
tions 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 con
tains 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 pic-
ture 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 re-
gard to the connection existing between generahties and spe-
cialities, while it moreover exemplifies, by the form and style
of the composition, the mode of treatment pursued in the se-
lection 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 na-
ture (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 spe-

AUTHOR S PREFACE XI

cial 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 au-
thorities from whence I derived my facts, with a view of afford-
ing 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, scat-
tered 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 inva-
riably preferred the repetition of the same w(^ds to any arbi-
traiy substitution of my own paraphrases. The much-con-
tested 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 occasion-
ally 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 dis-
coveries by which the age was characterized, I have been sim-
ply 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 dog-
matical modern opinions, and enter the free and fanciful do
main of earlier presentiments.

It has frequently been regarded as a subject of discouraging
consideration, that while purely literary products of intellect
ual activity are rooted in the depths of feeUng, and interwoven
with the creative force of imagination, all works treating of
empirical knowledge, and of the connection of natural phe-
nomena and physical laws, are subject to the most marked
modifications of form in the lapse of short periods of time, both

XU AUTHOR S PREFACE.

by the improvement in the instruments used, and by the con-
sequent expansion of the field of view opened to rational ob
servation, and that those scientific works which have, to use
a common expression, become mitiquated by the acquisition
of new funds of knowledge, are thus continually being con-
signed 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 addi-
tions 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 re-
gards 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 ani-
mation and exalted grandeur, and to trace the stable amid the
vacillating, ever-recurring alternation of physical metamorph-
oe«s, will not be wholly disregarded even at a future age.
Pottdam, Nov., 1844.

CONTENTS OF VOL I.

The. Translator's Preface iii

The Author's Preface vii

Summary xv

INTRODUCTION.

The Results of the Study of Physical Phenomena 23

Th» different Epochs of the Contemplation of the external World . 24
The different Degrees of Enjoyment presented by the Contempla-
tion 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 cele-
brated Mountams in the World, considered with Reference to the

Effect produced on the Mind of the Observer 27-3'?

The Impressions awakened by the Aspect of tropical Regions ... 35
The more accurate Knowledge of the Physical Forces of the Uni-
verse, acquired by the Inhabitants of a small Section of the tem-
perate 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 Observa-
tion 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, 61

Signification of the Word Cosmos 68—70

The Domain embraced by Cosmography 71

Empiricism and Experiments 74

The Process of Reason and Induction 77

XIV COP^TENTS.

GENERAL REVIEW OF NATURAL PHENOMENA.

Pag«

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 Ill

Zodiacal Light 137

Translatory Motion of the Solar System #.145

The Milky Way 150

Starless Openings 152

Terrestrial Phenomena , 1 54

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 217

Hot Springs 221

Salses : 224

Volcanoes 227

^ocks 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

SUMMARY.

Translator's Preface.

Author's Preface.

Vol. I.

GENERAL SUMMARY OF THE CONTENTS.

Introduction. — Reflections on the different Degrees of Enjoyment pre-
sented 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
anity 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 effect produced by the individual character of a locality. Effect
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 o^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 firma-
ment and all the forms of vegetation — p. 23-33.

Tendency toward the investigation of the causes of physical phenom
ena. Erroneous views of the character of natural forces arising from
an imperfect mode of observation or of induction. The crude accu
mulation of physical dogmas transmitted from one century to another.
Their diffusion among the higher classes. Scientific physics are asso-
ciated with another and a deep-rooted system of untried and misunder
stood experimental positions. Investigation of natural laws. Appre
hension 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 na
ture must necessarily be weakened by a study of its domain. Advant-
ages of general views which impart an exalted and solemn character
to natural science. The possibility of separating generalities from
specialities. Examples drawn from astronomy, recent optical discov
eries, physical geognosy, and the geography of plants. Practicabil
ity of the study of physical cosmography — p. 33-54. Misunderstood
popular knowledge, confounding cosmography with a mere encyclope-
dic enumeration of natural sciences. Necessity for a simultaneous re-
gard 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; recip-
rocal connection existing between thought and speech — p. 54-5C

The notes to p. 28-33. Comparative hypsometrical data of the eleva-
tions of the Dhawalagiri, Jawahir, Chimborazo, iEtna (according to the
measurement of Sir John Herschel), the Swiss Alps, &c. — p. 28. Rarity

XVi SUMMARY OF THE CONTENTS.

of palms and ferns in the Himalaya Mountains — p. 29. European v-^-
etable 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 50-78

Subjects embraced by the study of the Cosmos or of physical cosmog
raphy. Separation of other kindred studies — p. 56-62. The urano-
logical portion of the Cosmos is more simple than the telluric ; the im-
possibility of ascertaining the diversity of matter simplifies the study
of the mechanism of the heavens. Origin of the word Cosmos, its sig-
nification of adornment and order of the universe. The existing can
not be absolutely separated in our contemplation of nature from the
future. Histoiy of the world and description of the world — p. 62-73.
Attempts to embrace the multiplicity of the phenomena of the Cos-
mos in the unity of thought and under the form of a purely rational
combination. Natural philosophy, which preceded all exact observa-
tion in antiquity, is a natural, but not unfrequently ill-directed, eftbrt
of reason. Two forms of abstraction rule the whole mass of knowl-
edge, viz.: the auantitdtive, relative determinations according to num-
ber and magnitude, and qualitative, material characters. Means of
submitting phenomena to calculation. Atoms, mechanical methods of
construction. Figurative representations ; mythical conception of im-
ponderable 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 empir-
ical laws; their gradual simplification and generalization. Arrange
ment of the facts discovered in accordance with leading ideas. The
treasure of empirical contemplation, collected through ages, is in no dan
ger 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 Koafiog and mnndus.']

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 {to irdv) in the celestial and terrestrial
spheres. Form and course of the representation. It begins with the
depths of space, of which we know little beyond the existence of
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 terres-
trial spheroid, surrounded by air and water, and, finally, proceeds to
the consideration of the form of our planet, its temperature and mag-
netic 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.
Distribittion of matter, which is partially conglomerated into rotating

SUMMARY OF THE CONTENTS. XVll

and circling heavenly bodies of very diflferent 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 re-
ciprocal connection of all phenomena. /

I. Celestial Portion of the Cosmos Page 83-154

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

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

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

c. Material products which frequently accompany earthquakes. Gas
eous and aqueous springs. Salses and mud volcanoes Upheavals of
the soil by elastic forces — p. 217-528.

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.
Piienomena of contact. Fossiliferous strata ; their vertical arrangement.
The faunas and floras of an earlier woi-ld. Distribution of masses of
rock— p. 247-284.

f. Geognostical epochs, which are indicated by the mineralogical dif-
ference of rocks, have determined the distribution of solids and fluids
into continents and seas. Individual configuration of solids into hori-
zcintal expansion and vertical elevation. Relations of area. Articula-
tion. 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
efiects—p. 301-311.

' h. The atmosphere. Its chemical composition. Fluctuations in its
de nsity . Law of the direction of the winds. Mean temperature. Enu-
meration 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 pei'petual 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 grada-
tions 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 wag
conjectured at the close of the last century. Primary planets with Nep-
tune, Astrea, Hebe, Iris, and Flora, now constitute 16 ; secondary plan-
ets 18 ; myriads of comets of which many of the inner ones are inclosec?

XViU SUMMARY OF THE CONTENTS.

in the orbits of the planets ; a rotating ring (the zodiacal light) and me*
teoric stones, probably to be regarded as small cosmical bodies. The
telescopic planets, Vesta, Juno, Ceres, Fallas, 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. Dif-
ferences of absolute magnitude, density, period of revolution, eccentric-
ity, and inclination of the orbits. Tlie 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-—
J). 98 and note. Comets; the nucleus and tail; various forms and di-
rections of the emanations in conoidal envelopes, with more or less
dense walls. Several tails inclined toward the sun ; change of form of
the tail; its conjectured rotation. Nature of light. Occultations of the
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, obsei'ved height. Periodic return in streams; the November
stream and the stream of St. Lawrence. Chemical composition of me-
teoric asteroids — p. 130 and notes. Ring of zodiacal light. Limita
tion of the present solar atmosphere — p. 141 and note. Translatory
motion of the whole solar system — p. 145-149 and note. The exist-
ence 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 stai's ; openings in the stellar stra-
tum. Events in the universe ; the apparition of new stars. Propaga-
tion 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 meas-
urements of degrees, pendulum oscillations, and certain inequalities in
the moon's orbit. Mean density of the earth. The earth's crust, and
ttie depth to which we are able to penetrate — p. 159, 160, note. Three-
fold 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 magnet-
ic force on the earth's surface presented under three classes of phe«
nomena, namely, lines of equal force (isodynamic), equal inclination
(isoclinic), and equal deviation (isogenic). 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 observat

SUMMARY OP THE CONTENTS. XUC

tories 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 mere-
ly dynamic concussions or the upheaval of whole portions of the earth's
ci-ust, 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. Earth-
quakes. Extent of the circles of commotion and their gradual increase.
Whether there exists any connection between the changes in terres-
trial magnetism and the processes of the atmosphere. Noises, subter-
ranean thunder without any perceptible concussion. The rocks which
modify the propagation of the waves of concussion. Upheavals ; erup-
tion 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. Tempei*ature 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 eleva-
tion or among the detritus of their original structure. Permanent con-
nection 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. Height 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 coui'se, 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 ele-
vated above the level of the sea (the study of the geographical form
and outlines of the diflerent parts of the earth). Classification of rocks
according to the scale of the phenomena of structure and metamorpho-
sis, which are still passing before our eyes. Rocks of eruption, sedi
mentary rocks, changed (metamorphosed) rocks, conglomerates — con*
pound rocks are definite associations of oryctognostically simple fossils
There are four phases in the formative condition: rocka of eruption.

XX SUWMAKV OF THE CONTENTS.

endogenous ( granite, sienite, porphyry, greenstone, hypersthene, rock'
cuphotide, melapbyre, basalt, and phonolithe) ; sedimentary rocks (si-
lurian schist, coal measures, limestone, travertine, infusorial deposit);
metamorphosed rock, which contains also, together with the detritus
of the rocks of eniption and sedimentary rocks, the remains of gneiss,
mica schist, and more ancient metamoi-phic masses. Aggregate and
sandstone formations. The phenomenon of contact explained by the
artificial imitation of minerals. Effects of pressure and the various ra-
pidity of cooling. Origin of granular or saccharoidal marble, silicifica-
tion 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 sedimentaiy structures considered in their most simple
iud general characters ; silurian and devonian formations (formerly
Known as rocks of transition); the lower trias (mountain limestone,
coal measures, together with todtliegende and zechstein) ; the upper
trias (hunter sandstone, muschelkalk, and keuper) ; Jura limestone (lias
and oolite); freestone, lower and upper chalk, as the last of the flStz
strata, which begin with mountain limestone ; tertiary formations in
three divisions, which are designated by granular limestone, lignite,
ar.d south Apennine gravel — p. 269-278.

The faunas and floras of an earlier world, and their relations to exist-
ing 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
bunter sandstone. Lignite and coal measures (amber-tree). Deposition
of large masses of rock ; doubts regarding their origin — p. 285 and note

/. The knowledge of geognostic epochs — of the upheaval of mount-
ain 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 configura-
tion of the earth's surface. Existing areal relations of the solid to the
fluid differ considerably from those presented by the maps of the phys-
ical 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 exten-
sion (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 pyi-amidai
termination toward the south. Series of peninsulas. Valley-like form-
ation 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
oanter of gravity of the volume of the lauds upheaved above the level

SUMMARY OF THE CONTENTS. XXI

of the sea. The elevation of continents is still progressing slowly, and
is being compensated for at some definite points by a perceptible sink*
ing. All geognostic phenomena indicate a periodical alternation 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 aggrega-
tion and electricity, and in their relations of currents and temperature.
Depths of the ocean and of the atmosphere, the shoals of which consti
tute our highlands and mountain chains. The degree of heat at the
surface of the sea in different latitudes and in the lower strata. Tend-
ency of the sea to maintain the temperature of the surface in the strata
nearest to the atmosphere, in consequence of the mobility of its parti-
cles 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 gi-eatest saline contents. Thermic influence of the lower polar cur-
rent 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
cuiTents; 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, pres
sure, temperature, humidity, and electric tension. Relation of oxygen
to nitrogen ; amount of carbonic acid ; carbureted hydrogen ; ammo-
niacal vapors. Miasmata. 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 ref-
erence to the knowledge of many meteorological processes. Land and
sea winds, trade winds and monsoons — p. 311-317. Climatic distribu-
tion 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 iso-
thermal lines in a horizontal and vertical direction, on the earth's sur-
face 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 the 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 t«m-»
perature. 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 atnios«
phere 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. Difterence
between the southern and northern hemispheres. Thermal scales o/"

XXU SUMMARY OF THE CONTENTS.

cultivated plants, going down from the vanilla, cacoa, and musaceee, to
citrons and olives, and to vines yielding potable wines. The influence
which these scales exercise on the geographical distribution of culti-
vated plants. The favorable ripening and the immaturity of fruits are
essentially influenced by the difierence in the action of direct or scat-
tered light in a clear sky or in one overcast with mist. General sum-
mary 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 temper-
ature, which correspond to one degree of geographical latitude. Equal-
ity of the mean temperature of a mountain station, and of the polar dis-
tance of any point lying at the level of the sea. Decrease of tempera-
ture 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; hab-
itability of the elevated plateaux of Thibet — p. 331. Quantity of moist-
ure 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. Predetefmina
tion 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 equihbrium
in the atmospheric currents has been destroyed at some considerable
distance— p. 335-339.

i. Physical geography is not limited to elementary inorganic terres-
trial 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 diSusion 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. Geog-
raphy of plants and animals. Migrations of organisms in the ovum, or
by means of organs capable of spontaneous motion. Spheres of distri-
bution depending on climatic relations. Regions of vegetation, and
classification of the genera of animals. Isolated and social living plants
and animals. The character of floras and faunas 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 difierent
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 histoiy of mental activity, manifest a character of nation-
ality, although certain historical occurrences have been the means of
difflising idioms of the same family of languages among nations of wholly
different descent — p. 351-359.

INTRODUCTION.

REFLECTIONS ON THE DIFFERENT DEGREES OF ENJOYMENT PRE
SENTED TO US BY THE ASPECT OF NATURE AND THE STUDY OF HER

LAWS.

In attempting, after a long absence from my native coun-
try, 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 vi^eary
the mind of my reader by aphorisms consisting of mere gener-
alities clothed in dry and dogmatical forms. Undue concise-
ness 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 dehne
ated 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 mere-
ly in its bearings on the material wants of life, but in its gen-
eral influence on the intellectual advancement of mankind,
we find its noblest and most important result to be a knowl-
edge 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 intel-
lect, combined with the spirit of the age, in which are reflect-
ed 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 por-
tion 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 imag<^i of

24 COSMOS.

a Cosmos, or harmoniously ordered whole, which, dimly shad-
owed forth to the human mind in the primitive ages of the
world, is now fully revealed to the maturer intellect of man
kind 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 or
der that was proclaimed by the invariable and successive re-
appearance of the heavenly bodies, and by the progressive de-
velopment of organized beings ; while in the latter, this sense
of enjoyment springs from a definite knowledge of the phe-
nomena 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 in-
vestigation 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 ob-
servations, and substitutes induction and reasoning for con-
jecture 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 cf
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 inspira-
tion of the earliest ages, having by degrees lost their vague-
ness 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 dis-
similar in form and attributes ; one great whole (to rrav) an-
imated 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 mat-
ter, to determine with impartial justice what is due to the
discoveries of the past and to those of the present, and to an-
alyze the individual parts of natural phenomena without suo-
cumbing beneath the weight of the whole. Thus, and thus
alone, is it permitted to man, while mindful of the high de*-

tNTRODUCTION.

25

tmy of his race, to compreliend 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 pre-
sented to us in the contemplation of nature, we find that the
<irst place must be assigned to a sensation, which is wholly
independent of ^n 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 penetra-
ted 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 ev
ery 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 ex-
istence and the image of infinity revealed on every side, wheth-
er 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 enjoy-
ment, awakening impressions that are more vivid, better de-
fined, 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 na-
ture, 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 contempla-
tion 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 thi?
Vol. I.— B

26 COSMOS.

various sensations that derive their charm and peimanenc*
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 ;
Dr I would recall the deep valleys of the Cordilleras, where
the tall and slender palms pierce the leafy vail around them,
md waving on high their feathery and arrow-like branches,
'brm, as it were, " a forest above a forest ;"* or I would de-
scribe the summit of the Peak of TenerifFe, when a horizontal
layer of clouds, dazzling in whiteness, has separated the cone
)f 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 peace-
ful charm uniformly spread over the face of nature that moves
the heart, but rather the peculiar physiognomy and conforma-
tion of the land, the features of the landscape, the ever-vary-
ing 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
i 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 hap-
py illusion to believe that we receive from the external world
that with which we have ourselves invested it.

When far from our native country, after a long voyage, we
-.read for the first time the soil of a tropical land, we expe-
dience a certain feeling of surprise and gratification in recog-
nizing, in the rocks that surround us, the same inclined schis-
tose strata, and the same columnar basalt covered with cellu-
lar amygdaloids, that we had left in Europe, and whose iden-
tity of character, in latitudes so widely different, reminds us
that the solidification of the earth's crust is altogether inde-
pendent of climatic influences. But these rocky masses of
&3hist and of basalt are covered with vogetation of a character
with which we are unacquainted, and of a physiognomy wholly

* This expression is taken from a beautiful description of tropical
Ib^est scenery in Paul and Virginia, by Bernardin de Saint Pierre.

INTRODUCTION. 27

unknown, to us ; and it is then, amid the colossal and majestic
forms of an exotic flora, that we feel how wonderfully the flex-
ibility 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, thai
although the sight of a vegetation similar to that of our native
country mi^ht at first be most welcome to the eye, as the sweel
familiar sounds of our mother tongue are to the ear, we neV'
crtheless, by degrees, and almost imperceptibly, become famil
iarized with a new home and a new climate. As a true citi
'zen of the world, man every where habituates himself to tha'
which surrounds him ; yet fearful, as it were, of breaking tl ^
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 organiza*
tion, 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 land-
scape, and of every imposing scene in nature, depends so ma-
terially 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 emo-
tions produced ; and we can only trace their difl^erent sources
by analyzing the individuaUty of objects and the diversity of
forces.

The richest and most varied elements for pursuing an anal-
ysis of this nature present themselves to the eyes of the trav-
eler 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 con-
fines 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 sys*
tematic views, are not only suited to please the imagination,

2ft COSMOS.

but may also, when properly considered, indicate the grades
oi" the impressions of which I have spoken, from the uniform-
ity 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 Schreck-
horn,* or the Schneekoppe of Silesia on Mont Blanc, we should

* These comparisons are only approximative. The several eleva-
tions above the level of the sea are, in accurate numbers, as follows :

The Schneekoppe or Riesenkoppe, in Silesia, about 5270 feet, ac-
cording 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 TrigonomUriques en Suisse, 1840, p. 230.) Mount
Athos, 6775 feet, according to Captain Gaultier; Mount Pilatus, 7546
feet; Mount .ffitna, 10,871 feet, according to Captain Smyth; or io,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 (calcu-
lated by assuming the terrestrial refraction to be 0*076) ; the Schreck
horn, 12,383 feet ; the Jungfrau, 13,720 feet, according to Tralles ; Mont
Blanc, 15,775 feet, according to the different measurements considered
by Roger {Bibl. Univ., May, 1828, p. 24-53), 15,733 feet, according to
the measurements taken from Mount Columbier by Carlini in 1821, and
15,V48 feet, as measured by the Austrian engineers fi'ora Trelod and
the Glacier d'Ambin.

The actual height of the Swiss mountains fluctuates, according to
Eschman's observations, as much as 25 English feet, owing to the vary-
ing thickness of the stratum of snow that covers the summits. Chim-
borazo 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 determin-
ations of Blake and Webb, the elevation assigned to the Dhawalagiri
(or white mountain, from the Sanscrit dhawala, white, and giri, mount-
ain) can not be received with the same confidence as that of the Jawa-
hir, 25,749 feet, since the latter rests on a complete trigonometrical
mtjasurement (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 (Hum-
boldt, 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
Ji*' *-ney to the Boorendo Pass, 1840, vol. i., p. 143 and 311). Chimbo-
n-^o is spoken of in the text only as one of the highest summits of the
(jhain of the Andes ; for in the year 1827, the learned and highlj-gifted
traveler, Pentland, in his memorable expedition to Upper Peru (BtJivia),
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 highes
mountain in tbo Himadaya that has as yet been acciu'ately measured

INTRODUCTION. . 28

not have attained to the height of that great Colossus of the
Andes, the Chimborazo, whose height is twice that of Mount
^tna; 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. But although the mountains of India greatly sur-
pass the Cordilleras of South America by their astonishing el-
evation (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 does 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.* On the southern slope of the an-
cient Paropamisus, in the latitudes of 28° and 34°, nature no
longer displays the same abundance of tree-ferns and arbores-
cent grasses, hehconias and orchideous plants, which in tropic-

Thus Mont Blanc is 5646 feet below Chimborazo; Chimborazo, 3779
feet below the Sorata ; the Sorata, 549 feet below the Jawahir, and prob
ably 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 meas-
urement 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 re
ductions of the measurements.

[In the preceding note, taken from those appended to the Introduc-
tion 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.

* The absence of palms and tree-ferns on the temperate slopes of the
Himalaya is shown in Don's Flora Nepalensis, 1825i and in the remark-
able series of lithographs of Wallich's Flora Jndica, whose catalogue
contains the enormous number of 7683 Himalaya species, almost all
phanerogamic plants, which have as yet Ijeen but imperfectly classified.
In Nepaul (lat. 26P to 27^°) there has hitherto been observed only one
species of palm, Chama3rops martiana, Wall. (Plantce Asiat., lib. iii., p,
5, 211), which is found at the height of 5250 English feet above the leve
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 Ne-
paul, but is found on the mountains of Silhet, to the northwest of Cal-
cutta, in lat. 24^^ 50'. The Nepaul fern, Paranema cyathSides, Don,
formerly known as Sphaeroptera barbata, Wall. (^Plantce Asiat., lib. i.
p. 42, 48)y is, indeed, nearly related to Cyathea, a species of which 1
have seen in the South American Missions of Caripe, measuring 33 feet
■I height; this is not, however, properly speaking, a tree.

so COSMOS.

al 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 cov-
ered with vegetable forms almost similar to those which char-
acterize Europe and Northern Asia. The species are not
identical, but closely analogous in aspect and physiognomy, as,
for instance, the juniper, the alpine birch, the gentian, the
marsh parnassia, and the prickly species of Ribes.* The
chain of the Himalaya is also wanting in the imposing phe-
nomena 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 inte-
rior of our planet.

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 be-
gins at an elevation of 11,000 or 12,000 feet above the level
of the sea,t thus setting a limit to the development of organic

• 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, hb. 11, p.
510, Cas.), twenty- five oaks, four birches, two chestnuts, seven maples,
twelve willows, fourteen roses, three species of strawberry, seven spe-
cies of Alpine roses (rkododendra), 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° (see Carl von HQgel's Kaschmir, 1840, 2d pt.
249). Among the Coniferse, we find the Pinus deodwara, or deodara
(in Sanscrit, d4wa-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, PcBonia Emo-
di, Tulipa stellata; and, besides varieties of European genera peculiar
to these Indian mountains, true European species, as Leontodon tarax-
acum, Prunella vulgaris, Galium aparine, and Thlaspi arvense. The
heath mentioned by Saunders, jn Turner's Travels, and which had be^n
confounded with Calluna vulgaris, is an Andromeda, a fact of the great
est importance in the geography of Asiatic plants. If I have made use,
in this work, of the unphilosophical expressions of European genera,
European species, growing wild in Asia, &c., it has been in consequence
of the old botanical language, which, instead of the idea of a large dis-
semination, 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.

t On the southern declivity of the Himalaya, the limit of perpetual
•now is 12,978 feet above the level of the sea; on the northern decliv-
ity, or, -ather, on the peaks which rise above the Thibet, or Tartarian

INTRODUCTION. 3 J?

iife in a zone that is nearly 3000 feet lower than that to whict
it attains in the equinoctial region of the Cordilleras.

fJateau, this limit is at 16,625 feet from 30^° to 32° of latitude, whik
at the equator, iu the Audes of Quito, it is^5,790 feet. Such is the
result I have deduced from the combiuatiou 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 Chisnie et tU
Physique^ U iii., p. 303; t. xiv., p. 6^ 22, 50.) The greater elevation to
which the limit of perpetual snow recedes on the Tartarian dechvity
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 Cen
trale, t. iii., p. 281-326.) My opinion ou the ditFerence of height of
tlie snow-hne on the two sides of the Himalaya has the high authority
of Colebrooke iu its ^vor. He wrote to me in June, 1824, as follows:
*' I also find, from the data in my possession, tliat the elevation of the
line of perpetual snow is 13,000 feet. On the southern declivity, and
at latitude 31°, Webb's measurements give me 13,500 feet, consequently
500 feet more than the height deduced from Captain Hodgson's ob
servations. Gerard's measurements fully confirm your opinion iha-
the line of snow is higher on the northern than on the southern side.'
U was not until the present year (1840) that we obtained the complete
tnd collected journal of the brothers Gerard, published under the su
pervision of Mr. Lloyd. (Narrative of a Journey from Cawnpoor t
the Boorendo Pass, in the Himalaya, by Captain Alexander Gerard ant
John Gerard, edited by George Lloyd, vol. i., p. 291, 311, 320, 327, au(
;i41.) Many interesting details regarding some localities may be found
in ttie 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 At
gust, 1822. Unfortunately, however, these travelers always confoun' >
the elevation at which sporadic snow falls with the maximum of th
height that the snow-line attains on the Thibetian plateau. Captaiti
Gerard distinguishes between the summits tliat rise in the middle o
the plateau, where he states the elevatioi^ of the snow-line to be hi
♦ween 18,000 and 19,000 feet, and the northern slopes of the chain o
Uie Himalaya, which border on the defile of the Sutledge, and can n
liate but little heat, owing to the deep ravines with which they ar .
intersected. The elevation of the village of Tanguo is given at only
)300 feet, while that of the plateau surrounding the sacred lake of Mm
•lasa is 17,000 feet. Captain Gerard finds the snow-line 500 feet lowt j
on the northern slopes, where the chain of the Himalaya is broke i.
through, than toward the southern declivities facing Hindostan, and h t
':here estimates the line of perpetual snow at 15,000 feet. The moi i
striking differences are presented between the vegetation on the Thil
etian plateau and that cliaracteristic of the southern slopes ot the Hin
.ilaya. Ou 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 stiil
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 t.t
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 eleva
tion of upward of 17,000 feet, that is to say, 1280 feet above the lowej
iimito of the snow-liije at the equator, in the province of Quito. It is

82 cosivf ( s.

But the countries bordering on the equator possess anothei
advantage, to which sufficient attention has not hitherto been

very desirable that the mean elevation of the Thibetian plateau, whicb
I have estimated at only about 82(>0 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 vv^ho are accustomed to judge of tha
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 Geograph-
itchen Analyse der Karte von Inner Aden, 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 th'e 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 laud in Central Asia affords man all that is essential to the mainte-
nance 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 peqietual 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 IG^ and 17£° souih latitude. Tho
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 tl>e
barometrical observations of Victor Jacquemont, who fell an early sac-
rifice to his noble and unwearied ardor. (See bis Corresp<>ndance
pendant son Voyage dans Vhtde, 1828 a 1832, liv. 23, p. 2&a, 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. Oi»
the Kioubrong, 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.)

The same traveler says, " To whatever height we rise on the south-
ern declivity of the Himalaya, the climate retains the same character,
and the same division of the seasons as in the plains of India \ the sum-
mer solstice being every year marked by the same prevalence of rain,
which continues to fall without intermission until the autumnal equi-
nox. 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

INTRODUCTION. 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 mount-
ains of Cundinamarca, of Quito, and of Peru, furrowed by-
deep ravines, man is enabled to contemplate alike all the fam-
ilies 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 South-
em 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 dis-
play 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 decliv-
ities 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 gen-
eral results whose combination constitutes the physical deline-
ation oftJie torrid zone. That which, m the vagueness of our

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 agita-
ted by storms, and in 34° 7' lat., snow is found, several feet in thick-
ness, from December to March.

* See, generally, my Essai sur la Giograph'te des Plantes, et le Tor-
hleau 'physique des Regions Equinoxiales, 1807, p. 80-88. On the diur-
nal and nocturnal variations of temperature, see Plate 9 of my Atlat
Giogr. et Phys. du Nouveau Continent ; and the Tables in my work,
entitled De distributione Geographica Plantarum, secundum casli iempe-
riem, et altitudinem Montium, 1817, p. 90-116 ; the meteorological por-
tion 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 la-
quelle on irouve, sous les Tropiques, la couche de Temperature Invaria-
ble. (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

B2

34 COSMOS.

impressions, loses all distinctness of form, like some distant
mountain shrouded from view by a vail of mist, is clearly re-
vealed by the light of mind, which, by its scrutiny into the
causes ol" phenomena, learns to resolve and analyze their dif-
ferent 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 strong-
ly to the imagination, derives its collective interest from the
vivid truthfulness with which the individual features are por-
trayed.

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 reveaUng to man, by the uniformity of the vari-
ations of the atmosphere and the development of vital forces,
and by the contrasts of climate and vegetation exhibited at
different elevations, the invariability of the laws that regulate
the course of the heavenly bodies, reflected, as it were, in ter-
restrial 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 propor-
tion 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 con-
fines 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,
hs'fe given place to monocotyledons, whose slender spikes con-
fV^^^I tJiQ sole CQvering of the soil, "^kis i^ the 2?Qn9 of the

INTRODUCTION 35

^ asses, one vast savannah extending over the immense mount-
ain plateaux, and reflecting a yellow, almost golden tinge, tc
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 or-
ganization, 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 sum-
mits of the Cordilleras ; and even where these subterranean
forces have opened a permanent communication with the at-
mosphere, 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 trop-
ics 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 man-
ner in which they arrange themselves in successive groups,
would have enabled man more readily to attain to a knowl-
edge 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 re-
searches have rendered it very doubtful whether the primitive
seat of Hindoo civilization — one of the most remarkable phases
m the progress of mankind — was actually within the tropics
Airyana Vaedjo, the ancient cradle of the Zend, was situateci
to the northwest of the upper Indus, and after the great re
ligious schism, that is to say, after the separation of the Ira
uians from the Brahminical institution, the language that ha< !
previously been common to them and to the Hindoos assumei 1
among the latter people (together with the literature, habitj^,
and condition of society) an individual form in the Magodha c-i
Madhya Desa,* a district that is bounded by the great chaiu

* See, oa the M;idhiade9a, properly so called, Lassen'a exceilei i
work, tuitilled Indische Alter thunukunde, bd. i., 8. 92. The Chinese

S6 COSMOS.

of Himalaya and the smaller range of the Vindhya. 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,*

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
that, in these climates, affect the movements of the atmosphere
and the distribution of organic forms, it is to the inhabitants
of a small section of the temperate zone that the rest of man-
kind 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 civiliza-
tion 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 PhoBnicians 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 en-
joyment 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 im-
mortal poet has said, in our own tongue — Amid ceaseless
change seeks the unchanging pole.f

In order to trace to its primitive source the enjoyment de-
rived from the exercise of thought, it is sufficient to cast a
jfapid glance on the earliest dawnings of the philosophy of na-
ture, pr of the ancient doctrine of the Cosmos. We find even

give the name qf Mo-kie-thi to the southern Bahar, situated to the
Bouth of the Ganges (seiC Foe-Koue-Ki, by Chy-Fa-Hian, 1836, p. 256).
Djambu-dwipa is the name given to the v^rhole of India; but the words
also indicate one of the four Buddhist continents.

* Ueber die Kawi Spracke auf der Insel Java, nebst einer Einleitvng
uber die Verschiedenheit des menschlichen Spray.hbaues und ihren Ein
fiuss auf die geistige Entwickelung de$ Menschengeschlechfs, von Wil
helm V. Humboldt, 1836, bd. i., s. S-SIQ.

t This verse occurs in a poem of ^chiller, entitled Ver Spaziergatg
which first appeared in 1795, in tl^ie Horpi.

INTRODUCTION. 37

among the most savage nations (as my own travels enable me
to attest) a certain vague, terror-stricken sense of the all-pow-
erful unity of natural forces, and of the existence of an invisi-
ble, 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 revela-
tion 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, de-
veloping in the mind of man, as a simple product of ideal con-
ception, and independently of the aid of observation, the first
germ of a Philosophy of Nature.

Among nations least advanced in civilization, the imagina-
tion revels in strange and fantastic creations, and, by its pre-
dilection for symbols, alike influences ideas and language. In-
stead 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 en-
dowed with superior intelligence, appears in other regions, and
among entire races of men, to be the result of mystic tenden-
cies 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 pre-
serving 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, endeav-
ors 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. Inaccu-
rate and imperfect observations have led, by false inductions,
to the great number of physical views that have been perpet-
uated as popular prejudices among all classes of society. Thua
by the side of a sohd and scientific knowledge of natural phe-
nomena there has been preserved a system of tiie pretended

38 COSMOS.

results of observation, which is so much the more difficult to
shake, as it denies the vahdity of the facts by which it may
be refuted. This empiricism, the melancholy heritage trans-
mitted to us from former times, invariably contends for the
truth of its axioms with the arrogance of a narrow-minded
Bpirit. Physical philosophy, on the other hand, when based
upon science, doubts because it seeks to investigate, distin-
guishes between that which is certain and that which is mere-
ly probable, and strives incessantly to perfect theory by ex-
tending 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 perpet-
aates 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 7nea?i 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,
fur 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 rec
ognize 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 cultiva-
tion has given rise, in all classes of society, to an increased de-
sire of embellishing life by augmenting the m.ass of ideas, and
by multiplying means for their generalization ; and this sen-
timent fully refutes the vague accusations advanced against
the age in which we live, showing that other interests, be-
sides the material wants of life, occupy the minds of men.

It is almost with reluctance that I am about to speak of a
Rentiment, which appeirs 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,

INTRODUCTION. 39

«8 we learn more and more how to unvail her secrets, com-
prehend the mechanism of the movements of the heavenlv
bodies, and estimate numerically the intensity of natural forces
It is true that, properly speaking, the forces of nature can only
3xercise a magical power over us as long as their action is
shrouded in mystery and darkness, and does not admit of be-
ing classed dinong the conditions with which experience has
made us acquainted. The effect of such a power is, there-
fore, 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 tel
escopic comet in a group of nebulae, does not feel his imagina-
tion more excited — and this is the very guarantee of the pre-
cision of his labors — than the botanist who counts the divi-
sions of the calyx, or the number of stamens in a flower, or ex-
amines the connected or the separate teeth of the peristoma
surrounding the capsule of a moss. Yet the multiplied an-
gular 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.

We must not confound the disposition of mind in the ob
server 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 spark-
ling 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
of organic forms. The vault of heaven, studded with nebu-

* Arago's ocular micrometer, a happy improvement upon Rochon's
prismatic or double-refraction micrometer. See M. Mathieu's note iB
Dfelambre's Histoire de V Astronomie au dix-huitieme Siecle, 1827.

40 COSMOf5

la3 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 M^orthy 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 ignorafiice of natural
things that causes all our admiration, and chiefly excites our
passions,"

While the illusion of the senses would make the stars sta
tionary in the vault of heaven. Astronomy, by her aspiring la-
bors, has assigned indefinite bounds to space ; and if she have
set limits to the great nebula to which our solar system be-
longs, it has only been to show us in those remote regions of
space, which appear to expand in proportion to the increase
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 ex-
tent, reflects itself in the feehng of the infinite, which belongs
to another sphere of ideas included in the domain of mind.
The solemn and imposing impressions excited by this senti-
ment 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 de-
tails, 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 feel-
ings, and diminish the nobler enjoyments attendant upon a
contemplation of nature. Those who still cherish such erro
neous views in the present age, and amid the progress of pub-
lic opinion, and the advancement of all branches of knowledge,
fail in duly appreciating the value of every enlargement of the
sph<*re of intellect, and the importance of the detail of isolated
facts in leading us on to general results. The fear of sacri-
ficing the free enjoyment of nature, under the influence of sci-
entific 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 un versal fluctuation of phenomena and vital

^ mTRODUCTrc N. , 41

forces — fli 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 presenti-
ment 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 knowl-
edge. 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."

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 dis-
appeared in the great revolutions of our planet ; and as micro-
scopes 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 pro-
ductions, we see incessantly revealed the primordial mystery
of all organic development, that same great problem of Tneta-
morpJwsis which Gothe has treated with more than common
sagacity, and to the solution of which man is urged by his
desire of reducing vital form& to the smallest number of fun-
damental types. As men contemplate the riches of nature,
and see the mass of observations incessantly increasing be-
fore them, they become impressed with the intimate convic-
tion 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 scien-
tific observer untrodden paths of discovery. The regret of
Alexander can not be applied to the progress of observation
and intelligence.! General considerations, whether they treat
of the agglomeration of matter in the heavenly bodies, or of
the geographical distribution of terrestrial organisms, are not
onlyin 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 dif-
ferent branches of the study of natural history are only accessi-
ble in certain positions of social life, and do not, at every sea-

* Cams, Von den Urtheilen des Knochen und Sckalen Geruates, 18-281
$ 6 t Plut,, in Vita Alex. Magni, cap. 7

43 COSMOS.

Bon and in every cLmate, 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 w^ill 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 pro-
gressive 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 giv-
en period, succeed in dispelling a portion of the contradictions
which, at first sight, appear to arise from the complication oi
phenomena and the multitude of the perturbations simultane-
ously 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 mul-
tiple 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 habitu-
ally 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 compre-
hending the relations that exist between the most recent dis
coveries 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 diflferent 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 anta.rctic pole, whose fires
may be seen from afar, even at mid-day. It is by an ac-
quaintance with the results of distant voyages that we may
learn to comprehend some of the marvels of terrestrial mag-
netism, and be thus led to appreciate the importance of the
estal lishments of the numerous observatories which in the
present day cover both hemispheres, and are designed tc note

INTRODUCTION. 4J|

the simultaneous occurrence of perturbations, and the frequen-
cy and duration of magnetic storms.

Let me be permitted here to touch upon a few points con-
nected with discoveries, whose importance can only be esti-
mated 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 prehminary knowledge
of the orbits of comets, we should be unable duly to appre-
ciate the importance attached to the discovery of one of these
bodies, whose eUiptical 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 com-
prehended 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 chmatic 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 suffi-
cient guarantee against the exaggerated apprehension of a
general and progressive deterioration of the climates of Eu-
rope. Encke's comet, which is one of the three interior
comets, completes its course in 1200 days, biit 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 un-
equal 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 cential body.

44 COSMOS.

ITiere are variations, it is true, which, in obedience to the
laws of universal gravitation, affect the form of the earth's or-
bit and the inchnation of the ecHptic, 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 with-
in such narrow limits, that their therinic 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 dis-
tant 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 shoot-
ing stars, which probably form part of a belt of asteroids, in-
tersecting the earth's orbit, and moving with planetary ve-
locity.

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 1 By means of this instrument we
are enabled to trace the striking analogy which exists be-
tween the formation of the granular rocks composing the
lava currents ejected from active volcanoes, and those endog-
enous masses of granite, porphyry, and serpentine, which, is-
suing from the interior of the earth, have broken, as erup-
tive rocks, through the secondary strata, and modified them
by contact, either in rendering them harder by the introduc-
tion 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

INTRODUCTtON. , 46

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 ChiU, in consequence of a great earthquake, fur-
nished 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 i\w fact that the internal heat of the earth in-
creases so rapidly with the increase of depth that granite is
m 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 com-
position observed in thermal springs during a long course of
years. 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 dura-
tion 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 in-

* 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^ F.

[Dr. Mantell states in The Wondcis of Geology, 1848, vol. i., p. 34,
that this increase of temperature amounts to I'-* of Fahrenheit for every
fifty-four feet of vertical depth ,'] — Tr.**

'46 COSMOS.

terior of the globe, at a period when the earth's crust Wf.^
still furrowed and rent, and only in a state of semi-solidilica-
tion ; and a primordial condition is thus revealed to us, in
which the temperature of the atmosphere, and climates gen-
erally, were owing rather to a liberation of caloric and of dif-
ferent gaseous emanations (that is to say, rather to the ener-
getic reaction of the interior on the exterior) than to the posi-
tion of the earth with respect to the central body, the sun.

The cold regions of the earth contain, deposited in sedi-
mentary strata, the products of tropical climates ; thus, in
the coal formations, we find the trunks of palms standing up-
right amid coniferse, 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 polythalamia 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;t and, lastly, in transported soils, and in certain
caves, the bones of elephants, hyenas, and lions. 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
leep reflection, and opening new sources of study.

The number and the variety of the objects I have alluded
t;o 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

* 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 PaljEOuiscus (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 representa-
tives are still found in two genera, the Bichir of the Nile and Senegal,
and the Lepidosieus of the Ohio.

t [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 sili-
ceous shells of Gaillonellce, 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 masa
of animal culites. See the interesting work of G. A, Mautell, On ik,e
Medals of Creation, vol. i., p. 223.]— Tr.

INTRODUCTION. 47

descriptive natural history, geology, or mathematical astron-
omy ? 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 ac-
quainted with the specialities of phenomena, that he may ar-
rive 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 prepar-
ing on the physical laws of the universe, the greater part of
the facts advanced can be made manifest without the neces-
sity 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 efTect until the scaffolding is removed,
that had of necessity been used during its erection. 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 clea,rly apprehended without any knowledge of the geo-
desical 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

* G6the, ill Die Aphorismen uber Naturwissen»chaft, bd. 1.. s, 155
{ Werke kleine Ausgabe, von 1833.")

48 00SM03.

the equatorial aids exceeds the polar axis of the globe, and
Bhows T/s the mean equality of the flattening of the two hemi-
spheres, 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 regu-
lar ellipsoid of revolution, and that this irregularity is reflect-
ed 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 Verhdltniss
zur Natur und zur Geschichte, in which Carl Ritter so ably
delineates the physiognomy of our globe, and shows the influ-
ence 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 Sys-
teme du Monde, in which the author has combined the results
of the highest astronomical and mathematical labors, and pre-
sented them to his readers free from all processes of demon-
stration. 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 sepa-
raition of the general from the special, are not only conducive
to the attainment of perspicuity in the composition of a phys-
i'.al 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 ena-
bled 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
t he close of the last century, in the condition of all the special
i-ciences, more particularly of geology, chemistry, and descrip-
'ive natural history. In proportion as laws admit of more
.general application, and as sciences mutually enrich each other,
ind by their extension become connected together in more nu-
merous and more intimate relations, the development of gen-
eral truths may be given with conciseness devoid of superfici-
ality. On being first examined, all phenomena appear to ba

INTRODUCTION. 49

fwv.^«ied, and it is only by the result of a multiplicity of obser-
vations, 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 connec-
tion 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 dis-
covery, 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 phydcal geography,
combined ivith 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 regis-
tered 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 essen-
tial variations of the actual, whether in the form and arrange-
ment of natural objects in the struggle of man against the
elements, or of nations against nations, d ) not admit of being

Vol. I— C

60 COSMOS.

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 ; hut 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
world, exercise their action under the control of primordial
necessity, and in accordance with movements occurring period-
ically 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, obe-
dient 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 descrip-
tion of the universe, and appertains to a range of higher spec-
ulative views.

Emanuel Kant, one of the few philosophers who have es-
caped the imputation of impiety, has defined with rare sagac-
ity 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 re-
sisted 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 endow-

rNTKDDUCTION. 51

isd 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 tlie oppo-
site hemisphere. These 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 de-
velopment of certain parts, in the mode of junction of distinct
organs, in the differences in the balance of forces, or in a re-
semblance to intermediate forms which are not permanent,
but merely characteristic of certain phases of normal devel-
opment. 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 EHe de Beaumont, how chains of mountains dividing
different climates and floras and different races of men, revea)
to us their relative age, both by the character of the sediment-
ary strata they have uplifted, and by the directions which
they follow over the long fissures with which the earth's crusi
is furrowed. Relations of superposition of trachyte and ol
syenitic porphyry, of diorite and of serpentine, which remaii?
doubtful when considered in the auriferous soil of Hungary
in the rich platinum districts of the Oural, and on the south-
western declivity of the Siberian Altai, 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 accu-
mulated by chance. It has at length been fully acknowledg-
ed, 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 condi-
tion of the science he would enlarge, and is guided by reason
in his researches.

It is by this tendency to generalization, which is only dan-
gerous in its abuse, that a great portion of the physical knowl-
edge already acquired may be made the common property of
all classes of society ; but, in order to render the instruction
imparted 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

iM COSMOS.

knowledge. 1 take pleasure in persuading myself that scien-
tific subjects may be treated of in language at once dignified,
grave, and animated, and that those who are restricted with-
in the circumscribed limits of ordinary life, and have long re-
mained 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 acquisi-
tion 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 intel-
lect, and perceive how a judicious application of mechanics,
chemistry, and other sciences may be made conducive to na-
tional 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 mat-
ter 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 the-
oretical/' 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 cotemporaries could never have anticipated that
the action of the voltaic pile would discover to us, in the al-
kalies, metals of a silvery luster, so light as to swim on wa-
ter, 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 Huygens first ob-
served, 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, ox

INTRODUCTION. 53

whether comets transmit light directly or merely by reflec-
tion.*

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 en-
lightened employment of the products and forces of nature.
The most superficial glance at the present condition of Europe
|hows that a diminution, or even a total annihilation of na-
tional prosperity, must be the award of those states who shrink
with slothful indifierence from the great struggle of rival na-
tions in the career of the industrial arts. It is with nations
as with nature, which, according to a happy expression of
Gothe,t " knows no pause in progress and development, and
attaches her curse on ,all inaction." 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 ac
quaintance 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 in-
destructible 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 ovei
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 di
minish in proportion as neighboring countries become strength-
ened 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 knowl-
edge of the laws and the principles of unity that pervade the
vital forces of the universe ; and it is by such a course that

* Arago's Discoveries in the year 1811. — Delambre's Histoire de
VA»t., p. 652. (Passage already quoted.)

t G6the, in Die Aphorismen uber Naturwissenschqft. — Werhe, bd. 1.,

8. 4

.54 COSMOS.

physical studies may be made subservient to the prognss of in-
dustry, which is a conquest of mind over matter. By a hap-
py connection of causes and effects, w^e often see the useful link-
ed to the beautiful and the exalted. The improvement of agri-
culture in the hands of freemen, and on properties of a mod-
erate 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
contact of nations with each other, are all brilliant results of
the intellectual progress of mankind, and of the amelioratioff
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 char-
acteristic of the present age, should necessarily have a tenden-
cy 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
.magination. Where all the germs of civilization are devel-
oped beneath the spgis of free institutions and wise legislation,
ihere is no cause for apprehending that any one branch of
icnowledge should be cultivated to the prejudice of others.
All afford the state precious fruits, whether they yield nourish-
ment 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 Spar-
tans, notwithstanding their Doric austerity, prayed the gods
to grant them " the beautiful with the good."*

I will no longer dwell upon the considerations of the influ-
ence 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 appHcations. Ac-
customed 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 mount-
ains : they praise the view even when great part of the dis-
tant plains lie hidden by clouds, knowing that this half trans-
parent vapory vail imparts to the scene a certain charm from

* Pseudo-Plato. — Alcib., xi., p. 184, ed. Steph. ; Plut., Instituta La-
conica, p. 'i^yi, ed. Hutten.

INTRODUCTION. bo

thus pojver exercised by the imagination over the domain of the
senses. In like manner, from the height occupied by the phys-
ical history of the world, all parts of the horizon will not ap-
pear 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 unskill-
fulness of the guide who has imprudently ventured to ascend
these lofty summits.

'The object of this introductory notice is not, however, solelj
to draw attention to the importance and greatness of the phys
ical history of the universe, for in the present day these are tor.
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. " Na-
ture," 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 Ibrce of the uni-
verse — before all time, eternal, ever active, she calls to life all
things, M'hether 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 con
vert 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 re-
garded as a mere encyclopedic aggregation of the most im-
portant and general results that have been collected together
from special branches of knowledge. These results are noth
ing more than the materials for a vast edifice, and their com-
bination 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
diflerent 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 aa
vague as their limits are ill defined. In the work before us,
partial facts will be considered only in relation to the who]«

66 COSMOS.

The higher the point of view, the greater is the necessity lo»
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 worldj 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 man-
ifested 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 advant-
ages he has enjoyed in being permitted to express his thoughts
in his native language ; and truly happy is he who, in at-
tempting 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 effu-
sions of creative fancy, has for centuries past exercised so pow-
erful an influence over the destinies of man.

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

I HAVE endeavored, in the preceding part of my work, to
explain and illustrate, by various examples, how the enjoy-
ments presented by the aspect of nature, varying as they do
in the sources from whence they flow, may be multiplied and
ennobled by an acquaintance with the connection of phenom-
ena 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 ac-
cordance 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 phenoia*

INTRODUCTION. 5?

eiia which are found to be distributed in various groups, 1 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 uni«
verse, 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 anima-
tion to the description of distant regions and to the delineation
of natural scenery, as I'ar as it is characterized by vegetable
physiognomy and by the cultivation of exotic plants, and theii
arrangement in well- contrasted groups.

4. The history of the contemplation of nature, or the pro-
gressive 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 phenome-
na 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 pre-
sents 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
fhysics, 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
w^e 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

C2

58 COSMOS.

of empirical knowledge by terms which admit either (i too
wide or too limited a definition of the ideas which they were
intended to convey, and arc, besides, objectionable from hav-
ing had a different signification in those classical languages of
antiquity from w^hich they 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,
l:o substitute new and more appropriate terms for these ancient
designations, which, notwithstanding their undoubted vague-
ness, are now generally understood. These changes have been
proposed, for the most part, by those who have occupied them-
selves with the general classification of the various branches
of knowledge, from the first appearance of the great encyclo-
pedia [Margarita Fhilosophica) 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. t

* The Margarita Philosophica of Gregory Reisch, prior of the Char-
treuse at Freiburg, first appeared under the following title: Epitome
omnis Philosopliice, 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 1.535. This work
exercised a great influence on the diffusion of mathematical and physic-
al sciences toward the beginning of the sixteenth century, and Ci»xslf>s,
the learned author of VApen^u Historique des MUhodes en GeomHrtc
(1837), has shown tlie great importance of Reisch's Encyclopedia in
the history of mathematics in the Middle Ages. I have had recoui-se
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
Waldseemiiller), 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 G6o-
graphie du Nouveau Continent, et des Progres de V Astronomic Nautique
aux 15e et 16e Siecles, t. iv., p. 99-125.

t Ampere, Essai snr la Phil, des Sciences, 1834, p. 25. Whewell,

INTRODUCTION. 59

The selection of an inappropriate Greek nomenclature has per-
haps 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 uni-
verse as an object of the external senses, does undoubtedly re-
quire the aid of general physics and of descriptive natural histo-
ry, but the contemplation of all created things, vt^hich are linked
together, and form one whole, animated by internal forces, gives
to the science w^e are considering a peculiar character. Phys-
ical 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 consid-
ered as depending upon the primitive and vital action of one
sole force, from which emanate all the movements of the uni-
verse. 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 re-
pulsion 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, hav-
ing been elevated at different epochs, constitute distinct sys-
tems, whether they run in parallel lines or intersect one an-
other ; 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 prox-
imity 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

Philosophy of the Inductive Sciences, vol. ii., p. 277. Park, Pantoloey
p. 87. ^

* All changes in the physical world may be reduced to motion.
Aristut., Phys. Ausc, iii., 1 and 4, p. 200, 201. Bekker, viii., 1, 8, and
9, p. 250, 2G2, 265. De Genere et Corr., ii., 10, p. 336. Pseudo-Arift-
tot., De Mnndo. i np. vi., p. 308. -

()0 COSMOS.

considers volcanoes either as isolated, or ranged in single or in
double series, and extending their sphere of action to various
distances, either hy raising long and narrow lines of rocks, or
hy means of circles of commotion, which expand or diminish
in diameter in the course of ages. This terrestrial portion ot
the science of the Cosmos describes the strife of the liquid ele-
ment 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 theij
basins are unclosed ; and shows us rivers breaking through
the highest mountain chains, or following for a long time ?
course parallel to them,- either at their base, or at a consider-
able distance, where the elevation of the strata of the mount-
ain 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 belono
to the science whose true limits I am desirous of determining
and not the special enumeration of the greatest elevations oi
our globe, of active volcanoes, of rivers, and the number oi
their tributaries, these details falling rather within the domair
of geography, properly so called. We would here only con
sider phenomena in their mutual connection, and in their re
lations to different zones of our planet, and to its physical con
stitution generally. The specialities both of inorganic and qv
ganized matter, classed according to analogy of form and com
position, undoubtedly constitute a most interesting branch of
study, but they appertain to a sphere of ideas having no affin-
ity 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 differeni
descriptions, ranged in series, would as little give us a tru«
image of the general conformation of the irregular surface of
our globe, as a succession of all the floras of different region?
would constitute that which I designate as a Geography of
Plants. It is by subjecting isolated observations to the proces,*
of thought, and by combining and comparing them, that w(»
are enabled to discover the relations existing in common be
tween the climatic distribution of beings and the indivifvualit\
of organic forms (in the morphology or descriptive natuj il his-
tory of plants and animals) ; and it is by induction t> at we
are led to comprehend numerical laws, the j<roportion of nat-
ural families to the whole number of species, and to designate
the l^Aitude or geographical position -sf the zones in whose

INTRODUCTION. 6l

plains each organic form attains the maximum of its develop-
ment. Considerations of this nature, by their tendency to
generaUzation, impress a nobler character on the physical de-
scription 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 for-
merly given the pompous title of Systems of Nature, present
us with an admirably connected arrangement by analogies o\'
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 articula-
tions. But these pretended systems of nature, however ingen'
ious their mode of classification may be, do not show us or-
ganic beings as they are distributed m 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 recognize unity in the vast diversity of
phenomena, and by the exercise of thought and the combina-
tion 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 neces-
sary to descend to very special facts ; but this will only be in
order to recall the connection existing between the actual dis-
tribution of organic beings over the globe, and the laws of the
ideal classification by natural families, analogy of internal or-
ganization, 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 phys
ical history of the globe, the innumerable multitude of organ-
ized bodies which embellish creation are considered rather ac-
cording to zones of habitation or stations, and to differently
inflected isotherTual bands, than with reference to the princi-
ples of gradation in the development of internal organism.
Notwithstanding this, botany and zoology, which constitute

6^ COSMOS.

the i«{>. w'\ .> . atural history of all organized beings, are tha
fruitful ssbUices whence we draw the materials necessary to
give a solid basis to tho study of the mutual relations and
connection of phenomena.

We will here subjoin oi.e 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 — Graminese and
Orchideae, Coniferse and oaks, in local approximation to one
another ; while natural families and genera, instead of being
(ocally associated, are dispersed as if by chance. This disper-
sion is, however, only apparent. The physical description of
the globe teaches us that vegetation every where presents nu-
merically constant relations in the development of its forms
land 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 substi-
tution, which seems to depend upon some inherent mysteries
of the organism, considered with reference to its origin, main-
tains 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
find a principle of unity and a primitive plan of distribution
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 or-
ganic vitality — on the solid and liquid surface of our planet.
It might be said, in accordance with a beautiful expression of
Lavoisier, that tho ancient marvel of the myth of Prometheus
was incessantly renewed before our eyes.

If we extend the course which we have proposed, folrowing
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, ac-
oorditig to ancient but unphilosophical forms of nomenclature,
we would distinguish hetv^een physics, that is to say, geneial
considerations on the essence of matter, and the forces by which
it is actuated, and chemistry, which treats of the nature of
Bubstances, their elementary composition, and those attrac-
tions that are not determined solely by the relations of mass,
we nmst admit that the description of the (earth comprises at

INTRODUCTION. 63

wice physical and chefnical actions. In addition to gravita-
tion, 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. 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 depend-
ing upon the quantitative relations of matter or the distribu-
tion of masses. The phenomena of the regions of space may
"consequently be considered as influenced by simple dynamica 1
laws — the laws of motion.

The effects that may arise from the specific difference and
the heterogeneous 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
luminous waves, and by the influence universally exercised by
the force of gravitation or the attraction of masses. The ex-
istence of a periodical action of the sun and moon on the va-
riations 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 al-
ready 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

* On the question already discussed by Newton, regarding the differ-
ence 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 Mecaniqne Cileste, p, 3, 4 ; Kant, Metaph. Asfangx.
grimde der Naturwisseiischaff, Sam. Werhe, 1839, bd. v., s. 309 (Meta.
physical Principles of the Natural Sciences) ; Pectet, Physique, 1838.
vol. i., p. 59-63

64 ccsMos.

they are small celestial bodies, which, hving attracted by our
planet, are made to deviate from their orig-inal 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 com-
posing 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 sphe-
roids, being integrant parts of the same system, and having
one common origin, may likewise be composed of substances
chemically identical. Again, experiments with the pendulum,
particularly those prosecuted with such rare precision by Bes-
sel, confirm the Newtonian axiom, that bodies the most hete-
rogeneous in their nature (as water, gold, quartz, granular
limestone, and different masses of aerolites) experience a per-
fectly 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 satel-
lites, on Encke's comet of short period, and on the small planeta
Vesta, Juno, Ceres, and Pallas, indicates with equal certain-
ty that within the limits of actual observation attraction is
determined solely by the quantity of matter.t

This absence of any perceptible difference in the nature of
matter, alike proved by direct observation and theoretical de-
ductions, 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 Cosmo? is based on the pure and
abundant source of mathematical astronomy, as is the terres-
trial portion on physics, chemistry, and organic morphology ;
but the domain of these three last-named sciences embraoes

* [The analysis of an aSrolite which fell a few years since in Mary
land, United States, and was examined by Professor Silliman, of New
Haven, Connecticut, gave the following results : Oxyd of iron, 24 ; ox-
yd 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.

t Poisson, Connaissances des Temps pour r Annie 1836, p. 64-66.
Bessel, Poggendorf 's Annalen, bd. xxv., s. 417. Encke, Abkandlungen
der Berliner Academie (Trans, of the Berlin Academy), 1826, s. 2.^7.
Mitscherlich, Lehrbuch der Chemie (Manual of Chemistry), 1837 bd L
8. 352.

INTJRODUCTIOW. 65

the consideration of phenomena which are so complicated,
and have, up to the present time, been found so httle suscep-
tible 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 connec-
tion 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 Philolaiis, and subse-
quently through the analogous views of Aristarehus 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 meas-
ure, to the form of bodies, and to the number and distances of
the planets,^* while the Ionian physicists directed their atten
tion to the qualities of matter, its true or supposed metamor
phoses, and to relations of origin. 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 iae
material world.

Several highly distinguished treatises on physical geogra^ihy
are prefaced by an introduction, whose purely astronomical
sections are directed to the consideration of the earth ici its
planetary dependence, and as constituting a part of that §freat
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 0/ the
Cosmos, it is requisite that the sidereal portion, termed by
Kant the natural history of the lieavens, should Jiot be made
subordinate to the terrestrial. In the science of the Cosmos,
according to the expression of Aristarehus of Samos, the pio-
neer r{ the Copernican system, the sun, with its satellites,
was nothing more than one of the innumerable stars by v/fach
space is occupied. The physical history of the world raust,
therefore, begin with the description of the heavenly bodiea,
* Compare Otfried MttUer's Dorien, bd. i., s. 365.

60 COSMOS.

and with a geographical sketch of the universe, or, I would
rather say, a true map of the ivorld, such as was traced by
the bold hand of the elder Heftchel. If, notwithstanding the
srnallness 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
ii\ the extent of our knowledge of that which is accessible and
of that which is closed to our observation. This subordina-
tion of the celestial to the terrestrial portion is met with in the
great work of Bernard Varenius,* which appeared in the mid-

* Geographia Generalis in qua affectiones generates telluris expli-
cantur. The oldest Elzevir edition bears date 1650, the second 1672,
and the third 1G81; these were published at Cambridge, under New-
ton's supervision. This excellent work by Varenius is, in the truo
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 rich-
er 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-informed travelers. Generalis sive Universalis Geo-
graphia dicitur qutz teUurem in geyiere considerat atq7ie affectiones eX'
plicat, non habita particularism regionum ratione. The general de-
Bcription of the earth by Varenius (Pars Absoluta, cap. i.-xxii.) maybe
considered as a treatise of comparative geography, if we adopt the term
used by the author himseM {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 con-
tinents (p. 66, 7Q, ed. Cantab., 1681); a list of extinct volcanoes, and
Buch 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 ine height of neighboring coasts (p. 103) ;
the uniformity of level observed in all open seas (p. 97) ; the depend-
ence 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 ditFerences of temperature, &c. 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 Flx)rida (p. 140). Nothing can be more accurate than his
description of the current which skirts the western coast of Africa, be.
tv\een Cape Verde and the island of Fernando Po in the Gulf of Guinea.
Varenius explains the formation of sporadic islands by supposing them
la be " the raised bottom of the sea:" magna spiritnum inclusorum vi,
< tieut aliquando monies e terra protusos esse quidam scribunt (p. 225).
The edition published by Newton in 1681 {auctior et emendatior) un-
fortunately contains no additions from this great authority; and there
IH not even ment-on made of the polar compression of the globe, al-

INTRODUCTION. 67

d\e of th3 seventeenth century. He was the first to distinguish
between general and special geography, the former of which
he subdivides into an absolute, or, properly speaking, terres-
trial part, and a relative or planetary portion, according tc
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. Ii redounds to the glory of Varenius that his work on
General and Comparative GeograpJiy should in so high a
degree have arrested the attention of Newton. The imper-
fect state of many of the auxiliary sciences from which this
writer was obliged to draw his materials prevented his work
from cnrrespondmg 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
sldllful hand of Carl Ritter.*

The enumeration of the most important results of the as-
tronomical 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 ad-
venturous than the title. The introduction of new terms, es-
pecially with reference to the general results of a science which

though the experiments on the pendulum by Richer had been made
nine years prior to the appearance of the Cambridge edition. Newton's
Principia Mathematica Philosophicn Naturalis were not communicated
in manuscript to the Royal Society until April, 1686. Much uncer-
tainty seems to prevail regarding the birth-place of Varenius. Jaicher
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 ol
that city (see his Oeographia Comparaliva), 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 Ger-
many, and to the devastations of the Thirty Years' War. In his dedica-
tion of another work, Descriptio regni JaponicB (Amst., 1649), to the
Senate of Hamburgh, Varenius says that he prosecuted his elementary
inatliematical studies in the gymnasium of that city. There is, there-
fore, 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).

* Carl Ritter's Erdkunde im VerJidltniss zur Natur und zur Oeschichte
des Menschen, oder allgemeine vergleichen.de Geographie (Geography in
relation to Nature and the History e^ Man, or general Comparative
Geography).

68 COSMOS.

ought to be accessible to all, has always been greatly in oppo-
sition 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 in-
troduction of hitherto unknown objects rendered new names
necessary. The denominations of physical descriptions of the
universe, or physical cosmography, which I use indiscrimin-
ately, have been modeled upon those o^ 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 him
self by special studies, including even that of human anatomy.
The uncommon, but definite expression of the science of the
Cos?nos 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 cover-
nig over the surface of our rocks.

The influence of narrow-minded views peculiar to the ear
lier ages of civilization led in all languages to a confusion of
ideas in the synonymic use of the words earth and tvo7'ld,
while the common expressions voyages round the world, map
of the ivorld, and neio world, afford further illustrations of the
same confusion. The more noble and precisely-defined ex-
pressions 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 tho
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 uni-
form and regular movements of the sun and planets. Thus
the word Cosmos, which primitively, in the Homeric ages, in-
dicated an idea of order and harmony, was subsequently adopt-
ed 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 Philolaiis, whose fragmentary works have been so ably com-
mented upon by Bockh, and conformably to the general testi*

INTRODUCTION. (>9

moiiy of antiquity, Pythagoras was the first who used the
word Cosmos to designate the order that reigns in the uni-
verse, or entire world.*

* Koa/xoc, in the most ancient, and at the same time most precise,
definition of the word, signified ornament (,as an adoi'nment for a man,
a woman, or a horse) ; taken figuratively for evra^La, it implied the or-
der 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 writ-
ings ; but ancient attestation to the truth of this assertion is to be found
in several passages of the fragmentary works of Philolatis (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 Timfeus of Locris, since hig
authenticity is doubtful. Plutarch {De plac. Phil., ii., 1) says, in the
most express manner, that Pythagoras gave the name of Cosmos to the
universe on account of thirvrder which reigned throughout it; so like-
wise does Galen {Hist. Phil., p. 429). This word, together with its
novel signification, passed from the schools of philosophy into the lan-
guage ot poets and prose writers. Plato designates the heavenly bod-
ies by the name of Uranos, but the order pervading the regions of space
he too terms the Cosmos, and in his Timceus (p. 30, b.) he says that the
world is an animal endowed with a soul {k6(J(iov t^C)ov kfi'^vxov). Com-
pare Anaxag. Claz., ed. Schaubach, p. Ill, and Plut. {De plac, Phil.,
ii., 3), on spirit apart from matter, as the ordaining power of nature.
In Aristotle {De Casio, 1, 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., 2, 1, and I., 3, 13, p. 339, a, and 340, b, Bekk.) The def-
inition of Cosmos, which I have already cited, is taken from Pseado-Ar
istoteles de Mundo, cap. ii. (p. 39 D; tte passage referred to is as fol-
lows: Koa^og karl avarrjiia ef ovpaVov Kai yfig koI tuv ev Tovroig irepte-
XOfievcju (j>v(jeo)V. Aeyerat de kol iirepug KoaXog rj tuv &?.uv tu^lq re Kai
dtaKoa/xriaLg, vko ■&eC)v te Kai Slo, ■&eiov <j)VAaTTO{xevij. Most of the pas-
sages occurring in Greek writers on the word Cosmos may be found
collected together in the controversy between Richard Beutley 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, iu^Niike's excellent work, Sched.
Crit., 1812, p. b, 15; and, finally, in Thcophilus Schmidt, ad Cleom.
Cycl. Thcor., 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, Oesch. der Oriechisch-Romischen Philosophie, b. i., s. 252 (His-
tory of the Greco-Roman Philosophy). Each of these groups forming
thus a Cosmos, the universe, to ttuv, 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. BScfch has made
known inscriptions in praise of Trajan and Adrian ( Corpus Inscr. Greec,
1, n. 334 and 1036), in which Koaiiog occurs for oLKOviievrj, 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 spi,ce

70 COSMOS

From the Italian school of philosophy, the expression pas/J-
ed, in this signification, into the language of those early poeta

into three parts, the Olympus, Cosmos, and Ouranos (Stob., i., p. 488 ;
Philolatis, p. 94, 202) ; this division apphes to the different regions sur
rounding that mysterious focus of the universe, the 'Earia rod Txavrot,
of the Pythagoreans. In the fragmentary passage in w^hich this divi-
sion is found, the term Ouranos designates the innermost region, situ-
ated between the moon and earth ; this is the domain of changing
things. The middle region, where the planets circulate in an invaria-
ble and harmonious order, is, in accordance with the special concep-
tions entertained of the universe, exclusively termed Cosmos, while the
word Olympxis is used to express the exterior or igneous region. Bopp,
the profouud philologist, has remarked, that we may deduce, as Pott
has done, Etymol. Forschungen, th. i., s. 39 and 252 {Elymol. Research'
es), the word Kogijlo^ from the Sanscrit root ^sud\ jmrificari, by assum-
ing two conditions; first, that the Greek k in Kocfxog comes from the
palatial f , which Bopp represents by 's and PoTt by g (in the same man-
ner as deKa, decern, taihun in Gothic, comes from the Indian word dd-
san), and, next, that the Indian d' corresponds, as a general rule, with
the Greek d ( Vergleichende Grammatik, ^ 99 — Comparative Grammar),
which shows the relation of Koafioc (for Kbdjxoq) with the Sanscrit root
^sud\ whence is also derived Kadafioc. Another Indian term for the
world is gagai (pronounced dschagat), which is, properly speaking, the
present participle of the verb gagdmi (I go), the root of which is gd.
In restricting ourselves to the circle of Hellenic etymologies, we find
{Etymol. M., p. 532, 12) that Kooiioq is intimately associated with /ca^o,
or rather with KaLvv/2ai, whence we have KeKaafj-evoc or KEKadfiivo^.
Welcker {Eine Kretische Col. in Theben, s. 23 — A Cretan Colony m
Thebes) combines with this the name Kdd/zof, as in Hesychius Kudfio^
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 o{ KOCfioq (female ornament), was applied to
designate the entire universe. Ennius seems to have been the fii-st
who ventured upon this innovation. In one of the fragments of this
poet, preserved by Macrobius, on the occasion of his quarrel with Vir-
gil, we find the word used in its novel mode of acceptation : ^^ Mundus
caeli vastus constitit sileniip" (Sat., vi., 2). Cicero also says, '^ Quern nos
lucentem imindum vocamns'^ (Timx-us, S. dc 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, accord-
ing to Bopp, from Idk (to see and shine); it is the same with the Sola
vonic 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 veruld in Ang.b-Saxon, was, ac-
cording to James Grimm's interpretation, a period of time, an age (««-
culum), rather than a term used for the world in space. The Etruscans
figured to themselves mundu$ as an inverted dome, symmetrically op-
posed to the celestial vault (Otfried MUller's Etrusken, th. ii., s. 96,
&c.). Taken in a still more limited sense, the word appears to hava
signified among the Goths the terrestrial surface girded by seas (marei,
meri), the merigard, literally, garden of seas.

INTRODUCTION. 71

of nature, Parmenides and Empedocles, and from thence inta
the woiks of prose writers. We will not here enter into a
discussion of the manner in which, according to the Pythago
rean views, Philolaiis 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 Pythagoras, and in accordance with the precise
definition given of it in the treatise entitled De MuTzdo, which
was long erroneously attributed to Aristotle. It is the assem-
blage 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 sig-
nification, the present work ought rather to have borne the
title of Cosmography, divided into Uranogrdphy and Geog-
raphy. 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 regu-
larity in the disposition of parts. It is probable that the in-
troduction 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 pu
pils on the Pythagorean philosophy.

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 Ibi
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 nebula) 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 pic-
ture of all that exists in space — of the simultaneous action of

* See, on Ennius, the ingenious researches of Leopold Krahner, in
his Qrundlinien zur Geschickte des Verfalls der Romischen Staats-Reii

frion, 1837, s. 41-45 (Outlines of the History of the Decay of the Estab
ished Religion among the Romans). In all probability, Ennius did no'
quote from writings of Epicharmus himself, but from poems compose
in the name of that philosopher, and in accordance with his views

7^ COSMOS.

natural forces, together with the phena meaa which they pro-
duce.

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 for-
mation. It is not organic matter alone that is continually un-
dergoing change, and being dissolved to form new combina-
tions. The globe itself reveals at every phase of its existence
the mystery of its former conditions.

We can not survey the crust o£ our planet without recog-
nizing 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 successive-
ly displaced and succeeded each other. The different super
imposed strata thus display to us the faunas and floras of dif-
ferent epochs. In this sense the description of nature is inti
mately 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 C/ondition of an idiom reflected ni
the fornflS of speech in use at the present day. The study of
the material world renders this reflection of the past peculiar-
ly 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 (coulees) of amygdaloid with
elongated and parallel pores, and white deposits of pumice,
intei-mixed with black scoriae, animate the scenery by the as-
sociations 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 em-
ployed 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 1o consider it in its successive

INTRODUCTION. 73

phases. It is not, however, in the definition given by Vale-
rius Flaccus,*' but in the zoological writings of Aristotle, that
the word history presents itself as an exposition of the results
of experience and observation. The physical description of
the word by Pliny the elder bears the title of Natural His-
tory, while in the letters of his nephew it is designated by the
nobler term of History of Nature. The earher Greek his-
torians did not separate the descriptions of countries from the
narrative of events of which they had been the theater. With
these writers, physical geography and history were long inti-
mately 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 princi-
ple, 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 gen-
eration of men will ever have cause to boast of having com-
prehended 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,
^rand 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 advance-
ment have been made manifest in our own day, in the phe-
nomena 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 reason-

* Aui. Gell., Noct. Ati., v., 18.

Vol. I— D

74 COSMOS

ing is applied strictly to analogous phenomena ; but as soon
as dynamical views prove insufficient where the specific prop-
erties 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 impassable 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 composi-
tion, so happily recognized by modern chemists, and proclaimed
under the ancient form of atomic symbols, still remains isola-
ted and independent of mathematical laws of motion and grav-
itation.

Those productions of nature w^ich are objects of direct ob-
servation may be logically distributed in passes, 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 distri-
bution of groups, can not rise to the height of a classification
based on one sole principle of composition and internal organ-
ization. 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 dif-
ferently graduated phases in the investigation of the external
world. Empiricism originates in isolated views, which are
subsequently grouped according to their analogy or dissimilar-
ity. To direct observation succeeds, although long afterward,
the wish to prosecute experiments ; that is to say, to evoke
phenomena under different determined conditions. The ra-
tional 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 knowl-
edge, namely, relations of quantity, comprising ideas of num-
ber and size, and relations of quality, embracing the consider-
ation of the specific properties and the heterogeneous nature

INTRODUCTION. 76

of matter. The former, as being more accessible to the exer
cise of thought, appertains to mathematics ; the latter, from
Its apparent mysteries and greater difficulties, falls under the
domain of the chemical sciences. In order to submit phe-
nomena to calculation, recourse is had to a hypothetical con-
struction 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 organiza-
tion, have complicated our views generally, and shed an un-
certain light on the path we ought to pursue.

The most various forms of intuition have thus, age aftei
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 possi-
ble 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 complica-
tion of phenomena, and 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 eter-
nal 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 exclud€>
the classification of phenomena according to their rational con-
nection, the generahzation of many specialities in the great
mass of observations, or the attempt to discover laws. Con-
ceptions 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 fai
from blaming the efix)rts of others solely because their success
has hitherto remained very doubtful. Contrary to the wishes
and counsels of those profound and powerful thinkers who

76 COSMOS.

have given n^w life to speculations which were already fa-
miliar 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 ahuse of better powers, which has led many
of our noble but ill-judging youth into the saturnalia of a pure
ly ideal science of nature, has been signalized by the intoxica-
tion of pretended conquests, by a novel and fantastically sym-
bolical 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 phil-
osophical pursuits and experimental sciences have remained
strangers to these saturnalia. The results yielded by an earn-
est investigation in the path of experiment can not be at va-
riance 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 act-
ually 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 cul-
tivated languages, must not lead us to separate the sphere of
nature from that of mind, since such a separation would re-
duce 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 ex-
ternal 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 fur-
nished to it by the perceptions of the senses. Thus, in the

INTRODUCTION. 77

early ages of mankind, there manifests itself in the simple in'
tuition of natural facts, and in the efforts made to compre-
hend them, the germ of the philosophy of nature. These
ideal tendencies vary, and are more or less powerful, accord-
ing 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 imag
ination.

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 pene-
trated, 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 ob-
servation, 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 per-
fected. That which has been acquired by means so difierent
— 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 prop-
erty of mankind, and should not, 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 disad-
vantages ; we must not, therefore, be surprised if, in the per-
petual vicissitude of theoretical views, as is ingeniously ex-
pressed 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 her-
self share the fate of comets, bodies that do not rank in pop-
ular opinion among the eternal and permanent works of na-

* ScheUing's Bruno, TJeber das Gottliche und Naturaliche Princip.
ier Dinge, $ 181 (Bruno, on the Divine and Natural Principle o/
Things)

78 ' COSMOS.

ture, but are regarded as mere fugitive apparitions of igncoWl
vapor." 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 intellect, M^hich would imply that
the domain of mind is essentially a world of vague fantastic
illusions, and that the treasures accumulated by laborious ob-
servations in philosophy are powers hostile to its own empire,
[t 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 mutual connections, and at another that exercise of
the imagination which prompts and excites discoveries by its
creative powers.

COSMOS.

DELINEATION OF NATURE. GENERAL REVIEW OF
NATURAL PHENOMENA.

When the human mind first attempts to subject to its con-
trol the world of physical phenomena, and strives by medita-
tive 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 insen-
sible 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 our-
selves to be overpowered by a sense of the stupendous rich-
ness 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 in-
sight into the play of obscure forces, and b^"^ animated expres-
sions, in which the perceptible spectacle is rt fleeted with vivid
trulhfuhiess, that we may hope to comprehend and describe
the U7iiversal all {to -ndv) 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 im-
pression 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 re-
motest nebulas, we will gradually descend through the starry
zone to which our solar system belongs, to our own terrestrial
spheroid, circl ^.d by air and ocean, there to direct our atten-

80 C0SM03

taon to its form, temperature, and magnetic tension, ani to
consi'ier the fullness of organic life unfolding itself upon its
Mirface beneath the vivifying influence of light. In this man-
{^er a picture of the world may, with a few strokes, be made
I r include the realms of infinity no less than the minute mi«
ci -^scopic animal and vegetable organisms which exist in stand-
ing* 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 vari-
ously 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 pic-
ture 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 complete-
ness of th^ undertaking. The delineator of nature must re-''
sisif; 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 proper-
ties of matter — or, to speak more in accordance with the lan-
guage 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 tlierefore neces-
sarily prove unsuccessful. Thus, besides the pleasure derived
from acquired knowledge, there lurks in the mind of man,
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 receive^ from without, and that which it reflects
from its own dej' ths 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 it-
self to the haman 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 acknowledgment is due where the actual state and pro-
spective 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 ef-
fort to embrace nature in its universality may remain unsatis-
fied, the history of the contemplation of the universe (which

h

DELINEATION OF NATURE. . 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 msight 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 ex-
pression 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 at-
tainment and the rectification of the mean values of certain
quantities by means of the processes of weighing and meas-
uring ; and it may be said, that the only remaining and wide-
ly-diffused hieroglyphic characters still in our writing — num-
bers— 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 nu-
merical 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 long-
ing 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

D2

82 COSMOS.

to distant regions. The belief in the uncommon and the won-
derful lends a definite outline to every manifestation of ideal
creation ; and the realm of fancy — a fairy-land of cosmolog
leal, geognostical, and magnetic visions — becomes thus invol-
untarily blended with the domain of reality.

Nature, in the manifold signification of the vi^ord — whether
considered as the universality of all that is and ever will be-
as the inner moving force of all phenomena, or as their mys-
terious prototype — reveals itself to the simple mind and feel-
ings of man as something earthly, and closely allied to him-
self. It is only within the animated circles of organic struc-
ture 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 uni-
verse, in which the magnitude of masses, the number of con-
gregated 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
lo-yver portion of space. If, then, a picture of nature were to
correspond to the requirem^ents of contemplation by the senses,
it ought to begin with a deUneation 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 strata ; 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," sup-
porting the vault of heaven. It begins to exercise its action

CELESTIAL PHENOMENA. 83

nt the spot where it originated, and passes from the consider-
ation 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 admirahle in a mathe-
matical 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, there-
fore, we do not proceed from the subjective point of view of
human interests. The terrestrial must be treated only as a
part, subject to the whole. The view of nature ought to be
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
terrestrial, but with that which fills the regions of space. But
as the sphere of contemplation contracts in dimension our per-
ception of the richness of individual parts, the fullness of phys-
ical phenomena, and of the heterogeneous properties of mat-
ter becomes enlarged. From the regions in which we rec-
ognize only the dominion of the laws of attraction, we de-
scend to our own planet, and to the intricate play of terrestrial
forces. The method here described for the delineation of na-
ture is opposed to that which must be pursued in establish-
ing conclusive results. The on? 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 me-
dium 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 in 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 dens-
ity and size, or scattered through space in the form of self-
luminous vapor. If we consider first the cosmical vapor dis
persed in definite nebulous spots, its state of aggregation will

84 COSMOS

appear constantly to vary, sometimes appearing separated into
round or elliptical disks, single or in pairs, occasionally con-
nected by a thread of light ; whiles 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, inclosing a dark interior. It is conjectured
that these bodies are undergoing variously developed formative
processes, as the cosmical vapor becomes condensed in con-
formity with the laws of attraction, either round one or more
of the nuclei. Between two and three thousand of such un-
resolvable 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 sec
the same kind of tree in all the various stages of its growth,
and are thus enabled to form an idea of progressive, vital de-
velopment, so do we also, in the great garden of the universe,
recognize 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 conject-
ure 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
whiish tvill be, even though the latter be nothing more than
a new condition of a known material existence ; for ef actual
creation, of origin, the beginning of existence from non-exist-
ence, we have no experience, and can therefore form no con-
ception.

A comparison of the various causes influencing the develop-
ment manifested by the greater or less degree of condensation
in the interior of nebulae, no less tharl a successive course of
direct observations, have led to the belief that changes of form
have been recognized first in Andromeda, next in the constel-
lation 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.

CELESTIAL PHENOMENA. 85

Nebulous stars must not be confounded either with irregu-
larly-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 cir-
cular or slightly oval disks manifest in all their parts a per-
fectly uniform degree of faint light. Nebulous stars are not
merely accidental bodies projected upr i a nebulous ground,
but are a part of the nebulous matter constituting one mass
with the body which it surrounds. The not unfrequently con-
siderable magnitude of their apparent diameter, and the re-
mote distance from which they are revealed to us, show that
both the planetary nebula? 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 differ-
ence between the central body and the surrounding nebulous
covering can no longer be detected by our telescopic instru-
ments.

The magnificent zones of the southern heavens, between
50° and 80°, are especially rich in nebulous stars, and in com-
pressed unresolvable nebulae. The larger of the two Magel-
lanic 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

* 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 explain
ed in Arago's Analyse des Travaux de Sir William Herschel (Annuaire
du Bureau des Long., 1842, p. 410-412, and 441).

t 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 diflferent magnitudes and degrees of con
densation. This is interspersed with nebulous spots, not resolvable
into stars, but which are probably star dust, appearing only as a general
radia^nce upon the telescopic field of a twenty -feet reflector, and form-
ing a luminous ground on which other objects of striking and inde-
scribable form are scattered. In no other portion of the heavens are
so many nebulous and ste.lar masses thronged together in an equally
small space. Nubecula minor is much less beautiful, has more unre-
solvable nebulous light, while the stellar masses are fewer and fainter
in intensity. — (From a letter of Sir John Herschel, Feldhuysen, Cap6
of Good Hope, 13th June, 1836.)

86 COSMOS.

not resolvable which, producing a general brightness in the
field of view, 1< rm, as it were, the back-ground of the picture."
The appearance of these clouds, of the brightly-beaming con-
Btellation Argo, of the Milky Way between Scorpio, the Cen-
taur, 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 con-
stantly 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 observa-
tions indio-ate the existence and the general distribution of an
apparently non-luminous, infinitely-divided matter, which pos-
sesses a force of resistance, and manifests its presence in Encke's,
and perhaps also in Biela's comet, by diminishing their eccen-
tricity and shortening their period of revolution. Of this im-
peding, 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 mat-
ter of the immeasurable regions of space {ovpavov x^pTog)*
— whether, scattered without definite form and limits, it ex-
ists as a cosmical ether, or is condensed into nebulous spots,
and becomes comprised among the solid agglomerated bodies
of the universe — ^we approach a class of phenomena exclusive-
ly designated by the term of stars, or as the sidereal world.

* I should have made use, in the place of garden of the universe, of
the beautiful expression ;t;6/9rof ovpavov, borrowed by Hesychius from
an unknown poet, if ;t;6prof had not rather signified in general an in-
closed space. The connection with the German garten and the En-
glish garden, gards in Gothic (derived, according to Jacob Grimm, from
gairdan, to gird), is, however, evident, as is likewise the affinity with
the Sclavonic grad, gorod, and as Pott remarks, in his Etymol. Forschun-
gen, th. i., s. 144 (Etymol. Researches), with the Latin chors, whence
we have the Spanish carte, the French cour, and the English word court,
together with the Ossetic khart. To these may be further added the
Scandinavian gard,^ gdrd, a place inclosed, as a court, or a country
seat, and the Persian gerd, gird, a district, a circle, a princely country
Beat, a castle or city, as we find the term applied to the names of places
in Firdusi's Schahnameh, as SiyawaTcschgird, Darabgird, &c.

* / This word is written gaard in the Danish.l — TV.

CELESTIAL PHENOMENA. 87

Here, too, we find difierences existing in the solidity or density
of the spheroid ally agglomerated matter. Our own solar sys-
tem 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 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 probahly 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 ar-
rangement 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 inves-
tigation 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 ele-
gant inscription on his monument at Upton, broke through the
inclosures of heaven (coslorum pei'rupit claustra), and, like
another Columbus, penetrated into an unknown ocean, from
which he beheld coasts and groups of islands, whose true po-
sition 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 numeric-
al frequency on telescopic fields of equal magnitude, have led
to the assumption of unequal distances and distribution in space
in the strata w^hich they compose. Such assumptions, in as
far as they may lead us to draw the limits of the individual
portions of ihe universe, can not offer the same degree of math-
ematical certainty as that which may be attained in all that

88 COSMOS,

relates to our solar system, whether we consider the rotation
of double stg.rs with unequal velocity round one common cen-
ter 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 i-- the obscurity of antiquity, the other in that of inac-
cessible 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 imagme mat-
ter to be distributed in groups, either as unresolvable nebulas
of different ages, condensed around one or more nuclei, or as
already agglomerated into clusters of stars, or isolated sphe-
roidal bodies. The cluster of stars, to which our cosmical isl-
and 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 de-
termined for the brightest star in the Centaur (0"*9128), that
fight 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 prox-
imity), that a period of nine years and a quarter is required
for the transmission of light irom this star to our planet. Our
starry stratum is a disk of inconsiderable thickness, divided a

* 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"-0640. For 61 Cygni, see Bessel, in Schumacher's Jahi--
buch, 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 difi'erent magnitudes, how those of the third mag
uitude 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 Astronomies Copernicance, 1618, t. i., lib. 1, p. 34-39: ^' Sol
hie 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
VICE lactecB, tunc hcec via lactea apparebit circulus parvus, vel ellipsis par-
va, tola declinans ad latus alterum; eritque simul uno intuitu conspicuf.,
quce nunc nan potest nisi dimidia conspici quovis momento. Itaque Jix
arum sphcera non tantum orbe stellarum, sed etiam ci^culo lactis Vfrnut
not deorsum est terminataJ'''

SIDEREAL SYSTEMS. 89

third of its .ength 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 stra-
tum 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 iiTthe same man-
ner 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 lummous vapor, and are perspec-
tively grouped, encircling, as in a zone, the visible vault of
heaven. This narrow and branched girdle, studded with ra-
diant light, and here and there interrupted by dark spots, de-
viates only by a few degrees from forming a perfect large cir-
cle 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 tele-
scopic vision as a ring, and at a still greater distance as a re-
solvable 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 stara
(double stars or suns), these bodies are not subject, with re-
spect to relative motion and illumination, to the same planet-
ary 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 sys-

90 COSMOS.

tein the center of gravity is often comprised within the innei
most 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 multi-
ple cluster of stars, the analogy thus suggested must be limit-
ed to the universality of the laws of attraction in different sys-
tems, 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
resj)ect to the different classes of individually agglomerated
matter, and the relative size, conformation, density, and dis-
tance 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 satel-

* [Since the publication of Baron Humboldt's work in 1845, several
other planets have been discovered, making the number of those be-
longing 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 dis-
covered 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 de-
terminations 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 2\ years). The planet Neptune, which, after having
been predicted by seveml astronomers, was actually observed on tho
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 scieuce^
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 succeed-
ed tho 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 " »

PLANETARY SYSTEMS. 91

iites 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. We may, with no inconsiderable degree of proba-
bility, include within the domain of our Sun, in the immedi-
ate sphere of its central force, a rotating ring of vaporous mat-
ter, lying probably betM'een the orbits of Venus and Mars, but
certainly beyond that of the Earth,^ which appears to us' in

formal incompatibility between the observed motions of Uranus and
the hypothesis that he was acted on only by the Sun and known plan-
ets, according to the law of universal gravitation." Pursuing this idea,
Leverrier arrived at the conclusion that the disturbing cause must be a
vlanet, and, finally, after an amount of labor that seems perfectly over-
whelming, he, on the 31st of August, 1846, laid before the Frepch In-
stitute a paper, in whicri he indicated the exact spot in the heavens
where this new planetaiy body would be iound, 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^^ 47'; mass, ^aVo^h; heliocentric long., Jan. 1st,
1847, 326° 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 expect-
ed the new planet would appear, this being one of a series of maps
made for the Academy of Berlin, of the small stars along the entire zo-
diac. By means of this valuable assistance. Dr. Galle, of the Berlin
Observatory, was led, on the 25th of September, 1846, by the discov-
ery 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 futuro 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, ^jVo*!^* i^
only about -_^^^th 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 ac-
curate observations have been made regarding its system of satellites.
Bee Trans. Astron. Soc./dnd The Planit Neptune, 1848, by J. P. Nichoil. ]
— Tr.

• " If there shoild be molecules in the zones ditfused by the atmoa

92 COSMOS

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 starti
When we consider the complication of variously-formed bodies
which revolve round the Sun in orbits of such dissimilar ec-
centricity— although we may not be disposed, with the im-
mortal author of the Mecanique Celeste, to regard the larger
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, re-
volve with but slightly eccentric orbits round the Sun), con-
stitutes but a small portion of the whole system with respect
to individual numbers, if not to mass.

It has been proposed to consider the telescopic planets, Ves-
ta, Juno, Ceres, and Pallas, with their more closely intersect-
ing, 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 contrastst when ^compared with the exterior grouj),
comprising Jupiter, Saturn, and Uranus. The planets near-
est 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 satel-
lites may be ascribed to Uranus, have a quantitative prepon-
derance in the number of their attendant moons, which is as
seventeen to one.

phere 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 cir-
cling round that luminary, present all the appearances of zodiacal light,
without opposing any appreciable resistance to the different bodies com-
posing the planetary system, either owiug to their extreme rarity, or
to the similarity existing between their motion and that of the plnncfa
with which they come in contact." — Laplace, Expos, du Syst. du Mond^
(ed. 5), p. 415.

* Laplace, Exp. du Syst. du Wonde, p. 396, 414.

t Littrow, Astronomie, 1825, bd. xi., $ 107. Miidlcr Astron., 1841,
$ 212. Laplace, Exp. d* Syst. du Monde, p. 210.

PLANETARY SYSTEMS. 98

Su3h 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 revolv-
ing planets from the central body, and their absolute size,
density, period of rotation, eccentricity, and the inclination of
their orbits and the axes. We know as yet of no inherent ne-
cessity, no mechanical natural law, similar to the one which
teaches us that the squares of the periodic times are propor-
tional 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 vol
ume, immediately precede 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 aster-
oids, which scarcely admit of measurement, have an areal sur-
face not much more than half that of France, Madagascar, or
Borneo. However striking may be the extremely small dens-
ity of all the colossal planets, which are furthest removed from
the Sun, we are yet unable in this respect to recognize any
regular succession.* Uranus appears to be denser than Sat-
urn, even if we adopt the smaller mass, a-jo o 5» assumed by
Lament ; and, notwithstanding the inconsiderable difference
of density observed in the innermost planetary group,t we find
both Venus and Mars less dense than the Earth, which lies
between them. 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 el-

* See Kepler, on the increasing density and volume of the planets in
proportion with their increase of distance from the Sun, which is de-
scribed as the densest of all the heavenly bodies ; in the Epitome A*-
iron. Copern. in vii. libros digesia, 1618-1622, p. 420. Leibnitz also in-
clined to the opinions of Kepler and Otto von Guericke, that the plan-
ets 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 Schri/ien, herausg. von Guhrauer, th. i.,
§ 264.

t On the arrangement of masses, see Encke, in Schum., Astr. Nachr^
1843 Nr.488, $ 114.

114 COSMOS.

liptic orbits of Juno, Pallas, and Mercury have the greatest
degree of eccentricity, and Mars and Venus, which immedi-
ately follow each other, have the least. Mercury and VenuB
exhibit the same contrasts that may be observed in the four
smaller planets, or asteroids, whose paths are so closely inter-
woven.

The eccentricities of Juno and Pallas are very nearly iden-
tical, and are each 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 eccen-
tricity. 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 twen-
ty-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 ir-
regular 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 sec-
ond and fourth, have been recently observed with certainty,
that the axis of this, the outermost of all the planets, is scarce-
ly incUned as much as 11° toward the plane of its orbit, while
Saturn is placed between this planet, whose axis almost coin-
cides with the plane of its orbit, and J upiter, 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 ex-
istence, 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 de-
gress 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 un*

I

FliANETARV SYSTEMS. 9&

known conditions, although man considers as accidental what'
ever he is unable to explain in the planetary formation on pure-
ly 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 dens-
ity, 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 difference in 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 geog-
nostic relations of the elevations of continents ; but we are un-
able from 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 ex-
istence 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 at variance with the conception of a series,
owing to the necessity for a supposition in the case of the first
member.

The hitherto discovered principal planets that revolve round
our Sun are attended certainly by fourteen, and probably by
eighteen secondary planets (moons or satellites). The princi-
pal planets are, therefore, themselves the central bodies of sub'
ordinate systems. We seem to recognize in the fabric of the
universe the same process of arrangement so frequently ex-
hibited 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 extern-
al region of the planetary system, lying beyond the intersect-
ing orbits of the smaller planets or asteroids ; in the inner re-
gion none of the planets are attended by satellites, with the
exception of the Earth, whose moon is relatively of great mag-
nitude, since its diameter is equal to a fourth of that of the
Earth, while the diameter of the largest of all known second
ary planets — the sixth satellite of Saturn — is probably aboui
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 tne
largest number of satellites are most remote from the Surv

96 cosMjs.

Rnd are at the same time the largest, most compressed at the
poles, and the least dense. According to the most recent
measurements of Madler, Uranus has a greater planetary
compression than any other of the planets, viz., g-.^p-^d. 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 consider-
able than are usually observed to exist between the principal
planets and their attendant satellites, or between bodies of
difierent orders m the solar system. While the density of tho
Moon is five ninths less than that of the Earth, it would ap-
pear, 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 satelUtes 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 satel-
lites, approach the nearest to the third and brightest of Jupi-
ter'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 Ibrty-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 Lament at Munich. Determinations of the true di-
ameter of satellites, made by the measurement of the apparent
size of their small disks, are subjected to many optical diffi-
culties ; but numerical astronomy, whose task it is to prede-
termine by calculation the motions of the heavenly bodies as
they will appear when viewed from the Earth, is directed al-

* If, accoi'ding to Burckhardt's determination, the Moon's radius be
0.2725 and its volume ^^^-^th, its density will be 0*5596, or nearly five
ninths. Compare, also, Wilh. Beer und H. Madler, der Mond, $ 2,
10, and Madler, Ast., $ 157. The material contents of the Moon are,
according to Hansen, nearly ^^^th (and according to Madler ^^.^th)
that of the Earth, and its mass equal to 37 \s^ ^^^^ °^ *^^^ Earth. In
the largest of Jupiter's moons, the third, the relations of volume to the
central body are x^^oth, and of mass ^^i._^th. On the polar flattea-
uig of rjranus, see Schum., Astron. Nachr.^ 1844, No. 493.

I'LANETARY SYSTEMS. 97

most exclusively to motion and mass, and but little to volume.
The absolute distance of a satellite from its central body ia
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 dis-
tance between Uranus and its sixth satellite (if the latter real-
ly exist) amounts to as much as 1,360,000 miles. If we com-
pare, in each of these subordinate systems, the volume of the
main planet with the distance of the orbit of its most remote
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 satel-
lite 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 aijy 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 Madler
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 passectover 72,800
miles. If, instead of absolute distances, we take the semi-di-
ameters 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 Jupitel
from its center, while our moon is removed from us fully 60 ^d
3emi -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 anothei
and with reference to their attendant satellites. The twelve
moons of Saturn, Jupiter, and the Earth all move like the
primary planets from west to east, and in elliptic orbits, de*
V^oL. I — E

98 COSMOS.

viating but little from circles. It is only in the case of om
moon, and perhaps in that of the first and innermost of tha
satellites of Saturn (0-068), that we discover an eccentricity
greater than that of Jupiter ; according to the very exact ob-
f errations of Bessel, the eccentricity of the sixth of Saturn's
saiellites (0-029) exceeds that of the Earth. On the extremes!
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
have certainly been but imperfectly investigated) exhibit the
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 rmg, which may be regard-
ed as a fusion of agglomerated satellites) moving from west tc
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 plan-
etary atmospheric vapor, there must have existed singular
causes of retardation or impediment in the vaporous rings re-
volving round Uranus, by which, under 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 j)lanet, and therefore that they always present to
the latter the same side. Inequalities, occasioned by slight
variations in the revolution, give rise to fluctuations of from
6'^ to 8^, or to an apparent libration in longitude as well as
in latitude. Thus, in the case of our moon, Ave sometimes
observe more than the half of its surface, the CEistern and
northern edges being more visible at one time, and the west-
ern or southern at another. By means of this libration* we
are enabled to see the annular mountain Malapert (which oc-
casionally conceals the Moon's south pole), the arctic land-
scape round the crater of Gioja, and the 'arge gray plane near
Endymion, which exceeds in superficial extent the Mare Va-
porum. Three sevenths of the Moon's surface are entirely

* Beer and Madler, op. cit., § 185, s. 208, and $ 347, 9 SS'i; and it
'-heir Phys. Kenntniss der himml. Korper, s. 4 und 69, T&b, 1 (Physic
al History of the Heavenly Bodies).

COMETS. W

concealed from our observation, and must always remain so,
unless new and unexpected d;sturbing causes come into play.
These cosmical relations involuntarily remind us of nearly
similar conditions in the intellectual world, where, in the do-
main 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, ta
the human mind, appearing, from time to time, either glim-
mering in true or delusive light. We have hitherto consid-
ered 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 to-
gether by mutual attraction ^ it therefore now only remains
for us to speak of the unnumbered host of comets which con-
stitute a portion of the cosmical bodies revolving in independ-
ent orbits round the Sun. If we assume an equable distribu-
tion 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 esti-
mates on the rules of the calculus of probabilities, we shall
obtain as the result an amount of myriads perfectly astonish-
ing. 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 afibrd any
information regarding its apparent path, the copious literature
of the Chinese (who observed nature carefully, and recorded
Vith 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.*

* The first comets of whose orbits we have any knowledge, and
which were calculated from Chinese observations, are those of 240 (un-
der Gordian III.), 539 (under Justinian), 565, 568, 574, 837, 1337, and
1385. See .John Russeli Hind.in Schiim,, Astron. Nackr., 1843, No. 498.
While the comet of 837 (which, according to Du Scjour, continued dun

100 COSMOS.

Althougli comets have a smaller mass than any other cos-
mical bodies — being, according to our present knowledge, prob-
ably not equal to joVo'^h part of the Earth's mass — yet they
occupy the largest space, as their tails in several instances ex-
tend over many millions of miles. The cone of luminous va
por 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 rath
er to appertain to the individual than the class, that a de-
scription of one of these " wandering light-clouds," as they
were already called by Xenophanes and Theon of Alexandria,
cotemporaries 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 concentrated toward the middle. This is the most
simple type ; but it can not, however, be regarded as rudi-
mentary, since it might equally be the type of an older cos
mical 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 de
nominated 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,

iug 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 him
self 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°, 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 coo-
et, 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 Laugier, Comptes Rendus des Stances de VAcad., 1843, t. xvi.,
1006.

* 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 Feb-
ruary (according to the tistimony of J. G. Clarke, of Portland, state of

COMETS. 101

for instance, in the large comets of 1402, 1532, 1577, 1744,
and 1843. 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 splen-
did one of 1811, exhibited well-defined disks ;* the one at an
angle of 1", and the other at 0"*77, whence the true diame-
ters are assumed to be 536 and 428 miles. 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 con-
tinued visible for so long a period, the nucleus and its nebu-
lous 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, bright-
ly shining zones being in many cases separated by concentric
nebulous envelopes. The tails sometimes appear single, some-
times, 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^. The tails have been sometimes
straight, sometimes curved, either toward both sides, or to-
ward 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 ap-
peared 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 or less thick-
Maine), between 1 and 3 o'clock in the afternoon.* 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 nu-
cleus. {Amer. Journ. of Science, vol. xlv., No. 1, p. 229.)

* 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 En-
glish miles. For the magnitudes of the comets of 1798 and 1805, see
Arago, Annuaire, 1832, p. 203.

a [The translator was at New Bedford, Massachusetts, U. S., on the 28th Febru*
ry, 1843, and distinctly saw the comet, between 1 and 2 in the afternoon. The skj
at the time was intensely blue, and the sun shining with a dazzling brightness un.
Known in European climates.] — Tr

102 COSMOS.

ness, and, considered in this manner, they furnish a simple
explanation of many of the remarkable optical phenomena al-
ready 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°), but we also see the same
comets undergoing successive and rapidly-changing processes
of configuration. These variations of form have been most
iccurately 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 be-
ing bent backward, formed a part of the tail. The nucleus
of Halley's comet, with its emanations, presented the appear-
ance of a burning rocket, the end of which was turned side-
ways 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.*
The great Konigsberg astronomer concluded from many meas-
urements, 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 opin-
ion that they indicate a polar force, which turns one semi-di-
ameter of the comet toward the Sun, and strives to turn the
opposite side away from that luminary. The magnetic polar
ity 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 equi-
noxes," This is not the place to enter more fully upon the
grounds on which explanations of this subject have been bas-
ed ; but observations so remarkable,! and views of so exalted

* Arago, Des Changemenis physiques de la Comite 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. " Corn's radios so-
lis effugiunty — Seneca, Nat. Qucest., vii., 20.

t Bessel, in Schumacher, Astr. Nachr., 1836, No. 300-302, s. 188, 193;

COMETS. 105^

t character, regarding the most wonderful class of the cosmic-
al bodies belonging to our solar system, ought not to be en-
tirely passed over in this sketch of a general picture of nature.

Although, as a rule, the tails of comets increase in magni-
tude 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°. 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 occa-
sioned a double, unchecked, continuous emanation of nebulous
matter.*

Aristotle, in his Natural Philosophy, makes these emana-
tions 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, in-
candescent matter. The nebulous belt which separates the
different portions of the vault of heaven was therefore regard-
ed by the Stagirite as a large comet, the substance of which
was incessantly being renewed.!

197, 200, 202, und 230. Also in Schumacher, Jahrb., 1837, s. 149, 168.
William Herschel, in his observations on the beautiful comet of 1811,
beliesed that he had discovered evidences of the rotation of the nucleus
and tail {Phil. Trans, for 1812, Part i., p. 140). Dunlop, at Paramat-
ta, thought the same with reference to the third comet of 1825.

* Bessel, in Astr. Nachr., 1836, No. 302, s. 231. Schum., Jahrb., 1837,
e. 175. See, also, Lehmann, Ueber Cometenschxceife (On the Tails of
oomets), in Bode, Astron. Jahrb. fur 1826, s. 168.

t 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 vv^hole of the Middle Ages, it is very
(uucli to be regretted that he was so averse to those grander views of
the elder Pythagoreans, which inculcated ideas so nearly approxima-
ting 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, accord-
ing to which these cosmical bodies are supposed to be planets having
long periods of revolution. (Aristot., i,, 6, 2.) This Pythagorean doc-
trine, which, according to the testimony of ApoUonius 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. Qncest., vii., 17: " Cometea
pon est species falsa, sed proprium sidus sicut soils et luiicB : altiora mun-
di secat et tunc demum apparet quum in imum cursum sui venit ;" and
ligain (at vi'., 27), " Co metes aternos esse et sortis ejusdem, cujus ceetera

104 COSMOS.

The occultation of the fixed stars by the nucleus of a com
et, 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 occultation 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. 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 experi-
encing any deflection during its passage.! If such an absence
of refracting power must be ascribed to the nucleus of a com-
et, 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

(sidera), etiamsi faciem illis non hahent similem.'' Pliny (ii., 25) also re-
fers to Apollonius Myndius, when he says, "Sunt qui et hcec sidera per-
pettia esse credant stioque ambitu ire, sed non nisi relicta a sole cerni."

* Olbers, in Astr. Nachr., 1828, s. 157, 184. Arago, De la Constitu-
tion physique des C o metes ; Annuaire de 1832, p. 203,208. The an-
cients 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 bten seen through comets is that of Democritus
(Aristot., Meteor. y i., 6, 11), and the statement leads Aristotle to make
the not unimportant remark, that he himself had observed the occulta-
tion of one of the stars of Gemini by Jupiter. Seneca only speaks de-
cidedly of the transparence of the tail of comets. " We may see," says
he, "stars through a comet as through a cloud (iVa^. Qncest., vii., 18);
but we can only see through the rays of the tail, and not through tlie
body of the comet itself: non in ea parte qua aidus ipsum est spissi et
solidi ignis, sed qua rarus splendor occurrit et in crines dispergitur. Per
intervalla ignium, non per ipsos, vides" (vii., 26). The last remark is
unnecessary, since, as Galileo observed in the Saggiatore {Leltera a
Monsignor Cesarini, 1619), we can certainly see through a flame when
it is not of too gi'eat a thickness.

t Bessel, in the Astron. Nachr., 1836, No. 301, s. 204, 206. Struve,
in Recueil des M&m. de VAcad. de St. Petersb., 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 extin-
guished before the radiance of the smalLstar of the ninth or tenth mag
nitude."

COMETS. 10£

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 pos-
sess on the nature and the light of Comets are due to Arago's
polarization experiments. His polariscope instructs us re-
garding the physical constitution of the Sun and comets, indi-
cating whether a ray that reaches us from a distance of many
millions of miles transmits light directly or by reflection ; and
if the former, whether the source of light is a solid, a liquid,
or a gaseous body. His apparatus was used at the Paris Ob-
servatory in examining the light of Capella and that of the
great comet of 1819. The latter showed polarized, and there-
fore reflected light, while the fixed star, as was to be expect-
ed, appeared to be a self-luminous sun.* The existence of
polarized cometary light announced itself not only by the in-
equality 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, de-
duced 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 in-
dependent light seems very probable.

The variable intensity of light in comets can not always be

* Oil the 3d of July, 1819, Arago made the first attempt to analyze
the light of comets by polarization, on the evening of the sudden ap
pearance 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 com
et in "1835, the instrument was altered so as to give, according to Ara-
go'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 propertiea
of direct light, there being light which was reflected specularly or po-
larized, that is, coming from the sun. It can not be stated with abso
lute certainty that comets shine only with borrowed light, for bodies,
in becoming self-luminous, do tvt, on that account, lose the power of
reflecting foreign light."

E 2

106 ' COSMOS.

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 in-
creased 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 dif-
ferent degrees of distance from the Sun, appears very striking.
The physical explanation of the phenomenon can not, howev-
sr, be sought in the condensed layers of cosmical vapor occur-
ring in the vicinity of the Sun, since it is difficult to imagine,
the nebulous envelope of the nucleus of the comet to be vesic-
ular and impervious to the ether.*

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 ex-
istence of a comet of so short a period of revolution that it re
mains entirely within the limits of our planetary system, at-
taining 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
^danets) being 0*255. Encke's comet has several times, al-
though with difficulty, been observed by the naked eye, as in
Europe in 1819, and, according to Riimker, in New Holland
m 1822. Its period of revolution is about S^d 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 lyV^^i 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 diminishes 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 as

* Arago, in the Annnaire, 1832, p. 9.17-220. Sir John Herschel,
Aatrixri., $ 488.

COMETS. 107

sribed to the altered form of the small nebulous stai in the
n(5inity of the Sun, and to the action of the unequal density
of the strata of cosmical ether.^ These facts, and the inves-
tigations to which they have led, belong to the most interest-
ng results of modern astronomy, Encke's comet has been
ilie means of leading astronomers to a more exact investiga-
lion of Jupiter's mass (a most important point with reference
to the calculation of perturbations) ; and, more recently, the
X)urse of this comet has obtained for us the first determina-
tion, although only an approximative one, of a smaller mass for
Mercury.

The discovery of Encke's comet, which had a period of only
3id years, was speedily followed, in 1826, by that of another,
Biela's comet, whose period of revolution is 6;Sth 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 cer-
tain example of the orbit of a comet intersecting that of the
Earth. This position, with reference to our planet, may there-
fore 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 en-
dowed with enormous velocity may certainly exercise a con-
siderable power ; but Laplace has shown that the mass of the
comet of 1770 is probably not equal to joVo^h of that of the
Earth, estimating further with apparent correctness the mean
mass of comets as much below yooVooth that of the Earth,
or about yaVo^^ ^^^^ of the Moon.f 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 pas-
sage took place, on the 29th of October, 1832, it required a
full month before the Earth would reach the point of inter-
section 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

* Encke, in the Astronomische Nachrlchien, 1843, No. 489, s. 130-132.

t Laplace, Expos, du Syst. du Monde, p. 216, 237.

X Littrow, Beschreibende Astron., 1835, s. 274. On the inner comet
recently discoven-ed by M. Faye, at the Observatory of Paris, and whose
eccentricity is 0-.5j1, its distance at its perihelion 1*690, and its distance
at its aphelion ,5-832, see Schumacher, Astron. Nachr., 1844, No. 495.
Regarding the siipposcd identity of the comet of 1766 with the third

108 COSMOS.

Buch small bodies from the larger planets, there is 2i possibility
— supposing a meeting of these comets to occur in October — «
that the inhabitants of the Earth may witness the extraordi-
nary 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.
Events of this nature, resulting either from deflection occa-
sioned by disturbing masses or primevally intersecting orbits,
must have been of frequent occurrence in the course of mill-
ions of years in the immeasurable regions of ethereal space ;
but they must be regarded as isolated occurrences, exercising
no more general or alterative effects on cosmical relations than
the breaking forth or extinction of a volcano within the limit-
ed 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 elhptic 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 Gold-
schmidt, j^asses beyond the orbit of Jupiter, is one of the few
whose perihelia are beyond Mars. Its period of revolution is
7_2_9_ years, and it is not improbable that the form of its pres-
ent 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 iden-
tical 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

comet of 1819, see Astr. Nachr., 1833, No. 239 ; and on the identity oi
the comet of 1743 and the fourth comet of 1819, see No. 237 of the last
mentioned work.

COMETS- 1 Ofl

seventy-six years, the first in point of impDitance 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 01-
bars'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 hav-
ing recently been proved by Laugier's calculations,* that in
the Chinese table of comets, first made known to us by Ed-
ward 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.

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 respect-
ively 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 ve-
locity is only three times greater than that of water in oui
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 fur-
thest receding cosmical body with which we are acquainted
ill 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

• Laugier, in the Comptes Rendus des Stances de I Academie, 1843,
t. xvi., p. 1006,

110 COSMOS.

times that of Uranus, while a Centauri is 11,000, and 6i
Cygni 3 1,0 JO times that of Uranus, according to Bessel's le*
terminations.

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 Burck-
hardt's comet of 1770, so celebrated on account of the disturb-
ances 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 only six times
that 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 ap-
proached 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 17 th 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 possi-
ble 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 re-
visit our regions of space at short intervals — that great dis-
turbances 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 equiv-
Bilent, both as to number and variety, to the vague fears en*
tertained in early ages of the general conflagration of the world
hy Jlaming sivords, and stars \mih fiery streaming hair. As
the consolatory considerations which may be derived from the
calculus of prf babilities address themselves to reason and to

AEROLITES. Ill

meditative understanding only, and not to the imagination ol
to a desponding condition of mind, modern science has beer
acc'ised, and not entirely without reason, of not attempting tc
allay apprehensions which it has been the very means of ex
citing. It is an inherent attribute of the human mind to ex-
perience fear, and not hope or joy, at the aspect of that which
is unexpected and extraordinary.* The strange form of a large
eomet, 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 terres-
trial 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
dl-omened bodies a beneficial influence on the ripening of the
vine. The evidence yielded by experience, of which there ia
no lack in these days, when comets may so frequently be ob-
served, has not been able to shake the common belief in the
meteorological myth of the existence of wandering stars capa-
ble of radiating heat.

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 aerolites, or meteoric
stones, \ when they reach our atmosphere in a fragmentary
condition. If I should seem to dwell on the specific enumer-
ation of these bodies, and of comets, longer than the general
nature of this work might warrant, I have not done so unde-
signedly. The diversity existing in the individual character-
istics of comets has already been noticed. The imperfect
knowledge we possess of their physical character renders it

* Fries, Vorlesungenuber die Stemkvnde, 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. Qucest., vii., 17 and
21. The philosopher thus writes of the comet: " Quern nos Neronis
orincipatu IcElissimo vidimus et qui cometis detraxit infamiamy

\ [Much valuable information may be obtained regarding the origin
and composition of aerolites or meteoric stones in Memoirs on the sub-
ject, by Baumbeer and other writers, in the numbo's of Poggendorf
Annalen, from 1845 to the present time.] — Tr.

112 COSMOS.

difficulty 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 de-
grees of accuracy, or to separate the necessary from the acci-
dental. It is only with respect to measurements and compu-
tations 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 differencep.
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 cir-
cumstantiality 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 con-
dition, 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 Cu-
mana in 1799, and in North America during the years 1833
and 1834, we shall find that Jire-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 explod-
ing smoking luminous fire-balls are sometimes seen, even in
the brightness of tropical daylight,*" equaling in size the ap-

* A IVieudof mine, much accustomed to exact trigonometrical meas-
urements, was in the year 1788 at Popayan, a city which is 2^^ 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 phe"
nomeua: the Germans use the word Sternschnnppe, literally star snvff
—an expressbn well suited to the physical views of the vulgar in forma

AEROLITES 113

parent diameter of the Moon, innumerable quantities of shoot-
ing- stars have, on the other hand, been observed to fall in
forms of such extremely small dimensions that they appeal
only as moving points or phosphorescent lines.^

It still remains undetermined 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 tn 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

times, according to which, the lights in the fiiinament were said to under
go a process of sn^iffing or cleaning ; and other nations generally adopt a
term expressive of a shot ov fall of stars, as the Swedish stjernjfall, 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 na-
tives in the Mission of Vasiva use terms still more inelegant than the
German star snuff. (^Relation Historique du Voy. aux Rigions 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 Parca?, Werpeja, w^eave 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.

* 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 blend-
ing with the higher ether," expresses himself, however, generally with
much caution. He says : *' Stella cadenies sunt materia viscida inflam-
mata. Earum aliquce inter cadendum absumuntur, aliqucB vere iii terram
cadunt, pondere sua tractce. Nee est dissimile vero, quasdam conglohatas
esse ex materia faeculentd, in ipsam auram a;theream immixta : exque
aStheris regione, tractu rcctilineo, per a'erem trajicerc, ceu minutes com-
etas, occulta causa motus utrorumque.''^ — Kepler, Epit. Astron. Coper-
nicanae, t. i., p. 80.

t 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 gi-eater 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 contin-
ues longer visible. The influence exercised on shooting stars by the
character of the atmosphere is shown occasionally even in our temper-
ate zone, and at veiy small distances apart. Wartraann relates that on
the occasion of a November phenomenon at two places lying very near

114 COSMOS.

enables the eye to penetrate further into distance. Sir Alex-
ander Burnes likewise extols as a consequence of the purity of
the atmosphere in Bokhara the enchanting- and constantly-re-
curring spectacle of variously-colored shooting stars.

The connection of meteoric stones with the grander phe-
nomenon of fire-balls — the former being known to be project-
ed from the latter with such force as to penetrate from ten
to fifteen feet into the earth — has been pfoved, among many
other instances, in the falls of aerolites at Barbotan, in the
Department des Landes (24th July, 1790), at Siena (16th
June, 1794), at Weston, in Connecticut, U. S. (14th Decem-
ber, 1807), and at Juvenas, in the Department of Ardeche
(15th 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

each other, Geneva and Aux Planchettes, the number of the meteors
counted were as 1 to 7. (Wartmann, Mem. sur les Etoiles Jilantes, 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
\ight on the retina. It sometimes continues visible a whole minute,
\ind 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
vinalogy between large shootmg stars and fire-balls. Admiral Krusen-
stern saw, in his voyage round the world, the train of a fire-ball shine
for an hour after the luminous body itself had disappeared, and scarce-
ly move throughout the whole time. (Reise, th. i., s. 58.) Sir Alex-
ander Burnes gives a charming description of the transparency of the
clear atmosphere of Bokhara, which was once so favorable to the pur-
suit of astronomical observations. Bokhara is situated in 39° 43' 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 clear-
ness 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, as-
suming every color — fiery red, blue, pale, and faint. It is a nobla
country for astronomical science, and great must have been the ad-
vantage 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. Mathim., Novem., 1837, p. 447); this number is,
however, limited to five or six by that diligent observer, Olbers.
CSfjhum., Jahrb., 1838, s. 325.)

AEROLITES. 115

nave been hurled from one of these moving clouds. In less
frequent cases, as in that which occurred on the 16th of Sep-
tember, 1843, at Kleinwenden, near Miihlhausen, a large
aerolite fell with a thundering crash while the sky was clear
and cloudless. The intimate affinity between jfire-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
iiameter 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
ill equally shrouded in mystery, and we are as yet ignorant
whether the particles composing the dense mass of meteoric
itones are originally, as in comets, separated from one another
in the form of vapor, and only condensed within the fiery ball
when they becom.e luminous to our sight, or whether, in the
case of smaller shooting stars, any compact 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.*

* Oil meteoric dust, see Arago, in the Annuaire for 1832, p. 254. 1
have very recently endeavored to show, in another work {Asia Cenirale,
t. i., p. 408), how the Scythian saga of the sacred gold, which fell burn-
ing from heaven, and remained in the possession of the Golden Horde
of the Paralatae (Herod., iv., 5-7), probably originated in the vague rec-
ollection of the fall of an afercflite. The ancients had also some strange
fictions (Dio Cassius, Ixxv., 1259) of silver which had fallen from heav-
en, and with which it had been attempted, under the Emperor Seve-
rus, to cover bronze coins ; metallic iron was, however, known to exist
in meteoric stones. (Phn., ii., 56.) The frequently-recurring expres-
sion lapidibus pluit must not always be understood to refer to falls of
aerolites. In Liv., xxv,, 7, it probably refers to pumice (rapilli) eject-
ed from the volcano, Mount Albanus (Monte Cavo), which was not
wholly extinguished at the time. (See Heyne, Opuscu/a 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 myth-
ically 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 eject-
ed 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 ^schylus, the Prometheus
Delivered, every thing proceeds, however, in part of the narration, as
in a fall of aerolites, for Jupiter draws together a cloud, and causes the
** district around to be 3(1 vered by a shower of round stones " I'osido-

116 COSMOS.

We can ascertain by measurement the enormous, wonder*
fill, and wholly planetary velocity of shooting stars, fire-balls,
and meteoric stones, and we can gain a knowledge of wdiat 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, how

nius even ventured to deride the geognostic myth of the blocks and
stones. The Lygian fiekl of stones w^as, however, very naturally and
well described by the ancients. The district is now known as La Crau.
(See Guerin, Mesures Baromitriques dans les Alpes, ei M6t6orologie
d' Avignon, 1829, chap, xii., p. 115.)

* The specific weight of aerolites 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 Chaiies 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 ex-
tending from 12 to 16 miles. There are, however, ample optical caus-
es for supposing that the apparent diameter of fire-balls and shooting
stars has been very much overrated. The volume of the largest fiie-
ball yet observed can not be compared with that rf Ceres, estimating
this planet to have a diameter of only 70 English miles. (See the
generally so exact and admirable treatise, i)n the Connection of the
Physical Sciences, 1835, p. 411.) With the view of elucidating what
has been stated in the text regarding the large aerolite 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, Mon-
achi Sancti Andrece in Monte 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, temporibvs
domini Johannis Decimi pape, in anno pontificates illius 7 visa sunt sig-
na. Nam juxta tcrbem Romam lapides plurimi de cczlo cadere visi sunt.
In clvitate qvce vocatur Narnia tarn diri ac tetri, ut nihil aliiid credai-ur,-
qnam de infernalibns locis deducti essent. Nam ita ex illis lapidibus
lums omnium Tnaximus est, ut d'xidens in flumen Narnvs, ad mejisuram
iiuiiis ctibiti super aquas flicminif usque hodie videretur. Nam et ignites
faculce de ccelo plurimce omnibus in hac civitate Romani populi vises sunt,
ita ut pene terra canting eret. Alice cadentes-^'' &c, (Pertz, Monum.
Germ. Hist. Scriptores, t. iii., p. 715.) On the aerolites of iEgos Pota-
mos, which fell, accoi-ding to the Parian Chronicle, in the 78 1 Olym-
piad, see Bockh, Corp. Inscr. Graec, t. ii,, p. 302, 320, 340; also Aris-
tot., 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 Mongolian
tradition, a black fragment ol a rock, forty feet in height, fell from
heaven on a plain near the sou :ce of the Great Yellow River in West-
ern China, (Abel Remusa% in Lam6therie, Jour, de Phys., 1819. Mai
p. 264.)

arrolites. 117

ever, 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 ap-
parent diameter of which we may, in the case of the largest,
estimate that the actual diameter varies from 500 to about
2800 feet. The largest meteoric masses as yet known are
those of Otumpa, in Chaco, and of Bahia, in Brazil, described
by Rubi de CeHs as being from 7 to 7^ feet in length. The
meteoric stone of JE,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 de-
scribed as of the size of two mill-stones, and equal in weight
to a full wagon load. Notwithstanding the failure that has
attended the efibrts 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 dif-
ficult to destroy, may be found, since the region in which it
fell is now become so easy of access to European travelers.
The huge aeroUte which in the beginning of the tenth centu-
ry fell into the river at Narni, projected between three and
tbar feet above the surface of the water, as we learn from a
dc-cument 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
h£ive been broken up by the explo^on either of a fire-ball or
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 length-
ened course traversed by fire-balls through the denser strata
of the air, it seems more than improbable that these metallif-
erous stony masses, containing perfectly-formed crystals of oli-
vine, labradorite, and pyroxene, should in so short a period of
time have 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 1
Here, as in the sphere of organic life, all that appertains to
the history of development remains hidden in obscurity. Me-
teoric masses become luminous and kindle at heights which

118 COSMOS.

must be regarded as almost devoid of air, or occupied by a$
atmosphere that does not even contain yooV » o th part of oxy
gen. The recent investigations of Biot on the important phe
nomenon of twihght^ have considerably lowered the lines
which had, perhaps with some degree of temerity, been usual
ly termed the boundaries of the atmosphere ; but processes of
light may be evolved independently of the presence of oxygen,
and Poisson conjectured that aerolites were ignited far beyond
the range of our atmosphere. Numerical calculation and geo-
metrical 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. Although Halley pronounced the great fire-ball of 1 686,
whose motion was opposite to that of the earth in its orbit, f to
be a cosmical body, Chladni, 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. $ A brilliant confirmation of the cos-
mical origin of these phenomena has been afibrded by Denison
Olmsted, at New Haven, Connecticut, who has shown, on the
concurrent authority of all eye-witnesses, that during the cele-
brated fall of shooting stars on the night between the 12th

* Biot, Trait6 d'Astronomie Physique (3eme 6d.), 1841, t. i., p. 149
177, 238, 312. My lamented J"rieud Poisson endeavored, in a singulai
manner, to solve the difficulty attending an assumption of the sponta-
neous 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 usually done, the incandescence of aerolites 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, ex-
tending far beyond the mass of our atmosphere, yet subject to terres-
trial 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 im-
ponderable 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, Reck, sur
la Probability des Jugements, 1837, p. 6.)

t Philos. Transact., vol. xxix., p. 161-163.

X The first edition of Chladni's important treatise, Ueber den Ur-
sprung 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 twc
years before Lichtenberg stated, in the Gottingen Taschenbuch, tha
*' stones reach our atmosphere from the remoter regions of space.'
Comp., also, Olbers's letter to Benzenberg, 18th Nov., 1837, in Bea
senberg's Treatise on Shooting Stars, p. 18^

AEROLITES. 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 y 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 observ-
ation. 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

* Encke, in Poggend., ^nna^era, bd. xxxiii. (1834), 8.213. Arago,
in the Annuaire for 1836, p. 291. Two letters which I wrote to Ben-
zenberg, May 19 and October 22, 1837, on the conjectural precession
of the nodes in the orbit of periodical falls of shooting stars. (Benzen
berg's Sternsch., s. 207 and 209.) Olbers subsequently adopted this
opinion^ of the gradual retardation of the November phenomenon
{Astron. Nackr., 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, HisL de la
Domin. de los Arabes, p. 346.)

On the 19th of Oct., 1202, tlie stars were in motion all night. " They
fell like locusts." {Comptes Rendus, 1837, t. i., p. 294; and Froehn, in
the B^dl. de V Acad6mie de St. PHersbourg, t. iii., p. 308.")

On the 21st Oct., O.S., 1366, " die sequente post festum XL millia Vir-
ginum ah hora matutina usque ad horam primam visa sunt quasi siellcB
de coelo cadere continuo, et in tarda 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 Bo-
guslawski, in Benesse (de Horowic) de Weitmil or Weithmtil, Chron-
icon Ecclesice Pragensis, p. 389. This chronicle may also be found in
the second part of Scriptores rerum Bohemicarum, by Pelzel and Do-
browsky, 1784. (Schum., Astr. Nachr., Dec, 1839.)

On the night between the 9th and 10th of November, 1787, many fall
ing stars were observed at Manheim, Southern Germany, by Hemmer
(Kamtz, Meteor., th. iii., s. 237.)

After midnight, on the 12th of November, 1799, occurred the extra-
ordinary fall of stars at Cumana, which Bonpland and myself have de
scribed, 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, inter-
mingled with fire-balls, were seen in large numbers by Kloden, al
Potsdam. (Gilbert's Ann., bd. Ixxii., s. 291.)

On the 13th of November, 1831, at 4 o'clock in the morning, a greal
shower of falling stars was seen by Captain B6rard, 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.

la the night of the 13-14th of November, 1834, a similar fall of shoot

120 COSxMOS.

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. On the recurrence of falls of shoot-
ing 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
ihe 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, vhe
meteors came principally from one point between Perseus and
Taurus, toward the latter of which constellations the Earth
was then moving. This peculiarity of the phenomenon, mani-
fested 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 problem-
atical 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.* 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
ing 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 I'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.)

* I am well aware that, among the 62 shooting stars simultaneously
41 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 fur Freunde der Astronomie und Physik, heft
L, s. 48. Instructive Narratives for the Lovers of Astronomy and Phys-
ics.) But Olbers considered that all determinations for elevations be-
yond 120 miles must be doubtful, owing to the smallness of the parallax.

t The planetary velocity of translation, the movement in the orbit, ia
in Mercury 26-4, in Venus IP-^- and in the Earth 16-4 miles in a second.

AEROLITES. 121

of fire-balls and shooting stars, which has frequently been oh-
Berved to be opposite to that of the Earth, may be considered
as conclusive arguments against the hypothesis that aerolites
derive their origin from the so-called active lunar volcaiioes
Numerical views regarding a greater or lesser volcanic Ibrce
on a small cosmical body, not surrounded by any atmosphere,
must, from their nature, be wholly arbitrary. We may imag-
ine the reaction of the interior of a planet on its crust ten or
even a hundred times greater than that of our present terres-
trial volcanoes ; the direction of masses projected from a satel-
lite 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 seleuic ori-
gin of meteoric stones* depends upon a number of conditions

* Chladni states that an Italian physicist, Paolo Maria Terzago, on
the occasion of the fall of an aerolite at Milan in 1660, by which a Fran-
ciscan monk was killed, was the first who surmised that aerolites were
of selenic origin. He says, in a memoir entitled Musceum Septalianum^
Manfredi Septalce, Patricii Mediolanensis, industrioso labore construcium
(Tortona, 1664, p. 44), '■'^Lahant philosophorum mentes sub horum lapidnrn
ponderibus ; ni dicire velimug, lunam terram alteram, sine mundum esse,
ex cujus montibus divisa frustra in inferior em nostrum liunc orbem 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 tangei:-
tial force that would be requisite to bring to the Earth masses project-
ed 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. La-
place 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 veloc-
ity 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
geogi-aphical mile). But the measured velocity of meteoric stones av-
erages 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 La-
place asserted." (Olbers, in Schum., Jahrh., 1837, p. 52-58; and ia
Vol. I.— F

122 COSMOS.

whose accidental coincidence could alone convert a possible
into an actual fact. The view of the original existence of

Gehler, Neues Physik. Worterbuche, bd. vi., abth. 3, s. 2129-2136.) 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 present-
ed by iEtna, found that the greatest velocity of any of the stones pro-
jected fiom the crater was only 1250 feet to a second. Observations
on the Peak of Teneriflfe, 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 aerohtes, " that in all probability they
come from the depths of space," yet we see from another passage
(chap, vi., p. 233) that, being probably unacquainted with the extra-
ordinary planetary velocity of meteoric stones, he inclines to the hy-
pothesis of their lunar origin, always, however, assuming that the stones
projected from the Moon " become satellites of our Eai'th, describing
around it more or less eccentric orbits, and thus not reaching its atmos-
phere until several or even many revolutions have been accomplished."
As an Italian at Tortona bad the fancy that aerolites 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 iEgos 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,
Hiibner), accuses Anaxagoras of having predicted the fall of aerolites
from the Sun: "Celebrant Graeci Anaxagoram Clazomenium Olym-
piadis septuagesimse octavae secundo anno praedixisse cselestium littera-
rum scientia, quibus diebus saxum casurum esse e sole, idque factum
iuterdiu in Thraciae parte ad iEgos flumen. Quod si quis praedictum
credat, simul fateatur necesse est, majoris miraculi divinitatem Anax-
agorae fuisse, solvique rerum naturae intellectum, et confundi omnia, si
aut ipse Sol lapis esse aut unquam lapidem in eo fuisse credatur; de-
cidere tamen crebro non erit dubium." The fall of a moderate-sized
stone, which is preserved in the Gymnasium at Abydos, is also report"
ed to have been foretold by Anaxagoras. The fall of aerolites 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" {fivdpog didirvpog). In accord-
ance with these views of Anaxagoras, we find Euripides, in PhaUonf
terming the Sun " a golden mass ;" that is to say, a fire-colored, bright-
ly-shining matter, but not leading to the inference that aferohtes 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

AEROLITES. 123

Bmall 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 at-
mosphere, 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 bodies re-
maining invisible to us during many years and frequent revo-
lutions. The supposed phenomenon of ascending shooting
stars and fire-balls, which Chladni has unsuccessfully endeav-
ored to explain on the hypothesis of the reflection of strongly
compressed air, appears at first sight as the consequence of
some unknown tangential force propelling bodies from the
earth ; but Bessel has shown by theoretical deductions, con-
firmed by Feldt's carefully-conducted calculations, that, owing
to the absence of any proofs of the simultaneous occurrence
of the observed disappearances, the assumption of an ascent
of shooting stars was rendered wholly improbable, and inad-
missible as a result of observation.* 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 separately and in inconsiderable
numbers, that is, sporadically, or in swarms of many thou-

origin in the regions of space, as heavenly bodies which had long re-
mained invisible. Respecting this last opinion, which is that of Diog-
enes 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
afiroHtes 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., Exerc, p. 531 ; and
the passages collected by Ukert, in his Geogr. der Griechen und Romer,
ih. ii., 1, s. J 31, 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 dif-
fused 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.

* Bessel, in Schum., Astr. Nachr., 1839, No 380 mid 381, s. 222 unci
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 1790

124 COSMOS.

sands- 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 No-
vember 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 con-
stant recurrence.* Notwithstanding the great quantity of
shooting stars and fire-balls of the most various dimensions,
which, according to Kloden, 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 loeriodicity 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,P00
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,t and which, by

* Dr. Thomas Forster {^The Pocket Encyclopedia of Natural Phe-
nomena, 1827, p. 17) states that a manuscript is preserved in the hbra-
ry of Christ's College, Cambridge,^ written in the tenth century by a
monk, and entitled Ephemerides Rerum Naturalium, in which the nat-
ural phenomena for each day of the year are inscribed, as, for instance,
the first flowering of plants, the arrival of birds, &c. ; the 10th of Au-
gust is distinguished by the word " meteorodes." It was this indica-
tion, 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. (Qaetelet, Correspond. MatMm., Serie III.,
t. i., 1837, p. 433.)

t Humb., Pel. Hist., t. i., p. 519-527. EUicot, in the Transactions
of the American Society, 1804, vol. vi., p. 29. Arago makes the follow-
ing 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

a [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 Col-
lege, the learned editor of Hieroglyphics of Horapollo Nilous, Greek and English,
1840.]— Tr.

AEROLITES. 125

A comparison of the facts I had adduced, showed that tho
phenomenon had been simultaneously seen in the New Conti-
nent, from the equator to New Herrnhut in Greenland (64^
14' north latitude), and between 46*^ and 82^ longitude.
The identity of the epochs was recognized with astonishment.
The stream, which had been seen from Jamaica to Boston
(40° 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.
Musohenbroek,* 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. We shall, no doubt, in time, discover other pe-
riodically appearing streams,! probably about the 22d to the

ecliptic at about the point which our Earth annually occupies between
the 11th and 13th of November. It is a new planetary world begin-
ning to be revealed to us." {Annuaire, 1836, p. 296.) .

* 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, after the earliest observations of
Brandes (Benzenberg, uber Slernschrwppen, s. 'iiO-'m)', 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 Au-
gust, 1839, see the accurate measurements of Bessel and Erman (Schum.,
Astr. Nachr., No. 385 und 428); but on the 10th of August, 1837, tho
path does not appear to have been retrograde ; see Arago, in Comptea
Rendus, 1837, t. ii., p. 183.

t On the 25th of April, 1095, " innumerable eyes in France saw stars
falling from heaven as thickly as hail" {ut grando, nisi lucerent, pro den-
sitate putaretur ; Baldr., p. 88), and this occurrence was regarded by
the Council of Clermont as indicative of the great movement in Chris-
tendom. " (Wilken, Gesch. der Kreuzzuge, bd. i., s. 75.) On the 25th
of April, 1800, a great fall of stars was observed in Virginia and Mas
sachusetts; it was "a fire of rockets that lasted two hours." Arago
was the first to call attention to this " traln6e d'asteroides," as a recur-
ring phenomenon. {Annuaire, 1836, p. 297.) The falls of aerolites 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 tho 6th and
7th of December, 1798 (when he counted 2000 falling stars), and very

126 COSMOS.

25th of April, between the 6th and 12th of December, and,
to judge by the number of true falls of aerolites enumerated
by Capocci, also between the 27th and 29th of November, or
about the 1 7 th of July.

Although the phenomena hitherto observed appear to have
been independent of the distance from the pole, the tempera-
ture 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
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 re-
markable than at Richmond, near London. I have mentioned
in another work the singular fact observed by Admiral Wran-
gel, and frequently confirmed to me by himself,^ that when he

probably the enormous fall of aerolites that occurred at the Rij Assu,
near the village of Macao, in the Brazils, on the 11th of December, 1836.
(Brandes, Unterhalt. fur 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 a6roIites occurring between "^he 27th and 29th of November,
besides others on the 13th of Novenik/er, 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 Jan-
uary and February, and probably also with March, no periodic streams
of falling stars or aerolites 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 hith-
erto 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 differ-
ences existing between isolated comets and rings filled with asteroids,
to regard the fi'equency of these meteoric streams with less astonish-
ment than the first consideration of the phenomenon would be likely
to excite.

* Ferd. v. Wrangle, Reise Idngs der Nordkuste 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 1766j and consequently
thirty-three years (the same interval) before the great fall of stars on

AEROLITES. \ ~*1

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.

The different meteoric streams, each of which is composed
of myriads of small cosmical bodies, probably intersect our
Earth's orbit in the s*ame manner as Biela's comet. Accord-
ing 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 smaller plan-
ets 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 be-
comes visible, or the retardations of the phenomena of which
I have already spoken, indicate a regular precession or oscilla,-
tion 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 im-
mense 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 rev-
olution round the Sun, requires three days to traverse an ex-
tent 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 sel-
dom witness such glorious spectacles as those exhibited in the
November months of 1799 and 1833. The acute mind of
Olbevs 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.

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
epace of an hour enveloped in falling stars, so that the inliabitants en-
deavored to appease heaven by religious processions. {Relat. Hist,
\ i., chap, iv., p, 307; chap, x., p. 520 and 527.)

128 COSMOS.

The stream of the November asteroids has occasionally
only been visible in a small section of the Earth. Thus, foi
nistance, a very splendid meteoric shoiver 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 t\w
more eastern districts of the Earth might be passing at thf
time through a part of the meteoric ring proportionally lest
densely studded with bodies." If the hypothesis of a regulav
progression or oscillation of the nodes should acquire greatei
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 TyrtsBus, or the sec-
ond 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. Edv/ard 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 epochsf indicated. 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 Ecclesice Pragensis), be
identical with our November phenomenon, although the oc-
currence in the fourteenth century was seen in broad day-
light, we find by the precession in 477 years that this system
of meteors, or, rather, i*s common center of gravity, must de-

* From a letter to myself, dated Jan. 24th, 1838. The enormous
swarm of falling stars in November, 179.9, 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 ia
Europe, and those of 1833 and 1834 only in the United States of North
/America.

t Lettre de M. Edouard Biot a M. Quetelet, sur les anciennes appari-
tions d'Etoiles Filautes en Chine, in the Bull, de VAcadimie de Bntx
tiles, 1843, t. X., No. 7, p. 8. On the notice from the Chronicon Eo
elesicE Pragensis, see the younger Boguslawski, in Poggend., Annalen
bd. xlviii., s. 612.

AEROLITES. 129

gnribe 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 be-
tween the asteroid groups, or, according to Poisson, to the ac-
tion of the larger planets* on the form and position of thij
annulus.

The solid masses which are observed by night to fall to tht
earth from fire-balls, and by day, generally when the sky is
clear, from a dark small cloud, are accompanied by much
noise, and although heated, are not in an actual state of in-
candescence. They undeniably exhibit a great degree of gen-
eral 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 ob-
served 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 excep-
tions regarding individual points. What differences, for in-
stance, do we not find between the malleable masses of iron
of Hradschina in the district of Agram, those from the shores
of the Sisim in the government of Jeniseisk, rendered so cele-
brated by Pallas, or those which I brought from Mexico,t all
of which contain 96 per cent, of iron, from the aerolites of
Siena, in which the iron scarcely amounts to 2 per cent., or
the earthy aerolite of Alais (in the Department du Gard),
which broke up in water, or, lastly, from those of Jonzac and
Juvenas, which contained no metallic iro'n, but presented a

* " 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 cii'culation may be very diflferent 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 im«
possible at others." — Poisson, Recherches sur la Probability des Juge-
merits, p. 306, 307.

t Humboldt, Essai Politique sur la Nonv. Espagne (2de edit.), t. iii.
p. 310.

F 2

130 COSMOS.

mixture of oryctognostically distinct ciystalline components !
These differences have led mineralogists to separate these cos-
mical masses into two classes, namely, those containing nick
elliferous meteoric iron, and those consisting of fine or coarse-
ly-granular meteoric dust. The crust or rind of aerolites is
peculiarly characteristic of these bodies, being only a few
tenths of a line in thickness, often glossy and pitch-like, and
occasionally veined.* There is only one instance on record,
as far as I am aware (the aerolite of Chantonnay, in La Ven-
dee), 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 granite blocksf which I brought from the cata-
racts of the Orinoco, and which are also associated with
many other cataracts, as, for instance, those of the Nile and
of the Congo River. The greatest heat employed in our
porcelain ovens would be insufficient to produce any thing
similar to the crust of meteoric stones, whose interior re-
mains 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, sul-
phur, phosphorus, and carbon, constituting altogether nearly
one third of all the known simple bodies. jSTotwithstanding
this similarity with the primary elements into which inorganic
bodies are chemically reducible, the aspect of aerolites, 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

* 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 "lateri'
bus pluisse" seems also to refer to the burned outer surface of aerolites

^ Humb., Rel. Hist., t. ii., chap xx., p. 299-302.

AEROLITES. 131

found incorporated with aerolites, imparts to them a pecul-
iar, 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 occurrence.

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 Sterli
tamak, 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. Some few aero-
lites, 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 I'Ardeche, which re-
sembled dolorite), are the only ones, as Gustav Rose has
remarked, which have a more familiar aspect. These bodies
contain, 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 re-
placed by oxyd of tin.$ 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 compo-
nents of meteoric stones, we can not be surprised at the great
quantity of silicate of magnesia found in these cosmical bodies.
*If the aerolite of Juvenas contain separable crystals of augite
and labradorite, the numerical relation of the constituents

* Gustav Rose, Reise nach dent Ural, bd. ii., s. 202.

t Gustav Rose, iu Poggend., Ann., 182.5, bd. iv., s. 173-192. Ratn-
melsberg, Erstes Snppl. zum chem. Handwdrterbuche der Mineralogie,
1843, s. 102. "It is," says the clear-minded observer Olbers, "a re-
markable but hitherto unregarded fact, that v^^hile shells are found in
secondary and tertiary formations, no fossil meteoric stones have as yet
been discovered. May we conclude from this circumstance that pre-
vious to the present and last modification of the earth's surface no me-
teoric 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 West-
ern Carpathians (the mountain chain of Magura, at Szlanicz), both of
which are remarkably like meteoric stones. Compare Ermau, Archiv
fur viissenschaftliche Kunde von Rvssland, bd. i., s. 315, and Haidinger,
Bcricht iiher Szlanicz er Schurfe if. Ungarn.

X Berzelius, Jahresbcr., bd. xv, s. 217 und 231. Rammelsberg..
Handworferb., ai)lh. ii., 8. 25-28.

J 32 COSMOS.

render it at least probable that the meteoric masses of Cha-
teau-Renard may be a compound of diorite, consisting of horri-
blende and albite, and those of Blansko and Chantonnay com-
pounds of hornblende and labradorite. The proofs of the tel*
luric and atmospheric origin of aerolites, which it is attempt-
ed 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 New
ton and Conduit at Kensington,* I would ask why the ele-
mentary substances that compose one group of cosmical bodies,
or one planetary system, may not, in a great measure, be iden-
tical ? 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 at-
mosphere, and been formed from vaporous rings 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 meteorio
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 at-
traction, blend together under definite relations of mixture,
composing the white glittering 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 ar-
bitrary views devoid of the support of inductive reasoning.

Remarkable obscurations of the sun's disk, during whicli
the stars have been seen at mid-day (as, for instance, in the
obscuration of 1547, which continued for three days, and oc-
curred about the time of the eventful battle of Miihlberg),
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
' 203, which contirmed, the one only three, and the other six

* " Sir Isaac Newton said he took all the planets to be composed of
the same matter with the Earth, viz., earth, watei*, and stone, but vari
ously concocted." — Turner, Collections for the History of Grantham,
toniaininc; authentic Memoirs of Sir Isaac Newton, p. 172.

REROUTES. 133

hours, were supposed by Ghladni and Schnurrer to be occa
sioned 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 phe-
nomena have been observed to present a remarkable connec
tion with the regular recurrence of swarms of shooting stars
Adolph Erman has evinced great acuteness of mind in his ac-
curate investigation of the facts hitherto observed on this sub-
ject, and his researches have enabled him to discover the con-
nection of the sun's conjunction with the August asteroids on
the 7 th 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."*

The Greek natural philosophers, who were but little dis
posed to pursue observations, but evinced inexhaustible fer
tility 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,t " are, according to

* 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). Madler has examined the mean depres-
sion of temperature on the three ill-named days of May by Berlin ob-
servations ibr eighty -six years ( Verhandl. des Vereins znr Beford. des
Gartenbaues, 1834, s. 377), and found a retrogression of temperature
amounting to 2°-2 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. (Oomp. Bull, de VAcad.
Tmp. de St. PStersbourg, 1843, t. i., No. 4.)

t Plut., Viice par. in Lysandro, cap. 22. The statement of Dama-
chos (Daimachos), 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 , Egos Potamos, " which,
however, was only a small part of it," is extremely improbable, since
the direction and velocity of the fire-cloud woijld in that case of neces-
sity 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 alto-
gether certain whether Daimachos, the writer, irepl evasfieiar, was the

134 COSMOS.

the opinion of some physicists, not eruptions of the ethero'EU
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 conse-
quence of a certain intermission in the rotatory force, and by
the impulse of some irregular movement, 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." Diogenes of Apollonia* expresses himself still more
explicitly. 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
to the earth and are extinguished, as the stofiij star which fell
burning at ^gos 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 con-
verted into stars." In the Ionian school, therefore, according
to the testimony transmitted to us in the views of Diogenes
of Apollonia, aerolites 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,f

same person as Da'imachos of Plataea, who was sent by Seleucus to
India to the son of Androcottos, and who was 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 aerolites
occurred in Thrace, and whose authenticity is also doubted by Plutarch.

"* Stob., ed. Heeren, i., 25, p. 508 ; Plut., de plac. Pkilos., ii., 13.

t The remarkable passage in Plut., deplac. Philos., ii., 13, runs thus:
" Anaxagoras teaches that the surrounding ether is a fiery 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 il-
lustrate a physical dogma, the Clazomenian appears to have ascribed
the fall of the Nemaean Lion to the Peloponnesus from the Moon to
Buch a rotatory or centrifugal force. (iElian., xii., 7; Plut., de Facie
in Orbe Lunce,' c. 24 ; Schol. ex Cod. Paris., in Apoll. Argon., lib. i.,
p. 498, ed. Schaef., t. n., p. 40; Meineke, Annal. Alex., 1843, p. 85.)
Here, instead of stones from the Moon, we have an animal fi'om the
Moon! According to an acute remark of BSckh, the ancient mythol.
ogy of the Nemaean lunar lion has an astronomical origin, and is sym-

AEROLITES. 136

foiming all tilings around it in the same manner as we, ac-
cording to our present views, suppose the planets of our sys«
tern to have originated in the expanded atmosphere of anoth-
er central body, the Sun. These views must not, therefore,
be confounded with what is commonly termed the telluric or
atmospheric origin of meteoric stones, nor yet with the singu-
lar opinion of Aristotle, which supposed the enormous mass
of ^gos Potamos to have been raised by a hurricane. That
arrogant spirit of incredulity, which rejects facts without at-
tempting 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 irre-
proachable eye-witnesses — notwithstanding the important part
enacted by the Bsetylia in the meteor- worship of the ancieni .<
— notwithstanding the fact of the companions of Cortez hav-
ing seen an aerolite at Cholula which had fallen on the neigh-
boring 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 re-
mained almost wholly unheeded, and its intimate connection
with other planetary systems unknown, until attention was
drawn to the subject by Chladni, who had already gained im-
mortal 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 an-
imated 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,

bolically connected in chronology with the cycle of intercalation of the
lunar year, with the moon-wori^ip ^t Nemaea, and the games by which
it was accompanied,

136 COSMOS.

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 sat-
ellites, or that of Ceres, with the immense volume of the Sun,
all relations of magnitude vanish from our minds. The ex-
tinction 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 vi
cinity 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 uni-
verse 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. An-
other 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 lumin-
ous or calorific vibrations, or in obedience to the laws of mu-
tual 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 pob
sible 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 find-
ing that we may examine, weigh, and analyze bodies that ap-

* The following remarkable passage on the radiation of heat from
the Ijxed stars, and on their low combustion and vitality — one of Kep-
ler's many aspirations — occurs in the Paralipom. in Vitell. Astron. par*
Optica, 1604, Propos. xxxii., p. 25 : " Lucis proprium est calor, sydera
omnia calefaciunt. De syderum luce claritatis I'atio testatur, calorem
uaiversorum in minori esse proportione ad calorem imius solis, quam
ut ab homine, cujus est certa caloris mensura, uterquc simul percipi et
judicari possit. De cincindularum lucula tenuissima negare non potes,
quin cum calore sit. Vivunt enim et moventur, hoc autem non sine
calefactione per-ficitur. Sic neqne putrescentium lignorum lux suo ca«
lore destituitur ; nam ipsa puetredo quidam lentus ignis est. Inest et
stirpibus suns calor." (Compare Kepler, Epit. Astron. Copernicanve.
1618, t. i lib i p. 35.)

ZODIACAL LIGHT. ISI

pertain 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 power*
ful natural force.

Although the asteroid-swarms, on which we have been led,
from special predilection, to dwell somewhat at length, ap-
proximate to a certain degree, in their inconsiderable mas.s
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, illu-
mines 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 atmos-
phere of the summits of the Andes, at an elevation of from
thirteen to fifteen thousand feet, but even on the boundless
grassy plains, the llanos of Venezuela, and on the sea-shore,
beneath the ever-clear sky of Cumana. This phenomenon
was often rendered isspecially 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 aerial spec-
tacle 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 10^ and 14° 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 Usk in the ocean and the first manifestation of the zodi-

138 COSMOS.

acal light, although tlie night was already perfectly dark. An
hour after sunset it was seen in great brilliancy between Alde-
baran and the Pleiades ; and on the 18th of March it attained
an altitude of 39^ 5'. 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 ap-
pears to increase almost as much as at the first quarter of the
moon. Toward 1 0 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 diflicult to understand how so striking a natural phe-
nomenon should have failed to attract the attention of physi-
cists and astronomers until the middle of the seventeenth cen-
tury, or hov/ it could have escaped the observation of the Ara-
bian natural philosophers in ancient Bactria, on the Euphra-
les, and in the south of Spain. Almost equal surprise is ex-
iited by the tardiness of observation of the nebulous spots in
Andromeda and Orion, first described by Simon Marius and
tluygens. The earliest explicit description of the zodiacal
light occurs in Childrey's Britannia Baconica,* in the year

* ''There is another thing which I recommend to the observation
af mathematical men, which is, that in February, and for a little before
md 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 iliac nocte. There is no such
way to be observed at any other time of the year (that I can perceive),
Qor 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
9f 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 Baco'
nica, 1661, p. 183.) This is the first view and a simple description of
the phenomenon. (Cassini, Dicouverfe de la Lumiere C6leste qui pa*
roit dans le Zodiaque, in the Mim. de I' Acad., t. viii., 1730, p. 276.
Mairan, Traiti Phys. deVAurore Boriale, 1754, p. 16.) In this remark-
able work by Childrey there are to be found (p. 91) very clear account*
of the epochs of maxima and minima diurnal and annual temperatures,

ZODIACAL LIGHT. 139

1661. The first observation of the phenomenon may have
been made two or three years prior to this period ; but, not-
Ivithstanding, tiie 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 Dominions Cassini. The light
which he saw at Bologna in 1668, and which was observed
at the same time in Persia by the celebrated traveler Char-
din (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

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 elon-
gated at the poles (see p. 148). At the first, he believes that the Earth
was spherical, but supposes that the uninterrupted and increasing addi-
tion of layers of ice at both poles has changed its figure ; and that, as the
ice is formed from water, the quantify of that Uquid is every where
diminishing.

* Dominicus Cassini {Mem. de VAcad., t. viii., 1730, p. 188), and
Mairan {Aurore Bor., p. 16), have even maintained that the phenome-
non observed in Persia in 1668 was the zodiacal light. Delambre
{Hist, de VAstron. Moderne, t. ii., p. 742), in very decided terms, 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 (ed. de Langles, t. iv., p. 326 ; t. x., p. 97), he only applies the
term niazouk (nyzek), or "petite lance," to " tlie great and famous
comet which appeared over nearly the whole world in 1608, and whose
head was so hidden in the west that it could not be perceived in the
horizon of Ispahan" {Atlas dit Voyage de Chardin, Ta|p. iv. ; from the
observations at Schiraz). The head or nucleus of the comet was, how-
ever, visible in the Brazils and in India (Pingre, Comitogr., t. ii., p. 22).
Regardhig 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
fiteschin" (fiery spears or lances) is also applied to the rays of the ris-
ing or setting sun, in the same way as " nay^zik," according to Frey-
tag's Arabic Lexicon, signifies " stelluc 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
fi-ora April to June,, was always termed by the Italian writers of that
time il Signor Astone (see my Examen Critique de V Hist, de la G6o-
graphic, t. v., p. 80). All the hypotheses that have been advanced to
ehow that Descartes (Cassini, p. 230; Mairan, p. 16), and even Kepler
(Delambre, t. i., p. 601), were acquainted with the zodiacal hght, ap-
pear to me altogether untenable. Descartes {Pnncipes, iii., art. 130,
137) is veiy 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 extraoi-dinary 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
mora refers to the :/odi;ical light than those in which Kepler {Epit. Aa-

140 COSMOS. "

enormous tail of a comet, whose head was concealed in th«
vapory mist of the horizon, and which, from its length and
appearance, presented much similarity to the great comet ol
1843. We may conjecture, with much probability, that the
remarkable light on the elevated plains of Mexico, seen for
forty nights consecutively in 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 Az-
tec MS., the Codex Telleriano-Remends,* preserved in the
Royal Library at Paris.

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 conse-
quently can not be diffused beyond ■2^0*^^^ of Mercury's helio-
centric distance. These same laws teach us that the altitude
of the extreme boundaries of the atmosphere of a cosmicai

iron. CopernicancB, t. i., p. 57, and t. ii., p. 893) speaks of the existence
of a solar atmosphere (Umbus 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 doKovg 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 mete-
ors, and even with long-barbed comets. (Regarding Sokoc, doKta^,
doKiTtjc. see Schafer, Schol. Par. ad ApoU. Rhod., 1813, t. ii., p. 20G ;
Pseudo-Aristot., de Mundo, 2, 9 ; Comment. Alex. Joh. Pkilop. et Olymp
in Aristot. Meteor., lib. i., cap. vii., 3, p. 195, Ideier; Seneca, Nat
Qu{est., i., 1.)

* Humboldt, Monumens des Peuples Indigenes de V Amiriqne, 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 differe'nt 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 liglit
rising in the east almost to the zenith is, singularly enough, described
as " sparkling, and as if sown with stars." The description of thic»
phenomenon, which lasted forty days, can not in any way apply to vol-
canic eruptions of Popocatepetl, which lies very near, in the southeast-
ern direction. (Prescott, History of the Conquest of Mexico, vol, i., p.
284.) Later commentators have corfounded this phenomenon, which
Montezuma regarded as a warning of his misfortunes, with the " estrella
que humeava" (literally, which spring forth ; Mexican choloa, to leap of
spring forth'). With respect to the connection of this vapor with the
star Citlal Choloha (Venus) and with "the mountain of the star" (Cit>
laltepetl, the volcano of Orizaba), see my Monumens, t. ii., ]). 303.

ZODIACAL LIGHT. 14j

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 revohition
of the latter.* 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, there-
fore, 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.t

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. As

* Laplace, Expos, du Syst. du Monde, p. 270 ; M6canique C6leste,
t. ii., p. 169 and 171; Schubert, Astr., bcl. iii., $ 206.

t Arago, in the Annuaire, 1842, p. 408. Compare Sir John Her-
Bclhel's considerations on the volume and faintness of light of planetary
nebula;, in Mary Somerville's Connection of the Physical Sciences, 1835,
p. 108. The opinion that the Sun is a nebulous star, whose atmos-
phere presents the phenomenon of zodiacal light, did not originate with
Dominicus Cassini, but was first promulgated by Mairan in 1730 ( Traiti
de V Aurora Bar., p. 47 and 263 ; Arago, in the Annuaire, 1842, p.
412). It is a renewal of Kepler's views.

^ Dominicus 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 ex-
tent), 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." {M6m. de VAcad., t. viii., 1730, p. 218,
and Biot, in the Comptes Rendus, 1836, t. iii., p. 666.) Cassini be-
lieved 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 connecticn which 01
bers doubts. (Schum., Jahrb., 1837, s. 281.) Regarding the questioq
whether the place of the zodiacal light perfectly coincides with that
of the Sun's equator, see Houzeau,in Schum., Astr. Nachr., 1843, No
<92, 8. 190.

142 COSMOS.

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 appear 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.
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 remark-
able), which occurred at the time of the new moon at mid-
night in 1743, the phosphorescence was so intense that ob-
jects 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 llanos, I enjoy-
ed ample opportunities of carefully examining this phenome-
non. 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.f Must we suppose that changes are actually in
progress in the nebulous ring 1 or is it not more probable that,
although I could not, by my meteorological instruments, de-
tect 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 con-
densation 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 man*

* Sir John Herschel, Astron., § 487.

t Arago, in the Annuaire, 1832, p. 246. Several physical facts ap
pear to indicate that, in a mechanical separation of matter into its small-
est 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 miiTor have not hitherto
given any positive evidence of the presence of radiant heat in the zo-
diacal light. (Lettre de M. Matthiessen k M. Arago, in the Comptet
Rendus, t. xvi., 184.3, Avril, p. 687.)

ZODIACAL LIGHT. 143

ner ? 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 sec-
onds through the tail of a comet, w^hich appeared during tliG
continuance of the pulsations of light to be lengthened by sev-
eral degrees, and then again contracted.* As, however, the
separate particles of a comet's tail, measuring millions of miles,

* "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 trop-
ics, is of the greater 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 ; bat 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 hght is very different in different years, often for several
successive years being very bright and diffused, while in other years
it is scarcely perceptible. I think that I find the first trace of an allu-
sion to the zodiacal light in a letter fi-om Rothmann to Tycho,in which
he mentions that in spring he has observed the twilight did not close
until the sun was 2i^ 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. 1
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
most strikingly seen in the tails of large comets. We often observe,
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. Thai
these undulations, which were formerly noticed with attention by
Robert Hooke, and in more recent times by SchrSter and Chladni, do
not actually occur in the tails of the comets, but are produced by our at-
mosphere, is obvious when we recollect that the individual parts of
those tails (which are many millions of miles in length) lie at very dif-
ferent 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 coi'uscations 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 coin-
cide with the Sun's place below the horizon." (From a letter written
by Dr. Olbers to myself, and dated Bremen, March 26th, 1833.)

144 COSMOS.

are very unequally distant from the eaith, it is not possible,
according to the laws of the velocity and transmission of light,
that Ave should be able, in so short a period of time, to per-
ceive any actual changes in a cosmical body of such vast ex-
tent. These considerations in no "way exclude the reality 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 diSerences 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, accord-
ing to the most recent and acute researches on the crepuscular
theory, and of the height of the atmosphere.^ The phenom
ena of light depend upon conditions still less understood, and
their variability at twilight, as well as in the zodiacal light,
ejicite our astonishment.

We have hitherto considered that which belongs to our solar
sjstem — 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 re-
volves round the Sun in the vicinity of the Earth, and for
which, owing to its position, we may retain the name of zo-
diacal light. Every where the law of periodicity governs the
motions of these bodies, hov/ever different may be the amount
of tangential velocity, or the quantity of their agglomerated
material parts ; the meteoric asteroids which. enter our atmos-
phere from the external regions of universal space are alone
arrested in the course of their planetary revolution, and re-
tained within the sphere of a larger planet. In the solar syvS-
tem, whose boundaries determine the attractive force of the
central body, comets are made to revolve in their elliptical

* Biot, TraiU d'Astron. Physique, 3dme 6d., 1841, t. i., p. 171, 238.
and 312.

TRANSLATOllY MOTION OF THE SOLAR SYSTEM. 145

orbits at a distance 44 times greater than that of Uranus ;
nay, 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 mill-
ions 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
that appertain to and revolve around it ; but it actually ro-
tates round the common center of gravity of the whole sys-
tem, which occasionally falls within itself, that is to say, re-
mains within the material circumference of the Sun, what-
ever changes may be assumed by the positions of the planets.
A very different phenomenon is that presented by the trans-
latory 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
Telative motion of the Sun, and that of 61 Cygni, is not less
m one day than 3,336,000 geographical miles. This change
of the entire solar system would remain unknown to us, if the
admirable exactness of our astronomical instruments of meas-
urement, 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 dis-
tant shore in apparent motion. The proper motion of the star
61 Cygni, for instance, is so considerable, that it has amount-
ed 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 equi-
noxes, 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

* Bessel, in Schum., Jahrh.fur 1839, 8.51; probably four millions
of miles daily, in a relative velocity of at the least 3,336,000 miles, or
more than double the velocity of revolution of the Earth in her orbit
round the Sun.
Vol. I.— G

146

COSMOS.

of the annual motion of the fixed stars due to the translation
of the whole solar system in universal space, and to the tr.ue
proj)er motion of the stars. The difficult problem of numer-
ically separating these two elements, the true and the appar-
ent motion, has been^fiected by the careful study of the di
rection 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, con-
firmed by the calculus of probabilities, is, that our solar sys-
tem and the stars both change their places in space. Accord-
ing to the admirable researches of Argelander at Abo, who
has extended and more perfectly developed the work begun by
William Herschel and Prevost, the Sun moves in the direc-
tion 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 257° 49-7 R.A., and
28° 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 alone owing to the solar system.*

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 cer-
tainly inclines the intellectual activity, no less than the imag-
ination 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

* 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 VAcad. de St. Pitersb., 1842, t. x.,
No. 9, p. 137-139. The last-named astronomer has found, by a more
recent combination, 261° 23' R.A.-|-37° 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 259"
y R.A. -\- 34° 36' Decl.

TRANSLATORY MOTION. ^ 14T

the concatenation of causes if there were not one primordial
immovable motor."*

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 con-
stantly going on in the regions of space, afford us incontro-
vertible 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 conjec-
ture, or^mid 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 re-
volving round a center of gravity lying luithout their system
(2800 such systems having been discovered up to 1837), but
rather the extension of our knowledge regarding the funda-
mental forces of the whole material world, and the proofs we
have obtained of the universal empire of the laws of attrac-
tion, 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 ?/ of Corona, and in others to sev-
eral thousands, as in 66 oi 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 ^ of Cancer has com-
pleted more than one entire revolution. By a skillful com-
bination of the altered distances and angles of position,! the
elements of these orbits may be found, conclusions drawn re-
garding the absolute distance of the double stars from the
Earth, and comparisons made between their mass and that
of the Sun. Whether, however, here and in our solar sys-
tem, quantity of matter is the only standard of the amount
of attractive force, or whether specific forces of attraction pro-
portionate to the mass may not at the same time come into
operation, as Bessel was the first to conjecture, are questions

* Aristot., de Coelo, iii., 2, p. 301, Bekker; Phys., viii., 5, p. 256.

t Savary, in the Connaissance des Terns, 1830, p. 5G and 163. Encke,
Berl. Jahrb., 1832, s. 253, &c. Arago, in the Annitaire, 1834, p. 260,
295. John Herschel, in the Memoirs of the Astronom. Soc, vol. v., p. J 71.

148 COSMOS

whose practical solution must be left to future ages,* Whep
we compare our Sun with the other fixed stars, that is, with oth
er 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 ajyproximate 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 constella-
tion Centaur, almost 31,300 from 61 Cygni, and 41,600 from
Vega in the constellation Lyra. The comparison of the vol-
ume of the Sun with that of the fixed stars of the first mag-
nitude is dependent upon the apparent diameter of the latter
bodies — an extremely uncertain optical element. If even we
assume, with Herschel, that the a.pparent diameter of Arctu-
rus 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.t The distance of the star 61 Cygni, made known
by Bessel, has led approximately to a knowledge of the quan-
tity of matter contained in this body as a double star. Not-
withstanding 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 and the major axis of this star, it has been conjec-
tured with much probability by the great Konigsberg astron-
omer,$ " that the mass of this double star can not be very con-
siderably larger or smaller than half of the mass of the Sun."
This result is from actual measurement. The analogies de-
duce(i 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

* Bessel, Untersuchung. des Theils der planetarisclien Stdrungen,
toelche aus der Bewegumg der Sonne entstehen (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-G. The question has been raised by John Tobias Mayer, in Com-
ment. Soc. Reg. Gotting., 1804-1808, vol. xvi., p. 31-68.

t Fhilos. 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.

t Bessel, in Schura., Jahrb., 1839, s. 53.

TRANSLATORY MOTION. 149

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.* We are, however, far from having arrived at general
results regarding this subject. Our Sun, according to Arge-
lander, 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 nebulae, 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 nebulas, 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 suc-
cessively be indicated by the stars 13 and a Cephei, and 6 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 inter-
mission 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 difierent direction^ ; 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 heaven, even as on the Earth's surface, where we
see it unfolded in the germ, the leaf, and the blossom, the or-
ganisms of the vegetable world. The celebrated Spanish bot>
anist Cavanilles was the first who entertained the idea of
" seeing grass grow," and he directed the horizontal microme-
ter threads of a powerfully magnifying glass at one time to
• Madler, Astron., s. 476; also in Schum., Jahrb., 1839, a 95.

150 UOSMOS.

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 hfe of physical nature,
in the organic as in the sidereal world, all things that have
seen, 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.* The two
brilliant nodes in which the branches of the zone unite, in the
region of Cepheus and Cassiopeia, and in the vicinity of Scor-
pio and Sagittarius, appear to exercise a powerful attraction
on the contiguous stars ; in the most brilliant part, however,
between /3 and y Cygni, one half of the 330,000 stars that
have been discovered in a breadth of 5<^ 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.t The num-
ber 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 per-
ceptive powers of man, is awakened in both extremes of the
aniverse, in the celestial bodies as in the minutest animal-
cules. $ A cubic inch of the polishing slate of Bilin contains,
according to Ehrenberg, 40,000 millions of the silicious shells
of Galionellse.

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

* Sir William Herschel, in the Philos. Transact, for 1817, Part ii
p. 328. t Arago, iu the Annuaire, 1842, p. 459.

• X Sir John Herschel, in a letter from Feldhuyseu, dated Jan. 13th,
1836. Nicholl, Architecture of the Heavens, 1838, p. 22. (See, also,
Borne 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, "^art ii., p. 328.)

THE MILKY WAY. 15\

with another Milky Way, composed of nebulae. The former
constitutes, according to Sir J ohn Herschel's views, an annu-
lus, 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 op-
posite point, Cassiopeia.* An imperfectly seen nebulous spot,
discovered by Messier in 1774, appeared to present a remark-
able similarity to the form of our starry stratum and the divided
ring of our Milky Way.t The Milky Way composed of neb-
ulge 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
nebulse .of Virgo, especially in the northern wing, through
Comse 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 ag-
glomerate 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 second-
ary 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 magni-
tude,$ but appearing, when considered individually, of very
difierent magnitudes, while isolated starry clusters (starry
swarms) almost always exhibit throughout a character of
great uniformity in magnitude and brilliancy.

In whatever part the vault of heaven has been pierced by
poweiful and far-penetrating telescopic instruments, stars or
luminous nebulae are every where discoverable, the former, in

* Sir John Herschel, Astronom., $ 624 ; likewise in his Observationg
m NebulcBand Clusters of Stars (Phil. Transact. ^ 1833, Part ii.,p. 479,
fig. 25) : " We have here a brother system, bearing a real physical re
semblance and strong analogy of structure to our own."

t Sir William Herschel, in the Phil. Trang. for 1785, Part i., p. 257.
Sir John Herschel, Astron., § 616. (" The nebulous region of the heav-
ens forms a nebulous Milky Way, composed of distinct nebula?, as the
other of stars." The same observation was made in a letter he addressed
to mo in March, 1829.) % Sir John Herschel, Astron., $ 585.

152 COSMOS.

Bome cases, not exceeding the twentieth or twenty-fourth do
gree of telescopic magnitude. A portion of the nebulous vapoi
would probably be found resolvable into stars by more power
ful optical instruments. As the retina retains a less vivid im-
pression of separate than of infinitely near luminous points,
less strongly marked photometric relations are excited in the
latter case, as Aragp has recently shown.* 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 Gi-
bers, should arise, if every point throughout the depths of space
were filled by an infinite series of stars. f The assumption of
such a distribution in space is, however, at variance with ob-
servation, which shows us large starless regions of space, open-
ing?, in the heavens, as William Herschel terms them — one,
four degrees in width, in Scorpio, and another in Serpentari-
us. In the vicinity of both, near their margin, we find un-
resolvable nebulse, of which that on the western edge of the
opening in 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 at-
tractive and agglomerative forces of the marginal groups. $
" 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 Scor-
pio 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 [chasmatd)
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

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

t Olbers, on the transparency of celestial space, in Bode's Jahrb.,
1826, s. 110-121.

t " An opening in the heavens," William Hersche],in the Phil. Trans
for 1785, vol. Ixxv., Part i., p. 256. Le Fran9ais Lalande, in the Con-
naiss. des Terns pour VAn. VIU., p. 383. Arago, in the Annuaire,
1842, p. 425.

STARLESS OPENINGS. 153

translucent illuminated ether which lay beyond them.* Der-
ham, and even Huygens, did not appear disinclined to explain
in a similar manner the mild radiance of the nebulae. t

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 consider-
ation of the varying distances and the boundlessness of space,
which shows the world of phenomena, and that which con-
stitutes its causal reality, to be dependent upon the propaga-
tion 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 meas-
urements 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^-, 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 i] in Argo increase in splendor from the
second to the first magnitude. $ 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
Ught 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

* Aristot., Meteor., ii., 5, 1. Seneca, Natur. Qucest., i., 14, 2. " Coe-
lurn discessisse," in Cic, de Divin., i., 43.

t Arago, in the Annuaire, 1842, p. 429.

X In December, 1837, Sir John Herschel saw the star t] 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 Jan-
uary, 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 77 Argo.

G2

i54 COSMOS.

hour a ray of light traverses over a space of 592 milhons ol
miles. While, according to the theogony of Hesiod, the di-
mensions 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. Much, therefore, has vanished long before it
is rendered visible to us — much that we see was once differ-
ently 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 mild-
ly-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 pre-
sents us with the most ancient perceptible evidence of the ex-
istence 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 hght-illumined realms of space, " myriads
of worlds are bursting into life like the grass of the night. "f
From the regions of celestial forms, the domain of Uranus,
we will now descend to the more contracted sphere of terres-
trial 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 icombined action of heaven and earth. If we sup-
pose 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 neb-

* " 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 pjrceive it." William Herschel, in the Phil. Trans.
for 1802, p. 498. John Herschel, Astron., § 590. Arago, in the Jn-
nuaire, 1842. p. 334, 359, and 382-385.

t From ray brother's beautiful sonnet '' Freiheitund Gesetz." (Wil>
ttclm von Humboldt, Gesammelte Werke, bd. iv., s. 358, No. 25.)

I Otfried Muller, Prolegomena, s. 373.

TERRESTRIAL PHENOMENA. 168

ulcus rings, the same connection with this contiguous 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 pow-
erfully excite the light of the Sun in the atmosphere and in the
upper strata of our aii that give rise to heat-engendering elec-
tric 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 exclusive-
ly 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 in-
herent 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 ex-
panded 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 al-
most uninterrupted shocks by which it has been moved from
below, undergoes, nevertheless, great changes in the course ot
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 si-
multaneous 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 un-
known 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

156 COSMOS.

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 Plutonic forces. Even where no disruption takes
place the crystalline molecules 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 alumin-
ous 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 ani-
mal 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, contorted, and
upheaved, by mutual compression and volcanic force, leads
the reflective observer, by simple analogies, to draw a com
parison between the present and an age that has long passed
It is by a combination of actual phenomena, by an ideal en
largement 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 founda-
tion of scientific deduction.

It has been acutely remarked, " that, notwithstanding our
continual employment of large telescopes, we are less ac-
quainted 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 ob-
servation and calculation. Their physical character is, how-
ever, hidden in obscurity, for it is only in our own globe that
we can be brought in immediate contact with all the ele-
ments of organic and inorganic creation. The diversity of
the most heterogeneous substances, their admixtures and met-
amorphoses, 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 clas-
sification gradually become the objects of inductive reasoning.

I would here allude to the advantage of which I have al-

TERRESTRIAL PHENOMENA. . 157

ready spoken, possessed by that portion of physical science
whose origin is familiar to us, and is connected with our earth-
ly 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 gen-
eral 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 com-
binations, 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 het-
erogeneous nature of matter, its chemical differences, the reg-
ular farms in which its molecules combine together, whether
in crystals or granules; its relations to the deflected or de-
composed .waves of light by which it is penetrated ; to radi-
ating, 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 ob-
jects 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 per-
mitted 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.

Ii$ on the one hand, it were necessary to indicate the dif-
ference 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 space from 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
roan; in the bores and shafts formed by miners. These labors*

* In speaking of the greatest depths within the Earth reached by hu
man labor, we must recollect that there is a difference between the ah'
solute depth (that is to say, the depth below the Earth's 8Mrf**ce at th;it

158 COSM )ii.

do not extend beyond a vertical depth of somewhat more than
2000 feet (about one thu'd of a geographical mile) below the

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-w^orks at Minden, in Prussia: in June, 1844, it
was exactly 1993 feet, the absolute depth being 2231 feet. The tern
perature of the water at the bottom was 91° F., which, assuming the
mean temperature oi" the air at 49°-3, gives an augmentation of tem-
perature of 1° for every 54 feet. The absolute depth of the Artesian
well of Grenelle, near Paris, is only 1795 feet. According to the ac-
count of the missionary Imbert, the fire-springs, " Ho-tsing," of the Chi-
nese, which are sunk to obtain [carbureted] hydrogen gas for salt-boil-
ing, far exceed o*ir Artesian springs in depth. In the Chinese province
of SzU-tschuan these fire-springs are very commonly of the depth of
more than 20<,'0 feet ; indeed, at Tseu-lieu-tsing (the place of continual
flowj 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 r Associati'Mi de la Propagation de la Foi, 1829, No. 16, "p. 369.)

The relati-7e depth reached at Mount Massi, in Tuscany, south of
Vol terra, amounts, according to Matteuci, to only 1253 feet. The bor-
ing 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.) Unfortu-
nately, I do not know the exact height of its mouth above the level
of the sea. The relative depth of the Monk-wearfliouth mine, near
Newcastle, is only 1496 feet. (Phillips, in the Philas. Mag., vol. v.,
1834, p. 446.) That of the Liege coal-mine, V Esp6rance, at Seraing,
is 1355 feet, according to M. von Dechen, tiie director ; and the old
mine of Marihaye, near Val-St.-Lambert, in the valley of the Maes,
is, according to M. Gernaert, Ingenieur des Mines, 1233 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 Eselschacht, at Kuttenberg, in Bo-
hemia, a mine which can not now be worked, had the enormous abso-
lute depth of 3778 feet. (Fr. A. Schmidt, Berggesetze der dster Mon.,
abth. i., bd. i., s. xxxii.) Also, at St. Daniel and at Geish, on the Rorer-
btlhel, in the Landgericht (or provincial district) of Kitzbiihl, there
were, in the sixteenth century, excavations of 3107 feet. The plans
of the works of the Rorerbtihel are still preserved. (See Joseph von
Sperges, Tyroler Bergwerksgeschichte, s. 121. Compare, also, Hum-
boldt, Gntachten ilber Herantreibung des Meissner Stollens in die Frei'
berger Erzrevier, printed in Herder, uber den jetz begonneiien ErbstoU
len, 1838, s. cxxiv.) We may presume that the knowledge of the ex-
traordinary depth of the Rorerbtihel 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
terrte portio, quae unquam hominibus spectanda emerget aut eruitur;
cum profundius in ejus viscera, ultra . ^orescentis extremitatis corrupte-
1am. aut propter aquas in magnis fodiu. tanquam per venas scaturientes
aut propter aeris salubrioris ad vitam o erariorum sustinendam iieces-
sarii defectum, aut propter ingentes sum].tus ad tantos labores exant-
landos multasqua difficultates, ad profundi- ^res terrae partes peuetrare

TERRESTRIAL PHENOMENA. 159

ieve. of the sea, and consequently only about gyVo*^ ^^ the
Earth's radius. The crystalline masses that have been erupt-
ed 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 ena-
bled to penetrate. We are able to give in numbers the depth
of the shaft where the strata of coal, after penetrating a cer-
tain way, rise again at a distance that admits of being accu-
rately defined by measurements. These dips show that the
carboniferous strata, together with the fossil organic remains
•which they contain, mast lie, as, for instance, in Belgium,
more than five or six thousand feet* below the present level

non possuHHJS ; adeo ut quadringentas aut [quod rarissime] quingentas
orgyas in quibusdam metallis descendisse, stupendus omnibus videatur
conatus." — Gulielmi Gilberti, Colcestrensis, de Magnete Physiologia
nova. Lond., 1600, p.40.)

The absolute depth of the mines in the Saxon Erzgebirge, near Frei
bursr, 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 cele-
brated 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 deptl^of the old Kuttenberger mine (a depth great-
er 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 erects- ^
ed (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 great-
est absolute and relative depths of mines and borings. In descending
eastward from Jerusalem toward the Dead Sea, a view presents itself
to the eye, w^^ich, according to our present hypsometrical knowledge
of the surface of our planet, is unrivaled in any country ; as we ap-
proach the open ravine through which the Jordan takes its course, we
tread, with the open sky above us, on rocks which, according to the ba-
rometric measurements of Berton and Russegger, are 1385 feet below the
level of the Mediterranean. (Humboldt, Agie Centrale, th. ii., p. 323.)

* Basin-shaped curved strata, which dip and reappear at measurable
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, consequent-
ly, a great geu gnostic interest. I am indebted to that excellent geog-

ICO COSMOS,

3f the sea, and that the calcareous and the curved strata of
the Devonian basin penetrate twice that depth. If we com-
pare these subterranean basins with the summits of mountains
that have hitherto been considered as the most elevated por-
tions of the raised crust of the Earth, we obtain a distance of
37,000 feet (about seven miles), that is, about the j^jth 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 penstrate, even if the gener-
al elevation of the upper surface of the earth were equal to
the height of the Dhawalagiri .n 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, oi
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 regard-
ing 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 in-

nosist, Von Dechen, for the following obsen'ations. " 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 ab-
solute height of Mont St. Gilles certainly does not much exceed 400
feet ; the coal basin of Mens is fully 1865 feet deeper. But all these
depths are trifling compared with those w^hich are presented by tho
coal strata of Saar-Revier (Saarbrticken). I have found, after repeated
examinations, that the lowest coal stratum which is known in the neigh-
borhood of Duttweiler, near Bettingen, northeast of Saarlouis, must de-
scend tc 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 De-
vonian strata. This coal-field is therefore sunk as far below the sur-
face of the sea as Chimborazo is elevated above it — at a depth at which
the Earth's temperature must be as high as 435° F. Hence, from the
highest pinnacles of the Himalaya to the lowest basins containing tho
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.

GEOGRAPHICAL DISTRIBUTION. 161

crease of density from the upper surface to the center of th«
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 eruptions, and even in producing
alterations in the level of the sea.* Large plains and vari-
ously indented continents are raised or sunk, lands are sep
arated 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 straMfied and
fixed, or broken up into floating banks. The boundaries of
sea and land, of fluids and solids, are thus variously and fre-
quently changed. Plains have undergone oscillatory move-
ments, being alternately elevated and depressed. After the
elevation of continents, mountain chains were raised upon long
fissures, mostly parallel, and, in that case, probably cotem-
poraneous ; 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 erup-
tions 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 Himalaya to the regions of perpetual snow, have occa-
sioned new compositions and new textures in the rocky masses,
and have altered the strata which had been previously de-
posited from fluids impregnated with organic substances. We
here trace the series of formations, divided and superposed ac-
cording to their age, and depending upon the changes of con-
figuration 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 in-
timate connection and reciprocal action with the encircling

* [See Daubeney On Volcanoes, 2d edit., 1848, p. 539, &c., on the so^
called mud volcanoes, and the reasons advanced in favor of adopting the
term " salses to designate these phenomena.] — Tr.

162 COSMOS.

sea, in which org-aiiic life is almost entirely limited to the ani-
mal worlds The liquid element is again covered by the at-
mosphere, an aerial ocean in which the mountain chains and
high plains of the dry land rise like shoals, occasioning a va-
riety 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 de-
clivities.

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 rela-
tive numerical distribution over the Earth's surface, are con-
ditions afiected 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, ti/ the soil, are supplanted and ruined
by the dangerous vicinity of others more civilized than them-
selves, 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 man-
ner the consideration of the form of the Earth and the inces-
sant 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 por-
tions 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 cul-
ture. 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
requiren\cnt for cosmical presentation awakened in me by the

FIGURE OF THE EARTH. 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."*

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 crys-
talline, 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 revolu-
tion gives evidence of having once been a soft or fluid mass.
Thus the Earth's compression constitutes one of the most an-
cient geognostic events, as every attentive reader of the book
of nature can easily discern ; and an analogous fact is pre-
sented in the case of the Moon, the perpetual direction of whose
axes toward the Earth, that is to say, the increased accumula-
tion of matter on that half of the Moon which is turned to-
ward us, determines the relations of the periods of rotation and
revolution, and is probably cotemporaneous with the earliest
epoch in the formative history of this satellite. The mathe-
matical 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 difierent from
that true physical surface which is affected by all the acci-
dents and inequalities of the solid parts. f The whole figure
of. the Earth is determined when we know the amount of the

* Plato, Ph(tdo, p. 97. (Arist., Metaph., p. 985!) Compare Hegel,
Philosophie der Geschichte, 1840, s. IG.

t Bessel, Allgemeine Betrachtungen uher Oradmessungen nach astro-
nomisch-geoddtischen Arbeiten, at the conclusion of Bessel and Baeyer,
Gradmessung in Ostpreussen, s. 427. Regarding the accumulation ol'
matter on the side of the Moon turned toward us (a subject noticed
in an earlier part 'jf the text), see Laplace, Expos, dii Syst. du Monde,
p. 308.

164 COSMOS.

compression at the poles and the equatorial diameter ; in or*
der, however, to obtain a perfect representation of its form >*
is necessary to have measurements in two directions, perpen-
dicular 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 ac-
quainted with the size of our globe, which Pliny named " a
'point in the immeasurable universe."* 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 tc
nature of these partial results. The conclusion to be drawr,
from the increase of forces of attraction (in the direction froix.
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,
PhilosophicB Naturalis Principia, that the compression of the
Earth, as a homogeneous mass, was -aio^h- Actual meas-

* Pliu., ii., G8. Seneca, Nat. Qucest., Prcef., c. ii. '* El mundo ea
poco" (the Earth is small and narrow), writes Columbus from Jamaica
to Queen Isabella on the 7th of July, 1503 ; not because he entertained
tho 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 VHist. de la Geogr. du ISme Siecle, t. i., p. 83, and
t. ii., p. 327, where I have shown that the opinion maintained by De-
lisle, Fr6ret, and Gosselin, that the excessive differences in the state-
ments 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 Fer-
rer, in a proposition regarding the determination of the line of demark-
ation of the papal dominions.

+ 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, consequent-
ly, to the investigation of the true figure of the Earth." Although Cas-
sini did not announce the amount of the compression of Jupiter (y^-gth)
till 1691 {Anciens Mimoires dc V Acad, des Sciences, t. ii., p. 108), yet
we know from Lalande {Astron., 3me 6d., 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 awai-e of the compression of Jupiter before the year 1666, and
therefore at least twenty-one years before the publication of Newton's
Principia.

FIGUKK OF THE EAB PH. 165

arements, 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 g^oth.

Three methods have been employed to investigate the curv-
ature of the Earth's surface, viz., measurements of degrees,
oscillations of the pendulum, and observations of the inequal-
ities in the Moon's orbit. The first is a direct geometrical
and astronomical method, while in the other two we determ-
ine from accurately observed movements the amount of the
tbrces 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 strik-
mg 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 measure-
ments 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 ob-
ject 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

* According to Bessel's examination of ten measurements of degrees,
in which the error discovered by Puissant 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 w^hich 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 -^-^d ; the length of a mean degree of
the meridian, 57 013109 toi"ses, or 364,596 feet, with an error of -f

166 COSMOS.

of ^^g-th. In accordance with this, the polar radius is 1 0,938
toises (69,944 feet), or about 11-i- miles, shorter than the equa-
torial 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 gravi-
tation, to somewhat more than 4^th times tlie height of
Mont Blanc, or only 21 times the probable height of the
summit of the Dhawalagiri, 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 elhpticity as the measurements
of degrees, viz., -j-^th. The results yielded by the oscillation
of the pendulum give, on the whole, a much greater amount
of compression, viz., 2T8"th.*

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 measure-
ments of degrees varied between g^gd and 2^7*^; thus Walbeck {De
Forma et Magnitudine telluris in demensis arcubus Meridiani dejiniendis,
1819) gives 3o|iith : Ed. Schmidt (LehrbuchderMathem.undPht/s. Geo-
graphic, 1829, s. 5) gives g^^l^^d, as the mean of seven measures. Re-
specting the influence of great diflerences of longitude on the polar
compression, see^Bibliotheque Universelle, t. xxxiii., p. 181, and t.xxxv.,
p. 56 ; likevk'ise Connaissance des Term, 1829, p. 290. From the hmar
inequalities alone, Laplace {Exposition du Syst. du Monde, p. 229) found
it, by the older tables of Biirg, to be gT^Vi^h ; and subsequently, from
the lunar observations of Burckhardt and Bouvard, he fixed it at -^L -th
(Mdcanique Celeste, t. v., p. 13 and 43).

* The oscillations of the pendulum give ^^^^.-^th as the general result
of Sabine's great expedition (1822 and 1823, from the equator to 80^
north latitude) ; according to Freycinet, _,i^_d, exclusive of the experi-
ments instituted at the Isle of France, Guam, and Movv^i (Mawi); ac-
cording to Forster, -Tr^Q.-s^^^ '» according to Duperrey, -^gVi^^ ' ^"*^ ^^'
cording to Ltitke (Partie Nautique, 1836, p. 232), g^^th, calculated
fium eleven stations. On the other hand, Mathieu ( Connaiss. des Temps,
1816, p. 330) fixed the amount at ^^^-d, from observations made be-
tween Formentera and Dunkirk ; and Biot, at g^rtfij from observations
between Formentera and the island of Unst. Compare Baily, Report
on Pendulum Experiments, in the Memoirs of the Royal Astronomical
Society, vol. vii., p. 96 ; also Borenius, in the Bulletin de V Acad, de St.
Pitersbourg, 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 fes 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 Boug\iier,
La Condamine, and Godin. On the beautiful marble tablet which ex-
ists, as yet uninjured, in the old Jesuits' College at Quito, I have mynelf
read the inscription, Penduli simplicis cBquinoctialis iintus miniiti secundi

FIGURE OF THE EARTH. 167

Galileo, who first observed when a boy (having, probably,
suffered his thoughts to wander from the service) that the
heiglit of the vaulted roof of a church might be measured by
the time of the vibration of the chandeliers suspended at dif-
ferent altitudes, could hardly have anticipated that the pendu-
lum 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 sec-
onds 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 con-
tinental mountain chains,! dense masses of basalt and mela-

archetypus, mensurce naturalis exemplar, utinam universalis ! From an
observation made by La Condamine, in his Journal du Voyage d VEqua-
teur, 1751, p. 163, regarding parts of the inscription that were not filled
up, and a slight difference between Bougner and himself respecting the
numbers, I was led to expect that I should find considerable discrepan-
cies between the marble tablet and the inscription as it had been de-
scribed in Paris ; but, after a careful comparison, I merely found two
perfectly unimportant differences: "ex arcu graduum 3i^" instead of
" ex arcu graduum plusquam triura," and the date of 1745 instead of
1742. The latter circumstance is singular, because La Condamine re-
turned 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 (VOb-
serv. Astron., t. ii., p. 319-354.) Nouet's latitudes, engraved on Egyp-
tian monuments, offer a more recent example of the danger presented
by the grave perpetuation of false or careless results.

* Respecting the augmented intensity of the attraction of gravitation
in volcanic islands (St. Helena, Ualan, Fernando de Noronha, Isle of
France, Guam, Mowi, and Galapagos), Rawak (Liitke, p. 240) being
an exception, probably in consequence of its proximity to the high
land of New Guinea, see Mathieu, in Delambi'e, Hist, de VAstronomie, au
I8we Siecle, p. 701.

t 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 MSridienne, t. iii., p. 548;
Biot, in the M6m. de VAcadimie 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 dependent on the general size of
their mass, but (much more), in the opinion of Elie de Beaumont (Rech.
sur les R6vol. de la Surface du Globe, 1830, p. 729), on the rocks of
meJaphyre and serpentine, wl' rh have eleviited tho cliaiu. On the

168 COSMOS.

phyrc instead of cavities, render it difEc:ilt, notwithstanding
the admirable simphcity of the method, to arrive at any great
result regarding the figure of the Earth from observation of
the oscillations of the pendulum. 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 raiore perfect knowledge of the mo-
tion of the latter will enable us reciprocally to draw an infer-
ence 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 ei^abled 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."

declivity of Ararat, which with Caucasus may be said to lie in'the cen-
ter 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, difierences 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'v.n Arc du Parallele Moyen, t. ii., p. 347 ; Effemeridi Astron. di Mi-
lano, 1842, p. 57.) The latitude of Milan, deduced from that of Berne,
according to the French triangulation, is 45° 27' 52", while, according
to direct astronomical observations, it is 45° 27' 35". As the perturba-
tions extend in the plain of Lombardy to Parma, which is far south of
tlie Po (Plana, Op6rat. 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 ana-
lytical expressions given by Hossard and Rozet, in the Comftes Rendus,
t. xviii., 1844, p. 292, and compare them with Poisson, Traiti de M6
sanique (2me ed.), t. i., p. 482. The earliest observations on the in
riueuce 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 curva-
ture 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 froa
gr*at depths, through open clefts, and approached near the surface.
■ Laplace, Expos, du Syst. du Monde, p. 231.

DENSITV OF THE EARTH. 169

The compression which may be inferred from lunar inequali-
ties affords an advantage not yielded by individual measure-
ments 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 indi-
vidual 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
to 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 plum-
met have here likewise served to determine the mean density
of the Earth, either in connection with astronomical and geo-
detic 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 horizon-
tally vibrating pendulum for the measurement of the relative
density of neighboring strata. Of these three methodsf the

* La Caille's pendulum measurements at the Cape of Good Hope,
which have been calculated with much care by Mathieu (Delambre.
Hist, de VAstron. au ISme Steele, p. 479), give a compression of g^y.^th ;
but, from several comparisons of observations made in equal latitudes
n 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 south-
ern hemisphere is greater than that of the northern. (Biot, in the MSm.
de V Acad, des Sciences^ t. viii., 1829, p. 39-41.)

t The three methods of observation give the followin°[ results: (I.) by
the deflection of the plumb-line in the proximity of the Shehallieu
Mountain (Gaelic, Thichallin) in Perthshire, 4-713, as determined by
Maskelyne, Hutton, and PJayfair (1774-1776 and 1810), according to 'a
method that had been proposed by Newton; (2.) by pendulum vibra
Vol. I — H

i70 COSMOS.

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. According to the most recent experi-
ments 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
that of pure water. As, according to the nature of the min-
eralogical 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 elhptical un-
equally compressed layers of the interior must greatly increase
m 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

tions on mountains, 4-837 (Carlini's observations on Mount Cenis com
pared with Biot's observations at Bordeaux, Effemer. Astron. di Milano,
1824, p. 184); (3.) by the torsion balance used by Cavendish, vv^ith an
apparatus originally devised by Mitchell, 5-48 (according to Button's
revision of the calculation, 5"32, and according to that of Eduard
Schmidt, 5-52; Lekrbuck der Math. Geographic, 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 lati-
tude of Freiberg (SO'^ 55'), becomes changed to 5*44. The employ
ment of cast iron instead of lead has not presented any sensible differ
euce, or none exceeding the limits of errors of observation, hence dis»
closing no traces of magnetic influences. (Reich, Versuche uber die mitt-
lere Dichtigheit der Erde, 1838, s. 60, 62, and 66.) By the assumptioc
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, name-
ly, 4-761 (Laplace, Mican. Celeste, t. v., p. 46), or 4-785. (Eduard
Schmidt, Lehrb. d€r Math. Geogr., bd. i., $ 387 und 418.) On Hailey'a
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. 57 * ) provision might in
•ome mannor be contrived."

DENSITY OF THE EARTH. 171

entirely opposite views regarding the nature of the interior of
the globe. It has been computed at what depths liquid oi
even gaseous substances would, from the pressure ojp their
own superimposed strata, attain a density exceeding that of
platinum or even iridium ; and in order that the compression
which has been determined within such narrow limits migh*
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 82° 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 pub-
licly and frequently invited by Captain Symmes to enter upon
this subterranean expedition : so powerful is the morbid in-
clination of men to fill unknown spaces with shapes of won-
der, 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-ro
tating nucleus occasions by its position the diurnal and an
nual changes of magnetic declination. It has thus been at
tempted in our own day, with tedious solemnity, to clothe in
a scientific garb the quaintly-devised fiction of the humorous
Ilolberg.*

* [The work refeired to, oue of tlie wittiest productions of the learned
Norwegian satirist and dramatist Holberg, was written in Latin, and
first appeared under the following title : Nicolai Klimii iter subterro'
neum novum tellvris theoriam ac historiam quintce monarchice adhuc no*
his incognita exhibens e hibliotheca b. Abelini. Hafnia: et Lipsice sumL
Jac. Freuss, 1741. An admirable Danish translation of this learned
but severe satire on the institutions, morals, and manners of the inhab-
itants of the upper Earth, appeared at Copenhagen in 1789, and was
entitled Niels Klira's underjordiske reise ved Ludwig Holberg, oversai

172 COSMOS.

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
planetary 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 soHdification of this
fluid, which is commonly conjectured to have been gaseous
and primordially heated to a very high temperature, an enor-
mous 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 molt-
en 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 cal-
culation, expressly perfected for this class of investigations,*

efter 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.

* Here we must notice the admirable analytical labors of Fourier,
Biot, Laplace, Poisson, Duhamel, and Lame. In his Thiorie MathSma-
tiqufi do la Chaleur, 1835, p. 3, 428-430, 436, and 521-524 (see, also,
De la Rive's abstract in the Bibliotheque Universelle de Geneve), Pois-
son 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 sun'ounding the Earth, the parts which were first solidified
Bunk, 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 ge-
ometer 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

INTERNAL HEAT OF THE EARTH. 173

regaiding the motion of heat in homogeneous metaUic spho.
roids, must be applied with much caution to the actual char-
acter of our planet, considering our present imperfect knowl-
edge 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. It is with the greatest difficulty that our pow-
ers of comprehension can conceive the boundary line which di-
vides 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 attract-
ing 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° foi every 54*5 feet. If this increase can be reduced

are of a very different temperature from others, in consequence of stel-
lar 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., b.
93-100.

174 COSMOS.

to arithmetical relations, it will follow, as I have already ob-
served,* 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
Himalaya.

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 sea-
sons of the year. The second is likewise an effect of the Sun,
although extremely slow : a portion of the heat that has pene-
trated 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 trans-
mission is the slowest of all, and is derived from the secular
cooling of the globe, and from the small portion of the primi-
tive heat which is still being disengaged from the surface.

* 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, accoi'ding
to Auguste de la Rive and Marcet, notwithstanding that the mouth oi
the boring is 1609 feet above the level o!f 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,
»iud 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 I'Observatoire
beneath it: the mean temperature of the former is 51°*5, and of the
latter 53°-3, the difference being l^S for 92 feet, or 1° for 51-77 feet.
(Poisson, Thiorie 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,
;he thermometer standing there has risen very nearly 0*^*4. Although
rU Artesian wells there are sometimes slight errors from the lateral
permeation of water, these errors are less injurious to the accuracy of
conchisions 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° to 76-3
feet. (Reich, Beob. uher die Temperatnr des Oesteins in verschieden en
Tiefen, 1834, s. 134.) Philhps, 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° to 59-06 feet, a result almost identical with that found by Arago
in the Puits de Grenell.

MEAN TEMPERATURE OP THE EARTH. 175

This loss experienced by the central heat must have been verj
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 conduct-
ing 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 tempera-
ture at very different periods of time. The further they are
removed from the surface, the smaller is this difference be-
tween the extremes. In the latitudes of our temperate zone
(between 48^ and 52°), 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 cli-
mates 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, cer-
tain determination of the mean temperature of the air of
different places.^ 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 tem-
perature 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,
Bcarcely 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

* Bo«s3^ingault, Sur la Profondeur a laquelle se trouve la Couche d»
T^'i'^rature invariable entre les Tropiques, in the Annalet de Chimin
»e M Pkttstque, t. liii., 1833, p. 225-247.

176 COSMOS.

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 unal-
tered 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 relatiolas 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
movement of the heavens to the thermic condition of our
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 rota-
tory 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, smcQ 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, there-
fore, taking the extremest limits, diminished as much as a^gth
of a degree of Fahrenheit.*

This invariability of form presupposes also a great invaria-
bility in the distribution of relations of density in the interior
of the globe. The translatory movements, which occasion
the eruptions of our present volcanoes and of ferruginous lava,
and the filhng up of previously empty fissures and cavities
with dense masses of stone, are consequently only to be re-
garded as slight superficial phenomena affecting merely one
portion of the Earth's ci:ust, which, from their smallness
when compared to the Earth's radius, become wholly insig-
nificant. ^

I have described the internal heat of our planet, both with
reference to its cause and distribution, almost solely from the
results of Fourier's admirable investigations. Poisson doubts
the fact of the uninterrupted increase of the Earth's heat

* Laplace, Exp. du Sijst. du Monde, p. 229 and 263 ; M6caniqm
CilMte, t. v., p. 18 and 72. It should be remarked that the fraction
g-i^th of a degree of Fahrenheit of the mercurial thermometer, giv^u in
the text as the limit of the stability of the Earth's temperature siuc6
the days of Hipparchus, rests on the assumption that the dilatation of
the substances of which the Earth is composed is equal to that of glass,
that is to say, y^.-fTo-o*^ ^^^ ^°' Regarding this hypotb 3sis, see Ara°:ia
in the AnnuaWe for 1834, p. 177-190.

TERRESTRIAL MAGNETISM. 177

from the surface to the center, and is of opinion that all heat
has penetrated from without inward, and that the tempera-
ture of the globe depends upon the very high or very low
temperature of the regions of space through which the solar
system has moved. This hypothesis, imagined by one of the
most acute mathematicians of our time, has not satisfied phys-
icists or geologists, or scarcely, indeed, any one besides its au-
thor. But, whatever may be the cause of the internal heat
of our planet, and of its limited or unUmited increase in deep
strata, it leads us, in this general sketch of nature, through
the intimate connection of all primitive phenomena of matter,
and through the common bond by which molecular forces are
united, into the mysterious domain of magnetism. Changes
of temperature call forth magnetic and electric currents. Ter-
restrial magnetism, whose main character, expressed in the
three-fold manifestation of its forces, is incessant periodic va-
riabihty, is ascribed either to the heated mass of the Earth
itself,* or to those galvanic currents which we consider as
electricity in motion, that is, electricity moving in a closed
circuit.!

The mysterious course of the magnetic needle is equally
affected by time and space, by the sun's course, and by changes
of place on the Earth's surface. Between the tropics, the
hour of the day may be known by the direction of the needle
as well as by the oscillations of the barometer. It is affected
instantly, but only transiently, by the distant northern light
as it shoots from the pole, flashing in beams of colored light
across the heavens. When the uniform horary motion of the
needle is disturbed by a magnetic storm, the perturbation
manifests itself simultaneously, in the strictest sense of the
word, over hundreds and thousands of miles of sea and land,
or propagates itself by degrees, in short intervals of time, in

* William Gilbert, of Colchester, whom Galileo pronounced " great
vo a degree that might be envied," said " magnus magnes ipse est globus
terrestris." He ridicules the magnetic mountains of Frascatori, the great
cotemporary of Columbus, as being magnetic poles : " rejicienda est
vulgaris opinio de montibus magneticis, aut rupe aliqua magnetica, aut
polo phantastico a polo mundi distante." He assumes the declination
of the magnetic needle at any given point on the surface of the Earth
to be invariable (variatio uniuscujusque loci constans est), and refers
the curvatures of the isogenic lines to the configuration of continents
and the relative positions of sea basins, which possess a weaker mag
netic force than the solid masses rising above the ocean. (Gilbert, de
Magnets, ed. 1G33, p. 42, 98, 152, and 155.)

t Gauss, Allgemeine Theorie des Erdmagnetismus, in the Resultate aui
dfiti Beob. des Magnet. Vereins, 1838, s. 41, p. 56.

H 2

178 COSMOS.

every direction over the Earth's surface.^ In the former case,
the simultaneous manifestation of the storm may serve, with-
Jn certain limitations, like Jupiter's satellites, fire-signals, and
well-observed falls of shooting stars, for the geographical
determination of degrees of longitude. We here recognize
with astonishment that the perturbations of two small mag-
netic needles, even if suspended at great depths below the
surface, can measure the distances apart at which they are
placed, teaching us, for instance, how far Kasan is situated
east of Gottingen or of the banks of the Seine. There are
also districts in the earth where the mariner, who has been
enveloped for many days in mist, without seeing either the
sun or stars, and deprived of all means of determining the
time, may know with certainty, from the variations in the
inclination of the magnetic needle, whether he is at the north
or the south of the port he is desirous of entering.f

* There are also perturbations which are of a local character, and
do not extend themselves far, and are probably less deep-seated. Some
years ago I described a rare instance of this kind, in which an extraor-
dinary disturbance was felt in the mines at Freiberg, but was not per
ceptible at Berlin. {Lettre de M. de Humboldt a Son Altesse Royale le
Due de Sussex sur les moyens propres a perfectionner la Connaissance
in MagiUtisme Terrestre, in Becquerel's Traiti Expirimental de V Elec-
triciti, t. vii., p. 442.) Magnetic storms, which were simultaneously
^elt from Sicily to Upsala, did not extend from Upsala to Alteu. (Gauss
and Weber, Resultate des Magnet. Vereins, 1839, $ 128; Lloyd, in the
Comptes Rendus de VAcad. des Sciences, t. xiii., 1843, Sem. ii., p. 725
and 827.) Among the numerous examples that have been recently
observed, of perturbations occurring simultaneously and extending over
wide portions of the Earth's surface, and which are collected in Sabine's
important work {Observ. on Days of unusual Magnetic Disturbance,
1843), one of the most remarkable is that of the 25th of September,
1841, which was observed at Toronto in Canada, at the Cape of Good
Hope, at Prague, and partially in Van Diemen's Land. The English
Sunday, on which it is deemed sinful, after midnight on Saturday, to
register an observation, and to follow out the great phenomena of crea-
tion in th«?i'' perfect development, interrupted the observations in Van
Diemen's Land, where, in consequence of the difference of the longi-
tude, the magnetic storm fell on the Sunday. {Observ., p. xiv., 78, 85,
and 87.)

t I have described, in Lametherie's Journal de Physique, 1804, t.
lix., p. 449, the application (alluded to in the text) of the magnetic in-
clination to the determination of latitude along a coast running north
and south, and which, like that of Chili and Peru, is for a part of the
year enveloped in mist {garua). In the locality I have just mentioned,
this application is of the greater importance, because, in consequence
of the strong current running northward as far as to Cape Pareiia, navi«
gators incur a great loss of time if they approach the coast to the north
of the haven they are seeking. In the South Sea, from Callao de Lima
harbor to Truxillo, which ditFer from each other in latitude by 3° 57'

TERRESTRIAL MAGNETISM. 179

When the needle, by its sudden disturbance in its horary
course/ indicates the presence of a magnetic storm, we are
still unfortunately ignorant whether the seat of the disturbing
cause is to be sought in the Earth itself or in the upper re-
gions of the atmosphere. If we regard the Earth as a true
magnet, we are obliged, according to the views entertained
by Friedrich Gauss (the acute propounder of a general theory
of terrestrial magnetism), to ascribe to every portion of the
globe measuring one eighth of a cubic meter (or Sy^-ths of a
French cubic foot) in volume, an average amount of magnet-
ism equal to that contained in a magnetic rod of 1 lb. weight.*
If iron and nickel, and probably, also, cobalt (but not chrome,
as has long been believed), t are the only substances which
become permanently magnetic, and retain polarity from a
certain coercive force, the phenomena of Arago's magnetism
of rotation and of Faraday's induced currents show, on the
other hand, 'that all telluric substances may possibly be made
transitorily magnetic. According to the experiments of the

I have observed a variation of the magnetic inclination amounting to
9° (centesimal division) ; and from Callao to Guayaquil, w^hich differ in
latitude by 9° 50', a variation of 23°-5. (See ray Relat. Hist., t. iii.,
p. 622.) At Guarmey (10° 4' south lat.), Huaura (11° 3' south lat.),
and Chancay (11° 32' south lat.), the inclinations are 6°-80, 9°, and
10°-35 of the centesimal division. The determination of position by
means of the magnetic inclination has this remarkable feature connected
with it, that where the ship's course cuts the isoclinal line almost per-
pendicularly, it is the only one that is independent of all determination
of time, and, consequently, of observations of the sun or stars. It is
only lately that I discovered, for the first time, that as early as at the
close of the sixteenth century, and consequently hardly twenty years
after Robert Norman had invented the inclinatorium, William Gilbert,
in his great work De Magnets, proposed to determine the latitude by
the inclination of the magnetic needle. Gilbert {Physiologia Nova de
Magneie,' \ih. v., cap. 8, p. 200) commends the method as applicable
" a6re caliginoso." Edward Wright, in the introduction which he
added to his master's great work, describes this proposal as " worth
much gold." As he fell into the same error with Gilbert, of presum
ing that the isoclinal lines coincided with the geographical parallel
circles, and that the magnetic and geographical equators were identic-
al, he did not perceive that the proposed method had only a local and
very limited application.

* Gauss and Weber, Resultate des Magnet. Vereins, 1838, $ 31, s. 146.

t According to Faraday (London and Edinburgh Philosophical Maga-
zine, 1836, vol. viii., p. 178), pure cobalt is totally devoid of magnetic
power. I know, however, that other celebrated chemists (Henirich
Rose and W6hler) do not admit this as absolutely certain. If out of
two carefully-purified masses of cobalt totally free from nickel, one ap-
pears altogether non-magnetic (in a state of equilibrium), I think it
probable that the other owes its magnetic property to a want of purity )
ind this opinion coincides with Faraday's view.

180 COSMOS.

lirst-mentioned of these great physicists, water, ice, glass, and
carbon affect the vibrations of the needle entirely in the same
manner as mercury in the rotation experiments.* Almost all
substances show themselves to be, in a certain degree, mag-
netic when they are conductors, that is to say, when a current
of electricity is passing through them.

Although the knowledge of the attracting power of native
iron magnets or loadstones appears to be of very ancient date
among the nations of the West, there is strong historical evi-
dence in proof of the striking fact that the knowledge of the
directive power of a magnetic needle and of its relation to
terrestrial magnetism was peculiar to the Chinese, a people
living in the extremest eastern portions of Asia. More than
a thousand years before our era, in the obscure age of Codrus,
and about the time of the return of the Heraclidse to the Pel-
oponnesus, the Chinese had already magnetic carriages, on
which the movable arm of the figure of a marl continually
pointed to the south, as a guide by which to find the way
across the boundless grass plains of Tarlary ; nay, even in the
third century of our era, therefore at least 700 years before
the use of the mariner's compass in European seas, Chinese
vessels navigated the Indian Oceanf under the direction of
magnetic needles pointing to the south. I have shown, in
another work, what advantages this means of topographical di-
rection, and the early knowledge and application of the mag-
netic needle gave the Chinese geographers over the Greeks
and Romans, to whom, for instance, even the true direction
of the Apennines and Pyrenees always remained unknown. $

The magnetic power of our globe is manifested on the ter-
restrial surface in three classes of phenomena, one of which
exhibits itself in the varying intensity of the force, and the
two others in the varying direction of the inclination, and in

* Arago, in the Annates de Ckimie, t. xxxii., p. 214; Brewster, Treat-
ise on Magnetism, 1837, p. Ill; Baumgartner, in the Zeitschrift fiif
Phys. und Mathem., bd. ii., s. 419.

t Humboldt, Examen Critique de VHist. de la Giographie, t. iii., p. 36.

X Asie Centrale, t. i., Introduction, p. xxxviii.-xlii. "The Western
nations, the Greeks and the Romans, knew that magnetism could bo
communicated to iron, and that that metal would retain it for a length oj
time. (" Sola ha^c materia ferri vires, a magnete lapide accipit, retinet-
que longo tempore.'" Plin., xxxiv., 14.) The great discovery of the ter-
restrial directive force depended, therefore, alone on this, that no one
in the West had happened to observe an elongated fragment of magnet-
ic iron stone, or a magnetic iron rod, floating, by the aid of a piece of
wood, in water, or suspended in the air by a thread, in such a position
as to admit of free motion.

TERRESTRIAL MAGNE.ISM. 181

the horizontal deviation from the terrestrial meridian of the
spot. Their combined action may therefore be graphically
represented by three systems of lines, the isodynamic, isoclinic,
and isogonic (or those of equal force, equal inclination, and
equal declination). The distances apart, and the relative po-
sitions of these moving, oscillating, and advancing curves, do
not always remain the same. The total deviation (variation
or declination of the magnetic needle) has not at aU changed,
or, at any rate, not in any appreciable degree, during a whole
century, at any particular point on the Earth's surface,* as,
for instance, the western part of the Antilles, or Spitzbergen.
In like manner, we observe that the isogonic curves, when they
pass in their secular motion from the surface of the sea to a
continent or an island of considerable extent, continue for a long
time in the same position, and become inflected as they advance.
These gradual changes in the forms assumed by the hnes
in their translatory motions, and which so unequally modify
the amount of eastern and western declination, in the course
of time render it difficult to trace the transitions and analogies
of forms in the graphic representations belonging to different
centuries. Each branch of a curve has its history, but this
history does not reach further back among the nations of the
West than the memorable epoch of the 13th of September,
1492, when the re-discoverer of the New World found a line
of no variation 3° west of the meridian of the island of Flores,
one of the Azores. t The whole of Europe, excepting a small

* A very slow secular progression, or a local invariability of the mag-
netic declination, prevents the confusion which might arise from terres-
trial influences in the boundaries of land, when, with an utter disregard
for the correction of declination, estates are, after long intervals, rieas-
ured by the mere application of the compass. " The whole mass of
West Indian property," says Sir John Herschel, " has been saved from
the bottomless pit of endless litigation by the invariability of the mag-
netic declination in Jamaica and the surrounding Archipelago during
the whole of the last century, all surveys of property there having
been conducted solely by the compass." See Robertson, in the Philo-
sophical Transactions for 1806, Part ii., p. 348, On the Permanency of
the Compass in Jamaica since 1660. In the mother country (England)
the magnetic declination has varied by fully 14° during that period.

t I have elsewhere shown that, from the documents which have
come down to us regarding the voyages of Columbus, we can, with
much certainty, fix upon three places in the Atlantic line of no declina-
tion for the l'3th of September, 1492, the 21st of May, 1496, and the
16th of August, 1498. The Atlantic line of no declination at that pe-
riod ran from northeast to southwest. It then touched the South
American continent a little east of Cape Codera, while it is now ob"
served to reach that continent on the northern coast of the Brtizik
(Humboldt, Examen Critique dr VHisi. de la Geogr., t. iii., p. 44 A!h \

l82 COSMOS.

part of Russia, has now a western declination, while at the
close of the seventeenth century the needle first pointed due
north, in London in 1657, and in Paris in 1669, there being
thus a difference of twelve years, notwithstanding the small
distance between these two places. In Eastern Hussia, to
the east of the mouth of the Volga, of Saratow, Nischni-Now-
gorod, and Archangel, the easterly declination of Asia is ad-
vancing toward us. Two admirable observers, Hansteen and
Adolphus Erman, have made us acquainted with the remark-
able double curvature of the lines of declination in the vast
region of Northern Asia ; these being concave toward the
pole between Obdorsk, on the Oby, and Turuchansk, and con-
vex between the Lake of Baikal and the Gulf of Ochotsk. In
this portion of the earth, in northern Asia, between the mount-
ains of Werchojansk, Jakutsk, and the northern Korea, the
isogonic lines form a remarkable closed system. This oval
configuration* recurs regularly, and over a great extent of the
South Sea, almost as far as the meridian of Pitcairn and the
group of the Marquesas Islands, between 20° north and 45°

From Gilbert's Physiologia Nova de Magnete, we see plainly (and the
fact is very remarkable) that in 1600 the declination was still null in
the region of the Azores, just as it had been in the time of Columbus
(lib. 4, cap. 1). I believe that in my Examen Critique (t. iii., p. 54)
I have proved from documents that the celebrated line of demarkation
by which Pope Alexander VI. divided the Western hemisphere between
Portugal and Spain was not drawn through the most western point of
the Azores, because Columbus wished to convert a physical into a po-
litical division. He attached great importance to the zone (raya) " in
which the compass shows no variation, where air and ocean, the latter
covered with pastures of sea-weed, exhibit a peculiar constitution,
where cooling winds begin to blow, and where [as erroneous observa-
tions of the polar star led him to imagine] the form (sphericity) of the
Earth is no longer the same."

* To determine whether the two oval systems of isogonic lines, so
singularly included each within itself, will continue to advance for cen-
turies in the same inclosed form, or will unfold and expand themselves,
is a question of the highest interest in the problem of the physical
causes of terrestrial magnetism. In the Eastern Asiatic nodes the dec-
lination increases from without inward, while in the node or oval sys-
tem of the South Sea the opposite holds good ; in fact, at the present
time, in the whole South Sea to the east of the meridian of Kamt-
Bchatka, there is no line where the declination is null, or, indeed, in
which it is less than 2° (Erman, in Pogg., Annul., bd. xxxi., $ 129).
Yet Cornelius Schouten, on Easter Sunday, 1616, appears to have found
the declination null somewhere to the southeast of Nukahiva, in 15°
south lat. and 132° west long., and consequently in the middle of the
present closed isogonal system. (Hansteen, Magnet, der Erde, 1819, $
28.) It must not'be forgotten, in the midst of all these considerations.
that we can only follow the direction of the magnetic lines in their
progress as they are projected upon the surface of the Earth.

MAGNETISM. 183

south lat. One wouli. almost be inclined to regard this sin-
gular configuration of closed, almost concentric, lines of decli-
nation as the effect of a local character of that portion of the
globe ; but if, in the course of centuries, these apparently iso-
lated systems should also advance, we must suppose, as in the
case of all great natural forces, that the phenomenon arises
from some general cause.

The horary variations of the declination, which, although
dependent upon true time, are apparently governed by the
Sun, as long as it remains above the horizon, diminish in an-
gular value with the magnetic latitude of place. Near the
equator, for instance, in the island of Rawak, they scarcely
amount to three or four minutes, while they are from thirteen
to fourteen minutes in the middle of Europe. As in the whole
northern hemisphere the north point of the needle moves from
east to west on an average from 8^ in the morning until 1^ at
mid-day, while in the southern hemisphere the same nortli
point moves from west to east,* attention has recently bee;i
drawn, with much justice, to the fact that there must be a
region of the Earth between the terrestrial and the magnetic
equator where no horary deviations in the declination are to be
observed. This fourth curve, which might be called the curve
of no motion, or, rather, the line of no variation of horary
declinatian, has not yet been discovered.

The term 77iagnetic poles has been applied to those points
of the Earth's surface where the horizontal power disappears,
and more importance has been attached to these points than
properly appertains to them ;t and in like manner, the curve,
where the inclination of the needle is null, has been termed
the magnetic equator. The position of this line and its secular
change of configuration have been made an object of careful
investigation in modern times. According to the admirable
work of Duperrey,$ who crossed the magnetic equator six times
between 1822 and 1825, the nodes of the two equators, that
is to say,, the two points at which the line without inclination
intersects the terrestrial equator, and consequently passes from
one hemisphere into the other, are so unequally placed, that
in 1825 the node near the island of St. Thomas, on the west-

* Arago, in the 'Annvaire, 1836, p. 284, and 1840, p. 330-338.

t Gauss, Allg. Theorie des Erdmagnet., $ 31.

X Duperrey, De la Configuration de VEquatenr Magnitique, in the
Annales de Chimie, t. xlv., p. 371 and 379. (See, also, Morlet, in the
Mimoires pr6sent4s par divers Savans a V Acad. Roy. des Sciences, t. iii*,
? 1^2.)

184 cosMus.

ern coast of Africa, was 188^° distant from the node in the
J:50uth Sea, close to the little islands of Gilbert, nearly in the
meridian of the Viti group. In the beginning of the present
century, at an elevation of 11,936 feet above the level of the
sea, I made an astronomical determination of the point (7° 1'
south lat., 48° 40' west long, from Paris), where, in the in-
terior of the New Continent, the chain of the Andes is inter-
sected by the magnetic equator between Quito and Lima. To
the west of this p^int, the magnetic equator continues to trav-
erse the South S3a in the southern hemisphere, at the same
time slowly drawing near the terrestrial equator. It first pass-
es into the northern hemisphere a little before it approaches
the Indian Archipelago, just touches the southern points of
Asia, and enters the African continent to the west of Socotora,
almost in the Straits of Bab-el-Mandeb, where it is most dis-
tant from the terrestrial equator. After intersecting the un-
known regions of the interior of Africa in a southwest direc-
tion, the magnetic equator re-enters the south tropical zone in
the Gulf of Guinea, and retreats so far from the terrestrial
equator that it touches the Brazilian coast near Os Ilheos,
north of Porto Seguro, in 15° south lat. From thence to the
elevated plateaux of the Cordilleras, between the silver mines
of Micuipampa and Caxamarca, the ancient seat of the Incas,
where I observed the inclination, the line traverses the whole
of South America, which in these latitudes is as much a mag-
netic terra uicognita as the interior of Africa.

The recent observations of Sabine* have shown that the
node near the island of St. Thomas has moved 4° from east to
.west between 1825 and 1837. It would be extremely im-
portant to know whether the opposite pole, near the Gilbert
Islands, in the South Sea, has approached the meridian of the
Carolinas in a westerly direction. These general remarks wil]
be sufficient to connect the different systems of isoclinic non-
parallel lines with the great phenomenon of equilibrium which
is manifested in the magnetic equator. It is no small advant-
age, in the exposition of the laws of terrestrial magnetism, that
the magnetic equ.ator (whose oscillatory change of form and
whose nodal motion exercise an influence on the inclination
of the needle in the remotest districts of the world, in conse-
quence of the altered magnetic latitudes)! shpuld traverse the

* See the remarkable chart of isoclinic lines in the Atlantic Ocean
for the years 1825 and 1837, in Sabine's Contributions to Terrestrial,
Magnetism, 1840, p. 134.

t HuTuboldt, Ueber die seculd'e Verdnderung der Magnetischen Inr

MAGNETISM. 185

ocean throughout its whole course, excepting ahout one fifth,
and consequently be made so much more accessible, owing to
the remarkable relations in space between the sea and land,
and to the means of which we are now possessed for determin-
ing with much exactness both the declination and the inclina-
tion at sea.

We have described the distribution of magnetism on the
surface of our planet according to the two forms of declination
and inclination ; it now, therefore, remains for us to speak of
the intensity of the force which is graphically expressed by
isodynamic curves (or lines of equal intensity). The investi-
gation and measurement of this force by the oscillations of a
vertical or horizontal needle have only excited a general and
lively interest in its telluric relations since the beginning of
the nineteenth century. The application of delicate optical
and chronometrical instruments has rendered the measure-
ment of this horizontal power susceptible of a degree of accu-
racy far surpassing that attained in any other magnetic de-
terminations. The isogenic hues are the more important in
their immediate application to navigation, while we find from
the most recent views that isodynamic lines, especially those
which indicate the horizontal force, are the most valuable ele-
ments in the theory of terrestrial magnetism.* One of the
earliest facts yielded by observation is, that the intensity of
the total force increases from the equator toward the pole.f

clination (On the secular Change in the Magnetic Inclination), in Fogg.
Annul., bd. xv., s. 322.

* Gauss, ResuUate der Beob. des Magn. Vereins, 1838, $ 21; Sabine,
Report on the Variations of the Magnetic Intensity, p. 63.

t The following is the history of the discovery of the law that the
intensity of the force increases (in general) with the magnetic latitude.
When I was anxious to attach myself, iu 1798, to the expedition of
Captain Baudin, who intended to circumnavigate the globe, I was re-
quested by Borda, who took a warm intei'est in the success of my proj-
ect, to examine the oscillations of a vertical needle in the magnetic me-
ridian in different latitudes in each hemisphere, in order to determine
whether the intensity of the force was the same, or whether it varied in
different places. During my travels in the tropical regions of America,
I paid much attention to this subject. I observed that the same needle,
which in the space of ten minutes made 245 oscillations in Paris, 246 in
the Havana, and 242 in Mexico, performed only 216 oscillations during
the same period at St. Carlos del Rio Negro (1° 53' north lat. and 80^
40 west long, from Paris), on the magnetic equator, i. e., the line in
which the inebriation =0 ; in Peru (7^ 1 south lat. and 80° 40' west
long, from I'ansj only 211 ; while at Lima (12° 2' south lat.) the num-
ber rose to 219. I found, in the years intervening between 1799 and
1803, that the whole force, if we assume it at 1*0000 on the magnetic
equator in the Peruvian Andes, between Micuipampa and Caxamarca,

386 COSMOS.

The knowledge which we possess of the quantity of this in'
crease, and of all the numerical relations of the law of in-

may be expressed at Paris by 1-3482, hi Mexico by 1-3155, in San Carlos
del Rio Negro by 1*0480, and in Lima by 1-0773. When I develoj)ed
this law of the variable intensity of terrestrial magnetic force, and sup-
ported it by the numerical value of observations instituted in 104 dif-
ferent places, in a Memoir read before the Paris Institute on the 26th
Frimaire, An. XIII. (of which the mathematical portion was contributed
by M. Biot), the facts were regarded as altogether new. It was only
after the reading of the paper, as Biot expressly states (Lametherie,
Journal de Physique, t. lix., p. 446, note 2), and as I have repeated in
the Relation Historique, t. i., p. 262, note 1, that M. de Rossel commu-
nicated to Biot his oscillation experiments made six years earlier (be-
tween 1791 and 1794) in Van Diemen's Land, in Java, and in Amboyna.
These experiments gave evidence of the same law of decreasing force
in the Indian Archipelago. It must, I think, be supposed, that this ex-
cellent man, when he wrote his work, was not aware of the regularity
of the augmentation and diminution of the intensity, as before the read-
ing of my paper he never mentioned this (certainly not unimportant)
physical law to any of our mutual friends. La Place, Delambre, Prony,
or Biot. It was not till 1808, four years after my return from America,
that the observations made by M. de Rossel were published in the Voy^
age de V Entrecasteanx, t. ii., p. 287, 291, 321, 480, and 644. Up to the
present day it is still usual, in all the tables of magnetic intensity which
have been published in Germany (Hansteen, Magnet, der Erde, 1819,
6. 71 ; Gauss, Beob. des Magnet. Vereins, 1838, s. 36-39 ; Erman, Phij-
tikal. Beob., 1841, s. 529-579), in England (Sabine, Report on Magnet.
Intensity, 183S, p. 43-62; Contributions to Terrestrial Magnetis7n, 1843),
and in France (Becquerel, Traits de Electr. et de Magnet., t. vii., p.
354-367), to reduce the oscillations observed in any part of the Earth
to the standard of force which I found on the magnetic equator in
Northern Peru, so that, according to the unit thus arbitrarily assumed,
the intensity of the magnetic force at Paris is put down as 1-348. The
observations made by Lamanon in the unfortunate expedition of La
Perouse, during the stay at Teneriffe (1785), and on the voyage to
Macao (1787), are still older than those of Admiral Rossel. They were
Bent to the Academy of Sciences, and it is known that they were in the
possession of Condorcet in the July of 1787 (Becquerel, t. vii., p. 320) ;
but, notwithstanding the most careful search, they are not now to be
found. From a copy of a very important letter of Lamanon, now in tho
possession of Captain Duperrey, which was addressed to the then per-
petual secretary of the Academy of Sciences, but was omitted in the
narrative of the Voyage de La Perouse, it is stated " that the attractive
force of the magnet is less in the tropics than when we approach the
poles, and that the magnetic intensity deduced from the number of os-
cillations of the needle of the inclination-compass varies and increases
"^ith the latitude." If the Academicians, while they continued to ex-
pect the return of the unfortunate La Perouse, had felt themselves justi-
fied, in the course of 1787, in publishing a truth which had been inde-
pendently discovered by no less than three different travelers, the theory
of terrestrial magnetism would have been extended by the knowledge
of a new class of observations, dating eighteen years earlier than they
now do. This simple statement of facts may probably justify the ol>
nervations contained iu tl e third voluiue of my Relation, Historique (p

MAGNETISM. 18T

tensity afTecting the whole Earth, is especially due, since 18 19^
to the unwearied activity of Edward Sabine, who, after hav-
ing observed the oscillations of the same needles at the Ameri-
can north pole, in Greenland, at Spitzbergen, and on the coasts
of Guinea and Brazil, has continued to collect and arrange
all the facts capable of explaimng the direction of the isody-
namic lines. I have myself given the first sketch of an isody-
namic system in zones for a small part of South America.
These lines are not parallel to lines of equal inclination (iso-
clinic lines), and the intensity of the force is not at its minimum
at the magnetic equator, as has been supposed, nor is it even
equal at all parts of it. If we compare Erman's observations
in the southern part of the Atlantic Ocean, where a faint zone
(0-706) extends from Angola over the island of St. Helena to
the Brazilian coast, with the most recent investigations of the
celebrated navigator James Clark Ross, we shall find that
on the surface of our planet the force increases almost in the
relation of 1 : 3 toward the magnetic south pole, where Vic-
toria Land extends from Cape Crozier toward the volcano
Erebus, which has been raised to an elevation of 12,600 feet
above the ice.* If the intensity near the magnetic south pole

615) : " The observations on the variation of terrestrial magnetism, to
which I have devoted myself for thirty-two years, by means of instru-
ments which admit of comparison with one another, in America, Europe,
and Asia, embrace an area extending over 188 degrees of longitude,
from the frontier of Chinese Dzoungarie to the west of the South Sea
bathing the coasts of Mexico and Peru, and reaching from 60° north
lat. to 12° south lat. I regard the discovery of the law of the decre-
ment of magnetic force from the pole to the equator as the most im-
portant result of my American voyage." Although not absolutely cer-
tain, it is very probable that Condorcet read Lamanon's letter of July,
1787, at a meeting of the Paris Academy of Sciences; and such a sim-
ple reading I regard as a sufficient act of publication. (Annvaire du
Bureau des Longitudes, 1842, p. 463.) The first recognition of the law
belongs, therefore, beyond all question, to the companion of La Perouse;
but, long disregarded or forgotten, the knowledge of the law that the
intensity of the magnetic force of the Earth varied with the latitude,
did not, I conceive, acquire an existence in science until the publica-
tion of my observations from 1798 to 1804. The object and the length
of this note will not be indifferent to those who are familiar with the
recent history of magnetism, and the doubts that have been started in
connection with it, and who, from their own experience, ai'e aware
that we are apt to attach some value to that which has cost us the un-
interrupted labor of five years, under the pressure of a tropical climate,
and of perilous mountain expeditions.

* From th^ observations hitherto collected, it appears that the max-
imum of intensity for the whole surface of tlie Earth is 2-052, and the
minimum 0.706. Both phenomena occur in the southern hemisphere;
tiie former in 73° 47' S. lat., and 169° 30' E. long, from Paris, near

ISS COSMOS.

be expressed by 2- 052 (the unit still employed being the in*
tensity which I discovered on the magnetic equator in North-
ern Peru), Sabine found it was only 1"624 at the magnetic
north pole near Melville Island (74° 2T north lat.), while it
is 1*803 at New York, in the United States, which has al-
most the same latitude as Naples.

The brilliant discoveries of CErsted, Arago, and Faraday
have established a more intimate connection between the elec-
tric tension of the atmosphere and the magnetic tension of our
terrestrial globe. While OErsted has discovered that elec-
tricity excites magnetism in the neighborhood of the conduct-
ing body, Faraday's experiments have elicited electric currents
from the liberated magnetism. Magnetism is one of the mani-
fold forms under which electricity reveals itself. The ancient
vague presentiment of the identity of electric and magnetic
attraction has been verified in our own times. " When elec-
trura (amber)," says Pliny, in the spirit of the Ionic natural
philosophy of Thales,^ " is animated by friction and heat, it
will attract bark and dry leaves precisely as the loadstone at-
tracts iron." The same words may be found in the literature
ef an Asiatic nation, and occur in a eulogium on the load-
stone by the Chinese physicist Kuopho.t I observed with as-

Mount Crozier, west-northwest of the south magnetic pole, at a place
where Captain James Ross found the inclination of the needle to be 87°
11' (Sabine, Contributions to Terrestrial Magnetism, 1843, No. 5, p.
231) ; the latter, observed by Ermau, at 19° 59' S. lat., and 37° 24' W.
long, from Paris, 320 miles eastward from the Brazilian coast of Espiiitu
Santo (Erman, Phys. Beob., 1841, s. 570), at a point where the inclina-
tion is only 7° 55'. The actual ratio of the two intensities is therefore
as 1 to 2-906. It was long believed that the greatest intensity of the
magnetic force w^as only two and a half times as great as the weakest
exhibited on the Earth's surface. (Sabine, Report on Magnetic In-
tensity, p. 82.)

* Of amber (succinum, glessum) Pliny obsei'ves (xxxvii., 3), " Gen-
era ejus plura. Attritu digitorum accepta caloris anima trahunt in se
paleas ac folia arida quae levia sunt, ac ut magnes lapis ferri ramenta
quoque." (Plato, ire Timceo, p. 80. Martin, Etude sur le Timie, t. ii.,
p. 343-346. Strabo, xv., p. 703, Casaub. ; Clemens Alex., Strom., ii.,
p. 370, where, singularly enough, a difference is made JDetween to
aovxLov and to ^TiSKTpov.) When Thales, in Aristot., de Anima, 1, 2,
and Hippias, in Diog. Laert., i., 24, describe the magnet and amber as
possessing a soul, they refer only to a moving principle.

t * The magnet attracts iron as amber does the smallest grain of mus-
tard seed. It is like a breath of wind which mysteriously penetrate!
through both, and communicates itself with the rapidity of an arrow."
These are the words of Kuopho, a Chinese panegyrist on the magnet,
w^ho wrote in the beginning of the fourth century. (Klaproth,Le^^j*« A
M. A. de Humboldt, s7i V Invention de la Bous»ple, 1834, p. 125.^

MAGNETISM. , 189

tonishment, on the woody banks of the Orinoco, in the sports
of the natives, that the excitement of electricity by friction
was known to these savage races, who occupy the very lowest
place in the scale of humanity. Children may be seen to rub
the dry, flat, and shining seeds or husks of a trailing plant
(probably a Negretia) until they are able to attract threads
of cotton and pieces of bamboo cane. That which thus de-
lights the naked copper-colored Indian is calculated to awaken
in our minds a deep and earnest impression. What a chasm
divides the electric pastime of these savages from the discov-
ery of a metallic conductor discharging its electric shocks, or a
pild^jomposed of many chemically-decomposing substances, or
a light-engendering magnetic apparatus I In such a chasm
lie buried thousands of years that compose the history of the
intellectual development of mankind I

The incessant change or oscillatory motion which we dis-
cover in all magnetic phenomena, whether in those of the in-
clination, declination, and intensity of these forces, according
to the hours of the day and the night, and the seasons and the
course of the whole year, leads us to conjecture the existence
of very various and partial systems of electric currents on the
surface of the Earth. Are these currents, as in Seebeck's ex-
periments, thermo-magnetic, and excited directly from unequal
distribution of heat ? or should we not rather regard them as
induced by the position of the Sun and by solar heat ?* Have
the rotation of the planets, and the different degrees of velocity
which the individual zones acquire, according to their respect-
ive distances from the equator, any influence on the distribu
tion of magnetism ? Must we seek the seat of these currents,
that is to say, of the disturbed electricity, in the atmosphere,
in the regions of planetary space, or in the polarity of the Sun
and Moon ? Galileo, in his celebrated Dialogo, was inclined
to ascribe the parallel direction of the axis of the Earth to a
magnetic point of attraction seated in universal space.

If we represent to ourselves the interior of the Earth as
fused and undergoing an enormous pressure, and at a degree
of temperature the amount of which we are unable to assign,

* " The phenomena of periodical variations depend manifestly on the
action of solar heat, operating probabiy through the medium of thermo-
electric currents induced on the Earth's surface. Beyond this rude
guess, however, nothing is as yet known of their physical cause. It ia
even still a matter of speculation whether the solar influence be a prin-
cipal or only a subordinate cause in the phenomena of terrestrial mag-
netism." {Observations to be made in the Antarctic Expedition, 1840.
p, 3f)

190 COSMOS.

we must renounce all idea of a magnetic nucleus of the Earth,
All magnetism is certainly not lost until we arrive at a white
heat,* and it is manifested when iron is at a dark red heat ,
however different, therefore, the modifications may be which
are excited in substances in their molecular state, and in the
coercive force depending upon that condition in experiments
of this nature, there will still remain a considerable thickness
of the terrestrial stratum, which might be assumed to be the
seat of magnetic currents. The old explanation of the horary
variations of declination by the progressive warming of the
Earth in the apparent revolution of the Sun from east to west
must be limited to the uppermost surface, since thermometers
sunk into the Earth, which are now being accurately observed
at so many different places, show how slowly the solar heat
penetrates even to the inconsiderable depth of a few feet.
xMoreover, the thermic condition of the surface of water, by
which two thirds of oftr planet is covered, is not favorable to
such modes of explanation, when we have reference to ap im-
mediate action and not to an effect of induction in the aerial
and aqueous investment of our terrestrial globe.

In the present condition of our knowledge, it is impossible
to afford a satisfactory reply to all questions regarding the ulti-
mate physical causes of these phenomena. It is only with ref-
erence to that which presents itself in the triple manifestations
of the terrestrial force, as a measurable relation of space and
time, and as a stable element in the midst of change, that
science has recently made such brilliant advances by the aid
of the determination of mean numerical values. From To-
ronto in Upper Canada to the Cape of Good Hope and Van Die-
men's Land, from Paris to Pekin, the Earth has been covered,
since 1828, with magnetic observatories,! in which every regu-

* Barlow, in the Philos. Trans, for 1822, Pt. i., p. 117 ; Sir David
Brewster, Treatise on Magnetism, p. 129. Long before the times of
Gilbert and Hooke, it was taught in the Chinese work Oio-thsa-tsou
that heat diminished the directive force of the magnetic needle. (Kla-
proth, Lettre a M. A. de Humboldt, aur V Invention de la Boussole, p. 9^.)

t As the first demand for the establishment of these observatories ^_a
net-work of stations, provided with similar instruments) proceeded
from me, I did not dare to cherish the hop:) that I should live long
enough to see the time when both hemispheres should be uniformly
covered with magnetic houses under the associated activity of abl*
physicists and astronomers. This has, however, been accomplished,
and chiefly through the hberal and continued support of the Russian and
British governments.

In the years 1806 and 1807, 1 and my friend and fellow-laborer, Herr
Oltmauns, while at Berlin, observed the movements of the needle, espe*

MAGNETISM. 191

lar or irfegular manifestation of the terrestrial force is detected
by uninterrupted and simultaneous observations. A variation

cially at the times of the solstices and equinoxes, from hour to hour,
and often from half hour to half hour, for five or six days and nights
uninterruptedly. I had persuaded myself that continuous and uninter-
rupted observations of several days and nights (obsers'atio perpetua)
were preferable to the single observations of many months. The ap-
paratus, a Prony's magnetic telescope, suspended in a glass case by a
thread devoid of torsion, allov^ed angles of seven or eight seconds to be
read off on a finely-divided scale, placed at a proper distance, and
lighted at night by lamps. Magnetic perturbations (storms), which oc-
casionally recurred at the same hour on several successive nights, led
me even then to desire extremely that similar apparatus should be used
to the east and west of Berlin, in order to distinguish general terres-
trial phenomena from those which are mere Iqcal disturbances, depend-
ing on the inequality of heat in different parts of the Earth, or on the
cloudiness of the atmosphere. My departure to Paris, and the long
period of political disturbance that involved the whole of the west of
Europe, prevented my wish from being then accomplished. CErsted's
great discovery (1820) of the intimate connection between electricity
and magnetism again excited a general interest (which had long flag-
ged) in the periodical variations of the electro-magnetic tension of the
Earth. Arago, who many years previously had commenced in the Ob-
servatory at Paris, with a new and excellent declination instrument by
Gambey, the longest uninterrupted series of horary observations which
we possess in Europe, showed, by a comparison with simultaneous ob-
servations of perturbation made at Kasan, what advantages might be
obtained from corresponding measurements of declination. When I
returned to Berlin, after an eighteen years' residence in France, I had
a small magnetic house erected in the autumn of 1828, not only with
the view of carrying on the work commenced in 1806, but more with
the object that simultaneous observations at hours previously determ-
ined might be made at Berlin, Paris, and Freiburg, at a depth of 35
fathoms below the surface. The simultaneous occurrence of the per-
turbations, and the parallelism of the movements for October and De-
cember, 1829, were then graphically represented. (Pogg., Annalen,
bd. xix., 8. 357, taf. i.-iii.) An expedition into Northern Asia, under-
taken in 1829, by command of the Emperor of Russia, soon gave me an
opportunity of working out my plan on a larger scale. This plan was
laid before a select committee of one of the Imperial Academies of
Science, and, under the protection of the Director of the Mining Depart-
ment, Count von Cancrin, and the excellent superintendence of Pro-
fessor KupfFer, magnetic stations were appointed over the whole of
Northern Asia, from Nicolajefi', in the line through Catharinenburg, Bar-
naul, and Nertschinsk, to Pekin.

The year 1832 {Gdttinger gelehrte Anzeigen, st. 206) is distinguished
as the great epoch in which the profound author of a general theory of
terrestrial magnetism, Friedrich Gauss, erected apparatus, constructed
on a new principle, in the Gottingen Observatory. The magnetic ob-
servatory was finished in 1834, and in the same year Gauss distributed
new instruments, with instructions for their use, in which the celebrated
physicist, Wilhelm Weber, took extreme interest, over a Ijfrge portion
of Germany and Sweden, and the whole of Italy. {ResuUate der Beob.
des Magnetischen Vereins im Jahr 1338, s. 135, and ^oggend., Annalen,

192 cos»K)a

^^T^loo^'i of the magnetic intensity is measured, and, at cer-
tain epochs, observations are made at intervals of 2i minutes,
and continued for tw^enty-four hours consecutively. A great
English astronomer and physicist has calculated* that the
mass of observations which are in progress will accumulate in
the course of three years to 1,958,000. Never before has so
noble and cheerful a spirit presided over the inquiry into the
quantitative relations of the laws of the phenomena of nature.
We are, therefore, justified in hoping that these laws, when
compared with those which govern the atmosphere and the
remoter regions of space, may, by degrees, lead us to a more
intimate acquaintance with the genetic conditions of magnetic
phenomena. As yet we can only boast of having opened a
greater number of paths which may possibly lead to an ex-
planation of this subject. In the physical science of terres-

bd. xxxiii., s. 426.) In the magnetic association that was now formed
with Gottingen for its centei', simultaneous observations have been un-
dertaken four times a year since 1836, and continued uninterruptedly
for twenty-four hours. The periods, however, do' not coincide with
those of the equinoxes and solstices, which I had proposed and followed
out in 1830. Up to this period. Great Britain, in possession of the most
extensive commerce and the largest navy in the world, had taken no
part in the movement which since 1828 had begun to yield important
results for the more fixed ground-work of terrestrial magnetism. I had
the good fortune, by a public appeal from Berlin, which I sent in April,
1836, to the Duke of Sussex, at that time President of the Royal So-
ciety (Lettre de M. de Humboldt k S.A.R. le Due de Sussex, sur les
moyens propres k perfectionner la connaissance dumagnetisme terrestre
par I'etablissement des stations magn6tiques et d'obsers^ations corre-
spondantes), to excite a fiiendly interest in the undertaking which it
had so long been the chief object of my wish to carry out. In my let-
ter to the Duke of Sussex 1 urged the establishment of permanent sta-
tions in Canada, St. Helena, the Cape of Good Hope, the Isle of France,
Ceylon, and New Holland, which five years previously I had advanced
as good positions. The Royal Society appointed a joint physical and
meteorological committee, which not only proposed to the government
the establishment of fixed magnetic observatories in both hemispheres,
but also the equipment of a naval expedition for magnetic observations
in the Antarctic Seas. It is needless to proclaim the obligations of
science in this matter to the great activity of Sir John Herschel, Sabine,
Airy, and Lloyd, as well as the powerful support that was afforded by
the British Association for the Advancement of Science at their meet-
ing held at Newcastle in 1838. In June, 1839, the Antarctic magnetic
expedition, under the command of Captain James Clark Ross, was fully
arranged ; and now, since its successful return, we reap the double
fruits of highly important geographical discoveries around the south
pole, and a series of simultaneous observations at eight or ten magnetic
stations.

* See the article on Terrestrial Magnetism, in the Quarterly Remew
1840, vol. Ixvi p 271-312.

AURORA BOREALIS. 193

trial magnetism, which must not be confounded with the
purely mathematical branch of the study, those persons only
will obtain perfect satisfaction who, as in the science of the
meteorological processes of the atmosphere, conveniently turn
aside the practical bearing of all phenomena that can not be
explained according to their own views.

Terrestrial magnetism, and the electro-dynamic forces com-
puted by the intellectual Ampere,* stand in simultaneous and
intimate connection with the terrestrial or polar light, as well
as with the internal and external heat of our planet, whose
nagnetic poles may be considered as the poles of cold.t The
)old conjecture hazarded one hundred and twenty-eight years
since by Halley,$ that the Aurora Borealis was a magnetic
phenomenon, has acquired empirical certainty from Faraday's
brilliant discovery of the evolution of light by magnetic forces.
The northern light is preceded by premonitory signs. Thus,
in the morning before the occurrence of the phenomenon, the
irregular horary course of the magnetic needle generally indi-
cates a disturbance of the equilibrium in the distribution of

* Instead of ascribing the internal heat of the Earth to the transition
of matter from a vapor-Uke fluid to a solid condition, which accom-
panies the formation of the planets, Ampere has propounded the idea,
which I regard as highly improbable, that the Earth's temperature may
be the consequence of the continuous chemical action of a nucleus of
the metals of the earths and alkalies on the oxydizing external crust.
*' It can not be doubted," he observes in his masterly Thdorie des Ph6no-
menes Electro-dynamiques, 1826, p. 199, " that electro-magnetic cur-
rents exist in the interior of the globe, and that the&e currents are the
cause of its temperature. They arise from the action of a central me-
tallic nucleus, composed of the metals discovered by Sir Humphrey
Davy, acting on the suiTounding oxydized layer."

+ The remarkable connection between the curvature of the magnetic
lines and that of my isothermal lines was first detected by Sir David
Brewster. See the Transaction* of the Royal Society of Edinburgh, vol.
ix., 1821, p. 318, and Treatise on Magnetism^ 1837, p. 42, 44, 47, and
208. This distinguished physicist admits two cold poles (poles of maxi-
mum cold) in the northern hemisphere, an American one near Capo
Walker (73° lat., 100° W. long.), and an Asiatic one (73° lat., 80° E.
long.); whence arise, according to him, two hot and two cold merid-
ians, i. c, meridians of greatest heat and cold. Even in the sixteenth
century, Acosta {Historia Natural de las Indias, 1589, lib. i., cap. 17),
grounding his opinion on the observations of a very experienced Portu-
guese pilot, taught that there were four lines without declination. It
would seem from the controversy of Henry Bond (the author of The
Longitude Found, 1676) with Beckborrow, that this view in some meas-
ure influenced Halley in his theory of four magnetic poles. See my
Examen Critique de VHisl. de la Giographie, t. iii., p. 60.

X Halley, in the Philosovhical Transactions, vol. xxix. (for 1714-1716 ),
No. 341.

Vol. I— J

194 COSMOS.

terrestrial magnetism * When this disturbance attains a great
degree of intensity, the equilibrium of the distribution is re-
stored by a discharge attended by a development of light
' The Aurorat itself is, therefore, not to be regarded as an ex
ternally manifested cause of this disturbance, but rather as a
result of telluric activity, manifested on the one side by the
appearance of the light, and on the other by the vibrations of
the magnetic needle." The splendid appearance of colored
polar light is the act of discharge, the termination of a mag
netic storm, as in an electrical storm a development of light —
the flash of lightning — indicates the restoration of the disturb-
ed equilibrium in the distribution of the electricity. An elec-
tric storm is generally confined to a small space, beyond the
limits of w^hich the condition of the atmospheric electricity
remains unchanged. A magnetic storm, on the other hand,

* [The Aurora Borealis of October 24th, 1847, which was one of the
most brilliant ever known in this country, was preceded by gi-eat mag-
netic disturbance. On the 22d of October the maximum of the west
declination was 23° 10' ; on the 23d the position of the magnet waa
continually changing, and the extreme west declinations were between
22° 44' and 23° 37' ; on the night between the 23d and 24th of October,
the changes of position were very large and very frequent, the magnet
at times moving across the field so rapidly that a difiSculty was experi-
enced in following it. During the day of the 24th of October there was
a constant change of position, but after midnight, when the Aurora be-
gan perceptibly to decline in brightness, the disturbance entirely ceased.
The changes of position of the horizontal-force magnet were as large and
as frequent as those of the declination magnet, but the vertical-force
magnet was at no time so much affected as the other two instruments.
See On the Aurora Borealis, as it was seen on Sunday evening, Octohei
24iA, 1847, at Blackheath, by James Glaisher, Esq., of the Royal Observa
tory, Greenwich, in the London, Edinburgh, and Dublin Philos. Mag.
and Journal of Science for Nov., 1847. See further, An Account of iht
Aurora Borealis of October the 2Ath, 1847, by John H. Morgan, Esq.
We must not omit to mention that magnetic disturbance is now regis
tered by a photographic process : the self-registering photographic ap-
paratus used for this purpose in the Observatory at Greenwich was de-
signed by Mr. Brooke, and another ingenious instrument of this kind
has been invented by Mr. F. Ronalds, of the Richmond Observatory.]—

#I)ove, in Poggend., Annalen, bd. xx., s. 341 ; bd. xix., s. 388.
" The declination needle acts in very nearly the same way as an atmos-
pheric electrometer, whose divergence in like manner shows the in*
creased tension of the electricity before this has become so great as to
yield a spark." See, also, the excellent observations of Professor Kamtz,
in his Lehrbuch der Meteorologie, bd. iii., s. 511-519, and Sir David
Brewster, in his Treatise on Magnetism, p. 280. Regarding the mag-
netic properties of the galvanic flame, or luminous arch from a Ban-
sen's carboi\ and zinc battery, see Casselmann's Beobachtungen (Mar-
burg, 1844), s. 56-62.

AURORA B0REALI3. 195

shows its influence on the course of the needle over large por-
tions of continents, and, as Arago first discovered, far from
the spot where the evolution of light was visible. It is not
improbable that, as heavily-charged threatening clouds, owing
to frequent transitions of the atmospheric electricity to an op
posite condition, are not always discharged, accompanied b)
lightning, so likewise magnetic storms may occasion far-ex
tending disturbances in the horary course of the needle, with
out there being any positive necessity that the equilibrium of
the distribution should be restored by explosion, or by the
passage of luminous efTusions from one of the poles to the
equator, or from pole to pole.

In collecting all the individual features of the phenomenon
in one general picture, we must not omit to describe the origin
and course of a perfectly developed Aurora Borealis. Low
down in the distant horizon, about the part of the heavens
which is intersected by the magnetic meridian, the sky which
was previously clear is at once overcast. A dense wall or
bank of cloud seems to rise gradually higher and higher, until
it attains an elevation of 8 or 10 degrees. The color of the
dark segment passes into brown or violet ; and stars are visi-
ble through the cloudy stratum, as when a dense smoke dark-
ens the sky. A broad, brightly-luminous arch, first white,
then yellow, encircles the dark segment ; but as the brilUant
arch appears subsequently to the smoky gray segment, we can
not agree with Argelander in ascribing the latter to the effect
of mere contrast with the bright luminous margin.* The
highest point of the arch of light is, according to accurate ob-
servations made on this subject,! not generally in the magnet-
ic meridian itself, but from 5° to 18*^ toward the direction of
the magnetic declination of the place.J In northern latitudes,

* Argelander, in the important observations on the northern light
embodied in the Vortrdgen gehalten in der physikalisch-okonomischen
Gessellschaft zu Konigsberg, bd. i., 1834, s. 257-264.

t For an account of the results of the observations of Lottin, Bravais,
and Siljerstrom, who spent a winter at Bosekop, on the coast of Lap
land (,70° N. lat.), and in 210 nights saw the northern lights 160 times,
see the Comftes Rendus de V Acad, des Sciences, t. x., p. 289, and Mar-
lins's Met^orologie, 1843, p. 453. See, also, Argelander, in the Vortra-
gen geh. in der Konigsberg Gessellschaft, bd. i., s. 259.

X [Professor Challis, of Cambridge, states that in the Aurora of Oc-
tober 24th, 1847, the streamers all converged toward a single point of
the heavens, situated in or very near a vertical circle passing through
the magnetic pole. Around this point a corona was formed, the rays
of which diverged in all directions from the center, leaving a space free
from light: its azimuth was 18° 41' from south to east, and its altitude
69° 54'. See Professor Challis, in the Aihenteum, Oct. 31, 1847.'}— Tr

196 COSMOS.

in the immediate vicinity of the magnetic pole, the smoke-like
conical segment appears less dark, and sometimes is not even
seen. Where the horizontal force is the weakest, the middle
of the luminous arch deviates the most from the magnetic
meridian.

The luminous arch remains sometimes for hours together
flashing and kindling in ever-varying undulations, before rays
and streamers emanate from it, and shoot up to the zenith.
The more intense the discharges of the northern light, the
more bright is the play of colors, through all the varying gra-
dations from violet and bluish white to green and crimson.
Even in ordinary electricity excited by friction, the sparks are
only colored in cases where the explosion is very violent after
great tension. The magnetic columns of flame rise either
singly from the luminous arch, blended with black rays simi-
lar to thick smoke, or simultaneously in many opposite points
of the horizon, uniting together to form a flickering sea of
flame, whose brilliant beauty admits of no adequate descrip-
tion, as the luminous waves are every moment assuming new
and varying forms. The intensity of this light is at times so
great, that Lowenorn (on the 29th of June, 1786) recognized
the coruscation of the polar light in bright sunshine. Motion
renders the phenomenon more visible. Round the point in
the vault of heaven which corresponds to the direction of the
inclination of the needle, the beams unite together to form the
so-called corona, the crown of the northern light, which en-
circles the summit of the heavenly canopy with a milder ra-
diance and unflickering emanations of light. It is only in
rare instances that a perfect crown or circle is formed, but on
its completion the phenomenon has invariably reached its
maximum, and the radiations become less frequent, shorter,
and more colorless. The crown and the luminous arches
break up, and the whole vault of heaven becomes covered
with irregularly-scattered, broad, faint, almost ashy-gray lu-
minous immovable patches, which in their turn disappear,
leaving nothing but a trace of the dark, smoke-like segment
on the horizon. There often remains nothing of the whole
spectacle but a white, delicate cloud with feathery edges, or
divided at equal distances into small roundish groups like cir-
fo-cumuli.

This connection of the polar light with the most dehcate
,arrous clouds deserves special attention, because it show^s that
Jie electro-magnetic evolution of light is a part of a meteoro-
ktf^'cal process. Terrestrial nvagnetism here manifests its in-

AURORA BOREALIS. 197

fluence on the atmosphere and on the condensation of aqueous
vapor. The fleecy clouds seen in Iceland by Thienemann,
and which he considered to be the northern light, have been
seen in recent times by Franklin and Richardson near the
American north pole, and by Admiral Wrangel on the Sibe-
rian coast of the Polar Sea. All remarked " that the Aurora
flashed forth in the most vivid beams when masses of cirrous
strata were hovering in the upper regions of the air, and when
these were so thin th^t their presence could only be recognized
by the formation of a halo round the moon." These clouds
sometimes range themselves, even by day, in a similar manner
to the beams of the Aurora, and then disturb the course of
the magnetic needte in the same manner as the latter. On
the morning after every distinct nocturnal Aurora, the same
superimposed strata of clouds have still been observed that
had previously been luminous.* The apparently converging
polar zones (streaks of clouds in the direction of the magnetic
meridian), which constantly occupied my attention during my
journeys on the elevated plateaux of Mexico and in Northern
Asia, belong probably to the same group of diurnal phenom-
enai

* John Franklin, Narrative of a Journey to the Shores of the Polai
Sea, in the Years 1819-1822, p. 552 and 597 ; Thienemann, in the
Edinburgh Philosophical Journal, vol. xx., p. 336 ; Farquharson, in vol.
vi., p. 392, of the same journal; Wrangel, Phys. Beob., s. 59. Pai'ry
even saw the great arch of the northern light continue throughout the
day. {Journal of a Second Voyage, ferformed in 1821-1823, p. 156.)
Something of the same nature was seen in England on the 9th of Sep-
tember, 1827. A luminous arch, 20° high, with columns proceeding
from it, was seen at noon in a part of the sky that had been clear after
rain. {Journal of the Royal Institution of Great Britain, 1828, Jan.,
p. 429.)

t On Biy return from my American travels, I described the delicate
cirro-cumulus cloud, which appears uniformly divided, as if by the
action of repulsive forces, under the name of polar bands {bandes po-
laires), because their perspective point of convergence is mostly at first
in the magnetic pole, so that the parallel rows of fleecy clouds follow
the magnetic meridian. One peculiarity of this mysterious phenomenon
is the oscillation, or occasionally the gradually progressive motion, of
the point of convergence. It is usually observed that the bands are
only fully developed in one region of the heavens, and they are seen
to move first from south to north, and then gradually from east to west.
I could not trace any connection between the advancing motion of the
bands and alterations of the currents of air in the higher regions of the
atmosphere. They occur when the air is extremely calm and the
heavens are quite serene, and are much more common under the
tropics than in the temperate and frigid zones. I have seen this phe-
nomenon on the Andes, almost under the equator, at an elevation of
15.920 feet, and in Northern Asia, in the plains of Krasnojarski, soutb

198 COSMOS.

Southern lights have often been seen in England by the in
telligent and indefatigable observer Dalton, and northern lights
have been observed in the southern hemisphere as far as 45^
latitude (as on the 14th of January, 1831). On occasions
that are by no means of rare occurrence, the equilibrium at
both poles has been simultaneously disturbed. I have discov-
ered with certainty that northern polar lights have been seen
within the tropics in Mexico and Peru. "VVe must distinguish
between the sphere of simultaneous visibility of the phenom-
enon and the zones of the Earth where it is seen almost night-
ly. Every observer no doubt sees a separate Aurora of his
own, as he sees a separate rainbow. A great portion of the
Eartk simultaneously engenders these phenomena of emana-
tions of light. Many nights may be instanced in which the
phenomenon has been simultaneously observed in England
and in Pennsylvania, in Rome and in Pekin. When it is
stated that Auroras diminish with the decrease of latitude,
the latitude must be understood to be magnetic, and as meas-
ured by its distance from the magnetic pole. In Iceland, in
Greenland, Newfoundland, on the shores of the Slave Lake,
and at Fort Enterprise in Northern Canada, these lights ap-
pear almost every night at certain seasons of the year, cele-
brating with their flashing beams, according to the mode of
expression common to the inhabitants of the Shetland Isles,
" a merry dance in heaven."* While the Aurora is a phe-
nomenon of rare occurrence in Italy, it is frequently seen in
the latitude of Philadelphia (39° 57'), owing to the southern
position of the American magnetic pole. In the districts
which are remarkable, in the New Continent and the Sibe-
rian coasts, for the frequent occurrence of this phenomenon,
there are special regions or zones of longitude in which the
polar light is particularly bright and brilliant, f The exist-

of Buchtarminsk, so similarly developed, that we must regard the in
(luences producing it as very w^idely distributed, and as depending on
general natural forces. See the important observations of Kamtz ( Var-
lesungen uber Metcorologie, 1840, s. 146), and the more recent ones of
Martins and Bravais {MHiorologie, 1843, p. 117). In south polar bands,
composed of very delicate clouds, observed by Arago at Paris on the
23d of June, 1844, dark rays shot upward from an arch running east
and west. We have already made mention of black rays, resembling
dark smoke, as occurring in brilliant nocturnal northern lights.

* The northern lights are called by the Shetland Islanders ''the
merry dancers." (Kendal, in the (Quarterly Journal of Science, new
series, vol. iv., p. 395.)

t See Muncke's excellent work in the new edition of Gehler's Physik
iVorterbiich, bd. vii., i., s. 1 13-268, and especially s. 158.

AURORA BOREALIS. 199

ence of local influences can not, therefore, be denied in th^e
cases. Wrangel saw the brilliancy diminish as he left the
shores of the Polar Sea, about Nischne-Kolymsk. The ob-
servations made in the North Polar expedition appear to prove
that in the immediate vicinity of the magnetic pole the dc"
velopment of light is not in the least degree more intense or
frequent than at some distance from it.

The knowledge which we at present possess of the altitude
of the polar light is based on measurements which, from their
nature, the constant oscillation of the phenomenon of light,
and the consequent uncertainty of the angle of parallax, are
not deserving of much confidence. The results obtained, set-
ting aside the older data, fluctuate between several miles and
an elevation of 3000 or 4000 feet ; and, in all probability,
the northern lights at different times occur at very different
elevations.* The most recent observers are disposed to place
the phenomenon in the region of clouds, and not on the con-
fines of the atmosphere ; and they even believe that the rays
of the Aurora may be affected by winds and currents of air, if
the phenomenon of light, by which alone the existence of an
electro-magnetic current is appreciable, be actually connected
with material groups of vesicles of vapor in motion, or, more
correctly speaking, if light penetrate them, passing from one
vesicle to another. Franklin saw near Great Bear Lake a
beaming northern light, the lower side of which he thought
illuminated a stratum of clouds, while, at a distance of only
eighteen geographical miles, Kendal, who was on watch'
throughout the whole night, and never lost sight of the sky,
perceived no phenomenon of light. The assertion, so fre-
vjuently maintained of late, that the rays of the Aurora have
been seen to shoot down to the ground between the spectator
and some neighboring hill, is open to the charge of optical
delusion, as in the cases of strokes of lightning or of the fall
of fire-balls.

Whether the magnetic storms, whose local character we
have illustrated by such remarkable examples, share noise as
well as light in common with electric storms, is a question

* Farquharson in the Edinburgh Philos. Journal, vol. xvi., p. 304 ;
Fhikis. Transact, for 1829, p. 113.

[The height of the bow of light of the Aurora seen at the Cambridge
Observatory, March 19, 1847, was determined by Professors ChaHis, of
Cambridge, and Ohevallier, of Durham, to be 177 miles above the sur
face of the Earth. See the notice of this meteor in An Account of the
Aurora Borealis of Oct. 24, 1847, by John H. Morgan, Esq., 1848.]—
Tr.

200 COSMOS.

that has become difficult to answer, since implicit confidence
is no longer yielded to the relations of Greenland whale-fish-
ers and Siberian fox-hunters. Northern lights appear to have
become less noisy since their occurrences have been more ac-
curately recorded. Parry, Franklin, and Richardson, near
the north polo ; Thieneraann in Iceland ; Gieseke in Green-
land ; Lotiifi and Bravais, near the North Cape ; Wrangel
and Anjou, on the coast of the Polar Sea, have together seen
the Aurora thousands of times, but never heard any sound
attending the phenomenon. If this negative testimony should
not be deemed equivalent to the positive counter-evidence of
Hearne on the mouth of the Copper River and of Henderson
in Iceland, it must be remembered that, although Hood heard
a noise as of quickly-moved musket-balls and a slight crack-
ing sound during an Aurora, he also noticed the same noise
on the following day, when there was no northern light to be
seen ; and it must not be forgotten that Wrangel and Gieseke
were fully convinced that the sound they had heard was to
be ascribed to the contraction of the ice and the crust of the
snow on the sudden cooling of the atmosphere. The belief
in a crackhng sound has arisen, not among the people gener-
ally, but rather among learned travelers, because in earlier
times the northern light was declared to be an effect of atmos-
pheric electricity, on account of the luminous manifestation
of the electricity in rarefied space, and the observers found it
easy to hear what they wished to hear. Recent experiments
with very sensitive electrometers have hitherto, contrary to
the expectation generally entertained, yielded only negative
results. The condition of the electricity in the atmosphere.*

* [Mr. .Tames Glaisher, of the Royal Observatory, Greenwich, in his
interesting Remarks on the Weather during the Quarter ending Decern,'
ber Zlst, 1847, says, " It is a fact well worthy of notice, that from the
beginning of this quarter till the 29th of December, the electricity of
the atmosphere was almost always in a neutral state, so that no signs of
electricity were shown for several days together by any of the electric-
al instruments." During this period there were dght exhibitions of
the Aurora Borealis, of which one was the peculiarly bright display of
the meteor on the 24th of October. These frequent exhibitions of brill-
iant Auroras sesii to depend upon many remarkable meteorological re-
lations, for we find, according to Mr. Glaisher's statement in the paper
to which we have already alluded, that the previous fifty years aflbrd
nc parallel season to the closing one of 1847. The mean temperature
of evaporation and of the dew point, the mean elastic force of vapor,
the mean reading of the barometer, and the mean daily range of the
readings of the thermometers in air, were all greater at Greenwich
during that season of 1847 than the average range of many preceding
years."] — Tr.

AURORA BOREALIS. 201

is not found to be changed during the most intense Aurora ;
but, on the other hand, the three expressions of the power of
terrestrial magnetism, decHnation, incHnation, and intensity,
are all affected by polar light, so that in the same night, and
at different periods of the magnetic development, the same
end of the needle is both attracted and repelled. The.asser
tion made by Parry, on the strength of the data yielded by
his observations in the neighborhood of the magnetic pole at
Melville Island, that the Aurora did not disturb, but rathei
exercised a calming influence on the magnetic needle, has been
satisfactorily refuted by Parry's own more exact researches, =^
detailed in his journal, and by the admirable observations of
Richardson, Hood, and Franklin in l!^orthern Canada, and
lastly by Bravais and Lottin in Lapland. The process of the
Aurora is, as has already been observed, the restoration of a
disturbed condition of equilibrium. The effect on the needle
is different according to the degree of intensity of the explo-
sion. It was only unappreciable at the gloomy winter station
of Bosekop when the phenomenon of light was very faint and
low in the horizon. The shooting cylinders of rays have been
aptly compared to the flame which rises in the closed circuit
of a voltaic pile between two points of carbon at a considera-
ble distance apart, or, according to Fizeau, to the flame rising
between a silver and a carbon point, and attracted or repelled
by the magnet. This analogy certainly sets aside the neces-
sity of assuming the existence of metallic vapors in the atmos-
phere, which some celebrated physicists have regarded as the
substratum of the northern light.

When we apply the indefinite term 'polar light to the lumin-
ous phenomenon which we ascribe to a galvanic current, that
is to say, to the motion of electricity in a closed circuit, we
merely indicate the local direction in which the evolution of
light is most frequently, although by no means invariably,
seen. This phenomenon derives the greater part of its im-
portance from the fact th^-t the Earth becomes self-lumin&us,
and that as a planet, besides the light which it receives from
the central body, the Sun, it shows itself capable in itself of
developing light. The intensity of the terrestrial light, or,
rather, the luminosity which is diffused, exceeds, in cases of
the brightest colored radiation toward the zenith, the light
of the Moon in its first quarter. Occasionally, as on the 7th
of January, 1831, printed characters could be read without
difficulty. This almost uninterrupted development of light
* Kiimtz, Lehrbuch der Meteorologie, bd. iii., s. 498 und 501.
I 2

202 COSMOS.

in the Earth leads us by analogy to the remarkable process
exhibited in Venus. The portion of this planet which is not
illumined by the Sun often shines with a phosphorescent light
of its own. It is not improbable that the Moon, Jupiter, and
the comets shine with an independent light, besides the re-
flected solar light visible through the polariscope. Without
speaking of the problematical but yet ordinary mode in which
the sky is illuminated, when a low cloud may be seen to shine
with an uninterrupted flickering light for many minutes to-
gether, we still meet with other instances of terrestrial develop-
ment of light in our atmosphere. In this category we may
reckon the celebrated luminous mists seen in 1783 and 1831 ;
the steady luminous appearance exhibited without any flick-
ering in great clouds observed by Rozier and Beccaria ; and
lastly, as Arago* well remarks, the faint diffused light which
guides the steps of the traveler in cloudy, starless, and moon-
less nights in autumn and winter, even when there is no snow
on the ground. As in polar light or the electro-magnetic
storm, a current of brilliant and often colored light streams
through the atmosphere in high latitudes, so also in the torrid
zones between the tropics, the ocean simultaneously develops
light over a space of many thousand square miles. Here tli«j
magical effect of light is owing to the forces of organic nature.
Foaming with light, the eddying waves flash in phosphores-
cent sparks over the wide expanse of waters, where every scin-
tillation is the vital manifestation of an invisible animal world.
So varied are the sources of terrestrial light ! Must we still
suppose this light to be latent, and combined in vapors, in
order to explain Moser's images produced at a distance — a
discovery in which reality has hitherto manifested itself like
a mere phantom of the imagination.

As the internal heat of our planet is connected on the one
hand with the generation of electro-magnetic currents and
the procojjs of terrestrial light (a consequence of the magnetic
storm), it, on the other hand, disclo'ses to us the chief source
of geognostic phenomena. We shall consider these in their
connection with and their transition from merely dynamic dis-
turbances, from the elevation of whole continents and mount-
am chains to the development and effusion of gaseous and

* Arago, on the dry fogs of 1783 and 1831, which illuminated the
night, in the Annuairedu Bureau des Longitudes, 1832, p. 246 and 250;
and, regarding extraordinary luminous appearances in clouds without
storms, see Notices sur la. Tonnerre, in the Annuairp pour Van. 1838,
p. 279-285.

— GEOaNOSTIC PHENOMENA. 203

liquid fluids, of hot mud, and of those heated and molten
earths which become soHdified into crystalhne mineral masses.
Modern geognosy, the mineral portion of terrestrial physics,
has made no slight advance in having investigated this con
nection of phenomena. This investigation has led us away
from the delusive hypothesis, by which it was customary for-
merly to endeavor to explain, individually, every expression of
force in the terrestrial globe : it shows us the connection of
the occurrence of heterogeneous substances with that which
only appertains to changes in space (disturbances or eleva-
tions), and groups together phenomena which at first sight
appeared most heterogeneous, as thermal springs, efiusion of
carbonic acid and sulphurous vapor, innocuous salses (mud
eruptions), and the dreadful devastations of volcanic mount-
ains.* In a general view of nature, all these phenomena are
fused together in one sole idea of the reaction of the interior
of a planet on its external surface. We thus recognize in the
depths of the earth, and in the increase of temperature with
the increase of depth from the surface, not only the germ of
disturbing movements, but also of the gradual elevation of
whole continents (as mountain chains on long fissures), of vol-
canic eruptions, and of the manifold production of mountains
and mineral masses. The influence of this reaction of the
interior on the exterior is not, however, limited to inorganic
nature alone. It is highly probable that, in an earlier world,
more powerful emanations of carbonic acid gas, blended with
the atmosphere, must have increased the assimilation of car-
bon in vegetables, and that an inexhaustible supply of com-
bustible matter (lignites and carboniferous formations) must
have been thus buried in the upper strata of the earth by the
revolutions attending the destruction of vast tracts of forest.
We likewise perceive that the destiny of mankind is in part
dependent on the formation of the external surface of the earth,
the direction of mountain tracts and high lands, and on the
distribution of elevated continents. It is thus granted to the
inquiring mind to pass from link to link along the chain of
phenomena until it reaches the period when, in the solidifying
process of our planet, and in its first transition from the gas-
eous form to the agglomeration of matter, that portion of the
inner heat of the Earth was developed, which does not belong
to the action of the Sun.

* [See Mjintell's Wonders of Geology, 1848, vol. i., p. 34, 36, 105 ;
also Ly ell's Princip'es of Geology, vol. ii., and Daubeney On Volcanoes,
2d ed., 1848, Pnit ii , ch. xxxii., xxxiii.]— Tr.

204 COSsMOS.

In order to give a general delineation of the causal con»
nection of geognostical phenomena, we will begin with those
whose chief characteristic is dynamic, consisting in motion
and in change in space. Earthquakes manifest themselves
by quick and successive vertical, or horizontal, or rotatory vi-
brations.* In the very considerable number of earthquakes
which I have experienced in both hemispheres, alike on land
and at sea, the two first-named kinds of motion have often ap-
peared to me to occur simultaneously. The mine-like explo-
sion— the vertical action from beiow upward — was most strik-
ingly manifested in the overthrow of the town of Riobamba
in 1797, when the bodies of many of the inhabitants were
found to have been hurled to Cullca, a hill several hundred
feet in height, and on the opposite side of the River Lican.
The propagation is most generally effected by undulations in
a linear direction,! with a velocity of from twenty to twenty-
eight miles in a minute, but partly in circles of commotion or
large ellipses, in which the vibrations are propagated with
decreasing intensity from a center toward the circumference.
There are districts exposed to the action of two intersecting
circles of commotion. In Northern Asia, where the Father
of History, $ and subsequently Theophylactus Simocatta,^ de-
scribed the districts of Scythia as free from earthquakes, I
have observed the metalUferous portion of the Altai Mount-
ains under the influence of a two-fold focus of commotion, the
Lake of Baikal, and the volcano of the Celestial Mountain
(Thianschan).ll When the circles of commotion intersect one
another — when, for instance, an elevated plain lies between
two volcanoes simultaneously in a state of eruption, several
wave-systems may exist together, as in fluids, and not mu-
tually disturb one another. We may even suppose interfer-

* [See Daubeney On Volcanoes, 2d ed., 1848, p. 509.]— Tr.

t [On the linear direction of earthquakes, see Daubeney On Volca'
noes, p. 515.] — Tr.

X Herod, iv., 28. The prostration of the colossal statue of Memnon,
which has been again restored (Letroune, La Statue Vacate de Memnon,
1835, p. 25, 26), presents a fact in opposition to the ancient prejudice
that Egypt is free from earthquakes (Pliny, ii., 80) ; but the valley of
the Nile does lie external to the circle of commotion of Byzantium, the
Archipelago, and Syria (Ideler ad Aristot., Meteor., p. 584).

§ Saint-Martin, in the learned notes to Lebeau, Hist, du Bos Empire,
t. ix., p. 401.

11 Humboldt, Asie Centrale, t. ii., p. 110-118. In regard to the dif.
ference between agitation of the surface and of the strata lying beneath
it, see Gay-Lussac, in the Annales de Chimie et de Physique, t. xxii.. p
499.

EARTHaUAKES. 206

e7ice to exist here, as in the intersecting waves of sound. The
extent of the propagated waves of commotion will be increased
on the upper surface of the earth, according to the general law
of mechanics, by which, on the transmission of motion in elas-
tic bodies, the stratum lying free on the one side endeavors to
separate itself from the other strata.

Waves of commotion have been investigated by means of
the pendulum and the seismometer* with tolerable accuracy in
respect to their direction and total intensity, but by no means
with reference to the internal nature of their alternations and
their periodic intumescence. In the city of Quito, which lies
at the foot of a still active volcano (the Rucu Pichincha),
and at an elevation of 9540 feet above the level of the sea,
which has beautiful cupolas, high vaulted churches, and mass-
ive edifices of several stories, I have often been astonished
that the violence of the nocturnal earthquakes so seldom
causes fissures in the walls, while in the Peruvian plains os-
cillations apparently much less intense injure low reed cot-
tages. The natives, who have experienced many hundred
earthquakes, believe that the difference depends less upon the
length or shortness of the waves, and the slowness or rapidity
of the horizontal vibrations,! than on the uniformity of the
motion in opposite directions. The circling rotatory commo-
tions are the most uncommon, but, at the same time, the most
dangerous. Walls were observed to be twisted, but not thrown
down ; rows of trees turned from their previous paralld direc-

* [This instrument, in its simplest form, consists merely of a basin
filled with some viscid liquid, which, on the occurrence of a shock of
an earthquake of sufficient force to disturb the equilibrium of the
building in which it is placed, is tilted on one side, and the liquid made
to rise in the same direction, thus showing by its height the degree of
the disturbance. Professor J. Forbes has invented an instrument of
this nature, although on a greatly improved plan. It consists of a vert-
ical metal rod, having a ball of lead movable upon it. It is supported
upon a cylindrical steel wire, which may be compressed at pleasure by
means of a screw. A lateral movement, such as that of an earthquake,
which carries forward the base of the instrument, can only act upon the
ball through the medium of the elasticity of the wire, and the direction
of the displacement will be indicated by the plane of vibration of the
pendulum. A self-registering apparatus is attached to the machine.
See Professor J. Forbes's account of his invention in Edinb Phil. Trans.,
vol. XV., Part i.] — Tr.

t " Tutissimum est cum vibrat crispante fedificiorum crepitu ; et cum
intumescit assurgens alternoque motu residet, innoxium et cum concur-
rentia tecta contrario ictu arietant; quoniam alter motus alteri renititur.
Undantis inclinatio et fluctus more quaedara volutatio infesta est, aut cum
in unara partem totus se motus impellit." — Plin., ii., 82.

206 COSMOS.

tion ; and fields covered with different kinds of plants found
to be displaced in the great earthquake of Riobamba, in the
province of Quito, on the 4th of February, 1797, and in that
of Calabria, between the 5th of February and the 28th of
March, 1783 The phenomenon of the inversion or displace-
ment of fields and pieces of land, by which one is made to oc-
cupy the place of another, is connected with a translatory mo-
tion or penetration of separate terrestrial strata. When I
made the plan of the ruined town of Riobamba, one particu-
lar spot was pointed out to me, where all the furniture of one
house had been found under the ruins of another. The loose
earth had evidently moved like a fluid in currents, which must
be assumed to have been directed first downward, then hori-
zontally, and lastly upward. It was found necessary to ap-
peal to the Audiencia, or Council of Justice, to decide upon
the contentions that arose regarding the proprietorship of ob-
jects that had been removed to a distance of many hundred
toises.

In countries where earthquakes are comparatively of much
less frequent occurrence (as, for instance, in Southern Europe),
a very general belief prevails, although unsupported by the
authority of inductive reasoning,* that a calm, an oppressive

* Even in Italy they have begun to observe that earthquakes are un-
connected with the state of the weather, that is to say, with the appear-
ance of the heavens immediately before the shock. The numerical re-
sults of Friedrich Hoffmann {Hinterlassene Werke, bd. ii., 366-375) ex-
actly correspond with the experience of the Abbate Scina of Palermo.
I have myself several times observed reddish clouds on the day of an
earthquake, and shortly before it; on the 4th of November, 1799, I ex-
perienced two sharp shocks at the moment of a loud clap of thunder.
(Relat. Hist., liv. iv., chap. 10.) The Turin physicist, Vassalli Eaudi,
observed Volta's electrometer to be strongly agitated during the pro-
tracted earthquake of Pignerol, which lasted from the 2d of April to
the 17th of May, 1808; Journal de Physique, t. Ixvii., p. 291. But
these indications presented by clouds, by modifications of atmospheric
electricity, or by calms, can not be regarded as generally or necessarily
connected with earthquakes, since in Quito, Peru, and Chili, as well
as in Canada and Italy, many earthquakes are observed along with the
purest and clearest skies, and with the freshest land and sea breezes.
But if no meteorological phenomenon indicates the coming earthquake
either on the morning of the shock or a few days previously, the influ-
ence of certain periods of the year (the vernal and autumnal equinoxes),
the commencement of the rainy season in the tropics after long drought,
and the change of the monsoons (according to general belief), can not
be overlooked, even though the genetic connection of meteorological
processes with those going on in the interior of our globe is still envel-
oped in obscurity. Numerical inquiries on the distribution of earth-
quakes throughout the course of the year, such as those of Von Hoff,
Peter Merian, and Friedrich Hoffmarn, bear testimony to their frequency

EARTHaUAKES. 207

leat, and a misty horizon, are always the forerunners of this
phenomenon. The fallacy of this popular opinion is not only
refuted by my own experience, but likewise by the observations
of all those who have lived many years in districts where, as
in Cumana, Quito, Peru, and Chili, the earth is frequently
and violently agitated. I have felt earthquakes in clear air
and a iresh east wind, as well as in rain and thunder storms.
The regularity of the horary changes in the declination of the
magnetic needle and in the atmospheric pressure remained un
disturbed between the tropics on the days when earthquakes
occurred.^ These facts agree with the observations made by
Adolph Erman (in the temperate zone, on the 8th of March,
1829) on the occasion of an earthquake at Irkutsk, near the
Lake of Baikal. During the violent earthquake of Cumana,
on the 4th of November, 1799, I found the declination and
the intensity of the magnetic force alike unchanged, but, to
my surprise, the inclination of the needle was diminished about
48 '.f There was no ground to suspect an error in the calcu-
lation, and yet, in the many other earthquakes which I have
experienced on the elevated plateaux of Quito and Lima, the
inclination as well as the other elements of terrestrial mag-
netism remained always unchanged. Although, in general,
the processes at work within the interior of the earth may not
be announced by any meteorological phenomena or any special
appearance of the skj^, it is, on the contrary, not improbable,
as we shall soon see, that in cases of violent earthquakes some
effect may be imparted to the atmosphere, in consequence of
which they can not always act in a purely dynamic manner.

at the periods of the equinoxes. It is singular that Pliny, at the end of
his fanciful theory of earthquakes, names the entire frightful phenom-
enon a subterranean storm; not so much in consequence of the rolling
sound which frequently accompanies the shock, as because the elastic
forces, concussive by their tension, accumulate in the interior of the
earth when they are absent in the atmosphere ! " Ventos in causa esse
non dubium reor. Neque enim unquam intremiscunt terras, nisi sopito
mari, coeloque adeo tranquillo, ut volatus avium non pendeant, subtracto
omni spiritu qui vehit; nee unquam nisi post ventos conditos, scilicet
in venas et cavernas ejus occulto afflatu. Neque aliud est in terra
tremor, quam in nube tonitruum ; nee hiatus aliud quam cum fulmen
erumpit, incluso spiritu luctante et ad libertatem exire nitente." (Phn.,
ii., 79.) The germs of almost every thing that has been observed or
imagined on the causes of earthquakes, up to the present day, may be
found in Seneca, Nat. Qucest., vi., 4-31.

* I have given proof that the course of the horary variations of the
uarometer is not affected before or after earthquakes, in my Relat. Hist.,
fc. i., p. 311 and 513.

t Humboldt, Relat. WU., t. i., p. 515-517.

208 COSMOS.

During the long-continued trembling of the ground in the
Piedmontese valleys of Pelis and Clusson, the greatest changes
in the electric tension of the atmosphere Were observed while
the sky was cloudless. The intensity of the hollow noise which
generally accompanies an earthquake does not increase in the
same degree as the force of the oscillations. I have ascertain-
ed with certainty that ths great shock of the earthquake of
R-iobamba (4th Feb., 1797) — one of the most fearful phenom-
ena recorded in the physical history of our planet — was not
accompanied by any noise whatever. The tremendous noise
{d gran ruido) which was heard below the soil of the cities
of Quito and Ibarra, but. not at Tacunga and Hambato, near-
er the center of the motion, occurred between eighteen and
twenty minutes after the actual catastrophe. In the cele-
brated earthquake of Lima and Callao (28th of October,
1746), a noise resembling a subterranean thunder-clap was
heard at Truxillo a quarter of an hour after the shock, and
unaccompanied by any trembling of the ground. In like
manner, long after the great earthquake in New Granada, on
the 16th of November, 1827, described by Boussingault, sub-
terranean detonations were heard in the whole valley of Cauca
during twenty or thirty seconds, unattended by motion. The
nature of the noise varies also very much, being either rolling,
or rustling, or clanking like chains when moved, or like near
thunder, as, for instance, in the city of Quito ; or, lastly, clear
and ringing, as if obsidian or some other vitrified masses were
struck in subterranean cavities. As solid bodies are excellent
conductors of sound, which is propagated in burned clay, for
instance, ten or twelve times quicker than in the air, the sub-
terranean noise may be heard at a great distance from the
place where it has originated. In Caraccas, in the grassy
plains of Calabozo, and on the banks of the Rio Apure, which
falls into the Orinoco, a tremendously loud noise, resembling
thunder, was heard, unaccompanied by an earthquake, over
a district of land 9200 square miles in extent, on the 30th of
April, 1812, while at a distance of 632 miles to the north-
east, the volcano of St. Vincent, in the small Antilles, poured
forth a copious stream of lava. With respect to distance, this
was as if an eruption of Vesuvius had been heard in the north
of France. In the year 1744, on the great eruption of the
volcano of Cotopaxi, subterranean noises, resembling the dis-
charge of cannon, were heard in Honda, on the Magdalena
River. The crater of Cotopaxi lies not only 18,000 feet high-
er than llonda, but these two points are separated by the co-

EARTHCIUAKES, 209

lossal mountain chain of Quito, Pasto, and Popayan, no less
than by numerous valleys and clefts, and they are 436 miles
apart. The sound was certainly not propagated through the
air, but through the earth, and at a great depth. During the
violent earthquake of New Granada, in February, 1835, sub-
terranean thunder was heard simultaneously at Popayan, Bo-
gota, Santa Marta, and Caraccas (where it continued for seven
hours without any movement of the ground), in Haiti, Jamai
oa, and on the Lake of Nicaragua.

These phenomena of sound, when unattended by any per-
ceptible shocks, produce a peculiarly deep impression even on
persons who have lived in countries where the earth has been
frequently exposed to shocks. A striking and unparalleled in-
stance of uninterrupted subterranean noise, unaccompanied by
any trace of an earthquake, is the phenomenon known in the
Mexican elevated plateaux by the name of the "roaring and
the subterranean thunder" (bramidos y truenos subterraneos)
of Guanaxuato.* This celebrated and rich mountain city
lies far removed from any active volcano. The noise began
about midnight on the 9th of Januajy, 1784, and continued
for a month. I have been enabled to give a circumstantial

* Oil the bramidos of Guanaxuato, see my Essai Polit. sur la Nouv.
Espagne, t. i., p. 303. The subterranean noise, unaccompanied with
any appreciable shock, in the deep mines and on the surface (the town
of Guanaxuato lies 6830 feet above the level of the sea), was not heard
in the neighboring elevated plains, but only in the mountainous parts
of the Sierra, from the Cuesta de los Aguilares, near Mai-fil, to the north
of Santa Rosa. There were individual parts of the Sierra 24-28 miles
northwest of Guanaxuato, to the other side of Chichimequillo, near the
boiling spring of San Jose de Comangillas, to which the waves of sound
did not extend. Extremely stringent measures were adopted by the
magistrates of the large mountain towns on the 14th of January, 1784,
when the terror produced by these subterranean thunders was at its
height. " The flight of a wealthy family shall be punished with a fine
of 1000 piasters, and that of a poor family with two months' imprison-
ment. The militia shall bring back the fugitives." One of the most
remarkable points about the whole affair is the opinion which the mag-
istrates (el cabildo) cherished of their own superior knowledge. In
one of their proclamas, I find the expression, '* The magistrates, in their
wisdom (en su sabiduria), will at once know when there is actual dan-
ger, and will give orders for flight; for the present, let processions be
instituted." The terror excited by the tremor gave rise to a famine,
pince it prevented the importation of com from the table-lands, where
it abounded. The ancients were also awai-e that noises sometimes ex-
isted without earthquakes. — Ai-istot., Meteor., ii., p. 802 ; Plin,, ii., 80.
The singular noise that was heard from March, 1822, to September,
1824, in the Dalmatian island Meleda (sixteen miles from Ragusa), and
on which Fartsch has thrown much light, was occasionally accompanied
by shocks.

210 COSMOS

description of it from the report of many witnesses, and from
the documents of the municipahty, of which I was allowed to
make use. From the 13th to the 16th of January, it seemed
to the inhabitants as if heavy clouds lay beneath their feet,
from which issued alternate slow rolling sounds and short,
quick claps of thunder. The noise abated as gradually as it
had begun. It was limited to a small space, and was not
heard in a basaltic district at the distance of a few miles.
Almost all the inhabitants, in terror, left the city, in which
large masses of silver ingots were stored ; but the most cour-
ageous, and those more accustomed to subterranean thunder,
soon returned, in order to drive off the bands of robbers who
had attempted to possess themselves of the treasures of the
city. Neither on the surface of the earth, nor in mines 1600
feet in depth, was the slightest shock to be perceived. No
similar noise had ever before been heard on the elevated table-
land of Mexico, nor has this terrific phenomenon since occurred
there. Thus clefts are opened or closed in the interior of the
earth, by which waves of sound penetrate to us or are impeded
in their propagation. #

The activity of an igneous mountain, however terrific and
picturesque the spectacle may be which it presents to our con-
templation, is always limited to a very small space. It is far
otherwise with earthquakes, which, although scarcely per-
ceptible to the eye, nevertheless simultaneously propagate their
waves to a distance of many thousand miles. The great
earthquake which destroyed the city of Lisbon on the 1st of
November, 1755, and whose effects were so admirably investi-
gated by the distinguished philosopher Emmanuel Kant, was
felt in the Alps, on the coast of Sweden, in the Antilles, An-
tigua, Barbadoes, and Martinique ; in the great Canadian
Lakes, in Thuringia, in the flat country of Northern Ger-
many, and in the small inland lakes on the shores of the Bal-
tic.^ Remote springs were interrupted in their flow, a phe-
nomenon attending earthquakes which had been noticed among
the ancients by Demetrius the Callatian. The hot springs of
Tophtz dried up, and returned, inundating every thing around,
and having their waters colored with iron ocher. In Cadiz

* [It has been computed, that the shock of this earthquake pervaded
an area of 700,000 miles, or the twelfth part of the circumference of the
globe. This dreadful shock lasted only five minutes: it happened about
nine o'clock in the morning of the Feast of All Saints, when almost the
whole population was within the churches, owing to which circum-
stance no less than 30,000 persons perished by the fall of these edificea^.
Bee DaubeneyOn Volcanoes, p. 514-517.] — Tr

EARTHCIUAKES. 211

the sea rose to an elevation of sixty-four feet, while in the An-
tilles, where the tide usually rises only from twenty-six to
twenty-eight inches, it suddenly rose above twenty feet, the
water being of an inky blackness. It has been computed that
on the 1st of November, 1755, a portion of the Earth's sur-
face, four times greater than that of Eurbpe, was simultane-
ously shaken. As yet there is no manifestation offeree known
to us, including even the murderous inventions of our own
race, by which a greater number of people have been killed in
the short space of a few minutes : sixty thousand were de-
stroyed in Sicily in 1693, from thirty to forty thousand in the
earthquake of Riobamba in 1797, and probably five times as
many in Asia Minor and Syria, under Tiberius and Justinian
the elder, about the years 19 and 526.

There are instances in which the earth has been shaken for
many successive days in the chain of the Andes in South
America, but I am only acquainted with the following cases
in which shocks that have been felt almost every hour for
months together have occurred far from any volcano, as, for
instance, on the eastern declivity of the Alpine chain of Mount
Cenis, at Fenestrelles and Pignerol, from April, 1808 ; be-
tween New Madrid and Little Prairie,* north of Cincinnati,
m the United States of America, in December, 1811, as well
as through the whole winter of 1812 ; and in the Pachalik of
Aleppo, in the months of August and September, 1822. As
the mass of the people are seldom able to rise to general views,
and are consequently always disposed to ascribe great phe-
nomena to local telluric and atmospheric processes, wherever
the shaking of the earth is continued for a long time, fears of
the eruption of a new volcano are awakened. In some few
cases, this apprehension has certainly proved to be well ground-
ed, as, for instance, in the sudden elevation of volcaiiic islands,
and as we see in the elevation of the volcano of Jorullo, a
mountain elevated 1684 feet above the ancient level of the
neighboring plain, on the 29th of September, 1759, afterninety
days of earthquake and subterranean thunder.

If we could obtain information regarding the daily condi-
tion of all the earth's surface, we should probably discover that
the earth is almost always undergoing shocks at some point
of its superficies, and is continually infiuenced by the reaction

* Drake, Nat. and Statist. Vieto of Cincinnati, p. 232-238 ; Mitchell,
in the Transactions of the Lit. and Philos. Soc. of New York, vol. i., p.
281-308. In the Piedmontese county of Pignerol, glasses of water, filled
to the very brim, axhibited for hours a continuous motion.

212

COSMOS.

of the interior on the exterior. The frequency and general
prevalence of a phenomenoji which is probably dependent on
the raised temperature of the deepest molten strata explain
its independence of the nature of the mineral masses in which
it manifests itself Earthquakes have even been felt in the
loose alluvial strata of Holland, as in the neighborhood ofMid-
dleburg andVliessingen on the 23d of February, 1828. Gran-
ite and mica slate are shaken as well as limestone and sand-
Btone, or as trachyte and amygdaloid. It is not, therefore, the
chemical nature of the constituents, but rather the mechanical
structure of the rocks, which modifies the propagation of the
motion, the wave of commotion. Where this wave proceeds
along a coast, or at the foot and in the direction of a mountain
chain, interruptions at certain points have sometimes been re-
marked, which manifested themselves during the course of
many centuries. The undulation advances in the depths be-
low, but is never felt at the same points on the surface. The
Peruvians* say of these unmoved upper strata that " they
form a bridge." As the mountain chains appear to be raised
on fissures, the walls of the cavities may perhaps favor the di-
rection of undulations parallel to them ; occasionally, however,
the waves of commotion intersect several chains almost per
pendicularly. Thus we see them simultaneously breaking
through the littoral chain of Venezuela and the Sierra Parime.
In Asia, shocks of earthquakes have been propagated from
Lahore and from the foot of the Himalaya (22d of January,
1832) transversely across the chain of the Hindoo Chou to
Badakschan, the upper Oxus, and even to Bokhara.f The
circles of commotion unfortunately expand occasionally in con-
sequence of a single and unusually violent earthquake. It is
only since the destruction of Cumana, on the 14th of Decem-
ber, 1797, that shocks on the southern coast have been felt in
the mica slate rocks of the peninsula of Maniquarez, situated
opposite to the chalk hills of the main land. The advancf^

* In Spanish they say, rocas que hacen puente. With, this phenome-
non of non-propagation through superior strata is connected the remark
able fact that in the beginning of this century shocks were felt in the
deep silver mines at Marienberg, in the Saxony mining district, while
not the slightest trace was perceptible at the surface. The mmers
ascended in a state of alarm. Conversely, the workmen in the mines
of Falun and Persberg felt nothing of the shocks which in November,
1823, spread dismay among the inhabitants above ground.

t Sir Alex. Burnes, Travels in Bokhara, vol. i., p. 18; and Wathen
Mem. on the Usbek State, in the Journ -2 of the Asiatic Society of Bengal,
vol. iii., p. 337.

EAKTfiaUAKES. 213

*rom south to north was very striking in the almost uninter-
rupted undulations of the soil in the alluvial valleys of the Mis-
sissippi, the Arkansas, and the Ohio, from 1811 to 1813. It
seemed here as if subterranean obstacles were gradually over-
come, and that the way being once opened, the undulatory
movement could be freely propagated.

Although earthquakes appear at first sight to be simply dy-
namic phenomena of motion, we yet discover, from well-at-
tested facts, that they are not only able to elevate a whole dis-
trict above its ancient level (as, for instance, the UUa Bund,
after the earthquake of Cutch, in June, 1819, east of the
Delta of the Indus, or the coast of Chili, in November, 1822),
but we also find that various substances have been ejected dur-
ing the earthquake, as hot water at Catania in 1818 ; hot
steam at New Madrid, in the Valley of the Mississippi, in
1812 ; irrespirable gases, Mofettes, which injured the flocks
grazing in the chain of the Andes ; mud, black smoke, and
even flames, at Messina in 1781, and at Cumana on the 14th
of November, 1797. During the great earthquake of Lisbon,
on the 1st of November, 1755, flames and columns of smoke
were seen to rise from a newly-formed fissure in the rock of
Alvidras, near the city. The smoke in this case became more
dense as the subterranean noise increased in intensity. =^ At
the destruction of Riobamba, in the year 1797, when the
shocks were not attended by any outbreak of the neighboring
volcano, a singular mass called the Moya was uplifted from
the earth in numerous continuous conical elevations, the whole
being composed of carbon, crystals of augite, and the silicious
shields of infusoria. The eruption of carbonic acid gas from
fissures in the Valley of the Magdalene, during the earthquake
of New Granada, on the 1 6th of November, 1827, suffocated
many snakes, rats, and other animals. Sudden changes of
weather, as the occurrence of the rainy season in the tropics,
at an unusual period of the year, have sometimes succeeded
violent earthquakes in Quito and Peru. Do gaseous fluids rise
from the interior of the earth, and mix with the atmosphere ?
or are these meteorological processes the action of atmospheric
electricity disturbed by the earthquake ] In the tropical re-
gions of America, where sometimes not a drop of rain falls for
ten months together, the natives consider the repeated shocks
of earthquakes, which do not endanger the low reed huts, as
auspicious harbingers of fruitfulness and abundant rain.

* Philos. Transact., vol. xlix. p. 414.

214 COSMOS.

The intimate connection of the phenomena which we havi
considered is still hidden in obscurity. Elastic fluids are doubt
lessly the cause of the slight and perfectly harmless trembling
of the earth's surface, which has often continued several dayt
(as in 1816, at Scaccia, in Sicily, before the volcanic eleva-
tion of the island of Julia), as well as of the terrific explosiona
accompanied by loud noise. The focus of this destructive agent,
the seat of the moving force, lies far below the earth's surface ;
but we know as little of the extent of this depth as we know
of the chemical nature of these vapors that are so highly com-
pressed. At the edges of two craters, Vesuvius, and the tow
ering rock which projects beyond the great abyss of Pichin-
cha, near Quito, I have felt periodic and very regular shocks of
earthquakes, on each occasion from 20 to 30 seconds before
the burning scoriae or gases were erupted. The intensity of
the shocks was increased in proportion to the time interven-
ing between them, and, consequently, to the length of timo
in which the vapors were accumulating. This simple fact,
which has been attested by the evidence of so many travelers,
furnishes us with a general solution of the phenomenon, in
showing that active volcanoes are to be considered as safety-
valves for the immediate neighborhood. The danger of earth-
quakes increases when the openings of the volcano are closed,
and deprived of free communication with the atmosphere ; but
the destruction of Lisbon, of Caraccas, of Lima, of Cashmir in
1554,* and of so many cities of Calabria, Syria, and Asia Mi-
nor, shows us, on the whole, that the force of the shock is not
the greatest in the neighborhood of active volcanoes.

As the impeded activity of the volcano acts upon the shocks
of the earth's surface, so do the latter react on the volcanic
phenomena. Openings of fissures favor the rising of cones of
eruption, and the processes which take place in these cones,
by forming a free communication with the atmosphere. A
column of smoke, which had been observed to rise for months
together from the volcano of Paste, in South America, sud-
denly disappeared, when, on the 4th of February, 1797, the
province of Quito, situated at a distance of 192 miles to the
south, suffered from the great earthquake of Riobamba. After
the earth had continued to tremble for some time through-
out the whole of Syria, in the Cyclades, and in Euba3a, the
shocks suddenly ceased on the eruption of a stream of hot mud

* On the frequency of earthquakes in Cashmir, see Troyer's German
translation of the ancient Radjataringini, vol. ii., p. 297, and Carl f
Httgel, Reisen, bd. ii., s. 184.

EARTHaUAKES. 215

on tlie Lelantine plains near Chalcis * The intelligent geog
rapher of Amasea, to whom we are indebted for the notice of
this circumstance, further remarks : " Since the craters of ^tna
have been opened, which yield a passage to the escape of fire,
and since burning masses and water have been ejected, the coun-
try near the sea-shore has not been so much shaken as at the
time previous to the separation of Sicily from Lower Italy, when
all communications with the external surface were closed."

We thus recognize in earthquakes the existence of a vol-
canic force, which, although every where manifested, and as
generally diffused as the internal heat of our planet, attains
but rarely, and then only at separate points, sufficient intensity
to exhibit the phenomenon of eruptions. The formation of
veins, that is to say, the filling up of fissures with crystalline
masses bursting forth from the interior (as basalt, melaphyre,
and greenstone), gradually disturbs the free intercommunica-
tion of elastic vapors. This tension acts in three difierent
ways, either in causing disruptions, or sudden and retroversed
elevations, or, finally, as was first observed in a great part of
Sweden, in producing changes in the relative level of the sea
and land, which, although continuous, are only appreciable at
intervals of long period.

Before we leave the important phenomena which we have
considered, not so much in their individual characteristics as
in their general physical and geognostical relations, I would
advert to the deep and peculiar impression left on the mind by
the first earthquake which we experience, even where it is not
attended by any subterranean noise.t This impression is not,

* Strabo, lib. i., p. 100, Casaub. That the expression tztjIov ScaTci)-
pov TTora/jtov does not mean erupted mud, but lava, is obvious from a
passage in Strabo, lib. vi., p. 412. Compare Walter, in his Abnakme der
Vulkanischen ThdtigkeU in Historischen Zeiten (On the Decrease of Vol-
canic Activity during Historical Times), 1844, s. 25.

t [Dr. Tschudi, in his interesting work. Travels in Peru, translated
from the German by Thomasina Ross, p. 170, 1847, describes striking-
ly the effect of an earthquake upon the native and upon the stranger.
** No familiarity with the phenomenon can blunt this feeling. The in-
habitant of Lima, who from childhood has frequently witnessed these
convulsions of nature, is roused from his sleep by the shock, and rushes
from his apartment with the cry of Miaericordia ! The foreigner from
the north of Europe, who knows nothing of earthquakes but by descrip
tion, waits with impatience to feel the movement of the earth, and longs
<,o hear with his own ear the subterranean sounds which he has hitherto
considered fabulous. With levity he treats the apprehension of a com-
ing convulsion, and laughs at the fears of the natives ; but, as soon as his
wish is gratified, he is terror-stricken, and is involuntarily prompted to
seek safety in flight."] — Tr.

216

COSMOS.

in my opinion, the result of a recollection of those fearful pic-
tures of devastation presented to our imaginations by the his-
torical narratives of the past, but is rather due to the sudden
revelation of the delusive nature of the inherent faith by which
we had clung to a belief in the immobility of the solid parts
of the earth. We are accustomed from early childhood to
draw a contrast between the mobility of water an i the im-
mobility of the soil on which we tread ; and this feeling is con-
firmed by the evidence of our senses. When, therefore, we
suddenly feel the ground move beneath us, a mysterious and
natural force, with which we are previously unacquainted, is
revealed to us as an active disturbance of stability. A moment
destroys the illusion of a whole life ; our deceptive faith in the
repose of nature vanishes, and we feel transported, as it were,
into a realm of unknown destructive forces. Every sound —
the faintest motion in the air — arrests our attention, and we
no longer trust the ground on which we stand. Animals, es-
pecially dogs and swine, participate in the same anxious dis-
quietude ; and even the crocodiles of the Orinoco, which are
at other times as dumb as our little lizards, leave the trem-
bling bed of the river, and run with loud cries into the adjacent
forests.

To man the earthquake conveys an idea of some universal
and unlimited danger. We may flee from the crater of a vol-
cano in active eruption, or from the dwelling whose destruc-
tion is threatened by the approach of the lava stream ; but in
an earthquake, direct our flight whithersoever we will, we still
feel as if we trod upon the very focus of destruction. This con-
di tion of the mind is not of long duration, although it takes its
origin in the deepest recesses of our nature ; and when a se-
ries of faint shocks succeed one another, the inhabitants of the
country soon lose every trace of fear. On the coasts of Peru,
where rain and hail are unknown, no less than the rolling
thunder and the flashing lightning, these luminous explosions
of the atmosphere are replaced by the subterranean noises
which accompany earthquakes.* Long habit, and the very

* [" Along the whole coast of Pein the atmosphere is almost uni-
formly in a state of repose. It is not illuminated by the lightning's flash,
or disturbed by the roar of the thunder; no deluges of rain, no fierce
hurricanes, destroy the fruits of the fields, and with them the hopes of
the husbandman. But the mildness of the elements above ground is
frightfully counterbalanced by their subterranean fury. Lima is fre
quently visited by earthquakes, and several times the city has beeu
reduced to a mass of ruins. At an average, forty-five shocks may bo
counted on in the year. Most of them occur in the latter part of Octo-

GAStoUtw EMANATIONb. 217

prevalent opinion that dangerous shocks are only to be appre-
hended two or three times in the course of a century, cause
faint oscillations of the soil to be regarded in Lima with scarce-
ly more attention than a hail storm in the temperate zone.

Having tHus taken a general view of the activity — the
inner life, as it were — of the Earth, in respect to its internal
heat, its electro-magnetic tension, its emanation of light at the
poles, and its irregularly-recurring phenomena of motion, we
will now proceed to the consideration of the material products,
the chemical changes in the earth's surface, and the composi-
tion of the atmosphere, which are all dependent on planetary
vital activity. We see issue from the ground steam and
gaseous carbonic acid, almost always free from the admixture
of nitrogen ;* carbureted hydrogen gas, which has been used
in the Chinese province Sse-tschuanf for several thousand
years, and recently in the village of Fredonia, in the State of
New York, United States, in cooking and for illumination ;
sulphureted hydrogen gas and sulphurous vapors ; and, more
rarely, $ sulphurous and hydrochloric acids. § Such effusions

D*ir, in November, December, January, May, and June. Experience
gives reason to expect the visitation of two desolating earthquakes in a
century. The period between the two is from forty to sixty years. The
most considerable catastrophes experienced in Lima since Europeans
have visited the west coast of South America happened in the years
1586, 1630, 1687, 1713, 1746, 1806. There is reason to fear that in the
course of a few years this city may be the prey of another such visita-
tion."— Tschudi, op. cit.] — Tr.

* Bischof's comprehensive work, Wdrmelekre des inneren Erdkorpers.

t On the Artesian fire-springs (Ho-tsing) in China, and the ancient
use of portable gas (in bamboo canes) in the city of Khiung-tsheu, see
Klaproth, in my Asie Cenirale, t. iii., p. 519-530.

t Boussingault (Annates de Chimie, t. Iii., p. 181) observed no evolu-
tion of hydrochloric acid from the volcanoes of New Granada, while
Monticelli found it in enormous quantity in the eruption of Vesuvius in
1813.

$ [Of the gaseous compounds of sulphur, one, sulphurous acid, ap-
pears to predominate chiefly in volcanoes possessing a certain degree
of activity, while the other, sulphureted hydrogen, has been most fre-
quently perceived among those is^ dormant condition. The occur-
rence of abundant exhalations of sulphuric acid, which have been hith
erto noticed chiefly in extinct volcanoes, as, for instance, in a stream
issuing from that of Purace, between Bogota and Quito, from extinct
volcanoes in Java, is satisfactorily explained in a recent paper by M.
Dumas, Annales de Chimie, Dec, 1846. He shows that when sulphu-
reted hydrogen, at a temperature above 100° Fahr., and still better
when near 190°, comes in contact with certain porous bodies, a cata-
lytic action is set up, by which water, sulphuric acid, and sulphur are
produced. Hence probably the vast deposits of 'sulphur, associated
with sulphates of lime and strontian, which are met with in the
western parts of Sicily.] — 7V.
Vol. I.— K.

218 COSMOS.

from the fissures of the earth not only occur in the distncta
of still burning or long-extinguished volcanoes, but they may
likewise be observed occasionally in districts where neither
trachyte nor any other volcanic rocks are exposed on the
earth's surface. In the chain of Quindiu I have seen sul-
phur deposited in mica slate from warm sulphurous vapor
at an elevation of 6832 feet* above the level of the sea,
while the same species of rock, which was formerly regarded
as primitive, contains, in the Cerro Cuello, near Tiscan, south
of Quito, an immense deposit of sulphur imbedded in pure
quartz.

Exhalations of carbonic acid {mofettes) are even in our days
to be considered as the most important of all gaseous emana-
tions, with respect to their number and the amount of their
effusion. We see in Germany, in the deep valleys of the
Eifel, in the neighborhood of the Lake of Laach,! in the
crater-like valley of the Wehr and in Western Bohemia, ex-
halations of carbonic acid gas manifest themselves as the last
efforts of volcanic activity in or near the foci of an earlier
World. In those earlier periods, when a higher terrestrial
temperature existed, and when a great number of fissures
still remained unfilled, the processes we have described acted
more powerfully, and carbonic acid and hot steam were mixed
in larger quantities in the atmosphere, from whence it follows,
as Adolph Brongniart has ingeniously shown,$ that the primi
tive vegetable world must have exhibited almost every where,
and independently of geographical position, the most luxurious
abundance and the fullest development of organism. In these
constantly warm and damp atmospheric strata, saturated with

* Humboldt, Recueil d'Observ. Astronomiques, t. i., p. 311 {Nivelle
ment Barom6trique de la Cordillere des Andes, No. 206).

t [The Lake of Laach, in the district of the Eifel, is an expanse of
water two miles in circumference. The thickness of the vegetation on
the sides of its crater-like basin renders it difficult to discover the nature
of the subjacent rock, but it is probably composed of black cellular
augitic lava. The sides of the cralgr present numerous loose masses,
which appear to have been ejected, and consist of glassy feldspar, ice-
spar, sodaHte, hauyne, spinellane, and leucite. The resemblance be-
tween these products and the masses formerly ejected from Vesuvius is
most remarkable. (Daubeney On Volcanoes, p. 81.) Dr. Hibbert re-
gards the Lake of Laach as formed in the first instance by a crack
caused by the cooling of the crust of the earth, which was widened
afterward into a circular cavity by the expansive force of elastic vapors.
See History of the pxtinct Volcanoes of the Basin of Neuwied, 1832.3
^Tr.

t Adolph Brongniart, in the Annalss des Sciences Naturelles, t. xv..
p. 225.

GASEOUS EMANATIONS. 219

carbonic acid, vegetation must have attained a degree of vital
activity, and derived the superabundance of nutrition necessary
to furnish materials for the formation of the beds of lignite
(coal), constituting the inexhaustible means on which are based
the physical power and prosperity of nations. Such masses
are distributed in basins over certain parts of Europe, occur-
ring in large quantities in the British Islands, in Belgium, in
France, in the provinces of the Lower Rhine, and in Upper
Silesia. At the same primitive period of universal volcanic
activity, those enormous quantities of carbon must also have
escaped from the earth which are contained in limestone
rocks, and which, if separated from oxygen and reduced to a
solid form, would constitute about the eighth part of the abso-
lute bulk of these mountain masses.* That portion of the
carbon which was not taken up by alkaline earths, but re-
mained mixed with the atmosphere, as carbonic acid, was
gradually consumed by the vegetation of the earlier stages of
the world, so that the atmosphere, after being purified by the
processes of vegetable life, only retained the small quantity
which it now possesses, and which is not injurious to the
present organization of animal life. Abundant eruptions of
sulphurous vapor have occasioned the destruction of the spe-
cies of mollusca and fish which inhabited the inland waters of
the earlier world, and have given rise to the formation of the
contorted beds of gypsum, which have doubtless been fre-
quently affected by shocks of earthquakes.

Gaseous and liquid fluids, mud, and molten earths, ejected
from the craters of volcanoes, which are themselves only a
kind of " intermittent springs,'' rise from the earth under pre-
cisely analogous physical relations.! All these substances owe
thoir temperature and their chemical character to the place
of their origin. The mean temperature of aqueous springs is
less than that of the air at the point whence they emerge, if
the water flow from a height ; but their heat increases with
the depth of the strata with which they are in contact at their
origin. We have already spoken of the numerical law regu-
lating this increase. The blending of waters that have come
from the height of a mountain with those that have sprung
from the depths of the earth, render it diflicult to determine
the position of the isogeothermal linest (lines of equal internal

* Bischof, op. cit., s. 324, Anm. 2.
t Humboldt, Asie Centrale, t. i., p. 43.

X On the theory of isogeothermal (chthonisothermal) lines, consult tha
ingenious labors of'Kupffer, in Pogg., Annalen, bd xv., s. 184, and bd.

220 COSMOS.

terrestrial temperature), when this determination is to be
'made from the temperature of flowing springs. Such, at any
rate, is the result I have arrived at from my own observations
and those of my fellow-travelers in Northern Asia. The
temperature of springs, which has become the subject of such
continuous physical investigation during the last half century,
depends, like the elevation of the line of perpetual snow, on
very many simultaneous and deeply- involved causes. It is a
function of the temperature of the stratum in which they take
their rise, of the specific heat of the soil, and of the quantity
and temperature of the meteoric water,* which is itself dif-
ferent from the temperature of the lower strata of the atmos-
phere, according to the different modes of its origin in rain,
finow, or hail.f

Cold springs can only indicate the mean atmospheric tem-

Kxxii., 8. 270, in the Voyage dans VOural, p. 382-398, and in the
Edinburgh Journal of Science, New Series, vol. iv., p. 355. See, also,
Kamtz, Lehrb. der Meteor., bd. ii., s. 217 ; and, on the ascent of the
chthonisothermal lines in mountainous districts, Bischof, s. 174-198.

* Leop. V. Buch, in Pogg., Annalen, bd. xii,, s. 405.

t On the temperature of the drops of rain in Cumana, which fell to
72^, when the temperature of the air shortly before had been 86° and
88°, and during the rain sank to 74°, see my Relat, Hist., t. ii., p. 22.
The rain-drops, while falling, change the normal temperature they
originally possessed, which depends on the height of the clouds from
which they fell, and their heating on their upper surface by the solar
rays. The rain-drops, on their first production, have a higher tempera-
ture than the surrounding medium in the superior strata of our atmos-
phere, in consequence of the liberation of their latent heat ; and they
continue to rise in temperature, since, in falling through lower and
warmer strata, vapor is precipitated on them, and they thus increase in
size (Bischof, Wdrmelehre des inneren Erdkorpers, s. 73); but this ad-
ditional heating is compensated for by evaporation. The cooling of the
air by rain (putting out of the question what probably belongs to the
electric process in storms) is effected by the drops, which are them-
selves of lower temperature, in consequence of the cold situation in
which they were formed, and bring down with them a portion of the
higher colder air, and which finally, by moistening the ground, give
rise to evaporation. These are the ordinary relations of the phenome-
non. When, as occasionally happens, the rain-drops are warmer than
the lower strata of the atmosphere (Humboldt, Rel. Hist., t. iii., p.
513), the cause must probably be sought in higher warmer currents, or
in a higher temperature of widely-extended and not very thick clouds,
from the action of the sun's rays. How, moreover, the phenomenon of
supplementary rainbows, which are explained by the interference of
light, is connected with the original and increasing size of the falling
drops, and how an optical phenomenon, if we know how to observe it
accurately, may enlighten us regarding a meteorological process, ac-
cording to diversity of zone, has been shown, with much talent and in
genuity, by Arago, in the Annuaire for 1836, p. 300.

HOT SPRINGS.

22,

perature when they are unmixed with the waters rising from
great depths, or descending from considerable mountain eleva-
tions, and when they have passed through a long course at a
depth from the surface of the earth which is equal in our lati-
tudes to 40 or 60 feet, and, according to Boussingault, to about
one foot in the equinoctial regions ;* these being the depths at
which the invariability of the temperature begins in the tem-
perate and torrid zones, that is to say, the depths at which
horary, diuiyjial, and monthly changes of heat in the atmosphere
cease to be perceived.

Hot springs issue from the most various kinds of rocks. The
hottest permanent springs that have hitherto been observed
are, as my own researches confirm, at a distance from all vol-
canoes. I will here advert to a notice in my journal of the
Aguas Calientes de las Tri7icheras,iR South America, between
Porto Cabello and Nueva Valencia, and the Aguas de Coman-
gillas, in the Mexican territory, near Guanaxuato ; the for-
mer of these, which issued from granite, had a temperature of
194°-5 ; the latter, issuing from basalt, 205° -5. The depth
)f the source from whence the water flowed with this temper-
ature, judging from what we know of the law of the increase
of heat in the interior of the earth, was probably 7140 feet,
or above two miles. If the universally-diffiised terrestrial
heat be the cause of thermal springs, as of active volcanoes,
the rocks can only exert an influence by their different capaci-

* The profound investigations of Boussingault fully convince me, that
in the tropics, the temperature of the ground, at a very slight depth, ex-
actly corresponds witli the mean temperature of the air. The follow
ing instances are sufficient to illustrate this fact :

stations within Tropical Zones.

Temperature at. 1 French
foot [1-006 of the English
foot] below the earth's
surface.

Mean Temper-
ature of the
air.

Height, in English
feet, above the
level of the sea.

GuavaQuil

78-8
74-6
70-7
64-7
59-9

78-1
74-8
70-7
65-6
59-9

0

3444
4018
5929
9559

Anserma Nuevo

2upia

Popayan

Quito

The doubts about the temperature of the earth within the tropics, of
which I am probably, in some degree, the cause, by ray observations
on the Cave of Caripe (Cueva del Guacharo), Rel. Hist., t. iii., p. 191-
196), are resolved by the consideration that I compared the presumed
mean temperature of the air of the convent of Caripe, 65°*3, not with
the temperature of the air of the cave, 65°-6, but with the temperature
of the subterranean stream, 62°-3, although I observed {Rel. Hist., t.
iii., p. 146 and 194) that mountain water from a great height might
probably be mixed with the water of the cave.

222 COSMOS.

ties for heat and by their conducting powers. The hottest of
all permanent springs (between 203° and 209°) are likewise,
in a most remarkable degree, the purest, and such as hold in
solution the smallest quantity of mineral substances. Their
temperature appears, on the whole, to be less constant than
that of springs between 122° and 165°, which in Europe, at
least, have maintained, in a most remarkable manner, their
invariability of heat and mineral contents during the last
fifty or sixty years, a period in which thermometri«al measure-
ments and chemical analyses have been applied with increas-
ed exactness. Boussingault found in 1823 that the thermal
springs of Las Trincheras had risen 12° during the twenty-
three years that had intervened since my travels in 1800.=^
This calmly- flowing spring is therefore now nearly 12° hotter
than the intermittent fountains of the Geyser and the Strokr,
whose temperature has recently been most carefully determ-
ined by Krug of Nidda. A very striking proof of the origin
of hot springs by the sinking of cold meteoric water into the
earth, and by its contact with a volcanic focus, is afforded by
the volcano of Jorulla in Mexico, which was unknown before
my American journey. When, in September, 1759, Jorullo
was suddenly elevated into a mountain 1183 feet above the
level of the surrounding plain, two small rivers, the Rio de
Cuitimba and Rio de San Fedro, disappeared, and some
time afterward burst forth again, during violent shocks of an
earthquake, as hot springs, whose temperature I found in 1803
to be 186°-4.

The springs in Greece still evidently flow at the same places
as in the times of Hellenic antiquity. The spring of Erasinos,
two hours' journey to the south of Argos, on the declivity of
Chaon, is mentioned by Herodotus. At Delphi we still see
Cassotis (now the springs of St. Nicholas) rising south of the
Lesche, and flowing beneath the Temple of Apollo ; Castalia,
at the foot of Phsedriadse ; Pirene, near Acro-Corinth ; and
the hot baths of ^dipsus, in Euboea, in which Sulla bathed
during the Mithridatic war.t I advert with pleasure to these

* Boussingault, in the Annahs de Chimie, t. lii., p. 181. The spring
of Chaudes Aigues, in Auvergne, is only 176°. It is also to be observ-
ed, that while the Aguas Calientes de las Trincheras, south of Porto
Cabello (Venezuela), springing from granite cleft in regular beds, and
far from all volcanoes, have a temperature of fully 206°'6, all the springs
which rise in the vicinity of still active volcanoes (Pasto, Cotopaxi, and
Tunguragua) have a temperature of only 97^-130°.

t Cassotis (the spring of St. Nich )las) and Castalia, at the PhaedriadfB,
mentioned iu Pausanias, x.,24, 25, and x., 8, 9 ; Pirene (Acro-Corinth)

HOT SPRINGS. 223

facts, as they show us that, even in a country subject to fre-
quent and violent shocks of earthquakes, the interior of our
planet has retained for upward of 2000 years its ancient con-
figuration in reference to the course of the open fissures that
yield a passage to these waters. The Fontaine jaillissante of
Lillers, in the Department des Pas de Calais, which was bored
as early as the year 1126, still rises to the same height and
yields the same quantity of water ; and, as another instance, I
may mention that the admirable geographer of the Carama-
nian coast, Captain Beaufort, saw in the district of Phaselis the
same flame fed by emissions of inflammable gas which was de-
scribed by Pliny as the flame of the Lycian Chimera.*

The observation made by Arago in 1821, that the deepest
Artesian wells are the warmest,! threw great light on the ori-
gin of thermal springs, and on the establishment of the law
that terrestrial heat increases with increasing depth. It is a
remarkable fact, which has but recently been noticed, that at
the close of the third century, St. Patricius,$ probably Bishop
of Pertusa, was led to adopt very correct views regarding the
phenomenon of the hot springs at Carthage. On being asked
what was the cause of boiling water bursting from the earth,
he replied, " Fire is nourished in the clouds and in the interior

in Strabo, p. 379 ; the spring of Erasinos, at Mount Chaon, south of Ar-
gos, in Herod., vi., 67, and Pausanias, ii., 24, 7 ; the springs of ^dipsus
in Euboea, some of which have a temperature of 88°, while in others it
ranges between 144° and 167°, in Strabo, p. 60 and 447, and Athenaeus,
ii., 3, 73 ; the hot springs of Thermopylae, at the foot of (Eta, with a
temperature of 149°. All from manuscript notes by Professor Curtius,
the learned companion of Otfried MUller.

* Pliny, ii., 106; Seneca, Ejiist., 79, $ 3, ed. Ruhkopf (Beaufort, iS^«r-
jey of the Coast of Karamania, 1820, art. Yanai', near Deliktasch, the
ancient Phaselis, p. 24). See, also, Ctesias, Fragm., cap. 10 p. 250,
ed. Bahr ; Strabo, lib. xiv,, p. QQQ, Casaub.

[" Not far from the Deliktash, on the side of a mountain, is the per-
petual fire described by Captain Beaufort. The travelers found it as
brilliant as ever, and even somewhat increased ; for, besides the large
Hame in the corner of the ruins described by Beaufort, there were small
jets issuing from crevices in the side of the crater-like cavity five or
six feet deep. At the bottom was a shallow pool of sulphureous and
turbid water, regarded by the Turks as a sovereign remedy for all skin
complaints. The soot deposited from the flames was regarded as effi-
cacious for sore eyelids, and valued as a dye for the eyebrows." See
the highly interesting and accurate work, Travels in Lycia, by Lieut.
Spratt and Professor E. Forbes.] — Tr.

t Arago, in the Annnaira pour 1835, p. 234.

X Acta S. Patricii, p. 555, ed. Ruinart, t. ii., p. 385, Mazochi. Du-
reau de la Malle was the first to draw attention to this remarkable pas-
sage in the Recherches siir la Topographir. de Carthage, 1835, p. 276
(See, also, Seneca, Nat. Qucest., iii., 24.)

224 COSMOS.

of the earth, as ^tna and other mountains near Napletj may
teach you. The subterranean waters rise as if through si*
phons. The cause of hot springs is this : waters which are
more remote from the subterranean fire are colder, while those
which rise nearer the fire are heated by it, and bring with
them to the surface which we inhabit an insupportable degree
of heat."

As earthquakes are often accompanied by eruptions of water
and vapors, we recognize in the Salses,^ or small mud vol-
canoes, a transition from the changing phenomena presented
by these eruptions of vapor and thermal springs to the more
powerful and awful activity of the streams of lava that flow
from volcanic mountains. If we consider these mountains as
springs of molten earths producing volcanic rocks, we must re-
member that thermal waters, when impregnated with carbonic
acid and sulphurous gases, are continually forming horizon-
tally ranged strata of limestone (travertine) or conical eleva-
tions, as in Northern Africa (in Algeria), and in the Baiios
of Caxamarca, on the western declivity of the Peruvian Cor-
dilleras. The travertine of Van Diemen's Land (near Hobart
Town) contains, according to Charles Darwin, remains of a
vegetation that no longer exists. Lava and travertine, which
are constantly forming before our eyes, present us with the
two extremes of geognostic relations.

Salses deserve more attention than they have hitherto re-
ceived from geognosists. Their grandeur has been overlooked
because of the two conditions to which they are subject ; it is
only the more peaceful state, in which they may continue for
centuries, which has generally been described : their origin is.
however, accompanied by earthquakes, subterranean thunder,
the elevation of a whole district, and lofty emissions of flame
of short duration. When the mud volcano of Jokmali began
to form on the 27th pf November, 1827, in the peninsula of
Abscheron, on the Caspian Sea, east of Baku, the flames
flashed up to an extraordinary height for three hours, while
during the next twenty hours they scarcely rose three feet
a])ove the crater, from which mud was ejected. Near the
village of Baklichli, west of Baku, the flames tose so high that

* [True volcanoes, as we have seen, generate sulphureted hydrogen
and muriatic acid, upheave tracts of land, and emit streams of melted
feldspalhic materials ; salses, on the contrary, disengage little else but
carbureted hydrogen, together with bitumen and other products of the
distillation of coal, and pour forth no other torrents except of mud, oi
argillaceous materials mixed up with water. Daubeney, op cit., p
640.]— yr.

sAi.sEs. 225

they could be seen at a distance of twenty-four miles. Enor*
mous masses of rock were torn up and scattered around. Sim-
ilar masses may be seen round the now inactive miud volcano
of Monte Zibio, near Sassuolo, in Northern Italy. The sec-
ondary condition of repose has been maintained for upward of
fifteen centuries in the mud volcanoes of Girgenti, the Maca-
.hibi, in Sicily, which have been described by the ancients.
These salses consist of many contiguous conical hills, from
eight to ten, or even thirty feet in height, subject to variations
of elevation as well as of form. Streams of argillaceous mud,
attended by a periodic development of gas, flow from the small
basins at the summits, which are filled with water ; the mud,
although usually cold, is sometimes at a high temperature, as
at Damak, in the province of Samarang, in the island of Java.
The gases that are developed with loud noise difier in their
nature, consisting, for instance, of hydrogen mixed with naph-
tha, or of carbonic acid, or, as Parrot and myself have shown
(in the peninsula of Taman, and in the Volcancitos de Tur-
haco, in South America), of almost pure nitrogen.*

Mud volcanoes, after the first violent explosion of fire, which
is not, perhaps, in an equal degree common to all, present to
the spectator an image of the uninterrupted but weak activity
of the interior of our planet. The communication with the
deep strata in which a high temperature prevails is soon closed,
and the coldness of the mud emissions of the salses seems to in-
dicate that the seat of the phenomenon can not bo far re-
moved from the surface during their ordinary condition. The
reaction of the interior of the earth on its external surface is
exhibited with totally different force in true volcanoes or igne-
ous mountains, at points of the earth in which a permanent,
or, at least, continually-renewed connection with the volcanic
force is manifested. We must here carefully distinguish be-
tween the more or less intensely developed volcanic phenom*
ena, as, for instance, between earthquakes, thermal, aqueous,
and gaseous springs, mud volcanoes, and the appearance of
bell-formed or dome-shaped trachytic rocks without openings ;
the opening of these rocks, or of the elevated beds of basalt, as

* Humboldt, Rel. Hist., t. iii., p. 562-567 ; Asie Centrale, t. i., p. 43;
t. ii., p. 595-515; Vues des Cordillcres, pi. xli. Regarding the Maca^
lubi (the Arabic Makhlub, the overthrown or inverted, iroxa the woi'd
Kkalaba), and on " the Earth ejecting fluid earth," see Solinus, cap. 5:
" idem ager Agrigentinus eructat limosas scaturigenes, et ut venae fon«
tium sufficiunt rivis subministraudis, ita in hac SiciliaB parte solo nun*
Quam deficierite, asterna rejectatione terrara terra evorait."

K2

COSMOS.

craters of elevation ; and, lastly, the ek vation of a permanent
volcano in the crater of elevation, or among the debris of its
earlier formation. At different periods, and in different de-
grees of activity and force, the permanent volcanoes emit
steam, acids, luminous scorisB, or, when the resistance can be
overcome, narrow, band-like streams of molten earths. Elas-
tic vapors sometimes elevate either separate portions of the
earth's crust into dome-shaped unopened masses of feldspathic
trachyte and dolerite (as in Puy de Dome and Chimborazo),
in consequence of some great or local manifestation of force in
the interior of our planet, or the upheaved strata are broken
through and curved in such a manner as to form a steep rocky
ledge on the opposite inner side, which then constitutes the in-
closure of a crater of elevation. If this rocky ledge has been
uplifted fiom the bottom of the sea, which is by no means al-
ways the case, it determines the whole physiognomy and form
of the island. In this manner has arisen the circular form of
Palma, which has been described with such admirable accu-
racy by Leopold von Buch, and that of Nisyros,* in the -^gean
Sea. Sometimes half of the annular ledge has been destroy-
ed, and in the bay formed by the encroachment of the sea cor-
allines have built their cellular habitations. Even on conti-
aents craters of elevation are often filled with water, and em-
bellish in a peculiar manner the character of the landscape.
Their origin is not connected with any determined species of
rock : they break out in basalt, trachyte, leucitic porphyry
(somma), or in doleritic mixtures of augite and labradorite ;
and hence arise the different nature and external conformation
of these inclosures of craters. No phenomena of eruptions are
manifested in such craters, as they open no permanent channel
of communication with the interior, and it is but seldom that
we meet with traces of volcanic activity either in the neigh-
borhood or in the interior of these craters. The force which
was able to produce so important an action must have been
long accumulating in the interior before it could overpower the
resistance of the mass pressing upon it ; 'it sometimes, for in-
Btance, on the origin of new islands, will raise granular rocks
and conglomerated masses (strata of tufa filled with marine
plants) above the surface of the sea. The compressed vapors
escape through the crater of elevation, but a large mass soon
falls back and closes the opening, which had been only formed
by these manifestations of force. No volcano can, therefore,

* See the interesting little map of the island of Nisyros, in Boss's
Reisen auj den Oriechischen Inseln, bd. ii., 1843, s. 69.

VOLCANOES. 227

be produced.* A volcano, properly so called, exists only where
a permanent connection is established between the interior of
the earth and the atmosphere, and the reaction of the interior
on the surface then continues during long periods of time. It
may be interrupted for centuries, as in the case of Vesuvius,
Fisove,t and then manifest itself with renewed activity. In
the time of Nero, men were disposed to rank -^tna among
the volcanic mountains which were gradually becoming ex-
tinct ;t and subsequently ^lian§ even maintained that mar-
iners could no longer see the sinking summit of the mountain
from so great a distance at sea. Where these evidences —
these old scaffoldings of eruption, I might almost say — still
exist, the volcano rises from a crater of elevation, while a high
rocky wall surrounds, like an amphitheater, the isolated con-
ical mount, and forms around it a kind of casing of highly ele-

* Leopold von Bucli, Phys. Beschreib'ifng der Canarischen Inseln, s.
326 ; and his Memoir uher Erhebungscratere und Vulcane, in Poggend.,
Annal., bd. xxxvii., s. 169.

In his remarks on the separation of Sicily from Calabria, Strabo gives
an excellent description of the two modes in w^hich islands are formed:
"Some islands," he observes (lib. vi., p. 258, ed. Casaub.), "are frag
ments of the continent, others have arisen from the sea, as even at the
present time is known to happen; for the islands of the great ocean,
lying far from the main land,. have j*obably been raised from its depths,
while, on the other hand, those near promontories appear (according to
reason) to have been separated from the continent."

t Ocre Fisove (Mens Vesuvius) in the Umbrian language. (Lassen,
Deutung der Eugubinischcn Tafeln in Rhein. Museum, 1832, s. 387.)
The word ochre is very probably genuine Umbrian, and means, accord-
ing to Festus, mountain. Mtna. would be a burning and shining mount-
ain, if Voss is correct in stating that AItvt) is an Hellenic sound, and is
connected with aWu and aldtvog ; but the intelligent writer Parthey
doubts this Hellenic origin on etymological grounds, and also because
^tna was by no means regarded as a luminous beacon for ships or
wanderers, in the same manner as the ever-travailing Stromboli (Stron-
gyle), to which Homer seems to refer in the Odyssey (xii., 68, 202,
and 219), and its geographical position was not so well determined. I
suspect that ^tua would be found to be a Sicilian word, if we had any
fragmentaiy materials to refer to. According to Diodorus (v., 6), the
Sicani, or aborigines preceding the Sicilians, were compelled to fly to
the westei'n part of the island, in consequence of successive eruptions
extending over many years. The most ancient eruption of Mount ^Etna
on record is that mentioned by Pindar and jEschylus, as occurring un-
der Hiero, in the second year of the 75th Olympiad. It is probable
that Hesiod was aware of the devastating eruptions of ^tna before the
period of Greek immigration. There is, however, some doubt regard-
ing the word AItvtj in the text of Hesiod, a subject into which I hava
entered at some length in another place. (Humboldt, Examen Crit
4e le Geogr., t. i., p. 168.)

t Seneia, Epist., 79. $ iElian, Var. Hist., viii.. 1 1

228 COSMOS.

vated strata. Occasionally not a trace of this inclosurt) is
visible, and the volcano, which is not always conical, rises
immediately from the neighboring plateau in an elongated
form, as in the case of Pichincha,* at the foot of which lies
the city of Quito.

As the nature of rocks, or the mixture (grouping) of simple
minerals into granite, gneiss, and mica slate, or into trachyte,
basalt, and dolorite, is independent of existing climates, and is
the same under the most varied latitudes of the earth, so also
we find every where in inorganic nature that the same laws of
configuration regulate the reciprocal superposition of the strata
of the earth's crust, cause them to penetrate one another in
the form of veins, and elevate them by the agency of elastic
forces. This constant recurrence of the same phenomena is
most strikingly manifested in volcanoes. When the mariner,
amid the islands of some distant archipelago, is no longer guid-
ed by the light of the same stars with which he had been fa-
miliar in his native latitude, and sees himself surrounded by
palms and other forms of an exotic vegetation, he still can
trace, reflected in the individual characteristics of the land-
scape, the forms of Vesuvius, of the dome-shaped summits of
Auvergne, the craters of elevation in the Canaries and Azores,
or the fissures of eruption in Iceland. A glance at the satel-
lite of our planet will impart a wider generalization to this anal-
ogy of configuration. By means of the charts that have been
drawn in accordance with the observations made with large
telescopes, we may recognize in the moon, where water and aii
are both absent, vast craters of elevation surrounding or sup-
porting conical mountains, thus affording incontrovertible evi-
dence of the effects produced by the reaction of the interior on
the surface, favored by the influence of a feebler force of grav*
itation.

Although volcanoes are justly termed in many languages
" fire - emitting mountains," mountains of this kind are not
formed by the gradual accumulation of ejected currents of
lava, but their origin seems rather to be a general consequence
of the sudden elevation of soft masses of trachyte or labrador-
itic augite. The amount of the elevating force is manifested

* [This mountain contains two funnel-shaped craters, apparently re
Bulting from two sets of eruptions: the western nearly circular, and
having in its center a cone of eruption, from the summit and sides of
which are no less than seventy vents, some in activity and others ex
tinct. It is probable that the larger number of the vents were ]wo
duced at periods anterior to history. Daubeney, op. cit., p. 488.] — 7'/

VOLCANOES. 229

by the elevation of the volcano, which varies from the incon-
siderable height of a hill (as the volcano of Cosima, one of the
Japanese Kurile islands) to that of a cone above 19,000 feet
in height. It has appeared to nie that relations of height have
a great influence on the occurrence of eruptions, w^hich are
more frequent in low than in elevated volcanoes. I might in-
stance the series presented by the following mountains : Strom-
boli, 23 1 8 feet ; Guacamayo, in the province of Quixos, from
which detonations are heard almost daily (I have myself often
heard them at Chillo, near Quito, a distance of eighty-eight
miles); Vesuvius, 3876 feet; .^tna, 10,871 feet; the Peak
of Teneriffe, 12,175 feet ; and Cotopaxi, 19,069 feet. If the
focus of these volcanoes be at an equal depth below the sur-
face, a greater force must be required where the fused masses
have to be raised to an elevation six or eight times greater
than that of the lower eminences. While the volcano Strom-
boli (Strong)4e) has been incessantly active since the Homeric
ages, and has served as a beacon-light to guide the mariner in
the Tyrrhenian Sea, loftier volcanoes have been characterized
by long intervals of quiet. Thus we see that a whole century
often intervenes between the eruptions of most of the colossi
which crown the summits of the Cordilleras of the Andes.
Where we meet with exceptions to this law, to which I long
since drew attention, they must depend upon the circumstance
that the connections between the volcanic foci and the crater
of eruption can not be considered as equally permanent in the
case of all volcanoes. The channel of communication may be
closed for a time in the case of the lower ones, so that they
less frequently come to a state of eruption, although they do
not, on that account, approach more nearly to their final ex-
tinction.

These relations between the absolute height and the fre
quency of volcanic eruptions, as far as they are externally per
ceptible, are intimately connected vAih. the consideration of
the local conditions under which lava currents are erupted.
Eruptions from the crater are very unusual in many mount-
ains, generally occurring from lateral fissures (as was observed
in the case of -^tna, in the sixteenth century, by the cele-
brated historian Bembo, when a youth*), wherever the sides

* Petri Bembi Opuscula {^tna Dialogus), Basil, 1556, p. 63 : " Quic-
quid in ^tnae matris utero coalescit, uunquam exit ex cratere superiore,
quod vel eo iuscoudere gravis materia nou queat, vel, quia inferius alia
Hpiramenta sunt, non fit opus. Despumant flammis urgentibus ignei riv'
pigro fluxu totas delambentes plagas, et in lapidem indurescunt."

;230 COSMOS.

of the upheaved mountain were least able, from their configu-
ration and position, to offer an}' resistance. Cones of eruption
are sometimes uplifted on these fissures ; the larger ones, which
are erroneously termed 7iew volcanoes,, are ranged together in a
line marking the direction of a fissure, which is soon reclosed,
while the smaller ones are grouped together, covering a whole
district with their dome-like or hive-shaped forms. To the
latter belong the hornitos de Jorullo,^ the cone of Vesuvius
erupted in October, 1822, that of Awatscha, according to Pos-
tels, and those of the lava-field mentioned by Erman, near the
Baidar Mountains, in the peninsula of Kamtschatka.

When volcanoes are not isolated in a plain, but surrounded,
as in the double chain of the Andes of Quito, by a table-land
having an elevation from nine to thirteen thousand feet, this
circumstance may probably explain the cause why no lava
streams are formedf during the most dreadful eruption of ig-
nited scoriae accompanied by detonations heard at a distance
of more than a hundred miles. Such are the volcanoes of Po-
payan, those of the elevated plateau of Los Pastes and of the
Andes of Quito, with the exception, perhaps, in the case of
the latter, of the volcano of Antisana. The height of the cone
of cinders, and the size and form of the crater, are elements
of configuration which yield an especial and individual char-
acter to volcanoes, although the cone of cinders and the crater
are both wholly independent of the dimensions of the mount-
ain. Vesuvius is more than three times lower than the Peak
of Teneriffe ; its cone of cinders rises to one third of the height
of the whole mountain, while the cone of cinders of the Peak
is only g^d of its altitude. $ In a much higher volcano than
that of Teneriffe, the Rucu Pichincha, other relations occur

* See my drawing of the volcano of Jorullo, of its hornitos, and of the
uplifted malpays, in my Vues de Cordilleres, pi. xliii., p. 239.

[Burckhardt states that during the twenty-four years that have inter-
vened since Baron Humboldt's visit to Jorullo, the hornitos have either
wholly disappeared or completely changed their forms. See Avfenthalt
und Reisen in Mexico in 1825 und 1834.] — Tr.

t Humboldt, Essai sur la Giogr. des Plantes et Tableau Phys. des Ri-
gions Equinoxiales, 1807, p. 130, and Essai G6ogn. sur le Gisement de*
Roches, p. 321. Most of the volcanoes in Java demonstrate that the
cause of the perfect absence of lava streams in volcanoes of incessant
activity is not alone to be sought for in their form, position, and height.
Leop. von Buch, Descr. Phys. des lies Canaries, p. 419 ; Reinwardt and
Hoffmann, in Poggend., Annalen., bd. xii., s. 607.

t [It may be remarked in general, although the rule is liable to ex-
ceptions, that the dimensions of a crater are in an inverse ratio to the
elevation of the mountain. Daubeney, op. cit., p. 444.] — ^Tr.

VOLCANOES 231

which approach more nearly to that of Vesuvius. Among all
the volcanoes that I have seen in the two hemispheres, the
conical form of Cotopaxi is the most beautifully regular. A
Budden fusion of the snow at its cone of cinders announces the
proximity of the eruption. Before the smoke is visible in the
rarefied strata of air surrounding the summit and the opening
of the crater, the walls of the cone of cinders are sometimes
in a state of glowing heat, when the whole mountain presents
an appearance of the most fearful and portentous blackness.
The crater, which, with very few exceptions, occupies the
summit of the volcano, forms a deep, caldron-like valley, which
is often accessible, and whose bottom is subject to constant al-
terations. The great or lesser depth of the crater is in many
volcanoes likewise a sign of the near or distant occurrence of
an eruption. Long, narrow fissures, from which vapors issue
forth, or small rounding hollows filled with molten masses, al-
ternately open and close in the caldron-like valley ; the bottom
rises and sinks, eminences of scoriae and cones of eruption are
formed, rising som^etimes far over the walls of the crater, and
continuing for years together to impart to the volcano a pecul-
iar character, and then suddenly fall together and disappear
during a new eruption. The openings of these cones of erup-
tion, which rise from the bottom of the crater, must not, as is
too often done, be confounded with the crater which incloses
them. If this be inaccessible from extreme depth and from
the perpendicular descent, as in the case of the volcano of
Rucu Pichincha, which is 15,920 feet in height, the traveler
may look from the edge on the summit of the mountains which
rise in the sulphurous atmosphere of the valley at his feet ;
and I have never beheld a grander or more remarkable picture
than that presented by this volcano. In the interval between
two eruptions, a crater may either present no luminous ap-
pearance, showing merely open fissures and ascending vapors,
or the scarcely heated soil may be covered by eminences of
Bcorise, that admit of being approached without danger, and
thus present to the geologist the spectacle of the eruption of
burning and fused masses, which fall back on the ledge of the
cone of scoriaj, and whose appearance is regularly announced
by small wholly local earthquakes. Lava sometimes streams
forth from the open fissures and small hollows, without break-
ing through or escaping beyond the sides of the crater. If,
however, it does break through, the newly-opened terrestrial
Btream generally flows in such a quiet and well-defined course,
that the deep valley, which we term the crater, remains acces

232 COSMOS.

sible even during periods of eruption. It is impossible, with-
out an exact representation of the configuration — the normal
type, as it were, of fire-emitting mountains, to form a just idea
of those phenomena which, owing to fantastic descriptions and
an undefined phraseology, have long been comprised under the
head of craters, cones of eruption, and volcanoes. The mar-
ginal ledges of craters vary much less than one would be led
to suppose. A comparison of Saussure's measurements with
my own yields the remarkable result, for instance, that in the
course of forty-nine years (from 1773 to 1822), the elevation
of the northwestern margin of Mount Vesuvius [Rocca del
Palo) may be considered to have remained unchanged.*

Volcanoes which, like the chain of the Andes, lift their sum
mits high above the boundaries of the region of perpetual snow,
present peculiar phenomena. The masses of snow, by their
sudden fusion during eruptions, occasion not only the most fear-
ful inundations and torrents of water, in which smoking scorias
are borne along on thick masses of ice, but they likewise ex-
ercise a constant action, while the volcano is in a state of per
feet repose, by infiltration into the fissures of the trachytic rock.
Cavities which are either on the declivity or at the foot of the
mountain are gradually converted into subterranean reservoirs
of water, which communicate by numerous narrow openings
with mountain streams, as we see exemplified in the highlands
of Quito. The fishes of these rivulets multiply, especially in
the obscurity of the hollows ; and when the shocks of earth-
quakes, which precede all eruptions in the Andes, have vio-
lently shaken the whole mass of the volcano, these subterra-
nean caverns are suddenly opened, and water, fishes, and tufa-
ceous mud are all ejected together. It is through this singular
phenoraenont that the inhabitants of the highlands of Quito
became acquainted with the existence of the little cyclopia
fishes, termed by them the prehadilla. On the night betwecD
the 19th and 20th of June, 1698, when the summit of Car*
guairazo, a mountain 19,720 feet in height, fell in, leaving
only two huge masses of rock remaining of the ledge of the
crater, a space of nearly thirty-two square miles was over-
flowed and devastated by streams of liquid tufa and argilla-
ceous mud (lodazales), containing large quantities of dead fish.

* See the ground-work of my measurements compared with those of
Saussure and Lord Minto, in the Abhandlungen der Akademie der Wi*9.
zu Berlin for the years 1822 and 1823.

t Pimelodes cyclopum. See Humboldt, Recueil d^Ohservatiovf ^t
Zoologie et d'' Anatomie Comparie, t. i., p. 21-25.

VOLCANOES. 233

In like manner, the putrid fever, which raged seven yeais pre-
viously in the mountain town of Ibarra, north of Quito, was
ascribed to the ejection of fish from the volcano of Imbaburu.*

Water and mud, which flow not from the crater itself, but
tirom the hollows in the trachytic mass of the mountain, can
not, strictly speaking, be classed among volcanic phenomena.
They are only indirectly connected with the volcanic activity
of the mountain, resembling, in that respect, the singular me-
teorological process which I have designated in my earlier writ-
ings by the term of volcanic storm. The hot stream which
rises from the crater during the eruption, and spreads itself in
the atmosphere, condenses into a cloud, and surrounds the col-
umn of fire and cinders which rises to an altitude of many
thousand feet. The sudden condensation of the vapors, and.
as Gay-Lussac has shown, the formation of a cloud of enor-
mous extent, increase the electric tension. Forked lightning
flashes from the column of cinders, and it is then easy to dis-
tinguish (as at the close of the eruption of Mount Vesuvius, in
the latter end of October, 1822) the rolling thunder of the vol-
canic storm from the detonations in the interior of the mount-
ain. The flashes of lightning that darted from the volcanic
cloud of steam, as we learn from Olafsen's report, killed eleven
horses and two men, on the eruption of the volcano of Katla-
gia, in Iceland, on the 17th of October, 1755.

Having thus delineated the structure and dynamic activity
of volcanoes, it now remains tor us to throw a glance at the
differences existing in their material products. The subterra-
nean forces sever old combinations of matter in order to pro-
duce new ones, and they also continue to act upon matter as
long as it is in a state of liquefaction from heat, and capable
of being displaced. The greater or less pressure under which
merely softened or wholly liquid fluids are solidified, appears to
constitute the main difference in the formation of Plutonic and
volcanic rocks. The mineral mass which flows in narrow,
elongated streams from a volcanic opening (an earth-spring),
is called lava. Where many such currents meet and are ar-
rested in their course, they expand in width, filling large ba-
sins, in which they become solidified in superimposed strata.
These few sentences describe the general character of the prod-
ucts of volcanic activity.

* [It would appear, as there is no doubt that these fishes proceed from
the mountain itself, that there must be large lakes in the interior, which
in ordinary seasons are out of the immediate influence of the volcanio
action See Daubeney, op. cit., p. 488, 497.]--rr.

234 COSMOS.

Rocks which are .nerely broken through by the volcanic ac-
tion are often inclosed in the igneous products. Thus I have
found angular fragments of feldspathic syenite imbedded in the
black augitic lava of the volcano of JoruUo, in Mexico ; but
the masses of dolomite, and granular limestone, which contain
magnificent clusters of crystalline fossils (vesuvian and garnets,
covered with mejonite, nepheline, and sodalite), are not the
ejected products of Vesuvius, these belonging rather to very
generally distributed formations, viz., strata of tufa, which arc
more ancient than the elevation of the Somma and of Vesu
vius, and are probably the products of a deep-seated and con
cealed submarine volcanic action.* We find five metals among
the products of existing volcanoes, iron, copper, lead, arsenic,
and selenium, discovered by Stromeyer in the crater of Volca-
no, t The vapors that rise from the fumarolles cause the sub-
limation of the chlorids of iron, copper, lead, and ammonium ;
iron glancel and chlorid of sodium (the latter often in large
quantities) fill the cavities of recent lava streams and the fis-
sures of the margin of the crater.

The mineral composition of lava differs according to the na-
ture of the crystalline rock of which the volcano is formed, the
height of the point where the eruption occurs, whether at the
foot of the mountain or in the neighborhood of the crater, and
the condition of temperature of the interior. Vitreous volcanic
formations, obsidian, pearl-stone, and pumice, are entirely want-
ing in some volcanoes, while in the case of others they only
proceed from the crater, or, at any rate, from very considera-
ble heights. These important and involved relations can only
be explained by very accurate crystallographic and chemical
investigations. My fellow-traveler in Siberia, Gustav Rose,
and subsequently Hermann Abich, have already been able,
by their fortunate and ingenious researches, to throw much
light on the structural relations of the various kinds of vol-
canic rocks.

* Leop. von Buch, in Poggend., Annalen, bd. xxxvii., s. 179.

\ [The little island of Volcano is separated from Lipari by a narrow
channel. It aj.pears to have exhibited strong signs of volcanic activ"
ity long before vhe Christian era, and stiU emits gaseous exhalations.
Stromeyer detected the presence of selenium in a mixture of sal ammo-
niac and sulphur. Another product, supposed to be peculiar to this
volcano, is boracic acid, wlaich lines the sides of the cavities in beauti-
ful v^hite silky crystals. Daubeney, op. cit,, p. 257.] — Tr.

X Regarding the chemical origin of iron glance in volcanic masses, see
Mitscherlich, in Poggend., Annalen, bd. xv., s. 630 ; and on the libera
lion of hydrochloric acid in the crater, see Gay-Lussac, in the Annate^
in Chimique et de Physique, t. xxii., p. 423.

VOLCANOES, 235

Tlie greater part of the ascending vapor is mere steam.
When condensed, this forms springs, as in Pantellaria,^ where
they are used by the goatherds of the island. On the morn-
ing of the 26th of October, 1822, a current was seen to flow
from a lateral fissure of the crater of Vesuvius, and was long
supposed to have been boiling water ; it was, however, shown,
by Monticelli's accurate investigations, to consist of dry ashes,
which fell like sand, and of lava pulverized by friction. The
ashes, which sometimes darken the air for hours and days to-
gether, and produce great injury to the vineyards and olive
groves by adhering to the leaves, indicate by their columnar
ascent, impelled by vapors, the termination of every great
earthquake. This is the magnificent phenomenon which
Pliny the younger, in his celebrated letter to Cornelius Tacitus,
compares, in the case of Vesuvius, to the form of a lofty and
thickly-branched and foliaceous pine. That which is de-
scribed as flames in the eruption of scoria3, and the radiance
of the glowing red clouds that hover over the crater, can not
be ascribed to the effect of hydrogen gas in a state of combus-
tion. They are rather reflections of light which issue from
molten masses, projected high in the air, ano also reflections
from the burning depths, whence the glowing vapors ascend.
We will not, however, attempt to decide the nature of the
flames, which are occasionally seen now, as in the time of
Strabo, to rise from the deep sea during the activity of littoral^
volcanoes, or shortly before the elevation of a volcanic island.

When the questions are asked, what is it that burns in the
volcano ? what excites the heat, fuses together earths and
metals, and imparts to lava currents of thick layers a degree
of heat that lasts for many years ?t it is necessarily implied
that volcanoes must be connected with the existence of sub-
stances capable of maintaining combustion, like the beds of
coal in subterranean fires. According to the difiierent phases
of chemical science, bitumen, pyrites, the moist admixture of
finely-pulverized sulphur and iron, pyrophoric substances, and
the metals of the alkalies and earths, have in turn been desig-
nated as the cause of intensely active volcanic phenomena.
The great chemist. Sir Humphrey Davy, to whom we are in-
debted for the knowledge of the most combustible metallic

* [Steam issues from many parts of this insular mountain, and sev-
eral hot springs gush forth from it, which form together a lake 6000 feet
in circumference. Daubeney, op. cit.] — Tr.

t See the beautiful experiments on the cooliag oiT masses of rock, in
Uischof's Wdrmrlehre, s. 384, 443, 500-512.

S36 COSMOS.

substances, has himself renounced his bold chenical hypothcsu
in his last work ( Consolation in Travel, and last Days of a
Philosophei-) — a work which can not fail to excite in the
reader a feeling of the deepest melancholy. The great mean
density of the earth (5*44), when compared with the specific
weight of potassium (0-865), of sodium (0*972), or of the
metals of the earths (12), and the absence of hydrogen gas in
the gaseous emanations from the fissures of craters, and from
still warm streams of lava, besides many chemical considera-
tions, stand in opposition with the earlier conjectures of Davy
and Ampere.* If hydrogen were evolved from erupted lava,
how great must be the quantity of the gas disengaged, when,
the seat of the volcanic activity being very low, as in the case
of the remarkable eruption at the foot of the Skaptar Jokul in
Iceland (from the 11th of June to the 3d of August, 1783,
described by Mackenzie and Soemund Magnussen), a space of
many square miles was covered by streams of lava, accumu-
lated to the thickness of several hundred feet I Similar diffi-
culties are opposed to the assumption of the penetration of the
atmospheric air into the crater, or, as it is figuratively ex-
pressed, the inhalatio7i of the earth, when we have regard to
the small quantity of nitrogen emitted. So general, deep-
seated, and far-propagated an activity as that of volcanoes,
can not assuredly have its source in chemical affinity, or in
the mere contact of individual or merely locally distributed
substances. Modern geognosyf rather seeks the cause of this
activity in the increased temperature with the increase of
depth at all degrees of latitude, in that powerful internal heat
which our planet owes to its first solidification, its formation
in the regions of space, and to the spherical contraction of

* See Berzelius and Wohler, in Poggend., Annalen, bd. i., s. 221, and
bd. xi., 8. 146 ; Gay-Lussac, in the Annales de Chimie, t. x., xii., p. 422 ;
and Bischof 's Reasons against the Chemical Theory of Volcanoes, in the
English edition of his Warmelehre, p. 297-309.

t [On the various theories that liave been advanced in explanation of
volcanic action, see Daubeney On Volcanoes, a work to which we have
made continual reference during the preceding pages, as it constitutes
the most recent and perfect compendium of all the important facts re-
lating to this subject, and is peculiarly adapted to serve as a source of
reference to the Cosmos, since the learned author in many instances en-
ters into a full exposition of the views advanced by Baron Humboldt.
The appendix contains several valuable notes with reference to the
most recent works that have appeared on the Continent, on subjects re-
lating to volcanoes; among others, an interesting notice of Professor
Bischof's views " on the origin of the carbonic acid discharged trora
volcanoes," as enounced in his recently published work, Lekrbuch def
Chemischen und Physikalischen Oeologie.'] — Tr.

VOLCANOES. 237

matter revolving elliptisally in a gaseous condition. We have
thus mere conjecture and supposition side by side w^ith cer-
tain knowledge. A philosophical study of nature strives ever
to elevate itself above the narrow requirements of mere natural
description, and does not consist, as we have already remark-
ed, in the mere accumulation of isolated facts. The inquir-
ing and active spirit of man must be suffered to pass from the
present to the past, to conjecture all that can not yet be known
with certainty, and still to dwell with pleasure on the ancient
myths of geognosy which are presented to us under so many
various forms. If we consider volcanoes as irregular inter-
mittent springs, emitting a fluid mixture of oxydized metals,'
alkalies, and earths, flowing gently and calmy wherever they
And a passage, or being upheaved by the powerful expansive
force oi" vapors, we are involuntarily led to remember the geog-
uostic visions of Plato, according to which hot springs, as well
as all volcanic igneous streams, were eruptions that might be
traced back to one generally distributed subterranean cause,
Pyriplilegethon. *

* According to Plato's geognostic views, as developed in the Phcedo,
Pyriphlegethon plays much the same part in relation to the activity of
volcanoes that we now ascribe to the augmentation of heat as we de-
scend from the earth's surface, and to the fused condition of its internal
strata. {Phcedo, ed. Ast, p. 6Q3 and 607; Annot., p. 808 and 817.)
" Within the earth, and all around it, are larger and smaller caverns.
Water flows there in abundance ; also much tire and large streams of
fire, and streams of moist mud (some purer and others more filthy),
like those in Sicily, consisting of mud and fire, preceding the great erup-
tion. These streams fill all places that fall in the way of their course.
Pyriphlegethon flows forth into an extensive district burning with a
fierce fire, where it forms a lake larger than our sea, boiling with water
and mud. From thence it moves in circles round the earth, turbid and
muddy." This stream of molten earth and mud is so much the general
cause of volcanic phenomena, that Plato expressly adds, "thus is Pyri-
phlegethon constituted, from which also the streams of fire (oi ^vaKeg),
wherever they reach the earth (oktj av Tvx(->(yL ttj^ y^f), inflate such
parts (detached fragments)." Volcanic scoriae and lava streams are
therefore portions of Pyriphlegethon itself, portions of the subterranean
molten and ever-undulating mass. That ol ^vaKeg are lava streams, and
not, as Schneider, Passow, and Schleiermacher will have it, " fire-vom-
iting mountains," is clear enough from many passages, some of which
have been collected by Ukert {Geogr. der Qriechen und Romer, th. ii.,
B. 200) ; {)va^ is the volcanic phenomenon in reference to its most strik-
ing characteristic, the lava stream. Hence the expression, the f)vaKe^
of iEtna. Aristot., Mirab. Arise, t. ii., p. 833 ; sect. 38, Bekker ;
Thucyd., iii., 116; Theophrast., DeLap., 22, p. 427, Schneider; Diod.,
v., 6, and xiv., 59, where are the remarkable words, " Many places
near the sea, in the neighborhood of iEtna, were leveled to the ground..
vvd Tov Kaloviiivov ^vckoc^' Strabo, vi., p. 269; xiii., p. 268, and

238 COSMOS.

The different volcanoes over the earth's surface, when they
are considered independently of all climatic differences, are
acutely and characteristically classified as central and lineal
volcanoes. Under the first name are comprised those which
constitute the central point of many active mouths of erup"
tion, distributed almost regularly in all directions ; under the
second, those lying at some little distance from one another,
forming, as it were, chimneys or vents along an extended
fissure. Linear volcanoes again admit of further subdivision,
namely, those which rise like separate conical islands from the
bottom of the sea, being generally parallel with a chain of
primitive mountains, whose foot they appear to indicate, and
those volcanic chains w^hich are elevated on the highest ridges
of these mountain chains, of which they form the summits.*
The Peak of Teneriffe, for instance, is a central volcano, being
the central point of the volcanic group to which the eruption
of Palma and Lancerote may be referred. The long, rampart-
Hke chain of the Andes, which is sometimes single, and some-
times divided into two or three parallel branches, connected
by various transverse ridges, presents, from the south of Chili
to the northwest coast of America, one of the grandest in-
stances of a continental volcanic chain. The proximity of

where there is a notice of the celebrated burning mud of the Lelantine
plains, in Euboea, i., p. 58, Casaub. ; and Appian, De Bello Civili, v.,
114. The blame which Aristotle throws on the geognostical fantasies
of the Phaedo {Meteor., ii., 2, 19) is especially applied to the sources of
the rivers flowing over the earth's surface. The distinct statement of
Plato, that " in Sicily eruptions of wet mud precede the glowing (lava)
stream," is very remarkable. Observations on MXxm could not have led
to such a statement, unless pumice and ashes, formed into a mud-like
mass by admixture with melted snow and water, during the volcano-
electric storm in the crater of eruption, were mistaken for ejected mud.
It is more probable that Plato's streams of moist mud (yypov TrrjTiov
iroTaaoi) originated in a faint recollection of the salses (mud volcanoes)
of Agrigentum, which, as I have already mentioned, eject argillaceous
mud with a loud noise. It is much to be regretted, in reference to this
subject, that the work of Theophrastus nepi pvaKOQ tov ev "ZiKeXta, On
the Volcanic Stream in Sicily, to which Diog. Laert., v., 49, refers, has
not come down to us.

* Leopold von Buch, Physikal. Beschreib. der Cayiarischen Inseln, s.
326-407. I doubt if we can agree with the ingenious Charles Darwin
{Geological Observations on Volcanic Islands, 1844, p. 127) in regard-
ing central volcanoes in general as volcanic chains of small extent on
parallel fissures. Friedrich Hoffman believes that in the group of the
Lipari Islands, which he has so admirably described, and m which two
eruption fissures intersect near Panaria, he has :1bund an intermediate
}ink between the two principal modes in which volcanoes appear,
namely, the central volcanoes and volcanic chains of Von Buch (Pog-
gendorf, Annalen der Physik, bd. xxvi., s. 81-88).

S^OLCANOES. 239

active volcanoes is always manifested in the chain of the An-
des by the appearance of certain rocks (as dolerite, melaphyre,
trachyte, andesite, and dioritic porphyry), which divide the so-
called primitive rocks, the transition slates and sandstones, and
the stratified formations. The constant recurrence of this
plienomenon convinced me long since that these sporadic rocks
were the seat of volcanic phenomena, and were connected with
volcanic eruptions. At the foot of the grand Tunguragua.
near Penipe, on the banks of the Rio Puela, I first distinctly
observed mica slate resting on granite, broken through by a
volcanic rock.

In the volcanic chain of the New Continent, the separate
volcanoes are occasionally, when near together, in mutual de-
pendence upon one another ; and it is even seen that the vol-
canic activity for centuries together has moved on in one and
the same direction, as, for instance, from north to south in the
province of Quito.* The focus of the volcanic action lies be-
lo-w the whole of the highlands of this province ; the only
channels of communication with the atmosphere are, howev
er, those mountains which we designate by special names, as
the mountains of Pichincha, Cotopaxi, and Tunguragua, and
which, from their grouping, elevation, and form, constitute the
grandest and most picturesque spectacle to be found in any
volcanic district of an equally limited extent. Experience
shows us, in many instances, that the extremities of such
groups of volcanic chains are connected together by subterra-
nean communications ; and this fact reminds us of the ancient
and true expression made use of by Seneca,! that the igneous
mountain is only the issue of the more deeply-seated volcanic
forces. In the Mexican highlands a mutual dependence is

* Humboldt, Geognost. Beobach,uber die Vulkane des Hochlandes von
Quito, in Poggend., Annul, der Physik, bd. xliv., s. 194.

t Seneca, while he speaks very clearly regarding the problematical
sinking of ^tna, says in his 79th letter, " Though this might happen,
not because the mountain's height is lowered, but because the fires ai-e
weakened, and do not blaze out with their former vehemence ; and for
which reason it is that such vast clouds of smoke are not seen in the
day-time. Yet neither of these seem incredible, for the mountain may
possibly be consumed by being daily devoured, and the fire not be so
large gis formerly, since it is not self-generated here, but is kindled in
the distant bowels of the earth, and there rages, being fed with con-
tinual fuel, not with that of tho mountain, through which it only makea
its passage." The subterranean communication, " by galleries," be-
tween the volcanoes of Sicily, Lipari, Pithecusa (Ischia), and Vesuvius,
"of the last of which we may conjecture that it formerly burned and
presented a fiery circle," seems fully understood by Strabo (lib. i., p
247 and 248). He terms the whole distric " sub-ig>neous."

240 COSMOS.

also observed to exist amonor the volcanic mountains Oriza-
ba, Popocatepetl, JoruUo, and Colima ; and I have shown^
that they all lie in one direction between 18° 59' and 19° 12'
north latitude, and are situated in a transverse fissure running
from sea to sea. The volcano of JoruUo broke forth on the
29th of September, 1759, exactly in this direction, and over
the same transverse fissure, being elevated to a height of 1604
feet above the level of the surrounding plain. The mountaip
only once emitted an eruption of lava, in the same manner as
is recorded of Mount Epomeo in Ischia, in the year 1302
But although Jorullo, which is eighty miles from any active
volcano, is in the strict sense of the word a new mountain, it
must not be compared with Monte Nuovo, near Puzzuolo,
which first appeared on the 19th of September, 1538, and is
rather to be classed among craters of elevation. I believe
that I have furnished a more natural explanation of the erup-
tion of the Mexican volcano, in cbmparing its appearance to
the elevation of the Hill of Methone, now Methana, in the
peninsula of TroBzene. The description given by Strabo and
Pausanias of this elevation, led one of the Roman poets, most
celebrated for his richness of fancy, to develop views which
agree in a remarkable manner with the theory of modern
geognosy. " Near Troezene is a tumulus, steep and devoid of
trees, once a plain, now a mountain. The vapors inclosed in
dark caverns in vain seek a passage by which they may escape.
The heaving earth, inflated by the force of the compressed
vapors, expands like a bladder filled with air, or like a goat-
skin. The ground has remained thus inflated, and the high
projecting eminence has been solidified by time into a naked
rock." Thus picturesquely, and, as analogous phenomena
justify us in believing, thus truly has Ovid described that
great natural phenomenon which occurred 282 years before
our era, and, consequently, 45 years before the volcanic sepa-
ration of Thera (Santorino) and Therasia, between Troezene
and Epidaurus, on the same spot where R-ussegger has found
veins of trachyte.t

* Humboldt, Essai Politique sur la Nouv. Espagne, t. ii., p. 173-175
t Ovid's description of the eruption of Methone (Meiam., xv., p. 296
30(5) :

" Near Troezene stands a hill, exposed in air
To winter winds, of leafy shadows bare :
This once was level ground; but (strange to tell)
Th' included vapors, that in caverns dwell,
Laboring with colic pangs, and close confined,
In vain sought issue for the rumbling wind :
Yet still they heaved for vent, and heaving stil!
Enlarged the concave and shot up the bill.

VOLCANOES. 241

Santoniio is the most important of all ;ke isla7ids of erup-
tion belonging to volcanic chains.* " It combines within it

As breath extends a bladder, or the skins
Of goats are blown t' inclose the hoarded wines ;
The mountain yet retains a mountain's face,
And gathered rubbish heads the hollow space."

Dryden's Transladoiu

This description of a dome-shaped elevation on the continent is of
^reat importance in a geognostical point of view, and coincides to a re-
markable degree with Aristotle's account (^Meteor., ii., 8, 17-19) of the
upheaval of islands of eruption : " The heaving of the earth does not
cease till the wind (aVCjUOf) which occasions the shocks has made iti
escape into the crust of the earth. It is not long ago since this actually
happened at Heraclea in Pontus, and a similar event formerly occurred
at Hiera, one of the iEolian Islands. A portion of the earth swelled up,
and with loud noise rose into the form of a hill, till the mighty urging
blast (nvevfia) found an outlet, and ejected sparks and ashes which
covered the neighborhood of Lipari, and even extended to several
Italian cities." In this description, the vesicular distension of the
earth's crust (a stage at which many trachytic mountains have remained)
is very well distinguished from the eruption itself. Strabo, lib. i., p.
59 (Casaubon), likewise describes the phenomenon as it occurred at
Methone : near the town, in the Bay of Hermione, there arose a flaming
eruption ; a fiery mountain, seven (?) stadia in height, was then thrown
up, which during the day was inaccessible from its heat and sulphure-
ous stench, but at night evolved an agreeable odor (?), and was so hot
that the sea boiled for a distance of five stadia, and was turbid for full
twenty stadia, and also was filled with detached masses of z-ock. Re-
garding the present mineralogical character of the peninsula of Methana,
see Fiedler, Reise durch Griechenland, th. i., s. 257-263.

* [I am indebted to the kindness of Professor E. Forbes for the fol
lowing interesting account of the island of Santorino, and the adjacent
islands of Neokaimeni and Micirokaimeui. *' The aspect of the bay is
that of a great crater filled with water, Thera and Therasia forming its
walls, and the other islands being after-productions in its center, VV^/
sounded with 250 fathoms of line in the middle of the bay, between
Therasia and the main islands, but got no bottom. Both these islands
appear to be similarly formed of successive strata of volcanic ashes,
which, being of the most vivid and variegated colors, present a striking
contrast to the black and cindery aspect of the central isles. Neokai-
meni, the last-formed island, is a great heap of obsidian and scoriae.
So, also, is the greater mass, Microkaimeni, which rises up in a conical
form, and has a cavity or crater. On one side of this island, however,
a section is exposed, and cliffs of fine pumiceous ash appear stratified
in the greater islands. In the main island, the volcanic strata abut
against the limestone mass of Mount St. Elias in such a way as to lead
to the inference that they were deposited in a sea bottom in which the
present mountain rose as a submarine mass of rock. The people at
Santorino assured us that subterranean noises are not unfrequently
heard, especially during calms and south winds, when they say the
water of parts of the bay becomes the color of sulphur. My 'own im-
pression is, that this group of islands constitutes a crater of elevation,
of which the outer ones are the remains of the walls, while the central
group are of later origin, and consist partly of upheaved sea bottoma
Vol I— L

242 COSMOS.

self the history of all islands of elevation. For upward of
2000 years, as far as history and tiadition certify, it would
appear as if nature were striving to form a volcano in the
midst of the crater of elevation."* Similar insular eleva-
tions, and almost always at regular intervals of 80 or 90
yearSjt have been manifested in the island of St. Michael, in
the Azores ; but in this case the bottom of the sea has not
been elevated at exactly the same parts. $ The island which
Captain Tillard named Sabrina, appeared unfortunately at
a time (the 30th of January, 1811) when the political rela-
tions of the maritime nations of Western Europe prevented
that attention being bestowed upon the subject by scientific
institutions which was afterward directed to the sudden ap-
pearance (the 2d of July, 1831), and the speedy destruction of
the igneous island of Ferdinandea in the Sicilian Sea, between
the limestone shores of Sciacca and the purely volcanic island
of Pantellaria.§

and partly of erupted matter — erupted, however, beneath the surface
of the water."]— Tr.

* Leop. von Buch, Physik. Beschr. der Canar. Inseln, s. 356-358,
and particularly the French translation of this excellent work, p. 402 ;
and his memoir in Poggendorf's Annalen, bd. xxxviii., s. 183. A sub-
marine island has quite recently made its appearance within the crater
of Santorino. In 1810 it was still fifteen fathoms below the surface of
the sea, but in 1830 it had risen to within three or four. It rises steeply,
like a great cone, from the bottom of the sea, and the continuous ac
tivity of the submarine crater is obvious from the circumstance that sul
phurous acid vapors are mixed with the sea w^ater, in the eastern bay
of Neokaimeni, in the same manner as at Vromolimni, near Methana.
Coppered ships lie at anchor in the bay in order to get their bottoms
cleaned and polished by this natural (volcanic) process. (Virlet,in the
Bulletin de la SociiU Giologique de France, t. iii., p. 109, and Fiedler,
Reise durch Griechenland, th. ii., s. 469 and 584.)

t Appearance of a new island near St. Miguel, one of the Azores, 11th
of June, 1638, 31st of December, 1719, 13th of June, 1811.

t [My esteemed friend, Dr. Webster, professor of Chemistry and
Mineralogy at Harvard College, Cambridge, Massachusetts, U. S., in
his Description of the Island of St. Michael, ^c, Boston, 1822, gives an
interesting account of the sudden appearance of the island named Sa-
brina, which was about a mile in circumference, and two or three
hundred feet above the level of the ocean. After continuing for some
weeks, it sank into the sea. Dr. Webster describes the whole of the
island of St. Michael as volcanic, and containing a number of conical
hills of trachyte, several of which have craters, and appear at some
former time to have been the openings of volcanoes. The hot springs
which abound in the island are impregnated with sulphureted hydro-
gen and carbonic acid gases, appearing to attest the existence of vol
canic action.] — Tr.

^ $ Prevost,in the Bulletin de la SociStS Giologique, t. iii., p. 3«; Fried
rich Hoffman, Hinterlassene Werhe. bd. ii.. s. 451-456.

VOLCANOES. 243

The geographical distribution of the volcanoes which have
been in a state of activity during historical times, the great
number of insular and littoral volcanic mountains, and the oc-
casional, although ephemeral, eruptions in the bottom of the
sea, early led to the belief that volcanic activity was connect-
ed with the neighborhood of the sea, and was dependent upon
it for its continuance. " For many hundred years," says Jus-
tinian, or rather Trogus Pompeius, whom he follows,* " ^Etna
and the ^olian Islands have been burning, and how could
this have continued so long if the fire had not been fed by the

* " Accedunt viciiii et perpetui ^Etnae montis ignes et insularum
^olidurn, veluti ipsis undis alatur incendiura ; neque enim aliter durare
tot seculis taxitus ignis potuisset, nisi humoris nutrimentis aleretur."
(Justin, Hist. Philipp., iv., i.) The volcanic theory with which the
physical description of Sicily here begins is extremely intricate. Deep
strata of sulphur and resin ; a very thin soil full of cavities and easily
fissured ; vialeut motion of the waves of the sea, which, as they strike
together, draw down the air (the wind) for the maintenance of the fire :
such are the elements of the theory of Trogus. Since he seems from
Pliny (xi., 52) to have been a physiognomist, we may presume that nia
numerous lost works were not confined to history alone. The opinion
that air is forced into the inteiior of the earth, there to act on the vol-
canic furnaces, was connected by the ancients with the supposed influ-
ence of winds from different quarters on the intensity of the fires burn-
ing in ^tna, Hiei'a, and Stromboli. (See the remarkable passage in
Strabo, lib. vi., p. 275 and 276.) The mountain island of Stromboli
(Strongyle) was regarded, therefore, as the dwelling-place of iEolus,
" the regulator of the winds," in consequence of the sailors foretelling
the weather from the activity of the volcanic eruptions of this island.
The connection between the eruption of a small volcano with the state
of the barometer and the direction of the wind is still generally recog-
nized (Leop. von Buch, Descr. Phys. des lies Canaries, p. 334 ; HotF-
mann, in Poggend., Annalen, bd. xxvi., s. viii.), although our present
knowledge of volcanic plienomena, and the slight changes of atmos-
pheric pressure accompanying our winds, do not enable us to offer any
satisfactory explanation of the fact. Bembo, who during his youth was
brought up in Sicily by Greek refugees, gave an agreeable narrative of
his wanderings, and in his ^Ina Dialogus (written in the middle of
the sixteenth century) advances the theory of the penetration of sea
water to the very center of the volcanic action, and of the necessity of
the proximity of the sea to active volcanoes. In ascending ^Etna the
following question was proposed : " Bxplana potius nobis quae petimus,
ea incendia unde oriantur et orta quomodo. perdurent. In omni tellure
uuspiam majores fistulae aut meatus ampliores sunt quam in locis, quae
vel mari vicina sunt, vel a mari protinus alluuntur : mare erodit Ula
facillime pergitque in viscera terrte. Itaque cum in aliena regna sibi
viam faciat, ventis etiam facit; ex quo fit, ut loca quaeque maritima
raaxime terrae raotibus subjecta siut, parum mediterranea. Habes
quura in sulfuris venas venti furentes inciderint, unde incendia oriantur
iEtnae tute. Vides, quae mare in radicibus habeat, quae sulfurea sit,
qute cavernosa, quas a mari aliquando perforata ventos admiserit sestU'
BUtas, per quos idonea flammfe materies incenderetur."

244 C0SM03.

neighboring sea ?"* In order to explain the necessity of the
vicinity of the sea, recourse has been had, even in modern
times, to the hypothesis of the penetration of sea w^ater into
the foci of volcanic agency, that is to say, into deep-seated
terrestrial strata. When I collect together all the facts that
may be derived from my own observation and the laborious
researches of others, it appears to me that every thing in this
involved investigation depends upon the questions whether the
great quantity of aqueous vapors, which are unquestionably
exhaled from volcanoes even when in a state of rest, be de-
rived from sea water impregnated with salt, or rather, perhaps,
with fresh meteoric water ; or whether the expansive force of
the vapors (which, at a depth of nearly 94,000 feet, is equal
to 2800 atmospheres) would be able at different depths to
counterbalance the hydrostatic pressure of the sea, and thus
afford them, under certain conditions, a free access to the
focus ;t or whether the formation of metallic chlorids, the
presence of chlorid of sodium in the fissures of the crater, and
the frequent mixture of hydrochloric acid with the aqueous
vapors, necessarily imply access of sea water ; or, finally,
whether the repose of volcanoes' (either when temporary, or
permanent and complete) depends upon the closure of the
channels by which the sea or meteoric water was conveyed,
or whether the absence of flames and of exhalations of hydrogen
(and sulphureted hydrogen gas seems more characteristic of
Bolfataras than of active volcanoes) is not directly at variance

* [Although extinct volcanoes seem by no means confined to the
neighborhood of the present seas, being often scattered over the most
inland portions of our existing continents, yet it will appear that, at the
time at which they were in an active state, the greater part were in the
neighborhood either of the sea, or of the extensive salt or fresh water
lakes, which existed at that period over much of what is now dry land.
This may be seen either by referring to Dr. Boue's map of Europe, or
to that published by Mr. Lyell in the recent edition of his Principles of
Geology (1847), from both of which it will become apparent that, at a
comparatively recent epoch, those parts of France, of Germany, of
Hungary, and of Italy, which afford evidences of volcanic action now
extinct, were covered by the ocean. Daubeney On Volcanoes, p. 605.]
— Tr.

t Compare Gay-Lussac, Sur let Volcans, in the Annales de Chiinie,
t. xxii., p. 427, and Bischof, Wdrmelehre, s. 272. The eruptions of
smoke and steam which have at difierent periods been seen in Lance
rote, Iceland, and the Kurile Islands, during the eruption of the neigh
boring volcanoes, afford indications of the reaction of volcanic foci
through tense columns of water ; that is to say, these phenomena oc
cur when the expansive force of the vapor exceeds the hydrostatic
pressure.

VOLCANOES. 245

with the hypothesis of the decomposition of great masses of
water ?^

The discussion of these important physical questions does
not come within the scope of a work of this nature ; hut, while
we are considering these phenomena, we would enter somewhat
more into the question of the geographical distrihution of still
active volcanoes. We find, for instance, that in the New Worldj
three, viz., JoruUo, Popocatepetl, and the volcano of De la
Fragua, are situated at the respective distances of 80, 132,
and 196 miles from the sea-coast, while in Central Asia, as
Abel Remusatt first made known to geognosists, the Thian-
schan (Celestial Mountains), in which are situated the lava-
emitting mountain of Pe-schan, the solfatara of Urumtsi, and
the still active igneous mountain (Ho-tscheu) of Turfan, lie at
an almost equal distance (1480 to 1528 miles) from the shores
of the Polar Sea and those of the Indian Ocean. Pe-schan is
also fully 1360 miles distant from the Caspian Sea,$ and 172
and 218 miles from the seas of Issikul and Balkasch. It is
a fact worthy of notice, that among the four great parallel
mountain chains which traverse the Asiatic continent from
east to west, the Altai, the Thianschan, the- Kuen-lun, and
the Himalaya, it is not the latter chain, which is nearest to
the ocean, but the two inner ranges, the Thianschan and the
Kuen-lun, at the distance of 1600 and 720 miles from the sea,
which have fire-emitting mountains like ^tna and Vesuvius,
and generate ammonia like the volcano of Guatimala. Chi-
nese writers undoubtedly speak of lava streams when they de-
scribe the emissions of smoke and flame, which, issuing from
Pe-schan, devastated a space measuring ten ii§ in the first
and seventh centuries of our era. Burning masses of stone
flowed, according to their description, " like thin melted fat."
The facts that have been enumerated, and to which sufficient
attention has not been bestowed, render it probable that the
vicinity of the sea, and the penetration of sea water to the foci
of volcanoes, are not absolutely necessary to the eruption of

* [See Daubeney On Volcanoes, Part iii., ch. xxxvi., xxxviii., xxxix.J
— Tr.

t Abel Remusat, Lettre a M. Cordier, in the Annales de Chimie, t. v.,
p. 137.

t Humboldt, Asie Centrale, t. ii., p. 30-33, 38-52, 70-80, and 426-428.
The existence of active volcanoes in Kordofan, 540 miles from the Red
Sea, lias been recently contradicted by Riippell, Reisen in Nubien, 1829,
8. 151.

$ [A /« is a Chinese measurement, equal to about one thirtieth of a

246 COSMOS.

subterranean fire, and that littoral situations only favor the
eruption by forming the margin of a deep sea basin, which,
covered by strata of water, and lying many thousand feet lower
than the interior continent, can offer but an inconsiderable
degree of resistance.

The present active volcanoes, which communicate by per-
manent craters simultaneously with the interior of the earth
and with the atmosphere, must have been formed at a subse-
quent period, when the upper chalk strata and all the tertiary
formations were already present : this is shown to be the fact
by the trachytic and basaltic eruptions which frequently form
the walls of the crater of elevation. Melaphyres extend to the
middle tertiary formations, but are found already in the Jura
limestone, where they break through the variegated sandstone.*
We must not confound the earlier outpourings of granite, quartz-
ose porphyry, and euphotide from temporary fissures in the old
transition rocks with the present active volcanic craters.

The extinction of volcanic activity is either only partial —
m which case the subterranean fire seeks another passage of
escape in the same mountain chain — or it is total, as in Au-
vergne. More recent examples are recorded in historical times,
of the total extinction of the volcano of Mosychlos,t on the
island sacred to HephsBstos (Vulcan), whose " high whirling
flames" were known to Sophocles ; and of the volcano of Me-
dina, which, according to Burckhardt, still continued to pour
out a stream of lava on the 2d of November, 1276. Every
stage of volcanic activity, from its first origin to its extinction,
is characterized by peculiar products ; first by ignited scoriae,
streams of lava consisting of trachyte, pyroxene, and obsidian,
and by rapilli and tufaceous ashes, accompanied by the devel-

* Dufreuoy et Elie de Beaumont, Explication de la Carte Giologiqtie
de la France, t. i., p. 89.

t Sophocl.,PA.z7oc^., V. 971 and 972. On the supposed epoch of the
extinction of the Lemnian fire in the time of Alexander, compare Butt-
mann, in the Museum der Alterthumswissenschaft, bd. i., 1807, s. 295 ;
Dureau de la Malle, in Malte-Brun, Annales des Voyages, t. ix., 1809,
p. 5 ; Ukert, in Bevtuch, Geogr. Epkemeriden, bd. xxxix., 1812, s. 361 ;
Rhode, Res Lemnicce, 1829, p. 8 ; and Walter, Ueber Abnahme der Vul-
lean. Thaiigkeit in HistoriscJien Zeiten, 1844, 8 24. The chart of Lem-
nos, constructed by Choiseul, makes it extremely probable that the ex-
tinct crater of Mosychlos, and the island of Chryse, the desert habitation
of Philoctetes (Otfried Mliller, Minyer, s. 300), have been long swal-
lowed up by the sea. Reefs and shoals, to the northeast of Lemnos,
Btill indicate the spot where the .^gean Sea once possessed an active
volcano like iEtna, Vesuvius, Stromboli, and Volcano (in the Lipari
Isles).

ROCK^ 247

«
opment of large quantities of pure aqueous vapor ; subsequent-
ly, when the volcano becomes a solfatara, by aqueous vapors
mixed with sulphureted hydrogen and carbonic acid gases ;
and, finally, when it is completely cooled, by exhalations of
carbonic ^cid alone. There is a remarkable class of igneous
mountains which do not eject lava, but merely devastating
streams of hot water,* impregnated with burning sulphur and
rocks reduced to a state of dust (as, for instance, the Galun-
gung in Java) ; but whether these mountains present a normal
condition, or only a certain transitory modification of the vol-
canic process, must remain undecided until they are visited by
geologists possessed of a knowledge of chemistry in its present
condition.

I have endeavored in the above remarks to furnish a gen-
eral description of volcanoes — comprising one of the most im-
portant sections of the history of terrestrial activity — and I
have based my statements partly on my own observations, but
more in their general bearin^ on the results yielded by the la-
bors of my old friend, Leopold von Buch, the greatest geogno-
sist of our own age, and the first who recognized the intimate
connection of volcanic phenomena, and their mutual depend-
ence upon one another, considered with reference to their rela-
tions in space.

Volcanic action, or the reaction of the interior of a planet on
its external crust and surface, was long regarded only as an
isolated phenomenon, and was considered solely with respect
to the disturbing action of the subterranean force ; and it is
only in recent times that — greatly to the advantage of geog-
nostical views based on physical analogies — volcanic forces
have been regarded as forming neio rocks, and transforming
those tJiat already existed. We here arrive at the point to
which I have already alluded, at which a well-grounded study
of the activity of volcanoes, whether igneous or merely such
as emit gaseous exhalations, leads us, on the one hand, to the
mineralogical branch of geognosy (the science of the texture
and the succession of terrestrial strata), and, on the other, to
the science of geographical forms and outlines — the configura-
tion of continents and insular groups elevated above the level

* Compare Reinwardt and Hoffmann, in Poggendorf s Annalen, bd.
xii., s. 607 ; Leop. von Buch, Descr. des lies Canaries, p. 424-426. The
eruptions of argillaceous mud at Carguairazo, when that volcano was
destroyed in 1698, the Lodazales of Igualata, and the Moya of Pelileo
—all on the table-land of Quito — ai =) volcanic phenomena of a similar
nature.

248 ^sMos.

••

of the sea. This extended insight into the co» iction of nat-
ural phenomena is the result of the philosop lioal direction
which has been so generally assumed by the more earnest
study of geognosy. Increased cultivation of science and en-
largement of political views alike tend to unite elentents that
had long been divided.

If, instead of classifying rocks according to ijjeir varieties of
form and superposition into stratified and unstratified, schistose
and compact, normal and abnormal, we investigate those phe-
nomena of formation and transformation which are still going
on before our eyes, we shall find that rocks admit of being ar-
ranged according to four modes of origin.

Rocks of erwptio^i, which have issued from the interior of
the earth either in a state of fusion from volcanic action, oi
in a more or less soft, viscous condition, from Plutonic action.

Sedimentary rocks, which have been precipitated and de-
posited on the earth's surface from a fluid, in which the most
minute particles were either dissolved or held in suspension
constituting the greater part of the secondary (or flotz) and
tertiary groups.

Transformed or metamor]phic rocks* in which the interna]
texture and the mode of stratification have been changed, ei-

* [As the doctrine of mineral nnetamfjrpliism is now exciting very
general attention, we subjoin a few ex{)Ianatory observations by the
celebrated Swiss philosopher, Professor Studer, taken from the Ediiib.
New Philos. Journ., Jan., 1848: " In its widest sense, mineral meta-
morphism means every change of aggregation, structure, or chemical
condition which rocks have undergone subsequently to their deposition
and stratification, or the effects which have been produced by other
forces than gi'avity and cohesion. There fall under this definition, the
discoloration of the surface of black limestone by the loss of carbon ;
the formation of brownish-red crusts on rocks of limestone, sandstone,
many slate stones, serpentine, granite, &c., by the decomposition of iron
pyrites, or magnetic iron, finely disseminated in the mass of the rock ;
the conversion of anhydrite into gypsum, in consequence of the absorp.
tion of water ; the crumbling of many granites and porphyries into
gravel, occasioned by the decomposition of the mica and feldspar. In
'ts more limited sense, the term metamorphic is confined to those
changes of the rock which are produced, not by the effect of the at-
mosphere or of water on the exposed surfaces, but which are produced,,
directly or indirectly, by agencies seated in the interior of the earth.
In many cases the mode of change may be explained by our physical
or chemical theories, and may be viewed as the effect of temperature
or of electro-chemical actions. Adjoining rocks, or connecting com-
munications with the interior of the earth, also distinctly point out the
seat from which the change proceeds. In many other cases the meta-
morphic process itself remains a mystery, and from the nature of the
products alone do we conclude that such a metamorphic action hai
taken place.] — Tr.

ROCKS. 249

ther by contact or proximity with a Plutonic or volcanic en-
dogenous rock of eruption,* or, what is more frequently the
case, by a gaseous sublimation of substancest which accom-
pany certain masses erupted in a hot fluid condition.

Conglomerates; coarse or finely granular sandstones, or
breccias composed of mechanically-divided masses of the three
previous species.

1'hese four modes of formation — ^by the emission of volcanic
masses, as narrow lava streams ; by the action of these masses
on rocks previously hardened ; by mechanical separation or
chemical precipitation from liquids impregnated with carbonic
acid ; and, finally, by the cementation of disintegrated rocks
of heterogeneous nature — are phenomena and formative pro
cesses which must merely be regarded as a faint reflection of
that more energetic activity which must have characterized
the chaotic condition of the earlier world under wholly differ-
ent conditions of pressure and at a higher temperature, not
only in the whole crust of the earth, but likewise in the more

* 111 a plan of the neighborhood of Tezcuco, Totonilco, and Moran
(Atlas Gdographique ei Physique, pi. vii.), which I originally (1803)
intended for a work which I never published, entitled Pasigrqfia Geog'
nostica destinada al uso de los Jovenes del Colegio de Mineria de Mexi-
co, I named (in 1832) the Plutonic and volcanic eruptive rocks endoge-
nous (generated in the interior), and the sedimentary and flotz rocks
exogenous (or generated externally on the surface of the earth). Pasi-
graphically, the former were designated by an arrow directed up-
ward f, and the latter by the same symbol directed downward \.
These signs have at least some advantage over the ascending lines,
which in the older systems represent arbitrarily and ungracefully the
horizontally ranged sedimentary strata, and their penetration through
masses of basalt, porphyry, and syenite. The names proposed in the
pasigraphico-geognostic plan were borrowed ^om De Candolle's nomen
clature, in which endogenous is synonymous with monocotyledonous,
and exogenous with dicotyledonous plants. Mold's more accurate ex-
amination of vegetable tissues has, however, shown that the growth of
monocotyledons from within, and dicotyledons fi'om without, is not
strictly and generally true for vegetable organisms (Link, Elementa
PhilosophicB Botanicce, t. i., 1837, p. 287 ; Endlicher and Unger, Grand-
zUge der Botanik, 1843, s. 89; and Jussieu, Traiti de Botanique, t. i.,
» p. 85). The rocks which I have termed endogenous are characteristic
ally distinguished by Lyell, in his Principles of Geology, 1833, vol. iii,,
p. 374, as " nether-formed" or " hypogene rocks."

t Compare Leop. von Buch, Ueber Dolomit als Gehirgsart, 1823, s.
36 ; and his remarks on the degree of fluidity to be ascribed to Plutonic
rocks at the period of their eruption, as well as on the formation of
gneiss from schist, through the action of granite and of the substancea
upheaved with it, to be found in the Abhandl. der Ahad. der Wissen-
$ch. zu Berlin for the year 1842, s. .58 und 63, and in the Jahrbuch fin
Wissenschaftliche KrMik, 1840, s. lfl.5.

L 2

250 COSMOS.

extended atmosphere, overloaded with vapors. The vast fi*
sures which were formerly open in the soUd crust of the earth
have since been fdled up or closed by the protrusion of eleva-
ted mountain chains, or by the penetration of veins of rocks ot
eruption (granite, porphyry, basalt, and melaphyre) ; and while,
on a superficial area equal to that of Europe, there are now
scarcely more than four volcanoes remaining through which
fire and stones are erupted, the thinner, more fissured, and un-
stable crust of the earth was anciently almost every where
covered by channels of communication between the fused in-
terior and the external atmosphere. Gaseous emanations, ris-
ing from very unequal depths, and therefore conveying sub-
stances differing in their chemical nature, imparted greater
activity to the Plutonic processes of formation and transform-
ation. The sedimentary formations, the deposits of liquid fluids
from (jold and hot springs, which we daily see producing the
travertine strata near Rome, and near Hobart Town in Van
Diemen's Land, afford but a faint idea of the flotz formation.
In our seas, small banks of limestone, almost equal in hardness
at some parts to Carrara marble,* are in the course of forma-
tion, by gradual precipitation, accumulation, and cementation
— processes whose mode of action has not been sufficiently
well investigated. The Sicilian coast, the island of Ascension,
and King George's Sound in Australia, are instances of this
mode of formation. On the coasts of the Antilles, these
formations of the present ocean contain articles of pottery,
and other objects of human industry, and in Guadaloupe even
human skeletons of the Carib tribes. t The negroes of the
French colonies designate these formations by the name of
Maconne-bon-Dieu.t A small oolitic bed, formed in Lan-
cerote, one of Jhe CaTiary Islands, and which, notwithstand-

* Darwin, Volcanic Islands, 1844, p. 49 and 154.

t [In most instances the bones are dispersed ; but a larg&«lab of rock,
xn which a considerable portion of the skeleton of a female is imbedded,
is preserved in the British Museum. The presence of these bones has
been explained by the circumstance of a battle, and the massacre of a
tribe of Gallibis by the Caribs, v/hich took place near the spot in which*
they are found, about 120 years ago ; for, as the bodies of the slain
were interred on the sea-shore, their skeletons may have been subse-
quently covered by sand-drift, which has since consolidated into lime-
stone. Dr. Moultrie, of the Medical College, Charleston, South Caro-
lina, U. S., is, however, of opinion that these bones did not belong to
individuals of the Carib tribe, but of the Peruvian race, or of a tribe
possessing a similar craniological development.] — Tr.

\ Moreau de Jonnes, Hisf. Phys. des Antilles, t. i., p. 136, 138, and
513; Huifiboldt, Relation Hiilori'pie, t. iii., p. 367.

ROCKS. 251

ing its recent formatioii, bears a resemblance to Jura lime-
Btone, has been recognized as a product of the sea and of teni'
pests*

Composite rocks are definite associations of certain oryctog-
nostic, simple minerals, as feldspar, mica, solid silex, augite,
and nepheline. Rocks very similar to these, consisting of the
same elements, but grouped differently, are still formed by
volcanic processes, as in the earlier periods of the world. The
character of rocks, as we have already remarked, is so inde-
pendent of geographical relations of space,! that the geologist
recognizes with surprise, alike to the north or the south of
the equator, in the remotest and most dissimilar zones, the
familiar aspect, and the repetition of even the most minute
characteristics in the periodic stratification of the silurian
strata, and in the effects of contact with augitic masses o^
eruption.

We will now enter more fully into the consideration of the
four modes in which rocks are formed — the four phases of
their formative processes manifested in the stratified and un-
stratified portions of the earth's surface ; thus, in the endog-
enous or erupted rocks^ designated by modern geognosists as
compact and abnormal rocks, we may enumerate the follow-
ing principal groups as immediate products of terrestrial ac-
tivity :

1 . Granite and syenite of very different respective ages ;
the granite is frequently the more recent,f traversing the sy-
enite in veins, and being, in that case, the active upheaving
agent. " Where the granite occurs in large, insulated masses
of a faintly-arched, ellipsoidal form, it is covered by a crust or
shell cleft into blocks, instances of which are met with alike
in the Hartz district, in Mysore, and in Lower Peru. This
sea of rocks probably owes its origin to a contraction of the
surface of the granite, owing to the great expansion that ac-
companied its first upheaval."^

Both in Northern Asia,|l on the charming and romantic
shores of the Lake of Kolivan, on the northwest declivity of

* Near Teguiza. Leop. von Buch, Canarische Inseln, s. 301-

t Leop. von Buch, op. cit., p. 9.

t Bernhard Cotta, Geognosie, 1839, 8. 273.

§ Leop. von Buch, Ueber Granit und Gneiss, in the Abhandl. der Berl.
Akad. for the year 1842, s. 60.

II In the projecting mural masses of granite of Lake Kolivan, divided
Into narrow parallel beds, there are numerous crystals of feldspar and
albite, and a few of titanium (Humboldt, Asie Centrale, t. i., p. 295,
Gustav Rose, Reise nat k dem Ural, bd. i., s. 524).

252 COSMOS.

the Altai Mountains, and at Las Trincheras, on the slope ol
the littoral chain of Caraccas,* I have seen granite divided
into ledges, owing probably to a similar contraction, although
the divisions appeared to penetrate far into the interior. Fur-
ther to the south of Lake Kolivan, toward the boundaries of
the Chinese province Hi (between Buchtarminsk and the
River Narym\ the formation of the erupted rock, in which
there is no gneiss, is more remarkable than I ever observed in
any other part of the earth. The granite, which is always
covered with scales and characterized by tabular divisions,
rises in the steppes, either in small hemispherical eminences,
scarcely six or eight feet in height, or like basalt, in mounds,
terminating on either side of their bases in narrow streams.!
At the cataracts of the Orinoco, as well as in the district
of the Fichtelgebirge (Seissen), in Galicia, and between the
Pacific and the highlands of Mexico (on the Papagallo), I
have seen granite in large, flattened spherical masses, which
could be divided, like basalt, into concentric layers. In the
valley of Irtysch, between Buchtarminsk and Ustkamenogorsk,
granite covers transition slate for a spa.ce of four miles,! pen-
etrating into it from above in narrow, variously ramified,
wedge-like veins. I have only instanced these peculiarities
in order to designate the individual character of one of the
most generally diffused erupted rocks. As granite is super-
posed on slate in Siberia and in the Departement de Finisterre
(Isle de Mihau), so it covers the Jura limestone in the mount-
ains of Oisons (Ferments), and syenite, and indirectly also
chalk, in Saxony, near Weinbohla.§ Near Mursinsk, in the ,
Uralian district, granite is of a drusous character, and here
the pores, like the fissures and cavities of recent volcanic prod
ucts, inclose many kinds of magnificent crystals, especially
beryls and topazes.

2. Quartzose porphyry is often found in the relation of
veins to other rocks. The base is generally a finely granular
uiixture of the same elements which occur in the larger im-

♦ Humboldt, Relation Historique, t. ii., p. 99.

t See the sketch of Biri-tau, which I took from the south side, where
the Kirghis tents stood, and which is given in Rose's Reise, bd. i., s. 584.
Ou spheres of granite scaling off concentrically, see ray Relat. Hist., t.
ii., p. 497, and Essai Giogn. sur les Gisement des Roches, p. 78.

X Humboldt, Asie Centrale, t. i., p. 299-311, and the drawings in
Rose's jSezse, bd. i., s. 611, in which we see the curvature in the layers
of granite which Leop. von Buch has pointed out as characteristic.

$ This remarkable superposition was first described by Weiss ii?
Karsteu's Archiv fur Berghau nnd Hutfemoesen, I)d. xvi., 1827. s. 5.

RO LKS. ^ 253

bedded crystals. In granitic porphyry that is very poor in
quartz, the feldspathic base is almost granular and laminated.*

3. Greenstones, Diorite, are granular mixtures of white
albite and blackish-green hornblende, forming dioritic porphy-
ry when the crystals are deposited in a base of denser tissue.
The greenstones, either pure, or inclosing laminae of diallage
(as in the Fichtelgebirge), and passing into serpentine, have
gometimes penetrated, in the form of strata, into the old strat-
ified fissures of green argillaceous slatCj but they more fre-
quently traverse the rocks in veins, or appear as globular
masses of greenstone, similar to domes of basalt and porphyry, t

Hypersthene rock is a granular mixture of labradorite and
hypersthene.

Euphotide and serpentine, containing sometimes crystals
of augite and uralite instead of diallage, are thus neaily allied
to another more frequent, and, I might almost say, more en
ergetic eruptive rock — augitic porphyry 4

Melaphyre, augitic, uralitic, and oligoklastic porphyries
To the last-named species belongs the genuine verd-antique,
so celebrated in the arts.

Basalt, containing olivine and constituents which gelatin-
ize in acids ; phonolithe (porphyritic slate), trachyte, and dol-
erite ; the first of these rocks is only partially, and the second
always, divided into thin laminae, which give them an ap-
pearance of stratification when extended over a large space,
Mesotype and nepheline constitute, according to Girard, an
important part in the composition and internal texture of ba-
salt. The nepheline contained in basalt reminds the geog-
nosist both of the miascite of the Ilmen Mountains in the
Ural,§ which has been confounded with granite, and some-
times contains zirconium, and of the pyroxenic nepheline dis-
covered by Gumprecht near Lobau and Chemnitz.

To the second o;f sedimentary rocks belong the greater part
of the formations which have been comprised under the old

* Dufrenoy et Elie de Beaumont, G^ologie de la France, t. i., p. 130.

t These intercalated beds of diorite play an important part in the
mountain district of Nailau, near Steben, where I was engaged in
mining operations in the last century, and with which the happiest as-
sociations of my early life are connected. Compare Hoffmann, in Pog-
gendorf 's Annalen, bd. xvi., s. 558.

X In the southern and Bashkirian portion of the Ural. Rose, Reise,
bd.ii., 8. 171.

$ G. Rose, Reiie nack dem Ural, bd. ii., s. 47-52. Respecting the
identity of eleolite and nepheline (the latter containing rather the more
lime), see Scheerer, in Poggend., Annalen, bd. xlix., s. 359-381

254 ; COSMOS*

gystematic, but not very correct designation of transitioyi,Jldtz
or secondary, and tertiary formations. If the erupted rocks
had not exercised an elevating, and, owing to the simultane-
ous shock of the earth, a disturbing influence on these sedi-
mentary formations, the surface of our planet would have
consisted of strata arranged in a uniformly horizontal direc-
tion above one another. Deprived of mountain chains, on
whose declivities the gradations of vegetable forms and the
Bcale of the diminishing heat of the atmosphere appear to be
picturesquely reflected — furrowed only here and there by val-
leys of erosion, formed by the force of fresh water moving on
in gentle undulations, or by the accumulation of detritus, re-
sulting from the action of currents of water — continents would
have presented no other appearance from pole to pole than
the dreary uniformity of the llanos of South America or the
Bteppes of Northern Asia. The vault of heaven would every
where have appeared to rest on vast plains, and the stars to
rise as if they emerged from the depths of ocean. Such a
condition of things could not, however, have generally pre-
vailed for any length of time in the earlier periods of the
world, since subterranean forces must have striven in all ep-
ochs to exert a counteracting influence.

Sedimentary strata have been either precipitated or depos-
ited from liquids, according as the materials entering into
their composition are supposed, whether as limestone or ar-
gillaceous slate, to be either chemically dissolved or suspend-
ed and commingled. But earths, when dissolved in fluids
impregnated with carbonic acid, must be regarded as under-
going a mechanical process while they are being precipitated,
deposited, and accumulated into strata. This view is of some
importance with respect to the envelopment of organic bodies
in petrifying calcareous beds. The most ancient sediments
of the transition and secondary formations have probably been
formed from water at a more or less high temperature, and
at a time when the heat of the upper surface of the earth
was still very considerable. Considered in this point of view,
a Plutonic action seems to a certain extent also to have taken
place in the sedimentary strata, especially the more ancient ;
but these strata appear to have been hardened into a schistose
structure, and under great pressure, and not to have been
solidified by copling, like the rocks that have issued from the
interior, as, for instance, granite, porphyry, and basalt. By
degrees, as the waters lost their temperature, and were able
to absorb a copious supply of the carbonic acid gas with which

ROCKS. 255

the atmosphere was overcharged, they became fitted to hold
in solution a larger quantity of lime.

The sedimentary strata, setting aside ail other exogenous,
purely mechanical deposits of sand or detritus, are as follows :

Schist, of the lower and upper transition rock, composing
the Silurian and devonian formations ; from the lower silurian
strata, which were once termed cambrian, to the upper strata
of the old red sandstone or devonian formation, immediately
in contact v/ith the mountain limestone.

Carboniferous deposits :

Limestones imbedded in the transition and carboniferous
formations ; zechstein, muschelkalk, Jura formation and chalk,
also that portion of the tertiary formation which is not includ-
ed in sandstone and conglomerate.

Travertine, fresh- water limestone, and silicious concretions
of hot springs, formations which have not been produced un-
der the pressure of a large body of sea water, but almost ii
immediate contact with the atmosphere, as in shallow marsh-
es and streams.

Infusorial deposits : geognostical phenomena, whose great
importance in proving the influence of organic activity in the
formation of the solid part of the earth's crust was first dis-
covered at a recent period by my highly-gifted friend and fe]-
iow-traveler, Ehrenberg.

If, in this short and superficial view of the mineral con-
stituents of the earth's crust, I do not place immediately after
the simple sedimentary rocks the conglomerates and sandstone
formations which have also been deposited as sedimentary
strata from liquids, and which have been imbedded alternate-
ly with schist and limestone, it is only because they contain,
together with the detritus of eruptive and sedimentary rocks,
also the detritus of gneiss, mica slate, and other metamorphic
masses. The obscure process of this metamorphism, and the
action it produces, must therefore compose the third class of
the fundamental forms of rock.

Endogenous or erupted rocks (granite, porphyry, and mela-
phyre) produce, as I have already frequently remarked, not
only dynamical, shaking, upheaving actions, either vertically
or laterally displacing the strata, but they also occasion chang-
es in their chemical composition as well as in the nature of
their internal structure ; new ro eks being thus formed, as
gneiss, mica slate, and granular limestone (Carrara and Pa-
rian marble). The old silurian or devonian transition schists,
the belemnitic limestone of Tarantaise, and the dull gray cal'

256 COSMOS.

eareous sandstone (Madgno), which contains algse found m
the northern Apennines, often assume a new and more brill-
iant appearance after their metamorphosis, which renders it
difficult to recognize them. The theory of metamorphism
was not established until the individual phases of the change
were followed step by step, and direct chemical experiments
on the difference in the fusion point, in the pressure and time
of cooling, were brought in aid of mere inductive conclusions.
Where the study of chemical combinations is regulated by
leading ideas,* it may be the means of throwing a clear light
on the wide field of geognosy, and over the vast laboratory of
nature in which rocks are continually being formed and mod-
ified by the agency of subterranean forces. The philosophical
inquirer will escape the deception of apparent analogies, and
the danger of being led astray by a narrow view of natural
phenomena, if he constantly bear in view the complicated
conditions which may, by the intensity of their force, have
modified the counteracting effect of those individual substan
ces whose nature is better known to us. Simple bodies have,
no doubt, at all periods, obeyed the same laws of attraction,
and, wherever apparent contradictions present themselves, I
am confident that chemistry will in most cases be able to
trace the cause to some corresponding error in the experiment.
Observations made with extreme accuracy over large tracts
of land, show that erupted rocks have not been produced in an
irregular and unsystematic manner. In parts of the globe most
remote from one another, we often find that granite, basalt, and
diorite have exercised a regular and uniform metamorphic ac-
tion, even in the minutest details, on the strata of argillaceous
slate, dense limestone, and the grains of quartz in sandstones.
As the same endogenous rock manifests almost every where the
same degree of activity, so, on the contrary, different rocks be-
longing to the same class, whether to the endogenous or the
erupted, exhibit great differences in their character. Intense
heat has undoubtedly influenced all these phenomena, but the
degree of fluidity (the more or less perfect mobility of the parti-
cles— their more viscous composition) has varied very consid*
nrably from the granite to the basalt, while at diflerent geo-

* See the admirable researches of Mitscherlich, iu the Abhandl. det
Berl. Akad. for the years 1822 and 1823, s. 25-41 ; and in Poggend.,
Annalen, bd. x., s. 137-152; bd. xi., s. 323-332; bd. xli., s. 213-216
(Gustav Rose, Ueber Bildung des Kalkspaths und Aragr-niis, in Fog
geiyi , Annalen, bd. xli., s, 353-366 ; Haidinger, in the Transaction*
fthe Royal Society of Edinburgh, 1827, p. 148.)

LOCKS *25t

kOgical periods (or metamorphic phases of the earth's crust)
other substances dissolved in vapors have issued from the in-
terior of the earth simultaneously with the eruption of granite,
basalt, greenstone porphyry, and serpentine. This seems a
fitting place again to draw attention to the fact that, accord-
ing to the admirable views of modern geognosy, the meta-
morphism of rocks is not a mere phenomenon of contact, limit-
ed to the effect produced by the apposition of two rocks, since
it comprehends all the generic phenomena that have accom-
panied the appearance of a particular erupted mass. Even
where there is no immediate contact, the proximity of such a
mass gives rise to modifications of solidification, cohesion, gran-
ulation, and crystallization.

All eruptive rocks penetrate, as ramifying veins, either into
the sedimentary strata, or into other equally endogenous mass-
es ; but there is a special importance to be attached to the
difference manifested between Plutonic rocks* (granite, por-
phyry, and serpentine) and those termed volcanic in the strict
sense of the word (as trachyte, basalt, and lava). The rocks
produced by the activity of our present volcanoes appear as
band-like streams, but by the confluence of several of them
they may form an extended basin. Wherever it has been
possible to trace basaltic eruptions, they have generally been
found to terminate in slender threads. Examples of these
narrow openings may be found in three places in Germany :
in the " FJiast^r-kaute,'' at Marksuhl, eight miles from Ei-
senach ; in the blue " Kuppe,'' near Eschwege, on the banks
of the Werra ; and in the Druidical stone on the Hollert road
(Siegen), where the basalt has broken through the variegated
sandstone and gray wacke slate, and has spread itself into cup-
like fungoid enlargements, which are either grouped together
like rows of columns, or are sometimes stratified in thin 1am-
insB. The case is otherwise with granite, syenite, quartzose
porphyry, serpentine, and the whole series of unstratified com-
pact rocks, to which, from a predilection for a mythological
nomenclature, the term Plutonic has been applied. These,
with the exception of occasional veins, were probably not
erupted in a state of fusion, but merely in a softened condi-
tion ; not from narrow fissures, but from long and widely-ex.
tending gorges. They have been protruded, but have not
flowed forth, and are found, not in streams like lava, but in
extended masses. t Some groups of dolerite and trachyte in-

* [Lyell, Principles of Geology, vol, iii., p. 353 and 359.] — Tr

t The description here given of the relations of position under vi^hicb

)15S COSMOS.

dicate a certain degree of basaltic fluidity ; others, which have
been expanded into vast craterless domes, appear to have been
only in a softened condition at the time of their elevation
Other trachytes, like those of the Andes, in which I have fre-
quently perceived a striking analogy with the greenstones and
syenitic porphyries (which are argentiferous, and without
quartz), are deposited in the same manner as granite and
quartzose porphyry.

Experiments on the changes which the texture and chem-
ical constitution of rocks experience from the action of heat,
have shown that volcanic masses* (diorite, augitic porphyry,
basalt, and the lava of ^Etna) yield different products, accord-
ing to the difference of the pressure mider which they have
been fused, and the length of time occupied during their cool-
ing ; thus, where the cooling was rapid, they form a black
glass, having a homogeneous fracture^ and where the cooling
was slow, a stony mass of granular crystalline structure. In
the latter case, the crystals are formed partly in cavities and
partly inclosed in the matrix. The same materials yield the
most dissimilar products, a fact that is of the gi-eatest import
ance in reference to the study of the nature of erupted rocks, and
of the metamorphic action which they occasion. Carbonate of
lime, when fused under great pressure, does not lose its carbonic
acid, but becomes, when cooled, granular limestone ; when
the crystallization has been effected by the dry method, sac-
charoidal marble ; while by the humid method, calcareous
spar and aragonite are produced, the former under a lesser de-
gree of temperature than the latter. f Differences of temper-
granite occurs, expresses the general or leading character of the whole
lormation. But its aspect at some places leads to the belief that it was
occasionally more fluid at the period of its eruption. The description
given by Rose, in his Reise nach dem Ural, bd. i., s. 599, of part of the
Narym chain, near the frontiers of the Chinese territories, as well as the
evidence aflbrded by trachyte, as described by Dufrenoy and Elie de
Beaumont, in their Description Giologique de la France, t. i., p. 70.
Having already spoken in the text of the narrow apertures through
which the basalts have sometimes been effused, I will here notice the
large fissures, which have acted as conducting passages for melaphyres,
which must not be confounded with basalts. See Murchison's inter-
.esting account ( The Silurian System, p. 126) of a fissure 480 feet wide,
through which raelaphyre has been ejected, at the coal-mine at Corn-
brook, Hoar Edge.

* Sir James Hall, in the Edin. Trans., vol. v., p. 43, and vol. vi., p
71; Gregory Watt, in the Phil. Trans, of the Roy. Soc. of London for
1804, Part ii., p. 279 ; Dartigues and Fleurieu de Bellevue, in the Jour'
nal de Physique, t. Ix., p. 456; Bischof, Wdrmelehre, s. 313 und 443.

\ (iiistav Rose, in Poi'send., Annn^~n., 1x1 xlii., s 364.

ROCKS. 259

Rxure likewise modify the direction in which the different par-
ticles arrange themselves in the act of crystallization, and also
afiect the form of the crystal.* Even when a body is not in
a fluid condition, the smallest particles may undergo certain
relations in their various modes of arrangement, which are
manifested by the different action on light. t The phenome-
na presented by devitrification, and by the formation of steel
by cementatron and casting — the transition of the fibrous into
the granular tissue of the iron, from the action of heat,$ and
probably, also, by regular and long-continued concussions —
likewise throw a considerable degree of light on the geological
process of metamorphism. Heat may even simultaneously in-
duce opposite actions in crystalline bodies ; for the admirable
experiments of Mitscherlich have established the fact§ that
calcareous spar, without altering its condition of aggregation,
expands in the direction of one of its axes and contracts in
the other.

If we pass from these general considerations to individual
examples, we find that schist is converted, by the vicinity of
Plutonic erupted rocks, into a bluish-black, glistening roofing
slate. Here the planes of stratification are intersected by an-
other system of divisional stratification, almost at right angles
with the former, II and thus indicating an action subsequent to
the alteration. The penetration of silica causes the argilla-
ceous schist to be traversed by quartz, transforming it, in part,
into whetstone and silicious schist ; the latter sometimes con-
taming carbon, and being then capable of producing galvanic
efiects on the nerves. The highest degree of silicification of
schist is that observed in ribbon jasper, a material highly val-
uable in the arts, IF and which is produced in the Oural Mount-

* Oa the dimorphism of sulphur, see Mitscherlich, Lehrhuch der
Chemie, § 55-63.

t On gypsum as a uniaxal crystal, and on the sulphate of magnesia,
and the oxyds of zinc and nickel, see Mitscherlich, in Poggend., An7ia'
len, bd. xi., s. 328.

X Coste, Versuche am Creusot uber das hruchig werden des Stabeisens.
Elie de Beaumont, Mem. O6ol., t. ii., p. 411.

§ Mitscherlich, Ueber die Ausdehnung der Krystallisirten Korper durch
die Wdrmelehre, in Poggend., Annalen, bd. x., s. 151.

II On the double system of divisional planes, see Elie de Beaumont,
Geologic de la France, p. 41 ; Credner, Geognosie Tkuringens nnd dea
Harzes, s. 40; and Romer, Das Rheinische Uebergangsgebirge, 1844,
B. 5 und 9.

1[ The silica is not merely colored by peroxyd of iron, but is accom-
panied by clay, lime, and potash. Rose, Rcise, bd. ii.. s. 187. On the
tbrn>ation of jafper b) the action of dioritic pojphyry, augite, and by

260 COSMOS.

ains by the contact and eruption of augitic porphyry (at Orsk),
of dioritic porphyry (at Aufschkul), or of a mass of hyper-
sthenic rock conglomerated into spherical masses (at Bogos-
lowsk). At Monte Serrate, in the island of Elba, ac(;ordino
to Frederic Hofiman, and in Tuscany, according to Alexandei
Brongniart, it is formed by contact with euphotide and ser-
pentine.

The contact and Plutonic action of granite have sometimes
made argillaceous schist granular, as was observed by Gustav
Rose and myself in the Altai Mountains (within the fortress
of Buchtarminsk),=* and have transformed it into a mass re-
sembling granite, consisting of a mixture of feldspar and mica,
in which larger laminae of the latter were again imbedded. +
Most geognosists adhere, with Leopold von Buch, to the well-
known hypothesis " that all the gneiss in the silurian strata of
the transition formation, between the Icy Sea and the Gulf of
Finland, has been produced by the metamorphic action oi
granite. $ In the Alps, at St. Gothard, calcareous marl i&
likewise changed from granite into mica slate, and then trans-
formed into gneiss." Similar phenomena of the formation of
gneiss and mica slate through granite present themselves in
the oohtic group of the Tarantaise,^ in which belemnites are

persthene rock, see Rose, bd. ii., s. 169, 187, unci 192. See, also, bd.
i., s. 427, where there is a drawing of the porphyry spheres between
which jasper occurs, in the calcareous gray wacke of Bogoslowsk, being
produced by the Plutonic influence of the augitic rock; bd. ii., s. 545 ;
and likewise Humboldt, Asie Centrale, t. i., p. 486. #

* Rose, Reise nach dem Ural, bd. i., s. 586-588.

t In respect to the volcanic origin of mica, it is important to notice
that ciystals of mica are found in the basalt of the Bohemian Mittelge-
birge, in the lava that in 1822 was ejected from Vesuvius (Monticelli,
Storia del Vesuvio negli Anni 1821 e 1822, $ 99), and in fragments of
argillaceous slate imbedded in scoriaceous basalt at Hohenfela, not far
from Gerolstein, in the Eifel (see Mitscherlich, in Leonhard, Basalt-
Gebilde, s. 244). On the formation of feldspar in argillaceous schist,
through contact with porphyry, occurring between Urval and Poiet
(Forez), see Dufrenoy, in Giol. de la France, t. i., p. 137. It is proba-
bly to a similar contact that certain schists near Paimpol, in Brittany,
with whose appearance I was much struck, while making a geological
pedestrian tour through that interesting country with Professor Kunth,
owe their amygdaloid and cellular character, t. i., p. 234.

X Leopold von Buch, in the Abhandlungen der Akad. der Wisseri'
schaft zu Berlin, aus dem Jahr 1842, s. 63, and in the Jahrbuchern fur
Wissenschaftliche Kritik Jahrg. 1840, s. 196.

§ Elie de Beaumont, in the Annates des Sciences Naturelles, t. xv., p.
362-372. " In approaching the primitive masses of Moot Rosa, and the
mountains situated to the west of Coni, we pei'ceive that the secondary
strata gradually lose the characters inherent in their mode of deposition.
Frequently assuming a character apparently aiising from a perfectly

tiocKS. 261

found in rocks, which have some claim to be considered as
mica slate, and in the schistose group in the western part of
the island of Elba, near the promontory of Calamita, and the
Fichtclgebirge in Baireuth, between Lomitz and Markleiten.*
Jasper, which.f as I have already remarked, is a production
formed by the volcanic action of augitic porphyry, could only
be obtained in small quantities by the ancients, while another
material, very generally and efficiently used by them in the
arts, was granular or saccharoidal marble, which is likewise
to be regarded solely as a sedimentary stratum altered by ter-
restrial heat and by proximity with erupted rocks. This opin-
ion is corroborated by the accurate observations on the phe-
nomena of contact, by the remarkable experiments on fusion

distinct cause, but not losing their stratification, they somewhat resem-
ble in their physical structure a brand of half-consumed wood, in which
we can follow the traces of the ligneous fibers beyond the spots which
continue to present the natural characters of wood." (See, also, the
Annales des Scie?ices NaturcUes, t. xiv., p. 118-122, and von Dechen,
Gepgnosie, s. 553.) Among the most striking proofs of the transforma-
tion of rocks by Plutonic action, we must place the belemnites in the
6chist3 of Nuftenen (in the Alpine valley of Eginen and in the Gries-
glaciers), and the belemnites found by M. Charpentier in the so-called
primitive limestone on the western descent of the Col de la Seigne, be-
tween the Enclove de Monjovet and the chdlet of La Lanchette, and
which he showed to me at Bex in the autumn of 1822 {Annates de
Chimie, t. xxiii., p. 262).

* Hoffmann, in Poggend., Annalen, bd. xvi., s. 552, "Strata of tran
Bition argillaceous schist in the Fichtelgebirge, which can be traced for
a length of 16 miles, are transformed into gneiss only at the two ex-
tremities, where they come in contact with granite. We can there
follow the gradual formation of the gneiss, and the development of the
mica and of the feldspathic amygdaloids, in the interior of the argilla-
ceous schist, which indeed contains in itself almost all the elements of
these substances."

t Among the works of art which have come down to us from the an
cient Greeks and Romans, we observe that none of any size — as columns
or large vases — are formed from jasper ; and even at the present day,
this substance, in large masses, is only obtained from the Ural Mountains.
The material worked as jasper from the Rhubarb Mountain (Ra^eniaga
Sopka), in Altai, is a beautiful ribboned porphyry. The word jasper
is derived from the Semitic languages ; and from the confused descrip-
tions of Theophrastus {De Lapidibus, 23 and 27) and Pliny (xxxvii., 8
and 9), who rank jasper among the " opaque gems," the name appears
to have been given to fragments of jaspachai, and to a substance which
the ancients termed jasponyx, which we now know as opal-jasper.
Pliny considers a piece of jasper eleven inches in length so rare as to
require hifi mentioning that he had actually seen such a specimen :
" Magnitudinem jaspidis undecim unciarum vidimus, formatamque inde
effigiem Neronis thoracatam." According to Theophrastus, the stone
which he calls emerald, and from which large obelisks were cut, must
have heen an imperfect jasper.

262 COSMOS.

made by Sir James Hall more than half a century ago, and
by the attentive study of granitic veins, w^hich has contributed
so largely to the establishment of modern geognosy. Some-
times the erupted rock has not transformed the compact into
granular limestone to any great depth from the point of con-
tact. Thus, for instance, we meet with a sHght transforma-
tion— a penumbra — as at Belfast, in Ireland, where the ba-
saltic veins traverse the chalk, and, as in the compact cal-
careous beds, which have been partially inflected by the con-
tact of syenitic granite, at the Bridge of Boscampo and the
Cascade of Conzocoli, in the Tyrol (rendered celebrated by
the mention made of it by Count Mazari Peucati).* Another
mode of transformation occurs where all the strata of the com-
pact limestone have been changed into granular limestone by
the action of granite, and syenitic or dioritic porphyry. f

I would here wish to make special mention of Parian and
Carrara marbles, which have acquired such celebrity from the
noble works of art into which they have been converted, and
which have too long been considered in our geognostic collec
tions as the main types of primitive limestone. The action
of granite has been manifested sometimes by immediate con-
tact, as in the Pyrenees,^ and sometimes, as in the main land
of Greece, and in the insular groups in the JEgean Sea, through
the intermediate layers of gneiss or mica slate. Both cases
presuppose a simultaneous but heterogeneous process of trans

* Humboldt, Lettre a M. Brochant de Villiers, in the Annales de
Chimie et de Physique, t. xxiii., p. 261 ; Leop. vou Buch, Oeog. Briefe
uber das sudliche Tyrol, s. 101, 105, und 273.

t Oa the transformation of compact into granular limestone by the
action of granite, in the Pyrenees at the Montagnes de Rancie, see
Dufr^noy, in the M^moires G6ologiques, t. ii., p. 440 ; and on similai
changes in the Montagnes de VOisans, see Elie de Beaumont, in the
M6m. Giolog., t. ii., p. 379-415; on a similar effect produced by the
action of dioiitic and pyroxenic porphyry (the ophite described by Elie
de Beaumont, in the G6ologie de la France, t. i., p. 72), between Tolosa
and St. Sebastian, see Dnfreuoy, in the AT^m. G6olog., t. ii., p. 130 ; and
by syenite in the Isle of Skye, where the fossils in the altered limestone
may still be distinguished, see Von Dechen, in his G^ognogie, p. 573.
In the transformation of chalk by contact with basalt, the transposition
of the most minute particles in the processes of crystallization and
granulation is the more remarkable, because the excellent microscopic
investigations of Ehrenberg have shown that the particles of chalk pre-
viously existed in the form of closed rings. See Poggend., Annalen dei
Physik, bd. xxxix., s. 105; and on the rings of aragonite deposited
from solution, see Gustav Rose in vol. xlii., p. 354, of the same journal.

X Beds of granular limestone in the granite at Port d'Oo and in th«
Mont -de Labourd. See Charpentier. Constitution G^ologique des Pyr^
nies, p. 144, 146.

ROCKS. 263

formation. In Attica, in the island of Eubosa, and in the
Peloponnesus, it has been remarked, " that the limestone,
when superposed on mica slate, is beautiful and crystalline in
proportion to the purity of the latter substance and to the
femallness of its argillaceous contents ; and, as is well known,
this rock, together with beds of gneiss, appears at many points,
at a considerable depth below the surface, in the islands of
Pares and Antiparos."* We may here infer the existence of
an imperfectly metamorphosed flotz formation, if faith can be
yielded to the testimony of Origen, according to whom, the
ancient Eleatic, Xenophanes of Colophonf (who supposed the
whole earth's crust to have been once covered by the sea), de-
clared that marine fossils had been found in the quarries of
Syracuse, and the impression of a fish (a sardine) in the deepest
rocks of Pares. The Carrara or Luna marble quarries, which
constituted the principal source from which statuary marble
was derived even prior to the time of Augustus, and which
will probably continue to do so until the quarries of Pares
shall be reopened, are beds of calcareous sandstone — macigno
— altered by Plutonic action, and occurring in the insulated
mountain of Apuana, between gneiss-like mica and talcose
schist. $ Whether at some points granular limestone may
not have been formed in the interior of the earth, and been
raised by gneiss and syenite to the surface, where it forms
vein-like fissures,^ is a question on which I can not hazard
an opinion, owing to my own want of personal knowledge of
the subject.

* Leop. vou Buch, Descr. des Canaries, p. 394 ; Fiedler, Reise durch
das Kdnigreich Griechenland, th. ii., s., 181, 190, mid 516.

t I have previously alluded to the remarkable passage in Origen's
Philosopkumena, cap. 14 (Opera, ed. Delarue, t. i., p. 893). From the
whole context, it seems very improbable that Xenophanes meant an
impjiession of a laurel (tvttov dd<pvec) instead of an imi^ression of a fish
(tvttov acpvijg). Delarue is wrong in blaming the correction of Jacob
Gronovius in changing the laurel into a sardcl. The petrifaction of a
fish is also much more probable than the natural picture of Silenus,
which, according to Pliny (lib. xxxvi., 5), the quarry-men are stated to
have met with in Parian marble from Mount Marpessos. Servius ad
Virg., ^n., vi., 471.

X On the geognostic relations of Carrara ( The City of the Moon, Strabo,
lib. v., p. 222), see Savi, Osservazioni sui terreni aniichi Toscani, ir
the Nuovo Giornale de^ Letterati di Pisa, and Hoffmann, in Karsten'»
Archiv fur Mineralogie, bd. vi., s. 258-263, as well as in his Geogn
Reise durch Italien, s. 244-265.

§ According to the assumption of an excellent and very experiencec
observer, Karl von Leonhard. See his Jahrbtich fur Mineralogie, 1834
«. 329, and Bernhard Cotta, Geognosie, s. 310.

264 COSMOS.

According to the admirable oLservations of Leopold ron
Buch, the masses of dolomite fomid in Southern Tyrol, and on
the Italian side of the Alps, present the most remarkable in-
stance of metamorphism produced by massive eruptive rocks
on compact calcareous beds. This formation of the lime'stone
seems to have proceeded from the fissures which traverse it in
all directions. The cavities are every where covered with
rhomboidal crystals of magnesian bitter spar, and the whole
formation, without any trace of stratification, or of the fossil
remains which it once contained, consists only of a granular
aggregation of crystals of dolomite. Talc laminae lie scattered
here and there in the newly-formed rock, traversed by masses
of serpentine. In the valley of the Fassa, dolomite rises per-
pendicularly in smooth walls of dazzling whiteness to a height
of many thousand feet. It forms sharply-pointed conical
mountains, clustered together in large numbers, but yet not in
contact with each other. The contour of their forms recalls to
mind the beautiful landscape with which the rich imagination
of Leonardi da Vinci has embellished the back-ground of the
portrait of Mona Lisa.

The geognostic phenomena which we are now describing,
and which excite the imagination as well as the powers of the
intellect, are the result of the action of augitic porphyry man-
ifested in its elevating, destroying, and transforming force.*
The process by which limestone is converted into dolomite is
not regarded by the illustrious investigator who first drew at-
tention to the phenomenon as the consequence of the talc being
derived from the black porphyry, but rather as a transforma-
tion simultaneous with the appearance of this erupted stone
through wide fissures filled with vapors. It remains for future
inquirers to determine how transformation can have been effect-
ed without contact with the endogenous stone, where strata
of dolomite are found to be interspersed in limestone. Where,
in this case, are we to seek the concealed channels by which
the Plutonic action is conveyed ? Even here it may not, how-
ever, be necessary, in conformity with the old Roman adage,
to believe " that much that is alike in nature may have been
formed in wholly different»ways." When we find, over widely
extended parts of the earth, that two phenomena are always
associated together, as, for instance, the occurrence of mela-

* Leop. von Bucb, Geognostische Brief e an Alex, von Humboldt, 1824,
«. 86 and 82 ; also in the Annalen de Chemie, t. xxiii., p. 276, and in the
Abhandl. der Berliner Akad. ans der Jah-m 1822 tmd 1823, s. 83-136 J
Von Dechen, Geognosie, s. 574-576

ROCKS. 265

phyre and the transformation of compact lirJestone into a crys-
talline mass difiering in its chemical character, we are, to a
certain degree, justified in believing, where the second phe-
nomenon is manifested unattended by the appearance of the
first, that this apparent contradiction is owing to the absence,
in certain cases, of some of the conditions attendant upon the
exciting causes. Who would call in question the volcanic na-
ture and igneous fluidity of basalt merely because there are
some rare instances in which basaltic veins, traversing beds
of coal or strata of sandstone and chalk, have not materially
deprived the coal of its carbon, nor broken and slacked the
sandstone, nor converted the chalk into granular marble ]
Wherever we have obtained even a faint light to guide us in
the obscure domain of mineral formation, we ought not un-
gratefully to disregard it, because there may be much that is
still unexplained in the history of the relations of the transi-
tions, or in the isolated interposition of beds of unaltered strata.

After having spoken of the alteration of compact carbonate
of lime into granular limestone and dolomite, it still remains
for us to mention a third mode of transformation of the same
mineral, which is ascribed to the emission, in the ancient pe-
riods of the world, of the vapors of sulphuric acid. This trans-
formation of limestone into gypsum is analogous to the pene-
tration of rock salt and sulphur, the latter being deposited
from sulphureted aqueous vapor. In the lofty Cordilleras of
Quindiu, far from all volcanoes, I have observed deposits of
sulphur in fissures in gneiss, while in Sicily (at Cattolica, near
Girgenti), sulphur, gypsum, and rock salt belong to the most
recent secondary strata, the chalk formations.^ I have also
seen, on the edge of the crater of Vesuvius, fissures filled with
rock salt, which occurred in such considerable masses as occa-
sionally to lead to its being disposed of by contraband trade.
On both declivities of the Pyrenees, the connection of dior:t>
and pyroxene, and dolomite, gypsum, and rock salt, can not be
questioned ;t and here, as in the other phenomena which we
have been considering, every thing bears evidence of the ac-
tion of subterranean forces on the sedimentary strata of the
ancient sea.

There is much difficulty in explaining the origin of the beds
of pure quartz, which occur in such large quantities in South
America, and impart so peculiar a character to the chain of

* Hoffman, Geogn. Reise, edited by Von Dechen, s. 113-119, and
380-386; Poggeud., Annalen der P^sik, bd. xxvi., s. 41.

r Duf'renoy, in the Memoires GiM^iqnes, t. ii., p. ] 45 and 17.9.
Vol. I.— M

266 COSMOS.

the Andes * In descending toward the South Sea, fiom Cax-
amarca toward Guangamarca, I have observed vast masses
of quartz, from 7000 to 8000 feet in height, superposed some-
times on porphyry devoid of quartz, and sometimes on diorite.
Can these beds have been transformed from sandstone, as
Ehe de Beaumont conjectures in the case of the quartz strata
on the Col de la Poissonniere, east of Brianfon ?t In the
Brazils, in the diamond district of Minas Geraes and St. Paul,
which has recently been so accurately investigated by Clausen,
Plutonic action has developed in dioritic veins sometimes ordi-
nary mica, and sometimes specular iron in quartzose itacol-
umite. The diamonds of Grammagoa are imbedded in strata
of solid silica, and are occasionally enveloped in laminae of
mica, hke the garnets found in mica slate. The diamonds
that occur furthest to the north, as those discovered in 1829
at 58*^ lat., on the European slope of the Uralian Mountains,
bear a geognostic relation to the black carboniferous dolomite
of AdolfTskoiJ and to augitic porphyry, although more accu-
rate observations are required in order fully to elucidate this
subject.

Among the most remarkable phenomena of contact, we
must, finally, enumerate the formation of garnets in argilla-
ceous schist in contact with basalt and dolerite (as in Northum-
berland and the island of Anglesea), and the occurrence of a
vast number of beautiful and most various crystals, as garnets,
vesuvian, augite, and ceylanite, on the surfaces of contact be-
tween the erupted and sedimentary rock, as, for instance, on
the junction of the syenite of Monzon with dolomite and com-
pact limestone. § In the island of Elba, masses of serpentine,
which perhaps nowhere more clearly indicate the character of
erupted rocks, have occasioned the sublimation of iron glance
and red oxyd of iron in fissures of calcareous sandstone.il We
still daily find the same iron glance formed by sublimation
from the vapors and the walls of the fissures of open veins on
the margin of the crater, and in the fresh lava currents of the
volcanoes of Stromboli, Vesuvius, and -^tna.lF The veins that

* Humboldt, Essai Qeogn. sur le Gisement des Roches, p. 93 ; AaU
Centrale, t. iii., p. 532.

t Elie de Beaumont, in the Annates des Sciences Naturelles, t. xv., j)
362 ; Murchison, Silurian System, p. 286.

t Rose, Reise nach dem Ural, bd. i., s. 364 und 367.

§ Leop. von Buch, Briefe, s. 109-129. See, also, Elie de Beaumont
On the Contact of Granite with the Beds of the Jura, in the Mim. Giol.
t. ii., p. 408. II Hoffman, Reise, s. 30 und 37.

\ On the chemical process in tht|(formation of specular iroti, see Gay

ROCKS. 267

are thus formed beneath our eyes by volcanic forces, where
the contiguous rock has already attained a certain degree of
solidification, show us how, in a similar manner, mineral and
metallic veins may have been every where formed in the more
ancient periods of the world, where the solid but thinner crust
of our planet, shaken by earthquakes, and rent and fissured
by the change of volume to which it was subjected in cooling,
may have presented many communications with the interior,
and many passages for the escape of vapors impregnated with
earthy and metallic substances. The arrangement of the par-
ticles in layers parallel with the margins of the veins, the regu-
lar recurrence of analogous layers on the opposite sides of the
veins (on their different walls), and, finally, the elongated cel-
lular cavities in the middle, frequently afford direct evidence
of the Plutonic process of sublimation in metalliferous veins.
As the traversing rocks must be of more recent origin than
the traversed, we learn from the relations of stratification ex-
isting between the porphyry and the argentiferous ores in the
Saxon mines (the richest and most important in Germany),
that these formations are at any rate more recent than the
vegetable remains found in carboniferous strata and in the red
sandstone.*

All the facts connected with our geological hypotheses on
the formation of the earth's crust and the metamorphism of
rocks have been unexpectedly elucidated by the ingenious
idea which led to a comparison of the slags or scoriae of our
smelting furnaces with natural minerals, and to the attempt
of reproducing the latter from their elements.! In all these
operations, the same affinities manifest themselves which de-
termine chemical combinations both in our laboratories and
in the interior of the earth. The most considerable part of

Lussac, in the Annates de Chimie, t. xxii., p. 415, and Mitscherlich, in
Poggend., Annalen, bd. xv., s. 630. Moreover, crystals of olivine have
been formed (probably by sublimation) in the cavities of the obsidian
of Cerro del Jacal, which I brought from Mexico (Gustav Rose, in
Poggend., Annalen, bd. x., s. 323). Hence olivine occurs in basalt,
lava, obsidian, artificial scorife, in meteoric stones, in the syenite of Elf-
dale, and (as hyalosiderite) in the wacke of the Kaiserstuhl.

* Constantin von Beust, Ueber die Porphyrgebilde, 1835, s. 89-96 ;
also his Beleuchtung der Werner'sche?i Gangtheorie, 1840, s. 6 ; and C.
von Wissenbach, Abbildungen merkwurdiger Gangverhdltnisse, 1836, fig.
12. The ribbon-like structure of the veins is, however, no more to be
regarded of general occurrence than the periodic order of the different
members of these masses.

t Mitscherlich, Ueber die kunstliche Darstelhing der Mineralien, in
the Abhandl. der Akademie der Wi$s. zti Berlin, 1822-3, s. 25-41

268 COSMOS.

the simple minerals which characterize the more generally
diffused Plutonic and erupted rocks, as well as those on which
they have exercised a metamorphic action, have been produced
in a crystalline state, and with perfect identity, in artificial
mineral products. We must, however, distinguish here be-
tween the scoriae accidentally formed, and those which have
been designedly produced by chemists. To the former belong
feldspar, mica, augite, olivine, hornblende, crystallized oxyd
of iron, magnetic iron in octahedral crystals, and metallic
titanium ;* to the latter, garnets, idocrase, rubies (equal in
hardness to those found in the East), olivine, and augite. t
These minerals constitute the main constituents of granite,
gneiss, and mica schist, of basalt, dolerite, and many porphy-
ries. The artificial production of feldspar and mica is of most
especial geognostic importance with reference to the theory of
the formation of gneiss by the metamorphic agency of argilla-
ceous schist, which contains all the constituents of granite,

* In scoria?, ciystals of feldspar have been discovered by Heine in
the refuse of a furnace for copper fusing, near Sangerhausen, and ana-
lyzed by Kersten (Poggend., Annalen, bd. xxxiii., s. 337); crystals of
augite in scoriae, at Sahle (Mitscherlich, in the Abh^Jidl. der Akad. zu
Berlin, 1822-23, s. 40); of olivine by Seifstrom (Leonhard, Basali-Ge-
Hide, bd. ii., s. 495) ; of mica in old scoriae of Scbloss Garpenberg
(Mitscherlich, in Leonhard, op. cit., s. 506) ; of magnetic iron in the
scoriae of Chatillon sur Seine (Leonhard, s. 441) ; and of micaceous iron
in potter's clay (Mitscherlich, in Leonhard, op. cit., s. 234).

[See Ebelmer's papers in Ann. de Chimie et de Physique, 1847 ; also
Report on the Crystalline Slags, by John Pei'cy, M.D., F.R.S., and
William Hallows Miller, M.A., 1847. Dr. Percy, in a communication
W\\h which he has kindly favored me, says that the minerals which he
has found artificially produced and proved by analysis are Humboldtil-
ite, gehlenite, olivine, and magnetic oxyd of iron, in octahedral crys-
tals. He suggests that the circumstance of the production of gehlenite
at a high temperature in an iron furnace may possibly be made avail-
able by geologists in explaining the formation of the rocks in which the
natural mineral occurs, as in Fassathal in the Tyrol.] — Tr.

t Of minerals purposely produced, w^e may mention idocrase and
garnet (Mitscherlich, in Poggend., Annalen der Physik, bd. xxxii., s.
340); ruby (Gaudin, in the Comptes Rendus de VAcad6mie de Science,
t. iv.. Part i., p. a99); olivine and augite (Mitscherlich and Berthier, in
the Annales de Chimie et de Physique, t. xxiv., p. 376). Notwithstand
ing the greatest possible similarity in crystalline form, and perfect iden
tity in chemical composition, existing, according to Gustav Rose, be-
tween augite and hornblende, hornblende has never been found accom-
f)anying augite in scoriae, nor have chemists ever succeeded in artificial-
y producing either hornblende or feldspar (Mitscherlich in Poggend.,
Annalen, bd. xxxiii., s. 340, and Rose, Reise nach dem Ural, bd. ii., s
358 und 363). See, also, Beudant, in XheMem. de V Acad, des Sciences^
t. viii., p. 221, and Becquerel's ingenious experiments in his TraU^ dt
I Electric'tS, t. i., p. 334 ; t. iii., p. 218; and t, v., p. 148 and 185

ROCKS. 269

potash not excepted * It would not b(3 very surprising, there*
fore, as is well observed by the distinguished geognosist, Von
Dechen, if we were to meet with a fragment of gneiss formed
on the walls of a smelting furnace which was built of argilla-
ceous slate arj^ graywacke.

After having taken this general view of the three classes
of erupted, sedimentary, and metamorphic rocks of the earth's
crust, it still remains for us to consider the fourth class, com-
prising conglomerates, or rocks of detritus. The very term
recalls the destructi&a which the earth's crust has suffered,
and likewise, perhap*^ reminds u? of the process of cementation,
which has connected together, by means of oxyd of iron, or of
some argillaceous and calcareous substances, the sometimes
rounded and sometimes angular portions of fragments. Con-
glomerates and rocks of detritus, when considered in the widest
sense of the term, manifest characters of a double origin. The
substances which enter into their mechanical composition have
not been alone accumulated by the action of the waves of the
sea or currents of fresh water, for there are some of these rocks
the formation of which can not be attributed to the action of
water. " When basaltic islands and trachytic rocks rise on
fissures, friction of the elevated rock against the walls of the
fissures causes the elevated rock to be inclosed by conglom-
erates composed of its own matter. The granules composing
the sandstones of many formations have been separated rather
by friction against the erupted volcanic or Plutonic rock than
destroyed by the erosive force of a neighboring sea. The ex-
istence of these friction conglomerates, which are met with in
enormous masses in both hemispheres, testifies the intensity
of the force with which the erupted rocks have been propelled
from the interior through the earth's crust. This detritus
has subsequently been taken up by the waters, which have
then deposited it in the strata which it still covers. "t Sand-
stone formations are found imbedded in all strata, from the
lower Silurian transition stone to the beds of the tertiary form-
ations, superposed on the chalk. They are found on the
margin of the boundless plains of the New Continent, both
within and without the tropics, extending like breast-worka
along the ancient shore, against which the sea once broke in
foaming waves.

* D'Aubuisson, ia the Journal de Physique, t. Ixviii., p. 128.

T Leop. von Buch, Geognost. Brief e, s. 75-82, where it is also shown
why the new red sandstone (the Todtliegende of the Thuringian flSta
formation) and the coal measures must be regarded as produced by
erupted porphyry.

270 COSMOS.

If we cast a glance on the geograpliical distribution of
rocks, and their relations in space, in that portion of the earth's
crust which is accessible to us, we shall find that the most
universally distributed chemical substance is silicic add, gen-
erally in a variously-colored and opaque form. ^ Next to solid
silicic acid we must reckon carbonate of lime, and then the
combinations of silicic acid with alumina, potash, and soda,
with lime, magnesia, and oxyd of iron.

The substances which we designate as rocks are determin-
ate associations of a small number of minerals, in which some
combine parasitical ly, as it were, with others, but only under
definite relations ; thus, for instance, although quartz (silica),
feldspar, and mica are the principal constituents of granite,
these minerals also occur, either individually or collectively,
in many other formations. By way of illustrating how the
quantitative relations of one feldspathic rock difler from anoth-
er, richer in mica than the former, I would mention that, ac-
cording to Mitscherlich, three times more alumina and one
third more silica than that possessed by feldspar, give the con-
stituents that enter into the composition of mica. Potash is
contained in both — a substance whose existence in many kinds
of rocks is probably antecedent to the dawn of vegetation on
the earth's surface.

The order of succession, and the relative age of the different
formations, may be recognized by the superposition of the sed-
imentary, metamorphic, and conglomerate strata ; by the na-
ture of the formations traversed by the erupted masses, and
— with the greatest certainty — ^by the presence of organic re-
mains and the differences of their structure. The application
of botanical and zoological evidence to determine the relative
age of rocks — this chronometry of the earth's surface, which
was already present to the lofty mind of Hooke — indicates ono
of the most glorious epochs of modern geognosy, which has
finally, on the Continent at least, been emancipated from the
sway of Semitic doctrines. PalsBontological investigations
have imparted a vivifying breath of grace and diversity to the
science of the solid structure of the earth.

The fossiliferous strata contain, entombed within them, the
floras and faunas of by-gone ages. We ascend the stream of
time, as in our study of the relati9ns of superposition we de-
scend deeper and deeper through the different strata, in which
lies revealed before us a past world of animal and vegetable
life. Far-extending disturbances, the elevation of great mount-
ain chains, whose relative ages we are able to define, attest the

PALEONTOLOGY. 271

destruction of ancient and the manifestation of recent organ-
isms. A few of these older structures have remained in the
midst of more recent species. Owing to the limited nature of
our knowledge of existence, and from the figurative terms by
which we seek to hide our ignorance, we apply the appellation
recent structure to the historical phenomena of transition man-
ifested in the organisms as well as in the forms of primitive
seas and of elevated lands. In some cases these organized
structures have been preserved perfect in the minutest details
of tissues, integument, and articulated parts, while in others,
the animal, passing over soft argillaceous mud, has left noth-
ing but the traces of its course,*" or the remains of its undi-
gested food, as in the coprolites.f In the lower Jura forma-
tions (the lias of Lyme Regis), the ink bag of the sepia has
been so wonderfully preserved, that the material, which myr-

* [In certain localities of the new red sandstone, in the Valley of the
Connecticut, numerous tridactyl markings have been occasionally ob-
served on the surface of the slabs of stone w^hen split asunder, in like
manner as the ripple-marks appear on the successive layers of sandstone
in Tilgate Forest. Some remarkably distinct impressions of this kind,
at Turner's Falls (Massachusetts), happening to attract the attention of
Dr. James Deane, of Greenfield, that sagacious observer was struck
with their resemblance to the foot-marks left on the mud-banks of the
adjacent river by the aquatic birds which had recently frequented the
spot. The specimens collected were submitted to Professor G. Hitch-
cock, who followed up the inquiry with a zeal and success that have
led to the most interesting results. No reasonable doubt now exists
that the imprints in question have been produced by the tracks of bi-
peds impressed on the stone when in a soft state. The announcement
of this extraordinary phenomenon was first made by Professor Hitch-
cock, in the American Journal of Science (January, 1836), and that
eminent geologist has since published full descriptions of the different
species of imprints which he has detected, in his splendid work on the
geology of Massachusetts. — Mantell's Medals of Creation, vol. ii., p. 810.
in the work, of Dr. Mantell above referred to, there is, in vol. ii., p. 815,
an admirable diagram of a slab from Turner's Falls, covered with nu-
nieious foot-marks of birds, indicating the track of ten or twelve indi-
viduals of different sizes.] — Tr.

t [From the examination of the fossils spoken of by geologists under
the name of Coprolites, it is easy to determine the nature of the food of
the animals, and some other points ; and when, as happened occasion-
ally, the animal was killed while the process of digestion was going oii,
the stomach and intestines being partly filled with half-digested food,
and exhibiting the coprolites actually in situ, we can make out with
certainty not only the true nature of the food, but the proportionate size
of the stomach, and the length and nature of the intestinal canal. With
in the cavity of the rib of an extinct animal, the palasontologist thu3
finds recorded, in indelible characters, some of those hieroglyphics upon
which he founds his history. — The Ancient World, by D. T. Ansled,
1847, p. 173.]— ?'^.

272 COSMOS.

iads of years ago might have served the animal to conceal it-
self from its enemies, still yields the color with which its image
may be drawn.* In other strata, again, nothing remains but
the faint impression of a muscle shell ; but even this, if it be-
long to a main division of mol]usca,t may serve to show th«a
traveler, in some distant land, the nature of the rock in which
it is found, and the organic remains with which it is associa-
ted. Its discovery gives the history of the country in which ii
occurs.

The analytic study of primitive animal and vegetable lift
has taken a double direction : the one is purely morpholog-
ical, and embraces, especially, the natural history and phys-
iology of organisms, filling up the chasms in the series of stiU
living species by the fossil structures of the primitive world.
The second is more specially geognostic, considering fossil re-
mains in their relations to the superposition and relative age
of the sedimentary formations. The former has long predora
inated over the latter, and an imperfect and superficial com
parison of fossil remains with existing species has led to errors,
which may still be traced in the extraordinary names applied
to certain natural bodies. It was sought to identify all fossil
species with those still extant in the same manner as, in the
sixteenth century, men were led by false analogies to com-
pare the animals of the New Continent with those of the Old.
Peter Camper, Sommering, and Blumenbach had the merit
of being the first, by the scientific application of a more ac-

* A discovery made by Miss Mary Anning, who was likewise the
discoverer of the coprolites of fish. These coprolites, and the excre-
ments of the Ichthyosauri, have been found in such abundance in En-
gland (as, for instance, near Lyme Regis),, that, according to Buckland's
expression, they lie like potatoes scattered in the ground. See Buck-
land, Geolo'^y considered with reference to Natural Theology, vol. i., p.
188-202 and 305. With respect to the hope expressed by Hooke " to
raise a chronology" from the mere study of broken and fossilized shells
" and to state the interval of time wherein such or such catastrophes
and mutations have happened," see his Posthumous Works, Lecture,
Feb. 29, 1G88.

[Still more wonderful is the preservation of the substance of the an-
imal of certain Cephalopodes in the Oxford clay. In some specimens
recently .obtained, and described by Professor Owen, not only the ink
bag, but the muscular mantle, the head, ^nd its crown of arms, are all
preserved in connection with the belemnite shell, while one specimen
exhibits the large eyes and the funnel of the animal, and the remains of
two fins, in addition to the ehell and the ink bag. See Ansted's Ancient
World, p. 147.]— Tr.

i Leop. von Buch, in the Abhandlungen der Akad. der Wiss. zu Ber
lin in dem Jahr 1837, s. 64.

PALJaONTOLOGY. 273

curate comparative anatomy, to throw light on the osteolog-
ical branch of pala3ontology — the archseology of organic life ;
but the actual geognostic views of the doctrine of fossil re-
mains, the felicitous combination of the zoological character
with the order of succession, and the relative ages of strata, are
due to the labors of George Cuvier and Alexander Brongniart.

The ancient sedimentary formations and those of transi-
tion rocks exhibit, in the organic remains contained within
them, a mixture of structures very variously situated on the
scale of progressively-developed organisms. These strata con-
tain but few plants, as, for instance, some species of Fuci,
Lycopodiaceee which were probably arborescent, Equisetaceae,
and tropical ferns ; they present, however, a singular associa-
tion of animal forms, consisting of Crustacea (trilobites with
reticulated eyes, and Calymene), Brachiopoda (Spirifer, Or-
this), elegant Sphseronites, nearly allied to the Crinoidea,* Or-
thoceratites, of the family of the Cephalopoda, corals, and,
blended with these low organisms, fishes of the most singular
forms, imbedded in the upper silurian formations. The fam-
ily of the Cephalaspides, whose fragments of the species
JPterichtys were long held to be trilobites, belongs exclusively
to the devonian period (the old red), manifesting, according
to Agassiz, as peculiar a type among fishes as do the Ichthy-
osauri and Plesiosauri among reptiles. f The Goniatites, of
the tribe of Ammonites,f are manifested in the transition
chalk, in the graywacke of the devonian periods, and even in
the latest silurian formations.

The dependence of physiological gradation upon the age of
the formations, which has not hitherto been shown with per
feet certainty in the case of invertebrata,^ is most regularly
manifested in vertebrated animals. The most ancient of
these, as we have already seen, are fishes ; next in the ordei
of succession of formation, passing from the lower to the up-
per, come reptiles and mammalia. The first reptile (a Sau-
rian, the Monitor of Cuvier), which excited the attention of
Leibnitz, 11 is found in cuperiferous schist of the Zechstein of

* Leop. von Buch, Gebirgsformationenvon Russlcmd, 1840, s. 24-40.

t Agassiz, Monograpliie des Poissons Fossiles du vieux Gris Rouge,
p. vi. and 4.

X Leop. von Buch, in the Abhandl. der Berl. Akad., 1838, s. 149-168;
Beyrich, Beiir. zur Kenntniss des Rheinischen Uebergangsgebirges, 1837,
B. 45.

$ Agassiz, Recherches sur les Poissons Fossiles, t. i., Introd., p. xviii. ;
Davy, Consolation in Travel, dial. iii.

I, A Protosaurus, according to Hermann von Meyer. The rib of 6
M 2

274 COSMOS.

Thuringia ; the Palseosaurus and Thecodontosaurus of Bris-
tol are, according to Murchison, of the same age. The Sau-
rians are found in large numbers in the muschelkalk,* in the
keuper, and in the oolitic formations, where they are the most
numerous. At the period of these formations there existed
Plesiosauri, having long, swan-like necks consisting of thirty
vertebra? ; Megalosauri, monsters resembling the crocodile,
forty-five feet in length, and having feet whose bones were
like those of terrestrial mammalia, eight species of large-eyed
Ichthyosauri, the Geosaurus or Lacerta gigantea of Som-
mering, and, finally, seven remarkable species of Pterodac-
tyles,t or Saurians furnished with membranous wings. In
the chalk the number of the crocodilial Saurians diminishes,
although this epoch is characterized by the so-called crocodile
of Maestrieht (the Mososaurus of Conybeare), and the colos-
sal, probably graminivorous Iguanodon. Cuvier has found
animals belonging to the existing families of the crocodile in
the tertiary formation, and Scheuchzer's antediluvian man
(Jiomo diluvii testis), a large salamander allied to the Ax-
olotl, which I brought with me from the large Mexican lakes,
belongs to the most recent fresh-water formations of OEnin-
gen.f

The determination of the relative ages of organisms by the
superposition of the strata has led to important results regard-
ing the relations which have been discovered between extinct
families and species (the latter being but few in number) and
those which still exist. Ancient and modern observations
soncur in showing that the fossil floras and faunas differ more
from the present vegetable and animal forms in proportion as
they belong to lower, that is, more ancient sedimentary for-
mations. The numerical relations first deduced by Cuvier

Saurian asserted to have been found in the mountain limestone (car-
bonate of lime) of Northumberland (Herra.von Meyev, Palceologica, s
•299), is regarded by Lyell (Geology, 1832, vol. i., p. 148^ as very doubt-
ful. The discoverer himself referred it to the alluvial strata which
cover the mountain limestone.

* F. von Alberti^ Monographie des Bunten Sandsteins, Muschelkalkt
und Keupers, 1834, s. 119 und 314.

t See Hermann von Meyer's ingenious considerations regarding the
organization of the flying Saurians, in his Palceologica, s. 228-252. In
the fossil specimen of the Fterodactylus crassirostris, which, as well as
the longer known P. longirostris (Ornithocephalus of Sommering), was
found at Solenhofen, ir the lithographic slate of the upper Jura forma-
tion, Professor Goldfuss has even discovered traces of the membranous
wing, " with the impressions of curling tufts of hair, in some places a
full inch in length." ^ t [Ansted's Ancient World, p. 56.] — Tr.

PALEONTOLOGY. 275

from the great phenomena of the metamorphism of organic
life,* have led, through the admirable labors of Deshayes and
Lyell, to the most marked results, especially with reference to
the different groups of the tertiary formations, which contain
a considerable number of accurately investigated structures.
Agassiz, who has examined 1700 species of fossil fishes, and
who estimates the number of living species which have either
been described or are preserved in museums at 8000, expressly
Bays, in his masterly work, that, " with the exception of a few
small fossil fishes peculiaf to the argillaceous geodes of Green-
laud, he has not found any animal of this class in all the tran
sition, secondary or tertiary formations, which is specifically
identical with any still extant fish." He subjoins the im-
portant observation " that in the lower tertiary formations,
for instance, in the coarse granular calcareous beds, and in the
London clay,t one third of the fossil fishes belong to wholly
extinct famihes. Not a single species of a still extant family
is to be found under the chalk, while the remarkable family
of the Saicroidi (fishes with enameled scales), almost allied
to reptiles, and which are found from the coal beds — in which
the larger species lie — to the chalk, where they occur individ-
ually, bear the same relation to the two families (the Lepi-
dosteus and Polypterus) which inhabit the American rivers
and the Nile, as our present elephants and tapirs do to the
Mastodon and Anaplotheriun of the primitive world. "$

The beds of chalk which contain two of these sauroid fishes
und gigantic reptiles, and a whole extinct world of corals and
aiuscles, have been proved by Ehrenberg's beautiful discov-
eries to consist of microscopic Polythalamia, many of which
still exist in o.ur seas, and in the middle latitudes of the North
^ea and Baltic. The first group of tertiary formations above
the chalk, which has been designated as belonging to the
Eocene Period, does not, therefore, merit that designation,
since " the dawn of the world in which we live extends much
further back in the history of the past than we have hitherto
supposed."^

As we have already seen, fishes, which are the most ancient
of all vertebrata, are found in the silurian transition strata,

* Ouvier, Recherches sur les Ossemens Fossiles, t. i., p. 52-57. See,
also, the geological scale of epochs m Phillips's Geology, 1837, p. 166-
185. t [See Wonders of Geology, vol. i., p. 230.]— T'r

X Agassiz, Poissons Fossiles, t. i., p. 30, and t. iii., p. 1-52 ; Buck-
land, Geology, vol. i., p. 273-277.

$ Eiirenberg, Ueber noch jtetzt lebende Thierarten de'^ Kreidebtldnnsr
In the Abhandl. der Berli le' Akad., 1839, s. 164.

276 COSMOS.

and then uninterruptedly on through all formations to the
strata of the tertiary period, while Saurians begin with the
zeehstone. In like manner, we find the first mammalia
{Thylacotherium Prevostii, and T. Bucklandii, which are
nearly allied, according to Valenciennes,^ with marsupial an-
imals) in the oolitic formations (Stonesfield schist), and the
first birds in the most ancient cretaceous strata.f Such are,
according to the present state of our knowledge, the lowest^*
limits of fishes, Saurians, mammalia, and birds.

Although corals and Serpulidse occur in the most ancient
formations simultaneously with highly-developed Cephalopodes
and Crustaceans, thus exhibiting the most various orders
grouped together, we yet discover very determinate laws in
the case of many individual groups of one and the same or-
ders. A single species of fossil, as Goniatites, Trilobites, or
Nummulites, sometimes constitutes whole mountains. Where
different families are blended together, a determinate succes-
sion of organisms has not only been observed with reference
to the superposition of the formations, but the association of
certain families and species has also been noticed in the lower
strata of the same formation. By his acute discovery of the
arrangement of the lobes of their chamber-sutures, Leopold
von Buch has been enabled to divide the innumerable quan-
tity of Ammonites into well-characterized families, and to
show that Ceratites appertain to the muschelkalk, Arietes to
the lias, and Goniatites to transition limestone and graywacke.§
The lower limits of Belemnites are, in the keuper, covered by
Jura limestone, and their upper limits in the chalk forma-
tions. 11 It appears, from what we now know of this subject,
that the waters must have been inhabited at the same epoch,
and in the most widely-remote districts of the world, by shell-
fish, which were, at any rate, in part, identical with the fossil
remains found in England. Leopold von Buch has discovered
exogyra and trigonia in the southern hemisphere (volcano of

* Valenciennes, in the Compies Rendus de V AcadAmie des Sciences, t.
vii., 1838, Part ii., p. 580.

t In the Weald clay; Beudant, G6ologie, p. 173. The ornitholitei
increase in number in the gypsum of the tertiary formations. Cuvier,
Ossemens Fossiles, t. ii., p. 302-328.

X [ Recent collections from the southern hemisphere show that thia
distribution was not so universal during the earlier epochs as has gen-
erally been supposed. See papers by Darwin, Sharpe, Morris, and
M'Coy, in the Geological Journal.'] — Tr.

$ Leop. von Buch, in the Abhandl. der Berl. Akad., 1830, s. 135-187

Ij Qiienstedt. Flotzgehirge Wurtembergs, 1843, s. 135.

r-AL^ONTOLOGV. 277

Maypo in Chili), and D'Orbigny has described Ammonite*
and Gryphites from the Himalaya and the Indian plains of
Cutch, these remains being identical with those found in the
old Jurassic sea of Germany and France.

The strata which are distinguished by definite kinds of pet-
rifactions, or by the fragments contained within them, form
a geognostic horizon, by which the inquirer may guide his
steps, and arrive at certain conclusions regarding the identity
or relative age of the formations, the periodic recurrence of
certain strata, their parallelism, or their total suppression. If
we classify the type of the sedimentary structures in the sim-
plest mode of generalization, we arrive at the following series
in proceeding from below upward :

1. The so-called transition rocks, in the two divisions of
upper and lower graywacke (silurian and devonian systems),
the latter being formerly designated as old red sandstone.

2. The lower trias* comprising mountain limestone, coal
measures, together with the lower new red sandstone (Todt-
liegende and Zechstein).t

3. The upper trias, including variegated sandstone,t mus-
chelkalk, and keuper.

4. Jura limestone (lias and oolite).

5. Grreen sandstone, the quader sanstein, upper and lower
chalk, terminating the secondary formations, which begin with
limestone.

6. Tertiary formations in three divisions, distinguished as
granular limestone, the lignites, and the sub-Apennine gravei
of Italy.

Then follow, in the alluvial beds, the colossal bones of the
mammalia of the primitive world, as the mastodon, dinothe-

* Quenstedt, Flotzgebirge Wurtemberga, 1843, s. 13.

t Murchison makes two divisions of the hunter sandstone, the upper
being the same as the trias of Alberti, while of the lower division, to
which the Vosges sandstone of Elie de Beaumont belongs — the zech-
atein and the todtliegende — he forms his Permian system. He makes
tlie secondary formations commence with the npper trias, that is to say,
with the upper division of our (German) bunter sandstone, while the
Permian system, the CEirboniferous or mountain limestone, and the
devonian and silurian strata, constitute his palceozoic formations. Ac-
cording to these views, the chalk and Jura constitute the upper, and
the keuper, the muschelkalk, and the bunter sandstone the lower sec-
ondary formations, while the Permian system and the carboniferous
Hmestone are the upper, and the devonian and silurian strata are the
lower palasozoic formation. The fundamental principles of lliis general
classification are developed in the great work in which this indefatiga^
ble British geologist purposes to describe the geology of a large part of
Eastern Europe

278 COSMOS.

*
rium, missiiriura, and the megatherides, among which is

Owen's sloth-hke mylodon, eleven feet in length.* Besides
these extinct families, we find the fossil remains of still extant
animals, as the elephant, rhinoceros, ox, horse, and stag. The
field near Bogota, called the Gaiwpo de Gigantes, which is
filled with the bones of mastodons, and in which 1 caused ex-
cavations to be made, lies 8740 feet above the level of the
sea, while the osseous remains, found in the elevated plateaux
of Mexico, belong to true elephants of extinct species.f The
projecting spurs of ther Himalaya, the Sewalik Hills, which
have been so zealously investigated by Captain Cautley$ and
Dr. Falconer, and the Cordilleras, whose elevations are, prob-
ably, of very different epochs, contain, besides numerous mas-
todons, the sivatherium, and the gigantic land tortoise of the
primitive world ( Colossochelys), which is twelve feet in length
and six in height, and several extant families, as elephants,
rhinoceroses, and giraffes ; and it io a remarkable fact, that
these remains are found in a zone which still enjoys the same
tropical climate which must be supposed to have prevailed at
the period of the mastodons. §

Having thus passed in review both the inorganic formations
of the earth's crust and the animal remains which are con-
tained within it, another branch of the history of organic life
still remains for our consideration, viz., the epoch of vegeta
tion, and the successive floras that have occurred simul-
taneously with the increasing extent of the dry land and the
modifications of the atmosphere. The oldest transition strata,
as we have already observed, contain merely cellular marine
plants, and it is only in the devonian system that a few cryp-
togamic forms of vascular plants ( Calami tes and Lycopodi
aceae) have been observed.il Nothing appears to corroborate

* [See Mantell's Wonders of Geology, vol. i., p. 168.] — Tr.

t Cuvier, Ossemens Fossiles, 1821, t. i., p. 157, 261, and 264. See,
also, Humboldt, Ueber die Hochebene von Bogota, in the Deutschen
Vierteljahrs-schrift, 1839, bd. i., s. 117.

X [The fossil fauna of the Sewalik range of hills, skirting the south-
ern base of the Himalaya, has proved more abundant in genera and
species of maminalia than that of any other region yet explored. As
a general expression of the leading features, it may be stated, that it
appears to have been composed of representative forms of all ages,
from the oldest of the tertiary period down to the modern, and of all th»
geographical divisions of the Old Continent grouped together into one
comprehensive fauna. Fauna Antiqua Sivaliensis, by Hugh Falconer,
M.D., and Major P. T. Cautley.]— Tr.

§ Journal of the Asiatic Society, 1844, No. 15, p. 109.

|1 Beyrich, in Karsten's ArchivfH Mineralogie, 1844, bd. xviii., s. 218

PALAEONTOLOGY. 279

the theoretical views that have been started regarding the
Bimplicity of primitive forms of organic Ufe, or that vegetable
preceded animal life, and that the former was necessarily de-
pendent upon the latter. The existence of races of men in-
habiting the icy regions of the North Polar lands, and whose
nutriment is solely derived from fish and cetaceans, shows the
possibility of maintaining life independently of vegetable sub-
stances. After the devonian system and the mountain lime-
stone, we come to a formation, the botanical analysis of which
has made such brilliant advances in modern times.* The
coal measures contain not only fern-like cryptogamic plants
and phanerogamic monocotyledons (grasses, yucca-like Lilia-
rase, and palms), but also gymnospermic dicotyledons (Coniferai
And Cycadese), amounting in all to nearly 400 species, as char-
acteristic of the coal formations. Of these we will only enu-
merate arborescent Calamites and Lycopodiacea?, scaly Lepi-
dodendra, Sigillarise, which attain a height of sixty feet, aL-l
are sometimes found standing upright, being distinguished by
a double system of vascular bundles, cactus-like Stigmarise, a
great number of ferns, in some cases the stems, and in others
the fronds alone being found, indicating by their abundance
the insular form of the dry land,t CycadeaB,^ especially palms,
although fewer in number, § Asterophyllites, having whorl-like
leaves, and allied to the Naiades, with araucaria-like ConiferaB,||
which exhibit faint traces of annual rings. This difference of
character from our present vegetation, manifested in the vege-
tative forms which were so luxuriously developed on the drier

* By the important labors of Count Sternberg, Adolphe Brongniart,
Goppert, and Lindley.

t See Robert Brown's Botany of Congo, p. 42, and the Memoir of
the unfortunate D'Urville, De la Distribution des Fougeres sur la Sur-
face du Globe Terrestre.

X Such are tlie Cycadeae discovered by Count Sternberg in the old
carboniferous formation at Radnitz, in Bohemia, and described by
Corda (two species of Cycatides and Zamites Cordai. See GSppert,
Fossile Cycadeen in den Arbeiten der Schles. Gesellschaft, fur vaterl.
CuUur im Jahr 1843, s. 33, 37, 40, and 50). A Cycadea (Pterophyllum
gonorrhacbis, Gopp.) has also been found in the carboniferous forma-
tions in Upper Silesia, at KonigshUtte.

$ Lindley, Fossil Flora, No. xv., p. 163.

II Fossil Coniferm, in Buckland's Geology, p. 483-490. Witham has
the great merit of having first recognized the existence of Conifera? in
the early vegetation of the old carboniferous formation. Almost all the
trunks of trees found in this formation were previously regarded as
palms. The species of the genus Araucaria are, however, not pecul-
iar to the coal formations of the British Islands ; they likewise occur in
Upper Silesia.

280 COSMOS.

and more elevated portions of the old red sandstone, was main-
tained through all the subsequent epochs to the most recent
chalk formations ; amid the peculiar characteristics exhibited
in the vegetable forms contained in the coal measures, there
is, however, a strikingly-marked prevalence of the same fami-
hes, if not of the same species,^ in all parts of the earth as it
then existed, as in N3W Holland, Canada, Greenland, and
Melville Island.

The vegetation of the primitive period exhibits forms which,
from their simultaneous affinity with several families of the
present world, testify that many intermediate links must have
become extinct in the scale of organic development. Thus,
for example, to mention only two instances, we would notice
the Lepidodendra, which, according to Lindley, occupy a place
between the Coniferee and the Lycopodiaceae,t and the Aran-
caria3 and pines, which exhibit some peculiarities in the union
of their vascular bundles. Even if we limit our consideration
to the present world alone, we must regard as highly import-
ant the discovery of Cycadese and Coniferas side by side with
Sagenariae and Lepidodendra in the ancient coal measures.
The ConiferaB are not only allied to Cupuliferee and Betulinse,
with which we find them associated in lignite formations, but
also with Lycopodiacese. The family of the sago-like Cyca-
dese approaches most nearly to palms in its external appear-
ance, while these plants are specially allied to Coniferee in re-
spect to the structure of their blossoms and seed. J Where
many beds of coal are superposed over one another, the fami-
lies and species are not always blended, being most frequently
grouped together in separate genera ; Lycopodiaceae and cer-
tain ferns being alone found in one bed, and Stigmariae and
Sigillariae in another. In order to give some idea of the lux-
uriance of the vegetation of the primitive world, and of the
immense masses of vegetable matter which was doubtlessly
accumulated in currents and converted in a moist condition
into coal,§ I would instance the Saarbriicker coal measures,

* Adolphe Brongniart, Prodrome d^une Hist, des Vigitaux Fossiles. p.
179 ; Buckland, Geology, p. 479 ; Endlicher and Unger, Grtindzuge der
Botanik, 1843, s. 45.5.

t " By means of Lepidodendron, a better passage is established from
flowering to flowerless plants than by either Equisetum or Cycas, or
any other known genus." — Lindley and Hutton, Fossil Flora, vol. ii.,
p. 53.

X Kiiutli, Anordnnng der Pflanzenfamilien, in his Handb. der Botanik,
8. 307 und 314.

$ That coal has not been fonned from vegetable fibers charred by

PALAEONTOLOGY. 281

where 120 beds are superposed on one another, exchisive of a
great many which are less than a foot in thickness ; the coal
beds at Johnstone, in Scotland, and those in the Creuzot, in
Burgundy, are some of them, respectively, thirty and fifty feet
in thickness,*' while in the forests of our temperate zones, the
carbon contained in the trees growing over a certain area
would-hardly suffice, in the space of a hundred years, to cover
it with more than a stratum of seven French lines in thick-
ness.f Near the mou^Ji of the Mississippi, and in the "wood
hills" of the Siberian Polar Sea, described by Admiral Wran-
gel, the vast number of trunks of trees accumulated by river
and sea water currents affords a striking instance of the
enormous quantities of drift-wood which must have favored
the formation of carboniferous depositions in the inland waters
and insular bays. There can be no doubt that these beds
owe a considerable portion of the substances of which they
consist to grasses, small branching shrubs, and cryptogamic
plants.

The association of palms and Coniferse, which we have in-
dicated as being characteristic of the coal formations, is dis-
coverable throughout almost all formations to the tertiary
period. In the present condition of the world, these genera

fire, but that it has more probably been produced in the moist way by
the action of sulphuric acid, is strikingly demonstrated by the excellent
observation made by Goppert (Karsten, Archiv fur Mineralogie, bd.
xviii., s. 530), on the conversion of a fragment of amber-tree into black
coal. The coal and the unaltered amber lay side by side. Regarding
the part which the lower forms of vegetation may have had in the for-
mation of coal beds, see Link, in the Abhandl. der Berliner Akademie
der Wissenschaften, 1838, s. 38.

* [The actual total thickness of the different beds in England varies
considerably in diflferent districts, but appears to amount in the Lanca-
shire coal field to as much as 150 feet. — Ansted's Ancient World, p.
78. For an enumeration of the thickness of coal measures in America
and the Old Continent, see Mantell's Wonders of Geology, vol. ii., p.
69.] — Tr.

t See the accurate labors of Chevandier, in the Comptes Rendus de
VAcad6mie des Sciences, 1844, t. xviii.. Part i., p. 285. In comparing
this bed of carbon, seven lines in thickness, with beds of coal, we must
not omit to consider the enormous pressure to which the latter have
been subjected from superimposed rock, and which manifests itself in
the flattened form of the stems of the trees found in these subterranean
regions.. *' The so-called wood-hills discovered in 1806 by Sirowatskoi,
on the south coast of the island of New Siberia, consist, according to
HedenstrSm, of horizontal strata of sandstone, alternating with bitu-
minous trunks of trees, forming a mound thirty fathoms in height ; at
the summit the stems were in a vertical position. The bed of <lrift-
wood is visible at five wersts' distance." — See Wrangel, Reise ltins$
der Nordhuste von Siberien, in den Jahren 1820-24, th. i., s. 102.

282 COSMOS.

appear to exhibit iio tendency whatever to occur associated
together. We have so accustomed ourselves, although erro-
neously, to regard Coniferse as a northern form, that I experi-
enced a feeling of surprise when, in ascending from the shores
of the South Pacific toward Chilpansingo and the elevated
valleys of Mexico, between the Yenta dela Moxonera and the
Alto de los Caxones, 4000 feet above the level of the sea, I
rode a whole day through a dense wood of Pinus occidentalis,
where I observed that these trees, which are so similar to the
Weymouth pine, were associated with fan palms* ( Corypha
dulcis), swarming with brightly-colored parrots. South Amer-
ica has oaks, but not a single species of pine ; and the first
time that I again saw the familiar form of a fir-tree, it was
thus associated v/ith the strange appearance of the fan palm.f
Christopher Columbus, in his first voyage of discovery, saw
Coniferse and palms growing together on the northeastern ex-
tremity of the island of Cuba, likewise within the tropics, and
scarcely above the level of the sea. This acute observer,
whom nothing escaped, mentions the fact in his journal as a
remarkable circumstance, and his friend Anghiera, the secre-
tary of Ferdinand the Catholic, remarks with astonishment
" that palmeta and pineta are found associated together in
the newly-discovered land." It is a matter of much import-
ance to geology to compare the present distribution of plants
over the earth's surface with that exhibited in the fossil floras
of the primitive world. The temperate zone of the southern
hemisphere, which is so rich in seas and islands, and where

* This corypha is the soy ate (in Aztec, zoyall), or the Palma dnlce of
the natives. See Humboldt and Bonpland, Synopsis Plant, ^quinoct.
Orbis Novi, t. i., p. 302. Professor Buschmann, who is profoundly ac-
quainted with the American languages, remarks, that the Palma soyafe
is so named in Yepe's Vocabulario de la Lengua Othomi, and that the
Aztec word zoyatl (Molina, Vocabulario en Lengua Mexicana y Castel-
lana, p. 25) recurs in names of places, such as Zoyatitlan and Zoya-
panco, near Chiapa.

t Near Baracoa and Cayos de Moya. See the Admiral's journal of
the 25th and 27th of November, 1492, and Humboldt, Examen Critique
de V Hist, de la Oiographie du Nouveau Continent, t. ii., p. 252, and t.
iii., p. 23. Columbus, who invariably paid the most remarkable atten-
tion to all natural objects, was the first to observe the difference be-
tween Podocarpus and Pinus. " I find," said he, " en la tierra aspera
del Cibao pinos que no llevan pinas (fir cones), pero portal orden com-
puestos por naturaleza, que (los finitos) parecen azeytunas del Axarafe
de Sevilla." The great botanist, Richard, when he published his ex-
cellent Memoir on CycadeaB and Coniferae, little imagined that before
the time of L'Heritier, and even before the end of the fifteenth cen-
tury, a navigator had separated Podocarpns from the Abietinese.

PALAEONTOLOGY. 283

fxopical forms blend so remarkably with those of colder parts
of the earth, presents, according to Darwin's beautiful and
animated descriptions,* the most instructive materials for the
study of the present and the past geography of plants. The
history of the primordial ages is, in the strict sense of the
word, a part of the history of plants.

Cycadese, which, from the number of their fossil species, must
have occupied a far more important part in the extinct than
in the present vegetable world, are associated with the nearly
allied Coniferae from the coal formations upward. They are
almost wholly absent in the epoch of the variegated sandstone
which contains Coniferse of rare and luxuriant structure ( Vol-
tizia, Haidingera, Albertia) ; the Cycadese, however, occur
most frequently in the keuper and lias strata, in which more
than twenty different forms appear. In the chalk, marine
plants and naiades predominate. The forests of Cycadese of
the Jura formations had, therefore, long disappeared, and even
hi the more ancient tertiary formations they are quite subor-
dinate to the Coniferae and palms. f

The lignites, or beds of brown coal$ which are present in
all divisions of the tertiary period, present, among the most
ancient cryptogamij land plants, some few palms, many Co-
niferse having distinct annual rings, and foliaceous shrubs of a
more or less tropical character. In the middle tertiary period
we again find palms and Cycadese fully established, and final-
ly a great similarity with our existmg flora, manifested in the
sudden and abundant occurrence of our pines and firs, Cupu-
liferse, maples, and poplars. The dicotyledonous stems found
in lignite are occasionally distinguished by colossal size and
great age. In the trunk of a tree found at Bonn, Noggerath
counted 792 annual rings. § In the north of France, at Yseux,
near Abbeville, oaks have been discovered in the turf moors
of the Somme which measured fourteen feet in diameter, a
thickness which is very remarkable in the Old Continent and
without the tropics. According to Goppert's excellent inves-
tigations, which, it is hoped, may soon be illustrated by plates,
it would appear that " all the amber of the Baltic comes from

* Charles Darwin, Journal of the Voyages of the Adventure and
Beagle, 1839, p. 271.

t GSppert describes three other Cycadeie (species of Cycadites aud
Pterophyllrim), fdund in the brown carboniferous. schistose chiy of Alt-
Fattel and Coraraolau, in Bohemia. They very probably belong to the
Eocene Period. GSppert, Fossile Cycadeen, s. 61.

X \_Medals of Creation, voh i., ch. v., &c. Wonders of Geology, vol. i.,
p. 278, 392.]— Tr. $ Biickland, Geology, p. .509.

284 cosMOK.

a coniferous tree, which, to judge by the still extant remains
of the wood and the bark at different ages, approaches very
nearly to our white and red pines, although forming a distinct
species. The amber-tree of the ancient world {Pinites sued-
fer) abounded in resin to a degree far surpassing that mani-
fested by any extant coniferous tree ; for not only were large
masses of amber deposited in and upon the bark, but also in
the wood itself, following the course of the medullary rays,
which, together with ligneous cells, are still discernible under
the microscope, and peripherally between the rings, being some
times both yellow and white."

" Among the vegetable forms inclosed in amber are male
and female blossoms of our native needle- wood trees and Cupu-
liferae, while fragments which are recognized as belonging tc
thuia, cupressus, ephedera, and castania vesca, blended with
those of j unipers and firs, indicate a vegetation, different froir
that of the coasts and plains of the Baltic."*^

We have now passed through the whole series of formation*
comprised in the geological portion of the present work, pro-
ceeding from the oldest erupted rock and the most ancient sed-
imentary formations to the alluvial land i)n which are scat-
tered those large masses of rock, the causes of whose general
distribution have been so long and variously discussed, and
which are, in my opinion, to be ascribed rather to the pene-
tration and violent outpouring of pent-up waters by the eleva-
tion of mountain chains than to the motion of floating blocks
of ice.t The most ancient structures of the transition forma-

* [The forests of amber-piues, Pinites succifer, were in the southeast-
ern part of what is now the bed of the Baltic, in about 55° N. lat.,
and 37° E. long. The different colors of amber are derived from local
chemical admixture. The amber contains fragments of vegetable mat-
ter, and from these it has been ascertained that the amber-pine forests
contained four other species of pine (besides the Pinites succifer), sev-
eral cypresses, yews, and junipers, with oaks, poplars, beeches, &c. —
altogether forty-eight species of trees and shrubs, constituting a flora
of North American character. There are also some ferns, mosses, fungi,
and liverworts. See Professor GSppert, Geol. Trans., 1845. Insects, spi
ders, small crustaceans, leaves, and fragments of vegetable tissue, are
imbedded in some of the masses. Upward of 800 species of insects
have been observed ; most of them belong to species, and even genera,
that appear to be distinct from any now known, but others are nearly
related to indigenous species, and some are identical with existing forms,
that inhabit mjre southern climes. — Wonders of Geology, vol. i., p. 242,
&LC.^—Tr.

T Leopold von Buch, in the Abhandl. der Akad. der Wissensch. zn
Berlin, 1814-15, s. 161 ; and in Poggend., Annalen. bd. ix , 8. 57.'> ; K^i^
de Beaumoiil, in tlie Annales des Sciences Naturelles, t. xix., p. 'l?

GEOGNOBTIU PERIODS. 285

tion with which we are acquainted are slate and graywacke,
which contain some remains of sea weeds from the siluriaii or
Cambrian sea. On what did these so-called most ancient for-
mations rest, if gneiss and mica schist must be regarded as
changed sedimentary strata? Dare we hazard a conjecture
on that which can not be an object of actual geognostic observ-
ation ? According to an ancient Indian myth, the earth is
borne up by an elephant, who in his turn is supported by a
gigantic tortoise, in order that he may not fall ; but it is not
permitted to the credulous Brahmins to inquire on what the
tortoise rests. We venture here upon a somewhat similar
problem, and are prepared to'meet with opposition in our en-
deavors to arrive at its solution. In the first formation of the
planets, as we stated in the astronomical portion of this work,
it is probable that nebulous rings revolving round the sun were
agglome-rated into spheroids, and consolidated by a gradual
condensation proceeding from the exterior toward the center.
What we term the ancient silurian strata are thus only the
upper portions of the solid crust of the earth. The erupted
rocks which have broken through and upheaved these strata
have been elevated from depths that are wholly inaccessible
to our research ; they must, therefore, have existed under the
silurian strata, and been composed of the same association of
minerals which we term granite, augite, and quartzose por-
phyry, when they are made known to us by eruption through
the surface. Basing our inquiries on analogy, we may assume
that the substances which fill up deep fissures and traverse the
Bedimentary strata are merely the ramifications of a lower de-
posit. The foci of active volcanoes are situated at enormous
depths, and, judging from the remarkable fragments which I
have found in various parts of the earth incrusted in lava cur-
rents, I should deem it more than probable that a primordial
granite rock forms the substratum of the whole stratified edi-
fice of fossil remains.* Basalt containing olivine first shows
itself in the period of the chalk, trachyte still later, while erup-
tions of granite belong, as we learn from the products of their
metamorphic action, to the epoch of the oldest sedimentary
strata of the transition formation. Where knowledge can not
be attained from immediate perceptive evidence, we may be
allowed from induction, no less than from a careful comparison
of facts, to hazard a conjecture by which granite would be re-

* See Elie de Beaumont, Descr. Giol. de la France, t. i.j p. 65 ; Beu-
dant, G4oIogie, 1844, p. 20^

286 c>!)SMos

stored to a portion of its Contested right and title to be consid-
ered as a 'primordial rock.

The recent progress of geognosy, that is to say, the more
extended knowledge of the geognostic epochs characterized by
difierence of mineral formations, by the peculiarities and suc-
cession of the organisms contained within them, and by the
position of the strata, whether uplifted or inclined horizontally
leads us, by means of the causal connection existing among all
natural phenomena, to the distribution of solids and fluids into
the continents and seas which constitute the upper crust of our
planet. We here touch upon a point of contact between geo-
logical and geographical geognosy which would constitute the
complete history of the form and extent of continents. The
limitation of the solid by the fluid parts of the earth's surface,
and their mutual relations of area, have varied very consider-
ably in the long series of geognostic epochs. They were very
diflerent, for instance, when carboniferous strata were horizon-
tally deposited on the inclined beds of the mountain limestone
and old red sandstone ; when lias and oolite lay on a substra-
tum of keuper and muschelkalk, and the chalk rested on the
slopes of green sandstone and Jura limestone. If, with Elie
de Beaumont, we term the waters in which the Jura limestone
and chalk formed a soft deposit the Jurassic or oolitic, and the
cretaceous seas, the outlines of these formations will indicate,
for the two corresponding epochs, the boundaries between the
already dried land and the ocean in which these rocks were
forming. An ingenious attempt has been made to draw maps
of this physical portion of primitive geography, and we may
consider such diagrams as more correct than those of the wan-
derings of lo or the Homeric geography, since the latter are
merely graphic representations of mythical images, while the
former are based upon positive facts deduced from the science
of geology.

The results of the investigations made regarding the areal
relations of the solid portions of our planet are as follows : in
the most ancient times, during the silurian and devonian tran-
sition epochs, and in the secondary formations, including the
trias, the continental portions of the earth were limited to in-
sular groups covered with vegetation ; these islands at a sub-
sequent period became united, giving rise to numerous lakes
and deeply-indented bays ; and, finally, when the chains of
the Pyrenees, Apennines, and Carpathian Mountains were
elevated about the period of the more ancient tertiary forma
tions, large continents appeared, having almost their present

PHYSICAL GEOGRAPHY. 281

size.* In the silurian epoch, as well as in that in which the Cy-
cadese flourished in such abundance, and gigantic saurians were
living, the dry land, from pole to pole, was probably less than it
now is in the South Pacific and the Indian Ocean. We shall
see, in a subsequent part of this work, how this prepondera-
ting quantity of water, combined with other causes, must have
contributed to raise the temperature and induce a greater uni-
formity of climate. Here we would only remark, in consider-
ing the gradual extension of the dry land, that, shortly before
the disturbmices which at longer or shorter intervals caused
the sudden destruction of so great a number of colossal verte-
brata in the diluvial period, some parts of the present conti-
nental masses must have been completely separated from one
another. There is a great similarity in South America and
Australia between still living and extinct species of animals.
In New Holland fossil remains of the kangaroo have been
found, and in New Zealand the semi-fossilized bones of an enor-
mous bird, resembling the ostrich, the dinornis of Owen,t which
is nearly allied to the present apteryx, and but little so to the re-
cently extinct dronte (dodo) of the island of Rodriguez.

The form of the continental portions of the earth may, per-
haps, in a great measure, owe their elevation above the sur-
rounding level of the water to the eruption of quartzose por-
phyry, which overthrew with violence the first great vegeta-
tion from which the material of our present coal measures was
formed. The portions of the earth's surface which we terra
plains are nothing more than the broad summits of hills and
mountains whose bases rest on the bottom of the ocean. Every
plain is, therefore, when considered according to its submarine
relations, an elevated plateau, whose inequalities have been
covered over by horizontal deposition of new sedimentary for-
mations and by the accumulation of alluvium.

* [These movements, described in so few words, were doubtless go
ing on for many thousands and tens of thousands of revolutions of our
planet. They were accompanied, also, by vast but slow changes of other
kinds. The expansive force employed in lifting up, by mighty move-
ments, the northern portion of the continent of Asia, found partial vent ;
and from partial subaqueous fissures there were poured out the tabular
masses of basalt occurring in Central India, while an extensive area of
depression in the Indian Ocean, marked by the coral islands of the Lac-
cadives, the Maldives, the great Chagos Bank, and some otllers, were
in the course of depression by a counteracting movement. — Ansted'a
Ancient World, p. 346, &c.]— Tr.

t [See American Journal of Science, vol. xlv., p. 187 ; and Medah
of Creation, vol. ii., \^. 817 ; Trans. Zoolog. Society of London, \ ol. ii. ;
Wonders of Geology, yc^ i. p 129.>-Tr.

2»h COSMOS.

Among the general subjects of contemplati< n appertaining
to a work of this nature, a prominent place must be given, first,
to the consideration of the quantity of the land raised above
the level of the sea, and, next, to the individual configuration
of each part, either in relation to horizontal extension (rela-
tions of Ibrm) or to vertical elevation (hypsometrical relations
of mountain-chains). Our planet has tvi^o envelopes, of which
one, which is general — the atmosphere — is composed of an
elastic fluid, and the other — the sea — is only locally distribu-
ted, surrounding, and therefore modifying, the form of the land.
These two envelopes of air and sea constitute a natural whole,
on which depend the difference of climate on the earth's sur
face, according to the relative extension of the aqueous and
solid parts, the form and aspect of the land, and the direction
and elevation of mountain chains. A knowledge of the recip-
rocal action of air, sea, and land teaches us that great me-
teorological phenomena can not be comprehended when consid-
ered independently of geognostic relations. Meteorology, as
well as the geography of plants and animals, has only begun
10 make actual progress since the mutual dependence of the
phenomena to be investigated has been fully recognized. The
word climate has certainly special reference to the character
of the atmosphere, but this character is itself dependent on the
perpetually concurrent influences of the ocean, which is uni-
versally and deeply agitated by currents having a totally oppo-
site temperature, and of radiation from the dry land, which va-
ries greatly in form, elevation, color, and fertility, whether we
consider its bare, rocky portions, or those that are covered with
arborescent or herbaceous vegetation.

In the present condition of the surface of our planet, the area
of the solid is to that of the fluid parts as 1 : 2|ths (accord-
ing to Rigaud, as 100 : 270).* The islands form scarcely ^'ad
of the continental masses, which are so unequally divided that
they consist of three times more land in the northern than in
ihe southern hemisphere ; the latter being, therefore, pre-emi-
nently oceanic. From 40° south latitude to the Antarctic
pole the earth is almost entirely covered with water. The
fluid element predominates in like manner between the east-
ern shores of the Old and the western shores of the New Con-
tinent, being only interspersed with some few insular groups.
The learned hydrographer Fleurieu has very justly named this

* See Transactions of the Cambridge Philosophical Society, vcl. vi.
Pwt ii., 1837, p. 297. Other writers have given the ratio as lOff : 284

PHVaiuAL GEOGRAPHY. 289

vast oceanic basin, which, under the tropics, ex;tends over 145^
of longitude^ the Great Ocean, in contradistinction to all other
seas. The southern and western hemispheres (reckoning the
latter from the meridian of Teneriffe) are therefore more rich
in water than any other region of the whole earth.

These are the main points involved in the consideration of
the relative quantity of land and sea, a relation which exer-
cises so important an influence on the distribution of temper-
ature, the variations in atmospheric pressure, the direction
of the winds, and the quantity of moisture contained in the
air, with which the development of vegetation is so essentially
connected. When we consider that nearly three fourths ol
the upper surface of our planet are covered with water,* wo
shall be less surprised at the imperfect condition of meteorol-
ogy before the beginning of the present century, since it is only
during the subsequent period that numerous accurate observa-
tions on the temperature of the sea at different latitudes and
at different seasons have been made and numerically compared
together.

The horizontal configuration of continents in their general
relations of extension was already made a subject of intellectual
contemplation by the ancient Greeks. Conjectures were ad-
vanced regarding the maximum of the extension from west to
east, and Dicsearchus placed it, according to the testimony of
Agathemerus, in the latitude of Rhodes, in the direction of a
line passing from the Pillars of Hercules to Thine. This line,
which has been termed the parallel of the diaphragm of Di-
ccearcJius, is laid down with an astronomical accuracy of po-
sition, which, as I have stated in another work, is well worthy
of exciting surprise and admiration.t Strabo, who was proba-
bly influenced by Eratosthenes, appears to have been so firmly
convinced that this parallel of 36^ was the maximum of the
extension of the then existing world, that he supposed it had
some intimate connection with the form of the earth, and
therefore places under this line the continent whose existence

* In the Middle Ages, the opinion prevailed that the sea covered, ^my
one seventh of the surface of the globe, an opinion which Cardinal d'Ailly
(Imago Mundi, cap. 8) founded on the fourth apocryphal book of Esdras.
Columbus, Mrho derived a great portion of his cosmographical knowledge
from the cardinal's work, was much interested in upholding this idea
of the smallness of the sea, to which the misunderstood expression of
" the ocean stream" contributed not a little. See Humboldt, Examcn
Critique de VHist. de la GSographie, t. i., p. 186.

t Agathemerus, in Hudson, Geographi Minores, t, ii., p. 4. S^-a
Humboldt, Asie Centr., t i., p. 120-125.

Vol. 1.— N

290 COSMOS,

he divined in the northern hemisphere, between Theria and
the coasts of Thine. *"

As we have already remarked, one hemisphere of the earth
(whether we divide the sphere through the equator or through
the meridian of Teneriffe) has a much greater expansion of
elevated land than the opposite one : these two vast ocean-
girt tracts of land, which we term the eastern and western,
or the Old and New Continents, present, however, conjointly
with the most striking contrasts of configuration and position
of their axes, some similarities of form, especially with refer-
ence to the mutual relations of their opposite coasts. In the
eastern continent, the predominating direction — the position
of the major axis — inclines from east to west (or, more cor-
rectly speaking, from southwest to northeast), while in the
western continent it inclines from south to north (or, rather,
from south-southeast to north-northwest). Both terminate to
the north at a parallel coinciding nearly with that of 70°,
while they extend to the south in pyramidal points, having
submarine prolongations of islands and shoals. Such, for in-
stance, are the Archipelago of Tierra del Fuego, the Lagullas
Bank south of the Cape of Good Hope, and Van Diemen's
Land, separated from New Holland by Bass's Straits. North-
ern Asia extends to the above parallel at Cape Taimura, which,
according to Krusenstern, is 78° 16', while it falls below it
from the mouth of the Great Tschukotschja River eastward
to Behring's Straits, in the eastern extremity of Asia — Cook's
East Cape — which, according to Beechey, is only 66° 3'.t
The northern shore of the New Continent follows with toler-
able exactness the parallel of 70°, since the lands to the north
and south of Barrow's Strait, from Boothia Felix and Victoria
Land, are merely detached islands.

The pyramidal configuration of all the southern extremities
of continents belongs to the similitudines physicce in configu-
ratione mundi, to which Bacon already called attention in his
Novum Organon, and with which Reinhold Foster, one of
Cook's companions in his seq^nd voyage of circumnavigation,
connected some ingenious considerations. On looking eastward
from the meridian of Teneriffe, we perceive that the southern
extremities of the three continents, viz., Africa as the extreme

* Strabo, lib. i., p. 65, Casaub. See Humboldt, Examen Crit., t. i-
p. 152.

t On the mean latitude of the Northern Asiatic shores, and the tru'S
name of Cape Taimura (Cape Siewero-Wostotschnoi), and Cape North-
east (Schalagskoi Mys), see Humboldt, Asie Centrale, t. iii., p. 35, 37

PKTSICAL GEOGRAPHY. 291

of the Old World, Australia, and South America, successively
approach nearer toward the south pole. New Zealand, whose
length extends fully 12° of latitude, forms an intermediate
link between Australia and South America, likewise termina-
tinp[ in an island, New Leinster. It is also a remarkable cir-
cumstance that the greatest extension toward the south falls
in the Old Continent, under the same meridian in which the
extremest projection toward the north pole is manifested. This
will be perceived on comparing the Cape of Good Hope and
the Lagullas Bank with the North Cape of Europe, and the
peninsula of Malacca with Cape Taimura in Siberia.* We
know not whether the poles of the earth are surrounded by
land or by a sea of ice. Toward the north pole the parallel
of 82° 55' has been reached, but toward the south pole only
that of 78° 10'.

The pyramidal terminations of the great continents are vari
ously repeated on a smaller scale, not only in the Indian Ocean,
and in the peninsulas of Arabia, Hindostan, and Malacca, but
also, as was remarked by Eratosthenes and Polybius, in the
Mediterranean, where these writers had ingeniously compared
together the forms of the Iberian, Italian, and Hellenic penin-
sulas.! Europe, whose area is five times smaller than that
of Asia, may almost be regarded as a multifariously articulated
western peninsula of the more compact mass of the continent
of Asia, the climatic relations of the former being to those of
the latter as the peninsula of Brittany is to the rest of France. J
The influence exercised by the articulation and higher devel-
opment of the form of a continent on the moral and intellect-
ual condition of nations was remarked by Strabo,§ who extols

* Humboldt, Asie Centrale, t. i., p. 198-200. The southern point
of America, and the Archipelago which we call Terra del Fuego, lie in
the meridian of the northwestern part of Baffin's Bay, and of the great
polar land, whose limits have not as yet been ascertained, and which,
perhaps, belongs to West Greenland.

t Strabo, lib. ii., p. 92, 108, Casaub.

} Humboldt, Asie Centrale, t. iii., p. 25. As early as the year 1817,
in my w^ork De distributione Geographicd Plantarum, secundum coelt
temperiem, ei altitudinem Montium, I directed attention to the import
ant influence of compact and of deeply-articulated continents on climate
and human civilization, " Regiones vel per sinus lunatos in longa comua
porrecta?, angulosis littorum recessibus quasi membratim discerpta?, vel
spatia patentia in immensum, quorum littora nullis incisa angulis ambit
sine aufractu oceanus" (p. 81, 182). On the relations of the extent of
coast to the area of a continent (considered in some degree as a meas-
ure of the accessibility of the interior), see the inquiries in Berghaus,
Annalen der Erdkunde, bd. xii., 1835, s. 490, and Physikal. Atlas, 1839
No. iii , s. 69. $ Strabo, lib. ii., p. 92, 198, Casaub.

292 COSMOS.

the varied form of our small continent as a special advantage.
Africa* and South America, which manifest so great a resem-
blance in their configuration, are also the two continents that
exhibit the simplest littoral outlines. It is only the eastern
shores of Asia, which, broken as it were by the force of the
currents of the oceant [fractas ex cequore terras), exhibit a
richly-variegated configuration, peninsulas and contiguous isl-
ands alternating from the equator to 60° north latitude.

Our Atlantic Ocean presents all the indications of a valley.
It is as if a flow of eddying waters had been directed first to-
ward the northeast, then toward the northwest, and back
again to the northeast. The parallelism of the coasts north
of 10° south latitude, the projecting and receding angles, the
convexity of Brazil opposite to the Gulf of Guinea, that of
Africa under the same parallel, with the Gulf of the Antilles,
all favor this apparently speculative view-J In this Atlantic
valley, as is almost every where the case in the configuration
of large continental masses, coasts deeply indented, and rich
m islands, are situated opposite to those possessing a different
character. I long since drew attention to the geognostic im-
portance of entering into a comparison of the western coast of
Africa and of South America within the tropics. The deeply-
curved indentation of the African continent at Fernando Po,
4° 30' north latitude, is repeated on the coast of the Pacific
at 18° 15' south latitude, between the Valley of Arica and
the Morro de Juan Diaz, where the Peruvian coast suddenly
changes the direction from south to north which it had previ-
ously followed, and inclines to the northwest. This change

* Of Africa, Fliny says (v. 1), " Nee alia pars terrarum pauciores re-
cipit sinus." The small ludian peninsula on this side the Ganges pre-
sents, in its triangular outline, a third analogous form. In ancient
Greece there prevailed an opinion of the regular configuration of the
dry land. There were four gulfs or bays, among which the Persian
Gulf was placed in opposition to the Hyrcanian or Caspian Sea ( Arrian,
vii., 16; Plut., in vita Alexandri, cap. 44; Dionys. Perieg., v. 48 and
630, p. 11, 38, Bernh.). These four bays and the isthmuses were, ac-
cording to the optical fancies of Agesianax, supposed to be reflected in
the moon (Plut., de Facie in Orbem Lunce, p. 921, 19). Respecting the
terra quadrijida, or four divisions of the dry land, of which two lay
north and two south of the equator, see Macrobius, Comm. in Somnium
Scipionis, ii., 9. I have submitted this portion of the geography of the
ancients, regarding which great confusion prevails, to a new and care-
ful examination, in my Examen Crit. de VHist. de la Giogr., t. i., p.
119, 145, 180-185, as also in Asie Centr., t. ii., p. 172-178.

t Fleurieu, in Voyage de Marchand autour du Monde, t. iv., p. 38-42.

t Humboldt, in the Journal de Physique, liii., 1799, p. 33 ; and ReL
Hist., t. ii., p. 19; t. iii., p. 189, 198.

PHYSICAL GEOGRAPHY. 293

of direction extends in like manner to the chain of the Andes,
which is divided into two parallel branches, affecting not only
the littoral portions,* but even the eastern Cordilleras. In
the latter, civilization had its earliest seat in the South Amer-
ican plateaux, where the small Alpine lake of Titicaca bathes
the feet of the colossal mountains of Sorata and lUimani.
Further to the south, from Valdivia and Chiloe (40° to 42°
south latitude), through the Archipelago cle los Chonos to
Terra del Fuego, we find repeated that singular configuration
of fiords (a blending of narrow and deeply-indented bays),
which in the Northern hemisphere characterizes the western
shores of Norway and Scotland

These are the most general considerations suggested by the
study of the upper smface of our planet with reference to the
form of continents, and their expansion in a horizontal direc-
tion. We have collected facts and brought forward some
analogies of configuration in distant parts of the earth, but we
do not venture to regard them as fixed laws of form. When
the traveler on the declivity of an active volcano, as, for in-
stance, of Vesuvius, examines the frequent partial elevations
by which portions of the soil are often permanently upheaved
several feet above their former level, either immediately pre-
ceding or during the continuance of an eruption, thus forming
roof-like or flattened summits, he is taught how accidental
conditions in the expression of the force of subterranean va-
pors, and in the resistance to be overcome, may modify the
form and direction of the elevated portions. In this manner,
feeble perturbations in the equilibrium of the internal elastic
forces of our planet may have inclined them more to its north-
ern than to its southern direction, and caused the continent
in the eastern part of the globe to present a broad mass, whose
major axis is almost parallel with the equator, while in the
western and more oceanic part the southern extremity is ex-
tremely narrow.

Very little can be empirically determined regarding the
causal connection of the phenomena of the formation of con-
tinents, or of the analogies and contrasts presented by their

* Humboldt, in Poggendorf's Annalen der Physik, bd. xl., s. 171.
On the remarkable fiord formation at the southeast end of America, see
Darwin's Journal {Narrative of the Voyages of the Adventure and Bea-
gle, vol. iii.), 1839, p. 266. The parallelism of the two mountain chains
is maintained from 5^^ south to 5° north latitude. The change in the
direction of the coast at Arica appears to be in consequence of the al-
tered course of the fissure, above which the Cordillera of the Andes
has been upheaved.

294 COSMOS.

configuration. All that we know regarding this subject re«
solves itself into th.s one point, that the active cause is sub-
terranean ; that continents did not arise at once in the form
they now present, but were, as we have already observed, in-
creased by degrees by njeans of numerous oscillatory elevations
and depressions of the soil, or were formed by the fusion of
separate smaller continental masses. Their present form is,
therefore, the result of two causes, which have exercised a con-
secutive action the one on the other : the first is the expression
of subterranean force, whose direction we term accidental,
owing to our inabiUty to define it, from its removal from with-
in the sphere of our comprehension, while the second is derived
from forces acting on the surface, among which volcanic erup-
tions, the elevation of mountains, and currents of sea water
play the principal parts. How totally different would be the
condition of the temperature of the earth, and, consequently,
of the state of vegetation, husbandry, and human society, if
the major axis of the New Continent had the same direction
as that of the Old Continent ; if, for instance, the Cordilleras,
instead of having a southern direction, inclined from east to
west ; if there had been no radiating tropical continent, like
Africa, to the south of Europe ; and if the Mediterranean
which was once connected with the Caspian and Red Seas
and which has become so powerful a means of furthering the
intercommunication of nations, had never existed, or if it had
been elevated like the plains of Lombardy and Cyrene 1

The changes of the reciprocal relations of height between
the fluid and solid portions of the earth's surface (changes
which, at the same time, determine the outlines of continents,
and the greater or lesser submersion of low lands) are to be
ascribed to numerous unequally working causes. The most
powerful have incontestably been the force of elastic vapors
inclosed in the interior of the earth, the sudden change of tem
perature of certain dense strata,* the unequal secular loss e

* De la Beclie, Sections and Views illustrative of Geological Phenome-
na, 1830, tab. 40; Charles Babbage, Observations on the Temple of
Serapis at Pozzuoli, near Naples, and on certain Causes which may
produce Geological Cycles of great Extent, 1834. " If a stratum of sand-
stone five miles in thickness should have its temperature raised about
100*^, its surface would rise tvs^enty-five feet. Heated beds of claj
would, on the contrary, occasion a sinking of the ground by their con-
traction." See Bischof, Wdrmelehre des Innem unseres Erdkorpers, s.
303, concerning the calculations for the secular elevation of Sweden, on
the supposition of a rise by so small a quantity as 7° in a stratum of
about 155,000 feet in thickness, and heated to a state of fusion.

PHYSICAL GEOGRAPHY. 295

heat experienced by the crust and nucleus of the earth, occa-
sioning ridges in the sohd surface, local modifications of gravi-
tation,* and, as a consequence of these alterations, in the curv-
ature of a portion of the liquid element. According to the
views generally adopted by geognosists in the present day, and
which are supported by the observation of a series of well-
attested facts, no less than by analogy with the most import-
ant volcanic phenomena, it would appear that the elevation
of continents is actual, and not merely apparent or owing to
the configuration of the upper surface of the sea. The merit
of having advanced this view belongs to Leopold von Buch,
who first made his opinions known to the scientific world in
the narrative of his memorable Travels through Norway and
Sweden in 1806 and I807.t While the whole coast of
Sweden and Finland, from Solvitzborg, on the limits of North-
ern Scania, past Gefle to Tornea, and from Tornea to Abo,
experiences a gradual rise of four feet in a century, the south-
ern part of Sweden is, according to Neilson, undergoing a
simultaneous depression. $ The maximum of this elevating

* The opinion so implicitly entertained regarding the invariability of
the force of gravity at any given point of the earth's surface, has in
some degree been controverted by the gradual rise of large portions of
the earth's surface. See Bessel, Ueber Maas und Gewicht, in Schu-
macher's Jahrbuchfur 1840, s. 134.

t Th. ii. (1810), s. 389. See Hallstrom, in Kongl. Vetenskaps-Aca-
demiens Handlingar (Stockh.), 1823, p. 30; Lyell, in the Philos. Trans.
for 1835 ; Blom (Amtmann in Budskerud), Stat. Beschr. von Norwegen,
1843, 8. 89-1 16. If not before Von Buch's travels through Scandina\'ia,
at any rate before their publication, Playfair, in 1802, in his illustrations
of the Huttonian theory, § 393, and, according to Keilhau {Om Land-
jordens Stigning in Norge, in the Nyt Magazine fur Naturvidenska-
herne), and the Dane Jessen, even before the time of Playfair, had ex-
pressed the opinion that it was not the sea which was sinking, but the
solid land of Sweden which was rising. Their ideas, however, were
wholly unknown to our great geologist, and exerted no influence on
the [)rogress of physical geography. Jessen, in his work, Kongeriget
Norge fremstillet efter dels naturlige og borgerlige Tilstand, Kjobenh.,
1763, sought to explain the causes of the changes in the relative levels
of the land and sea, basing his views on the early calculations of Celsius,
Kalm, and Dalin. He broaches some confused ideas regarding the pos-
sibility of an internal growth of rocks, but finally declares himself in
favor of an upheaval of the land by earthquakes, " although," he ob-
serves, " no such rising was apparent immediately after the earthquake
of Egersund, yet the earthquake may have opened the way for other
causes producing such an etfect."

X See Berzelius, Jahrsbericht uber die Fortschritte der Physischen
Wiss., No. 18, s. 686. The islands of Saltholm, opposite to Copen
hagen, and Bjornholm, however, rise but very little — Bjornholm scarce-
ly one foot in a century. See Forchhammer, in Philos. Magazine, 3d
Series, vol. ii., p 309

296 COSMOS.

force appears to lie in the north of Lapland, and to diminish
gradually to the south toward Calmar and Solvitzborg. Lines
marking the ancient level of the sea in pre-historic times are
indicated throughout the whole of Norway,* from Cape Lin-
desnaes to the extremity of the North Cape, by banks of shells
identical with those of the present seas, and which have late-
ly been most accurately examined by Bravais during his Ion
winter sojourn at Bosekop. These banks lie nearly 650 feet
above the present mean level of the sea, and reappear, accord-
ing to Keilhau and Eugene Robert, in a north-northwest di-
rection on the coasts of Spitzbergen, opposite the North Cape.
Leopold von Buch, who was the first to draw attention to the
high banks of shells at Tromsoe (latitude 69° 40'), has, how-
ever, shown that the more ancient elevations on the North
Sea appertain to a different class of phenomena, from the
regular and gradual retrogressive elevations of the Swedish
shores in the Gulf of Bothnia. This latter phenomenon, which
is well attested by historical evidence, must not be confound-
ed with the changes in the level of the soil occasioned by
earthquakes, as on the shores of Chili and of Cutch, and
which have recently given occasion to similar observations in
other countries. It has been found that a perceptible sinking
resulting from a disturbance of the strata of" the upper surface
sometimes occurs, corresponding with an elevation elsewhere,
as, for instance, in West Greenland, according to Pingel and
Graah, in Dalmatia and in Scania.

Since it is highly probable that the oscillatory movements
of the soil, and the rising and sinking of the upper surface,
were more strongly marked in the early periods of our planet
than at present, we shall be less surprised to find in the inte-
rior of continents some few portions of the earth's surface ly-
ing below the general level, of existing seas. Instances of this
kind occur in the soda lakes described by General Andreossy,
the small bitter lakes in the narrow Isthmus of Suez, the
Caspian Sea, the Sea of Tiberias, and especially the Dead
Sea.t The level of the water in the two last-named seas is

* Keilhau, \nNyt Mag. fur Naturvid., 1832, bd. i., p. 105-254; bd.
ii., p. 57 ; Bravais, Sur les Lignes d^ancien Niveati de la Mer, 1843, p
15-40. See, also, Darwin, "on the Parallel Roads of Glen-Roy and
Lochaber," iu Philos. Trans, for 1839, p. 60.

t Humboldt, Asie Centrale, t. ii., p. 319-324; t. iii., p. 549-551
The depression of the Dead Sea has been successively determined by
the barometrical measurements of Count Bertou, by the more careful
ones of Russegger, and by the trigonometrical survey of Lieutenant Sy-
mond, oi the Royal Navy, who states that the difference of level be

PHYSICAL GEOGRAPHY. 291

666 and 1312 feet below the level of the Mediterranean. If
we could suddenly remove the alluvial soil which covers the
rocky strata in many parts of the earth's surface, we should
discover how great a portion of the rocky crust of the earth
was then below the present level of the sea. The periodic,
although irregularly alternating rise and fall of the water of
the Caspian Sea, of which I have myself observed evident
traces in the northern portions of its basin, appears to prove,=^
as do also the observations of Darwin on the coral seas,t that
without earthquakes, properly so called, the surface of the
earth is capable of the same gentle and progressive oscilla-
tions as those which must have prevailed so generally in the
earliest ages, when the surface of the hardening crust of the
earth was less compact than at present.

The phenomena to which we would here direct attention
remind us of the instability of the present order of things, and
of the changes to which the outlines and configuration of con-
tinents are probably still subject at long intervals of time.
That which may scarcely be perceptible in one generation,
accumulates during periods of time, whose duration is revealed
to us by the movement of remote heavenly bodies. The east-
ern coast of the Scandinavian peninsula has probably risen

tween the surface of the Dead Sea and the highest houses of Jaffa is
about 1605 feet. Mr. Alderson, who communicated this result to the
Geographical Society of London in a letter, of the contents of which 1
was informed by my friend, Captain Washington, was of opinion (Nov.
28, 1841) that the Dead Sea lay about 1400 feet under the level of the
Mediterranean. A more recent communication of Lieutenant Symond
(.Jameson's Edinburgh New Philosophical Journal, vol. xxxiv., 1843, p.
178) gives 1312 feet as the final result of two very accordant trigone
metx'ical operations.

* Sur la Mobility du fond de la Mer Caspienne, in my Asie Centr., t.
ii., p. 283-294. The Imperial Academy of Sciences of St. Petersburgh,
in 1830, at my request, charged the learned physicist Lenz to place
marks indicating the mean level of the sea, for definite epochs, in dif-
ferent places near Baku, in the peninsula of Abscheron. In the same
manner, in an appendix to the instructions given to Captain (now Sir
James C.) Ross for his Antarctic expedition, I urged the necessity of
causing marks to be cut in the rocks of the southern hemisphere, as
had already been done in Sweden and on the shores of the Caspian
Sea. Had this measure been adopted in the early voyages of Bougain-
ville and Cook, we should now know whether the secular relative
changes in the level of the seas and land are to be considered as a gen-
eral, or merely a local natural phenomenon, and whether a law of di
rection can be recognized in the points which have simultaneous ele-
vation or depression.

t On the elevation and depression of the bottom of the South Sea,
and the different areas of alternate movements, see Darwin's Journal^
p. 557, 561-566.

N2

298 COSMOS.

about 320 feet in the space of 8000 years; and in 12,000
years, if the movement be regular, parts of the bottom of the
sea which He nearest the shores, and are in the present day
covered by nearly fifty fathoms of water, will come to the
surface and constitute dry land. But Vviiat ai;e such intervals
of time compared to the length of the geognostic periods re-
vealed to us in the stratified series of formations, and in the
world of extinct and varying organisms ! We have hitherto
only considered the phenomena of elevation ; but the analo-
gies of observed facts lead us with equal justice to assume the
possibility of the depression of whole tracts of land. The
mean elevation of the non-mountainous parts of France
amounts to less than 480 feet. It would not, therefore, re-
quire any long period of time, compared with the old geog-
nostic periods, in which such great changes were brought
about in the interior of the earth, to effect the permanent
submersion of the northwestern part of Europe, and induce
essential alterations in its littoral relations.

The depression and elevation of the solid or fluid parts of
the earth — phenomena which are so opposite in their action
that the effect of elevation in one part is to produce an appar-
ent depression in another — are the causes of all the changes
which occur in the configuration of continents. In a work of
this general character, and in an impartial exposition of the
phenomena of nature, we must not overlook the possibility
of a diminution of the quantity of water, and a constant de-
pression of the level of seas. There can scarcely be a doubt
that, at the period when the temperature of the surface of the
earth was higher, when the waters were inclosed in larger
and deeper fissures, and when the atmosphere possessed a to-
tally different character from what it does at present, great
changes must have occurred in the level of seas, depending
upon the increase and decrease of the liquid parts of the
earth's surface. But in the actual condition of our planet,
there is no direct evidence of a real continuous increase or de-
crease of the sea, and we have no proof of any gradual change
in its level at certain definite points of observation, as indi-
cated by the mean range of the barometer. According to ex-
periments made by Daussy and Antonio Nobile, an increase
in the height of the barometer would in itself be attended by
a depression in the level of the sea. But as ihe mean press-
ure of the atmosphere at the level of the sea is not the same
at all latitudes, owing to meteorological causes depending upon
the direction of the wind and varying degrees of moisture, tho

PHYSICAL GEOGRAPHY. 299

oarometer alone can not afford a certain evidence of the gen-
sral change of level in the ocean. The remarkable fact that
some of the ports in the Mediterranean were repeatedly left
dry during several hours at the beginning of this century, ap-
pears to show that currents may, by changes occurring in
their direction and force, occasion a local retreat of the sea,
and a permanent drying of a small portion of the shore, with-
out being followed by any actual diminution of water,%or any
permanent depression of the ocean. We must, however, be
very cautious in applying the knowledge which we have late-
ly arrived at, regarding these involved phenomena, since we
might otherwise be led to ascribe to water, as the elder ele-
ment, what ought to be referred to the two other elements,
earth and air.

As the external configuration of continents, which we have
already described in their horizontal expansion, exercises, by
their variously-indented littoral outlines, a favorable influence
on climate, trade, and the progress of civilization, so likewise
does their internal articulation, or the vertical elevation of
the soil (chains of mountains and elevated plateaux), give rise
to equally important results. Whatever produces a poly-
morphic diversity of forms on the surface of our planetary
habitation — such as mountains, lakes, grassy savannas, or
even deserts encircled by a band of forests — impresses some
peculiar character on the social condition of the inhabitants.
Ridges of high land covered by snow impede intercourse ; but
a blending of low, discontinued mountain chains* and tracts
of valleys, as we see so happily presented in the west and
south of Europe, tends to the multiplication of meteorological
processes and the products of vegetation, and, from the variety
manifested in different kinds of cultivation in eadh district,
even under the same degree of latitude, gives rise to wants
that stimulate the activity of the inhabitants. Thus the aw-
ful revolutions, during which, by the action of the interior on
the crust of the earth, great mountain chains have been ele-
vated by the sudden upheaval of a portion of the oxydized
exterior of our planet, have served, after the establishment
of repose, and on the revival of organic life, to furnish a rich-
er and more beautiful variety of individual forms, and in a
great measure to remove from the earth that aspect of dreary

* Humboldt, Rel. Hist., t. iii., p. 232-234. See, also, the able re-
marks on the configuration of the earth, and the position of its lines
of elevation, in Albrechts von Roon, Grundzugen der Erd Volkei- und
etaatenkunde, Abth. i., 1837, s. 158, 270, 276.

300 COSMOS.

uni-formity which exercises so impoverishing an influence on
the physical and intellectual powers of mankind.

According to the grand views of Elie de Beaumont, we
must ascribe a relative age to each system of mountain chains*
on the supposition that their elevation must necessarily have
occurred between the period of the deposition of the vertical-
ly elevated strata and that of the horizontally inclined strata
running at the base of the mountains. The ridges of the
Earth's crust— elevations of strata which are of the same ge-
ognostic age — appear, moreover, to follow one common direc-
tion. The line of strike of the horizontal strata is not always
parallel with the axis of the chain, but intersects it, so that,
according to my views,! the phenomenon of elevation of the
strata, which is even found to be repeated in the neighboring
plains, must be more ancient than the elevation of the chain.
The main direction of the whole continent of Europe (from
southwest to northeast) is opposite to that of the great fissures
which pass from northwest to southeast, from the mouths of
the Rhine and Elbe, through the Adriatic and Red Seas, and
through the mountain system of Putschi-Koh in Luristan, to-
ward the Persian Gulf and the Indian Ocean. This almost
rectangular intersection of geodesic lines exercises an import-
ant influence on the commercial relations of Europe, Asia,
and the northwest of Africa, and on the progress of civilization
on the formerly more flourishing shores of the Mediterranean .|

Since grand and lofty mountain chains so strongly excite
our imagination by the evidence they afTord of great terres-
trial revolutions, and when considered as the boundaries of
climates, as lines of separation for waters, or as the site of a
different form of vegetation, it is the more necessary to de-
■ raonstrate, by a correct numerical estimation of their volume,
how small is the quantity of their elevated mass when com-
pared with the area of the adjacent continents. The mass
of the Pyrenees, lor instance, the mean elevation of whose
summits, and the area] quantity of whose base have been as-
certained by accurate measurements, would, if scattered over

* Leop. von Bucli, Ueberdie Geognosiischen Systeme von Deutschland,
in his Geogn. Brief en an Alexander von Humboldt, 1824, s. 265-271;
Elie de Beaumont, Recherches sur les Revolutions de la Surface du Globe,
18-?9, p. 297-307.

+ Humboldt, Asie Centrale, t. i., p. 277-283. See, also, ray Essai
sur le Gisement des Roches, 1822, p. 57, and Relat. Hist., t. iii., p.
244-250.

% Asie Centrale, t. i., p. 284, 286 The Adriatic Sea likewise follow*
a direction from S.E. to N.W.

PHYSICAL GEOGRAIHY. 30l

the surface of France, only raise its mean level about 115
feet. The mass of the eastern and western Alps would in
like manner only increase the height of Europe about 21^
feet above its present level. I have found by a laborious in-
vestigation,* which, from its nature, can only give a maximum
limit, that the center of gravity of the volume of the land
raised above the present level of the sea in Europe and North
America is respectively situated at an elevation of 671 and
748 feet, while it is at 1132 and 1152 feet in Asia and South
America. These numbers show the low level of northern
regions. In Asia the vast steppes of Siberia are compensated
for by the great elevations of the land (between the Himalaya,^
the North Thibetian chain of Kuen-lun, and the Celestial
Mountains), from 28° 30' to 40° north latitude. We may,
to a certain extent, trace in these numbers the portions of the
Earth in which the Plutonic forces were most intensely mani-
fested in the interior by the upheaval of continental masses.

There are no reasons why these Plutonic forces may not,
in future ages, add new mountain systems to those which Elie
de Beaumont has shown to be of such different ages, and in-
clined in such different directions. Why should the crust of
the Earth have lost its property of being elevated in ridges ?
The recently-elevated mountain systems of the Alps and the
Cordilleras exhibit in Mont Blanc and Monte Rosa, in Sorata,
lUimani, and Chimborazo, colossal elevations which do not
favor the assumption of a decrease in the intensity of the sub-
terranean forces. All geognostic phenomena indicate the
periodic alternation of activity and repose ;t but the quiet
we now enjoy is only apparent. The tremblings which still
agitate the surface under all latitudes, and in every species of
rock, the elevation of Sweden, the appearance of new islands
of eruption, are all conclusive as to the unquiet condition of
our planet.

* De la hauteur Moyenne des Continents, in my Asie Centrale, t. i., p
82-90, 165-189. The results which I have obtained are to be regard-
ed as the extreme value (nombres-limiies). Laplace's estimate of the
mean height of continents at 3280 feet is, at least three times too high.
The immortal author of the Mecanique Celeste (t. v., p. 14) was led to
this conclusion by hypothetical views as to the mean depth of the sea
I have shown {Asie Centr., t. i., p. 93) that the old Alexandrian math
ematicians, on the testimony of Plutarch {in yEmilio Paulo, cap. 15),
believed this depth to depend on the height of the mountains. The
height of the center of gravity of the volume of the continental masses
is probably subject to slight variations in the course of many centuries

t Zweiter Geologischer Brief von Elie de Beaumont an Alexander von.
Humboldt, in Poggendorf's Annalen, bd. xxv., s. l-TiS

302 COSMOS.

The two envelopes of the solid surface of our planet — the
Hquid and the aeriform — exhibit, owing to the mobility of
their particles, their currents, and their atmospheric relations,
many analogies combined with the contrasts which arise from
the great difference in the condition of their aggregation and
elasticity. The depths of ocean and of air are alike unknown
to us. At some few places under the tropics no bottom has
been found with soundings of 276,000 feet (or more than four
miles), while in the air, if, according to Wollaston, we may
assume that it has a limit from which waves of sound may
be reverberated, the phenomenon of twilight would incline
^us to assume a height at least nine times as great.* The
aerial ocean rests partly on the solid earth, whose mountain
chains and elevated plateaux rise, as we have already seen,
like green wooded shoals, and partly on the sea, whose surface
forms a moving base, on which rest the lower, denser, and
more saturated strata of air.

Proceeding upward and downward from the common limit of
the aerial and liquid oceans, we find that the strata of air
and water are subject to determinate laws of decrease of tem-
perature. This decrease is much less rapid in the air than
in the sea, which has a tendency under all latitudes to main-
tain its temperature in the strata of water most contiguous to
the atmosphere, owing to the sinking of the heavier and more
cooled particles. A large series of the most carefully con-
ducted observations on temperature shows us that in the or-
dinary and mean condition of its surface, the ocean from the
equator to the forty-eighth degree of north and south latitude
is somewhat warmer than the adjacent strata of air.t Owing
to this decrease of temperature at increasing depths, fishes and
other inhabitants of the sea, the nature of whose digestive and
respiratory organs fits them for living in deep water, may even,
under the tropics, find the low degree of temperature and the
coolness of climate characteristic of more temperate and more
northern latitudes. This circumstance, which is analogous
to the prevalence of a mild and even cold air on the elevated
plains of the torrid zone, exercises a special influence on the
migration and geographical distribution of many marine ani-
mals. Moreover, the depths at which fishes live, modify, by
the increase of pressure, their cutaneous respiration, and the

* [See Wilson's Paper, On Wollaston'' s Argument from the Limitation
»f the Atmos'phere as to the finite Divisibility of Matter. — Trans, of the
Royal Society of Edinb., veil, xvi., p. 1, 1845.] — Tr.

t Humboldt, Relation Hist, t. iii., chap, xxix., p. 514-530.

PHYSICAL GEOGRAPHY. 303

oxygenous and nitrogenous contents of their swimming blad-
deis.

As fresh and salt water do not attain the maximum of
their density at the same degree of temperature, and as the
saltness of the sea lowers the thermometrical degree corre-
sponding to this point, we can understand how the watei
drawn from great depths of the sea during the voyages of
Kotzebue and Dupetit-Thouars could have been found to have
only the temperature of 37° and 36'^-5. This icy temperature
of sea water, which is likewise manifested at the depths of
tropical seas, first led to a study of the lower polar currents,
which move from both poles toward the equator. Without
these submarine currents, the tropical seas at those depths
could only have a temperature equal to the local maximum
of cold possessed by the falling particles of water at the radi •
ating and cooled surface of the tropical sea. In the Mediter-
ranean, the cause of the absence of such a refrigeration of tht
lower strata is ingeniously explained by Arago, on the as-
sumption that the entrance of the deeper polar currents into
the Straits of Gibraltar, where the water at the surface flows
in from the Atlantic Ocean from west to east, is hindered by
the submarine counter-currents which move from east to
west, from the Mediterranean into the Atlantic.

The ocean, which acts as a general equalizer and moder-
ator of climates, exhibits a most remarkable uniformity and
constancy of temperature, especially between 10° north and
10° south latitude,* over spaces of many thousands of square
miles, at a distance from land where it is not penetrated by
currents of cold and heated water. It has, therefore, been
justly observed, that an exact and long-continued investiga-
tion of these thermic relations of the tropical seas might most
easily afford a solution to the great and much-contested prob-
lem of the permanence of cHmates and terrestrial tempera
tures.f Great changes in the luminous disk of the sun would,

* See the series of observations made by me in the South Sea, from
QO 5' to 13^ 16' N. lat., in my Asie Centrale, t. iii., p. 234.

|- " We might (by means of the temperature of the ocean under the
tropics) enter into the consideration of a question which has hitherto
remained unanswered, namely, that of the constancy of terrestrial tern
peratures, without taking into account the very circumscribed local
influences arising from the diminution of wood in the plains and on
mountains, and the drying up of lakes and marshes. Each age might
easily transmit to the succeeding one some few data, which would per-
haps lurnish the most simple, exact, and direct means of deciding whetn-
er the sun, which is almost i\.f) sole and exclusive source of the heat of

304 COSMOS.

if they were of long duration, be reflected with more certainty
in the mean temperature of the sea than in that of the solid
land.

The zones, at which occur the maxima of the oceanic tem-
perature and of the density -(the saline contents) of its waters,
do not correspond with the equator. The two maxima are
separated from one another, and the waters of the highest tem-
perature appear to form two nearly parallel lines north and
south of the geographical equator. Lenz, in his voyage of
circumnavigation, found in the Pacific the maxima of density
in 22^ north and 17° south latitude, while its minimum was
situated a few degrees to the south of the equator. In the
region of calms the solar heat can exercise but little influence
on evaporation, because the stratum of air impregnated with
saUne aqueous vapor, which rests on the surface of the sea,
remains still and unchanged.

The surface of all connected seas must be considered as
having a general perfectly equal level with respect to theii
mean elevation. Local causes (probably prevaiUng winds and
currents) may, however, produce permanent, although trifling
changes in the level of some deeply-indented bays, as, for in-
stance, the Red Sea. The highest level of the water at the
Isthmus of Suez is at different hours of the day from 24 to
30 feet above that of the Mediterranean. The form of the
Straits of Bab-el-Mandeb, through which the waters appear
to find an easier ingress than egress, seems to contribute to
this remarkable phenomenon, which was known to the an-
cients.* The admirable geodetic operations of Coraboeuf and
Delcrois show that no perceptible difference of level exists be-
tween the upper surfaces of the Atlantic and the Mediterra-
nean, along the chain of the Pyrenees, or between the coasts
of northern Holland and Marseilles.!

our planet, changes its physical constitution and splendor, like the great
er number of the stars, or whether, on the contrary, that luminary has
attained to a permanent condition." — Arago, in the Comptes Rendu*
des Sianceg de V Acad, des Sciences, t. xi., Part ii., p. 309.

* Humboldt, Asie Centrale, t. ii., p. 321, 327.

t See the numerical results in p. 328-333 of the volume just named.
From the geodesical levelings which, at my request, my friend General
Bolivar caused to be taken by Lloyd and Falmarc, in the years 1828
and 1829, it was ascertained that the level of the Pacific is at the ut-
most 3i feet higher than that of the Caribbean Sea; and even that at
different hours of the day each of the seas is in turn the higher, accord-
ing to their respective hours of flood and ebb. If we reflect that in a
distance of 64 miles, comprising 933 stations of observation, an error of
three feet would be very apt to occur we may say that in these new

PHYSICAL GEDGRAPHY. 305

Disturbances of equilibrium and consequent movements of
(he waters are partly irregular and transitory, dependent upon
winds, and producing waves which sometimes, at a distance
from the shore and during a storm, rise to a height of more
than 35 feet ; partly regular and periodic, occasioned by the
position and attraction of the sun and moon, as the ebb and
flow of the tides ; and partly permanent, although less in
tense, occurring as oceanic currents. The phenomena of
tides, which prevail in all seas (with the exception of the
smaller ones that are completely closed in, and where the ebb-
ing and flowing waves are scarcely or not at all perceptible),
have been perfectly explained by the Newtonian doctrine,
and thus brought " within the domain of necessary facts."
Each of these periodically-recurring oscillations of the waters
of the sea ha? a duration of somewhat more than half a day.
Although in the open sea they scarcely attain an elevation of
a few feet, they often rise considerably higher where the waves
are opposed by the configuration of the shores, as, for instance,
at St. Malo and in Nova Scotia, where they reach the re-
spective elevations of 50 feet, and of 65 to 70 feet. " It has
been shown by the analysis of the great geometrician La-
place, that, supposing the depth to be wholly inconsiderable
when compared with the radius of the earth, the stability of
the equilibrium of the sea requires that the density of its fluid
should be less than that of the earth ; and, as we have already
seen, the earth's density is in fact five times greater than
that of water. The elevated parts of the land can not there-
fore be overflowed, nor can the remains of marine animals
found on the summits of mountains have been conveyed to
those localities by any previous high tides."* It is no slight

operations we have further confirmation of the equilibrium of the wa-
ters which coinmunicate round Cape Horn. (Arago, in the Annuaire
du Bureau des Longitudes pour 1831, p. 319.) I had inferred, from
barometrical observations instituted in 1799 and 1804, that if there were
any difference between the level of the Pacific and the Atlantic (Ca-
ribbean Sea), it could not exceed three meters (nine feet three inches).
See my Relat. Hist., t. iii., p. 555-557, and Annates de Chimie, t. i.,
p. 55-64. The measurements, which appear to establish an excess of
height for the waters of the Gulf of Mexico, and for those of the noi-th-
ern part of the Adriatic Sea, obtained by combining the trigonometrical
operations of Delcrois and Choppin with those of the Swiss and Aus-
*rian engineers, are open to many doubts. Notwithstanding the form
of the Adriatic, it is improbable that the level of its waters iu its north-
ern portion should be 28 feet higher than that of tlie Mediterranean at
Marseilles, and 25 feet higher than the level of the Atlantic Ocean.
See my Asie Centrale, t. ii., p. 332.
* Bessel, Ueber Fluth niid Ebbe,in Schumacher's JaAriwc^, 1838, s. 225

306 C0SM3S.

evidence of tnc importance of analysis, which is too often re-
garded with contempt amonfr the unscientific, that Laplace's
perfect theory of tides has enabled us, in our astronomical
ephemerides, to predict the height of spring-tides at the peri-
ods of new and full moon, and thus put the inhabitants of the
sea-shore on their guard against the increased danger attend -
ng these lunar revolutions.

Oceanic currents, which exercise so important an influence
on the intercourse of nations and on the climatic relations of
adjacent coasts, depend conjointly upon various causes, differ-
ing alike in nature and importance. Among these we may
reckon the periods at which tides occur in their progress round
the earth ; the duration and intensity of prevailing winds ;
the modifications of density and specific gravity which the par-
ticles of water undergo in consequence of difTerences in the
temperature and in the relative quantity of saline contents at
difTerent latitudes and depths ;* and, lastly, the horary varia-
tions of the atmospheric pressure, successively propagated from
east to west, and occurring with such regularity in the trop-
ics. These currents present a remarkable spectacle ; like riv-
ers of uniform breadth, they cross the sea in difTerent direc-
tions, while the adjacent strata of water, which remain un-
disturbed, form, as it were, the banks of these moving streams.
This difTerence between the moving waters and those at rest
is most strikingly manifested where long lines of sea- weed,
borne onward by the current, enable us to estimate its veloc-
ity. In the lower strata of the atmosphere, we may some-
times, during a storm, observe similar phenomena in the lim-
ited aerial current, which is indicated by a narrow line of
trees, which are often found to be overthrown in the midst of
a dense wood.

The general movement of the sea from east to west be-

* The relative density of the particles of water depends simultane-
ously on the temperature and on the amount of the saline contents — a
circumstance that is not sufficiently borne in mind in considering the
cause of currents. The submarine current, which brings the cold po-
lar water to the equatorial regions, w^ould follow an exactly opposite
course, that is to say, from the equator toward the poles, if the ditTer-
ence in saline contents were alone concerned. In this view, the geo-
graphical distribution of temperature and of density in the water of
the ocean, under the different zones of latitude and longitude, is of
great importance. The numerous observations of Lenz (Poggendorf' a
Annalen, bd. xx., 1830, s, 129), and those of Captain Beechey, collect-
ed in his Voyage to the acijic, vol. ii., p. 727, deserve particular at-
tention. See Htmiboldt, Relat. Hist,, t. i., p. 74, and Asie Centrale,
t. iii., p. 356.

PHYSICAL GEOGRAPHY. ' 307

tween the tropins (termed the equatorial or rotation current)
is considered to be owing to the propagation of tides and to
the trade winds. Its direction is changed by the resistance
it experiences from the prominent eastern shores of continents.
The results recently obtained by Daussy regarding the veloo
ity of this current, estimated from observations made on the
distances traversed by bottles that had purposely been thrown
into the sea, agree within one eighteenth with the velocity of
motion (10 French nautical miles, 952 toises each, in 24 hours)
which I had found from a comparison with earlier experi-
ments.'^ Christoplier Columbus, during his third voyage,
when he was seeking to enter the tropics in the meridian of
Tenerifie, wrote in his journal as follows :t " I regard it as
proved that the waters of the sea move from east to west, as
do the heavens {las aguas van con los cielos), that is to say,
like the apparent motion of the sun, moon, and stars."

The narrow currents, or true oceanic rivers which traverse
the sea, bring warm water into higher and cold water into
lower latitudes. To the first class belongs the celebrated
Gulf Stream,^ which was known to Anghiera,§ and more
especially to Sir Humphrey Gilbert in the sixteenth century.
Its first impulse and origin is to be sought to the south of
the Cape of Good Hope ; after a long circuit it pours itself
from the Caribbean Sea and the Mexican Gulf through the
Straits of the Bahamas, and, following a course from south-
southwest to north-northeast, continues to recede from the
shores of the United States, until, further deflected to the
eastward by the Banks of Newfoundland, it approaches the
European coasts, frequently throwing a quantity of tropical
seeds {Mi^nosa scandens, Guilandina honduc^ Dolichos urens)
on the shores of Ireland, the Hebrides, and Norway. The
northeastern prolongation tends to mitigate the cold of the
ocean, and to ameliorate the climate on the most northern ex-
tremity of Scandinavia. At the point where the Gulf Stream

* Humboldt, Relat. Hist,, t. i., p. 64 ; Nouvelles Annates des Voyages
1839, p. 255.

t Humboldt, Examen Crit. de VHist. de la Giogr., t. iii., p. 100.
Columbus adds shortly after (Navarrete, Coleccion de los Viages y De-
gcubrimientos de los Espanoles, t. i., p. 260), that the movement ia
strongest in the Caribbean Sea. In fact, Rennell terms this region,
" not a current, but a sea in motion" {Investigation of Currents, p. 23).

X Humboldt, Examen Critique, t. ii., p. 250; Relat. Hist., t. i., p.
66-74.

$ Petrus Martyr de Anghiera, De Rebus Oceanicis et Orbe Novo,
Bas., 152'3, Dec. iii., lib. vi., p. 57. See Humboldt, Examen Critique
%. ii., p. :i .4-257, an(/ t. iii., p. 108.

308 COSMOS.

is deflected from the Banks of Newfoundland towaid the east,
it sends off' branches to the south near the Azores.* This is
the situation of the Sargasso Sea, or that great bank of weeds
which so vividly occupied the imagination of Christopher Co-
lumbus, and which Oviedo calls the sea-weed meadows {Pra-
derias de yerva). A host of small marine animals inhabits
these gently-moved and evergreen masses of Fucus natans^
one of the most generally distributed of the social plants of
ihe sea.

The counterpart of this current (which in the Atlantic
Ocean, between Africa, America, and Europe, belongs almost
exclusively to the northern hemisphere) is to be found in the
South Pacific, where a current prevails, the effect of whose low
temperature on the climate of the adjacent shores I had an
opportunity of observing in the autumn of 1802. It brings
the cold waters of the high southern latitudes to the coast of
Chih, follows the shores of this continent and of Peru, first from
south to north, and is then deffected from the Bay of Arica on-
ward from south-southeast to north-northwest. At certain
seasons of the year the temperature of this cold oceanic cur-
rent is, in the tropics, only 60^, while the undisturbed adjacent
water exhibits a temperature of 81*^-5 and 83^-7. On that
part of the shore of South America south of Payta, which in-
clines furthest westward, the current is suddenly deflected in
the same direction from the shore, turning so sharply to the
west that a ship sailing northward passes suddenly from cold
into warm water.

It is not known to what depth cold and warm oceanic cur-
rents propagate their motion ; but the deflection experienced
by the South African current, from the Lagullas Bank, which
is fully from 70 to 80 fathoms deep, would seem to imply the
existence of a far-extending propagation. Sand banks and
shoals lying beyond the line of these currents may, as was first
discovered by the admirable Benjamin Franklin, be recognized
by the coldness of the water over them. This depression of
the temperature appears to me to depend upon the fact that,
by the propagation of the motion of the sea, deep waters rise
to the margin of the banks and mix with the upper strata.
My lamented friend. Sir Humphrey Davy, ascribed this phe-
nomenon (the knowledge of which is often of great practical
utihty in securing the safety of the navigator) to the descent
of the particles of water that had been cooled by nocturnal i'a-

* Humboldt, Examen Crit., t. ili., p. G4-109

PHYSICAL GEOGBAPHY. 309

diatlon, and -yyhicli remain nearer to the surface, owing to the
hinderance placed in the way of their greater descent by the
intervention of sand-banks. By his observations Frankhn may
be said to have converted the thermometer into a sounding
line. Mists are frequently found to rest over these depths, ow-
ing to the condensation of the vapor of the atmosphere by the
cooled waters. I have seen such mists in the south of Jamai-
ca, and also in the Pacific, defining with sharpness and clear-
ness the form of the shoals below them, appearing to the eye
as the aerial reflection of the bottom of the sea. A still more
striking efiect of the cooling produced by shoals is manifested
in the higher strata of air, in a somewhat analogous manner
to that observed in the case of flat coral reefs, or sand islands.
In the open sea, far from the land, and when the air is calm,
clouds are often observed to rest over the spots where shoals
are situated, and their bearing may then be taken by the com-
pass in the same manner as that of a high mountain or isola-
ted peak.

Although the surface of the ocean is less rich in living forms
than that of continents, it is not improbable that, on a further
investigation of its depths, its interior may be found to possess
a greater richness of organic life than any other portion of our
planet. Charles Darwin, in the agreeable narrative of his ex-
tensive voyages, justly remarks that our forests do not conceal
so many animals as the low woody regions of the ocean, where
the sea- weed, rooted to the bottom of the shoals, and the sev
ered branches of fuci, loosened by the force of the waves and
currents, and swimming free, unfold their delicate foliage, up-
borne by air-cells.* The application of the microscope increas-
es, in the most striking manner, our impression of the rich lux-
uriance of animal life in the ocean, and reveals to the aston-
ished senses a consciousness of the universality of life. In the
oceanic depths, far exceeding the height of our loftiest mount-
ain chains, every stratum of water is animated with polygas-
tric sea- worms, Cyclidiae, and Ophrydina3. The waters swarm
with countless hosts of small luminiferous animalcules, Mam-
maria(of the order of Acalephse), Crustacea, Peridinea, and cir-
cling Nereides, which, when attracted to the surface by peculiar
meteorological conditions, convert every v/ave into a foaming
band of flashing light.

* [See Structure and Distribution of Coral Reefs,hy Charles Darwin,
London, 1842. Also, Narrative of the Surveying Voyage of H.M.S.
" Fly,^^ in the Eastern Archipelago, during the Years 1842-184G, by J
B. Jukes, Naturalist to the expedition, 1847.] — Tr.

310 COSMOS.

The abundance of these marine animalcules; and the anmia*
matter yielded by their rapid decomposition, are so vast that
the sea water itself becomes a nutrient fluid to many of tho
larger animals. However much this richness in animated
forms, and this multitude of the most various and highly-de-
veloped microscopic organisms may agreeably excite the fancy,
the imagination is even more seriously, and, I might say, more
solemnly moved by the impression of boundlessness and im-
measurability, which are presented to the mind by every sea
voyage. All who possess an ordinary degree of mental activi-
ty, and delight to create to themselves an inner world of
thought, must be penetrated with the sublime image of the
infinite when gazing around them on the vast and boundless
sea, when involuntarily the glance is attracted to the distant
horizon, where air and water blend together, and the stars con-
tinually rise and set before.the eyes of the mariner. This con-
templation of the eternal play of the elements is clouded, like
every human joy, by a touch of sadness and of longing.

A peculiar predilection for the sea, and a grateful remem-
brance of the impression which it has excited in my mind, when
I have seen it in the tropics in the calm of nocturnal rest, oi
in the fury of the tempest, have alone induced me to speak of
the individual enjoyment afforded by its aspect before I en-
tered upon the consideration of the favorable influence which
the proximity of the ocean has incontrovertibly exercised on
the cultivation of the intellect and character of many nations,
by the multiplication of those bands which ought to encircle
the whole of humanity, by affording additional means of arriv-
ing at a knowledge of the configuration of the earth, and fur-
thering the advancement of astronomy, and of all other math-
ematical and physical sciences. A portion of this influence
was at first limited to the Mediterranean and the shores of
southwestern Africa, but from the sixteenth century it has
widely spread, extending to nations who live at a distance
from the sea, in the interior of continents. Since Columbus
was sent to " unchain the ocean"* (as the unknown voice
whispered to him in a dream when he lay on a sick-bed near

* The voice addressed him in these words, " Maravillosamente Dies
hizo sonar tu nombre en la tiei-ra ; de los atamientos de la mar Oceana,
que estaban cerrados con cadenas tan f'uertes, te dio las Haves" — " God
will cause thy name to be wonderfully resounded through the earth,
and give thee the keys of the gates of the ocean, which are closed with
Btrong chains." The dream of Columbus is related in the letter to the
Catholic monarchs of July the 7th, 1503. (Humboldt, Examen Critiqvf,.
t iii. p. 234.)

METEOROLOGY. 311

the River Belem), man has ever boldly ventured onward to-
ward the discovery of unknown regions.

The second external and general covering of our planet, the
aerial ocean, in the lower strata, and on the shoals of which
we live, presents six classes of natural phenomena, which man-
ifest the most intimate connection with one another. They
are dependent on the chemical composition of the atmosphere,
the variations in its transparency, polarization, and color, its
density or pressure, its temperature and humidity, and its elec-
tricity. The air contains in oxygen the first element of phys-
ical animal life, and, besides this benefit, it possesses another,
which may be said to be of a nearly equally high character,
namely, that of conveying sound ; a faculty by which it like-
wise becomes the conveyer of speech and the means of com-
municating thought, and, consequently, of maintaining social
intercourse. If the Earth were deprived of an atmosphere, as
we suppose our moon to be, it would present itself to our im-
agination as a soundless desert.

The relative quantities of the substances composing the
strata of air accessible to us have, since the beginning of thd
nineteenth century, become the object of investigations, in
which Gay-Lussac and myself have taken an active part ; it
is, however, only very recently that the admirable labors of
Dumas and Boussingault have, by new and more accurate
methods, brought the chemical analysis of the atmosphere to
a high degree of perfection. According to this analysis, a
volume of dry air contains 20*8 of oxygen and 79"2 of nitro-
gen, besides from two to five thousandth parts of carbonic
acid gas, a still smaller quantity of carbureted hydrogen gas,*
aifcd, according to the important experiments of Saussure and
Liebig, traces of ammoniacal vapors,! from which plants de-
rive their nitrogenous contents. Some observations of Lewy
render it probable that the quantity of oxygen varies percep'

* Boussingault, Recherches sur la Composition de V Atmosphere, ia the
Annates de Chimie et de Physique, t. Ivii., 1834, p. 171-173; and Ixxi.
1839, p. 116. According to Boussingault and Lewy, the proportion of
carbonic acid in the atmosphere at Audilly, at a distance, therefore, from
the exhalations of a city, varied only between 0-00028 and 0-00031 in
volume.

+ Liebig, in his important work, entitled Die Organische Chemie in
ihrer Anwendung auf Agricultur und Physiologic, 1840, s. 62-72. On
the influence of atmospheric electricity in the production of nitrate of
ammonia, which, coming into contact with carbonate of lime, is changed
into carbonate of ammonia, see Boussingault's Economie Rurale con»
ndirie dans ses Rapports avec la Chimie et la Mitiorologie, 1844, t. ii..
p. 247, 267, and t. i., p. 84.

•^12 C08M0S.

tibly, although but slightly, <iver the sea and in the interioi
of continents, according to local conditions or to the seasons of
the year. We may easily conceive that changes in the oxy-
gen held in solution in the sea, produced by microscopic an-
imal organisms, may be attended by alterations in the strata
of air in immediate contact with it.* The air which Martins
collected at Faulhorn at an elevation of 8767 feet, contained
as much oxygen as the air at Paris. t

The admixture of carbonate of ammonia in the atmosphere
may probably be considered as older than the existence of or
ganic beings on the surface of the earth. The sources from
which carbonic acid$ may be yielded to the atmosphere are
most numerous. In the first place we would mention the res-
piration of animals, who receive the carbon which they inhale
Irom vegetable food, while vegetables receive it from the at-
mosphere ; in the next place, carbon is supplied from the in-
terior of the earth in the vicinity of exhausted volcanoes and
thermal springs, from the decomposition of a small quantity of
carbureted hydrogen gas in the atmosphere, and from the elec-
tric discharges of clouds, which are of such frequent occurrence
within the tropics. Besides these substances, which we have
considered as appertaining to the atmosphere at all heights
that are accessible to us, there are others accidentally mixed
with them, especially near the ground, which sometimes, in
the form of miasmatic and gaseous contagia, exercise a noxious
influence on animal organization. Their chemical nature has
not yet been ascertained by direct analysis ; but, from the con-
sideration of the processes of decay which are perpetually go-
ing on in the animal and vegetable substances with which the
surface of our planet is covered, and judging from analogies
deduced from the domain of pathology, we are led to infer the
existence of such noxious local admixtures. Ammoniacal and
other nitrogenous vapors, sulphureted hydrogen gas, and com-
pounds analogous^to the polybasic ternary and quaternary com-
binations of the vegetable kingdom, may produce miasmata. «

* Lewy, in the Comptes Rendus de V Acad, des Sciences, t. xvii.. Part
ii., p. 235-248.

t Dumas, in the Annales de Chimie, 3e S6rie, t. iii., 1841, p. 257.

X In this enumeration, the exhalation of carbonic acid by plants dur-
ing the night, while they inhale oxygen, is not taken into account, be-
cause the increase of carbonic acid from this source is amply counter-
balanced by the respiratory process of plants during the day. See Bous-
singault's Econ. Rurale, t. i., p. 53-68, and lAeh\^^& Organische Chemie,
8. 16. 21.

<V Gay-Lussac. in Annales de Chimie, t. liii., p. 120; Payen, M4m. snt

METEOROLOGY 3l<J

which, under various forms, may generate ague and typhus
fever (not by any means exclusively on wet, marshy ground,
or on coasts covered by putrescent moUusca, and low bushes
of Rhizophora mangle and Avicennia). Fogs, which have
a peculiar smell at some seasons of the year, remind us of
these accidental admixtures in the lower strata of the atmos-
phere. Winds and currents of air caused by the heating of
the ground even carry up to a considerable elevation solid
substances reduced to a fine powder. The dust which dark-
ens the air for an extended area, and falls on the Cape Verd
Islands, to which Darwin has drawn attention, contains, ac-
cording to Ehrenberg's discovery, a host of silicious-shelled in
fusoria

As prmcipai features of a general descriptive picture of tlie
atmosphere, we may enumerate :

1 . Variations of atmospheric pressure : to which belong
the horary oscillations, occurring with such regularity in the
tropics, where they produce a kind of ebb and flow in the at-
mosphere, which can not be ascribed to the attraction of the
moon,* and which differs so considerably according to geo-
graphical latitude, the seasons of the year, and the elevation
above the level of the sea.

2. Climatic distribution of heat, which depends on the
relative position of the transparent and opaque masses (the
fluid and solid parts of the surface of the earth), and on the
hypsometrical configuration of continents ; relations which de-
termine the geographical position and curvature of the iso-
thermal lines (or curves of equal mean annual temperature)
both in a horizontal and* vertical direction, or on a uniform
plane, or in different superposed strata of air.

3. The distribution of the humidity of the atmosphere.
The quantitative relations of the humidity depend on the dif-
ferences in the solid and oceanic surfaces ; on the distance from
the equator and the level of the sea ; on the form in which the

la Composition Chimique des Vigitaux, p. 36, 42 ; Liebig, Org. Chemie,
s. 229-345; Boussingault, Econ. Rurale, t. i., p. 142-153.

* Bouvard, by the application of the formulaj, iu 1827, which Laplace
had deposited with the Board of Longitude shortly before his death,
found that the portion of the horary oscillations of the pressure of the
atmosphere, which depends on the attraction of the moon, can not raise
the mercury in the barometer at Paris more than the 0*018 of a milli-
meter, while eleven years' observations at the same place show the mean
barometric oscillation, from 9 A.M. to 3 P.M.. to be 0756 millim., and
from 3 P.M. to 9 P.M., 0-373 millim. See Mimoires de VAcnd. den
Science's, t. vii., 1827, p. 267.
Vol. I.— O

314 COSMOS.

aqueous vapor is precipitated, and on the connection existing
between these deposits and the changes of temperature, and
the direction and succession of winds.

4. Tlie electric condition of the atmosphere. The primary
cause of this condition, when the heavens are serene, is still
much contested. Under this head we must consider the re-
lation of ascending vapors to the electric charge and the form
of the clouds, according to the different periods of the day and
year ; the difference between the cold and warm zones of the
earth, or low and high lands ; the frequency or rarity of thun-
der storms, their periodicity and formation m summer and
winter ; the causal connection of electricity, with the infre-
quent occurrence of hail in the night, and with the phe-
nomena of water and sand spouts, so ably investigated by
Peltier.

The horary oscillations of the barometer, which in the trop-
ics present two maxima (viz., at 9 or 9i A.M., and lOi or
lOf P.M., and two minima, at 4 or ^ P.M., and 4 A.M.,
occurring, therefore, in almost the hottest and coldest hours),
have long been the object of my most careful diurnal and noc-
turnal observations.* Their regularity is so great, that, in
the daytime especially, the hour may be ascertained from the
height of the mercurial column without an error, on the av-
erage, of more than fifteen or seventeen minutes. In the tor-
rid zones of the New Continent, on the coasts as welli as at
elevations of nearly 13,000 feet above the level of the sea,
where the mean temperature falls to 44° -6, I have found the
regularity of the ebb and flow of the aerial ocean undisturbed
by storms, hurricanes, rain, and earthquakes. The amount
of the daily oscillations diminishes from 1'32 to 0'18 French
lines from the equator to 70° north latitude, where Bravais
made very accurate observations at Bosekop.f The supposi-
tion that, much nearer the pole, the height of the barometer
is really less at 10 A.M. than at 4 P.M., and, consequently,
that the maximum and minimum influences of these hours

* Observations faites pour conslater la MarcTie des Variations Horaires
du Barometre sous les Tropiques, in my Relation Historique du Voyage
aux Regions Equinoxiales, t. iii., p. 270-313.

t Bravais, in Kaemtz and Martins, MHiorologie, p. 263. At Halle
(51° 29' N. lat.), the oscillation still amounts to 0-28 lines. It would
seem that a great many observations w^ill be required in order to obtain
results that can be trusted in regard to the hours of the maximum and
minimum on mountains in the temperate zone. See the obser\'ation«
of horary variations, collected on the Faulhom in 1832, 1841, and 1842
(Martins, M^tiorologie, p. 254.)

ATMOSPHER.C PRESSURE. 315

are inverted, is not confirmed by Parry's observations at Port
Bowen (73° 14')-

The mean height of the barometer is somewhat less under
the equator and in the tropics, owing to the effect of the rising
current,* than in the temperate zones, and it appears to attain
its maximum in Western Europe between the parallels of 40°
and 45°. If with Kamtz we connect together by isobaromet-
ric lines those places which present the same mean difference
between the monthly extremes of the barometer, we shall have
curves whose geographical position and inflections yield im-
portant conclusions regarding the influence exercised by the
form of the land and the distribution of seas on the oscillations
of the atmosphere. Hindostan, with its high mountain chains
and triangular peninsulas, and the eastern coasts of the New
Continent, where the warm Gulf Stream turns to the east at
the Newfoundland Banks, exhibit greater isobarometric oscil-
lations than do the group of the Antilles and Western Europe.
The prevailing winds exercise a principal influence on the
diminutioi of the pressure of the atmosphere, and this, as we
have already mentioned, is accompanied, according to Daussy,
by an elevation of the mean level of the sea.t

As the most important fluctuations of the pressure of the
atmosphere, whether occurring with horary or annual regu-
larity, or accidentally, and then often attended by violence and
danger,^ are, like all the other phenomena of the weather,
mainly owing to the heating force of the sun's rays, it has
long been suggested (partly according to the idea of Lambert)
that the direction of the wind should be compared with the
height of the barometer, alternations of temperature, and the
increase and decrease of humidity. Tables of atmospheric
pressure during different winds, termed barometric windroses,
afford a deeper insight into the connection of meteorological
phenomena. § Dove has, with admirable sagacity, recognized,
in the " law of rotation" in both hemispheres, which he him-
self established, the cause of many important processes in the
aerial ocean. !l The difference of temperature between the

* Humboldt, Essai stir la Geographic des Plantes, 1807, p. 90; and
iu Rel. Hist., t. iii., p. 313 ; and on the diminution of atmospheric press-
ure in the tropical portions of the Atlantic, in Poggend., Annalen der
Physik, bd. xxxvii., s. 245-258, and s. 468-486.

t Daussy, in the Comptes Rendus, t. iii., p. 136.

X Dove, Ueber die Sturme, iu Poggend., An?ialen, bd. Hi., s. 1.

$ Leopold von Buch, BaromeLrische Windrose, iu Abhandl. der Akad.
der Wiss. zu Berlin aus den Jahren 1818-1819, s. 187.

II See Dove, Meteorologische Uniersuchungen, 1837, s. '^'^-313; and

316 COSMOS.

equatorial and polar regions engenders two opposite currents
in the upper strata ot the atmosphere and on the Earth's sur«
face. Owing to the difierence between the rotatory velocity
at the poles and at the equator, the polar current is deflected
eastward, and the equatorial current westward. The great
phenomena of atmospheric pressure, the warming and cooling
of the strata of air, the aqueous deposits, and even, as Dove
has correctly represented, the formation and appearance of
clouds, alike depend on the opposition of these two currents,
on the place where the upper one descends, and on the dis-
placement of the one by the other. Thus the figures of the
clouds, which form an animated part of the charms of a land-
scape, announce the processes at work in the upper regions of
the atmosphere, and, when the air is calm, the clouds will
often present, on a bright summer sky, the " projected image"
of the radiating soil below.

Where this influence of radiation is modified by the relative
position of large continental and oceanic surfaces, as between
the eastern shore of Africa and the western part of the Indian
peninsula, its effects are manifested in the Indian monsoons,
which change with the periodic variations in the sun's decli-
nation,* and which were known to the Greek navigators un-
der the name of Hippalos. In the knowledge of the mon-
soons, which undoubtedly dates back thousands of years among
the inhabitants of Hindostan and China, of the eastern parts
■)f the Arabian Gulf and of the western shores of the Malayan

lie excellent observations of Kamtz on the descent of the west wind
of the upper current in high latitudes, and the general phenomena of
the direction of the wind, in his Vorlesungen uber Meterologie, 1840, s.
58-66, 196-200, 327-336, 353-364; and in Schumacher's Ja^riwc^ /Sr
1838, s. 291-302. A very satisfactory and vivid representation of me-
teorological phenomena is given by Dove, in his small work entitled
Wittertmgsverkdltnisse von Berlin, 1842. On the knowledge of the
earlier navigators of the rotation of the wind, see Churruca, Viage ai
Magellanes, 1793, p. 15 ; and on a remarkable expression of Columbus,
which his son Don Fernando Colon has presented to us in his Vida del
Almirante, cap. 55, see Humboldt, Examen Critique de VHist. de G€-
ographie, t. iv., p. 253.

* Monsun (Malayan musim, the hippalos of the Greeks) is derived
from the Arabic word mausim, a set time or season of the year, the time
of the assemblage of pilgrims at Mecca. The word has been applied
to the seasons at which certain winds prevail, which are, besides, named
from places lying in the direction from whence they come ; thus, for
instance, there is the mausim of Aden, of Guzerat, Malabar, &c. (Las-
een, Indische Alterthumshunde, bd. i., 1843, s. 211). On the contrasts
between the solid or fluid substrata of the atmosphere, see Dove, in Der
AbhaJtdl. der Akad. der Wiss. zu Berlin aus dem Jahr 1842, s. 239

CLIMATOLOGY. 317

Sea, and in the still more ancient and more general acc^^uaint-
ance with land and sea winds, lies concealed, as it were, the
germ of that meteorological science which is now making such
rapid progress. The long chain o£ 9nagnetic stations extend-
ing from Moscow to Pekin, across the whole of Northern Asia,
will prove of immense importance in determining the law of
the winds, since these stations have also for their object the
investigation of general meteorological relations. The com-
parison of observations made at places lying so many hundred
miles apart, will decide, for instance, whether the same east
wind blows from the elevated desert of Gobi to the interior of
Kussia, or whether the direction of the aerial current first be-
gan in the middle of the series of the stations, by the descent
of the air from the higher regions. By means of such observ-
ations, we may learn, in the strictest sense, whence the wind
Cometh. If we only take the results on which we may de-
pend from those places in which the observations on the direc-
tion of the winds have been continued more than twenty years,
we shall find (from the most recent and careful calculations
of Wilhelra Mahlmann) that in the middle latitudes of the
temperate zone, in both continents, the prevailing aerial cur-
rent has a west-southwest direction.

Our insight into the distribution of heat in the atmosphere
has been rendered more clear since the attempt has been made
to connect together by lines those places where the mean an-
nual summer and winter temperatures have been ascertained
by correct observations. The system oi isothermal, isotheral.,
and isodmnenal lines, which I first brought into use in 1817,
may, perhaps, if it be gradually perfected by the united efibrts
of investigators, serve as one of the main foundations of com-
parative climatology. Terrestrial magnetism did not acquire
a right to be regarded as a science until partial results were
graphically connected in a system of lines of equal declina-
tio7i, equal i)iclination, and equal intensity.

The term climate, taken in its most general sense, indicates
all the changes in the atmosphere which sensibly affect our
organs, as temperature, humidity, variations in the baromet-
rical pressure, the calm state of the air or the action of oppo
site winds, the amount of electric tension, the purity of the
atmosphere or its admixture with more or less noxious gase-
ous exhalations, and, finally, the degree of ordinary transpar-
ency and clearness of the sky, which is not only important
with respect to the increased radiation from the Earth, the
organic development of plants, and the rif '.ning of fruits, but

318 COSMOS.

Also with reference to its influence on the feelings and mental
condition of men.

If the surface of the Earth consisted of one and the same
homogeneous fluid mass, or of strata of rock having the same
color, density, smoothness, and power of absorbing heat from
the solar rays, and of radiating il; in a similar manner through
the atmosphere, the isothermal, isotheral, and isochimenal
lines would all be parallel to the equator. In this hypothet-
ical condition of the Earth's surface, the power of absorbing
and emitting light and heat would every where be the same
undsft: the same latitudes. The mathematical consideration
of climate, which does not exclude the supposition of the ex-
istence of currents of heat in the interior, or in the external
crust of the earth, nor of the propagation of heat by atmos-
pheric currents, proceeds from this mean, and, as it were,
primitive condition. Whatever alters the capacity for ab-
sorption and' radiation, at places lying under the same parallel
of latitude, gives rise to inflections in the isothermal lines.
The nature of these inflections, the angles at which the iso-
thermal, isotheral, or isochimenal lines intersect the parallels
of latitude, their convexity or concavity with respect to the
pole of the same hemisphere, are dependent on causes which
more or less modify the temperature under different degrees
of longitude.

The progress of Climatology has been remarkably favored
by the extension of European civilization to two opposite
coasts, by its transmission from our western shores to a conti-
nent which is bounded on the east by the Atlantic Ocean.
When, after the ephemeral colonization from Iceland and
Greenland, the British laid the foundation of the first perma-
nent settlements on the shores of the United States of Amer-
ica, the emigrants (whose numbers were rapidly increased in
consequence either of rehgious persecution, fanaticism, or love
of freedom, and who soon spread over the vast extent of ter-
ritory lying between the Carolinas, Virginia, and the St. Law-
rence) were astonished to find themselves exposed to an intens-
ity of winter cold far exceeding that which prevailed in Ita-
ly, France, and Scotland, situated in corresponding parallels
of latitude. But, however much a consideration of these cH-
matic relations may have awakened attention, it was not at-
tended by any practical results until it could be based on the
numerical data of mean annual temi:)erature. If, between
58*^ and 30"^ north latitude, we compare Nain, on the coast
of Labrador, with Gottenburg ; Halifax with Bordeaux ; INew

CLIMATOLOGY. 3 IP

York with Naples ; St. Augustine, in Florida, with Cairo, we
find that, under the same degrees ^f latitude, the differences
of the mean annual temperature between Eastern America
and Western Europe, proceeding from north to south, are suc-
cessively 20O-7, 1309, 60-8, and almost QO. The gradual
decrease of the differences in this series extending over 28^
of latitude is very striking. Further to the south, under the
tropics, the isothermal lines are every where parallel to the
equator in both hemispheres. We see, from the above exam-
ples, that the questions often asked in society, how many de-
grees America (without distinguishing between the eastern
and western shores) is colder than Europe ? and how much
the mean annual temperature of Canada and the United
States is lower than that of corresponding latitudes in Eu-
rope ? are, when thus generally expressed, devoid of meaning.
There is a separate difference for each parallel of latitude, and
without a special comparison of the winter and summer tem-
peratures of the opposite coasts, it will be impossible to arrive
at a correct idea of climatic relations, in their influence on
agriculture and other industrial pursuits, or on the individual
comfort or discomfort of mankind in general.

In enumerating the causes which produce disturbances in
the form of the isothermal lines, I would distinguish between
those which raise and those which lower the temperature.
To the first class belong the proximity of a western coast in
the temperate zone ; the divided configuration of a continent
into peninsulas, with deeply-indented bays and inland seas ,
the aspect or the position of a portion of the land with refer-
ence either to a sea of ice spreading far into the polar circle,
or to a mass of continental land of considerable extent, lying
in the same meridian, either under the equator, or, at least,
within a portion of the tropical zone ; the prevalence of south-
erly or westerly winds on the western shore of a continent in
the temperate northern zone ; chains of mountains acting as
protecting walls against winds coming from colder regions ;
the infrequency of swamps, which, in the spring and begin-
ning of summer, long remain covered with ice, and the ab-
sence of woods in a dry, sandy soil ; finally, the constant se-
renity of the sky in the summer months, and the vicinity of
an oceanic current, bringing water which is of a higher tem-
perature than that of the surrounding sea.

Among the causes which tend to lower the mean annual
temperature I include the following : elevation above the level
of the sea, when not forming part of an extended plain ; the

520 COSMOS.

vicinity of an eastern coast in high and middle latitudes ; the
compact configuration of jl continent having no littoral curv-
atures or bays ; the extension of land toward the poles into
the region of perpetual ice, without the intervention of a sea
remaining open in the winter ; a geographical position, in
which the equatorial and tropical regions are occupied by the
sea, and, consequently, the absence, under the same meridian,
of a continental tropical land having a strong capacity for the
absorption and radiation of heat ; mountain chains, whose
mural form and direction impede the access of warm winds ,
the vicinity of isolated peaks, occasioning the descent of cold
currents of air down their declivities ; extensive woods, which
hinder the insolation of the soil by the vital activity of theii
foliage, which produces great evaporation, owing to the ex-
tension of these organs, and increases the surface that is cool-
ed by radiation, acting consequently in a three-fold manner,
by shade, evaporation, and radiation ; the frequency of swamps
or marshes, which in the north form a kind of subterranean
glacier in the plains, lasting till the middle of the summer ; a
cloudy summer sky, which weakens the action of the solar
rays ; and, finally, a very clear winter sky, favoring the radi-
ation of heat.*

The simultaneous action of these disturbing causes, wheth-
er productive of an increase or decrease of heat, determines,
as the total effect, the infl.ection of the isothermal lines, espe-
cially with relation to the expansion and configuration of solid
continental masses, as compared with the liquid oceanic.
These perturbations give rise to convex and concave summits
of the isothermal curves. There are, however, different or-
ders of disturbing causes, and each one must, therefore, be
considered separately, in order that their total effect may aft-
erward be investigated with reference to the motion (direc-
tion, local curvature) of the isothermal lines, and the actions
by which they are connected together, modified, destroyed, or
increased in intensity, as manifested in the contact and inter-
section of small oscillatory movements. Such is the method
by which, I hope, it may some day be possible to connect to-
gether, by empirical and numerically expressed laws, vast se-
ries of apparently isolated facts, and to exhibit the mutual de-
pendence which must necessarily exist among them.

The trade winds — easterly winds blowing within the trop-
ics— give rise, in both temperate zones, to the west, or west-

* Humboldt, Recherches sur les Causes des Inflexions des Li^nes Iso-
thermes, in Asie Centr., t. iii., p. 103-114, 118, 122, 188.

CLIMATOLOGY. 321

southwest winds which prevail in those regions, and which
are land winds to eastern coasts, and sea winds to western
coasts, extending over a space which, from the great mass
and the sinking of its cooled particles, is not capable of any
considerable degree of cooling, and hence it follows that the
east winds of the Continent must be cooler than the west
winds, where their temperature is not affected by the occur-
rence of oceanic currents near the shore. Cook's young com-
panion on his second voyage of circumnavigation, the intelli-
gent George Forster, to whom I am indebted for the lively
interest which prompted me to undertake distant travels, was
the first who drew attention, in a definite manner, to the cli-
matic differences of temperature existing in the eastern and
western coasts of both continents, and to the similarity of
temperature of the western coast of North America in the
middle latitudes, with that of Western Europe.* Even in
northern latitudes exact observations show a striking differ-
ence between the mean annual temperature of the east and
west coasts of America. The mean annual temperature of
Nain, in Labrador (lat. 57° 10'), is fully 60-8 below the freez-
ing point, while on the northwest coast, at New Archangel,
in Russian America (lat. 57° 3'), it is 12Q-4 above this point.
At the first-named place, the mean summer temperature
hardly amounts to 43°, while at the latter place it is 57*^.
Pekin (39° 54'), on the eastern coast of Asia, has a mean an-
nual temperature of 52°-3, which is 9° below that of Naples,
situated somewhat further to the north. The mean winter
temperature of Pekin is at least 5°"4 below the freezing point,
while in Western Europe, even at Paris (48° 50'), it is near-
ly -6° above the freezing point. Pekin has also a mean win-
ter cold which is 4° 5 lower than that of Copenhagen, lying
17° further to the north.

We have already seen the slowness with which the great
mass of the ocean follows the variations of temperature in the
atmosphere, and how the sea acts in equalizing temperatures,
moderating simultaneously the severity of winter and the heat
of summer. Hence arises a second more important contrast
— that, namely, between insular and littoral climates enjoyed
by all articulated continents having deeply-indented bays and
peninsulas, and between the climate of the interior of great
masses of solid land. This remarkable contrast has been fully

* George Forster, Kleine Schriften, th. iii., 1794, s. 87 ; Dove, iu
Schumacher's Jahrbuch fur 1841, s. 289; Kamtz, MeteoroJogie, bd. i:,,
8. 41. 43, 67, and 96 ; Arago, in the Comptes Rendtcs, t. i., p. 268.

02

3218 COSMOS.

i^eveloped by Leopold von Buch in all its various phenomena,
both with respect to its influence on vegetation and agricul-
ture, on the transparency of the atmosphere, the radiation of
the soil, and the elevation of the line of perpetual snow. In
the interior of the Asiatic Continent, Tobolsk, Barnaul on the
Oby, and Irkutsk, have the same mean summer heat as Ber-
lin, Munster, and Cherbourg in Normandy, the thermometer
sometimes remaining for weeks together at 86° or 88°, while
the mean winter temperature is, during the coldest month, as
low as — 0°-4 to — 4°. These continental climates have
therefore justly been termed excessive by the great mathema-
tician and physicist BufTon ; and the inhabitants who live in
countries having such excessive climates seem almost con-
demned, as Dante expresses himself,

" A sofferir tormenti caldi e geli."*

In no portion of the earth, neither in the Canary Islands,
in Spain, nor in the south of France, have I ever seen more
luxuriant fruit, especially grapes, than in Astrachan, near the
shores of the Caspian Sea (46° 21'). Although the mean
annual temperature is about 48°, the mean summer heat
rises to 70°, as at Bordeaux, while not only there, but also
further to the south, as at Kislar on the mouth of the Terek
(in the latitude of Avignon and Rimini), the thermometer
Binks in the winter to — 13° or — 22°.

Ireland, Guernsey, and Jersey, the peninsula of Brittany,
the coasts of Normandy, and of the south of England, present,
by the mildness of their winters, and by the low temperature
and clouded sky of their summers, the most striking contrast
to the continental climate of the interior of Eastern Europe.
In the northeast of Ireland (54° 56'), lying under the same par-
allel of latitude as Konigsberg in Prussia, the myrtle blooms
as luxuriantly as in Portugal. The mean temperature of the
month of August, which in Hungary rises to 70°, scarcely
reaches 61° at Dublin, which is situated on the same isother-
mal line of 49° ; the mean winter temperature, which falls to
about 28° at Pesth, is 40° at Dublin (whose mean annual
temperature is not more than 49°) ; 3°-6 higher than that of
Milan, Pavia, Padua, and the whole of Lombardy, where the
mean annual temperature is upward of 65'\ At Stromness,
in the Orkneys, scarcely half a degree further south than Stock-
holm, the winter temperature is 39°, and consequently highei
than that of Paris, and nearly as high as that of London.
* Dante, Divina Commedia, Purgatoi-io, canto iii.

CLIMATOLOGY. 323

Even in the Faroe Islands, at 62° latitude, the inland waters
never freeze, owing to the favoring influence of the west winds
and of the sea. On the charming coasts of Devonshire, near
Salcomhe Bay, which has been termed, on account of the
mildness of its climate, the Mont-pellier of the Nwth, the
Agave Mexicana has been seen to blossom in the open air,
while orange-trees trained against espaliers, and only slightly
protected by matting, are found to bear fruit. There, as well
as at Penzance and Gosport, and at Cherbourg on the coast
of Normandy, the mean winter temperature exceeds 42°, fall-
ing short by only 2^*4 of the mean winter temperature of
Montpellier and Florence.* These observations will suffice
to show the important influence exercised on vegetation and
agriculture, on the cultivation of fruit, and on the comfort of
mankind, by differences in the distribution of the same mean
annual temperature, through the different seasons of the year.
The lines which I have termed isochimenal and isotheral
(lines of equal winter and equal summer temperature) are by
no means parallel with the isothermal lines (lines of equal
annual temperature). If, for instance, in countries where
myrtles grow wild, and the earth does not remain covered
with snow in the winter, the temperature of the summer and
autumn is barely sufficient to bring apples to perfect ripeness,
and if, again, we observe that the grape rarely attains the
ripeness necessary to convert it into wine, either in islands or
in the vicinity of the sea, even when cultivated on a western
coast, the reason must not be sought only in the low degree
of summer heat, indicated, in littoral situations, by the ther-
mometer when suspended in the shade, but likewise in another
cause that has not hitherto been sufficiently considered, al-
though it exercises an active influence on many other phe-
nomena (as, for instance, in the inflammation of a mixture of
chlorine and hydrogen), namely, the difference between direct
and diffused light, or that which prevails when the sky is clear
and when it is overcast by mist. I long since endeavored to
attract the attention of physicists and physiologistsf to this

* Humboldt, Sur lea Lignes Isothermes, in the Mimoires de Physique
n de Chimie de la SocUti d^Arcueil, t. iii., Paris, 1817, p. 143-165 ;
Knight, in the Transactions of the Horticultural Society of London, vol.
, p. 32 ; Watson, Remarks on the Geographical Distribution of British
Plants, 183.5, p. 60 ; Trevelyan, in Jamieson's Edinburgh New Phil.
Journal, No. 18, p. 154; Mahlraann, in his admirable German transla
lion of my Asie Centrals, th. ii., s. 60.

t " Hicc de tem[)etie aeris, qui terram late circumfundit, ac in quo,
loiige a solo, instminenta nostra raeleorologica suspensa habemus. Sed

324 OiSMOs.

difference, and to the unmeasured heat which is locally devel-
oped in the living vegetable cell by the action of direct light.
If, in forming a thermic scale of different kinds of cultiva-
tion,* we begin with those plants which require the hottest
climate, as the vanilla, the cacao, banana, and cocoa-nut, and
proceed to pine-apples, the sugar-cane, coffee, fruit-bearing
date-trees, the cotton-tree, citrons, olives, edible chestnuts, and
vines producing potable wine, an exact geographical consider-
ation of the limits of cultivation, both on plains and on the
declivities of mountains, will teach us that other climatic re-
lations besides those of mean annual temperature are involved
in these phenomena. Taking an example, for instance, from
the cultivation of the vine, we find that, in order to procure
potable wine,t it is requisite that the mean annual heat should
exceed 49^, that the winter temperature should be upward of
33^, and the mean summer temperature upward of 64^. At
Bordeaux, in the valley of the Garonne {4.\P 50' lat.), the
mean annual, winter, summer, and autumn temperatures are
respectively 57*^, 43^^, 71°, and 58^. In the plains near the

alia est caloi'is vis, quern radii solis nuUis nubibus velati, in foliis ipsis
et fructibus maturescentibus, magis minusve coloratis, gignunt, quem-
que, ut egregia demonstrant experimenta amicissimorum Gay-Lussacii
et Thenardi de combustione chlori et hydrogenis, ope thermometri me-
tiri nequis, Etenim locis planis et montanis, vento libe spirante, cir-
cumfusi aeris temperies eadem esse potest coelo sudo vel nebuloso ; ide-
oque ex observationibus solis thermometricis, nullo adhibito Photome-
tro, baud cognosces, quam ob causam Galliae septentrionalis tractus
Armoricanus et Nervicus, versus littora, coelo temperato sed sole raro
utentia, Vitem fere non tolerant. Egent enim stirpes non solum caloris
stimulo, sed et lucis, quae magis intensa locis excelsis quam planis, du-
plici modo plantas movet, vi sua turn propria, tum calorem in superficie
earum excitante." — Humboldt, De Distributione GeograpMca Planta-
rum, 1817, p. 163-164.

* Humboldt, op. cit., p. 156-161; Meyen, in his Grundriss der
Pjlanzengeographie, 1836, s. 379-467 ; Boussingault, Economie Rurale,
t. ii., p. 675.

t The following table illustrates the cultivation of the vine in Europe,
and also the depreciation of its produce according to climatic relations.
See my Asie Centrale, t. iii., p. 159. The examples quoted in the text
for Bordeaux and Potsdam are, in respect of numerical relation, alike
applicable to the countries of the Rhine and Maine (48'^ 35' to 50*^ 7'
N. lat.). Cherbourg in Normandy, and Ireland, show in the most re-
markable manner how, with thermal relations very nearly similar to
those prevailing in the interior of the Continent (as estimated by the
thermometer in the shade), the results are nevertheless extremely dif«
ferent as regards the ripeness or the unripeness of the fruit of the vine,
this difference undoubtedly depending on the circumstance whether
the vegetation of the plant proceeds under a bright sunny sky, c un
der a sky that is habitually obscured by clouds:

CLIMATOLOGY.

a25

Baltic (52^ 30' lat.), w^here a wine is produced that can
scarcely be considered potable, these numbers are as follows :
4.7'^- 5, 31°, 63'' -7, and 47^'5. If it should appear strange
that the great differences indicated by the influence of climate
on the production of wine should not be more clearly manifest-
ed by our thermometers, the circumstance will appear less
singular when we remember that a thermometer standing in
the shade, and protected from the effect of direct insolation
and nocturnal radiation can not, at all seasons of the year, and
during all periodic changes of heat, indicate the true superficial
temperature of the ground exposed to the whole effect of the
sun's rays.

The same relations which exist between the equable littoral
climate of the peninsula of Brittany, and the lower winter and

Places.

Latitude.

Elevation.

Mean
of the
Year.

Winter.

Spring.

S'jmraer.

Autumn.

III

S5><0

Bordeaux . . .

44 50

EnR.ft.

25-6

Fahr.

57-0

43-0

56-0

71-0

580

10

Strasbourg. . .

48 35

479-0

49-6

34-5

50-0

64-6

50-0

35

Heidelberg. .

49 24

333-5

49-5

34-0

50-0

64-3

49-7

20

Manheira . . .

49 29

300-5

50-6

34-6

50-8

67-1

49-5

12

WOrzburg. . .

49 48

562-5

50-2

35-5

50-5

65-7

49-4

27

Frankfort on

Maine ....

50 7

388-5

49-5

33-3

50-0

64-4

49-4

19

Berlin

52 31

102-3

47-5

31-0

46-6

63-6

47-5

23

Cherbourg (no

49 39

....

52-1

41-5

50-8

61-7

54-3

3

wine)

Dublin (ditto)

53 23

....

49-1

40-2

47-1

59-6

49-7

13

The great accordance in the distribution of the annual temperatm-e
through the different seasons, as presented by the results obtained for
the valleys of the Rhine and Maine, tends to confirm the accuracy of
these meteorological observations. The months of December, January,
and February are reckoned as winter months. When the different
qualities of the wines produced in Franconia, and in the countriea
around the Baltic, are compared with the mean summer and autumn
temperature of WUrzburg and Berlin, we are almost surprised to find
a difference of only about two degrees. The difference in the spring
is about four degrees. The influence of late May frosts on the flower-
ing season, and after a correspondingly cold winter, is almost as im
portant an element as the time of the subsequent ripening of the grape,
and the influence of direct, not diffused,, light of the unclouded sun
The difference alluded to in the text between the true temperature oi
the surface of the ground and the indications of a thermometer sus
pended in the shade and protected from extraneous influences, is in ■
ferred by Dove from a consideration of the results of fifteen years' ob
servations made at the Chiswick Gardens. See Dove, in Bericht ube»
die Verhandl. der Berl. Akad. der Wiss., August, 1844, s. 285.

S26 COSMOS.

higher summir temperature of the remainder of the continent
of France, are likewise manifested, in some degree, between
Europe and the great continent of Asia, of which the former
may be considered to constitute the western peninsula. Eu-
rope owes its milder climate, in the first place, to its position
with respect to Africa, whose wide extent of tropical land is
favorable to the ascending current, while the equatorial region
to the south of Asia is almost wholly oceanic ; and next to its
deeply-articulated configuration, to the vicinity of the ocean
on its western shores ; and, lastly, to the existence of an open
sea, which bounds its northern confines. Europe would there-
fore become colder* if Africa were to be overflowed by the
ocean ; or if the mythical Atlantis were to arise and connect
Europe with North America ; or if the Gulf Stream were no
longer to difTuse the warming influence of its waters into tht»
North Sea ; or if, finally, another mass of solid land should be
upheaved by volcanic action, and interposed between the
Scandinavian peninsula and Spitzbergen. If we observe that
in Europe the mean annual temperature falls as we proceed,
from Avest to east, under the same parallel of latitude, from
the Atlantic shores of France through Germany, Poland, and
Russia, toward the Uralian Mountains, the main cause of this
phenomenon of increasing cold must be sought in the form of
the continent (which becomes less indented, and wider, and
more compact as we advance), in the increasing distance from
seas, and in the diminished influence of westerly winds. Be-
yond the Uralian Mountains these winds are converted into
cool land-winds, blowing over extended tracts covered with
ice and snow. The cold of western Siberia is to be ascribed
to these relations of configuration and atmospheric currents,
and not — as Hippocrates and Trogus Pompeius, and even cele-
brated travelers of the eighteenth century conjectured — to the
great elevation of the soil above the level of the sea.t

If we pass from the differences of temperature manifested in
the plains to the inequalities of the polyhedric form of the sur-
face of our planet, we shall have to consider mountains either
in relation to their influence on the climate of neighboring

* See my memoir, Ueber die Havpt-Ursachen der Temperaturver-
schiedenheit aiif der Erdoberjldche, in the Abhandl. der Akad. der WiS'
sensch. zu Berlin von dem Jahr 1827, s. 311.

+ The general level of Siberia, from Tobolsk, Tomsk, and Barnaul,
from the Altai Mountains to the Polar Sea, is not so high as that of
Mauheim and Dresden ; indeed, Irkutsk, far to the east of the Jenisei.
is only 1330 feet above the level of the sea, or about one third lowe/
than Munich.

CLIMATOLOGY. 327

valleys, or according to the effects of the hypsometrical rela-
tions on their own summits, which often spread into elevated
plateaux. The division of mountains into chains separates
the earth's surface into different basins, which are often nar
row and walled in, forming caldron-like valleys, and (as in
Greece and in part of Asia Minor) constitute an individual
local climate with respect to heat, moisture, transparency of
atmosphere, and frequency of winds and storms. These cir-
cumstances have at all times exercised a powerful influence
on the character and cultivation of natural products, and on
the manners and institutions of neighboring nations, and even
on the feelings with which they regard one another. This
character of geographical individuality attains its maximum,
if we may be allowed so to speak, in countries where the dif
ferences in the configuration of the soil are the greatest possi-
ble, either in a vertical or horizontal direction, both in relief
* and in the articulation of the continent. The greatest con-
trast to these varieties in the relations of the surface of the
earth are manifested in the Steppes of Northern Asia, the
grassy plains (savannahs, llanos, and pampas) of the New
Continent, the heaths (Ericeta) of Europe, and the sandy and
Btony deserts of Africa.

The law of the decrease of heat with the increase of eleva-
tion at different latitudes is one of the most important subjects
involved in the study of meteorological processes, of the geog-
raphy of plants, of the theory of terrestrial refraction, and of
the various hypotheses that relate to the determination of the
height of the atmosphere. In the many mountain journeys
which I have undertaken, both within and without the trop-
ics, the investigation of this law has always formed a special
object of ray researches.*

Since we have acquired a more accurate knowledge of the
true relations of the distribution of heat on the surface of the
earth, that is to say, of the inflections of isothermal and isoth-
eral lines, and their unequal distance apart in the different
eastern and western systems of temperature in Asia, Central
Europe, and North America, we can no longer ask the gen-
eral question, what fraction of the mean annual or summer
temperature corresponds to the difference of one degree of
geographical latitude, taken in the same meridian ? In each
system of isothermal lines of equal curvature there reigns a

* Humboldt, Recueil d'' Observations Astronomiqnes, t. i., p. 126-140;
Relation Hislorique, t. i., p. 119, 141 227; Biot, in Connaissance de»
Temps pour Van 1841, p. 90-109.

328 COSMOS.

close and necessary connection between three elements, name-
iy, the decrease of heat in a vertical direction from below up
^ard, ti.e difference of temperature for every one degree of
geof^raphical latitude, and the uniformity in the mean tem-
perature of a mountain station, and the latitude of a point
situated at the level of the sea.

In the system of Eastern America, the mean annual temper-
ature from the coast of Labrador to Boston changes 1°'6 foi
every degree of latitude ; from Boston to Charleston about
1°"7 ; from Charleston to the tropic of Cancer, in Cuba, the
variation is less rapid, being only 1°'2. In the tropics this
diminution is so much greater, that from the Havana to
Cumana the variation is less than 0°-4 for every degree of
latitude.

The case is quite different in the isothermal system of Cen-
tral Europe. Between the parallels of 38° and 71° I found
that the decrease of temperature was very regularly 0°'9 foi
every degree of latitude. But as, on the other hand, in Cen-
tral Europe the decrease of heat is l°-8 for about every 534
feet of vertical elevation, it follows that a difference of eleva-
tion of about 267 feet corresponds to the difference of one de-
gree of latitude. The same mean annual temperature as that
occurring at the Convent of St. Bernard, at an elevation of
8173 feet, in lat. 45° 50', should therefore be met with at the
level of the sea in lat. 75° 50'.

In that part of the Cordilleras which falls within the tropics,
the observations I made at various heights, at an elevation of
upward of 19,000 feet, gave a decrease of 1° for every 341
feet ; and my friend Boussingault found, thirty years after-
ward, as a mean result, 319 feet. By a comparison of places
in the Cordilleras, lying at an equal elevation above the level
of the sea, either on the declivities of the mountains or even
on extensive elevated plateaux, I observed that in the latter
there was an increase in the annual temperature varying from
2°-7 to 4°-l. This difference would be still greater if it were
iiot for the cooling effect of nocturnal radiation. As the dif-
ferent climates are arranged in successive strata, the one above
the other, from the cacao woods of the valleys to the region
of perpetual snow, and as the temperature in the tropics va-
ries but. little throughout the year, we may form to ourselves
a tolerably correct representation of the climatic relations to
which the inhabitants of the large cities in the Andes are sub-
jected, by comparing these climates with the temperatures of
particular months in the plains of France and Italy. Whila

THE SNOW-LINE.

the heat which prevails daily on the woody shores of the
Orinoco exceeds by 7° "2 that of the month of August at Pa-
lermo, we find, on ascending the chain of the Andes, at Po-
payan, at an elevation of 5826 feet, the temperature of the
three summer months of Marseilles ; at Quito, at an eleva-
tion of 9541 feet, that of the close of May at Paris ; and on
the Paramos, at a height of 11,510 feet, where only stunted
Alpine shrubs grow, though flowers still bloom in abund-
ance, that of the beginning of April at Paris. The intelligent
observer, Peter Martyr- de Anghiera, one of the friends of
Christopher Columbus, seems to have been the first who rec-
ognized (in the expedition undertaken by Rodrigo Enrique
Colmenares, in October, 1510) that the limit of perpetual
snow continues to ascend as we approach the equator. We
read, in the fine work De Rebus Oceanicis* " the River Gaira
comes from a mountain in the Sierra Nevada de Santa Marta,
which, according to the testimony of the companions of Col-
menares, is higher than any other mountain hitherto discov-
ered. It must undoubtedly be so if it retain snoio perpet-
ually in a zone which is not more than 10° from the equi-
noctial line." The lower limit of perpetual snow, in a given
latitude, is the lowest line at which snow continues during
summer, or, in other words, it is the maximum of height to
which the snow-line recedes in the course of the year. But
this elevation must be distinguished from three other phe-
nomena, namely, the annual fluctuation of the snow-line, the
occurrence of sporadic falls of snow, and the existence of gla-
ciers, which appear to be peculiar to the temperate and cold
zones. This last phenomenon, since Saussure's immortal
work on the Alps, has received much light, in recent times,
from the labors of Venetz, Charpentier, and the intrepid and
persevering observer Agassiz.

We know only the lower, and not the upper limit of per-
petual snow ; for the mountains of the earth do not attain to
those ethereal regions of the rarefied and dry strata of air, in
which we may suppose, with Bouguer, that the vesicles of
aqueous vapor are converted into crystals of ice, and thus ren-
dered perceptible to our organs of sight. The lower limit of
snow is not, however, a mere function of geographical latitude
cr of mean annual temperature ; nor is it at the equator, or

* Anglerius, De Rebus Oceanicis, Dec. xi., lib. ii , p. 140 (ed. Col.,
1574). In the Sierra de Santa Marta, the highest point of which ap-
pears to exceed 19,000 feet (see my Rilat. Hist., t. ii., p. 214), there is
B peak that is still called Fico de Gaira.

330 COSMOS.

even in the region of the tropics, that this limit attains its
greatest elevation above the level of the sea. The phenome-
non of which we are treating is extremely complicated, de-
pending on tht general relations of temperature and humidity,
and on the form of mountains. On submitting these relations
to the test of special analysis, as we may be permitted to do
from the number of determinations that have recently been
made,* we shall find that the controlling causes are the dif-
ferences in the temperature of different seasons of the year ;
the direction of the prevailing winds and their relations to the
land and sea ; the degree of dryness or humidity in the upper
strata of the air ; the absolute thickness of the accumulated
masses of fallen snow ; the relation of the snow-line to the to-
tal height of the mountain ; the relative position of the latter
in the chain to which it belongs, and the steepness of its de-
clivity ; the vicinity of other summits likewise perpetually
covered with snow ; the £xpansion, position, and elevation of
the plains from which the snow-mountain rises as an isolated
peak or as a portion of a chain ; whether this plain be j^art
of the sea-coast or of the interior of a continent ; whether it
be covered with wood or waving grass ; and whether, finally, it
consist of a dry and rocky soil, or of a wet and marshy bottom.
The snow-line which, under the equator in South Ameri-
ca, attains an elevation equal to that of the summit of Mont
Blanc in the Alps, and descends, according to recent measure-
ments, about 1023 feet lower toward the northern tropic in
the elevated plateaux of Mexico (in 19^ north latitude), rises,
according to Pentland, in the southern tropical zone (14"^ 30'
to 18^ south latitude), being more than 2665 feet higher in
the maritime and western branch of the Cordilleras of Chili
than under the equator near Quito on Chimborazo, Cotopaxi,
and Antisana. Dr. Gillies even asserts that much further to
the south, on the declivity of the volcano of Peuquenes (lati-
tude 33°), he found the snow-line at an elevation of between
14,520 and 15,030 feet. The evaporation of the snow in the
extremely dry air of the summer, and under a cloudless sky,
is so powerful, that the volcano of Aconcagua, northeast of
Valparaiso (latitude 32° 30'), which was found in the expe-
dition of the Beagle to be more than 1400 feet higher than
Chimborazo, was on one occasion seen free from snow.t In

* See my table of the height of the line of perpetual snow, in both
bemispheres, from 71° 15' north lat. to 53° 54' south lat., in my Asi4
Centrale, t. iii., p. 360.

t Parwin, Journal of the Voyages of the Adventure and Beagle, p. '297

THE SNOW-LINE. 331

an almost equal northern latitude (from 30^ 45' to 31°), the
enow-line on the southern declivity of the Himalaya lies at an
elevation of 12,982 feet, which is about the same as the height
which" we might have assigned to it from a comparison v/hh
other mountain chaini ; on the nortliern declivity, however,
under the influence of the high lands of Thibet (whose mean
elevation appears to be about 11,510 feet), the snow-line is
situated at a height of 16,630 feet. This phenomenon, which
has long been contested both in Europe and in India, and
whose causes I have attempted to develop in various works,
published since 1820,* possesses other grounds of interest than

As the volcano of Aconcagua was not at that time in a state of eruption,
we must not ascribe the remarkable phenomenon of the absence of
snow to the internal heat of the mountain (to the escape of heated air
through fissures), as is sometimes the case with Cotopaxi. Gillies, in
the Jotirnal of Natural Science, 1830, p. 316.

* See my Second M6inoire sur les Montagues de VInde, in the Annates
de Chimie et de Physique, t. xiv., p. 5-55; and Asie Centrale, t. iii., p.
281-327. While the most learned and experienced travelers in India,
Colebrooke, Webb, and Hodgson, Victor Jacquemont, Forbes Royle,
Carl von Hiigel, and Vigne, who have all personally examined the
Jttimulaya range, are agreed regarding the greater elevation of the
snow-line on the Thibetian side, the accuracy of this statement is called
in question by John Gerard, by the geognosist MacClelland, the editor
of the Calcutta Journal, and by Captain Thomas Hutton, assistant sur-
veyor of the Agra Division. The appearance of my work on Central
Asia gave rise to a rediscussion of this question. A recent number (vol.
iv., January, 1844) of MacClelland and Griffith's Calcutta Journal of
Natural History contains, however, a very remarkable and decisive no-
tice of the determination of the snow-line in the Himalayas. Mr. Bat-
ten, of the Bengal service, writes as follows from Camp Semulka, on the
Cosillah River, Kumaon : "In the July, 1843, No. 14 of your valuable
Journal of Natural History, which I have only lately had the opportuni-
ty of seeing, I read Captain Hutton's paper on the snow of the Hima-
layas, and as I differed almost entirely from the conclusions so confi-
dently drawn by that gentleman, I thought it right, for the interest
of scientific truth, to prepare some kind of answer ; as, however, on a
more attentive perusal, I find that you yourself appear implicitly to
adopt Captain Hutton's views, and actually use these wAds, ' We have
long been conscious of the error here so. well pointed out by Captain
Hutton, in common with every one who has visited the Himalayas,'' I feel
more inclined to address you, in the first instance, and to ask whether
you will publish a short reply which I meditate ; and whether your
note to Captain Hutton's paper was written after your own full and
careful examination of the subject, or merely on a genei'al kind of ac-
quiescence with the fact and opinions of your able contributor, who is
Ko well known and esteemed as a collector of scientific data ? Now I
am one who have visited the Himalaya on the western side ; I have
crossed the Borendo or Boorin Pass into the Buspa Valley, in Lower
Kanawar, returning into the Rewaien Mountains of Gburwal by the
Koopiu Pass; I have visited the source of the Jumna at Jumnootieej

SS2 COSMOS.

those of a purely physical nature, since it exercises no incon'
siderable degree of influence on the mode of life of numerous
tribes — the meteorological processes of the atmosphere being
the controUing causes on which depend the agricultural oi
pastoral pursuits of the inhabitants of extensive tracts of con-
tinents.

As the quantity of moisture in the atmosphere increases
with the temperature, this element, which is so important for
the whole organic creation, must vary with the hours of the
day, the seasons of the year, and the differences in latitude
and elevation. Our knowledge of the hygrometric relations
of the Earth's surface has been very materially augmented
of late years by the general application of August's psychrom-
eter, framed in accordance with the views of Dalton and
Daniell, for determining the relative quantity of vapor, or the

and, moving eastward, the sources of the Kalee or Mundaknee branch
cf the Ganges at Kadarnath ; of the Vishnoo Gunga, or Aluknunda, at
Buddrinath and Mana ; of the Pindur at the foot of the Great Peak
Nundidevi; of the Dhoulee branch of the Ganges, beyond Neetee, cross-
ing and recrossmg the pass of that name into Thibet ; of the Goree or
great branch of the Sardah, or Kalee, near Oonta Dhoora, beyond M*
lum. I have also, in my official capacity, made the settlement of the
Bhote Mehals of this province. My residence of more than six years
in the hills has thrown me constantly in the way of European and na-
tive travelers, nor have I neglected to acquire information from the re-
corded labors of others. Yet, with all this experience, I am prepared
to affirm that the perpetual snow-li?ie is at a higher elevation on the north-
ern slope of ' the Himalaya' than on the southern slope.

" The facts mentioned by Captain Hutton appear to me only to refer
to the northern sides of all mountains in these regions, and not to affect,
in any way, the reports of Captain Webb and others, on which Hum-
boldt formed his theory. Indeed, how can any facts of one observer in
one place falsify the facts of another observer in another place ? I will-
ingly allow that the north side of a hill retains the snow longer and
deeper than the south side, and this observation applies equally to
heights in Bhote ; but Humboldt's theory is on the question of the per-
petual snow-line, and Captain Hutton's references to Simla and Mus-
sooree, and otrier mountain sites, are out of place in this question, or
else he fights against a shadow, or an objection of his own creation.
In no part of his paper does he quote accui-ately the dictum which he
wishes to oppose."

If the mean altitude of the Thibetian highlands be 11,510 feet, they
admit of comparison with the lovely and fruitful plateau of Caxamarca
in Peru. But at this estimate they would still be 1300 feet lower than
the plateau of Bolivia at the Lake of Titicaca, and the causeway of the
town of Potosi. Ladak, as appears from Vigne's measurement, by de-
termining the boiling-point, is 9994 feet high. This is probably also
the altitude of H'Lassa (Yul-sung), a monastic city, which Chinesn
writers describe as the realm of pleasure, and which is surrounded l)y
vineyards. Must not these lie in deep valleys?

. HYGROMETRT. 333

condition of moisture of the atmosphere, by means of the dif-
ference of the dew ^^oint and of the temperature of the air.
Temperature, atmospheric pressure, and the direction of the
wind, are all intimately connected with the vivifying action
of atmospheric moisture. This influence is not, however, so
much a consequence of the quantity of moisture held in solu-
tion in different zones, as of the nature and frequency of the
precipitation which moistens the ground, whether in the form
of dew, mist, rain, or snow. According to the exposition made
by Dove of the law of rotation, and to the general views of
this distinguished physicist,* it would appear that, in our
northern zone, " the elastic force of the vapor is greatest with
a southwest, and least with a northeast wind. On the west-
ern side of the windrose this elasticity diminishes, while it in-
creases on the eastern side ; on the former side, for instance,
the cold, dense, and dry current of air repels the warmer,
lighter current containing an abundance of aqueous vapor,
while on the eastern side it is the former current which is
repulsed by the latter. The southwest is the Qquatorial cur-
rent, while the northeast is the sole prevailing polar current."
The agreeable and fresh verdure which is observed in many
trees in districts within the tropics, where, for five or seven
months of the year, not a cloud is seen on the vault of heaven,
and where no perceptible dew or rain falls, proves that the
leaves are capable of extracting water from the atmosphere
by a peculiar vital process of their own, which perhaps is not
alone that of producing cold by radiation. The absence of
rain in the arid plains of Cumana, Coro, and Ceara in North
Brazil, forms a striking contrast to the quantity of rain which
falls in some tropical regions, as, for instance, in the Havana,
where it would appear, from the average of six years' observ-
ation by Ramon de la Sagra, the mean annual quantity of
rain is 109 inches, equal to four or five times that which falls
at Paris or at Geneva. t On the declivity of the Cordilleras,

* See Dove, Meteorologische Vergleichung von Nordamerika und Eu-
ropa, in Schumacher's Jahrbuchfur 1841, s. 311 ; and his Meteorologische
Unlersuchungen, s. 140.

t The mean annual quantity of rain that fell in Paris between 1805
and 1822 was found by Arago to be 20 inches; in London, between
1812 and 1827, it was determined by Howard at 25 inches; while at
Geneva the mean of thirty-two years' observation was 30-5 inches, lu
Hindostan, near the coast, the quantity of rain is from 115 to 128 inches ;
and in the island of Cuba, fully 142 inches fell in the year 1821. With
regard to the distribution of the quantity of I'ain in Central Europe, at
different periods of the year, see the admirable researches of Gasparin,
Schouw, and Bravais, in the Bibliotkeque Universelle, t. xxxviii, p. 54

334 COSMOS.

the quantity ot rain, as well as the temperature, diminishei
with the increase in the elevation* My South Ameiican
fellow-traveler, Caldas, found that, at Santa Fe de Bogota,
at an elevation of almost 8700 feet, it did not exceed 37
inches, being consequently little more than on some parts of
the western shore of Europe. Boussingault occasionally ob-
served at Quito that Saussure's hygrometer receded to 26*-*
with a temperature of from 53^' 6 to 55°-4. Gay-Lussac
saw the same hygrometer standing at 25*^ '3 in his great aero-
static ascent in a stratum of air 7034 feet high, and with a
temperature of 39^-2. The greatest dryness that has yet
been observed on the surface of the globe in low lands is
probably that which Gustav Rose, Ehrenberg, and myself
found in Northern Asia, between the valleys of the Irtisch
and the Oby. In the Steppe of Platowskaja, after southwest
winds had blown for a long time from the interior of the Con-
tinent, with a temperature of 74*-*'7, we found the dew point
at 24*^. The air contained only yVo^hs of aqueous vapor. 1
The accurate observers Kamtz, Bravais, and Martins have
raised doubts during the last few years regarding the greater
dryness of the mountain air, which appeared to be proved by
the hygrometric measurements made by Saussure and my-
self in the higher regions of the Alps and the Cordilleras.
The strata of air at Zurich and on the Faulhorn, which can
not be considered as an elevated mountain when compared
with non-European elevations, furnished the data employed
in the comparisons made by these observers. $ In the tropical
region of the Paramos (near the region where snow begins to
fall, at an elevation of between 12,000 and 14,000 feet), some
species of large flowering myrtle-leaved alpine shrubs are al-
most constantly bathed in moisture ; but this fact does not
actually prove the existence of any great and absolute quan-
tity of aqueous vapor at such an elevation, merely affording

and 264; Tableau du Climat de V Italic, p. 76; and Martins's notes to
his excellent French translation of Kiimtz's Vorlesungen uber MeUorol-
ogie, p. 142.

* According to Boussingault (Economie Rurale, t. ii., p. 693), the
mean quantity of rain that fell at Marmato (latitude 5^ 27', altitude
4675 feet, and mean temperature 69°) in the years 1833 and 1834 was
64 inches, while at Santa Fe de Bogota (latitude 4° 36', altitude 8685
feet, and mean temperature 58°) it only amounted to 39^^ inches.

t For the particulars of this observation, see va.y Asie Centrale, t. iii.
p. 85-89 and 567 ; and regarding the amount of vapor in the atmo»
phere in the lowlands of tropical South America, consult my R€laL
Hist., t. i., p. 242-248; t. ii., p. 45, 164.

t Kamtz, Vorlesungen uber Meteorologie, s. 117.

ATMOSPHERIC ELECTRICITY. 335

an evidence of the frequency of aqueous precipitation, in like
manner as do the frequent mists with which the lovely pla-
teau of Bogota is covered. Mists arise and disappear several
times in the course of an hour in such elevations as these, and
with a calm state of the atmosphere. These rapid alterna
tions characterize the Paramos and the elevated plains of the
chain of the Andes.

. The electricity of the atmosphere, whether considered in
the lower or in the upper strata of the clouds, in its silent
problematical diurnal course, or in the explosion of the light-
ning and thunder of the tempest, appears to stand in a mani-
fold relation to all phenomena of the distribution of heat, of
the pressure of the atmosphere and its disturbances, of hydro-
meteoric exhibitions, and probably, also, of the magnetism of
the external crust of the earth. It exercises a powerful in
fluence on the whole animal and vegetable world ; not mere-
ly by meteorological processes, as precipitations of aqueous va-
por, and of the acids and ammoniacal compounds to which it
gives rise, but also directly as an electric force acting on the
nerves, and promoting the circulation of the organic juices.
This is not a place in which to renew the discussion that has
been started regarding the actual source of atmospheric elec-
tricity when the sky is clear, a phenomenon that has altern
ately been ascribed to the evaporation of impure fluids im-
pregnated with earths and salts,* to the growth of plants,! or
to some other chemical decompositions on the surface of the
earth, to the unequal distribution of heat in the strata of the
air,| and, finally, according to Peltier's intelligent researches,^
to the agency of a constant charge of negative electricity in
the terrestrial globe. Limiting itself to results yielded by
electrometric observations, such, for instance, as are furnished
by the ingenious electro-magnetic apparatus first proposed by
CoUadon, the physical description of the universe should
merely notice the incontestable increase of intensity in the
general positive electricity of the atmosphere, || accompanying
an increase of altitude and the absence of trees, its daily va-
riations (which, according to Clark's experiments at Dublin,

* Regarding the conditions of electricity from evaporation at high,
temperatures, see Peltier, in the Annates de Chimie, t. Ixxv., p. 330

t Pouillet, in the Annates de Chimie, t. xxxv., p. 405.

X De la Rive, in his admirable Essai Historique sur V Electriciti, p.
140.

$ Peltier, in the Coviptes lietidus de V Acad, des Sciences, t. xii., p
J07 ; Becquerel, TraiU de V Electricit6 et du MagnUisme, t. iv., p. 107

U Duprez. Sur V ElectriciU de VAir (Bruxeres, 1844), p. 56-61

3^>J COSMOS.

take place at more complicated periods than those found by
Saussure and myself), and its variations in the different
seasons of the year, at different distances from the equator,
and in the difierent relations of continental or oceanic sur
face. ^

The electric equilibrium is less frequently disturbed where
the aerial ocean rests on a liquid base than where it impends
over the land ; and it is very striking to observe how, in ex-
tensive seas, small insular groups afiect the condition of the
atmosphere, and occasion the formation of storms. In fogs,
and in the commencement of falls of snow, I have seen, in a
long series of observations, the previously permanent positive
electricity rapidly pass into the negative condition, both on
the plains of the colder zones, and in the Paramos of the Cor-
dilleras, at elevations varying from 11,000 to 15,000 feet.
The alternate transition was precisely similar to that indica-
ted by the electrometer shortly before and during a storm. =^
When the vesicles of vapor have become condensed into clouds,
having definite outHnes, the electric tension of the external
surface will be increased in proportion to the amount of elec-
tricity which passes over to it from the separate vesicles of
vapor. t Slate-gray clouds are charged, according to Peltier's
experiments at Paris, with negative, and white, red, and or-
ange-colored clouds with positive electricity. Thunder clouds
not only envelop the highest summits of the chain of the An-
des (I have myself seen the electric effect of lightning on one
of the rocky pinnacles which project upward of 15,000 feet
above the crater of the volcano of Toluca), but they have also
been observed at a vertical height of 26,650 feet over the low

* Humboldt, Relation Historique, t. iii., p. 318. I here only refer
to those of my experiments in which the three-foot metallic conductor
of Saussure's electrometer was neither moved upward nor downward,
nor, according to Volta's proposal, armed with burning sponge. Those
of my readers who are well acquainted with the qucestiones vexatee of
atmospheric electricity will understand the grounds for this limitation.
Respecting the formation of storms in the tropics, see my Ril. Hist., t.
ii., p. 45 and 202-209.

t Gay-Lussac, in the Annales de Chimie et de Physique, t. viii., p. 167.
In consequence of the discordant views of Lam&, Becquerel, and Pel-
tier, it is difficult to come to a conclusion regarding the cause of the
specific distribution .of "electricity in clouds, some of which have a pos-
itive, and others a negative tension. The negative electricity of the
air, which near high water-falls is caused by a disintegration of the
drops of water — a fact originally noticed by Tralles, and confirmed by
myself in various latitudes^s very remarkable, and is suflBciently in-
tense to produce an appreciable efiect on a delicate electrometer at a
distance of 300 or 400 feet.

ATMOSPHERIC ELECTRICITY. 3&-|

lands in the temperate zone.* Sometimes, however, the
stratum of cloud from which the thunder proceeds sinks to a
distance of 5000, or, indeed, only 3000 feet above the plain.

According to Arago's investigations — the most comprehen-
sive that we possess on this difficult branch of meteorology —
the evolution of hght (lightning) is of three kinds — zigzag,
and sharply defined at the edges ; in sheets of light, illumin-
ating a whole cloud, which seems to open and reveal the light
within it ; and in the form of fire-balls.t The duration of the
two first kinds scarcely continues the thousandth part of a
second ; but the globular lightning moves much more slowly
remaining visible for several seconds. Occasionally (as is
proved by the recent observations, which have confirmed the
'description given by Nicholson and Beccaria of this phenom-
enon), isolated clouds, standing high above the horizon, con-
tinue uninterruptedly for some time to emit a luminous ra-
diance from their interior and from their margins, although
there is no thunder to be heard, and no indication of a storm ;
in some cases even hail-stones, drops of rain, and flakes of snow
have been seen to fall in a luminous condition, when the phe-
nomenon was not preceded by thunder. In the geographical
distribution of storms, the Peruvian coast, which is not visited
by thunder or lightning, presents the most striking contrast to
the rest of the tropical zone, in which, at certain seasons of
the year, thunder-storms occur almost daily, about four or five
hours after the sun has reached the meridian. According to
the abundant evidence collected by Arago:}: from the testimony
of navigators (Scoresby, Parry, Ross, and Franklin), there can
be no doubt that, in general, electric explosions are extremely
rare in high northern regions (between 70^ and 75° latitude).

The meteorological 'portion of the descriptive history of na
ture which we are now concluding shows that the processes
of the absorption of light, the liberation of heat, and the va-
riations in the elastic and electric tension, and in the hygro-
metric condition of the vast aerial ocean, are all so intimate-
ly connected together, that each individual meteorological
process is modified by the action of all the others. The com-

* Arago, in the Annuaire du Bureau des Longitudes pour 1838, p. 246.
t Arago, op. cit., p. 249-266. (See, also, p. 268-279.)
t Arago, op. cit., p. 388-391. The learned academician Von Baer,
who has done so much for the meteorology of Northern Asia, has not
taken into consideration the extreme rarity of storms in Iceland and
Greenland ; he h\3 only remarked (Bulletin de VAcademie de St. Piters
bourg, 1839, Mai) that iu Nova Zembla and Spitzbergen it is sometimea
ieard to thunder.

Vol. I.— P

338 COSMOS.

plicated nature of these disturbing causes (wliich involuntarily
remind us of those which the near and especially the smallest
cosmical bodies, the satellites, comets, and shooting stars, are
subjected to in their course) increases the difficulty of giving a
full explanation of these involved meteorological phenomena,
and likewise limits, or wholly precludes, the possibility of that
predetermination of atmospheric changes which would be so
important for horticulture, agriculture, and navigation, no less
than for the comfort and enjoyment of life. Those who place
the value of meteorology in this problematic species of predic-
tion rather than in the knowledge of the. phenomena them-
selves, are firmly convinced that this branch of science, on ac-
count of which so many expeditions to distant mountainous
regions have been undertaken, has not made any very consid-
erable progress for centuries past. The confidence which they
refuse to the physicist they yield to changes of the moon, and
to certain days marked in the calendar by the superstition of
a by-gone age.

" Great local deviations from the distribution of the mean
temperature are of rare occurrence, the variations being in
general uniformly distributed over extensive tracts of land.
The deviation, after attaining its maximum at a certain poir.t,
gradually decreases to its limits ; when these are passed, how-
ever, decided deviations are observed in the opposite direction.
Similar relations of weather extend more frequently from south
to north than from west to east. At the close of the year 1829
(when I had just completed my Siberian journey), the maxi-
mum of cold was at Berlin, while North America enjoyed an
unusually high temperature. It is an entirely arbitrary as-
sumption to believe that a hot summer succeeds a severe win-
ter, and that a cool summer is preceded by a mild winter."
Opposite relations of weather in contiguous countries, or in
two corn-growing continents, give rise to a beneficent equali-
zation in the prices of the products of the vine, and of agricul-
tural and horticultural cultivation. It has been justly re-
marked, that it is the barometer alone which indicates to us
the changes that occur in the pressure of the air throughout
all the aerial strata from the place of observation to the ex-
tremest confines of the atmosphere, while* the thermometer
and psychrometer only acquaint us with all the variations oc-
curring in the local heat and moisture of the lower strata of

* Kamtz, in Schumacher's Jahrbuck fur 1838, s. 285. Regarding
the opposite distribution of heat in the east and the west of Europe and
North America, see Dove, Repertorium der Physik, bd. iii., 8. 392-395

ORGANIC LIFE. 339

air in contact with the ground. The simultaneous thermic
and hygrometric modifications of the upper regions of the air
can only be learned (when direct observations on mountain
stations or aerostatic ascents are impracticable) from hypo-
thetical combinations, by making the barometer serve both as
a thermometer and an hygrometer. Important changes of
weather are not owing to merely local causes, situated at the
place of observation, but are the consequence of a disturbance
in the equilibrium of the aerial currents at a great distance
from the surface of the Earth, in the higher strata of the at-
mosphere, bringing cold or warm, dry or moist air, rendering
the sky cloudy or serene, and converting the accumulated
masses of clouds into light feathery cirri. As, therefore, the
inaccessibility of the phenomenon is added to the manifold
nature and complication of the disturbances, it has always
appeared to me that meteorology must first seek its founda-
tion and progress in the torrid .zone, where the variations of
the atmospheric pressure, the course of hydro-meteors, and
the phenomena of electric explosion, are all of periodic occur-
rence.

As we have now passed in review the whole sphere of in-
organic terrestrial life, and have briefly considered our planet
with reference to its form, its internal heat, its electro-mag-
netic tension, its phenomena of polar light, the volcanic reac-
tion of its interior on its variously composed solid crust, and,
lastly, the phenomena of its two-fold envelopes — the aerial and
liquid ocean — we might, in accordance with the older method
of treating physical geography, consider that we had com-
pleted our descriptive history of the globe. But the nobler
aim I have proposed to myself, of raising the contemplation
of nature to a more elevated point of view, would be defeated,
and this dehneation of nature would appear to lose its most
attractive charm, if it did not also include the sphere of or-
ganic life in the many stages of its typical development. The
idea of vitality is so intimately associated with the idea of the
existence of the active, ever-blending natural forces which an-
imate the terrestrial sphere, that the creation of plants and
animals is ascribed in the most ancient mythical representa-
tions of many nations to these forces, while the condition of
the surface of our planet, before it was animated by vital
forms, is regarded as coeval with the epoch of a chaotic
conflict of the struggling elements. But the empirical do-
main of objective contemplation, and the delineation of our
planet in its present condition, do not include a consideration

340 COSMOS.

of the mysterious and insoluble problems of origin and exist-
ence.

A cosmical history of the universe, resting upon facts as its
basis, has, from the nature and limitations of its sphere, neces-
sarily no connection with the obscure domain embraced by a
history of organisms* if we understand the word history in
its broadest sense. It must, however, be remembered, that
the inorganic crust of the Earth contains within it the same
elements that enter into the structure of animal and vegeta-
ble organs. A physical cosmography would therefore be in

* The history of plants, which Endlicher and Unger have described
in a most masterly manner {Grundzuge der Botanik, 1843, s. 449-468),
I myself separated from the geography of plants half a century ago
In the aphorisms appended to my Subterranean Flora, the following
passage occurs : " Geognosia naturam animantera et inanimam vel, ut
vocabulo minus apto, ex antiquitate saltem haud petito, utar, corpora
organica Jeque ac inorganica considerat. Sunt enim tria quibus absol
vitur capita : Geographia oryctologica quam simpliciter Geognosiam vel
Geologiam dicunt, virque acutissimus Weraerus egregie digessit ; Geo-
graphia zoologica, cujus doctrinae fundamenta Zimmermannus et Tre-
viranus jecenmt; et Geographia plantarum quam aequales nostri diu in-
tactam reliquerunt. Geographia plantarum vincula et cognationem
tradit, quibus omnia vegetabilia inter se counexa sint, terrse tractus
quos teneant, in aerem atmosphaericum quae sit eorum vis ostendit, saxa
atque rupes quibus potissimum algarum primordiis radicibusque destru-
antur docet, et quo pacto in telluris superficie humus nascatur, com-
memorat. Est itaque quod difFerat inter Geognosiam et Physiographiam,
historia naluralis perperam nuncupatam quum Zoognosia, Phytognosia,
et Oryctognosia, quae quidem omnes in naturae investigatione versautur,
non nisi singulorum animalium, plantarum, rerum metallicamm vel
(venia sit verbo) fossilium formas, anatomen, vires scrutantur. Historia
Telluris, Geognosiae magis quam Physiographiae affinis, nemini adhuc
tentata, plantarum animaliumque genera orbem inhabitantia primaevum,
migrationes eorum compluriumque interitum, ortum quem monies,
valles, saxorum strata et venae metalliferae ducunt, aerem, mutatis tem-
porum vicibus, mode purum, mode vitiatum, terrae superficiem humo
plantisque paulatim obtectam, fluminum inundantium impetu denuo
uudatam, iterumque siccatam et gramine vestitam commemorat. Igi-
tur Historia zoologica, Historia plantarum et Historia oryctologica, quae
non nisi pristinum orbis terrae statum indicant, a Geognosia probe dis-
iinguendafi." — Humboldt, Flora FHburgensis Subterranea, cui acceduni
Aphorismi ex Physiologia Chemica Plantarum, 1793, p. ix.-x. Respect-
ing the " spontaneous motion," which is referred to in a subsequent
part of the text, see the remarkable passage in Aristotle, De CcrIo, ii.,
2, p. 284, Bekker, where the distinction between animate and inanimate
bodies is made to depend on the internal or external position of the
seat of the determining motion. " No movement," says the Stagirite,
" proceeds from the vegetable spirit, because plants are buried in a
Btill sleep, from which nothing can arouse them" (Aristotle, De General.
Animal., v. i., p. 778, Bekker); and again, "because plants have no
desires which ircite them to spontaneous motion." ( Arist., De Somno
et Vigil., cap. i., p. 455, Bekker.)

MOTION IN PLANTS. 34 i

complete if it were to omit a consideration of these forces, and
of the substances which enter into soUd and fluid combina*
tions in organic tissues, under conditions which, from our igno-
rance of their actual nature, we designate by the vague term
of vital forces, and group into various systems, in accordance
with more or less perfectly conceived analogies. The nat-
ural tendency of the human mind involuntarily prompts us
to follow the physical phenomena of the Earth, through all
their varied series, until we reach the final stage of the mor-
phological evolution of vegetable forms, and the self-determin-
ing powers of motion in animal organisms. And it is by these
links that the geography of organic beings — of plants and
animals — is connected with the delineation of the inorganic
phenomena of our terrestrial globe.

Without entering on the difficult question of spontaneous
motion, or, in other words, on the difference between vegeta-
ble and animal life, we would remark, that if nature had en-
dowed us with microscopic powers of vision, and the integu-
ments of plants had been rendered perfectly transparent to
our eyes, the vegetable world would present a very different
aspect from the apparent immobility and repose in which it
is now manifegjted to our senses. The interior portion of the
cellular structure of their organs is incessantly animated by
the most varied currents, either rotating, ascending and de-
scending, ramifying, and ever changing their direction, as
manifested in the motion of the granular mucus of marine
plants (Naiades, CharacesB, Hydrocharidse), and in the hairs of
phanerogamic land plants ; in the molecular motion first dis-
covered by the illustrious botanist Robert Brown, and which
may be traced in the ultimate portions of every molecule of
matter, even when separated from the organ ; in the gyratorv
currents of the globules of cambium {cyclosis) circulating in
their peculiar vessels ; and, finally, in the singularly articula-
ted self-unrolling filamentous vessels iii the antheridia of the
chara, and in the reproductive organs of liverworts and algae,
in the structural conditions of which Meyen, unhappily too
early lost to science, believed that he recognized an analogy
with the spermatozoa of the animal kingdom.* If to these

* [*' In certain parts, probably, of all plants, are found peculiar spiral
filaments, having a striking resemblance to the spermatozoa of animals.
They have been long know^n in the organs called the antheridia of
mosses, HepaticjE, and Characea), and have more recently been dis-
covered in peculiar cells on the germinal frond of ferns, and on the
very young leaves of the buds of Phanerogamia. They are found in
Deculiar cells, and when these are placed in vv^ater they are torn by the

342 COSMOS.

manifold currents and gyratory movements we add the pho
nomena of endosmosis, nutrition, and growth, we shall have
some idea of those forces which are ever active amid the ap
parent repose of vegetable life.

Since I attempted in a former work, Andchten der Natur
(Views of Nature), to delineate the universal diffusion of life
over the whole surface of the Earth, in the distribution of
organic forms, both with respect to elevation and depth, our
knowledge of this branch of science has been most remarkably
increased by Ehrenberg's brilliant discovery " on microscopic
life in the ocean, and in the ice of the polar regions" — a dis-
covery based, not on deductive conclusions, but on direct ob-
servation. The sphere of vitality, we might almost say, the
horizon of life, has been expanded before our eyes. " Not
only in the polar regions is there an uninterrupted develop-
ment of active microscopic life, where larger animals can no
longer exist, but we find that the microscopic animals collect-
ed in the Antarctic expedition of Captain James Ross exhibit
a remarkable abundance of unknown and often most beautiful
forms. Even in the residuum obtained from the melted ice,
swimming about in round fragments in the latitude of 70° 10',
there were found upward of fifty species of silicious-shelled
Polygastria and Coscinodiscse with their green ovaries, and
therefore living and able to resist the extreme severity of the
cold. In the Gulf of Erebus, sixty-eight silicious-shelled Poly-
gastria and Phytolitharia, and only one calcareous-shelled Poly-
thalamia, were brought up by lead sunk to a depth of from
1242 to 1620 feet."

The greater number of the oceanic microscopic forms hith-
rTto discovered have been silicious-shelled, although the anal-
ysis of sea water does not yield silica as the main constituent,
and it can only be imagined to exist in it in a state of suspen-
sion. It is not only at particular points in inland seas, or in
the vicinity of the land, that the ocean is densely inhabited
by living atoms, invisible to the 'naked eye, but samples of

filament, which commences an active spiral motion. The signification
of these organs is at present quite unknown ; they appear, from the
researches of Nageli, to resemble the cell mucilage, or proto-plasma,
in composition, and are developed from it. Schleiden regards them aa
mere mucilaginous deposits, similar to those connected with the circu-
lation in cells, and he contends that the movement of these bodies ia
water is analogous to the molecular motion of small particles of organic
and inorganic substances, and depends on mechanical causes." — Outlines
of Structural end Physiological Botany, by A. Henfrey, F.L.S., &c.,
1846, p. 23.1— :rr

UNIVERSALITY OF ANIMAL LIFE. 343

water taken ap by Schayer on his return from Van Diemen's
Land (south of the Cape of Good Hope, in 57° latitude, and
under the tropics in the Atlantic) show that the ocean in its
ordinary condition, without any apparent discoloration, con-
tains numerous microscopic moving organisms, which bear no
resemblance to the swimming fragmentary silicious filaments
of the genus ChsBtoceros, similar to the Oscillatoriae so common
in our fresh waters. Some few Polygastria, which have been
found mixed with sand and excrements of penguins in Cock-
burn Island, appear to be spread over the whole earth, while
others seem to be peculiar to the polar regions. =^

We thus find from the most recent observations that ani-
mal life predominates amid the eternal night of the depths of
ocean, while vegetable life, which is so dependent on the pe-
riodic action of the solar rays, is most prevalent on continents.
The mass of vegetation on the Earth very far exceeds that
of animal organisms ; for what is the volume of all the large
living Cetacea and Pachydermata when compared with the
thickly-crowded colossal trunks of trees, of from eight to twelve
feet in diameter, which fill the vast forests covering the trop-
ical region of South America, between the Orinoco, the Ama-
zon, and the Rio da Madeira ? And although the character
of different portions of the earth depends on the combination
of external phenomena, as the outlines of mountains — the
physiognomy of plants and animals — the azure of the sky — .
the forms of the clouds — and the transparency of the atmos-
phere^— it must still be admitted that the vegetable mantle
with which the earth is decked constitutes the main feature
of the picture. Animal forms are inferior in mass, and their
powers of motion often withdraw them from our sight. The

* See Ehrenberg's treatise Ueber das kleinste Leben im Ocean, read
before the Academy of Science at Berlin on the 9th of May, ]844.

[Dr. J. Hooker found Diatomace.e in countless numbers between the
parallels of 60"^ and 80° south, where they gave a color to the sea, and
also to the icebergs floating in it. The death of these bodies in the
South Arctic Ocean is producing a submarine deposit, consisting en-
tirely of the silicious particles of which the skeletons of these vegeta-
bles are composed. This deposit exists on the shores of Victoria Land
and at the base of the volcanic mountain Erebus. Dr. Hooker account-
ed for the fact that the skeletons of Diatoraacese had been found in the
lava of volcanic mountains, by referring to these deposits at Mount
Erebus, which lie in such a position as to render it quite possible that
the skeletons of these vegetables should pass into the lower fissures of
the mountain, and then passing into the stream of lava, be thrown out,
Unacted upon by the heat to which they have been exposed. See Dr.
Hooker's Paper, read before the British Association at Oxford, July,
l8i7.-\—Tr.

344 COSMOS.

vegetable kingdom, on the contrary, acts upon our imagination
by its continued presence and by the magnitude of its forms ;
for the size of a tree indicates its age, and here alone age ia
associated with the expression of a constantly renewed vigor.*
In the animal kingdom (and this knowledge is also the result
of Ehrenberg's discoveries), the forms which we term micro-
scopic occupy the largest space, in consequence of their rapid
propagation.! The minutest of the Infusoria, the Monadidse,
have a diameter which does not exceed goVo^^ ^f a line, and
yet these silicious-shelled organisms form in humid districts
subterranean strata of many fathoms in depth.

The strong and beneficial influence exercised on the feelings
of mankind by the consideration of the diffusion of life through-
out the realms of nature is common to every zone, but the im-
pression thus produced is most powerful in the equatorial re-
gions, in the land of palms, bamboos, and arborescent ferns,
where the ground rises from the shore of seas rich in moUusca
and corals to the limits of perpetual snow. The local distri-
bution of plants embraces almost all heights and all depths
Organic forms not only descend into the interior of the earth
where the industry of the miner has laid open extensive ex
cavations and sprung deep shafts, but I have also found snow
white stalactitic columns encircled by the delicate web of an
Usnea, in caves where meteoric water could alone penetrate
through fissures. Podurellse penetrate into the icy crevices of
the glaciers on Mount Rosa, the Grindelwald, and the Upper
Aar ; the Chionsea araneoides described by Dalman, and the
microscopic Discerea nivalis (formerly known as Protococ-
cus), exist in the polar snow as well as in that of our high
mountains. The redness assumed by the snow after lying on
the ground for some time was known to Aristotle, and was
probably observed by him on the mountains of Macedonia. J

* Humboldt, Ansichten der Natur (2te Ausgabe, 1826), bd. ii., s. 21.

t On multiplication by spontaneous division of the mother-corpuscle
and intercalation of new substance, see Ehrenberg, Von den jetzt leben-
den Tkierarten der Kreidebildung, in the Abhandl. der Berliner Akad.
der Wis$., 1839, s. 94. The most powerful productive faculty in na-
ture is that manifested in the Vorticellae. Estimations of the greatest
possible development of masses will be found in Ehrenberg's great
work, Die Infusionsthierchen ah voUkommne Organismen, 1838, s. xiii.,
xix., and 244. " The Milky Way of these organisms comprises the
genera Monaa Vibrio, Bacterium, and Bodo." The universality of life
is so profusely distributed throughout the whole of nature, that the small-
er Infusoria live as parasites on the larger, and are themselves inflabit*
ed by others, s. 194, 211, and 512.

t Aristot.. Hist. Animal.^ v. xix., p. 552, Bekk.

UNIVERSALITY OF ANIMAL LIFE. 345

While, on the loftiest summits of the Alps, only Lecidese,
ParmeliaB, and UmbilicariaB cast their colored but scanty
eovering over the rocks, exposed by the melted snow, beauti-
ful phanerogamic plants, as the Culcitiura rufescens, Sida
pinchinchensis, and Saxifraga Boussingaulti, are still found
to flourish in the tropical region of the chain of the Andes, at
an elevation of more than 15,000 feet. Thermal springs con-
tain small insects (Hydroporus thermalis), Gallionellae, Oscilla-
toria, and Confervse, while their waters bathe the root-fibers oi
phanerogamic plants. As air and water are animated at dif-
ferent temperatures by the presence of vital organisms, so like-
wise is the interior of the different portions of animal bodies.
Animalcules have been found in the blood of the frog and the
salmon ; according to Nordmann, the fluids in the eyes of fishes
are often filled with a worm that lives by suction (Diplosto-
mum), while in the gills of the bleak the same observer has
discovered a remarkable double animalcule (Diplozoon para-
doxum), having a cross-shaped form with two heads and two
caudal extremities.

Although the existence of meteoric Infusoria is more than
doubtful, it can not be denied that, in the same manner as the
pollen of the flowers of the pine is observed every year to fall
from the atmosphere, minute infusorial animalcules may like-
wise be retained for a time in the strata of the air, after hav-
ing been passively borne up by currents of aqueous vapor.*
This circumstance merits serious attention in reconsidering
the old discussion respecting spontaneous generation, \ and the

* Ehrenberg, op. cit., s. xiv., p. 122 and 493. This rapid multiplica
tion of microscopic organisms is, in the case of some (as, for instance,
in wheat-eels, wheel-animals, and water-bears or tardigrade animal-
cules), accompanied, by a remarkable tenacity of life. They have been
seen to come to life from a state of apparent death after being dried,
for twenty-eight days in a vacuum with chloride of lime and sulphuric
acid, and after being exposed, to a heat of 248°. See the beautiful ex-
periments of Doyere, in M6m. sur les Tardigrades et sur leur propriH6
de revenir a la vie, 1842, p. 119, 129, 131, 133. Compare, also, Ehren
berg, s. 492-496, on the revival of animalcules that had been dried
during a space of many years.

t On the supposed. " primitive transformation" of organized, or unor
ganized. matter into plants and animals, see Ehrenberg, in Poggen-
dorf's Annalen der Physik, bd. xxiv., s. 1-48, and also his Infusions-
thiercken, s. 121, 525, and Joh. MUUer, Physiologic des Menschen (4te
Aufl., 1844), bd. i., s. 8-17. It appears to me worthy of notice that one
of the early fathers of the Church, St. Augustine, in treating of the
question how islands may have been covered, with new animals and
plants after the flood, shows himself in no way disinclined to adopt the
view of the so-callp-l "spautaueous generation" (generatio (Eqnivoca,

P 2

846

COSMOS.

more so, as Ehrenberg, as I have already remarked, has dis-
covered that the nebulous dust or sand which mariners often
encounter in the vicinity of the Cape Verd Islands, and even
at a distance of 380 geographical miles from the African shore,
contains the remains of eighteen species of silicious-shelled pol-
ygastric animalcules.

Vital organisms, whose relations in space are compns^d un-
der the head of the geography of plants and animals, may be
considered either according to the difierence and relative num-
bers of the types (their arrangement into genera and species),
or according to the number of individuals of each species on a
given area. In the mode of life of plants as in that of ani-
mals, an important difference is noticed ; they either exist in
an isolated state, or live in a social condition. Those species
of plants which I have termed social* uniformly cover vast
extents of land. Among these we may reckon many of the
marine Algse — Cladonise and mosses, which extend over the
desert steppes of Northern Asia — grasses, and cacti growing

tpontanea aut primaria). " If," says he, " animals liave not been
brought to remote islands by angels, or perhaps by inhabitants of con
tinents addicted to the chase, they must have been spontaneously pro-
duced upon the earth ; although here the question certainly arises, to
what purpose, then, were animals of all kinds assembled in the ark?"
" Si e terra exortte sunt (besticB) secundum originem primam, quando
dixit Dens : Producai terra animam vivam ! multo clarius apparet, non
tam reparandorum animalium causa, quam figurandarum variarum gen-
tium (?) propter ecclesise sacramentum in area fuisse omnia genera, si in
insulis quo trausire non possent, multa animalia terra produxit." Augus-
tinus, De Civitate Dei, lib. xvi., cap. 7 ; Opera, ed. Monach. Ordinig S.
Benedicti, t. vii., Venet., 1732, p. 422. Two centuries before the time of
the Bishop of Hippo, we find, by extracts from Trogus Pompeius, that
the generatio primaria was brought forward in connection with the
earliest drying up of the ancient world, and of the high table-land ol
Asia, precisely in the same manner as the terraces of Paradise, in the
theory of the great Linnaeus, and in the visionary hypotheses entertain-
ed in the eighteenth century regarding the fabled Atlantis : " Quod si
omnes quondam terras submersae profundo fuerunt, profecto editissi-
mam quamque partem decurrentibus aquis primum detectam ; humil-
limo autem solo eandem aquam diutissime immoratam, et quanto prior
quaeque pars terrarum siccata sit, tanto prius animalia generare coepisse.
Porro Scythiam adeo editiorem omnibus terris esse ut cuncta flumina
ibi nata in MjEOtium, turn deinde in Ponticum et iEgyptium mare de-
currant." — Justinus, lib. ii., cap. 1. The erroneous supposition that the
land of Scythia is an elevated table-land, is so ancient that we meet
with it most clearly expressed in Hippocrates, De ^re et Aquis, cap.
6, $ 96, Coray. ''Scythia," says he, "consists of high and naked
plains, which, without being crowned with mountains, ascend higher
and higher toward the north."

* Humboldt, Aphorismi ex Physiolcgia Chemicr Pl^t^arum, in the
Flora Fribergensis Subterranea, 1793, p. 178.

GEOGRAPHY OF PLANTS. 347

together like the pipes of an organ — Avicenniae and mangroves
in the tropics — and forests of Coniferse and of birches in the
plains of the Baltic and in Siberia. This mocle of geographical
distribution determines, together with the individual form of
the vegetable world, the size and type of leaves and floAvers,
in fact, the principal physiognomy of the district ;* its charac-
ter being but little, if at all, influenced by the ever-moving
forms of animal life, which, by their beauty and diversity, so
powerfully affect the feelings of man, whether by exciting the
sensations of admiration or horror. Agricultural nations in-
crease artificially the predominance of social plants, and thus
augment, in many parts of the temperate and northern zones,
the natural aspect of uniformity ; and while their labors tend
to the extirpation of some wild plants, they likewise lead to
the cultivation of others, which follow the colonist in his most
distant migration. The luxuriant zone of the tropics offers
the strongest resistance to these changes in the natural distri-
bution of vegetable forms.

'Observers who in short periods of time have passed over
vast tracts of land, and ascended lofty mountains, in which
climates were ranged, as it were, in strata one above another,
must have been early impressed by the regularity with which
vegetable forms are distributed. The results yielded by tlieir
observations furnished the rough materials for a science, to
which no name had as yet been given. The same zones or
regions of vegetation which, in the sixteenth century. Cardinal
Bembo, when a youth,! described on the declivity of iEtna,
were observed on Mount Ararat by Tournefort. He ingen-
iously compared the Alpine flora with the flora of plains situ-
ated in different latitudes, and was the first to observe the in-
fluence exercised in mountainous regions, on the distribution
of plants by the elevation of the ground above the level of
the sea, and by the distance from the poles in flat countries.
Menzel, in an inedited work on the flora of Japan, accidental-
ly made use of the term geography of plants ; and the same
expression occurs in the fanciful but graceful work of Ber-
nardin de St. Pierre, Etudes de la Nature. A scientific treat-
ment of the subject began, however, only when the geography
of plants was intimately associated with the study of the dis-

* On the physiognomy of plants, see Humboldt, Ansichten der Natur,
bd. ii., 8. 1-125.

+ ^tna Dialogus. Opuscula, Basil., 1556, p. 53, 54. A very beauti-
ful geography of the plants of Mount ^tna has recently been published
by Fhilippi. See Linncea, 1832, s. 733.

348 cosMoa.

tribution of heat over the surface of the earth, and when the
arrangement of vegetable forms in natural families admitted
of a numerical estimate being made of the different forms
which increase or decrease as we recede from the equator to-
ward the poles, and of the relations in which, in different part?
of the earth, each family stood with reference to the whole
mass of phanerogamic indigenous plants of the same region.
I consider it a happy circumstance that, at the time during
which I devoted my attention almost exclusively to botanical
pursuits, I was led by the aspect of the grand and strongly
characterized features of tropical scenery to direct my investi-
gations toward these subjects.

The study of the geographical distribution of animals, re-
garding which Buffon first advanced general, and, in most
instances, very correct views, has been considerably aided in
its advance by the progress made in modern times in the
geography of plants. The curves of the isothermal lines, and
more especially those of the isochimenal lines, correspond with
the limits which are seldom passed by certain species of plants,
and of animals which do not wander far from their fixed hab-
itation, either with respect to elevation or latitude.* The

* [The following valuable remarks by Professor Forbes, on the cor-
respondence existing between the distribution of existing faunas and
floras of the British Islands, and the geological changes that have affect-
ed their area, will be read with much interest ; they have been copied,
by the author's permission, from the Survey Report, p. 16 :

" If the view I have put forward respecting the origin of the flora of
the British mountains be true — and every geological and botanical prob«
ability, so far as the area is concerned, favors it — then must we endeav-
or to find some more plausible cause than any yet shown for the pres-
ence of numerous species of plants, and of some animals, on the higher
parts of Alpine ranges in Europe and Asia, specifically identical with
animals and plants indigenous in regions very far north, and not found
in the intermediate lowlands. Tournefort first remarked, and Hum-
boldt, the great organizer of the science of natural history geography,
demonstrated, that zones of elevation on mountains correspond to par
allels of latitude, the higher with the more northern or southern, as the
case might k-i. It is well known that this correspondence is recogniz-
ed in the general /ac£es of the flora and fauna, dependent on generic
correspondences, specific representatives, and, in some cases, specific
identities. But when announcing and illustrating the law that climatal
zones of animal and vegetable life are mutually repeated or represented
by elevation and latitude, naturalists have not hitherto sufficiently (if
at all) distinguished between the evidence of that law, as exhibited by
representative species and by identical. In reality, the former essen-
tially depend on the law, the latter being an accident not necessarily
dependent upon it, and which has hitherto not been accounted for. In
the case of the Alpine flora of Britain, the evidence of the activity of
the lav» , and the inHuence of the accident, are inseparable, the law bo*

FLORAS OF DIFFERENT COUNTRIES. 349

elk, for instance, lives in the Scandinavian peninsula, almost
ten degrees further north than in the interior of Siberia, where
the line of equal winter temperature is so remarkably concave,
Plants migrate in the germ ; and, in the case of many species,
the seeds are furnished with organs adapting them to be con-
veyed to a distance through the air. When once they have
taken root, they become dependent on the soil and on the
strata of air surrounding them. Animals, on the contrary, can
at pleasure migrate from the equator toward the poles ; and
this they can more especially do where the isothermal lines
are much inflected, and where hot summers succeed a great
degree of winter cold. The royal tiger, which in no respect
differs from the Bengal species, penetrates every summer into

ing maintained by a transported flora, for the transmission of which I
have shown we can not account by an appeal to unquestionable geo-
logical events. In the case of the Alps and Carpathians, and some other
mountain ranges, We find the law maintained partly by a representa-
tive flora special in its region, i. e., by specific centers of their own,
aad partly by an assemblage more or less limited in the several ranges
of identical species, these latter in several cases so numerous that or-
dinary modes of transportation now in action can no more account for
their presence than they can for the presence of a Norwegian flora on
the British mountains. Now I am prepared to maintain that the same
means which introduced a sub-Arctic (now mountain) flora into Britain,
acting at the same epoch, originated the identity, as far as it goes, of
the Alpine floras of Middle Europe and Central Asia; for, now that we
know the vast area swept by the glacial sea, including almost the whole
of Central and Northern Europe, and belted by land, since greatly up-
lifted, which then presented to the water's edge those climatal condi-
tions for which a sub-Arctic floi'a — destined to become Alpine — was
specially organized, the difficulty of deriving such a flora from its par-
ent north, and of difFasing it over the snowy hills bounding this glacial
ocean, vanishes, and the presence of identical species at such distant
points remain no longer a mystery. Moreover, when we consider that
the greater part of the northern hemisphere was under such climatal
conditions during the epoch referred to, the undoubted evidences of
which have Iteen made known in Europe by numerous British and
Continental observers, on the bounds of Asia by Sir Roderick Murchi-
son, in America by Mr. Lyell, Mr. Logan, Captain Bayfield, and oth-
ers, and that the botanical (and zoological as well) region, essentially
northern and Alpine, designated by Professor Schouw that ' of saxi-
frages and mosses,' and first in his classification, exists now only on
the flanks of the great area which suflered such conditions ; and that,
though similar conditions reappear, the relationship of Alpine and Arctic
vegetation in the southern hemisphere, with that in the northern, is
entirely maintained by representative, and not by identical species (the
representative, too, being in great part generic, and not specific), the
general truth of my explanation of Alpine floras, including identical
species, becomes so strong, that the view proposed acquires fair claims
to be ranked as a theory, and not considered merely a convenient or
bold hypothesis "] — Tr.

350 COSMOS.

tlie north of Asia as far as the latitudes of Berhn and Ham-
burg, a fact of which Ehrenherg and myself have spoken in
other works*

The grov ping or association of different vegetable species,
to which we are accustomed to apply the term Floras, do not
appear to me, from what I have observed in different portions
of the earth's surface, to manifest such a predominance of in-
dividual families as to justify us in marking the geographical
distinctions between the regions of the Umbellatae, of the So-
lidaginsB, of the Labiatee, or the ScitaminesB. With reference
to this subject, my views differ from those of several of my
friends, who rank among the most distinguished of the bota-
nists of Germany. The character of the floras of the elevated
plateaux of Mexico, New Granada, and Quito, of European
Russia, and of Northern Asia, consists, in my opinion, not so
much in the relatively larger number of the species presented
by one or two natural families, as in the more complicated
relations of the coexistence of many families, and in the rela-
tive numerical value of their species. The Graminese and
the Cyperacese undoubtedly predominate in meadow lands
and steppes, as do ConifersB, Cupuliferee, and Betulineae in our
northern woods ; but this predominance of certain forms is
only apparent, and owing to the aspect imparted by the social
plants. The north of Europe, and that portion of Siberia
which is situated to the north of the Altai Mountains, have
no greater right to the appellation of a region of GraminesB
and Coniferse than have the boundless llanos between the
Orinoco and the mountain chain of Caraccas, or the pine for-
ests of Mexico. It is the coexistence of forms which may par-
tially replace each other, and their relative numbers and as-
sociation, which give rise Either to the general impression of
luxuriance and diversity, or of poverty and uniformity in the
contemplation of the vegetable world. *"

In this fragmentary sketch of the phenomena of organiza-
tion, I have ascended from the simplest cellt — the first mani-
festation of life — progressively to higher structures. " The

* Ehrenberg, iu the Annates des Sciences Naturelles, t. xxi., p. 387
412; Humboldt, Asie Centrale, t. i., p. 339-342, and t. iii., p. 96-101

+ Schleiden, TJeber die Entwichlungsioeise der Pflanzenzellen, in MUl
lers Archiv fur Anatomic nnd Physiologic, 1838, s. 137-176; also hia
Grundzuge der wissenschaftlichen Botanik, th. i., s. 191, and th. ii., s
ir. Schwann, Mikroscopiscke Untersuchungen uber die Ucbercinstim-
mung in der Struktur und dem Wachsthum der Thiere nnd PJlanzen,
1839, 8. 45, 220. Coinpai^ also, on similar propagation, Joh. Mu'ler
Physiologic des Mcnschen, 1840 th. ii.. a, 614.

MAN. 351

association of mucous granules constitutes a definitely-formed
cytoblast, around which a vesicular membrane forms a closed
cell," this cell being either produced from another pre-existing
cell * or being due to a cellular formation, which, as in the
case of the fermentation-fungus, is concealed in the obscurity
of some unknown chemical process.! But in a work Hke the
present we can venture on no more than an allusion to the
mysteries that involve the question of modes of origin ; the
geography of animal and vegetable organisms must limit itself
to the consideration of germs already developed, of their hab-
itation and transplantation, either by voluntary or involuntary
migrations, their numerical relation, and their distribution
over the surface of the earth.

The general picture of nature which I have endeavored to
delineate would be incomplete if I did not venture to trace a
few of the most marked features of the human race, considered
with reference to physical gradations — to the geographical
distribution of cotemporaneous types — to the influence exer-
cised upon man by the forces of nature, and the reciprocal,
although weaker action which he in his turn exercises on
these natural forces. Dependent, although in a lesser degree
than plants and animals, on the soil, and on the meteorolog-
ical processes of the atmosphere with which he is surrounded
— escaping more readily from the control of natural forces, by
activity of mind and the advance of intellectual cultivation,
no less than by his wonderful capacity of adapting himself to
all climates — man every where becomes most essentially asso-
ciated with terrestrial life. It is by these relations that the
obscure and much-contested problem of the possibility of one
common descent enters into the sphere embraced by a general
physical cosmography. The investigation of this problem will
impart a nobler, and, if I may so express myself, more purely
human interest to the closing pages of this section of my work.

The vast domain of language, in whose varied structure we
see mysteriously reflected the destinies of nations, is most inti-
mately associated with the affinity of races : and what even
slight differences of races may effect is strikingly manifested
in the history of the Hellenic nations in the zenith of their
intellectual cultivation. The most important questions of the
civihzation of mankind are connected with the ideas of races,

* Schleiden, Grundzuge der wissenschaftlichen Botanik, 1842, th. i.,
B. 192-197.

t [On cellular formation, see Henfrey's Outlines of Structural and
Physiological Botany, op. cit., p, 16-22.] — Tr.

352 COSMOS.

comm unity of language, and adherence to one original direo
tion of the intellectual and moral faculties.

As long as attention was directed solely to the extremes in
varieties of color and of form, and to the vividness of the first
impression of the senses, the observer was naturally disposed
to regard races rather as originally different species than as
mere varieties. The permanence of certain types* in the midst
of the most hostile influences, especially of climate, appeared
to favor such a view, notwithstanding the shortness of the in-
terval of time from which the historical evidence was derived.
In my opinion, however, more powerful reasons can be ad-
vanced in support of the theory of the unity of the human
race, as, for instance, in the many intermediate gradationsi
in the color of the skin and in the form of the skull, which
have been made known to us in recent times by the rapid prog-
ress of geographical knowledge — the analogies presented by
the varieties in the species of many wild and domesticated ani-
mals— -and the more correct observations collected regarding
the limits of fecundity in hybrids. J The greater number of
the contrasts which were formerly supposed to exist, have dis-
appeared before the laborious researches of Tiedemann on the
brain of negroes and of Europeans, and the anatomical inves-

* Tacitus, in his speculations on the inhabitants of Britain (Agricola,
cap. ii.), distinguishes with much judgment between that which may
be owing to the local climatic relations, and that which, in the immi-
grating races, may be owing to the unchangeable influence of a hered-
itary and transmitted type. " Britanuiam qui mortales initio coluerunt,
indigenae an advecti, ut inter barbaros, parum compertum. Habitua
corporis varii, atque ex eo argumenta ; namque rutilae Caledoniam hab-
itautium comae, magni artus Germanicam originem adseveraut. Silu
rum colorati vultus et torti plerumque crines, etposita contra Hispania,
Iberos veteres trajecisse, easque cedes occupasse fidem faciunt: proxi-
mi Gallis, et similes sunt : seu durante originis vi ; seu procurrentibus
in diversa terris, positio cceli corporibus habitum dedit." Regarding
the persistency of types of conformation in the hot and cold regions of
the earth, and in the mountainous districts of the New Continent, see
my Relation Historique, t. i., p. 498, 503, and t. ii., p. 572, 574.

t On the American races generally, see the magnificent work of
Samuel George Morton, entitled Crania Americana, 1839, p. 62, 86;
uud on the skulls brought by Pentland from the highlands of Titicaca,
see the Dublin Journal of Medical and Chemical Science, vol. v., 1834,
p. 475 ; also Alcide d'Orbigny, Vhomme Amiricain considers sous ses
rapports Physiol, et Mor., 1839, p. 221 ; and the work by Prince Maxi-
milian of Wied, which is well worthy of notice for the admirable ethno
graphical remarks in which it abounds, entitled Reise in das Innere von
Nordamerika (1839).

t Rudolph Wagner, Uebcr Blendlinge und-Ba$tarderzeug%ing, in his
notes to the German translation of Prichard's Physical History of Maw
kind, vol i., p. 138-150.

RACES. 353

tigations of Vrolik and Weber on the form of the pelvis. On
comparing the dark-colored African nations, on whose physical
history the admirable work of Prichard has thrown so much
light, with the races inhabiting the islands of the South-In
dian and West- Australian archipelago, and with the Papuas
and Alfourous (Haroforas, Endamenes), we see that a black
skin, woolly hair, and a negro-like cast of countenance are not
necessarily connected together.* So long as only a small por-
tion of the earth was known to the Western nations, partial
views necessarily predominated, and tropical heat and a black
skin consequently appeared inseparable. " The Ethiopians,"
said the ancient tragic poet Theodectes of Phaselis,t " are
colored by the near sun-god in his course with a sooty luster,
and their hair is dried and crisped with the heat of his rays."
The campaigns of Alexander, which gave rise to so many new
ideas regarding physical geography, likewise first excited a dis-
cussion on the problematical influence of climate on races.
" Families of animals and plants," writes one of the greatest
anatomists of the day, Johannes Miiller, in his noble and com-
prehensive work, Physiologic des Menschen, " undergo, within
certain limitations peculiar to the different races and species,
various modifications in their distribution over the surface of
the earth, propagating these variations as organic types of spe-
cies. J The present races of animals have been produced by

* Prichard, op. cit., vol. ii., p. 324.

t Onesicritus, in Strabo, xv., p. 690, 695, Casaub. Welcker, Grie-
chische Tragodien, abth. iii., s. 1078, conjectures that the verses of
Thei)dectes, cited by Strabo, are taken from a lost tragedy, which prob-
ably bore the title of " Memnon."

X [In illustration of this, the conclusions of Professor Edw^ard Forbes
respecting the origin and diffusion of the British flora may be cited.
See the Survey Memoir already quoted, On the Connection between the
Distribution of the existing Fauna and Flora of the British Islands, &c.,
p. 65. " 1. The flora and fauna, terrestrial and marine, of the British
islands and seas, have originated, so far as that area is concerned, since
the meiocene epoch. 2. The assemblages of animals and plants com-
posing that fauna and flora did not appear in the area they now^ inhabit
simultaneously, but at several distinct points in time. 3. Both the fauna
and flora of the British islands and seas are composed partly of species
which, either permanently or for a time, appeared in that area before
the glacial epoch ; partly of such as inhabited it during that epoch ; and
in great part of those which did not appear there until afterward, and
whose appearance on the earth was coeval with the elevation of the
bed of the glacial sea and the consequent climatal changes. 4. The
greater part of the terrestrial animals and flowering plants now inhab-
iting the British islands are members of specific centers beyond their
area, and have migrated to it over continuous laud before, during, or
after the glacial epoch. 5, The climatal conditions of the area under

364 COSMOS.

the combined action of many difierent mternal as well as ex-
ternal conditions, the nature of which can not in all cases be
defined, the most striking varieties being found in those fami-
lies which are capable of the greatest distribution over the sur-
face of the earth. The different races of mankind are forms
of one sole species, by the union of two of whose members
descendants are propagated. They are not different specie?
of a genus, since in that case their hybrid descendants would
remain unfruitful. But whether the human races have de-
scended from several primitive races of men, or from one alone,
is a question that can not be determined from experience."*

Geographical investigations regarding the ancient seat, the
so-called cradle of the human race, are not devoid of a myth-
discussion, and north, east, and west of it, were severer during the^la
cial epoch, when a great part of the space now occupied by the Pritish
isles was under water, than they are now or were before ; but there is
good reason to believe that, so far from those conditions having contin-
ued severe, or having gradually diminished in severity southward of
Britain, the cold region of the glacial epoch came directly into contact
with a region of more southern and thermal character than that in which
the most southern beds of glacial drift are now to be met with. 6. This
state of things did not materially differ from that now existing, under
corresponding latitudes, in the North American, Atlantic, and Arctic
seas, and on their bounding shores. 7. The Alpine floras of Europe
and Asia, so far as they are identical with the flora of the Arctic and
sub-Arctic zones of the Old World, are fragments of a flora which was
diffused from the north, either by means of transport not now in action
Dn the temperate coasts of Europe, or over continuous land which no
monger exists. The deep sea fauna is in like manner a fragment of the
general glacial fauna. 8. The floras of the islands of the Atlantic re-
gion, between the Gulf-weed Bank and the Old World, are fragments
of the great Mediterranean flora, anciently diffused over a land consti-
tuted out of the upheaved and never again submerged bed of the (shal-
low) Meiocene Sea. This great flora, in the epoch anterior to, and
probably, in part, during the glacial period, had a greater extension
northward than it now presents. 9. The termination of the glacial
epoch in Europe was marked by a recession of an Arctic fauna and flora
northward, and of a fauna and flora of the Mediterranean type south-
ward ; and in the interspace thus produced there appeared on land the
Germanic fauna and flora, and in the sea that fauna termed Celtic.
10. The causes which thus preceded the appearance of a new assem-
blage of organized beings were the destruction of many species of ani-
mals, and probably also of plants, either forms of extremely local dis-
tribution, or such as were not capable of enduring many changes of con-
ditions— species, in short, with very limited capacity for horizontal or
vertical diffusion. 11. All the changes before, during, and after the
glacial epoch appear to have been gradual, and not sudden, so that no
marked line of demarkation can be drawn between the creatures in-
habiting the same element and the same locality during two proximate
periods.''] — Tr.

* Joh. ^\M\f:r, Physiologie des Menschen, bd. ii., s. 768.

RACES. 355

ical character. " We do not know," says Wilhelm von Hum
boldt, in an unpublished work On the Varieties of Languages
and Nations, " either from history or from authentic tradition,
any period of time in which the human race has not been
divided into social groups. Whether the gregarious condition
was original, or of subsequent occurrence, we have no historic
evidence to show. The separate mythical relations found to
exist independently of one another in different parts of the
earth, appear to refute the first hypothesis, and concur in
ascribing the generation of the whole human race to the union
of one pair. The general prevalence of this myth has caused
it to be regarded as a traditionary record transmitted from
the primitive man to his descendants. But this very circum-
stance seems rather to prove that it has no historical founda-
tion, but has simply arisen from an identity in the mode of
intellectual conception, which has every where led man to
adopt the same conclusion regarding identical phenomena ; in
the same manner as many myths have doubtlessly arisen, not
from any historical connection existing between them, but
rather from an identity in human thought and imagination.
Another evidence in favor of the purely mythical nature of
this belief is afforded by the fact that the first origin of man-
kind— a phenomenon which is wholly beyond the sphere of
experience — is explained in perfect conformity with existing
views, being considered on the principle of the colonization of
some desert island or remote mountainous valley at a period
when mankind had already existed for thousands of years. It
is in vain that we direct our thoughts to the solution of the
great problem of the first origin, since man is too intimately
associated with his own race and with the relations of time
to conceive of the existence of an individual independently of
a preceding generation and age. A solution of those difficult
questions, which can not be determined by inductive reasoning
or by experience — whether the belief in this presumed tradi-
tional condition be actually based on historical evidence, or
whether mankind inhabited the earth in gregarious associa-
tions from the origin of the race — can not, therefore, be de-
termined from philological data, and yet its elucidation ought
not to be sought from other sources." fimcxoit LjLbiu*>

The distribution of mankind is therefore only a distribution
into varieties, which are commonly designated by the some-
what indefinite" term races. As in the vegetable kingdom,
and in the natural history of birds and fishes, a classification
into many small families is based on a surer foundation than

356 ('OSMOs.

where large sections are separated into a few but large divb
sions ; so it also appears to me, that in the determination of
races a preference should be given to the establishment of
small families of nations. Whether we adopt the old classi-
fication of my master, Blumenbach, and admit jive races (the
Caucasian, Mongolian, American, Ethiopian, and Malayan),
or that of Prichard, into seven races* (the Iranian, Turanian,
American, Hottentots and Bushmen, Negroes, Papuas, and
Alfourous), we fail to recognize any typical sharpness of def-
inition, or any general or well-established principle in the di-
vision of these groups. The extremes of form and color are
certainly separated, but without regard to the races, which
can not be included in any of these classes, and which have
been alternately termed Scythian and AUophyllic. Iranian is
certainly a less objectionable term for the European nations
than Caucasian ; but it may be maintained generally that
geographical denominations are very vague when used to ex-
press the points of departure of races, more especially where
the country which has given its name to the race, as, for in-
stance, Turan (Mawerannahr), has been inhabited at differ-
ent periodsf by Indo-Germanic and Finnish, and not by Mon-
golian tribes.

* Prichard, op. cit., vol. i., p. 247-

t The late arrival of the Turkish and Mongolian tribes on the Oxua
and on the Kirghis Steppes is opposed to the hypothesis of Niebuhr,
according to which the Scythians of Herodotus and Hippocrates were
Mongolians. It seems far more probable that the Scythians (Scoloti)
should be referred to the Indo-Germanic Massagets (Alani). The
Mongolian, true Tartars (the latter term was afterward falsely given to
purely Turkish tribes in Russia and Siberia), were settled, at that pe-
riod, far in the eastern part of Asia. See my Asie Centrale, t. i., p. 239
iOO ; Examen Critiqiie de VHistoire de la Giogr., th. ii., p. 320. A dis-
tinguished philologist, Professor Buschmann, calls attention to the cir-
cumstance that the poet Firdousi, in his half-mythical prefatoiy remarks
in \he Schahnameh,m.ent\ons "a fortress of the Alani" on the sea-shore,
in which Selm took refuge, this prince being the eldest son of the
King Feridun, who in all probability lived two hundred years before
Cyrus. The Kirghis of the Scythian steppe were originalJy a Finnish
tribe ; their three hordes probably constitute in the present day the
most numerous nomadic nation, and their tribe dwelt, in the sixteenth
century, in the same steppe in which I have myself seen them. The
Byzantine Menander (p. 380-382, ed. Nieb.) expressly states that the
Chacan of the Turks (Thu-Khiu), in 569, made a present of a Kirghis
slave to Zemarchus, the embassador of Justinian II. ; he terms her a
X^PXk ; and we find in Abulgasi {Historia Mongolorum el Tatarorum)
that the Kirghis are called Kirkiz. Similarity of manners, where the
nature of the country determines the principal characteristics, is a very
uncertain evidence of identity of race. The life of the steppes pro-
duces among the Turks (Ti Tukiu), the Baschkirs (Fins), the Kirghis,

LANGUAGE. 357

Larguages, as intellectual creations of man, and as closef y
interwoven with the development of mind, are, independently
of the Tiational form which they exhibit, of the greatest im-
portance in the recognition of similarities or differences in
races. This importance is especially owing to the clew which
a community of descent affords in treading that mysterious
'abyrinth in which the connection of physical powers and in-
tellectual forces manifests itself in a thousand different forms.
The brilliant progress made within the last half century, in
Germany, in philosophical philology, has greatly facilitated
our investigations into the nationcU character* of languages
and the influence exercised by descent. But here, as in all
domains of ideal speculation, the dangers of deception are
closely linked to the rich and certain profit to be derived.

Positive ethnographical studies, based on a thorough knowl-
edge of history, teach us that much caution should be applied
in entering into these comparisons of nations, and of the lan-
guages employed by them at certain epochs. Subjection,
long association, the influence of a foreign religion, the blend-
ing of races, even when only including a small number of the
more influential and cultivated of the immigrating tribes,
have produced, in both continents, similarly recurring phenom-
ena ; as, for instance, in introducing totally different families
of languages among one and the same race, and idioms, having
one common root, among nations of the most different origin.
Great Asiatic conquerors have exercised the most powerful
influence on phenomena of this kind.

But language is a part and parcel of the history of the de-
velopment of mind ; and, however happily the human intel-
lect, under the most dissimilar physical conditions, may unfet-
tered pursue a self-chosen track, and strive to free itself from
the dominion of terrestrial influences, this emancipation is
never perfect. There ever remains, in the natural capacities
of the mind, a trace of something that has been derived from
the influences of race or of climate, whether they be associated
with a land gladdened by cloudless azure skies, or with the
vapory atmosphere of an insular region. As, therefore, rich-
ness and grace of language are unfolded from the most luxu-

the Torgodi and Dsungari (Mongolians), the same habits of nomadic
life, and the same use of felt tents, carried on wagons and pitched
among herds of cattle.

* Wilhelm von Humboldt, Ueber die Versckiedenheit der menschUchen
Spr<ichbaues, in his great work Ueber die Kawi'Sprache auf der Insfil
Jama, bd. i., s. xxi., xlviii., and ccxiv.

35H COSMOS.

riant depths of thought, we have been unwilling wholly to
disregard the bond which so closely links together the physical
world with the sphere of intellect and of the feelings by de-
priving this general picture of nature of those brighter lights
and tints which may be borrowed from considerations, however
slightly indicated, of the relations existing between races and
languages.

While we maintain the unity of the human species, we at
the same time repel the depressing assumption of superior
and inferior races of men.^ There are nations more sus-
ceptible of cultivation, more highly civilized, more ennobled
by mental cultivation than others, but none in themselves no-
bler than others. All are in like degree designed for freedom ;
a freedom which, in the ruder conditions of society, belongs
only to the individual, but which, in social states enjoying po-
litical institutions, appertains as a right to the whole body
of the community. " If we would indicate an idea which,
throughout the whole course of history, has ever more and
more widely extended its empire, or which, more than any
other, testifies to the much-contested and still more decidedly
misunderstood perfectibility of the whole human race, it is
that of establishing our common humanity — of striving to re-
move the barriers which prejudice and limited views of every
kind have erected among men, and to treat all mankind, with-
out reference to religion, nation, or color, as one fraternity, one
great community, fitted for the attainment of one object, the
unrestrained development of the physical powers.' This is the
ultimate and highest aim of society, identical with the direc-
tion implanted by nature in the mind of man toward the in-
definite extension of his existence. He regards the earth in
all its limits, and the heavens as far as his eye can scan their
bright and starry depths, as inwardly his own, given to him
as the objects of his contemplation, and as a field for the de-
velopment of his energies. Even the child longs to pass the
hills or the seas which inclose his narrow home ; yet, when
his eager steps have borne him beyond those limits, he pines,
like the plant, for his native soil ; and it is by this touching
and beautiful attribute of man — this longing for that which
is unknown, and this fond remembrance of that which is lost
— that he is spared from an exclusive attachment to the pres-

* The very cheerless, and, iu recent times, too often discussed doc-
trine of the unequal rights of men to freedom, and of slaver)'- as an in«
gtitution ill conformity with nature, is unhappily found most systematio-
ally developed in Aristotle's Politica, i., 3, 5, 6.

CONCLUSION OF THE SUBJECT. 3?

ent. Thus deeply rooted in the innermost nature of man, ana
even enjoined upon him by his highest tendencies, the recog-
nition of the bond of humanity becomes one of the noblest
leading principles in the history of mankind. "*=

With these words, which draw their charm from the depths
of feeling, let a brother be permitted to close this general de-
scription of the natural phenomena of the universe. From the
remotest nebulae and from the revolving double stars, we have
descended to the minutest organisms of animal creation, wheth-
er manifested in the depths of ocean or on the surface of our
globe, and to the delicate vegetable germs which clothe, the
naked declivity of the ice-crowned mountain summit ; and
here we have been able to arrange these phenomena accord-
ing to partially known laws ; but other laws of a more mys-
terious nature rule the higher spheres of the organic world, in
which is comprised the human species in all its varied con-
formation, its creative intellectual power, and the languages
to which it has given existence. A physical delineation of
nature terminates at the point where the sphere of intellect
begins, and a new world of mind is opened to our view. It
marks the limit, but does not pass it.

* Wilhelm von Humboldt, Ueber die Kawi-Sprache, bd. iii., s. 426.
I subjoin the following extract from this work: " The impetuous con-
quests of Alexander, the more politic and premeditated extension of
territory made by the Romans, the wild and cruel incursions of the
Mexicans, and the despotic acquisitions of the iucas, have in both hemi
Bpheres contributed to put an end to the separate existence of many
tribes as independent nations, and tended at the same time to establish
more extended international amalgamation. Men of great and strong
minds, as well as whole nations, acted under the influence of one idea,
the purity of which was, however, utterly unknown to them. It was
Christianity which first promulgated the truth of its exalted charity,
although the seed sown yielded but a slow and scanty harvest. Before
the religion of Christ manifested its form, its existence was only re-
vealed by a faint foreshadowing presentiment. In recent times, the
idea of civilization has acquired additional intensity, and has given rise
to a desire of extending more widely the relations of national inter-
course and of intellectual cultivation ; even selfishness begins to learn
that by such a course its interests will be better served than by violent
and forced isolation. Language, more than any other attribute of man-
kind, binds together the whole human race. By its idiomatic proper
ties it certainly seems to separate nations, but the I'eciprocal under-
•tanding of foreign languages connects men together, ct the othei hand
without injuring individual national characteristics."

ADDITIONAL NOTES

TO THE PRESENT EDITION. MARCH, 1849.

Gigantic Birds of New Zealand. — Vol. i., p. 287.
An extensive and highly interesting collection of bones, referrible to
several species of the iV/oa (Dinornis of Owen), and to three or four other

fjenera of birds, formed by Mr. Walter Mantell, of Wellington, New Zea-
and, has recently arrived in England, and is now deposited in the Brit-
ish Museum. This series consists of between 700 and 800 specimens,
belonging to different parts of the skeletons of many individuals of
various sizes and ages. Some of the largest vertebrae, tibiae, and fem-
ora equal in magnitude the most gigantic previously known, while oth-
ers are not larger than the con-esponding bones of the living apteryx.
Among these relics are the skulls and mandibles of two genera, the Di-
nornis and Palapieryx ; and of an extinct genus, Notornis, allied to the
RallidcB ; and the mandibles of a species of Nestor, a genus of nocturn
al owl-like parrots, of which only two living species are known.*

These osseous remains are in a very different state of preservation
from any previously received from New Zealand ; they are light and
porous, and of a light fawn-color; the most delicate processes are en
tire, and the articulating surfaces smooth and uninjured; fragments of
egg-shells, and even the bony rings of the trachea and air tubes, are pre'
served.

The bones were dug up by Mr. Walter Mantell from a bed of marly
Band, containing magnetic iron, crystals of hornblende and augite, and
the detritus of augitic rocks and earthy volcanic tuff. This sand had
filled up all the cavities and cancelli, but was in no instance consoli-
dated or aggregated together ; it was, therefore, easily removed by a
soft brush, and the bones perfectly cleared without injury.

The spot whence these precious relics of the colossal birds that once
inhabited the islands of New Zealand were obtained, is a flat tract of
land, near the embouchure of a river, named Waingongoro, not far from
Wanganui, whioli has its rise in the volcanic regions of Mount Egmont.
The natives affirm that this level tract was one of the places first dwelt
upon by their remote ancestors ; and this tradition is corroborated by
the existence of numerous heaps and pits of ashes and charred bones
mdicating ancient fires, long burning on the same spot. In these fire-
heaps Mr. Mantell found burned bones of men, moas, and dogs.

The fragments of egg-shells, imbedded in the ossiferous deposits, had
escaped the notice of all previous naturalists. They are, unfortunately,
very small portions, the largest being only four inches long, but they
afford a chord by which to estimate the size of the original. Mr. Man-
tell observes that the e^^ of the Moa must have been so large that a
hat would form a good egg-cup for it. These relics evidently belong
to two or more species, perhaps genera. In some examples the ex

* See Professor Owon's Memoir on these fossil remains, in Zoological Tra'%tai»
iions, 1848 '

Vol. 1— Q

362 ADDITIONAL NOTES.

ternal surface is smooth ; in others it is marked with short intercepted
linear grooves, resembhng the eggs of some of the Struthionidee, but
distinct from all known recent types. In this valuable collection only
one bone of a mammal has been detected, namely, the femur of a dog.
An interesting memoir on the probable geological position and age
of the ornithic bone deposits of New Zealand, by Dr. Mantell, based
on the observations of his enterprising son, is published in the Quarter
ly Journal of the Geological Society of London (1848). It appears that
in many instances the bones are imbedded in sand and clay, which I^e
beneath a thick deposit of volcanic detritus, and rest on an argillaceaes
stratum abounding in marine shells. The specimens found in the rivers
and streams have been washed out of their banks by the currents which
now flow through channels from ten to thirty feet deep, formed in the
more ancient alluvial soil. Dr. Mantell concludes that the islands of
New Zealand were densely peopled at a period geologically recent,
though historically remote, by tribes of gigantic brevi-pennate birds
allied to the ostrich tribe, all, or almost all, of species and genera now
extinct ; and that, subsequently to the formation of the most ancient
ornithic deposit, the sea-coast has been elevated from fifty to one hund-
red feet above its original level ; hence the terraces of shingle and
loam which now skirt the maritime districts. The existing rivers and
mountain torrents flow in deep gulleys which they have eroded in the
course of centuries in these pleistocene strata, in like manner as the
river courses of Auvergne, in Central France, are iexcavated in the
mammiferous tertiary deposits of that country. The last of the gigantic
birds were probably exterminated, like the dodo, by human agency :
some small species allied to the apteryx may possibly be met with in
the unexplored parts of the middle island.

The Dodo. — A most valuable and highly interesting history of the
dodo and its kindred-* has recently appeared, in which the history,
affinities, and osteology of the Dodo, Solitaire, and other extinct birds
of the islands Mauritius, Rodriguez, and Bourbon are admirably eluci-
dated by H. G. Strickland (of Oxford), and Dr. G. A. Melville. The
historical part is by the former, the osteological and physiological por-
tion by the latter eminent anatomist. We would earnestly recommend
the reader interested in the most perfect history that has ever appear-
ed, of the extinction of a race of large animals, of which thousands ex-
isted but three centuries ago, to refer to the original work. We have
only space enough to state that the authors have proved, upon the most
incontrovertible evidence, that the dodo was neither a*vulture, ostrich,
nor galline, as previous anatomists supposed, but a frugiverous pigc^H

* The Dodo and its Kindred. By MesBre. Strickland and Melville. 1 voL 4ti^
with numerous plates. Reeves, London, 1846.

INDEX TO VOL. I.

ABICH, Hermann, etructural relations of
volcanic rocks, 234.

Acosta, Joseph de, Historia Natural de las
Indias, 66, 193.

Adams, Mr., planet Neptune. See note
by Translator, 90, 91.

iEgos Potamos, on the aerolite of, 117,
122.

filian on Mount ^tna, 227.

Aerolites (shooting stars, meteors, mete-
oric stones, fire-balls, &c.), general de-
scription of, 111-137 ; physical charac-
ter, 112-123; dates of remarkable falls,
114, 115 ; their planetary velocity, 116-
120; ideas of the ancients on, 115, 116;
November and August periodic falls of
shooting stars, 118-120, 124-126; their
direction from one point in the heav-
ens, 120 ; altitude, 120; orbit, 127; Chi-
nese notices of, 128 ; media of commu-
nication with other planetary bodies,
136 ; their essential ditlerence from
comets, 137 ; specific weights, 116, 117 ;
large meteoric stones on record, 117 ;
chemical elements, 117, 129-131 ; crust,
129, 130; deaths occasioned by, 135.

ffischylus, " Prometheus Delivered," 115.

-Etna, Mount, its elevation, 28, 229 ; sup-
■^josed extinction by the ancients, 227 ;
its eruptions from lateral fissures, 229 ;
similarity of its zones of vegetation to
those of Ararat, 347.

Agassiz, Researches on Fossil Fishes, 46,
27.3-277.

Alexander, influence of his campaigns on
physical science, 353.

Alps, the, elevation of, 28, 29.

Amber, researches on its vegetable origin,
284 ; Goppert on the amber-tree of the
ancient world (Pinites succifer), 283.

Ampere, Andr6 Marie, 58, 193, 236.

Anaxagoras on aerolites, 122 ; on the sur-
rounding ether, 134.

Andes, the, their altitude, &c. See Cor-
dilleras.

Anghiera, Peter Martyr de, remarked that
the palmeta and pineta were found as-
sociated together, 282, 283 ; first recog-
nized (1510) that the limit of perpetual
snow continues to ascend as we ap-
proach the equator, 329.

Animal life, its universality, 342-345; as
viewed with microscopic powers of vis-
ion, 341-346; rapid propagation and te-
nacity of life in animalcules, 344-346 ;
geography of, 341-346.

Anning, Miss Mary, discovery of the ink
bag of the sepia, and of coprolites of

fish, in the liaa of Lyme Regis, «7l,

272.
Ansted's, D. T., "Ancient World." Set
notes by Translator, affl, 272, 274, 281
287.
Apian, Peter, on comets, 101.

Apollonius Myndius, described the paths
of comets, 103.

Arago, his ocular micrometer, 39 ; chro-
matic polarization, 52 ; optical consid-
erations, 85; on comets, 99-106; polar-
ization experiments on the light of com-
ets, 105; aerolites, 114; on the Novem
ber fall of meteors, 124 ; zodiacal light.
143; motion of the solar system, 146,
147 ; on the increase of heat at increas-
ing depths, 173, 174 ; magnetism of ro
taiion, 179, 180 , horary observations of
declination at Paris compared with si-
multaneous perturbations -«t Kasan,
191 ; discovery of the influence of mag-
netic storms on the course of the nee-
dle, 194, 195 ; on south polar bands, 198;
on terrestrial light, 202 ; phenomenon
of supplementaiy rainbows, 220; ob-
served the deepest Artesian wells to be
the warmest, 223 ; explanation of the
absence of a refrigeration of tempera-
ture in the lower strata of the Mediter-
ranean, 303 ; observations on the mean
annual quantity of rain in Paris, 333 ;
his investigations on the evolution of
lightning, 337.

Argelander on the comet of 1811, 109 ; on
the motion of the solar system, 146, 149 ; ,
on the light of the Aurora, 195, 196.

Aristarchus of Samos, the pioneer of the
Copernican system, 65.

Aristotle, 65 ; his definition of Cosmos, 69 ;
use of the term history, 75 ; on comets,
103, 104 ; on the Ligyan field of stones,
115 ; aerolites, 122 ; on the stone of jEgoa
Potamos, 135 ; aware that noises some
times existed without earthquakes, 209 ,
his account of the upheavals of islands
of eruption, 241 ; " spontaneous mo-
tion," 341 ; noticed the redness assum-
ed by long- fallen snow, 344.

Artesian wells, temperature of, 174, 223.

Astronomy, results of, 38-40 ; phenonienj
of physical astronomy, 43, 44.

Atmosphere, the, general description of,
311, 316 ; its composition and admix-
ture, 312; variation of pressure, 313-
317 ; climatic distribution of heat, 313,
317-323 ; distribut on of humidity, 313,
328, 3'i4; electric condition, 314, 335-
3.38.

86ii

COSMOS

August, his pdychrometer, 332.

Augustine, St., his views on spontaneous
generation, 345, 346.

Aurora Borealis. general description of,
193-202; origin and course, 195, 196;
altitude, 199 ; brilliancy coincident with
the fall of shooting stars, 126, 127;
whether attended with crackling sound,
199 200; intensity of its light, 201.

Bacon, Lord, 53, 58 ; Novum Organon,
290.

Baer, Von, 337.

Bai-ometer, the, increase of its height, at-
tended by a depression of the level of
the sea, 298 ; hftrary oscillations of, 314,
315.

Batten, Mr., letter, on the snow-line of the
two sides of the Himalaya^, 331, 332.

Beaufort, Capt., observed the emissions
of inflammable gas, on the Caramanian
coast, as described by Pliny, 223. See,
also, note by Translator, 223.

Beaumont, Elie de, on the uplifting of
mountain chains, 51, 300 ; influence of
the rocks of melaphyre and serpentine,
in the southern declivities of the Alps,
on pendulum experiments, 167; con-
jectures on the quartz strata of the Col
de la Poissoni^re, 266.

Leccaria, observation of steady luminous
appearance in the clouds, 202 ; of ligbt-
ning clouds, unaccompanied by thun-
der or indications of storm, 337.

Beechey, Capt., 97 ; observations on the
temperature and density of the water
of the ocean under dift'erent zones of
longitude and latitude, 306.

Bembo, Cardinal, his observations on the
eruptions of Mount iEtna, 229 ; theory
of the necessity of the proximity of vol-
canoes to the sea, 243 ; vegetation on
the declivity of ^tna, 347.

B§rard, Capt, shooting stars, 119.

Bertou, Count, his barometrical measure-
ments of the Dead Sea, 296.
^Berzelius on the chemical elements of
aerolites, 130, 131.

Benzenberg on meteors and shooting
stars, 119, 120 ; their periodic return in
August, 125.

Bessel's theory on the oscillations of the
pendulum, 44 ; pendulum experiments,
64 ; on the parallax of 61 Cygni, 88 ; on
Halley's comet, 102, 103, 104 ; on the as-
cent of shooting stars, 123 ; on their par-
tial visibiUty, 128 ; velocity of the sun's
translstory motion, 145 ; mass of the
star 61 Cygni, 148 ; parallaxes and dis-
tances of fixed stars, 153; comparison
of measurements of degrees, 165, 166.

Plot on the phenomenon of twilight, 118 ;
on the zodiacal light, 141 ; pendulum
experiments at Bordeaux, 170.

Biot, Edward, Chinese observations of

comets, 101, 109 ; of aerolites, 128.
Bischof on the interior heat of the globe,

^J, 219, 235, 244, 294.
61umenbach, his classi^cation of the races
of men, 356.

Bockh, origin dKiie atcient myth of tb*
Nemean lunar lion, 134, 135.

Boguslawski, falls of shooting stars, 119
128.

Bonpland, M., and Humboldt, on the po-
lagic shells found on the ridge of the
Andes, 45.

Bopp, derivation of the word Cosmos,
70.

Boussingault, on the depth at which is
found the mean annual temperrture
within the tropics, 175; on the volca-
noes of New Granada, 217 ; on the tem-
perature of the earth in the tropics, 220
221 ; temperature of the thermal springs
of Las Trincheras, 222; his investiga-
tions on the chemical analysis of the at-
mosphere, 311, 312 ; on the mean an-
nual quantity of rain in dift'erent parts
of South America, 333, 334.

Bouvard, M., 105 ; his observations on that
portion of the horary oscillations of tho
pressure of the atmosphere, which de
pends on the attraction of the moon
313.

Bramidos y truenos of Guanaxuato, 209,
210.

Brandes, tails of shooting stars, 114, 1 16
height and velocity ot shooting stars,
120 ; their periodic falls, 125, 126.

Bravais, on the Aurora, 201 ; on the daily
oscillations of the barometer in 70''
north latitude, 314 ; distribution of the
quantity of rain in Central Europe, 334 ;
doubts on the greater dryness of mount-
ain air, 334.

Brewster, Sir David, first detected the
connection between the curvature of
magnetic lines and my isothermal lines
193.

Brongniart, Adolphe, luxuriance of the
primitive vegetable world, 218 ; fossil
flora contained in coal measures, 280.

Brongniart, Alexander, formation of rib-
bon jasper, 259 ; one of the founders of
the archaeology of organic life, 273.

Brown, Robert, flrst discoverer ( )f molec-
ular motion, 341.

Bach's, Leopold von, theory on the eleva-
tion of continents and mountain chains,
45; on the craters and circular form
of the island of Palma, 226 ; on volca-
noes, 234, 238, 242, 243, 247 ; on meta-
morphic rocks, 249-252, 260, 263, 264 ;
on the origin of various conglomerates
and rocks of detritus. 269 ; classification
of ammonites, 276, 277; physical causes
of the elevation of continents, 295 ; on
the changes in height of the Swedish

Buckland, 272 ; on the fossil flora of the
coal measures, 279.

Buffbn, his views on the geographical dis-
tribution of animals, 348.

Burckhardt, on the volcano of Medina,
246 ; on the hornitos de JoruUo, see
note by Translator, 230.

Burnes, Sir Alexander, on the purity of
the atmosphere in Bokhara, 114<( prop-
agation of shof'ks of earthquakes, 21?

INDEX.

305

Caille, La, pendulum measurements at
the Cape of Good Hope, 169.

Caldas, quantity of rain at Santa F6 de
Bogota, 334.

Caraargo's MS. Historia de Tlascala, 140.

Capocci, his observations on periodic falls
of aerolites, 126.

Carlini, geodesic experiments in Lombar-
dy, 168 ; Mount Cenis, 170.

Carrara marble, 262, 263.

Carus, his definition of "Nature," 41.

Caspian Sea, its periodic rise and fall, 297.

Cassini, Dominicus, on the zodiacal light,
139, 140; hypothesis on, 141; his dis-
covery of the spheroidal form of Jupi-
ter, 164.

Cautley, Capt., and Dr. Falconer, discov-
ery of gigantic fossils in the Himalayas,
278. See, also, note by Translator, 278.

Cavanilles, first entertained the idea of
seeing grass grow, 149.

Cavendish, use of the torsion balance to
determine the mean density of the
Earth, 170.

Challis, Professor, on the Aurora, March
19 and Oct. 24th, 1847, see note by
Translator, 195, 199.

Chardin, noticed in Persia the famous
comet of 1668, called " nyzek." or " pe-
tite lance," 139.

Charpentier, M., belemnites found in the
primitive limestone of the Col de la
Seigne, 261 ; glaciers, 329.

Chemistry as distinguished from physics,
62 ; chemical affinity, 63.

Chevandier, calculations on the carbon
contained in the trees of the forests of
our temperate zones, 281.

Childrey first described the zodiacal light
in his Britannia Baconica, 138.

Chinese accounts of comets, 99, 100, 101 ;
shooting stars, 128 ; "fire springs." 158 ;
knowledge of the magnetic needle, 180;
electro-magnetism, 188, 189.

Chladni on meteoric stones, &c., 118,
135 ; on the selenic origin of aerolites,
121 ; on the supposed phenomenon of
ascending shooting stars, 122 ; on the ob-
scuration of the Sun's disk, 133 ; sound-
figures, 135; pulsations in the tails of
comets, 143,

Choiseul. his chart of Lemnos, 246.

Chromatic polarization. See Polarization.

Cirro-cumulus cloud. See Clouds.

Cirrous strata. See Clouds.

Clark, his experiments on the variations
of atmospheric electricity, 335, 336.

Clarke, J. G., of Maine, U. S., on the comet
of 1843, 100.

Climatic distribution of heat, 313, 317-
328 ; of humidity, 328, 333, 334.

Climatology, 317-329 ; climate, general
sense ot! 317, 318.

Clouds, their electric tension, color, and
height, 336, 337; connection of cirrous
strata with the Aurora Borealis, 196 ;
cirro-cumulus cloud, phenomena of,
197 ; luminous, 202 ; Dove on their for-
mation and appearance, 315, 316 ; often
uresent on a bright summer sky the

"projected image" of the soil below,
316 ; volcanic, 233.

Coal formations, ancient vegetable re
mains in, 280, 281.

Coal mines, depths of, 158-160.

Cclebrooke on the snow-line of the two
sides of the Himalayas, 31.

Colladon, electro-magnetic apparatus, 335.

Columbus, his remark that "the Earth is
small and narrow," 164 ; found the com-
pass showed no variation in the Azores,
181, 182 ; of lava streams, 245 ; noticed
coniferae and palms growing together in
Cuba, 282 ; remarks in his journal on
the equatorial currents, 307 ; of the Sar-
gasso Sea, 308 ; his dream, 310, 311.

Comets, general description of, 99-112;
Biela's, 43, 86, 107, 108 ; Blaupain's, 108 ;
Clausen's, 108 ; Encke's, 43, 64, 86, 106-
108 ; Faye's, 107, 108 ; Halley's, 43, 100,
102-109 ; Lexell's and Burckhardt's,
108, 110 ; Messier's, 108 ; Olbers's, 109 ;
Pons's. 109 ; famous one of 1668, seen
in Peisia, called "nyzek," or "petite
lance," 189 ; comet of 1843, 101 ; their
nucleus and tail, 87, 100; small mass,
100 ; diversity of form, 100-103 ; light,
104-106 ; velocity, 109 ; comets of short
period, 107-109 ; long period, 109, 110 ;
number, 99 ; Chinese observations on,
99-101 ; value of a knowledge of their
orbits, 43 ; possibility of collision of Bi-
ela's and Encke's comets, 107, 108 ; hy-
pothesis of a resisting medium conjec-
tured from the diminishing period of
the revolution of Encke's comet, 106 ;
apprehensions of their collision with
the Earth, 108, 110, 111 ; their popular
supposed influence on the vintage. 111.

Compass, early use of by the Chinese,
180 ; permanency in the West Indies,
181.

Condamine, La, inscription on a marble
tablet at the Jesuit's College, Quito, on
the use of the pendulum as a measure
of seconds, 166, 167.

Condi, notice of a heavy shower of shoot-
ing stars, Oct., 902, 119.

Coraboeuf and Delcrois, geodetic opera-
tions, 304.

Cordilleras, scenery of, 26, 29, 33 ; vege-
tation, 34, 35 ; intensity of the zodiacal
light, 137.

Cosmography, physical, its object and ul-
timate aims, 57-60 ; materials, 60.

Cosmos, the author's object, 38, 78 ; prim-
itive signification and precise definition
of the word, 69 ; how employed by
Greek and Roman writers, 69, 60 ; der-
ivation, 70.

Craters. See Volcanoes.

Curtius, Professor, his notes on the tem-
perature of various springs in Greece,
222, 223.

C'uvier, one of the founders of the archae
ology of organic life, 273 ; discovery ol
fossil crocodiles in the tertiary forma
tion, 274.

DaiPiachos on the phenomena attending

366

COSMOS.

the fall of the stone of ^gos Potamos,
133, 134.

Dalman on the existence of Chionsea ara-
neoides in polar snow, 344.

Dalton, observed the southern lights in
England, 198.

Dante, quotation from, 322.

Darwin, Charles, fossil vegetation in the
travertine of Van Diemen's Land, 224 ;
central volcanoes regarded as volcanic
chains of small extent on parallel fis-
sures, 238; instructive materials in the
temperate zones of the southern hem-
isphere for the study of the present and
past geography of plants, 282, 283 ; on
the fiordformation at the southeast end
of America, 293 ; on the elevation and
depression of the bottom of the South
Sea, 297 ; rich luxuriance of animal life
m the ocean, 309, 310 ; on the volcano
of Aconcagua, 330.

Daubeney on volcanoes. See Transla-
tor's notes, 161, 203, 204, 210, 218, 224,
228, 230, 233, 234, 235, 236, 244, 245.

Daussy, his barometric experiments, 298 ;
observations on the velocity of the equa-
torial current, 307.

Davy, Sir Humphrey, hypothesis on act-
ive volcanic phenomena, 235; on the
low temperature of water on shoals, 309.

Dead Sea. its depression below the level
of the Mediterranean, 296, 297.

Dechen, Von, on the depth of the coal-
basin of Liege, 160.

Delcrois. See Coraboeuf.

Descartes, his fragments of a contempla-
ted work, entitled " Monde," 68 ; on
comets, 139.

Deshayes and Lyell, their investigations
on the numerical relations of extinct
and existing organic life, 275.

Dicajarchus, his "parallel of the dia-
phram," 289.

Diogenes Laertius, on the aerolite of
Mgos Potamos, 116, 122, 134.

D'Orbigny, fossil remains from the Hima-
laya and the Indian plains of Cutch, 277.

Dove on the similar action of the dechna-
tion needle to the atmospheric electrom-
eter, 194; "law of rotation," 315; on the
formation and appearance of clouds,
316 ; on the diti'erence between the
true temperature of the surface of the
ground and the indications of a ther-
mometer suspended in the shade, 325 ;
hygrometric windrose, 333.

Doyere, his beautiful experiments on the
tenacity of life in animalcules, 345.

Drake, shaking of the earth for successive
days in the United States (1811-12), 211.

Dufr^noy et Elie de Beaumont, Geologie
de la France, 253, 258, 259, 260, 262, 266.

Dumas, results of his chemical analysis
of the atmosphere, 311.

Dunlop on the comet of 1825, 103.

Duperrey on the configuration of the mag-
netic equator, 183; pendulum oscilla-
tions, 166.

Duprez, influence of trees on the intensi-
ty of electricity in the atmosphere, 335.

Eandi, Vassalli, electric perturbation dur
ing the protracted earthquake of Pigiie-
rol, 206.

Earth, survey of its crust, 72; relative
magnitude, &c., in the solar system,
95-97 ; general description of terrestri-
al phenomena, 154-369; geographical
distribution, 161, 162; its mean density,
169-172; internal heat and temperature.
172-176 ; electro-magnetic activity, 177
193 ; conjectures on its early high' tem
perature, 172 ; interior increase of heat
with increasing depth, 161 ; greatest
depths reached by human labor, 157-
159 ; methods employed to investigate
the curvature of its surface, 165-168 ;
reaction of the interior on the external
crust, 161, 202-247 ; general delineation
of its reaction, 204-206 ; fantastic views
on its interior, 171.

Earthquakes, general account of, 204-218 ,
their manifestations, 204-206 ; of Rio-
bamba, 204, 206, 208, 213, 214 ; Lisbon,
210. 211, 213, 214 ; Calabria, 206 ; their
propagation, 204, 212, 213; waves ot
commotion, 205, 206, 212 ; action on
gaseous and aqueous springs, 210, 222,
224 , salses and mud volcanoes, 224-
228 ; erroneous popular belief on, 206-
208 ; noise accompanying earthquakes,
208-210 ; their vast destruction of life,
210, 211 ; volcanic force, 214, 215 ; deep
and peculiar impression produced on
men and animals, 215, 216.

Ehrenberg, his discovery of infusoria in
the polishing slato of Bilin, 150 ; infuso-
' fi;il deposits, 255, 262 ; brilliant discov-
ery of microscopic life in the ocean and
in the ice of the polar regions, 342 ; rap-
id propagation of animalcules and their
tenacity of life, 343-345; transforma-
tion of chalk, 262.

Electricity, magnetic, 188-202 ; conjec-
tured electric currents, 189, 190 ; elec-
tric storms, 194 ; atmospheric, 335
337. '"

Elevations, comparative, of mountains in
the two hemispheres, 28, 29.

Encke, 106 ; his computation that the
showers of meteors, in 1833, proceeded
from the same point of space in the di-
rection in which the Earth was moving
at the time, 119, 120.

Ennius, 71.

Epicharmus, writings of, 71.

Equator, advantages of the countries boi
dering on, 33, 34 ; their organic richness
and fertility, 34, 35 ; magnetic equator,
183-185.

Erman, Adolph, on the three cold days
of May (llth-13th), 133 ; hues of decli-
nation in Northern Asia, 182; in the
southern parts of the Atlantic, 187 ,
observations during the earthquake at
Irkutsk, on the non-disturbance of the
horary changes of the magnetic needle,
207.

Eruptions and exhalations (volcanic), la-
va, gaseous and liquid fluids, hot mud,
mud mofettes, &c., 161, 210-'*'70

INDEX.

367

Ethnographical studies, their importance

and teaching, 357, 358.
Euripides, his Phaeton, 122.

Falconer, Dr., fossil researches in the
Himalayas, 278.

Faraday, radiating heat, electro-magnet-
ism, &c., 49, 179, 188 ; brilliant discov-
ery of the evolution of light by mag-
netic forces, 193.

Farquharson on the connection of cirrous
clouds with the Aurora, 197 ; its alti-
tude, 199.

Fedorow, his pendulum experiments, 168.

Feldt on the ascent of shooting stars, 123,

Ferdinandea, igneous island of, 242.

Floras, geographical distribution of, 350.

Forbes, Professor E., inference to his
Travels in Lycia, 223 ; account of the
island of Santorino, 241, 242.

Forbes, Professor J., his improved seis-
mometer, 205 ; on the correspondence
existing between the distribution of ex-
isting floras in the British Islands, 348,
349 ; on the origin and ditfusion of the
British flora, 353, 354.

Forster, George, remarked the climatic
difi'erence of temperature of the east-
ern and western coasts of both conti-
nents, 321.

Forster, Dr. Thomas, monkish notice of
*' Meteorodes," 123.

Fossil remains of tropical plants and an-
imals found in northern regions, 46,
270-284; of extinct vegetation in the
travertine of Van Diemen's Land, 224 ;
fossil human remains, 250.

Foster, Reinhold, pyramidal configura-
tion of the southern extremities of con-
tinents, 290, 291.

Fourier, temperature of our planetary
system, 155, 172, 176.

Fracastoro on the direction of the tails of
comets from the sun, 101.

Fraehn, fall of stars, 119.

Franklin, Benjamin, existence of sand-
banks indicated by the coldness of the
water over them, 308.

Franklin, Capt, on the Aurora, 197, 199,
200, 201 ; rarity of electric explosions
in high northern regions, 337.

Freycinet, pendulum oscillations, 166.

Fusinieri on meteoric masses, 123.

Galileo, 104. 167.

Galle, Dr., 91.

Galvani, Aloysio, accidental discovery of
galvanism, 52.

Gaseous emanations, fluids, mud, and
molten earth, 217-220.

Gasparin. distribution of the quantity of
rain in Central Europe, 333.

Gauss, Friedrich, on terrestrial magnet-
ism, 179 ; his erection, in 1832, of a mag-
netic observatory on a new principle,
191, 192.

Qav-Lussac, 204, 233, 234, 266, 267, 311,
312, 334, 330.

Geognostic or geological description of
the earth's surface, 202-286.

Geognosy (the study of the textures and
position of the earth's surface), its prog-
ress, 203.

Geography, physical, 288-311 ; of animaJ
life, 341-346 ; of plants, 346-351.

Geographies, Hitter's (Carl), "Geography
in relation to Nature and the History
of Man," 48, 67 ; Varenius (Bernhard),
General and Comparative Geography,
66, 67.

Gerard, Capts. A. G. and J. G., on the
snow-line and vegetation of the Hima-
layas, 31, 32, 331, 332.

German scientific works, their defects,
47.

Geyser, intermittent fountains of, 222.

Gieseke on the Aurora, 200.

Gilbert, Sir Humphrey, Gulf Stream, 307.

Gilbert, William, of Colchester, terres-
trial magnetism, 158, 159, 177, 179, 182.

Gillies, Dr., on the snow-line of South
America, 330, 331.

Gioja, crater of, 98.

Girard, composition and texture of ba-
salt, 253.

Glaisher, James, on the Aurora Boreahs
of Oct. 24, 1847. See Translator's notes,
194, 200.

Goldfuss, Professor, examination of fossil
specimens of the flying saurians, 274.

Goppert on the conversion of a fragment
of amber-tree into black coal, 281 ; cy-
cadese, 283 ; on the amber-tree of the
Baltic, 283, 284,

Gothe, 41. 47, 53.

Greek philosophers, their use of the term
Cosmos, 69, 70; hypotheses on aero-
lites, 122, 123, 134,

Grimm, Jacob, graceful symbolism at-
tached to falling stars in the Lithuanian
mythology, 112, 113.

Gulf Stream, its origin and course, 307.

Gumprecht, pyroxenic nepheline, 253.

Guanaxuato, striking subterranean noise
at, 209.

Hall, Sir James, his experiments on min-
eral fusion, 262.

Halley, comet, 43, 100, 102-109; on the
meteor of 1686, 118, 133 ; on the light
of stars, 152 ; hypothesis of the earth
being a hollow sphere, 171 ; his bold
conjecture that the Aurora Boreahs was
a magnetic phenomenon, 193.

Hansteen on magnetic lines of declination
in Northern Asia, 182.

Hansen on the material contents of the
moon, 96.

Hedenstrom on the so-called "Wood
Hills" of New Siberia, 281.

Hegel, quotation from his "Philosophy
of History," 76.

Heine, discovery of crystals of feldspar
in scoriae, 268.

Hemmer, falling stai-s, 119.

Hencke, planets discovered by. See note
by Translator, 90, 91.

Henfrey, A., extract from his Outhnes of
Structural and Physiological. Botany
See notes by Translator, 341, J42, 351,

368

COSMOS

Hensius on the variations of form in the
comet of 1744, 102.

Herodotus, described Scythia as free from
earthquakes, 204 ; Scythian saga of the
sacred gold, which fell burning from
heaven, 115.

Herschel, Sir William, map of the world,
66 ; inscription on his monument at Up-
ton, 87 ; satellites of Saturn, 96 ; diam-
eters of comets, 101 ; on the comet of
1811, 103; star guagings, 150; starless
epace, 150, 152 ; time required for light
to pass to the earth from the remotest
luminous vapor, 154.

Herschel, Sir John, letter on Magellanic
clouds, 85 ; satellites of Saturn, 96 ; or-
bits of the satellites of Uranus, 98 ; di-
ameter of nebulous stars, 141 ; stellar
Milky Way, 150, 151 ; light of isolated
starry clusters, 151 ; observed at the
Cape, the star 17 in Argo increase in
splendor, 153 ; invariability of the mag-
netic declination in the West Indies. 181.

Hesiod, dimensions of the universe, 154.

Ilevelius on the comet of 1618, 106.

Hibbert, Dr., on the Lake of I.aach. See

note by Translator, 218.
.Himalayas, the, their altitude, 28; scen-
ery and vegetation, 29, 30; tempera-
ture, 30, 31 ; variations of the snow-line
on their northern and southern decliv-
ities, 30-33, 331.

Hind, Mr., planets discovered by. See
Translator's note, 90, 91.

Hindoo civihzation, its primitive seat, 35,
36.

Hippalos, or monsoons, 316.

Hippocrates, his erroneous supposition
that the land of Scythia is an elevated
table-land, 346.

Hoff, numerical Inquiries on the distri-
bution of earthquakes throughout the
year, 207.

Hoftman, Friedrich, observations on earth-
quakes, 206, 207 ; on eruption fissures
in the Lipari Islands, 238.

Holberg, his Satire, " Travels of Nic. Klim-
ius, in the world under ground." See
Translators note, 171, 172.

Hood on the Aurora, 200, 201.

Hooke, Robert, pulsations in the tails of
comets, 143 ; his anticipation of the ap-
plication of botanical and zoological
evidence to determine the relative age
of rocks, 270-272.

Ho-tsings, Chinese fire -springs, their
depth, 158; chemical composition, 217.

Howard on the climate of London, 125 ;
mean annual quantity of rain in Lon-
don, 333.

Hiigel, Carl von, on the elevation of the
valley of Kashmir, 32, 33 ; on the snow-
Une of the Himalayas, 331.

Humboldt, Alexander von, works by, re-
ferred to in various notes :
Annales de Chimie et de Physique,

31, 305.
Annales des Sciences Naturelles, 28.
Ansichten der Natur, 342, 344, 347.
Asie Centrale, 28, 31, 33, 115, 158. ISS,

180, 204, 217, 219, 225, 245, 251, yy-t
260, 289, 290, 291, 292, 296, 300, 301,
303-306, 320, 323, 324, 330, 331, 334,
350, 356.
Atlas G6ographique et Physique du

Nouveau Continent, 33, 249.
De distributione Geographic^ Plan-
tarum, secundum cceli temperiem,
et altitudinem Moutium, 33, 291,
324.
Examen Critique de I'Histoire de la
G§ographie, 58, 180, 181, 227 2i9,
292, 307, 308, 310, 316, 356.
Essai Geognostique sur le Gisement

des Roches, 230, 252, 266, 300.
Essai Politique sur la Nouvelle Es

pagne, 129, 240.
Essai sur la Geographic des Plantea,

33, 230, 315.
Flora Friburgensis Subterranea, 340,

346.
Journal de Physique, 178, 292.
Lettre au Due de Sussex, sur les
Moyens propres a perfectionner la
connaissance du Magnetisme Ter-
restre, 176, 192.
Mormmens des Peuples Indigenes de

I'Amerique, 140.
Nouvelles Annales des Voyages, 307.
Recueil d'Observations Astronom

iques, 28, 167, 218, 327.
Recueil d'Observations de Zoologie

et d'Anatomie Compar§e, 232.
Relation Historique du Voyage aux
Regions Equinoxiales, 113, 119, 123,
127, 130, 186, 206, 207, 220, 221, 225,
252, 292, 299, 300, 302, 305-307, 314,
315, 327, 329, 334, 336.
Tableau Physique des Regions Equi

noxiales, 33, 230.
Vues des Cordilleres, 225, 230.
Humboldt, Wilhelm von, on the primitive
seat of Hindoo civilization, 36 ; sonnet,
extract from, 154 ; on the gradual rec-
ognition by the human race of the bond
of humanity, 358, 359.
Humidity, 313, 332-335.
Hutton, Capt. Thomas, his paper on the

snow-line of the Himalayas, 331, 332.
Huygens, polarization of light, 52 ; nebu-
lous spots, 1,38.
Hygrometry, 332, 333 ; hygrometric wind-
rose, 333.

Imagination, abuse of, by half-civiUzed na-
tions, 37.

Imbert, his account of Chinese " fire--
springs," 158.

Ionian school of natural philosophy, 65,
77, 84, 134.

Isogenic, isoclinal, isodynamic, &c. See
Lines.

Jacqueraont, Victor, his barometrical oh
servations on the snow-line of the Him
alayas, 32, 331.

Jasper, its i'crmation, 259-261.

Jessen on the gradual rise of the coast of
Sweden, 295.

Jorullo, hornitos de, 230.

INDEX.

369

Justinian, conjectures on the physical
causes of volcanic eruptions, 243.

Kamtz, isobarometric lines, 315; doubts
on the greater dryness of mountain air,
334.

Kant, Emanuel, "on the theory and struc-
ture of the heavens," 50, 65 ; earth-
quake at Lisbon, 2i0.

Keilhau on the ancient sea-line of the
coast of Spitzbergen, 296.

Kepler on the distances of stars, 88; on
the density of the planets, 93 ; law of
progression, 95 ; on the number of com-
ets, 99 ; shooting stars, 113 ; on the ob-
scuration of the sun's disk, 132 ; on the
radiations of heat from the tixed stars,
136 ; on a solar atmosphere, 139.

Kloden, shooting stars, 119, 124.

Knowledge, superficial, evils of, 43,

Krug of Nidda, temperature of the Gey-
ser and the Strokr intermittent fount-
ains, 222.

Krusenstern, Admiral, on the train of a
fire-ball, 114.

Kuopho, a Chinese physicist, on the at-
traction of the magnet, and of amber,
188.

Kupfter, magnetic stations in Northern
Asia, 191.

Lamanon, 187.

Lambert, suggestion that the direction of
the wind be compared with the height
of the barometer, alterations of temper-
ature, humidity, &c., 315.

Lamont, mass of Uranus, 93 ; satellites of
Saturn, 96.

Language and thought, their mutual alli-
ance, 56 ; author's praise of his native
language, 56.

Languages, importance of their study,
357, 359.

Laplace, his "Systdme du Monde," 48,
62, 92, 141 ; mass of the comet of 1770,
107; OH the required velocity of masses
projected from the Moon, 121, 122 ; on
the altitude of the boundaries of the at-
mosphere of cosmical bodies, 141 ; zo-
diacal Ught, 141; lunar inequalities, 166;
the Earth's form and size inferred from
lunar inequalities, 168, 169; his estimate
of the mean height of mountains, 301 ;
density of the ocean required to be less
than the earth's for the stability of its
equilibrium, 305 ; results of his perfect
theory of tides, 306.

Latin writers, their use of the term "Mun-
dus," 70, 71.

Latitudes, Northern, obstacles they pre-
sent to a discovery of the laws of Na-
ture, 36 ; earliest acquaintance with the
governing forces of the physical world,
there displayed, 36 ; spread from thence
of the germs of civilization, 36.

Latitudes, tropical, their advantages for
the contemplation of nature, 33; pow-
erful impressions, from their organic
richness and fertility, 34 ; facilities they
present for a knowledge of the law* of

Q

nature, 35 ; brilliant display of shooting
stars, 113.

Laugier,his calculations to prove Halley's
comet identical with the comet of 1378,
described in Chinese tables, 109.

Lava, its mineral composition, 234.

Lavoisier, 62.

Lawrence (St.), fiery tears, 124 ; meteoric
stream, 125.

Leibnitz, his conjecture that the planets
increase in volume in proportion to
their increase of distance from the
Sun, 93.

Lenz, observations on the mean level of
the Caspian Sea, 297 ; maxima of dens-
ity of the oceanic temperature, 304 ,
temperature and density of the ocean
under ditterent zones of latitude and
longitude, 306.

Leonhard, Kai'l von, assumption on for*
mations of granular limestone, 263.

Leverrier, planet Neptune. See Trans-
lator's note, 90, 91.

Lewy, observations on the varying quan-
tity of oxygen in the atmosphere, ac-
cording to local conditions, or the sea-
sons, 311, 312.

Lichtenberg, on meteoric stones, 118.

Liebig on traces of ammoniacal vapors ia
the atmosphere, 311.

Light, chromatic polarization of, 52 ; trans-
mission, 88 ; of comets, 104-106; of fix-
ed stars, 105 ; extraordinary lightness,
instances of, 142-144 ; propagation of,
153 ; speed of transit, 153, 154. See Au-
rora. Zodiacal Light, &c.

Lignites, or beds of brown coal, 283, 284.

Lines, isogonic (magnetic equal devia-
tion), 177, 181-185; isoclinal (magnetic
equal inclination), 178, 179, 181-185 ;
isodynamic (or magnetic equal force),
181, 185-194 ; isogeothermal (chthoniso-
thermal), 219 ; isobarometric, 315 ; iso-
thermal, isotheral, and isochimenal, 317,
327, 328, 348.

Line of no variation of horary declination,
183 ; lower limit of perpetual snow, 329-
332; phosphorescent, 113.

Lisbon, earthquake of, 210, 211, 213, 214.

Lord on the limits of the snow-line on the
Himalayas, 32.

Lottin, his observations of the Aurora,
with Bravais and Siljerstrom, on the
coast of Lapland, 195, 200, 201.

Lowenorn, recognized the coruscation of
the polar light in bright sunshine, 196.

Lyell, Charles, investigations on the nu-
merical relations of extinct and organ-
ic life, 274, 275 ; nether-formed or hyp-
ogene rocks, 249 ; uniformity of the prO'
duction of erupted rock.s, 257. See notes
by Translator, 203, 244, 257.

Mackenzie, description of a remarkable
eruption in Iceland, 236.

Maclear on a Centauri, 88 ; parallaxes
and distances of ^.xed stars, 153 ; in-
crease in brightness of ;; Argo, 1 53.

Madler, planetary compression of Uranus,
96 ; distance of the innermost satellite

2

370

C0SM03.

of Saturn from the center of that planet,
97; material contents of the Moon, 96;
its libration, 98; mean depression of
temperatiire on the three cold days of
May (llth-13th), 133; conjecture that
the average mass of the larger number
of binary stars exceeds the iiass of the
Sun, 149.
Magellanic clouds, 85.
Magnetic attraction, 188; declination, 181-
183 ; horary motion, 177-180 ; horary
variations, 183, 190; magnetic storms,
177, 179, 195, 199; their intimate con-
nection with the Aurora, 193-201 ; rep-
resented by three systems of hues, see
Lines ; movement of oval systems, 182;
magnetic equator, 183-185 ; magnetic
poles, 183, 184; observatories, 190-192 ;
magnetic stations, 190, 191, 317.
Magnetism, terrestrial, 177-193, 201 ; elec-
tro, 177-191.
Magnussen, Soemund, description of re-
markable eruption in Iceland, 236.
Mahlmann, Wilhelm, southwest direction
of the aerial current in the middle lati-
tudes of the temperate zone, 317.
Mairan on the zodiacal light, 138, 139, 142;
his opinion that the Sun is a nebulous
star, 141.
Malapert, annular mountain, 98.
Malle, Dureau de la, 223.
Man, general view of, 351-359 ; proofs of
the flexibility of his nature, 27 ; results
of his intellectual progress, 53, 54 ; ge-
ographical distribution of races, 351-
356 ; on the assumption of superior
and inferior races, 351-358 ; his gradu-
al recognition of the bond of humanity,
358, 359.
Mantell, Dr., his " Wonders of Geology,"
see notes by Translator, 45, 64, 203, 274,
278, 281, 283,284, 287; "Medals of Cre-
ation," 46, 271, 283, 287.
Margarita Philosophica by Gregory

Reisch, 58.
Marius, Simon, first described the nebu-
lous spots in Andromeda and Orion,
138.
Martins, observations on polar bands, 198 ;
found that air collected at Faulhorn con-
tained as much oxygen as the air of Par-
is, 312; on the distribution of the quan-
tity of rain in Central Europe, 333 ;
doubts on the greater dryness of mount-
ain air, 334.
Matthiessen, letter to Arago on the zodi-
acal light, 142.
Mathieu on the augmented intensity of
the attraction of gravitation in volcanic
islands, 167.
Mayer, Tobias, on the motion of the solar

system, 146, 148.
Mean numerical values, their necessity

in modern physical science, 81.
Melloni, his discoveries on radiating heat

and electro-magnetism, 49.
Menzel, unedited work by, on the flora

of Japan, 347.
Messier, comet, 108 ; nebulous spot re-
sembling our starry stratum, 151.

Metamorphic Rocks. See Recks.

Meteorology, 311-339.

Meteors, see Aerolites ; meteoric infuso
ria, 345, 346.

Methone, Hill of, 240.

Meyen on forming a thermal scale of cul
tivation, 324 ; on the reproductive or
gans of liverworts and algie, 341.

Meyer, Hermann von, on the organization
of flying saurians, 274.

Milky Way, its figure, 89 ; views of Aris-
totle on, 103 ; vast telescopic breadth,
150 ; Milky Way of nebulous spots at
right angles with that of the stars, 151.

Minerals, artificially formed, 268, 269.

Mines, gi-eatest dacth of, 157-159 ; tem-
perature, 158.

Mist, phosphorescant, 142.

Mitchell, protracted earthquake shocks in
North America, 211.

Mitscherlich on the chemical origin of
iron glance in volcanic masses, 234;
chemical combinations, a means of
throwing a clear light on geognosy, 256 ;
on gypsum, as a uniaxal crystal, 259 ,
experiments on the simultaneously op-
posite actions of heat on crystalline
bodies, 259; formation of crystals of
mica, 260; on artificial mineral prod-
ucts, 268, 271.

Mofettes (exhalations of carbonic acid
gas), 215-219.

Monsoons (Indian), 316, 317.

Monticelli on the current of hydrochloric
acid from the crater of Vesuvius, 235 ;
crystals of mic-a found in the lava of
Vesuvius, 260.

Moon, the, its relative magnitude, 96 ;
density, 96 ; distance from the earth,
97 ; its libration, 98, 163 ; its light com-
pared with that of the Aurora, 201, 202 :
volcanic action in, 228.

Moons or satellites, their diameter, dis-
tances, rotation, &c., 95-99.

Morgan, John H., " on the Aurora Bore-
alis of Oct. 24, 1847." See Translator's
notes, 194, 199.

Morton, Samuel George, his magnificent
work on the American Races, 362.

Moser's images, 202.

Mountains, in Asia, America, and Europe,
their altitude, scenery, and vegetation,
27-30, 228, 347 ; their influence on cli-
mate, natural productions, and on the
human race, its trade, civilization, and
social condition, 291, 292, 299, 300, 327
zones of vegetation on the declivitiej
of. 29, 30, 327-329 ; snow-line of, 30-33
330, 331.

Mud volcanoes. See Salses and Volca-
noes.
Miiller, Johannes, on the modification!
of plants and animals within certain
limitations, 353.

Muncke on the appearance of Auroras in
certain districts, 198.

Murchison, Sir R., account of a large fis-
sure through which melaphyre had
been ejected, 258 ; classification of f js-
siliferous strata, 277 ; on the age of the

INDEX.

371

PalaBosaurus and Thecodontosaurus of

Bristol, 274.

Muschenbroek on the frequency of mete-
ors in August, 125.

Myndius, Apollonius, on the Pythagorean
doctrine of coraefs, 103, 104

Nature, result of a rational inquiry intOj
25; emotions excited by her contem-
plation, 25; striking scenes, 26; their
sources of enjoyment, 26, 27 ; magnifi-
cence of the tropical scenery, 33, 34, 35,
344 ; religious impulses from a com-
munion with nature, 37; obstacles to
an active spirit of inquiry, 37 ; mischief
of inaccurate observations, 38 ; higher
enjoyments of her study, 38 ; narrow-
minded views of nature, 38 ; lofty im-
pressions produced on the minds of la-
borious observers, 40 ; nature defined,
41; her studies inexhaustible, 41 ; gen-
eral observations, their great advanta-
ges, 42; how to he correctly compre-
hended, 72 ; her most vivid impressions
earthly, 82.

Jiature, philosophy of, 24, 37; physical
description of, 66, 67. 73.

Nebulae, 84-86 ; nebulous Milky Way at
right angles with that of the stars, 150-
153 ; nebulous spots, conjectures on,
83-86 ; nebulous stars and planetary
nebulai, 85, 151, 152; nebulous vapor,
83-86, 87, 152 ; their supposed conden-
sation in conformity with the laws of
attraction, 84.

Neilson, gradual depression of the south-
ern part of Sweden, 295.

Nericat, Andrea de, popular belief in Syr-
ia on the Jail of aerolites, 123.

Newton, discussed the question on the dif-
ference between the attraction of mass-
es and molecular attraction, 63 ; New-
tonian axiom confirmed by Bessel, 64 ;
his edition of the Geography of Vareni-
us, 66 ; Principia Mathematica, 67 ; con-
sidered the planets to be composed of
the same matter with the Earth, 132 ;
compression of the Earth, 165.

KichoU, J. P., note from his account of the
planet Neptune, 90, 91.

Nicholson, observations of lightning
clouds, unaccompanied by thunder or
indications of storm, 337.

Nobile, Antonio, experiments of the height
of the barometer, and its influence on
the level of the sea. 298.

Noggerath counted 792 annual rings in the
trunk of a tree at Bonn, 283.

Nordmann on the existence of animal-
cules in the fluids of the eyes of fishes,
345.

Norman, Robert, invented the inclinato-
rium, 179,

Observations, scientific, mischief of in-
accurate, 38 ; tendency of unconnect-
ed, 40.

Ocean, general view of) 292-311 ; its ex-
tent as compared with the dryland, 288
289; its depth. 160, 302 ; tides, 305. 306 ;

decreasing temperature at increased

depths, 302 ; uniformity and constancy
of temperature in the same spaces, 303";
its currents and their various causes,
306-309 ; its phosphorescence in the
torrid zone, 202 ; its action on climate,
?03, 319-329 ; influence on the mental
and social condition of the human race,
162, 291, 292, 294, 310; richness of its
organic life. 309, 310; oceanic micro-
scopic forms, 342, 343 ; sentiments ex-
cited by its contemplation, 310.

CErsted, electro-magnetic discoveries,
188, 191.

Gibers, comets, 104, 109 ; aerolites, 114,
118 ; on their planetary velocity, 121 ;
on the supposed phenomena of ascend-
ing shooting stars, 123 ; their periodic re-
turn in August, 125 ; November stream,
126 ; prediction of a brilliant fall of shoot-
ing stars in Nov., 1867, 127 ; absence of
fossil meteoric stones in secondary and
tertiary formations, 131 ; zodiacal light,
its vibration through the tails of com-
ets, 143 ; on the transparency of celes-
tial space, 152.

Olmsted, Denison, of New Haven, Con-
necticut, observations of aerohtes, 113,
118, 119, 124.

Oltmanns, Herr, observed continuously

_ with Humboldt, at BerUn, the move-
ments of the declination needle, 190,
191.

Ovid, his description of the volcanic Hil]
of Methone, 240.

Oviedo describes the weed of the Gulf
Stream as Praderias de yerva (sea
weed meadows), 308.

Palaeontology, 270-284.

Pallas, meteoric iron, 131.

Palmer, New Haven, Connecticut, on the
prodigious swarm of shooting stars,
Nov. 12 and 13, 1833, 124; on the non-
appearance in certain years of the Au-
gust and November fall of aerolites,
129.

Parallaxes of fixed stars, 88, 89 ; of the so-
lar system, 145, 146.

Parian and Carrara raarbles, 262, 263.

Parry, Capt., on Auroras, their connection
with magnetic perturbations, 197, 201
whether attended with any sound, 200
seen to continue throughout the day,
197 ; barometric observation at Port
Bowen, 314, 315 ; rarity of electric ex-
plosions in northern regions, 337.

Patricius, St., his accurate conjectures on
the hot springs of Carthage, 223, 224. ■

Peltier on the actual source of atmos-
pheric electricity, 335, 336.

Pendulum, its scientific uses, 44 ; experi-
ments with, 64, 166, 169, 170 ; employed
to investigate the curvature of the
earth's surface, 165; local attraction, its
influence on the pendulum, and geog-
nostic knowledge deduced from, 44, 45,
167,. 168 ; experiments of Bessel, 64.

Pentland, his measurements of the Andoa^

372

COSMOS.

Percy, Dr., on minerala artificially pro-
duced. See note by Translator, 268.

Permitin system of Murchison, 277.

Perouse, La, expedition of, 186.

Persia, great comet seen in (1668), 139,
140.

Pertz on the large aerolite that fell in the
bed of the Rivei- Nami, 116.

Peters, Dr., velocity of stones projected
from JEtna, 122.

Peucati, Count Mazari, partial infection
of calcareous beds by the contact of
syenitic granite in the Tyrol, 262.

Phillips on the temperature of a coal-
mine at increasing depths, 174.

Philolaiis, his astronomical studies, 65;
his fragmentary writings, 68-71.

Philosophy of nature, first germ, 37.

Phosphorescence of the sea in the torrid
zones, 202.

Physics, their limits, 50 ; influence of phys-
ical science on the wealth and prosper-
ity of nations, 53 ; province of physical
science, 59 ; distinction between the
physical history and physical descrip-
tion of the world, 71, 72 ; physical sci-
ence, characteristics of its modern prog-
ress, 81.

Pindar, 227.

Plana, geodesic experiments in Lombar-
dy, 168.

Planets, 89-99; present number discov-
ered, 90. (See note by Translator on
the most recent discoveries, 90, 91) ; Sir
Isaac Newton on their composition, 132 ;
limited physical knowledge of, 156, 157 ;
Ceres, 64-92; Earth, 88-99; Juno, 64,
92-97, 106; Jupiter, 64, 87, 92-98. 202;
Mars, 87, 91-94, 132 ; Mercury, 87, 92-
94 ; Pallas, 64, 92 ; Saturn, 87, 92-94 ;
Venus, 91-94, 202; Uranus, 90-94 ; plan-
ets which have the -largest number of
moons, 95, 96.

Plants, geographical distribution of, 346-
350.

Plato on the heavenly bodies, &c., 69 ; in-
terpretation of nature, 163; his geog-
nostic views on hot springs, and" vol-
canic igneous streams, 237, 238.

Pliny the elder, his Natural History, 73 ;
on comets, 104 ; aerolites, 122, 123, 130;
magnetism, 180; attraction of amber,
188 ; on earthquakes, 205, 207 ; on the
flame of inflammable gas, in the district
of Phasehs, 223 ; rarity of jasper, 261 ;
on the configuration of Africa, 292.

Pliny the younger, his description of the
great eruption of Mount Vesuvius, and
the phenomenon of volcanic ashes, 235.

Plutarch, truth of his conjecture that fall-
ing stars are celestial bodies, 133, 134.

Poisson on the planet Jupiter, 64 ; conjec-
ture on the spontaneous ignition of me-
teoric stones, 118; zodiacal light, 141-;
theory on the earth's temperature, 172,
173, 174, 176. 177.

Polarization, chromatic, results of its dis-
covery, 52 ; expei iments on the Ught of
comets, 105, 106.

Polybius. 291.

Posidoaius on the Ligyan field of stouea,
115, 116.

Pouillet on the actual source of atmos-
pheric electricity, 335.

Prejudices against science, how originat-
ed, 38 ; against the study of the exact
sciences, why fallacious, 40, 52.

Prichard, his physical history of Man-
kind, 352.

Pseudo-Plato, 54.

Psychrometer, 332, 338.

Pythagoras, first employed the word Cos
mos in its modern sense, 69.

Pythagoreans, their study of the heavenly
bodies, 65 ; doctrine on comets, 103.

Quarterly Review, article on Terrestrial

Magnetism, 192.
Quetelet on aerolites, 114 ; their periodic

return in August, 125.

Races, human, their geographical distri
bution, and unity, 351-359.

Rain drops, temperature of, 220 ; mean an
nual quantity in the two hemispheres,
333, 334.

Reich, mean density of the earth, as as
certained by the torsion balance, 170 ;
temperature of the mines in Saxony,
174.

Reisch, Gregory, his "Margarita Philo-
sophica," 58.

R6rausat, Abel, Mongolian tradition on the
fall of an aerolite, 116 ; active volcanoes
in Central Asia, at great distances from
the sea, 245.

Richardson, magnetic phenomena attend
ing the Aurora, 197; whether accom-
panied by sound, 200 ; in^jience on the
magnetic needle of the Aurora, 201.

Riobamba, earthquake at, 204, 206, 208,
213, 214.

Ritter, Carl, his " Geography in relation
to Nature and the History of Man," 48,
67.

Robert, Eugene, on the ancient sea-line on
the coast of Spitzbergen, 296.

Robertson on the permanency of the com-
pass in Jamaica, 181.

Rocks, their natui-e and configuration,
228 ; geognostical classification into four
groups, 248-251 ; i. rocks of eruption,
248, 251-253 ; ii. sedimentary rocks, 248^
254, 255 ; iii. transformed, or meta-
morphic rocks, 248, 249, 255, 256-269 ;
iv. conglomerates, or rocks of detritus,
269, 270 ; their changes from the action
of heat, 258, 259 ; phenomena of con-
tact, 258-267 ; effects of pressure and
the rapidity of cooling, 258, 267.

Rose, Gustav, on the chemical elements,
(fee, of various aerolites, 131 ; on the
structural relations of volcanic rocks,
234 ; on crystals of feldspar and albite
found in granite, 251 ; relations of posi-
tion in which granite occurs, 252-269 ,
chemical process in the formation of
various minerals, 265-269.

Ross, Sir James, his soundings with 27,600
feet of line, 160; magnetic observations

INDEX.

373

at the South Pole, 187; important re-
sults of the Antarctic magnetic expedi-
tion in 1839, 192 ; rarity of electric ex-
plosions hi high northern regions. 337.

Rossell, M. de, his magnetic oscillation
experiments, and their date of publi-
cation, 186, 187.

Jtothmann, confounded the setting zodi-
acal light with the cessation of twilight,
143.

Jlozier, observation of a steady luminous
appearance in the clouds, 202.

Riimker, Encke's comet, 106.

Riippell denies the existence of active
volcanoes in Kordofan, 245.

'abine, Edward, observations on days of
unusual magnetic disturbance, 178 ; re-
cent magnetic observations, 184, 18^,
187, 188.
tegra, Ramon de la, observations on the
mean annual quantity of rain in the
Havana, 333.
feint Pierre, Bernardin de, Paul and Vir-
ginia, 26 ; Studies of Nature, 347.
Jalses or mud volcanoes, 224-228 ; strik-
ing phenomena attending their origin,
224, 225.

jalt- works, depth of, 158, 159 ; tempera-
ture, 174.
Tantorino, the most important of the isl-
ands of eruption, 241, 242; description
t»f. See note by Translator, 241.
• lai'gasso Sea, its situation, 308.

6a';ellite3 revolving round the primary
planets, their diameter, distance, rota-
tion, &c., 94, 99; Saturn's, 96-98, 127;
Earth's, see Moon, Jupiter's, 96, 97;
\Jranus, 96-98.

Mdarians, flying, fossil remains of, 274,
:!75.

Sa assure, measurements of the marginal
ledge of the crater of Mount Vesuvius,
il32; traces of ammoniacal vapors in
Ihe atmosphere, 311 ; hygrometric
measurements with Humboldt, 334-336.

Scaayer, microscopic organisms in the
ocean, 342, 343.

Scheerer on the identity of eleolite and
nepheline, 253.

Schelling on nature, 55 ; quotation from
his Giordino Bruno, 77.

Scheuchzner's fossil salamander, conjec-
tured to be an antediluvian man, 274.

Schiller, quotation from, 36.

Schnurrer on the obscuration of the sun's
disk. 133.

Schouten, Cornelius, in 1616 found the
declination null in the Pacific, 182.

Scbouw, distribution of the quantity of
rain in Central Europe, 333.

Schrieber on the fragmentary character
of meteoric stones, 117.

Scientific researches, their frequent re-
sult, 50 ; scientific knowledge a require-
ment of the present age, 53, 54 ; scien-
tific terms, their vagueness and misap-
plication, 58, 68.

Bcina, Abbate, earthquakes unconnected
with the state of the weather, 206i 207.

Scoresby, rarity af electric explosions la
high northern regions, 337.

Sea. See Ocean.

Seismometer, the, 205

Seleucus of Erythrea, h^s astronomical
studies, 65.

Seneca, noticed the direction of the tail*
of comets, 102 ; his views on the nature
and paths of comets, 103, 104 ; omens
drawn from their sudden appearance,
111 ; the germs of later observations on
earthquakes found in his writings, 207 ;
problematical extinction and sinking of
Mount ^tna, 227, 240.

Shoals, atmospheric indications of their
vicinity, 309.

Sidereal systems, 89, 90.

Siljerstrom, his observations on the Au-
rora, with Lottin and Bravais, on the
coast of Lapland, 195.

Sirowatskoi, " Wood Hills" in New Sibe-
ria, 281-

Snow-line of the Himalayas, 30-33, 331,
332 ; of the Andes, 330 ; redness of long-
fallen snow, 344.

Solar system, general description, 90-154 ;
its position in space, 89 ; its translatory
motion, 145-150. •

Solinus on mud volcanoes, 225.

Sommering on the fossil remains of the
large vertebrata, 274.

Somerville, Mrs., on the volume of fire-
balls and shooting stars, 116 ; faintness
of light of planetary nebulae, 141.

Southern celestial hemisphere, its pictur-
esque beauty, 85, 86.

Spontaneous generation, 345, 346.

Springs, hot and cold, 219-225 ; intermit-
tent, 219 ; causes of their temperature,
220-222; thermal, 222, 345; deepest
Artesian wells the warmest, observed
by Arago, 223; salses, 224-226; influ-
ence of earthquake shocks on hot
springs, 210, 222-224.

Stars, general account of, 85-90; fixed,
89. 90, 104; double and multiple, 89,
147; nebulous, 85, 86, 151, 152; their
translatory motion, 147-150; parallaxes
and distances, 147-149 ; computations
of Bessel and Herschel on their diame-
ter and volume, 148 ; immense number
in the Milky Way, 150, 151 ; star dust,
85 ; star gaugings, 150 ; starless spaces,
150, 152 ; telescopic stars, 152 ; velocity
of the propagation of light of, 153, 154 ;
apparition of new stars, 153.

Storms, magnetic and volcanic. See
Magnetism, Volcanoes.

Strabo, observed the cessation of shocks
of earthquake on the eruption of lava,
215 ; on the mode in which islands are
formed, 227 ; description of the Hill of
Methone, 240; volcanic theory, 243;
divined the existence of a continent in
the northern hemisphere between The-
ria and Thine, 289 ; extolled the varied
form of our small continent as favorable
to the moral and intellectual develop-
ment of its people, 291, 292.

Struve, Otho, on the proper motion of the

374

COSMOS.

Bolar system, 146 ; investigations on the
propa2;ation of light, 153; parallaxes
and distances of fixed stars, 153 ; ob-
servations on Halley's comet, 105.

Studer, Professor, on mineral metamorph-
ism. See note by Translator, 248i

Sun, magnitude of its volume compared
with that of the fixed stars, 136 ; obscu-
ration of its disk, 132 ; rotation round
the center of gravity of the whole solar
system, 145 ; velocity of its translatory
motion, 145 ; narrow limitations of its
atmosphere as compared with the nu-
cleus of other nebulous stars, 141 ; "sun
stones" of the ancients, 122 ; views of the
Greek philosophers on the sun, 122.

Bymond, Lieut., his trigonometrical sur-
vey of the Dead Sea, 296, 297.

Tacitus, distinguished local climatic rela-
tions from those of race, 352.

Temperature of the globe, see Earth and
Ocean ; remarkable uniformity over
the same spaces of the surface of the
ocean, 303 ; zones at which occur the
maxima of the oceanic temperature,
304^ causes which raise the tempera-
ture, 319 ; causes which lower the tem-
perature, 319, 320; temperature of va-
rious places, annual, and in the difler-
ent seasons, 322, 323-328 ; thermic scale
of temperature, 324, 325 ; of continental
climates as compared with insular and
Uttoral climates, 321, 322 ; law of de
crease with increase of elevation, 327
depression of, by shoals, 309 ; refrigera
tion of the lower strata of the ocean, 303

Teneritle, Peak of, its striking scenery, 26

Theodectes of Phasehs on the color of the
Ethiopians, 353.

Theon of Alexandria described comets as
" wandering light clouds," 100.

Theophylactus described Scythia as free
from earthquakes, 204.

Thermal scales of cultivated plants, 324,
325.

Thermal springs, their temperature, con-
stancy, and change, 221-224 ; animal
and vegetable life in, 345.

Thermometer, 338.

Thibet, habitability of its elevated pla-
teaux, 331, 332.

Thienemann on the Aurora, 197, 200.

Thought, results of its free action, 53, 54 ;
union with language, 56.

Tiberias, Sea of, its depression below the
level of the Mediterranean, 296.

Tides of the ocean, their phenomena, 305,
306.

Tillard, Capt, on the sudden appearance
of the island of Sabrina, 242.

Tournefort, zones of vegetation on Mount
Ararat, 347.

Tralles, his notice of the negative electric-
ity of the air near high waterfalls, 336.

Translator, notes by, ^ ; on the increase
of the earth's internal heat with increase
of depth, 45 ; silicious infusoria and an-
imalculites, 46 , chemical analysis of an
aerolite, G4 • on the recent discoveries

of planets, 90, 91 ; observed the cornel

of 1843, at New Bedford, Massachusetts,
in bright sunshine, 101 ; on meteoric
stones. 111 ; on a MS., said to be in the
library of Christ's College, Cambridge,
124 ; on the term " salses," 161 ; on Hol-
berg's satire, " Travels in the World
under Ground," 171 ; on the Aurora Bo-
realis of Oct. 24, 1847, 194, 195, 199 ; on
the electricity of the atmosphere dur-
ing the Aurora, 200 ; on volcanic phe-
nomena, 203, 204 ; description of the
seismometer, 205 ; on the great earth •
quake of Lisbon, 210 ; impression made
on the natives and foreigners by earth-
quakes in Peru, 215; earth'quakes at
Lima, 216, 217 ; on the gaseous com-
pounds of sulphur, 217, 218; on the
>Lake of Laach, its craters, 218 ; on the
emissions of inflammable gas in the dis-
trict of Phaselis, 223 ; on true volcanoes
aa distinguished from salses, 224 ; on
the volcano of Pichincha, 228 ; on the
hornitos de Jorullo, as seen by Hum-
boldt, 230 ; general rule on the dimen-
sions of craters, 230 ; on the ejection of
fish from the volcano of Imbaburu, 233 ;
on the little isle of Volcano, 234 ; vol-
canic steam of Pantellaria, 235; on Dau-
beney's work " On Volcanoes," 236 ; ac-
count of the island of Santorino, 241 ;
of the island named Sabrina, 242 ; on
the vicinity of extinct volcanoes to the
sea, 244 ; meaning of the Chinese term *
"li," 245; on mineral metamorphism,
248 ; on fossil human remains found iu
Guadaloupe, 250 ; on minerals artificial-
ly produced, 267, 268 ; fossil organic
structures, 271, 272 ; on Coprolites, 271 ;
geognostic distribution of fossils, 276 ;
fossil fauna of the Sewalik Hills, 278 ;
thickness of coal measures, 281 ; on the
amber pine forests of the Baltic, 283,
284 ; elevation of mountain chains, 286,
287 ; the dinornis of Owen, 287 ; depth
of the atmosphere, 302 ; richness of or-
ganic life in the ocean, 309; on fila- ,
ments of plants resembling the sperma-
tozoa of animals, 341 ; on the Diatoraa-
cea3 found in the South Arctic Ocean,
343; on the distribution of the floras
and faunas of the British Isles, 348, 349 ;
on the origin and diflusion of the Brit-
ish flora, 353, 354.

Translatory motion of the solar system,
145-150.

Trogus, Pompeius, on the supposed ne-
cessity that volcanoes were dependent
on their vicinity to the sea for their con-
tinuance, 243, 244 ; views of the 'an-
cients on spontaneous generation, 346.

Tropical latitudes, their advantages for
the contemplation of nature, 33 ; pow-
erful impressions frOm their organic-
richness and fertility, 34; facilities they
present for a knowledge of the laws of
nature, 35 ; transparency of the atmos-
phere, 114; phosphorescence of the sea
202.

Techudi, Dr., extract from his " Traveli

INDEX.

375

In Teru." See Translator's note, 215,
216, 217.
Turner, noto on Sir Isaac Newton, 132.

Universality of animated life, 342, 343.

Valz on the comet of 1618, 106.

Varenius, Bernhard, his excellent general
and comparative Geography, 66, 67 ;
edited by Newton, 66.

Vegetable world, as viewed with micro-
scopic powers of -vision, 341; its pre-
dominance over animal life, 343.

Vegetation, its varied distribution on the
earth's surface, 29-31, 62 ; richness and
fertility in the tropics, 3.3-35 ; zones of
vegetation on the declivities of mount-
ains, 29-32, 346-350. See ^tna, Cor-
dilleras, Himalayas, Mountains.

Vico, satellites of Saturn, 96.

Vigne, measurement of I.,adak, 332.

Vine, thermal scale of its cultivation, 324.

Volcanoes, 28, 30, 35, 159, 161, 214, 215,
224-248 ; author's application of the
term volcanic, 45; active volcanoes,
safety-valves for their immediate neigh-
borhood, 214 ; volcanic eruptions, 161,
210-270 ; mud volcanoes or salses, 224-
228 ; traces of volcanic action on the
surface of the earth and moon, 228 ; in-
fluence of relations of height on the oc-
currence of eruptions, 228-2.33 ; vol-
canic storm, 233 ; volcanic ashes, 233 ;
classification of volcanoes into central
and linear, 238 ; theory of the necessity
of their proximity to the sea, 243-246 ;
geographical distribution of still active
volcanoes, 245-247; metamorphic ac-
tion on rocks, 247-249.

Vrolik, his anatomical investigations on
the form of the pelvis, 352, 353.

Wagner, Rudolph, notes on the races of
Africa, 352.

Walter on the decrease of volcanic activ-
ity. 215.

Wartmann, meteors, 113, 114.

Weber, his anatomical investigations on
the form of the pelvis, 353.

Webster, Dr. (of Harvard College, U. S.),
account of the island named Sabrina.
See note by Translator, 242.

Winds, 315-321; monsoons, 316, 317;
trade winds, 320, 321 ; law of rotation,
importance of its knowledge, 315-317.

Wine, on the temperature required for
its cultivation, 324; thermic table of
mean annual heat, 325.

Wollastou on the limitation of the atmos-
phere, 302.

Wrangel, Admiral, on the brilliancy of the
Aurora Borealis, coincident with the
fall of shooting stars, 126, 127; observa-
tions of the Aurora, 197, 200 ; wood hills
of the Siberian Polar Sea, 281.

Xenophanes of Colophon, described com
ets as wandering light clouds, 100; ma-
rine fossils found in marble quarries,
263.

Young, Thomas, earliest observer of the
influence ditierent kinds of rocks exer-
cise on the vibrations of the pendulum,
168.

Yul-sung, described by Chinese writers as
" the realm of pleasure," 332.

Zimmerman, Carl, hypsometrical re
marks on the elevation of the Hima-
layas, 32.

Zodiacal light, conjectures on, 86-92 ;
general account of, 137-144 ; beautiful
appearance, 137, 138 ; first described
in Childrey's Britannia Baconica, 138 ;
probable causes, 141 ; intensity in trop-
ical climates, 142.

Zones, of vegetation, on the declivities of
mountains, 29-33 ; of latitude, their di
versified vegetation, 62 ; of the south'
em heavens, their magnificence, 85, 86,
polar, 197, 198.

vati or VOL. L

I