Price One Shilling.

cosmos:

A SURVEY

GENERAL PHYSICAL HISTORY

OF

THE UNIVERSE.

BY

ALEXANDER VON HUMBOLDT.

NEW-YORK:

HARPER & BROTHERS, PUBLISHERS,

82 CLIFF STREET.

1845.

oil
MORSE'S NEW PICTORIAL GEOGRAPHY.

PRICE FIFTY CENTS.

EMBELLISHED BY NEARLY ONE HUNDRED AND FIFTY ENGRATOGS IND ABOUT FIFTY MAPS.
EXECUTED IN THE NEW CEROGRAPHIC PROCESS.

No equivocal evidence of the great merits ef this popular New School Geography" is afford-
ed by the fact that nearly one hundred thousand copies have been already disposed of within
the brief interval of its publication. It wUl be found one of the most beautiful in its pictorial
embellishments, lucid and simple in its adaptation to the purposes of instruction, as well as
one of the cheapest of all works of the kind ever produced. The maps are both novel and
attractive, being over fifty in number, printed in colours by the new cerographic process.

TESTIMONIALS FROM THE PHILADELPHIA PUBLIC SCHOOLS.

The best work on Geography in the United States or
Great Britain: it should find its way into the Common
Schools and all seminaries of learning in the TJ. States.
Its admirable arrangement and portability render it an ex-
cellent work of referenec ; no person should be without it.

Amdbew Cbozier, Principal of Reed St. Gram. School.

ATaluable acquisition to all engaged either in imparting,
or receiving instruction. Its conciseness and simplicity of
arrangement, and its numerous and beautiful embellish-
ments, eannot fail to render it deservedly popular.

W. H. Pile, Principal qf N. E. Gram. School.

I kave examined with some eare the " Getgraphy^' by
Morse, and can say that I am particularly pleased with it.
I tlunk it clear and concise in its views, and that the maps
and letter-press being in juxtaposition, is a recommendation
Bot likely to be passed by in silence. This arrangement is
calculated to facilitate the progress of the learner, inasmuch
as he has not te look to a separate book for his map : thus
time is gained, and more ground gone over in the same pe-
nod. I would therefwe cheerfully recommend it to all who
ftre in want of such a work.

W. Q. E. Aqnbw, Printipdl of Zane St. Pub. McJiool.

We Gomeur in the opinion with Mr. Agnew.

, James Rhoads, Principal of N. W. Gram. School.
A. T. W. Wbight, Principal of Model School.

I decidedly approve of it ; the facility afforded the pupil
In rrferring to the maps, the correctness of the political di-
visions, and of the population of towns ; the eonciseness of
style and description, and the cheapness, as well as the
neatness and beauty of the typographical exeeution of the
werk are, in my opinion, strong recommendations to the
public. W. W. WooB, Prine^td •f S. W. Gram. Seh.

It i« Ike beat work on ibe subject with whioK I am ao-
qaainted. It has several advantages orer other works of

the kind ; one is, that the map, questions on the map, and
description of each country, are on the same page.
S. F. Watson, Principal of Catherine St. Gram, School.

I cheerfully concur in the above recommendation.
B. E. Chambeblin , Prin. of Buttontoood St. Gram. Seh,

Novelty does not necessarily imply improTement, but in
this instance we have an improvement by which the efforts
of the young pupil will be very much assisted in the acqui
sition of geographical knowledge.

M. S. Cleavenqer, ) Principals of Locust St.

E. H. Cox, J Gram. School.

I have examined the work, and think it well adapted to
the use of schools. Apart from the consideration that its
descriptions are written in a concise, yet perspicuous style,
the convenient general arrangement of the work and its nu-
merons illustrations render it superior to any system of Ge-
ography now in use.

L. e. Smith, Prin. ofJT. Ladies Cram. School, Zone St.

It afR>rd8 me pleasure to recommend it to teachers aa4
the public in general. The arrangement is well planned,
and affords many facilities to the study of geography that
were much desired. The maps are certainly much superior
to any thing of the kind that has yet appeared.

L. Hopper, Principal qf Third Bt. School.

I have no hesitation in assigning to it the first rank among
similar books now in use ; its excellent maps, and beautiful
pictorial illustrations, are calculated to arrest the attention
of the pupil, and impress instruction indelibly on his mem-
ory. Wm. Roberts, Prin. of Moyamensing Gram. Seh.

Having examined " Morsels School Geographyy" wc thiiA

it admirably calculated to carry out the views of its author

P. A. CRKaoB, Principal of S. E. Gram. Sohod

S. D. JOHMSTOIT.
L. N. BOSWELL.

(*^

HARPER & BROTHERS, PUBLISHERS, NEW-YORK.

ANB MAY BK OBTAIHKD OP THK B08K8BLI.BR8 THROUOHOUT TIW VWmV STAraa.

TO THE READER.

In presenting the English public with a version, in the vernacular tongue,
of the world-renow^ned Alexander von Humboldt's Cosmos, the Translator
begs to say, that he has striven to give a faithful transcript of the original, not
less in matter than in manner : he has not taken away from the work, he has
not added to it ; and he has farther done what in him lay to preserve the lofty
tone and imaginative style of the Author.

The Introduction is composed in the manner of an oration or popular dis-
course, and scarcely admitted of so literal a transfusion into English as the
Translator will feel it his duty to secure in the body of the work. The sec-
ond section, on the Limitation and Scientific Treatment of Physical Cosmog-
raphy, is extremely abstruse, and cost the Translator no small pains to ren-
der it, he trusts intelligibly, into English. With the third section— The Pic-
ture of Nature, dtc. — the Author enters fairly on his task.

For the use of several compound words, formed after the German origi-
nals, the Translator has to apologize to the classical English reader, and for
mistakes that may occur in the translation of technical or conventional scien-
tific terms, he must meantime crave the indulgence of the deeply versed in the
several disciplines where these occur. He can but refer to the singular dif-
ficulties of his task, and solicit indulgence*

June 28lA, 1845.

Digitized by tine Internet Archive

in 2008 with funding from

IVIicrosoft .Corporation

http://www.archive.org/details/cosniossurveyofgeOOhumbrich

COSMOS:
SKETCH OF A PHYSICAL HISTORY OF THE UNIVERSE.

INTRODUCTION.

THE VARIOUS SOURCES OF OUR ENJOYMENT IN THE

CONTEMPLATION OF NATURE. THE SCIENTIFIC

FOUNDATION OF THE LAWS THAT GOVERN THE
UNIVERSE.*

In undertaking thus, after so long an absence
from my native country, to discourse with you
freely on the general physical phenomena of
our globe, and to develop the connection of
the forces which actuate the universe, I feel
myself oppressed with a two-fold difficulty.
On one hand, the subject I have to treat is so
vast, and the time allowed me is so short, that
I am fearful either of appearing superficial, or
else, generalizing over much, of proving tire-
some to you through aphoristic brevity. On
the other, the life of action I have led has pre-
pared me indifferently for the duty of a public
teacher ; so that, in the embarrassed state of
my mind, I fear I may not always succeed in
expressing myself with the clearness and pre-
cision which the vastness and the variety of
my subject require. But the realm of nature
is also the realm of freedom ; and to exhibit in
lively characters the ideas and emotions which
a true love of nature inspires, the language
must likewise move in harmony with the dig-
nity and freedom of the subject, and this it is
only given to high mastery to impart.

He who regards the influences of the study
of nature in their relations not to particular
grades of civilization or the individual require-
ments of social life, but in their wider bearings
upon mankind at large, promises himself, as
the principal fruit of his researches, that the
enjoyment of nature will be increased and en-
nobled through insight into the connection of
her phenomena. Such increase, such nobility,
however, is the work of observation, of intelli-
gence, and of time, in which all the efforts of
the understanding of man are reflected. How
the human kind have been striving for thou-
sands of years, amidst eternally recurring chan-
ges in the forms of things, to discover that
which is stable in the law, and so gradually,
by the might of mind, to vanquish all within
the wide-spread orbit of the earth, is familiar
to him who has traced the trunk of our knowl-
edge through the thick strata of bygone ages to
its root. To question these ages is to trace the
mysterious course of the idea stamped with the
same image as that which, in times of remote
antiquity, presented itself to the inward sense
in the guise of an harmoniously ordered whole.
Cosmos, and which meets us at last as the prize
of long and carefully accumulated experience.

* A Discourse delivered on opening the Course of Lec-
tures in the Great Hall of the Singing Academy of Berlin.
Many interpolations belong to a later period.

In these two epochs in the contemplation
of creation — the first dawn of consciousness
among men, and the ultimate and simultaneous
evolution of every element of human science —
two distinct kinds of enjoyment are reflected.
The mere presence of unbounded nature, and
an obscure feeling of the harmony that reigns
amidst the ceaseless changes of her silent work-
ings, are the source of the one. The other be-
longs to a higher stage of civilization of the spe-
cies, and the reflection of this upon the individ-
ual ; it springs from an insight into the order
of the universe, and the co-ordination of the
physical forces. Even as man now contrives
instruments by which he may question nature
more closely, and steps beyond the limited cir-
cle of his fleeting existence ; as he no longer
observes only, but has learned to produce phe-
nomena under determinate conditions ; as, in
fine, the philosophy of nature has doffed hei
ancient poetical garb, and assumed the earnest
character of a thinking impersonation of things
observed, positive knowledge and definition
have taken the place of obscure imaginings and
imperfect inductions. The dogmatical specu-
lations of former ages only exist at present in
the prejudices of the vulgar, or in circumstan
ces where, as if conscious of their weakness,
they willingly keep themselves in the shade.
They also maintain themselves as a heavy in-
heritance in language, which is disfigured by
symbolical words and phrases innumerable. A.
small number only of the elegant creations of
the imagination which have reached us, sur-
rounded as it were with the haze of antiquity,
acquire a more definite outline and a renovated
shape. I

Nature, to the eye of the reflecting observer,
is unity in multiplicity ; it is combination of
the manifold in form and composition ; it is
the conception of natural things and natural
forces as a living whole. The most important
consequences of physical researches are there-
fore these : To acknowledge unity in multipli-
city ; from the individual to embrace all ; amidst
the discoveries of later ages to prove and sep-
arate the individuals, yet not to be overwhelmed
with their mass ; to keep the high destinies of
man continually in view ; and to comprehend
the spirit of nature which lies hid beneath the
covering of phenomena. In this way our aspi-
rations extend beyond the narrow confines of
the world of sense, and we may yet succeed,
comprehending nature intimately, in master-
ing the crude matter of empirical observation
through the might of mind.

When, in the first place, we reflect on the
different degrees of enjoyment which the con-
templation of nature affords, we find that the
first or lowest are independent of all insight

INTRODUCTION.

into the operation of her forces, yea, almost of
the special character of the objects that are
surveyed. "When, for instance, the eye rests
Upon the surface of some mighty plain, covered
with a monotonous vegetation, or loses itself
in the horizon of a boundless ocean, whose
waves are rippling softly to the shore, and
strewing the beach with sea-weed, the feeling
of free nature penetrates the mind, and an ob-
scure intimation of her "endurance in con-
formity with inherent everlasting laws," takes
possession of the soul. In such emotions there
dwells a mysterious power ; they are exciting,
yet composing ; they strengthen and quicken
the jaded intellect ; they soothe the spirit, pain-
fully commoved by the wild impulses of pas-
sion. All of earnest and of solemn that dwells
with us, is derived from the almost unconscious
sentiment of the exalted order and sublime reg-
ularity of nature ; from the perception of unity
of plan amidst eternally recurring variety of
form — for in the most exceptional forms of or-
ganization, the General is still faithfully reflect-
ed ; and from the contrast betwixt the sensu-
ous infinite and the particular finite, from which
we seek to escape. In every climate of the
globe, wherever the varying forms of animal
and vegetable life present themselves, in every
grade of intellectual eminence are these benef-
icent influences vouchsafed to man.

Another kind of enjoyment of nature, which
is likewise wholly and solely addressed to the
feelings, is that which we experience, not from
the simple presence of unbounded nature, but
from the individual characters of a country, and
for which we have to thank the peculiar physi-
ognomical attributes of the surface of our plan-
"* Impressions of this kind are more lively,

et

the vine-clad hills of Orotava, and the Hesperi-
dian gardens that line the shore. In scenes like
these, it is no longer the still creative life of
Nature, her peaceful strivings and doings, that
address us ; it is the individual character of the
landscape, a combination of the outlines of
cloud and sky, and sea and coast, sleeping in
the morning or the evening light ; it is the
beauty of the forms of the vegetable world, and
their groupings, that appeal to us ; for the im-
measurable, and even the awful in nature — all
that surpasses our powers of comprehension —
becomes a source of enjoyment in a romantic
country. Fancy brings into play her creative
powers upon all that cannot be fully attained
by the senses, and her workings take a new
direction with each varying emotion in the mind
of the observer. Deceived, we imagine that
we receive from the external world what we
ourselves bestow.

When, after a lengthened voyage, and far from
home, we for the first time set foot in a tropical
land, we are pleased to recognize in the rocks
and mountain masses, the same mineral spe-
cies we have left behind — clay slate, basaltic
amygdaloid, and the like, the universal distri-
bution of which seems to assure us, that the
old crust of the earth has been formed inde-
pendently of the external influences of exist-
ing climates. But this well-known crust is
covered with the forms of a foreign flora. Yet
here, surrounded by unwonted vegetable forms,
impressed with a sense of the overwhelming
amount of the tropical organizing force, in pres-
ence of an exotic nature in all things, the na-
tive of the northern hemisphere has revealed
to him the wonderful power of adaptation in-
herent in the human mind. We feel ourselves.

more definite, and therefore especially adapted in fact, akin to all that is organized ; and though

to particular moods of the mind. Here, it is
the magnitude of the masses, exposed amidst
some wild conflict of the elements, that arrests
us ; there, it is a picture of the immoveably
fxed that meets the eye, as in the waste and
stillness of the boundless prairies of the New
World and of the steppes of Northern Asia ; or
it is a softer and more hospitable view that at-
tracts us— a cultivated country, or the first
hermitages of man amidst the wilderness, sur-
rounded by craggy peaks, on the margin of the
leapmg brook. For it is not so much the
strength of the emotion that indicates the de-
gree of the particular enjoyment of nature, as
the determinate circle of ideas and feelings
which induce and give it endurance.

If I might here, for a moment, yield to my
own recollections of grand natural scenery, I
would revert to the ocean, under the softness
of a tropical night, with the vault of heaven
pouring down its planetary and steady, not
twinkling, starlight upon the heaving surface
of the world of waters ; or I would call to mind
the wooded valleys of the Cordilleras, where,
instinct with power, the lofty palm-trees break
through the dark canopy of foliage below, and
rising like columns, support another wood
above the woods(*) ;" or, I transport myself to
the Peake of Teneriffe, and see the cone cut
off from the earth beneath by a dense mass of
clouds, suddenly becoming visible through an
opening pierced by an upward current of air,
and the edge of the crater looking down upon

at first we may fancy that one of our native
landscapes, with its appropriate features, like
a native dialect, would present itself to us in
more attractive colours, and rejoice us more
than the foreign scene with its profusion of
vegetable life, we nevertheless soon begin to
find that we are burghers, even under the shade
of the palms of the torrid zone. In virtue of
the mysterious connection of all organic forms
(and unconsciously the feeling of the necessity
of this connection lies within us), these new
exotic forms present themselves to our fancy
as exalted and ennobled out of those which
surrounded our childhood. Blind feeling, there-
fore, and the enchainment of the phenomena
perceived by sense, in the same measure as
reason and the combining faculty, lead us to the
recognition which now penetrates every grade
of humanity, that a common bond, according
to determinate laws, and therefore eternal, em-
braces the whole of animated nature.

It is a bold undertaking to subject the magic
of the world of sense to dissection, to a separa-
tion of its elements ; for the character of gran-
deur in a landscape is especially determined by
this, that the most impressive natural phenom-
ena present themselves at once and together
to the mind — that a host of ideas and feelings
are simultaneously excited. The extent of
mastery over the feelings which is thus gained,
is most intimately connected with the unity of
the impression. But if we would explain the
power of the entire impression by the diversity

INTRODUCTION.

of the phenomena, we must descend into the
realm of determinate natural forms and active
forces, and there discriminate and distinguish.
The widest and most varied scope for investi-
gations of this kind is afforded by the land-
scapes of Southern Asia and of the New World ;
countries where stupendous mountain masses
form the bottom and boundary of the atmo-
spheric ocean, and where the same volcanic
powers which once forced up the mighty ram-
part of the Andes, through vast chasms in the
earth, sill continue to shake their work to the
terror of its inhabitants.

But natural pictures, arranged in succession
and in harmony with some leading idea, are not
calculated merely to engage the attention agree-
ably ; in their sequence they may farther be
made to compose a kind of scale of natural im-
pressions, which, in their gradually increasing
intensity, may be followed from the waste with-
out a blade of grass, to the luxuriant vegetation
of the torrid zone ; ffom the monotonous level,
to the grandest mountain chains. Were we,
giving the rein to fancy, to suppose Mount Pi-
latus piled upon Shreekhorn,(") or Schnee-
koppe set upon Mont Blanc, we should still fall
short of one of the higher peaks of the Andes,
Chimborazo, which has twice the height of
Etna ; and were we to throne the Rigi, on
Mount Athos, on Chimborazo, we should only
have an image of the highest summit of the
Himalaya, Dhawalagiri. Although the Indian
mountains, therefore, far exceed the Andes in
colossal massiness, a fact now made certain by
repeated measurements, they still present no-
thing like the variety of feature which charac-
terises the Cordilleras of South America. It is
not elevation alone that gives Nature her pow-
er of impressing the mind. The Himalaya
range lies far beyond the limits of tropical cli-
mates ; scarcely do we find a palm-tree stray-
ing into the beautiful valleys of Nepaul and Ku-
inaon.(^) Between the 28th and 34th parallels
of latitude, in the dependencies of the ancient
Paropamisus, the vegetable kingdom no longer
displays the same luxuriance of arborescent
ferns and grasses, or of large-flowered orchid-
eous plants and bananas, as she does within
the tropics, even to plateaus some thousands
of feet above the level of the sea. Under the
shadows of the cedar-like deodwara pines and
large-leaved oaks, the vegetable forms of Eu-
rope and the north of Asia are found covering
the granitic rocks that form the substrata to
the soil of the Indian mountains. They are
not the same species, indeed, but they are sim-
ilar forms : junipers, alpine birches, gentians,
parnassias, and prickly species of Ribes.(*) The
Himalaya, too, is without the varying phenom-
ena of active volcanos, which, among the
islands of the Indian Ocean, threateningly re-
mind us of the internal life of the globe. And
then, on its southern/ ridges at least, where the
moister air of Hindostan deposits its burthen,
the line of eternal snow is mostly met with at
an elevation of from eleven to twelve thousand
feet, and so sets an earlier limit to the evolu-
tion of organic life, than in the equinoctial coun-
tries of South America, where organization
extends almost two thousand six hundred feet
higher.(')
Mountainous countries near the equator have

another peculiarity, not sufficiently regarded :
they constitute the portion of the surface of our
planet, where, within the narrowest limits, the
multiplicity, or variety, of natural impressions
attains its maximum. In the deeply-cleft An-
des of New Granada and Quito, mankind have
the privilege of contemplating all the varieties
of vegetable form, and of seeing all the stars in
the firmament at once. The same glance rests
on heliconias, feathery palms of the loftiest
growth, and bambusas ; over these character-
istic forms of the tropical world, are seen oak
forests, mespilus kinds, and umbelliferous
tribes, as in our European latitudes ; and turn-
ing from earth to heaven, the eye takes in the
southern cross and Magellanic clouds, and the
northern polar star. There, the fruitful bosom
of the earth, and both hemispheres of the heav-
ens, display at once the whole stores of their
phenomena, their endless variety of forms and
features ; there are all the climates of the globe,
and the vegetable zones they severally deter-
mine, superimposed ; there are the laws of de-
clining temperature, clearly understood of the
careful observer, written in everlasting charac-
ters on the precipitous slopes of the mountains.
I but lift a corner of the veil from my recollec-
tions of tropical landscapes here, that I may
not weary this assembly with the repetition of
ideas which I have endeavoured to represent in
an illustrated work on the " Geographical Dis-
tribution of Plants(6)." What to the feelings
melts into indefiniteness and indistinctness,
like misty mountain air, is only to be compre-
hended by searching reason, when viewed in
its casual connection with general phenomena,
resolved into its constituent elements, and as
the expression of an individual natural charac-
ter. But in the circle of science, as in the
brilliant circles of descriptive poetry and land-
scape painting, the representation still gains in
clearness and objective animation, as the Indi-
vidual is more clearly indicated and defined.

If tropical countries be richer in means of
impressing the feelings, through the variety and
luxuriance of Nature, they are also (and the
point of view now taken is the most important
in the train of ideas which I am at present
pursuing) especially fitted, in the uniform reg-
ularity of their meteorological phenomena, in
their succession of organic developments, and
the sharp separation of forms effected by the
perpendicular rise of the surface, to present to
the mind the order and harmony of the heav-
ens, mirrored, as it were, in the life of the
globe. Let us pause for a moment, and con-
template this picture of harmonious regularity,
which is itself connected with numerical rela-
tions.

In the burning plains raised but little above
the level of the southern ocean, we find, in
their greatest luxuriance. Bananas, Cycadeas,
and Palms ; after them, shaded by the lofty
sides of the valleys, arborescent Ferns ; next
in succession, in full plenitude of growth, and
ceaselessly bedewed by cool misty clouds, the
Cinchonas, which yield the far-famed and pre-
cious febrifuge barks. Where lofty trees no
longer grow, we meet with Aralias, Thibaudias,
and myrtle-leaved Andromedas, associated and
blooming in company. The Alpine rose of the
Cordilleras, the Befaria, rich in resinous gum,

INTRODUCTION.

forms a purple belt about the mountains. In
the stormy region of the Paramos, all the more
lofty vegetables and large flowering herbs grad-
vally disapper. Glumaceous monocotyledo-
cous tribes now cover the surface without vari-
ety, and form unbounded meadows, looking yel-
low in the distance, where the Llama sheep is
seen feeding in solitude, and the cattle intro-
duced by Europeans roam in herds. Upon the
naked masses of trachytic rock, which here
and there rise above the surface of the turf-clad
soil, none but plants of the lowest organization
can thrive : the tribe of liverworts, which the
atmosphere, now of greatly diminished density,
and containing little carbonic acid, supports
but sparingly : Parmelias, Lecideas, and Le-
prarias with their many- coloured sporules, form
the flora of this inhospitable zone. Patches or
islets of lately fallen snow now begin to cover
the last efl!brts of vegetable life, and then,
sharply defined, the line of eternal ice begins.
Through the white, and probably hollow, bell-
shaped summits of the mountains, the subter-
ranean powers strive, but mostly in vain, to
break through. Where they have succeeded in
estabUshing a communication with the atmo-
sphere, through cauldron-shaped fiery throats or
far penetrating chasms, they rarely send forth
lava, as in the Old World, but carbonic acid,
hydrosulphurets, and hot watery vapour in
abundance.

So magnificent a spectacle, in its first assault
upon the rude natural feelings, could excite
nothing but wonder and dull amazement in the
mind of natives of the tropical world. The in-
timate connection of grand periodically recur-
ring phenomena, and the simple laws according
to which these phenomena are grouped zone-
wise, present themselves there, above all other
places, with signal clearness to the senses of
mankind ; but from causes which, in many por-
tions of this highly favoured quarter of the
earth, oppose the local development of high
civilization, all the advantages of this more fa-
cile study of these laws have remained with-
out effect — so far, at least, as historical data en-
able us to conclude. The profound researches
of recent times have made it more than doubt-
ful that the peculiar seat of the Indian civiliza-
tion— one of the fairest flowers in the history
of humanity, the south-eastern spread of which
has been so ably investigated by William von
Humboldt(0 — was within the limits of the trop-
ics. Airyana Baedjo, the ancient Zend coun-
try, lay to the north-west of the upper Indus ;
and after the religious disunion or secession of
the Iranians from the Brahminical institutes,
and their separation from the Hindoos, the ori-
ginal common language acquired its distin-
guishing features, and the social institutions
gained their peculiar characters in Magadha(^),
or Madhya Desa, between the little Windhya
and the Himalaya chain.

A clear insight into the operations of the
physical agencies was first, although, indeed,
at a much later period, acquired by the races
that people the temperate zone of our northern
hemisphere, and this, in spite of all the obsta-
cles which, under higher latitudes, complicate
the phenomena of the atmosphere, and render
difficult the discovery of general laws in the
climatic distribution of organic beings. From

hence has a knowledge of the character of trop-
ical countries, and of countries situated near
the tropics, been brought by larger movements
of masses of mankind, or by individual foreign
settlers — a transplantation of scientific culture
which has had a like beneficial influence on the
intellectual existence and industrial prosperity
both of colonies and parent states. And here
we touch the point at which, in the commerce
betwee^n mind and the world of sense, another
form of enjoyment is associated to that which
depends on excitement of the feehngs — an en-
joyment of nature which springs from ideas ;
the point at which, in the war of the conflicting
elements, the orderly, the legitimate, is not
merely surmised or suspected, but is positively
known by force of reason : the point at which
man, as the immortal poet has it —

Amidst fleeting phenomena, seeks the stable pole. (9)

To follow this variety of enjoyment, spring-
ing from ideas, to its source, we have only to
cast our eye back upon the rise and progress
of the history of the philosophy of nature ; in
other words, of the ancient doctrine of Cosmos.

An indefinite dread sense of the unity of the
powers of nature, of the mysterious bond which
connects the sensuous with the super-sensuous,
is common even among savage communities ;
my own travels have satisfied me that this is so.
The world which is revealed to man through the
senses, blends, often without his consciousness,
with the world which, in obedience to his inter-
nal promptings, he creates in the guise of a
realm of wonders in his own interior. The
latter, however, is nothing like a true reflection
of the former -, for however impotent the Ex-
ternal be to dissever itself from the Internal,
still creative fancy, and the disposition to rep-
resent in concrete shapes the significant in phe-
nomena, proceed incessantly in their workings,
even among the rudest nations. That which
presents itself to single more gifted individuals
as the rudiments of a natural philosophy, as an
induction under the guidance of reason, ac-
quires existence as the product of instinctive
susceptibilities among whole tribes of men. In
this way, out of the depth and activity of blind
feeling, is also eliminated the first impulse to ad-
oration, the sanctification of the preserving as
of the destroying powers of nature ; and, if
man, in passing through the different phases
of his progress, now feels himself less fettered
to the earth, and rising by degrees to mental
freedom, he can be satisfied no longer with a
mere indefinite feeling, an obscure suspicion of
the unity of the natural forces. The faculty of
thought, with its attributes of analysis and ar-
rangement, now asserts its rights, and growing
in the same measure as the human kind im-
proves, in presence of the plenitude of life that
flows throughout creation, the eager desire to
penetrate more deeply into the causal connec-
tion of phenomena is experienced.

It is extremely difficult to obtain speedy and,
at the same time, certain satisfaction to such a
desire. From imperfect observations, and still
more imperfect inductions, erroneous views ot
the character of the natural forces arise ; views
which, embodied and fixed in significant words
and phrases, distribute themselves, a common
inheritance of fancy, through all classes of a
nation. By the side of the scientific system of

introduction:

nature, another is then seen growing with an
equal growtli — a system of unproven, and, in
part, entirely mistaken empirical knowledge.
Embracing but few particulars, this kind of
empiricism is the more presuming, because of
its utter ignorance of the facts by which it is
assailed. Shut up within itself, it is unchan-
ging in its axioms, and arrogant, like every thing
else that is restricted ; whilst enlightened nat-
ural science, inquiring, and therefore doubting,
goes on separating the firmly established from
the merely probable, and perfects itself daily
through the extension and correction of its
views.

The crude heap of physical dogmas which
one age transmits to and forces upon another,
is not merely injurious because it cherishes in-
dividual errors, because it obstinately presents
indifferently observed facts for acceptance ; it
does more than this, it opposes every thing like
grand or comprehensive views of the fabric of
the universe. Instead of investigating the me-
dium point about which, despite the apparent
unfettered aspect of nature, all phenomena os-
cillate within narrow limits, it takes cognizance
of the exceptions only to the law ; it seeks for
other wonders in phenomena and forms than
those of regulated and progressive develop-
ment. It is ever disposed to presume the train
of natural sequence interrupted, to overlook in
the present all analogy with the past, and, tri-
fling with the subject, to discover the cause of
some fancied disturbance now in the depths of
the vault of heaven, now in the interior of the
globe we inhabit. It leads away from that com-
parative geognosy which Ritter's great and
masterly work has shown can only acquire any
thing like completeness when the whole mass
of facts, which have been collected in all the
climates of the earth, comprehended at a glance,
stands marshalled at the disposal of the combi-
ning intellect.

It is one of the objects of these discourses
upon nature, to correct a portion of the errors
which have sprung from rude and imperfect
empiricism, and continue to live on among the
upper classes of society, associated frequently
with distinguished literary tastes and acquire-
ments, and thereby to increase the relish for
nature by giving a clearer, a deeper, insight into
her constitution. The want of such an enno-
bled relish for nature is generally felt ; for a
peculiar character of the age we live in, is pro-
claimed in the tendency among all the educated
classes to enhance the pleasures of existence
by adding to the store of ideas. The lively in-
terest which is taken in these prelections bears
witness to the prevalence of such a disposition.

I cannot, therefore, yield any place in my
mind to the solicitude to which either a certain
narrowness of understanding, or a kind of sen-
timental dulness, appears to lead — the solici-
tude, namely, that nature loses aught of her
magic, of her charms in respect of mysterious-
ness and grandeur, by inquiries into the inti-
mate constitution of her forces. The forces of
nature, indeed, only operate magically, in the
legitimate sense of the word, shrouded, as it
were, in the gloom of some mysterious power,
when their workings lie beyond the bounda-
ries of generally ascertained natural conditions.
The observer who determines the diameters of

the planets with a heliometer, or a prism of
double refracting spar(^°), who measures the
meridian altitudes of the same star for a series
of years, who discovers telescopic comets
amidst thickly aggregated nebulous spots, does
not, probably, feel his fancy more excited than
the descriptive botanist, whilst he is counting
the divisions in the calyx and corolla of a flow-
er, or is ascertaining, in the structure of a moss,
the state of distinctness or coalescence of the
teeth that surround the seed capsule ; but meas-
urements of angles, and the development of
numerical relations, the careful observation of
the Individual, prepares the mind for the loftier
knowledge of nature as a whole, and leads to
the discovery of the laws that rule the universe.
To the natural philosopher, who, like Young,
and Arago, and Fresnel, measures the undula-
tions of unequal length, the interferences of
which strengthen or weaken the ray of light ;
to the astronomer, who, by the space-piercing
power of his telescope, studies the satellites of
Uranus on the outermost verge of our system,
or, like Herschel, South, and Struve, detects
glimmering points of brighter light in the col-
oured double stars ; to the initiated eye of the
botanist, who perceives the circular movements
of the sap-globules so conspicuous in the Charas,
in almost all vegetable cells, and who finds unity
of formation, in other words, enchainment of
forms, in species and natural families — these
cultivated intellects surely look into the depths
of heaven, as they survey the flower-clad sur-
face of the earth, with a grander eye, than the
observer whose intellectual vision is not yet
sharpened by any apprehension of the enchain-
ment of phenomena. We cannot, therefore, as-
sent to the proposition of the eloquent Burke,
when he says, that " out of the uncertainty of
the nature of things alone, do admiration and
the feeling of sublimity arise."

Whilst vulgar sense conceives the stars in-
laid in a crystalline vault, the astronomer actu-
ally extends the bounds of space ; for if he cir-
cumscribes the cluster of stars, of which our
sun is one, it is only that he may show others
and others, a countless multitude of groups of
suns, the infinite depths of space, till vision fails,
still studded with astral systems like our own.
The feeling of the sublime, in so far as it seems
to spring from the simple contemplation of in-
finite space, is closely allied to that rapt mood
of the mind which, in the realm of the spiritual,
in abstract converse with our own conscious-
ness, arises from the meditation of the endless
and the free. Upon this affinity, this relation-
ship of sensuous impressions, depends the ma-
gic, the feeling of infinitude, which we experi-
ence when we are gazing over the shoreless
ocean, surrounding some isolated mountain
peak, or are penetrating the depths of heaven-
ly space with the telescope, and resolving neb-
ulous specks into their constituent stars ; no-
thing impresses the cultivated imagination more
powerfully than spectacles like these.

One-sided treatment of the physical sciences,
endless accumulation of the raw material, might
indeed appear to countenance the now almost
superannuated objection, that scientific knowl-
edge must of necessity chill the feelings, quench
the creative light of fancy, and so interfere with
the enjoyment of nature. But he who counte-

INTRODUCTION.

nances this idea, in the stirring times in which
we live, very certainly misunderstands the joys
of that higher intelligence which is the appa-
nage of the general progress of human society —
of that tendency of the mind which resolves
multiplicity into unity, and loves especially to
dwell with the General and the Exalted. To
taste, to enjoy this Exalted, it is imperative
that the individualities which have been the
prize of the carefully cultivated field of special
natural forms and natural phenomena be care-
fully kept in the background ; he who has him-
self most clearly seen their importance, and
whom they have most safely led to loftier
views, must more especially hold them in re-
serve.

To the groundless fears for the loss of an
unfettered enjoyment of nature, under the in-
fluence of reflective surveys, or scientific scru-
tinies of her domains, may be associated those
which are derived from alarm lest a due meas-
ure of this knowledge, or an adequate concep-
tion of its bearings, prove unattainable to the
mass of mankind. In the wonderful tissues of
organized beings, in the eternal tendencies and
workings of the living powers, each new and
deeper inquiry seems but to lead to the en-
trance into a new labyrinth. But this very
multiplicity of untrodden and intricate paths
excites a kind of joyful amazement on each
successive grade of science. Each natural law
which reveals itself to the observer leads to
the inference of one yet higher and unknown ;
for Nature, as Carus well says(^'), and as the
word itself was understood by the ancient
Greeks and Romans, " is the Ever-becoming,
the Ever-engaged in fashioning and evolving."
The circle of organic types extends the wider
the more the earth is searched over, in travels
by land and voyages by sea ; the more living
organic forms are compared with the remains
of those that are extinct, the more the micro-
scope is improved, and adds to the empire of
the eye. In the multiplicity and changes of
organic forms, in consonance with climatic in-
fluences, the prime mystery of all formation is
incessantly reproduced ; it is the problem of
metamorphosis, so happily developed by Go-
ethe, upon the grandest scale, and proclaims
the necessity for an ideal reference of organic
forms at large to certain elementary types.
With an extension of knowledge, the feeling
o* the immeasurableness of the life of nature
IS still increased, and we perceive that, neither
in the solid crust of the globe, nor in the aerial
covering that invests the solid, neither in the
depths of the ocean, nor in the depths of heav-
en, will the bold scientific conqueror(") lack
scope for his inquiries for thousands of years
to come.

General views of the Fashioned, be it matter
aggregated into the farthest stars of heaven,
be it the phenomena of earthly things at hand,
are not merely more attractive and elevating
than the special studies which embrace partic-
ular portions of natural science ; they further
recommend themselves peculiarly to those who
have little leisure to bestow on occupation of
the latter kind. The descriptive natural scien-
ces are mostly adapted to particular circum-
stances : they are not equally attractive at ev-
ery season of the year, in every country, or in

every district we inhabit. The immediate in-
spection of natural objects, which they require,
we must often forego, either for long years, or
always in these northern latitudes ; and if our
attention be limited to a determinate class of
objects, the most graphic accounts of the trav-
elling naturalist afford us little pleasure if the
particular matters, which have been the spe-
cial subjects of our studies, chance to be pass-
ed over without notice.

As universal history, when it succeeds in ex-
posing the true causal connection of events,
solves many enigmas in the fate of nations, and
explains the varying phases of their intellectu-
al progress — why it was now impeded, now ac-
celerated— so must a physical history of crea-
tion, happily conceived, and executed with a
due knowledge of the state of discovery, re-
move a portion of the contradictions which the
warring forces of nature present, at first sight,
in their aggregate operations. General views
raise our conceptions of the dignity and gran-
deur of nature ; and have a peculiarly enlighten-
ing and composing influence on the spirit ; for
they strive simultaneously to adjust the con-
tentions of the elements by the discovery of
universal laws, laws that reign in the most del-
icate textures which meet us on earth, no less
than in the Archipelagos of thickly clustered
nebulae which we see in heaven, and even in
the awful depths of space — those wastes with-
out a world. General views accustom us to
regard each organic form as a portion of a
whole ; to see in the plant and in the animal
less the individual or dissevered kind, than the
natural form, inseparably linked with the ag-
gregate of organic forms. General views give
an irresistible charm to the assurance we have
from the late voyages of discovery undertaken
towards either pole, and sent from the stations
now fixed under almost every parallel of lati-
tude, of the almost simultaneous occurrence of
magnetic disturbances or storms, and which
furnish us with a ready means of divining the
connection in which the results of later obser-
vation stand to phenomena recorded as having
occurred in bygone times ; general views en-
large our spiritual existence, and bring us, even
if we live in solitude and seclusion, into com-
munion with the whole circle of life and activ-
ity—with the earth, with the universe.

Who — to select a particular instance from
the realms of space — who, that has paid any
attention to scientific events in the course of
the last few years, can perceive, without a gen-
eral knowledge of the ordinary orbits of com-
ets, how pregnant with results is Encke's dis-
covery, that a comet, which, in its elliptical or-
bit, never leaves our planetary system, reveals
the existence of a fluid controlling its centrifu-
gal force 1 With the recent spread of a kind
of half-education, which attracts scientific con-
clusions into the circle of social amusement
and conversation, but so commonly distorts
them, we have seen the old solicitude revived
about a collision between the heavenly bodies,
threatening danger or destruction to all, and
cosmic influences, in an altered and therefore
more deceitful guise, quoted to account for pre-
sumed deteriorations of climates, and the like.
Clear conceptions of nature, though they may
not be more than historical, preserve us from

INTRODUCTION.

the presumptions of dogmatizing fancy. They
assure us that Encke's comet, which completes
its revolution in 1200 days, by reason of the
form and position •f its orbit, must ever be
harmless to the inhabitants of the earth — as
harmless as Halley's comet, the great comet
of 1.759 and 1835, with its period of 76 years ;
but that another comet, of shorter period, Bie-
la's, to wit, with its course of six years, actu-
ally crosses the orbit of the earth, though it
can only approach us nea.ly when its perihelion
falls at the time of our winter solstice.

The quantity of caloric which one of the plan-
ets receives, and the distribution of which de-
termines the grand meteorological processes
of the atmosphere, is modified by the light-
evolving power of the sun — the property of its
surface, and the relative position of the sun
and the planet ; but the cyclic changes which
the form of the earth's orbit, and the obliquity
of the ecliptic, undergo, in conformity with the
general laws of gravitation, are so slow, and
confined within such narrow limits, that their
influence will scarcely be perceptible to such
instruments as we now possess for measuring
temperature in the course of several thousand
years. Cosmic causes of diminished tempera-
ture, of lessened fall of rain, and of epidemic
diseases, which were much canvassed in the
middle ages, and of which mention has again
been lately made, are consequently seen to be
entirely beyond the pale of actual experience.

If I would quote other instances from phys-
ical astronomy, which could excite no interest
without a general knowledge of what has been
already observed, I would refer to the numer-
ous instances of differently coloured double
stars which move in ellipses round one anoth-
er, or rather around their common centre of
gravity ; to the periodical rarity of spots in the
sun ; to the regular appearance of innumerable
falling stars, which have now been the subject
of observation for so many years, and which
are in all probability planetary in their nature,
circulating round the sun, and crossing the
earth's orbit, in their course on the 12th or
13th of November, and also, according to later
observation, on the 10th or 11th of August.

In the same way, general views of Cosmos
will alone enable us to perceive the connection
betwixt the theory of the pendulum swinging
in air, and the internal density — I might say,
the degree of congelation or solidification — of
our globe, a theory happily completed by the
acuteness of Bessel ; betwixt the production of
crystalline rocks in stratified streams of lava
upon the acclivities of still active volcanoes,
and the endogenous granitic, porphyritic, and
serpentine rocky masses, which, forced up from
the interior of the earth, have burst through the
floetz formations, and produced various effects
upon them— hardening or silicifying them, con-
verting them into dolomite, producing drusy
cavities, filled with crystals, &c. ; betwixt the
elevation of islands and conical mountains,
through elastic forces, and the uplifting of
mountain chains and entire continents — a con-
nection which has been acknowledged by the
greatest geologist of our age, Leopold von Buch,
and illustrated by a series of admirable observa-
tions. Such upheavings of granular mountain
masses and floetz strata, as have even lately

been witnessed over a vast extent of the coast
of Chili, in connection with an earthquake,
show us how possible it is that the marine
shells, which Bonpland and I discovered on the
slopes of the Andes, at an elevation of 14,000
feet above the level of the sea, were brought
thither, raised from the bed of the ocean by
volcanic forces, not by any general flood that
overspread the surface as it now presents itself
to us.

By Plutonism, or Vulcanism, taking either
word in its most general sense, and using it not
only with reference to the earth, but also to its
satellite, the moon, I mean the reaction which
the interior of a planet exerts upon its crust.
He who is unacquainted with the observations
that have been made on the gradual rise of tem-
perature, as the crust of the earth is penetrated
more deeply (observations which have led dis-
tinguished naturalists to conclude that at the
depth of five geographical miles below the sur-
face, a temperature adequate to keep granite in
a state of fusion prevails"), is not prepared to
appreciate many recent observations on the
simultaneousness of the eruptions of volcanoes,
separated by vast extents of country, on the
limits of the circles within which earthquakes
are likely to be felt, on the permanence of the
temperature of hot mineral springs, and on the
difference of temperature of the water in Ar-
tesian wells of different depths. And yet this
knowledge of the internal temperature of the
earth throws a feeble light upon the primary
history of our planet. It proclaims the possi-
bility at a former epoch of the general diffusion
of a tropical climate over the surface of the
globe, as a consequence of heat inherent, arid
of clefts pouring forth heat, in the lately con-
creted and oxidated crust of the earth. It re-
minds us of a state of things in which the tem-
perature of the atmosphere may have been
more intimately connected with the reaction of
the interior upon the exterior, than with the
position of the axis of revolution of our planet
to the great central mass of our system, the
sun.

Numerous productions of the tropics are now
dug up by eager geologists from their tombs in
the temperate and cooler regions of the earth :
coniferous vegetables, trunks of palm trees,
erect as when they grew, arborescent ferns,
goniatites, and fishes with rhomboidal pearly
scales, in the old coal formations(**) ; skeletons
of colossal crocodiles, long-necked plesiosauri-
ans, the scales of planulites, and the stems of
cicadeae, in the Jura limestone ; polythalamians
and bryozoa in chalk, in several instances iden-
tical with species still existing in our seas ;
vast agglomerations of infusory animalcules, as
brought to light by Ehrenberg's all-animating
microscope, in beds of tripoli, semicpal and si-
liceous sinter (1) (Kieselguhr) ; bones of hyenas,
lions, and elephantine pachydermatous animals,
lying exposed in caverns, or covered merely
with a layer of sand or mud. With a compe-
tent knowledge of other natural phenomena,
these productions do not remain objects of
mere idle curiosity and wonder ; they become
more worthily the occasion of much varied and
interesting reflection.

In the multiplicity of objects which I have
thus cursorily enumerated, the question pre-

10

INTRODUCTION.

sents itself: whether general views of nature
can be brought to anything like precision with-
out deep and earnest study of the several de-
partments of natural science — natural history,
natural philosophy, and physical astronomy 1
Here it is proper to distinguish carefully be-
twixt the teacher, who makes selections and
delivers an account of results, and the pupil,
who receives the account as something pre-
sented to him not investigated for himself. For
the former, the most intimate knowledge of
specialities is indispensably necessary ; he must
have long familiarised his mind with the several
sciences, he must himself have taken the
length and the breadth of things, observed and
made experiments, before he can, with any
confidence or, propriety, venture on a picture of
nature as a whole. The entire bearings of the
problems whose investigation lends such attrac-
tions to the physical history of the world are
perhaps scarcely to be comprehended in all
their clearness where special preliminary knowl-
edge is wanting ; although, without it, the
greater number of the propositions can still be
satisfactorily discussed. If the great picture
of nature be not presented with its outlines
equally clear and sharp in every part, it will
still be found sufficiently true and attractive to
enrich the mind with ideas, and to arouse and
fructify the imagination.

It has been made matter of reproach — and
perhaps with some propriety — that the scien-
tific works in our language do not sufficiently
separate the General from the Particular — the
review of actually established facts from the
narrative of the means by which the results
have been obtained. This imputation has led
the greatest poet of our age(") humorously to
say, that " the Germans possess the faculty of
making the sciences inaccessible." But the
scaffisld left standing, we are hindered from ob-
taining a clear view of the building. And who
will doubt, that the physical law in the distri-
bution of the continental masses, which assume
a pyramidal shape towards the south, whilst
towards the north they spread out into vast
bases — a law by which the division of climates,
theprevalenceofparticular winds, the extension
of tropical vegetable forms into the temperate
northern zones, is explained in the most satis-
factory manner — can be understood without
reference to the trigonometrical surveys, and
the astronomical determinations of precise ge-
ographical positions, by which the dimensions
of the pyramids referred to have been ascer-
tained 1 In the same way, we learn from phys-
ical geography, that the equatorial axis of our
planet is greater than the polar axis by a cer-
tain number of miles, that the southern hemi-
sphere is not flattened in a greater degree than
the northern hemisphere, &c., without its be-
ing necessary to narrate at length how, by
measurements of degrees of the meridian, and
experiments with the pendulum, the figure of
the earth has been finally determined to be that
of an irregular spheroid of revolution in an el-
lipsis ; and how this figure is reflected in the
motions of our satellite, the moon.

Our neighbours on the other side of the Rhine
possess an immortal work, Laplace's " Sys-
teme du Monde," in which the results of the
most profound mathematico-astronoiuical in-

vestigations of the phenomena of past centunes
are luminously presented, freed from the indi-
vidualities of the demonstration. The struc-
ture of the heavens there jjresents itself as the
simple solution of a great problem in mechan-
ics. Yet no one has ventured to charge the
" Exposition du Systeme du Monde" with want
of depth, because of its form. The separation
of the Dissimilar in views, of the General from
the Special, is not merely useful in facilitating
the acquisition of knowledge ; it farther gives
an elevated and earnest character to the treat-
nient of natural science. As from a higher sta-
tion we overlook larger masses at once, so are
we pleased mentally to grasp what threatens
to escape the powers of our senses. If the
successful cultivation of every branch of natu-
ral science in recent times, appear especially
calculated to extend the study of particular de-
partnients — the chemical, the physical, the phys-
iological, &c. — the progress made in each will
nevertheless contribute in an eminent degree
to abridge and render 'easy the way to the at-
tainment of general principles.

The more deeply we penetrate into the es-
sence of the natural forces, the more do we
perceive the connection of phenomena, which,
severally and superficially regarded, seemed
long to resist every attempt at co-ordination
and arrangement ; the more do we see simpli-
city and brevity possible.

It is a certain indication of the extent and
value of the discoveries which were to be look-
ed for in any science, when the facts present
themselves as still unconnected, almost, as it
seems, without any thing like mutual reference,
and when several of them, the fruit of the same
degree of careful observation, even appear con-
tradictory or subversive. We stand at thiij
time in a state of lively expectation in regard
to meteorology, to some of the departments of
optics, and especially, since Melloni and Fara-
day came upon the stage, to the radiation of
heat and electro-magnetism. The field of brill-
iant discovery here, has certainly not yet been
exhausted, although a very remarkable con-
nection of electrical, magnetical, and chemical
phenomena has undoubtedly been developed in
the voltaic pile. And who shall guarantee us
that the entire number of the vital forces effi-
cient in the universe has been fathomed 1

In my mode of considering the scientific treat-
ment of a general description of creation, I
make no question of that unity which is arrived
at by induction from a few fundamental princi-
ples supplied by reason. What I entitle a Phys-
ical HisTOEY OF Creation — in other words, a
comparative natural history of the earth and
heavens — consequently, makes no pretensions
to the rank of a rational Science of Nature ;
it is a simple consideration of the phenomena
that are known empirically, or by experience,
as a natural whole. With the entirely object-
ive constitution of my mind, it is under such
restrictions alone that the history of creation
fulls within the scope of the inquiries which
have exclusively occupied me in the long course
of my scientific life. I do not venture upon a
field that is strange to me, and that will prob-
ably be cultivated to better purpose by another.
The unity attainable in such a history of crea-
tion as I propose to exhibit, is no more thaa

INTRODUCTION.

11

that which historical representations in gener-
al can hope to achieve. Details, whether as to
the form or arrangement of natural things, no
more than in reference to the struggles of man
with the elements, or the wars of one nation
against another — all, in short, that falls within
the sphere of mutability and true accident — can-
not be derived or built up from a priori concep-
tions. The natural history of the earth, and
universal history, consequently, stand on the
same grade of the empirical ladder ; but a lu-
minous treatment of either, a rational arrange-
ment of natural phenomena and of historical
incidents, impresses us deeply with a belief in
an old inherent necessity, which rules all the
operations both of the spiritual and material
forces within circles eternally reproduced and
only periodically contracted or enlarged. This
necessity, indeed, is the very essence of nature ;
it is nature herself, in the two spheres of her
being — the material and the spiritual — and it
leads to clearness and simplicity of view, to the
discovery of laws which, in experimental sci-
ence, present themselves as the ultimate term
in human inquiries.

The study of every new science, especially
of one which embraces the infinite field of cre-
ation, the universe at large, may be compared
to a journey into a foreign country. Before
undertaking such an expedition in company,
we inquire as to its feasibility ; we measure our
own powers of endurance, and we look with a
suspicious eye at the powers of our intended
companions, with the perchance unjust anxie-
ty lest they prove impediments in the way.
But the times in which we live diminish the
difficulties of the enterprise, and my confidence
in ultimate success is based on the brilliant po-
sition now occupied by natural science itself,
whose increasing stores may now be said to
add less to the amount than to the enchain-
ment of observation. The general results,
which so powerfully interest every cultivated
mind, have been wonderfully augmented since
the end of the eighteenth century. Facts now
stand less insulated ; numerous gaps between
different orders of beings and phenomena have
been filled up ; points which had remained in-
explicable to the inquiring spirit at home, with-
in the narrower circle of experience accessible
to it, are frequently made clear by journeys un-
dertaken into the remotest regions of the earth.
Vegetable and animal forms that long appeared
isolated, now appear connected by intermedi-
ate links or transition forms. A general con-
catenation, not in simple linear directions only,
but in reticulate or more intricate modes, ac-
cording to the higher development or the ar-
rest of certain organs, according to relative pre-
ponderance in the several parts or systems, now
presents itself to the mind of the enlightened
naturalist. Appearances of stratification in tra-
chytic syenite or porphyry, in green stone and
serpentine, which are doubtful in Hungary, so
rich in gold and silver, in the platina districts
of the Ural chain, or deeper into Asia, in the
south-western Altai, are unexpectedly cleared
up by geological observations in the lofty pla-
teaus of Mexico and Antioquia, and in the val-
leys of Choco. The materials which universal
geography employs are not indiscriminately ac-
cumulated. In the present times, in virtue of

the tendency which their individual character
impresses upon them, it is admitted that new
facts are only pregnant with future good, when
the traveller is familiar with the actual state
and requirements of the science whose bound-
ary he pretends to widen ; when ideas, in oth-
er words, insight into the spirit of nature, guide
the taste for observation and collection.

Through this direction of the study of nature,
through the happy, but, at the same time, often
too readily satisfied taste for general results,
can a very considerable portion of natural sci-
ence be made the common property of cultiva-
ted humanity, and this with a full sense of the
import and form, of the grandeur and worth of
the subject, altogether different from that pop-
ular science which was held sufficient for the
world at large up to the end of the last centu-
ry. Let him, therefore, whom circumstances
permit to escape from time to time from the
narrow circle of his every-day occupations, la-
ment that he has " remained so long a stranger
to nature, unconscious of her charms," and
learn, that in the contemplation of her grandeur
and freedom, there dwells the purest delight
which exalted intelligence can obtain for man.
The study of general natural science, indeed,
awakens organs in our interior that have long
slumbered. We enter upon a new and more
intimate intercourse with the external world,
and are brought to feel a larger sympathy with
that which proclaims at once the industrial
progress, and the intellectual improvement of
mankind.

The clearer the insight we obtain into the
connection of phenomena, the more readily do
we emancipate ourselves from the error of
believing that every department of natural
knowledge is not equally important in the cul-
ture and welfare of mankind, whether it be that
department which measures and describes, or
chemical inquiries, or the investigation of the
generally diffused physical forces of matter. In
the observation of a phenomenon which seems
at first to stand isolated and alone, there fre-
quently lies the germ of a great discovery.
When Galvani stimulated the nerves of sensa-
tion by the contact of two dissimilar metals, his
most intimate friends and contemporaries could
never have expected that the voltaic pile, with
its electricity of contaction, would one day
show us a brilliant metal in the alkalis, silvery
in its appearance, readily inflammable, and so
light as to float upon the surface of water ; that
the same arrangement would by and by become
the most powerful instrument in analytical
chemistry, and prove at once a thermoscope
and a magnet. When Huyghens began to in
vestigate the optical properties of double re
fracting spar, no one imagined that the phe
nomena of coloured polarization would lead om
of the singularly clear-sighted natural philoso
phers of our day('*) to discover in the fragmen
of a mineral a means of knowing whether thi
light of the sun proceeded from a solid mass o*
from a gaseous canopy ; whether comets havo
the power of emitting light in themselves, or
merely reflect the light they receive from other
sources.

A like respect for every department of the
study of nature is, however, especially neces-
sary in the present times, when the material

M

INTRODUCTION.

wealth and the increasing welfare of the na-
tions is so closely connected with a more dili-
gent use of natural productions and natural
forces. The most superficial glance at the
condition of Europe in these days, assures us
that with the struggle against serious odds, any
relaxation of effort would be followed, first by
diminution, and then by annihilation of national
prosperity ; for in the destiny of nations it is as
in nature, in which, as Goethe (") says, finely,
" there is neither rest nor pause, but ever move-
ment andv evolution, a curse still cleaving to
standing still." Nothing but serious occupa-
tion with chemical, mathematical, and natural
studies, will defend any state from evils assail-
ing it on this side. Man can produce no effect
upon nature, can appropriate none of her pow-
ers, if he be not conversant with her laws, with
general relations according to measure and
number. And here, too, lies the power of pop-
ular intelligence. It rises and falls with this.
Science and information are the joy and the
justification of mankind ; they are portions of
the wealth of nations, sometimes a substitute
for material wealth, which nature has in many
cases distributed with so partial a hand. Those
nations which have remained behind in gen-
eral manufacturing activity, in the practical
application of the mechanical arts, and techni-
cal chemistry, in the transmission, growth, or
manufacture of raw materials, nations among
whom respect for such activity does not per-
vade all classes, must inevitably fall from any
prosperity they may have attained ; and this by
so much the more certainly and speedily, as
neighbouring states, instinct with powers of
youthful renovation, in which science and the
arts of industry co-operate or lend each other
assistance mutually, are seen pressing forward
in the race.

The taste for manufacturing industry, and
for those portions of natural science which bear
upon it more immediately — a characteristic of
the present 'age — can in nowise be prejudicial
either as regards philosophy, antiquities, or his-
tory, nor quench the all-animating flame of fan-
cy, in the direction of the liberal arts. Where
all the offshoots of civilization are permitted to
expand in vigour, under the protection of wise
laws and free institutions, no effort of mind in
any one direction will be found to interfere
with its aspirations in another quarter. Each
presents its own peculiar fruit to the common-
wealth : one, the means of maintenance and
comfort to the citizen, another, the product of
creative fancy, which, more durable than ma-
terial wealth, transmits the name and fame of
the community to the latest posterity. The
Spartiates, despite the austerity of the Doric
mind, prayed " the Gods to vouchsafe them the
beautiful associated with the good."(**)

As in those higher circles of ideas and feel-
ings—in the study of history, of philosophy, and
of oratory — so in all the departments of natural
science, the first and highest aim of intellectu-
al activity is one that is internal ; namely, the
discovery of natural laws, the establishment of
co-ordinate members in the images, the per-
ception of necessary connection between all
the changes that happen in the universe. So
much of this science as flaws over, and min-
gles with the industrial life of communities, el-

evating manufacturing industry, does so in vir-
tue of the happy connection in human things,
by which the true, the exalted, and the beauti-
ful, mix unintentionally, as it seems, but cer-
tainly, with the useful, and co-operate with it
in bringing about results. The improvement
of agriculture by the hands of freemen, and on
lands of moderate extent ; the flourishing con-
dition of manufactures, emancipated from op-
pressive restrictions ; the extension of com-
mercial relations, and the unimpeded progiess
of mankind in mental development as well as in
their social institutions, are all inseparably con-
nected, and severally and powerfully advance
each other. The impressive picture of the late
history of the world forces this faith upon the
minds even of those that most eagerly oppose it.

Such an influence of natural science upon the
welfare of the nations, and on the present con-
dition of Europe, can receive nothing more
than a passing allusion in this place. The
course we have to complete is so vast in itself,
that it would not become me to depart from the
main object we have in view, namely, the sur-
vey OF NATURE AS A WHOLE, and intentionally
to widen the field of our inquiries. Accustom-
ed to wanderings in distant lands, I have, per-
haps, without this, indicated the path to my
fellow-travellers, as more distinctly traced and
more attractive than they will find it in fact.
This is ever the way with those who take
pleasure in guiding others to the tops of mount-
ains : they praise the view, though perchance
large tracts of the country lie hidden in mist.
They know that even in this concealment there
dwells a certain mysterious charm ; that the
misty horizon calls up the image of the sensu-
ous infinite in the mind, a picture which, as I
have already observed, is reflected in grave and
grand tints in the mind and affections. From
the lofty stand, too, from which we propose to
make our general survey of nature on the basis
of science, all that is requisite cannot be com-
manded. In natural science, much yet lies but
ill defined, and much — and shall I not gladly
own to this in entering on a field so vast 1 —
will appear indefinite and incomplete only be-
cause every thing like embarrassment becomes
doubly detrimental to the speaker, who feels
himself indifferently at ease in his subject, when
separated from its individualities.

The purpose of this Introduction was not to
present a picture of the importance of natural
science, a thing universally admitted ; it was
rather to show how, without detriment to the
deepest study of the several special depart-
ments of natural science, a higher position for
physical scientific inquiry may be won, from
which all the forms and powers of things shall
be seen to reveal themselves, in the guise of a
natural whole, actuated by intrinsic aptitudes.
Nature is no dead aggregate ; she is, " to the
inspired inquirer," (as Schelling grandly ex-
presses himself, in his admirable Discourse on
the Fine Arts), " the holy, the eternally crea-
tive prime mover of the universe, engendering
and evolving all things out of her pregnant
self" The hitherto imperfectly seizoi idea of

a PHYSICAL HISTORY OF THE EARTH CXpaudS, UU-

der more enlarged views and the comprehen-
sion of all created things in earth and heaven,
into the idea of a physical history of thk

INTRODUCTION.

13

tNivKRsE. The latter of these titles is fashion-
ed from the former. But it is the history of
the universe, or the doctrine of Cosmos, as I
conceive it ; by no means an encyclopaedic ex-
position of the most general and important re-
sults derived from particular natural historical,
natural philosophical, and astronomical books.
Such results will only be introduced incidental-
ly into my description, and be used as mate-
rials only in so far as they illustrate the con-
nection and co-operation of the forces of the
universe, the production and limitation of nat-
ural phenomena. The study of the distribu-
tion of organic types according to soil and cli-
mate, the geography of plants and animals, is
as dissimilar from descriptive botany and zo-
ology, as geological knowledge of the crust of
the Earth is different from oryctognosy. A
physical history of the universe, consequently,
must not be confounded with an encyclopaedia
of the natural sciences. In our survey of the
Universe, the Individual will only be regarded
in its relations to the General, and the higher
the point of outlook now indicated is assumed,
the more will this survey be made susceptible
of especial treatment, and of interesting dis-
cussion.

Thought and Language, however, stand in
most intimate and old relationship to one an-
other. When speech adds grace and clearness
to ideas, when its picturesqueness of derivation
and organic structure favour our efforts sharp-
ly to define natural phenomena as a whole, it
scarcely fails at the same time, and almost un-
consciously to us, to infuse its animating pow-
er into the fulness of thought itself The word
is, therefore, more than the mere sign and form,
and its mysterious influence still reveals itself
most strikingly where it springs among free-
minded communities, and attains its growth
upon native soils. Proud of our fatherland,
whose intellectual unity is the prop and stay of
every manifestation of mental power, we turn
our eyes with joy upon this privilege of our na-
tive country. Highly-favoured, indeed, may
we call him who draws, in his accounts of the
phenomena of creation, from the depths of a
language, which, through the force aad unfet-
tered application of intellect, in the regions
of creative fancy, no less than in those of
searching reason, has for centuries influenced
so powerfully all that affects the deitinies of

i

NOTES TO INTRODUCTION.

J (page 4.)— This expression is borrowed from a fine de-
scription of a forest in Bernardin de St.-Pierre's Paul and
Virginia.

8 (p. 5.) — These comparisons are only approximations.
The more accurate elements (heights above the sea-level)
are for the Schnee- or Riesen-koppe, in Silesia, 824
toises, according to Hallaschka ; for the RiGi, 923 t., as-
suming the surface of the Lake of Lucerne to be 223 t.
(Eschmann's Results of Trigonometrical Measurements in
Switzerland in 1840, p 230) ; for Mount Athos, 1060 t.
(Capt. Gaultier) ; for Mount Pilatus, 1180 t. ; for Etna,
1700-4 t., or 10,874 English feet, after Capt. Smyth. Ac-
cording to Sir John Herschel's barometric measurements,
communicated by him to me in 1825, it is 10,876 Eng.ft. =
1700-7 t. ; and, according to Cacciatore, from angular meas-
urements, and, assuming the terrestrial refraction to be =
0-076, it is 10,898 Eng. ft., or 1,704 t. For the ScHRECK-
HORN, 2,093 t. ; the Jungfrau, 2,145 t. (Tralles) ; for
Mont Blanc, according to the results discussed by Roger,
2,467 t. {Bibl. Univ. May 1828, pp. 24— 53) ; whilst Carlini
determined it, from Mont Colombier, in 1821, at 2,460 t. ;
and Austrian engineers, operating fron>Trelod and the Gla-
cier d'Ambin, fixed it at 2,463 t. The actual height of the
Swiss snowy mountains varies, according to M. Eschmann,
about 3i t., owing to the variable thickness of the coating
of snow. For Chimborazo, my trigonometrical measure-
ments give 3,350 t. (Humboldt, Rec. cTObs. astr. vol. i. p.
Liii.) ; for Dhawalaoiri, 4,390 t. All these mountain-
heights are given in toises, of six Paris feet each. As Blake
and Webb's determinations differ by 70 t., I must here re-
mark that the measurements of Dhawalagiri (or White
Mountains, from the Sanscrit dhwala, white, and giri,
mountain), cannot pretend to equal accuracy with those of
Jawahir (4,027 t.= 24,160 Par. ft. = 25,749 Eng. ft.=
7,848 metres), founded on a complete trigonometrical oper-
ation [vide Herbert and Hodgson, in Asiat. Res. vol. xiv. p.
189 ; and Supp. to Encycl. Brit. vol. iv. p. 643). I have
shown in another place {Ann. des Sciences nat. Mars 1825),
that the height of Dhawalagiri (4,391 t. = 26,345 Par ft. =
28,077 Eng. ft.) simultaneously depends on several imper-
fectly settled elements of astronomical positions and azi-
muths (Humboldt, Asie cent. vol. iii. p. 282). Still more
unfounded is the surmise that some snowy peaks of the Tar-
tarian chain, in the north of Tibet, near the Kuenlun chain,
rise to the elevation of 30,000 Eng. ft. (4,691 t., nearly
twice that of Mont Blanc), or at least to 29,000 Eng. ft. or
4,535 t. {vide Capt. Alexander Gerard and John Gerard's
Journey to Boorendo Pass in 1840, vol. i. pp. 143 <fc 311).
Chimborazo is styled " only one of the highest points of the
Andes," since the learned and able traveller, Mr. Pentland,
in 1827, during his memorable expedition to Upper Peru, or
Bolivia, measured two mountains east of Lake Titicaca;
namely, Sorata (3,948 t. = 23,688 Par. ft.) and Illimani
(3,753 1. = 22,518 Par. ft.), which far exceed Chimborazo
(3,350 t. =23.100 Par. ft.) in height, and nearly approxi-
mate to Jawahir f4,0-27 t.), the highest of the hitherto ac-
curately measured Himalayan mountains. Mont Blanc
',2,467 t. = 14,802 Par. fl.) is, therefore, 883 t. lower than
Chimborazo, and Chimborazo 598 t. lower than Sorata,
which is 79 t. lower than Jawahir, but probably 443 1. low-
er than Dhawalagiri. The measurements in this note may
be taken as more accurate from being given in various
scales, since false reductions of those scales have led to er-
roneous numerical statements in Moslem maps and profiles.
Pentland's more recent measurements of Illimani, in 1838,
gives 7,275 met. = 3,732 1. for its height, diflTering only 21 1.
from the measurements of 1827.

3 (p. 5.) — The absence of Palms and arborescent ferns iu
the temperate zones of the Himalaya is shown in Don's
Flora Nepaliensis (1825), as also in the lithographed and re-
markable catalogue of Willich's Flora [ndica,—a. catalogue
•which contains the enormous number of 7,683 almost entire-
ly phanerogamous Himalayan species, although not yetsuffi-
ciently examined and classified. We as yet know of only
one species of palm, Chamxrops Martiana, Wall. (Plant.
Asiat. vol. iii. p. 5, t. 211) in Nepaul (lat. 26^°— 27^0;,
5,00U feet above the sea, in the shady valley of Bunipa.
The splendid arborescent fern, Alsophila Brunoniana, Wall.
of which the British Museum has had a stem, 45 feet long,
since the year 1831, does not come from Nepaul, but from
the mountains of Silhet, north-east of Calcutta, lat. 24° 50'.
The Nepaul fern, Peranema cyathoides, Don, formerly
Sphsropteris barbata, Wall. (op. cit vol, i. p. 42, t. 48), is

nearly related to the Cyathea, of which I saw a species, 30
feet high, in the South American Missions of Caripe ; bu
it was still no tree, properly so called.

4 (p. 5.) — Ribes nubicola, R. glaciale, R. CTossularia.
In spite of a declaration of the ancients on " Eastern Asia"
(StPdbo, lib. xi. p. 510, Cas.), the vegetation of the Hima-
layas is characterized by 8 species of Pinus, 25 oaks, 4 birch-
es, 2 species of Aesculus (the 100 feet high wild chesnut-
tree of Cashmir is inhabited up to 33° N. lat. by a great
white ape with a black face — Charles von Hiigel, Kashmir,
1840, part ii. p. 249), 7 maples, 12 willows, 14 roses, 3 straw-
berry species, 7 Alpine roses (Rhododendra), one of which
is 20 feet high, and many other Northern forms. Amongst
the Coniferae we find the Pinus Deodwara, or Deodara (prop-
erly deivaddru, god-timher,) nearly related to Pinus Cedrus.
Near the eternal snows the Gentiana venusta, G. Moorcrof-
tiana, Swertia purpurescens, S. speciosa, Paruassia armata,
P. nubicola, Paeonia Emodi, Tulipa stellata, display their
large blossoms. Even next to the peculiar Hindoo mount-
ainous species of European orders, we find eight genuine
European species, as Leontodon taraxacum. Prunella vul-
garis, Galium Aparine, Thlaspi arvense. The heath, al-
ready mentioned by Saunders, in Turner's Journey, and
which has even been confounded with Calluna vulgaris, is
an Andromeda — a fact of great importance for the geogra-
phy of Asiatic plants. If, in this note, I make use of the
unphilosophical expression, "European forms, or European
species, growing wild in Asia," it is a consequence of th*
ancient Ixjtanical language, which very arbitrarily subjects
the idea of the distribution, or rather of the coexistence of
organic forms, to the historical hypothesis of an immigra-
tion, even premising a movement from west to east, out of
prejudice to European cultivation.

6 (p. 5.) — The snow-line of the southern declivity of the
Himalayan chain is 2,030 1. = 12,180 ft. above the sea-level,
whilst on the northern side, or rather on the peaks which
rise, in 30^° to 32° lat., above the Tartaro- Tibetan table-
land, it is 2,600 t. = 15,600 ft., the snow-line being at the
height of only 2,470 1. = 14,820 ft. under the equator in the
Quito Andes. I have deduced this result from comparing
together several observations of Webb, Gerard, Herbert, an<i
Moorcroft. Vide my two Memoires sur les montagnes de
VInde of 1816 and 1820 in the Ann. de Chimie et de Phy-
sique, torn. iii. p. 303 ; tom. xiv. pp. 6, 22, 50. The eternal
snow-line on the Tibelan declivity is a consequence of the
radiation of heat by the near table-land, of the serenity of
the sky, and of the scanty formation of snow in very dry
cold air (Humboldt, Asie cent. tom. iii. pp. 281—326). The
conclusion, in regard to this line on both sides of the Him-
alayas, which I proposed as the more probable one, had the
sanction of Colebrooke's great authority. "I find," as he
wrote to me in June 1824, *' that the height of the eternal
snows, according to the materials which I possess, is 13,000
English feet (= 2.033 1.). On the southern declivity, under
the parallel of 31°, Webb's measures would give me 13,500
Eng. ft. (= 2,111 t.), or 500 feet more than Captain Hodg-
son's observations. Gerard's measurements perfectly con-
firm your announcement, that the snow-line is higher on
the northern than on the southern side." Only in this year
(1840) have we at length received, through Mr. Lloyd, a
copy of the entire journal of both the brothers, Gerard (Nar-
rative of a Journey from Caunpoor to the Borrendo Pass, iu
the Himalaya, by Captain Alexander Gerard and John Ge-
rard, edited by George Lloyd, vol. i. pp. 291, 311, 320, 327,
and 341). A great deal on single localities is comprised in
the " Visit to the Ghatool, for the purpose of determining
the line of perpetual snow on the southern face of the Him-
alaya, in August 1822;" but, unfortunately, the travellers
always confound the height where accidental snow falls,
with the maximum height at which the snow-line rises over
the Tibetan plateau. Captain Gerard distinguishes the
peaks in the middle of the plateau, the eternal snow-line of
which he fixes at from 18,000 to 19,000 Eng. ft. (= 2,815 to
2,971 t.), and the northern declivities of the Himalayaa
chain, which limit the passage of the Sutlej, and where the
plateau is deeply furrowed, with, of course, little radiation.
The village Tangno is placed only at 9,300 Eng. ft.
(= 1,454 t.), whilst the plateau about the sacred lake, Ma-
nasa, is said to be 17,000 Eng. ft. (= 2,653 t.) high. Capt.
Gerard finds at the break in the chain, that the snow is
500 Eng. ft. (= 78 t.) lower on the, northern declivity than
on the southern towards India ; on which latter face the
snow-line is estimated by him at 15,000 Eng. ft. (= 8,346 1.).

le

NOTES TO INTRODUCTION.

The botanical relations offer the most striking differences be-
tween the Tibetan table-land and the southern aspect of the
Himalayan chain. In the latter, the harvest (and the com
is often cut green) extends to 1,560 t. only; the upper
woody limit, with tall oaks and Dewadaru firs, to 1,870 t.,
low dwarf birches to 2,030 t. On the plateau, Capt. Ge-
rard saw pastures up to 2,660 1. ; cereals prosper up to
2^200 t., and eren to 9,900 1. ; tall birches to 2,200 t. ; un-
derwood, for fuel, to 2660 t., that is, 200 t. higher than the
eternal snow-line under the equator at Quito. It is most
desirable that travellers, accustomed to general views,
should re-determine the mean altitude of the Tibetan table-
land, which I assume to be 1,800 t., between the Himalaya
and Kuen-lUn, as also the relative glacial heights on the
northern and southern declivities. Hitherto estimates have
been often bonfounded with actual measurements, and the
heights of some prominent peaks, with that of the table-
land wherefrom they rise (compare Carl Zimmermann's
acute hypsometric remarks in his " Geog^phical Analysis
of the Map of the Interior of Asia," 1841 , p. 98). Mr. Lord
directs our attention to a contrast between the heights of
eternal snow on both declivities of the Himalaya and the
Apine chain, Hindoo Koosh. " In the latter," he says,
** we find the table-land in the south, and the altitude of
the snow-line is consequently greater on the southern de-
clivity: the reverse of the Himalaya, which is bounded by
warm plains on the north, as the Hindoo Koosh is on the
south." However considerable the critical corrections that
may be required for these several details, it is still an in-
disputable fact, that the wonderful configuration of a por-
tion of the earth's surface in the interior of Asia allows to
the human race the possibility of propagation, food, fuel,
and colonization, at a height above the sea-level, which, in
almost every other district of both continents (excepting the
parched, snow-free Bolivia, where Pentland found the snow-
line under 160—17^° s, lat. at the mean height of 2,450 t.
in 1838,) is eternally covered with ice. The probable dif-
ferences of the north and south declivities of the Himalaya
range, in regard to the eternal snow-line, have been amply
confirmed by the barometric measurements of Victor Jacque-
mont, who so early became the victim to his noble and un-
tiring zeal {vide his " Correspondance pendant son Voyage
dans I'Inde, 1833, tom. i. p. 299 ; and "Voyage dans I'lnde
})endant less ann*es 1828 i 1832, livr,23, pp. 290,296, 299).
" The eternal snows," says Jacquemont, *' descend lower
on the southern than on the northern declivity of the Him-
ilaya, and their limit constantly rises as we advance to the
north of the border-chain of India. On the Kioubrong peak,
4581 metres high (2863 t.), according to Captain Gerard, I
was still considerably beneath the limit of the eternal
snows, which in this part of the Himalaya I believed (cer-
lainly too great— Humboldt) to be at 6,000 metres = 3078 1."
The same traveller observes, that, to whatever height we
rise on the southern declivity, the climate retains the same
character, the same division of seasons, as in the plains of
India. " The summer solstice brings the same showers of
rain, which uninterruptedly last until the autumnal equi-
nox. Only at Kashmir, which I have found to be 5,350
Eng. ft. high," (=837 t., therefore nearly that of the cities
Merida and Popayan,) " begins a new and distinct climate."
—Jacquem. Corresp. tom. ii. pp. 58 and 74. Leopold von
Buch accurately remarks that the monsoons do not impel
the moist and warm sea-air of the Indian lowlands across
the Himalayan barrier to the tramontane Tibetan district
of Ladak and Lhassa. Carl von Hi}gel estimates the height
Df the valley of Kashmir above the sea-level, from observa-
tions of the boiling point of water (Part ii. p. 155, ant. ;
Journal of the Geog. Soc. vol. vi. p. 215) at 5,818 Eng, ft.
(= 910 t.). In this perfectly calm and almost tempest-free
ralley, under 34<^ T lat., the snow lies many feet deep from
December to March.
^ 'P 5.}— See generally my " Essai >ur la G^graphie

des Plantes et Tableau Physique des Regions equinoxrales,*
1807, pp. 80—88 ; on the diurnal and nocturnal oscillations
of temperature in the ninth plate of my " Atlas giog. et
phys. du nouveau Continent," and the tables to my work,
"De distributione geographica plantarum secundum cdbU
temperiem et altitudinem montium," 1817, pp. 90—116; the
meteorological portion of my " Asie centrale," torn. iii. pp.
212—214 ; lastly, the more recent and accurate account of
the height-decreasing temperature among the Andes in Boos-
singault's " M6moire sur laprofondeur A laquelle on trouve
la couche de temperature invariable sous les tropiqaes,"
Ann. de Chimie et de Phys. 1833, tom. liii. pp. 225—247).
The essay last quoted contains the determination of the
height and mean temperature of 128 points, from the sea-
level to the declivity of Antisana, at 2,800 1. height, between
the aerial temperatures of 27°5 and l©? Cent. (= 81^5 and
350 Fahr.).

7 (p. 6.) — "On the Kawi Language in the island of
Java, with an introduction on diversities in the structure of
language, and their influence on the mental development
of the human race, by William v. Humboldt," 1836, vol. i.
pp. 5—310,

8 (p, 6.)— Respecting the proper Madhjadftga, vide Las-
sen's excellent Indische Alter thumskunde, vol. i. p. 92. The
Chinese term South Bahar Mo-kie-thi, meaning the part
lying south of the Ganges. — Vide Chy-Fa-Hian's Foe-koue'
hi, 1836, p. 256. Djambu-dwipa is entire India, sometimes
comprehending one of the four Buddhist continents.

9 (p. 6.) — Schiller's Elegy, Der Spaziergang, or the
Walk, which first appeared in 1795, in the Horen :—

Within his silent chamber, casting circles
Pregnant with meaning, sits the thoughtful sage —
Creative mind compelling new results : —
Testing the forces that inhere in matter,
Proving the magnet's wondrous hate and love,
Pursuing sound through the air, the ray of light
Through ether, still intent on finding laws
Amidst the incongruous in what seems chaace,
Intent on making out the stable pole
Amidst the flight of mere phenomena.

10 (p. 7,)— Arago's ocular micrometer, a happy improTe-
ment upon Rochon's prismatic or double-refraction microm-
eter, vide M. Mathieu's note in Delambre, " Hist, de I'Astr
au 18™ siecle," 1827, p. 651.

11 (p. 8.) — Cams on the Elementary Parts of the Osse-
ous aivd Crustaceous Frame-work of Animals, 1821, p. 6.

12 (p. 8.) — Plut in vit, Alex. Magn. cap. rii.

13 (p. 8.) — The melting-points of difficultly fusible sub-
stances usually assumed are too high, Mitscherlich's al-
ways accurate researches liniit the melting-point of granite
to 1,3000 C. = 2,372CF.

14 (p. 9.) — Louis Agassiz's classical work on fossil fehes,
•' Recb. sur les Poissons fossiles," 1834, vol. i. p. 38 ; vol.
ii. pp. 3, 28, 34, Addit. p. 6. The entire species Aniblyp-
terus, Agass. nearly related to Palaeoiiiscus (Palaeothris-
sum), is buried beneath the Jura, in the old coal formatbn.
Scales, which, in single layers, are formed like teeth, and
are covered with enamel, from the Lepidoid family (Order
GanoHdes), belong, after Placoides, to the oldest forms of
fossil fishes, whose now living representatives are found in
two species, Bichir (Nile and Senegal) and Lepidosteus
(Ohio).

15 (p, 10.) — Goethe's "Aphorismen Sber Naturwissen-
schaft" (Works, small edit. 1833^ vol, l. p. 155.)

16 (p. 11.) — Arago's discovery in 1811 (Delambre, op. cit.
p. 652).

IT (p. 12.) — Goethe's " Aphoristisches iiber die Natur"
(op. cit. vol. L. p. 4).

18 (p. 12.)— Pseudo-Plato, Alcib. ii. p. 148, ed, Stepb. ;
Flut. Instituta laeosica, p. 253, cd. Huttea.

LIMITATION AND SCIENTIFIC TREATMENT OF A PHYSICAL
HISTORY OF CREATION.

In the general views with which I have open-
ed my prolegomena to a survey of universal na-
ture, I have sought to explain, and, by exam-
ples, to illustrate, how the enjoyment of nature,
diverse in its intimate sources, may be enhan-
ced through clear ideas of the connection of
her phenomena, and of the harmony that reigns
among her actuating forces. It will now be
my endeavour to enunciate more particularly
the spirit and leading idea of the following sci-
entific inquiry ; carefully to separate from it all
that is foreign ; and with comprehensive brev-
ity to convey the scope and contents of the doc-
trine of the Cosmos as I have apprehended and
worked it out, after long years of study in vari-
ous climates of the globe. Let me flatter my-
self with the hope that such an exposition will
bear me out in the bold title I have given my
work, and free me from the charge of presump-
tion. My prolegomena comprise, under four
divisions, and in consonance with my introduc-
tory remarks on the foundation of the laws of
the universe, 1st. The conception and limita-
tion of physical cosmography, as a separate and
distinct science.

2d. The objective contents, the comprehen-
sive empirical survey, of nature at large, in the
scientific form of a general picture.

3d. The reflex action of nature upon the im-
agination and feelings, as stimulating to its
study, through animated descriptions of remote
countries, landscape poetry (a branch of mod-
ern literature), beautiful landscape painting,
the cultivation and contrasted grouping of ex-
otic plants, &c.

4th. The history of creation — in other words,
an account of the gradual development and ex-
tension of the idea of the Cosmos as a natural
whole.

The higher the point of view from which the
phenomena of nature are contemplated, the
more distinctly must the science, the founda-
tions of which are now to be laid, be bounded,
and marked off from all allied departments of
natural knowledge. Physical Cosmography em-
braces the description of all that is created, of
all that exists in space, both natural things and
natural forces, as a simultaneously existing co-
ordinate whole. It divides itself for man, the
inhabitant of the earth, into two principal di-
visions ; one telluric, another sidereal or uran-
ological. To confirm the scientific independ-
ence of physical cosmography, and show its
relations to other departments — to physics or
natural philosophy, to natural history or the
special description of natural objects, to geog-
aosy and comparative geography, or the de-
scription of the earth — we shall first pause
over the telluric portion of our subject. Even
as little as the history of philosophy consists in a
crude arrangement side by side, or in sequence,
of the various philosophical opinions that have
been entertained, so little is the telluric portion
C

of cosmography any encyclopaedic aggregate of
the natural sciences enumerated above. The
lines of demarcation between branches so inti-
mately allied as these, are the more confused
in consequence of the custom which has pre-
vailed for centuries, of designating by specific
titles certain groups of experimental knowl-
edge, which are now too narrow, now too com-
prehensive for the matters comprised, and
which, in times of classical antiquity, and in
the languages from which they were borrowed,
had a totally different signification from that
now attached to them. The titles of particu-
lar natural sciences, such as anthropology,
physiology, natural philosophy, natural history,
geognosy, and geography, arose and became
universally current before mankind had attain-
ed to any clear conception of the diversity of
objects embraced by these several sciences,
and the precise line of demarcation between
each — that is to say, of the grounds of separa-
tion themselves. In the language of one of the
most polished nations of Europe, natural phi-
losophy (physics) is scarcely distinguished from
medicine (physic) ; whilst technical chemistry,
geology, and astronomy, treated in an entirely
empirical manner, are jumbled together, and
papers on all are published under the joint title
of Philosophical Transactions, by a Society
whose fame is justly as wide as the world.

Alterations of old, often ill chosen, but gen-
erally well understood names, for newer titles,
have been repeatedly attempted, but always,
as yet, with indifferent success, by those who
have turned their attention to the classification
of the several departments of human knowl-
edge, from the Margarita Philosophica (a great
Encyclopaedia) of the Carthusian monk Grego-
ry Reisch(^), to Bacon ; from Bacon to d'Alera-
bert, and, not to forget the very latest times,
to the acute geometrician and natural philoso-
pher, Ampere(=*). The unfelicitous choice of
a fantastical nomenclature has perhaps been
more prejudicial to every attempt of the kind,
than the excessive number of divisions and
subdivisions that have been introduced.

Physical cosmography, whilst it embraces
the world " as an object of the external sen-
ses," requires, it is true, the association of gen-
eral physics and natural history as auxiliary
sciences ; but the consideration of corporeal
things, under the guise of a natural whole,
moved and actuated by inherent forces, has an
entirely special character as a distinct science.
Physics occupies itself with the general prop-
erties of matter : it is an abstraction from the
manifestations of force by matter ; and in the
very place where its first foundations, as a sci-
ence, are laid, viz., in the eight books of the
Physics of Aristotle(3), all the phenomena of
nature are represented as vital manifestations
of a general cosmic force. The telluric por-
tion of physical cosmography, to which I will-

18

LIMITATION AND TREATMENT

ingly concede the old title, Physical History
of the Globe, treats, among other matters, of
the distribution of magnetism over our planet,
with reference to intensity and direction ; not
of the laws of magnetical attraction and repul-
sion, nor of the means of exciting electro-mag-
netical effects, now of a more passing, now of
a more permanent character. Physical cos-
mography displays, in bold outlines, the parti-
tionings of continents and the distribution of
their masses in either hemisphere — points that
influence climate and the more important me-
teorological processes in the most remarkable
manner ; it goes farther — it indicates the pre-
vailing characters of the several great mount-
ain ranges, their extension in more continuous
and even chains, or their connections in the
manner of a grating, and their association with
the several epochs and systems of formation ;
it determines the mean height of continents
above the present level of the sea ; the points
of the centres of gravity of their volumes ; the
relations of the higher peaks of extensive chains
to their acclivities, to neighbouring seas, and
to the mineral nature of their constituent rocks ;
it informs us how these mountain masses, now
active and moving, breaking through a super-
imposed crust, now passive and moved, pre-
sent their strata under every variety of inclina-
tion— level, sloping, perpendicular ; it consid-
ers the succession or isolation of volcanoes ;
the indications of their manifestations of activ-
ity, the extent of the circles they severally
shake, and which in the course of centuries
enlarge or contract. It farther informs us, to
select a few examples from the conflict of the
fluid with the solid, of the points of resemblance
between all mighty streams in one part or an-
other of their course : how they are liable to
bifurcate, either in their superior or inferior
channels ; how at one time they cut across
colossal mountain chains at right angles, at an-
other, run in lines parallel to them, whether
this be near the declension of the chain, or at
some considerable distance from it, as a con-'
sequence of the influence which an elevated
mountain system has exerted upon the surface
of entire districts of country, and on the saline
bottoms of neighbouring plains. Only the chief
results of comparative orography and hydrog-
raphy belong to the science which I here cir-
cumscribe, not minute descriptions of mount-
ain masses ; of volcanoes that are now active ;
of the volume of waters of particular rivers,
&c. : all this, according to my views, belongs
to special or descriptive geography, and will be
comprised in the notes which illustrate my
work. The enumeration of similar, or closely-
allied, natural relations, the general survey of
terrestrial phenomena with reference to their
distribution in space, or their relations to par-
ticular zones of the Earth, is not to be con-
founded with the consideration of the individu-
al things of Nature, to wit, terrestrial substan-
ces, animated organisms, physical phenomena ;
a consideration which would only lead to a
systematic arrangement of objects, according
to their intimate analogies.

Special geographical descriptions are, it is
true, the most available material for a general
physical geography ; but the most painstaking
accumulation of such descriptions would as lit-

tle convey to the mind the characteristic idea
of terrestrial nature at large, as the mere co-
ordination of all the individual floras of the
earth would give a notion of the geography of
plants. It is the business of the combining in-
tellect, out of the individualities of organic
forms (morphology, the doctrine of the exter-
nal forms of plants and animals), to extract
the common in climatic distribution ; to fix the
numerical laws — the proportions in the num-
ber of certain forms of natural families, to the
entire number of plants or animals of the more
perfect types ; to determine in what zone each
of the principal forms attains its maximum in
point of numbers of kinds and organic develop-
ment, and even to show how the impression
niade upon the mind by a landscape at different
distances from the equator, in so far as this is
connected with the vegetable growths that
cover the surface of our planet, is mainly de-
pendent on the laws of vegetable geography.

Those systematically arranged catalogues of
organic forms, which in former times were
designated by the somewhat ostentatious titles
of Systems of Nature, present a wonderful
enchainment in reference to similarity of form
(structure), to the conception of a gradual un-
folding or evolution of leaf and calyx into col-
oured blossom and fruit, but not any concate-
nation with reference to distribution in space,
that is to say, to climate, elevation above the
level of the sea, and to temperature, to which
the whole surface of the globe is exposed. The
highest aim of physical geography, however, as
already observed, is the recognition of unity in
multiplicity, the investigation of the Common
and Intimately-connected in all terrestrial phe-
nomena. Where individualities are indicated,
no more is done than may help to bring the
laws of organic arrangement into unison with
those of geographical distribution. The mass
of living forms, in this point of view, appears
to be arranged rather according to the zones
of the earth, or to the course of isothermal
lines, than in conformity with internal rela-
tionship, or the principle of gradation and indi-
vidualizing development of organs inherent in
the whole of nature. The natural sequence of
vegetable and animal forms will therefore be
here assumed from our ordinary descriptive
botany and zoology. It is the province of phys-
ical geography to investigate the mysterious
generical relations in which, with an apparent
dispersion of families and species over the sur-
face of the earth, the most dissimilar forms
still stand to one another ; to show how the
various organisms constitute a natural whole ;
how they modify the atmosphere by the slow
processes of combustion and assimilation that
go on in their interior ; and how, influenced
by promethean light in their evolution, in their
very being, despite their inconsiderable mass,
they act upon the whole life of the globe.

The mode of presenting the subject which I
here propose as alone appropriate to physieal
cosmography, gains in simplicity when we ap-
ply it to the uranological portion of the Cos-
mos, to the physical history of heavenly space,
and of the heavenly bodies. If we distinguish
physics, or natural philosophy, as used former-
ly to be done, but as deeper and clearer views
of nature allow us no longer to do — physics,

OF A SCIENTIFIC COSMOGRAPHY.

19

or the general consideration of matter, of force,
and of motion, from chemistry, or the consid-
eration of the different natures of matter, its
combinations and changes through admixture,
not through affinities in virtue of the simple
relations of mass, we then perceive, in the
telluric region, physical and chemical processes
existing together. Besides that fundamental
property of all matter, attraction at a distance
(gravitation), other forces affect us here upon
earth, which come into operation at infinitely
small distances, or upon immediate contact be-
tween material particles(*), forces which are
designated chemical affinities, and which, called
into action variously by electricity, caloric, and
even simple contact, are incessantly efficient
in inorganic nature, as well as in living organ-
isms. In the celestial spaces we have as yet
no apprehension of any other than physical
processes, affections of matter which depend
on mass alone, and which are subjected to the
dynamic laws of a pure doctrine of motion.
Such affections are regarded as independent of
all qualitative differences — of heterogeneous-
ness or specific difference of matter.

The inhabitants of the earth are brought into
relation with the matter dispersed over space,
only by the phenomena of light and the influ-
ence of general gravitation (attraction accord-
ing to mass). The influences of the sun and
moon upon the periodical variations of terres-
trial magnetism, are still buried in obscurity.
We have no immediate knowledge or experi-
ence of the qualitative nature of the matter
which circulates in, or perhaps fills, the uni-
verse, unless, perchance, it be through the fall
of aerolites, if these heated masses, involved
in vapour, be assumed as constituting small
planetary bodies which have come within the
sphere of the earth's attraction in their course
through space ; an assumption which the di-
rection and extraordinary centrifugal force of
the bodies in question appears to render proba-
ble. The familiar aspect of their constituent
elements, and the identity in nature of these
with such as we have in abundance among the
mineral masses of the earth, are very striking.
They may serve, on analogical grounds, to lead
us to conclusions in regard to the nature of
such planets as belong to the same group, and
have been formed, under the dominion of one
central body, by precipitation from revolving
rings of vaporous matter. Bessel's pendulum-
experiments, which bear the impress of such
accuracy as has never yet been attained, have
given a renewed faith in the truth of the New-
tonian axiom, that bodies of the most dissimi-
lar constitution— water, gold, quartz, granular
limestone, aerolites — experience a perfectly
similar acceleration of motion through the at-
traction of the earth. Many purely astronom-
ical results, indeed, for example the almost
equal mass of Jupiter, in consequence of the
influence of the planet on his satellites, on
Encke's comet, on the small planets Vesta,
Juno, Ceres, and Pallas, assure us that every
where it is the quantity of matter alone which
influences its power of attraction(5).

This exclusion of every appreciable circum-
stance referrible to diversity of material, sim-
plifies the mechanism of the heavens in a re-
markable manner ; it brings the infinite realms

of space under the sole dominion of the laws
of motion; and the astrognostic portion of
physical cosmography draws from established
theoretical astronomy, in the same way as the
terrestrial portion draws from physics, chem-
istry, and organic morphology. The depart-
ments of science just mentioned, indeed, em-
brace phenomena so intricate, and at times so
opposite to mathematical views, that the ter-
restrial portion of the doctrine of the Cosmos
cannot boast of the same certainty and simpli-
city of treatment as the astronomical portion.
In the distinction now indicated lies undoubt-
edly the reason wherefore, in the earlier peri-
ods of the Greek civilization, the Pythagorean
philosophy of nature was rather directed to the
heavens than to the earth ; wherefore it be-
came fruitful, with reference to our solar sys-
tem, in a much higher degree, through Philo-
laus, and, in later times, through Aristarchus
of Samos, and Seleucus the Erythrean, than the
Ionic natural philosophy could prove in regard
to the physics of our globe. More indifferent
as to the specific nature of that which filled
space, as to qualitative differences of matter,
the forces of the Italic school were directed
with Doric earnest upon regulated formations, ' .
on shape, on form and measure alone(®) ; whilst .1^
the Ionic physiologists occupied themselves
especially with the consideration of species of
matter, with their supposed transmutations and
generic relations. It was reserved for the pow-
erful, truly philosophic, and, at the same time,
thoroughly practical mind of Aristotle, to plunge
with equal delight into the world of abstraction,
and into the measureless abundance of material
diversity in organic forms.

Several, and these very excellent works upon
physical geography, comprise an astronomical
section in their introduction, in which the earth
is first considered in its planetary dependence,
or in its relations to the rest of the solar sys-
tem. This plan is the very opposite of that
which I have chalked" out for myself. In a sys-
tem of cosmography, the astronomical portion,
which Kant entitled the Natural history of the
heavens, must not appear as subordinate to the
telluric portion. In the Cosmos, as the old
Copernican philosopher, Aristarchus of Samos,
said, the sun with his attendants is a star
amongst innumerable stars. A general survey
of creation must consequently begin with the
heavenly bodies that occupy space, with a
graphic delineation, a kind of map of the celes-
tial universe, such as the bold hand of the elder
Herschel first ventured to design. If we see
that, despite the relative insignificance of our
planet, the terrestrial portion still occupies the
largest space in the history of the universe, and
is most fully handled, this only happens in re-
spect of the unequal mass of that which is
Known to the inequality of that which is Em-
pirically accessible. This subordination of the
uranological portion we already find in the
great geographer, Bernhard Varenius, in the
middle of the 17th century(0. He distinguish-
es with much acumen between the General and
Special description of the earth, and subdivides
the former, into the absolutely terrestrial and
the planetary, according as the relations of the
surface of the earth in different zones, or the
sol-lunar life of the earth — the relations of our

20

LIMITATION AND TREATMENT

planet to the sun and moon — are considered.
It is a great and enduring honour to Varenius,
that the reahzation of this plan of a General
and of a Comparative Geography attracted
Newton's attention in a very decided manner ;
but owing to the imperfect state of the acces-
sory sciences from which Varenius drew, the
way in which the idea could be carried out was
not in accordance with the grandeur of the con-
ception. It was reserved for our own times to
see comparative geography, in the widest sense
of the expression, even in its reflex on the his-
tory of mankind — the influence which the fig-
ure of continents has had on the course of the
great migrations of the human family, and the
progress of civilization, worked out in the most
masterly manner(^).

The enumeration of the various rays which
unite as in a focus in the natural sciences con-
sidered as a whole, may serve as an apology
for the title of the work which I venture to pro-
duce in the late evening of my life. This title
is perhaps even bolder than the undertaking it-
self, considering the limits which I have pre-
scribed myself In the special departments, I
had hitherto avoided as much as possible the
use of new names for the indication of new
conceptions. Where I attempted any exten-
sion of our nomenclature, it was always con-
fined to individual objects in zoology and bota-
ny. The term. Physical Cosmography, which
I here employ, is imitated from the phrase,
Physical Geography, which has long been fa-
miliar to all. The great extent of the subject
embraced, the purpose of surveying nature at
large, from the remote nebulous specks in the
heavens, to the climatic distribution of the or-
ganic tissues that colour the face of our rocks,
make the introduction of a new term necessa-
ry. And however completely our old and usual
terms earth, and world, blend together, as we
see them in the familiar phrases of, a voyage
round the world, a map of the world, the new
world, &c., this is a mere consequence of the
former more limited knowledge of mankind ;
the scientific distinction between the world, or
universe at large, and the earth we inhabit, is
now felt to be a matter of common necessity.
The grander and more correct expressions,

UNIVERSE, FABRIC OF THE UNIVERSE, CREATION,

and NATURE,* employed to designate the con-
ception and origin of all matter, terrestrial as
well as that of the farthest stars, seem to ap-
prove the propriety of this distinction. To
make this more definite, I might say more sol-
emn and impressive, and also to recur to the
antique name, I have placed the word Cosmos
(KOSMOS) at the head of my work ; this term,
in the Homeric times, having been used to in-
dicate beauty and order, but by and by employ-
ed as a philosophical expression to indicate the
harmony or arrangement of the world, even of
the entire mass of matter filling space, of the
universe at large.

The difliculty of distinguishing the normal—
the regular and legitimate— amidst the cease-
less changes of earthly phenomena, appears at
an early period to have directed the mind of
man, in an especial manner, to the uniform and

* Weltgebftude, Weltkorper, Weltschopfung, Weltraum,
German ; literally Worldfabric, Worldbodies, Worldcrea-
tioD, Worldspace.

harmonious movements of the heavenly bodies.
According to Philolaus, and the concurring tes-
timony of the whole of antiquity ('), Pythagoras
was the first who employed the word Cosmos
as synonymous with creation, with the order
and arrangement of the earth and heavenly
bodies. From the Italic philosophical school,
the word passed into the language of the poets
of nature, Parmenides and Empedocles ; and by
and by it was adopted by the prose writers. It
is beyond my purpose to expatiate in this place
on the various particular applications of the
term, according to Pythagorean views — now to
the planets that revolve around the focus of the
world, now to groups of stars in the firmament ;
or to explain that Philolaus, on one occasion,
distinguishes between Olympus, Kosmos, and
Uranus. In my plan of a cosmography, as this
was understood in times posterior to Pythago-
ras, and as the term is used by the unknown
author of the book, De Mundo, which was so
long ascribed to Aristotle, Cosmos is used to
designate the conception of the heavens and
earth — of the whole of the material universe.
The Romans, in the spirit of imitation, and
when they came to pay a tardy attention to
philosophy, adopted the word Mundus, which
originally signified ornament, never order, for
the designation of the universe. The intro-
duction of the technical term into the Latin
tongue, the literal translation of the Greek Kos-
mos, used in a double sense, is probably to be
ascribed to Ennius(^°), a disciple of the Italic
school, and the translator of the Pythagorean
philosophical speculations of Epicharmus, or of
one of his imitators.

As a physical history of the world, in the wi-
dest sense of the word, were the materials ac-
cessible for such an undertaking, would pass in
review the changes which the Cosmos under-
goes in the lapse of time, from the new stars
which suddenly make their appearance in the
heavens, and the nebulae which either dissolve
.and disappear, or become condensed in their
centres, to the most insignificant vegetable tis-
sue that first covered the cold crust of the earth,
or that gradually and progressively overspreads
the coral reef which rises from the bosom of
the ocean, so would a physical description of
the world, on the other hand, portray the co-
existent in space, the simultaneous agency of
the natural forces, and of the concrete forms
that are the product of these forces. The Ex-
isting, however, in our conception of nature, is
not to be absolutely distinguished or separated
from the Coining into Existence ; for it is not
the organic alone that is to be conceived as
ceaselessly involved in coming into being and
ceasing to be ; the whole life of the globe, in
each stage of its existence, refers us to earlier
conditions that have been successively passed
through. The various superimposed strata, of
which the outer crust of our earth consists in
principal part, inclose the remains of a creation
that has almost entirely disappeared ; they give
us to wit •f a series of formations, which, in
groups, have successively supplanted one an-
other ; they disclose to the eye of the observer
the aggregate faunas and floras of bygone mil-
lenniums. In this sense, the Description of
Nature, and the History of Nature, are not en-
tirely to be dissevered. The geologist cannot

OF A SCIENTIFIC COSMOGRAPHY.

31

apprehend the present without understanding
the past. Each penetrates the other, and blends
in a natural picture of the globe ; just as in the
vast domain of language, the etymologist finds
reflected in various states of grammatical forms,
in their rise and progressive development, the
whole of the present in the past. But this re-
flection of what has been, is by so much the
clearer in the material world, as we now see
several products forming themselves under our
eyes. Among mountain masses, to choose an
example from geology, trachytic cones, basalt,
layers of pumice and amygdaloidal scoriae, en-
liven the landscape in a remarkable manner.
They work upon our imagination like tales from
antiquity ; their form is their history.

Existence in its whole extent and intimacy
is first completely known as a something that
has become. To this original blending of con-
ceptions, classic antiquity bears witness in the
use of the word History, both by Greece and
Rome. If not included in the definition which
Verrius Flaccus(^^) gives of the term. History
is used in the zoological writings of Aristotle
to signify a narrative of things investigated, of
matters recognized by the senses. The de-
scription of the World of the elder Pliny bears
the title Historia Natural is ; in the letters of
the nephew, it is more worthily designated " a
History of Nature." In the times of classical
antiquity, the early historian makes little dis-
tinction between descriptions of countries and
the narrative of events of which these countries
were the theatre. Physical geography and his-
tory continued long to present themselves pleas-
antly mingled together, until increasing politi-
cal interests, and deeper movements in civic ex-
istence, pushed aside the former element, which
then took its place as a separate department of
human science.

To embrace the multiplicity of the phenom-
ena of the Cosmos in unity of thought, in the
form of a purely rational series, is not, as I
conceive, possible in the present state of our
empirical knowledge. The sciences of experi-
ment are never complete ; the realm of the im-
pressions of sense is not to be exhausted ; no
generation of men will ever have it in their
power to boast, that they have surveyed the
whole of the world of phenomena. It is only
where phenomena can be grouped, and separ-
ated from one another, that we recognize in
the individual groups the empire and agency of
grand and simple natural laws. The more the
physical sciences improve, the wider also does
the boundary of this empire extend. Brilliant
instances of the truth of this have been afford-
ed by recent views of the processes going on
in the solid crust of the globe, as well as in the
atmosphere, which depend on electro-magnetic
forces, on radiant heat, and the propagation
of pulses of light ; brilliant examples, too, are
supplied by the late insight gained into the laws
of organic evolution, where all that is to be, is
indjcated beforehand, where the continuous
growth and progressive development of cells
give rise to all the varied tissues of plants and
animals. In this generalization of laws, which
at first seemed only to comprise much narrow-
er circles, mere isolated groups of phenomena,
there are numerous grades. The empire of
recognized laws gains in extent, that of ideal

connection in clearness, so long as inquiries
are pursued in what may be called analogous
and allied masses. But where our dynamic
views, which are based on figurative atomic
premises, no longer suffice us, because the spe-
cific nature of matter, and its heterogeneous-
ness come into play, we find ourselves striking
suddenly upon reefs that rise from fathomless
depths, when we strive after unity of compre-
hension. Here the operation of a new kind of
force is unfolded. The law of definite propor-
tions, or numerical relations, which the genius
of modern chemistry has recognized, and has
applied so happily, so brilliantly, but still under
an antique vesture, in the symbols of atomic
representative expressions, has yet remained
isolated, has not been brought under the do-
minion of the laws of pure dynamics.

The individualities to which all the imme-
diate perceptions of the mind are limited, can
be logically arranged into classes and families.
Such arrangements lead, as I have already had
occasion to remark, in so far as Nature is con-
cerned, to the high-sounding titles of Systems
of Nature. They facilitate the study, it is true,
of organic forms and their linear enchainment
with one another ; but as catalogues, they pre-
sent a mere formal enumeration ; they intro-
duce more of unity into the exposition than
into the knowledge itself As there are de-
grees in the generalization of natural laws,
according as they comprise larger or smaller
groups of phenomena, wider or narrower cir-
cles of organic forms and members, so are
there also grades in empirical inquiry. It be-
gins with isolated views, which are separated
and ordered according to their kinds. From
observation it goes on to experiment, to evo-
cation of phenomena under determinate con-
ditions, according to guiding hypotheses ; in
other words, according to the presentiment of
the intimate connection of natural things and
natural forces. What is attained through ob-
servation and experiment, leads, on grounds
of analogy and induction, to the knowledge of
empirical laws. These are the phases through
which observing intellect must pass, and which
indicate, at the same time, particular epochs
in the history of natural science among men.

Two forms of abstraction dominate the en-
tire mass of our knowledge : one, quantita-
tive, indicative of relationship according to
number and volume ; the other, qualitative,
relationship in reference to material constitu-
tion. The former, and more accessible form,
belongs to the mathematical, the second to the
chemical sciences. In order to subject phe-
nomena to calculation, matter is assumed as
composed of molecules, or atoms ; the number,
form, position, and polarity of which give oc-
casion to phenomena. All myths about im-
ponderable matters and special vital forces in-
herent in organized beings, only render views
of nature perplexed and indistinct. Under great
variety of conditions and forms of apprehen-
sion, the heavy burthen of our accumulated,
and still accumulating knowledge, is moved
lazily and reluctantly. Reason, boldly and with
increasing success, now seeks to break down
the ancient forms, by means of which, as with
mechanical contrivances and symbols, man has
still been wont to strive to obtain mastery over
rebellious matter.

23

LIMITATION AND TREATMENT

"We are still far from the time when it will
be possible to concentrate all perceptions of
sense, into unity of conception of Nature. It
may even be said to be problematical whether
this time will ever come. The complicated
character of the problem, and the infinity of
the universe, seem almost to render vain the
hope that it ever will. But though the com-
plete solution of the problem may remain un-
attainable, its partial solution may still be an-
ticipated ; the effort, indeed, to understand the
phenomena of the universe is still the highest,
as it is the eternal goal of all natural investiga-
tion. Faithful to the character of my early
writings, as to the nature of my occupations,
which have still been devoted to experiments,
to measurements, to the minute examination
of facts, I limit myself in my present underta-
king to the empirical, or experimental method.
It supplies the only ground upon which I feel
that I can move with less of uncertainty. But
this treatment of an empirical science, or rather
of an aggregate of empirical knowledge, does
not preclude arrangement of the conclusions
come to, in harmony with leading ideas, the
generalization of the special, the ceaseless
search after empirical natural laws.

Knowledge acquired under the guidance of
thought, the attainment of a rational compre-
hension of the universe, holds out yet a higher
object. I am far from blaming efforts in which
I have myself made no trial of my strength,
because their fruits still remain subject of
doubt. Greatly misunderstood, and much
against the views and the counsel of the pow-
erful thinkers whom these, the special matters
that engaged antiquity, have again attracted,
systems of what was called the Philosophy of
Nature, threatened, for a time, to lead men
away from the study of the mathematical and
physical sciences, so important in themselves,
so intimately connected with the material wel-
fare of mankind. The intoxicating delirium of
possession obtained by toil, a peculiarly adven-
turously symbolical language, a schematic dis-
cipline, narrower than ever the middle age of
humanity forced itself into, have, in the youth-
ful misapplication of noble powers, been the
features that distinguished the brilliant, but
short-lived Saturnalia of this purely ideal nat-
ural science — I repeat the expression, misap-
plication of powers ; for the sober spirits dedi-
cated at once to philosophy and to observation,
continued strangers to these excesses. The
conception of Experimental Science in general,
and of a Philosophy of Nature complete in all
its parts, if such perfection can ever be obtain-
ed, cannot stand in contradiction or opposition
to one another, if the Philosophy of Nature,
true to its promise, be the rational comprehen-
sion of the phenomena of the universe. Where
contradiction shows itself, the blame lies in
the hoUowness of the speculation, or in the
arrogance of empiricism, which thinks it gains
more from experience than experience war-
rants

And here the realm of the Spiritual might
be opposed to the Natural ; as if the spiritual,
too, were not contained within the concept of
nature as a whole ! Or Art may be opposed
to Nature, by Art being implied something
more than the idea of the spiritual faculty of

producing which is inherent in man. Yet these
opposites must not lead to such a separation of
the physical from the intellectual as would
make the physics of the universe sink down
into a mere heap of empirically collected indi-
vidualities. Science begins at the point where
mind dominates matter, where the attempt is
made to subject the mass of experience to the
scrutiny of reason ; science is mind brought
into connection with nature. The external
world exists to us only when we receive it into
our interior, when it has fashioned itself with-
in us into a natural perception. Mysteriously
indivisible, as are mind and language, as are
thought and the fructifying word, even so and
to us all consciously, does the external world
blend with the interior in man, with thought
and with emotion. "External phenomena,"
says Hegel, in his Philosophy of History, " are
thus translated into internal conceptions. " The
external or objective world, conceived by us,
reflected in us, is then subjected to the eternal,
necessary, and all-influencing forms of our spir-
itual existence. Our intellectual activity then
exercises itself upon the material that has been
taken in through perceptions of sense. There
is, therefore, a tendency to philosophical ideas
even in the infancy of human society, in the
simplest views that can ever be taken of na-
ture. This impulse is various, more or less
lively, according to the temper of the mind, to
national peculiarity, and to the state of intel-
lectual culture among communities. The work
of the mind begins so soon as thought, impelled
by internal necessity, takes up the material of
sensible impressions.

History has preserved us records of the oft
and variously repeated attempt to comprehend
the world of physical phenomena in its multi-
plicity, to get at the knowledge of a peculiar
penetrating, moving, compounding, and decom-
pounding power pervading the universe. These,
attempts, in classical times, constituted the
physiologies and doctrines of the primeval mat-
ter of the Ionic school, in which, by the side
of a poorly arranged empiricism, a scanty dis-
play of facts, ideal efforts, or efforts to explain
nature upon grounds of pure reason, prevailed.
But the more the material of certain empirical
knowledge accumulated, under the influence of
a brilliant extension of all the natural sciences,
the more did the impulse cool which led men to
seek to comprehend the essence of phenomena,
and to discover their unity as a natural whole,
by the construction of systems prompted by
pure reason. In times that have but recently
gone by, the mathematical portion of natural
philosophy has had to rejoice in a great and no-
ble development. The methods and the instru-
ment (Analysis), have advanced towards per-
fection simultaneously. And what was elicited
in such a variety of ways — by a judicious appli-
cation of atomical premises, by a more general
and more immediate contact with nature, by
the invention and improvement of new instru-
ments, is now, as of old, the common inherit-
ance of mankind, and ought not to be lost to
the freest operations of philosophy, however
changing in her forms. Hitherto, indeed, the
inviolability of the material has run certain
risks in the process of reconstruction ; and in
the ceaseless change of idealistic views, it i9

OF A SCIENTIFIC COSMOGRAPHY.

23

little to be wondered at, if, as finely observed
by Bruno("), " Many regard philosophy as sus-
ceptible of no more than a sort of meteoric ex-
istence, so that even the larger and more re-
markable forms in which she has revealed her-
self to mankind share the fate of comets, which
are not regarded as belonging to the imperish-
able and eternal works of nature, but are mere-
ly reckoned among the number of fiery va-
pours."

Misuse or misdirection of the mental ener-
gies, however, must not lead to any conclusions
tending to degrade intellect ; as if the world of
thought were, from its very nature, the realm
of phantasms and deceptions ; as if the pre-

cious stores of empirical knowledge, which
have been accumulating for centuries, were
threatened by philosophy as by some hostile
power ! It becomes not the spirit of these
times to reject, as groundless hypothesis, eve-
ry generalization of ideas, every attempt, based
upon analogy and induction, to investigate the
concatenation of the phenomena of nature ;
and, among the noble faculties with which na-
ture has so wonderfully furnished man, to con-
demn at one time reason, inquiring, searching
every where for causal connections ; at an-
other imagination, the active, the exciting,
the indispensable to all invention, to all discoT-
ery.

NOTES TO PRECEDING SECTION.

1 (p. J».)— The " Margarita philosophica" of the Carthu-
■i»n prior of Freiburg, Gregorius Reisch, first appeared un-
der the title of " Aepitome omnis Philosophic, alias Mar-
garita philosophica tractans <3e omni genere scibili," vide
the Heidelberg edition of 1486, and that of Strasburg of
1504. In the Freiburg edition of that year, and in the
twelve following editions, which appeared in the short in-
terval till 1535, the first part of the title was omitted. This
work exercised a great influence on the diffusion of mathe-
matical and physical knowledge at the beginning of the 16th
century ; and Chasles, the learned author of the " Aperfu
historique des m^thodes en g6om6trie" (1837), has shown
How important is Reisch's Encyclopedia for the mathemat-
ical history of the middle ages. I have endeavoured, by
means of a passage of the " Margarita philosophica," and
which only occurs in the edition of 1513, to unravel the im-
portant relations of Hylacomilus (Martin Waldseemiiller)
the geographer of St. Di6, who first (1507) named the New
Continent America, with Amerigo Vespucci, with Ren6
King of Jerusalem and Duke of Lorraine, and with the cel-
ebrated editions of Ptolemy of 1513 and 1522. Vide my
'* Examen critique de la g6ographie du nouveau Continent, et
des progres de I'astronomie nautique aux 15e et 16e siecles,"
torn. iv. pp. 99—125.

3 (p. 17.)— Ampere, " Essai sur la Phil, des Sciences,"
1834, p. 25. Whewell's Inductive Philos., vol. ii. p. 277 ;
park's Pantology, p. 87.

3 (p. 17.) — All changes of state in the material world are
reduced to motions. Aristot. Phys. ausc. iii. 1 and 4, pp.
200—201 ; Bekker, viii. 1, 8, and 9, pp. 250, 262, 265; De
gener. et corr. ii. 10, p. 336 ; Pseudo- Aristot. de mundo, cap.
vi. p. 398.

•♦ (p. 19.) — Respecting the question raised by Newton of
the difference between mass-attraction and that otf mole-
cules, vide Laplace's " Exposit. du syst. du monde," p. 384,
and in the *' Supplement au livre x. de la m^canique eel."
pp. 3, 4. — (Kant's Metaphysical Elements of Natural Phi-
losophy, in collective Works, 1839, vol. v. p. 309 ; Peclet's
Physique, 1838, torn. i. pp. 59—63.)

5 (19.) — Poisson, in Conn, des terns pour I'ann^e 1836,
pp. 64 — 66 ; Bessel, in Poggendorff's Annalen der Physik,
vol. XXV. p. 417 ; Encke, in Berlin Academy's Transactions,
1826, p. 257: Mitscherlich's Man. of Chemistry, 1837, vol.
i. p. 353.

6 (p. 19.) — Compare Otfried Miiller's Dorians, vol. i. p.
365.

7 (p. 19.) — " Geographia generalis in qua affectiones gen-
erates telluris explicantur." The oldest Amsterdam edition
(Elzevir) is of 1650 ; the second of 1672, and the third of
1681, were edited by Newton. This all-important work of
Varenius is a Physical Geography in its proper sense.
Since the excellent description of the New Continent by
the Jesuit, Joseph da Acosta (Historia natural de las Indias,
1590), never had the telluric phenomena been so generally
contemplated. Acosta is richer in individual observations ;
Varenius embraces a greater circle of ideas— his residence
in Holland, then the centre of the Commerce of the world,
having connected him with many intelligent travellers.
" Generalis sive universalis Geographia dicitur, qua tellu-
rem in genere considerat atque affectiones explicat, non
habita particularium regionum ratione." Varenius's Uni-
versal Geography {Pars absoluta, ca,p. i. — xxii.) is altogeth-
er a comparative one, although the author uses the term
Geographia comparativa (cap. xxxiii.— xl.) in a much more
restricted meaning. The remarkable parts are the enu-
meration of mountain-systems and reflections, or the rela-
tions of their directions with the whole continents (pp. 66-
76, ed. Cantab. 1681) ; the list of the active and extinct
volcanoes ; the conjunction of results on the division of isl-
ands and island groups (p. 220) ; on the depth of the ocean
compared with the height of the coast (p. 103) ; on the
equal levels of the surface of all open seas (p. 97) ; on the
currents as dependent on the prevailing winds, the unequal
saltness of the sea, and the configuration of the coasts (p.
139) ; the directions of the wind as resulting from differ-
ences of temperature, &c. Excellent likewise are the con-
siderations on the general equinoctial current, from east to
west, as the cause of the gulf-stream which begins at Cape
St. Augustine and breaks forth between Cuba and Florida
(p. 140). The directions of the current along the Western
African coast, between Cape Verd and the island of Fer-
nando Po in the gulf of Guinea, are most accurately de- I

scribed. Varenius considers sporadic islets to be " the ele-
vated ocean-bed ;"— " magna spiritum inclusorum vi, sicut
aliquando montes e terra protrusos esse quidam scribunt"
(p. 215). The edition of 1681, by Newton (auctior et emen-
dattor), unfortunately has no additions by this great man.
There is no mention of the spheroidal flattened figure of the
earth, although Richer's pendulum experiments were pub
lished nine years before the Cambridge edition, but New
ton's " Principia mathematica philosophise naturalis" was
only communicated in manuscript to the Royal Society in
1686. There is much uncertainty about the native country
of Varenius. According to Jocher, he was bom in Eng-
land ; according to the ** Biographie Universelle" (torn,
ilvii. p. 495), in Amsterdam : but the dedication of the
Universal Geography to the burgomasters of this city show?
that both assertions are equally false. Varenius expressly
says that he had fled to Amsterdam, *' his native town hav-
ing been burnt to ashes and completely destroyed in the
long war." These words appear to refer to Northern Ger-
many, and the ravages of the 30 Years' War. Varenius
likewise remarks, in the dedication of his " Descriptio Reg-
ni Japonicae" (Amst. 1649) to the Hamburg Senate, that he
had made his first studies at the Hamburg Gymnasium. It
is probably incontrovertible that this acute geographer was
a German, and, moreover, of Liineburg. (Witten's M6m.
Theol. 1685, p. 2142 ; Zedler's Universal Lexicon, 1745,
part xlvi. p. 187.)

8 (20.)— Charles Ritter's Geography in relation to Nature
and the History of Man, or general comparative geography.

9 (20.) — Koff/iOf, in its original and proper meaning, sig-
nified ornament (for men, women, and horses) ; figuratively,
order, tvralia, and ornament of speech. The ancients unan-
imously assure us that Pythagoras was the first to employ
this word in the sense of order of the world, or world itself.
Not having written himself, the earliest proofs are in the
fragments of Philolaus (Stob. Eclog. pp. 360, 460 ; Heeren's
Philolaos, by Boeckh, pp. 62, 90). We do not cite Timaeus
of Locrus, his authenticity being doubtful. Plutarch (de
plac. phil. ii. 1) decidedly says that Pythagoras was the
first to call the whole universe Cosmos, by reason of the or-
der observed therein : (likewise Galen, hist. phil. p. 429).
In its new meaning, the word passed from the philosophical
school to the poets of nature and the prosaists. Plato con-
tinues to call the celestial bodies Uranos ; but he still styles
the order of the world Cosmos : and, in the Timsus (p. 30,
B.), the universe is called a soul-endowed animal (Koaftos
X^dovliirpvxov). Compare, on the immaterial world-arran-
ging spirit, Anaxagoras Claz. (ed. Shaubach, p. Ill) and
Plutarch (op, cit. ii. 3). With Aristotle (de Caelo, i. 91),
Cosmos is, " World and its Arrangement ;" is is also con-
sidered as specially divisible into the sublunary world, and
the higher above the moon (Meteor, i. ii. 1, and i. iii. 13,
pp. 339, a, and 340, b, Bekk.). The definition of Cosmos,
cited by me in the text, is from the " Pseudo- Aristoteles de
Mundo/' (cap. ii. p. 391), namely: Koayni ian avarrina i\
ov^avou Kal y^j icat twv iv rovroii irepiej(pixivu)v (fujaeuv.
Atyerat Si Kal iTipois Koapoi rf rtjv S\u)v rd|tf re Kal 610x60-
fiTjaii, h-rrd Occjv re Kat 6ta Otuv (f>v^aTTOn(vr]. Most passages
of the Greek writers, on Cosmos are collected — 1. In Rich-
ard Bentley's polemical pamphlet against Charles Boyle
(Opuscula philologica, 1781, pp. 347, 445 ; Dissertation upon
the Epistles of Phalaris, 1817, p. 254) on the historical ex-
istence of Zaleucus, the Locrian legislator : 2. In Noeke's
excellent Sched. crit. 1812, pp. 9—15 : and 3. In Theop.
Schmidt ad Cleom. cycl. theor. met. I. i. pp. ix. 1, 99. The
closer meaning of Cosmos was likewise used in the plural
(Plut. i. 5), as, either every star (celestial body) was so
called (Stob. i. p. 514 ; Plut. ii. 31), or many singular sys-
tenas (world-islands) were assumed in infinite space, each
having a sun and moon (Anaxag. Claz. fragm. pp. 89, 93,
120 ; Brandis's History of Grxco- Roman Philosophy, voL i.
p. 252). As each group became a Cosmos, the universe rd
irdv receives a higher signification distinct from Cosmos
(Plut. ii. 1). The last word is used for the Earth only a
long time after the Ptolemaic age. Bockh has communica-
ted inscriptions in praise of Trajan and Hadrian (Corp.
Insc. GraEC. torn. i. No*- 334, 1306), wherein icoff/to; is used
for oiKOVfiivr], just as we often understand by world only
the earth. The above-mentioned strange threefold divisioa
of space into Olympus, Cosmos, and Uranos, (Stob. i. p.
488; Philolaos, pp. 94—102) refers to the different regions
which surround the hearth of the universe, the Pythagorean

26

NOTES TO PRECEDING SECTION.

'EffTio ToS -navrdi. The inner region, between the earth
and moon, the realm of the variable, is termed Uranos in
the Fragment. The middle portion, that of the unchange-
able orderly circulating planets, is exclusively termed Cos-
mos, after a very partial view. The exterior region, a fiery
one, is the Olympus. " If," says that profound diver into
the affinities of language, Bopp — " if we derive Kdafios from
the Sanscrit root s^ud', purificari, as Pott has done (Etymol.
Researches, part i. pp. 39, 252), we must regard, in respect
to the sounds — 1. that the Greek k (in Koa/Jios) has proceed-
ed from the palatal 5, (expressed by Bopp with an s' and*
Pott with a (;,) like icKa, decern, Gothic taihun, from the
ladian das'an ; 2. that the Indian d' regularly corresponds
(Compar. Gramm. 0 99) to the Greek d, whence we clearly
ascertain the relation oi KoayiOi (for KoOfios) to the Sanscrit
root s'wd', whence Kadapos- Another Indian word for World
is g'agat (pronounce dschagat), properly meaning the going,
as a participle from g'a-gdmi, I go (from the root gd)." In
the inner circle of Hellenic etymology, Kdafioi is (according
to Etym. M. p. 532, 12) nearest connected with Aca^u), or
rather Kaivvixai, whence KEKaojiiyos or KSKuS^ieyoS' Here-
with Welcker (eine Cretische Col. in Theben, p. 23) con-
nects the name KaS/xos, as in Hesychius kuSixos denotes a
Cretan suit of armour. When the Romans introduced the
philosophical technical language of Greece, they similarly
*-nlployed the word mundus, originally-used like Koaixos for
female ornament, to express the world or universe. En-
nius appears to have been the first to venture on this inno-
iration : he says, in a fragment preserved to us by Macro-

bius (Sat. vi. 2), in his strife with Virgil, "mundus cteli
vastus constitit silentio ;" like Cicero, " quem nos luceutem
mundum vocamus" (Timaeus s. de univ. cap. 10). The
Sanscrit root mond, whence Pott (Etym. Res. part i. p. 240) i
deduces the word mundus, unites both meanings of shining
and adorning. Loka signifies world and men in Sanscrit,
like the French monde, and, according to Bopp, is derived
from I6k, to see and illuminate : similarly the Slavonian
sivjet (Grimm's German Gramm. vol. iii. p. 394) is light and
world. This word Welt, which the Germans now use, old
High German wSralt, old Saxon worold, Anglo-Saxon vSruld,
originally denotes, according to Jacob Grimm, only " the
idea of time, sceculum (age of man), not the spacial mundus."
Amongst the Tuscans, the open mundus meant an inverted
dome, which turned its cupola towards the world below,
and imitated the heavenly vault. — (Otf. Miiller's Etruscans,
part ii. pp. 96, 98, 143.) In its narrower telluric significa-
tion, the world appears in the Gothic language as the sea-
{marei, meri) surrounded horizon, as merigard, a sea-gar
den.

10 (20.) — Vide about Ennius, Leopold Krahner's acute
researches in his " Grundlinien zur Geschichte desVerfalls
der Romischen Staats-Religion," 1837, pp. 41—45. Proba-
bly Ennius did not draw from the Epicharmic pieces, but
from poems which went by the name of Epicharmus, and
were written according to his system.

n (p. 21.)— Gellius, Noct. Att, v. 18.

12 (p. 23.)— Schelling's Bruno on the Divine and Natural
Principle of Things, p. 181.

PICTURE OF NATURE.

GENERAL SURVEY OP NATURAL PHENOMENA,

When the human mind essays to dominate
matter — in other words, to comprehend the
world of physical phenomena — when we strive,
in thoughtful contemplation of existing things,
to penetrate the life of Nature in its ample ful-
ness, and to unveil the empire of her various
forces, we feel ourselves raised to an eminence,
whence, in the wide-spread horizon around, in-
dividualities present themselves gathered into
groups, and surrounded with a kind of vaporous
haze. This figurative language is used to give
some idea of the point of view from which we
shall here attempt to survey the universe, and
to present it for contemplation in both of its
spheres — the celestial and the terrestrial. The
boldness of such an attempt I do not conceal
from myself Of all the kinds of representa-
tion to which these pages are dedicated, that
of the General Picture of Nature is by far the
most difficult. Here we do not condescend
upon the minutiae of individual forms ; we only
pause upon the grander masses, whether in the
world of fact or of idea. By separation and
subdivision of phenomena, by a kind of forebo-
ding penetration of the play of obscure forces,
by liveliness of representation, in which the
impression made on the senses is reflected true
to nature, may we hope to grasp and to describe
the Infinite All (rd nuv), in a way that shall be-
come the grand word Cosmos, in its sense of
Universe, Order of Creation, Beauty of Ar-
rangement. May the infinite diversity of ele-
ments that crowd into a picture of Nature so
vast, not disturb the harmonious impression of
repose and unity, which it is the last purpose
of every literary and artistical composition to
convey !

We begin with the depths of space, and the
region of the farthest nebulae; we descend,
step by step, through the stratum of stars to
which our solar system belongs, and at length
set foot on the air- and sea-surrounded sphe-
roid we inhabit, discussing its form, its tem-
perature, and its magnetical tension, till we
reach the life, that, under the stimulus of light,
is evolved upon its surface. A picture of the
universe, therefore, worked with a few grand j
touches, comprehends the immeasurable depths ^
of space, as well as the microscopic organisms ^
of the vegetable and animal kingdom that live '
in our stagnant waters, and cling to the weath-
erworn faces of our rocks. All that the most
careful study of nature, in its present direction, |
up to the passing hour, has discovered, consti-
tutes the material in harmony with which the
canvass is to be filled ; it includes within itself
the evidence of its truth and endurance. A de-
scriptive natural picture, however, such as we
would indicate it in these prolegomena, must i
not present all the individual, all the single ; it
needs not, to be complete, an enumeration of
all the forms of life, of every natural thing and

natural process. Striving against the tenden-
cy to endless subdivision of the Known and
the Collected, the thinker who orders and ar-
ranges must rather seek to escape the danger
of empirical overabundance. A considerable
mass of the qualitative forces of matter, or, to
speak in the language of the philosophers of
nature, of its qualitative manifestations offeree,
is certainly still unknown. The discovery of
unity in totality must, therefore, and on this
account, remain imperfect. Beside the joy,
mixed as it were with wo, which we feel in
knowledge possessed, there dwells in the eager
spirit, unsatisfied with the present, the longing
after yet untrodden, yet unimagined, regions
of knowledge. But such a longing only knits
more firmly the bond which, in virtue of ancient
laws, controlling the very core of the world of
thought, binds the Sentient with the Supersen-
tient ; it vivifies the commerce between that
" which the mind receives from the world with-
out, and that which, from its own depths, it
gives back."

If nature, therefore, or the conception form-
ed of natural things and natural phenomena,
considered in its boundary and contents, be in-
finite, so is she also, with reference to the in-
tellectual powers of man, an incomprehensible,
and, in the general causal co-operation of her
forces, an unresolvable problem. Such an avow-
al is proper where existence and evolution (Be-
ing and to Be) are only subjected to immediate
scrutiny, in circumstances where the empirical
path, and the strictly inductive method, cannot
be quitted for a moment. But if the ceaseless
longing to comprehend nature in its totality re-
main unsatisfied, the history of human progress
in contemplating nature, which is reserved for
another section of the prolegomena, teaches
us, on the other hand, how, in the course of
centuries, mankind have gradually attained to
a partial insight into the relative dependence
of phenomena. It is my duty to pass in review
the contemporaneously known, according to
the measure and the boundaries of the present.
In all that is mobile, changeable in space, mean
numerical values are the ultimate object — they
are the expression, indeed, of physical laws ;
they show us the stable in the change and in
the flight of phenomena. The progress of our
modern measuring and weighing physics is par-
ticularly distinguished by the attainment and
correction of the mean values of certain quan-
tities or masses ; and here, as dwelt on by the
old Italic school, but in a wider sense, we find
those wide-spread, hieroglyphic signs, numbers,
coming into play as powers in Cosmos.

The serious inquirer rejoices in the simplici-
ty of numerical relations, by which are indica-
ted the dimensions of the celestial spaces, the
magnitude of the bodies they enclose, and the
periodic perturbations which these suffer ; the

28

PICTURE OF NATURE.

threefold elements of terrestrial magnetism ;
the mean pressure of the atmosphere, and the
quantity of heat which the sun dispenses in the
course of every year, and in each division of the
year, over the several points of the solid or
liquid surface of our planet. The poet of na-
ture is less satisfied with such results ; the ap-
petite for the marvellous, inherent in the many,
is less appealed to by them. The poet com-
plains that science has made a desert of na-
ture ; the vulgar find many questions returned
to them with doubtful solutions, or declared un-
answerable, which formerly were met without
misgivings. In her graver form, in her less
ample garments, she is robbed of that seducing
grace by which the dogmatic and symbolic
physics of former times sought to deceive the
reason, to occupy the imagination. Long be-
fore the discovery of the New World, it was
thought that land could be seen in the West
from the Canaries and the Azores. These
were phantasms, not produced by any extraor-
dinary refraction of rays of light, but merely by
a longing for the distant, for that which lies be-
yond the present. The natural philosophy of
the Greeks, and the physics of the middle ages,
and even of much later centuries, presented
swarms of such fantastic forms to the imagina-
tion. The mental eye still essays to pass the
horizon of limited knowledge, even as the ma-
terial eye endeavours to pierce the natural ho-
rizon from an island height or shore. Faith in
the unusual and wonderful gives definite out-
lines to every product of imagination, and the
realm of fancy, a strange land of cosmological,
geognostical, and magnetic dreams, is inces-
santly blended with the world of reality.

Nature, in the manifold significance of the
term, now as implying entireness of that which
is, and is becoming ; now as an inherent ac-
tuating force ; and again, as the mysterious
prototype of all phenomena, reveals itself to
the simple sense and feeling of mankind as
something more especially terrestrial, as some-
thing that is near akin to them. We seem at
first to recognize our proper home in the liv-
ing circle of organic formation. Where the
bosom of the earth is adorned with fruits and
flowers, where it supports and nourishes in-
numerable kinds of animals, there does the im-
age of nature come up in living tints before the
soul. We are more immediately connected
with the earth, with the terrestrial ; the cano-
py of heaven, inlaid with shining stars, the
boundless realms of space, belong to a picture,
the magnitude of whose elements — ^hosts of
suns, glimmering nebulous specks, infinity of
space — arouse our wonder and amazement, in-
deed, but still remain foreign to our mind and
feelings, through a sense of desolation, and a to-
tal want of immediate impression through the
presence of organic life. To mankind at large,
therefore, the heaven and the earth have still re-
mained distinct, as the above and the below in
space, in consonance with the earliest notions
entertained on the subject. Were a picture of
nature at large, then, solely intended to meet the
requirements of sense, it would have to be be-
gun with a representation of our proper home
for a foundation. It would first portray the
earth in its dimensions and configuration, in its
increasing densitv and temperature as its cen-

tre was approached, in its solid and fluid su-
perposed strata ; it would exhibit the severance
of sea and land ; the life which in both is evolv-
ed as cellular tissue in plants and animals ;
and the atmospheric ocean, with its waves
and currents, from the bottom of which wood-
crested mountain-chains emerge like reefs and
shoals. After this exhibition of purely terres-
trial relations, the eye would rise to the celes-
tial spaces ; the earth, the well-known seat of
organic formative processes, would now be
contemplated as a planet. It would fall into
the series of bodies which circulate around one
of the innumerable host of self-efFulgent stars.
This sequence of ideas indicates the path pur-
sued in the first contemplation of nature by
the senses ; it still reminds us of the "sea-sur-
rounded disc of earth," which supported heav-
en : it sets out from the station of simple per-
ception, from the known and the near, to the
unknown and the far removed. It corresponds
with the method observed in our elementary
astronomical works, which pass from the ap-
parent to the true motions of the heavenly
bodies.

In a work, however, which undertakes to
speak of the actually known, of that which, in
the present state of science, is held for certain,
or which, in various degrees, is looked upon as
probable, but which does not propose to give
the details upon which results are founded,
another course of procedure appears advisable.
Here we do not set out from the subjective
point of view, from that which regards human
interests. The terrestrial can only appear as
a part in the whole, and as subordinate to this.
The view taken of nature must be general, it
must be grand and free, not contracted by no-
tions of vicinity, of affection, of relative use-
fulness. A physical cosmography, or true pic-
ture of the universe, cannot, therefore, com-
mence with the terrestrial ; it must needs be-
gin with the contents of heavenly space. But
as the spheres of contemplation, in reference
to space, contract, the amount of individual
details, the variety of physical phenomena,
knowledge of the qualitative heterogeneous-
ness of matter, augment. From regions in
which we can only distinguish the empire of
the universal laws of gravitation, we descend
to our planet, to the intricate play of forces
that constitute the life of the globe. The nat-
ural descriptive method now sketched out is
opposed to that which establishes conclusions.
The one enumerates what the other demon-
strates.

Man assumes the external world into his in-
terior by means of certain organs. The phe-
nomena of light make us aware of the exist-
ence of matter in the farthest depths of heav-
en. The eye is the organ by which the uni-
verse is perceived, and the discovery of tele-
scopic vision some century and a half ago has
conferred a power upon later generations whose
limits have not yet been reached. The first
and most general consideration, in Cosmos is
that of the contents of space, the contempla-
tion of division in matter, of Creation, as we
are accustomed to designate all that is or is
about to be. We perceive matter here aggre-
gated into revolving and circulating masses of
most dissimilar density and magnitude ; there

GENETIC EVOLUTION— NEBULA.

99

diffused in the shape of self-luminous clouds or
vapours. If we first turn our attention to
these NEBULA (world-mists, separating into
determinate forms), we discover that they are
in course of suffering change in their state of
aggregation. They present themselves to our
eyes apparently of small dimensions, as round-
ed or elliptical discs, single or in pairs, occa-
sionally connected by a luminous streak ; of
larger size they are variously shaped— elonga-
ted or shooting out into several branches ; or
they look fan-shaped ; or they form sharply de-
fined rings with dark included centres. These
nebulae are believed to be in process of various
and progressive changes, according as the star-
dust or vapour composing them is becoming
condensed, in harmony with the laws of at-
traction, around one or several nuclei. The
number of these unresolvable nebulae — nebulae
in which the most powerful telescope does not
enable us to distinguish a single star — that
have been reckoned, and their position in space
determined, now amounts to about one thou-
sand five hundred.

The genetic evolution, the ceaseless, pro-
gressive formation that appears to be going on
in these portions of infinite space, has led re-
flective minds to the analogy of organic phe-
nomena. As in our woods we observe the
same kind of tree in every stage of growth at
the same time, and from this view, this co-ex-
istence, derive the impression of progressive
vital development ; so do we, in the mighty
garden of the universe, recognise different sta-
ges in the progressive formation of stars. The
process of condensation, indeed, which Anax-
imenes and the Ionic school once taught, seems
here to proceed, as it were, under our eyes.
This object of inquiry and conjecture is pecu-
liarly attractive to the imagination. That
which, in the circles of life, and in all the in-
ternal impulsive forces of the universe, fetters
us so unspeakably, is less the recognition of
Being, than of what is About to be ; even
though the latter be nothing more than a new
condition of matter already extant ; for of
proper creation as an efficient act, of a proto-
genesis of matter, of entity succeeding nonen-
tity, we have neither conception nor expe-
rience.

It is not merely by a comparison of the various
moments of development which are exhibited
by nebulae, in greater or less degrees of con-
densation of their interiors, that astronomers
have inferred changes in their structure. We
have now a series of observations made imme-
diately upon particular nebulae, on the one in
Andromeda, on that which occurs in the ship
Argo, and also in the flocky portion of that
which presents itself in Orion, which led to the
belief that actual changes in their form have
been observed. Inequality of power of light in
the instruments employed, however, different
states of our atmosphere, and other optical
conditions, it must be admitted, render a por-
tion of these results questionable as true his-
torical data.

The peculiar multiform nebulae, the several
parts of which have different degrees of bright-
ness, and which, with a diminution of their
areas, will perhaps become concentrated into
stars, and those nebulae that have been entitled

planetary, the round or somewhat oviform
discs of which shine in every part with a mild
and equable light, are not to be confounded
with nebulous stars. Here there is no appear-
ance of a star projected accidentally, as it
might seem, upon a remote nebulous ground ;
no, the vaporiform matter, the light-cloud,
forms a single mass with the star which it sur-
rounds. From the frequently very considera-
ble magnitude of their apparent diameters, and
the distances whence they glimmer, both plan-
etary nebulae and nebulous stars must possess
enormous dimensions. New and acute con-
siderations(') on the very different influence of
distance upon the intensity of the light of a
disc of measurable diameter, or of a single
self-luminous point, make it not improbable that
planetary nebulae are extremely remote nebu-
lous stars, in which the distinction between the
central star and its hazy envelope has disap-
peared even to our telescopic vision.

The brilliant zones of the southern celestial
hemisphere, between the parallels of 50° and
80°, are particularly rich in nebulous stars, and
concentrated but unresolvable nebulae. The
Magellanic clouds which circulate round the
starless, desolate south pole (especially the
larger of the two), appear, according to the la-
test observations('), " as a wonderftil mixture
of groups of stars, of globular clusters of nebu-
lous stars of different magnitudes, and of un-
resolvable nebulae, which, producing a general
brightness of the field of vision, form a kind of
back-ground to the picture." The aspect of
these clouds, of the light-streaming ship Argo,
of the milky way between the Scorpion, the
Centaur, and the Cross — the whole of the
charming landscape presented by the southern
heavens, has left an indelible impression upon
my mind. The zodiacal light, which rises like
a pyramid from the sun, and in its gentle ra-
diance proves another of the eternal ornaments
of the tropical night, is either an immense neb-
ulous ring rotating betwixt the earth and Mars,
or (but this is less probable) it is the outermost
stratum of the sun's atmosphere itself Be-
sides these luminous clouds and nebulae of de-
terminate form, accurate and still coinciding
observations seem to proclaim the existence
and general diffusion of an infinitely rare, and
apparently not self-luminous matter, which,
OFFERING RESISTANCE, rcvcals Itsclf by lesscu-
ing the eccentricity," and shortening the period
of revolution of Encke's, and perhaps also of
Biela's comet. This impeding aethereal and
cosmic matter may be conceived as in motion,
despite its original tenuity as gravitating, as
condensed in the vicinity of the great body of
the sun, and even as increased in the course
of myriads of years, by vapours thrown off
from the tails of comets.

If we now pass on from the nebulous matter
of the infinities of heavenly space (ovpavov x^p^
To^'), here scattered without form or boundary,
a cosmic world-ether, there condensed into neb-
ulous specks, to the .conglobated solid portions
of the universe, we approach a class of phenom-
ena which are exclusively designated by the title
of stars, or fixed stars. And here, too, the de-
gree of solidity or density of the conglobated
matter is different. Our own solar system pre-
sents us with every grade of mean density ;. in

30

PICTURE OF NATURE.

other terms, of difference betwixt the relations
of volume and mass. When we compare the
planets from Mercury to Mars with the Sun
and with Jupiter, and Mars and Jupiter, again,
with Saturn, we proceed in a descending scale
of density ; selecting familiar objects as stand-
ards of comparison, from matter of the density
of antimony, to matter of the density of honey,
of water, and of pine timber. In Comets,
which, numerically speaking, constitute the
largest portion of the individualized physical
forms of our solar system, the most concen-
trated part, which we call nucleus or head,
still allows the light of the stars to pass through
it unrefracted. The mass of comets, perhaps,
never exceeds the five-thousandth part of the
mass of the earth : so variously do the forma-
tive processes meet us in original and perhaps
progressive conglobations of matter. Setting
out from what is most general, it was especial-
ly necessary to indicate this diversity, not as a
thing possible, but as a reality — as a datum in
universal space.

What Wright, Kant, and Lambert have de-
duced from the conclusions of pure reason, in
♦regard to the construction of the universe, to
the distribution of matter in space, has been
established by Sir William Herschel upon the
securer basis of observation and measurement.
This great, inspired, and yet cautious observer,
first cast the plumb-hne into the depths of
heaven, to determine the boundaries and the
form of the separate cluster of stars which we
inhabit ; and he was the first who ventured to
offer an explanation of the relations in point
of position and distance, of remote nebulous
specks to our own astral system. William
Herschel, as the elegant inscription on his
monument, at Upton, says so happily, "broke
through the barriers of the heavens {ccdorum
perrupit daustra).^^ Like Columbus, he forced
his way into an unknown ocean, and caught a
glimpse of coasts and groups of islands whose
true position it is reserved for future centuries
to determine.

Considerations on the varying intensity of
the light of the stars, and on their relative num-
bers— in other words, their numerical abun-
dance or rarity in equal fields of the telescope
— have led to inferences concerning the une-
qual distances and distribution in space of the
strata which they compose. Such inferences,
considered as leading to cfrcumscription of the
several portions of the universe, do not, how-
ever, admit of the same degree of mathemati-
cal certainty as is attained in all that concerns
our own solar system, the revolutions of double
stars, with unequal velocities, around a com-
mon centre of gravity, and the apparent or ac-
tual motions of the stars in general. W^e are
almost disposed to compare the chapter in our
physical cosmography which discusses the neb-
ulous specks of heaven, with the mythological
portion of general history. They both begin
alike — the one in the twilight of remote anti-
quity, the other in the depths of illimitable
space ; and where reality threatens to disap-
pear, fancy is doubly excited to draw from her
own abundance, and to give form and endurance
to the Indefinite and the Changeable.

If we compare the universe with one of the
isle-studded oceans of our planet, we think

that we can perceive matter distributed group,
wise : now, collected into unresolvable nebu-
lous specks of various age ; now condensed
around one, or several, nuclei, and again round-
ed into clusters of stars, or isolated sporades.
The cluster of stars, the islet in the infinity of
space, to which we belong, forms a lenticular,
compressed, and everywhere distinct or separ-
ate layer, the longer axis of which has been
estimated at from seven to eight hundred, and
the shorter axis at some one hundred and fifty,
distances of Sirius. Presuming that the paral-
lax of Sirius is not greater than that of the
bright star in the Centaur, which has been ac-
curately ascertained (viz. 0" 9128), light would
pass through one distance of Sirius from the
Earth in three years, whilst, from Bessel's ad-
mirable earlier paper(*) on the parallax (0"-3483)
of the remarkable star in Cygnus (the 61st), the
very distinct proper motion of which must ad-
mit of a very close approximation, it follows,
that the light of this star only reaches us after
travelling through space for some nine years
and a quarter. Our stratum of stars, a disc
of relatively moderate thickness, is divided,
through one-third of its extent, into two arms ;
and it is thought that we are placed somewhat
near to this division — nearer to Sirius than to
the constellation of the Eagle, almost in the
middle of the material extension of the layer,
in the line of its thickness, or lesser axis.

This position of our solar system, and the
formation of the whole lens, are deduced by
means of a process of what has been aptly des-
ignated gauging the heavens ; i. e. reckoning
the number of stars included in the same field
of the telescope turned on every side around.
The increasing, or decreasing, number of stars
measure the depth or thickness of the layer in
different directions. Precisely as the point at
which the plummet strikes the bottom deter-
mines the length of the line that it is cast from
the hand, do these soundings of the heavens
give the lengths of the visual ray, when the bot-
tom of the starry depths, or rather, and more
correctly, as there is neither above nor below
here, when the limits of starry space are at-
tained. In the direction of the longer axis, and
where the greatest numbers of stars lie one
behind another, the eye perceives the farthest
off thickly crowded together, connected, as it
seems, by a milky glimmer (light-mist), and pro-
jected, in perspective, upon the visible vault
of heaven in the form of a belt or girdle. This
narrow belt of beautiful, but unequal radiance,
for its continuity is broken by less luminous
spaces, divides into two branches, and, save
where it is interrupted for a few degrees, forms
a great circle upon the hollow sphere of the
heavens. This is in consequence of the po-
sition of our system, near the middle of the
great astral group to which it belongs, and al-
most in the plane of the milky way itself.
Were our planetary system placed far without
the cluster, the milky way would present itself
to the assisted eye as a complete ring, and. at
a still greater distance, as a resolvable disc-
shaped nebula.

Amongst the many self-luminous bodies, er-
roneously designated fixed stars, for they are
all in motion, which constitute our island in the
universe, our sun is the only one which we

THE PLANETS.

31

know, through actual observation, as a central
body in reference to the conglobated masses
of matter, in the shape of planets, comets, and
aerolitic asteroids, which revolve around, and
immediately depend upon him. Among the
multiple or double stars or suns, in so far as
their nature has yet been studied, there does
" not appear to reign the same planetary depend-
ence, in respect of relative motion and illumi-
nation, which characterizes our solar system.
Two or more self-luminous stars, whose plan-
ets and moons — if any such exist — escape our
present telescopic powers of vision, revolve
unquestionably around a common centre of
gravity ; but this centre falls in a space that
perchance is filled with unaggregated matter
(world-mist), whilst with our sun it is always
situated in the inner confines of a visible cen-
tral body. When we consider our sun and
earth, or our earth and moon, as double stars,
and our whole planetary system as a multiple
group of stars, the analogy with the proper
multiple or double fixed stars, which such a
designation presents to the mind, extends no
farther than to motions connected with sys-
tems of attraction of different orders, quite in-
dependently of light evolving processes, and
kinds of illumination.

In this generalization of cosmic views, which
befits the sketch of a Picture of Nature or the
Universe, the solar system to which our earth
belongs may be considered in a two-fold rela-
tionship : immediately, to the several classes
of individualized conglomerate matter — to the
magnitude, the fashion, the density, and the dis-
tance of the bodies of the system ; and, next, in
its relations to other parts of our astral system,
to the sun's change of place within the same.

The solar system, in other words, the very
variously fashioned matter which circulates
about the sun, consists, according to our pres-
ent knowledge, of eleven principal planets, of
eighteen moons or satellites, and of myriads
of comets, three of which, called planetary
comets, never quit the limited spheres of the
proper planets. We may further, with no
slight show of propriety, reckon as falling with-
al in the empire of our sun, as included within the
sphere of his central force — 1st, a ring of va-
porous matter, revolving, in all probability, be-
twixt the orbits of Venus and Mars, certainly
extending beyond the orbit of the earth('), which
is visible to us in a pyramidal form, and is
known under the name of the zodiacal light ;
2d, a host of very small asteroids, whose or-
bits either intersect the orbit of the earth, or
approach it very nearly, and give occasion to
the phenomena of aerolites and falling stars.
When we direct our attention to the complexi-
ty of formations which circulate about the sun
in orbits more or less excentric, unless, with
the immortal author of the " Mechanique Ce-
leste," we regard the greater number of com-
ets as nebulous stars which sweep from one
central system to another(®), we must confess,
that the planetary system, strictly so called —
the group of bodies which revolve, with their
attendant satellites, in but slightly excentric
orbits round the sun — constitutes but a small
portion of the entire system, when the number,
not the mass, of the individuals is made the
basis of consideration.

The telescopic planets, Vesta, Juno, Ceres,
and Pallas, with their mutually intersecting,
much inclined, and more excentric orbits, have
been viewed as constituting a kind of zone of
separation between two divisions of our plan-
etary system, and as forming in themselves a
middle group. According to this view, the in-
ner planetary group, comprising Mercury, Ve-
nus, the Earth, and Mars, presents several re-
markable points of contrast with the outer
group, consisting of Jupiter, Saturn, and Ura-
nus(^). The inner planets, nearer to the sun,
are of moderate dimensions, of greater density,
turn more slowly upon their axes, and very
nearly in the same period of time (twenty-four
hours), are flattened towards their poles in a
less degree, and, with one exception, are un-
accompanied by moons. The outer, and, from
the sun, more distant planets, are vastly larger,
of but one-fifth of the density, more than twice
as rapid in their periods of rotation about their
axes, flattened towards their poles in a much
greater degree, and attended by a far larger
number of moons ; in the ratio of 17 to 1, if
Uranus have actually so many as six satellites.

These general observations on certain char-
acteristic peculiarities of the two great groups,
are not, however, precisely or in all respects
applicable to the particular planets of each
group ; for example, to the ratios of their ab-
solute magnitudes, to their distances from the
central body, to their densities, to the times
of their rotations on their axes, to their excen-
tricities, and to the inclinations of their orbits
and of their axes. We know as yet of no in-
timate necessity, of no mechanical natural
law, like the beautiful law which connects the
squares of the times of revolution with the
cubes of the greater axes, which makes the
six elements of the planets just indicated, and
the form of their orbits, dependent on one an-
other, or on their mean distances. Mars, more
remote from the sun, is smaller than the Earth
or Venus ; he approaches Mercury — the near-
est of all the known planets to the sun — most
closely in his diameter ; Saturn, again, is small-
er than Jupiter, yet much larger than Uranus.
The zone of the telescopic planets, so insignif-
icant in point of volume, lies, in a series of
distances setting out from the sun, immediate-
ly before Jupiter, the most considerable of all
the planetary bodies ; and yet these asteroids,
several of whose discs can scarcely be meas-
ured, are barely one half more in their super-
ficies than France, or Madagascar, or Borneo.
Again, however remarkable the very small
density of all the colossal planets that lie far-
thest from the sun, there is still nothing like a
regular sequence among them(8). Uranus ap-
pears to be more dense than Saturn, even when
Lament's smaller mass, ^y^o J' ^s adopted ; and
although the differences "in point of density of
the inner group of planets (^), are insignificant,
we still find Venus and Mars, on either side of
the Earth, of less density than itself The
time of rotation decreases, it is true, with the
distance from the sun ; but for Mars it is rel-
atively greater than for the Earth, and for Sat-
urn it is greater than for Jupiter. The greatest
excentricities in the elliptical orbits of any of
the planets, occur in those of Juno, Pallas, and
Mercury ; the least in those of Venus and the

39

THE PLANETS.— THE SATELLITES.

Earth, the two planets which follow each other
immediately. Mercury and Venus present the
same contrast in the excentricity of their orbits
which we observe in the four so closely allied
asteroids. The excentricities of Juno and Pal-
las, which are very nearly alike, are three times
greater than those of Ceres and Vesta. It is
the same with reference to the inclination of
the planetary orbits to the plane of projection
of the ecliptic, and to the position of the axes
of rotation on their orbits, this position influ-
encing climate, season, and length of day, still
more than excentricity. The planets which
have the most elongated elliptical orbits, Juno,
Pallas, and Mercury, are also inclined in the
greatest degree, although not in equal meas-
ure, to the ecliptic. The orbit of Pallas is al-
most comet-like, and its inclination is nearly
twenty-six times greater than that of Jupiter ;
while the orbit of the little Vesta, which is so
near to Pallas, scarcely exceeds the angle of
inclination of the orbit of Jupiter six times.
The positions of the axes of the four or five
planets, whose axes of rotation are known with
any degree of certainty, also offer nothing like
regularity of series. Judging from the position
of Uranus's satellites, two of which (the 2d
and 4th) have recently been certainly seen
again, we should say, that the axis of Uranus,
the outermost of all the planets, was scarcely
inclined 11° to the plane of his orbit ; but Sat-
urn, whose axis of rotation almost coincides
with the plane of his orbit, revolves between
Jupiter, whose axis is nearly perpendicular, and
Uranus, where, as we have seen, it is but little
inclined.

The world of planetary formations, in this
brief enumeration of the relations of these bod-
ies in space, is assumed as a fact, as a thing
that exists in nature, not as an object of intel-
lectual intuition, of internal causally-founded
concatenation. The planetary system, in its
relations of absolute magnitude and relative
position of axis, of density, time of rotation,
and different degree of excentricity of orbit,
does not strike us as naturally more necessary,
than is the measure of separation between the
land and the sea on the surface of our planet,
than are the outlines of its continents, or the
heights of its mountain-chains. In this respect
there is no general law discoverable either in
celestial space, or in the inequalities of our
earth's surface. The things that we meet with
are facts in nature, which have proceeded from
the conflict of multifarious forces in operation
under former and unknown conditions. But in
formation ofthe planets, man sees as accident-
al what he is incapable of explaining genetical-
ly. If the planets have been formed out of
separate rings of vaporous matter circulating
round the sun, differences in the density, the
temperature, and the electro-magnetic tension
of these rings, may have given rise to the most
diverse fashions of the conglobated matter ; in
the same way as the amount of the velocity of
projection, and trifling aberrations in the direc-
tion of the projection, may have given rise to
manifold forms and inclinations of the elliptical
Dibits. The attraction of masses, and the laws
of gravitation, have undoubtedly been at work
here, as in the geognostic relations of conti-
nental upheavings ; but we are not to draw

conclusions from the present state of things,
as to the entire series of conditions which have
been passed through from their commence-
ment. Even the law, as it has been styled, of
the distances of the planets from the sun, the
progression from the failing member in which
Kepler was led to suspect the existence of a
planet betwixt Mars and Jupiter, has been found
incorrect numerically for the distances between
Mercury, Venus, and the Earth, and because
of a supposed first member, inapplicable to the
idea of a regular series.

The eleven principal planets which have been
discovered circulating round the sun, are ac-
companied by at least fourteen, and very prob-
ably by eighteen, secondary planets (satellites
or moons). The primary planets are therefore,
in their turn, central bodies with reference to
subordinate systems. And here, in the struc-
ture of the universe, we recognize the same
formative process which the evolution of or-
ganic life so often exhibits to us in the ex-
tremely complex groups of animals and plants,
in the typical repetition of forms of subordinate
spheres. The secondary planets, or moons, oc-
cur in larger numbers in the outer region of the
planetary system, in connection with the three
great planets that lie without the zone formed
by the four telescopic planets. With the single
exception of the earth, all the planets within
this zone are moonless, and the satellite of the
earth is relatively of very large dimensions, in-
asmuch as its diameter amounts to one-fourth
of that of the earth ; whilst the largest of all
the secondaries known, the sixth of Saturn, is
not more perhaps than the yV^' ^"*^ ^^^ largest
of Jupiter's moons, the third, is not above ^'^th
the diameter of its primary. The planets which
have the greatest number of moons are the
most remote, and they are, at the same time,
the largest, the least dense, and the most flat-
tened at the poles. The late measurements
of Madler seem to indicate Uranus as the plan-
et which is flattened towards the poles in the
greatest degree, ■^.^. In the earth and her
moon, whose mean "distance from one another
amounts to 237,000 English miles, the differen-
ces in the masses and the diameters of the two
bodies are much smaller than we are accustom-
ed to meet with them in the primary and sec-
ondary planets, and bodies of a different order
in the solar system('»). Whilst the density of
the earth's satellite is |ths less than that ofthe
earth itself, it would appear, supposing we can
depend on the determinations that have been
come to on the magnitudes and the masses of
the satellites, that of the moons which attend
upon Jupiter, the second is denser than the pri-
mary planet.

Of the fourteen satellites the relations of
which have been determined with something
like accuracy, the system of Saturn presents
instances of the most remarkable contrast in
the absolute magnitudes and distances from
the primary. The sixth satellite of Saturn is
probably not much smaller than Mars, whilst
the earth's moon is only one-half the diameter
of this planet. Next in order, in point of vol-
ume, to the two outermost satellites of Saturn
(the sixth and the seventh), comes the third
and brightest of the moons of Jupiter. On the
other hand, the two innermost satellites of Sat-

SATELLITES, OR MOONS.

S3

cm, which were discovered by Sir William
Herschel, in 1789, with his great 40 foot tele-
scope, and which have been again seen by Sir
John Herschel at the Cape, by Vico at Rome,
and by Lamont at Munich, belong, in common
with the satellites of Uranus, to the smallest of
the visible bodies that enter into the constitu-
tion of our solar system. These satellites, in-
deed, are only to be seen under peculiarly fa-
vourable circumstances, and with the most
powerful telescopes. All determinations of
the true diameters of satellites, deductions of
these from measurements of the apparent mag-
nitudes of small discs, are exposed to many
optical difficulties ; and physical astronomy,
wliich calculates before-hand, and with such
admirable precision, the motions of the heav-
enly bodies, as they are exhibited from our
place of observation, the earth, is more con-
cerned about motion and mass, than volume.

The absolute distance of a satellite from its
primary, is greatest in the case of the outer-
most or seventh satellite of Saturn, which is
half a million of geographical miles* remote,
or ten times as far as the distance of our moon
from the earth. In reference to Jupiter, the
outermost or fourth satellite is ito more than
260,000 geographical miles* from the planet ;
the fifth satellite of Uranus, however, if it actu-
ally exist, must be at the distance of 340,000
miles.

On comparing, in each of these subordinate
systems, the volume of the primary planet, with
the distance of the farthest orbit in which a sat-
ellite has been formed, we discover totally dis-
similar numerical relations. Expressed in sem-
idiameters of the principal planets, the dis-
tances of the farthest satellites of Uranus, Sat-
urn, and Jupiter, are as 91, 64, and 27. Sat-
urn's outermost satelMte, therefore, is but a
very little (y'^th) more remote from the centre
of the primary than our moon is from the earth.
The satellite that approaches its primary most
closely, is undoubtedly the first or innermost
of Saturn, which, in addition, presents the only
instance of a revolution in less than 24 hours.
The distance of this satellite from Saturn's cen-
tre, according to Madler and Beer, expressed in
semidiameters of the primary, is only 2-47, or
20,022 geographical miles.* Thi^ satellite can-
not, therefore, be distant from the surface of
its primary more than 11,870 g. miles; and
from the outer adge of the ring, only 1,229 g.
miles. One who has been a traveller readily
forms an idea of so short a distance, the more
so when he thinks of that bold seaman. Captain
Beechey, having sailed over 18,200 geographi-
cal miles in the course of three years. Recur-
ring to semidiameters of the primary as meas-
ures of distance, we find that the first or inner-
most satellite of Jupiter is no more than six
semidiameters of the planet from his centre ;
our moon, on the contrary, is 60J semidiame-
ters of the earth from its centre. The first sat-
ellite of Jupiter is, nevertheless, 6,500 miles far-
ther from his centre, than our moon from the
centre of the earth.

In the subordinate systems of the satellites,
m other respects, all the laws of gravitation are
reflected that have been established in connec-

* The miles are always German geographical miles, 15
to a degree of the Equator.— Tbanslatok.

tion with the sun and the primaries which re-
volve around him. The twelve satellites of
Saturn, Jupiter, and the Earth, all revolve, like
the primary planets, from west to east, and in
elliptical orbits, which diflfer but little from cir-
cles. It is only the moon, and probably the
first, or innermost satellite of Saturn (0 068),
which have orbits, whose eccentricity surpass-
es that of Jupiter. Bessel's very accurate ob-
servations on the 6th satellite of Saturn show-
that the excentricity here (0 029), exceeds that
of the Earth.

It is only in connection with the satellites of
Uranus, on the extreme limit of the planetary
system, at nineteen times the distance of the
earth from the sun, and where his central force
must be notably diminished, that we find any
thing like contrasts to admitted laws. Instead
of moving, like all the other satellites, in or-
bits but little inclined to the ecliptic, and from
west to east, (the ring of Saturn, a kind of fused
or undivided satellite, not excepted), the moons
of Uranus revolve in planes nearly perpendic-
ular to the ecliptic, and, as Sir John Herschel
has found, after many years of observation, in
retrograde courses from east to west. If the
primary and secondary planets of our system
have actually been formed out of rotating rings
of vapour, by condensations of former solar
and planetary atmospheres, there must have
been strange, and to us altogikher inconceiva-
ble conditions of retardation or counteraction
among the vaporous rings that revolved around
Uranus, to have brought about such a singular
opposition to the motions of the central body
as we observe in his 2d and 3d satellites.

It is highly probable, that the period of rota-
tion of all the satellites is the same as their pe-
riod of revolution, so that they still keep the
same side turned towards their primaries. In-
equalities, as a consequence of slight variations
in the revolution, nevertheless, occasion oscil-
lations of from 6 to 8 degrees — an apparent li-
bration — both in longitude and latitude. We
therefore actually see, in succession, more than
one half of the surface of the moon ; at one
time more of her eastern and northern, at an-
other more of her western and southern limb.
By the libration(") the annular mountain Mal-
apert, which the south pole of the moon covers
at times, is made more visible to us, and then
we obtain a better view uf the arctic landscape
around the mountain-crater, Gioja, as also of
the extensive grey level near Endymion, which
surpasses the Mare vaporum in superficial ex-
tent. In spite of all this, however, three-sev-
enths of the moon's surface remain, and, un-
less some new and unexpected cause of pertur-
bation interferes, will ever remain withdrawn
from our eyes. These cosmic relations remind
us, involuntarily, of a nearly similar position
of things in the intellectual world, in the prod-
ucts of thought, where, in the deep investiga-
tion of the dark elaboratory of nature and the
prime creative power, there are alsa regions
turned from our ken, and that seem unattaina-
ble, though, in the course of thousands of years,
mankind have, from time to time, cajught a
glimpse of some narrow stripe or margin, now
in a true and steady, now in a more false and
flickering light.

We have hitherto regarded the principal plan-

H

COMETS.

ets, their satellites, and the concentric ring
that belongs to at least one of the* outermost
of them, as products of a projectile force, and
as connected with one another by intimate bonds
of mutual attractions.

We have still to speak of Comets, an innu-
merable host, which revolve around the sun in
definite orbits, and from him derive their light.
When we estimate the relative lengths of the
orbits of these bodies, the boundaries of their
perihelia, and the great likelihood of their re-
maining invisible to the inhabitants of the earth,
by the rule of probabilities, we find that they
must amount to such myriads as makes the
imagination pause amazed. Kepler, with the
liveliness of expression that distinguished him,
says, that there are more comets in the depths
of space, than there are fishes in the bosom of
the ocean ; and yet we have scarcely the ac-
curately-computed orbits of some 150 of the
six or seven hundred of these bodies, upon
whose appearance and course through known
constellations we have indications more or less
rude. Whilst the classic nations of the west,
the Ancient Greeks and Romans, occasionally
give the place in the heavens where a comet
was first seen, but never say a word of its ap-
parent course, the ample literature of the Chi-
nese, those accurate observers of nature and
of individual things, contains circumstantial no-
tices of the coRfitellations through which each
comet passed. These notices extend to more
than five hundred years before the commence-
ment of the Christian era, and many of them
are used by astronomers at the present day(").

Of all planetary bodies, comets are those
which, with the smallest masses, occupy the
largest fields of space. The particular obser-
vations that have hitherto been made upon
them, indicate masses much under the joVo*^
of that of the earth ; yet have these bodies tails,
which often extend over many millions of miles,
both in length and breadth. The light-reflect-
ing tail, or cone of vaporous matter which com-
ets emit, has occasionally been observed to be
as long as is the distance of the earth from the
sun, a line which intersects the orbits of two
of the planets, those of Mercury and Venus.
This was the case with the remarkable comets
of 1680 and 1811 ; and it is even probable that
our atmosphere was mingled with the vapour
of the comets' tails of the years 1819 and 1823.

Comets exhibit such variety of forms or ap-
pearances, often appertaining to the individual
rather than to the kind, that a description of
one of these travelling light-clouds — for so
they were called by Xenophanes and Theon of
Alexandria, the contemporaries of Pappus —
can only be applied with certain precautions to
another. The feeblest telescopic comets are
generally without any visible tail, and resemble
the nebulous stars of Herschel. They appear
as rounded, palely-glimmering nebulae, with the
light stronger or more concentrated towards
the middle. This is the simplest type ; but it
is even as little a rudimentary or nascent type
on this account, as it is a type of a planetary
body grown old, and become exhausted by ex-
halation. In larger comets we distinguish a
head, or nucleus, as it is commonly called, and
a simple ar compound tail, which the Chinese
astrononaers entitle, very characteristically, the

brush (sui). In general the nucleus has no def-
inite outline, although, in some cases, it has
the splendour of a star of the first or second
magnitude ; and in the great comets of 1402,
1532, 1577, 1744, and 1843, it had such brill-
iancy, that it could be seen in bright sun-
shine('3). This last circumstance seems to tes-
tify to the existence, in some members of the
family at least, of greater density and a highly
reflective faculty in the mass. But no more
than two comets have yet been seen, which, in
Herschel's great telescope, presented well-de-
fined discs(**); these two are the one of 1807,
discovered in Sicily, and the magnificent one
of 181 1 . The disc of the former appeared under
an angle of 1", that of the latter under an an-
gle of 0"-77, from which an actual diameter of
134 and 107 miles respectively is obtained. The
less precisely defined nuclei of the comets of
1798 and 1805, indicated diameters of no more
than 6 or 7 miles. In several comets that have
been accurately observed, particularly in the
one of 1811, mentioned above, and that was
seen so long, the nucleus, and the misty en-
velope which surrounded it, were wholly sep-
arated from the tail by a darker space. The
intensity of the light of the nucleus does not go
on increasing continuously towards the centre ;
bright zones are repeatedly separated by con-
centric misty envelopes. The tail, as stated,
has appeared now single, now double ; but rare-
ly, although this was the case in the comets of
1809 and 1843, of very different lengths in the
two branches; one comet, that of 1744, has
appeared, which had six tails. The tail, again,
is either straight or curved, now to both sides,
now outwardly (1811), or convex to the side
towards which the comet is tending (1618) ;
occasionally the tail has been waving or flame-
shaped. The tails of tomets are always turn-
ed from the sun in such wise that their axes
produced would pass through the centre of that
luminary; a fact which Biot assures us was
notified by the Chinese astronomers so long
ago as the year 837, but which was first dis-
tinctly mentioned in Europe by Fracastorius
and Petrus Apianus in the 16th century. These
effusions may be regarded as conoidal enve-
lopes, having thicker or thinner walls — a view
upon which several very remarkable optical ap-
pearances may readily be explained.

The several comets, however, are not so
characteristically distinguished by their mere
forms or appearance — they are not in one case
tailless, in another provided with a tail of 104
degrees in length, as was the third of the yeai
1618; we further observe them passing through
a rapid succession of varying formative pro-
cesses. This change of form was most accu-
rately and ably observed by Heinsius, of St.
Petersburgh, in the comet of 1744, and in Hal-
ley's comet, on its last appearance in 1835, by
Bessel, of Konigsberg, by whom it has been
very carefully described. On the part of the
nucleus which was turned towards the sun
there was a kind of tufted emanation apparent.
The rays of this that bent backwards went to
form part of the tail. " The nucleus of Halley's
comet, with its emanations, presented the ap-
pearance of a burning rocket, the train of which
was deflected sideways by a current of air."
The rays proceeding from the head were seen

COMETS.

%5

by Arago and myself from the Parisian observ-
atory on successive nights with very different
appearances("). The great Konigsberg astron-
omer, from numerous measurements and theo-
retical considerations, concluded " that the
outstreaming cone of light departed distinctly,
both to the right and left, from the line of di-
rection towards the sun ; but always returned
to this line again, to pass over to the opposite
side ; that the outstreaming cone of light,
therefore, as well as the body of the comet it-
self, which engenders and throws it out, has a
rotatory, or rather a vibratory motion in the
plane of the orbit." He found, further, "that
the ordinary attractive force of the sun which is
exerted upon heavy bodies, is not adequate to ac-
count for these vibrations;" and is of opinion
*' that they proclaim a power of polarity in the
comet, which keeps one semidiameter of the
body turned towards, the other semidiameter
turned from, the sun ; that the magnetic proper-
ty possessed by the earth may present some-
thing of an analogous nature ; and should the op-
posites of the telluric polarity inhere in the sun,
the influence of this might show itself in the
precession of the equinoxes." This is not the
place for a more particular development of the
grounds upon which explanations that accord
with the phenomena have been built ; but ob-
servations so remarkable("), views of such
magnitude in reference to the most wonderful
class of bodies that belong to our solar system,
could not be passed by unnoticed in this sketch
of a general picture of nature.

Notwithstanding the rule according to which
the tails of comets increase in size an^^ bright-
ness as the perihelion is approach^, and are
turned from the central body of our system,
the comet of 1823 presented Ae remarkable
example of two tails, which ^rmed an angle of
160° with each other, and of which one was
turned from the sun, as usual, whilst the oth-
er was turned towards him. Peculiar modifi-
cations of the polarity, and unequal distribu-
tion and condu(x;ion of this, may, in the rare
instance just quoted, have occasioned a two-
fold and uninterrupted effusion of nebulous

matter(»0

In the natural philosophy of Aristotle, the
phenomena of comets and the existence of the
milky way may be brought into a most strange
juxtaposition or connection. The countless
multitude of stars which compose the milky
way give off a self-igniting or luminous mass ;
and the nebulous streak that divides the vault
of the heavens is therefore regarded by the
Stagirite as a mighty comet, which ceaseless-
ly reproduces itself(^^).

Occultations of the fixed stars by the head
or nucleus of a comet, or its immediate vapor-
ous envelope, might throw some light upon the
physical constitution of these wonderful heav-
enly bodies ; but we have no observations
which give us unquestionable assurance that
any occultation has been observed which was
completely central(i') ; for, as we have above
observed, there are alternate concentric scales
of dense and very rare vapour in the parts ly-
ing near the nucleus. On the other hand,
there is no question of the fact, that on the
29th of September, 1835, the light of a star of
the 10th magnitude passed through an extreme-

ly dense vapour, at the distance of 7"78 from
the central point in the head of Halley's com-
et, according to Bessel's very accurate meas-
urements ; and that the light of this star suf-
fered not the slightest deflection from its rec-
tilinear course at any moment of the passage
through this vapour^"*). Such an absence of
refractive power, if it actually extends to the
centre of the nucleus, renders it difficult to im-
agine that the matter of comets is at all of the
nature of a gasiform fluid. Or, is the absence
of refringent power the mere result of an almost
infinite rarity of a fluid of this description'? or
does a comet consist of segregated particles,
forming a cosmic cloud, which affects the ray
of light passing through it in no greater degree
than the clouds of our atmosphere, which have
no influence in altering the zenith distance of
the fixed stars or the edges of the suni A
greater or less diminution of the light of a fixed
star has indeed been remarked during the pas-
sage of a comet over it, but this has been as-
cribed, with great propriety, to the lighter
ground from which the star appears to stand
out during the occultation.

The most important and decisive observa-
tions which have yet been made upon the na-
ture of the light of comets, are those of Arago
on its polarization. The polariscope of this
distinguislied philosopher gives us information
of the physical constitution of the sun as well
as orthat of comets ; the instrument, in a word,
informs us whether a ray of light that reaches
us after travelling many millions of miles, is
direct or reflected light, and whether, in the
former case, the source of the ray is a solid, a
liquid, or a gaseous body. The light of Capel-
la, and that of the great comet of 1819, were
examined by the same apparatus : the comet
showed polarized and therefore reflected light ;
the brilliant star, as was to have been antici-
pated, proclaimed itself a self-luminous sun(=^).
The existence of polarized light in connection
with the comet, however, was not merely made
known by the inequality of the images ; on the
reappearance of Halley's comet in the year
1835, it was still more distinctly indicated by
the striking contrast of complementary colours,
in accordance with the laws of chromatic po-
larization discovered by Arago, in 1811. But
it still remains undetermined, even by the beau-
tiful experiments just referred to, whether, be-
sides the reflected sun-light, comets have not
also a light proper to themselves. In some, at
least, of the true planets, Venus for example,
it appears to be extremely probable that there
is an inherent independent capacity to evolve
light.

The variable brightness of comets is not al-
ways to be explained from their position in
their orbit, and their distance from the sun. It
certainly points, in particular individuals, to
internal processes of condensation, and of aug-
mented or diminished power of reflecting bor-
rowed light. In the case of the comet of 1618,
as also of the one with a period of three years,
Hevelius observed the nucleus to be lessened
as the sun was approached, increased as he
was quitted ; and this remarkable phenomenon,
so long neglected, has lately been again refer-
red to and confirmed by Balz, the able astrono-
mer of Nismes. The regularity in the altera-

36

COMETS.

lion of volume according to the distance from
the sun is particularly striking. The physical
explanation of the phenomenon cannot well be
sought for in any increased density of the lay-
ers of the world-ether at distances progressive-
ly nearer the sun ; for it is difficult to conceive
the vaporous envelope of the comet's nucleus
as vesicular, and impenetrable to the ether that
fills the universe(").

The very dissimilar excentricities in the el-
liptical orbits of comets has led in recent times
(1819) to brilliant additions to our knowledge
of the solar system. Encke made the discov-
ery of a comet of so short a period that it always
remains within the limits of our planetary or-
bits ; he found that the place of its aphelion or
greatest distance from the sun lay between the
orbits of the telescopic planets and that of Ju-
piter. The excentricity of this comet's orbit is
0-845, that of Juno (the greatest excentricity
among all the planetary orbits) being 0 255.
Encke's comet has repeatedly been seen with
the naked eye, although it is not easily discov-
ered ; it was seen, however, in Europe in 1819,
and, according to Riimker, in New Holland in
1823. The period of this comet is nearly 3|
years ; but from careful comparisons of the
times of its return to the perihelion, the remark-
able fact has been discovered that its periods
from 1786 to 1838 have been going on regularly
contracting from revolution to revolution, viz.,
in the course of 52 years, by one and f'oths of
a day. So remarkable a circumstance has led
to the admission of the very probable existence
of a vaporiform matter diffused in planetary
space, and capable of opposing a certain resist-
ance to bodies in motion through it. Some-
thing of the kind, indeed, seems necessary in
order to bring the most careful consideration of
every source of planetary perturbation into har-
mony with the results of observation and calcu-
lation. The tangential force is diminished, and
A^ith it the greater axis of the cometary orbit.
The value of the constant of resistance appears,
moreover, to be somewhat different before and
after the passage of the perihelion, which is
perhaps to be ascribed to the altered form of
the small nucleus, and to the effect of inequality
in density of the layers of ether in the sun's
vicinity(^^). These facts, and their explanation,
must be reckoned among the number of the
most interesting results of modern astronomy.
And then, if Encke's comet led us at an earlier
period to subject the mass of Jupiter — always
so important in every reckoning of perturbation
— to a closer scrutiny, its course has subse-
quently obtained for us the first, although mere-
ly approximative, determination of an inferior
mass for Mercury.

The first comet of short period, namely,
Encke's, of 3^ years, was followed, in 1826, by
another planetary one, the aphelion of which
lies beyond the orbit of Jupiter, but much within
that of Saturn. This, or Biela's comet, com-
pletes its revolution in 6| years. Its light is
still more feeble than that of Encke's comet.
The motion of both these comets is direct,
whilst that of Halley's is retrograde — contrary
to the motion of the planets properly so called.

Biela's comet presents the first certain in-
stance of the orbit of a comet intersecting that
of the Earth ; its path is, therefore, one of pos-

sible danger — if we can regard as dangero«ir a
phenomenon which has not been observed within
the historical period, and of which the conse-
quences are doubtful. Small masses, possess-
ed of enormous velocities, may certainly exei-
cise a notable force ; but, though Laplace de-
monstrated the mass of the comet 'of 1770 to
be less than the l-5000th of that of the Earth,
he supposes, with a certain degree of probabil-
ity, that the average masses of the comets are
much below the one hundred thousandth part
of the Earth's (about the l-1200th of the moon's;
mass("). We must not confound the passage
of Biela's comet through our earth's orbit, with
its proximity to, or absolute encounter with the
Earth itself When this passage took place on
October 29th, 1832, the Earth was still a full
month off from the point of intersection of the
two orbits.

The orbits of these two comets of short pe-
riod mutually intersect each other ; and it ha.s
been correctly observed("*), that owing to the nu-
merous perturbations which such small celestial
bodies suffer from the planets, it is not impos-
sible for them to encounter, and that, should
this occur about the middle of the month oi
October, the inhabitants of the Earth might be-
hold the extraordinary spectacle of a cosmicat
combat ; in other words, of the mutual pene-
tration of two comets, of their agglutination, or
of their destruction, in consequence of exhaust-
ive emanations. The immense ethereal ex-
panse may have witnessed during millions of
years several events of this kind, consequences
of deviations produced by perturbing masses,
or of originally intersecting orbits ; still the)
are insulated phenomena, having as little gen-
eral influence in modifying the form or state oi
the universt, as the appearance* or extinction
of a volcano Ik the limited sphere of the Earth.

A third planetary comet of short period was
discovered by Fayt on November 22d, 1843, at
the Paris Observator/ Its elliptical orbit ap-
proximates more nearly Vo a circle than that of
any other known comet, za\d is included be-
tween the paths of Mars ar.d Saturn. Tliis
comet (which Goldschmidt say& stretches be-
yond the orbit of Jupiter), is theiefore one of
the few known which has its perihelion oeyond
the orbit of Mars. It accomplishes its revolu-
tion in 7-29 years, and probably owes the pres-
ent form of its orbit to its great proximity to
Jupiter at the close of 1839.

When we consider comets in their closed
elliptical orbits as members of our solar system,
with reference to their major axes, their ex-
centricities, and their periods of revolution, it
seems probable that in the last particular the
three planetary comets (Encke's, Biela's, and
Faye's) are immediately succeeded by Messier's
of 1766 (supposed by Clausen to be identical
with the third comet of 1819), and by the fourth
of 1819, discovered by Blanpain, which Clausen
considers identical with that of 1743, but which,
as well as Lexell's, has suffered great orbital
changes from the proximity and attraction of
Jupiter. These two comets appear to have a
period of from five to six years, and their aphe-
lia fall in the neighbourhood of the orbit of Ju-
piter. From 70 to 76 years are occupied in
their revolutions, by Halley's comet (so impor-
tant in a theoretical point of view, of which

COMETS.

the last appearance, in 1835, was less brilliant
than its former ones had led astronomers to
expect it would prove), by Olbers's comet of
March 6, 1815, and by Pons's comet of 1812,
the elements of which were calculated by
Encke. Both of the latter were invisible to
the naked eye. The great comet of Halley has
already greeted us for the ninth known time ;
Laugier's computations^) having recently de-
monstrated that it is identical with the comet
of 1378, recorded in Ed. Biot's Chinese Cata-
logue of Comets. From 1378 to 1835 its period
lias varied between 7491 and 77-58 years, the
mean having been seventy-six years.

Contrasted with the celestial bodies above
mentioned, we behold another series of bodies
requiring millenniums for their barely determi-
nable periods. Thus, Argelander says that the
splendid comet of 1811 requires 3065 years for
its revolution, whilst Encke fixes 8800 years for
the awfully grand one of 1680. These bodies,
therefore, recede respectively 21 and 44 times
farther from the Sun than Uranus ; that is,
8400 and 17,600 millions of miles. The Sun's
attractive force extends therefore even to this
enormous distance ; but then, whilst the comet
of 1680, at its perihelion, travels at the rate of
53 miles (above 1,300,000 English feet) per sec-
ond, or 13 times faster than the Earth, its ve-
locity hardly attains 10 8 E. feet per second at
its aphelion. The last-mentioned rate is only
thrice greater than the velocity of water in our
most sluggish European rivers, and but half
the velocity which I observed in the Cassi-
quiare, a branch of the Orinoko. Amongst the
immense number of uncomputed or undiscov-
ered comets, there are most probably many
which have a major orbital axis far exceeding
that of the comet of 1680. In order to give
some idea, if not of the extent of the sphere of
attraction, at least of the spacial distance of a
fixed star, or other sun, from the aphelion of
the comet of 1680 (the most distant traveller
of all the celestial bodies of our system, ac-
cording to our present knowledge), I need only
remind the reader that the most recent esti-
mates of parallax still make the nearest fixed
star 250 times farther from the sun than the
aphelion of this comet, which is only 44 times
as remote as Uranus, whilst the star a Cen-
tauri is 11,000, and the star 61 Cygni (after
Bessel's very accurate observations) is 31,000
times more distant than the planet.

After this consideration of the greatest elon-
gations of comets from the central body of the
solar system, let us glance at those which have
approached it most nearly. The instance of
the greatest known proximity of a comet to the
earth occurred with that of Lexell and Burk-
hardt, celebrated for the perturbations it suffer-
ed from Jupiter ; this comet was only six
times the distance of the moon from us on June
28Lh, 1770. In 1767 and 1779, the same comet
twice traversed the system of Jupiter's satel-
lites, without causing the slightest perceptible
derangement in their orbits ; orbits which have
been so thoroughly investigated by physical
astronomers. But the great comet of 1680,
when at its perihelion, was from eight to nine
times nearer to the surface of the sun than
Lexell's was to the earth. On December 17th,
the sun and the comet of 1680 were only one-

sixth of the diameter of the former body apart ;
in other words, seven-tenths of the moon's dis-
tance from us. Owing to the feebleness of the
light of distant comets, perihelia beyond the
orbit of Mars are rarely observable by man ;
the comet of 1729 is, in fact, the only one of
those hitherto computed which has its perihe-
lion between the orbits of Pallas and Jupiter,
and which has been observed beyond the path
of the latter planet.

Since scientific acquirements, some solid, by
the side of much superficial learning, have pen-
etrated in wider circles into social life, the
fears of the possible evils wherewith comets
threaten us have increased in weight, and their
direction has become more definite. The cer-
tainty of there being several periodical comets
within the known planetary orbits, visiting us
at short intervals ; the considerable perturba-
tions which Jupiter and Saturn cause in their
paths, whereby apparently harmless wanderers
of the sky may be converted into peril-fraught
bodies ; the orbit of Biela's comet passing
through that of the earth ; the existence of a
cosmical ether, that resisting and retarding
fluid which tends to contract the orbits of all
the planetary bodies ; the individual diflferences
in the bodies of comets which permit us to
suspect considerable gradations in the quantity
of the mass of the nucleus ; all these circum-
stances amply replace, in multiplicity of grounds,
the dread which, in former centuries, was en-
tertained of flaming swords, and an universal
conflagration to be lighted up by fiery stars.

As the grounds for confidence derivable from
the doctrine of probabilities only operate on the
understanding, are only of avail among the re-
flecting, and produce no effect on gloomy ap-
prehension and imagination, modern science
has been charged, not altogether without rea-
son, with seeking to allay the fears which it
has itself created. It is a principle laid deeply
in the desponding nature of man, in his inhe-
rent disposition to view things on the dark
rather than on the bright side, that the unex-
pected, the extraordinary, excites fear, not
hope or joy^"^). The strange aspect of a
mighty comet, its pale nebulous gleam, its sud-
den appearance in the heavens, have in all
countries, and almost at all times, been held as
portentous indications of change or dissolution
of the old-established order of things. And
then, as the apparition is never more than
short lived, arises the belief that its significance
must be reflected in contemporaneous or im-
mediately succeeding events. And such is the
enchainment of events, that some particular
incident scarcely fails to turn up which can be
fixed upon as the calamity prognosticated. It
is only in these times that a spirit of greater
hopefulness, in connection with the appearance
of comets, has shewn itself among the people.
In the beautiful valleys of the Rhine and the
Moselle, ever since the appearance of the brill-
iant comet of 1811, comets have been regarded
as exerting a favourable influence on the ripen-
ing of the grape ; nor have various years of in-
different vintage, along with the appearance of
other comets, instances of which have not
been wanting, been able to shake the faith n'
the wine-growers of the north of Germany in
their beneficial influences.

3ff

SHOOTING STARS AND AEROLITES.

I now pass from comets to another and yet
more enigmatical class of agglomerated matter,
to the smallest of all asteroids, which, in their
fragmentary condition, and when they have
arrived in our atmosphere, we designate by
the name of Aerolites, or Meteoric Stones. If
I dilate at greater length on these bodies than
I have done on comets, and accumulate those
individual features which should otherwise be
excluded from a general survey of nature, it is
done with a purpose. The very remarkable
characteristic diversities of comets have been
long known. From the little that has yet been
learned of their physical condition, it is diffi-
cult, in an exposition such as is here required,
to seize the Common, and to separate the Ne-
cessary from the Accidental, in phenomena
observed with very difTerent degrees of accu-
racy. The measuring and calculating astron-
omy of comets has alone made marvellous
progress. In this state of our knowledge, a
scientific consideration must be limited to phys-
iognomical differences in the fashion of the
nucleus and tail ; to examples of close approxi-
mations to other planetary bodies ; to extremes
in orbits with reference to space, and in pe-
riods of revolution to time. Natural truth in
these, as in the phenomena that are immedi-
ately to be spoken of, is only to be attained
by a delineation of the Individual, and by the
animated and contemplative expression of re-
ality.

Shooting Stars, Fire-b.^lls, and Meteoric
Stones, are, with great appearance of proba-
bility, regarded as small masses moving with
planetary velocity in conic sections round the
sun, in harmony with the laws of universal
gravitation. When these masses encounter
the Earth in their course, and, attracted by it,
become luminous on the verge of our atmo-
sphere, they frequently let fall stony fragments,
heated in greater or less degree, and covered
on their surface with a black and shining crust.
By careful analysis of all that has been observ-
ed at different epochs when great numbers of
shooting stars have fallen, as at Cumana in
1799, in North America in 1833 and 1834, &c.,
it seems no longer proper to separate fire-balls
from shooting stars. Both phenomena are not
only frequently contemporaneous aitd inter-
mingled, but they also pass into one another,
and this whether we pay particular attention
to the dimensions of the discs, to the sparks or
trains of fire which they emit, or to the veloci-
ties of their respective motions. Whilst there
are fire-balls that have the apparent diameter
of the moon, that explode and emit smoke, and
possess such brilliancy that they can be seen
at noon-day(**), there are, on the other hand,
shooting stars in countless multitudes, of such
small dimensions that they only present them-
selves to the eye in the form of moving points
or of phosphorescent linesC*'). But whether
or not among the many luminous bodies that
shoot through the sky in the form of falling
stars and meteors, there are not several of dif-
ferent natures, remains to be shown. Occu-
pied, shortly after my return home, with the
impression which the phenomena of shooting
stars had left upon my mind, and remembering
that I had observed them in greater numbers,
of brighter colours, and more commonly ac-

companied by long and brilliant trains, both on
intertropical plains just raised above the level
of the sea, and on mountains at the height of
twelve and even fifteen thousand feet above
its surface, than in the temperate and frigid
zones, I soon perceived that the ground of the
more vivid impression lay in the glorious trans-
parency of the tropical atmosphere itsGlf(3'>).
There one sees deeper into space. Sir Alex-
ander Burnes, too, speaks of the magnificent
and constantly recurring spectacle of coloured
shooting stars, which he enjoyed in Bokhara,
and which he attributes to the purity of the at-
mosphere.

The connection of meteoric stones with the
grander and more brilliant phenomena of fire-
balls— that stones actually fall from these fire-
balls, and penetrate ten or fifteen feet into the
ground, has been shown, among many other
instances of the kind, by the well-known fall
of aerolites at Barbotan, in the department Des
Landes, on the 24th July, 1790, at Lima on the
16th of June, 1794, at Weston, in Connecticut,
on the 14th of December, 1807, and at Juvenas,
in the department of Ardeche, on the 15th of
June, 1821. Other phenomena connected with
the fall of aerolites are those where the masses
have descended, shaken, as it were, from the
bosom of a small dark cloud, which had formed
suddenly in the midst of a clear sky, accompa-
nied with a noise that has been compared to
the report of a single piece of artillery. Whole
districts of country have occasionally been cov-
ered with thousands of fragments of stones,
of very dissimilar magnitudes, but like consti-
tution, which had been rained down from a pro-
gressive cloud of the kind described. In rarer
instances, as in that which occurred at Klein-
wenden, not far from Miihlhausen, on the 16th
of September, 1843, large aerolites have fallen
amidst a noise like thunder, when the sky was
clear and without the formation of any cloud.
The close affinity between fire-balls and shoot-
ing stars is also shown by the fact of instances
having occurred, of the former throwing down
stones, though they had scarcely the diameter
of the balls that are projected from our fire-
works called Roman candles. This happened
notably at Angers on the 9th of June, 1822.

With regard to the form-producing forces,
the physical and chemical processes in these
phenomena, we are still completely in the dark.
We know not whether the particles which form
the compact mass of the aerolite lay originally
apart from one another, in the shape of vapour,
as in comets, and first contracted and ran to-
gether when they began to ligliten within the
gleaming ball ; we know nothing of what takes
place in the black cloud, where it sometimes
continues to thunder for minutes before the
stones descend ; neither are we aware wheth-
er from the smaller shooting stars there be any
precipitation of solid matter, or only an attenu-
ated dry haze, or a ferruginous and nickcliferous
meteoric dust(^'). We, however, know the im-
mense, the wonderful and perfectly planetary
rapidity of shooting stars, fire-balls, and mete-
oric stones ; we recognise the General in ref-
erence to them, and in this Generality perceive
uniformity of phenomena only, nothing of ge-
netical cosmic process, the consequence of
change. If meteoric stones revolve already

SHOOTING STARS AND AISROLITES.

39

consolidated into dense masses^^ (less dense, |
however, than the mean density of the Earth), |
then must they form very insignificant nuclei
to the fire-balls, surrounded by inflammable va-
pours or gases, from the interior of which they
shoot, and which, judging from their height and
apparent diameters, must have actual diame-
ters of from 500 to 2600 feet. The largest me-
teoric masses of which we have information,
those to wit of Bahia and Otumpa in Chaco,
which Rubi de Celis has described, are from 7
to 7^ feet in length. The meteoric stone of
Aegog Potamos, so celebrated through the
whole of antiquity, and which is even mention-
ed in the Marble Chronicle of Paris, is described
as having been of the magnitude of two mill-
stones, and of the weight of a wagon load.
Despite the vain attempts of the African trav-
eller, Browne, I have not yet abandoned the
hope that this great Thracian meteoric stone,
which must be so difficult of destruction, though
it fell more than 2300 years ago, will again be
discovered by one or other of the numerous
Europeans who now perambulate the East in
safety. The enormous aerolite which fell in
the beginning of the 10th century in the river
at Narni, projected a whole ell above the sur-
face of the water, as we are assured by a doc-
ument lately discovered by Pertz. It is to be
observed, however, that none of these aerolites,
whether of ancient or modern times, can be re-
garded as more than principal fragments of the
mass which was scattered by the explosion of
the fire-ball or murky cloud whence they de-
scended.

When we duly consider the mathematically
determined enormous velocities with which
meteoric stones fall from the outer confines of
our atmosphere to the earth, or with which, as
fire-balls, they speed for long distances through
even the denser fields of air, it seems to me
more than improbable that the metalliferous
mass, with its internally disseminated and very
perfect crystals of olivine, labrador, and pyrox-
ene, could have run together in so short an in-
terval into a solid nucleus from any state of gas
or vapour. The mass that falls, besides, even
in cases where the chemical constitution varies,
has always the particular characters of a frag-
ment ; it is commonly of a prismatoidal or ir-
regular pyramidal form, with somewhat arched
surfaces and round edges. But whence this
figure, first observed by Schreibers, of a mass
detached from a rotating planetary body 1 Hgre,
too, as in the circle of organic life, all that has
reference to the history of evolution is hidden
in obscurity. Meteors begin to lighten and to
burn at elevations which we must look upon as
almost perfect vacuums, or that cannot contain
l-100,000th of oxygen. Biot's new researches
on the interesting crepuscular phenomenon(23),
reduce the line very notably which, somewhat
hardily perhaps, is frequently spoken of as the
limits of our atmosphere ; but luminous phe-
nomena take place independently of the pres-
ence of oxygen, and Poisson has admitted the
combustion of aerolites, or meteors, as occur-
ring far beyond the confines of our atmosphere.
It is only in so far as calculation and geomet-
rical admeasurement can be applied to meteor-
ic stones, as to the greater bodies of the solar
fiystem, that we feel ourselves proceeding on

surer grounds. Although Halley had already
pronounced the great fire-ball of 1686, the mo-
tion of which was in opposition to that of the
earth, a cosmic phenomenon("), Chladni was
the first (1794) who, in the most general terms,
and most clearly recognized the connection be-
twixt fire-balls and the stones that fall from the
atmosphere, as well as the correspondence be-
tween the motions of these bodies and those
of the planetary masses at large("). A brill-
iant confirmation of this view of the cosmic
origin of such phenomena has been supplied by
Denison Olmsted, of New-Haven, Connecti-
cut, in his observations on the showers of
shooting stars and fire-balls which made their
appearance in the night from the 12th to the
13th of November, 1833. On this occasion, all
these bodies proceeded from the same quarter
of the heavens — from a point, namely, near the
star y Leonis, from which they did not deviate,
although the star, in the course of the length-
ened observation, changed both its apparent
elevation and its azimuth. Such an independ-
ence of the rotation of the earth proclaimed
that the luminous bodies came from without —
from outer space into our atmosphere. Accord-
ing to Encke's calculations of the entire series
of observations that were made in the United
States of North America, between the paralells
of 35° and 42°, the whole of the shooting stars
came from the point in space towards which
the earth was moving at the same epoch(^*).
In the subsequent American observations on the
shooting stars of November 1834 and 1837, and
the Bremen ones of 1838, the general parallel-
ism of their courses, and the direction of the
meteors from the constellation Leo, were per-
ceived. As in the November periodical recur-
rence of shooting stars, a more decided parallel
and particular direction has been noted than in
the case of those that appear sporadically at
other seasons, so in the August phenomenon it
has also been believed that the bodies came for
the major part from a point between Perseus
and Taurus, the point towards which the earth
is tending about the middle of the month of
August. This was particularly remarked in
the summer of 1839. This peculiarity in the
phenomenon of falling stars, the direction of
retrograde orbits in the months of November
and August, is especially worthy of being either
better confirmed or refuted by the most careful
observations upon future occasions.

The altitudes at which shooting stars make
their appearance, by which must be understood
the periods between their becoming visible and
their ceasing to be so, are extremely various ;
in a general way, they may be stated as vary-
ing between four and thirty-five geographical
miles. This important result, as well as the
extraordinary velocity of the problematical as-
teroids, was first arrived at by Benzenberg and
Brandos, by means of a series of contempora-
neous observations and determinations of par-
allax, at either extremity of a base hne 46,000
feet in length("). The relative velocity of the
motion was from four and a quarter to nine
miles per second ; it was therefore equal to
that of the planets(38). such a velocity of
movement, as well as the frequently observed
course of shooting stars and fire-balls in a di-
rection the opposite of that of the earth, lias

40

SHOOTING? STARS AND AEROLITES.

been used as a principal element in combating
that view of the origin of aerolites, in which
they were presumed to be projected from still
active volcanoes in the moon. The supposi-
tion of any volcanic power, of greater or less
energy, inherent in a small planetary body sur-
rounded by no atmosphere, is, indeed, in the
nature of things, and numerically considered,
extremely arbitrary. It is not difficult, indeed,
to conceive the reaction of the interior of a
planet against its crust, as ten or even a hun-
dred times greater than that which we now ob-
serve in connection with the volcanoes of the
earth. The direction of the masses, too,
which could be projected from a satellite mo-
ving from west to east, might appear retro-
grade, in consequence of the earth, in its orbit,
arriving later at the point of its path where the
masses fall. But, then, if the entire circle of
relations, which I felt myself compelled to spe-
cify, even in this general picture of nature, to
escape the suspicion of making unfounded as-
sertions, be surveyed, it will be found that
the hypothesis of a lunar origin of meteoric
stones(^') is dependent on a majority of condi-
tions, the accidental association of which could
alone give to the barely possible, the form and
substance of reality. The admission of the
original existence of small planetary masses
circulating in space, is simpler, and seems more
in harmony with what we know or infer with
reference to the formation of the solar system.

It is highly probable that a great proportion
of these cosmic bodies pass undestroyed in the
vicinity of our atmosphere, and only suffer a
certain deflection in the excentricity of their
orbits by the attraction of the earth. We may
conceive that the same bodies only become vis-
ible to us again after the lapse of several years,
and when they have made many revolutions
round their orbit. The ascent of some fire-
balls and shooting stars (which Chladni en-
deavoured to explain, not very happily, by a
reflection produced by a body of greatly con-
densed air) appears, at first sight, to be a con-
sequence of a mysterious projectile force throw-
ing off the meteors from the earth ; but Bessel
has shown on theoretical grounds, and indeed
proved, by means of Feldt's very accurate cal-
culations, that in the absence of perfect agree-
ment in point of time, of the disappearances re-
corded, there is not one amongst the whole of
the observations published which impresses the
assumption of an ascent, with a character of
probability, none which does not allow us to re-
gard it as an effect of observation(*°). Wheth-
er the explosion of shooting stars, and of the
smoking and flaming fire-balls which do not al-
ways move in straight lines, may force the me-
teors upwards in the manner of rockets, or oth-
er\yise influence the direction of their path, in
certain cases, as Olbers supposes, must remain
matter for further observation.

Shooting stars fall either singly and rarely,
and at all seasons indifferently, or in crowds
of many thousands (Arabian writers compare
them to swarms of locusts), in which case they
are periodical, and move in streams generally
parallel in direction. Amongst the periodic
showers, the most remarkable are those that
occur from the 12th to the 14th of November,
and on the 10th of August ; the " fiery tears"

which then descend, are noticed in an ancient
English church-calendar, and are traditionally
indicated as a recurring meteorological inci-
dent(*^). Independently of this, however, pre-
cisely in the night from the 12th to the 13th of
November, 1823, according to Kloden, there
was seen at Potsdam, and in 1832, over the
whole of Europe from Portsmouth to Orenburg
on the river Ural, and even in the southern
hemisphere, in the Isle of France, a great mix-
ture of shooting stars and fire-balls of the most
different magnitudes ; but it appears to have
been more especially the enormous fall of
shooting stars, which Olmsted and Palmer ob-
served in North America between the 12th and
13th of November, 1833, when they appeared
in one place as thick as flakes of snow, and
240,000 at least were calculated to have fallen
in the course of nine hours, that led to the idea
of the periodic nature of the phenomenon, of
great flights of shooting stars being connected
with particular days. Palmer of New Haven
recollected the fall of meteors in 1799, which
Ellicot and I first described(*''), and from which,
by the juxtaposition of observations which I
had given, it was discovered that the phenom-
enon had occurred simultaneously over the
New Continent from the equator to New-Hern-
hut in Greenland (N. Lat. 64° 14'), betwixt 46°
and 82° of Longitude. The identity in point
of time was perceived with amazement. The
stream, which was seen over the whole vault
of heaven between the 12th and 13th of No-
vember, 1833, from Jamaica to Boston (N. L.
40° 21'), recurred in 1834, in the night between
the 13th and 14th of November, in the United
States of North America, but with something
less of intensity. In Europe, its periodicity
since this epoch has been confirmed with great
regularity.

A second, even as regularly recurring show-
er of shooting stars as the November phenom-
enon, is the one of the month of August — the
feast of St. Lawrence phenomenon — between
the 9th and the 14th of the month. Muschen-
broeck(") had already called attention in the
middle of the preceding century to.the frequen-
cy of meteors in the month of August ; but
their periodic and certain return about the time
of the feast of St. Lawrence was first pointed
out by Quetelet, Olbers, and Benzenberg. In
the course of time other periodically recurring
showers of shooting stars(**) will very certain-
ly h^ discovered — perhaps from the 22d to the
25th of April ; from the 6th to the 12th of De-
cember, and, in consequence of the actual fall
of aerolites described by Capocci, from the 27th
to the 29th of November, or about the 17th of
July.

However independent all the phenomena of
falling stars yet witnessed may have been of
polar elevation, temperature of the air, and oth-
er climatic relations, there is still one, although
perhaps only accidental, accompanying phenom-
enon which must not be passed by unnoticed.
The Northern Lights showed themselves of
great intensity during the most brilliant of all
these natural incidents, that, namely, which
Olmsted has described (Nov. 12-13, 1833).
The same thing was also observed in Bremen
in 1838, where, however, the periodic fall of
meteors was less remarkable than at Rich-

SHOOTING STARS AND AEROLITES.

a

mond, in the neighbourhood of London. I have
also referred, in another work(**), to the re-
markable observation of Admiral Wrangel,
which he has confirmed to me verbally oftener
than once, that during the appearance of the
Northern Lights, on the Siberian shores of the
Icy Sea, certain regions of the heavens which
were not illuminated, became inflamed and
continued to glow whilst a shooting star pass-
ed through them.

The difTerent meteor-streams, each of them
made up of myriads of little planets, probably
intersect the orbit of our earth in the same
way as Biela's comet doee. Upon this view
we may imagine these shoot-star asteroids as
forming a closed ring, and pursuing their course
in the same particular orbit. The smaller tel-
escopic planets between Mars and Jupiter, with
the exception of Pallas, present us, in their
closely connected orbits, with a similar rela-
tionship. It is impossible as yet to decide
whether alterations in the epochs at which the
stream becomes visible to us, whether retarda-
tions of the phenomenon, to which I long ago
directed attention, indicate a regular recession
or change of the nodes (the points of intersec-
tion of the earth's orbit and the ring), or wheth-
er from unequal clustering or very dissimilar
distances of the little bodies from each other,
the zone is of such considerable breadth, that
the earth only passes through it in the course
of several days. The lunar system of Saturn
likewise shows us a group of most intimately
associated planetary bodies of amazing breadth.
In this group, the orbit of the 7th or outermost
satellite, is of so considerable a diameter, that
the earth, in her orbit round the sun, would
take three days to pass over a space of like ex-
tent. Now, if we suppose that the asteroids
are unequally distributed in the course of one
of the closed rings which we picture to our-
selves as forming the orbits of the periodic cur-
rents, that there are but a few thickly congre-
gated groups such as would give the idea of
continuous streams, we can understand where-
fore such brilliant phenomena as those of No-
vember 1799 and 1833 are extremely rare. The
acute Gibers was inclined to announce the re-
turn of the grand spectacle, in which shooting
stars mixed with fire-balls should fall like a
shower of snow, for the 12th-14th of Novem-
ber, 1867.

Hitherto the current of the November aste-
roids has only been visible over limited portions
of the earth's surface. It appeared, for exam-
ple, with great splendour in England in the
year 1837, as a meteoric shower ; whilst an
experienced and very attentive observer at
Braunsberg, in Prussia, saw nothing more than
a few scattered shooting stars in the course of
the same night, from seven o'clock in the
evening till sun-rise, the sky having continued
uninterruptedly clear the whole of the time.
Bessel concluded from this, " that a group of
the great ring which is occupied by these bod-
ies, of but limited extent, had approached the
earth over England, whilst districts to the east
passed through a relatively empty portion of
the ring"(*^). Should the idea of a regular pre-
cession or variation of the nodal lines, occa-
sioned by perturbations, acquire greater likeli-
hood, the discovery of older observations of the
F

phenomenon would become a matter of partic-
ular interest. The Chinese annals, in which,
beside the appearance of comets, there are also
notices of gi»at showers of shooting stars, go
back beyond the time of Tyrtaeus, or the second
Messenic war. They describe two streams oc-
curring in the month of March, one of which
is 687 years older than the commencement of
the Christian era. Edward Biot has already
remarked, that among the fifty-two appearan-
ces which he finds recorded in the Chinese an-
nals, the most frequently recurring were those
that fell near the date from the 20th to the 22d
of July (old style), which may very possibly be
the now advanced stream occurring about the
time of the feast of St. Lawrence(*^). If the
great fall of shooting stars which Bogulawski,
jun., finds recorded in Benessius de Horowic's
" Chronicon Ecclesiae Pragensis," as having
been seen in full day light on the 21st of Octo-
ber, 1366 (old style), corresponds with our pres-
ent November fall, the precession in the course
of 447 years informs us that this shoot-star
system (that is to say, its common point of
gravity), describes a retrograde course about
the sun. It also follows, from the views now
developed, that when seasons pass by in which
neither of the streams as yet observed — that,
namely, of November and that of August — is
seen in any part of the earth, the reason of
this lies either in the interruption of the ring —
in other words, in the occurrence of gaps or
vacancies between the clusters of asteroids
that follow each other — or, as Poisson will
have it, in the influence which the larger plan-
ets exercise upon the form and position of the
ring(*^).

The solid, heated, although not red-hot, mass-
es which are seen to fall to the earth from fire-
balls by night, from .small dark clouds by day,
accompanied with loud noises, the sky being
generally clear at the time, show, on the whole,
a very obvious similarity, in point of external
form, in the character of their crust and the
chemical composition of their principal ingre-
dients. This they have maintained through
centuries, and in every region of the earth in
which they have been collected. But so re-
markable and early asserted a physiognomical
equality in these dense meteoric masses is
subject to many individual exceptions How
different are the readily forged masses of iron
of Hradschina, in the district of Agram, or that
of the banks of the Sisim, in the government
of Jenesiesk, which have become celebrated
through Pallas, or those which I brought with
me from Mexico(*'), all of which contain 96 per
cent, of iron, from the aerolites of Siena, which
scarcely contain 2 per cent, of this metal, from
the earthy meteoric stone of Alais (Dep. du
Gard), which crumbles when put into water,
and from those of Jonzac and Juvenas, which,
without metallic iron, contain a mixture of
oryctognostically distinguishable, crystalline
and distinct constituents ! These diversities
have led to the division of the cosmical masses
into two classes — nickeliferous meteoric iron,
and fine or coarse grained meteoric stones.
Highly characteristic is the crust, though it be
but a few tenths of a line in thickness, often
shining like pitch, and occasionally vemed(").
So far as I know, it has only been found want-

43

SHOOTING STARS AND AEROLITES.

ing in the meteoric stone of Chantonnay, in
La Vendee, which, on the other hand — and
this is equally rare — exhibits pores and vesicu-
lar cavities like the meteoric ston^ of Juvenas.
In every instance the black crust is as sharply
separated from the clear gray mass, as is the
dark-coloured crust or varnish of the white
granite blocks which I brought from the cata-
racts of the Orinoko("), and which are also met
with by the side of other cataracts in different
quarters of the globe — those of the Nile, the
Congo, &c. It is impossible to produce any-
thing in the strongest heat of the porcelain
furnace which shall be so distinct from the un-
altered matter beneath, as is the crust of aero-
lites from their general mass. Some, indeed,
will have it that here and there indications of
penetration of fragments, as if by kneading,
appear ; but in general the condition of the
mass, the absence of flattening from the fall,
and the not very remarkable heat of the mete-
oric stone, when touched immediately after its
fall, indicate nothing like a state of fusion of
the interior during the rapid passage from the
limits of the atmosphere to the earth.

The chemical elements of which meteoric
masses consist, upon which Berzelius has
thrown so much light, are the same as those
which we encounter scattered through the
crust of the earth. They consist of eight met-
als (iron, nickel, cobalt, manganese, chrome,
copper, arsenic, and tin) ; five earths ; potash
and soda ; sulphur, phosporus, and carbon ; in
all, one-third of the entire number of simple
substances at present known. Despite this
similarity to the ultimate elements into which
inorganic bodies are chemically decomposable,
the appearance of meteoric masses has still
something that is generally strange to us ; the
kind of combination of the elements is unlike
all that our terrestrial mountain and rocky
masses exhibit. The native iron, which is met
with in almost the whole of them, gives them
a peculiar, but not therefore a lunar character ;
for, in other regions of space, in other plane-
tary bodies besides the moon, water may be
entirely wanting, and processes of oxidation
may be rare.

The cosmic gelatinous vesicles, the nostoc-
like organic masses, which have been attribu-
ted to shooting stars ever since the middle
ages, and the pyrites of Sterlitamak (westward
from the Ural Mountains), which have been
said to be composed of hail-stones in the inte-
rior, belong to the fables of meteorology(*2).
It is only the finely granular texture, only the
mixture of olivine, augite, and labrador spar("),
of some aerolites, of the doloritic-looking mass
of Juvenas in Ardeche, for example, that gives
them somewhat more of an indigenous charac-
ter, as G. Rose has shown. These aerolites,
indeed, contain crystalline substances exactly
similar to those of the crust of our Earth ; and
in Pallas's Siberian mass of meteoric iron, the
olivine is only distinguished by the absence
of nickel, which is there replaced by oxide of
tin(**). As meteoric olivine, like that of our
basalt, contains from 47 to 49 per cent, of mag-
nesia, and this earth, according to Berzelius,
generally constitutes one-half of the earthy in-
gredients of aerolites, we must not be astoi-
ished at the large quantity of silicate of mag-

nesia which we find in these cosmic masses.
If the aerolite of Juvenas contains separable
crystals of augite and labrador, it is at least
probable, from the numerical relations of the
ingredients, that the meteoric mass of Cha-
teau-Renard is a diorite composed of horn-
blende and albite, and those of Blansko and
Chantonnay of hornblende and labrador. The
indications of a telluric or atmospheric origin
of aerolites, which have been derived from the
oryctognostic resemblances just mentioned, do
not appear to me of any great weight. Where-
fore should not — and here I might refer to a
remarkable conversation between Newton and
Conduit at Kensington(**) — wherefore should
not the matter belonging to a particular cluster
of celestial bodies, to the same planetary sys-
tem, be for the major part the same 1 Why
should it not be so, when we feel at liberty to
surmise that these planets, like all larger and
smaller conglobated masses which revolve
about the sun, have separated from particular
and formerly much more widely-expanded sun-
atmospheres, as from vaporous rings, and
which originally held their courses round the
central bodyl We are not, I believe, more
authorized to regard nickel and iron, olivine
and pyroxene (augite), which we find in me-
teoric stones, as exclusively terrestrial, than I
should have been had I indicated the German
plants which I found beyond the Obi, as Euro-
pean species of the flora of northern Asia. If
the elementary matters in a group of planetary
bodies of various magnitudes be identical, why
should they not also, in harmony with their
several affinities, run into determinate combi-
nations— in the polar circle of Mars, into white
and brilliant snow and ice ; in other smaller
cosmic masses into mineral species that con-
tain crystalline, augite, olivine, and labrador 1
Even in the region of the merely Conjectu-
ral, the unbridled caprice that despises all in-
duction must not be suffered to control opin-
ion.

The extraordinary obscurations of the sun
which have occasionally taken place, during
which the stars became visible at mid-day (as
in the three days' darkness of the year 1547,
about the time of the fateful battle near Miihl-
berg), and which are not explicable on the sup-
position of a cloud of volcanic ashes, or of a
dense dry-fog, were ascribed by Kepler, at one
time, to a materia cometica, at another to a
black cloud, the product of sooty exhalations
from the sun's body. The observations of
shorter periods of darkness — of three and six
hours, in the years 1090 and 1203— Chladni
and Schnurrer have explained by the passage
of meteoric masses. And since the stream of
shooting stars from the direction of its orbit
has been regarded as forming a closed ilwg,
the epochs of these mysterious celestial phe-
nomena have been brought into a remarkable
connection with the regularly recurring show-
ers of shooting stars. Adolph Erman has,
with great acuteness, and after a careful analy-
sis of all the data collected up to the present
time, directed the attention of philosophers to
the coincidence of the conjunction with the
sun, as well of the August asteroids (7th of
February) as of the November asteroids (12th
of May), at the epoch which coincides with

SHOOTING STARS AND AEROLITES.

43

the popular belief in the celebrated cold days of
Mamertius, Pancratius, and Servatias(*®).

The Greek natural philosophers, little dis-
posed in general to observation, but incessant-
ly, inexhaustibly addicted to speculation on the
manifold import of half-seen truths, have left
views behind them on shooting stars and me-
teoric stones, several of which chime in most
remarkably with those at present so commonly
entertained of the cosmic nature of the phe-
nomenon. ♦' Shooting stars." says Plutarch(*^),
in the Life of Lysander, " according to the opin-
ion of some naturalists, are not excretions and
emanations of the ethereal fire, quenched in
the air immediately after their ignition ; nei-
ther are they any kindling and combustion of
the air, produced by those which have become
dissolved in quantities in the upper regions ;
they are rather a fall of celestial bodies, occa-
sioned by a certain abatement of the centrifu-
gal force, and the impulse of an irregular mo-
tion, and are cast down, not only upon the in-
habited earth, but also beyond it into the ocean,
on which account they are not then found."
Diogenes of Apollonia(*^) speaks still more
clearly on the subject. According to his view,
" along with the visible stars, others move
that are invisible, and therefore are unnamed.
These last frequently fall to the earth and are
extinguished, as was the case with the stony
star which descended in fire at Aegos Pota-
mos." The Apollonian, who also regards all
the other stars (the luminous ones) as pumice-
like bodies, probably founded his opinions of
the nature of shooting stars and meteoric
masses upon the doctrines of Anaxagoras, of
Clazomenae, who maintained that all the heav-
enly bodies were '• mineral masses, which the
fiery ether, in the power of its revolution, had
torn from the earth, had ignited and converted
into stars." In the Ionic school, according to
the statement of Diogenes of Apollonia, and as
it has come down to us, aerolites and the heav-
enly bodies were placed in one and the same
class ; both are alike terrestrial in their ori-
ginal production ; but only in the sense that
the earth, as the central body, had formerly(")
fashioned all around her ; in the same way as
our present ideas lead us to conceive that the
planets of a system arise from the extended
atmosphere of another central body — namely,
the sun. These views, consequently, are not
to be confounded with that which speaks fa-
miliarly of meteoric stones, as of telluric or at-
mospheric origin, nor yet with the extraordi-
nary conjecture of Aristotle, to the effect that
the enormous mass of Aegos Potamos had
been raised by a tempestuous wind.

The presumptuous skepticism which rejects
facts without caring to examine them, is, in
many respects, even more destructive than un-
critical credulity. Both interfere with rigour
of mvestigation. Although, for fifteen hundred
years, the annals of various nations have told
of the fall of stones from the sky— although sev-
eral instances of the circumstance are placed
beyond all question by the unimpeachable tes-
timony of eye-witnesses— ^although the Baetylia
formed an important part of the meteor-wor-
ship of the ancients, and the companions of
Cortes saw the aerolites in Cholula, which had
fallen upoji the neighbouring pyramid— although

Caliphs and Mongolian princes have had sword
blades forged from meteoric masses that had
but lately fallen, and men have even been kill-
ed by stones from heaven (a certain monk at
Crema, on the 4th September, 1511; another
monk in Milan, 1650 ; and two Sweedish sailors
on ship-board, 1674), so remarkable a cosmical
phenomenon remained almost unnoticed, and,
in its intimate relationship with the rest of the
planetary system, unappreciated, until Chladni,
who had already gained immortal honour in
physics by his discovery of phonic figures, di-
rected attention to the subject. But he who is
penetrated with the belief of this connection, if
he be susceptible of emotions of awe through
natural impressions, will be filled with solemn
thoughts in presence, not of the brilliant specta-
cles of the November and August phenomena
only, but even on the appearance of a solitary
shooting star. Here is a sudden exhibition of
movement in the midst of the realm of noctur-
nal peace. Life and motion occur at intervals
in the quiet lustre of the firmament. The track
of the falling star, gleaming with a palely lus-
tre, gives us a sensible representation of a path
long miles in length across the vault of heaven ;
the burning asteroid reminds us of the exist-
ence of universal space every where filled with
matter. When we compare the volume of the
innermost satellite of Saturn, or that of Ceres,
with the enormous volume of the Sun, all rela-
tion of great and small vanishes from the im-
agination. The extinction of the stars that
have suddenly blazed up in several parts of the
heavens, in Cassiopea, in Cygnus, and in Ophi-
ucus, leads us to admit the existence of dark
or non-luminous celestial bodies. Conglobed
into minor masses, the shooting-star asteroids
circulate about the sun, intersect the paths of
the great luminous planets, after the manner of
comets, and become ignited when they approach
or actually enter the outermost strata of our
atmosphere.

With all other planetary bodies, with the
whole of nature beyond the limits of our at-
mosphere, we are only brought into relation-
ship by means of light, of radiant heat, which
is scarcely to be separated from light("), and
the mysterious force of attraction which dis-
tant masses exert upon our earth, our ocean,
and our atmosphere, according to the quantity
of their material parts. We recognize a totally
different kind of cosmic, and most peculiarly
material relationship, in the fall of shooting-
stars and meteoric stones, when we regard
them as planetary asteroids. These are no
longer bodies, which, through the mere excite-
ment of pulses, influence us from a distance by
their light or their heat, or which move and are
moved by attraction ; they are material bodies,
which have come from the realms of space into
our atmosphere, and remain with our earth.
Through the fall of a meteoric stone, we ex-
perience the only possible contact of aught that
does not belong to our planet. Accustomed to
know all that is non-telluric solely through
measurement, through calculation, through in-
tellectual induction, we are amazed when we
touch, weigh, and subject to analysis a mass
that has belonged to the world beyond us. Thus
does the reflecting, spiritualized excitement of
the feeUngs work upon imagination, in circum-

44

THE ZODIACAL LIGHT.

stances where vulgar sense sees nothing but dy-
ing sparks in the clear vault of heaven, and in the
black stone that falls from the crackling cloud
the crude product ofsome vt^ild force of nature.
If the crowd of shooting asteroids, upon
which we have paused so long with pleasure,
be assimilated in some respects, in their small
masses and in the variety of their orbits, with
comets, they are still essentially distinguish-
ed from these bodies in this — that we first be-
come aware of their existence almost in the
moment of their destruction, when fettered by
the earth they become luminous, and ignite.
But to embrace everytJiing that belongs to our
solar system, which has now become so com-
plex, so rich in variety of forms, by the discov-
ery of the telescopic planets, of the inner com-
ets of short period, and the meteoric asteroids,
we have still to speak particularly of the ring
of Zodiacal Light, to which we have already
alluded incidentally oftener than once. He who
has lived for years in the zone of the palms,
retains a delightful recollection of the mild ra-
diance with which the zodiacal light, rising like
a pyramid from the horizon, illumines a portion
of the unvarying length of the tropical night.
I have seen it occasionally more intensely lu-
minous than the milky way in Saggitarius ; and
that not only in the thin and dry atmosphere of
the summits of the Andes, at the height of
twelve or fourteen thousand feet above the lev-
el of the sea, but also in the boundless grassy
plains (Llanos) of Venezuel-a, as well as on the
coasts of the ocean under the ever-serene sky
of Cumana. Of most peculiar beauty was the
phenomenon, when small fleecy clouds appear-
ed projected upon the light, and stood out pic-
turesquely from the luminous back-ground. A
leaf of my journal, during the sea voyage from
Lima to the western coast of Mexico, preserves
the memorial of this air-picture : " For the last
three or four nights (between 10° and 14° N.
lat.) I see the zodiacal light with a splendour
such as I have never observed before. In this
part of the Pacific, judging from the brilliancy
of the stars, and the distinctness of the nebulae,
the transparency of the air is wonderfully great.
From the 14th to the 19th of March, very reg-
ularly for three-quarters of an hour after the
disc of the sun has dipped into the sea, there is
no trace of the zodiacal light, although it is by
this time completely dark ; but, an hour after
sun-set, it suddenly becomes visible, of great
brilliancy, between Aldebaran and the Pleiades ;
and on the 18th of March having an altitude of
39° 5'. Long narrow stripes of cloud show
themselves, scattered over the beautiful blue,
and deep on the horizon in front of a kind of
yellow screen. The higher clouds are play-
ing from time to time with variegated tints. It
seems as if the sun were setting for the second
time. On this side of the vault of heaven, the
brilliancy of the night appears to be increased,
almost as it is in the first quarter of the moon.
Towards ten o'clock, the zodiacal light, in this
part of the Pacific, was usually extremely faint ;
about midnight I could merely perceive a trace
of it. On the 16th of March, when the phe-
nomenon presented itself in its greatest splen-
dour, there was a counter-blush of mild light
apparent in the east." In our misty northern
temperate zone, as it is called, the zodiacal

light is only to be distinctly seen in the early
spring, after the evening twilight, in the west-
ern, and towards the end of autumn before the
morning twilight, in the eastern horizon.

It is difficult to comprehend how a natural
phenomenon, so remarkable as the zodiacal
light, should only first have attracted the atten-
tion of natural philosophers and astronomers
about the middle of the 17th century, and how
it could have escaped the observant Arabians
in Ancient Bactria, on the Euphrates, and in
the south of Spain. The tardy observation of
the nebulae in Andromeda and Orion, first de-
scribed by Simon Marius and Huygens, excites
almost equal astonishment. The first distinct
description of the zodiacal light is contained in
Childrey's Britannia Baconica("), of the year
1661 ; the first observation upon it may have
been made two or three years earlier ; but
Dominic Cassini has the indisputable merit of
having, in the spring of 1683, investigated the
phenomenon in all its relations in space. The
luminous appearance which he observed in
1668, at Bologna, and which was seen at the
same time in Persia by the celebrated travel-
ler, Chardin, (the court- astrologers of Ispahan
called this light, which they had never seen
before, nyzek, or little lance,) was not, as has
been frequently said("), the zodiacal light, but
the monstrous tail of a comet, whose head was
hidden amidst the vapours of the horizon, and
which, in point of length and appearance, pre-
sented many points of resemblance to the great
comet of 1843. It might be maintained, with
no slight show of probability, that the remark-
able light, rising pyramidally from the earth,
which was seen in the eastern sky for forty
nights in succession, on the lofty plateau of
Mexico in 1509, was the zodiacal light. I find
this phenomenon mentioned in an ancient Az-
tekan manuscript (Codex Telleriano-Remensis)
of the Royal Library at Paris(^3).

The Zodiacal Light, of primeval antiquity,
doubtless, though first discovered in Europe by
Childery and Cassini, is not the luminous at-
mosphere of the sun itself; for this, from me-
chanical laws, cannot be more oblate than in
the ratio of two to three, and not more dilated
than 9-20ths of Mercury's distance. The same
laws determine that, in the case of a revolving
planetary body, the height or distance of the
extreme limits of its* atmosphere — the point,
namely, where gravity and the centrifugal force
are in equilibrium — is that alone in which a
satellite can revolve around this in the same
time as the primary rotates upon its axis(").
Such a limitation of the sun's atmosphere in its
present concentrated state, comes to be more
particularly remarkable when we compare the
central body of our system with the nucleus of
other nebulous stars. Herschel discovered
many in which the semidiameter of the burr
which surrounds the star appears under an an-
gle of 150". Assuming a parallax which does
not quite reach 1", we find the outermost neb-
ulous layer of such a star 150 times farther
from its centre than the earth is distant from
the sun. Were the nebulous star in the place
of our sun, consequently, its atmosphere would
not merely include the orbit of Uranus, but
would extend 8 times beyond it(").

With the narrow limits of the sun's atmo-

TRANSLATION OF THE SUN IN SPACE.

45

sphere now indicated, there is great probability
in the hypothesis which assumes the existence
of an extremely oblate ring of nebulous or va-
porous matter revolving freely in space be-
tween the orbits of Venus and Mars, as the ma-
terial cause of the zodiacal light("). Mean-
time, of its proper material dimensions, of its
increment by emanations from the tails of myr-
iads of comets which approach near to the
sunC^), of the singular variability of its extent
— for it seems at times not to extend beyond the
orbit of the earth, and lastly, of its very prob-
able close connection with the denser world-
ether in the vicinity of the sun— nothing cer-
tain can be concluded. The vaporiform par-
ticles of which the ring consists, and which
circulate about the sun in conformity with plan-
etary laws, may either be self-luminous, or
lighted by the sun. Even a terrestrial haze or
fog (and the fact is very remarkable) appeared
at the time of the new moon (1743), which at
midnight was so phosphorescent that objects
at the distance of 600 feet could be plainly dis-
tinguished by its light^^). In the tropical cli-
mate of South America, the variable strength
of light of the zodiacal gleam struck me at
times with amazement. As I there passed the
beautiful nights in the open air, on the banks
of rivers and in the grassy plains (Llanos) for
several months together, I had opportunities of
observing the phenomenon with care. When
the zodiacal light was at its very brightest, it
sometimes happened that but a few minutes
afterwards it became notably weakened, and
then it suddenly gleamed up again with its
former brilliancy. In particular instances, I
believed that I remarked — not any thing of a
ruddy tinge, or an inferior arched obscuration,
or an emission of sparks, such as Mairan de-
scribes, but a kind of unsteadiness and flicker-
ing of the light. Is it that there are ^ny pro-
cesses going on in the vaporous ring itself 1 or
is it not more likely that, though I could detect
no change, by the meteorolojgical instruments,
in the temperature and moistness of the re-
gions of the atmosphere immediately above the
ground, and though small stars of the fifth and
sixth magnitudes appeared to shine with undi-
minished strength of light, that in the superior
strata of the atmosphere condensations were
proceeding which modified the transparency, or
rather the reflection of the light, in a peculiar
and, to us, unknown manner 1 For the as-
sumption of such meteorological processes on
the limits of our atmosphere, the "explosions
and pulsations" observed by the acute 01-
bers(^^), " which, in the course of a few sec-
onds, went trembling through the whole of a
comet's tail, with the effect now of lengthening,
now of abridging it by several degrees," appear
to vouch. " As the several parts of the mill-
ions-of-miles-long tail are at very different dis-
tances from the earth, the laws of the velocity
and propagation of light do not permit us to
suppose that actual alterations in a body filling
an extent of space so vast, could be perceived
by us in such short intervals of time." These
considerations by no means exclude the reality
of varying emanations around the condensed
nuclear envelopes of a comet, the reality of
suddenly supervening brightenings of the zodi-
acal light, through internal molecular move-

ments, through alternately augmented or di-
minished reflections of light by the matter of
the luminous ring; they should only make us
careful to distinguish between them and all that
belongs to the celestial ether — to universal
space itself, or to the aerial strata composing
the atmosphere through which we see. What
in other respects takes place in the outer limits
of our atmosphere — the subject of great diver-
sity of opinion — is, as well-observed facts in-
dicate, by no means to be completely or satis-
factorily explained. The wonderful lightness
of many whole nights of the year 1831, in which
small print could be read at midnight in Italy
and the north of Germany, is in obvious con-
tradiction with all that the latest and ablest ob-
servations on the crepuscular theory, and the
height of our atmosphere, make known(").
Luminous phenomena are dependent on con-
ditions that are yet unexplored, the unstable-
ness of which, within the limits of the twilight,
as well as in connection with the zodiacal
light, strike us with astonishment.

Thus far we have considered what belongs
to our sun, and the world of formations that is
ruled by him — the primary and secondary plan-
ets, comets of shorter and longer periods of
revolution, meteoric asteroids which move sin-
gly in closed rings, or in multitudes like a
stream ; finally, a luminous nebulous ring which
circles round the sun near to the orbit of the
earth, and which from its position may remain
with its name of zodiacal light. Every where
the Law of Return prevails in the motions,
how different soever the measure of the pro-
jectile velocity and the quantity of conglobated
material parts ; the asteroids alone, which fall
from space into our atmosphere, are interrupted
in their planetary round, and united to a larger
planet. In the solar system, whose limits the
attractive force of the central body determines,
comets, at the distance of forty-four times tho
distance of Uranus from the sun, are compelled
to return in their elliptical orbits ; in these
comets themselves, indeed, whose nuclei, from
the smallness of the masses they comprise,
present themselves to us in the guise of flitting
cosmic clouds, these nuclei, nevertheless, bind,
by their attractive force, the very outermost
particles of the tail that is streaming away at
the distance of millions of miles from them.
The central forces, therefore, are the forming,
the fashioning, and even the preserving forces
of a system.

Our sun, in its relations to all the returning
or circulating, greater or smaller, denser or al-
most vaporiform bodies that belong to it, may
be regarded as at rest ; yet does it revolve
around the common centre of gravity of the
whole system, which, however, still falls with-
in itself; which, in other words, despite the
variable position of the planets, still remains
attached to its material bounds. Altogether
diflferent from this phenomenon, is the motion
of translation of the sun— the progressive mo-
tion of the centre of gravity of the entire solar
system in Universal space. This goes on with
such velocity, that, according to Bessel, the
relative motions of the sun and of the 61st star
in Cygnus do not amount to less than 834,000
geographical miles in a day("). This change

46

MOTIONS OF THE DOUBLE STARS.

of place of the whole solar system would re-
main unknown to us, were it not that the won-
derful perfection of modern astronomical instru-
ments for taking measurements, and the ad-
vances of the astronomy of observation, ren-
der our progress obvious towards distant stars
as towards objects on a coast apparently in
motion. The proper motion of the 61st star in
the constellation of the Swan, for example, is
so considerable, that in the course of 700 years
it will have amounted to a whole degree.

The measure or quantity of alteration in the
heaven of the fixed stars — of alteration in the
relative positions of the self-luminous stars to
one another — can be determined with more of
certainty than the phenomenon itself can be
genetically explained. Even after we have al-
lowed for all that belongs to the precession of
the equinoxes and the nutation of the earth's ax-
is, as consequences of the influence of the sun
and moon upon the spheroidal figure of our plan-
et, to the propagation or aberration of light, and
to the parallax produced by diametrically oppo-
site positions of the earth in its orbit round the
sun — when a correction has been made for
each and all of these particulars, there is al-
ways a quantity in the remaining annual mo-
tion of the fixed stars, which is the conse-
quence of the translation of the whole solar
system in space, and which is the consequence
of the proper and actual motion of the stars
themselves. The difficult numerical separa-
tion of these two elements, of the proper from
the apparent motion, has been made possible
by the careful specification of the directions in
which the motions of the several stars take
place, and by the reflection that, were all the
other stars absolutely at rest, they would ap-
pear to recede perspectively from the point to-
wards which the sun was moving in his course.
The final result of the investigation, which the
calculus of probabilities confirms, is this : that
both the stars and our sun change their place in
the Universe. From the admirable researches
of Argelander("), who in Abo extended and ma-
terially improved upon the labours begun by the
elder Herschel and Prevost, it appears that the
sun is in motion towards the constellation of
Hercules, very probably towards a point in this
constellation, which lies in a combination of
537 stars (for the equinox of 1792-5) in 257°
49' Right Ascension ; -f 28° 49'-7 Declination.
In this class of investigations it is always matter
of great difficulty to separate the absolute from
the relative motion, and to determine what be-
longs to the solar system in particular and alone.

If the non-perspective proper motions of the
stars be considered, many of them appear group-
wise opposed in their directions ; and the data
hitherto collected make it at least not necessary
to suppose that all the parts of our astral sys-
tem, or the whole of the star-islands which fill
the universe, are in motion about any great,
unknown, luminous, or non-luminous central
mass. The longing to reach the last or high-
est fundamental cause, indeed, renders the re-
flecting faculty of man as well as his fancy dis-
posed to adopt such a supposition. The Stagi-
rite himself has said — "All that is in motion
refers us to a Mover, and it were but an endless
adjournment of causes were there not a prima-
ry immoveable Mover"(").

The manifold changes of place exhibited by
the fixed stars in groups, not parallactic mo-
tions, dependent on changes in the position of
the observer, but actual and ceaseless motions
in universal space, reveal to us in the most
incontrovertible manner, through a particular
class of phenomena, namely the motions of the
double stars, and the measure of their slower
or more rapid motions in different parts of their
elliptical orbits, the empire of the laws of grav-
itation beyond the limits of our solar system,
in the remotest regions of creation. The curi-
osity that is inherent in the nature of man
needs not any longer to seek satisfaction upon
this field of inquiry in gratuitous assumptions,
in the limitless ideal-world of analogies. By
the progress of the astronomy of observation
and calculation, it stands at length even here
upon stable ground. It is not so much the
numbers of the double and multiple stars that
have been discovered (2,800 to the year 1837 !)
circulating about a centre of gravity lying be-
yond the confines of either or any of them, that
excites our amazement ; it is the extension of
our knowledge of the fundamental force of the
whole material world, the indications of the
universal dominion of mass-attraction, that ar-
rest us, and that belong to the most brilliant
discoveries of our age. The time of revolution
of double stars of different colours presents the
greatest imaginable diversity ; it extends from
a period of 43 years, as in t} Coronae, to one of
several thousands, as in 66 Ceti, 38 Gemino-
rum, and 100 Piscis. Since Herschel's meas-
urements in 1782, the nearest leader in the tri-
ple system of ^ Cancri, has now accomplished
more than a complete revolution. By a skilful
combination of observations of altered distan-
ces and angles of positionC*), the elements of
the orbits of more than one of the double stars
have b^en discovered — nay, conclusions as to
the absolute distance of double stars from the
earth, and comparisons of their masses with
the mass of the sun, have even been made.
But whether here, and in our solar system, the
quantity of matter is the sole measure of the
force of attraction, or whether specific attrac-
tions, not in proportion to the mass, are at the
same time efficient, as Bessel first showed, is
a question the solution of which it remains with
late posterity to accomplish(").

If we compare our sun, with the other so-
called fixed stars in the Astral system to which
we belong, with other self-luminous suns, there-
fore, we discover, in connection with several
of them at least, ways opened up, which ena-
ble us to approximate, within certain extreme
limits, to a knowledge of their distance, of
their volume, of their mass, and of ihe rapidity
with which they change their places. If we
assume the distance of Uranus from the sun,
at 19 of the distances of the earth from the sun
then is the central body of our planetary sys-
tem 11,900 Uranus distances from the star a
Centauri, almost 31,300 of these distances
from 61 Cygni, and 41,600 of the same meas-
ures from a Lyr». The comparison of the
volume of the "sun with the volume of fixed
stars of the first magnitude, depends on an ex-
tremely uncertain optical element ; viz., the
apparent diameter of the fixed stars. If, with
Herschel, we assume the apparent diameter of

THE MILKY WAYS OF STARS AND NEBUL.G.

Arcturus at but one-tenth part of a second,
the actual diameter of this star would still
come out eleven times greater than that of our
sun(^«). The distance of the star 61 Cygni, for
the discovery of which we are indebted to Bes-
sel, has led us approximatively to a knowledge
of the quantity of material particles, which, as
a double star, it contains. Although the por-
tion of the apparent path which has been
passed through since Bradley's observations,
is not yet sufficiently great to enable us to con-
clude with perfect certainty upon the true path,
and the semi-axis major of the same, it has still
become matter of probability to the great as-
tronomer of Konigsberg, '* that the mass of the
double star in question is not materially either
less or more than half the mass of our sun(")."
This is the conclusion from actual measure-
ment. Analogies which are derived from the
greater masses of the moon-attended planets
of our solar system, and from the fact that
Struve finds six times as many double stars
among the brighter fixed stars as among the
telescopic ones, have led other astronomers to
conjecture that the mass of the greater num-
ber of the twin-stars is in the mean greater
than that of the sun(^^). General results, how-
ever, cannot be looked for in this direction for
long years to come. With reference to proper
motion in space, our sun, according to Arge-
lander, belongs to the class of fixed stars which
are in rapid motion.

The view of the heavens inlaid with stars,
the relative position of the stars and nebulous
spots, as also the distribution of their luminous
masses,' the charms of the landscape, if I may
here make use of the expression, presented by
the firmament at large, will depend, in the
course of millenniums, relatively on the proper
actual motions of the stars and nebulae, on the
translation of our solar system in space, on the
bursting out of new stars, and on the disap-
pearance, or sudden diminution in the inten-
sity of light in old stars; finally, and especially,
on the alterations which the axis of the earth
experiences through the attraction of the sun
and moon. The beautiful stars of the Centaur
and the southern Cross will one day become
visible in these northern latitudes, whilst oth-
er stars and constellations, Sirius and Orion's
belt, will have sunk. The stationary north
pole will be indicated in succession by stars in
Cepheus ((3 and c), and the Swan (d), until,
after the lapse of 12,000 years, Vega in Lyra
will appear as the most brilliant of all the pos-
sible polar stars. These statements serve to
bring sensibly before us the vastness of the
motions which in infinitely small divisions of
time go on incessantly like an eternal clock —
the timepiece of the Universe. If we imagine,
as in a vision of the fancy, the acuteness of
oar senses preternaturally sharpened, even to
the extreme limit of telescopic vision, and in-
cidents compressed into a day or an hour,
which are separated by vast intervals of time,
everything like rest in spacial existence will
forthwith disappear. We shall find the innu-
merable host of the fixed stars commoved in
groups in different directions ; nebulae drawing
hither and thither, like cosmic clouds ; the
milky way breaking up in particular parts, and
Its veil rent ; motion in every point of the

vault of heaven, as on the surface of the earth,
in the germinating, leaf-pushing, flower-unfold-
ing organisms of its vegetable covering. The
celebrated Spanish botanist, Cavanilles, first
conceived the thought of" seeing grass grow,"
by setting the horizontal threads of a microme-
ter attached to a powerful telescope, at one
time upon the tip of the shoot of a Bambusa,
at another upon that of the fast-growing flow-
ering stem of an American aloe (Agave Ameri-
cana), precisely as the astronomer brings a cul-
minating star upon the cross wires of his in-
strument. In the aggregate life of nature, or-
ganic as well as sidereal, Being, Maintaining,
and Becoming, are alike associated with motion.

The disruption of the milky way, to which I
have alluded above, seems to require a more
particular explanation in this place. William
Herschel, our safe and admirable guide in these
regions of space, discovered, by means of his
star-gau^ings, that the telescopic breadth of
the milky way is six or seven degrees greater
than it appears upon our maps of the heavens,
and than the star-glimmer indicates it to the un-
assisted eye^^'). The two brilliant nodes in which
both branches of the milky zone unite, in the
regions of Cepheus and Cassiopea, as in those
of Scorpio and Sagittariu^, appear to exercise a
powerful attraction upon the neighbouring
stars ; betwixt fi and y Cygni, however, in the
most brilliant region, of 333,000 stars that lie
in 5° of latitude, one-half draw towards one
side, the other half towards the opposite side.
Here Herschel suspects that the stratum breaks
up(^°). The number of the distinguishable tel-
escopic stars of the milky way — stars that are
broken by no nebulae — has been estimated at
eighteen millions. In order, I will not say to
give any idea of the magnitude of this number,
but to contrast it with something analogous, I
will remind the reader, that of stars between
the 1st and 6th magnitude, that are visible to
the naked eye, there are but some 8,000 scat-
tered over the whole face of the heavens. In
the barren astonishment, excited by vastness
of number and of space, without reference to
the spiritual nature or the faculty of perception
inherent in man, extremes in respect of dimen-
sions of the things that exist in space, likewise
me^ and contrast — the heavenly bodies with
the smallest forms of animal life : a cubic inch
of the tripoli of Bilin, contains, according to
Ehrenberg, 40,000 millions of the siliceous cov-
erings of the Galionellse !

To the milky way of stars, to which, accord-
ing to Argelander's acute observation, many
of the bright stars of the firmament appear re-
markably to approximate, there is a milky way
of nebulae opposed almost at right angles. The
former, according to Sir John Herschel's views,
forms a ring, a detached and somewhat remote
girdle, from the lenticular star-island similai
to the ring of Saturn. Our planetary system
lies excentrically, nearer to the region of the
Cross than to the diametrically opposite point
of Cassiopea("). The form of our astral stra-
tum, and the parted ring of our milky way, pre-
sent themselves reflected with wonderful simi-
larity in a nebula discovered by Messier, in 1774,
but imperfectly seen by him(«2) The milky
way of the nebulae does not properly belong to
our astral svstem ; it surrounds this, without

48

PROPAGATION OF LIGFIT.

having any physical connection with it, at a
vast distance, and passes nearly in the form
of a great circle through the thick nebulosity
of Virgo (particularly in the northern wing),
through the Coma Berenices, the Great Bear,
the girdle of Andromeda, and the Northern
Fish. It probably intersects the starry milky
way in Cassiopea, and connects its poles, which
are poor in stars, made desolate by cluster-
forming forces, at the place where the stratum
of stars is of least thickness in space(^^).

It follows, from these considerations, that
whilst our cluster of stars bears traces, in its
diverging branches, of greater transformations
effected in the lapse of time, and strives, through
secondary points of attraction, to resolve and
decompose itself, it is surrounded by two rings,
one vastly remote, made up of nebulae, and one
nearer, consisting of stars. The latter ring,
which forms our milky way, is a mixture of
unnebulous stars, on an average from the 10th
to the 11th magnitude('*), but, severally ob-
served, of very dissimilar magnitudes, whilst
isolated clusters of stars have almost always
the character of sameness.

Wherever the vault of heaven is searched
with powerful space-penetrating telescopes,
stars, though perchance telescopic only, and
from the twentieth to the twenty-fourth in or-
der, or luminous nebulae, are discovered. Num-
bers of these nebulae will probably resolve
themselves into stars, when they come to be
examined with yet more powerful instruments.
Our retina receives the impression of single or
of thickly aggregated luminous points ; whence,
as Arago has lately shown, totally different
photometrical relations of the sensibility to
light result(*'). The cosmic nebulosity, form-
less or fashioned, generally diffused, producing
heat by condensation, probably modifies the
transparency of space, and lessens the equal
intensity of luminousness which, according to
Halley and others, must result, were every
point of the vault of heave'n beset with an end-
less succession of stars in the direction of its
depthC^). The assumption of any such con-
tinuous inlaying of stars contradicts observa-
tion ; which, in fact, shows us vast starless
regions — openings in heaven, as William Her-
schel calls them — one in Scorpio, four decrees
in breadth, and another in the loin of Ophiucus ;
in the vicinity of both of which, and close to
their edges, we discover resolvable nebulae.
That which is situated on the western edge of
the opening in Scorpio, is one of the richest
and most thickly set clusters of small stars
that ornament the heavens. Herschel himself
ascribes the openings, the starless regions in
the sky, to the attraction and cluster-forming
force of these marginal groups(^'). " They are
portions of our star-stratum," says he, in the
fine liveliness of his style, " which have suffer-
ed great desolations from time." If we picture
to ourselves the telescopic stars that lie one
behind another, as forming a starry can'opy in-
vesting the whole of the visible vault of heaven,
then, I believe, are those starless regions of
the Scorpion and Serpent-bearer, to be regard-
ed as tubes, through which we see into the
farthest regions of space. The layers of the
canopy are interrupted ; other stars, indeed,
may lie within the gaps, but they are unattain-

able to our instruments. The sight of fiery
meteors had already led the ancients to the
idea of clefts and chasms in the canopy of
heaven ; but these were regarded as passing
or temporary only. Instead of being dark, they
were luminous and fiery, by reason of the
translucent igneous ether that lay behind
them('^). Derham, and even Huyghens, appear
not indisposed to explain the mild light of neb-
ulae on some such grounds(*').

When we compare the brilliant, and on an
average certainly nearer, stars of the first mag-
nitude, with the telescopic or resolvable nebu-
lae, and contrast the nebulous stars with the
wholly unresolvable nebulae (with the one in
Andromeda, for example), or even with the so-
called planetary nebulae, in the contemplation,
of distances so different, plunged, as it were,
in the boundlessness of space, we have a fact
revealed to us by the world of phenomena, and
the reality, which, in causal connection with it,
always forms its substrate — the fact of The
Propagation of Light. The rate of this prop-
agation, according to Struve's latest research-
es, is 41,518 geographical [166,072 English]
miles in a second ; nearly a million times
greater, therefore, than the rate of sound.
From what we know through the measure-
ments of Maclear, Bessel, and Struve, of the
parallaxes and distances of three fixed stars of
very unequal magnitudes — aCentauri,6lCygni,
and a Lyrae — a ray of light requires 3 years,
9i years, and 12 years, to reach us from these
celestial bodies severally. In the short but
remarkable period from 1572 to 1604, from Cor-
nelius Gemma and Tycho to Kepler, three new
stars blazed suddenly forth in Cassiopea, in
Cygnus, and in the foot of Ophiucus. The
same phenomenon showed itself in 1570 in the
constellation of the Fox ; but here it recurred
several times. In the very latest times, since
1837, Sir John Herschel during his sojourn at
the C!ape of Good Hope observed the star ij of
the constellation Argo increase in brilliancy
from a star of the second magnitude to one of
the first(50). Such incidents in the universe
belong, however, in their historical reality, to
other times than those in which the phenome-
na of light notify their commencement to the
inhabitants of the earth ; they are the voices of
the past which reach us. It has been well
said, that with our mighty telescopes we pen-
etrate at once into space and into time. We
measure the former by the latter, the latter by
the former ; an hour of travel for the ray of
light is one hundred and forty-eight millions of
geographical miles passed through. Whilst the
dimensions of the universe are expressed in
the theogony of Hesiod by the fall of heavy
bodies — " the brazen anvil falls in no more than
nine days and nine nights from heaven to
earth" — Herschel, the Father ("), believed
" that the light of the farthest nebulae, which
his forty-feet reflector showed him, took about
two millions of years to reach the earth."
Much, therefore, has long disappeared, much
has already been otherwise arranged, before it
becomes visible to us. The aspect of the starry
heavens presents us with evidences of diversity
in point of time ; and diminish as we will the
millions or even thousands of years which
serve us as measures for the distance of the

TERRESTRIAL SPHERE.

tlTiresolvable nebulae with their soft lustre, and
of the resolvable nebulee with their twilight
gleamings, bring them as close to us as we
may, it still remains more than probable, from
the knowledge we have of the velocity of light,
that the light of the remote celestial bodies
offers the oldest sensible evidence of the exist-
ence of matter. So rises reflecting man, from
his stance on simple premises, to solemn and
noble views of natural formations to the deep
fields of space, where flooded with everlasting
light—

" Myriads of worlds spring up like the grass of night."(92)

From the region of celestial formations, from
the children of Uranos, we now descend to the
narrower domain of terrestrial forces, to the
children of Gaea. A mysterious band surrounds
and binds together both classes of phenomena.
In the import of the old Titanian Mythus ("),
all the powers of the universal life, the whole
mighty order of nature, is connected with the
co-operation of the heavens and the earth.
And, indeed, if the terrestrial ball, like all the
other planets, belongs, in virtue of its origin,
to the central body, the sun, and to its atmo-
sphere, once parted into nebulous rings, an in-
tercourse is still kept up, by means of light and
radiant heat, with this neighbouring sun, as
with all the farther suns that sparkle in the
firmament. The diversity of the mass of these
influences must not restrain the physical as-
tronomer from referring in a natural picture to
the connection and the dominion of common
and similar forces. A small fraction of the
terrestrial heat belongs to that of the universal
space through which our planetary system pur-
sues its way, and which, the product of all the
light-radiant stars, is nearly of the mean tem-
perature of our icy circumpolar regions, accord-
ing to Fourier. But what it is that excites the
light of the sun more powerfully in the atmo-
sphere and upper strata of the earth — how,
producing heat, it gives rise to electrical and
magnetical currents — how it magically kindles
and beneficially feeds the flame of life in the
organic forms that people the earth — all this
will form the subject of our considerations by
and by.

Whilst we here apply ourselves exclusively
to the telluric sphere of nature, then, we shall
first take a glance at the relative proportions
of the Solid and the Fluid, at the figure of the
earth, its mean density, and the partial distri-
bution of this density in the interior of the
planet ; at the contained heat, and the mag-
netic charge of the earth. These relations in
respect of space, and these forces inherent in
matter, lead to the reaction of the interior upon
the exterior of our earth ; they lead through
the special consideration of an universally dif-
fused natural force — sub-terrestrial heat — to
the not always merely dynamic phenomena of
earthquakes in circles of concussion of various
extent, to the outbreak of hot springs, and the
mightier operations of volcanic processes. The
crust of the earth shaken from below, now in
pulses, suddenly and violently, now smoothly
and continuously, and therefore scarcely per-
ceptibly, alters in the course of centuries the
relations in point of elevation between the Dry
and the surface-level of the Fluid ; nay, the
form of the bed of the ocean itself. There are,
G

at the same time, either temporary cracks, or
more permanent openings formed, through
which the interior of the earth comes into re-
lationship with the atmosphere. Welling up
from unknown depths, molten masses flow in
narrow streams along the slopes of the mount-
ains, here precipitously, there slowly, gently,
until the fiery spring runs dry, and the lava,
emitting vapours, solidifies beneath a crust
which it has formed for itself New rocky
masses then arise before our eyes, whilst older
ones, already formed by Plutonic forces, suffer
change, rarely through immediate contact, more
frequently from their vicinity to heat-radiating
centres or masses. In situations where there
is no eruption, crystalline particles are still dis-
placed, and then combined into denser textures.

The waters present us with formations of a
totally different nature : aggregations of the re-
mains of plants and animals ; earthy, creta-
ceous, and clayey deposits ; conglomerates of
finely pulverized mountain species, overlaid by
layers of siliceous-shelled infusoria, and bone-
containing drift, the resting place of the re-
mains of animals that peopled a former world.
All that we see engendered in such variety of
ways beneath our eyes, and arranged in layers,
all that we observe so variously cast down,
and bent, and raised again, under the influence
of opposing pressure and volcanic force, leads
the reflective observer, who yields himself to
the guidance of simple analogies, to the com-
parison of the Present with times that have
long gone by. Through combination of actual
phenomena, through ideal amplification in ref-
erence to the extent as well as to the mass of
the forces in operation, we reach at length the
long-desired, the dimly-imagined, but first, in
the course of the last century, firmly-founded
domain of geognosy.

It has been acutely observed, that, " with all
our looking through powerful telescopes, we
actually know more of the interior of other
planets than of their exterior — the moon, per-
haps, excepted." They have been weighed,
and their volumes have been measured ; their
masses and their densities are known, in either
case — thanks to the progress of the astronomy
of observation and calculation — with still in-
creasing numerical certainty. Over their phys-
ical constitution there hangs a deep obscurity.
It is only in our own earth that immediate vi-
cinity brings us into contact with the various
elements of organic and inorganic creation.
Here the garner of matter, in its multifarious
diversity, in its endlessness of admixture and
modification and change, in the ever-varying
play of forces evoked, presents the spirit with
its proper food : the joys of investigation, the
unbounded field of observation, which, cultiva-
ting and strengthening the faculty of thought,
gives to the intellectual sphere of man's exist-
ence a portion of its grandeur, of its sublimity.
The world of sensible phenomena reflects it-
self in the deeps of the ideal world : the abun-
dance of nature, the mass of things discernible,
passes gradually into the domain of knowledge
approved by reason.

And here, again, I touch upon an advantage
to which I have already alluded several times
—the advantage of that knowledge which has
a home origin, and of which the possibility is

50

TERRESTRIAL SPHERE.

most intimately connected with our earthly ex-
istence. The description of the heavens, from
the far-gleaming nebulous stars (with their
suns) down to the central body of our own
system, we found limited to such general con-
ceptions as volume and quantity of matter. No
vital movement is there revealed to our senses.
It is only after resemblances, often after fanci-
ful combinations, that we arrive at conjectures
as to the specific nature of matters of different
kinds, as to its [presence or] absence in this
or in that planetary body. The heterogeneous-
ness of matter, its chemical diversity, and the
regular forms into which its particles arrange
themselves, as crystals and granules ; its re-
lations to the penetrating deflected or decom-
pounded waves of light, to radiating, transmit-
ted, or polarized heat, to the brilliant, or invis-
ible, but not on that account less powerful,
phenomena of electro-magnetism — all this vast
treasury of physical knowledge, which so ex-
alts our views of nature, we owe to the sur-
face of the planet we inhabit, and to the solid
rather than the fluid element in its constitution.
How this knowledge of natural things and nat-
ural forces, how the measureless variety of ob-
jective perceptions, calls forth the intellectual
activity of our kind, and hastens our progress
in improvement, has been already observed
upon above. These relations as little require
farther development in this place, as the en-
chainment of the causes of that material force
which the control of a portion of the elements
has given to particular nations.

If it was imperative on me to direct atten-
tion to the difference which exists betwixt the
nature of our telluric knowledge, and our knowl-
edge of heavenly space and its contents, so is
it also necessary for me to indicate the narrow-
ness of the field from which the whole of our
knowledge of the heterogeneousness of matter
is derived. This field is somewhat inappropri-
ately called THE CRUST OF THE EARTH ; it is the
thickness of the strata that lie nearest the sur-
face of our planet, and that are exposed in deep
chasm-like valleys, or by the labour of man in
his boring and mining operations. These works
scarcely attain a perpendicular depth of more
than two thousand feet (less than JLth of a Ger-
man mile) below the level of the sea ; conse-
quently only ^^^ji^th of the semidiameter of the
earthC*). The crystalline masses which are
ejected by active volcanoes, and which are
mostly of the same nature as the rocky matters
of the surface, come from unknown, certainly
sixty times greater absolute depths than those
which the labours of man have reached. In
situations where seams of coal dip to rise again
at distances determinable by accurate measure-
ments, it is easy to ascertain the depth of the
basin in which the strata lie. In this way we
learn, that in some places (Belgium, for exam-
ple) the coal measures, together with the or-
ganic remains of a former world, which they
contain, frequently lie more than five, or even
six, thousand feet below the present level of
the sea(") : aye, that the mountain limestone
and Devonian basin-shaped bent strata, descend
even to twice that depth. If we now contrast
these subterraneous basins with the mountain
summits which have hitherto been held as the
highest portions of the uplifted crust of the

earth, we obtain a distance of 37,000 feet, it
nearly ^^th of the earth's semidiameter lie-
twixt the point of extreme descent and that of
highest elevation. This, in the perpendicular
dimension and space-filling superposition of
rocky strata, would still be the only theatre of
geognostic investigation, even did the general
surface of the earth reach the height of Dhaw-
alagiri, in the Himalaya chain, or of Sorata, in
Bolivia. All that lies under the sea level deep-
er than the basins referred to above, than the
works of man, than the bottom of the ocean,
attained in various places with the plumb-line
(Sir James Ross sounded with 25,400 feet of
line, without reaching the bottom), is even as
much unknown to us as is the interior of the
other planets belonging to our system. We
also know but the mass of the whole earth and
its mean density, compared with the superior
and to us solely accessible strata. Where all
knowledge of the chemical and mineralogical
natural constitution of the interior of the earth
fails us, we are again thrown upon conjecture,
just as we are with reference to the farthest
bodies that revolve about the sun. We can de-
termine nothing with certainty upon the depth
at which the rocky strata of the crust of the
globe should be regarded as existing in a tena-
cious softened state, or as a molten liquid ;
upon the cavities filled with elastic vapours ;
upon the condition of liquids when they are
heated red-hot under enormous pressures ; or
upon the law of the increment of density from
the surface of the earth down to its centre.

The consideration of the increment of tem-
perature of the interior of our planet with in-
creasing depths, and of the reaction of the in-
terior upon the surface, has led us to the ex-
tensive series of volcanic phenomena. These
manifest themselves as earthquakes, effusions
of gaseous fluids, hot springs, mud-volcanoes,
and lava-streams, from craters ; the influence
of elastic force is also shown in unquestionable
alterations in the level of the general surface.
Extensive levels, variously-partitioned conti-
nents, are upheaved or sunk ; the solid is part-
ed from the fluid ; but the ocean itself, trav-
ersed by hot and cold currents that flow through
it like rivers, congeals at either pole, and sets
into solid rocky masses, here stratified and
immoveable, there broken into moveable packs
and islets. The boundaries of the sea and
land, of the fluid and the solid, are variously
and frequently changed. Plains, too, oscillate
upwards and downwards. After the elevation
of continents, long clefts or chasms took place,
mostly parallel to one another, and then, in all
probability, at similar epochs in time, and
through them, were mountain-chains upheav-
ed : salt pools and great inland seas, which
were long inhabited by the same creatures,
were forcibly separated. The fossil remains
of shells and zoophytes bear witness to their
original connection. And so we come, follow-
ing the relative dependence of phenomena, from
the consideration of the fashioning forces, work-
ing deep in the interior of the earth, to that
which shakes and shatters its upper crust, and
which, through the force of elastic vapours,
flows out as a molten stream of earth (lava)
from open fissures.

The same forces that uplifted the Andes and

FIGURE OF THE EARTH.

Himalaya chains, even to the regions of eter-
nal snow, produced new admixtures and new
textures in the rocky masses, and altered the
strata which had been thrown down at earlier
periods, from waters teeming with life and or-
ganized matters. We recognize here the suc-
cession of formations, separated according to
their age and superposed, in their dependence
upon the alterations in form of the surface,
upon the dynamical relations of the upheaving
forces, upon the chemical actions of outbreak-
ing vapours upon the fissures.

The form and distribution of continents — in
other words, of the dry land— of that portion of
the crust of the earth which is susceptible of
the vigorous evolution of vegetable life, stands
in intimate relationship, and potential recipro-
city of action, with the all-surrounding sea. In
this the organizing force is almost wholly ex-
pended upon the animal world. The liquid el-
ement, again, is invested by the gaseous atmo-
sphere, an aerial ocean, into which the mount-
ain chains and lofty plateaus of the dry land
rise like reefs and shoals, induce a vast variety
of currents and changes of temperature, collect
moisture from the region of the clouds, and by
the running streams that furrow their sides,
spread motion and life over all.

If the Geography of Plants and Animals de-
pends on these intricate contrasts in the distri-
bution of sea and shore, in the formation of the
surface, and the direction of isothermal lines
(or zones of mean annual temperature), so, on
the other hand, are characteristic differences
in the races of men and their relative numeri-
cal distribution over the face of the earth — the
last and noblest object of a physical description
of the globe — influenced not. by these natural
relations alone, but at the same time, and es-
pecially by progress in civilization, in mental
improvement, in political superiority grounded
upon national cultivation. Some races, cling-
ing to the soil, are supplanted and annihilated
by the dangerous vicinity of more politic com-
munities : a faint historical trace is soon all
that remains of them ; other races, in numbers
not the strongest, put forth upon the liquid ele-
ment ; and almost omnipresent by means of
this, have they alone, though late, attained to
a general graphical knowledge of the surface,
of all the seaboards at least, of our planet from
pole to pole.

Here, then, and before I have touched upon
the individual, in our natural picture of the

TELLURIC SPHERE OF PHENOMENA, I haVO ShOWU

in General, how from considerations on the form
of the globe, and on the ceaseless manifesta-
tions of force in its electro-magnetism and sub-
terranean heat, the relations of the earth's sur-
face in horizontal extension and elevation, the
geognostic type of mineral formations, the realm
of the ocean, and of the atmosphere with its
meteorological processes, the geographical dis-
tribution of plants and animals, and, finally, the
physical gradations of the human race, alone,
but in all circumstances susceptible of spiritual
culture, may be comprised in one and the same
contemplative survey. This unity of contem-
plation presupposes an enchainment of phenom-
ena according to their intimate connections.
A mere tabular arrangement of phenomena
Vfi )uld not accomplish the purpose I prescribed

myself; it does not satisfy the want of that

COSMICAL REPRESENTATION which thC aspCCt of

nature by sea and land, the diligent study of
formations and forces, and the lively impression
of a natural whole, which has been made upon
my mind in the course of my travels in various
and dissimilar climates of the globe. Much
that in this essay is so exceedingly defective,
with the accelerated rate at which knowledge
of all the departments of physical science ad-
vances, will probably ere long be corrected and
filled up. It lies, indeed, in the path of devel-
opment which every science pursues, that that
which long stood isolated, becomes connected
by degrees and subjected to higher laws. I but
point out the empirical way, along which I,
and many minded like myself, advance, full of
expectation that "Nature," as Plato tells us
Socrates once desired, " shall have interpreta-
tion according to'reason"('*).

Our account of terrestrial phenomena, in their
principal features, must begin with the form
and relations in space of our planet. And here,
too, it may be said, that not merely does the
mineral constitution, the crystalline, the gran-
ular, the dense masses filled with petrefactions,
but also the geometrical figure of the earth it-
self, bear witness to the mode of its origin ; its
figure is its history. An elliptical spheroid of
rotation indicates a once soft or semi-fluid mass.
To the oldest geognostic incidents, writ down,
and clearly legible to the understanding eye, in
the book of nature, belongs the flattening [of
the poles of the earth], and to adduce another
and nearly related instance, the perpetual di-
rection of the greater axis of the moon's spheroid
towards the earth ; i. e. the accumulation of mat-
ter upon that half of the moon which we see, and
which determines the relation between the peri-
od of rotation and that of revolution. And the
same law extends to the oldest formative epochs
of all the satellites. " The mathematical figure
of the earth is that which it would have were
its surface covered with water in a state of re-
pose ;" to this are referred all geodetic meas-
urements of degrees reduced to the sea-level.
From this mathematical surface of the earth,
the physical one, with all its accidents and in-
equalities of the solid, difFers("). The whole
figure of the earth is determined when the quan-
tity of oblateness and the magnitude of the
equatorial diameter are known. To obtain a
complete picture of the figure, however, it were
necessary to have measurements in two direc-
tions perpendicular to each other.

Eleven pneasurements of degrees, or deter-
minations of the curvature of the earth's sur-
face in different countries, of which nine belong
exclusively to the present century, have given
us accurate information on the dimensions oi
the earth, which Pliny long ago designated as
" a point in the infinity of space*'('«). If these
measurements do not agree in the curvature of
diflferent meridians under the same degrees of
latitude, this very circumstance vouches for
the sufficiency of the instruments and of the
methods employed, for the accuracy of partial
results true to nature. The inference from
the increase of attractive force proceeding from
the equator towards the pole, in reference to
the figure of a planet, depends on the distribu-

59

FIGURE OF THE EARTH.

tion of density in its exterior. If Newton, upon
theoretical grounds, and also excited to the in-
quiry by Cassini's discovery of the flattening
of Jupiter's poles in 1666("), determines the
flattening of the earth as a homogeneous mass
at 2 jTF^h, in his immortal work, the Principia,
actual admeasurements, under the influence of
the new and more perfect analysis, have shown
that the oblateness of the earth's spheroid, the
density of the strata being assumed to go on
increasing towards the centre, amounts to 3^,^th
very nearly.

Three methods have been employed to deter-
mine fundamentally the curvature of the earth's
surface : measurements of degrees, pendulum
experiments, and certain inequalities of the
moon's orbit. Thg first of these methods is an
immediate geometro-astronomical one ; in the
other two, conclusions are drawn from care-
fully observed motions, in regard to the forces
which occasion these motions, and, from these
forces, in regard to their causes, viz. the ob-
lateness of the earth in its polar axis. I have
here, in the general picture of nature, referred
exclusively to the application of these methods,
because their certainty reminds us forcibly of
the intimate concatenation of natural phenom-
ena in their forms and forces, because this ap-
plication has itself become the happy occasion
of improving all our instruments, whether op-
tical or those that are employed in the meas-
urement of space or of time — the very founda-
tion of astronomy and mechanics in reference
to the moon's motions, and the determination
of the resistance which the oscillation of the
pendulum experiences — and because it has even
served to open up peculiar and untrodden paths
to analysis. After the researches on the par-
allax of the fixed stars, which led to the dis-
covery of aberration and nutation, the history
of the sciences presents us with no problem
second in importance to that in which the re-
sult sought is a knowledge of the mean oblate-
ness of the earth, and the certainty that the
figure of our planet is not a regular one. In
none of the long and laborious ways by which
the goal is attained in scientific investigations,
is higher general cultivation, or more perfect
knowledge of mathematical and astronomical
science required than in this. The comparison
of eleven measurements of degrees, among
which three extra European — the old Peruvian
one, and two East-Indian— are included, cal-
culated in conformity with the severe theoret-
ical requirements of Bessel, has given a^^th
as the measure of oblateness of the polar di-
ameter of the earth('"°). From this it appears
that the polar semidiameter is 10,938 toises^
about 2j geographical miles, shorter than the
equatorial semi-diameter of the elliptical sphe-
roid of rotation. The bulging under the equa-
tor, therefore, in consequence of the curvature
of the surface of the spheroid in the direction
of gravity, comes to something more than 4^-
times the height of Mont Blanc, only 2^ times
the probable height of Dhawalagiri, in the Him-
alaya range. The moon's equation, in other
words the perturbation in longitude and lati-
tude of the moon, from the latest researches of
Laplace, give nearly a similar degree of oblate-
ness as the measurement of degrees of the me-

ridian—viz. jh^ih. Experiments with the pen-
dulum indicate a much more considerable
amount of flattening— viz. 2 5^th(^").

Galileo, when a boy, during divine service^
and somewhat inattentive to the matter in
hand, as it would seem, perceived that the
whole height of a roof might be ascertained
from the dissimilar times in which chandeliers,
suspended at different elevations, oscillated j
but he certainly did not imagine that the pendu-
lum would one day be carried from pole to
pole, with a view to determine the figure of the
earth ; or rather to afford evidence of the
length of the seconds-pendulum being affected
by strata of the earth of unequal density. These
local attractions are complex, undoubtedly ; but
over extensive districts of country they show
themselves almost identical in point of amount.
These geognostic relations of an instrument
for the measurement of time; this peculiar
property of the pendulum to act a» a plumb-line,
and give us intelligence of the unseen deep,
even in volcanic islands('**), and on the acclivi-
ties of uplifted continental mountain chains(*"),
to indicate dense masses of basalt and melam-
phyx instead of caverns, combine to render dif-
ficult, despite the wonderful simplicity of the
method, the attainment of any general result
as to the figure of the earth from observations
on the oscillation of the pendulum. Even in
the astronomical part of the measurement of a
degree of latitude, the occurrence of mountain
masses, or of denser strata in the ground, have
a disturbing and prejudicial influence, although
not to the same extent as in pendulum experi-
ments.

As the figure of the earth exerts a powerful
influence on the motion of other planetary bod-
ies, especially on that of her immediate satel-
lite, so, on the other hand, does the very per-
fect knowledge we possess of the motion of
the moon enable us to draw counter-conclu-
sions in regard to the figure of the earth. From
this, as Laplace(^**) has significantly observed,
might an astronomer, " without leaving his ob-
servatory, by a comparison of the lunar theory
with positive observations, determine, not only
the figure and magnitude of the earth, but far-
ther, its distance from the sun and from the
moon ; results which have only been obtained
by long and toilsome journeys undertaken to
the remotest countries of either hemisphere.'^
The oblateness which has been deduced from
the inequalities of the moon has this advantage,
possessed neither by single measuremcBts ol
degrees nor pendulum observations, that it is a
MEAN applicable to the whole planet. Contrast-
ed with the velocity of rotation, it informs us,
moreover, of the increase of density of the
earth's strata from the surface towards the
centre ; an increase which the comparison of
the relation of the axes of Jupiter and Saturn
with their periods of rotation also reveals in
both of these great planets. In this way does
knowledge of mere external configuration fead
to conclusions in regard to the internal consti-
tution of the heavenly bodies.

The northern and southern hemispheres ap-
pear to have nearly like curvatures under equal
parallels of latitude(^°*) ; but pendulum experi-
ments, and measurements of degrees of the
meridian, give such different results in refer-

INTERNAL TEMPERATURE OF THE EARTH.

ftt

ence to particular portions of the surface, that
nothing like a regular figure can be inferred
which would accord with the whole of the re-
sults hitherto obtained in these ways. The
true figure of the' earth stands in the same re-
lation to a regular figure. " as the uneven sur-
face of ruffled stands to the even surface of
unruffled water."

After the earth has been measured, it must
be WEIGHED. Pendulum vibrations and the
plumb-line have alike served to determine the
nean density of the earth — whether the rela-
tive density was investigated by a combina-
lion of astronomical and geodetical operations,
through the deflection of a plumb-line from the
perpendicular in the vicinity of a mountain, or
by contrasting the length of the pendulum beat-
ing seconds on a plain and on the summit of a
neighbouring height, or, finally, by the applica-
tion of the torsion-balance, which may be re-
garded as a delicate horizontally swinging pen-
dulum. Of these three methods(^"), the last
is the safest, inasmuch as it is independent of
the difficult determination of the density of the
minerals composing the spherical segment of a
mountain in the neighbourhood of which the
observations are made. The latest research-
es, which are those of Reich, give 5-44 as the
mean density of the whole earth ; that is to
say, the earth is nearly 5^^ times more dense
than pure water. But as the mineral species
which constitute the dry land have a mean
density of no more than about 2-7, and the dry
land and the ocean together a density of but
1-6, it follows from this assumption how much
the elliptical unequally oblated strata of the in-
terior must increase in density through pres-
sure, or through heterogeneousness of material
towards the centre. And here we see, again,
with what propriety the pendulum, both that
which swings perpendicularly and that which
swings horizontally, has been designated a ge-
ognostical instrument.

But the conclusions to which the use of such
an instrument leads, have induced distinguish-
ed natural philosophers to take entirely oppo-
site views of the constitution of the earth's in-
terior. It has been calculated at what depth
liquid, and even aeriform bodies, would come
to surpass platinum, and even iridium, in den-
sity, through the proper pressure of their own
superimposed strata ; and in order to bring the
oblateness of the earth's spheroid, known with-
in a very small quantity, into harmony with
the assumption of a single and infinitely com-
pressible substance, the acute Leslie has gone
so far as to have described the nucleus of the
earth as a hollow sphere, filled with '* impon-
derable matter of enormous repulsive powers."
These daring and arbitrary conjectures have
given rise to still more fantastical dreams in
non-scientific circles. The hollow sphere has,
by degrees, been peopled with plants and ani-
mals, and furnished, moreover, with a couple
of small subterranean planets — Pluto and Pros-
erpine, which there dispense their gentle light.
An unvarying temperature reigns in this inter-
nal space, and the air, self-luminous by com-
pression, might well make the presence of the
subterraneous planets, Pluto and Proserpine,
unnecessary. Near the north-pole, under the

82d parallel of latitude, where the aurora bo-
realis streams up into the sky, there is an en-
ormous opening, through which it were easy to
descend into the hollow sphere. To such a
subterranean expedition the late Sir Humphry
Davy and I were repeatedly and publicly invi-
ted by Captain Symmes. So strongly is the
morbid disposition of man inclined, unencum-
bered with the contradictory testimony of well-
established facts or generally admitted natural
laws, to fill unseen space with marvellous
forms ! But the celebrated Halley himself, at
the end of the 17th century, had hollowed out
the earth in the course of his magnetical spec-
ulations : a subterraneous freely rotating nu-
cleus, by its varying position, occasions the
diurnal and annual variations of the magnetical
declination ! What was a mere lively fiction
with the clever Holberg, has, in our days, with
tedious solemnity, been attempted to be decked
out in a scientific garb.

The figure of the earth, and the degree of
solidity or density which it possesses, stand in
intimate connection with the forces which an-
imate our globe, in so far, namely, as these
forces are not excited or awakened from with-
out by our planetary position opposite to a self-
luminous central body. The oblateness, a con-
sequence of the operation of the centrifugal
force upon a rotating mass, reveals the pristine
or former state of fluidity of our planet. On
the setting or solidification of this fluid, which
we are accustomed to conjecture as existing in
the shape of a vaporiform matter, originally
heated to a very high temperature, an enormous
amount of latent caloric became free. If the
process of consolidation began in the way
Fourier will have it, by radiation from the sur-
face into celestial space, the parts of the earth
which are situated towards the centre must
still be hot and molten. While, after long ra-
diation of the heat of the central parts towards
the surface, a state of stability in the tempera-
ture of the earth is finally attained, it is at the
same time assumed that, with an increase in
depth, there will also be a regular progressive
increase of temperature. The temperature of
the water which flows from bores of great
depth into the bowels of the earth (Artesian
wells), immediate experiments on the temper-
ature of the rocks in mines, above all, however,
the volcanic activity of the earth, in other words,
the discharge of molten mineral streams through
fissures in the surface, bear testimony in the
most incontestable manner to this increase of
temperature in the upper strata of the earth at
considerable depths. From conclusions which,
it is true, are only founded on analogy, it is
more than probable that the temperature goes
on increasing in a still greater degree towards
the centre.

The conclusions which have been presented
to us by an ingenious, and, for this class of in-
quiries, singularly perfect analytical calculus,
on the motion of heat in homogeneous metallic
spheroids(^"), can only be applied, with many
precautions, to the actual constitution of our
planet, in consequence of our ignorance of the
matter of which the earth is composed, of the
various capacities for heat and powers of con-
duction inherent in the superimposed masses,

54

MEAN TEMPERATURE OF THE EARTH.

and of the chemical transformations which
solid and fluid bodies undergo under enormous
pressures. Most difficult of all, for our powers
of comprehension, is the conception of the
boundary line betwixt the fluid masses of the
interior and the concrete mineral species of the
outer crust of the earth, of the gradual increase
of solidity in the strata, and the state of tena-
cious semi-fluidity of earthy matters, to which
the known laws of hydraulics can only apply
under considerable modifications. The sun and
moon, which keep the ocean in a state of alter-
nate ebb and flow, act in all likelihood even
down to these depths. Beneath a vault of al-
ready consolidated mineral strata, periodical
rises and falls of a molten mass may, indeed,
be readily enough conceived as taking place,
and occasioning inequalities in the pressure ex-
erted against the vault. The amount and the
influence of such oscillations can, however, be
but small ; and if the relative position of the
attracting heavenly bodies must here also pro-
duce spring-tides, it is still certain that the con-
cussions of the earth's surface which take place,
are not to be ascribed to these, but to other
more powerful internal forces. There are
groups of phenomena, the existence of which
it is still useful to adduce in illustration of the
universality of the attractive influences of the
sun and moon upon the external and internal
life of the globe, however little we may feel
ourselves in a condition to determine numeri-
cally their amount.

From experiments on Artesian wells, which
agree pretty closely, the temperature of the
upper crust of the earth appears, on an aver-
age, to increase 1° of the centigrade thermom-
eter for each 92 Paris feet in perpendicular
depth. Did this increase go on in arithmetical
progression, then, as I have already had occa-
sion to observe(^<'8), would a granitic stratum
at the depth of Sy^^ geographical miles (from
four to five times the depth of the highest peak
in the Himalaya range) be in a molten state.

In the body of the earth there are three kinds
of motion of heat to be distinguished : the first
is periodical, and, according to the position of
the sun and the season of the year, alters the
temperature of the earth's strata according as
the heat penetrates from above downwards, or
as it passes in the same way from below up-
wards. The second kind of motion is likewise
an effect of the sun, and is of extraordinary
slowness : part of the heat which has pene-
trated the equatorial regions is propagated
along the interior of the crust of the earth
towards the poles, and there escapes into the
atmosphere and distant space. The third kind
of motion is the slowest of all : it consists in
the secular cooling of the body of the earth, in
the dissipation of the small amount of the prim-
itive heat of the planet which at the present
time is still given off from its surface. This
loss which the central heat suffers was very
considerable at the epochs of the oldest revolu-
tions of the globe ; since the commencement
of the historical period, however, it is scarcely
mensurable by our instruments. The surface
of the earth, from the foregoing view, is inter-
mediate between the red heat of the interior
strata, and the temperature of space, which is
probably below the congealing point of mercury.

The periodical variations of temperature
which the altitude of the sun and the meteoro^
logical processes of the atmosphere occasion,
are propagated in the interior of the earth, but
only to very small depths. This slow conduc-
tion of heat by the ground, however, lessens
the loss of warmth in the winter, and is favour-
able to deeply-rooted trees. Points which lie
at different depths in a vertical line come to
the maximum and minimum of the communi-
cated temperature in very different times. The
more distant they are from the surface, the
smaller are the differences of these extremes.
On the continent of Europe, between the paral-
lels of 48° and 52°, the stratum of invariable
temperature occurs at from 55 to GO feet deep ;
even at half this depth the oscillations of the
thermometer, in consequence of the influence
of the seasons, scarcely amount to half a de-
gree. In tropical climates, on the contrary,
the stratum of invariable temperature is met
with at no more than a foot below the surface ;
and this fact has been used by Boussingault,
in an able manner, as a convenient and, in his
opinion, accurate way of determining the mean
temperature of the air of a place(^°'). This
mean temperature of the air at a determinate
point, or in a group of points of the surface ly-
ing near to one another, is, in a certain meas-
ure, the fundamental element of the climatic
relations, and also of the relations in reference
to civilization of a country ; but the mean tem-
perature of the whole surface is very different
from that of the earth itself The oft-repeated
questions, whether, in the course of centuries,
this has suffered any considerable change?
whether the climate of a country has become
deteriorated 1 whether the winters have not
become milder, and the summers in the same
proportion colder 1 can only be decided by the
thermometer ; and the discovery of this instru-
ment scarcely dates three half-centuries back ;
its rational application no more than about 120
years. The nature and novelty of the means,
therefore, prescribe very narrow bounds to in-
quiries into the temperature of the air. It is
quite otherwise with the solution of the groat
problem of the internal heat of the whole globe.
In the same way as from the unaltered rate of
a pendulum we can conclude on the unchanged
preservation of its temperature, so does the
unaltered velocity of rotation of the earth on
its axis inform us of the degree of stability of
its mean temperature. This perception of the
relations between the length of the day and the
earth's temperature, is one of the most brilliant
applications of a long knowledge of the heaven-
ly motions to the thermal condition of our plan-
et. The velocity of rotation of the earth, to
wit, depends on its volume : precisely as the
axis of rotation of the mass that was cooling
gradually by radiation would become shorter,
so through diminution in temperature must the
velocity of rotation be increased, and the length
of the day be abridged. Now by a comparison
of the secular inequalities of the moon's mo-
tions with the eclipses that have been observed
in the more ancient times, it appears that since
the age of Hipparchus. for full 2000 years there-
fore, the length of the day has not varied by the
one-hundredth part of a second. From this,
again, and, within the utmost limits of the de-

MAGNETISM.

55

CTease(*"), the mean temperature of the body
of the earth is discovered not to have altered,
in the course of 2000 years, by the yiy^th part
of a thermometrical degree.

This invariableness of form farther implies
great invariability in the distribution of density
in the interior of the earth. The translatory
movements effected by the erfiptions of our
present volcanoes, the outbursts of ferruginous
lavas, and the filling up of empty chasms and
hollows vrith dense masses of rock, are there-
fore to be regarded as mere superficial phe-
nomena, as peculiarities of parts of the earth's
crust, which, in point of magnitude, when con-
trasted with the semidiameter of the earth, are
utterly insignificant.

The internal heat of the planet, in its course
and distribution, I have described almost ex-
clusively from the results and beautiful experi-
ments of Fourier. Poisson, however, doubts
the uninterrupted increase of the terrestrial
heat from the surface to the centre. He be-
lieves that all the heat has penetrated from
without inwards, and that the temperature of
the interior of the earth depends on the very
high or very low temperature of the universal
space through which the solar system has mo-
ved. This hypothesis, devised by one of the
most profound mathematicians of the age, has
satisfied himself only ; it has met with little
countenance from other natural philosophers
and geologists.

But whatever be the cause of the internal
temperature of our planet, and of its limited or
unlimited increase in the deeper strata, it still
leads in this Essay to present a general picture
of nature, through the intimate connection of
all the primary phenomena of matter, and
through the common bond which surrounds
the molecular forces, into the obscure domain
of Magnetism. Changes of temperature elicit
magnetical and electrical currents. Terres-
trial magnetism, whose principal character in
the threefold manifestation of its force is an
uninterrupted periodic changeableness, is ascri-
bed either to the unequally heated mass of the
earth itself('"), or to those galvanic currents
which we consider as electricity in motion, as
electricity in a circuit returning into itself("^).
The mysterious march of the magnetic needle
is equally influenced by the course of the sun,
and change of place upon the earth's surface.
The hour of the day can be told between the
tropics by the motion of the needle, as well as
by the oscillations of the mercury in the barom-
eter. It is suddenly, though only passingly,
affected by the remote Aurora, by the glow of
heaven, which emanates in colours at one of
the poles. When the tranquil hourly motion
of the needle is disturbed by a magnetical
storm, the perturbation frequently proclaims
itself over hundreds and thousands of miles, in
the strictest sense of the word simultaneously,
or it is propagated gradually, in brief intervals
of time, in every direction over the surface of
the earthO"). In the first case the simultane-
ousness of the storm might serve, like the
e'dipses of Jupiter's satellites, fire signals, and
well-observed shooting stars, within certain
limits, for the determination of geographical
longit^es. It is seen with amazement, that

the tremblings of two small magnetic needles,
were they suspended deep in subterraneous '

space, measure the distance that intervenes
between them ; that they tell us how far Kasan
lies east from Gottingen, or from* the banks of
the river Seine. There are regions of the earth
where the seaman, enveloped for days in fog,
without sight of the sun or stars, without all
other means of ascertaining the time, can still
accurately determine the hour by the variation
of the dip of the needle, and know whether he
be to the north or south of the port towards
which he would steer his courseC^*).

If the sudden perturbation of the needle in
its hourly course makes known the occurrence
of a magnetic storm, the seat of the perturbing
cause — whether it be to seek in the crust of
the earth itself, or in the upper regions of the
air — remains, to our extreme regret, as yet un-
determined. If we regard the earth as an ac-
tual magnet, then are we compelled, according
to the decision of the deep-thinking founder of
a general theory of terrestrial magnetism,
Frederick Gauss, to admit that every eighth of
a cubic metre, or y^ths of a cubic foot of the
earth, possesses, on an average, at least as
much magnetism as a one-pound magnetic
bar("*). If iron and nickel, and probably co-
balt also — not chrome, as was long sup-
posed("*), be the only substances which be-
come permanently magnetic, and retain polar-
ity by a certain coercive force, the phenomena
of Arago's rotative magnetism, and Faraday's
induced currents, assure us, on, the other hand,
that probably all terrestrial substances may
passingly comport themselves magnetically.
From the experiments of the first of the great
natural philosophers just mentioned, water,
ice(^*^), glass, and charcoal, affect the oscilla-
tions of the needle precisely as quicksilver does
in the rotatory experiments. Almost all sub-
stances show themselves in a certain degree
magnetic when they are conductors ; that is to
say, wiien they are traversed by a current of
electricity.

How ancient the knowledge of the attractive
power of natural magnetic iron appears to have
been among the western nations (and this his-
torically well-authenticated fact is remarkable
enough), the knowledge of the polarity or di-
rective force of the magnetic needle, and its
connection with terrestrial magpetism, was,
nevertheless, confined to the extreme east of
Asia, to the Chinese. A thousand years and
more before the commencement of our era, in
the dark epoch of Codru and the return of the
Heraclidae to the Peloponnesus, the Chinese
had already magnetic cars, upon which the
moveable arm of a human figure pointed inva-
riably to the south, as a means of finding the
way through the boundless grassy plains of
Tartary ; in the third century, indeed, of the
Christian era, at least seven hundred years,
therefore, before the introduction of the ship's
compass upon European seas, Chinese crafl
were sailing the Indian ocean under the gui-
dance of MAGNETIC SOUTHERN INDICATI0N("').

I have shown in another work("'), what ad-
vantages this method of determining topograph-
ical position, this early knowledge and applica-
tion of the magnetic needle, wholly unknown
in the west, gave the Chinese geographers over

56

MAGNETISM.

those of Ancient Greece and Rome, to whom,
for example, the true course of the Apennines
and Pyrenees was never known.

The magnetic force of our planet reveals it-
self on its surface in three classes of phenom-
ena, one of which shows the variable intensity
of the force, the two others indicate the varia-
ble direction in the inclination or dip, and in the
horizontal departure, or declination, from the ter-
restrial meridian of the place, the aggregate out-
ward effect of which may be graphically exhibit-
ed by means of three systems of lines, one isody-
namical, another isoclinial, a third isogonial ;
or lines of equal force, of equal dip, and of
equal variation. The distance and relative po-
sition of these ever-moved, oscillatingly-pro-
gressive curves, do not always remain the
same. The total variation or declination of
the magnetic needle has not, however, chan-
ged appreciably, or at all in certain parts of
the earthc^'"), in the Western Antilles and in
Spitzbergen, for example, in the course of a
whole century. Even so, the isogonial curves,
when, in the course of their secular movement,
they have passed from the surface of the sea
to a continent or island of considerable magni-
tude, are seen to linger long upon it, and then
they curve off again in their farther progress.

These gradual transformations which accom-
pany the translation, and in the course of time
extend the empire of the Eastern and Western
variations so unequally, render it difficult, in
the graphic representations that belong to dif-
ferent centuries, to discover the transitions and
analogies of the forms. Every branch of a
curve has its own history ; but this history,
among the Western nations, nowhere mounts
higher than to.the remarkable epoch, the 13th of
September, 1493, when the rediscoverer of the
New World recognized a line of no variation,
three degrees west from the meridian of Flores,
one of the Azores('''^). The whole of Europe,
a small portion of Russia alone excepted, has,
at the present time, western variation ; whilst,
at the end of the 17th century, first in London
(1657), and then in Paris (1669), with a differ-
ence of twelve years, consequently, despite the
short distance between them, the needle point-
ed directly to the north pole. In East Russia,
to the east of the mouth of the Wolga, of Sar-
atow, Nijni-Novogorod and Archangel, the
Eastern variation presses in upon us from
Asia. Two excellent observers, Hansteen and
Ad. Erman, have given us intelligence of the
remarkable double curvature of the variation-
lines in the wide-spread realms of Northern
Asia ; convex towards the pole betwixt Ob-
dorsk and Obi and Turuchansk, concave be-
twixt lake Baikal and the bay of Ochotsk. In
this last part of the earth, in the north-east of
Asia, betwixt the Werchojansk mountains,
Jakutsk and Northern Corea, the isogonial lines
form a remarkable system enclosed within it-
self. This ovoidal formation("') is more reg-
ularly repeated, and on a larger scale, in the
South Sea, nearly in the meridian of Pitcairn
island and the Marquesas group, betwixt the
parallels of 20° N. and 45° S. latitude. One
might feel disposed to regard so singular a
configuration of self-included, almost concen-
tric lines of variation, as the effect of a pecu-
liar local constitution of the body of the earth ;

but should these apparently isolated systems
move on in the course of centuries, then, as
in all grand natural forces, must some more
general cause of the phenomenon be presumed.

The hourly changes in the variation, depend-
ent on the true time, and apparently determin-
ed by the sun so long as it is above the horizon
of a place, decrease in their angular amount
with the magnetic latitude. Near the Equator,
in Rawak Island, for example, they are scarce-
ly more than from 3 to 4 minutes, whilst in the
middle of Europe they amount to from 13 to 14
minutes. Now, as the north end of the needle,
in the whole of the northern hemisphere, trav-
els, on an average, between half-past 8 a.m. and
half-past 1 P.M. from east to west; and in the
southern hemisphere the same north end trav-
erses from west to east during the same period
of time, it has been recently, and with reason,
remarked("'), that there must be a region of
the earth situated, probably, between the ter
restrial and the magnetic equator, in which no
horary changes of the variation will be observ-
ed. But this fourth curve, that of no-move-
ment, or rather of no change in horary varia
tion, has not yet been discovered.

As the points of the earth's surface where
the horizontal force disappears, are called mag
netic poles, and a greater degree of importance
has been attached to these points than belonga
to them of right(^'^*), in the same way is that
curve called the magnetic equator upon which
the dip of the needle is nothing. The positioD
of this line, and its secular variations of form,
have been made objects of particular investiga
tion in recent times. From the admirable work
of Duperrey(^*^), who, between the years 1822
and 1825, crossed the magnetic equator six
times, it appears that the two points in which
the line of no dip cuts the terrestrial equator,
and so passes from one hemisphere into anoth-
er, are so unequally divided, that, in the year
1825, the node by the island of St. Thomas, on
the west coast of Africa, lay in a direct line
188^° from the node in the South Sea by the
little Gilbert's Island (nearly in the meridian
of the Viti group), in the Southern Pacific. In
the beginning of the present century, at an el-
evation of 11,200 feet above the level of the
sea, in 70° V S. lat. and 48° 40' W. long., I
was enabled astronomically to determine the
point at which the Andes betwixt Quito and
Lima, in the interior of the New Continent,
are crossed by the magnetic equator. From
this point, proceeding westward, it lingers in
the southern hemisphere, through almost the
whole of the South Sea, slowly approaching the
terrestrial equator. It first crosses over into
the northern hemisphere shortly before it reach-
es the Indian Archipelago ; it then just touch-
es the south point of Asia, and enters the Afri-
can continent westward from Socotora, close
to the straits of Babelmandel, where it is at its
greatest elongation from the terrestrial equa-
tor. Traversing the unknown regions of cen-
tral Africa in a south-western direction, the
magnetic equator returns, in the gulph of
Guinea, into the southern tropic, and in its
course across the Atlantic separates so far
from the terrestrial equator, that it meets the
coast of Brazil at Os Ilheos, to the north of
Porto Seguro, in 15° S. latitude. Fron^ence

MAGNETISM.

67

to the lofty plains of the Cordilleras, betwixt
the silver mines of Micuipampa and the old
seat of the Incas, Caxamarca, where I had an
opportunity of observing th(? inclination, it trav-
erses the whole of South America, which, in
these southern latitudes, like the interior of
Africa, remains a magnetic terra incognita up
to the present time.

Late observations collected by Colonel Sa-
bine(^2*), inform us that the node of the Island
of St. Thomas has travelled four degrees, from
east to west, between 1825 and 1837. It would
be of the highest importance to know whether
the opposite node of Gilbert's Island, in the
South Pacific, had not travelled as far west-
ward, towards the meridian of the Carolinas.
The general survey now given must suffice to
connect the different systems of not perfectly
parallel isoclinal lines with the great phenome-
non of equilibrium which manifests itself in the
magnetic equator. It is no small advantage
for the establishment of the laws of terrestrial
magnetism, that the magnetic equator, whose
fluctuating alterations of form, and whose nodal
motion in the midst of the various magnetic lat-
itudes, exert an influence("') upon the dip of
the needle in the remotest countries of the
world, is, with the exception of one-fifth, whol-
ly oceanic ; it is therefore, through the remark-
able relations betwixt the sea and the land, by
so much the more accessible, as we are now
in possession of a means of determining both
variation and dip, with great accuracy, on ship-
board, whilst the vessel is holding her course.

We have now portrayed the distribution of
magnetism upon the surface of our planet, ac-
cording to the two forms of variation and dip.
The third form, that of intensity of the force,
still remains, and this is graphically expressed
by isodynamic curves (lines of equal intensity).
The investigation and measurement of this
force, in its terrestrial relations, by the oscilla-
tions of a vertical or horizontal needle, have
only excited general and lively interest since
the beginning of the nineteenth century. The
measurement of the horizontal force has been
made capable of a degree of accuracy, particu-
larly by the application of delicate optical and
chronometrical instruments, which far exceeds
that of all the other magnetical determinations.
If, with reference to the immediate application
to navigation and steering, the isogonal lines
be the more important, the isodynamic, espe-
cially those that indicate the horizontal force,
present themselves, according to the most re-
cent views, as those which promise the richest
harvest for the theory of terrestrial juagnet-
ism(i28). One of the earliest facts discovered
by observation, was this : that the intensity of
the sum of the force increases from the equa-
tor towards the pole(i*9).

For a knowledge of the measure of this in-
crease, and the establishment of all numerical
relations of the law of intensity, embracing the
whole earth, we are especially indebted to the
ceaseless activity of Colonel Sabine, who, ever
since the year 1819, after he had made obser-
vations on the same needle oscillating at the
American north pole, in Greenland, in Spitz-
bergen, on the coast of Guinea, and in the Bra-
zils, has been incessantly engaged m collecting
and alranging whatever may serve to illustrate

the direction of the isodynamic lines. I have
myself given the first plan of an isodynamical
system, divided into zones, for a small part of
South America. These isodynamic lines are
not parallel to the lines of equal dip ; the in-
tensity of the force is not, as was at first be-
lieved, weakest at the magnetic equator ; it is
not once equal at any part of the same. If
Erman's observations in the southern portion
of the Atlantic, where a zone of declining in-
tensity runs from Angola, over the island of
St. Helena, to the coast of Brazil (0706), be
compared with the very latest observations of
that distinguished navigator Sir James Clark
Ross, it is found that the force upon the surface
of our planet increases nearly in the ratio of one
to three towards the magnetic south pole, and
where Victoria Land stretches away from Cape
Crozier towards Mount Erebus, that volcano
which rises from everlasting ice to the height
of 11,600 feet above the level of the sea('3'>). If
the intensity in the vicinity of the magnetic
south pole be expressed by 2052 ( — the inten-
sity which I found on the magnetic equator in
North Peru is still assumed as unity, or 1 000),
Sabine found it, in Melville Island, 24° 27' N.
lat., near the magnetic north pole, only 1-624 ;
whilst, in the United States, near New- York —
nearly under the same parallel of latitude as
Naples, consequently — it was 1 -803.

Through the brilliant discoveries of Oersted,
Arago, and Faraday, the electrical charge of
the atmosphere has been brought to approxi-
mate more closely to the magnetical charge of
the earth. If Oersted found that electricity in-
duced magnetism in the vicinity of the body
which was conducting it, so, on the other hand,
it was shown in Faraday's experiments that
free magnetism gave rise to electricity. Mag-
netism is one of the numerous forms in which
electricity manifests itself The ancient sus-
picion of the identity of electrical and magnet-
ical attraction has been demonstrated in the
present age. " If electrum" (amber), says
Pliny (^^^), in the sense of the Ionic natural
philosophy of Thales, " becomes inspired by
friction and warmth, it attracts bark and dried
leaves, exactly like the magnetic iron stone."
The same words occur in the literature of a
people inhabiting the easternmost parts of Asia,
in the discourse, laudatory of the magnet, of
the Chinese natural philosopher, Kuopho(^32)
It was not without surprise that I myself ob-
served, among the children at play on the woody
banks of the Orinoco, the offspring of native
tribes in the lowest grade of civilization, that
the excitement of electricity by friction was
known. The boys rubbed the dry, flat, and
shining seeds of a creeping leguminous plant
(probably a negretia), until they attracted fibres
of cotton wool and chips of the bamboo. 1 his
amusement of these coppery children is calcu-
lated to leave a deep and solemn impression be-
hind it. What a chasm lies between the elec-
trical play of these savages, and the discovery
of the lightnmg conductor, of the chemically
decompounding pile, of the light-evolving mag-
netical apparatus ! In such gulphs, millenni-
ums in the history of the intellectual progress
of mankind lie buried !

The ceaseless change, the fluctuating move-
ments which are observed in all magnetical

NORTHERN LIGHTS.

phenomena — those of the dip, variation, and in-
tensity, according to the hour of the day and
even of the night, according to the season and
the lapse of whole years, permit us to suspect
the existence of very dissimilar partial sys-
tems of electrical currents in the crust of the
earth. Are these currents, as in Seebeck's ex-
periments, thermo-magnetical, and immediate-
ly excited by unequal distribution of heat 1 Or
shall we not rather regard them as induced by
the position of the sun, and through the influ-
ence of his heat 1(^2') Has the rotation of our
planet and the accident of the diflTerent veloci-
ties impressed upon the several zones, accord-
ing to their distance from the equator, any in-
fluence upon the distribution of magnetism ■!
Shall the seat of the currents, in other words,
of the electricity in motion, be sought for in
the atmosphere, in the interplanetary spaces,
or in the polarity of the sun and moon 1 Gali-
leo, in his celebrated Dialogo, is disposed to
ascribe the parallel direction of the earth's axis
to a magnetic point of attraction in space.

When the interior of the earth is regarded
as molten and subjected to an enormous pres-
sure, as raised to a degree of temperature such
as we have no means of estimating, then must
the idea of a magnetical nucleus of the earth
be abandoned. All magnetism is certainly lost
at a white heat("*) ; it is still manifested when
iron is raised to a dull red ; and however dif-
ferent the modifications undergone by the mole-
cular condition, and the coercive force of mat-
ter dependent on it, may be in experiments,
there still remains a considerable thickness of
the crust of the earth which might be assumed
as the seat of magnetic currents. In what re-
gards the old explanation of the horary varia-
tions of the deflection, by the progressive heat-
ing of the earth in the apparent course of the
sun from east to west, it must be owned that
we are here limited to the very outermost sur-
face ; inasmuch as the thermometers now sunk
in the ground in so many places, and so care-
fully observed, show us how slowly the sun's
heat penetrates even to the moderate depth of
a few feet. And then the thermal state of the
surface of the ocean, covering two-thirds of
the globe, is little favourable to such an expla-
nation, when the question is one of immediate
mean influence, not of induction from the ae-
rial and vaporous covering of our planet.

To all questions as to the ultimate physical
cause of phenomena so complicated, there is
no satisfactory answer to be given in the pres-
ent state of our knowledge. It is only in ref-
erence to the three-fold manifestations of the
earth-force, to that which meets us as mensu-
rable relations of Space and of Time, as the
Normal or conformable to laws in the Variable,
that brilliant advances have lately been made,
through the determination of numerical mean
values. Since the year 1828, from Toronto, in
Upper Canada, to the Cape of Good Hope and
Van Dieman's Land, from Paris to Pekin, the
earth has been covered with magnetical observ-
atories(^"), in which uninterrupted and simul-
taneous observations are made of every reg-
ular and irregular excitement of the earth-force.
A decrease of the magnetic intensity amount-
ing to the y^^^^th part is measured ; at cer-
tain epochs, observations are noted every 2i

minutes through an entire period of 24 hours.
An illustrious English astronomer and natural
philosopher(*3') has calculated that the mass of
observations accumulated in the course of three
years, which remain for discussion, amounts to
1,958,000 ! Never has there been so grand, so
delightful an eflTort made to get at the root of
the Quantitative in the laws of a natural phe-
nomenon. We may therefore be permitted to
entertain a well-grounded hope, that these
laws, compared with those which prevail in
the atmosphere, and still more distant spaces,
will gradually bring us nearer and nearer to the
Genetical in magnetic phenomena. Until now
we can only boast that a greater number of
ways which might possibly lead to information
have been opened up. In the physical doctrine
of terrestrial magnetism, which must not be
confounded with the purely mathematical one,
as in the doctrine of the meteorological pro-
cesses of the atmosphere, some completely
satisfy themselves by conveniently denying as
realities all the phenomena which cannot be
explained in conformity with their views.

Terrestrial magnetism, the electro-dynamic
forces which have been calculated by the able
Ampere(^^^), stands at the same time in inti-
mate relationship with the Earth- or North-
ern-Lights [Aurora borealis], as with the in-
ternal and external temperature of our globe,
whose magnetic poles must be regarded as poles
of cold("8). If Haliey('3'), some 128 years ago,
gave it out as a mere bold conjecture that the
northern light was a magnetic phenomenon,
Faraday's brilliant discovery of the evolution of
light through magnetic power has raised that
conjecture to the rank of an empirical certainty.
There are heralds or harbingers of the northern
lights. In the course of the day on which the
lights are to appear, irregular horary movements
of the magnetic needle usually indicate an in-
terruption of equilibrium in the distribution of
the terrestrial magnetism. When this disturb-
ance has attained a great intensity, the equilib-
rium of the distribution is restored by a dis-
charge, accompanied with an evolution of light.
" The northern light itself is not, therefore, to
be regarded as an external cause of the disturb-
ance, but rather as a terrestrial activity raised
to the pitch of a luminous phenomenon, one of
the sides of which is the light, the other the
oscillations of the needle"(**<'). The splendid
phenomenon of coloured northern lights is the
act of discharge, the conclusion of a magnetic
storm ; in the same way as, in the electrical
storm, an evolution of light — lightning — indi-
cates the restoration of the disturbed equilib-
rium in the distribution of electricity. The
electrical storm is usually limited to a small
space, beyond which the state of the electricity
remains unchanged. The magnetic storm, on
the contrary, reveals its influence on the march
of the needle over large portions of continents,
as Arago first observed, and far from the place
where the development of light is visible. It is
not improbable that, as in the case of heavily
charged and threatening clouds, and of frequent
transitions of the atmospheric electricity into
opposite states, it does not always come to dis-
charges by lightning, so also may magnetic
storms produce great disturbances in th^orary

NORTHERN LIGHTS.

motions of the needle over extensive circles,
without there being any necessity for explo-
sions, for luminous effusions from the pole to
the equator, or from one pole to another, in or-
der to restore the equiUbrium.

He who w^ould have all the particulars of the
phenomenon embraced in one picture, should
have the origin and course of a complete ap-
pearance of the northern lights set before him.
Deep on the horizon, nearly m the situation
where it is intersected by the magnetic merid-
ian, the heaven, up to this moment clear,
grows black. There is a kind of hazy bank or
screen produced, which rises gradually, and at-
tains to an altitude of from 8 to 10 degrees.
The colour of the dusky segment passes over
into brown or violet. Stars are visible in it,
but they are seen as in a portion of the sky ob-
scured with dense smoke. A broad bright
luminous arc or seam, first white, then yellow,
bounds the dusky segment ; but as the brilliant
bow arises later than the snjoky-grey segment,
it is impossible, according to Argelander('"), to
ascribe the latter to the effect of mere contrast
with the bright luminous border. The highest
point of the luminous arc, when it has been
carefully measured("*), has usually been found
to be not exactly in the magnetic meridian, but
to vary between 5 and 18 degrees from it, to-
wards the side on which the magnetic declina-
tion of the place of observation lies. In high
northern latitudes, very near the north pole, the
smoky-looking spherical segment appears less
dark ; sometimes it is even entirely absent. In
the situation, too, where the horizontal force is
least, the middle of the luminous arc is seen to
depart farthest from the magnetic meridian.

The luminous bow, in constant motion, flick-
ering and changing its form incessantly, some-
times remains visible for hours before anything
like rays and pencils of rays shoot from it, and
rise to the zenith. The more intense the dis-
charges of the northern lights, the more vividly
do the colours play from violet and bluish-white,
through every shade and gradation, to green
and purplish-red. In our ordinary electricity
produced by friction, in the same way, the spark
first becomes coloured when the tension is high,
and the explosion is violent. The magnetic
fiery columns shoot up at one time singly from
the luminous arch, even mingled with black
rays, like thick smoke ; at another, many col-
umns arise simultaneously from several and op-
posite points of the horizon, and unite in a
flickering sea of flame, to the splendour of which
no description can do justice, and whose lumi-
nous waves assume another and a different
shape at every instant. The intensity of the
northern light is at times so great, that Lowe-
norn perceived its oscillations, in bright sun-
shine, on the 29th of January, 1786. The mo-
tion increases the brilliancy of the phenomenon.
Around the point of the vault of heaven which
corresponds with the direction of the dipping
needle, the rays at length collect together, and
form the corona or crown of the northern lights.
This surrounds the summit, as it were, of a
vast canopy, the dome of heaven, with the mild
radiance of its streaming but not flickering rays.
It is only in rare instances that the phenomenon
proceeds the length of forming the corona com-
pletely. With its appearance, however, the

whole is at an end. The rays now become
rarer, shorter, less intensely coloured. The
crown and the luminous arches break up. By
and by nothing but broad, motionless, and al-
most ashy-grey, pale gleaming fleecy masses,
appear irregularly dispersed over the whole
vault of heaven ; these vanish, in their turn,
and before the last trace of the murky fuligin-
ous segment, which still shows itself deeply on
the horizon, has disappeared. Of the whole
briUiant spectacle, nothing at length remains
but a white delicate cloud, feathered at the
edges, or broken up, as a cirro-cumulus, into
small rounded masses or heaps, at equal dis-
tances.

This connection of the polar light with the
most delicate cirrus-clouds, deserves to be par-
ticularly mentioned ; inasmuch as it shows us
the electro-magnetic evolution of light as part
of a meteorological process The terrestrial
magnetism here manifests itself in its effects
upon the atmosphere, in a condensation of the
watery vapour which it holds dissolved. The
observations, made in Iceland by Thienemann,
who regards the cirro-cumulus, or divided fleecy
cloud, as the substrate of the northern lights,
have been confirmed in later times by Franklin
and Richardson, near the North American mag
netic pole, and by Admiral Wrangel, on the Si-
berian coasts of the icy sea. All observed
'* that the northern lights sent forth the most
brilliant fays when masses of cirro-stratus
floated in the upper regions of the atmosphere ;
and when these were so thin, that their pres-
ence was only known by the formation of a
halo about the moon." These light clouds oc-
casionally arranged themselves, by day, in the
same manner as the rays of the Aurora, and
had the same effect as these in disturbing the
magnetic needle. After a grand nocturnal dis-
play of the northern lights, the same streaks of
clouds that had been luminous over night, were
discovered in the morning arranged in the same
manner^"). The apparently converging polar
zones of clouds (streaks of clouds, in the direc-
tion of the magnetic meridian), which constant-
ly attracted my attention in the course of my
travels on the lofty platforms of Mexico, as well
as in Northern Asia, belong apparently to the
same group of diurnal phenomenaC^**).

Southern hghts have been frequently seen in
England by that able and diligent observer, Dal-
ton ; northern lights in the southern hemisphere,
as low as 45° of latitude (Jan. 14, 1831). In
instances that are not very rare, the magnetic
equilibrium is disturbed at both poles simultane-
ously. I have distinctly stated that northern
polar lights are seen within the tropics, even as
far south as Mexico and Peru. It is necessary
to distinguish, however, between the sphere of
a simultaneous apparition of the phenomenon,
and the zone of the earth in which the phe-
nomenon is displayed almost every night of the
year. As each observer sees his own rainbow,
so also, doubtless, does he see his own polar
light. A great portion of the earth engenders
the radiating Light-phenomenon at the same
time. Many nights can be mentioned in which
it was observed simultaneously in England, in
Pennsylvania, in Rome, and in Pekin. When
it is maintained that the northern lights decline
with the decrease of latitude, this must be un-

NORTHERN LIGHTS.

derstood as referring to magnetic latitude, meas-
ured from the magnetic pole. In Iceland, Green-
land, and Newfoundland, on the banks of the
Slave lake, and at Fort Enterprise (in North
Canada), the Aurora is lighted up, at certain
seasons, almost every night, and with its shift-
ing, shivering rays, performs its ** merry dance"
through the sky, as the natives of the Shetland
Islands term it('**). Whilst in Italy the north-
ern light is a great rarity, it is seen with ex-
treme frequency in the latitude of Philadelphia
(39° 57' N. L.), in consequence of the southern
position of the American magnetic pole. But in
the districts of the new continent, and also of
the shores of Siberia, which are remarkable for
the frequency of the phenomenon, there occur
what may be called especial regions of the
northern lights — longitudinal zones in which
they are peculiarly splendid(^".) Local influ-
ences are, consequently, not to be overlooked.
Wrangel observed their brilliancy decline as he
left the shores of the icy sea, about Nijne-Ko-
lymsk, behind him. The experience of the
Northern Polar Expedition seems to indicate
that the evolution of light is not greater in the
immediate vicinity of the magnetic pole than it
is at some distance from this spot.

What we know of the altitude of the northern
light is based on measurements, which, by reason
of the incessant oscillations of the luminous
rays, and the consequent uncertainty of the
parallactic angle, cannot be greatly depended on.
The conclusions come to (not to speak of older
estimates) vary between several miles and three
or four thousand feet("^). It is not improbable
that the northern light is at very different dis-
tances at different times. The latest observers
are disposed to connect the phenomenon, not
with the outer limits of the atmosphere, but
with the region of the clouds itself; they even
believe that the northern streamers may be
moved by winds and currents of air, if the
luminous phenomenon, by which alone the ex-
istence of electro-magnetic emanations becomes
obvious to us, be actually connected with mate-
rial collections of vesicular vapour, or, to speak
more correctly, penetrates these collections,
darting over from one vesicle to another. Cap-
tain Franklin saw a streaming Aurora on Bear
lake, which he believed illuminated the under
side of the stratum of cloud ; whilst Kendal,
who had the watch through the whole of the
night, and never lost the heavens for a minute
from his sight, at the distance of but 4^ geo-
graphical miles, observed no luminous phe-
nomenon whatsoever. The statement, repeat-
ed several times of late, to the effect that
streamers of the northern light have been ob-
served close to the ground, and between the
observer and a neighbouring height, is one of
those points, which, like lightning and the fall
of fire-balls, is exposed to the manifold dangers
of optical deception.

Whether or not the magnetic storm, of which
we have just quoted a remarkable example
of local circumscription within very narrow
bounds, have the noise, besides the light, in
common with the electrical storm, is now ren-
dered extremely doubtful, since the testimony
of the Greenland sledgers, and the Siberian
fox-hunters, is no longer taken unconditionally.
The northern lights have become more silent

since they have been examined more carefully
with the eye and the ear. Parry, Franklin and
Richardson, near the north pole ; Thienemann,
in Iceland ; Gieseke, in Greenland ; Lottin and
Bravais, at the North Cape ; Wrangel and An-
jou, on the shores of the icy sea, have, alto-
gether, looked at thousands of northern lights,
yet never heard any noises. If this negative
testimony be not admitted against two positive
witnesses, Hearne, at the mouth of the Copper-
mine river, and Henderson, in Iceland, it must
still be remembered that Hood heard the same
noises — as of musket balls shaken rapidly to-
gether, and slight cracklings, during the occur-
rence of the northern lights, indeed, but also
on the following day, when there was no Au-
rora in the heavens ; and then it must not be
forgotten, that Wrangel and Gieseke were firm-
ly convinced that the noises heard were owing
to contractions of the ice and crust of snow,
in consequence of a sudden cooling of the air.
The belief in a crapkling noise did not take its
origin among the people, but with learned trav-
ellers, and in this way : the flashing of elec-
tricity in attenuated atmospheres having been
known from an early period, the northern light
was forthwith declared to be an effect of at-
mospheric electricity, and then the noises were
heard that ought to have been heard. Recent
experiments with the most delicate electrome-
ters, however, contrary to all expectation, have
hitherto given merely negative results ; the
state of the aerial electricity has not been found
altered during the prevalence of the most brill-
iant Auroras.

All the three manifestations of force of the
terrestrial magnetism — Declination, Inclina-
tion, and Intensity, on the contrary, are affect-
ed at once by the northern lights. In one and
the same night, and from hour to hour, the Au-
rora affects the same end of the needle differ-
ently, now attracting it, now repelling it. The
assertion that the facts collected by Parry at
Melville Island, near the magnetic pole, lead to
the conclusion that the northern lights do not
disturb the needle, but rather have a " calming
effect" upon it, is completely contradicted by a
more careful perusal of Parry's own journa](^*^),
by the beautiful observations of Richardson,
Hood, and Franklin in North Canada, and more
lately still, by Bravais and Lotten in Lapland.
The process in the northern lights is, as we
have above observed, the act of restoration of
an equilibrium disturbed. The effect upon the
needle varies according to the measure of force
in the explosion. It was only unobservable at
the nocturnal winter station at Bosekop,* when
the luminous phenomenon showed itself very
feebly and deep on the horizon. The upshoot-
ing radiate cyhnders of the northern light have
been aptly compared to the flame which, in the
closed circuit of the Voltaic pile, arises be-
tween two charcoal points at a distance from
one another, or, according to Fizeau, between
a silver and a charcoal point, and to that which
is drawn or thrown off from the magnet. This
analogy at all events renders superfluous the
assumption of those metallic vapours in the
atmosphere which some natural philosophers

* [Vide Kaemtz's Complete Course of Meteorolog^y, by
C. V. Walker, (Plates, 8vo. Lond. 1845), for a full accouut
of the Aurora.— Tb.]

EARTHQUAKES.

01

have imagined as the substrate of the northern
lights.

If the luminous phenomenon which we as-
cribe to a galvanic current, t. e, a motion of
electricity in a circuit returning into itself, be
designated by the indefinite name of the North-
ern light, or the Polar light, nothing more is
thereby implied than the local direction in
which the beginning of a certain luminous phe-
nomenon is most generally, but by no means
invariably, seen. What gives this phenomenon
its greatest importance is the fact which it re-
veals, viz. that the Earth is luminous ; that
our planet, beside the light which it receives
from the central body, the sun, shows itself
capable of a proper luminous act or process.
The intensity of the Earth-light, or rather the
degree of luminosity which it diffuses, exceeds
by a little, in the case of the brightest coloured
rays that shoot up to the zenith, the light of
the moon in her first quarter. Occasionally, as
on the 7th of January, 1831, a printed page can
he read without straining the sight. This light-
process of the earth, which the Polar regions
exhibit almost incessantly, leads us by analogy
to the remarkable phenomenon which the planet
Venus presents. The portion of this planet
which is not illuminated by the sun, glows oc-
casionally with a proper phosphorescent gleam.
It is not improbable that the Moon, Jupiter, and
Comets, besides the reflected sun-light recog-
nizable by the polariscope, also emit light pro-
duced by themselves. Without insisting on the
problematical but very common phenomenon
of sheet-lightning, in which the whole of a deep
massy cloud is flickeringly illuminatecf for sev-
eral minutes at a time, we find other examples
of terrestrial evolutions of light. To this head
belong the celebrated dry-fogs of 1783 and 1831,
which were luminous by night ; the steady lu-
minottsness of large clouds, perfectly free from
all flickering, observed by Rosier and Beccaria ;
and even the pale, diffused light, as Arago has
well observed^'**), which serves to guide us in
the open air, in thickly clouded autumn and
wintry nights, when there is neither moon
nor star in the firmament, nor snow upon the
ground. As in the phenomenon of the Polar
lights occurring in high northern latitudes, in
other words, in electro^magnetic storms, floods
of flickering and often parti-coloured light
stream through the air, so, in the hotter zones
of the earth, between the tropics, are there
many thousand square miles of ocean which
are similarly light-engendering. Here, how-
ever, the magic of the light belongs to the or-
ganic forces of nature. Light-foaming flashes
the bursting wave, the wide level glows with
lustrous sparks, and every spark is the vital
motion of an invisible animal world. So mani-
fold is the source of terrestrial light. And shall
we conceive it latent, not yet set free in va-
pours, as a means of explaining Moser's pic-
tures— a discovery in which reality still pre-
sents itself to us as a vision shrouded in mys-
tery?

As the internal heat of our planet is connect-
ed on one hand with the excitement of electro-
magnetic currents and the light-producing pro-
cess of the earth (a consequence of the burst-
ing of a magnetic storm), so on the other hand

does it also manifest itself as a principal source
of geognostic phenomena. These we shall con-
sider in their connection, and in their transition
from a merely dynamic concussion, and from
the upheaving of continents and mountain mass-
es, to the production and effusion of gases and
liquids, of boiling mud, and of red hot and molt-
en earths, which harden into crystalline rocks.
It is no trifling advance in the newer geognosy
(the mineralogical portion of the physics of the
globe), that it has firmly founded the concate-
nation of phenomena here indicated. The
views of modern geognosy lead off from mere
hypothesis, which trifles or plays with its sub-
ject, and seeks to explain, severally and apart,
every manifestation of force of the old globe ;
they shew the connection of the various matters
ejected with what appertains only to change in
reference to space — concussion, elevation, de-
pression ; they arrange side by side groups of
phenomena which at first sight present them-
selves as extremely heterogeneous — thermal
springs, effusions of carbonic acid gas, escapes
of sulphureous vapours, harmless eruptions of
mud, and the awful devastations of burning
mountains. In a grand picture of nature all
this becomes fused in the single conception of
the reaction of the interior of a planet upon its
crust and surface. So do we recognize in the
depths of the earth, in its temperature increas-
ing with the distance from the surface, at once
the germs of concussive movements, of the
gradual elevation of entire continents, or of
mountain chains through lengthened chasms,
of volcanic eruptions, and of the varied produc
tion of mineral species and rocky masses. Buf
it is not inorganic nature alone that has felt the
force of this reaction of the interior upon the
exterior. It is extremely probable that in tht-
primitive world immense discharges of carbonic
acid gas mingled with the atmosphere, excited
the faculty possessed by vegetables of separa
ting carbon from the air, and that thus, in rev
olutions which destroyed extensive forests, in
exhaustible supplies of combustible matter —
lignites and coals of different kinds — have been
buried beneath the upper strata of the earth.
The destiny of man we even recognize as m
part dependent on the fashion of the outer crust
of the globe, on the partitioning of continents,
on the direction of their mountain chains anc'
high lands. To the inquiring spirit is it givet
to mount from link to link in the chain of phe-
nomena, till the point is gained at which in thr»
incipient consolidation of our planet, in the firs*-
transition of the conglobated matter from tb»
vaporous form, the internal heat of the earth,
that heat which does not belong to the actioi
of the sun, was developed.

In our survey of the causal connection ot
geognostical phenomena, we shall begin witit
those which, in their principal features, are dy-
namical, which consist in motion and a changt
in space. Earthquakes of every kind and de*
gree are distinguished by a series of perpendic
ular, or horizontal, or rotatory vibrations fo*
lowing each other in rapid succession. In thr
course of the considerable number of earth
quakes which I have felt in both hemisphere*
of the globe, on shore and at sea, the two firs<
kinds of motion have appeared to me very fre-
quently to take place together. The explosive

63

EARTHQUAKES.

movement such as is produced by the firing of
a mine — the perpendicular action, from below
upwards — was displayed most conspicuously on
the occasion when the town of Riobamba was
destroyed (1797), when the bodies of many of
the inhabitants were thrown upon the hill of
La Culla, which is several hundred feet high,
and rises on the other side of the Lican rivulet.
Tlie propagation of the motion generally takes
place in a linear direction, in waves, and with
a velocity of from five to seven G. geographical
miles in a minute. Sometimes it is in circles,
or in great ellipses, from the centre of which
the vibrations are propagated with decreasing
force towards the circumference. There are
districts which belong to or fall within two mu-
' tually intersecting circles of concussion. In
North Asia, which the father of history(i*°),
and, after him, Simocatta(^*') characterize as
" the Scythian territories free from earth-
quakes," I found the southern part of the Altai
Mountains, so rich in mineral treasures, sub-
ject to the influence of the concussive foci both
of Lake Baikal and the volcanoes of Thian-
Schan, or the Celestial Mountain^"). When
the circles of concussion intersect each other —
when, for instance, a lofty plain lies between
two simultaneously active volcanoes — then
may several systems of waves exist at once,
and not interfere with each other, just as in the
case of fluids. Interference, however, can be
conceived here, as in mutually intersecting
waves of sound. The magnitude of the trans-
mitted wave of succussion is increased at the
surface, in conformity with the general laws of
mechanics, according to which, when motion
is communicated in elastic bodies, the outer-
most free-lying stratum tends to detach itself
from the others.

The waves of succussion can be pretty accu-
rately measured in their direction and total
strength, by the pendulum and the sismomcter
bowl, but in no way investigated in the intimate
nature of their alternations and periodical intu-
mescences. In the city of Quito, which stands
at the foot of an active volcanic mountain — the
Rucu-Pichincha, 8,950 feet above the level of
the sea, and boasts of beautiful cupolas, lofty
fanes, and massive houses several stories high,
I have frequently been surprised at the violence
of the earthquakes by night, which neverthe-
less very rarely occasion rents in the walls ;
whilst in the plains of Peru, apparently much
weaker oscillations injure lowly houses built of
cane. Natives who have stood the shocks of
many hundred earthquakes, believe that the
difference of effect is less connected with the
length or shortness of the waves, with the
slowness or rapidity of the horizontal oscilla-
tion("^), than with the equality of the motion
in opposite directions. Circular or rotatory
concussions are the rarest, but they are the
most dangerous of all. Twistings round of
walls without throwing them down ; planta-
tions of trees, which had previously stood in
parallel rows, deflected ; the direction of the
ridges of fields covered with various kinds of
grain altered, were observed on occasion of the
great earthquake of Riobamba, in the province
of Quito (February 4th, 1797), as well as of those
of Calabria (February 5th and March 28th, 1783).
With the latter phenomenon of rotation, or the

transposition of fields and cultivated plots of
ground, of which one has occasionally taken
the place of another, there is connected a trans-
latory motion, or mutual penetration of several
strata. When taking the plan of the ruined
city of Riobamba, I was shown a place where
the whole of the furniture of one dwelling-house
had been found under the ruins of another. The
loose earth of the surface had run in streams
like a fluid, of which it must be conceived that
it was first directed downwards, then horizon-
tally, and finally upwards. Disputes about the
property, in those instances where things were
carried many hundred toises from their original
stances, were adjusted by the Audiencia, or
Court of Justice.

In countries where earthquakes are compar-
atively much rarer, in the south of Europe for
example, a very general belief, grounded upon
an imperfect induction, prevails(^**) ; viz. that
calms, oppressive heats, and a misty state of
the horizon, are always preludes to an earth-
quake. The erroneousness of this popular be-
lief is not, however, shown by my own experi-
ence only ; it is farther gainsaid by the obser-
vations of all who have lived long in countries
where earthquakes are frequent and violent, as
in Cumana, Quito, Peru, and Chili. I have ex-
perienced earthquakes when the air was clear
and a fresh east wind was blowing, as well as
during rain and thunder storms. Even the
regularity in the horary variations in the decli-
nation of the magnetic needle, and in the press-
ure of the air(*"), remained unaffected within
the tropics on the day of the earthquakes. The
observarions which Adolphus Erman made in
the temperate zone on the occasion of an earth-
quake at Irkutsk, near lake Baikal, on the 18th
of March, 1829, agree perfectly with my expe-
rience. During the violent earthquake of Cu-
mana which happened on the 4th of November,
1799, I found the declination of the needle and
the magnetic intensity unaflfected ; but to my
astonishment the dip was diminished by 48'('**).
I had no suspicion of any error ; yet in all the
other earthquakes which I have experienced in
the high lands of Quito and in Lima, the dip of
the needle remained equally unafTected with
the other elements of the terrestrial magnet-
ism. If in a general way the acts that proceed
deep in the interior of the earth are annoimced
beforehand by no special meteorological phe-
nomenon, by no peculiar aspect of the heavens,
it is on the contrary not improbable, as we shall
see immediately, that in certain very violent
earthquakes the atmosphere has sympathized
or partaken in some measure, and that these,
therefore, do not always act in a purely dy-
namical manner. During the prolonged trem-
blings of the ground in the Piedemontese val-
leys of Pelis and Clusson, extreme changes in
the electrical tension of the atmosphere were
observed, whilst the heavens were free from
storm.

The strength of the dull noise which gener-
ally accompanies an earthquake does not by
any means increase in the same measure as the
strength of the vibrations. I have satisfactorily
made out that the grand concussion in the
earthquake of Riobamba (Feb. 4th, 1797), one
of the most awful catastrophes in the physical
history of our earth, was accompanied by no

EARTHQUAKES.

noise whatever. The great noise (cl gran ruido)
which was heard under the cities of Quito and
Ibarra, but not nearer the centre of the motion
in Tucunga and Hambato, occurred from eigh-
teen to twenty minutes after the proper catas-
trophe. In the celebrated earthquake of Lima
and Callao (28th Oct. 1746), the sound was first
heard Wke a subterraneous peal of tliunder.in
Truxillo a quarter of an hour later, and with-
out any trembling of the ground. In like man-
ner, long after the earthquake of New Granada
(Nov. 16th, 1827), which has been described by
Boussingault, subterraneous detonations were
heard in the whole of the valley of Cauca, with
great regularity at intervals of thirty seconds.
The nature of the noises heard on such occa-
sions is very various : rolling, rattling, clank-
ing like chains, occasionally in the town of
Quito like thunder close at hand ; or it is clear
and ringing, as if masses of obsidian or other
vitrified matters were struck in caverns under-
ground.-. As solid bodies are excellent conduc-
tors of sound, as sound, for example, is trans-
mitted with ten or twelve times the velocity in
burnt clay that it is in air, the subterraneous
noise, it may be easily imagined, will be apt to
be heard at great distances from the place
where it is occasioned. In Caraccas, in the
grassy plains of Calabozo, and on the banks of
the Rio Apure, which falls into the Orinoco, in
the whole of a region of 2300 square miles in
superficial extent, there was heard an extraor-
dinary thundering noise, without any shock of
an earthquake, on the 30th of April, 1812, at the
very time that the volcano of the Island of St.
Vincent, lying 158 geographical miles off, was
pouring an immense stream of lava from its
crater. This, in respect of distance, was as if
an eruption of Vesuvius were to be heard in the
north of France. In 1744, on the occasion of
the great eruption of Cotopaxi, subterraneous
cannonadings were heard at Honda on the Rio
Magdalena. The crater of Cotopaxi, however,
is not only 17,000 feet above the level of Hon-
da, but the two points are separated by the co-
lossal mountain masses of Quito, Pasto, and
Popayan, as well as by valleys and precipices
innumerable, besides lying 109 geographical
miles apart. The sound was certainly trans-
mitted not through the air, but through the
earth from a great depth. In the violent earth-
quake of New Granada (February, 1835), sub-
terraneous thunder was heard at the same time
in Popayan, Bogota, Santa Martha, and Carac-
cas (in the latter for a period of seven hours
without any shock), in Haiti, Jamaica, and round
the lake of Nicaragua in Mexico.

These sonorous phenomena, when they are
accompanied by no perceptible shocks, leave a
remarkably deep impression even v/ith those
who have long dwelt in districts subject to re-
peated earthquakes. All seem to expect with
alarm what is to follow the subterraneous rum-
bling. The most remarkable example of unin-
terrupted subterraneous noises, without any
trace of earthquake, and comparable with no-
thing else, was presented by the phenomenon
which was known in the high lands of Mexico
under the name of the subterraneous beliowings
and thunderings {bramidos y truenos subtcrraneos)
of Guanaxuato("^). This celebrated and flour-
ishing mining town lies far remote from any

active volcano. The noise continued from mid-
night of the 9th of January, 1784, for more than
a month. I have been able to give a particular
account of it from the report of many witnesses,
and from the documents of the municipality
which I was permitted to use. It was (January
13 — 16th) ae if heavy thunder-clouds lay under
the feet of the inhabitants, in which slowly roll-
ing thunder alternated with sharper claps. The
sound drew off as it had come on with decreas-
ing loudness. It was confined to a limited
space ; at the distance of a few miles off, in a
district abounding in basalt, it was not heard
at all. Almost all the inhabitants fled the town
in alarm, although great piles of silver bars
were contained in it ; the more courageous be-
coming accustomed to the subterraneous noise,
by and by returned and disputed possession
with the bands of robbers who had seized on
the treasure. Neither on the surface of the
ground, nor in the workings at the distance of
1500 feet below it, was there the slightest
movement of the earth perceived. Over the
whole of the Mexican highlands no noise of the
same kind had ever been heard before, neither
has the alarming incident recurred. Thus do
chasms in the interior of the earth open and
close ; and the sonorous waves either reach us
or are interrupted in their progress.

The influence of a volcanic mountain in ac-
tion, however terrific or picturesquely grand as
an object of sense, is still always limited to a
very narrow space. It is very different with
the shocks of earthquakes, which are scarcely
appreciable to the eye, but their undulations oc-
casionally extend simultaneously to the dis-
tance of thousands of miles. The great earth-
quake which desolated Lisbon on the 1st of
November, 1755, and whose influences have
been so admirably investigated by the great
philosopher Emanuel Kant, was felt among the
Alps, on the coast of Sweden, in the West In-
dian islands, Antigua, Barbadoes, and Martin-
ique, and on the great Canadian lakes, as well
as in the small inland lakes of the basaltic plains
of Thuringia and the northern flats of Germany.
Distant springs were interrupted in their course,
an incident in earthquakes to which Demetrius
the Galatian directed attention in ancient times.
The hot springs at Tepliz ran dry, and then re-
turned deeply tinged with a ferruginous ochre,
flooding every thing. At Cadiz the sea rose
sixty feet high ; in the lesser Antilles it became
of an inky black colour, and the tide, which
generally rises but about twenty-six or twenty-
eight inches, mounted twenty feet above its
usual level. It has been calculated that a ter-
ritory more than four times the superficial ex-
tent of Europe was shaken by the earthquake
of November 1st, 1755. There is, therefore,
no other outward manifestation offeree known
— the murderous inventions of our race inclu-
ded—through which, in the brief period of a
few seconds or minutes, a larger number of
human beings have been destroyed : in 1793,
sixty thousand perished in Sicily ; from thirty
to forty thousand fell victims in the catastrophe
of Riobamba of 1797, and perhaps five times as
many in Lesser Asia and Syria under Tiberius
and Justin the Elder, about the years 19 and
526 of the Christian era.

There are instances among the Andes of

M

EARTHQUAKES.

South America of the earth having quaked in-
cessantly for several days together ; but I only
know of shocks that were felt almost every
hour for several months, having occurred far
from any volcano^ on the eastern slopes of the
Alps of Mont-Genis, about Fenestrella and Pig-
nerolo, from April, 1808 ; in the United States
of America, betwixt New Madrid and Little
Prairie(^"), to the north of Cin9innati, after
December, 1811 ; in the Paschalic of Aleppo,
in the months of August and September, 1822.
As the vulgar mind can never rise to general
views, and therefore always ascribes great phe-
nomena to local processes of the earth or of
the air, wherever succussions continue for any
length of time, fears for the appearance of new
volcanoes take their rise. In single,* rare in-
stances, this fear has indeed shown itself well-
founded, as in the ease of the sudden rise of
volcanic islands, and in the production of the
volcano of Jorullo, a new mountain, rising 1580
feet above the old neighbouring level, on the
29th of September, 1759, after ninety days of
earthquakes and subterraneous Ihunderings.

Could we have daily news of the state of the
whole of the earth's surface, we should, in all
probability, become convinced that some point
or another of this surface is ceaselessly sha-
ken ; that there is uninterrupted reaction of the
interior upon the exterior going on. This con-
stancy and general diffufiion of a phenomenon,
which is probably connected with the high tem-
perature of the deepest strata of the earth, ex-
plains its independence of the nature of the
rocky masses among which it is manifested.
Shocks of an earthquake have been experien-
ced even in the loosest alluvial deposits of Hol-
land, around Middleburg and Flushing. Gran-
ite and mica slate are shaken in the same way
as mountain limestone and sandstone, as tra-
chytic and amygdaloidal formations. It is not
the chemical nature of the constituents, but the
mechanical structure of the mineral species,
that modifies the propagation of the motion (the
wave of succussion). Where the wave pro-
ceeds regularly along a coast, or by th? foot,
and in the direction of a mountain-chain, it is
occasionally observed that there is an interrup-
tion suffered at certain points. This has been
noticed for centuries. The undulation advan-
ces along the depths, but at the points in ques-
tion it is never felt at the surface. The Peru-
vians say of these unshaken superior strata,
that " they form a bridge"(^*'). As mountain-
chains appear upheaved through fissures, the
walls of these cavities may very well favour or
influence the course of the undulations that run
parallel with the chain ; occasionally, however,
the waves of succussion cut across several
chains, almost at right angles. We thus see
them break through the littoral chains of Vene-
zuela and the Sierra Parirae in South America.
In Asia, the earthquakes of Lahore and the foot
of the Himalayas (Jan. 22d, 1832) were prop-
agated transversely through the chain of Hin-
doo-Cusch to Badakhchan, to the Upper Oxus,
and even to Bokhara(^*°). Unfortunately, too,
the circles of concussion enlarge, in conse-
quence of a single extremefy Violent shock. It
is only since the destruction of Cumana (14th
Dec. 1797) that every shock of the southern
coast is felt in the mica-slate strata of the pen-

insula of Maniguarez, which lies opposite the
limestone or chalk-hills of the fortress. In the
almost incessant undulations of the ground of
the valleys of the Mississippi, Arkansas, and
Ohio, which occurred from 1811 to 1813, the
progress of the motion from south to north
was very striking. It was as if subterranean
impediments had been gradually overcome, and
the wave of commotion then advanced upon
each occasion along the way which had been
opened up.

If an earthquake appear, at first sight, to be
a phenomenon of motion wholly dynamical,
having reference to space only, it is still recog-
nized, on the grounds of the most careful ex-
perience, that it is not only competent to raise
whole districts above their old level (Ulla-Bund,
eastward from the delta of the Indus, for ex-
ample, after the earthquake of Cutch, in June,
1809, and the coast of Chili, in November,
1822), but farther, that during the shock, hot
water (Catania, 1818), hot steam (valley of the
Mississippi, near New Madrid, 1812), mephitic
or irrespirable gases, which are injurious to the
pasturing herds and flocks of the Andes, mud,
black smoke, and even flames (Messina, 1782,
Cumana, 14th Nov. 1797), have been dischar-
ged. During the great earthquake of Lisbon,
Nov. 1, 1755, flames and a column of smoke
were seen to rise from a newly- formed fissure
in the rock of Alvidras, near the city. The
smoke became on each occasion where it ap-
peared, by so much the more dense as the sub-
terraneous noise increased in loudness(^®').
When the town of Riobamba was destroyed in
1797, the earthquake was not accompanied by
any eruption of the volcano which is so close
at hand ; but Moya, a singular mass, compound-
ed of carbon, crystals of augite, and the silice-
ous coats of infusory animalcules, was pushed
out of the ground in numerous small and pro-
gressive cones. The escape of carbonic acid
gas during the earthquake of New Granada
(16th Nov. 1827), from fissures in the Magda-
lena valley, caused the suffocation of many
snakes, rats,' and other creatures that live in
holes. Sudden changes in the weather, too,
the setting in of the rainy season at unusual
periods in the tropics, have occasionally fol-
lowed great earthquakes in Quito and Peru.
Do gaseous fluids, escaping from the interior
of the earth, then become mingled with the at-
mosphere 1 or, are these meteorological pro-
cesses the effect of a disturbance of the atmo-
spherical electricity by the earthquake'? In
the countries of tropical America, where some-
times not a drop of rain falls for ten months,
the inhabitants look upon repeated shocks of
earthquakes, which cause no danger to their
low cane huts, as a happy indication of plenty
of rain, and consequently of fertility.

The intimate connection of all the phenom-
ena now described is still buried in obscurity.
Elastic fluids are undoubtedly the cause, as
well of the slight and uninjurious tremblings of
the earth, which continue for many days (as in
1816 at Scaccia, in Sicily, previous to the ele-
vation of the new island called Julia), as of the
frightful explosions which are announced by
noises. The focus of the mischief, the seat of
the moving power, lies deep beneath the crust
of the earth ; how deep, we know even as little

¥

wsm

INTERESTING WORKS

JUST PTTBLISHBD.BT

HARPER & BROTHERS, NEW-YORK.

THE NEW REFORMATION.

MOW SEi.D7, WITH O0RIOUS ILLUSTRATIVE PLATE, PRICE 25 CENTS, OR MUSLIN, 37^ (»lfT8.

JOHN RONGE,

THE HOLY COAT OF TREVES,

AND THE NEW GERMAN CATHOLIC CHURCH.

Including authentic details of the events connected with the recent exhibition of the pretended " Coat of our Lwd" in
the Cathedral of Treves, during the months of August and September, 1844 : comprising the letters and protestatidM of
the author against the imposition and superstitions of the Roman Catholic priests, &c.

This publication is exceedingly opportune : it will be pensed with deep interest by the Prgtestant eonuntmitj at
large. — Commercial Advertiser.

The noble protest of Ronge has been circulated in Germany, not by thousands, but by millions of copies ; and it has b«Mi
hailed with loud applause by all classes, because it expresses a public sentiment, and finds a response in all hearts.—
New- York Observer.

PILGRIMAGE TO TREVES.

nr OKE VOLUME ItHO, BBAirTIFtrf.LT PKIKTEB, PRICE 75 «EIfT8.

\ PILGRIMAGE TO TREVES,

THKOrQH THE TAIllT BP THE MEUSB, AND THE FOREST OF ABDENNES.

BY CHARLES EDWARD ANTHON, ESQ.

This is th« production of a young American who had the rare fortune to be present at the most marvellous oecBrrence
of the 19th century— the exhibition o( the Holy Robe. In addition to a very graphic description of this extraordinary
event, which, from the excitement it has created, seems destined ts be an era in the Christian Church, this unpretend-
ing volume is replete with antiquarian lore, relating to the city of Charlemagne, from which the " Pilgrimage" commen-
ees — the intermediate historic and poetic ground ; and of the once renowned city of Treves, with which i»^ closes. It is ths
work of a scholar, and cannot fail to enlist a profound inteTeet.— Oswego Advertiser.

EUGENE SUE'S GREAT WORK.

HARPER & BROTHERS

HAVE JUST PUBLISHED, NEATLY PRINTED, IN PAPER COVER, NEW AND CHEAP

EDITION ®r VOLUME I., COMPRISING THE FIRST EIGHT NUMBERS, BEINS

ABOUT HALF THE ENTIRE WORK OP

THE WANDERING JEW.

B Y E U G E N E S U E.

FRICE ONX.7 TWENT7-FIV& CZZNTS.

In order to render this chefd^asuvre of modern French fiction, which is now
rapidly approaching its completion, universally accessible, Harper & Broth-
ers have determined on- issuing a new edition, reduced in price to the lowest
possible advance over the actual cost of its publication. No work of modem
times has attracted such a prodigious amount of readers in all parts of the
civilized world as this extraordinary production, which is redolent with scenes
of the most intense and thrilling interest, incomparably -more vivid, artistic, and
dramatic than may be found in most works of its class.

PREPARING FOR EARLY PUBLICATION.

TO BE ISSUED IN NUMBERS, ELEGANTLY PRINTED ON THE FINEST PAPER,

AN ILLUSTRATED EDITION

or

THE WANDERING JEW.

Embellished by numerous beautifully-executed engravings on wo«d, after
the splendid ©riginals by the firs* artists of Paris.

HARPER & BROTHERS, PUBLISHERS, NEW- YORK.

Price One Shilling.

€ 0 S II 0 S:

A SURVEY

OF THE

GENERAL PHYSICAL HISTORY

THE UNIVERSE.

BY

ALEXANDER VON HUMBOLDT.

NEW-YORK:

HARPER & BROTHERS, PUBLISHERS,

82 CLIFF STREET.
184 5.

MORSE'S NEW PICTORIAL GEOGRAPHY.

PRICE FIFTY CENTS.

BMBELIISIEB BY NEARLY ONE HUNDRED AND FIFTY ENfiRAVINeS AND ABOUT FIFTY KAPS,
EXECUTED m THE NEW GEROGRAPHIC PROCESS.

No equivecal evidence of the great merits of this popular New School Geography' is afl!brd«
©d by the faet that nearly one hundred thousand copies have been already disposed of within
the brief interval of its publication. It will be found one of the most beautiful in its pictorial
embellishments, lucid and simple in its adaptation to the purposes of instruction, as well as
one of the cheapest ef all works of the kind ever produced. The maps are both novel and
attractive, being over fifty in number, printed in colours by the new cerographic process.

TESTIMONIALS FROM THE PHILADELPHIA PUBLIC SCHOOLS.

Tlie best work on Geography in the United States or
6reat Britain: it should find its way into the CoKimon
Schools and all seminaries of learning in the TJ. States.
Its admirable arrangement and portability render it an ei-
eellent work of reference ; no person should be without it.

Amssbw Gbozibb, Principal of Reed St. Gram. School.

Ayalnable acquisition to all engaged either in imparting,
or receiving instruction. Its conciseness and mmplicity of
arrangement, and its numerous and beautiful embellish*
ments, Muinot fail to render it deservedly popular.

"W. H. Pile, Principal qf N. E. Gram. School.

I kave examined with some care the " Geography^* by
Morse, and can say that I am particularly pleased with it.
I think it clear and concise in its views, and that the maps
and letter-press being in juxtaposition, is a recommendation
not likely ta be passed by in silence. This arrangement is
calculated tc facilitate the progress of the learner, inasmuch
as he has net to look tc a separate book for his map : thus
time is gained, and more ground gone over in the same pe-
ned. I would therefore skeerfully recommend it to all who
ftre in want of such a work.

W. a. S. AoNBw, Prineipal of Zone St. Pub. tthoel.

We CMtanr in the opinion with Mr. Agnew.

James Rhoass, Principal of N. W. Gram. School.
A. T. W. Wbioht, Principal cf Model School.

I decidedly appreve of it ; the facility afforded the pupil
(a referring to the maps, the correctness of the political di-
visions, and of the population of towns ; the eoneiseness of
style and deecripticn, and the cheapness, as well as the
neatness and beauty of the typographical eieeutjon of the
work are, in my opinion, strong recommendations to the
public W. W. Woo», Principed if S. W. Gram. Soh.

It 1b the best work on the subject with which I am ao-
qvainted. It has several advantages over ether works cf

the kind ; one is, that the map, questions on the map, and
description of each country, are on the same page.
S. F. Watson, Principal of Catherine St. Gram. SchtoL

I cheerfully ecncur in the above recommendation.
B. E. CHAMBKRLiif , Prtn. of ButioHttood St. Gram. Seh^

Novelty does not necessarily imply improvement, but in
this instance we have an improvement by which the efforts
of the young pupil will be very much assisted in the acqui
sition of geographical knowledge.

M. S. Cleavbnoer, ) Principals ef Locust St.

E. H. Cox, J Gram. School.

I have examined the work, and think it well adapted to
the use of schools. Apart from the consideration that it«
descriptions are written in a concise, yet perspicuous stylo,
the convenient general arrangement of the work and its na<
merons illustratiens render it superior to any system of Ge-
ography now in use.
L. 0. Smith, Prin. of T. Ladies Gram. School, Zone St.

It afibrds me pleasure to recommend it to teachers and
the public in general. The arrangement is well planned*
and affords many facilities to the study of geography that
were much desired. The maps are certainly much supericr
to any thing of the kind that has yet appeared.

L. Hopper, Principal <f Third St. School.

I have no hesitation in assigning to it the first rank amen^
similar books now in use ; its excellent maps, and beautiful
pietorial illustrations, are calculated to arrest the attention
of the pupil, and impress instruction indelibly en his mem-
ory. Wm. Robbbts, Prtn. of Moyamtnsing Gram. Seh,

Having examined " Morsels School Geography,''^ we thfak

it admirably calculated to carry out the views of its author

P. A. Cresor, Principal of S. S. Gram. School

S. D. JOHNSTOIT.

L. N. BoswBLI.

HARPER & BROTHERS, PUBLISHERS, NEW-YORK.

AKB MAT BS OBTAINED OF THB BOOKSELLERS THROUOHOVT THS VNITCD STAISaw

EARTHQUAKES.

65

as we do what the chemical nature of the va-
pour of such high tension may be. Encamped
on the edge of two craters, on Vesuvius, and
on the castellated rock which overlooks the
vast gorge of Pichincha, near Quito, I expe-
rienced periodical and very regular shocks,
and, each time, from 20 to 30 seconds before
red-hot ashes or vapours were ejected. The
shocks were by so much the stronger as the
explosions were later of occurring, and the va-
pour consequently had been longer accumula-
ting. In this simple fact, confirmed by the ex-
perience of so many travellers, lies the general
solution of the phenomenon. Active volcanoes
are to be regarded as safety-valves for sur-
rounding districts. The danger of the earth-
quake increases when the opening of the vol-
cano is stopped up, and there is no longer a
free communication with the atmosphere ; but
the destruction of Lisbon, of Caraccas, Lima,
Cashmir (1554)^", and of so many towns of
Calabria, Syria, and Asia Minor, teaches us,
that on the whole the force of earthquakes is
by no means greatest in the vicinity of still ac-
tive volcanoes.

As the pent-up force of a volcano acts in
shaking the ground, so does the concussion re-
act, in its turn, upon the volcanic phenomenon.
The occurrence of fissures favours the rise of
the cones through which eruptions take place,
and the processes which go on within these
cones in free contact with the atmosphere. A
column of smoke, which had been seen for
months rising from the volcano of Pasto, in
South America, disappeared suddenly on the
occurrence of the great earthquake of Riobam-
ba, in the province of Quito, art the distance of
48 geographical miles to the south (Feb. 4,
1797). After the earth had long continued to
tremble in the whole of Syria, in the Cyclades,
and in Cuhcea, the convulsions ceased suddenly
upon the eruption of a stream.of" red-hot mud"
(lava from a crack) in the Lelantine plain, near
Chalcis("3). The admirable geographer of
Amasia, who has preserved the record of this
fact, adds : " Since the mouths of Etna have
been opened, through which the fire belches
forth, and since, in this way, heated masses
and water can be ejected, the lands by the sea-
shore are no longer so frequently shaken as
they were in times before the separation of
Sicily from Lower Italy, when there was no
communication with the surface."

In earthquakes, therefore, we have evidence
of a volcano-producing force ; but such a force,
as universally diffused as the internal heat of
the globe, and proclaiming itself everywhere,
rarely gets the length of actual eruptive phe-
nomena ; and when it does so, it is only in
isolated and particular places. The formation
of extensive veins or dykes, in other words, the
filling up of fissures with crystalline matter
ejected from the interior, such as basalt, mela-
phyre, and greenstone, interferes by degrees
with the free escape of vapours ; which, con-
fined, become operative, through their tension,
in three ways : concussively ; explosively, or sud-
denly up and down ; and, as first observed in a
large portion of Sweden, liftingly or continu-
ously, and only in long periods of time per-
ceptibly altering the relative level of the sea
and land.
I

Before we quit this great phenomenon, which
has been here considered not so much in its in-
dividual as in its general physical and geognos-
tical relations, we must advert to the cause of
the indescribable, deep, and quite peculiar im-
pression which the first earthquake we experi-
ence makes upon us, even when it is accom-
panied by no subterranean noises. The impres-
sion here is not, I believe, the consequence of
any recollection of destructive catastrophes
presented to our imagination by narratives of
historical events : what seizes upon us so won-
derfully is the disabuse of that innate faith in
the fixity of the solid and sure-set foundations
of the earth. From early childhood we are
habituated to the contrast between the mobile
element, water, and the immobility of the soil
on which we stand. All the evidences of our
senses have confirmed this belief But when
suddenly the ground begins to rock beneath us,
the feeling of an unknown mysterious power in
nature coming into action, and shaking the solid
globe, arises in the mind. The illusion of the
whole of our earlier life is annihilated in an in-
stant. We are undeceived as to the repose of
nature, we feel ourselves transported to the
realm, and made subject to the empire, of de-
structive unknown powers. Every sound — the
slightest rustle in the air — sets attention on the
stretch. We no longer trust the earth upon
which we stand. The unusual in the phenom-
enon throws the same anxious unrest and
alarm over the lower animals. Swine and dogs
are particularly affected by it ; and the very
crocodiles of the Orinoco, otherwise as dumb
as our little lizards, leave the shaken bed of the
stream and run bellowing into the woods.

To man the earthquake presents itself as an
all-pervading unlimited something. We can re-
move from an active crater ; from the stream
of lava that is pouring down upon our dwelling
we can escape ; with the earthquake we feel
that whithersoever we fly we are still over the
hearth of destruction. Such a mental condition,
though evoked in our very innermost nature, is
not, however, of long duration. When a series
of slighter shocks occur in a district one after
another, every trace of alarm soon vanishes
among the inhabitants. On the rainless coasts
of Peru nothing is known of hail, nor of explo-
sions of lightning and rolling thunder in the
bosom of the atmosphere. The subterraneous
noise that accompanies the earthquake there
comes in lieu of the thunder of the clouds. Use
and wont for a series of years, and the very
prevalent opinion that dangerous earthquakes
are only to be apprehended two or three times
in the course of a century, lead the inhabitants
of Lima scarcely to think more of a slight shock
of an earthquake than is thought of a hail-storm
in the temperate zone.

Having now taken a general survey of the
activity, and likewise of the internal life of the
globe : in its contained heat, in its electro-mag-
netic tension, in its luminous emanations at the
poles, in its irregularly-recurring phenomenon
of motion, we come to elementary material
PRODUCTION, to chemical changes in the crust
of the earth, and in the composition of the at-
mosphere, which are in like manner the conse-
quence of planetary vital activity. From the

66

HOT SPRINGS.

ground we see effusions : of watery vapour and
of gaseous carbonic acid, mostly free from all
admixture of azote("*) ; of carburetted hydro-
gen gas (in the Chinese province of Sse-Tschu-
an("*) for thousands of years, and in the State
of New York, where, in the village of Fredonia,
it has lately been employed for economical pur-
poses in heating and lighting ; of sulphuretted
hydrogen gas ; of sulphur fumes, and more
rarely of sulphurous and hydrochloric acid va-
pours(^"). Such emanations from fissures in
the ground do not only indicate the dominion
of volcanoes long extinct or still burning ; they
are farther observed exceptionally in districts
in which neither trachyte nor any other volcanic
rock meets the eye exposed upon the surface.
In the Andes of Quindiu I have seen sulphur
precipitated from hot sulphureous vapours issu-
ing out of mica slate, at a height of 6410 feet
above the level of the sea('^^) ; whilst the same,
and, as it used to be regarded, primitive rock,
in the Cerra Cuelo, near Ticsan, south of Quito,
exhibits an enormous bed of sulphur in pure
quartz.

Of all the air-springs which the earth pours
forth, those of carbonic acid gas are still at the
present time the most important both in num-
ber and extent. Germany, in her deeply-cut
valleys of the Eifel, in the neighbourhood of
Lake Lach, in the Kesselthal of Wehr, and in
Western Bohemia, as also in the burning hearths
of the primeval world, or their vicinity, shews
us these effusions of carbonic acid as a kind
of last effort of volcanic activity. In former
epochs, where, with a higher temperature of
the earth, and the frequency of fissures yet un-
filled, the processes which we are here descri-
bing proceeded more actively, where carbonic
acid gas and watery vapours were mingled with
the atmosphere in larger quantities than at
present, the youthful vegetable world, as Adolph
Brongniart("8) has acutely observed, must have
attained almost everywhere, and independently
of geographical position, to the most rank lux-
uriance and evolution of its organs. In the
ever hot, ever moist atmosphere, surcharged
with carbonic acid, vegetables must have found
such vital excitement, such superfluity of nour-
ishment, as enabled them to supply the material
of those beds of coal and lignite, the exhaustion
of which it is difficult to conceive, and which
now serve as foundations for the physical
strength and the welfare of nations. Such beds
are principally contained in basins, and are pe-
culiar to certain parts of Europe. They are
abundant in the British Isles, in Belgium, in
France, on the Nether Rhine, and in Upper
Silesia. In the same primeval times of all-
pervading volcanic action, too, must those enor-
mous quantities of carbonaceous matter have
issued from the bowels of the earth which all
the limestone rocks contain, and which, separ-
ated from oxygen, and represented in the solid
form, composes about an eighth part of the ab-
solute bulk of these great mountain masses
("^). The carbonic acid which the atmosphere
still contained, and which was not absorbed by
the alkaline earths, was gradually consumed
by the vegetation of the primeval world, so that
the atmosphere, purified by the processes of
vegetable life, by and by contained no more of
the gas than was uninjurious to the organiza-

tion of such animals as people the earth at tho
present time. Sulphurous or sulphuric acid
vapours, too, occurring more frequently and
much more abundantly ihea than now, occa-
sioned the destruction of the inhabitants of the
inland waters — mollusca and numerous genera
of fishes, as well as the formation of the strange-
ly-twisted beds of gypsum which have often
apparently been shaken by earthquakes.

Under precisely similar physical relations
there were further thrown out from the bosom
of the ground various gases and liquids, mud,
and, from the eruption-cones of volcanoes,
which are but a species of intermitting springs,
streams of molten earths(^"*). All these mat-
ters owe their temperature and the nature of
their chemical constitution to the place of their
origin. The mean temperature of ordinary
springs is lower than that of the atmosphere
of the place where they appear, when the wa-
ter is derived from high levels ; their tempera-
ture increases with the depth of the strata with
which they come in contact at their origin.
The numerical law of this increase has been
stated above. The mixture of the waters which
come from the mountain elevations and from
the depths of the earth, renders the position of
the isogeothermal lines(^'*), or Hues of like in-
ternal heat of the earth, difficult of determina-
tion, when the conclusion has to be come to
from the temperature of springs as they rise.
So, at least, did I and my friends find it in some
experiments which we made in Northern Asia.
The temperature of springs, which has been so
constant an object of physical investigation for
the last half century, depends, like the height of
the line of perpetual snow, on numerous and
highly complex causes. It is a function of the
temperature of the stratum in which they have
their origin, of the capacity for heat of the ground,
and of the quantity and temperature of the at-
mospheric or meteoric water that falls(*"),
which last, again, according to the mode of its
origin, differs in its temperature from that of
the lower strata of the atmosphere(i''^).

Gold springs, as they are called, can only give
the mean temperature of the air if unmixed
with water that is rising from great depths, or
that is descending from considerable heights,
and when they have flowed for a very long way
under the surtace of the earth — in our latitudes
from 40 to 60 feet, in the equinoctial zone, ac-
cording to Boussingault, one foot(^^*). These
depths are those, in fact, of the stratum of earth
in which, in the temperate and torrid zone re-
spectively, the point of invariable temperature
begins, in which the hourly, diurnal, or month-
ly variations in temperature of the air are no
longer perceived.

Hot springs burst out of the most diversified
mineral strata ; the hottest of all the perma-
nent spnngs which have yet been observed,
and which I myself discovered, flow remote
from all volcanoes. I here refer to the Aguas
calientes de las Trincheras, between Puerto
Cabello and New Valencia, and to the Aguas
de Comangillas, near Guanaxuato in Mexico.
The first spring, issuing from granite, indicated
90-3° C. ; the second, which breaks from basalt,
shewed 96-4° C. The depth of the source of
water of these temperatures, from what we
know of the law of increase of temperature in

HOT SPRINGS.— MUD VOLCANOES.

67

the interior of the earth, must probably be about
6700 feet (more than half a geographical mile).
If the cause of the heat of thermal springs, as
well as of active volcanoes, be the universally
diffused heat of the earth, then would mineral
species produce an effect only through their ca-
pacity for, and their power of conducting heal.
The hottest of all the permanent springs, those,
namely, from 95« to 97° C. (204° to 207-6° F.),
it is remarkable, are the purest, are those that
contain the smallest quantity of mineral matter
in solution. Their temperature appears on the
whole to be less permanent than that of springs
between 50° and 74° C, the invariableness of
which, both in regard to temperature and min-
eral impregnation, has been maintained so won-
derfully, within the confines of Europe at least,
during the last fifty or sixty years, i. e, since ac-
curate thermometrical observations and chem-
ical analyses were made. Boussingault found
that the thermal springs of las Trincheras had
risen in temperature in the course of twenty-
three years (from 1800, when my journey was
performed, to 1823), from 93-3° to 97° C.(^'5).
This very smoothly flowing spring is conse-
quently at this time 7° C. higher in tempera-
ture than the intermitting Geyser and Strokr,
the temperature of which has been lately very
carefully ascertained by Krug of Nidda. One
of the most remarkable proofs of the origin of
these hot springs being due to the percolation
of cold meteoric water into the interior of the
earth, and its contact there with a volcanic fo-
cus, was presented in the preceding century in
connection with the volcano of Jorullo in Mex-
ico, which was unknown to geography till after
my South American journey. When this mount-
ain suddenly made its appearance in September,
1759, rising to a height of 1580 feet above the
surrounding level, the two small streams, Rios
de Cuitimba y de San Pedro disappeared ; but
by and by they made their appearance again,
under the dreadful shocks of an earthquake, as
hot springs. In 1803 I found their temperature
65-8° C.

The springs of Greece still flow apparently
in the same places as they did in the times of
Hellenic antiquity. The source of Erasinos,
two leagues south of Argos, on the declivity of
Chaon, is even mentioned by Herodotus. At
Delphi, the Cassotis, under its name of Stream,
of St. Nicholas, still rises to the south of the
Lesche, and flows under the Temple of Apollo ;
the Castalia, too, at the foot of the Phaedriadae,
and the Pirene at Acrocorinth, are there, as
well as the hot baths of ^depsum in Cubcea,
in which Sulla bathed at the time of the Mithri-
datic war(^^«). I gladly adduce these particu-
lars, because they forcibly remind us how, in a
country exposed to earthquakes so frequent and
so violent, the interior of our planet has been
able to preserve its fashion for 2000 years at
least ; the small, branching, and open fissures
that convey the water of these springs have not
altered. The Fontaine jaillissanle of liillers in
the department of the Pas de Calais, was bored
in the year 1126, and ever since then has the
water flowed uninterruptedly to the same height,
and in the same quantity ; the excellent geog-
rapher of the Caramanian coasts, Captain Beau-
fort, moreover, observed the same flame, fed by
a stream of inflammable gas, which escapes in

the district of Phaselis, which Pliny(^") de-
scribes as the flame of Chimaera in Lycia.

The observation made by Arago in 1821, that
the deeper Artesian wells are the warmer(^^^),
was the first means of throwing a great light
I upon the origin of thermal springs, and led to
] the discovery of the law of the increase of the
temperature of the earth according to the depth.
It is remarkable, and only noticed in very re-
cent times, that St. Patricius("'), probably bish-
op of Pertusa, was led to a very correct view
of the phenomenon which presented itself in
the appearance of the hot springs near Carthage
at the end of the third century. When ques-
tioned as to the cause of the boiling hot water
which poured out from the earth, he answered :
" Fire is nourished in the clouds and in the in-
terior of the earth, as Etna, and another mount-
ain in the neighbourhood of Naples, inform you.
The subterranean waters rise as through sy-
phons; and the cause of the heat of hot springs
is this : the waters that are more remote from
the subterraneous fire show themselves colder ;
those that flow in closer proximity to the fire,
warmed by it, bring an insupportable heat to
the surface which we inhabit."

As earthquakes are frequently accompanied
by eruptions of water and watery vapour, so do
we perceive in the volcanoes that pour out mud
a transition from the alternating phenomena
I presented by jets of vapour and thermal springs
I to the grand and destructive activity of the
mountains that vomit lava. If these, as springs
of melted earths, produce volcanic rocks, so do
the thermal springs that are charged with car-
bonic acid and sulphurous gas [and earthy mat-
ters], produce by incessant precipitation either
horizontal beds of limestone (travertin), or they
form conical hillocks, as in the north of Africa
(Algeria), and the Baiios of Caxamarca, on the
western declivity of the Peruvian Andes. In
the travertin of Van Dieman's Land, not far
from Hobart Town, they are contained, accord-
ing to Mr. Charles Darwin, the remains of an
extinct flora. By lava and travertin, two spe-
cies of rock the production of which goes on
under our eyes, we here indicate the grand an-
titheses in geognostical relations.

Mud volcanoes (Salsen) deserve a greater
share of attention than geologists have hitherto
bestowed upon them. The extent of the phe-
nomenon has been overlooked, because in the
two states in which it presents itself to us, the
one of repose is that which has been principal-
ly dwelt upon, and in this state of repose mud
volcanoes often continue for centuries. The
production of mud volcanoes is accompanied by
earthquakes, subterranean thunder, the eleva-
tion of a whole district of country, and the
eruption of flames, which rise high, but last only
for a short time. When the mud volcano of
Iskmali made its appearance in the peninsula of
Abscheron, eastward from Baku, on the Cas-
pian Sea (on the 27th of November, 1827),
flames burst forth, and blazed up to an extra-
ordinary height for a period of three hours ; for
the next succeeding twenty hours they scarcely
rose three feet above the surface of the crater
that discharged the mud. The column of flame
mounted to such a height near the village of
Baklichi, westward from Baku, that it was seen

MUD VOLCANOES.— VOLCANOES.

at the distance of six [German] miles. Great
blocks of stone, torn from their foundations be-
neath, were scattered widely around. Similar
blocks are observed about the now slumbering
mud volcanoes of Monte Zibio, near Sassuolo,
in the north of Italy. The second state, or
that of activity, has continued for 1500 years
in the mud volcano of Girgenti (Macalubi), in
Sicily, which is described by the ancients.
Many conical hillocks of 8, 10, and even 30
feet high, though the height as well as the form
of these varies at different times, are there seen
arranged near one another. From the superior
very small basin, which is full of water, along
with periodic escapes of gas, there are periodic
streams of clayey mud discharged. The mud
of these volcanoes is generally cold, but oc-
casionally, as at Damak, in the province of
Samarang, island of Java, it is of high tem-
perature. The gases, which escape with a
rushing noise, are also of different kinds — hy-
drogen gas, mixed with naphtha, carbonic acid,
and, as Parrot and I ascertained (in the penin-
sula of Taman and the South American Vol-
cancitos de Turbaco), almost pure nitrogen
gas(^«°).

Mud volcanoes, after the first forcible out-
burst of flame, which perhaps is not common to
all in the same measure, present the observer
with a picture of sn activity of the interior of
the earth that proceeds incessantly but feebly.
The communication with the deep strata in
which a high temperature prevails is speedily
interrupted again ; and the cold discharges of
mud volcanoes seem to indicate that the seat
of the phenomenon, in its state of continuance,
cannot be very remote from the surface. The
reaction of the interior of the earth upon its
outer crust is exhibited in a very different de-
gree of force in the proper volcanoes, or burn-
ing mountains ; in other words, in those points
of the earth where a permanent communica-
tion, or, at all events, a communication that is
renewed from time to time, is established be-
tween the surface and the deep focus of igni-
tion. We must carefully distinguish between
more or less exaggerated volcanic phenomena,
such as these : Earthquakes, hot springs and
jets of steam, mud volcanoes, the appearance
of unopened dome-shaped trachytic mountains,
the opening of these mountains, or the upheaval
of basaltic beds as craters of elevation, the
final rise of a permanent volcano within the
upheavement crater itself, or amongst the frag-
ments of its previous constitution. At differ-
ent times, along with different degrees of ac-
tivity and force, permanent volcanoes throw
out jets of aqueous vapour, acids, glowing
ashes and scoriae, and, when the resistance can
be overcome, fiery streams of melted earthy
matters.

As a consequence of a great but local mani-
festation of force in the interior of our planet,
elastic vapours raise either single parts of the
crust of the earth into dome-shaped, unopened
masses of felspathic trachyte and dolerite (Puy
de Dome and Chimborazo) ; or the upheaved
strata are broken through, and inclined out-
wards in such wise that upon the opposite inner
aspect a steep rocky edge is produced. This
edge then becomes the boundary of an upheave-
ment crater. When this has risen from the

bottom of the sea, which does not by any means
happen in every case, it then presents the
whole of the characteristic physiognomy of the
upheaved island. This is the origin of the cir-
cular form of Palma, which Leopold von Buch
has described so carefully and so ably, as well
as of Nisyros, in the .^gean Sea("^). Occa-
sionally, one half the ring-like edge is destroy-
ed, and in the bay which the sea that has flow-
ed in then forms, the social coral insects es-
tablish themselves, and produce their cellular
dwellings. Craters of elevation on continents
are also frequently found filled with water,
when they contribute to beautify the landscape
in an extraordinary and quite peculiar manner.
Their origin is not connected with any spe-
cial mountain formations ; they break out in
basalt, trachyte, and leucitic porphyry (Somma),
or in doleritic mixtures of augite and labrador.
Hence the very dissimilar natures and external
forms of this kind of crater edge. " No erup-
tive phenomena take place from such bounda-
ries ; through them there is no permanent chan-
nel of communication established with the in-
terior, and it is only very rarely that traces of
still active volcanic power are discovered in
the precincts or within the circuit of such cra-
ters. The force competent to bring about such
important effects must long have gathered it-
self together, and gained strength in the inte-
rior, before it could overcome the resistance of
the superincumbent masses. On the formation
of new islands, it throws up granular rocky
masses, and conglomerates (layers of tufa full
of marine plants) above the level of the sea.
Compressed gases escape through the crater
of elevation ; but a mass of such magnitude
thus upheaved sinks down again, and closes
forthwith the openings which are only formed
for such manifestations of force. No volcano
is produced"(i«2)

A proper volcano only arises where a per-
manent connection is established between the
interior of the earth and the atmosphere. Here
the reaction of tMfe interior upon the exterior
proceeds for lengthened periods. It may, as
in the case of Vesuvius (Fisove)^^^ be inter-
rupted for centuries, and exhibit itself anew
with renovated vigour. In the time of Nero it
was already customary, in Rome, to rank .^tna
among the number of the gradually-expiring
volcanic mountains(^^*) ; JSlian, indeed, at a
later period, maintained that the seamen began
to see the sinking summit at a less distance on
the high seas than formerly(^^*). Where the
evidence of the eruption, I might say the old
scaffolding, has been perfectly preserved, the
volcano shows itself rising from a crater of el-
evation ; there a high rocky wall, a rampart of
greatly-inclined strata, surrounds the isolated
cone in the manner of a circus. Sometimes
there is not a trace of this circus-like inclosure
visible, and the volcano, not always conical in
figure, then arises as an elongated ridge imme-
diately from the elevated platform. This is
the case with Pichincha, at the foot of which
stands the city of Quito.

As the nature of mountain masses, in other
words, the combination or grouping of simple
minerals into granite, gneiss, and mica-slate,
into trachyte, basalt, and dolerite, independent-
ly of present climates, and under the most dis-

VOLCANOES.

69

similar zones, is still the same ; so do we ev-
erywhere observe the same laws of formation
proclaiming themselves in the realm of inor-
ganic nature, laws according to which the
strata of the crust of the earth stand in a cer-
tain relationship to one another, under the in-
fluence of elastic forces, and break through one
another as dykes. This recurrence of the same
phenomena is particularly striking in volcanoes.
When the navigator, among the islands of dis-
tant seas, finds himself surrounded by palms
and strange forms of vegetation, and no longer
sees the same stars, in the individualities of
the landscape he still traces Vesuvius, the
dome-shaped summit of Auvergne, the craters
of elevation of the Canaries and Azores, the
fissures of eruption of Iceland repeated and re-
flected ; a glance at the attendant of our planet,
the moon, generalizes still farther the analogy
of formation here adverted to. In the maps of
the moon, drawn from the image reflected in
powerful telescopes, in our satellite, without
atmosphere and without water, we can distin-
guish vast craters of elevation, which surround
conical mountains, or support them on their
circular walls : unquestionable effects of the
reaction of the interior of the moon upon her
exterior, aided by the influence of diminished
gravity.

If in many languages volcanoes are very
properly designated Burning Mountains, it
would still be a great mistake to suppose that
they were produced by any gradual accumula-
tion of the streams of lava that have flowed
from them ; their origin appears to be much
more generally the consequence of a sudden
upheaval of tenacious masses of trachyte or
augitic rock, including Labrador spar. The
measure of the upheaving force reveals itself
in the height of the volcano ; and this is so dif-
ferent, that in one case it is a mere hillock (as
in Cosima, one of the Japanese Kuriles), in an-
other it is a cone that rises to a clear elevation
of 18,000 feet. It has seemed to me as if the
relative height had a great influence upon the
frequency of the eruptions ; as if these were
much more common in the lower than in the
loftier volcanoes. I will call attention to the
following series: Stromboli (2,175 feet high),
Guacamayo, in the province of Quiros, which
thunders almost every day (I have frequently
heard it in Chillo, near Quito, at a distance of
22 miles), Vesuvius (3,637 feet high), ^tna
(10,200 feet high), the Peake of Teneriffe
(11,424 feet high), and Cotopaxi (17,892 feet
high). If the focus of these several volcanoes
be at the same depth below the surface, a great-
er force will be required to raise the molten
masses to a 6 or 8 times higher level. Whilst
the lowly Stromboli (Strongyle) has laboured
restlessly, at least since the times of the Ho-
meric traditions, and serves as a light-house
to the Tyrrhenian Sea, guiding the seaman with
its fiery signal on his course, the more lofty
volcanoes are characterized by lengthened pe-
riods of repose. The eruptions of the greater
number of the colossal volcanoes that crown
the Andes, occur at intervals almost of a cen-
tury apart : where exceptions to this rule have
been observed — and I long ago directed atten-
tion to them — they may probably be connected
with the circumstance, that the communication

between the volcanic focus and the crater oi
eruption is not, cannot be conceived to be,
equally or permanently free in every volcano
at all times. In the less elevated volcanoes
the channel of communication may be closed
for a season ; so that their eruptions become
rarer, without their being, on this account, any
nearer to extinction.

With the consideration of the relation be-
tween the absolute heights of volcanoes and
the frequency of their activity, in so far as
this is externally visible, the place at which
the lava flows out is closely connected. Erup-
tions from the crater are extremely rare in the
case of many volcanoes ; they generally occur
from lateral fissures (as noticed by the celebra-
ted historian, Bembo, in the 16th century, whilst
yet a youth), at places where the flanks of the
uplifted mountain, in consequence of their for-
mation and inclination, offer the least amount
of resistance(^^*). Upon these fissures cones
of eruption are occasionally raised. The larger
of these are of such dimensions that they are
often erroneously designated by the title of new
volcanoes ; ranked side by side, they show the
direction of a fissure which has again become
closed ; the smaller ones frequently occur in
groups, thickly set together, and cover whole
districts, as it were with bell-shaped, or bee-
hive like, elevations. To the latter class be-
long the hornitos of Jorullo(^^^), and the cone of
eruption of Vesuvius of October, 1822, of the
volcano of Awatscha, according to Postels,
and of the lava field near the Baidare mount-
ains, in the peninsula of Kamtschatka, accord-
ing to Erman.

When volcanoes do net rise free and isola-
ted from a plain, when, on the contrary, they
are surrounded by table-lands from 9 to 12,000
feet high, as in the double chain of the Andes
of Quito, this circumstance may very well give
rise to the fact, that the most violent eruptions,
when red-hot ashes and scoriae are thrown out
with detonations that are heard for hundreds
of miles around, are never accompanied with
streams of lava<'^^*). This is the case with
the volcanoes of Popayan, of the lofty plains of
Los Pastes, and of the Andes of Quito ; the
single volcano of Antesana, among the latter,
perhaps excepted.

The height of the cone of ashes, and the di-
mensions and form of the crater, are the ele-
ments in the figure of volcanoes which more
particularly impress upon each of them an in-
dividual character; but both of these elements,
both the cone and the crater, are perfectly in-
dependent of the magnitude of the whole mount-
ain. Vesuvius is not one-third of the height of
the Peake of Teneriffe, yet its cone of ashes
forms one-third of the whole height of the
mountain, whilst the cone of the Peake is only
one twenty-second of the entire elevation. In
the case of another volcano of much greater
height than the Peake, that of Rucu-Pichincha,
namely, the relations come nearer to those of
Vesuvius. Of all the volcanoes which I have
seen in either hemisphere, Cotopaxi is that of
which the conical form is the most regular and
beautiful. A sudden melting of the snow of
its ashy cone indicates the proximity of an
eruption. Before there is even any smoke
visible in the thin strata of the atmosphere

70

VOLCANOES.

that surround the summit and the crater's
mouth, the walls of the ashy cone are some-
times heated through, when the entire mount-
ain presents the most threatening and ill-omen-
ed aspect of inky black.

The crater which, except in very rare cases,
occupies the summit of the volcano, forms a
cauldron-like, and often accessible valley, whose
bottom is subject to incessant changes. The
greater ar less depth of the crater is, in many
volcanoes, an indication of the proximity or re-
moteness of an eruption. In the cauldron-like
crater extensive fissures open and close again
alternately ; through these vapours of various
kinds find vent, or small rounded fiery throats,
filled with molten matters, are formed upon
them. The ground rises and falls, and on it
are piled hillocks of ashes and cones of erup-
tion, which occasionally rise high above the
edges of the crater, and give the volcano its
characteristic physiognomy for years ; but on
the occurrence of fresh eruptions, they sink
suddenly down, and disappear. The openings
of these cones of eruption, which rise from the
floor of the crater, must not, as is too frequent-
ly done, be confounded with the crater itself,
which encircles them. When the crater is in-
accessible, from its vast depth, and the perpen-
dicular inward slope of its sides, as in the case
of Rucu-Pichincha (14,946 feet high), one can
still look down from the edges, upon the sum-
mits of the monticules which rise within the
cauldron-like crater, partially filled with sul-
phureous vapours. A more wonderful or grand-
er natural prospect I have never enjoyed. In
the interval between two eruptions, the crater
of a volcano may exhibit no luminous phe-
nomenon, but merely open fissures and jets of
watery vapour ; or hillocks of ashes that can
be approached without danger, are found upon
its scarcely heated bottom. These often grati-
fy the wandering geologist, without making
him run any risk, by casting out glowing mass-
es, which fall on the edges of the cone of sco-
riae, their appearance being regularly announ-
ced by slight, and entirely local shocks — earth-
quakes on a small scale. Lava occasionally
flows from open fissures, or small fiery gorges,
into the crater itself, without bursting through
its walls, or overflowing its edges. But if it
does break through, the molten spring general-
ly flows smoothly, and in such a determinate
direction, that the great cauldron-like valley,
called the crater, can still be visited during the
period of the eruption. Without a particular
description of the conformation, and also of
the normal structure of burning mountains,
phenomena cannot be rightly comprehended
which have been distorted by fantastical de-
scriptions, and the various significations at-
tached to the words crater, volcano, and cone ;
or, rather, to the indefinite and indeterminate
use of these words. The edges of the crater
sometimes show themselves much less liable
to change than might be expected. A compari-
son of De Saussure's measurements with my
own, yields the remarkable result, in connection
with Vesuvius at least, that the north-west
edge of the volcano, the Rocca del Palo, may
be regarded as having remained for forty-nine
years (1773-1822) almost without change in its

elevation above the level of the sea. Any dif- 1 and two men.

ference that appears may be looked on as with
in the possible errors of measurement(*8').

Volcanoes which lift their summits far above
the limits of eternal snow, like those of the
Andes, present a variety of peculiar features.
The sudden melting of the snow in the course
of an eruption, not only occasions destructive
floods, torrents in which heaps of smoking ash-
es are floated away on blocks of ice ; but the
accumulation of ice and snow goes on produ-
cing its influence uninterruptedly, and by fil-
tration into the trachytic rocks, even whilst
the volcano is perfectly quiescent. Caverns
are thus gradually produced on the declivities
or at the foot of the burning mountain, and
these become subterraneous reservoirs of wa-
ter, which communicate in various ways, and
by narrow mouths, with the Alpine rivulets of
Quito. The fishes of these Alpine streams
multiply greatly, particularly in the gloom of
the caverns ; and then, when the earthquakes
come, which precede all eruptions of volcanoes
in theAndes, and the whole mass of the mount-
ain is shaken, the subterraneous caverns at
once give way, and pour out a deluge of water,
fishes, and tufaceous mud. This is the singu-
lar phenomenon which the presence of the
Pimelodes Cyclopum(^'<'), the Prenadilla of the
inhabitants of the lofty plains of Quito, attests.
When, in the night between the 19th and 20th
of June, 1698, the summit of Carguairazo, a
burning mountain 18,000 feet high, crumbled
together, so that no more than two enormous
rocky horns of the crater's edge remained, the
country for nearly two square miles was deso-
lated with liquid tuflf and argillaceous mud
(lodazales) inclosing dead fishes. So also was
the putrid fever of the mountain town, Ibarra,
to the north of Quito, which occurred seven
years before, ascribed to an eruption of fish
from the volcano Imbaburu.

Water and mud which, in the volcanoes of
the Andes, do not pour down from the crater
itself, but from cavities in the trachytic mass
of the mountain, ought not, consequently, in
the strict sense of the phrase, to be reckoned
among the number of proper volcanic phenom-
ena. They are only mediately connected with
the activity of volcanoes, nearly in the same
measure as the irregular meteorological pro-
cess, which, in my earlier writings, I have spo-
ken of under the title of the Volcanic storm.
The hot, watery vapour which rises from the
crater, and mingles with the atmosphere during
the eruption, forms a cloud as it cools, with
which the column of ashes and fire, many thou-
sand feet in height, is surrounded. So sudden
a condensation of vapour, and the production
of a cloud of enormous superficial dimensions,
increase the electrical tension, as Gay Lussac
has shown. Forked lightnings dart from the
column of ashes, and the rolling thunder of the
volcanic storm is then plainly distinguishable
from the rumbling in the interior of the mount-
ain. This was well observed towards the end
of the eruption of Vesuvius in the month of
October, 1822. The lightning, which proceed-
ed from the volcanic steam-cloud of the Katla-
gia burningrmountain in the Island of Iceland,
according to Olaffen's account, upon one occa-
sion (17th October, 1755), killed eleven horses

VOLCANOES.

71

Having now, in our physical delineation, por-
trayed the general structure and dynamic ac-
tivity of volcanoes, we have still to cast a
glance at the material diversity of their prod-
ucts. The subterraneous forces separate old
combinations of elements, in order to bring
about new combinations ; they farther, and at
the same time, put the matters transformed or
changed into motion, so long as they are dis-
solved by heat and moveable. The solidifica-
tion of the tenaciously or more limpidly fluid
and moveable mass, under different degrees of
pressure, appears to be the principal cause de-
termining diflferences in the structure of Plu-
tonic and volcanic rocks or mineral species.
The mineral mass which has flowed in a liquid
state from a volcanic opening — a molten min-
eral spring — is called lava. Where several
streams of lava have encountered and several-
ly restrained each other in their course, they
spread out and fill extensive basins, where they
cool into stratified beds. These few points
comprise the whole of the general features in
the productive activity of volcanoes.

Minerals which merely break through a vol-
cano often remain enclosed in the products of
its igneous activity. I have, for instance, seen
angular masses of syenite, rich in felspar, con-
tained in the black augitic lava of the Mexican
volcano, Jorullo ; but the masses of dolomite
and granular limestone, which contain beauti-
ful druses or cavities lined with crystallized
minerals — vesuviane and garnets, mejonite,
nepheline, and sodalite — are not ejections of
Vesuvius : " they rather belong to a very ex-
tensive formation, tuff-strata, older than the
upheaval of Somma and Vesuvius, and are
probably products of submarine volcanic influ-
ences, at great depths below the surface"(^'^).
Among the products of our present volcanoes
there are five metals : iron, copper, lead, arse-
nic, and selenium, discovered by Stromeyer in
the crater of Volcano. Through the smoking
fumaroles,- the chlorides of iron, copper, lead,
and ammonium, are sublimed ; iron-glance(^"),
and common salt (the latter often in large quan-
tities), are seen filling veins in recent streams
of lava, or covering fresh fissures of the cra-
ter's edges.

The mineral composition of lavas differs ac-
cording to the nature of the crystalline rock of
which the volcano consists ; according to the
height of the point at which the eruption takes
place — as it is near the foot of the mountain,
or in the vicinity of the crater ; and according
to the temperature of the interior. Vitreous
volcanic products, obsidian, pearlstone, or pum-
ice, are entirely wanting in some volcanoes,
and in others are only ejected from the crater
itself, or from some considerably elevated point.
These important and complex relations can
only be ascertained by careful crystallographic
and chemical researches. My companion in
my Siberian journey, Gustavus Rose, and after
him, Herman Abich, have begun, with much
acumen and success, to throw clear light upon
the compact texture of such a variety of vol-
canic minerals.

The greater portion of the vapour that rises
is pure steam or watery vapour. Condensed
and flowing away as a rivulet, it is used by the
goatherds of the island of Pantellaria. The

stream which was seen flowing from a latera
fissure in the crater of Vesuvius on the morn-
ing of the 26th of October, 1822, and was long
regarded as hot water, was found by Monticelli
to be dry ashes, which poured forth like drift-
sand ; it was lava ground to dust by attrition.
The appearance of ashes, however, which dark-
en the air for hours, and even for days, and
which, by adhering to the leaves, become so
destructive to vineyards and olive trees, in
their columnar ascent, borne up by vapours,
indicate the termination of every great erup-
tion. This is the magnificent spectacle which
the younger Pliny describes in the celebrated
letter to Cornelius Tacitus, and which he com-
pares, in point of shape, to a lofty-branched
and shady pine tree. What has been descri-
bed as flame in the eruption of ashes, is cer-
tainly not, any more than the light of the glow-
ing red cloud that floats above the crater, to
be ascribed to hydrogen gas on fire. It is rath-
er the reflection of light from the upheaved
molten masses ; sometimes, too, it may be the
light from the depths of the fiery gorge cast
upon the ascending vapours and reflected by
them. But as to what those flames may be,
which have been occasionally seen ever since
Strabo's time during the activity of volcanoes
on the coast, and that have risen from the bo-
som of the sea immediately before the uphea-
val of a volcanic island, I do not pretend to de-
cide.

If we are asked what it is that burns in vol-
canoes, what it is that produces the heat which
melts and mixes the earths and metals, and
even imparts an elevated temperature, for ma-
ny years, to streams of lava of great thick-
ness 1(^") there is always the presumption
that, as in the case of the coal fields which
catch fire and go on burning, volcanoes. must
necessarily be connected with the presence of
certain substances calculated to support com-
bustion. According to the various phases of
chemical science, we have had bitumen, iron
pyrites, the moist contact of finely divided sul-
phur and iron, pyrophoric substances, and the
metals of the alkalies and earths, assigned as
the cause of volcanic phenomena in their high-
est intensity. The great chemist to whom we
are indebted for our knowledge of the most
combustible of the metallic substances. Sir
Humphrey Davy, has himself renounced his
bold chemical hypothesis in the last volume
he published — " Consolations in Travel, and
the Last Days of a Philosopher" — a work that
excites painful feelings of regret in the mind
of the reader. The great mean density of the
earth (5-44), compared with the specific gravi-
ty of potassium (0 865), of sodium (0972), and
of the metals of the earths (12), the absence
of hydrogen in the gaseous emanations of the
fissures of volcanoes, and the streams of lava
that have not yet cooled, many chemical con-
siderations, in a word, rise up in opposition to
the earlier conjectures of Davy and Ampere("*).
Were hydrogen evolved during eruptions of
lava, how enormous must its quantity prove in
cases where, from the low level of the point
whence the eruption flows, the outpouring mass
spreads over many square miles of surface, and,
dammed up in its course, acquires a thickness
of several hundred feet ; as happened in the

72

VOLCANOES.

remarkable eruption at the foot of the Skaptar-
Jokul in Iceland (11th of June to 3d of August,
1783), which has been described by Mackenzie
and Soemund Magnussen. The same difficul-
ties present themselves in connection with the
small quantities of azote that are evolred,
when the atmospheric air is conceived as pen-
etrating by the crater, or, as such an act has
been figuratively expressed, when the earth is
imagined as inspiring. So general, so deeply
effective, and, in reference to the interior of
the earth, so extensive an action as that of
volcanoes, cannot well have its source in the
chemical affinities, in the contact of individual
and only locally distributed substances. Mod-
ern geognosy prefers seeking for this source
in the temperature increasing with the depth
under every parallel of latitude, in the great in-
ternal heat of the globe, which is due to its
original consolidation, to its formation in space,
to the spherical contraction of vaporous matter
circulating in an elliptical orbit. Beside posi-
tive knowledge, stand Conjecture and Opinion.
A philosophical science of nature strives to rise
beyond the limited requirements of a bare de-
scription of nature. It consists not, as we
have several times reminded the reader, in the
barren accumulation of isolated facts. The cu-
rious, the inquiring spirit of man, must be suf-
fered to make excursions from the present into
the past, still to surmise what cannot be posi-
tively known, and to revel in the old, and, un-
der various shapes, ever recurring myths of ge-
ognosy. If we consider volcanoes as irregular
intermitting springs, which pour out a liquefied
mixture of oxidized metals, alkalies and earths,
that flow smoothly, silently enough, once the
mixture, uplifted by the vast force of com-
pressed vapour, finds a vent, we are involunta-
rily reminded of Plato's geognostical phanta-
sies, according to which hot springs, as well
as all the varieties of volcanic fiery streams,
are effusions of Periphlegethon, a cause uni-
versally present in the interior of the globe(^95).
Volcanoes, in their mode of distribution over
the surface of the earth, independently of all
climatic differences, are well and characteris-
tically referred to two classes, viz. : Central
volcanoes and Linear volcanoes, " according
as a central and common point of eruption for
many foci all around is established, or as sev-
eral vents extending in one direction, and at
no great distance from each other, are formed,
along the course apparently of a lengthened
fissure. Linear volcanoes, again, are of two
kinds : they either rise as insulated cones from
the bottom of the sea, and are accompanied
usually on one side by a primitive mountain
mass running in the same direction, the foot
of which they seem to indicate ; or they stand
upon the crest of the mountain chain, and form
its loftiest summits"(i"). The Peake of Ten-
eriflfe, for example, is a central volcano, the
middle point of the volcanic group to which
the outbreaks of Palma and Lancerote belong.
The lengthened chain of the Andes, which runs
like a wall from Southern Chili to the north-
west coasts of America, here singly, there in
two and three parallel lines, connected at in-
tervals by narrow transverse yolks, presents
an instance upon the grandest scale of the oc-
currence of linear volcanoes on dry land. The

vicinity of active volcanoes in the line o( the
Andes is proclaimed by the sudden appearance
of certain species of rocks, such as dolerite,
melaphyre, trachyte, andesite, and dioritic por-
phyry, which separate the so-called primitive
rocks, as well as the schistose and sandstone
transition strata and the tertiary or flcetz for-
mations. A phenomenon of this kind constant-
ly recurring, begot a persuasion in my mind at
an early period, that these sporadic rocks had
been the seat of volcanic phenomena, and
had been determined by volcanic eruptions.
At the foot of the great Tunguragua, near Pe
nipe, on the banks of the Rio Puela, I for the
first time, and distinctly, saw a mica schist,
which rested upon granite, broken through by
volcanic rocks.

The linear volcanoes of the New World,
where they lie near to one another, are partial-
ly in a state of reciprocal dependance ; it i*9t-_
even obvious that the volcanic activity has ^^ ^
been gradually advancing for centuries in par-
ticular determinate directions — in the Province
of Quito, for example, from north to south("^>.
The hearth or focus itself lies under the whole
of the elevated lands of this province ; the par-
ticular openings by which communications are
established with the atmosphere constitute the
mountains which we designate by special
names, such as Pichincha, Cotopaxi or Tun-
guragua, and which, by their grouping, as well
as by their height and form, present the grand-
est and most picturesque prospect that is any-
where to be seen within a small compass in a
volcanic country. As the outermost members
of such groups of linear volcanoes are connect-
ed with one another by subterraneous commu-
nications, as multiplied experience shows, this
fact reminds us of Seneca's old and truthful
sentence(i^^), " that the burning mountain is
but the passage to deeper-lying volcanic for-
ces." In the Mexican highlands, likewise, the
volcanoes (Orizaba, Popocatepetl, Jorullo, Co-
lima), which I have shown(^^') all to lie in one
direction, between 18° 59' and 19° 12' N. lati-
tude, appear to indicate a transverse fissure
extending from sea to sea, and to be mutually
dependant. The volcano of Jorullo broke out
on the 29th of September, 1759, exactly in this
direction, upon the same transverse fissure,
and rose to a height of 1580 feet above the sur-
rounding level. This mountain never threw
out but one stream of lava ; precisely like Epo-
meo in Ischia, in the year 1302.

But if Jorullo, distant as it is some German
miles from every active volcano, be, in the
strictest sense of the word, a new mountain,
nevertheless it must not be confounded with
the appearance of the Monte Nuovo near Poz-
zuolo (19th September, 1539), which is to be
reckoned among the number of upheavement
craters. I have already said that it were more
in conformity with nature to assimilate the
eruption of the newly produced Mexican vol-
cano with the upheaval of the hill of Methone
(now Methana), upon the peninsula of Traezene.
This upliftment, described by Strabo and Pau-
sanias, has led one of the most imaginative of
the Roman poets to propound views which
agree in a very remarkable manner with those
of modern geognosy : " A tumulus is seen at
Traezene, rugged, and without wood ; once a

VOLCANOES.

7 J

level, now a mountain ; the vapours pent up
in dark caverns sought in vain for a crevice of
escape. They swelled the expanding soil un-
der the force of the compressed vapour, like a
bladder filled with air ; it swelled like the skin
of a two-horned goat. The upheavement re-
mains upon the spot ; the high, uplifted hill be-
came hardened in the course of time into a
naked rocky mass." So picturesquely, and,
also, as analogous appearances lead us to be-
lieve, so truly, does Ovid describe the grand
natural incident which occurred between Trae-
zene and Epidaurus, 282 years before the com-
mencement of our era, and therefore 45 years
before the volcanic separation of the island of
Thera (Santorin) from TherasiaC^o").

Of all the islands belonging to the series of
linear volcanoes, Santorin is the most impor-
tant. " It comprises in itself the entire history
of upheaved islands. For full two thousand
years, so long as history and tradition extend,
Nature has not ceased from her attempts to
form a volcano within the circuit of the crater
of elevation"(^°^)- Similar insular upheave-
ments, at almost regularly recurring intervals
of 80 or 90 years, are exhibited in the island of
St. Michael, one of the group of the Azores(""),
though here the bottom of the sea has not been
uplifted quite at corresponding points. The
island named Sabrina by Captain Tillard unfor-
tunately appeared at a time when the political
state of the maritime nations of the west of
Europe was little favourable to scientific inves-
tigations (30th Jan., 1811); so that this great
event did not attract the same degree of atten-
tion as was bestowed upon the island of Fer-
dinandea,* which appeared on the 2d of July,
1831, but soon fell to pieces again, between the
limestone coast of Sciacca and the purely vol-
canic Pantellaria in the Sicilian Sea(=^''=').

The geographical distribution of the volca-
noes which have continued active since the
historical epoch, their frequent situation by the
sea-shore, and on islands, to say nothing of the
recurrence, from time to time, of temporary
eruptions from the bottom of the sea, appears
at an early period to have begotten the belief,
that volcanic activity was connected with the
vicinity of the sea, and could not continue with-
out it. "^tna and the CEolian isles," says
Justin(='<'*), or, rather, Trogus Pompeius, whom
he copies, " have already been burning for many
centuries ; and how were this long continuance
possible, did not the neighbouring sea supply
food for the firel" To explain the necessity
for the neighbourhood of the sea, the hypothe-
sis of the penetration of sea- water to the hearth
of the volcano, i. e., to the deep-lying strata of
the earth, has in recent times been again pro-
posed. If I embrace all that occurs to me, de-
rived either from personal observation or from
carefully collected facts, it seems to me that
everything in this difficult inquiry depends upon
the way in which the following questions are
answered : Whether the undeniably large quan-
tities of watery vapour, which volcanoes emit,
even in their state of repose, be derived from
sea-water loaded with salts, or from sweet at-
mospheric water? Whether, with different

* The Graham Island of English geologists ; vide Lyell's
admirable Principles of Geology, vol. ii., p. 266. Sixth edit.,
Lond., 1840.— Te,

K

depths of the volcanic hearth (a depth, for ex-
ample, of 88,000 feet, at which the expansive
force of the vapour of water would be exerted
under a pressure of 2,800 atmospheres), the ex-
pansive force of the vapour engendered would
be competent to counterbalance the hydrostatic
pressure of the sea, and admit the access of its
water to the volcanic hearth, under certain
conditions 1(^''^) Whether the many metallic
chlorides, the appearance, indeed, of common
salt in the fissures of craters, and the admix-
ture of hydrochloric acid vapours with the wa-
tery vapour emitted, lead necessarily to the
conclusion, that the sea must have access to
the volcano 1 Whether the repose of the vol-
cano, be this temporary only, or final and com-
plete, depends on the stoppage of the channels
which previously conducted the sea, or the me-
teoric water, to the volcanic hearth 1 Whether
the absence of flame and of hydrogen gas — for
sulphuretted hydrogen belongs to the solfataras
rather than to the active volcanoes — is not
rather in open contradiction with the assump-
tion of any extensive decomposition of water 1
The discussion of physical questions of such
importance does not fall within the scope of a
Picture of Nature. Here we attach ourselves to
the narration of phenomena ; to facts in the geo-
graphical distribution of yet active volcanoes.
Now facts inform us, that in the New World,
three of these — JoruUo, Popocatepetl, and La
Fragua — are 20, 33, and 39 geographical miles
distant from the sea-shores, and that in central
Asia (and M. Abel-Remusat("^) first directed
the attention of geologists to the fact), there is a
great volcanic mountain chain, Thian-schan, or
the Celestial Mountains, with the lava-emitting
Pe-schan, the solfatara of Urumtsi, and the
burning mountain of Turfan (Ho-tscheu), the
several members of which are at nearly equal
distances — 370 to 382 geographical miles — from
the shores of the Icy Sea and of the Indian
ocean. The distance of Pe-schan from the
Caspian Sea is also full 340 geographical miles ;
and from the great lakes, Issikul and Balkasch,
it is 43 and 52 miles(="). It is farther remark-
able, that of the four great parallel mountain
chains — the Altai, the Thian-schan, the Kuen-
luen, and the Himalaya, which cross the conti-
nent of Asia from east to west — it is not the
Himalaya, or the chain that is nearest the
ocean, but the two minor chains, the Thian-
schan and the Kuen-luen, at the distance res-
pectively of 400 and 180 geographical miles
from the sea, that are found vomiting fire like
^Etna and Vesuvius, and producing ammonia,
like the volcanoes of Guatimala. The Chinese
writers describe, in unmistakable terms, streams
of lava, 10 Li long, as occurring in the eruptions
of flame and smoke which took place from Pe-
schan, and spread far and wide, in the 1st and
7th centuries of our era. *' Burning masses of
rock," say they, " flowed as thin as melted fat."
These few compressed facts, which have not
been sufficiently attended to, make it probable
that the vicinity of the sea, and the access of
sea-water to the burning focus, are not indis-
pensably necessary to the breaking out of sub-
terranean fires, and that coasts are only favour-
able to volcanic eruptions, because they form
the sides or edges of the deep sea-basin, which,
covered with strata of water, offers less resist-

74

CLASSES OF ROCKS.

ance, and lies many thousand feet lower, than
inland and more lofty countries.

The volcanoes that are active at the present
time, and that communicate permanently by
craters with the interior of the earth and the
atmosphere, became open at so late an epoch,
that the superior cretaceous deposits, and the
whole of the tertiary formations, were already
in existence when they arose. This is pro-
claimed by the trachytes, and also by the basalts,
which frequently form the walls of the up-
heavement craters. Melaphyres extend to the
middle tertiary strata ; but have already begun
to show themselves under the Jura formations,
when they appear breaking through the varie-
gated sandstone(*°8). The active volcanoes of
the present time, communicating with the air
by craters, must not be conlounded with those
older eruptions of granite, quartzose porphyry,
and euphotide, through open, but speedily-clo-
sed fissures (forming veins), which occur in the
old transition strata.

The extinction of volcanic activity is either
partial only, so that the subterranean fire finds
another vent in the same mountain chain ; or
it is total, as in Auvergne ; later examples are
supplied, in perfectly historical times, by the
volcano MosychlosC^"^), on the island dedicated
to Hephcestos, whose " upward flickering fiery
glow" was known to Sophocles, and by the
volcano of Medina, which, according to Burck-
hardt, threw out a stream of lava on the 2d
of November, 1276. Each stage of the volcan-
ic activity, from its first excitement to its ex-
tinction, is characterized by peculiar products :
first, by fiery scoriae, by trachytic, pyroxenic,
and vitreous lavas in streams, by scoriae and
tuff ashes, accompanied by the evolution of
large quantities of generally pure watery va-
pour ; at a later period as solfataras, when
there is an evolution of watery vapour mixed
with sulphuretted hydrogen and carbonic acid
gases ; lastly, when all has cooled, by exhala-
tions of carbonic acid gas alone. Whether that
singular class of burning mountains which dis-
charge no lava, but dreadful devastating streams
of hot water(2'°), loaded with burning sulphur,
and rocks ground down to powder — such, for
instance, as Galunggung, in the island of Java
— present us with what may be called a normal
condition, or only a certain transitory modifica-
tion of the volcanic process, will remain a ques-
tion undecided, until they have been visited by
geologists possessed at the same time of a
knowledge of modern chemistry.

Such is the very general view of volcanoes,
so important an element in the life of the earth,
which I have here endeavoured to throw to-
gether. It is based, in part, upon my own ob-
servations ; in the generality and comprehen-
siveness of its outlines, however, upon the la-
bours of my friend of many years, Leopold von
Buch, the greatest geologist of our age, who
was the first to recognize the intimate connec-
tion of volcanic phenomena, and their mutual
interdependence in regard to their actions alid
their relations in space.

The reaction of the interior of a planet upon
its outer crust and surface, as manifested in
the phenomena of volcanoes, was long consid-
ered as a mere isolated phenomenon, and pe-

culiar only with reference to the destructive
agency of its dark and subterraneous forces ; it
is but very lately, and greatly to the advantage
of that geology which is founded on physical
analogies, that the volcanic forces have begun
to be regarded as formative of new species of
rocks, and as transformative of older mineral
masses. Here, indeed, is the point already al-
luded to, where a more deeply-grounded doc-
trine of volcanoes in a state of activity, and ei-
ther casting out fire or vapour, leads us, in our
general Picture of Nature, by a double way,
the one to the mineralogical portion of geog-
nosy, or the doctrine of the structure and suc-
cession of the strata composing the crust of the
earth ; the other to the form and fashion of the
continents and groups of islands raised above
the level of the sea, or the doctrine of the geo-
graphical forms and outlines of the several por-
tions of the earth. Enlarged views of such an
enchainment of phenomena is a consequence
of the philosophical direction which the serious
study of geognosy has now so generally taken.
Greater perfection of the sciences leads, as in
the political improvement of mankind, to con-
nection and agreement, where there had for-
merly been separation and distinction.

When we class rocks or mineral masses not
according to differences in the form and ar-
rangement of their constituent particles, into
stratified and unstratified, schistose and massy,
normal and abnormal rocks, but look at the
phenomena of formation and transformation
which are still going forward under our eyes,
we discover a four-fold process of production
in connection with rocks : 1st. Eruptive rocks,
rocks thrown out from the interior of the earth,
in a liquefied, or softened and more or less te-
nacious state (volcanic and Plutonic rocks).
2d. Sedimentary rocks, rocks deposited from
fluids in which the particles had been either
dissolved or suspended, but from which they
were precipitated and deposited upon the sur-
face of the crust of the earth. The greater
number of the floetz and tertiary groups. 3d.
Metamorphic rocks, rocks altered in their inti-
mate structure and stratification, either through
the contact and vicinity of a Plutonic or vol-
canic (endogenous) C^^) ejected rock, or — and
this is more commonly the case — altered by the
penetration of the vaporiform subhmed mat-
ters(2i2), which accompany the escape of certain
molten ejected masses. 4th. Conglomerates
— coarse or fine-grained sandstones, breccias —
rocks made up of mechanically divided masses
of the three former species.

These four-fold rock-formations, which still
go on at the present day, through the effusion
of volcanic masses in the shape of streams of
lava, through the influence of these masses
upon rocks consolidated at a former period,
through mechanical separation or chemical pre-
cipitation from liquids charged with carbonic
acid, finally, through the cementation of frag-
ments often of totally different kinds of rocks,
are phenomena and formative processes which
can, however, only be regarded as weak reflec-
tions of what went on under the higher inten-
sity of action in the life of the earth during the
chaotic state of the primitive world, and under
totally diflferent conditions of pressure and high
temperature, not only of the wliQle crust of the

•^

FUNDAMENTAL FORMS OF ROCKS.

78

earth, but of the atmosphere, surcharged with
moisture and of much greater extent than it is
at the present day. If at the present time, on
surfaces as extensive as Europe, we scarcely
find four openings (volcanoes) through which
eruptions of fire and molten matters can take
place, the firm crust of the earth was traversed
in former periods by vast open fissures, through
which mountain chains were upheaved, or into
which streams of molten rock — granite, por*
phyry, basalt, and melaphyre — were injected,
and by which they were variously stopped and
filled up. At former epochs, in the much and
variously fissured, thinner, and upwardly and
downwardly fluctuating crust of the earth, there
were almost everywhere passages of commu-
nication between the molten interior and the
atmosphere. Gaseous emanations arising from
very dissimilar depths, and therefore bringing
chemically different substances, then animated
the Plutonic formative and transformative pro-
cesses. The sedimentary formations, too, the
precipitations from liquids, which we designate
travertin, and which we see proceeding in the
neighbourhood of Rome as well as of Hobart
Town in Australia, from cold and hot springs
and river waters, give but a very poor idea of
the origination of the floetz formations. Our
seas, in virtue of processes which have not yet
been examined generally enough, or with suffi-
cient care, gradually form by precipitation, by
overflowing and by cementation, small calca-
reous banks, which, at some points, almost ap-
proach Carrara marble in hardness("3). This
process goes on upon the Sicilian coasts, the
Island of Ascension, and King George's Sound
in Australia. On the coasts of some of the
"West India islands these formations of the
present ocean now enclose earthenware ves-
sels and other products of human manufactu-
ring industry ; and in the Island of Guadaloupe,
even skeletons of the Carib race of men. The
negroes of the French colonies characterize
this formation as the " Masonry of God" (Ma-
(jonne-bon-Dieu) ("*). In the Island of Lan-
cerote, one of the Canaries, there is a small
oolitic stratum, admitted to be a product of the
sea and of storms, but which, despite its new-
ness, reminds us of the Jurassic limestone(2^^).

The compound rocks are determinate asso-
ciations of certain simple minerals — felspar,
mica, solid silicic acid, augite, and nephehne.
Very similar rocks, i. e. rocks made up of the
same elements but otherwise grouped, are pro-
duced by volcanic processes under our eyes, at
the present time, just as they were in former
epochs of the world's history. The independ-
ence of rocks in respect of geographical posi-
tion or relationship, is so great, that, as we
have already observed("^), the geologist sees
with amazement, to the north and south of the
equator, in the farthest zones of the earth, the
same familiar appearances in the rocks, the
repetition of the minutest details in the pe-
riodic series of the Silurian strata, and in the
eflfects of contact with augitic masses, the prod-
ucts of eruptions.

If we now take a closer view of the four fun-
damental forms of rock (the four phases in the
formative process) in which the stratified and un-
stratified portions of the crust of the earth pre-
sent themselves to us, we may designate among

the endogenous or eruptive rocks, (the massive
and abnormal rocks of some modern geologists),
the following principal groups, as immediate
evidences of subterraneous activity, viz. :

Granite and Syenite — of very different rel-
ative ages, but frequently penetrating both gran-
ite and syenite of more recent formation in
veins(2i7). Along with these it is also proper
to consider the forcing or upheaving power.
"Where granite protrudes in evenly vaulted
ellipsoids, in great masses, like islands, wheth-
er this be in the Harzforest, or in Mysore, or
in Lower Peru, it is always covered with layers
that have become fissured into blocks. Suoh
a rocky sea probably owes its origin to a con-
traction of the upper surface of the granitic
vault, which, on its protrusion, and originally,
must have been very much expanded"("^'»).
In Northern Asia also(=*^^), in the charming,
the romantic neighbourhood of Lake Kolyvan,
on the north-western declivity of the Altai
range, as also on the slopes of the maritime
chain of Caraccas, near Las Trincheras(2='°), I
observed the granite subdivided into blocks or
pilesj in consequence, possibly, of such con-
tractions, but which in these cases appear to
have extended deeply into the interior. Far-
ther to the south of Lake Kolyvan, towards the
confines of the Chinese province Hi, between
Buchtarminsk and the river Narym, the char-
acters of the entire mass of ejected rock, which
is here unaccompanied by gneiss, are more stri-
king than I have observed them in any other
part of the globe. The granite, always scaling
and crumbling on the surface, and splitting up
into tabular masses, rises in the steppes here
in low semi-globular hillocks, not more than six
or eight feet high, there in basalt-like knolls,
which run out at opposite sides, as it were,
into thin wall-like effusions(=*='i). By the cat-
aracts of the Orinoco, as well as in the Fichtel-
gebirge (Seissen), in Gallicia, and betwixt the
Southern Ocean and the lofty platforms of Mex-
ico (at Papagallo), I have seen granite in great
depressed globular masses, which, like basalt,
split or scaled off in concentric layers. In the
valley of the Irtisch, between Buchtarminsk
and Ustkamenogorsk, the granite covers the
clay-slate for a mile in length("2)^ and pene-
trates the same strata from above in slender
veins, which are numerously branched, and
wedge-shaped at their extremities. I have ad-
duced these particulars by way of examples,
only that I may illustrate the individual char-
acters of an eruptive rock in one of the most
widely diffused of the mineral masses. In the
same way as the granite overlies the schists in
Siberia, and in the Department of Finisterre
(Isle de Michau), so does it cover the Jurassic
limestone in the mountains of Oisons (Fer-
ments), and syenite, and chalk with syenite in-
terposed, near Weinbohla, in Saxony(='"). In
the Ural mountains near Mursinsk, the granite
shows drusy cavities, and the druses here, like
the fissures and druses of newer volcanic pro-
ductions, are the Plutonic seat of numerous
beautiful cystals, particularly of beryl and topaz.

QuARTzosE Porphyry, from its relations of
stratification, having frequently the character
of veins. The base is generally a finely gran-
ular mixture of the same elements which pre-

76

FUNDAMENTAL FORMS OF ROCKS.

sent themselves to us as large embedded crys-
tals. In granitic porphyry, which is very poor
in quartz, the felspathic base is at once granu-
lar and foliaceous^*^'*).

Greenstone or Diorite — granular mixtures
of white albite and blackish-green hornblende,
constituting dioritic porphyry, when a base of
denser texture is present in which the crystals
lie embedded distinctly. These greenstones,
which, pure in one place, pass in another into
serpentine, from the laminae of diallage which
they include (Fichtelgebirge), are occasionally
found lying in beds upon the old stratification
clefts of the green clay slate, and penetrating
them; but they more frequently make their
way through the rock in the manner of veins,
or they present themselves as greenstone balls,
analogous in all respects to balls of basalt and
porphyryC^^**).

HypERSTHENE RocK — a granular mixture of
Labrador felspar and hypersthene.

EuPHOTiDE and Serpentine, occasionally con-
taining crystals of augite and uralite, instead of
diallage, and thus nearly allied to a more com-
mon rock, and, I might add, one that indicates
a still higher degree of eruptive activity,' viz.,
augitic porphyry(=^26^

Melaphyre, Augitic, Uralitic, and Oligo-
GLAssic Porphyry. To the last belongs the true
verd antique, so celebrated as a material em-
ployed in the arts.

Basalt, with olivine and constituents becom-
ing gelatinous with acids, phonolite (porphy-
ritic slate), trachyte and dolerite. The sec-
ond of these rocks always divides into thin ta-
bles ; the first only shows this structure par-
tially, which, however, gives them both an ap-
pearance of stratification over extensive dis-
tricts. According to Girard,mesotype and neph-
eline form important elements in the composi-
tion and intimate texture of basalt. The neph-
eline of basalt reminds the geologist of the mi-
ascite of the Ilmengebirge in the Ural chainC^'^^),
which frequently replaces granite, and occasion-
ally contains zircon, as well as of the pyroxenic
nepheline discovered by Gumprecht near Lobau
and Chemnitz.

To the second class of fundamental forms,
the sedimentary rocks, belongs the greater
portion of the formations which used to be ar-
ranged under the old systematic, but by no
means correct, designation of Transition and
Floetz, or secondary and tertiary formations.
Had the igneous rocks exerted nothing of an
uplifting, and, with simultaneous quaking of the
earth, of a concussive influence upon these
sedimentary formations, the surface of our
planet would have consisted of a series of uni-
form strata horizontally disposed one upon an-
other. Without mountains, on whose acclivi-
ties the progressive diminution in the tempera-
ture of the air is picturesquely reflected, not
only in the luxuriance of vegetation, but in the
kinds of plants that are produced, the monot-
onous surface would only have been broken
here and there by ravines eroded by water-
courses or by small collections of drift, the ef-
fect of masses of fresh water thrown into gen-
tle undulations ; the several continents from
pole to pole, and under every variety of cli-
mate, would have presented the dreary uni-

formity of the South American Llanos or of the
Northern Asiatic steppes. As in the greater
portion of these, we should then have seen the
vault of heaven resting on the plain, and the
stars rising and setting as if they emerged
from the bosom of the ocean, and dipped into it
again. But such a state of things even in the
primitive world could never have been of any
considerable duration as regards time, nor of
any thing like general prevalence in respect of
space ; the subterraneous powers, at every
epoch in the history of nature, have been at
work striving to subvert and to change it.

Sedimentary strata are precipitated or de-
posited from liquids, according as the matter
before the formation was either held chemical-
ly dissolved, as in the case of lime, or merely
I suspended and mixed, as in the case of clay-
I slate, mica-slate, &c. But even when earthy
I matters are thrown down from fluids impreg-
i nated with carbonic acid, the descent of the
matter during its precipitation and accumula-
tion into strata, must be regarded as a me-
chanical element in the process of formation.
This view is of some importance in connection
with the envelopment of organic bodies in pet-
rifying calcareous tufl^s. The oldest sediments
of the transition and secondary formations
have apparently taken place from waters more
or less elevated in temperature, and at a pe-
riod when the heat of the upper crust of the
earth was still very considerable. In this way,
therefore, a Plutonic influence was also at work
to a certain extent in connection with the sedi-
mentary strata, particularly the oldest of them ;
these strata, however, appear to have become
hardened from the state of mud into the schis-
tose structure, under great pressure ; not like
the rocks that have risen up from the interior
(granite, porphyry, basalt), to have been con-
solidated by cooling. As the primitive waters
of the globe cooled by degrees, they became
capable of holding a larger and larger quantity
of carbonic acid gas in solution, which they
may have attracted from the atmosphere, sur-
charged with this gas in the earlier epochs of
creation, and so of holding dissolved a larger,
quantity of calcareous earth.

The Sedimentary strata, from which we
here separate all the other exogenous purely
mechanical precipitates of sand or fragmentary
rocks, are these ;

Schists or Slates of the inferior and supe-
rior transition rocks, consisting of the Silurian
and Devonian formations ; from the lower Si-
lurian, or as they were once designated, Cam-
brian, strata, to the uppermost bed of the Old
red sandstone or Devonian formation, where it
comes in contact with the Mountain limestone ;

Carboniferous deposits — Coal formation ;
. Limestones, interstratified in the transition
and coal formations ; Zechstein, Muschelkalk,
Jura formation and Chalk, also the portion of
the tertiary formation which does not present
itself to us as sandstone and conglomerate ;

Travertine, fresh-water limestone, the si-
licious sinter of hot springs — formations. that
have originated not under the pressure of great
pelagic coverings of water, but almost in con-
tact with the air in shallow pools and rivulets ;

Infusorial strata, a geological phenome-

METAMORPHOSES OF ROCKS.

77

non, the vast significance of which, as proclaim-
ing the influence of organic activity upon the
formation of the solid constituents of the earth,
was discovered in very recent times, by my in-
lellectually-gifted friend and fellow-traveller,
Ehrenberg.

If in this short but comprehensive survey of
the mineral constituents of the crust of the
earth, we do not immediately refer to numbers
of simple sedimentary rocks, the various con-
glomerate and sandstone formations, partly de-
posited from liquids, that are so variously in-
termingled with the schists and the limestones
both of the floetz and transition series, this is
only because these, besides fragments of erup-
ted and sedimentary rocks, also contain pieces
of gneiss, mica-schist, and other metamorphic
masses. The obscure process of transforma-
tion (metamorphosis), and the influence it ex-
erts, must, from this showing, constitute the
third class of fundamental forms.

The endogenous or eruptive rocks (granite,
porphyry, and melaphyre), exert an influence,
as already oftener than once observed, not
merely of a dynamical kind, shattering or up-
heaving, erecting or pushing strata aside ; by
their presence they farther produce changes in
the chemical composition of their constituents,
as well as in the nature of their intimate tex-
ture. NeAr species of rocks are produced,
gneiss and mica slate, and granular or sac-
charoidal limestone (Carrara and Parian mar-
ble). The old Silurian or Devonian transition
schists, the belemnitic limestone of Tarantaise,
the grey unlustrous macigno or cretaceous
sandstone of the Northern Apennines, with its
included sea-weed, are difficult of recognition
after their transformation into new and fre-
quently-sparkling textures. The belief in the
metamorphosis, indeed, has only been confirm-
ed since we have succeeded in following the
several phases of the transformation, step by
step, and have come to the assistance of in-
ductive conclusions with the results of direct
chemical experiments, the employment of dif-
ferent fusing heats, degrees of pressure, and
rates of cooling. When the study of chemical
combinations is extended under the guidance
of leading ideas("8), we find that from the nar-
row confines of our laboratories, we can dif-
fuse a clear light over the wide field of geolo-
gy, over the great subterraneous rock-compo-
sing and rock-transforming workshop of Na-
ture. The philosophical inquirer escapes being
deceived by seeming analogies, by limited views
of the natural processes, when he keeps steadi-
ly in his eye the complication of circumstan-
ces which, in the intensity, the immeasurable-
ness of their force, were competent, in the
primitive world, to modify the reciprocal influ-
ences of individual substances familiarly known
to us at the present day. The simple or unde-
composed bodies have unquestionably obeyed
the same forces of affinity at all times ; and
where contradictions seem to meet us now, it
is my most intimate persuasion, that chemistry
will herself, for the most part, come upon the
traces of conditions not fulfilled in like or due
measure, as causes of these contradictions.

Accurate observations, embracing extensive
districts of mountainous country, satisfy us that

the eruptive rocks do not intei vene as any dig-
orderly or lawless power. In the most distant
countries of the world, we frequently see gran-
ite, basalt, or diorile, exerting their transform-
ative force, in every the most minute particu-
lar, alike upon strata of clay-slate, on thick
beds of limestone, and on the grains of quartz
of which sandstone consists. As the same
kind of endogenous rock almost everywhere
exerts the same kind of influence, different
kinds of rocks belonging to the same class ol
endogenous or eruptive formations, exhibit, on
the contrary, very different characters. In-
tense heat, above all, has exerted an influence
in the whole of the phenomena ; but the degree
of molten fluidity attained — perfect mobility of
particles, or a more viscid or glutinous adhesion
among them — has been very different in gran-
ite and basalt ; in different geological epochs,
indeed (phases in the transformation of the crust
of the earth), along with the eruptions of gran-
ite, basalt, porphyritic greenstone or serpentine,
various other substances dissolved in vapours
have arisen from the interior laid open. And
this is the place to remind the reader anew,
that in the rational views of modern geology,
the metamorphosis of rocks is not limited to the
mere phenomena of contact, to the apposition
of two different kinds of rock ; but that geneti-
cally it comprises all that has accompanied the
protrusion of a particular ejected mass. In
situations where no immediate contact has
taken place, the mere vicinity of such a mass
causes modifications in the induration, the sil-
icification, the granulation, the crystallization
of adjacent rocks.

All eruptive rocks penetrate the sedimentary
strata, and other likewise endogenous masses,
as veins ; but the distinction that is apparent
between the Plutonic rocks(2^') — granite, por-
phyry, serpentine — and those which, in a more
restricted sense, are called volcanic (trachyte,
basalt, lava), is of especial importance. The
rocks which our present volcanoes, as rem-
nants of the activity of the body of the earth,
produce, appear in narrow streams, which,
however, may still form sufficiently wide beds
when several of them meet in hollows or ba-
sins. Basaltic eruptions, where they have been
traced deeply, have been repeatedly seen to
terminate in slender taps. Flowing from nar-
row openings, as in the Pftasterkaute, near
Marksuhl, two miles from Eisenach, in the blue
knolls, near Eschwega (banks of the Werra),
and at the Druid's-stone, on the Hollert ridge
(Siegen), to cite three examples indigenous to
Germany, the basalt breaks through the red
sand-stone and greywacke schist, and spreads
out above, like the cap of a mushroom, into
knolls, which in one place appear split into
columnar groups, in another are thinly strati-
fied. Not so granite, syenite, quartzose, por-
phyry, serpentine, and the entire series of un-
stratified massy rocks, which, from an attach-
ment to mythological nomenclature, have been
called Plutonic. These, with the exception of
a few veins, have been ejected, not in a molten
liquefied state, but in one merely tenacious and
softened, and not from narrow crevices, but
from wide valley-like chasms, and extensive
gorges. They have been forced, they have not
flowed out : they present themselves not in

78

METAMORPHOSES OF ROCKS.

streams, like lava, but spread out in immense
massesC"). Among the dolerites and tra-
chytes, some groups give indications of a cer-
tain basalt-like fluidity ; others, expanded into
vast bell -shaped elevations and craterless
domes, appear to have been merely softened
when they were protruded. Other trachytes,
again, those of the Andes among the number,
which I frequently found very closely allied to
the greenstones and syenitic-porphyries, so rich
in silver, and then without quartz, lie in beds
like granite and quartzose- porphyry.

Experiments upon the alterations which the
structure and chemical constitution of rocks
undergo through fire("^), have showed that the
volcanic masses, diorite, augitic porphyry, ba-
salt, and lava from JEtna, according to the de-
gree of pressure under which they were melted,
and the rate of their cooling, were either, when
quickly cooled, brought to the state of a black
glass of an even fracture, or when slowly cool-
ed made to assume the appearance of a stony
mass having a granular crystalline texture.
The crystals in such cases were either pro-
duced on the sides and cavities, or embedded
in the general basic mass. The same material
— and this consideration is of great importance
as regards the nature of the eruptive rock, or
the transformations it has undergone — yields
the most dissimilar-looking products. Carbo-
nate of lime, melted under high pressure, does
not lose its charge of carbonic acid ; the cooled
mass is granular limestone, saccharoidal mar-
ble. So much for crystallization in the dry
way ; in the moist way, calcareous spar as well
as Aragonite is produced, the former under a
moderate, the latter under a higher, degree of
heatC^"). According to diversities of temper-
ature, the consolidating particles of crystals in
process of formation arrange themselves va-
riously and in particular determinate direc-
tions ; the very form of the crystals, indeed,
varies with the temperature under the influ-
ence of which they are producedC^"). There
is, moreover, under certain relations, and with-
out the intervention of any fluid state, a trans-
position(2^*) of the minute particles of a body,
which is proclaimed by optical effects. The
phenomena presented by devitrifaction, by the
production of cemented and cast steel, by the
transition of the fibrous structure of iron into
one that is granular, under the influence of el-
evated temperature(22^), perhaps even of very
insignificant but equable and long-continued
concussions, all conduce to throw light upon
the processes of geological metamorphosis.
Heat can even induce opposite effects at the
same time upon crystalline bodies ; for Mits-
cherlich's beautiful experiments show that cal-
careous spar, without altering its state of ag-
gregation, expands in the direction of one of
its axis of crystallization, and contracts in an-
other("«).

If from these general considerations we pass
on to particular examples, we first observe
schists turned into black-blue roofing slate by
the vicinity of Plutonic ejected rocks. The
clefts of stratification are then interrupted by
another system of clefts which cut the former
almost perpendicularly, and indicate the opera-
tion of a later influence("'). By the penetra-
tion of silicic acid, clay slate, traversed by frag-

ments of quartz, is partially changed into whet-
stone slate (Wetzschiefer, whitestone or Eu-
ritel) and sihcious slate (Kieselschiefer, quart-
zitel), the latter frequently carboniferous, and
then galvanic in its effects on tlie nerves. The
highest degree of silicification of the schists("«),
however, is found in a precious material em-
ployed in the arts, ribboned jasper, produced
in the Ural Mountains by the contact of erup-
tive augitic porphyry (Orsk), dioritic porphyry
(Auschkul), or hypersthene rock (Bogoslowsk) ;
in the Island of Elba (Monte Serrato), accord-
ing to Fr. Hoffmann, and in Tuscany, accord-
ing to Alexander Brongniart, by contact with
euphotide and serpentine.

The contact and Plutonic influence of granite
cause clay-slate to become granular, changing
it into a granitic-looking mass — into a mixture
of felspar and mica, in which again larger plates
of mica lie embedded("^> — a fact which Gus-
tavus Rose and I observed within the fortress
of BuchtarminskC^*"). "That the whole of
the gneiss lying between the Icy Sea and the
Gulph of Finland has been formed and trans-
formed by the agency of granite out of Silurian
strata of the transition series, may now, as
Leopold von Buch has said, be assumed as an
hypothesis familiar to all geologists, and ac-
cepted by the greater number as demonstrated.
In the Alps of St. Gothard cretaceous marl is
met with transformed by granite, ffrst into mi-
caceous schist, and then into gneiss'X'^").
Similar phenomena in respect of gneiss and
mica slate formations, under the influence of
granite, are presented : in the Oolitic group of
Tarantaise(=^*2), where belemnites have been
found in rocks that already lay claim to the de-
nomination of mica schist ; in the schistose
group of the western portion of the Island of
Elba, not far from Cape Calamata, and in the
Fichtelgebirge of Bayreuth, between Lomitz
and Markleiten(^").

Precisely as jaspar, a substance employed in
the arts, which was inaccessible to the ancients
in large masses(2**), is the product of volcanic
agency upon augitic porphyry, so is the other
artistic material, so variously and so success-
fully employed by them, granular marble, to be
regarded as a sedimentary stratum altered by
the heat of the earth and the vicinity of an
eruptive rock. Careful observation of phe-
nomena of contact, and the remarkable experi-
ments of Sir James Hall on the fusion of rocks,
now more than half a century old, in addition
to the diligent study of granitic veins, which
contributed so essentially to the early founda-
tions of our present geology, warrant such a
conclusion. The protruded rock has occasion-
ally changed the dense calcareous deposit into
granular limestone to a certain thickness only,
or in a certain zone from the line of contact.
We find a partial transformation, like a half-
shadow, at Belfast in Ireland, where basaltic
dykes penetrate the chalk ; in the same way,
in the compact floetz-limestone near the bridge
of Boscampo, and by the waterfall of Canzocoli
in the Tyrol,, celebrated by Count Marzari Pen-
cati, the strata have been partially bent where
they come in contact with a syenitic granite(=^**).
Another kind of transformation is that in which
the whole of the beds of compact calcareous
rock are changed into granular limestone

METAMORPHOSES OF ROCKS.

79

through the influence of granite, syenite, or
dioritic porphyry^*®).

Let me be allowed to refer particularly in
this place to the Parian and Carrara marbles,
which have become so necessary to the noblest
efforts of the sculptor, and which have served
but too long in our geological collections as
principal types of primitive limestone. The ef-
fects of the granite here reveal themselves
partly under immediate contact, as in the Pyr-
enees("^), partly, as in the continent of Greece
and the islands of the ^gean Sea, through in-
terposed strata of gneiss and mica slate. In
both cases the process of transformation of the
calcareous rock is contemporaneous, but dis-
similar. It has been observed at Cubsea, in
Attica, and in the Peloponnesus, " that the rule
is, that the limestone which rests upon mica
slate is by so much the more beautiful and
crystalline as the schist is purer, that is, as it
is freer from argillaceous admixture." Mica
slate, as well as gneiss strata, present them-
selves at many deep points of Pares and Anti-
paros(^*^). If marine productions were discov-
ered [in ancient times] in the quarries of Syra-
cuse, and the " impression of a small fish" was
seen in the deepest of the rocks of Paros, as
we may infer from a notice in Origen, of the
old Eleatic philosopher, Xenophanes of Colo-
phon (2*^), who conceived the whole of the
world to have been formerly covered by the
sea, we might believe in the remains of a floetz
stratum in this situation which had not under-
gone complete metamorphosis. The marble
of Carrara (Luna), which was employed before
the Augustan age, and was the principal source
of the material for statues so long as the quar-
ries of Paros remained closed, is a stratum of
the same cretaceous sandstone (macigno) al-
tered by Plutonic agency, which presents itself
in the insulated Alpine height, Apuana, lying
between gneiss -like micaceous and talcose
schistsC^"). Whether or not granular lime-
stone, formed in the interior of the earth, and
filling fissures in the manner of veins (Auer-
bach on the Bergstrasse), have ever been forced
to the surface by gneiss and syenite(='^^), I can-
not, through want of personal observation, take
it upon me to decide.

The most remarkable metamorphoses of
compact calcareous strata, however, according
to Leopold von Buch's able observations, are
to be seen in the Southern Tyrol, and among
the Italian slopes of the Alps, effected princi-
pally by the intrusion of dolomitic masses.
The metamorphosis of the calcareous rock
here proceeds from fissures, which traverse it
in all directions. The clefts are everywhere
covered with rhomboids of magnesian spar ; the
whole formation indeed, without stratification,
and without a vestige of the fossils which it
formerly included, then consists exclusively of
a granular aggregation of dolomitic rhomboids.
Talc leaves and transverse fragments of ser-
pentine lie here and there dispersed through
the new-fashioned rock. In Fassathal, the dolo-
mite rises perpendicularly in the form of smooth
walls of dazzhng whiteness to the height of
several thousand feet. It forms pointed coni-
cal hills, which stand side by side in great num-
bers without touching one another. Their
physiognomical character brings to mind that

i sweetly fantastical mountain landscape with
I which Leonardo da Vinci has ornamented the
! back-ground of his portrait of Mona Lisa.
I The geological features which we are here
portraying excite the imagination as well as
reflection ; they are the work of an augitic por-
phyry, which has intruded and produced its ef-
fect, by upheaving, shattering, and transform-
^^Si )• The dolomitizing process is by no
means regarded by the gifted inquirer who first
pointed it out as an imparting of magnesian
earth by the black porphyry, but as a change
effected contemporaneously with the protrusion
of the injected rock into extensive fissures fill-
ed with vapour. It remains for future inquiries
to determine in what way the transformation
is effected when the dolomite occurs in beds
between limestone strata, without contact with
the endogenous rock, where the conduits of
Plutonic influences lie concealed. But it is not
perhaps necessary, even here, to take refuge in
the old Roman saying, according to which
*' much that is like in nature has been produced
in totally different ways." If in an extensive
district of country, two phenomena, viz., the
protrusion of melaphyrC; and the alteration in
crystalline texture and chemical constitution
of a compact calcareous rock, always go to-
gether, then may we, with some reason, con-
jecture, that in cases where the second phe-
nomenon presents itself without the first, the
seeming contradiction in the non-fulfilment is
connected with certain conditions accompany-
ing the occult principal cause. Should we
question the volcanic nature of basalt and its
state of liquefaction through fire, because a
few rare instances have been met with in
which dykes of this substance traverse carbo-
niferous sandstone and cretaceous strata, with-
out the coal being deprived of its bitumen, the
sandstone reduced to the state of frit, or the
chalk being turned into granular marble *?
Where we meet with even a twilight glimmer,
with the faintest trace of a way in the obscure
region of mineral formations, we must not
thanklessly reject both, because there is still
much unexplained in the relations of transition
from one rock to another, and in the isolated
interposition of altered between unaltered
strata.

Besides the transformation of compact cal-
careous carbonate into granular limestone and
into dolomite, there is a third metamorphosis
of the same deposit, which must here be ad-
verted to, and which is attributable to the vol-
canic eruption of sulphuric-acid-vapours, in
primeval epochs. This transformation of lime-
stone into gypsum is connected with the pene-
tration of rock-salt and sulphur (the latter pre-
cipitated from watery vapour charged with the
mineral). In the lofty chain of the Andes of
Quindiu, far from all volcanoes, I have myself
observed this precipitate within fissures in
gneiss, whilst the sulphur, gypsum, and rock-
salt of Sicily (Cattolica, near Girgenti) belong
to the newest secondary strata, or to the chalk
formations("3). i have farther seen fissures
filled with rock-salt, in quantities that some-
times tempt the people to engage in an illicit
traflic in the article, in the edge of the crater of
Vesuvius. On both slopes of the Pyrenees it
is impossible to doubt the connection of diorit-

80

ARTIFICIAL PRODUCTION OF SIMPLE MINERALS.

ic (and pyroxenic 1) rock, with the appearance
of dolomite, of gypsum, and of rock-salt("*).
Everything in the phenomena here referred to
proclaims the influence of subterraneous forces
upon the sedimentary strata of the ancient
ocean.

The beds of pure quartz of enormous magni-
tude, which are so characteristic of the Andes
of South America(2") — ^^d I may here state
that I have seen such beds between 7 and 8,000
feet in thickness, in the route from Caxamarca
to Guangamarca, descending towards the south-
ern ocean — are of enigmatical origin. They
rest in one place upon quartzless porphyry, in
another upon dioritic rocks. Have they been
produced from sandstone, as M. Elie de Beau-
mont conjectures has been the case in regard
to the quartz strata of the Col de la Poisson-
niere, to the east of Briancjon 1("®) In the di-
amond districts of Minas Geraes and St. Paul,
in Brazil, which have been lately so carefully
examined by Clausen, Plutonic forces acting
upon dioritic veins have developed in one place
common mica, in another ferruginous mica, in
the quartzose itacolumite. The diamonds of
Grammagoa are contained in layers of solid si-
licic acid ; occasionally they lie enveloped by
plates of mica, exactly like the garnets formed
in mica-slate. The most northern of all the
diamonds which have been found since the year
1829, under the 58th parallel of north latitude,
on the European declivity of the Ural mount-
ains, also stand in geological relation to the
black carboniferous dolomite of Adolfskoi(2^^),
as well as to augitic porphyry, which have not
yet been made the subject of sufficiently accu-
rate observations.

Among the most remarkable contact-phe-
nomena, finally, are comprised the formation
of garnets in clay-slate, under the influence of
basalt and dolerite, instances of which occur in
the county of Northumberland and in the island
of Anglesea ; and for the production of a great
number of beautiful and very dissimilar crys-
tals—garnets, Vesuviane, augite, and Ceylanite
— which make their appearance upon the con-
tingent surfaces of eruptive and sedimentary
rocks, on the boundary of the syenite of Mon-
zon with dolomite and compact limestone("^).
In the island of Elba, the masses of serpen-
tine, which nowhere, perhaps, present them-
selves so conspicuously as eruptive rocks, have
caused the sublimation of iron glance and red
iron stone into the fissures of a cretaceous
sandstone("9). The same iron glance is still
seen every day, sublimed from vapour, upon
the edges of open fissures in the craters of
Stromboli, Vesuvius, and ^Etna, and in cracks
of the recent lava streams of these volca-
noesC^fiO). As we here perceive the materials
of veins produced under the influence of volcan-
ic forces before our eyes, and where the neigh-
bouring rock has already attained to a state of
solidity, we conceive how mineral and metallic
veins may have been produced during the ear-
lier revolutions of the crust of the earth ; when
the solid, but still thin shell of the planet, re-
peatedly shaken by earthquakes, shattered and
rifted by alterations in its volume occasioned by
cooling, presented numerous communications
with the interior, numerous outlets for vapours
laden with earthy and metallic substances.

1 The stratified arrangement of the mineral
I matters parallel with the surfaces bounding
veins, the regular repetition of similar layers
on both sides, on the roofs and on the floors of
veins, and the druses or elongated cavities of
their middles, indeed, frequently bear imme-
diate testimony to a Plutonic process of subli-
mation in metalliferous veins. As the matter
traversing is of more recent origin than the
matter traversed, we learn from the relations
of position of the porphyry to the silver-ore
formations of the Saxon Erzgebirge, that these,
in the mountains which are richer in mineral
treasures than any others in Germany, are at
least younger than the trunks of trees of the
coal formation and than the lower new red
sandstone (Rothliegendes) ("*).

All our geological speculations, in regard to
the formation of the crust of the earth and the
metamorphosis of rocks, have had unexpected
light thrown on them, by the happy idea of as-
similating the production of scoriae in our smelt-
ing furnaces, to the formation of natural min-
erals, and of reproducing these artificially from
their elements(2"). The same affinities, de-
termining chemical combinations, come into
play in all these operations, whether they be
conducted in our laboratories or in the bosom
of the earth. The most important simple min-
erals, characterizing the very generally distrib-
uted Plutonic and volcanic rocks, as well as
those that have suffered metamorphosis through
them, have been found in our artificial mineral
formations in the crystalline state, and like the
natural ones in all respects. We distinguish
those that have arisen accidentally in scoriae,
from those that have been produced intention-
ally by chemists. To the former belong fel-
spar, mica, augite, olivine, blende, crystalline
oxide of iron (iron glance), octohedral magnet-
ic iron, and metallic titanium(='^^) ; to the lat-
ter garnet, idokras, ruby (equal in hardness to
the Oriental stone), olivine, and augite(=«*).
The minerals now named form the principal
constituents of granite, gneiss, and mica schist,
of basalt, dolerite, and numerous porphyries.
The artificial production of felspar and mica, in
particular, is of signal geological importance
for the theory of the formation of gneiss by the
transformation of clay slate. This contains the
elements of granite, potash not excepted('").
It would not, therefore, be any thing very ex-
traordinary, as an acute geologist, M. von
Dechen, has observed, were we one day to find
a piece of gneiss produced upon the walls of a
smelting-furnace built of clay-slate and grey-
wacke.

In these general considerations on the solid
crust of the earth, and after having indicated
three original forms of production in reference
to its mineral masses, viz., Eruptive, Sediment-
ary, and Metamorphosed rocks, there still re-
mains a fourth class, the Conglomerated, or
fragmentary, to wit. This title of itself brings
to mind the denudations or destructions which
the surface of the earth has suffisred ; but it
also farther reminds us of the process of ce-
mentation or agglutination that has been ef-
fected by oxide of iron, and by argillaceous and
calcareous [and silicious] cements, by which in
one case rounded, in another angular, frag-
ments have been again united. Conglomerates

PALiGOZOOLOGY.

81

Rnd breccias, in the widest sense of these words,
reveal the character of a two-fold mode of ori-
gin. The materials of which they are mechan-
ically composed have not always been accumu-
lated by the waves of the sea, or by streams
of fresh water in motion ; there are fragment-
ary rocks in the production of which the shock
or the action of water has had no part. " When
basaltic islands, or trachytic mountains, arise
upon fissures, the friction of the rock as it as-
cends against the sides of the fissure causes ba-
salt and trachyte to become surrounded by ag-
glomerates of their own masses. The grains
of which the sandstones of many formations
consist have been more detached by the attri-
tion of outbreaking volcanic, or Plutonic rocks,
than produced by the motion of a neighbouring
ocean. The existence of such attrition-con-
glomerates, which are encountered in enormous
masses in both divisions of the globe, bear wit-
ness to the intensity of the force with which
the eruptive masses have been forced to the
surface from the interior. The waters then
obtained power over the smaller detached gran-
ules, and spread them out in layers which they
themselves covered'X'^*^). Sandstone forma-
tions are found intercalated among all the
strata, from the lower Silurian transition se-
ries, to this side the chalk in the tertiary for-
mation. On the edges of the vast plains of the
New World, both within and without the trop-
ics, they are seen as walls or bulwarks, indica-
ting, as it seems, the coasts against which the
mighty waves of a former ocean once dashed
themselves into foam.

If we venture a glance at the geographical
distribution of rocks, and their relations in
point of place in that portion of the crust of the
earth which is accessible to our observation,
we perceive that the most generally distributed
chemical material of all is silicic acid, either in
the transparent and colourless state, or opaque
and variously tinged. After solid silicic acid
comes carbonate of lime ; then follow in order
the compounds of silicic acid with alumina,
with potash and soda, with lime, magnesia, and
oxide of iron. If the masses which we call
rocks be definite associations of a small number
of minerals, to which a few others, but also of
determinate kinds only, are added as parasites ;
if, in the eruptive rock granite, the association
of quartz (silicic acid), felspar and mica be the
essentials, so do these minerals, either isolated
or in pairs, present themselves in many other
strata. With a view of illustrating by an ex-
ample how quantitative relations distinguish a
felspathic rock from another abounding in mica,
I here remind the reader, as Mitscherlich has
done, that if three times more alumina, and
one third more silicic acid than belong to it
naturally be added to felspar, we have the com-
position of mica. Potash is contained in both,
a substance the existence of which in many
mineral masses reaches far beyond the com-
mencement of everything like vegetation on
the surface of the earth.

The succession, and with this the age of the
several formations, are ascertained or deter-
mined by the reciprocal position of the Sedi-
mentary, Metamorphic, and Conglomerate stra-
ta, by the nature of the formations up to which

the Eruptive masses ascend, but most certain-
ly and safely by the presence of organic re-
mains and the diversities of their structure.
The application of Botanical and Zoological
knowledge to the determination of the age of
rocks, the chronomcfry of the crust of the earth,
which Hook's great spirit had already di-
vined(»«^), marks one of the most brilliant ep-
ochs in the progress of geology, now finally ab-
stracted, on the Continent at least, from Se-
mitic influences. Palaeontological studies have,
as with a vivifying breath, given grace and the
charms of variety to the doctrine of the solid
materials of the globe.

The fossiliferous strata present us with the
entombed floras and faunas of bygone millen-
niums. We ascend in time, whilst, penetra-
ting downwards from layer to layer, we deter-
mine the relations in space of the several for-
mations. An animal and vegetable existence
that has passed away is brought to light.
Wide-spread revolutions of the globe, the up-
heaval of mighty mountain chains, whose rela-
tive ages we are in a condition to determine,
denote the destruction of old organic forms,
the appearance of new. A few of the older
still show themselves for a time among the
newer forms. In the narrowness of our knowl-
edge of original production, in the figurative
language with which this circumscription of
view is concealed, we designate as new crea-
tions the historical phenomena of change in the
organisms, as in the tenancy of the primeval
waters, and of the uphfted dry land. These
extinct organic forms are in one case pre-
served entire, even to the most minute details
of covering and articulated parts ; in other in-
stances nothing more remains of them than
their footsteps imprinted on the wet sand or
mud which they traversed when alive, or their
coprolites (petrified dejections), containing the
unassimilated portions of the food upon which
they fed. In the lower Jura formation (the
Lias of Lyme Regis), the preservation of the
ink-bag of the sepia("0> is so wonderfully per-
fect, that the same material which the animal
employed myriads of years before to preserve
itself from its enemies, has been made to serve
as the colour wherewith to paint its likeness.
In other strata there is sometimes nothing
more than the faint impression of a bivalve
shell, and yet will this suffice, when brought
by a traveller from a far distant country, if it
be a characteristic shell (Leitmuschel, a gui-
ding-shell) ("8) to inform us of the material for-
mations which there exist, and of the other or-
ganic remains with which it was associated ; it
tells the history of the district whence it came.

The anatomical study of the ancient animal
and vegetable life of the globe extends in a
two-fold direction. The one is purely morpho-
logical in its bearings, and is especially devo-
ted to the description and physiology of the or-
ganisms ; it fills up with extinct forms the gaps
encountered in the series that still exist. The
other direction is geological, and considers fos-
sil organic remains in their relations to the su-
perposition and relative age of the sedimentary
formations. The first was long the usual di-
rection taken, and in its imperfect and superfi-
cial comparisons of petrifactions with living spe-
cies led off into erroneous ways, traces of which

82

PALiEOZOOLOGY.

are still to be discovered in the extraordinary
denominations of certain natural bodies. There
was the constant disposition to recognize a liv-
ing in every extinct species ; just as, in the
16th century, false analogies led naturalists to
confound the animals of the Old World vv^ith
those of the New Continent. Camper, Soem-
mering, and Blumenbach, had the merit, by the
scientific application of a better comparative
anatomy, of first illustrating the osteological
portion of Palaeontology (the Archaeology of or-
ganic life), in so far at least as the larger fos-
sil vertebrate animals are concerned ; but for
the proper geological consideration of the Sci-
ence of Petrifactions, for the happy combina-
tion of the zoological character with the age
and order of deposition of strata, we are in-
debted to the great work of George Cuvier and
Alexander Brongniart.

The oldest sedimentary formations, those to
wit of the transition series, in the organic re-
mains which they include, present a mixture of
forms which assume very diflerent places in
the scale of development, gradually attaining to
greater and greater perfection. Of vegetables,
they contain indeed but a few Fuci, Lycopo-
diaceae which perhaps were arborescent, Equi-
setaceae, and tropical Ferns ; but of animal re-
mains, we find, strangely associated together,
Crustacea (trilobites with reticular eyes, and
calymene), Brachiopoda (spirifer, orthis), the
elegant Spheronites, which are nearly allied
to the crinoideae("5) and orthoceratites from
among the Cephalopoda, Stone-cora!s, and with
these lower organisms, Fishes of singular forms
in the upper Silurian strata. The heavily-arm-
ed family of Cephalaspidans, fragments from
whose genus Pterychthys were long regarded
as trilobytes, belong exclusively to the Devo-
nian, or old red sandstone formation, and show,
as Agassiz says, as peculiar a type in the se-
ries of fishes as Ichthyosauri and Plesiosauri
do among the reptiles(2'°). The Goniatites,
belonging to the group of Ammonites, likewise
begin to show themselves in the transition
limestone and greywacke of the Devonian, and
even in the later members of the Silurian sys-
tem(2").

The dependence of physiological gradation
upon the age of the formation, which has hith-
erto been but little observed in the position of
the invertebrate order of animals(2"), is exhib-
ited in the most regular manner in connection
with the vertebrate series. The oldest of these,
as we have just seen, are the fishes ; and then,
following the series of formations from the in-
ferior to the superior, we come to reptiles and
mammalia. The first reptile encountered, a
saurian or lizard, and, according to Cuvier, a
monitor, which had already attracted the at-
tention of Leibnitz(=^^3), makes its appearance
in the copperslate floetz of the Zechstein [low-
er new red, or magnesian limestone formation],
of Thuringia ; and with this, and of the same
age, according to Murchison, the palaeosaurus
and the codontosaurus of Bristol. The Sau-
rians go on increasing in numbers in the Mus-
chelkalk, in the Keuper, and in the Jura forma-
tion, in which they attain their maximumC^*^*).
Contemporaneously with this formation lived
Plesiosauri, with long swan-like necks, con-
taining thirty vertebrae ; the Megalosaurus, a

crocodilian monster, 45 feet long, and with
bones of the feet like those of a heavy mam-
miferous land animal ; eight species of large-
eyed Ichthyosauri ; the Geosaurus or Soem-
mering's Lacerta gigantea ; finally, seven sin-
gularly hideous Pterodactyles(=^"), or Saurians
furnished with membranous wings. In the
chalk, the number of crocodilian Saurians falls
off, yet the epoch which this deposit charac-
terizes is distinguished by the Maestricht croc-
odile, as it is called, the Mososaurus of Cony-
beare, and the colossal, perhaps herbivorous,
Iguanodon. Other animals that belong to the
present race of crocodiles Cuvier has met with
ascending into the tertiary formations(^'*) ; and
Scheuchzer's " Man attesting the deluge (ho-
mo diluvii testis)," a great salamander, allied
to the axolotl, which I brought with me from
the Mexican lakes, belongs to the newest fresh-
water formations of Oeningen.

The relative ages of organisms determined
by the position of the rocky strata in which
their remains are found, has led to important
conclusions as to the relations that can be
traced between extinct and still existing fami-
lies and species (the latter, the species, in very
small numbers). Older and newer observa-
tions agree in showing that the floras and fau-
nas are by so much the more unlike the pres-
ent forms of plants and animals, as the sedi-
mentary formations in which their remains lie
buried belong to the inferior ; in other words,
to the older strata. The numerical relations
presented by these grand successive changes
in the forms of organic life, first pointed out by
Cuvier, have yielded decisive results through
the meritorious labours of Deshayes and Lyell,
in connection more especially with the various
groups of the tertiary formations, which con-
tain a considerable mass of carefully-studied
forms. Agassiz, who has cognizance of 1700
species of fossil fishes, and who estimates the
number of living species that have been de-
scribed, or that are preserved in museums, at
8000, speaks out quite decisively, in his mas-
ter-work. He says : " With the single excep-
tion of one small fossil fish, peculiar to the clay-
geodes of Greenland, I have found no animal of
this class in all the transition, floetz, and ter-
tiary strata, which is specifically identical with
any fish now living;" and he adds the follow-
ing important observation : " In the inferior
tertiary formations, the coarse limestone and
London clay, for example, one-third of the fos- j
sil fishes even belong to genera that are w^hoUy i
extinct ; below the chalk there is not one of ]
the genera of fishes of the present time to be
found, and the extraordinary family of the Sau-
roids (or fishes with scales covered with en-
amel, which in structure almost approach rep-
tiles, and ascend from the coal formation, in
which the largest species lie embedded, to the
chalk, where single individuals are still en-
countered), stand related to the two families
Lepidosteus and Polypterus, which now inhab-
it the rivers of America and the Nile, in the
same way as our present elephants and tapirs
to the Mastodons and Anaplotheriums of the
primeval world"^").

The chalk-beds, however, which still contain
two of these sauroid fishes, and gigantic rep-
tiles, and which present themselves as an en-

PALiGOZOOLOGY.

83

tire world of extinct corals and shells, are com-
posed, according to Ehrenberg's beautiful dis-
covery, of microscopic Polythalamia, many of
which are still to be found in our seas, particu-
larly in the middle latitudes of the North Sea
and Baltic. The first group of the tertiary
formation lying over the chalk, a group which
it has become customary to designate by the
name of the strata of the Eocene period, would
appear by no means rightly to deserve this
title — "inasmuch as the morning dawn of
the nature that still exists with us extends far
more deeply into the history of the earth than
was until lately believed"(^™).

As fishes, the oldest of all vertebrate animals,
already show themselves in Silurian transition
strata, and then occur without interruption in
all subsequent formations up to the strata of
the tertiary epoch ; as we have seen the Sau-
rians begin with the zechstein or magnesian
limestone, so are the first raammiferous ani-
mals, the Thylactotherium, Prevostii, and T.
Bucklandii, which Valenciennes regards as near-
ly allied to the Marsupialia(=^'), found in the
Stonesfield slate, a lower member of the Jura
or Oolitic formation, and- the first bird occurs
in the older cretaceous depositsC*"). These,
according to our present knowledge, are the
inferior limits of fishes, saurians, mammalia,
and birds.

But if, among the members of the inverte-
brate series of animals, stone corals and serpu-
lites are found making their appearance in the
oldest formations simultaneously with highly
developed cephalopods and Crustacea, the most
different and dissimilar orders being, therefore,
associated without distinction, we, on the oth-
er hand, discover very determinate laws in
connection with the distribution of particular
groups of the same orders. Fossil shells of the
same kinds, goniatites, trilobites, and nummu-
lites, compose entire mountains. Where dif-
ferent genera are mingled, it often happens
that not only is there a determinate sequence
of organisms recognizable, according to the re-
lations of superposition in the several systems
of strata, but the association of certain genera
and species has also been observed in the sub-
ordinate strata of the same formations. By
his happy discovery of the Law of Estimates
(Lobenstellung), Leopold von Buch has been
enabled to distribute the vast multitude of am-
monites into well-characterized families, and
shown how the ceratites belong to the mus-
chelkalk, the arietes to the lias, the goniatites
to the transition limestone and greywacke("^).
Belemnites have their inferior limits in the
Keuper -vvhich covers the Jura limestone, their
superior limits in the chalk("2). The waters
of countries far remote from one another were
inhabited at the same epochs by testaceous an-
imals, which partly at least, as' is now known
for certain, are identical with those that occur
fossilized in Europe. Leopold von Buch has
shown us exogyri and trigonia from the south- |
ern hemisphere (the volcano Maypo, in Chili), I
and d'Orbigny ammonites and gryphese from i
the Himalaya mountains and the plains of Cutch
in India, which are identical in kind with those
left behind by the old Jurassic sea of France
and Germany.

Strata characterized by determinate species

of fossils, or by determinate rolled masses
which they inclose, form a geognostical hori-
zon, by means of which the geologist, when at
a loss, can always ascertain his place, and pur-
suing which, he arrives at safe conclusions as
to the identity and relative age of certain for-
mations, the periodical recurrence of particular
strata, their parallelism, and their total sup-
pression or failure. If we will thus embrace
the type of the sedimentary formation in its
greatest simplicity and most general distribu-
tion, we find its members in the following or-
der, proceeding from below upwards.

1st. The so-called Transition rocks, in the
two divisions of inferior and superior grey-
wacke, or Silurian and Devonian systems, the
latter formerly designated the Old Red Sand-
stone formation ;

2d. The inferior Trias('*') — Mountain lime-
stone, the Coal measures together with the
Red conglomerate (Todtlregendes), and Zech-
stein or Magnesian limestone ;

3d. The superior Trias — Variegated-sand-
stone, Musehelkalk and Keuper(28*);

4th. Jura limestone (Lias and Oolite) ;

5th. Massive sandstone, Inferior and Superi-
or chalk, as the last of the floetz strata, which
begin with the mountain limestone ;

6th. Tertiary formations, in three divisions,
which are indicated by the Coarse limestone,
Brown coal or Lignite, and Sub-Apennine
gravel.

In the alluvium or drift follow the gigantic
bones of the extinct mammalia — the Masto-
dons, Dinotheriums, Missuriums, Megatheri-
ums, Owen's Sloth-like Mylodon, 1 1 feet long,
&c. With these primaeval genera are associa-
ted the fossilized remains of many animals that
still exist — the elephant, rhinoceros, ox, horse,
deer, &c. The plain near Bogota, filled with
the bones of Mastodons (the Campo de Gigan-
tes, in which I had some careful digging per-
formed) (2"), lies 8,200 feet above the level of
the sea, and the bones of extinct species of true
elephants are found still higher in the lofty pla-
teaus of Mexico. Like the chain of the Andes,
which has certainly been upheaved at very dif-
ferent epochs, the advances of the Himalaya,
the Sewalik hills (which Captain Cautley and
Dr. Falconer have so carefully examined), be-
sides the extinct Mastodon, Sivatherium, and
gigantic land tortoise, the Colossochelys, 12
feet long and 6 feet high, contain remains of
genera that still exist — elephants, rhinoceroses,
giraffes ; and this, which is very much to be
regarded, within a zone which enjoys the same
tropical climate at the present day which we
may be permitted to conjecture prevailed du-
ring the epoch of the Mastodons(=").

After having thus compared the series of in-
organic formations composing the crust of the
earth, with the animal remains which lie buried
in them, we have still to write another chapter
in the history of the organic life of the globe —
that, namely, which refers to vegetables ; and
to trace the epochs of vegetation, the floras
varying with the increasing dimensions of the
dry land, and the modifications which the at-
mosphere underwent.

The oldest transition strata, as already re-

84

PALiEOPHYTOLOGY.

marked, present us with nothing but cellular-
leaved marine plants. It is in the Devonian
strata that a few cryptogaraic forms of vascular
vegetables, calamites and lycopodiaceae, are
first encountered^"^). Nothing seems to tes-
tify, as, on theoretical views On the simflicitrj
of the first forms of organic life, it has been as-
sumed, that vegetable life was awakened sooner
than animal life, upon the face of the old earth,
and that this was brought about or determined
by that. The existence of races of men in the
very northern polar zones, who subsist on the
flesh of fish, and seals and whales, is enough
of itself to assure us of the possibility of living
without vegetable matter of any kind. After
the Devonian strata and the mountain lime-
stone, comes a formation, the botanical anato-
my of which has made such brilliant progress
in recent timesC^^^). The Coal Formation com-
prises not only fern-like cryptogamic plants,
and phanerogamous monocotyledons — grasses,
yucca-like liliaceous vegetables and palms ; it
further contains gynospermic dicotyledons —
coniferae and cycadeas. Nearly 400 species
from the flora of the coal formation are al-
ready known. I here mention only arborescent
calamites and lycopodiaceae ; scaly lepidoden-
drons ; sigillariae of 60 feet long, and occasion-
ally found standing erect and rooted, and dis-
tinguished by a double vascular fasciculate
system ; cactus-like stigmariae ; a host of ferns
now arborescent, and again mere fronds, and by
their quantity proclaiming the still entirely insu-
lar character of the dry land^^^^) ; cycadeaeC"") ;
and particularly palms(2") in small numbers,
asterophyllites with verticillate leaves, allied to
the Najades ; araucaria-like coniferae(292) with
slight indications of annual rings. The diver-
sity in character of a vegetation which flour-
ished luxuriantly on the uplifted and dry-laid
portions of the old red sandstone, from the
vegetable world of the present time, still contin-
ues through the later phytological periods on
to the last layers of the chalk(=^") ; but with a
great degree of strangeness in the forms, the
flora of the coal formation still exhibits a very
remarkable uniformity in the distribution of the
same genera (if not always of the same' spe-
cies), over every part of the then surface of the
earth; in New Holland, Canada, Greenland,
and Melville Island, the genera are still the
same.

The vegetation of the former world presents
us with forms the affinities of which with vari-
ous families of the present age remind us that
with them many intermediate members in the
series of organic developments have perished.
To quote two instances only : the Lepidoden-
dra, according to Lindley, stand between the
Coniferae and the Lycopoditeae("*) ; the Arau-
carita and Pinita, on the other hand, in the
combination of their vascular fascicles, exhibit
something that is foreign and peculiar. But
confining our views to the present order of
things, the discovery of Cycadeae and Coniferae
in the flora of the old coal measures in juxta-
position with Sagenaria and Lepidodendra, is
still of great significance. The Coniferae, to
wit, have not only relationships with the Cupu-
liferae and the Betulineae, by the side of which
we encounter them in the brown-coal forma-
tion, but they are further connected with the

Lycopoditeae. The family of the sago-like Cy-
cadeas approaches the Palms in external appear-
ance, whilst agreeing essentially with the Co-
niferae in the structure of the flowers and
fruitC^'^). Where several series of coal strata
lie over one another, the genera and species
are not always mixed ; they are rather and for
the major part generically arranged, so that
only Lycopodites and certain Ferns occur in
one series of beds, and Stigmariae and Sigilla-
riae in'gripther.

In order to form an idea of the luxuriance of
vegetation in the former world, and of the
masses of vegetable matter accumulated by
running water, and which have very certainly
been converted into coal in the humid way(^^*),
I remind the reader that in the Saarbriicic coal
field there are 120 seams of coal lying one over
another, exclusive of a host of smaller seams
less than a foot in thickness ; that there are
single seams of coal of 30 and even of more
than 50 feet thick, as at Johnstone in Scotland,
and Creuzot in Burgundy ; whilst in the forest
regions of our temperate zone, the carbon which
the trees of a certain superficial extent of
ground contain, would not cover this surface
with a layer of much more than half an inch ia
thickness (7 lines) in the course of one hundred
years(^"). Near the mouth of the Mississippi,
and in the wood hillocks, as they have been call-
ed, of the Siberian Icy Sea, described by Ad-
miral Wrangel, however, there is at the present
time such an accumulation of trunks of trees,
such a quantity of drift wood, washed down by
land streams, and brought together by ocean
currents, that the phenomena remind us at
once of the events which took place in the in-
land waters and insulated bays of the primeval
world, and gave occasion to the production of
the coal formations which we now discover
hundreds of feet below the surface of the
ground. It is also well to remember that these
coal measures are indebted for no inconsidera-
ble portion of their materials not to the trunks
of mighty trees, but to small grasses, and to
frondiferous and low cryptogamic vegetables.

The association of palms and cone-bearing
trees which we have just signalized in the coal
fields, continues through almost all the forma-
tions onwards to far into the tertiary period.
In the present world they seem rather to fly
each other's vicinity. We have, in fact, al-
though improperly, habituated ourselves so
much to regard the cone-bearers as northern
forms, that I myself, ascending from the shores
of the South Sea towards Chilpansingo and the
elevated valleys of Mexico, was somewhat
amazed when I found myself between Venta
de la Moxonera and the Alto de los Caxones,
3,800 feet above the level of the sea, riding for
a whole day through a dense forest of the Pinus
occidentalis, in which this cone-bearing tree,
so like our Lord Weymouth's or white pine,
was associated with a fan-leaved palm — the
Corypha dulcis, covered with flights of gay
coloured parrots(*'^). Southern America pro-
duces oaks, but not a single species of pine ;
and the first time that I again encountered the
familiar form of a fir-tree, it met me in the es-
tranging presence of a palm with its fan-like
leaves. In the north-east end of the Island of
Cuba, too, and so within the tropics, but scarcely

PALiEOPETROLOGY.

86

raised above the level of the sea, Christopher
Columbus in the course of his first voyage of
discovery observed coniferous trees and palms
associated in their growth("'). This gifted
and all-observing man speaks of the circum-
stance in his journal as a singularity ; and his
friend Anghiera, secretary to Ferdinand the
Catholic, says, with evident astonishment^hat
*' in the newly discovered country tl^iH^d
palmeta and pineta growing togetheT^^Jis
of the greatest interest in a geologica^^PPof
view to contrast the present distribution of
plants upon the surface of the earth with that
which the floras of the former world unfold to
us. The temperate zone of the southern hem-
isphere, abounding in water and in islands, and
in which tropical forms of vegetation mingle so
strangely with the forms that belong to colder
regions of the earth, presents us, according to
Darwin's beautiful, animated description, witH
the most instructive examples for both the old
and the new, the past and the present geogra-
phy of plants(^°*'). The primeval is in the
strictest sense of the word a portion of the his-
tory of phytology.

The Cycadeee, which, to judge by the num-
ber of species, played a much more important
part in the world that has passed away than in
that which now exists, accompany the allied
Coniferae from the epoch of the coal formation
upwards. They are almost entirely wanting
in the period of the variegated sandstone, in
which Coniferae of singular formation (Voltzia,
Haidingera, Albertia) have grown luxuriantly ;
the Cycadeae, however, attain their maximum
in the Keuper strata and the lias, where about
twenty different forms make their appearance.
In the chalk the prevailing forms are those of
marine and fresh-water plants (Fuci and Na-
jades). The cycadean forests of the Jura for-
mation have by this time been long exhausted,
and even in the older tertiary formations they
remain deep behind the cone-bearing tribes and
palms(3<'i).

The lignitic or brown-coal strata, which are
present in every one of the divisions of the
tertiary period, amongst the earliest forms of
cryptogamic land plants, exhibit a few palms,
many conifers with distinct annual rings, and
frondiferous trees, of more or less decided trop-
ical character. In the middle tertiary period
we observe the complete recurrence of the
palms and cycadeans, and in the last members
of this epoch, at length, strong resemblances
to our present flora. We come suddenly upon
our pines and firs, our cupuliferous tribes, our
planes, and our poplars. The dicotyledonous
stems of the lignite are frequently distinguish-
ed by gigantic thic"kness and vast age. A trunk
was found near Bonn, in which Noggerath
counted 792 annual rings. In the peat-moss
of the Somme, at Yseux, not far from Abbe-
ville, in the north of France, oaks have been
found that are 14 feet in diameter, a size which,
in the old hemisphere, is very remarkable be-
yond the tropics(302). Goeppert's excellent re-
searches, which it is hoped will soon appear
illustrated with plates, inform us, " that all the
Baltic amber is derived from a coniferous tree,
which, as proclaimed by the extant remains of
the wood and bark, were obviously of different
ages, came nearest to our white and red pine

timber, but still constituted a particular species.
The amber-tree of the former world (Pinites
succifer) had a richness in resin with which
none of the coniferous tribes of the present
world will bear comparison, inasmuch as great
masses of amber are contained not only within
and upon the bark, but also between the rings
of the wood and in the direction of the medul-
lary rays, which, as well as the cells, are seen
under the microscope to be filled with ambre-
ous resin of a whiter or yellower colour in dif-
ferent places. Amongst the vegetable matters
inclosed in amber we find both male and female
flowers of indigenous, acicular-leaved, and cu-
puliferous trees ; but distinct fragments of Thu-
ja, Cupressus, Ephedera, and Castania vesca,
mingled with others of Junipers and Firs, indi-
cate a vegetation which is diflferent from that
of the present coasts and plains of the BaUic
Sea."

In the geological portion of our Representa-
tion of Nature, we have now gone over the whole
series of formations, from the oldest eruptive
rocks, and the oldest sedimentary strata, to the
newest alluvium, upon which lie the great er-
ratic blocks, the causes or means of whose dis-
tribution has long been matter of discussion,
but which for my own part I am less disposed
to ascribe to icebergs, than to the eruption and
tumultuous descent of great masses of pent-up
water suddenly let loose by the upheaval of
mountain chains(2''3) -pj^^ oldest members of
the transition formation with which we are ac-
quainted, are the schists and greywacke, which
inclose some few remains of seaweed from the
Silurian, formerly the Cambrian Sea. Upon
what did these oldest rocks, as they are called,
repose, if gneiss and mica-slate are to be re-
garded but as metamorphosed sedimentary
strata ] Shall we venture a conjecture in re-
gard to that which cannot be the object of ac-
tual geological observation 1 According to an
ancient Indian Myth, it is an elephant that sup-
ports the earth ; and the elephant himself, that
he may not sink, is borne by a gigantic tortoise.
Whereon the tortoise stands, it is not allowed
to the believing Brahmin to inquire. We make
bold to attempt a problem of the sort, although
prepared for variety of blame in its solution.
On the first formation of the planets, as we
have made it probable in the astronomical por-
tion of our Picture, vaporous rings circulating
about the sun became aggregated into spheres,
and gradually consolidated from without in-
wards. What we call the older Silurian strata
are only the upper portions of the solid crust
of the earth. The eruptive rocks which we see
breaking through, pushing aside, and heaving
up these, arise from depths that are inaccessi-
ble to us ; they exist, consequently, under the
Silurian strata, composed of the same associa-
tion of minerals which are familiar to us under
the name of granite, augite, and quartz-por-
phyry, at the points where, by breaking through,
they become visible. Resting on analogies, we
may safely assume that that which at one and
the same time fills extensive fissures in the
manner of veins, and bursts through the sedi-
mentary strata, can only be an offset from an
inferior bed. The active volcanoes of the pres-
ent day carry on their processes at the greatest

86

GENERAL PHYSICAL GEOGRAPHY.

depths ; and from the strange fragnaents which
I have found included in streams of lava in dif-
ferent quarters of the globe, I also hold it as
more than probable that a primogenial granitic
rock is the foundation of the great systems of
stratification which are filled with such variety
of organic remains(^°*). If basalts, containing
olivine, first make their appearance in the cre-
taceous period, and trachytes show themselves
still later, the eruptions of granite, on the con-
trary, belong (as metamorphic productions also
assure us) to the epochs of the oldest sedi-
mentary strata of the transition series. Where
knowledge cannot take its rise from the imme-
diate scrutiny of the senses, it is fairly allow-
able, even on grounds of pure induction, as also
after a careful comparison of facts, to advance
a conjecture which restores to the olden gran-
ite a portion of its threatened rights, and its
distinction of primordiahty.

The late advances of geology, the extended
knowledge of the geological epochs, which are
characterized by the mineralogical diversity of
their rocks or mineral masses, by the peculiar-
ities and succession of the organic remains
which they contain, by the position, the erec-
tion or the undisturbed horizontal lie of the
strata, all these considerations lead us, follow-
ing the intimate causal connection of phenom-
ena, to the division, in respect of space, of the
solid and the fluid, of the continents and the
seas which constitute the surface of our planet.
And here we indicate a point of union between
that which is historical in geology with refer-
ence to the earth — cosmographical geology, and
geographical geology, or the general considera-
tion of the form and partition of continents.
The limitation of the Solid by the Fluid, and
the relations in respect of area between the one
and the other, have been very different at dif-
ferent times in the long succession of geologi-
cal epochs, according as the sedimentary car-
boniferous strata were deposited horizontally
on the upright strata of mountain lime- and old
red sand stone ; as lias and oolite were laid on
banks of kuper and muschelkalk ; and as chalk
was accumulated on the acclivities of the green
sand and Jura limestone. If, with M. Elie de
Beaumont, we designate the waters under
which the Jura limestone and the chalk were
precipitated in the shape of mud or slime, as
the Jurassic and cretaceous seas, then will the
contour of the two formations just mentioned
give us the boundary for two epochs, between
the ocean still engaged in forming rocks, and
the land already laid dry. The happy idea has
even been conceived of forming maps of these
physical elements of primeval geography ; and
these maps are perhaps more accurate than
those which have been composed in illustration
of the wanderings of lo and the Homeric narra-
tives. The latter give graphic representations
of opinions and mythical images ; the former ex-
hibit facts in the positive science of formation.

The result of investigations into the extent
of exposed area, or dry land, is this : that in
the earliest times, in the Silurian or Devonian
transition epochs, as also in the first floetz pe-
riod, throughout its tripartite division, the dry
land, the surface occupied by land plants, was
limited to separate islands ; that these islands

united at later epochs, and inclosed numerons
inland lakes by the sides of deeply-indented
bays of the sea ; that finally, when the mount-
ain chains of the Pyrenees and Apennines and
Carpathians arose — towards the time of the
older tertiary strata, therefore — extensive con-
tinents, having almost the dimensions of those
of th^^esent day, had appeared. In the times
of y^BJttjrian world, as well as in the epoch
of ^^^Hhest luxuriance of the Cycadeae and
gigaflPPcaurians, the quantity of dry land from
pole to pole might very possibly have been
even less than it is in the Pacific and Indian
Oceans at the present time. How this prepon-
derating mass of water, in common with other
causes, conduced to elevation of temperature,
and to greater equalityof climate, will be the
subject of consideration by and by. Here it
n^ust only be farther remarked, in considering
the gradual augmentation (agglutination) of the
uplifted dry land, that shortly before the revo-
lutions, which, after shorter or longer pauses
in the diluvial period, occasioned the sudden
extinction of so many gigantic vertebrate ani-
mals, portions of the present continental mass-
es were still completely separate from one an-
other. In South America and the Australasian
lands, there is a great prevailing resemblance
between the existing animals and those that
have become extinct. In New Holland, the
fossil remains of kangaroos have been discov-
ered, and in New Zealand the semifossil bones
of a gigantic struthious bird, Owen's Dinornis,
closely allied to the existing Apterix, but hav-
ing little affinity to the so lately extinguished
Dronte or Dodo of the island of Rodriguez.

The outline of former continents was perhaps
indebted in principal measure for its elevation
above the surrounding sea-level to the eruption
of quartzose porphyry, an event which so pow-
erfully shook the first great vegetable covering
of the dry land, from which were derived the
materials of the coal measures. What we call
plains or flats (in continents), are no more than
the broad backs of hills and mountains whose
feet are at the bottom of the sea. Each plain,
in its submarine relations, is, in fact, a lofty
plateau or table-land, whose inequalities have
been concealed by new sedimentary deposi-
tions in horizontal beds, as well as by alluviums
spread over its surface by floods.

Among the general considerations which be-
long to a Picture of Nature, the foremost place
must be given to the quantity of terra fir ma
projecting, uplifting itself above the level of the
sea ; such a determination of continental areas
includes the consideration of their individual
forms in point of horizontal extension (seg-
mentary relations), and of perpendicular eleva-
tion (the hypsometrical relations of mountain
chains). Our planet has two coverings or en-
velopes : one general, the Atmosphere, as elastic
fluid, and one particular, only locally distributed,
bounding the Solid, and thereby givmg it its
figure, the Sea. These two coverings, the air
and the ocean, form a natural whole which
gives the surface of the earth its climate, di-
verse according to 'the relative extent of the
sea and of the land, of the division and geo-
graphical position of the land, and of the direc-
tion and elevation of its mountain chains.

PHYSICAL GEOGRAPHY— THE LAND.

87

From this knowledge of the reciprocal influ-
ences of the air, ocean, and land it appears that
great meteorological phenomena, severed from
geological considerations, cannot be under-
stood. Meteorology, like the geography of
plants and animals, first began to make some
progress since observers have become persua-
ded of the mutual interdependence of the phe-
nomena to be investigated. The word Climate
implies in the first instance a specific constitu-
tion of the atmosphere ; but this constitution
depends on the ceaseless reciprocal influences
exerted between an ever and deeply-agitated
ocean, crossed in different directions by cur-
rents of totally dissimilar temperatures, and
the heat-radiating dry land, variously partition-
ed, elevated, coloured, naked or covered with
lofty trees or lowly herbs.

In the present condition of the surface of
our planet, the area of the dry to that of the
fluid is as 1 : 2| ; according to Rigaud(3''*), as
100 : 270. The islands form at present scarcely
■5^3 of the continental masses. The latter are
so unequally divided, that in the northern hem-
isphere they offer a three times greater extent
of surface than they do in the southern hemi-
sphere. The southern hemisphere is conse-
quently most especially oceanic in its prevail-
ing character. From 40° S. latitude on towards
the antartic pole, the crust of the earth is al-
most entirely covered with water. Even as
predominating, and only broken here and there
by insignificant clusters of islands, is the fluid
element between the east coasts of the Old and
the west coasts of the New World. The learn-
ed hydrographer, Fleurieu, by way of distin-
guishing this extensive sea basin from other
seas, has very well entitled it the Great Ocean.
Within the tropics it includes a breadth of as
many as 145 degrees of longitude. The south-
ern and western hemispheres, beginning the
reckoning from the meridian of Teneriffe, are
thus the regions of the earth's surface that
most abound in water.

These are the principal points in the consid-
eration of the relative quantities of the land
and sea, a relation which exerts so vast an in-
fl^uence upon the distribution of temperature ;
the variation of atmospheric pressure ; the di-
rection of winds, and the hygrometric state of
the air which particularly and so essentially
determines the force of vegetation. When we
think that nearly three-fourths of the surface
of the earth are covered with water(^°*), we are
less astonished at the imperfect state of me-
teorology up to the commencement of the pres-
ent century — an epoch when a considerable
mass of accurate observations on the tempera-
ture of the sea, under different parallels of lat-
itude and at different seasons of the year, was
first obtained and numerically contrasted.

The horiz(mtal figure of the land, in its most
general relations of extension, was already an
object of ingenious consideration at an early
period in the history of the Greek civilization.
It was sought to ascertain the greatest exten-
sion from east to west, and Dicearchus, ac-
cording to the testimony of Agathemeriis, found
this to lie in the latitude of Rhodes in a direc-
tion from the Pillars of Hercules to Thinae.
This is the line which was called the Parallel
of the Diaphragm of Dicearchus, the astronom-

ical accuracy of whose position (which I have
myself examined in another place) must ever
be the subject of admiration(^°^). Strabo, led
apparently by Eratosthenes, appears to have
been so thoroughly persuaded that as this par-
allel of 36°, the maximum extension of the
world, as known to him, was intimately con-
nected with the figure of the earth, fliat he fixes
the place of the continent which he prophesied
must exist in the northern hemisphere, between
Iberia ami the coast of Thinae, as also falling
under the same degree of latitudeC^""*).

If, as already remarked, considerably more
land has been raised above the level of the sea
in the one hemisphere than in the other— and
this is the case vi^hether the globe be halved in
the line of the equator, or in that of the merid-
ian of Teneriffe — the two great masses of land,
true islands surrounded by the sea on every
side, which we designate the Eastern and West-
ern continents, the Old and New Worlds, be-
side the most striking contrasts in configura-
tion at large, or rather in the position of their
greater axes, still present many points of re-
semblance in the details of their configuration,
particularly in the extent and outline of their
opposite coasts. In the Eastern division, the
prevailing direction or position of the longer
axis is from east to west (more correctly, from
south-west to north-east) ; in the Western con-
tinent, however, it is meridional, or from north
to south (more accurately, from south-south-
east to north-north-west). Both masses are cut
off towards the north in the line of the same par-
allel of latitude — generally in that of 70° ; and
to the south they both run out into pyramidal
points, which have mostly a submarine exten-
sion in the shape of islands and shoals. This
is proclaimed by the archipelago of Terra del
Fuego ; the Lagullas bank, to the south of the
Cape of Good Hope, and Van Diemen's Land,
separated from New Holland by the Bass
Straits. The Northern Asiatic coast exceeds,
or runs up beyond the parallel of 70° mention-
ed above, about Cape Taimura (78° 16' N, lat.
according to Kreusenstern), whilst from about
the embouchure of the great Tschoukotschja
river eastward, in the direction of Behrrng's
Straits, the north-eastern promontories of Asia
(Cook's East-Cape) do not reach higher than
66° 3' according to Beechey(30'). The north-
ern shore of the New Continent follows the
70th parallel pretty closely ; as both south and
north of Barrow's Straits, from Boothia-felix
and Victoria-land, all the land consists only of
detached islands.

The pyramidal figure of all the southern ter-
minations of continents belongs to the " Simil-
itudines physicae in configuratione mundi," to
which Bacon had already directed attention in
the Novum Organum, and with which Cook's
companion in his second voyage round the
world, Reinhold Forster, has connected some
very acute and interesting considerations. Pro-
ceeding from the meridian of the Island of Ten-
erifl!e eastward, we observe the southern ex-
tremities of three great continents, namely, of
Africa (the extreme of the old world), Austra-
lia, and South America, approaching the south-
pole successively nearer and nearer. New Zea-
land, which is fully twelve degrees of latitude
in length, forms a very regular intermediate

88

PHYSICAL GEOGRAPHY— THE LAND.

member lying between Australia and South
America, and also ending with an island — New
Leinster — to the south. Another remarkable
feature in the configuration of our present con-
tinents is this : that almost under the same
meridians under which the most southern
stretches of the land are made, the northern
coasts alsolhoot out and reach the highest lat-
itudes towards the arctic pole. This appears
on comparing the Cape of Good Hope and the
Lagullas bank with the North Cape, and the
peninsula of Malacca with Cape Taimura in
Siberia(3^''). Whether the poles are girded
with terra firma, or surrounded by an ocean
covered with horizontal strata of ice (consoli-
dated water), we know not. The North-pole
has been approached as high as 82° 55' N. lat-
itude ; the South-pole not higher than 78° 10'
S. latitude.

In the same way as the great continental
masses terminate pyramidally towards the
south, the like configuration is variously and
almost everywhere repeated on a smaller scale,
not only in the great Indian Ocean (the penin-
sulas of Arabia, Hindostan, and Malacca), but
also, as observed by Eratosthenes and Polybi-
us, in the Mediterranean, where the Iherian,
Italian, and Hellenic peninsulas present corre-
sponding sensible configurations(3"). Europe,
with an area of but one-fifth that of Asia, is in
like manner but a western, many-membered
peninsula of the Asiatic and almost undivided
portion of the globe ; and the climatic peculi-
arities of Europe also show that it stands to
Asia very much in the same relationship as
the peninsula of Brittany does to the rest of
France(3'2). The influence which the subdi-
visions of a continent, the higher development
of its form, exerts at once upon the manners
and whole civilization of a people, is obviously
particularly alluded to by Strabo(3"), when he
commends the "greatly diversified form" of
our small division of the globe, as an especial
advantage. Africa(^^*) and South America,
which in other respects exhibit such similari-
ties in their configuration, are those among the
great masses of land which have the simplest
outhnes of coast. It is only the eastern sea-
board of Asia, broken in upon by the currents
of the east sea (fractas ex aequore terras), that
shows variety and irregularity of outline(2^^).
Peninsulas and a succession of islands there
alternate from the equator to 60° of N. latitude.

Our Atlantic Ocean bears every feature of
a great valley. It is as if floods had directed
their shocks successively to the north-east,
then to the north-west, and then to the north-
east again. The parallelism of the opposite
coasts northward from 10° of S. latitude, their
advancing and retreating angles, the convexity
of the shores of Brazil opposite those of the
Gulf of Guinea, the convexity of Africa under
the same parallels of latitude as the deep inden-
tation formed by the Gulf of Mexico, all vouch
for this apparently bold view(3»6). In this Atlan-
tic valley, as almost everywhere else in the
configuration of great masses of land, indented
and isle-studded shores stand opposite to unin-
dented coasts. It is long since I directed at-
tention to the circumstance how remarkable in
a geological point of view was the comparison
of the west coasts of Africa and South Amer-

ica within the tropics. The deep bay-like in-
ward sweep of the African coast by Fernando
Po (4^° N. lat.), is repeated on the American
continent under 18 J ° S. lat. at the tropical
point near Arica, where (between the Valle de
Arica and the Morro de Juan Diaz) the Peru-
vian coast suddenly changes its course from
south to north into a north-western direction.
This change of direction extends in like meas-
ure to the lofty chain of the Andes, which here
proceeds in two parallel connected lines ; and
not only to the lofty plateaus near the coast(3^^),
but also to the eastern plains, the earliest seat
of human civilization in the South American
continent, where the little alpine lake of Titi-
caca is bounded by the colossal mountains,
Sorata and Illimani. Farther towards the south,
from Valdivia and Chiloe (40'^ to 42° S. lat.),
through the Archipelago de los Chonos on to
the Terra del Fuego, the curious Fiord-forma-
tion, the complication of narrow, deeply-pene-
trating bays or arms of the sea, is repeated,
which, in the northern hemisphere, we find
characterizing the west coasts of Norway and
of Scotland.

Such are the most general considerations
that suggest themselves on the configuration of
continents (the extension of the dry land in a
horizontal direction), as a survey of the surface
of our planet offers them at the present time.
We have here placed facts in juxtaposition,
analogies in form occurring in remote districts
of the earth, which, however, we do not ven-
ture to speak of as Laws of Form. When on
the flanks of a still active volcano, of Vesuvius
for example, we observe the not uncommon
phenomenon of partial upheavings of the soil,
in which small portions of the solid earth,
either before or in the course of an eruption,
permanently change their level by several feet,
and rise in penthouse-like ridges or flat eleva-
tions, we perceive how it must depend on tri-
fling accidents of intensity in the force of sub-
terraneous vapours, and in the amount of re-
sistance to be overcome, that the upheaved
parts assume this or that form and direction.
Even so may slight disturbances of the equi-
librium in the interior of our planet have deter-
mined the upheaving elastic forces to operate
towards the Northern in a greater degree than
towards the Southern hemisphere ; to throw
up the Eastern hemisphere as a broad continu-
ous mass with its principal axis running nearly
parallel to the equator, the Western and more
oceanic hemisphere, again, as a narrower band,
with its axis nearly in the plane of the meridian.

On the aetiological connection of such grand
incidents in the production of the dry land, of
similarity and contrast i:\. the configuration of
continents, there is little to be made out em-
pirically. We only know one thing : that the
efficient cause is subterraneous ; that the pres-
ent fashion of continents and islands has not
been obtained at once ; but, as has been al-
ready observed, that from the epoch of the Si-
lurian formation (Neptunian separation), on to
that of the tertiary deposits, there have been
many alternate elevations and depressions of
the surface, which, on the whole, has gradually
increased in extent, and, from numerous small-
er divisions, has coalesced into the larger

PHYSICAL GEOGRAPHY— THE LAND.

masses which we now behold. The present
configuration is the product of two causes,
which exerted their influence in succession,
one after another : firstly, a subterraneous
manifestation offeree, whose measure and di-
rection we call accidental, because we have no
means of determining them ; because, to our
understanding, they are abstracted from the
circle of necessity ; secondly, powers that are
efficient on the surface, among which, volcanic
eruptions, earthquakes, the upheaval of mount-
ain chains, and ocean currents, have played the
principal part. How totally different would
have been the state of the earth, in reference
to temperature, and, along with this, how dis-
similar the state of vegetation, of agriculture,
and of human society, had the principal axis
of the new continent lain in the same direction
as that of the old — had the Andes, instead of
being uplifted in the plane of the meridian, been
raised from east to west — had there been no
extensive tropical land radiating heat to the
south of Europe (Africa) — had the Mediterra-
« nean, which once communicated and made one
with the Caspian and Red seas, and has proved
so essential a means in promoting the civiliza-
tion of mankind, had no existence — had its bot-
tom been raised to the same level as the plains
of Lombardy and Cyrene !

The alterations in the respective levels of
the solid and fluid portions, of the earth's sur-
face— alterations which, at one and the same
time, determine the outlines of continents, and
leave dry or overflow districts of low-lying
land, are to be ascribed to a variety of causes
operating at different times. The most pow-
erful have unquestionably been : the force of
elastic vapours, which the interior of the earth
encloses : the sudden change of temperature of
great mountain chainsc^^**) ; the unequal secu-
lar loss of heat by the crust and core of the
earth, which has occasioned the wrinklings or
zigzag foldings conspicuous on many occasions
in the solid surface ; local modifications of the
force of gravitation(3i9), and, as a consequence
of these, altered curvature of a portion of the
fluid element.

That the elevation of continents has been an
actual, not a seeming one only, attributable to
the form of the surface of the sea, appears to
follow from views now adopted by geologists
generally, and from the long observation of
connected facts, as well as from the analogy
of the more important volcanic phenomena.
The merit of this view also belongs to Leopold
von Buch, who announced it in the account of
his remarkable travels through Norway and
Sweden, in the years 1806 and 1807, when it
was first introduced to science(320). Whilst
the whole of the coasts of Sweden and Finland,
from the limits of north Scania (Solvitsborg),
through Gefle, to Torneo, and from Torneo to
Abo, is rising (the rise, in the course of a cen-
tury, amounts to four feet), south Sweden, on
the contrary, according to Nilson, is sinking(32i).
The maximum of the upheaving power appears
to lie in north Lapland. The upheaval falls off
gradually towards the south as far as Calmar
and Solvitsborg. Lines of what were old sea-lev-
els within historical times, are indicated along
the coasts of the whole of Norway, from Cape
Lindesnaes to the extreme north Cape, by beds
M

of shells of the present ocean("='), and have late-
ly been most accurately measured by Bravais,
during the long winter residence at Bosekop.
These shores lie as many as 600 feet above
the present mean sea-level, and, according to
Keilhau and Eugenius Robert, the same thing
extends nor-nor-west to the coasts of Spitzber-
gen, opposite the North-cape. Leopold von
Buch, who was the first to direct attention to
the raised bed of shells near Tromsoe (69=* 40'
N. lat.), has, however, shown that the old up-
heavals along the line of the North Sea be-
long to another class of phenomena than the
smooth and gradual rising of the Swedish coasts
of the Gulf of Bothnia. The last phenomenon,
vouched for by sure historical testimony, must
not, therefore, be confounded with that altera-
tion in the level of the surface which accom-
panies earthquakes, as in the case of the coasts
of Chili and of Cutch. It has very recently
given occasion to precisely similar observa-
tions in other countries. To the rising there
occasionally corresponds, as a consequence of
the folding of strata, an obvious sinking, as
in West-(jreenland (according to Pingel and
Graah), in Dalmatia and in Scania.

If we regard it as extremely probable, that
in the earlier ages of our planet the oscillating
movements of the soil, the alternate elevations
and depressions of the surface, were greater
than they are at present, we shall be less sur-
prised at finding single spots on the face of the
globe, in the interiors of continents, that lie
deeper than the present uniform level of the
ocean. Examples of this kind are presented
by the Natron lakes, described by General An-
dreossy, the small bitter lakes of the Isthmus
of Suez, the Caspian Sea, the Sea of Tiberias,
and, above all, the Dead Sea(323). The level
of the Sea of Tiberias is 625 feet, and that of
the Dead Sea no fewer than 1230 feet lower
than that of the Mediterranean mirror. Could
the drift and alluvium that cover the rocky
strata in so many parts of the earth be all at
once removed, it would then be obvious how
much of the rocky foundation lies actually low-
er than the present sea level. The periodical,
although irregular, alternate rise and fall in
the waters of the Caspian Sea, of which I have
myself seen unquestionable traces in the nor-
thern parts of this basin(^^*), appear, like the
observations of Darwin in the Coral Ocean("^),
to proclaim, that without any proper shock or
concussion, the surface of the earth is still
susceptible of the same smooth and progress-
ive undulations which in primeval times, and
when the thickness of the consolidated crust
was much less than it is at present, were much
more general [and extensive] than they are
now.

The phenomena to which we here direct at-
tention remind us of the instability of the pres-
ent order of things, in the changes which, at
far distant intervals of time, the outline and
configuration of continents have in all proba-
bility undergone. Incidents that are scarcely
recognizable to successive generations of men,
accumulate in periods of the length of which
the movements of the heavenly bodies supply
the measure. In the course of 8000 years the
east coast of the Scandinavian peninsula has ris-
en to the extent perhaps of about 320 feet ; after

PHYSICAL GEOGRAPHY— THE LAND.

the lapse of 12,000, if the motion prove contin-
uous and equable, parts of the bottom of the
ocean that lie near the peninsula, and at the
present day are covered with 100 feet of wa-
ter, and more, will have come to the surface,
and begun to be laid dry. But what is the
brevity of these intervals compared with the
length of the geological periods, which the suc-
cession of strata in the several formations,
and the host of extinct and totally different or-
ganisms which they inclose, reveal to us ! We
have here considered the phenomenon of up-
heavement only ; but we can readily, resting
on the analogies of facts observed, in like meas-
ure figure to ourselves the possibility of the
sinking or submersion of whole districts of
country. The mean height of the level, or
non-mountainous portions of France is not
quite 480 feet. Contrasted with former geo-
logical periods, in which more extensive chan-
ges went on in the interior of the earth, we
perceive that no very long period of time were
requisite to have considerable portions of the
north-west of Europe permanently overflowed,
and presenting in its sea-board a very different
outline from that which now distinguishes it.

Risings and fallings of the solid, or of the fluid
— in their several effects so evenly balanced
that the rise of the one occasions the seeming
fall of the other — are the cause of every change
in the configuration of continents. In a gener-
al Picture of Nature, in a liberal, not one-sided,
presentment of the phenomena of nature, the
possibility at least of a diminution in the mass
of waters, of a true sinking in the mean sea-
level, must therefore be indicated. That with
the former high temperature of the surface of
the earth, with the greater water-engulfing
fissuration of its crust, with a totally different
constitution of its surrounding atmosphere,
great variations in the level of the sea may
have taken place in connection with the in-
crease or decrease of the liquid element, there
is no room left for doubt. In the actual condi-
tion of our planet, however, we are totally with-
out any direct evidence of an actual progressive
decrease or increase of the sea ; we are also
without any proof of change in the mean height
of the barometer at the sea level of the same
points of observation. From Daussy's and An-
tonio Nobile's researches, it appears that an in-
crease in the height of the barometer would of
itself be accompanied with a depression of the
sea-level. But as the mean pressure of the at-
mosphere at the level of the sea, in consequence
of meteorological causes — direction of the wind,
moistness of the air — is not the same under ev-
ery parallel of latitude, the barometer of itself
can supply no certain evidence of change in the
liquid level of our globe. The remarkable phe-
nomenon which was observed in the beginning
of the present century, when several harbours
of the Mediterranean were repeatedly left com-
pletely dry for many hours, appears to indicate
that alterations in the direction and strength
of currents, without any actual diminution in
the quantity of water, without any general de-
pression of the level of the ocean, may give
rise to local recessions of its waters, and to
permanent exposures of small portions of its
shores. From the knowledge lately obtained
of these complicated phenomena, it seems that

we must be particularly cautious in interpret-
ing them, inasmuch as effects may very readily
be ascribed to one of the " old elements," the
water, which belong of right, and in fact, to
two others, the earth and the air.

As continents, which we have hitherto delin-
eated in their horizontal extension, by their
configuration, by their external distribution and
their variously indented coasts, exert a benefi-
cial influence upon climate, commerce, and the
progress of civilization, so is there another kind
of internal subdivision effected by perpendicu-
lar elevations of the surface — by mountain
chains and lofty table lands — which have con-
sequences that are not less important. All
that occasions change, variety of form and fea-
ture, in the surface of the planet — the dwell-
ing-place of the human family — besides mount-
ain chains, great lakes, grassy steppes, and
even deserts surrounded by wooded regions as
by coasts, impresses a peculiar character on
communities. Lofty ridges covered with snow
interrupt communication, interfere with traffic ;
but a mixture of less elevated mountain mem-
bers lying apart(3'**), and of low lands, such as
the West and South of Europe, present in such
happy interchange, occasion variety in the me-
teorological processes, as well as in the prod-
ucts of the vegetable kini^dom ; and further be-
get wants, as every district even under the
same degree of latitude then falls under the
dominion of a different kind of husbandry, the
satisfaction of which arouses the activity of the
inhabitants. Thus have the dreadful convul-
sions that have ensued upon the reactions of
the interior against the exterior, upon sudden
upheavals of portions of the oxidized crust of
the earth, upon the elevation of vast mountain
chains, still proved conducive, with tranquillity
restored, with the revival of the slumbering
might of the organizing forces, to cover the dry
land of either half of the globe with a beautiful
abundance of individual forms, and to free at
least the greater portion of it from the blank
of uniformity which appears to cramp and im-
poverish both the physical and the intellectual
powers of man.

To each system(327) of these mountain chains
there is, according to the grand views of Elie
de Beaumont, a relative age to be assigned :
the upheaval of the range must necessarily fall
between the times when the erupted strata
were deposited, and those in which the hori-
zontal beds, that stretch up to the very foot of
the mountains, were laid down. The furrow-
ings of the crust of the earth, in other words,
the erections of strata which are of like geo-
logical age, appear, moreover, to attach them-
selves to one and the same direction. The
line of strike, or heaving of the strata, is not
always parallel to the axis of the chain, but
sometimes cuts it through ; so that, according
to my views(32^), the phenomenon of erection
of strata which is even found repeated in the
neighbouring level, must be older than the ele-
vation of the chain. The principal direction
of the whole of the dry-land in Europe (south-
west to north-east) is opposed to the great fis-
sure or valley which runs from north-west to
south-east, from the mouths of the Rhine and
the Elbe, through the Adriatic and Red Sea,
across the mountain system of Puschti-Koh in

PHYSICAL GEOGRAPHY— THJ». OCEAN.

91

Luristan, towards the Persian Gulf and the
Indian Ocean. Such a nearly rectangular in-
tersection of geodetical lines has exerted a
vast influence on the commercial relations of
Europe with Asia and the north-west of Africa,
as wejl as on the march of civilization along
the once more fortunate shores of the Mediter-
ranean Sea("»).

If vast and lofty mountain chains appear to
our imagination as evidences of great revolu-
tions undergone by the surface of the earth, as
boundaries of climates, as dividers and deter-
miners of the courses of rivers, as bearers of
another vegetable world, it is the more neces-
sary, by accurate numerical estimates of their
volumes, to show how insignificant, on the
whole, is the quantity of the upheaved masses
in contrast with the areas of entire continents.
The mass of the Pyrenees, for example, a chain
the mean height of whose ridges, and the ex-
tent of surface of the base which it covers,
have been ascertained by accurate measure-
ments, if distributed evenly over the area of
France, would raise the surface of that coun-
try by no more than about 108 feet. The mass
of the eastern and western Alps, spread in the
same way over the area of Europe, would only
raise the land by about 20 feet. By a laborious
calculation("0), which from its nature can only
give an extreme superior limit, in other words,
a number which may be less, but cannot be
greater th^ the truth, I have found that the
centre of gravity of the volume of the coun-
tries which in Europe and North America rise
above the level of the sea, lies at a height of
630 and 702 feet, and in Asia and South Amer-
ica, at an elevation of 1062 and 1080 feet.
These estimates show the slight elevation of
the northern regions : the vast steppes of the
Siberian levels are compensated by the enor-
mous rise of the Asiatic soil from 28p to 40°
N. lat. between the Himalaya, the north Thi-
betic Kuen-luen, and the Thianschan or Celes-
tial Mountains. We read, to a certain extent,
in the numbers found, where the Plutonic forces
of the interior of the earth have put forth their
greatest strength in uplifting continental masses.

There is nothing to assure us that these Plu-
tonic powers may not in the course of future
centuries add new members to the mountain
systems of different ages and having different
directions, which have been enumerated by Elie
de Beaumont. Wherefore should the crust of
the earth have lost the property of folding on
itself 1 Almost the last of the mountain sys-
tems that appeared, the Alps and the Andes,
have reared colossuses in Mont-Blanc and
Monte Rosa, in Sorata, lUimani and Chimbo-
razo, that do not allow us to infer any falling
off in the intensity of the subterranean forces.
Geological phenomena of all kinds indicate al-
ternating periods of activity and r^se("i).
The repose we now enjoy is only apparent.
The shocks which the surface experiences un-
der every variety of climate, and along with
every description of rock, Sweden rising in its
level, and the appearance of new eruptive isl-
ands, bear no testimony to quiescence in the
internal life of the globe.

The two coverings of the solid crust of our
planet — the liquid and the gaseous, the ocean
and the atmosphere, besides the contrasts

which arise from the great diversities in theii
states of aggregation and elasticity — also pre-
sent numerous analogies by reason of the mo-
bility of their particles, of their currents, and
their relations to temperature. The depth of
the sea and of the aerial ocean are both of thera
unknown to us. In some places under thf
tropics no bottom has been found to the sea
with 25,300 feet of line (more than a [German]
geographical mile) ; and the atmosphere, sup-
posing it, as Wollaston will have it, to be lim-
ited and so subject to undulations, may be in-
ferred, from the phenomena of twilight, to have
a nine-times greater profundity. The aerial
ocean rests partly on the solid earth, whose
mountain chains and lofty table-lands, as al-
ready said, rise up like green and wood-crown-
ed shoals ; partly on the ocean, whose surface
forms the fluctuating bottom upon which the
inferior denser and moister strata repose.

From the limits of both the atmosphere and
the ocean upwards and downwards, the aerial
and liquid strata are alike subjected to certain
laws of decrease of temperature. In the at-
mosphere this decrease is much slower than in
the ocean. Under every zone the tendency of
the sea is to preserve the temperature of its
surface in equilibrium with that of the stratum
of air which rests immediately upon it, inas-
much as the chilled particles [supposing the
temperature of the air to be the lower] sink,
[and the warmer particles, vice versa, keep their
place on the surface]. A vast series of care-
ful observations on temperature, teach us that
in the usual and mean state of its surface, the
ocean, from the equator to 58° of north and
south latitude, is somewhat warmer than the
stratum of air that rests immediately upon
it("2). On account of the decrement of tem-
perature with the increasing depth, fishes and
the other inhabitants of the sea, which, by rea-
son perhaps of the nature of their branchial and
cutaneous respiratory systems, love deep wa-
ter, are able to find the lower temperatures,
that agree particularly with them in higher lat-
itudes, under the temperate and colder zones.
This circumstance, analogous to the temperate,
even to the cold alpine atmospheres of the lofty
plateaus of the torrid zone, exerts an essential
influence on the migrations and geographical
distribution of many marine animals. The
depths in which fishes live, by the increase of
pressure they occasion, modify in like measure
the cutaneous respiration and the contents in
oxygen and azote of the air in the swimming
bladder.

As fresh and salt water do not attain their
maximum density at the same temperature,
and the saline contents of the sea cause the
thermometrical indication of greatest density
to descend, water was obtained from the abyss
of the ocean in the voyages of Kotzebue and
Dupetit-Thouars, which indicated the low de-
grees of 2 8° and 25° C. This icy temperature
of the water also prevails in the depths of the
tropical sea, and its discovery gave the first in-
formation of the existence of inferior polar cur-
rents, proceeding from either pole towards the
equator. Without such under-sea currents, the
abyss of the tropical ocean could only have a
temperature equal to the maximum of cold
which the particles of water descending locallj

93

PHYSICAL GEOGRAPHY— THE OCEAN.

from the surface radiating heat, and cooled by
the contact of the atmosphere, could acquire in
a tropical region. In the Mediterranean Sea,
as Arago acutely observes, a corresponding
great depression of temperature in the inferior
strata is only not observed, because the influx
of the deep polar stream by the Straits of Gib-
raltar, through which the Atlantic is flowing
from west to east, is encountered by a west-
ward under-current of the Mediterranean to-
wards the Atlantic.

The fluid-covering of our planet, equalizing
and tempering climates in general, where it is
not intersected by pelagic currents of colder or
warmer water, and far from the coasts of trop-
ical countries, particularly between 10° north
and 10° south latitude, may be said to exhibit
a truly wonderful equality and steadiness of
temperature over areas that are thousands of
square miles in extent(333). It has, therefore,
been said with reason(^^*), that a long- contin-
ued and careful investigation of the thermal
relations of the tropical seas would give us in-
formation in the simplest manner on the grand
and much discussed problem of the constancy
of climates, and of the temperature of the earth.
Great revolutions in the luminous disc of the
sun, were they of long continuance, would be
simultaneously reflected in the altered mean
temperature of the sea still more certainly than
in the mean temperature of the land.

The zones in which the maxima of density
(saline contents) and temperature lie, do not
coincide with the equator. The two maxima
are distinct from one another, and the warmest
water appears to form two not completely par-
allel bauds to the north and south of the geo-
graphical equator. The maximum of saline
contents was found by Lenz, in his voyage
round the world, in the Pacific, in the two par-
allels of 22° north and 17° south latitude. The
zone of least density, again, was found to lie
a few degrees to the south of the line. In the
region of the Calms, the heat of the sun can-
not occasion any great amount of evaporation,
because a stratum of air saturated with saline
vapour there sleeps unmoved and unrenewed
upon the surface of the ocean.

The surface of all the seas that communi-
cate one with another, must be regarded as
generally perfectly equal in respect of mean
elevation. Local causes, mostly prevailing
winds and currents, have, however, in particu-
lar extensively land-locked seas — the Red Sea,
for example, produced permanent, though still
inconsiderable differences of level. At the isth-
mus of Suez the level of the Red Sea is from 24
to 36 feet above that of the Mediterranean at
diflferent hours of the day. The form of the ca-
nal, (the Straits of Babelmandel), by which the
Indian Ocean communicates with the Red Sea,
being such, that the waters find a readier ac-
cess than outlet, appears to assist in producing
this remarkable permanent superior elevation
of the surface of the Red Sea, which was al-
ready known to the Ancients(^3^). The admi-
rable geodetical operations of Coraboeuf and
Delcros along the chain of the Pyrenees, have
shown that there is no appreciable difference
in the surface of equilibrium, in the sea-level,
on the north coast of Holland and at Marseilles,
of the ocean and the Mediterranean("^).

Disturbances of the Equilibrium and motions
of the mass of waters consequent on these,
sometimes irregular and transient, depending
on winds and producing Waves which in the
open ocean and far from land mount during a
storm to a height of 35 feet and more ; in oth-
er instances, regular and periodical, occasioned
by the position and attraction of the sun and
moon — the Tides ; in still other instances, per-
manent, but of unequal force, as Oceanic cur-
rents. The phenomena of ebb and flow, which
extend over every sea with the exception of
those that are very small and much land-locked,
in which the tidal wave is either little or not
at all observable, are completely explained by
the Newtonian natural philosophy, i. e. referred
to the circle of necessary effects. Each of
these periodically recurring oscillations of the
ocean, is somewhat longer than half a day. In
the open ocean they scarcely rise to the extent
of a few feet ; but in consequence of the posi-
tion and configuration of coasts and estuaries
which meet the coming tidal wave they rise in
some places to extraordinary heights — in St.
Malo to 50 feet, and in Acadia, Nova-Scotia,
to from 65 to 70 feet. " Under the supposition
that the depth of the ocean is inconsiderable
when contrasted with the semi-diameter of the
earth, the analysis of the great geometrician
Laplace, has shown how the stability in the
equilibrium of the ocean requires that the dens-
ity of its fluid should be less than the mean
density of the earth." And indeed,%s we have
seen above, the density of the oarth is five-
times greater than that of water. The high
lands of the earth, therefore, can never be over-
flowed, and the remains of marine animals
found on mountains can by no means have been
brought into such situations by former floods
or deluges produced by the position of the sun
and moon(33^). j|; jg ^q trifling tribute to analy-
sis, which in the unscientific circles of society
is presumptuously held so cheap, that Laplace's
perfected Theory of the Tides has made it pos-
sible to predict in our astronomical ephemerides
or nautical almanacks, the height of the spring-
tide to be expected at each new and full moon,
and so to forewarn the inhabitants of the coasts
of the increased danger with which they are
threatened at these seasons, particularly when
the moon is in her perigee.

Oceanic currents, which exercise so consid-
erable an influence on the intercourse of na-
tions and on the climatic relations of coasts,
are almost simultaneously dependent on a mul-
titude of very dissimilar, now greater, now ap-
parently more insignificant causes. To the
number of these belong : the progressive time
of appearance of the ebb and flow of the tidal
wave in its course round the vi'orld ; the dura-
tion and force of prevailing winds ; the density
and spagific gravity of the watery particles
modified under different parallels of latitude by
their temperature and saline impregnations('^*) ;
the horary variations of the atmospheric press-
ure, which proceed successively from east to
west with such regularity within the tropics.
The currents of the ocean present this remark-
able spectacle : that they cross it of definite
breadths in different directions, in the manner
of rivers, neighbouring unmoved watery strata,
forming the banks, as it were, of these streams.

PHYSICAL GEOGRAPHY— THE OCEAN.

93

This distinction between the portion which is
moved and that which is at rest, is most re-
markable where large quantities of sea-weed
carried along with the current permit us to esti-
mate its velocity. We occasionally observe
similar phenomena of limited currents in the
inferior strata of the atmosphere : after tem-
pests that have swept over dense forests, it
sometimes happens that the trees are only found
shattered and blown down in the course of nar-
row strips.

The general motion of the sea between the
tropics from east to west, entitled the equato-
rial current, is regarded as a consequence of
the advancing times of the tides and of the
trade winds. It alters its direction in conse-
quence of the resistance of the east coasts of
the continents which it encounters in its prog-
ress. The new results w^hich Daussy has ob-
tained from the motion of bottles thrown out
on purpose by navigators (10 French sea miles,
of 925 toises each, every 24 hours), argees to
within Jgth of the velocity which I had ascer-
tained from a comparison of earlier data("').
In the log-book of his third voyage (the first in
which he sought to make the tropics in the me-
ridian of the Canaries), Christopher Columbus
says : " I hold it as certain that the waters of
the sea move with the heavens {las aguas van
con los cielos),^^ that is to say, from east to west,
like the apparent motion of the sun, moon, and
stars(3*o).

The narrow currents, true oceanic rivers,
which take their way through the sea, run
warmer water in higher, colder water in lower
latitudes. To the first class belongs the cele-
brated Gulf-stream("'), which was known to
Anghiera(3<2), and particularly to Sir Humfrey
Gilbert in the 16th century. The commence-
ment and first impulse of this mighty current
is to be sought for southAvard from the Cape
of Good Hope, and it debouches from the Ca-
ribbean Sea and the Gulf of Mexico, through
the Straits of Bahama ; running from south-
south-west to north-north-east, getting farther
and farther from the shores of the United States
of America, it turns off eastward by the banks
of Newfoundland, crosses the Atlantic, and
frequently throws the seeds of tropical plants
(Mimosa scandens, Guilandina bonduc, Doli-
chos urens), upon the coasts of Ireland, the
Hebrides and Norway. The north-eastern
prolongation of the Gulf-stream contributes to
moderate the cold of the sea-water and also of
the climate about the north Cape of Scandina-
via. The warm Gulf-stream, after it has turn-
ed eastward from the banks of Newfoundland,
at no great distance from the Azores, sends
off a branch to the south, and it is here that
the Sargasso-sea, as it has been called, the
great bank of sea-weed, is met with, which
made so lively an impression on the imagina-
tion of Columbus, and which Oviedo called the
sea-weed meadow (Praderias de Yerva). A
host of small marine animals inhabit this ever-
verdant mass of Fucus natans, one of the most
widely diffused of the social plants of the
ocean, which is constantly drifted hither and
thither by the tepid winds that blow across its
surface.

In contrast to the Gulf-stream, which belongs
almost exclusively to the northern hemisphere

I of the Atlantic valley, and runs between Amer- ^
' ica, and Europe and. Africa, is the great cur-
rent of the Pacific Ocean, the inferior tempera-
ture of whose waters has an appreciable influ-
ence on the climate of the sea-boards along
which it sweeps, as I first observed in the au-
tumn of 1802(3*3). This currenr, in fact, brings
the dolder water of high southern latitudes to
the coast of Chili, runs along the shores of this
country and those of Peru, first from south to
north, and then (from the bay of Arica) from
south-south-east to north-north-west. In the
middle of the tropics at certain seasons of the
year the water of this cold ocean stream is not
higher than 15° 6 C. (60° 0 F.), whilst the motion-
less water beyond its limits is as high as from
27° 5 to 28° 7 C. (81° 5 to 84° 6 F.). Where
the sea-board of South America, southward
from Payta, advances farthest to the west, the
stream turns suddenly in the same direction
from off the land, and takes a course from east
to west ; so that he who sails northward [by
crossing the stream] comes suddenly from a
colder to a warmer sea.

It is not known to what depth the oceanic
currents, whether hot or cold, extend, how
near they run to the bottom. The deviation of
the South African current produced by the La-
gullas bank, where the water is full 70 or 80
fathoitis deep, appears to indicate a considera-
ble extension in depth. Sand-banks and shoals
outside the streams are mostly recogniza-
ble, as the excellent Benjamin Franklin dis-
covered, by the coldness of the water over
them. This depression of temperature appears
to me to be connected with the circumstance,
that with the communication of motion to the
neighbouring ocean, deep cold water is made
to rise over the edges of the banks and to mix
with the upper warmer water. My immortal
friend. Sir Humphrey Davy, on the other hand,
ascribed the phenomenon, from which the sea-
man can frequently draw practical inferences
conducive to his safety, to the descent of the
superficial strata of water cooled in the course
of the night : these remain nearer the surface,
because the shoal prevents them from sinking
to a greater depth. The thermometer was
turned by Franklin into a plumb-hne ; fogs are
frequent upon banks and shoals : their colder
water causes precipitation of the vapour that
is dissolved in the sea air. I have observed
such fogs to the south of Jamaica, and also in
the Pacific, indicating the outline of shoals
sharply and quite distinctly from a distance.
They present themselves to the eye like air-
pictures, in which the fashion of the sub-mari-
time bottom is reflected. A still more remark-
able influence of these cold shallows is this,
that they produce an obvious effect upon the
superior strata of the atmosphere, almost in the
same way as low coral or sandy islands. Far
from all land, in the high seas, when the air is
elsewhere quite clear, clouds are frequently
seen hovering over the spots where shoals oc-
cur. In such cases their jjearings can be taken
by the compass, precisely as if they were lofty
mountains or isolated peaks.

Without the variety of external forms that
characterize the surface of continents, the
ocean, when its interior is narrowly scanned.

94

THE ATMOSPHERE.

^ presents a greater mass of organic life than is
perhaps to be found collected together in any
other portion of the earth's surface. Charles
Darwin observes with justice, in the interest-
ing Journal of his extensive sea-voyage, that
our woods on shore do not harbour so many
animals as the woody regions of the ocean,
where the sea-weed groves, rooted to the bot-
tom of the shallows, or the fuci detached by
waves and currents, supported by air-cells and
swimming free, unfold their delicate arms and
branches. The use of the microscope increases
still farther, and in the most remarkable man-
ner, the impression of the universal life of the
ocean, the astounding assurance that here sen-
sibility is everywhere diffused and active. In
depths that surpass the height of our most lofty
mountains, every one of the several superposed
strata of waters, is animated with its own Poly-
gastric worms, Cyclidia, and Ophrydia. Here
swarm, turning each wave into luminous foam,
and attracted to the surface by particular weath-
er-influences, the innumerable host of small
light-flashing Mammaria from the Orders of the
Acalephee, Crustacea, Peridinia, and Nereides
moving in circles.

The abundance of these small animals, and
of the animal matter which their rapid destruc-
tion supplies, is so immeasurable, that the sea-
water at large becomes a nutritious fltiid for
much larger creatures. If this exuberance of
living forms, these myriads of dissimilar nAi-
croscopical, and yet in ^art extremely perfect
organisms, engage and pleasantly excite the
fancy, this is appealed to in a more earnest, I
might say a more solemn manner, by the sense
of the Limitless and the Immeasurable, w^hich
every sea-voyage presents to our contempla-
tion. He who is awakened to a spiritual self-
activity, and who delights to build up a world
within himself, fills the amphitheatre of the
boundless ocean with the lofty image of the
Infinite and the Endless. His eye is fixed
especially by the far horizon, where indefinite-
ly and as in mist, the ocean and the air meet
bounding one another, in which the stars set and
rise anew before the eyes of the beholder. .But
still, with the eternal play of this interchanging
scene, as everywhere else with human happi-
ness, there comes the breath of sadness, of un-
gratified longing, to mix itself with the joy.

A peculiar predilection for the sea, grateful
remembrances of the impressions which the
mobile element between the tropics, in the
peace and silence of the night, or roused and
at war with the natural forces, has left upon
my mind, could alone have induced me to speak
of the individual enjoyment of the prospect, be-
fore referring to the beneficial influence which
contact with the ocean has had on the devel-
opment of the intelligence and character of va-
rious nations ; on the multiplication by its
means of the bonds that ought to embrace the
whole of the human family ; on the possibility
it has aflx)rded of attaining to a knowledge of
the- configuration qf the earth and its parts ;
lastly, on the improvement it has led to in as-
tronomy, and in the mathematical and natural
sciences at large. A portion of this influence
was originally confined to the waters and the
shores of the south-western parts of Asia ; but
from the 16th century onwards it has extended

far and wide, and even attained to nations that
live in the interior of continents remote from
the sea. Since Christopher Columbus was
" sent forth to unchain the ocean'X^'**) (for so
was he addressed in a dream by an unknown
voice whilst he lay on a sick-bed by the river
Belem), man, too, mentally more free, has ven-
tured with greater boldness into unknown re-
gions.

The second and most external and univer-
sally diffused of the coverings of our globe, the
Atmosphere, on whose depths, or shoals, which
are lofty table-lands and mountains, we live,
present six classes of natural phenomena, con-
nected in the most intimate manner with one
another ; these are : chemical composition ;
alterations in the transparency, polarization,
and colour ; in the density or pressure ; in the
temperature, humidity, and electricity. If in
its oxygen the air contains the first element of
physical animal life, another excellence, it
might almost be said of a higher order, must be
indicated in its constitution. The air is the
" carrier of sound," and so also the bearer of
speech, the means of communicating ideas, of
maintaining social intercourse among men. The
earth, robbed of its atmosphere, like the moon,
presents itself to the imagination as a desert
brooded over by silence.

The relations of the substances which be-
long to the strata of the atmosphere that are
accessible to us, have, since the beginning of
the 19th century, been made the object of re-
searches, in which Gay Lussac and I took an
active part ; it is but very recently, however,
through the admirable labours of Dumas and
Boussingault, that the chemical analysis of the
atmosphere, pursued in new and trustworthy
ways, has been advanced to a high degree of
perfection. From this analysis dry air appears
to contain per volume 28-8 oxygen, and 792
azote ; besides from 2 to 5 ten thousands of
carbonic acid, a still smaller quantity of carbu-
retted hydrogen(3*5), and from the important
experiments of Saussure and Liebig, traces of
ammoniacal vapours(^"), which may supply
plants with their azotized constituents. That
the quantity of oxygen may vary in a trifling
but still appreciable degree according to season,
situation of a place — upon the sea or in the in-
terior of a continent — has been rendered prob-
able by some observations of Lewy. It is con-
ceivable that changes in the quantity of oxygen
held in solution by water, induced by micro-
scopical animal organisms, may be followed by
changes in the strata of air that lie in immedi-
ate contact with its surface(^*^). The air col-
lected by Martins on the Faulhorn at a height
of 8226 feet, did not contain more oxygen than
the air of Paris(3*8).

The admixture of carbonate of ammonia in
the atmosphere may probably be held as older
than the existence of organic beings on the sur-
face of the earth. The sources of the carbon-
ic acid of the atmosphere are extremely nu-
merous(^*'). We may here mention the res-
piration of animals, which receive the carbon
they exhale from the vegetable food they con-
sume, as vegetables themselves derive it from
the atmosphere ; the interior of the earth in
the country of extinct volcanoes and thermal

THE ATMOSPHERE— PRESSURE.

95

springs ; the decomposition of the slight ad-
mixture of carburetted hydrogen contained in
the atmosphere, by the electrical discharges of
the clouds, so frequent in intertropical coun-
tries.

Besides the substances which have just been
mentioned, and which may be held proper to
the atmosphere under all circumstances and in
all situations, there are other accidental mat-
ters associated with it, which occur especially
near the ground, and of which several, desig-
nated miasms and contagions, affect the animal
system prejudicially. The chemical nature of
these substances has not yet been made known
by any immediate analysis ; but, considering the
putrefactive processes which proceed inces-
santly on the surface of our planet, covered as
it is with animal and vegetable matters, and led
as well by combinations and analogies derived
from the domain of pathology, we may fairly
conclude on the existence of such injurious lo-
cal admixtures. Ammoniacal and other azo-
tized vapours, sulphuretted hydrogen, combi-
nations, indeed, resembUng the multibasic, (ter-
nary and quarternary), compounds of the vege-
table kingdom("°), may form miasmata, which,
in a variety of shapes, and by no means only
on naked swampy bottoms, or on sea-coasts
strewed with putrifying molluscs, or covered
with under-growths of mangrove (Rhizophora),
and Avicenniae, may produce fevers of aguish
or typhoid types. Fogs which diffuse a pecu-
liar smell, remind us at certain seasons of the
year of such accidental contaminations of the
lower strata of the atmosphere. Winds and
ascending currents of air occasioned by tlie
heating of the surface, raise even solid, though
of course finely pulverized substances, to con-
siderable heights. The dust, which makes the
air misty over a great area, and falls about the
Cape de Verd Islands, to which Darwin has so
properly directed attention, is found from Eh-
renberg's observations to contain an infinity of
silicious shelled infusory animalcules.

As principal features in a general physical
picture of the atmosphere, we may distinguish,
1st. In the variations of the air's pressure : the
regular, and between the tropics, so readily ap-
preciable hourly oscillations, a kind of ebb and
flow of the atmosphere, which cannot be as-
cribed to the attraction of the mass of the
moon("^), and which is so different according
to the latitude, the season of the year, and the
height of the place of observation above the
level of the sea. 2d. In the climatic distribu-
tion of heat : the influence of the relative posi-
tion of the transparent and opaque masses —
the fluid and solid superficial areas, as well as
of the hypsometrical or perpendicular configu-
ration of continents, relations which determine
the geographical position and curvature of the
isothermal lines* in the horizontal or vertical
direction, in the ground-plane, or in the aerial
strata lying one above another. 3d. In the dis-
tribution of the moisture of the atmosphere :
the consideration of the quantitative relations
according to diversity in the solid and oceanic
surfaces, distance from the equator, and height
above the level of the sea ; the forms in which
precipitation of the watery vapour takes place,

* Lines of equal mean temperature.

and the connection of this precipitation with
the changes of temperature, and the direction
as well as the succession of the winds. 4th.
In the relations of the aerial electricity, whose
primary source, when the air is serene, is still
much disputed : the relation of ascending va-
pours to the electrical charge and the fashion
of clouds according to the time of the day and
the season of the year, the colder or hotter
zones of the earth, the lower or higher-lying
plains ; the frequency and rarity of storms ;
their periodicity and occurrence in summer and
winter; the casual connection of electricity
with the extremely rare occurrence of hail-
showers by night, as also with water-spouts
and sand-spouts, which have been so ably in-
vestigated by Peltier.

The horary variations of the barometer, in
which within the tropics the instrument is twice
in the course of the day at its highest, viz., at
9 or 94 A. M. and 10 or 10| p. m., and twice at its
lowest, viz., at 4 or ^ p. m., and 4 a. m., nearly
the hottest and coldest hours in the round of
the twenty-four, consequently, long formed the
subject of my most careful daily and nightly ob-
servations(3^2). The regularity of these is so
great, that the time, especially in the day, may
be ascertained by the height of the column of
mercury, without an error on the average of
more than from fifteen to seventeen minutes.
In the torrid zone of the New Continent, on the
coasts as well as on heights of more than 12,000
feet above the level of the sea, where the mean
temperature falls to 7= C (43° 8 F.), I have not
found the regularity of this ebb and flow of the
atmosphere to be disturbed either by tempests
of thunder or of wind, by rain or by earthquakes.
The amount of the daily fluctuation diminishes
from the equator on to 70° N. latitude (a par-
allel under which we possess very accurate ob-
servations made by Bravais at Bosekop) (3"),
from 1-32 line, to 0 18 line. That, much near-
er the pole, the mean height of the barometer
is actually less at 10 a. m. than at 4 p. m., so
that the times of the maxima and minima are
severally interchanged, is by no means to be
concluded from Parry's observations at Bowen
Harbour (73° 14' N. latitude).

The mean height of the barometer, by reason
of the ascending current of air, is somewhat
less under the equator, and especially under the
tropics, than in the temperate zone{^^*) ; it ap-
pears to attain its maximum, in the West of
Europe, in the parallels of 40° and 45°. If,
with Kaemtz, we connect those places which
present the same mean differences in their
monthly barometrical extremes by isobaromet-
rical lines, curves are engendered, the geograph-
ical position and direction of which yield us im-
portant conclusions in regard to the influence of
the configuration of continents, and the expanse
of seas upon the oscillations of the atmosphere.
Hindostan, with its lofty mountain ranges and
triangular-shaped peninsula, the East coasts of
the New Continent, at the point where the
warm gulf-stream turns eastward by New-
foundland, show greater isobarometrical fluctu-
ations than the West India Islands, and the
Western parts of Europe. Prevailing winds
exert the most especial influence on the dimi-
nution of the atmospheric pressure, and with
this, according to Daussy, as we have already

96

THE ATMOSPHERE— CLIMATE.

observed, the mean height of the sea is increas-
ed(3").

As the whole of the most important varia-
tions in the weight or pressure of the atmo-
sphere— whether they occur regularly at certain
hours and seasons, or are accidental and ex-
cessive, when they are often accompanied with
danger(^**) — like all the rest of what are called
weather phenomena, have their principal cause
in the heating power of the sun's rays ; so the
directions of the wind (partly on Lambert's
proposition) were at an early period compared
with the state of the barometer, with variations
in temperature, and with differences in the hy-
grometric state of the atmosphere. Tables of
the pressure of the atmosphere along with par-
ticular winds, designated by the title of baro-
metrical wind-cards, have given a deep insight
into the connection of meteorological phenom-
ena(35^). With wonderful acumen, Dove per-
ceived, in the laws of the rotation of the winds
of both hemispheres, which he discovered, the
cause of many grand variations (processes) in
the atmospheric ocean(^^^). The thermal dif-
ference between countries lying near the equa-
tor and those situated near the pole, engenders
two opposite currents in the upper regions of
the atmosphere and on the surface of the
earth. In consequence of the diversity of the
rotatory velocity in the parts lying nearer the
pole, or nearer the equator, the air which is
streaming from the pole acquires an eastern,
that which is pouring along from the equator a
western direction. From the struggle between
these two currents, the place of descent of the
higher, the alternating displacements of the
one by the other, depend the most important
phenomena of atmospheric pressure, of the
heating and cooling of the aerial strata, of the
precipitation of moisture, and, indeed, as Dove
has correctly shown, of the formation of clouds
and their configuration. The forms of clouds,
those all-enlivening ornaments of the land-
scape, are faithful indications of what is going
on in the upper regions of the air ; and in
calms, and floating in the warm summer's sky,
they are also the " projected image" of the
heat-radiating surface of the ground.

Where the influence of the radiation of heat
is conditional on the relative position of great
continental and oceanic surfaces, as betwixt the
East coast of Africa and the West coast of the
peninsula of Hindostan, regular periodical chan-
ges in the direction of the winds accompany
the changes in the declination of the sun, and
constitute the Indian monsoons(^^^), the Hippa-
los of the Greek navigators. These winds
must have been amongst the earliest regular
winds recognized and taken advantage of by
mankind. In this knowledge of the monsoons,
which has certainly been spread over China
and Hindostan, the Eastern, Arabian, and
Western Malayan Seas, for thousands of years,
as well as in the still older and more generally
diffused observation of the sea and land breeze,
lies the hidden germ of the fast-advancing me-
teorological science of the present day. The
long series of magnetic stations which have
now been established from Moscow to Pekin,
through the whole of Northern Asia, as they
have it also in charge to observe meteorologi-
cal phenomena in general, will soon become of

great importance in establishing the Law of
THE Winds. The comparison of observations
made simultaneously at places many hundreds
of miles apart, will determine whether or not
the same east wind blows from the barren ta-
ble-lands of Gobi to the interior of Russia, or
whether, and at what point in the line of sta-
tions, the direction of the current becomes
changed through a descent of air from the high-
er regions. We shall then, in the true sense
of the phrase, learn " whence the wind cometh."
If we would base the required result on obser-
vations continued for not fewer than twenty
years, Mahlman's careful notifications assure
us that in the middle latitudes of the temperate
zone in both continents the west- south-west is
the prevailing wind.

Our knowledge of the distribution of heat
in the atmosphere has gained, in some respects,
in clearness, since attempts have been made
to connect the points that indicate the mean
temperature of the year, of the summer and of
the winter, by different orders of lines. The
system of Isothermal, Isotheral, and Isochim-
enal lines, which I first proposed in 1817, may,
perhaps, when it has been gradually perfected
by the united efforts of natural philosophers, be
found to supply a general and grand basis for
a comparative Climatology. Terrestrial mag-
netism first acquired a scientific shape when
scattered partial results were connected graph-
ically with one another by lines of equal varia-
tion, of equal dip, and of equal intensity.

The expression Climate, in its most general
acceptation, indicates every change in the at-
mosphere which sensibly affects our organs — ■
temperature, humidity, alteration of barometri-
cal pressure ; calms or storms of wind from va-
rious quarters ; amount of electrical tension ;
purity of atmosphere, or its contamination with
gaseous exhalations more or less pernicious ;
finally, degree of habitual transparency and se-
renity of the sky, which is not merely impor-
tant in connection with the amount of radia-
tion from the ground, the organic evolution of
plants, and the ripening of fruits, but also with
the feelings and whole mental estate of man-
kind.

Were the surface of the earth composed of
one and the same homogeneous fluid mass, or
of rocky strata of like colour, like density, like
smoothness, like capacity of absorption for the
sun's rays, and like power of radiation into
planetary space, then would the Isothermal,
Isotheral, and Isochimenal lines run parallel to
one another, and to the Equator. In such an
hypothetical condition of the earth's surface,
the power of absorbing and of emitting light
and heat would be the same in the same paral-
lel of latitude all round the globe. And it is,
in fact, from such a mean, and, as it were, pri-
mary condition, which neither excludes the
transmission of heat to the interior of the
earth, nor towards the atmosphere involving
it, nor the communication of heat by currents
of air, that the mathematical consideration of
climates sets out. All that alters the absorb-
ing and radiating powers of the surface in par-
ticular parts lying in the same parallels of lati-
tude, produces inflections in the Isothermal
lines. The nature of these inflections, the
angle under which the isothermal, isotheral,

THE ATMOSPHERE— CLIMATE.

97

and isochimenal lines cut the parallel circles,
the portion of the convexities or concavities
of these lines in respect of the pole of the cor-
responding hemisphere, are the effects of calo-
rific or frigorific causes which show themselves
possessed of more or less power under differ-
ent geographical longitudes.

The progress of Climatology has been favour-
ed in a remarkable manner by the spread of
European civilization from two opposite sea-
boards, by its extension from our Western Eu-
ropean coast to an Eastern coast on the other
side of the great Atlantic vallet- When the
British, after the temporary establishments
which had proceeded from Iceland and Green-
land, had founded the first permanent colonies
on the shores of the United States of America,
where religious persecution, fanaticism, and
love of freedom, soon swelled the ranks of the
settlers, the bold adventurers must have been
amazed at the severity of the winters which
they encountered, from North Carolina and
Virginia to the River St. Lawrence, in com-
parison with those which prevail under corre-
sponding parallels of latitude in Italy, France,
and Great Britain. Such climatic observations,
however exciting they must have been, still
only bore fruits when they could be based on
numerical results of mean annual temperatures.
If, between the parallels of 58° and 30° N. lati-
tude we compare Nain, on the coast of Labra-
dor, with Gottenburg, Halifax with Bordeaux,
New York with Naples, St. Augustin in Florida
with Cairo, we find the differences in mean an-
nual temperature between the East of America
and the West of Europe, under similar paral-
lels of latitude, progressing from north to south,
from ll°-5, 7° -7 and 3°-8 to almost 0 Cent.
The gradual decrease of difference in the above
series, through 28 degrees of latitude, is very
remarkable. Still farther to the south, and
within the tropics, the isothermal lines in al-
most every part of both divisions of the globe
run parallel with the equator. From the ex-
amples here given, it is obvious that the ques-
tions we hear so constantly repeated in our
social circles, as to how many degrees Amer-
ica— and without any distinction of East or
West coast — is colder than Europe] and how
many degrees the mean annual temperature in
Canada and the United States of America is
lower than under corresponding parallels of
latitude in Europe 1 when taken as general ex-
pressions, are totally without meaning. The
difference under each particular parallel is dif-
ferent from what it is under every other paral-
lel ; and without special comparisons of the
winter and summer temperatures of the oppo-
site coasts, no right conception can be formed
of the several particular climatic relations in
so far as they influence agriculture, trade, and
the feelings of comfort and convenience, or the
contrary.

In enumerating the causes that may produce
disturbances in the form of the isothermal lines,
I distinguish the causes tending to exalt, and
the causes tending to depress teAperature. To
the first class belong : the vicinity of a west
coast in the temperate zone ; the configuration
of a continent cut up into numerous peninsu-
las ; deep bays, and far-penetrating arms of the
sea ; the right position of a portion of dry land
N

— i. c. its relatiojis cither to an ocean free from
ice which extends beyond the polar circle, or
to another continent of considerable extent
which lies between the same meridional lines
under the equator, or, at all events, in part
within the tropics ; farther, the prevalence of
southerly and westerly winds on the western
confines of a continent in the northern tem-
perate zone ; mountain chains, which serve as
screens against winds from colder countries ;
the rarity of swamps, which continue covered
with ice through the spring, and even some
way into summer ; the absence of forests on a
dry sandy soil ; finally, the constant serenity
of the heavens in the summer months, and the
neighbourhood of a pelagic stream of running
water of a higher temperature than that of the
surrounding sea.

To the second class of causes, or those that
tend to depress the mean annual temperature
by exciting cold, I enumerate : the elevation of
a place above the sea level, without any thing
like remarkable elevated plains surrounding it ;
the vicinity of an eastern coast in high and
middle latitudes ; the massive or unbroken out-
line of a continent without indentation of its
coasts and deep sea bays ; the wide extension
of the land towards the poles up to the region
of eternal ice (without the intervention of a
sea open in winter) ; a geographical position
in longitude of such a kind that the equatorial
and tropical regions belong to the ocean — in
other words, the absence of a heating, radia-
ting tropical country between the same merid-
ian lines as the country whose climate is to be
determined ; mountain chains whose form and
direction are such that they prevent the access
of warmer winds ; or the neighbourhood of iso-
lated summits down whose slopes cold currents
of air descend ; extensive forests, which hinder
the sun's rays from reaching the ground, whose
appendicular organs (the leaves), by their vital
activity, throw off large quantities of watery
vapour, and vastly increase the amount of ra-
diating or cooling superficial surface, and so
act in a threefold manner — by shading, by
evaporating, and by radiating ; great swamps,
which, up to the middle of summer, in the
north, form a kind of subterraneous glacier in
the flats; a misty or overcast summer sky,
which diminishes the effect of the sun's rays
by intercepting them in their passage to the
earth ; finally, a very clear winter's sky, by
which radiation is favoured(2*'').

The simultaneous activity of disturbkig,
whether heating or cooling causes, determines
as a total effect the inflexions of the isothermal
lines projected upon the surface of the earth,
their course being especially influenced by the
relations of extent and configuration bettveen
the opaque continental and the. fluid oceanic
masses. The perturbating causes engender
convex or concave summits of the isothermal
curves. But there are disturbing causes of
different orders, each of which must first be
separately considered ; subsequently, in order
to ascertain the whole effect upon the motion
(direction or local curving) of the isothermal
lines, it must be discovered which of the sev-
eral influences in their combinations modify,
annul, or strengthen each other, as happens in
the case of other small oscillations that meet

98

THE ATMOSPHERE— CLIMATE.

and intersect each other. Such is the spirit of
the method, by which I flatter myself it will
one day become possible to connect immeasu-
rable series of apparently isolated facts with
one another, by empirical numerically expressed
laws, and to demonstrate the necessity of their
mutual dependence.

As we find westerly or west-south-westerly
winds in both temperate zones as the prevail-
ing counter-currents to the trades or east winds
of the tropics, and as these, to a country with
an eastern sea-board, are land winds, and to a
country with a western sea-board again are
sea winds (z. e. as they blow over a level, which
by reason of its mass and the descent of the
cooled particles of water is susceptible of no |
great degree of chilling) ; so comes it that,
where oceanic currents running near the shore '
do not influence the temperature, the east
coasts of continents are colder than the west
coasts. Cook's junior companion in his second
voyage, the gifted George Forster, whom I have
to thank for urging me on to various extensive
undertakings, was the first who directed par-
ticular attention to the difference of tempera-
ture of the east and west coasts in both hemi-
spheres, as well as to the correspondence be-
tween the temperature of the west coasts of
North America in the middle latitudes, with
that of the west of Europe within the same
parallels(3").

Accurate observations show a striking differ-
ence even in pretty high northern latitudes
between the mean annual temperature of the
east and west sea-boards of America. At Nain
in Labrador (57° 10' N. lat.) this temperature
is 3° 8 C [5°16 F.] under the freezing point of
water [i. e. 26°-8 F.], whilst at New Archangel
on the north-west shore of Russian America
(57'' 3' N. lat.) it is still 6°-9 C. [12°-4 F.] above
the freezing point [i. e. 44° -4 F.]. At the first
named place the mean summer temperature
scarcely reaches 6° -2 C. [43° 1 F.], whilst at
the second it is as high as 13°-8 C. [56°-5 F.].
The mean winter temperature of Pekin (39° 54'
N. lat.) is at least 3° C. below the freezing point ;
whilst in the west of Europe, even at Paris
(48° 50' N. lat.), it is fully 3° -3 C. above this
point. The mean winter cold of Pekin is thus
lower by 2° 5 C. than that of Copenhagen,
which lies 17 degrees of latitude farther to the
north.

We have already spoken of the extreme
slowness with which the great masses of the
ocean follow alterations in the temperature of
the air, and how in virtue of this property the
ocean acts as an equalizer of temperature. It
tempers at once the rudeness of the winter's
cold and the fervour of the summer's heat.
Frohi hence a second important contrast : the
difference between the insular or sea-board cli-
mates which all deeply indented continents
abounding in bays and peninsulas enjoy, and
the climates of the interior of great masses of
terra firma. This remarkable contrast, in the
variety of its phenomena, in its influence on
the power of vegetation, and the improvement
of agriculture, on the transparency of the at-
mosphere, the radiation of the earth's surface
and the height of the line of perpetual snow,
was first fully developed in the writings of
Leopold von Buch. In the interior of the Asi-

atic continent, Tobolsk, Barnaul on the Obi
and Irkutsk, have summers like those of Ber-
lin, Munster and Cherbourg in Normandy ; but
these summers are followed by winters in which
the coldest month reaches the fearful mean
temperature of from —18° to —20° C. [0° 4 to
— 4^ F.]. In the summer months, again, the
thermometer for weeks together is seen stand-
ing at 30° and 31° C. [86° and 87°-8 F.]. Such
continental climates are therefore well and prop-
erly characterized as excessive by Buffon, who
was so well versed both in mathematics and
in physics ; artd the inhabitants of the countries
where they prevail, seem doomed, like the un-
fortunates in Dante's Purgat()ry("'^),

" a soffrir tormenti caldi e geli."*

In no quarter of the globe, not even in the
Canary Islands or in Spain, or the South of
France, have I met with more delicious fruit,
particularly more beautiful grapes, than in As-
trachan, near the shores of the Caspian Sea
(46° 21' N. lat.). With a mean annual temper-
ature of about 9° C. [about 48^° F.], the mean
summer temperature rises to 21°-2 C. [70°1
F.], equal to that of Bordeaux ; whilst not only
there, but still farther to th« south, at Kislar
on the mouth of the Texel, in the latitudes of
Avignon and Rimini, the thermometer in the
winter season sinks to — 25° and — 30° C.
[—13° and —22° F.]

Ireland, Guernsey and Jersey, the Peninsula
of Brittany, the coasts of Normandy, and the
South of England, in the mildness of their win-
ters and the low temperature and overcast sky
of their summers, present the most remarkable
contrasts with the continental climate of the
interior of the east of Europe. In the north-
east of Ireland (54° 56' N. lat.), under the same
parallel as Konigsberg in Prussia, the myrtle
grows as vigorously as it does in Portugal.
Th& month of August, the temperature of
which in Hungary is 21° C, is scarcely 16° C.
in Dublin, which stands on the same isother-
mal line of 9P ; and the mean winter temper-
ature, which sinks in Buda to — 2°-4 C, in
Dublin (with its mean annual temperature,
lower by 9° C.) is still 4° -3 above the freezing
point of water ; i. e., it is 2° C. higher than in
Milan, Pavia, Padua, and the whole of Lom-
bardy, where the mean annual temperature is
fully 12°-7 C. At Stromness in the Orkneys,
not half a degree further to the south than
Stockholm, the mean winter temperature is 4°
C, higher consequently than that of Paris, and
nearly equal to that of London. Even in the
Faro Islands in 62° N. latitude, the influence
of the westerly winds and of the ocean is such,
that the water of the inland lakes never free-
zes. On the pleasant coasts of Devonshire,
where Salcombe, by reason of its mild climate,
has been called the Montpellier of the North,
the Agave Mexicana has been seen flowering
in the open air, and Oranges, trained as espa-
liers, and scarcely protected for a few weeks
with mats, have borne fruit. There, as well
as at Penzance and Gosport, and Cherbourg
on the NoriAn coast, the mean winter tem-
perature is as high as 5°-5 C, that is to say,
but l°-3 below the temperature of the corre-

[* " From beds of raging fire to starve in ice."

Milton, after Dant\
thongh the English poet )ays the scene in his Hell.— T»,l

THE ATMOSPHERE— CLIMATE.

99

Bponding season in Montpellier and Flor-
ence("^). The relations now indicated show
how important for vegetation, agriculture, the
growth of fruit, and the feeling of climatic com-
fort is the distribution of the same annual mean
temperature over the different seasons of the
year.*

The lines which I have entitled isochimenal
and isotheral (lines of like mean winter and
summer heat) are by no means parallel with
the isothermal lines (lines of like mean annual
heat). If in places where the Myrtle grows
untended, and the ground in winter is never
permanently covered with snow, the tempera-
ture of the summer and autumn is still just suf-
ficient— nay, it might be said, is barely suffi-
cient to bring the apple to perfect ripeness ; if
the vine, when it yields drinkable wine, flies
islands, and almost all sea-boards, even those
with a western exposure ; the cause of this
does not alone reside in the lower summer
temperature of the coasts, which our thermom-
eter in the shade proclaims ; it lies in the hith-
erto so little considered, and yet in other phe-
nomena (such as an explosion of a mixture of
chlorine and hydrogen gas) so important dis-
tinction between direct and diffused light with
a clear or clouded state of the heavens. It is
long since I directed the attention of the ob-
servers of natural phenomena and of botanical
physiologists to these distinctions, as well as
to the unestimated heat locally developed in
the vegetable cell under the influence of direct
Iight(36*).

If we descend in the thermal scale of hus-
bandry of different kinds(^"), beginning with
the hottest climates, where Vanilla, Cacao, the
Banana, Plantain, and Cocoanut Palm are suc-
cessfully cultivated, to the regions in succes-
sion of the Pine-apple, Sugar-cane, Coffee,
Date, Cotton-tree, Citron, Olive, true Chestnut,
and Vine yielding drinkable wine, the careful
geographical consideration of the limits of each
of these species of culture, respect being had
at once to the plain and to the mountain slope,
assures us that other climatic relations than
those connected with the mean annual temper-
ature here come into play. To take the single
instance, of the vine, I remind my reader, that
in order to have palatable wine('*^), not only
must the mean annual temperature exceed 9^°
C. [49°-55 F.], but that the mean winter cold
must not fall quite to the freezing point (0°-5
C, 33°-4 F.), and this must be followed by a
mean summer heat of at least 18° C. [64°-4 F.].
At Bordeaux, in the valley of the Garonne
(North latitude 44° 50'), the temperature of the
year, of the. winter, of the summer, and of the
autumn, are respectively 13°-8; 6°-2 ; 21°-7;
and 14°-4. In the plains of the Baltic, where
wine is grown that is not palatable, though it
is nevertheless consumed, the corresponding
numbers are 8°-6 ; —°7; 17°-6; and 8°-6. If
it seem strange that the great differences which
the cultivation of the vine, favoured or opposed
by climate, exhibits, are not more conspicuous-
ly shown by our thermometrical numbers, this
strangeness will be lessened by the considera-

[* For a great deal of interesting information on temper-
ature the reader is referred to an excellent " Thermomet-
rical Table," by Alfred S. Taylor, published by Willatt, 98
Cheapside. It is a complete Encyclopedia of Thermotics.
— Tk.]

tion, that a thermometer set for observation in
the shade, and as effectually as possible pro-
tected from the effects of direct insolation and
nocturnal radiation, does not by any means
give the true superficial temperature for every
division of the year, under periodical variations
of the heat of the ground, exposed to the whole
amount of insolation [and of radiation].

In the same way as the milder, more equa-
ble climate of the peninsula of Brittany stands
related to the climate of the rest of the com-
pact continent of France, colder in winter, hot-
ter in summer, so to a certain extent does the
climate of Europe stand related to that of the
general continent of Asia, to which Europe
forms, in fact, a kind of western peninsula.
Europe owes its milder climate : to the geo-
graphical position of Africa, which in its vast
extent, favouring the ascending current of air,
presents a solid radiating surface within the
tropics, whilst southward from Asia the equa-
torial region is mostly oceanic ; to its parti-
tions and vicinity to the sea — its forming the
western boundary of the northern part of the
Old World ; to the existence of a sea free from
ice, where it extends towards the north. Eu-
rope from this would become colder were Af-
rica to be overflowed by the sea and to disap-
pear(^^^) ; were the Mythical Atlantis to arise
and connect Europe with North America ;
were the gulf-stream to cease from flowing
and pouring its tepid current into the northern
sea, or were another continent, raised by vol-
canic forces, to intervene between the Scandi-
navian peninsula and Spitzbergen. If we see
the mean annual temperature of Europe sink-
ing as we proceed along the same parallel of
latitude from the shores of the Atlantic, from
France, through Germany, Poland, and Russia,
towards the Ural Mountains, from west to east,
therefore, the principal cause of the phenome-
non is to be sought for in the progressively less
and less subdivided or more compact form of
the land as the longitude increases, in the in-
creasing remoteness of the tempering ocean,
as iti the feebler influence of the west wind.
Beyond the Ural chain the west becomes the
chilling land-wind, for then it is blowing over
extensive tracts of country covered with ice
and snow. The intense cold of Western Sibe-
ria is greatly connected with such relations of
configuration in the land and of currents of
air(^^'*), nowise, as Hippocrates and Trogus
Pompeius presumed, and as distinguished trav-
ellers in the 18th century have gone on fancy-
ing, with great elevation of the country above
the level of the sea.

If we pass on from the consideration of di-
versities of temperature in the plains, to ine-
qualities in the polyhedral configuration of the
surface of our planet, we contemplate the
mountains either according to their influence
on the climate of the neighbouring low lands,
or according to the influences which they ex-
ert, in consequence of hypsometrical relations,
upon their own summits, frequently spread out
into lofty plateaus or table-lands. The group-
ing of mountains into chains divides the sur-
face of the earth into different basins, some-
times into narrow circular valleys surrounded
by lofly walls — circus-like cauldrons, which (as
in Greece and a portion of Asia Minor) give in-

100

THE ATMOSPHERE.

dividual local characters to the climate in re-
spect of warmth, dampness, frequency of winds
and storms, and transparency of atmosphere.
These circumstances hare from time immemo-
rial exerted a powerful influence upon the na-
ture of the productions of the soil, and on the
manners, forms of government, and likings and
dislikings of neighbouring races for one anoth-
er. The character of the geographical individ-
uality reaches its maximum, as it were, where
the diversities in the configuration of the sur-
face, both in the vertical and the horizontal di-
rection, in the relief and the partitioning of con-
tinents, are the greatest possible. With such
relations of the soil are contrasted the steppes
of Northern Asia, the grassy plains (Prairies,
Savannas, Llanos, and Pampas) of the New
Continent, the heaths or moors of Europe, and
the sandy and rocky deserts of Africa.

The law of the decrement of temperature ac-
cording to the height above the sea under dif-
ferent parallels of latitude, is one of the most
important particulars in connection with the
knowledge of meteorological processes, with
the geographical distribution of plants, the theo-
ry of terrestrial refraction, and the various hy-
potheses which bear upon the determination of
the height of the atmosphere. In the course
of the numerous mountain expeditions I have
undertaken, both within and without the trop-
ics, the determination of this law has always
been one of the principal objects of my obser-
vations and experiments(^").

Since the true relations of thermal distribu-
tion over the surface of the earth, i. e., the in-
flections of the isothermal and isotheral lines,
and the unequal distances of these from each
other in the several systems of eastern and
western temperature of Asia, mid-Europe, and
North America, have been studied and made
more generally known, we must not any long-
er inquire, even in a general way, what frac-
tional part of the mean annual or summer tem-
perature corresponds to a change of one de-
gree of. geographical latitude 1 In each system
of isothermal lines of like curvature there pre-
vails an intimate and necessary connection be-
tween three elements : the decrease of tem-
perature in the perpendicular direction from
below upwards ; the difference of temperature
in changing the place of observation by 1° of
latitude ; the equality of the mean tempera-
ture of a mountain station, and the polar dis-
tance of a point laid down on the level of the
sea.

In the East American system, the mean an-
nual temperature changes from the coasts of
Labrador to Boston for every degree of lati-
tude by 0°-88 C. ; from Boston to Charleston
by 0°-95 C. ; from Charleston to the tropic of
Cancer in Cuba onwards, the change, however,
becomes less — there it is only 0°-66 C. With-
in the tropics the change is still smaller, the va-
riation from Havanna to Cumana, correspond-
ing to a degree of latitude, being no more than
0° 20 C.

It is quite different in the system of iso-
therms of mid-Europe. Between the parallels
of 38° and 71 ° I find the decrease of temperature
to coincide very accurately with half a degree
(0°-5 C.) for each degree of latitude. But, as
in this country, the fall in temperature is 1° C.

for every 480, or 523 feet of perpendicular rise,
it follows that here a rise of from 240 to 262
feet above the level of the sea corresponds, in
respect of temperature, to one degree of lati-
tude. The mean annual temperature of the
Convent on Mount St. Bernard, 7,668 feet
above the sea-level, in latitude 46° 50', would
thus be met with again in the plain, in latitude
75° 50'.

In that part of the chain of the Andes which
lies within the tropics, my observations, which
have been carried out to an elevation of 18,000
feet, indicate a fall of 1° C. for 96 toises, or 576
feet ; my friend Boussingault, thirty years later,
found 90 toises, or 540 feet, as the mean corre-
sponding to the same fall. On comparing the pla-
ces which stand among the Cordilleras at equal
heights above the sea, whether on the slopes
themselves, or on the extensive plateaus which
they form, I found an increase of from l°-6 to
2°-3 C. in mean annual temperature of the lat-
ter over the former. Without the cooling ef-
fects of nocturnal radiation, the difference
would be still greater. As the climates are
there stratified, as it were, superposed in lay-
ers from the Cacao groves of the lowlands up
to the line of perpetual snow, and as the tem-
perature in the tropical zone varies but very
slightly in the course of the whole year, a tol-
erably fair idea is formed of the relations in
respect of temperature to which the inhabi-
tants of the great cities of the Andes are ex-
posed, when these relations are compared with
the temperature of particular months in the
plains of France and Italy. Whilst the tem-
perature of the day on the wooded banks of the
Orinoco is such that it exceeds, by 4° C, that
of the month of August at Palermo, we find
when we have ascended the mountains to Po-
payan (911 toises), that we are in the tem-
perature of the three summer months at Mar-
seilles ; in Quito, again (1493 toises), the tem-
perature is that of the end of the month of
May at Paris, and when we have attained the
Paramos or mountain wilds, overgrown with
dwarf Alpine plants, still bearing large flowers
(1800 toises), we meet with the temperature of
the beginning of the month of April at Paris.

The acute Peter Martyr de Anghiera, one of JSt
the friends of Christopher Columbus, was the |H
first who perceived (in the expedition of Rod-
rigo Enrique Colmenares, Oct. 1510), that the
snow-line always rises higher the nearer the
equator is approached. I find these words in
the beautiful work,. De Rebus Oceanicis(2'"') :
" The River Gaira comes from a mountain (in
the Sierra Nevada de Santa Marta), which,
from the reports of the companions of Colme-
nares, is higher than any mountain yet discov-
ered. It must undoubtedly be so, if, in a zone
which is at most 10° from the equinoctial line,
it retains its covering of snow continually."
The inferior limit of the eternal snow in a given
latitude is the summer limit of the snow-line ;
that is, the maximum height to which the
snow-line recedes in the course of the entire
year. From this summer limit of the snow-
line, three other phenomena must be distin-
guished : Annual fluctuations of the snow-line ;
occasional or sporadic falls of snow ; and gla-
ciers, which appear to be peculiar to the tem-
perate and frigid zones, on which Saussure's

THE ATMOSPHERE.

101

fmraortal work on the Alps, and in later years
the labours of Venetz, of Charpentier, and of
Agassiz, endowed with perseverance that set
rtanger at naught, have thrown much interest-
ing and new light.

We know only the inferior, not the superior,
boundary of the eternal snow ; for the mount-
ains of the earth do not rise into the ethereal
or Olympic empyrean, into the thin dry strata
of the atmosphere, which we may presume
with Bouguer no longer contain any vesicular
vapour turned into crystals of ice, and thus
made visible. The lower snow-limit, howev-
er, is not merely a function of the geographical
latitude, or the mean annual temperature ; the
tropics, even the equator itself, is not the sit-
uation, as was long believed and taught, where
the snow-limit attains its highest elevation
above the level of the sea. The phenomenon
which we here advert to is, in fact, an ex-
tremely complicated one, and depends general-
ly on various relations of temperature, moist-
ure, and mountain configuration. If these re-
lations themselves be subjected to a more spe-
cial analysis, as a great number of new meas-
urements permit us to do(^"), we discover as
coefficient causes determining the snow-line :
Differences in temperature of the different I
seasons of the year ; direction of the prevail- I
ing winds, and their contact with the sea and !
land ; the degree of dryness or moistness of
the upper strata of the atmosphere ; the abso-
lute magnitude or thickness of the deposited
and accumulated snow ; the relation of the
snovi^y summit to the total height of the mount-
ain ; the relative position of the particular
mountain considered in the chain ; the steep-
ness of the declivities ; the vicinity of other
mountains likewise capped with perpetual
snow ; the extent, lay, and height of the plain
or level from which the snowy mountain rises
isolated, or as one in a group or chain, and
which may be a sea-coast, or the interior
of a continent, covered with wood, or with a
thick short turf, which may be sandy, barren,
and strewn with naked rocks, or a wet mossy
bottom.

While the snow-line in South America reach- i
es a height under the equator which equals j
that of the summit of Mont Blanc, and in the i
high lands of Mexico, near the northern tropic,
in 19° North latitude, according to recent
measurements, descends from that by a quan-
tity equal to about 960 feet, it rises, according
to Pentland, in the southern tropical zone (lat. j
up to 18^ south), and in the western or Chil- '
ian Andes, not in the eastern chain, to more
than 2500 feet higher than it is under the equa-
tor, on Chimborazo, Cotopaxi, and Antisana,
not far from Quito. Dr. Gillies states, indeed,
that much farther to the south, namely, on the
declivity of the volcanic mountain Penguenes
(33° S. lat.), he found the snow-line at an ele-
vation between 2270 and 2350 toises above the
level of the sea. The evaporation of the snow,
in consequence of the radiation into an atmo-
sphere which is excessively dry in summer,
into skies which are scarcely obscured by a
cloud, is so rapid, that the volcano of Aconca-
gua, to the north-east of Valparaiso (lat. 32^°
south), which was found by the Expedition of
the Beagle to be more than 1400 feet higher

than Chimborazo, was once seen without
snow(3").

In almost the same parallel of North lati-
tude (30J°to 31°), the snow-limit of the south-
ern slopes of the Himalaya is found nearly at
the elevation which various combinations and
comparisons might lead us to expect, viz.,
12,180 feet; on the northern slopes, however,
under the influence of the lofty table-land of
Thibet, the mean height of which appears to
be 10,800 feet, the snow-limit is only met with
at an elevation of 15,600 feet. This phenom-
enon, which has often been the subject of dis-
cussion both in Europe and in India, on the
cause of which I have myself made known my
views in several papers(3^^), possesses more
than a merely physical interest ; it has had an
important influence upon the state of numerous
tribes of mankind. Meteorological processes
fit or unfit extensive districts of a continent for
agriculture or pasturage.

As with the temperature the quantity of va-
pour contained in the atmosphere increases,
this, which is so important an element for the
whole of the organic creation, varies with the
hour of the day, the season of the year, the de-
gree of latitude, and the height above the level
of the sea. The recent experience so general-
ly obtained through the use of August's Psy-
chrometer, according to the ideas of Dalton
and Daniell, for the determination of the rela-
tive moistness of the air by means of the dif-
ference between the dew-point and the tem-
perature of the air,* has considerably increased
the extent of our knowledge of the hygromet-
rical relations of the surface of the earth. Tem-
perature, atmospheric pressure, and quarter of
the wind, all stand in most intimate connec-
tion with the vivifying moisture of the air.
This vivification, however, is not so much a
consequence of the quantity of vapour held dis-
solved under different latitudes, as of the man-
ner and frequency of its precipitation in the
shape of dew, fog, rain, or snow, which moist-
ens the ground. From the deduction of the
gyratory law of winds by Dove, and the views
of this distinguished philosopher(^^*), it appears
that in our northern zone "the elasticity of va-
pour is greatest with south-west, least with
north-east winds. On the west side of the
wind-card it diminishes, and on the contrary it
rises on the east side. On the west side, viz.,
the colder, heavier, drier current, forces back
the warmer, lighter, much moister air ; whilst
on the east side the former is overcome by the
latter. The south-west current is the pene-
trating equatorial stream ; the north-east the
sole prevaihng polar current."

The beauty and fresh verdure of many trees
which grow in countries within the tropics,
where for five, six, or seven months together
there is never a cloud to be seen on the face
of the heavens, where no visible dew or rain
ever falls, inform us that the appendages of the
stem or the leaves have the power, in virtue
of a peculiar vital process, which perhaps is
not one merely producing cold by radiation, of

[* Now very conveniently obtained by the different read-
ings of two thermometers, as like each other as possible,
one of which has its balb dry, the other its bulb wet. The
instrument is commonly sold under the name of Mason's
Hy^ometer in England.— Tb.]

102

THE ATMOSPHERE.

withdrawing water from the atmosphere. With
the parched levels of Cumana, Coro, and Cea-
ra, in North Brazil, the deluges of rain which
fall in other districts of tropical countries con-
trasts strongly : for example, in Havana, where
observations carried on for six years by Ramon
de la Sarga show the mean annual fall of rain
to amount to 102 Parisian inches — four or five
times as much as it is in Paris or Geneva(^").
On the slopes of the Andes, the quantity of
rain that falls, like the temperature, diminishes
with the height(3"). It was found by my com-
panion in my South American journey, M. Cal-
das, of Santa Fe de Bogota, not to exceed 37
inches at a height of 8200 feet, which is but
little more than the quantity that falls on some
of the west coasts of Europe. At Quito, when
the temperature was from 12° to 13° C, Bous-
singault sometimes saw Saussure's hygrome-
ter recede to 26° ; and in his great aerostatic
ascent Gay Lussac saw the same instrument
at 25° -3, his elevation at the time being 6600
feet, and the temperature of the air 4° -6 C.
The greatest degree of dryness yet observed in
a low country was seen by Gustavus Rose,
Ehrenberg, and myself, between the valleys of
the Irtisch and Obi, in Northern Asia. In the
Platowskaja Steppe, after the south-west wind
had been long blowing from the interior of the
continent, the temperature of the air being
23°-7 C, we found the dew-point 4°-3 below
the freezing-point. The air only contained JA^
of watery vapour(3"). Several able observers,
Kaemtz, Bravais, and Martins, have of late
years called in question the great degree of
dryness of the mountain air, which seemed to
follow from Saussure's observations among the
Alps, and my own among the heights of the
Cordilleras. The relative moistness of the air
in Zurich was contrasted with that of the air
of the Faulhorn, a mountain which indeed could
only be called high in Europe(^'^). The moist-
ure with which the peculiar species of large-
flowered, myrtle-leaved Alpine shrubs are al-
most perpetually bedewed in the region of the
Paramos of the tropical Andes, betvi^een 11,000
and 12,000 feet above the sea level, and not far
from the line where snow begins to fall, does
not, however, necessarily imply a great abso-
lute moistness of the air in this region ; like
the frequent fogs in the beautiful plateau of
Bogota, it only proclaims the frequency of pre-
cipitations. Banks of fog at these heights form
and disappear several times in the course of
an hour when the air is calm ; such rapid chan-
ges characterize the lofty plateaus and paramos
of the Andes.

The ELECTRICITY OP THE ATMOSPHERE, Wheth-
er considered in the lower regions or in the
cloudy canopy aloft, viewed problematically in
its silent periodical diurnal progression, or in
the brilliant and noisy explosions of the thun-
der-storm, stands in manifold relationship with
all the phenomena of thermal distribution, of
atmospheric pressure and its disturbances, of
hydrometeors, and apparently also of the mag-
netism of the outer crust of the earth. It ex-
erts a most powerful influence upon the whole
of the animal and vegetable world, and this not
merely through the meteorological processes,
precipitations of watery vapour, of acids, or of
ammoniacal compounds, which it occasions,

but also immediately as the electrical force,
that force which excites the nerves and occa-
sions or assists the circulation of the juices.
This is not the place to renew the contest in
regard to the source of the electricity of the
serene sky, which has at one time been ascri
bed to the evaporation of impure fluids, i. e. flu-
ids loaded with earths and sdlts(3"), at another
to the growth of vegetables(3'*°), or other chem-
ical decompositions proceeding on the surface
of the earth, to the unequal distribution of heat
in the different strata of the atmosphere(3*^),
finally, according to Peltier's able inquiries(^^'),
to the influence of a constantly negative charge
of the globe. Limited to the results which
electrometrical observations, particularly those
which the clever arrangement of an electro-
magnetical apparatus, first proposed by Colla-
don, have given. Physical Cosmography ought
to indicate the unquestionable increase of the
general positive aerial electricity with the height
of the station and freedom from surrounding
trees(^"^), its daily ebb and flow (according to
Clarke's Dublin experiments, in more intricate
periods than Saussure and I had detected), and
its differences according to season, distance
from the equator, and the continental or oceanic
nature of the surface.

If the electrical equilibrium, on the whole, be
less disturbed where the atmosphere is resting
on the sea than on the land, it is the more re-
markable to observe how small clusters of isl-
ands surrounded by an extensive ocean act
upon the state of the atmosphere and give oc-
casion to thunder-storms. In fogs, and at the
beginning of falls of snow, I have in the course
of a long series of observations seen the pre-
vious permanent vitreous, change suddenly into
the resinous electricity, and these alternate re-
peatedly, as well in the plains of the frigid zone
as under the tropics in the Paramos or Alpine
wildernesses of the Cordilleras between 10,000
and 12,000 feet high. The alternate transition
was in all respects similar to that which the
electrometer had shown shortly before during
the continuance of a thunder-storm(^**). When
the vesicles of vapour have become aggregated
into clouds with determinate outlines, the elec-
trical tension of the outer layer or surface(2**)
upon which the electricity of the insulated ve-
sicular vapour overflows, increases with the
measure of the condensation. Slate-gray col-
oured clouds, according to Peltier's Paris ex-
periments, have resinous, white, rose, and
orange-coloured clouds, have vitreous electri-
city. Thunder clouds not only involve the
highest summits of the Andes, (I have myself
observed the vitrifying effects of lightning on
one of the rocky crags which rise from the cra-
ter of the Volcano of Toluca, 14,300 feet high),
but storm clouds have been measured, which
were floating over low lands in the temperate
zone, at a vertical height of 25,000 feetC^").
Occasionally, however, the thundering and
lightning stratum of cloud descends to an alti-
tude of five, and even of three thousand feet
from the ground.

According to Arago's experiments, the most
comprehensive we yet possess upon this diffi-
cult portion of meteorology, there are dischar-
ges of lightning of three kinds : zig-zag or fork-
ed lightnings, sharply defined on their edges ;

ORGANIC LIFE.

lightnings that illuminate whole clouds, which
seem to open up at once ; lightning in the form
of fire-ballsC^"'). If the two first of these
scarcely last for the -j-^i^ of a second, the glob-
ular kind of lightning, on the contrary, moves
much more slowly, and continues visible for
several seconds. Occasionally — and late ob-
servations confirm the description of the phe-
nomenon already given by Nicholson and Bec-
caria — single clouds show themselves high
above the horizon, which, without audible thun-
der, without any appearance of a storm, con-
tinue steadily luminous for a long time both in
the interior and around the edges ; hail-stones,
drops of rain, and flakes of snow, have also
been observed, which were luminous as they
fell, without any precursory thunder-storm.

In the geographical distribution of storms,
the coasts of Peru, in which it never thunders
or lightens, present the most remarkable con-
trast with all the rest of the tropical zones be-
sides, in which at certain seasons of the year,
four or five hours after the culmination of the
sun, thunder-storms occur almost every day.
From the concurring testimony of northern nav-
igators — Scoresby, Parry, Ross, Franklin—
which has been collected by Arago, it is im-
possible to doubt that in high northern latitudes,
such as the parallels from 70° to 75°, electrical
explosions are extremely rareC^^**).

The meteorological portion of our Delinea-
tion of Nature, which we here conclude, shows
that all the processes— absorption of light, ev-
olution of heat, alteration of elasticity, hygro-
metrical state and electrical tension, which the
immeasurable atmospheric ocean presents, are
so intimately connected, that each individual
meteorological process is simultaneously modi-
fied by any one, or by all the others. These
varied disturbances, which involuntarily re-
mind us of those that the nearer and particu-
larly the smaller of the heavenly bodies, the
satellites, comets, and shooting stars, experi-
ence in their course through space, render the
interpretation of the complex meteorological
processes difficult ; they circumscribe, and, for
the most part, make impossible, the prediction
of atmospherical changes, which for horticul-
ture and agriculture, for navigation and the en-
joyment and pleasure of existence, would be
so important. Those who place the value of
meteorology not in a knowledge of the subject
itself, but in such problematical prognostica-
tions, are penetrated with the belief that this
portion of natural science, on account of which
so many journeys have been made into remote
mountainous countries of the globe, cannot
boast of any advance for centuries. The con-
fidence which they refuse to natural philoso-
phers, they yield to the changes of the moon,
and to certain famous days in the calendar.

" Great departures from the usual distribu-
tion of mean temperature seldom occur locally ;
they are, for the most part, relatively shared
in by extensive districts of country. The
amount of departure is a maximum at one par-
ticular spot, from which it diminishes to the
confines around. If these confines be exceed-
ed, great variations in the opposite sense are
forthwith discovered. Like constitutions of
the weather are more frequently observed from

South to North than from West to East. The
maximum cold of the end of 1829, (when I con-
cluded my Siberian travels), occurred at Berlin,
whilst North America enjoyed an unusual mild-
ness of season. It is an entirely arbitrary as-
sumption to suppose that a hot summer follows
a cold winter, or that a mild winter succeeds a
cool summer'X^^'). The states of the weather in
neighbouring lands — two corn and wine-grow-
ing countries, for example, often so varied and
so opposite, produce the most beneficial effects
in equalizing the prices of agricultural produce
rn each. It has been well observed, that the
barometer alone informs us of what is going on
in respect of alterations in the pressure of the
whole of the strata of air above the place of
observation, even to the extreme limits of our
atmosphere, whilst the thermometer and hy-
grometer only report upon the local tempera-
ture and moistness of the lower stratum in con-
tact with the surface. We only conclude as to
the thermometrical and hygroscopical modifica-
tions of the upper strata, where immediate ob-
servations made on mountains or in aerostatic
journeys are wanting, from hypothetical com-
binations, so that the barometer may likewise
come to serve both as a thermometer and hy-
grometer. Important changes in the state of
the weather are not owing to any merely local
cause at the place of observation itself; they
are usually consequences of a condition which
has begun, through perturbation in the equilibri-
um of the currents of air, at a vast distance,
and, for the major part, not at the surface of
the earth, but in the highest regions : bringing
hither cold or warm, dry or moist air, impair-
ing or increasing the transparency of the at-
mosphere, changing the piled masses of cumu-
lus-clouds into the light and feathery cirrus.
Inaccessibility of phenomena thus allying it-
self to multiplicity and complexity of perturba-
tions, it has always appeared to me, that me-
teorology must seek her welfare and her roots
in the torrid zone ; in that favoured region
where the same winds always blow, where the
ebb and flow of the atmospheric pressure, the
course of hydrometeors, and the occurrence of
electrical explosions, are periodically and reg-
ularly recurrent.

Having now passed through the entire circuit
of the inorganic life of the earth, and delinea-
ted our planet with a few leading touches, in
its configuration, its internal heat, its electro-
magnetical charge, its luminous processes at
either pole, and its internal or volcanic reac-
tion upon the solid and variously compounded
crusts ; having, finally, considered the phenom-
ena of its double outer covering, the ocean and
the atmosphere, our Picture of Nature, accord-
ing to the older ideas of Physical Geography,
might be held as finished. But when the phil-
osophic view essays to reach a hig:her point,
the delineation would seem to want its attract-
ive features, did it not at the same time pre-
sent the sphere of Organic Life in the numer-
ous grades of its typical developments. The
idea of animation is so closely connected with
the idea of the existence of the impelling, cease-
lessly active, decompounding, compounding,
and fashioning natural forces, which inhere in
the terrestrial ball, that in the popular Mythus

4|p4 ORGANIC LIFE.

of the nations of antiquity, the production of
plants and animals was always ascribed to these
forces ; the state of the surface of our planet,
when it was unoccupied by life, was even re-
ferred to the chaotic pmneval ages of the con-
flicting elements. To the empirical domain of
objective sensuous consideration, to the delin-
eation of That which has become, or of the ac-
tual state and condition of our planet, the mys-
terious and unresolved problem of Things be-
coming does not rightfully belong.

Our description of the world, abiding soberly
by reality, remains a stranger, not from timid-
ity, but from the nature of the subject and its
limits, to the obscure history of the beginning
of organized things(^"') ; the word history being
here taken in its most usual acceptation. But
in our account of the actual Universe, we may
direct attention to the fact, that in the inorgan-
ic crust of the earth, the same elementary sub-
stances are present which enter into and com-
pose the organic frames of plants and animals.
We may say, that the same powers prevail in
these as in those, which combine and separate
bodies, which give consistency and fluidity in
the organic tissues : but, subjected to condi-
tions which, not yet fathomed, have been
systematically grouped according to analogies
more or less happily imagined, under the very
indefinite titles of effects of the vital force. It
is, therefore, felt as a want, in the frame of
mind which leads us to look on nature with a
contemplative eye, that we pursue the physical
phenomena which present themselves to us on
earth to their very farthest limits, to the evo-
ultion of vegetable forms, and the discovery
of that which in the organisms of animals is
endowed with self-motive force. In this way
does the geographical distribution of things or-
ganically-animated, i. e., plants and animals,
connect itself with the delineation of the inor-
ganic natural phenomena of the body of the
globe.

Without pretending in this place to discuss
the difficult question of " the self-motive" in
animals, i. e., the difference between animal
and vegetable life, we must first direct atten-
tion to the circumstance that, were we endow-
ed by nature with a microscopic eye, and were
the integuments of plants completely transpa-
rent, the world of vegetation would not meet
us with that aspect of immobility and repose
in which it now presents itself to our senses.
The interiors of the cellular structures of vege-
tables are ceaselessly animated by the most di-
versified currents, rotatory, rising and falling,
dividing and ramifying, or altering their direc-
tion— as is made manifest by the movement of
the granular sap-corpuscles in the leaves of
several water-plants (Najades Characeae, Hy-
drocharideae), and in the hairs of phaneroga-
mous land-plants ; there is at the same time
seen a confused, molecular movement, first ob-
served by the distinguished botanist, Robert
Brown, but which also occurs among finely-di-
vided particles of matter of all kinds, the phe-
nomenon not taking place only within organic
cells ; the circular movement of the globules
of the cambium, in a system of special vessels
(cyclosis) ; lastly, the singular articulated fili-
form vessels of the anthers of the Chara and
the reproductive organs of the liverworts and

sea-weeds which have the faculty of uncoiling
themselves, and in which Meyen, snatched too
soon away from science, believed that he rec-
ognized the analogues of the spermatozoa of
the animal creation. If to the multifarious ex-
citements and movements we add those that
belong to endosmose and the processes of nu-
trition and growth, and farther to the penetra-
tion [and exhalation] of air, we have a picture
of the forces which, almost unknown to us, are
active in the silent life of the vegetable world.

Since I first portrayed the universal life of
the surface of the earth, and the distribution
of organic forms, both in the line of the height
and of the depth, in my " Views of Nature,"
our knowledge in this direction also has been
surprisingly increased by Ehrenberg's brilliant
discoveries, "on the demeanor of minute life
in the ocean as well as in the ice of the polar
lands," discoveries made not by the way of in-
duction, but by that of simple accurate observa-
tion. The sphere of vitality, we might almost
say the horizon of life, has extended itself be-
fore our eyes. " There is not only an invisibly
small, or microscopical, incessantly active life
in the neighbourhood of both poles, where lar-
ger organisms are no longer produced ; but the
microscopical forms of life of the South Polar
Sea, collected in the Antarctic Voyage of Sir
James Ross, comprise a wonderful variety of en-
tirely new and often extremely beautiful forms.
Even in the remains of the liquefied round-
ed masses of ice that were picked up swim-
ming about under the latitude of 78° 10", more
than fifty species of silicious-shelled polygas-
trica, coscinodisca, with their green ovaries,
and consequently living and successfully strug-
gling with the extreme of severe cold, were
discovered. In the bay of the Erebus, in from
1242 to 1620 feet of water, sixty-eight silicious-
shelled polygastrica and phytolitharia, and with
them only a single calcareous-shelled polytha-
lamium, were drawn up by means of the lead.

The oceanic microscopic forms have hitherto
been in vastly preponderating proportion of the
silicious-shelled kinds, although sihca does not
appear among the constituents of sea-water dis-
covered by analysis, and the earth can only be
well conceived as mixed with or suspended in
the waters. The ocean, however, is not only
in particular spots, and in arms and bays, or
near the shore, thickly peopled with invisible,
i. e., by the unassisted eye, unseen living at-
oms ; it may be assumed, from the samples of
water drawn to the south of the Cape of Good
Hope, under 57° S. latitude, as well as from
the middle of the Atlantic, under the tropics,
by Schayer, in his return from Van Diemen's
Land, that in its ordinary state, without shown
ing any particular colour, without being filled
with floating fragments of the silicious-shelled
filaments of the genus Chaetoceros, which so
much resemble the Oscillatoria of our fresh
waters, but when perfectly transparent to the
naked eye, the ocean still contains numerous
independent microscopical organisms. Sever-
al polygastrica from Cockburn Island, mixed
with the excrements of Penguins and sand, ap-
pear to be spread over the whole earth ; oth-
ers, again, are common to either pole(^").

From this (and all the more recent observa
tions confirm the view) it appears that in the

ORGANIC LIFE.

105

eternal night of the depths of ocean, animal life
especially prevails, whilst upon continents, ve-
getable life, which requires the periodic stimu-
lus of the ^un's rays, is the more extensively
diffused. Considered with reference to mass,
the vegetable far exceeds the animal world on
the face of the globe. What is the number of
great cetaceans and pachydermatous tribes, in
comparison with the bulk of the thick-set trunks
of lofty trees, from eight to twelve feet in di-
ameter, that grow in the forests of the tropical
zone of South America, between the Orinoco,
the Amazon's River, and the Rio de Madeira !
Even allowing the character of the several
countries of the earth to depend on the aspect
of external phenomena at large ; if the outline
of mountains, the physiognomy of plants ana
animals, the blue of the sky, the contour of the
clouds, and the transparency of the atmosphere
produce the general impression, still it is not
to be denied that the principal element in this
impression is the vegetable covering of the sur
face. The animal kingdom wants mass, and
the motions of individuals withdraw them fre-
quently from our sight. The vegetable world
works upon our imagination by the mere force
of quantity ; its mass indicates its age ; and in
vegetables alone are age and the expression of
inherent power of renovation associated(^'2).
In the animal kingdom — and this consideration
is also the result of Ehrenberg's discoveries —
it is precisely the life that we are wont to des-
ignate as the smallest in point of room, which
by its subdivision and rapid increase(^") pre-
sents the most remarkable relations in respect
of mass. The smallest of the Infusoria, the
Monadae, only obtain a diameter of g^^^^th of a
line, yet do these silicious-shelled organisms,
in moist countries, compose, by their accumu-
lation, subterraneous strata several fathoms in
thickness.

The impression of an all-animated nature, so
exciting and so salutary *o feeling man, belongs
to every zone ; but it is mo.st powerfully pro-
duced towards the equator, in the peculiar zone
of the palms, the bamboos, and the arborescent
ferns — in regions where, from sea shores cov-
ered with molluscs and corals, the ground rises
in stages to the line of eternal snow, and the
relations of plants and animals, in respect of
local position, embrace almost every height and
every depth. Organic forms even descend into
the interior of the earth, and occur not merely
in places where, through the operations of the
miner, great excavations have been made ; in
natural cavities, also, which have been opened
for the first time by blasting, and to which me-
teoric water alone could have penetrated through
fissures, I have found the snowy stalactitic
walls covered with the delicate reticulations
of anUsnea. Podurellae penetrate into the icy
circles of the glaciers of Monte Rosa, of the
Grindelwald, and the Upper Aar. Chioncea
arenoides, described by Dalman, and the mi-
croscopic Discerea nivalis, or Protococcus, as
it used to be called, lives among the snows of
the polar regions as well as of our loftier mount-
ains. The red colour of old snow was known
to Aristotle, and was probably observed by him
among the mountains of Macedonia(39*). Whilst
upon the lofty summits of the Swiss Alps, Le-
cideas, Parmelias, and Umbilicarias alone, and
O

sparingly, tint the rocks left bare of snow, in the
elevated regions of the tropical Andes, at the
height of 14,000 and 14,400 feet above the lev-
el of the sea, single specimens of beautiful
phanerogamous plants are still encountered —
the tomentose Calcitium rufescens, Sida Pi-
chinchensis, and Saxifraga Boussingaulti. Hot
springs contain small insects — Hydroporua
thermalis, Galionellae, Oscillatoria, and Confer-
vas ; they even irrigate the roots of phaneroga-
mous plants. As water, earth, and air are peo-
pled by animated beings at the most dissimilar
temperatures, so also is the interior of the most
dissimilar parts in the bodies of animals inhab-
ited. Animated organisms have been found in
the blood of the frog, salmon, &,c. According
to Nordmann, the whole of the fluids of the
fish's eye are often filled with a suctorial worm
<Diplostomum) ; and in the gills of the brasse
lives that extraordinary double animal, denomi-
nated by the naturalist just mentioned the Di-
plozoon paradoxum ; a creature consisting, as it
seems, of two perfect animals, grown cross-
wise together, having two heads and two cau-
dal extremities.

Granting the existence of meteoric infusoria,
as they have been called, to be more than doubt-
ful, still the possibility must not be denied, that
as the pollen of the pine-tree has fallen year
after year from the air, so may minute infuso-
ry animalcules be passively raised with the wa-
tery vapour, and floated for a season in the at-
i mosphere(^"). This circumstance deserves to
be taken into serious consideration, in connec-
tion with the old dispute in regard to sponta-
neous generation(^^^), (generatio spontanea) ;
all the more, since Ehrenberg, as already ob-
served above, has discovered in the kind of
dust-rain which navigators frequently encoun-
ter in the neighbourhood of the Cape de Verd
Islands, at a distance of 380 sea miles from the
coast of Africa, the remains of eighteen spe-
cies of silicious shelled polygastric animalcules.

The exuberance of organisms whose distri-
bution in space is studied in the geography of
plants and animals, is considered either accord-
ing to the diversity and relative number of the
types of formation, according to the configura-
tion of the existing genera and species, or ac-
cording to the number of the individuals which
each particular species presents upon a given
superficial area. Among plants, as among an-
imals, it is an important distinction in their
mode of life, whether they are met with singly
or living in company. The species which I
have designated social plants(^^') cover large
tracts of country with one unvarying growth.
To this class belong many species of sea-weed
in the ocean, Cladoniae and Musci in the waste
levels of Northern Asia, Grasses and tubular
looking Cactuses, Avicennia and Mangrove in
the tropical world, forests of coniferous trees and
birches in the Baltic and Siberian plains(35«).
This kind of geographical distribution of plants,
along with the individual aspect of the species,
their size, the form of their leaves and flowers,
determines in an especial manner the physi-
ognomical character of a country. The shift-
ing image of animal life, so varied and attract-
ive, appealing so immediately to our feelings
of liking or disgust, remains almost wholly for-
eign, or at least is much less powerfully felt, in

106

ORGANIC LIFE.

connexion with the members of the vegetable
kingdom. Agricultural nations increase arti-
ficially the domain of various social plants, and
so increase the aspect of uniformity presented
by nature in several districts of the temperate
and northern zones ; they also root out and de-
stroy various wild-growing plants, and unin-
tentionally propagate others that follow man in
his wanderings. The luxuriant zone of the
tropical world resists more powerfully this for-
cible metamorphosis of creation.

Observers who have perambulated extensive
districts of country in short intervals of time,
who have ascended mountain ranges in which
the climates lie stratified one over another,
must soon have been awakened to the regular
distribution of vegetable forms. They coUect-
ed the raw material of a science whose name
was not yet pronounced. The same zones or
regions of plants which Cardinal Bembo(399), in
the 16th century, when yet a youth, described as
occurring on the slopes of Etna, were found re-
peated on Mount Ararat, by Tournefort, who
acutely compared the Alpine floras with the
floras of plains under different latitudes ; and
who first remarked that the elevation of the
ground above the level of the sea in mountain-
ous districts influences the distribution of plants
in the same way as distance from the pole in
plains. Menzel, in an unedited Flora of Japan,
incidentally used the expression Geography of
Plants. This phrase again recurs in the fan-
tastic but pleasant '' Studies of Nature" of Ber-
nardin de St. Pierre. But the scientific treat-
ment of the subject commenced wiien the dis-
tribution of plants was viewed in close connex
ion with the doctrine of the distribution of heat
over the surface of the earth ; when plants
were arranged into natural orders, and it was
thus made possible to distinguish numerically
the particular forms which increase or diminish
from the equator towards the poles, to per-
ceive, in the different regions of the earth, in
what numerical relationship each family stands
to the whole of the mass of phanerogamous
vegetables which are there indigenous. It is
one of the fortunate events in my life, that at
the time when I was giving my attention al-
most exclusively to botany, my studies should
have been directed to the subject of inquiry
just mentioned, by the spectacle of nature on
the grandest scale, and offering the strongest
contrasts in respect of climate.

The geographical distribution of animal
forms, upon which Buffon first advanced gen-
eral, and, for the major part, very accurate
views, has in recent times had great assist-
ance from the progress of vegetable geography.
The curvatures of the isothermal, and particu-
larly of the isochimenal lines, are displayed in
the limits which certain species of plants, and
of animals that do not roam far towards the
north or towards the tops of snow-covered
mountains, seldom exceed. The Elk, g. g.,
lives in the Peninsula of Scandinavia, almost
ten degrees farther to the north than in the in-
terior of Siberia, where the lines of like win-
ter temperature are so remarkably concave.
Plants wander or migrate in the egg, in the
seed. The seeds of many species are provi-
ded with peculiar organs for far journeys
through the air. Once rooted, they are more

dependent on the soil and the temperature of
the atmosphere which surrounds them. Ani-
mals widen at will the circle of their presence
from the equator towards the pole, and partic-
ularly in regions where the isotheral lines arch
out towards the north, where hot summers suc-
ceed the severest winters : royal tigers, which
do not differ from those of India, roam every
summer in Northern Asia to the latitudes of
Berlin and Hamburg, as Ehrenberg and I have
shown in another place(*''°).

The groups or associations of vegetable spe-
cies which we are accustomed to designate
Flor^ (spheres or domains of vegetation),
appear to me, from what I have seen o^ the
earth, by no means to reveal the prevalence of
individual families to such an extent as au-
thorizes us to establish geographical regions of
the Umbellatae, Solidagineae, Labiatae, or Sci-
tamineae. My particular views differ in this re-
spect fropi those of several of my friends among
the most distinguished botanists of Germany.
The character of the Floras in the high lands
of Mexico, New Granada, Quito, European
Russia, and Northern Asia, consists, as I be-
lieve, not in the relatively larger number of
species which one or two natural families ex-
hibit, but rather in the much more complex re-
lations of the aggregate life of many families,
and the relative numerical value of their spe-
cies. In meadow and steppe districts Gram-
ineaj and Cyperaceaj are the prevailing fami-
lies ; in our northern woods we meet especial-
ly with Coniferse, Cupuliferae, and Betulineae ;
but this prevalence of form is only apparent,
and deceptive by reason of the mass of the So-
cial plants arresting the eye. The north of
Europe, and Siberia in the zone northward
from the Altai, no more deserve the title of a
realm of grasses or cone-bearing trees, than
the endles Llanos between the Orinoco and
the mountain chain of Caraccas or the pine
forests of Mexico. In the associated life of
the vegetable forms which partly replace one
another, in their relative numbers and group-
ing, lies the aggregate impression of richness
and variety, or of poverty and monotony of
vegetable nature.

In this brief consideration of the phenomena
of organized beings, I have ascended from the
simplest cell(*°'), and so, from the first breath
of life, to higher and higher forms. " The ag-
gregation of mucus-granules into a definitely
formed cell-germ, around which a membrane
in form of a vesicle being developed, it is con-
nected into a closed cell," is either effected by
a pre-existing cell, so that cell arises from
cell(*°='), or the evolution of cells is involved
in the obscurity of a chemical process, as in
the case of the torula cerevisiae, or yeast fun-
gus. The most mysterious subject of Incipien-
cy can only be lightly touched upon here. The
geography of organized beings — plants and ani-
mals— treats of the germs already developed,
of their habitats from migrations effected on
purpose or accidentally, of their respective re-
lations, and their aggregate distribution over
the surface of the earth.

The general delineation of nature, which I
here endeavour to present, would remain in-
complete, were I not to yield to the disposition
I feel, with a few touches, to portray the hu-

ORGANIC LIFE.

107

MAN KIND in its physical gradations, in the geo-
graphical distribution of its simultaneously ex-
isting types, in the influence which it derives
from the forces of nature, and on the contrary,
though in a less degree, the influence which it
has exercised on these. Dependent, although
not to the same extent as plants and animals,
on the ground and the meteorological processes
of the atmosphere, more readily escaping from
under the dominion of some of the natural for-
ces through activity of mind, and intelligence
exalted by degrees, as well as through a won-
derful pliability of constitution, which adapts
itself to every climate, the human kind takes
an essential part in the whole vitality of the
earth. Through thesis relations we are brought
into contact with the obscure and much agita-
ted problem of the possibility of common de-
scent in the circle of ideas which the physical
cosmography embraces. The investigation of
this problem, if I may so express myself, shall,
through ennobled and purely human interests,
be made the last aim of my work. The im-
measurable realm of language, in the diverse
organizations of which, the capacities of na-
tions are foreshadowed, as it were, is most in-
timately connected with the subject of alli-
ance of race ; and what even slight diversity
of race is competent to produce, is taught us
by the Hellenic world in the bloom of its men-
tal culture. The most important questions in
the history of the progress of society connect
themselves with ideas of descent, community
of language, and immutability in an original di-
rection of the affective and intellectual nature
of man.

So long as extremes in diversity of colour
and configuration were alone considered, and
the first liveliness of sensible impression was
yielded to, there might have been the disposi-
tion to consider races, not as mere varieties,
but as originally different kinds of men. The
permanency of certain types(*''3) even amidst
the most inimical operation of external, partic-
ularly climatic influences, appeared to favour
such an assumption, short though the time be
through which historical information has come
down to us. But vouching far more strongly,
according to my views, for the unity of the hu-
man race, are the many middle tintsC*"*) in col-
our of skin, and grades in form of skull, which
the rapid spread of geographical knowledge in
recent times has made known to us ; the anal-
ogy of variety in other wild and domesticated
classes of animals, and the sure experience
which has been collected in regard to the lim-
its of fruitful hybrids of different kinds("5).
The greater number of the contrasts which in
former times were believed to have been dis-
covered, have been disposed of by the industri-
ous work of Tiedemann, " On the Brain of the
Negro and the European," and by the anatom-
ical inquiries of Vrolik and of Weber, " On the
Form of the Pelvis." If we embrace the dark-
skinned African nations, on which Prichard's
admirable work* has thrown so much light, in
their universality, and compare them with the
races of the South Indian and West Australian
Archipelagos, with the Papuas and Alfourous

* [Researches into the Physical History of Mankind, 3d
and 4th edit., 4 vols, 8vo, 1841-44. The Natural History
of Man, 1 vol. 8vo, 1843, 2d edit., 1845.— Tr. J

(Haraforans, Endamenans), we see clearly that
black colour of the skin, woolly hair, and negro-
like features are by no means always conjoin-
ed(*°*). So long as but a small portion of the
world was open to the western nations, they
necessarily came to narrow or one-sided con-
clusions. Heat of sun in the tropical world,
and dark colour of skin, seemed inseparable.
"The .Ethiopians," sings the old tragedian^
Theodectes of PhaselisC*"^), " are dyed by the
near sun-god in his course, with a dark and
sooty lustre ; the sun's heat crisps and dries up
their hair." The expeditions of Alexander,
which were so influential in exciting ideas of
the physical cosmography, first fanned the dis-
pute on the uncertain influence of climate upon
races of men.

" The races of animals and plants," says one
of the greatest anatomists of the age, Joannes
Miiller, in his very comprehensive " Physiolo-
gy of Man,"* *' undergo changes during their
spread over the surface of the earth, within the
limits prescribed to species and genera. But
they are propagated organically as types of va-
rieties of species. From the co-operation of
different, as well internal as external condi-
tions, not to be specified in individual instan^
ces, have the present races of animals proceed-
ed, the most remarkable varieties of which are
met with amongst those that are capable of the
widest distribution over the face of the earth.
All the races of men are forms of a single spe-
cies, which are capable of fruitful union and of
propagation ; they are not different species of
one genus ; were they so, their mixed progeny
would prove unfruitful. Whether the various
races of men are descended from several or
from a single primitive man, cannot be decided
from experience"(*'"*).

Geographical Researches into the ancient
seat, the cradle, as it has been called, of the
human race, possess in fact a purely mythical
character. " We know," says William von
Humboldt, in a work yet unpublished, on the
Diversity of Languages and of Nations, " we
know, neither historically, nor by tradition that
can be trusted, of any epoch in which the hu-
man race have not been collected together into
tribes or communities. Whether this condi-
tion was the original one, or first arose at a la-
ter period, cannot be decided historically. Iso-
lated traditions met with in many different pla-
ces on the earth's surface negative the first as-
sumption, and derive the whole of the human
race from a single human pair. The wide dif-
fusion of this belief has sometimes led to its
being assumed as a primitive recollection
among mankind. But this very circumstance
much rather informs us, that nothing tradition-
al, and nothing historical lies at the root of the
persuasion, but merely similarity of the human
faculty of conception which leads to the same
explanation of the same phenomenon ; many
similar myths have very certainly arisen, with-
out historical connection, out of the similarity
of man's poetical and speculative constitution.
These traditions also bear the entire stamp of
human invention in this, that they explain the
phenomenon of the first appearance of the hu-

* [Ably rendered into English, and copiously commented
and illustrated, by Dr. Wm. Baly,2 vols. 8vo, Load., 1843.
— Tb.]

1108

ORGANIC LIFE.

man race (a point which lies beyond the reach
of all experience), in a way that accords with
the experience of the day, and proceed to show
how, in times when the human kind must al-
ready have existed for thousands of years, a
desert island, or a sequestered valley, may
have been peopled. It is in vain, however,
that reflection attempts to dive into this prob-
lem of original production, seeing that man is
so bound up with his kind and with time, that
an individual without contemporaries, and with-
out a past, can by no means be conceived in
human existence. Whether, therefore, in this
question, which can neither be decided by the
way of reasoning nor of experience, this pre-
tended tradition be the historical truth, or the
human kind from its commencement has pos-
sessed the earth in the shape of tribes or com-
munities, can neither be determined by Philol-
ogy out of the elements of its science, nor, as-
suming the decision on other grounds, can it
use the conclusion come to in illustration of its
own propositions."

The distribution of the human kind is no
more than a distribution into varieties, which
have been designated by the somewhat indefi-
nite word races. As in the vegetable kingdom,
and in the natural history of birds and fishes,
the system of grouping into many small fami-
lies is more certain than that into a few divis-
ions, embracing larger masses, so does it ap-
pear to me preferable, in the determination of
races of men, to arrange them into smaller fam-
ilies. The old classification of m'y master, Blu-
menbach, into five races — the Caucasian, the
Mongolian, the American, the Ethiopian, and
the Malayan, may be followed ;. or with Prich-
ard, seven Vaces may be assumed — the Trani'-
an(*°''), the Turanian, the American, the Hot-
tentot and Buschman, the Negro, the Papuan,
and the Alfoarousian ; still is there no typical
rigour, no natural principle of classification, rec-
ognizable in such arrangements. The extremes
in reference to configuration and colour are sep-
arated, without reference to the stocks that
cannot be connected with one or other of these,
and which have at one time been entitled Scyth-
ian, at another Allophylian races. Tranian, in
reference to the European nations, is certainly
a less objectionable name than Caucasian ;
but it may be maintained in a general way,
that geographical designations as derivative
points of races are very indeterminate, when
the country which is chosen to confer the title
on the race, for example, Turan (Maweran-
nahr), has at different epochs been possessed
by most dissimilar races — of Indo-Germanic
and Finnish, but not Mongolian origin("°).

Languages, as mental creations of man, as
closely intertwined with his spiritual develop-
ment, inasmuch as they exhibit national forms,
possess high importance in connection with the
recognizable similarities and dissimilarities of
races. They have this importance, because
community of descent leads into the myste-
rious labyrinth in which the enchainment of
physical (bodily) aptitude with mental power
is exhibited in. an endless variety of forms.
The brilliant advances which philosophical phi-
lology has made in Germany, especially within
the last half century, facilitate inquiries into the
national character of languages, into that which

descent appears to have added to them(*").
As in all other regions of abstract speculation,
however, the danger of being deceived is here
set beside the hope of collecting a rich and as-
sured booty.

Positive ethnographical studies, based upon
solid historical knowledge, warn us that the
greatest caution is necessary in all compari-
sons of nations A^ith the languages which they
have made use of at determinate epochs. Sub-
jugation, living long together, the influence of
a foreign religion, and intermixture of races,
though often effected by a relatively small
number of more powerful and more civilized
intruders, have produced a phenomenon which
has recurred in like measure, in both conti-
nents, viz. : that totally different families of
languages are met with in use by one and the
same race ; that among nations of very differ-
ent descent, idioms of the same original tongue
are encountered. Asiatic conquerors have had
the greatest influence upon such phenomena.

Speech, however, is a portion of the natural
science of mind ; and if the freedom wherewith
the spirit in a state of happy independence
steadily pursues the self-elected course under
totally different physical influences, strives
vigorously to withdraw it from the power of
the earth, still the unfettering is never quite
complete. There ever remains something of
that which belongs to natural aptitude, to de-
scent, to climate, to the bright blue sky, or to
the cloudy atmosphere of the insular world.
And since copiousness and grace in the struc-
ture of a language are unfolded from thought
as from the most delicate blossom of the soul,
so would we not, that in the intimacy of the
bond which unites the two spheres — that of the
physical nature, and that of the intellect and
•feelings — our delineation should be without the
favourable light and colouring which it must
derive from a consideration, here only indica-
ted, it is true, of the relations of hereditary de-
scent to language.

In maintaining the unity of the human kind,
we at the same time repudiate all the unsatis-
factory assumptions of higher and lower races
of men(*^='). There are races of men more
flexible, more highly polished, through mental
culture more ennobled, but none naturally more
noble. All are in equal measure ordained for
liberty ; for liberty which in ruder conditions
of society appertains to the individual, which
in more polished states, in civil life and among
men in the enjoyment of political institutions,
is the right of the community. " If we would
signalize an idea which is conspicuous through-
out the entire current of history, and ever with
a wider import, when any one assures us of
the much-discussed, but still more extensively
misapprehended perfectibility of mankind, it is
the idea of Humanity : the effort to cast down
the barriers which prejudice and one-sided
views of every kind have hostilely raised be-
twixt man and man, and to treat mankind at
large, without reference to religion, to nation,
or to colour, as one great and nearly-related
family — as a whole, that exists for the accom-
plishment of this single end, the free devel-
opment OF INTERNAL POWER. This is thO OX-

treme, the ultimate purpose of the social state,
and at the same time it is the tendency infixed

ORGANIC LIFE.

109

in the nature of man striving after indefinite
extension of his being. He looks upon the
ground, as it spreads out beneath his feet — on
the heavens, as they arch over his head — on
the stars that shed their light upon him, as in-
timately his own, as given to him for contem-
plation and for reality. The very child longs
to get beyond the hills, the lakes that bound
his narrow home ; and then, plant-like, he longs
to returri ; for it is a touching and a beautiful
element in the nature of man, that all his de-
sires for things agreeable and for things lost,
still approve him exclusively attached to the
moment : firmly rooted in the inmost nature of
man, and at the same time commanded by his
loftiest aspirations, this benevolent, this hu-
mane association of the entire race becomes
one of the grand leading ideas in the history of
mankind"(*^^).

With these words, which draw their charm
from the depth of the feelings that gave them

birth, be it allowed the Brother to conclude
this general representation of the natural phe-
nomena of the universe. From the farthest
nebulae of heaven, and from revolving double
stars, we have come down to the smallest or-
ganisms of the animal creation that live by sea
and land, and to the delicate vegetable germs
that cover the rocks on the flanks of snow-clad
mountain summits. Here we have found that
the phenomena could be arranged according to
laws which are partially known. Laws of an-
other and a mysterious kind come into play in
the higher circles of life in the organic world ;
in those especially that are occupied by the ra-
ces of mankind variously conformed, endowed
with creative mental energies, and gifted with
the faculty of inventing language. A physical
Delineation of Nature indicates the boundary
where the sphere of intelligence begins, and the
far-piercing glance is lost in another world. It
indicates, but does not pass the boundary.

<&(

NOTES TO PRECEDING SECTION.

1 (p. 29.) — The optical considerations on the differences
which a single luminous point or a disc of measurable an-
gle presents, in which the power of light remains the same
at every distance, maybe found discussed by Arago, Analyse
des travaux de Sir William Herschel (Annuaire du Bu-
reau des Long. 1842, p. 410-412. and 441.)

2 (p. 29.) — " The two Magellanic clouds, Nubecula ma-
jor and minor, are highly remarkable objects. The larger
cloud is an aggregation of stars, and consists of clusters of
■tars of irregular configuration, of globular clusters and
nebulous stars of different sizes and densities. Between
these lie large nebulie which are not resolvable into stars,
which apparently are star dust, and even with the 20-feet
telescope present themselves only as a general luminous-
ness of the field, as a brilliant back-ground, upon which
other objects of very remarkable and incomprehensible con-
figuration are scattered. In no other part of the heavens
are so many clusters of nebulse and of stars collected to-
gether within so small a compass as in this cloud. The
Nubecula minor is much less beautiful; it shows a larger
quantity of unresolvable nebular light, and the groups of
stars it includes are fewer in number and smaller." — Letter
from Sir John Herschel, dated Feldhuysen, Cape of Good
Hope, June 13. 1836.

3 (p. 29.) — The fine expression, xrf/Jroj ovpavou, which
Hesychius borrows from an unknown poet, I have rendered
as above by the phrase "garden of heaven ;" xoRroi may,
perhaps, rather signify an enclosed place, and would then
be better translated, the celestial space. The connection
of the word with the German garten, English garden, (Goth-
ic gards, according to Jacob Grimm, from gairdan, cingere,
to gird,) is, however, not to be overlooked, any more than
the affinity with the Sclavonian grad, gorod, and, as re-
marked by Pott (Etymol. Forsch. Th. i. S. 144), with the
Latin chors, (whence the modern words corte, court, cours),
and the Ossetic khart. The northern gard, gard, a fence,
an enclosure, and a country-seat ; and the Persian gerd,
gird, a circle, and also a princely country-seat, a castle, a
town ; as in the old names in Firdusi's Schahnameh : Siya-
wakschgird, Daral)gird, &c.

4 (p. 30.)— For u Centauri, vide Maclear, in Trans. As-
tronom. Soc., vol. xii. p. 370. More probable mean error
0"0640: for 61 Cygni, vide Bessel, in Schum. Jahrbuch,
1839, S. 47—49, and in Schum. Astronom. Nachr. Bd. 17,
S. 401, 402 Mean error 0"0I41. On the relative distan-
ces of stars of different orders, as those of the third magni-
tude are probably three times more distant, and as to how
we are to imagine the strata of stars in their bodily config-
uration, 1 find in Kepler's Epitome Astronomiae Copernica-
nae, 1618, tom. i. lib. i. p, 34—39, a remarkable passage:
" Sol hie noster nil aliud est quam una ex fixis, nobis major
et clarior visa, quia proprior quam fixa. Pone terram stare
ad latus, una semidiametro viae lacteae, tunc haec via lac-
tea apparebit circulus parvus, vel ellipsis parva, tota decli-
nans ad latus alterum ; eritque simul uno intuitu conspicua,
qua nunc non potest nisi dimidia conspici quovis momento.
Itaque fixarum sphaera non tantum orbe stellarum, sed etiam
circulo lactis versus nos deorsum est terminata."

» (p. 31.) — " Si dans les zones abandonn6es par I'atmo-
sph^re du soleil il s'est trouv6 des molecules trop volatiies
pour s'unir entre elles ou aux planetes ; elles doivent en
continuant de circuler autour de cet astre offrir toutes les
apparences de la lumiere zodiacale, sans opposer de resis-
tance sensible aux divers corps du systeme plan6taire, soit
& cause de leur extreme raret6^ soit parce que leur mouve-
ment est a fort peu pres le mfime que celui des planetes
qu'elles rencontrent."— Laplace, Exp. du Syst. du Monde,
(5e ed.) p. 415.

6 (p. 31.)— Laplace, loc. cit. p. 396 and 414.

7 (p. 31.) — Littrow, Astronomic, 1825, Bd. ii. S. 107.
Madler, Astr. 1841, S. 212. (Laplace, loc. cit. p. 210.)

8 (p. 31.)— Kepler on the decreasing density and increas-
ing volume of the planets, with their distance from the sun,
which IS described as the most dense of all bodies ; vide his
Epitome Astron. Copern. in vii. libros digesta, 1618 — 1622
p. 420. Leibnitz was also of Kepler's and Otto von Gue-
ricke's opinion, that the planets increase in volume in pro-
portion to their distance from the sun. Vide his Brief an
den Magdeburger Burgermeister (Mainz, 1671), in Leibnitz,
deutschen Schriften, herausg. von Guhrauer, Th. i. S. 264.

9 (p. 31.)— For a co ordination of the masses, see Encke,
in Schum. Astr. Nachr. 1843, Nr. 488, S. 114.

t.^V,t^f:l7l}^ ?? sehiidiameter of the moon, according
to Burckhardt's determination, be 02725, and Its volumi
T»o 9' ''* density would then come out 0-5596 • nearly l-
^^'^ M^ll^- ^^" S"^ ?• ^^'Jler, der Mond, S. 1 und 10.
wie Madler, Astr. S. 157. The actual contents of the moon,
acording to Hansen, equal -g\, according to Madler, ^.^
of the material contents of the earth ; its mass j-»^ that
of the earth. In the case of the largest of airjuniter's
satellites, the third, the relations to the primary in volume
f '■'' rswro ; 'n tlie mass, yy^. On the oblateness of
Uranus, vide Schum. Astron. Nachr. 1844, Nr. 493

11 (p. 33.)— Beer und Madler, 1. c. ^ 185, S. 208, u. (f 347
S. 332 ; also their Phys. Kenntniss der himml. Korner. S*
4 und 69, Tab. i. '

12 (p. 34.)— The four oldest comets whose orbits hava
been calculated — and this from Chinese observaMons— are
those of the years 24 (under Gordiau 111.), 539 (under Jus-
tinian), 565 and 837. Whilst the last of these comets was
less than 500,000 miles from the earth, and Louis the Pious,
greatly alarmed, was seeking to avert the presumed danger
by founding various monasteries, the Chinese astronomers
were following quite scientifically the course of the star,
whose tail, 60° in length, appeared first simple and then
divided. The first comet which could be calculated from
European observations alone, is that of 1456, (those of Hal-
ley, which were long but incorrectly regarded as the first
accurate elements). Vide Arago, in Annuaire, 1836, p 204
See, also, under Note 26.

13 (p. 34.)— Arago, in Annuaire, 1832, p. 209—211. In
the same way as the tail of the comet of J402 was seen in
bright sunshine, so was the last great comet of 1843 seen
both in Its nucleus and tail between 1 and 3 o'clock on the
28th of February by J. G. Clarke, of Portland, Maine, U. S.
Distances of the extremely dense nucleus from the sun's
edge could be measured with great accuracy. The nucleus
and tail presented themselves as a very pure white cloud ;
only between the tail and the nucleus there was a darker
space. — American .Journal of Science, vol. xlv. No. l,p 229
(Schum. Astr. Nachr. 1843, Nr. 491, S. 175.)

1-* (p. 34.) -Phil. Trans, for 1808, pt. ii. p. 155, and for
1812, pt. I. p. 1J8. The diameters of the nuclei found by
Herschel were 538 and 428 English miles. For the dimen-
sions of the comets of 1798 and 1085, vide Arago, in An-
nuaire pour 1832, p. 203.

15 (p. 35.)— Arago des changemens physiques de la Co-
mete de Halley du 15—23 Oct. 1835, in Ann. 1836, p. 218—
221. The more usual direction of the tail or emanation
was observed in Nero's time : " Comae radios solis effu-
giunt." Seneca, Nat. Quaest. vii. 20.

lt> (p. 35.)— Bessel, in Schum. Astr. Nachr. 1836, Nr.
300-302, S. 188, 192, 197, 200, 202, und 230. Also in
Schum. Jahrb. 1837, S. 149—168. W. Herschel also be-
lieved that he had observed the rotation of the nucleus and
tail lu his observations on the beautiful comet of 1811
(Philos. Trans. 1812, pt. i. p. 140.) So, also, Dunlop in the
third comet of 1825 at Paramatta.

17 (p. 35.) -Bessel, in Astr. N.lchr. 1836, Nr. 302, S. 231,
(Schum. Jahrb. 1837, S. 175). Vide, also. Lehmann uber
Cometenschweife in Bode*s Astron. Jahrb. fur 1826, S. 168.

18 (p. 35.)— Aristot. Meteor, i. 8, 11—14 und 19—21 (ed*
Ideler t. i. p. 32—34). Biese, Phil, des Aristoteles, Bd. ii.
S. 86. In the influence which Aristotle exerted on the
whole of the middle ages, it is infinitely to be lamented that
he showed himself so inimically disposed to the grand views
of the structure of the universe espoused by the old Pytha-
goreans, and which approached the truth so closely. He de-
clares the comets to be transient meteors belonging to our
atmosphere, in the same book in which he quotes the opin-
ion of the Pythagoreans to the effect that comets were
planets with long periods of revolution. This doctrine of
the Pythagoreans, which, however, from the testimony of
Apollonins Myndius, appears to be much older, and to have
been that of the Chaldeans, passed over to the imitative .
Romans. The Myndian describes the orbits of comets aa
passing far into the upper celestial spaces. Whence Seneca
(Nat. Quaest. vii. 17) : " Cometes non est species falsa, sed
proprium sidus sicut solis et lunae: altiora mundi secat et
tunc demum apparet quum in imum cursum sui venit ;" and
(vii. 27): " Cometas seternos esse et sortis ejusdem,' cuius
cstera (sidera), etiamsi faciem illis non habent similem.**

112

NOTES TO PRECEDING SECTION.

Pliny, too, evidently plays upon Apollonius' words, when
he says, "Sunt qui et hsec sidpra pcrpetua esse credant
suoque ambitu ire, sed non nisi relicta a sole cerni."

l^» (p. 35.)— Olbers, in the Astr. Nachr. 1828, S. 157, 184.
Arago, de la constitution physique des cometes im Annuaire
de 1832, p. 203 — 208. The ancients had already seen it as
remarkable that we can see through comets as through a
flame. The oldest testimony to stars having been seen
through comets, is that of Democritus (Aristot. Meteorol.
i. 6, 11). This statement leads Aristotle to the not unim-
portant observation, that he himself had seen the occulta-
tion of one of the stars of Gemini by Jupiter. Seneca very
certainly refers to the trans! ucency of the tail only (Nat.
Quxst. vii. 18) : " Non in ea parte qua sidus ipsum est
spissi et solidi ignis, sed qua rarus splendor occurrit et in
crines dispergitur. Per intervalla ignium, non per ipsos"
(vii. 26). The last portion of the remark is superfluous, as
we do positively See through a flame if it be not too thick,
as remarked by Galileo (Lettera a Mons. Cesarini, 1619).

20 (p. 35.)— Bessel in den Astr. Nachr. 1836, Nr. 301, S.
204 — 206. Struve im Rocneil des Mem. de I'Acad. de St.
Pet. 1836, p. 140-143, and Astr. Nachr. 1836, Nr. 303.
" For Dorpat, the star during the conjunction, was only
2"'2 from the brightest point of the comet. The star re-
mained steadily visible, and was not sensibly weakened ;
whilst the nucleus of the comet appeared to be extinguished
beside the brilliancy of the minute star (9th to the 10th
magnitude)."

21 (p, 35.) — The first attempts of Arago to apply polariza-
tion to Comets were made on the 3d July, 1819, the evening
of the sudden appearance of the great comet. I was present
in the observatory, and along with M. Mathieu and the late
M. Bouvard, was satisfied of the inequality of the strength
of light in the polariscope when it received the light of the
comet. With Capella, which was near the comet, and
about the same altitude, the images were of like intensity.
When Halley's comet appeared in 1835, the apparatus was
so altered that it gave two images of complementary col-
ours— green and red, according to the discovery by Arago
of chromatic polarization. Armales de Chimie", t. xiii. p.
108. Annuaire, 1832, p. 216. " On doit conclure," says
Arago, "de I'ensemble de ces observations que la lumiere
de la comete n'etait pas en totalite compos6e de rayons
doues des propriei6s de la lumiere directe, propre ou assim-
ilee : il s'y trouvait de la lumiere reflechie sp^culairement
ou polarisee, c'est-A-dire venant du soleil. On ne peut as-
surer d'une maniere absolue que les cometes brillent seule-
ment d'un eclat d'ernprunt. En eflTet en devenant lumineux,
par eux-m^mes, les corps ne perdent pas i)our cela la faculte
de r6flechir des lumieres etrangeres."

3i (p. 36.)— Arago, in Ann. 1832, p. 217—220. Sir John
Herschel, Astron. ^ 488.

23 (p. 36.)— Encke, in the Ast. Nachr. 1843, Nr. 489, S.
130—132.

24 (p. 36.)— Laplace, Exp. du Syst. du Monde, p. 216 and
237.

25 (p, 36.)— Littrow, Beschreibende Astr. 1835, S. 274.
On the inner comet lately discovered by M. Faya, of the
Parisian Observatory, whose excentricity is 0 551, perihe-
liac distance 1 690, and apheliac distance 5-832, Schuni.
Astr. Nachr. 1844, Nr. 495.

26 (p. 37 ) — Laugier, dans les Comptes, rendus des Stan-
ces de I'Acad. 1843, t. xvi. p. 1006.

27 (p. 37.) — Fries, Vorlesungen iiber die Stemkunde 1833,
S. 262— 267. A not very fortunate argument for the benefi-
cent nature of comets occurs in Seneca, who speaks (Nat.
Qusest. vii. 17 and 21) of the comet, " Quem nos Neronis
principatu laetissimo vidimus et qui cometis detraxit infami-
am."

28 (p. 38.) — One of my friends, accustomed to trigonomet-
rical surveys, saw his chamber illuminated by a fire-ball at
mid-day, and while the sun was shining, in the town of Po-
payan (N. lat. 2° 26' ; 5520 feet above the sea level). He
was standing with his back to the window, and when he
turned round a great portion of the course traversed by the
ball was still most brilliantly lighted. The titles for falling-
stars are often extremely "vulgar : the Germans speak of
them as star-snuffs : according to the vulgar idea the lights
of heaven want snuffing. In the woody country of the Ori-
noco, and on the solitary banks of the Cassiquiare, the shoot-
ing stars were designated by the natives star-urine, and the
dew which lay on the beautiful leaves of the Heliconias hke
pearls, was star-spittle. The Lithuanian Mythus gives a
more noble and imaginative interpretation of the nature and
significance of falling stars ; " The spinstress Werpeja be-
gins to spin the thread of the destiny of the new-born child,
and each of these threads ends in a star. And then when
death approaches the man, the thread breaks and the star
falls, quenching its light, to the earth."— Jacob Grimm,
deutsche Mythologie, 1843, S. 685.

29 (p. 38.)— From the account of Denison Olmsted, Profes-
sor of Yale College, New Haven, Connecticut, IJ. S., vide
Poggendorif's Annaleu der Physik, Bd. xxx. S. 194. Kep-
ler, who banishes falling stars from astronomy, they being,

according to him, mere meteors, engendered by emanatioM
from the earth, still expresses himself very cautiously m
regard to them. " Stellaj cadenles," says he, " sunt materia
viscida inflammata. Earum aliquae inter cadendum absu-
muntur, aliqu* vere in terram cadunt, pondere suo tractaj.
Nee est dissimile vero, quasdam conglobatas esse ex mate-
ria foBCulentA, in ipsam auram ffitheream immixta: exque
aetheris regione, tractu rectilineo, per aerem trajicere, ceu
minutes cometas, occultA causa motua utrorumque." — Kep-
ler, Epit. Astron. Copernicanae, t. i. p. 80.

30 (p. 38.)— Relation historique, t. i. p. 80, 213, and 527.
If we distinguish a head or nucleus and a tail in falling stais
as in comets, we are made aware of the greater transparency
of the atmosphere iix tropical regions by the greater length
and brilliancy of their trains. The phenomenon need not
therefore be more frequent because it is more readily seen,
and remains longer visible. The influence of the state ol
the atmosphere also shows itself occasionally in connection
with falling stars even in our temperate zone, and at very
short distances. Wartmanu informs us, that on occasion
of one of the November phenomena, the difference between
the number of meteors seen at Geneva, and at Planchettes,
two places very near to one another, was 1 : 7 (Mfem. sur les
Etoiles filantes, p. 17). The train of the falling star, upon
which Brandes has made so many accurate and delicate ob-
servations, is by no means to be ascribed to the continuance
of the impression of light upon the retina. It sometimes
continues visible for a whole minute ; in rare cases even
longer than the light of the head of the falling star. The
luminous track then usually remains motionless (Gilb. Ann.
Bd. xiv. S. 251). This circumstance also proclaims the
analogy between large shooting stars and fire-balls. Admi-
ral Krusenstern, in his voyage round the world, saw the
tail of a fire-ball that had long vanished, remain visible for
an hour, with very little apparent motion (Reise, Th. i. S.
58). Sir Alexander Burnes gives a charming account of the
transparency of the dry atmosphere of Bokhara (N. lat. 39^
43', 1200 feet above the sea-level), so favourable formerly
to the study of astronomy : " There is a constant serenity
in its atmosphere, and an admirable clearness in the sky.
At night, the stars have uncommon lusire, and the milky-
way shines gloriously in the firmament. There is also a
never-ceasing display of the most brilliant meteors, which
dart like rockets in the sky ; ten or twelve of them are
sometimes seen in an hour, assuming every colour; fiery,
red, blue, pale and faint. It is a noble country for astro-
nomical science, and great must have been the advantage
enjoyed by the famed observatory of Samarkand." Burnes'
Travels into Bokhara, vol. ii. (1834) p. 158. We must not
charge ic upon the solitary traveller that he speaks of ten
or twelve falling stars in an hour as many ; it has but lately
been discovered, from careful observation, that eight meteors
per hour are the mean number that fall within the circle of
vision of an individual (vide Quelelet, Correspond. Mathem.
Nov. 1837, p. 447.) Olbers, the acute observer, reduces
this number to from five to six. (Schum. Jahrb. 1838, S.
325.)

31 (p. 38.) — On meteoric dust, vide Arago, in Annuaire
pour 1832, p. 254. I have very lately in another place ( Asie
centrale, t. i. p. 408) endeavoured to show how the Scythian
myth of the sacred gold that fell glowing from heaven, and
remained the property of the golden hordes of Paralatae
(Herod, iv. 5 — 7), may have been the obscure recollection
of the fall of an Aerolite. The ancients also had their fa-
bles (Dio Cassius, Ixxv. 12.')9) strangely enough of silver that
fell from heaven, and with which attempts were made to
plate the copper money under the Emperor Severus. Me-
tallic iron was nevertheless recognized in meteoric stones
by Pliny (ii. 56). The frequently recurring phrase lapidi-
bus pluit, must not be always viewed as referring to aero-
lites. In Livy (xxv. 7) it is used in connection with the re-
jected masses — pumice, rapilli, of the not quite extinct vol-
canic Mons Albanus, Monte Cavo : vide Heyne, Opusc.
Acad. t. iii. p. 261, and my own Relation historique, t. i. p.
394. To another circle of ideas belongs the conflict of Her-
cules against the Ligyes, on the way from Caucasus to the
Hesperides. It is an attempt mythically to explain the ori-
gin of the rounded quartz blocks in the Ligyan stone field
at the mouth of the Rhone, which Aristotle ascribes to aa
earthquake, Posidonius to the action of the waves of an in-
land sea. But in the fragments of the Prometheus Unbound
of .^schylus, all goes forward as in a fall of Aerolites : Ju-
piter draws together a cloud, and " covers the land with a
shower of rounded stones for rain." Posidonius allows him-
self to jest at the geological myth of the fragments and
blocks. The Ligyan stone field for the rest is faithfully de-
scribed by the ancients. The country is now called La
Crau. — Guerin, Mesures barometriques dans les Alpes et
M6t6orologie d'Avignon, 1829, ch. xii. p. 115.

32 (p. 39.) — The specific gravity of Aerolites varies be-
tween 1-9 (Alais) and 4-3 (Tabor). The more common den-
sity is about 3, water being assumed as 1. What is stated
in the text in regard to the actual diameter of fire-balls, is
based on the few sfitisfactory measurements we possess.

NOTES TO PRECEDING SECTION.

113

These for tlie fire-ball of Weston (Connecticut, Dec. 14,
1807) assign 500, for the one observed by Le Roi (10th July,
1771) about 1,000, and for that seen by Sir Charles Blagden
{18th Jan. 1783) as many as 2,600 feet in diameter. Brandes
(Unterhaitung. Ed. i. S. 42) assig;ns from 80 to 120 feet to
shooting stars ; their luminous tails being from 3 to 4 miles
in length. But there are not wanting optical grounds for
believing that the apparent diameter of fire-balls and shoot-
ing stars is greatly over-estimated. The volume of fire-
balls is certainly not to be compared with the volume of
Ceres (even supposing this planet to be no more than 70
English miles iu diameter, as has been estimated) : see the
accurate and admirable treatise, On the Connexion of the
Physical Sciences, 1835, p. 411. I here add in illustration
of what has been said at page 39, of the great Aerolite of
the bed of the river Narai, the passage from the Chronicon
Benedicti, monachi Sancti Andre;e in Monte Soracte, which
has been referred to by Pertz, a document of the 10th cen-
tury, and that is preserved in the Biblioteca Chigi at Rome.
The barbarous writing of the time is preserved unaltered :
** Anno— 921— temporibus doraini Johannis Decimi pape, in
wnno pontificatus illius 7, visa sunt signa. Nam juxta ur-
bem Roman lapides plurimi de coelo cadere visi sunt. In
civitate quse vocatur Narnia tarn did ac tetri, ut nihil aliud
credatur, quam de infernalibus locis deducti essent. Nam
ita ex illis lapidibus unus omnium maximus est, utdecidens
in flumen Nanms, ad mensuram unius cubiti super aquas
fluminis usque hodie videretur. Nam et ignitEe faculae de
ccelo plurima; omnibus in hac civitate Romani populi visae
Bunt, ita ut pene terra contingeret, Alise cadentes," &c. —
(Pertz, Monum. Germ. hist. Scriptores, t. iii. p. 715.) On
the Aerolites of Aegos Potamos, whose fall the Pariscan
Chronicle states to have happened in the 78" 1 Olympiad
{Bcickh, Corp. Inscr. Grsc. t. ii. p. 302, 320, and 340).
Aristot. Meteor, i. 7 (Ideler, Comm. t.i. p.404 — 407) ; Stob.
Eel. Phys. i. 25 p. 508, Heeren ; Plut. Lys. c. 12 ; Diog.
Laert. ii. 10. (And aiso under the Notes 39, 57, 58, and 59. )
According to a MongoHan tradition, a black rocky mass, 40
feet in height, is said to have fallen from heaven in a plain
near the sources of the Yellow River in Western China. —
Abel-R6niusat, in Lam6therie, Journ. de Phys. 1819, Mai,
p. 264.

33 (p, 39.)— Biot, Traitfe d'Astronomie physique, (3me
*d.) 1841 t. i. p. 149, 177, 238, and 312. My immortal friend
Poisson attempted the solution of the difficulty of sponta-
neous combustion occurring in an aerolite in a region where
the density of the atmosphere is almost nil, in a very pecu-
liar manner. He says, "A une distance de la terre oti la
densite de I'atmosphere est tout-A-fait insensible, il serait
difficile d'attribuer, coinme on Icfait, I'incandesccnce des
aerolithes a uii frottement contre les moldcules de Tair. Ne
pourrait-on pas supposer que le fluide 61ectrique a I'^tat
neutre forme une sorte d'almosphere, qui s'etend beaucoup
au-dela de la masse d'air ; qui est souniise i I'attraction de
la terre, quoique physiqueraent imponderable; et qui suit,
«n consequence, notre globe dans ses mouvements 1 Dans
cette hypothese, les corps dont il s'agit, en entrant dans
cette atmosphere imponderable, d^composeraient le fluide
neutre, par leur action in^gale sur les deux 61ectricites, ct
ce serait en s'electrisantqu'ils s'^chaufferaientetdeviendra-
ient incandescents." — (Poisson, Rech. sur la Probability des
Jugements, 1837, p. 6.)

34 (p. 39.)— Philos. Transact, vol. xxix. p. 161—163.

35 (p. 39.) — The first edition of Chladni's important treat-
ise, On the origin of the masses of Iron discovered by Pallas
and others, appeared two months before the shower of stones
fell at Siena, and two years before Lichtenberg's proposi-
tion, " that stones come into our atmosphere from universal
space," in the Gottingen Pocket-Book. — Vide Olbers' Letter
to Benzenberg of Nov. 18th, 1837, and the latter's work on
Falling Stars, p. 186.

3G (p. 39.)— Encke, in Poggend. Annalen, Bd. xxxiii.
(1834) S. 213. Arago, in Ann. pour 1836, p. 291. Two let-
ters of mine to Benzenberg, 19th May and Oct. 22d, 1837,
on the supposed precession of the nodes in the orbit of the
periodic streams of shooting stars (Benzenb. Sternsch. S.
207 and 209). Olbers, too, subsequently came into this
opinion of the gradual retardation of the November phenom-
enon (Astron. Nachr. 1838, No. 372, S. 180). If I venture
to connect two of the falls of shooting stars indicated by the
Arabian writers with those discovered by Boguslawski, as
haviijg occurred in the 14th century, I obtain the following
more or less accordant elements of the nodal movement :

In October 902, in the night of the death of King Ibrahim-
ben- Ahmed, there was a great fall of stars, " like a fiery
rain." This year was on this account called the year of the
stars. — (Conde. Hist, de la domin. de los Arabes, p. 346.)

Oct. 19th, 1202.— Stars fell the whole night through;
"they fell like locusts." — (Comptes-rendus, 1837, t. i. p.
294, and Fraehn, in Bull, de I'Acad. de St. Petersbourg, t.
iii. p. 308.)

Oct. 21, old style, 1366, die sequente post festum xi. mil-
lia Virgiuum ab hora niatutina usque ad horam priman visa;
sunt quasi stellae de cslo cadere contiuuo, et in tanta mul-

P

titudine, quod nemo narrarc sufficit. This remarkable no-
tice, of which more use wil' be made further on in the text,
was discovered by M.von Boguslawski, Jun. in Benesse (de
Ilorowic) de W«itniil or Weithmiil's Chronicon Ecclesia
Pragensis, p, 389. This chronicle is republished in the 2«1
part of the Scriptores rerum Bohcmicarum von Pelzel und
Dobrowsky, 1784 (Schum. Astr. Nachr. Dec. 1839).

Night of Nov, 9—10, 1787, many shooting stars obsenred
by Hemmer in South Germany, particularly in Manheim.
— (KcEmtz, Meteorol. iii. 237.)

Midnight, Nov. 12, 1799.— The extraordinary fall of stars,
which Bonpland and I have described, and which was ob-
served over the greater part of the globe.— (Vide Relat.
Hist. t. i. p. 519—527.)

Nov. 12—13, 1822, shooting stars mingled with fire-balls,
in great numbers, seen by Kloden, in Potsdam (Gilbert's
Annalen, vol. 72, p. 291).

Nov. 13th, 1831, at four a.m., a great fall of stars seen by
Captain B^rard on the coast of Spain, near Carthagena del
Levante (Annuaire, 1836, p. 297).

Night of Nov. 12—13, 1833.— The remarkable North
American phenomenon so admirably described by Denisoa
Olmsted.

Night of Nov. 13—14, 1834.— The same phenomenon, but
not so brilliant, observed in North America (Poggendorff,
Ann. Bd. xxxiv. S. 129).

Nov. 13th, 1835, a stack was set on fire by a single fire-
ball near Belley, D6p. de I'Ain (Annuaire, 1836).

In the year 1838, the stream of shooting stars showed it-
self most decidedly in the night from the 13th to the 14th
November (Astronom. Nachrichten, 1838, No. 372).

37 (p. 39.) — It is not unknown to me that of the 62 shoot-
ing stars which were simultaneously observed in Silesia, at
the instance of Prof. Brandes, some appeared to have had
an elevation of 'i^jgt of 60 and even of 100 miles, vide
Brandes, Unterhaltungen fiir Freunde der Astronomic und
Physik, Heft i. S. 48. But Olbers, by reason of the small-
ness of the parallax, regards all determinations above 30
miles in height as doubtful.

38 (p. 39.) — The velocity of, the planets in their orbits
varies greatly ; for Mercury it is 6'6, for Venus 4*8, and for
the Earth 4*1 German miles per second.

39 (p. 40.) — Chladni discovered that an Italian natural
philosopher, Paolo Maria Terzago, 1660, on the occasion of
a fall of aerolites at Milan, in which a monk was killed, was
the first who spoke of the possibility of aerolites being moon-
stones : " Labant philosophorum mentes," says he, in his
work, Musaeum Septalianum, Manfredi Septalae, Patricii
Mediolanensis, industrioso labore constructum, Tortona,
1664, p. 44, "sub horum lapidum ponderibus ; ni dicere
velimus, lunam terrain alteram, sive mundum esse, ex cujus
monlibus divisa frustra in inferiorem nostrum hunc orbem
delabantur." Without having any knowledge of this con-
jecture, Olbers was led in the year 1795, after the great fall
of stones that took place at Siena (16th June, 1794), to the
inquiry of — how great the original projectile force must be
to send masses from the moon to the earth T And a prob-
lem of this kind found occupation for such minds as La-
place, Biot, Brandes, and Poisson, for some ten or twelve
years. The opinion ouce very generally entertained, but
now abandoned, of the existence of active volcanoes in the
moon without atmosphere and without water, favoured in
the public mind the confusion of a mathematical possibility
with a physical probability — an explanation of a physical
fact preferable to other explanations. Olbers, Brandes, and
Chladni, believed that they had discovered a refutation
of the lunar origin of meteoric stones in the relative velo-
city of from 4 to 8 miles, with which fire-balls and shoot-
ing stars enter our atmosphere. To reach the earth, ac-
cording to Olbers, without bringing the resistance of the
air into the reckoning, an original velocity of 7780 feet per
second were requisite ; according to Laplace, the necessary
velocity is 7377 feet ; according to Biot, 7771 feet ; and ac-
cording to Poisson, 7123 feet. Laplace calls this primary
velocity only from 5 to 6 times greater than that which a
cannon-ball possesses as it leaves the gun ; but Olbers has
shown, " that with such a primary velocity of from 7500 to
8000 feet per second, meteoric stones would only reach the
confines of our atmosphere with a velocity of 35,000 feet"
(1*53 German geographical mile). But as the measured
velocity of meteoric stones is in the mean 5 geographical
miles, or more than 114,000 feet per second, they must ori-
ginally have had a centrifugal force in the moon of 110,000
feet per second, fourteen times greater therefore than La-
place assumes. (Olbers in Schum. Jahrb. 183T, S. 52 — 58
und in Gehler's Nues physik. Woterbuche, Bd. vi. Abth.
3, S. 2129—2136.) The absence of any resistance from the
air would, however, give the projectile force of the lunar
volcanoes an advantage beyond the projectile force of our
volcanoes on the earth, supposing always that volcanic ac-
tion is conceived as possible in the body of the moon ; but
upon the amount or measure of the power of these lunar
volcanoes, we are still without any information. It is very

114

NOTES TO PRECEDING SECTION.

probable indeed that this amount has been greatly over-es-
timated. A very accurate observer and measurer of the
power of jEtna, Dr. Peters, has found the greatest velocity
of stones cast out from its crater to be but 1250 feet per
second. Observations on the Peak of Teneriffe in 1798 gave
3000 feet. If Laplace, at the end of his work (Expos, du
Syst. du Monde, 1824, p. 399), says very considerately,
" que selon toutes les vraiseniblaiices elles vienncnt des pro-
fondeurs de I'espace celeste ;" we still find him in another
place, probably unacquainted with the amazing, wholly
planetary velocity of meteoric stones (Chap. vi. p. 233), re-
verting to the selenitic hypothesis with a kind of preference,
but always premising that the stones cast out from the
moon "deviennent des satellites de la terre, d6crivant au-
tour d'elle une orbite plus ou moins allongee, de sorte (lu'ils
n'atteignent I'atmosph^re de la terre qu'apres plusieurs et
m^me un tr^s-grand nombre de revolutions." In the same
way as an Italian of Tortona conceived the fancy that aero-
lites came from the moon, Greek philosophers had a notion
that they came from the sun. Diogenes Laertius (ii. 9) ad-
verts to such an op-nion when treating of the origin of the
mass which fell at ..Egos Potamoi {vide Note 32 above) ; and
Pliny, who registers every thing, mentions the idea, and
ridicules it the more willingly, because with earlier writers
(Diog. Laert. ii. 3 and 5) he excuses Anaxagorus for having
predicated a fall of stones from the sun : " Celebrant Gr«oi
AnaxagoramClazomenium Olympiadisseptuagesimceoctavse
secundo annoprxdixisse cielestium litterarum scientia, qui-
bus diebus saxum casurum esse e sole, idque factum inter-
diu in Thraciffi parte ad Aegos flumen. Quod si quis prte-
dictum credat, simul fateatur necesse est, majoris miraculi
divinitatem Anaxagorae fuisse.solvique rerum naturte intel-
lectum, et confundi omnia, si aut ipse Sol lapis esse autun-
quam lapidem in eo fuisse credatur ; decidere tamen crebro
non eritdubium." Anaxagoras is also said to have foretold
the fall of the stone of smaller dimensions, which was pre-
served in the Gymnasium of Abydos. Falls of afirolites
during sunshine, and when the disc of the moon was not
visible, probably gave rise to the idea of the sun as their
source. It was also one of the physical dogmas of Anaxa-
goras, and which, as in the case of the geologists of these
our own times, exposed him to the persecution of the theo-
logians, that the sun was " a molten fiery mass {ixiiSpns
iidtsvpoi)." In the Phaeton of Euripides the sun. after the
same views of the Clazonienaean, is called a "golden clod,"
i. e., a fiery-coloured luminous mass of matter ; from which,
however, we are not to conclude that aerolites are "golden
sun-stones" Vide Note 31, above; as also Valckenaer,
Diatribe in Eurip. perd. dram. Reliquias, 1767, p. 30. Diog.
Laert. ii. 40. We seem, then, to find four hypotheses
among the Greek natural philosophers : a telluric origin of
falling stars from ascending vapours ; masses of stone raised
by tempests, in Aristotle (Meteorol. lib. i. cap. IV. 2 — 13,
and cap. vii. 9) ; an origin from the sun ; an origin from
celestial space, and as heavenly bodies that had long re-
mained invisible. On the last view of Diogenes of Apol-
lonia, which entirely agrees with our own, see the text (p.
43), and Note 58. It is remarkable that in Syria, as a learn-
ed Orientalist, my teacher of Persic, M. Andrea de Nericat,
assured nie, according to an old popular belief they are still
solicitous about falls of stones from the sky in very clear
moonlight nights. The ancients, on the contrary, were on
the watch for the same event during eclipses of the moon
(Plin. xxxvii. 10, p. 164 ; Solinus, o. 37 ; Salm. Exerc. p.
531) ; and the passages collected by Ukert, in his Geogra-
phy of the Greeks and Romans (Th. ii. 1, S. 131, Note 14).
On the improbability that aerolites arise from gases holding
metallic matters dissolved, which, according to Fusinieri,
exist in the upper strata of our atmosphere, and which pre-
viously dispersed in infinite space had suddenly coalesced,
as well as on the penetration and miscibility of gases, see
my Relation histor. t. i. p. 525.

■fO (p. 40.)— Bessel in Schum. Astr. Nachr. 1839, Nr. 380
uud 381, S. 222 und 346. At the close of the work there
is a comparis(m of the sun's place in longitude with the
epochs of the November phenomenon, since the first obser-
vations in Cumana, 1799.

•*i (p. 40.) — Dr. Thomas Forster (the Pocket Encyclop.
of Natural Phenomena, 1827, p. 17) informs us that in
Christ Church College, Cambridge, there is preserved a
MS. entitled " Ephemerides rerum naturalium," which is
ascribed to a monk of the last century. In this MS. natural
phenomena are noted as having occurred on every day of
the year: the flowering of plants; the arrival of birds of
passage, «fec. The 10th of August is characterized by the
word meteorodes. This indication and the tradition of tho
fiery tears of St. Lawrence, led Dr. Forster to pay particu-
lar attention to the August phenomenon.— Quetelet, Cor-
resp. malhem., s6rie iii. toni. i. 1837, p. 433.

42 (p. 40.)— Humboldt, Rel.hist. t. i., p. 519—527. Elli-
cot, in the Transactions of the American Society, 1804, vol.
vi. p. 29. Arago says of the November phenomencm, " Ainsi
ae confirme de plus en plus A nous I'existence d'une zone
compos^e de millions de petits corps dont les orbites rencoa-

trent le plan de I'^cliptique vers le point que la terre va oo
cuper tons les ans. du II an 13 Novenibre. C'est un nou-
veau monde plan6taire qui commence i se r6v61er t nous."
— Annuaire, 1836. p. 206.

43 (p. 40.)— Fide Musehenbroek, Introd. ad Phil. Nat.
1762, t. ii. p. 1061. Howard, Climate of London, vol. ii. p.
23, Observations of the Year 1806, therefore, seven years
after the earliest observations of Prof. Brandes (Benzenberg
ijlier Sternschnuppen, S. 240—244) ; August-Oiiservations
of Thomas Forster, vide Quetelet, loc. cit. 438 — 453 ; of
Adolph Ermaii, Buguslavvski und Kreil in Schum, Jahrb.
1838, S. 317—330. On the point in Perseus whence the
stream proceeded on the lOth of August, 1839, see the ac-
curate measurements of Bessel and Erman (Schum. Astr.
Nachr. Nos. 385 and 428) ; on the 10th of August, 1837,
however, the orbit did not appear to be retrograde ; see
Arago, in C^omples rendus, 1837, torn. ii. p. 183.

44 (p. 40.)— On the 25th of April, 1095, "innumerable
eyes in France saw the stars fall as thick as hail from
heaven" (ut grando, nisi lucerent, pro densitate putaretur ;
Baldr. p. 88) ; and this incident was regarded by the Coun»
cil of Clermont as premonitory of a greaf. movement in
Christendom. (Vide Wilken, Gesch. der Kreuzziige, Bd.
i. S. 75.) On the 22d of April, 1800, a great fall of stars
was observed in Virginia and Massachusetts ; it was like a
display of rockets that lasted for two hours. Arago first
directed attention to this " trainee d'asi Oroides*' as a recur-
ring phenomenon (Annuaire, 1836, p. 297). The falls of
aerolites in the beginning of December was also remarka-
ble ; their periodical recurrence is vouched for by the old
observations of Brandes in the night from the 6th to the 7th
of December, 1798, when he counted nearly 2000 falling
stars, and perhaps by the extraordinary fall of aerolites of
the 11th of December, 1836, at the village of Macao on the
river Assu, Brazil (Brande.% Unterhalt. fiir Freunde der
Physik, 1825, Heft i. S. 65, and Comptes rendus, torn. v. p.
211). Capocci, from 1809 to 1836, has found records of
twelve actual falls of aerolites between the 27th and the
29th of November: and several others of the 13th of No-
vember, 10th of August, and 16th of .luly (Comptes rendus,
tom. xi. p. 357). It is cumnis that in the part of the earth's
orbit which corresponds to the months of .lanuary and Feb-
ruary, and perhaps March, no periodical fall of shooting
stars has yet been noticed ; nevertheless I myself observed
a remarkable number of shooting stars on the 15th of March,
1803, in the South Pacific Ocean; and a shower of the
same was seen in the city of Quito shortly before the tre-
mendous earthquake of Riobamba (4th Feb. 1797). Th«
following epochs deserve the i)articular attention of ob-
servers ;

22-25 April,

17 July (17—26 July?) (Quet. Corr. 1837, p. 435),

10 August,

12—14 November,

27—29 November,

6—12 December.
The frequency of these streams, however great the differ-
ence between isolated comets and rings filled with asteroids,
ought not to excite astonishment when we think of th«
depths of universal space filled with myriads of (tomets.

45 (p. 41.) — Ferd. v. Wrangel, Reise langs der Nordkiist*
von Sibirien in den Jahren 1820—1824, Th. ii. S. 259. Ob
the return of the thicker shower of the November asteroid.s
every thirty-four years, vide Olbers in Jahrb. 1837, S. 280.
I was informed in Cumana, that shortly before the dreadful
earthquake of 1766, just thirty-three years, therefore, before
the great exhibition of shooting stars of November II — 12,
1799, the same display had been seen. But the earthquake
of 1766 did not occur in November, but on the 21st of Oc-
tol>er. It were worth the while of travellers in Quito to
investigate the particular day on which the volcano Cayam-
be appeared for an hour as if enveloped in a shower of fall-
ing stars, so that reliijious processions were set in motion
to appease the heavens 1 {vide mv Relat. histor. t. i. chap,
iv. p. 307 ; chap. x. p 520 and 527.)

46 (p. 41.)— From a letter to me of January 24, 1838.
The extraordinary display of shooting stars of 1799 was ob-
served almost e>C;usively in America, from New Ilerrnhut,
in Greenland, to the Equator. The phenomena of 1831 and
1832 were cmly seen in Europe ; those of 1833 and 1834
only in the United States of North America.

47 (p. 41.;— Leltre de Mr. Edouard Biot & Mr. Quetelet
sur les anciennes apparitions d'etoiles filantes en Chine, in
Bull, de I'Acad. de Bruxelles, 1843, t. x. No. 7, p. 8. On
the notice from the Chronicim Ecclesiae Pragensis, vide
Bogusiawski. Jun., in Poggend. Aiinalen, Bd. xlviii. S. 612.
To Note 12 should be added, that the orbits of four comets
(568, 574, 1337, and 1385) have been reckoned exclusively
from Chinese data. Vide John Russell Hind, in Schunx.
Astr. Nachr. 1844, Nr. 498.

43 (p. 41.) — " 11 parait qu'un nombre, qui semble in^pui-
sable, de corps trop jietits pour 6tre observ6s, se meuvent
dans le ciel, soit autour du soelil, soit autour des plan^tes,
soil peut-4tre m£me autour des satellites. On suppose que

NOTES TO PRECEDING SECTION.

115

Joand ces corps sont recontrts par notre atmosphere, la
iff6rence entre leur vitesse et celle tie noire plaiiete est
Bssez graiide pour que le frotleraent qu'ils 6prouvent cniitre
I'air, les ^chautfe au point do les reiuire incutidescents, et
quelquefois de les faire 6clater. Si le groups des 6ti>iles
lilantes forme an anrieau contiiiu autourdu soleil, sa vitesse
de circulation pourra Atre tres-diff^rente de celle de la
terre ; et ses d^placeinents dans le cii'l, par suite des actions

flan^taires, pourrons encore rendre possible ou impossible,
diffiiirentes epoques, le ph6nomene de la rencontre dans
le plan de l'6cliptique." — Poissou, Recherches sur la proba-
bilit6 des jugements, p. 306, 307.

O (p. 41.) — Humboldt, Essai politique sur la Nouv. Es-
pagne, 2e 6dit.) t. iii. p. 310.

60 (p. 41.)— Pliny shows himself to have been attentive
to the colour of the crust : colore adusto. The words, lot-
tribus pluisse, also refer to the burned external appearance
of Aerolites (ii. 56 and 58).

61 (p. 42.)— Humboldt, Rel. hist. t. ii. chap. xx. p. 299—
302.

63 (p, 42.)— Gustav Rose, Reise nach dem Ural, Bd. ii
S. 202.

63 (p. 42.)— Vide Poggend. Ann. 1825, Bd. iv. S. 173—
192. Ranimelsberg, Erstes Suppl. zum chem. Handworter- j
bache der Mineralogie, 1843, s. 102, " It is," says the acute i
Olhers, " a remarkable though unnoticed fact, that fossil i
meteoric stones have lieen found, like fossil shells, in sec- j
ondary and tertiary formations. Shall we thence feel at ;
liberty to conclude, that before the last and present ar- |
rangement of the surface of our earth, meteoric stones had
fallen upon it? Schreibers calculates that at this time i
there are about 700 falls of meteoric stones in each year." j
(Olbers, in Schuiu. Jahrb. 1838, s. 329.) Problematic '
nickeliferous masses of native iron have t)een lately found
in North Asia, (Goldseiferwerk von Petropawlowsk, 20 j
Biiles south-east of Kusnezk,) at ^distance of 31 feet deep, ;
and in the Western Carpathians (Magura, near Szlanicz). =
Both of these masses are extremely like Aerolites — Vide
Erman, Archiv fiir wisseiischaftliche Kunde von Russland,
Bd. i. S. 315, and Haidinger's Bericht iiber die Szlauiczer
Schiirfe in Ungaru.

64 (p. 42.) — Berzelius, Jahreslier. Bd. xv. S. 217 and
231 ; Rammelsberg, Handworterb. Abth. ii. S. 25—28. !

55 (p. 42.) — "Sir Isaac said, he took all the planets to
be composed of the same matter with this earth, viz.,earlh,
water, and stones, but variously concocted." — Turner, Col-
lections for the Hist, of Grantham, cont. authentic Memoirs
of Sir Isaac Newton, p. 172, j

56 (p. 43.)— Adolph Erman, in Poggend. Ann. 1839, Bd. |
xlviii. S. 582—601. Biot at a previous perioi/, (Comples
rendus, 1836, t, ii. p. 670) raised doubts of tAe probability
of the November phenomenon appearing ag?in in the begin-
ning of May. MSdler has taken the meon temperature of j
the three days of May that have been decried for the last j
86 years, according to Berlin observations, (Verhandl. des ;
Vereius zur Be ford, des Garte«baue» 1834,s. 377,) and finds ;
the temperature of the llth, 12th. and 13th of May to re- {
cede 10-22 C. precisely at a season when the advance in
the temperature is the most rxpid. It would be very desi-
rable that this phenomena (/ a fall of temperature, which
there has been an obvious disposition to ascribe to the fu-
sion of masses of ice in tAe north-east of Europe, were in-
vestigated at very diffe?««iit points of the continent of Amer- i
ica, or in the southeKi hemisphere- Vide Bull, de I'Acad. ;
Imp. de St.-Petersiourg 1843, t. i. No. 4. !

57 (p, 43.)— Plui. Vitae par. in Lysandro, cap. 22. The
account of Danvtchos (Daimachos), according to which a
fiery cloud wa/ seen for 70 days in succession, and which
emitted sparVs like falling stars, and finally sinking down,
de{)osited tke stone of ^gos Potamos, " which was but an
insignificaAt portion of the cloud," is extremely improbable,
because the course and direction of the fire-ball ntust then
have caatinued for many days like that of the earth. The
fire-b»n of the 19th of July, 1686, described by Halley, per-
formed its visible course in minutes (Philos. Trans, vol.
xi^x- P- 163). Whether Daimachos, the writer, -rrcpl ev-
tfcSeiui, is the same with the Daimachos of Platasa, who
WHS sent by Seleucus to India to the son of Androkottos, and
whom Strabo (p. 70, Casaub.) characterizes as a ''vender
of lies," remains uncertain. From another passage of Plu-
tarch (Compar. Solonis c. Pop. cap. 4),^ we should almost
be disposed to believe that he was. Vide Note 32.

58 (p.43.)— Stob. ed. Heeren, i. 25, p, 508, Plut. de plac,
Philos. ii. 13, !

69 (p. 43.)— The remarkable passage of Plutarch (De
plac. Philos. ii. 13) is the following : " Anaxagoras teaches
that the surrounding ether is fiery in respect of its sub-
stance ; and through the force of its circumvolution tears
away masses of rock from the earth, sets them on fire, and
turns them into stars." The Clazomensan employs the ,
same kind of force (centrifugal force) for bringing the Ne-
maean lion from the moon to the Peloponnesus. (Aelian
xii. 7 ; Plut. de facie in orbe lunae, c. 24 ; Schol. ex. Cod.
Paris, in Apoll. Argon, lib. i. p, 498, ed. Schaef. t. ii. p. t

40; Meineke, Annal. Alex. 1843, p. 85.) We have there-
fore in this instance moon auirnals instead of moon stones.
According to IVickh's acute remark, the old myth of th«
Nemsean lion of the moon lias an astronomical origin, and ia
connected symbolically in «.hr(»nology with the intercalary
cycles of the lunar year, the worship of the moon at Ne-
ma;a, and the games there celebrated.

<^ (p. 43.) — The following important passage, one of th«
many inspirations of Kepler on the radiation of heat by the
fixed stars, slow combustum and the vital processes, occurt
in the Paralipom. in Vitell. Asiron. pars optica, 1604,
Propos. xxxii. p. 25: " Lucis proprium est calor, sydera
omnia calefaciunt. De syderum luce claritatis ratio testa-
tur, calorem universorum in minori esse proportione ad
calorem unius solis, quam ut ab homine, cujus est certa
caloris mensura, uterque simul percipi et judirari possit.
De cincindularum lucula tenuissima iiegare non potes, quin
cum calore sit. Vivunt enim et moventur, hoc autem non
sine calefactione perficitur. Sed neque putrescentiura lig-
norura lux suo calore destituitur; nam ipsa puetredo qui-
dam lenlus ignis est. Inest et slirpibus suus calor." Vid«
Kepler, Epit, Astron. Copernicanae. 1618, t. i. lib. i. p. 35.

61 (p. 44.) — " There is another thing, which I recom-
mend to the observation of mathematical men; which is,
that in February, and for a little before, and a httle after
that month (as I have observed several years together),
about six in the evening, when the Twilight had almost de-
serted the horizon, you shall see a plainly discernible way
of the Twilight striking^ up towards the Pleiades, and
seeming almost to touch them. It is so observed any clear
night, but it is best illic nocte. There is no such way to b«
observed at any other lime of the year (that i can perceive),
nor any other way at that time to be perceived darling up
elsewhere. And I believe it hath been, and will be con-
stantly visiWe at that time of the year. But what the
cause of it in nature should be, I cannot yet imagine, but
leave it to further inquiry." — Childrey, Britannia Baconica,
IfiOl, p. 183. This is the first and simple account of the
phenomenon, Cassini, D6couverte de la himiere celeste qui
parolt dans le zodiaque, in the Mem. de I'Acad. t. viii. 1730,
p. 2r6. Mairan, Trait6 phys. de I'Aurore bort-ale, 1754, p.
16. In the curious book of Childrey, quoted above, there
are very rational views of the epochs of the occurrence of
the maxima and minima in the distribution of the annual
heat, as well as on the course of the daily temperature ;
and on the retardation of the extreme effects in meteorolo-
gical processes. Unfortunately the Baconian philosophi-
sing Chaplain to Lord Henry Somerset, like Bernardin de
St. Pierre, teaches that the earth is pointed at the poles.
Originally he says it was glolmlar, but the ceaseless accu-
mulation of ice at the poles altered the figure of the body
of the earth ; and as ice is formed from water, so does the
quantity of water go on decreasing everywhere else.

62 (p. 44,) — Dominic Cassini (M^m. de I'Acad. t. viii.
1730, p. 188), and Mairan (Aurore bor. p. 16) even main-
tained that the phenomenon seen in Persia, in 1668, waa
the zodiacal light. Delambre (Hist, de I'Astronomie mo-
derne, t. ii. p, 742) ascribes the discovery of this light defin-
itively to the traveller Chardin ; but both in his Couronne-
ment de Soliman and in many passages of his travels (ed.
de Langles, t. iv. p. 326 ; t. x. p. 97) Chardin refers the
Persian niazouk (nyzek), ou petite lance, only to " la grandc
et fameuse com^te qui parut presque par toule la terre en
1668, et dont la t^te etoit cach<ie dans I'occident, de sorte
qu'on ne pouvoit en rien apercevoirsur I'horizon d'Ispahan.'*
(Atlas du Voyage de Chardin, tab. iv.), from observations
at Schiraz. But the head or nucleus of this comet was
seen in Brazil and in India (Pingr6, Cometographie, t. ii.
p. 22). On the conjectured identity of the last great comet
of 1843 with that which Cassini mistook for the zodiacal
light, see Schura. Astron. Nachr. 1843, No. 476 and 480.
In the Persian, the words nizehi ateschin (fiery spears or
lances) are also used for the beams of the rising or setting
sun ; nayizik, in Freytag's Arabic Lexicon, is interpreted
stellae cadentes. The comparis(m of comets with lances and
spears was, however, extremely common in all languages
in the middle ages. Even the great comet which was seen
from April to June, 1500, is always spoken of by Italian
writers of the time under the title of "il Signor Astone
(vide my Exam. crit. de I'Hist. de la Geographic, t. v. p.
80). The statement variously made that Descartes (Cassi-
ni, p. 230, Mairan, p. 16) and Kepler (Delambre, t..i.p.
601) were acquainted with the zodiacal light appears to me
altogether untenable. Descartes (Principes, iii. art. 136,
137) speaks in a very obscure manner of the production of
comets' tails : " Par des rayons obliques qui, tombant sur
diverses parties des orbes plan^taires, viennent des parties
lat6rales 4 notre oeil par une refraction extraordinaire ;"
also how comets' tails can be seen morning and evening,
♦' comme une longue poutre," if the sun be placed between
the comet and the earth. This passage refers to the zodi-
acal light as little as the one in Kepler, in which he speaks
of the existence of an atmosphere about the sun (limbus
circa solem, coma lucida), which in total eclioses of the sun -

116

NOTES TO PRECEDING SECTION.

ht&ders " that it become entirely night." Still more uncer-
tain, or rather more erroneous, is the assertion that the
"trabes quas 6okovs vocant'' (Plin. ii. 22 and 27) was ap-
plied to the ascending tongue-shaped zodiacal light as Cas-
(iini (p. 231) and Mairan (p. 15) will have it. Everywhere
with the ancients the word "trabes" is taken as synony-
mous with fire-balls and fiery-meteors generally, and even
occasionally with streaming comets. On Sokos, Sokios, 6o-
KiTVi, vide Schafer, Schol. Par. ad Apoll. llhod. 1813, t.-ii.
p. 206 ; Pseudo-Aristot. de Mundo, 2, 9 ; Comment. Alex.,
Joh. Philop. et Olymp. in Aristot. Meteor, lib. i. cap. vii. 3,
p. 195, Ideler; Seneca, Nat. Quaest. i. 1.

63 (p. 44.) — Humboldt, Monumens des peuples indigenes
de l'Am6rique, t. ii. p. 301. The rare MS. which belonged
to the Archbishop of Rheims, Le Tellier, contains very va-
rious extracts from an Aztekian ritual book, from an astro-
logical calendar, and from histoi-ical annals from 1197 to
1549. The last include natural phenomena — dates of earth-
quakes, comets— as of 1490, 1592, and, for Mexican chronol-
ogy, important eclipses of the sun. In the MS. Historia de
Tlascala of Camargo, the light which appeared in the east
and rose almost to the zenith is spoken of as "sparkling,
and as if thickly sown over with stars." The account of
the 40 days' phenomenon (Prescott, Hist, of the Conquest
of Mexico, vol. i. p. 284) will by no means apply to an erup-
tion of Popocatepetl which rises close by in the south-east.
Later commentators have confounded this phenomenon,
which Montezuma regarded as one foreboding him misfor-
tune, to the " estrella que humeavu" (properly which spar-
kled ; Mexican choloa, to leap, to sparkle). On the con-
nection of this vapour with the star Ciilal Choloha (Venus)
and the starry mountain (Citaltepetl, the volcano of Oriza-
ba), see my Monumens, t. ii. p. 303.

64 (p. 44.) — Laplace, Expos, du Syst. du Monde, p. 270 ;
M6canique celeste, t. ii. p. 169 and 171. Schubert, Astr.
Bd. iii. 0 206.

65 (p. 44.) — Arago, in Annuaire, 1842, p. 408. See Sir
John Herschel's Considerations on the Volume and Light
of the Planetary Nebulie, in Mary Somerville's Connexion
of the Physical Sciences, 1835, p. 108. The opinion that
the sun is a nebulous star, whose atmosphere has the rip-
pearance of the zodiacal light, was not advanced by Cassini,
but by Mairan, 1731. — {Vide Trait6 de I'Aurore bor. p. 47
and 263. Arago, in Annuaire, 1842, p. 412.) It was a re-
vival of the views of Kepler.

66 (p. 45.) — Cassini, as well as Laplace, Schubert and
Poisson after him, adopted the hypothesis of a detached
ring as an explanation of the figure of the zodiacal light.
He says expressly: " Si les orbites'de Mercure et de Venus
6toient visibles (mat6riellement dans toute I'fetendue de
leur surface), nous les verrions habituellement de la m^me
figure et dans la mfeme disposition A regard du Soleil et
aux m^mes terns de l'ann6e que la lumiere zodiacale." —
(M^m. de I'Acad. t. viii. 1730, p. 218, and Biot, in the
Comptes rendus, 1836, t. iii. p. 666.) Cassini believed that
the vaporiform ring of the zodiacal light was composed of
an innumerable host of small planetary bodies, which re-
volve about the sun. He was himself not indisposed to be-
lieve that the fall of fire-balls might be connected with the
passage of the earth through the zodiacal nebulous ring.
Olmsted, and especially Biot (1. c. p. 673), have endeav-
oured to demonstrate this connection with the November
phenomenon ; any such connection, however, is doubted by
Olbers (Schum. "Jahrb. 1837, p. 281). On the question
whether the plane of the zodiacal light perfectly agrees
with the plane of the sun's equator, wide Houzeau, in Schum.
Astr, Nachr. 1843, No. 492, p. 190.

67 (p. 45.)— Sir John Herschel, Astron. « 487.

68 (p. 45.) — Arago im Annuaire, 1832, p. 246. — Many
physical facts appear to indicate that, with a mechanical
division of matter into its minutest particles, when the mass
becomes extremely small in comparison with the surface,
the electrical tension may arise to the point of producing
luminous and calorific rays. Experiments with a large
concave mirror have not yet given any decisive indications
of the existence of radiating heat in the zodiacal light. —
(Lettre de Mr. Matthiessen k Mr. Arago, in the Comptes
rendus, t. xvi. 1843, Avril, p. 687.)

69 (p. 45.)— "What you tell me of the variations in the
light of the zodiacal light, and their causes within the trop-
ics, has interested me by so much the more, as I have for a
long time every spring given particular attention to the
phenomenon in our northern latitudes. I have myself al-
ways believed that the zodiacal light rotates, but I conclu-
ded that it extended with constantly increasing intensity of
lustre quite to the sun (in opposition to Poisson's view,
which you communicate to me). The luminous ring, which
shows itself about the sun under a total eclipse, I have re-
garded as constituted by this most brilliant portion of the
zodiacal light. I have persuaded myself that this light is
very different in different years ; that for several years in
succession it is extremely bright and extensive ; in others,
again, that it is not even to be seen. I fancy I can see the first
indications of a recognition of the zodiacal light in a letter

, from Rothmann to Tycho, when he says, that in the spriltf.

, he had found the sun 24° below the horizon at the end of
the evening twilight. Rothmann must certainly have con-
founded the disappearance of the sinking zodiacal light, in
the vapours of the evening horizon, with the actual end of
the evening twilight. I have not myself observed any ri-
sings and fallings, probably by reason of the weakness with
which the zodiacal light appears in our latitudes. But you
are assuredly correct when you ascribe such sudden altera-
tions in the light of the heavenly bodies, which you ob-
served within the tropics, to our atmosphere, especially to
changes in its higher regions. This is especially shown in
the tails of great comets. One frequently sees, especially
in clear weather, pulsations in these tails, which begin from
the head of the comet as the lowest point, and tremble
through the entire length of the tail in 1 or 2 seconds, when
the tail appears to be lengthened and immediately after-
wards to be shortened by several degrees. That those
pulsations, to which Hooke and Schrocter and Chladni paid
particular attention, do not take place in the comets' tails
themselves, but are produced by our atmosphere, becomes
obvious when we reflect that the several portions of the tail
(several millions of miles in length) lie at very different dis-
tances from us, and tliat its light can only reach us at in-
tervals of time, several minutes apart from one another.
Whether what you observed on the Orinoco, not at intervals
of seconds, but of minutes, were true corruscations of the
zodiacal light, or belonged wholly and solely to the upper
strata of our light-circle, I will not pretend to determine.
Neither do I know how the remarkable Inminousness of en-
tire nights, and the anomalous increase and protraction of
the twilight in the year 1831, are to be explained, espe-
cially as It was observed that the brightest parts in these
extraordinary twilights did not correspond with the sun's
place below the horizon." — From a letter of Dr. Olbers to
me, dated Bremen, 26th March, 1833.

70 (p. 45.) — Biot, Traite d'Astron. physique, 3me 6d.,
1841, t. i. p. 171, 238. and 312.

71 (p. 45.) — Bessel, in Schum. Jahrb. fiir 1839, S. 51 ;
probably one million of milrs daily ; in relative velocity,
834.000 miles ; and therefore more than twice the velocity
of the earth in its orbit round the sun.

72 (p. 46.) — On the Motion of the Solar System, after
Bradley, Tobias, Mayer, Lambert, Lalande, and William
Hersc\vel, see Arago, in Annuaire, 1842. p. 388—399; Ar-
gelander, in Schum. Astron. Nachr. Nr. 363, 364, 398; and
in the treatise : Von der eigenen Bewegung des Sonnensys-
tems, 1&37, S. 43, on Perseus as the central constellation
of the eniire stratum of stars. See also Otho Slruve, in
Bull, de I'Acad. de St. Petersb. 1842, t. x. No. 9, p. 137—
139 ; according- to whom, from a subsequent combination,
the direction of the sun's motion was found to be 261° 23'
R. A. -j- 37° 36' Decl. ; and, as a mean from Argelander'a
and his own labours, from a combination of 797 stars, 2590
9' R. A. -f 340 36' L..clination.

73 (p. 46.)-Aristot. (^ Ccelo, iii. 2, p. 301 ; Bekker, Phya.
viii. 5, p. 256.

74 (p. 46.)— Sa vary, in th» Connaissance des Tems, 1830,
p. 56 and 163 ; Encke, Berl. Jahrb. 1832, S. 253 ; Arago. m
Annuaire, 1834, p. 260, 295 ; JcHn Herschel, m Mem. of the
Astronom. Soc. vol. v. p. 171.

75 (p. 46.)— Bessel, Untersuchun^desTheils der plane ta-
rischen Storungen, welche aus der Bewegung der Sonnn
entstehen, in Abh. der Berl. Akad. aer Wissensch. 1824
(Mathem. Classe), S. 2—6. The question was opened up
by Johann Tohias Mayer, in Comment. Soc. Reg. Gutting.
1804—1808, vol. xvi. p. 31—68.

76 (p. 47.) — Philos. Transact, for 1803, p. 5.25 ; Arago, in
Annuaire, 1842, p. 375. If the reader would Win a more
tangible idea of the distance of the fixed stars referred to
some short way before in the text, let him suppose the
earth to he at the distance of one foot from the sun, Uranus
would then be 19 feet, and Vega in Lyra 34^ Gerrni.n geo-
graphical (158-6 English) viiles from that luminary.

77 (p. 47.)— Bessel, in Schum. Jahrbuche, 1839, S. 5a.

78 (p. 47.) — MSdler, Astr. S. 476 ; Derselbe, in Schum.
Jahrb. 1839, S. 95.

79 (p. 47.) — Sir William Herschel, in the Philos. Trans-
act, for 1817, Pt. ii. p. 328.

80 (p. 47.)— Arago, in Annuaire, 1842, p. 459.

81 (p. 47.)— Sir John Herschel, in a letter from Feldhuy-
sen of the 13th Jan. !83G ; Nicholl, Archit. of the Heavens,
1838, p. 22. See also some observations of Sir William
Herschel on the great starless space which, at a vast dis-
tance, separates us from the milky way, in the Philos.
Trans, for 1817, Part ii. p. 328.

83 (p. 47.) — Sir John Herschel. Astron. H24 ; and farther
in Observations on Nebulse and Clusters of Stars (Phi).
Trans. 1833, Pt. ii. p. 479, fig. 25) : " we have here a broth-
er system, bearing a real physical resemblance and strong
analogy of structure to our own."

83 (p. 48.)— Sir William Herschel, in the Transact, for
1785, Pt. i. p. 257 ; Sir John Herschel, Astr. § 616 (" the
nebulous region of the heavens forms a nebulous milky way

NOTES TO PRECEDING SECTION.

117

composed of distinct nebulte as the other of stars"), and far-
ther in his letter to me of March 1829.

84 (p. 48.)— Sir John Herschcl, Astron. ^ 585.

86 (p. 48.)-Araffo, in Annuaire, 1842, p. 282—285, 409—
411, and 439—442.

86 (p. 48.)— Olbers on the Transparency of Universal
Space, in Bode's Jahrbuch, 1826, s. 110—121.

87 (p. 48.)—" An opening in the heavens." Sir William
Ilerschel, in the Transact, for 1785, vol. Ixiv. Pt. i. p. 256 ;
Le Francais Lalande, in the Connaissance des terns pour
I'an viii. p. 383 ; Arago, in Annuaire, 1842, p. 425.

88 (p. 48.)— Aristot. Meteor, ii. 5, 1 ; Seneca, Natur.
Quaest. i. 14, 2 ; " coelum discessisse," in Cic. de Divin. i. 43.

89 (p. 48.) — Arago, in Annuaire, 1842, p. 429.

90 (p. 48 ) — In December 1837 Sir John Herschel saw the
star t] Argo, which had hitherto appeared of the second mag-
nitude, and quite unchanging, increase rapidly to the first
niagnitude. In January 1838 the intensity of its light was
still equal to that of a Centauri. According to the latest in-
telligence, Maclear, in March 1843, found the star as brill-
iant as Canopus : a Cruris appeared quite misty beside rj
Argo.

91 (p. 48.) — ** Hence it follows that the rays of light of the
remotest nebuliE must have been almost tw^o millions of
years on their way, and that, consequently, so many years
ago this object must have had an existence in the sidereal
heaven, in order to send out those rays by which we now
perceive it." William Herschel, in the Transact, for 1802,
p. 498; John Herschel, Astr. ^ 590; Arugo, in Annuaire,
1842, p. 334, 359, and 382-385.

92 (p. 49.) — From a beautiful sonnet of my brother, Frei-
heit und Gesetz (Wilhelm von Humboldt, Gesammelte
Weike, Bd. iv. S. 358, No. 25).

93 (p. 49.)— Otfried Muller, Prolegomena, S. 373.

94 (p. 50.) — It is proper to distinguish between the abso-
lute depth to which man has penetrated in his mining opera-
tions, or the depth from the surface of the earth at the place
where the operations are carried on, and the relative depth,
i. e. the depth below the level of the sea. The greatest rel-
ative depth that has been reached is, perhaps, the bore at
New-Salzwerk, Minden, in Prussia. In June 1844 it was
exactly 1844A Parisian feet ; the absolute depth was, how-
ever, 2094^ Par. feet. The temperature of the water in the
deepest bore was 32 7° C. (90 8° F.) which, assuming 9 60 C.
as the mean temperature of the air, gives a rise of 1-60 for
296 metres (upwards of 97*6 feet English). The Artesian
well of Crenelle, at Paris, is only 1683 feet in absolute
depth. From the accounts of the missionary Imbert from
China, the depth of our Artesian wells is far surpassed by
that of the fire-spring Ho-tsing, which yields inflammable
gas employed in salt boiling. In the Chinese province Szii-
tschuan, these fire-springs are said very commonly to reach
a depth of from 1800 to 2000 feet; and at Tseu-lieu-tsing
(place of perpetual flax), a Ho-tsing, bored with the rod in
the year 1812, is reported to extend to the depth of 3000
feet (Humboldt, Asie centrale, t. ii. p. 521 and 525 ; An-
nates de 1' Association de la Propagation de la Foi, 1829, No.
16, p. 369). The relative depth attained at Monte Massi,
in Tuscany, south from Volterra, according to Matteucci, is
but 1 175 feet. The bore at New-Salzwerk approaches very
nearly in relative depth the coal pit at Apendale, New-cas-
tle-under-Lyme (Staffordshire). There the works are car-
ried on 725 yards, or 2045 French feet, under the surface
(Th. Smith, The Miner's Guide, 1836, p. 160). Unfortu-
nately, the height of the ground above the level of the sea
is not accurately ascertained. The relative depth of the
Monkwearmouth pit, near Newcastle-on-Tyne, is only 1404
feet (PhiUijis, Philos. Mag. vol. v. 1834, p. 446) ; that of
the Esperance pit, at Liege, 1271 ; and that of the lately-
worked pit Marihaye, at Val-St.-Lambert, is 1 157 feet. The
greatest absolute depths to which man has penetrated are
in mines, that are either among lofty mountains or in mount-
ain-valleys so much raised above the sea-level that this has
either not been reached at all or has only been surpassed by
a very small quantity.

The Eselschacht at Kuttenberg, Bohemia, before it was
abondoned, had reached the enormous depth of 3545 feet
(Schmidt, Berggesetze, Bd. i. S. 32). At St.-Daniel, and
at Geist, on the Rohrerbiihel, the works, in the 16th centu-
ry, were 2916 feet deep. A drawing of these workings of
the year 1539 is still preserved. Joseph von Sperges, Ty-
roler Bergwerksgeschichte, S. 121. See also Humboldt,
Gutachten iiber Hei-antreibung des Meissner Stollens in die
Freiberger Erzrevier, published in Herder iiber den jetzt be-
gonnenen Erbstollen, 1838, S. 124.) It may be imagined
that information of the extraordinary depth of the workings
at Rohrerbiihel had reached England at an early period, for
in Gilbert's work, De Magnete, I find the statement that
roan had penetrated from 2400 to 3000 feet into the bowels
of the earth : " Exigua videtur terrae portio, quae unquam
hominibus spectanda emerget aut eruitur : cum profundius
in ejus viscera, ultra eflorescentisextremitatiscorruptelam,
aut propter aquas in magnis fodinis, tanquam per venas sca-
tarientes, aut propter agris salubrioris ad vitam operariorum

sustinendam ncccssarii defectum, aut propter ingentea
sumptus ad tantos labores exantlandos, multasque difficul-
tates, ad profundiores terrae i)urtes penetrare non possumus ;
adeo ut quadringentus aut t<luod rarissime] quingentas or-
gyasinquibusdam nietallis, descendisse, stupendus omnibus
videaturconatu.s" (Gulielmi Gilberti, Colcestrensis, de Mag-
nete Physiologia nova, Lond. 1600, p. 40).

The absolute depth of the mines in the Saxon Erzgebirge
are 1824 and 1714 feet ; the relative depths of these respect-
ively are only 626 and 260 feet. The absolute depth of the
rich workings in Joachimsthal, Bohemia, is 1919 feet ; but
taking the height of the surface upon Dechen's estimate at
2250 feet above the level of the sea, it is obvious that there
the sea-level has not even been attained. In the Harz, the
workings in the Samson pit, at Andreasberg, are carried on
at the absolute depth of 2062 feet. In Old Spanish Amer-
ica I know of no deeper mines than those of Valenciana,
near Guanaxuato, Mexico : I found the Planes de San Ber-
nard 1582 feet deep ; but this mine does not reach the level
of the sea by 5592 feet. If we compare the depth of the old
Kuttenberg works (a depth which exceeds the height of the
Brocken, and only falls short of that of Etna by 200 feet)
with the heights of the loftiest buildings that have been
reared by man (the Pyramid of Cheops and the Minster at
Strasburg), we find that the mines are to these in the pro-
portion of 8 to 1.

I have thought it important thus to bring together these
data in relation to the absolute and relative depths that have
been reached by man, a subject in connection with which
many errors have been constantly committed, principal-
ly, as it seems, through faulty reductions of the measure-
ments from one standard to another. On proceeding east-
ward from Jerusalem towards the Dead Sea, a prospect is
gained which, according to our present hypsometrical knowl-
edge, is unparalleled on the face of the earth : there, on ap-
proaching the chasm in which the Jordan flows, we advance,
in open day, along beds of rock which, according to Berton's
and Russegger's barometrical levellings, lie 1300 feet in
perpendicular depth below the level of the Mediterranean
Sea (vide Humboldt, Asie Centrale, t. ii. p. 323).

95 (p. 50.) — Bason-shaped curved strata, which dip down
op one hand and rise again at a measurable distance, al-
though not penetrated by mines or shafts, still suffice to give
us accurate information of the constitution of the crust df
the earth at great depths from the surface. I have to thank
the excellent geologist M. von Dechen for the following.
He writes to me : " The depth of the coal measures at
Mont-St.-Gilles, Liege, which, with our friend M. von
Oeyenhausen, I have estimated at 3650 feet below the sur-
face, must lie at the depth of 3250 feet below the sea-level,
inasmuch as Mont-St.-Gilles is certainly not 400 feet high ;
and the coal-bason at Mons lies fully 1750 feet deeper.
These depressions, however, are trifling when compared
with that of the coal strata of the Saar River (Saarl)ruck).
After repeated trials, I have found that the lowest coal strata
known in the country of Duttweiler, near Bettingen, north-
eastward from Saarlouis, dip 19,406 and 20,656 feet under
the level of the sea." This conclusion exceeds by 8000 feet
the estimate which I have given in the text of Cosmos for
the bason of Devonian strata. These Belgian coal measures,
therefore, lie as far below the level of the sea as Chimborazo
rises above it, at a depth where the temperature of the earth
must be 224° C. (435° F.). From the highest summit oi
the Himalaya to the bottom of this bason, containing the
vegetable remains of the primeval world, we have a perpen-
dicular depth of 45,000 feet, i. e. ^-i^ of the semi-diameter
of the earth.

96 (p. 51.)— Plato, Phaedo, p. 97 (Aristot. Metaph. p. 985).
See Hegel, Philosophic der Geschichte, 1840, S. 16.

97 (p. 51.) — Bessel, AUgemeine Betrachtungen iiber Grad-
messungennach astronomisch-geodatischen Arbeiten, at the
end of Bessel und Baeyer's : Gradraessung in Ostpreussen,
S. 427. On the accumulation of matter on the side of the
moon which is turned to us, see farther, Laplace, Expos,
du Syst. du Monde, p. 308.

98 (p. 51.)— Plin. ii. 68; Seneca, Nat. Quaest. Praef. c.
ii. " El Mundo es poco" (the earth is small) writes Colum-
bus from Jamaica to Queen Isabella on the 7th of June,
1503 ; not in the philosophical sense of the two Romans, but
because it seemed politic to him to represent the passage
from Spain as no great matter, in the same way that he
spoke of "seeking the east from the west." Vide my Ex-
amen crit. de i'hist. de la G6ogr. du 15me siecle, t. i. p. 83,
and t. ii. p. 327 ; where I have, at the same time, shown
that the opinion maintained by Delisle, Fr6ret, and Gosse-
lin, according to which the extraordinary diversity in the
estimates of the earth's perimeter among the Greeks is
merely apparent, and depends on diflTerences of the stadia,
was already advanced by Jaime Ferrer, in the year 1495, in
a proposal for the determination of the Papal line of demar-
cation.

99 (p. 52.)— Brewster, Life of Sir Isaac Newton, 1831, p
162 : " The discovery of the spheroidal form of Jupiter by

118

NOTES TO PRECEDING SECTION.

Cassini had probably directed the attention of Newton to
the determination of its cause, and, consequently, to the
investigation of the true figure of the earth." Cassini
stated the oblateness of Jupiter at y*-^ in 1691 (Anc. M6m.
de I'Acad. des Sciences, t. ii. p. 108) ; but we know, through
Lalande (Astronnm. 3me 6d. t. iii. p. 335), that Maralcii pos-
sessed several printed sheets of a Latin work which Cassini
began, "On the Spots of the Planets," from which it is ob-
vious that Cassini was aware of the oblateness of Jupiter
previous to 1666 ; 21 years, therefore, before the appear-
ance of Newton's Principia.

100 (p. 52.) — According to Bessel's iiivestigation of ten
measurements of degrees, in which the error in the French
measurement discovered by Puissant was taken into account
(vide Schumacher, Astron. Nachr. 1841, No. 438, S. 116),
the semi-axis major of the elliptical spheroid of rotation
which comes nearest to the irregular figure of the earth is
3272077-14 toises ; the semi-axis minor is 3261139-33 toises ;
the oblateness, T>^-Q?yTp7 ' ^^® length of the mean degree of
the meridian, SfOl'S-lOg" toises, with an error of + 2-8403
toises ; whence the length of a geographical mile comes
out 3807-23 toises. Earlier estimates of measurements of
degrees vary between ^^ and tj^tj : thus, Walbeck, de
forma et magnitudine telluris in'deniensis arcubus meri-
diani definiendis, makes it ^Tf-^f^ in 1819 ; Ed. Schmidt
(Lehrbuch der mathem. und phys. Geographic, S. 5),
■5^.3-^ in 1829 from seven measurements of degrees. On
flie influence of great differences of latitude upon the polar
flattening, vide Bibliotheque universelle, t. xxxiii. p. 181,
and t. XXXV. p. 56 ; also, Connaissance des tems, 1829, p.
290. From the moon's equation alone, Laplace found, first
(Expos, du Syst. p. 229), from the older tables of Burg
■v^S ; subsequently, from the lunar observations of Burck-
hardt and Bouvard -^^g^.y (M6can. celeste, t. v. p. 13 and
43).

101 (p. 52.) — Pendulum experiments, as general results,
have given, after the great expedition of Sabine (1822 to
1823, from the equator to 80° N. lat.), 7f^\.y ; from Frey-
cinet (excluding the observations of lie de France, Guam,
and Mowi), -o-^.tt ; after Foster, o^g'g-^ ; after Duperrey,
Tj-Jg-.y ; aftef Liitke, v^V-o^' ■A-?^'"^'' these we have the
observations between "Formentcra and Dunkirk (Connais.
des tems, 1816), according to Mathieu, -^rgV-^ ! ^"^ between
Formentcra and Unst Island, according to Biot, tt-s-V-tt- Vi^e
Baily, Report on Pendulum Experiments, in the Memoirs
of the Royal Astronom. Society, vol. vii. p. 96 ; also Bore-
nius, in Bulletin de I'Acad. de St.-P6tersbourg, 1843, t. i.
p. 25.

The first proposal to apply the length of the pendulum
to the determination of mass, and to take the third part of
the seconds pendulum as an universal pes horarius, or
standard measure for all nations, occurs in Huygens' Horo-
logium Oscillatorium, 1673, prop. 25. The same wish was
reiterated anew in a public monument raised under the
equator by La Condamine, Bouguer, and Godin. On the
beautiful marble tablet which I found uninjured in the quon-
dam Jesuits' College at Quito are these words : " Penduli
simplicis aequiiioctialis unius minuti secundi archetypus,
mensurae naturalis exemplar, utinam universalis !" From
what La Condamine says, in his Journal du Voyage a
I'Equateur, 1751, p. 163, of passages unfilled up in the in-
scription, and a slight difference with Bouguer concerning
the numbers, I expected to have found notable differences
between the inscription of the marble tablet and the state-
ment published at Paris. On carefully comparing them,
however, I only found two of any importance — " ex area
graduum 3J" instead of " ex arcu graduum plus quam tri-
um," and for 1742 the year 1745. This last statement is
singular, inasmuch as La Condamine returned to Europe in
Nov. 1744, and Bouguer had preceded him in June, and
Godin in July. The most necessary and useful correction
in the figures of the inscription would be that of the astro-
nomical longitude of the town of Quito (vide my Recueil
d'Obs. Astron. t. ii. p. 319—354). Nonet's latitudes, cut
into the Egyptian monuments, afford a more recent instance
of the danger of all solemn attempts to perpetuate erroneous
or ill-calculated results.

102 (p. 52.)— On the increased intensity of attraction in
the volcanic islands, St. Helena, Ualan, Fernando de No-
ronha. Isle of France, Guaham, Mowi, and Galapagos, with
the exception of the island of Rawak, perhaps in consequence
of their vicinity to the high land of New Guinea, vide
Mathieu in Delambre, Hist, de 1' Astron, au 18me siecle,
p. 701.

103 (p. 52.) — Many observations also show great irregu-
larities in the length of the pendulum, which are ascribed
to local attractions (vide Delambre, Mesure de la M6ridien-
ne, t. iii. p. 548 ; Biot in the M6m. de. 1' Academic des Sci-
ences, t. viii. 1829, p. 18, 23). When we proceed from west

to east in the south of France and Lombardy, we find t]>«
least intensity in the force of gravitation at Bordeaux ; the
intensity increases rapidly in pl-aces situated to the east,
Figeac, Clermont-Ferrand, Milan, and Padua, in which last
city the maximum force is observed. The influence of tho
southern flanks of the Alps is not merely to be ascribed to
the general magnitude of their volume, but as M. Elie de
Beaumont (Recher. sur las R6vol. de la surf, du globe, J 830,
p. 729.) believes, in principal part to the melaphyre and
serpentine which have raised the chain. On the flanks of
Mount Ararat, which with Caucasus lies as it were in tVie
centre of gravity of the old world, consisting of Europe,
Asia, and Africa, Fedorow's careful pendulum experiment*
proclaim not hollows, but dense volcanic masses (Parrot,
Reisp zum Ararat, Bd. ii. S. 143). In the geodetic opera-
tions of Carlini and Plana in Lombardy, diflerences of from
20" to 47"-8 were found between the immediale observa-
tions of latitude and the results of these opersitions. Vide
the examples of Andrate and Mondovi, Milan and Padua,
in the Operations g6od6s. et astron. pour la mesure d'un
arc du parallele moyen, t. ii. p. 347 ; Effemeridi astron. di
Milano, 1842, p. 57. Milan estimated by Borne, as it stands
in the French trigonometrical survey, is in latitude 45° 27'
52" ; whilst immediate astronomical observations make it
450 27' 35". As the perturbations extend far to the south
of the Po towards Parma (Plana, Op6rat. g6od6s. t. ii. p.
847), we may conjecture that even in the constitution of the
soil of the plain, there are causes producing deviations.
Struve has met with the same thing in the flattest parts of
the east of Europe (Schum. Astron. Nachr. No. 164). On
the influence of dense masses which are conceived to lie at
a moderate depth, corresponding with the point of mean el-
evation of the Alps, see the an-alytical expressions (after
Hossard and Rozet) in Comptes rendus, t. xviii. 1844, p.
292, which may be compared with Poisson (Traite de IVI6-
canique, t. 1. p. 282, 2me 6d.) The earliest indications of
the influence of rocks of different kinds on the vibrations of
the pendulum, are those of Dr. Thomas Young (Phil. Trans.
1819, p. 70—96). In the conclusions, from the length of
the pendulum in regard to the curve of the earth, the possi-
bility is not to be overlooked of the crust of the earth having
become consolidated before metallic and dense basaltic
masses, forced from the interior, had approached the surface.

104 (p. 52.)— Laplace, Expos, du Syst. du Monde, p. 231.

105 (p. 52.)— La Caille's pendulum experiments at the
Cape of Good Hope, which were calculated with great care
by Mathieu (Delambre, Hist, de I'Astr. 18me siec. p. 479),
indicate an oblateness of -^^V-T ' ^"* ^''°™ numerous com-
parisons of observations under similar parallels of latitude
in both hemispheres (New Holland and the Maldives com-
pared with Barcelona, New York, and Dunkirk), there are
no grounds for estimating the mean oblateness of the south
pole as greater than that of the north pole (Biot, in Mem.
de I'Acad. des Sciences, t. viii. 1829, p. 39—41).

106 (p. 53.)— The three methods of conducting the obser-
vations, give the following results: 1st. From deflection of
the plumb-line in the neighbourhood of Shehallien in Perth-
shire, 4-713 by Maskelyne, Hutton, and Playfair (1774—
1776 and 1810) according to a method already proposed by
Newton ; 2d. From vibrations of the pendulum on mount-
ains, 4-837 (Carlini's observations on Mont Cenis compared
with Biot's observation at Bordeaux, Effemer. astr. di Mi-
lano, 1824, p. 184) : 3rd. From the torsion balance of Cav-
endish, after an apparatus originally imagined by Mitchell,
5-48 (from Hutton's revision of the calculation 5-32, and
from Ed. Schmidt's revision 5'52 : Lehrb. des mathem.
Geographaphie, Bd. i. S. 487) ; from the torsion balance of
Reich, 5-44. In the cnlculatiou of this experiment carried
through, in a most masterly manner by Prof. Reich, the
original mean result was 5-43 (with a probable error of but
00233) ; a result which, increased by the quantity by which
the centrifugal force of the earth diminishes the force of
gravitation, for the latitude of Freiburg (50° 55 ), must be
changed unto 5-44. The employment of masses of cast-iron
instead of lead gave no difference of result that might not
safely be ascribed to error of observation ; there was no ev-
idence of magnetic attraction (Reich. Versuche iiber die
mittlere Dichiigkeit der Erde, 1838, S. 60, 62, and 66). By
the assumption of too srN-all a degree of oblateness of the
earth, and the uncertain estimate of the density of the rocks
composing its surface, a mean density of the earth was come
to, as in the experiments on mountains, which was by ^ too
small, viz., 4-761 (Laplace, M6can. c61. t. v. p. 46) or 4,785
(Eduard Schmidt, Lehrb. der. math. Geogr. Bd. i. () 387
and 418). On the hypothesis of Halley, on the earth as a
hollow sphere — the germ of Franklin's idea of earthquakes,
vide Phil. Transact, 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 held it more
worthy of the Creator " that the earth, like a house of sev-
eral stories, should be inhabited both within and without.
For light in the hollow sphere (p. 576) provision could also
be made in a certain way."

NOTES TO PRECEDING SECTION.

119

107 (p. 53.)— Here belong the admirable analytical la-
hours of Fourier, Biot, Laplace, Poisson, Duhainel, and
Lam6. In his work. Tln'orie mafh6mati(iue de la Chaleur,
1835, p. 3, 428—430, 436, and 521—524 (see also the
abstract of La Rive, in the Bibliotheque uuiversello de
Geneve, t. Ix. p. 415), Poisson has developed an hypoth-
esis totally different from the view advocated by Fou-
rier (The<irie. analyt. de la Chaleur). lie denies the
present fluid state of the centre of the earth ; he believes
"that in cooling by radiation to the medium surrounding
the earth, the parts fuse consolidated on the surface sank
downwards, and that by a double upward and downward
current, the great inequality was lessened which would
have taken place in a solid body cooling from the surface."
The great geometrician thinks it more probable that the
consolidation commenced in the parts lying nearer to the
centre ; " the phenomenon of the increase of heat with the
depth does not extend to the whole mass of the earth, and
is a mere consequence of the motion of our planet in uni-
versal space, the several parts of which, by reason of their
stellar heat (chaleur stellaire) have very different tempera-
tures." The heat of the water of our Artesian wells, ac-
cording to Poisson, is therefore heat which has penetrated
the body of the earth from without ; the earth may be
viewed as we should a mass of rock transported from the
equator to the pole in so short a time, that it could not cool
completely. The increase of temperature in this block
would not extend completely to its centre. The physical
doubts which may reasonably be raised against this extraor-
dinary cosmical hypothesis, (an hypothesis which ascribes
to heavenly space what must much rather belong to matter
in its first transition from the gaseous to the solid state)
may be found collected iu Poggendorff's Annalen, Bd. xxxix.
8. 93— KtO.

108 (p. 54.)— See above, pages 9, 15, and 16. The in-
crease in temperature is found in the Puits de Greneille
from 98'4 feet ; in the bore of New-Salzwerk, Minden, al-
most 91 feet ; at Pr^gny, Geneva, also 91 feet, although
there the outlet is 1510 feet above the level of the sea.
This agreement of results, from bores that are severally
1683, 2094, and 680 feet in absolute depth, by a method first
suggested in 1821 by Arago, (Annuaire, 1835, p. 234) is
very striking. The two points of the earth at a short per-
pendicular distance from one another, whose annual tem-
perature is ascertained with the greatest precision, are
probably the external atmosphere of the Observatory of
Paris and of the cellar under the Observatory. The former
is 10O-822, the latter 110-834 C. ; difference 1O012 C. for
86 feet of depth (Poisson, Th6orie, &c., p. 415 and 462).
lu the course of the last 17 years, from causes which have
not been ascertained, the thermometer of the Caves has
risen 0O220 C. If the penetration of waters from lateral
channels into the main bore of Artesian wells produces some
disturbance, it must be admitted that in reference to mines
there are many more perturbing causes at work, and that
interfere with the accuracy of conclusions in reference to
their temperature at different depths. The general result
of Reich's great work on the temperature of the mines of
the Saxon Erzgebirge is the somewhat slow increase of 1°
C. for 128^ feet of descent. (Reich, Beob. iiber die Temper-
ature des Gesteins in verschiedenen Tiefen, 1834, S. 134.)
Yet Phillips (Poggend. Ann. B. 34, S. 191), in a shaft of the
Monkwearmouth coal-pit, found an increase of 1° C. for
Q9-~^ feet of descent, exactly what Arago found in the Puits
de Greuelle.

109 (p. 54.) — Bous-singault sur la Profondeur 4 laquelle
se trouve la Couche de Temperature invariable entre les
tropiques, in the Annales de L'himie et de Physique, t. liii.
1833, p. 225—247.

110 (p. 55.)— Laplace, Exp. du Syst. du Monde, p. 229 and
263 ; Mecanique c61. t. v. p. 18 and 72. It is to be ob-
served that the fraction y^^ of a centigrade degree of a
mercurial thermometer, which is given in the text as the
limit of stability of the heat of the earth since Hippar-
chus's time, rests on the assumption that the dilatation of
the materials of which the body of the earth consists is the
same as that of glass = -^^L.-_ for 1° C. of heat. Vide
on this point Arago, in Annuaire pour 1834, p. 177 — 190.

111 (p. 55.)— William Gilbert of Colchester, whom Gal-
ileo calls " great to a degree that might excite envy," says,
'• Magnus magnes ipse est globus terrestris." He ridicules
the magnetic mountain of Fracastoro, the great contempo-
rary of Christopher Columbus, as the magnetic pole : " Re-
jicienda est vulgaris opinio de moiitibus magneticis, aut
rupe aliqua magnetica, aut polo phautastico a polo mundi
distanle." lie assumes the variation of the magnetic needle
over the surface of the earth as unchanging: " Variatio
uniuscujusque loci constans est ;" and explains the isogonic
lines from the configuration of continents and the relative
position of the sea basin, which has a weaker magnetic at-
tractive force than the solid masses that rise above the
ocean (Gilbert de Magnete, ed 1633, p. 42, &c.)

H2 (p. 55.)— Gauss, Allgemeiue Theorie des Erdmag-

nctismus, in den Resultaten aus den Beob. des magnet.
Vereins im Jahr. 1838, « 41, S. 56.

113 (p. 55.)— There are also pcrturhationx which do not
extend to any distance, which are more local, and perhaps
have their seat less deeply. A rare example of such extra-
ordinary perturbations, which aie felt in the Freiburg mines
and not in Berlin, was published by me now many years
ago (Lettre dc M. de Humboldt 4 S. A. R. le Due de Sussex
sur les moyens propres i perfectionner la connaissance du
Magn6tismeterrestre, in Becquerel'sTraite experimental de
TElectricite, t. vii. p. 442). Magnetic storms that were ex-
perienced simultaneously from Sicily to Upsal, did not ex-
tend from Upsal to Altona (Gauss and Weber, Resullate
des magnet. Vereins, 1839, s. 128; Llovd, in the Comptes
rendus de rAcademic des Sciences, t. x'iii. 1843, S6m. ii. p.
725 and 827). Among the many perturbations which in
recent times have been observed simultaneously over ex-
tensive districts of country, and which are collected in Sa-
bine's important work (Observ. on days of unusual magnetic
disturbance, 1843), one of the most remarkable is that of
the 25th September, 1841, which was noticed at Toronto in
Canada, at the Cape of Good Hope, at Prague, and partially
in Van Diemeu's Land. The English Sunday, on which it
is sinful after Saturday night at 12 o'clock to read off a
scale, and to follow the grand phenomena of nature in their
course, intervening, broke off the observations in Van Die-
men's Land, and so made our information on this remarkable
storm incomplete !

114 (p. 55.) — The application of the magnetic inclination
to the determination of the latitude along a coast running
north and south, and which, like the shores of Chili and
Peru, is enveloped in fog (garua) for a portion of the year,
I published in Lam6therie's Journal de Physique, 1804, t.
lix. p. 449. The application in the locality indicated is the
more important, as, in consequence of the rapid current
from south to north as far as Cape Parisia, it occasions a
great loss of time to the shipping when the coast has to b«
first approached northward from the destined port. In the
South Sea, from Callao de Lima harbour to Truxillo, with
a difference of 3° 57' of latitude, I have observed a variation
of the needle of 9° C. ; and from Callao to Guayaquil, with
a difference of 9° 50' of latitude, a variation of 2305° (vide
my Relat. Hist. t. iii. p. 622). From Guarmey (10° 4' S.
lat.), Huaura (11° 3' S. lat.) to Chancay (11° 32' S. lat.),
the inclinations were 6-60O, 900°, and 10-35°. The deter-
mination of places by means of the magnetic inclination had
this remarkable feature about it, that where the ship's
course cuts the isoclinal lines almost perpendicularly, it is
the only one that is independent of all determination of
time, and so of the sight of the sun and other heavenly bod-
ies. 1 very lately, and for the first time, discovered propo-
sals to determine the latitude by the inclination of the
magnetic needle in Gilbert's work, De Magnete (lib. v. cap,
8, p. 200). This was scarcely 20 jears after the discovery
of magnetic inclination by Robert Norman. Gilbert even
points to the method as available "acre caliginoso ;" and
Wright, in the preface which he has added to the great
work of his teacher, speaks of such a proposal as '* worth
much gold." As he, with Gilbert, presumed erroneously
that the isoclinal magnetic lines ran parallel with the geo-
graphical circles of latitude, as also that the magnetic equa-
tor coincided with the geographical equinoctial line, he did
not perceive that the proposed method was only capable of
a local and much more limited application than that he im-
agined.

115 (p. 55.) — Gauss and Weber, Resultate des magnet-
ischen Vereins in J. 1838, (f 31, s. 46.

116 (p 55.)— According to Faraday (Loudon and Edin-
burgh Philosophical .Magazine, 1836, vol. viii. p. 178), pure
cobalt is totally without magnetic power. Rose and Wohl-
er, again, do not admit this as absolutely ascertained. If
one of two masses of cobalt (both of which are believed to
be pure) shows itself totally indifferent to magnetism, it
seems to me likely that the other which shows magnetic
properties does so in virtue of some impurity.

117 (p. 55.) — Arago, in the Annales de Chimie, torn, xixii.
p. 214 ; Brewster, Treatise on Magnetism, 1837, p. Ill ;
Baumgartner, in the Zeitschrift fur Phys. und Mathem.
Bd. ii. s. 419.

118 (p. 55.)— Humboldt, Examen critique de I'hist. de la
Geographic, tom. iii. p. 36.

119 (p. 55.) — Asie centrale, tom. i. Introduction, p.
xxxvii— xlii. The western nations, the Greeks and the Ro-
mans, knew that magnetism could be communicated for a
great length of time to iron ("sola haec materia ferri vires
a. magnete lapide accipit retinetque longo tempore" Plin.
xxxiv. 14). The great discovery of the terrestrial directive
force therefore depended alone on this, that no one in the
west happened to observe a longish piece of magnetic iron
ore or a magnetized iron rod, floated at liberty upon water
by means of a piece of wood, or balanced and suspended
freely in the air by means of a thread.

120' (p. 56.) — A very slow secular progression or a local
invariability of the magnetic declination may be of great

120

NOTES TO PRECEDING SECTION.

consequence in connection with the boundaries of property :
•' The whole mass of West India property," says Sir John
Herschel, " has been saved from the bottomless pit of end-
less litigation by the invariability of the magnetic declina-
tion in Jamaica and the surrounding- archipelago during the
whc'le of the last century ; all surve.ys of property there
having- been conducted solely by the compass." Vide Rob-
ertson, in the Phil. Trans, for 1806, pt. ii. p. 348, On the
Permanency of the Compass in Jamaica since 1660. In the
parent country (England) the magnetic declination has va-
ried by 14° in the same period of time.

121 (p. 56.) — I have elsewhere shown that from the docu-
ments which have come down to us in connection with the
voyages of Columbus, we can with great certainty fix upon
three places in the Atlantic line of no variation for the 13th
September, 1492, the 21st May, 1496, and the 16th August,
1498. This line ran at these dates from North-East to
South-West. It touched the American continent some-
what to the east of Cape Codera, whilst at present the con-
junction is obser\'ed on the north coast of Brazil. (Hum-
boldt, Examen critique de I'hist. do la G6ogr. torn. iii. p.
44 — 48.) From Gilbert's Physiologia nova de Magnete, we
see plainly (and this fact is very remarkable) that in the
year 1600 the variation was still nil in the region of the
Azores (lib. iv. cap. 1), precisely as in Columbus's time. I
believe that, from documents in my Examen critique (torn.
iii. p. 54), I have demonstrated that the celebrated line of
demarcation, by means of which Pope Alexander VI. divi-
ded the western hemisphere between Spain and Portugal,
was not drawn through the most western of the Azores, be-
cause Columbus wished to turn a physical division into a
political one. He indeed laid great stress nptm the zone
(raya), "on which the compass showed no variation, where
the air and the ocean, the latter covered with sea-weed,
show themselves differently constituted, where cooling
winds begin to blow, and (for so erroneous observations of
the polar star made him imagine) where the figure (the
sphericity) of the earth is no longer the same."

122 (p. 56.)— It is a question of the highest interest in the
problem of the physical cause of the terrestrial magnetism,
whether the two oval systems of isogonul lines, so singular-
ly included each within itself, will continue to advance for
centuries in the same form, or will resolve themselves and
expand. In the eastern Asiatic coil, the variation increases
from without inwards ; in the coil or oval of the South Sea,
the opposite holds good ; at present, indeed, no line without
variation is known in the whole Southern Ocean-; to the
east of the meridian of Kamtschatka, no line has less varia-
tion than 2° (Erman, in Poggend. An. b. xxi. s. 129). Yet
Cornelius Schoutenappears, on Easter-day of the year 1616,
somewhat to the south of Mukahiva. in 15° S. Lat., 132°
W. Long., in the middle of the present closed isogonal sys-
tem, consequently, to have found the variation nil (Hansteen,
Magnetism, der Erde, 1819, S. 28). It must not be forgot-
ten, that in all these considerations we can only follow the
direction of the magnetic lines in their advances as they
are projected upon the surface of the earth.

123 (p. 56.)— Arago, in Annuaire, 1836, p. 284 : and 1840,
p. 330-338.

124 (p. 56,) — Gauss, Allg. Theorie des Erdmagnetismus,
«31.

125 (p. 56.) — Duperrey, de la configuration de l'6quateur
magn6tique, in the Annales de Chemie, tom. xlv. p. 371
and 379 (see also Morlet, in M6moires pr6sent6s par di-
rers savans A I'Acad. roy. des Sciences, tom. iii. p. 132).

126 (p. 57.) — See the remarkable mass of isoclinal lines
in the Atlantic Ocean for the years 1825 an(i 1837, in Sa-
bine's Contriliutions to Terrestrial Magnetism, 1840, p. 139.

127 (p. 57.) — Humboldt, iiber die seculSre Verfinderung
der magnetischen Inclination, in Poggend. Annalen, Bd.
XV. S. 322. ,

128 (p. 57.) — Gauss, Resultate der Beob. des magn. Ve-
reins im Jahr. 1838, ^ 21 ; Sahine, Report on the Variations
of the Magnetic Intensity, p. 63.

139 (p. 57.) — The following is the history of the discovery
of the law of the (general) increase of intensity in the mag-
netic force with magnetic latitude. When in 1798 I was
anxious to attach myself to the expedition of Captain Bau-
din, fitting out for a voyage round the world, I was request-
ed by Borda, who took a warm interest in my project, in
different latitudes of both hemispheres, to observe the swing
of the vertical needle in the magnetic meridian, with a
yiew to determine whether the intensity of the force was
the same or different in different places. This investiga-
tion I made one of the principal points in the course of my
voyage to the tropical countries of America. I observed
that the same needle which in Paris performed 245, in Ha*
vannah 246, in Mexico 242 oscillations, in the course often
minutes ; at San Carlos, Rio Negro (lOO 53' N. lat.. 8(10 40'
W. long.), in the same interval of time, performed 216 oscil-
lations ; on the magnetic equator, i. e. the line on which
the inclination is = 0, m Peru (7° 1' S. lat., 80° 40' W.
long.), it performed only 211 oscillations; in Lima (120 2'
S. lat.) it again flerforiaed 219 oscillations. 1 found further,

from 1799 to 1803, that the whole force taken at I.OOOO on
the magnetic meridian in the Peruvian Andes, betweea
Micuipamfia ami Caxamarca, at Paris will be represented
by 1,3482 ; in Mexico by 1.3155 ; in San Carlos by 1,0480:
in Lima by 1,0773. When I made known this law of tho
variable intensity of the terrestrial magnetic force, and ad-
duced the numerical value of observations made in 104 dif-
ferent places, in illustration of the conclusions, in a paper
which was read before the Parisian Institute at its sitting
of the 26th Frimaire, An. xiii., and of which the mathe-
matical portion belongs to M. Biot, the subject was regarded
as entirely new. It was only after the reading of this pa-
per, as Biot himself says expressly, (Lam6therie, Journ. da
Physique, t. lix. p. 446, note 2,) and as I repeat the state-
ment in my Relation Historique (t. i. p. 262, note 1), that
M, de Rossel communicated to M. Biot his observations on
oscillation made six years previously in Van Dieman's
Land, Java, and Amboyna ; from these observations was
deduced the same law of declining intensity in the Indiaa
Archipelago. It is almost to be supposed that this excel-
lent man, in his own work, was not aware of the regularity
of the increase and decrease of the intensity, as before the
reading of my paper he never mentioned this certainly not
unimportant physical law to our common friends. La Place,
Delambre, Prony, and Biot. It was only in 1808, four years
after my return from America, that the observations "made
by M. de Rossel were published in the Voyage de I'Entre-
casteaux, t. ii. p. 287, 291, 321, 480, 644. Up to the pres-
ent time it has still been usual in all the tables of magnetio
intensity that have been published in Germany by Hansteen,
Magnet, der Erde 1819, s. 71 ; Gauss, Beob. des magnet. Ve-
reins 1838, S. 36—39 ; Erman, Physikal. Beob. 1841. S. 529 —
579 ; in England (Sabine, Report on Magnet. Intensity, 1838,
p. 43—62 ; Contributions to Terrestrial Magnetism, 1843,)
and in France ^Becquerel, Trait6 d'electr. et de magnet, t.
vii. p. 354 — 367), to reduce the oscillations observed in any
part of the earth to the measure of the force which I found on
the magnetic equator in North Peru ; so that from the unity
thus arbitrarily assumed, the intensity of the magnetic force
at Paris is always set down at 1,348. Still older than the ob-
servations of Admiral Rossel, however, are those that were
made in the unfortunate expedition of La Ptirouse by Lama-
non, during the stay at Teneriffe ( 1785) and to the arrival at
Macao (1787), and which were sent to the Academy of Scien-
ces. It is known for certain that these papers were in the
hands of Condorcet in the July of 1787 (Becquerel, t. vii. p.
320). In spite of searching, however, they have not again
been found ; but from the copy of a letter of Lamanou, now
ill the possession of Ad. Dui)errey, addressed to the then
perpetual secretary of the Academy of Sciences, which has
been omitted in the account of the Voyage of La Perouse,
it is stated expressly, " Que la force attractive de I'aimant
est moindie dans les tropiques qu'en avangant vers les poles,
et que I'lntensite magnetique deduite du nombre des oscil-
lations de I'aiguille de la boussole d'inclinaison change et
augmente avec la latitude." Had the Academy of Sciences,
still anticipating the return of La Perouse, felt itself at lib-
erty, in the course of 1787, to publish an account of obser-
vations made by three different individuals unknown to one
another, the theory of terrestrial magnetism would have
been extended by a new class of observations eighteen years
sooner than it was. This simple statement of facts will
perhaps justify the assertion which the third volume of my
Relation historique (p. 615) contains: "Les observations
sur les variations du magnfetisme terrestre auxquelles je me
suis livre pendant 32 ans, au inoyen d'iiistrumens compar-
ables entre eux en Am6rique, en Europe et en Asie, em-
brassent, dans les deux h«imispheres, depuis les frontieres
de la Dzoungarie chinoise jusque vers I'ouest i la Mer du
Sud qui baigne les cfites du Mexique et du Perou, un es-
pace de 188° de longitude, depuis les 60° de latitude nord
jusqu'aux 12° de latitude sud. J'ai reganie la loi du d6-
croissement des forces magnttiques, du pole a I'fequateur,
comme le r6sultat le plus important de mon voyage Am6ri-
cain." It is not certain, but extremely probable, that Con-
dorcet read the letter of Lamanon of July, 1787, at a meet-
ing of the Academy of Sciences of Paris ; and such a sim-
ple reading I myself regard as a sufficient act of publication
(Annuaire du Bureau des Longit. 1842, p. 463). The first
recognition of the law, therefore, belongs indisputiil)]y to
the companion of La Perouse ; but, long unheeded or forgot-
ten, I believe that the knowledge of the law of the varia-
tion in the intensity of the magnetic force with the latitude,
fir.st acquired' a scientific exi.stence with the publication of
my observations from 1798 to 1804. The subject, and the
length of this note, will not appear indifferent to him who
is familiar with the recent history of magnetism, and the
doubts that have been started in connection with it, and
who from personal experience knows that we are apt to at- ^
tach some value to that which has been the object of our
uninterrupted attention for five long years, under the press-
ure of tropical climates, and engaged in hazardous mountain
expeditions.
130 (p. 57.) — The maximun. intensity for the whole »ur»

NOTES TO PRECEDING SECTION.

121

face of the earth, according to the observations hitherto col-
lected, appears to be 2;052, the minimum 0,706. Both phe-
nomena l)olong to the Southern hemisphere ; the first to 73°
47' S. lat., 1690 30' E. long., near Mount Crozier, West
North-West of the South magnetic pole, at a place where
Sir James Ross found the inclination of the needle 87° 11'
(Sabine, Contributions to Terrestrial Magnetism, 1843, No.
5, p. 231) ; the second, observed by Erman under 90° 59' S.
lat , 370 24' W. long., 80 miles eastward from the coast of
the province of Espiritu Santo, Brazil (Erman Phys. Beob.
1841, S. 570), at a point where the inclination is only 7° 55'.
The accurate relations of the intensity to one another are
therefore as 1 to 2-906. It was long believed that the great-
est intensity of the magnetic force was only two and a half
times as great as the weakest which the surface of our earth
manifests (Sabine, Report on Intensity, p. 82).

131 (p. 57.) — On Amber (succinum, glessum) Pliny says,
xxxvii. 3, "Genera ejus plura. Attritu digitorum accepta
caloris anima trahunt in se paleas ac folia arida quae levia
Bunt, ac ut magnes lapis ferri ramenta quoque." (Plato, in
Timaeo, p. 80 ; Martin, Etudes sur le Timee, t. ii. p. 343—
346 ; Strabo, xv. p. 703, Casaub. ; Clemens Alex. Strom,
ii. p. 370, where, strangely enough, to aovxiov and to t;Xc-
xpov are distinguished.) When Thales, in Aristot. de ani-
ma 1, 2, and Hippias in Diog. Laertio 1, 24, attribute a soul
to the magnet and to amber, this animation only refers to a
moving principle.

132 (p. 57.)—" The magnet attracts iron in the same way
as amber attracts the smallest grains of mustard. It is like
a breath of wind which penetrates through both, and is com-
municated with the rapidity of an arrow." These words
are Kuopho's, a Chinese orator on the magnet, and writer ot
the beginning of the fourth century. (Klaproth, Lettre 4
M.A. de Humboldt, sur I'invention de la boussole, 1834, p.
125.)

133 (p. 58.) — "The phenomenaof periodical variations de-
pend manifestly on the action of solar heat, operating prob-
ably through the medium of thermoelectric currents induced
on the earth's surface. Beyond this rude guess, however,
nothing is as yet known of the physical cause. It is still a
matter of speculation, whether the solar influence be a prin-
cipal or only a subordinate cause in the phenomena of ter-
restrial magnetism." (Observ. to be made in the Antarctic
Exped. 1840, p. 35.)

134 (p. 58.)— Barlow, in the Philos. Transact, for 1822, P.
i., p. 117 ; Sir David Brewster, Treatise on Magnetism, p.
129. Long before Gilbert and Hooke, it was taught in the
Chinese work. Ou-thsa-tsou, that heat lessened the direct-
ive property of the magnet. (Klaproth, Lettre d M. A. de
Humboldt, sur I'invention de la boussole, p. 96.)

135 (p. 58.) — Vide the paper on Terrestrial Magnetism in
the Quart. Review, 1840, vol. Ixvi. p. 271—312.

136 (p. 58.)— As the first demand for the establishment of
these observatories (a net-work of stations provided with
similar instruments) took its rise with me, I dare not cher-
ish the hope that I shall live long enough to see both hemi-
spheres covered in equal and due measure with magnetical
stations, under the control of able naturalists and astrono-
mers, and especially under the liberal and continued support
of the British and Russian governments. In the years 1806
and 1807 at Berlin, with my friend and fellow lal)ourer,
Oltmanns, particularly at the times of the solstices and equi-
noxes, I frequently observed the movements of the needle
from hour to hour, and even from half hour to half hour,
during five or six days and nights in succession. I had per-
suaded myself that continuous, uninterrupted observations
of several days and nights were preferable to the single ob-
servations of many months. The apparatus, a magnetic
telescope by Prony, suspended in a glass case from a thread
without torsifm, enabled angles of 7 and 8 seconds to be
read off upon a finely-divided scale, fixed at a proper dis-
tance and illuminated at night with lamps. Magnetic per-
turbations (storms) which occasionally returned on several
successive nights at the same hours, led me even at that
time to desire most anxiously that similar apparatuses should
be used to the east and west of Berlin, for the sake of dis-
tinguishing general telluric phenomena from those of a lo-
cal nature, and that may depend on perturbations in the un-
equally-healed body of the earth, or in the cloud-forming
atmosphere. My removal to Paris, and the lengthened po-
litical disturbances which spread over the whole of the west
of Europe, prevented my wish from being accomplished at
this time. The light diffused by the great discovery of Or-
«ted (1820), of the intimate connection between electricity
and magnetism, finally aroused the general interest after its
long sleep, in the periodical change of the electro-magnetic
charge of the earth. Arago, who many years before had
begun the longest unbroken series of hourly observations
which we possess in Europe in the observatory of Paris,
with an admirable declination instrument by Gambey, show-
ed, by meaus of simultaneous observations of perturbation
made at Kasan, what advantages resulted from correspond-
ing measurements of variation. When I returned to Berlin,
lifter.^ residence of eighteen years in France, I had a small

magnetic house erected in the autumn of 1828, not only with
a view to carrying out the work begun in 1806, but especial-
ly that simultaneous observations, at hours previously agreed
upon, might bo made at Berlin, Paris, and Freiburg (at a
depth of 35 fathoms under the surface). The simultaneous-
ness of the perturbations, and the parallelism of the move-
ments for October and December, 1829, were there graphi-
cally represented (Poggend. Annal. Bd. xix. S. 357, Tab,
I. — III.). An expedition into the North of Russia, underta-
ken in 1829 by command of the Emperor, gave me an oppor-
tunity of extending my plan upon a great scale. This plan
was unfolded to a committee especially named in one of the
imperial academies of science ; and under the protection of
the chief of the mining corps. Count von Cancrin, and the
excellent superintendence of Prof. Kupffer, magnetic sta-
tions were fixed over the whole of the north of Asia, from
Nicolajeff by Catherinenburg, Barnaul, and Vertschinsk, to
Peking.

The year 1832 (vide Getting, gelehr. Anzeig. St. 206)
marks the great epoch in which the profound author of anew
theory of terrestrial magnetism, Frederick Gauss, erected
apparatus, constructed upon new principles, in the Gottin-
gen Observatory. In 1834 the magnetic observatory was
finished, and in the same year Gauss spread his instruments
and his n^ethod of conducting observations, in which the
distinguished natural philosopher, William Weber, took
great interest, over a large portion of Germany, Sweden,
and Italy (Resultate der Beob. des magnetischen Vereins
im Jahr. 1838, S. 135, and Poggend. Annalen, Bd. xxxiii.
S. 426). In the magnetical association that was now form-
ed, with Goftingen for its centre, at four periods of the year,
ever since 1836, hourly observations for an entire day were
regularly instituted, but which were not those of the equi-
noxes and solstices which I had proposed and followed in
1830. Up to this time. Great Britain, in possession of the
largest commerce in the world, and with her wide-spread
navy, had taken no part in the movement, which, since 1828,
had begun to afford important results towards the determi-
nation of terrestrial magnetism. I was so fortunate, in a
public appeal from Berlin to the Duke of Sussex, then Pres-
ident of the Royal Society, by my letter of April 1836, head-
ed, " Lettre de M. de Humboldt A S. A. R. le Due de Sus-
sex sur les moyens propres a perfectionner la connaissance
du magn6tisme terrestre par l'6tablissement de stations
magn^tiques et d'observations correspondantes," to excite a
lively interest in the undertaking which had so long been
the object of my warmest wishes. In my letter to the Duke
of Sussex I urged the erection of permanent stations in Can-
ada, St. Helena, the Cape of Good Hope, the Isle of France,
Ceylon, and New Holland, all of which I had, however,
pointed out as advantageous positions five years previously.
There was a joint physical and meteorological committee
appointed in the Royal Society, which, besides fixed mag-
netic observatories in both hemispheres, proposed to the
government to fit out a naval expedition for magnetic obser-
vations in the Antarctic Seas. I need not here proclaim all
that science owes in this conjuncture to the zeal and activity
of Sir John Herschel, Col. Sabine, Professor Airy, and Mr.
Lloyd, as well as the powerful support that was giveii by
the British Association for the Advancement of Science as-
sembled at Newcastle in 1838. In June, 1839, the Antarc-
tic expedition, under the command of Captain James Clarke
Ross, was resolved on ; and now, since its fortunate return,
we enjoy the double fruits of important geographical discov-
eries in the neighbourhood of the South Pole, and a series of
simultaneous observations in eight or ten new magnetic sta-
tions.

137 (p. 58.) — Instead of ascribing the internal heat of the
earth to the transition of matter from a state of gaseous fluid-
ity to the solid condition on the fonnation of the planets. Am-
pere has broached what to me appears a very improbable
opinion, viz., that it might be a consequence of an incessant
chemical action of a central mass of earth and alkali-metals
upon the external crust undergoing oxydation. " On ne peut
douter," he says, in his masterly Theorie des ph6nomenes
61ectro-dynamiques (1826, p. 199), " qu'il existe dans l'int6-
rieur du globe des courants electro-magnetiques, et que ces
courants sont la cause de la chaleur qui lui est j)ropre. lis
naissent d'un noyau metallique central compos6des mfetaux
que Sir Humphrey Davy nous a fait connaltre, agissant sur
la couche oxid6e qui entoure le noyau."

138 (p. 58.) — The remarkable connection between the
curvature of magnetic lines and that of my isothermal lines
was first observed by Sir David Brewster (Transactions of
the Royal Society of Edinburgh, vol. ix. 1821, p. 318, and
Treatise on Magnetism, 1837, p. 42, 44, 47, and 268). This
distinguished natural philosopher admits two "poles of
maximum cold" in the northern hemisphere ; one American
(730 N. Lat., 102° W. Long., near Cape Walter) ; another
Asiatic (73° N. lat., 78^ E. Long.) ; whence, according to
him, arise two hot and two cold meridians, i. e. meridians
of greatest heat and greatest cold. In the 16th century,
however, Acosta (Hist. nat. de las Indias, 1589, lib. i. cap.
17), resting what he says on the observations of a highly

122

NOTES TO PRECEDING SECTION.

experienced Portuguese pilot, taught that there were four
lines witliout variation. This view apjiears, if we may
judge from the controversy of Henry Bond (author of the
worlc — The Longitude Found, 1676) with Beckborrow, to
have had some influence upon Halley's Theory of magnetic
poles. Vide my Examen critique de I'hist. de la Geo-
graphic, t. iii. p. 60.

139 (p. 58.)— Halley, in the Philosophical Transactions,
vol. xxix. (for 1714—1716, No. 341).

140 (p. 58.)— Dove, in Poggendorff's Annalen, Bd. xx. S.
341, Bd. xix. S. 388: "The dipping needle comports itself
very nearly as an atmospherical thermometer, whose differ-
ence in like manner shows the increased tension of the
electricity before this has risen to such a height that a
spark is elicited. Vide also the excellent observations of
Prof. Kaemtz, in his Lehrbuch der Meteorologie, Bd. iii. S.
511—519; Sir David Brewster, Treatise on Magnetism, p.
280. On the magnetic properties of the galvanic flame or
luminous bow from a Bunsen's charcoal und zinc battery,
vide Casselmann's Beob. (Marburg, 1814,) S. 56—62.

141 (p. 59.)— Argelander's import^ant observations on the
Northern Lights, embodied in his VortrSge, crehalten in der
physikalisch-okononiischcn Gesellschaft zu K6nigsberg, Bd.
i. 1834, S. 257—264.

143 (p. 59.) — On the results of the observations of Lottin,
Bravais, and Siljerstrom, who passed a winter at Bosekop,
on the coast of Lapland (70° N. Lat.), and in 210 nights
saw 160 Auroras boreales, vide Coniptes rendus de I'Acad.
des Sciences, toni. x. p. 289, and Martin's Met6orologie,
1843, p. 453. See also Argelander, in his Vortrftge, geh.
in der Konigsberg. Gesellschaft, Bd. i. S 259.

1415 (p. 59.) — John Franklin (Narrative of a Joumev to
the Shores of the Polar Sea in the years 1819—1822, p.' 552
and 597; Thieneniann,in Edinburgh Philosophical Journal,
vol. IX. p. 366; Farquharson, ib. vol. vi. p. 392; Wrangel,
Phys. Beob. S. 59 ; Parry, Journal of a Second Voyage,
performed in 1821—1823, p. 156) saw a great Aurora con-
tinue through the day. Something of the same kind was
seen in England, 9th Sept. 1827. At mid-day, a luminous
arch, 20° high, and rays shooting from it, were perceived
after rain, in a part of the heavens that had become clear.
Journal of the Royal Institution of Great Britain, 1828,
Jan., p. 429.

144 (p. 59.) — After my return from my American travels.
I described the cirro-cumulus cloud — when it appears very
regularly divided into rounded masses as if by the agency
of repulsive forces— under the name of polar streaks (bandes
polaires), because their perspective point of convergence is
mostly in the magnetic meridian in the first instance, so
that the parallel rows of cumuli follow the magnetic merid-
ian. One peculiarity of this enigmatical jthenomenon is,
the swaying hither and thither of the point of convergence.
Usually the streaks are only completely developed in one
region of the sky, and in their motion they are seen directed
first from south to north, and then gradually veering round
from east to west. I cannot ascribe the advance of the
zones to any change in the quarter of the wind in the supe-
rior strata of the atmosphere. They arise when the air is
extremely calm and the heaven is particularly serene, and
under the tropics are far more common than in the temper-
ate and frigid zones. I have observed the phenomenon
among the Andes, when I was at the height of 14,000 feet
above the level of the sea, as well as in Northern Asia, in
the plains of Krasnojarski, southward from Buchtarminsk,
and in both instances so much alike, that the natural pro-
cess in virtue of which it takes place must be regarded as
one of very extensive prevalence. See the important ob-
servations of Kaemtz (Vorlesungen iiber Meteorologie, 1840,
S. 146) ; also those of later date, or Martins and Bravais'
M6t6orologie, 1843, p. 117. In an exhibition of south polar
streaks of very delicate clouds, which Arago observed by
day on the 23d of June, 1844, at Paris, dark rays shot up-
wards from .an arch which was directed from east to west.
We have above (p. 59) referred to darker polar lights— to
rays bearing some resemblance to dusky smoke.

145 (p. 60.)— The northern lights are called "the merry
dancers" by the inhabitants of the Shetland Islands. Ken-
dal, in Quarterly .lourn. of Science, new series, vol. iv. p. 395.

146 (p. 60.)— See the admirable work of Muncke, in the
new edition of Gehler's Physik. Worterbuch, Bd. vii. 1,
S. 113—268, particularly S. 156.

147 (p. 60.)— Farquharson, in Edinb. Philos. Journal, vol.
xvi. p. 304 ; Philos. Transact, for 1629, p. 113.

148 (p. 60.)— Kamtz, Lehrb. der Meteorologie, Bd. iii. S.
498. 501.

149 (p. 61.)— Arago on the dry fog of 1783 and 1831, which
illuminated the night, in Annuaire for 1842 ; and on extra-
ordiuarv luminous phenomena in clouds without storms,
vide Annuaire for 1838, p. 279.

150 (p. 62.)— Herodotus, iv. 28. The old prejudice (Pliny,
ii. 80), that Egypt never suflTers from earthquakes, is an-
swered by the colossal statue of Memnon. which has been
again restored (Letronne, La Statue vncale de Memnon,
1833) ; but the valley of the Nile does lie without the circle

of concussion of Byzantium, the Archipelago, and Syris
(Ideler ad Aristot. Meteor, p. 684).

151 (p. 62.)— Saint-Martin, in the learned notes to Le-
beau. Hist, du Bas Empire, t. ix. p. 401.

152 (p. 62.)— Humboldt, Asie centrale, t. ii. p. 110—118.
On the difference between concussion of the surface and
the strata lying under it, vide Gay-Lussac, in the Annales
de Chimie et de Physique, t. xxii. p. 429.

153 (p. 62.)— Tutissimum est cum vibrat crispante ledifi-
ciorum crepitu ; et cum intumescit assurgens alternoque
motu residet, innoxium et cum concurrentia teota contrario
ictu arietant ; quoniam alter motus alteri renititur. Un-
dantis inclinatio et fluctus more quaedam volutatio infesta
est, aut cum in unam partem totus se motus impellit (Plin.
ii. 82). ^

l'''4 (p. 62.) — Even in Italy they have begun to acknowledge
the independence of earthquakes of the state of the weather,
i. e. the appearance of the heavens immediately before the
concussion. F. Hoff'inann's numerical results accord in all
respects with the experience of the Abb6 Scina, of Palermo
(Posthum. Works, vol. ii. p. 386- .S95). 1 have myself sev-
eral times observed reddish clouds on the day of shocks,
and shortly before they happened ; on the 4th Nov. 1799,
indeed, I experienced two smart shocks at the moment of a
loud clap of thunder (Relat. Hist. liv. iv. chap. 10). Va-
salli Eandi, of Turin, observed Volia's electrometer much
agitated during the protracted earthquake of Pignerol, April
2 to May 17, 1808 (Journ. de Physique, t. Ixvii. p. 291).
But these signs from clouds, from altered aerial electricity,
and from calms, cannot be regarded as universally signifi-
cant, as necessarily connected with earthquakes. In Quito,
Peru, and Chili, as well as in Canada and Italy, many
earthquakes are observed along with the clearest skies,
with the freshest land and sea-breezes. But if no meteoro-
logical iniJicati(m present itself on the day of the shock, or
shortly before this occurs, it seems impossible to overlook
the influence of particular seasons (the vernal and the au-
tumnal equinoxes), i. e. the commencement of the rainy sea-
son after long drought within the tropics, and the change
of the monsoons according to popular belief, although we
cannot perceive the genetical connection of meteorological
processes with what takes place in the interior of the earth.
Numerical inquiries on the distribution of earthquakes
throughout the course of the year, such as have been insti-
tuted with great industry by Von Hoff", Merian, and Fried.
Hofl^mann, vouch for their frequency at the epochs of the
equinoxes. It is very reniarkal)!e that Pliny designates au
earthquake a subterraneous thunder-storm, not so much by
reason of the rolling noise as because he holds tliat the
elastic concussive forces acting through their tension accu-
mulate in tlie interior of the earth when they are absent in
the atmosphere: Ventos in causa esse non dubium reor.
Neque enim unquam intremiscunt terrae, nisi sopito marl
caeloque adeo tranquillo, ut volatus avium non pendeant,
sul)tracto omni spiritu qui vehit ; nee unquam nisi post
ventos conditos, scilicet in venas et cavernas ejus occulto
afflutu. 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 (Plin.
ii.79; in Seneca, Nat. Quaest. vi. 4 — 31). In these words
we see the germ of all that has since been said soberly, or
dreamed on the causes of earthquakes.

[Mr. Edmonds— Cornwall Journal (?)— has endeavoured
to connect the occurrence of earthquakes with the period
of the moon. He shows that a great number of the most
disastrous have occurred the day after the first quarter.
— Tr.]

iss (p. 62.)— I have given data which show that the hour-
ly variation of the barometer is not affected before or after
earthquakes, in my Relat. Hist. t. i. p. 311 and 513.

156 (p. 62.)— Humboldt, Rel. Hist. t. i. p. 515-517.

157 (p. 63.)— On the Bramidos of Guanaxuato, vide my
Essai polit. sur Iji Nouv. Espagne, t. i. p. 303. The sub-
terraneous noises without any appreciable movement of the
earth in the deep mines or on the surface (6420 feet above
the level of the sea) were not heard in the lofty table-lands
in the neighbourhood, Init only in the hilly parts of the
Sierra, from the Cuesta de los Aguilares, not far from Mar-
sili northward, to Santa Rosa. And the waves of sound did
not reach to particular parts of the Sierra 6 or 7 milea
north-west of Guanaxuato to the other side of Chichitne-
quillo, near the boiling spring of San Jos6 de Comangillas
Very severe measures were taken by the magistracy of th
mountain town, when the alarm at the sounds was at it»
height. " 14th Jan. 1784.— The flight of a family of wealthy
persons shall be punished with a fine of 100 piastres ; that
of poor persons with two months' imprisonment. The mi-
litia are empowered to bring back fugitives." Not the least
remarkable point is the opinion which the gentry (el Ca-
bildo) are to form from their belter knowledge : " The
gentry, in their wisdom (en su Satddura), will know when
there is any danger, and then they may recommend flight ;
for the present, processions are all that are requisite." A
famine was the consequence of the alarm for the truenos ;

NOTES TO PRECEDING SECTION.

123

no one would venture down into the Sierra from the pla-
teaus where corn abounded.

The ancients were also acquainted with noises without
earth(iuakes (Arist. Meteor, ii. ; Plin. ii. 80}. The strange
noise which was heard from March 1822 to September 1B24,
in the Dalmatian island Meleda (4 miles from Ragusa), and
on which Partsch has thrown so much light, was accompa-
nied by shocks from lime to time.

158 (p. 64.) —Drake, Nat. and Stat. View of Cincinnati,
p. 232—238 ; Mitchell, in the Transactions of the Lit. and
Philos. Soc. of New York. toI. i. p. 281—308. In the Pied-
montese county of Pignerol, glasses of water which were
filled to the brim continued for hours in incessant motion.

ii"''-> (p. fi4.)— In Spanish they say: "rocas que hacen pu-
ente." With this phenomenon of non-transmission through
superior strata, is connected the remarkable fact that, in
the beginning of the present century, shocks of an earth-
quake were felt in the deep silver mines of Marienberg, in
the Saxon Erzgebirge, which were not perceived at all on
the surface. The miners rushed up in alarm. Contrari-
wise, the people at work in the mines of Falun and Pers-
berg felt nothing of the smart shocks (Nov. 1823) which
threw all the inhabitants above ground into a state of great
alarm.

160 (p. 64.) — Sir Alex. Burnes, Travels into Bokhara, vol.
1. p. 18 ; and Wathen, Mem. on the Usbek State, Journal
of the Asiatic Soc. of Bengal, vol. iii. p. 337.

161 (p. 64.)— Philos. Transact, vol. xlix. p. 414.

162 {p. 65.) — On the frequency of earthquakes in Cash-
mir, vide Troyer's Uebersetzung des alien Radjatarangini,
Tol. ii. p. 279 ; and the Reise von Carl v. Hiigel, Bd. ii. S. 184.

I6;i (p. 65.) — Strabo, lib. i. p. 100, Casaub. That the
phrase i:r]\oh iianvpov voranov does not mean mud, but
lava, appears plainly from Strabo, lib. vi. p. 412. Vide Wal-
ter iiber Abnahme der vulkanischen Thfttigkeit in histor-
ischen Zeiten, 1844, S. 25.

164 (p. 66). — Bischoff's comprehensive work, WSrmelehre
des inneren Erdkorpers.

165 (p. 66.)— On the Artesian fire-springs (Ho-tsing) in
China, and the ancient use oi portable gas, in bamboo tul)es,
in the city of Khiung-tscheu, vide Klaproth, in my Asie
centrale, t. ii. p. 519—530.

166 (p. 66.) — Boussingault (Annales de Chimie, t. Iii. p.
181) observed no escape of hydrochloric acid in the vol-
canoes of New Granada, whilst Monticelli found this acid
in enormous quantities during the eruption of Vesuvius of
1813.

167 (p. 66.) — Humboldt, Recueil d'Observ. astronomiques,
t. i. p. 311 (Nivellement barom6trique de la Cordill^re des
Andes, No. 206).

163 (p. 66.) — Adolph Brongniart, in the Annales des Sci-
ences natu relies, t. xv. p. 225.

it)9 (p. 66.)— Bischoff. op. cit. 324, Anm. 2.

170 (p. 66.)— Humboldt, Asie centr. t. i. p. 43.

171 (p. 66.)— On the Theory of the Isothermal lines, see
the clever papers of Kupffer in Poggend. Ann. Bd. xv. S.
184, and Bd. xxxii. S. 270 ; in the Voyage dans I'Oural, p.
382—398 ; and in the Edinb. Journ. of Science, new series,
vol. iv. p. 355. See also Kflmtz, Lehrb. der Meteor. Bd.
ii, S. 217 ; and on the ascent of the Chthonisothermal lines
in mountainous countries, Bischofi^, S. 174—198.

172 (p. 66.) — Leop. V, Buch in Poggend, Ann. Bd. iii, S.
405.

173 (p. 66.) — On the temperature of the drops of rain in
Cumana, which falls to 2230 c. (7210 F.) when the tem-
perature of the air shortly before had been 30°— 31^0. (86°
— 87-8° F.). and sinks during the rain to23-40C. (751° F.),
vide my Relat. Hist. t. ii. p. 22. The rain-drops as they
fall change the temperature they had on their production,
which depends on the height of the clouds whence they
come, and the heating of these on their upjier surface by
the sun's rays. After the rain-drops, on their first forma-
tion, by reason of the latent caloric of the vapour becoming
sensible, have acquired a higher temperature than the sur-
rounding medium, they still rise somewhat in temperature,
whilst, as they fall through lower, warmer, and moister
strata of air, vapour continues to be preci pitated upon them,
and they increase in size (Bischoff, Warmelehre, S. 73) ;
but this rise is compensated by evaporation. Cooling of the
air by rain is effected (setting aside what probably belongs
to the electrical processes attending thunder storms) by the
drops, which are themselves of lower temperature, in con-
sequence of the place of their formation, and farther bring
down a portion of the higher colder air ; and then by moist-
ening the ground and giving occasion to evaporation. Such
are the usual relations of the phenomenon. When, in rare
cases, the rain-drops are warmer than the lower strata of
the atmosphere (Humboldt, Relat. Hist. t. iii. p. 513), the
reason may perhaps be sought for in superior warmer cur-
rents, or in a higher temperature acquired by extended and
not very dense clouds exposed to the action of the rays of
the sun. How, for the rest, the phenomena of supplement-
ary rainbows (explained by the interferences of light) are
connected with the size of the falling drops and their in-

crease, and how an optical phenomenon, when rightly ob»
.served, may enlighten us in regard to a meteorological pro-
cess, according to diversity of zone, has been shown with
great acuteness by Arago, in the Annuaire for 1836, p. 300,
174 (p. 66.)— Boussingault's careful experiments satisfy
me that in the tropics the temperature of the ground a very
short way below the surface corresprnids exactly with the
mean temperature of the air. I have pleasure in quoting
the following table :

Oti.-f.>ot on

.Mean temper
afure of

Height Hbove tlie

der tlie

level of the sea,

surface.

the .-lir.

in Parisian feet

Guayaquil . .

260O c.

25 -60 C.

0

Anserma nuevo

23-7

23-8

3231

Zupia . . . ,

21-5

21-5

3770

Popayan . . ,

18-2

18-7

5564

Quito ....

15-5

15-5

8969

The doubt about the temperature of the earth within the
tropics, which 1 have perhaps myself contributed to raise
by my observations in the Cave of Caripe (Cueva del Gua-
charo), are resolved by the consideration that I compared
the presumed mean temperature of the air of the convent
of Caripe (18 5°), not with the temperature of the air of the
cavern (lb-70), liut with the temperature of the subterra-
nean stream (16-80) ; I have, however, said, that it was
very possible that mountain water from a great height
might be mixed with the water of the cavern (Relat, hist,
t. iii. 146-194).

175 (p. 67.) — Boussingault, in Annales de Chimie, t. Iii.
p. 181. The spring of Chaudes Aigues in Auvergne, is only
80O C. It is also to be observed that, whilst the aguas ca-
lientes de las Trincheras burst out from a granite rock,
split into regular blocks, and far from all volcanoes, and
have fully a temperature of 97° C., the whole of the springs
that rise on the Hanks of still active volcanoes, Pasto, Coto-
paxi, and Tunguragua, only show a temperature of from
360 to 540.

176 (p. 67.) — The Cassotis, or spring of St. Nicholas, and
the Castalia, foot of the Phaedriadae (Pausauias, x. 24, 25,
and X. 8, 9) ; the Pirene, Aciocorinth (in Strabo. p. 379) j
the Erasinos-spring, Mount Chaim, South from Argos (in
Herodotus, vii 67, and Pausanias, ii. 24, 7) ; the spring of
Aedepsos, Cubcea, some of which have a temperature of 310,
others one of from 620 to 750 (in Strabo, p. 60 and 447,
Athenseus, ii. 3, 73) ; the hot springs of Thermopylae, fool
of Oeta, 650 (in Pausan. x. 21, 2) ; all from MS. notices by
Professor Curlius. the learned companion of Otfried Miiller,

177 (p. 67.)— Plin, ii. 106: Seneca, Epist. 79, ^ 3, ed.
Ruhkopf. (Beaufort, Survey of the Coast of Karamania,
1820, Art. Yanar, next Deliktasch, the ancient Phaselis, p.
24). See also Ctesias, Fragm. cap. x. p. 250, ed. Bfthr .
Strabo, lib. xiv. p. 665, Casauli.

178 (p. 67.)— Arago, in Annuaire for 1845, p. 234.

179 (p. 67.)— Acta S. Patricii, p. 555, ed. Ruinart, t.ii, p
385, Mazochi. Dureau de la Malle first directed attention
to this remarkable passage, in his Recherches sur la Topo-
graphic de Carthage, 1835, p. 276, (Vide Seneca, Nat.
Quaest. iii. 24.)

ISO (p. 68.)— Humboldt, Rel. hist. t. iii. p. 562—567 ; Asie
centrale, t. i. p. 43, t.ii. p. 505— 515; Vuesdes Cordiileres,
pi. xli. On the Macalubi (the Arabic Makhlub, cast down),
and how the earth ejected liquid earth, vide Solinus, cap.
V. ; idem ager Agrigenlinus eruclat limosas scaturigines,et
ut venae fontium suflficiunt rivis subministrandis, ita in hao
Siciliae parte solo nunquam deficiente, aeterna rejectatione
terram terra evoiriit,

181 (p. 68.)— See the interesting little map of the island
Nisyros, in Rose, Reise auf den griechischen Inseln, Bd. ii,
1843-, S. 69.

182 (p. 68.)— Leopold von Buch, Phys, Beschreibung der
Canarischen Inseln, S. 326 ; and on Erhebungscratere und
Vulcane, in Poggend. Ann. Bd. 37, S. 189, Strabo distin-
guishes very finely between the two modes in which islands
are produced, when he sjieaks of the separation of Sicily
from Calabria. ".Some islands," he says (lib. vi. p. 258, ed.
Casaub.), "are fragments of the continent; others have
arisen from the sea— an event that still happens at the pres-
ent day : for the islands of the great ocean have probably
been lifted from its bosom, those that lie off promontories
have probably been detached from the main land."

183 (p. 68.) — Ocre Fisove (Mons Vesuvius) in the Umbri-
an language, (Lassen. Deutung der Eugubinischen Tafeln,
im Rhein. Museum, 1832, S. 387) ; the word ocre is prob-
ably genuine Umbrian, and means, as Festus informs us.
Mountain. Minn, if kiTvti be, as Voss says, an Hellenic
sound, and be connected with aldiii and aiQivoi, may signify
a burning and shining mountain. But this etymological der-
ivation seems doubtful. The word ^Etna would probably
be found a Sicilian word, had we but any remains of the
Sicilian language. The oldest eruption of Etna spoken of
is that referred to in Pindar and ^schylus under Hiero
(Olymp. 75, 2), But it is probable that Hesiod was aware
of eruptions of the mountain before the settlement of the

134

NOTES TO PRECEDING SECTION.

Greek Colony. The word klrvrj in the text of Hesiod, is
of doubtful origin, as I have shown elsewhere. (Humboldt,
Exameu. crit. de la G6qgr. t. i. p. 168.)

184 (p. 68.)— Seneca, Epist. 79.

185 (p. 68.)— Aelian. Var. hist. viii. 11.

186 (p. 69.)— Petri Bembi Opuscula (Aetna Dialogus),
Basil. 1556, p. 63 ; " Quicquid in Aetnae matris uterocoale-
Bcit, nunquam exit ex cratere superiore, quod vel eo ince-
dere gravis materia non queat, vel, quia inferius alia spira-
tnenta sunt, non fit opus. Despumant flammis urgentibus
ignei rivi pigro fluxa tolas delambentes plagas, et in lapi-
dem indurescunt."

18" (p. 69.)— See my drawing of the volcano of Jorullo,
of its Hornitos and of the uplifted Malpays, in my Vues de
Cordiil^res, PI. xliii. p. 239.

1*^ (p. 69.) — Humboldt, Essai sur la G6ogr. des plantes
et Tableau phys. des Regions 6quinoxiales, 1807, p. J30,
und Essai geogn. sur le gisement des Roches, p. 321. But
that the total absence of streams of lava, along with inces-
sant activity of volcanoes, is not connected solely with the
configuration, position, and absolute height of the mountains,
■we are assured by the phenomenon of the greater number
of the volcanoes of Java. (Vide Leop. von Buch, Descr.
phys. des lies Canaries, p. 419 ; Reinwardt and Hoffmann
m Poggend. Ann. Bd. xii. S. 607.)

I8i) (p. 70.)— See the bases of my measurements compared
with those of Saussure and Lord Minto, in the Abhand-
lungen der Acad6mie der Wiss. zu Berlin kus den J. 1822
and 1823, S. 30.

190 (p. 70.)— Pimelodes Cyclopum s. Humboldt, Recueil
^'Observations de Zoologie et d'Anatomie compar6e, t. i. p.
21-25.

191 (p. 71.) — Leop. von Buch, in Poggend. Ann. Bd. xxxvii.
«. 179.

192 (. 71.) — On the chemical origin of iron glance in vol-
canic masses, vide Mitscherlich in Poggend. Ann. Bd. xv.
S. 630 ; and on the extrication of hydrochloric acid gas,
Gay-Lussac in the Annales de Chimie et de Phys. t. xxii.
p. 423.

193 (p. 71.) — See the beautiful experiments on the refri-
geration of rocky masses in BischoflTs Wavmelehre, S. 384,
443, 500—512.

194 (p. 71.) — Berzelius and Wohler in Poggend. Annalen,
Bd. i. S. 221, and Bd. xi. S. 146 ; Gay-Lussac, in the Annales
de Chimie, t. xxii. p. 422; Bischoff, Reasons against the
Chemical Theory of Volcanoes, in the English edition of his
Wftrmelehre, p. 297—309.

195 (p. 72.) — According to Plato's geognostic notions, as
they are exposed in the Phiedo, Periphlegethon, in respect
of the activity of volcanoes, plays nearly the same part
which we now ascribe to the increased heat of the earth
with the greater depth, and the melted state of the internal
strata of the earth. (Phaedo, ed. Ast. p. 603 and 607, An-
not. p. 808 and 817.) " Within the earth, all around, there
are greater and smaller caverns. There water flows in
abundance ; and also much fire, great fire-streams, and
streams of wet mud (here purer, there more filthy) as in
Sicily the streams of mud that are poured out before and
along with the fire-stream itself: all places arc filled with
these, according as each of the streams takes its several
way. Periphlegethon flows out into an extensive district
burning with fierce fire, where it forms a lake larger than
our sea, boiling with water and mud. From hence it moves
in circles round the earth turbid and muddy." This stream
of melted earth and mud is so much the general cause of
volcanic phenomena, that Plato adds : " Thus is Periphle-
gethon constituted, from which also the fire-streams (o?
^vaKcg) inflate small or detached portions wherever these
are met with on the earth (ottt] tiv rvx^oai tJjs y^/j). Vol-
canic scoriie and lava streams are therefore portions of per-
iphlegethon itself, portions of the subterranean melted and
ever-moving mass. That ol pvaKcg are lava streams, and
not, as Schneider, Passow, and Schleiermacher, will have
it, "fire-vomiting mountains," appears from many passages
that have been already collected by Ukert (Geogr. der
Oriechen und Romer, Th. ii. 1. S. 200) ; ^va}, is the vol-
canic phenomenon seized from its most remarkable point of
view, the lava stream. Whence the expression the ^xuikcs
of JEtna. Aristot. Mirab. Ausc. t. ii. p. 833, (> 38, Bekker ;
Thucyd. iii. 116 ; Theophr. de Lap. 22, p. 427; Schneider,
Diod. v. 6, and xiv. 59, where the remarkable -words : '' many
places near the sea, not far from .^tna, were destroyed,"
vnb Tov kuXovu'evov pvuKog ; Strabo, vi. p. 269, xiii. p, 628,
and of the celebrated glowing mud of the Lelantine plain in
Cubaea (Strabo, i. p. 58, Casamb.) ; lastly Appian. de bello
civili,vi. 114. The blame which Aristotle throws on the
geological fancies of the Phaedo (Meteor, ii. 2, 19) attaches
only to the rivers which flow over the surface of the earth.
The expression, so distinct in reference to the " eruptions
of wet mud in Sicily preceding the gl'>wing (lava) streams"
is very remarkable. Observations on JEtna could not have
led to such language, unless torrents of ashes or pumice
mixed with the melted snow and water of the cone during
ftn eruption, were taken for ejected mud. It seems more

probable that the vypov Trtj^ou iroTaftot of Plato, the " moiflt
mud streams," are an obscure recollection of the mud-vol-
canoes of Agrigentum, which 1 have already referred to
(Note 89), which eject mud with loud noises. The loss of
one among the many lost writings of Theophrastus : nco}
pvaKOs rov iv "ZiKiyt'cf, of which Diogenes Laertius (v. 39)
makes mention, is much to be regretted in connection with
this subject.

19*5 (p. 72.)— Leopold von Buch, Physical. Beschreib. der
Canarischen Inseln, S. 326 — 407. I doubt whether we can,
with the able Darwin (Geological Observations on the Vol-
canic Islands, 1844, p. 127), regard Central volcanoes in
general as Rank volcanoes of small compass developed ou
pjirallel fissures. Fried. Hoff^mann believed that he per-
ceived in the group of the Lipari islands, which he has so
well described, and in which two eruption-fissures cross
each other near Panaria, an intermediate member between
the two principal modes in which volcanoes appear, the
central, and the rank or row-volcanoes of Leopold von Buch
(vide Poggend. Annal. 26, p. 81).

197 (p. 72.) — Humboldt, Geognost. Beob. iiber die Vulkane
des Ilochlandes von Quito, in Poggend. Annalen, Bd. xliv.
S. 194.

198 (p. 72.)— Seneca, whilst he speaks very pointedly on
the problematical lowering of ^Etna, says, in his 79th let-
ter: ''Potest hoc accidere, mm quia montis altitudodesedit,
sed quia ignis evanuit et minus vehemensaclarguseffertur;
ob eandem causam, fumo quoque per diem segniore. Neu-
trum autem incredibile est, nee montem qui devoretur quo-
tidie minui, nee ignem non manere eundem ; quia non ipse
ex se est, sed in aliqua inferna valle conceptus exaestuat et
alibi pascitur : in ipso monte non alimentum habet sed
viam." (Ed. Ruhkopfiana, t. iii. p. 32.) The subterrane-
ous communications, " by means of galleries," between the
volcanoes of Sicily, Lipari, Pithecuse (Ischia), and Vesu-
vius, which may be conjectured to have been formerly on
fire, are fully recognized by Strabo, who calls the whole
country "subigneous." (Lib. i. p. 247, 248.)

199 (p. 72.) — Humboldt, Essai polit. sur la Nouv. Espagne,
t. ii. p. 173—175.

'JOO (p. 73.)— On the Eruption of Methone, vide Ovid.
Metamorphos. xv. 296—306) :

" Est prope Pittheam tumulus Troezena sine ullis
Arduus arboribus, quondam planiss)ma campi
Area, nunc tumulus ; nam — res horrenda relatu —
Vis fera ventorum, caecis inclusa cavernis,
Exspirare aliqua cupiens, lucta*aque frustra
Liberiore frui coelo, cum carcere rima
Nulla foret toto nee pervia flatibus esset,
Extentam tumefecit humum ; ceu spiritus oris
Tendere vesicam solet, aut direpta bicorni
Terga capro. Tumor ille loci p«rmansit, et alti
Collis habet speciem, longoque induruit aevo."

This description of a dome-shaped elevation of the land, so
important in a geological point of view, accords remarkably
with what Aristotle says, (Meteor, ii. 8, 17—19) on the up-
liftment of an Erupticm island. " The quaking of the earth
does not cease until the wind (avcfioi) which occasions the
shocks has made its escape into the crust of the earth. So
did it happen lately at Heraclea in Pontus, and formerly
too in Hiera, one of the jEolian islands. In this a portion
of the earth swelled up and rose into the shape of a hill
with loud noises, until the powerful lifting breath (irvEi'tJia)
found a vent, and threw out sparks and ashes, which cov-
ered the neighbouring town of the Liperians, and even ex-
tended to several towns of Italy." In this description, the
vesicular-like distension of the crust of the earth (a state in
which many trachytic mountains have remained) is very
well distinguished from the erupti<m itself. Strabo (lib. i,
p. 59, ed. Cas.) likewise describes the phenomenon of Me-
thone : " Near the town in the Hermionian bay, a flaming
eruption took place ; a fiery mountaiti was thrown up, sev-
en (?) stadia high, inaccessible during the day from heat
and sulphureous odours, but sweet-smelling (?) in the night,
and so not that the sea i)oiled five stadia off, and was turbid
full twenty stadia out, and was also filled full of detached
masses of rock." On the present niineralogical constitution
of the peninsula of Methone, vide Fiedler, Reise durch
Griechenland, Th. i. S. 257—263.

201 (p. 73.) — Leop. von Buch, Physik. Beschr. der Canar.
Inseln, S. 356 — 358, particular'y the French translation of
this excellent work, p. 402 ; also in Poggendorff's Annalen,
Bd. xxxvii. S. 183. A submarine island was again in the
most recent times formed in the crater of Santorin. In
1810 this island was still 15 fathoms under the surface of
the sea; but in 1830 (mly 3 or 4 fathoms. It rises steeply
like a great cone from the bottom of the sea ; and the per-
sistence of the sul)marine activity is proclaimed by the ad-
mixture of sulphuric acid vapours with the sea-water, so
that ships which are coppered, lying at anchor in the bay
t)f Neo-Kammeiii,as well as at Wnmiolimni near Methana,
have their bottoms cleansed and made bright without fur-
ther trouble. (Vide Virlet in Bulletin de la Society g6olo-

NOTES TO PRECEDING SECTION.

125

triqiie (le Franre, t. iii. p. 109, and Fiedler, Reise durch
Gnecheiihmd. Th. ii. S. 469 and 5S4.)

^^ (p. 73.) — Appearances of new islands near San Mi-
guel, one of the Azores: 11th June, 1638, 31st December,
1719, ISihJune, 1811.

-03 (p. 73.)— Prevost. in Bulletin de la Soci6t^ j?6olog-ique,
t. ii. p. 34 ; Friedrich Hoffmann, liinterlassene Werke, Bd.
ii. S. 451—456.

204 (p. 73.)_«< Accedunt ricini et perpetui Aetnae mentis
ignes et insuiarum Aeolidum, veluti ipsis undis alatur irt-
cendium ; neque enim aliter durare tot seculis tantus ignis
potuisset, nisi humoris nutrimentis aleretur." (Justin,
Hist. Philipp. iT. i.) The volcanic theory with which the
physical description of Sicily here begins is extremely in-
tricate. Deep-lying beds of sulphur and rosin, an extreme-
ly thin crust, full of cavities and readily divided ; violent mo-
tion of the waves of the sea, which, as they strike togeth-
er, draw down air (the wind) for the maintenance of the
fire : such are the elements of the theory of Trogus. As he
presents himself as a physiognomist in Pliny (xi. 52), we
may presume that he did not limit himself to history alone ;
but many of his works are lost to us. The view according
to which air was forced into the interior of the earth, there
to influence the volcanic force, is moreover connected with
the notions of the ancients on the inflience exerted by the
direction of the wind upon the intensity of the fire which
burns in ^tna, in Hiera and Stromboli (see the remarkable
passage in Strabo, lib. vi. p. 275 and 276). The mountain-
ous island of Stromboli (Strongyle) was therefore regarded
as the seat of ^olus, " the controller of the winds," as the
sailors foretold the weather from the violence of the vol-
canic eruptions of Stromboli. Such a connection between
the eruptions of a small volcano and the state of the barome-
ter and the quarter of the wind is still recognised {vide Leop.
von Buch, Descr. phys. des lies Canaries, p. 334 ; Hoffmann
in Poggend. Ann. Bd. xxvi. S. 8) ; although it must be allow-
ed that all our present knowledge of volcanic phenomena, and
the slight alterations in the pressure of the air that accom-
pany our winds, do not enable us to offer any satisfactory
explanation of the fact. Bembo, brought up as a youth by
Greek exiles in Sicily, gives a pleasant narrative of his
wanderings, and in his " ^tna Dialogns" (middle of the
I6th century) advances the theory of the penetration of sea
water to the focus of the volcano, and of the necessity of
the neighbourhood of the sea. On ascending -(Etna the
following question is thrown out: " Explana potius nobis
quae petimus, ea incendia unde oriantur et orta quomodo
perdurent? In omni tellure nuspiam majores fistulae aut
meatus arapliores sunt quam in locis, quae vel mari vicina
sunt, vel a mari protinus alluuntur : mare erodit ilia facil-
lime pergitque in viscera terrae. Itaque cum in aliena
regna sibi viam facial, ventis etiam facit ; ex quo fit, ut
loca quaeque maritima maxime terraemotibus subjecta sint,
parum mediterranea. Habes quum in sulfuris venas venti
fureules inciderint, unde incendia oriantur Aetnae tuae.
Vides, quae mare in radicibus habeat, quae sulfurea sit,
quae cavernosa, quae a mari aliquando perforata ventos
admiserit aestuantes, per quos idouea flammae materies in-
cenderetur.

205 (p. 73.)— See Gay-Lussac, sur les Volcans, in den
Annales de Chimie, t. xxii. p. 427; and Bischoff, Warme-
lehre, S. 372. Reactions of the volcanic hearth through
tensive columns of water, viz., when the expansive force of
the vapour surpasses the hydrostatic pressure, are proclaim-
ed by the erupticms of smoke and aqueous vapour, which
are observed at different times in Lancerote, Iceland, and
the Kurile islands during eruptions of the neighbouring
volcanoes.

2oe (p. 73.)— Abel-Remusat, Lettre a Mr. Cordier, in the
Annales des Mines, t. v. p. 137.

207 (p. 73.)— Humboldt, Asie centrale, t. ii. p. 30—33,
38-52. 70—80, and 426-428. The existence of active vol-
canoes in Cordofan, 135 miles from the Red Sea, has lately
been denied by Riippell (Reise in Nubien, 1829).

208 (p. 74.)— Dufrenoy et Elie de Beaumont, Explication
de la Carte g6ologique de la France, t. i. p. 89.

•209 (p. 74.)— Sophocl. Philoctet. v. 971 and 972. On the
conjectural epoch of the extinction of the Lemnian fire in
the time of Alexander, vide Buttmann in Museum der Al-
terthumswissenschaft, Bd. i. 1807, S. 295 ; Dureau de la
Malle in Malte-Brun, Annales des Voyages, t. ix. 1809, p.
5 ; Ukert in Bertuch, Geogr. Ephemeriden, Bd. xxxix. 1812J
S. 361 ; Rhode, Res Lemnicae, 1829, p. 8, and Walter Uber
Abnahme der vulkan. Thatigkeit in historischen Zeiten,
1844, S. 24. The hydrographical conception of Lemnos by
Choiseul makes it extremely probable that the extinct found-
ations of Moschylos, together with the island Chryse, Phil-
octetes' desolate abode (Otfried Miiller, Minyer, S. 300)
have been long swallowed up by the sea. Reefs and shoals
to the North-east of Lemnos still show the spot where the
iEgaan Sea possessed an active volcano like Jctna, Vesuvi-
us, Stromboli, and that of the Lipari isles.

210 (p. 74.) — Vide Reinwardt and Hoffmann in Poggen-
dorff's Aunalen, Bd. xii. S. 607 ; Leop. von Buch, Descr.

des lies Canaries, p. 424,426. The argillaceous irind erup-
tions of Carguairazo, when tae volcano crumbled together
in 1698, the Lodazales of Igualata, and the Moya of Pelileo,
are volcanic appearances of the same Jiature in the high-
lands of Quito.

211 (p. 74.)— In a profile of the environs of Tezcnco, To-
toniico, and Moran, (Atlas g6ographique et Physique, PL
vii.) which I originally (1803) designed for a Pasigrafia
geognostica destinada al uso de los Jovenes del Colegio de
Mineria de Mexico, but which was never published, I en-
titled (1832) the Plutonic and volcanic eruptive rocks endo'
genous, (that which is engendered in the interior,) the sedi-
mentary and floEtz rocks exogenous (externally engender-
ed). Pasigraphically the former were indicated by an arrow
directed upwards, f , the latter by an arrow directed down-
wards, I , signs which had certain pictorial advantages, and
permitted the nature of the rock to be shown without having
recourse to those very unpicturesque and arbitrarily-shaped
cones which are generally seen in such profile drawings.
The titles endogenous and exogenous were borrowed from
Decandolle, who uses the former in connection with raono-
cotyledonous, the latter with dicotyledonous plants. Bat
Mohl's more careful vegetable anatomy has shown, that in
the strict sense of the words the growth of monocotyledo-
nous vegetables does not proceed from within, nor that of
decotyledonous plants /row without. ( Vide Link, Elementa
philosophiae botanicae, t. i. 1837, p. 287 ; Endlicher und
linger, Grundziige der Botanik, 1843, S. 89 ; and Jussieu,
Trait6 de Botanique, t. i. p. 85.) What I call endogenous,
Lyell, in his Principles of Geology, 1833, vol. iii. p. 374,
characterises by the expression " netherformed" or " hy-
pogene rocks."

212 (p. 74.) — Vide Leop. von Buch iiber Dolomit als
Gebirgsart, 1823, S. 36 ; and farther, Ueber den Grad
der Fliissigkeit, welchen man plutonisohen Felsarten bei
ihrem Heraustreten zuschreiben soil, wie iiber Entstehung
des Gneuss aus Schiefern durch Einwirkung des Granits
und der mit seiner Erhebung verbundeneu Stoffe, as well
as in the Abhandl. der Akad. der Wissench. zu Berlin aus
dem Jahre 1842, S. 58 und 63, and in the Jahrb. fur wis-
senschaftliche Kritik, 1840, S. 195.

213 (p. 75.)— Darwin, Volcanic Islands, 1844, p. 49 and
154.

214 (p. 75.) — Moreau de Jonnes, Hist. phys. des Antilles,
t. i. p. 136, 138, and 543 ; Humboldt, Relation historique,
t. iii. p. 367.

215 (p. 75.)— At Teguiza j Leop. von Buch, Canarische
Inselna, S. 301.

216 (p. 75.)— Vide above, p. 4.

217 (p. 75.)— Bernhard Cotta, Geognosie, 1839, S. 273.

218 (p. 75.) — Leop. von Buch iiber Granit und Gneuss in
den Abhandl. der Berl. Akad. aus dem J. 1842, S. 60.

219 (p. 75.) — In the granite of the Kolivan Lake, which
rises like walls, and is divided into parallel narrow ledges,
felspar and albite predominate, titanitic crystals are rare.
Humboldt, Asie centrale, t. i. p. 295 ; Gustav Rose, Reise
nach dem Ural, Bd. i. S. 524.

220 (p. 75.)— Humboldt, Relation historique, t. ii. p. 99.

221 (p, 75.) — See the drawing of Biri-tau, which I took
from the south, with Kirghish tents pitched, in Rose, Reise,
Bd. i. S. 584. On granite balls scaling off concentrically,
vide Humboldt, Rel. hist. t. ii. p. 597 ; and Essai g6ogn
sur le Gisement des Roches, p. 78.

223 (p. 75.)— Humboldt, Asie centrale, t. i. p. 299—311,
and the drawings in Rose's Reise, Bd. i. S. 611, in which
the curves of the granitic layers pointed out by Leop. von
Buch as characteristic, are repeated.

223 (p. 75.)— This remarkable stratification was first de-
scribed by Weiss, in Karsten's Archiv fiir Bergbau und
Hiittenwesen, Bd. xvi. 1827, S. 5.

224 (p. 76.) — Dufrenoy et Elie de Beaumont, G6ologie da
la France, t. i. p. 130.

223 (p. 76.)— An important part is played by these sub-
stratified diorites near Steben, in the Nailaer Mountain dis-
trict, a country where I was engaged in mining work in the
last century, and with which some of the happiest associa-
tions of my youth are connected. Vide Friedr. Hoffmann
in Poggendorff's Annalen, Bd. xvi. S. 558.

226 (p. 76.)— In the southern and Baschkir-Ural ; vide
Rose, Reise, Bd. ii. S. 171.

227 (p. 76.)— G. Rose, Reise nach dem Ural, Bd. ii. S.
47 — 52. On the identity of Elaeolite and Nepheline (in the
latter the quantity of lime is somewhat larger), vide Schee-
rer, in Poggend. Annalen, Bd. xlix. S. 359-381.

228 (p. 77.) — See the admirable papers of Mitscherlich, in
the Abhandlungen der Berl. Akad. for the years 1822 and
1823, S. 25—41 ; in Poggendorff's Annalen, Bd. i. S. 137—
152, Bd. xi. S. 323—332, Bd. xli. S. 213—216 (Gustav Rose
iiber Bildung des Kalkspaths und Aragonits in Poggend,
Ann. Bd. xlii. S. 353—366 ; Haidinger, in the Transactions
of the Royal Society of Edinbu^rgh, 1827, p. 148).

239 (p. 77.)— Lyell, Principles of Geology, vol. iii. p. 353
and 359.
330 (p. 78.)— The statements here made of the reJationt

126

NOTES TO PRECEDING SECTION.

of granife in reference to stratification, express the general
or principal cliaracter of the whole formation. In some
places (vide p. 75, and the description of the Narym chain,
hear the boundary of China, Rose's Reise, Bd. 1. S. 599)
granite indeed shows confijjuralions which lead us to con-
jecture that at the period of its eruption it was not always
without fluidity, just as happens in the case of Trachyte
(Dufrenoy et Elie de Beaumont, Description g6ologique de
la France t. i. p. 70). As we have in the text mentioned
Ihe narrow fissures through which basalt has generally flow-
ed, I take the opportunity in this place of referring to the
wide chasms which have served the melaphyrcs (which
must not be confounded with the -basalts) as channels of ef-
flux. See the interesting account by Murchison, in his Si-
lurian System, p. 126, of a chasm 450 feet wide, in the coal-
pit at Cornbrook, Hoar-Edge, through which the melaphyre
has made its way.

231 (p. 78.)— Sir James Hall, in the Edinb. Transact, vol.
V. p. 43, vol. vi. p. 71 ; Gregory Watt, in the Philos. Trans-
actions of the Royal Society of London, for 1804, pt. ii. p.
279 ; Dartigues and Fleuriau de Bellevue, in the Journ. de
Phys t. Ix.'p. 456 ; Bischoff, Warmelehre, S. 313 and 443.

232 (p. 78.) — Gustav Rose, in PoggeudorfTs Annalen der
Physik, Bd. xlii. S. 364.

233 (p. 78.) — On the dimorphism of sulphur, vide Mitscher-
lich, Lehrbuch der Chimie, ^ 55 — 63.

234 (p. 78.)— On gypsum as monuaxal crystal, sulphate of
magnesia, oxides of zinc and nickel, vide Mitscherlich, in
Poggend. Ann. Bd. xi. S. 328.

235 (p. 78.)— Coste, Versuche, in Creusot iiber das briichig
werden des Stabeisens, in Elie de Beaumont, M6m. geol. t.
ii. p. 411.

236 (p. 78.) — Mitscherlich iiber die Ausdehnungder krys-
tallisirten Korper durch die Warme. in Poggend. Ann. Bd.
3t. S. 151.

237 (p. 78.)— On double stratification cleavage, vide Elie
de Beaumont, Geologic de la France, p. 41 ; Credner, Ge-
ognosie Thuringens und des Harzes, S. 40 ; Riimer, das
Rheinische Uebergangsgebirge, 1844, S. 5 und 9.

238 (p. 78.)— With addition of clay, lime, and potash, not
silicic acid si mplv coloured with oxide of iron ; Rose, Reise,
Bd. li. S. 16», 187, and 192: vidt also Bd. i. S. 427, whfere
the porphyry balls are represented between which the jas-
per occurs in the calcareous gray wacke mountains of Bo-
goslowsk, also as a consequence of the Plutonic effects of
Augitic rock : Rose, Bd. ii. S. 545 ; also Humboldt, Asie
centrale, t. i. p. 486.

2:J9 (p. 78.)— Rose, Reise, nach dem Ural, Bd. i. S. 586—
688.

210 (p. 78.)— For the volcanic origin of mica, it is impor-
tant to remember that crystals of mica occur in the basalt
of the Bohemian Middle Mountains ; in the lava of Vesuvius
of 1822 (Monticelli, Sioria del Vesuvio negli anni 1821 e
1S22, t) 99) ; in clay-slate fragments of Hohenfels, not far
from Gerolstein in the Eifel, enveloped in scoriaceous ba-
salt, vide Mitscherlich, in Leonhard, Basalt-Gebilde, S. 244.
On the pri^duction of felspar in clay slate, through the con-
tact of porphyry between Urval and Poiet (Forez), vide Du-
frenoy, in G6ol. de la France, t. i. p. 137. A similar con-
tact gives the slate at Paiiiipol, in Brittany, an amygdaloidal
and cellular character, an api)earance which amazed- me
very much on a geological journey which I made on foot, in
company with Prof. Kunth, through that interesting countiy.

2-41 (p. 78.)— Leopold von Buch in the Abhandlungen der
Akad. der Wissensch. zu Berlin aus dem J. 1842, S. 63;
and in the Jahrbiicher fiir wisseiischaftliche Kritik, Jahrg.
1840, S. 196.

242 (p. 78.) — Elie de Beaumont, in the Annales des Sci-
ences naturelles, t. xv. p. 362 — 372 : *' En se rapprochant
des masses primitives du Mont Rose etdes niontagncs siiu-
fees A I'ouest de Coni, on volt les couches secondairesperdre
de plus les caract^res inh6ients dleur mode de dep6t. Sou-
vent alors elles en prennent qui semblent provenir d'une
toute autre cause, sans perdre pour cela leur stratification,
rappelant par cette disposition la structure physique d'un
tison i moiti6 charbcmn^ dans lequel on peut suivre les tra-
ces des fibres ligneuses, bien au-dela des points qui present-
ent encore les caracte res mutuels du bois." Ft<ie also An-
uales des Sciences naturelles. t. xiv. p. 118- 122; and II.
von Dechen, Geognosie, S. 553. Among the most remark-
able evidences of the transformation of rocks under the in-
fluence of Plutonic agency, are the belemnitcs in the schists
of Nuffenen (Alpine valley of Egine and the Gries-glacier),
as well as the belemnites in the so-called primitive limestone,
which M. de Charpentier discovered on the western flank
of the Col de Seigne, between Enclove de Monjovet and the
Alpine-hut de la Lanchette (Ann. de Chimie, t. xxiii. p.
262), and which he showed me in Bex, in the autumn of
1822.

243 (p. 78.)— Hoffmann, in Poggend. Annalen, Bd. xvi. S.
552. " Strata of the transition clay slate of the Fichtelge-
birge, which can be followed for four miles, and only at ei-
ther extremity, where they come into contact with the gran-
ate converted into gneiss. There we can trace the gradual

formation of gneiss, and the internal development o' mics
and of felspar amygaloids in clay slate, which indeed con-
tains almost all the elements of those substances."

244 (p. 78.)— In the works of the ancient Greeks and Ro-
mans that have come down to us we observe the want of
jasper columns and large vessels of jasper, a substance which
the Ural mountains almost exclusively yield in masses of
any magnitude. The stone that is worked as jasper in the
Altai (Ravennaja Sopka, the Rhubarb mountains) is a mag-
nificent striped porphyry. Theophrastus and Pliny reckon
jasper among the number of non-irai}sparent gems ; and the
latter thinks it incumbent on him to mention a piece of the
mineral eleven inches long which he had seen : " Magnitu-
dinem jaspidis undecim unciarum vidimus, formalainque
inde effigiem Neronis thoracatam." The st(me which The-
ophrastus calls smaragd or emerald, and from which the
great obelisks were hewn, he regards as an unripe iasper.

245 (p. 78.)— Iluinholdt, Lettre a M. Brochant de Villiers,
in the Annales de Chimie et de Physique, t. xxiii. p. 261 ;
Leop. von Buch, Geogn. Briefe iiber das siidliche Tyrol, S.
101. 105, and 273.

246 (p. 79 )— On the transformation of compact into gran-
ular limestone through contact with granite in the Pyrenees
(Montague de Rancie), vide Dufr6noy, in the M^moires g6-
ologiques, t. ii. p. 440; and in the Montagues de I'Oisans,
vide Elie de Beaumont, Mem. geol. t. ii. p. 379— 415 ; by
Dioritic and Pyrorexic Porjjhyries (Ophite ; Elie de Beau-
mont, G6ol. de la France, t. i. p. 72), between Toulouse and
St. Sebastian, vide Dufr6noy, in M6m. g^ol. t. ii. p. 130;
through Syenite, in the island of Elba, in which petrefac-
tions still continue visible in the limesKme, in spite of the
changes it has suffered, M. von Dechen, Geognobie, S. 573.
In the metamorphosis of chalk, through contact with basalt,
the dislocation of the minute particles through the produc-
tion of crystals and the granulation is the more remarkable,
since we have been made aware, by Ehrenberg's discover-
ies, of the fact, that these chalk particles previously consist-
ed of articulated rings (vide Poggendorff's Annal. Bd. xxxix.
S. 105 ; and on the rings of Aragonite precipitated from a
state of solution, Gustav Rose, ib. Bd. xlii. S. 354).

247 (p. 79 ) — Beds of granular limestone in granite at
Port d'Or and Mont de Labourd, vide Charpentier, Consti-
tution giologique des Pyrenees, p. 144, 146.

248 (p. 79.) — Leop. vcm Buch, Descr. des Canaries, p.
394 ; Fielder. Reise durch das Ktinigreich Griechenlind,
Th. ii. S. 181, 190, and 516.

249 (p. 79.)— I have already referred to the remarkable
passage in Origen's Philosophumena, cap. 14 (Opera ed.
Delarue, t. i. p. 893). From the whole context it is not very
unlikely that Xenophanes meant " an impression of laurel,"
(rvtroT] 6d(pvy]i,) not an " impression of a fish," (tvi:ov acpvrjs).
Delarue blames Gronovius unfairly, who made the correc-
tion that " turned the laurel into an anchovy." The petri-
fied fish is a far more likely object than the natural image
of Silenus, which the quarry-men insisted they had dug
out of the marble quarries of Paros (the mountain Mar-
pessos, Servius ad Virgil, ^u. vi. 471), Plin. xxxvi. 5.

250 (p. 79.)_On the geological relations of the town of
Carrara Luna, Selene civitas, vide Strabo, lib. v. p. 222;
Savi, Osservazioni sui terreni jmtichi Toscani, in the Nuovo
Giornale de' Lettcrati di Pisa, No. 63; and Hoffmann, in
Karsten's Archiv fiir Mineralogic, Bd. vi. S. 258-263, as
also his Geogn. Reise durch Itaiien, S. 244—265.

251 (p. 79.)— According to the view of an excellent and
experienced observer, Karl von Leonhard ; see his Jahrbuch
fiir Mineralogie, 1834, S. 329, and Bernhard Cotta, Geog-
nosie, S. 310.

252 (p. 79.)— Leop. von Buch, Geognostische Briefe an
Alex, von Humboldt, 1824, S. 36 and 82 ; also in the Annales
de Chimie, t. xxiii. p. 276, and the Abhandl. der Berliner
Akad. aus den J. 1822 und 1823, S. 83—136 ; H. von Dechen,
Geognosie, S. 574 — 576.

253 (p. 79.)— Hoflfmann, Geogn. Reise bearbeitet von H.
von Dechen, S. 113-119, 380—386; Poggend. Ann. der
Physik, Bd. x.xvi. S. 41.

254 (p. 80.) — Dufr6noy, inM6moircs g6ologiqnes, t.ii. p
145 and 179.

255 (p. 80.) — Humboldt, Essai g6ogn. sur le Gisement de»
Roches, p. 93 ; Asie centrale, t. iii. p. 532.

256 (p. 80.) — Elie de Beaumont, in Annales des Sciences
naturelles, t. xv. p. 362 ; Murchison, Silurian System, p. 266.

257 (p. 80.)— Rose, Reise nach dem Ural, Bd. i. S. 364 and
367.

258 (p. 80.)— Leop. von Buch, Briefe, S. 109—129. Vide
also Elie de Beaumont on the Contact of Granite with Ju-
rastrata, in Mem. g6ol. t. ii. p. 408.

259 (p. 80.)— Hoffmann, Reise, S. 30 and 37.

260 (p. 80.)— On the chemical process in the formation of
iron glance, vtrfe Gay-Lussac in Annales de Chimie, t. xxii.
p. 415 ; and Mitscherlich in Poggend. Ann. Bd. xv. S. 630.
In the cavities of the Obsidian of the Cerro del Jacal, which
I brought with me from Mexico, crystals of olivine have
also been formed (apparently deposited from vapour, vide
Gustav Rose, in Poggend. Ann. Bd. x. S. 323). Olivine

NOTES TO PRECEDING SECTION.

127

therefore occurs : in basalt, in lava, in obsidian, in artificial
Bcoriae, in meteoric stones, in the syenite of Elfdale, and (as
hyalosidcrite) in the Wacke of Kaiserstuhle.

2fii (p. 60.)— Constantin von Beust liber die Porphyrge-
bilde, 1635, S. 89—96 ; his Beleuchtung der Werner'achen
Gangtheorie, 1840, S. 6 ; C, von Weissenbach, Abbildungen
merkwurdigrer Gangverhftltnisse, 1836, fig. 12. The band-
like structure of the veins is however as little general, as is
the sequence in respect of age of the several members of
these masses. Vide Frieslebeu iiber die sflchsischen Erz-
gttnge, 1843, S. 10—12.

2W (p. 80.)— Mitscherlich Ober die kiinstlicheDarstellung
der Mineralicn, in the Abhandlungen der Akademie der
Wiss. zu Berlin aus den Jahren 1822 und 1823, S. 25—4!.

*o (p. 80.)— In scoriie: crystals of felspar discovered by
Heine, after the extinction of a roasting copper ore furnace,
not far from Sangerhausen, analysed by Kersten (Poggend.
Annalcn, Bd. xxxiii. S. 337); of augite in the scoriie of
Sable (Mitscherlich in den Abhandl. der Akad. zu Ber-
lin, 1822 and 1823, S. 40) ; of Olivine (SefstrSm in Leon-
hard, Basalt-Gebilde, Bd. ii. S. 495) ; of Mica in old scoria;
of Schloss Garpenberg (Mitscherlich in Leonhard, loc. cit.
S. 506) ; of magnetic iron in scoriie of Chatillon sur Seine
(Leonhard, S. 441) ; of iron-glance arising in potter's clay
(Mitscherlich in Leonhard, S. 234).

stj* (p. 80.) — Produced on purpose : Idokras and garnet
(Mitscherlich in Poggendorff's Annalen der Physik, Bd.
xxxiii. S..340) ; ruby (Gaudin in Comptes rendus de I'Acad-
6mie des Sciences, t. iv. pt. iv. p. 999) ; olivine and augite
(Mitscherlich and Berthier, in Annales de Chiniie et de
Physique, t. 24, p. 376). Although, according to Gust.
Rose, augite and hornblende show the greatest similarity
in the form of their crystals, and their chemical composition
is almost identical, still hornblende has never been found
by the side of augite in scoriae : even as little have chemists
succeeded in their attempts at producing hornblende or fel-
spar (Mitscherlich in Poggend. Annalen, Bd. xxxiii. S. 340,
and Rose, Reise nach dem Ural, Bd. ii. S. 358 and 363).
See also Beudant, in Mem. de I'Acad. des Sciences, t. viii.
p. 221, and Becquerel's able inquiries, in his Trait6 ed
l'Electricit6, t. i. p. 334 ; t. iii.p. 218; t. v. l,p. 148 and 185.

2t)5 (p. 80.)— D'Aubuisson, in Journal de Physique, t.
kviii. p. 128.

266 (p. 81.)— Leop. von Buch, Geognost. Briefe, S. 75—
82 ; where it is at the same time shown, that the red sand-
stone (the dead layer of the Thuringian floetz formations)
and the coal formation must be viewed as products of erup-
tive porphyritic rocks.

267 (p. 81.) — On Hooke's "hope to raise a chronology"
out of the study of fossil shells, and Ui state the intervals of
the time wherein such or such catastrophes or mutations
have happened, vide Posth. Works, Lecture, Feb. 29, 1688.

267* (p. 81.)— A discovery of Miss Mary Anuing, who also
first discovered the coprolites of fishes. These, and the ex-
crements of the Ichthyosaurus, have been found in such
quantities at Lyme Regis, that they seem to lie, according
to Buckland's expression, " heaped like potatoes upon the
ground." Vide his Geology with reference to Natural The-
olo?y, vol. i. p. 188-202, and 305.

2C>J (p. 81.) — Leop. von Buch, in Abhandlungen der Akad.
der Wiss. zu Berlin aus dem J. 1837, S. 64.

269 (p. 82.) — The same, Gebirgsformationen von Russland,
1840, S. 24-40.

2"0 (p. 82.) — Agassiz, Monographic des Poissons fossiles
du Vieux Gres Rouge, p. vi. and 4.

271 (p. 82.)— Leop. von Buch in Abhandl. der Berl. Akad.
1838, S. 149—168 ; Beyrich, Beitr. zur Kenntniss des Rhein-
ischen Uebergangsgebirges, 1837, S. 45.

2*2 (p. 82.) — Agassiz, Recherches sur les Poissons fos-
siles, t. i. Introd. p. xviii. (Davy, Consolations in Travel,
Dial, iii.)

273 (p. 82.) — According to Hermann von Meyer, a pro-
tosaurus (Paljpologica, S. 229). The rib of a saurian, said
to be from the mountain limestone of Northumberland, is,
according to Lyell, extremely doubtful (Geology, vol. i. p.
148). The discoverer himself asoribes it to alluvial strata
which cover the limestone.

274 (p. 82.)— F. von Alberti. Monographie des Bunten
Sandsteins, Muschelkalks und Keupers, 1834,8. 119 und 314.

27.5 (p. 82.) — See the acute considerations of H. von Meyer
(Palrcologica, S. 228—252) on the organization of the flying
reptiles. In the petrified specimen of Pterodactylus cras-
sirostris, which, as well as the longer known Pterod. lon-
girostris, was found in the lithographic limestone of Solen-
hofen. Professor Goldfuss has found *' traces of the mem-
brane which served for flight," as well as " impressions of
the curled, flocky, in some places inch-long hair, which cov-
ered the skin."

276 (p. 82.)— Cuvier, Recherches sur les Ossemens fos-
siles, t. i. p. Iii. — Ivii. See also the geological scale of
epochs in Phillips's Geology, 1837, p. 166-185.

277 (p. 82.)— Agassiz, Poissons fossiles, torn. i. pt. xxx.
and torn. iii. p. 1—52; Buckland, Geology, vol, i. p. 273
—277.

278 (p, 83.)— Ehrcnberg, iiber noch jetzt khendc Thier-
arten der Krpidei)ildung in den Abhandl. der Berliner Akad.
aus dom J. 1639, S. 164.

279 (p. 63.) — Valenciennes, in Comptes rendus de I'Acad.
des Sciences, torn. vii. 18.38, j)t. ii. p. 580.

^280 (p. 83.)— The Weald-Clay ; Beudant, G^ologie, p.
173. The ornitholites increase in number in the gypsum of
the tertiary formation {Cuvier, Ossemens fossiles, u>iu. iii.
p. 302—328).

281 (p. 83.)— Leop. von Buch, iu Abhandl. der Berl. Akad.
aus dem J. 1830, S. 135-167.

282 (p. 83.)— Quenstedt, Flozgebirge Wurtemberga, 1843,

283 (p. 83.)— Ibid. S, 13.

284 (p. 83.)— Murchison divides the variegated sandstone
into two divisions, the upper of which remains the Trias of
Alberti, whilst out of the lower, to which the Voges-sand-
stone of Elie de Beaumont belongs, the Zechsteiii and the
Todtliegendes, he forms his Permian System. With the
upper trias, i. e., with the upper division of our variegated
sandstone, he begins the secondary formations ; the Per-
mian system, the mountain or carboniferous limestone, the
Devonian and Silurian strata, are with him paleozoic for-
mations. According to these views, chalk and jura are
called the upper, keuper, muschelkalk, and variegated sand-
stone, the inferior secondary formations ; the Permian sys-
tem and the carboniferous lime are entitled the upper, the
devonian and silurian strata together the inferior palseozoic
formations. The basis of this general classification is de-
veloped in the great work in which the unwearied British
geologist gives an account of a great portion of the east of
Europe.

280 (p. 83.)— Cuvier, Ossemens fossiles, 1821. torn. i. p.
157, 262, and 264. Vide Humboldt, iiber die Hochebene
von Bogota in der Deutchen Bierteljahrs-Schrift, 1839, Bd.
i. S. 117.

286 (p. 83.)— Journal of the Asiatic Society, No. xv. p. 109.

287 (p. 84.) — Bevrich, in Karsten's Archiv fiir Mineral-
ogie, 1844, Bd. xviii. S. 218.

288 (p. 84.) — Through the admirable labours of Count
Sternberg, Adolph Brongniart, Goppert, and Lindley.

28i» (p. 84.) — Vtde Robert Brown's Botany of Consro, p.
42, and the unfortunate d'Urville, in the Memoir: De la
distribution des Fougeres sur la surface du globe terrestre.

2^ (p. 81.)— To this belong the Cycadeie of the old coal
formation of Radnitz, Bohemia, discovered by Count Stern-
berg, and described l)y Corda. Two species, Cycadites et
Zamites Coniai, vide Goppert, fossile Cycadeen in den Ar-
beiten der Schles. Gesellschaft, fur valerl. Cultur im J
1843, S. 33, 40, and 50. In the coal formation of Koniga-
hiitte. Upper Silesia, a Cycadea (Pterophyllum gonorrha-
chis, Goep.) has also been found.

291 (p. 84.) -Lindley, Fossil Flora, No. xv. p. 16.^.^

292 (p. 84.)— Fossil Coniferae, in Buckland, Geology, p.
483—490. Mr. VVitham has the merit of having first de-
tected the existence of coniferse in the earlier vegetation of
the old coal formatifms. All the stems of trees discovered
in these formations had previously been regarded as pulms.
The species of the genus Araucarit.es, however, is not pe-
culiar to the coal fields of Great Britain ; they are also met
with in Upper Silesia.

293 (p. 84.) — Adolph Brongniart, Prodrome d'une Hi.st.
des Vegetaux fossiles, p. 176; Buckland, Geology, p. 479;
Endlicher and Unger, Grundziige der Botanik, 1843, S.455.

294 (p. 84.) — " By means of Lepidodendron a better pas-
sage is established from Flowering to Flowerle.ss Plants
than by either Equisetum or Cyras, or any other known
genus." — Lindley and Huiton, Fossil Flora, vol. ii. p. 53.

29t (p. 84.) — Kunth, Anordung der Pflanzenfamilien, in
his Handb. der Botanik, S. 307 and 314.

296 (p. 84.)— That fossil coal consists of vegetable fibres
carbonized not through fire, but in the moist way, and un-
der the co-agency of sulphuric acid, is vouched for particu-
larly by Goppert's able observations, of a piece of Amber-
tree wood converted into coal (vide Karsten, Archiv fffr
Mineralogie, Bd. xviii. S. 530). The coal lies close to the
wholly unaltered amber. On the part which the lower
vegetables may have had in the production of coal, vide
Link in the Abhandl. der Beriiuer Akademie der Wissen-
schaften, 1838, S. 38.

297 (p. 84.) — See the excellent paper of Chevandier, in
the Comptes rendus de I'Acad. des Sciences. 1844, torn.
xviii. pt. I. p. 285. In order to compare the half-inch thick
layer of carbonaceous matter with the coal strata, regard
must also be had to the enormous pressure which these
strata have suflfered from the superincumbent beds, and
which is even attested by the generally flattened form of
the fossil stems of trees that are dug up. " The wood-hills,
as they are called, of the southern shore of the island of
New Siberia, discovered in 1806 by Sirowatskoi, consist,
according to Hedenstrom, of elevations of about 30 fathoms,
made up of horizontal layers of sandstone interchangingly
with bituminous trunks of trees. On the tops of the hil-
locks the stems stand erect. The stratum of drift wood is

138

NOTES TO PRECEDING SECTION.

visible for five wersts." Vide Wrangel, Reise Iftngs der
Nonlkuste von Siberien in den Jahren 1220—1824, Th, i.
S. 202.

298 (p. 84.) — This corypha is the sopato (zoyatl, Aztekian)
or paima dulce of the natives ; vide Humboldt and Bon-
plfiud, Synopsis Plant, ^quihoct. Orbis Nwvi, torn. i. p. 302.
One deeply versed in the American langnag^es, Professor
Buschmann, observes that the palma soyate is also named
in Vepe's Vocabulario de la Leng-ua Othomi, and that the
Aztekian word zoyatl (Molina, Vocabulario) also occurs in
the local names zoyat.itlan and zoyapanco near Chiapa.

2!*^ (p. 85.)— Near Baracoa and' Cayos de Moa ; vide Ta-
gcbuch des Admirals vom 25 and 27 November, 1492, and
Humboldt, Examen critique de I'llist. de la Geogr. du Nou-
Teau Continent, tom. ii. p. 252, and torn. iii. p. 23. Colum-
i)us was so observant of all natural objects, that he distin-
guished— and was, indeed, the first to do so — Podocarpus
from Pinus. "I find," he says, "en la ticrra aspera del
Cibao pinos que no Uevan pinas [fir-tops or cones], pero por
tal orden compuestos por naturaleza, que (los frutos) pare-
ceu azeytunas del Axarafe de Sevilla." The great botanist,
Richard, when he produced his excellent work on the Cy-
ciideie and Coniferse, was not aware that long- before L'H6-
ritier, at the close of the I5th century, Podocarpus had al-
ready been distinguished from the pines — by a seafaring
man, too.

31)0 (p. 85.) — Charles Darwin, Journal of the Voyages of
the Adventure and Beagle, 1839, p. 271.

an (p. 85.) — Goppert describes other three Cycadeae
'species of Cicaditeie and Pterophyllum) from the lignitic
clay-shists of Altsattel and Commotau in Bohemia, perhaps
'rom the Eocene period (Goppert, in the work quoted in
Note 90).

302 (p. 85.)— Buckland, Geology, p. 509.

303 (p. 85.)— Leopold von Buch,'in Abhandl. der Akad. der
Wiss. zu Berlin aus den J. 1814—1815, S. 1(51, and in Pog-
^endorff's Annalen, Bd. ii. S. 575 ; Elie de Beaumont, in
Annales des Sciences nat. t. xix. p. 60.

304 (p. 86.) — Vide Elie de Beaumont, Descr. g^ol. de la
France, t. i. p. 65 ; Beudant, G6ologie, 1844, p. 209.

305 (p. 87.)— Transactions of the Cambridge Philosophi-
cal Society, vol. vi. pt. 2, 1837, p. 297. According to others,
as 100 : 284.

30ti (p. 87.) — In the middle ages the prevalent opinion
MIS that the sea covered but one seventh of the surface of
.ne globe, an opinion which Cardinal d'Ailly (Imago Mun-
di, cap. 8) founded on the Apocryphal 4th Book of Ezra.
Columbus, who always derived' much of his cosmological
Jinowledge 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" con-
tributed not a little. Vide Humboldt, Examen critique de
I'Hist. de la Geographic, t. i. p. 186.

307 (p. 87.) — Agathemeros, in Hudson, Geographi mi-
nbres, t. ii. p. 4. Vide Humboldt, Asie centr. t. i. p. 120,
125.

308 (p. 87.)— Strabo, lib. i. p. 65, Casaub, Vide Hum-
boldt, Examen crit. t. i. p. 152.

309 (p. 87.) — On the mean latitude of the Northern Asiatic
shores, and the true name of Cape Tairaura (Cape Siewero
— Wostotschnoi), and Cape North-East (Schalagskoi Mys"),
vide Humboldt, Asie centrale, t. iii. p. 35 and 37.

310 (p. 88.)— lb. t. i. p. 198—200. The southern point of
America and the Archipelago, which we call Terra del Fu-
ego, lies in the meridian of the north-western part of Baf-
fin's Bay, and of the great uncircumscribed polar land,
which perhaps belongs to West Greenland.

311 (p. 88.)— Strabo, lib. ii. p. 92 and 108, Casaub.

312 (p. 88.)— Humboldt, Asie centrale, t. iii. p. 25. I had
already, at an early period of my work, De distributione
geographica plantarum secundum coeli temperiem et altitu-
dinem montium, directed attention to the important influ-
ence of compact or divided continents on climate and hu-
man civilization: " Regiones vel per sinus lunatos in longa
cornua porrectae, angulosis littorum recessibus quasi mem-
bratim disccrptae, vel spatia patentia in immensum, quo-
rum littora nuUis incisa angulis ambit sine anfractu Ocea-
nus" (p. 81 and 182). On the relations of the extent of
coast to the area of a continent (at the same time as a
measure of the accessibility of the interior), vide the Inqui-
ries in Berghaus, Annalen der Erdkunde, Bd. xii. 1835, S.
490, and Physikal. Atlas, 1839, No. iii. S. 69.

313 (p. 88.)— Strabo, lib. ii. p. 92 and 198, Casaub.

314 (p. 88.)— Of Africa, Pliny says (v. 1.)—" Nee alia pars
terrarum pauciores recipit sinus." The small Indian pe-
ninsula this side the Ganges, in its triangular outline, pre-
sents another analogous form. In Ancient Greece there
prevailed an opinion of the regular configuration of the dry
land. There were four gulphs or bays, among which the
Persian was placed in opposition to the Hyrcanian (i. e. the
Caspian Sea) (Arrian, vii. 16 ; Plut. in vita Alexandri,cap,
44 ; Dionys. Perieg. v. 48 und 630, pag. 11 und 38, Bernh.)
These four bays and the isthmuses of the land, according
to the optical fancies of Agesianax, were reflected in the

moon (Plut. de Facie in Oifce Lunae, p. 921, 19). On thfl
terra quadrifida, or four divisions of the dry land, cf which
two lay north, two south of the equator, "wtde Macrobius,
Comm. in Somnium Scipionis, ii. 9. 1 have submitted this
portion of the geography of the ancients, on which great
confusion prevails, to a new and careful examinatitm, in
my Examen crit. de I'Hist. de la G6ogr. t. i. p. 119, 145^
180—185, as also in Asie centr. t. ii. p. 172—178.

315 (p. 88.) — Flcurieu, in Voyage de Merchand autour
du Monde, t. iv. p. 38—42.

3lt; (p. 88.)— Humboldt, in the Journal de Physique, t.
liii. 1799, p. 33, and Rel. hist. t. ii. p. 19, t. iii. p. 189 and
198.

317 (p. 88.) — Humboldt, in PoggendorfTs Annalen der
Physik, Bd. xl. S. 171. On the remarkable Fiord forma-
tion of the south-east end of America, vide Darwin's Jour-
nal (Narrative of the Voyages of the Adventure and Beagle,
vol. iii.) 1839, p. 266. The parallelism of the two mount-
ain chains is maintained from 5° North to 5° South latitude.
The change in the direction of the coast at Arica appears
to be a consequence of the altered course of the chasm upon
or through which the Andes have arisen.

318 (p. 89.) — De la Beche, Sections and Views illustrative
of Geological Phenomena, 1830, Tab. 40 ; Charles Babbage,
Observations on the Temple of Serapis at Pozzuoli, near
Naples, and on certain causes which may produce Geologi-
cal Cycles of great extent, 1834. A bed of sandstone, fivo
English miles thick, heated to 100° Fahr., would rise on
its surface about 25 feet. Clay strata heated, on the con-
trary, would occasion a contraction or sinking of the ground.
See the calculation for the secular rise of Sweden, on the
presumption of a rise by so small a quantity as 3° Reaum.,
in a stratum 140,000 feet thick, heated to the melting point,
in Bischoff, Wftrmelehre des Innern unseres Erdkorpers,
S. 303.

319 (p. 69.) — The presumption of the stability — which has
hitherto been so implicit — of the point of gravity, has at all
events been shaken to a certain extent by the gradual rise
of large portions of the earth's surface. Vide Bessel Uber
Maass und Gewicht, in Schumacher's Jahrbuch fiir 1840,
S. 134.

320 (p. 89.) - Th. ii. (1810), S. 389. Vide Hallstrom, in
Kongl. Vetenskaps-Academiens Ilandlingar (Stockh.), 1823,
p. 39 ; Lyell, in the Philos. Trans, for 1835, p. 1 ; Blom
(Amtmann in Budskerud), Stat. Beschr. von Norwegcn,
1843, S. 89—116. If not before Von Buch's travels through
Scandinavia, still before the publication of the account of
them, Playfair, in his Illustrations of the Huttonian Theo-
ry, () 393, as well as Keilhau (Om Landjordens Stigning in
Norge in dem Nyt Magazin for Naturvidenskaherene), «ud
even before Playfair, the Dane Jessen, had expressed au
opinion that it was not the sea which fell in level, but the
firm land of Sweden whijch rose : these ideas remained
wholly unknown to our great geologist, and exerted no in-
fluence on the progress of physical geography. Jessen, in
his work, Kougeriget Norge fremstillet efter nets naturiige
og borgerlige Tilstand, Kjcibenh. 1763, sought to explain
the changes in the relative levels of the land and soa, upon
the old notions of Celsius, Kalm, and Dahn. He broache.s
some confused notions about the possibility of an intern:il
growth of rocks, but finally declares himself in favour of an
upliftment of the land by earthquakes. "All along," he
observes, "no such rising was apparent immediately after
the earthquake of Egersund ; still, other causes producing
such an effect may have been brought into operation by it."

321 (p. 89.) — Berzelius, Jahresbericht iiberdie Fortschritie
der physischen Wiss. No. 18, S. 686. The island Saltholm,
over against Copenhagen, and Bornholm, however, rise but
very little — Bornholm scarcely 1 foot in a century ; vidn
Forchhammer, in Philos. Magazine. 3d Series, vol. ii. p. 3(.',).

322 (p. 89.)— KeilhEU, in Nyt Mag. for Naturvid. IS.%,
Bd. i. p. 105—254, Bd. ii. p. 57 ; Bravais, sur les ligms
d'ancien niveau de la Mer, 1843, p. 15— 40. See also Dar-
win on the Parallel Roads of Glen-Roy and Lochaber, in
the Philos. Transactions for 1839, p. 60.

323 (p. 89.)— Humboldt, Asie centrale, t. ii. p. 319—321,
t. iii. p. 549 — 554. The depression of the Dead Sea has
been again and again determined by the barometrical meas-
urements of Count Bertou, the more careful ones of Rus-
segger, and the trigonometrical survey of Lieut. Symoiul,
of the Royal Navy, who specifies 1506 feet as the difference
of level between the surface of the Dead Sea and the high-
est houses in Jaffa. Mr. Alderson, who communicated this
result to the Geographical Society of London, in a letter,
of the contents of which I was informed by my friend Cap-
tain Washington, Mr. Alderson then imagined (Nov. 28.
1841) that the Dead Sea layabout 1314 feet under the level
of the Mediterranean. In another and later communica-
tion from Lieut. Symond (Jameson's Edinburgh New Phil-
osophical Journal, vol. xxxiv. 1843, p. 178), as a final r*>.
suit, two trigonometrical operati-ons are detailed, which
agree remarkably with each other, and assign 1231 feet
(Paris measure) as the depression of the level of the Dead
Sea below that of the Mediterranean.

mmmmmmmmm ... . , .."Pl^

INTERESTING WORKS

JUST F'UBLISHED BY

HARPER & BROTHERS, NEW-YORK.

THE NEW REFORMATION.

N«W SEJLa>r^ WITS dVAIOUS ILi^VSTRATITE PLATS, PBICE 35 CENTa, OR MUSLIM, 87| eSffTS.

JOHN RONGE,

THE HOLY COAT OF TREVES,

AND THE NEW GERMAN CATHOLIC CHURCH.

fackidiijff airt^eHtic details of Ae events «(nmeeted with the recent erkibitiea of the prertended "-Coet of ow Lard" in
the Cutbednd of IVevee, during the months of August and September, 1844 : comprising the letters and protestations of
the author against the imposition and superstitions of the Roman CathoKc priests, &c.

This pnblication is exceedingly ^>porttuie : it will be permsed with deep imtereat by the Protestant eammamtf at
large. — Oommercisl Advertiser.

The noble protest of Ronge has been circulated in Germany, not by thoasands, but by millions of copies ; and it has been
hailed with loud applause by all classes, because it «z{«esse6 a pubMe sentiment, and finds a re£3)onse in all heart*.—
New- York Obs

PILGRIMAGE TO TREVES.

nr ONE VOtHME ISmO, WtAUTOrUlLT PRUrTEB, PRIOB 75 CEWTS.

A PILGRIMAGE TO TREVES,

TIReuei TIE f IIIEI 8F TEE lEDSE, 1N6 TIE FOREST OF ABDfiNHES.

BY CHARLES EDWARD ANTHON, ESQ.

This is the production sf a young AiBerican who had the rare foTtnne ie be present ut the most marveflo'is oecorrence
of the 19th centUTy— the exhibition of the Holy Robe. In addition to a very graphic description of this ejctraordinary
event, which, fro« the excitement it has created, seems destined te be an era in the ChTistian Church, this unpretend-
ing volume is replete with antiquarian lore, relating to the city of Charlemagne, from which the " Pilgnmage" cemmen-
ees — the intermediate historic and poetic ground ; and of the once renowned city of Treves, with which i* eloses. It is the
work of a scholar, and cannot fail to enlist a profound interest.— Oateeg'O Advertiser.

EUGENE SUE'S GREAT WORK.

HARPER & BROTHERS

HAVE JUST PUBLISHED, NEATLY PRINTED, IN PAPER COVER, NEW AND CHEAP

EDITION ©F VOLUME L, COMPRISING THE FIRST EIGBT NUMBERS, BEING

ABOUT HALF THE ENTIRE WORK OF

THE WANDERING JEW.

BY EUGENE SUE.

PRIGS ONZiT TWZ!2>arTT-rZVS CENTS.

In order to render this chefd^muvre of modern French fiction, which is now
rapidly approaching its completic universally accessible, Harper & Broth-
ers have determined on issuing a new edition, reduced in price to the lowest
possible advance over the actual cost of its publication. No work of modern
times has attracted such a prodigious amount of readers in all parts of the
civilized world as this extraordinary production, which is redolent with scenes
of the most intense and thrilling interest, incomparably more vivid, artistic, and
dramatic than may be found in most works of its class.

PREPARING FOR EARLY PUBLICATION-

TO BE ISSUED IN NUMBERS, BLESANTLY PRINTED ON THE FINEST PAPER,

AN ILLUSTRATED EDITION

or

THE WANDERING JEW.

Embellished by numerous beautifully-executed engravings on wood, after
the splendid originals by the first artists of Paris.

HARPER & BROTHERS, PUBLISHERS, NEW- YORK.