Transcriber's Notes: Words in italics in the original are surrounded by
_underscores_. Depending on the font, there is one character that may
not be visible. It is a superscripted "5". Other notes follow the text.
_Barr's Buffon._
Buffon's Natural History.
CONTAINING
A THEORY OF THE EARTH,
A GENERAL
_HISTORY OF MAN_,
OF THE BRUTE CREATION, AND OF
VEGETABLES, MINERALS,
_&c. &c._
FROM THE FRENCH.
WITH NOTES BY THE TRANSLATOR.
IN TEN VOLUMES.
VOL. I.
London:
PRINTED FOR THE PROPRIETOR,
AND SOLD BY H. D. SYMONDS, PATERNOSTER-ROW.
1797.
CONTENTS
OF
THE FIRST VOLUME.
_Page_
_THE Theory of the Earth_ 1
Proof of the Theory of the Earth.
Article I. _On the Formation of the Planets_ 69
Article II. _From the System of Whiston_ 115
Article III. _From the System of Burnet_ 128
Article IV. _From the System of Woodward_ 131
Article V. _Exposition of some other Systems_ 137
Article VI. _Geography_ 155
Article VII. _On the Production of the Strata, or Beds of
the Earth_ 183
Article VIII. _On Shells and other Marine Productions found
in the interior Parts of the Earth_ 219
Article IX. _On the Inequalities of the Surface
of the Earth_ 262
Article X. _Of Rivers_ 298
PREFACE.
We should certainly be guilty of a gross absurdity if, in an age like
the present, we were to enter into an elaborate discussion on the
advantages to be derived from the study of NATURAL HISTORY; the ancients
recommended it as useful, instructive, and entertaining; and the moderns
have so far pursued and cultivated this first of sciences, that it is
now admitted to be the source of universal instruction and knowledge;
where every active mind may find subjects to amuse and delight, and the
artist a never failing field to enrich his glowing imagination.
It would have been singular if, on such a subject, a number of authors
had not submitted the produce of their observations and labour; many
have written upon Natural Philosophy, but the Comte de BUFFON stands
eminently distinguished among them; he has entered into a minute
investigation, and drawn numberless facts from unwearied observations
far beyond any other, and this he has accomplished in a style fully
accordant with the importance of his subject. Ray, Linnæus, Rheaumur,
and other of his cotemporaries, deserve much credit for their classing
of animals, vegetables, &c. but it was BUFFON alone who entered into a
description of their nature, habits, uses, and properties. In his Theory
of the Earth he has displayed a wonderful ingenuity, and shewn the
general order of Nature with a masterly hand, although he may be subject
to some objections for preferring physical reasonings on general
causes, rather than allowing aught to have arisen from supernatural
agency, or the will of the Almighty. In this he has followed the example
of all great philosophers, who seem unwilling to admit that the
formation of any part of the Universe is beyond their comprehension.
As the works of this Author will best speak for themselves, we shall
avoid unnecessary panegyric, hoping they will have received no material
injury in the following translation; we shall therefore content
ourselves with observing, that in our plan we have followed that adopted
by the Comte himself in a latter edition, from which he exploded his
long and minute treatises on anatomy and mensuration; though elegant and
highly finished in themselves, they appeared to us of too abstruse and
confined a nature for general estimation, and which we could not have
gone into without almost doubling the expence; a circumstance we had to
guard against, for the advantage of those of our readers to whom that
part would have been totally uninteresting.
As to this edition, we presume it is no vain boast, that every exertion
has been made to do justice to a work of such acknowledged merit. In the
literary part, it has been the Proprietor's chief endeavour to preserve
the spirit and accuracy of the Author, as far as could be done in
translating from one language into another; and it is with gratitude he
acknowledges, that those endeavours have been amply supported by the
engraver; for the decorative executions of MILTON will remain a lasting
monument of his abilities, as long as delicacy in the arts is held in
estimation.
BUFFON's
NATURAL HISTORY.
_THE THEORY OF THE EARTH._
Neither the figure of the earth, its motion, nor its external
connections with the rest of the universe, pertain to our present
investigation. It is the internal structure of the globe, its
composition, form, and manner of existence which we purpose to examine.
The general history of the earth should doubtless precede that of its
productions, as a necessary study for those who wish to be acquainted
with Nature in her variety of shapes, and the detail of facts relative
to the life and manners of animals, or to the culture and vegetation of
plants, belong not, perhaps, so much to Natural History, as to the
general deductions drawn from the observations that have been made upon
the different materials which compose the terrestrial globe: as the
heights, depths, and inequalities of its form; the motion of the sea,
the direction of mountains, the situation of rocks and quarries, the
rapidity and effects of currents in the ocean, &c. This is the history
of nature in its most ample extent, and these are the operations by
which every other effect is influenced and produced. The theory of these
effects constitutes what may be termed a primary science, upon which the
exact knowledge of particular appearances as well as terrestrial
substances entirely depends. This description of science may fairly be
considered as appertaining to physics; but does not all physical
knowledge, in which no system is admitted, form part of the History of
Nature?
In a subject of great magnitude, whose relative connections are
difficult to trace, and where some facts are but partially known, and
others uncertain and obscure, it is more easy to form a visionary
system, than to establish a rational theory; thus it is that the Theory
of the Earth has only hitherto been treated in a vague and hypothetical
manner; I shall therefore but slightly mention the singular notions of
some authors who have written upon the subject.
The first hypothesis I shall allude to, deserves to be mentioned more
for its ingenuity than its reasonable solidity; it is that of an English
astronomer, (WHISTON) versed in the system of NEWTON, and an
enthusiastic admirer of his philosophy; convinced that every event which
happens on the terrestrial globe, depends upon the motions of the stars,
he endeavours to prove, by the assistance of mathematical calculations,
that the tail of a comet has produced every alteration the earth has
ever undergone.
The next is the formation of an heterodox theologician, (BURNET) whose
brain was so heated with poetical visions, that he imagined he had seen
the creation of the universe. After explaining what the earth was in its
primary state, when it sprung from nothing; what changes were occasioned
by the deluge; what it has been and what it is, he then assumes a
prophetic style, and predicts what will be its state after the
destruction of the human race.
The third comes from a writer (WOODWARD) certainly a better and more
extensive observer of nature than the two former, though little less
irregular and confused in his ideas; he explains the principal
appearances of the globe, by an immense abyss in the bowels of the
earth, which in his opinion is nothing more than a thin crust that
serves as a covering to the fluid it incloses.
The whole of these hypotheses are raised on unstable foundations; have
given no light upon the subject, the ideas being unconnected, the facts
confused, and the whole confounded with a mixture of physic and fable;
and consequently have been adopted only by those who implicitly believe
opinions without investigation, and who, incapable of distinguishing
probability, are more impressed with the wonders of the marvellous than
the relation of truth.
What we shall say on this subject will doubtless be less extraordinary,
and appear unimportant, if put in comparison with the grand systems just
mentioned, but it should be remembered that it is an historian's
business to describe, not invent; that no suppositions should be
admitted upon subjects that depend upon facts and observation; that his
imagination ought only to be exercised for the purpose of combining
observations, rendering facts more general, and forming one connected
whole, so as to present to the mind a distinct arrangement of clear
ideas and probable conjectures; I say probable, because we must not
expect to give exact demonstration on this subject, that being confined
to mathematical sciences, while our knowledge in physics and natural
history depends solely upon experience, and is confined to reasoning
upon inductions.
In the history of the Earth, we shall therefore begin with those facts
that have been obtained from the experience of time, together with what
we have collected by our own observations.
This immense globe exhibits upon its surface heights, depths, plains,
seas, lakes, marshes, rivers, caverns, gulphs, and volcanos; and upon
the first view of these objects we cannot discover in their dispositions
either order or regularity. If we penetrate into its internal part, we
shall there find metals, minerals, stones, bitumens, sands, earths,
waters, and matters of every kind, placed as it were by chance, and
without the smallest apparent design. Examining with a more strict
attention, we discover sunk mountains, caverns filled, rocks split and
broken, countries swallowed up, and new islands rising from the ocean;
we shall also perceive heavy substances placed above light ones, hard
bodies surrounded with soft; in short, we shall there find matter in
every form, wet and dry, hot and cold, solid and brittle, mixed in such
a sort of confusion as to leave room to compare them only to a mass of
rubbish and the ruins of a wrecked world.
We inhabit these ruins however with a perfect security. The various
generations of men, animals, and plants, succeed each other without
interruption; the earth produces fully sufficient for their subsistence;
the sea has its limits; its motions and the currents of air are
regulated by fixed laws: the returns of the seasons are certain and
regular; the severity of the winter being constantly succeeded by the
beauties of the spring: every thing appears in order, and the earth,
formerly a CHAOS, is now a tranquil and delightful abode, where all is
animated, and regulated by such an amazing display of power and
intelligence as fills us with admiration, and elevates our minds with
the most sublime ideas of an all-potent and wonderful Creator.
Let us not then draw any hasty conclusions upon the irregularities of
the surface of the earth, nor the apparent disorders in the interior
parts, for we shall soon discover the utility, and even the necessity of
them; and, by considering them with a little attention, we shall,
perhaps, find an order of which we had no conception, and a general
connection that we could neither perceive nor comprehend, by a slight
examination: but in fact, our knowledge on this subject must always be
confined. There are many parts of the surface of the globe with which we
are entirely unacquainted, and have but partial ideas of the bottom of
the sea, which in many places we have not been able to fathom. We can
only penetrate into the coat of the earth; the greatest caverns and the
deepest mines do not descend above the eight thousandth part of its
diameter, we can therefore judge only of the external and mere
superficial part; we know, indeed, that bulk for bulk the earth weighs
four times heavier than the sun, and we also know the proportion its
weight bears with other planets; but this is merely a relative
estimation; we have no certain standard nor proportion; we are so
entirely ignorant of the real weight of the materials, that the internal
part of the globe may be a void space, or composed of matter a thousand
times heavier than gold; nor is there any method to make further
discoveries on this subject; and it is with the greatest difficulty any
rational conjectures can be formed thereon.
We must therefore confine ourselves to a correct examination and
description of the surface of the earth, and to those trifling depths to
which we have been enabled to penetrate. The first object which presents
itself is that immense quantity of water which covers the greatest part
of the globe; this water always occupies the lowest ground, its surface
always level, and constantly tending to equilibrium and rest;
nevertheless it is kept in perpetual agitation by a powerful agent,
which opposing its natural tranquillity, impresses it with a regular
periodical motion, alternately raising and depressing its waves,
producing a vibration in the total mass, by disturbing the whole body to
the greatest depths. This motion we know has existed from the
commencement of time, and will continue as long as the sun and moon,
which are the causes of it.
By an examination of the bottom of the sea, we discover that to be fully
as irregular as the surface of the earth; we there find hills and
vallies, plains and cavities, rocks and soils of every kind: we there
perceive that islands are only the summits of vast mountains, whose
foundations are at the bottom of the Ocean; we also find other mountains
whose tops are nearly on a level with the surface of the water, and
rapid currents which run contrary to the general movement: they
sometimes run in the same direction, at others, their motions are
retrograde, but never exceeding their bounds, which appear to be as
fixed and invariable as those which confine the rivers of the earth. In
one part we meet with tempestuous regions, where the winds blow with
irresistible fury, where the sea and the heavens equally agitated, join
in contact with each other, are mixed and confounded in the general
shock: in others, violent intestine motions, tumultuous swellings,
water-spouts, and extraordinary agitations, caused by volcanos, whose
mouths though a considerable depth under water, yet vomit fire from the
midst of the waves, and send up to the clouds a thick vapour, composed
of water, sulphur, and bitumen. Further we perceive dreadful gulphs or
whirlpools, which seem to attract vessels, merely to swallow them up. On
the other hand, we discover immense regions, totally opposite in their
natures, always calm and tranquil, yet equally dangerous; where the
winds never exert their power, where the art of the mariner becomes
useless, and where the becalmed voyager must remain until death relieves
him from the horrors of despair. In conclusion, if we turn our eyes
towards the northern or southern extremities of the globe, we there
perceive enormous flakes of ice separating themselves from the polar
regions, advancing like huge mountains into the more temperate climes,
where they dissolve and are lost to the sight.
Exclusive of these principal objects the vast empire of the sea abounds
with animated beings, almost innumerable in numbers and variety. Some of
them, covered with light scales, move with astonishing celerity; others,
loaded with thick shells, drag heavily along, leaving their track in the
sand; on others Nature has bestowed fins, resembling wings, with which
they raise and support themselves in the air, and fly to considerable
distances; while there are those to whom all motion has been denied, who
live and die immoveably fixed to the same rock: every species, however,
find abundance of food in this their native element. The bottom of the
sea, and the shelving sides of the various rocks, produce great
abundance of plants and mosses of different kinds; its soil is composed
of sand, gravel, rocks, and shells; in some parts a fine clay, in others
a solid earth, and in general it has a complete resemblance to the land
which we inhabit.
Let us now take a view of the earth. What prodigious differences do we
find in different climates? What a variety of soils? What inequalities
in the surface? but upon a minute and attentive observation we shall
find the greatest chain of mountains are nearer the equator than the
poles; that in the Old Continent their direction is more from the east
to west than from the north to south; and that, on the contrary, in the
New World they extend more from north to south than from east to west;
but what is still more remarkable, the form and direction of those
mountains, whose appearance is so very irregular, correspond so
precisely, that the prominent angles of one mountain are always
opposite to the concave angles of the neighbouring mountain, and are of
equal dimensions, whether they are separated by a small valley or an
extensive plain. I have also observed that opposite hills are nearly of
the same height, and that, in general, mountains occupy the middle of
continents, islands, and promontories, which they divide by the greatest
lengths.
In following the courses of the principal rivers, I have likewise found
that they are almost always perpendicular with those of the sea into
which they empty themselves; and that in the greatest part of their
courses they proceed nearly in the direction of the mountains from which
they derive their source.
The sea shores are generally bounded with rocks, marble, and other hard
stones, or by earth and sand which has accumulated by the waters from
the sea, or been brought down by the rivers; and I observe that opposite
coasts, separated only by an arm of the sea, are composed of similar
materials, and the beds of the earth are exactly the same. Volcanos I
find exist only in the highest mountains; that many of them are entirely
extinct; that some are connected with others by subterraneous passages,
and that their explosions frequently happen at one and the same time.
There are similar correspondences between certain lakes and neighbouring
seas; some rivers suddenly disappear, and seem to precipitate themselves
into the earth. We also find internal, or mediterranean seas, constantly
receiving an enormous quantity of water from a number of rivers without
ever extending their bounds, most probably discharging by subterraneous
passages all their superfluous supplies. Lands which have been long
inhabited are easily distinguished from those new countries where the
soil appears in a rude state, where the rivers are full of cataracts,
where the earth is either overflowed with water, or parched up with
drought, and where every spot upon which a tree will grow is covered
with uncultivated woods.
Pursuing our examination in a more extensive view, we find that the
upper strata that surrounds the globe, is universally the same. That
this substance which serves for the growth and nourishment of animals
and vegetables, is nothing but a composition of decayed animal and
vegetable bodies reduced into such small particles, that their former
organization is not distinguishable; or penetrating a little further,
we find the real earth, beds of sand, lime-stone, argol, shells, marble,
gravel, chalk, &c. These beds are always parallel to each other and of
the same thickness throughout their whole extent. In neighbouring hills
beds of the same materials are invariably found upon the same levels,
though the hills are separated by deep and extensive intervals. All beds
of earth, even the most solid strata, as rocks, quarries of marble, &c.
are uniformly divided by perpendicular fissures; it is the same in the
largest as well as smallest depths, and appears a rule which nature
invariably pursues.
In the very bowels of the earth, on the tops of mountains, and even the
most remote parts from the sea, shells, skeletons of fish, marine
plants, &c. are frequently found, and these shells, fish, and plants,
are exactly similar to those which exist in the Ocean. There are a
prodigious quantity of petrified shells to be met with in an infinity of
places, not only inclosed in rocks, masses of marble, lime-stone, as
well as in earth and clays, but are actually incorporated and filled
with the very substance which surrounds them. In short, I find myself
convinced, by repeated observations, that marbles, stones, chalks,
marls, clay, sand, and almost all terrestrial substances, wherever they
may be placed, are filled with shells and other substances, the
productions of the sea.
These facts being enumerated, let us now see what reasonable conclusions
are to be drawn from them.
The changes and alterations which have happened to the earth, in the
space of the last two or three thousand years, are very inconsiderable
indeed, when compared with those important revolutions which must have
taken place in those ages which immediately followed the creation; for
as all terrestrial substances could only acquire solidity by the
continued action of gravity, it would be easy to demonstrate that the
surface of the earth was much softer at first than it is at present, and
consequently the same causes which now produce but slight and almost
imperceptible changes during many ages, would then effect great
revolutions in a very short space. It appears to be a certain fact, that
the earth which we now inhabit, and even the tops of the highest
mountains, were formerly covered with the sea, for shells and other
marine productions are frequently found in almost every part; it appears
also that the water remained a considerable time on the surface of the
earth, since in many places there have been discovered such prodigious
banks of shells, that it is impossible so great a multitude of animals
could exist at the same time: this fact seems likewise to prove, that
although the materials which composed the surface of the earth were then
in a state of softness, that rendered them easy to be disunited, moved
and transported by the waters, yet that these removals were not made at
once; they must indeed have been successive, gradual, and by degrees,
because these kind of sea productions are frequently met with more than
a thousand feet below the surface, and such a considerable thickness of
earth and stone could not have accumulated but by the length of time. If
we were to suppose that at the Deluge all the shell-fish were raised
from the bottom of the sea, and transported over all the earth; besides
the difficulty of establishing this supposition, it is evident, that as
we find shells incorporated in marble and in the rocks of the highest
mountains, we must likewise suppose that all these marbles and rocks
were formed at the same time, and that too at the very instant of the
Deluge; and besides, that previous to this great revolution there were
neither mountains, marble, nor rocks, nor clays, nor matters of any kind
similar to those we are at present acquainted with, as they almost all
contain shells and other productions of the sea. Besides, at the time of
the Deluge, the earth must have acquired a considerable degree of
solidity, from the action of gravity for more than sixteen centuries,
and consequently it does not appear possible that the waters, during the
short time the Deluge lasted, should have overturned and dissolved its
surface to the greatest depths we have since been enabled to penetrate.
But without dwelling longer on this point, which shall hereafter be more
amply discussed, I shall confine myself to well-known observations and
established facts. There is no doubt but that the waters of the sea at
some period covered and remained for ages upon that part of the globe
which is now known to be dry land; and consequently the whole continents
of Asia, Europe, Africa, and America, were then the bottom of an ocean
abounding with similar productions to those which the sea at present
contains: it is equally certain that the different strata which compose
the earth are parallel and horizontal, and it is evident their being in
this situation is the operation of the waters which have collected and
accumulated by degrees the different materials, and given them the same
position as the water itself always assumes. We observe that the
position of strata is almost universally horizontal: in plains it is
exactly so, and it is only in the mountains that they are inclined to
the horizon, from their having been originally formed by a sediment
deposited upon an inclined base. Now I insist that these strata must
have been formed by degrees, and not all at once, by any revolution
whatever, because strata, composed of heavy materials, are very
frequently found placed above light ones, which could not be, if, as
some authors assert, the whole had been mixed with the waters at the
time of the Deluge, and afterwards precipitated; in that case every
thing must have had a very different appearance to that which now
exists. The heaviest bodies would have descended first, and each
particular stratum would have been arranged according to its weight and
specific gravity, and we should not see solid rocks or metals placed
above light sand any more than clay under coal.
We should also pay attention to another circumstance; it confirms what
we have said on the formation of the strata; no other cause than the
motions and sediments of water could possibly produce so regular a
position of it, for the highest mountains are composed of parallel
strata as well as the lowest plains, and therefore we cannot attribute
the origin and formation of mountains to the shocks of earthquakes, or
eruptions of volcanos. The small eminences which are sometimes raised by
volcanos, or convulsive motions of the earth, are not by any means
composed of parallel strata, they are a mere disordered heap of matters
thrown confusedly together; but the horizontal and parallel position of
the strata must necessarily proceed from the operations of a constant
cause and motion, always regulated and directed in the same uniform
manner.
From repeated observations, and these incontrovertible facts, we are
convinced that the dry part of the globe, which is now habitable, has
remained for a long time under the waters of the sea, and consequently
this earth underwent the same fluctuations and changes which the bottom
of the ocean is at present actually undergoing. To discover therefore
what formerly passed on the earth, let us examine what now passes at
the bottom of the sea, and from thence we shall soon be enabled to draw
rational conclusions with regard to the external form and internal
composition of that which we inhabit.
From the Creation the sea has constantly been subject to a regular flux
and reflux: this motion, which raises and falls the waters twice in
every twenty-four hours, is principally occasioned by the action of the
moon, and is much greater under the equator than in any other climates.
The earth performs a rapid motion on its axis, and consequently has a
centrifugal force, which is also the greatest at the equator; this
latter, independent of actual observation, proves that the earth is not
perfectly spherical, but that it must be more elevated under the equator
then at the poles.
From these combined causes, the ebbing and flowing of the tides, and the
motion of the earth, we may fairly conclude, that although the earth was
a perfect sphere in its original form, yet its diurnal motion, together
with the constant flux and reflux of the sea, must, by degrees, in the
course of time, have raised the equatorial parts, by carrying mud,
earth, sand, shells, &c. from other climes, and there depositing of
them. Agreeable to this idea the greatest irregularities must be found,
and, in fact, are found near the equator. Besides, as this motion of the
tides is made by diurnal alternatives, and been repeated, without
interruption, from the commencement of time, is it not natural to
imagine, that each time the tide flows the water carries a small
quantity of matter from one place to another, which may fall to the
bottom like a sediment, and form those parallel and horizontal strata
which are every where to be met with? for the whole motion of the water,
in the flux and reflux, being horizontal, the matters carried away with
them will naturally be deposited in the same parallel direction.
But to this it may be said, that as the flux and reflux of the waters
are equal and regularly succeed, two motions would counterpoise each
other, and the matters brought by the flux would be returned by the
reflux, and of course this cause for the formation of the strata must be
chimerical; that the bottom of the sea could not experience any material
alteration by two uniform motions, wherein the effects of the one would
be regularly destroyed by the other; much less could they change the
original form by the production of heights and inequalities.
To which it may be answered, that the alternate motions of the waters
are not equal, the sea having a constant motion from the east to the
west, besides, the agitation, caused by the winds, opposes and prevents
the equality of the tides. It will also be admitted, that by every
motion of which the sea is susceptible, particles of earth and other
matters will be carried from one place and deposited in another; and
these collections will necessarily assume the form of horizontal and
parallel strata, from the various combinations of the motions of the sea
always tending to move the earth, and to level these materials wherever
they fall, in the form of a sediment. But this objection is easily
obviated by the well-known fact, that upon all coasts, bordering the
sea, where the ebbing and flowing of the tide is observed, the flux
constantly brings in a number of things which the reflux does not carry
back. There are many places upon which the sea insensibly gains and
gradually covers over, while there are others from which it recedes,
narrowing as it were its limits, by depositing earth, sands, shells,
&c. which naturally take an horizontal position; these matters
accumulate by degrees in the course of time, and being raised to a
certain point gradually exclude the water, and so become part of the dry
land for ever after.
But not to leave any doubt upon this important point, let us strictly
examine into the possibility of a mountain's being formed at the bottom
of the sea by the motions and sediments of the waters. It is certain
that on a coast which the sea beats with violence during the agitation
of its flow, that every wave must carry off some part of the earth; for
wherever the sea is bounded by rocks, it is a plain fact that the water
by degrees wears away those rocks, and consequently carries away small
particles every time the waves retire; these particles of earth and
stone will necessarily be transported to some distance, and being
arrived where the agitation of the water is abated, and left to their
own weight, they precipitate to the bottom in form of a sediment, and
there form a first stratum, either horizontal or inclined, according to
the position of the surface upon which they fall; this will shortly be
covered by a similar stratum produced by the same cause, and thus will a
considerable quantity of matter be almost insensibly collected
together, and the strata of which will be placed, parallel to each
other.
This mass will continue to increase by new sediments, and by gradually
accumulating, in the course of time become a mountain at the bottom of
the sea, exactly similar to those we see on dry land, both as to outward
form and internal composition. If there happen to be shells in this part
of the sea, where we have supposed this deposit to be made, they will be
filled and covered with the sediment, and incorporated in the deposited
matter, making a part of the whole mass, and they will be found situated
in the parts of the mountain according to the time they had been there
deposited; those that lay at the bottom, previous to the formation of
the first stratum, will be found in the lowest, and so according to the
time of their being deposited, the latest in the most elevated parts.
So likewise, when the bottom of the sea, at particular places, is
troubled by the agitation of the water, there will necessarily ensue, in
the same manner, a removal of earth, shells, and other matters, from the
troubled to other parts; for we are assumed by all divers, that at the
greatest depths they descend, i. e. twenty fathoms, the bottom of the
sea is so troubled by the agitation of the waters, that the mud and
shells are carried to considerable distances, consequently
transportations of this kind are made in every part of the sea, and this
matter falling must form eminences, composed like our mountains, and in
every respect similar; therefore the flux and reflux, by the winds, the
currents, and all the motions of the water, must inevitably create
inequalities at the bottom of the sea.
Nor must we imagine that these matters cannot be transported to great
distances, because we daily see grain, and other productions of the East
and West Indies, arriving on our own coasts.[25:A] It is true these
bodies are specifically lighter than water, whereas the substances of
which we have been speaking are specifically heavier; but, however,
being reduced to an impalpable powder, they may be sustained a long time
in the water so as to be conveyed to considerable distances.
It has been supposed that the sea is not troubled at the bottom,
especially if it is very deep, by the agitations produced by the winds
and tides; but it should be recollected that the whole mass, however
deep, is put in motion by the tides, and that in a liquid globe this
motion would be communicated to the very centre; that the power which
produces the flux and reflux is a penetrating force, which acts
proportionably upon every particle of its mass, so that we can determine
by calculation the quantity of its force at different depths; but, in
short, this point is so certain, that it cannot be contested but by
refusing the evidence of reason.
Therefore, we cannot possibly have the least doubt that the tides, the
winds, and every other cause which agitates the sea, must produce
eminences and inequalities at the bottom, and those heights must ever be
composed of horizontal or equally inclined strata. These eminences will
gradually encrease until they become hills, which will rise in
situations similar to the waves that produce them; and if there is a
long extent of soil, they will continue to augment by degrees; so that
in course of time they will form a vast chain of mountains. Being formed
into mountains, they become an obstacle to and interrupt the common
motion of the sea, producing at the same time other motions, which are
generally called currents. Between two neighbouring heights at the
bottom of the sea a current will necessarily be formed, which will
follow their common direction, and, like a river, form a channel, whose
angles will be alternately opposite during the whole extent of its
course. These heights will be continually increasing, being subject only
to the motion of the flux, for the waters during the flow will leave the
common sediment upon their ridges; and those waters which are impelled
by the current will force along with them, to great distances, those
matters which would be deposited between both, at the same time
hollowing out a valley with corresponding angles at their foundation. By
the effects of these motions and sediments the bottom of the sea,
although originally smooth, must become unequal, and abounding with
hills and chains of mountains, as we find it at present. The soft
materials of which the eminences are originally composed will harden by
degrees with their own weight; some forming parts, purely angular,
produce hills of clay; others, consisting of sandy and crystalline
particles, compose those enormous masses of rock and flint from whence
crystal and other precious stones are extracted; those formed with stony
particles, mixed with shells, form those of lime-stone and marble,
wherein we daily meet with shells incorporated; and others, compounded
of matter more shelly, united with pure earth, compose all our beds of
marle and chalk. All these substances are placed in regular beds, and
all contain heterogeneous matter; marine productions are found among
them in abundance, and nearly according to the relation of their
specific weights; the lightest shells in chalk, and the heaviest in clay
and lime-stone; these shells are invariably filled with the matter in
which they have been inclosed, whether stones or earth; an incontestible
proof that they have been transported with the matter that fills and
surrounds them, and that this matter was at that time in an impalpable
powder. In short, all those substances whose horizontal situations have
been established by the level of the waters of the sea, will constantly
preserve their original position.
But here it may be observed, that most hills, whose summits consist of
solid rocks, stone, or marble, are formed upon small eminences of much
lighter materials, such for instance as clay, or strata of sand, which
we commonly find extended over the neighbouring plains, upon which it
may be asked, how, if the foregoing theory be just, this seemingly
contradictory arrangement happens? To me this phenomenon appears to be
very easy and naturally explained. The water at first acts upon the
upper stratum of coasts, or bottom of the sea, which commonly consists
of clay or sand, and having transported this, and deposited the
sediment, it of course composes small eminences, which form a base for
the more heavy particles to rest upon. Having removed the lighter
substances, it operates upon the more heavy, and by constant attrition
reduces them to an impalpable powder; which it conveys to the same spot,
and where, being deposited, these stony particles, in the course of
time, form those solid rocks and quarries which we now find upon the
tops of hills and mountains. It is not unlikely that as these particles
are much heavier than sand or clay, that they were formerly a
considerable depth under a strata of that kind, and now owe their high
situations to having been last raised up and transported by the motion
of the water.
To confirm what we here assert, let us more closely investigate the
situation of those materials which compose the superficial outer part of
the globe, indeed the only part with which we have any knowledge. The
different beds of strata in stone quarries are almost all horizontal, or
regularly inclined; those whose foundations are on clays or other solid
matters are clearly horizontal, especially in plains. The quarries
wherein we find flint, or brownish grey free-stone, in detached
portions, have a less regular position, but even in those the uniformity
of nature plainly appears, for the horizontal or regularly inclined
strata are apparent in quarries where these stones are found in great
masses. This position is universal, except in quarries where flint and
brown free-stone are found in small detached portions, the formation of
which we shall prove to have been posterior to those we have just been
treating of; for granite, vitrifiable sand, argol, marble, calcareous
stone, chalk, and marles, are always deposited in parallel strata,
horizontally or equally inclined; the original formation of these are
easily discovered, for the strata are exactly horizontal and very thin,
and are arranged above each other like the leaves of a book. Beds of
sand, soft and hard clay, chalk, and shells, are also either horizontal
or regularly inclined. Strata of every kind preserves the same thickness
throughout its whole extent, which often occupies the space of many
miles, and may be traced still farther by close and exact observations.
In a word, the materials of the globe, as far as mankind have been
enabled to penetrate, are arranged in an uniform position, and are
exactly similar.
The strata of sand and gravel which have been washed down from mountains
must in some measure be excepted; in vallies they are sometimes of a
considerable extent, and are generally placed under the first strata of
the earth; in plains, they are as even as the most ancient and interior
strata, but near the bottom and upon the ridges of hills they are
inclined, and follow the inclination of the ground upon which they have
flowed. These being formed by rivers and rivulets, which are constantly
in vallies changing their beds, and dragging these sands and gravel with
them, they are of course very numerous. A small rivulet flowing from the
neighbouring heights, in the course of time will be sufficient to cover
a very spacious valley with a strata of sand and gravel, and I have
often observed in hilly countries, whose base, as well as the upper
stratum, was hard clay, that above the source of the rivulet the clay is
found immediately under the vegetable soil, and below it there is the
thickness of a foot of sand upon the clay, and which extends itself to a
considerable distance. These strata formed by rivers are not very
ancient, and are easily discovered by the inequality of their thickness,
which is constantly varying, while the ancient strata preserves the same
dimensions throughout; they are also to be known by the matter itself,
which bears evident marks of having been smoothed and rounded by the
motions of the water. The same may be said of the turf and perished
vegetables which are found below the first stratum of earth in marshy
grounds; they cannot be considered as ancient, but entirely produced by
successive heaps of decayed trees and other plants. Nor are the strata
of slime and mud, which are found in many countries, to be considered as
ancient productions, having been formed by stagnated waters or
inundations of rivers, and are neither so horizontal, nor equally
inclined, as the strata anciently produced by the regular motions of the
sea. In the strata formed by rivers we constantly meet with river, but
scarcely ever sea shells, and the few that are found are broken and
irregularly placed; whereas in the ancient strata there are no river
shells; the sea shells are in great quantities, well preserved, and all
placed in the same manner, having been transported at the same time and
by the same cause. How are we to account for this astonishing
regularity? Instead of regular strata, why do we not meet with the
matters that compose the earth jumbled together, without any kind of
order? Why are not rocks, marbles, clays, marles, &c. variously
dispersed, or joined by irregular or vertical strata? Why are not the
heaviest bodies uniformly found placed beneath the lightest? It is easy
to perceive that this uniformity of nature, this organization of earth,
this connection of different materials, by parallel strata, without
respect to their weights, could only be produced by a cause as powerful
and constant as the motion of the sea, whether occasioned by the regular
winds or by that of the flux and reflux, &c.
These causes act with greater force under the equator than in other
climates, for there the winds are more regular and the tides run
higher; the most extensive chains of mountains are also near the
equator. The mountains of Africa and Peru are the highest known, they
frequently extend themselves through whole provinces, and stretch, to
considerable distances under the ocean. The mountains of Europe and
Asia, which extend from Spain to China, are not so high as those of
South America and Africa. The mountains of the North, according to the
relation of travellers, are only hills in comparison with those of the
Southern countries. Besides, there are very few islands in the Northern
Seas, whereas in the torrid zone they are almost innumerable, and as
islands are only the summits of mountains, it is evident that the
surface of the earth has many more inequalities towards the equator than
in the northerly climes.
It is therefore evident that the prodigious chain of mountains which run
from the West to the East in the old continent, and from the North to
the South in the new, must have been produced by the general motion of
the tides; but the origin of all the inferior mountains must be
attributed to the particular motions of currents, occasioned by the
winds and other irregular agitations of the sea: they may probably have
been produced by a combination of all those motions, which must be
capable of infinite variations, since the winds and different positions
of islands and coasts change the regular course of the tides, and compel
them to flow in every possible direction: it is, therefore, not in the
least astonishing that we should see considerable eminences, whose
courses have no determined direction. But it is sufficient for our
present purpose to have demonstrated that mountains are not the produce
of earthquakes, or other accidental causes, but that they are the
effects resulting from the general order of nature, both as to their
organization and the position of the materials of which they are
composed.
But how has it happened that this earth which we and our ancestors have
inhabited for ages, which, from time immemorial, has been an immense
continent, dry and removed from the reach of the waters, should, if
formerly the bottom of the ocean, be actually larger than all the
waters, and raised to such a height as to be distinctly separated from
them? Having remained so long on the earth, why have the waters now
abandoned it? What accident, what cause could produce so great a
change? Is it possible to conceive one possessed of sufficient power to
produce such an amazing effect?