Buffon's Natural History, Volume 01 (of 10)
by comte de Georges Louis Leclerc Buffon · English · Gutenberg #44792 · 420,884 chars · public domain (US)
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Title: Buffon's Natural History, Volume 01 (of 10)
Author: comte de Georges Louis Leclerc Buffon
Editor: James Smith Barr
Release date: January 29, 2014 [eBook #44792]
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Language: English
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_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?
These questions are difficult to be resolved, but as the facts are
certain and incontrovertible, the exact manner in which they happened
may remain unknown, without prejudicing the conclusions that may be
drawn from them; nevertheless, by a little reflection, we shall find at
least plausible reasons for these changes. We daily observe the sea
gaining ground on some coasts and losing it on others; we know that the
ocean has a continued regular motion from East to West; that it makes
loud and violent efforts against the low lands and rocks which confine
it; that there are whole provinces which human industry can hardly
secure from the rage of the sea; that there are instances of islands
rising above, and others being sunk under the waters. History speaks of
much greater deluges and inundations. Ought not this to incline us to
believe that the surface of the earth has undergone great revolutions,
and that the sea may have quitted the greatest part of the earth which
it formerly covered? Let us but suppose that the old and new worlds were
formerly but one continent, and that the Atlantis of Plato was sunk by
a violent earthquake; the natural consequence would be, that the sea
would necessarily have flowed in from all sides, and formed what is now
called the Atlantic Ocean, leaving vast continents dry, and possibly
those which we now inhabit. This revolution, therefore, might be made of
a sudden by the opening of some vast cavern in the interior part of the
globe, which an universal deluge must inevitably succeed; or possibly
this change was not effected at once, but required a length of time,
which I am rather inclined to think; however these conjectures may be,
it is certain the revolution has occurred, and in my opinion very
naturally; for to judge of the future, as well as the past, we must
carefully attend to what daily happens before our eyes. It is a fact
clearly established by repeated observations of travellers, that the
ocean has a constant motion from the East to West; this motion, like the
trade winds, is not only felt between the tropics, but also throughout
the temperate climates, and as near the poles as navigators have gone;
of course the Pacific Ocean makes a continual effort against the coasts
of Tartary, China, and India; the Indian Ocean acts against the east
coast of Africa; and the Atlantic in like manner against all the eastern
coasts of America; therefore the sea must have always and still
continues to gain land on the east and lose it on the west; and this
alone is sufficient to prove the possibility of the change Of earth into
sea, and sea into land. If, in fact, such are the effects of the sea's
motion from east to west, may we not very reasonably suppose that Asia
and the eastern continent is the oldest country in the world, and that
Europe and part of Africa, especially the western coasts of these
continents, as Great Britain, France, Spain, Muratania, &c. are of a
more modern date? Both history and physics agree in confirming this
conjecture.
There are, however, many other causes which concur with the continual
motion of the sea from east to west, in producing these effects.
In many places there are lands lower than the level of the sea, and
which are only defended from it by an isthmus of rocks, or by banks and
dykes of still weaker materials; these barriers must gradually be
destroyed by the constant action of the sea, when the lands will be
overflowed, and constantly make part of the ocean. Besides, are not
mountains daily decreasing by the rains, which loosen the earth, and
carry it down into the vallies? It is also well known that floods wash
the earth from the plains and high grounds into the small brooks and
rivers, which in their turn convey it into the sea. By these means the
bottom of the sea is filling up by degrees, the surface of the earth
lowering to a level, and nothing but time is necessary for the sea's
successively changing places with the earth.
I speak not here of those remote causes which stand above our
comprehension; of those convulsions of nature, whose least effects would
be fatal to the world; the near approach of a comet, the absence of the
moon, the introduction of a new planet, &c. are suppositions on which it
is easy to give scope to the imagination. Such causes would produce any
effects we chose, and from a single hypothesis of this nature, a
thousand physical romances might be drawn, and which the authors might
term, THE THEORY OF THE EARTH. As historians we reject these vain
speculations; they are mere possibilities which suppose the destruction
of the universe, in which our globe, like a particle of forsaken matter,
escapes our observation, and is no longer an object worthy regard; but
to preserve consistency, we must take the earth as it is, closely
observing every part, and by inductions judge of the future from what
exists at present; in other respects we ought not to be affected by
causes which seldom happen, and whose effects are always sudden and
violent; they do not occur in the common course of nature; but effects
which are daily repeated, motions which succeed each other without
interruption, and operations that are constant, ought alone to be the
ground of our reasoning.
We will add some examples thereto; we will combine particular effects
with general causes, and give a detail of facts which will render
apparent, and explain the different changes that the earth has
undergone, whether by the eruption of the sea upon the land, or by
retiring from that which it had formerly covered.
The greatest eruption was certainly that which gave rise to the
Mediterranean sea. The ocean flows through a narrow channel between two
promontories with great rapidity, and then forms a vast sea, which,
without including the Black sea, is about seven times larger than the
kingdom of France. Its motion through the straits of Gibraltar is
contrary to all other straits, for the general motion of the sea is from
east to west, but in that alone it is from the west to the east, which
proves that the Mediterranean sea is not an ancient gulph, but that it
has been formed by an eruption, produced by some accidental cause; as an
earthquake which might swallow up the earth in the strait, or by a
violent effort of the ocean, caused by the wind, which might have forced
its way through the banks between the promontories of Gibraltar and
Ceuta. This opinion is authorised by the testimony of the ancients, who
declare in their writings, that the Mediterranean sea did not formerly
exist; and confirmed by natural history and observations made on the
opposite coasts of Spain, where similar beds of stones and earth are
found upon the same levels, in like manner as they are in two mountains,
separated by a small valley.
The ocean having forced this passage, it ran at first through the
straits with much greater rapidity than at present, and overflowed the
continent that joined Europe to Africa. The waters covered all the low
countries, of which we can only now perceive the tops of some of the
considerable mountains, such as parts of Italy, the islands of Sicily,
Malta, Corsica, Sardinia, Cyprus, Rhodes, and those of the Archipelago.
In this eruption I have not included the Black sea, because the quantity
of water it receives from the Danube, Nieper, Don, and various other
rivers, is fully sufficient to form and support it; and besides, it
flows with great rapidity through the Bosphorus into the Mediterranean.
It might also be presumed that the Black and Caspian seas were formerly
only two large lakes, joined by a narrow communication, or by a morass,
or small lake, which united the Don and the Wolga near Tria, where these
two rivers flow near each other; nor is it improbable that these two
seas or lakes were then of much greater extent, for the immense rivers
which fall into the Black and Caspian seas may have brought down a
sufficient quantity of earth to shut up the communication, and form that
neck of land by which they are now separated; for we know great rivers,
in the course of time, fill up seas and form new land, as the province
at the mouth of the Yellow river in China; Louisania at the mouth of the
Mississippi, and the northern part of Egypt, which owes its existence to
the inundations of the Nile; the rapidity of which brings down such
quantities of earth from the internal parts of Africa, as to deposit on
the shores, during the inundations, a body of slime and mud of more than
fifty feet in depth. The province of the Yellow river and Louisania
have, in like manner, been formed by the soil from the rivers.
The Caspian sea is actually a real lake; having no communication with
other seas, not even with the lake Aral, which seems to have been a part
of it, being only separated from it by a large track of sand, in which
neither rivers nor canals for communication the waters have as yet been
found. This sea, therefore, has no external communication with any
other; and I do not know that we are authorised to suspect that it has
an internal one with the Black sea, or with the Gulph of Persia. It is
true the Caspian sea receives the Wolga and many other rivers, which
seem to furnish it with more water than is lost by evaporation; but
independent of the difficulty of such calculation, if it had a
communication with any other sea, a constant and rapid current towards
the opening would have marked its course, and I never heard of any such
discovery being made; travellers of the best credit affirm to the
contrary, and consequently the Caspian sea must lose by evaporation just
as much water as it receives from the Wolga and other rivers.
Nor is it any improbable conjecture that the Black sea will at some
period be separated from the Mediterranean; and that the Bosphorus will
be shut up, whenever the great rivers shall have accumulated a
sufficient quantity of earth to answer that effect; this may be the case
in the course of time by the successive diminution of waters in rivers,
in proportion as the mountains from whence they draw their sources are
lowered by the rains, and those other causes we have just alluded to.
The Caspian and Black seas must therefore be looked upon rather as lakes
than gulphs of the ocean, for they resemble other lakes which receive a
number of rivers without any apparent outlet, such as the Dead sea,
many lakes in Africa and other places. These two seas are not near so
salt as the Mediterranean or the ocean; and all voyagers affirm that the
navigation in the Black and Caspian seas, upon account of its
shallowness and quantity of rocks and quicksands, is so extremely
dangerous, that only small vessels can be used with safety which farther
proves they must not be looked upon as gulphs of the ocean, but as
immense bodies of water collected from great rivers.
A considerable eruption of the sea would doubtless take place upon the
earth, if the isthmus which separates Africa from Asia was divided, as
the Kings of Egypt, and afterwards the Caliphs projected; and I do not
know that the communication between the Red sea and Mediterranean is
sufficiently established, as the former must be higher than the latter.
The Red sea is a narrow branch of the ocean, and does not receive into
it a single river on the side of Egypt, and very few on the opposite
coast; it will not therefore be subject to diminution, like those seas
and lakes which are constantly receiving slime and sand from those
rivers that flow into them. The ocean supplies the Red sea with all its
water, and the motion of the tides is very evident in it, of course it
must be affected by every movement of the ocean. But the Mediterranean
must be lower than the ocean, because the current passes with great
rapidity through the straits; besides, it receives the Nile, which flows
parallel to the west coast of the Red sea, and which divides Egypt, a
very low country; from all which it appears probable, that the Red sea
is higher than the Mediterranean, and that if the isthmus of Suez was
cut through, there Would be a great inundation, and a considerable
augmentation of the Mediterranean would ensue; at least if the waters
were not restrained by dykes and sluices placed at proper distances, and
which was most likely the case if the ancient canal of communication
ever had existence.
Without dwelling longer upon conjectures, which, although well founded,
may appear hazardous and rash, we shall give some recent and certain
examples of the change of the sea into land, and the land into sea. At
Venice the bottom of the Adriatic is daily rising, and if great care had
not been taken to clean and empty the canals, the whole would long
since have formed part of the continent; the same may be said of most
ports, bays, and mouths of rivers. In Holland the bottom of the sea has
risen in many places; the gulph of Zuyderzee and the strait of the Texel
cannot receive such large vessels as formerly. At the mouth of all
rivers we find small islands, and banks of sand and earth brought down
by the waters, and it is certain the sea will be filled up in every part
where great rivers empty themselves. The Rhine is lost in the sands
which itself accumulated. The Danube and the Nile, and all great rivers,
after bringing down much sand and earth, no longer come to the sea by a
single channel; they divide into different branches, and the intervals
are filled up by the materials they have themselves brought thither.
Morasses daily dry up; lands forsaken by the sea are cultivated; we
navigate countries now covered by waters; in short, we see so many
instances of land changing into water, and water into land, that we must
be convinced of these alterations having, and will continue to take
place; so that in time gulphs will become continents; isthmusses,
straits; morasses, dry lands; and the tops of our mountains, the shoals
of the sea.
Since then the waters have covered, and may successively cover, every
part of the present dry land, our surprise must cease at finding every
where marine productions and compositions, which could only be the works
of the waters. We have already explained how the horizontal strata of
the earth were formed, but the perpendicular divisions that are commonly
found in rocks, clays, and all matters of which the globe is composed,
still remain to be considered. These perpendicular stratas are, in fact,
placed much farther from each other than the horizontal, and the softer
the matter the greater the distance; in marble and hard earths they are
frequently found only a few feet; but if the mass of rock be very
extensive, then these fissures are at some fathoms distant; sometimes
they descend from the top of the rock to the bottom, and sometimes
terminate at an horizontal fissure. They are always perpendicular in the
strata of calcinable matters, as chalk, marle, marble, &c. but are more
oblique and irregularly placed in vitrifiable substances, brown
freestone, and rocks of flint, where they are frequently adorned with
chrystals, and other minerals. In quarries of marble or calcinable
stone, the divisions are filled with spar, gypsum, gravel, and an earthy
sand, which contains a great quantity of chalk. In clay, marls, and
every other kind of earth, excepting turf, these perpendicular divisions
are either empty or filled with such matters as the water has
transported thither.
We need seek very little farther for the cause and origin of those
perpendicular cracks. The materials by which the different strata are
composed being carried by the water, and deposited as a kind of
sediment, must necessarily, at first, contain a considerable share of
water, the which, as they began to harden, they would part with by
degrees, and, as they must necessarily lessen in the course of drying,
that decrease would occasion them to split at irregular distances. They
naturally split in a perpendicular direction, because in that direction
the action of gravity of one particle upon another has no actual effect,
while, on the contrary, it is directly opposite in a horizontal
situation; the diminution of bulk therefore could have no sensible
effect but in a vertical line. I say it is the diminution of drying, and
not the contained water forcing a place to issue, is the cause of these
perpendicular fissures, for I have often observed that the two sides of
those fissures answer throughout their whole height, as exactly as two
sides of a split piece of wood; their insides are rough and irregular,
whereas if they had been made by the motion of the water, they would
have been smooth and polished; therefore these cracks must be produced
suddenly and at once or by degrees in drying, like the flaws in wood,
and the greatest part of the water they contained evaporated through the
pores. The divisions of these perpendicular cracks vary greatly as to
the extent of their openings; some of them being not more than half an
inch, others increasing to one or two feet; there are some many fathoms,
and which form those precipices so often met with in the Alps and other
high mountains. The small ones are produced by drying alone, but those
which extend to several feet are the effects of other causes; for
instance, the sinking of the foundation on one side while the other
remains unmoved; if the base sinks but a line or two, it is sufficient
to produce openings of many feet in a rock of considerable height.
Sometimes rocks, which are founded on clay or sand, incline to one
side, by which motion the perpendicular cracks become extended.
I have not yet mentioned those large openings which are found in rocks
and mountains; they must have been produced by great sinkings, as of
immense caverns, unable longer to support the weight with which they
were encumbered, but these intervals are very different from
perpendicular fissures; they appear to be vacancies opened by the hand
of Nature for the communication of nations. In this manner all vacancies
in large mountains and divisions, by straits in the sea, seem to present
themselves; such as the straits of Thermopylæ, the ports of Caucasus,
the Cordeliers, the extremity of the straits of Gibraltar, the entrance
of the Hellespont, &c. These could not have been occasioned by the
simple separation by drying of matter, but by considerable parts of the
lands themselves being sunk, swallowed up, or overturned.
These great sinkings, though produced by accidental causes, hold a first
place in the principal circumstances in the History of the Earth, and
not a little contributed to change the face of the Globe; the greatest
part of them have been produced by subterraneous fires, whose
explosions cause earthquakes and volcanos; the force of these inflamed
and confined matters in the bowels of the earth is beyond compare; by it
cities have been swallowed up, provinces overturned, and mountains
overthrown. But however great this force may be, and prodigious as the
effects appear, we cannot assent to the opinion of those authors who
suppose these subterraneous fires proceed from an immense abyss of flame
in the centre of the earth, neither give we credit to the common notion
that they proceed from a great depth below the surface of the earth, air
being absolutely necessary for the support of inflammation. In examining
the materials which issue from volcanos, even in the most violent
eruptions, it appears very plain, that the furnace of the inflamed
matters is not at any great depth, as they are similar to those found in
mountains, disfigured only by the calcination, and the melting of the
metallic parts which they contain; and to be convinced that the matters
cast out by volcanos do not come from any great depth, we have only to
consider of the height of the mountain, and judge of the immense force
that would be necessary to cast up stones and minerals to the height of
half a league; for Ætna, Hecla, and many other volcanos have at least
that elevation from the plains. Now it is perfectly well known that the
action of fire is equal in every direction; it cannot therefore act
upwards, with a force capable of throwing large stones half a league
high, without an equal re-action downwards, and on the sides, and which
re-action must very soon pierce and destroy the mountain on every side,
because the materials which compose it are not more dense and firm than
those thrown out; how then can it be imagined that the cavity, which
must be considered as the type or cannon, could resist so great a force
as would be necessary to raise those bodies to the mouth of the volcano?
Besides, if this cavity was deeper, as the external orifice is not
great, it would be impossible for so large a quantity of inflamed and
liquid matter to issue out at once, without clashing against each other,
and against the sides of the tube, and by passing through so long a
space they would run the chance of being extinguished and hardened. We
often see rivers of bitumen and melted sulphur, thrown out of the
volcanos with stones and minerals, flow from the tops of the mountains
into the plains; is it natural to imagine that matters so fluid, and so
little able to resist violent action, should be elevated from any great
depth? All the observations that can be made on this subject will prove
that the fire of the volcano is not far from the summit of the mountain,
and that it never descends to the level of the plain.
This idea of volcanos does not, however, render it inconsistent that
they are the cause of earthquakes, and that their shocks may be felt on
the plains to very considerable distances; nor that one volcano may not
communicate with another by means of subterraneous passages; but it is
of the depth of the fire's confinement that we now speak, and which can
only be at a small distance from the mouth of the volcano. It is not
necessary to produce an earthquake on a plain, that the bottom of the
volcano should be below the level of that plain; nor that there should
be internal cavities filled with the same combustible matter, for a
violent explosion, such as generally attends an eruption, may, like that
of a powder magazine give so great a shock by its re-action, as to
produce an earthquake that might be felt at a considerable distance.
I do not mean to say that there are no earthquakes produced by
subterraneous fires, but merely that there are some which proceed only
from the explosion of volcanos. In confirmation of what has been
advanced on this subject, it is certain that volcanos are seldom met
with on plains; on the contrary, they are constantly found in the
highest mountains, and their mouths at the very summit of them. If the
internal fires of the volcanos extended below the plains, would not
passages be opened in them during violent eruptions? In the first
eruption would not these fires rather have pierced the plains, where, by
comparison, the resistance must be infinitely weaker, than force their
way through a mountain more than half a league in height.
The reason why volcanos appear alone in mountains, is, because much
greater quantities of minerals, sulphur, and pyrites, are contained in
mountains, and more exposed than in the plains; besides which, those
high places are more subject to the impressions of air, and receive
greater quantities of rain and damps, by which mineral substances are
capable of being heated and fermented into an absolute state of
inflammation.
In short, it has often been observed, that, after violent eruptions, the
mountains have shrunk and diminished in proportion to the quantity of
matter which has been thrown out; another proof that the volcanos are
not situated at the bottom of the mountain, but rather at no great
distance from the summit itself.
In many places earthquakes have formed considerable hollows, and even
separations in mountains; all other inequalities have been produced at
the same time with the mountains themselves by the currents of the sea,
for in every place where there has not been a violent convulsion, the
strata of the mountains are parallel, and their angles exactly
correspond. Those subterraneous caverns which have been produced by
volcanos are easily to be distinguished from those formed by water; for
the water, having washed away the sand and clay with which they are
filled, leaves only the stones and rocks, and this is the origin of
caverns upon hills; while those found upon the plains are commonly
nothing but ancient pits and quarries, such as the salt quarries of
Maestricht, the mines of Poland, &c. But natural caverns belong to
mountains: they receive the water from the summit and its environs, from
whence it issues over the surface wherever it can obtain a passage; and
these are the sources of springs and rivers, and whenever a cavern is
filled by any part falling in, an inundation generally ensues.
From what we have related, it is easy to be seen how much subterraneous
fires contribute to change the surface and internal part of the globe.
This cause is sufficiently powerful to produce very great effects: but
it is difficult to conceive how the winds should occasion any sensible
alterations upon the earth. The sea appears to be their empire, and
indeed, excepting the tides, nothing has so powerful an influence upon
the ocean; even the flux and reflux move in an uniform manner, and their
effects are regularly the same; but the action of the winds is
capricious and violent; they sometimes rush on with such impetuosity,
and agitate the sea with such violence, that from a calm, smooth, and
tranquil plain, it becomes furrowed with waves rolling mountains high,
and dashing themselves to pieces against the rocks and shores. The winds
cause constant alterations on the surface of the sea, but the surface of
the land, which has so solid an appearance, we should suppose would not
be subject to similar effects; by experience, however, it is known that
the winds raise mountains of sand in Arabia and Africa; and that they
cover plains with it; they frequently transport sand to great distances,
and many miles into the sea, where they accumulate in such quantities as
to form banks, downs, and even islands. It is also known that hurricanes
are the scourge of the Antilles, Madagascar, and other countries, where
they act with such fury, as to sweep away trees, plants, and animals,
together with the soil which gave them subsistence: they cause rivers to
ascend and descend, and produce new ones; they overthrow rocks and
mountains; they make holes and gulphs on the earth, and entirely change
the face of those unfortunate countries where they exist. Happily there
are but few climates exposed to the impetuosity of those dreadful
agitations of the air.
But the greatest and most general changes in the surface of the earth
are produced by rains, floods, and torrents from the high lands. Their
origins proceed from the vapours which the sun raises above the surface
of the ocean, and which the wind transports through every climate. These
vapours, which are sustained in the air, and conveyed at the will of the
winds, are stopped in their progress by the tops of the hills which they
encounter, where they accumulate until they become clouds and fall in
the form of rain, dew, or snow. These waters at first descend upon the
plains without any fixed course, but by degrees hollow out a bed for
themselves; by their natural bent they run to the bottom of mountains,
and penetrating or dissolving the land easiest to divide, they carry
earth and sand away with them, cut deep channels in the plains, form
themselves into rivers, and open a passage into the sea, which
constantly receives as much water from the land rivers as it loses by
evaporation. The windings in the channels of rivers have sinuosities,
whose angles are correspondent to each other, so that where the waves
form a saliant angle on one side, the other has an exactly opposite one;
and as hills and mountains, which may be considered as the banks of the
vallies which separate them, have also sinuosities in corresponding
angles, it seems to demonstrate that the vallies have been formed, by
degrees, by the currents of the sea, in the same manner as the rivers
have hollowed out their beds on the earth.
The waters which run on the surface of the earth, and support its
verdure and fertility, are not perhaps one half of those which the
vapours produce; for there are many veins of water which sink to great
depths in the internal part of the earth. In some places we are certain
to meet with water by digging; in others, not any can be found. In
almost all vallies and low grounds water is certain to be met with at
moderate depths; but, on the contrary, in all high places it cannot be
extracted from the bowels of the earth, but must be collected from the
heavens. There are countries of great extent where a spring cannot be
found, and where all the water which supplies the inhabitants and
animals with drink is contained in pools and cisterns. In the east,
especially in Arabia, Egypt, and Persia, wells are extremely scarce, and
the people have been obliged to make reservoirs of a considerable extent
to collect the waters as it falls from the heavens. These works,
projected and executed from public necessity, are the most beautiful and
magnificent monuments of the eastern nations; some of the reservoirs
occupy a space of two square miles, and serve to fertilize whole
provinces, by means of baths and small rivulets that let it out on every
side. But in low countries, where the greatest rivers flow, we cannot
dig far from the surface, without meeting with water, and in fields
situate in the environs of rivers it is often obtained by a few strokes
with a pick-axe.
The water, found in such quantities in low grounds, comes principally
from the neighbouring hills and eminences; at the time of great rains or
sudden melting of snow, a part of the water flows on the surface, but
most of it penetrates through the small cracks and crevices it finds in
the earth and rocks. This water springs up again to the surface wherever
it can find vent; but it often filters through the sand until it comes
to a bottom of clay or solid earth, where it forms subterraneous lakes,
rivulets, and perhaps rivers, whose courses are entirely unknown; they
must, however, follow the general laws of nature, and constantly flow
from the higher grounds to the lower, and consequently these
subterraneous waters must, in the end, fall into the sea, or collect in
some low place, either on the surface or in the interior part of the
earth; for there are several lakes into which no rivers enter, nor from
which there are not any issue; and a much greater number, which do not
receive any considerable river, that are the sources of the greatest
rivers on earth; such as the lake of St. Laurence; the lake Chiamè,
from whence spring two great rivers that water the kingdoms of Asam and
Pegu; the lake of Assiniboil in America; those of Ozera in Muscovy, that
give rise to the river Irtis, and a great number of others. These lakes,
it is evident, must be produced by the waters from the high lands
passing through subterraneous passages, and collecting in the lowest
places. Some indeed have asserted that lakes are to be found on the
summit of the highest mountains; but to this no credit can be given, for
those found on the Alps, and other elevated places, are all surrounded
by much more lofty mountains, and derive their origin from the waters
which run down the sides, or are filtered through those eminences in the
same manner as the lakes in the plains obtain their sources from the
neighbouring hills which overtop them.
It is apparent, therefore, that lakes have existence in the bowels of
the earth, especially under large plains and extensive vallies.
Mountains, hills, and all eminences have either a perpendicular or
inclined situation, and are exposed on all sides; the waters which fall
on their summits, after having penetrated into the earth, cannot fail,
from the declivity of the ground, of finding issue in many places, and
breaking in forms out of springs and fountains, and consequently there
will be little, if any water, remain in the mountains. On the contrary,
in plains, as the water which filters through the earth can find no
vent, it must collect in subterraneous caverns, or be dispersed and
divided among sand and gravel. It is these waters which are so
universally diffused through low grounds. The bottom of a pit or well is
nothing else but a kind of bason into which the waters that issue from
the adjoining lands insinuate themselves, at first falling drop by drop,
but afterwards, as the passages are opened, it receives supplies from
greater distances, and then continually runs in little streams or rills;
from which circumstance, although we can find water in any part of a
plain, yet we can obtain a supply but for a certain number of wells,
proportionate to the quantity of water dispersed, or rather to the
extent of the higher lands from whence they come.
It is unnecessary to dig below the level of the river to find water; it
is generally met with at much less depths, and there is no appearance
that waters of rivers filter far through the earth. The origin of waters
found in the earth below the level of rivers is not to be attributed to
them; for in rivers or torrents which are dried up, or whose courses
have been turned, we find no greater quantity of water by digging in
their beds than in the neighbouring lands at an equal depth.
A piece of land of five or six feet in thickness is sufficient to
contain water, and prevent it from escaping; and I have often observed
that the banks of brooks and pools are not sensibly wet at six inches
distance from the water.
It is true that the extent of the filtration is in proportion as the
soil is more or less penetrable; but if we examine the standing pools
with sandy bottoms, we shall perceive the water confined in the small
compass it had hollowed itself, and the moisture spread but a very few
inches; even in vegetable earth it has no great extent, which must be
more porous than sand or hard soil. It is a certain fact, that in a
garden we may almost inundate one bed without those nearly adjoining
feeling any moisture from it[65:A]. I have examined pieces of garden
ground, eight or ten feet thick, which had not been stirred for many
years, and whose surface was nearly level, and found that the rain water
never penetrated deeper than three or four feet; and on turning it up in
the spring, after a wet winter, I found it as dry as when first heaped
together.
I made the same observation on earth which had laid in ridges two
hundred years; below three or four feet it was as dry as dust; from
which it is plain that water does not extend so far by filtration as has
been generally imagined.
By this means, therefore, the internal part of the earth can be supplied
with a very small part; but water by its own weight descends from the
surface to the greatest depths; it sinks through natural conduits, or
penetrates small passages for itself; it follows the roots of trees, the
cracks in rocks, the interstices in the earth, and divides and extends
on all sides into an infinity of small branches and rills, always
descending until its passage is opposed by clay or some solid body,
where it continues collecting, and at length breaks out in form of
springs upon the surface.
It would be very difficult to make an exact calculation of the quantity
of subterraneous waters which have no apparent vent. Many have pretended
that it greatly surpasses all the waters that are on the surface of the
earth.
Without mentioning those who have advanced that the interior part of the
globe is entirely filled with water, there are some who believe there
are an infinity of floods, rivulets, and lakes in the bowels of the
earth. But this opinion does not seem to be properly founded, and it is
more probable that the quantity of subterraneous water, which never
appears on the surface, is not very considerable; for if these
subterraneous rivers are so very numerous, why do we never see any of
their mouths forcing their way through the surface? Besides, rivers, and
all running waters, produce great alterations on the surface of the
earth; they transport the soil, wear away the most solid rocks, and
displace all matters which oppose their passage. It would certainly be
the same in subterraneous rivers; the same effects would be produced;
but no such alterations have ever as yet been observed; the different
strata remains parallel, and every where preserves its original
position; and it is but in a very few places that any considerable
subterraneous veins of water have been discovered. Thus water in the
internal part of the earth, though great, acts but in a small degree, as
it is divided in an infinity of little streams, and retained by a number
of obstacles; and being so generally dispersed, it gives rise to many
substances totally different from primitive matters, both in form and
organization.
From all these observations we may fairly conclude, that it is the
continual motion of the flux and reflux of the sea which has produced
mountains, vallies, and other inequalities on the surface of the earth;
that it is the currents of the ocean which have hollowed vallies, raised
hills, and given them corresponding directions; that it is those waters
of the sea which, by transporting earth, &c. and depositing them in
horizontal layers, have formed the parallel strata; that it is the
waters from heaven, which by degrees destroy the effects of the sea, by
continually lowering the summit of mountains, filling up vallies, and
stopping the mouths of gulphs and rivers, and which, by bringing all to
a level, will, in the course of time, return this earth to the sea,
which, by its natural operations, will again form new continents,
containing vallies and mountains exactly similar to those which we at
present inhabit.
FOOTNOTES:
[25:A] Particularly Scotland and Ireland.
[65:A] These facts are so easily demonstrated, that the smallest
observation will prove their veracity.
PROOF
OF
_THE THEORY OF THE EARTH_.
ARTICLE I.
ON THE FORMATION OF THE PLANETS.
Our subject being Natural History, we would willingly dispense with
astronomical observations; but as the nature of the earth is so closely
connected with the heavenly bodies, and such observations being
calculated to illustrate more fully what has been said, it is necessary
to give some general ideas of the formation, motion, figure of the earth
and other planets.
The earth is a globe of about three thousand leagues diameter; it is
situate one thousand millions of leagues from the sun, around which it
makes its revolution in three hundred and sixty-five days. This
revolution is the result of two forces; the one may be considered as an
impulse from right to left, or from left to right, and the other an
attraction from above downwards, or beneath upwards, to a common centre.
The direction of these two forces, and their quantities, are so nicely
combined and proportioned, that they produce an almost uniform motion in
an ellipse, very near to a circle. Like the other planets the earth is
opaque, it throws out a shadow; it receives and reflects the light of
the sun, round which it revolves in a space of time proportioned to its
relative distance and density. It also turns round its own axis once in
twenty-four hours, and its axis is inclined 66-1/4 degrees on the plane
of the orbit. Its figure is spheroidical, the two axes of which differ
about 160th part from each other, and the smallest axis is that round
which the revolution is made.
These are the principal phenomena of the earth, the result of
discoveries made by means of geometry, astronomy, and navigation. We
shall not here enter into the detail of the proofs and observations by
which those facts have been ascertained, but only make a few remarks to
clear up what is still doubtful, and at the same time give our ideas
respecting the formation of the planets, and the different changes thro'
which it is possible they have passed before they arrived at the state
we at present see them.
There have been so many systems and hypotheses framed upon the formation
of the terrestrial globe, and the changes which it has undergone, that
we may presume to add our conjectures to those who have written upon the
subject, especially as we mean to support them with a greater degree of
probability than has hitherto been done: and we are the more inclined to
deliver our opinion upon this subject, from the hope that we shall
enable the reader to pronounce on the difference between an hypothesis
drawn from possibilities, and a theory founded in facts; between a
system, such as we are here about to present, on the formation and
original state of the earth, and a physical history of its real
condition, which has been given in the preceding discourse.
Galileo having found the laws of falling bodies, and Kepler having
observed that the area described by the principal planets in moving
round the sun, and those of the satellites round the planets to which
they belong, are proportionable to the time of their revolutions, and
that such periods were also in proportion to the square roots of the
cubes of their distances from the sun, or principal planets. Newton
found that the force which caused heavy bodies to fall on the surface of
the earth, extended to the moon, and retained it in its orbit; that this
force diminished in the same proportion as the square of the distance
increased, and consequently that the moon is attracted by the earth;
that the earth and planets are attracted by the sun; and that in general
all bodies which revolve round a centre, and describe areas proportioned
to the times of their revolution, are attracted towards that point. This
power, known by the name of GRAVITY, is therefore diffused throughout
all matter; planets, comets, the sun, the earth, and all nature, is
subject to its laws, and it serves as a basis to the general harmony
which reigns in the universe. Nothing is better proved in physics than
the actual existence of this power in every material substance.
Observation has confirmed the effects of this power, and geometrical
calculations have determined the quantity and relations of it.
This general cause being known, the effects would easily be deduced from
it, if the action of the powers which produce it were not too
complicated. A single moment's reflection upon the solar system will
fully demonstrate the difficulties that have attended this subject; the
principal planets are attracted by the sun, and the sun by the planets;
the satellites are also attracted by their principal planets, and each
planet attracts all the rest, and is attracted by them. All these
actions and reactions vary according to the quantities of matter and the
distances, and produce great inequalities and irregularities. How is so
great a number of connections to be combined and estimated? It appears
almost impossible in such a crowd of objects to follow any particular
one; nevertheless those difficulties have been surmounted, and
calculation has confirmed the suppositions of them, each observation is
become a new demonstration, and the systematic order of the universe is
laid open to the eyes of all those who can distinguish truth from error.
We feel some little stop, by the force of impulsion remaining unknown;
but this, however, does not by any means affect the general theory. We
evidently see the force of attraction always draws the planets towards
the sun, they would fall in a perpendicular line, on that planet, if
they were not repelled by some other power that obliges them to move in
a straight line, and which impulsive force would compel them to fly off
the tangents of their respective orbits, if the force of attraction
ceased one moment. The force of impulsion was certainly communicated to
the planets by the hand of the Almighty, when he gave motion to the
universe; but we ought as much as possible to abstain in physics from
having recourse to supernatural causes; and it appears that a probable
reason may be given for this impulsive force, perfectly accordant with
the law of mechanics, and not by any means more astonishing than the
changes and revolutions which may and must happen in the universe.
The sphere of the sun's attraction does not confine itself to the orbs
of the planets, but extends to a remote distance, always decreasing in
the same ratio as the square of the distance increases; it is
demonstrated that the comets which are lost to our sight, in the regions
of the sky, obey this power, and by it their motions, like that of the
planets, are regulated. All these stars, whose tracts are so different,
move round the sun, and describe areas proportioned to the time; the
planets in ellipses more or less approaching a circle, and the comets in
narrow ellipses of a great extent. Comets and planets move, therefore,
by virtue of the force of attraction and impulsion, which continually
acting at one time obliges them to describe these courses; but it must
be remarked that comets pass over the solar system in all directions,
and that the inclinations of their orbits are very different, insomuch
that, although subject like the planets to the force of attraction, they
have nothing in common with respect to their progressive or impulsive
motions, but appear in this respect independent of each other: the
planets, on the contrary, move round the sun in the same direction, and
almost in the same plane, never exceeding 7-1/2 degrees of inclination
in their planes, the most distant from their orbits. This conformity of
position and direction in the motion of the planets, necessarily implies
that their impulsive force has been communicated to them by one and the
same cause.
May it not be imagined, with some degree of probability, that a comet
falling into the body of the sun, will displace and separate some parts
from the surface, and communicate to them a motion of impulsion,
insomuch that the planets may formerly have belonged to the body of the
sun, and been detached therefrom by an impulsive force, and which they
still preserve.
This supposition appears to be at least as well founded as the opinion
of Leibnitz, who supposes that the earth and planets had formerly been
suns; and his system, of which an account will be given in the fifth
article, would have been more comprehensive and more agreeable to
probability, if he had raised himself to this idea. We agree with him in
thinking that this effect was produced at the time when Moses said that
God divided light from darkness; for, according to Leibnitz, light was
divided from darkness when the planets were extinguished; but in our
supposition there was a real physical separation, since the opaque
bodies of the planets were divided from the luminous matter which
composes the sun.
This idea of the cause of the impulsive force of the planets will be
found much less objectionable, when an estimation is made of the
analogies and degrees of probability, by which it may be supported. In
the first place, the motion of the planets are in the same direction,
from West to East, and therefore, according to calculation, it is
sixty-four to one that such would not have been the case, if they had
not been indebted to the same cause for their impulsive forces.
This, probably, will be considerably augmented by the second analogy,
viz. that the inclination of the planes of the orbits do not exceed
7-1/2 degrees; for, by comparing the spaces, we shall find there is
twenty-four to one, that two planets are found in their most distant
places at the same time, and consequently ⁵, or 7,692,624 to one,
that all six would by chance be thus placed; or, what amounts to the
same, there is a great degree of probability that the planets have been
impressed with one common moving force, and which has given them this
position. But what can have bestowed this common impulsive motion, but
the force and direction of the bodies by which it was originally
communicated? It may therefore be concluded, with great probability,
that the planets received their impulsive motion by one single stroke.
This likelihood, which is almost equivalent to a certainty, being
established, I seek to know what moving bodies could produce this
effect, and I find nothing but comets capable of communicating a motion
to such vast bodies.
By examining the course of comets, we shall be easily persuaded, that it
is almost necessary for some of them occasionally to fall into the sun.
That of 1680 approached so near, that at its perihelium it was not more
distant from the sun than a sixteenth part of its diameter, and if it
returns, as there is every appearance it will, in 2255, it may then
possibly fall into the sun; that must depend on the rencounters it will
meet with in its road, and of the retardment it suffers in passing
through the atmosphere of the sun[78:A].
We may, therefore, presume with the great Newton, that comets sometimes
fall into the sun; but this fall may be made in different directions. If
they fall perpendicular, or in a direction not very oblique, they will
remain in the sun, and serve for food to the fire which that luminary
consumes, and the motion of impulsion which they will have communicated
to the sun, will produce no other effect than that of removing it more
or less, according as the mass of the comet will be more or less
considerable; but if the fall of the comet is in a very oblique
direction, which will most frequently happen, then the comet will only
graze the surface of the sun, or slightly furrow it; and in this case it
may drive out some parts of matter to which it will communicate a common
motion of impulsion, and these parts so forced out of the body of the
sun, and even the comet itself, may then become planets, and turn round
this luminary in the same direction, and in almost the same plane. We
might perhaps calculate what quantity of matter, velocity, and direction
a comet should have, to impel from the sun an equal quantity of matter
to that which the six planets and their satellites contain; but it will
be sufficient to observe here, that all the planets, with their
satellites, do not make the 650th part of the mass of the sun,[79:A]
because the density of the large planets, Saturn and Jupiter, is less
than that of the sun; and although the earth be four times, and the moon
near five times more dense than the sun, they are nevertheless but as
atoms in comparison with his extensive body.
However inconsiderable the 650th part may be, yet it certainly at first
appears to require a very powerful comet to separate even that much
from the body of the sun; but if we reflect on the prodigious velocity
of comets in their perihelion, a velocity so much the greater as they
approach nearer the sun; if, besides, we pay attention to the density
and solidity of the matter of which they must be composed, to suffer,
without being destroyed, the inconceivable heat they endure; and
consider the bright and solid light which shines through their dark and
immense atmospheres, which surround, and must obscure them, it cannot be
doubted that the comets are composed of extremely solid and dense
matters, and that they contain a greater quantity of matter in a small
compass; that consequently a comet of no extraordinary bulk may have
sufficient weight and velocity to displace the sun, and give a
projectile motion to a quantity of matter, equal to the 650th part of
the mass of this luminary. This perfectly agrees with what is known
concerning the density of planets, which always decreases as their
distance from the sun is increased, they having less heat to support; so
that Saturn is less dense than Jupiter, and Jupiter much less than the
earth; therefore if the density of the planets be, as Newton asserts,
proportionable to the quantity of heat which they have to support,
Mercury will be seven times more dense than the earth, and twenty-eight
times denser than the sun; and the comet of 1680 would be 28,000 times
denser than the earth, or 112,000 times denser than the sun, and by
supposing it as large as the earth, it would contain nearly an equal
quantity of matter to the ninth part of the sun, or by giving it only
the 100th part of the size of the earth, its mass would still be equal
to the 900th part of the sun. From whence it is easy to conclude, that
such a body, though it would be but a small comet, might separate and
drive off from the sun a 900th or a 650th part, particularly if we
attend to the immense velocity with which comets move when they pass in
the vicinity of the sun.
Besides this, the conformity between the density of the matter of the
planets, that of the sun deserves some attention. It is well known,
that, both on and near the surface of the earth, there are some matters
14 or 1500 times denser than others. The densities of gold and air are
nearly in this relation. But the internal parts of the earth and planets
are composed of a more uniform matter, whose comparative density varies
much less; and the conformity in the density of the planets and that of
the sun is such, that of 650 parts which compose the whole of the matter
of the planets, there are more than 640 of the same density as the
matter of the sun, and only ten parts out of these 650 which are of a
greater density, for Saturn and Jupiter are nearly of the same density
as the sun, and the quantity of matter which these planets contain, is
at least 64 times greater than that of the four inferior planets, Mars,
the Earth, Venus, and Mercury. We must therefore admit, that the matter
of which the planets are generally composed is nearly the same as that
of the sun, and that consequently the one may have been separated from
the other.
But it may be said, if the comet, by falling obliquely on the sun, drove
off the matter which compose the planets, they, instead of describing
circles of which the sun is the centre, would, on the contrary, at each
revolution, have returned to the same point from whence they departed,
as every projectile would which might be thrown off with sufficient
force from the surface of the earth, to oblige it to turn perpetually:
for it is easy to demonstrate that such, in that instance, would be the
case, and therefore that the projection of the planets from the sun
cannot be attributed to the impulsion of a comet.
To this I reply, that the matter which composes the planets did not come
from the sun, in ready formed globes, but in the form of torrents, the
motion of the anterior parts of which were accelerated by that of the
posterior; and that the attraction of the anterior parts also
accelerated the motion of the posterior, and that this acceleration
produced by one or other of these causes, or perhaps by both, might be
so great as to change the original direction of the motion occasioned by
the impulse of the comet, from which cause a motion has resulted, such
as we at present observe in the planets; especially when it is
considered the sun is displaced from its station by the shock of the
comet. An example will render this more reasonable; let us suppose, that
from the top of a mountain a musket ball is discharged, and that the
strength of the powder was sufficient to send it beyond the
semi-diameter of the earth, it is certain that this ball would pass
round the earth, and at each revolution return to the spot from whence
it had been discharged: but, if instead of a musket-ball, we suppose a
rocket had been discharged, wherein the action of the fire being
durable, would greatly accelerate the motion of impulsion; this rocket,
or rather the cartouch which contained it, would not return to the same
place like the musket-ball, but would describe an orbit, whose perigee
would be much farther distant from the earth, as the force of
acceleration would be greater, and have changed the first direction.
Thus, provided there had been any acceleration in the motion of
impulsion communicated to the torrent of matter by the fall of the
comet, it is probable that the planets formed in this torrent, acquired
the motion which we know they have in the circles and ellipsis of which
the sun is the centre and focus.
The manner in which the great eruptions of volcanos are made, may afford
us an idea of this acceleration of motion. It has been remarked that
when Vesuvius begins to roar and eject the inflamed matter it contains,
the first cloud has but a small degree of velocity, but which is soon
accelerated by the impulse of the second; the second by the action of a
third, and so on, until the heavy mass of bitumen, sulphur, cinders,
melted metal, and huge stones, appear like massive clouds, and although
they succeed each other nearly in the same directions, yet they greatly
change that of the first, and drive it far beyond what it would have
reached of itself.
In answer to this objection, it may be further observed, that the sun
having been struck by the comet, received a degree of motion by the
impulse, which displaced it from its former situation; and that although
this motion of the sun is at present too little sensible for the notice
of astronomers, nevertheless it may still exist, and the sun describe a
curve round the centre of gravity of the whole system and if this is so,
as I presume it is, we see perfectly that the planets, instead of
returning near the sun at each revolution, will, on the contrary, have
described orbits, the points of the perihelion of which will be as far
distant from the sun, as it is itself from the place it originally
occupied.
It may also be said, that if this acceleration of motion is made in the
same direction, no change in the perihelion will be produced: but can it
be thought that in a torrent, the particles of which succeed each other,
there has been no change of direction; it is, on the contrary, very
probable that a considerable change did take place, sufficient to cause
the planets to move in the course they at present occupy.
It may be further urged, that if the sun had been displaced by the shock
of a comet, it would move uniformly, and that hence this motion being
common to the whole system, no alteration was necessary; but might not
the sun before the shock have had a motion round the centre of the
cometry system, to which primitive motion the stroke of the comet may
have added or diminished? and would not that fully account for the
actual motion of the planets?
If these suppositions are not admitted, may it not be presumed, that in
the stroke of the comet against the sun, there was an elastic force
which raised the torrent above the surface of the sun, instead of
directly impelling it? which alone would be sufficient to remove the
perihelion, and give the planets the motion they have retained. This
supposition is not without probability, for the matter of the sun may
possibly be very elastic, since light, the only part of it we are
acquainted with, seems, by its effects, to be perfectly so. I own that
I cannot say whether it is by the one or the other of these reasons,
that the direction of the first motion of the impulse of the planets has
changed, but they suffice to shew that such an alteration is not only
possible but even probable, and that is sufficient for my purpose.
But, without dwelling any longer on the objections which might be made,
I shall pursue the subject, and draw the fair conclusions on the proofs
which analogies might furnish in favour of my hypothesis: let us,
therefore, first see what might happen when these planets, and
particularly the earth, received their impulsive motion, and in what
state they were after having been separated from the sun. The comet
having, by a single stroke, communicated a projectile motion to a
quantity of matter equal to the 650th part of the sun's mass, the light
particles would of course separate from the dense, and form, by their
mutual attraction, globes of different densities: Saturn being composed
of the most gross and light parts, would be the most remote from the
sun: Jupiter being more dense than Saturn, would be less distant, and so
on. The larger and least solid planets are the most remote, because
they received an impulsive motion stronger than the smallest, and more
dense: for, the force of impulsion communicating itself according to the
surface, the same stroke would have moved the grosser and lighter parts
of the matter of the sun with more velocity than the smallest and more
weighty; a separation therefore will be made of the dense parts of
different degrees, so that the density of the sun being equal to 100,
that of Saturn will be equal to 67, that of Jupiter to 94-1/2, that of
Mars to 200, that of the Earth to 400, that of Venus to 800, and that of
Mercury to 2800. But the force of attraction not communicating like that
of impulsion, according to the surface, but acting on the contrary on
all parts of the mass, it will have checked the densest portions of
matter; and it is for this reason that the densest planets are the
nighest the sun, and turn round that planet with greater rapidity than
the less dense planets, which are also the most remote.
Jupiter and Saturn, which are the largest and principal planets of the
solar system, have retained the relation between their density and
impulsive motions, in the most exact proportions; the density of Saturn
is to that of Jupiter as 67 to 94-1/2 and their velocities are nearly
as 88-2/3 to 120-1/72, or as 67 to 90-11/16; it is seldom that pure
conjectures can draw such exact relations. It is true, that by following
this relation between the velocity and density of planets, the density
of the earth ought to be only as 206-7/18, and not 400, which is its
real density; from hence it may be conceived, that our globe was
formerly less dense than it is at present. With respect to the other
planets, Mars, Venus, and Mercury, as their densities are known only by
conjecture, we cannot be certain whether this circumstance will destroy
or confirm our hypothesis. The opinion of Newton is, that density is so
much the greater, as the heat to which the planet is exposed is the
stronger; and it is on this idea that we have just said that Mars is one
time less dense than the Earth, Venus one time, Mercury seven times, and
the comet in 1680, 28,000 times denser than the earth: but this
proportion between the density of the planets and the heat which they
sustain, seems not well founded, when we consider Saturn and Jupiter,
which are the principal objects; for, according to this relation between
the density and heat, the density of Saturn would be about 4-7/18, and
that of Jupiter as 14-17/22, instead of 67 and 94-1/2, a difference too
great to be admitted, and must destroy the principles upon which it was
founded. Thus, notwithstanding the confidence which the conjectures of
Newton merit, I can but think that the density of the planets has more
relation with their velocity than with the degree of heat to which they
are exposed. This is only a final cause, and the other a physical
relation, the preciseness of which is remarkable in Jupiter and Saturn:
it is nevertheless true, that the density of the earth, instead of being
206-7/8, is found to be 400, and that consequently the terrestrial globe
must be condensed in this ratio of 206-7/8 to 400.
But have not the condensations of the planets some relation with the
quantity of the heat of the sun which they sustain? If so, Saturn, which
is the most distant from that luminary, will have suffered little or no
condensation; and Jupiter will be condensed from 90-11/16 to 94-1/2. Now
the heat of the sun in Jupiter being to that of the sun upon the earth
as 14-17/22 are to 400, the condensations ought to be in the same
proportion. For instance, if Jupiter be condensed, as 90-11/16 to
94-1/2, and the earth had been placed in his orbit, it would have been
condensed from 206-7/8 to 215-990/1451, but the earth being nearer the
sun, and receiving a heat, whose relation to that which Jupiter receives
is from 400 to 14-17/22, the quantity of condensation it would have
experienced on the orbit of Jupiter by the proportion of 400 to
14-17/22, which gives nearly 234-1/3 for the quantity which the earth
would be condensed. Its density was 206-7/8, by adding the quantity of
its acquired condensation, we find 400-7/8 for its actual density, which
nearly approaches the real density 400, determined to be so by the
parallax of the moon. As to other planets, I do not here pretend to give
exact proportions, but only approximations, to point out that their
densities have a strong relation to their velocity in their respective
orbits.
The comet, therefore, by its oblique fall upon the surface of the sun,
having driven therefrom a quantity of matter equal to the 650th part of
its whole mass; this matter, which must be considered in a liquid state,
will at first have formed a torrent, the grosser and less dense parts of
which will have been driven the farthest, and the smaller and more
dense, having received only the like impulsion, will remain nearest its
source; the force of the sun's attraction would inevitably act upon all
the parts detached from him, and constrain them to circulate around his
body, and at the same time the mutual attraction of the particles of
matter would form themselves into globes at different distances from the
sun, the nearest of which necessarily moving with greater rapidity in
their orbits than those at a distance.
But another objection may be started, and it may be said, if the matter
which composes the planets had been separated from the sun, they, like
him, would have been burning and luminous bodies, not cold and opaque,
for nothing resembles a globe of fire less than a globe of earth and
water; and by comparison, the matter of the earth and planets is
perfectly different from that of the sun?
To this it may be answered, that in the separation the matter changed
its form, and the light or fire was extinguished by the stroke which
caused this motion of impulsion. Besides, may it not be supposed that if
the sun, or a burning star, moved with such velocity as the planet, that
the fire would soon be extinguished; and that is the reason why all
luminous stars are fixed, and that those stars which are called new, and
which have probably changed places, are frequently extinguished and
lost? This remark is somewhat confirmed by what has been observed in
comets; they must burn to the centre when they pass to their perihelium:
nevertheless they do not become luminous themselves, they only exhale
burning vapours, of which they leave a considerable part behind them in
their course.
I own, that in a medium where there is very little or no resistance,
fire may subsist and suffer a very great motion without being
extinguished: I also own, that what I have just said extends only to the
stars which totally disappear, and not to those which have periodical
returns, and appear and disappear alternately without changing place in
the heavens. The phenomena of these stars has been explained in a very
satisfactory manner by M. de Maupertuis, in his discourse on the figures
of the planets. But the stars which appear and afterwards disappear
entirely, must certainly have been extinguished, either by the velocity
of their motion, or some other cause. We have not a single example of
one luminous star revolving round another; and among the number of
planets which compose our system, and which move round the sun with
more or less rapidity, there is not one luminous of itself.
It may also be added, that fire cannot subsist so long in the small as
in large masses, and that the planets must have burnt for some time
after they were separated from the sun, but were at length extinguished
for want of combustible matter, as probably would be the sun itself, and
for the same reason; but in a length of time as far beyond that which
extinguished the planets, as it exceeds in quantity of matter. Be this
as it may, the matter of which the planets are formed being separated
from the sun, by the stroke of a comet, that appears a sufficient reason
for the extinction of their fires.
The earth and planets at the time of their quitting the sun, were in a
state of total liquid fire; in this state they remained only as long as
the violence of the heat which had produced it; and which heat
necessarily underwent a gradual decay: it was in this state of fluidity
that they took their circular forms, and that their regular motions
raised the parts of their equators, and lowered their poles. This
figure, which agrees so perfectly with the laws of hydrostatics, I am of
opinion with Leibnitz, necessarily supposes that the earth and planets
have been in a state of fluidity, caused by fire, and that the internal
part of the earth must be a vitrifiable matter, of which sand, granite,
&c. are the fragments and scoria.
It may, therefore, with some probability, be thought that the planets
appertained to the sun, that they were separated by a single stroke,
which gave to them a motion of impulsion, and that their position at
different distances from the sun proceeds only from their different
densities. It now only remains, to complete this theory, to explain the
diurnal motion of the planets, and the formation or the satellites; but
this, far from adding difficulties to my hypothesis, seems, on the
contrary, to confirm it.
For the diurnal motion, or rotation, depends solely on the obliquity of
the stroke, an oblique impulse therefore on the surface of a body will
necessarily give it a rotative motion; this motion will be equal and
always the same, if the body which receives it is homogeneous, and it
will be unequal if the body is composed of heterogeneous parts, or of
different densities; hence we may conclude that in all the planets the
matter is homogeneous, since their diurnal motions are equal, and
regularly performed in the same period of time. Another proof that the
separation of the dense or less dense parts were originally from the
sun.
But the obliquity of the stroke might be such, as to separate from the
body of the principal planet a small part of matter, which would of
course continue to move in the same direction; these parts would be
united, according to their densities, at different distances from the
planet, by the force of their mutual attraction, and at the same time
follow its course round the sun, by revolving about the body of the
planet, nearly in the plane of its orbit. It is plain, that those small
parts so separated are the satellites: thus the formation, position, and
direction of the motions of the satellites perfectly agree with our
theory; for they have all the same motion in concentrical circles round
their principal planet; their motion is in the same direction, and that
nearly in the plane of their orbits. All these effects, which are common
to them, and which depend on an impulsive force, can proceed only from
one common cause, which is, impulsive motion, communicated to them by
one and the same oblique stroke.
What we have just said on the cause of the motion and formation of the
satellites, will acquire more probability, if we consider all the
circumstances of the phenomena. The planets which turn the swiftest on
their axis, are those which have satellites. The earth turns quicker
than Mars in the relation of about 24 to 15; the earth has a satellite,
but Mars has none. Jupiter, whose rapidity round its axis is five to six
hundred times greater than that of the earth, has four satellites, and
there is a great appearance that Saturn, which has five, and a ring,
turns still more quickly than Jupiter.
It may even be conjectured with some foundation, that the ring of Saturn
is parallel to the equator of the planet, so that the plane of the
equator of the ring, and that of Saturn, are nearly the same; for by
supposing, according to the preceding theory, that the obliquity of the
stroke by which Saturn has been set in motion was very great, the
velocity around the axis will, at first, have been in proportion as the
centrifugal force exceeds that of gravity, and there will be detached
from its equator and neighbouring parts, a considerable quantity of
matter, which will necessarily have taken the figure of a ring, whose
plane must be nearly the same as that of the equator of the planet; and
this quantity of matter having been detached from the vicinity of the
equator of Saturn, must have lowered the equator of that planet, which
causes that, notwithstanding its rapidity, the diameters of Saturn
cannot be so unequal as those of Jupiter, which differ from each other
more than an eleventh part.
However great the probability of what I have advanced on the formation
of the planets and their satellites may appear to me, yet, every man has
his particular measurement, to estimate probabilities of this nature;
and as this measurement depends on the strength of the understanding to
combine more or less distant relations, I do not pretend to convince the
incredulous. I have not only thought it my duty to offer these ideas,
because they appear to me reasonable, and calculated to clear up a
subject, on which, however important, nothing has hitherto been written,
but because the impulsive motion in the planets enter at least as one
half of the composition of the universe, which gravity alone cannot
unfold. I shall only add the following questions to those who are
inclined to deny the possibility of my system.
1. Is it not natural to imagine, that a body in motion has received that
motion by the stroke of another body?
2. Is it not very probable, that when many bodies move in the same
direction, that they have received this direction by one single stroke,
or by many strokes directed in the same manner?
3. Is it not more probable that when many bodies have the same direction
in their motion, and are placed in the same plane, that they received
this direction and this position by one and the same stroke, rather than
by a number?
4. At the time a body is put in motion by the force of impulsion, is it
not probable that it receives it obliquely, and, consequently, is
obliged to turn on its axis so much the quicker, as the obliquity of the
stroke will have been greater? If these questions should not appear
unreasonable, the theory, of which we have presented the outlines, will
cease to appear an absurdity.
Let us now pass on to something which more nearly concerns us, and
examine the figure of the earth, on which so many researches and such
great observations have been made. The earth being, as it appears by the
equality of its diurnal motion and the constancy of the inclination of
its axis, composed of homogeneous parts, which attract each other in
proportion to their quantity of matter, it would necessarily have taken
the figure of a globe perfectly spherical, if the motion of impulsation
had been given it in a perpendicular direction to the surface; but this
stroke having been obliquely given, the earth turned on its axis at the
moment it took its form; and from the combination of this impulsive
force, the attraction of the parts, there has resulted a spheroid
figure, more elevated under the great circle of rotation, and lower at
the two extremities of the axis, and this because the action of the
centrifugal force proceeding from the diurnal rotation must diminish the
action of gravity. Thus, the earth being homogeneous, and having
received a rotative motion, necessarily took a spheroidical figure, the
two axes of which differ a 230th part from each other. This may be
clearly demonstrated, and does not depend on any hypothesis whatever.
The laws of gravity are perfectly known, and we cannot doubt that
bodies attract each other in a direct ratio of their masses, and in an
inverted ratio, at the squares of their distances; so likewise we cannot
doubt, that the general action of any body is not composed of all the
particular actions of its parts. Thus each part of matter mutually
attracts in a direct ratio of its mass and an inverted ratio of its
distance, and from all these attractions there results a sphere when
there is no rotatory motion, and a spheroid when there is one. This
spheroid is longer or shorter at the two extremities of the axis of
rotation, in proportion to the velocity of its diurnal motion, and the
earth has then, by virtue of its rotative velocity, and of the mutual
attraction of all its parts, the figure of a spheroid, the two axes of
which are as 229 to 230 to one another.
Thus, by its original constituent, by its homogeneousness, and
independent of every hypothesis from the direction of gravity, the earth
has taken this figure of a spheroid at its formation, and agreeable to
mechanical laws: its equatorial diameter was raised about 6-1/2 leagues
higher than under the poles.
I shall dwell on this article, because there are still geometricians who
think that the figure of the earth depends upon theory, and this from a
system of philosophy they have embraced, and from a supposed direction
of gravity. The first thing we have to demonstrate is, the mutual
attraction of every part of matter, and the second the homogeneousness
of the terrestrial globe; if we clearly prove, that these two
circumstances are really so, there will no longer be any hypothesis to
be made on the direction of gravity: the earth will necessarily have the
figure Newton decided in favour of, and every other figure given to it
by virtue of vortexes or other hypotheses, will not be able to subsist.
It cannot be doubted, that it is the force of gravity which retains the
planets in their orbits; the satellites of Saturn gravitate towards
Saturn, those of Jupiter towards Jupiter, the Moon gravitates towards
the Earth: and Saturn, Jupiter, Mars, the Earth, Venus, and Mercury,
gravitate towards the Sun: so likewise Saturn and Jupiter gravitate
towards their satellites, the Earth gravitates towards the Moon, and the
Sun towards the whole of the planets. Gravitation is therefore general
and mutual in all the planetary system, for action cannot be exercised
without a re-action; all the planets, therefore, act mutually one on the
other. This mutual attraction serves as a foundation to the laws of
their motion, and is demonstrated to exist by its effects. When Saturn
and Jupiter are in conjunction, they act one on the other, and this
attraction produces an irregularity in their motion round the Sun. It is
the same with the Earth and the Moon, they also mutually attract each
other; but the irregularities of the motion of the Moon, proceeds from
the attraction of the Sun, so that the Earth, the Sun, and the Moon,
mutually act one on the other. Now this mutual attraction of the
planets, when the distances are equal, is proportional to their quantity
of matter, and the same force of gravity which causes heavy matter to
fall on the surface of the Earth, and which extends to the Moon, is also
proportional to the quantity of matter; therefore the total gravity of a
planet is composed of the gravity of each of its parts; from whence all
the parts of the matter, either in the Earth or in the planets, mutually
attract each other and the Earth, by its rotation round its own axis,
has necessarily taken the figure of a spheroid, the axes of which are as
229 to 230. The direction of the weight must be perpendicular to the
Earth's surface; consequently no hypothesis, drawn from the direction of
gravity, can be sustained, unless the general attraction of the parts of
matter be denied; but the existence of this mutual attraction is
demonstrated by observations, and the experiment of pendulums prove,
that its extension is general; therefore we cannot support an hypothesis
on the direction of gravity without going against experience and reason.
Let us now proceed to examine whether the matter of which the
terrestrial globe is composed be homogeneous. I admit, that if it is
supposed the globe is more dense in some parts than in others, the
direction of gravity must be different from what we have just assigned,
and that the figure of the Earth would also differ agreeable to those
suppositions. But what reason have we to make these suppositions? Why,
for example, should we suppose that the parts near the centre are denser
than those which are more remote? Are not all the particles which
compose the globe collected together by their mutual attraction? hence,
each particle is a centre, and there is no reason to believe, that the
parts which surround the centre are denser than those which are about
any other point. Besides, if one considerable part of the globe was
denser than another, the axis of rotation would be found near the dense
parts, and an inequality would ensue in the diurnal revolution; we
should remark an inequality in the apparent motion of the fixed stars;
they would appear to move more quick or slow in the zenith, or horizon,
according as we should be placed on the denser or lighter parts of the
earth; and the axis of the globe no longer passing through the centre of
gravity, would also very sensibly change its position: but nothing like
this ever happens; on the contrary, the diurnal motion of the earth is
equal and uniform. At all parts of the Earth's surface, the stars appear
to move with the same velocity at all heights, and if there be any
rotation in its axis, it is so trifling as to have escaped observation:
it must therefore be concluded, that the globe is homogeneous, or nearly
so in all its parts.
If the earth was a hollow and void globe, and the crust of which, for
example, not more than two or three miles thick; it would produce these
effects. 1. The mountains would be such considerable parts of the whole
thickness of the crust, that great irregularities in the motions of the
Earth would be occasioned by the attraction of the Moon and Sun: for
when the highest parts of the globe, as the Cordeliers, should have the
Moon at noon, the attraction would be much stronger on the whole globe
than when she was in the meridian of the lowest parts. 2. The attraction
of mountains would be much more considerable than it is in comparison
with the attraction of the whole globe, and experiments made at the
mountain of Chimboraco, in Peru, would in this case give more degrees
than they have given seconds for the deviation of the plumb line. 3. The
weight of bodies would be greater on the tops of high mountains than on
the planes; so that we should feel ourselves considerably heavier, and
should walk with more difficulty in high than in low places. These
observations, with many others that might be added, must convince us,
that the inner parts of the globe is not void, but filled with a dense
matter.
On the other hand, if below the depth of two or three miles, the earth
was filled with a matter much more dense than any known, it would
necessarily occur, that every time we descended to moderate depths, we
should weigh much more, and the motion of pendulums would be more
accelerated than in fact they are when carried from an eminence into a
plain: thus, we may presume that the internal part of the Earth is
filled with a matter nearly similar to that which composes its surface.
What may complete our determination in favour of this opinion is, that
in the first formation of the globe, when it took its present
spheroidical figure, the matter which composed it was in fusion, and,
consequently, all its parts were homogeneous, and nearly equally dense.
From that time the matter on the surface, although originally the same
with the interior, has undergone a variety of changes by external
causes, which has produced materials of such different densities; but it
must be remarked, that the densest matters, as gold and metals, are also
those the most seldom to be met with, and consequently the greatest part
of the matter at the surface of the globe has not undergone any very
great changes with relation to its density; the most common materials,
as sand and clay, differ very little, insomuch, that we may conjecture,
with great probability, that the internal part of the earth is composed
of a vitrified matter, the density of which is nearly the same as that
of sand, and that consequently the terrestrial globe in general may be
regarded as homogeneous.
Notwithstanding this, it may be urged, that although the globe was
composed of concentrical strata of different densities, the diurnal
motion might be equally certain, and the uniform inclination of the axis
as constant and undisturbed as it could be, on the supposition of its
being composed of homogeneous matter. I acknowledge it, but I ask at the
same time, if there is any reason to believe that strata of different
densities do exist? If these conclusions be not rather a desire to
adjust the works of Nature to our own ideas? And whether in physics we
ought to admit suppositions which are not founded on observations or
analogy?
It appears, therefore, that the earth, by virtue of the mutual
attraction of its parts and its diurnal motion, assumed the figure of a
spheroid; that it necessarily took that form from being in a state of
fluidity; that, agreeable to the laws of gravity and of a centrifugal
force, it could have no other figure: that in the moment of its
formation as at present, there was a difference between the two
diameters equal to a 230th part, and that, consequently, every
hypothesis in which we find greater or less difference are fictions
which merit no attention.
But it may be said, if this theory is true, and if 229 to 230 is the
just relation of the axis, why did the mathematicians, sent to Lapland
and Peru, agree to the relation of 174 to 175? From whence does this
difference arise between theory and practice? And is it not more
reasonable to give the preference to practice and measures, especially
when we have been taken by the most able mathematicians of
Europe[109:A], and with all necessary apparatus to establish the result.
To this I answer, that I have paid attention to the observations made at
the equator and near the polar circle; that I have no doubt of their
being exact, and that the earth may possibly be elevated an 175th part
more at the equator than at the poles. But, at the same time, I maintain
my theory, and I see clearly how the two conclusions may be reconciled.
This difference is about four leagues in the two axes, so that the parts
at the equator are raised two leagues more than they ought to be,
according to my theory; this height answers exactly to the greatest
inequalities on the surface of the globe, produced by the motion of the
sea, and the action of the fluids. I will explain; it appears that when
the earth was formed, it must necessarily have taken, by virtue of the
mutual attraction of its parts, and the action of the centrifugal force,
a spheroidical figure, the axes of which differ a 230th part: the
original earth must have had this figure, which it took when it was
fluid, or rather liquified by the fire; but after its formation the
vapours which were extended and rarefied, as in the atmosphere and tail
of a comet, became condensed, and fell on the surface in form of air and
water: and when these waters became agitated by the flux and reflux, the
matters were, by degrees, carried from the poles towards the equatorial
parts; so that the poles were lowered about a league, and those of the
equator raised in the same proportion; this was not suddenly done, but
by degrees in succession of time; the earth being also exposed to the
action of the winds, air, and sun; all these irregular causes concurred
with the flux and reflux to furrow its surface, hollow it into valleys,
and raise it into mountains; and producing other inequalities and
irregularities, of which, nevertheless, the greatest thickness does not
exceed one league at the equator; this inequality of two leagues, is,
perhaps, the greatest which can be on the surface of the earth, for the
highest mountains are scarce above one league in height, and there is
much probability of the sea's not being more at its greatest depth. The
theory is therefore true, and practice may be so likewise; the earth at
first could not be raised above 6-1/2 leagues more at the equator than
the poles, but the changes which have happened to its surface might
afterwards raise it still more. Natural History wonderfully confirms
this opinion, for we have proved in the preceding discourse that the
flux and reflux, and other motions of the water, have produced mountains
and all the inequalities on the surface of the globe, that this surface
has undergone considerable changes, and that at the greatest depths, as
well as on the greatest heights, bones, shells and other wrecks of
animals, which inhabit the sea and earth, are met with.
It may be conjectured, from what has been said, that to find ancient
earth, and matters which have never been removed from the spot in which
they were first placed, we must dig near the poles, where the bed of the
earth must be thinner than in the Southern climates.
On the whole, if we strictly examine the measures by which the figure of
the earth is determined, we shall perceive this hypothesis enters into
such determination; for it supposes the earth to have the figure of a
regular curve, whereas from the constant changes the earth is
continually undergoing from a variety and combination of causes, it is
almost impossible that it should have retained any regular figure, and
hence the poles might, originally, only be flattened a 230th part, as
Newton says, and as my theory requires. Besides, although we had exactly
the length of the degree at the polar circle and equator, have we not
also the length of the degree as exactly in France? And the measure of
M. Picard, has it not been verified? Add to this that the augmentation
and diminution in the motion of the pendulum, do not agree with the
result drawn from measurement, and that, on the contrary, they differ
very little from the theory of Newton. This is surely more than is
requisite to convince us that the poles are not flattened more than a
230th part, and that if there is any difference, it can proceed only
from the inequalities, which the water and other external causes have
produced on its surface; but these inequalities being more irregular
than regular, we must not form any hypothesis thereon, nor suppose, that
the meridians are ellipses, or any other regular curves. From whence we
perceive, that if we should successively measure many degrees of the
earth in all directions, we still should not be certain by that alone,
of the exact situation of the poles, nor whether they were depressed
more or less than the 230th part.
May it not also be conjectured, that if the inclination of the axis of
the earth has changed, it can only be produced by the changes which have
happened to the surface, since all the rest of the globe is homogeneous;
that consequently this variation is too little sensible to be perceived
by astronomers, and that if the earth is not encountered with a comet,
or deranged, by any other external cause, its axis will remain
perpetually inclined as it is at present, and as it has always been?
In order not to omit any conjecture which appears reasonable, may it not
be said, that as the mountains and inequalities which are on the
surface of the earth have been formed by the flux and reflux of the sea,
the mountains and inequalities which we remark on the surface of the
moon, have been produced by a similar cause? they certainly are much
higher than those of the earth, but then her tides are also much
stronger, occasioned by the earth's being considerably larger than the
moon, and consequently producing her tides with a superior force; and
this effect would be much greater if the moon had, like the earth, a
rapid rotation; but as the moon presents always the same surface to the
earth, the tides cannot operate but in proportion to the motion arising
from her libration, by which it alternatively discovers to us a segment
of its other hemisphere; this, however, must produce a kind of flux and
reflux, quite different from that of our sea, and the effects of which
will be much less considerable than if the moon had from its course a
revolution round its axis, as quick as the rotation of the terrestrial
globe.
I should furnish a volume as large as that of Burnet or Whiston's, if I
were to enlarge on the ideas which arise in support of the above; by
giving them a geometrical air, in imitation of the last author, I might
add considerably to their weight; but, in my opinion, hypothesis,
however probable, ought not to be treated with such pomposity; it being
a dress which borders so much on quackery.
FOOTNOTES:
[78:A] Vide Newton, 2d edit. page 525.
[79:A] Vid. Newton, page 405.
[109:A] M. de Maupertuis' Figure of the Earth.
ARTICLE II.
FROM THE SYSTEM OF WHISTON[115:A].
This Author commences his treatise by a dissertation on the creation of
the world; he says that the account of it given by Moses in the text of
Genesis has not been rightly understood; that the translators have
confined themselves too much to the letter and superficial views,
without attending to nature, reason, and philosophy. The common notion
of the world being made in six days, he says is absolutely false, and
that the description given by Moses, is not an exact and philosophical
narration of the creation and origin of the universe, but only an
historical representation of the terrestrial globe. The earth,
according to him, existed in the chaos; and, at the time mentioned by
Moses, received the form, situation and consistency necessary to be
inhabited by the human race. I shall not enter into a detail of his
proofs, nor undertake their refutation. The exposition we have just
made, is sufficient to demonstrate the difference of his opinion with
public facts, its contrariety with scripture, and consequently the
insufficiency of his proofs. On the whole, he treats this matter as a
theological controvertist, rather than as an enlightened philosopher.
Leaving these erroneous principles, he flies to ingenious suppositions,
which, although extraordinary, yet have a degree of probability to those
who, like him, incline to the enthusiasm of system. He says, that the
ancient chaos, the origin of our earth, was the atmosphere of a comet:
that the annual motion of the earth began at the time it took its new
form, but that its diurnal motion began only when the first man fell.
That the ecliptic cut the tropic of cancer, opposite to the terrestrial
paradise, which was situated on the north-west side of the frontiers of
Assyria: that before the deluge, the year began at the autumnal
equinox: that the orbits of the planets, and the earth were then
perfect circles. That the deluge began the 18th of November, 2365 of the
Julian period, or 2349 years before Christ. That the solar and lunar
year were then the same, and that they exactly contained 360 days. That
a comet descending in the plane of the ecliptic towards its perihelion,
passed near the globe of the earth the same day as the deluge began:
that there is a great heat in the internal part of the terrestrial
globe, which constantly diffuses itself from the centre to the
circumference; that the form of the earth is like that of an egg, the
ancient emblem of the globe; that mountains are the lightest part of the
earth, &c. He afterwards attributes all the alterations and changes
which have happened to the earth, to the universal deluge; then blindly
adopts the theory of Woodward, and indiscriminately makes use of all the
observations of that author on the present state of the globe; but
assumes originality when he speaks of its future state: according to him
it will be consumed by fire, and its destruction will be preceded by
terrible earthquakes, thunder, and frightful meteors; the Sun and Moon
will have an hideous aspect, the heavens will appear to fall, and the
flames will be general over all the earth; but when the fire shall have
devoured all the impurities it contains; when it shall be vitrified and
rendered transparent as crystal, the saints and the blessed spirits will
return and take possession of it, and there remain till the day of
judgment.
These hypotheses, at the first glance, appear to be rash and extravagant
assertions; nevertheless the author has managed them with such address,
and treated them with such strength, that they cease to appear
absolutely chimerical. He supports his subjects with much science, and
it is surprising that, from a mixture of ideas so very absurd, a system
could be formed with an air of probability. It has not affected vulgar
minds so much as it has dazzled the eyes of the learned, because they
are more easily deceived by the glare of erudition, and the power of
novel ideas. Mr. Whiston was a celebrated astronomer, in the constant
habit of considering the heavens, observing the stars, and contemplating
the wonderful course of nature; he could never persuade himself that
this small grain of sand, this Earth which we inhabit, occupied more the
attention of the Creator than the universe, the vast extent of which
contains millions of other Suns and Earths. He pretends, that Moses has
not given us the history of the first creation of this globe, but only a
detail of the new form that it took when the Almighty turned it from the
mass of a comet into a planet, and formed it into a proper habitation
for men. Comets are, in fact, subjected to terrible vicissitudes by
reason of the eccentricity of their orbits. Sometimes, like that in
1680, it is a thousand times hotter there than red-hot iron; and
sometimes a thousand times colder than ice; if they are, therefore,
inhabited it must be by strange creatures, of which we can have no
conception.
The planets, on the contrary, are places of rest, where the distance of
the sun not varying much, the temperature remains nearly the same, and
permits different kinds of plants and animals to grow and multiply.
In the beginning God created the world; but, observes our author, the
earth was then an uninhabitable comet, suffering alternatively the
excess of heat and cold, its liquifying and freezing by turns formed a
chaos, or an abyss, surrounded with thick darkness: "and darkness
covered the face of the deep," _& tenebræ erant superfaciam abissi_.
This chaos was the atmosphere of the comet, a body composed of
heterogeneous matters, the centre occupied by spherical, solid, and hot
substances, of about two thousand leagues in diameter, round which a
very great surface of a thick fluid extended, mixed with an unshapen and
confused matter, like the chaos of the ancient _rudis & indigestaque
moles_.
This vast atmosphere contained but very few dry, solid, or terrestrial
particles, still less aqueous or aerial, but a great quantity of fluid,
dense and heavy matters, mixed, agitated and jumbled together in the
greatest disorder and confusion. Such was the earth before the six days,
but on the first day of the creation, when the eccentrical orbit of the
comet had been changed, every thing took its place, and bodies arranged
themselves according to the law of gravity, the heavy fluid descended to
the lowest places, and left the upper regions to the terrestrial,
aqueous and aerial parts; those likewise descended according to their
order of gravity; first the earth, then the water, and last of all the
air. The immense volume of chaos was thus reduced to a globe of a
moderate size, in the centre of which is the solid body that still
retains the heat which the sun formerly communicated to it, when it
belonged to a comet. This heat may possibly endure six thousand years,
since the comet of 1680 required fifty thousand years to cool. Around
this solid and burning matter, which occupies the centre of the earth,
the dense and heavy fluid which descended the first is to be found, and
this is the fluid which forms the great abyss on which the earth is
borne, like cork on quicksilver; but as the terrestrial parts were
originally mixed with a large quantity of water, in descending they have
dragged with them a part of this water, which, not being able to
re-ascend after the earth was consolidated, formed a concentrical bed
with the heavy fluid which surrounds this hot substance, insomuch that
the great abyss is composed of two concentrical orbs, the most internal
of which is a heavy fluid, and the other water; the last of which serves
for a foundation to the earth. It is from this admirable arrangement,
produced by the atmosphere of a comet, that the Theory of the Earth, and
the explanation of all its phenomena are to depend.
When the atmosphere of the comet was once disembarrassed from all the
solid and terrestrial matters, there remained only the lighter air,
through which the rays of the sun freely passed and instantly produced
light: "Let there be light, and there was light." The columns which
composed the orb of the Earth being formed with such great precipitation
is the cause of their different densities: consequently the heaviest
sunk deeper into this subterraneous fluid than the lightest; and it is
this which has produced the vallies and mountains on the surface of the
earth. These inequalities were, before the deluge, dispersed and
situated otherwise than they are at present. Instead of the vast valley,
which contains the ocean, there were many small divided cavities on the
surface of the globe, each of which contained a part of this water; the
mountains were also more divided, and did not form chains as at present:
nevertheless, the earth contained a thousand times more people, and was
a thousand times more fertile; and the life of man and other animals
were ten times longer, all which was affected by the internal heat of
the earth that proceeded from the centre, and gave birth to a great
number of plants and animals, bestowing on them a degree of vigour
necessary for them to subsist a long time, and multiply in great
abundance. But this heat, by increasing the strength of bodies,
unfortunately extended to the heads of men and animals; it augmented
their passions; it deprived man of his innocence, and the brute creation
of part of their intelligence; all creatures, excepting fish, who
inhabited a colder element, felt the effects of this heat, became
criminal and merited death. It therefore came, and this universal death
happened on Wednesday the 28th of November, by a terrible deluge of
forty days and forty nights, and was caused by the tail of another comet
which encountered the earth in returning from its perihelion.
The tail of a comet is the lightest part of its atmosphere; it is a
transparent mist, a subtile vapour, which the heat of the sun exhales
from the body of the comet: this vapour composed of extremely rarefied
aqueous and aerial particles, follows the comet when it descends to its
perihelion, and precedes when it re-ascends, so that it is always
situate opposite to the sun, as if it sought to be in the shade, and
avoid the too great heat of that luminary. The column which this vapour
forms is often of an immense length, and the more a comet approaches the
sun, the longer and more extended is its tail, and as many comets
descend below the annual orb of the earth, it is not surprising that
the earth is sometimes found surrounded with the vapour of this tail;
this is precisely what happened at the time of the deluge. In two hours
the tail of a comet will evacuate a quantity of water equal to what is
contained in the whole ocean. In short, this tail was what Moses calls
the cataracts of Heaven, "and the cataracts of Heaven were opened." The
terrestrial globe meeting with the tail of a comet, must, in going its
course through this vapour, appropriate to itself a part of the matter
which it contains; all which, coming within the sphere of the earth's
attraction, must fall on it, and fall in the form of rain, since this
tail is partly composed of aqueous vapours. Thus rain may come down in
such abundance as to produce an universal deluge the waters of which
might easily surmount the tops of the highest mountains. Nevertheless,
our author, cautious of not going directly against the letter of holy
writ, does not say that this rain was the sole cause of the universal
deluge, but takes the water from every place he can find it. The great
abyss as we see contains a considerable quantity. The earth, at the
approach of the comet, would prove the force of its attraction; and the
waters contained in the great abyss would be agitated by so violent a
kind of flux and reflux, that the superficial crust would not resist,
but split in several places, and the internal waters be dispersed over
the surface, "And the fountains of the abyss were opened."
But what became of these waters, which the tail of the comet and great
abyss furnished so liberally? our author is not the least embarrassed
thereon. As soon as the earth, continuing its course, removed from the
comet, the effects of its attraction, the flux and reflux in the great
abyss ceased of course, and immediately the upper waters precipitated
back with violence by the same roads as they had been forced upon the
surface. The great abyss absorbed all the superfluous waters, and was of
a sufficient capacity not only to receive its own waters, but also all
those which the tail of the comet had left, because during its
agitation, and the rupture of its crust, it had enlarged the space by
driving out on all sides the earth that surrounded it. It was at this
time also the figure of the earth, which till then was spherical, became
elliptic. This effect was occasioned by the centrifugal force caused by
its diurnal motion, and by the attraction of the comet, for the earth,
in passing through the tail of the comet, found itself so placed that it
presented the parts of the equator to that planet; and the power of the
attraction of the comet, concurring with the centrifugal force of the
earth, caused the parts of the equator to be elevated, and that with the
more facility as the crust was broken and divided in an infinity of
places, and because the flux and reflux of the abyss drove against the
equator more violently than elsewhere.
Here then is Mr. Whiston's history of the creation; the causes of the
universal deluge; the length of the life of the first men; and the
figure of the Earth; all which seem to have cost our author little or no
labour; but Noah's ark appears to have greatly disquieted him. In the
midst of so terrible a disorder occasioned by the conjunction of the
tail of a comet with the waters of the great abyss, in the terrible
moments wherein not only the elements of the earth were confused, but
when new elements still concurred to augment the chaos, how can it be
imagined that the ark floated quietly with its numerous cargo on the top
of the waves? Here our author makes great efforts to arrive at and give
a physical reason for the preservation of the ark, but which has always
appeared to me insufficient, poorly imagined, and but little
orthodoxical: I will not here relate it, but only observe how hard it is
for a man who has explained objects so great and wonderful, without
having recourse to a supernatural power, to be stopt by one particular
circumstance; our author, however, chose rather to risk drowning with
the ark, than to attribute to the immediate bounty of the Almighty the
preservation of this precious vessel.
I shall only make one remark on this system, of which I have made a
faithful abridgement: which is, whenever we are rash enough to attempt
to explain theological truths by physical reasons, or interpret purely
by human views, the divine text of holy writ, or that we endeavour to
reason on the will of the Most High, and on the execution of his
decrees, we consequently shall involve ourselves in the darkness and
chaos of obscurity and confusion, like the author of this system, which,
in defiance of its absurdities, has been received with great applause.
He neither doubts the truth of the deluge, nor the authenticity of the
sacred writ; but as he was less employed with it than with physic and
astronomy, he has taken passages of the scripture for physical facts,
and the results of astronomical observations; and has so strangely
blended the divine knowledge with human science as to give birth to the
most extraordinary system that possibly ever was or will be conceived.
FOOTNOTES:
[115:A] A New Theory of the Earth by William Whiston, 1708.
ARTICLE III.
FROM THE SYSTEM OF BURNET.[128:A]
This author is the first who has treated this subject generally and in a
systematical matter. He was possessed of much understanding, and was a
person well acquainted with the _belles lettres_. His work acquired
great reputation, and was criticised by many of the learned, among the
rest by Mr. Keil, who has geometrically demonstrated the errors of Mr.
Burnet, in a treatise called "Examination of the Theory of the Earth."
Mr. Keil also refuted Whiston's system; but he treats the last author
very different from the first, and seems even to be of his opinion in
several cases, and looks upon the tail of a comet to be a very probable
cause for the deluge. But, to return to Burnet, his book is elegantly
written; he knew how to paint noble images and magnificent scenes. His
plan is great, but the execution is deficient for want of proper
materials: his reasoning is good, but his proofs are weak; yet his
confidence in his writings is so great, that he frequently causes his
readers to pass over his errors.
He begins by telling us, that before the deluge the earth had a very
different form from that which it has at present; it was at first, he
says, a fluid mass, compounded of matters of all kinds, and all sorts of
figures, the heaviest descended towards the centre, and formed a hard
and solid body; round which the waters collected, and the air, and all
the liquors lighter than water, surmounted them. Between the orb of air
and that of water, was an orb of oily matter, but as the air was still
very impure, and contained a great quantity of small particles of
terrestrial matter, they by degrees descended on the coat of oil, and
formed a terrestrial orb blended with earth and oil; and this was the
first habitable earth, and the first abode of man. This was an excellent
soil, light, and calculated to yield to the tenderness of the first
germs. The surface of the terrestrial globe was at first equal, uniform,
without mountains, without seas, and without inequalities; but it
remained only about sixteen centuries in this state, for the heat of the
sun by degrees drying the crust, split it at first on the surface, soon
after these cracks penetrated farther and increased so considerably by
time, that at length they entirely opened the crust; in an instant the
whole earth fell into pieces in the abyss of water it surrounded; and
this was the cause of the deluge.
But all these masses of earth, by falling into the abyss, dragged along
with them a great quantity of air; these struck against each other,
divided, and accumulated so irregularly, that great cavities filled with
air were left between them. The waters by degrees opened these cavities,
and in proportion as they filled them, the surface of the earth
discovered itself in the highest parts; at length water alone remained
in the lowest parts; that is to say, the vast vallies which contain the
sea. Thus our ocean is a part of the ancient abyss, the rest is entered
into the internal cavities with which the ocean communicates. The
islands and sea rocks are the small fragments, and continents are the
great masses of the old crust. As the rupture and the fall of this crust
are made of a sudden, and with confusion, it was not surprising to find
eminences, depths, plains, and inequalities of all kinds on the surface
of the earth.
FOOTNOTES:
[128:A] Thomas Burnet. Telluris theoria sacra, orbis nostri originem &
mutationes generales, quas aut jam subut, aut olim Subiturus est
complectens. Londina, 1681.
ARTICLE IV.
FROM THE SYSTEM OF WOODWARD.
It may be said of this author, that he attempted to raise an immense
monument on a less solid base than the moving sand, and to construct a
world with dust; for he pretends, that at the time of the deluge a total
dissolution of the earth was made. The first idea which presents, after
having gone through his book,[132:A] is, that this dissolution was made
by the waters of the great abyss. He asserts, that the abyss where the
water was included opened all at once at the command of God, and
dispersed over the surface an enormous quantity of water necessary to
cover the tops of the highest mountains, and that God suspended the
cause of cohesion which reduced all solid bodies into dust, &c. He did
not consider that by these suppositions he added other miracles to that
of the universal deluge, or at least physical impossibilities, which
agree neither with the letter of the holy writ, nor with the
mathematical principles of natural philosophy. But as this author has
the merit of having collected many important observations, and as he was
better acquainted with the materials of which the globe is composed than
those who preceded him, his system, although badly conceived, and worse
digested, has nevertheless dazzled many people, who, seduced by the
truth of some particular circumstances, put confidence in his general
conclusions; we shall, therefore, give a short view of his theory, in
which, by doing justice to the author's merit, and the exactness of his
observations, we shall put the reader in a state of judging of the
insufficiency of his system, and of the falsity of some of his remarks.
Mr. Woodward speaks of having discovered by his sight that all matters
which compose the English earth, from the surface to the deepest places
which had been dug, were disposed by beds of strata, and that in a great
number of these there were shells and other marine productions; he
afterwards adds, that by his correspondents and friends he was assured,
that in other countries the earth is composed of the same materials, and
that shells are found there, not only in the plains but on the highest
mountains, in the deepest quarries, and in an infinity of different
places. He perceived their strata to be horizontal and disposed one over
the other, as matters are which are transported by the waters, and
deposited in form of sediment. These general remarks, which are true,
are followed by particular observations, by which he evidently shews,
that fossils found incorporated in the strata are real shells and marine
productions, not minerals and singular bodies, the sport of nature, &c.
To these observations, though partly made before him, which he has
collected and proved, he adds others less exact. He asserts, that all
matters of different strata are placed one on the other in the order of
their specific gravity.
This general assertion is not true, for we daily see rocks placed above
clay, sand, coal, and bitumen, and which certainly are specifically
heavier than either of these latter materials. If, in fact, we found
throughout the earth that the first strata was bitumen, then chalk, then
marl, clay, sand, stone, marble, and at last metals, so that the
composition of the earth exactly followed the law of gravity, there
would be an appearance that they might have been precipitated at the
same time, which our author asserts with confidence, in spite of the
evidence to the contrary; for, without being a naturalist, we need only
have our eye-sight to be convinced that heavy strata are often found
above lighter, and that consequently these sediments were not
precipitated all at one time, but have been brought and deposited
successively by the water. As this is the foundation of his system, and
is manifestly false, we shall follow it no farther than to show how far
an erroneous principle may produce false combinations and erroneous
conclusions.
All the matters, says our author, which compose the earth, from the
summits of the highest mountains, to the greatest depths of mines, are
disposed by strata, according to their specific weights; therefore he
concludes the whole has been dissolved and precipitated at one time. But
in what manner, and at what time was it dissolved? In water, replies he,
and at the time of the deluge. But there is not a sufficient quantity of
water on the globe for this to be effected, since there is more land
than water, and the bottom of the sea itself is earth. This he admits,
but says, there is more water than is requisite at the centre of the
earth, that it was only necessary for it to ascend, and possess a power
of dissolving every substance but shells, afterwards to find the means
for this water to re-enter the abyss, and to make all this agree with
the history of the deluge. This then is the system, of which the author
does not entertain the least doubt; for when it is opposed to him that
water cannot dissolve marble, stone, and metals, especially in forty
days, the duration of the deluge, he answers simply, that nevertheless
it did happen so. When he is asked, what the virtue of this water of
the abyss was, to dissolve all the earth, and at the same time preserve
the shells? he says, that he never pretended that this water was a
dissolvent; but that it is clear, by facts, that the earth has been
dissolved and the shells preserved. When he was evidently shown that if
he had no reason to give, or facts to support, for these phenomena, his
system was useless, he said, we have only to imagine that, during the
deluge, the force of gravity and the coherency of matter ceased on a
sudden, and by this supposition the dissolution of the old world would
be explained in a very easy and satisfactory manner. But, it was said to
him, if the power which holds the parts of matter united was suspended,
why were not the shells dissolved as well as all the rest? Here he makes
a discourse on the organization of shells and bones of animals, by which
he pretends to prove that their texture being fibrous, and different
from that of minerals, their power of cohesion was different also; after
all, we have, says he, only to suppose that the power of gravity and
cohesion did not entirely cease, but that it was only diminished
sufficient to disunite all the parts of minerals, and not those of
animals. To all this we cannot be prevented from discovering, that our
author's philosophy was not equal to his talents for observation; and I
do not think it necessary seriously to refute opinions which have no
foundation, especially when they have been imagined against the rules of
probability, and drawn from consequences contrary to mechanical laws.
FOOTNOTES:
[132:A] An Essay towards the Natural History of the Earth, &c. by John
Woodward.
ARTICLE V.
EXPOSITION OF SOME OTHER SYSTEMS.
It is plain that the three forementioned hypotheses have much in common
with each other. They all agree in this point, that during the deluge
the earth changed its form, as well externally as internally; but these
speculators have not considered that the earth before the deluge was
inhabited by the same species of men and animals, and must necessarily
have been nearly such as it is at present. The sacred writings teach us,
that before the deluge there were rivers, seas, mountains, and forests.
That these rivers and mountains were, for the most part, retained in the
same situations; the Tigris and Euphrates were the rivers of the ancient
paradise; that the mountain of Armenia, on which the ark rested, was one
of the highest mountains in the world at the deluge, as it is at
present: that the same plants and animals which exist now, existed then;
for we read of the serpent, of the raven, of the crow, and of the dove,
which brought the olive branch into the ark. Although Tournefort asserts
there are no olive trees for more than 400 miles from Mount Ararat, and
passes some absurd jokes thereon[138:A], it is nevertheless certain
there were olives in this neighbourhood at the time of the deluge, since
holy writ assures us of it in the most express terms; but it is by no
means astonishing that in the space of 4000 years the olive trees should
have been destroyed in those quarters, and multiplied in others; it is
therefore contrary to scripture and reason, that those authors have
supposed the earth was quite different from its present state before the
deluge; and this contradiction between their hypothesis and the sacred
text, as well as physical truths, must cause their systems to be
rejected, if even they should agree with some phenomena. Burnet gives
neither observations, nor any real facts, for the support of his system.
Woodward has only given us an essay, in which he promised much more than
he could perform: his book is a project, the execution of which has not
been seen. He has made use of two general observations; the first, that
the earth is every where composed of matters which formerly were in a
state of fluidity, transported by the waters, and deposited in
horizontal strata. The second, that there are abundance of marine
productions in most parts of the bowels of the earth. To give a reason
for these facts, he has recourse to the universal deluge, or rather it
appears that he gives them as proofs of the deluge; but, like Burnet, he
falls into evident contradictions, for it is not to be supposed with
them that there were no mountains prior to the deluge, since it is
expressly stated, that the waters rose fifteen cubits above the tops of
the highest mountains. On the other hand, it is not said that these
waters destroyed or dissolved these mountains; but, on the contrary,
these mountains remained in their places, and the ark rested on that
which the water first deserted. Besides how can it be imagined that,
during the short duration of the deluge, the waters were able to
dissolve the mountains and the whole body of the earth? Is it not an
absurdity to suppose that in forty days all marble, rocks, stones, and
minerals, were dissolved by water? Is it not a manifest contradiction to
admit this total dissolution, and at the same time maintain that shells,
bones, and marine productions were preserved entire, and resisted that
which had dissolved the most solid substances? I shall not therefore
hesitate to say, that Woodward, with excellent facts and observations,
has formed but a poor and inconsistent system.
Whiston, who came last, greatly enriched the other two, and
notwithstanding he gave a vast scope to his imagination has not fallen
into contradiction; he speaks of matters not very credible, but they are
neither absolutely nor evidently impossible. As we are ignorant of the
centre of the earth, he thought he might suppose it was a solid matter,
surrounded with a ring of heavy fluid, and afterwards with a ring of
water, on which the external crust was sustained; in the latter the
different parts of this crust were more or less sunk, in proportion to
their relative weights, which produced mountains and inequalities on the
surface of the earth. Here, however, this astronomer has committed a
mechanical blunder; he did not recollect that the earth, according to
this hypothesis, must be an uniform arch, and that consequently it could
not be borne on the water it contains, and much less sunk therein. I do
not know that there are any other physical errors; but he has made a
great number of errors, both in metaphysics and theology. On the whole
it cannot be denied absolutely that the earth meeting with the tail of a
comet might not be inundated, especially allowing the author that the
tail of a comet may contain aqueous vapours; nor can it be denied as an
absolute impossibility that the tail of a comet, in returning from its
perihelium, might not burn the earth, if we suppose, with Mr. Whiston,
that the comet passed very near the sun; it is the same with the rest of
the system. But though his ideas are not absolutely impossibilities,
there is so little probability to each thing, when taken separately,
that the result upon the whole taken together puts it beyond
credibility.
The three systems we have spoken of are not the only works which have
been composed on the theory of the earth; a Memoir of M. Bourguet
appeared in 1729, printed at Amsterdam, with his "Philosophical Letters
on the Formation of Salts, &c." in which he gives a specimen of the
system he meditated, but which was prevented completion by the death of
the author. It is but justice to admit, that no person was more
industrious in making observations or collecting facts. To him we owe
that great and beautiful observation, the correspondence between the
angles of mountains. He presents every thing which he had collected in
great order; but with all those advantages, it appears that he has
succeeded no better than the rest in making a physical and reasonable
history of the changes which had happened to the globe, and that he was
very wide from having found the real cause of those effects which he
relates. To be convinced of this we need only cast our eyes on the
propositions which he deduces from the phenomena, and which ought to
serve for the basis of his theory. He says, that the whole globe took
its form at one time, and not successively; that its form and
disposition prove that it has been in a state of fluidity; that the
present state of the earth is very different from that in which it was
for many ages after its first formation; that the matter of the globe
was at the beginning less dense than since it altered its appearance;
that the condensation of its solid parts diminished by degrees with its
velocity, so that after having made a number of revolutions on its axis,
and round the sun, it found itself on a sudden in a state of
dissolution, which destroyed its first structure. This happened about
the vernal equinox. That the sea-shells introduced themselves into the
dissolved matters; that after this dissolution the earth took the form
it now has, and that the fire which directly infused itself therein
consumed it by degrees, and it will be one day destroyed by a terrible
explosion, accompanied with a general conflagration, which will augment
the atmosphere of the globe, and diminish its diameter, and that then
the earth, instead of beds of sand or earth, will have only strata of
calcined metal and mountains composed of amalgamas of different metals.
This is sufficient to shew the system M. Bourguet meditated; to divine
in this manner the past, and predict the future, nearly as others have
predicted, does not appear to me to be an effort of judgment: this
author had more erudition than sound and general views: he appears to be
deficient in that capaciousness of ideas necessary to follow the extent
of the subject, and enable him to comprehend the chain of causes and
effects.
In the acts of Leipsic, the famous Leibnitz published a scheme of quite
a different system, under the title of _Protogaea_. The earth, according
to Bourguet and others, must end by fire; according to Leibnitz it began
by it, and has suffered many more changes and revolutions than is
imagined. The greatest part of the terrestrial matter was surrounded by
violent flames at the time when Moses says light was divided from
darkness. The planets, as well as the earth, were fixed stars, luminous
of themselves. After having burnt a long time, he pretends that they
were extinguished for want of combustible matter, and are become opaque
bodies. The fire, by melting the matter, produced a vitrified crust,
and the basis of all the matter which composes the globe is glass, of
which sand and gravel are only fragments. The other kinds of earth are
formed from a mixture of this sand, with fixed salts and water, and when
the crust cooled, the humid particles, which were raised in form of
vapours, refel, and formed the sea. They at first covered the whole
surface, and even surmounted the highest mountains. According to this
author, the shells, and other wrecks of the sea, which are every where
to be found, positively prove that the sea has covered the whole earth;
and the great quantity of fixed salts, sand, and other melted and
calcined matters, which are included in the bowels of the earth, prove
that the conflagration had been general, and that it preceded the
existence of the sea. Although these thoughts are void of proofs, they
are capital. The ideas have connection, the hypotheses are not
impossible, and the consequences that may be drawn therefrom are not
contradictory: but the grand defect of this theory is, that it is not
applicable to the present state of the earth; it is the past which it
explains, and this past is so far back, and has left us so few remains,
that we may say what we please of it, and the probability will be in
proportion as a man has talents to elucidate what he asserts. To affirm
as Whiston has done, that the earth was originally a comet, or, with
Leibnitz, that it has been a sun, is saying things equally possible or
impossible, and to which it would be ridiculous to apply the rules of
probability. To say that the sea formerly covered all the earth, that it
surrounded the whole globe, and that it is for this reason shells are
every where found, is not paying attention to a very essential point,
the unity of the time of the creation; for if that was so, it must
necessarily be admitted, that shell-fish, and other inhabitants of the
sea, of which we find the remains in the internal part of the earth,
existed long before man, and all terrestrial animals. Now, independent
of the testimony of holy writ, is it not reasonable to think, that all
animals and vegetables are nearly as ancient as each other?
M. Scheutzer, in a Dissertation, addressed to the Academy of Sciences in
1728, attributes, like Woodward, the change, or rather the second
formation of the globe, to the universal deluge; to explain that of
mountains, he says, that after the deluge, God chusing to return the
waters into subterraneous reservoirs, broke and displaced with his
all-powerful hand a number of beds, before horizontal, and raised them
above the surface of the globe, which was originally level. The whole
Dissertation is composed to imply this opinion. As it was requisite
these eminences should be of a solid consistence, M. Scheutzer remarks,
that God only drew them from places where there were many stones; from
hence, says he, it proceeds that those countries, like Switzerland,
which are very stony, are also mountainous; and on the contrary, those,
as Holland, Flanders, Hungary and Poland, have only sand or clay, even
to a very great depth, and are almost entirely without mountains.[147:A]
This author, more than any other, is desirous of blending Physic with
Theology, and though he has given some good observations, the
systematical part of his works is still weaker than those who preceded
him. On this subject he has even made declamations and ridiculous
witticisms, as may be seen in his _Visciam quærelæ_, &c. without
speaking of his large work in many folio volumes, _Physica Sacra_, a
puerile work, which appears to be composed less for the instruction of
men than for the amusement of children.
Steno, and some others, have attributed the cause of the inequalities of
the earth to particular inundations, earthquakes, &c. but the effects of
these secondary causes have been only able to produce some slight
changes. We admit of these causes after the first cause, the motion of
the flux and reflux, and of the sea from east to west. Neither Steno,
nor the rest, have given theory, nor even any general facts on this
matter.[148:A]
Ray pretends that all mountains have been produced by earthquakes, and
he has composed a treatise to prove it; we shall shew under the article
of Volcanos what little foundation his opinion is built upon.
We cannot dispense with observing that Burnet, Woodward, Whiston, and
most of these other authors, have committed an error which deserves to
be cleared up; which is, to have looked upon the deluge as possible by
the action of natural causes, whereas scripture presents it to us as
produced by the immediate will of God; there is no natural cause which
can produce on the whole surface of the earth, the quantity of water
required to cover the highest mountains; and if even we could imagine a
cause proportionate to this effect, it would still be impossible to find
another cause capable of causing the water to disappear: allowing
Whiston, that these waters proceeded from the tail of a comet, we deny
that any could proceed from the great abyss, or that they all returned
into it, since the great abyss, according to him, being surrounded on
every side by the crust, or terrestrial orb, it is impossible that the
attraction of the comet could cause any motion to the fluids it
contained; much less, as he says, a violent flux and reflux; hence there
could not be issued from, nor entered into, the great abyss, a single
drop of water; and unless it is supposed that the waters which fell from
the comet have been destroyed by a miracle, they would still be on the
surface of the earth, covering the summits of the highest mountains.
Nothing better characterises a miracle, than the impossibility of
explaining the effect of it by natural causes. Our authors have made
vain efforts to give a reason for the deluge; their physical efforts,
and the secondary causes, which they made use of, prove the truth of the
fact as reported in the scriptures, and demonstrate that it could only
have been performed by the first cause, the will of the Almighty.
Besides, it is certain that it was neither at one time, nor by the
effect of the deluge, that the sea left dry these continents we inhabit:
for it is certain by the testimony of holy writ, that the terrestrial
paradise was in Asia, and that Asia was inhabited before the deluge;
consequently the sea, at that time, did not cover this considerable part
of the globe. The earth, before the deluge, was nearly as it is at
present, and this enormous quantity of water, which divine justice
caused to fall on the earth to punish guilty men, in fact, brought death
on every creature; but it produced no change on the surface of the
earth, it did not even destroy plants which grew upon it, since the dove
brought an olive branch to the ark in her beak.
Why, therefore, imagine, as many of our naturalists have done, that this
water totally changed the surface of the globe even to a depth of two
thousand feet? Why do they desire it to be the deluge which has brought
the shells on the earth which we meet with at 7 or 800 feet depth in
rocks and marble? Why say, that the hills and mountains were formed at
that time? And how can we figure to ourselves, that it is possible for
these waters to have brought masses and banks of shells 100 miles long?
I see not how they can persist in this opinion, at least, without
admitting a double miracle in the deluge; the first, for the
augmentation of the waters; and the second, for the transportation of
the shells; but as there is only the first which is related in the
Bible, I do not see it necessary to make the second an article of our
creed.
On the other hand, if the waters of the deluge had retired all at once,
they would have carried so great a quantity of mud and other impurities,
that the Earth would not have been capable of culture till many ages
after this inundation; as is known, by the deluge which happened in
Greece, where the overflowed country was totally forsaken, and could not
receive any cultivation for more than three centuries.[151:A] We ought
also to look on the universal deluge as a supernatural means of which
the Almighty made use for the chastisement of mankind, and not as an
effect of a natural cause. The universal deluge is a miracle both in its
cause and effects; we see clearly by the scripture that it was designed
for the destruction of men and animals, and that it did not in any mode
change the earth, since after the retreat of the waters, the mountains,
and even the trees, were in their places, and the surface of the earth
was proper to receive culture and produce vines and fruits. How could
all the race of fish, which did not enter the ark, be preserved, if the
earth had been dissolved in the water, or only if the waters had been
sufficiently agitated to transport shells from India to Europe, &c.?
Nevertheless, this supposition, that it was the deluge which transported
the shells of the sea into every climate, is the opinion, or rather the
superstition, of naturalists. Woodward, Scheutzer, and some more, call
these petrified shells the remains of the deluge; they look on them as
the medals and monuments which God has left us of this terrible event,
in order that it never should be effaced from the human race. In short,
they have adopted this hypothesis with so much enthusiasm, that they
appear only desirous to reconcile holy scripture with their opinion; and
instead of making use of their observations, and deriving light
therefrom, they envelope themselves in the clouds of a physical
theology, the obscurity of which is derogatory to the simplicity and
dignity of religion, and only leaves the absurd to perceive a ridiculous
mixture of human ideas and divine truths. To pretend to explain the
universal Deluge, and its physical causes; to attempt to teach what
passed in the time of that great revolution; to divine what were the
effects of it; to add facts to those of Holy Writ, to draw consequences
from such facts, is only a presumptuous attempt to measure the power of
the Most High. The natural wonders which his benevolent hand performs in
an uniform and regular manner, are incomprehensible; and by the
strongest reason, these wonderful operations and miracles ought to hold
us in awful wonder, and in silent adoration.
But they will say, the universal Deluge being a certain fact, is it not
permitted to reason on its consequences? It may be so; but it is
requisite that you should begin by allowing that the Deluge could not be
performed by physical causes; you ought to consider it is an immediate
effect of the will of the Almighty; you ought to confine yourselves to
know only what the Holy Writ teaches, and particularly not to blend bad
philosophy with the purity of divine truth. These precautions, which the
respect we owe to the Almighty exacts, being taken, what remains for
examination on the subject of the Deluge? Does the Scripture say
mountains were formed by the Deluge? No, it says the contrary. Is it
said that the agitation of the waters was so great as to raise up shells
from the bottom of the sea, and transport them all over the earth? No;
the ark floated quietly on the surface of the waters. Is it said, that
the earth suffered a total dissolution? None at all: the recital of the
sacred historian is simple and true, that of these naturalists complex
and fabulous.
FOOTNOTES:
[138:A] Voyage du Levant, vol. 2, page 336.
[147:A] See the Hist. of the Acad. 1708, page 32.
[148:A] See the Diss. de Solido intra Solidum, &c.
[151:A] See Acta erudit, Lepiss, Ann. 1691, page 100.
ARTICLE VI.
GEOGRAPHY.
The surface of the Earth, like that of Jupiter, is not divided by bands
alternative and parallel to the equator; on the contrary, it is divided
from one pole to the other, by two bands of earth, and two of sea; the
first and principal is the ancient continent, the greatest length of
which is found to be in a line, beginning on the east point of the
northern part of Tartary, and extending from thence to the land which
borders on the gulph of Linchidolkin, where the Muscovites fish for
whales; from thence to Tobolski, from Tobolski to the Caspian sea, from
the Caspian sea to Mecca, and from Mecca to the western part of the
country inhabited by the Galli, in Africa; afterwards to Monoemuci or
Monomotapa, and at last to the Cape of Good Hope; this line, which is
the greatest length of the old continent, is about 3600 leagues, Paris
measure; it is only interrupted by the Caspian and Red seas, the
breadths of which are not very considerable, and we must not pay any
regard to these interruptions, when it is considered, the surface of the
globe is divided only in four parts.
This greatest length is found by measuring the old continent diagonally;
for if measured according to the meridians, we shall find that there are
only 2500 leagues from the northernmost Cape of Lapland to the Cape of
Good Hope; and that the Baltic and Mediterranean cause a much greater
interruption than is met with in the other way. With respect to all the
other distances that might be measured in the old continent under the
same meridian, we shall find them to be much smaller than this; having,
for example, only 1800 leagues from the most southern point of the
island of Ceylon to the northernmost coast of Nova Zembla. Likewise, if
we measure the continent parallel to the equator, we find that the
greatest uninterrupted length is found from Trefna, on the western coast
of Africa, to Ninpo, on the eastern coast of China, and that it is about
2800 leagues. Another course may be measured from the point of Brittany
near Brest, extending to the Chinese Tartary; about 2300 leagues. From
Bergen, in Norway, to the coast of Kamschatka, is no more than 1800
leagues. All these lines have much less length than the first, therefore
the greatest extent of the old continent, is, in fact, from the eastern
point of Tartary to the Cape of Good Hope, that is about 3600 leagues.
There is so great an equality of surface on each side of this line,
which is also the longest, that there is every probability to suppose it
really divides the contents of the ancient continent; for in measuring
on one side is found 2,471,092-3/4 square leagues, and on the other
2,469,687.
Agreeable to this, the old continent consists of about 4,940,780 square
leagues, which is nearly one-fifth of the whole surface of the globe,
and has an inclination towards the equator of about 30 degrees.
The greatest length of the new continent may be taken in a line from the
mouth of the river Plata to the lake of Assiniboils. From the former it
passes to the lake Caracara; from thence to Mataguais, Pocona, Zongo,
Mariana, Morua, St. Fe, and Carthagena; it then proceeds through the
gulph of Mexico, Jamaica, and Cuba, passes along the peninsula of
Florida, through Apolache, Chicachas, and from thence to St. Louis, Fort
le Suer, and ends on the borders of lake Assiniboils; the whole extent
of which is still unknown.
This line, which is interrupted only by the Mexican gulph (which must be
looked upon as a mediterranean sea) may be about 2500 leagues long, and
divides the new continent into nearly two equal parts, the left of which
contains about 1,069,286-5/6 leagues square, and that on the right about
1,070,926-1/12; this line, which forms the middle of the band of the new
continent, is inclined to the equator about 30 degrees, but in an
opposite direction, for that of the old continent extends from the
north-east to the south-west, and that of the new continent from the
north-west to the south-east. All those lands together of the old and
new continent, make about 7,080,993 leagues square, which is not near
the third of the whole surface, which contains 25 millions of square
leagues.
It must be remarked, that these two lines, which divide the continents
into two equal parts, both terminate at the same degree of southern and
northern latitude, and that the two continents make opposite
projections, which exactly face each other; to wit, the coasts of
Africa, from the Canary islands to the coasts of Guinea, and those of
America from Guiana to the mouth of Rio Janeiro.
It appears, therefore, that the most ancient land of the globe, is on
the two sides of these lines, at the distance of from 2 to 250 leagues
on each side. By following this idea, which is founded on the
observations before related, we shall find in the old continent that the
most ancient lands of Africa are those which extend from the Cape of
Good Hope to the Red Sea, as far as Egypt, about 500 leagues broad, and
that, consequently, all the western coasts of Africa, from Guinea to the
straits of Gibraltar, are the newest lands. So likewise we shall
discover that in Asia, if we follow the line on the same breadth, the
most ancient lands are Arabia Felix and Deserta, Persia, Georgia,
Turcomania, part of Tartary, Circassia, part of Muscovy, &c. that
consequently Europe, and perhaps also China, and the eastern part of
Tartary, are more modern. In the new continent we shall find the Terra
Magellanica, the eastern part of Brasil, the country of the Amazons,
Guiana, and Canada, to be the new lands, in comparison with Peru, Terra
Firma, the islands in the gulph of Mexico, Florida, the Mississippi, and
Mexico.
To these observations we may add two very remarkable facts, the old and
new continent are almost opposite each other; the old is more extensive
to the north of the equator than the south; the new is more to the south
than the north. The centre of the old continent is in the 16th or 18th
degree of north latitude, and the centre of the new is in the 16th or
18th degree south latitude, so that they seem to be made to
counterbalance each other. There is also a singular connexion between
the two continents, although it appears to be more accidental than those
which I have spoken of, which is, that if the two continents were
divided into two parts, all four would be surrounded by the sea, if it
were not for the two small isthmuses, Suez and Panama.
This is the most general idea which an attentive inspection of the globe
furnishes us with, on the division of the earth. We shall abstain from
forming hypotheses thereon, and hazarding reasonings which might lead
into false conclusions; but no one as yet having considered the
division of the globe under this point of view, I shall submit a few
remarks. It is very singular that the line which forms the greatest
length of the terrestrial continents divides them also into two equal
parts; it is no less so that these two lines commence and end at the
same degrees of latitude, and are both alike inclined to the equator.
These relations may belong to some general conclusions, but of which we
are ignorant. The inequalities in the figure of the two continents we
shall hereafter examine more fully: it is sufficient here to observe,
that the most ancient countries are the nearest to these lines, and are
the highest; that the more modern lands are the farthest, and also the
lowest. Thus in America, the country of the Amazons, Guiana and Canada
will be the most modern parts; by casting our eyes on the map of this
country we see the waters on every side, and that they are divided by
numberless lakes and rivers, which also indicates that these lands are
of a late formation; while on the other hand Peru and Mexico are high
mountains, and situate at no great distance from the line that divides
the continent, which are circumstances that seem to prove their
antiquity. Africa is very mountainous, and that part of the world is
also very ancient. There are only Egypt, Barbary, and the western coasts
of Africa, as far as Senegal, in this part of the globe, which can be
looked upon as modern countries. Asia is an old land, and perhaps the
most ancient of all, particularly Arabia, Persia, and Tartary; but the
inequalities of this vast part of the globe, as well as those of Europe,
we will consider in a separate article. It might be said in general,
that Europe is a new country, and such position would be supported both
by the universal traditions relative to the emigrations of different
people, and the origin of arts and sciences. It is not long since it was
filled with morasses, and covered with forests, whereas in the land
anciently inhabited, there are but few woods, little water, no morasses,
much land, and a number of mountains, whose summits are dry and barren;
for men destroy the woods, drain the waters, confine rivers, dry up
morasses, and in time give a different appearance to the face of the
earth, from that, of uninhabited or newly-peopled countries.
The ancients were acquainted with but a small part of the globe. All
America, the Magellanic, and a great part of the interior of Africa,
was entirely unknown to them. They knew not that the torrid zone was
inhabited, although they had navigated around Africa, for it is 2200
years since Neco, king of Egypt, gave vessels to the Phenicians, who
sailed along the Red Sea, coasted round Africa, doubled the Cape of Good
Hope, and having employed two years in this voyage, the third year they
entered the straits of Gibraltar.[163:A] The ancients were unacquainted
with the property of the loadstone, if turned towards the poles,
although they knew that it attracted iron. They were ignorant of the
general cause of the flux and reflux of the sea, nor were they certain
the ocean surrounded the globe; some indeed suspected it might be so,
but with so little foundation, that no one dared to say, or even
conjecture, it was possible to make a voyage round the world. Magellan
was the first who attempted it in the year 1519, and accomplished the
great voyage in 1124 days. Sir Francis Drake was the second in 1577, and
he performed it in 1056 days; afterwards Thomas Cavendish made this
great voyage in 777 days, in the year 1586. These celebrated navigators
were the first who demonstrated physically the sphericity and the
extent of the earth's circumference; for the ancients had no conception
of the extent of this circumference, although they had travelled a great
deal. The trade winds, so useful in long voyages, were also unknown to
them; therefore we must not be surprised at the little progress they
made in geography. Notwithstanding the knowledge we have acquired by the
aid of mathematical sciences, and the discovery of navigators, many
things remain still unsettled, and vast countries undiscovered. Almost
all the land on the side of the Atlantic pole is unknown to us; we only
know that there is some, and that it is separated from all the other
continents by the ocean. Much land also remains to be discovered on the
side of the Arctic pole, and it is to be regretted that for more than a
century the ardour of discovering new countries is extremely abated.
European governments seem to prefer, and possibly with reason,
increasing the value of those countries we are acquainted with to the
glory of conquering new ones.
Nevertheless, the discovery of the southern continent would be a great
object of curiosity, and might be useful. We have discovered only some
few of its coasts; those navigators who have attempted this discovery,
have always been stopt by the ice. The thick fogs, which are in those
latitudes, is another obstacle; yet, in defiance of these
inconveniencies, it is probable that by sailing from the Cape of Good
Hope at different seasons, we might at last discover a part of these
lands, which hitherto make a separate world.
There is another method, which possibly might succeed better. The ice
and fogs having hitherto prevented the discovery, might it not be
attempted by the Pacific Sea; sailing from Baldivia, or any other port
on the coast of Chili, and traversing this sea under the 50th degree
south latitude? There is not the least appearance that this navigation
is perilous, and it is probable would be attended with the discovery of
new countries; for what remains for us to know on the coast of the
southern pole, is so considerable, that we may estimate it at a fourth
part of the globe, and of course may contain a continent, as large as
Europe, Asia, and Africa, all together.
As we are not at all acquainted with this part of the globe, we cannot
justly know the proportion between the surface of the earth and that of
the sea; only as much as may be judged by inspection of what is known,
there is more sea than land.
If we would have an idea of the enormous quantity of water which the sea
contains, we must suppose a medium depth, and by computing it only at
200 fathom, or the sixth part of a league, we shall find that there is
sufficient to cover the whole globe to the height of 600 feet of water,
and if we would reduce this water into one mass, it would form a globe
of more than 60 miles diameter.
Navigators pretend, that the latitudes near the south pole are much
colder than those of the north, but there is no appearance that this
opinion is founded on truth, and probably has been adopted, becaus
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