[6] The old English lawyers puzzled themselves greatly in tracing the
origin of the feudal tenures. The truth is, they may be found in the
incipient stages of society in nearly every nation. They existed, in
fact, in Hindostan, China, and many other countries, for centuries
before the time of the _comites_ of the German princes, mentioned by
Tacitus, who are supposed to have founded them. The services of the
tenant varied according to the character and condition of the
people--the principle was every where the same.
[7] The tael is $1.66; the pecul, 133-1/3 pounds.
ART. IV.--_Precis de la Geographie Universelle ou Description de toutes
les parties du Monde, sur un plan Nouveau D'apres les grandes divisions
Naturelles du Globe, &c._ Par MALTE-BRUN: Bruxelles, 1829.
We place at the head of our article, which we mean to devote to Physical
Geography, the title of the latest edition that we have seen of the
great work of Malte-Brun. This, which has already become well known to
our American public in translation, has received some additions from its
Belgian editors, but has not been fully brought up to the present state
of Science, nor does it contain all the new discoveries which have been
made in that part, namely, physical geography, to which our attention is
more immediately directed. We shall, however, endeavour to supply these
deficiencies so far as lies in our power.
Physical geography stands in immediate connexion with subjects which
have already been presented to the readers of this journal, namely with
Celestial Mechanics,[8] and with the Phenomena of our Atmosphere.[9] It
shall be our endeavour to proceed from the facts laid down in the first
of the two articles to which we have referred, to the more particular
consideration of the state, the structure, and the condition of the
globe we inhabit.
The earth is a planet of the solar system, the third in distance from
the sun, revolving upon its own axis, and around that central body
attended by a satellite; circumstances which affect in a most important
manner the phenomena that are observed upon its surface. Composed of
material substances that mutually attract each other, each particle of
which has a greater or less centrifugal force in proportion to its
distance from the axis of rotation, it has a figure that is consistent
with a state of equilibrium under the joint action of these two forces,
and which is such as would have been assumed by a fluid body actuated by
them. The figure that fulfils these conditions is an oblate spheroid,
the axis of the generating ellipse coinciding with the polar diameter of
the body. Had the earth a figure absolutely spherical, or less flattened
than is consistent with the conditions of equilibrium, the ocean, by
which so large a part of its surface is covered, would have arranged
itself in a meniscoid zone around its equatorial regions; were the
figure, on the other hand, one of greater oblateness, the waters would
have been divided and accumulated at either pole, leaving the
equatorial regions dry. But did its figure fulfil the conditions of
equilibrium, the fluid mass would tend to distribute itself equally over
the whole surface, unless prevented by irregularities in the solid mass.
The last is the actual state of things; the ocean occupies a bed formed
of cavities, lying below the mean surface of the spheroid, and the land
presents to us those asperities and elevations, which rise, although to
a comparatively small height, above the general level.
Was then the earth originally in a fluid state, and has it assumed its
present form under the strict action of mechanical laws, on a body of
that class? are the bed of the ocean and the continents merely crusts
formed upon the surface of a liquid globe? Does the interior still
remain liquid, or has the induration proceeded until the whole internal
mass has become solid? Nay, may not the interior be hollow, as we have
recently seen gravely maintained, and heard sage legislatures recommend
to the public attention?
Mathematical investigations of incontrovertible evidence, show us that
were the earth of equal density throughout, the flattening at the poles
would be 1/234 of the equatorial diameter; that in the hypothetical case
of infinite density at the centre, and infinite rarity at the surface,
the flattening would be no more than 1/578; while, were the surface more
dense than the interior, or did a cavity exist within, the oblateness
must be greater than 1/234. Actual measurements of portions of the
surface, the variation in the length of the pendulum which beats seconds
in different latitudes, and the effect of the earth's figure on the
lunar motions, show us that the earth cannot be flattened more than
1/289, nor less than 1/312, or may, at a mean, be considered as a
spheroid, whose polar and equatorial diameters are in the relation of
299 to 300.
Astronomers have ascertained the deflection of plumb lines from the
vertical, by the action of mountains. The attraction of a projecting
mass of known bulk and density, with one whose bulk alone is known, is
thus determined, and hence the density of the latter may be calculated.
Even comparatively small masses of matter may be placed under such
circumstances at the surface of the earth, that their mutual action can
be observed uninfluenced by the preponderating attraction of the earth,
and thus a new means of comparison obtained.
The pendulum whose vibrations ought to vary according to a definite law,
as we recede from the surface of the earth, has that law affected by the
elevated ground on which it is placed, and here again a comparison may
be instituted between the general and local attractions.
All these modes of investigation concur in, and confirm the general
result, that the mean density of the earth is about five times as great
as that of water. Now as a great portion of the surface is composed of
that fluid, and as the general density of the land is little more than
twice as great as that of water, it follows incontestably that the
interior of the earth is far more dense than its outer covering.
All material substances are capable of assuming, under proper
modifications of latent heat, either the solid, the liquid, or the
gaseous form; yet all are beyond doubt composed of atoms, solid, hard,
and incapable of further division. Under their own mutual attraction
these particles tend to unite, and cohere in solid masses, and to this
attractive force the repulsive power of heat is constantly opposed,
tending to prevent their aggregation, and retaining them, according to
its intensity, in the gaseous or liquid form.
The heat necessary to maintain these states of existence in bodies, may
be produced in various ways. Our usual experience leads us to consider
it as more generally arising from two causes, radiation from the sun,
and the chemical action causing combustion. The former could never have
produced the temperature known to exist at present upon the surface of
the globe, for the earth radiates as well as the sun, and is constantly
throwing off heat into the surrounding space. We know that these two
actions have for twenty centuries exactly balanced each other, and that
the mean temperature of the earth has neither increased nor diminished
in all that period. Had the solar radiation been, previously to that
epoch, in excess, it must at the more recent periods, counted backwards,
have been but slightly so, and ages unnumbered must have elapsed, before
the state of equilibrium which now exists could have been reached. The
earth too, at distant periods, must have been colder than at present,
while that the contrary is true is shown by numerous observations.
Neither could chemical action have had any great agency in establishing
the present temperature of the earth. The substances which burn are but
a small portion of the crust of the earth, and their combustion, if all
fired at a time, would cause no perceptible effect on the sensible heat
of the surface of our globe. Were combustible bodies even infinitely
more abundant, the supporters are insufficient to keep up their
combustion for any length of time, without sensible diminution, and this
would be the case, even were the whole of the oxygen that now exists as
a component of the waters of the ocean added to their present amount. It
is indeed possible that the outer shell of the earth, which is no more
than a crust of oxidated matter, may have existed at first in the
metallic state, but that crust has long intervened, and prevented any
contact between the air or ocean, and the metallic bases of the earths,
that in this case must lie beneath.
In spite of these obvious objections to their theory, some geologists
have madly fancied to themselves a great internal fire, maintained by
actual combustion, a fancy but little more rational than that which
seeks, in the present order of things, precipitation from some vast
quantity of a liquid menstruum, every trace of whose existence has now
vanished.
There is, however, yet another source of heat, if indeed solar heat be
not a mere case of its general action, far more general and universal,
which has its origin in the bodies themselves, and has no reference to
any extrinsic cause. All bodies are sensibly heated when condensed, and
lose sensible heat when they expand, so that their temperatures vary
with the greater or less distance of their particles. The atmosphere of
the earth furnishes a marked illustration of this fact. Of nearly
uniform chemical composition throughout, its elastic nature, conflicting
with its gravity, renders it more dense in its lower than in its higher
regions. The former are in consequence warmer than the latter, and the
mean temperature of our climates is in fact due to this character of our
atmosphere. But this mean temperature could not be maintained, were not
that of the earth itself in harmony with it. The surface might, no
doubt, be cooled or heated by the adjacent air, but the heat, if given
out from an earth warmer than the atmosphere, would be rapidly replaced
from within, and a constant accumulation ensue in the air, while, if the
earth were cooler, a diminution, equally constant, of the temperature of
the atmosphere, must take place. The earth is, however, itself subject
to the same law. All the materials of which it is composed, are capable
of compression, in a greater or less degree, and of being heated by
compression. The tendency of all material substances to the centre of
attraction, loads the parts nearest to that centre with the whole weight
of the superincumbent mass. And in the depth of four thousand miles,
which intervenes between the centre and the surface, the heat must be
far more than equal to that obtained by the compound blow-pipe or
galvanic deflagrator, under whose intense energies the most refractory
substances liquefy. Hence it may be inferred as a fact, as certain as
any in physical science, that the interior of the earth is at present in
a state resembling igneous fusion, not produced, however, by any of the
more familiar sources of heat, but by the intense pressure the upper
masses exert upon those nearer to the centre.
Here, then, we find the reason of the earth's having assumed a figure
consistent with the equilibrium of a fluid mass, whose particles are
endued with a mutual attraction, and which has a motion around an axis.
Let us suppose all the particles which now constitute the earth, to have
been originally disseminated throughout a vast space, and to have
approached their common centre of gravity by the force of mutual
attraction; the consideration thus caused would have produced the state
of intense heat that is now kept up within by pressure; and the
conducting power of the bodies would have propagated the heat nearly
equal throughout the mass. The surface would then have existed in a
liquid state as well as that beneath. But as the radiation from the
surface of a heated body is in exact proportion to its temperature, this
cause of cooling would have been intense, and a crust must soon have
formed upon the outer surface; this crust would have increased in
thickness so long as the heat thrown off by radiation exceeded that
received from the sun. When this state of equilibrium was finally
attained, all the great phenomena which a body thus heated could
exhibit, would cease, and the subsequent changes would become due only
to forces such as we now see acting upon the surface, or would be the
completion of actions commenced during the previous state.
We know, from astronomical investigations, that this state of
equilibrium has existed for upwards of twenty centuries, while analogy
would lead us to infer that it must have been attained at no long period
after the last great catastrophe to which our planet was subjected.
Let us now see whether the fact of the interior of the globe being more
intensely heated than its surface, can be inferred in any other manner
than from the course of reasoning whose principles are here cited. The
feeble power of man, feeble at least compared to the size of the globe
he inhabits, has been able to penetrate to but small depths in its outer
shell, but even at these small depths, an increase of temperature has
been remarked, and so frequently and carefully observed, as to leave no
doubt of its being a general law. This increase, too, appears exactly
consistent with that which it might be inferred ought to take place. But
we, even to the present day, occasionally see the igneous fluid from
beneath forced up to the surface, and spreading from volcanic craters
over great regions. Observation shows us that at remote epochs such
phenomena were much more frequent than at present. We want no more
positive proofs that the interior of the earth is still intensely
heated, and that the bed of the ocean and the solid land are mere crusts
formed upon the surface of a mass in a state analogous to that of
igneous fusion.
Were the surface, as we have inferred it must have been, ever itself
intensely heated, the volatile and gaseous matters which now constitute
our atmosphere and oceans, must have united to form an atmosphere of far
greater extent than it is at present. The aqueous matter rising into
regions where the rarity of the air would cause cold sufficient to
condense it, would have been in a state of constant motion, boiling in
the lower regions, being precipitated in the higher, and acting most
energetically to promote the general cooling. And so soon as the surface
became cooler than 212 deg., the water would begin to settle upon its
surface, forming at first lakes in its basins or cavities, and finally
extending itself into one vast ocean, covering the whole or parts of the
solid crust according to its greater or less degree of uniformity.
The conversion of the igneous liquid surface into solid matter, could
only have taken place in successive shells or concentric layers; hence
would arise a stratified character. And as the cooling proceeded,
lowering the mean temperature of the whole mass, a consequent diminution
of bulk must have taken place, according to the well known law of
expansion by heat and contraction on cooling. Such diminution in bulk
must have broken the strata into fragments, through the fissures of
which, according to the laws of hydrostatics, the fluid mass beneath
would rise until the equilibrium of rotation would have been obtained,
and the strata, originally concentric, would be dislocated and turned in
every possible direction, pierced with veins and dikes of all possible
magnitude, from slender threads to mountain masses, caused by the
cooling and consolidation of the rising fluid, and occasionally
spreading in overlying currents, congealed and fixed in ridges and
chains. These veins and dykes would present different characters,
according to the dates of their elevation. If raised at a period when
the surface was still of high temperature, they must have crystallized
slowly, and in a perfect manner; at diminished temperatures, the
crystallization would be less complete; if raised into the mass of
ocean, they would assume one character; if coming in contact with air,
another. A breaking of the bed of the ocean, and bringing its waters in
contact with the liquid mass beneath, might produce consequences
extending in their action to districts of the globe, the most remote
from those in which the convulsion occurred; for the water, rising into
vapour, would tend to extend itself in one uniform atmosphere over the
whole surface of the globe, and might be precipitated in unusual
abundance wherever causes of condensation existed. Thus, partial, or
even total deluges, may have occurred, great portions of the ocean being
hurried in vapour from its bed, and precipitated upon the land whose
temperature is not affected by the distant catastrophe.
The waters might, in some cases, flow directly back to the ocean, in
others might accumulate in basins and form lakes, fresh at first, and
gradually becoming saline. These in turn might burst their bounds,
carrying ruin and devastation in their course, or might by evaporation
be dried up, and be again filled by a recurrence of the original cause
of supply.
Such violent and rapid action would finally be exhausted by the gradual
cooling of the earth, but the outer crust would still press on the
igneous fluid beneath, and although far less liable to rupture, its
fluid action might yet enable it to force its way occasionally to the
surface, but at distant intervals, and with diminished energy. Now, a
new series of phenomena must occur, similar to the more familiar of
those we see acting at present; at first more intense, but finally, when
the state of equilibrium of temperature is reached, exactly such as we
now find them both in kind and in energy.
To see how far such a view of what might have occurred, under the action
of well known causes, in case of a certain original order of things, is
correct, let us examine the appearances our globe actually presents.
To a systematized and general examination, it presents the appearance of
a great ocean, covering about three-fourths of its whole surface, and
surrounding two great, and a number almost infinite of smaller islands.
The two great islands are the old and the new continents; the largest of
those that remain is New-Holland. To exhibit this great ocean in its
most general aspect, take an artificial globe, raise the south pole 50 deg.
above the horizon, and bring New-Zealand to the meridian. The hemisphere
above the horizon will now be wholly of water, with the exception of the
southern part of South America on the one side, and New-Holland, with
the Indian archipelago, on the other. These bear, when united, but a
small proportion to the entire hemisphere. The opposite hemisphere
contains more land than water; and when it is in its turn placed above
the horizon, the Atlantic will be seen lying almost wholly on the
western side of the meridian, and forming, with the Arctic ocean, a
species of channel, narrowing from the latitude of the Cape of Good Hope
towards the northern pole, and communicating with the great ocean which
lies principally in the opposite hemisphere by Behring's straits. On
this hemisphere are also seen parts of the Pacific and Indian oceans,
which are considerably more than equal in surface to the lands which
project into the opposite one.
If we turn our attention to the land, we find it unequal in its surface;
and although compared with the whole diameter of the earth, the
inequalities be very small, yet, compared with our own stature, they
often present an imposing magnitude. These greater elevations are
mountains; and we find them sometimes united in chains, sometimes
isolated, and at other times uniting to form elevated plains or table
lands. These table lands sometimes slope outwards, at others they are
surrounded by eminences that prevent the efflux of the waters, or only
admit them to pass through apertures made by their own action. Upon our
continent, table lands of the latter description are to be found of
great magnitude, entering as parts of the great system of the
Cordilleras or Andes; in Europe they are rare, but in Tartary, Persia,
and in central Africa, they occur, forming regions of great extent. In
general, the greater part of the mountains of a continent appear to have
a connexion more or less obvious; it has even been conceived that they
form the skeleton upon which the rest of the land has been deposited,
and which has determined the form of the continent. Thus we speak
habitually of chains of mountains. Mountains, however, do not always
present a continuous ridge, from which the peaks or more elevated
summits rise, but occasionally, the groups we call chains, are composed
of separate mountains divided by valleys; such are the mountains of
Scotland, of Sweden, and Norway; and such is the general structure of
the chain of mountains called in the state of New-York the Highlands, of
whose connexion and grouping we shall hereafter speak.
This being understood, namely, that by a chain or ridge of mountains we
do not necessarily intend a continuous elevation, the term may be
conveniently used in order to express the configuration of mountains.
These chains surround or border upon greater or less basins, which are
each distinguished by the name of the principal stream that conveys its
surface waters to the ocean, or they may, as has been stated, envelop a
table land, whence there is no issue for the waters, or no more than a
mere passage sufficient to afford them an outlet. Even if a map contain
no expression of the position of mountains, we can, by mere inspection
of the courses of rivers, determine the lines in which the chains are
directed, and, from the size of the rivers, judge in some measure of the
elevation of the district. Thus, on inspection of the map of Europe, we
find four of its greatest rivers rising at no great distance from each
other, the Rhine, the Rhone, the Danube, and the Po; here, then, we
might infer a great elevation, and here we accordingly find its highest
mountains, the Alps. In another part of this continent, we see the
Dwina, the Nieper, and the Volga, diverge from points not far distant
from each other, and here accordingly we find an elevated table land,
two hundred miles in length by fifty in breadth, marked however by no
mountain summits. In central Asia, we see a vast space inclosed by lines
joining the sources of a number of mighty rivers, the Indus, the Ganges,
the Barrampooter, the Irrawaddy, the Houng Ha, and Kiang Ku, the Amour,
the Lena, the Yermisir, and the Oby; accordingly, here we find the
greatest table land surrounded by the highest mountains of the globe.
Still, however, the instance we have cited of the rivers of Russia
shows, that the land whence great rivers take their rise, is not
necessarily mountainous; in this case the ascent is almost
imperceptible, and the summit offers the aspect of a level and marshy
plain. Such also occurs in the famous boundary between the United
States and Canada, where the highlands that figured in two successive
treaties have disappeared, and in their supposed place has been found a
series of swamps.
Attempts have been made to arrange the chains of mountains into
connected systems. Of these the most successful is that of Malte-Brun.
"If we draw a line from the centre of Thibet, across Chinese
Mongolia towards Ochotsk, and thence towards Cape Tchutscki,
the eastern promontory of Asia, this line will in general
coincide with a great chain of mountains which runs from the
south-west to the north-east, and which every where descends
rapidly towards the Indian and Pacific oceans, while on the
contrary, it extends itself towards the Frozen ocean in high
plains and secondary hills. It is probable that we may some day
refer to the same rule the chain of Lapata, called the backbone
of the world, in Africa; at any rate this chain runs from the
Cape of Good Hope to that of Gardafui, in a direction
south-east and north-west, and therefore in nearly the same
direction as the great chain of Asia, but we are ignorant of
the disposition of the slopes of these mountains. We may regard
the mountains of the Happy Arabia, which are both steep and
lofty, as the link that connects the mountains of Lapata with
the table lands and mountains of Persia, which proceed from the
mountains of Thibet.
"If we follow the western coasts of America, from Behring's
straits, which hardly form a sensible interruption, to Cape
Horn, we find an uninterrupted chain of mountains. From time to
time this chain retires a little into the interior, but more
frequently it immediately borders upon the great ocean, in
immense cliffs, and often by frightful precipices. On the other
side of it, the manner in which the lakes discharge themselves,
and the direction of the great rivers, show sufficiently, that
the surface of America inclines gently towards the Atlantic
ocean.
"It results from a combination of these observations, that the
greatest chains of mountains on our globe, are ranged in an arc
of a circle around the great ocean, and the sea of India; that
they seem to present rapid descents towards the immense basin
they surround, and gentle slopes on their opposite sides; in
fine, from the Cape of Good Hope to Behring's straits, and
thence to Cape Horn, the eye of the most timid observer cannot
fail to see some trace of an arrangement, as surprising from
its uniformity, as from the vast extent of ground which it
embraces.
"Let us pause for an instant to consider this great fact of
physical geography. If we conceive ourselves placed in New
South Wales, with our face turned towards the north, we have
America on our right hand, Africa and Asia on our left. These
continents, which we hardly before ventured to approach in our
imagination, considered in this point of view, form a
consistent system, whose structure, as far as we are acquainted
with it, presents in its great features an astonishing
symmetry. A chain of enormous mountains surrounds an enormous
basin; this basin, divided into two by a vast collection of
islands, often bathes with its waves the feet of this great
primary chain of the earth."
In this chain lie the greatest mountains of the globe. One peak of the
Himmalayah rises nearly five miles above the level of the sea; another
has a height of 25,500 feet; and a third of 22,217 feet. In South
America are Soratu, in height 25,250 feet.
Illimani, 24,000
Chimborazo, 21,400
not to mention Antisana, Mauflos, Chillau, Cotopaxi, all of which exceed
in height any mountains that do not lie in this great system. Nay, did
not the great Volcano of Owyhee enter into the order with a height of
18,000 feet, the list of those surpassing the other mountains of the
globe, might be very much extended.
We shall have occasion hereafter to speak of the volcanic energies still
exerted in this vast stony girdle, and shall therefore confine ourselves
strictly to mere external form.
The arms and branches of mountain chains enclose as has been seen,
basins marked by rivers which convey their surface waters to the ocean.
The rains which fall on the sides of mountains and hills, unite in
torrents and streams, which follow the lines of most rapid slope in
their course to the sea.
The greater rivers mark the lowest part of a principal basin, on each
side of which, at a greater or less distance, are to be found rising
grounds, themselves hollowed out into lateral secondary basins,
containing courses of water less considerable than the first, into which
they cast themselves, and whose branches they are. The borders of these
secondary basins are again hollowed out into basins of a third order,
whose slopes also contain water courses less considerable than the
preceding, into which they in turn discharge themselves. This
ramification continues until we reach the smallest ravines of the
boundary mountains, and the map appears, as it were, covered with a net
work of rivers and lesser streams. The great valley of the Mississippi
and Missouri, forms perhaps the most striking instance of this sort,
upon the surface of our globe.
Rivers and streams are constantly exerting a mechanical action on the
surfaces over which they run; abrading and tearing off fragments even of
the hardest rocks, they roll them in their course until the velocity
becomes insufficient to transport them farther. At diminished velocities
they move fragments of less size, down to the smallest pebbles; at still
less velocities, they transport sand, and finally earthy matter, in the
most minute division. These are deposited in succession in positions
corresponding to the rapidity of the stream, and hence the beds of
rivers present at each of their different sections, materials of
magnitude and quality corresponding to the rate at which the stream
usually flows. The increase in the magnitude of streams, due to violent
rains and the melting of the snows, changes the position of the
substances that compose their bed, and the more easily suspended
materials are often held until the stream actually meets the ocean. In
such sudden increases, the streams often overflow their usual banks, and
make their deposits laterally, until the constant succession of such
deposits raises the adjacent ground high enough to set bounds to the
further spreading of the stream. This deposit is remarkable for its
taking place in greatest quantity close to the usual bed of the stream;
and thus it speedily opposes natural dykes to its own redundant waters.
This action is most conspicuous at points where marked changes take
place either permanently or periodically in the rapidity of running
water: when streams descend from mountains into lines of less descent, a
deposit uniformly takes place, forming _flats_ or _intervals_, as they
are styled in the United States, of which we have such beautiful
instances in the valleys of the Connecticut and Mohawk, and that part of
the Hudson near Albany; again, where rivers meet the sea, they are
interrupted in their course by the rise of the tides of the ocean, and
here again deposits take place, sometimes forming shoals and banks in
the ocean itself; at other times, bars and obstructions at their own
mouths; and again, deltas of solid land, constantly encroaching upon the
sea. This action, which is continually going forward, is called
alluvial. The delta of greatest fame, and from which the others have
derived their generic name, is that of the Nile; this we have evidence,
almost historic, to prove to be wholly the gift of the river. And if it
no longer increase as rapidly as in former ages, the cause is obvious,
for the alluvion has been pushed so far forward as to meet a strong
current that sweeps along the African coast, and must carry off much of
the earth the Nile discharges into the Mediterranean. The great rivers
of Asia and of America carry still greater quantities of solid matter,
but we have not the same distant traditions to refer to for the amount
of the increase they have caused; still, however, we know that the mouth
of the Mississippi has been advanced into the Gulf of Mexico several
leagues since the settlement of Louisiana; and that islands of great
extent are frequently formed, in the course of a single year, by the
deposits of the Ganges.
We however find traces of aqueous action far more extensive and powerful
than those which are now taking place under our eyes by fluviatile
action. There is no part of the globe that has been examined, which does
not show that it has been subjected to the action of water, in floods
far more powerful than any we now are in the habit of seeing. Every
where, except in the case of rocky cliffs, and steep mountains, or where
we see obvious evidence of a recent elevation, we find the surface
strewn with the deposits of water: boulders of greater or less size,
beds of gravel, sand, and clay, form the present outer coating of the
greatest part of the land. These deposits were long confounded with the
alluvial, but have at length been proved, by incontrovertible evidence,
to be the results of an action, which if not contemporaneous, must have
been universal. We have seen an able attempt to show that this species
of deposit did not take place at one and the same period, but was merely
the general consequence of similar causes acting at different epochs.
Our impression, we must however confess to be, that the action was not
only co-extensive with the globe, but contemporaneous. It at any rate
exhibits proofs the most satisfactory, that the last great and
extensive change which our earth has undergone, was effected by the
agency of water, in a state of rapid and violent motion. Ascribing this
deposit to a single flood, it has been styled diluvial.
There are cases where alluvial deposits rest upon the diluvium, and from
the depth of these it has been attempted to calculate the time that has
elapsed since the former of these actions was resumed. The diluvium has
also been found in caverns lying upon an ancient stalagmite, and covered
again with a new formation of that modification of carbonate of lime.
The thickness of the latter deposit has also been made the basis of a
calculation, and although neither of these methods is to be considered
as approaching to an accuracy more perfect than some hundreds of years,
the two methods confirm each other in the general result, which is,
that, at a date not more remote than fifty or sixty centuries, there
must have taken place a total submersion of all the land, except,
perhaps, the tops of high mountains, did they then exist. We have in the
sacred volume, a record of such a catastrophe, the flood of Noah, and
from that time to the present, no convulsion, equally extensive in its
influence, has devastated the globe. Have not then the geologists who
have seen in these indications the convincing evidence of that
occurrence, been warranted in their inference, of the identity of an
event pointed out by undeniable physical evidence, with one recorded in
a history to which one of the most confirmed sceptics has recently
admitted the merit of truth?
The diluvial deposits are found not only in the lower grounds, but on
the tops and sides of lofty mountains; we have ourselves noted them
distinctly characterized at high elevations upon the Kaatskills; they
are found among the Alps at Valorsine, 6000 feet above the level of the
sea, and in another place at more than 7000 feet. The excavations made
in the extension of the city of New-York at Corlaer's Hook, have laid
open a vast mass of diluvium, and afforded means for studying it with
great facility. It in fact presented the appearance of a great cabinet
of specimens of primitive and transition rocks, and it was possible in
many cases to determine the very mountain whence the fragments had been
torn. The most remarkable boulder, for instance, of a weight of at least
an hundred tons, was distinctly recognisable as identical in every
respect with the granitic syenite of Schooley's mountain, distant at
least forty miles. Others had no known type nearer than Connecticut, in
the opposite direction, while the gneiss and mica slate of the island of
New-York, with their various embedded minerals, the serpentine and many
of the magnesian minerals of Hoboken, with sandstone and trap of the
Pallisadoc range, were distinctly recognisable. In this great
excavation, where a region of a mile square was wholly removed, to a
depth, in many places, of thirty feet, no animal remains, as far as can
be learnt, were detected; thus marking a most important difference
between these deposits and those of the Old continent. Such is the
remark of an intelligent geologist, whom we are proud to reckon as our
_collaborateur_, and to whom that branch of Natural History is under no
small obligations.
"Fragments of granite and other primitive rocks, cast here and
there upon stratified formations, and interpersed in
diluvium,[10] present a fact as certain as it is astonishing.
All the chains of Mount Jura, all the mountains that precede
the Alps, the hills and plains of Germany and Italy, are strewn
with blocks of granite, often of a great dimension, and always
of a composition as pure, and as perfect a crystallization, as
the granites of the higher Alps. The same phenomenon is
repeated in the plains of Russia, of Poland, of Prussia, of
Denmark, and of Sweden. From Holstein to Eastern Prussia,
diluvial[11]grounds, sand and clay, are covered with an immense
number of blocks of granite. Near the island of Usedom, several
points of granite rock rise from the bottom of the Baltic. We
see in like manner, Scania and Jutland so filled with these
fragments, that they construct of them enclosures, houses and
churches. In the Lymfiord, a gulf of Jutland, and at some
places on the western side of that peninsula, great points of
granite rise from the bottom of the waters. But what is still
more remarkable, is to see immense masses of granite lying on
the tops of Roeduburg and Osmond, which are more than 6000
feet in height, and are therefore among the highest mountains
in the North of Europe."
Beneath the diluvial deposit, we find beds and strata of substances of
different character, and which appear on a cursory view to be involved
in inextricable confusion. Long and careful examination has at length
been efficient in ascertaining that in this apparent disorder are to be
seen the traces of an order, as perfect as that of any other mechanism
of nature, and of a succession of changes by which the earth has been
finally fitted for the habitation of man. These strata have been finally
arranged into five distinct classes, differing in their characters and
position. These have been so fully described in a former article in this
Journal, by the distinguished associate whom we have already quoted,
that no more remains for us to say, than what is merely necessary to
keep up the connexion of our subject.
These stratified rocks or formations are remarkable for the regular
order in which they succeed and overlie each other, furnishing distinct
and indisputable evidence of their having been formed in succession. The
first set of strata, which are never covered by any of the others, and
hence are conceived to be of most recent formation, lie inclined at a
small angle to the horizon. In many cases they do not assume the
character of rocks, but although distinctly stratified, are often soft
and friable, presenting beds of marle and clay, and thick deposits of
sand. In some cases their appearance is so similar to diluvial or even
alluvial deposits, that they might be mistaken for them, were it not
for their more regular stratification. These are the tertiary formations
of the German school, the superior order of Coneybeare and Philips.
Issuing from beneath these, and forming in their turn a considerable
portion of the surface of the earth, rising occasionally into
considerable hills, are strata of less uniform and regular inclination,
forming basins and cavities in which the tertiary deposits are often
found to lie, curved to conform to the bottoms of these basins.
The third and fourth series issue in their turn from beneath the
preceding, as does the fifth from beneath the fourth. Each is marked in
succession, by a greater degree of confusion or distortion in the
stratification, until the last, which is apparently upheaved and thrown
about without any regularity, its strata being occasionally found in
positions almost vertical. Not only is the succession of the five
different orders of rocks constant, but so is that in which the several
rocks of each series overlie each other. This regularity of succession
is, however, subject to this law; namely, that rocks of particular
orders, or even the whole order itself, may be wanting in particular
districts; thus, tertiary formations may be directly upon the lower
order, and the second, third, and fourth, may not be present; or any one
of the higher orders may lie directly upon any one of those we have
stated to be inferior to it; but it has never been observed that the
arrangement itself has been inverted, or that a rock which is in one
place inferior, becomes, in its turn, superior in another.
The fifth, or inferior order, is uniformly found beneath one or all of
the others; and, we may infer, that it in fact underlies the whole
surface of the globe, forming not only the foundation of the solid land,
but the original bottom on which the present bed of the sea is
deposited. The rocks that compose this series are all highly crystalline
in their character, are mostly composed of substances wholly or nearly
insoluble in water, are wholly devoid of organic remains, and are in
fact such substances as might be supposed to have been formed by slow
cooling, from a state of igneous fusion. Is it then assuming too much to
infer, that they are in fact the crust which has been first formed upon
the surface of the earth, intensely heated by its own condensation,
under the action of the gravitating force, that, communicated to it by
the hand of the Creator, determined its figure, and still maintains its
equilibrium. We do not include in this class, as is usually done, the
crystalline rocks not stratified, as we conceive them to have been
formed in another manner, to which we shall hereafter refer. All the
four higher series of strata show, in the most evident manner, that
their formation has been due to the action of water; the grauwacke is,
perhaps, the only rock that exists among them, in which the question
could, even on simple inspection of specimens, appear doubtful; but this
rock lies at the base of the old red sandstone, and upon the limestone
of the submedial order, or transition, as it is styled by the
Wernerians, and is equally regular in its stratification with either; we
cannot, therefore, admit any other cause of its formation than what is
common to them.
Some of these strata are obviously mechanical, others chemical deposits;
thus, the sandstones and conglomerates are certainly the products of the
disintegration of older rocks by a violent abrasion of running water,
and have settled when the currents have ceased to flow; all calcareous
rocks, except the limestones of the inferior or fifth order, the
primitive of Werner, on the other hand, appear to have been products of
chemical precipitation; while there are a few cases, as in the beds of
rock salt, where the deposit must have been due to evaporation.
Of all these rocks and formations, the primitive, as has already been
stated, and the sandstones, are wholly devoid of organic remains. And
even the last rule is to be received as not wholly free from exception;
for vegetable impressions have been found, as we are credibly informed,
in sandstone, at Nyack on the Hudson, and near Belleville in New-Jersey,
besides some other similar cases we shall hereafter note. All the other
strata present a greater or less abundance of the traces of the organic
kingdoms, from the slate, which lies lowest of the fourth order, to the
most recent beds of the tertiary, and to so much of the diluvium as has
been examined in the old continent. And although in the isolated case of
the diluvium at New-York, no fossil remains have been found, we are yet
unprepared to admit this as more than an exception, and are inclined to
think that the remains of the mastodon, for instance, must be diluvian,
or pre-diluvian. In this opinion, however, we know that we are opposed
by high authority, and therefore do not express it without hesitation.
"Organized fossil remains belong to three different classes:
the remains that have preserved their natural state, at least
in part; petrifactions; and impressions.
"The remains of the first class are principally bones, and even
entire skeletons, which, after having been stripped of the skin
and flesh that covered them, have remained, some buried in the
earth, others hidden in deep caverns. They are, sometimes,
calcined in whole or in part, without having lost their
configuration; they at others preserve, not only their texture,
but even some traces of their hair and skin. They are also
occasionally seen covered with a calcareous crust.
"Petrifactions, to use this word in its familiar sense, include
all stony bodies that have the figure of an organized body.
There are cases in which a strong solution has penetrated into
a cavity formed by an organic body that has disappeared. Then
the strong substance has occupied the cavity that has been left
empty, and has taken the external form of the body that
formerly existed there. If this body were, for instance, a
branch or trunk of a tree, the stone will have at its surface
its knots and asperities; but within, it will present all the
characters of a true stone; it will be no more, to use the
language of Hauy, than the statue of the substance that it has
replaced.
"At other times, a vegetable or animal substance, while
undergoing decomposition in a successive manner, and by obvious
degrees, is pressed by the petrifying liquid that already
surrounds it. As soon as an organic particle has disappeared,
its place is occupied by one of stone."
* * * * *
"Metallized bodies, and those which have been changed into
bitumen or carbon, belong to this system of formation; thus,
the turquoises, for instance, are the teeth of a great marine
animal; a metallic substance has penetrated them, and has
gradually replaced the softer parts of the bones.
"Impressions are often found between the plates of slaty rocks;
they are relievos or intaglios representing the skeletons of
animals, particularly fish, leaves, seeds, and entire plants,
of which the most common kind belong to the forus."
The impressions of vegetables are most abundant in the shales that
accompany coal formations; those of leaves and branches are the most
common, but there are a few instances in which they retain the delicate
structure of the flowers. All analogy leads to the inference, that those
now found in temperate climates, are of such a character as could only
exist in tropical regions; and when, as in some of the newer formations,
the species are identical with those which now exist, the living type is
only found within the torrid zone. A still more curious fact, is their
identity in similar formations in different parts of the world. At the
present day, the same soil in Pennsylvania and England produces plants
of very different characters, and those which are native to each are of
wholly distinct genera and species, while the fossils that accompany the
coal in the two countries are precisely similar. But even those brought
by Parry from the polar region of Melville island, are identical with
those of England, and of course with those of this distant part of the
same hemisphere in which the former are formed, although the character
of the climate is so diverse. At the epoch of the coal formation, there
existed plants, of genera, which, in temperate climates, at present
rarely rise to more than a few inches in height, and which were at that
remote period of enormous size. Thus, the forus must have attained the
height of from fifty to sixty feet. At present, the forus assume the
size of a tree only in the very warmest climates, and even there, are
far inferior in magnitude to those of the coal formation. Now, it is
well known, that the large size of the living species is due to great
and constant heat, and copious moisture. Hence we may fairly infer that
similar circumstances existed even at Melville island, where, at the
present time, for the greater part of the year, the thermometer is below
the freezing point.
As further instances of the same kind, we may quote the following facts.
Faujas St. Fond found, in a marly slate, covered by lava, in France, the
tree cotton, the liquid amber styrax, the cassia fistula, and other
plants of tropical regions. The same observer found the fruit of the
arcea palm near Cologne. The elastic bitumen of Derbyshire in England,
is identical with the caoutchouc, which now grows only in the warmer
parts of South America; and the amber of Prussia appears to be a fossil
gum, similar to the Copal.
Among the more recent in formation of fossil vegetables, are the
bituminized woods; these are often buried to great depths by diluvian
action, but are never found in perfect rock. The most remarkable
instance of this kind is at Bovey-Heathfield, in England, and beneath is
found the retinasphaltum, that seems to be no more than the expressed
viscorous juice of the trees. Coal is a similar formation, but due to a
more ancient period. The mines of Pennsylvania occasionally furnish
specimens, in which the fibre of the wood is as distinctly visible as in
recently prepared charcoal. However these vast beds may have been
formed, no doubt whatever can exist in respect to their vegetable
origin.
Among animal remains found in the fossil state, shells and zoophytes are
the most abundant. They form the principal parts of rocks which often
occupy considerable districts. They are most frequent in calcareous
strata, from the transition limestones to the highest of the marles. A
remarkable fact is observed in respect to these shells, and the other
fossils which accompany them; those which are found in the oldest, or
transition formations, are more different from those that now exist,
than those in the more modern deposits. Thus the transition limestones
and slates contain terrebratulites, with encrinites, pentacrinites, and
trilobites; in those of the submedial and medial series we find
belemnites and the cornu ammonis; many of which are extinct genera, and
some of which are of families that are no longer found living on our
globe, while even where the genus is now to be met with, the species at
least has become extinct; while in the latest of the tertiary or
superior formations, we find ostracites, pectinites, buccinites,
chamites, and many other genera that are still abundant, and even types
of living species.
By far the greater part of the animals whose remains are found in the
older strata are aquatic, and the vast extents over which they are
distributed, show, that the waters must at one time have covered a very
great proportion of what is now dry land. Nor has this change been
produced by any gradual subsidence, for we find no coincidence in the
levels of those portions of the land that contain similar fossils; some
for instance are still lower than the level of the present ocean;
others, again, of similar character, rest upon the tops or sides of the
highest mountains. In Europe, the tops of the highest of the Pyrenees,
rising 11000 feet above the level of the sea, are of limestone,
containing numerous fossil remains, while Humboldt found a rock,
similarly characterized, among the Andes, at the height of 14000 feet.
The ancient philosophers, who, in other departments of physical science,
were far behind the moderns, seem in this alone to have pursued a
process of inductive reasoning, which led to results far more accurate
than any attained by the moderns, until within a very few years. The
dogmatism which determined to find in every fossil aquatic remain a
proof of the particular Noachic deluge, and the timidity of those whose
researches had made them better informed, left the world wholly in the
dark as to the real inferences to be drawn from a study of the structure
of the earth; but what modern geologist could better express what are
now admitted opinions, than the words which the Roman poet puts in the
mouth of Pythagoras.
"Vidi ego, quod quondam fuerat solidissima tellus,
Esse Fretum. Vidi factas ex aequore terras:
Et procul a pelago conchae jacuere marinae;
Et vetus inventa est in montibus anchora summis.
Quodque fuit campus, vallem decursus aquarum
Fecit: et eluvie mons est deductus in aequor:
Eque paludosa siccis humus aret arenis;
Quaeque sitim tulerant, stagnata paludibus hument.
Hic fontes Natura novos emisit, at illie
Clausit: et antiquis concussa tremoribus orbis
Flumina prosiliunt; aut exaecata resident."
The order in which fossil remains are found to succeed each other in the
successive formations that are to be traced from the oldest rocks to the
diluvial deposit, are well illustrated in the words of a late
distinguished philosopher, whom we shall quote.
"In those strata which are deepest, and which must consequently
be supposed to be the earliest deposited, forms, even of
vegetable life, are rare; shells and vegetable remains are
found the next in order; the bones of fishes and oviparous
reptiles exist in the following class; the remains of birds,
with those of the same genera mentioned before, in the next
order; those of quadrupeds of extinct species in a still more
recent class; and it is only in the loose and slightly
consolidated strata of gravel and sand, and which are usually
called diluvial formations, that the remains of animals such as
now people the globe are found, with others of extinct species.
But in none of these formations, whether called secondary,
tertiary, or diluvial, have the remains of man, or any of his
works, been discovered: and whoever dwells upon this subject,
must be convinced that the present order of things, and the
comparatively recent existence of man as the master of the
globe, are as certain as the destruction of a former and
different order, and the extinction of a number of living
forms, which have types in being. In the oldest secondary
strata there are no remains of such animals as now belong to
the surface; and in the rocks which may be regarded as most
recently deposited, these remains occur but rarely, and with
abundance of distinct species;--there seems, as it were, a
gradual approach to the present system of things, and a
succession of destructions and creations preparatory to the
existence of man."
We have stated that the zoophytes and shell-fish have left the most
numerous fossil remains. Those of other families are not however rare.
Fish, for instance, are found in great abundance, near Glarus in
Switzerland, in clay slate; in Germany, at Papenheim, in a slaty marle,
in the cupriferous slate of Eisleben, in the fetid limestone of
Oehningen. They are also found in Egypt, and we have specimens of the
same sort from Lyria, in a limestone apparently belonging to the oolitic
or Jura formation. China and the coast of Coromandel have also fossils
of this sort, but by far the greatest quantity have been procured from
Mount Bolea, near Verona. A splendid suite from the last locality are to
be seen in the Gibbs' Cabinet at New-Haven. Besides the impressions of
entire fish, separate portions are very abundant, and perhaps the most
frequent of these are the teeth of sharks, which are sometimes of a
magnitude vastly greater than those of any living species. Animals of
the class of amphibia appear not to have existed until after the aera
that gave birth to fish. The oldest are probably the tortoises, of which
a specimen has been found in sandstone near Berlingen. They have also
been found in England, in the Netherlands near Brussels, at Aix in
Provence, and in the quarries near Paris. The most remarkable fossils of
this class belong, however, to the lizard family. Of these the most
remarkable are the plesiosaurus, the megalosaurus, the iguanodon, and
the crocodile of Maestricht, all belonging to extinct species.
The marine animals that are met with in a fossil state, are in great
part foreign to the climates in which they are found buried. It has been
shown that the fish of Bolea have their nearest living prototypes in the
seas of Otaheite. The perpites of Gothland have been supposed to be
petrifactions of the medusae of India. The madrepores, so abundant in
Russia and in the frozen deserts of Siberia, only live now in seas
within the tropics. Shells analogous to a great part of those found
fossil in England, are only to be seen in the Atlantic, in a living
state, on the coasts of Florida and Cuba. A shell-formed fossil at Havre
is only to be met with recent at Amboyna.
Of the shells found in Italy, fossil in the sub Appenine hills, many are
common to the Mediterranean and the Indian oceans. But while those in
the fossil slate and the recent specimens from the tropics correspond in
size, individuals of the same species from the Mediterranean are
dwarfish and degenerate.
Thus then the remains of aquatic and amphibious animals appear to
confirm the conclusion drawn from vegetable fossils, that a climate of
temperature as elevated as that now found in the tropics, once extended
into high northern latitudes. It has been seen that the fossil remains
and impressions of shells have been found at great heights upon the
sides, and even upon the tops of mountains; and that in the older of the
strata no trace is to be found of any but aquatic animals. Thus before
our existing mountains and the minerals they contain had arisen above
the general surface; before diluvial and alluvial deposits, or even the
great formations of sandstone and conglomerate had arisen from their
disintegration, the globe was covered, in a great degree, and as it
appears from considerations we have not space to enter into, by various
successive eruptions, with waters, sometimes fresh, sometimes saline.
These waters have, it could be readily made to appear, often rested long
on the surface in a quiet state, after having been in violent agitation;
and long ages of tranquillity have been succeeded and closed by
convulsions of the most violent character.
In all the regularly stratified formations, animals of the mammiferous
or cetaceous classes are wholly wanting; at least we have no proof that
can be relied upon of any having been found in formations which took
place prior to the last great deluge, that covered so much of the land
with diluvium. In this last formation, however, they are often found in
great abundance. Some of them are of recent, others of extinct species.
Among the most remarkable of the latter are, the palaeotherium, and
anoplotherium, found near Paris; the megalonyx, an animal of the sloth
genus, but of the size of an ox, found in Virginia; a still larger
sloth, called the megatherium, found near Buenos Ayres; the fossil
elephant, as different from the living elephants of India or Africa, as
the horse is from the ass, and which has been found in Europe, in Asia,
and in America. The mastodon, of which several species have been
discovered on the banks of the Hudson, in Kentucky, in Louisiana, in the
plains of Quito, in France, and finally on the borders of the Irrawaddy.
The bones of rhinoceroses, bears, elephants, and hyaenas, have been found
mixed in confusion in caverns; and it has been shown by Buckland that
the latter animal had inhabited these caverns, and drawn thither the
carcasses of the others as his prey, in one of the most perfect
inductive arguments which has been produced, since Bacon propounded the
rules of that species of reasoning.
"The moveable earths that fill the bottoms of valleys, and
which cover the surface of great plains, have furnished us in
the above two orders, of pachidermata and elephants, the bones
of twelve species, to wit: one rhinoceros, two hippopotami, two
tapirs, an elephant, and six mastodons. All these twelve
species are now absolutely extinct in the climates in which
their bones are found. The mastodons alone may be considered as
forming a separate genus, now unknown, but closely approaching
to the elephant. All the others belong to genera now existing
in the torrid zone. Three of these living genera are now found
only in the ancient continent, to wit: the rhinoceros, the
hippopotami, and the elephant; the fourth, that of the tapirs,
only exist in the new. The distribution of the fossil species
is different; the tapirs have been found only upon the old
continent, while elephants have been discovered in the new."
The fossil species, although belonging to known and existing _genera_,
are essentially different in _species_ from those which now live upon
the earth. The former are not mere varieties, but have marked specific
differences. This at least is beyond all doubt in respect to the
smaller of the hippopotami, and the gigantic tapir, as well as the
fossil rhinoceros, and is extremely probable in respect to the elephant
and the smaller tapir. If there be any question of the fact, it is only
in respect to the greater hippopotamus.
"These different bones are buried in all different places in
beds that resemble each other. They are often mixed
indiscriminately with those of other animals, identical with
those which exist at present. These beds are generally
moveable, sandy, or marly, and always within a short distance
of the surface. It is therefore probable that these bones have
been enveloped by the last catastrophe of the globe. In a great
number of places, they are accompanied by the accumulated
spoils of marine animals; in other places, but these are less
numerous, the remains of marine animals are not found, and
sometimes the sand or marle that covers them contains only
fresh-water shells. Although a small number of shells attached
to fossil bones indicate that, they have remained some time
under water, yet is there no authentic account of their having
been found covered with regular stony beds, filled with marine
remains, nor, in consequence, is there any proof of the sea
having made a long and peaceable stay above them.
"The catastrophe that has covered them, would appear then to
have been a great marine inundation, of no long duration, were
it not that they are found upon the tops of high mountains,
whither the waters of our present ocean could never have
reached in their most violent agitations. On the other hand,
these bones presenting no appearance of having been rolled,
being occasionally only fractured, as the remains of our
present domestic animals may occasionally be, and being
sometimes found in entire skeletons, and accumulated as if in a
common cemetery, demonstrate that the living beings to which
they have belonged, must have met their fate in the very parts
of the globe in which we now find the fossil monuments of their
existence."
All the animals of which we have particularly spoken, are of genera now
only found in the torrid zone, and the abundance of food which their
great size would have caused them to require, renders their existence in
numbers only possible in a warm climate. Their remains are, however,
found in almost polar regions, whence we obtain a third link in the
chain of evidence, that before the last great catastrophe to which the
globe was subjected, its surface must have been warmer than at present.
We have seen in a former place, that such a change of temperature may
have gradually occurred in consequence of a cooling of the external
surface of the globe by an excess of its radiation above the quantity of
heat received from the sun. The final cooling of its solid crust, down
to the mean temperature at which we now find it, might, as is obvious,
have been effected by a great irruption of waters, like that of which we
have distinct evidence in the diluvial deposits, and the animal remains
upon its surface. From that time, a state of equilibrium in the action
of solar and terrestrial radiation having been attained, while the mean
temperature still continues to depend upon the internal structure and
nature of the globe, the distribution of heat upon the surface, and the
vicissitudes of the seasons, have been solely influenced by the varying
relation between these two radiations, which if equal to each other in
their total amounts, differ in every different latitude, for every
successive day in the year, and during each varying hour of the day.
It has been attempted to explain this change that has unquestionably
taken place in the temperature of climate, by conceiving a change in the
situation of the earth's axis. This hypothesis, however, is shown to be
untenable by the calculations of physical astronomy: no other cause then
remains but an actual change in the condition of the earth itself.
The most remarkable of all the phenomena which the earth presents, are
the great changes of weight that have taken place in identical
formations which must have arisen from the prevalence of water, and
therefore nearly if not exactly upon the same level. The primitive or
lowest stratified rocks, probably had not water for their cause; still,
however, they must have been in the fluid state, and these are not only
found beneath all other rocks, and in the lowest places to which the
industry of man has penetrated, but they also rise and form the greatest
part in bulk of many of the highest mountains; indeed, if we except
volcanic mountains, of all the more elevated masses. The transition and
secondary formations are subject to similar although less changes of
level, rising, as has been seen, to the tops of the Pyrenees, and to
even a greater height on the sides of the Andes. The tertiary or
superior formations are found in Italy and Sicily, forming mountains
several thousand feet in height, while the latest of all, the diluvial
with its embedded mammalia, exists in the lofty table land of Quito. The
inference is irresistible, that we do not now find these deposits at the
levels where they were left by the ocean, as in the case of the
primitive rocks by their own crystallization from a fluid state, but
that they have been altered in their positions by actions of a character
totally distinct from that by which they were originally formed.
This inference is still further confirmed by the great and sudden
changes of level that are frequently to be seen in similar strata,
faults, as they are styled by miners, in which the same bed has its
level sometimes changed hundreds, nay even thousands of feet. These
faults, if in greatest abundance in the more ancient rocks, are to be
found even in the newest, and sometimes affect several formations
incumbent on each other, of ages the most different. Thus, then, we have
distinct and conclusive evidence, that as we inferred from theory, the
solid crust of the globe has been shattered and fractured repeatedly,
and at all the different epochs of its history. This fracturing and
cracking we have shown, must, in conformity with strict mechanical laws,
have been attended with the rise of the molten liquid from beneath,
which ought in some cases to have formed veins and dykes, in the places
where the fractures occurred. It is however possible, that the rise of
the fluid from beneath, may not have taken place where the pressure
occurred; but it would then have been compelled by hydrostatic pressure,
to issue at some other point, breaking and tearing the weaker parts of
the solid crust, in order to afford itself a vent.
The latter class of phenomena are still in action, and we have evident
traces of their occurrence in all the different stages of the world's
existence; of the former it will also be seen there is conclusive
evidence.
The visible effects of a subterranean heat, are most frequently met with
at the present day in the form of volcanoes. Of these, there are not
only a great number in activity, but there are still more that have been
certainly active since the last great change that the surface of the
earth has undergone.
That part of the great group of mountains which we have before
described, which lies in the new continent, contains many active
volcanoes, and others but recently extinct. Terra del Fuego, as its very
name imports, is the seat of many; Chili has several; in Peru are to be
noted Arequipa, Pichinca, and Cotapaxi; while Chimborazo is obviously
one that has become extinct at a period not remote. Passing the Isthmus
of Panama, we find the volcanoes of Guatimala and Nicaragua almost
infinite in number. In Mexico, are Orezaba, Popocatepetl, and Jorullo;
the last of which first rose from beneath the surface in 1759.
California has five active volcanoes; and we know, from the observations
of La Perouse and Cook, that they also exist along the north-western
coast of America. Mount St. Elias, in particular, was seen in a state of
eruption. These mountains connect those of Mexico with the volcanoes of
the Aleutian islands and of the peninsula of Alaska, which continue the
system towards Kamtschatka, in which peninsula there are three of great
violence. We have seen some proofs, that there are active volcanoes to
the north-west of China, but none now exist in Thibet; and the action
that once took place there has sought new vents, in regions more near to
the present bed of the ocean. Thus, Japan has eight volcanoes, Formosa
several, and, in proceeding to the south, the land of volcanic action
widens, and becomes of immense extent. It embraces the Philippine,
Marian, and Molucca islands, Java, Sumatra, Queen Charlotte's islands,
and the New-Hebrides. The active volcanoes of Europe and western Asia
are few in number; but those that are extinct form a great system, in
which the active ones are included, and which seems to spread in the
form of a belt, from the Caspian sea to the Atlantic. Volcanic action
still occurs on the shores of the Caspian. In the chain of Elburg is a
lofty mountain that still emits smoke, and around whose base are several
distinct craters. Syria and Palestine abound in volcanic appearances, of
which the great crater that has swallowed up the waters of the Jordan,
and forms the Dead sea, is the most remarkable. Greece and the Grecian
Archipelago have been, almost within historic times, the seat of a
volcanic action, of great extent and violence, and which has not wholly
exhausted itself. In Sicily, AEtna has burnt for 3300 years, and is yet
surrounded by extinct craters of more ancient date. The Lipari islands
are wholly volcanic. Vesuvius, that had long before intermitted its
eruptions, and broke forth again in the great one that destroyed
Herculaneum and Pompeii, is not the only volcanic mountain of Naples. An
extinct one of much greater size is to be found near Roccafina. The
catacombs of Rome are excavated in lava, and Tuscany contains strong
evidences of volcanic action. Volcanic indications can be traced near
Padua, Verona, and Vicenza, extending into Dalmatia. A district of
Hungary was suspected of containing the seeds of subterranean fire, and
the suspicion has been confirmed by an actual eruption. Germany and
Bohemia contain a great number of extinct volcanoes, as does the south
of France, and particularly Auvergne. In Spain, too, the proofs of a
volcanic agency are clear and decisive.
Greenland and Iceland present a third group of volcanoes; in the latter
island, a single volcano was in a state of continuous eruption for five
or six years. The Azores, the Canaries and Madeiras, also contain
numerous volcanoes, both active and extinct, as do the Caribbean
islands.
In comparing together volcanoes that are in present activity, and others
in which the crater and the streams of emitted lava are too distinct to
permit a doubt of their having arisen from the same cause, differences
are observed that only have arisen from great differences in the
circumstances under which the eruption has taken place. In many of the
ancient volcanoes, we find the emitted streams are arranged in prismatic
forms, constituting basalt, and frequently passing into what under other
circumstances would be styled _trap_ by the Wernerians. Now, we know
that when streams of lava enter the sea, they spontaneously assume the
prismatic structure. Hence we may infer, that these ancient volcanoes
originally gave vent to their craters beneath the level of the sea, at a
time when the rocks through which they penetrated, and over which their
streams have passed, were beds of the primitive ocean. The trap rocks
themselves may have been formed in a similar manner, by upward pressure
of the igneous fluid beneath, through the veins and fissures formed on
the breaking of the solid crust. Trap traverses, in dykes of unknown
depth, many formations, and is occasionally seen forming beds between
successive strata. It frequently occurs in faults, and sometimes in
extensive overlying masses. Close observation, and a just course of
analogy, lead to the irresistible conclusion, that all the trap rocks,
however situated or arranged, grow out of the same great cause, the
rising of the liquid interior of the earth to its surface. An action
sometimes taking place through veins and fissures in the solid crust,
and sometimes by the eruption of volcanoes, both occurring during the
pressure of water upon the surface. One of the most extensive groups of
trap-rocks is to be seen in the north-eastern part of the state of
New-Jersey. The Hudson is bordered for nearly forty miles by a great
ridge of columnar rock, lying upon sandstone. When this is surveyed with
an eye to its analogy to volcanic action, it appears as if it were the
outpourings of a crater, whose basin is now occupied by the lake in
which the Hackensack river takes its rise, and whence a great stream of
lava has run over the sandstone rock, as far as the strait that
separates Staten Island from the main land. The two Newark mountains are
ridges of the same description, of even greater extent; other smaller
ridges of the same kind are also distinctly visible, and the whole of
this last system appears to have proceeded from a crater now filled by
the alluvion of the Passaic, but which is bordered by a ridge still
occupying two-thirds of a circle, and showing conclusive marks of
igneous action, that goes by the name of the Hook mountain. The
phenomenon of a dyke of trap is well exhibited in the quarries near
Hartford in Connecticut, where this rock has been laid bare for a
considerable depth, as it rises through a sandstone rock, instead of
overlying it, as it is seen to do on the Hudson.
The trap-rocks, which are, generally speaking, of the character called
by mineralogists greenstone, vary in this district of New-Jersey, from a
compact basalt of homogeneous structure, to one of regular and distinct
crystallization, not distinguishable in hand specimens from primitive
syenite. A rock of this last character is to be found in the mountain
that extends from Morristown to Mount Kemble, which is columnar in its
structure, but almost identical, in mere external characters, with
stratified rocks of gneiss containing hornblende, that are found in the
primitive ridges within a few miles.
Thus then the older volcanic rocks gradually pass in character into
those which, under the general name of granitic, form the apparent
nucleus of gneiss and mica slate mountains, and penetrate them, and the
primitive limestones, in veins. One of the best instances of veins of
granite with which we are acquainted, are those which occur in the
quarries of white marble at Kingsbridge, which are traversed in every
direction by thin veins of a rock, principally composed of a white fetid
felspar, mixed with spangles of silvery mica, and small grains of
quartz, interspersed with occasional masses of tourmaline. The famous
locality of chrysoberyl, beryl, and other interesting minerals, at
Haddam, in Connecticut, is said to occur in a granitic vein passing
through strata of gneiss.
In all these cases we cannot fail to see evidence of igneous eruptions,
taking place, however, under circumstances widely different from those
of our present terrestrial volcanoes, or of the submarine craters of
more remote dates, but which can be readily explained by supposing,
either that the penetration took place when the surface of the earth was
so intensely heated as to admit of the injected veins being slowly
cooled, and therefore more perfectly crystallized; or that the issuing
mass was so great as to retain its heat for a great length of time.
It might at first sight appear difficult to explain how volcanic
energies should still continue in activity, now that the mean
temperature of the earth has become constant, and the outer crust can be
no longer subject to the shrinking, and consequent cracking which it
must have undergone while cooling. The phenomena that attend volcanic
eruptions furnish a full explanation of this, for they are attended in
almost all cases with the evolution of great quantities of gaseous
matters, and steam, which must therefore exist in a state of intense
compression, and at elevated temperatures, in the mass whence the
volcanic flood issues. Their elastic energies are sufficient to account
for all the striking effects that attend the action of volcanoes.
The earthquake is a phenomenon connected with volcanic eruptions, and
arising from the same great cause; but while the latter are confined to
certain mountains, and restricted within narrow limits at the present
day, an earthquake is sometimes found to prevail over a very large
portion of the earth's surface. To omit the more usual phenomena of
earthquakes, we shall speak of but one, which has in some cases been
observed, that throws a great light upon the manner in which the
stratified rocks have had their levels changed, and been dislocated and
distorted in the manner we now find them. We allude to the sudden
raising of countries of greater or less extent. Of this we shall quote
three several instances from a paper of Arago's.
"During the night of the 28th September 1759, a district of
three or four square miles, situated in the Intendency of
Valladolid, in Mexico, was raised up, like an inflated bladder.
The limits where the elevation ceased may still be determined
at the present day, by the fracture of the strata. At these
limits the elevation of the ground above its primitive level,
or that of the surrounding plain, is no more than thirty-seven
feet; but towards the centre of the lifted district, the total
elevation is not less than five hundred feet.
"This phenomenon had been preceded by earthquakes that lasted
nearly two months; but when the catastrophe occurred, all
seemed tranquil; it was announced only by a horrible
subterranean noise, that took place at the moment when the
ground was lifted. Thousands of little cones, of from six to
ten feet in height, called by the natives ovens, arose in every
direction; finally six great projections were suddenly formed
along a great crevice lying in a north-east and south-west
direction, all of which were elevated from 1200 to 1600 feet
above the adjacent plains. The greatest of these small
mountains has become a true volcano, that of _Jorullo_, and
vomits forth lava.
"It will be seen that the most evident and well characterized
volcanic phenomena accompanied the catastrophe of Jorullo; that
they were perhaps its cause; but this did not prevent an
extensive plain, old and well consolidated, upon which the
sugar-cane and indigo were cultivated, from being, in our own
days, suddenly raised far above its primitive level. The escape
of inflamed matter, the formation of the ovens and of the
volcano of Jorullo, far from having contributed to produce this
effect, must on the contrary have lessened it; for all these
openings must have acted like safety valves, and permitted the
elevating cause to have dissipated itself, whether it were a
gas or a vapour. If the ground had opposed a greater
resistance; if it had not given way in so many points, the
plain of Jorullo, instead of becoming a simple hill five
hundred feet in height, might have acquired the relief of the
neighbouring summits of the Cordilleras.
"The circumstances that attended the formation of a new island
near Santorin, in the Greek Archipelago, seem to me also well
fitted to prove that subterranean fires not only contribute to
elevate mountains by the aid of ejections furnished by the
craters of volcanoes, but that they also sometimes lift the
already consolidated crust of the globe.
"On the 18th and 22d May 1707, there were slight shocks of an
earthquake at Santorin.
"On the 23d, at sun-rise, there was seen between the great and
little Rameni (two small islands) an object that was taken for
the hull of a shipwrecked vessel. Some sailors proceeded to the
spot, and on their return reported, to the great surprise of
the whole population, that it was a rock that had risen from
the waves. In this spot the sea had formerly a depth of from
400 to 500 feet.
"On the 24th, many persons visited the new island, and
collected upon its surface large oysters that had not ceased to
adhere to the rock. The island was seen sensibly to increase in
size.
"From the 23d May until the 13th or 14th June, the island
gradually increased in extent and elevation, without agitation
and without noise. On the 13th June it might be about half a
mile in circuit, and from 20 to 25 feet in height. Neither
flame nor smoke had issued from it.
"From the first appearance of the island, the water near its
shores had been troubled; on the 15th June it became almost
boiling.
"On the 16th, seventeen or eighteen black rocks rose from the
sea between the new island and the little Rameni.
"On the 17th they had considerably increased in height.
"On the 18th smoke arose from them, and great subterranean
noises were heard for the first time.
"On the 19th all the black rocks had united and formed a
continuous island, totally distinct from the first; flames,
columns of ashes, and red-hot stones arose from it.
"The volcanic phenomena still continued on the 23d May 1708.
The black island, a year after its appearance, was five miles
in circuit, a mile in breadth, and more than 200 feet in
height.
"On the 19th November 1822, at a quarter past ten in the
evening, the cities of Valparaiso, Melipilla, Quillota, and
Casa Blanca, in Chili, were destroyed by a terrible earthquake
that lasted three minutes. The following day several observers
discovered that the coast, for an extent of thirty leagues, had
been visibly elevated, for upon a coast where the tide never
rises higher than five or six feet, any rise in the land is
easily detected.
"At Valparaiso, near the mouth of the Coucon, and to the north
of Quintero, rocks were seen in the sea, near the bank, that no
person had before perceived. A vessel that had been stranded on
the coast, and whose wreck had been visited by the curious, in
boats, at low water, was left, after the earthquake, perfectly
dry. In traversing the shore of the sea, for a considerable
distance near Quintero, Lord Cochran, and Mrs. Maria Graham,
found that the water, even at high tide, did not reach rocks,
on which oysters, muscles, and shells still adhered, the
animals inhabiting which, recently dead, were in a state of
putrefaction. Finally the whole banks of the lake of Quintero,
which communicates with the sea, had evidently mounted
considerably above the level of the water, and in this locality
the fact could not escape the least attentive observers.
"At Valparaiso the country appeared to be raised about three
feet, near Quintero about four. It has been pretended, that at
a distance of a mile inland, the rise had been more than six
feet; but I do not know the particulars of the measures that
led to this last inference.
"In this case there was no volcanic eruption, no lava poured
forth, no stones or ashes projected, into the atmosphere, and
unless it be maintained that the level of the ocean have
fallen, it must be admitted that the earthquake of 19th.
November 1822, has raised the whole of Chili. Now the last
consequence is inevitable, for a change of level in the ocean
would have manifested itself equally along the whole extent of
the coast of America, while nothing of the kind was observed in
the ports of Peru, such as Paytu and Callao.
"If this discussion had not already carried us so far, the
preceding observations, from which it results, that in a few
hours, and by the effect of a few shocks of an earthquake, an
immense extent of country rose above its former level, might
have been compared with those which show, that there exists in
Europe, a great country (Sweden and Norway) whose level is also
rising, but in a gradual manner, and by a cause that acts
unceasingly, but which cause is unknown."
Thus, then, to whatever portion of the earth's surface we turn our eyes,
we find the proofs of igneous action; our existing volcanoes, protruding
themselves through the newer stratified formations, and even the
diluvium, being in some cases more recent in their origin than the last
great catastrophe to which the earth has been subjected; those of more
ancient date forcing their way through the upper and lower secondary and
transition formations, which are also cut and intersected by dykes of
trap, while granite from the size of mountain masses down to their
veins, has upheaved and penetrated the oldest stratified rocks. We also
find great extents of country rising, sometimes gradually, sometimes
suddenly, above their former level.
Mountains, then, are not the nucleus on which our continents and islands
have been deposited, but are of subsequent origin, and have in their
rise elevated the land to such a height as to be no longer accessible to
the waters of the ocean. We may, even by examining through what strata
the mountains have been raised, or those which compose their sides and
crests when the elevating agent has not pierced through to the surface,
infer the geological age which gave them birth. A research of this sort
has been recently attempted and conducted with great ability by M. E. De
Beaumont.
We shall quote an abstract of his reasoning from the "_Annuaire,"_ for
1830, in the words of Arago, which will also serve to illustrate various
other points upon which we have touched.
"Among the formations of so many different kinds that form the
crust of our globe, there is a class which has been called
sedimentary (_terrains de sediment_). Those formations to which
this name is properly applied, are composed wholly, or in part,
of _detritus_, carried by water like the mud of our rivers, or
the sands of the beaches of the sea. These sands, in a state
of greater or less division, and agglutinated by siliceous or
calcareous cements, form the rocks called sandstones.
"Certain calcareous formations may also be reckoned in the same
class, even when they are wholly soluble, as is however rare,
in nitric acid; for the fragments of shells which they contain,
show, in another and perhaps better manner, that their
formation has also taken place in the bosom of the waters.
"Sedimentary formations are always composed of successive
layers, that are very distinctly marked. The more recent of
them may be arranged into four great divisions, which, in the
order of their antiquity, are
"The oolitic series or limestone of Jura;
"The system of greensand and chalk;
"The tertiary series; and finally
"The diluvian deposits.
"Although all these formations have been deposited by water,
and although they may all be found in the same locality lying
upon each other, the passage from the one to the other is never
made by insensible gradations. A sudden and marked change is
always to be perceived in the physical nature of the deposit,
and in that of the organized beings whose remains are found in
it. Thus it is evident, that between the epoch at which the
limestone of Jura was deposited, and that of the precipitation
of the system of greensand and chalk which covers it, there has
been upon the surface of the globe a complete change in the
state of things. The same may be said of the epoch that
separates the precipitation of the chalk from that of the
tertiary formations; as it is also evident that in every place
the state or nature of the liquid, whence the earths were
precipitated, must have changed completely between the time of
the formation of the tertiary strata, and that of the diluvium.
"These considerable variations, sudden, and not gradual, in the
nature of the successive deposits formed by the waters, are
considered by geologists as the effects of what they call '_The
Revolutions of the Globe_.' And even although it is very
difficult to say exactly in what these revolutions consisted,
their occurrence is not the less certain on that account.
"I have spoken of the chronological order in which these
different sedimentary strata have been deposited: I must
therefore state that this order has been determined by
following, without interruption, each different formation, to
those regions in which it could be ascertained beyond question,
and over a great horizontal space, that some particular layer
was above some other. Natural excavations, such as the cliffs
that border the sea, common wells, and Artesian fountains, with
the excavation of canals, have furnished powerful aid in this
inquiry.
"I have already remarked, that all these sedimentary formations
are stratified. In level countries, as might be expected, the
disposition of the layers is nearly horizontal. In approaching
mountainous countries, this horizontality, generally speaking,
ceases; finally, on the sides of mountains, some of these
layers are very much inclined; they even sometimes attain a
vertical direction.
"May not the inclined deposits that we see upon the slopes of
mountains, have been deposited in inclined or vertical
positions? Or is it not more natural to suppose, that they
originally formed horizontal beds, like the contemporaneous
beds of the same nature with which the plains are covered, and
that they have been lifted up and assumed new directions at the
moment of the elevation of the mountains on whose sides they
rest?
"As a general principle, it does not appear impossible that the
crests of mountains may have been incrusted _in place_, and in
their actual position, by sedimentary deposits, since we daily
see the vertical sides of vessels, in which waters charged with
sulphate of lime evaporate, covered with a saline crust, whose
thickness is continually augmented; but the question before us
does not present this general aspect, for it is merely required
to determine whether the _known_ sedimentary formations can
have been thus deposited. To this question we must reply in the
negative, as can be shown by two species of considerations,
wholly different from each other.
"Incontestable geological observations have shown, that the
calcareous layers which constitute the summits of Buet in
Savoy, and Mount Perden in the Pyrenees, elevated 11,000 or
12,000 feet above the level of the sea, have been formed at the
same time with the chalk of the cliffs that border the British
channel. If the mass of water whence these strata were
precipitated had risen 11,000 or 12,000 feet, the whole of
France would have been covered, and analogous deposits must
have existed upon all heights not exceeding 9,000 or 10,000
feet; now, it is found, on the contrary, that in the north of
France, where these deposits appear to have undergone little
change, the chalk never reaches a height of more than 600 feet
above the level of the present sea. They present precisely the
disposition of a deposit formed in a basin filled with a liquid
whose level has never reached any points that are at the
present day elevated more than 600 feet.
"I pass to the second proof, borrowed from Saussure, and which
appears even more convincing.
"Sedimentary formations often contain pebbles rounded by
attrition, and of a figure more or less elliptical. In the
places where the stratification is horizontal, the longer axes
of these pebbles are all horizontal, for the same reason that
an egg cannot stand upon its point. But where the strata are
inclined at an angle of 45 deg., the greater axes of many of these
pebbles form this same angle with the horizon; and when the
layers become vertical, the greater axes of many of the pebbles
become vertical also.
"This observation, in respect to the position of the axes of
the pebbles, _demonstrates,_ that the sedimentary formations
have not been deposited in the position they now occupy; they
have been raised in a greater or less degree, when the
mountains, whose sides they cover, have arisen from the bosom
of the earth.
"This being proved, it is evident that these sedimentary
formations, whose strata present themselves upon the slopes of
mountains, in inclined or vertical directions, existed before
these mountains arose. The formations of the same class that
are prolonged horizontally, until they meet the same slopes,
must be on the contrary of a date posterior to the formation of
the mountain; for it cannot be conceived, that, in rising from
the mass of the earth, it should not have elevated at the same
time all previously existing strata.
"Let us introduce proper names into the general and simple
theory which we have developed, and the discovery of M. de
Beaumont will be announced.
"Of the four species of sedimentary formations that we have
distinguished, three, and these are the uppermost, the nearest
to the surface of the globe, or the most modern, extend in
horizontal layers, from the Cote d'Or and from Forez, to the
mountains of Saxony; and only one, which is the oolite or
limestone of Jura, shows itself elevated within this district.
"Therefore the Hartz, the Cote d'Or, and Mount Pilus of Forez,
have risen from the globe since the formation of the Jura
oolite, and before the deposit of the three other formations.
"On the slopes of the Pyrenees and Appennines, two of the
formations are raised up, namely, the oolite and the greensand
and chalk; the tertiary formations, and the diluvium that
covers them, have preserved their primitive horizontality. The
Pyrenees and Appennines are, therefore, more modern than the
limestone of Jura, and the greensand which they have raised,
and more ancient than the tertiary strata and the diluvium.
"The western Alps, and among them Mount Blanc, have, like the
Pyrenees, raised the limestone of Jura, and the greensand, but,
in addition, they have also raised the tertiary formations; the
diluvium is alone horizontal in the vicinity of these
mountains.
"The date of the elevation of Mount Blanc must, therefore,
inevitably be placed between the epoch of the formation of the
tertiary strata and the diluvium.
"Finally, upon the sides of the central Alps, (Mount St.
Gothard,) and of the mountains of Ventorix and Liberon, near
Avignon, no one of the sedimentary formations is horizontal;
all the four have been raised up. When these mountains arose,
the diluvium itself must have already been deposited."
"The sedimentary formations appear, from their nature, and the
regular disposition of their layers, to have been deposited in
times of tranquillity. Each of these formations being
characterized by a particular system of organized beings, both
vegetable and animal, it is indispensable to suppose, that
between the epochs of tranquillity, corresponding to the
precipitation of two of these overlying formations, there must
have been a great physical revolution upon the globe. We now
know that these revolutions have consisted in, or at least been
characterized by, the raising of a system of mountains. The two
first liftings-up pointed out by M. de Beaumont, not being by
any means the greatest of the four he has succeeded in
classing, it will be seen that we cannot infer that the globe,
in growing older, becomes less fit to experience this species
of catastrophe, and that the present period of tranquillity may
not be terminated like those that have preceded it, by the
elevation of some immense mountain chain."
M. de Beaumont next attempted, by a fancied arrangement of zones and
parallels to great circles, to classify the mountains he had not an
opportunity of examining, with those in respect to which he had obtained
the above satisfactory conclusions. We fear, however, that he has
proceeded to theorize too speedily, and before he had obtained a
sufficient number of facts. We are certain, that in respect to the great
Alleghany group of the United States, which he classes with the Pyrenees
and Appennines, he must be mistaken, for no formations later than the
transition limestone are to be found in their vicinity. In respect to
the highlands of the state of New-York, and their branch of primitive
rocks, which extends along the Hudson to the island of New-York, the
sandstone of New-Jersey appears to continue horizontally until it
reaches their bases, and no rocks appear to have been raised on the
south-eastern side of the highlands, which are the easternmost of the
five parallel ridges of the Alleghanies, older than the slate; but on
their north-western side the transition limestone appears to have been
raised. They therefore are older than any mountains examined by M. de
Beaumont, and were we to hazard a conjecture, we should class them with
the Grampians of Scotland, and the mountains of Wales, in both of which
slate is the only rock of the transition series that appears to have
been elevated.
To complete our subject, it would be necessary that we should enter into
a discussion of the manner in which the ocean is now acting, by its
currents and tides, to distribute and deposit in its bed the sediment
which rivers and streams are constantly hurrying into it; and that we
should form some estimate, from what occurs within our reach, of the
effects produced in these deposits by the vast number of organized
beings that must people them, the deposits of vegetable matter, and the
exuviae, of animals. Such discussion would, however, be in a considerable
degree purely conjectural, and we therefore shall not enter into it. It
is sufficient to say, that formations analogous to those which the
elevation of the continents has exposed to our view, must be now taking
place in the bed of the ocean, whence they may be in their turn raised,
to task the ingenuity of future races of reasoning beings.
* * * * *
Inquiries into the history of the changes which our earth has undergone,
as they lead with infallible evidence to the proof of an existence of
this globe at a period almost infinitely more remote than that at which
man became its inhabitant, have been stigmatized as impious. The
intolerant theologian, adhering with pertinacity to his own system of
interpretation, fulminates anathemas against all who find in natural
appearances convincing evidence, that the earth was not suddenly and by
a single fiat called into existence in the exact, state in which we now
find it. Timid geologists have bent to the storm, and have endeavoured
to reconcile natural appearances with the arbitrary interpretations that
have been deduced from scripture. But neither is the inquiry itself less
holy than any of those which consider natural phenomena, exhibiting in
their progress convincing proofs of infinite wisdom and power in the
Creator, justifying the ways of God to man; nor is any one of the
results of the inquiry in the slightest degree opposed to the texts of
the sacred volume. The impiety rests with the interpreter, and not with
the physical inquirer. The former unwisely links to his spiritual belief
an interpretation at variance with natural appearances; and the latter,
if he do not inquire for himself, and believe on the evidence of the
former, that the truth or falsehood of the two distinct propositions are
inseparably connected, must, as he sees the one to be inconsistent,
hesitate with respect to the other. Some geologists, then, may have been
sceptics; but could the secrets of the heart be laid open, we cannot
help believing, that those who have most earnestly endeavoured to
reconcile the phenomena we know to exist, with the interpretation of
scripture, from which they appear to vary, have been at bottom the least
sincere in their religious faith.
For ourselves, we see no difficulties, no discrepancies between the
record of direct revelation, and the sublime passages of the book of
nature. We believe that "in the beginning God created the heavens and
the earth;" that he called at once into existence the whole material
world; but we also believe that he then impressed matter with laws,
under the action of which that material world must maintain its
existence, and secure its permanence, until the same almighty power
shall annihilate it. We are not of those who judge of the works of the
Deity from the conditions of the works which can alone be effected by
the power of man. However perfect or complete be human mechanism, it can
only move by the application of some power inherent in matter; did not
an elastic spring expand itself after being coiled, the chronometer
would be a dead and lifeless mass; did not fluids obey the force of
gravitation, and currents in the atmosphere the expansive power of heat,
the water-wheel and wind-mill would be useless; did not water form
vapour at elevated temperatures, and condense when cooled, the still
more powerful agency of steam would be wanting. Not only are machines of
no value unless impelled by natural agents, but they themselves are
subject to rapid decay, and require perpetual attention. Such is not the
case with the machinery of the universe; its motions are perpetually
varying, but yet in their variations invariable; continually oscillating
on each side of mean rates, yet never losing or gaining in intensity.
Such too is the case on the surface of our globe; the seasons
alternately clothe the forests with verdure, and strip them of their
leaves; seed time and harvest recur with invariable precision; the whole
of existing vegetables perish, and animals die and decay, yet the race
is perpetuated. Shall we set bounds to the exertion of almighty power,
and say, that races, that families, that species and genera, nay that
whole natural kingdoms may not in their turn decay and die, after
providing for the repeopling of the earth by new inhabitants? The
catastrophes of our planet are not yet at an end; the time will and must
come, as we may guess from natural appearances, and as we find predicted
in scripture, when the heavens shall be rolled up like a scroll, and the
earth shall melt with fervent heat; and in the new system of
appearances, the new heaven and earth shall succeed--the corruptible
bodies that are now sown in dishonour, shall be raised in honour and
incorruptible.
The present surface of our globe is to our limited views slowly
changing; to him who compares time with the immeasurable duration that
has preceded and must succeed our existence, it is rapidly hastening to
apparent ruin. The waters raised from the ocean, falling in greatest
abundance on the land, tear and wear away the surface, and deposit it in
the bed of the sea. Deltas form at the mouths of rivers by this action;
the basin of the ocean is gradually elevated, and, in addition, islands
and archipelagos are raised from its bed. The surface of the sea is for
the present lessening under the influence of these causes, but the time
must come, unless it be prevented by some catastrophe, when the ocean
must in its turn encroach upon the land, when the plains and valleys
shall become bays and gulfs, or even unite in continuous expanses of
water, and the greater mountains alone, diminished in bulk by continued
abrasion, shall stand as islands in the vast abyss. The earth would then
again be without form and void of inhabitants, as it was before the
creation of man. Such, however, will not be the termination of the
present order of things; we are taught to look for this in an igneous
eruption, the source of which now slumbers almost quiescent beneath our
feet.
Not only does revelation, but science, teach us that the earth must have
been covered with water, and void of animate life, previous to its
becoming the habitation of man. But they read their scriptures
differently from us who think that this state of things was the actual
beginning. There is no necessary connexion between the first verse of
Genesis and the succeeding. The beginning of the existence of matter,
and the state of vacuity and darkness whence the present order of things
emerged, may have been, so far as the text is concerned, and were, as we
know from appearances, separated from each other by unnumbered ages.
Neither is it necessary that we accept the literal meaning of the
passage, and conceive the Deity speaking with human voice, and calling
creation forth by audible fiat. The voice of the Deity is that unheard
and silent command which nature hears and obeys throughout all his
works. The pious and sincere believer sees an overruling providence
preserving him in kindness when it saves him from shipwreck, or
chastening him in mercy when it deprives him of friends or relations, as
distinctly as if he beheld the prince of the air stayed in his furious
course, or the angel of destruction taking his visible stand beside the
pillow of departing life. No miracles are necessary to him who sees in
the rising and setting of the sun, in the order and beauty of the
universe, in the absolute perfection of its mechanical laws, in his own
fearful and wonderful structure, the evidence of infinite wisdom in
design, and infinite power in execution; and the examination of the
structure and character of our globe, is as well calculated as any other
physical study to exhibit in full and brilliant light these attributes
of the Deity.