depressions on its surface, with other seeming irregularities of its appearance. The hills and valleys are by him supposed to be formed by their pressing upon the internal fluid, which sustains the external shell of earth, with greater or less weight: those parts of the earth which are heaviest sink the lowest into the fluid, and thus become valleys; those that are lightest rise higher upon the earth's surface, and are called mountains. Such was the face of nature before the deluge; the earth was then more fertile and populous than at present: the lives of men and animals were extended to ten times their present duration; and all these advantages arose from the superior heat of the central globe, which has ever since been cooling. To account for the deluge, he says, that a comet descending in the plane of the ecliptic towards its perihelion, on the first day of the deluge, passed just before the body of the earth. This comet, when it came below the moon, would raise a vast and strong tide, both in the seas that were on the surface, and in the abyss which was under the upper crust of the earth, in the same manner as the moon at present raises the tides in the ocean. That these tides would begin to rise and increase during the approach of the comet, and would be at their greatest height when the comet was at its least distance from the earth. By these tides, caused by the attraction of the comet, he supposes that the abyss would assume an elliptical figure, the surface of which being much larger than the former spherical one, the exterior crust of earth must conform itself to the same figure. But as the external crust was solid and compact, it must of necessity, by the violent force of the tide, be stretched and broken.* This comet, by passing close by the earth, involved it in its atmosphere * How was the ark preserved during this commotion? To preserve the ark without the immediate protection of Providence, it would be necessary that the flood of water should be perfectly calm, and free from storms and tempests; but if the waters were smooth, and underwent no violent agitation, how could shells and marine bodies be thrown upon the land on the tops of mountains, or be buried many feet deep in the earth? The calm sea, necessary for preserving the ark, could move none of the shells; and the rough sea, necessary for transporting the shells, would destroy the ark. and tail for a considerable time, and left a prodigious quantity of vapours on the earth's surface. These vapours, being very much rarefied after their primary fall, would be immediately drawn up into the air again, and afterwards descend in violent rains, and would be the cause of the forty days rain mentioned in Scrip ture. The rest of the water was forced upon the surface of the earth by the vast and prodigious pressure of the incumbent water derived from the comet's atmosphere, which sunk the outward crust of the earth into the abyss. By these means he supposes that there was water enough brought on the surface to cover the whole face of the earth, to the perpendicular height of three miles. And, to remove this body of water, he sup poses the wind dried up some, and forced the rest through the cracks and fissures of the earth into the abyss, whence great part of it had issued. 4. BUFFON'S THEORY. M. De Buffon begins his theory by attempting to prove that this world which we inhabit is nothing more than the ruins of a world. "The surface of this im mense globe," says he, "exhibits to our observation, heights, depths, plains, sea, marshes, rivers, caverns, gulfs, volcanoes; and on a cursory view, we can discover in the disposition of these objects neither order nor regularity. If we penetrate into the bowels of the earth, we find metals, minerals, stone, bitumens, sands, earths, waters, and matter of every kind, placed, as it were, by mere accident, and without any apparent design. Upon a nearer and more attentive inspection, we discover sunken mountains, caverns filled up, shattered rocks, whole countries swallowed up, new islands emerged from the ocean, heavy substances placed above light ones, hard bodies inclosed within soft bodies: in a word, we find matter in every form, dry and humid, warm and cold, solid and brittle, blended in a chaos of confusion, which can be compared to nothing but a heap of rubbish, or the ruins of a world." In examining the bottom of the sea, he observes, "that we perceive it to be equally irregular as the surface of the dry land. We discover hills and valleys, plains and hollows, rocks and earths of every kind; we discover, likewise, that islands are nothing but the summits of vast mountains, whose foundations are buried in the ocean. We find other mountains, whose tops are nearly on a level with the surface of the water; and rapid currents which run contrary to the general movement; these, like rivers, never exceed their natural limits. The bottom of the ocean and shelving sides of rocks produce plentiful crops of plants of many different species: its soil is composed of sand, gravel, rocks, and shells; in some places it is fine clay, in others a compact earth; and, in general, the bottom of the sea has an exact resemblance to the dry land which we inhabit." In short, Buffon supposed that the dry land was formerly the bottom of the sea; he says, moreover, that it is impossible that the shells and marine substances which we find at an immense depth in the earth, and even in rocks and marble, should have been the effects of the deluge: for the waters could not overturn, and dissolve the whole surface of the earth, to the greatest depths. The earth must therefore have been originally much softer than it now is, and that it has acquired its present solidity by the continual action of gravity; and, consequently, the earth is much less subject to change now than formerly. With regard to the original formation of the earth and all the planets in our system, he supposes that they were detatched from the sun all at once by a mighty stroke of a comet ;* not in the form of globes, but in the form of torrents; the motion of the foremost particles being accelerated by those which immediately followed, and the attraction of the foremost particles would accelerate the motion of the hindmost; and that the acceleration produced by one or both of these causes, might be such as would necessarily change the original motion arising from the impulse of the comet; and a motion might result similar to that which takes place in the planets. The revolution of the primary planets on their axes, he accounts for from the obliquity of the original * Here Mr. Buffon loses himself in conjecture, scarcely within the verge of possibility, and very improbable, stroke impressed by the comet*" It is, therefore, evi- ' dent," says he, "that the earth assumed its figure when in a melted state; and to pursue our theory, it is natural to think, that the earth, when it issued from the sun, had no other form but that of a torrent of melted and inflamed matter: that this torrent, by the mutual attraction of its parts, took on a globular figure, which its diurnal motion changed into a spheroid: that when the earth cooled, the vapours which were expanded like the tail of a comet, gradually condensed, and fell down in the form of water upon the surface, depositing, at the same time, a slimy substance, mixed with sulphur and salts: part of which was carried by the motion of the waters into the perpendicular fissures of the strata, and produced metals; and the rest remained on the surface, and gave rise to the vegetable mould which abounds in different places, the organization of which is not obvious to our senses. "Thus, the interior parts of the globe were originally composed of vitrified matter. Above this vitrified matter were placed those bodies which the fire had reduced to the smallest particles, as sands, which are only portions of glass; and above these pumice-stones and the scoria of melted matter, which produced the different clays. The whole was covered with water to the depth of 500 or 600 feet, which originated from the condensation of vapours when the earth began to cool. This water deposited a stratum of mud, mixed with all those matters which are capable of being sublimed or exhaled by fire; and the air was formed of the most subtle vapours, which, from their levity, rose above the water. "Such was the condition of the earth when the tides, the winds, and the heat of the sun, began to introduce changes on its surface. The diurnal motion of the earth, and that of the tides, elevated the waters in the equatorial regions, and necessarily transported thither great quantities of slime, clay, and sand; and by thus elevating those parts of the earth, they perhaps sunk those *This is a wild theory to account for the diurnal motion of the earth and other planets! under the poles about two leagues, or a 230th part of the whole; for the waters would easily reduce into powder pumice-stones, and other spongy parts of the vitrified matter upon the surface; and, by this means, excavate some places and elevate others, which in time, would produce islands and continents, and all those inequalities on the surface, which are more considerable towards the equator than towards the poles." 5. DR. HUTTON'S THEORY. In the first volume of the Edinburgh Philosophical Transactions, Dr. Hutton has laid down a new theory of the earth: perhaps the most elaborate and comprehensive that has hitherto appeared. To give a general abstract of it would much exceed the bounds allotted to this chapter; wherefore, all that can be done here is, to point out some of the most striking passages. He says, the general view of the terrestrial system conveys to our minds a fabric erected in wisdom, and that it was originally formed by design as a habitation for living creatures. In taking a comprehensive view of the mechanism of the globe, we observe three principal parts of which it is composed; and which, by being properly adapted to one another, form it into a habitable world: these are the solid body of the earth, the waters of the ocean, and the atmosphere surrounding the whole.. On these Dr. Hutton observes: 1. The parts of the terrestrial globe more immediately exposed to our view, are supported by a central body, commonly supposed, but without any good reason, to be solid and inert. 2. The aqueous part, reduced to a spherical form by gravitation, has become oblate by the earth's centrifugal force. Its use is to receive the rivers, be a fountain of vapours, and to afford life to innumerable animals, as well as to be the source of growth and circulation to the organized bodies of the earth. 3. The irregular body of land, raised above the level of the sea, is by far the most interesting, as immediately necessary to the support of animal life. 4. The atmosphere surrounding the whole is evidently necessary for innumerable purposes of life and |