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" 2. The estuary cut off from the sea by alluvium at its mouth, would become progressively fresh by the influx of river streams, and change into a lake, on whose bottom, clay, vegetable remains, and freshwater shells would be deposited.

“ 3. But as the phenomenon of trap veins transpiercing one another proves that a series of submarine convulsions took place-at successive periods, a second eruption of basalt might inundate the lake for a season with a shallow body of seawater, introducing with it a colony of new inhabitants. By successive deposits of their exuviæ, along with calcareous matter and sand, the bottom would eventually rise above the tide level ; and the sea would thus be slowly shut out, as the flood-gate became more complete; the production of sea-shells would proportionally diminish, and cease entirely, as the sea withdrew, and the ground became once more, first a brackish marsh, and then a fresh-water lake. · Peu à peu cette production de coquilles diminue, et cesse tout-à-fait; la mer se retire, et le sol se couvre de lacs d'eau douce,' 13.* 4. Now were formed the solid deposits of marly limestone, as in the truvertino of Italy: now the gypseous waters let fall their precipitate of soft plaster, which gradually consolidated round the bones of the anoplotheira, paleotheird, birds, crocodiles, trionyr tortoises, palms, and other productions of the tropical climate which then obviously must have prevailed in the latitudes of London and Paris. The period of the deluge was now drawing nigh, and partial dislocations of the strata began to betoken that awful catastrophe. The ocean bed, once more upheaved by a submarine expansive force, caused its waters to surmount the embouchure of the Parisian basin, and-make it again an estuary of the sea. 915 5. Now the third marine formation of Brogniart, or second above the chalk, commenced, with its yellow clay marls, its sandstone and marine sands, its marl limestone and upper sea marls. These deposits, on reaching a certain height, necessarily became a barrier to the sea, reconverting the basin into a freshwater lake. -- } * 6. In this state it continued, till

, by successive depositions, and the drainage of the waters after the deluge, it was finally brought into the existing condition. 1 i. Thus the vicissitudes of the land and ocean, pourtrayed in the tertiary formations, harmonise perfectly with other terraqueous phenomena of the same geological period," The whole may be regarded as characteristic preludes of that storm which ere long destroyed the old world and its inhabitants." - The Third Book is called the Deluge. It contains a great

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variety of curious information, as we may infer from the following list of its Chapters :

Chap. I. Physical records of an universal deluge, which new-modelled the earth.-Chap. II. Causes of geological catastrophe, distributed into two sections, of volcanic action and basaltic eruption.. Chap. III. The constitution of the primeval world, and the revolutions which it underwent, deduced from geological phenomena on physical principles.Chap. IV. Elevation of submarine strata.-Chap. V. Phenomena of the deluge.-Chap. VI. Animal remains or ruins of the deluge.-Chap. VII, The present earth, and era of its emergence.

We regret that our limits will not permit us to give so many or such lengthened extracts from this portion of the work as we could wish. We must confine ourselves to an outline of his theory of the primeval climates ; presenting views which we believe to be equally new and striking.

“ From the evidence advanced in the preceding chapter it incontestably follows, that a vast magazine of fire and explosion lies immediately within the crust of our sphere, throughout its whole terraqueous zones.

“ The subject of the interior temperature of the globe has been lately investigated with all the resources of mathematical analysis by M. Fourier.”

“ The preceding facts, and other similar ones, concur to show that the increase is nearly a degree of Fahrenheit for 65 feet. This increase will not be always of the same amount as at the present day: it will diminish progressively; but a great many ages must elapse before it be reduced to the half of its actual value. The extent of this diffusion of the central heat into the circumference, and of its waste into the celestial spaces, will therefore be proportional to its primitive intensity, and to the conducting quality of the investing materials.

“ If we apply heat to the flat bottom of a deep vessel, (of iron, copper, &c.,) which contains several alternate layers of sand, clay, and stony slabs, condensed as in the supermedial strata of England, and covered with water, we shall wait in vain for any distinct manifestation, at the top, of the subjacent fire: in fact, the lowest layer will become compacted by the heat into a schist impervious to liquids; so that the incumbent water will never arrive at the calorific source, and, severed by bad conducting matters, can never grow appreciably warm. In the great boilers of steam-engines, many results to this effect daily occur, which form sources of very serious annoy

ance Wherever the waters of supply are calcareous, more especially selenitic, they let fall a crust of gypsum on the bottom, which progressively thickens, so as to intercept a large portion of the subjacent heat, and by separating the iron from the water, allows the metal to become ignited, and to burn away. Such a deposit has been known to grow several inches thick, with a stony hardness; and, till laboriously chiselled off, it has rendered the vessel quite inoperative for raising a due supply of steam.

“We have merely to compare these incontestable results of art to the kindred phenomena of nature, to recognise not merely the analogy, but identity of operation in the two cases; for difference of magnitude constitutes no disparity of essence.

" In the early epochas of the antediluvian world, soon after the granitic atlas had uplifted the primitive mountains, and before the extensive series of mineral beds, which occupy our second book, were deposited beneath the ocean, its waters resting on the nearly concentric, or slightly broken zones of gneiss and mica slate, necessarily lay in closer proximity with the interior fires than at any subsequent period. Hence two important consequences: 1. From the thinness of the solid crust, the smallest chink or fissure in it would be an immediate focus of submarine explosion, accompanied and followed by a commensurate comminution and dispersion of the solid rocks and organic deposits through the agitated waters. 2. The ocean would then attain its maximum temperature; a pitch certainly far higher than at present, yet not incompatible with the vital functions of fish, many of which, according to Humboldt, can live in water almost boiling hot. Desfontaines found the sparus thriving in tepid fountains of 100° Fahr. near the town of Cassa in the kingdom of Tunis. ." From the extreme mobility of its molecules, water is the most expeditious conveyer of heat from below upwards; while, from its non-conducting quality, it is a most faithful carrier, losing none of it during its ascent. Hence any degree of warmth, however gentle, imparted to the bottom of the oceanic mass, will be transmitted unimpaired to the surface. And again, as water possesses a very high specific heat, one four times greater than air by weight, so that five gallons of water in cooling only one degree F., can warm by the same quantity 2650 cubic feet of air, being the contents of a chamber about 16 feet square, and 101 feet high ; we see what a' genial climate would be created over the earth from pole to pole, under such an order of things. ' Then the intrinsic source of terrestrial heat, having its diffusive energy but slightly ob

polut toshi structed, would be paramount over the solar; so that the position of the sun, relative to the equator, would act # very subordinate part in modifying climate, instead of being its sovereign arbiter, as at the present day. Plants which love a warm but humid atmosphere, like the equisetums, ferns, &c., would multiply and flourish, under such circumstances, with nearly equat vigour in the Arctic regions as under the Line! Hence 'also the difference of equatorial and polar temperatures would be at first comparatively small, so that a considerable uniformity of vegetation would pervade the most distant zones: We need not, therefore, be surprised at finding the same Cala; mites or gigantic equisetums buried among the coal-measures of New Holland, (near Port Jackson,) and of England; though now-a-days, that plants are subjugated to the undivided empire of the sun, they differ in species with very moderate variations of latitude, and with every change of hemisphere. ;)"

-" The first age of the world then, extending probably through several centuries, fully realized the universal and unfading spring of the poets. Under such fostering powers of vegetation, the coal-measure plants were matured; in countless myriads, with a rapidity to which modern experience can fure nish no parallel. Bụt the tremendous catastrophes of the crust of the earth, that took place soon after this period, of which the dislocations and disruptions of the coal-strata thema selves exhibit magnificent memorials, generated a vast quantity of detritus from the older rocks, which at first diffused through a turbid ocean, progressively subsided on its bottom in the chemical order of deposition; constituting beds of conglomerate' limestone, red marl, and lias; in variable proportions of thick noss and extent, according to the nature of the exploded and comminuted rocks. In the secondary formations of geology, in fact, we see nothing but a repetition of mineral triads, shells more or less fractured, covered with a two-fold coat, the undermost of sand or sandstone, the uppermost of clay more or less indurated. The tepid ocean-bed vied in fecundity with the glowing soil round its shores, and thus was covered with a thick deposit of shell-fish and their exuviæ. At each tencounter of the water and subjacent explosive metals, these shells would be more or less scattered and broken down, and when tranquillity returned, covered with their siliceous and argillaceous mantles.wi :10pt TVOT -11,9 9.1 l,

- The conglomerate limestone and red marl are referred by geologists (see Conybeare and Phillips) to the detritus of the primitive and transition rocks ; deposits just posterior to the coal formation. It is probable that the submarine disturbances Dui reci mi si sunt intiin oil git (19111 21100T

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Ure's New System of Geology.

129 at, 16:lt od; vloeg "}/0 TL x bloom! of that particular age were unfavourable to the multiplication of mollusca, But a period of repose seems to have followed, in which the shells of the lias were elaborated. These, with a little alumina, are condensed into the lithographic stone, and buried under a loamy compound of sand and clay. We have next the inferior oolite; merely a congeries of pulverised, shells, roofed with the corn-brash, &c., and overlaid with the Oxford clay. Then we come to the coral rag, teeming with vestiges of vitality; inhumed also beneath its sheet of Kimmeridge clay.

When we arrive at the Portland strata, we must consider that a series of most imperfect conductors of caloric, fully half a mile in thickness, had been by this time interposed between the bottom waters of the sea, and the deeper primitive or tran-. sition crust, on which they originally reposed. Sta!

“ The climate of the earth should therefore indicate, about the Portland era, an abatement of the hypertropical temperature of the first age."

In addition to the results of the successive interpositions of non-conducting media, between the ocean and its subjacent fires, in lowering the surface temperature of the globe, we must take the following phenomena into account. By each series of explosive dislocations of the terrestrial crust, the area of the land standing out of the water would be abridged ; that of the sea would be amplified, with a proportionate diminution of its depth; or, in other words, the cooling surface would be augmented at the expense of the heating surface; while the ocean would come to repose, as we have seen, on a .cooler, bed, because more distant from the central heat of the earth. These propositions we shall endeavour to place in a clear and certain light by an ample induction of facts.

In a revolving terraqueous sphere, deviating from the equilibrium, form of rotation, by its elevated lands and deep ocean beds, at every considerable disruption and comminution of its surface, the gravitating powers will become effective on the shattered shell, and arrange its fragments, so as to make the crust approximate more nearly to the geometrical spheroid, The mountain and table-land inasses will thus be strewn gyer the concave bottom of the seas, and cause a new di

distribution: of the waters round the sphere; in which the area of the dry, land will be diminished proportionally to the extent and Juration of the disruptions, n't B7 ) jasp) PILO!

1 Supposing the earthquakes, and consequent commination of the shell, pot partial and successive, but universal and synchronous, then the whole crust of the earth having its cohesion JAN.-MARCH, 1829

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