"M. de Jussieu thinks, that as the bed of the sea is continually rising, in consequence of the mud and sand which the rivers incessantly convey there, the sea, at first confined between natural dykes, surmounted them, and was dispersed over the land, and that the dykes were themselves undermined by the waters and overthrown therein. In the earliest time of the formation of the earth, when no one thing had taken a regular form, prodigious and sudden revolutions might then have been made, of which we no longer have examples, because the whole is now in such a permanent state, that the changes must be inconsiderable and by degrees. "By some of these great revolutions the East and West Indian seas may have been driven to Europe, and carried with them foreign plants floating on its waters, which they tore up in their road, and deposited gently in places where the water was but shallow and would soon evaporate." FOOTNOTES: [220:A] Anno 1720; page 5. [227:A] A kind of soft gravelly stone. [233:A] On this subject see Stenon, Ray, Woodward, and others. [234:A] See Shaw's Voyages, Vol. ii, pages 40 and 41. [237:A] See Shaw's Travels. [240:A] Thevenot, Vol. I, page 25. [240:B] Voyage of Paul Lucus, Vol. II, page 380. ARTICLE IX. ON THE INEQUALITIES OF THE SURFACE OF THE EARTH. The inequalities which are on the surface of the earth, and which might be regarded as an imperfection to its figure, are necessary to preserve vegetation and life on the terrestrial globe. To be assured of this, it is only requisite to conceive what the earth would be if it was even and regular. Instead of agreeable hills, from whence pure streams of waters flow, to support the verdure of the earth; instead of those rich and flourishing meadows, where plants and animals find agreeable subsistence; a dismal sea would cover the whole globe, and the earth, deprived of all its valuable qualities, would only remain an obscure and forsaken planet, at best only destined for the abode of fishes. But independent of moral considerations, which seldom form a proof in philosophy, there is a physical necessity why the earth must be irregular on its surface; for supposing it was perfectly regular in its origin, the motion of the waters, the subterraneous fires, the wind, and other external causes, would, in course of time, have necessarily produced irregularities similar to those now seen. The greatest inequalities next to the elevations of mountains, are the depths of the ocean; this depth is very different even at great distances from land; it is said there are parts above a league deep, but those are few, and the most general depths are from 60 to 150 fathoms. The gulphs bordering on the coasts are much less deep, and the straits are generally the most shallow.