The formation of the earth affords a wide field for speculation; and, accordingly, many ingenious theories have been conceived to explain the various appearances which its surface exhibits. The best modern naturalists seem, however, to agree, that water has been one of the principal agents to produce these effects. The great Linnæus, whose penetrating mind pervaded the whole empire of nature, after many and laborious enquiries, acquiesced in the truth of the sacred writings, that the whole globe of the earth was, at some period of time, submerged in water, and covered with the vast ocean, until in the lapse of time one little island appeared in this immense sea, which island must have been of course the highest mountain upon the surface of the earth. In support of his hypothesis, he adduces a number of facts, many of which have fallen within his own observation, of the progressive retreat of the sea, the diminution of springs and rivers, and the necessary increment of land. Among the most remarkable of these are the observations made by the inhabitants of Northern Bothnia upon the rocks on the sea coast, from whence it appeared that, in the course of a century, the sea had subsided more than four feet; so that six thousand years ago, supposing the rate of retiring to have been the same, the sea was higher than at present by two hundred and forty feet. Such great and sensible depression of the water of the sea must, however, have been only local, otherwise, as I have elsewhere observed, the Red Sea and the Mediterranean would have joined within the period of history. The sea, it is true, in some parts of the world, gains upon the land, and in others the land upon the sea, but these effects arise from a different cause to that which is supposed to produce a general retreat. It is true, also, that in the neighbourhood of mountains and great rivers, very material changes have taken place in the course of a few ages. The fragments of the former, worn away by the alternate action of the sun and rains, are borne down by the torrents of the latter, and deposited in the eddies formed by the two banks of the rivers where they join the sea, producing thus alluvious land as, for example, the Delta of Egypt, which has gradually been deposited out of the soil of Abyssinia and Upper Egypt; the plains of the northern parts of China, which have been formed out of the mountains of Tartary; and those of India from the Thebetian mountains, and the other high lands to the northward and westward of the peninsula. As, however, a much greater proportion of the fragments borne down by rivers must be deposited in the bosom of the deep than on its shores, the sea by this constant and effective operation ought rather to advance than to retreat. We may therefore, perhaps, conclude that, whatever the changes may have been which the surface of the earth has undergone, with regard to the proportion and the portion of land and water, the appearances we now behold in various