bones are found: the tropics being, as is before obferved, the natural limits of habitation for the ele- phant. But if it be admitted that this obliquity has really decreafed, and we adopt the higheft rate of decreafe yet pretended, that is of one minute in a century, to transfer the northern tropic to the Arctic circle, would carry the exiftence of thefe fuppofed elephants 250,000 years back; a period far beyond our con- ception of the duration of animal bones left expofed to the open air, as thefe are in many inftances. Befides, though thefe regions would then be fuppofed within the tropics, yet their winters would have been too fevere for the fenfibility of the ele- phant. They would have had too but one day and one night in the year, a cir- cumftance to which we have no reafon to fuppofe the nature of the elephant fitted.
However, it has been demonftrated, that, if a variation of obliquity in the ecliptic takes place at all, it is vibratory, and never exceeds the limits of 9 degrees, which is not fufhcient to bring thefe bones within the tropics. One of thefe hypothefes, or fome other equally voluntary and inad- miffible to cautious philofophy, muft be adopted to fupport the opinion that thefe are the bones of the elephant. For my own part, I find it eafier to believe that an animal may have exifted, refembhng the elephant in his tufks, and general ana- tomy, while his nature was in other re- fpecSs extremely different. From the 30th degree of fouth latitude to the 30th of north, are nearly the limits which nature has fixed for the exiftence and multiplication of the elephant known to us. Pro- ceeding thence northwardly to 361de- grees, we enter thofe afligned to the mammoth. The further we advance north, the more their veftiges multiply as far as the earth has been explored in that diredlion; and it is as probable as otherwife, that this progreffion continues to the pole itfelf, if land extends fo far. The centre of the frozen zone then may be the achme of their vigour, as that of the torrid is of the elephant. Thus na- ture feems to have drav/n a belt of fepa- ration between thefe two tremendous ani- mals, whofe breadth indeed is not pre- cifely known^ though at prefent we may fuppofe it about 64- degrees of latitude; to have afligned to the