facts, both of which he mentions: the first is, that the Black Sea receives nine or ten rivers, not one of which but supplies it with more than the Bosphorus throws out: and the second, that the Mediterranean does not receive more water from rivers than the Black Sea, although it is seven or eight times larger, and that what the Bosphorus supplies it with does not make the tenth part of what falls into the Black Sea; how then could this tenth part of what falls into a small sea have formed not only a larger sea, but have also so greatly increased the waters, as to have broken down the lands at the strait of Gibraltar, and overflow an island larger than the whole of Europe? It is easy to perceive that this passage of M. Tournefort has not had due reflection. The Mediterranean receives at least ten times more water from the ocean than from the Black Sea, because the Bosphorus is only 800 feet broad in its narrowest part, whereas the strait of Gibraltar is more than 5000, and that, even supposing their velocity to be equal, still the depth of the straits of Gibraltar is by far the greatest. M. de Tournefort, who ridicules Polybius on his predicting that the Bosphorus would be filled up in time, did not pay sufficient attention to circumstances, when he asserted that event to be impossible. This sea receives eight or ten great rivers, and as most of them bring sand and mud, must it not gradually be choaked up? Must not the winds and the natural current of the waters towards the Bosphorus, convey thither a part of these matters? It is, therefore, very probable that in a course of time the Bosphorus will be filled, when the waters of the rivers which come into the Black Sea shall be gradually diminished; now all rivers daily diminish, because the vapours collected by the mountains being the first sources of rivers, their quantity must decrease as the mountains diminish in height. The Black Sea in fact receives more water from rivers than the Mediterranean, and the same author observes, "the greatest rivers in Europe fall into the Black Sea, by means of the Danube, in which the rivers of Suabia, Franconia, Bavaria, Austria, Hungary, Moravia, Corinthia, Croatia, Bothnia, Servia, Transilvania, Wallachia, empty themselves; those of Black Russia and Podolia, go into the same sea by the Niester; those of the southern and eastern parts of Poland, of the northern parts of Muscovy, and the country of the Cossacks, enter therein by the Neiper or the Boristhenes; the Tanais and Copa also fall into the Black Sea by the Cimmerian Bosphorus; the rivers of Mingrelia, of which Phasis is the principal, also voids itself into the Black Sea, as does the Casalmac, the Sangaris, and other rivers of Asia Minor which have their course towards the north; nevertheless the Thracian Bosphorus, which is the only outlet from it, is not comparable to any of these great rivers."