14.

But, Eratosthenes would reply, I never said that, in consequence of the repletion of the Mediterranean, it actually flowed into the Erythræan Sea, but only that it approached very near thereto: besides, it does not follow, that in one and the self-same sea, the level of its surface must be all the same; to instance the Mediterranean itself, no one, surely, will say it is of the same height at Lechæum359 and at Cenchrea.360 This answer Hipparchus anticipated in his Critique; and being aware of the opinion of Eratosthenes, was justified in attacking his arguments. But he ought not to have taken it for granted, that when Eratosthenes said the exterior sea was all one, he necessarily implied that its level was every where the same.