Hipparchus tries to invalidate this view of Eratosthenes, by sneering at the proofs on which it rests. Patrocles, he says, merits little credit, being contradicted by the two writers Deimachus and Megasthenes, who say that the distance486 taken from the southern ocean, is in some places 20,000, in others 30,000 stadia; that in this assertion they are supported by the ancient charts, and he considers it absurd to require us to put implicit faith in Patrocles alone, when there is so much testimony against him; or that the ancient charts should be corrected; but rather that they should be left as they are until we have something more certain on the subject.