Strabo Geography 2.1.5

[5] This argument, I think, is in many instances unfounded. Eratosthenes availed himself of the statements of many writers, although Hipparchus alleges he was solely led by Patrocles. Who then are the authors of the statement that the southern extremity of India is under the same parallel as Meroe; and who are they who estimate ¹ the distance from Meroe to the parallel passing through Athens? Or who, again, were those who asserted that the whole breadth occupied by the mountains ² was equal to the distance from Cilicia to Amisus? Or who made known that, travelling from Amisus, the course lay in a straight line due east through Colchis, the [sea of] Hyrcania, so on to Bactria, and beyond this to the eastern ocean, ³ the mountains being always on the right hand; and that this same line carried west in a straight line, traverses the Propontis and the Hellespont? These things Eratosthenes advances on the testimony of men who had been on the spot, and from the study of those numerous memoirs which he had for reference in that noble library ⁴ which Hipparchus himself acknowledges to be gigantic.