Strabo Geography 2.1.12

[12] But the system of Hipparchus altogether teems with difficulties. Reflect for an instant on the following absurdity; after admitting that the southern extremity of India is under the same degree of latitude as Meroe, and that the distance from Meroe to the Strait of Byzantium is about 18,000 ¹ stadia, lie then makes the distance from the southern extremity of India to the mountains 30,000 stadia. Since Byzantium and Marseilles are under the same parallel of latitude, as Hipparchus tells us they are, on the authority of Pytheas, and since Byzantium and the Dnieper ² have also the same meridian, as Hipparchus equally assures us, if we take his assertion that there is a distance of 3700 ³ stadia between Byzantium and the Dnieper, there will of course be a like difference between the latitude of Marseilles and the Dnieper. This would make the latitude of the Dnieper identical with that of Keltica next the Ocean; for on proceeding 3700 stadia [north of Marseilles], we reach the ocean. ⁴