Book 2
1.39
To this we reply, that Eratosthenes, as is usual in Geography, speaks of right lines, meridians, and parallels to the equator, with considerable latitude, whereas Hipparchus criticizes him with geometrical nicety, as if every line had been measured with rule and compass. Hipparchus at the same time himself frequently deciding as to right lines and parallels, not by actual measurement, but mere conjecture. Such is the first error of this writer. A second is, that he never lays down the distances as Eratosthenes has given them, nor yet reasons on the data furnished by that writer, but from mere assumptions of his own coinage. Thus, where Eratosthenes states that the distance from the mouth of the [Thracian Bosphorus] to the Phasis is 8000 stadia, from thence to Dioscurias 600 stadia,Now Iskouriah. Dioscurias, however, is 800 stadia from the Phasis, of 700 to a degree. and from Dioscurias to Caspius five days’ journey, (which Hipparchus estimates at 1000 stadia,) the sum of these, as stated by Eratosthenes, would amount to 9600 stadia. This Hipparchus abridges in the following manner. From the Cyaneae to the Phasis are 5600 stadia, and from the Phasis to the Caspius 1000 more.According to our improved charts, the distance from the meridian of the Cyaneae to that of the Phasis is 6800 stadia, of 700 to a degree; from the Cyaneae to Mount Caspius, 8080. There fore it is no statement of Eratosthenes that the Caspius and Thapsacus are under the same meridian, but of Hipparchus himself. However, supposing Eratosthenes says so, does it follow that the distance from the Caspius to the Caspian Gates, and that from Thapsacus to the same point, are equal.The meridian of Mount Caspius is about 2625 stadia nearer the Caspian Gates than that of Thapsacus.
