CHAP. i. 38, 39. INTRODUCTION. 137 Caspian Gates to the embouchure of the Nile, passing by Thapsacus, your error will appear much greater. This is the sum of what may be alleged against Eratosthenes. 38. In another respect also we have to complain of Hip- parchus, because, as he had given a category of the state- ments of Eratosthenes, he ought to have corrected his mis- takes, in the same way that we have done ; but whenever he has any thing particular to remark, he tells us to follow the ancient charts, which, to say the least, need correction infi- nitely .more than the map of Eratosthenes. The argument which follows is equally objectionable, being founded on the consequences of a proposition which, as we have shown, is inadmissible, namely, that Babylon was not more than 1000 stadia east of Thapsacus ; when it was quite clear, from Eratosthenes' own words, that Babylon was above 2400 stadia east of that place ; since from Thap- sacus to the passage of the Euphrates where it was crossed by Alexander, the shortest route is 2400 stadia, and the Tigris and Euphrates, having encompassed Mesopotamia, flow towards the east, and afterwards take a southerly direc- tion and approach nearer to each other and to Babylon at the same time : nothing appears absurd in this statement of Eratosthenes. 39. The next objection of Hipparchus is likewise false. He attempts to prove that Eratosthenes, in his statement that the route from Thapsacus to the Caspian Gates is 10,000 stadia, gives this as the distance taken in a straight line ; such not being the case, as in that instance the distance would be much shorter. His mode of reasoning is after this fashion. He says, " According to Eratosthenes, the mouth of the Nile at Canopus, 1 and the Cyanea?, 2 are under the same meridian, which is distant from that of Thapsacus 6300 stadia. Now from the Cyaneas to Mount Caspius, which is situated close to the defile 3 leading from Colchis to the Cas- 1 Moadieh, the mouth of the river close to Aboukir. 2 Certain little islets at the mouth of the canal of Constantinople, in the Black Sea. These islands want about a degree and a quarter of being under the same meridian as Moadieh. 3 Gosselin remarks, that the defile intended by Strabo, was probably the valley of the river Kur, or the ancient Cyrus, in Georgia; and by Mount Caspius we are to understand the high mountains of Georgia,
