CHAP. i. $ 19. INTRODUCTION. 117 stadia north of Marseilles, the day has 18 hours. Conse- quently [according to his hypothesis] the most southerly parts of Britain must be north of these regions. They must therefore be under the same parallel, or almost the same, as the parts of Bactriana next to the Caucasus, which I have shown are, ac- cording to the followers of Deimachus, 3800 stadia farther north than lerne. 1 Now if we add this to the number be- tween Marseilles and lerne, we shall get 12,500 stadia. But who ever made known to us that, in those parts, I mean, in the vicinity of Bactra, this was the duration of the longest day, or the height which the sun attains in the meridian at the winter solstice ? All these things are patent to the eyes of every man, and require no mathematical investigation ; there- fore they certainly would have been mentioned by numerous writers both amongst the ancients who have left us histories of Persia, and by the later writers too, who have carried them down to our own time. How, too, would their fertility, which I have described above, harmonize with such a lati- tude ? The facts here advanced are sufficient to give an idea of the learned manner in which Hipparchus attempts to controvert the reasoning of Eratosthenes by mere petitiones principii. 19. Again, Eratosthenes wished to show the ignorance of Deimachus, and his want of information concerning such mat- ters, as proved by his assertion that India lies between the autumnal equinox 2 and winter tropic. 3 Also in his blaming Megasthenes, where he says that in the southern parts of India the Greater and Lesser Bear are seen to set, and the shadows 1 Ireland. 2 The equinoctial line. 3 There is no doubt that the expressions which Deimachus appears to have used were correct. It seems that he wished to show that beyond the Indus the coasts of India, instead of running in a direction almost due east, as the Greeks imagined they did, sloped in a direction between the south and the north-east, which is correct enough. As Deimachus had resided at Palibothra, he had had an opportunity of obtaining more exact information relative to the form of India than that which was current at Alexandria. This seems the more certain, as Megasthenes, who had also lived at Palibothra, stated that by measuring India from the Caucasus to the southern extremity of the continent, you would obtain, not its length, as the Greeks imagined, but its breadth. These correct accounts were ob- stinately rejected by the speculative geographers of Alexandria, because they imagined a certain uninhabitable zone, into which India ought not to penetrate.
