[538] Ireland.
[539] The equinoctial line.
[540] 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 obstinately rejected by the speculative geographers of Alexandria, because they imagined a certain uninhabitable zone, into which India ought not to penetrate.
[541] The truth of these facts depends on the locality where the observations are made. In the time of Alexander the most southern of the seven principal stars which compose the Greater Bear had a declination of about 61 degrees, so that for all latitudes above 29 degrees, the Wain never set. Consequently if Deimachus were speaking of the aspect of the heavens as seen from the northern provinces of India, the Punjaub for instance, there was truth in his assertion, that the two Bears were never seen to set there, nor the shadows to fall in contrary directions. On the other hand, as Megasthenes appears to be speaking of the south of India, that is, of the peninsula situated entirely south of the tropic, it is certain that he was right in saying that the shadows cast by the sun fell sometimes towards the north, at others towards the south, and that accordingly, as we proceeded towards the south, the Bears would be seen to set. The whole of Ursa Major at that time set at 29 degrees, and our present polar star at 13 degrees. β of the Lesser Bear was at that time the most northern of the seven principal stars of that constellation, and set at 8° 45′. So that both Bears entirely disappeared beneath the horizon of Cape Comorin.
[542] This would be at Syene under the tropic.
[543] Small zones parallel to the equator; they were placed at such a distance from each other, that there might be half an hour’s difference between each on the longest day of summer. So by taking an observation on the longest day, you could determine the clima and consequently the position of a place. This was equivalent to observing the elevation of the pole. At the end of this second book Strabo enters into a long description of the climata.
[544] This observation, taken at the time of Hipparchus, would indicate a latitude of 16° 48′ 34.”
[545] Nearchus in speaking of the southern extremity of India, near Cape Comorin, was correct in the assertion that in his time the two Bears were there seen to set.
[546] Hipparchus fixed the latitude of Meroe at 16° 51′ 25″, and the extremity of India at 18°. In the time of Alexander, the Lesser Bear was not observed to set for either of these latitudes. Strabo therefore drew the conclusion, that if Hipparchus had adopted the opinion of Nearchus, he would have fixed the extremity of India south of Meroe, instead of north of that city.
[547] Now ruins, near Jerobolos, or Jerabees, the ancient Europus; not Decr or Deir.