The same dial-plates[505] cannot be used in all places, the shadow of the sun being sensibly different at distances of 300, or at most of 500 stadia[506]. Hence the shadow of the dial-pin, which is termed the gnomon, at noon and at the summer solstice, in Egypt, is a little more than half the length of the gnomon itself. At the city of Rome it is only 1/9 less than the gnomon, at Ancona not more than 1/35 less, while in the part of Italy which is called Venetia, at the same hour, the shadow is equal to the length of the gnomon[507]. CHAP. 75. (73.)—WHEN AND WHERE THERE ARE NO SHADOWS. It is likewise said, that in the town of Syene, which is 5000 stadia south of Alexandria[508], there is no shadow at noon, on the day of the solstice; and that a well, which was sunk for the purpose of the experiment, is illuminated by the sun in every part. Hence it appears that the sun, in this place, is vertical, and Onesicritus informs us that this is the case, about the same time, in India, at the river Hypasis[509]. It is well known, that at Berenice, a city of the Troglodytæ, and 4820 stadia beyond that city, in the same country, at the town of Ptolemais, which was built on the Red Sea, when the elephant was first hunted, this same thing takes place for forty-five days before the solstice and for an equal length of time after it, and that during these ninety days the shadows are turned towards the south[510]. Again, at Meroë, an island in the Nile and the metropolis of the Æthiopians, which is 5000 stadia[511] from Syene, there are no shadows at two periods of the year, viz. when the sun is in the 18th degree of Taurus and in the 14th of Leo[512]. The Oretes, a people of India, have a mountain named Maleus[513], near which the shadows in summer fall towards the south and in winter towards the north. The seven stars of the Great Bear are visible there for fifteen nights only. In India also, in the celebrated sea-port Patale[514], the sun rises to the right hand and the shadows fall towards the south. While Alexander was staying there it was observed, that the seven northern stars were seen only during the early part of the night[515]. Onesicritus, one of his generals, informs us in his work, that in those places in India where there are no shadows, the seven stars are not visible[516]; these places, he says, are called “Ascia[517],” and the people there do not reckon the time by hours[518]. CHAP. 76. (74.)—-WHERE THIS TAKES PLACE TWICE IN THE YEAR AND WHERE THE SHADOWS FALL IN OPPOSITE DIRECTIONS. Eratosthenes informs us, that in the whole of Troglodytice, for twice forty-five days in the year, the shadows fall in the contrary direction[519]. CHAP. 77. (75.)—WHERE THE DAYS ARE THE LONGEST AND WHERE THE SHORTEST.