876 NOETH-EAST AFEIOA. determined the dimensions of the planet. He did not take the direct measurement of the distance between Syene and Alexandria. But the Egj^tian people, who knew so well how to turn their edifices towards the rising sun, must have also known not only the distance, but also the exact position of these places. Hence the common estimate accepted by the Greek astronomer must have come very close to the truth. If the measurement of the meridian made by him was in Egyptian feet, as is probable, his calculation was wrong by scarcely a sixty-fifth. The real length of the arc of the meridian, between Alexandria and the parallel of Syene, is exactly 787,760 metres, while the measurement of Eratosthenes gave 810,000 metres.* Elephantine Island, which faces Assuan on the other side of a channel 500 feet wide, was also the site of a famous city. Here stood Abu, the " City of the Elephant," which afterwards, during the Greek and Roman periods, appears to have been the great emporium for the ivory brought down from the Upper Nile. But scarcely any of its ancient monuments have survived to the present day. Its temples were demolished in 1822, to supply building materials, and little is now to be seen except a Nilometer restored in 1870, and some heaps of ancient pottery on which the custom-house officers of the Roman epoch used to scratch their receipts. On the ruins now stand two villages of Barabra Nubians. But Elephantine, the
- ' Verdant " Isle of the Arabs, still possesses its magnificent date groves, whose
brilliant foliage presents a striking contrast to the black rocks commanding the issue of the cataract. Ombos — Edfu. The site of the ancient city of Ombos is now indicated only by the hamlet of Kom-Ombo, situated on the west bank, and by the ruins of two temples dedicated to two rival dieties, Horus, god of light, and Sebek, the genius of darkness. But the stream is continually eating away this bank, with its sanctuaries and the sand encimabering them. The defile of Silsikh, or the "chain," below Kom-Ombo, would be the most convenient point for constructing a barrage to raise the level of the river and divert a portion of the current to the irrigation canals. According to the proposed plan, the main channel would skirt the foot of the Libyan range, watering all the now barren tracts which stretch west of the Bahr-Yusef. But, as elsewhere pointed out, there are many serious objections to this scheme, which, if carried out, would probably have the effect of throwing out of cultivation some ifixtensive districts along both banks of the Nile. The Silsileh defile, formed of sandstone rocks, is one of the most remarkable Tp^aces in Egypt. On the east side the cliffs have been cut by the ancient quarry- men into avenues and cirques, affording an opportunity of admiring the rare skill with which they made choice of the finest-grained stone and the care with which they extracted it. In this respect the Silsileh quarries might still serve as models for our modem contractors. It might almost seem, remarks Mariette, as if the • Fayo, "Journal Officiel de la Rdpublique Francjaise," April 29, 1881.
