284 NORTH-EAST AFRICA. whilst at other points the sahel or tehama of the coast is occupied by the low hills of the tertiary epoch, moving sand-hills, and coraline reefs. The pyramid-shaped islet of Zemerjity which lies 60 miles off the coast in a line with the RlLs-Benas headland, serves as a landmark to the vessels entering the dangerous waters of the Arabian Sea. The Nubian Gold Mines. The Elba Mountains merge in the interior with other heights of divers forma- tions, in which the ancient Pharaohs worked gold and silver mines. It is certain that, during its long period of splendour, Egypt was very rich in precious metals ; in this respect the monuments are in harmony with the statements of the Greek authors. Nubia appears to have furnished the greater part of the gold, and accord- ing to a tradition, to which weight is added by the heaps of rubbish and galleries hewn in the auriferous rocks and formerly inhabited caves, the principal mining centre was at Wady-Alluki, which is a series of ravines stretching away to the west of the Elba Mountains. Tliese ravines were worked till the middle of the twelfth century of the Christian era. The Pharaohs, Ptolemies, Greek emperors, and Arab caliphs were obliged to protect their colonies of miners against the attacks of the surrounding nomad peoples, successively termed Blemmyes, Bejas, and Bisharins ; but the difficulties of obtaining sufficient wood to light the mines or water for the miners were probably the greatest obstacle in the way of profitably working the mines. All the supplies from the springs of the district had been carefully husbanded, and along the ancient desert routes, above the springs, crosses sur- mounted by a circle are still to be seen, indicating the presence of water. The description given by Diodorus Siculus, as well as the appearance of the galleries, shows that the gold was not collected in the sands, but extracted from the rock itself by the crushing process. This method was extremely costly, and could not now be adopted unless the mines were extremely rich, like certain Californian " placers." But the first exploration, undertaken by Linant de Bellefonds for Mohammed Ali, followed by numerous visits made by various geologists, have proved that the ancient mines of Nubia are no longer sufficiently rich to be profitably worked. Hitherto no inscriptions or sculptures have been discovered in the mining region ; however, a column found at Kuban, on the right bank of the Nile between Korosko and Assuan, and the texts of the Egyptian temple of Radesieh, built on the riverain route to the mines of Akito, shed much light on the resources of the Pharaohs. Moreover, there is in the museum of Turin a fragment of an Egyptian map, which represents a mining station with its shafts, depots, galleries, reservoirs, and temple of Ammon. This precious document, the oldest of its kind, since it dates from the time of Ramses II., is disposed .in a way inversely to that of our maps, the east side, which is that of the Red Sea, being to the left of the sheet. It is as yet uncertain what mining district it is intended to represent.
