The incredible is before us. Beyond one of these gateways a broad green plain appears, a multitude of palms, the blue waters of a lake. Even sheep are seen pasturing, with cattle and horses. From afar, on the sides of a cliff, towers up a town; on the summit of the cliff are the white walls of a temple. That is an oasis, or island in the sand ocean. In the time of the pharaohs there were many such oases, perhaps some tens of them. They formed a chain of islands in the desert, along the western boundary of Egypt. They lay at a distance of ten, fifteen, or twenty geographic miles from the Nile, and varied in size from a few to a few tens of square kilometres in area. Celebrated by Arab poets, these oases were never really the forecourts of paradise. Their lakes are swamps for the greater part; from their underground sources flow waters which are warm, sometimes of evil odor, and disgustingly brackish; their vegetation could not compare with the Egyptian. Still, these lonely places seemed a miracle to wanderers in the desert, who found in them a little green for the eye, a trifle of coolness, dampness, and some dates also. The population of these islands in the sand ocean varied from a few hundred persons to numbers between ten and twenty thousand, according to area. These people were all adventurers or their descendants,--Europeans, Libyans, Ethiopians. To the desert fled people who had nothing to lose,--convicts from the quarries, criminals pursued by police, earth-tillers escaping from tribute, or laborers who left hard work for danger. The greater part of these fugitives died on the sand ocean. Some of them, after sufferings beyond description, were able to reach the oases, where they passed a wretched life, but a free one, and they were ready at all times to fall upon Egypt for the sake of an outlaw's recompense. Between the desert and the Mediterranean extended a very long, though not very wide strip of fruitful soil, inhabited by tribes which the Egyptians called Libyans. Some of these worked at land tilling, others at navigation and fishing; in each tribe, however, was a crowd of wild people, who preferred plunder, theft, and warfare to regular labor. That bandit population was perishing always between poverty and warlike adventure; but it was also recruited by an influx of Sicilians and Sardinians, who at that time were greater robbers and barbarians than were the native Libyans. Since Libya touched the western boundary of Lower Egypt, barbarians made frequent inroads on the territory of his holiness, and were terribly punished. Convinced at last that war with Libyans was resultless, the pharaohs, or, more accurately, the priesthood, decided on another system: real Libyan families were permitted to settle in the swamps of Lower Egypt, near the seacoast, while adventurers and bandits were enlisted in the army, and became splendid warriors.