There is the same double wall of hills, now closely confining the valley, and again withdrawing from each other as though to flee into the desert. Everywhere are moving sheets of sand, steep black banks with their narrow strips of cultivation, villages which are scarcely visible on account of the lowness of their huts sycamore ceases at Gebel-Barkal, date-palms become fewer and finally disappear. The Nile alone has not changed. And it was at Philse, so it is at Berber. Here, however, on the right bank, 600 leagues from the sea, is its first affluent, the Takazze, which intermittently brings to it the waters of Northern Ethiopia. At Khartum, the single channel in which the river flowed divides; and two other streams are opened up in a southerly direction, each of them apparently equal in volume to the main stream. Which is the true Nile? Is it the Blue Nile, which seems to come down from the distant mountains? Or is it the White Nile, which has traversed the immense plains of equatorial Africa. The old Egyptians never knew. The river kept the secret of its source from them as obstinately as it withheld it from us until a few years ago. Vainly did their victorious armies follow the Nile for months together as they pursued the tribes who dwelt upon its banks, only to find it as wide, as full, as irresistible in its progress as ever. It was a fresh-water sea, and sea--_iauma, ioma_--was the name by which they called it. The Egyptians therefore never sought its source. They imagined the whole universe to be a large box, nearly rectangular in form, whose greatest diameter was from south to north, and its least from east to west. The earth, with its alternate continents and seas, formed the bottom of the box; it was a narrow, oblong, and slightly concave floor, with Egypt in its centre. The sky stretched over it like an iron ceiling, flat according to some, vaulted according to others. Its earthward face was capriciously sprinkled with lamps hung from strong cables, and which, extinguished or unperceived by day, were lighted, or became visible to our eyes, at night. [Illustration: 022.jpg AN ATTEMPT TO REPRESENT THE EGYPTIAN UNIVERSE.2] 2 Section taken at Hermopolis. To the left, is the bark of the sun on the celestial river.