The Name.—The early Egyptians called this river by a name which was probably pronounced Hap. It seems to be connected with a root meaning “concealed,” “mysterious.” This survived as a religious designation down to the fall of paganism. The “great river” was also a frequent name for the main stream, and this became the usual name of the Nile in late times as Ier-‘o and continued in use amongst the Copts. In the Bible the Nile is regularly named Yeōr (יאר ,יאױ), from the contemporary Egyptian Yor, “river.” The origin of the Greek and Roman name Νεῖλος, Nilus, is quite unknown. Αἴγυπτος in the Odyssey is the name of the Nile (masc.) as well as of the country (fem.) The Arabs preserved the classical name of the Nile in the proper name En-Nīl النيل‎, or Nil-Misr مصر‎ لنيل‎, the Nile of Misr (Egypt). The same word signifies indigo.^[1]

The modern Egyptians commonly call the river El-Bahr, “the sea,” a term also applied to the largest rivers, and the inundation “the Nile,” En-Nīl; and the modern Arabs call the river Bahr-en-Nīl, “the river Nile.”

Basin of the River.—The Nile system is a simple one with three principal divisions: (1) the main stream running south to north, and fed by the great lakes of East Central Africa; (2) the equatorial tributary rivers draining the country north-east of the Congo basin; (3) the Abyssinian affluents. The extent of the basin of the Nile is clearly indicated on the map. Its area is estimated at 1,107,227 sq. m., which compares with the 1,425,000 sq. m. area of the Congo basin. The smaller basin of the longer river is due to its narrowness when passing through the Sahara. Southward the basin includes the northern part of the plateau between the two “Rift” valleys which traverse that part of Africa, and also that portion of the Albertine (or western) “Rift” valley which lies north of the Mfumbiro mountains. That part of the plateau within the Nile basin is occupied by the Victoria Nyanza and its affluents. These affluents drain a comparatively small part of this plateau, which stretches south to Lake Nyasa. The most remote feeder of the Nile in this direction does not extend farther than 3° 20′ S. West and W.S.W. of Victoria Nyanza, however, the Nile basin reaches 3° 50′ S. (264 m. south of the equator) and 29° 15′ E., following the crest of the hills which dominate the north-eastern shores of Lake Tanganyika and the eastern shores of Lake Kivu. Turning north-westward from this point the Nile basin crosses the mountainous region of Mfumbiro and includes that of Ruwenzori. Its limit is marked by the western wall of the