NILE, the longest river of Africa, and second in length of all the rivers of the globe, draining a vast area in north-east Africa, from the East African lake plateau to the shores of the Mediter ranean. Although falling short of the length of the Mississippi Missouri (4,194 m. according to the estimate of General Tillo), the Nile is at the head of all rivers as regards the length of its basin, which extends through 35° of latitude or 2,45o m. in a direct line, with a waterway of about 4,000 m. The Nile proper, i.e., from the outlet at Victoria Nyanza to the sea, is 3,473 m. long.
The early Egyptians called this river by a name which was probably pronounced Hapy. This survived as a religious designa tion 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 Yeor (-hie, -it:), from the contemporary Egyptian Yor, "river." The origin of the Greek and Roman name NEI,Xos, Nilus, is quite unknown. Al:Pytnrros 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-Nil „},g:ii or Nil-Misr , the Nile of Misr (Egypt). The same word signifies indigo.
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-Nil; they also call the river Bahr-en-Nil, "the river Nile." Basin of the River.—The Nile system is a simple one with three principal divisions : 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 north of Khartoum. 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.W. and W.S.W. of Victoria Nyanza, however, the Nile basin reaches 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 moun tainous region of Mfumbiro and includes that of Ruwenzori. Its limit is marked by the western wall of the Albertine Rift valley, in which lie the Albert and Edward lakes. For a considerable distance the water-parting between the Congo and the Nile is close to the Albert Nyanza and to the Nile as it flows from that lake, but not far north of Wadelai (2° 46' N.) the hills recede and the Nile basin expands westward, over the wide area drained by the Bahr-el-Ghazal and its tributaries. In this region there is no well-marked watershed between the Congo and Nile systems, which interlace. Farther north the limit of the basin is marked by the hills of Darfur. Below that point the valley of the Nile ex tends but a mile or two from the river banks.
The south-eastern limits of the Nile basin extend nearly to the western escarpment of the eastern Rift valley—the dividing plateau being a narrow one. North of the equator a bend is made westward to Mt. Elgon, which on the north-east sends its water towards Lake Rudolf. From Mt. Elgon the Nile watershed is some distance to the west of that lake, while to its north a turn is made again, the watershed including a great part of the Abyssinian highlands. Beyond 15° N. it follows a line generally parallel to the west shore of the Red Sea, except where diverted to the west by the basin of the Khor Baraka.