Nile

In the Bahr-el-Jebel occur the great accumulations of "sudd" (q.v.), closely packed masses of floating vegetation which obstruct and, if not removed, prevent navigation (see p. 455). The aspect of the river throughout the sudd region is monotonous and de pressing. On all sides stretch reaches of the reed known as um suf or mother of wool (Vossia procera), ambach, "bus" and papyrus. These grasses rise 15 to 20 ft. above the water, so as often to close the view like a thick hedge. The level of the flat expanse is broken only at intervals by areas of higher ground on which are mounds of earth erected by the white ants and covered with a clump of brushwood or trees ; the moisture in the air is excessive ; mos quitoes and other swamp flies swarm in myriads. Yet touches of beauty are not wanting; water lilies (Nymphaea stellata and the sacred lotus of Egypt, Nymphaea Lotus)—white, blue and crim son—often adorn the surface of the stream. Occasionally the rare and odd-looking whale-headed stork or Balaeniceps rex is met with among the reeds, and at night the scene is lit up by innumer able fire-flies.

The White Nile.

From the confluence with the Bahr-el Ghazal at Lake No, the main stream, which here takes the name of Bahr-el-Abiad, or White river, adopts the easterly course of the tributary stream. Forty miles below the point where the Bahr-el Zeraf reunites with the main branch, the Nile receives its first great eastern affluent—the Sobat (q.v.), whose head-streams rise in the mountains of south-west Abyssinia and the region north of Lake Rudolf. Just above the Sobat junction the Nile resumes its northern course. It passes through a great alluvial plain, stretching from the spurs of the Abyssinian highlands in the east, to the hilly districts of Kordofan in the west, and covered with high grass and scattered bush.

About 56 m. below the Sobat mouth, in 9° 55' N., lies (on the left bank) Kodok (known as Fashoda until 1904), an Egyptian town founded in 1867 on the site of Denab, the old "capital" of the Shilluks, and famous for the crisis between England and France in 1898 through its occupation by the French officer Marchand. For the next 27o m. the scenery takes on a very mo notonous appearance. The river flows in a wide channel bordered by a belt of forest on either bank. At Abu Zeid (about 13° 5' N.) for a distance of nearly 4 m. the river is extremely broad and shallow, being fordable at low water. Fifteen miles lower down, at Goz Abu Goma—which is the northern limit of the sudd vege tation—the river is divided into two channels by Abba Island, wooded, narrow and 28 m. long. On Abba Island lived, for some years before 1881, Mohammed Ahmed, the Mandi. The White

Nile with its volume of about 1,500 cu. metres per sec. in Oct., diminishing to about 55o cu. metres in May, is the main supplier of water to Egypt in the spring and early summer.

The Blue Nile.

Five hundred and twenty miles below the Sobat mouth and 1,652 m. from Ripon Falls, in 15° 37' N., the White Nile is joined,by its greatest eastern confluent the Bahr-el Azrak or Blue Nile. In the fork of the two rivers stands Khartoum, the capital of the Anglo-Egyptian Sudan, whilst on the western bank of the White Nile is Omdurman, the former Mandist capital. At Khartoum the water of the one river is of a greenish-grey colour, that of the other is clear and blue, except when in flood, when it gains a chocolate brown from the mineral matter in sus pension.. The Blue Nile, or Abai as it is called in Abyssinia, rises in the Gojam highlands in I I° N. and 37° E., and flowing north wards 7o m. enters Lake Tsana (q.v.) near its south-west corner, to issue again at the south-east end. The Abai and its tributaries drain a great part of the Abyssinian plateau. The complicated river system is best understood by a study of the map. The Abai itself on leaving Lake Tsana makes a great. semicircular sweep south-east to north-west, from the highlands of Ethiopia to the plains of Sennar. In this section of its course its swirling waters rush over a long series of cataracts and rapids, descending from a height of 5,770 ft. at the outlet to about 1,400 ft. at Fazokl or Famaka (I I° 17' N., 35° 1o' E.), where it crosses the Abyssinian frontier and flows through the plains of Sennar to its confluence with the White Nile at Khartoum, 1,300 ft. above sea-level.

Of the tributaries of the Abai the majority join it on its left bank. The Bashilo, Jamma and Muger, which reach the Abai in the order named, drain the cduntry east of the main stream be tween the basins of the Takazze and the Hawash. The Guder, with a south to north course, rises in the mountains which form the watershed between the Nile and the Lake Rudolf basin. Next comes the Didessa, a large stream rising near the head-waters of the Baro (the main upper branch of the Sobat) and flowing north west to the Abai, the confluence being in about N., 4o' E. It has an early rise and a long flood period, being by far the most important tributary of the Blue Nile. The Dabus or Yabus rises about N., 3o' E., and flowing north joins the Abai near the spot where that river breaks through the Abyssinian hills. All these affluents are perennial, as is the Bolassa or Yesien, a right hand tributary which reaches the Abai below the Yabus.