ORANGE RIVER (Hottentot Gru•icp, Great Water). The principal river of the extreme southern part of Africa (\lap: Africa, F 7). Its farthest headstream rises on the slope of Chain pal.rne Castle. a peak of the Drakenberg, on the boundary between Natal and Basutoland, scarcely more than 100 miles from the Indian Ocean. It flows across the continent in a general westward course, first southwestward Basutoland, then forming in a large bend the southern boun dary of the orange River Colony, after which it flows across the northern part of Cape Colony. and finally forms the boundary 'between the latter and German Southwest Africa until it empties into the Atlantic Ocean. Its total length is nearly 1300 miles. It receives in the upper two-fifths of its course practically all its permanent tributaries, the last and largest of which is the Vaal (q.y.), which is by some geographers considered as the true upper course of the river. Below its con
fluence with the Vaal the orange flows through the arid wilderness of the southern Kalahari region and Namaqualand. In the last 500 miles of its course it receives no permanent tributaries, though several large wad is lead into it. Its volume decreases by evaporation, and at its mouth it is almost exhausted. A sand bar blocks the mouth. In the wet season the river becomes an impetuous torrent. About 20 miles from its mouth it is completely obstructed by rapids, and farther inland, above its confluence with the Molopo Wadi, it forms the famous 'Hundred Falls' or the Great Anghrabies. here the river descends 400 feet in a course of 16 miles in a continuous series of rapids and cataracts between a confusion of high rocky crags. The river re ceived its present name in 1777 in honor of the Douse of Orange. Consult Chavanne, Afrihas Striinie 'and Fliisse (Vienna, 1SS3).