Niger, the name now generally applied to one of the most remarkable river-systems of West Equatorial Africa, first appears in Ptolemy as designating, it is believed, the modern Wadi Draa, and coupled with a river Gir, which may be identified with the modern O-Guir, flowing southward from the Atlas towards the oases of Tuat. The word not improbably contains the root gir, gar, or jur, not infrequent in the river-names of northern Africa. Mixed up as it was from time to time with the problem of the Nile, the problem of the Niger remained almost till the 19th century one of the most perplexed and bemuddled in the whole range of geography. Though the Portuguese had ascended the river from the sea in the 16th century, the most contradictory opinions were held as to its character and relations down to the later part of the 18th century: it was an affluent of the Nile; an affluent of the Congo; an independent river terminating in an inland basin; and so on. It was still left to Mungo Park and other workers in the service of the African Association (1788) to lay the basis of our present fairly accurate knowledge of the system. Apart from some of the tributary streams, the hundred years of exploration now leave only a blank of some 60 or 70 miles in the middle course of the main river.
The Niger proper (Joliba or Dhiuliba, Isa, Kworra or Quorra, &c.) has a total length of 2600 miles, and the area of the entire basin (including that of the Benuë) is estimated at 1,023,280 sq. m. The head-waters are situated in the region now known as the States of Samory, inland from Sierra Leone and Liberia, and are contiguous to the head-waters of the Senegal. The Tembi (first explored by Zweifel and Moustier in 1879), rising at a height of about 3000 feet above the sea in the Loma Mountains in 8° 36' N. lat. and 10° 33' W. long., is now accepted as the conventional 'source.' This and its sister streams, though draining a comparatively limited area, soon gather into a good navigable river, which holds a north-easterly course as far as Timbuktu (18° 4' N. lat., 1° 45' W. long.), first visited by Laing in 1826. About 300 miles above this famous city it is joined by an important right-hand tributary, the Mayel-Balevel, and develops a tendency to split up into numerous and widely diverging channels, with cross-creeks, back-waters, and swamps. Beyond Timbuktu a more easterly direction is maintained for 200 miles, and then with its now united forces the Niger turns south-east to cut its way through a rocky tract of country, and to pass in succession Gao (Gogo) on the southern skirt of the Sahara; Say, the southern point of Barth's exploration; Gompâ, the northern limit of Flegel and Thomson; Bussa, where Park came to his untimely end; and Rabba, one of the largest cities on its course. During this long journey from Timbuktu (1130 miles) a chief characteristic of the Niger has been the insignificance of its tributary streams; but at last, in 7° 50' N. lat., 6° 45' E. long., it meets in the Benuë, or Mother of Waters, a rival both in volume and in beauty.
See Joseph Thomson, Mungo Park and the Niger (1890); Mockler-Ferryman, Up the Niger (1893); and Keltie, The Partition of Africa (1893).