That the vast network of rivers on the Guinea coast, of which the Nun was the chief, known as the Oil rivers, formed the delta of the Niger does not appear to have been suspected before the beginning of the 19th century. Consequently it was from the direction of its source that the river was first explored in modern times. In 1795 Mungo Park (q.v.), sent out by the African As sociation, landed at the Gambia, and struck the Niger near Segu on July 20, 1796, where he beheld it "glittering in the morning sun as broad as the Thames at Westminster and flowing slowly to the eastward" (Travels, ist ed., p. 194). He descended the river some distance, and on his return journey went up stream as far as Bamako. In 1805 Park returned to Africa for the pur pose of descending the Niger to its mouth. From Bamako he sailed down the river for over 2,000 miles and on the eve of the successful accomplishment of his undertaking lost his life during an attack on his boat by the natives at Bussa (Nov. or Dec. 1805). Park held to the opinion that the Niger and Congo were one river, though in 1802 C. G. Reichard, a German geog rapher, had suggested that the Rio Nun was the mouth of the Niger. Owing to Park's death the results of his second journey were lost, and the work had to be begun afresh. In 1822 Maj. A. G. Laing (who had reached Timbuktu by way of Tripoli) obtained some accurate information concerning the sources of the river, and in 1828 the French explorer Rene Caillie went by boat from Jenne to the port of Timbuktu. In 1826 Bussa was reached from Benin by Hugh Clapperton, and his servant Richard Lander. On Clapperton's death Richard Lander and his brother John led in 1830 an expedition which went overland from Badagry to the Niger. Canoeing down the river from Yauri-6o m. above Bussa—to the mouth of the Rio Nun they finally settled the doubt as to the lower course of the stream.
Heinrich Barth (1351-54) made known to Europe the course of the river from Timbuktu to Say. Later, the extension of French influence throughout the western Sudan led to an ac curate knowledge of the river above Timbuktu. From 188o on wards Col. (afterward General) Gallieni took a leading part in the operations on the upper river, where in 1883 a small gun boat, the "Niger," was launched for the protection of the newly established French posts. In 1885 a voyage was made by Capt. Delanneau past the ruins of Sansandig, as far as Diafarabe. In 1887 the "Niger" made a more extended voyage, reaching the port of Timbuktu. A more important expedition was that of Lieut. Hourst, who, starting from Timbuktu in Jan. 1896, navi gated the Niger from that point to its mouth, executing a careful survey of the river and the various obstructions to navigation.
In addition to the main stream, the Niger basin was made known during the last quarter of the 19th century and the early years of the 20th. The journeys of the German traveller G. A. Krause (north from the Gold Coast, 1886-87) and the French Capt. Binger (Senegal to Ivory Coast, 1887-89) first defined its southern limits by revealing the unexpected northward exten sion of the basins of the Guinea coast streams, especially the Volta and Komoe, a fact which explained the absence of im portant tributaries within the Niger bend. The exploration of the Benue dates from the middle of the 19th century. In 1851
Barth crossed the Benue at its junction with the Faro, but the region of its sources was first explored by the German E. R. Flegel (1882-84), who traversed the whole southern basin of the river and reached Ngaundere. The Benue itself had been ascended 400 m. by the "Pleiad" expedition in 1854 and in 1889 the river was traced to 131° E., and Kebbi to Bifara by Maj. (afterwards Sir Claude) Macdonald, further progress towards the Tuburi marsh being prevented by the shallowness of the water. In 1903, a French officer, Capt. E. Lenfant (who had in 1901 succeeded in navigating the Bussa rapids on the Niger) ascended the Kebbi and discovered the Lata fall, continuing up the river to its point of issue from Tuburi. Crossing the marshes he found and navigated the narrow river leading to the Logone. Save for the portage round the Lata fall the whole journey from the mouth of the Niger to Lake Chad was made by water.
From Kulikoro (which is connected by railway with the port of Dakar) downward, the French have undertaken works on the Niger with a view to deepening the channel, and they maintain a regular steamer service to the port of Timbuktu. In 1910 the British began dredging with the object of obtaining in the lower river a minimum depth of 6 ft. of water; however, while there is still a large river traffic the building of railways in Nigeria has deprived the lower Niger and the Benue of their importance as highways of commerce to the far interior.
For the Benue see, besides Barth's Travels, A. F. Mockler Ferryman, Up the Niger; Narrative of Major Claude Macdonald's Mission to the Niger and Benue Rivers . . . (London, 1892) ; L. Mizon, "Itiner aire de la source de la Benoue au confluent des rivieres Kadei et Mambere" and other papers in the Bull. Soc. Geog. Paris, for 1895 and 1896 ; E. Lenfant, La Grande Route du Chad (Paris, 1905) ; B. Alexander, From the Niger to the Nile, vol. i. (London, 1907). An Atlas du tours du Niger de Timbouktou aux rapides de Boussa in 5o sheets on the scale of :50,00o, by Lieut. Hourst and others, was published in Paris in 1899. (F. R. C.)