In 1856 Du Chaillu explored the southern Ogowe, and, in 1864, penetrated into Ashango and discovered the dwarfs of Obongo. In 1858 Burton discovered Lake Tanganyika. In 1858 Lake Vic toria Nyanza, then called Ukerewe, was discovered by Speke, who, in 1862, was able to prove that its overflow constituted the origin of the Nile. In 1864 Sir Samuel Baker discovered Lake Albert Nyanza, and later Stanley discovered Lake Albert Edward Nyanza. In 1849 1856 Livingstone discovered Lake Ngami, crossed the Kalahari desert, and re turned across Africa from St. Paul de Loanda to the mouth of the Zambezi, being the first to accomplish this feat. In 1859 he discovered the Nyassa and Chilwa lakes. In 1858-1864 he explored the Zambezi and its tributaries; in 1867 1868 he discovered Lakes Mweru and Bangweolo; and, from 1868 to his death in 1873, he investigated Lake Tanganyika and the headwaters of the Kongo. In 1871 he was found by Stanley at Ujiji. The desire to solve the problem of the Kongo basin led to many expeditions, but the final solution was obtained by Stanley in his journey across the con tinent in 1874-1877; he showed that the origin of the Kongo was to be found in the Lualaba and the Luapula or Cham beze. The latter, he proved, passes through Lake Bangweolo and joins it with Lake Mweru. He also succeeded in strictly defining the sources of the Nile. In 1884-1885 Grenfell preyed the identity of the Ubanggi, the principal tributary of the Kongo, with the Makua or Welle, names previously given to its upper course.
Later Discoveries.—In 1893 and 1894 Marchand explored the regions of Great Bassani on the Ivory Coast, directly N. to the junction of the Bagoe and the Niger. In 1890 Marine!, and, in 1891, Bia, reached the S. E. sources of the Kongo in Kantaga. In 1893 Mohun proved the non-existence of Lake Landji. In 1891 and 1894 De la Khetulle explored from Ubangi to Dar Nefertit. In 1891 Crampel and Dybowski were the first Europeans to cross the Kongo Shari watershed. In 1892 and 1893 Maistre succeeded in penetrating from Ubangi to Logoni and Binue. In 1891 Fourneau, in 1891-1894 Brazza, and in 1895 Clozel, explored the Sanga Mambere, an affluent of the lower Kongo. A number of ex plorers also have penetrated the equa torial W. coast: Bottego and Grixioni, 1892 and 1893; Prince Ruspoli, 1893 and 1894; Count Hoyos, 1893 and 1894. Donaldson Smith in 1894 and 1895 ex plored the interior of Somaliland. The highlands between Tana, Sabaki, and Kenia were explored by Pigott, Hanel, and Chanler. Baumann, Stuhlmann, and Verther crossed the Massai steppe. The expedition of Shele in 1894, of Marenski in 1892, and Bumiller, also gave im portant information regarding the southern half of the German boundary.
In the first years of the 20th century great progress was made in scientific exploration in Africa. Previous to that
time indeed, Marchand traversed the continent from Loanga in French Kongo to Fashoda on the Nile. The Lake Tchad region and the Sahara desert were trav ersed at the same time by other French explorers. Between 1900 and 1904 Pierre crossed the continent following in General Marchand's route. In 1909 Gautier crossed the Sahara desert from Tuat to the Niger river. German ex plorers also were active at this period. Dr. Stuhlmann made a study of the region of Victoria Nyanza and Dr. Hans Meyer made the first ascent of Mount Kilimanjaro.
By this time the era of exploration began to be superseded by one of detailed study of the geography of Africa, the ethnology of its people and the variety and quantity of its resources. This work advanced so rapidly that by 1913 the continent had practically been charted and mapped and the colonization of various portions had been well begun, especially in British and German East Africa. In Rhodesia and other British colonies agriculture and mining were de veloped on a considerable scale. Rail way construction also developed. In 1913 the copper field of Katanga in Belgian Kongo was connected by rail with Capetown, over 2,100 miles to the south. A line from Cairo was extended to Senaar on the Blue Nile, and a branch of the White Nile had been built at El Obeid, the capital of Kordofan. In the Belgian Kongo railroads had been con 3tructed around all the rapids of the upper Kongo. The great lakes, Victoria Nyanza and Tanganyika, were connected by rail with the Indian Ocean, while another railway connected the upper and middle Niger with the sea.
The progress of the World War natu rally suspended development and explo ration in Africa. In spite of this, how ever, several important expeditions carried on work during the years 1916 to 1920. Among these was the Collins Gamier French Kongo Expedition which were working in the interests of the Smithsonian Institution. While the ob jects of the expedition were largely scientific, many important geographical results were obtained. Another party, also in the interests of the Smithsonian Institution, under the direction of Ed mund Heller, carried on explorations in the Cape region and western Rhodesia.
Population.—Recent authorities rough ly estimate the population of Africa at about 140,000,000. About 34,000,000, all of Semitic stock, are intruders from Asia, some in remote or prehistoric times (3, 000,000 Himyarites in Abyssinia and Harar, from south Arabia), some since the spread of Islam (over 30,000,000 nomad and other Arabs, chiefly along the Mediterranean seaboard, in west Sahara, and central and east Sudan). All the rest, altogether, may be regarded as the true aboriginal element, and as falling into two main groups—the negro and negroid peoples, and the Hamitic.