Africa, one of the great continental divisions of the globe, situated in the eastern hemisphere, S. of Europe, from which it is separated by the Mediterranean sea, and S. W. of Asia, with which it was formerly connected by the isthmus of Suez. Since the opening of the canal between the Mediterranean and the Red sea, Africa may be described as an insular continent. It lies between lat. 37° 20' N. and 34°
50' S., and lon. 17° 30' W. and 51° 30' E., being thus almost wholly within the tropics. Its figure resembles that of an irregular triangle. Its greatest length, measured from Cape Agul-has, E. of the Cape of Good Hope, to Cape Bianco, near Bizerta in Tunis, is 4,330 geographical miles; and its greatest width, from Cape Verd on the Atlantic to Cape Guarda-fui, on the Indian ocean, is 4,000 geographical miles. The entire area of the continent, exclusive of Madagascar and the other African islands, is estimated at 11,360,000 statute square miles. The derivation of the name, which was originally applied only to the country around Carthage, is uncertain. Within the last 25 years our knowledge of African geography has been so largely increased that the leading physical features of the country are now pretty well known. - Southern Africa is a vast table land, not of great elevation, which on its N. edge slopes down to the rich equatorial plain of Soodan, and thence to the lowland region which constitutes the greater part of northern Africa. The mountain ridges of Senegambia on the west, and the lofty plateau of Abyssinia on the east, are outlying offshoots of the southern table land, stretching forth from it like rocky promontories into a sea of level country.
The Atlas range in the northwest is the only other elevated region of importance. - The coast line of Africa is remarkable for its continuity, as well as for its lack of good harbors. It is about 16,000 m. in length, so that for every 710 sq. m. of continental area, according to the estimate above given, there is only one linear mile of coast, a smaller proportion of seashore to surface than in America, Asia, or Europe. The surrounding seas comprise the Mediterranean on the north, the Red sea and Indian ocean on the east, the Southern ocean on the south, and the Atlantic on the west. The island of Madagascar is separated from the S. E. portion of the mainland by the Mozambique channel, 250 m. wide. Just above the equator the breadth of the continent is considerably narrowed by the westward trend of the Atlantic coast through about 15 degrees of longitude, from Cape Palmas to the head of the bight of Biafra, where it resumes its southerly course. The seaboard of this region is washed by the waters of the gulf of Guinea. The most prominent points on the Mediterranean coast are Cape Bon, in Tunis, opposite Sicily, and Cape Spartel, the extremity of a spur from the Atlas mountains forming the African side of the straits of Gibraltar. At the gulf of Sidra, the Syrtis Major of the ancients, in Tripoli, the sands of the Sahara reach the shore; and E. of this locality to the delta of the Nile the coast country is flat and unproductive.
In Algeria the Atlas foot hills approach the sea, and the contiguous district is well adapted for cultivation. The Sahara desert again borders the shore on the Atlantic coast of northern Africa; and further S. lie the luxuriant but unhealthy lowland delta districts of Senegambia, whence projects Cape Verd, so named from its rich green covering of gigantic baobab trees. Approaching the equator, these are succeeded by a country still more fatal to man, in the mangrove swamps and reedy shore growths of the Guinea coast. On the Red sea, a range of mountains originating in Abyssinia skirts the W. shore and descends on the north to the lower hills of Egypt, which are geologically connected with the Sinaitic peninsula. The maritime edge of the great South African plateau is bounded for the most part by mountain chains of various altitude, with shelving plains on their seaward slope. Between the E. and W. coasts which border the table land there is a marked difference. Along the Atlantic a series of terraces rises into the interior, intersected in some localities by low, level plains and fever-breeding swamps, and in others by grassy tracts and extensive forests. The highest of these terraces does not exceed 2,000 feet above the sea.
From Cape Negro, in Ben-guela, to the mouth of the Orange river, the coast is a low desert backed by a sandstone ridge, beyond which extends the lofty but no less arid inland region. Along this 900 m. of seaboard there is not a single drop of fresh water, and not a spot of fertility except at Walvisch bay. The coast of Cape Colony is bold and rocky; in Natal the surface rises gradually from the sea to the Drakenberg range, and thence northward to the Zambesi; the shore consists of highlands which in some localities attain the elevation of lofty mountains. Well watered and fertile plains occur opposite Zanzibar, but further N. the country becomes more sterile, and a desert occupies that portion of the continent comprised between lat. 4° N. and Cape Guardafui, its E. extremity. The strait of Bab-el-Mandeb, 20 m. broad, separates Africa from Asia, at the entrance to the Red sea. On the African side the coast is rugged, and rises abruptly from the sea, though only to the height of 380 feet. - Considered with reference to continental location, the mountains of Africa may be classed in five systems, as follows: 1, the mountains of the Mediterranean basin, comprising the three ranges of the Atlas; 2, the mountains of the W. coast; 3, the parallel chains of the Cape region; 4, the mountains of the E. coast; and 5, the Abyssinian group.
Isolated from the other parts of the continent by the Great Desert, the Atlas mountains extend across the N. W. portion, from the Mediterranean shores of Tunis to Agadir on the Atlantic coast of Morocco. The Lesser Atlas is the lowest range of this system and nearest the Mediterranean; a little further inland the broad table land known as the Middle Atlas rises still higher; and above this towers the jagged ridge of the Greater Atlas, in many points attaining an elevation of 12,500 ft. It has commonly been represented that these loftier peaks were above the line of perpetual snow; but according to Dr. J. D. Hooker, the English botanist, who succeeded in ascending to the crest of the range near the city of Morocco in 1871, all the snow that falls on fairly exposed surfaces melts in the same year. Several spurs are thrown out from the main chain toward the Sahara, and one trends northward to the straits of Gibraltar. Little is known about the mountains of western Africa, except those in close proximity to the coast. Senegambia includes an elevated region which forms the watershed whence flow the Niger and the Senegal; while in Guinea, N. of the gulf, are the Kong mountains, nowhere exceeding 3,500 ft. in height.