Stretching northward from the Zambezi River to the Red Sea is that great eastern highland which attains its most extensive development just south of the equator in the region about. the Victoria Nyanza. Through a. large part of its extent this highland maintains an elevation of over 5000 feet, which in Abyssinia rises over considerable 'urea. to heights of six, eight, and ten thousand feet. The main highland extends northward nearly to Suakin, and a narrow. interrupted spur reaches east ward from lakes Abba and ?Amway to the apex of the Somali Pen insula, with peaks declining in height from Mount Mulata (9840 feet) to Godobb (4875 feet) at Cape Guardafui. The surface of this eastern highland is traversed longitudinally by a great system of so-called rift-valleys that constitute the most important feature of East A friean topog raphy. and with which is associated a system of great lakes. These tift-valleys ma rk the course of parallel cracks in the earth's crust, be tween which the surface has sunk for thousands of feet, forming narrow, elongated depressions, or broad eafions. with precipitous walls that rise to the broken edges of the high-level plateau. In these rift-valleys lie the majority of the great African lakes, most of which, consequently, are of elongated form. The longest of these rifts has its northern end in Pale-tine, in the ,lordan and Dead Sea valleys: it forms the Red Sea Basin southward to the Straits of Bab-el-Man deb. where it is joined by a broader rift that emits from the east, forms the Gulf of Aden, and continues southwestward throutdi French Somaliland and the Galla country into British East Africa to lakes Stephanie and Rudolf. At this point the rift-valley divides. Ono branch eontinues southward to beyond Lake Man yara. and another trends westward from Lake Rudolf to Lake Albert, and then southward to Lake Shirwa at the southern end of the eastern In addition to these great rift-valleys there are many smaller fracture lines throughout the entire highlands that exercise eonsiderable control over the smaller drainage features.
In the vicinity of the rifts are found the high est mountains, and in general the °nurses of the great rifts mark the location of x-oleanie peaks. The StIONV-thpped Ruwenzori Range, with its central peak rising to 16.000 feet, is among the nest important of African mountain ranges. and it appears to be largely of volcanic or laccolitic origin. South of Lake Albert Ed. ward. on the eastern side of time western rift valley, is a group of volvanie some of which are active, eulminating in Mount Ki runga (4350 feet). The most extensive volcanic district, however, lies along the eastern rift valley and on the Abyssinian highland. Kili manjaro 119.720 feet) and Keith' (17.200 feet I, two isolated. snow-clad, volcanic peaks, rise from the eastern margin of this rift-valley mar its southern termination. About the southern half of Lake Itudoll is a ,scries of volcanic peaks, where several active cones rise 2000 feet above the plains, the best known of which is Teleki. Several very high monniaillS lie between Lake Rudolf and the Victoria Nyanza. the highest of which is Mount Elgon (14.03(1 feet). The Abys sinian highland is topped by massive fields of ancient lava, from witieh rise extinct volcanic peaks to heights of ;Mont 15.0(10 feet I Nlonnts
Dashan, Abba-Tared, etc.). A few active vol canoes °emir on the northeastern slopes of Abys sinia, near the shore of the Rod Sea, where a chain of mountains presents summits of 0000 to 10.000 feet.
The great topographical feature of West Cen tral Africa is the Congo Basin, equaling, in area the basin of the and stretching from lat. 12° S. to lat. 0° N., and from long. 33° to about 10° E., where it narrows into the restricted valley by which the river makes its way through the eoastal mountains to the At lantic Ocean. The whole of this area is an ele vated plain, sloping gradually front all sides toward the middle west. where the vast outlet d•bouches. in lat. 0° S. It presents no elevated regions worthy of mention. except about the borders. The southeast watershed is not. high, nor is that on the south. which separates che Congo waters from those flowing into Lake Ngami or collected by the Zambezi. North if Lake Tan ganyika the high mountains form a lofty water shed between the northeastern sources of the Congo and the sources of the Nile, and a line of hills sweeps around to the westward in the southern Sudan. and are continued to the lofty .lebel-el-Nlarra. in Darfur. whose slopes contri bute the remnotest northern waters of the Congo. The high ranges of Adamawa and the coast mountains separate its more westerly northern tributaries from the Ogowe and other coastal rivers. The mountains which separate the ('on go Basin from the coast are rather the broken eroded margin of the continental plateau than true mountains, and few if any peaks exceed 5000 feet in height.
The topographical division of Sudan covers the equatorial area between the watershed of the Congo and the Sahara Desert, from the head waters of the Bahr-el-Ghazal, a tributary of the Nile, to the mountains of the coast—that is, the drainage basins of Lake ('had and of the Niger. The basin of Lake Chad is an inclosed area almost in the centre of the continent, its southern margin being removed but a few hun dred miles from the head of the Gulf of Guinea. The lake itself has no outlet, and lies about 000 feet above the sea. The eastern border of this is separated from the Nile waters by a line of highlands which continue northward across the desert, and ntlyb culminate in Darfur in the Itlountains, rising some 7000 feet. above the plain. and forming a watershed for eastern Sudan. The western border of the ('hail Basin is formed by rocky plateaus. which constitute a di vide between this and the Niger Basin; and a uni form plain, diversified by rocky hills. stretches westward to the coast mountains. Large por tions of the Chad Basin are dry and open. while other extensive areas are forested or swampy, passing northward into desert. At the head of the Gulf of Guinea are the Kamerun Mountains, more than 13,000 feet high. Further westward along the coast of Upper Guinea there are moun tains, but of no great height, the supposed "Kong Range" of old geographies having been proved non-existent. The highest peaks of the hinter land of Sierra Leone and the Slandingo Moun tains do not exceed 3500 feet, except in the Peak of Komono (4600 feet). The coast of Senegal is fiat; that more southerly, except in Liberia, swampy; all the rivers, and especially the Niger, form extensive deltas.