What is known of the physical features of A. may be shortly sketched under the fol lowing heads: 1. The triangular region s. of cape Guardafui and the gulf of Guinea is mostly a high table-land, having fringes of mountains crowning its edges. Between the coast and the beginning of the elevation runs a belt of lowlands, varying from 50 to 300 m. in breadth. The Lupata range, seen running parallel with the coast, 'forms the eastern crest of the table-land. between 3° and 4° s. lat., it reaches, in the snow-clad Kilimand jaro and Kenia, the height of 20,0001t. The mountainous country of Abyssinia is the eastern prolongation of the plateau and its elevated crest; in the summit of Abba Yared, at the northern extremity, it rises to 15,000 ft. At the a., thelills of Cape Colony rise in stages from Table mount to the summits of the Nieuwveld and Sneeuwberg, in the n. of the colony, which are estimated at 7000 to 10,000 ft.; the spacesbetween the ranges being shrubby kloofs or valleys, and broad elevated terraces or kar•oos. From the elevated crest that runs parallel to the w. coast from Cape Colony to Valfish bay, Mr. Galton describes the country as sloping slightly inwards, thus giving a cup or basin shaped appearance to the interior of the continent. Towards the n.w. the border of the table-land rises in the Cameroons to the height of 13,000 ft. Its northern boundary is not determined: but it is likely that the valley of the western branch of the Nile penetrates into it, dividing it into two portions, an eastern and a western. A mountain seen lying s. from lake Tchad is supposed to be one of its northern outposts.
2. North and n.w. of the great triangular table-land lies Sudan or central Nigritia, under which name may be comprehended the countries watered by the Senegal, Gam bia and Niger, along with the coast of lower Guinea, and the basin of lake Tchad. In the w. of this section is a mountainous table-land of no great elevation, hi which the rivers above named take their rise; the Kong mountains, which run parallel to the Guinea coast, are a branch of this elevation. Eastward of the Niger the country is hilly, alternating with rich, often swampy plains. In the basin of lake Tchad is avast alluvial plain, one of the largest on the globe, and of great fertility.
3. Between Sudan and the cultivated tract which borders the Mediterranean, stretches the Sahara or great desert. It extends s. nearly to the Senegal, the northern bend of the Niger, and lake Tchad, northward to the Atlas range in Morocco and Algeria, and towards Egypt it reaches to the Mediterranean. Its average breadth from n. to s. is about 1000 nu Its length from the Atlantic to the western edge of the valley of the Nile is 2000. Over a great part of this region rain never falls, and everywhere it is rare; it is thus condemned to sterility. It consists partly of tracts of fine shifting sand, which frequent storms of wind raise into the air, so as often to overwhelm travelers. But the greater part of the surface consists of naked but firm soil, composed of indurated sand, sand stone, granite and quartz-rocks, often rising into ridges or hills. The desolation is
interrupted at intervals by patches, sometimes of considerable extent, covered with bushes and coarse grass, and often of great beauty and fertility. These oases or wadies, as they are called, which are occasioned by subterranean springs, are most numerous and fertile in the eastern portion of the desert. The easiest route across the desert to Sudan runs from Tripoli through the kingdom of Fezzan to lake Tchad. Fezzan enjoys peri odic rain from the moist winds of the Mediterranean, which extends further into the con tinent here than elsewhere. The portion of the desert lying e. of the route above described is called the Libynn desert. It is chiefly in this region that the oases are susceptible of cul tivation; the tracts of vegetation in the western portion are fit for little else that] pasture, mainly for goats and sheep. The principal production of the more fertile oases is dates; but other fruits and grain are also cultivated. Gum-arabic is another production. Some of the larger oases support thousands of inhabitants living in villages. Commerce is carried on across the desert by various routes by means of caravans, consisting of from 500 to 2000 camels, with their attendants. The distance between the wells sometimes exceeds 10 days' journey; and when a well is found dry men and animals are in danger of perishing. The inhabitants consist of independent tribes of Moors, Berbers and Arabs.
4. The Atlas region, comprehending the mountainous countries of Morocco, Algeria and Tunis. The northern slope towards the Mediterranean, called the Tell, is, in aspect, climate and productions, similar to the opposite coast of Europe the southern side merges gradually into the Sahara. Some parts of the chain are considerably above the snow-line, and the highest summits may reach 13,000 ft.
5. The region bordering on the Red sea, consisting of Abyssinia, Nubia and Egypt. Abyssinia, we have seen, is the mountainous termination of the great southern plateau. Between this and the Mediterraucan extends the low valley of the Nile, separated from the Red sea on the e. by a rugged mountainous region, and from the Libyan desert on the w. by a low ridge of limestone and sandstone.
Regarding the hydrography of A., much is still to be ascertained. Livingstone's dis coveries have shown that the portion which, until recently, was termed the " unexplored territory," is anything but the barren and riverless desert that we imagined. But as hardly one of its streams has been traced throughout its entire course, while nearly the entire tributaries of these are very imperfectly known, we must wait forum result of fur ther explorations, before positive statements can safely be made. Those of the s., which mostly rise in the neighboring highlands, are, in many instances, little better than moun tain-torrents, having short and rapid courses; and the embouchure, generally in the delta form, is commonly obstructed by a bar of sand. The Orange river, for instance, is filled with sand at its mouth.