Page:EB1911 - Volume 11.djvu/793

 these above 10,000 were Arabs, Indians, Syrians and Goanese, and 3000 Europeans (over 2000 being Germans). The island of Mafia (see below) is included in the protectorate.

Physical Features.—The coast of German East Africa (often spoken of as the Swahili coast, after the inhabitants of the seaboard) is chiefly composed of coral, is little indented, and is generally low, partly sandy, partly rich alluvial soil covered with dense bush or mangroves. Where the Arabs have established settlements the coco-palm and mango tree introduced by them give variety to the vegetation. The coast plain is from 10 to 30 m. wide and 620 m. long; it is bordered on the west by the precipitous eastern side of the interior plateau of Central Africa. This plateau, considerably tilted from its horizontal position, attains its highest elevation north of Lake Nyasa (see ), where several peaks rise over 7000 ft., one to 9600, while its mean altitude is about 3000 to 4000 ft. From this region the country slopes towards the north-west, and is not distinguished by any considerable mountain ranges. A deep narrow gorge, the so-called “eastern rift-valley,” traverses the middle of the plateau in a meridional direction. In the northern part of the country it spreads into several side valleys, from one of which rises the extinct volcano (q.v.), the highest mountain in Africa (19,321 ft.). Its glaciers send down a thousand rills which combine to form the Pangani river. About 40 m. west of Kilimanjaro is Mount Meru (14,955 ft.), another volcanic peak, with a double crater. The greater steepness of its sides makes Meru in some aspects a more striking object than its taller neighbour. South-east of Mount Kilimanjaro are the Pare Mountains and Usambara highlands, separated from the coast by a comparatively narrow strip of plain. To the south of the Usambara hills, and on the eastern edge of the plateau, are the mountainous regions of Nguru (otherwise Unguru), Useguha and Usagara. As already indicated, the southern half of Victoria Nyanza and the eastern shores, in whole or in part, of Lakes Kivu, Tanganyika and Nyasa, are in German territory. (The lakes are separately described.) Several smaller lakes occur in parts of the eastern rift-valley. Lake (q.v.) north-west of Nyasa is presumably only the remnant of a much larger lake. Its extent varies with the rainfall of each year. North-west of Kilimanjaro is a sheet of water known as the Natron Lake from the mineral alkali it contains. In the northern part of the colony the Victoria Nyanza is the dominant physical feature. The western frontier coincides with part of the eastern wall of another depression, the Central African or Albertine rift-valley, in which lie Tanganyika, Kivu and other lakes. Along the north-west frontier north of Kivu are volcanic peaks (see ).

The country is well watered, but with the exception of the Rufiji the rivers, save for a few miles from their mouths, are unnavigable. The largest streams are the Rovuma and (q.v.), both rising in the central plateau and flowing to the Indian Ocean. Next in importance is the Pangani river, which, as stated above, has its head springs on the slopes of Kilimanjaro. Flowing in a south-easterly direction it reaches the sea after a course of some 250 m. The Wami and Kingani, smaller streams, have their origin in the mountainous region fringing the central plateau, and reach the ocean opposite the island of Zanzibar. Of inland river systems there are four—one draining to Victoria Nyanza, another to Tanganyika, a third to Nyasa and a fourth to Rukwa. Into Victoria Nyanza are emptied, on the east, the waters of the Mori and many smaller streams; on the west, the (q.v.), besides smaller rivers. Into Tanganyika flows the Malagarasi, a considerable river with many affluents, draining the west-central part of the plateau. The Kalambo river, a comparatively small stream near the southern end of Tanganyika, flows in a south-westerly direction. Not far from its mouth there is a magnificent fall, a large volume of water falling 600 ft. sheer over a rocky ledge of horse-shoe shape. Of the streams entering Nyasa the Songwe has been mentioned. The Ruhuhu, which enters Nyasa in, and its tributaries drain a considerable area west of The chief feeders of Lake Rukwa are the Saisi and the Rupa-Songwe.

Mafia Island lies off the coast immediately north of 8° N. It has an area of 200 sq. m. The island is low and fertile, and extensively planted with coco-nut palms. It is continued southwards by an extensive reef, on which stands the chief village, Chobe, the residence of a few Arabs and Banyan traders. Chobe stands on a shallow creek almost inaccessible to shipping.

Geology.—The narrow foot-plateau of British East Africa broadens out to the south of Bagamoyo to a width of over 100 m. This is covered to a considerable extent by rocks of recent and late Tertiary ages. Older Tertiary rocks form the bluffs of Lindi. Cretaceous marls and limestones appear at intervals, extending in places to the edge of the upper plateau, and are extensively developed on the Makonde plateau. They are underlain by Jurassic rocks, from beneath which sandstones and shales yielding Glossopteris browniana var. indica, and therefore of Lower Karroo age, appear in the south but are overlapped on the north by Jurassic strata. The central plateau consists almost entirely of metamorphic rocks with extensive tracts of granite in Unyamwezi. In the vicinity of Lakes Nyasa and Tanganyika, sandstones and shales of Lower Karroo age and yielding seams of coal are considered to owe their position and preservation to being let down by rift faults into hollows of the crystalline rocks. In Karagwe certain quartzites, slates and schistose sandstones resemble the ancient gold-bearing rocks of South Africa.

The volcanic plateau of British East Africa extends over the boundary in the region of Kilimanjaro. Of the sister peaks, Kibo and Mawenzi, the latter is far the oldest and has been greatly denuded, while Kibo retains its crateriform shape intact. The rift-valley faults continue down the depression, marked by numerous volcanoes, in the region of the Natron Lake and Lake Manyara; while the steep walls of the deep depression of Tanganyika and Nyasa represent the western rift system at its maximum development.

Fossil remains of saurians of gigantic size have been found; one thigh bone measures 6 ft. 10 in., the same bone in the Diplodocus Carnegii measuring only 4 ft. 11 in.

Climate.—The warm currents setting landwards from the Indian Ocean bring both moisture and heat, so that the Swahili coast has a higher temperature and heavier rainfall than the Atlantic seaboard under the same parallels of latitude. The mean temperature on the west and east coasts of Africa is 72° and 80° Fahr. respectively, the average rainfall in Angola 36 in., in Dar-es-Salaam 60 in. On the Swahili coast the south-east monsoon begins in April and the north-east monsoon in November. In the interior April brings south-east winds, which continue until about the beginning of October. During the rest of the year changing winds prevail. These winds are charged with moisture, which they part with on ascending the precipitous side of the plateau. Rain comes with the south-east monsoon, and on the northern part of the coast the rainy season is divided into two parts, the great and the little Masika: the former falls in the months of September, October, November; the latter in February and March. In the interior the climate has a more continental character, and is subject to considerable changes of temperature; the rainy season sets in a little earlier the farther west and north the region, and is well marked, the rain beginning in November and ending in April; the rest of the year is dry. On the highest parts of the plateau the climate is almost European, the nights being sometimes exceedingly cold. Kilimanjaro has a climate of its own; the west and south sides of the mountain receive the greatest rainfall, while the east and north sides are dry nearly all the year. Malarial diseases are rather frequent, more so on the coast than farther inland. The Kilimanjaro region is said to enjoy immunity. Smallpox is frequent on the coast, but is diminishing before vaccination; other epidemic diseases are extremely rare.

Flora and Fauna.—The character of the vegetation varies with and depends on moisture, temperature and soil. On the low littoral zone the coast produced a rich tropical bush, in which the mangrove is very prominent. Coco-palms and mango trees have been planted in great numbers, and also many varieties of bananas. The bush is grouped in copses on meadows, which produce a coarse tall grass. The river banks are lined with belts of dense forest, in which useful timber occurs. The Hyphaene palm is frequent, as well as various kinds of gum-producing mimosas. The slopes of the plateau which face the rain-bringing monsoon are in some places covered with primeval forest, in which timber is plentiful. The silk-cotton tree (Bombax ceiba), miomba, tamarisk, copal tree (Hymenaea courbaril) are frequent, besides sycamores, banyan trees (Ficus indica) and the deleb palm (Borassus aethiopum). It is here we find the Landolphia florida, which yields the best rubber. The plateau is partly grass land without bush and forest, partly steppe covered with mimosa bush, which sometimes is almost impenetrable. Mount Kilimanjaro and Mount Meru exhibit on a vertical scale the various forms of vegetation which characterize East Africa (see ).

East Africa is rich in all kinds of antelope, and the elephant, rhinoceros and hippopotamus are still plentiful in parts. Characteristic are the giraffe, the chimpanzee and the ostrich. Buffaloes and zebras occur in two or three varieties. Lions and leopards are found throughout the country. Crocodiles are numerous in all the larger rivers. Snakes, many venomous, abound. Of birds there are comparatively few on the steppe, but by rivers, lakes and swamps they are found in thousands. Locusts occasion much damage, and ants of various kinds are often a plague. The tsetse fly (Glossina morsitans) infests several districts; the sand-flea has been imported from the west coast. Land and water turtles are numerous.

Inhabitants.—On the coast and at the chief settlements inland are Arab and Indian immigrants, who are merchants and agriculturists. The (q.v.) are a mixed Bantu and Semitic race inhabiting the seaboard. The inhabitants of the interior may be divided into two classes, those namely of Bantu and those of Hamitic stock. What may be called the indigenous population consists of the older Bantu races. These tribes have been subject to the intrusion from the south of more recent Bantu folk, such as the Yao, belonging to the Ama-Zulu branch of the race, while from the north there has been an immigration of Hamito-Negroid peoples. Of these the Masai and Wakuafi are found in the region between Victoria Nyanza and Kilimanjaro. The (q.v.) and allied tribes are nomads and cattle raisers. They are warlike,