THE ANGLO-EGYPTIAN SUDAN The Sudan, which is under the joint control of Great Britain and Egypt, has an area of about 1,000,000 square miles. Its population, which is now about 3,000,000, at one time numbered 9,000,000, but was reduced during the Dervish tyranny to less than 2,000,000.
The climate varies greatly from one region to another. Except along the Red Sea littoral south of Suakin, rain seldom falls north of the 17th parallel, but south of it there is a gradual increase both towards the equator and towards the Abyssinian mountains. Over a great part of the basin of the Bahr-el-Ghazal, and of the country between the Bahr-el-Jebel and the Sobat, there is a mean annual rainfall of from 30 to 40 inches ; while in the extreme south, where there is a double rainy season, the amount received is still greater. The mean temperature is generally high. Such observa tions as have yet been made seem to indicate that at Berber it varies from 67° F. in January to 94° F. in June ; at Khartum from 69° F. in January to 92° F. in May and June ; and at Mongalla from 77° F. in July to 82° F. in March.
The natural regions of the country may most conveniently be studied by observing the relation of vegetation to rainfall. To the north of the 17th parallel, desert conditions prevail except along the banks of the Nile, where there is a riverine population engaged in agriculture ; in a few oases scattered here and there ; and in the districts south of Suakin, where cultivation is possible in some of the wadis and on irrigated land, such as that at Tokar on which cotton is grown.
South of the rainless area there lies a belt of country which, as regards its vegetation, is transitional between the desert to the north and the true savanna to the south. The northern parts con sist, in the main, of poor scrub-land, but further south there are forests of acacia and large areas of grassland, on which in years of good rainfall a considerable amount of agriculture is possible. Dhurra (a kind of millet), beans, lentils, melons, and onions, as well as some wheat and barley, are all grown ; and in many places, as in the south of Darfur and in the Gezira (the country between the White and the Blue Nile), there is good grazing for cattle and sheep. In the forests of " hashab " (Acacia verek), in the south of Kordofan, gum, one of the most important exports of the Sudan, is found in large quantities, and some ivory and ostrich feathers are also obtained from that province. Along the banks of the
White Nile and the Blue Nile, agriculture is more profitable and the population is denser, but the further development of the land in the neighbourhood of these two rivers depends upon the extent to which they may ultimately be used for purposes of irrigation. At the present time, the quantity of water which may be withdrawn from them is, in the interest of Egypt, strictly limited, but it is believed that, owing to the much higher winter temperature which prevails in the Sudan, certain crops can be grown there during that part of the year in which Egypt does not demand water. Investigations in this direction are at present being made in the Gezira, which forms a vast alluvial plain, somewhat more fertile in the east where it has been built up by the deposits of the Blue Nile. It is generally covered with grass and scrub, and is occupied by semi-nomadic peoples, who cultivate considerable areas during the rains, but move with their herds towards the rivers during the dry season. At Tayibai, on the Blue Nile, experiments made in the cultivation of cotton have given very satisfactory results, and it is proposed to construct an irrigation canal which, leaving the Blue Nile at Sennar, will run in the direction of Khartum, and enable a considerable area to be cultivated with cotton and wheat. Other schemes under consideration for the development of irriga tion in the Gezira and Kordofan involve the re-modelling and embanking of the Bahr-el-Jebel, and the construction of a reservoir at Khartum to bring wide tracts of country in Kordofan under flood irrigation. But progress in these directions must, necessarily, be slow.
In the southern Sudan, where there is a rainfall of over 30 inches, the vegetation assumes a richer and more varied form. The forests contain rubber-producing plants, such as Landolphia owariensis, and valuable timbers, such as African mahogany ; while on the extensive grasslands a good deal of cultivation is carried on by native tribes. Ivory, rubber, and some iron worked by the inhab itants of the Bahr-el-Ghazal province, constitute the chief exports of the region.