ADMINISTRATIVE DIVISIONS 15 thousands of square miles of swamps, the highest land in amongst them rising only a few feet above water-level, intersected by the Rivers Zeraf, Mountain Nile, and the system of the Bahr-el-Ghazal.

When, in the course of a journey up some branch of the latter river, whose ramifications extend over the whole province, the lowest-lying area is passed, a tropical country is entered which is favourable to the growth of fine timber, and, still more important, is situated within the zone suitable for the planting of rubber, in the cultivation of which important experiments are being made.

The Blue Nile and the Atbara both rise in the neighbourhood of Lake Tsana, far up in Abyssinia, and at the point of its entrance the former, with some hundreds of miles of its course still before it, is only 150 miles distant from the main stream of the White Nile.

For administrative purposes the country is divided into thirteen provinces, of which the most important are those of Dongola, Berber, and Khartoum, in the north ; Sennaar and Kassala in the east ; Kordofan in the west ; and the Upper Nile and Bahr-el-Ghazal in the south. The chief towns of these are, respectively, Merowe, El Damer, Khartoum, Singa, Kassala, El Obeid, Kodok, and Wau. Dueim, the gate of Kordofan, is a flourishing port ; but Omdurman, originally containing a vast population, decreases in numbers, while Khartoum North expands daily with the increase of commerce and occupation.