ABSTRACT
The river Nile is the life blood of Egypt. Indeed to all intents and purposes it is Egypt. For eight hundred miles or more from Wadi Haifa to the southern approaches to Cairo its six-mile wide valley is virtually the only inhabitable land. Rainfall over Egypt is very slight. Without the Nile with its annual floods fertilising and bathing the land not even 15,000 of Egypt's 383,000 square miles would be able to support human life. The Nile's waters and the Nile floods depend on the movement of a belt of rain from the Equator northwards from March to July, the rain itself being most probably Atlantic in origin carried across Africa by the prevailing winds and precipitated over the Congo basin, the Ethiopian highlands and the high mountain masses of central Africa 1 . From these precipitations rise the two great tributaries of the Nile, the White Nile rising on a 6,000 foot plateau just north of Lake Tanganyika, and the Blue Nile with its principal tributary, the Atbara, rising in the eastern highlands of Ethiopia around Lake Tana. From the White Nile, which passes through the Great African lakes of Victoria and Albert and loses much of its volume in the swamps of the southern Sudan, the Nile derives its regular all-the-year round flow. From the Blue Nile and the Atbara come the floods.
