12 PAST AGES OF CONQUEST southward, the Itahan colony of Erithrea and the great empire of Abyssinia, on the water-supply from whose hills Egypt at present is absolutely dependent for fruitful existence, are interposed between it and the sea ; while in lower latitudes still, where even the Sudan itself has scarcely been traversed, the arid country is in the hands of entirely savage people.

About 1,300 miles due south of the Egyptian boundary as the crow flies, Uganda and the Congo Free State form the southern frontier, the latter extending northwards to join the farthest and leastknown confines of the French Sudan as the enclosing areas on the west, out of which appeared Marchand as " a bolt from the blue " on his way to Fashoda.

The whole importance of the country naturally depends on the river, which follows the great line of surface depression extending from Lake Nyassa to Syria and marked by the chain of Central African lakes, the Nile, and the Dead Sea. In the Sudan the retaining boundaries consist of the mountains of Abyssinia and of the Atbai district on the east, and the ridge on the west which separates Congo and Nile.

The drainage area of the Nile is divided into three great sections ; the greatest extends far beyond the limits of the Sudan into the Uganda Protectorate, where the long-sought source was located as the Victoria Nyanza, the second into the Highlands of Abyssinia. The third, which is at present of least