218 NORTH-EAST APEICA. powerful Britannia, Sudan is henceforth to enjoy full independence, and regulate its own affairs, without the undue interference of any foreign Government." At present the Mussulman states in this region of Sudan are entirely destitute of strateo-ical routes, although at first sight the country seems to be completely open to the Abyssinians occupying the plateaux. They could easily descend by their riverain valleys, but as they cannot long breathe a mephitic atmosphere, the climate of the lowlands is a far more formidable enemy to them than the natives ; such conquests as they do effect are transitory, and by the very force of circumstances are a^ain soon lost. On the other hand, if they are prevented by nature itself from seizing these lowlands, they would still be a great obstacle to invaders of Upper Nubia wishing to penetrate along the route over the fertile slopes to Massawah and the countries of the Mensas and Bogos. The Egyptians learnt to their cost the dangers of venturing on this route, exposed, as they were, to the attacks on their flanks from the Abyssinian warriors. Farther north, from Suakin to the Nile, the water in the wells is barely sufficient for the nomad tribes, and owing to this cause the operations of the British troops in this region were greatly impeded during the campaigns of 1884 and 1885. Pending the opening of the railway from Suakin to Berber begun in 1885, the plains of the Blue Nile and Atbara can be reached only by the three traditional northern routes — that which follows the Nile from cataract to cataract ; and those avoiding the groat curves of the Nile by running across the desert of Bayuda, between Debbeh and Khartum on the west; and through the Nubian wilderness between Korosko and Abu-Hamed on the east. These three routes were closed to the Egyptians by the late Mussulman insurrec- tion, and re-opened by the English under General "Wolseley in 1884-5. The Gumu, Berta, and Lega Mountains. Beyond the Abyssinian plateaux the East Sudanese provinces have also their isolated mountain masses, forming veritable archipelagos in the midst of the plain. Many of these lofty hills which are delineated on the maps as forming part of the orographic system of Abyssinia, are, in reality, separated from it by plains. Such are the Gumu Mountains, commanding to the east the valley in which the Abai, or Blue Nile, in its upper course completes its semicircular bend before reaching the plain. A few escarpments close to the river form, together with the projecting promontories of the opposite watershed, the last gorge of the Abyssinian Nile. Farther up the river, and near its confluence with the Jabus, stands an isolated rock, the Abu-Danab of the Arabs, the Tulu-Soghida of the Gallas, which is the "Mountain of Salt," whose abimdant resources have not yet been analysed by Europeans. Beyond this point to the south-west the Tumat and Jabus, two large affluents of the Blue Nile, skirt the eastern base of other mountains or of an ancient plateau, which running waters have completely furrowed in every direction. These are the Berta Mountains, famous for their gold washings, which determined the Egyptian invasion. A
