ABSTRACT
I t is necessary to distinguish five principal regions. The first is the Ethiopian-Kaffa plateau, which includes the northern plateau now part of Er it rea and the whole ofTigrai, Aml)ara, Gojam, Shoa, and JimmaKaffa; that is, the historical region of Abyssinia and of the Sidama kingdoms. It is a vast irregular tableland of volcanic reefs having a general elevation of 6,500 feet in which terrace rises above terrace to form high wide plateaux. It is clearly defined on the east by the steep edges of a mountain wall which is the western edge of the great East African rift, having an average altitude of 8,000 feet. This acts as a vast retaining wall which drops abruptly into the sea at the Gulf of Arafali or into the low, arid, and hot Dankali depression. A parallel rift runs from Lake Tana along the Blue Nile canyon to the southern lakes. The Ethiopian highland is tilted towards the west and descends more or less regularly in vast terraces towards the plains of the Nilotic Sudan, but in the north-west and south-west there is a rapid descent of several thousand feet. The great line of the escarpment overlooking the Red Sea to the east and the Sudan plains to the west has acted as a barrier protecting the inhabitants against the migratory movements of other peoples. Towards the south-east beyond the Abay, access is less difficult,
the altitude diminishes, the valleys grow more numerous and give an individuality to smaller massifs which is reflected in the history and social life of their inhabitants. Deep ravines divide this great massif into many subordinate plateaux, above which as bases, rise several mountain chains.
