having from 3,000 to nearly 10,000 feet of elevation. The green and fertile region which is thus interposed between the 'highland' and 'lowland' deserts,[1] participates, curiously enough, in both characters. Where the belt of sand is intersected by the valley of the Nile, no marked change of elevation occurs; and the continuous low desert is merely interrupted by a few miles of green and cultivable surface, the whole of which is just as smooth and as flat as the waste on either side of it. But it is otherwise at the more eastern interruption. Then the verdant and productive country divides itself into two tracts, running parallel to each other, of which the western presents features, not unlike those that characterize the Nile valley, but on a far larger scale; while the eastern is a lofty mountain region, consisting for the most part of five or six parallel ranges, and mounting in many places far above the level of perpetual snow.
"It is with the western or plain tract that we are here concerned. Between the outer limits of the Syro-Arabian desert and the foot of the great mountain range of Kurdistan and Luristan intervenes a territory long famous in the world's history, and the chief site of three out of the five empires of whose history, geography, and antiquities, it is proposed to treat in the present volumes. Known to the Jews as Aram-Naharaim, or 'Syria of the two rivers'; to the Greeks and Romans as Mesopotamia, or 'the between-river country'; to the Arabs as Al-Jezireh, or 'the island', this district has always taken its name from the streams which constitute its most striking feature, and to which, in fact, it owes its existence. If it were not for the two great rivers-the Tigris and Euphrates-with their tributaries, the more northern part of the Mesopotamian lowland would in no respect differ from the Syro-Arabian desert on which it adjoins, and which, in latitude, elevation,and general geological character, it exactly resembles. Towards the south the importance of the rivers is still greater; for of Lower Mesopotamia it may be said, with more truth than of Egypt,[2] that it is 'an acquired land,' the actual 'gift' of the two streams which wash it on either side; being as it is, entirely a recent formation-a deposit which the streams have made in the shallow waters of a gulf into which they have flowed for many ages.[3]
