The course of the Khabour below Koukab is tortuous; but its general direction is S.S.W.The entire length of the stream is certainly not less than 200 miles.
The country between the "Mons Masius" and the Sinjar range is an undulating plain, from 60 to 70 miles in width, almost as devoid of geographical features as the alluvium of Babylonia.

From a height the whole appears to be a dead level: but the traveller finds, on descending, that the surface, like that of the American prairies and the Roman Campagna, really rises and falls in a manner which offers a decided contrast to the alluvial flats nearer the sea.

Great portions of the tract are very deficient in water.

Only small streams descend from the Sinjar range, and these are soon absorbed by the thirsty soil; so that except in the immediate vicinity of the hills north and south, and along the courses of the Khabour, the Belik, and their affluents, there is little natural fertility, and cultivation is difficult.

The soil too is often gypsiferous, and its salt and nitrous exudations destroy vegetation; while at the same time the streams and springs are from the same cause for the most part brackish and unpalatable.