The rivers of the country are for the most part mere torrents, which carry a heavy body of water after rains, but are often absolutely dry for several months in succession.

Water, however, is generally obtainable by digging wells in their beds; and the liquid procured in this way suffices, not only for the wants of man and beast, but also for a limited irrigation.
The Great Plateau which has been here described is bordered everywhere, except at its north-eastern and north-western corners, by low regions.
On the north the lowland is at first a mere narrow strip intervening between the Elburz range and the Caspian, a strip which has been already described in the account given of the Third Monarchy.

Where, however, the Caspian ends, its shore trending away to the northward, there succeeds to this mere strip of territory a broad and ample tract of sandy plain, extending from about the 54th to the 68th degree of east longitude--a distance of 760 miles--and reaching from the 36th to the 50th parallel of north latitude--a distance not much short of a thousand miles! This tract which comprises the modern Khanats of Khiva and Bokhara, together with a considerable piece of Southern Asiatic Russia, is for the most part a huge trackless desert, composed of loose sand, black or red, which the wind heaps up into hills.

Scarcely any region on the earth's surface is more desolate.

The boundless plain lies stretched before the traveller like an interminable sea, but dead, dull, and motionless.