The other arm of the bifurcation, situated farther south, and beginning at the Terek-tau, is double; it consists of the Alai and Trans-Alai ranges, continued westwards in the Karateghin, Zarafshan, Hissar and Turkestan ranges, though orographically the Trans-Alai ought probably to be described as the border-ridge of the Pamir plateau.
After graduating as a staff officer at St Petersburg he was sent to Turkestan in 1868 and, with the exception of an interval of two years, during which he was on the staff of the grand duke Michael in the Caucasus, remained in Central Asia until 1877.
Having long suffered from a terrible disease, he died in 1773, bequeathing to his son Timur a dominion which embraced not only Afghanistan to its utmost limits, but the Punjab, Kashmir and Turkestan to the Oxus, with Sind, Baluchistan and Khorasan as tributary governments.
From the East Turkestan lowlands on the north the ascent is very steep, and the passes across both sets of ranges lie at great altitudes; for example, the pass of Sanju-davan in the lower range is 16,325 ft.
The portion of Asia which lies between the Arctic Ocean and the mountainous belt bounding Manchuria, Mongolia and Turkestan Siberia.
The highlands which shut off the Turkestan provinces from Southern Afghanistan have afforded the best opportunities for geological investigation, and as might be expected from their geographical position, the general result of the examination of exposed sections leads to the identification of geological affinity with Himalayan, Indian and Persian regions.
But although the Mahommedan religion from the very commencement sustained checks, it nevertheless made its weight felt upon the independent states of Turkestan to the north and east, and thus acquired a steadily growing influence.
Following Prjevalsky the Russian explorers, Pevtsov and Roborovski, in 1889-1890 (and again in 1894), added greatly to our knowledge of the topography of western Chinese Turkestan and the northern borders of Tibet; all these Russian expeditions being conducted on scientific principles and yielding results of the highest value.
The Taranchis from East Turkestan represent about 40 of the population; about 40,000 of them left Kulja when the Russian troops evacuated the territory, and the Chinese government sent some 8000 families from different towns of Kashgaria to take their place.
Yet Tsaidam is geographically but a northern extension of the great Tibetan plateau, and in most of its essential physical features it is more closely allied to the Chang-t'ang of the south than to the great sandy depressions of Chinese Turkestan or Mongolia on the north.