The name "Central Asia" correctly describes, in a geographical sense, the heart of that continent. It is separated from the river- system of the Aral and Caspian Seas, on the west, by almost impassable mountain-ranges; from the affluent of the Indus and Ganges, on the south, by the chain of the Küenlün, the rival of the Himalayas and from the rivers of China to the eastward, by the great Desert of Gobi. A line drawn from Constantinople to Peking and another from the latitude of Cape Comorin to that of the Polar Sea, bisecting the former line, would very nearly indicate the central portion of the region, as also the continent.
Here-partly, perhaps, on account of its remote and nearly inaccessible situation and also partly from concurrent traditions—many ethnologists have placed the original cradle of the Aryan race. India was undoubtedly colonized by tribes descending from the high plateaus to the northward and the legends of the earlier Aryan inhabitants of Europe have been traced backward, step, by step, until they lose themselves among the labyrinths of mountains from which descend the Oxus and the Jaxartes. The remarkable physical features of the region must have impressed themselves upon even the primitive inhabitants. The three enclosing mountain- chains, which form almost three sides of a square, rise to such an elevation that few of their passes are less than 18,000 feet above the sea. Above the western wall lies the tableland of Pamer or Pamir, called by the natives Bam-i-doonia or "Roof of the World". The fertile lands beyond those upper realms of rock and snow and scanty summer pastures, can only be reached after many days of dangerous travel, where beasts of burden find no food, where water is rarely to be had and where, even in summer, hurricanes of intense cold threaten to destroy of life in a few hours.