1899.] Introduction. xxv 
it must have been the seat of an advanced civilization. Among the 
peculiar features of the tract of country which comprises that desert 
and the adjoining belt of cultivation are the numerous rivers which 
come from the valleys of the Karakorum and Kuenluen Ranges, and 
traverse its surface to their final junction with the Tarim river. 
In the present day it is only the two largest of these rivers, the 
Yurung Qash on which Khotan lies, and the Qara Qash on which 
the homonymous town lies, which, uniting north of Khotan, reach 
that termination. The smaller rivers, some of which may have 
been tributaries of the two large ones, after emerging from the 
valleys, now soon lose themselves in the sandy desert. “ These 
rivers large and small, are the seats of the fixed population and 
the entire productive industry of the country.” “Numerous canals 
are drawn off from them to the lands on each side, and thus 
convert considerable tracts of what would be otherwise desert-waste 
into fertile and populous settlements.” At present the extent of these 
settlements is very limited, but formerly—many centuries ago—they 
extended much further into the interior, probably some 30 to 50 miles 
beyond the present borders of the sandy desert. The climate of the 
country is notable for “ the extreme dryness of its atmosphere at all times 
and the trifling amount of its rainfall.” As a consequence “the soil 
everywhere is characterised by its aridity and barrenness, and is more or 
less highly charged with salines, which retain sufficient moisture to form, 
in the desert, mud bogs and marshes on which grow coarse reeds and 
dwarf tamarisks.” In these circumstances it is only by careful irriga¬ 
tion that the area of cultivation can be preserved and the encroach¬ 
ments of the moving sands of the desert prevented. The appearance 
and action of these moving sands has thus been described by Dr. 
Bellew : “ During the spring and summer months a north or north¬ 
west wind prevails, blowing with considerable force and persistence for 
many days consecutively. As it sweeps over the plain, it raises the 
impalpable dust on its surface, and obscures the air by a dense haze 
resembling in darkness a November fog in London; but it drives the 
heavier particles of sand before it, and on the subsidence of the wind, 
they are left on the plain in the form of ripples, like those on the sandy 
beach washed by an ebbing current.” In course of time, there is formed 
“ a perfect sea of loose sand, advancing in regular wave lines from 
north-west to south-east. The sand dunes are mostly from ten to 
twenty feet high, but some are seen like little hills, fully a hundred 
feet high, and in some spots higher. They cover the plain, of which 
the hard clay is seen between their rows, with numberless chains of 
two or three or more together in a line, and follow in successive rows, 
J. i. 4 
