DOWN THE KHOTAN-DARIA 641 
where the channel is broad and level, there are no pools, 
and the trenches made by the last season’s floods are 
scarcely discernible; but where it is narrow, there exist 
numerous pools, and the trenches made by the current are 
plainly marked in serpentine curves. I also observed that 
the forest was appreciably thinner on the right bank than 
on the left ; in fact, in many parts it ceased altogether, its 
place being taken by bare sand-dunes. Close under the 
western bank the river-bed itself was occasionally over- 
grown with grass ; but that was never the case along the 
right-hand side of the river. Everything tended to show, 
that the current flows stronger on the right or eastern side 
than it does on the left or western. But in any case, the 
movement of the current towards the east takes place at 
such a slow rate, that the afforestation of its banks is 
enabled to keep pace with it. A few isolated poplars, like 
those near which we made our signal fire on May 3rd, still 
maintained a precarious existence on the west side of the 
stream ; but they are doomed to perish. 
At six o’clock we were still riding along the river-bed ; 
Islam Bai had gone on in advance to seek out a convenient 
spot for camping on ; when all at once the whole of the 
west became enshrouded In a dark yellowish-grey cloud. 
At first it looked like a low wall ; then it rapidly mounted 
higher, till it reached half-way to the zenith ; and then the 
next moment it was directly over our heads. The sun 
faded to a pale lemon disc ; then totally vanished. A 
distant murmur arose along the border of the forest. It 
approached rapidly nearer. We heard the twigs and 
branches snapping off with a louder and louder echo. 
Towards the north-west the forest was enveloped in haze. 
Columns of sand and dust came spinning across the river- 
bed like theatrical wing-scenes moving on invisible rollers, 
alternately shooting on In advance of each other ; and in 
a moment the forest was entirely blotted out. The first 
outfliers of the storm burst upon us ; the black buran 
followed close at their heels, striking us with terrific 
violence, swallowing us up in its Impenetrable clouds of 
dust. The sand was swept along in eddying sheets, 
I. - 4 1 
