THE UNEXPLORED SALT DESERT OF LOP 251
At Koshalangza I gave them another chance to go back, but they swore that they were not afraid.
For four weary days we stumbled northward across the interminable salt plain of the old lake-bed. An ordinary frozen plowed field would have seemed like a macadam road in comparison. Imagine the choppiest sort of sea with white-caps a foot or two high, and freeze it solid. When we camped in what we hoped was a soft spot, and tried to drive in the iron tent-pegs, most of them bent double. We had to use an axe to hew down hummocks of rock salt a foot high before we could get places smooth enough for sleeping. Each night when we pulled off our soft-soled boots, —the only kind in which we could keep warm, —we realized what effect the bastinado must produce. The slowness of our stumbling progress, the boundlessness of the sea-like horizon, the bitter morning wind, and the uncertainty as to when we should find something different made us feel that the old lake-bed must be endless.
The roughness of the salt plain may be explained as follows : During the long-continued process of drying up, the ancient lake of Lop deposited an unknown thickness of almost pure rock salt. When the salt finally became dry, it split into pentagons from five to twelve feet in diameter, the process being similar to that which gives rise to mud-cracks when a mud-puddle dries up, or to basaltic columns when lava cools. The wind, or some other agency, apparently deposited dust in the cracks; when rain or snow fell, the moisture brought up new salt from below; and thus the cracks were solidly filled. When next the plain became dry, the pentagons appeared again. This time the amount of mate-
IIIFカラー高解像度
