232 THE DESERT OF LOP.
south-south-west and inclosed between ridges of greenstone, 3 to 6 m. high, and often forming perpendicular sides to the torrent. This however soon came to an end, and we once more emerged into the open country.
The reason I selected this route was that one of my men had by the purest chance hit upon a spring surrounded by vegetation, an oasis in fact, and so well concealed by the lie of the ground that Abdu Rehim, my hunter guide from Singer, had never observed it. No matter from what direction this little oasis is approached, its presence cannot be perceived until you get quite close upon it. On the other hand Abdu Rehim pointed out to me another spring, lying south-west of Altmisch-bulak, and showing its yellow kamisch-fields a little way off. It was however at that time dry; in fact it is only in seasons of good rain and snow-fall that it does yield water.
In point of area the newly discovered oasis was barely one-tenth of that of Altmisch-bulak, and its vegetation was less abundant and less luxuriant. The kamisch was thinner, the tamarisk-mounds drier, but the bushes had thick, strong sterns. The surface fell away in every direction except to the north, where the barren gravelly ground approached close up to the vegetation of the oasis. On every other side there was a steep edge overhanging the barren surface a couple of meters below. As the vicinity was thickly set with small hills, the oasis was not perceived until we were quite close upon it.
Fig. 144. VERTICAL SECTION FROM S TO N THROUGH THE NEWLY DISCOVERED OASIS.
Under the eastern edge of the oasis there is a distinctly eroded torrent 3 to 4 m. broad and a couple of meters deep. The saliferous water gushed out of the soft earthy face of the right side of the torrent in several springs, one of them one meter above the bottom of the gully. This was at that time filled with a long strip of ice, about a hundred meters long; and from its lower end issued a rivulet, which, still farther down, formed another similar strip of ice. The upper ice-sheet was slushy and soft as snow to the depth of two or three centimeters; though in a sheltered bend it was still firm and bright as glass, and about a foot thick. Vigorous kamisch was growing in the bottom of the gully, and it too helped to preserve the ice, notwithstanding that the temperature of the air was then as high as 15° C. The water, taken at the point where it issued into daylight, had a temp. of 0.7; its sp. gr. was I.0232.
South of the oasis there was a depression with schor soil, and into it the water gathered from the springs. Several tamarisk-mounds likewise pointed to this hollow being a water-reservoir. After that we came to a whole series of greenstone hills and ridges, which, sloping towards the south-east, were cut at right angles by most of the eroded torrents, they too running in this locality towards the southeast. When the hard rock came to an end, the last torrent widened out to a broad passage-way between the big blocks of clay, but soon afterwards became lost in the soft gravelly saj; and this again in its turn speedily gave place to rough, lumpy
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