Page:Mongolia, the Tangut country, and the solitudes of northern Tibet vol 2 (1876).djvu/74

54 The Tingeri have the appearance of innumerable hillocks, lying close together, without any regularity. They are from fifty to sixty feet, rarely one hundred feet high, composed of fine yellow sand on a hard clay subsoil, with occasional bare patches of clay. A few rare tufts of mat grass (Psamma villosa) and field mugwort are here and there scattered over these clayey areas, now and then protruding through the sand; or more rarely some shrub of the leguminous order makes its appearance. But such scanty vegetation makes no impression on the death-like character of these deserts, the only living creatures in which are the kites and small black marmot. The loose sand, heated by a burning sun, is constantly carried by the wind from one hillock to another, lying in ridges or furrows between the mounds. These greatly impede the progress of the caravan, especially of the pack-animals, which have to climb from one hillock to another, sinking deep at every step in the loose soil. There is no track here of any kind; nothing but dried camels' dung, and an occasional skeleton of one of these beasts serve to show you the direction you must take. You generally steer by the sun. It is terrible to be caught in such places in a whirlwind. The summits of the sandy hillocks at first appear as though enveloped in smoke; the air becomes darkened with clouds of sand, which obscure the sun. The best time for crossing these hillocks is after a rain-fall, when the hardened soil supports the weight of the camels and the air remains clear.