54 SAND-DRIFTS. 



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 {Psamnia villosd) 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 legumin- 

 ous 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 gene- 

 rally 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. 



