62 



WAVES OF SAND AND SNOW 



a sandy plain of a dirty brown colour. West of 

 the canal, on the contrary, the sand was of a 

 bright yellow colour, like that of ripe wheat. The 

 prevailing drift of the sand is from the west. The 

 canal intercepts much of it, so that the level of 

 the sand near by on the east is now being lowered. 

 The roots of bushes have consequently been 

 exposed, and the general tone of the ground- 

 colour is darkened by admixture of decayed 

 vegetable matter. 



Fig. 2. 



Farther east we began to ascend a sand-buried 

 tract, the individual sandhills being at first round- 

 topped and of indefinite shape. Later I saw on 

 the north of our route large sand-dunes in con- 

 secutive parallel ridges. A group of four had 

 quite the appearance of a train of waves. The 

 long, gentle slope was on the west, and there 

 was a steeper slope on the east, but the wind 

 now daily prevalent was opposite to that which 

 must have produced this form. The present 

 moderate breeze was blowing up the steep east 

 face, eddying on the west of its summit, where 



