A. Wade—Formation of ‘Dreikante’. 395 
opposite to the point from which the wind usually comes should be 
just as pointed as the other. It is inconceivable that the deflected 
currents of sand-grains would keep so closely to the pebble from 
end to end. One would expect a pointed front and a more or less 
unworn end. This, however, does not occur. It seems therefore 
that this explanation is not quite satisfactory in its nature. 
During 1909 I spent a good many months on the Eastern Desert of 
Egypt, and it occurred to me to make a careful examination of the 
dreikante, which are so abundant in the stony desert tract which 
stretches between the Red Sea Hills and the coast. 
a= 
ae 
aes 
Fic. 2. Types of ridge-curves in dreikante shown in plan. The type figured in 
No. 3 is often so modified at each extremity by branching that instead of having 
two upper faces the dreikante has four. 
The dreikante are usually formed from quartz pebbles derived from 
the Nubian Sandstone, but flints from the Eocene, granites and 
porphyries from the mountains, and some dolomitic limestone also 
furnish supplies. The most perfect examples are produced from the 
quartz pebbles and from a fine-grained red felsite. 
The locality is almost an ideal one for such an investigation, since 
the wind blows almost invariably from one quarter (north, or a little 
west of north). At the outset I was struck by the fact that the long 
axes of the dreikante were not usually set in the direction of the 
prevailing wind. This led me to work carefully and systematically 
over a limited area. I marked out a portion of fairly level desert, 
