Bui. 373, U. S. Dept. of Agriculture. 
Plate VI. 
. 
Jit 
^-.•-v- 
" 
I 
Hi 
3* 
,*§s* 
... 
Fig. 1.— Spreading Sand Cushion. 
OPRRE 9225 
Fig. 2.— Rolling Sand Cushion. 
EXPERIMENTAL ROAD AT CHEVY CHASE, MD. 
