LJEE SAND. 



29 



Table XVII. Mechanical Composition of Sand taken in the Lee of Drifting Sand 

 south of Moline, Ills. 



T^eDgth of 



diameter in 



mm. 



Average of 

 the dune sand. 



10 feet in front 

 of the dune. 



100 feet in front 

 of the dune. 



73 



160 feet in front 

 of the dune. 



16-8 

 8—4 

 4-2 

 2-1 



1-^ 



1 _ 



_1 



4 



_1_ 

 8 



.J 

 IB 



. 1 

 "3^ 



■5^ rV 



1 _ 

 (i4 



1 _ 



TO 



_1 



12 3 



■ 1 

 "SXiT 



2.6 



58.5 



28.8 



9.0 



.4 



^ 



1.9 

 51.8 

 32.0 

 13.7 



^ 



TaUe XVIII. Mechanical Composition of Sand taken in tlie Lee of Drifting Fields 



in Nortli Dakota. 





Average of 

 drift sand. 



74 



75 



Length of 



diameter in 



mm. 



DuBt In a house 



4 ml. from a 



drifting field. 



Dust In a school- 

 house, 4 ml. from 

 a drifting field. 



16—8 









8-4 









4—2 









2—1 



tr. • 





.1 



1-i 



9.2 1 



.5 



.4; 



i-i 



20.3 h 



1.0 



.3 , 



i-i 



58.9 k 



5.0 



4.6 1 



1-tV 



9.9 1^ 



19.8 1 



22.8 1 



1'W~'^J 



1.3 



58.9 H 



60.9 ■■ 



1 1 



32 64 



.3 



12.7 1 



9.4 P 



"ir4 12« 





1.3 



.7 



T28 3 56 





tr. 



tr. . 



