30 



LEE PAXl). 



sand to forty-one in the lee-sand. The series taken in 

 front of the sand drift at Lindsborg changes more rapid- 

 ily, so that only fifty feet away sixty-five parts in a 

 hundred consist of very fine sand (Tab. XIX). 



The dune at this place was mw-h lower than the other, 

 and this partly accounts for the more rapid settling- of 

 the fine sand, which here had a much shorter distance to 



Fig. XIX. Mechanical Composition of some Sand tal<en in tlie Lee of Drifting Sand 



near Lindsborg, Kans. 





Dune sand. 



68 



{ 69 



TO 



Length of 



diaiaeter in 



mm. 



Lee drift sand. 



Sand from 10 feet 



in front of lee 



drift. 



Sand from 50 feet 



in front of lee 



drift. 



16—8 







f 





8—4 











4—2 











2-1 











1-i 



3.1 1 



3.2 



_ i""i 



. 1 





4-i 



23.3 ■ 



18.7 1 



y.3 



T..T 





i-i 



69.1 ■■ 



71.2 ^1 



60..3 H 



14.-± 



V 



"5 T¥ 



3 9 



5.0 P 



20.5 1 



65.2 



1 1 

 16 3T 



.4 



3.9 1 



5.9 1 



16.3 



1 1 





.1 



.3 ' 



.8 



64 1*8 





TTS ^ 















fall. The samples from Xorth Datota were taken in 

 buildings and are not strictly comparable to the other, 

 but the small amount of fine sand and even of very fine 

 sand which they contain, indicates that most of the for- 

 mer grade, at any rate, had already settled (Tab, XTIII). 

 As the houses were about four miles away from the 

 place of active drifting, it seems safe to infer that this 



