6i8 W. H. TWENHOFEL AND F. T. THWAITES 



40r 40r 



35 [ 35 



20 h ^Hh ZOf 



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A B 



56 r HI 50r 



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70. 



65 

 60 

 55 

 50 

 45 

 40 

 35 

 30 

 25 

 20 



-I I k> 



I 23456763 10 



Fig, 2. — Mechanical analyses of characteristic sands (for description see 

 opposite page)o 



