36 ATMOSPHERIC DUST. 



Table XXIT. Mechanical Composition of Volcanic Dust. 



Length of 



diameter In 



mm. 



90 



From a coarse 



layer, McPherson 



CO., Kans. 



From McPherson 

 CO., Kans, 



93 



From 

 Golden, Colo. 



93 



From SDOW In 

 Norway. 



16-8 

 8— t 

 4-2 

 2—1 



i- 



-i 



1_ 



8 



-iV 



1 1 



i^ 



-irV 



uV- 



-tI^ 



\l~S~ 



~?Tr 



tr. 



.5 



4G.0 



52.0 



1.0 



> 



28 

 24 

 33 

 11 

 1 



.5 



.8 



37.4 



36.4 



21.7 



1.6 





tr. 

 10.0 

 42.0 

 42.0 



5.2 



I 



Table XXII. (Continued.) 



From 



Furnas cc.Nebr. 



From Nevada. 



96 



From 

 Orleans, Nebr. 



Average. 



.2 t 

 .1 . 



7.0 

 51.0 

 37.2 



3.4 

 .2 



^ 



