42 



THE PHYSICAL PROPERTIES OP SOILS 



SIXTH EXERCISE 



I. FLOW OF AIR THROUGH LABORATORY 



STOCK SOILS 



Fill six aspirator tubes (T) with soils from the 

 bins as follows : 



Tube No. I — Sand. 



Tube No. 2 — Mixture, three parts sand, one 



part organic matter. 

 Tube No. 3 — Loam or silt. 

 Tube No. 4— Muck. 

 Tube No. 5 — Clay. 

 Tube No. 6 — Mixture, three parts clay, one 



part organic matter. 



BOTTLE ASPIRATOR 

 Used in comparing the rate of flow of air through diflferent soils 



Compact each tube on the iron compactor by drop- 

 ping the weight four times from the 6-inch mark after 

 each measure of soil. Connect tube No. i to the as- 



