PRACTICE X 



DETERMINATION OF SHRINKAGE IN SOILS 



Two students may work together. 



Weigh out in a small soil pan 200 g. of sand or sandy loam, 

 gray silt or gray silt loam, brown silt loam, clay or clay loam, 

 and peat. 



The soil with the quantity of water representing maximum 

 tenacity in Practice IX may be used here if put into the pan 

 while it is still moist. 



Mix each sample thoroughly by hand with the right quantity 

 of water to bring about maximum adhesiveness. 



Place cheesecloth in the bottom of a pan 3 inches, or 76 mm., 

 square and ^ inch deep. Pack in the soil and scrape it off even 

 with the top of pan. Take out the block of soil on cheesecloth 

 and dry at room temperature for 'a day or two before placing in 

 the oven at 100 C. for twenty-four hours. 



Measure and record the size of the block of dry soil. Cal- 

 culate the shrinkage and express in per cent of the original area 

 of the block of wet soil. 



99 



