EXERCISE A-23. TO STUDY THE FORMS OF SOIL 



MOISTURE. 



.^^ 



Equipment:* Balances; drying oven; soil auger; sample 



boxes. 



Method : With the soil auger secure 

 samples of soil at a depth of six, 

 eighteen, and thirty inches. Transfer 

 the samples at once to tight tin boxes 

 with lids. As soon as possible weigh 

 the boxes and contents. Remove the 

 lids and let the soil dry in the air for 

 one week, then weigh. Continue the 

 drying until constant weight is at- 

 tained. 



What does the loss in weight 

 Fig. 20. — Soil Sample- represent? Does this soil still contain 

 case Provided with any moisture? 



Place the samples in an oven with 

 the lids off the boxes and dry for two 

 days. Weigh and record the weights. 



* The balance shown in Exercise 7 or the one shown in Exercise 

 9 may be used. A one-burner gasoline or kerosene stove with a 

 small baking oven may be used. The flame should be regulated to kecj) 

 the temperature at about 105° C. or 212°-215° F. 



A soil auger may be purchased from an implement firm or it may be 

 constructed by a local blacksmith by welding a length (three feet) of 

 iron pipe onto the shank of a common 1^ or 1 2-inch wood auger. 

 Tin salve-boxes make very satisfactory soil containers. 



48 



Seamless Tin Boxes 

 for Use in Collecting 

 Field Samples. 



