EXPERIMENTS 



265 



follows : One with air dry sand, one with clay, one with loam, and 

 one with sand containing 5 per cent, of fine dry manure. Deter- 

 mine the hydroscopic moisture of each sample. Weigh the boxes 

 after adding the soils which should be moderately compacted. To 

 each add the same amount of water slowly from a sprinkling pot, 

 carefully measuring the water used. The soil should be well 

 moistened, but not supersaturated. Each box is to receive shal- 

 low surface cultivation, using for the purpose a gardener's small 

 tool. Leave the boxes exposed to the sun or in a moderately warm 

 room. At the end of two or three days take a sample of soil from 

 the center of each box at a depth of four inches and determine the 

 moisture content as directed in Experiment No. i. Note the differ- 

 ences in moisture content. Weigh the boxes. Take the tempera- 

 ture of the soil in each box. 



Experiment No. 6. 

 Weight of Soils. 



Determine the cubic contents of a box about 4 inches square. 

 Weigh the box. Determine its weight when filled, not compacted, 

 w T ith air dry sand, with clay, with loam and with peaty soil. Com- 

 pute the weight per cubic foot of each soil. 



Fig. 39. Determining the Weight of Soils. 



Experiment No. 7. 



Influence of Color Upon the Temperature of Soils. 



Expose to the sun's rays, dry clay, dry sand, and moist and dry 



peat. After two hours exposure take the temperature of each. 



The bulb of the thermometer should just be covered with the soil. 



All of the observations should be made under uniform conditions. 



