EXPERIMENTS 



i. Pulverized Rock and Soil. — Pulverize in an iron mortar, 

 pieces of feldspar, mica, granite, and limestone. Examine each 

 with a lens. Finally mix all of the pulverized material, and com- 

 pare the mixture with samples of soil. 



2. Weight of Soils. — Weigh a cubic foot of air-dried sand, clay, 

 and peat. For this purpose use a box holding % of a cubic foot of 

 soil. Do not compact the soil. 



3. Form of Soil Particles. — Examine under a microscope soil 

 particles and distinguish the various grades of sand and silt. Ob- 

 serve the form of the soil particles and make drawings of them. 



4. Separation of Soil Particles. — By means of sieves, with holes, 

 J, )4, and % mm. in diameter, separate these three grades of parti- 

 cles as described in Section 10. To what type does the soil 

 examined belong? 



5. Capillarity. — Place small glass tubes of various sizes in a 

 vessel of water and note the height to which water rises by capil- 

 larity. 



6. Capillarity of Soils. — Fill glass tubes 2 inches in diameter 

 with clay and fine sand, respectively. Support the tubes so that 

 one end will touch the water in a cylinder. Observe the rate and 

 height to which the capillar}- water rises, making daily measure- 

 ments for a week. 



7. Hydroscopic Moisture. — Places grams of air-dried soil on a 

 watch-glass, in a water-oven, and after two hours reweigh and de- 

 termine the loss of weight. Calculate the per cent, of hydroscopic 

 moisture. 



8. Influence of Cultivation on Soil Water. — Fill four boxes, each 

 a foot square and a foot deep, with air-dried loam soil. Weigh the 

 boxes and soil used. Each box is to be treated separately as fol- 

 lows : Measure one-half gallon of water into a watering-pot. Allow 

 the water from the watering-pot to flow on the soil, regulating the 

 flow so that it is all absorbed. The soil should be saturated, but 



