PRACTICE XXIV 



DETERMINATION OF THE RATE OF PERCOLATION OF WATER 

 THROUGH SOILS 



Use sand or sandy loam, gray silt or gray silt loam, and brown 

 silt loam. 



Fill the percolator tubes, without compacting, to within one 

 inch of the intake and overflow tubes. Place a half -inch layer 

 of coarse sand on top of soil to prevent disturbance of the soil 

 by the flowing water. 



Connect the tubes as in Fig. 7. Attach one side to the water 

 supply ; the other should lead to the waste pipe or sink, for tak- 

 ing off the overflow. Allow the water to flow over the surface 

 of the soil just fast enough to keep it constantly flooded. Place 

 flasks under the percolator tubes to catch the drainage water. 



Note the time when the water is turned on and also when 

 drainage begins. 



When the flow becomes constant, measure the quantity of 

 water draining from the soil in 30 minutes. 



Repeat with the same soils in the same way, but compact them 

 in the usual manner. 



What application of this experiment do we see in farm 

 practice ? 



From this experiment would it be advisable to plow deep ? 



What objection to a sandy soil does this experiment show ? 



REFERENCES. 



" Soils," Lyon and Fippin, pp. 141, 166-169, and 191-194. 



"The Soil," Hall, pp. 70 and 75-79. 



"Physical Properties of Soil," Warington, pp. 85-91. 



"The Soil," King, pp. 170-173. 



" Soils," Hilgard, pp. 221-226. 



50 



