Principles of Wetting Soil 



331 



fastest ; namely, because the pores are largest and 

 offer less resistance to the flow. The truth of this 

 statement will be readily apprehended by studying 

 Fig. 83, which shows how greatly the diameter of the 



Fig. 82. Slow rate of lateral spread of water in soil. 



waterways in a soil is modified by the size and ar- 

 rangement of the soil grains. This being true, it is 

 plain that water should be moved most rapidly over 

 the coarsest soils, in order that unnecessary waste by 

 deep percolation may not take place. 



