112 



Physics of the Soil. 



the upper part of Fig. 34, then the pore space must 

 be as large as 47.64 per cent. In the first case the water 

 capacity of such a soil with the pores entirely filled would 



FIG. 35. Showing the closest packing of spherical soil grains, the ele- 

 ment of volume and the direction of lines of flow. Pace angles 60 

 and 120. (After Slichter.) 



be 3.114 acre-inches per acre-foot and with the second ar- 

 rangement the maximum water capacity would be 5.7168 

 acre-inches per acre-foot. 



Neither of these arrangements would be likely to occur 

 throughout a mass, and hence the general tendency will be 



