Physics of the Soil. 



pore space and that the smallest observed pore space also 

 falls below the smallest theoretical limit lor spherical 

 grains of a single size. 



Fio. 37. Showing the observed pore space of different kinds of soils and 

 sands and their relation to the theoretical pore space of spheres of 

 a simple diameter. 



135. Amount of Pore Space Determines Maximum Water 

 Capacity of Soil, The amount of water a soil may contain 

 when below the level of the ground water surface is meas- 

 ured by the pore space. So too in the case of heavy and 

 protracted rains the pore space determines the number of 

 inches of water which may enter the ground before it be- 

 comes so filled that surface drainage must carry away that 

 which is falling, and it will be readily understood that in 

 the clay soils, where the pore space is so high, very large 



