Texture of Soils. 



113 



to form a pore space between these two extremes, and Fig. 

 37 shows what the observed pore space is in soils, sand, 

 crushed rock and crushed glass. It will be observed that 





Fin. 36. Showing the closest packing of spherical grains, the element 

 of volume, and the direction of li 



are 90, 60 and 12Q< 



nes of flow when the face angles 

 (After Slichter.) 



the finest clay soils, and indeed the finest grained materials, 

 have the largest pore space. It will also be noted that the 

 largest observed pore space exceeds the largest theoretical 



