Ground Water Surface. 



257 



In the soils and clay 3 the pore space is even larger than 

 it is in the sands and this too may be filled with water but 

 here the texture is usually so close that a well sunk in such 



e sv 'oa t 



v\% 



V* 



^> 



I 



^nteg&& 



:^y//n,^<Ai 



FIG 89. Contour map of the ground water surface under the field of 



Fig. 88. 



material fills with water so slowly that they cannot serve 

 as sources of water supply. 



Even in the hard crystalline rock, like marble and 



