LYNDE-DUPRE 



CAPILLARY LIFT OF SOILS 



127 



Results 



The results obtained were as follows: — 



TABLE 5. 



Giving the capillary lift produced by the soil constituent, clay, under pressures 

 equal to, greater than and less than, one atmosphere. 



Conclusions. These results indicate: 



(1) that the capillary lift observed is limited by the pressura of 

 the atmosphere; 



(2) that therefore the maximum lift observed by this method 

 under a pressure of one atmosphere cannot exceed 10 meters or 34 feet. 



Part IV. 



Can soils lift water to a greater height than 10 meters or 34: feet? 



By the method described above the maximum observed capillary 

 lift has been increased from 10* 17 feet to 30 «1 feet. This is nearly 

 the height to which water is raised by a pressui-e of one atmosphere. 

 This brings up the question — "Can soils lift water to heights greater 

 than 10 meters or 34 feet?" This question can be answered only by 

 further experiment. 



There are two ways, at least, in which water might be raised by 

 soils to heights greater than 10 meters, namely, by surface tension, 

 in conjunction with the stability of water under tension, and by osmosis. 



Surface tension and the stability of water under tension. 



The lowest calculated capillary lift of clay is 2118 cms. or 70 feet 

 and the calculated lift is greater the finer the grains of the clay. If 

 then water can be raised by tensile stress, as seems probable from the 



