104 



RELATIONS OF SOIL TO WATER 



the weather had gained much water, but clearly from above. 

 In this case the water level was about 30 ft. below the 

 surface. 



TABLE XVII 



WATER PER IOO DRY SOIL, COVERED AND UNCOVERED, AT 

 DIFFERENT DATES (KING) 



A comparison of the results given by the deepest and 

 shallowest of the Rothamsted drain-gauges also affords an 

 example of the small influence of capillary action in bringing 

 water to the surface. Each drain-gauge consists of a rect- 

 angular mass of heavy loam, with flints, of the area of 

 iirijir f an acre; the depth of the shallowest mass of soil 

 is 20 inches, of the deepest 60 inches. The deepest soil has 

 thus a subsoil of 40 inches to draw upon, which is wanting 

 in the case of the shallowest soil. On an average of twenty- 

 four years the annual evaporation from the deepest soil has 

 only exceeded that from the shallowest by 0-6 inch ; this 

 probably represents the quantity of water brought to the 

 surface from below a depth of 20 inches. 



According to various published experiments the presence of 

 certain salts increases the rapidity of movement in capillary 



