528 



STATE BOARD OF AGRICULTURE. 



EFFECT OF TEMPERATURE ON THE PERCOLATION OF WATER 



IN SOILS. 



As shown in table 1, the surface tension and viscosity of water decrease 

 with rise in temperature. From these data it is to be expected that the 

 rate of flow of water in soils should increase in direct ratio with tem- 

 perature. In summer time the rate of percolation should be greater than 

 in winter, before freezing. 



FIG. 7. APPARATUS FOR DETERMINING THE EFFECT OF TEMPERATURE ON THE 



RATE OF FLOW OF WATER IN SOILS. ALSO THE EFFECT OF TEMPERATURE ON 



THE WATER-HOLDING CAPACITY OF SOILS. 



The only and often cited experiment upon this subject is that of King, 

 in which he attempted to study the influence of temperature upon the 

 rate of percolation of water through a sandy soil only. King found that 

 a rise of temperature of from 9° to 24° C. increased the rate of percola- 

 tion 50 per cent. Briggs, through calculation, came to the conclu- 

 sion that these results are precisely those which might have been pre- 

 dicted from the known diminution of viscosity of Avater with rise in tem- 

 perature. 



Since the subject is of considerable importance and Jias received really 

 no study, a research of it was undertaken. The method of procedure con- 

 sisted in keeping a column of soil at a definite temperature and allowing 



