570 



STATE BOARD OF AGRICULTURE. 



creased in an arithmetic progression. The results of the soils, therefore, 

 could be mathematically expressed by the equation D = A*R"~^, where 

 D is the depression of the freezing point, A the first depression, R the 

 ratio of any depression (except the first) to the preceding one, and n the 

 number of the depression. According to this formula, if the lowering of 

 the freezing point of a soil was experimentally determined at two dif- 

 ferent moisture contents, it could be calculated for any other moisture 

 content. 



This phase of the original investigation was also restudied in the 

 present work. As in the former case the procedure consisted of prepar- 

 ing a large number of samples of soil at different moisture contents, 

 allowing them to stand in room temperature over night, care being taken 

 to prevent evaporation, and then determining their lowering of the freez- 

 ing point in the usual way. The quantity of moisture added was in- 

 creased by equal amounts and the sample was prepared as rapidly as 

 possible so that there would be the least possible loss of water through 

 evaporation. The results obtained for quartz sand and for a few types 

 of soil are represented in Tables 4 and 5, respectively. 



Table 4- Lowering of the Freezing Point of Quartz Sand 

 at Various Moisture Contents. ■ 



