CAPILLARY MOVEMENT OF SOIL MOISTURE. 
51 
The values of y 1 are calculated from this formula and tabulated in 
Table 37. 
The differences between y x and y are also tabulated as y,. y 2 = 
9 1.0 I.I 1.2 1.3 1.4 /.5 1.0 1.7 1.8 
O 5 10 15 20 25 „ 30 35 40 45 
Days (x) 
Fig. 9. — Method of developing formulae for movement of moisture in flume 31. 
The values of y 2 . log y 23 log y\ a? 5 log a?, and y are plotted against 
each other as shown in figure 9 A, but none of these curves is a 
straight line. This suggests the existence of a constant term, and a 
number of constants were tried until it was found that the curve be- 
tween log (?/2+5.5) and log a? is a straight line. The curve above 12 
days or 12% then is log (y 2 -j-5.5)=log a-{-nlog x. 
