CAPILLAKY MOVEMENT OF SOIL MOISTURE. 
33 
WATER Used. 
Table 19. — Water used, by days, in 
percentages of total use in 30 days. 
The figures in the small circles show in liters the water used by 
these flumes. The water used by flumes inclined downward is, like 
the movement of the moisture, greater than for the horizontal or 
vertical flumes. A striking feature is the rather uniform use of a. 
comparatively constant quantity of water after the second or third 
day. The rate of use is more constant and uniform than for the 
vertical or horizontal flumes. Flume 34 had used on the tenth day 
about 4 liters of water; on the twentieth clay about 8 liters; on the 
thirtieth day about 11.5 liters; and on the fortieth day about 14 
liters. In flume 54 with the heavy Whittier soil an even greater 
uniformity is observed. In this flume there was used approximately 
the same quantity of water every day after the sixth day up to the 
fifty-seventh clay, or at the end of the experiment. The same 
uniformity is found, in fact, in 
nearly all of the other flumes. 
One fact worth special notice is 
that the use of water by the flume 
as represented by the loss of 
water from the tanks is that 
evaporation does not appear to 
have varied the use to any ex- 
tent. This is true though the 
same flume was exposed to al- 
most all 'the different and vari- 
able weather conditions found at 
Riverside. To show the relative 
uniformity in the rate of use of water by some of these flumes 
Table 19 has been prepared. 
Table 19 shows that the heavier soils use relatively more water 
at the commencement than near the end of the experiment. It shows, 
also, a more uniform use by the heavier soils. It shows, for instance, 
that the soil in flume 54 had used relatively more than twice as much 
water as any other flume at the end of the first clay, while on the fif- 
teenth day it had used relatively only about one-fifth more than the 
others. Table 20 shows the amount of water required at different 
periods of time to advance the moisture in the flumes an average dis- 
tance of 1 inch. For instance, on the third day, flume 24 had used 
18 liters of water and the moisture had advanced 44.15 inches, or an 
average of 479 cubic centimeters of water was required per inch. 
A comparison of the figures in Table 20 with the moisture equiva- 
lents of the soils appears to show no close relation. However, in a 
general Avay the greater the moisture equivalent the greater the 
quantity of water required to advance the moisture 1 inch. It is ob- 
147697°— 20— Bull. 835 3 
Flu 
mi 
Number 
of days. 
34 
51 
74 
C-4 
Per cent. 
Per cent. 
Per cent. 
Per cent. 
1 
9 
22 
10 
11 
3 
18 
£0 
19 
20 
5 
23 
43 
25 
28 
10 
39 
57 
41 
43 
15 
54 
C8 
55 
57 
20 
71? 
78 
G8 
;o 
30 
100 
100 
100 
100 
40 
50 
121 
127 
149 
129 
! 

