CAPILLARY MOVEMENT OF SOIL MOISTURE. 
17 
The distance moved in 2 hours, in percentage of the total distance 
moved in 30 days, or 720 hours, was as follows: * 
Flume 19, 20 per cent; flume 43, 13 per cent; flume 63, 13 per cent; 
flume 80, 13 per cent; flume 100, 9 per cent: flume 209, 36 per cent. 
In 2 hours, or 1/360 of the time, the percentage ranges from 36 in the 
light Idaho soil to 9 in the heavy Idaho soil, or from about one-tenth 
to about one-third the total distance. 
About the same relative rate of movement of moisture for the first 
few hours of the experiment is shown by Table 2. In the first 8 
hours, or one-third of the 21 hours, the moisture had moved upward 
more than 70 per cent of the total distance moved in 21 hours, while 
in the longer period of 30 days it is found that more than 80 per cent 
of the total distance was covered in one-third of the time. 
The above tables and diagram but emphasize and give in some de- 
tail the rapid action of capillary moisture when soils are first placed 
in contact with free water, and show that a large part of the total dis- 
tance the moisture will move in a month is covered within the first 
few hours. These results are in accord with those obtained by 
others. (9) 
WATEK I7SED. 
The figures within the small circles in figure 2 give, in liters, the 
total quantity of water removed from the tanks by the soil columns 
at the end of various periods of time. 
At the end of 30 days, flume 63 had taken about 30 per cent more 
water than had flume 19, and flume 100 had taken up nearly twice as 
much water as flume 19. Flume 209 used very little water after the 
first 6 days and a large part of the total water used in the 30 days 
was used the first day. At the end of 30 days this flume had used only 
about one-half as much water as flume 19. These figures show, as 
was to be expected, that the lighter soils require less water per inch 
than do the heavier soils. 
Table 3. — Quantity of water used to move moisture an average distance of 1 
inch at the end of different periods of time. 
Flume . 
Number 
of davs. 
19 
43 
63 
- 80 
100 
2C9 
Liters. 
Liters. 
Liters. 
Liters. 
Liters. 
Liters. 
1 
0.422 
0.446 
0.700 
0.250 
0.482 
0.296 
2 
.393 
.526 
.737 
.256 
.468 
.276 
3 
.392 
.506 
.726 
.323 
.506 
.265 
4 
.379 
.500 
.772 
.311 
.527 
.259 
10 
.366 
.470 
.789 
.326 
.497 
.254 
20 
30 
.364 
.357 
.484 
.472 
.840 
.317 
.488 
.4S4 
.816 
.327 
.239 
147697°— 20— Bull. 835- 
