CAPILLARY MOVEMENT OF SOIL MOISTURE. 
63 
CAPILLARY MOVEMENT OF MOISTURE FROM A WET TO A DRY 
SOIL, 
As has been stated previously, the movement of moisture by capil- 
larity is much slower and not so extensive in the absence of free 
water as it is in the presence of free water. When a wet soil and a 
dry soil are in contact, gravity exerts an appreciable influence in the 
capillary movement of moisture. 
The experimental work so far done at Riverside does not war- 
rant more than a few general statements. To give some idea of the 
nature of this work a few experimental results will be given. 
THE VERTICAL BOXES. 
The soil boxes were placed in vertical and horizontal positions only. 
In the vertical boxes the wet soil was placed in some cases on top, 
in others at the bottom, and in others the wet soil was placed in the 
middle section and dry soils at both ends. 
Nearly all boxes were 6 feet in length and the wet soil occupied 
one half this length and the dry soil the other half. 
MOVEMENT OF MOISTURE UPWAED. 
In table 43 are given data of a few of the boxes in which the soil 
moistened to the percentages shown were placed at the lower ends of 
Table 43. — Movement of moisture upward in the ooxes. 
Days. 
Riverside soil, 
initial percentage. 
Idaho lava soil, 
initial percentage. 
Whittier son, 
initial percentage. 
20 per 
cent. 
10 per 
cent. 
14 per 
cent. 
20 per 
cent. 
25 per 
. cent. 
40 per 
cent. 
30 per 
cent. 
1 
o 
4 
G 
8 
9 
11 
12 
14 
16 
23 
26 
37 
40 
49 
56 
71 
B6 
Inches. 
1.12 
2.25 
3.00 
3.37 
4.00 
4.50 
4.82 
5.00 
5.37 
Inches. 
Inches. 
Inches. 
1.50 
Inches. 
Inches. 
Inches. 
:::::::::::: 
1.00 
1.25 
1.25 
2.25 
1.83 
2.00 
3.25 
4.50 
2.25 
2.75 
7.00 
6.50 
4.50 
8.37 
4.37 
3.25 
7. 75 
1.70 
1.00 
1.75 
10.75 
3.50 
6.83 
10.50 
11.00 
12.75 
G.50 
1 

14. 25 
the boxes and air-dried soils at the ujDper ends. The table shows 
that the box containing the Riverside' soil, with the lower half 20 per 
cent of moisture, the movement of the moisture up into the dry soil 
was about one-fourth as great in 4 daj^s as it was in 56 days, In the 
box of Eiverside soil, containing 10 per cent moisture in the wet 
