Apr. 9.1917 
Water-Retmning Capacity of Soil 
45 
Table XII .—Loss of water from a uniform soil , /, protected from all loss at the sides 
and below , but fully exposed to evaporation at the surface . All cylinders were filled on 
February 14 with soil containing 11.8 per cent of water 
Depth 0! section. 
Water content on opening cylinder. 
Loss of water. 
March 7. 
May 
1. 
In 32 
days. 
In 77 days. 
Cylinder 
I (Sur¬ 
face 
mulched). 
Cylin¬ 
der II 
(Sur¬ 
face 
packed). 
Cylinder 
III (Sur¬ 
face 
mulched). 
Cylin- : 
derlV 
(Sur¬ 
face 
packed). 
Cylin¬ 
der I. 
Cylin¬ 
der II. 
Cylin¬ 
der III. 
Cylin¬ 
der IV. 
Inches . 
Per ct . 
Per ct . 
Per ct . 
Perct . 
Per ct . 
Per ct . 
Per ct . 
Per ct . 
3-0 
3-3 
2. 2 
2. 2 
8,8 
8*5 
9.6 
9.6 
4.4 
& 5 
2. 2 
2.4 
7-4 
5-3 
9.6 
9-4 
3 . 
7-4 
8. 2 
3-8 
4.6 
4 * 4 
3-6 
8.0 
7.2 
8.8 
8.6 
5-6 
6. 2 
3 -o 
3*2 
6. 2 
5-6 
5 ^ . 
9. 1 
9. 1 
6. 8 
7-4 
2.7 
2.7 
5 -o 
4.4 
9-5 
9-4 
7*4 
7.8 
2. 3 
2.4 
4.4 
4*0 
7 . 
9-5 
10. 0 
7.8 
8.8 
2*3 
1.8 
4. 0 
3 *o 
8 . 
9 - 7 
10. 1 
8. 1 
8. 6 
2. 1 
7 
3-7 
3-2 
9 . 
9.9 
10. 1 
8.3 
8.9 
1.9 
J -7 
3-5 
2.9 
10... 
10. 1 
10. 7. 
9. 0 
0. 1 
1. 7 
1. 
2. 8 
2 . 7 
11 . 
10.3 
O 
1 °-5 
9. 1 
7 
9-4 
i- 5 
i -3 
2.8 
2.4 
12. 
10. 4 
10, 6 
9.2 
9-5 
1.4 
1. 2 
2. 6 
2-3 
13. 
10. 6 
10. 8 
9*7 
9 - 5 
i- 5 
1. 0 
2. 1 
2*3 
14. 
10. 9 
10. 9 
10. 0 
9.8 
J -5 
•9 
1.8 
2. O 
15. 
11. 0 
11.1 
10. 0 
10. 1 
1. 2 
• 7 
1. 8 
1.7 
16. 
11. 2 
11. 2 
9.9 
10. 0 
•9 
.6 
1.9 
1.8 
17 . 
11. 0 
11. 4 
9.8 
9.9 
.8 
•4 
2. 0 
1.9 
18.. 
11. 1 
11. 4 
9.9 
9.9 
. 6 
*4 
1.9 
1.9 
19. 
11.1 
11. 4 
10. 0 
10. 7 
.8 
■4 
1.8 
1.1 
20. 
11. 1 
11. 4 
10. 0 
10. 6 
• 7 
• 4 
1.8 
1. 2 
21 .., . 
11. 2 
11. 4 
10. 1 
10. 2 
• 7 
•4 
i *7 
1. 2 
22 . 
11. 4 
11. 4 
10. 2 
io -3 
• 7 
•4 
i -7 
1. 6 
23 . 
11. 4 
11. 4 
10. 4 
10, 3 
. 6 
•4 
1.6 
i *5 
24 . 
”•5 
11. 4 
i°- 5 
10. 4 
•4 
•4 
1.4 
i -5 
25 . 
11. 4 
11. 4 
10. 6 
10. 7 
.4 
-4 
i -3 
1.4 
26 . 
i 1 * 5 
ii -5 
10. 7 
10. 8 
•3 
•3 
1. 2 
1.1 
27 . 
11. 4 
ii- 5 
10. 7 
10. 7 
*4 
•3 
1. 1 
1.0 
”•5 
ii- 5 
10. 9 
10. 7 
•3 
• 3 
1. 1 
1.1 
29 . 
ii- 5 
11. 6 
10. 9 
10. 8 
*3 
. 2 
•9 
1.1 
30 . 
ii- 5 
11. 7 
11. 0 
10. 8 
•3 
. 1 
*9 
1.0 
3 i . 
ii- 5 
11. 7 
11. 0 
11. 0 
•3 
. 1 
.8 
1.0 
32 . 
ii -5 
n. 7 
11. 0 
10. 8 
•3 
. 1 
.8 
1.0 
33 . 
ii- 5 
11. 8 
11. 0 
10. 8 
•3 
. 0 
.8 
1.0 
34 . 
11. 8 
11. 8 
11. 0 
10. 8 
, 0 
. 0 
.8 
1,0 
11. 8 
11. 8 
11. 0 
10. 8 
. 0 
, 0 
. 8 
1. 0 
. 
J J 
36 . 
11. 8 
11. 8 
11. 0 
10. 8 
. 0 
. 0 
.8 
1. 0 
Average . 
10.3 
10. 6 
9.2 
9-4 
i -5 
1. 2 
2.6 
2.4 
The movement from the portion of the subsoil below the twelfth inch 
evidently becomes exceedingly slow after the moisture content has fallen 
to a point approximately twice the hygroscopic coefficient. It should 
not be overlooked, however, that the point at which movement upward 
into the very dry surface has practically ceased is appreciably below 
that at which it occurred with the downward movement into the moist 
mass of the natural subsoil (Table XII), the ratio being 1.9 or 2.0 with 
the former and 2.4 with the latter. However, if even this close a con¬ 
cordance is found to hold in the field, the knowledge of the ratio would be 
very useful. Applying it, we should expect that a subsoil such as J with 
