Nov. 20 ,1916 Determination of Hygroscopic Coefficients of Soils 
357 
TabuS X .—Moisture conditions in typical fields of western Nebraska in May, IQ12, 
showing the applicability of the data obtained by computing the hygroscopic coefficient 
from the hygroscopic water in the air-dried soil 
A.—TOTAL WATER IN SOIL IN FIELD 
Depth. 
Prairies. 
Com stubble. 
Winter wheat. 
I 
II 
ill 
IV 
V 
VI 
VII 
VIII 
Foot. 
P. ct. 
P. ct. 
P. ct. 
P. ct. 
P. ct. 
P. ct. 
P. ct. 
P. ct. 
o-K . 
3*6 
19.4 
17.1 
16. 3 
7*3 
18. 9 
20 . 4 
20. I 
K-i. 
4 . 5 
21. 6 
20 . 2 
18.7 
10. 0 
21. 6 
21. 5 
22 . O 
5*4 
14-3 
I9.9 
17. 8 
8.7 
19-3 
16. 0 
IS* i 
3 .. 
7*9 
9.4 
14-3 
i 3 - 1 
8.5 
13.8 
12.3 
I°- 5 
4. 
6.9 
8. 0 
9.6 
12. 0 
10. 0 
9.8 
10. 7 
9.6 
5 . 
5 - 9 
8. 1 
9. I 
10. 5 
15.6 
9.2 
9*4 
9*4 
6. 
6. 1 
8.8 
9. I 
6.9 
21.3 
9*4 
8.8 
9.6 
Average a . 
6. 0 
ii- 5 
13-4 
13. 0 
12. 1 
13.6 
H 
OO 
0 
12* 5 
B.—FREE WATER (USING DETERMINED HYGROSCOPIC COEFFICIENTS) 
0-K. 
2. 0 
10. 8 
8.2 
10. 4 
5*3 
10. 4 
12; 2 
12.8 
K-I. 
2.9 
11. 0 
10. 7 
i°* 5 
7 * 1 
ii* 5 
11. 2 
i 3*4 
3*8 
4.0 
9 * 5 
9*5 
6. 1 
9 * 1 
6.2 
7*3 
3 . 
6. 0 
1. 1 
4*3 
3 * 7 
5*9 
5*3 
3 * 9 
1. 1 
4 . 
5*4 
•5 
. 0 
2. 0 
7.0 
i *7 
2.9 
*9 
5 . 
4.6 
•3 
• 7 
2.7 
10. 0 
i *5 
1.9 
.8 
4. 8 
1. 2 
i* 5 
2.4 
12.4 
•9 
1.4 
2. 1 
Average. 
4. 2 
3 * 0 
4. 0 
5 * 1 
7*9 
4.9 
4*7 
4. 2 
C.—FREE WATER (USING COMPUTED HYGROSCOPIC COEFFICIENTS) 
o -}4 . 
2. 1 
10. 5 
7*9 
9*7 
5*3 
9.0 
10. 7 
12. 6 
K-i. 
3 * 0 
10. 2 
10. 7 
10.3 
7.2 
10. 1 
9.8 
12.8 
3*6 
3 * 1 
10. 2 
7.8 
5*9 
8.6 
3 * 1 
3*6 
3..•*•• 
6. 1 
. 0 
4.6 
i *9 
5*7 
4. 1 
2.4 
- .4 
5*4 
- *7 
— . 1 
■3 
6.4 
1. 1 
2. 7 
- .8 
<.. 
4 . 6 
- .8 
. 7 
8. 2 
1. 3 
1. 4 
A* 
1. 6 
6 . 
4.8 
“ *3 
• 7 
2. 6 
0 
12. 1 
1* 5 
I. O 
1.8 
Average. 
4. 2 
1.9 
4. 2 
& 4. 2 
7*4 
4*4 
3 * 5 
3 * 1 
» In estimating both the average hygroscopic coefficient and the average moisture content of the 6 feet 
of soil we have employed the mean for the first foot instead of averaging the seven data in each column. 
& In estimating the average the missing datum is replaced by that from the preceding part of the table. 
It should be pointed out that in the case of all the soils with which 
we have employed the simpler method, so satisfactorily the samples 
either had been dried at no° C. or for many months had been exposed 
to the dry air of the storeroom and so had attained an air-dried con¬ 
dition, As it would in many instances be more convenient if the moist 
samples could be exposed on paper trays or plates and left until they 
came into equilibrium with the atmosphere, we exposed for varying 
periods—2 to 21 days—10 to 15 gm. samples of the control soils, H, 
Ta, and S, all containing the maximum hygroscopic moisture, together 
