Apr. 9.1917 
Water-Retaining Capacity of Soil 
39 
term “free water” is used to designate the difference between the total 
water and the hygroscopic coefficient (14, p. 66) and is not synonymous 
Cylinder/ Cylinder// Cylinder/// Cylinder /V Cylinder V Cylinder}// Cylinder y// 
Legenof; 
Hygroscopic Coefficient _ 
Free /Va/er. ... .■■■■ 
Fig., i.—D iagram showing the relation of the percentage of water retained to the hygroscopic coefficient 
and the influence of an interrupting layer of coarse sand (soil Q). The seven soil columns, consisting of 
a-inch layers of six different soils variously arranged, were saturated and then allowed to stand for 69 days 
protected from evaporation and in contact with the natural subsoil mass. 
with “gravitational water” as it is employed by some (15, p. 207). The 
data are presented graphically in figure 1. 
Table VI .—Total water in the successive soil layers a 
Table VII .—Free water in the successive soil layers 
Depth. 
Cylinder No. 
I. 
11 . 
m. 
IV. 
V. 
VI. 
VII. 
P. ct. 
P. ct. 
P.d 
P. d. 
p. d. 
P.d. 
P. ct. 
1.7 
*■ 7 
8.8 
17*3 
28 . 4 
27.4 
25 .O 
4.3 
18.2 
1.9 
7-8 
17 . 0 
26.6 
25 . 8 
7.8 
21.7 
17.7 
2 . O 
p.° 
16.5 
26 . 3 
14. 6 
15*5 
21 . 4 
x 7* 3 
5-9 
8.7 
18 . I 
21 . 6 
8 . 2 
12 . 2 
21 . 6 
16.8 
1.8 
10. 0 
17.1 
4.3 
7.8 
IS -6 
21 . 0 
l 6 . 2 
-2JJ 
Inches. 
1-2 . 
3-4 .-. 
5-6 . 
7-8 . 
9^10 .. 
II—12. 
