WATER CAPACITY OF SOILS. 
Table II contains data illustrating the water capacities of these 
soils. Columns 4 and 5 show the percentage of water by weight and 
volume, respectively, required to saturate the soil, and columns 6 and 
7 show the percentage by weight and volume required to saturate 
and fill interstitial spaces. 
Table II. — Water capacity of the soils . 
Sou No. 
Weight 
of soil. 
Volume 
of soil. 
Percentage of wa- 
ter to saturate. 
Percentage of water 
to saturate and 
fill spaces. 
Weight. 
Volume. 
Weight. 
Volume. 
428 
Gm. 
150 
150 
150 
150 
150 
150 
150 
Cc. 
177 
168 
176 
132 
160 
189 
161 
Per cent. 
61.1 
60.2 
66.3 
43.7 
61.7 
76.3 
50.3 
Per cent. 
51.8 
53.7 
56.5 
49.6 
57.8 
60.7 
46.9 
Per cent. 
64.8 
64.3 
71.6 
48.3 
63.7 
76.3 
62.6 
Per cent. 
55.1 
448 
57 5 
516 
61.0 
530 
54.7 
542 
59.7 
573 
60.7 
574 
58.3 
SPECIFIC GRAVITY. 
In Table III are given the specific gravities, both real and apparent, 
as well as the comparative volume occupied by 10 grams of these 
soils, excluding intei-stitial spaces,' as determined upon the air-dry 
soils. 
Table III. — Specific gravity and volume of the soils. 
Soil No. 
Real 
specific 
gravity. 
Apparent 
specific 
gravity. 
Volume 
occupied. 
Soil No. 
Real 
specific 
gravity. 
Apparent 
specific 
gravity. 
Volume 
occupied. 
428 
2.4825 
2.5264 
2.8351 
2.9438 
0.8474 
.8929 
.8522 
1.1363 
Cc. 
4.03 
3.96 
3.53 
3.40 
542 
2. 8784 
2.4454 
2.9087 
0.9375 
.7936 
.9316 
Cc. 
3.48 
44S 
573- . . 
4 09 
516. 
574 
3.46 
530 
The foregoing data, while of more or less empirical nature, indicate 
the variation in physical properties of Hawaiian types of soil. The 
clays show the highest specific gravity, both real and apparent, the 
clay silts and silts next, while the sandy soils show the lowest. The 
opposite relation exists with regard to the volume and water capacity. 
CAPILLARY MOVEMENT. 
Upon the capillary movement of water more than upon any other 
physical factor is the plant dependent for successful growth. The 
functions of capillary water are many and involve the transmission 
of plant food from the soil to the plant, sustenance of the enormous 
evaporation during the heat of the day, and the like. By means of 
81436°— Bull. 38—15 2 
