20 
Bulletin 103. 
be noticed that the water on the sides of the tubes is above the 
height of the water in the basin and the smaller the tube the higher 
will be the water on the sides of the tube. 
“The force which causes the water to rise in these tubes is 
called capillary force, from an old Latin word capillum, (a hair), 
because it is most marked in hairlike tubes, the smaller the tube the 
higher the water will rise. The water which rises in the tube is 
called ‘capillary water.”’ (Goodrich’s First Book of Farming). 
This book of Mr. C. L. Goodrich (formerly instructor in Agri¬ 
culture in Agricultural Institute, Hampton, Va.,) shows that, for 
their best development and growth, roots of plants must have a 
firm, mellow soil, a ventilated soil, a warm soil, a soil supplied with 
plant food and a moist soil. The following interesting diagram 
teaches the relative amounts of film moisture held by coarse and 
fine soils. Here are two tumblers, one with a half pound of coarse 
soil, the other with a half pound of fine, sandy loam. In a small 
phial is shown the amount of water necessary to cover each half 
pound with a film of moisture. It requires more than five times as 
much water for the sand as it does for the coarse soil. 
A. B CD. 
COLO. AG. £XPT. 5TA. 
FIGURE 6. 
A. Coarse soil. 
B. Phial containing amount of water necessary to cover the coarse 
soil with a thin film of moisture. 
C. Phial containing the amount of water necessary to cover the fine 
sandy loam with a thin film of moisture. 
D. Fine sandy loam. 
This shows that fining the soil increases the capillarity of the 
soil, its power to hold capillary water. 
It has been estimated by careful agriculturists that the film 
surface of a cubic foot of clay loam spread out would cover three- 
fourths of an acre. When these capillary tubes of the soil extend 
to the surface the hot sun of our semi-arid lands pumps the water 
from them which is seemingly wasted in the dry air of these regions. 
The earth mulch is the dry blanket which breaks capillary con¬ 
nection between the under surface soil tubes and the hot outer sur- 
