CAPILLAKY MOYEMEXT OF SOIL MOISTURE. 
59 
after the moisture kad reached the lower end of the flume inclined 
downward at an angle of 15° free water commenced dripping from 
the lower end. The water continued to drip from the ends of all 
three of these flumes for at least two weeks, or until the flumes were 
dismantled. It must he kept in mind that this water was raised 
from the tank a vertical distance of 4 inches by capillarity and 
against gravity. It was then transmitted down the flumes by means 
of the same force and in a direction with gravity. The moisture 
left the soil column at the lower end of the flume as free water, drop- 
ping to the ground. At no point in the entire length of the soil 
column, with the possible exception of the extreme lower end of the 
flume, was the percentage of moisture in the soil as great as that of 
capillary saturation, as measured by the 
general methods for determining this 
percentage. This, then, is in effect 
transferring water from a body of free 
water by capillarity and delivering it 
again as free water. 
To supplement the results from the 
flumes and to test the further possibility 
of creating a capillary siphon, a special 
piece of apparatus shown in figure 10 
was set up, 
A-B hi figure 10 is a galvanized-iron 
tube 7 by 7 inches in area and made in 
the shape shown. This box is water- 
tight and air-tight except along the top 
X-B, at the bottom of the short arm at 
C\ and at a point D at the bottom of the 
long arm. This tube stands vertical 
and rests on A. The top along the line 
X-B is open to the air. The lower end 
of the short arm at C has soldered over it 
a fine-meshed wire gauze. D is a f-inch ell soldered into the lower 
end of the long arm ; the top of the ell is fitted with a water-gauge 
connection. Into the top of this ell is fitted a gauge glass X-D, on the 
outside of the tank or tube. The tube is packed with soil as indicated 
and the soil is exposed to the air along the line X-B. The short 
arm of the tube extends down into a tank of water represented by 
water line in tank. 
It is observed from figure 10 that the high-water line in the 
tank is 8 inches below the bottom of the horizontal part of the tube. 
This 8 inches is then the distance the water must be raised from the 
tank before it can move horizontallv. It must then move hori- 
FlG. 
10. — The soil column as a 
capillary siphon. 
