22 
BULLETIX 835, U. S. DEPARTMENT OF AGRICULTURE, 
found at a height of 6 inches above the water. In flame 63 there 
is a greater percentage of moisture in the twelfth inch than in either 
the sixth or the ninth inches. In both flumes there is a decrease in 
the percentage of moisture with height above the twelfth inch. In 
flume 43 there is a much more constant and uniform, percentage of 
moisture from the twelfth inch to near the top of the wet area 
than there is in flume 63. In both flumes, the moisture content breaks 
very abruptly near the upper end of the wet soil and indicates the 
relatively high percentage of moisture necessary to allow the mois- 
ture to move from the wet to the dry soil. 
Other and very much more numerous data show the irregularity 
of moisture distribution in vertical columns even though every pre- 
caution is taken to have the soil uniform in texture and in density. 
A superficial study of these data would indicate that a formula that 
would give the distribution of moisture in vertical soil columns for 
a period of 30 days would be more complicated than the formula 
for the movement of moisture. An analysis of the above statement 
would indicate that the percentage of moisture which will permit 
the advance of moisture from the wet to the dry soil is variable, 
even for uniform temperatures, etc. 
The data for flumes 43 and 63 given above, and numerous other 
data show a distribution of moisture contrary to general supposition. 
That there is a lack of uniformity in the distribution of moisture 
in vertical soil columns has been observed by others (6) , (13). 
THE MOVEMENT OF MOISTURE IN HORIZONTAL FLUMES. 
The horizontal capillary movement of moisture within the soil and 
from a body of free water has not been studied before to any great 
extent (12). 
Much of what has been said of the vertical flumes is ap23licable to 
the horizontal flumes. The chief difference is rather one of degree 
At the present time there will be discussed only the horizontal 
flumes open on top to evaporation. 
The number of flumes and the soil contained in each is given in 
Table 10. 
Table 10. — Soil in horizontal flumes. 
Number 
of flume. 
Description. 
31 
50 
70 
90 
200 
Decomposed granite soil from Riverside. Calif. 
Heavy decomposed ei anil e soil from Riverside, Calif. 
Heavy clay loam from WJiittier, Calif. 
Sand'and gravel wash from Uplands. Calif. 
Heavy lava ash from Idaho. 
Light sand soil from Idaho. 
Figure 3 shows the curves derived from the measurement of 
the movement of moisture in the horizontal flumes and the time 
