DISTRIBUTION OF MOISTURE IN SOIL COLUMNS. 9 
tube No. 4 stood 12 days longer than tube No. 1, and the moisture in 
the former had reached not more than 1 inch higher than in the latter. 
Without analyzing in detail all the figures representing the per- 
centages of moisture, it is found that in all of the tubes the maximum 
ercentage of moisture is near the fifth inch, or about one-fifth the 
arnt to which the moisture had reached, and is appreciably greater 
at this point than in the first or second inch. It 1s also found that 
the percentage of moisture in the inch next to the top inch is between 
one-fourth and one-fifth of the maximum. 
Although treated in different ways and standing different lengths 
of time the four tubes show very uniform average percentages of 
moisture. Almost the same average is found in the first 6 inches of 
the four tubes with a minimum of 22.64 per cent in tube No. 1 and 
23.87 per cent in tube No. 3. The second 6 inches in each tube shows 
the greatest variation in average moisture percentage. 
The average percentage of moisture contained in the whole tube is 
found in tube No. 1 between the tenth and the eleventh inch; in tube 
No. 2 at about the tenth inch; in tube No. 3 between the eleventh 
and twelfth inch, and in tube No. 4 between the tenth and eleventh 
inch. In ali of these tubes the average percentage of moisture is 
found at a little less than half the height of the wetted part of the 
column. 
There is nothing in the table to indicate that the height at which 
the maximum percentage of moisture occurs is influenced either by 
the length of time, between 30 and 40 days, that the tubes were left 
standing, or by the methods of packing. These four tubes, showing 
as they do that the greatest percentage of moisture is about 5 inches 
above the water, afford a reasonable basis for saying that such a 
condition would be found in other tubes, filled with the same or a 
similar soil. The four tubes do not represent all the tests made with 
this soil in vertical columns, but are representative of 8 or 10. In 
no tube of all the experiments with this soil was the maximum per- 
centage of moisture found below the third inch. It was found that 
in tube No. 1, 71 per cent of all the moisture in the whole tube was 
in the bottom half. In tubes Nos. 2 and 3, there was found in the 
bottom half 70 per cent of all the moisture in the tubes. 
IDAHO LAVA ASH SOIL. 
The second set of experiments was conducted with Idaho lava ash 
soil. This soil differs widely from the Idaho sandy soil. It is a fine- 
grained soil, has a different base, and a much greater capillary power. 
It is also a soil that cracks in drying after saturation and is quite 
sticky when wet. The set of experiments consisted of four tubes, 
each of which was treated differently, either in packing or in method 
of sampling. 
Tube No. 5 was packed in 2-inch layers by lifting and dropping the 
whole tube for each layer, following the method used in packing 
tube No. 1. The tube was allowed to stand in a vertical position for 
30 days. It was then taken down and sampled immediately. 
Tube No. 6 was packed by dropping the soil a definite distance for 
each 2-inch layer. The tube was allowed to stand 35 days. It was 
then removed from the water and allowed to stand 24 hours before 
sampling. 
683 19°—24——_2 
