hee 
* 
DISTRIBUTION OF MOISTURE IN SOIL COLUMNS. 11 
tance from the left or bottom end, and occurs from the twelfth to the 
fifteenth inch. It is also seen that the highest point in these curves, 
representing the maximum percentage of moisture, is about the same 
in all three tubes. The curves show that in tube No.5 there is more 
moisture in each inch from the second to the thirty-fifth inclusive, 
than in the bottom or first inch. In tube No. 7, there is more mois- 
ture at each inch from the second to be twenty-seventh inclusive than 
in the first inch; in tube No. 6, there is more moisture at each inch 
except two from the second to the twenty-eighth inclusive than in the 
bottom inch. 
In all three curves there is more than one “node” or apex. How- 
ever, with the exception of the highest one the others are not very 
pronounced. Ifa straight line be drawn from the highest apex of the 
curves for tubes Nos. 6 and 7 to the left end of the line it will be found 
to represent about the average of the percentages represented in that 
part of the curved line. If from this same apex a straight line be 
drawn to within 3 or 4 inches of the right end of the curve, it will 
correspond very closely to the average percentage of moisture repre- 
sented by this line. 
Table 4 shows a considerable variation in the percentages of mois- 
ture found in the bottom few inches of tubes Nos. 5, 6, and 7. In 
tube No. 5 the maximum percentage of moisture is found at the 
twelfth inch, in tube No. 6 at the fourteenth inch, and in tube No. 7 
at the fifteenth inch. 
In all three tubes there are high and low apexes or peaks in the 
bottom half of the tubes. The average percentage of moisture in the 
lower part of each tube is, for tube No. 5, 29.03 per cent in the first 
14 inches; for tube No. 6, 29.93 per cent in the first 15 inches; and for 
tube No. 7, 30.96 per cent in the first 16 inches. In view of the 
different treatment the tubes received, the close agreement of these 
percentages is remarkable. Tubes Nos. 5 and 7 agree very closely in 
the remainder of the columns, but tube No. 6 has a slightly lower 
moisture content than either in the second quarter. In tube No. 5, 
the average percentage of moisture found between the fourteenth and 
twenty-eighth inches is 4 per cent higher than the average percentage 
found from the first to the fourteenth inch. In tube No. 6 the 
average percentage of moisture in the first 15 inches is 29.93 and in 
the second 15 inches 27.38 per cent. The average percentage of 
moisture found in these tubes at the end of the experiment was 25.65 
per cent, 24.62 per cent, and 25.93 per cent, respectively. Tubes 
Nos. 5 and 7 agree very closely in these averages. 
From the table it is found that tube No. 5 contained the average 
percentage of moisture at about the thirty-third inch, or a little 
more than half way up the tube. Tube No. 6 contained the average 
percentage of moisture at about the thirty-fourth inch, and tube No. 
7 about the thirty-sixth inch. Thus in all these tubes the average 
percentage of moisture occurs just above the middle of the tube, and 
in this — they differ from the first four tubes filled with the Idaho 
sandy soil. The maximum percentage of moisture found in tube No. 
5 is about one-third greater than the percentage in the first or bottom 
inch. The maximum in tube No. 6 is 34.13 per cent while in the first 
inch the moisture content is only 26.24 per cent. In tube No. 7 the 
maximum is 34.74 per cent while the first inch contains 28.82 per 
cent of moisture. 
