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IOWA ACADEMY OF SCIENCE Voi,. XXVII, 1920 
Fig. 29. Soil moisture content in per cent of air-dry soil for the top of timbered 
and open slopes — stations II and X, respectively.- Rainfall, shown in solid columns 
at bottom, was approximately as follows: 
For July: 5, .01 in.; 8, .43 in.; 9, 1.05 in.; 17, .01 in.; 19, .02 in.; 21, .16 in.; 
27, .40 in.; 28, .42 in.; 30, .73 in.; 31, .43 in. 
For August: 3, 1.30 in.; 4, .04 in.; 6, .30 in.; 13, 1.17 in.; 17, .30 in.; 18, .10 in.; 
20, .75 in.; 22, 1.0 in.; 30, .40 in. 
minima fall to points ranging only from .95 to 3.05 per cent above 
those for the timber soils. 
Another interesting observation is the deficiency of moisture 
toward the latter part of the season in the subsurface layers of 
the open slope, especially at the middle and foot. These soils 
show the lowest constant average of any of the soils, after the 
general drop in July, while the corresponding timber soils show 
averages approximately the same as or higher than the normal 
for the others. 
These considerations, in view of the character of the rainfall 
during this period, are undoubtedly significant, in that the precip- 
itation was almost entirely in the form of heavy showers, tending 
