210 Moisture Equilibrium [408 
as possible, the other as far removed as possible. The aver- 
age of the two was taken to be representative of the entire 
soil mass. Each sample was removed and dried in eight 
2-em. sections, so that it was possible to study both the ver- 
tical and horizontal distribution of the soil moisture in the 
cylinder. There was a horizontal as well as a vertical varia- 
tion of small magnitude in the soil-moisture content of 
all the cylinders, the water content being almost always 
somewhat higher near the cups and at the bottom. of the soil 
mass. The distribution of the moisture, both horizontal 
and vertical, was more uniform in the sand-loam mixture 
than in the sand, and also more uniform in the loam than 
in the mixture. The number of porous cups used had very 
little influence, if any, upon the soil moisture content of the 
loam; it varied as 100 : 106 : 103, for the containers having 
one, three and five porous cups, respectively. This influence 
of the number of cups was more pronounced in the case of 
the sand-loam mixture, the variation, with one, three and 
five cups, being 100 : 147 : 168. With the sand there was a 
still more marked effect, the moisture contents for the three 
cup numbers being 100 :191 : 277 in this case. These vari- 
ations are all smaller than the corresponding variations in 
the value of the ratio of cup number to soil mass, these values 
varying as 100 : 321 : 576, for all three soils. For the con- 
tainers with three cups the actual average soil moisture con- 
tent (on the basis of dry weight) was 11.0 per cent. for the 
loam, 5.2 per cent. for the mixture, and 1.1 per cent. for the 
sand. ; 
With the pressure here used (averaging 5.5 em. of a mer- 
cury column) the soil moisture content at equilibrium was 
too low for plant cultures in the sand and perhaps also in the 
sand-loam mixture. In the loam, however, it was surely high 
enough to supply plants with the water necessary for their 
growth under ordinary greenhouse conditions. 
