16 Bulletin 57. 
placed and well tramped, that is, half an hour later with a 
weight of fifteen pounds to the square inch, the layer was 
34 'Y2 inches thick, giving a weight of 23 pounds to the cubic 
foot. In another hour,; with a weight on top of 95 pounds to 
the square foot, the layer had been squeezed five inches 
thinner and weighed 27 pounds to the cubic foot. The next 
morning with an average pressure of about 213 pounds to 
the square foot, the layer weighed 31 pounds to the cubic 
foot. During the next two days the silo was filled up, cov¬ 
ered with wet straw, allowed to stand four days and then 
covered with wet dirt. This gave an average pressure of 
323 pounds to the square foot. Three days later, that is 
ten days after the corn was put in the silo, the bottom 
layer had settled 7 inches to i 8*4 inches thick, or 44 pounds 
to the cubic foot. Six weeks later it had settled two inches 
more and another inch in the next month. It then weighed 
50.7 pounds to the cubic foot. When the pressure was re¬ 
moved by the throwing out of the upper layers, this bottom 
layer expanded one inch from 15^ to 16K inches, or from 
50.7 pounds to the cubic foot to 47.9 pounds. 
The next to the bottom layer contained 9721 pounds of 
fodder corn. An hour after it was put in the silo, when it 
was weighted 35 pounds to the square foot, it made a layer 
58 inches thick, or 20 pounds to the cubic foot. By the next 
day at noon, with 125 pounds of weight to the square foot, 
the layer had been reduced to 48 inches thick or 24 pounds 
to the cubic foot. At the end of eight days, with an average 
pressure of 244 pounds per square foot, it had shrunk a 
quarter more and weighed 31 pounds to the cubic foot. Ten 
weeks later, when the bottom layer weighed 50.7 pounds to 
the cubic foot, this layer weighed but 33.3 pounds. One had 
a pressure of 244 pounds and the other 323 pounds per 
square foot and the one with the lighter pressure is the 
heavier proportional to the pressure. 
The third layer from the bottom contained 9997 pounds 
fodder corn. An hour after it was put in, with a pressure 
of 25 pounds per square foot, it was 57 inches thick or 21 
pounds to the cubic foot. Eight days later, with an average 
pressure of 145 pounds per square foot, the layer was 39.5 
inches thick, 30.3 pounds per cubic foot. Here, again, the 
weight per cubic foot is not proportional to the pressure. 
It did not change from this weight, compressing only to 31.5 
pounds per cubic foot at the lowest. When the cover and 
upper layer were removed the top of this third layer rose 
two and a half inches, this being the amount that the whole 
mass of the three layers below expanded. This expansion 
seemed to be one inch for the first and third layers and half 
