ROOF AND FOUNDATION. 107 



The Metal Silo Roof. The roof adds greatly to the appear- 

 ance of the metal silo and protects it against undue wind strain 

 or vibration. In northern climates it acts as a protection against 

 snow and freezing, and in warmer zones against the extreme 

 heat of the sun which would cause considerable loss between 

 feedings. It is an added expense, of course, and as rain is not 

 injurious to silage the roof is considered superfluous in some 

 sections of the Southwest. The permanent roof also prevents 

 tramping or filling to the top of the silo, causing both spoilage 

 and loss of capacity. Despite these objections, however, the 

 majority of purchasers seem to prefer the roof. 



Foundation. Too much care cannot be taken in building the 

 foundation of a metal silo. SeHd ground is the first essential be- 

 cause the silo with its contents is very heavy. The foundation 

 wall and floor should be of concrete of ordinary 1:2:4 propor- 

 tions. The wall should be at least 12 inches thick and extend 

 6 inches below freezing point or about 3 feet in the ground deep 

 enough to prevent the frost from heaving the silo out of level 

 and to prevent rats from digging under. The first row of metal 

 sheets should be imbedded in the center of the wall at least 12 

 inches deep. 



Freezing in Metal Silos. In extremely cold climates silage 









Fig. 49. Large Metal Silo on Sunny Slope Farm, Emporia Kas. 

 being filled with Silver's Ohio No. 22 Cutter. 



