104 HOW TO BUILD A SILO. ^ 



finished wall to permit the earth filled in behind to be 

 very thoroughly tamped, so as to act as a strong backing 

 for the wall. This is urged because a large per cent, of 

 the stone foundations of wood silos have cracked more or 

 less from one cause or another, and these cracks lead to 

 the spoiling of silage. 



Fig. 21. Shozving method of bedding iron rods in sloiu'. 

 brick, or concrete walls, to increase the strength. 



Flat quarry rock, like limestone, will make the strong- 

 est silo wall, because they bond much better than boulders 

 do, and when built of limestone they will not need to be 

 reinforced much with iron rods. It will be best even in 

 this case, however, to use the iron tie rods between the 

 lower two doors. (King.) 



