Essential Features of Silos. 



395 



In circular silos the pressure is sustained by the tensile 

 strength of the materials in the walls, which gives them the 

 greatest possible advantage. 



FIG 195. Illustrating how the bulging of rectangular wooden silo walls 

 allows air to coine down the sides between the walls and the ^ilage, 

 causing it to spoil. The amount of spreading is exaggerated in the 

 figure for clearness of illustration, but it is none the less real. * 



492. Silo Placed Deeply in the Ground. In most cases it 

 is best to allow the silo to extend as deeply into the ground 

 as convenience in removing the materials will permit. This 

 can always be as much as 3 feet below the feeding floor and 

 in the case of bank barns where the silo can be placed in the 



