38 SILOS: CONSTRUCTION AND SERVICE 



secure good material and have it put together in a work- 

 manlike manner, as in any other masonry silo the work- 

 manship is very important, even more so than in a wooden 

 silo. 



Interlocking Block Silos. There are on the market 

 several kinds of interlocking devices for silo building blocks. 

 In general this depends, in one way or another, upon the 

 tensile strength of the blocks taking care of the outward 

 pressure of the silage. If the proper amount of steel is used, 

 these silos become safe; otherwise, too large a percentage of 

 them burst, as masonry can not be depended upon to with- 

 stand a pull. If a sufficient amount of steel is used the inter- 

 locking devices become an unnecessary expense. 



