PRACTICAL SILO CONSTRUCTION 41 



The plastered silo may be constructed with a con- 

 tinuous air-chamber by attaching the wire lath to 

 the outside and also to the inside of the |" rods. 

 By plastering upon each side a space is left between 

 the plaster coats that is a preventative against frost 

 in the silo. 



CONCRETE BLOCK SILOS 



Silos of concrete blocks, or units, have been em- 

 ployed so generally that a description of this type of 

 construction is not needful to the average concrete 

 contractor. The manufacturers of concrete block 

 machines put out a silo block machine for molding 

 hollow building blocks for any diameter of silo, thus 

 making the construction of the units the same as the 

 manufacture of building blocks for any type of wall. 



For the man who desires to make his own blocks, 

 the type of mold shown in Fig. 8 is of value, as this 

 molds a wet process hollow block. The molds are 

 easily constructed by using two planks for the sides. 

 In width these should be about 2" more than the de- 

 sired width of block (or thickness the wall is to be) 

 at the points where the desired height of each block 

 is measured. The planks are cut with a saw kerf 

 for 3 " in depth. These are to receive the sheet iron 

 dividing plates between the blocks, as illustrated. 

 A convex form is built for the bottom of mold from 

 wood strips, cut into the proper curve for the seg- 

 ment of circle the block is to take, on the inside of 

 silo. These strips are covered with sheet iron, and 



