240 ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 



part cement and one part fine sand. This may be applied with 

 a whitewash brush. Keep the sun out and wet the inside once 

 or twice a day for a week. This makes a smooth and lasting 

 inner surface. 



Mixing the Concrete. 



The mixture which is practical to use in building a concrete 

 silo is one part cement, two parts sand, to four parts crushed 

 rock or very coarse gravel. In mixing it is best to have a fairly 

 accurate measure such as a wheelbarrow which will hold so 

 many shovels or by counting the shovels of sand, gravel and 

 cement used. The best way to thoroughly mix material is to 

 have prepared a well jointed mixing-board, then dump conven- 

 ient quantities of sand on the board. Put on the right amount 

 of cement and thoroughly mix with hoe or shovel. Put enough 

 water on to make this sloppy, then dump on the gravel or crush- 

 ed stone and turn at least twice with the shovel. The mixture 

 is then ready to use. 



TABLE NO. II. — Material Necessary for Concrete. 



Ht. Silo Inside Diam. Thickness Cement — Sand — Gravel or Stone 

 Feet Feet Wall — Inches Bags Cubic Yards — Cubic Yards 



20 



8 



6 



34 



2% 



5% 



20 



12 



6 



55 



4y 4 



8% 



20 



15 



6 



73 



5% 



11 



25 



10 



6 



54 



4 



8% 



25 



15 



6 



86 



6% 



13 



25 



20 



6 



122 



9% 



18% 



30 



10 



7 



73 



5% 



11% 



30 



15 



7 



115 



8y 2 



17 y 4 



30 



20 



7 



154 



n% 



23% 



40 



15 



8 



159 



12 



24 y 4 



40 



20 



8 



220 



16% 



33^4 



40 



25 



8 



283 



21% 



44 



