SILOS AND SILAGE. 



21 



so as to fit in a circle. When complete, set up and bolt together in a circle, placing 

 the inner form first. Bolt securely through the ends of the sectional forms by means 

 of short pieces on top. To keep the inside form just 6 inches from the outside form, 

 make several pieces 6 inches long as spacers. 



Fig. 14. Showing the method of laying out the forms. 

 MIXING THE CONCRETE. 



The concrete should be prepared on a smooth, water-tight mixing-board, about 

 10 x 12 feet in size. A suitable mixture for silo-construction is 1 part cement, 2 parts 

 sand, and 4 parts coarse gravel, commonly known as 1 to 6. The most convenient 



Fig. 15. Silo forms. 



method of measuring is by means of the bottomless box. The gravel or stone used 

 should be clean and free from any foreign substances which destroy the action of 

 the cement. After adding the cement to the gravel and sand, mix thoroughly by 

 shovelling, then add sufficient water and shovel again back and forth at least three 



