60 Concrete Silos 



If a floor is to be put in, the excavation should be 

 carried down to 4 inches below the top level of the 

 floor, making a 4-inch slab. 



Under certain conditions, the silo floor may -be dis- 

 pensed with without interfering with the preservation 

 of the silage. Where the silo rests upon dry clay or 

 any non-porous soil, and where the foundation is deep 

 enough to prevent undermining by rats, the floor may 

 be omitted. In general, however, a floor is quite de- 

 sirable. The portion of the silo below the ground may 

 be made more nearly water tight, the floor may be thor- 



Sweep for Laying Out Excavation. 



oughly cleaned, and there is no mixing of earth with 

 the silage. A silo floor need not be thick or expensive, 

 as the weight of the silage, though very great, is dis- 

 tributed evenly over the surface and would be just as 

 firmly supported if the floor was not used. 



After the excavation is leveled off for the floor of 

 the silo, the digging is then continued around the cir- 

 cumference of the pit for an additional depth of 8 

 inches, and 24 inches in width, to provide for the foot- 

 ings, as shown in the drawing. It is a good plan to 

 provide in the center of the silo floor a connection with 



