THIRTY-FIFTH ANNUAL CONVENTION. 267 



Drainage. 



This subject is of great importance and should receive 

 more consideration than is usually given to it in the construction 

 of farm buildings, and especially of masonry silos. Any soil will 

 support a greater load when dry than when wet. This is es- 

 pecially true of clay. The heaving action of frost is due en- 

 tirely to the moisture contained in the soil, which expands 

 with an almost irresistible force upon freezing. For these con- 

 siderations, unless the foundation lies in dry, well drained soil, 

 a drain tile should be used to remove the ground water. To 

 assist the water in getting into the drain, the foundation and 

 floor may be placed upon a bed of gravel or cinders. If gravel 

 or cinders are used, they should be well tamped before the foun- 

 dation is put in place. 



Under certain conditions, the silo floor may be dispensed 

 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 under- 

 mining by rats, the floor may be omitted. In general, how- 

 ever, a floor is quite desirable. The portion of the silo below 

 the ground may be made more nearly water tight, the floor 

 may be thoroughly 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 distributed 

 evenly over the surface and would be just as firmly supported 

 if the floor was not used. A concrete floor of the usual side- 

 walk construction, 4 to 6 inches in thickness, will be very satis- 

 factory. If properly mixed sand and gravel can be obtained, 

 one part of cement to five parts of sand and gravel will be 

 about the right proportion to use. The concrete should be 

 thoroughly tamped and troweled. 



The Roof. 



Perhaps the greatest advantage of a roof is the lessened lia- 

 bility of the silage freezing. Not only is it impossible to pre- 

 vent freezing in severe weather unless the silo is provided 



