Thirty-fourth Annual Convention. 225 



was filled, and after standing six weeks did not show the slight- 

 est sign of giving in any particular. 



In order to preserve the silo in good condition it is abso- 

 lutely necessary that the half-inch lumber with which the silo 

 is ceiled be protected from dampness. To this end the plaster 

 must be of good quality and kept perfectly water-tight by cement- 

 ing up any cracks that may appear, so that the wood shall receive 

 no moisture from the silage. The wall must also be ventilated, 

 for by allowing a free circulation of air between the sheeting 

 and the lining, the lumber will be kept dry. In this silo a two- 

 inch space was left at the top above the plaster and below 

 the plate. In this way the air was allowed free access to enter 

 from the bottom, between the outside covering and the inside 

 lining, and pass into the silo through the openings at the top. 

 These spaces were covered with heavy wire netting of one-third 

 inch mesh to keep out rats an dmice. (Cut 30). 



Theoretically the outside covering should be put on hori- 

 zontally, so that the strength of the material which forms the 

 cover might add to the strength of the silo. There are, however, 

 several practical difficulties in putting sheeting on in this manner. 

 The lumber cannot be more than a half -inch thick and spring to a 

 circle twenty feet or less in diameter, and any siding as thin as 

 this, which is carried in stock, is practically clear lumber and nec- 

 essarily high priced. Another difficulty is that the only half-inch 

 stuf¥ that can be purchased at the lumber yard, which will make 

 a water-tight cover, is common house siding. This, in order to 

 be sprung to a circle, must be rabbeted on the back side of the 

 thick edge so as to fit over the thin edge of the board below^ and 

 allow the siding to lie flat against the studs. Rabbeted siding 

 cannot usually be obtained at a lumber yard, and it i? extra trouble 

 and expense to have this work done at a mill. Another serious 

 difficulty in putting the siding on horizontally is that at the end of 

 each board there is a strong outward pull against the nail heads, 

 and as soon as the boards become slightly decayed at the ends 

 they are likely to pull ofT over the nails. ^ 



Owing to these objections and to the fact that it was our aim 

 to use, as nearly as possible, lumber that is carried in stock by all 

 lumber yards, it was decided to put hoops on the outside and 

 build them up of the same half-inch material as the inside sheet- 

 ing. This was done by using three thicknesses and breaking 



