BUILDING THE SILO. 299 



The Floor. The floor may be of earth where 

 the soil is dry, of concrete covered with cement or 

 even without such a covering, or of bricks laid in 

 cement. (See Page 282.) Where the soil is dry 

 earth would answer well enough for a floor were it 

 not for the danger arising from depredations of rats 

 and mice especially the former. Because of this 

 danger, the propriety of making a floor secure 

 against such depredations should be carefully con- 

 sidered. 



The Staves. The staves should be of some 

 material that is relatively cheap and that is not too 

 difficult to obtain. At the present time, white pine 

 is probably the favorite wood in the northern states, 

 cypress in the southern states and the Douglas fir in 

 those of the far west. But other kinds of pine may 

 be used, as the red, the yellow, the Norway and the 

 southern, and also other soft woods, as spruce and 

 hemlock. It is important that the material shall 

 be sound and free from knots that are liable to drop 

 out, and seasoned lumber is preferable to that not 

 seasoned. 



The most suitable size for the staves will be at 

 least measurably dependent on the size of the silo 

 and the character of the climate. The larger the 

 silo the broader may the staves be, and the warmer 

 the climate the less is the thickness required. Six 

 inches may be named as the maximum limit for the 

 width of the staves and four inches as the minimum. 

 The usual thickness is two inches, but in mild cli- 

 mates one and one-half inches will suffice. Where 

 the material can be obtained at reasonable prices, the 

 staves should be as long as the silo is high, but since 



