42 HOW TO BUILD A SILO. 



of the most serious mistakes in the early construction of wood 

 silos was the making of the walls \vith dead-air spaces, w r hich, 

 on account of dampness from the silage, led to rapid "dry-rot" 

 of the lining. 



In the wood silo and in the brick lined silo it is important to 

 provide ample ventilation for the spaces between the studs, as 

 well as for the roof and the inside of the silo, and a good method 

 of doing this is represented in Fig. 4, where the lower portion 

 represents the sill and the upper the plate of the silo. Between 

 each pair of studs where needed a l^-inch auger hol.3 to admit 

 air is bored through the siding and sheeting and covered with 

 a. piece of wire netting to keep out mice and rats. At 'the top of 

 the silo on the inside, the lining is only covered to within two 

 inches of the plate and this space is covered with wire n tting 

 to prevent silage from being thrown over when filling. This 

 arrangement permits dry air from outside to enter at the bottom 

 between each pair of studs and to pass up and into the silo, thus 

 keeping the lining and studding dry and at the same time drying 

 the under side of the roof and the inside of the lining as fast as 

 exposed. In those cases where the sill is made of 2x4's cut in 

 2-foot lengths there will be space enough left between the curved 

 edge of the siding and sheeting and the sill for air to enter so that 

 no holes need be bored as describ d above and represented in 

 Pig. 4. The openings at the plate should always be provided and 

 the silo should have some sort of ventilator in the roof. This 

 ventilator may take the form of a cupola to serve for an orna- 

 ment as well, or it may be a simple galvanized iron pipe 12 to 24 

 inches in diameter, rising a foot or two through the peak of the 

 roof. 



A word of caution is sounded in the Wisconsin Bulletin No. 

 125 regarding the above method of ventilation: 



"It will be readily understood that if these ventilators between 

 the studs are left open in winter they will act as chimneys: they 

 will maintain a constant draft, between the studding, which will 

 cool off and freeze the silage more severely than it would if there 

 were no sheeting at all outside the studding. If the silage is for 

 winter feeding, and 99 per cent of the silage is so fed, then more 

 care should be exercised than at present in Wisconsin to prevent 

 this severe freezing. In order to do this, provision must be made 

 for closing these ventilators both at the top and at the bottom, 



