SIZE OF THE SILO. 51 



may be actually forced away from the silage so that air 

 may enter from above; and even if this does not occur 

 the pressure against the sides will be so much lessened 

 above by the greater spreading below that if the walls are 

 at all open, air will more readily enter through them. 



In the round wooden silos every board acts as a hoop 

 and as the wood stretches but little lengthwise there 

 can be but little spreading of such walls, and in the casie 

 of stave silos the iron hoops prevent any spreading, and 

 it is on account of these facts that the round silo is 

 rapidly replacing every other form. 



After the silage has once settled, there is no lateral 

 pressure in the silo; cases are on record where a filled 

 silo has burned down to the ground with the silage re- 

 maining practically intact as a tall stack. 



Other points of importance in silo building which do 

 not apply to all kinds of silos, will be considered when 

 we come to describe different kinds of silo structures. 

 Several questions present themselves at this point for 

 consideration viz., how large a silo shall be built, where 

 it is to be located, and what form of silo is preferable 

 under different conditions? 



On the Size of Silo Required. 



In planning a silo the first point to be decided Is 

 how large it shall be made. We will suppose that a 

 farmer has a herd of twenty-five cows, to which he wishes 

 to feed silage during the winter season, say for 180 days. 

 We note at this point that silage will not be likely to 

 give best results with milch cows, or with any other class 

 of farm animals, when it furnishes the entire portion of 

 the dry matter of the feed ration. As a rule, it will not 

 be well to feed over forty pounds of silage daily per head. 

 If this quantity be fed daily, on an average for a season 

 of 180 days, we have for the twenty-five cows 180,000 

 pounds, or ninety tons. On account of the fermentation 

 processes taking place in the silo, we have seen that 



