288 SOILING CROPS AND THE SILO. 



Doors in Silos. — Whatever the nature of the 

 silo the doors have some features in common. These 

 inchide the following: i, They should usually 

 be placed one above the other and on that side of 

 the silo contiguous to the passageway. There 

 may be instances in which it may be necessary to 

 have doors on the opposite side of a large silo, but 

 these will be infrequent. 2, The aim should be 

 to confine the number of the doors within the limits 

 of strict necessity because of the difficulty of exclud- 

 ing air at the openings thus made. 3, When it 

 can be made so, the door inside should have a beveled 

 rim fitting into a corresponding bevel on the door 

 when the door is in place. The bevel on the door 

 should be from the inner rim outward. When a 

 door is thus beveled the greater the pressure of the 

 silage against it the more perfectly will the air be 

 excluded. Other peculiarities of construction will 

 be referred to when discussing the various forms of 

 silos described in Chapter IV. 



Roofing Silos. — When built inside of a barn or 

 stable it is not necessary to provide a roof for silos. 

 When built without, and more especially in climates 

 subject to frequent and also to prolonged storms, it 

 will probably prove more satisfactory in the end to 

 provide some form of the same, and the materials 

 to be used will be dependent to a considerable degree 

 on the form of the silo. These will be enlarged 

 upon when the details of construction in the various 

 forms of silos are discussed. 



But it does not seem to be necessary under all 

 conditions to provide even outdoor silos with a roof. 

 The opinion prevails that not to do so would result 



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