270 ILLINOIS STATE DAIRYMEN'S ASSOCIATION. 



A patented opening silo roof is sold with the Philadelphia 

 stave silo. It is so constructed that the eight sections can be 

 opened up to an almost vertical position above the silo wall. 

 These sections are connected with pieces of canvas which when 

 the roof is closed hang inside of the silo. The advantage of 

 this construction lies in the fact that the silo can be filled more 

 than full, furnishing an almost full silo after settling. 



As already stated, the silo door should form an air tight 

 joint with its frame and be flush or smooth on the inside. In 

 addition, it should be convenient for the removal of silage and 

 of a size to permit any person to enter the silo. Most patent 

 silos are now provided with continuous doors which are only 

 obstructed by the hoops or bars extending from side to side. 

 Often these connections or hoops are so close together that 

 the so-called continuous door is of little advantage over doors 

 of larger size placed in the silo wall at intervals above one an- 

 other. 



In stave silos the doors are usually made of the same ma- 

 terial as the silo itself. Short sections of the staves are usually 

 fastened to cleats of the same curvature as the silo. The 

 doors rabbeted at top and bottom and rabbeted or beveled 

 at the sides to fit together and into the door frame. Various 

 patented devices are used to hold the doors in place. Con- 

 crete silos are now in use which have the doors located spirally 

 above the silo. The idea of such an arrangement is to avoid 

 a vertical line of weakness. This is an unnecessary precaution, 

 as many silos with the doors directly above one another have 

 been in use for years and no cracks have developed. By using 

 the same amount of steel between the doors as is used in any 

 other vertical section of the wall, there is no more danger of 

 failure between the doors than at any other place in the silo. 

 The location of doors in this manner does not permit of the 

 usual chute through which the silage may be dropped and 

 which is almost essential. 



