DIFFERENT TYPES OF SILO STRUCTURES. 31 



cerned, there is no difference when the silos are properly built. 

 The longevity of concrete and tile silos is usually greater than 

 that of wooden silos, since the latter are more easily attacked 

 by the silage juices and are apt to decay in places after a number 

 of years, unless special precautions are taken to preserve them. 

 A well-built and well-cared-for wooden silo should, however, last 

 almost indefinitely. 



As regards the form of the silo, it may be built in rectangular 

 form, square, octagon or round. We have already seen that the 

 most economical of these is ordinarily the round form, both be- 

 cause in such silos there is less wall space per cubic unit of 

 capacity, and in case of wooden round silos, lighter material can 

 be used in their construction. The only place where silos of 

 square or rectangular form are built now is inside of barns, where 

 they fit in better than a round structure. We shall later on give 

 directions for building silos inside of a barn, but shall now go 

 over to a discussion of the various forms of round silos that are 

 apt to be met with. More round wooden silos have been built 

 during late years in this country than of all other kinds of silos 

 combined, and this type of silo, either built of uprights lined in- 

 side and outside with two layers of half-inch boards, or of one 

 thickness of staves, will doubtless be the main silo type of the 

 future; hence we shall give full information as to their building, 

 and shall then briefly speak of the other forms mentioned which 

 may be considered preferable in exceptional cases. 



Round Wooden Silos. 



Round wooden silos were first described, and their use advo- 

 cated, in Bulletin No. 28, issued by the Wisconsin Station in 

 July, 1891, at a time when lumber of a good quality could be se- 

 cured at. much less cost than at present. This type has come to 

 be known as the Wisconsin or King silo, named after the late 

 Prof. King, the originator. The first detailed and illustrated de- 

 scription was published in the above bulletin; since that time 

 it has been described in several bulletins and reports issued by 

 the Station mentioned and in numerous publications from other 

 Experiment Stations. This type, and the one to be described in 

 the following, the stave silo, are practically the only kind of 

 wooden silos that have been built in this country during late 

 years except where unusual conditions have prevailed that would 

 make some other kind of silo construction preferable. 



