EXPERIMENT STATION BULLETINS. 263 



these silos that have been in use for five years and was unable to dis- 

 cover check or flaw indicating that this judgment is correct and, 

 furthermore, it appears that not one of the 25 or more silos of this con- 

 struction has shown evidence of such weakness. 



A FEW COMPARISONS. 



The relative merits of the solid wall silo and the cement block silo 

 have not been discussed and little need be said upon this point. Both 

 types of silos are in successful operation. Unless proper care is exer- 

 cised in construction to make the walls air tight, neither can be expected 

 to produce good ensilage. There is probably no foundation for the 

 opinion that the ensilage produced in a cement silo is more acid than 

 that produced in a wooden one, because the '^cement silo is colder than 

 the wooden one." A series of temperature determinations show that 

 the heating in the cement silo is as great as it is in the wooden silo. 

 If it be true that the acidity is greater in the cement silo, some other 

 explanation must be sought. 



At the present time the cement block silo is more popular than the 

 solid wall cement silo. Two reasons may be assigned for this fact : 



1st. The expense and labor entailed in building forms for a solid 

 cement wall are considerably greater than in building a form for mak- 

 ing cement blocks. When forms are built for a single solid Avail cement 

 silo this difference in expense is magnified. This observation does not 

 hold where the professional silo builder is employed. 



2nd. The work of constructing the cement block silo seems to be 

 more attractive than that of constructing the solid wall silo. 



We shall find generally that in the home made silo the block wall 

 is better and more symmetrically constructed than is the solid wall. 



MATERIALS NEEDED FOR THREE DIFFERENT KINDS OF SILOS. 



That the reader may have some basis for comparison in estimating 

 the cost of difterent kinds of silos the following approximate figures are 

 given for a silo 12 feet inside diameter and .30 feet high : 



STAVE SII-O. 



The inside circumference of such a silo is 37 feet S^/o inches. If 2 

 feet is left for doorway and tlie adjacent staves are used for door frame, 

 then .35 feet Si/o inches divided by the width of stave used will give the 

 number of staves required for one course of staves. If the staves for 

 the two courses be 14 feet and 16 feet long respectivel}^ and 5% inches 

 wide, there will be required 75 staves 14 feet long and 75, 16 feet long. 



There will be required also 14 hoops of i/> inch or % inch round iron 

 with lugs. 



ALL WOOD SILO. 



Frame : 



For sills (one thickness of 2 x 4) and for plates (two thicknesses of 

 2 X 4), 9 pieces 2 x 4, 14 feet long. 

 For studs: 



38 pieces 2 x 4, 14 feet long. 



38 pieces 2 x 4, 16 feet long. 



