220 AGRICULTURE OF MAINE- 



joint in the barn. He soon fonnd, however, that there was a 

 great tendency for the silage to spoil in the corners of the silo, 

 and also for the walls to separate at the corners. He attempted 

 to remedy this by cntting off the corners, making the octago- 

 nal silo. The round silo followed quickly, and is today, for 

 obvious reasons, the most satisfactory type to build. It is true 

 that today there are in Maine many square silos giving good 

 satisfaction and possibly there are places in which it would be 

 advisable to build them, but this does not apply to average con- 

 ditions. 



Advantages of a round silo over a square or rectangular one : 



1. The round silo requires less lumber. 



2. The round silo is easier to reinforce. 



3. There is less difficulty in filling, as no corners have to 

 be cared for. 



4. The silage settles more evenly and compactly. 



The materials used for building silos are : 



1. Wood — (a) single thickness, stave; (b) two or more 

 thicknesses, with air space, as King, Gurler, or Wisconsin type. 



2. Stone — usually single wall. 



3. Brick — either single or double wall. 



4. Hollow tile. 



5. Concrete — (a) monolithic or one-piece; (b) blocks. 



Of these materials, stone and brick may be disregardetl under 

 most Maine conditions, for on account of the extra cost to 

 build them another type is chosen. The cost of double wall 

 wooden silos is nearly as much as that required to erect a con- 

 crete silo. Further, they are not as permanent, and require 

 much more care while they do last. 



A hollow tile silo can be built without the use of the forms 

 necessary for concrete. From what few figures I have been 

 able to gather, the expense is slightly greater than for concrete, 

 but the silo could be built where gravel is not readily obtained. 

 Hollow tile are worthy of further investigation. 



Thus discarding these materials for the reasons named, we 

 have staves, concrete, and concrete blocks for silo construction. 

 Time forbids the extended discussion of all three of these, 



