SIXTH ANNUAL YEAR BOOK— PART VIII. 753 



The method of construction heretofore has in most cases been cumber- 

 some, requiring a large amount of lumber to construct the forms. 



BRICK SILOS. 



Where brick is cheap and stone and gravel scarce, a brick silo may 

 be the most economical. In large brick silos the wall is usually built 

 with three or four courses of ^ brick at the base and made a course 

 thinner at various heights until reaching the upper ten feet, which need 

 not be more than eight inches thick. The silo rests upon a seven-foot 

 stone foundation 18 inches thick; six feet of it being below the ground. 

 Upon this are laid three courses of brick, the middle course being of brick 

 liie which contains a dead-air space and thus prevents freeing to a great 

 extent. This wall extends twelve feet above the foundation and from 

 that point to the top, two courses of brick are used with one and a half 

 inch air space between. One silo 16feet in diameter and 30 feet deep, 

 built in this manner, holds 120 tons and costs $250, or $2.08 perton. An- 

 othersilo of the same depth and 19 feet in diameter holds 168 tons and 

 cost $5B0, or $2.08 per ton, the same as the smaller silo. 



STAVE SILOS. 



There are cases where a cheap, temporary silo may be economical 

 and of great advantage, for example, a farmer may expect to build a 

 new barn in a different place and want a silo near the old barn for ai 

 few years only; or a renter may wish a temporary silo and then if he 

 moves in a short time he can take the lumber from a stave silo with him. 



The objections to a stave silo are that the staves shrink during' 

 dry weather when the silo is empty and unless the hoops are tightened 

 there is a possibility of the silo being r-acked or blown over. If the 

 hoops are tightened when the staves are dry, there is then danger of 

 the hoops bursting when the silo is filled and the staves again become 

 saturated with moisture. An example of this came under the writer's 

 notice recently when the second morning after a silo was filled, the 

 owner found half the hoops had burst. It will be noticed in the illus- 

 trations of stave silos that where they had been put up for any length 

 of time the staves had shrunk allowing the hoops to drop from their 

 original position. . A stave silo is usually much more satisfactory if a 

 building is built over it for protection, but this makes it expensive. 



Cut 32 shows a stave silo recently built. This silo is 16 feet in 

 diameter, 34 feet deep, and has a capacity of 1.50 tons. The foundation, 

 which exten'ds two feet into the ground, is a brick wall that was laid 

 up by the owner. , The silo was built by two carpenters in nine day* 

 at $2.50 a day each, making $45 paid out for labor. The lumber co«t $80, 

 the iron hoops $20. and nails and spikes $2. There being no ro©f the silo 

 above the foundation cost, including labor, $147. If the brick had been 

 purchased and the labor of excavating for the foundation and laying the 

 brick charged for, the total cost of the silo would have been approxi- 

 mately $170 without a roof, or $1.13 pea ton. 



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