CONTINUOUS DOORS FOR SILOS. S9 



Wisconsin, Illinois and Michigan. The total cost included ma- 

 terial, labor, superintendence and all miscellaneous expenses in- 

 curred in preparing the silos, ready to receive the crops. Where 

 sand and gravel were obtained on the farm the expense of haul- 

 ing plus fair price for materials was included. The average 

 cost of the 78 silos was $2.30 per ton capacity. The 20 silos 

 having capacity 100 tons or less cost J2.89 per ton. 32 silos with 

 capacity from 100 to 200 tons cost $2.38 per ton. The remaining 

 26 silos having capacity of more than 200 tons each, cost $2.18 

 per ton capacity. 



|l Rods plj\ced Z 



tT TYING ffOOF 



iiVAt-u.rroos 



Fig. 30. — Showing method of tying roof to wall, and of rein- 

 forcing across door opening. 



— Courtesy Wisconsin Bulletin No. 214. 



We quote from Bulletin No. 125 of the Wisconsin Station. 



"A common type of form used in making a continuous wall 

 or monolithic structure is illustrated in Fig. 31. A is the outside 

 form and B the inside form. These forms are made as segments 

 of the circle 6 or 10 feet in length and 1% to 3 feet deep. A 

 form is made by, taking two pieces of plank 2x12 or 2x14, LL, and 

 UU, Fig. 31 A, sawing them out to the curvature of the circle. 

 These are placed horizontally as girts and the short planks P are 

 set vertically nailing them to the girts, LU. The form 31 B is 

 made in the reverse of 31 A. 



"In building the wall, form B is set inside of form A and 6 to 

 12 inches from it depending on the thickness desired for the wall, 

 and the concrete is filled in between the forms." 



The building of a concrete silo involves careful attention to 

 the construction and proper bracing of the forms or moulds, and 

 to the reinforcing and the bonding of the various courses. It is 

 therefore suggested that unless a farmer has had some experience 



