28 PRACTICAL SILO CONSTRUCTION 



the braces g g, as shown in plan. The number of 

 these clamps must be determined by the diameter 

 of the circle, but should never be less than two, 

 placed between each clamp at the quarter segment 

 of circle; nor, when the 24-gauge sheet steel is em- 

 ployed, should they be more than 36" apart on the 

 outside circumference of circle. 



The strips shown at h h in Fig. 4, cut along one 

 edge in a convex form, may be employed to keep 

 the sheet steel from bending under the weight of 

 the concrete. These are cut in the proper segment 

 of circle so that they will fit between each clamp, 

 around the inside circumference of your circle. 

 Those shown at i i are cut in a concave form and are 

 fastened to the outside circumference of your circle, 

 between clamps. By using these retaining strips, 

 or pieces of strap, iron bent into the same form and 

 riveted to the sheet steel, the lighter weight steel 

 may be employed. Thus, with three of these re- 

 taining strips between each clamp, No. 28-gauge 

 sheet steel has been successfully employed for the 

 forms or centering. 



The value of employing the retaining strips and 

 using a lighter grade of sheet steel is that the forms 

 will thus be made lighter, as the 24-gauge sheets 

 weigh about 17 pounds to the sheet of 24x101"; the 

 26-gauge weighs 13 pounds to the sheet, while the 

 27-gauge weighs 111 pounds, and the 28-gauge 

 weighs but 10J pounds to the sheet. This is also 

 able to effect a saving in the cost of the forms, as 



