126 



CONCRETE OR CEMENT SiLOS. 



out to the curvature of the circle. These are placed hori- 

 zontally as girts and the short planks P are set vertically 

 nailing them to the girts, LU. The form 41 B is made in 

 the reverse of 41 A. 



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

 and 6 to 12 inches from it depending on the thickness de- 

 sired for the wall, and the concrete is filled in between the 

 forms." 



A Oute/de Form 



. Inside Form 



Fig. 41. Illustrates method of making form for construct- 

 ing concrete walls. The forms are made of plank and are 

 made in sections 4 to ip feet long, requiring 5 to 8 sec- 

 tions to complete the circle. 



Courtesy Wisconsin Experiment Station. 



