PRACTICAL SILO CONSTRUCTION 35 



draw the wall from the vertical or plumb line. With 

 this form of post the concrete floor may be laid in the 

 bottom of the silo, and the uprights set upon same 

 without injury. By keying or bracing this securely 

 at the bottom, and staying the top of the post with 

 guy wires, the walls of silo must be built absolutely 

 plumb, for the forms cannot be raised in any other 

 manner. This "fool-proof" feature will be of in- 

 terest to the contractor who must intrust his work 

 to others ; and, as mistakes in this work are costly, 

 every safeguard against errors is of great impor- 

 tance. 



This style of form permits the placing of any re- 

 inforcement desired. The upright rods are placed 

 with the first course of concrete, spacing them the 

 proper distance apart. These are held in a vertical 

 position by braces nailed to the top of the center 

 posts until the wall has advanced enough to hold 

 them securely. Then the braces can be removed, to 

 finish the silo. 



By nailing short strips to the center posts, hori- 

 zontally, a ladder can be made for convenience in 

 reaching the forms at every stage of the construc- 

 tion. 



USING AUTOMATIC CLAMP 



The illustration at Fig. 6 shows the use of the 

 automatic wall-clamp, explained in CONCRETE WALL 

 FORMS of this series, as adapted to silo work. This 

 permits the molding of a hollow wall with a continu- 



