248 STATE BOARD OF AGRICULTURE. 



Forms are used in its construction, but the wall is rendered "hollow"; 

 first, by the use of forms and 2nd, by the building into the wall of tiers 

 of No. 2 3-inch drain tUes. Fig. 9 represents a horizontal cross-section 

 of the wall. It shows not only the arrangement of the tile and other 

 hollow spaces but also the outer and inner forms, the plan of the door 

 frame, and the manner of reinforcing the walls with the wire cables. 

 The hollow spaces formed by the tile and by the forms are continuous. 

 The tiles begin six feet above the foundation, form spaces lying beloAv 

 the tile. The form-spaces are continuous from foundation to top of 

 Avail. The inner form (see Figs. 9 and 10) was built of 2 inch by % 

 inch by 26 inch pieces of pine, nailed upon two circles of elm. Each of 

 these circles w^as built up of 2 inch by 3 inch pieces, breaking joints 

 with % inch by 3 inch pieces. All of these pieces were cut to circles 

 of proper radius. 



The outer form (see Figs. 9 and 11) was built of 5 inch x l^ inch 

 sheeting tacked to perpendicular ribs 1 inch x 1 inch, placed 1 foot 

 apart. This form is reinforced by 2 inch x i/o inch strips nailed out- 

 side and at the ends of the ribs. These forms were clamped into place 

 by means of two i/^ inch bolts in each form as shown in Fig. 9. 



The frame for a continuous doorway (Fig. 9) is made of 2i/2 inch 

 s 6 inch oak bridp;e timber with a 1 inch x II/2 inch strip on the inner 

 edge against the cement, which strip acts also as a shoulder for the 

 doors. An inch strip on the outside of the 6 inch piece makes the thick- 

 ness of the door frame equal to the thickness of the wall. Cross pieces 

 of the same 2^2 inch materials are set in the frame three feet apart, 

 center to center. The inside width of the frame is 22 inches. The frame 

 thus constructed was set up so that the sill stood one foot above the 

 foundation, properly braced, and so was built into place. 



For reinforcement, wire cables were built into the wall at intervals 

 of 18 inches. The manner of stretching the cables is shoAvn in Fig. 

 9. In the lower wall, four No. 7 wires were twisted together for this 

 purpose; in the upper wall, two No. 7 or No. 9 wires were twisted 

 together. 



Fig. 13 shows the scaffolding and forms used in the construction of 

 the silo. Four posts were set up at quarters about the silo. The oppo- 

 site posts were tied (nailed) together by cross or tie beams. From 

 these cross beams were suspended the forms (outer and inner) by chains 

 or wires. 



To lift a form, four wire fence stretchers were wired or chained to 

 the cross beams, one near each post. Chains fastened to the form were 

 clutched by the stretchers and drawn tight. The form was then un- 

 damped and lifted to the proper height by the use of the stretchers. 

 This was usually done by placing a man or a boy at each stretcher and 

 having all work in unison. Or if one man did the lifting, he passed 

 from stretcher to stretcher, in order, giving to each one or two strokes. 

 When the form was raised to the proper height, usually 24 inches, it 

 was suspended by chain or wire to the cross-beams and properly 

 clamped. The outer form should be clamped first always, because the 

 clamping of the inner form into place before the outer form was so 

 clamped would be likely to crack the unseasoned wall. The inner form 

 supported the platform upon which the men worked. 



