THE IOWA SILO 69 



sonably clear, stiff lumber. These are shown by the dotted 

 line A. At the ends of these and flush with the bottom 

 of each are securely nailed 2-inch pieces, B, of convenient 

 length. Thus the bevel at the end extends through three 

 2-inch pieces instead of one, and furnishes ample bearing upon 

 the supporting pins, N. Instead of resting upon pins, the 

 scaffold is sometimes hung by means of clevises and short 

 chains. There should be at least 34 mc h of clearance all 

 around the post, M . This framework is held together at the 

 corners by an eye bolt passing through a 2x6, four feet long, 

 approximately (L shown beneath at the right-hand corner) 

 and by the outer planks above. The eye bolts should be 

 made of % inch metal with a washer at each end. The diam- 

 eter of the eye should be 1 inch inside. Four are required. 

 A 2x8 or 2x6, F, is bolted at each end to blocks which in 

 turn are nailed to the middle of the two opposite members, A. 

 Upon this framework is placed a 2x10, indicated by (r, lying 

 flat across the center of F and the two members, A. - Extend- 

 ing at right angles from G and lengthwise but not central 

 upon F are two 2xlO's, indicated by H. A block is nailed 

 under the longer 2x10 not supported by F, and nailed to the 

 inner end of these timbers, H, are blocks which extend two 

 inches under G. By placing these blocks on each side of F, 

 it is not necessary to nail H to F. It is highly desirable in a 

 scaffold which must be used repeatedly that no nails should 

 be drawn when taking it apart. Upon the corners of and 

 diagonally to this frame are laid, inside of D, two widths of 

 2x12 planks, lettered /; and connecting the ends of these and 

 resting upon the ends of G and H are three 1x12 boards, five 

 feet long, lettered J, beveled at the corners to fit the circle; 

 also five 1x12 boards, lettered K, which are not beveled. 

 The four 1x12 boards, lettered R, complete the upper part of 

 the platform. 



