Cyanide Gas Remedy for Scale Insects. 



445 



with chaiig'ing' poles. Essentially an upright is a changing pole 

 rigged with pulleys and having a braced cross-piece at the bottom to 

 prevent slipping. It should be four to six feet long-er than the 

 highest tree. The main pole should taper from about 2-| x 4 inches 

 at the bottom to 1^ x 4 inches at the top. Cross-pieces, 1 x o inches 

 and 6 feet long, are spiked or bolted to each side a few inches from the 

 l>ottom ; and 2x4 inch brace-pieces, spiked or bolted in place, are 

 used to hold the cross-pieces firmly at the right angle. The base of 

 the upright is thus a triangle-shaped frame, with the main pole 

 arising through its middle. The ends of the main pole and of the 

 braces project a few inches below the cross-frame and act to keep the 

 structure from slipping on the ground when it is raised. A f-inch 

 or thicker guy-rope 35 to 50 feet long is attached to the top of the 

 upright. About 75 to 90 feet of similar rope is needed for tackle. 

 This rope is passed through a fixed pulley-block .secured at the top of 

 the upright, then through a swinging pulley-block and thence back 



V\<',.l. — ('lia)i(iing Poles. — V(\\)ii of rwu simple types. The end of the one at left 

 is narrowed for insertion in a rope loop attached to the "catch place" on 

 the sheet. The end of the other is merely rounded; it is shoved under the 

 sheet and held in position by a half hitch of the guy rope as shown by the 

 sketch at the right. The any ro]ic may be tied aliout a groove in the' pole 

 or knotted through a hole. 



to the top, where it is firinly attached. The sM'inging block must 

 liave a hook. 



Four men at least are needed to place a sheet over a tree with 

 the uprights. Thje sheet is first thrown down back of the tree and 

 the catch-places naade ready if not in place. The uprights are laid 

 parallel, one on each side, with the tackle towards the tree, the feet 

 in a line near the middle of the tree, and the poles near enough so 

 that when raised they will just pass. Two of the men hold the ropes 

 and foot the poles while the other two raise them, as they would 

 ladders, to the vertical. The two on the feet next steady the poles 

 while the other two connect the tackle with the catch-place loops ; the 

 latter two then take the guy-ropes and, running forward, hold the 

 tops of the poles steady while the two at the feet haul away on the 

 tackles which, rising, carry the front of the sheet upward and forward. 

 When it is raised sufficiently above the tree, the tackles are held 

 taut, and the tops of the poles pulled forward by means of the guy- 

 ropes until enough cloth is over the top to cover the front side; the 



