2SS Report of the Di:rAnTMENT of Entomology op tub 



sides, as sliown by IMaLe XLII. On llio inside of llie fronl. and 

 top a strip projects two inches, against vvliicli the adjustable side 

 rests when in position. Plate XLII, a. Two light strips extend 

 across the top to support the canvas. On two sides of the frame 

 and outside of the canvas two stout strips are bolted on a con- 

 venient distance from the ground to serve as handles used in 

 carrying the fumigator, as in Plate XLIII. The fourth side is 

 made of the same material as the frame, and fits snugly in place 

 against the two-inch' flange previously referred to. 



The frame is covered with any suitable gas-tight mialciinl. 

 Eight-ounce duck was used on the two fumigatore tested. It 

 was sewed together in such a way that the three sides were 

 covered with one large, slieet. In one case raw oil and white lead 

 were used to malce the canvas gas tight, and in the other shellac 

 with one coat of oil and white load. Any of the substances used 

 in malving gas-tight tents will answer the same purpose. As it 

 is desirable to have the canvas dark in color, lamp black was 

 mixed with the oil in both cases. Heavy, unbleached sheeting 

 is cheaper than canvas, weiglis less and being thinner and closely 

 woven takes less material to make it gas tight. With ordinary 

 care in handling there is little danger of tearing the covering, 

 especially if it is made of material as strong as eight-ounce duck; 

 but as a precaution a stout wire net may be tacked on the inside 

 of the upper half of the fi'ame, thus preventing the limbs of the 

 trees from touching the canvas. 



A strip of canvas one and one-half feet wide is securely tacked 

 to each side of the base of the frame. The strips lap at the cor- 

 ners, so that when the fumigator is in place they lie flat on the 

 ground and can be covered with dirt or sand bags, thus prevent- 

 ing the escape of the gas. The strips can be hooked up out of 

 the way when the fumigator is being carried from one tree to 

 another. Plate XLIII. The movable side of the fumigator can 

 be easily put in place or taken off. Four handles, shown at Plate 

 XLV, are conveniently placed for use. The two-inch flange 

 against which it rests is covered with a good quality of felt 

 about one-fourth of an inch thiek, glued on as well as tack(;d, to 



