RECENT WORK WITH HYDROCYANIC ACID GAS 217 
Station. ‘This fumigator is about 111% feet high and 
8% feet in diameter. As shown in Fig. 82, it is six- 
sided and is intended to fold up when not in use. 
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FIG. 80—THE SIRRINE TYPE OF FOLDING FUMIGATOR 
Each of the six sides is retangular and rigid. They 
are fastened together by hinges. When in use the 
whole fumigator is made rigid by a series of cross- 
braces. ‘The top is held in place by a series of hooks. 
