70 



THE MONTHLY BULLETIN. 



ured off into its graduate and a corresponding amount of sulfuric acid 

 is measured into its graduate. By throwing both levers into the proper 

 position, the measured cyanide and acid will tlow simultaneously from 

 their respective graduates through pipes into the main generating cylin- 

 der. Directly under the discharge pipes is a leaden bowl to effect a 

 complete mixture of the cyanide and acid. The main generating cylin 

 der is provided with a two-inch opening attached to which is a hose long 

 enough to conduct the generated hydrocyanic acid gas into the fumiga- 

 tion tent. The generation of gas by this method is very rapid, requir- 



FiG. 15. 



-The Owl fumigating macliine, as constructed during 

 tlie season of 1013-14. (Original.) 



ing only a part of a second for a moderate-sized charge. A considerable 

 amount of heat is produced by chemical action, so that after one or two 

 charges, the whole apparatus becomes uncomfortably warm to the hand. 

 The leaden bowl previously referred to in which the reaction takes place 

 is mounted on a pivot and provided with an outside lever. After the 

 generation of cjk h charge, the residue is emptied into the liottom of 



