Insect Exterminators. 115 



If eight houses are to be vaporized at once, instead of 

 four, the process is the same except that double the 

 amount of extract must be supplied to the cylinder. 



With the price of extract at $1.50 per gallon, the cost 

 of material will be about 10 cents per house. 



To avoid condensation and make quick work, about 

 fifty pounds steam pressure should be indicated and 

 maintained until through, ar.d whatever is used for a 

 cylinder it should be strong enough to stand that 

 amount of pressure. I am using, at present, a common 

 range boiler, three and one-half feet in length by one in 

 diameter, but before being set up it should be tested by 

 means of either steam or hydraulic pressure. 



The thing to be most guarded against, is the conden- 

 sation of the steam and consequent weakening of the 

 extract, as well as the condensation of the vapor itself 

 while being applied. If the latter occurs, the extract 

 will drip from the end of the distributing pipe, while 

 it should all be sent) into the house mingled with the 

 steam. No water should ever be allowed to enter the 

 cylinder with the extract, and when through, valve E 

 should be opened and any sediment remaining washed 

 out, otherwise stoppage, may occur in either the feeds to 

 the glass or the pet cock H. 



Another thing to be avoided is entrance to a house 

 Avhile the process is going on, or for a short time after 

 Ihe vapor has been applied, as the nicotiiie sometimes 

 affects either the eyes or stomach unpleasant!}-. The 



