PNEUMATIC COMPRESSION SQUIRTERS. 2o7 



Several years ago while teaching; (jhemistry I made a gas gcDerator 

 on this phiu,- and it gave perfect satisfaction. Where other gases are 

 used, such as are generated by heat, such a metal generator is very 

 essential. The generator chamber needs to be cleared out or charged 

 occasionally, and this is not easily accomplished, unless its end opens 

 entirely by a removable plug or cap. The metal chamber can be 

 roughly jarred or gouged out with no resultant breakage. The acid 

 chamber ought preferably to have its neck or mouth i)rovided with a 

 metallic lead cock or other secure non-corrosible shut-off device. 



ROTARY FORCE-BLAST, COMPRESSION EJECTORS. 



The rotary force blast blowers have not yet been utilized in insecti- 

 cide machines. 



OSCILLATING BELLOWS, PNEUMATIC COMPRESSION EJECTORS. 



[Plate XXXV.] 



The bellows recommended for blowing powder and atomizing liquids 

 can also be used for producing air-pressure in a tight reservoir to eject 

 the liquid contained ; and in this way may serve as a substitute for a 

 force-pump or gas generator. The bellows should be small and very 

 strong, that an unusual amount of i)ower may be applied to do this 

 work. lu order to avoid resuction of the blast back into the bellows 

 and to be able to produce a constant condensation in the reservoir an 

 ^xcurrent valve from the bellows must be interposed between it and the 

 reservoir. By such means parties having a bellows for atomizing can 

 also apply it as a machine to squirt liquid for poisoning or irrigating, 

 &c., and its notice here may in some cases prevent the purchase of a 

 force-pump when not necessary. Also experiment with such devices 

 may show that they are preferable to pumps in some squirting machines. 

 Since many prefer the application of dry powder in rainy weather, and 

 of wet poison in dry weather, such parties can make a bellows answer 

 for both methods. The bellows may be worked beneath the foot, and 

 the weight of the operator's body can thus be used, which will be found 

 more pleasant than the exertion of arm -power. Machines for squirting 

 by bellows-pressure are now articles of trade, and in use chiefly for 

 forcing beer, &c., from barrels. So far this use of the ordinary bellows 

 only promises to be practical where small pressure will answer. 



The simple process is indicated in Plate XXXV, Fig. 5. The bellows, 

 v, operated by the lever, by foot, by hand, or machinery, discharges 

 through its excurrent valve and the pipe, Zc, into the top of the barrel, r, 

 whereby the air compressed in r forces the liquid, jp, downward, causing 

 its ejection through the outlet tubes, n or m-m. jS'ozzles, ss, ma^' be 

 connected to the outlet tubes in any suitable number or by any system 

 of couplings or pipes. There are other ways of combining the bellows 

 with the reservoir, but only one simple illustration can be given here. 

 63 CONG 17 



