182 SPRAYING APPARATUS 



small and light and it requires no extra man to run it. The 

 two difficulties which orchardists have with it are that the 

 cost of power is relatively high and that such materials as 

 Bordeaux mixture and lime-sulfur tend to coat the inside of 

 the tank and then peel off in flakes which constantly clog the 

 nozzles. As the tank is required to stand a heavy pressure there 

 is only a small opening into it and it is well-nigh impossible to 

 keep it thoroughly cleaned out. 



The third type* of power sprayer uses compressed air as a 

 source of power. It is, therefore, essentially like the type just 

 discussed, except that it uses air instead of carbonic acid gas. 



Fig. 82. — A gasolene power outfit. The most efiScient power sprayer. The cut alao shows 

 an excellent arrangement for filling the tank and mixing the materials. 



The air is compressed by a special apparatus w'hich has to be 

 installed on the farm, and this makes the first cost high. There 

 is also the same objection in reference to scaly coating from the 

 inside of the tank clogging the nozzles. 



The last and by all means the most important type of power 

 sprayer at the present time is that run by a gasolene engine 

 (Fig. 82). The best of these engines have been perfected until 

 they give relatively little trouble in running and the pumps are 

 also admirably adapted to the work. Of course the great ad- 

 vantage of any power sprayer over other types of pumps is the 

 high and relatively constant pressure that it develops. With 



