182 



SPRAYING APPARATUS 



in a large chamber. This compressed air, in turn, forces the 

 liquid out of the tank. The great objection to this machine is 

 that the pressure runs down as soon as the wagon stops. And 

 since it is absolutely necessary to stop in order to do good 

 spraying on trees of any size the best orchardists have ruled 

 this machine out of their list. It is all right with small trees 

 where the outfit travels a considerable distance for every gallon 

 of liquid put out, but most orchardists cannot afford so expensive 

 an outfit for this one type of spraying. This type is fairly rapidly 

 going out of use. 



The second 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. S2. — A gasolene power outfit. The most efficient power sprayer. The cut also shows 

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



The air is compressed by a special apparatus which 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 



