SPRAYING MACHINERY I29 



or a gasoline engine. A special air pump is installed 

 and connected with the horse power or gasoline en- 

 gine, and this pump forces the air into the air cylinder 

 of the spray machine up to any reasonable pressure. 

 About 200 pounds is the practical limit. The air cyl- 

 inder is connected with the liquid cylinder by means of 

 suitable cocks. By opening these the liquid is blown 

 out and through the nozzles onto the trees. The pres- 

 sure goes down slowly during the process of discharg- 

 ing the liquid ; but when properly managed does not 

 fall so low as seriously to impair the results. 



Perhaps the chief difficulty in the way of the popu- 

 larity of the compressed air sprayers is the cost of in- 

 stalling the original power plant. This is said to be 

 about $250, though it varies, of course, with circum- 

 stances. On farms where a reliable source of power, 

 as a gasoline engine, is already established, the 

 cost is much less; and under such circumstances 

 the claims of the compressed air machines should 

 be carefully considered before buying any new 

 outfits. The power is very cheap, once the ma- 

 chinery is installed, and the outfit is light and 

 easily hauled through the orchard. 



Gas Pozver for Spraying — There has recently been 

 introduced and widely sold a novel machine for spray- 

 ing purposes, which derives its power from purely 

 chemical sources, A small tank or cylinder is charged 

 with carbon dioxide gas. This is the same gas used in 

 soda fountains, and it is used in spraying in almost the 

 same way. A strong air-tight metal tank holding 50, 100 

 or 200 gallons of spray mixture is mounted on a suitable 

 wagon or truck. The cylinder of gas, about 8 inches 

 in diameter by 4 feet long, is fastened on beside this 

 tank. The gas pressure is opened into the lank of 



