92 'MISCELLANEOUS FARM SUBJECTS 



Herein lies the strength of the horse as an economic animal. 

 He has been assailed by the bicycle, the electric street and suburban 

 car, and by the automobile, but all combined have not prevented 

 horses from increasing in numbers and in value. As a source of 

 farm power and as a substitute for human labor in combination 

 with machines, the horse's economic place on the farm is more 

 strongly established than ever before. 



Spraying. Machines for spraying are coming into general 

 use for the destruction of insects and weeds, and many different 

 machines are on the market. Without spraying machines com- 

 mercial orcharding would practically be a failure. 



The adoption of steam-power spraying has been a necessary 

 and expected outgrowth of the remarkable extension in the use of 

 hand spraying machines. At the time when the investigation of the 

 cotton caterpillar of the South was begun, just before 1880, practi- 

 cally no spraying machines were on the market. There were one or 

 two bucket pumps, which, however, were not especially designed for 

 work against insects, and one or two cumbrous knapsack apparatuses 

 for use against the Colorado potato beetle had been devised. The 

 investigation of the cotton caterpillar resulted in the invention of a 

 number of machines for field distribution of liquid poisons, and 

 above all in the production of the "Eddy-chamber," or cyclone, sys- 

 tem of nozzles, which has since become so prominent in insecticide 

 and fungicide work. The discovery at a somewhat later date of the 

 value of liquid applications as fungicides with vineyard work brought 

 about the invention and manufacture of a serviceable series of knap- 

 sack pumps, and the almost simultaneous discovery of the applica- 

 bility of liquid poisons as a remedy against the codling moth and 

 plum curculio in apple and peach orchards started the construction 

 of hand spraying apparatuses on a larger scale and mounted upon 

 wheels for orchard work. A still later outgrowth in this line of work 

 is the adoption, although as yet to a slight extent, of horse-power at- 

 tachments, bringing about a spray through the slow progress of the 

 horse through the orchard. 



Among the first power spraying machines to prove successful 

 was one invented in California. Trie pump for delivering spray 

 material is of horizontal, double-cylinder, plunger type, capable of 

 working against a pressure of 250 pounds to the square inch, and 

 is operated by a 1-horse power gas engine. A large tank of 100 

 gallons capacity contains spray fluid, a small square tank contains 

 gasoline sufficient to run the engine one or two days, and the other 

 tank contains water, which is circulated by a small pump around 

 the cylinder of the engine, thence through a coil inside of the main 

 tank, where it is cooled, then back into its own tank. 



In the rear of the pump is an air chamber and a pressure gauge, 

 and at the extreme end of the platform are connections with stop- 

 cocks for four or more lines of hose. Forward from the air chamber 

 runs an overflow pipe into the supply tank, having in it an adjustable 

 relief valve, which maintains a normal pressure when some of the 

 spray nozzles are shut Pff The overflow is delivered through two 



