140 Control of Parasites 



ous forms which such apparatus might take. A full dis- 

 cussion may be found in the Yearbook of the United States 

 Department of Agricukure for 1896, and in other publica- 

 tions, notably of the State Entomologists, various combina- 

 tions are proposed.^ 



Since the spray mixtures are very corrosive, the apparatus 

 should be thoroughly cleaned immediately after use by 

 forcing pure water through it and 

 wiping off the exposed parts. 



Failures in results from spraying 

 come either from unsatisfactory ap- 

 paratus, such as lack of an agitator 

 on the pump, poor nozzles throwing 

 a shower, instead of a mist, insufR- 

 FiG. 54. — "Gem" nozzle dent and variable pressure, or else 

 unsatisfactory application, lack of 

 thoroughness, failure to choose the right time or weather 

 (wind and rain) , and use of wrong materials, or improperly 

 mixed ones. 



As to the cost of spraying, the Entomologist of the Depart- 

 ment of Agriculture estimates that, after a proper apparatus 

 is installed, for a city like Brooklyn, N. Y,, an expenditure 

 of $4,000 to $5,000 would result in green shade trees all 

 through the summer, and this expenditure would probably 

 not need to be continued annually. The cost must neces- 

 sarily vary according to the number and size of trees to be 

 treated and to other circumstances, reported experiences 



' Reliable dealers in spraying machinery are: Gould Manufacturing Co., 

 Seneca Falls, N. Y.; Field Force Pump Co., Elmira, N. Y.; Sydnor Pump 

 and Well Co., Richmond, Va.; Morrell & Morley, Benton Harbor, Mich.; 

 Darning Co., Salem, Ohio; E. C. Brown Co., Rochester, N. Y.; Spraymotor 

 Co., Buffalo, N. Y., and London, Canada; Rochester Spray Pump Co., 

 Rochester, N. Y.; Friend Mfg. Co., Gasport, N. Y.; Hardie Spray Pump 

 Mfg. Co., Detroit, Mich.; \Vm. Stahl, Quincy, 111. 



