PRINCIPLES OF SPRJYING 



power, particularly when It can be used for 

 several purposes. 



The compressed air gas sprayer comes next 

 In point of simplicity and cost for a power 

 sprayer. Its most economic use is found where 

 orcharding is carried on extensively enough to 

 pay to compress the air or gas right in the 

 orchard. This is of course impracticable on 

 the general farm. Therefore the air or gas 

 must be purchased and shipped to the farm in 

 steel tubes. This often causes delay at critical 

 times and is rather expensive. Moreover, the 

 gas is open to the objection of Interfering with 

 the lime-sulphur compound by precipitating 

 some of the sulphur. 



The gasoline engine is the most useful and 

 popular type of power for the orchard sprayer, 

 as well as for general use on the farm. Many 

 makes are now so perfected that they give little 

 or no trouble. One and a half or two horse- 

 power are fully sufficient for spraying, but most 

 farmers prefer from three to five horsepower 

 In order to be able to use the engine more for 

 other purposes. The latter power is open to ob- 

 jection for spraying purposes on account of Its 

 weight, as especially in early spring it is very 

 difficult to haul so heavy a rig over the soft 



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