224 The Spraying of Plants. 



the parts to be treated are more removed, being situated from 

 ten to twenty-five feet away, a coarser spray is wanted; the more 

 distant the object, the coarser the spray. The work can thus be 

 done much more rapidly, just as effectively (with the exception 

 of some waste), and much more satisfactorily, than by the use of 

 a fine spray. In case a fine spray is used, it is necessary to have 

 a pole to carry the nozzle to the different parts of the tree, and 

 this is as tedious as it is unpleasant. When a coarser spray is 

 made, there is generally formed enough of the finer spray to float 

 in the air and protect parts which are not directly reached by 

 the operator. 



The finest sprays are produced by the eddy-chamber nozzles, 

 and by those in which two streams of water strike each other 

 at an angle. With such nozzles, the spray can be made as fine 

 as desired, the size of the outlet orifice being the main control- 

 ling factor. For long-distance work, when the liquid is to be 

 carried ten feet or more, the best spray is formed when the fluid 

 is forced through two flat, parallel, metal surfaces. The greater 

 the pressure, the greater will be the amount of fine spray and 

 the farther will it be thrown. Although the ideal nozzle has 

 not yet been made in metal, some of the forms now sold are 

 approaching perfection. 



All good spray machinery is expensive, and only careless 

 operators will neglect the ordinary methods of preserving it 

 as long as possible. When the pump has been used in applying 

 any of the preparations mentioned in Chapter IV., with the ex- 

 ception of clear water, it should be cleaned. No insecticide nor 

 fungicide should be allowed to stand within the pump, but clear 

 water should be pumped through it before it is put away. It 

 is well to oil all the working parts occasionally, as a little oil at 

 times may prevent the metal from being cut, and the pump w r ill 

 be thus preserved much longer than otherwise. Nozzles are also 

 benefited by the same treatment. Oil can scarcely be used too 

 freely on the inside of such apparatus, and an occasional coat of 

 paint on the outside will assist materially in protecting the 

 metal. The careless man pays dearly for his neglect. 



