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AN ECONOMIC ENTOMOLOGY. 



adapted to his special use will occur to any intelligent farmer. 

 Applied through a sack, the dusting is exceedingly fine, while it is 

 at the same time thorough, at least so far as the upper side of the 

 leaves is concerned. 



It is in spraying machinery that the greatest advance has been 

 made, and for a good spraying outfit there are two essentials, — a 

 pump and a nozzle. The tank containing the spraying mixture 

 may be almost anything, — a barrel, a tub, a box wagon, an elab- 

 orate tank cart, or even a pail. What his receptacle shall be, 

 each farmer may decide for himself The pump may also be of 

 any type or pattern, provided that at least the working parts are 

 of brass, because otherwise the corrosive poisons are apt to destroy 

 it. For orchard work, or where large trees are to be sprayed, 

 the pump should give a pressure of one hundred pounds or more, 

 without requiring too much exertion. It should be double-acting 

 to give a continuous stream, and should have an air-chamber of 

 good size. The piston, or plunger, should not have too great a 

 diameter, because the greater the diameter the greater the amount 

 of force required to obtain a desired pressure. It must be re- 

 membered that in ordinary spraying operations the object is not 

 to throw the greatest possible amount of water in the least pos- 

 sible time, but to obtain the greatest amount of pressure with the 

 least expenditure of force. Force is to be looked for rather than 

 quantity of discharge. There are many pumps upon the market 

 fulfilling all the conditions above enumerated, and at various 

 prices. 



Having selected the pump and mounted it upon any sort of 

 tank, the next question is as to the nozzle to be used. What we 

 want is the finest possible spray and the greatest possible amount 

 of force, and these two requirements are more or less antagonistic. 

 A very fine spray cannot be sent a great distance, and a jet 

 capable of being sent into the top of a high tree is a wasteful 

 method of application. There are, therefore, several types of 

 nozzles adapted for somewhat different classes of work. By all 

 odds the best, and the one having the greatest range of useful- 

 ness, is the Vermorel modification of the "cyclone" or eddy- 

 chamber nozzle. This consists, essentially, of a circular chamber 

 into which the water enters from one side under pressure, receiv- 

 ing thus a rotary motion. The point of exit is a single hole in 



