72 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



of the liquid out of the other tank at a pressure never below 100 

 pounds, and averaging 125 to 150 pounds. The advantages of 

 these outfits are that they are much lighter, so that more liquid 

 can be carried, and that the men on the outfit need have no 

 mechanical ability, as is necessary with the operation ofa gasoline 

 engine pump. The trucks and tanks are much cheaper than the 

 gasoline sprayers, but the cost of the engine and air-compressor 

 at the charging station makes the total cost probably more. It 

 is also necessary for each tank to return to the charging station, 

 and it is not possible to use a supply tank, as is commonly done 

 with gasoline sprayers. However, these outfits are in successful 

 operation by some of the largest orchardists, who believe them to 



FIG. 43. Vermorel, bordeaux, and disk type of nozzles. 



be much the best type of sprayers for large operations, so that they 

 merit study by those contemplating extensive spraying. 



Nozzles. A good nozzle is as essential as a good pump for suc- 

 cessful spraying. The best nozzles now in common use are of 

 three types. 



The Vermorel type consists of a small chamber into which the 

 liquid is admitted at a tangent and leaves through a small hole in a 

 removable cap, thus making a fine, cone-shaped spray. A small 

 pin, with a spring to hold it back when not in use, serves as a dis- 

 gorger to remove any sediment which may clog the outlet. This 

 type of nozzle is made in many slightly different styles and often 

 sold under trade names, such as the Demorel, Mistry and others. 

 A slightly modified form has no spring attached to the disgorger, 

 but has a loose cap which is held away from the pin by the force of 



