INSECT PESTS OF OHIO SHADE AND FOREST TREES 189 



fore, more nozzles should be used on a single line and a lively work- 

 man should direct the nozzle. It is also advisable to have at least 

 one and sometimes two men to serve as hose bearers, especially if 

 extra lengths of hose are being employed'. One man should be with 

 the sprayer constantly to keep the machinery in good order and to 

 drive the team. Another man, well versed in the work of spraying 

 and the reasons therefor should accompany the rig to answer in- 

 quiries, guard pedestrians or vehicles from passing beneath dripping 

 trees or through the drift of the spray. Without such a man along 

 to explain the work, the entire outfit is being stopped constantly 

 by persons who wish to know why the work is being done, if it is 

 going to cost them anything, and the like. If the sprayer is not 

 arranged for carrying the unmixed sprays, extra hose, etc., a light 

 attendant wagon should accompany the rig to have the stock supply 

 of spraying materials readily available. Of course, arrangements 

 should be made for taking the water for mixing the sprays from the 

 city mains. The fire plugs are most convenient for this purpose. 

 In operating city sprayers, it has frequently come to the atten- 

 tion of the writer that one of the misplaced economies in the work 

 is too rigidly docking the workmen for "layoffs" on account of bad 

 weather. Since spraying cannot be done after a rain while the 

 trees are still wet, or during rainy weather, considerable time is 

 lost while other workmen are losing but little; hence it is difficult 

 to keep the gangs satisfied. To remedy this evil, leniency in dock- 

 ing should be exercised by timekeepers and foremen for time so lost. 



THE SOLID-STEEAM SPRAYERS 



Description. The solid-stream sprayers, as the name implies, 

 are so constructed and equipped that they deliver the spray in a 

 solid or unbroken stream until it reaches its maximum height, when 

 it suddenly explodes or separates into a fine mist. This result is 

 obtained by forcing the spraying liquid at tremendous pressure 

 through an exceedingly smooth-bore nozzle having an aperture 

 varying in diameter from one-eighth to five-sixteenth of an inch. 

 The height attained by the stream before exploding varies in accord- 

 ance with the size of the nozzle aperture and with the pressure em- 

 ployed. With the pressure remaining constant, the larger the aper- 

 ture the higher the spray may be thrown. By using the five- 

 sixteenth inch aperture with a pressure of 225 pounds at the nozzle, 

 it is possible to throw the spraying material 90 to 100 feet in the air 

 and with this equipment and pressure to deliver approximately 25 to 

 35 gallons per minute. The operator is able to remain on the ground 

 and reach the tops of most trees ; and this fact, together with the 



