SELECTING MACHINERY AND EQUIPMENT 333 



tightened without cutting into the fabric. Aluminum and iron 

 clamps may be used. Wire clamps are difficult to keep tight 

 and are likely to cut the hose. 



The Traction Sprayer, The traction sprayer derives its 

 power from the turning of the wheels on which the machine is 

 hauled over the ground. Gears of h proper type transmit this 

 power to' the pump, through which the spray material passes. 

 The pump may possess one, two, or three cylinders (Fig. 125) . 



It is evident that, when the wheels stop turning, the gen- 



[New Jersey College of Agr.) 



Fig. 124. The grower has installed an automo- 

 bile engine of four cylinders in this outfit with a 

 four-cylinder pump to make a very effective 

 spray unit. 



eration of power ceases and the pressure soon runs down. 

 Since in orchard spraying the machine cannot be constantly 

 in motion, the traction sprayer is not well adapted to the 

 spraying of trees. It finds its greatest usefulness for the fruit 

 grower in the spraying of grapes, berries, and other small 

 fruits, where the machine may continue in motion. The ma- 

 chine must work rapidly enough to maintain the pressure 

 and slowly enough to permit thorough coverage. A pressure 

 chamber helps in this connection 



