PEAR GROWING IN CALIFORNIA. 



339 



Fig. 



141. Spraying cherry trees at a distance of one-half mile from pump, illustrating 

 the high pressure attained in the Gammon underground spraying system. 



GAMMON SYSTEM. 



Fig. 1-13 is an accurate map of the underground spraying system in 

 E. A. Gammon's orchard, as it was originally planned. A slight 

 modification of this system was finally adopted and will be explained 

 later. The heavy lines in map indicate the pipe lines extending 

 throughout the 100-acre orchard, and the light lines represent tree rows. 

 The pumping plant is located in the extreme southwestern corner of the 

 picture. A "Bean Giant" four-cylinder pump, Fig. 142 is used to 

 force the spray throughout the system, the power for running the 

 machinery being derived from an electric motor. Water is raised from 

 the river with a 1^-ineh centrifugal pump through the pipe D into the 

 tank A. The dilute insecticide or fungicide flows by gravity through 

 pipe E into delivery tank B, which is equipped with a powerful agitator 

 that keeps the spray well mixed. From tank B the liquid is pumped 

 into the system at a pressure of 350 pounds at the pump. This pressure 

 is sufficient to give a strong spraying pressure at nozzles at the points 

 farthast away from the pumping plant, as illustrated in Fig. l-ll. which 

 shows cherry trees being sprayed at a distance of approximately one- 

 half mile from the pump. As the specifications do not show clearly in 

 the cut they are printecl underneath. From these it will be seen that 

 the pipe running from the pump to point B is 1^ inches in diameter. 

 From this point it is reduced to 1^ inch, later from 1^ to 1 inch, and 

 f inch at extremities, all service cocks being f inch. 



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