INSECTICIDES, PREVENTIVES, AND MACHINERY. 465 



from the plant, and run horizontally downward to a point a little 

 below the roots. To accomplish this the injector must be inserted 

 at an angle, as shown in the figure. Force it down until the 

 point is a little below the roots, then let out the charge of liquid. 

 In operating the injector, first pull the piston up as far as it will go. 

 This loads the measuring chamber between the valves. Then 

 push down the piston until it stops, and the instrument is ready 

 to be pushed into the ground. Push it into the ground as far as 

 desired. Hold it there while you pull up the piston. By this 

 operation you let the charge out of the lower chamber into the 

 ground, and at the same time the measuring chamber is again 

 filled. Hold the injector in the ground a few seconds after the 

 piston has been pulled up, in order that all the liquid in the 

 charge may have a chance to run out. Then pull the injector 

 out of the ground, and quickly, with the foot, fill the hole with 

 earth and step on it to pack it down. Press down the piston, 

 and you are ready to treat the next plant. Never push the 

 injector into the ground unless the piston is clear down, because, 

 if the lower end is not thus closed, it will immediately fill with 

 soil, which is not easily removed. Study the drawings in Fig. 

 480, in connection with these directions, and you will under- 

 stand the reason for each step. We would advise that the reser- 

 voir be first filled with water and the injector operated above the 

 ground until each step is thoroughly understood. There is 

 nothing complicated about the instrument or the way it is to be 

 operated. It can be easily taken apart and cleaned, if necessary ; 

 the only caution to be observed in replacing the parts is to have 

 the flanges of the leather in the upper valve turned upward. 

 The injector is made by John J. McGowen, Ithaca, New York. 



Under this head we may refer to the ''hopper-dozers" which 

 have been recommended against certain Hemiptej'a and Orthop- 

 tera. These are simply shallow pans of thin sheet-iron, of con- 

 venient length for the special use intended, mounted on runners 

 so high as to bring the bottom of the pan to the top of the vege- 

 tation to be treated. The runners can easily be made adjustable in 

 height by any clever mechanic. The front of the pan is turned 

 up enough to prevent its cutting or otherwise injuring vegetation, 

 and the sides are also turned up at least two inches and the cor- 

 ners made sufficiently close to hold water, if necessary. Along 



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