INSECTICIDES, PREVENTIVES, AND MACHINERY. 463 



tions in the act of spraying. At the present writing this machine 

 is not sufficiently perfected to warrant me in recommending it, 

 but no doubt practical machines will be constructed, in the near 

 future, carrying kerosene in one tank and water in another, with 

 a pump so arranged that the materials will combine in a mechani- 

 cal mixture that can be satisfactorily applied to plants. 



Fig. 479- 



An " emulsion" knapsack sprayer for combining kerosene and water. 



For applying insecticides underground, which is sometimes 

 desirable in using bisulphide of carbon against the cabbage-root- 

 maggot and other subterranean species, there is only one satis- 

 factory piece of machinery, — the McGowen injector. This is best 

 explained by Fig. 481, illustrating its use on cabbages. The fol- 

 lowing directions may be observed, and will at the same time 

 indicate the method in which the machine may be used for other 

 purposes. 



The method of inserting the injector is shown in Fig. 481. 

 The hole should always begin at a distance of three or four inches 



