40 



SPRAYING CROPS 



a violent or quick motion is necessary for thorough 

 agitation, while for pumping, a regular, steady stroke 

 is the best. Therefore it is best not to attem.pt to 

 couple the two motions. 



'Taris green, when used alone, is, perhaps, the 

 only material which requires continual agitation; and 

 that, in the opinion of the writer, is a serious objec- 

 tion to its use, now that lighter-grained poisons have 

 been found which settle much more slowly and conse- 

 quently do not need continuous agitation. If we 



An Agitating Device 



omit Paris green from consideration, the liquids now 

 in general use can be sufficiently stirred at short inter- 

 vals — best w^hile the rig is moving from one tree to 

 another. A separate agitating device is therefore 

 preferable. The operator can do more with the few 

 vigorous turns he is then able to give the agitator 

 than is possible when the motion is dependent upon 

 the pump handle. On large, flat tanks it is prac- 

 tically impossible to keep up a sufficient pressure and 



