26 



the gas supply is not too distant, this class is very practicable. 



With the second class the pressure is furnished by cylinders 

 of compressed air, the air eompressing plaát being situated 

 near the orchard of field. r riiis forra is not so popular as it 

 once was. 



The third class of power sprayer consists of a pump geared 

 to the wheels of the vehicle upon which it is mounted and the 

 pressure is supplied as the vehicle is clrawn along. The accom- 

 panying figure illustrates a, typical machine of this form. (Fig. 

 7). In general usage this class of spráyers is very efficient in 



3 

 Oí) 



