Nolan and Enkight — Electrification Produced hy Breaking up Water. 5 



discontinuity occurs being lower, the purer the sample of water. The pressure 

 values are 16, 19, and 21 cms. Hg. 



Measurement of Drops. 



The next step is the measurement of the degree of pulverization produced in 

 the water at different pressures of the sprayer. The method finally adopted has 

 been indicated already ; but before dealing with it in detail a few results of a 

 general character may be mentioned. Observations made by different methods 

 showed that the drops falling on any part of the receiving vessel varied consider- 

 ably in size. The average size, however, did not vary much from place to place. 



2 4x10'' 



30>^10 ' 



53/^10' 



URE 



Fig. 2. 



About the middle regions of the vessel, where the bulk of the spray fell, the 

 average size was fairly constant. Out from this in each direction, that is back 

 towards the sprayer and out towards the edges of the plume of spray, the drops 

 tended to be smaller, but the difference was not very great. Electrical tests 

 showed a corresponding slight variation in the magnitude of the charge per c.c. 

 This was examined by putting a small vessel, suitably protected, insulated, and 

 connected to the electrometer, at various positions on the surface of the receiving- 

 vessel. A difficulty arises here as to the charges due to the frictional effects at 

 the nozzle. When capturing only a fraction of the water, it is no longer possible 

 to secure automatic compensation by connecting the sprayer and the receiving 

 vessel together. It is possible, however, to work at such an air-pressure that 

 purely nozzle effects are inappreciable. Tests made in this way showed that the 



