396 



DE. G. C. SIMPSON ON THE ELECTEICITY OF 



upon the jet of air escaping from the nozzle, where it was split up into numerous 

 small drops through the sudden stoppage of its downward motion. When this 

 adjustment was well made the drops broke up in a symmetrical crown about 4 cm. 

 above the nozzle, and the greater part of the small drops so produced fell directly 

 into the tray. In order to prevent small spray from being blown over the sides of 

 the tray, a roof in the form of a hollow truncated pyramid, having a hole 5 cm. 

 square at the top, was fitted over it. The drops fell through the hole in the roof 

 and were broken up on the air jet, but only a very little of the spray escaped with 

 the stream of air. 



i jj"'l"'j t '"''"iii'" l '"iL'"'""i!i'"'"'ii! ijj ijimli..^.!.!...;!. 



FIG. 2. 



A fine wire-gauze cage was placed over the tray to protect it from extraneous 

 electrical fields, and a Dolezalek electrometer was used for measuring the potential of 

 the tray. 



The method of making an experiment was as follows. The funnel was filled with 

 distilled water and a cock opened to let the water flow in large drops from the 

 orifice within the metal cylinder. The bellows were then worked until the 

 manometer showed a pressure of about J metre of water and the position of the 

 funnel above the nozzle was adjusted until the drops were symmetrically broken up 



