AN INQUIRY INTO THE NATURE OF ELECTRICAL 

 DISCHARGES IN AIR AND GASES. 



By Johx Trowbridge. 



, Presented March 9, 1898. 



In a previous communication * I have described with some detail the 

 installation of a storage battery of ten thousand cells, and I gave a pre- 

 liminary account of some of the effects produced by this battery. It 

 seemed desirable to utilize to the utmost its ability to produce high 

 electromotive force. Hitherto investigators have been limited to a com- 

 paratively narrow range of inquiry on this subject ; and this paper 

 therefore contains an account of an incursion into what may be termed 

 a new region, in which matter is subjected to an unusual electrical 

 stress. 



The discharge from a large number of Plante cells is characterized by 

 a sibillant flame, which, by quickly separating the spark terminals, can be 

 drawn out to a length of several feet. It closely resembles the light 

 produced by passing an electric spark through lycopodium powder. 

 When a photograph of this flaming discharge is examined, it is seen to 

 have an intensely bright spark as a nucleus. On account of the flaming 

 discharge it is difiicult to examine its character by means of a revolving 

 mirror. By employing, however, two spark gaps, it seemed possible to 

 ascertain whether the discharge is oscillatory or not. 



In my experiments the circuit was made at the instant the revolving 

 mirror was in the position to reflect an image of the discharge of the 

 battery upon a sensitive plate. The photographs obtained in this way 

 showed disruptive discharges superimposed upon a continuous discharge. 

 The latter, however, masked any appearance of an oscillatory discharge. 

 It was evidently necessary to blow out the flaming discharge in order to 

 see if oscillations followed the pilot discharge. The flrst experiment was 

 made with 2500 cells arranged in series ; and the flaming discharge was 

 much lessened both by the reduction in the number of cells and by a 

 suitable arrangement for blowing it out. On developing the photographs 



* These Proceedings, XXXII. 253. 



