On a new Arrangement of the Induction Coil, 

 Table {continued). 



443 



LV. On a new Arrangement of the Induction Coil. 

 By Jonathan N. Hearder, Plymouth^. 



1. TN my communication to the last Number of tlie Philoso- 

 A phical Magazine, I confined myself to the announcement 

 of a few of the novel results which I had obtained from investiga- 

 tions with my induction coil. I might have given many more, but 

 purposely refrained from doing so until I had had an opportunity 

 of repeating my experiments with a still more powerful machine, 

 as certain indications had led me to believe that many of the results 

 which have hitherto been announced as peculiar to the action of 

 the induction coil, have been disguised by the mode of construc- 

 tion of the instruments of M. RuhmkorfF; such, for example, as 

 the ignition of the negative terminal only, and the comparative 

 inertness of the terminal proceeding from the inner portion of 

 the coil. These and other effects appeared to me to indicate 

 that M. Ruhmkorff^s secondary coil could not be perfectly insu- 

 lated from the primary one, and that the true statical condition 

 of the two terminals could not consequently be accurately ascer- 

 tained and compared. 



2. It happened in the first arrangement of my machine, that 

 I was led to construct all its elements separate and independent 

 of each other, for the purpose of ascertaining how modifications 

 of any of them influenced the action of the rest. The secondary 

 coil in this case was perfectly insulated, and I was frequently 

 struck with unexpected results, especially in the improved arrange- 

 ment of my first machine alluded to in my last paper, since both 

 terminals would sometimes become heated, and the inner terminal 

 was possessed of such high statical intensity that it could not 

 be handled with impunity. In a still more powerful machine 



* Communicated by the Author. 

 2 62 



