THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



JANUARY 1855. 



I. On a Method of increasing certain Effects of Induced Elec- 

 tricity. By W. R. Grove, Esq.* 



TN the course of last year I observed that, by connecting the 

 J- coatings of a Leyden phial with the extremities of the secon- 

 dary coil of RuhmkorfFs apparatus, a great increase in the bril- 

 liancy of the discharge could be obtained. Circumstances diverted 

 my attention from it at the time, and I did not publish the expe- 

 riment, though I believe Mr. Gassiot mentioned it in one of his 

 papers. I have since heard that M. Sinsteden in France had 

 made the same observation, though I do not know when, nor 

 whether he has published his experiments. 



The point which I now think may be worth insertion in the 

 Philosophical Magazine, is the conversion, by means of a Ruhm- 

 korff coil, of an indefinite amount of voltaic power into static 

 electricity. If a small Leyden phial have its coatings connected 

 respectively with the extremities of the secondary wire of a 

 Ruhmkorff coil (the primary being, as usual, connected with 

 the condenser of M. Fizeau, and two wires being attached to the 

 terminals and brought within striking distance), the noise and 

 brilliancy of the discharges are greatly increased, with generally a 

 slight, but a very slight, diminution in their length. If now 

 the voltaic battery be increased, the coil and Leyden phial re- 

 maining the same, but little increase in the length or brilliancy 

 of the sparks will ensue, that is, provided the battery was in the 

 first instance sufficiently powerful to give the maximum effect of 

 the coil without the phial. For instance, if with a Ruhmkorff 

 coil of the size now usually made, 10 inches long by 4 diameter, 



* Communicated by the Author. 

 Phil. Mag. S. 4. Vol. 9. No. 56. Jan. 1855. B 



