OP WIRES FOR ELECTRICITY. 



317. 



in observation*, that it appears to me wortli while to apply this method, 

 and thus exhaust all the proofs of this important point in the theory of 

 the pile. I shall therefore propound them in the following series of 

 experiments, which, though they do not establish a new law, will yet 

 I hope secure for ever the old one against all further objections. 



The manner in which these experiments have been performed does 

 not at all differ from that described in the above-mentioned memoirs, 

 and I refer therefore to them for the description of the apparatus and 

 the manner of experimenting. I shall but expatiate upon one point, 

 which should have there been more fully investigated. Having fastened 

 the horse-shoe magnet in a vertical position, I suddenly detached from 

 it the cylindrical keeper with the surrounding electromotive spiral in 

 order to produce the current, and observed through a glass the sud- 

 denly produced deviation of the needle of the multiplier. From this 

 mode of proceeding a doubt may arise, whether the current thus pro- 

 duced was always of the same strength, or whether the suddenness of 

 the disruption, which cannot be always strictly equal, did not exercise 

 a real influence ; and Christie has indeed, for fear this might be the 

 case, performed the disruption by the fall of a determined weight from 

 a determined elevation. I convinced myself however at the very be- 

 ginning by experiments that the suddenness of the disruption, having 

 suqjassed a certain term, exercises no influence whatever on the strength 

 of the current. The results of the experiments Avere the following : 



By purposely breaking contact 

 very slowly 



By purposely breaking contact 

 very suddenly 



By breaking contact with ordinary 

 quickness 



Experiment. 



1st. 



100-7 

 100-7 

 101-0 



2nd. 



100-7 

 101-0 

 100-2 



Sid. 



Average. 



100-8 

 100-6 

 100-7 



100-73 

 100-77 

 100-63 



The averages show that the influence of the suddenness of di.sruption 

 may be considered as = 0, the differences of the deviations of the needle 

 not surpassing -iV of a degree. Besides the above experiments, per- 

 formed solely for this purpose, there are also numerous confirmations of 



my first paper on this subject was read before the Imperial Academy of Sciences 

 on November the 7th, 1832. (See Memoires, — Sciences Mathem. etPhys., vol ii 

 p. 427.) 



• See Memoires de I' Acad. Imp. de St.Pelersh. (Sciences Mathem. el Phys., 

 vol. ii.) 



