SCIENTIFIC MEMOIRS. 



VOL. v.— PART XX. 



Article XIV. 



On the Measurement of Electro-dynamic Forces. 

 By W. Weber. 



[From Poggendorff's Annalen, vol. Ixxiii, p. 193, January 1848.] 



A QUARTER of a century has elapsed since Ampere laid the 

 foundation of electro-dynamics, a science which was to bring 

 the laws of magnetism and electro-magnetism into their true 

 connexion and refer them to a fundamental principle, as has 

 been effected with Kepler's laws by Newton's theory of gravita- 

 tion. But if we compare the further development which electro- 

 dynamics have received with that of Newton's theory of gravita- 

 tion, we find a great difference in the fertility of these two fun- 

 damental principles, Newton's theory of gravitation has become 

 the source of innumerable new researches in astronomy, by the 

 splendid results of which all doubt and obscurity regarding the 

 final principle of this science have been removed. Ampere's 

 electro-dynamics have not led to any such result ; it may rather 

 be considered, that all the advances which have since been 

 really made have been obtained independently of Ampere's 

 theory, — as for instance the discovery of induction and its laws 

 by Faraday. If the fundamental principle of electro-dynamics, 

 like the law of gravitation, be a true law of nature, we might 

 suppose that it would have proved serviceable as a guide to the 

 discovery and investigation of the different classes of natural phae- 

 nomena which are dependent upon or are connected with it; 

 but if this principle is not a law of nature, we should expect that, 

 considering its great interest and the manifold activity which 

 during the space of the last twenty-five years that peculiar branch 



VOL. v. I'ART XX. 2 L 



