Decembee 27, 1895.] 



SCIENCE. 



869 



Force,' ' On the Physical Lines of Magnetic 

 Force,' ' Thoughts on Eaj' Vibrations,' etc., 

 are just like the glow of an approaching 

 sunrise. The fairyland of Faraday's vision 

 begins to appear clearer and clearer in this 

 gently rising light ; but, alas ! the cloud of 

 old age hides away the beauties of the 

 sunrise itself. 



It was reserved for Maxwell to raise the 

 lofty edifice from which we first obtained a 

 clearer view of the wonderland of Faraday's 

 vision. 



I cannot do better than sum up this brief 

 statement of the position which, in my 

 opinion, Faraday occupies in the tenden- 

 cies of modern electrical research, by quo- 

 ting the following words of Hertz, * the 

 most brilliant of all the pupils of Helm- 

 holtz, Maxwell and Faraday : " Faraday 

 heard of the belief that electrification puts 

 something into a body, but he saw that the 

 changes produced were all external and 

 none internal. Faraday was taught that 

 forces jump through space, but he saw that 

 these forces wei-e influenced in the highest 

 degree by the substances which filled the 

 space. Faraday read that electricities cer- 

 tainly existed, but that their forces were a 

 disputed question, and yet he saw that 

 these forces produced tangible effects, al- 

 though he could not perceive anything of 

 the electrifications themselves. Hence, in 

 his conception, the state of these things be- 

 came reversed. The electric and the mag- 

 netic forces appeared to him as existing, as 

 real, as tangible ; electricity and magnetism 

 were things whose existence might be a dis- 

 puted question. The lines of force, as he 

 called the forces considered as independent 

 entities, stood before his mind's eye as con- 

 ditions in and of the space, as stresses, as 

 vortices, as fluxes, as something or another 



* Vortrag, gehalten bei der 62. Versammlung 

 dentsoher Naturforsoher uud Aerzte za Heidelberg 

 am 20, September, 1889. Publ. by E. Strauss in 

 Bonn. 



— he could not tell as what — but there they 

 stood, influenced each other, they pushed 

 the bodies and they pulled them, and they 

 continued from point to point, conveying 

 impulses to each other. The objection that 

 nothing but absolute rest was possible in 

 empty space he met with questions : Is 

 space really empty ? Does not light itself 

 compel lis to assume it as filled? Could 

 not ether which conveys the waves of light 

 become the seat of those changes which we 

 recognize as electric and magnetic forces? 

 Is it not even possible to imagine a relation 

 between these changes and those waves of 

 light? Why could not these waves of light 

 be something like the oscillations of those 

 lines offeree? " 



" So far did Faraday reach in his concep- 

 tions and his surmises. He could not prove 

 them. He busily searched for evidences. 

 The connection between light, electricity 

 and magnetism was the favorite subject of 

 his research. The beautiful connection 

 which he found was not the one for which 

 he looked. Only the highest old age put 

 an end to his efforts." 



maxwell's INTERPEETATION -of FARADAY. 



Faraday did not form a new school of 

 physi.cists during his lifetime. His ideas 

 were too original, his view of the electro- 

 magnetic phenomena was too different from 

 the generally accepted view of his time, to 

 gain him a large following even among his 

 own countrymen. His generation recog- 

 nized the value of his discoveries; it failed 

 to appreciate the full meaning of the aims 

 of his speculation. It was reserved for the 

 next generation to grasp this meaning and 

 to explain it in terms of the language of the 

 existing theories. It was by no means an 

 easy task for the next generation to per- 

 form. It required a peculiarljr constituted 

 mind, a mind combining in itself the qual- 

 ities of a phj'sical investigator and those of 

 a mathematician. Maxwell was a true 



