0BCEMBEK 27, 1895.] 



SCIENCE. 



867 



Tip by the Undulatoi-y Theory of Light and 

 the Principle of Conservation of Energy, 

 with both of which his mind was thor- 

 oughly imbued. Electric and magnetic at- 

 tractions and repulsions between material 

 bodies, induced electrifications and mag- 

 netizations and the manner in which these 

 actions between material bodies were modi- 

 fied by a change of the medium separating 

 them — all these phenomena could not fail 

 to reveal to a bold investigator of Nature's 

 hidden laws, like Faraday, that the law of 

 inverse square is by no means the final 

 goal of inquiry concerning electric and 

 magnetic forces. The many failures to 

 pass beyond that goal in the case of 

 gravitational force did not discourage him. 

 It is far beyond the limits of this brief 

 discussion to give an adequate review of 

 Faraday's epoch making discoveries by 

 means of which the Electrical Science was 

 liberated from its hopeless prison of direct 

 action at a distance theories and started on 

 its new and eventful career. SufiBce it to 

 mention briefly the main features only of 

 these discoveries, in order to bring out as 

 forcibly as I can their bearing upon the 

 tendencies of modern electrical research.* 

 Faraday's discoveries are generally known 

 to-day through the technical applications 

 of the fundamental principles which were 

 first established by these discoveries. The 

 dynamo and the motor, the telegraph and 

 the telephone, the induction coil and the 

 modern transformer, all these great inven- 

 tions, in fact, the whole science of electro- 

 magnetic induction, both pure and applied, 

 are only single illustrations of the wide 

 range which is covered by these discoveries. 

 But it is no more than just to mention 

 here that in the region of electromagnetic 



*The substance of the following summary of Far- 

 aday's discoveries and their aim was given by the 

 author in 1894 in the Electrical World in a series of 

 articles entitled 'The Faraday-Maxwell-Hertzian 

 epoch. ' 



induction a very fair, if not an equal, share 

 of the glory of original discovery belongs 

 to our own countryman, illustrious Joseph 

 Henry. 



Faraday can well afford to share these 

 honors with so great a physicist. For it 

 adds to his greatness to have it recorded in 

 the annals of science that the supreme 

 elfort in the life work of so great a physi- 

 cist as Joseph Henrj^ was the first step 

 only in the long series of Faraday's far- 

 reaching discoveries. The phenomena of 

 electro-magnetic induction seem to have 

 absorbed the smallest part of Faraday's at- 

 tention during the earliest period of his 

 electrical researches, and the question which 

 presents itself to every thoughtful student 

 of Faraday's 'Experimental Eesearches' is: 

 What called Faraday awaj^ so soon from 

 this important and promising field? For 

 who does not feel that the pleasure one 

 gets from reading Faraday's masterly story 

 of his discoveries in electro-magnetic in- 

 duction, given in the first part of Volume 

 I. of his 'Eesearches,' ends much too 

 soon? I even venture to suggest that 

 many a one among the students of Fara- 

 day, whose taste runs more in the direction 

 of estimating the value of a new discovery 

 by the immediate practical application to 

 which it can be put, has undoubtedly be- 

 moaned the fact that Faraday allowed him- 

 self to be drawn away so soon from his re- 

 searches in electro-magnetic induction to 

 matters so abstract as electro-chemistry, 

 electric discharges through gases, specific 

 inductive capacity of dielectrics, magneto- 

 crystallic action, magnetic properties of 

 fiames and gases, action of magnetism on 

 light, etc. 



But a careful review of Faraday's long 

 series of researches suggests a very inti- 

 mate connection between the numerous 

 and apparently independent parts of that 

 series. They are all just so many tributary 

 streams which flow into the same main 



