BELFAST 



NATURAL HISTORY & PHILOSOPHICAL SOCIETY 



SESSION 1896-97. 



jrd November, l8g6. 



Professor J. D. Everett, f.r.s,, d.c.l., delivered an 

 Inaugural Address on 



"RECENT ADVANCES IN ELECTRICITY." 



Quite a revolutionary change has come over the theory and 

 practice of electricity and magnetism during recent years. It is 

 not my purpose to-night to speak of the enormous advance which 

 has been made in the means of producing electricity, and in 

 modes of applying it to human wants, but rather of the change 

 which has come over the thoughts of electricians in regard to the 

 nature of electrical phenomena. Faraday laid the foundation 

 of this change, and urged his views strongly in many passages 

 of his " Experimental Researches ;" at the same time that, by 

 his discovery of the production of electric currents in wires 

 by moving them in a magnetic field, he laid the foundation of 

 the methods by which electricity is now universally supplied. 

 According to the old views, non-conducting substances were 

 regarded as simply blocking the way and preventing the 

 escape of electricity from charged conductors. Faraday upset 

 this view by showing as an experimental fact that the capacity 

 of a condenser, though it is not changed by substituting one 

 metal for another in the conducting portions of the arrange- 

 ment, is materially changed by substituting one material for 



B 



