1891.] The Faraday Centenary. 463 



celebrating was identified in a remarkable degree with the history of 

 this Institution. If they could not take credit for his birth, in other 

 respects they could hardly claim too much. During a connection of 

 fifty-four years, Faraday found tbere his opportunity, and for a large 

 part of the time his home. The simple story of his life must be 

 known to most who heard him. Fired by contact with the genius of 

 Davy, he volunteered his services in the laboratory of the Institution. 

 Davy, struck with the enthusiasm of the youth, gave him the desired 

 opportunity, and, as had been said, secured in Faraday not the least 

 of his discoveries. The early promise was indeed amply fulfilled, 

 and for a long period of years by his discoveries in chemistry and 

 electricity Faraday maintained the renown of the Royal Institution 

 and the honour of England in the eye of the civilised world. He 

 should not attempt in the time at his disposal to trace in any detail 

 the steps of that wonderful career. The task had already been per- 

 formed by able hands. In their own ' Proceedings' they had a vivid 

 sketch from the pen of one whose absence that day was a matter of 

 lively regret. Dr. Tyndall was a personal friend, had seen Faraday 

 at work, had enjoyed opportunities of watching the action of his mind 

 in face of a new idea. All that he could aim at was to recall, in a 

 fragmentary manner, some of Faraday's great achievements, and, if 

 possible, to estimate the position they held in contemporary science. 

 Whether they had regard to fundamental scientific import, or to 

 practical results, the first place must undoubtedly be assigned to the 

 great discovery of the induction of electrical currents. He proposed 

 first to show the experiment in something like its original form, and 

 then to pass on to some variations, with illustrations from the be- 

 haviour of a model, whose mechanical properties were analogous. 

 He was afraid that these elementary experiments would tax the 

 patience of many who heard him, but it was one of the difiiculties of 

 his task that Faraday's discoveries were so fundamental as to have 

 become familiar to all serious students of physics. 



The first experiment required them to establish in one coil of 

 copper wire an electric current by completing the communication 

 with a suitable battery; that was called the primary circuit, and 

 Faraday's discovery was this : That at the moment of the starting or 

 stopping of the primary current in a neighbouring circuit, in the 

 ordinary sense of the words completely detached, there was a ten- 

 dency to induce a current. He had said that those two circuits were 

 perfectly distinct, and they were distinct in the sense that there was 

 no conducting communication between them, but, of course, the im- 

 portance of the experiment resided in this — that it proved that in 

 some sense the circuits were not distinct ; that an electric current 

 circulating in one does produce an effect in the other, an effect 

 which is propagated across a perfectly blank space occupied by air, 

 and which might equally well have been occupied by vacuum. It 

 might appear that that was a very simple and easy experiment, and 

 of course it was so in a modern laboratory, but it was otherwise at 



