129 



The following paper was read at the Ordinary Meeting of 

 the Society, held April loth, 1873 : — 



" On some improvements in Electro-magnetic Induction 

 Machines," by Henry Wilde, Esq. 



Soon after the announcement by the author (m 1866) of 

 the discovery that electric currents and magnets, indefin- 

 itely weak, could, by induction and transmutation, produce 

 magnets and currents of indefinite strength,* a number of 

 electricians suggested other methods by which this principle 

 could be exhibited and more powerful results obtained than 

 those which the author described. The most interesting as 

 well as the most useful of these suggestions was to augment 

 the magnetic force of the elementary magnet, by transmit- 

 ting the direct current from the armature of a magneto- 

 electric, or an electro-magnetic machine through wires 

 surrounding its own permanent or electro-magnet, in such 

 a direction as to intensify its magnetism until, by a series 

 of actions and reactions of the armature and the magnet on 

 each other, an exalted degree of magnetism in the iron or 

 steel was obtained. 



This idea seems to have occurred to several electro- 

 mechanicians almost simultaneously in England, German}^, 

 and America. In a letter to the Engineer newspaper of 

 July 20th, 1866, Mr. Murray, after referring to the author's 

 experiments, writes that he Avishes to point out a variety of 

 the principles embodied in the machine the author had 

 described, which, he says, is so obvious that it cannot fail 

 to be hit upon by some inventor before long, and warns 

 anyone whom it may strike against patenting the idea, 

 seeing that he had already constructed a machine upon the 

 plan. Mr. Murray then states that, " Whereas Mr. Wilde, 

 " beginning with an ordinary magneto-electric machine, 

 " uses the current obtained from it to charge a powerful 



* Proceedmgs of the Koyal Society, April 26, 1866. Philosophical Trans- 

 actions, Yol. clvii., 1867. Philosophical Magazine, S. 4, Vol. xxxiv. 



