On Improvements in Electromagnetic Induction Machines. 439 



together, or at least may do so, for all that this argument proves 

 to the contrary. 



I am, Gentlemen, 



Your obedient Servant, 



John W. Strutt. 

 May ]5, 1873. 



LVI. On some Improvements in Electromagnetic Induction Ma- 

 chines. By H. Wilde, Esq.* 



[With a Plate.] 



SOON after my announcement (in 1866) of the discovery that 

 electric currents and magnets indefinitely weak could, by 

 induction and transmutation, produce magnets and currents of 

 indefinite strength f, a number of electricians suggested other 

 methods by which this principle could be exhibited and more 

 powerful results obtained than those which I had described. 



The most interesting as well as the most useful of these sug- 

 gestions was to augment the magnetic force of the elementary 

 magnet, by transmitting the direct current from the armature of 

 a magneto-electric or an electromagnetic machine through wires 

 surrounding its own permanent or electromagnet, in such a direc- 

 tion 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-mechani- 

 cians almost simultaneously in England, Germany, and America. 

 In a letter to the 'Engineer'' newspaper of July 20, 1866, Mr. 

 Murray, after referring to my experiments, writes that he wishes 

 to point out a variety of the principles embodied in the machine 

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

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

 whom it may strike against patenting the idea, seeing that he 

 had already constructed a machine upon the plan. Mr. Mur- 

 ray then states that " whereas Mr. Wilde, beginning with an 

 ordinary magneto- electric machine, uses the current obtained 

 from it to charge a powerful electromagnet, and from this ob- 

 tains a second and more powerful current, which, used in like 

 manner, produces one still more intense, I, using only a single 

 machine, pass the currents from its armatures through wires 

 coiled round the permanent magnets in such a direction as to 



* Communicated by the Author, having been read at a Meeting of the 

 Literary and Philosophical Society of Manchester, April 15, 18/3. 



t Proceedings of the Royal Society, April 26, 1866. Phil. Trans, 

 vol. clvii. (1867). Phil. Mag. S. 4. vol.xxxiv. p. 81. 



