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THE HEW ELECTROMAGNETIC MACHINES. 
HE able disquisition upon the conversion of motive force 
into electro-magnetism made by Mr. Wilde in his paper 
last year before the Royal Society, gave an additional impetus 
to other electricians to make advances in the same direction, 
and both Mr. C. W. Siemens and Professor Wheatstone have 
since described original views and exhibited models of machines 
constructed upon their respective principles. Mr. Ladd, too, 
the eminent philosophical instrument maker, of Beak Street, 
also produced before the Royal Society, in a practical model, a 
long-conceived idea of his assistant, Mr. Tisley, a few evenings 
after the exhibition, at the president’s soiree, of the magnificent 
10-inch machine of Mr. Wilde’s. Mr. Ladd has now a larger 
machine of two-horse power at the Paris Exhibition ; and at 
the recent soiree of the Civil Engineers there was at work one 
of Mr. Siemens’ beacon apparatus for flashing lights. 
Of all these plans, however, Mr. Wilde’s is the only one that 
has been practically put to the test on the large scale. We 
therefore begin our review with a description of that magnifi- 
cent machine we have had the opportunity of seeing develop 
such a torrent of electrical force. Whether this force be utilised 
in its intensity as light, or its quactity used as a heating power, 
what Mr. Wilde has shown causes the strongest convictions to 
arise in the mind that electricity generated by engine power 
will be amongst the practical operations of future industry, 
and will take a rank no one has hitherto conceived. 
We are all of us familiar with the electric light as supplied 
by the currents from various kinds of voltaic batteries in which 
chemical action gives rise to a continuous flow of electrical force. 
All of us, too, are familiar with the conversion of magnetism 
through its intensification in the induction-coil into luminous 
electric sparks. And, finally, very few indeed there must be 
who did not see Mr. Holmes’ magneto -electric light in the Great 
International Exhibition of 1862, in which the currents were 
gained from numerous keepers set on the periphery of a large 
wheel passing between the poles of a corresponding circle of 
By S. J. MACK1E. 
