COMPARA TIVE EXPERIMEN TS. ill 



the system into a kind of electio-magnet with numerous 

 poles, acting like Lontin's magnetic pinion. The induced 

 system is formed of a series of straight electro-magnets 

 B B, with expanded poles, and placed parallel to the axis of 

 the wheel crossing its teeth s s, N N, s s, so that when at one 

 end they are in contact with one tooth, at the other end they 

 touch die next tooth. As these teeth are polarized alternately 

 in opposite ways, it follows that for a certain position of the 

 wheel the electro-magnets will be polarized north-south, and 

 this will give rise to magneto-electric currents in the coils 

 which surround them; but when after leaving this position the 

 different parts of the polarized teeth are brought before the 

 different parts of the induced coils, there will be produced 

 these reversed polar currents and dynamic currents which 

 will carry on the magneto-electric action and augment it, as 

 in the machines of De Meritens. Thus, by very simple 

 constructive arrangements, a relatively powerful induction 

 machine is obtained. In the form of the machine working 

 in Jablochkoff's establishment, there are 36 induction coils, 

 and these are so joined as to give three series for tension, 

 each formed of 12 coils joined for quantity. There are, of 

 course, 36 teeth to the wheel, and under these conditions two 

 Jablochkoff candles are kept lighted, with a motive power 

 equivalent to that of two men, but under the influence of an 

 induction current coming from a small Gramme machine. In 

 this way the current from the Gramme machine is transformed 

 under favourable conditions into alternately reversed currents. 



COMPARATIVE EXPERIMENTS ON THE EFFECTS PRODUCED 

 BY THE DIFFERENT ELECTRO-MAGNETIC MACHINES. 



The study of the comparative effects produced by the 

 different machines suitable for the electric light is a matter 



