88 



ELECTRIC LIGHTING. 



are then, inverse induced currents by the fact of the approach 

 and withdrawal of the expansions B and A, direct induced 

 currents during the passage of the length of core A B before 



the magnetic pole, and direct induced currents resulting from 

 the passage of the spires before N. All the causes of induc- 

 tion are therefore united in this combination. 



It will be observed that the action which we have just 

 studied in a single section of the ring may take place simul- 

 taneously in all the others, and that there are also added 



