714 



ELECTRO-MAGNETIC ENGINES. 



screws. The positive pole being connected with /, the 

 current enters the spiral of the horse-shoe at a, and 

 from the direction which it has there it follows that a 



FIG. 362 (A an. proj, ,- A, B, C, % real size). 



is a south pole, while b becomes a north pole. From b 

 the current passes to the semicircular piece g, and enters 

 the spiral of the straight electro-magnet at d, making d 

 a north pole and c a south pole. Finally the current 



