100 



DRUM MACHINES. 



The distinctive feature of the machines 

 comprised under this title is that the 

 armature-coils do not surround the core, 

 but are arranged on one side of it. As 

 examples, may be mentioned the Westing- 

 house, the Lowrie-Parker, and the 

 Zipernowsky machines. 



Fig. 22 



The Westinghouse Alternator. 



The armature-core of this machine is 

 of cylindrical shape, and consists of thin 

 iron plates, as in an ordinary drum machine 

 for continuous currents. To provide 

 internal cooliug surfaces, the plates have 

 large holes cut out of their surface, form- 

 ing, when put together, tunnels, going 

 from end to end, through which the air 



