58 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



Edison. 



Thomson-Houston. Westinghouse. 



Brush-Swan. 



Edi-Swan 

 (single contact). 



Edi-Swan 

 (double contact). 



United States. 



Hawkeye. 



Ft. Wayne Jenny. 



Mather or Perkins. 



Loomis 



Schaeffer or National. Indianapolis Jenny. Siemens & Halske. 



Various Standard Bases in Use, 1892. 



