[typescript] Patent application for Improvement in Electric Telephone Transmitters.

Bergmann, Sigmund

1884-09-15

1880-1889

Patent Application

Patent application

Telephone

D8468ZBM

D8468

[D8468ZBM], Patent Application, Sigmund Bergmann, September 15th, 1884

76:787

Thomas Edison National Historical Park

Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University