Strowger calling dial, 1900

Made:
1900 in United States
Calling dial from a Strowger telephone, Automatic Electric Company, America, 1900.
      This calling dial was the first Calling dial from a Strowger telephone, Automatic Electric Company, America, 1900. metal (unknown). SCM - Calling dial from a Strowger telephone, Automatic Electric Company, America, 1900. metal (unknown). SCM -

Buy this image as a print 

Buy

License this image for commercial use at Science and Society Picture Library

License

Buy this image as a print 

Buy

License this image for commercial use at Science and Society Picture Library

License

Buy this image as a print 

Buy

License this image for commercial use at Science and Society Picture Library

License

Calling dial from a Strowger telephone, Automatic Electric Company, America, 1900. This calling dial was the first
Science Museum Group Collection
© The Board of Trustees of the Science Museum

Calling dial from a Strowger telephone, Automatic Electric Company, America, 1900. metal (unknown). SCM -
Science Museum Group Collection
© The Board of Trustees of the Science Museum

Calling dial from a Strowger telephone, Automatic Electric Company, America, 1900. metal (unknown). SCM -
Science Museum Group Collection
© The Board of Trustees of the Science Museum

Strowger calling dial, made by the Automatic Electric Company, United States, 1900.

This calling dial was the first design to use the 'three wire' system which had an earth connection in addition to the two telephone lines connecting to the exchange. Dialling impulses were sent alternately along the two exchange wires, and the earth connection provided the return path. The 'three wire' system was standard until 1907.

Details

Category:
Telecommunications
Object Number:
1926-1057/1
Measurements:
Mount with calling dial attached: 185 mm x 38 mm x 51 mm,
type:
telephone component
taxonomy:
  • component - object
  • telephone
credit:
Donated by BT Heritage and Archives