Portable double-needle telegraph and test set, 1850

Portable double-needle telegraph and test set, 1850 Portable double-needle telegraph and test set, 1850 Portable double-needle telegraph and test set, 1850 Portable double-needle telegraph and test set, 1850

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Creative Commons LicenseThis image is released under a CC BY-SA 4.0 Licence

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Creative Commons LicenseThis image is released under a CC BY-SA 4.0 Licence

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

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Creative Commons LicenseThis image is released under a CC BY-SA 4.0 Licence

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Science Museum Group Collection
© The Board of Trustees of the Science Museum

Science Museum Group Collection
© The Board of Trustees of the Science Museum

Science Museum Group Collection
© The Board of Trustees of the Science Museum

Science Museum Group Collection
© The Board of Trustees of the Science Museum

Portable double-needle telegraph and test set, with removable wooden cover, unknown maker, possibly British, 1850.

This small instrument is both a telegraph instrument and a test set. It was compact enough to be carried by the telegraph lineman when inspecting and repairing telegraph wires. It worked using two pairs of press-buttons at the back of the case. When the instrument was required to work as a galvanometer (an instrument for detecting electric currents), a lever inside the case withdraws the needle stops, allowing the needles to swing fully across the dials. With the ivory stops in position the needles were used to send and receive messages using the standard double-needle code.

Details

Category:
Telecommunications
Object Number:
2004-123
Materials:
wood (unidentified), metal (unknown) and glass
Measurements:
overall: 165 mm x 220 mm x 137 mm, 3.01kg
type:
telegraph
credit:
Donated by BT Heritage and Archives