Thomson's Mirror Galvanometer, 1858

Made:
1858 in Glasgow
maker:
White & Barr

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

Creative Commons LicenseThis image is released under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Buy this image as a print 

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

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

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

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

(Lord Kelvin) Thomson's mirror galvanometer (land type) used at Valentia Island end of the original Atlantic cable, made by White and Barr, Glasgow, Scotland, 1858.

A mirror galvanometer is a particularly sensitive electrical indicating instrument and was used to detect the extremely weak currents received through long submarine cables. Instead of a needle indicator, a mirror with a bar magnet cemented on the back is suspended on silk threads within the coil. A beam of light shone on the mirror is reflected on to a scale card some distance away, thus magnifying any movement of the mirror. This instrument was used at the Valentia Island end of the 1858 transatlantic telegraph cable to receive signals from Newfoundland. Unfortunately, the cable failed after less than a month. The mirror galvanometer became the standard instrument for receiving telegraph messages, but it did have a disadvantage in that it needed two operators - one to read and call the signal, and another to write the message down. This problem was solved by Thomson when he invented the siphon recorder, which used a glass tube dipped ink to record to movements of the cable on a moving tape, to then be read and decoded.

On display

Science Museum: Information Age Gallery: Cable

If you are visiting to see this object, please contact us in advance to make sure that it will be on display.

Related people

Details

Category:
Telecommunications
Object Number:
1907-105
Materials:
brass (copper, copper (metal), leather, mahogany (wood), plastic (unidentified), zinc alloy)
type:
galvanometer
taxonomy:
  • furnishing and equipment
  • measuring device - instrument
status:
Permanent collection

Cite this page

Rights

We encourage the use and reuse of our collection data.


Data in the title, made, maker and details fields are released under Creative Commons Zero


Descriptions and all other text content are licensed under a Creative Commons Attribution 4.0 licence

Using our data

Download

Download catalogue entry as json

Our records are constantly being enhanced and improved, but please note that we cannot guarantee the accuracy of any information shown on this website.