Coherer, one of two, designed and used by Edouard Branly

1885-1940 in Europe
Edouard Branly

Buy this image as a print 

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

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

Coherer, one of two, designed and used by Edouard Branly, unsigned, Europe, 1885-1940 (Part of Branly collection? A182822, B3875)

Coherers designed and used by Edouard Branly, unknown maker, 1885-1940.

The coherer was the first practical device for detecting Hertzian waves. It was devised by French physicist Edouard Branly in about 1890 who did not, however, investigate its use for detecting Hertzian waves. Its most familiar form was a tube containing metal filings or turnings loosely packed between metal plugs. This presented a high resistance to current but changed to low resistance in the presence of electric waves because the filings 'cohered' or stuck together. In order to restore the high-resistance state the tube needed to be given a mechanical tap or jolt. This coherer came from a collection of apparatus associated with Branly, but it is not known if it dates from before or after 1894.


Object Number:
copper (alloy), glass, metal (unknown) and paper (fibre product)
  • component - object
  • radio receiver
On loan from Wellcome Trust

Cite this page


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 catalogue entry as json

View manifest in IIIF viewer

Add to Animal Crossing Art Generator

Download manifest IIIF

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