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

Made:
1885-1940 in Europe
designer:
Edouard Branly
maker:
Unknown

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.

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.

Details

Category:
Telecommunications
Object Number:
2015-541
Materials:
copper (alloy), glass, metal (unknown), paper (fibre product)
Measurements:
overall: Length = 152mm, Diameter = 11mm., Weight = 0.062Kg
type:
coherer
taxonomy:
  • component - object
  • radio receiver
credit:
On loan from Wellcome Trust
status:
Loan

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

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.