Wikinventia — Atlas of discoveries and inventions · Industrial Age

Coherer — Édouard Branly

1890 AD · Transmission: Global
PhysicsInstrumentFrench

Édouard Branly, a physicist and professor at the Institut Catholique de Paris, observes on 24 November 1890 that loose metal filings inside an insulating tube drastically change electrical resistance when exposed to Hertzian waves, and builds the coherer from that observation (the Branly effect). He built on Temistocle Calzecchi-Onesti's 1884-1886 experiments on metal filings and electric current. The coherer became the first widely used radio-wave detector and was the central receiving component in early wireless telegraphy systems, including Marconi's. Oliver Lodge refined the device in 1894 and coined the English term "coherer", a name Branly himself rejected as an inaccurate physical interpretation of the phenomenon.

InstitutionInstitut Catholique de Paris
Historical regionFrance (Third Republic)
Primary sourceBranly, É. — "Variations de conductibilité sous diverses influences électriques", Comptes Rendus de l'Académie des Sciences, vol. 111, pp. 785-787 (24 November 1890)
Secondary sourceIEEE Engineering and Technology History Wiki — "Milestones: Discovery of Radioconduction by Edouard Branly, 1890"
Original languageFrench
View this entry in the interactive atlas → View in graph →