1840
- Edouard Heuer, the founder of the watch manufacture Heuer, is born in Brügg, Canton of Bern, as Son of a shoemaker.
- Charles Weatstone, born in Gloucester, imagines the transmission of time using electro-chronometric counters.
- English engineer Bain builds a clock using electro-magnetic power.
- At the same time, English watchmakers Robert Molyneux and E.-J. Eiffe invent a balance wheel with auxiliary compensation for extreme temperatures, an idea also proposed by John Poole and Sir George Airy.
- Sir George Airy, director of the Greenwich Observatory, publishes an account of his experiments concerning the influence of terrestrial magnetism on the operation of chronometers.
- Louis Audemars in Le Brassus creates a pendant winding system. Similar systems are soon created by Breguet, Reymond-Bertaud, and Ad. Philippe in Paris, Ad. Nicole, a Swiss watchmaker established in London, Antoine LeCoultre in Le Sentier, and Sylvain Mairet in Le Locle.