Month-going watch
- Audio guide stop: 512
- Gallery: Room 39
- Maker: Ferdinand Berthoud
- Made in: Paris (France)
- Date: 1756-1762 (case)
- Object type: centre-seconds watch, half-quarter-repeating watch, calendar watch
- Museum number: 1958,1201.296
- Museum: The British Museum
- Collection record: British Museum website
- Image © The Trustees of the British Museum, shared under a CC BY-NC-SA 4.0 licence.
Listen to the free audio guide
About this object
Before you is a remarkable timepiece: a gold-cased, month-going cylinder watch made by Ferdinand Berthoud in Paris. This extraordinary watch operates for over 30 days on a single wind—an impressive feat for the 18th century.
Look closely at its white enamel dial marked with hour numerals and a rotating disc indicating true solar time. Its case features finely detailed astronomical instruments, including a ring dial, armillary sphere, and dividers—clearly made for a scientifically curious owner.
Inside, you'll find a half-quarter-repeat mechanism, center-seconds display, and a stop-lever function. The watch also automatically indicates the equation of time, a complex adjustment for solar and mean time differences.
Berthoud, a master watchmaker and fellow of the Royal Society, was renowned for both his craftsmanship and technical writing. This piece, included in his "Essai sur l'horlogerie," is a rare and fascinating example of his genius.
See it in person
Month-going watch is on display in Room 39 at the British Museum on Great Russell Street, Bloomsbury, London — free to enter. Choose British Museum on audioguide.london and type its audio guide stop number, 512, from the gallery label, or take a photo of it, to hear this free audio guide in six languages — no app download needed.
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