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The Encyclopedia of Horology

England / Switzerland · c. 1780s–1820s

Detached Lever Escapement Refinements

Needs research

This period of refinement, rather than a single patent event, is what converted the lever escapement from an interesting idea into the dominant industrial escapement.

Following Mudge's original lever, Josiah Emery and other London makers built and sold detached lever watches in the 1780s, establishing it as a viable commercial escapement rather than a workshop curiosity.

Swiss and French makers subsequently refined the geometry (draw, drop, lock) across the early nineteenth century, converging on the club-tooth lever form still used today.

How to verify this yourself

Individual improvement patents from this period, where they exist, are held in The National Archives (Kew) under old patent enrolment series, and in the Bureau Suisse de la Propriété Intellectuelle for Swiss claims after Switzerland's patent law of 1888. Numbers are not asserted here because the enrolment records must be checked case by case.

Manufacturers known to have used it

  • English lever-watch makers of the Emery school
  • Swiss établissage trade from the 1820s

Related photographs

Chinese movement escapement and jewels
Chinese movement escapement and jewels — Hustvedt, CC BY-SA 3.0. Wikimedia Commons file page
Lever of a Watch Lever Escapement
Lever of a Watch Lever Escapement — Micky Aldridge from Finland, CC BY 2.0. Wikimedia Commons file page

No confidently matched photograph of this subject has been found yet. These photographs show a closely related record, and are not examples of the type described on this page.

Sources & references

  1. The National Archives (Kew), patent enrolment series — index only consulted, individual numbers not yet verified
  2. Britten, F. J., Old Clocks and Watches and Their Makers

Where sources disagree, the disagreement is stated rather than resolved silently.