Precision pendulum regulator clock · England
George Graham's Astronomical Regulator Clocks
Partially verifiedGraham is credited with perfecting the deadbeat escapement (building on earlier work associated with Richard Towneley and Thomas Tompion, whose workshop Graham inherited) and with introducing a mercury-compensated pendulum to counteract thermal expansion.
Technical facts
- Escapement
- Deadbeat (graham) escapement
- Pendulum
- Mercury-compensated pendulum in Graham's later regulators, correcting for thermal expansion of the pendulum rod
Historical significance
- Graham is credited with perfecting the deadbeat escapement (building on earlier work associated with Richard Towneley and Thomas Tompion, whose workshop Graham inherited) and with introducing a mercury-compensated pendulum to counteract thermal expansion.
- His regulator clocks were used by Astronomers Royal Edmond Halley and James Bradley at the Royal Observatory, Greenwich, for exacting positional astronomy over long periods, making Graham's clocks working scientific instruments rather than purely decorative pieces.
- As a representative body of work rather than a single named object, specific surviving Graham regulators should each be individually catalogued and dated against the holding institution's own records.
Related photographs
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
- Britten, F. J., Old Clocks and Watches and Their Makers
- Royal Museums Greenwich, published catalogue notes on precision regulator clocks
Where sources disagree, the disagreement is stated rather than resolved silently.