Verge escapement watch with pirouette by Peter Debaufre, London c.1700, with late 18th century adaptions. Silver case with small aperture to show balance. Originally the watch would have had an outer case, but this is now missing. The silver dial has raised figures with blued steel beetle and poker hands and a subsidiary seconds dial with decorative pierced hand. Movement with verge escapement and pirouette. A stop piece engages with the contrate wheel, and the balance cock has a rim with two thin arms to show the pirouette balance, which has a spring with 4 turns. Signed on the backplate 'Peter Debaufre London' (Peter is under the foot of the balance cock).

A 'Pirouette' is a device in which the balance is not on the same axis as the verge, but on a separate arbor and geared to the verge, so that it turns much more rapidly. In this case a wheel of 60 teeth on the verge-staff gears with a pinion of 6 leaves on the balance-staff which thus has an arc of about 2½ turns. Although the watch is signed Debaufre and made around 1700, the beautiful verge escapement with a pirouette was undoubtedly the late 18th century work of the clockmakers Alexander Cumming. In May 1815, the Royal Clockmaker Benjamin Lewis Vulliamy attended the sale of Cumming's estate. He bought three items for the library (later museum) of the Worshipful Company of Clockmakers including this which was described as 'an original Leaver Escapement watch with verge – vibrates 1/2 seconds –supposed unique invention £3-0-0'.

Clockmakers Museum No. 77