Robert Roskell

A GEORGE III 18CT GOLD PAIR-CASED PATENT RACK-LEVER POCKET WATCH ROBERT ROSKELL, LIVERPOOL, 1802 The gilt full plate fusee movement with four columnar pillars pinned through the backplate, plain stop-iron block and rack lever escapement regulated by sprung three-arm steel balance, the backplate with floral bright-cut chased and engraved balance cock with diamond endstone, the foot engraved with further foliage over oval cartouche inscribed PATENT , flanked by S/F regulation lever opposing applied barrel pivot plate signed R't Roskell, LIVERPOOL over serial number 3611 , with gilt brass dust cover, with cream enamel Roman numeral dial and fine pierced gold spade hands, the inner case with oval section suspension post with bow and the outer with moulded rim to circumference and bezel aperture, both cases marked for Sheffield 1802 makers S.B . The pillar plate 4cm (1.1ins) diameter, the outer case 5.3cm (2.125ins) diameter. Robert Roskell is recorded in Baillie, G.H. Watchmakers & Clockmakers of the World as working in Liverpool and London 1798-1830; prior to that he was in partnership with O'Niell. The rack lever escapement was first devised by the Abbe de Hautefeuille in 1722 as an attempt to incorporate a clock style deadbeat escapement into a watch. The invention was apparently neglected until Ferdinand Berthoud experimented with a variation in his marine timekeepers. Peter Litherland subsequently took out a Patent (no. 1830) in 1791. His design became popular with Liverpool and other makers up until around 1815-20 when Edward Massey introduced his design of detached lever escapement. Massey's design was subsequently developed into the standard form known as the English lever escapement.