Lot 522

William Morgan, Dublin, Movement No. 441, 54 mm, 147 g, circa 1802
A very fine pair-cased pocket watch with a rare rack-lever escapement according to the patent of Peter Litherland
Case: outer case - 18k rose gold, polished, à goutte, case maker's punch mark "TH" (Thomas Helsby, Liverpool). Inner case - 18k rose gold, polished, case maker's punch mark "TH" (Thomas Helsby, Liverpool), movement protection cap. Dial: enamel, radial Roman numerals, pierced filigree gold hands. Movm.: full plate movement, keywind, applied florally engraved ornaments, frosted, gilt, signed, chain/fusee, "Patent P.L." (Peter Litherland), three-arm steel balance, freesprung blued balance spring, fine florally engraved balance cock, engraved regulator scale with long index hand, chatoned diamond endstone on balance.
Peter Litherland (1756–1805)
Peter Litherland was a watchmaker and inventor. He was born in Warrington and later moved to Liverpool, which was then the centre of the watchmaking trade. In 1791 he patented the rack lever escapement for watches, which was more accurate than the commonly used verge escapement. One of his watches is in display in the World Museum Liverpool.
Source: http://en.wikipedia.org/wiki/Peter_Litherland, as of 02/23/2015.