Robert Pennington, London, Movement No. 111/510, 51 mm, circa 1806

A rare boat chronometer
Case: mahogany box, sunk, screwed brass bowl. Dial: enamel, radial Roman hours, auxiliary seconds, signed, gold spade hands. Movm.: full plate movement, firegilt, chain/fusee, keywind, very fine florally hand-engraved balance cock, moulded pillars, spring detent escapement according to Thomas Earnshaw, Pennington's auxiliary compensation screw balance, freesprung blued helical balance spring, chatoned diamond endstone on balance, chatoned ruby endstone on escape wheel.

Robert Pennington
Robert Pennington was a renowned watchmaker who worked in London from about 1780 to his death in 1813. He is thought to have invented the screw balance - a very early version of which was used in the chronometer we have here. Pennington worked with William Howells and a number of other makers; between 1794 and 1799 the group produced at least 27 examples of Thomas Mudges's 'marine timekeepers' commissioned by Mudge’s son. Pennington also created the magnificent drawings of plates in "A Description with Plates" which Mudge Jr. published in 1799.