Marine chronometer movement by John Arnold, London, c.1775. White enamel dial with subsidiary seconds. Signed '.John Arnold, London, No 14'. Fusee movement with spring detent escapement and Z-balance. Signed on movement ‘John Arnold London Invt. et Fect. No. 14’.

This is a very early Arnold chronometer, which is likely to have started out fitted with a pivoted detent, and later replaced by Arnold with a spring detent c.1790. Presented to the Worshipful Company of Clockmakers by Charles Frodsham & Co., 1875. Clockmakers' Museum No. 600