An early 19th century and later marine chronometer, the two-day chain fusee movement with Earnshaw type spring detent and bimetallic balance, the backplate engraved 'Parkinson & Frodsham Change Alley, London', the silvered circular dial with Roman hour numerals, subsidiary state of wind and seconds dials, inscribed 'Parkinson & Frodsham Change Alley, London' and numbered '1236.', housed in a later brass bowl hung in gimbals, within a later brass bound mahogany three-tier box with painted simulated rosewood decoration, total height 21.2cm (restoration).