A good, early silver cased pocket chronometer by John Roger Arnold, number 2044 the movement recased, (fits well, winding hole repositioned) in London 1806 hallmarked inner and outer cases. Arnold detent escapement planted in slot in back plate. Full plate movement with helical steel balance spring and Arnold 'Z' balance. Signed Jn. R. Arnold, London, Invt et Fecit. 2044. White enamel dial, Roman numerals, rail track minutes, subsidiary seconds dial at VI, signed Arnold, 2044. John Rodger Arnold Jnr (1769-1843) served as an apprentice to his father John Rodger Arnold Snr and the famous Swiss watchmaker Abraham Louis Breguet. His father started the company Arnold & Son in 1787, Arnold Jnr continued the business after his father's death in 1799, becoming Master of the Worshipful Company of Clockmakers in 1817. He took John Dent into partnerships between 1830 and 1840. After Arnold's death in 1843 the company was bought by Charles Frodsham.