A Regency mahogany one-day marine chronometer with O+Z balance
John Roger Arnold No. 210, circa 1815
The white enamel dial signed Arnold 210, Roman hour numerals, outer minute chapter with five minute intermarkers, subsidiary seconds dial (at VI), blued steel hands, top-plate inscribed Jn R Arnold, London, Inv. et Fecit No. 210, Arnold escapement, Z+O balance, blued steel helical balance spring, Arnold detent with jewelled locking stone, engine-turned bezel with convex glass, brass bowl and gimbal in (replacement) brass-bound three-tier mahogany box, the middle section with (later) inset bone disc inscibed 210, external brass drop handle
75 mm dial diam., box 155 mm sq.