細節
A George III mahogany and brass-mounted one-day marine chronometer
John Roger Arnold, London, No.250. Circa 1805
BOX: two-tier with sliding viewing panel to top lid, green velvet-lined, moulded lip to the lower section for setting box into a chart table, ivory roundel inscribed 250, brass drop-down handles, square section brass gimbal and cylindrical brass bowl with screw fixing, its underside with lead balancing weight and spring-loaded winding cover, brass bezel with convex glass; box key
DIAL: silvered and engraved, with dot minute track and seconds ring, signed ARNOLD/London/250, hands of blued steel
MOVEMENT: plain plates joined by four pillars (two pinned), signed on the top plate John R Arnold London Inv:et Fecit No.250, chain and fusee with maintaining power; numbered tipsy key
ESCAPEMENT: Arnold spring detent with cut bimetallic balance with adjustable heat compensatation weights at the screw-threaded outer ends (Z balance), blued steel helical spring with diamond endstone
172 mm. square box, 80 mm. diameter dial