D8942

Universal equinoctial ring dial Long Caption: Standing universal equinoctial ring dial for all latitudes. This 'standing' dial is similar to ordinary universal equinoctial ring dials, but can be oriented by means of the compass if the magnetic variation is known. Alternatively, the self-orienting nature of the dial means that it can be used to find the variation once the dial is correctly oriented. Credit line: © National Maritime Museum, Greenwich, London Object: AST0158 Artist: Thomas Heath Date: mid 18th century Medium: brass; glass Size: height: 350 mm; diameter of base: 182; diameter of meridian ring: 239 Click here to buy a bespoke print of this image.