Universal equinoctial ring dial for all latitudes. This is a standard dial (see related terms) except for the following details:-

The bracket is attached by a swivel joint to a ring which slides in the grooved outer rim of the meridian ring. The latitude scale on the obverse of the meridian ring is divided clockwise from top 0°-[90°]-0°-90°-0°, and there is a scale for determining the solar altitude and zenith distance. On the obverse side and the inner-rim of the equinoctial ring are hour scales and the bridge has 'N' and 'S' marked on both sides. There is a date scale, a zodiac scale, a declination scale and the equinoxes are marked at 21 March and 22 September. The gnomon has a double pinhole with central concentric lathe-turned circles overlapping the bridge bars - this is the same type of pinhole gnomon as that on AST0173. The dial is signed 'I LINNELL LONDON'. It was probably not made by Linnell, who was an optical instrument maker, but was sold in his shop under his name.

For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.