Universal equinoctial ring dial

Universal equinoctial ring dial for latitudes 0°-90° North. Standard dial (see related terms) except for the following details:-

The dial is for northern latitudes only and the degree scale on the meridian ring is divided clockwise from top [0°]-[90°]. The remainder of the obverse and reverse sides are filled with a table of latitudes primarily consisting of places in Italy. On the equinoctial ring, there is a main hour scale and the table of latitudes is continued. A rotatable ring on the inner rim carries an Italian hours scale. There is a date scale, but no declination scale and the equinoxes are given at 20 March and 22 September. There is elaborate leaf engraving on the stops and bridge ends. The stops for the equinoctial ring have additional hinged stops, which fold down once the equinoctial ring is in place to lock it in position.
This rather heavy dial is even more ornately decorated than the other French dials of this type. The rotatable innermost ring carrying Italian hours is very unusual, and, combined with the large number of Italian towns listed, suggests that the instrument was made for an Italian or a Frenchman who travelled extensively in Italy. It is signed 'Butterfield AParis' on the obverse side of the meridian ring.

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

Object Details

ID: AST0314
Collection: Astronomical and navigational instruments
Type: Universal equinoctial ring dial
Display location: Not on display
Creator: Butterfield, Michael
Date made: 1675-1715
Credit: National Maritime Museum, Greenwich, London, Caird Collection
Measurements: Overall: 4.5 x 133.5 mm