Crescent dial for latitudes 0°-90° North. This is a standard dial (see related terms), except for the following details:-

The base-plate, leg and levelling screws are all gilt-brass. The table of latitudes is titled 'Elevatio Poli', and covers European cities, including Marseille, Kracow, Brest and Vienna. The cardinal points are marked on the sides of the plate in Latin. It has a brass-gilt hour plate with silver hour scales, a date scale and a gnomon. The latitude arc and the plumb bob support are silver, but the plumb bob is made of gilt brass. The dial has a square black fishskin case with red velvet lining and two hook fasteners.

This is the only one of the three crescent dials in the NMM collection to be signed by the maker: 'Johan Martin in Augspurg 48'. In all other respects, it closely resembles the other two dials. Similar signed dials are in the Huelsmann Collection in Bielefeld, two in the MHS, Oxford (new inventory nos. 50155 and 52827) and a further example in the Whipple Museum (accession no. Wh: 0252).

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