Magnetic dial and thermometer for latitude 51° 30' North. This instrument is set on a chipped octagonal ivory base which in turn sits on a turned circular wooden base. Extending out of the ivory base is a circular ivory pillar which carries a mercury in glass thermometer, giving temperatures in Fahrenheit and Réaumur. The scales are marked to indicate the following: 'Freezing', 'Temperate', 'Sumr heat', 'Blood heat' and 'Fever heat'. An octagonal plate on top of the pillar contains the horizontal dial, set under a glass dome. The hour-plate is set on to a compass card on which 64 points are marked. There is also an hour ring and a shaped brass gnomon.

Similar instruments are in the Whipple museum (accession no. Wh: 0893) and the MHS, Oxford (new inventory no. 45668). The latter is signed 'M. PILLISCHER', with a London address. The compass card of the NMM dial is marked in a similar style to the ordinary magnetic dials produced in England at this time.

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