Dieppe magnetic azimuth dial for latitudes 0°-80° North. Standard Dieppe magnetic azimuth dial (see related terms) except for the following details:-

The dial is divided into four leaves that fold flat when not in use. On leaf Ia is an hour scale. Leaf Ib carries a lunar volvelle. Leaf IIa contains the horizontal dial and the magnetic azimuth dial. An hour scale for the horizontal dial surrounds the compass well. The cardinal points are named in Latin on the compass and there is also a gazetteer for 18 French towns. The string gnomon that would have been used with this dial is missing. On leaf IIb, the volvelle is brass and there is a brass clasp over the slot for the pin gnomon. The dial is signed 'Jacques Senecal ADieppe fecit'.

Like AST0498 (also made in the Senecal workshop), this instrument has a horizontal dial and can be oriented in the same way. Jacques Senecal seems to have favoured a more 'spiky' version of the Dieppe ornamentation (see Lloyd [1992], p. 124, which closely resembles this instrument). Other dials by Jacques Senecal are in the MHS, Oxford (new inventory no. 51567) and a private collection in Belgium.

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