Dieppe magnetic azimuth dial for 50° North (0°-80° North for the equinoctial dial). Standard Dieppe magnetic azimuth dial (see related terms) except for the following details:-

The dial is split into four leaves. Leaf Ia displays the equinoctial dial and the polar dial, which is edged on both sides by typical Dieppe 'pecked' ornamentation. Leaf Ib comprises a lunar volvelle made of pewter. Leaf IIa contains the horizontal and magnetic azimuth dials. The horizontal hour scale is marked around the edges of the compass bowl. This dial has a red string gnomon attached between the two leaves and a pewter elliptical scale. The cardinal points are named in Latin on the compass and there is a gazetteer for 19 French towns. The needle has an open circle for North and a crescent for South. Leaf IIb features a pewter volvelle that has become detached from the azimuth dial. The dial has silver hinges and the hook fasteners are missing.

The inclusion of a polar dial is common on Dieppe dials, but there are only three in the NMM collection (see AST0498 and AST0362). As with AST0498 and AST0508, this instrument includes a horizontal dial. The compass card is the same as that of AST0362. The maker appears to have favoured a different form of ornamentation from that normally used on these dials, with a swirling motif replacing the pecked motif apart from along the edges of the polar dial.

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