Diptych dial for 49° North. This miniature diptych dial consists of two leaves that fold flat when not in use. Leaf Ia is blank except for a double-lined border. Leaf Ib contains the vertical dial with hour-lines radiating from a double circle. Within the circle are five trefoil motifs and a snowflake motif. The leaf has a double-lined border. Leaf IIa features the compass with the hours for the horizontal dial set around it. The string gnomon is broken.

The compass has the cardinal points marked in Latin and is offset 20° West of North to allow for magnetic variation. The covering glass plate is held in place by a metal ring. There is a fleur-de-lys on the right-hand side of the compass and Leonhard Andreas Karner's makers mark - a hand - appears on the left-hand side of the compass. At the bottom of the leaf are three trefoil motifs and, as on leaf Ib, there is a double-lined border. A brass pin for keeping the leaves aligned when closed is on the bottom right. Leaf lIb is blank. The leaves have a brass hook fastener and a single brass hook for holding the dial open.

Miniature diptych dials from this period are usually made from a combination of wood and ivory (see AST0254 and AST0414). As the 18th century wore on, an increasing number of all-wood dials were produced. This is probably one of the earlier ones.

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