Universal equinoctial dial for latitudes 3°-90° North. The dial-plate has a latitude scale on its West side divided [3°]-90°, and has floral decoration in all four corners. Hinged to its North side, the hour-circle's inner rim is numbered IIII-XII, I-VIII. A strut across the East-West diameter supports a thin brass rod gnomon and a pivoted strut on the outside of the hour ring is used for setting the latitude. Hinged to the South side of the dial-plate, a support holds a brass plumb line and bob. Also contained on the dial-plate is a silvered compass with the cardinal points named by Latin initials.

A degree scale for the magnetic variation is divided around North, 30°-[0°]-30°. The variation is indicated by a central rotatable disc, which is worked by a knob on the underside of the base-plate. It is decorated with a rose and carries a fleur-de-lys to indicate magnetic North. The replacement needle is blued at its North end and surmounted by a brass pivot. A glass plate covers all. The dial-plate is supported by four brass screw feet with shaped heads in the corners.

This instrument carries a German-type hour ring, but the decoration is more in the French style and the use of a fleur-de-lys to indicate magnetic North is more common on French instruments.

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