Inclining dial for latitudes 0°-60° North. This square shaped dial has a brass base-plate, a compass and two brass spirit levels. Hinged to the North end of the base-plate is the hour-plate, on which sits a triangular brass polar gnomon. There is a slot on the West side of the hour-plate through which the latitude arc would once have passed. The hour and minute circles are engraved on a scroll. Within this is a degree scale based on the projection from an equinoctial circle, which can be used in conjunction with the vertical edge of the gnomon to measure the solar azimuth. Within this are two scales for the equation of time, which is unusual for an inclining dial.

In the centre is a radial table of latitudes for towns in Britain and also in Europe. The arms of the Duke of Somerset are set between the ends of the hour scale. The compass has a raised degree circle with eight points marked by English initials. On the West side of the are two small mounts on to which the hinged latitude arc would once have been attached. Two orthogonal brass bubble levels, filled with a dark liquid, are set on the plate. Since the latitude arc is missing, the latitudes at which the dial was intended to be used cannot be given with certainty but the base latitude of the hour plate is 60° North, which suggests a range of 0°-60° North. The dial is signed 'I * Sisson LONDON'.

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