Ring dial for latitude 47° North. It has an integral suspension piece (ring missing), next to which is stamped '47 GR' (the '4' has gone over the edge of the ring). This is presumably the latitude. On the outer face is a date scale either side of the central channel, stamped with the initials of the months. The equinoxes are marked at approximately 20 March and 20 September. A bridging arc is set within the ring and is stamped with an hour scale. It also carries an impression of the maker's initials: 'P S'.

The ring has a brass box lined with modern red material. The lid is divided into a seven by seven grid for the perpetual calendar. The sides of the box are marked with the Italian hour of midday (for a latitude of approximately 47°) and the bottom of the box has a dial showing the length of day and the hours of sunrise in concentric circles. All the engraving on the box is very crude. While the dial is a fairly typical genuine instrument, the box in which it has been kept is a 20th century Italian fake. There is also a perpetual calendar marked on the lid of the box, but it demonstrates a lack of understanding of such calendars. The problems with the box are indicated by the style of numbering, which is modern, and the quality of the engraving. The use of L for 'Luglio' (July) shows that the box was made in Italy.

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