Seasonal inclining dial. This instrument comprises a rectangular universal equinoctial dial with an hour-plate hinged to the base-plate. The obverse side of the base-plate has a scale for the 24 Chinese seasons with 12 divisions marked on it. The hour-plate is cut from a rectangle and has a quadrant arc along which the time scale is drawn. The gnomon is provided by a vertical piece standing up from the bottom of the time scale and is shaped into a point at the top. The bottom section of the hour-plate is shaped and engraved with vine patterns. It carries a pivoted strut in its centre by which the dial can be adjusted in conjunction with the scale on the base-plate.

The time scale is divided into three main sections. Each of these is subdivided into two sections, which are numbered in Japanese and further subdivided into five parts. There is a decorative border below the time arc.

This unusual Japanese 'pseudo-equinoctial' dial marks the hours according to the Japanese system but the scale on the base-plate is similar to that used by the Chinese, giving divisions according to season rather than a latitude scale. This dial is, therefore, a seasonal inclining or 'pseudo-equinoctial' dial.

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