Diptych dial. The dial is divided into two leaves that fold together when not in use. Leaf Ia carries a lunar volvelle which consists of a fixed disc with a lunar-age scale and a rotatable disc, both marked with Chinese characters. On leaf Ib, in place of a vertical dial, is a table for moonrise and moonset, also giving the direction of the moon. Leaf IIa carries the horizontal dial, in the centre of which is a compass with the cardinal points marked in black around it (red for South). The compass is of a grey metal and the meridian line is marked. It has a steel needle, reddened at its South end. There are 13 holes down the sides of the dial for setting the angle of the lunar dial. The string gnomon is missing.

Leaf IIb gives instructions on the dial's use in Chinese characters: 'Use of sundial: direct the red end of the needle to South, observe the string shadow and so know the time exactly. Moon dial's method of use: direct the red end of the needle to the South. Next pull the brass screw out and put it into the seasonal hole. Move the hand of the rotating dial to the day of the month. Put the gnomon needle into the centre [of the Moon dial] and set it in the moonlight. Observe the needle's shadow and so find the time without error'. This is followed by the district, village and the name of the maker: 'Xin-An, Xiu-Li, Wang Yang-Qi'.

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