Astronomical compendium for latitudes 0°-74° North. It has a lid and a base that open, leaving a central ring. The instrument includes a Rojas projection and a volvelle for calculating the length of day/night which both appear on the outside of the lid. Inside the lid is an engraved map of central Europe marked with rivers and numerous towns. Attached to the centre is a radial index arm. The equinoctial ring is made of silver rimmed with brass; its main ring revolves. Outside, it has two lunar-age scales and an hour scale. Inside, the disc shows parallels of declination, two hour scales and a further scale for Babylonian or Italian hours. There is a slot through which the latitude arc can move and a hinged brass rod gnomon.

On the inside of the base is a rotatable compass that has a brass indicator to mark the magnetic variation on the degree scale. Either side of the compass are screw holes for the attachment of the latitude arc. There is a radial table of latitudes for places in Europe, organised into countries. Attached to the hinge of the base is a rule, which has two scales on each side. The compendium has a square, brown leather case with a false bottom, underneath which the latitude arc, Rojas projection index and brass rod are stored; it is probably later than the compendium.

The map of central Europe is a common feature of Schissler compendia. The latitude table includes some unexpected towns in Britain, such as St David's, Winchester and Hereford. On the base rim of the equinoctial dial, it is signed 'CHRI:S:S:1592'.

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