Astronomical compendium dial for latitudes 39°-54° North. This compendium consists of a lid hinged to a base with a set of three separate horizontal dial-plates. On the outside of the lid is a table of latitudes consisting mainly of places in Southern Europe. This table is continued on the inside of the lid. A compass, offset 11° East to allow for magnetic variation, is set into the main body of the compendium, which can be used for each of the three horizontal dial-plates. All three are engraved on both sides with hour scales and have a hole through which the gnomon can pass. Each is made for a different latitude and bears a separate coat of arms. On the back of the compass plate is a spring-loaded mechanism for the string gnomon.

On the inside of the base is a horizontal dial and a map of Europe laid out according to polar co-ordinates. The map can be used in conjunction with the horizontal dial. The shadow of the string gnomon indicates on the map those places where it is midday when the instrument is used on the longitude of Augsburg. Zero longitude is marked just East of Libya, but the exact position is not easy to gauge since the map is not accurately drawn. Stamped around the sides of the instrument is the signature, 'CHRISTOPHORVS SCHISSLER FACIEBAT AVGVSTA VINDELICORVM ANNO. 15. 75.'.

This dial was clearly made for an aristocratic patron, perhaps a pope, since one of the coats of arms carries the papal crown and the crossed keys of St Peter.

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