Equinoctial dial, outside of case

Universal equinoctial dial for latitudes 30-65 North. Round silver watch-type case containing the silver dial which has a brass hour-circle and gnomon. The front and back of the case are engraved with laurel wreaths, within which is contained a table of latitudes comprising cities and tables in Europe, such as 'Ierusale (Jerusalem) 32', 'Madrit 41' and 'Stockh (Stockholm) 60'. The dial-plate is silver and engraved with leaves and has a circular pattern around the compass. The latitude scale is engraved on a small circle and divided anticlockwise. There is a rotatable index arm attached to the centre of this circle, which is linked to a cam and spring mechanism for setting the angle of the hour circle. The compass, also silver is set into the dial-plate. The cardinal points are marked in Latin initials and the magnetic variation is marked at 15 West of North. The needle is blued, in the form of an arrow and surmounted by a brass pyramidal pivot. There is a broken glass plate over all. The hour-circle is spring-loaded, hinged and made of gilt-brass with silver inset in its inner rim. It is engraved with hours and numbered clockwise 3-12, 1-9. A pivoted, turned gilt-brass strut across the East-West diameter supports the rod gnomon, which has a weight at one end.
Johann Martin