Universal equinoctial dial for latitudes 0°-80° South. This dial has a cast iron latticework base with a hinged dial-plate, and a latitude arc on the West side. The brass hour-circle segment is supported by iron spokes and is connected to the hinge by two further iron arcs, thus leaving space for a date wheel, which is used to adjust the hour scale for the equation of time. The hour-circle is pivoted at its centre and is adjusted for longitude. The gnomon is missing. The central supporting spoke extends below the hour-circle to act as a pointer on the equation of time scale at the hinge.

This instrument was made for use in the Southern Hemisphere only. It was created as a mean-time dial with the hour scale being adjusted by means of a date ring constructed to mark the changes in the equation of time. The fact that the 'XII' is offset by 30 minutes from the meridian line indicates that the dial was intended to show mean 'clock' time rather than mean solar time, for a place that was in the middle of a time zone. This would be consistent with various places in the western part of Queensland, Australia. The lack of a compass shows that the instrument was intended to be fixed in position. '1912 SYNCHRONOUS SUN-DIAL PATENTED JAS SINCLAIR QUEENSLAND' is stamped on a brass plate screwed to the support structure.

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