Equinoctial sun dial

Equinoctial sundial, 1694. The outer case of this instrument bears the monogram of William and Mary. It was made by M. T. Hager of Arnstadt, Germany. The compass needle was set to North and the latitude was indicated on the circular dial using an index finger which is now missing. The gnomon or pointer would then spring into the correct position and the time could be read from its shadow.