Museum piece
The open brass case is supported by slender columns and topped with a wide overhanging roof. Beneath the glass dome, the dial, movement and torsion pendulum can be seen from every side. The gold-coloured dial has a sunburst texture and is framed by a light-coloured ring with black Arabic numerals. Deep red, originally lacquered brass elements add touches of colour.
The idea for the anniversary clock goes back to Johann Anton Harder. Together with the clockmaker Lorenz Jehlin, he applied for a patent for a design with a torsion pendulum. The German Imperial Patent No. 2437 was filed on 16 September 1877.
Inside is a mechanical anniversary clock movement with a torsion pendulum. The pendulum rotates slowly around its vertical axis; this energy-efficient design allows a long interval between windings.