A wooden box comprising a deep base and lid. The lid contains both horizontal and vertical bars of wood surfaced with green material (probably. felt). Two brass hinges, each with six screws, hold the lid to the base. The case has a brass hook fastener, a brass keyhole, and a curved brass handle. The interior base contains a triangular cover on which is inscribed, Troughton and Simms, LONDON. A metal container for holding mercury is wedged under a metal bar, and a wooden partition at the front of the box contains a heavy metal trough with three legs.