A rectangular black-lacquered steel trough with four levelling screws and a black-lacquered brass-framed roof-shaped cover. Two sides of the cover have clear glass panels, at an angle of 90 degrees. Accompanying the instrument is a full, circular wooden jar for storing the mercury when the instrument is not in use. The threaded stopper for the jar is missing. There is also a spirit level, however, a second level is missing.

The artificial horizon is contained in a fitted carrying box, marked on the lid ‘HO [broad arrow] 21’ and containing a trade label for Cary and Co (Henry Porter), 7 Pall Mall London.

The broad arrow and initials ‘HO’ indicate that the instrument belonged to Hydrographic Office of the Royal Navy.