Hunters Patent US35,156, May 6th 1862
An American patent in 1862 by American instrument maker, H W Hunter, defines refinement in reading and using a compass. Whilst the compass rose design is in some ways similar to Singers, Hunter also addresses issues to do with the physical construction of a pocket compass. His patent addresses both the compass card design and means of locking the reading once the card is stable – a transit lock.
[1] US Patent Nos 35156, 6th May 1862.