Chart Table Marine Barometer by Callaghan No 4022 C1875

An attractive scarce chart table or bulkhead mounting marine aneroid barometer by Callaghan No 4022, c1875 * * * * * * Marine barometer having 4¼” silvered and die struck open scale dial, standard meteorological terms, the barometric scale with a range from 28 - 31 inches of mercury, divided down to 1/100ths". The upper part signed by the maker "Callaghan," with address "23a New Bond St, corner of Conduit St, London" below. Blued steel pointer, Callaghan pierced brass index. Heavy bevelled glass. Ist quality movement driven from a single 2¾” capsule tensioned on a coil spring, the cock dated "17/3/87" and stamped with serial no. "4022," all raised over a circular, cast steel chassis. Brass sub-chassis with pivoted spindle and gain adjustment. All contained within a brass drum form case, the verso with three radially mounted fixing plates, calibration port. Condition: The subject of a full service, conservation, and calibration under laboratory conditions, the movement working well, see performance chart. The case originally would have been oxidised brass, ie a glossy slate grey finish - this has, over the years, been largely polished away, the verso finish remaining mostly intact. The dial with some minor marks, the deeply bevelled glass remaining essentially damage free. Comments: This is a top quality instrument, certainly as good as or better produced than other similar instruments. These were intended principally for mariners, the advantages over a gimballed mercurial barometer only too clear. Particularly favoured on racing yachts for their ease of stowage and rugged construction. William Callaghan was one of the few retailers that actually did make the instruments - many names that appear on the dials are simply the retailers. The quality of these early Callaghan instruments is only too evident, this maker being perhaps the most collected of all. Rare, aesthetically attractive, and top quality, a piece for the collector and connoisseur alike. Dimensions exclude bulkhead fixings.