We are offering a late 1800s English 18K pocket aneroid compensated barometer and altimeter.  With barometric range from 23 to 31, meteorological headings "Rain", "Change", "Fair", and altimeter readings.  The see-through crystal reveals the inner workings.  Also marked "Compensated" on the lower edge.  Outer edge of case is marked 750 which is the English hallmark for 75% gold, the equivalent of 18 karat.  The back of the case is engraved with a shield in the center surrounded by a leaf and floral design.  The barometer is approximately 1" in diameter.  See images for details.