SOLD Excellent example of scarce mapping compass with transparent glass bottom made for use by balloonists and early aircraft pilots around WW1 era. The compass is made by well known retailer and maker of scientific instruments E Vion Paris and has the initials AER MRE Aeronutique Militaire) on the back face. The compass is equipped with a nice compass needle, French cardinals points, hand locking sistem and an extra bracket to be attached on map schetching board or pilot coat. The compass is made of brass and glass. Dimensions: 55mm diameter and 15 mm height.
