Maker and Role
J. H. Steward Limited, Manufacturer
Aero Hypsometer, Compensated 4678. The unit is shaped like a watch with a turning crown and a leather strap. The strap passes through the lug holders between the lugs and is continuous. The unit is fitted with an acrylic crystal and a silvered dial. The dial is calibrated from 0 ~ 10000 feet. When the crown is turned in the clockwise direction, the perimeter of the dial moves anti-clockwise. When the crown is turned anti-clockwise, the dial moves in the clockwise direction. There is a long blued hand on the dial which reaches to the very end of the dial perimeter. The bezel is revolving which then moves the red arrow across the face of the unit in both directions.
Signature/Marks and Type
J.H. Steward Ltd. 406 Strand & 457 West Strand London
Aero Hypsometer Compensated 4678 Printed
J. H. Steward Limited. Hypsometer - Aero, 1981.406. The Museum of Transport and Technology (MOTAT).