Altimeter, Mk XIIIB, 0-20,000ft, British Royal Air Force A-30 This case of this indicator

This case of this indicator is not affixed

It is very similar to I-65 compass indicators used in aircraft of the Air Corps US Army during WW2 (the primary difference in appearance being the centerpoint of direction

The dial measures 2

It is in reasonable condition given its age

not gallons

Altimeter, Mk XIIIB, 0-20,000ft, British Royal Air Force A-30 This case of this indicatorHere is a British Altimeter (Height Indicator) Mk XIIIB as used in pre WW2 aircraft as well as aircraft during WW2, with a maximum ceiling of 20,000ft. It has the original crown symbol of the Air Ministry on the back. The knob rotates the face of the instrument to correct the scale. According to the Royal Australian Air Force 346 Types and Locations of Instruments dated 1945, this indicator was used in the Avro Anson, Supermarine Seagull V, and Short