Compass, Aircraft Navigation, Armée de l'Air, Vion
This is the body of a Navigational Compass as used in aircraft of France, likely pre-WWII. Made by E.Vion. The compass body would be contained in a cradle, and affixed to a mounting bracket, which could be attached to either a vertical or horizontal surface of the aircraft. This compass is intended to be positioned and read at eye-level. The liquid is no longer contained in the body. The compass card floats freely.
We believe it may be the compass body for the Vion Type Q.S.C.V. 29, based upon the illustration in the photo gallery, which shows the compass body contained within its cradle and mounting bracket, along with an illuminating fixture in the front center.
The compass body measures ~5 inches diameter and ~3.5 inches deep.