Rate of Climb / Vertical Speed Indicator, Model 1, 100 M/M, Japanese Naval Aviation F4U Corsair According to our friends at

According to our friends at Wikipedia:

and adjusted by AeroAntique

BU AERO USNAVY is embossed on its face

but reveals another sealed metal plate

Rate of Climb / Vertical Speed Indicator, Model 1, 100 M/M, Japanese Naval Aviation F4U Corsair According to our friends atThis is a fine specimen of a Vertical Speed Rate of Climb Indicator, Model 1, as used in aircraft of the Japanese Navy during WWII. It measures rate of climb or descent in up to 100 meters minute. The calibration screw is on the rear of the instrument at the 3 o'clock position. Although the instrument is missing its data plate, it appears identical to the one illustrated in Robert Mikesh's book Japanese Aircraft Equipment 1940 1945, see photo, which