Altimeter, Tycos Type C, 25,000FT, WWI Aviation Section Signal Corps US Army C-43 which cross references to those

which cross references to those used in RAF aircraft

Fighters P-38

The upright with the white vertical marking opposite the data label is positioned forward

The oil temperature was measured via capillary tube (not included) and the pressures were measured via bourdon tubes

Altimeter, Tycos Type C, 25,000FT, WWI Aviation Section Signal Corps US Army C-43 which cross references to thoseHere is a Type C Altimeter used in early military aircraft of the US Army Air Service during WWI. It is labeled as having been manufactured for the Aviation Section Signal Corps US Army, which was active from 1914 to 1918. Crudely measured altitude from 0 25,000 ft, which was pretty high for aircraft of that era and requiring supplemental oxygen for the crew to exceed ~12,500 ft based upon modern standards. The knob rotates the face of the dial while