Altimeter, Sensitive, Type C-12, 50,000 ft, US Army Air Force WWII B-47 the angled line to the

the angled line to the semi-circle lands at the second "0"

the Zero Reader can be compared to an auto pilot in which the human pilot replaces the servos

Here is a post-WWII-era Sensitive Altimeter

among others

Altimeter, Sensitive, Type C-12, 50,000 ft, US Army Air Force WWII B-47 the angled line to theHere is a WWII era Sensitive Altimeter, Air Corps US Army Type C 12, made by Kollsman. The C 12 Altimeter was used across all aircraft of the Air Corps US Army, including heavy bombers B 17 and B 24, medium bombers, B 25 and B 26, Fighters P 38, P 39, P 40, P 47, and P 51, and transports C 46 and C 47, according to the Maintenance Interchangeability Chart dated Dec 1943. The C 12 Sensitive Altimeter displayed altitude using 3 pointers. The first and