Climate and Weather for Flight in Naval Operational Zones, 1944, NAVAER 00-8OU-20 P-47 it measures change in barometric

it measures change in barometric pressure that is interpreted as altitude and recorded on a rotating chart drum

the nomenclature on its face ("Elevate" and "Depress") as well as the range on the degrees scale (10 to 0 to 65deg) doesn't seem to support that identification

and aircraft systems

published in 1945 by the aircraft engineering and manufacturing firm Grumman

Climate and Weather for Flight in Naval Operational Zones, 1944, NAVAER 00-8OU-20 P-47 it measures change in barometricThis WWII era authentic training manual was used to instruct US Navy aviation cadets who had completed courses in aerology and flight planning. The manual familiarized the cadet with the climate in all zones around the world in which the US Navy was operating, weather patterns, and what conditions they might encounter when conducting flight operations in each. This 200 page manual was published in 1944. 8 inches by 10. 5 inches. In good condition.