Pilots' Airplane Manual CAA Bulletin 27 1940 DC-7 it measures change in barometric

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

transport C-130 Hercules

Here are two types of aircraft Pelorus Drift Sight

75 inches high and 5

Here is an engine Torque Pressure Indicator

Pilots' Airplane Manual CAA Bulletin 27 1940 DC-7 it measures change in barometricThis is an original general aviation Pilots' Airplane Manual published by the Civil Aeronautics Administration in September 1940 as Bulletin No. 27. The focus on this manual is the structure, maintenance, and rigging of aircraft. This 150 page, 8. 5 x 11 inch manual is in reasonable condition given its age. There are a few minor tears, but the pages appear to be intact.