Alterations and Tests of the "Farnboro" Engine Indicator
A 1930 aeronautical technical note from the Aeronautical Research Committee series, issued by a British government research body and catalogued through NASA's technical report server, presenting alterations and tests of an engine indicator for engineers. The pictures are plain line drawings and photographs: sectioned indicator mechanisms in cross-hatched cutaway, a schematic circuit diagram with labelled components, and a sideways photograph of an indicator installed on a test engine, offering a designer clean technical diagram conventions such as hatching and labelled callouts.
