Aeronautic Instruments. Section III : Aircraft Speed Instruments
A 1923 technical report from the National Advisory Committee for Aeronautics, issued by NASA's Technical Reports Server, documenting aircraft speed instruments for engineers and aviation researchers. Its pages show line-engraved and photographic plates of air-speed indicators, from liquid-type gauges and pitot tubes to clockwork recording devices. A designer could take the precise, diagrammatic style of the early instrument photographs, with their dark metal tones, graduated scales and clean technical layouts.
