Effect of Compression Ratio, Pressure, Temperature, and Humidity on Power
This is a 1919 NASA technical report, issued by the National Advisory Committee for Aeronautics, on how compression ratio, air pressure, temperature and humidity affect aero engine power. Its pictures are engineering graphs: multi-panel plots with grid lines, labelled curves and boxed notes, plus a correction chart and a horsepower ratio chart with families of sloping lines. A designer might borrow the clean grid-and-curve layout, the restrained two-tone plotting, and the tabular annotation style of early technical documentation.
