Considerations on propeller efficiency
A 1928 technical report on propeller efficiency, issued through the NASA Technical Reports Server and written for aeronautical engineers studying wing and propeller performance. Its pictures are plotted engineering charts: grids of curves with labelled axes for lift coefficient against drag coefficient, one with a propeller positioned above the wing trailing edge. A designer could take their clean, schematic line-graph style, with thin curves, dense gridlines and small italic labels, as a model for technical diagram layouts.
