Propeller tests on airplanes
A 1922 NASA Technical Reports Server item on propeller tests for airplanes, a technical report of engineering measurements rather than a general book, with its figures presented as line-drawn graphs. The pictures are plain plotted charts: one shows curved performance lines with labelled values and small circle and cross markers, and the other shows a scattered-point efficiency graph with a fitted straight line against a ratio axis, offering a designer little beyond the clean diagrammatic style of early engineering plots.
