Propeller design IV : a simple method for determining the strength of propellers
A 1926 NASA technical report on propeller design, a plain engineering document with no named publisher or intended audience beyond aeronautical engineers. Its single picture is a technical diagram of airfoil cross-sections for single and double camber, with dimension lines, centre-of-gravity markers and labelled chords. A designer might take from it the clean line-drawing style of labelled cross-section diagrams.
