Contribution to the Problem of Airfoils Spanning a Free Jet
A 1936 NACA technical memorandum on wing sections spanning a circular free jet in wind tunnel tests, issued by the NASA Technical Reports Server collection for aeronautical engineers and researchers. Its pages show polar diagrams of drag against lift, efficiency curves, and lift coefficient plotted against angle of attack, all as plain black-line charts on ruled grid paper. A designer could take from them the clean, technical chart styling: thin curves, labelled axes, and sparse grid layouts.
