Theory of wing sections of arbitrary shape
This is a 1933 National Advisory Committee for Aeronautics technical report by Theodorsen, issued in the United States, for aeronautical engineers and researchers working on wing theory. Its pictures are plain line diagrams of a unit circle mapped onto an airfoil profile, with construction lines, Greek-letter labels and a graph of upper and lower surface curves; a designer might take from them the clean geometry of mapping one closed curve onto another, drawn in restrained technical linework.
