Recent progress in the theory of air flow as applied to aeronautics
This is a 1922 NASA Technical Reports Server scan of a technical report on the theory of airflow for aeronautics, written for engineers and aerodynamicists. The pictures are plain line diagrams of streamlines around a wing section, a circular cylinder, and a flat plate, with a lift-coefficient graph and a pressure-distribution plot. A designer could take from them the clean, schematic way flow lines bend around a form, showing how technical diagrams convey motion through evenly spaced curved strokes.
