The characteristics of the NACA M-12 airfoil section
This is a 1926 NASA technical report plate of wind tunnel test data for the NACA M-12 airfoil section, catalogued by the NASA Technical Reports Server. The single picture is a hand-drawn graph on squared grid paper, with a small airfoil profile drawing in the upper right and several curves plotted against axes. A designer could take from it the clean, instrument-style chart layout, with thin ink curves, labelled axes and a tabular data grid.
