Experiments with a wing from which the boundary layer is removed by suction
A 1931 NASA technical report on experiments with a wing whose boundary layer is removed by suction, written for aeronautical researchers and engineers. The pictures are plain engineering drawings: a dimensioned airfoil profile with chord marks, a set of seven airfoil section sketches labelled I to IV with radii and dimensions, and a line graph of maximum lift coefficient against suction quantity with hand-lettered curves, grid lines and a caption. A designer might take from them the clean, monochrome diagram style of early aerodynamic drafting and its labelled dimension lines.
