Experiments wit slotted wings
This is a 1921 technical report of experiments on slotted aircraft wings, issued by NASA's Technical Reports Server collection, aimed at aeronautical engineers. The pictures are mostly plotted graphs of lift and drag coefficients against angle of attack and pressure, with a few line diagrams of force vectors and wing sections. A designer could take from them the restrained chart style of engineering plates, with clean grids, labelled curves and sparse dotted and dashed linework.
