Tension experiments on diaphragm metals
A 1927 NACA technical note on tension and creep tests of diaphragm metals, issued by the National Advisory Committee for Aeronautics for engineers and aircraft designers. Its pictures are plain line graphs of measured drift in millimetres against time in hours, with numbered curves for each specimen and stress level, drawn in black ink on white paper. A designer might take from them a restrained scientific chart style: fine gridlines, numbered curve labels, and rising sigmoid lines that suit technical or data-driven layouts.
