The effect of bow stiffeners in nonrigid airships
This is a 1923 NACA-era technical report from NASA's Technical Reports Server on how bow stiffeners affect the stresses in nonrigid airship envelopes. The pictures are plain engineering line graphs with gridded axes and labelled solid and dashed curves comparing stress and pressure against distance from the nose and radius. A designer could take from them only a sense of the period's scientific chart style: thin black curves, tick-marked grids and handwritten-style labels.
