Danger of ice formation on airplanes
A 1929 technical report from the NASA Technical Reports Server, a scientific paper on the danger of ice forming on aircraft in flight, with its figures printed as line graphs. The single picture is Fig. 1, a plot of supersaturation in grams of water per cubic metre of air against temperature in degrees, with a curve that bends back sharply near minus fourteen degrees. A designer could take from it only the look of a clean, unshaded scientific chart with open circle data points and a thin black curve.
