The testing of balloon fabrics
A 1920 technical report from the NASA Technical Reports Server on testing balloon fabrics, compiled for aeronautical engineers and materials researchers. The pictures are line graphs of permeability and acetone extract percentages plotted against time in days, along with a temperature chart of mean weekly readings from Washington and Pensacola from July 1917 to October 1918. A designer might take from them the plain grid-and-curve style of early scientific charts, with dashed and solid line variations and open and filled markers for comparing series.
