Effect of the ground on an airplane flying close to it
This is a 1932 NASA technical report on aerodynamics, examining how the ground affects an aircraft flying low over it; the record gives no further publisher or audience. The single picture is a scatter plot with two fitted curves, plotting a measured quantity against a scaled axis, with circle, cross and plus markers for different data series. A designer could take from it the clean, minimal style of technical charts, with dotted data points, thin curves and simple axis labels.
