Interference of multiplane wings having elliptical lift distribution
A NASA technical report from 1924 on the interference of multiplane wings with elliptical lift distribution, issued for aeronautical engineers and researchers. The single picture is a hand-drawn graph of a curve D(ε) falling from a high value near zero to cross the horizontal axis near 0.8 on a normalised ε/ℓ scale, marked by an upward arrow on the vertical axis, a clear example of early engineering plotting a designer could borrow for minimal line charts with labelled axes.
