Windmills in the light of modern research
This is a 1928 technical report from the NASA Technical Reports Server, a scientific paper on windmill aerodynamics issued for engineers and researchers. Its two pictures are a vector diagram of blade velocities labelled with angles and points, a small schematic of a windmill with a rotation arrow, and a line graph of lift and drag coefficients plotted against an angle axis, with solid and dashed curves. A designer might take the clean monochrome line-diagram style and the plain labelled technical notation as reference for schematic or infographic work.
