Friction of Aviation Engines
A 1928 NASA technical report on friction in aviation engines, issued as a set of engineering charts for engineers testing aircraft powerplants. The pictures are dense line graphs of friction mean effective pressure against barometric pressure, with separate families of lines for each engine speed in revolutions per minute and for jacket water outlet temperatures from 30 to 80 degrees Celsius. A designer could take from them the disciplined grid, tiered stacking of parallel lines, and sparse labelling typical of scientific data graphics.
