Dimensions of twin seaplane floats
This is an NACA technical memorandum from 1933, issued by the National Advisory Committee for Aeronautics, presenting graphical charts of logarithmic relationships for engineers and researchers. Its three pages each show a family of straight lines plotted against log K and n axes, labelled with figure numbers and letter points. A designer could take from them the clean, sparse look of early engineering line graphs: thin black rules crossing at shared points, minimal lettering, and plain axis scales.
