Considerations affecting the additional weight required in mass balance of ailerons
This is a 1937 NASA technical report on aircraft aileron mass balancing, issued by the National Advisory Committee for Aeronautics for aeronautical engineers and designers. Its single picture is a log-log chart plotting mass-balance coefficient against the e.g. of aileron, with a family of diagonal lines for aileron span ratios and a legend giving the ratio of inner to outer span. A designer could take from it the visual language of engineering nomograms: a dense grid of fine rules, labelled diagonal curves and tidy axis ticks.
