Static stability of seaplane floats and hulls
A 1924 NASA technical report on seaplane float and hull stability, presenting engineering data for aircraft design. Its two pictures are scatter-plot graphs with a fitted straight trend line, plotting metacentric height in feet against gross seaplane weight in pounds for twin and single float seaplanes; a designer might take from them the clean, minimal chart styling of plotted data points, labelled axes and a diagonal regression line.
