Investigation of damping liquids for aircraft instruments
A 1929 NASA technical report on damping liquids for aircraft instruments, presenting laboratory test data for mixtures of oils, alcohols and solvents. The four pictures are engineering line graphs plotting viscosity coefficient against temperature in degrees Celsius for each mixture, with curves numbered and tabulated by percentage concentration, and a designer might take from them only the restrained, grid-based chart style with its numbered curves and small open-circle data markers.
