Properties of Special Types of Radiators
A 1921 NASA technical report, a set of engineering test charts from the NASA Technical Reports Server, plotting drag and energy dissipation against air flow and yaw angle for special radiator types. Its pictures are plain black-and-white graph sheets with gridded axes, labelled curves and boxed specimen data, so a designer might borrow their clean line-chart structure, grid rhythm and the restrained use of small serif labels.
