Gliding in convection currents
A 1935 technical report on gliding in convection currents, issued by NASA's Technical Reports Server and drawn from early aeronautical research for glider pilots and meteorologists. The pictures are plain line diagrams: a dark-and-white map of terrain, paired vertical profile charts plotting altitude against temperature, and schematic cross-sections of slopes beside cumulus clouds. A designer could draw on their clean, schematic diagram style, with hatched shading and simple cloud outlines.
