Effect of temperature and pressure on the sparking voltage
This is a 1920 technical report from the NASA Technical Reports Server, a scientific paper on how temperature and pressure change the sparking voltage of gaps and terminals, written for engineers and physicists. Its pictures are plain black-and-white line graphs of sparking voltage against pressure in atmospheres and a kenotron circuit diagram, with a sparking-terminals cross-section. A designer might take from them the clean grid-and-line chart style and the schematic diagram conventions of early twentieth-century engineering.
