The effect of electrode temperature on the sparking voltage of short spark gaps
This is a 1924 technical report from the NASA Technical Reports Server, a scientific paper on how electrode temperature changes the sparking voltage across short spark gaps, written for physicists and electrical engineers. Its three pictures are plain graphs of voltage against gap conditions, with curves labelled by roman numerals, and a line diagram of a hot-electrode apparatus with a heating circuit, mica shield and air inlet, all drawn in sober black line with no decoration, so a designer might take only their clean measured-chart and lab-schematic look.
