Self-luminous materials
This is a technical report on self-luminous materials, issued by NASA Technical Reports Server with a 1920 date, and the record gives no further detail on its makers or readership. The pictures are plain graph-paper line charts of brightness in microlamberts plotted against time in days for radium and polonium luminous tubes, and a decaying alpha-radiation curve. A designer might take from them a clean, sparse scientific chart style with labelled axes, tick marks and single hand-drawn decay curves.
