The influence of varying reactance upon the short circuit phenomena in alternators
A 1913 electrical engineering thesis by Everett Samuel Lee and Fred Peter Wittich, submitted at the University of Illinois and read by faculty examiners testing alternator behavior. The plates are photographic oscillograph records mounted on dark ground: pale sine-wave traces with sharp initial transient spikes, ruled baselines, and handwritten ink captions giving voltage, amperage, and phase angle, useful as high-contrast waveform marks and hand-lettered data labels.
