An apparatus is described for making time-resolved spectrograms of single sparks or other short-time sources of light. Our adaptation of a conventional quartz spectrograph provides for sweeping the image of a selected region of the light source along the length of the slit by means of a rotating mirror. The time base can be made as short as 10 µsec. and time resolution of events in the source as brief as 0.5 µsec.
G. GORDON and W. M. CADY, "An Apparatus for Time-Resolved Spectroscopy," J. Opt. Soc. Am. 40, 852-853 (1950)