photochronograph

Century Dictionary and Cyclopedia

1. n. An instrument for taking photochronographic pictures. See photochronography.
2. n. A picture taken by this method.
3. n. An instrument for the observation of star-transits by photography.
4. n. A chronograph in which the tracing or record is made by the action of a pencil of light on a sensitized surface.

GNU Webster's 1913

1. n. (Physics) An instrument for recording minute intervals of time. The record is made by the power of a magnetic field, due to an electric signaling current, to turn the plane of polarization of light. A flash, coinciding in time and duration with the signal, is thus produced and is photographed on a moving plate.
2. n. (Astron.) An instrument for the photographic recording of star transits.