- (n.) 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.
- (n.) An instrument for the photographic recording of star transits.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). photochronograph. Retrieved September 20, 2026, from http://smartdefine.org/photochronograph/definitions/2044944 |
| Chicago | Webster's. 2011. "photochronograph" http://smartdefine.org/photochronograph/definitions/2044944 (accessed September 20, 2026). |
| Harvard | Webster's 2011, photochronograph, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/photochronograph/definitions/2044944>. |
| MLA | Webster's. "photochronograph" 27 May 2011. Web. 20 September 2026. <http://smartdefine.org/photochronograph/definitions/2044944> |