The Chronocyclegraph

The technique was developed by Frank Gilbreth and his wife, Lillian in the early 20th century to improve work methods. The couple employed time-lapse photography to reduce a complete work cycle to the shortest and most efficient sequence of gestures.

To look for this optimal "relationship of human effort to the volume of work that the effort accomplishes", they attached a camera to a timing device and photographed workers performing various tasks. The motion paths were traced by small lamps fastened to the worker's hands or fingers.

From image verso: "Left hand of drill press operator 'Positioning after transportation' (this study resulted in cutting the time in halves)." Machinist with light showing hand movements, circa 1915. Collection: Frank B. Gilbreth Motion Study Photographs (1913-1917). Repository: The Kheel Center for Labor-Management Documentation and Archives