Chronophotography is defined as "a set of photographs of a moving object, taken for the purpose of recording and exhibiting successive phases of motion.
At the time, Marey was working on the cinematographic, which was a camera that was shaped like a rifle and took pictures of moving objects from a rotating plate.
Using an electromagnetic shutter, two side-by-side films were exposed and wound around drums inside the camera built from wooden frames.
As a result of his death, Bull became head of the Marey Institute, which formed part of the Collège de France.
After a few years, Bull eventually introduced a few papers on a wide variety of subjects ranging from spark illuminations, high-speed motion-picture photography, original studies of insect and bird flight, and electrocardiography and muscle and heart functions.
He was awarded gold medals for his roles in developing the field of chronophotography by the National Office of Research and Invention (1933).
He continued his research well in to the 1950s, still publishing papers on high-speed cinematography and had a profound influence on many branches of engineering and science.
Described by a close friend Bull was this ‘tiny, bird-like, lovable figure, with an irrepressible sense of humour, and an ability to bring pleasure to those around him’.
A copy of his stereoscopic spark drum camera is held in the National Science and Media Museum of Bradford, England.