Chronophotography is a photographic technique from the Victorian era which captures a number of phases of movements. The best known chronophotography works were mostly intended for the scientific study of locomotion, to discover practical information for animal handlers and/or as reference material for artists. Although many results were not intended to be exhibited as moving pictures, there is much overlap with the more or less simultaneous quest to register and exhibit photographic motion pictures. Chronophotography is defined as "a set of photographs of a moving object, taken for the purpose of recording and exhibiting successive phases of motion". The term chronophotography was coined by French physiologist Étienne-Jules Marey to describe photographs of movement from which measurements could be taken and motion could be studied. It is derived from the Greek word χρόνος chrónos ("time") combined with photography. Soon after the introduction of photography in 1839, the camera became the dominant source of accurate depiction of life. As the technology became more sophisticated, so did the activities for which people used cameras. Around 1840/1841 Francis Ronalds documented his first idea to use photographic methods to make scientific recordings. His first machine was built in April 1845 to continuously trace the varying indications of meteorological equipment on photographic paper. The cameras were supplied to numerous observatories around the world and some remained in use until well into the 20th century. The earliest Daguerreotype photographers already took multiple shots of a subject, mostly to increase their chances of obtaining a successful picture. Making multiple shots of one subject was also a sensible solution when multiple pictures were wanted, since Daguerreotypes could not be reproduced (except by photographing an existing Daguerreotype). At least from the early 1840s some photographers used multiple cameras, resulting in series of pictures with small differences in time and/or angle.