The technical innovations of the nineteenth century altered and expanded the perimeters of human vision in art and science. As early as 1834, Sir Charles Wheatstone observed that an object painted on a revolving disc appeared to be stationary when illuminated by an intense burst of electric light. He also noticed that flying insects seemed to be fixed in mid-air by the same means. In 1851, Henry Fox Talbot attached a page of the London Times to a swiftly revolving wheel in a darkened room, uncapped the lens of his camera, and made an exposure of about 1/100,000 of a second by means of an electric spark, sharply freezing the action of the moving paper. Talbot concluded that pictures of moving objects could be made by illuminating them with a sudden electric flash, providing a prototype for making stop action images by means of electronic flash.1 By the 1860s, as we have learned, photographers were making instantaneous stereoscopic views that arrested the action of people walking on the street. In 1887 Ernst Mach, an Austrian scientist, used an electric spark as a lighting source to make postage-sized, stop action images of projectiles moving at about 765 miles per hour. By the mid-1890s, spark exposures of one-millionth of a second were being made by scientists such as Lord Rayleigh and Théodore Lullin (who

photographed dripping tap water) and A. M. Worthington (who photographed splashing milk long before Harold Edgerton), providing the first images of previously unseeable occurrences. What these photographs depicted was often startlingly different from earlier visual depictions, making it obvious that human vision proved unreliable for detecting events that unfolded in fractions of a second. New methods developed that affected the look and content of photographs and further altered society’s sense of how time and space could be visually represented.