The most successful results, which were little better than silhouettes, were obtained when twenty-four cameras, set about one foot apart, were used. The photographs actually were not made at equal intervals of time but of space. The cameras and background were lined up for a measurement of distance and not of time. Although Isaacs contributed engineering skill to the development of the apparatus, because he was chiefly interested in railroad engineering and this assignment in his photographic hobby was a favor for the “big boss,” Muybridge alone obtained the patents on the method. On June 27 and July 11, 1878 he applied for a patent on, “A method and apparatus for photographing objects in motion” (the battery system), and for the double action shutter controls. The patents were issued in March, 1879. Wet collodion plates were used in each camera and a speed of up to 1/5000th of a second was claimed by Muybridge in his applications. Isaacs later became chief engineer of the Southern Pacific Railroad System while Muybridge made “scientific” photography a profession. [Illustration: The Horse in Motion, 1882 _CAMERA SYSTEM developed by John D. Isaacs, engineer, and Eadweard Muybridge, photographer, which made pictures at equal intervals of space rather than of time. It settled a wager on the nature of the movements of a horse._] During later life Muybridge sought to establish himself as a scientist and in this effort he drew heavily on physiological data which originated with Marey in France. Muybridge was a photographer, who, through the resources of Stanford, a rich and determined backer, came into possession of a method of taking successive pictures of action. Even though the method was cumbersome and inexact, Muybridge never changed it but continued to exploit it for the rest of his life. [Illustration: La Nature. 1882 _PHYSIOLOGICAL PARK. Paris, above, the first motion picture studio. Marey installed the camera in a box on rails. Below, Marey’s photo gun, first portable camera for photographing motion._] Marey, in France, was delighted to hear of the results of Muybridge’s work and to inspect them, for here at last was excellent confirmation of his physiological theories. Marey, while praising the work of Muybridge, noted certain errors resulting from the battery camera system--the landscape and not the animal appeared to be moving when the resulting photographs were analyzed in the Plateau magic disk and also the time interval, as noted above, was not exact.