It used slightly anamorphic pictures traced from his photographs and painted onto glass discs, in an early type of rotoscoping. One disc had anamorphic chronophotographs of the skeleton of a horse posed in the different positions of a stride, as recorded in 1881. Muybridge continued his locomotion studies of different animals and of people until 1886. Many others would follow Muybridge's example and started making sequential photograph series, a method dubbed "Chronophotographie" by French scientist Étienne-Jules Marey. Marey had already been researching and graphically recording animal locomotion for years. His book "The animal machine, terrestrial and aerial locomotion" (French edition 1873, English edition 1874) had inspired Leland Stanford to look for a way to correctly visualize the strides of horses. In 1882, Étienne-Jules Marey started using his chronophotographic gun for scientific study of animal locomotion. It was capable of taking 12 consecutive frames a second. Prompted by the much publicized successes of Muybridge's photographic sequences and other chronophotographic achievements, inventors in the late 19th century began to realize that the making and showing of photographic 'moving pictures' of a more useful or even indefinite length was a practical possibility. Many people working in the field followed the international developments closely through information in periodicals, patent filings, personal contact with colleagues or by getting their hands on new equipment. Between 1886 and 1894 Ottomar Anschütz developed several versions of his "elektrische Schnellseher", or Electrotachyscope. His first machine had 24 chronophotographic 9x12 centimeter glass plate images on a rotating disk, illuminated from behind by synchronized stroboscopic flashes from a Geissler tube. In very successful presentations between 1887 to 1890, four to seven spectators at a time would watch the images on a 12.5 centimeter wide milk-glass screen in a window in a wall of a small darkened room. In 1890, Anschütz introduced a long cylindrical automated version with six small screens. In 1891, Siemens & Halske started manufacture of circa 152 copies of Anschütz' coin-operated peep-box Electrotachyscope-automat, that was successfully distributed internationally. On 25 November 1894, Anschütz introduced his patented projector with two intermittently rotating large disks and continuous light to project images on a 6 by 8 meter screen for 300-seat audiences.