Plates 294 to 299 of Eadweard Muybridge's groundbreaking collection from 1887 titled Animal Locomotion: an Electro-Photographic Investigation of Connective Phases of Animal Movements, a massive portfolio with 781 plates comprising of 20,000 photographs. In the preceding four years Muybridge made more than 100,000 images, working obsessively in Philadelphia under the auspices of the University of Pennsylvania. The vast majority of Muybridge's work at this time was done in a special sunlit outdoor studio, due to the bulky cameras and slow photographic emulsion speeds then available. One of his favoured subjects to show the human form in locomotion was the tennis player. (Wikipedia). Learn more about Muybridge's pioneering research into human and animal locomotion, and see the wonderful photographs, in Taschen's epic 2014 tome Muybridge: The Human and Animal Locomotion Photographs.