NEW YORK CITY — “The subjects came from all walks of life: laborers, professors, art school models, university athletes, patients of Philadelphia neurologist Francis Dercum and even Muybridge himself.” Eadweard Muybridge’s “Human Locomotion” is early photography’s great compendium of human and animal movement. It also represents an early form of cinema achieved by photographing subjects with multiple cameras around them.  In a sale to benefit the acquisition fund of the Denver Art Museum, Sotheby’s offers 70 lots of photographs by Eadweard Muybridge in an online auction on now through April 10. For more information, www.sothebys.com.