During the latter 1800s. Henry Ward, founder of a company that sold scientific supplies, offered a series of plaster casts of fossil specimens that made the rounds at various World’s Fairs, expositions and so forth, with copies sold to numerous museums around the world. Some of these original casts can still be found in various instututions. Among Ward’s most popular attractions was his skeleton of Megatherium cuvieri, a giant ground sloth discovered in Argentina, who became the subject for numerous stereographs (just “reverse cross” your eyes to see them in 3D). The three above views show the skeleton as mounted at the Smithsonian Institution during the 1870s.
Below, stereographs from the Cast Room, Williston Hall, Mount Holyoke Seminary, South Hadley, MA (2, ca. 1881); the 21st Indian State Fair and Exposition, Indianapolis, fall, 1873 (2, the first with Professor Franklin C. Hill); the Centennial Photographic International Exhibition, 1876; Amherst College, Amherst, MA (ca. 1880; and Historical Rooms, Buffalo, NY (1870s).