Above, "Dixon crossing Niagara below the Great Cantilever Bridge," U.S.A., 1895-1903. And you can make your own, with Stereogranimator, a new project from NYPL Labs. Stereogranimator is " a tool for transforming historical stereographs from The New York Public Library's vast collections into shareable 3D web formats."

(thanks, Mikael Jorgensen!)