This is described as “The Pony Mathematician” (10780). Comparing old photos, it’s not Hans Clever, but this image is from around the same time. Maybe it’s at the Chicago’s World’s Fair? Nevertheless, it’s very rare and obviously cool. Benjamin is well known for his photojournalism, stereoview publishing company, the invention of a photo gun camera, as well as search and rescue work on Mount Washington. This is a stereoview (also known as a stereograph or stereoscope card). It is one of the first forms of 3D photography. The images were captured with a special stereoscopic camera, which has two lenses – simulating the view of our left and right eyes. The two, nearly identical pictures are then mounted next to each other (most commonly on a piece of cardstock, glued on as photographs or printed as lithographs). The image can then be seen in three dimensions when viewed through a device known as a stereoscope, stereopticon, and/or televiewer. Standard-size stereograph, measuring about 3.5 x 7 inches. All of my paper items are protected in archival-safe polypropylene sleeves and packaged in rig.
