Savage western view. 
Photographic Auction Stereoviews
Used extensivly in Europe and Introduced at the 1851 Crystal Palace exhibition, a special viewer to view two images approx 21/2 inches apart allow the viewer to see a 3D picture. In 1858 the Langenheim brothers introduced the American Stereoscopic Views which began the stereoview movement in America lasting until the 1920's with the Keystone view series of WW1. All of the major photography studios of the era created their own stereoviews and sold them either indivualy or in sets.