Enlarged stereoscopic lunar photograph taken by Robert Howlett from the original negative by Warren De La Rue, published by Smith, Beck and Beck of London. Charles Wheatstone demonstrated his stereoscope to the Royal Society in 1838 in order to create an apparently three-dimensional image to demonstrate binocular vision. Although Wheatstone's invention was intended to be an experimental demonstration apparatus, stereoscopes became popular scientific toys, and were a feature in many households in the late 19th century. A card such as this would be placed in the viewer, and when one eye viewed each image, the picture would appear to be three-dimensional.
© National Museum of Science & Media / Science & Society Picture Library