Entrance to Holyrood Chapel

This is an example of a stereograph—cards with two nearly identical images placed side by side that produce a three-dimensional effect when viewed through a handheld stereoscope. To create stereographs, photographers would take images of the same scene from two slightly different perspectives, the same distance with which human eyes are separated, thus approximating binocular vision. Stereographs came into European and American marketplaces in the mid-1850s and were very popular soon after. Their affordability helped to popularize photography by bringing it into the hands of the middle class. Picturesque topographical views, such as the ruins of ancient monuments and abbeys, were quite common.