A Stereoviewer made by Underwood & Underwood of New York. The viewer has two lenses at a set distance in an aluminum frame. The frame is marked 'Sun Sculpture U&U trade mark'. Its frame is bordered with golden brown felt. The pictures can be moved horizontally in order to focus them. The stereoscope can be held with a folding handle. Near the handle the stereoscope is marked 'Man'f'd by Underwood & underwood New York Patented June11 1901 Foreign Patents Applied For' This is a Holmes type stereoscope, named after its inventor, Oliver Wendell Holmes (1860). These devices first became popular in the middle of the 19th century.