This item is a handheld metal and wood Holmes style stereoscope. The metal viewer has flower and leaf details engraved with fabric lining the metal eyepiece. This object was used to view two nearly identical images, or stereographs, as one three-dimensional photograph. The mercury stereoscope was manufactured by H.C. White Company, a main manufacturer of Holmes style stereoscopes. White obtained several patents for his high quality stereographs and stereoscopes. In 1907, White made the most mechanized stereo publishing facility in the world. The entire photo printing process was automatic to ensure a uniform standard. The H.C. White company produced three standard stereoscopes: wood, wood and metal, and all metal.