very clean Mexican stereoscope with its original holder + 3 Stereoscopic boxes Mexican stereoscopic viewer: viewer Stereoscopic wood, metal and glass, considered one of the simplest manual models of the market and widespread, especially in the United States at the beginning of the twentieth century. It is composed of two lenses (square prisms), nickel metal visor, folding handle and sliding crossbar to hold the views presented on photographic paper. Oliver Wendell Holmes in 1861 deliberately created and patented a portable viewer, simplified and much cheaper than had been available before. The stereoscope, dating from the 1850s, consisted of two prismatic lenses and a wooden stand to hold the stereo card. This type of stereoscope remained in production for a century and there are still companies that manufactured in limited production. It is mainly American, although often called"" Mexican stereoscope"" .