This American Optical industrial-strength lantern slide projector, was used in large auditoriums and traditional classroom settings.
American Optical was established in 1833 as a small spectacle manufacturing concern in Southbridge, MA. The company grew rapidly, gradually acquiring additional facilities for manufacturing a range of optical products. In 1935 this expansion lead to its purchasing the Spencer Lens Company of Buffalo, New York. For several years after the acquisition the Spencer Lens Company continued operation under its own name before becoming known as the Instrument Division of American Optical Company in 1945.