First Magic Lantern show in Philadelphia
In 1849, Frederick and William Langenheim, German-born brothers who became prominent commercial photographers in Philadelphia, gave their first public magic lantern show using photographic slides known as hyalotypes. This event was a culmination of their pioneering development and use of glass positives necessary for the projections. Through their work with glass technology combined with advances in light production, the brothers helped sharpen the images producible with the lantern and expand its usage to public lectures and other educational presentations.
“Langenheim Brothers.” The J. Paul Getty Museum. Accessed 24 November, 2015. http://www.getty.edu/art/collection/artists/1249/langenheim-brothers-frederick-and-william-langenheim-american/