Multimedia publisher. Founded in 1919 by Harley L. Clarke a utilities magnate and Forest Ray Molton, an anatomy professor at the University of Chicago, in the form of a medieval guild. The aim to produce films for use in schools. Within three years the company was failing. Clarke sold the company to Marie Witham who continued the business on a smaller scale. In 1923 she introduced the Picturol range. Maintains largest slide film library