During the Civil War the Langenheims took nearly 1,000 pictures which were mounted for showing in the projection magic lanterns, and during the Franco-Prussian War in 1870–71 several hundred photographs and drawings were released by the Langenheim brothers for lantern use. The last catalogue of the firm was published in 1874 and included some 6,000 colored slides priced at $33 a dozen, and those specially photographed and made at $4 each. William Langenheim died on May 4, 1874. Frederic tried to continue the business for a time but he, too, was getting old and eventually sold out in the Autumn to Caspar W. Briggs, another early Philadelphia photographer. At the Philadelphia exhibit Frederic had a showing of the Voigtlander lenses made in Vienna which were the best then available for certain types of photographic work. Another Philadelphian, Henry Renno Heyl (1842–1919), a friend and associate of Sellers on the Board of Trustees of the Franklin Institute, was the first person in America to develop a projector which used “posed” motion photographs. The individual pictures were taken by the same method used by Sellers for his Kinematoscope. [Illustration: American Museum of Photography _LANGENHEIM BROTHERS, William (seated) and Frederic, pioneer Philadelphia photographers, who developed, in 1850, picture projection using glass slides._] Somewhat earlier, O. B. Brown, of Malden, Mass. obtained U. S. patent No. 93,594, dated August 10, 1869, on what is the first American “motion picture” projector. It, however, used only drawn designs and not photographs. In principle it was based, as other projectors of the time, on the system developed by Uchatius. In Brown’s projector the Plateau magic disk with the figures was mounted between the light source and the projection lens and was rotated by a gear arrangement. In front of the lens there was a rotating shutter with two holes which interrupted the light when the pictures were in intermittent motion. [Illustration: Maurice Bessy Collection _ETIENNE JULES MAREY, French physiologist, whose research on the movement of men and animals contributed to progress in photography of motion, 1870 to 1890._] Heyl perhaps may have obtained his basic idea from Brown or it may have come to him independently because the urge to combine the new photos and the older magic lantern was felt by many persons. At any rate, the Heyl apparatus bears very little relation to Brown’s. There is no evidence that Heyl attempted to patent his device, so the Patent Office never was called upon to decide the point.