This folder contains correspondence and other documents, including notes, drawings, patents, patent assignments, affidavits, and agreements. The selected items cover the period 1909-1915. Most of the correspondence is between Frank L. Dyer of the Legal Department and patent holders John H. Powrie and Florence M. Warner. There are also letters to and from Edison, along with other items bearing his marginalia. The documents deal mainly with Powrie's heliochromic screens and related photographic processes, including an automatic film-developing apparatus. Many letters relate to his experiments in Paris and to tests of his film samples by Edison's staff. One letter in Edison's hand concerns Powrie's use of the Galvanometer Room at the West Orange laboratory; others pertain to the commercial value of Powrie's dry plates and his relations with the Pathé Frères and Lumière companies. Also included are letters regarding the cost and discontinuance of Powrie's experimental work at West Orange.
Some of the correspondence concerns Willard C. Greene, a photographic experimenter in the West Orange laboratory who considered Warner-Powrie film impractical for Edison's kinetoscope; Charles Brasseur, another inventor working on color photography; and Montgomery Waddell, a former assistant to Edison. Other items relate to the products of the Lumière Co., including autochrome and panchromatic plates, and to consultations with Pathé Frères, including a letter by engineer Charles Bardy regarding emulsification machines. There is also correspondence referring to the possible construction of a new film plant, as well as a letter of introduction for William C. Anderson of Detroit, a manufacturer of electric vehicles.
Approximately 60 percent of the documents have been selected. The unselected items include U.S. Patent 802,407, "Heliochromic Plate and the Process of Making the Same," issued to Powrie on October 24, 1905.