This folder contains correspondence relating to ore mining and milling operations at Bechtelsville, Pennsylvania, and Ogden, New Jersey. Most of the letters are to and from Edison and Harry M. Livor, general manager. The letters deal mainly with equipment, ore analyses, and mining properties. Some items concern the steam plant, separator, and crushing rolls. A few items pertain to the purchase of an expansion engine from Weyher & Richemond of France. Approximately 50 percent of the documents have been selected. Courtesy of Thomas Edison National Historical Park.