This notebook was begun in January 1890. All entries are by Edison. The book contains notes, drawings, and calculations relating to ore milling, including cost estimates based upon labor and energy requirements for separating iron, copper, and nickel ores from the Sudbury mining region. There are also notes regarding the testing of numerous chemical compounds for potential use in incandescent lamp filaments or phonograph cylinders. Edison's notations indicate that he assigned many of these chemical tests to an experimenter named "Joe," possibly John Joseph Force. The front cover is labeled "584." The inside front cover is inscribed "584 T. A. Edison Jan 4. 90." The pages are unnumbered, and at least one page has been removed from the back of the book. Approximately 130 pages have been used. Courtesy of Thomas Edison National Historical Park.