This undated notebook was used by Edison, probably in 1887 or 1888. The book contains drawings and occasional calculations relating to ore milling and electric lighting. In addition, there is a list of items for a phonograph caveat and another list, apparently of items to be made for the laboratory. Included on that list are phonogram cylinders, insulation, carbon buttons and chalk cylinders, meter solutions, kinetoscope materials, and condensers. The pages are unnumbered, and the book has been used in both directions. Approximately 100 pages have been used. Courtesy of Thomas Edison National Historical Park.