This notebook was probably begun by Edison on January 3, 1888. The first page contains the notation, "Idea Book." At the front of the book are notes and drawings for a caveat covering phonographs, electric lighting, ore milling, and batteries (April 29, 1889); an electric brake caveat (June 15, 1889); and an electric railroad caveat (April 10, 1890). Near the end of the book is a 5-page list of proposed inventions, followed by notes on phonograph caveats (April 14, 1888; November 10, 1888) and electric lighting experiments (April 14, 1888). The back cover is marked "Edison Private." The spine is labeled "47." The pages are unnumbered, and the book has been used in both directions. Approximately 130 pages have been used. Courtesy of Thomas Edison National Historical Park.