The one dated entry in this notebook is from March 16, 1912. The book was used by Edison at his Fort Myers laboratory primarily for notes on battery and electrical system experiments. Much of the book consists of calculations, drawings, and electrical diagrams. There are also lists of projects on which Edison was working, including home and educational kinetoscopes and films, cylinder and disc phonographs, a speaking picture phonograph (kinetophone), dynamos and rectifiers for house lighting, Leland batteries, small wagon motors, Bates numbering machines, and cement phonograph cabinets. Inserted into the book is a note from Charles Edison to his father, dated July 2, 1928, regarding power house statistics and alternating versus direct current. The pages are unnumbered. Approximately 65 pages have been used. Courtesy of the Edison-Ford Winter Estates.