This undated notebook was used by Edison and an unidentified author, possibly in 1900; however, it may have been used as early as 1895. The book is primarily a record of observations concerning maintenance and repairs needed at the Ogden plant. The headings of individual pages are in Edison's hand. The book contains 105 numbered pages, followed by one unnumbered page with an entry on the #9 Elevator. Pages 96-97 are blank. At the beginning of the book is an index to all but the last entry.