This undated notebook was used by Edison, possibly in 1889. It contains drawings of lamps and filaments, calculations of costs for ore milling, drawings of ore separators, and lists of compounds derived from a multi-volume work on chemistry. There are also various other drawings and calculations. Although part of the N-series, it is not a standard-size notebook but is physically identical to PN-87-05-08. The front cover is stamped "Note Book." The book contains 123 numbered pages; the entries run from the back to the front of the book.
This was microfilmed at a reduction ratio of 15:1. Courtesy of Thomas Edison National Historical Park.