This notebook was probably used by Edison during the period July-August 1912; the entries dated June appear to have been made in July. The notes and drawings pertain primarily to electroplating processes involved in disc record manufacture. The book begins with notations made throughout the night of July 28th and into the morning of July 29th. This first set of notes ends with the comment "up all night." Included in these and subsequent entries are notes on experiments to determine the best plating solution and conditions for the production of the "master moulds" from which submaster records and working molds were later produced for pressing records. Also included are notes on several attempts to toughen the waxy composition of the initially recorded "white master" discs, so that the first intermediate or "submaster" transfer could be made by pressing rather than electroplating. There is also a comment on Edison's work habits. Edison's notes indicate that David A. Dodd, Harry R. Grimes, Sherwood T. (Sam) Moore, and Frederick P. Ott assisted him in some instances. The front cover is labeled "B." The pages are unnumbered. Approximately 75 pages have been used. Courtesy of Thomas Edison National Historical Park.