This notebook was used by Edison, Absalom M. Kennedy, and others during November-December 1915 for notes on experimental recordings. The first few entries are by Edison. For subsequent entries, the details of the recording session are provided by Kennedy, E. Rowland Dawson, or other experimenters, with frequent comments by Edison on the quality and loudness of the recordings. Some of the entries include notes or drawings regarding the positions of instruments and voices, as well as the position of the recorder and horn. Others are very brief and include only the identifying number of the recorder or horn and a percentage, usually written by Edison, indicating quality and volume as compared to standard. The front cover is marked "Mr. Edison." The pages are unnumbered. Approximately 130 pages have been used.