This notebook is a continuation of N-13-08-25.2. It was used by Edison and Peter C. Christensen during the period June 1914-February 1915 for a sequence of numbered "tracking tests" to improve the quality of the "white master" records. Preceding the tests are entries by Christiansen alone [not selected] listing various experimental preparations of wax compounds and phenol resins. The notes indicate that an employee named Miller (probably Joseph Miller) worked with Edison. The spine is labeled "Testing #2." The pages are unnumbered. Approximately 50 pages have been used. Courtesy of Thomas Edison National Historical Park.