This notebook covers the period December 1887-November 1888. All entries are by Edison. Included are several notes to John Ott, written about December 12, 1887, in regard to proposed experiments on a pyromagnetic generator, arc lights, telephones, batteries, carbonization, and the use of a thermostatic meter strip as a meter, as well as experiments to "ascertain if there is any substance which stands the lines of magnetic force." There are also some drawings of the phonograph dating from September and November 1888. The remaining entries are undated and consist of notes on experiments to determine whether iron "is a non conductor of electric stress." Some of these notes also contain Edison's speculations about the electromagnetic properties of the ether. The pages are unnumbered. Approximately 120 pages have been used. Courtesy of Thomas Edison National Historical Park.