This notebook covers the period August-September 1886. The entries are by Edison, Mina Edison, and John F. Ott. The book contains notes, drawings, and calculations relating to lamp experiments. The lamps are numbered I through 80. Loose pages containing the results of lamp tests have been pasted onto many of the notebook pages. On the first page is an inscription by Mina Edison: "East Newark, Aug. 3rd 1886 -- Experiments on increasing the life of electric lamps." The spine is labeled "30." The book contains 203 pages numbered by an archivist. Courtesy of Thomas Edison National Historical Park.