This notebook was begun during February 1892. All entries are by Edison. The book contains notes and drawings relating to various electrical experiments. Included are entries regarding the conductivity of iron, magnetism, Foucault currents, telephone transmission, and the optical behavior of iron subjected to alternating current. There are also theoretical notes about the properties of aluminum, along with drawings, notes, and calculations pertaining to ore milling. Among the latter are several pages of cost analyses, probably based upon operations at the New Jersey and Pennsylvania Concentrating Works plant at Edison, N. J. in September 1892. The pages are unnumbered, and the book has been used in both directions. Several pages have been removed from the book. Approximately 110 pages have been used. Courtesy of Thomas Edison National Historical Park.