This notebook covers the period February-July 1879. Most of the entries are by Edison, Charles Batchelor, and Francis Upton. A few entries are by John Kruesi. Included are notes, calculations, and drawings of generators; calculations about electric power distribution; drawings of telephones and central exchange systems; notes and drawings of dynamometers; and notes and calculations about thermoelectricity experiments. Also included are a memorandum by Edison on the English telephone business and a memorandum by Batchelor on outfitting the Jeannette for the New York Herald's arctic expedition. The book contains 274 numbered pages.

Blank pages: 110-111, 200-205, 222-225, 260-273.

Missing page numbers: 99-100, 113-114, 173-188.

Courtesy of Thomas Edison National Historical Park.