This notebook covers the period January 1879-January 1880. The entries are by Edison, Charles Batchelor, Francis Upton, John Kruesi, and Charles P. Edison. The name of John Ott appears occasionally as a witness. Most of the material relates to electric lighting experiments. Included are drawings of lamps; calculations and drawings of generators; and calculations and notes by Kruesi on the design of dynamo machines, numbers 5-10. There are also notes and drawings of the telephone, including a patent office model; a draft letter by Edison to the Scientific American about the telephone; notes by Kruesi on equipment for the Edison Ore Milling Co., Ltd.; notes and drawings by Kruesi of shafting and belting for the extension of the machine shop; and notes by Batchelor on things to be done. The label on the front cover is marked \"Telephone Sketches.\"" The book contains 280 numbered pages.

Blank pages: 60-61, 66-71, 108-109, 112-113, 136-139, 154-185, 200-277."