This notebook covers the period December 1878-April 1879. Most of the entries are by Edison, Charles Batchelor, and Francis Upton. There are also entries by John Kruesi, John Ott, and George Jackson. Almost all of the material relates to experiments on electric lighting. There are drawings of lamps, including vacuum experiments; drawings of a machine for insulating spiral filaments; and notes, drawings, and calculations about generators, with a series of numbered experiments cross-referenced to other notebooks. There are also notes by Upton taken from a work by John Tyndall on heat; drawings of telephones; drawings of a blowpipe and of a microscope table; Kruesi\'s notes on work done to the laboratory buildings; and a memorandum by Edison on scrapbook titles. The book contains 282 numbered pages followed by one unnumbered page.

Blank pages: 114-115, 164-165, 220-245, 248-279.

Missing page numbers: 143-144, 161-162.