This notebook covers the period July 1879. Many of the entries are by Francis Upton. There are also entries by Edison, Charles Batchelor, and Francis Jehl. Material by Upton consists primarily of calculations relating to conductors, electric power distribution, and generators. Material by Edison includes notes and drawings of filaments and lamps; drawings and calculations relating to electric power distribution; notes on thermoelectricity experiments; notes on journal articles; and notes on induction coils for the telephone. There are also drawings by Batchelor of the telephone and notes by Jehl on wire tests. The book contains 282 numbered pages.

Blank pages: 148-149, 194-253, 256-273.