There are no dated entries in this notebook. The book probably dates from 1879. Most of the entries are by Francis Upton. There are also entries by Edison and Charles Batchelor. The material by Upton consists of notes, drawings, and calculations relating to electric lighting costs, lamp and generator tests, generator design, and electric power distribution. The material by Edison includes calculations and drawings of regulators, notes on tests with an electric engine, and calculations relating to lamps. There are also notes by Batchelor on tests of a small dynamo and notes by an unknown laboratory assistant on experiments to determine the conductivity of various substances. The book contains 282 numbered pages.
Blank pages: 208-211, 270, 273.
Missing page numbers: 271-272. Courtesy of Thomas Edison National Historical Park.