This notebook covers the period December 1878-February 1879. Most of the entries are by Edison, Charles Batchelor, and Francis Upton. A few entries are by Charles P. Edison and John Kruesi. Many entries are signed by Edison. Almost all of the material relates to experiments on electric lighting. There are notes and calculations about lamp and filament tests, including a numbered series cross-referenced to other notebooks; and notes, drawings, and calculations about generators, some similarly cross-referenced. There are also notes and drawings of the new receiver for the telephone. The book contains 288 numbered pages.

Blank pages: 4-5, 236-237, 280-285.

Courtesy of Thomas Edison National Historical Park.