This notebook covers the period January-June 1880. Most of the entries are by Francis Upton. Included are calculations relating to tests of carbon filament lamps and a few drawings of circuits used for the tests. Other material includes Edison's earliest drawings and notes on the "Edison Effect" and drawings, probably by Charles P. Mott, of vacuum pumps and lamps. The label on the front cover is marked "Carbon Lamps" and "Upton Resistances." The book contains 171 numbered pages followed by 2 unnumbered pages. The pagination is irregular. Sometimes only the right-hand pages are numbered, and some numbers are used for more than one page. Page 171 is blank.

Missing page numbers: 1-2, 65.