This notebook covers the period August-October 1880. Most of the entries are notes, calculations, and drawings relating to tests of carbon lamps, commencing about 8:00 p.m. on October 6, 1880 and continuing until about 4:00 am. The entries are by Edison, Francis Upton, Francis Jehl, and other laboratory staff members. The few earlier entries also relate to lamp experiments. The label on the front cover is marked "Upton," "Oct 1880," and "Lamps Lot 1." There is an index on the inside front cover. The book contains 282 numbered pages.