This notebook covers the period October-November 1880. Most of the entries are by Francis Jehl. There are also a few entries by Francis Upton. The book contains notes and calculations relating to lamp tests. A few of the entries concern tests of meters. The label on the front cover is marked "Lamps C" and "Francis Jehl." There is an index on the inside front cover. The book contains 282 numbered pages.
Blank pages: 234-235, 264-265. Courtesy of Thomas Edison National Historical Park.