This notebook contains a few dated entries from March 1880. It consists of notes by Henry A. Rowland on calorimeter tests involving Edison's incandescent lamp. The tests were made to determine the efficiency of the Edison lighting system. Included are data from five separate tests, with associated calculations. The front cover is labeled "From the Laboratory of T.A. Edison Menlo Park, N.J. No. 62." The book contains 23 unnumbered pages.
An online finding aid to the archival collection is available. Courtesy of the Milton S. Eisenhower Library.