This notebook was used during the period April-November 1882 to record test results on large dynamos at the Edison Machine Works in New York City. The entries are by unidentified experimenters. At the beginning of the book is a notation by Clarke from 1928 indicating that it is a "page by page copy from a like note-book of the testing room at the Edison Machine Works, Goerck St., New York City." There are several additional entries signed by Clarke and dated January 8, 1931. The label on the front cover is inscribed "Electrical Experiments and Tests" and "Edison 'Jumbo' Dynamos." The pages are irregularly numbered; approximately 65 pages have been used. Courtesy of the Henry Ford Museum and Greenfield Village Research Center.