The dated entries in this notebook cover the periods March-May 1888 and December 1891-January 1892. At the front of the book are transcriptions of phonograph cylinder experiments conducted by Arthur C. Payne in 1888. From the back of the book forward are notes and calculations by Joseph W. Harris regarding various chemical analyses. Included are notes on ore assays; on a "new method of nickel determination"; and on the search for a substitute for borax, conducted for the Edison Phonograph Works. The front cover is labeled "520." The inside front cover is inscribed "Mr Payne Sepr 3 - 88 #520." The back cover is labeled "Qualitative Analysis Only. Harris." The pages are unnumbered, and several pages have been removed from the book. Approximately 160 pages have been used. Courtesy of Thomas Edison National Historical Park.