This pocket notebook is from box 15 in Series 1 of the William J. Hammer Collection. The entries are all from January 1893. The first page contains the inscription "Memoranda of Inventions of Thos. A. Edison." However, only a few inventions are discussed — the electrographic vote recorder of 1869 and the zirconia lamp of 1879. The remainder of the book contains notes regarding tests of commercial Westinghouse lamps. The pages are unnumbered; only 12 pages have been used.

Courtesy of the NMAH Archives Center.