This undated notebook was probably used in late April 1901. The book contains notes, primarily by Edison, regarding tests of various alloys for use in thermocouples (see also N- 01-04-15, N-01-04-16, and N-01-04-19). Among the metals involved are antimony, arsenic, bismuth, lead, nickel, tin, and zinc. At the beginning of the book are entries by an unidentified experimenter. One page of notes by Edison has been inserted into the book. The spine is stamped "16[1]." The pages are unnumbered. Approximately 85 pages have been used.