The only dated entry in this notebook is from April 1901. At the beginning of the book are notes by Edison regarding trials of various alloys for use in thermocouples. The metals tested include antimony, bismuth, cadmium, lead, tin, and zinc. Near the end of the book is a series of trials by an unidentified experimenter, possibly John Tronicke, of some of the combinations listed by Edison. The spine is stamped "152." The pages are unnumbered. Less than 20 pages have been used.