This notebook was used by Edison on June 2, 1920. It contains a single entry describing the procedure for cleaning disc record molds "as man was taught." The process involved two dips into a bath of "8/4," a solution of selenious acid. Inserted into the book is a note from Edison with instructions for Frederick P. Ott regarding the cleaning procedure. The pages are unnumbered. Only 4 pages have been used.

Courtesy of Thomas Edison National Historical Park.