This notebook was used during June-July and December 1920 by Edison, Walter N. Archer, and W. J. Taylor. The entries pertain to the plating processes involved in the manufacture of disc records. The early entries by Edison focus on attempts to copperplate with anodes made from nickel-faced copper molds no longer needed for production. Following these entries are tabular reports of various molds plated in "Bath 3" in June and July with information on the date and time, specific gravity, volts, amps, crock temperature, and other conditions during plating. Notes, suggestions, and instructions by Edison are interspersed throughout the early tables. An additional page of instructions by Edison has been inserted into the book. The entries for December describe unsuccessful efforts to plate a working mold from an actual record. The front cover is labeled "Baths Disc" and is marked "D[3]." The pages are unnumbered. Approximately 80 pages have been used.