This notebook was used during June-July 1920 and December 1920-March 1921 by Edison, Walter N. Archer, Frank Detlef, Jr., and Howard F. Redford. The entries pertain to the plating processes involved in the manufacture of disc records. The first part of the book contains tabular reports similar to the ones in previous books such as N-20-06-08.1. The reports provide a daily record of molds plated in \"Bath 4\"" using scrapped molds for anodes or cast copper anodes. A few notations by Edison appear on the early entries. The second half of the book contains entries from December 1920-March 1921 for plating experiments, numbered 51-160, that continue the experiments begun in N-20-06-09. The entries focus on improvements in the copper plating process. Among the numerous items inserted into the book are notes and instructions from Edison to Archer, as well as notes from Detlef and Redford to Archer with results noted in the daily record. The front cover is labeled \""Baths.\"" The pages are unnumbered. Approximately 180 pages have been used."