This notebook was used by William Walter Dinwiddie during December 1918-February 1919 for notes on the production of blanks and prints for disc records. There is one additional entry from March 1920. Edison's supervision of this work is indicated by occasional notations in his handwriting and by Dinwiddie's references to his suggestions and comments. The experiments are numbered from D201 through D347. The entries describe different methods of preparation and contain remarks about the results of the experiments, including how the prints made from each blank sounded. Several entries mention that a particular print sounded good or bad to Edison or that "Mr. E can not hear surface." Some entries note the expansion of blanks over a number of days. Also included are lists of chemicals and pigments, along with notations regarding their characteristics and sources of supply. The front cover is labeled "Dinwiddie Varnish D-201 -- Next book is 401--." The pages are unnumbered. Approximately 160 pages have been used. Courtesy of Thomas Edison National Historical Park.