This notebook was used by William Walter Dinwiddie during August-December 1918 for notes on the production of disc record blanks. Edison's supervision of this work is indicated by Dinwiddie's references to his suggestions and his comments that Edison personally tested some of the materials. The experiments are numbered from D101 through D197. The entries indicate differing methods of preparation involving variations in the baking schedules and methods of applying the varnish and the use of different ingredients, combinations of ingredients, and varnishes. There are also illustrations of various ways to set up the presses and molds. Most entries contain comments about the results of the experiments, including whether the disc was too soft, sticky, or stiff and whether it had swell-ups, warps, or cracks. Also included is a description of an experiment "to determine what metals are most liable or less liable to stick to blanks when used as moulds." There are occasional lists of chemicals and other materials ("materials obtained in N.Y."), along with notations regarding their characteristics, sources of supply, and prices. Inserted into the book is a 2-page memorandum from Dinwiddie regarding the procurement of stearic acid in New York City, along with Edison's response. The notes indicate that Charles T. Dally and Ludwig F. (Louis) Ott were working on related experiments. The front cover is labeled "Dinwiddie D-101 -- 200/++/." The pages are unnumbered. Approximately 110 pages have been used. Courtesy of Thomas Edison National Historical Park.