[The following note describes a series of notebooks and has no document records attached to it. For that reason, a "no Documents found" message will appear if the "List Documents" button at the bottom of the note is used. To see the records in the notebooks described here, use the "Which Series Notes?" button to enter the Series Notes or use the "Next Text" button to move to the first item in the series.]
These twelve notebooks relate to the work of William Walter Dinwiddie and his assistants on the composition and manufacture of disc records during the years 1918-1920. The experiments are numbered from D1 through D821, although not all numbers have been used. Edison's involvement in the research is indicated primarily by the comments of other experimenters; there also infrequent notations and instructions in Edison's hand. Included are experiments aimed at producing the "perfect" record blank in terms of ingredients, varnishes, and the manufacturing process (mixing, pressing, baking, molding, and printing). Also included are occasional entries listing various chemicals and their characteristics or sources of supply, presumably to determine the best ones to use in the experiments.
Experiments by Dinwiddie that are related to, but not directly connected with, the "D" experiments are described in N-19-08-20 [not selected]. The entries in N-19-04-23.1, N-20-03-01.1, and N-20-04-12 [not selected] are by Dinwiddie's assistants, Henry G. Atkinson, W. R. Simpson, Henry E. Thayer, and John Weichmann. The notes also indicate the involvement of Charles T. Dally, Elmer E. Dougherty, Charles G. Kircher, Ludwig F. (Louis) Ott, and others. Some of the experiments involve the use of mixes prepared in the C. T. Dally Disc Blanks Composition Books. Some of the "D" blanks described in Dinwiddie's books were used for further experiments documented in Dally's books.
Four notebooks, representative of the work in the other books, have been selected for their numerous references to Edison's involvement in the experiments.