N-13-10-31 (1913)



N-13-10-31 (1913)


This notebook was used by Edison during October-November 1913. The entries pertain to the composition of record blanks and to the molding and transfer processes involved in disc record manufacture. At the beginning of the book are notes, which appear to continue from N-13-08-05, involving experimental transfers made with various record blanks. Subsequent entries describe experiments on the composition of discs, particularly the grinding and fineness of the powder for blanks, and on the volatility of different varnish additives. A note by Edison indicates that the volatility experiments were continued by Louis (Ludwig) Ott. The entries for November describe experiments involving the composition of the powder and the Condensite varnish for record blanks, as well as experiments with variations in the pressure used to press blanks. Key ingredients being tested for the varnish include \"para\"" (paraphenylenediamine), \""penta\"" (pentachloraphenol), and \""6/4\"" (hexamethylene tetramine). (Edison filed for a patent for \""para\"" in 1914, which was issued in 1916.) At the end of the book are notes on a series of experiments with various screens, scrapers, and \""tap\"" methods for adding the ground powder to the record blanks. Edison\'s notes indicate that employees Peter Christensen, Archie D. Hoffman, Sherwood T. (Sam) Moore, and Frederick P. Ott assisted him in some instances. A printed table of pressure and temperature values has been pasted onto the inside back cover. The front cover is labeled \""Disc Record 1913.\"" The pages are unnumbered. Approximately 120 pages have been used."



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Notebook Series -- Notebooks by Edison

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Courtesy of Thomas Edison National Historical Park.