This notebook covers the period April 1909-August 1910. All entries are by Edison. The book is the second of two books that contain notes regarding attempts to find a hard, non- celluloid material for use in phonograph cylinders. Included are entries pertaining to the use of shellac and various other compounds to produce a substance that could be molded but would also be durable enough to sustain more threads per inch on the cylinder. There are several notes indicating Edison's application of the experimental results to disc records. Some of the entries in this book were transcribed from N-09-04-20.1. The pages are unnumbered. Approximately 80 pages have been used.
Courtesy of Thomas Edison National Historical Park.