[NA156-N] N-09-07-13 (1909, 1914-1916)
This notebook contains dated entries from 1909 and 1914-1916. All entries are by Edison. The book consists of notes and drawings regarding tests of various chemical compounds for use in phonograph records. The earliest entries indicate that the experiments probably applied to both cylinder and disc records. Inserted into the book is one loose page by Richard G. Berger pertaining to the use of benzene and hydrochloric acid. The front cover is labeled \"Disc Records 1909.\"" The pages are unnumbered. Approximately 50 pages have been used."