Unbound Notebooks, Vol. 9 (1875)
This volume covers the period August-December 1875. The notes and drawings are by Edison and Charles Batchelor, and the names of James Adams and Edward H. Johnson occasionally appear as witnesses. Most of the material relates to acoustic telegraphy. There are also notes and drawings of etheric force experiments and a drawing of a pen for an autographic telegraph. The volume consists of 23 numbered, unbound pages, many of which appear to have been removed from a scrapbook. Some of the pages in Scrapbook Fragment, Cat. 30,100 (Miscellaneous Shop and Laboratory Notebooks) were probably also removed from the same scrapbook.
Missing pages: 1-2, 4, 14-16. Additional pages missing from this volume can be found in facsimile in the Telephone Interferences."