This set of forty-eight unbound and numbered pages covers the periods July 1871-January 1872 and August-September 1875. The entries on pages 1-37 are signed by Edison and are in his hand. They deal with the development of automatic printing and chemical telegraphy. Detailed drawings supplement the text. The name of Joseph Murray appears frequently as a witness. The entries on pages 39-48 are in the hand of Charles Batchelor and relate to the electric pen, electromotograph, and battery tests. They are signed by Edison, Batchelor, James Adams, and Edward H. Johnson.

Courtesy of Thomas Edison National Historical Park.