[The first paragraph of this note covers all of the Unbound Notes and Drawings for Part I.]
The loose technical notes and drawings constituting this collection cover the years 1873-1878. They relate to a variety of subjects, including telegraphy, electric lighting and power, the electric pen and duplicating press, the telephone, and the phonograph. There are also documents pertaining to various other subjects, such as carbon rheostats, acoustic devices, the tasimeter, and the voltameter. The unbound notes and drawings are organized by year and within each year by subject. Undated notes and drawings, organized by subject, follow the dated material.
This folder contains notes and drawings signed by Edison, Charles Batchelor, John Kruesi, and John F. Ott relating to the cylinder phonograph. The notations on some drawings indicate that they were prepared in connection with the filing of caveats (preliminary patent applications). Also included is a drawing from July 10, 1878, bearing the notation "phonautograph." The phonautograph, invented by Leon Scott in 1857, made a visual image of sound waves on a cylinder but did not play or reproduce any sounds. In July 1878 Edison and Batchelor used a modified version of Scott's invention to monitor noise on the Metropolitan Elevated Railroad. At the end of the folder are two facsimiles from February 1878 prepared for use as exhibits in American Graphophone Company v. Edison Phonograph Works. Courtesy of Thomas Edison National Historical Park.