[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 approximately 25 pages of notes and drawings relating to the telephone. Some of this material was discovered after the microfilm edition of Thomas A. Edison Papers, Part I (1850-1878) was published and was filmed in the Supplement Series of Thomas A. Edison Papers, Part III (1887-1898). Included are three pages of notes and one page of drawings constituting a draft caveat (preliminary patent application) that Edison probably began after the successful design changes and tests of his telephone in March 1878. This caveat was published as Doc. 1269 in The Papers of Thomas A. Edison, Vol. 4.