[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, Martin N. Force, and John Kruesi relating to experiments on an improved voltameter—a devise used to measure current strength in batteries. A paper by Edison, entitled "The Sonorous Voltameter," was read at the St. Louis meeting of the Association for the Advancement of Science by Professor George Barker on August 23, 1878, and subsequently published in the American Journal of Science, 3rd ser. 16 (1878): 379-380. A transcription appears in The Papers of Thomas A. Edison, Volume 4: The Wizard of Menlo Park, 1878, p. 395. Following his return from St. Louis, Edison conducted further experiments with the voltameter. Numbered pages 1-22, which precede the other notes and drawings in this folder, were copied into Experimental Researches, Vol. 4, pages 175-192. The first page in the series seems to relate to an acoustic device rather than to the voltameter.