[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 the tasimeter—a heat measuring device invented by Edison. During the summer of 1878 Edison visited Rawlins, Wyoming, along with a group of astronomers, and used his tasimeter to measure the heat of the sun's corona during its eclipse. On August 23, 1878, he presented a paper entitled "On the Use of the Tasimeter for Measuring the Heat of the Stars and of the Sun's Corona" at the St. Louis meeting of the Association for the Advancement of Science. It was subsequently published in the American Journal of Science, 3rd ser. 17 (1879): 52-54. A transcription appears in The Papers of Thomas A. Edison, Volume 4: The Wizard of Menlo Park, 1878, pp. 432-435.