N-03-02-26 (1903, 1905)
This notebook contains dated entries from February, March, May, and July 1903. There is also a 2-page entry from February 1905. All entries are by Edison. Included are notes and drawings pertaining to various experimental projects, such as the hardness and composition of phonograph cylinders, phonographic recording apparatus, etheric force and \"xyz rays,\"" and storage batteries. The pages are unnumbered, and several pages have been removed from the book. Approximately 20 pages have been used."