This notebook was used by Edison and Frederick P. Ott in July 1918. The book consists primarily of lists of compounds to be tried in chalk telephone cylinders. There is an index to the lists on pages 180-181. Inserted into the book are instructions from Edison to Ott, along with other loose notes. The front cover is labeled "Chalk Telephone (Lists)." The book contains 190 numbered pages preceded by 3 unnumbered pages. Many of the pages are blank. Courtesy of Thomas Edison National Historical Park.