This notebook covers the periods May 1907 and October 1910. All entries are by Edison. The book contains notes and drawings regarding attempts to amplify phonograph recordings using an electromotograph. Included are tests of numerous compounds in the motograph cylinder, with some notations of the resulting sound quality. There are also entries relative to the wear on phonograph cylinders after repeated use. The front cover is labeled \"Emg.\"" The pages are unnumbered. Approximately 40 pages have been used.