This notebook was used by Edison during December 1903. Most of the entries pertain to x-ray experiments. Included are notes regarding efforts to find sources of radium and to discover radiation in addition to x-rays. Near the end of the book are scattered notes and drawings relating to storage batteries and phonographs. The book contains 150 numbered pages followed by 11 unnumbered pages. Some pages are blank, and several pages have been removed from the back of the book.