This notebook was used during November 1904. It contains notes by Edison and an unidentified experimenter regarding storage battery experiments. Included are entries for endurance tests of E-18 type cells arranged in groups, numbered from 24 through 36, with different iron and nickel combinations. An inscription on the inside front cover indicates that groups 1-23 were entered into a "big book." The front and back covers are both marked "Group." The pages are unnumbered. Less than 20 pages have been used.