This notebook covers the period February-June 1906. All entries are by Edison, except for one by an unidentified experimenter. The book contains Edison's instructions regarding the conduct of storage battery cell endurance tests. In one entry Edison directs the experimenters to send the test results to him at Fort Myers, Florida. The front cover is labeled "Edison Tubes. No. 350 to No. [ ] 2-24-06 to [ ]." The pages are unnumbered. Approximately 30 pages have been used.