This notebook contains dated entries from February 1901 and October 1902. At the beginning of the book are 3 pages of notes by Edison regarding renovations planned for the ore milling plant at Ogden, New Jersey. The remaining pages contain notes and drawings, probably by P. F. Cowing, relating to the use of hard rubber separators for storage battery cells. Several loose pages of Cowing's notes have been inserted into the book. The pages are unnumbered. Approximately 30 pages have been used.