This notebook covers the period May 1889-November 1893. The first set of entries are by Edison and consists of notes and drawings regarding ore milling, including a "wet separation" process. The following entries are by Edison associate William K. L. Dickson and include notes, drawings, and calculations regarding separation and analysis of Cornwall ore. The front cover is marked "3." The inside front cover is inscribed "T A Edison May 18. 89 #549." The pages are unnumbered, and the book has been used in both directions. Approximately 50 pages have been used. Inserted into the book are 10 numbered pages containing notes, drawings, and calculations by Dickson, entitled "Final Result of Expts on Bar Magnets - Ogden."