This book covers the period November 1891-June 1893. Most of the entries are by Edison and Charles Batchelor. Other authors include William S. Perry, treasurer, and Walter S. Mallory, vice president. This book contains records of tests, experiments, and mill stoppages; a list of materials and supplies to be kept in stock at the Ogden works; and drawings, cost estimates, calculations, and transcriptions of correspondence. Subjects covered include tests of the rolls, screens, crusher, dryer, and separators. The book contains 301 numbered pages, many of which are blank.
Eighteen loose pages have been inserted into the book. Included are documents in Edison's hand concerning the use of oil, muck tests, and tests with the roller feeds. An analysis of profit and loss appears to be in the hand of Francis Upton. The summaries of muck and assay experiments are by an unidentified author. The 7 pages of unselected loose material include lists of rope drives, pipe, and fittings. Courtesy of Thomas Edison National Historical Park.