This notebook covers the periods October 1894-August 1895 and February 1897-September 1898. It was used by Joseph W. Harris and Jonas Walter Aylsworth, probably at New Jersey and Pennsylvania Concentrating Works in Ogden, N.J. The book contains notes regarding various ore milling operations, including the electrolytic separation of iron ore, the bricking of ore concentrate, oil and lubrication experiments, and the roller feed at the plant. There are also routine ore assays and notes relating to sand volume experiments. The front cover is labeled "Record of work done in Assay Room" and "General Work." The pages are unnumbered. Approximately 160 pages have been used.
The material relating to sand volume experiments and ore assays has not been selected. Courtesy of Thomas Edison National Historical Park.