This folder contains correspondence and other documents relating to mining and ore milling. Included is correspondence with the firm of Pilling & Crane regarding the status of the Hurd iron mine and assays of zinc ores. Also included is an inquiry enclosing an Edison letter from 1890.

Approximately 50 percent of the documents have been selected. The items not selected are routine inquiries regarding Edison's iron ore separation process and letters of transmittal.