This folder contains correspondence and other documents relating to the technical and commercial development of Edison's technologies for ore separation and concentration. Included are items pertaining to a proposed agreement for a business venture with former employee James B. Ballantine; legal advice provided to Edison by his attorney Henry Lanahan; and inquiries about ore-milling technology from Baxter Lewis and Stewarts & Lloyds Ltd., bearing marginal notations by Edison.

Approximately 70 percent of the documents have been selected. The unselected items include a stock transfer, cover letters, and routine requests for information.

Courtesy of Thomas Edison National Historical Park.