This folder contains correspondence and other documents relating to the procurement, sale, and testing of minerals. Many of the items for 1916 pertain to Edison's attempts to obtain raw materials for his various manufacturing operations, such as storage batteries and phonograph discs, under wartime conditions of shortages and higher prices. Included is correspondence with the American Siliconite Co., Canadian Pacific Railway, Eureka Flint & Spar Co., and Foote Mineral Co. in regard to Edison's search for high-potash feldspar. There are also technical notes by Edison and chemical engineer Nathan M. Elias about the process of extracting potash (used in storage batteries) from feldspar, along with correspondence by senior Edison engineer William H. Mason about potash extraction patents held by Harry P. Bassett of Baltimore.
In addition, there is correspondence with consulting engineer William H. Blauvelt of the Semet-Solvay Co. pertaining to Edison's inquiries about calcium chloride liquor and with the Silica Products Co. regarding his interest in calcined magnesite. Other documents deal with tests of asbestos furnished by the Johns-Manville Co. and experiments on the hardness of steel supplied by the Hess Steel Corp. of Baltimore. Items relating to the manufacture of phonograph discs include technical notes by William Walter Dinwiddie on copper recycling in disc molds and correspondence about Edison's search for a cheaper filler to replace precipitated chalk. There are also unsolicited inquiries asking Edison for his opinion of various rocks, minerals, and metals, some of which were tested by experimenter Ludwig F. (Louis) Ott as a basis for Edison's reply.
Approximately 30 percent of the documents have been selected. The unselected material includes form letters sent by Edison to numerous chemical companies requesting quotations on high-grade feldspar, along with replies that were not pursued by Edison because the material was unavailable, too expensive, or of insufficient quality. Also unselected are unsolicited inquiries and requests that received no substantial reply, routine business correspondence of the Edison Storage Battery Co., routine letters about shipping and prices that were handled by Edison's assistant, William H. Meadowcroft, printed scientific literature, samples of powdered rock, and several pages of undated typewritten notes about minerals. Courtesy of Thomas Edison National Historical Park.