05/03/1880 Cartwright, A D to Edison, Thomas Alva
Metals and minerals; Ore milling and separation [Marginalia by Edison, Thomas Alva]
[D8034]  Document File Series -- 1880: (D-80-34) Mining -- Mines & Ores
[D8034ZBU; TAEM 54:706]
Courtesy of Thomas Edison National Historical Park.