In 1915, Kennecott Copper Corporation secured a controlling interest in the Braden Copper Company, located near Rancagua, Chile. Includes an account of the history, geology, mining methods and mine safety, with accompanying maps, photographs, and charts, of the Braden Unit of the Kennecott Copper Corporation. This was prepared for the American Mining Congress in 1952-1953; the charts are dated from 1938 through 1952, and the six photographs are of equipment. Also includes a set of blueprints of diamond drilling equipment, dated 1943 to 1952; and construction plans and calculations for various mining operations and buildings.