Part of Arnold Hoffman fonds
File consists of records relating to the Coniaurum mines near Porcupine, Ontario, and the El Canada Colombia Mines Company, which employed Robert Hoffman as a consulting engineer in 1952. File includes correspondence regarding the development of the Coniaurum and El Canada mines; a map of the El Canada mines in Túquerres, Nariño, Colombia; seven vertical cross-sectional drawings of the Coniaurum mines; meeting minutes of El Canada Colombia Mines Company, December 1952; the "Austin Report" on El Canada Mines, written by J.W. Austin in 1929, likely collected by Hoffman after 1934; and a metallurgical report on the gold-bearing ores at El Canada mines, written by E.J. Maust in 1934.