Along The Tiadaghton: An Environmental History of the Pine Creek Gorge 1st. Petaluma, California: Interprint. 1993: 39, 40, 43, 46, 49, 50. ISBN 0-9635905-0-2
heats ore, burning off undesirable chemicals such as sulphur. A refining furnace melts the metal into a liquid. Undesirable material (or "dross") usually