VARIOUS SHOTS, Alcan aluminum smelter, Arvida. A thick cover with a spout is hung from a crane, which places it on a large vat sitting on the ground. Workers make sure the cover is correctly positioned and attach it firmly to the vat. The vat is lifted by a crane and the spout is lowered into a bath from which flames are emanating. The workers watch. The vat is lifted, and the spout comes out of the bath. The vat is moved, and a worker closes a metal flap in front of the bath. The workers are all wearing safety goggles and gloves.