Hastings' Dictionary of the Bible (1898)
FUR'NACE. Furnaces were used for melting the precious metals. Prov 17:3. They were also used to punish criminals. The furnace into which Nebuchadnezzar cast the young Hebrews who refused to worship his image, Dan 3:22-23; cf. Jer 29:22, was probably a large furnace, like a brick kiln, with an opening at the top to cast in the materials; a second, for the removal of slag, cinders, etc., or molten Egyptian Furnace. ) metal, was arranged below, in one of the sides, so that the material in the interior could be observed.