Bellows

The bellows belong to the metalworker's furnace, and scripture takes the smith's apparatus up into a figure of failed refining.

The Founder's Furnace

In Jeremiah's indictment of Judah, the smelting yard becomes the picture of a nation that will not be purified: "The bellows blow fiercely; the lead is consumed of the fire: in vain they go on refining; for the wicked are not plucked away" (Jer 6:29). The bellows do their work, the lead — the flux that should carry off impurity — is spent, but the dross of wickedness remains; the technology is sound, the people are not.