One of the sloping sides of the lower part of a blast furnace; also, one of the hollow iron or brick sides of the bed of a puddling or boiling furnace.

The lower part of a blast furnace, which slopes inward, or the widest space at the top of this part.

a cylinder inside the furnace where the raw ingredients were mixed and melted

The section of a blast furnace between the hearth and the stack, where iron ore is reduced to iron metal.

Sloping of the cupola lining to form a smaller diameter just above the tuyeres. See Cupola, Tuyeres.