Puddling furnace

Puddling \Pud"dling\, n.
   1. (Hydraul. Engin.)
      (a) The process of working clay, loam, pulverized ore,
          etc., with water, to render it compact, or impervious
          to liquids; also, the process of rendering anything
          impervious to liquids by means of puddled material.
      (b) Puddle. See {Puddle}, n., 2.
          [1913 Webster]

   2. (Metal.) The art or process of converting cast iron into
      wrought iron or steel by subjecting it to intense heat and
      frequent stirring in a reverberatory furnace in the
      presence of oxidizing substances, by which it is freed
      from a portion of its carbon and other impurities.
      [1913 Webster]

   {Puddling furnace}, a reverberatory furnace in which cast
      iron is converted into wrought iron or into steel by
      puddling.
      [1913 Webster]