rabble-arm

from The Century Dictionary.

• noun An arm or rod by which a stirring or agitating action is produced in a bed or mass of ore under treatment in a furnace. In puddling by hand, the molten bath is stirred by the puddler's rabble; in roasting-furnaces where the metal is not in fusion, the mass can be mechanically kept from agglomerating, and every part be exposed to oxidation by a revolving arm or arms producing the action of a rabble.