Trone

n.
  1. A steelyard.
  2. A form of weighing machine for heavy wares, consisting of two horizontal bars crossing each other, beaked at the extremities, and supported by a wooden pillar. It is now mostly disused.
    3. Trone stone ,
    a weight equivalent to nineteen and a half pounds.
    Trone weight ,
    a weight formerly used in Scotland, in which a pound varied from 21 to 28 ounces avoirdupois.