BEAM-BIRD, or Petty-chaps. See MOTACILLA.
BEAM also denotes the lath, or iron, of a pair of scales; sometimes the whole apparatus for weighing of goods is so called: Thus we say, it weighs so much at the king's beam.
BEAM of a Plough, that in which all the parts of the plough-tail are fixed. See AGRICULTURE, no 83. &c.