Pendulums

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Pendulum \Pen"du*lum\, n.; pl. {Pendulums}. [NL., fr. L.
     pendulus hanging, swinging. See {Pendulous}.]
     A body so suspended from a fixed point as to swing freely to
     and fro by the alternate action of gravity and momentum. It
     is used to regulate the movements of clockwork and other
     machinery.


     [1913 Webster]
  
     Note: The time of oscillation of a pendulum is independent of
           the arc of vibration, provided this arc be small.
           [1913 Webster]
  
     {Ballistic pendulum}. See under {Ballistic}.
  
     {Compensation pendulum}, a clock pendulum in which the effect
        of changes of temperature of the length of the rod is so
        counteracted, usually by the opposite expansion of
        differene metals, that the distance of the center of
        oscillation from the center of suspension remains
        invariable; as, the {mercurial compensation pendulum}, in
        which the expansion of the rod is compensated by the
        opposite expansion of mercury in a jar constituting the
        bob; the {gridiron pendulum}, in which compensation is
        effected by the opposite expansion of sets of rods of
        different metals.
  
     {Compound pendulum}, an ordinary pendulum; -- so called, as
        being made up of different parts, and contrasted with
        {simple pendulum}.
  
     {Conical pendulum} or {Revolving pendulum}, a weight
        connected by a rod with a fixed point; and revolving in a
        horizontal circle about the vertical from that point.
  
     {Pendulum bob}, the weight at the lower end of a pendulum.
  
     {Pendulum level}, a plumb level. See under {Level}.
  
     {Pendulum wheel}, the balance of a watch.
  
     {Simple pendulum} or {Theoretical pendulum}, an imaginary
        pendulum having no dimensions except length, and no weight
        except at the center of oscillation; in other words, a
        material point suspended by an ideal line.
        [1913 Webster]