gridiron pendulum

2 definitions found

gridiron pendulum - Collaborative International Dictionary of English v.0.48 :

  Gridiron \Grid"i`ron\, n. [OE. gredire, gredirne, from the same
     source as E. griddle, but the ending was confused with E.
     iron. See Griddle.]
     1. A grated iron utensil for broiling flesh and fish over
        coals.
        [1913 Webster]
  
     2. (Naut.) An openwork frame on which vessels are placed for
        examination, cleaning, and repairs.
  
     3. (Sport) A football field; -- so called because of the
        resemblance of the parallel marked yard lines to a
        gridiron[1].
        [PJC]
  
     Gridiron pendulum. See under Pendulum.
  
     Gridiron valve (Steam Engine), a slide valve with several
        parallel perforations corresponding to openings in the
        seat on which the valve moves.
        [1913 Webster]

  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]