Source : Webster's Revised Unabridged Dictionary (1913)

Pitch \Pitch\, n.
   1. A throw; a toss; a cast, as of something from the hand;
      as, a good pitch in quoits.

   {Pitch and toss}, a game played by tossing up a coin, and
      calling ``Heads or tails;'' hence:

   {To play pitch and toss with (anything)}, to be careless or
      trust to luck about it. ``To play pitch and toss with the
      property of the country.'' --G. Eliot.

   {Pitch farthing}. See {Chuck farthing}, under 5th {Chuck}.

   2. (Cricket) That point of the ground on which the ball
      pitches or lights when bowled.

   3. A point or peak; the extreme point or degree of elevation
      or depression; hence, a limit or bound.

            Driven headlong from the pitch of heaven, down Into
            this deep.                            --Milton.

            Enterprises of great pitch and moment. --Shak.

            To lowest pitch of abject fortune.    --Milton.

            He lived when learning was at its highest pitch.
                                                  --Addison.

            The exact pitch, or limits, where temperance ends.
                                                  --Sharp.

   4. Height; stature. [Obs.] --Hudibras.

   5. A descent; a fall; a thrusting down.

   6. The point where a declivity begins; hence, the declivity
      itself; a descending slope; the degree or rate of descent
      or slope; slant; as, a steep pitch in the road; the pitch
      of a roof.

   7. (Mus.) The relative acuteness or gravity of a tone,
      determined by the number of vibrations which produce it;
      the place of any tone upon a scale of high and low.

   Note: Musical tones with reference to absolute pitch, are
         named after the first seven letters of the alphabet;
         with reference to relative pitch, in a series of tones
         called the scale, they are called one, two, three,
         four, five, six, seven, eight. Eight is also one of a
         new scale an octave higher, as one is eight of a scale
         an octave lower.

   8. (Mining) The limit of ground set to a miner who receives a
      share of the ore taken out.

   9. (Mech.)
      (a) The distance from center to center of any two adjacent
          teeth of gearing, measured on the pitch line; --
          called also circular pitch.
      (b) The length, measured along the axis, of a complete
          turn of the thread of a screw, or of the helical lines
          of the blades of a screw propeller.
      (c) The distance between the centers of holes, as of rivet
          holes in boiler plates.

   {Concert pitch} (Mus.), the standard of pitch used by
      orchestras, as in concerts, etc.

   {Diametral pitch} (Gearing), the distance which bears the
      same relation to the pitch proper, or circular pitch, that
      the diameter of a circle bears to its circumference; it is
      sometimes described by the number expressing the quotient
      obtained by dividing the number of teeth in a wheel by the
      diameter of its pitch circle in inches; as, 4 pitch, 8
      pitch, etc.

   {Pitch chain}, a chain, as one made of metallic plates,
      adapted for working with a sprocket wheel.

   {Pitch line}, or {Pitch circle} (Gearing), an ideal line, in
      a toothed gear or rack, bearing such a relation to a
      corresponding line in another gear, with which the former
      works, that the two lines will have a common velocity as
      in rolling contact; it usually cuts the teeth at about the
      middle of their height, and, in a circular gear, is a
      circle concentric with the axis of the gear; the line, or
      circle, on which the pitch of teeth is measured.

   {Pitch of a roof} (Arch.), the inclination or slope of the
      sides expressed by the height in parts of the span; as,
      one half pitch; whole pitch; or by the height in parts of
      the half span, especially among engineers; or by degrees,
      as a pitch of 30[deg], of 45[deg], etc.; or by the rise
      and run, that is, the ratio of the height to the half
      span; as, a pitch of six rise to ten run. Equilateral
      pitch is where the two sloping sides with the span form an
      equilateral triangle.

   {Pitch of a plane} (Carp.), the slant of the cutting iron.

   {Pitch pipe}, a wind instrument used by choristers in
      regulating the pitch of a tune.

   {Pitch point} (Gearing), the point of contact of the pitch
      lines of two gears, or of a rack and pinion, which work
      together.

Circle \Cir"cle\ (s[~e]r"k'l), n. [OE. cercle, F. cercle, fr. L.
   circulus (Whence also AS. circul), dim. of circus circle,
   akin to Gr. kri`kos, ki`rkos, circle, ring. Cf. {Circus},
   {Circum-}.]
   1. A plane figure, bounded by a single curve line called its
      circumference, every part of which is equally distant from
      a point within it, called the center.

   2. The line that bounds such a figure; a circumference; a
      ring.

   3. (Astron.) An instrument of observation, the graduated limb
      of which consists of an entire circle.

   Note: When it is fixed to a wall in an observatory, it is
         called a {mural circle}; when mounted with a telescope
         on an axis and in Y's, in the plane of the meridian, a
         {meridian or transit circle}; when involving the
         principle of reflection, like the sextant, a
         {reflecting circle}; and when that of repeating an
         angle several times continuously along the graduated
         limb, a {repeating circle}.

   4. A round body; a sphere; an orb.

            It is he that sitteth upon the circle of the earth.
                                                  --Is. xi. 22.

   5. Compass; circuit; inclosure.

            In the circle of this forest.         --Shak.

   6. A company assembled, or conceived to assemble, about a
      central point of interest, or bound by a common tie; a
      class or division of society; a coterie; a set.

            As his name gradually became known, the circle of
            his acquaintance widened.             --Macaulay.

   7. A circular group of persons; a ring.

   8. A series ending where it begins, and repeating itself.

            Thus in a circle runs the peasant's pain. --Dryden.

   9. (Logic) A form of argument in which two or more unproved
      statements are used to prove each other; inconclusive
      reasoning.

            That heavy bodies descend by gravity; and, again,
            that gravity is a quality whereby a heavy body
            descends, is an impertinent circle and teaches
            nothing.                              --Glanvill.

   10. Indirect form of words; circumlocution. [R.]

             Has he given the lie, In circle, or oblique, or
             semicircle.                          --J. Fletcher.

   11. A territorial division or district.

   Note:

   {The Circles of the Holy Roman Empire}, ten in number, were
      those principalities or provinces which had seats in the
      German Diet.

   {Azimuth circle}. See under {Azimuth}.

   {Circle of altitude} (Astron.), a circle parallel to the
      horizon, having its pole in the zenith; an almucantar.

   {Circle of curvature}. See {Osculating circle of a curve}
      (Below).

   {Circle of declination}. See under {Declination}.

   {Circle of latitude}.
       (a) (Astron.) A great circle perpendicular to the plane
           of the ecliptic, passing through its poles.
       (b) (Spherical Projection) A small circle of the sphere
           whose plane is perpendicular to the axis.

   {Circles of longitude}, lesser circles parallel to the
      ecliptic, diminishing as they recede from it.

   {Circle of perpetual apparition}, at any given place, the
      boundary of that space around the elevated pole, within
      which the stars never set. Its distance from the pole is
      equal to the latitude of the place.

   {Circle of perpetual occultation}, at any given place, the
      boundary of the space around the depressed pole, within
      which the stars never rise.

   {Circle of the sphere}, a circle upon the surface of the
      sphere, called a great circle when its plane passes
      through the center of the sphere; in all other cases, a
      small circle.

   {Diurnal circle}. See under {Diurnal}.

   {Dress circle}, a gallery in a theater, generally the one
      containing the prominent and more expensive seats.

   {Druidical circles} (Eng. Antiq.), a popular name for certain
      ancient inclosures formed by rude stones circularly
      arranged, as at Stonehenge, near Salisbury.

   {Family circle}, a gallery in a theater, usually one
      containing inexpensive seats.

   {Horary circles} (Dialing), the lines on dials which show the
      hours.

   {Osculating circle of a curve} (Geom.), the circle which
      touches the curve at some point in the curve, and close to
      the point more nearly coincides with the curve than any
      other circle. This circle is used as a measure of the
      curvature of the curve at the point, and hence is called
      circle of curvature.

   {Pitch circle}. See under {Pitch}.

   {Vertical circle}, an azimuth circle.

   {Voltaic} {circle or circuit}. See under {Circuit}.

   {To square the circle}. See under {Square}.

   Syn: Ring; circlet; compass; circuit; inclosure.