The Collaborative International Dictionary of English v.0.48:
Compasses \Com"pass*es\, n., pl.
An instrument for describing circles, measuring figures,
etc., consisting of two, or (rarely) more, pointed branches,
or legs, usually joined at the top by a rivet on which they
move.
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Note: The compasses for drawing circles have adjustable pen
points, pencil points, etc.; those used for measuring
without adjustable points are generally called
dividers. See Dividers.
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Bow compasses. See Bow-compass.
Caliber compasses, Caliper compasses. See Calipers.
Proportional, Triangular, etc., compasses. See under
Proportional, etc.
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The Collaborative International Dictionary of English v.0.48:
Caliber \Cal"i*ber\, Calibre \Cal"ibre\, n. [F. calibre, perh.
fr. L. qualibra of what pound, of what weight; hence, of what
size, applied first to a ball or bullet; cf. also Ar.
q[=a]lib model, mold. Cf. Calipers, Calivere.]
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1. (Gunnery) The diameter of the bore, as a cannon or other
firearm, or of any tube; or the weight or size of the
projectile which a firearm will carry; as, an 8 inch gun,
a 12-pounder, a 44 caliber.
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The caliber of empty tubes. --Reid.
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A battery composed of three guns of small caliber.
--Prescott.
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Note: The caliber of firearms is expressed in various ways.
Cannon are often designated by the weight of a solid
spherical shot that will fit the bore; as, a
12-pounder; pieces of ordnance that project shell or
hollow shot are designated by the diameter of their
bore; as, a 12 inch mortar or a 14 inch shell gun;
small arms are designated by hundredths of an inch
expressed decimally; as, a rifle of .44 inch caliber.
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2. The diameter of round or cylindrical body, as of a bullet
or column.
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3. Fig.: Capacity or compass of mind. --Burke.
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Caliber compasses. See Calipers.
Caliber rule, a gunner's calipers, an instrument having two
scales arranged to determine a ball's weight from its
diameter, and conversely.
A ship's caliber, the weight of her armament.
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The Collaborative International Dictionary of English v.0.48:
Calipers \Cal"i*pers\, n. pl. [Corrupted from caliber.]
An instrument, usually resembling a pair of dividers or
compasses with curved legs, for measuring the diameter or
thickness of bodies, as of work shaped in a lathe or planer,
timber, masts, shot, etc.; or the bore of firearms, tubes,
etc.; -- called also caliper compasses, or caliber
compasses.
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Caliper square, a draughtsman's or mechanic's square,
having a graduated bar and adjustable jaw or jaws.
--Knight.
Vernier calipers. See Vernier.
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