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

compasses \com"passes\, 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.
   1913 webster

   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.
         1913 webster

   bow compasses. see bow-compass.

   caliber compasses, caliper compasses. see calipers.

   proportional, triangular, etc., compasses. see under
      proportional, etc.
      1913 webster
see also:
dividers bow compasses bow-compass caliber compasses caliper compasses calipers 
proportional triangular compasses 

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

caliber \cal"iber\, 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=alib model, mold. cf. calipers, calivere.
   1913 webster
   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.
      1913 webster

            the caliber of empty tubes.           --reid.
      1913 webster

            a battery composed of three guns of small caliber.
                                                  --prescott.
      1913 webster

   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.
         1913 webster

   2. the diameter of round or cylindrical body, as of a bullet
      or column.
      1913 webster

   3. fig.: capacity or compass of mind. --burke.
      1913 webster

   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.
      1913 webster
see also:
calipers calivere caliber compasses caliber rule a ship's caliber 

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

calipers \cal"ipers\, 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.
   1913 webster

   caliper square, a draughtsman's or mechanic's square,
      having a graduated bar and adjustable jaw or jaws.
      --knight.

   vernier calipers. see vernier.
      1913 webster
see also:
caliper compasses caliber compasses caliper square vernier calipers vernier 

Compasses >> C Words
Compasses, definition of term: Compasses
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Caliber >> C Words
Caliber, definition of term: Caliber
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