MITRE, in Architecture, is the workmen's term for
an angle that is just 45 degrees, or half a right one.
If the angle be a quarter of a right angle, they call it
a half mitre.
To describe such angles, they have an instrument
called the mitre square; with this they strike mitre
lines on their quarters or battens; and for despatch,
they have a mitre box, as they call it, which is made
of two pieces of wood, each about an inch thick, one
nailed upright on the edge of the other; the upper
piece hath the mitre lines struck upon it on both sides,
and a kerf to direct the saw in cutting the mitre joints
readily, by only applying the piece into this box.