{ Center , or Centre, punch }.
(Mech.) (a) A punch for making indentations or dots in a piece of work, as for suspension between lathe centers,
etc. (b) A
punch for punching holes in sheet metal, having a small conical center to insure correct
locating.
{ Cen"ter , or Cen"tre, seal }. (Gas Manuf.)
A compound hydraulic valve for regulating the passage of the gas through a set
of purifiers so as to cut out each one
in turn for
the renewal of the lime.
{ Cen"ter , Cen"tre } (?), v. t. 1.
To place or fix in the center or
on a central point.
Milton.
2. To collect to a
point; to concentrate.
Thy joys are centered all in me alone.
Prior.
3.
(Mech.) To form a recess or indentation for the reception of a center.
{ Cen"ter , Cen"tre } v.
i. [imp. & p. p. Centered or Centred (&?;); p. pr.
& vb. n. Centering or Centring.]
1. To be placed in a center; to be central.
2. To be collected to a point; to be concentrated; to rest on, or gather about, as a center.
Where there is no visible
truth wherein to center, error is as wide as men's fancies.
Dr. H. More.
Our hopes must center in ourselves alone.
Dryden.
Cen"ter (?), n. [F. centre, fr. L. centrum, fr. round which a
circle is described, fr. &?; to prick, goad.]
1. A
point equally distant from the extremities of a line, figure, or body, or from
all parts of the circumference of a circle; the middle point or place.
2. The middle or
central portion of anything.
3. A principal or important point of concentration; the nucleus around which things are gathered or to which they
tend; an object of attention, action, or force; as,
a center of attaction.
4. The earth. [Obs.]
Shak.
5. Those
members of a legislative assembly
(as in France) who support the existing government. They sit in the middle of
the legislative chamber, opposite the presiding officer, between the conservatives or monarchists, who sit on the right of
the speaker, and the radicals or advanced republicans who occupy the seats on his
left, See Right, and Left.
6. (Arch.) A temporary structure upon which the materials of a
vault or arch are supported in position until the work becomes self-supporting.
7.
(Mech.) (a) One of the two conical steel pins, in a lathe,
etc., upon which the work is held, and about which it revolves. (b)
A conical recess, or indentation, in the end of a shaft or other work, to receive the point of a center, on which the work can turn, as in a lathe.
&fist; In a lathe the live center is in the spindle of the head stock; the dead center is on the tail stock. Planer centers are stocks carrying centers, when the object to
be planed must be turned on its
axis.
Center of an army,
the body or troops occupying the place in the
line between the wings. -- Center of a curve or surface (Geom.) (a) A point such that every line drawn through the point and terminated by the curve
or surface is bisected at the point. (b) The fixed point of reference in polar coördinates. See Coördinates. -- Center of curvature of a curve (Geom.), the center of
that circle which has at
any given point of the
curve closer contact with the curve than has any
other circle whatever. See Circle. -- Center
of a fleet, the division or column between the van and rear, or between the weather division and the lee. -- Center of gravity (Mech.),
that point of a body about which all its parts can be balanced, or which being supported, the whole body will remain at rest, though acted upon by gravity. -- Center of gyration (Mech.), that point in
a rotating body at which the
whole mass might be concentrated
(theoretically) without altering the resistance of the intertia of the body to angular acceleration or retardation. -- Center of inertia (Mech.), the center of
gravity of a body or system of bodies. -- Center of motion, the point which remains at rest, while all the
other parts of a body move round it. -- Center of oscillation, the point at which, if the
whole matter of a suspended body were collected, the time of oscillation would be the same as it is in the actual
form and state of the
body. -- Center of percussion, that point in
a body moving about a fixed axis
at which it
may strike an obstacle without communicating a shock to the
axis. -- Center of pressure
(Hydros.), that point in a surface pressed by a fluid, at which, if a force equal to the whole
pressure and in the same line be applied in a contrary
direction, it will balance or counteract the whole pressure of the fluid.
Hear it pronounced