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.
{ 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 , 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, 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.
{ 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.
{ 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.