center 
line of battle, or between the weather and lee 
divisions in the order of sailing. 9. In >it<irlcs- 
manuliii> : (a) The part of a target ne xt the bull's- 
eye. Hence (b) A shot striking the target 
within the circle or square next the bull's-eye. 
10. The title given to the leaders of the or- 
ganization of Fenians. Tin- /./ ,-,/,-/ is at tin- head 
of llir whole, ami lit- h;i under him various subordinates 
named <//>/ '"<'' '' '/'/x, etc. 
11. In the French and some other legislative 
assemblies, the mime given to the group of 
deputies who hold moderate views, interme- 
diate between the Jtiylit, or conservatives, and 
the Left, of which the extreme is the radical 
party. In the German Keiclwtan ami the Prussian Land- 
tag tin- Center consists of the Ultramontane party. [Usu- 
ally with a capital letter.] 
12. () The mean position of a figure or sys- 
tem: as, the center of mass or of inertia. (See 
below.) (6) A point such that, if the whole mass 
considered were concentrated there, some im- 
portant result would remain unchanged : as, the 
ITU/IT of gravity. - Center of a bastion. See/<*(/. 
Center Of a curve, formerly, the point where two ill- 
ameters eoneiir ; now, u point such that every radius vector 
from it to tlie curve i.s accompanied by an equal and opposite 
one. Center of a dial, the point from which the hour- 
lines radiate. Center Of a door, the pivots on which the 
door turns. - Center of a flat pencil, of rays, the point 
from which the lines of the pencil radiate. Center Of an 
Involution, a point, < ), such that, if A and U he any pair of 
corresponding points of the involution, OA x OH is mn 
slant. - Center Of asheaf, the point through which all the 
lines or planes of thesheaf pass. Center Of attraction, 
an attracting point, whether fixed or movable. Center 
Of buoyancy. Hame as center (if displacement. Center 
Of cavity, a metacenter (which see). Center Of COllln- 
eation. Same as center of iwrxjiectice. Center of con- 
version. See cniuvrxitnt Center of curvature of a 
plane curve at any point, or center of absolute curva- 
ture of a twisted curve, the center of the osculating circle. 
Center of displacement or of buoyancy, the center 
of mass of the water displaced hy a ship or other floating 
body. Center Of effort, a point on the sails of a vessel 
the impingement upon which of the whole force of the wind 
produces the same effect as that caused hy the wind when 
uniformly distributed on the system of sails. Also called 
center-velic and velic point. Center Of equilibrium, of 
bodies immersed in a fluid, a point such that, if the system 
were suspended from it, the whole would remain in equi- 
librium. Center of figure, a point whose distance from 
every plane equals the average distance of the whole figure 
from the same plane. Center Of force, an attracting or 
repelling point. -Center of friction, of a body resting 
on a base and turning round a vertical axis, a point on the 
base at such a distance from the axis of rotation that, if the 
mass of the body were concentrated there while it con- 
tinued to revolve al>out the same axis, the retardation 
would be the same as in the actual case. Center of 
gravity, a point such that, if the whole mass of the body 
were concentrated there, the attraction of gravity would 
remain unchanged. Originally and still often used for 
center of mans and tor center of figure. Center Of gyra- 
tion. See gitmtion. -Center of homology. same as 
center of perspective. Center of Inertia, that point in a 
body which is so situated that the force requisite for pro- 
ducing motion in the body, or bringing it to rest, is equiv- 
alent to a single force applied at this point. It is coinci- 
dent with the center of max*. Center of magnitude, 
that point in a liody which is equally distant from all the 
similar external parts of it. In the regular solids this part 
coincides with the center of gravity. Center of mass, < 'f 
a material system, a point whose distance from every plane 
is equal to the average distance of the whole mass from the 
same plane. This is commonly, but inconveniently, called 
thecenter of gravity (which see, atiove). Center of mean 
distances, of points on a right line, such a point on the 
line that the algebraic sum of its distances from the for- 
mer points vanishes. Center Of motion, a point which 
remains at rest while all the other parts of a body move 
round it. Center of oscillation, a point in a pendulum 
such that, if the whole mass of the pendulum were con- 
centrated there, the time of oscillation would remain un- 
changed. It coincides with the center of percussion. 
Center of ossification. See ossification. Center of 
percussion, of a body rotating about an axis, a point such 
that, if part of the mass were concentrated there and the 
remainder on the axis, the statical moment of the weight 
and the moment of inertia would he the same as in the 
actual case. Center of perspective, the point which is 
collinear with every pair of corresponding points of two 
figures in perspective. Also called center of collinealiitn, 
and center of hoinology. Center of principal curva- 
ture, of a surface, the centers of the maximum or minimum 
osculating circles at any point. Center of projection, 
a point from which are projected right lines to every point 
of a figure, and planes to every line of the figure. Cen- 
ter of resistance, of a joint, the point where the resul- 
tant stress traverses the joint. Center of Similarity or 
similitude, of two loci, a point from which the radii vec- 
tores to the two loci in the same direction are in a constant 
ratio ; the vertex of a cone of which two similar and simi- 
larly placed figures are sections. Center Of spherical 
Curvature, the center of the osculating sphere of a twisted 
curve. Center of stress or of pressure, in any surface, 
the point where the resultant stress traverses the surface. 
Center of symmetry, a point which bisects the dis- 
tance Itetween any two corresponding points of a figure 
bavins; the requisite kind of symmetry. Center of the 
harmonic mean. See txinmnnc. Equation of the 
center. See equation. General center, the old name 
for that which is now called the center of a curve. Har- 
monic center of the nth order, 'see harmonic. 
Instantaneous center of rolling, the point of contact. 
Nervous centers. See aermm*. Phonocamptlc 
center, a virtual focus of sound. Surface of centers, 
the locus of the centers of principal curvature of a given 
surface. = Syn. Midst, etc. See middle, n. 
B8B 
Center 1 , centre 1 (scn'ter), r.; pret. and pp. 
/intfi'ffl or centred, ppr. <</<;/</ or centriiiii. 
[< center 1 , /,, 1, ,/. ] J. tnum. 1. To place on 
a center ; fix on a central point. 
One foot he centred, and the other turn'd 
Round through the vast profundity obscure. 
MMun, r. L., viL 228. 
2. To collect to a point. 
Thy joys are centred all in me alone. Prior. 
II. intrant. 1. To be placed in a center or in 
the middle. 
As God in heaven 
Is centre, yet extends to all ; so tlwu [earth], 
(Vf/f/V/M, rereh'st from all tho^r orhs. 
Millim, P. L., ix. 109. 
2. To meet or be collected in one point ; be 
concentrated or united in or about a focus, lit- 
erally or figuratively. 
Our hopes iiiu>t i-i'iifi-i' on ourselves alone. Dryden. 
Life's choicest blessings centre all in home. C'" / < . 
Religion is not an exclusive impulse. It does not grow 
from an emotion that is centrett wholly upon God and seeks 
no other object. dianniny, Perfect Life, p. 6. 
center 2 , centre 2 (sen'ter), n. [Also formerly 
iviiiri/ ; a modification, in simulation of center^ 
(with which the word is now confused), of the 
earlier cintcr, cintre, < ME. cynter, < OF. cinti'< . 
F. cintre, "a centry or mould for an arch, the 
frame of wood whereon it is built, and whereby 
it is upheld in building" (Cotgrave), mod.F. atn- 
Ire, center, centering, an arch, semicircle (ML. 
cintrum, cintoriiuii), = Cat. cindria = Sp.cimlirii. 
formerly also cimbria, = It. centina, a center. 
centering, frame for arch-work ; from the verb, 
F. cintrer = Sp. cimbrar = It. centinare, arch, < 
ML. "ciiicturare, girdle, inclose as with a girdle, 
< cinetura, OF. eeintnre, cinture, a girdle: see 
ceinture, cincture. By the confusion with >< - 
ter^ (L. centrum), and for other reasons, the word 
has suffered unusual changes of form. Cf . cen- 
tering^.^ An arched frame on which the arch 
of a bridge or any vaulted work is supported 
during its construction : same as centering 2 . 
Cynter or [read of] masuury [var. cyynt of masonrye], 
cintorium. ]'f>iiipt. Pare., p. 78. 
center-bar (sen'ter-bar), . In a drilling- or 
boring-machine, an arbor to which the cutting- 
tools are made fast: a boring-bar. 
center-bit (sen'ter-bit), n. A carpenters' bor- 
ing-tool, having a central point or pivot and 
two wings, called a scriber, or vertical cutting 
edge for severing the fibers in a circular path, 
and a router, which cuts horizontally and re- 
moves the wood within the circle of the scriber. 
See tit 1 , 5 plug center-bit, a modified form of the 
ordinary center-bit, in which the center-point or -pin is 
enlarged into a stout cylindrical plug, which may exactly 
fill a hole previously bored, and guide the tool in the pro- 
cess of cutting out a cylindrical countersink around this, 
as, for example, to receive the head of a screw-bolt. 
center-block (sen'ter-blok), n. A wooden block 
put under the center-plate of a car-truck to 
raise it to the required height. 
center-board (sen'ter-bord), . A shifting 
keel passing through a slot in a boat's bottom 
and swinging on a pin at the forward lower 
corner. It is capable of being hoisted or lowered in a 
vertical casing or well. When lowered below the boat's 
bottom, it acts as a projecting keel ; and when triced up 
v 
center-rail 
center -chuck (sen'tcr-chuk), . A chuck which 
can lie screwed (in the mandrel of a lathe, and 
has a hardened steel cone or center fixed in it ; 
also, a projecting arm or driver. 
center-drill (sen'ter-dril), n. A small drill 
used for making a short hole in the ends of a 
shaft about to be turned, for the entrance of 
the lathe-centers. 
center-fire (sen'ter-fir), a. Having the primer 
or fulminate in the center of the base : opposed 
to rim-fire : used of car- 
tridges. Also central- 
tin . 
center-gage (sen ' ter - 
gaj ) . M . A guide or gage 
used in centering work 
in a lathe. 
center-guide ( sen'ter - 
gid), H. A channel or 
course for guiding the 
chain of a differential 
pulley. 
centering 1 , centring 1 (sen'ter-ing, -tring), . 
[< cent < ft, cfiitrc^, + -</!.] The act of focus- 
ing; specifically, the operation of bringing the 
centers of a set of lenses into line. 
centering-, centring 2 (sen'ter-ing, -tring), n. 
[< center*, centre 2 , + -in*/ 1 .] The framing of 
timber by which an arch, as of a bridge or any 
vaulted work, is supported during its erection. 
The centering of a bridge, like that of any other arch or 
vault, serves to keep the stones or voussoirs in position 
Center-gage. 
At A is shown the manner of 
gaging Hie an^lc to which a 
lame-center should tic turned : 
at fi, the angle to which a screw. 
thread cutting-tool should be 
ground ; and at C. the correct- 
ness of the angle of a kcrew- 
MMU already cut. 
A, center-board up; a, center-board down: /?, center-board tnmk. 
by a tackle at the after end, it is completely housed within 
the boat, reducing her draft to that of the keel proper. 
In England often called drop-keel. The center-board is 
a characteristic feature of the racing-craft of the United 
States, constituting a peculiar type in yachts and cat-boats. 
center-chisel (sen'ter-chiz'el), n. A cold-chisel 
with a sharp point, used for marking the cen- 
ter of work in boring metals. 
Centering, Waterl 
till they are keyed in, that is, fixed by the placing of the 
requisite number of stones in the center. The construc- 
tion of the centering is a matter demanding the utmost 
care of the architect or builder. The removal of the wood- 
en framework is called xtriHnft the centering, and on this 
being done what is called the settlement of the arch takes 
place, the central votissoirs sinking a little, and those in the 
flanks rising. Also center, centre, and formerly rinter, cintre. 
If a framework for the centring of the dome were to be 
built up from the ground, they stood aghast at the quan- 
tity of timlMjr required for it. 
C. E. Norton, Church-building in Middle Ages, p. 244. 
Common centering, centering without a truss, but with 
merely a tie-l>eam. 
centering-tool (sen'ter-ing-to'l), . A tool with 
a trumpet-shaped mouth into which the end of 
a shaft may be inserted, and the axis of which 
is occupied by a drill or punch, which may be 
driven forward to drill or punch a hole in the 
exact axial center of the shaft. 
center-lathe (sen'ter-laTH), n. 1. A lathe in 
which the work is supported on centers, one, 
called the front or lire center, on the end of the 
mandrel in the head-stock, and the other, call- 
ed the back or dead center, on the axis in the 
tail-stock ; the latter being adjustable. 2. A 
lathe having two posts from which centers pro- 
ject and hold the work. It is driven by a band mak- 
ing one or more turns about It, and secured at its ends 
to a spring-bar above the lathe and a treadle below it. 
Also called piile-lathe. 
center-mold (sen'ter-mold), n. A templet used 
in making circular stucco ornaments. It is piv- 
oted at the center of the proposed figure and swept round 
over the plastic material, thus forming a figure according 
to the pattern used. 
centerpiece (sen'ter-pes), . An ornament 
intended to be placed in the middle or center 
of something, as of a table, ceiling, or mantel- 
shelf, or between other ornaments. 
He might have missed a centre-piece, or a choice wine- 
cooler. Dickens. 
center-pin (sen'ter-pin), n. The pivot on which 
the needle of a compass oscillates. 
center-plate (sen' ter-plat), . One of a pair 
of plates, usually made of cast-iron, which sup- 
port a car-body on the center of a truck. Car- 
Builder's Diet Body center-plate. See body. 
Center-plate block. See6ta*i. 
center-punch (sen'ter-punch), . A tool con- 
sisting of a small piece of steel with a hardened 
point at one end, used for making an indentation, 
such as to mark the center of a hole to be drilled 
or a circle to be struck, or as a center of revo- 
lution in a lathe. Also called dot-punch and 
prick-punch. 
center-rail (sen'ter-ral), n. In railways and 
tramways, a rail placed between the ordinary 
