centenary (sentenari)

and n. [L. cen tenarius, consisting of a hundred, relating to a hundred, Centenary solemnities which occurred but once in a hundred years. Fuller . II. n.: pl. centenaries (-riz). 1. The space of a hundred years. One inch of decrease in the growth of men for every cen tenary . Hake will , Apology, p. 49. What I call by this name has grown up in the last cen tenary - a word I may use to signify the hundred years now ending. De Morgan , in Correspondent of Oct. 28, 1865. 2. The commemoration or celebration of the hundredth anniversary of any event, as the birth the middle of the universe. In the ancient astron omy this was the earth, or more strictly its middle point, either of which was therefore often called simply the cen ter by the older poets. I will find Where truth is hid, though it were hid indeed Within the centre. Shak., Hamlet, ii. 2. Is there a justice, Or thunder, my Octavio, and he Not sunk unto the centre ? Fletcher, Spanish Curate, i. 2. 4. In her., the middle point, whether of the whole field or of the chief or base. Thus, in the illustration, A is the center of the shield, or the fe e-point, B is the middle chief point, C is the middle base-point, and all three are called centers. B A C Heraldic Center. A , center of the shield, or fe e-point; B , middle chief-point; C, middle 5. One of the points of the two athe-spindles on which an object to be turned is placed, distinguished as the front or live center , on the spindle of the head-stock, and the dead center , on that base-point. of the tail-stock; also, one of two similar points for holding an g an object to be operated on by some other machine, as a planing-machine, and en- abling the object to be turned round on its axis.-6. A point of concentration or diffusion; the nucleus about which or into which things are collected or from which they diverge or emerge: as, a center of attraction; a center of power. These institutions collected all authority into one cen- tre , kings, nobles, and people. J. Adams. The centre of a world's desire. Tennyson , In Memoriam, lxiv. 7. The central object; the principal point; the point of chief interest: as, the center of a diplomatic negotiation.-8. Milit.: ( a ) In an army, the body of troops occupying the middle place in the line, between the wings. (b) In a fleet, the division between the van and rear of the center line of battle, or between the weather and lee divisions in the order of sailing.-9. In marks manship: (a) The part of a target next 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 organization of Fenians. The head center is at the head of the whole, and he has under him various subordinates named district centers, etc. 11. In the French and some other legislative a emblies, the name given to the group of deputies who hold moderate views, intermediate between the Right, or conservatives, and the Left, of which the extreme is the radical party. In the German Reichstag and the Pru ian Landlag the Center consists of the Ultramontane party. (Usu ally with a capital letter.] 12. (a) The mean position of a figure or system: as, the center of ma or of inertia. (See below.) (b) A point such that, if the whole ma considered were concentrated there, some important result would remain unchanged: as, the center of gravity. - Center of a bastion, See bastion. Center of a curve, formerly, the point where two di from it to the curves copied that apposite Center of a dial, the point from which the hour the one. door turns-Center of a flat pencil, of rays, point radiate center of fotinine of the Pencil radiated Center of a from which an corresponding points of the involution, OA × OB is constant.-Center of a sheaf, the point through which all the lines or planes of the sheaf pa . - Center of attraction, an attracting point, whether fixed or movable. Center of buoyancy. Same as center of displacement. - Center of cavity, a metacenter (which see). - Center of col lineation. Same as center of perspective. - Center of con version. See conversion. - Center of curvature of a plane curve at any point, or center of absolute curvature of a twisted curve, the center of the osculating circle. -Center of displacement or of buoyancy, the center of ma of the water displaced by a ship or other floating body.-Center of effort, a point on the sails of a ve el the impingement upon which of the whole force of the wind produces the same effect as that caused by 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 equilibrium.-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 ma of the body were concentrated there while it con tinued to revolve about the same axis, the retardation would be the same as in the actual case. Center of gravity, a point such that, if the whole ma of the body were concentrated there, the attraction of gravity would remain unchanged. Originally and still often used for center of ma and for center of figure. - Center of gyration. See gyration. - 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 producing motion in the body, or bringing it to rest, is equiv alent to a single force applied at this point. It is coincident with the center of ma . Center of magnitude, that point in a body 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 ma , of a material system, a point whose distance from every plane is equal to the average distance of the whole ma from the same plane. This is commonly, but inconveniently, called the center of gravity (which see, above). - 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 former 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 ma of the pendulum were concentrated there, the time of oscillation would remain unchanged. It coincides with the center of percu ion.Center of o ification. See o ification. - Center of percu ion, of a body rotating about an axis, a point such that, if part of the ma were concentrated there and the remainder on the axis, the statical moment of the weight and the moment of inertia would be 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 col lineation and center of homology. - Center of principal curvature, 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. Center of resistance, of a joint, the point where the resultant stre traverses the joint. - Center of similarity or similitude, of two loci, a point from which the radii vectores to the two loci in the same direction are in a constant ratio; the vertex of a cone of which two similar and similarly placed figures are sections. - Center of spherical curvature, the center of the osculating sphere of a twisted curve. - Center of stre or of pre ure, in any surface, the point where the resultant stre traverses the surface. Center of symmetry, a point which bisects the distance between any two corresponding points of a figure having the requisite kind of symmetry. - Center of the harmonic mean. See harmonic.-Equation of the center. See equation. - General center, the old name for that which is now called the center of a curve. - Harmonic center of the nth order. See harmonic.Instantaneous center of rolling, the point of contact. -Nervous centers. See nervous. - Phonocamptic center, a virtual focus of sound. Surface of centers, locus of the centers of principal curvature of a given surface. Syn. Midst, etc. See middle, n. IMG:content-0023.png:[blocks in formation] Life's choicest ble ings centre all in home. Cowper . Religion is not an exclusive impulse. It does not grow from an emotion that is centred wholly upon God and seeks no other object. Channing, Perfect Life, p. 5. center?, centre2 (sen'ter), n. [Also formerly centry; a modification, in simulation of center (with which the word is now confused), of the F. cintre, centry or mould an arch, earlier cinter, cintre, it is upheld in building" (Cotgrave), mod. F.cintre, center, centering, an arch, semicircle (ML. cintrum, cintorium ), = Cat. cindria = Sp.cimbra, formerly also cimbria, = It. cent in a, a center, centering, frame for arch-work; from the verb, F. cintrer = Sp. cimbrar = It. cent in are, arch, Cynter or [read of ] masunry [var. cyynt of masonrye], cintorium. Prompt . Parv ., p. 78. center-bar (sen'ter-bär), n. 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' boring-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 removes the wood within the circle of the scriber. See bit1 , 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 proce of cutting out a cylindrical countersink around this, as, for example, to receive the head of a screw-bolt. center-block (sen'tėr-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), n. A shifting keel pa ing 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 IMG:content-0024.png:[merged small][merged small][merged small][ocr errors]