bridgel (brij)

[Early mod. E. also bredge; Panel-tru Bridge. brick, stone, iron, steel, or wood. Brick is seldom used alone, except for comparatively small spans, and for unimportant work when stone cannot readily be obtained. In more important works it is often combined with stone, which is introduced to bind, to distribute pre ure, to protect the more exposed portions, and for architectural effect. Stone, wherever it can be used, is the most valuable material, on account of its ma ivene , stability of form, and resistance to the elements; but it is inferior to iron in economy, facility of construction, and ready adaptability to various situations. Among the finest monuments of antiquity are ranked the remains of Roman arched stone bridges. The largest stone Common Tru Bridge. IMG:content-2526.png:[blocks in formation] principal members and sustain the load. The beams are sometimes built of parallel layers of planks, which are made to break joint. In the more important constructions the arches are often compound. They have been employed in modern bridges of considerable magnitude. An arched tru bridge is a form in which the compre ion-member is an arched beam, as in the McCallum tru . In a beam tru bridge the load is supported by beam-tru es or openwork beams. A McCallum Arched-tru Bridge. compre ion-chord and a tension-chord are e ential, and the stre es are transferred from one to the other on their way to the points of support by means of struts and tension-bars, which together are called web-members. See phrases below for other forms. At Trompyngton, nat fer fro Cantebrigge, Ther goth a brook and over that a brigge . Chaucer, Reeve's Tale, 1. 2. 2. The upper line or ridge of the nose, formed by the junction of the two nasal bones.-3. In engraving, a board resting on end-cleats, on which the engraver rests his hand in working. In etching two bridges are used: one with low feet or cleats, to serve for work on the unbitten plate; the other with higher feet, to raise it above the bordering-wax after it has been applied. bridge posed to deck- bridge or top -road bridge.-Box-girder bridge. More commonly called tubular bridge (which see). - Cant a liver bridge, a bridge in which the span is formed by bracket-shaped beam-tru es, extending inward from their supports and connected at the mid. dle of the span either directly or by an intermediate tru of ordinary construction. When piers are used to support the beam-tru es, they are placed near the center of each tru , and not, as in ordinary tru -bridges, at its ends. The strains due to a load upon the span are carried outward toward the ends of the bridge and beyond the piers by bracket-arms similar to those forming the central span, the extremities of which may be secured to other piers to serve the twofold purpose of resisting by their weight the Cant a liver Bridge, Niagara Falls, New York. uplift caused by the load when upon the central span and of themselves supporting vertical pre ure; or they may form part of other spans similar to the central one. This form of bridge presents the great advantage of permitting the construction of the main span without scaffoldings beneath. A fine example is the cant a liver bridge below Niagara Falls, built for the Michigan Central and Canada Southern railways. - Check-bridge of a furnace, a fire bridge: so called because it was supposed to check the draft.-Counterpoise bridge, a bascule-bridge in which counter-weights help to raise the platform. - Electric bridge, a term applied to several contrivances for determining the resistance of an electric circuit, all e entially identical with Wheat stone's bridge (which see, under re sistance). - Floating bridge. (a) A boat, raft, or pontoon bridge. (b) A part of a bridge, supported by a cai on or pontoon, which can swing into and away from the line of roadway. (c) Milit., a kind of double bridge, of which the upper member projects beyond the lower, and is capable of being moved forward by pulleys: used for carrying troops over narrow moats in attacking the outworks of a fort. Flying bridge, a suspension-bridge, or a bridge bridge, a suspension-bridge. The term is generally ap built for temporary as a pontoon bridge. - Hanging plied to the more primitive forms of suspension-bridge.Hoist-bridge. Same as lifting bridge. - Induction bridge. See induction. - Lattice-bridge, a bridge in which the web between the chords or the main compres Lattice-bridge (side elevation). ab a, roadway; d, sleepers; c, transverse beams; d, g, h, stringers;, lattice-ribs; f, cro -beams. sionand tension-members is formed by lattice-work. 4. A wall, generally made of fire-brick, which is built at both ends of a reverberatory furnace, to a certain height, in order to isolate the space in which the metallurgical operation is conducted. The wall nearest the fireplace is called the fire bridge; the other, at the opposite end, the flue - bridge. 5. In gun., the two pieces of timber which connect the two transoms of a gun-carriage. [Eng.] -6. In metal., the platform or staging by which ore, fuel, etc., are conveyed to the mouth of a smelting-furnace.-7. That part of a stringed musical instrument over which the bridge, a swinging bridge balanced upon a pivot. It is strings are stretched, and by which they are A raised above the sounding-board. In bow-instruments, such as the violin, the bridge is arched, in order to allow the bow to strike any one string without touching the others. Leaf-bridge, a hinged lifting bridge. - Lifting bridge, a drawbridge the span of which moves in a vertical plane instead of horizontally. Also called hoist - bridge.-Pivot Pivotor Swing-bridge. 8. Naut., a raised platform extending from side to side of a steamship above the rail, forward of amidships, for the use and convenience often formed by two equal spans, covering a channel on of the officer in charge. It affords him an uninterrupted view, and is furnished with means for communicating, by automatic signals, with the engine-room and the wheel-house. Many large ve els have two bridges, one forward of and one abaft the mainmast; and it is now very common for the bridge to be made in two tiers, one above the other, with often an outlook-station still higher than the upper tier. In sidewheel steamers the bridge connects the paddle-boxes. IMG:content-2527.png:[blocks in formation] ing a bearing for a part of the works. - 10. The balance-rynd of a millstone.-11. In car - build ing, a timber, bar, or beam which is supported at each end.-12. In euchre, a position where one side has scored four points and the other only one.-13. In elect., an apparatus for measuring the resistance of a conductor, the arrangement of whose parts bears some resemblance to a bridge. A common form is called Wheat stone's bridge, from the inventor. See resistance. Archivolt of a bridge. See archivolt. A es' bridge. pons asinorum. Bottom-road bridge, a bridge whose roadway is supported upon the lower chord in a tru bridge, or at the bottom in a tubular bridge. Also called through bridge. Op See each side of the pivot-pier.- Pontoon bridge, a platform or roadway supported upon pontoons. Bridges of this kind are largely used in military operations, the pontoons being formed of air-tight bags or hollow metallic ve els. - Rope bridge, a hanging bridge consisting of a platform supported by ropes, or simply of a rope carried acro the stream or chasm, and supporting a basket or car which is drawn backward and forward. Such bridges are used in mountainous districts, especially in India and South Amer ica, and are sometimes made of sufficient strength to afford pa age to droves of loaded mules. The ropes are often made of plaited thongs of hide, or even of rushes.Suspension-bridge, a roadway suspended from ropes, chains, or wire cables, usually hung between ma ive towers of masonry, and securely anchored at the extremities. The most notable of suspension-bridges is that between New York and Brooklyn, over the East River. The main span is 1,595 feet long, the altitude at the center 135 feet above mean high water, the height of the towers 2765 feet, and the total length 5,989 feet. The roadway is suspended from four cables of steel wire, each 15 inches in East River Suspension-bridge, New York. bridge diameter. Through bridge. Same as bottom -road bridge: opposed to deck- bridge or top -road bridge. - Top-road bridge, a bridge in which the roadway is upon or above the upper chord of the tru . Also called deck - bridge. Tru ed-arch bridge, an arched-beam bridge with which a tru has been combined to stiffen or strengthen it.Tubular-arch bridge, a bridge in which the primary Tubular-arch Bridge, St. Louis, Mi ouri. supporting members are arched tubes. - Tubular bridge, a bridge forming, as a whole, a great hollow beam. It is a box-beam, sufficiently large to admit of the pa age of vehicles through it. The first works of this kind were the Conway and Britannia railway bridges in Wales. The latter, over the Menai strait, opened in 1850, consists of two independent rectangular tubular beams of wrought iron 1,511 feet long, with a single span of 459 feet. The Victoria tubular bridge over the St. Lawrence at Montreal is about two miles long. Also called box - girder bridge. Wheat stone's bridge. See resistance. 681 Bridge-tower.- Moldau Bridge, Prague, Bohemia. bridgel (brij), v. t.; pret. pret. and pp. bridged, ppr. bridging. [ME. * bryggen (not bridging (not found), = = build a bridge or bri bridge or bridges on or over; span with a bridge: as, to bridge a river.-2. To make a bridge or bridges for. IMG:content-2528.png:[blocks in formation] which lies at our feet. George Eliot. I cannot but think that there is room for all of us to work in helping to bridge over the great aby of ignorance Huxley , Lay Sermons, p. bridge2t, v. t. [Also bredge , briggen , breggen, by apheresis for abriggen , abreggen, mod. E. abridge , q. v.] To shorten; abridge. Byreven man his helthe and his welfare, And his dayes briggen and schorte his lyf. Occleve , MS. Soc. Antiq., 134, fol. 251. ( Hall i well .) bridge-bar (brij'bär), n . In a car-coupling, the bar carrying the load.