082 



MIDGE B1UEF. 



circumstances, extremely difficult, owing to the fact, 

 that the strength of materials does not inert ;IM- in pro- 

 portion to their weight, anil that there are limits, 

 beyond which no structure of tin- kind (!ould be car- 

 ried, anil withstand its own gravity. Bridges differ 

 in their construction, and in tin- materials of which 

 they are composed. The principal varieties are the 

 following: I. /fboden briilges. These, when built 

 over shallow and sluggish streams, are usually sup- 

 ported upon piles drixen into the mud at short dis- 

 tances, or upon frames of timber. But, in deep and 

 powerful currents, it is necessary to support them on 

 strong stone piers and abutments, built at as great a 

 dis;;n'ice as practicable from each other. The bridge, 

 between these piers, consists of a stiff frame of car- 

 pentry, so constructed, with reference to its material, 

 i hat it may act as one piece, and may not bend, or 

 break, with its own weight and any additional load to 

 which it may be exposed. When this frame is 

 straight, the upper part is compressed by the weight 

 of the whole, while the lower part is extended, like 

 the tie-beam of a roof. But the strongest wooden 

 Itridg-es are made with curved ribs, which rise above 

 the abutments in the manner of an arch, and are not 

 subjected to a longitudinal strain by extension. These 

 ribs are commonly connected and strengthened with 

 diagonal braces, keys, bolts, and straps of iron. The 

 flooring of the bridge may be either laid above them 

 <>r suspended by trussing underneath them. Wooden 

 bridges are common in this country, and some of 

 them are of large size. One of the most remarkable 

 is the upper Schuylkill bridge at Philadelphia, already 

 mentioned. 2. Stone bridges. These, for the most part, 

 consist of regular arches, built upon stone constructed 

 in the water, or upon abutments at the banks. Above 

 the arches is made a level or sloping road. From the 

 the nature of the material, these are the most durable 

 kind of bridges, and many are now standing, which 

 were built by the ancient Romans. The stone piers, 

 on which bridges are supported, require to be of great 

 solidity, especially when exposed to rapid currents, or 

 floating ice. Piers are usually built with their greatest 

 length in the direction of the stream, and with their ex- 

 tremities pointed or curved, so as to divide the water, 

 and allow it to glide easily past them. In building 

 piers, it is often necessary to exclude the water by 

 means of a coffer- dam. This is a temporary en- 

 closure, formed by a double wall of piles and planks, 

 having their interval filled with clay. The interior 

 space is made dry by pumping, and Kept so till the 

 structure is finished. 3. Cast-iron bridges. These 

 have been constructed in Britain, out of blocks or 

 frames of cast-iron, so shaped as to fit into each other, 

 and, collectively, to form ribs and arches. These 

 bridges possess great strength, but are liable to be 

 disturbed by the expansion and contraction of the 

 metal with heat and cold. 4. Suspension bridges. 

 In these the flooring or main body of the bridge is 

 supported on strong iron chains or rods, hanging, in 

 the form of an inverted arch, from one point of sup- 

 port to another. The points of support are the tops 

 of strong pillars or small towers, erected for the pur- 

 pose. Over these pillars the chain passes, and is 

 attached, at each extremity of the bridge, to rocks or 

 massive frames of iron, firmly secured under ground. 

 The great advantage of suspension bridges consists 

 in their stability ot equilibrium, in consequence of 

 which a smaller amount of materials is necessary for 

 their construction than for that of any other bridge. 

 If a suspension bridge be shaken, or thrown out of 

 equilibrium, it returns by its weight to its proper 

 place, whereas the reverse happens in bridges which 

 are built above the level of their supporters. 5. 

 Floating bridges. Upon deep and sluggish water, 

 stationary rafts of timber are sometimes employed, 



extending from one shore to nnotlier, find covered 

 with planks, so as to form a passable bridge. In 

 military operations, temporary bridges are often 

 formed by planks laid upon boats, pontoons, and other 

 buoyant supporters. 



BRIDGKTOWN ; a seaport town, and capital of the 

 island of Barbadoes, in the West Indies, lying in the 

 S. \V. part, and in the parish of St Michael! Lon. 

 59 4<y W. ; lat. 13 5' N. Population, 15 or 20,000. 

 It is situated on the innermost part of Carlisle bay, 

 which is large enough to contain 500 ships, being 

 four miles in breadth, and three in depth ; but the 

 bottom is foul, and apt to cut the cables. It suffered 

 greatly by fire, on Feb. 8, 1756, May 14, 1766, and 

 Dec. 27, 1767, when the greatest part of the town 

 was destroyed ; before which time, it had about 1500 

 houses, mostly brick, very elegant, and said to be the 

 finest and largest in all the Caribbee islands, the great- 

 est part of which have been rebuilt. It has a college, 

 founded liberally, and endowed by colonel Codring- 

 ton. Here are commodious wharves for loading and 

 unloading goods, with some forts and castles. The 

 town is subject to hurricanes. On the east side of the 

 town is a small fort of eight guns, where the maga- 

 zines of powder and stores are kept under a strong 

 guard. This is the seat of the governor, council, as- 

 sembly, and court of chancery. 



BRIDGEWATER; a borough town in the county of 

 Somerset, England, on the Parrel, over which is an 

 iron bridge. Although the town is twelve miles from 

 the sea, the tide rises *ix fathoms at high water, and 

 flows in with such impetuosity as frequently to injure 

 the shipping. This rapid motion is called the bore, 

 and is not uncommon in the rivers which flow into 

 the Bristol channel, (q. v.) It has little coasting, but 

 considerable foreign trade. In the castle built by 

 king John, the duke of Monmouth lodged, and was 

 here proclaimed king, in 1685, before the battle of 

 Sedgemoor, which was fought about" three miles from 

 the town. B. then became the theatre of Feversham's 

 and Jefieries' barbarity. Population in 1831, 7807. 



BRIDGEWATER CANAL. See Canal. 



BRIDLE ; the headstall, bit, and reins, by which a 

 horse is governed. The origin of it is of high anti- 

 quity. The first horsemen guided their horses witli a 

 little stick, and the sound of their voice. A cord 

 drawn through the nose is sometimes used for other 

 animals. The ancient Thessalian coins often repre- 

 sent a horse with a long rein trailing on the ground. 

 The Romans were trained to fight without bridles, as 

 an exercise in the manege. On Trajan's column, 

 soldiers are thus represented at full speed. The 

 parts of a modern bridle are the snaffle or bit ; the 

 headstall, or leathers from the top of the head to the, 

 rings of the bit ; the fillet, over the forehead, and un- 

 der the fore-top ; the throat band, which buttons 

 under the throat ; the reins ; the nose-band, buckled 

 under the cheeks ; the trench, the cavesan, the mar- 

 tingal, and the chaff-halter. 



BRIEF, from the French bref, which comes from the 

 Latin brevis, denotes a thing of short extent or dura- 

 tion. It is more particularly used for a summary or 

 short statement. 



Brief, in law, signifies an abridgment of the client's 

 case, made out for the instruction of counsel on a 

 trial. In this, the case of the party is to be concisely 

 but fully stated ; the proofs are to be placed in dun 

 order, and proper answers made to whatever may be 

 objected against the cause of the client. In preparing 

 the brief, great care is requisite, that no omission be 

 made which may endanger the case. 



Briefs, apostolical, written messages o the pope, 

 addressed to princes or magistrates, respecting mat- 

 ters of public concern. Such brevia as are despatched 

 .by the datarii or secretarii, and called rescripts, dee- 



