Chap. VI.
FRANCE.
253
on sledges with low wheels, heavy contributions being laid on the merchants by those inte-rested in the continuance of this manoeuvre, so injurious to commerce, and who contrivedto make the public believe that it was necessary for the preservation of the bridge.
It being, however, perceived that the masonry of the arches was as solid as possible, andthat no inconvenience could arise by letting the heaviest waggons proceed, spaces wereformed over the piers to permit them to pass easily, the pavement of the bridge was relieved,where it lay immediately over the vaults they were covered by a thick bed of gravel, andthe bridge is now perfectly free, without any injury having been sustained.
Bridge of Ceret , on the Tech, was built in 1336, on the road from Perpignan to Pratzde Mouillon. It consists of a single semicircular arch, 147 feet 8 inches span, of squaredstone, the remainder is of brick. It is remarkable for the arches in the haunches andabutments, which are from 23 to 26 feet span. This bridge is in good preservation : it isonly 12 feet 9 inches wide.
Bridge of CasteUane, on the Verdon, near Sisteron ; its arch is a segment of a circle, whosechord is 115 feet, and its versed sine 28 feet 9 inches. It was built in 1404, from the pro-duce of indulgences granted by the pope. Its breadth is 6 feet 6 inches, and it is foundedon a rock.
Bridge on the Isere consists of four arches, from TO feet 2 inches to 91 feet 6 inchesspan. The arches are segments of circles, and the piers which support them are very thick,being 30 feet. The breadth of the bridge is 19 feet 8 inches, it is almost entirely ofrubble work.
Bridge of Villeneuve (TAgen on the Lot. This bridge, of about the same date as thepreceding, consists of a great semicircular arch 114 feet 9 inches span, two others from 29feet 6 inches to 32 feet 9 inches, and a smaller one of 5 feet 11 inches. The upper part ofthe great arch is in a bad state, and tends to separate in several places, but as it is tiedtogether by iron rods uniting two iron arches, one on each side, it may still last for sometime.
Bridge of Vieille Brioude on the Allier , situated near the Roman bridge, was built in 1454,by the contractors Grenier and Estone, at the expense of a lady of the place. It consistsof a single arch, the segment of a circle, 133 feet 4 inches span, and 70 feet 4 inches versedsine. This is the largest arch existing in France , and probably in Europe ; it is 16 feetwide, as are the abutments on which it rests ; it is formed of 2 and 3 rows of voussoirs,placed one upon the other without any tie, one is of volcanic stone, and the other of veryhard sandstone. The stones are only from 8 to 9 inches thick, by 2 feet 2 inches long.The whole thickness of the circle is 7 feet 5 inches. The bridge is founded on two rocksrising above low water ; its great height and its small width, the steepness of the roads cutin the rock by which it is approached, as well as some settlements which induced fears forits solidity, have caused the road to be turned, and another bridge constructed half aleague lower, at Bajace ; this w’as begun in 1750, consisting of three flat arches, rising onethird, from 70 feet 3 inches to 76 feet 8 inches span, with abutments 18 feet, and piers 13feet 8 inches thick, and was finished in 1753. The foundations were on piles. The greatarch was 4 feet 9 inches thick, but being, -with the exception of the face, constructed ofsoft stone, which requires a long exposure to the air in order to harden, it cracked directlythe centres were removed in the upper part, and fell as far as the twelfth or thirteenthrow of voussoirs from the springing, the faces being drawn with it by their connection withthe rest of the arch. One of the small arches was, however, finished, the attendant pierserving as an abutment until the following year, when the great arch was reconstructedwith better materials, and made 3 feet 3 inches thick.
The soil on which this bridge stands is a compact gravel, into which the pilesare driven with difficulty, yet liable to be carried away by the current; it was attemptedto prevent this by constructing above a coffer of piles, between which all the gravel wasdredged, and its place filled with rubble work. Notwithstanding this precaution the bridgewas carried away by a flood, and as the abutments still remain, it is proposed to reconstructit by raising a single pier, and founding it in a caissoon.
Bridge of Sisteron , on the Durance, was constructed in 1500, and is remarkable fromhaving an arch 85 feet 4 inches span, of an elongated, elliptical form, 57 feet 5 inches inheight. It is probable that it was at first pointed, and that the angle at the two arcs wasafterwards rounded, which conjecture is further strengthened by the circumstance of theupper and lower parts of the arch being of a different construction.
Bridge of Tournou , on the Daux, built by an Italian engineer in 1545, at the expense ofsome cardinal. It has one great segmental arch 156 feet 10 inches span, built like thebridge of Vieille Brioude, on rock, and only 16 feet 5 inches wide; it is constructed ofpieces of soft, dressed sandstone, except the faces, w'hich are of squared stone. Theremaining portion is of rough rubble.
Bridge of Claix , on the Draie, consists of a single arch, the segment of a circle, 150 feet3 inches span; its breadth is 20 feet 4 inches; it was constructed in 1611, near Grenoble ,by the constable Lesdiguieres . It is a subject of much admiration with the historians of