1836.] Miscellaneous. 3 1 9 



feet in width, and its thickness is about 20 feet; although the largest blocks of 

 the hard limestone of Jura were employed in this work, iron cramps were used 

 to complete the union of the stones, and above 24 tons of iron were used for 

 this purpose. 



The width of the valley of the Sarine at the point where the bridge is built, 

 or, in other words, the distance between the inner face-work of the two gate- 

 ways on either bank of the river, and consequently the span of the suspended 

 roadway, is 871 feet. It may be easily conceived that a good deal of doubt was 

 entertained as to the propriety of trusting to a span of so great an extent, and the 

 idea of suspending the bridge at the middle at first occurred to M. Challey as 

 the best mode of forming the communication. On weighing the difficulty, how- 

 ever, of obtaining a solid foundation for a pier 220 feet in height in the bottom 

 of an alluvial valley, he soon relinquished this idea ; and the bridge has there- 

 fore been constructed with a single span of 871 feet. 



The roadway is suspended in the manner now universally known, by four 

 cables of iron wire* passing over the upper part of the gateways. Each cable 

 consists of 1200 wires, each about ^ inch in diameter, and 1140 feet in length. 

 To avoid the difficulty of moving these heavy cables, each wire was brought 

 separately to its place, and they were united on the spot by the workmen, who 

 were suspended during the work. We are happy to add, that no accident of 

 any kind occurred during this operation. It is calculated that the four united 

 cables are capable of sustaining a weight equal to 2946 tons. 



The four cables are fixed in chain-pits or shafts cut out of the solid rock on 

 either side of the river. In each of these pits four cables pass through a verti- 

 cal cylindric chimney or pillar, which bears three heavy domes resting upon it, 

 and at the same time abutting against grooves cut with much care in the rock 

 to receive the springing stones. At the bottom of the pillars the cables are 

 made fast to blocks of very hard stone, which are cubes of Cf feet. The cables, 

 therefore, cannot slide without lifting the whole of these enormous buildings, 

 strengthened as they are by their connexion with the solid rock. 



M. Challey began this work in the spring of 1832. He brought out of 

 France, we think, only a foreman who had assisted him on former occasions, and 

 engaging in this arduous enterprise with the inexperienced workmen of the country^ 

 who had never seen a suspension bridge, he completed the workin spite of all these 

 difficulties ; and on the loth October 1834, fifteen pieces of artillery drawn by 

 forty-two horses, and surrounded by 300 persons, crossed the bridge through ; 

 they united in one body as well on the middle as at the ends of the roadway. 

 Nor was the least appearance of derangement of the structure discovered on the 

 closest examination. Some days after the whole inhabitants of Fribourg and its 

 suburbs passed over in procession, so that there were no fewer than 1800 per- 

 sons on the bridge at the same time ; and all classes of travellers, mercantile 

 and curious, have since united with the natives of the Swiss cantons in testify- 

 ing their entire satisfaction with the bridge. Although the severe proof to which 

 constructor of this work subjected it, by loading the roadway with about 20 lbs. 

 on each square foot, did not take place till the month of October 1835, yet it 

 may safely be said that the colossal bridge of Fribourg was completely finished 

 in two years and a half. The whole expense was only about ^.24,000. 



The only bridge which can be compared for its dimensions with that of M. 

 Challey is the Menai or Bangor bridge, which joins the Isle of Anglesea to 

 the main land of England. The largest vessels sail below it with full canvass 

 «et. It was constructed by the celebrated Engineer Telford ; but the Menai 

 bridge is only 550 feet in length, while the bridge of Fribourg is 871 feet. The 

 roadway of Mr. Telford's bridge is about 106 feet above the level of high 

 water, and M. Challey's 167 feet above the level of the river Sarine. 



* It is not perhaps generally known that in all the suspension bridges in France 

 ropes formed of wires are employed, instead of the solid links used in England. 



-f- This remark reminds us of the Sagur bridge built by Col. Presgrave under diffi- 

 culties so much superior. — See vol. II. p. 538. — Ed. 



