APPLICATIONS OF TIMBER. 193 



(le£^ee of skill, in balaiicina: strains a<;ainst each other, 

 so as to insure botli steadiness aiul strcn<>;th. The 

 principal fault in this celebrated bridp;e consisted in 

 many of the timbers bein<;- of o-reat lenc;tli, so as 

 not to admit of beiui;- easily replaced in case of 

 decay. It was burned down by the French army in 

 tlie year 1799 ; and has since been replaced by a more 

 sini])le wooden bridi;e, in wliich the water-way is di- 

 vided into tluee i)arts by two piers, and the road is 

 said to be wider and more convenient. 



Several otlier wooden l)rids;es \\ ere constructed by 

 Ulric Cirubenman, by his brother Jolin, or by the 

 two tot!,ether. Of these, John built a brid|j;e over 

 tlie Rhine, near Jliclienau, of two hundred and 

 forty feet span ; and the two brothers erected another 

 of two lumdred feet across the Limmat, near Baden. 

 Both these bridges resembled, in their general 

 framina;, the bridge at Scliatfhausen. Ulric, however, 

 constructed one somewhat diti'erently ; it was two 

 lumdred and tliirty feet span. In this bridge there 

 were no diverging braces. The abutments were 

 twenty-five feet high, and theaix-h between them was 

 a catenary, — that is, the same ibrm which a rope or 

 flexible chain assumes by its own weight, when hung 

 over two fixed pegs. This arch was of course in- 

 verted, in the same manner as the iron chain bridges 

 that have recently been constructed in this country ; 

 and making allowance for the ditlerence of materials, 

 and the mode of the junction, it may be tair perhaps 

 to consider it as the tirst chain bridge that ever was 

 constructed in Europe. The two catenarian arclies 

 iVom wiiich the roadway was suspended were formed 

 of beams of oak, in lengths of Irom twelve to fourteen 

 feet ; there were seven thicknesses of them above 

 each other, and they were so contrived as to break 

 bond like masonry, so that there should never be two 

 vertical joints in the same section, and they were 

 strongly bolted and bonded together. Probably for 



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