322 Transactions of the American Institute. 



their speed. Ten chains, each five hundred and seventy-six feet 

 long, were made to bear five hundred tons with perfect security. 

 Three of the chains were fastened on each side of the bridge, and 

 four in the middle. "The railing was stout and strong," a con- 

 struction, which " contributed much to the stifihess of the floor." 

 Thomas Pope himself calls it a wonderful structure, describes the 

 railing as contributing much to the stifihess of the floor, and states 

 that Templeman's talents and improvements had earned for him a 

 great reputation as engineer of such work. He also reported that 

 the motion of the floor of the Merrimac bridge was " very little per- 

 ceptible, whatever the speed of any kind of traflSc." 



The bridge across the Lehigh, built in the year 1815, near North- 

 ampton, in Pennsylvania, consisting of two whole and two half 

 spans four hundred and seventy-five feet long, bearing two tracks 

 for carriages and two six-feet wide footpaths, Wiis the first mentioned 

 suspension bridge of more than one span. 



The application of wire for suspension bridges is also an Ameri- 

 can invention, for the first wire bridge was built before the 

 year 1808, at Philadelphia, across the Schuylkill river, with a span 

 of four hundred and eight feet. I found in the book on wire 

 bridges, by the French engineer, Seguin, published in the year 

 1824, that a report on the American canals, written by Mr. Galla- 

 tin, in the year 1808, and copied in a French book from the year 

 1820, mentioned the wire bridge at Philadelphia. The same bridge 

 is also described in the " Bulletin de la Soci6t6 d'Encouragement," 

 in the year 1816, 



According to these notices, the existence of the American wire 

 suspension bridge was well known in Europe a long time before 

 the first regular suspension bridge was built there. 



Pope's book was well known in France, and Seguin, as well as 

 the famous French engineer, Navicr, made use of it. Finley's 

 important invention, in connection with Templeman's improvements, 

 as well as Pope's book, and the wire bridges built in this country, 

 were known in England by Samuel Brown and others in the year 

 1814, and it is most probable were known in France, for the 

 brothers Seguin, French engineers, seem to have been in England, 

 and Navier especially was sent there to study suspension bridges. 



At that time a Frenchman of the name of Poyet, proposed a kind 

 of stay bridges, consisting of high wooden masts iis towers, from 

 the tops of which were starting many stays to both sides support- 

 ing the floor. 



