334 Transactions of the Ajserican Institute. 



Though this bridge has no great span, it is to be regai'ded as the 

 best and most complete, in point of principle, of all existing sus- 

 pension bridges. I therefore believe it is an act of justice to give 

 a man of the originality of Mr. Schnirch the honor which he has a 

 right to claim. 



During this time the American engineers, occupied in improving 

 the wooden truss bridges, did not forget to appreciate suspension 

 bridges, and that they constructed the greatest spans, is well 

 known. I mention the former Niagara bridge, of one thousand and 

 forty-two feet span; Ellet's Niagara bridge, of seven hundred and 

 sixty feet, and the unfortunate Ohio bridge at Wheeling, of one 

 thousand and ten feet span. The latter, without any kind of 

 stiffening, succumbed to a heavy hurricane in the year 1854. Stays 

 would not have prevented this accident, for, under the same cir- 

 cumstances, stays were rejected at an early day of this century. 



At the time when the Britannia tubular bridge was to be built, 

 E. Stephenson proposed a stiff suspension bridge, in form of an 

 h'on tube, suspended by chains. Many and costly models were 

 built, as at this time no theories existed, either of truss or suspen- 

 sion bridges. The tubes in these models were made stronger and 

 stronger after every experiment; and, lastly, the chains were no 

 longer necessary, and were dispensed with, and the iron tubular 

 bridge was the result. 



It is plain that the Niagara railroad bridge is the direct applica- 

 cation of Stephenson's plan. 



This work, as well as the Cincinnati bridge, are sufficiently 

 known, and therefore I do not consider it to be necessary to describe 

 them, nor to demonstrate that they are to be appreciated its great 

 works of American enterprise and boldness. 



Before finishing this short sketch of the history of suspension 

 bridges, I have still to mention that the third possible arrangement 

 to stiffen a suspension bridge M^as carried out in London in the year 

 1862 by the engineer Barlow, who bridged the Thames by three 

 single spans, of two hundred and eighty feet each. This work is 

 named the Lambeth bridge. 



The said system consists of cables, horizontal beams and uprights, 

 with diagonals between the cables and beams, so that these repre- 

 sent the chords of the truss work. This arrangement is the most 

 objectionable of the three possible manners of stiffening suspension 

 bridges. 



The detailed construction, as furnished by Bai-low, is unnecessa- 



