EE VIEWS — BEPOBT ON VICTOEIA BEIDGE. 481 



letter, that I can add no further remark upon the subject, except perhaps that 

 there appears to be a discrepancy in that part which relates to cost. 



In dividing the £80,000 into items, Mr. R033 has deducted £20,000 for mason- 

 ry, and left the residue, £60,000, for the 800 feet of roadway. Now it appears 

 evident that this amount should include the cost of the "land chains;" and assu- 

 ming their value at about £15,000, there would be only £45,000 left for the 800 

 feet of roadway, thus reducing the cost per lineal foot to about that of the tube. 

 But in the application of a suspension bridge for the St. Lawrence the item 

 £15,000 for "land chains" would of course have to be added to the cost of the 

 7,000 feet of roadway, which would swell the amount per foot to a little over 

 that of the tubes." 



********* 



" I entirely concur in what Mr. Ross says respecting the propriety or applying 

 the suspension principle to the passage across the Niagara gorge ; no system of 

 bridge building yet devised could cope with the large span of 800 feet which 

 was then absolutely called for, irrespective of the other difficulties attended to. 



" Where such spans are demanded, no design of beam with which I am ac- 

 quainted would be at all feasible. The tube, trellis, and triangular systems are 

 impracticable in a commercial sense and even as a practical engineering question 

 the difficulties involved are all but insurmountable. 



"Over the St. Lawrence we are fortunately not compelled to adopt very large 

 spans, none so large ia fact as have been already accomplished by the simple 

 ' Girder' system It i3 under these circumstances that the suspension principle 

 fails, in my opinion, to possess any decided advantage in point of expense, whilst 

 it is certainly much inferior as regards stability for railway purposes. The flexure 

 of the Niagara Bridge, though really small, is sufficiently indicative of such a 

 movement amongst the parts of the platform as cannot fail to augment where 

 wood is employed, before a long time elapses. 



44 1 beg that this observation may not be considered as being made in the tone 

 of disparagement; on the contrary, no one appreciates more than I do the skill 

 and science displayed by Mr. Roebling in overcoming the striking enginnering 

 difficulties by which he was surrounded; I only refer to the question of flexure in 

 the pktform as an unavoidable defect in the suspension principle, which from the 

 comparatively small spans that are available in the Victoria Bridge may be en- 

 tirely removed out of consideration." 



It may be questioned whether the circumstances of the railway 

 traffic demanded the immediate construction of a railway bridge at 

 Montreal of any description, but it i3 not our purpose to discuss 

 that question here. We feel confident, however, that the exceed- 

 ingly expensive structure now being erected cannot be justified 

 while a much less costly one was within reach. "While fully admit- 

 ting the force of all Mr. Stephenson's arguments in favour of the 

 tubular principle, as in comparison with other principles of construc- 

 tion in iron, and as compared with the suspension principle for the 

 particular case in question, we regret that he did not more fully 

 consider the fitness of a wooden superstructure, which we feel con- 



