470 REVIEWS — REPORT ON VICTORIA BRIDGE". 



For further details on this subject, I beg to refer you to the Report made by Mr. 

 Ross and myself or. the 6th of June, 1853, to the Honorable the Board of Railway 

 Commissioners, Quebec." 



We have not at hand the repoi't referred to, but in his report of 3rd 

 November Mr. Ross goes over the reasons which influenced him in 

 deciding on the dimensions of the abutments, and justifies the manner 

 of their construction. He says of them : 



"These it appears, are considered unnecessarily large, and more costly than the 

 tubes, and it is suggested that they may be reduced by making openings in, or by 

 shortening them. These abutments are not in reality what, upon paper, they appear 

 to be, a solid mass of masonry: they are hollow — each having eight openings or 

 cells, 48 feet in length, and 24 feet in width, separated by cross walls five feet in 

 thickness. The flank wall on the down stream side rising nearly perpendicular, is 

 seven feet in thickness, and that on the upper stream side is sloping from its founda- 

 tion upwards to an angle of 45° : its thickness is twelve feet, and presents a smooth 

 surface to facilitate the operations of the ice, on which account its form had thus 

 been determined; and to ensure greater resistance to the pressure of the ice, the 

 ceils are filled up with earth, stone and gravel, so that one solid mass is thus ob- 

 tained at a moderate cost. The subjoined plan and section of this work will better 

 explain its form and proportions. 



The idea of introducing any other description into the abutments than those 

 described, is altogether inadmissible ; passages through it where ice could accumu- 

 late, would ensure its inevitable destruction upon the first hydraulic pressure it had 

 to encounter. 



I have observed in this immediate neighborhood the effects of swift currents 

 ereited by obstructions in the river on a recently formed causeway constructed of 

 timber connecting a small island below the bridge with the shore, having openings 

 about 12 feet in width at intervals of about 30 feet. 



In the autumn of last yea r , these openings were partly covered by heavy tim- 

 ber and planking strongly secure! by iron work, and the consequence has been, that 

 during last winter, the first crush of the ice, in forcing its passage through, destroyed 

 every timber, plank, and bolt, that opposed it — having got under, it was imme- 

 diately blocked up, and the pressure of water still forcing its way, the jam became 

 at length so tight, that it burst with an explosion. 



It is stated that the length of the abutments is unnecessary and greatly in excess. 

 Upon paper this may seem so, and a recollection of the idea conveyed to my own 

 mind subsequent to the earlier considerations of this subject which led me to the 

 conclusion of adopting their dimensions, prevents my attaching so much importance 

 to such a view as I otherwise might do. You will recollect that the bridge is ap- 

 proached from the north shore by an embankment 1200 feet, and from the south 

 shore 800 feet in length, the river being thereby narrowed to this extent ; the waters 

 thus far embayed, have now to find their way through the bridge, and the 

 current, overcharged with ice, sweeping its way along the front of the embankment 

 into the nearest passage, attains, ere reaching it, a velocity which nothing but the 

 most substantial masonry could resist. This, it will be seen, bears on the question 

 of the length to which such masonry should extend, and I am more than ever con- 

 vinced that I have not exceeded the limits which prudence dictates — thus confirm- 

 ing my original view in reference to this particular and very important point. I 



