. The Canadian journal ; a repertory of industry, science, and art ; and a record of the proceedings of the Canadian Institute. In the annexed diagram, (Fig. 2) the cyhnders are b ; the standard (e e e) having openings to admit the train to pass. On the west standard is a cross girder of wrought-iron (s) upon which the tubes (i) re^t. The tube serves to keep apart and steady the towere; and to the ends of the tube are attached the suspending chains. Xow, in an ordinary suspension bridge, the chains hang in a festoon, and are free to move, according to the limited weights passing under them; bu
. The Canadian journal ; a repertory of industry, science, and art ; and a record of the proceedings of the Canadian Institute. In the annexed diagram, (Fig. 2) the cyhnders are b ; the standard (e e e) having openings to admit the train to pass. On the west standard is a cross girder of wrought-iron (s) upon which the tubes (i) re^t. The tube serves to keep apart and steady the towere; and to the ends of the tube are attached the suspending chains. Xow, in an ordinary suspension bridge, the chains hang in a festoon, and are free to move, according to the limited weights passing under them; but this flexibiUty would be inad- missible in a railway bridge, and the continuity of the rail would be destroyed if a very small deflexion took place when passed over by a hea\"y locomotive. With a view to give this necessaiy rigidity, Mr. Brunei has introduced at every third part of the tube a stiff -m-ought-kon girder, connecting firmly the tube to the roadway girders; and, with the aid of other adjusting screws, the suspension chains are pulled or stretched as nearly straight as desirable. Other diagonal chains connect these points, so that at whatever part of the Bridge an engine may be passing its weight is distributed all over the tube and chains by these arrangements. The tube is laid upon the iron standards, but is free to move upon rollers at the top of the masonry standai'd. The expansion on the hottest day yet experienced has not exceeded one inch. The tube is strengthened within by the inti-oduction of dia- phragms or discs at every 30 feet, which render it both hght and stiff. Tlie roadway girders (d) are fonncd of a deep thin plate of iron, stiffened at inter\als. At the top it has a strong triangular cell to resist compression, and at the bottom a double plate of riveted iron to resist extension. Between these side road girders are small cross girders (k) (Fig. 1) riveted to them diagonally. Ujion the cros,? girdere 4 inch creosoted planks are secured in the
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Keywords: ., bookauthorcanadian, bookcentury1800, bookdecade1850, bookyear1852
