Chap. VIII.

BRITAIN.

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roadway; there can be no doubt, however, that it would have been better to have omittedthe columns altogether, as they can hardly be supposed fit decorations for the piers of abridge.

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Bridge over the River Cree at Newton Stewart , executedalso by Mr. Rennie, consists of five arches, all segmentsof circles ; that in the middle is 50 feet span, with aversed sine of 6 feet 6 inches, its two piers are 8 feet inthickness; the arch on each side of the centre is 46 feetspan, with a versed sine of 2 feet 9 inches, and the outerpiers are diminished in width 6 inches ; the two archeson the land sides are 39 feet in width, with a versed sineof 4 feet 9 inches.

The roadway, which takes the same curve as the cor-nice of the bridge, is 20 feet in width between the para-pets.

Bridge over the Esk at Musselburgh was also con-structed from designs by Mr. Rennie, about the year1803. It consists of five segmental arches of considera-ble radii; that in the middle is 45 feet span, with aversed sine of 6 feet 6 inches ; the arches on each side ofthe centre are 42 feet span, with a versed sine of 5 feet ;the outer arches, or those adjoining the abutments, are37 feet span, with a versed sine of 3 feet. The piersare all 7 feet in width above the set-off, and are rusticatedto the underside of the cornice, which has a circular form,and follows the curvature of the road.

In the bridges over the Cree and Esk the flat seg-mental arches produce the most elegant and pleasingeffect. Ammanati, in his beautiful design executed atFlorence (Fig. 184.), had already shown how muchgrace could be obtained by the introduction of archesthat approached the elliptical form. Perronet, someyears afterwards, also with great success, adopted otherswhich formed a portion of the circle, or were very flatcurves. St. Maxence on the Oise (Fig. 280.), andBrunoi on the Ilyeres (Fig. 282.), executed by thatcelebrated engineer, served as models for many ex-ecuted in France ; among which may be reckonedthat of Jena at Paris , erected in 1808 by Lamande(Fig. 288.); but all these bridges, though their archesare of an increased span, and of bolder construction, donot surpass the examples we arc describing. The cur-vature given to the roadway, to accommodate the levelof the banks of the river, differs from the French ex-amples, but is admirably accomplished in the Kelsobridge, where the effect is improved by the cornice beingmaintained horizontally throughout. The enormoussums of money that have recently been expended tolower the crowns of Westminster and Blackfriarsbridges, so as to render the draught over them lesslaborious, ought to satisfy those who are partial to acurved line of road, that utility and elegance equallyrecommend its discontinuance; and that, wherever alevel surface can be obtained, without too much increas-ing the expense of the abutments, it should be adopted.Independent of this the eye is better satisfied with suchan arrangement, as the ends of the bridge, where all thestrength is required, gain importance by elevating itabove the ordinary level of the shore, and an idea isconveyed of power to resist the combined thrust of thearches, by the additional loading it receives from theincrease of height. A reference to Waterloo Bridgewill convince the most fastidious that the level line notonly possesses the greatest convenience, but beauty also ;the latter arising out of the fitness of the several partsfor the uses to which they are devoted.

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