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Figure 5: (left) Polonceau 1839; (center, right) Flying buttress and rose window; (Viollet-le-Duc 1854-1868)  the larger arch, with the area below left hollow and merely covered with a protective front wall, Turriano em- phasized that the smaller arch makes the bridge stronger: “this small arch is of strong force for the two large! arches” (Turriano 1984, p. 506; see also p. 502). Turriano also believed that the link between the larger arches made by the smaller arch benefited from the weight of the stone above the smaller arch: “this will put to work what appears to be of no use; because the smaller arch...is of great value in that location with the use of those materials” that sit upon it (Turriano 1984, p. 506, fol. 376r.). From this account, it would appear that Turri- ano considered such an arrangement, like the rounded cutwater, as “self-strengthening.” Note that similar di- minutive connecting arches can be found in eighteenth-century bridge design, as over voids in the repair of Westminster Bridge in 1748 (Ruddock 1979, pp. 16-17). Robert Mylne’s explanation of his design of 1759 fol Blackfriars Bridge articulates the need for such bracing elements, which he provided in the form of a connect- ing flat arch. Mylne understood the small connecting arches as relieving the thrust from the main arches against their haunches and the piers: “the weakness is, that the middle part of the [large] arch makes a latera pressure against the haunches of it.” Ted Ruddock explains, “the horizontal course of hewn stone from haunck to haunch would certainly have performed this function [i.e., “carrying the horizontal thrust from haunch te haunch”] and thus relieved the piers of nearly all horizontal thrust...."" Jonn Rennie “always made an invertec arch of hewn stone to carry the thrust from one main arch to the next” in his multi-arch bridges (RUddock 1979. pp. 67-68, 147, 183). It would seem that the weighted connecting arch in Turriano’s design was intended tc serve the same purpose. As for the hollowing under the small arches. Turriano appears to utilize the advantage of providing a clear path for loads according to consistent stresses, a principle exemplified by the engineel Curt Siegel’s account of Pier Luigi Nervi’s design for the Municipal Stadium (Florence, 1929-1932) where Nerv created a hollow frame in a V-support so that “the bending moment is then resolved into a couple and the structure is resolved into clearly defined tension and compression members” (Siegel 1962, p. 134).

Figure 5 (left) Polonceau 1839; (center, right) Flying buttress and rose window; (Viollet-le-Duc 1854-1868) the larger arch, with the area below left hollow and merely covered with a protective front wall, Turriano em- phasized that the smaller arch makes the bridge stronger: “this small arch is of strong force for the two large! arches” (Turriano 1984, p. 506; see also p. 502). Turriano also believed that the link between the larger arches made by the smaller arch benefited from the weight of the stone above the smaller arch: “this will put to work what appears to be of no use; because the smaller arch...is of great value in that location with the use of those materials” that sit upon it (Turriano 1984, p. 506, fol. 376r.). From this account, it would appear that Turri- ano considered such an arrangement, like the rounded cutwater, as “self-strengthening.” Note that similar di- minutive connecting arches can be found in eighteenth-century bridge design, as over voids in the repair of Westminster Bridge in 1748 (Ruddock 1979, pp. 16-17). Robert Mylne’s explanation of his design of 1759 fol Blackfriars Bridge articulates the need for such bracing elements, which he provided in the form of a connect- ing flat arch. Mylne understood the small connecting arches as relieving the thrust from the main arches against their haunches and the piers: “the weakness is, that the middle part of the [large] arch makes a latera pressure against the haunches of it.” Ted Ruddock explains, “the horizontal course of hewn stone from haunck to haunch would certainly have performed this function [i.e., “carrying the horizontal thrust from haunch te haunch”] and thus relieved the piers of nearly all horizontal thrust...."" Jonn Rennie “always made an invertec arch of hewn stone to carry the thrust from one main arch to the next” in his multi-arch bridges (RUddock 1979. pp. 67-68, 147, 183). It would seem that the weighted connecting arch in Turriano’s design was intended tc serve the same purpose. As for the hollowing under the small arches. Turriano appears to utilize the advantage of providing a clear path for loads according to consistent stresses, a principle exemplified by the engineel Curt Siegel’s account of Pier Luigi Nervi’s design for the Municipal Stadium (Florence, 1929-1932) where Nerv created a hollow frame in a V-support so that “the bending moment is then resolved into a couple and the structure is resolved into clearly defined tension and compression members” (Siegel 1962, p. 134).