THE 



QUARTERLY JOURNAL, 



April, 1823. 



Art, I. On the Curvature of the Arches of the Bridge of 

 the Holy Trinity at Florence. By Samuel Ware, 

 Esq. 



\To the Editor o/ Me Quarterly Journal of Science andtheArts.] 



1 O determine the curvature of the arches of the marble * 

 bridge of the Most Holy Trinity erected over the Arno at 

 Florence by Bartolommeo Ammanati, is a problem which still 

 occupies the attention of antiquaries, mathematicians, and ar- 

 chitects. Some account of the interest this question has ex- 

 cited, will be found in Ferroni's tract entitled " Delia vera curva 

 degli archi del Ponte a S. Trinit^ di Firenze ; discorso geome- 

 trico-storico," inserted in the 14th vol. of the Transactions of 

 the Society Italiana delle Scienze. 



When it is observed, that the curvature of these arches affords 

 the flattest roadway, and the greatest waterway, with the 

 smallest quantity of material of any stone bridge ever con- 

 structed, and taking into consideration that cast-iron is ten 

 times stronger than marble, and twelve times stronger than 

 common stone in compression, and that the vault of this bridge 



* This bridge is only faced with marble, the vault between the faces is 

 built with ordinary stone, coarsely wrought, but bonded at intervals froiii 

 face to face, by stone of a belter sort properly worked. 



Vol. XV. B 



