The vault of the Chapel of the Presentation in Burgos cathedral: divine canon? No, cordovan proportion

Resumen

The cordovan proportion was discovered by chance in 1973, during an attempt to demonstrate the validity of the golden ratio in buildings in the city of Cordova. Far from being a local exception, later research have shown its sphere of application to be universal. However, few authors have researched the influence of the Cordovan triangle on the layout of architectural elements, and particularly on octagonal gothic vaults. The present paper presents an analysis of the Cordovan proportion in the curved ribbing of gothic vaults. Specifically, it consists of a geometric study of the octagonal vault of the Chapel of the Presentation in Burgos Cathedral. The results show that when the side of the octagon is taken as a modulus, the Cordovan triangles drawn by the layout of the vault form a geometric succession whose ratio is the Cordovan number.