II. Mosque of Cordoba. ‘Abd al-Raḥmān I (169/785-786). The Proportional Design of the Plan and Elevation of the Oratory. The 8th-century qibla and miḥrāb

Abstract

The square ground plan of the 8th-century Mosque was divided into two equal rectangles, to form the patio and the oratory. The architect divided the oratory into two squares, took its E. and W. sides as radiuses, and the point where they crossed over gave him the width of the central nave. He divided the remaining areas of each square into five equal parts to obtain the lateral naves. To establish the place of the columns he may have used either a rectangular grid or a rhomboidal grid. With the central axes of the columns known, he elevated the arcades and the ceiling by using a set-square of 90°, 45°, 45° (with hypotenuse √2), and another set-square of 90°, 60°, 30° (with hypotenuse √4). The wall of the qibla ran the length of the 11 naves and contained the niche of the miḥrāb.