[113] Springing. The plane of demarcation between the ring and the abutment is called the “springing” of an arch. A “ring” is the compressed arc of materials known as archstones or voussoirs; and the “springing” marks the place where a ring starts out on its upward curve from a pier or from an abutment.
[114] The haunches of an arch are those parts that lie midway between the springing and the crown: the crown being the summit of a ring.
[115] “The Builder,” November 19, 1892, p. 394.
[116] “The Builder,” November 19, 1892, p. 394.
[117] If Cæsar’s bones were found they would be sold at Christie’s to a tradesman millionaire.
[118] Lord Curzon’s “Persia and the Persian Question,” 1892, Vol. II, pp. 45-6.
[119] According to some writers, the earliest known arches of handicraft—pointed, and round, and even elliptical—are Babylonian, but I do not care to be so dogmatic. Dates very often are as elusive as dreams. But the influence of Babylon was, doubtless, very great on the traditions of the building arts; perhaps we find it even in the elliptic vault of Chosroes’ great hall at Selucia-Ctesiphon. This vault, dating from the sixth century A.D., was a forerunner of St. Bénézet’s elliptic arch ([p. 81]).
[120] Brangwyn has drawn for the édition de luxe the bridge at Ronda, which dates from 1761. Its architect, José Martin Aldeguela, was even more unfortunate than were Peter Colechurch and the good Saint Bénézet; these masters died before their work was complete, while poor Aldeguela fell from his bridge and was dashed to pieces. Two other bridges, one Moorish and one Roman, cross the chasm at Ronda, but at the upper end where the depth is less prodigious; so their architects had easier problems to solve, and yet they did not equal in any respect the heroic inspiration of Aldeguela. Mr. Edgar Wigram has said that although Ronda Bridge owes much of its effect to its extraordinary site, yet an extraordinary piece of architecture is necessary to command the site; it is the triumph of genius over nature that we feel both at Ronda and in the Pont Napoléon.
[121] The middle arch of 58 ft. span, 17 ft. rise, and 14 ft. in width across the soffit, has archstones which are only 18 ins. deep, and they vary in thickness from 5 to 16 ins.: many of them are 8 and 9 ins. Sometimes there are two headers to answer a course of common archstones; and sometimes two courses of archstones answer one header. The piers are 10 ft. thick, and the middle arch springs about 3 ft. above the river’s bed. A steep road over the bridge diminishes the weight upon the side arches; but Telford believed that if the spandrils had been hollowed the road could have been made with an easy gradient of 1 in 24. The workmanship is very light, and it appears to be stable, though a shivering bridge inspires no more confidence than a stammering man. In 1803, owing to a defect in the foundation of the western abutment, one of the side arches fell, yet the others remained uninjured while the broken one was being rebuilt. So the bridge in the proportion of all its parts must have been very well balanced, despite its quivering alertness and lightness.
[122] Roman examples: the two bridges at Mérida, and the bridge of Salamanca. Mediæval examples: Tudela, Tordesillas, Talavera, Zaragoza, Castro Gonzalo, and El Burgo, near Coruña, the scene of a good fight in Drake’s expedition of 1589.