V
Verylittle is known about the Eastern bridges constructed by the Romans. In Jebb’s “By Desert Ways to Baghdad” an illustration is given of a Roman bridge over the Tigris at Diarbekr; and on the same river, at Hassan, between Diarbekr and Mosul, there are ruined piers of another Roman bridge. Again, at Shushter, in Persia, we find a dike and a bridge ascribed to the Roman Emperor Valerian, whom Shapur the First took prisoner at Edessa,A.D.260. The dike is called the Band-i-Mizan, the bridge the Pul-i-Kaisar. But if Valerian helped to build these huge monuments, very little Roman work now remains; seventy yards of dike and bridge were swept away in 1885; and the Pul-i-Kaisar has been rebuilt several times. Indeed, as Brangwyn’s pen-drawing shows, the arches (there are forty in all) differ in style as well as in size and material.
THE PUL-I-KAISARTHE PUL-I-KAISAR AT SHUSHTER IN PERSIA. ITS LENGTH IS 560 YARDS, AND ITS ROADWAY IS 7 YARDS WIDE
THE PUL-I-KAISAR AT SHUSHTER IN PERSIA. ITS LENGTH IS 560 YARDS, AND ITS ROADWAY IS 7 YARDS WIDE
“Persian tradition has it that Ardashir (either Artaxerxes of the old Persian kings or Ardashir of the Sassanians) built the first dike across the river Karun in order to raise the water of the river to the level of the Darian canal. The dike became destroyed and was renewed under the Sassanian ShapurI, by Roman workmen sent for by Valerian, who had been captured by the Persian king in260. That Valerian had a part in constructing these remarkable works does not rest upon any historical basis; we may, however, believe that the Sassanian Ardashir, or his son ShapurI, finding that the river, with its bed in friable soil, was daily getting lower and finally threatened to leave the town and the Mian-do-ab district dry by not filling the Darian canal, engaged Roman workmen. The Gerger canal was cut and the river diverted from west to east of the town. The old river then became emptied and its bed was raised and paved with huge flags, to preventfurther erosion and washing away of the soil and a consequent fall of the river. Then the Band-i-Mizan and the great bridge wereerected....”[81]
In every chapter of this monograph other references to Roman work will be found.
[63]If Rousseau walked along the three tiers of this bridge-aqueduct, then he had what climbers call “a good head,” for there is but little space between the piers and a most unpleasant fall into the river Gardon. Most of us have passed over the top, leaving Alpinists to explore the rest of this wonderful structure.
[64]“Charles Kingsley: His Letters and Memories of his Life.” Edited by his Wife. 1879.Vol. II,pp.176-7.
[65]Sir William Smith, in his great “Dictionary of Greek and Roman Geography,” gives a detailed account of the stonework. “The stone of this bridge is a yellowish colour. Seen under the sun from the west side, the bridge has a brightish yellow tint, with patches of dark colour, owing to the weather. The stone in the highest tier is a concretion of shells and sand, and that in the lower tiers appears to be the same. In the stones in the highest tier there are halves of a bivalve shell completely preserved. The stone also contains bits of rough quartzose rock, and many small rounded pebbles. In floods the Gardon rises 30ft.above its ordinary level, and the water will then pass under all the arches of the lowest tier. The piers of this tier show some marks of being worn by the water. But the bridge is still solid and strong, a magnificent monument of the grandeur of Roman conceptions, and of the boldness of their execution.”
[66]Later we shall see that Perronet, a famous bridge-builder of the eighteenth century, used iron clamps for this purpose.
[67]I believe these measurements to be strictly accurate, unlike those in many books of reference.
[68]Let me add to this account a few details from Sir William Smith’s “Dictionary of Greek and Roman Geography.” “It is generally said that the bridge is entirely built of stones, without mortar or cement. The stones of the two lower tiers are without cement; but the arches of the highest tier, which are built of much smaller stones, are cemented. At the north end of the aqueduct the highest tier of arches and the water channel are higher than the ground on which the aqueduct abuts, and there must have been a continuation of small arches along the top of this hill; but there are no traces of them, at least near the bridge. On the opposite or south side the aqueduct abuts against the hill, which is higher than the level of the channel. There is no trace of the hill having been pierced; and an intelligent man, who lives near the bridge, says that the aqueduct was carried round the hill, and that it pierced another hill further on, where the tunnel still exists....”
[69]See Grangent, Durand et Durant,“Description des Monumens Antiques du Midi de la France,”Paris, 1819, I,p.113, and PlateXL; see also“Géographie Générale du Département de l’Hérault,”published by theSociété Languedocienne,Montpellier, 1905.Vol. III, partII.p.310.
[70]Two arches over the Salado river, some thirty miles below Seville (p.367).
[71]Between Córdova and Andujar, over a small tributary flowing into the Guadalquivir from the south. This bridge has three arches, one a good deal larger than the others; bays are driven through the spandrils for spate water to pass through. The masonry consists of stone in big blocks, and the craftsmanship has a very peculiar feature: the voussoirs are notched or joggled one into the other, like those in the Elizabethan bridge at Ross-on-Wye, Herefordshire. This technique is a thing to be remembered: it occurs in no other Roman bridge that is known to me. The notching adds much to the endurance of an arch ring, yet it has never entered into the technical routine of bridge-builders. Perhaps the dovetailing of the stones has been looked upon as too costly, for it needs much skill and care and time. Mr. Edgar Wigram drew my attention to this little-known Roman bridge, and to the one at Alcantarilla (p.367).
[72]This bridge is a soldier, and claims masculine pronouns.
[73]“Northern Spain,” by Edgar T. A. Wigram, London, 1906,pp.231-2.
[74]The stones laid end-foremost.
[75]The stones laid at full length.
[76]There is conflicting evidence on the date of this monument. Pliny attributed the Marcian Aqueduct to Ancus Marcius, whereas Strabo and Frontinus conjecture that the building got its name from Marcius Rex, a pretor, who in the yearB.C.145, or thereabouts, restored some ancient aqueducts whose first construction did not go back beyond the year 272B.C.Sextus Julius Frontinus, governor of Britain (A.D.75-78), was the author of two monographs that are still extant—one on the Roman aqueducts, and another on the art of war. He was nominatedCurator Aquarum, or Superintendent of the Aqueducts, in 97, nine years before his death. Sir William Smith tells us that the earliest aqueduct was not older than the yearB.C.313. In earlier times the Romans had recourse to the Tiber and to wells sunk in the city. During the sixth century of the Christian era there were fourteen aqueducts at Rome.
[77]Mr. R. Phené Spiers has written admirably on these technical matters.
[78]I take it that the Pons Palatinus, or Senatorius, mentioned by Palladio, was the bridge called by ancient writers the Pons Aemilius, whose piers were founded in the censorship of M. Aemilius Lepidus and M. Fulvius Nobilior, B.C. 179; the arches were finished some years later, when P. Scipio Africanus and L. Mummius were censors. Becker and Canina assume that the Pons Aemilius became the Ponte Rotto, and Degrand and others identify the Palatine bridge of Palladio with the Ponte Rotto.
[79]Degrand says 10m.56 and 8m.1. R. Phené Spiers gives 27ft.for the spans of the three central arches, and the side ones about 20ft.
[80]Gauthey says four, Degrand says five.
[81]Sir A. Houtum-Schindler,C.I.E., “EncyclopædiaBrit.,” 1911, article “Shushter.”