And we must note the symbol of prosperity—a phallus—carved twice in low-relief on the Pont du Gard. On the western side it graces a springing voussoir in the third arch of the second tier; and there is another on the keystone of the greatest arch, where the river passes. Here the emblem is a double phallus, and when it is touched by sunlight it looks as young as hope, not as uncertain as prosperity.
We cannot put a date on this Roman masterpiece, because in this matter there are differences of opinion. M. Ménard, historian of Nîmes, attributes the work to Agrippa, son-in-law of Augustus, who is said to have ordered its construction about nineteen years before the Birth of Christ. The architecture belongs to the Tuscan order. Its vaults are semicircular, and spring from ledges, or imposts, about 50 centimetres high, and as much in projection. There are four parallel rings of stone in the vaults of the first tier, and three in the second, while the third tier has either one or two. This Roman method of building the under surface of an arch, by laying stones in parallel bands or rings, side by side, but not bonded together, was copied in the Middle Ages ([p. 82]). One point more: the water channel of the aqueduct, placed on top of the third arcade, is 1 m. 30 cm. wide and 1 m. 60 cm. high; it is nearly blocked up with a thick deposit of lime, but when this substance is detached we find on the side walls a deep layer of cement coloured red. The bed of this channel is a solid floor, 22 cm. in thickness, and its component parts are small pebbles mixed with lime and gritty sand.
Like other antique monuments, the Pont du Gard has been ravaged by the brutality of mankind. At the end of the seventeenth century, for instance, during years of religious warfare, so called, the Pont du Gard was often crowded with fugitives and with troops, who made a footway for themselves along the upstream side above the first arcade by means of a strong platform corbelled out from new imposts. Over this road cavalry and artillery passed at full speed, not only shaking the bridge, but causing the topmost tier to develop a curve which is still noticeable. At last the province of Languedoc interfered, and in 1670 careful restoration was begun.
Years later, in 1743, the états généraux decided that a good highway should be built up against the eastern side of the Pont du Gard; and this new bridge, finished in 1747, was perhaps justified by its utility, though it harmed a classic monument. There have been a good many modern restorations, and one day the aqueduct itself may be brought into use again, in accordance with the wishes expressed by a great many persons.[68]
II
France happens to be rich in fine relics of Roman bridge-building. Among her antique monuments there are remains of three aqueducts, at Fréjus and Lyon and Luynes; and every pontist has seen photographs of the aqueduct at Lambèse, in the department of Constantine, Algeria. At Vaison, in Vaucluse, over the river Ouvèze, we find an important Roman bridge, built on two rocks, with a single arch not less than thirty metres in span; and along one embankment is a range of tall and narrow arches that start out from the abutment of the bridge. The Pont de Vaison is not in all respects representative of the best Roman work, for its voussoirs, instead of being rimmed and extra-dossed, are fitted into the spandrils ([p. 282]). I do not know the date of this bridge, but Vaison descends from a famous Roman town, Vasio by name, mentioned by Mela (ii. 5) as one of the richest towns of the Narbonensis.
It is common knowledge—or it should be—that the Romans adorned some of their bridges with a triumphal arch; and it happens, by rare good fortune, that France owns a small example of this Roman pride. It is the Pont Flavien at Saint-Chamas, which in a single arch, forty-two feet wide, spans the rocky bed of the Touloubre. At each entrance there is a triumphal arch seven metres high, flanked at each side by two Corinthian pilasters, upon the summit of which the entablature rests. There is a stone lion at each extremity of the entablature; it stands rampant and looks out into the open country, as if to symbolise for ever the wakeful power of Roman thoroughness. Only one of the four lions belongs to Roman workmanship; the others are much younger, and their proportions are bigger. This bridge, again, which I believe to be unique, bears an inscription, from which we learn that it was founded by a certain L. Donnius Flavus, a flamen of Rome and of Augustus. But the name Augustus was a title of veneration given by custom to all the Cæsars, so that Donnius Flavus and his bridge have uncertain dates.
And now we will take a devious walk along some Roman roads through Gard-Hérault, to see what we shall find in the way of antique bridges. From north-east to south-west the region is crossed by the Via Domitiana, which runs from Lyons to the Pyrenees, going over the Rhône at Arles, and passing by Nîmes, Pont Ambroise, Substantion, Saint-Thibéry, Béziers, and Narbonne. At Pont Ambroise the river Vidourle is partly spanned by the ruins of a very picturesque Roman bridge, but its points of interest belong to an earlier chapter ([p. 82]). Near Castelnau, or Substantion, the Via Domitiana crossed the river Lez by a bridge now wholly destroyed; its abutments can be seen when the water is low, but they add nothing to our knowledge of Roman masonry. In mediæval times this bridge was called the Pont Lairou, Lero being the Latin name of the river Lez.
Not far from Saint-Thibéry the Via passed over the Hérault at that point where, in the seventeenth century (about the year 1678), the river was split into halves by a great flood, which formed the Île des Bénédictins; the Roman bridge is on the western branch of this divided river. Four arches exist, but originally there were nine, with spans ranging from ten to twelve metres. The piers have cutwaters both upstream and downstream, with circular bays nearly two metres high for the relief of spate water. The facing stones are long, and the filling is local volcanic rubble. This bridge was wrecked by a flood before the year 1536.
The Via Domitiana was carried over the Orb, and then, following the ancient road of Colombiers, it crossed the Capestang by a Roman viaduct called the Pons Selmis or Pontserme, which in 1430 was repaired with 500 quarters of stone 2½ pans long by 1¼ pans thick and wide. It was a tremendous viaduct, its length being 1500 metres; the width did not exceed three metres. In the sixteenth century it fell in for want of repair. At the present time only an isolated arch remains, with fragments of two others. In a document of A.D. 782 this bridge is called Pons Septimus.