The Creators: A History of Heroes of the Imagination (23 page)

Monuments of Hadrian’s ambitions, whims, enthusiasms, and prejudices were spread across the Empire. In northern Britain his great stone wall from Wallsend-on-Tyne to Bowness-on-Solway held the frontier against the barbarians. On one of his travels in Asia Minor he fell in love with a handsome youth named Antinoüs (born c.110) and made him his companion. When Antinoüs drowned in the Nile in 130 there were rumors that he had sacrificed himself for some mysterious purpose. To assuage the emperor’s grief, cults of Antinoüs sprang up across the Empire, and statues of Antinoüs became familiar. A city in Egypt was christened Antinoöpolis.

In the early 130s Hadrian had ordered a ban on circumcision, probably because of his horror of physical mutilation. He had made castration a crime equal to murder. But he ignored the sacred significance of circumcision for the Jews. In 134, protesting Hadrian’s prohibition of their ritual, the Jews of Judaea, led by Bar Kokhba, rose in revolt. Then Hadrian’s officers dissolved Judaea, which became Syria Palaestina under a consular legate and two Roman legions. In this way Hadrian made the Jews a “homeless” people, and created the Jewish Diaspora.

“The explorer of everything interesting” (
omnium curiositatum explorator
) was Tertullian’s (160?–230?) praise of Hadrian. He showed his administrative talents in codifying the praetor’s edicts to make the laws more certain, and in humanizing the treatment of slaves. Hadrian’s creative spirit was best expressed in architecture. The remains of his villa at Tivoli sixteen miles northeast of Rome still charm the tourist. The original country palace, stretching a full mile, displayed his experimental fantasy. There, on the
shores of artificial lakes and on gently rolling hills groups of buildings celebrated Hadrian’s travels in the styles of famous cities he had visited with replicas of the best he had seen. The versatile charms of the Roman baths complemented ample guest quarters, libraries, terraces, shops, museums, casinos, meeting rooms, and endless garden walks. There were three theaters, a stadium, an academy, and some large buildings whose functions we still cannot fathom. Here was a country version of Nero’s Golden House.

Tivoli’s historic significance is less in its grandeur than in its wonderfully relaxed way of shaping the relics of the right-angled Greek masses into curves and vaults and domes. The emperor’s circular island retreat, the Teatro Marittimo, enclosed concave and convex chambers. Tivoli displayed every conceivable form of arch and undulation. There were temples to assorted gods, including one to the Greek-Egyptian god Serapis. The vestibule of the Piazza d’Oro was covered by a curious pumpkin vault, of the design that had excited Apollodorus’ ridicule. The new architecture of interiors revealed itself too in the outward shapes. The exterior of the Piazza d’Oro expressed the curved interior, which was the heart of the building. The architecture of mass was being displaced by an architecture of space, no longer piling and hewing stone for the outside viewer, but creating a novel world within.

Hadrian’s Pantheon in the heart of Rome, like Nero’s renewal of the city, was another example of how catastrophe sparks creativity. For, like the Parthenon, it was not the first public building on its site. There Marcus Agrippa (64?–17?
B.C.
), friend of Augustus, had built an earlier Pantheon, which was destroyed by the fire of 80. Rebuilt by Domitian, it was again destroyed by fire in 110. This gave Hadrian his opportunity.

In his new Pantheon, Hadrian would exploit all the possibilities of concrete with bold design and engineering technology. Astonishingly his building still stands for us to see. It stands because, having been consecrated as a church, it was cared for through the ages. But it must be experienced from within. It was perhaps the first great ancient monument designed as an interior. In its dazzling burnished void we are overwhelmed by the challenging circular emptiness of a rotunda 150 feet (43.3 meters) across and of precisely the same height. The natural light pouring through a circular open skylight reminds us that the natural world is still out there. Eight piers mark semicircular chambers serving as niches. But our eyes are carried upward to the coffered dome.

Modern architects are awed by the ingenuity that used an intricate scheme of concrete brick-reinforced arches to overarch so vast an opening and for eighteen hundred years bore the concrete dome’s enormous weight. What made this possible was artificial stone shaped to order in the very
place where it would be used. This first required a forest of timbers, beams, and struts to provide the hemispherical dome of wood on which the concrete could be poured. Concrete comprised nine tenths of the whole building. Brick only gave body and strength to the concrete and carried down the thrust of the weight. Marble facings and mosaic fragments were just veneer.

Concrete, too, was at the very foundation where it provided a solid deep ring on which the whole rested. For the rotunda walls concrete had been poured into trenches of a thin brick shell. As each layer dried, another brick shell was provided to make a trench for more concrete. And so it went until the terrace level from which the dome curved inward. At this point the timbers provided a wooden dome on which to pour the concrete. And negative wooden molds had been prepared to impress the shapes of the receding coffers.

The Romans had mastered some surprising subtleties with their rough raw material. Their concrete always included an “aggregate” of broken rocks. While these fragments, heavier than the matrix of lime and pozzolana and sand, increased the mass of the concrete and its supporting capacity, they also increased the weight. The higher up one went in the structure, the less need there was to support weight and the more desirable that the material itself should have less weight. A close study of the concrete used in the rising levels of the Pantheon shows an astonishing subtle variation. The weight of aggregate used in the concrete decreases in regular layers upward in the building. The heaviest chunks of aggregate are in the foundations, and then they become lighter in the lower walls. The aggregate in the concrete of the topmost part of the dome is fragments of pumice, one of the lightest of volcanic rocks.

The idea of an intricate wooden frame large and strong enough to support the concrete cast for the Pantheon dome staggered the medieval imagination. So they created a plausible legendary alternative. Was it not possible instead that Hadrian’s engineers had heaped up inside the rising Pantheon walls an enormous rounded mound of earth on which the cement dome could be cast? Of course this posed a new problem of how to clear the earth from the finished cylinder once the cement had dried. For this too they conjectured a solution. The shrewd Hadrian, they suggested, had the foresight to seed the earth with pieces of gold as the mound was built, and so left an automatic incentive for workers clearing the mound when the concrete vault had hardened in place.

To be an architect in concrete required creative organization and timing far beyond those needed for building in cut stone. For stones could be cut to size in advance, set aside, and then fitted as needed. But precisely because concrete was formless it was more demanding, taking shape only as it was
put in place. At some stages one layer of concrete had to be fully dried before another was put on, at other points the layers were to be merged. At still others, like the top horizontal circles of the dome, the concrete had to be still tacky to take the rings of tiles around the oculus. The disciplined gangs of labor in Rome were put to good use. Scores of workmen were timed to arrive at the point where the mortar had dried, while others were climbing up and down ramps to deliver the concrete and the supporting bricks. Some manipulated cranes, and still others clambered up the inner wooden scaffolding, ready to fit facings of marble or trims of bronze.

Once the forest of timbers was removed, the visitor felt himself in a man-made cosmos. When the sun, “the eye of Zeus,” streamed through the oculus at the crest of the dome the whole building became a planetarium. Some called the effect of this heavenly light in the man-made cosmos an “epiphany”—a sudden manifestation of an otherworldly being. “Pantheon” meant temple of all the gods (
templum deorum omnium
). “Perhaps it has this name,” the historian Dio Cassius (155?–post 230) observed a century later, “because it received among the images which decorated it the statues of many gods, including Mars and Venus; but my own opinion of the name is that because of its dome the Pantheon resembles the heavens.” Religious and imperial symbolism combined, for the Roman dominions were as extensive as the heavens, which were both the habitat of the gods and “the canopy of empire.” Only a temple of all the gods could celebrate a state that encompassed the world, and Romans called their Pantheon the temple of the world.

It still carried this message a millennium later. Stendhal found it the very embodiment of the sublime. Shelley, while confessing his “propensity to admire,” reported his impressions on March 23, 1819:

While the Pantheon remains wondrously intact in its domed perfection, it has suffered minor pillages. The Pantheon we see today is not all that Hadrian dedicated in 128. The building was originally fronted by an extensive rectangular columned forecourt as long as the Pantheon itself. Some
modern visitors have been disturbed by the present angular pedimented porch. But a circular building needed a clear signal of its entrance. This the Grecophile Hadrian supplied by a conventional form that might have satisfied Vitruvius, and may even have been built to his textbook specifications. But after this obeisance to tradition, Hadrian made his own radical advance. The first Pantheon, by Agrippa (c.25
B.C.
), had been noted for its caryatids in the familiar Greek orders. Hadrian moved on to the dome. And the same subtle relations between the square, the circle, and the human figure, which Vitruvius had explained, were embodied in the Pantheon rotunda. It was these Vitruvian proportions that Leonardo da Vinci would celebrate. The dome rises from a wall above the paving exactly equal to its own height. In the vertical section the rotunda is half a circle inscribed in the upper half of a square. And the radius of the dome appears to be the same as the interior height of the cylinder.

The preservation of the Pantheon, despite the anti-pagan enthusiasms of the early Middle Ages, was itself a miracle. It was luckily still standing in 608, when Emperor Phocas in Constantinople allowed Pope Boniface IV to consecrate it as a church “after the pagan filth was removed … so that the commemoration of the saints would take place henceforth where not gods but demons were formerly worshipped.” For the five intervening centuries, while the surrounding buildings fell into ruin, the Pantheon had survived. Its metal fittings tempted robbers. The Byzantine emperor Constans II visited Rome long enough to take away its gilded bronze roof tiles, of which he was promptly robbed by Arab pirates off Sicily. The popes tried to improve the structure by adding towers to the front. The belligerent and profligate Pope Urban VIII (1568–1644; pope, 1632–1644) of the aristocratic Barberini family of Florence, the ally of Richelieu—and who first supported, then condemned, Galileo—was an architectural enthusiast. Patron of Bernini, he adored the Pantheon. In 1632 he inscribed on the back of the porch, “Pantheon, the most celebrated edifice in the whole world” (
Pantheon aedificium toto terrarum orbe celeberrium
). Then he proceeded to strip off the bronze from the roof beams of the Pantheon porch for one of his own projects. “What was not done by the barbarians,” the Roman wits quipped, “was done by the Barberinis” (
Quod non fecerunt barberi, fecerunt Barberini
). The Pantheon metal appears to have been used to cast eighty cannon to be emplaced on the Castel Sant’ Angelo, the colossal circular stone mausoleum that Hadrian had built for himself. Urban VIII argued that it was better to use the metal to defend the Holy See than simply to keep rain off the Pantheon porch. Still somehow the Pantheon has managed to retain its original bronze doors.

Despite minor desecrations, the Pantheon has remained the grand symbol of a new age in architecture. Until the twentieth century it was reputed
to be the largest dome ever built (141 feet in diameter). While Hadrian left a bold mark on the architecture of Rome and the West, he was curiously reluctant to leave his name. Having rebuilt Agrippa’s Pantheon, instead of inscribing his own name, he misled historians by restoring Agrippa’s original inscription, “Marcus Agrippa, son of Lucius, three times consul, built this” (
M. AGRIPPA, L.F. COS. TERTIUM
fecit). But the dated bricks leave no doubt that the Pantheon was built between 118 and 128, under Hadrian. Probably it was less modesty than willfulness that made him refuse to sign the greatest architectural monument of the age. No wonder the ancients found him a baffling character—“niggardly and generous, deceitful and straightforward, cruel and merciful, and always in all things changeable.” In 1520 the artist Raphael (1483–1520) chose to be buried there. In the nineteenth century, it became the tomb of the first two kings of the new Italian nation.

One of the versatile Hadrian’s most memorable creations was the plaintive verse he wrote on his deathbed: