The Ancient Engineers, page 27
Here Agrippa showed his technical flair. First, he had to prepare a lot of untrained soldiers and sailors to fight a formidable foe. To overcome this handicap, he made Lake Lucrinus—Orata's old oyster-hunting ground—into a training area.
Shallow Lake Lucrinus was separated from the Bay of Naples by a narrow neck of land. Half a mile inland from Lake Lucrinus lay the deeper Lake Avernus in the crater of an extinct volcano. Agrippa joined these lakes with each other and with the bay, using Lake Avernus as a storm-proof anchorage and the other lake for exercises. Few traces now are left of Agrippa's Portus Iulius, as he named this complex, because an earthquake and eruption in 1538 changed the lay of the land.
Agrippa also invented two devices to give him a military advantage. One was a collapsible tower for missile troops, which could be quickly raised from the deck when a ship neared an enemy. The other was a grapnel that could be shot from a catapult, to catch another ship and pull it close for boarding.
When Sextus Pompeius and his pirates were cleaned up, Agrippa became aedile in Rome and began his notable public works. He repaired the older aqueducts, built two new ones, and further improved the water works by constructing 130 water-distributing stations, 300 large cisterns, and 500 fountains. He even took a boat ride through the Cloaca Maxima —the great sewer—to direct its renovation.
In —31, Agrippa took part in Octavianus' war against Marcus An-tonius. Having reduced Antonius' forces to hunger by capturing their naval stations and blockading them in Western Greece, he commanded the whole Octavianist fleet at the decisive battle of Actium. Octavianus, who knew that he was no military genius, watched from a distance.
Having become rich from the property of political enemies, which Octavianus confiscated and gave to his friend, Agrippa spent his own money as well as the state's on public works. He built the first public bath in Rome, the forerunner of those immense bath halls erected by Diocletian and Caracalla. This was his own property, but when he died he left it to Augustus (as Octavianus now called himself) with a hint that it ought to belong to the people. So the Princeps turned the edifice over to the state.
Agrippa also built another bridge across the Tiber, a series of temples and porticoes, and a hall for counting votes. As the emperors soon stopped holding elections, this last building became a theater. Agrippa also built a naval headquarters building and insulae for the masses to live in.
The most celebrated of all Agrippa's constructions was the Temple of All Gods—the Pantheon—in Rome. It consisted of two main parts: a rectangular portico and, behind the portico, a large rotunda.
It is hard to say how much of the present building is Agrippa's original, or even how much it looks like the original. The Pantheon was damaged by fire in the reign of Titus, repaired by Domitian, damaged by fire under Trajan, drastically rebuilt by Hadrian in the +120s, further repaired by Septimius Severus and Caracalla, turned into a Christian church in +608, and stripped of its gold-plated tiles by the Byzantine emperor Constans II, who was slain by Saracen pirates on his way back to Constantinople. During the Middle Ages it was robbed of its marble facings, all the statues that once occupied the niches of the rotunda having already disappeared.
The last big depredation occurred in 1625, when Pope Urban VIII (Maffeo Barberini) took the bronze girders that held up the ceiling of the portico. He melted them up to cast eighty cannon. These he mounted around Hadrian's tomb, which earlier popes had already turned into a private fortress under the name of the Castel Sant' Angelo.
Urban's rape aroused} no little comment, even in an age when the despoiling of ancient monuments was common. A wag of the time said:
Quod non fecerunt barbari fecerunt Barberini
or, "What the barbarians did not do, the Barberini have done." Another writer defended the action on the ground that it was a "worthier destiny . . . that such noble material should keep off the enemies of the Church rather than the rain."3
Any historian of technology would agree with the first comment; for these were the only all-metal girders ever known to have been made in ancient times. We cannot tell, now, whether they formed part of Agrippa's original structure or were put in during Hadrian's rebuilding. In any case, Pope Urban replaced the bronzen structure with one of wood.
The front of the portico, at least, may be original, for it still bears the inscription:
M • AGRIPPA • L • F • COS • TERHVM • FECIT
meaning: "Marcus Agrippa, son of Lucius, made (this) in this third consulship."
The rest of Agrippa's life was spent on military and diplomatic missions. He pacified the Gauls in —19 and found time to build four great roads in Gaul. He also furnished the town of Nemausus (modern Nimes) with a graceful temple, a public bath, an arena, and an aqueduct. All still stand except the bath, which was partly demolished for military reasons in 1577. The aqueduct includes the celebrated Pont du Gard. The temple is now known as the Maison Carree or Square House, At Thomas Jefferson's urging, it was taken as a model for the Virginia State House at Richmond. Jefferson mistakenly thought it had something to do with the Roman Republic, which he admired.
Agrippa went on to Spain, crushed rebellious tribes, and built roads. At Augusta Emerita (modern Merida) he erected temples, baths, a circus, a theater, and a naumachia, of which the last two are still in good condition. Visiting Syria in —15, he built a bath and other structures at Antioch. After further travels and missions, robust and energetic though he seemed, he died suddenly, probably of gout, at 51.
Although Agrippa ranks with Rameses II and Nebuchadrezzar II as a builder, we cannot tell much about his personality. For one thing, the attention of ancient historians was glued to monarchs and generals to the neglect of other folk. For another, Agrippa was such a modest man, in an age when paranoid self-aggrandizement was considered normal behavior, that he refused some of the triumphs Augustus offered him.
We can infer that Agrippa was sober, hard-driving, honest by the standards of the time, devoted to his building projects, but personally not very ambitious. His technical judgment seems to have been sound. In other words, he was the perfect executive engineer. He looked the part, too: heavy-set but rather handsome in a beetle-browed, beak-nosed, jut-jawed way.
Augustus, on the other hand, was a cold, crafty, merciless little man who learned to play to perfection the kindly role of father of his country. Augustus made the shrewdest of his many clever moves when he attached Agrippa to himself. For he came near to falling more than once and might well have done so without Agrippa's staunch help.
The more tightly to bind Agrippa to him, Augustus persuaded Agrippa to divorce his first wife and marry Augustus' niece Marcella, then to divorce Marcella and wed his daughter, the promiscuous Julia. This was probably not so painful as it sounds, because, to most upper-class Romans, marriage was more a matter of business than it is with us. They traded wives back and forth as liberally as movie stars do today. There is reason to think that Augustus planned to name Agrippa his successor, for it probably never occurred to the frail Princeps that he would outlive the lusty Agrippa by a quarter of a century.
A few years before Agrippa's death, Augustus' stepson Tiberius had married Agrippa's eldest daughter Vipsania. After Agrippa's death, Tiberius' mother Livia prevailed upon him to divorce Vipsania and marry the amorous Julia, daughter of Augustus. As Tiberius loved Vipsania, the experience soured him for life, and he became a morose and miserly emperor. Agrippa left several other children, most of whom came to violent ends. A son of one of these children became the emperor Caligula, while one of Caligula's sisters was the dreadful Agrippina, mother of Nero.
The geography and autobiography that Agrippa wrote are lost, but we are lucky to have a work by a contemporary and colleague of his, the architect Marcus Vitruvius. Very little is known about Vitruvius, save that he had .worked for the state as an artillery engineer, that he built a basilica or town hall aj Fanum, and that he described himself as an ugly little old man.
We must think of Vitruvius as a writer on comparatively early Roman architecture. He borrowed most of the historical parts of his treatise from his Greek predecessors, and he discusses the building methods of Hellenistic and Roman Republican times. In his day, the most famous Roman buildings, such as the Colosseum and Hadrian's villa, had not yet been built, so he could not deal with them. Despite certain shortcomings, his treatise is one of our main sources of information on ancient art, architecture, and technics. Although many other such treatises once existed, time has spared Vitruvius' De Architectura alone.
Of Vitruvius' ten "books," the first deals with the qualifications of an architect, architecture in general, and town planning. The second tells of building materials, the use of which it traces from prehistoric times; and it also describes the Roman methods of using masonry, brick, and concrete. The third book is about temples; it derives the proportions of their parts from the proportions of the human body. The fourth tells of the three orders: Doric, Ionic, and Corinthian. The fifth describes public buildings of other kinds—basilicas, theaters, baths, and so on—and discusses acoustics and the wave theory of sound.
The sixth book tells about dwelling houses, while the seventh goes into interior decoration, with much detail on plaster, paint, and mosaics. Book VIII is on water supply: springs, aqueducts, wells, cisterns, and so forth. The ninth deals with geometry, astronomy, measuring, and the design of water clocks. The tenth and last expounds mechanics. In this Vitruvius includes hoisting devices, pumps, water wheels and mills, the water organ, and a geared taximeter to measure the distance a carriage has gone. He also devotes several chapters to catapults, tortoises, sambucae, belfries, and other engines of war.
Vitruvius' work dropped out of sight in the Middle Ages. But, after a manuscript copy of it was rediscovered in +XV and Vitruvius' writings again became well known, architects came to look upon him as an infallible authority, much as medieval schoolmen regarded Aristotle.
After the aged Augustus died, his successor, the somber and thrifty Tiberius, did little in the way of public works, save to build a temple to Augustus and restore Pompeius' theater.
Succeeding Tiberius, the mad Caligula started the aqueduct later known as the Claudian. Instead of concrete and brick, which had become usual for such works, he ordered it made of the costlier stone. He also had the Isthmus of Corinth surveyed with the idea of cutting a canal across it. Otherwise he indulged in such freaks as assembling a bridge of boats across the Bay of Naples, like Xerxes' bridge across the Hellespont, solely to stage parades led by himself in fancy dress.
Claudius, intelligent and well-meaning if prematurely senile, was a more vigorous builder. He finished the languishing Claudian aqueduct. I have told about his drainage of Lake Fucinus. When a grain shortage caused the Roman mob to pelt Claudius with bread crusts, he speedily built the harbor of Portus, next to Ostia, to secure the food supply.
The Julio-Claudian emperor with the most creative engineering ideas, however, was Nero. Usually thought of as a monster, Nero was the most gifted, artistic, and versatile of the line, as well as the most contradictory and the last.
As a Hellenophile, Nero, despite his personal fondness for murder, deplored gladiatorialism and tried to wean the Roman public away from it. When he gave "games," he refused to allow anybody to be killed and even made hundreds of Roman gentlemen appear in the arena to see what it felt like. He also encouraged plays, concerts, and ballets as a substitute for the gory national spectator sport.
Nero was intensely serious about his own artistic ambitions. While his voice was too weak for good professional singing, his poetry is said to have been not bad. When he appeared in an artistic contest, he tried to see that the judges judged his performance fairly. But the judges, knowing the spoiled, capricious, and violent temper of their Princeps, took no chances; they gave him the prize regardless of the merits of the performance.
All this cultural propaganda had no effect on the Romans, who went right back to blood and guts. Nero's artistry they despised, as this was not the sort of thing a Roman gentleman did. They did not especially mind his having his mother murdered; most agreed that Agrippina deserved what she got. But it incensed them that their emperor should so demean the Empire as to play the lyre and sing in public.
In +64, a conflagration burned the greater part of Rome. Gone were many structures that had come down from the days of the kings and the early Republic. Gone, too, were countless art treasures plundered from the Greek lands.
During the fire, men were seen running about with torches, spreading the fire and defying anybody to stop them. Some said that these were Nero's agents, but this is unlikely. Others blamed the Christians, and Nero massacred numbers of Christians as punishment. It is not impossible that the incendiaries were in fact Christians, because Christianity then included many wild-eyed fanatics who went about crying that the world was about to end. But perhaps the arsonists were merely slaves, venting their hatred of their masters and of Rome, or ruffians out for loot.
Nero energetically directed the fire fighting. Afterwards he took prompt and vigorous action to succor the people, collect contributions for their relief, import an emergency store of food, and rebuild the city.
In rebuilding, Nero used the services of a pair of able architects, Severus and Celer. This time the streets were laid out on an orderly gridiron plan, with wide avenues and open spaces in place of the former tangle of crooked alleys. Some of the avenues of modern Rome still follow those of Imperial times; thus the Via del Corso is the old Via Lata or Broad Way. The new insulae were limited in height and required to use a certain amount of fireproof construction. They were also provided with balconies to help in fighting fires, while the water works were extended to make more water available for this purpose.
Nero did not forget to reserve for himself a large burned-over tract, stretching from the Palatine Hill to the Oppian Mount. Here he built an enormous palace, the Golden House, with a mile-long colonnade and a statute of himself, by the sculptor Zenodoros, as big as the Colossus of Rhodes but, as a result of advancing methods of construction, completed in a fraction of the time. Vespasianus later turned this figure into a statue of Helios by putting a crown of solar rays, like those of the Rhodian Helios, on the statue's head. Then the tireless Hadrian, with the help of the architect Decrianus, had the features reworked to look less like Nero's and, by means of twenty-four elephants, moved the statue to a new site.
Severus and Celer persuaded Nero to an even more daring scheme. This was to dig a 160-mile canal along the Italian coast from Ostia to Lake Avernus. There, by means of the channels cut by Agrippa, this canal would communicate with the Bay of Naples. Nero mobilized thousands of convicts to do the work. Digging began, but at Nero's death the project was dropped.
Later historians cited this canal as just one more example of Nero's megalomania. Actually, it was a brilliant idea. By means of this canal, heavy grain freighters would have been able to sail safely to a point close to Rome. As it was, they had either to stop at Puteoli, which raised the cost of goods by requiring their transportation by land for 160 miles, or to anchor at Ostia with its dangerous bar and cramped harbors.
For most of the distance, the canal was quite feasible; you recall that one already existed parallel to the Appian Way. Southeast of Tar-racina the spurs of the Apennines, which come close to the sea in several places, might have given the engineers some trouble, but the project was by no means absurd.
In +66, Nero made a grand tour of Greece. While trying to show the skeptical Greeks what a fine artist and cultured Hellene he was, he revived the idea of cutting a canal across the Isthmus of Corinth. This plan had intrigued not only his uncle Caligula but also several other eminent predecessors like Julius Caesar.
Again Nero mobilized convicts, including 6,000 Jews captured in the Jewish War, just beginning. He himself swung the first mattock and carried off the first basketful of dirt, as Ashurbanipal had done in his day. In +67, however, rumors of plots and revolts at home sent him back to Italy and the digging stopped.
This canal could perhaps have been completed, to the advantage of impoverished Greece. In 1881 a French company, finding Nero's old route the best, undertook to dig the canal. After they gave up, a Greek company finished the job in 1893. If it took twelve years with modern machinery, you can see what a job it would have been for the Romans. The actual quantity of dirt and rock to be moved was so vast that several emperors in succession would have had to work at it.
Back in Italy, Nero did not long survive, having alienated the Senate by his murders of Senators, the army by his pacifism, and all the other Romans by his affectation of Greek culture. When revolt burst out in Gaul and Spain, the bewildered Nero lost what wits he had but kept to the last his interest in technical matters. Having summoned the leading citizens of Rome to discuss the emergency, "after a brief discussion of the Gallic situation, he devoted the remainder of the session to demonstrating a new type of water-organ, and explaining the mechanical complexities of several different models. He even remarked that he would have them installed in the Theater 'if Vindex [one of the rebellious generals] had no objection.'"
A few weeks later, Nero had stabbed himself, murmuring: "What an artist dies in me!"4 Whatever Nero's artistic merits, it looks as though the world also lost a slightly mad but naturally gifted engineer that day.
Three emperors quickly followed Nero but came to violent ends. Then building began again under the competent Vespasianus and continued under his sons Titus and Domitianus. Making use of cross-vaulting on an enormous scale, they built the sinister but awesome Colosseum, as well as temples, baths, and other public buildings.
After Domitianus was murdered in +96, the elderly Nerva reigned for two years and died, having chosen as his successor Marcus Ulpius Traianus—Trajan, as we call him. Trajan, an upper-class provincial of mixed Italian-Spanish^descent, was one of the ablest Principes. Under him, the Empire reached its greatest extent. Nerva, Trajan, and the three who followed them (Hadrian, Antoninus Pius, and Marcus Aurelius) are sometimes called the Five Good Emperors; the period in which they reigned, +96 to +180, was the most prosperous time that Rome was ever to know. The Romans themselves became better behaved, too. They toned down the wild excesses of the preceding two centuries and recovered something of their former dignity and sobriety.
