Gods and Robots

by Adrienne Mayor

  Archytas’s pathbreaking work on mechanical mathematics, cubes, and proportions allowed the creation of scale models. Much has been written by modern philosophers and historians of science on Archytas’s principles of mechanics. The Dove appears to have been a plausible historical device. Mechanical engineers speculate that Archytas’s Dove may have been tethered to a cord or stick and powered by steam or compressed air in a tube or metallic bladder controlled by a valve. It had to be reset after each flight (there is no evidence that the Dove had movable wings). A “reasonable reconstruction” of the Dove discussed by Carl Huffman in 2003 suggests that the bird was “connected by a string to a counterweight through a pulley” and its “motion was initiated by a puff of air that caused the dove to fly from a lower perch to an upper perch.” Another hypothetical reconstruction, by Kostas Kotsanas, uses steam or compressed air to launch an aerodynamic bird.24

  It is interesting to compare Archytas’s Dove to two other historical mechanical devices from the fifth and fourth centuries BC, in the district of Elis in the Peloponnese, Greece, where the Olympic Games were held. The first mechanism featured a bronze eagle and dolphin. These figures were the moving parts of the ingenious starting gate for horse and chariot races in the Hippodrome at the Olympic Games. The eagle-and-dolphin mechanism was still operating in the second century AD, when Pausanias (6.20.10–14) described the starting gate. An official operated the machinery from an altar at the gate. To signal the start of the race, the eagle with outstretched wings suddenly flew up in the air and the dolphin leaped down, in view of the spectators. The device was originally made by the Athenian sculptor-inventor Cleoetas (480–440 BC) and later improved by Aristeides, a fourth-century BC artisan. Much admired for his hyperrealistic human statues with minute breathtaking details, such as inlaid silver fingernails, Cleoetas worked with the renowned Athenian sculptor Phidias to create the colossal gold and ivory statue of Zeus at Olympia in 432 BC (their workshop was discovered by archaeologists in the 1950s at Olympia; Phidias also created the enormous chryselephantine Athena statue in the Parthenon, chapter 8). It is likely that the eagle and dolphin on the starting gate were quite lifelike and, like Archytas’s Dove, they must have been somehow tethered.

  Elis also boasted a spectacle that took place during the Dionysia festival celebrating the god of wine. According to Pseudo-Aristotle (On Marvelous Things Heard 842A123), festival goers were invited into a building about a mile from the city to examine three large, empty copper cauldrons. When the people came out, the Elean officials then ostentatiously locked and sealed the building. After a while, the doors were unlocked and visitors allowed to reenter the building. They were surprised to find the three cauldrons now “magically” filled with wine. “The ceiling and walls appear to be intact, so that no one can discern any artifice.” The trick apparently involved a hidden hydraulic technology of pumping the wine into the vessels. The date is unknown, but the description appears in a collection of notes gathered by Aristotle’s students and followers.

  As for Archytas, alongside his military, political, and scientific accomplishments in mathematics, geometry, harmonics, and mechanics, he was also credited—by Aristotle—with inventing a popular children’s plaything, the clacking noisemaker known as the “clapper.”25 His toy clapper and his technological showpiece, the flying Dove, demonstrated mechanical principles while providing a delightful diversion—a welcome alternative to the cruel automata of other rulers.

  A deceptively frivolous automaton of an invertebrate creature was constructed in Athens under oppressive Macedonian rule in the late fourth century BC. Demetrius of Phaleron was appointed to govern Athens by the Macedonian king Cassander in 317 BC. A well-educated orator who was a younger contemporary of Aristotle, Demetrius was sole ruler of Athens until he was forced into exile in 307 BC. He ended up in Alexandria, Egypt, where he was involved in establishing the great library and museum of Alexandria, where many inventors worked (see below). Demetrius later fell out of favor in Alexandria too, and was exiled to the hinterlands where he died of snakebite, about 280 BC.26

  As tyrant of Athens, Demetrius was arrogant, given to excess and extravaganzas. Naturally, he despised democracy and he disenfranchised poor citizens. According to a lost history of the time by Demochares, a rival Athenian orator who defended democracy, in 308 BC Demetrius commissioned a moving replica of a giant land snail that “worked by some internal contrivance.”27 The Greek historian Polybius (12.13) tells us that this Great Snail led the traditional ceremonial procession of the Dionysia, Athens’ great drama festival. Moving from Plato’s Academy outside the city walls to the Theater of Dionysus, it traveled a distance of about 1.8 miles. The composition of the snail and its inner works are not detailed in Polybius’s account. But the phrase “internal contrivance” suggests some self-propelling mechanism. In 1937, Alfred Rehm proposed that a man walking on a treadmill and another to steer were concealed inside the model of the large mollusk. Treadmills existed in antiquity; the massive, mobile “city-taker” siege machine, built in 323 BC by Posidonius for Alexander the Great, might have relied on a treadmill, and a Roman relief of the first century AD shows a huge construction crane powered by many men inside a large treadmill. But Rehm’s theory is still debated.28

  Why bother to create a gigantic moving replica of a lowly snail? One might note that the Dionysia festival was held in winter, when the rains begin and dormant land snails emerge in large numbers to crawl about, so real snails on the move would be conspicuous everywhere in Athens. Demetrius’s oversized snail was so “realistic” that it even left a trail of slime as it inched along the route. This special effect would be easily achieved with a reservoir of olive oil released from a hidden pipe.

  The most significant detail is the fact that the Great Snail was followed by a group of donkeys in the procession. This pairing of snail and asses would be part of the snide joke. Snails were proverbially slow, and because they carried their homes on their backs, they stood for impoverishment. Donkeys were associated with dull-witted, lazy slaves who work only when beaten.29 As Demochares remarked (Polybius 12.13), the point of Demetrius’s spectacle was to taunt “the slowness and stupidity of the Athenians.” The Great Snail itself was harmless, but it was a dramatic and public way for the tyrant to humiliate the Athenians, whose democracy was being crushed by Macedonians and their collaborators.

  A century later, in 207 BC, in Sparta, southern Greece, a malevolent dictator named Nabis seized power and ruled until 192 BC. His reign was long remembered for his barbarous acts, exiling, torturing, and killing masses of citizens. Nabis and his imperious wife, Apega (probably Apia, daughter of the tyrant of nearby Argos), collaborated to extort valuables and money from people under their rule. Their story is told by Polybius, a native of southern Greece who was born around the time of their overthrow. According to Polybius, Apega “far surpassed her husband in cruelty.” When Nabis dispatched Apega to Argos to raise funds, for example, she would summon the women and children and then personally inflicted physical torture until they gave up their gold, jewels, and costly possessions (Polybius 13.6–8, 18.17).

  FIG. 9.3. Portrait of Nabis on silver coin, ruler of Sparta, 207–192 BC, inv. 1896,0601.49 © The Trustees of the British Museum.

  As tyrant, Nabis welcomed a stream of nefarious characters, including pirates from Crete, to his kingdom.30 Perhaps it was one of these opportunists who manufactured, on Nabis’s orders, a mechanical Apega, a “machine” made to “resemble his wife with extraordinary fidelity” (Polybius 13.6-8, 16.13, 18.17). Inspired by his wife’s deeds, “Nabis invented a female robot as evil and deceptive as Pandora,” comments Sarah Pomeroy, a historian of Spartan women. The automaton was clothed in Apega’s expensive finery. We can imagine that the artisan painted a plaster cast or wax model of Apega’s own face to carry off the effect.

  Nabis would summon wealthy citizens and ply them with wine while urging them to turn their property over to him. If any guest refused to comply, Nabis wo
uld say, “Perhaps my lady Apega will be more successful in persuading you.” At the appearance of the replica of Apega, the inebriated guest would offer his hand to the seated “lady.” She stood up, which triggered springs to raise her arms. Standing behind Apega, Nabis manipulated instruments in her back to cause her arms to suddenly clasp the victim. Working levers and ratchets, Nabis then tightened the false Apega’s deadly embrace, drawing the victims closer by degrees. The fancy clothing hid the fact that the palms of her hands, her arms, and her breasts were studded with iron spikes, driven deeper into the victim’s body by the increasing pressure. With this impaling device in the form of his wife, “Nabis destroyed a good number of men who refused his demands,” wrote Polybius (13.6–8).31

  By the time Nabis and Apega came to power, the late third century BC, many inventors and engineers in the Mediterranean world were already designing animated statues and other clever devices for peace and war. An example of a fourth-century apparatus, the ingenious kleroterion (a “randomization” device for selecting citizens to serve in civic offices) has survived. Along with the aforementioned Antikythera device, this lottery machine represents the tip of the iceberg; a great many other practical technological experimentations and other innovations have left no physical traces but were described in ancient texts.

  By the fourth and early third centuries BC, military engineers in Italy, Carthage, and Greece had developed crossbow artillery and powerful torsion catapults, based on complex mechanical formulas and springs, for rulers such as Dionysius of Syracuse and Philip II of Macedonia. For his attempted conquest of Rhodes in 305 BC, Demetrius Poliorcetes, “Besieger of Cities,” had his engineers construct the tallest mechanized siege tower ever built. Equipped with 16 heavy catapults and weighing about 160 tons, the iron-plated wooden “City Taker” required relays of more than 3,000 men to activate. Demetrius also deployed a gigantic battering ram manned by 1,000 soldiers. Archimedes of Syracuse is perhaps the most famous engineer of the Hellenistic era, devising numerous geometry theorems and designing a host of amazing machines utilizing levers, pulleys, screws, and differential gears, and ranging from astronomical apparatus and odometers to heat rays that ignited invading navies and the Claw, a massive grappling hook on a crane to grab and sink enemy ships.32

  Given this rich legacy of classical and Hellenistic inventions, it seems safe to assume that Nabis’s lethal Apega machine was modeled on technological precedents. The Apega replica was self-moving owing to springs that caused her to stand up and raise her arms; Nabis controlled the mechanisms to give the impression that the figure was operating under its own power. The Apega automaton was not heated but could kill victims by forcible embrace, recalling the way the mythical bronze robot Talos crushed people to his chest. Some historians have wondered whether the Apega device was an inspiration for the Iron Maiden, “Eiserne Jungfrau,” the imaginary medieval torture/execution device, a metal cabinet shaped like a female with a spiked interior.

  After the assassination of Julius Caesar in 44 BC, Rome was in turmoil. Marc Antony delivered the dramatic funeral oration over the bier in which Caesar’s ravaged corpse lay out of sight. The historian Appian (Civil Wars 2.20.146–47) described the effects of the speech on the populace. Declaiming “in a kind of divine frenzy” and carried away by “extreme passion,” Marc Antony grabbed a spear and with the point lifted the robe from Caesar’s body and held it aloft so all could see the bloodstained cloth pierced with dagger thrusts. The mourners raised loud lamentations.

  But the theatrical performance was not over. A hidden actor impersonating Caesar’s voice recited the names of his murderers, further roiling the audience. Then from the coffin slowly rose the ravaged body of Caesar. It was an effigy made of wax, realistically displaying the twenty-three brutal knife wounds. The pièce de résistance followed, as the effigy rotated “by a mechanical device to display the pitiful sight.” Crazed with rage and grief, the crowd rushed out to set fire to the Senate where Caesar was slain and tried to burn down the houses of the assassins. The sensational stagecraft of an automated, bloody, wax mannequin in Caesar’s image was carefully orchestrated by Caesar’s allies to manipulate the populace.

  Some monarchs in the ancient Greco-Roman world were enthusiastic patrons of science and devised spectacles of animated statues in order to demonstrate their vast power and grandeur. Such wondrous machines told the world that the king could achieve the impossible.

  One thwarted example of a Hellenistic ruler’s attempt to glorify himself by means of a mechanized spectacle occurred during the reign of King Mithradates VI of Pontus, known for his prodigious ego and love of marvelous machines. Mithradates attracted the best craftsmen, scientists, and engineers to his court in the first century BC. His engineers built stupendous naval and siege machines, and the famous Antikythera device was looted from his kingdom by the Romans (70–60 BC). In about 87 BC, to celebrate his defeat of Roman forces in Greece, Mithradates commissioned a grandiose pageant. Bearing in mind classical Greek images of the winged goddess Nike hovering over victors’ heads, the royal engineers created an immense statue of the goddess, suspended on cables out of sight. Similar deus ex machina technology was used on the stage in classical Greek theatrical performances, but this scheme was off the scale. At the climax of the festivities, the massive Winged Nike would dramatically descend, by a series of pulleys and levers, stretch out her hands and place a victor’s crown on Mithradates’s head, and then majestically ascend to the heavens. That was the plan. But the cables failed and Winged Victory smashed to the ground. The miracle was that no one was harmed, but the terrible omen was inescapable.33

  A memorable, and in this case wildly successful, display of an autocrat’s power took place in third-century BC Egypt, orchestrated by Ptolemy II Philadelphus (283–246 BC), of the powerful Hellenistic Macedonian Greek dynasty that ended with the famous queen Cleopatra in 30 BC. The Ptolemies were avid supporters of the arts and sciences at the new international research center in Alexandria, the library and museum complex founded in about 280 BC (it was mostly destroyed by fire in about 48 BC). Under the Ptolemies, Alexandria became the hub of scientific investigation, and the birthplace of machines, with mechanized public showpieces for theaters, processions, and temples, especially animated statues and automated devices.34

  Ptolemy II Philadelphus married his sister, Arsinoe II, in 278 BC. As we saw, after her death he declared her a goddess and commissioned a miraculous floating statue of her (allegedly using magnets, chapter 5). But Ptolemy II’s reign from 283 to 246 BC is most remembered for the outrageous splendor of his Grand Procession of 279/78 BC, a seemingly endless parade of exotic creatures, living tableaux, costumed dancers, and stunning automated displays that took place over several days. According to descriptions in a history of Alexandria by Callixenus of Rhodes (a contemporary of Ptolemy II who may have attended the event), the magnificent panorama included two dozen golden chariots drawn by elephants, followed by ostriches, panthers, lions, giraffes, and other animals, and a multitude of massive carts or floats, hundreds of performers dressed as satyrs and maenads and other mythic figures, larger-than-life realistic statues of divinities (including Alexander the Great), and engineering marvels. Sadly, like so many ancient texts crucial to our understanding of artificial life and automata in antiquity, Callixenus’s works have vanished. But parts of his extensive account of the parade are preserved by the second-century AD author Athenaeus (Learned Banquet 5.196–203).35

  Ptolemy’s Grand Procession celebrated the Greek god of wine, Dionysus, and featured scenes from his mythology. Observers were dazzled by an enormous statue of Dionysus, 15 feet tall, holding out a huge golden goblet overflowing with wine, surrounded by a crowd of satyrs and Bacchantes, singers, and musicians. Another float bearing an immense winepress, about 30 feet long and 20 feet wide, was pulled by 300 men, while 60 men disguised as satyrs trampled the grapes. There was a vast wineskin made of leopard pelts borne on a heavy cart pulled by 600 men, while a continuo
us stream of wine poured out along the route. Yet another float featured two fountains gushing wine and milk (like those attributed to Hephaestus in Greek myth). The profusion of amazing and costly automated objects and statues on such a staggering scale evoked ancient versions of Uncanny Valley sensations. They fostered the illusion that all these constructions were being animated by the gods and goddesses themselves, giving the impression that Ptolemy could summon divine presences to celebrate his coronation.

  After the cart carrying Dionysus, another astounding sight hove into view: a float with a gigantic seated female statue of Nysa, wearing a golden crown and draped in yellow-dyed garments covered in gold spangles. This Nysa was a true self-moving mechanical automaton. Periodically along the route Nysa stood up, poured a libation of milk from a golden phiale, and sat down again. She did this “without anyone putting their hands on the statue,” commented Callixenus.

  Who was Nysa? Nysa was the name of the mountain where the infant Dionysus was raised, nourished by rain nymphs. In the Hellenistic period, the mountain was personified as Nysa, Dionysus’s nursemaid, so it was logical that she accompanied the god, dispensing milk.

  The huge Nysa automaton, 12 feet high when seated, and the large reservoir for milk would have been heavy. Indeed, Nysa’s cart was reportedly 12 feet wide and pulled by 60 men. Like the other oversized statues, Nysa was not bronze or marble but fabricated of terra-cotta, wood, plaster, and wax and realistically painted. To operate faultlessly and in a dignified manner for the entire length of the slow-moving procession (estimated to have been about 3 miles long), the automaton mechanism, as modern engineers agree, must have been technologically robust.