How did the Nysa automaton work? In 2015, historians of mechanical engineering Teun Koetsier and Hanfried Kerle analyzed and diagrammed several hypothetical designs. If the statue was 12 feet high when sitting, it would have been 15 feet tall when standing. Assuming it was powered by mechanical means and with components available at the time, they conclude that a complex arrangement of cams, weights, and a sprocket chain or gear wheels were carefully timed to make Nysa rise from her chair, pour milk, and sit down in a slow, stately manner.
Who made the unprecedented Nysa automaton, one of world’s first working robots? The ancient sources do not say. One candidate was the engineer Ctesibius, thought to have been the first director of the museum at Alexandria. No writings by Ctesibius survive, sad to say, but his inventions, based on hydraulics (pumps, siphons) and pneumatics (compressed air), were very highly regarded, described by Vitruvius, Pliny, Athenaeus, Philo of Byzantium (who worked in Alexandria), Proclus, and Heron of Alexandria. Ctesibius was active in 285–222 BC, and he created a pneumatic drinking horn in a temple honoring Ptolemy II’s late wife, Arsinoe II. Ctesibius, or some of his colleagues, would seem to be the most likely builders of the Nysa robot in Ptolemy’s Grand Procession.36
What about Philo of Byzantium (Philo Mechanicus), the eminent Greek engineer and writer who lived most of his life in Rhodes and Alexandria? His exact dates are unknown, but it is now believed that Philo was born about 280 BC, making him a bit too late for Ptolemy II’s Grand Procession. Philo’s impressive list of machines and plans for self-moving devices in the forms of humans and animals were greatly admired in antiquity and the Middle Ages and are still studied today.37
Philo’s compendium of mechanical works ranged from siege towers to theatrical machines, and he designed a host of devices and automata. Most of his treatises have been lost, but the plans and instructions were preserved in later sources, by Heron and Islamic writers.38 We’ve already met Philo’s version of the god Hephaestus’s robotic assistants, a realistic life-size serving maid with the ability to pour a cup of wine and then dilute it with water (chapter 7). That self-moving mechanical woman of the third century BC has been hailed as the first man-made “robot,” although the Nysa automaton preceded her by some years. Philo preferred to make cunning miniature mechanisms, all the more astounding because of their small scale.
One of Philo’s pieces features an artificial bird that chirps when an owl turns to face it and falls silent when the owl turns away. The mechanism depends on water poured into a vessel to displace air, which is forced out through a small pipe to the bird’s beak; oscillating wavelengths produce notes with different frequencies. A rotating shaft controlled by the water level causes the owl’s rotation. Philo also designed a bird that raises its wings in alarm as a snake approaches its nest. Pouring water into a reservoir lifts a float connected by a rod to the bird’s wings. Yet another enchanting automaton depicts a dragon that roars when a figure of Pan faces it, and relaxes when Pan turns away (a variant features a deer drinking while Pan is turned away).39
Philo was a strong influence on another leading Alexandrian inventor, Heron of Alexandria (AD 10–70), many of whose writings and designs for engines, machines, and automata still survive. Heron assembled amazing machines enacting charming mythic vignettes, using hydraulics and other mechanisms to make them move in complex ways. He also created “Dionysian” devices that appeared to produce wine spontaneously, recalling the self-filling cauldrons in Elis and the wondrous spectacles in Ptolemy’s Grand Procession, described above. Heron famously advised fellow engineers to make small automata so that no one could suspect that they were worked by a person hidden inside. In his treatises On Making Automata and Pneumatica Heron describes stationary and moving devices with complex forms of motion, including “snake-like” movements. His instructions and specifications permit engineering technicians to construct working models.40
A typical assemblage designed by Heron features a bronze Heracles shooting an arrow at a bronze serpent that hisses when struck. Heron also devised miniature automatic theaters. The theater rolled onto a stage by itself, stopped, and performed with “fires flaring on altars, sound effects, and little dancing statues”; then it rolled offstage. It has been called the first programmable device.41 To initiate the chain reactions that create a series of sights and sounds on the little stage, the operator simply pulls a string to activate a steadily descending lead weight in a sand clepsydra (a mechanism based on liquid or sand draining at a steady pace) and then steps aside as spectators observe the spellbinding show (see fig. 9.4 for a working replica of the theater). The stage doors automatically open and close on five scenes of a little Trojan War tragedy titled Nauplius. First, shipbuilders are seen and heard hammering and sawing wood. Next the men push the ships into the sea. Now rocking ships sail on a rough sea with leaping dolphins. A torch signal lures the ships to a rocky shore at night, and in the last act the Greek hero Ajax is seen swimming amid wrecked ships while Athena appears on the left and disappears stage right. Suddenly lightning strikes Ajax and he vanishes in the waves.42
These exquisitely constructed mechanical dramas made by Philo and Heron reproduced in reality some of the phantasmagoric imaginary panoramas on Pandora’s golden crown and Achilles’s shield made by Hephaestus. As described in Homer’s Iliad and Odyssey, the god constructed lifelike miniature people and creatures that seemed to move and make sounds (chapters 5, 7, 8).
Many of the designs for automata devised by Philo and Heron were preserved in early medieval Arabic and Islamic texts—for example, by the Banu Musa brothers in Baghdad (ninth century AD, Iraq) and al-Jazari in the twelfth century. These Hellenistic and medieval Near Eastern influences on European automata and machines of the Middle Ages have been extensively studied.43 Mechanical innovations in early China are also well documented by historians. By the third century BC in China, for example, Qin dynasty (221–206 BC) artisans had developed mechanized puppets and other devices. In about AD 250, the engineer Ma Jun invented a precise south-pointing figure in a gear-driven chariot and a puppet theater powered by a waterwheel.44
During the Tang dynasty (AD 618–907), technological advances resulted in a profusion of sophisticated automata and self-operating devices. Typical examples include an iron mountain with hydraulic pumps to spew liquor from a dragon’s mouth into a goblet and a fleet of moving boats with automated servants to pour wine. Tang engineers created many automatic devices for Empress Wu Zetian (r. AD 683–704). A Buddhist convert, Empress Wu sought to emulate and surpass the veneration of Buddha’s relics in India by King Asoka, the great ruler of the Mauryan Empire in the third century BC. Many legends had grown up around Asoka and were brought back to China by Chinese Buddhist pilgrims. One of the most intriguing legends about Asoka involves mechanical beings.45
FIG. 9.4. Replica of the automated Theater of Heron of Alexandria, based on Philo’s designs. Top, the theater doors open to reveal the sights and sounds of shipbuilders hammering and sawing, controlled by inner workings. Center, ships rock on the choppy sea with leaping dolphins. Next, Ajax drowning amid the wrecked ships, with Athena moving in the foreground. Bottom, mechanism for moving Athena. Working model constructed by Kostas Kotsanas, courtesy of the Kotsanas Museum of Ancient Greek Technology.
Robotic guardians appear in Buddhist legends set in India during the time of the historical kings Ajatasatru and Asoka. Both rulers were entrusted with safeguarding the precious relics of Buddha, whose death occurred sometime between 483 and 400 BC. The Indian legends are remarkable, not only because they describe mechanical warriors defending the bodily remains of Buddha, but because the stories explicitly link the robots to automata invented in the Hellenistic Greco-Roman world. This unexpected historical and geographical connection invites deeper investigation.
King Ajatasatru of Magadha (northeastern India) reigned from about 492 to 460 BC, in his fortified capital of Pataliputta (the city’s ruins lie under modern Patna). According to Buddhist traditions,
he met Buddha and became his devotee. After Buddha’s death and cremation, Ajatasatru constructed a vast stupa (dome) over a deep underground chamber containing the holy ashes and bones. Then, it is said, Ajatasatru devised special defenses to protect Buddha’s relics. Traditional Hindu and Buddhist architecture featured armed guardians of doors and treasures (dvarapalas and yakshas), sometimes sculpted in the form of giant warriors (fig. 9.5).
But Ajatasatru’s guardians were extraordinary. He had his engineers in Pataliputta make a set of automaton warriors to defend the remains of Buddha. It is worth mentioning that according to ancient Jain texts Ajatasatru deployed novel military inventions: examples include a powerful catapult that hurled massive boulders and a mechanized, heavily armored war chariot, something like a “tank” or “robot,” which wielded whirling maces or blades. His automaton guards were also said to have whirling blades.46
The legend relates that it was predestined that Ajatasatru’s automaton guards would remain on duty until a future ruler—King Asoka—would discover and disable the robots, gather up the sacred relics of Buddha, and distribute them among tens of thousands of shrines throughout the realm. King Asoka (304–232 BC) ruled the powerful Mauryan Empire from about 273 to 232 BC in Pataliputta and became a follower of Buddha. During his long reign, Asoka constructed many stupas to enshrine a multitude of Buddha’s relics across his vast kingdom, fulfilling the prophecy of Ajatasatru.47
FIG. 9.5. Two traditional dvarapala-yaksha guardian warriors armed with spears on either side of a table holding Buddha’s relics, panel relief, Kushan, Gandhara, Swat, first to second century AD, inv. 1966,1017.1 © The Trustees of the British Museum. The panel relief is flanked by a pair of six-foot-tall guardian warriors, found at ancient Pataliputta, Mauryan Empire, third to first century BC, plate 13, E. J. Rapson, Cambridge History of India (1922). Collage by Michele Angel.
Several Hindu and Buddhist texts in various translations describe Ajatasatru’s automaton warriors guarding the relics until the arrival of Asoka. The wooden androids were said to whirl with the speed of the wind, slashing intruders with swords. Some traditions attribute their creation to Hindu divinities: Visvakarman, the engineer god, or Indra, the guardian god. But the most arresting and mysterious account of the robot guards has come down to us through a tangled route: it appears in the collection of tales known as the Lokapannatti from Burma, a Pali (sacred language) translation of an older, lost Sanskrit text, which is itself known only from a Chinese translation. The dating of the Lokapannatti is uncertain, perhaps eleventh or twelfth century, but the stories “drew on a rich store of ‘legends’ about Asoka,” a “large variety” of much older oral traditions and lost texts.48
The tale recounts that many yantakara (robot makers) lived in the land of the Yavanas (Greek-speakers; people of the West) in Roma-visaya, the “kingdom of Rome,” a generic term for the West, namely, Greco-Roman-Byzantine culture. The Yavanas’ secret technology of robots (bhuta vahana yanta, “spirit movement machines”) was closely guarded by their government. In “Rome,” robots carry out trade and farming, and they capture and execute criminals. No robot makers are ever allowed to leave “Rome” or reveal their secrets—if they do, robot assassins will pursue and kill them. Rumors of the fabulous Roman robots reached India, inspiring a young artisan-engineer who wished to learn how to make automata. The young man lived in Pataliputta. As noted above, Pataliputta was the large fortified city built by King Ajatasatru in about 490 BC. It reached a peak of prosperity as King Asoka’s capital in the mid-third century BC.
By magical plot contrivances the young man of Pataliputta fulfills his vow to be reincarnated in “Rome”—the Greek-influenced West. He marries and has a son with the daughter of the master robot engineer in Rome. He learns the robot maker’s craft. Then he steals the plans for making robots, sews the papyrus under his skin, and departs for India. Knowing that he will be killed by pursuing robot assassins before he can reach India, he has already instructed his son to take his corpse back to Pataliputta. His son does so, and retrieves the plans. The son creates an army of automated soldiers for King Ajatasatru to protect Buddha’s relics hidden in a deep underground chamber of the secret stupa.
The hiding place and the robots fall into long obscurity. Then one day Ajatasatru’s descendant, the great emperor Asoka, hears the story of Buddha’s hidden relics and the prophecy. Asoka searches everywhere until he discovers the stupa with the underground chamber guarded by the fierce android warriors. In the meantime, the Roman emperor learns of the theft of Western technology: Why, he wonders, does the secret technology in India so closely resemble our own? The Roman emperor sends a gift containing a robot assassin to kill Asoka, but it is thwarted. Violent battles ensue between Asoka and the automaton guards in the underground chamber. Finally, Asoka locates the miraculously long-lived engineer’s son, who shows him how to dismantle and control the “Roman” robots. Emperor Asoka now commands a large robot army himself.
In some versions, the whirling guardian automata are driven by a waterwheel or some other mechanism. In one tale, the engineer god Visvakarman helps Asoka, destroying the robots by shooting arrows precisely into the bolts that hold the spinning constructions together.49 The motif of cleverly disabling the mechanical guardians calls to mind the techno-witch Medea’s destruction of the bronze robot Talos, when he threatened to kill Jason and the Argonauts, by removing the crucial bolt in his ankle (chapter 1).
The “science-fiction” saga of the Roman robots guarding Buddha’s relics highlights the fear of losing control of artificial beings, an age-old theme that appeared in the Greek myth of the sown dragon-teeth army (chapter 4). “Robots can turn on their makers and kill them,” notes Signe Cohen in her study of ancient Indian automata. But the story raises more challenging questions. “Did such technology,” she asks, “really exist or are these stories simply religious myths and folktales?”50
The story clearly relates the mechanical beings defending Buddha’s relics to advanced automata inventions that originated in Roma-visaya, the Greco-Roman West. These narratives, remarks Daud Ali, seem to “encode, albeit obliquely, the real movement and circulation of cultures of ‘techne,’ including both real and imagined objects,” between India and the West.51 How ancient is this kernel of historical reality in the lost Sanskrit tale included in the Lokapannatti? Were the legendary robot guardians in the stupa modeled solely on working automata created in the late Byzantine or medieval Islamic and European periods, as scholars generally assume? Or is it possible that oral lore about the robot guards could have arisen even earlier, influenced by Indian knowledge of real Hellenistic mechanical marvels like those created in Ptolemaic Alexandria in the third century BC, the time frame of the Asoka story?
The historical setting of the tale points to technological exchange about automata between the Mauryan emperors of India and Hellenistic kings. Evidence from history and archaeology confirms cultural contact by the fifth and fourth centuries BC. Notably, the ancient Jain texts, mentioned above, reported that King Ajatasatru’s engineers were constructing military machines in the fifth century BC. Greco-Buddhist syncretism and mutual influence in philosophy and art intensified after Alexander the Great’s campaigns in what is now Afghanistan, Pakistan, and northern India.52 We know that around 300 BC, the two Greek ambassadors, Megasthenes and Deimachus, arrived in the Mauryan court, and they resided in Pataliputta—a city with outstanding Greek-influenced art and architecture. Pataliputta, we recall, was the hometown of the engineer who obtained the plans for making robots from “Rome.”53
King Asoka lived in the third century BC, at a time when automata and other devices were proliferating in Alexandria and other centers of technology in the West. Throughout his kingdom, Asoka left many inscribed pillars and rock inscriptions, some written in ancient Greek and others referring to Hellenistic kings by name, attesting to ongoing cultural exchange and trade with the West. Asoka sent emissaries and corresponded with several Hellenistic rulers, includin
g Ptolemy II Philadelphus in Alexandria, whose spectacular procession in 279/78 BC featured marvelous displays of robotic mythic figures like Dionysus and Nysa. Asoka’s envoys came to Alexandria, and Ptolemy II sent his own ambassador, a Greek named Dionysius, to Asoka’s court in Pataliputta.54
Further evidence of long-lasting cross-cultural influence comes from the journal of the Chinese monk Fa Hsien, one of many Buddhist pilgrims who traveled to Pataliputta, Asoka’s city, in about AD 400. Fa Hsien witnessed the traditional annual procession celebrating Buddha, presumably begun in Asoka’s day. The monk describes the magnificent parade of large four-wheeled carts bearing colossal structures, imposing replicas of stupas five stories high, a succession of towering images of Buddha, Bodisattvas, and other divine beings of gold, silver, and lapis lazuli, with colorful silk banners and canopies, attended by hosts of singers, dancers, and musicians. Fa Hsien does not mention mechanized statues (although automated Buddhist figures were displayed in parades in China in this era).55 One has a sensation of déjà vu, so closely does the scene in Pataliputta resemble the Grand Procession of Ptolemy II Philadelphus in Alexandria in 279 BC, a half century earlier.
Was the tale of Asoka and the robots known to Empress Wu (b. AD 624) and her engineers in Tang China? There were many real and imaginary automata in her era. A large golden Buddha surrounded by rotating mechanical attendants that periodically bowed and tossed incense had been created by the engineers Xie Fei and Wei Mengbian for processions in about AD 340. A sixth-century AD Chinese story recounts how workmen ordered to destroy two Buddha statues were attacked by wrathful Vajrapani guardians. Empress Wu knew the monk Daoxuan (AD 596–667) who designed sacred technology for shrines; in his writings Daoxuan described a fantastic Buddhist monastery in India with many automaton guardians in human and animal forms. We know that Empress Wu idolized Asoka, and that her engineers built “celestial” buildings for Buddha’s relics, as well as mechanical marvels. It seems possible that the Chinese monks who transported Buddha’s teachings, relics, and stupa designs from India to China also transmitted the legend of Asoka and the robots—a story that is preserved in a Chinese translation.56
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