Greek Fire, Poison Arrows, and Scorpion Bombs

by Adrienne Mayor

  In India, a military manual by Shukra, the Nitishastra (dated to the beginning of the Christian era) describes tubular projectiles thrown by devices used by the infantry and cavalry. The tube, about three feet long, contained saltpeter, sulphur, and charcoal, with other optional ingredients, such as iron filings, lead, and realgar (arsenic). The tubes shot iron or lead balls by “the touch of fire” ignited “by the pressure of flint.” Shukra remarked that “war with [these] mechanical instruments leads to great destruction.”5

  “In practice,” speculates one modern historian of incendiaries, the earliest fire weapons were probably used “against large, inflammable targets at close range,” such as wooden walls and ships. Indeed, the Spartans’ great sulphur and pitch conflagration at Plataia was piled next to the walls of the fort. In a navel battle during the Hannibalic War, the Roman general Gnaeus Scipio fashioned early Molotov cocktails, by lighting jars filled with pitch and resin and hurling them onto the wooden decks of Carthaginian ships.

  Lucan (a Roman writer of the first century AD) writes of casting burning torches dipped in oil and sulphur onto ships’ decks and shooting arrows smeared with burning pitch or wax to ignite the flaxen sails. To make the arrows “burn even more vehemently,” the archers soon learned to melt a mixture of varnish, oil and petroleum, colophon (dense black residue of turpentine boiled down with “sharp” vinegar), and sulphur. Lucan’s description of one firefight at sea is harrowing. Fire, fed by chemicals and the extremely flammable wax caulking of the ships, coursed swiftly through the riggings. It consumed the rowers’ wooden benches and spread everywhere, even over the water itself. Houses near the shore also caught fire, as wind fanned the conflagration. Such fire weapons were clearly intended to destroy the ship and the crew, and the victims faced the choice of burning or drowning. Some sailors clung to blazing planks in the waves, terrified of drowning, while others grappled with the enemy amid the burning wreckage, thinking it best to go down fighting.

  Wooden ships were not just good targets, their flammability also made them attractive delivery systems for fire. During the ill-fated Athenian attack on Sicily in 413 BC, for example, the Syracusans came up with a creative deployment of resinated fire in a naval battle. They loaded an old merchant ship with faggots of torch-pine, set it alight, and simply let the wind blow the ship of fire toward the Athenians’ fleet of wooden triremes. Frontinus, the Roman strategist, reported that in 48 BC, the commander Cassius, also fighting in Sicily, copied the Syracusans and filled several decrepit transport vessels with burning wood, and “set them with a fair wind” to destroy the enemy fleet. Fire-ship tactics required favorable winds, of course, or else the boomerang effect could be disastrous.

  The most stupendous fire ship of all was manufactured in 332 BC, by the Phoenicians, during Alexander the Great’s famous siege of Tyre (an island city on the coast of Lebanon). The historians Arrian and Quintus Curtius described the ship as a floating chemical firebomb. The Phoenician engineers fitted a very large transport ship (originally used for carrying cavalry horses) with two masts and yardarms. From these they suspended four cauldrons brimming with sulphur, bitumen, and “every sort of material apt to kindle and nourish flame.” The foredeck of the ship was packed with cedar torches, pitch, and other flammables, and the hold was filled with dry brush liberally laced with more chemical combustibles.

  Waiting until the wind was favorable, Phoenician rowers towed the great fire ship right up to the offensive mole (a pier extending from the shore to the fortified island) erected by Alexander’s men. The mole had two movable towers and many ballistic engines behind its palisades, all protected with curtains of raw hides in case of flaming arrows. But the Macedonians were unprepared for the unstoppable ship of flames. The Phoenicians ignited the transport and then rowed like mad to crash the burning mass into the mole. They escaped by jumping overboard and swimming to skiffs that returned them to safety. On impact with the mole, the cauldrons on the burning ship spilled their flammable contents, further accelerating the flames. Propelled by the wind, the raging chemical fire incinerated Alexander’s palisades and his siege engines. The Macedonians on the mole were either consumed by flames or leaped into the sea. The Phoenicians chopped at the desperate swimmers’ hands with stakes and rocks until the men drowned or were taken prisoner.6

  The casualties and destruction of the mole did not end Alexander’s siege, nor was the fire ship the last of the fiendish incendiary devices thought up by the Phoenician engineers of Tyre. The Phoenicians, noted Diodorus of Sicily, realized that the Macedonians possessed superior hand-to-hand fighting qualities. They needed an antipersonnel weapon to “offset such a courageous enemy.” There is a clear sense of disapproval in Diodorus’s account, deploring the cowardice of those who turn to chemical weapons to defeat honorable warriors.

  The Phoenician engineers “devised an ingenious and horrible torment which even the bravest could not deflect,” wrote Diodorus. They filled enormous shallow bowls of iron and bronze with fine sand and tiny bits of metal. These pans they roasted over a great fire until the sand glowed red-hot. “By means of an unknown apparatus” (a catapult of some sort), the Phoenicians cast the burning sand “over those Macedonians who were fighting most boldly and brought them utter misery.” There was no escape for anyone within range of the sand. The molten grains and red-hot shrapnel “sifted down under the soldiers’ breastplates and seared their skin with the intense heat, inflicting unavoidable pain.” Alexander’s men writhed, trying to pull off their armor and shake out the burning sand. “Shrieking like those under torture, in excruciating agony, Alexander’s men went mad and died.” The scene at Tyre brings to life in astonishing detail the mythic image of Hercules struggling to escape from his burning tunic.

  The rain of burning sand at Tyre, created more than two millennia ago, also has an uncanny resemblance to the effects of modern metal incendiaries, such as magnesium and thermite. Burning particles of magnesium and molten iron are dispersed by the combustion of intensely hot metal bombs and splatter on victims, making myriad small but extremely deep burns. The high-temperature metallic embers, just like the red-hot sand, penetrate far into the skin and keep on burning, causing deep tissue injury and death.7

  A century after Alexander’s tribulations with burning weapons at Tyre, the Syracusans invented a long-range thermal weapon of amazing effectiveness. During the Roman siege of Syracuse in 212 BC, Archimedes, the brilliant philosopher-mathematician, was commissioned by King Hiero to develop ingenious ways of defending Syracuse. The elderly engineer developed an array of formidable weapons that were used against the Romans, from catapults that hurled burning fireballs to gargantuan grappling cranes that lifted warships completely out of the water and smashed them down with such force that they sank.

  But the most celebrated weapon invented by Archimedes was essentially a heat ray used against the Roman navy commanded by Claudius Marcellus. According to ancient accounts, Archimedes had soldiers polish the concave surfaces of their bronze shields to a mirror finish. Then he assembled them to stand in a parabola shape and tip their shields to create a huge reflective surface to focus the sun’s rays onto the Roman ships’ riggings. Like burning ants or matchsticks with a magnifying glass, the intense heat of the concentrated rays caused the sails and wooden masts to catch fire instantaneously. Marcellus’s fleet was reduced to ashes. He gave up the naval blockade and finally captured Syracuse “by thirst.”

  Marcellus ordered his men to capture Archimedes alive, thinking that the Romans could learn from him (this appears to be the first recorded instance of the practice of capturing or giving immunity to enemy biochemical weapons scientists). But the old man was killed during the brutal sack of the city. Marcellus buried the scientist with honor, decorating his tomb with a geometric cylinder and sphere. The grave was long forgotten, until it was discovered in a bramble patch outside the gates of Syracuse by the Roman orator Cicero, more than a century later. About seven hundred years after Syracuse, in AD 51
5, the philosopher Proklos was said to have used Archimedes’ mirror technique to burn the ships sent by Vitalianus against the Emperor Anastasios.

  Since the Enlightenment, many scientists have undertaken complex calculations and experiments to learn whether Archimedes’ method could have worked. The first series of experiments, by Count Buffon of the Paris Museum of Natural History in 1747, used mirrors to instantly ignite a pine plank 150 feet away. The most recent test was carried out in 1975 by a Greek scientist, Dr. I. Sakkas. He lined up sixty Greek sailors each holding a mirror shaped like an oblong shield. In concert, they tilted the mirrors to direct the sun’s rays at a wooden ship 160 feet away. It caught fire immediately.8

  According to the Latin sources, Marcellus’s Roman sailors were sent into deepening panic at each new weapon deployment, with many believing that the Syracusans were being aided by the gods or by magic. The burning ray that caused their ships to suddenly burst into flame must have seemed like a bolt from the heavens. Indeed, the impressive effects of long-range thermal-ray weapons continue to be sought by weapons designers today. A burning ray in the form of a laser gun that incinerated victims was apparently one of many sophisticated secret weapons tested by the United States during its invasion of Panama, in 1989, according to interviews with medical personnel and eyewitnesses. And a burning ray is the feature of another secret weapon recently developed by the U.S. military: in 2001, the Pentagon unveiled an antipersonnel weapon that fires a beam of intense heat more than a third of a mile. The painful burning sensation, caused by the same microwave energy used to heat food is, however, supposed to disperse crowds without actually cooking or killing anyone. The idea is to mount the microwave ray gun on a military vehicle and point it at individuals or groups. “It’s safe, completely safe,” said Colonel George Fenton, the director of the U.S. Joint Non-Lethal Weapons Directorate, in 2001. “You walk out of the beam [and] there’s no long term effect, none, zero, zip.” Critics point out, however, that severe burns could result if the beam is focused on someone long enough, say someone already incapacitated by other “nonlethal” weaponry such as tear gas or calmative mists—or immobilized in a crowd. That person might be as unable to escape as a Macedonian trapped in the range of the burning sand at Tyre, or a Roman sailor who happened to be in the riggings when Archimedes aimed his heat ray.9

  Bows and arrows, Archimedes’ mirrors, and burning ships proved to be good systems for delivering fire. Torsion catapult technology (based on the spring-tension of ropes made of elastic materials such as sinew or hair), invented in about 350 BC, greatly expanded the horizons for hurling fire-pots and fiery projectiles over the walls of cities, and onto vessels. An even earlier invention for propelling fire, a remarkable flame-blowing contraption, was created at a very early date, in 424 BC, by Sparta’s allies during the Peloponnesian War, the Boeotians.

  This device was built just four years after the Spartans had created the super-conflagration at Plataia, which had ultimately failed due to shifting wind. The design of the primitive Boeotian flamethrower got around the problems encountered by the Spartans at Plataia by creating man-made wind. The device had a large capacity but a short range, like modern flamethrowers. Thucydides described how the flamethrower destroyed the wooden fortifications at Delium, held by the Athenians. The Boeotians hollowed out a huge wooden log and plated it with iron. They suspended a large cauldron from the log by a chain attached to one end of the hollow beam, and an iron tube was inserted through the length of the hollow beam, curving down into the cauldron, which was filled with lighted coals, sulphur, and pitch. The apparatus was mounted on a cart and wheeled right up to the wall. At that point the Boeotians attached a very large blacksmith’s bellows to their end of the beam and pumped great blasts of air through the tube to direct the chemical fire and gases in the cauldron at the wall. The walls and many defenders were incinerated as they attempted to flee their posts, and Delium was captured.10

  A similar flamethrowing device—with the surprising addition of vinegar to the combustibles—was devised by Apollodorus of Damascus, the military engineer for Roman emperors in the second century AD. The addition of vinegar reputedly allowed the flamethrower to destroy stone fortification walls. Historians such as Dio Cassius and Vitruvius also reported that vinegar and fire in combination could shatter rock, but modern scholars have puzzled over how vinegar could accomplish this. The use of vinegar and fire for breaking up stone was first described by the historians Livy and Pliny, in their accounts of how Hannibal’s engineers solved a logistics problem while crossing the Alps in 218 BC. To clear a landslide obstructing Hannibal’s route in the mountains, the Carthaginians felled large trees into a pile on top of the rock slide, then set them on fire. When the huge bonfire had caused the rocks fall to glow red, they poured vinegar on the rocks, which instantly disintegrated.

  The ancient claims that vinegar and fire could somehow destroy walls and the story of Hannibal’s feat were long ridiculed as legends, until scientific experiments in 1992 proved that rocks heated to high temperatures will indeed fracture if a considerable quantity of acidic vinegar is splashed on the hot stone. Further experiments with sour red wine (the source of vinegar in antiquity) produced even more violent results, as the hot rocks sizzled and cracked apart. The scientists found that the chemical reaction worked best on limestone and marble, which happened to be the favorite building stone for ancient fortification walls.11

  With the multitude of types of fire weapons proliferating through the ages, methods of defense against them were sought. Aeneas the Tactician advised that those fighting flaming weapons should shield their faces if possible. He also recommended covering wooden parapets or walls with felt or raw animal hides, the practice carried out by the Plataians defending against Spartan fire arrows, and by the Macedonians besieging Tyre.

  Alum (double sulphate of aluminum and potassium) was known as a fire retardant that could prevent wood combustion: it was mined in Egypt and Pontus. After the temple of Delphi burned down in 548 BC, for example, King Amasis of Egypt sent a large quantity (one thousand talents) of alum to fireproof the timber used for rebuilding. King Mithridates of Pontus fireproofed the wooden towers of his fortresses with alum in 87 BC, and in AD 296 the emperor Constantine fireproofed his siege engines with alum against Persian incendiaries.

  Incendiaries containing sulphur, resins, tar, or petroleum would stick tenaciously to any surface and could only be put out with difficulty, using sand or dirt, wrote Aeneas. To protect siege machines from chemical fires or melted lead poured from above, he suggested that the housings should be covered with clay mixed with hair, or wet mud. Advice on protecting men from chemical burns is notably nonexistent in Aeneas and other ancient Greek and Roman military manuals. In India, however, it was believed that certain ointments rubbed on the skin could protect a soldier from burns and Kautilya’s military treatise of the fourth century BC told how to make fire-resistant salves from sticky plant juices and frog skin. Muslim military books gave recipes for fire retardants that called for a paste of talc, eggwhites, gum, and “salamander-skin” (an early name for the fire-resistant mineral asbestos).

  Another well-known fire retardant in antiquity was vinegar, despite its ability to shatter stone when heated. “If the enemy attempts to set fires with highly combustible materials” such as pitch and sulphur, water cannot soak into or wet the fire, wrote Aeneas. Only “vinegar will put it out and also makes it difficult to restart the fire.” In 74 BC, the city of Cyzicus on the Black Sea successfully beat back Mithridates’ siege and managed to extinguish his fire missiles with vinegar, just as Aeneas advised.

  Defenders using vinegar to put out flames directed at their stone walls would have to take care lest they cause their own heated walls to crack, however, and the besiegers could also use vinegar to resist burning materials thrown on them by defenders. To protect siege equipment, Polyaenus recommended that vinegar, “particularly good at extinguishing every kind of fire,” should be poured or sponged
periodically onto wooden siege machines. Vinegar could also help neutralize choking fumes from fires: Pliny noted its beneficial effects on sneezing and other respiratory problems. Interestingly, in skirmishes between political dissidents and riot police today, the sharp odor of vinegar often hangs in the air; protestors routinely soak handkerchiefs in vinegar and hold them over their faces to counteract the pepper and tear gas sprayed by the police.12

  Burning materials often produce toxic, asphyxiating smoke and this potentially useful aspect of incendiaries was not overlooked in antiquity. Aeneas, for example, advised defenders to build smoky fires and channel the smoke toward besiegers who were attempting to tunnel under walls. This “will be injurious to the men inside and may even kill many of them.” A Chinese historical text, Mo Zi, written around the same time, told how to lower burning bundles of kindling, hemp, and reeds, by chains into tunnels to smoke out diggers: “The enemy will immediately die.”

  Smoke could be used by attackers, too, as the Spartans proved when they created the sulphur and resin fire at Plataia in 429 BC. To overtake Cromium in Sicily in about 397 BC, the Carthaginian general Himilco created a fire with thick black smoke that blew into the eyes of his enemies. Smoke from ordinary fires can be very harmful, even deadly, but sulphurous fumes from chemically activated fires, like at Plataia, would be even more toxic and lethal.

  One could create choking, irritating gases by burning particularly noxious substances. The Chinese had created poisonous smoke clouds by burning sulphur and arsenic to fumigate insects as early as the seventh century BC, a practice that may have led to their interest in developing toxic gases for military use. Ancient Chinese writings contain hundreds of recipes for producing irritating fogs and fumes, and incendiary-weapons manuals also give directions for making poisonous smoke balls. One extremely effective smoke ball compound called for powdered aconite root and wolfbane (species of lethal monkshood), croton beans (a drastic purgative that also causes blisters and pustules), the poisonous mineral arsenic, hallucinogenic hemp, blister beetles, toxic sulphur, plus charcoal and resin.