Early thermal weapons
[2] Until the 5th century BC, the Greeks had little expertise in siege warfare and relied on a strategy of devastation to draw the enemy out; they destroyed crops, trees and houses.
The Gesta Stephani tells of the deeds of one of Stephen's supporters, Philip of Gloucester, by describing how he "raged in all directions with fire and sword, violence and plunder", reducing territory to "bare fields and dreadful desert".
Generally referred to as "artillery", these engines could hurl, fire or shoot missiles and most could be used or adapted for throwing thermal weapons, by attacking and defending forces.
Usually, such mining or digging machinery was protected by a tortoise (also called a cat, sow, or owl): a covered shed on wheels, which shielded the miners from missile attack.
[30] Defenders might sometimes dig counter-tunnels in order to reach the enemy's mines and launch an attack; frequently thermal weapons were used to drive the besiegers from the tunnels.
[32] Borers differed in size and mechanism, but a typical machine was made from a log of wood, tipped with iron and supported and driven by windlasses or ropes.
A large horse transport ship was packed with cedar torches, pitch, dried brush and other combustibles; above this were suspended cauldrons of sulfur, bitumen and "every sort of material apt to kindle and nourish flame".
[35] Another example occurred during the 886 Siege of Paris, when the Vikings filled three warships with combustible material and pulled them upriver in a failed attempt to destroy the Franks' fortified bridges.
The 10th-century Olga of Kiev is reported to have tied burning tinder to birds which, when released, flew back to their nests in the hostile town and set them alight.
[38] Siege towers and ladders could be fitted with a long, narrow tilting beam at the top, gouged with a groove, so that hot oil and water could be poured down on the enemy defenders during an escalade.
[40] Indian records suggest smoke and fire was used defensively within a fortress to confuse and disorient attackers; iron grills could also be heated and used to block passageways.
[48] The Romans covered their tortoises (mobile siege sheds) with raw hides packed with vinegar-soaked seaweed or chaff, to serve as protection against regular and incendiary missiles.
[50] During the High Middle Ages, the majority of Poland's castles were still made of wood, so uncut stone was frequently added to the front to improve their fire defences.
In Colchester, fires caused by hand grenades (the weapon was called "wildfire" by the combatants) were extinguished using wet clothes saturated in milk and vinegar.
The resulting cage was filled with hot coals or other solid object which could be fired from a much stronger bow or ballista without fear of extinguishing and would be used to ignite straw or thatch roofs from a safer distance.
[66] Mardi bin Ali al-Tarsusi, who wrote a military manual for Saladin in the 12th century, suggested that "naft" could be placed inside blown eggshells, which could be thrown from horseback.
[14] Similar petroleum and bitumen-based incendiary mixtures had been known for centuries before the invention of Greek fire, but this new recipe created a blaze which was extremely difficult to extinguish.
Pouring-oil was used in historic battles, and Josephus described its use at Jotapata in AD 67, saying "the oil did easily run down the whole body from head to foot, under their entire armour, and fed upon their flesh like flame itself.
[74] During the siege at Montreuil-en-Bellay in 1147, a mixture of oils from nuts, cannabis and flax, was heated in iron containers, launched by mangonel, and burst into flames on impact.
The sand penetrated through the armour into the shirts, burned the body, and it could not be helped [...] they died, going mad with horrible pain, in sufferings piteous and unquenchable.Such heated missiles have also been used in mining situations; the 1st century Roman writer Vitruvius describes a counter-mine dug above the attackers' gallery by defenders at the siege of Apollonia.
[80] When Holy Roman Emperor Frederick Barbarossa besieged Crema, Italy in the 12th century, the defenders threw red-hot iron objects down on their attackers.
[83] A similar mixture was used 1700 years later by the Scots, when they dropped bales of wood, tar and sulfur by crane onto the English "sow" (a large protective shield covering the battering ram) at the 1319 siege of Berwick-upon-Tweed.
[43] At the 1215 siege of Rochester Castle, King John ordered that fat from 40 pigs be used to set fire to the mines beneath the keep, which caused it to collapse; a cheap and effective technique in place of the more complicated mixture of sulfur, tallow, gum, pitch and quicksilver he had used in France the previous year.
4th century BC writer Aeneas Tacticus suggested defenders should let wasps and bees into enemy mines,[79] and jars of scorpions were sometimes fired during early bombardment in naval battles.
The defenders filled a clay jar with chicken feathers, which they then lit, using bellows to blow the acrid smoke down the tunnel; unable to approach the pot due to defensive spears, the Romans were forced to abandon their works.
[93] The Chinese wasted little time in applying it to warfare, and they produced a variety of gunpowder weapons, including flamethrowers, rockets, bombs, and mines, before inventing firearms.
[99] With this, we have the three basic features of the gun: a barrel made of metal, high-nitrate gunpowder, and a projectile which totally occludes the muzzle so that the powder charge exerts its full potential in propellant effect.
World War I saw the development of the flamethrower, a modern version of the Byzantine siphons, which used gas under pressure to squirt a mixture of inflammable oil and petrol, ignited by a burning taper.
[128] Similarly, the carcass projectile found new use in the Livens Projector, a primitive mortar that could throw a large canister of inflammable liquid (it was soon used for poison gas instead).
[129][130] Technology improved throughout the 20th century, and the latter half saw the development and use of napalm, an incendiary liquid formed in part from naphtha, which was the main ingredient of the Arabic "naft".
