Alternatively, the story of Archimedes’ mirrors appears to have been invented in the age of Lucian, Galen, and Cassius Dio, about half a millennium after the siege of Syracuse. Summa summarum: I think that Proclus’ experimental weapon, which must have been known to Anthemius, is the origin of the story. The problem is that Zonaras often introduces stories to his excerpt, and this may be one of these additions worse, he also writes that this weapon was used in 514 by one Proclus, when he defended Constantinople against the ships of the Gothic adventurer Vitalianus ( Annals 14.55). However, Tzetzes’ older contemporary Zonaras summarizes Dio’s History of the Roman Empire, and refers to the burning mirror. There’s perhaps one author before Anthemius who may have referred to burning mirrors: the third-century historian Cassius Dio, but his account of the siege is lost. This is the instrument shown in Cabiria, but the experiments have shown that it is too simple to do the job Tzetzes cannot have used an authentic source. The Byzantine author Tzetzes (twelfth century) even offers a detailed description:Īrchimedes constructed a kind of hexagonal mirror, and at an interval proportionate to the size of the mirror, he set similar small mirrors with four edges, moving by links and by a kind of hinge, and made the glass the centre of the sun’s beams … So after that, when the beams were reflected into this, a terrible kindling of flame arose upon the ships, and he reduced them to ashes a bow-shot off ( Chiliades, 2.109-123). On page 153 and 156 (ed.Westerman), he informs us that Archimedes’ secret weapon consisted of many small, flat mirrors. Note that Lucian and Galen do not identify the enemy.Īs far as I know, the first to refer to Archimedes using mirrors, is the Byzantine author Anthemius of Tralles (sixth century) in a book called On miraculous engines. Pyreia is usually translated as “firesticks”. We know more about this from Lucian’s younger contemporary Galen, who offers an account of spontaneous combustion of houses, and adds that “this, they say, was how Archimedes set fire to the enemy ships by means of pyreia” ( On Temperaments 3.2). The first to refer to Archimedes as firemaker appears to have been the satirical writer Lucian, who praises an engineer for having surpassed several legendary engineers, including Archimedes, who invented an instrument to set ships afire ( Hippias 2). This is sufficient to send the story to the country of fairy tales.īut what are the origins of the story? Now, things become more complex. Historians like Polybius, Livy, and Plutarch offer detailed descriptions of the siege of Syracuse and mention new weapons, but the heat ray is not among them. The second argument is that the famous incident is not recorded in our sources. The story is pseudoscientific in its most elementary sense. To really work, the mirror must have a diameter of at least eleven meters, which is larger than the largest telescope mirror ever made.Īs a practical instrument, the weapon can, therefore, not exist, unless Archimedes could suspend the laws of nature. Worse, the object must remain on the same place for some time, which is not very likely: the Roman galleys were subject to waves, winds, and swell. The sources, however, refer to only one mirror or a couple of mirrors. On at least three occasions, people have tried to repeat the trick they established that, if you use dozens of mirrors, you can indeed set fire to an object at a short distance (50-60 meter). Scene from Cabiria: Archimedes' hexagonal mirror (top) sets a Roman ship (front) afire.
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