Vulcan

/vul"keuhn/, n.

1. the ancient Roman god of fire and metalworking, identified with the Greek Hephaestus.

2. Mil. a six-barrel, 20mm U.S. Army antiaircraft gun system mounted on an armored personnel carrier and first deployed in 1968.

3. Astron. a hypothetical planet nearest the sun whose existence was erroneously postulated to account for perturbations in Mercury's orbit.

[1505-15; < L Vulcanus]

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I

Ancient Roman god of fire.

He was the counterpart of the Greek Hephaestus. Vulcan was especially associated with the destructive aspects of fire, such as volcanoes or conflagrations, and for this reason his temples were usually located outside the city. His chief festival, the Volcanalia, was marked by a rite in which the heads of Roman families threw fish into the fire. Often invoked to avert fire, he was addressed with epithets such as Mulciber ("Fire Allayer").

II

Hypothetical planet within the orbit of Mercury.

It was predicted in 1859 by Urbain-Jean-Joseph Le Verrier (1811–77) to account for an unexplained component of the precession of Mercury's orbit. Sightings were reported between 1859 and 1878, but these were not confirmed subsequently by observations made either during solar eclipses or when the planet was predicted to cross the Sun. The anomalies of Mercury's orbit were later explained by Albert Einstein's general theory of relativity.

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▪ Roman god

      in Roman religion, god of fire, particularly in its destructive aspects as volcanoes or conflagrations. Poetically, he is given all the attributes of the Greek Hephaestus. His worship was very ancient, and at Rome he had his own priest (flamen). His chief festival, the Volcanalia, was held on August 23 and was marked by a rite of unknown significance: the heads of Roman families threw small fish into the fire. Vulcan was invoked to avert fires, as his epithets Quietus and Mulciber (Fire Allayer) suggest. Because he was a deity of destructive fire, his temples were properly located outside the city. In Roman myth Vulcan was the father of Caeculus, founder of Praeneste (now Palestrina, Italy). His story is told by Servius, the 4th-century-AD commentator on Virgil. Vulcan was also father of the monster Cacus (Cacus and Caca), who was killed by Hercules for stealing his cattle, as Virgil relates in Book VIII of the Aeneid.

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