Pyr automaton

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Pyr autómaton is an ancient incendiary weapon .

It is a paste made from a combination of petroleum ( naphtha ) with sulfur , wood pitch and unslaked lime that is said to be self-igniting with a drop of water . Filled in clay vessels, these ancient forerunners of the grenades could be shot behind every fortress wall with the help of catapults . It is similar in use to another ancient incendiary weapon which became well known in its development and which many of the ancient historians reported; the Greek fire .

Lore

The Pyr autómaton is mentioned in numerous written sources, in addition to ancient sources (such as Titus Livius , Pliny the Elder ) it is also described in various medieval fireworks books and war books. One of the oldest written mentions can be found in fragmentary copies of the Kestoi of Bishop Sextus Iulius Africanus ( 160/170 – after 240), it contains a recipe and describes its use in magic and in the arts of magic. In the course of numerous copies, however, the content of the Kestoi has been substantially changed over the centuries. According to Siegfried von Romocki, one of the traditional recipes from a copy from the 7th century describes a composition of raw sulfur, saltpeter, and kerdonian pyrite , which are mixed in equal parts, with the addition of asphalt and sycamore juice , in a mortar to form a mass that can be rolled out. to which a little unslaked lime is then added. Other recipes such as an anonymous Arab Alexander story from around 1225 include burnt lime, sulfur and saltpeter. A Chinese recipe from 1161 only calls for quick lime and sulfur. A recipe in the fireworks book of the University Library Freiburg im Breisgau (manuscript Ms. 362) from 1432 recommends a portion of quicklime, one pound of sulfur and five ounces of calcium nitrate, and other recipes include the addition of black powder .

Experimental review

Ferdinand Nibler experimentally tested numerous ancient recipes , mainly with the combinations of substances

  1. Quicklime and sulfur,
  2. the same with the addition of oils or fats
  3. as well as with the addition of (wall) saltpeter .

on their potential suitability.

What all mixtures have in common is the chemical reaction of quicklime quenching, the released thermal energy of 1.79 kWs / cm³ should heat sulfur up to the ignition temperature of 260 ° C necessary for self- ignition and thus trigger the fire at certain points before the enthalpy of fusion when the sulfur melts (from 115.21 ° C) the mixture cools down again. Nibler ruled out all mixtures with saltpeter, since wet saltpeter was not suitable as an oxidizing agent. As a result of his experiments, he writes that with larger amounts (from about 1 kilogram) of the substances and without intimate mixing, the sulfur ignited, which meant that secondary fires with combustible substances could only be reached. During the intimate mixing of the substances, the shielding of atmospheric oxygen was diagnosed as an inhibiting fact , which hindered the ignition.

The pinene contained in the wood pitch has a flash point of 32 ° C, but an ignition temperature of 255 ° C. Petroleum has a flash point of 55 to approx. 74 ° C and an ignition temperature of 210 ° C.

See also

literature

  • Gerhard W. Kramer: The Pyr Autómaton - the self-igniting fires of the Middle Ages . In: Waffen- und Costumekunde - Journal of the Society for Historical Arms and Costume Studies . No. 1 , 2002, ISSN  0042-9945 , p. 49-61 .
  • Karl-Heinz Schlote (Ed.): Chronology of the natural sciences: The path of mathematics and natural sciences from the beginning into the 21st century . German, Frankfurt am Main 2002, ISBN 3-8171-1610-1 , pp. 56 .
  • Ferdinand Nibler: Experiments on chemical lighter medieval war fires based on calcium oxide ; Z. Technikgeschichte, Volume 74, 2007, page 69ff, PDF file , accessed at ruhr-uni-bochum.de in February 2016,
  • Francis CR Thee: Heumeneutical Studies on Theology . In: Julius Africanus and the early Christian view of magic / by Francis CR Thee . Mohr, Tübingen 1984, ISBN 3-16-144552-X , p. 19 .
  • Gerhard W. Kramer, Klaus Leibnitz: The firework book. Gunpowder in Medieval Germany. (German, circa 1400. Translation of MS 362 dated 1432 in the Library of the University of Freiburg / Br., Germany) = Das Feuerwerkbuch . The Arms & Armor Society, London 2001, ( The journal of the Arms & Armor Society Jubilee No. 17, 2001, 03, 1, ISSN  0004-2439 ), pp. 55, 62.
  • Robert James Forbes: Studies in ancient technology . 3. Edition. tape 1 . Brill, Leiden 1993, ISBN 90-04-00621-4 , pp. 106 .
  • JR Partington: A history of Greek Fire and Gunpowder, Johns Hopkins University Press 1960, 1999 (with a new introduction by Bert S. Hall), p. 5ff (Automatic Fire)

Individual evidence

  1. ^ Description of the Pyr automaton in Robert James Forbes: More studies in early petroleum history, 1860-1880 . Hyperion Press, Westport 1976, ISBN 978-0-88355-291-9 , pp. 87 .
  2. ↑ a b Gerhard W. Kramer: The Pyr Autómaton - the self-igniting fire of the Middle Ages . In: Waffen- und Costumekunde - Journal of the Society for Historical Arms and Costume Studies . No. 1 , 2002, ISSN  0042-9945 , p. 49-61 .
  3. ↑ Siegfried of Ramocki: History of explosives . History of explosives chemistry, explosives technology and torpedoing up to the beginning of modern times. tape 1 . Oppenheim, Berlin 1895, p. 9 ff .
  4. ↑ Partington, see literature, p. 8, gives an almost identical recipe from the Byzantine additions to Julius Africanus, except that pyrite and Keraunios lithos (thunder stone) are mentioned as alternatives , which Ferdinand Hoefer interprets as keraunic pyrite (antimony sulfide) (Partington p. 9), but according to Partington the pyrite form can also be marcasite . The preparation should take place in the midday sun (so that morning or evening moisture does not ignite the mixture).
  5. ↑ verified at: Review of Günther Bugge: Schieß- und Sprengstoffe (PDF), at www.ruhr-uni-bochum.de, accessed on February 11, 2016.
  6. ^ Ferdinand Nibler: Experiments on chemical igniters of medieval war fires based on calcium oxide ; Z. Technikgeschichte, Volume 74, 2007, page 69ff, PDF file , accessed from ruhr-uni-bochum.de in February 2016
  7. ↑ Entry on alpha-pinene in the GESTIS substance database of the IFA , accessed on January 24, 2008 (JavaScript required)
  8. ↑ Merck safety data sheet , PDF file
  9. ^ Entry on kerosene with a flash point> 55 ° C in the GESTIS substance database of the IFA , accessed on March 17, 2013 (JavaScript required)

Web links

  • Article on "Ancient weapons of mass destruction" on Spiegel Online
  • Adrienne Mayor: Fiery Finery. In: Archeology. Archaeological Institute of America, accessed February 23, 2013 .