Peter of Maricourt
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Peter of Maricourt (Peter Peregrinus of Maricourt;[1] French Pierre Pèlerin de Maricourt; Latin Petrus Peregrinus de Maharncuria) (fl. 1269) was a 13th century French scholar who conducted experiments on magnetism and wrote the first extant treatise describing the properties of magnets. His work is particularly noted for containing the earliest detailed discussion of freely pivoting compass needles, a fundamental component of the dry compass soon to appear in medieval navigation.[2] [3] [4]
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[edit] About Epistola de magnete
On August 8, 1269, Peter wrote Epistola Petri Peregrini de Maricourt ad Sygerum de Foucaucourt, militem, de magnete ("Letter on the Magnet of Peter Peregrinus of Maricourt to Sygerus of Foucaucourt, Soldier"), commonly known by its short title, Epistola de magnete. Peter's magnetic experiments and instruments presented here apparently date to a time period twenty years earlier, judging by references in several works of Bacon which had been written in the meantime.[5] Peter's letter is addressed to a Picard countryman named Suggerius (Syger, Sygerus) of Founcaucourt. Suggerius was a friend and neighbor of the author; Founcaucourt bordered on Peter's domain of Maricourt. The village of Maricourt is situated in the department of the Somme, near Péronne.
The letter bears the legend Actum in castris, in obsidione Luceriœ ("Done in camp during the siege of Lucera"), indicating that Peter of Maricourt was in the army of the Duke of Anjou, who, in 1269, laid siege to the city of Lucera. The sobriquet Peregrinus ("pilgrim") suggests that he may have also been a crusader. The "crusade" against Lucera had been sanctioned by the Pope. Peter of Maricourt may have served in the army as an engineer.
"You must realize, dearest friend," Peter writes, "that while the investigator in this subject must understand nature and not be ignorant of the celestial motions, he must also be very diligent in the use of his own hands, so that through the operation of this stone he may show wonderful effects." [6]
[edit] The content of Epistola de magnete
Peter's letters explain how to identify the poles of the compasses. He also describes the laws of magnetic attraction and repulsion. The letters also contain a description of an experiment with a repaired magnet, as well as a number of compasses, one of which "you will be able to direct your steps to cities and islands and to any place whatever in the world." Indeeed, the increasing perfection of magnetic compasses during the thirteenth century allowed navigators such as Vandino and Ugolino Vivaldi to strike out on voyages to unknown lands.
The Epistola de magnete is divided into two parts:
Part One: This is a section that serves as model of inductive reasoning based on definite experiences, and setting forth the fundamental laws of magnetism. He did not discover these laws, but presented them in logical order. Part One discusses the properties of the lodestone and provides the first extant written account of the polarity of magnets. He was thus the first to use the word “pole” in this context. He also provides methods for determining the north and south poles of a magnet. He also describes the effects magnets have upon one another, showing that like poles repel each other and unlike poles attract each other. De Maricourt attributed the earth's magnetism to the action of celestial poles, rather than to the planet itself. [7]
Part Two: This section describes several instruments that utilize the properties of magnets. He attempts to prove that with the help of magnets it is possible to realize perpetual motion (see History of perpetual motion machines). He treats the practical applications of magnets, describing the floating compass as an instrument in common use and proposing a new pivoted compass in some detail.
[edit] Roger Bacon
His disciple, Roger Bacon, pays the highest tribute to him as an experimenter and technician in his Opus tertium and other works (in which Peter is called Petrus de Maharncuria Picardus). According to Bacon, he was a recluse who devoted himself to the study of nature, was able to work metals, invented armour and provided assistance more valuable to Louis IX of France than the king's whole army.
[edit] Legacy
De magnete became a very popular work from the Middle Ages onwards. In 1326, Thomas Bradwardine quoted it in his Tractatus de proportionibus. Scholars at Oxford University made frequent use of it. The first edition of it was issued at Augsburg, in 1558, by Achilles Gasser.
In 1572, Jean Taisner published from the press of Johann Birkmann of Cologne a work entitled Opusculum perpetua memoria dignissimum, de natura magnetis et ejus effectibus, Item de motu continuo. This is considered a piece of plagiarism, as Taisnier presents, as though his own, the Epistola de magnete of Peter of Maricourt and a treatise on the fall of bodies by Gianbattista Benedetti.
William Gilbert acknowledged his debt to Peter of Maricourt and incorporated this thirteenth century scientist's experiments on magnetism into his own treatise, called De magnete.[8]
The Epistola de magnete was later issued by Guillaume Libri (Histoire des sciences mathématiques en Italie, II, Paris, 1838; note v, pp. 487-505), but this edition was full of defects; correct editions were published by P. D. Timoteo Bertelli (in "Bulletino di bibliografia e di storia delle scienze matematiche e fisiche pubblicata da B. Boncampagni", I, 1868, pp. 70-80) and G. Hellmann ("Neudrucke von Schriften und Karten über Meteorologie und Erdmagnetismus, No. 10, Rara magnetica", Berlin, 1898).
A translation into English has been made by Silvanus P. Thompson ("Peter Peregrinus of Maricourt, Epistle to Sygerus of Foucaucourt, Soldier, concerning the Magnet", Chiswick Press, s. d.), also by Brother Arnold ("The Letter of Petrus Peregrinus on the Magnet, A. D. 1269", with introductory note by Brother Potamian, New York, 1904).
The European Geosciences Union (EGU) established the Petrus Peregrinus Medal in recognition for outstanding scientific contributions in the field of magnetism.[1]
[edit] Sources
- ^ Émile Charles, Roger Bacon sa vie, ses ouvrages, ses doctrines, 1861.
- ^ E. G. R. Taylor: “The South-Pointing Needle”, in: Imago Mundi, Vol. 8. (1951), pp. 1-7
- ^ Barbara M. Kreutz, “Mediterranean Contributions to the Medieval Mariner's Compass,” Technology and Culture, Vol. 14, No. 3. (Jul., 1973), p.371
- ^ Frederic C. Lane, “The Economic Meaning of the Invention of the Compass,” The American Historical Review, Vol. 68, No. 3. (Apr., 1963), p.615f.
- ^ E. G. R. Taylor: “The South-Pointing Needle”, in: Imago Mundi, Vol. 8. (1951), p.1f. & 4
- ^ Jean Gimpel, The Medieval Machine: The Industrial Revolution of the Middle Ages (New York, Penguin, 1976), 194-5.
- ^ Anne Locker, Peter the Pilgrim, IET Communications Engineer, August/September 2006, UK ISSN 1479-8352
- ^ Jean Gimpel, The Medieval Machine: The Industrial Revolution of the Middle Ages (New York, Penguin, 1976), 194.
[edit] External links
- Translation of Chapter 3: "The art of making a wheel of perpetual motion", at JLN Labs
- "The Petrus Peregrinus' wheel", modern illustration by JLN Labs
- This article incorporates text from the public-domain Catholic Encyclopedia of 1913.
