Axel Anthon Bjørnbo

Axel Anthon Bjørnbo (born April 20, 1874 in Copenhagen , † October 6, 1911 in Hellerup ) was a Danish mathematician and librarian.

Life

Axel Anthon Bjørnbo was the son of the philologist Richard Christensen, but changed his surname in 1901 because there was another Christensen who wrote about the history of mathematics. He visited the Borgerdydskolen, where Heiberg taught Greek and his father had been a teacher, and there he read the original Greek mathematicians. From 1891 he studied mathematics (with Hieronymus Zeuthen ) and paleography at the University of Copenhagen . He spent a semester in Munich (with Anton von Braunmühl in the history of mathematics and Ludwig Traube in Latin palaeography), where he was awarded a Dr. phil. received his doctorate . The dissertation was on the spheres of Menelaus , in which he also treated the Latin tradition of the work and the history of the Greek spherical trigonometry. For the dissertation he examined manuscripts in Germany, Austria, France and Italy.

In 1902 he became a librarian at the Royal Library in Copenhagen and Bjørnbo devoted himself to studying medieval mathematical manuscripts. To this end, in 1903 he described a detailed program for registering all mathematical and astronomical medieval manuscripts and himself began to create a catalog (with 2,000 index cards with incipits ), which is in the estate of Gustaf Eneström at the Stockholm Academy of Sciences. He published numerous editions and commentaries on ancient and medieval writings on mathematics and geography. He was able to trace numerous ways of transmission, for example he discovered the Latin translation of Euclid's Elements by Gerhard of Cremona and the direct translation of the Almagest by Claudius Ptolemy from the Greek in southern Italy. He published on the tradition of the astronomical tables of al-Chwarizmi and he found two new manuscripts by Johannes Werner on trigonometry in the Vatican library (De meteoroscopiis, De triangulis sphaericis). He published the essay by Thabit ibn Qurra on the set of Menelaus and treatises on optics from al-Kindi and pseudo-Euclid. Later he dealt with cartography and geography, such as the description of Scandinavia from the 15th century by the Dane Claudius Clavus . According to Menso Folkerts , his editing of manuscripts was characterized by care and accuracy. He always considered all relevant manuscripts in a work edition (in contrast to many of his contemporaries, such as Maximilian Curtze , with whom Bjørnbo was in close contact and whose estate he evaluated after Curtze's death in 1903).

At the Danish Academy of Sciences , Bjørnbo founded a commission in 1906 to register literary sources on Danish history in libraries and archives abroad. He also founded the Copenhagen Librarians' Association in 1908, on whose board he sat until 1910. Bjørnbo died on October 6, 1911, only 37 years old, of a heart attack.

Fonts (selection)

• Studies of Menelaus' Sphere. Contributions to the history of the spherics and trigonometry of the Greeks . Leipzig 1902 ( Treatises on the History of Mathematical Sciences 14)
• About two mathematical manuscripts from the 14th century , Bibl. Math. (3), Volume 3, 1902, pp. 63–75
• The mathematical S. Marco manuscripts in Florence , 4 parts, Bibl. Math. (3), Volume 4, 1903, pp. 238–245, Volume 6, 1905, pp. 230–238, Volume 12, 1911/12, pp. 97-132, 193-224
• On a bibliographical repertory of the handwritten mathematical literature of the Middle Ages , Bibl. Math. (3), Volume 4, 1903, pp. 226–333
• Gerhard von Cremona's translation of Al-Khwarizmi's Algebra and of Euclid's Elements , Bibl. Math. (3), Volume 6, 1905, pp. 239–248
• with Carl S. Petersen: Fyenboen Claudius Claussøn Swart (Claudius Clavus), Nord's oldest cartographer . Copenhagen 1904
  • German translation by Ella Lesser: The Dane Claudius Claussen Swart (Claudius Clavus), the oldest cartographer in the north, the first Ptolemy epigon of the Renaissance . Innsbruck 1909
• Joannis Werneri de triangulis sphaericis libri quatuor. De meteoroscopiis libri sex cum prooemio Georgii Joachimi Rhetici . Two volumes, Leipzig 1907–1913 (Treatises on the History of Mathematical Sciences 24)
  • Volume 1 (1907) De triangulis sphaericis
  • Volume 2 (1913) De meteoroscopiis . Edited by Joseph Würschmidt using the preparatory work by Björnbo. With a foreword by Eilhard Wiedemann
• Al-Khwarizmis trigonometriske tavler, in: Festskrift til HG Zeuthen, Copenhagen 1909, pp. 1–17
• with Sebastian Vogl : Alkindi, Tideus and Pseudo-Euclid. Three optical works . Leipzig 1912
• with Carl Petersen: Anecdota cartographica septentrionalia , 1908
• The astronomical tables of Muhammed ibn Musa al Khwarizmi in the adaptation of Maslama ibn Ahmed al-Madjriti and the Latin translation of Atelhard von Bath on the basis of the preparatory work by A. Bjørnbo and R. Besthorn published in Copenhagen and commented by H. Suter in Zurich , Det Kgl. Vid. Selsk. Skrifter, 7th series, Hist.Fil.Afd. III, 1, Copenhagen 1914
• Thabit's work on the transversal movement (liber de figura sectore). With remarks by H. Suter. Edited and supplemented by studies on the development of the Muslim spherical trigonometry by Dr. H. Bürger and Dr. K. Kohl , Dep. Gesch. Med. Nat., No. 7, 1924

literature

• Menso Folkerts : The Estate of Axel Anthon Björnbo . In: Historia Mathematica , Volume 5 (1978), pp. 333-337.
• Raphael Meyer: Axel Anthon Björnbo . In: Biographical Yearbook for Classical Studies , 35th year (1913), pp. 105–107.
• Menso Folkerts, biography in: Joseph W. Dauben , Christoph J. Scriba (eds.): Writing the history of mathematics , Birkhäuser 2002, pp. 364–367

Web links

Wikisource: Axel Anthon Bjørnbo  - Sources and full texts

• Literature by Axel Anthon Bjørnbo in the catalog of the German National Library

Individual evidence

1. ↑ According to Menso Folkerts, it was not evaluated until 2000, nor was it by Lynne Thorndik, Pearl Kibre, Catalog of Incipits of Medieval Scientific Writings in Latin, 2nd edition 1963