Wilhelm Fuhrmann (mathematician)

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Portrait in L. Saalschütz, In memory of Wilhelm Fuhrmann

Wilhelm Ferdinand Fuhrmann (born February 28, 1833 in Burg near Magdeburg , † June 11, 1904 in Königsberg ) was a German mathematician and geometer . The Fuhrmann circle was named after him.

Life

Wilhelm Fuhrmann was born in Burg near Magdeburg in 1833. After his father's death in 1842, his mother married a military doctor. With his transfer to Insterburg, Wilhelm Fuhrmann came to East Prussia at a young age. He left school without a degree and was initially hired as a cabin boy. After a short time at sea, he returned to Insterburg.

At the old town high school in Königsberg i. In the fall of 1853 he made up his Abitur exams. He then studied mathematics, physics and geography at the Albertus University in Königsberg. His unusually great mathematical talent had already been noticed at high school. This talent was confirmed by a fellow student at the mathematics and physics seminar. In his obituary in the annual report of the German Mathematicians Association (1905) L. Saalschütz wrote that Wilhelm Fuhrmann was "definitely the most talented and most capable participant". However, his financial circumstances would not have allowed him to pursue a university career.

In December 1860 Wilhelm Fuhrmann passed the state examination after he had already been at the Realgymnasium (from 1902 Royal High School) in the castle of Königsberg i. Pr. Was employed. In October 1861 he married Minna Reuter, a daughter of the former city court president in Königsberg, Friedrich Ehregott Reuter. With her he had three sons (Viktor, Felix, Oskar) and a daughter. In December 1887 he was appointed professor. In August 1894 he received the Order of the Red Eagle, IV class. Wilhelm Fuhrmann taught at the castle school in Königsberg for 44 years until his death . He died on June 11, 1904 at the age of 71.

Act

Carter triangle with carter triangle (red)

In addition to his main activity as a teacher, he published eleven program treatises for teaching in the field of elementary mathematics between 1864 and 1904.

  1. Transformations of the theta functions (1864)
  2. Some studies on the dependence of geometrical structures (1869)
  3. Some comments on the projective properties of the figures (1875)
  4. Exercises on conic sections (1879)
  5. Problems from lower analysis (1886)
  6. Brocardsche Winkel (1889)
  7. Sentences and exercises from spherical trigonometry (1894)
  8. Contributions to the transformation of algebraic-trigonometric figures, part 1 (1898)
  9. Contributions to the transformation of algebraic-trigonometric figures, part 2 (1899)
  10. Collinear and Orthological Triangles (1902)
  11. Exercises from analytical geometry (1904, post mortem)

His work ties in with his school activity, but clearly points beyond that. Fuhrmann's scientific interest and his merit lie in the field of synthetic geometry . He dedicated his major work, published in 1890, to it: Synthetic proofs of planimetric theorems . The triangular geometry was particularly interesting for him . His most important sentence relates to a circle that Èmile Lemoine and others call after him the Fuhrmann circle. He explained this sentence in French in 1890 in the essay Sur un nouveau cercle associé à un triangle . Translation of Fuhrmann's “Sur un nouveau cercle associé à un triangle” from 2011 and Le cercle de Fuhrmann and L'orthocentre du triangle de Fuhrmann from 2006 provide a translation of the article into English and an examination of the Fuhrmann circle and triangle .

Other fonts (selection)

  • Synthetic proofs of planimetric theorems . Berlin: L. Simion, 1890. Today: Wentworth Press, 2018, ISBN 9780270116830 ( online copy in the Internet archive )
  • Collinear and orthological triangles . Königsberg: Hartung, 1902.
  • Guide to arithmetic, algebra and low analysis . Leipzig: Teubner, 1886.

Individual evidence

  1. ^ Roger A. Johnson: Advanced Euclidean Geometry . Dover 2007, ISBN 978-0-486-46237-0 , pp. 228-229, 300 (first published in 1929 by the Houghton Mifflin Company (Boston) under the title Modern Geometry )
  2. ^ L. Saalschütz: In memory of Wilhelm Fuhrmann . In: Annual report of the German Mathematicians Association . tape 14 , 1905, pp. 56 f . ( digizeitschriften.de ).
  3. ^ L. Saalschütz: In memory of Wilhelm Fuhrmann . In: Annual report of the German Mathematicians Association . tape 14 , 1905, pp. 56-60 .
  4. ^ K. Hagge: The Fuhrmann circle and the Brocard circle as special cases of a more general circle . In: Journal for Math. Teaching . No. 38 , 1907, pp. 257-269 .
  5. ^ W. Fuhrmann: Sur un nouveau cercle associé à un triangle . In: Mathesis . tape 10 , 1890, p. 105-111 .
  6. ↑ J.Vonk, JCFischer: Translation of Fuhrmann's "Sur un nouveau cercle associé à un triangle" . In: Forum Geometricorum . tape 11 , 2011, p. 13–26 ( fau.edu [PDF]).
  7. ↑ J.-L. Ayme: Le cercle de carter. Retrieved June 23, 2019 (French).
  8. ↑ J.-L. Ayme: L'orthocentre du triangle de carter . In: Revistaoim . tape 23 , 2006.
personal data
SURNAME Carter, Wilhelm
ALTERNATIVE NAMES Fuhrmann, Wilhelm Ferdinand (full name)
BRIEF DESCRIPTION German mathematician
DATE OF BIRTH February 28, 1833
PLACE OF BIRTH Castle near Magdeburg
DATE OF DEATH June 11, 1904
Place of death Koenigsberg