Person: Juel, Christian
Christian Juel was a Danish mathematician, specializing in geometry.
Mathematical Profile (Excerpt):
 In January 1876 Juel took the entrance examinations for the University of Copenhagen.
 Juel completed his Master's Degree at the University of Copenhagen in 1879.
 Juel had spent sixteen years completing his university education and so, despite starting young, was 30 years old before he received his doctorate.
 Juel worked for several years as a mathematics teacher and private tutor of mathematics before being appointed to the Polytechnic Institute in Copenhagen in 1894.
 However, at first it was a journal aimed at school teachers of mathematics but in 1890, when Juel was editor, it was split into Series A containing school level mathematics, and Series B which was a scientific journal containing articles on advanced topics.
 In 1907 Juel was appointed to a newly created chair of rational mechanics at the Polytechnic institute.
 Juel's programme of research extended certain theorems on real manifolds of algebraic geometry to nonalgebraic manifolds, even to nonanalytic manifolds provided the concepts are generalised in a suitable way.
 Although he was not alone in making these improvements, since Corrado Segre also proved similar results, but there is no doubt that Juel's results were obtained independently of Corrado Segre.
 This reproach Professor Juel has set himself (with no less industry than ingenuity) to remove.
 Juel also worked on the theory of finite equal polyhedra and on oval surfaces.
 Although these ideas are clever, Juel did not treat them with care and his writings on this topic, although interesting, are less than precise and leave something to be desired.
 Juel served mathematics in other important ways.
 Juel attended the International Congress of Mathematicians held in Bologna in September 1928.
 In his final years Juel's eyesight deteriorated and he was only able to write his classic text Vorlesungen über projektive Geometrie mit besonderer Berücksichtigung der v.
Born 25 January 1855, Randers, Denmark. Died 24 January 1935, Copenhagen, Denmark.
View full biography at MacTutor
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Origin Denmark
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References
Adapted from other CC BYSA 4.0 Sources:
 O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive