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18 March 1796 
Utzenstorf, Switzerland 
1 April 1863 
Bern, Switzerland 
Jakob Steiner did not learn to read and write until he was 14 and only went to school at the age of 18, against the wishes of his parents. He then studied at the Universities of Heidelberg and Berlin, supporting himself with a very modest income from tutoring. He was an early contributor to Crelle 's Journal, the first journal devoted entirely to mathematics founded in 1826. He was appointed to a chair at the University of Berlin in 1834, a post he held until his death. He was one of the greatest contributors to projective geometry . He discovered the Steiner surface which has a double infinity of conic sections on it. The Steiner theorem states that the two pencils by which a conic is projected from two of its points are projectively related. Another famous result is the Poncelet Steiner theorem which shows that only one given circle and a straight edge are required for Euclidean constructions. He disliked algebra and analysis and believed that calculation replaces thinking while geometry stimulates thinking. He was described by Thomas Hirst as follows: He is a middleaged man, of pretty stout proportions, has a long intellectual face, with beard and moustache and a fine prominant forehead, hair dark rather inclining to turn grey. The first thing that strikes you on his face is a dash of care and anxiety, almost pain, as if arising from physical suffering  he has rheumatism. He never prepares his lectures beforehand. He thus often stumbles or fails to prove what he wishes at the moment, and at every such failure he is sure to make some characteristic remark.
Source:School of Mathematics and Statistics University of St Andrews, Scotland
