Arnold Droz-Farny

Arnold Droz-Farny was a Swiss mathematician and teacher, born on 12 February 1856 and died on 14 January 1912. He was born Arnold Droz and later took the added name Farny on marrying Lisa Farny. He studied at the high school of Neuchâtel, then at the Technical School of Stuttgart and at the Ludwig Maximilian University of Munich, where he graduated in mathematics, and began his career teaching in a private school. In 1880 he was appointed to the chair of mathematics at the Cantonal Lycée of Porrentruy, near Basel, where he stayed until ill health forced him to retire in 1908. In the mathematical world he is known for the Droz-Farny line theorem, which he stated in 1899 without proof in an answer to question 14111 in the journal The Educational Times. He was also an amateur numismatist who published articles on the history of coins and, on his death, gave his collection to the cantonal authorities.