The Lemoine point, a specific geometric center of a triangle, remains the most enduring legacy of the French polymath Émile Lemoine. Beyond his contributions to triangle geometry, he navigated a dual career as a dedicated civil engineer and a prolific mathematician, shaping academic discourse in late 19th-century Paris through his research, teaching, and extensive editorial work.
Early Education and Career
Born in Quimper in 1840, Lemoine attended the Prytanée National Militaire before entering the École polytechnique in 1860. His early interests spanned music and mathematics, and he helped establish the chamber music society La Trompette. Following his graduation in 1866, he held various teaching roles. Although political tensions limited his career opportunities during the Second French Empire, he maintained a rigorous intellectual output, eventually securing a position as a professor at the École polytechnique.
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Lemoine presented his definitive research on the symmedian point at the 1874 meeting of the Association Française in Lille. This work established the properties of the point that now bears his name. During this period, he also helped found the Société Mathématique de France. His mathematical inquiries later expanded into the development of geometrography, a system intended to measure the simplicity of compass and straightedge constructions by quantifying basic operations.
Civil Engineering and Editorial Work
Alongside his academic pursuits, Lemoine served as a civil engineer in Paris, eventually rising to the rank of chief inspector with responsibilities overseeing the city's gas supply. In 1894, he co-founded the mathematical journal L'Intermédiaire des Mathématiciens, serving as its editor until 1912. His career was formally recognized in 1904 with the Prix Francoeur and in 1906 when he was named a Knight of the Legion of Honour.
Fast facts
- Born: 1840, Quimper, France
- Died: 1912, Paris, France
- Alma mater: École polytechnique (1860-1866)
- Primary fields: Mathematics, civil engineering, geometry
- Notable contribution: Lemoine point
- Awards: Knight of the Legion of Honour (1906), Prix Francoeur (1904)
- Editorial role: Editor of L'Intermédiaire des Mathématiciens (1894-1912)
- Professional affiliation: École polytechnique
Questions readers ask
What is the Lemoine point?
It is a specific point within a triangle, also known as the symmedian point, which Lemoine mathematically identified and defined in his 1874 paper.
What was Lemoine's role in civil engineering?
He worked as a civil engineer in Paris for many years, reaching the position of chief inspector, where he managed the city's gas supply infrastructure.
Achievements
- Knight of the Legion of Honour — 1906
- Notable work: Lemoine point
- Notable work: Lemoine's conjecture
- Notable work: Lemoine's problem
- Notable work: Lemoine circle
- Affiliated with École polytechnique
- Educated at Prytanée National Militaire, École polytechnique and Special School of Architecture
- Worked as mathematician, civil engineer and university teacher
