Léon Lalanne

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Léon Louis Lalanne , actually Chrétien-Lalanne, (born July 3, 1811 in Paris , † March 12, 1892 ibid) was a French civil engineer and politician.

Lalanne studied at the Lycée Louis-le-Grand , where he was a classmate of Évariste Galois in the special class for mathematics, and from 1829 at the École polytechnique . He then worked as a civil engineer, for example, in road construction and in the construction of railway lines (line to Sceaux 1844-1846 under his father-in-law Arnoux). During the revolution of 1848 he was briefly head of a job creation organization in Paris (Ateliers nationaux), which made him unpopular. From 1853 he directed the construction of railway lines in France (section to Strasbourg, Ardennes, Boulogne to Calais, etc.), in Switzerland (1856 to 1860, the railway network to the west) and in northern Spain (1860/61) as well as the Córdoba – Seville route before becoming Inspector General for Bridges and Paths in France. In 1876 he became director of the École nationale des ponts et chaussées . In 1881 he retired and was again involved in politics in the moderate left spectrum. In 1883 he became a senator for life. In 1882 he became chairman of the board of directors of the Paris bus company, which was responsible for the horse-drawn buses in Paris at the time.

With Maurice d'Ocagne , he is considered to be the inventor of the nomogram (1850).

As a civil engineer, he invented a graphic method , known in French as Épure de Lalanne , for optimizing the planning of roads, which means that he can be seen as an early representative of application-oriented network research developed from graph and systems theory : along the planned route as an abscissa, the areas to be removed or removed are applied to earth masses (with a negative or positive sign), the integral gives the moments of mass movement.

In 1879 he became a member of the Académie des Sciences , and in 1881 he was a Grand Officer of the Legion of Honor .

He was the brother of the historian Ludovic Lalanne (1815–1898).

Fonts

  • Mémoire sur l'arithmoplanimétrie (1840)
  • Essai philosophique sur la technologie (1840)
  • Collection de tables pour abréger les calculs relatifs à la réduction des projets de routes et chemins de 6 mètres de largeur (1843)
  • Description et usage de l'abaque ou compteur universel (1845).

Web links

Individual evidence

  1. ↑ Arthur Getis: A Report on the Work of Leon Lalanne. Taylor & Francis Online, March 15, 2010, accessed June 2, 2019 .
  2. ^ Marc Santolini: Sunday Reading. In: Twitter. June 2, 2019, accessed June 2, 2019 .
personal data
SURNAME Lalanne, Leon
ALTERNATIVE NAMES Lalanne, Léon Louis; Chrétien-Lalanne, Léon Louis (real name)
BRIEF DESCRIPTION French civil engineer and politician
DATE OF BIRTH July 3, 1811
PLACE OF BIRTH Paris
DATE OF DEATH March 12, 1892
Place of death Paris