Person: Du Séjour, Achille Pierre Dionis

Achille-Pierre Dionis du Séjour was a French mathematician, astronomer and politician.

Louis-Achille Dionis du Séjour held a legal position in the Cour des Aides, the board of excise, in Paris.
Dionis du Séjour attended the Collège Louis-le-Grand in Paris and the studied at the Faculté de Droit.
Dionis du Séjour applied the latest analytic mathematical methods to the study of problems in astronomy.
Dionis du Séjour also worked on the theory of equations, not attaining the depth of results of Bézout or Lagrange.
On 30 September 1791 the Constituent Assembly was replaced by Legislative Assembly and Dionis du Séjour's role came to an end at this time.
On 31 November 1791 Dionis du Séjour was appointed as a judge of the Paris tribunal but later he resigned and retired to his estate in Argeville.
However from 5 September 1793 to 27 July 27 1794 there was the Reign of Terror during which 17,000 were officially executed.
Dionis du Séjour was in fear of his life throughout this period and the anxiety he experienced may well have hastened his death which was less than a month after the Reign of Terror ended.

Born 11 January 1734, Paris, France. Died 22 August 1794, Vernou (near Fontainebleau), France.

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Astronomy

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O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive