**Jean-Baptiste Brasseur** was a Luxembourg born mathematician who was an influencial teacher of geometry.

- In his early years Brasseur was self-educated but even this presented difficulties since a lack of money meant he could only have a few books from which to study.
- It was Dandelin who had a profound influence on Brasseur - he taught him geometry and encouraged him to undertake research on that topic.
- Brasseur was awarded his doctorate in mathematics and physics in 1829 for his thesis De resolubilitate functionum algebricarum integrarum in factores primi vel secundi gradus Ⓣ(Resolving integer algebraic functions into factors of the first or second degree).
- He also attended lectures at the Sorbonne by the chemist Louis-Jacques Thénard (1777-1857), by the physicists Jean-Baptiste Biot (1774-1862) and Claude Servais Mathias Pouillet (1791-1868), and by two scientists who researched in both physics and chemistry Joseph-Louis Gay-Lussac (1778-1850) and Pierre Louis Dulong (1785-1838).
- However, there was a revolution in Paris in July 1830, and it was following this that Brasseur left the city and returned to Liège.
- At this time Brasseur began twin careers, one as an academic and the other in the military.
- Now we have to look briefly at the events of the time to understand the events of Brasseur's life.
- We have already noted the effects of the Napoleonic wars on Brasseur's education.
- William began a process of increased industrialisation in the south, building roads and bridges, and also set up two new state-funded but partially autonomous universities at Ghent and Liège, the latter being where Brasseur studied.
- Brasseur began giving courses on analytic geometry and descriptive geometry which were designed to complete the instruction of lieutenants of artillery and so allow them take the examinations of the École Militaire necessary to rise to the rank of captain.
- A temporary Faculty was in its place when Brasseur arrived there and he taught elementary mathematics in that Faculty until 1832.
- The university would be re-established two years later but by this time Brasseur held a position in Liège.
- At this time Brasseur took over teaching the Analysis course, the Elementary Mathematics course, and was appointed to the Chair of Applied Mechanics and the Chair of Descriptive Geometry.
- Two years later he became an extraordinary professor and, in the same year, published his book Programme du cours de géométrie descriptive donné par J-B Brasseur Ⓣ(Course of descriptive geometry given by J-B Brasseur).
- When the Royal Society of Sciences of Liège was set up in the 1830s, Brasseur, who was a founder member, was appointed as its first Secretary General, serving in that capacity under four presidents.
- Brasseur's publications, following those mentioned above, include: Applications des projections cotées à diverses recherches sur l'étendue Ⓣ(Applications of listed projections to various researches on the extent) (1841); Lignes de courbure de quelques surfaces exprimées par des équations différentielles partielles, et note sur une propriété de l'hyperboloïde à une nappe, et du paraboloïde hyperbolique Ⓣ(Curved lines on some surfaces expressed by partial differential equations, and note on a property of the hyperboloid of one sheet and the hyperbolic paraboloid) (1843); Sur la double génération des surfaces du second degré par le mouvement d'un cercle Ⓣ(On the double generation of surfaces of the second degree by the movement of a circle) (1843); Note sur un nouvel énoncé des conditions d'équilibre d'un système de forces Ⓣ(Note on a new statement of the conditions of equilibrium of a system of forces) (1846); Mémoire sur divers lieux géométriques du second degré, déterminés par la géométrie descriptive Ⓣ(Memorandum on various loci of the second degree, determined by descriptive geometry) (1846); Transformation du principe des moments en celui des vitesses virtuelles et note sur une construction géométrique de la surface d'élasticités Ⓣ(Transformation of the principle of moments into those of virtual velocity and a note on a geometric construction of the surface of elasticity) (1849); and Note sur une construction graphique de centre de gravité d'un polygone quelquonque, en supposant connue la construction du centre de gravité du triangle Ⓣ(note a graphical construction of the center of gravity of a polygon quelquonque, assuming known construction of the triangle's center of gravity) (1849).
- Jean-Baptiste and Thérèse Brasseur had a four sons, Paul, Alfred, Auguste and Leopold.
- Brasseur died three years after Leopold's death following a chill.
- Following his death, François Folie edited two of Brasseur's works, namely Précis du cours de mécanique appliquée Ⓣ(Summary of an applied mechanics course) and Exposition nouvelle des principes du calcul différentiel et intégral Ⓣ(New exposition of the principles of differential and integral calculus) which were both published in 1868.
- We have already noted above the honour that was given to Brasseur by his election as president of the Royal Society of Sciences of Liège.
- On 26 October1860, Brasseur received the Knight's Cross of the Order of Leopold.
- On 19 February 1868 Brasseur was appointed Officer of the Order of the Oak Crown by the king of the Netherlands and the Grand Duke of Luxembourg.

Born 21 June 1802, Esch-sur-Alzette, French Empire (now Luxembourg). Died 13 May 1868, Liège, Belgium.

View full biography at MacTutor

Origin Luxembourg

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