Yvon Villarceau
Antoine-Joseph Yvon Villarceau was a French astronomer, mathematician, and engineer.
He constructed an equatorial meridian-instrument and an isochronometric regulator for the Paris Observatory.
He wrote Mécanique Céleste. Expose des Méthodes de Wronski et Composantes des Forces Perturbatrices suivant les Axes Mobiles and Sur l'établissement des arches de pont, envisagé au point de vue de la plus grande stabilité.
He is the eponym of Villarceau circles, which are two circular sections of a torus other than the two trivial ones.
A short street in the 16th arrondissement in Paris is named after Villarceau.
