Antoine-Joseph Yvon Villarceau (15 January 1813 – 23 December 1883) was a French

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

, mathematician, and engineer. He constructed an equatorial

meridian Meridian or a meridian line (from Latin ''meridies'' via Old French ''meridiane'', meaning “midday”) may refer to Science * Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon * ...

-instrument and an isochronometric regulator for the

Paris Observatory The Paris Observatory (french: Observatoire de Paris ), a research institution of the Paris Sciences et Lettres University, is the foremost astronomical observatory of France, and one of the largest astronomical centers in the world. Its histor ...

. He wrote ''Mécanique Céleste. Expose des Méthodes de Wronski et Composantes des Forces Perturbatrices suivant les Axes Mobiles'' (Paris: Gauthier-Villars, 1881) and ''Sur l'établissement des arches de pont, envisagé au point de vue de la plus grande stabilité'' (Paris: Imprimerie Impériale, 1853). He is the eponym of

Villarceau circles In geometry, Villarceau circles () are a pair of circles produced by cutting a torus obliquely through the center at a special angle. Given an arbitrary point on a torus, four circles can be drawn through it. One is in a plane parallel to the e ...

, which are two circular sections of a

torus In geometry, a torus (plural tori, colloquially donut or doughnut) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle. If the axis of revolution does not tou ...

other than the two trivial ones. A short street in the

16th arrondissement of Paris The 16th arrondissement of Paris (''XVIe arrondissement'') is one of the 20 arrondissements of the capital city of France. In spoken French, this arrondissement is referred to as ''seizième''. The arrondissement includes part of the Arc de T ...

is named after Villarceau. P1170673 Paris XVI rue Yvon-Villarceau rwk

References

* 19th-century French astronomers 19th-century French mathematicians 1813 births 1883 deaths People from Vendôme {{France-engineer-stub