In geometry, Wallis's conical edge is a ruled surface given by the parametric equations
x=v\cosu, y=v\sinu, z=c\sqrt{a2-b2\cos2u}
Wallis's conical edge is also a kind of right conoid. It is named after the English mathematician John Wallis, who was one of the first to use Cartesian methods to study conic sections.[1]