A rotifer may be regarded as typically a hemisphere or half an oblate spheroid or paraboloid with a mouth somewhere on the flat end ("disk" or "corona"), which bears a usually double ciliated ring, the outer zone the "cingulum," and inner the "trochus".
Another form of the paraboloid condenser, also due to Wenham, has a plane surface on the upper side.
Foucault invented in 1857 the polarizer which bears his name, and in the succeeding year devised a method of giving to the speculum of reflecting telescopes the form of a spheroid or a paraboloid of revolution.
He also discovered the remarkable fact that the parabolas described (in a vacuum) by indefinitely numerous projectiles discharged from the same point with equal velocities, but in all directions have a paraboloid of revolution for their envelope.
If we project both polyhedra orthogonally on a plane perpendicular to the axis of the paraboloid, we obtain two figures which are reciprocal, except that corresponding lines are orthogonal instead of parallel.
The classical Cassegrain In the classical Cassegrain telescope, the primary mirror is paraboloid shaped.
The surface of the large mirror should be a paraboloid of revolution, that of the small mirror a true optical plane.
The VHF antenna is a cylindrical paraboloid of dimension 40 x 120 meters, in four sections.