And spoiling all her gears and goodly ray. Spenser.

All eyes direct their rays
On him, and crowds turn coxcombs as they gaze. Pope.

Bundle of rays. (Geom.) See Pencil of rays, below. -- Extraordinary ray (Opt.), that one of two parts of a ray divided by double refraction which does not follow the ordinary law of refraction. -- Ordinary ray (Opt.), that one of the two parts of a ray divided by double refraction which follows the usual or ordinary law of refraction. -- Pencil of rays (Geom.), a definite system of rays. -- Ray flower, or Ray floret (Bot.), one of the marginal flowers of the capitulum in such composite plants as the aster, goldenrod, daisy, and sunflower. They have an elongated, strap-shaped corolla, while the corollas of the disk flowers are tubular and five-lobed. -- Ray point (Geom.), the common point of a pencil of rays. -- Röntgen ray (rnt"gn) (Phys.), a kind of ray generated in a very highly exhausted vacuum tube by the electrical discharge. It is capable of passing through many bodies opaque to light, and producing photographic and fluorescent effects by which means pictures showing the internal structure of opaque objects are made, called radiographs, or sciagraphs.. So called from the discoverer, W. C. Röntgen. -- X ray, the Röntgen ray; -- so called by its discoverer because of its enigmatical character, x being an algebraic symbol for an unknown quantity.