Principal ray
Principal Prin"ci*pal, a. [F., from L. principalis. See {Prince}.] 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a state; the principal productions of a country; the principal arguments in a case. [1913 Webster]

Wisdom is the principal thing. --Prov. iv. 7. [1913 Webster]

2. Of or pertaining to a prince; princely. [A Latinism] [Obs.] --Spenser. [1913 Webster]

{Principal axis}. See {Axis of a curve}, under {Axis}.

{Principal axes of a quadric} (Geom.), three lines in which the principal planes of the solid intersect two and two, as in an ellipsoid.

{Principal challenge}. (Law) See under {Challenge}.

{Principal plane}. See {Plane of projection} (a), under {Plane}.

{Principal of a quadric} (Geom.), three planes each of which is at right angles to the other two, and bisects all chords of the quadric perpendicular to the plane, as in an ellipsoid.

{Principal point} (Persp.), the projection of the point of sight upon the plane of projection.

{Principal ray} (Persp.), the line drawn through the point of sight perpendicular to the perspective plane.

{Principal section} (Crystallog.), a plane passing through the optical axis of a crystal. [1913 Webster]

The Collaborative International Dictionary of English. 2000.

### Look at other dictionaries:

• principal ray — pagrindinis spindulys statusas T sritis fizika atitikmenys: angl. chief ray; principal ray vok. Hauptstrahl, m rus. главный луч, m; основной луч, m pranc. rayon principal, m …   Fizikos terminų žodynas

• principal ray — noun 1. : principal visual ray 2. : the one ray of the rays entering an optical instrument from any given point of the object that passes through the exact center of the aperture stop …   Useful english dictionary

• principal ray — a large ray, branched or unbranched, larger than the minor or rudimentary rays. In the caudal fin the principal rays are usually attached to the hypural plates, are larger than the rudimentary rays; and usually include, in adults, the branched… …   Dictionary of ichthyology

• Ray (optics) — Ray of light redirects here. For other uses, see Ray of light (disambiguation). In optics, a ray is an idealized narrow beam of light. Rays are used to model the propagation of light through an optical system, by dividing the real light field up… …   Wikipedia

• Principal — Prin ci*pal, a. [F., from L. principalis. See {Prince}.] 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a state; the… …   The Collaborative International Dictionary of English

• Principal axes of a quadric — Principal Prin ci*pal, a. [F., from L. principalis. See {Prince}.] 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a… …   The Collaborative International Dictionary of English

• Principal axis — Principal Prin ci*pal, a. [F., from L. principalis. See {Prince}.] 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a… …   The Collaborative International Dictionary of English

• Principal challenge — Principal Prin ci*pal, a. [F., from L. principalis. See {Prince}.] 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a… …   The Collaborative International Dictionary of English

• Principal of a quadric — Principal Prin ci*pal, a. [F., from L. principalis. See {Prince}.] 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a… …   The Collaborative International Dictionary of English

• Principal plane — Principal Prin ci*pal, a. [F., from L. principalis. See {Prince}.] 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a… …   The Collaborative International Dictionary of English