Source : Webster's Revised Unabridged Dictionary (1913)
Perspective \Per*spec"tive\, a. [L. perspicere, perspectum, to
look through; per + spicere, specere, to look: cf. F.
perspectif; or from E. perspective, n. See {Spy}, n.]
1. Of or pertaining to the science of vision; optical. [Obs.]
--Bacon.
2. Pertaining to the art, or in accordance with the laws, of
perspective.
{Perspective plane}, the plane or surface on which the
objects are delineated, or the picture drawn; the plane of
projection; -- distinguished from the ground plane, which
is that on which the objects are represented as standing.
When this plane is oblique to the principal face of the
object, the perspective is called oblique perspective;
when parallel to that face, parallel perspective.
{Perspective shell} (Zo["o]l.), any shell of the genus
{Solarium} and allied genera. See {Solarium}.
Plane \Plane\, n. [F. plane, L. plana. See {Plane}, v. & a.]
1. (Geom.) A surface, real or imaginary, in which, if any two
points are taken, the straight line which joins them lies
wholly in that surface; or a surface, any section of which
by a like surface is a straight line; a surface without
curvature.
2. (Astron.) An ideal surface, conceived as coinciding with,
or containing, some designated astronomical line, circle,
or other curve; as, the plane of an orbit; the plane of
the ecliptic, or of the equator.
3. (Mech.) A block or plate having a perfectly flat surface,
used as a standard of flatness; a surface plate.
4. (Joinery) A tool for smoothing boards or other surfaces of
wood, for forming moldings, etc. It consists of a
smooth-soled stock, usually of wood, from the under side
or face of which projects slightly the steel cutting edge
of a chisel, called the iron, which inclines backward,
with an apperture in front for the escape of shavings; as,
the jack plane; the smoothing plane; the molding plane,
etc.
{Objective plane} (Surv.), the horizontal plane upon which
the object which is to be delineated, or whose place is to
be determined, is supposed to stand.
{Perspective plane}. See {Perspective}.
{Plane at infinity} (Geom.), a plane in which points
infinitely distant are conceived as situated.
{Plane iron}, the cutting chisel of a joiner's plane.
{Plane of polarization}. (Opt.) See {Polarization}.
{Plane of projection}.
(a) The plane on which the projection is made,
corresponding to the perspective plane in perspective;
-- called also principal plane.
(b) (Descriptive Geom.) One of the planes to which points
are referred for the purpose of determining their
relative position in space.
{Plane of refraction} or {reflection} (Opt.), the plane in
which lie both the incident ray and the refracted or
reflected ray.