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.
Note: In science, this word (instead of plain) is almost
exclusively used to designate a flat or level surface.
{Plane angle}, the angle included between two straight lines
in a plane.
{Plane chart}, {Plane curve}. See under {Chart} and {Curve}.
{Plane figure}, a figure all points of which lie in the same
plane. If bounded by straight lines it is a rectilinear
plane figure, if by curved lines it is a curvilinear plane
figure.
{Plane geometry}, that part of geometry which treats of the
relations and properties of plane figures.
{Plane problem}, a problem which can be solved geometrically
by the aid of the right line and circle only.
{Plane sailing} (Naut.), the method of computing a ship's
place and course on the supposition that the earth's
surface is a plane.
{Plane scale} (Naut.), a scale for the use of navigators, on
which are graduated chords, sines, tangents, secants,
rhumbs, geographical miles, etc.
{Plane surveying}, surveying in which the curvature of the
earth is disregarded; ordinary field and topographical
surveying of tracts of moderate extent.
{Plane table}, an instrument used for plotting the lines of a
survey on paper in the field.
{Plane trigonometry}, the branch of trigonometry in which its
principles are applied to plane triangles.
Note: The Oriental plane ({Platanus orientalis}) is a native
of Asia. It rises with a straight, smooth, branching
stem to a great height, with palmated leaves, and long
pendulous peduncles, sustaining several heads of small
close-sitting flowers. The seeds are downy, and
collected into round, rough, hard balls. The Occidental
plane ({Platanus occidentalis}), which grows to a great
height, is a native of North America, where it is
popularly called {sycamore}, {buttonwood}, and
{buttonball}, names also applied to the California
species ({Platanus racemosa}).
He planed away the names . . . written on his
tables. --Chaucer.
3. Figuratively, to make plain or smooth. [R.]
What student came but that you planed her path.
--Tennyson.