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.
PLANE
Plane, n. Etym: [F. plane, L. plana. See Plane, v. & a.]
1. (Geom.)
Defn: 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.)
Defn: 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.)
Defn: A block or plate having a perfectly flat surface, used as a standard of flatness; a surface plate.
4. (Joinery)
Defn: 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.