Pro-jĕc'tion, n.
n. [Lat. projectio, Fr. projection, Sp. proyección, It. proiezione. See PROJECT, v. t.]
Sense 1. The act of throwing or shooting forward.
Sense 2. A part jutting out, as of a building; an extension beyond something else.
Sense 3. The act of scheming; plan; scheme; design of something to be executed.
Sense 4. The representation of something; delineation; plan; especially, the representation of any object on a perspective plane, or such a delineation as would result were the chief points of the object thrown forward upon the plane, each in the direction of a line drawn through it from a given point of sight, or central point; as, the projection of a sphere. The several kinds of projection differ according to the assumed point of sight and plane of projection in each.
Globular projection. See GLOBULAR.—Gnomonic projection. See GNOMONIC.—Mercator’s projection, a mode of representing the sphere in which the meridians are drawn parallel to each other, and the parallels of latitude are straight lines, whose distance from each other increases with their distance from the equator, so that at all places the degrees of latitude and longitude have to each other the same ratio as on the sphere itself.—Oblique projection, a projection made by parallel lines drawn from every point of a figure, and meeting the plane of projection obliquely.—Orthographic or orthogonal projection. See ORTHOGRAPHIC.—Polar projection, a projection of the sphere, in which the point of sight is at the center, and the plane of projection passes through one of the polar circles.—Powder of projection (Alchemy), a certain powder cast into a crucible or other vessel full of some prepared metal or other matter, which is to be thereby transmuted into gold.—Projection of a point on a plane (Descriptive Geom.), the foot of a perpendicular to the plane, drawn through the point. Math. Dict.—Projection of a straight line on a plane, the straight line on the plane, connecting the feet of the perpendiculars let fall from the extremities of the given line.—Stereographic projection. See STEREOGRAPHIC.