- One of the two points of an orbit, as of a planet or
satellite, which are at the greatest and least distance from the
central body, corresponding to the aphelion and perihelion of a planet,
or to the apogee and perigee of the moon. The more distant is called
the higher apsis; the other, the lower apsis; and the line joining
them, the line of apsides. - In a curve referred to polar coordinates, any point for
which the radius vector is a maximum or minimum. - Same as Apse.
- Sill - The act of throwing or shooting forward. - A jutting out; also, a part jutting out, as of a
building; an extension beyond something else. - The act of scheming or planning; also, that which is
planned; contrivance; design; plan. - 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. - Any method of representing the surface of the earth
upon a plane.