英文字典中文字典51ZiDian.com

The Collaborative International Dictionary of English v.0.48 (gcide)

Globular \Glob"u*lar\, a. [Cf. F. globulaire.]
Globe-shaped; having the form of a ball or sphere; spherical,
or nearly so; as, globular atoms. --Milton.
[1913 Webster]

{Globular chart}, a chart of the earth's surface constructed
on the principles of the globular projection.

{Globular projection} (Map Projection), a perspective
projection of the surface of a hemisphere upon a plane
parallel to the base of the hemisphere, the point of sight
being taken in the axis produced beyond the surface of the
opposite hemisphere a distance equal to the radius of the
sphere into the sine of 45[deg].

{Globular sailing}, sailing on the arc of a great circle, or
so as to make the shortest distance between two places;
circular sailing.
[1913 Webster]


Projection \Pro*jec"tion\, n. [L. projectio: cf. F. projection.]
[1913 Webster]
1. The act of throwing or shooting forward.
[1913 Webster]

2. A jutting out; also, a part jutting out, as of a building;
an extension beyond something else.
[1913 Webster]

3. The act of scheming or planning; also, that which is
planned; contrivance; design; plan. --Davenant.
[1913 Webster]

4. (Persp.) 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.
[1913 Webster]

5. (Geog.) Any method of representing the surface of the
earth upon a plane.
[1913 Webster]

{Conical projection}, a mode of representing the sphere, the
spherical surface being projected upon the surface of a
cone tangent to the sphere, the point of sight being at
the center of the sphere.

{Cylindric projection}, a mode of representing the sphere,
the spherical surface being projected upon the surface of
a cylinder touching the sphere, the point of sight being
at the center of the sphere.

{Globular}, {Gnomonic}, {Orthographic}, {projection},etc. See
under {Globular}, {Gnomonic}, etc.

{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.

{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 containing 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.

{Projection of a straight line of a plane}, the straight line
of the plane connecting the feet of the perpendiculars let
fall from the extremities of the given line.
[1913 Webster]

Syn: See {Protuberance}.
[1913 Webster]
[1913 Webster]