Definition: An orthographic projection of the sphere on the plane of
the meridian, the eye being supposed at an infinite distance, and in
the east or west point of the horizon.
Definition: An instrument of wood or brass, on which this projection
of the sphere is made, having a movable horizon or cursor; -- formerly
much used in solving some common astronomical problems.
Definition: A scale of the sun's declination for each day of the
year, drawn across the torrid zone on an artificial terrestrial globe.
