I

Ides. A day in the Roman calendar and seven days before it. It appears that the term applied
to the day on which the Sun passed the points of the Equinoxes and the Tropics, and that the
seven days constituted the orbs preceding the Sun's crossing of the cusps of the four cardinal
signs or angular houses. Shakespeare refers to the baleful influence of "The Ides of March" -
evidently the last seven degrees of Pisces, or of the Twelfth House.

Illumination, Period of. That portion of the Moon's orbit, of the duration of approximately
26d 18h, during which it is visible, supplying light after sunset and before sunrise. Obviously
it supplies light only to the hemisphere which is turned in its direction; but since the Earth's
rotation constantly shifts this hemisphere, the whole of the Earth's surface is illuminated for
some portion of every night during this period.

Immersion. Applied to the Sun or Moon as it enters into an eclipse, or to the beginning of an
occultation (q.v.).

Impeded; Impedited. Said of a Luminary or planet when badly aspected, especially by the
malefics. Also said of the Moon when passing to a conjunction, square or opposition to the
Sun, Mars, or Saturn. The Moon when impedited by the Sun at birth was anciently said to
produce a blemish in or near the eye.

Imperfect Signs, Broken Signs. Leo, Scorpio and Pisces. v. Signs.

Imum Coeli. The lowest heaven, the North Angle or cusp of the fourth house. v. Midheaven;
Celestial Sphere.

Inclination. (1) Astrologically, the motion of a body toward a position in the horoscope other
than the one it held at birth. (2) Astronomically, the angle at which the orbit of a planet
crosses another orbit, particularly the ecliptic. A point in an orbit is reduced to the ecliptic by