Astrology Encyclopedia

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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 subtracting from the vector, the cosine of the declination.

The inclination of the Moon's orbit to the ecliptic varies from 4°59' to 5°18'.

 

The Earth's orbit is, of course, the Ecliptic, hence the Sun can have no latitude. That it has declination is due to the fact that the ecliptic makes an angle with the celestial equator of approx. 23°5' - which is described, not as inclination but as the obliquity of the ecliptic. For the inclination of the planets v. Nodes of the Planets.

 

Inconjunct. Dissociate. A planet is inconjunct when it forms no aspect and is not in parallel of declination or mutual disposition to another planet. Dissociate was formerly applied by some authorities to the 150° or Quincunx aspect, which they deemed inconsequential; but is now applied to any two Signs or Houses which have no familiarity with each other - meaning those which bear a twelfth, second, sixth and eighth House relationship, as Taurus, with Aries, Gemini, Libra and Sagittarius.

 

Increasing in Light. Usually said of the Moon, but equally applicable to any planet which, on leaving a conjunction with the Sun, increases in light, as viewed from the Earth; and as it recedes from the opposition, decreases in light.

 

Increasing in Motion. A planet increases its motion by acceleration from day to day as it approaches perihelion. When it is approaching its apogee, the Moon may advance 12° one day and as much as 13° the next. As its mean motion is 13°10' per day, any excess above this indicates that the Moon is "swift in motion." The condition is regarded as fortunate. Older authorities term it increasing in number.

 

Individual Houses. v. Houses.

 

Inferior Planets. The minor planets, those whose orbits are within that of the Earth: viz.: Mercury and Venus. v. Planets.

 

Infortunes. Mars and Saturn. v. Planets, Malefic.

 

Ingress. Said of the entry of any orbital body into a Sign, or a quadrant. The Sun makes an ingress into the Cardinal Signs at the equinoxes and solstices. The planets also have their ingresses into the various Signs, which result in certain alterations of their influence.

 

Initiating Signs. The first Sign of each season of the year; the Cardinal Signs - Aries, Cancer, Libra, and Capricorn, characterized by a constant state of mobilization for action.

 

Initiative Type. Referring to a quality liberally possessed by those born when the Sun was in a leading Sign: Aries, Cancer, Libra, or Capricorn. v. Sign.

 

Injunct. An abbreviated form of inconjunct (q.v.).

 

Inspirational Natures. Referring to the quality of sensory receptivity and reaction that characterizes those born with the Sun in Aries, Leo and Sagittarius - respectively, the initiative, executive and deductive types of the Inspirational group. It would appear that their chief motivation derives from a super-consciousness of the Ego.

 

Intellectual Natures. Referring to a quality of sensory receptivity through the mind that characterizes those born with the Sun in Libra, Aquarius and Gemini - respectively, the initiative, executive and deductive types of the Intellectual group. To classify this group as Intellectuals, does not imply that other groups are possessed of inferior intellects.

 

Interlunar. Of or pertaining to the brief period of time that separates the old and the new Moon. The period of the Moon's invisibility during a lunation, the solar period less 26 d., 18 h., or approximately two days.

 

Intercepted. Said of a Sign wholly contained within a House; or more precisely, of a House which is intercepted by a Sign which does not appear upon either of its cusps. v. House.

 

Interpolation. The process of computing intermediate values in a series of numbers. In astrology it is applied (1) to computing a planet's position for a given moment between two known posi- tions, such as the noon or midnight position prior to and subsequent to the desired moment, as taken from an Ephemeris for that year; and (2) to compute the house cusps for an intermediate latitude between two sets of tables computed for latitudes on either side of that for which the interpolation is required. In making the calculations necessary for an interpolation, use is frequently made of Tables of Diurnal Proportional Logarithms. v. Logarithms.

 

Interpretation. Applied astrologically to an individual judgment as to the significance of a configuration of birth planets, or of transiting or progressed aspects to a birth configuration.

Invariable Plane. The Solar System possesses two fixed planes: that of the Solar Equator; and the Invariable plane - a central plane of the Solar System discovered by Laplace, which, passing through its center of gravity at a mean inclination of about 1°35' to the Ecliptic, is independent of the mutual perturbations of the planets. 
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Inversion. When any Angle which represents an aspect is subtracted from 180°, that which remains is also an aspect, and either is an inversion of the other. Thus: the inversion of a sextile is a trine; of a semi-square, a sesquiquadrate; and so on.

 

Ishtar. v. Venus.

 

Isis and Osiris. Two hypothetical trans-Plutonic planets which have been the subject of much conjecture.

 

Issat. (Izzah, glory; from Arabic.) Applied ironically to one who has delusions of grandeur, or who suffers from an exaggerated appraisal of his prestige.