3-Systems of House Division
Systems of House Division
It is certainly true that houses are purely a symbolic description of the
heavens, whereas the positions of the stars and the planets are measurable
concrete things. Which System should you Use?: Who knows? no one appears
to have done a study as to which gives the most accurate prediction. If
you wish to choose based on popularity, Placidus, Koch and Equal House are
the most common systems for modern Western individual astrology.
Placidus
This is the most commonly used house system in modern Western astrology. Placidus
remains the most popular system among English-speaking astrologers The Placidus
system is sometimes not defined beyond polar circles (latitudes greater than 66°N
or 66°S), because certain degrees are circumpolar (never touch the horizon), and
planets falling in them cannot therefore appear in the Birth Chart. This is the
main weakness of the Placidean system according to its critics, which often cite
the exceptional house proportions in the higher latitudes.
Michel Gauquelin divided Placidus
houses into 36 (instead of 12) "decans" and marked beginning of the 36th
"decan" (the first before ascendant) as the starting point.
Koch
[Time-based] [Second most commonly
used system in Western Astrology] A rather more complicated version of the
Placidus system, built on equal increments of Right Ascension for each quadrant.
The Koch system is defined only for latitudes between 66°N and 66°S. This system
is popular among research astrologers in the U.S. and among German speakers, but
in Central Europe lost some popularity to the Krusiñski house system.
Topocentric
This is a recent system, invented in Argentina, that its creators claim
has been determined empirically, i.e. by observing events in people's
lives and assessing the geometry of a house system that would fit. The
house cusps are always within a degree of those given in the Placidus
system. The geometry is somewhat complicated and the reader is referred to
this site for an explanation. The topocentric system can also be described
as an approximation algorithm for the Placidus system.
Topocentric: [Time-based] This
system was introduced in 1961 by Wendel Polich and A.P. Nelson Page. Nor is
this house system more “topocentric” (i.e. birth-place- related) than any other
house system. (c.f. the misunderstanding with the “birth place system”.) The
“topocentric” house cusps are close to Placidus house cusps except for high
geographical latitudes. It also works for latitudes beyond the polar circles,
wherefore some consider it to be an improvement of the Placidus system. However
the striking philosophical idea behind Placidus (i.e. the division of diurnal
and nocturnal arcs of points of the zodiac) is completely destroyed.
Systems of House Division
There are many systems of house division. In most the ecliptic is divided
into houses and the ascendant (eastern horizon) marks the cusp, or beginning,
of the first house, and the descendant (western horizon) marks the cusp of the
7th House. Many systems of house division called quadrant house systems also use
the mid-heaven (medium coeli) as the cusp of the 10th House and the nadir (imum
coeli) as the cusp of the 4th House. Some house systems divide the celestial
equator and the prime vertical instead of the ecliptic.
The earliest systems (whole sign and
equal house) linked the houses to the signs of the zodiac. The equal house system
defines houses as 30-degree sectors of the ecliptic, so that the cusp of each house
falls on the same degree of each zodiac sign. One outcome of this is that a varying
angle occurs between the ascendant and mid-heaven in higher latitudes. Attempts
to reconcile the concept of "quadrants" with the varying angle between
mid-heaven and ascendant lead to more complicated house systems. These became more
relevant as astrology spread from subtropical regions to higher latitudes.
Goals for a house system include
ease of computation; agreement with the "quadrant" concept (ascendant
on the 1st House cusp, nadir on the 4th House, descendant on the 7th, and mid-heaven
on the 10th); defined and meaningful behavior in the polar regions; acceptable
handling of heavenly bodies of high latitude (a distinct problem from high-latitude
locations on the Earth's surface); and symbolic value. It is impossible for any
system to satisfy all the criteria completely, so each one represents a different
compromise. The extremely popular Placidus and Koch systems, in particular, can
generate undefined results in the polar circles. Research and debate on the merits
of different house systems is ongoing.
Early Forms of House Division
The earliest forms of house division were those that link with, or run
parallel to, the signs of the zodiac along the ecliptic. Proponents of the
equal house system claim that it is more accurate and less distorting in
higher latitudes (especially above 60 degrees) than the Placidean and
other quadrant house systems.
Whole Sign System or Bhaav System
In the whole sign house system, sometimes referred to as the 'Sign-House
system', the houses are 30° each. The ascendant designates the rising
sign, and the first house begins at zero degrees of the zodiac sign in
which the ascendant falls, regardless of how early or late in that sign
the ascendant is. The next sign after the ascending sign then becomes the
2nd house, the sign after that the 3rd house, and so on. In other words,
each house is wholly filled by one sign. This was the main system used in
the Hellenistic tradition of astrology, and is also used in Indian astrology,
as well as in some early traditions of Medieval astrology. It is thought to
be the oldest system of house division.
The Whole Sign system was originally
developed in the Hellenistic tradition of astrology sometime around the 1st or 2nd
century BCE, and from there it was passed to the Indian and early Medieval traditions
of astrology. At some point in the Medieval period, probably around the 10th century,
whole sign houses fell into disuse in the western tradition, and by the 20th century
the system was completely unknown in the western astrological community, although was
continually used in India all the way into the present time. Beginning in the 1980's
and 1990's the system was rediscovered and reintroduced into western astrology.
Equal House System
In the equal house system the ecliptic is also divided into 12 equal divisions of 30 degrees,
although the houses are measured out in 30 degree increments starting from the degree
of the ascendant. It begins with the ascendant, which acts as the 'cusp' or starting
point of the 1st house, then the 2nd House begins exactly 30 degrees later in zodiacal
order, then the 3rd House begins exactly 30 degrees later in zodiacal order from the
2nd House, and so on.
The distinction between equal houses and
whole sign houses lies in the fact that in whole sign houses the cusp of the 1st house
is the beginning of the sign that contains the ascendant, while in equal houses the
degree of the ascendant is itself the cusp of the 1st House.
The MC in Whole Sign and Equal House Systems
In the whole sign and equal house systems the Medium Coeli (Midheaven), the highest
point in the chart, does not act as the cusp or starting point of the 10th house.
Instead the MC moves around the top half of the chart, and can land anywhere in the
8th, 9th, 10th, 11th or 12th Houses, depending on the latitude. The MC retains its
commonly agreed upon significations, but it doesn't act as the starting point of the
10th House, and instead it functions more like a sensitive point in the chart such as
the 'vertex' or the 'lot of fortune'.
This is also the more common criticism
of the whole sign and equal house method as it concerns the location of the Medium
Coeli (Midheaven), the highest point in the chart. In the equal house system, the
ascendant/descendant and mid-heaven/nadir axes can vary from being perpendicular to
each other (from approx. +-5 deg at most at equator to approx. +-15 degrees at Alexandria
to +-90 degrees at polar circle). As a result, equal houses counted from the ascendant
cannot in general place the mid-heaven on the tenth house cusp, where many feel it would
be symbolically desirable. Since this point is associated with ambition, career, and public
image, the argument is that the Mid-heaven, therefore, must be the cusp of the similar tenth
house. It has also been linked by extension with Capricorn (the tenth sign of the zodiac)..
Because the Whole Sign and Equal House system do not take the Mid-heaven into account, but
relies on the location of the Ascendant, it can be found anywhere between the 8th and 11th
houses.
Quadrant House Systems
Quadrant house systems divide the houses so that they agree with the "quadrant"
concept (ascendant on the 1st House cusp, nadir on the 4th House, descendant on the 7th
House, and mid-heaven on the 10th House).
Porphyry
Each quadrant of the ecliptic is divided into three equal parts between the four angles.
This is the oldest system of quadrant style house division. Although it is attributed to
Porphyry of Tyros, this system was first described by the 2nd century astrologer Vettius
Valens, in the 3rd book of his astrological compendium known as The Anthology.
Alchabitius
The predecessor system to the Placidus, which largely replaced the Porphyry. The difference
with Placidus is that the time that it takes the Ascendant to reach the meridian is divided
equally into three parts. The Alchabitius house system was very popular in Europe before the
introduction of the Regiomontanus system. Alchabitius (or Alcabitius), was a 10th century
Arabian astrologer (d. 967).
Regiomontanus
The celestial equator is divided into twelve, and these divisions are
projected on to the ecliptic along great circles that take in the north
and south points on the horizon. Named after the German astronomer and
astrologer Johann Müller of Königsberg. The Regiomontanus system was later
largely replaced by the Placidus system.
Meridian
Similar to Regiomontanus, except that the east point is taken as the Ascendant.
Placidus House System
This is the most commonly used house system in modern Western astrology.
The Placidus system is based on a division of time rather than space. The
times taken for each degree of the ecliptic to rise from the nadir to the
ascendant, and from the ascendant to the mid-heaven, are trisected to
determine the cusps of houses 2, 3, 11, and 12. The cusps of houses 8, 9,
5 and 6 are opposite these. The Placidus system is sometimes not defined
beyond polar circles (latitudes greater than 66°N or 66°S), because certain
degrees are circumpolar (never touch the horizon), and planets falling in
them cannot therefore appear in the Birth Chart. This is the main weakness
of the Placidean system according to its critics, which often cite the
exceptional house proportions in the higher latitudes.
It is thought the Placidus system
was first mentioned about 13th century in Arab literature, but the first confirmed
publication was in 1602 by Giovanni Antonii Magini (1555-1617) in his book "Tabulae
Primi Mobilis, quas Directionem Vulgo Dicunt". Later it was popularized by Catholic
Church as an argument for Ptolemy's geocentric theory of the Solar System, in the
campaign against the heliocentric theory. Placidus, a professor of mathematics, was
named as its author to give it credibility to his contemporaries. Placidus remains the
most popular system among English-speaking astrologers.
Campanus
The prime vertical (the great circle taking in the zenith and east point
on the horizon) is divided into twelve, and these divisions are projected
on to the ecliptic along great circles that take in the north and south
points on the horizon. It is named after Johannes Campanus.
Koch
A rather more complicated version of the Placidus system, built on equal
increments of Right Ascension for each quadrant. The Koch system is
defined only for latitudes between 66°N and 66°S. This system is popular
among research astrologers in the U.S. and among German speakers, but in
Central Europe lost some popularity to the Krusiñski house system.
Topocentric
This is a recent system, invented in Argentina, that its creators claim
has been determined empirically, i.e. by observing events in people's
lives and assessing the geometry of a house system that would fit. The
house cusps are always within a degree of those given in the Placidus
system. The geometry is somewhat complicated and the reader is referred to
this site for an explanation. The topocentric system can also be described
as an approximation algorithm for the Placidus system.
Neo-Porphyry
The Neo-Porphyry system of house division is similar to Porphyry houses
except that instead of each quadrant being divided into three equal sized
houses, the middle house in each quadrant is compressed or expanded based
on the whether the quadrant covers less than or greater than 90 degrees.
In other words, houses are smooth around the zodiac with the difference in
quadrant sizes being spread in a continuous sinusoidal manner from expanded
to compressed houses. Neo-Porphyry houses were invented and first published
by Walter Pullen in his astrology program Astrology in 1994.
Krusinski
A recently published (1995) house system, based on a great circle passing
through the ascendant and zenith. This circle is divided into 12 equal
parts (1st cusp is Ascendant, 10th cusp is zenith), then the resulting
points are projected to the ecliptic through meridian circles.
The house tables for this system
were published in 1995 in Poland. This house system is also known under the name
Amphora in the Czech Republic, after it was proposed there by Milan Píša after the
study of Manilius's "Astronomica" under this name ("Konstelace è.
22" in: "AMPHORA - nový systém astrologických domù" (1997) and in
the booklet "Amphora - algoritmy nového systému domù" (1998)).
Rulership of the House
In Hellenistic, Vedic, Medieval and Renaissance astrology each house is ruled by the
planet that rules the sign on its cusp. For example, if a person has the sign Aries
on the cusp of their 7th house, then the planet Mars is said to "rule" their
7th House. This means that when a planet is allotted a House, its nature comes to have
some bearing on that specific topic in the person's life, and that planet is said to be
very important for events specifically pertaining to that topic. The placement of this
planet in the chart will have at least as much influence on the chart as the planets
within the house. In traditional Western & Hindu astrology, each sign is ruled by
one of the 7 visible planets (note that in astrology, the Sun and Moon are considered
planets, which literally means wanderers, i.e. wandering stars, as opposed to the fixed
stars of the constellations).
In addition, some modern
astrologers who follow the planet=sign=house doctrine, which was first
taught by Alan Leo in the early part of the 20th century, believe that
certain houses are also "ruled" by, or have an affinity with,
the planet which rules the corresponding zodiacal sign. For instance, Mars
is ruler of the 1st house because Aries is the first sign, Mercury rules or
has an affinity with the 3rd house because Gemini is the 3rd sign, etc. This
is sometimes referred to as "natural rulership", as opposed to the
former which is sometimes called "accidental rulership".
Rationale Behind the 12 Houses
Babylonians started observing natural phenomena connected with ascending and culminating
of the heavenly bodies. This evolved into 12 division system of houses before the discovery
of the ecliptic. Later (around 5th century BCE) ecliptic was discovered (Schmidt&Hand
"On the invariance of tropical Zodiac" and "Early house divisions in the
Hellenistic era"). At the beginning this early zodiac it has no sign divisions, and
only 18 bright stars were used as markers to measure planet positions.[citation needed]
Later in Alexandria astrologers introduced the twelve signs to fit the number and probably
meanings of the houses, and named constellations after them. Nowadays, practising astrologers
use a 12 house division. Most theoreticians attribute 8 fold division for misinterpretation
of old texts only, but one theoretician Patrice Guinard [1] has argued, contrary to that
prevailing opinion, that there is a basis for an 8 house division. One prominent astrologer,
Marc Penfield, uses 8 houses - dividing each quadrant using the same technique as in Koch
& Placidus. Michel Gauquelin divided Placidus houses into 36 (instead of 12) "decans"
and marked beginning of the 36th "decan" (the first before ascendant) as the starting
point.
Development of House Systems in Astrology after Classical Astrology
Definition:
[Astrological Houses] The development of Houses and Houses Systems since Classical times.
Houses and house systems seem to have taken a long and obscure road since the time of the
early Classical Astrologers. Nowadays, some astrologers ignore houses completely as being
too tainted by uncertainty to use. In this they follow the tradition of Claudius Ptolemy,
the "Father of Classical Astrology", who in his seminal work, Tetrabiblos, appears
to have had little time for houses at all. He ignores them, from which fact various astrological
commentators have concluded that he considered houses meaningless mysticism. It is certainly
true that houses are purely a symbolic description of the heavens, whereas the positions of
the stars and the planets are measurable concrete things.
For others of us, houses remain very important.
This presents us with a problem, as unfortunately, in modern times, three classes of house
system exist: ecliptic-based, time-based and space-based and these yield at least twenty methods
of calculating the astrological houses on the Zodiac Wheel. In these different house systems
the planets can appear in different houses: the planets aren't moving but the placement of each
house is different in the various systems. [See for example how the different choice of modern
house system changes the spread of planets in houses for Prince William.] Hence for those of us
committed to the modern houses, the choice of house system can radically alter a horoscope.
History:
The most commonly used house system at present, the Placidus system was not that used by
the Classical originators of astrology. In fact, it appears that there were three separate
house systems in classical astrology: Temples Cardinal Points and Quadrants, and Lots. Over
the last two millennia the fashion in house systems has gone through Alcabitus, Regiomontanus
and now Placidus. And sadly this appears to be little more than fashion. It is also unfortunately
true that an astrologer's preference for a particular house system is often based on how good
our own chart looks with that house system. And that our clients - given the choice - often pick
their chart using the house system that gives them the best chart. Not a very rigorous, nor
truthful, method of casting a horoscope. In fact the lack of a rigorous choice of house system is
one of the most fundamental problems in modern astrology. I would add to this that the divergence
of our house systems from those of the Classical astrologers, also gives great cause for concern.
Which System should you Use?:
Who knows? It is rumored that one particular national meeting of astrologers descended into a
fist-fight trying to resolve this question! I have yet to see a rigorous test of the house systems:
no one appears to have done a study as to which gives the most accurate prediction. If you wish
to choose based on popularity, Placidus, Koch and Equal House are the most common systems for
modern Western individual astrology. All three start with the Ascendant on the cusp of the 1st House.
In Placidus and Koch, the Midheaven is then the cusp [start] of the 10th House. But there is no
requirement for this in the Equal House system. The Equal system has cusps which are generally
completely dissimilar to Placidus and Koch. In turn, Placidus and Koch differ in the cusps of the
2nd, 3rd, 5th, 6th, 7th, 8th, 9th and 12th Houses. In both Placidus and Koch some Zodiac signs may
never appear on a cusp, because of the variable house size. The more northerly the latitude in which
you were born the more likely this is to happen. In contrast for the Equal system all signs will
appear on a cusp.
To be honest, the more I have
studied house systems the more I think that none of the above should be
used. I think we should return to the Temples, Cardinal Points and Quadrants
and Lots system that we appear, inexplicably, to have moved away from over the
centuries. Classical astrologers used these three systems - basing their work
on several hundred years of astrology; by what right do we think we should be
doing something different?
Newspaper Horoscopes:
For these a variation of the Sun system is used. The Sun's position is used to mark the
first house, with the first house being placed identically to the zodiac sign. The house
sizes are equal. This is a completely invalid approach, only making even a poor approximation
to a standard horoscope for the one-twelfth of people born in that sign with that sign as their
Ascendant. Worthless... but fun...
House Systems:
Alcabitus [or Alchabitius or Alcabitius or Alcibitius or Alcabitius Declination] :
[Time-based] [The standard house system in the late Middle Ages] This method of house
division first appears in a treatise written by Rhetorius, the Egyptian (505 AD) entitled
From the Treasury of Antiochus, an Explanation and Narration of the Whole Art of Astrology.
The system was attributed to Abu al-Saqr al-Qabisi Abd al-Aziz ibn Uthman (d. 967) also
known as Alcabitius [and variant spellings], the author of the Introduction to the Art of
Judgments of the Stars (c. 916-967). Although this system was presented by various other
Arabic writers of the time, Alcabitius' text was translated into Latin by John Seville in
the 12th century and by Erhard Ratdolt in Venice in 1503, thus helping to popularize the
method.
The Midheaven and Ascendant are respectively
the 10th- and 1st- house cusps.. The remaining cusps are determined by the trisection of
the semidiurnal and seminocturnal arcs of the Ascendant. The houses are formed by the lunes
created by the true house circles that pass through these cusps and the North and South points
of the Horizon. This varies from other quadrant systems, in which the trisection occurs along
the ecliptic. Unlike the Placidus system it works well in the polar regions. One author notes
that the method is a "logical development from the Porphyry system" since that method
trisects the semi-arc of the ecliptic while this one trisects the diurnal arc and projects it
onto the ecliptic by means of hour circles.
The "Classical House" [Time-based]
system is a variation on this, incorporating Ptolemy's five degree correction. The diurnal
arc of the Ascendant is tri-sected and projected by hour circles onto the ecliptic to form
the house cusps, but five degrees is subtracted from the Ascendant to form the first house
cusp. This is a modern, slight correction to the Alcibitius Declination house system, despite
its name.
Campanus:
[Space-based] Named after Giovanni di Campani (1233-1296). The vertical
great circle from east to west is divided into 12 equal parts and great
circles are drawn through these divisions and the north and south points
on the horizon. The intersection points of these circles with the ecliptic
are the house cusps. Thought by some authors to be the same system as that
used by Al-Biruni in the 11th century under the name 'the system of Hermes'
and perhaps that used by Marcus Manilius in his work, Astronomica, dated 10 AD -
though as this latter is a poem it makes interpretation highly problematical.
Used by Dane Rudhyar and Charles Zane in modern times.
Equal:
[Ecliptic-based] [Third most commonly used system in Western Astrology]
The zodiac is divided into 12 houses of 30 degrees each starting from the
Ascendant. Note that in this house system the Midheaven is not necessarily
the cusp of the tenth house. This system is reputed to have the oldest
pedigree, as some authors state that it is the system used by Ptolemy.
Others state it dates back to the time of Petosiris (1st century, BC).
This would be consistent with the lack of status for the Midheaven, which
was not considered important in early classical astrology.
Earth House:
Zero degrees of Libra is taken as the first house cusp and each house cusp
is thirty degrees farther along in the zodiac.
Horizontal;
The house cusps are defined by division of the horizon into 12 directions.
The first house cusp is not identical with the Ascendant but is located
precisely in the east.
Koch/GOHS:
[Time-based] [Second most commonly used system in Western Astrology] This
system is named for its advocate German astrologer Walter Koch (1895-1970)
. It was invented by Fiedrich Zanzinger and Heinz Specht. In German-speaking
countries, it is also called the "Geburtsorthä usersystem" (GOHS),
i.e. the "Birth place house system". This name was coined by Walter
Koch following his belief that the Koch system was more related to the birth
place than other systems. He believed this, because all house cusps in this
system are calculated with the same polar height, the "polar height of
the birth place": this has the same value as the geographic latitude.
With the Koch system, the house cusps
are in fact defined by horizon lines at different times. To calculate the cusps 1th1
and 12th, one can take the time it took the Midheaven degree to move from the horizon
to the culmination, divide this time into three and see what ecliptic degree was on the
horizon at the thirds. Why Koch thought this procedure should be more related to the
birth place remains obscure.
Mid-heaven:
The Midheaven (Midheaven) is taken as the cusp of the tenth house and each
house is thirty degrees further along in the zodiac. Note that in this
house system the Ascendant is not necessarily the cusp of the first house.
Meridian or Vehlow-Equal or Zariel:
The Meridian house system was proposed by the Australian astrologer Zariel (David Cope)
in the early 1900s. It has never received much attention, but was investigated by American
astrologers Bruce Lloyd and Garth Allen in the late 1950s. This system is also referred to
as the "Axial Rotation System," a term which is somewhat misleading, as no rotation
is involved, but derives from the use of the North and South Celestial poles for the construction
of the great circles. Circles are drawn through the poles and twelve points that divide the
equator equally, starting at the meridian. These points are then projected onto the ecliptic.
The Mid-heaven is identical to the 10th house cusp. The Ascendant is not equal to the 1st cusp,
but is equivalent to the so called "East Point" or equatorial ascendant. This system
works in extreme latitudes [the poles]. The Meridian house system is most popular with Uranian
astrologers.
Moon:
The Moon is taken as the 10th House cusp and each House cusp is 30 degrees farther along
in the zodiac. Note that in this house system neither the Ascendant nor the Midheaven are
necessarily house cusps.
Morinus:
[Space-based] Named after Jean-Baptiste Morin (1583-1656), known as Morinus. The
Morinus system uses great circles that pass through the poles of the ecliptic and
through points that are spaced at 30-degree intervals along the Celestial Equator,
beginning with the intersection of the Celestial Equator and the East Point. The
cusps are determined by the intersections of these great circles and the ecliptic.
The houses are not of equal size. The Midheaven is not the same as the 10th cusp.
The Ascendant is not the same as the 1st cusp. This system is unusual in this respect,
that it doesn't begin with the Ascendant but with true East. [The Ascendant is often
not at true East.]
Natural Graduation:
A complicated mathematical variation of the Porphyry House System, as described on pp.
46- 47 in "New Waite's Compendium" by Colin Evans.
Natural Hours:
[Time-based] The times of sunrise and sunset are noted for the location
and date of the horoscope. The degrees of the Ascendant at Sun rise and
Sun set give the degrees of the Ascendant and descendant respectively. The
hemispheres between the Ascendant and Descendant are divided into six
sectors, each representing two 'hours' of time. These sectors also give
the house cusps. Note that the Ascendant and descendant are no longer tied
together as a pair in this system, and the Mid-Heaven may fall in any house.
Octopos:
The prime vertical is cut at 45 degree intervals starting at the east point of
the horizon, and these points are projected onto the ecliptic using house circles. This
produces eight houses instead of twelve as by most other systems, and these are then
numbered starting at the descendant and going counter-clockwise, so that the house placed
at the seventh house is called the first house, and the house normally near the ninth house
is the second house, etc. For those persons with a fear of the twelfth house, this is the
one to use.
Placidus or Placidian:
[Time-based] [Most commonly used system in modern Western Astrology, not through any particular
merit but because, as is widely accepted, it was the one for which affordable data tables were
available in the 19th century.] This system is named after the Italian monk Placidus de Titis
(1590-1668) and was found in his work Primum Mobile. The cusps are defined by divisions of
semidiurnal and semi-nocturnal arcs. The 11th cusp is the point on the ecliptic that has completed
2/3 of its semidiurnal arc, the 12th cusp the point that has completed 1/3 of it. The 2nd cusp has
completed 2/3 of its semi-nocturnal arc, and the 3rd cusp 1/3. Some authors argue that this rather
than the Equal house system is closer to the original Ptolemaic ideal. I find this unlikely as this
is a time-based system whereas Ptolemy probably thought in terms of an ecliptic system. It may also
be an attempt to justify is current dominant position by referring it back to the wellspring of
astrology. However it is an elegant system.
Polich-Page or Topocentric:
[Time-based] This system was introduced in 1961 by Wendel Polich and A.P. Nelson Page. The
tangents of the polar height of the 11th house is the tangents of the geo. latitude divided
by 3. (2/3 of it are taken for the 12th house cusp.) The philosophical reasons for this algorithm
are obscure. Nor is this house system more “topocentric” (i.e. birth-place-related) than any other
house system. (c.f. the misunderstanding with the “birth place system”.) The “topocentric” house
cusps are close to Placidus house cusps except for high geographical latitudes. It also works for
latitudes beyond the polar circles, wherefore some consider it to be an improvement of the Placidus
system. However the striking philosophical idea behind Placidus (i.e. the division of diurnal and
nocturnal arcs of points of the zodiac) is completely destroyed.
Porphyry:
[Ecliptic-based] Attributed to a Neo-Platonist named Porphyry (233-c.304),
a Greek philosopher and student of Plotinus. Porphyry is best known for
his work Introduction to Ptolemy's Tetrabiblos, which is essentially an
encyclopedic dictionary of astrological terms and techniques. In chapter
43 entitled Determination of the Angular, Cadent, and Succedant Houses to
the Degree, Porphyry shows how the cusps are derived by trisecting the
semi-arc between the Ascendant and Mid-heaven. The Porphyry system seems
to be used in at least some 'Vedic' Jyotish Indian astrology.
After the Ascendant and
Mid-heaven ecliptic positions have been calculated, the semi-arc between
them is computed by subtracting one from the other. This semi-arc -- which
represents one quadrant of the chart -- is then divided by 3 to determine
the arc of each of the intermediate houses. This constant is then added to
the Mid-heaven to yield the cusp of the 11th house, to the 11th to yield
the cusp of the 12th, and to the 12th to confirm the Ascendant degree. The
cusps of the 4th and 7th houses will be 180 degrees from the Ascendant and
Mid-heaven respectively and opposite in Zodiacal sign. The same quadrant
arc division process is applied to the northeastern, northwestern, and
southwestern quadrants of the chart to yield the cusps of houses 2, 3, 5,
6, 8, and 9. Because this process yields the same constant in each quadrant
arc division, house cusps 11 and 5; 3 and 9; 2 and 8; and 6 and 12 will be
180 degrees apart. Also Houses No 11 and 3, 9 and 5 will be 120 degrees apart;
Houses No 12 and 2, 8 and 6 will be 60 degrees apart.
Some authors note that the
first appearance of a description and explanation of this method is made
by Vettius Valens (150-175 AD) in Book III, Chapter 2 of his Anthology
entitled The Authentic Degrees of the Angles. Valens himself attributes
this method to an otherwise unknown astrologer named Orion.
Regiomontanus:
[Space-based] [The standard house system in the later Middle Ages, it supplanted the
Alcabitus system.] Named after the Johannes Müller (called "Regiomontanus",
because Müller came from Königsberg). The equator is divided into 12 equal parts and
great circles are drawn through these divisions and the north and south points on the
horizon. The intersection points of these circles with the ecliptic are the house cusps.
(1436-1476).
Solar:
The position of the Sun is taken as the 1st House cusp and each house cusp is
30 degrees farther along in the zodiac. Note that in this house system neither
the Ascendant nor the Mid-Heaven are necessarily house cusps. This system is
commonly used when the Ascendant and Mid-Heaven are not known. It is therefore
commonly used in newspaper astrology where a horoscope is being produced for
everyone of a certain Sun-sign.
Sun:
The Sun is taken as the 4th House cusp and each house cusp is 30 degrees farther along
in the zodiac. Note that in this house system neither the Ascendant nor the Midheaven
are necessarily house cusps.
Topocentric: See Polich-Page.
Vehlow An equal house system promulgated by Johannes Vehlow (born in 1980, Germany).
Zariel: See Meridian.
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