March 2021 – Rhys Redmond Chatham Astrology

March 28, 2021March 28, 2021

Short versus Long Ascension

In the first time-based house system that we looked at, the Alcabitius system, we carefully measured the time it took for the point of the ascendant (the point where the horizon meets the Sun’s path along the meridian), to reach the culmination point of the Sun at the midheaven, or MC (Medium Coeli).

We then took the total time of the Sun’s path along the ecliptic from the ascendant to the MC and divide the time it took into three equal parts. Adding one of these parts to the time of the ascendant gives us the time when the point of the ascendant reaches the 12^th house cusp, adding the sum again gives us the 11^th house cusp, and we convert those times into degree points on the ecliptic.

The beauty of this system is that it is linked to the local meridian, and thus more directly to the location of the earth-based native of the chart.

With Alcabitius, at first glance it would appear that since time is trisected between the ascendant and the MC, that the time it takes for the Sun (or any planet) to travel would be the same for each of the trisected houses, since each of the houses represent an equal amount of time.

However, this is not the case. And this is where the innovation of the Placidus system enters the picture.

The fact of the matter is that the Sun transverses some astrological signs more quickly than others. This is what William Lilly referred to as “straight signs” versus “crooked signs”. Or put another way, “signs of right ascension” as opposed to “signs of oblique ascension”, or “signs of long ascension” vs “signs of short ascension”.

Because of the way the earth is tilted with respect to the ecliptic, six of the constellations along the ecliptic seem flatter/not as tall/crooked/shorter than the other six, which appear to be standing upright, “straight”, or long.

The Sun takes less time with the crooked/oblique/short signs to “ascend” along the ecliptic than it does with the upright, straight, or long ones.

In the northern hemisphere, the signs of right ascension (straight/upright/long) are: Cancer, Leo, Virgo, Libra, Scorpio and Sagittarius.

The signs of oblique ascension (crooked/oblique/short) are: Capricorn, Aquarius, Pisces, Aries, Taurus, Gemini.

In the southern hemisphere, due to the earth’s tilt of 23.5° in relation to the ecliptic, these are reversed: i.e. the signs of long ascension become the signs of short ascension.

You can easily see for yourself how widely the ascension times vary for each sign in any astrological program capable of animating a chart wheel, such as Astro Gold or Solar Fire. I’ve prepared a demonstration video in Solar Fire to demonstrate this, you can do it yourself at home!

https://vimeo.com/529742941

And here is a lovely YouTube video using Stellarium and Sumer 1.3 by Rumen Kolev which demonstrates the phenomenon of long ascension versus short ascension quite nicely, observe especially the image on the right:

So in summary, Porphyry is an ecliptic-based system which simply divides the ecliptic in three equal parts from the ascendant to the MC, and then again from the MC to the Descendant, and by extension to the rest of the 12 astrological houses.

Alcabitius is a time-based system, which measures the time it takes for the point of the ecliptic to move in a diurnal (primary, literally “to the right”) direction until it reaches the MC. We then divide the time by three (rather than dividing the ecliptic itself). Then we do this operation again from the IC to the ascendant, and by extension the rest of the twelve astrological houses.

Placidus was an innovation, in that it took into account that although the signs are a standardized 30° each on the ecliptic, the Sun moves along these signs at different rates of speed due to their positioning in relation to the local meridian. It is thus a more accurate representation of the size of an astrological house in relation to the native’s position on earth. We do not get this in any of the other previously mentioned house systems.

We will go more deeply into the Placidus system in the next post.

—ooOoo—

March 26, 2021August 9, 2021

Alcabitius House system

We’ve discussed ecliptic-based house systems such as whole sign houses, equal houses and Porphyry. Now I’d like to move on to two of the “time-based” house systems: Alcabitius and Placidus.

Ecliptic systems divide the ecliptic itself into houses. In the whole sign house system (WSH), the astrological sign itself becomes the house, with each sign/house consisting of a standardized 30° of ecliptical longitude. The Ascendant is floating freely within the first house, and the midheaven (M.C.) is generally floating anywhere between the 8^th – eleventh houses.

Ditto for equal houses, except each house starts with the degree of the ascendant.

The Porphyry house system takes the distance from the Ascendant to the midheaven, and trisects it into three equal divisions, which determines the house cusp degrees for houses 10, 11 and 12, and by extension for houses 4, 5 and 6. Then, the longitudinal distance between the midheaven and the descendant is measured and trisected, giving us the degrees of houses 9, 8 and 7, and by extension the degrees for houses 3, 2 and 1. The Porphyry system is the simplest form of “quadrant house system”, so called because it divides the 360° circle of the ecliptic into four quadrants.

Now we come to the Alcabitius system of house division, which is called a “time-based” house system.

So how is Alcabitius time-based? What does this mean?

Consider the ascendant, the astrological point to the East where the horizon meets the ecliptic… This is the point where the Sun rises.

As the earth rotates this point will rise along the diurnal arc (i.e. the ecliptic) until it becomes the midheaven (MC), the point where the Sun culminates (not to be confused with the zenith).

The “time” we are speaking of here is the time it takes for the point of the ascendant to move along the “semi-arc” of the until it reaches the MC, the cusp of the tenth house, where it transverses the local meridian

This amount of time is then trisected in Alcabitius: it is divided into three equal parts, which we refer to as “trisecting the semi-arc of the ascendant”.

Thus, we are trisecting time in the Alcabitius system, as opposed to a system that is dividing solely the ecliptic, such as WSH, equal houses or Porphyry, and all that this implies symbolically (which we shall discuss in more depth a bit later on).

Back to Alcabitius now…

So, let us say that it takes 5 hours, 32 minutes and 16 seconds for the point of the ascendant to rise in a diurnal direction (primary direction) to the midheaven.

All one does is divide that by three, which gives us 1 hour 50.7 minutes. To determine the 12^th house cusp we simply find out what longitudinal degree the ascendant was on at 1 hour 50.7 minutes after the precise hour of the rising point. We double that to find the eleventh house cusp, and to check one’s work we simply multiply by three, and if our calculations were correct, we arrive at the same degree as the midheaven.

Easy, right? At least it is conceptually. It is a beautiful and elegant system which was used widely in Europe from around the 10^th century up until the introduction of the Regiomontanus system in the late 15^th century.

The second and third house cusps are found the same way as the eleventh and twelfth, except rather than moving forward in time, we look back to when the point of the ascendant was at the IC, determine what time this occurred, divide the time it took by three and follow the same procedure for the lower semi arc that we used for the upper one.

One advantage of the Alcabitius system is that there is little less distortion in the relative sizes of the houses. For example, in Placidus – another time-based house system – at the latitude of Paris we sometimes find a huge sixth and twelfth house. In the Alcabitius house system the houses tend to be more evenly distributed, as a general rule.

Chart 1: Placidus (note H6 & H12). Chart 2: Alcabitius.

Indeed, we would probably be using Alcabitius widely today if it had been included in Raphael’s Ephemeris, which was the standard reference for astrologers during the 19^th and well into the 20th century. But alas, it wasn’t; it was Placidus that was included, which goes a long way to explaining the current popularity of Placidus, for astrologers tend to use whatever house system their teachers used. Quite understandable, of course. Though perhaps unfortunate.

In our next discussion, we will look at the Placidus system of house division to see how it is calculated, and compare it with Alcabitius.

—ooOoo—

March 3, 2021December 7, 2022

The three great celestial circles: the ecliptic, the local horizon and the local meridian.

Earlier, we spoke of ecliptic-based house systems (c.f. blog 24 January 2021).

In the course of talking about these older house systems, we are going to look at the ecliptic, the horizon and the meridian, see what they look like in the sky above us, and finally we will look at how they are represented in an astrological chart.

The easiest house systems to calculate are the ones that are based on the ecliptic. The three major house systems based primarily on the ecliptic are: (1) the whole sign house system (WSH), (2) the equal house system, and the (3) Porphyry house system.

These three house systems use as their basis three great celestial circles: the ecliptic, the local horizon, and the local meridian and are easy to calculate. All one needs to know is the longitudinal position on the ecliptic of where the ecliptic meets the horizon, this is called the ascendant.

Then we need to find the point where the ecliptic meets the local meridian, this is called the midheaven.

Once we know these positions, the rest of the calculations can be done in one’s head!

I’d like to introduce a more complex house system, but before we get to that, let’s review the basic celestial circles that we have covered so far: the ecliptic, the horizon and the meridian.

The Ecliptic:

The ecliptic, of course, is the apparent path of the Sun as it is seen from the point of view by an observer on earth.

The five visible planets never drift too far from the path of the ecliptic, so in astrology we usually measure the longitudinal position of the luminaries and planets, including the outer ones, as longitudinal degrees along the 360° circle of the ecliptic, which by convention we divide into twelve sectors of 30° of longitudinal position each. Each of these twelve sectors is represented by an astrological constellation (Aries, Taurus, Gemini, etc.), which may or may not correspond with the ones in the sky.

The Horizon:

The horizon is the great circle on the celestial sphere that is directly between the zenith (the point directly above you) and the nadir (the point directly below you).

The horizon is always perpendicular to the local zenith and nadir, that is to say the horizon is 90° from the ascendant.

The Meridian:

The meridian is the great circle passing through the celestial poles, as well as the zenith and nadir of an observer’s location. In astrology, the midheaven is defined as the point where the ecliptic meets the local meridian.

How the great circles are represented in an astrological chart:

In an astrological chart, we squish these great celestial circles together, we flatten them so that they are represented by straight lines:

The outer circle represents the ecliptic, and on it we see the degrees of the house cusps, which were calculated in Porphyry in this chart.

The vertical line going from left to right, from 5° Leo to 5° Aquarius, represents the horizon, which of course is actually a circle, not a straight line. Because western astrology was developed in the northern hemisphere, the Sun was always to the south. So since the chart assumes that we are facing south, the east is on the left and the west is on the right. This convention has stayed with us through the ages, and we use it today, even if we live in the southern hemisphere.

Finally, the vertical line that goes from the bottom at 15° Libra to the top at A5° Aries represents the local meridian, which of course is also a great circle, and not a straight line (c.f. illustration 3). The point of the midheaven represents the point where the two circles intersect: it is the point of intersection of the meridian with the ecliptic.

The beginning of the tenth house in a quadrant house system such as Porphyry, Alcabitius, Campanus, Regiomontanus or Placidus is called the Medium Coeli (M.C.), which is Latin for midheaven.

The M.C. is where the Sun reaches its highest point in the local sky, NOT to be confused with the zenith, which is the point directly above the observer.

So, to give an example, if one is in the northern hemisphere at a mid-latitude location, for example Wisconsin, or in Europe in France, the Sun would be towards the south as it rises, culminates, and sets. The Sun only passes directly overhead the observer at the equator. The Sun travels along the ecliptic, the local meridian is perpendicular to our local horizon, so basic physics tells us that the Sun will reach its highest point when, travelling along its path on the ecliptic, it meets our local meridian.

Our local zenith is also on our local meridian, it is directly above where one is standing. But the local zenith is not on the path of the ecliptic, unless we happen to be standing exactly on the equator!

Having reviewed these three basic circles, in the next blog I hope to cover later astrological house systems. The next one we will cover is the Placidus house system.

—ooOoo—