The wheel or map is the basic structure that a horoscope is fitted into. It is a 360º circle — all circles are 360º, a simple round sphere. This circle is then divided into twelve parts, one part for each sign of the zodiac. There are twelve signs.
Depending upon the house method you use, read this article for the many variations, the divisions can be larger, smaller or equal to the standard thirty-degrees. Whether or not there is an inner circle telling you the house numbers i.e. 1-12 is up to the astrologer. Some use the area to draw the aspects instead of having them in a table on the side — it helps to save spece. While others just put the signs onto a map below.
Hellenistic Astrologers divided the wheel via the whole house system, each house is exactly thirty degrees and starts at zero, further into “faces” or what was later called decan. These “faces” were then broken down into triplets — ten degrees each of a sign that worked well when each house is exactly thirty degrees. That is problematic when you have unequal houses as your ability to use the face-decan system gets abbreviated and faces show up in the next house. Whether you use the whole house or not, when using Greek face-Arabic decan system, always use the equal setup,. most software allows this though $250.00 Janus 5 and $69.00 WinStar Express do not.
The need for an ephemeris
Then we cast a cast using the astral ephemeris, which is another table separate from the horoscope map, of the calculated positions of the astronomical objects for a specific time of the day — these days this is either noon or midnight which is why the default for an unrectified chart is noon.
Ephemerides date back to Babylonia and were useful to early navigators and astronomers, The first national astronomical ephemeris, Connaissance de Temps, was published in France in 1679 but was wildly inaccurate because of their method of calculating longitude –because of Prime Minister’s argument with Jean-Baptiste Morin (1583-1656 AD) they would not adopt his method, despite its accuracy. It was then eclipsed in 1767 when Britisher Benjamin Harrison discovered a method for calculating longitude and the Nautical Almanac and Astronomical Ephemeris was published by the Royal Observatory in Greenwich England, hence Greenwich Mean time.
The date, time and place all factor into the house and planet placement. Below is an example, of the same time and date (12 noon, St. Patrick’s Day) and three different locations: blue for Sydney Australia, green for Galway Ireland and white for New Jersey, USA.
For simplicity’s sake we are using only the ten current planets.
How the houses fall
Follow the lines on the picture below and the various colours uniting the pairs. In every every chart,
- Gemini is always opposite Sagittarius,
- Cancer is always opposite Capricorn
- Virgo opposite Pisces,
- Aquarius opposite Leo,
- Taurus opposite Scorpio and Aries opposite Libra.
This does not mean that every chart will start with Aries and go around in the same order as below, because the start part of a chart changes depending upon the person’s birth time and location of birth that combined create the Ascendant. By convention, the first house is the Ascendant, because that was the sign that was rising at the time of the person’s birth though we disagree with that theory. Rising is always considered to be in the East. The descendant or the cusp of the Seventh house, is always opposite the the rising first house, whether or not the ascendant is found there.
Above, following the coloured lines are the opposites of each house. No matter what the house system this is always true, though the house system will make some look “off” centered.
Plotting the Houses on the Wheel
The aforementioned chart with its many coloured lines show how the information from the longitude is mapped onto the circular wheel. On our map there is a box that tells you where each of the signs falls, a term that means where on the wheel the sign is. Looking at the box, highlighted below, we see that the Sun is in the Tenth house and in the sign of Aquarius.
The Ascendant for our weekly chart is at 12 noon in Boise, Idaho. In the chart above, a whole house setup, this makes it appear in Taurus in the second house. Neptune is in Pisces in the Eleventh house. If this was the 90 dial, then the planets would be mapped by their “modality” (cardinal fixed or mutable) as that dispenses with house placement.
The natural question is that most think that ascendants and times are only viable for natal charts, while we are using it for a mundane chart. That is inaccurate as everything must start and finish at a certain time and most importantly, without a time we cannot create a chart. Both places, events and people have times they are born, happen, or are created and that is why astrology can make a chart for anything that happens.
Looking at the table above you can now create your own map and put the various planets on the wheel.
While this lesson will not make you an astrologer, you can now read a horoscope chart and map the various zodiacal place settings. It is the an propitious beginning.