16
In the post concerning the mystery chart Tom points out that Solar Fire seems to calculate primary directions using mundo primaries. I learned to calculate basic primaries from Rumen Kolev?s booklets (available from astroamerica.com) a couple of years ago ? I recommend those booklets warmly, clear explanations, clear pictures, it seems frightening at first, but when you dwell on it, Kolev guides you by hand.

I calculated mundo directions by hand and compared my results with Solar Fire Primary Mundane Directions and they were the same. I have now a demo version of Janus 3 on my computer and I compared the directions by Janus with those of Solar Fire and the results were fairly different! I don?t know what?s the method in Janus, but it?s different from Solar Fire and from Kolev. I suppose Janus is calculating zodiacal directions?

Kolev writes:
?What the programmers of these programs and their dealers (in good faith) called primary directions had nothing to do with the real primary directions employed by Placidus, W. Lilly, Tycho de Brahe, Alan Leo, Kuehr and the other authorities on the subject. (?) But what these modules actually do, most often, is some kind of pseudo-primaries. One of them. For example, moves the planets along their primary paths in right ascension (with 1 degree per year) and projects them on the ecliptic.?
Quite strong words :shock: . Now, I don?t known which methor Robert Zoller teaches, neither have I familiarized myself with Lilly?s method, and I don?t know what?s ?right?. But I would like to know the techical difference between Janus and Solar Fire directions.

17
I haven't read Kolev but it sounds like he understands primary directions. I use Solar Fire and am not familiar with Janus 3. Here is the explanation that Solar Fire gives of its primaries:

"Primary Mundane Directions

Primary directions are created by the diurnal rotation of the earth about its own polar axis. Hence each planet or chart angle is directed along its own diurnal arc, starting from its natal position. Each degree of rotation is deemed to correspond to 1 year in the life of the individual. Aspects are deemed to be formed between directed and natal planets when their relative positions in their diurnal arcs are in angular relationship. (Note that this is quite different from aspects of zodiacal longitude.). For example, if the Sun is natally situated in the 10th house at 90% along its arc from its rise to its culmination, then Saturn will be in natal mundane square to it when it is directed to a position in the 1st house which is at 90% along its arc from its nadir to its rise across the horizon. If this occurs after Saturn has been directed by 24.5 degrees along its diurnal arc, then it is deemed that directed Saturn makes a mundane square to the Sun when the individual is 24 and a half years old.

This method is also known as "Placidian" directions as apparently practiced by Ptolemy, Alcabitius, Montulmo, Lucas Gauricus, Simmonite, Zadkiel, Alan Leo, Pracht, Kloekler and Placidus himself."

These are mundane primary directions and as far as I can tell accord with the method recommended by Ptolemy and used by Placidus. It's the same method used by Ed Falis in his freeware program. I found Alan Leo's book on progressions helpful in understanding this method of primary mundane directing.

Tony

20
I contacted the makers of Janus and asked how they calculate primaries. Here is the response: "Janus calculates primary directions using the Placidus under the pole method. If you wish to trial Janus 3 you can download it from our website. http://www.astrology-house.com/janus/download_trial.cfm"

I think this is the same method used by Solar Fire. There are several rates (keys) in use for timing. Ptolemy used one degree of right ascension on the MC = one year of life. Morin preferred the natal daily solar rate = one year of life. I believe that Naibod and Cardan had their own preferred rates, all in the vicinity of one degree = one year, but over time the forecast can be off by a few years depending on the "key" chosen.

In response to Granny's inquiry about primary directions, the idea is quite simple. All the points and planets in the birth chart are carried along by the rotation of the earth after birth. Each degree of right ascension across the MC = one year of life. It takes about 4 minutes of clock time for one degree to pass the MC. Thus, the first 6 hours of the earth's rotation after birth correspond to roughly 90 years of life.

The "conjunctions" formed by primary direction are quite powerful predictive measures. Ptolemy suggested that when a directed natal planet or point rotated to form the same relation to the horizon and meridian as a natal planet, then the two were conjunct (in mundo rather than on the ecliptic).

Primary mundane directions are a bit difficult to calculate because the planets are rotating in 3-dimensions rather than being projected onto the ecliptic as in the standard horoscope chart.

I hope this makes sense.

Tony

21
astrojin wrote:
Next, the calculation of oblique ascension, OA
For OA I found the next steps:

1.calculate declination (D)

sin D = sin LONG * sin E

where LONG is ecliptic longitude of the Asc
E obliquity of the ecliptic

2.ascensional difference (AD)

sin AD = tan LAT * tan D

where LAT is latitude of the place

3.oblique ascension of Asc:

a. OA Asc = RA if the Asc is on Equator

b. OA Asc = RA - AD if Asc has north declination

c. OA Asc= RA + AD if Asc has south declination

for RA see astojin previous post