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We are looking at the last two columns of the table, and whether Mercury should change from being defined as slow to fast once it moves a full degree in one day. My argument is that if Mercury moves 1?14 or 1?23 (or something like that) per day on average, it shouldn't be defined as fast in motion until it moves more per day than its average measure.

I am sure that will have made you more confused :?

Run the chart for the same time and place for 13th February 2009 and let us know what it says for Mercury in the last two columns of the table. Mercury will have a daily motion of about 1? at that time, and so it is not moving particularly fast, but Janus defines it as fast in motion for that chart - does Astrowin?

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Hi, sorry if I am repeating someone, writing in a hush...

John Frawley, in Horary Textbook, despite defining the average velocity of mercury and venus as 1 degree by day, say that they are slow or quick when

mercury fast when above 1d30 slow when below 1d

venus fast when above 1d10 slow when below 0d50

I am not sure if this is what you are looking for...
Meu blog de astrologia (em portugues) http://yuzuru.wordpress.com
My blog of astrology (in english) http://episthemologie.wordpress.com

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Thanks Yuzuru - that is interesting.

It touches on the same issue, but the logic doesn't seem to be consistent (the point is, that the average velocity is not 1?); and there is no explanation for his figures.

The usual approach is to define a planet as swift in motion as soon as it exceeds its average motion. Although it is safe to say that Mercury is slow when moving less than a degree a day, and fast when moving 1.30 degrees a day, there is a half a degree of fudge inbetween :)

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I have been looking at www.skyscript.co.uk/mercuryorbit.html

Scroll down to Fig.2 . If mercury is fastest at superior conjunction which is midway between GEW and GEE then could we put a point equidistant between Sconj and either of GEW and GEE and find a way of plotting that as a longitude could we declare the speed there as average.Can someone good at sums see if this works?

Matthew

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Deb wrote:We are looking at the last two columns of the table, and whether Mercury should change from being defined as slow to fast once it moves a full degree in one day. My argument is that if Mercury moves 1?14 or 1?23 (or something like that) per day on average, it shouldn't be defined as fast in motion until it moves more per day than its average measure.

I am sure that will have made you more confused :?
If the software mentions the rate of daily movement- then you can use any value you have in mind to decide the fastness or slowness and, ignore the speed mentioned in Astrowin.

I am not a programmer but, the source code for that programme is available and maybe some one can tinker with it to put an option that decides how fast or slow is printed in output.

PD

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Deb wrote:Yes, but at the moment PD, nobody seems to be very sure of what the correct value should be (that's the gist of this thread).
Ah!
I thought your grouse was with the software :bl

If a planet has extreme speeds then it's mean rate will never seem realistic. It may be best to pick the mean from a velocity zone in which it works for a majority of time. This question should be addressed to the statisticians.

PD

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Hi Astrojin

I did see that post earlier, but it doesn?t really help in this matter I?m afraid, despite your hard work. The problem is that you have used the mean progress of Mercury through the zodiac over 100 years. Since Mercury and Venus revolve around the Sun as they move along the ecliptic, a mean measure of their progress through the zodiac, even over the course of a year, is forced to tie them to the progress of the Sun. That is the reason why we get the widely reported average of 0.59 for Mercury and Venus as well as the Sun.

This overlooks the fact that as the Sun is steadily trotting along the ecliptic in a perpetually direct motion, Mercury (like an energetic child running circles around its strolling parent), moves forwards, backwards, and forwards again, doing proverbial cartwheels around the Sun in order to stay centered upon the same area of the ecliptic. So, without doubt, Mercury and Venus, have a greater rate of daily movement than the Sun. If we want to know whether Mercury will, say, make an application and complete an aspect with another planet in 6 degrees, in a motion that is faster or slower than its usual rate of motion, we have to consider its motion against its usual *daily* motion, and not its average rate of progress through the zodiac per year which ignores the period spent making retrograde loops.

Do you understand my point?

I don?t think the calculation need be complex ? it is just going to be a laborious procedure, and I?ll do it myself when I can find the time for it. It requires the actual daily movement of Mercury and Venus to be added up over a period of time and then divided by the number of days considered to get a figure which reflects the average distance that Mercury travels (forwards *or backwards*) each day.

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Hold the calculations. I have found a few good, independent sources which back up the information given on the glossary page, (with just enough difference in the minor details to show that they are not based on each other).

Robert P. Blaschke talks about the need to consider the speed of planets in the effects of secondary directions and gives the following table of their usual daily motion:
http://www.earthwalkastrology.com/image ... ssions.pdf

Sun - 0 59' 08"
Retrograde periods: none

Moon - 13 10' 35"
Retrograde periods: none

Mercury - 1 23'
Retrograde periods: 20-24 days three times a year

Venus - 1 12"
Retrograde periods: 40-43 days every 11/2 years

Mars - 0 31' 27"
Retrograde periods: 58-81 days every 2 years

Jupiter - 0 04' 59"
Retrograde periods: 4 months yearly

Saturn - 0 02' 01"
Retrograde periods: 41/2 months yearly

Uranus - 0 00' 42"
Retrograde periods: 155 days yearly

Neptune - 0 00' 24"
Retrograde periods: 158 days yearly

Pluto 0 00' 15"
Retrograde periods: 160 days yearly

Similar information is given in another article at http://members.fortunecity.com/rosanist ... ceng12.htm
And this issue was also covered in the HP, special edition, 1996, p.15.

So I think that settles it. Note that most software programs and many books are giving out the wrong information regarding the average daily motion of Mercury and Venus, and defining them as fast in motion, when they are still moving relatively slowly.