It seems we agree Capricorn and Aquarius are missing, and Aries and Taurus have two drawings each. So you’re trying to match 12 houses against only 10 signs?

I note that with the exceptions of Pisces (which has 29 nymphs – could the artist have miscounted?) and Leo (which I can’t confirm as the left side of the drawing is obscured but I believe has 30 nymphs), all the signs have 30 nymphs with Aries and Taurus having 15 on each drawing.

So it would seem to indicate a 360 day calendar with 30 days in each month / house … I was wondering if there was a connection to the Vedic calendar? It would be nice if we had Capricorn and Aquarius to confirm this, but c’est la vie.

There’s also the issue that while most drawings have 2 concentric circles of nymphs, some have 3.

CAPRICORN MISSING ???
AQUARIUS MISSING ???
PISCES 10 inner 19 outer (should this be 20?)
ARIES HALF ? 5 inner 10 outer
ARIES HALF ? 5 inner 10 outer
TAURUS HALF ? 5 inner 10 outer
TAURUS HALF ? 5 inner 10 outer
GEMINI 9 inner 16 outer 5 extra
CANCER 7 inner 11 outer 12 extra
LEO 12 inner 18 outer???
VIRGO 12 inner 18 outer
LIBRA 10 inner 20 outer
SCORPIO 10 inner 16 outer 4 extra
SAGITTARIUS 10 inner 16 outer 4 extra

I wonder if this has significance with certain religious holy days / pagan festivals ?

Anyway, some food for thought.

Marco Ponzi wrote: “While simple models of the astrological houses exist in which each house is made to correspond to a single zodiac sign, usually more complex systems are used.”

You are correct about those models. They aren’t just simple models, they are incorrect ones. Unfortunately, those models show a misunderstanding of the difference between a “house”, a “ruling sign”, and the constellations passing through a house. I have seen many sites where the writer assumes that a house is only associated with one zodiac sign—they neglect to consider that houses are always moving, as the Earth turns, and form a viewport of the constellations (both zodiacal and non-zodiacal) that is constantly changing.

[example]… Even if there are several different systems for computing houses, the signs that have no cusps must be opposite, and the signs that have two cusps must be opposite. It can’t be like the VMS that has consecutive signs with hypothetical double cusps and consecutive signs with hypothetical no cusps.

This is a good example and a good point. Even though signs can be in consecutive houses, one would not expect duplication or omission in two sets of consecutive signs. If Aries is duplicated, then one would expect another to be Libra rather than Taurus, and if Capricorn were omitted, one would expect the missing mate to be Cancer rather than Aquarius.

I’ve been trying to find medieval beliefs and customs that might explain the pattern of zodiac symbols together with the figures in the VMS wheels. The sequence is not a typical zodiac sequence or a typical calendar. In some ways, the medieval concepts of houses and horoscopes come closer to explaining the oddities than many other explanations, but I’ll agree with you that the layout of the symbols does not precisely fit this idea, either. Still, I hope it might inspire some different ways of looking at it, in the hopes that an explanation can be found.

Astrological diagrams represent the point of the ecliptic rising on the horizon on the left and the opposite, descending, point of the ecliptic on the right. The upper part of the diagram corresponds to the visible sky, the lower part to the invisible sky, and the horizontal to the horizon.
This applies to both these ancient square diagrams and to more modern circular diagrams like this:
https://commons.wikimedia.org/wiki/File:Natal_Chart_–_Adam.svg

While simple models of the astrological houses exist in which each house is made to correspond to a single zodiac sign, usually more complex systems are used. This is clearly the case with the two diagrams posted by JKP.
Often, the idea is to have as the cusp (beginning) of the first house the point that is rising on the horizon and as the cusp of the 10th house the point that is at the South (Medium Coeli).

If I understand correctly, one problem is that not all signs take the same time to rise above the horizon:
https://en.wikipedia.org/wiki/Ascendant#Long_and_short_ascension

“Because the Earth’s axis is tilted relative to the ecliptic, the twelve signs do not take the same amount of time to cross the eastern horizon … In the northern hemisphere, the signs of Aquarius, Pisces, Aries, Taurus and Gemini take much less time than the theoretical two hours to cross the eastern horizon”. Since these signs are “fast” it can happen that no house cusp falls in one of them when they are ascending.
“The signs of Cancer, Leo, Virgo, Libra, Scorpio and Sagittarius take much longer than two hours to do so” these slow signs can sometimes have two house cusps when ascending.

The effect is that (as you can see in the modern chart linked above) the Medium Coeli is not perpendicular to the ascendant. It will be tilted towards the ascendant (left) if slow signs are ascending, or towards the descendant (right) if fast signs are ascending. The effect of this tilt is that distance between house boundaries is not a regular, fixed 30 degrees. Since zodiac signs are by definition regular, fixed 30 degrees, you can have signs with two cusps or signs with no cusp.

The house computation for houses 10,11,12 (between the ascendant and Medium Coeli) is applied symmetrically to houses 4,5 and 6. So, what happens is that OPPOSITE signs can have two house cusps, in this case, another couple of OPPOSITE signs will have no house cusp.

In the Cambridge MS Peterhouse example, house cusps are:
gemini, gemini, cancer, leo, virgo, libra, sagittarius, sagittarius, capricornus, aquarius, pisces, aries
The fast ascending Taurus sign is ascending and has no cusp
Taurus/Scorpio are opposite and have no house cusps
Gemini/Sagittarius are opposite and have two house cusps each

In Henry IV’s horoscope:
gemini,cancer,cancer,leo,virgo, scorpio, sagittarius, capricorn, capricorn, aquarius, pisces, taurus
The fast ascending Aries sign is ascending and has no cusp
Aries / Libra are opposite and have no cusp
Cancer/Capricorn are opposite and have two house cusps each

Even if there are several different systems for computing houses, the signs that have no cusps must be opposite, and the signs that have two cusps must be opposite. It can’t be like the VMS that has consecutive signs with hypothetical double cusps and consecutive signs with hypothetical no cusps.

I don’t know if the astrological houses were intended to be completely stand-alone in the thematic sense. They start with “ego”, the self, and expand out into kinship, neighbors, and then to ancestors. The progression is not perfect, the 5th house, procreation and children, comes before marriage and partnerships (but that may have been common in pre-Christian days when pagan customs were more sexually liberal—if impregnated you got married). Short journeys and community come before long journeys. Business contacts come before authority/royalty/personal status. It might be easier to represent the relationships in a cloud diagram, but since they were constrained to a linear representation, it’s not an unreasonable way to encapsulate the journey through life, with only death/murder (8th house) seeming significantly out of place (in the middle rather than at the end).

The boundaries are not definite either, as least as far as the constellations are concerned. Medieval horoscopes sometimes repeat a zodiac sign in the following house because a constellation is composed of several stars and some of them might be in the next house while others remain in the previous.

I don’t know if the VMS wheels are intended to represent astrological houses, but if they do, then the oddities one sees when trying to interpret it as a zodiac cycle aren’t oddities at all—they are typical of a medieval horoscope—and the legions of nymphs surrounding the symbols may have an explanation, as well, if they are mnemonic examples of the influence of the house.

What I mean with the gradual progression is that in the VM, properties from one page spill over in the next. This is the clearest in the barrels. In the first four (fish, goats and light bull) all nymphs are barreled. Next, dark bull, there is even a transition with the inner circle barreled and the outer circle walking. This suggests a gradual progression that breaks month boundaries.

In the system you propose, I would expect one roundel to be “unaware” of the properties of its neighbours, because it’s an entity with its own unique properties. This is not the case in the VM, where there is a gradual (seasonal?) progression from rich, complex, fancy towards simple, bland and dreary.

Yes, you’re correct, a horoscope is a snapshot of one moment and only a few constellations are visible at any given time.

Depending on the latitude, one can usually only see about six or seven and yet there are typically more in medieval charts. I don’t think the charts are entirely based on what one can see (especially since we can’t see stars in the daytime), so I was wondering whether they begin with the one that is just about to come above the horizon (in modern astrology, I think they start with the ones that are behind the Earth).

If so, one would expect about eight or nine different symbols in each chart but even that isn’t enough, since both Henry VI’s chart and the VMS wheel-set include ten different symbols. I’m not an expert on astrology, so I can’t explain the discrepancy between those that are included and those that are omitted in relation to those that are on the relevant side of the Earth. I only know that the constellations appear in a variety of positions in the houses, depending on time and place, and that they are believed to influence how a specific house affects a person’s life.

As to there being a progression from one wheel to the next in the VMS. If each wheel represents one of the twelve houses, then the subject matter doesn’t have to be progressive. For example, in historic astrology, the eighth house represents death and murder, which one might expect at the end, but one finds it sandwiched between marriage and long journeys in both European and Arabic manuscripts. I think the theme of each house may come from the perceived characteristics of its ruling planet more than its proximity to the previous and following houses (I am not certain because the original logic goes back to the Babylonians, and I didn’t go into the ruling planets because I don’t see evidence of them in the VMS wheels, but it is one possibility).