To start at the beginning, read this first:
Planetary Time
To start us off from the wider universe, I used an astrolabe because theyโre intoxicatingly beautiful objects, but also because they are meant to offer Godโs perspective, looking down on the earth from beyond the stars.
I took advantage of the night-blue paper to place shiny gold stars on the rete, where it would normally only point to their locations. The rete is my own design but the stars are in the correct places, only I left out the labels. The ecliptic on the other hand bears as usual the names of the Zodiac signs. And the astrolabe, though not exactly functional, is still designed for the latitude of Oxford.
Astrolabes were incredibly useful and versatile tools, with applications ranging from calculating distances to telling the time (the astronomer al-Sลซfi listed 1,000 uses for them), and astronomy treatises often included instructions for their making.

Journey through the Spheres
In the original Greek, the word "planet" means "wanderer". It applied to the celestial bodies that could be seen to move independently, in contrast with the "fixed stars", the backdrop of constellations that only moved as a whole, as if they were points of light on the surface of a vast rotating vault. For this reason the Sun and Moon were counted among the original, "classical planets": our modern definition of planets as opposed to stars had not yet been created and has no relevance there. The other five โwanderersโ were those observable with the naked eye, Saturn being the furthest. These seven planets were observed at least as early as Babylonian astronomers, and as early as 2,300 BC there is evidence of a seven-day week being observed. This whole volume examines how our week, which starts with Sun-Day and ends with Saturn-Day, came about โ but the long way around.
The cosmic perspective of the astrolabe brings us to the map of the visible universe from the geocentric point of view of the Middle Ages: the vault of the Fixed Stars circumscribes it, while each of the classical planets occupies a Sphere, beginning with Saturn and descending from sphere to sphere to Luna, and finally the world.
This is the Chaldean order (also Ptolemaic system), which arranges the planets from slowest- to fastest-moving (relative to us); this corresponds roughly to furthest planet to nearest. This map, which is actually the simple version of an elaborate system that often overflowed into metaphysics, was as common in medieval times as the planisphere is to us today. The first of the examples below, which shows stars in the outermost sphere, is quite close to the layout I used. But the fixed stars I placed there are not random, as we will see.






Saturn
The names of this and the other planets are in a style of Kufi typical of astrolabes (including the stretching all around the circle), and they're each preceded by a small symbol weโve seen before.
While different cultures are at variance regarding some of the planets, Saturn is universally associated with the colour black. Two of the constellations from the previous sphere are now highlighted, and identified by their tiny zodiac symbols: Capricorn and Aquarius both of which are ruled by Saturn.1
Here I should mention that all of the pages in this volume were hand-dyed for this purpose, using historical dyes. The black of Saturn required a special process: first soaking the paper in gallnut decoction, which barely dyes it at all. Then plunging it in ferrous sulphate, for this spectacular result.
Jupiter
In the Islamic system, the colour of Jupiter is sandalwood, which is brown: this adjective doesn't exist in Arabic and today the equivalent we use is "coffee-coloured". The paper was dyed with walnut. Jupiter rules over Pisces and Sagittarius.2
Mars
Mars is of course red, and rules over Scorpio and Aries.3 The paper is dyed with cochineal, to replace the more period-accurate, now unobtainable kermes.4
Sol
The Sun is strongly associated with gold, but in terms of chroma it is a strong yellow, weld in this case. The Sun only rules over one sign, which is Leo.5
Venus
Venus is associated with green in this system, which required a first dipe in weld, then overdyeing with a derivative of indigo called Saxon blue. Venus rules over Taurus and Libra.6
Mercury
Mercury's blue was also achieved with Saxon blue (which doesn't get any darker than this). Mercury rules over Gemini and Virgo.7
Luna
Finally, the Moon is white (or silver) and rules Cancer.8 And here, within this final sphere, is our world made up of the four elements we have glimpsed before. In many maps, these components of the Sublunar world are arranged in a further set of rings, from most subtle to most dense: Ignis (Fire), Aer (Air), Aqua (Water) and at last, Terra (Earth). Hereโs a diagram that illustrates this hierarchy while simultaneously showing the elements as the four sides of one square.
Planetary Hours and Days of the Week
This lengthy introduction brings us to the heart of planetary time. We all know that the days of the week are based on the planets, but whatโs less understood is that this is a result of the planetary hours, which is also the reason why the weekdays are not in the same order as the spheres.
In Antiquity, the planets were given rulership over each hour of the day. The first hour of the first day (counted from sunrise) was ruled by Saturn, the second hour by Jupiter, and so on according to the Chaldean order. That first day which started with Saturn was also as a whole dominated by Saturn: it is our Saturday. But because you can't divide 24 hours by 7 planets, the planet for the first hour of the next day (or 25th hour) would be three planets down from Saturn: it is the Sun, for Sunday. You can guess what planet the next day begins with, and so on. The entire sequence of the 168 hours of the week is laid out in this table:

This, by the way, is the origin of the planetary symbols I've been using in various places, instead of the generic modern ones. I believe they may have been specifically created by the author of this almanac, because he included a key to reading them:
How to translate this unfamiliar system into a volvelle was quite tricky, and made trickier by the fact I needed the volvelle to then turn and reveal all the planets in their โnormalโ circle. This is what I came up with, relying more than ever on the reader's observation skills.
When you land on this page, it shows the Sun, instantly recognisable in any iconography.
The other window shows a symbol that is half day, half night, with two sets of numbers 1 to 12 in matching blue: the hours of day, and hours of night. Inside the window are the planetary symbols, and you may notice that in this case the first hour corresponds to the Sun which is dominating the page (it's a gold circle, so it should be obvious even if you've never seen the symbols before).
All around the volvelle are the letters A to G, which in medieval calendars were the norm to indicate the days of the week. Sunday was always written in gold, though the letter changed from year to year9 (this is another story). Here you would notice that the Sun is under a golden A...
... and hopefully this would suggest turning the volvelle to the position B.
This is another very obvious personification, the Moon, with a small silver crescent showing for the first hour. So B is clearly Monday.
The emerging pattern should be clear enough for you to expect that turning to C, you should see Mars for Tuesday.10
Then even if the iconography is alien โ which it probably is, as like my Zodiac signs it originates in the Middle East โ you would be able to recognise the rest of the planets based on your knowledge of the sequence of days: Mercury for Wednesday (D), Jupiter for Thursday (E), Venus for Friday (F) and Saturn for Saturday (G).
Until finally we see the planets in full, in their traditional sequence.
The faces already turned up on their own in the pages on the Decans, and you could say this is the payoff for the planetary clues that were sprinkled earlier, but one can just as well start with this volume, and go into the Solar Time with this foreknowledge for a slightly different experience.
To end this volume with a note on materials: the filigree work on this volvelle, and fine lines and details throughout the three volumes, were done in inks prepared from the gardens of Merton College. With the head gardener's permission I gathered and tested four flowers (I wasn't resident on site until October, so had to come over one day in May and collect what was available then): iris, camassia, wallflower and a type of marigold.
The iris gave a gorgeous blue and the camassia, which were entirely new to me, a lovely teal-to-green. The wallflowers, always an unpredictable flower, dried red but painted green! The marigolds were interesting golden hue, but I worried this would soon turn brown, so in the end it is iris and camassia that are woven through the pages. Other pigments are principally the mineral and inorganic ones that would have been used in the Middle Ages: cinnabar for red, orpiment for yellow, lapis lazuli for blue...
This wraps up my Circles of Time, though I still get to work on reproductions and probably an even more in-depth book version of this series of articles. But first, I have a move to completeโฆ See you on the other side!
For a more detailed look at Saturnโs iconography, see my earlier post:
Cochineal is now widely grown, but kermes species are wild, and have suffered much from over-harvesting and habitat loss.
This is another story, which you can read about here, under the โDominical Letterโ heading:
This actually doesn't work very well in English, where some of the days ended up named after Germanic deities! It helps to think in a Romance language for this one.
What an achievement!
This is amazing work, and so beautiful.