Historical notes are now appearing beneath the pages (as well as on the historical notes tab.) Just click to expand the text.Historical Note
Our boy’s muttering to himself about Jupiter, I see. Medieval occult magic relies on certain astrological aspects (which change daily) to work properly, and I feel like Jupiter’s probably the planet you’ll want in a good position if you want some luck in finding someone (Jupiter ruling luck, not really errant princes.) His “tables” are just that: tables about what planet is where and at what degree every day. These tables would’ve had to be hand calculated by some sort of magic (ha—but really, math back then was considered a sort of magic) that is beyond me. Tools like astrolabes could be used as well for some planets/luminaries and more minor astrological placements, but you’d need a equatorium for the bigger, more complex things.
If you’re interested in seeing some actual medieval astrological tables, please do go have a look at Equatorie of the Planetis from 1393.
My medieval hand is not quite up to par yet, but I’m trying. You can see as well that Merin’s using Arabic numbers here in his tables, which I think he would consider to be magical numbers. England largely still used roman numerals for most things.
a note on a note? why not—if you wanted to know what planet would rule our errant prince, that’s Mars. Arthur’s super Mars heavy by way of Aries rising and having a stellium in Scorpio (Pluto hadn’t yet definitively been discovered, so Scorpio was still ruled by Mars.) He’s also got a lot of Lunar dominance. Why yes, I do have Arthur’s natal chart. You can assume that Merlin’s also drawn it up in canon, which is basically an act of treason.