A sextant can be used to obtain the relative horizontal angle between two landmarks, but it is much easier to use an azimuth ring. A sextant is designed to be used vertically. Holding and using one horizontally is difficult and time-consuming in comparison and is probably a less than a 1% use case, used only during the training of apprentices as a theoretical exercise (source: professional mariner for many years and daily user of a sextant back in the day). A comparison would be using a screwdriver to drive in a nail; you could do it given enough time, but a hammer is much easier.
I believe the explanation is much simpler: the glyph simply represents a variety of angles measured from north (the common meaning of azimuth) avoiding the use of any lettering (like “N”) or the use of a compass-like symbol which would be difficult to represent at such small scale.
Also (pedant warning for another poster) Polaris is not the brightest star, it’s around the 40th and has no practical use for navigation other than “north is roughly that way”.
"Haussystem Didot" in the article's referenced typesetting catalog refers to the typesetting of the Didot family's printing agency. And they used that symbol 1700 and onwards in their map navigation descriptions in these books:
https://fr.wikipedia.org/wiki/Histoire_g%C3%A9n%C3%A9rale_de...
I am gonna repeat myself, but search for the Gallica links in each of those books to find the scans. There you can see earlier usage and evidence that as I pointed out in other - downvoted comments - that this was commonly used for sextant navigation instructions.
This reminds me of another Unicode block with ancient origins: the 64 I Ching hexagrams (U+4DC0–U+4DFF). Unlike ⍼, their meaning has been documented for 4,000 years — yet they carry their own encoding surprise. Unicode actually follows the traditional King Wen sequence: U+4DC0 is ䷀ (Heaven, #1) and U+4DC1 is ䷁ (Earth, #2). Interestingly, this is different from the binary Fu Xi arrangement formalized by Shao Yong (邵雍, 1011–1077), where ䷁ (000000) comes first and ䷀ (111111) last — the very diagram that captivated Leibniz in 1703 as a mirror of binary arithmetic [1][2]. Two valid orderings, encoding two different philosophies of where to begin: with pure creation, or with pure potential.
By the way, DNA also produces exactly 64 codons (4³ = (2²)³ = 2⁶) — the same number. Some have even noted functional echoes: DNA has start and stop codons that initiate and terminate translation; the hexagrams have corresponding structural counterparts [3]. Probably coincidence. Probably.
[1] https://leibniz-bouvet.swarthmore.edu/letters/letter-j-18-ma... [2] https://leibniz-translations.com/binary [3] https://www.goodreads.com/book/show/78369.The_I_Ching_and_th...
In the case of the i-ching it's literally six bits of binary (expressed in yarrow stalks).
In genetic codons there's four symbols instead of two, and three places instead of six, so the effect is the same. (Does base 4 have a name?)
And yes, base 4 does have distinct names in this system. Two digits give you the Four Symbols: Old Yang , Young Yang , Young Yin , and Old Yin . Add a third digit and you get the Eight Trigrams ( ), a core symbol of Daoism. Double that to six digits and you arrive at the 64 hexagrams — the I Ching, the Book of Changes, which many Chinese have believed could be used to divine the future.
Actually, Taiji, Yin-Yang, and Daoism are deeply related. Dividing Taiji gives you Yin and Yang — humanity recognizing something out of nothing, order emerging from chaos, duality arising from the void. You learn what "good" is, then you know "not good"; we coined "LLM," and we also invented "not LLM." They always come in pairs — that's the fundamental rule. We're essentially building our culture and recognition by inventing new names, mappings, and combinations to carve distinctions from some "embedding space." And we humans, including LLMs, learn from those names.
So the progression is: Void → Taiji → 2 (Yin / Yang ) → 4 (Four Symbols ) → 8 (Trigrams) → 64 (Hexagrams). Each step is just another bit of binary, but the ancients gave every level its own named structure.
At its core, it's philosophical thinking — and personally, I believe there's great wisdom in it. For example, we should never be trapped on one side and should always think beyond it. I came to know about this about a year ago and still find it fascinating. (Shameless plug: I even built a site about all this — https://ichingdao.love)
Quaternary
Maybe this is the opportunity to invent and suggest a symbol for Altitude?
Consider the Moon as viewed from NYC at time of comment [0], it is hiding below the horizon. If you were to look at my website and then at the sky you might become upset that I am reporting the shape of the moon, but obviously it can't be seen. Hence why the website reports the angle below the horizon roughly half the time it isn't visible.
Adding Azimuth and Elevation when the Moon is above the horizon would be for completionism only and not the real enterprise use-cases served by ANSI compliant renderings of the Moon.
[0] https://aleyan.com/projects/ascii-side-of-the-moon/?lat=40.7...
Every once in a while you run into something like this and realize the standard is not just for text encoding but also a kind of archive of specialized notation from different fields.
It makes you wonder how many other symbols are sitting in the table that are still mostly unknown outside the niche communities that originally needed them.
Unicode's entire point being to make "normal software" handle those symbols ;)
For years Ł support on Python on windows for example broke sometimes when imported from poor quality Excel files haha
Ah, of course :)