alt Hacker News> Great detective work
"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.
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Fascinating links, but I could not find an example of the glyph in question? My point was that a sextant is not (and cannot be) used to measure azimuth. It primarily measures the angle between a celestial body and the horizon (i.e. altitude). It can also (theoretically, very rarely) be used to measure the horizontal angle between two or more landmarks, but that is not azimuth in the accepted sense of the word. I am happy to be corrected though; my experience of sextants may be too narrow or modern for this context.
The image referencing "Haussystem Didot" is an example of a catalog not containing the Angzarr symbol in question.
I did not find any evidence for earlier examples in any of the very few scans I looked at, nor does a search through the Google Books scans give any indication for words that seem related to the concept.
This would be such a fantastic find! Could you point out a specific example?