The article quotes the Didot system, specifically, which focused on printing travel maps and is known not only in the French speaking world for its timely accuracy [1] as it was also using that very same map system.
Maybe read the article next time?
[1] https://en.wikipedia.org/wiki/Didot_family
[2] https://fr.wikipedia.org/wiki/Histoire_g%C3%A9n%C3%A9rale_de...
Neither the wikipedia page for the Didot family, nor for Histoire générale des voyages shows the Angzarr symbol, I've carefully checked on all the scans on these pages. In fact, any occurrence of the symbol would pre-date the current earliest known example (1963) by 200 years, and that would be a great find. If you have an actual reference, please let us know!
"Haussystem Didot", the title of the catalog, refers to a letter setting by the printing agency Didot, which is the one I linked on wikipedia.
The Gallica scans are linked in the wikipedia article. Each of those chapters has hundreds of pages.
I highly doubt that you eye scanned thousands of pages in French handwritten and mixed typesetted ... within less than a day. You definitely must be lying, they take months to read.
[1] https://ionathan.ch/assets/images/angzarr/Berthold%201900.jp...
