In addition to being in charge of the Paris Mint, Philippe Danfrie was also an inventor and engineer who built astrolabes and clocks and he cut his own type for his publications.
His invention seen here is a graphometer, essentially a simple theodolite with a graduated semi-circle and sight arms which could be affixed to a telescope if needed, but was mostly used for measuring horizontal and vertical angles by triangulation in surveying up until the mid-19th century.
[It was actually the beautiful lettering in the text that drew my attention and I am no typophile].
- Declaration de l'usage du Graphometre  is online at the University of Virginia (thumbnail page).
- The Geometry of War at the Museum of the History of Science, Oxford University.
- Epact - Scientific Instruments of Medieval and Renaissance Europe.