[calmbonsai]

That's so cool. Like mathematical primitive archeology. The history of these sorts of analog computing devices that physically encode non-linear mathematical relations is fascinating.

With much tutoring, I learned to use a sextant and doing that gives one some sense of the "sorcery" and power achievable with blue-water navigation.

Boyer and Merzbach cover some of the development of these tools in their "History of Mathematics". Highly recommended.