Simon ... you can revert to naked-eye during the totality but as soon as the tiny 'diamond' of the returning sun arrives it's back to the glass unless you have a thing for guide-dogs! 🙂
Considering how rare they are, I was astounded to find out how early they could be forecast ... the Babylonians in 500BC working on clay tablets could mostly forecast them ... and by 150BC the Greeks had true calculations to predict eclipses! .... smart buggers the lot of them! 🙂 .... goes to show that we're no smarter than our ancient forebears .... we've just had the time to learn more stuff and use more stuff.
K
Your referring to the Antikythera mechanism (
https://en.wikipedia.org/wiki/Antikythera_mechanism). An outstanding mechanism that was handmade. No CAD in those days.
