Eclipses can only occur when the Sun is in conjunction with the nodes of the lunar orbit (intersections of the Sun's orbit with the Moon's) and during a lunar or a solar eclipse.
With this instrument, you can find both the dates of node conjunctions and dates of 🌑 and 🌕. An eclipse happens when they occur a few days appart.
The approximate aspect of the eclipses is visible through the 2 round windows on the uppermost disc.
I made a modern version of the Rotula for the 2026-2060 period. A feeling of magic at work when you find that the predicted dates match the ones found on the web, to the nearest day...
My version is made with #TeXLaTeX (TikZ) with some #Python .
I started making paper astronomical models during Covid: I didn't know such nice paper models existed...
As usual, everything you need is available on my website for download. Print & cut out the wheels and follow the instructions on the 12-page PDF. I wrote a user guide in french, and also one in english.
https://www.astrolabe-science.fr/maquette-astronomical-rotula-de-ferguson/
