Here is one of my notebooks sitting on a modern astrolabe treatise. The top section of the page has notes and sketches of details from the retes of two astrolabes at the Museum of Islamic Art. The bottom half is all marginalia, both the sketches and the writing.
…and this goes to show that I’ve been reviving my astrolabe work recently. I will be posting more about it on the blog, so keep an eye out!