As you can see, there are several variations of one image.
Researching online is complicated: on the one hand, everything is all right there! I can sit in my pajamas and access a universe of knowledge. But....being so effortless, it's easy to get sloppy, to delight in the wealth of images without checking them too deeply. Which is how, when I went back to investigate a little further (after I had started sewing) I found that my image of the House of Wisdom was...the one in Istanbul, not Baghdad. Oops.
I found this error while trying to name all of the devices being used in the picture. I did get most of them, but there's a long oval with something red on it (under the astrolabe) which defied identification. I sent it to a professor of Medieval History, who suggested it was their lunch.........(really? just say "I don't know")