This is a single microscope from a page of microscopes in the 1797 edition of the Encyclopedia Britannica, which I found on archive.org.
This particular one is a compound microscope. It’s mostly brass (or, as the encyclopedia puts it, “a large external brafs body, A, B, C, D, fupported upon three fcrolls”), but has a convex mirror down below and some lenses that can be slid up and down to focus.