Fully digitized and online at the British Library.
This 2-page spread is annotated with right-ways Italian, so you don't need a mirror to read it. I still can't. But the context of these sketches, judging from those on adjacent pages, is siege warfare and heavy artillery. Could the object on the left be a propellant-driven missile? Were these kinds of pyrotechnical objects known to him, via imports from China?