I went to the rebuilt Museum of Arts et Metiers yesterday, and it was a great better than it was when I last went through it twenty years ago - good displays, well laid out and quite a bit of explanatory material - less in English than in French, but the French did invent chauvenism.
It still fails to do justice to Vaucasson's sliding lathe from 1751, which can claim to the ancestor of all modern lathes, mainly by virtue of its wonderful lead screw - the Scientific American article on the subject (from the early 1980's - IIRR) was pretty explicit on that claim, but no French museum keeper is going to pay any attention to that.
And there is a Bruget(?) biplane which - IIRR - held the world altitude record for a while, for which I could find any description at all. It was just hanging there in the chapel, next to Bleriot's cross-channel monplane from 1909, which was well-documented (as if it needed documentation).
The museum has also got Joseph Cuget's steam-driven "Fardier" from 1770
- for pulling artillery around - with a video clip recording the consequences of designing a self-powered vehicle without a braking system ... and a reassembly of Lavoisier's orignal laboratory. Great stuff, well-displayed.