Complex sentence: Martier, however, was killed while testing this invention, and Davy inherited both the plane and a uniform, which had apparently been in Martier's family since the French Revolution.
Split into simpler sentences: Martier, however, was killed while testing this invention, and it was inherited by Davy. Davy, in the process, acquired his outfit, which had, apparently, been in Martier's family since the French Revolution.