A pair of André Bechler Swiss "Simplex" Gear and Pinion Engines - unusual in that they were discovered unused decades after they were manufactured. One was then set up on a stand ready to use, the other preserved in as-found condition.
The two machines appear to have been supplied originally to the Cosa Corporation of New York, a Company engaged in horological and mechanical instrument work and who once, it is believed, made a lathe for watchmakers - an example of which has yet to be found.