Steam tricycle

A man driving a Serpollet steam tricycle.

Léon Serpollet (born on October 4, 1858 and died on February 1, 1907) was a French inventor who built a steam tricycle in 1887. He would later perfect the flash boiler, which made steam a much more practical source of power for an car. He built and sold cars under the name Serpollet and Gardner-Serpollet (the latter of which was a partnership with a wealthy American named Frank Gardner) until his death in 1907.

After Emmett Brown's first experiment with the Jules Verne Train failed, Clara Clayton noticed a man driving a Serpollet steam tricycle. Upon seeing the vehicle, Doc remembered the early experiments with steam-powered automobiles, and decided to use Serpollet's innovations in his own steam engine design.