Handley Page built a steam powered aircraft as well, but it never flew. The name escapes me, but it was akin to their Pullman passenger aircraft. It featured a single steam engine mounted inside the fuselage, driving two four bladed props via belts, so from a distance, it looked like a twin. It failed to fly however.
Another thing to note is that another early aviator, Clement Ader of France, flew his steam powered Eole in 1890. The engine itself was a marvel of engineering, being extremely light weight and driving a tractor propeller. It is generally accepted that he made some short flights from level terrain, although the problems of control were never fully solved. His later aircraft, the Avion III, was never successfully flown, but has been preserved in Paris.
Again, thanks for the great article!