[Combwork]

"Maxim invested £20,000 in building a huge, hundred-foot-wingspan, multi-winged machine, in England. It was powered by two lightweight 180-horsepower steam engines that he'd designed for it. Maxim began flight tests in 1894. On the third try the plane was powered up to forty miles per hour, left its track, flew two hundred feet, and crashed. After that, Maxim lost interest in flying. He went on to other inventions."

The point is that in those days, gentlemen with lots of money had hobbies; playthings. Things with no perceived practical value, to be played with for a while until something new caught their interest. There are different versions of the above but contemporary reports say the third run was to see how much lift the machine could generate above its own weight. To do this, as well as the two running rails a third rail was set above them. Lift against this rail could be measured but the machine generated so much lift that it tore the check rail from its mountings and crashed. Victorians were crazy, maybe insane by today's standards. No Health & Safety; "if you want to try it, try it. Your problem if it blows up in your face"

In the U.S. in (I think) the late 19th century, after a series of unfortunate incidents a law was passed making it compulsory for any steam launch to carry a qualified steam engineer. To get round this, someone 'invented' the Naptha engine. Same principle as a steam engine but it boiled Naptha so wasn't classed as a steam engine. Naptha can be distilled from petroleum or coal tar; highly flammable especially when hot. Some had a pipe going to a burner under the boiler.

I don't know how many were built, but I've read that they used to race the things.