Did you know this? The mother of all steam engines was a ball that could rotate by steam-powered recoil and was already invented in the 1st century AD by Heron of Alexandria.
(s Wikipedia:. "Aeolipile"). It is also the same principle how this floating gyro rotates.
And so does its water pulse drive, how it also is in pop pop boat, the famous toy.
A tealight brings the water in the copper pipe-spiral to boil, the steam pushes it out to the ends and creates a recoil, condenses again and brings more water into the pipe. This process is repeated several times per second, as long as the heat is sufficient.
This is very nice to look at and also makes you imagine, how it would be to transform the steam rotary into a floating lantern or a light buoy, by attaching a small paper cylinder.

Equipment:
Cork disc Ø 80 x 10 mm with pre-drilled holes
Copper pipe spiral with annealed legs
Bending tool for tube ends
(Candle not included).
Construction time: only about 15 minutes
Packaging: 148 x 105 x 10 mm