I’ve not seen one of these in ages, a fully working minature steam engine (and I’ve never seen a model engine with so much shiny brass).
The classic Locomobile is works like a real steam engine but is 1/8 the size. You fill the boiler with water, light a dry spirit tablet and when the boiler is hot enough the steam powers the engine (and the all important whistle).
This is one of those toys that as well as being fun and educational is also a pretty good investment IMO (though bear in mind I have a shed full of 2000 AD comics that I thought would be worth something one day (Sylvestor Stallone (Judge Dredd) has a lot to answer for)). You can get the Classic Working Steam Engine Locomobile for $549.95 from Hammacher.