Somewhere deep in the bowels of The Wrong Sword, dozens and dozens of pages past the Amazon "free sample" point, is my own little salute to steampunk. Except it's pre-steam, and pre-punk. Paleotech! There's the phrase. You heard it here first.
Anyhoo, there's a scene where poor Henry is locked up in a tower with the medieval equivalent of a mad scientist with dozens of goonified inventions, and I'd just like to take this opportunity to say that I didn't make up any of them. Brother Wiglaf the mad monk may not be putting these inventions to the purposes for which they were intended, but they were definitely part of the literature, as it were...even if the literature is about six hundred years too early.
One of those suckers is the Faraday dynamo. A real one looks like this:
See, the original dynamo is a copper disc that's spun inside a magnetic field to generate an electric current. In TWS, it's more or less the reverse - a magnetic core that's spun inside a wheel of copper wire. There's no technical reason I did it like that, unless "sheer ignorance" counts as a technical reason. And I can pretty much guarantee that no matter how much you spin a real dynamo, it won't behave the way the lodestone dynamo behaves in TWS. But I can promise that what happens in the book is more fun.
And a tip o' the coif to Mikey Faraday, Frankie Bacon, and Markie Marcellus.