I once had a clockwork toy – it was a black box with a switch, when you turned it on a trapdoor opened and a hand came out and returned the switch to the off position.
That’s it really, it was a mad, pointless, turning-itself-off machine.
(I have seen money-boxes that operate on the same principal, but they just don’t have the same esoteric, out-there, existentialist overtones, plus I hate saving.)
Anyone know if they are still made? A supplier in the UK?