There is a wheel that was turned by donkeys, then a later one turned by horses. I only got a snap of the horse one.

But that reminds me of my Gneral Studies 'A' level exam. I think it was an excellent idea because it forced we science bods to learn something about art and architecture and the arts people to learn some science,

Anyway, one question was a woodcut of a horse turned wheel connected to some cog mechanism and we had to work out whether a rope at the end would be raised or lowered. All round the room were people moving their hands in small circles as they tried to work it out.

Another section was a language translation. Because of the way it was marked your lowest score was not included, so what the hell, I picked a section in Russian. I didn't even know the alphabet!

But my all time favourite exam question was in my 'O' level chemistry practical question which was insane, but as I think I have said it before I won't repeat it unless asked.