Today's picture on the Google homepage is a picture based on the locomotive created by Richard Trevithick who was born 13 April 1771. It's a fantastic picture but has a minor fault. The gears wouldn't turn! If they'd checked the gear section of my website they would have realised that any ring of gears with an odd number of gears just won't turn! 

#1 Daughter says that I'm a 'geek' for pointing this out. A compliment I'm sure that she didn't intend 🙂