"Choo-choo!" If you are a parent of a pre-school kid, chances are you've whiled away many hours of your life playing trains. Thomas trains, to be exact. But have you ever held that little wooden train and wondered where he came from? How much do you know about Sir Topham Hatt's "most useful engine"? Here's a brief design history of how Thomas grew from a father's gift into a toy beloved the world over.