Information any model railroader may already know... but, James Mays always seems to present these things in an entertaining, and informative way. (I blame this man for getting me back into Model Railroading, what with his "Flying Scotsman with Authentic Chuffing Sound")

BTW... the "Authentic Cuffing Sound" was a small piece of plastic pressed against a small plastic gear on his old Hornby "Flying Scotsman".