To all who live south of Watford, London is doubtless the hub of the solar system, as Boston State House was to Oliver Wendell Holmes. Asked for greater precision, they might opt for 10 Downing Street, Charing Cross, or Threadneedle Street according to taste. Most people I have asked “where is the centre of Britain?” plump for Meriden, but that answer would not commend itself to the inhabitants of Scourie. And if you should chance to be in Allendale Town on New Year’s Eve (assuming you can find the way to it), you will be in no doubt that this is where it’s at, and you have reached the roistering heart of Britain. But to give a more reasoned and accurate answer is an investigation well within the scope of a school class equipped with an O.S. map and a micro- or mini-computer.