"A compass is an instrument for indicating horizontal direction relative to the earth! It has two important parts to it:
  • a face with directions imprinted on it, usually about a circle.
  • a magnetic needle which, when the compass is held level, floats freely on a central pivot. The needle is centered over the circle and rotates until one end (the black end in this case) points to magnetic north and the other end (the red) points to magnetic south!

    Magnetic north and south are usually close to ordinary north and south, so we won't worry about the differences here!"

"Well, that's a relief! But what are the numbers and letters?! I'm used to words, like 'north' and 'south'!!"
"Good questions, Lou! Start by going to 'Direction' and follow the link to 'Azimuths'!!"

David Leveson