Lateral Thinking #08- A Tight Spot -

This puzzle is often given to students to teach them about creative thinking (i.e. thinking outside the box). Imagine yourself in a room without windows or doors (there is still light in the room so you are able to see). In the center of the room is a twelve inch tube solidly embedded six inches deep in a cement floor. At the bottom of the tube is a standard ping pong ball with a diameter that is one millimeter smaller than the diameter of the tube. You have the following items at your disposal:

* a twelve inch piece of string
* a match
* a magnifying glass
* a six inch ruler
* a paper clip

Aside from the items listed, there is nothing else in the room. Can you find a way to safely retrieve the ping pong ball without damaging it? The tube cannot be broken nor can it be removed from the cement floor.

PS: If you're not sure your solution will work, you haven't found the answer.