Pop Can Cannons

First, a Warning[1]

I've seen a beer can, cannon made, useing 3 or so beer/pop cans, with the ends cut out of all of them but the last one, stacked end to end, and duck taped together, a tenis ball fits in one end, then useing a propane torch (like you use for soldering copper watter pipes) you fill the cans with gas, through a small hole that you make tward the bottom of the last can, now this works best with one of the torches that has a push butten ignitor, sence then all you have to do, is hit the butten, and it will shot the ball. now make sure that you have enough tape around the cans, so you don't have the thing fly apart, for that would be a BAD thing to have happen.

How I have seen one of these used, is you set it on the ground, pointing strait up, put your tennis ball in it, fill it with fuel, and ignite it! there should be a nice little pop, or poof, and the ball should fly up in the air! Things you should not do, such things as is set the ball on fire, point it at people, or try to push the limits of it, for it might blow up in your face, and you don't want that to happen, trust me.

[1] seeing as how you are making an explosion, useing a combusibile gas, it is a good idea to at least wear protecitive eye wearm, and gloves, incase something goes wrong, and also start small (just use a little accetaline at first), so you don't blow your self up!