[gothink]

I had an amazing science teacher in high school who brought a potato cannon he had built into to class to show us. Except he called it a "sock cannon" and had loaded it with a large tube sock that he had rolled up. He explained how it worked, how he built it from a few basic plumbing parts anyone could get at the hardware store, how the fuel was just hairspray and how we definitely shouldn't build one ourselves.

Naturally, I went home and decided to construct a much bigger version of the one he showed us. After convincing my parents to drive me to the hardware store, I picked out what I needed -- including 7 feet of PVC. The clerk immediately figured out what I was building and that was the first time I heard the term potato cannon. They seemed concerned that my mom was on board with the whole thing, but I stuck to my guns and said it was a science project and was for shooting socks. I had figured I could wrap the sock around a smaller projectile, but that clerk made me realize I didn't even need the sock.

My friend and I put it all together pretty quickly the next day and set it up in my backyard for testing. I think we probably started with socks, but I honestly can't recall. What I do remember is taking a hacky-sack I had lying around that fit perfectly into the barrel to try and fire it at our back fence. We were using a piezo igniter from a lighter I had disassembled, and it took some trial and error to get the fuel to air mixture just right. It took both of us to operate: one person aimed the barrel, the other operated the trigger. This time, I was aiming and he was lighting. But it just wasn't lighting... so I turned around to try and help and BOOM the cannon went off like, well, a cannon. Except I wasn't pointing at the fence anymore, but well above it. The hacky-sack tore through the branches of several trees before exploding on the metal siding of the house on the opposite side of our block. The sound could probably be heard for blocks.

We both just looked at each other with a mixture of delight and panic before immediately running back into my house. We saw someone come out of the house we hit looking utterly confused, trying to figure out what just happened. We started laughing uncontrollably, realizing how close we were to causing a lot of damage, or possibly injuring someone.

Luckily, nothing every came of that incident, and we made sure later tests were done in a nearby park. We never did attempt to put an actual potato in the thing. Perhaps 7 feet was a little overkill...

PS - Dr. Vince, if you're out there, thank you for being one of the best teachers I've ever had. I'll never forget that class, or that "sock cannon"!