Redneck Rocketry

What is going on here? Looks like plenty of fun when you’re not in the line of fire. Not only are there explosions and barrels flying skyward, but, you know what they say: Everything that goes up must come down. How hard can a falling barrel hit you? Probably hard enough to flatten you!

A few commenters suggested this is a reaction of calcium carbide and water, which produces acetylene. That would makes these calcium carbide cannons. This is what happens when a village has no movie theater or bowling alley. (via Geeks Are Sexy)