Okay kiddo, have you ever played with a toy cannon that shoots out tiny pieces of paper or play dough? A double-barreled cannon is kind of like that, but much bigger and much more powerful.
Imagine a big, tall cannon with two barrels instead of one, side by side. It's like having two toy cannons welded together. When you put gunpowder and a heavy metal ball (called a cannonball) into each barrel and light the fuse, it will shoot out two cannonballs at the same time.
But why would someone want to make a cannon with two barrels, you ask? Well, the idea was that it could do double the damage to the enemy during a battle. If one cannonball missed, the other one might hit the target. The double-barreled cannon was invented during the American Civil War, and some people thought it was a really cool and clever idea.
The problem is, it didn't really work as well as they hoped. The two barrels weren't perfectly aligned, so sometimes the cannonballs would go in different directions and miss the target altogether. And since the cannon was so heavy and hard to maneuver, it wasn't very practical for use in battle.
In the end, the double-barreled cannon became more of a curiosity than a weapon, and today there are only a few left in museums. But it's still fun to imagine what it would be like to fire off two cannonballs at once!