Fire is one of the most useful natural phenomena in the world. When early humans first captured fire from naturally burning areas, and later generated flames themselves, their lives changed dramatically. With this understanding of nature, they could have light and heat after nightfall, and they could cook their food.

Photo courtesy NARA
But fire is also one of the most dangerous phenomena in the world, and this fact wasn't lost on early humans. Archeological evidence suggests early hunters used fire to flush out their prey, and some groups may have used it to fight other humans. Throughout history, fire has proven to be an extremely effective, devastating weapon.

One of the most interesting developments in fire weaponry was the flamethrower. The modern flamethrower came about in the early 20th century, but the original idea is actually thousands of years old. In this edition of HowStuffWorks, we'll look at these early pyrotechnic weapons, as well as their modern counterparts, to understand what they do and how they do it.