Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
Rough Science
Explore the Challenges
Solve the Web Challenge
Meet the Rough Scientists
About the TV Series
Discover More
Site Map
Explore the Challenges

The Challenge: Make fireworks

Animated Roman CandleWe know how a rocket works, but how are Roman candles made?

"Roman candle" is the traditional name for a firework that has been around for centuries. In its simplest form, it's just a cardboard tube with a star sitting inside it. The fuse runs into the tube and ignites a lifting charge, popping the shell out of the open top and into the air where it explodes.

Cutaway of a roman candleThe lifting charge is black powder which when ignited produces a lot of gas pushing the bundle of stars upwards.

The best known Roman candle is the air-bomb which has stars that explode with a loud bang when they reach the right height.

Some Roman candles have more than one shell inside, stacked on top of each other, separated by a lifting charge. The fuse runs down the inside of the tube, igniting each charge in turn. Thus the shells are launched one after the other, with a pause between each one. This is known as a 'multi-shot' candle. The effects can be varied depending on the types of shell inside the tube.