How fireworks work!

Repeating aerial tubes are little more than several aerial shells fused together to go off in sequence, with a few seconds of delay between each shot. There are usually anywhere from 3 to 7 tubes which are glued down to a thick wooden base to stabilize the device. Each tube contains an aerial shell in the bottom, protected by a cardboard disk and a cap at the top of the tube. Holes are drilled in the bottom of each tube, and small chunks of fuse connect each shell to the tube adjacent to it. The tube on the end has a long fuse that runs outside for a few inches.

When that fuse is lit, the first shell fires. The lift charge of that shell ignites the chunk of fuse leading into the next tube, which then ignites a shell about four seconds later...and so on...

Roman candles are prsonally my favorite, you can get them fairly cheap, but if you want quality and not quanity you might want to pay a little more. After a clay plug at the bottom, the roman candle tube consists of alternating layers of lift charge, stars, and delay compositions (In most cases is saw dust). When the fuse enters the tube, it activates a slow-burning delay composition that makes its way down. Within seconds, the delay charge reaches the first star, simultaneously igniting both it and the lift charge below it, which blows the star out of the tube. This ignites another layer of delay composition, which will light a star and the lift charge to blow it out a few seconds later. This continues until every star has been blown out of the tube. Most roman candle tubes (the newer ones have a discription on what they do).

Mines are basically a ground-level aerial shell burst that is directed upwards. The bottom of the tube contains a black powder lift charge, similar to that found in a shell. When ignited, the lift charge engulfs the stars in flame, igniting them and shooting them out of the tube in a V-shaped pattern. The spread of the stars in the sky depends on both the length and the width of the mortar. Consumer mines are typically one shot per tube devices that are bunched together, resembling repeaters. Professional mines, however, are reloadable - the lift powder and stars are put in bags, which are lowered into the mortars and ignited.