Fireworks have been around for a long time and the basics of how they operate have not changed much. All fireworks are constructed in generally the same way, although firework manufacturers are constantly working to produce brighter colors and more impressive displays.
A simple form of firework is the single tube fountain. This type of fountain is made up of a cardboard tube which is attached to a plastic base. The tube sits straight up and down on the base. At the top of the fountain is thin paper which protects the tube during transport. In the paper is a wick which is lit to set off the firework. The wick fits inside a clay plug called the “choke.” The choke has a hole drilled into the middle of it in and the wick goes down through this hole. The choke is important to the fountain because it causes pressure to build up inside the tube. Because of this pressure, the sparks and gas come out of the fountain at a higher velocity and allow the sparks to appear like they are shooting out of the top of the fountain. In the middle of the fountain is black powder, otherwise known as gun powder. Gun powder is made up of sulphur, charcoal and potassium, and some fireworks also include aluminum which helps to brighten the sparks. The black powder is often layered inside the firework which is how the firework changes colors.
Repeating fountains work in a very similar fashion. A large outer tube will contain many smaller cardboard tubes. A large fuse comes out of the top of the larger tube and lights the first smaller tube. When the powder has burned almost to the bottom of that tube, a second fuse is ignited. The pattern continues until all tubes have been lit. Sometimes a connecting fuse will connect more than one tube which allows for a larger color display to take place. Although repeating fountains are typically more expensive, they last much longer than single tube fountains and can produce more impressive effects.
The other popular form of fireworks is sparklers. Sparklers are made in two ways. The older type of sparklers uses a thin metal wire. This wire is coated with a metallic composition that burns slowly and produces sparks. Newer sparklers work like miniature tube fountains. The stick is made up of wood and has a small cardboard tube attached which burns down and produces sparks.