How do fireworks get shoot into the air?

             Rocket fireworks have a aerial shell to shoot themselves up to the sky and explode. Modern fireworks use compressed air to shoot themselves into the air and then use an electric timer to explode. Most fireworks use gun-powder to launch up and explode. The firework function as a two stage rocket. The first stage of the fire work areal shell is a tube containing gun-power. There is a hole at the bottom of the firework so the expanding gases from the gun-powder propel the firework into the air rather than exploding. The second stage of the areal shell is a package of gun-power, oxidizers and colourants. This will determine the shape of the firework.