Shell
Shells are fired from a tube or mortar. Mortars are usually made from spiral bound card but can be plastic or steel. (It should be noted that plastic or steel mortars should be buried in sand to reduce shrapnel in case of a misfire.)
A shell consists of a spherical, hard paper casing packed with stars which has a burst charge in the centre. There is a timed delay fuse connecting the burst charge to a 'bag' containing the lift charge at the bottom of the shell.
When a shell is lit, the ignition fuse ignites the Pipe Match leader which carries the fire to the lift charge. The lift charge ignites, ejecting the shell from the tube and igniting the Timed Delay Fuse. At the apex of the shell's trajectory, the delay fuse ignites the burst charge which ejects the stars in the classic 'shell burst' pattern.