A Catherine wheel is a type of firework which is very popular in Great Britain. In other nations, it is sometimes better known as a pinwheel. The basic design of a Catherine wheel includes a hub on which to rotate, with explosives mounted to it. When ignited, the hub spins, throwing sparks and flame from the firework. Readers of the Harry Potter novels may be familiar with the Catherine wheel, as one runs rampant, an apparently not uncommon problem, during Harry Potter and the Order of the Phoenix.

The firework is named, oddly enough, for a Christian martyr. Catherine of Alexandria lived during the fourth century CE, and was by all accounts an uncommonly well educated woman. In addition to being well read, she participated in debates with leading members of society, and successfully converted many highly placed individuals to Christianity. As a result, she was condemned to “breaking on the wheel,” a death which involved having one's limbs broken and threaded through an abundantly spiked wheel. The victim would succumb to his or her injuries, but only after several days. However, when Catherine touched the wheel, it broke, and she was beheaded instead.

How a firework came to be named after a brutal instrument of torture is unclear. The Catherine wheel does superficially resemble St. Catherine's wheel, as indeed any circular object would. It may be that fireworks were part of the festivities on her Saint's Day, November 25th. Fortunately, the modern Catherine wheel is designed to be associated with festivities, rather than martyrdom.

In the most basic of designs, a Catherine wheel uses a hollow tube filled with explosive powder. The tube is coiled around a central hub, and one end is lit. As the powder explodes, it turns the wheel, causing a shower of often multicolored sparks. In other designs, rockets are mounted on the Catherine wheel and simultaneously ignited. The rockets turn the wheel, create a showy display of sparks and flames, and sometimes ignite secondary rockets or tubes of gunpowder to prolong the show. Fancy Catherine wheels may even switch directions.

As with any firework, caution should be exercised when igniting a Catherine wheel. Most users prefer to mount the Catherine wheel to a fence or special launcher, which should be doused with water first so that it will not ignite. Take care to secure a Catherine wheel properly, as well, since runaway fireworks can do a great deal of damage.