Tourbillon

Tourbillion is a French word that you will hear used time and time again in horology and watchmaking, often you will see it as a prestige inclusion on expensive and high end timepieces. The actual word Tourbillion translates into English as "whirlwind" and is simply used to describe an escapement (the escapement is the part of the watches mechanism that prevents the mechanism unwinding) that is designed in such a way as to counter the effects of gravity and anything else that will affect how accurate the timepiece is.

The actual process of crafting a tourbillion is very fine, detailed, precise work and requires a master horologist of many years experience, hence why they are so highly sought on certain timepieces as used as unique selling points by certain manufacturers. The tourbillion works by mounting the escapement in a frame that rotates which means that the effect of gravity is cancelled out when the escapement is rotated. The tourbillion was initially developed for use in pocket watches because the effect of gravity on their mechanisms was amplified by the position they were carried in throughout the day. The generally accepted rotation speed of the tourbillion mechanism is one rotation per minute, although some manufacturers do vary this on specialist pieces.

The tourbillion is the most challenging watch mechanism to make (although it is not considered a complication). The design and engineering principles behind the tourbillion and the sheer quality of craftsmanship that must go into each one makes them highly desirable even though they are not required to help keep the timepiece accurate in modern designs. You can expect to pay tens of thousands of pounds for most tourbillion wristwatches, although there are some less expensive versions on the market that are manufactured using Chinese made movements rather than the more traditional Swiss movements. The Tourbillion is usually mounted in such as way as to be visible through a window or the back of the watch, occasionally the tourbillion also works as a second hand due to it's rotation speed.