In the days when pocket watches were more common than they are today, it was a very real problem to ensure that they kept accurate time despite the effects of gravity.

In order to address that issue, a watch escapement known as the tourbillon (French for ‘whirlwind’) was invented by Abraham-Louis Breguet. It was patented in 1801.

In simple terms, the escapement is mounted in a rotating frame, which by being in constant rotation, neutralises the effects of gravity.

These days, there is no practical need for the tourbillon as advancements in technology mean that accurate timekeeping is a lot easier to achieve. However, because of the skill etc involved in making the tourbillon, it is still used by makers of expensive watches to denote quality and skill.