The tourbillon continues to provoke heated debate as to its manufacturing, the legitimacy of those who make it, and the relevance of the double, triple and other such tourbillons that are currently in vogue. The most violently-argued point is the difference between the tourbillon and the karrusel. As someone who has been personally involved in this polemic, I hope this article will put an end to the debate. According to the most authoritative texts on watchmaking and Swiss watch school manuals, the difference between a tourbillon and a karrusel resides in the speed with which the cage rotates and the position of the balance. When the cage makes one revolution per minute and the balance is mounted coaxially with the cage it is a tourbillon. Anything else is a karrusel.
Breguet, in his patent application, suggests an ideal speed of one revolution per minute, although he did himself experiment with other speeds. He also suggests mounting the balance in the centre of the rotational movement. In neither case does he claim these two points are set in stone. Nor does he mention which metal should be used to make the cage. The core of his invention is the roue immobile C.C. (the title of his patent application), in other words the fixed wheel which causes the cage to rotate. All known rotating systems, whether they make one revolution per minute or per day, whether their balance is in the centre of the cage or not, have one thing in common. They all have a fixed wheel and they are all tourbillons.
When Bonniksen invented his karrusel in 1892, he looked beyond the fixed wheel that was part of Breguet's invention and instead used a differential effect to make his cage rotate. In terms of timekeeping, there was little difference between the two and Bonniksen's invention can, for this reason, be deemed superfluous. However, for reasons that are anything but technical the intelligentsia has always refused to acknowledge his merit and, whenever a rotating system has failed to impress, have invariably labelled it a karrusel.
In collaboration with Blancpain and Mr Marc Hayek, we have decided to set the record straight, to give credit where credit is due and acknowledge Bonniksen's merit. We have made a watch with a karrusel escapement whose balance is mounted in the centre of a cage which makes one revolution per minute. Technically speaking, the result is the same as with a tourbillon. Aesthetically speaking, its greater complexity and the one-minute rotation give it a clear advantage. Among this tourbillon of opinions, it's my view that it's time to rewrite the school books.