Horological Meandering

Jack Forster
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OK I'll bite. . .

. . . as I recall past threads on the subject-

Carriage speed doesn't define a tourbillon per se, IIRC (i.e. there are 12 second tourbillons et cetera).  Tourbillon is defined by the presence of an escapement and balance rotating around a fixed fourth wheel which may or may not be co-axial with the balance; if not, also IIRC the preferred term is "carousel-tourbillon" which is NOT a karrusel.

Karrusel tourbillon is a different animal; the term properly (again, IIRC- aw heck this whole thing is IIRC) refers to Bahn Bonniksen's variation on Breguet's basic concept.  In a Bonniksen karrusel the third wheel pinion turns a platform on which the escape wheel, balance, and lever are mounted- in this it's like the tourbillon but in a karrusel the fourth wheel is not fixed, it turns at the usual speed and carries the seconds hand (whereas in a tradition tourbillon of whatever type, the carriage rotates inside a fixed fourth wheel.

Daniels says that the karrusel works just as well for averaging poise errors (in a pocket watch, which is the context for his discussion) and they did very well in observatory time trials as did finely finished pocket tourbillons.

They generally are considered to be easier to construct and just plain less interesting to look at which is probably true- the platform on which the balance, lever and 'scape wheel sit turns pretty slowly and it just doesn't have the drama of a tourbillon.  Plus my guess is due to the thickness created by sticking the 'scape wheel, balance, and and lever on a platform that actually carries the balance cock as well and rides above the plane of the rest of the train, it'd make for a pretty thick wristwatch.

All by way of saying that in a wristwatch, it would suffer from all the practical disadvantages of a tourbillon in a wristwatch without any of the visual drama which usually excuses the presence of a tourbillon in a wristwatch.

Personally I happen to like them very much though, at least in a vintage context.  A wonderful, quirky, and in a pocketwatch very succesful contribution to chronometry .

Jack