Double Tourbillon "Quai de l'Horloge"

The examination of the Classique Double Tourbillon “Quai de l’Horloge” begins, of course, with its complex marriage of two tourbillons that rotate with the hour hand. A hint of the complexity of the movement emerges from the number of parts housed within the rose gold case: 740 individual components. The tourbillons which define the movement and dominate the visual presentation of the timepiece are one of the most important inventions in the history of watchmaking. Conceived by Abraham-Louis Breguet and patented in 1801, the tourbillon is not only a signature of the house, but it has also universally become a symbol of watchmaking prowess.

The idea underlying Breguet’s innovation is counteracting the very small rate errors produced by gravity and frictional forces acting upon the rate keeping components – the balance wheel, hairspring, and escapement – found in every mechanical watch. With a standard construction where these elements are fixed in the movement, in some vertical positions of the watch, gravitational and frictional forces can cause slight increases in the running rate of a watch; in other orientations, slight decreases. The genius of Breguet’s invention is that by constantly rotating the rate keeping elements over 360 degrees, thus passing through both increased rate positions and slower positions, those small errors will compensate for each other. The Quai de l’Horloge’s combination of two tourbillons goes further. The two tourbillons’ rates are joined together with an element called a “differential”. 

The differential mechanically averages the rates of the two. For example, if one of the tourbillon’s average rate is 1 second a day fast and the other 1 second a day slow, the rate of the combination would be perfect running or 0 seconds per day of error. Another example: if one runs 2 seconds per day fast and the second 1 second per day slow, the differential’s combination will produce a rate of 0.5 seconds per day fast.

Breguet has added an exceptional dimension to what is already an ultra-complex combination. The two tourbillons have been mounted upon a solid gold plate, which rotates in step with the hour hand. Not only does this add to the visual charm of the timepiece, for the orientations of the two tourbillons are constantly changing throughout the day, but, in effect, this extra rotation is itself a form of another tourbillon as it steadily changes the positions of the components over 360 degrees. Thus, each of the tourbillons rotates once per minute while at the same time both are rotated once every twelve hours.

 

A hint of the complexity of the movement emerges from the number of parts housed within the rose gold case: 740 individual components. 

The Classique Double Tourbillon Quai de l’Horloge opens up this theater of motion with a three-dimensional display of the key movement components. Logically, a tour to explore the hand finishes of what is no less than an architectural structure is best done level-by-level starting with the gold plate upon which the tourbillons are mounted. The plate has been guilloché by hand with a flinqué rayonnant motif, but with a twist. 

The word “rayonnant” means “radiant” and well describes the pattern which radiates or “fans out” from the center of the movement. Somewhat of an accident during the development of the pattern brought an unexpected embellishment. The guilloché machine, hand operated as with all guilloché machines at Breguet, had been in use for creation of a varying pattern of waves for the dial of another model. 

The guilloché craftsman given the assignment to produce some trial or prototype disks for the Quai de l’Horloge decided that since he was only going to prepare a prototype of the disk, the wave cam could remain on the machine. The result was surprising and intriguing. The wave cam produced a design where the radiating lines from the center were spaced at slightly varying angles. Though not the goal of the prototype trial, the 
designers found that subtle variation in the angles brought added interest to the motif so that it was chosen as the final design.

A testament to the uncompromising devotion to finishing details is the underside of the gold rotating plate. Although it will only be seen by the watchmaker assembling the watch or later the watchmaker servicing the timepiece, the hidden underside has been given a perlage decoration.

Surrounding the rotating solid gold base plate is a fixed ring, also carried out in gold and likewise guilloché with the same pattern but given a contrasting tint as it has been rhodium plated. One segment of the ring in the region of the crown has been fashioned in brushed steel to provide extra rigidity for the winding mechanism.
 

Moving up a level are the two winding barrels. The double tourbillon has been designed with two mainspring barrels, one for each of the tourbillons. In many ways, one can think of its construction as joining together two watches. The presentation of the two barrels on the dial side is dramatic. Each barrel has an upper bridge for the arbor bearing an elaborate open worked “B” design. Visible through the bridges are the mainsprings nestled inside the barrels. Each “B” itself is a chef oeuvre. All of its surfaces have been painstakingly hand finished. 

Eagle eyed savvy collectors, who prize traditional hand-applied finishes in watches, closely inspect every movement searching for what are called “interior angles” (angles rentrants). Finished interior angles on movement components are an unmistakable sign that tradition has been respected and that the watch is the product of true expert finishing handcraft. Think of the letter “Z”. At the upper left and lower right are the sharp interior angles where the top and bottom join the slanting bar.

In watchmaking, applying a fine anglage finish to a sharp interior angle can only be done in the time-honored manner using a succession of files – each one finer than the one before – followed by wood burnishing with fine polishing compounds in another succession, each one finer. Then at the end, to bestow a final gleaming touch, polishing with the stems of the gentian plant which grows wild in the Vallée de Joux. The challenge in achieving a lustrous and uniform anglage finish to the edge of movement components fully respecting the hand filing techniques is enormous, particularly when the shape of the edge is complicated. Only the most experienced finishers are able to master the finishing of a form as intricate as the “Bs” of the Quai de l’Horloge. In order to avoid this multi-step time consuming and demanding artisinal hand craft, how do many in the watch world streamline and simplify anglage finishes? By designing movements with rounded interior junctions instead of crisp interior angles. 

These round intersections and shapes can be finished relatively quickly using an electric tool resembling a battery powered toothbrush. As for the “B” design on the barrel bridges?  No such expedient. There are no fewer than 25 sharp and complex interior angles on each one!  Thus, many hours of hand work by master finishers have been poured into just the beveling of these two components. The top surface of the “Bs” likewise has been hand finished. Using a succession of files and wood, the top has been given a subtle rounded profile. Not to be overlooked are the sides which have a hand applied straight line brushing.
 

The tourbillons themselves shine with their hand applied finishes. Examples, best appreciated viewing with a loupe, are the fine mirror polishes, achieved by hand, on the hairspring stud; anglage on the arms of the carriage; and finely done sharp interior angles at the junction between the arms and the exterior ring. The mirror polish on the stud cover, like anglage, presents its own set of challenges for the finishing craftsmen. The surface must be flawless, admitting of no scratches or other imperfections. Deft touch is called for as the component is polished against a zinc block, the craftsman judging progress by feel.

Moving up another level, two further details show the handwork that distinguishes this timepiece. The hour hand element is extraordinarily complex as it serves two purposes. First is the blue hued steel element which is, in fact, the hour hand and, as well, the top bridge of one of the tourbillons, and the steel extension that is the top bridge for the second tourbillon. 

The blued portion serving as the hour hand has been given a rounded profile, termed bercé, achieved by hand filing. That in and of itself is extraordinarily demanding as it calls upon the finisher to round the arm uniformly along its length. 

Even more difficult, though, is the intersection between the hand and its round center. Like all sharp interior angles only hand filing followed by wood can produce a crisp line. However, since the hand is rounded, extra skill is required. The extension has slightly different hand finishes: a mirror polished top surface and sharp interior hand filed junctions at each end.
 

The hour hand is extraordinarily detailed in its finishing, combining round surfaces, sharp interior angles, and mirror polishing, all of which must be realized with careful handwork. 

The back plates of the Le Quai de l’Horloge are an artist’s tableau. Here, upon the solid gold plates, Breguet’s engravers have created a three-dimensional bird’s-eye view of Paris at the turn of 18th to 19th century. Flowing through the scene is the Seine as it passes by the Île de la Cité and under the Pont Neuf, the oldest standing bridge in Paris. The buildings fronting the river lie along the Quai de l’Horloge. Of course, at the center is number 39, Abraham-Louis Breguet’s workshop. 

The engravers not only delicately carved, in exquisite detail, the form of the buildings, their facades, the windows, the roofs, and the landmark bridge with its distinctive arches, bastians and elaborate decorations, but animated the scene with pedestrians, horse drawn carriages, and boats in the river. Each of these figures, including the clothing worn by the men and women depicted, is carried out in such perfect minutiae so as to demand viewing through a loupe for full appreciation of the artist’s craft.

Sunlight and shadow effects are created by deft touches of the artist’s almost microscopic awls whose special shapes are dictated by the light effect being engraved. Particularly stunning in its vivid detail is the smokestack on the vessel floating upon the Seine. Even though the plate is flat, the smokestack appears to rise up from the surface of this engraved painting. The artist’s sense of light and shadow and the special engraving techniques for each lie behind the trompe l’oeil effect.
 

The last dial side element is the sapphire chapter ring. Its indexes are laser engraved and filled with blue lacquer.

Breguet has enhanced the view of all of these dial side components by fitting the Classique Double Tourbillon “Quai de l’Horloge” with glass box style sapphire crystal. Rather than stretching straight across a conventional bezel, the crystal rises upwards from the case body, its sides essentially replacing a conventional bezel. This design brings extra light to the interior showcasing the elements and fine finishes.
 

The open architecture of the movement, together with the glass box shaped crystal, bringing enhanced illumination, showcase the fine finishes and theater of motion of the tourbillons. 

A fine timepiece can distinguish itself on many levels. It may be with cutting edge mechanics. It may be with outstanding artisanal finishing. It may be with exquisite artistic crafts bestowed upon it. Rarely does one watch excel on all three. This truly is the Breguet Quai de 
l’Horloge, a fitting embodiment of its storied name.