Despite the hyperbole that sometimes accompanies news from the watch world, the truth is this: the hairspring and balance got together in 1660, Mudge made his first lever-escapement watch in 1755, and, with respect to repeaters, Barlow and Quare (both Englishmen) applied for patents for repeating watches in the late 17th century. Breguet developed the cathedral gongs still used in modern repeaters over two centuries ago, and the modern minute repeater — with its lever escapement, cathedral gongs and rack-and-snail striking mechanism — is, for the most part, unchanged since the early 19th century.
Improvements in watchmaking are largely incremental, not revolutionary, and for something as complex as a repeater, there’s a tremendous amount of incentive to stick to tried-and-true techniques and designs. After all, chiming watches — especially full minute repeaters and sonneries — are notoriously tricky to work on, demanding a level of patience, maturity and experience that makes them both the most charming of complications and the most intimidating. A conservative approach is both a matter of honoring tradition and staying out of trouble — better safe than sorry.
Which makes the last 10 years of minute-repeater design even more exciting. A serious study of repeaters gives the impression that one ought to be amazed when they work at all, much less when they work well. But there’s a new wave of repeaters that take the tried-and-true — if complex and temperamental — design of the minute repeater and tweak it with updates designed to give a new voice to watchmaking’s most venerable diva.
One of the most important aspects of minute-repeater design has to do with how sound is transmitted from the vibrating gongs through the rest of the watch — the case, dial, movement and caseback all affect the quality and quantity of sound. In a conventional minute repeater, the gongs are attached to a metal foot that’s part of the movement plate. That means that when the watch is on the wrist, sound has to travel through the movement plate, dial and crystal, as well as laterally through the flanks of the case.
To increase the efficiency with which sound is transmitted, Jaeger-LeCoultre, in 2007, introduced a system in the Master Minute Repeater in which the gongs were attached to a layer of metallic foil applied to the crystal of the watch. The rationale for using this system was to allow the energy from the vibrating gongs to reach the crystal unimpeded, which in turn is able to act as a more efficient resonator. The gongs used by Jaeger-LeCoultre also have a square, rather than round, cross-section — according to Jaeger, in order to increase the surface area struck by the hammers, allowing more efficient transmission of energy to the gongs. A square gong cross-section is also used by Cartier in the Rotonde de Cartier Minute Repeater Flying Tourbillon. Cartier’s Carole Forestier-Kasapi said in a recent interview with REVHLUTION that “Optimizing the contact area between the hammer and the gongs is incredibly important; it helps each strike to be more consistent, as well as more powerful.”
Different case materials have also been used — gold and platinum, while traditional, are also relatively dense and tend to absorb sound energy rather than transmit it efficiently. A light, rigid material is ideal for a repeater case, and innovations in the case materials of chiming watches include the use of stainless steel (by F. P. Journe), the use of titanium (most recently and memorably by Cartier in its Rotonde de Cartier Minute Repeater Flying Tourbillon), and even carbon fiber (the Hublot King Power Minute Repeater Chrono Tourbillon).