Strip spring wrapped around the movement, against which the striker of a reapeating watch strikes.
The leading horologists of the late 17th century vied to create a chiming watch that would allow the time to be known on demand in the dark. Around 1680 they produced the first repeating watches. Since then, a number of watchmakers have contributed to the development of the repeater, improving its accuracy from the nearest quarter-hour to the nearest minute.
Abraham-Louis Breguet was also fascinated from very early on by repeating watches. In 1783 he created the first striking repeating watch to be operated by a gong spring rather than a bell, universally used hitherto. Initially rectilinear in form and mounted crosswise on the back plate, the gong spring was soon coiled up around the movement. It had the advantage of considerably reducing the thickness of striking watches, while at the same time making the tone more harmonious and discret. An exceptionally useful invention, it was adopted immediately by most contemporary watchmakers. Breguet also invented multiple striking mechanisms, or cadraturs, for repeating watches, notably for the quarters, half-quarters and minutes.
Today still, the minute repeater ranks supreme among horological complications. Universally admired, its intricate construction has remained the preserve of a few master watchmakers with the skill and patience to fit and adjust its delicate parts. Building a minute repeater is the task of an experienced watchmaker. Along with a musical ear, it demands great manual dexterity. The slightest mistake can ruin hours of work.
In 2008, Breguet came out with a new way of designing these technological marvels, fitting them with an entirely re-engineered movement.
Research on resonance conditions dealt in particular with the materials liable to produce and transmit an harmonious sound, as well as to preserve its purity in terms of intensity, richness and tone. This work has had a favourable impact on several parts: the gong spring, the gong holder, the striking mechanism barrel and the hammers, of which the energy is now significantly increased. Moreover, the harmony between the two gongs has been enhanced using psycho-acoustic tests and analyses that served to fine-tune clarity, sound resolution and auditory compatibility. Finally, the positioning of the gong holders has been modified so as to achieve the most crystal-clear sound possible within the case, which serves as a resonance chamber.
Breguet formerly used steel for the gong, which now has been changed to gold. Why gold? Breguet’s movement designers found that it produced the finest and richest quality sound. There was an additional bonus. Because the gong rings and the watch case are both gold, they share a similar intrinsic impedance. This makes the transmission of sound from the gongs to the exterior of the watch case more efficient and is the subject of a Breguet patent.
Sonneries occupy a special place in the constellation of Breguet timepieces. A Breguet is always a piece of art on the wrist, but the incorporation of rich sound opens up a rewarding additional dimension to the pleasures of ownership.