It’s the queen of complications and really understanding it is a lifetime study — but you gotta start somewhere. REVOLUTION brings you a brief introduction to some of the inside secrets of watchmaking’s most romantic complication
The minute repeater is both the most sophisticated of complications and the most atavistic — sophisticated, in that it requires enormous care and skill to make one that works at all, much less one that works well and sounds good; atavistic, in that it brings us back to the very earliest attempts to make mechanical timekeepers.
The first clocks weren’t made to be seen, but rather, heard, and when entire communities relied on clocks to tell the time, tolling the time was preferable.
It’s easy for us today to forget just how dark mankind’s nights were, in the days before ubiquitous electric light, but there must have been something very reassuring about hearing the time tolled on a bell — or, when the first chiming watches were made, on a mechanism that you could keep on your person. The repeater today no longer serves as a psychological hedge against the terrors of the night, nor is it useful in the same way that it once was, now that artificial light (and luminous watch hands, to say nothing of electronic watches that simply make their own light) has made it possible to see the time whenever one wishes. But the fascination of its mechanism still remains, and the childlike pleasure it offers is all the more rich for depending on one of the most complicated mechanisms in watchmaking.
The purpose of pushing the slide is twofold: to activate the chiming mechanism and also to provide the power necessary for the gongs to sound. When one pushes the slide, one winds up a second mainspring inside the watch. The energy for the going train — that part of the watch that carries torque to the escapement and balance wheel, which actually keeps time — comes from a spiral spring housed in a drum-shaped mainspring barrel. Operating the chiming mechanism takes up so much energy that to use the mainspring would run the watch down very quickly (and the loss of torque would tend to disrupt timekeeping as well). The solution, therefore, is to have a second mainspring, in its own barrel, to power the chiming mechanism.
Pushing the slide home, and then releasing it, lets the repeater go to work. The repeating mechanism is basically a tool for evaluating the internal state of a watch, and translating that information into chimes. A typical repeater has two hardened steel gongs, and first chimes the hours on the lower of the two, then the quarter hours, as a double stroke (ding-dong) on both gongs for each quarter hour, and then finally a stroke on the higher-pitched gong for each of the minutes. The maximum number of strokes a repeater will strike, then, occurs at 12:59, when a repeater strikes 12 hours, three-quarter hours, and 14 minutes (those wishing to test a repeater’s functioning can easily do so by setting the watch to 12:59 to see if the repeater sounds the correct time).