The Swiss invent a novel watch spring

DIGITAL ELECTRONICS has transformed many consumer-goods industries, but analogue niches survive and even thrive. Vinyl records have staged a comeback, sales of printed books have been growing faster than e-books in some markets, and cameras that use old-fashioned film have seen a bit of a revival. The Swiss are also still happily making mechanical watches, particularly the high-end sort, and last year exported more than 7m of them worth some SFr15bn ($15bn).Whereas an electronic watch uses a battery as its power source and a quartz oscillator to measure time, a mechanical watch relies on a set of gears and springs. A coiled mainspring stores the energy needed to turn the gears, and the movement is regulated by an oscillating balance wheel controlled by a tiny hairspring. Mainsprings and hairsprings have to be made of special alloys that retain their physical characteristics as much as possible in different temperatures, so that the watch maintains its accuracy wherever its wearer ventures.