How can the precision of a watch movement be improved? By accelerating the frequency. A shock treatment that the caliber must be able to withstand. All the more so since, beyond the risk of mechanical problems, this very high frequency promises to be energy-hungry, devouring the power reserve. Today, the most common frequency for a wristwatch and its spiral balance, the beating heart of the movement, is 4 Hz, or 28,800 vibrations per hour. One hertz more, and it rises to 36,000 vibrations per hour.

Longines recently relaunched one of its high-frequency icons: the Ultra-Chron, born in 1968. It was the world’s first diving watch to beat ten times per second. Inside the new Ultra-Chron beats caliber L836.6, a high-frequency “in-house” movement whose balance-spring oscillates at 36,000 vibrations per hour. This is a way for the company to continue its success story, which began in 1914 with 1/10 movements.^e of a second) and…