The jumping second – an exceptionally exclusive complication

3rd of September 2021

Pendulum clocks always have it …. the second hand that jumps from one index to the next, completely in time with the pendulum belonging to the clock. The length of a pendulum and thus its frequency determines the number of steps or jumps of the second hand per revolution, i.e. per minute. Long pendulums – few jumps, short pendulums – many jumps.

With the seconds pendulum, as its name suggests, this effect is most balanced. For each beat of the pendulum, the second hand takes one step, i.e. exactly 60 steps per minute. This is, so to speak, the absolute “master version”!

In the field of watches, this is completely different. Here, the second hand makes many small steps due to the high frequency of the oscillator, i.e. the balance wheel. To be precise, at a frequency of 18000 oscillations per hour, 300 steps per minute, i.e. 5 per second. You could think that the hand glides…. Nowadays, 28800 oscillations per hour are the norm at watches, which means 480 steps per minute and 8 per second.

Regulateur Classica Secunda

Let’s have look at the complication of the jumping second. Originating from the desire to be able to read off the seconds accurately, innovative watchmakers began early on to reduce the many small jumps of the second hand to the number 60. In 1754, Jean Romilly, who was born in Geneva and lived in Paris, was the first to achieve this. His watch was the ancestor of stopwatches, which made it possible to stop the second hand and thus measure time intervals to the second. The watchmaker Jean-Moise Pouzait also took up this challenge and developed this mechanism further in the direction of the chronograph we know today.

This very brief excursion into historical development already shows that the idea of the jumping seconds hand was already dormant in the minds of resourceful watchmakers at an early stage.

In modern times, however, since jumping second hands can be found in every simple quartz watch, this complication has almost been forgotten. One reason for this is surely that the value of a timepiece is defined by its mechanical movement and the almost gliding second hand. Accordingly, the jumping second stands for a quartz movement and thus also for a lower demand on the “engine” of a wristwatch.