In A while, Arnold’s chronometers would serve important roles in legendary voyages, as being the instruments aided navigators calculate their longitude. Declaring the winner of the race to develop the initial automatic chronograph in 1969 is contentious business enterprise, so Zenith’s “El Primero” moniker is arguable. That’s the name on https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/