chronometer – Horological Underground

Zenith El Primero Chronometre Moonphase full servicing

Zenith ‘El Primero’ 410 CHRONO Moonphase full servicing Photos by Finn Marjoram Let’s review a nice example of the Zenith El Primero chronograph Cal. 410 – We’ll breakdown the full servicing process and some watchmaker pros and cons. We disassemble the whole movement to service. El Primero servicing cons – Too many parts! Too may […]

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Wittnauer/Longines Marine Deck Chronometer 24.41

Small Marine Chronometer, Longines-Wittnauer 1932, Switzerland Due to the absence of modern GPS systems and reliable long-range radio, sea voyages were unsafe without an accurate time meter. In order to navigate nautical charts, one needed to know the exact coordinates of the vessel, latitude and longitude. Finding the latitude is fairly simple – it can