In 2000, the master watchmakers at Audemars Piguet, drawing inspiration from three of the manufacture’s early watches (a time equation dating to 1900, a perpetual calendar aligned on the 12 o’clock – 6 o’clock axis that dates back to 1925, and a pocket watch perpetual calendar with a time equation and a traveling hand from 1928), created the first Jules Audemars Time Equation. Today, they have revisited this mechanical exploit to provide a superb piece that is an incomparable demonstration of savoir faire.






The Time Equation indicates exact noon as well as the difference between real solar time and ‘conventional’ time. This deviation passes from less than 16 minutes and 23 seconds on November 24, to more than 14 minutes and 22 seconds on February 11. This is what is called the Time Equation. It seems obvious that transposing this equation into a pure mechanical movement is not a simple task. So, this is where the ‘Time Equation Cam’ comes into the picture. Shaped like a kidney, it makes one rotation in a year, offering high precision since each day of the year is different.
Moreover, this same timepiece also indicates the times of the sunrise and sunset, according to the latitude where it was adjusted (the name of the reference city is inscribed on the edge). Even there, the difficulty is not trivial since, depending on where the wearer is located, the hours can vary considerably. At the poles, for example, there are solstices where the sun never sets.
Another exceptional indication is the astronomical moon. Adjusted in 2005 by a simple push on the specially designed corrector, the astronom-ical moon will require no corrections until 2127! It will only deviate from the real moon by 57 seconds 1/5 instead of 44 minutes and 2 seconds 4/5 for traditional lunar phases.
All of these indications, connected to the Perpetual Calendar, are aligned on the 12 o’clock – 6 o’clock axis and require no corrections until 2100.
The automatic Calibre 2120/2808, with a power reserve of 48 hours, equips this marvel, of which Audemars Piguet can make personalized versions depending on the location chosen by the owner.


Source: April-May 2005 Issue

More...Click here to subscribe to Europa Star Magazine.