Dr. N.
THE GREAT COMPLICATIONS OF HIGH WATCHES
Series of three articles on minute repeater, perpetual calendar and the tourbillon
The perpetual calendar
A complication is, in horological terms, an “additional function” in a watch, in addition to indicating the hour and minute.
The presence of the seconds indication is a complication. That of indicating the day of the month, a further complication. The indication of the day of the week, yet another. The indication of the month, yet another complication. The more advanced the watch, the less manual adjustment is necessary to keep it updated with the passage of time. In an annual calendar, for example, at midnight on April 30th the day of the month jumps to "1", skipping "31". In the most advanced of the complications foreseen in this field, the perpetual calendar, the watch is able to keep track of leap years, adding February 29th every four years. This allows the clock to remain correctly synchronized with the passage of time for 100 years.
Why the perpetual calendar
The need to measure the passing of the hours during the day gave rise to watchmaking. The need to measure the passing of days over the course of the year gave rise to the calendar.
The calendar as we know it today required a long period of development to reach today's precision. The first to divide the year into 12 months was Julius Caesar. The great Roman statesman relied on the best astronomers of his era to calculate the correct length of the year, which was estimated at 365 days.
In the 10th century, Pope Gregory XIII noted that Caesar's calendar had accumulated a gap of about XNUMX days, compared to the real time measured by astronomers. The need to bring the human calendar back into sync with the astral calendar has considerable practical relevance for the Pontiff and for Christianity as a whole. The calculation of the day on which Easter falls must be precise and unambiguous. This is to ensure that all the faithful can celebrate the fundamental holiday at the correct time, which falls on the first Sunday following the first full moon of spring.
Gregory, like Caesar 1500 years earlier, also summoned the best astronomers and mathematicians. It is established, also based on Copernicus' calculations, that the duration of the solar year is 365 days and 6 hours: to take into account the additional hours, every four years, a day will be added. And the gap accumulated in the previous 1500 years? Gregorio has a simple solution: skip ten days all at once. We went to sleep on the evening of Thursday 4 October 1582, and woke up the next morning, Friday 15 October 1582. The Orthodox Churches did not accept the new Catholic calendar, and this is why even today in Russia Christmas is celebrated on the 7th January. For civil purposes, however, the Gregorian calendar was adopted by Russia in the Soviet era, and by Islamic countries during the twentieth century: with very few exceptions, this is the calendar used throughout the world today.
The bull with which Gregory XIII introduced the new calendar in 1582, which is still in use today
The difficulties of watchmakers
After the reform of Gregory XIII, it took almost two centuries for watchmaking to be able to develop mechanisms capable of automatically adapting to the calendar without manual intervention. The biggest difficulty is keeping track of leap years. It is in fact necessary to put into operation, only once every four years, a mechanism that triggers exactly at midnight on February 28th of the leap year, causing the calendar to mark February 29th instead of March 1st. This mechanism must then reset at midnight on April 29th, therefore remaining inactive until April 28th four years later.
The difficulty was overcome for the first time by Thomas Mudge in 1762. Mudge created a pocket watch which, two hundred and fifty years later, was purchased by Patek Philippe to display in the watchmaking museum of the very prestigious Swiss maison.
The first perpetual calendar watch, made by Thomas Mudge in 1762
The perpetual calendar watch today
It's more than fitting that it was just that Patek Philippe to purchase the first example of a perpetual calendar watch at auction, as this company, more than any other, has associated its name with the complication we are dealing with over time. The first wristwatch equipped with a perpetual calendar was in fact made in 1925 by Patek Philippe, and Patek Philippe, in 1941, created the first mass-produced watch with a perpetual calendar, the reference 1526. In 1962, it was again by Patek Philippe the first self-winding watch with a perpetual calendar, the reference 3448. Even today, i Patek Philippe perpetual calendars they are among the most loved and sought after by fans of the brand.
A splendid example of a perpetual calendar: the Patek Philippe ref. 3970G
As mentioned at the beginning of the article, the perpetual clock is able to correctly keep count of the days, over the course of an entire century. This is because the calendar born from the Gregorian reform has a further complication to take into account. Years that are multiples of 100 are leap years only if they are also multiples of 400. Therefore, while the years 1600, 2000, 2400 etc. are leap years, the years 1700, 1800, 1900, 2100 etc. they are not, not being multiples of 400. The next frontier of the perpetual clock, already tested by some manufacturers, is therefore to create timepieces that do not need to be adjusted once every century.
Contact Dr. N at dr.n@chronosect.com
