The Da Vinci's perpetual calendar. From IWC. One of the masterpieces of the century.

Perhaps it seems presumptuous to use terms like "Masterpiece" and "century" in connection with an invention that is only ten years old. But as you discover more about its development- and its direct consequences - you realize you have almost no other choice. Because the Da Vinci's calendar and movement have links to more that a single century: they are a distillation of the centuries that lie behind us. And stretch into the seconds, minutes, hours, days, months, years, decades and centuries that lie ahead. The train of thought that takes us so far into the future goes back all the way to Da Vinci himself. Many of the revolutionary mechanical principles he developed have retained their significance in watchmaking down to this day. And they are principles on which we base our own work, helping us to surmount imagined barriers and make the apparently complicated simple enough for everyday use.

Take Kurt Klaus, for example, head of development with IWC. In the late seventies, he was so obsessed by the idea of a wristwatch with a mechanical calendar ( including a moon phase display ), programmed to remain accurate for over half a millennium, that he spent virtually all his working and leisure time hammering away at the problem until he hit upon an ingeniously simple solution. The answer was a perpetual calendar that would require no adjustment for a much longer period than any other before it and, unlike its predecessors, actually deserve the name "perpetual". But of course, if the days, weeks, months, years and phases of the moon shown by the movement were to be those laid down by the Gregorian calendar, Klaus's invention was also going to have a master the vagaries of that selfsame calendar.

According to Pope Gregory XIII's calendar, the solar- or "tropical" - year lasts exactly 365 days, five hours, 48 minutes and 46 seconds or 365.242192 days. We compensate for the slightly less than quarter of a day extra by adding the 29th of February every leap year. By doing so, we are of course overcompensating by a few decimal places, and so the 29th of February is omitted every 100 years. This, in turn, slight undercompensates, and so the leap year is left untouched every 400 years. And because this, too, amounts to a very slight overcompensation, the 29th February is omitted every 4000 years.

The task of a perpetual calendar, then, is to make allowance for the differing lengths of the months, the years and the centuries. Just like the one in the Da Vinci, which comes astonishingly close to solving the problem once and for all, and even recognizes all the leap years. Until the year 2100, that is. Because that year, according to the Gregorian calendar, there will be no 29th February, and so your watchmaker will have to make a tiny adjustment on the 1st of March, if at all possible. This is why you can allow your Da Vinci simply to follow the course of time and rely on it without worrying about adjustments or following complicated instructions for use. Every single one of its functions can be advanced via the crown. Your Da Vinci measures the exact time in seconds, minutes and hours, all by pure mechanics. And has a stop watch function, accurate to one-eighth of a second, which also counts the minutes and hours. Its also has an automatic- and purely mechanical - lunar display to show you the current phase of the moon. And displays for the date, day of the week and month, again all mechanical and all automatic. It knows automatically whether there are 28, 29, 30 or 31 days in the month. And, for the first time in watchmaking history, has a fully automated, mechanical, four-digit year display. It will go on displaying all this information accurately until the year 2499.

In a sense, it's a great pity that during this time you will probably never have the same view of the working of the calendar than you do here. Take the train between the anchor drive cog and the century display, for example, which has a reduction ratio of 1:6315840000: this is the first time such mechanism has ever been featured in a wristwatch, and every 100 years it causes the century slide to advance by 1.2 millimeters. During the time that elapses between two such movements, the balance completes no fewer than 25,245,000,000 beats.

All things considered, is there really a better way of describing it than as one of the "Masterpieces of the century". 

 The technical acheivement represented by "Ii Destriero Scafusia" from IWC is unequaled. It is an attempt to express the indescribable. We shall now try to do the same in words. "Tis true I know much, But I should like to know all." ( Johann Wolfgang Goethe, "Faust" )
That, unfortunetely is a wish we can only partially fulfill within the confines of this slim volume. Those wishing to know more should refer to our brochure marking the 125th anniversary of IWC, in which the "Destriero" is lovingly described down to the very last detail. Here we shall concentrate on only the most outstanding highlights of the most complicated mechanical wristwatch ever made. Its history actually dates back to the Middle Ages when any knight worth his salt was expected to take part in jousting tournaments to demonstrate his courage and prowess in battle. But as much as anything else it was the rider's valiant steed - his "destriero" as his mount was known to the Italians- which determined his success or otherwise. Several hundred years later some of the world's most talented watchmakers engaged in a contest, as fair as it was peaceful, in their own domain to create the world's most complicated wristwatch. "Il Destriero Scafusia", the result of their labours, has been showered with praise and admiration from all over the world. No more than two dozen of these superb thoroughbreds will leave the factory in Schaffhausen each year. Understandably, when you consider that the manufacture of a single hand-wound " Destriero " and gold or platinum case keeps a select team of master craftsmen busy for hundreds of hours over a period of several months. No fewer than 750 individually manufactured and hand-finished mechanical parts are assembled within the smallest of spaces. Minimal friction and wear is guaranteed by 76 rubies, and the watch has a total of 21 complex functions and displays.

Along with hands for the hours, minutes and seconds, the "Destriero" features a perpetual calendar which displays the date, day, month, year, decade and century. The moon phase display is the most precise of its kind ever to be featured in a wristwatch. In the space of 122 years, it deviates by just one day, and will require a minor adjustment after this time. The split-seconds chronograph can be used as a conventional stopwatch for timing actions and events in fractions of a second, minutes and hours, while the split-seconds hand makes child's play of recording intermediate and lap times. But you haven't heard everything yet. Probably the most complex mechanism ever created in watchmaking history, the minute repeater, chimes out the time in hours, quarters and minutes on two finely tuned gongs.

For the most complicated wristwatch in the world, the 31st of December 1999 will - literally - be the event of the century: Fin de siecle. Grande finale. The owner of a "Destriero" starts the chronograph at 11.59pm to follow the very last minute of the 20th century on the large sweep seconds hand. Half a minute later he pushes the repeating slide so that the last few seconds of the dying millennium can be chimed out on the gongs. At exactly midnight he pushes the button in the crown to stop the split-seconds hand while the chronograph sweep seconds runs on, uninterrupted. The minute hand slides into the 12 o'clock position, the minute counter jumps forward a position, the date display jumps forward a position, the date display jumps from 31 to 1, the day-of-the-week display moves from Friday to Saturday, the month display hand clicks forward from December to January, the lunar display advances a phase, while the year display disc, the decade display disc and the century slide all move into position to show the year 2000.

You would like to see how the handwound movement does all this. Nothing simpler. The "Destriero" has a see-through back cover of non-reflecting sapphire crystal that reveals the watch's fabulous mechanism for all to see. The plates are decorated with tiny hand-engraved letters, some just 0.68mm high. On the surface between is one of the classic repeating patterns of early geometry, while the field at the center is a tribute to Schaffhausen: it is dominated by the town's heraldic symbol, the Schaffhausen ram, proudly strutting on its back legs.

For connoisseurs the voyage of discovery continues with one breathtaking revelation after another. There, in all its glory, is the sophisticated split-seconds mechanism. And, then the watch's crowning glory: the tourbillon. If you are now hopelessly captivated by the split-seconds mechanism and the tourbillon, we suggest a simple remedy. Read on.

Which presumably explains why IWC took up the challenge in the first place. IWC's tourbillon is mounted on bearings on one side and is the first in the history of watchmaking to feature an eight-beats-per-second escapement.

Despite the fact that the rotating cage requires space, the balance remained approximately the same size. The balance was also made immune to an influence that often has negative effect on watch movements in this electronic age of ours, namely magnetism. Which called for another unique innovation: the tourbillon's cage is constructed of ultralight, antimagnetic titanium. The illustration shows the tourbillon in the "Destriero", rotating on its one-sided bearing. in all its intricate splendour. Weighing just 0.3 grams, it consists of more than 80 individual parts. All of which makes the "Destiero" from IWC even more attractive to the connoisseur.

The tourbillon in the "Destriero" consists of 100 individual
parts and weights just 0.296 gm:

1. Upper part of cage in titanium
2. Balance
3. Escapement bridge in titanium
4. Middle section of cage in titanium
5. Pallets
6. Escape wheel
7. Shock resist supports
8. Lower part of cape in titanium with pinion
9. fixed fourth wheel

Ref. 3735 from I.W.C.

An IWC worldwide exclusive. The little Da Vinci chronograph with perpetual moon phase display, in 18ct. gold with crocodile leather wristband and solid gold clasp. Screw-in crown. Water-resistant to 30 metres. Sapphire glass ( hardness coefficient 9 ).

The little Da Vinci chronograph with perpetual moon phase display from IWC:

Yet another great work from a group of old master. The life and work of the small Da Vinci live up to the honour of the name in every respect. For it has almost all the features that distinguish the Da Vinci itself. It displays the time in seconds, minutes and hours. And the date. And knows exactly what phase the moon is in. And will continue to do so for the next 122 years, accurate to the day. The stopwatch measures times of up to several hours to an accuracy of 1/4 second. All this with quartz precision. Ladies and gentlemen who appreciate the little Da Vinci for its size are not likely to miss a perpetual calendar.

Any manufacturer planning to equal, let alone surpass, IWC's original or more recent pilot's watches was clearly going to have to set his sights pretty high. And when you think about it, probably none of them were better qualified to do so than IWC itself.
In 1992, after three years' intensive design and development work, IWC launched a time machine that puts you in control at those critical moments when one stopwatch isn't enough but two are unnecessary. Because with the Doppelchronograph from IWC you can keep track of two times at once - such as an overall time and a single lap time, for example. And what exactly is the name of the stopwatch that gives you one-eight of a second mechanical accuracy? Why, the Doppelchronograph from IWC, of course, the watch that's given two-timing a good name.

 At IWC, we've always been ready to devote more time to developing exclusive products for lovers of fine watches in the firm belief that our efforts would be rewarded when we finally emerged ahead of the rest of the field. The Doppelchronograph could be another perfect example, particularly in the history of our pilots watches, with which it seems at first glance to be closely related. A tie that goes all the way back to the legendary "Mark XI". Look twice, however, and it becomes clear that the Doppelchronograph is well on the way to becoming a legend in its own right. Because the person who wears it is likely to end up getting more out of his or her time. Which is why it is equipped with a self-winding 79030 chronograph calibre movement with a 44-hour power reserve. It features push buttons for a number of different functions. Like the two at the 2 and 4 o'clock positions, which handle cumulative timing between an eighth of a second and twelve hours. And has a third button at the 10 o'clock position for all those times in between. We are referring here to the button which controls the split seconds hand, one of mechanical watchmaking's finest achievements. The split-seconds hand starts with the main stopwatch hand but can be stopped while the other continues to run, enabling the user to read off a lap time, for example. Another touch of the button synchronizes the split-seconds hand with the main hand again, and the user can then repeat the procedure, measuring two intermediate times in any one minute.

But stop. Impressive as the watch's unique features may be, we should not allow them to overshadow the traditional characteristics it has inherited from its forebears - particularly since they are so instrumental to the watch's high-flying performance under everyday conditions. The soft iron inner case, for instance, which protects the movement from the ultrahigh magnetic fields - up to 80,000 ampere/metres - often generated in cockpits. Or the solid, contoured sapphire glass, which stays right where it is even in the event of a drop in pressure. The screw-in crown. The patented IWC buttons. All of which gives it a head for heights. And makes it water resistant to 50m. At 42mm in diameter and 16.5mm thick, it is hardly one of watch making's triumphs in miniature. On the other hand, there is room for the word "Der Doppelchronograph von IWC" on the back of the case. Which means you even have it in writing. 

The Fliegerchronograph: Taking off to set a new world record.Ref. 3741

The physical resemblance IWC's Fliegerchronograph bears to its predecessors is written all over its face, but less obvious perhaps is the fact that it's also inherited a number of basic character traits. Such as an antipathy towards magnetic fields, which, thanks to an additional inner case of ferromagnetic soft iron, are prevented from affecting the movement,just like the large pilot's watch and the "Mark XI" in their own time. But it also represents the start of a new age in the history of chronographs. And has put a new generation on course for a new world record: It is the smallest in the world with analogue display. The diameter is 23.30 mm, height 3.70 mm. So that time can be measured in so many ways, it took: 27 wheels and gears, 26 springs, cams or levers, 25 rubies, 7 bridges, 32 screws - a total of 233 individual parts and countless ideas. The idea, for instance, of how to master all functions with only two step-motors: time display in hours, minutes and seconds. Date display with fast correction. Stop-second display ( accurate to 1/4 seconds ), minutes counter ( to 3 minutes ) and hour counter ( to 12 hours ) including incremental time counting. All simply operated by means of push buttons above and below the crown. The two quartz-controlled watch and chronograph movements are shock-resistant at several thousands of metres above the earth and up to 50 metres underwater.