The design and development of these prized and highly specialized timepieces requires great skill and utmost precision. A complication can easily consist of several hundred different parts, taking seasoned artisans days if not weeks to assemble. The leading manufacturers create many of the single watch parts down to the smallest screw and assemble the timepieces by hand.
Apart from indicating the time, a classic chronograph offers an additional timing functionality commonly known as a stopwatch function. Intervals of time can be measured by means of a mechanism which can be started and stopped and returned to zero if needed. Seconds, minutes and hours intervals are often displayed on subdials, the mechanism is controlled via one or more pushers located on the side of the watchcase. Allowing for incredible accuracy, some chronographs measure up to a hundredth of a second, others can measure for up to twelve hours.
Indispensable in the world of sports and racing, the chronograph could well be considered the most renown complication.
Invented in the 18th century, the perpetual calendar is based on the Gregorian calendar. Considered a ‘grand complication’ in the world of haute horlogerie, the highly refined perpetual calendar displays the day, date and month. Some rare watches even display the century and millennium. A perpetual calendar is a feat of micromechanics and a challenge for even the most skilled of watchmakers. It automatically sets the number of days in the month and knows when to adjust for a leap year. Keep this timepiece wound for an accurate reading and let the fortunate heir to the masterpiece know that the perpetual calendar will need to be corrected by one day on March 1, 2100.
Originally referred to as ‘Réserve de Marche’, the power reserve indicator is designed to present the amount of running power left in a mechanical watch. The power of these wristwatches is directly linked to the remaining tension of the main coiled spring. The power reserve thus depends on the length of the main spring, a reserve of 40 to 50 hours is the most common. The amount of power left is indicated on the dial by translating the tension of the main spring onto a sub dial gauge, where the information can be viewed at any given time.
Just like the perpetual calendar, the annual calendar displays the day, date and month. It will however, need minimal adjustment once per year in February since the calendars of these timepieces are based on 31 and 30 days per month.
This complication displays the progression of the moon phase according to the cycle. The curved aperture on the dial enables a glimpse of one of the two moons which are featured on a rotating disc. The turning disc moves the moon from waxing to waning. Available in a variety of styles, some moon phase complications feature a highly eclectic three-dimensional display or will indicate the age of the moon in relation to the last new moon. Astronomical moon phases are more sophisticated and accurate than regular moon phases and will need fewer corrections.
Mainly a decorative element, the day and night complication presents the time of day. Paired with a second time zone, this complication becomes quite useful in keeping track of the time of day elsewhere. Simple indicators feature a rotating disc with two colours which are presented through an aperture similar to a date window. Others feature a sub dial with day and night indication by means of one hand travelling from the depicted sun to moon.
Dual Time Zone watches have the ability to display the local time as well as the time in a second zone. Perfect for an at-a-glance check of the time in a different zone, it will help you avoid making untimely calls. One popular extension of this function is the GMT tracker, useful in particular when flying through different time zones. GMT was created during the peak of naval expeditions and was later followed by UTC, the Universal Time Coordinated, replacing the meridian line that passes through Greenwich. GMT remains popular though, and the watches often display time with a second hand, the 24-hour hand set to GMT.
Invented by the Swiss watchmaker Breguet and patented in 1801, the tourbillon style escapement creates a type of cage which, at the time compensated the negative effects of gravity on the precision of pocket and coach watches. In the 20th century, the tourbillon was added to wristwatches and presented as a visible element and part of the dial. Thanks to their complex engineering, design and delicate structure, tourbillons are highly appreciated by connoisseurs.
More complex than the dual time watches, the world timer typically depicts the time by two separate bezels. Trying to wrap your jet-lagged brain around various time zones in different countries? The world timer is for you. The inner bezel features the 24-hour display which makes one complete revolution per day. The outer bezel lists the major cities in each of the 24 main time zones. Set the home time zone on the 24-hour bezel, the point where the ring lines up with the zone you are looking for indicates the time.
The repeater was especially useful prior to the application of luminous coatings to hands and indices. Depending on the type of complication, a repeater can indicate the hours, quarters of an hour, five minutes or even minutes by chimes or rings. The number of rings indicates the time with different chimes for the hour, the quarter hour and minutes. This was particularly useful in the dark and helpful for the visually impaired. Today, these pieces are sought after by watchmaking aficionados and the lovers of musical automatons alike.
The retrograde complication's origin can be traced back to the late 17th century, when some makers of fine pocket watches began to diverge from the norm. Usually pocket watches and, indeed, our wristwatches today, indicate the time by means of hands rotating on an axis. The retrograde function however, works differently. The hands move along a semi-circular path and, when they reach the end, snap back into their original position and begin their journey anew. This extraordinary feat of engineering is accomplished by utilising a complex system of springs and gears. Having fallen a bit out of fashion, the retrograde complication has had its revival in the middle of the 20th century. Today, retrograde hands are often combined with jumping indices and can be found in exceptional timepieces indicating the date, the hours and, in some instances, even the seconds.
With the advent of smartphones, this complication lost much of its former popularity and thus finds its way into few timepieces today. Fifty years ago however, a slide rule was a valuable tool for everyone who had to calculate anything in their daily lives. The combination of a mobile scale on the watch's bidirectional bezel and a fixed one on the dial made it possible for engineers, pilots and many others to perform complex calculations on their wrists within seconds. Next to simple multiplications and divisions, a slide rule could also be used to calculate fuel consumption, speed and distances and for the conversion of currencies and temperatures. Nowadays, only a few watch brands with a strong heritage in the production of functional timepieces for aviation or the industry still include this once essential complication in their timepieces.
