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Editorial - The Art Of Writing Time

Editorial The Art Of Writing Time

Looking at watchmaking’s most versatile complication…

Until recently, it was believed that the chronograph was invented by Nicolas Rieussec in 1821 to time horse-racing events. The recent discovery of an even earlier device displaced this story — a Louis Moinet timing instrument was dated to 1816, and was created for the noble purpose of improving the precision of sea navigation. But origin stories aside, what makes a chronograph a chronograph? 

The ability to measure short sections of elapsed time is what distinguishes a chronograph from a regular timepiece. This is expressed in a chronograph’s start, stop and zero-reset functions. Of course, you could just check your watch at the beginning and end of whatever event you want to time and do some mental arithmetic, but having a chronograph function simplifies that process substantially. Chronographs mostly have a centrally mounted hand for elapsed seconds, on the same axis as the regular hour and minute indications. On chronographs with two subdials, one is usually to measure elapsed minutes and the other will be for the running seconds (which is linked to the main time-telling function of the watch). If there is a third subdial, it’s for the elapsed hours.

Why have this visually inconsistent separation of chronograph and time indications? Why not have the time (hours, minutes and seconds) told through centrally mounted hands and all chronograph indications displayed on subdials? It’s because one rarely needs to be utterly precise about the seconds when the time of day is involved — no one ever said “I’ll meet you at 2:30:45pm”. The benefit of having a large seconds hand when timing events, however, is immediately apparent.

Another identifying feature of chronographs is the presence of push-buttons on either side of the crown. These operate the starting, stopping and resetting of the chronograph indications. In watches with transparent casebacks, you can identify a chronograph movement via the presence of a column wheel or switching cam, which are the two methods of controlling a chronograph mechanism.

It comes as a surprise to most that the chronograph is one of the most challenging complications to execute. Of course, once the movement design is in place, producing it is (relatively) easy. The process of getting there, however, is frequently described by watchmakers as being far more complex than creating a tourbillon movement, because of the number of fine adjustments required to make a chronograph mechanism run smoothly. 

Horizontal VS Vertical Clutch

When you operate your chronograph, you are essentially starting up another timing system within your watch, in addition to the one that’s already running. A clutch mechanism is essential to this process, a system that allows the chronograph to smoothly engage and disengage with the underlying movement without wreaking havoc on the watch’s ability to keep regular time. The classical method uses a mobile gear that moves through a small arc and laterally couples and decouples the chronograph gears with the time-telling gear train. The newer method, pioneered by Seiko in 1969, is the vertical clutch, which utilises friction between the flat surfaces of two discs to drive the chronograph. The first method, being more traditional and time consuming, is seen as more prestigious. The second is highly practical (especially in terms of servicing), well suited for industrial production, and bestows an air of modernity.

Column Wheel VS Switching Cam

When the push-buttons on the side of your chronograph are depressed, they activate the chronograph function — but not directly! Instead, the force you transmit to the pushers gets fed through a control centre that delivers a regulated impulse to the relevant mechanisms no matter how much or how little strength you’ve actually applied. This control centre can take the form of a column wheel or stacked cams. The column wheel is more traditional, costs more to produce and results in a smoother, more consistent feel for the user when operating the pushers. It is hence used in higher-end — and higher-priced — chronographs. The cam system is robust, low-cost and readily adapted to high-volume production, but is characterised by unevenness in how readily the pushers can be depressed for each function.  An experienced watchmaker knows how to compensate for this, so a cam-system chronograph isn’t necessarily inferior to a column-wheel chronograph in user experience. By default, however, it’s safe to assume that a column-wheel chronograph offers better tactile feedback when the pushers are actuated.

Ultimately, each chronograph system has its advantages and disadvantages. It’s up to the buyer to choose what works best, within his or her requirements.

Lecture 1 Comment(s)

13 October 2021
Arthur Porter
Fun Commentary and very instructional. Thank you suzanne.

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