Tag Archive: clocks

Mechanical watches

It's an understatement to say that I have become fascinated with watches, especially mechanical watches. There is something about the precision engineering of a well made piece, its pulsating mechanical harmony, its artistic idea that satisfies the engineer, the scientist and the artist (to whatever degree it exists) in me. Because a mechanical watch really is a work of art since as an object of utility its pretty useless when compared to a simple quartz watch. Following is the story of the mechanical watch in a nutshell.

As I mentioned in my last post on the topic, all clocks and watches have a timekeeping source. In the grandfather clock it is the pendulum and in the mechanical wristwatch it's a balance spring. The Europeans (especially the Swiss and the English) had a huge headstart in designing and making precision mechanical wristwatches with the 2 towering figures of the field being Abraham Louis Breguet and John Arnold. Between the two of them they pretty much invented every important nuance of watchmaking. Everything was hunky dory for the Europeans before the Japanese entered into watchmaking in the 1960s. It was discovered that rather than using a balance spring as a timekeeping source, a quartz crystal can be used instead. Watches made using a quartz crystal would not only be much more simple to make but they would also be extremely cheap and much more accurate than the traditional mechanical watches. Swiss initially decided not to go the way of the quartz and got almost wiped out by the Japanese (Seiko, Citizen) and the Americans (Texas Instruments, National Semiconductors). The Swiss finally caught up in the quartz race through the formation of the Swatchgroup but they also repositioned the traditional mechanical watch as less of a utilitarian timekeeper and more of a thing of beauty.

Master watch-makers would toil away in the Vallée de Joux with their tweezers and their lenses, with their lathes and minuscule files and produce after months and sometimes years of hard-work a single mechanical watch, a stunning piece of craftsmanship and a true labor of love. These watches would have hundreds of microscopic moving parts, precision machined gears, elaborately patterned surfaces (Guilloché), jewel bearings to minimize friction, and automatic self-winding mechanisms. Since it is much more difficult to add additional functionality to a mechanical watch than it is to a digital watch, adding complications became a way to exhibit the artistry of an accomplished watchmaker. And with all those complications and all those gears ticking away in harmony, sometimes the watchmakers make the back and front transparent (Skeleton watch) and the beautiful clockwork of a well made mechanical watch takes its rightful position as a work of art. And you can be sure that horology of mechanical watches is more art than engineering by its vocabulary. It includes fine elegant French sounding names for different complications (Tourbillon, Sonnerie, Rattapante) and the famous watchmakers do their own versions of them. It's like Horowitz performing a Chopin piece or Van Gogh's doing a 'still life'.

And the result of all this is that even though these mechanical watches are not nearly as accurate as a quartz watch that you can get for 20 dollars, they can easily command prices in the high six figure range! And what do you get for all that? The following, for example:

Clocks and watches

I have lately been fascinated by how clocks and watches work and here is a little summary of what I've found. Timekeeping devices of the current form started all the way back in the 13th century for astronomical and administrative purposes. Many technological advances have occurred since then but the essential idea remains the same. In the broadest of terms there are two main parts of a clock: a timekeeping source and an energy source. A pendulum, for example, is often used as a timekeeping source and the reason why it is an appropriate one is an underlying physical principle. A pendulum of a given length completes each oscillation in precisely the same amount of time. Therefore, by adjusting the length of the pendulum, it can be made to complete each oscillation in precisely 1 second. If we were living in a world where there was no friction and no air drag then that is all that was needed. One could theoretically design a mechanism which would count every oscillation of the pendulum and that would be the 'second' hand and one could design additional mechanisms to 'tick' once for every 60 'ticks' of the second hand which would be the 'minute' hand and so on and so forth.

But we live in a world with mechanical losses which means that the pendulum cannot go on oscillating indefinitely without providing additional energy. In the medieval ages I suppose one could have imagined hiring an underling to stand beside the pendulum and give it a 'kick' every so often but it's not a very feasible solution even for an outsourced economy! So we have had to find additional 'automatic' sources of energy. This additionally energy can be provided in different ways. In big old pendulum clocks this was often provided by a falling weight and in the small wrist watches this is done through a wound spring but the essential idea is the same. Since there is a small and finite amount of energy stored in a falling weight or a wound spring it is important to regulate how this energy is transferred to the timekeeping source. This is done through a neat little mechanism called an escapement mechanism which ensures that one doesn't have to wind the clock/watch or change the batteries too frequently.

The whole field of horology can, therefore, be summarized in a few statements. The effort is to find a phenomenon in nature which is periodic and consistent and to keep it going by providing additional energy. Obviously the mechanical implementation is intricate fascinating and beautiful but that is the essence. Wrist watches obviously don't have oscillating pendulums but they have a similar timekeeping source - a mass rotating on a spring. Modern wrist-watches have another more accurate timekeeping source - a tuning fork made of a quartz crystal designed to oscillate at precisely 32,768 times a second and the energy comes from a battery. Atomic clocks have a yet more precise timekeeping source: atoms transitioning from one energy state to another emit radiation at a precise frequency. Since that frequency is constant it may be used as a timekeeping source. Atomic clocks based on Caesium-133 count 9192631770 cycles of the radiation emitted by the energy transition of the Caesium atom and the time it takes for those cycles to complete is equal to 1 second.

Following are some additional references which show the actual mechanisms of a clock:

 http://electronics.howstuffworks.com/gadgets/clocks-watches/clock.htm

http://www.youtube.com/watch?v=MDYjUDrCPv0&feature=g-like

Thoughts on buying a watch:

https://www.jenreviews.com/watch/

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