Urwerk is a company whose work I’ve admired for many years, and among the independent brands, they’re one whose products seem remarkably consistently appealing. The system of satellite wheels that are at the heart of Urwerk designs have proved a remarkably fruitful base on which to build the brand, and since the first Urwerk – the UR-101, which you might say is the ur-Urwerk – was released in 1997, they’ve gone on to produce a large number of different models, ranging from highly technical products focused on chronometry, like the EMC, to very design-forward watches such as the rather saurian UR-T8.
While in Geneva for the GPHG, I visited Urwerk’s workshop and office, located just slightly back from the south bank of the Rhône, which bisects the city as it flows out of Lake Geneva (Lac Léman). The workshop contains, in addition to facilities for administration of the small company, and watchmaker’s benches, several fascinating clocks.
The first of these sits – it seems at first rather incongruously – next to a large original-series Star Trek poster on the wall just above an impromptu bar in the conference room. It’s a pendulum clock with a brass bob and wooden rod (wood being generally less susceptible to variations in length due to temperature change than metal, although it is affected by humidity) and though it’s a respectable looking piece of work at first glance, it doesn’t seem terribly remarkable in any respect until you look at the dial, which is unlike the dial of any watch or clock I’ve ever seen.
The regulator style dial might fool you for a moment into thinking this is a conventional clock, but not so. The clock does tell the time but in a very interesting fashion – it marks off the number of kilometers, per day, that you would travel if you were standing on the Earth’s equator for one day. The upper small dial counts off zero to ten kilometers; the main dial and hand counts off hundreds of kilometers; and the small dial at the bottom, which carries the name of the maker – French clockmaker Gustave Sandoz (1836-1891) – counts off thousands of kilometers, up to 40,000. The actual circumference of the Earth at the equator is about 40,070 kilometers so 40,000 is a reasonable approximation. The clock uses a fairly standard deadbeat escapement, and won two prizes at the 1892-93 Chicago World’s Fair, which was held to celebrate the 400th anniversary of the discovery (or so it was then thought) of the New World by Christopher Columbus (the exhibition was also called the World’s Columbian Exhibition).
The second clock faces the door just as you come in, and for good reason, as it’s the clock most obviously related to the wandering hours complication, which is the basis of Urwerk’s wristwatches.
This clock was made, so Urwerk co-founder Martin Baumgartner told me, around 1680, and it’s a very early version of the wandering hours complication – both the maker and the artist responsible for the dial decoration are unfortunately unknown (the movement is unsigned). The clock is Italian – the very first known wandering hour clocks were supposed to have been made by the Campani brothers, in the 1650s; the brothers made one such clock at the request of Pope Alexander VII, who wanted a clock that could easily be read at night. Wandering hours clocks were originally intended as night clocks; you would put a small oil lamp inside the case, which would illuminate the hour from behind (this clock has, as do all such clocks, a small chimney at the top).
The dial depicts Mary Magdalene, who holds a book with what looks like a skull resting on it (memento mori themes were frequently associated with clocks; in fact memento mori paintings often show clocks and watches along with skulls). She’s looking at a crucifix located to the upper left, above the wandering hours display. I’ve read that the Campani brothers used two Roman painters of the period most frequently for decorating these clocks: Carlo Maratta, and Filippo Lauri and although the maker of this clock, and the artist, are both unknown, the Magdalene looks to me somewhat more like Carlo Maratta’s work.
The movement is a classic early pillar-and-plate pendulum construction – the first pendulum clock had only been invented by Huygens in 1657 (although there may be some question about that, as you’ll see in a moment). As with almost all early pendulum clocks this one has a verge escapement, arranged with the teeth of the crown wheel pointing downwards (if you’re interested in the action of the verge escapement, which is the first clock escapement known, there’s a reasonably good animation here). The pendulum clock as invented by Huygens had a very wide swing and the clock you see here was made when it was starting to become widely appreciated by clockmakers that a pendulum is only isochronous when it swings through a fairly small arc (one or two degrees at most being ideal). This escapement seems to have been optimized for a smaller arc for the pendulum; the clock was working but not running when I saw it but Felix Baumgartner set the pendulum in motion for me, and the swing was through a fairly small arc for a verge escapement.
The plates are held together with pins, rather than screws, which didn’t become really common until screw-cutting lathes started to become more widely used, in the mid-to-late 18th century.
Whomever is responsible for the decoration, it seems very probably that it was not the Campani brothers who made the movement. For one thing, the Campani brothers used the only escapement other than the verge that I’ve ever heard of this early in clockmaking. The Campani wandering hours clocks used a very weird “silent” escapement, in which the circular motion of the going train is turned into the reciprocating motion of the pendulum by a crank, attached to what looks like some sort of flywheel. As far as I can tell this was an independent invention of the Campanis and fell into disuse. Pope Alexander VII wanted a noiseless clock and I suppose he found the clack-clack of the verge distracting. I’d never heard of this escapement before doing research on this clock, but there’s a video of it in action on the website of a clock restorer who actually worked on one. It’s definitely one of the odder escapements I’ve ever seen; in The Study Of Time II: Proceedings Of The Second Conference Of The International Society For The Study Of Time, Lake Yamanaka, Japan (of all places) we can read:
“The Campani brothers were clearly excellent workmen … Matteo Campani, in 1655, in a well documented story, stated that Pope Alexander VII had asked him to apply the pendulum to clocks and that he wanted a silent clock, so that he could sleep at night without interruption.” The author goes on to opine that while conventional wisdom gives the credit to Huygens for designing the first pendulum clock, it seems clear that others were at the very least barking at his heels, and the Campani silent escapement may have preceded Huygens’ design, which I suppose would be a rather inflammatory statement in antiquarian horological circles, but it might actually be true.
On the other side of the office from the Sandoz “Equatorial Time” clock, are three clocks along one wall; all three are wonderful mechanisms but two of the three seem especially notable.
In the center is a clock by the famous French chronometer maker, Ferdinand Berthoud (whose name is alive again in watches produced by the Chopard Group). The clock was made around 1770, and the case is by Balthazar Lietaud, who is as famous in cabinet-making circles, as Berthoud is in horological circles.
The case is quite beautiful, if slightly more subdued than one on a Berthoud astronomical regulator that’s in the Metropolitan Museum Of Art. This clock shows both mean solar time, and true solar time (that is, solar time according to the changing length of a true solar day throughout the year, as expressed by the Equation Of Time) via two golden hour hands; the true solar time hand has a sun on it, logically enough. The clock has a perpetual calendar as well, and the pendulum is a so-called “gridiron” type, which uses alternating brass and steel rods (which have different coefficients of thermal expansion) to ensure the length of the pendulum doesn’t change with temperature. This would have been even more important in the draughty and poorly heated homes of the 18th century than today and as we’ll see with the next clock (and as we saw with the Sandoz “Equatorial Time” clock) it’s something of a theme in any pendulum clock with serious pretensions as a precision timekeeper.
One of the most interesting features of the clock is that its striking mechanism is driven, not by the mean solar time hour hand, but by the true solar time hand, which means when the clock strikes the hours and quarters, you’re hearing the time as you would if a sundial could chime the time – a lovely and rather poetic complication, and one which someone ought to see if they can reproduce in a wristwatch.
The last of the four clocks is perhaps one of the most interesting, and certainly one of the highest-performance, mechanical clocks ever made. It is an ultra-high precision pendulum clock, made by Riefler: a Reifler Type E, to be specific. This particular clock was made in 1955, when it was just starting to be clear that quartz clocks and atomic clocks were inevitably going to eat the pendulum’s lunch (the first atomic clock was made in 1949 and the first quartz clock goes all the way back to 1927, when Bell Labs produced one).
The Riefler Type E uses an escapement design by the company’s founder, Sigismund Riefler, in 1889, and it has a very interesting double escape wheel design, with cylindrical sapphire pallets. The pendulum rod is made of Invar (probably the clock would have been kept in a temperature controlled room but you take your millisecond advantages in rate where you can with this sort of thing). Impulse is given by the escapement to the pendulum suspension, rather than the pendulum itself. The suspension pivots on two hardened steel knife edges that sit on agate plates, and energy is transmitted to the pendulum by two steel blade springs; potential energy is stored in the springs by the escapement and released into the pendulum as it swings. The whole thing is remarkably efficient – the operating angle of the suspension is only 1.0º while the arc of the pendulum is 3.0º.
The whole design of clocks like the Riefler Type E, and related ultra-high precision clocks (other famous names are Shortt-Synchronome and Fedchenko) is based on the relentless pursuit of a single goal: creating an oscillator that swings with minimum external interference. The escapement in a Riefler clock is one of the few ever invented that does not directly interact mechanically with the oscillator; the pendulum is “read” optically, and the time transmitted to a slave clock; the cylinder enclosing the clock has most of the air evacuated, so that not only is barometric pressure constant, you also get as little energy loss as possible due to air friction. A pendulum swinging completely freely in a vacuum, with a constant amplitude, in unvarying gravity, should be a perfect timekeeper and this clock and its ilk were as close as mechanical ingenuity ever came to this goal. Such clocks, when properly installed, were accurate to within mere milliseconds per day and the Type E Riefler clocks were accurate to about one second every four years. If you’re interested in precision mechanical horology, this is, quite literally, as good as it gets (with the caveat that some of the Shortt-Synchronome and Fedchenko clocks could possibly do slightly better; the US National Archives has a Shortt-Synchronome clock that was tested in 1984 and found to have such a stable rate, that it would vary by no more than one second every twelve years).
It’s really wonderful to see these four clocks together, especially as you would not be likely to see any four such very different clocks – each a fascinating window into a particular approach to horology – all together in any one place other than a very comprehensive private collection, or in a museum with a very broad approach to horological acquisitions. You always find fascinating new bits of information when researching a story (that’s part of what makes it fun to write about watches and clocks, year after year) and I certainly wasn’t aware of the quite weird “silent escapement” of the Campani brothers before (and certainly not that it may have preceded Huygens’ invention). One last interesting note, is that Riefler apparently tried to apply a similar principle to pocket watches. The watch is mentioned in It’s About Time, by Paul Chamberlain, which was published in 1941. Chamberlain writes:
“In London, at the house of Charles Frodsham And Company, I found a watch of whose history they knew nothing. I secured it as having a very curious escapement and some years later, in going through the files of the Patent Office, found that it was patented December 30, 1890, by Sigismund Riefler of Munich, Germany. The movement undoubtedly was made in Switzerland but bears no number or name … I regret to say it has disappeared from my collection in some mysterious way. The balance receives the impulse entirely through the hairspring, which has its outer end pinned to the anchor piece … this is, I believe, the nearest thing to a free balance that has been proposed and executed.”
“Disappeared in some mysterious way,” has a fine, tantalizing ring to it – as well as stimulating frustration at the loss of information. It reminds me a little of the famous note the mathematician Pierre de Fermat left, in 1637, about the famous proof that bears his name, in the margin of Diophantus’ Arithmetica, which reads, “It is impossible to separate a cube into two cubes, or a fourth power into two fourth powers, or in general, any power higher than the second, into two like powers. I have discovered a truly marvelous proof of this, which this margin is too narrow to contain.”
Thanks to Urwerk for a look around their offices; you can visit them online right here.