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THE TRILOGY OF TIME
ASTROLABIUM - PLANETARIUM - TELLURIUM
by Marcus Hanke
HOW IT ALL BEGAN …
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In 1983 Rolf Schnyder bought the watch manufacturing company Ulysse
Nardin, which at that time was in immediate danger of bankruptcy. Ulysse
Nardin had a tradition of watch making since 1846 and was famous for its
high-quality chronometers not only built for private use, but also as
navigational instruments used by several navies. During the Seventies the
company became one of the many victims of the quick advance in watch
technology and production. Millions of cheaply produced, accurate quartz
watches flooded the market. This left the traditional mechanical watch,
which was manufactured in a long and time consuming process with a lot
of work done by hand, barely a chance to survive.
Nevertheless, Rolf Schnyder was convinced that the production of highclass mechanical timepieces still had a future. He also knew, that his newly
acquired company would need something really spectacular to reintroduce
its name into the exclusive league of the world’s best watch manufacturers.
During the search for this specialty, Rolf Schnyder visited the workshop of
a well-known watchmaker in Lucerne, Switzerland: Jörg Spöring. There,
he noticed an extraordinary wall clock featuring an astronomical dial, a socalled astrolabe. Upon asking, he learned from the master that his
apprentice, a certain Ludwig Oechslin, had constructed this clock. When
Mr. Schnyder finally met this apprentice, he immediately asked him if it
would be possible to create an astrolabe as small as a wristwatch. “Who
would be interested in buying it?” was Oechslin’s laconic answer.
This was the start of not only a steady friendship, but also of an
extraordinary co-operation. One result of it is presented in this book.
The Trilogy of Time
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The Trilogy of Time is also available as a limited set
SOME NOTES ABOUT THE HISTORY OF ASTRONOMY
What Does Astronomy Have to Do With Measuring Time?
In fact, our common measuring of time is nothing more than the
observation of basic astronomical events. What we call a ‘day’ is the time
span during which the Earth rotates once around its axis. Very early
already, mankind divided this span into shorter intervals, which made it
possible to keep record of the time elapsed within a day. The time shown
by our timepieces, be they worn on our wrists or hanging on the walls of
our homes, is always the representation of a specific moment during that
rotation of the Earth.
Since all watches are only a simple product of astronomy, it was logical
that the two functions – observation of astronomical events and the
measuring of certain time intervals – were combined into a single device.
In the beginning these devices hardly could be identified as ‘clocks’:
megalithic arrangements like those at Stonehenge in England and Carnac in
France, or Egyptian and Mayan temples. All of these artifacts were erected
for astronomical observations and calculations as well as being a place to
celebrate.
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The megalithic alignments of Carnac in Brittany served as religious site as well
as astronomical observatory.
The connection of astronomy, time and religion always was a very tight
one. The first people noticed that the Sun rises and disappears in more or
less regular intervals, that the Moon changes its face also regularly, and
that the stars seemingly kept their positions eternally. Therefore, those
celestial bodies became symbols for divine activities, which determined all
life on Earth. People came to the belief that Sun, Moon and stars even were
gods themselves, who needed to be worshipped. It consequently became
increasingly important to dedicate rituals, held at specific times, to the
gods. The architectural framework for the rituals became an instrument to
determine the important moments by means of optical signs. Only on one
or two days in a year, for example, (mostly the equinoxes) would the
sunrays reach a specially marked stone or spot. To maintain the gods’
favour it was indispensable to celebrate the rituals at the exact time, which
put the power of time into the hands of priests, who kept it for thousands of
years. Until today, the Christian holiday of Easter Sunday is determined by
astronomy. It is the first Sunday after the first full moon in spring.
Not only religious celebrations were held, following the accurate
observation of astronomical cycles, but also daily life was influenced by
these events. In ancient Egypt, it was noticed that the annual flooding of the
Nile started shortly after the bright star Sirius appeared in the sky for the
first time of the year (July 20th). This event determined the whole cycle of
sowing and harvesting and therefore, the Egyptian year started with the
appearance of Sirius.
After the multitude of gods assigned to the celestial bodies were replaced
with the belief in the one God, astronomical timepieces not only kept their
importance to calculate the correct times for ceremonies, but they gained an
additional didactic function. The observation of Sun, Moon and the planets
brought forward the insight, that their movements followed certain rules,
which themselves could only be the result of God’s planning and his
creation of the universe.
The huge astronomic clocks built in the Middle Ages and located in the
churches had the purpose of demonstrating to all spectators the magnificent
apparatus of the universe in which the Earth and man were placed in the
centre with the universe rotating around just as it was planned and executed
by the will of God. Therefore, the study of the celestial bodies, and the
exposition of astronomical clocks were a means to discover mankind’s
place in the universal order of things. They were instruments of philosophy
and religion, and even instruments of indoctrination.
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The huge astronomic clock in the cathedral of Strasbourg, France, was built in
1572–74.
Given this importance, it is not astonishing that the clerical monopoly of
time was soon challenged by the cities: During the 15 th and 16th centuries,
these had gained massive economic strength, and were eager to
demonstrate their independence from the church. While the old church
towers were a natural place to locate public clock displays, the magistrates
of wealthy towns quickly erected their own clock towers. Huge astronomic
clocks, such as the magnificent clocks in Padua (1434), Prague (1486), or
Berne (1530) were placed in either the townhalls, or in dedicated clocktowers, and proved to the public, that the interpretation of the universe was
not an entirely spiritual issue, left at the discretion of priests.
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The astronomic clock at the town hall of Prague, Czech Republic (1486)
Views of the World
When we observe the Sun’s path in relation to the stellar sky during a
year, it seems that the Sun rotates around the Earth, which is positioned in
the centre of the universe. This conclusion was made very early and found
its way into the old texts about the creation of the world. It was
scientifically explained mainly by the Egyptian mathematician and
astronomer Ptolemy during the 2nd century AD.
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The geocentric view of the solar system as Ptolemy defined it.
His geocentric system of the universe was adopted by the Catholic
Church and fiercely defended, even when scientific proof, that the Sun is
the centre, around which the Earth is rotating, was brought forward by
Nicolaus Copernicus in his book “De revolutionibus”, published in 1543.
Consequently, Copernicus and other defenders of his heliocentric system
ran into serious trouble with the Church. Galileo Galilei had to publicly
retract his support of the Copernican theory. Giordano Bruno was even
burnt on the stake by the Inquisition. Too far away was the new theory
from the traditional dogma about the Earth’s position in the known
universe. It seemed blasphemy to consider that God’s final and finest
creation, mankind, was not the centre of the world.
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The heliocentric or Copernican system.
Even when the heliocentric model finally was adopted, there were still
too many apparent inconsistencies and contradictions. The movement of
certain planets just did not follow the predictions, which were based on the
assumption that all celestial bodies moved in perfect circles. The
impression, that the universe was a gigantic automaton created by God, and
followed strict divine laws, prevailed. Moreover, as a special privilege from
God, man was enabled to use the same laws to recreate the universe in a
small scale as astronomic automatons in mechanical clocks.
It was Johannes Kepler, who finally delivered a serious blow against this
conception, when he proved that the planets moved along ellipses rather
than perfect circles. Sir Isaac Newton, with his gravitational laws,
demonstrated that so many different gravitational influences have an effect
on the planets’ movements, and that it is merely impossible to predict them
by means of strict and eternally valid formulas. Suddenly, it became
meaningless to reproduce the universal movements by means of
automatons, and the importance of the mechanical astronomical clocks as a
means of scientific, as well religious demonstration and education quickly
vanished.
CELESTIAL MECHANICS 101
Sun and Earth
The Rotation of the Earth
The Earth rotates around its own axis, causing the impression that the
Sun rises in the morning, passes its zenith at noon and sets in the evening
which is followed by a period of darkness, the night. This complete cycle is
one day, the basic time interval which can be defined by astronomic events.
In ancient times, the definition of the day had already been established as
the period between two zeniths of the Sun. By means of a simple stick in
the Earth, it was easy to determine that the Sun had reached its highest
point, when the shadow cast by the stick had its shortest length. However,
different cultures placed the beginning of a new day on different times, be
it the sunrise, the sunset or the noon. In the Roman Empire, the day
changed at midnight, which was a difficult issue, since no astronomical
event helped to determine this exact time.
The possibility to count days alone was not enough though, and a more
detailed subdivision was needed. This was achieved by dividing daylight
and night into twelve hours each, totalling twenty-four hours per complete
day. The twelve hour interval was already introduced in ancient times,
since the number twelve was a sacred number in nearly every old culture.
In Rome, the twelve daylight hours started at sunrise, the twelve nighttime
hours at sunset. The apparent problem with this subdivision is that the
Earth’s rotation axis is not at a right angle to its orbit around the Sun, but it
is slanted some 23 degrees. This angle is responsible for the change of the
seasons and the different lengths of light and dark periods during the year.
Therefore, the old method to measure the daytime, the so-called ‘apparent
solar time’, accepted different lengths of the hours. During winter, the
twelve night-time hours were much longer than the twelve daytime hours,
and vice versa during summer. Consequently, night and day hours varied in
their lengths, between 75 and 44 minutes. Only at the two equinoxes did
they last equally long, 60 minutes. It is clear that this system of measuring
time implies differences as soon as the geographical location is changed.
Due to the Earth’s rotation, places in the East experience sunrise and sunset
earlier than those in the West, resulting in a considerable difference at
larger distances. Since the average circle of social relations at that time was
very small, caused by the lack of long range communication assets and fast
means of transportation (around 1500, a journey from Venice to Lissabon
lasted about 46 days!), this difference was hardly noticeable. The system of
using the apparent solar time was convenient to use and easy to understand
for all people, who normally did not possess clocks, but were well aware of
sunrise and sunset as daytime constants.
The introduction of reliable mechanical clocks during the late 15th
century made these flexible hour lengths problematic, since the hours they
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One complete rotation of the Earth needs 23 hours and 56 minutes. Since
the Earth in the meantime has moved along its path around the Sun, its
angle of illumination has changed too, so the time span between noon A
and noon B is four minutes longer.
measured were all equally long. For that reason, the ‘mean solar time’ was
introduced, then designated ‘Italian hours’, after the region of their first
general use. This way of time measurement was independent from sunrise
and sunset, and is still used today. So the clocks first had to ‘invent’ the
regular hours before they could display them. For the people this was a
drastic change and made necessary the use of tables and sophisticated
instruments (astrolabes for example) to translate the hours shown in mean
solar time into the traditional apparent solar time.
Nevertheless, the definition of a day being the time between two noons is
still problematic, since it does not reflect the true rotational period of the
Earth.
If a certain point on Earth’s surface is marked, and the time span needed
for one complete 360 degrees-rotation of this point is measured, it is about
four minutes shorter than twenty-four hours. However, since the Earth
itself has travelled a certain distance on its orbit around the Sun during the
24-hour-period, it has to rotate a bit more than 360 degrees until the same
point has noon again. The time needed for a true 360 degree rotation of the
Earth is called a “stellar day”.
The Movement of the Earth Around the Sun
By observing the stars which the Earth seems to pass once a year, its
path around the Sun can be easily traced.
However, since the observations of our solar system are not made from a
virtual fixed point somewhere far above the system, we cannot recognize
the Earth’s movement itself. Our observing location is positioned on the
Earth, which for us, of course, seems to stand still. From our viewpoint, it
is the Sun that apparently is moving through the sky. This is the reason why
the theory of the geocentric universe seemed so logical at its time.
It is easy to understand the principle, if one imagines a ride on those
merry-go-rounds which can be found on children’s playgrounds. As long as
the spectator is standing aside and looks at the turning disc, he realizes that
the children on the disc are rotating around its central axis. But if he
himself steps onto the disc and concentrates on the apparent position of the
rotation axis relative to the surroundings of the merry-go-round, he can
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While the Earth rotates around the Sun, the view of the sky from the Earth (red
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arrow) is
constantly changing.
Seen from the Earth, the rotation around the Sun is perceived the other way
round – as if the Sun moves around the Earth; the plane of the rotation is the
ecliptic, while the background of the stars is designated the celestial sphere,
which has the Earth in its centre.
come to the conclusion that the axis is rotating around his own position.
The plane described by the Earth’s rotation around the Sun is called the
ecliptic. With the exception of Pluto, all other planets in the solar system
also are moving within only a few degrees of the ecliptic. From the Earth’s
viewpoint, the Sun seems to travel around the Earth on the ecliptic, which
itself meets the illusional sphere of stars behind the Sun. Of course we
know very well, that the stars we can see, are suns or even galaxies with
different distances to our solar system. For observation purposes, though,
one has to think of the distant stars as being ‘glued’ onto a huge sphere,
which is the outer limit of our little imagined universe. The Sun’s journey
during the year can be measured by its position relative to several distinct
stellar constellations dispersed along the ecliptic – the well-known twelve
signs of the zodiac (again the sacred number twelve was chosen already in
ancient times). These signs of the zodiac are somehow like a canvas, on
which the progression of the year can be observed. The twelve signs
correspond to twelve months subdividing the year, although today, its
limits do not correspond exactly with the beginning and end of the months.
It is also possible to check all the other planets’ movements against the
zodiac in the ecliptic.
Unfortunately, the ecliptic is not identical with the equatorial line of the
Earth, since its rotational axis is not at a right angle with the ecliptic. If the
plane of the Earth’s equator is enlarged, until it meets the sphere of the
stars, you get a line angled at 23 degrees to the ecliptic, the celestial
equator.
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The celestial equator is the projection of the Earth’s equator, which is angled
about 23 degrees to the ecliptic, due to the inclination of the rotational axis.
Consequently, also the poles of the celestial sphere are inclined.
Now we have to combine both movements discussed, the rotation of the
Earth itself and its circle around the Sun, to realize that, due to that angled
axis, we cannot see the ecliptic the same way all the time. Earth is rotating
us into a different angle every day, therefore there are many stellar
constellations or objects we cannot observe permanently. Stars like Sirius
or Rigel seem to rise at a certain time of the year, and after a period of
observability, they disappear again. This seemingly complicated pattern of
movements could be used to the advantage, either to determine an exact
date or for navigational purposes.
But not only astronomical observations are influenced by the difference
between the ecliptic and the equator. Far more important for our daily life
is the effect of the changing amount of sunlight received by the different
parts of the Earth’s surface during a year. This results in the four different
seasons: spring, summer, autumn and winter. Due to the angle of Earth’s
rotational axis, the two hemispheres are differently illuminated. If there is
summer in the northern hemisphere, the North Pole is positioned in the
illuminated part of the Earth all the time, resulting in the polar summer,
with no nightfall for half a year. The daylight periods are longer than the
nights. At the same time, the South Pole is shrouded in darkness for half a
year. Then it is winter on the southern hemisphere, and there the nights are
longer than the days. Only twice a year, on March 21st and September 23rd,
night and day are equally long on all the Earth. These two dates, where the
lines of the ecliptic and the equator meet, are called the equinoxes and mark
the beginning of spring and autumn. Two other dates mark the beginning of
summer (June 21st) and winter (December 22nd). The former has the longest
daylight period on the northern hemisphere. Thereafter, the daylight times
decrease, while the latter has the longest night, with the days becoming
longer again.
The rotation cycles of the Earth around the Sun impose a serious
problem to our calendars. Unfortunately, the Earth does not need 365 full
rotations (days) to complete one cycle, but nearly a quarter of a day longer
than that. Therefore, every year includes an unfinished fraction of a day,
which after four years is summed up to a bit less than one day. Since our
calendar systems are based on complete days, they have to correct the
mistake by the insertion of an additional day (February 29th) in the leap
years. This manipulation again is slightly larger than necessary, therefore
some other corrective interventions have to be made in the calendar every
hundred, and again every four hundred years. But due to the gravitational
effects of all the planetary masses in the solar system, the Earth is
accelerating a little, so that the years become shorter, albeit at a minimal
rate.
Earth and Moon
The Phases of the Moon
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The lunar phases are the result of the changing illumination by the Sun,
which has its reason in the rotation of the Moon around the Earth.
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An 18th century illustration shows the various phases of the Moon.
On its path, the Moon has a position between the Sun and the Earth once,
so we only see its shadowed side, which of course results in seeing nothing
of the Moon at all. This phase is the new moon. After having orbited to the
opposite side of the Earth, the Moon is fully back-lit by the Sun when
observed from the Earth; this is full moon. Between these two phases, the
Moon is waxing or waning.
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The conjunction of Earth and its moon are shown in this picture from the Galileo
orbiter in 1992.
The period between two same phases is 29 days, 12 hours, 44 minutes
and 2.9 seconds, which is also called the synodic month. Again, similar to
the definition of a day, based on the rotation of the Earth, the lunar phases
do not accurately correspond with the real rotation of the Moon.
To complete a 360 degree circle around the Earth, the Moon only needs
27 days, 7 hours, 43 minutes and 11.5 seconds (sidereal month), but in the
meantime, the whole Earth–Moon system itself has moved on its path
around the Sun, and the angle of illumination has changed too.
Due to gravitational effects, the mean distance between Earth and Moon
is increasing, so the time for a rotation around the Earth also becomes
slightly longer. This is another proof against the old perception of the
universe being a rule-dictated machine.
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Due to the changed angle of illumination, the time span between two new
moons (synodic month) is longer than the period of one complete rotation of the
Moon around the Earth (sidereal month).
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The different layers of the Sun’s corona, as seen during the
total eclipse on August 11th, 1999
Solar and Lunar Eclipses
When the Moon is positioned between the Sun and the Earth, it casts a
shadow onto the latter, blocking the sunrays from the Earth’s surface and
causing a solar eclipse. Since the Moon is not large, its shadow is limited
to a restricted zone. This core shadow, called umbra, has a diameter not
larger than 200 to 300 kilometres. Observed from outside the umbra, the
eclipse is only a partial one, since the Moon’s disc seen from the Earth is
just large enough to barely cover the Sun. But not every eclipse of the Sun
is total, in fact only a small minority are. The others are either partial or
ring shaped. The latter is the case when the distance of the Moon from the
Earth is not small enough for the moon disc’s shadow to cover the Sun
entirely.
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Total eclipses of the sun, as visible on the Earth 1999 – 2020
Anybody who has the rare opportunity to see a total eclipse will never
forget the experience. Within minutes, the Sun disappears and it becomes
as dark as a normal moonlit night. Temperature drops within seconds and
nature goes to sleep. Since the Moon blocks the bright disc of the Sun, one
can see the corona – a belt of hot gas which is normally outshined by the
Sun.
Another type of eclipse happens if the Earth is blocking the sunlight
from the Moon passing behind it. The shadow cast by the Earth is
darkening the full moon and, since the Earth’s shadow is so much larger
than its satellite, the lunar eclipse can be observed from everywhere on the
night side of the Earth. Due to the refraction of the sunlight in Earth’s
upper atmosphere, the Moon appears in a fiery red shortly before it
disappears in the earth shadow. The same fascinating view is experienced
again when the Moon leaves the shadow.
Now one might ask, why the Moon’s path around the Earth does not
cause a solar and a lunar eclipse every month, since at every full moon the
Earth is located between Sun and Moon, and at every new moon the Moon
is between Earth and Sun. If the orbit of the Moon would lie on the same
plane as the ecliptic, this would indeed be the case. However, the lunar
orbit is angled approximately 5 degrees to the ecliptic, so normally the
Moon passes too far above or beneath the Sun or the Earth's shadow to
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As long as the Moon’s orbit passes the ecliptic on nodes similar to nodes A, the
Moon will stand clear of the Earth’s shadow at full moon, and the Moon’s
shadow will miss the Earth at new moon. But when the nodes move to position
B, the Moon is very near the ecliptic, and at new moon its shadow is cast on
Earth’s surface – a solar eclipse occurs. At full moon however, the Moon enters
the shadow of the Earth, resulting in a lunar eclipse.
cause an eclipse. The lunar orbit is meeting the ecliptic in two nodes, which
(to complicate things even further) themselves are slowly moving. Only if
the Moon is near one of the two nodes, an can eclipse take place – if the
Sun–Earth–Moon constellation is correct, of course.
CREATING MASTERPIECES
The Creator: Ludwig Oechslin
Born in 1952 in Italy, Ludwig Oechslin visited schools in the Germanspeaking part of Switzerland, before he started his academic career in 1972.
Then he began his classical studies (a combination of archaeology, ancient
history, Greek and Latin) as well as history, history of arts and philosophy
at the university of Basel, where he graduated in 1976.
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Ludwig Oechslin in his private atelier
If one takes into account his later career and fame as one of the world’s
leading personalities in watch making, it is quite ironic that Oechslin never
had worn a watch before, since his day was dictated by the large school
clocks. However, when attending classes at university, his schedule became
more densely packed. But above all, it had to be individually organized,
therefore the purchase of a watch became indispensable. While visiting a
watch shop, he took a special pocket watch into his hands – a repeater. The
complexity of the movement, and especially the chiming mechanism,
fascinated him at once. Unfortunately, he could not afford the watch, but
for a man like him, this was not a reason to give up. “Then I’ll build my
own!“ was the logical conclusion he drew from his encounter with the
watch.
But before, his growing dissatisfaction with the ivory-tower-theory
taught at the university urged him to look for a profession in which he
could use his own hands practically, as well be creative. Now it was clear
for him that he wanted to become a watchmaker. At the age of 24, it was
not easy to find a master willing to accept him for apprenticeship. Finally
Jörg Spöring, a well-known watchmaker and restorer of antique clocks,
took Ludwig Oechslin under his wings.
After a short time, Oechslin had his first intense contact with an old
astronomic clock. He was sent to the Vatican to repair and restore the
Farnesian Clock, an astronomical clock more than 250 years old and of
unequalled complexity. Not only did he repair the timepiece, he also
remanufactured a large share of the parts and studied the clock’s functions,
what kept him busy for years. The results intrigued him, and he wanted to
know more about the people who created such clocks, their thoughts, and
the scientific implications behind them. Upon his return from Rome in
1982, he started additional studies in the disciplines astronomy, philosophy,
and history of science (theoretical physics) at the university of Bern,
graduating as a Doctor in 1983, after having published his dissertation
about the clock as a cosmological model. As a side note it should be said
that the publication of Dr. Oechslin’s doctoral thesis had to be postponed,
because the data therein could possibly have interfered with the patenting
procedure of the Astrolabium.
Within the next dozen years, Oechslin became an internationally
appraised expert on astronomical timepieces from the 16 th to the 18th
century, travelling around Europe to restore and study old clocks. Besides
that, he continued of course with his training as a watchmaker, receiving
his diploma in 1984 and finally became a master watchmaker in 1993. Both
his practical training as a watchmaker, and his academic career went hand
in hand. The latter reached a height when he got his license to teach at
universities in 1995 (a longish procedure traditional with Central European
universities, the “habilitation”, necessitates the publishing of a voluminous
scholarly work as well as giving several lectures before the “venia
legendi”, the license to teach, is accorded). He subsequently joined the
faculty of the Swiss Federal Institute of Technology in Zurich – one of the
best-known technical universities in the world, holding lectures about
astronomy, cultural history and cosmology.
Ludwig Oechslin’s scientific excellence, and his fame as one of world’s
most innovative watchmakers, were honoured, when in 2001, the city
council of La Chaux-de-Fonds offered him the position as the curatordirector of the International Watch Museum, the most complete and
renown horological collection in the world.
Ludwig Oechslin and the Trilogy of Time
Soon after he was commissioned with the development of the
Astrolabium, Oechslin completed his prototype in 1983. Two years later,
the watch was presented to the public during the Basel watch fair, and
astonished both watch lovers and watchmakers. Never before had an
astronomic mechanism of similar complexity been integrated into a small
wristwatch. The Astrolabium was immediately adopted into the famous
Guinness Book of Records, as well as integrated into the permanent
collections of several museums worldwide. However, this success was only
the beginning and assured Schnyder and Oechslin to continue building
Ulysse Nardin’s reputation as one of the best watch manufacturing
companies in the world. From the very beginning already, Oechslin had
planned to embed the Astrolabium into a system of astronomical watches,
in order to present them together as a small cosmological model. Only three
years later, in 1988, Ulysse Nardin presented the next masterpiece
developed by him: the Planetarium. And again the public looked with awe
at the new marvel, which integrated the planets’ movements into a tiny
model, small enough to be worn on the wrist. This watch, too, immediately
found its way into the Guinness Book of Records, and once again collectors
and museums were quick to add it to their inventory.
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Ludwig Oechslin in his atelier at Ulysse Nardin
But the final coup had yet to follow. In 1992 the piece completing the
Trilogy of Time was unveiled, the Tellurium, showing a depiction of the
Earth–Moon–Sun system together with the changing illumination of the
Earth’s globe by the Sun. The “Trilogy of Time” as a whole was the
impressive demonstration that Ulysse Nardin belonged to the most
innovative watch manufactories in the world, less than ten years after Rolf
Schnyder had saved it from imminent bankruptcy. Moreover, it proved
what the correct mixture of idealism, capability and economic commitment
can accomplish. Ulysse Nardin had found its path of individualism, and
raised its position above and away from anonymous mass products.
[Picture: L. Oechslin working on a watch (from the brochure “The Master
Timekeepers”, page 6)]
After the completion of the astronomic Trilogy Ludwig Oechslin
directed his attention to other, this time more “earthly”, projects. He
designed the first simple-to-use and reliable mechanism for adjusting a
watch to different time zones, even backwards over the date line. He also
created the first mechanical perpetual calendar, which can be adjusted
forward as well as backward simply by means of a single crown, and in
1999 even combined it with an additional GMT-mechanism.
[Picture of Perpetual GMT from the catalogue]
Only a few years later, in 2001, Ulysse Nardin stunned the horological
world with Ludwig’s idea of a ‘simple’ watch: The astonishing Freak, a
seven-days-caroussel tourbillon, in which the two movement bridges
themselves serve as ‘hands’ to display the time. Heart of the Freak is the
new dual direct escapement, which makes use of wheels made from
silicone.
[Picture of Freak from the catalogue]
2003 brought another apex of Ludwig Oechslin’s genius, when Ulysse
Nardin presented the Sonata, world’s first mechanical alarm watch, which
enables its wearer to set the alarm over 24 hours in advance, and see the
remaining time until the alarm gets off on a unique count-down display.
This automatically takes into account changes of the current time zone, via
the integrated GMT mechanism. The development of this watch needed
seven years in total.
<Insert picture \trilogy\pictures\sonata.tif>
Now let us recall that day when Ludwig Oechslin found a repeater watch
and decided to become a watchmaker to build one himself. He never built
it. As soon as he was able enough to construct and assemble such a watch,
he also realized that it was nothing new. Countless watchmakers before
him had built repeaters and brought them to perfection. However, what
continues to intrigue him is the challenge of making something completely
new, something never seen before in a watch, and to this he dedicates his
creative energy enriching the horological world with amazing masterpieces.
Understanding the Philosophy Behind the Trilogy of Time
The fact, that Ludwig Oechslin chose the three astronomical mechanisms
astrolabe, planetarium and tellurium for the Trilogy of Time was not
accidental, since these types of automatons present an interpretation of the
world and the universe from a scientific point of view. More than that, they
also express a spiritual model of the cosmos and of our little world in it.
The important historical role of astronomical clocks in religion and even
policy has been pointed out in the previous chapters. Additionally, these
automatons served the purpose to intensify the people’s contact with their
astronomical environment. During all time, people’s days were dictated by
astronomy, be it the course of the Sun in the sky, be it the Moon and its
phases, or the seasons which resulted from the Earth’s path around the Sun.
Astronomical clocks demonstrated to their spectators, how God had made
these things to work, and why everything is happening according to his
will. Besides the religious aspects, all the observations of the sky and the
reconstruction of its system were only made in order to better understand
Earth and its place therein. This means that the primary motivation behind
the studies was the Earth itself.
Today we seemingly have lost the contact to our own planet. On the one
hand we are chasing for seconds or even for fractions of them, sitting in
artificially lighted offices and halls. Electric lighting has driven back the
night’s darkness. If you want to study the sky at night thoroughly, you have
to search for a place somewhere in the desert, because our habitations spill
too much light into our atmosphere. We have been decoupled from the
astronomical events which left their marks on our ancestors’ everyday life.
We leave home for work without respect if the Sun has already risen or not.
When it reaches its zenith at noon, we are sitting at tables in the light of
electric bulbs and the setting of the Sun does not leave any impression on
us, if we are not on a seaside beach during our holidays. The lunar phases
have lost their former importance on our lives too. Only the seasons are
somewhat still relevant for heating costs and the weather forecast.
On the other hand, we have learned so much about space and the planets
that we think of the Earth being not more than a tiny speck of dust
somewhere on the rim of our galaxy. With our attention focussed on
objects so far away, we often overlook the importance our own planet has
for us and our future.
By means of the Trilogy of Time, Ludwig Oechslin tries to increase our
sensitivity for the things happening in the sky, so that we become aware
again of our place and our responsibility for it. Seconds are not the relevant
scale here, and not even the date of the days, which are but an arbitrary
subdivision of a year. What count are the movements of the Sun, the Moon,
the planets, and of course the Earth, which is in the centre of all three
watches.
The three watches can be understood as milestones of a long voyage. It
starts from a point outside the solar system, from where the spectator can
see the Earth as well as most of the planets. This is the scenery of the
Planetarium. As he gets closer, the Earth’s globe fills his sight, together
with the Moon orbiting around it. He can observe the Earth’s rotation as
well as the seasonal change of its illumination, all of which is displayed on
the Tellurium. Finally, the traveller has arrived on Earth’s surface, directing
his view back to where he came from – the stars which wander over the
Astrolabium’s dial.
<Insert picture \trilogy\pictures\tuerler.tif>
The “Türler Clock – Model of Cosmos” is installed in Zurich, Paradeplatz
However, Oechslin’s model of the cosmos still was not complete. A final
and spectacular apex was to follow when he integrated all the Trilogy’s
information and much more into the large and impressive “Türler Clock –
The Model of Cosmos”, unveiled in 1995 and installed in Türler’s shop in
Zurich, Switzerland. His former master, Jörg Spöring, built this large
astronomical clock following Oechslin’s plans and calculations.
While all three watches of the Trilogy display the Earth as their crucial
point, be it as the observational base in the Astrolabium, as the fixed part of
the Planetarium, or the rotating centre of the Tellurium, the Türler clock
focusses on other, sometimes more traditional aspects of astronomical
automatons. Its planetarium shows all the solar system’s planets, even
Pluto, in their movements around the Sun. The Earth is but a part of that
eternal dance. The Tellurium, too, does not have the Earth in its centre, but
displays Earth and Moon moving around the central Sun. The most
impressive part of the clock, however, is a model of the Earth’s globe
embedded into a crystal sphere with golden stars on it, symbolizing the
celestial sphere. This sphere rotates incredibly slowly around the globe,
once in 25,794 years (a so-called platonic year).
Ludwig Oechslin’s vision of the cosmos, as expressed in the timepieces
of the Trilogy of Time, cannot be complete without the magnificent Türler
clock, one of the most complex clocks in the world. Unfortunately, even
Oechslin’s genius is not able to stuff the great globe with its celestial
sphere into something as small as a wristwatch!
Technological Challenges
The realization of the Trilogy pieces in the first instance was faced with
big technological problems. By means of conventional watch making
technology it was believed impossible to manufacture mechanisms like
those introduced with Astrolabium, Planetarium and Tellurium. The key
was hidden in that old astronomical automaton studied and restored by
Oechslin in the Vatican: the Farnesian clock. When he took it apart,
Oechslin realized that most of its displays were driven by means of layered
epicyclic gear systems.
<Insert illustration \trilogy\graphics\epicycl-7.ai>
Rotation of epicyclic wheels
Epicyclic is a wheel mounted eccentrically on another wheel, moving
around this centre wheel while turning itself, too. Sounds complicated?
Well, it certainly is. Oechslin knew that there must be some mathematical
formulas behind that mechanism, but was unable to find any reference in
the old books. Therefore he faced the challenge and completely recreated
the analytical and mathematical model necessary to calculate the
positioning, dimensions and number of teeth for all the gear wheels. This
enabled him to remanufacture the damaged parts of the Farnesian clock.
Once he had developed the mathematics, he was able to transfer the
system into a small wristwatch – theoretically. However, here he
encountered new problems from the material side. A large astronomical
museum clock is very unlikely to be moved, let alone to be subjected to
heat, cold, shocks, and similar hazards. Therefore, the material stability or
its mass are not of extreme importance. A wristwatch, on the other hand is
accompanying its wearer nearly everywhere, and of course has to resist all
those smaller and larger hits, bumps and watering incidents, which
normally happen every day. The mechanisms employed in the Trilogy
watches are so delicately adjusted and calculated that any maladjustment
due to a shock could cause the watch’s astrological displays become
inaccurate. Main reason for concern was the large size of the rings and
discs used for the astronomical indications. Were they made from
conventional materials, such as brass or silver, they would have been too
heavy, with their mass inertia putting too much strain on the wheelwork, in
case of a sudden bump.
The problem’s solution was found in aerospace technology, where new
alloys, that were ultra light and highly resistant against shock or
temperature changes at the same time, had been developed. The watch parts
made from these alloys are so light, that they even float on water and still
are as tough as parts made from brass or steel.
[Picture: Month/zodiac ring (Brochure: “The Master Timekeepers”, page 9)]
Additionally, there are hundreds of tiny balls with a diameter as small as
0.5 millimetres, on which the astronomical gears are running. They had to
be found in a specialized industry, before they could be implemented into
the Astrolabium’s system. Finally, the whole system had reached an
unbelievable degree of accuracy. The calculation base of the Astrolabium’s
mechanism leads to an error of one day after 144,000 years! This is far
more accurate than the solar system itself because of gravitational
influences. The Earth, Moon and the other planets will have changed their
orbits and rotation times considerably in that time span.
The Planetarium’s unique multi-disc-based display also could be
mastered only with new ideas. There, the fixed location of the Earth helped,
since it was possible to locate all the gearing beneath its ring. And finally,
there is the Tellurium, which, while looking even simple when compared
with its two predecessors, confronted its creators with a constructional
problem especially difficult to solve: The thin flexible string, marking the
demarcation line between the illuminated and the dark side of the Earth,
has to be trained by a gear, ensuring that it always bends correctly during
the changing seasons of the year. At the same time, the wear on the gear
had to be kept on a minimum, so that the Tellurium works flawlessly for a
very long time. Finally, Ludwig Oechslin’s genius and the ingenuity of
Ulysse Nardin’s technicians overcame all problems, presenting unique
timepieces to the horological world.
But the Trilogy watches have not been made to be seen as mere pieces of
jewellery and kept locked away in a safe. On the contrary, they should be
used everyday, and they have been prepared to fulfil that task. The setting
and adjusting of the different indications has been simplified so much that
it is possible to execute all necessary changes by means of the crown only,
respectively by the crown and one additional pusher in the Tellurium. To
make possible that simplification, new ways to protect the delicate
mechanisms behind the dial had to be developed. Special friction clutch
systems prevent the gearing systems from being damaged when the quick
correction function is used to move the indications forward or even
backward.
The watches’ gold or platinum cases are watertight, and the hour and
minute hands are treated with luminous mass (with the exception of the
new limited set edition in platinum) so that the time is easily legible even
under adverse light conditions. After all, Ludwig Oechslin’s philosophy of
usability and simplicity influenced the Trilogy pieces’ design more than
just superficially, in spite of their apparent complexity as astronomical
timepieces.
Craftsmanship
Besides the technical side of the astronomical mechanisms, the Trilogy
pieces are also examples of the finest craftsmanship when it comes to
decoration: The gilt movements are finely engraved and chased by the most
able masters of this profession.
<Insert picture \trilogy\pictures\movement.tif>
The rotors of the self-winding mechanisms are painstakingly
skeletonized to show the anchor logo of Ulysse Nardin, while the loss of
mass is compensated by massive gold as rotor material.
[Picture: Mounting of Astrolabium rotor (from the brochure The Master
Timekeepers, page 9)]
The use of precious materials is continued on the other parts of the
Trilogy watches. A limited series of only 65 Planetaria even has its
planetary rings made from a meteorite which Admiral Peary brought back
from his polar expedition in 1897.
[Picture: Meteorite Planetarium from the book History in Time, page 77]
Enamel Cloisonné
Ulysse Nardin became famous not only for technical innovations, but
also for reviving old and seemingly forgotten arts, the most beautiful
example being the cloisonné enamelling. This fine enamel technique had its
greatest period from the 10th to the 12th century, especially in the Byzantine
Empire. In addition, China developed a rich culture of cloisonné.
[Picture: UN cloisonné dial - Jungle Repeater or San Marco]
Enamel is a comparatively soft glass, a compound of silica, red lead and
soda or potash. These materials melt together, resulting in a nearly
colourless glass with a slightly bluish tint. The agents responsible for the
bright and glowing colours are metallic oxides, which are introduced into
the molten glass. Brilliance of the enamel depends on the right combination
of all components and the steady temperature in the melting furnace. The
colours of the enamel are achieved mostly in a change of proportion of the
different components rather than by a change in the oxides’ quantity. The
heated enamel finally is allowed to solidify into cakes of about 10
centimetres diameter, which for use has to be powdered in a mortar.
[Picture: Powdering enamel, from the book History in Time, page 116]
In a series of washings, all floury particles are removed from the powder,
which then is applied as a wet paste to the metal base cleaned and prepared
by acids. The baking in the furnace afterwards is fusing the enamel with the
metal.
[Picture: Baking enamel dials, from the book History in Time, page 116]
While the ‘conventional’ enamelling already is a very difficult
procedure, making a work of art by means of cloisonné is even more
complicated, and consequently is mastered only by very few artists today.
In this technique, an extremely thin gold wire with a thickness of only
0.07 millimetres and a height of one millimetre, is bent by hand with two
pairs of pincers to follow the wanted contours. In the example of the
Tellurium’s Earth, these contours follow the continents and the major
islands, on a disc not more than two centimetres in diameter. The smaller
the motif, the more difficult it is to bend the wire into the right shape.
[Picture: Bending the cloisons, from the brochure Baked enamel and enamel
cloisonné – an old art rediscovered, page 4]
By means of vegetable glue the wires are glued to the dial, which then is
baked at 840 degrees Celsius, until the glue has solidified and the wires are
firmly attached to the dial.
[Picture: Gluing the wires to the dial, from the brochure Baked enamel and
enamel cloisonné – an old art rediscovered, page 5]
A decidedly non-high-tech instrument is used to apply the enamel paste
into the different cells: a goose quill, which experience has proven to be the
best tool for that delicate process.
[Picture: Filling the cells with enamel, from the book History in Time, page 119
(shows Mayflower dial)]
The wire cells prevent the colours from mergeing into one another,
which would make it impossible to recognize the continents afterwards.
However, this blurring effect can also be welcome. This is how the fine
variations of green, yellow and brown continental zones are accomplished
on the Tellurium dial.
Four to five layers of enamel are applied to the dial and each one is then
baked in the furnace. The multi-layering is necessary to obtain the glossy
and even glowing colour of the enamel after polishing. Additionally, the
uneven thickness of the differently coloured continents and oceans can be
levelled as well.
After this process, another piece of delicate handwork is necessary; the
reduction of the gold wires jutting out from the enamel surface. Extreme
care is indispensable when polishing the wires, until they are completely
flush with the enamel, and a final smoothening procedure brings out the
deep shine and glow of the enamel dial.
[Picture: Dial before and after polishing, from the brochure Tellurium, page 12]
Fifty-four processes, twelve baking operations, and more than fifty
working hours are needed to transform a drafted sketch on a small metal
disc into a uniquely designed work of art. This includes the exact
positioning of the gold wires, the application of the enamel colours to the
cells and the filing and final polishing. All of this work can be destroyed
within seconds by something as simple as a heating problem in the furnace.
The enamel dial makes the Tellurium even more unique. Since gold
wires cannot show the exact same contours every time, every Tellurium is
different from the other. The colours melt into one another and vary from
one dial to dial thus the owner of a Tellurium can be assured that nobody
else on the world wearing the same watch.
USING THE TRILOGY
The Astrolabium
<Insert picture \trilogy\pictures\astrolab.tif>
Already in ancient Greece, navigators used astrolabes to calculate time
and position by means of measuring the exact elevation angle of stars,
planets and the Sun over the horizon. The observed data could be
transferred to the astrolabe, which again presented the desired result on
several scales. For astronomers, the astrolabe served as a mobile star chart,
but it could also be used as a clock, a geographical tool, a surveillance
instrument or as means of converting time measurements. Because of such
features, the astrolabe can be regarded as a kind of rudimentary analogue
computer.
It became extremely popular in the Middle Ages, but was replaced by the
even more versatile sextant in its navigational field of use, and by portable
mechanical clocks that measured time. However, for very specific
astronomical tasks, astrolabes – albeit much more modern in appearance
than the classic ones – are still used today.
If one were to compare Ludwig Oechslin’s Astrolabium with its
medieval predecessors, there is one difference that might be noticed
immediately. The classic astrolabes were used “the other way round”,
which means, that a metal ruler (called alidade) was used to sight certain
objects in the sky, and then the alidade’s position was transferred onto
several scales found on the astrolabe’s back side. These scales then
displayed the current time together with other astronomical information.
However, the setting on the back also influenced the display on the
astrolabe’s front, where an open-pattern disc (the rete) with a “map” of
important stars rotated on the heavy base plate (the mater), engraved with a
network of lines representing celestial co-ordinates.
Therefore, this traditional astrolabe served two different purposes: to
observe and to display. Ulysse Nardin’s Astrolabium concentrates on the
latter aspect. It only displays astronomical information, without offering the
ability to actually observe celestial bodies. This is of course logical, since a
wristwatch is too small an object to serve as a solid base for optical
observations. And additionally, the main purpose of the observation – to
determine the correct time – has become needless, since an accurate and
reliable watch movement delivers the exact time, twenty-four hours a day.
In that respect, the Astrolabium watch is not new. Since the time when
reliable mechanical clock movements were available, astrolabe functions
have been coupled with them. These automatons should simplify the
complicated process of reproducing the movements of the Sun, the Moon
and the fixed stars. Big clocks with astrolabe dials, mostly installed in
public places, have been known since the 14th century, and it was one of
these clocks, the 17th century Farnesian clock, which delivered Ludwig
Oechslin the experience and knowledge needed to miniaturise the complex
mechanisms, until they fit into a wristwatch. This was the true innovation.
Never before had a universe with Sun, Moon and stars been packed into
such a small case.
Interpreting the Astrolabium
The core of every astrolabe, and therefore Ulysse Nardin’s Astrolabium,
too, is a planispheric projection of the stellar sky above the observer. The
main difficulty in understanding and interpreting this depiction, is that it is
very difficult to reduce a three-dimensional space to the two dimensions of
a watch dial. The same problem occurs, when the world’s geography is
represented on a two-dimensional map, and we are all familiar with the
somewhat distorted appearance the Earth has in a printed world map. In our
case, the Astrolabium’s dial, corresponding with the mater of old
astrolabes, is a projection of a semi-sphere that extends from the observer
to its centre. The visible horizon is a circle stretching around the observer,
and the celestial objects (stars and planets) seem to be fixed on a sphere
stretching upward from the horizon. Since the Earth is blocking the
observer’s sight downward, only the upper half of the sphere can be seen.
Once this concept is understood, the interpretation of data indicated by
the Astrolabium’s dial is easy. It is also clear, that each observer on the
Earth has an individual sphere stretching around him, and the location of
celestial objects in relation to this sphere depends on his position on the
Earth’s globe. For instance, if the observer stands on the North Pole, the
Polar Star would be directly above his head, but from the equator, the Polar
Star is observable at the horizon. Therefore, the Astrolabium can only be
used properly, if it is “calibrated” to the observer’s position on the globe.
As far as the latitudinal (north–south) position is concerned, this must be
done during the manufacturing process, since the gridlines printed on the
dial (or mater) change depending on whether the observer is located more
northwards or more southwards on the Earth.
<Insert illustration \trilogy\graphics\horizon-7.ai>
Every location on Earth has its own horizon, with its individual celestial sphere
stretching above it. While the Earth continues rotating, the angle of the ecliptic
towards the sphere of the visible sky changes constantly.
The longitudinal (east–west) position of the observer is important
because of the differences in time: Locations in the East experience the sun
rising before other locations more in the West. This difference can be taken
into account by moving the sun hand forward or backward (see in the
chapter: Setting the Astrolabium).
Reading the Legal/Normal Time
The hour and minute hands indicate the legal (or just ‘normal’) time,
which is valid at the user’s current location, according to the appropriate
time zone. Both are covered with luminous mass to make them visible at
night (except the limited series platinum Astrolabium). On the bezel there
are engraved Roman numerals, from I to XII, which in combination with
the aforementioned hands show the current time. During daylight saving
time (DST), the hour hand has to be advanced an hour.
<Insert picture \trilogy\pictures\as_time_new.tif>
In this example it is 10.10 legal time, but about 10.55 solar or local time.
Reading the Local/Solar Time
We know that any location in the East experiences sunrise or noon
earlier than a location in the West. This is the result of Earth’s rotation. We
also know that one complete rotation of 360 degrees needs a period of one
day (24 hours). Therefore, the rotation of only one-degree needs a 360th
fraction of one day to complete, this fraction being four minutes long.
Consequently, a place located only one degree further west from another
place, experiences sunrise and noon four minutes later than that previous
spot.
Today we are used to our system of time zones, and therefore
involuntarily think that all places in the same time zone must have noon at
the same time. But let us remember how this time zone system came into
being: As we have learned before, in earlier times every place had its own
time indicated by large sundials. When the shadow cast by the sundial’s rod
had its shortest length, it was noon. This tradition was kept, even after
mechanical clocks replaced the old sundials. In every day life, the
differences in time between the towns were not a serious problem, because
travelling was very slow, so practical consequences were negligible. But in
the 19th century, with the opening of the first transcontinental railway line
in the United States, rapid transportation became possible and common,
and suddenly the problem of time differences was acute: How could
anyone co-ordinate a railway timetable, when every single station had its
own time?
In 1884, a Canadian railway planner and engineer, Sir Sandford Fleming,
found the logical solution. He simply divided the Earth’s globe into twentyfour longitudinal zones (stretching from north to south), 15 degrees apart,
starting with the prime meridian at Greenwich, England (Greenwich Mean
Time, GMT). Within each zone there should be the same time. This system
is the base of our modern communication and transportation, but we should
not forget that it is a man-made, voluntary system, which does take into
account the factual rotation of the Earth only roughly. An example might
illustrate the problem:
Both, Budapest in Hungary and Brest in France, share the same time
zone (GMT +1), but their geographical locations are twenty-three degrees
apart. Since the standard for one time zone is 15 degrees, the two towns
should be in different time zones. However, the system is heavily
compromised by political and geographical considerations, so the rule of
the 15 degrees is ignored or bypassed very often. The Earth needs four
minutes to rotate one degree, therefore Budapest experiences sunrise, noon
and sunset more than one and a half hours earlier than Brest. It is clear that
any astronomical instrument, which indicates information like the time of
sunrise and sunset, must take into account this difference and cannot
simply base its calculations on the current legal or normal time.
Additionally, it must ignore further voluntary settings like daylight saving
time.
The current local or solar time is indicated by the sun hand, which makes
one complete turn every twenty-four hours. The time can be read from the
bezel again, but this time by using the Arabic numerals, which show
twenty-four hours, although for better clarity they have been omitted at the
locations of the roman numerals.
Calendar
<Insert picture \trilogy\pictures\as_date_new.tif>
The sun hand’s tip serves two purposes: On the calendar ring, it indicates the
current month, together with the Arabic numerals on the bezel, the current
local or solar time is shown.
The tip of the sun hand on the calendar ring indicates the current month.
This ring’s movement is based on the exact duration of the Earth’s orbit
around the Sun: 365 days, 5 hours, 48 minutes and 46 seconds. Since it
does not subdivide its indication into full days, it is also not necessary to
insert any leap days – the Astrolabium’s calendar is always correct.
The day of the week can be read from the window at six o’ clock, and
the current sign of the zodiac is indicated by the sun hand’s measure edge
on the ecliptic, onto which the zodiac signs are imprinted:





Aries (Ram)
March 21–April 19
Taurus (Bull)
April 20–May 20
Gemini (Twins)
Cancer (Crab)
Leo (Lion)
May 21– June 21
June 22–July 22
July 23–Aug. 22





Libra (Balance)
Sept. 23–Oct. 23
Scorpius (Scorpion)
Oct. 24–Nov. 21
Sagittarius (Archer)
Nov. 22–Dec. 21
Capricornus (Goat)
Dec. 22–Jan. 19
Aquarius (Water Bearer) Jan. 20–
Feb. 18
 Virgo (Virgin) Aug. 23–Sept. 22

Pisces (Fish)
Feb. 19–March 20
Important Astronomical Indications on the Dial
The small circle above the centre of the dial is the zenith, the point of the
sky directly above the observer’s head. The location of the zenith depends
on the latitudinal position the dial was made for: On the North Pole it
would be directly in the dial’s centre, on the equator it would be positioned
on the top of the equatorial circle.
<Insert picture \trilogy\pictures\as_zenith.tif>
The horizon line symbolises the zone where the Earth bars the
observer’s view of the sky – only celestial objects above that line are
visible. Its radius also depends on the latitudinal position. Under the
horizon is the twilight zone, shown as a grey area.
Since the sunlight is scattered in the upper regions of Earth’s atmosphere
and by atmospheric dust, there is still some light in the sky, even after the
Sun disappears under the horizon. Then it is only possible to see some of
the brighter stars. This time is the dusk, and is astronomically defined as
being the time between sunset and full night (or complete darkness), which
occurs, as the sun is 18 degrees below the horizon. The same is also valid
in the morning, when the dawn begins with the sun reaching a position 18
degrees below the horizon, and ends with the sun rising above the latter.
What makes the Astrolabium’s dial look so complicated, is the pattern of
lines, which indicate azimuth and elevation lines and help to determine the
exact position of a celestial body in the sky. The horizon around us is
divided into 360 degrees, which makes it possible to find a star or a planet
in the sky just by means of two details: its azimuth, that means its angle
from the South direction, and its elevation above the horizon. The
Astrolabium’s dial has several guidelines, showing azimuths and elevation
angles of 30 and 60 degrees.
Reading the Positions of Sun and Moon
We have to remember, that the ecliptic is the plane in which – more or
less exactly – all bodies of our solar system are situated. Therefore, it is
only logical that Sun and Moon can be found somewhere on the ecliptic.
Intersecting the measure edges of the sun or the moon hands with the outer
rim of the ecliptical ring, indicates their exact positions.
<Insert picture \trilogy\pictures\as_position.tif>
In this example the Sun has disappeared about one and a half hours ago, and
reached a point about 18 degrees beneath the horizon. The Moon is still visible
in the western sky, but will also set in some hours.
Two circular lines on the dial depict the Tropic of Cancer and the Tropic
of Capricorn. Due to the 23 degrees-angle of the Earth’s rotation axis
towards the ecliptic (see illustration on page XX [9]), the Sun seems to
follow a curved path over the year. At the summer or winter solstices it
reaches the highest, respectively the lowest point on that curve.
<Insert illustration \trilogy\graphics\sunpath-7.ai>
The Sun’s curve over the year
When the Sun (depicted by the intersection of the sun hand’s measure
edge with the ecliptic circle’s outer rim) touches the Tropic of Cancer on
June 21st, it has reached its highest position in the sky, and the days will
become shorter from then on. On December 22nd, the Sun meets the Tropic
of Capricorn, symbolizing its lowest position and therefore the shortest day
of the year. On March 21st and September 23rd, the Sun crosses the third
line depicted on the dial, the equator. During these equinoxes, day and
night are equally long.
Sunrise and Sunset, Moonrise and Moonset
The same method is presenting us the exact display of sunrise and
sunset, as well as moonrise and moonset: The rise of the Sun or the Moon
means that they appear above the horizon. As soon as the intersection point
of the sun hand’s measure edge with the ecliptic’s outer rim meets the line
of the horizon on the dial, the sunrise occurs. Correspondingly it works
with sunset, as well as the rising and the setting of the Moon. Just look at
the intersection of the appropriate hand’s measure edge with the ecliptic;
when this point meets the horizon line, the awaited event occurs.
<Insert illustration \trilogy\graphics\as_sunset-7.ai>
As soon as the intersection of the sun hand’s measure edge with the outer
rim of the ecliptic reaches the horizon line, the Sun is rising or setting. The
picture shows the latter being the case. Afterwards, the Sun will still be in
the dusk phase, until total darkness falls.
Dawn and Dusk
As long as the point symbolizing the Sun’s position is somewhere in the
grey twilight zone on the dial, there is some light in the sky, although the
Sun is not above the horizon. It is either early in the morning (dawn) – then
the sun hand/ecliptic intersection is in the left part of the twilight zone – or
late in the evening (dusk) – the intersection point is in the right part. As
soon as the intersection point leaves the dusk zone, it becomes completely
dark.
Depicting the Apparent (Temporal) Time
As has been explained above (page XX [7]), days and nights once had
been subdivided into twelve hours each, without regard of the fact that
during winter, nights were far longer than during summer. This apparent or
temporal time was abandoned only after accurate mechanical clocks
became commonly available. The Astrolabium still shows those temporal
hours for the nighttime. Doing the same for daytime as well, would have
cluttered the dial and therefore reduced its legibility. In the night half of the
dial, twelve roman numerals depict the apparent time. Again, the sun
hand/ecliptic intersection shows the current hour, but also the differing
duration of an apparent hour in summer and winter. As a result of the wish
to keep the dial more legible and clear, the limited series platinum
Astrolabium does not show the temporal hours.
<Insert picture \trilogy\pictures\as_apparent.tif>
After sunset, the point of intersection of the sun hand with the ecliptic’s outer
rim, together with the roman numerals shows the current apparent (or temporal)
time. Here it is about 2.15 o’clock of the nighttime – in summer, when the days
are longer it would barely be one o’clock, because the sunset is much later.
Observing the Fixed Stars
Due to the Earth’s course around the Sun, the fixed stars and stellar
constellations visible in the sky greatly differ with the seasons on Earth.
During winter, one can see other constellations than during summer. All
these factors are taken into account by the complex mechanisms of the
Astrolabium, so that at any time, you can determine which important stars
are currently in the observer’s hemisphere. Many of the brighter fixed stars
are printed on the transparent rete of the Astrolabium. As soon as they
appear above the horizon line, they are visible in the sky – if it is night, of
course. These stars are the main stars (stars of the first magnitude) of
important stellar constellations. Due to the limited space on the
Astrolabium’s dial it was not possible to depict the complete constellations.
Therefore, they are listed in the following table:
Stars on the Dial
Constellation
Stars on the Dial
Constellation
Aldebaran
Antares
Arkturus
Taurus (Bull)
Scorpius (Scorpion)
Bootes (Herdsman)
Mira
Pollux
Procyon
Atair
Beteigeuze
Capella
Aquila (Eagle)
Orion (Hunter)
Auriga (Charioteer)
Regulus
Rigel
Sirius
Deneb
Fomalhaut
Cygnus (Swan)
Piscis Austrinus
(Southern Fish)
Spica
Vega
Cetus (Whale)
Gemini (Twins)
Canis Minor (Smaller
Dog)
Leo (Lion)
Orion (Hunter)
Canis Major (Greater
Dog)
Virgo (Virgin)
Lyra (Lyre)
<Insert picture \trilogy\pictures\as_stars.tif>
The highlighted area on the dial is the celestial half-sphere currently visible from
the observer’s position. The stars, which are printed on the rete disc, are the
main stars of important stellar constellations. They rotate slowly from east to
west, so together with the four directions and their distance from the horizon (=
red outline), they can be spotted in the dark sky.
The sun hand shows whether the stars are currently observable or not.
Smaller stars can be seen only after dusk or before dawn, when it is
completely dark. The Astrolabium dial not only informs us about the stars’
visibility, but also about their current position in the sky, so they can be
found more easily.
The uppermost position of the dial at twelve o’clock is south, down at
six o’clock is north, three o’clock is west, and nine o’clock is east.
Finding Directions
Directions can be found by sighting the Sun (if it is visible) over the sun
hand, or by doing the same with the Moon and the moon hand. The four
points of the compass are indicated by the roman numerals XII (South), III
(West), VI (North) and IX (East) on the bezel.
<Insert illustration \trilogy\graphics\astro_dir-7.ai>
Moon Phases
<Insert illustration \trilogy\graphics\astro_phase-7.ai>
The positions of the sun and the moon hands relative to one another
indicate the current phase of the Moon. It is essential to remember the path
of the Moon around the Earth in relation to the Sun as explained above
(page XX [12]). Then it is easy to understand the moon phase display of the
Astrolabium at a glance. The axis of the hands can be understood as the
location of the Earth. If the moon and sun symbols on the ends of the
corresponding hands cover each other on the same side, it means that –
regarded from the Earth – both celestial bodies are on the same side. The
result is new moon, since the illuminated side of the Moon is facing away
from the Earth.
<Insert picture \trilogy\pictures\ea_mo2.tif>
Earth and Moon as seen from Mariner 10
If the sun and moon symbols are opposing each other with the Earth
(axis of the hands) in the centre, it is full moon. The Moon’s illuminated
side is fully visible from the Earth. The periods between these two events
show the Moon either waxing or waning.
Eclipses
The last hand, which has not been mentioned before, is the so-called
dragon hand. However, it is shaped more like a snake. It turns slightly
faster than the rete, and symbolizes the nodes, where the lunar orbit
intersects the ecliptic (see above, page XX [13]). Only when the new moon
or full moon occurs on such a node, an eclipse takes place. This can be seen
on the Astrolabium, when either the tail or the head (it doesn’t matter
which) of the dragon hand is in coverage with the other two hands. At new
moon, there is a solar eclipse somewhere on the world, and at full moon a
lunar eclipse occurs.
<Insert illustration \trilogy\graphics\astro_ecl-7.ai>
However, keep in mind, that if the dragon hand does show an eclipse
occurring, this does not necessarily mean you can observe it. As it has
previously been pointed out, a lunar eclipse is visible from the Earth’s night
side only, and a solar eclipse is casting a very small shadow on the Earth’s
surface. Therefore, it is observable from that narrow shadow zone
exclusively – if it is a total eclipse at all, since partial or ring shaped
eclipses are far more numerous.
Setting the Astrolabium
<Insert picture \trilogy\pictures\as-crown_new.tif>
Although the mechanism of the Ulysse Nardin Astrolabium is complex,
it is very easy to adjust it to the correct time whenever this might be
necessary. The perpetual calendar can be corrected forward or backward
anytime and without any restriction. All indications can be set by means of
the crown only, which means, that no additional correction device, such as
pushers, is needed.
The Astrolabium’s crown has three positions; each of them serves a
specific purpose:
Position 1: The watch movement can be wound manually.
Position 2: This position serves to set the sun hand, which moves together
with the moon hand, the dragon hand and the rete. The hour
and minute hands of the normal/legal time do not move when
the crown is in this position.
Position 3: The hour and minute hands can be set to the proper time – all
other indications automatically are properly adjusted.
How to Set the Astrolabium When it was Stopped for a Time
1.
2.
Manually wind the watch a little, with the crown in position 1.
Pull out the crown completely (in position 3), and set the hour and
minute hands to the current (legal) time. Push the crown back
completely into position 1.
3.
Then pull the crown out into position 2. Assume that the watch has
not been worn since the end of April 2000 and has stopped running.
Today is May 21st, 2000. If you take a calendar, which also shows
the moon phases, you learn that the last full moon was on May 18 th.
Therefore, turn the sun hand, until it points to a place somewhere in
the middle of the “MAY” field printed on the calendar rim. Continue
turning until the sun and moon symbols are positioned directly
opposite of each other, which depicts the full moon. If you have
turned too far, you only need to turn the hands backward, this is no
problem for the watch’s mechanism. Then count each further
complete revolution of the sun hand, which equals one day. Turn the
sun hand three times to reach the desired date, May 21 st. Then set the
sun hand to the proper local or solar time, according to the
longitudinal position of your current location.
If the watch has not been running for a long period, for some years even,
you can use solar or lunar eclipses as reference dates.
How to Adjust the Astrolabium to a New Location
If you change your location along the same degree of latitude, you can
adjust the Astrolabium in order to indicate the astronomical events
correctly. Of course, any minor changes in your latitudinal (North–South)
location do not have grave consequences, but a journey of several thousand
miles to the North or the South would make a change of the dial necessary,
since this has to be calibrated to your latitudinal location by Ulysse Nardin.
Travelling within the east–west direction of your location only changes
the solar time, which means the time when the Sun rises or is in the zenith.
In order to have the Astrolabium display its astronomical indications
correctly, it is necessary to synchronize the sun hand with the factual
course of the Sun in the sky. When the Sun has reached its highest point,
the Astrolabium’s sun hand must show twelve o’clock on the 24-hoursbezel. There are two ways to achieve this: The most simple way would be
to find a sundial and set the Astrolabium according to the time indicated by
the sundial’s shadow pointer. The more complicated, but also better and
more scientific way would be to use the current Greenwich Mean Time
(GMT) as reference time. If you know your current time zone, for example
–5 hours for the time on the United States’ East Coast, you can easily
calculate the correct Greenwich time. Just keep in mind, that GMT does not
have any daylight saving time, so you might have to deduct or add an hour.
In the appendix a GMT chart is printed, which can be of assistance.
After having calculated the current Greenwich time you need the
geographic co-ordinates of your current location; a good atlas or a modern
GPS receiver can deliver this information. Only the values of the degrees to
the West or East are needed. An example: The city of Chicago is located at
87.5 degrees west from Greenwich. As we know, the Earth needs four
minutes for every degree to rotate; therefore, the time difference between
Greenwich and Chicago is five hours and fifty minutes. When it is noon in
Greenwich (without regard to daylight saving time), the sun hand of the
Astrolabium in Chicago has to be adjusted so that it is directed to a point
shortly after the Arabic 6 (respectively the roman IX) on the bezel.
The Planetarium
<Insert picture \trilogy\pictures\planetarium.tif>
For most of the time in the history of human civilisation, the science of
astronomy was more or less identical with that of astrology. From the
beginning, the observation of celestial bodies served religious purposes,
and the most prominent of those bodies, especially the planets, were
identified with different deities. All gods were attributed individual
characteristics, which again were projected onto their planets. Therefore, it
is understandable that their positions relative to the Earth were considered
decisive for the different divine influences. The knowledge about the
planets’ exact position became crucial for astronomers, and soon
automatons were developed to display that information. After 16 years of
building time, in 1364, the Italian mathematician and astronomer Giovanni
Dondi finished his Astrarium, or Planetarium. This medieval masterpiece
of clockmaking not only displayed hours and minutes (the latter for the first
time since mechanical clocks were invented), but also a religious perpetual
calendar, and the position of the known planets. In later centuries, the
planetaria, which since the 18th century were also called orreries, became
extremely popular. These mechanisms mainly served the purpose to
facilitate the necessary astrological calculations, but also to educate the
people about the planetary system as God’s creation as well as Earth’s
place in it.
<Insert \trilogy\pictures\orrery_brit.tif>
Orrery, made by the English astronomer James Ferguson, as depicted in the
first edition of the Encyclopædia Britannica (1768)
The introduction of the heliocentric system by Copernicus caused several
problems. Not only did it remove the Earth from the centre of the known
universe, degrading it to but one of several planets orbiting around the Sun,
and thus challenged the whole system of the world as supported by the
Church. Yet it also overthrew all the conceptions of the planets’
movements around the Earth and their astrological importance. The later
astrolabes, built according to the new system made any astrological
calculations based on the planets’ angles toward the Earth, very difficult, if
not impossible.
<Insert \trilogy\pictures\buergi.tif>
Jost Bürgi (1552–1632), Swiss mathematician
However, one man solved the discrepancy between scientific knowledge
and astrological needs, by simply combining both systems into one
automaton or clock: Jost Bürgi (1552–1632), a Swiss mathematician, who
was also a gifted watchmaker, physician and astronomer. He invented the
logarithmic system, he was one of the very first clockmakers to use a
pendulum to adjust clockworks, and he also was the assistant to Johannes
Kepler. In 1605, he built a clock with a planetarium dial, now held in the
collection of the Museum of History of Arts in Vienna, Austria.
<INSERT picture \trilogy\pictures\bg-clock.tif>
This astronomical clock, built by Jost Bürgi in 1605, is now held by the Museum
of History of Art in Vienna. Its unique display of the solar system on the upper
dial inspired Ludwig Oechslin when he drafted his Planetarium. The clock’s
lower dial features Sun, Moon and a dragon hand for the eclipses, strongly
resembling the display on the Astrolabium.
On that dial, Bürgi combined both views of the world by means of taking
a fixed axis between the Sun and the Earth as the reference for all the
planets’ movements. This resulted in the brilliant compromise of still
allowing correct astronomical observations of the planets’ movements
relative to the Earth, while offering the radical new view of the world with
the Sun in the centre of the solar system.
<INSERT picture \trilogy\pictures\bg-clockdial.tif>
The upper dial of Bürgi’s magnificent clock shows the typical continental style of
planetaria, where the planets are depicted by hands. The more figurative
depiction by small spheres was developed on the British Isles. Note the straigth
gridlines, which originally were ‘broken’, like those on the Ulysse Nardin
Planetarium. A later restoration of the clock is responsible for the wrong grid.
When Ludwig Oechslin saw this clock, he was immediately fascinated
by it and consequently, he suggested to Ulysse Nardin to build a similar
watch. So the Planetarium is displaying the planetary system in the same
way as the Bürgi clock. If any of Ludwig Oechslin’s creations can be
understood as a homage to anything or anyone, it is the Planetarium,
dedicated to the mathematician, physician, astronomer and watchmaker
Jost Bürgi, whom Oechslin admires as one of the most important scientists
of his time.
Interpreting the Planetarium
Compared to the highly complex-looking Astrolabium, the Planetarium
even seems to be simple; a wrong perception, of course. However, it is a
fact that much of the Planetarium’s complexity hides behind the dial.
Reading the Normal Time
The hour and minute hands show the current time on the bezel, which is
engraved with the Roman numerals from I to XII. Both hands are covered
with luminous mass, to make them legible in the dark (except the limited
series platinum Planetarium).
Calendar and Zodiac
Between dial and bezel, a ring is rotating clockwise once a year, showing
both the current month and the appropriate sign of the zodiac (see the table
above, page XX [30]). A line, leading from the sun to the engraved number
XII, facilitates the exact reading of this information. The calendar is again
based on the exact duration of the Earth’s revolution around the Sun; 365
days, 5 hours, 48 minutes and 46 seconds. Since it does not subdivide its
indication into full days, the insertion of any leap days every four years is
not necessary – the Planetarium’s calendar is always correct.
<Insert picture \trilogy\pictures\pla_dial_new.tif>
While the hour and minute hands, together with the Roman numerals engraved
into the bezel, show the legal time, the ecliptic serves as calendar and zodiac
indicator.
The small markers on the ring’s rim are there to help the reading within a
month, together with the reference line between the Sun and the Roman
figure XII on the bezel; a small polished index shows the beginning of each
month.
<Insert illustration \trilogy\graphics\pla_cal-7.ai>
The progress of the month’s weeks can be followed by means of the reference
line between the Earth and twelve o’clock.
Small lines then symbolize the weeks within the month. With the
exception of February, all months last longer than four weeks; some have
30, others 31 days. Therefore, eleven of the twelve months are subdivided
into five segments, four of them equally long, corresponding to four weeks.
The fifth segment stands for the two, respectively three days, where the
months last longer than four weeks. February normally lasts exactly four
weeks (28 days). Therefore, it is subdivided into four segments only. Since
the calendar ring needs a little bit more than one year for one complete
revolution, the indication of the weeks will increasingly lag a little bit
behind the ‘civil’ calendar we are using. After four years, this lag sums up
to approximately one day, and after the civil calendar introduces a leap day
in February, the Planetarium’s calendar ring is again on a par with the civil
calendar.
The same is valid for the further differences between the factual solar
year and our civil calendar year (see above, page XX [10]). One has to
keep in mind that the Planetarium’s calendar ring is following the true solar
year, and not the year we have printed on our calendars. It is our civil
calendar system which deviates from the astronomical reality, because it is
based on the completion of full days. Since the subdivision on the
Planetarium’s calendar ring is so small, any difference between its display
and our civil calendar as small as a fraction of a day hardly matters.
All twelve signs of the zodiac subdivide the Earth’s complete revolution
around the Sun into sections of 30 degrees each. To facilitate the
calculation of a planet’s position against the zodiac, the Planetarium offers
the more exact subdivision into segments of five degrees, which are
depicted by the small lines on the zodiac’s side of the calendar ring.
<Insert picture \trilogy\pictures\nasaplan.tif>
All planets of our solar system – except Pluto – are shown together in that
composition from pictures, sent back from NASA orbiters and probes.
Displaying the Planets
The Planetarium displays the six ‘classic’ planets, those known already
in the ancient past, since they can be spotted and observed with the naked
eye – including our home planet, the Earth of course. These planets have
been part of the astrological system developed over centuries. The outmost
three planets of our solar system, Uranus, Neptune and Pluto, are so remote
from the Earth, that they could be discovered only after the invention of the
telescopes, when astrology had lost much of its former importance: Uranus
in 1781, Neptune in 1846, and Pluto in 1930.
Following the example of Bürgi’s clock, the Planetarium displays the
Earth in a fixed position, so the planets, symbolized by small golden
spheres set into the planet rings, do not show their sidereal orbits around
the Sun, as an observer positioned outside the solar system would see them.
The Planetarium shows their movements in relation to that fixed axis
between the Sun and the Earth.
<Insert illustration \trilogy\graphics\planet_orbit-7.ai>
Point of reference for all observations on the Planetarium is the fixed axis
between the Sun and the Earth, so Earth’s rotation is simulated by the
movement of the ecliptic with the signs of the zodiac, while the other planets are
indicated in accordance to that system: The Earth as well as the inner planets,
Venus and Mercury, orbit the Sun faster than the outer planets (Mars, Jupiter
and Saturn). Therefore, these move clockwise on the Planetarium’s dial, while
in reality they, too, circle around the Sun in counterclockwise direction.
Please recall the analogy of the merry-go-round (above, page XX [9]). If
you step on it and observe the world outside, taking the axis between you
and the platform’s hub as a fixed point of reference, the movement of other
people on the playground appears different from what it would look like if
you, too, were standing outside the merry-go-round. Therefore, there is a
difference of the planets’ true – or sidereal – rotation times around the Sun,
and those observed from the Earth, relative to the axis Earth–Sun:
Sidereal rotation time
around the Sun
Theoretical rotation
time around the Sun
with a fixed Earth
Rotation time on
Ulysse Nardin’s
Planetarium
Mercury 87.969 days
115.877 days
115.9065 days
Venus
224.701 days
583.939 days
584.1 days
Mars
1 year 321.738 days
1 year 414.89 days
1 year 414.8923 days
Jupiter
11 years 314.9 days
398.875 days
398.8976 days
Saturn
29 years 167.2 days
378.0846 days
378.0948 days
This table also proves the magnificent mechanical precision of the
Planetarium’s mechanics, developed by Ludwig Oechslin.
It should be mentioned, however, that in spite of the high overall
accuracy of the Planetarium’s display, it is possible that planets are shown
in different locations than they are in reality. The reason lies in the
elliptical orbits, which all planets maintain around the Sun. The orbits are
all more or less eccentric, but the planet rings on the Planetarium dial had
to be perfectly circular. A different system would not have been possible in
a small wristwatch. Following Kepler’s law, an object on an elliptical orbit
would vary its speed, depending on where on the ellpse it is. On the
Planetarium, however, its speed is constant. Consequently, any difference
between the reality and the Planetarium display will eventually be evened
out over the year.
Determining the Planets’ Positions on the Dial
The Planetarium’s sapphire crystal shows a web of lines with the Earth
as their centre. These lines span segments of 30 degrees, which help
locating the planets relative to the signs of the zodiac. They are not straight,
which is caused by the scaling of the planets’ distances on the dial.
The orbit of the inner four planets (Mercury, Venus, Earth and Mars) are
relatively near each other, so it was possible to make their planet rings on
the Planetarium in the same distance scale relative to the Sun. However, the
outer two planets on the dial, Jupiter and Saturn, had to be treated
differently, since their distance to the Sun is so large. Had the distance
scale of the inner planets been maintained, the ring of Jupiter would have a
radius of 34 centimetres, that of Saturn even of 62 centimetres resulting in
a “wristwatch” with a diameter of more than 1.25 meters! This watch
surely would not be very convenient to wear!
<Insert illustration \trilogy\graphics\planets-7.ai>
The distances of the inner six planets from the Sun, depicted in scale (in
millions of kilometres).
<Insert picture \trilogy\pictures\mo_ea1.tif>
An unusual perspective: Earth seen across the lunar north pole, photographed
by the Clementine orbiter.
Therefore, the scale of Jupiter’s distance had to be reduced to a third and
for Saturn to a fifth. The lines of the ‘spider web’ on the crystal reflect this
change in scale. For each planetary ring they are drawn to show the area
which would be seen if the ecliptic was divided into segments of 30
degrees each. The starting point for the spider web is the fixed Earth,
whereas the downscaling of the planetary rings uses the Sun as point of
reference. Therefore, the lines’ angles have to be adapted correspondingly
on the rings of Jupiter and Saturn, resulting in the unique pattern displayed
on the Planetarium’s crystal. Thus the outer planets can be correctly located
against the circle of the zodiac in spite of the deviation in scale.
The Moon Phases
A small crescent is circling around the globe of the Earth, once exactly
in 29 days, 12 hours, 44 minutes and 2.9 seconds; a synodic month.
<Insert picture \trilogy\pictures\pla_moon.tif>
To read the actual phase of the moon, just keep in mind that the Moon is
rotating around the Earth counter-clockwise. As soon as the crescent is
exactly between the disc of the Sun and the Earth, it is new moon – the
illuminated side of the Moon does not face towards the Earth and therefore
is not visible. After that the Moon is waxing until it reaches the position
directly opposite the Sun with the Earth between. It is full moon, since the
Moon’s illuminated side is fully visible from the Earth. During the
following days the Moon is waning again, until the cycle repeats itself.
Setting the Planetarium
The planetary cycles can be easily set by means of the crown only; no
additional buttons or pushers are necessary. It is also possible to move the
planets forward or backward, so one could simulate the planetary
constellation at a given date.
<Insert picture \trilogy\pictures\pla_crown.tif>
The Planetarium’s crown has three positions:
Position 1: The watch movement can be wound manually.
Position 2: This position serves to move the calendar and the planetary
rings, as well as the Moon. One complete turn of the Moon
corresponds to 29.53 days or one month. The hour and minute
hands do not move when the crown is in this position.
Position 3: The hour and minute hands can be set to the proper time – all
other indications automatically are adjusted accordingly.
If the watch stopped for only a few days, the easiest way to reset it
would be with the crown in position 3. Any turn of the crown moves the
hour and minute hands as well as all the other indications although the
latter’s movements are so slow that it might be hard to recognize them. For
one day, the hour hand has to make two complete turns on the dial.
However, before anything you should wind the watch a little with the
crown in position 1, in order to supply the movement with some ‘energy’.
Sometimes, it happens that the watch is not worn for longer time spans;
weeks, months or even years. In that case, it would of course be hard work
to set the indications forward for years only by means of moving the hour
and minute hands. But there is a much easier way to accomplish this. In
position 2, the crown allows to move the astronomical indications
(planetary and calendar rings as well as the Moon) 800 times faster than in
the normal time setting position (pos. 3). The years change into minutes, so
the watch can be reset very quickly. But what is even more important: It
makes incredible fun to have the planets at one’s command – letting them
orbit at your will can make you feel like Mickey Mouse as the “Sorcerer’s
Apprentice”! Just remember your original starting point, to reset the watch
correctly after playing with it.
If it is necessary to move the indications forward more than just a few
days, it’s best to use the quick correcting function of the crown (pos. 2) to
find a good reference point. Here it is possible to advance by the days with
the crown in position 3. The starting points can be:
a) Full moon,
b) new moon,
c) the first day of a month, or
d) the first day of a zodiac sign.
There are two ways how these points can be read on the watch: either by
means of the appropriate markers on the calendar/zodiac ring, lining up
with the thin line stretching from the Earth to the twelve o’clock-position,
or by the crescent orbiting around the small globe of the Earth and its
position relative to the Sun. Just move forward the indication to whatever
reference point is nearer to your actual date. Then pull out the crown into
position 3 and make the fine adjustment by moving the hour and minute
hands.
If the watch has to be updated after it was stopped for years, move
forward its indications until the positions of the planets correspond to the
following depiction:
<Insert illustration \trilogy\graphics\planet_set-e-correct.ai>
These pictures show the planets, how they were positioned on the
Planetarium’s dial on January 1st, 2004, 2006, 2008 and 2010. The
depictions are not 100% accurate, but illustrate the constellations well
enough for our purpose. Turn the crown, until the constellation is similar to
one of those shown. Then you have a known date, from which it is rather
easy to continue: While now turning the crown, observe the
calendar/zodiac ring. Each complete turn of this ring equals one year.
Continue until you reach a full moon, or whatever starting point listed
above is nearest to your desired date. Then pull out the crown into position
3 and advance by the hours.
Sometimes the friction clutch system, which protects the delicate gearing
system from damage, can shift the ecliptic (calendar/zodiac) slightly
forward or backward. Mostly this will be barely noticeable, but if
necessary, it can be easily corrected by turning the calendar ring with the
crown in position 2.
The Tellurium
<Insert picture \trilogy\pictures\tellurium.tif>
Telluria always were important parts of large astronomical clocks,
because they concentrated their display on those celestial bodies, which are
especially important for the human life: Sun, Earth and Moon. By means of
the globes displayed by the automatons, one could easily distinguish the
areas where it was night or day, while the Moon’s position allowed to
determine its current phase.
After the heliocentric view of the world had finally gained common
recognition, the telluria normally showed the Sun in the centre, and Earth
together with the Moon orbiting around it. The Tellurium of Ulysse Nardin
changes that. Here the Earth is positioned in the dial’s centre, leading the
term “Tellurium” back to its original roots. “Tellus” is Latin and the
Roman analogy of the Greek Gaia, goddess of Earth. Gaia was the centre of
the world, the origin and the final destination of everything living and
growing. Ludwig Oechslin’s Tellurium reinstalls Gaia’s position as the
centre of our every day life. As the completing piece of the Trilogy of Time
it also marks the central point on a journey through the cosmos. After
looking at the complex concert of the planets and their movements, the
view concentrates on the place where we live.
In its principle, the Tellurium is a close relative to the Planetarium, its
dial being a detailed extract of the latter. Both, Sun and Earth are in fixed
positions, while the cosmos, symbolized by the zodiac, rotates around
them.
Interpreting the Tellurium
Compared with the other two pieces of the Trilogy, the Astrolabium and
the Planetarium, the Tellurium outwardly looks simple. But when studied
in detail, it discloses itself as being astonishingly complex. By presenting a
rotating Earth as viewed from above the North Pole, it is a perfect world
time watch, showing the current time on each place on the Earth.
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The Tellurium concentrates on a detail of the Planetarium – the system of
Sun and Earth. Both are fixed in their positions and the movement of the
ecliptic is shown in relation to the axis connecting them.
Reading the Time
The legal time currently valid at the user’s location, is indicated by the
hour and minute hands on the bezel, which have the figures 1 to 11 (the 12
is showing the Sun symbol) inlaid in blue lacquer. Contrary to conventional
watches, these ‘hands’ are mounted on concentric rings, which turn around
the central dial. They are covered with luminous mass, so it is possible to
read the time in the dark.
Calendar and Zodiac
Between the central dial plate depicting the Earth and the hour and
minute hands’ rings, the calendar/zodiac ring is rotating. A full rotation
needs 365 days, 5 hours, 48 minutes and 46 seconds, which corresponds to
the Earth’s true rotation period around the Sun. A fine line etched into the
sapphire crystal is serving as a reference aid.
The calendar and zodiac ring works the same way than that of the
Planetarium, therefore the reader is asked to look at the appropriate chapter
for reference (see above, page XX [40]). The only difference to the
Planetarium’s calendar is the lack of the five-degrees-markers on the
zodiac’s side of the ring. Since the Tellurium does not have any planets to
be spotted against the zodiac, these indications are not necessary.
Illumination of the Earth
The primary purpose of the Tellurium is to show Earth’s current
illumination by the Sun on its central dial. The Sun itself is depicted by the
small symbol at the twelve o’clock position of the bezel.
The globe of the Earth is seen from above the North Pole, but in this type
of geometric projection, a larger part south of the equator is also visible.
Within one day or 24 hours, the disc completes one revolution. The
numbers on the outer rim show the 24 time zones, beginning with the prime
meridian at Greenwich, near London. In order to indicate night and day on
Earth correctly, the disc always has to be synchronized with the World
Time, also called Greenwich Mean Time (GMT). Twelve o’clock GMT
means that the Sun has reached its highest point in the sky over Greenwich.
A line passing through the depiction of the British Isles is the prime
meridian and marks the starting point of the time zones. Another fine line
in the sapphire crystal facilitates the reading of the Greenwich time.
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The area of the Earth disc above the spring is illuminated by the Su,n which is
placed as a symbol at twelve o’clock. While the disc turns counterclockwise, the
continents depicted rotate into the sunlight (sunrise) or into the shadowed part
of the Earth (sunset). The numbers on the Earth disc’s outer rim stand for the
24 timezones while their starting point, the prime meridian at Greenwich,
England, is shown by the golden line on the disc. The upper reference line
stretching from the sun symbol allows reading the current Greenwich time.
A gold-plated spring stretches across the Earth, showing the current
border between daylight and night. The disc’s rotation reproduces the
sunrise in the East and the sunset in the West, when the continents,
depicted in enamel, pass under the spring. Since Earth’s rotation axis is
slanted some 23 degrees relative to the ecliptic, the lengths of night and day
change over the year, resulting in the seasons. The spring also reflects this
by changing its tension. When it is summer on the Northern Hemisphere,
the spring is bent downward, in the direction of the six o’clock position.
Then the North Pole can see the polar summer taking place in the sunlight.
At the summer solstice (June 21st) the spring has reached its lowest curve,
indicating the longest day. Afterwards the curvature is slowly flattened, and
on September 23rd the spring is completely straight and horizontal, with day
and night equally long on that equinox. During the following weeks, the
spring is bending upward, leaving the North Pole in its dark polar night and
indicating the steady shortening of the days, until – on December 22nd –
this process too, has reached its climax. Then everything reverses again,
with the spring displaying the next equinox on March 21st.
Theoretically it is possible to estimate the times of sunrise and sunset for
every place on the Earth. Simply find the desired location on the small
world disc, and by using the time zones as a base, calculate how many
hours separate this point from reaching the spring. But please keep in mind
that the enamel disc is a piece of art more than a geographically correct
depiction of the Earth, so all these calculations are very rough estimates –
which by no means reduces the fun one has when doing this kind of
exercise!
The Moon Phases
As the other two watches of the Trilogy series do, the Tellurium, too,
displays the current phase of the Moon, but its depiction is more authentic
in appearance than the more or less abstract moon phase displays by means
of hands or a small crescent.
As in reality, the Tellurium’s Moon circles the Earth counterclockwise,
based on the synodic month (29 days, 12 hours, 44 minutes and 2.9
seconds). To illustrate the Moon’s illumination by the Sun, the gold painted
half of the moon disc always faces the “Sun” at twelve o’clock, while the
dark half depicts the Moon’s shadowed parts, which appear invisible from
the Earth. At new moon the Moon is between the Sun and the Earth, with
its illuminated side directed away from Earth – the Moon seems invisible.
When its path guides it around the Earth, the Moon is waxing until it
reaches the position directly opposite the Sun. Then its illuminated side is
fully visible from the Earth, it is full moon. Afterwards the illuminated
crescent becomes smaller and smaller; the Moon is waning, until the cycle
is completed with the next new moon.
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The Moon is depicted by a small disc rotating counterclockwise
around the Earth. The dragon’s head and tail indicate solar or lunar
eclipses if they align with a new or full moon, respectively.
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The Tellurium’s moonphase display is shaped after the nature: Here the Moon
is seen circling around the Earth by the Galileo orbiter.
Solar and Lunar Eclipses
The dragon hand, of which only the head and the tip of the tail are
visible, symbolizes the nodes where the lunar orbit intersects the ecliptic
(see above, page XX [13]). These nodes’ positions also rotate slowly
around the Earth, and only when full moon or new moon occur on or near
such a node, the view from Earth on either the Sun or the Moon is partially
or fully obstructed. The new moon results in a solar eclipse, where the
Moon’s disc blocks the Sun, and the full moon disappears in a lunar
eclipse, when it is darkened by Earth’s shadow.
These occurrences are depicted on the Tellurium when either the
dragon’s head or its tail meets the moon disc at the twelve o’clock position
(solar eclipse), or the six o’clock position (lunar eclipse). It is not necessary
for the hand and the moon to be perfectly aligned for an eclipse to happen.
The dragon hand only shows that in this case the Moon is on or near the
node of its orbit. Even if dragon hand and the moon are a little bit off, the
conditions for an eclipse might be fulfilled.
As I pointed out previously, the indication of an eclipse on the
Tellurium’s dial does not mean that it is observable from everywhere on
Earth. Lunar eclipses can only be seen on the night side of the Earth, and
solar eclipses are visible on very small areas of the dayside only (see the
visibility map of solar eclipses on page XX [13]).
How to Set the Tellurium
The indications of the Tellurium can be easily set, only the crown and a
single pusher on the watch’s left side are needed.
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The Tellurium’s crown has three positions:
Position 1: The watch movement can be wound manually.
Position 2: This position serves to move the astronomical indications –
ecliptic (calendar/zodiac), moon and dragon hand. The hour
and minute hands and the Earth’s disc in the centre do not
move when the crown is in this position.
Position 3: The hour and minute hands and the current GMT (by means of
the central disc) can be set to the proper time. All other
indications are adjusted accordingly. When pressing the pusher
while the crown is in this position, the astronomical
indications do not move when the time is set.
How to Correct the Setting by Short Time Spans (Daylight
Saving Time)
Regardless to the time span during which the Tellurium was stopped, it
always can be reset to show the proper time very quickly. If this time span
was short, it is the easiest way to reset it with the crown in position 3.
Nevertheless, before advancing, always wind the watch a little with the
crown in position 1, so that the movement has some ‘energy’ to keep the
watch working. In position 3, any turning of the crown moves the hour and
minute hands, as well as all the other indications. For one day, the hour
hand has to make two complete turns on the dial, and the Earth’s disc at the
same time rotates once.
Always set the current World Time or GMT first! This is the time of
Greenwich near London, without any daylight saving time set. So first you
have to know your current time zone. The GMT chart printed in the
appendix can be of assistance. On the United States’ East Coast, for
example, you have to add five hours to get the current GMT. During
summer, however, you only have to add four hours, since the daylight
saving time already has added one hour.
Let us assume you are living in Washington, D.C. and have to reset the
Tellurium, which did not run for a day. Your actual time is 10.15 a.m. In
Greenwich time this would be 03.15 p.m. (or 15.15). During daylight
saving time, 10.15 in Washington would be only 14.15 in Greenwich. In
position 3 turn the crown, until the reference line beneath the “Sun” at
twelve o’clock aligns with the correct GMT on the 24-hour indicator on the
world disc. Now you have set the world disc to show the correct phase of
the day. Then press the pusher on the watch’s left side and hold it, while
you turn back the hour and minute hands with the crown until they
correctly show 10.15 o’clock, the time on your current location.
Basically the same procedure is followed on the days when the daylight
saving time is introduced or ended, or if you are travelling into a different
time zone, although it generally is dispensable to change the GMT setting
of the Earth’s disc if the watch was running all the time. Therefore, you
only have to pull out the crown into position 3, press the pusher and hold it,
while you set the new time by turning the crown.
Changing the Time, Taking into Account long Time Spans
If it is necessary to change the indications for more than just a few days,
it is the best to use the quick correcting function of the crown (pos. 2) to
find a good reference point. It is then possible to advance by the days with
the crown in position 3. The starting points can be:
a) Full moon,
b) new moon,
c) the first day of a month, or
d) the first day of a zodiac sign.
These points can be read on the watch by means of the appropriate
markers on the calendar/zodiac ring, lined up with the thin reference line
beneath the sun symbol. Alternatively, the moon disc orbiting around the
disc of the Earth and its position relative to the Sun can serve as an
adjustment aid. Just move the indication forward to whatever reference
point is nearer to your actual date. Then pull out the crown into position 3
and make the fine adjustment by moving the hour and minute hands. Here
you may first set the correct Greenwich Time again. Then press the pusher
and hold it while setting your current local time so that the other indications
do not change accordingly.
If the watch has to be updated after being stopped for over a year, move
its indications forward until the positions of the Moon and the dragon hand
correspond to the positions relative to the minute indications, as given in
the following table:
Positions of moon and dragon hand on January 1st 2000–2021
(relative to the minute indications)
Year
Moon
Dragon
Year
Moon
Dragon
2000
12
26
2011
9
1
2001
50
29
2012
47
5
2002
28
32
2013
25
8
2003
6
36
2014
3
11
2004
44
39
2015
41
14
2005
22
42
2016
19
17
2006
60
45
2017
56
21
2007
37
48
2018
34
24
2008
15
52
2019
12
27
2009
53
55
2020
50
30
2010
31
58
2021
28
34
This table shows how the Moon and the dragon hand were positioned on
the Tellurium’s dial on January 1st, 2000–2021. From that point turn the
crown (in position 2) and observe the calendar/zodiac ring: Each complete
turn of this ring equals one year. Continue until you reach a full moon, or
whatever starting point listed above is nearest to your desired date. Then
pull out the crown into position 3 and advance by the hours, until the
correct GMT is reached. Finally, press the pusher and hold it while you set
the desired local time.
Sometimes the friction clutch system, which protects the delicate gearing
system from damage, can shift the ecliptic (calendar/zodiac) slightly
forward or backward. Mostly this will be barely noticeable, but if necessary
it can be easily corrected by turning the calendar ring with the crown in
position 2.
APPENDIX: INTERNATIONAL TIME ZONES
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ACKNOWLEDGMENTS
Text and illustrations: Dr. Marcus Hanke, University of Salzburg;
photographs: pages XX [3], XX [5], XX [12], XX [14]: Marcus Hanke,
Salzburg;
page XX [39]: Museum of History of Arts, Vienna;
pages XX [11], XX [34], XX [41], XX [43], XX [50]:
NASA;
page XX [19]: Türler, Zurich;
all others: Ulysse Nardin, Le Locle.