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SWISS WATCHES IN THE LIGHT OF HISTORY: FROM ANCIENT TO MODERN TIMES

EVELINA RIOUKHINA

To measure time
Little is known about the details of timekeeping in prehistoric eras; however, records and artefacts show that in every culture people were preoccupied with measuring and recording the passage of time. Ice-age hunters in Europe over 20,000 years ago scratched lines and gouged holes in sticks and bones, probably counting the days between
phases of the moon. Five thousand years ago, Sumerians in the Tigris-Euphrates valley in today’s Iraq had a calendar that divided the year into thirty-day months, divided the day into 12 periods (each corresponding to two of our hours), and divided these periods into 30 parts (each like four of our minutes). There are no written records of the creating of Stonehenge, built over 4000 years ago in England, but its alignments show its purposes apparently included the determination of seasonal or celestial events, such as lunar eclipses or solstices.
The earliest Egyptian calendar was based on the moon’s cycles, but later the Egyptians realized that the “Dog Star” in Canis Major, which is now called Sirius, rose next to the sun every 365 days, about when the annual inundation of the Nile began. Based on this knowledge, they devised a 365-day calendar that seems to have begun in BC 4236, the earliest recorded year in history. In Babylonia, again in Iraq, a year of 12 alternating 29-day and 30-day lunar months was observed before BC 2000, giving a 354-day year. In contrast, the Mayans of Central America relied on not only the sun and moon, but also the planet Venus, to establish 260-day and 365-day calendars. This culture flourished from around BC 2000 until about AD 1500 They left celestial-cycle records indicating their belief that the creation of the world occurred in BC 3113 Their calendars later became portions of the great Aztec calendar stones. Other civilizations, including the modern West, have adopted a 365-day solar calendar with a leap year occurring every fourth year.

Not until fairly recently in terms of human history did people find a need for knowing the time of day. As best we know, 5000 to 6000 years ago great civilizations in the Middle East and North Africa initiated clockmaking as opposed to calendar-making. With their attendant bureaucracies and formal religions, these cultures found a need to organize their time more efficiently.

Sun Clocks
The Egyptians were the first to have formally divided their day into parts something like our hours. Obelisks (slender, tapering, foursided monuments) were built as early as BC 3500 Their moving shadows formed a kind of sundial, enabling citizens to partition the day into two parts by indicating noon. They also showed the year’s longest and shortest days when the shadow at noon was the shortest or longest of the year. Later, markers added around the base of the monument would indicate further time subdivisions.
Another Egyptian shadow clock or sundial, possibly the first portable timepiece, came into use around BC 1500 to measure the passage of “hours.” This device divided a sunlit day into 10 parts plus two “twilight hours” in the morning and evening. When the long stem with five variably spaced marks was oriented east and west in the morning, an elevated crossbar on the east end cast a moving shadow over the marks. At noon, the device was turned in the opposite direction to measure the afternoon “hours.”
The merkhet, the oldest known astronomical tool, was developed in Egypt around BC 600. Two merkhets were used to establish a northsouth line by aligning them with the North Star. They could then be used to mark off night time hours by determining when certain other stars crossed the meridian. Many other sundial styles, of which Vitruvius could describe 13 different types, were in use in Greece, Asia Minor and Italy.

Water Clocks
Water clocks were another form of early timekeepers that did not depend on the observation of celestial bodies. One of the oldest was found in the tomb of Amenhotep I, buried around BC 1500. Later named clepsydras (“water thief”) by the Greeks, who began using them about BC 325, these timekeepers were stone vessels with sloping sides that allowed water to drip at a nearly constant rate from a small hole near the bottom. Other clepsydras were cylindrical or bowl-shaped containers designed to slowly fill with water coming in at a constant rate. Markings on the inside surfaces measured the passage of “hours”. These clocks were used to determine hours at night, but may have been used in daylight as well. Another version consisted of a metal bowl with a hole in the bottom; when placed in a container of water the bowl would fill and sink in a certain time. These were still in use in North Africa in the twentieth century.

More elaborate and impressive mechanized water clocks were developed between BC 100 and AD 500 by Greek and Roman horologists and astronomers. The added complexity was aimed at making the flow more constant by regulating the pressure, and at providing fancier displays of the passage of time. Some water clocks rang bells and gongs; others opened doors and windows to show little figures of people, or moved pointers, dials, and astrological models of the universe.

Since the rate of flow of water is very difficult to control accurately, a clock based on that flow could never achieve excellent accuracy.People were naturally led to other approaches.

The first mechanical clocks: Early timepieces in Europe
All modern clocks – down to the latest atomic clock, accurate to one second every 30 million years – depend on oscillation. An oscillator is a device which moves backwards and forwards at a regular speed. This regular movement chops time into segments, which can then be counted. The best known example is the pendulum, which is designed by the clockmaker to swing a precise number of times per second. (For example, in most pendulum wall clocks, it swings once every second.) The time of the swing depends on the length of the pendulum.
In the early-to-mid-14th century, large mechanical clocks, making use of oscillation, began to appear in the towers of several large Italian cities. There is no evidence or record of the working models preceding these public clocks that were weight-driven and regulated by a verge-and-foliot escapement. Verge-and-foliot mechanisms reigned for more than 300 years with variations in the shape of the foliot. All had the same basic problem: the period of oscillation of this escapement depended heavily on the amount of driving force and the amount of friction in the drive. Like water flow, the rate was difficult to regulate.

Portable time keeping
Peter Henlein of Nürnberg created the first pocket watch in 1480. It was made of gilded brass and had only one hand, giving the approximate time. Ball shaped it was yet oddly named a “Nürnberg Egg”. Religion was to have a strong influence on the watch industry, however indirectly. When the Protestant reformation took over Geneva in 1535 the city had no watch making industry to speak of and was known rather for its jewellery. However Geneva established itself in the years that followed as a haven of refuge for Protestants from Paris and other watch making centres. Calvin had imposed strict laws banning theatre, dancing, and other forms of art and entertainment. This included a ban on wearing elaborate clothing and jewellery. Initially this seemed like doom for Geneva’s many fine jewellers, but one loophole in Calvin’s laws gave them an opportunity. Calvin considered watches an item of practical use and therefore permissible. Geneva’s jewellers then collaborated with the watchmakers to decorate watches with jewels, enamel and engravings. This collaboration spawned the beginning of Geneva’s luxury watch industry.
In the second half of the 17th century the Dutch Christian Huygens invented the “Remontoire”. This kept a more constant force on the escapement. Also during this time the spiral hairspring for the balance wheel was invented, greatly improving the accuracy of time pieces. As now watches were accurate to within a few minutes a day a minute hand could be added on watch dials.
Truly accurate time keeping. In 1721, George Graham improved the pendulum clock’s accuracy to one second a day by compensating for temperature variations through changes in the pendulum’s length. Later in the century Thomas Mudge invented the English lever escapement. The watch could henceforth be wound without it stopping or losing time. John Harrison next refined Graham’s temperature compensation techniques and added new methods of reducing friction. By 1761, he had built a marine chronometer with a spring and balance wheel escapement that won the British government’s 1714 prize (of over $2,000,000 in today’s currency) since it offered a means of determining longitude to within one-half degree during a voyage to the West Indies. It kept time on board a rolling ship to about one-fifth of a second a day, nearly as well as a pendulum clock could do on land, and 10 times better than required.

Quartz mechanism
A major change occurred in the 1930s and 1940s when quartz crystal clocks replaced the pendulum, balance-wheel escapements and the spring as standard mechanisms, further improving timekeeping performance. In a quartz watch the oscillator is a quartz crystal, which has the property to vibrate in the presence of an electric field, produced in watches by miniature batteries. The high frequency of the vibrations means that a quartz timekeeper is very accurate – to within about one minute a year. In the 1960s it became possible to manufacture integrated circuits small enough to be used in wristwatches.

Atomic clocks
The atomic clock is the most recent development. It uses the oscillations of atoms of caesium-133. Their advantage is that they oscillate extremely fast and at exactly the same rate. Unlike quartz crystals, for example, they are unaffected by outside influences, such as temperature changes. An example is the FOCS-1, the most accurate clock ever developed in Switzerland, which started operating in 2004. It stands in a laboratory of the Swiss Federal Office of Metrology METAS in Bern. Were you to come back and look at it in 30 million years’ time, it would not have deviated by more than one second. Such extreme accuracy might at first sight seem superfluous, but it has a number of applications, apart from setting the official time around the world. Satellite navigation systems depend on atomic clocks, and the more closely synchronised they are, the more accurate the data the systems can deliver. Radio telescopes round the world can be synchronised as they observe the same point in the heavens, creating in effect a single telescope whose diameter is that of the earth.

Are the problems of accurate time-keeping solved? What are today’s challenges? Luxury? Accuracy? Design? Simplicity? Complications? Achieving the highest performance? Read about the role of modern Swiss watchmaking in the next instalment of Swiss Pages.