Cover image for Timepieces : masterpieces of chronometry
Timepieces : masterpieces of chronometry
Christianson, David, 1949-
Personal Author:
First edition.
Publication Information:
Buffalo, NY : Firefly Books, [2002]

Physical Description:
176 pages : illustrations (some color), portraits ; 25 cm
Format :


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TS542 .C58 2002 Adult Non-Fiction Central Closed Stacks

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Over the centuries, clocks have slowly, methodically and inextricably come to regulate every aspect of our lives. Timepieces tells the history of clocks and how the pursuit of an ever better clock has had a remarkable influence on scientific and technological developments. The 800-year journey to a perfect clock involved the greatest thinkers, scientists and mechanical geniuses, including those who improved the accuracy of mechanical clocks to such a degree that sailors could successfully determine longitude. That advance alone resulted in an explosion of travel, commerce and political expansion that would change the world map.

Tracing the history of "the key machine of the modern industrial age" is a remarkable way to trace the histories of technology and society. Each chapter focuses on one era of the clock's growth:

The Celestial Clock A Call to Prayer The Priceless Possession of a Few From Tabletop to Waistcoat and Beyond The Craft Era in Watchmaking The Industrial Revolution Swiss Watchmaking The Standardization of Time The Quartz Revolution

Illustrated with beautiful artworks and photographs from museums and clock collections, Timepieces is a thorough and attractive historical survey.

Author Notes

David Christianson is a renowned horological historian and has been a certified Master Watchmaker for 25 years. He is a past president of the American Watchmakers and Clockmakers Institute, where he teaches clock and watch restoration, and is a Fellow of the British Horological Institute, and also writes for Professional Jeweler magazine and Horological Times .

Reviews 1

Booklist Review

A renowned watchmaker unfolds horological history from the sundial to the atomic clock, accenting the inventions and artistry of the craft in a colorfully attractive book. Numerous diagrams show various versions of a device called the escapement, which meets watchmaking's central challenge: the even, continuous release of stored energy to track time. Although the escapement is about 500 years old, improvements have been made to it as recently as 1981. Christianson pairs technical aspects of the craft to the organizational side of watch manufacturing, describing how early modern guilds regulated it and also relating the eclipse of the individual craftsman by the mass production of the industrial age. Portraits and thumbnails of those prominent in this process, such as John Harrison, the hero of Dava Sobel's Longitude (1995), populate the work, which palpably bears the author's enthusiasm for his subject--except for modern innovations: "It's hard to love a quartz watch," he writes. However, all who are seduced by the aesthetics of a watch will find it easy to love Christianson's account. --Gilbert Taylor



Introduction: The Celestial Clock The natural rhythms of the earth -- the day as it turned into night and then turned to daytime again, the sun as it tracked across the sky, even the moon as it reappeared on a regular and predictable basis -- showed to early man that time was a continuous, even flow of predictable events. Even the seasons of humanity -- birth, maturity, old age and death -- were constant and predictable. But at one time the concept of time meant nothing to humans. Their days revolved around the natural rhythms of daylight and dark; springtime and fall. Nature told them when to sleep and when to work; when to plant and when to harvest; when to hunt and when to gather fuel and food for that long cold season that came after the season of falling leaves. Yet even in such a simple society, the hunter-gatherer found a need to pinpoint specific moments on this continuous, flowing line of time. If they wished to meet another to help with a hunt, for example, they needed to identify a particular moment on the line of time, so they looked for ways to isolate and communicate this reference point. They noted that the shadow of a tree grew progressively shorter as the sun rose to midday, and then grew longer on the other side of the tree as evening approached. They knew from previous experience that, as the sun peaked lower and lower in the sky, the cold season was approaching, and, after so many waxings and wanings of the moon, spring would again appear. So, with the need to interact with others and to prepare for the long winter ahead, humans learned early on to use and rely upon the sun and moon to map out their days and plan for the foreseeable future. They learned to use the celestial clock . A CLOCK IN THE HEAVENS The celestial clock is that natural timekeeper in the sky that tells us the passage of time: the days, the months and the seasons of the year. The ancients imagined a dome above the earth upon which the sun, the moon, the planets and the stars moved. Later, when we learned that the earth was round, the dome became a sphere. The hour is an interval of time. Its length and the number of hours in a day varied from culture to culture. But generally the daytime was divided into hours and the nighttime into periods of watches, when the guard would change in the towns and villages. Ancient Egyptians were probably the first to separate the day and night into 24-hour periods. This concept of the hour slowly spread throughout the Greek and Roman empires. The hours were called "unequal" or "seasonal" hours because their lengths varied with the changing seasons and between night and day, their length being tied directly to the length of the solar day . In the celestial clock, the sun is the hour hand. As it passes through the heavens from east to west, it casts a shadow that moves from west to east. When a stick was inserted at an angle into the ground, it became the first clock made by man to tell the time: the shadow clock cast a shadow that moved in a semicircle around the stick and the shadow was divided into even intervals of time by markers placed within its path. From this evolved the simple sundial with its angled style (the gnomon ) casting a shadow upon a base that had the hours marked upon its face. Being made first from caned stone and then from iron and later brass, sundials were not only small individual timekeepers, but were installed upon the faces of buildings to act as public timekeepers, too. The passage of the sun also tells the time of year. As the seasons pass, the path the sun takes across the sky moves each day, drifting to the north in the spring and summer months and to the south in the fall and winter (for those of us living in the Northern Hemisphere). In the summer, its path is higher in the sky. In the winter, the sun's path is lower, giving shorter days as it slips below the horizon more quickly than it does in summer. The sundial evolved to take advantage of this seasonal change in the sun's path, to show the time of day by the angle of the shadow and then the approximate date by the shadow's length. The monthly cycle of the moon, along with its journey through the 12 constellations of the zodiac, marks out the months and becomes the calendar function of the celestial clock. Sundials indicate the tides and tell of the seasons, predicting the times for successful sailing, planting and harvesting -- all patterns our ancestors needed to know. They also allowed humans to track events and anticipate events of longer duration than a day or a week. EARTHLY TIME Overcast skies and long winter nights enticed man to measure time on earth by emulating the heavenly cycles of the celestial clock. Since time is a continuous, even flow of events, it stands to reason that man should be able to measure time if he has some device that will move at a continuous, even rate. A damp, smoldering rope, for example, would burn at a relatively even rate. With a knot at each hour's interval, the burning rope would indicate the time since the start of the burn. A burning candle marked with bands would likewise indicate an hour's duration between bands or a burning oil lamp could be made to do the same, with its oil reservoir marked to indicate the hours. We are all familiar with the hourglass, filled with sand that trickles with a regular, consistent flow from one side of the glass to the other. Then there was the idea of a pail of water pierced with a hole through which a stream of water flowed. This, too, would be marked with indications to show the time as the level of water fell. Each had its limitations, The burning rope had to be awfully long to measure an event of any length, and it needed constant attention to make sure that it continued to burn. The oil lamp, too, needed almost constant attention. The hourglass could be made large enough to measure longer events, but, at these larger sizes, the sand tended to clump and clog the orifice through which it was supposed to flow so evenly. The water clock would freeze in winter, but it was quite reliable in the milder months and in the regions of the world that were free of freezing weather. Plato (c.428-c.347 B.C.), the Greek educator and philosopher, is credited with inventing the water clock, and it had the very practical application of regulating the length of speeches in the law courts of Athens! Improvements in the design had a floating figure point to the hour, or had the dripping water turn a small wheel, which connected it with a hand on a dial to show the time. A water clock was known as a clepsydra and could be made in any size, from a small one for personal use to a large tower clock using buckets and water wheels for public viewing. Muslims were concerned to know the time for their religious practices, but they loved to build water clocks that told the hour by sound and animation. Long before medieval Europe could do so, Muslim clockmakers added bells, gongs and moving figures, all choreographed by intricate gearing and regulated by the flowing water from their clepsydra. In fact, when the caliph of Baghdad wanted to impress Emperor Charlemagne he sent one of his magnificent clepsydras, as a gift and to show the Franks his nation's technological superiority at a time when the Frankish empire controlled all of Western Europe and was impinging upon his Islamic borders. SUN TIME AND CLOCK TIME With the advent of uniformly running timekeepers, such as burning candles and clepsydras, we soon discovered that there was a difference between sun time (or solar time) shown by the sundial and clock time . Solar time marked uneven hours. Depending upon the time of year, the 12 daylight hours may be longer that the 12 nighttime hours and vice versa. These daylight hours gradually lengthened and shortened throughout die year (unless you lived at the equator).The continuous, even flow of the clepsydra marked "even" hours. The 24 hours of the day were equal, regardless of whether they were in daylight or darkness, summer or winter. All of us, without exception, live by nature's dock. Daytime, nighttime, each season of the year -- they all repeat themselves in a rhythm that is imprinted on nearly everything we do. These rhythms correspond with our societal endeavors -- day for work, night for sleep; the sequence of seasons for planting, growth, harvest and rest-only to be repeated again and again. To the majority of people living in a rural atmosphere, the idea of uniform (or equal) time meant nothing as far as work and sleep, planting and harvesting went. But to city dwellers, away from the animals that would awaken them at dawn and away from the need to plant and nurture the ground, the idea of measured, equal time had its appeal. Instead of living life on nature's timeline, city dwellers arranged their lives on all abstract line, with points designated as hours and minutes. Jobs would begin at a specified point on the timeline, whether it was light or dark outside, Appointments would be fixed on this timeline, as would buying, selling, transporting, and distributing goods and services -- an artificial time based upon hours and minutes, regulated by the even, continuous flow of manmade time. ASTRONOMER-PRIESTS Ancient priests were the first to study the stars and the periodic phenomena that appeared in the heavens-eclipses, meteor showers, shooting stars and comets, for example -- because they thought that the heavenly bodies had an influence on the course of human affairs. With patient observation and a reliance on measured (or uniform) time, these early astronomers discovered that such mysterious events occurred at predictable times. Events that mystified and often frightened casual observers -- such as a total eclipse of the sun in broad daylight or a brilliant comet apparently headed directly for earth -- could be predicted in advance by astronomer-priests whose powers to (seemingly) control celestial mysteries had the desired effect on the ignorant populace. The astronomer-priests sought to create a calendar so that these heavenly events, along with the numerous journeys of planets and stars through the zodiac, could be calculated on the basis of a solar year. Not only did they know when certain astrological and astronomical events would occur but they could also find their own position in time within the solar year. The waxing and waning of the moon, from new moon through full moon to the beginning of the next new moon, takes a month -- almost. Actually, the moon's journey around the earth takes, on average, 29 1/2 days. It being almost 30 days, one would think that a year would have about 360 days in it. But the year is not the 12 revolutions of the moon around the earth. A year is one revolution of the earth around the sun, from the start of one season to the start of the next same season. OBSERVING TIME The day is our first measured unit of time, but there are various kinds of day, all based on one rotation of the earth with reference to some point outside the earth. This point may be the sun, an imaginary sun, a particular star or even an imaginary point in the sky. As an observer turns with the earth, he thinks of himself as an index mark, much like the mark on a sundial, and as the sun makes two successive passes over him at high noon, the time between the two passes is an apparent solar day Because the path of the earth around the sun is elliptical, and because the ellipse is tilted relative to the equator, these solar days vary throughout the year. If we were to put the earth in a circular path around an imaginary sun, then the solar days would all be equal to each other and would show uniform mean solar time , just as a good clock shows. Mean solar time (clock time) and apparent solar time (sundial time), however, vary with the season of the year. In the middle of April, the middle of June, the end of August, and around Christmas time, mean solar time and sundial time are equal. At the beginning of November a sundial is about 16 minutes ahead of clock time, but in the middle of February it is 14 minutes slower. The differences for every day in the year are tabulated in almanacs as the "equation of time." The variations in solar and lunar time as compared to equal or average solar time explain why we began using star time ( sidereal time) as a standard time reference. If an observer on earth notes the passage of a particular fixed star overhead at the same point on two successive nights, he will note that this passage is practically the same no matter what season of the year it is. A sidereal day is shorter than an average solar day (or clock day) by 3 minutes and 56 seconds. This adds up to 24 hours slower in a year. So there are 366 sidereal days compared with 365 ordinary solar days in a year. It was this sidereal day (23 hours, 56 minutes and 4.1 seconds long) that was considered the absolute time standard for centuries until the twentieth century, when mechanical clocks became so accurate that they could measure the wobble in the earth's rotation and the drifting of stars. Until then we had thought their movements were stable and unvarying. ASTRONOMICAL TIME Astronomers were far more interested in mean solar time and sidereal time than were ordinary people. The study of the heavens itself required an accurate time standard. The significance of all of this for ordinary people does not become apparent until they get to the point of living in communities and needing to use time to regulate every activity, not only in hours and minutes but to locate themselves within the year as well-a point that will become all too apparent as we follow the story of timekeeping. To the ancients -- and not-so-ancients -- the heavens were filled with mystery, superstition, mythology and magic when certain planets aligned with certain stars or constellations of stars. All had names and each was deemed to have power over humans on earth. It was the astronomer's job to follow these celestial events, to anticipate them and predict their eventual outcome, so that the kings, priests, emperors and ordinary citizens could appease their will and act accordingly. To this end the astronomer developed charts of the earth and the luminaries that surrounded it: the sun, the moon and the visible planets and stars. Astronomers developed hand-driven, three-dimensional models of their celestial charts, called armillary spheres , to add motion to their charts. With these they could study the relationships involved. The armillary sphere was an elegant machine with bands tracing out the paths of visible planets and stars, along with moving rings of horizons, ecliptics and imaginary reference points. With the earth inside the cage of rings, the cage rotated in the sphere of immovable bands, imitating the sky turning above us and showing how the heavens rise in the east and sink below the horizon in the west. Surrounding it all are the constellations seen throughout the year, appropriately inclined to the horizon ring so that an observer can understand the rising and setting points of the sun and moon during their paths and so understand how the seasons change. It was to the armillary sphere that astronomers sought to add a uniform power supply to operate this model of the celestial chart and give a continuously running model that would duplicate the movement of the heavens in real time, helping the communities to organize their activities. The armillary sphere was also the forerunner for the development of gears and springs. (See The Mysterious Antikythera, page 29.) CULTURAL TIME Long before the Europeans, a Chinese emperor commissioned such an armillary sphere at the turn of the eleventh century. His armillary not only reproduced the movements of the sun, moon and selected stars but also showed the hours, the quarter hours and night watches (periods of time during the night that the town guards watched over the security of the town) all powered by water and controlled by a large tower clepsydra. This was a true astronomical clock and an engineering marvel, not only in its day but predating any European astronomical clock by 400 years -- and nobody outside of China knew of it! Given this advance, one of the great curiosities of world technological development is why the mechanical clock was developed in Europe instead of China? After all, medieval China was technologically ahead of Europe in many areas: gunpowder, accurate water clocks, paper, movable type, porcelain, the magnetic compass and a true astronomical clock. But the mechanical clock -- a logical successor to the highly mechanized and complicated Chinese astronomical water clock -- did not materialize. Instead, it emerged 250 years later from the virtual scientific wasteland that Europe was during the thirteenth century. The answer, we will see, is in the cultures of the two societies. The ordinary Chinese did not need to know the time in order to know what had to be done. Natural daily rhythms were good enough. Only the imperial astronomers needed to know the time in order to study and predict the movements of the heavens. The life of the emperor and the rule of his government were regulated by the religious mythology of the stars. The clock was an adjunct to the armillary sphere, supplying power and control to the display of heavenly motion so that the government could govern and imperial fortunes and futures could be told. They did not need to know the time, only the motions of the heavens. In Europe, Christianity was the culture. As Professor David Landes noted in his unique work, Revolution in Time , "The Clock did not create an interest in time measurement; the interest in time measurement led to the invention of the (mechanical) Clock." And it was the Christian Church that had the real interest in time measurement and the ordering of people's lives. Excerpted from Timepieces: Masterpieces of Chronometry by David Christianson All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.

Table of Contents

Introduction -- The Celestial Clock
A Clock in the Heavens
Earthly Time
Sun Time and Clock Time
Observing Time
Astronomical Time
Cultural Time
Su Sung's Astronomical Clock (A.D. 1096)
Chapter 1 A Call to Prayer
Orderliness and Measured Time
Automating the Ringing Bell
Clockwork Gearing
Pope Sylvester II (A.D. c.945-1003)
When is a Clock Not A Clock?
The Community Clock
Ringing in the Renaissance
The De Dondi Astrarium (A.D. 1365)
The Mysterious Antikythera (c.86 B.C.)
Chapter 2 The Priceless Possessions of a Few
Patrons of Clockmaking
The Escapement
Demand from the Bourgeoise
The Stackfreed and Fusée
A New Dimension of Accuracy
Science and the Clockmaker
The Quest for Accuracy
The Clockmaker and the Scientist
Chapter 3 From Tabletop to Waistcoat and Beyond
The Watch-Production Scene
John Calvin's Influence on Fashion
Fashion Abhors a Bulge
The Fashion of the Church
Lépine and the Modern Watch
George Washington and Lépine
The Influence of Business
Time on Your Hands
Thinner is Better
Fashion Dictates Fashion
Chapter 4 The Craft Era in Watchmaking
The Watch
Passing on the Craft
Craft Guilds
The Geneva Rules of 1601 (Abridged)
The Bored-Ruby Jewel
... And Their Decline
The Cottage Industry
The Craft Era Continues
The Craft Era in the Quartz Age
Re-Enter the Mechanical
Abraham-Louis Breguet
The New Renaissance Watchmaker
The Quest for the Precision Watch Escapement
Chapter 5 The Industrial Revolution
Timing the Industrial Revolution
The American System of Manufacture
Eli Terry: The Industrial Revolution in a Nutshell
The Industrial Revolution of Watches
The Principles of the Watch
A New Craftsman Emerges
The American Method in Perspective
Invention's Debt to Watch- and Clockmaking
Chapter 6 A Mountain Industry Explodes
The Cabinotier
The Machine Age Comes to the Mountains
Vallée de Joux: The Heart and Soul of Swiss Watchmaking
Complicating Time
The Chronometer Time Trials
Miniaturizing the Complications
The Tiniest of Complications
Women in Watchmaking
The Complicated Watch
Chapter 7 The Standardization of Time
The Challenge of the Age
A King's Ransom for a Cure
One Man's Talents
... His Clocks
... His Obsession
Out of Chaos
Railroad Time
Train Wreck
Chapter 8 The Quartz Revolution
A New Revolution Brews
A New Definition of Time
The Electric Watch
They Became Accurate
And Then They Became Cheap
How the Mechanical Watch Works
Accuracy is No Longer an Issue
How the Electronic Watch Works
The Mechanical Watch in the Quartz Age
The Battery -- The Power Behind the Electric Watch
The Quartz Revolution and the Repair Technician
It's Hard to Love a Quartz Timepiece
Sources and Further Reading
Picture Credits and Acknowledgments