Speaker 1: Welcome to the I Can't Sleep Podcast, where I help
Speaker 1: you drift off one fact at a time. I'm your host,
Speaker 1: Benjamin Boster, and today's episode is about clocks. A clock
Speaker 1: or chronometer is a device that measures and displays time.
Speaker 1: The clock is one of the oldest human inventions, meeting
Speaker 1: the need to measure intervals of time shorter than the
Speaker 1: natural units, such as the day, the lunar month, and
Speaker 1: the year. Devices operating on several physical processes have been
Speaker 1: used over the millennia. Some predecessors to the modern clock
Speaker 1: may be considered clocks that are based on movement in nature.
Speaker 1: A sun dials shows the time by displaying the position
Speaker 1: of a shadow on a flat surface. There is a
Speaker 1: range of duration timers, a well known example being the hourglass.
Speaker 1: Water clocks, along with sun dials, are possibly the oldest
Speaker 1: time measuring instruments. A major advance occurred with the invention
Speaker 1: of the verge escapement, which made possible the first mechanical
Speaker 1: clocks around thirteen hundred in Europe, which kept time with
Speaker 1: oscillating time keepers like balance wheels. Traditionally, in orology the
Speaker 1: study of time keeping, the term clock was used for
Speaker 1: a striking clock, while a clock that did not strike
Speaker 1: the hours audibly was called a timepiece. This distinction is
Speaker 1: not generally made any longer. Watches and other time pieces
Speaker 1: that can be carried in one's person are usually not
Speaker 1: referred to as clocks. Spring driven clocks appeared during the
Speaker 1: fifteenth century. During the fifteenth and sixteen centuries, clock making flourished.
Speaker 1: The next development and accuracy occurred after sixteen fifty six
Speaker 1: was the invention of the pendulum clock by Christian Huggins.
Speaker 1: A major stimulus to improving the accuracy and reliability of
Speaker 1: clocks was the importance of precise timekeeping for navigation. The
Speaker 1: mechanism of a timepiece with aories of gears driven by
Speaker 1: a spring or weights is referred to as clockwork. The
Speaker 1: term is used for a similar mechanism not used in
Speaker 1: a timepiece. The electric clock was patented in eighteen forty,
Speaker 1: and electronic clocks were introduced in the twentieth century, becoming
Speaker 1: widespread with a development of small battery powered semiconductor devices.
Speaker 1: The time keeping element in every modern clock is a
Speaker 1: harmonic oscillator, a physical object resonator that vibrates or oscillates
Speaker 1: at a particular frequency. This object can be a pendulum,
Speaker 1: a balance wheel, a tuning fork, a quartz crystal, or
Speaker 1: the vibration of electrons and atoms as they emit microwaves,
Speaker 1: the last of which is so precise that it serves
Speaker 1: as the formal definition of the second. Clocks have different
Speaker 1: ways of displaying the time. Analog clocks indicate time with
Speaker 1: a traditional clock face and moving hands. Digital clocks display
Speaker 1: a numeric representation of time. Two numbering systems are in use,
Speaker 1: twelve hour time notation and twenty four hour notation. Most
Speaker 1: digital clocks use electronic mechanisms in LCD, LED and VFD
Speaker 1: displays for the blind and for use over telephones, Speaking
Speaker 1: clocks state the time audibly in words. There are also
Speaker 1: clocks for the blind that have displays that can be
Speaker 1: read by touch. The word clock derives from the medieval
Speaker 1: Latin word for bell, clocca, and has cognates in many
Speaker 1: European languages. Clocks spread to England from the Low Countries,
Speaker 1: so the English word came from the Middle Low German
Speaker 1: and Middle Dutch clocca. The word is also derived from
Speaker 1: the Middle English clock, Old North French clock, or Middle
Speaker 1: Dutch clocca, all of which mean bell. The apparent position
Speaker 1: of the sun and the sky changes over the course
Speaker 1: of each day, reflecting the rotation of the earth. Shadows
Speaker 1: cast by stationary objects move correspondingly, so their positions can
Speaker 1: be used to indicate the time of day. A sundial
Speaker 1: shows the time by displaying the position of a shadow
Speaker 1: on a usually flat surface that as markings that correspond
Speaker 1: to the hours. Sun dials can be horizontal, vertical, or
Speaker 1: in other orientations. Sun dials were widely used in ancient times.
Speaker 1: With knowledge of latitude, a well constructed sun dial can
Speaker 1: measure local solar time with reasonable accuracy within a minute
Speaker 1: or two. Sun dials continued to be used to monitor
Speaker 1: the performance of clocks in Dily eighteen thirties. When the
Speaker 1: use of the telegraph and trains standardize time and time
Speaker 1: zones between cities, many devices can be used to mark
Speaker 1: the passage of time without respect or reference time time
Speaker 1: of day, hours, minutes, et cetera, and can be useful
Speaker 1: for measuring duration or intervals. Examples of such duration timers
Speaker 1: are candle clocks, incense clocks, and the hourglass. Both the
Speaker 1: candle clock and the incense clock work on the same
Speaker 1: principle wherein the consumption of resources is more or less constant,
Speaker 1: allowing reasonably precise and repeatable estimates of time passages. In
Speaker 1: the hour glass, fine sand pouring through a tiny hole
Speaker 1: at a constant rate indicates an arbitrary predetermined passage of time.
Speaker 1: The resource is not consumed but reused. Water clocks, along
Speaker 1: with sun dials, are possibly the oldest time measuring instruments,
Speaker 1: with the only exception being the day counting tally stick.
Speaker 1: Given their great antiquity, where and when they first exist
Speaker 1: it is not known and is perhaps unknowable. The bowl
Speaker 1: shaped outflow is the simplest form of a water clock
Speaker 1: and is known to have existed in Babylon and Egypt
Speaker 1: around the sixteenth century b C. Other regions of the world,
Speaker 1: including India and China, also have early evidence of water clocks,
Speaker 1: but the earliest dates are less certain. Some authors, however,
Speaker 1: write about water clocks appearing as early as four thousand
Speaker 1: b C in these regions of the world. The Macedonian
Speaker 1: estroemer Andronicos of Cyrus supervised the construction of the Tower
Speaker 1: of the Winds and Assens in the first century BC,
Speaker 1: which housed a large klepsidra inside, as well as multiple
Speaker 1: prominent sundials outside, allowing it to function as a kind
Speaker 1: of early clock tower. The Greek and Roman civilizations advanced
Speaker 1: water clock design with improved accuracy. These advances were passed
Speaker 1: on through Byzantine and Islamic times, eventually making their way
Speaker 1: back to Europe independently. The Chinese developed their own advanced
Speaker 1: water clocks by seven twenty five AD, passing their ideas
Speaker 1: on to Korea and Japan. Some water clock designs were
Speaker 1: developed independently, and some knowledge was trans insferred through the
Speaker 1: spread of trade. Pre modern societies do not have the
Speaker 1: same precise time keeping requirements that exist in modern industrial societies,
Speaker 1: where every hour of work or rest is monitored and
Speaker 1: work may start or finish at any time regardless of
Speaker 1: external conditions. Instead, water clocks in ancient societies were used
Speaker 1: mainly for astrological reasons. These early water clocks were calibrated
Speaker 1: with a sun dial. While never reaching the level of
Speaker 1: accuracy of a modern time piece, the water clock was
Speaker 1: the most accurate and commonly used time keeping device for
Speaker 1: millennia until it was replaced by the more accurate pendulum
Speaker 1: clock in seventeenth century Europe. Islamic civilization is credited with
Speaker 1: further advancing the accuracy of clocks through elaborate engineering. In
Speaker 1: seven ninety seven or possibly eight o one, the Abbasid
Speaker 1: Caliph of Baghdad arun Rashid presented Charlemagne with an Asian
Speaker 1: elephant named abul Abbas, together with a particularly elaborate example
Speaker 1: of a water clock. Pope Sylvester the Second introduced clocks
Speaker 1: to northern and western Europe around one thousand eighty. The
Speaker 1: first known geared clock was invented by the great mathematician, physicist,
Speaker 1: and engineer Archimedes during the third century BC. Archimedes created
Speaker 1: his astronomical clock, which was also a cuckoo clock, with
Speaker 1: birds singing and moving every hour. It is the first
Speaker 1: carolon clock as it plays music simultaneously with a person
Speaker 1: blinking his eyes surprised by the singing birds. The Archimedes
Speaker 1: clock works with a system of four weights, counterweights, and
Speaker 1: strings regulated by a system of floats, and a water
Speaker 1: container with siphons that regulate the automatic continuation of the clock.
Speaker 1: The principles of this type of clock are described by
Speaker 1: the mathematician and physicist Hero who says that some of
Speaker 1: them work with a chain that turns a gear in
Speaker 1: the mechanism. Another Greek clock, probably constructed at the time
Speaker 1: of Alexander, was in Gaza. As described by A Procopius,
Speaker 1: the Gaza clock was probably a medious kopaean by e
Speaker 1: a building showing celestial phenomena and the time. It had
Speaker 1: a pointer for the time and some automations similar to
Speaker 1: the Archimedes clock. There were twelve doors opening, one every
Speaker 1: hour with Hercules performing his labors the lion at nine o'clock,
Speaker 1: et cetera. And at night a lamp becomes visible every
Speaker 1: hour with twelve windows opening to show the time. The
Speaker 1: Tang dynasty Buddhist Mung Yeshen, along with government official Leon Lingzhang,
Speaker 1: made the escapement in seven twenty three or seven twenty
Speaker 1: five to the workings of a water powered armillary sphere
Speaker 1: and clock drive, which was the world's first clockwork escapement.
Speaker 1: The Song dynasty polymath and genius Sioux Song incorporated it
Speaker 1: into his monumental innovation of the astronomical clock tower of
Speaker 1: Chaifung in ten eighty eight. His astronomical clock and rotating
Speaker 1: armillary sphere still relied on the use of either flowing
Speaker 1: water during the spring, summer, and autumn seasons or liquid
Speaker 1: mercury during the freezing temperatures of winter. In Sioux Song's
Speaker 1: water wheel link work device, the action of the escapement's
Speaker 1: arrest and release was achieved by gravity exerted periodically as
Speaker 1: a continuous flow of liquid filled containers of a limited
Speaker 1: size in a single line of evolution. Sioux Song's clock
Speaker 1: therefore unit the concepts of the calypsidra and the mechanical
Speaker 1: clock into one device run by mechanics and hydraulics. In
Speaker 1: his memorial, Siue's Song wrote about this concept, according to
Speaker 1: your servant's opinion, there have been many systems and designs
Speaker 1: for astronomical instruments during past dynasties, all differing from one
Speaker 1: another in minor respects, but the principle of the use
Speaker 1: of water power for the driving mechanism has always been
Speaker 1: the same. The heavens move without ceasing, but so also
Speaker 1: does water flow and fall. Thus, if the water is
Speaker 1: made to pour with perfect evenness, and the comparison of
Speaker 1: the rotary movements of the heavens and the machine will
Speaker 1: show no discrepancy or contradiction, for the unresting follows. The
Speaker 1: unceasing Song was also strongly influenced by the earlier armillary
Speaker 1: sphere created by Jong Seishun nine seventy six a d
Speaker 1: who also employed the escapement mechanism and used liquid mercury
Speaker 1: instead of water in the water wheel of his astronomical
Speaker 1: clock tower. The mechanical clockworks of Sioux's Song's astronomical tower
Speaker 1: featured a great driving wheel that was eleven feet in diameter,
Speaker 1: carrying thirty six scoobes, into each of which water was
Speaker 1: poured at a uniform rate from the constant level tank.
Speaker 1: The main driving shaft of iron, with its cylindrical necks
Speaker 1: supported on iron crescent shaped bearings, ended in a pinion
Speaker 1: which engaged a gear wheel at the lower end of
Speaker 1: the main vertical transmission shaft. The great astronomical hydro mechanical
Speaker 1: clock tower was about ten meters high, featured a clock escapement,
Speaker 1: and was indirectly powered by a rotating wheel, either with
Speaker 1: falling water or liquid mercury. A full sized working replica
Speaker 1: of Siusong's clock exists in the Republic of China National
Speaker 1: Museum of Natural Science, Taichung City. The full scale, fully
Speaker 1: functional replica, approximately twelve meters in height, was constructed from
Speaker 1: Siusong's original descriptions and mechanical drawings. The Chinese escapement spread
Speaker 1: west and was a source for Western escapement technology. In
Speaker 1: the twelfth century, al Jazarre, an engineer from Mesopotamia who
Speaker 1: worked for the artuct King of Dia Bacher nasier Aldine,
Speaker 1: made numerous clocks of all shapes and sizes. The most
Speaker 1: reputed clocks include the elephant scribe and castle clocks, some
Speaker 1: of which have been successfully reconstructed. As well as telling
Speaker 1: the time, these grand clocks were symbols of the status,
Speaker 1: grandeur and wealth of the Urtuk state. Knowledge of these
Speaker 1: mercury escapements may have spread through Europe with translations of
Speaker 1: Arabic and Spanish texts. The word horologgia was used to
Speaker 1: describe early mechanical clocks, but the use of this word
Speaker 1: for all time keepers conceals the true nature of the mechanisms.
Speaker 1: For example, there is a record that in eleven seventy six,
Speaker 1: Song Cathedral in France installed an orolodge, but the mechanism
Speaker 1: used is unknown. According to Jocelyn de Bracolon, in eleven
Speaker 1: ninety eight, during a fire at the abbey of Saint Edmundsbury,
Speaker 1: the monks ran to the clock to fetch water. Indicating
Speaker 1: that their water clock had a reservoir large enough to
Speaker 1: help extinguish the occasional fire. The word clock, which gradually
Speaker 1: supersedes ourolodge, suggests that it was the sound of bells
Speaker 1: that also characterized the prototype mechanical clocks that appeared during
Speaker 1: the thirteenth century in Europe. In Europe between twelve eighty
Speaker 1: and thirteen twenty, there was an increase in the number
Speaker 1: of references to clocks and horo lodges and church records,
Speaker 1: and this probably indicates that a new type of clock
Speaker 1: mechanism has been devised. Existing clock mechanisms that used water
Speaker 1: power were being adapted to take their driving power from
Speaker 1: falling weights. This power was controlled by some form of
Speaker 1: oscillating mechanism, probably derived from existing bell ringing or alarm devices.
Speaker 1: This controlled release of power the escapement marks the beginning
Speaker 1: of the true mechanical clock, which differed from the previously
Speaker 1: mentioned cog wheel clocks. The verge escapement mechanism appeared during
Speaker 1: the surge of true mechanical clock development, which did not
Speaker 1: need any kind of fluid power like water or mercury
Speaker 1: to work. These mechanical clocks were intended for two main
Speaker 1: purposes for signaling a notification and for modeling the solar system.
Speaker 1: The former purpose is administrative. The latter arises naturally given
Speaker 1: the scholarly interests in astronomy, science and astrology, and now
Speaker 1: these subjects integrated with the religious philosophy of the time.
Speaker 1: The astrolabe was used both by astronomers and astrologers, and
Speaker 1: it was natural to apply a clockwork drive to the
Speaker 1: rotating plate to produce a working model of the solar system.
Speaker 1: Simple clocks, intended mainly for notification, were installed in towers
Speaker 1: and did not always require faces or hands. They would
Speaker 1: have announced the canonical hours or intervals between set times
Speaker 1: of prayer. Canonical hours varied in length as the times
Speaker 1: of sunrise and sunset shifted. The more sophisticated astronomical clocks
Speaker 1: would have had moving dials or hands, and would have
Speaker 1: shown the time in various time systems, including Italian hours,
Speaker 1: canonical hours, and time as measured by astronomers at the time.
Speaker 1: Both styles of clocks started acquiring extravagant features such as automata.
Speaker 1: In twelve eighty three, a large clock was installed at
Speaker 1: Dunstable Priory in Bedfordshire in southern England. Its location above
Speaker 1: the rude screen suggests that it was not a water clock.
Speaker 1: In twelve ninety two Canterbury Cathedral installed a great horloge.
Speaker 1: Over the next thirty years there were mentions of clocks
Speaker 1: at a number of ecclesiastical institutions in England, Italy and France.
Speaker 1: In thirteen twenty two, a new clock was installed in Norwich,
Speaker 1: an expensive replacement for an earlier clock installed in twelve
Speaker 1: seventy three. This had a large two meter astronomical dial
Speaker 1: with automata and bells. The costs of the installation included
Speaker 1: the full time employment of two clock keepers for two years.
Speaker 1: An elaborate water clock, the cosmic engine, was invented by
Speaker 1: Sious Song, a Chinese polymath, designed and constructed in China
Speaker 1: and ninety two. This great astronomical hydromechanical clock tower was
Speaker 1: about ten meters high and was indirectly powered by a
Speaker 1: rotating wheel with falling water and liquid mercury, which turned
Speaker 1: an armillary sphere capable of calculating complex astronomical problems. In
Speaker 1: Europe there were the clocks constructed by Richard of Wallingford
Speaker 1: and Albans by thirteen thirty six and by Giovanni de
Speaker 1: Dundi and Padua from thirteen forty eight to thirteen sixty four.
Speaker 1: They no longer exist, but detailed descriptions of their design
Speaker 1: and construction survive, and modern reproductions have been made. They
Speaker 1: illustrate how quickly the theory of the mechanical clock had
Speaker 1: been translated into practical constructions, and also that one of
Speaker 1: the many impulses to their development had been the desire
Speaker 1: of astronomers to investigate celestial phenomena. The Australium of Giovanni
Speaker 1: Dondi de lo Lorojo was a complex astronomical clock built
Speaker 1: between thirteen forty eight and thirteen sixty four in Padua,
Speaker 1: Italy by the doctor and clockmaker Giovanni don de de
Speaker 1: lo Rogo. The Australium had seven faces and one hundred
Speaker 1: in seven moving gears. It showed the positions of the Sun,
Speaker 1: the Moon, and the five planets then known, as well
Speaker 1: as religious feast days. The Australium stood about one meter
Speaker 1: high and consisted of a seven sided brass or iron
Speaker 1: framework resting on seven decorative paw shaped feet. The lower
Speaker 1: section provided a twenty four hour dial and a large
Speaker 1: calendar drum showing the fixed feasts of the church, the
Speaker 1: movable feasts, and the position in the zodiac of the
Speaker 1: moon's ascending node. The upper section contained seven dials, each
Speaker 1: about thirty centimeters in diameter, showing the positional data from
Speaker 1: the primum mobile Venus, Mercury, the Moon, Saturn, Jupiter, and Mars.
Speaker 1: Directly above the twenty four hour dial is the dial
Speaker 1: of the Premium mobile, so called because it reproduces the
Speaker 1: diurnal motion of the stars and the annual motion of
Speaker 1: the Sun against the background of stars. Each of the
Speaker 1: planetary dials used complex clockwork to produce reasonably accurate models
Speaker 1: of the planet's motion. These agreed reasonably well both with
Speaker 1: ptolemaic theory and with observations. Wallingford's clock had a large
Speaker 1: astrolabe type dial showing the Sun, the Moon's age phase
Speaker 1: and node, a star map, and possibly the planets. In addition,
Speaker 1: it had a wheel of fortune and an indicator of
Speaker 1: the state of the tide. At London Bridge, bells rang
Speaker 1: every hour, the number of strokes indicating the time. Dundee's
Speaker 1: clock was a seven sighted construction one meter high, with
Speaker 1: dials showing the time of day, including minutes, the motions
Speaker 1: of all the known planets, an automatic calendar of fixed
Speaker 1: and movable feasts, and an eclipse prediction hand rotating once
Speaker 1: every eighteen years. It is not known how accurate or
Speaker 1: reliable these clocks would have been. They were probably adjusted
Speaker 1: manually every day to compensate for errors caused by wear
Speaker 1: and imprecise manufacture. Water clocks are sometimes still used and
Speaker 1: can be examined in places such as ancient castles and museums.
Speaker 1: The Salisbury Cathedral clock, built in thirteen eighty six, is
Speaker 1: considered to be the world's oldest surviving mechanical clock that
Speaker 1: strikes the hours. Clockmakers developed their art in various ways.
Speaker 1: Building smaller clocks was a technical challenge, as was improving
Speaker 1: accurate and reliability. Clocks could be impressive show pieces to
Speaker 1: demonstrate skilled craftsmanship, or less expensive, mass produced items for
Speaker 1: domestic use. The escapement, in particular, was an important factor
Speaker 1: affecting the clock's accuracy, so many different mechanisms were tried.
Speaker 1: Spring driven clocks appeared during the fifteenth century, although they
Speaker 1: are often erroneously credited to Nuremberg watchmaker Peter Henline around
Speaker 1: fifteen eleven. The earliest existing spring driven clock is the
Speaker 1: Chamber clock, given to Phillip the Good Duke of Burgundy
Speaker 1: around fourteen thirty, now in the Germinitious National Museum. Spring
Speaker 1: power presented clockmakers with a new problem, how to keep
Speaker 1: the clock movement running at a constant rate as the
Speaker 1: spring ran down. This resulted in the invention of the stack,
Speaker 1: freed and the fuse in the fifteenth century, and many
Speaker 1: other innovations down to the invention of the modern going
Speaker 1: barrel in seventeen sixty. Early clock dials did not indicate
Speaker 1: minutes and seconds. A clock with a dial indicating minutes
Speaker 1: was illustrated in a fourteen seventy five manuscript by Paulus Almanus,
Speaker 1: and some fifteenth century clocks in Germany indicated minutes and seconds.
Speaker 1: An early record of a second's hand on a clock
Speaker 1: dates back to about fifteen sixty, on a clock now
Speaker 1: in the Fremers Dworff collection. During the fifteenth and sixteen centuries,
Speaker 1: clock making flourished, particularly in the metal working towns of
Speaker 1: Nuremberg and Augsburg and in Blois, France. Some of the
Speaker 1: more basic table clocks have only one time keeping hand
Speaker 1: was a dial between the hour markers being divided into
Speaker 1: four equal parts, making the clocks readable to the nearest
Speaker 1: fifteen minutes. Other clocks were exhibitions of craftsmanship and skill,
Speaker 1: incorporating astronomical indicators and musical movements. The cross speed escapement
Speaker 1: was invented in fifteen eighty four by Joste Berghe, who
Speaker 1: also developed the Remintoir. Berghie's clock, was a great improvement
Speaker 1: and accuracy, as they were correct to within a minute
Speaker 1: a day. These clocks held the sixteenth century astronomer Tycho
Speaker 1: Brahi to observe astronomical events with much greater precision than before.
Speaker 1: The British had dominated watch manufacture for much of the
Speaker 1: seventeenth and eighteen centuries, but maintained a system of production
Speaker 1: that was geared towards high quality products for the elite.
Speaker 1: Although there was an attempt to modernize clock manufacture with
Speaker 1: mass production techniques and the application of duplicating tools and
Speaker 1: machinery by the British Watch Company in eighteen forty three,
Speaker 1: it was in the United States that this system took off.
Speaker 1: In eighteen sixteen, Eli Terry and some other Connecticut clockmakers
Speaker 1: developed a way of mass producing clocks by using interchangeable parts.
Speaker 1: Aaron Lufkin Denison started a factory in eighteen fifty one
Speaker 1: in Massachuset that also used interchangeable parts, and by eighteen
Speaker 1: sixty one was running a successful enterprise incorporated as the
Speaker 1: Waltham Watch Company,