Watch
A watch is a portable timepiece intended to be carried or worn by a person. It is designed to keep a consistent
movement despite the motions caused by the person's activities. A wristwatch is designed to be worn around
the wrist, attached by a watch strap or other type of bracelet, including metal bands, leather straps or any other kind
of bracelet. A pocket watch is designed for a person to carry in a pocket, often attached to a chain.
History Of Watches
The history of watches began in 16th-century Europe, where watches evolved from portable spring-driven clocks,
which first appeared in the 15th century.
The watch was made by inventors and engineers developed from the 16th century to the mid-20th century was a
mechanical device, powered by winding a mainspring which turned gears and then moved the hands; it kept time
with a rotating balance wheel. In the 1960s the invention of the quartz watch which ran on electricity and kept time
with a vibrating quartz crystal, proved a radical departure for the watchmaking industry
Origins
Watches evolved from portable spring-driven clocks, which first appeared
in 15th-century Europe. Watches were not widely worn in pockets until the
17th century. One account suggests that the word "watch" came from the
Old English word woecce - which meant "watchman" - because town
watchmen used the technology to keep track of their shifts at work.[14]
Another says that the term came from 17th-century sailors, who used the
new mechanisms to time the length of their shipboard watches (duty
shifts).
The earliest dated watch known, from
1530
Evolution
A great leap forward in accuracy occurred in 1657 with the addition of the
balance spring to the balance wheel, an invention disputed both at the
time and ever since between Robert Hooke and Christiaan Huygens. This
innovation increased watches' accuracy enormously, reducing error from
perhaps several hours per day to perhaps 10 minutes per day,[18] resulting
in the addition of the minute hand to the face from around 1680 in Britain Drawing of one of his first balance
and around 1700 in France. springs, attached to a balance wheel,
by Christiaan Huygens, published in his
The increased accuracy of the balance wheel focused attention on errors letter in the Journal des Sçavants of 25
caused by other parts of the movement, igniting a two-century wave of February 1675. The application of
watchmaking innovation. The first thing to be improved was the the spiral balance spring (spiral
hairspring) for watches ushered in a new
escapement.
era of accuracy for portable timekeepers,
The verge escapement was replaced in quality watches by the cylinder similar to that which the pendulum had
introduced for clocks in 1656
escapement, invented by Thomas Tompion in 1695 and further developed
by George Graham in the 1720s although finishing and assembling was still done by hand until well into the 19th
century.
Wristwatches
The concept of the wristwatch goes back to the production of the very
earliest watches in the 16th century. In 1571 Elizabeth I of England received
a wristwatch, described as an "armed watch", from Robert Dudley. The
oldest surviving wristwatch (then described as a "bracelet watch") is one
made in 1806 and given to Joséphine de Beauharnais. From the beginning,
wristwatches were almost exclusively worn by women - men used pocket
watches up until the early-20th century. The first wristwatch is believed to
be made by the watch-maker Abraham-Louis Breguet in the year 1810 and
sold to the Queen of Naples on 5 December 1811 and the first Swiss
wristwatch was made by the Swiss watch-maker Patek Philippe, in the year
1868 for Countess Koscowicz of Hungary.
Military men first wore wristwatches towards the end of the 19th century,
having increasingly recognized the importance of synchronizing maneuvers
during war without potentially revealing plans to the enemy through
signaling. The Garstin Company of London patented a "Watch Wristlet"
design in 1893, but probably produced similar designs from the 1880s. Early wristwatch by Waltham, worn by
Officers in the British Army began using wristwatches during colonial
soldiers in World War I (German Clock
military campaigns in the 1880s, such as during the Anglo-Burma War of
1885. Museum).
Electric watches.
The Elgin National Watch Company and the Hamilton Watch Company
pioneered the first electric watch. The first electric movements used a
battery as a power source to oscillate the balance wheel. During the 1950s
Elgin developed the model 725 while Hamilton released two models: the
The Ventura was the world's first electric
first, the Hamilton 500, released on 3 January 1957, was produced into watch, powered by a battery, which was
1959. This model had problems with the contact wires misaligning, and the the product of over ten years' worth of
watches returned to Hamilton for alignment. The Hamilton 505, an research and development by Hamilton.
improvement on the 500, proved more reliable: the contact wires were
removed and a non-adjustable contact on the balance assembly delivered
the power to the balance wheel. Similar designs from many other watch
companies followed. Another type of electric watch was developed.
Quartz watches
The commercial introduction of the quartz Watch in 1969 in the form of the
Seiko Astron 35SQ and in 1970 in the form of the Omega Beta 21 was a
revolutionary improvement in watch technology in place of a balance
Seiko were the first brand to introduce a
wheel which oscillated at perhaps 5 or 6 beats per second, these devices
quartz watch into the market. The
used a quartz-crystal resonator which vibrated at 8,192 Hz, driven by a
limited edition. Seiko Astron was
battery-powered oscillator circuit. Most quartz-watch oscillators now released on December 25th, in Tokyo.
operate at 32,768 Hz, although quartz movements have been designed with frequencies as high as 262 kHz. Since the
1980s, more quartz watches than mechanical ones have been marketed.
Movement
Compared to electronic movements, mechanical watches are less accurate,
often with errors of seconds per day, and they are sensitive to position,
temperature and magnetism They are also costly to produce, require
regular maintenance and adjustments, and are more prone to failures.
Nevertheless, the craftsmanship of mechanical watches still attracts
interest from part of the watch-buying public, especially among the watch
collectors. Skeleton watches are designed to leave the mechanism visible Different kinds of movements move the
for aesthetic purposes. A mechanical movement uses an escapement hands differently as shown in this 2-
mechanism to control and limit the unwinding and winding parts of a second exposure. The left watch has
spring, converting what would otherwise be a simple unwinding into a a 24-hour analog dial with a
controlled and periodic energy release. A mechanical movement also uses
mechanical 1/6 s movement, the right
a balance wheel together with the balance spring (also known as a
one has a more common 12-hour dial
hairspring) to control the motion of the gear system of the watch in a
manner analogous to the pendulum of a pendulum clock. and a "1 s" quartz movement
Automatic watches
A self-winding or automatic watch is one that rewinds the mainspring of a
mechanical movement by the natural motions of the wearer's body. The
first self-winding mechanism was invented for pocket watches in 1770 by
Abraham-Louis Perrelet,[40] but the first "self-winding", or "automatic",
wristwatch was the invention of a British watch repairer named John
Harwood in 1923. This type of watch winds itself without requiring any
special action by the wearer. It uses an eccentric weight, called a winding Automatic watch: An eccentric weight,
rotor, which rotates with the movement of the wearer's wrist. The back- called a rotor, swings with the
and-forth motion of the winding rotor couples to a ratchet to wind the movement of the wearer's body and
mainspring automatically. Self-winding watches usually can also be wound
winds the spring
manually to keep them running when not worn or if the wearer's wrist
motions are inadequate to keep the watch wound.
Analog Watches
raditionally, watches have displayed the time in analog form, with a
numbered dial upon which are mounted at least a rotating hour hand and
a longer, rotating minute hand. Many watches also incorporate a third
hand that shows the current second of the current minute. In quartz
watches this second hand typically snaps to the next marker every second. Poljot chronograph
In mechanical watches, the second hand may appear to glide continuously,
though in fact it merely moves in smaller steps, typically one-fifth to one-
tenth of a second, corresponding to the beat (half period) of the balance
wheel.
Casio AE12 LCA (liquid-crystal-
analog) watch
Tactile
Tissot, a Swiss luxury watchmaker, makes the Silen-T wristwatch with a touch-sensitive face that vibrates to help the
user to tell time eyes-free. The bezel of the watch features raised bumps at each hour mark; after briefly touching the
face of the watch, the wearer runs a finger around the bezel clockwise. When the finger reaches the bump indicating the
hour, the watch vibrates continuously, and when the finger reaches the bump indicating the minute, the watch vibrates
intermittently
Digital Watches
A digital display shows the time as a number, e.g., 12:08 instead of a
shorthand pointing towards the number 12 and a long hand 8/60 of the way
around the dial. The digits are usually shown as a seven-segment display. The
first digital mechanical pocket watches appeared in the late 19th century. In
the 1920s, the first digital mechanical wristwatches appeared. The first digital
electronic watch, a Pulsar LED prototype in 1970, was developed jointly by
Hamilton Watch Company and Electro-Data, founded by George H. Thiess.
John Bergey, the head of Hamilton's Pulsar division, said that he was inspired
to make a digital timepiece by the then-futuristic digital clock that Hamilton
themselves made for the 1968 science fiction film 2001: A Space Odyssey. On
4 April 1972, the Pulsar was finally ready, made in an 18-carat gold case and
A Casio DBA-800 databank watch
sold for $2,100. It had a red light-emitting diode (LED) display.
with phone dialling capabilities.
Circa 1987
Illuminated Watches
Many watches have displays that are illuminated, so they can be used in
darkness. Various methods have been used to achieve this.
Mechanical watches often have luminous paint on their hands and hour
marks. In the mid-20th century, radioactive material was often An illuminated watch face, using a
incorporated in the paint, so it would continue to glow without any
luminous compound
exposure to light. Radium was often used but produced small amounts of
radiation outside the watch that might have been hazardous.[64] Tritium
was used as a replacement, since the radiation it produces has such low
energy that it cannot penetrate a watch glass. However, tritium is
expensive—it has to be made in a nuclear reactor—and it has a half-life of
only about 12 years so the paint remains luminous for only a few years.
Nowadays, tritium is used in specialized watches, e.g., for military
purposes (See Tritium illumination). For other purposes, luminous paint is
sometimes used on analog displays, but no radioactive material is
contained in it. This means that the display glows soon after being Digital LCD wristwatch Timex
exposed to light and quickly fades.
Ironman with electroluminescent
backlighting
Space Watches
The zero-gravity environment and other extreme conditions encountered by
astronauts in space require the use of specially tested watches.
The first-ever watch to be sent into space was a Russian "Pobeda" watch from the
Petrodvorets Watch Factory. It was sent on a single orbit flight on the spaceship
Korabl-Sputnik 4 on 9 March 1961. The watch had been attached without
authorisation to the wrist of Chernuchka, a dog that successfully did exactly the
The Omega Speedmaster, same trip as Yuri Gagarin, with exactly the same rocket and equipment, just a month
selected by NASA for use on
before Gagarin's flight. On 12 April 1961, Yuri Gagarin wore a Shturmanskie (a
space missions in the 1960s.
transliteration of Штурманские which actually means "navigator's") wristwatch
during his historic first flight into space. The Shturmanskie was manufactured at the
First Moscow Factory. Since 1964, the watches of the First Moscow Factory have been marked by the trademark
"Полёт", transliterated as "POLJOT", which means "flight" in Russian and is a tribute to the many space trips its watches
have accomplished.
Scuba Diving Watches
Watches may be crafted to become water-resistant. These watches are
sometimes called diving watches when they are suitable for scuba diving or
saturation diving. The International Organization for Standardization issued
a standard for water-resistant watches which also prohibits the term
"waterproof" to be used with watches, which many countries have
adopted.
Water-resistance is achieved by the gaskets which forms a watertight seal,
used in conjunction with a sealant applied on the case to help keep water
out. The material of the case must also be tested in order to pass as water-
resistant.
Seiko 7002–7020 Diver's 200 m on a 4-
ring NATO style strap
Navigation Watches
here is a traditional method by which an analog watch can be used to locate north and south. The Sun appears to move
in the sky over a 24-hour period while the hour hand of a 12-hour clock face takes twelve hours to complete one
rotation. In the northern hemisphere, if the watch is rotated so that the hour hand points toward the Sun, the point
halfway between the hour hand and 12 o'clock will indicate south. For this method to work in the southern hemisphere,
the 12 is pointed toward the Sun and the point halfway between the hour hand and 12 o'clock will indicate north. During
daylight saving time, the same method can be employed using 1 o'clock instead of 12. This method is accurate enough
to be used only at fairly high latitudes.
Smart Watch
A smartwatch is a wearable computer in the form of a
watch; modern smartwatches provide a local touchscreen
interface for daily use, while an associated smartphone app
provides for management and telemetry (such as long-term
biomonitoring). While early models could perform basic
tasks, such as calculations, digital time telling, translations,
and game-playing, 2010s smartwatches have more general
functionality closer to smartphones, including mobile apps,
a mobile operating system and Wifi /Bluetooth
connectivity. Some smartwatches function as portable
media players, with FM radio and playback of digital audio A person wearing a contemporary smartwatch (Apple
and video files via a Bluetooth headset. Some models, Watch)
called watch phones (or vice versa), have mobile cellular
functionality like making calls.
