4. Clock
An instrument used to indicate time
Device for measuring and displaying time
One of the oldest human inventions
Not always display time but it may also used to control a
device according to time.
5. Clock
SUNDIAL B.C. 742
oldest device
the sun casting a shadow onto
a cylindrical stone.
it can only tell time when the
sun is shining.
6.
7. Clock
CLEPSYDRAE 1400 BC
Water clock
Invented by the Egyptians
Used during at night and
cloudy days
The amount of water that
flowed into and out of a
device.
8. Clock
SANDGLASS A.D. 330
Hourglass
Fine sand pours through tiny
hole at a constant rate.
Indicates a predetermined
passage of an arbitrary period
9.
10. Clock
Candle and Stick of
Incense
A.D. 885
It burned down at
approximately predictable
speeds to estimate the passing
time.
Alfred the great used candles
as clocks.
11.
12. ClockYear Divided into
Months and Days
Greeks who worked on a
system taken from the ancient
Babylonians and Egyptians.
13. Clock
Dividing the day into
hours and seconds
Babylonians and Greeks
divided the day into 12 hours
of each light and dark. (Equinox
days)
Hipparchus with Greek
astronomers used Sumerial
sexagesimal system. The
astronomical calculation was a
base of 60.
14. Clock
Astronomical Clock Tower A.D.1020-1101
Song Dynasty Horologist and
Engr. Su Song
It was driven by a large
waterwheel, chaindrive and
escapement mechanism
15. Clock
Mercury Clock A.D. 1277
First mercury powered
automata clock
It was described in the Libros
del Saber
Invented by Ibn Khalaf al-
Muradi (Muslim)
16. Clock
A.D. 1283
A large clock was installed at
Dunstable Priory.
It was not a water clock
18. Clock
‘ 2 METRE ’ A.D. 1322
It was installed in Norwich
This had a large ‘ 2 metre’
astronomical dial with
automata and bells.
19. Clock
Richard Wallingford’s Clock A.D. 1336
It had a large astrolabe-type
dial, showing the sun, the
moon’s age, phase, and node, a
star map.
It had a wheel of fortune and
an indicator of the state of the
tide at the London Bridge.
The bell rang every hour.
20. Clock
Dondi’s Clock A.D. 1348-1364
Giovanni de Dondi
It was a seven-sided
construction, 1 metre high with
dials showing the time of day,
including min.,motion of
planets, an automatic calendar
of fixed and movable feasts
and a n eclipse prediction hand
rotating once every 18 years.
21. Clock
“Horologia” , “ Horologe” A.D. 1368
Greek word
It was the sound of bells of the
mechanical clocks
Clockmaking in England
started.
23. Clock
Spring-driven clock A.D. 1430
It is the chamber clock given to
Peter the Good, Duke of
Burgundy
It is now placed in
Germanisches National
Museum.
24. Clock
Clock Dials A.D. 1475
Early clock dials did not
indicate minutes and seconds.
A clock with a dial indicating
minutes was illustrated in a
manuscript by Paulus Almanus.
25. Clock
‘ Second Hand’ A.D. 1560
A second hand clock was
placed in the Fremersdorf
Collection.
However, this clock could not
have been accurate. It was
probably for indicating that he
clock was working.
26. Clock
Mechanical weight-driven
astronomical clock
A.D. 1556-1559
It is a mechanical weight-driven
astronomical clock with a
verge-and-foliot escapement, a
striking train of gears, an alarm,
and a representation of the
moon’s phases.
Ottoman Engr. Taqi al-Din
27. Clock
‘ Three Dials’ A.D. 1577-1580
It is an observational clock for
the Istanbul observatory of
Taqi al-Din
“ A mechanical clock with three
dials which shows the hours,
the minutes, and the seconds.”
28. Clock
Bürgi’s Clock A.D. 1584
The cross-beat escapement
was invented by Jost Bürgi,
who also developed the
remontoire.
It was a great improvement in
accuracy as they were correct
to within a minute a day.
29. Clock
A.D. 1581
An Italian Atronomer and
Physicist, Galileo, discovered
the properties of the Pendulum
31. Clock
Pendulum-driven clock A.D. 1657
Christiaan Huygens, Dutch
Physicist, who made the first
controlled pendulum clock.
He determined the
mathematical formula that
related pendulum length to
time (99.38 cm or 39.13 ‘’ for
the one second movement.
32. Clock
Pendulum Suspension Spring A.D. 1670 - 1
It is introduced by the English
clockmaker, William Clement.
Within just one generation,
minute hands and then second
hands were added.
33. Clock
H5 A.D. 1761
It doesn't contain pendulum.
It could determine longitude
accurately
John Harrison
His H5 clock was in error by
less than 5 seconds over 10
weeks.
35. Clock
1840-1841
Alexander Bain, Scottish
clockmaker
He was the first patented the
electromagnetic pendulum.
The clocks were working with
external batteries.
36. Clock
United States 19th century
Clocks were one of the first
items to be mass produced and
also to use interchangeable
parts.
The clock has batteries inside.
37. Clock
Quartz Crystal Clock A.D. 1970
Quartz Crystal is a rock that
looks like a glass.
An electronic oscillator is used
and regulated by the quartz
crystal to keep time.
It is more accurate than the
mechanical clocks
It has been the popular clocks
used in timekeeping
technology.
39. Clock
Talking clock 20th century
For convenience, distance,
telephony or blindness,
auditory clocks present the
time as sounds.
Sound : Spoken natural
language or as auditory codes.
40. Clock
Projection Clock 20th century
Some digital clocks include an
optical projector that shines a
magnified image of the time
display onto a screen or onto a
surface.
41. Clock
Tactile Clocks 20th century
These are clocks for the blind
that have displays that can be
read by using the sense of
touch.
A device using Braille code to
show the digits so they can be
felt with the fingertips.
42. CLOCK
Time line of Clock
BC AD
742 : Sundial 330 : Sandglass
1400 : Clepsydrea 885 : Candle & Stick of Incense
