1. The History of The Clocks CGULS 9209005 雷雅晴 9209016 羅庭芳 9209016 羅庭芳 9209029 楊雅君 9209029 楊雅君

2. The etymology --- origin of the word Clock Sundial Sundial Water Clocks Water Clocks Watches Watches Bell Bell Clocks Clocks

3. The origin of the word Clokke = Middle English Clokke = Middle English Clocca = Medieval Latin Clocca = Medieval Latin Cloc = Celtic and Old Irish Cloc = Celtic and Old Irish Clugge = Old English Clugge = Old English Glocka = Old High German Glocka = Old High German

4. The Sands of Time ( Sand Clock ) glass vessel which has two compartments glass vessel which has two compartments used by navies used by navies 1. as a timekeeper 1. as a timekeeper 2. to find the speed of the ship 2. to find the speed of the ship

5. Sundial --- Shadow Clock A vertical stick, gnomon, or obelisk that casts a shadow is a Sundial A vertical stick, gnomon, or obelisk that casts a shadow is a Sundial "The Equation of Time" "The Equation of Time" tell Apparent sun time, while your clock tells Mean Solar Time tell Apparent sun time, while your clock tells Mean Solar Time

6. ALARM CLOCK The Candle was used as an alarm clock by placing a nail into the wax, whenever the candle wax melted down to the nail, then the nail would fall into a tin pan and make a noise. The Candle was used as an alarm clock by placing a nail into the wax, whenever the candle wax melted down to the nail, then the nail would fall into a tin pan and make a noise.

7. The alarm typically had a cam that rotated every 12 hours. There was a notch into which a lever would fall, releasing a train of gears that engaged a hammer, which repeatedly hit a bell. The alarm typically had a cam that rotated every 12 hours. There was a notch into which a lever would fall, releasing a train of gears that engaged a hammer, which repeatedly hit a bell.

8. Pendulum Clock In 1583 Galileo demonstrated that successive beats of a pendulum always take place in the same length of time, regardless of the distance through which the "pendulum do swing". In 1583 Galileo demonstrated that successive beats of a pendulum always take place in the same length of time, regardless of the distance through which the "pendulum do swing". The wheel or ring that replaced the verge and foliot escapement is called a Balance Wheel. The wheel or ring that replaced the verge and foliot escapement is called a Balance Wheel. Huygen's design used a recoil escapement with an escape wheel and anchor with pallets called an Anchor Escapement. Huygen's design used a recoil escapement with an escape wheel and anchor with pallets called an Anchor Escapement.

9. The Pendulum has a natural frequency that is independent of amplitude and the frequency does not depend on the weight of the pendulum, only its length and the acceleration of gravity. The Pendulum has a natural frequency that is independent of amplitude and the frequency does not depend on the weight of the pendulum, only its length and the acceleration of gravity. George Grahamn of London, England in about 1720 modified the anchor escapement to eliminate recoil, creating the Deadbeat Escapement. George Grahamn of London, England in about 1720 modified the anchor escapement to eliminate recoil, creating the Deadbeat Escapement.

10. Electrical Clocks ------Battery Clocks In 1840 the first Battery clock used an electrical impulse to operate the dials of a centrally located master clock. In 1840 the first Battery clock used an electrical impulse to operate the dials of a centrally located master clock. in 1906 the first self contained battery driven clock was invented. in 1906 the first self contained battery driven clock was invented.

11. Electrical Clocks---- Synchronous Electric Motor Clock The synchronous electric motor came into use in 1918. The synchronous electric motor came into use in 1918. Patented by Henry Ellis Warren in 1916. Patented by Henry Ellis Warren in 1916.

12. Electrical Clocks------ Quartz Clocks The piezoelectric effect was discovered by the Curie brothers in 1880 The piezoelectric effect was discovered by the Curie brothers in 1880 The first Quartz Crystal was applied in a clock in 1929. This clock can have an accuracy of one second every 10 years. The first Quartz Crystal was applied in a clock in 1929. This clock can have an accuracy of one second every 10 years.