1. The Evolution of The Clock PowerPoint Created By Kevin Kubis and SidathWanigasinghe

3. The Sundial The sundial was created in 3500 BC and was the first instrument to measure time. It was also the oldest scientific device. The sun creates the shadow on the sundial that can be used to tell what time it is.

4. The Hourglass The was created some time in the 14th century. The sand falls through at a certain rate so people can be able to know how much time is passing. Different sized hourglasses are used for different amounts of time.

5. The Waterclock The water clock was created in 325 BC and one of the first clocks that was ever made. Water would drip down at a constant pace and collect at the bottom of a bowl that had markings on it to tell what time it was.

6. The First Spring Powered Clock The spring-powered clocks were invented in 1500. At the time it was a revelation because it was small and portable. It was a large improvement, but it still did not even have a minute hand.

7. The Pendulum Clock A pendulum clock uses a swinging pendulum to keep track of time. The pendulum clock was developed in 1656. This type of clock needs to be stationary in order to work properly because motion causes time inaccuracy.

8. Digital Clock The digital clock shows a numerical representation of the current time. It was developed in 1972 by a watch company named Hamilton. There are two display formats used for this kind of clock. 24 hour notation which range from 0-23 and 12 hour notation, with the AM and PM indicator.

9. Harmful Effects Some clocks are coated in radium, which is a radioactive chemical. This material can harm you if it comes into contact with your body.

10. The Manufacturing Process of a Clock

11. Sources Cited http://www.wisegeek.com/what-is-an-hourglass.htm http://www.chaddsfordhistory.org/history/clocks.htm http://en.wikipedia.org/wiki/Pendulum_clock http://wiki.answers.com/Q/The_history_of_digital_clock http://www.google.com/images?q=pendulum%20clock&rls=com.microsoft:en-us&oe=UTF-8&startIndex=&startPage=1&safe=active&um=1&ie=UTF-8&source=og&sa=N&hl=en&tab=wi&biw=1419&bih=690 http://answers.yahoo.com/question/index?qid=20091219141804AA43jR7 http://www.crunchgear.com/wp-content/pbucket/sonystyle.jpg http://www.bing.com/images/search?q=bedside+clock&form=QBIR&qs=n&sk=&sc=3-13&adlt=strict#focal=f1d9e439129a42cf60266fb95645af8a&furl=http%3A%2F%2Fwww.apartmenttherapy.com%2Fuimages%2Fchicago%2Fclockq031010.jpg http://gallery.riskaka.com/albums/album734/00859_radioactive_1920x1200.sized.jpg