Hourglasses

1. By: Angelica Lafayette Hourglasses

2. About the hourglass • Before the invention of digital clocks hourglasses was used to tell time. Hourglasses were made by Greeks and Romans, but only the book of history can tell the truth.

3. What is a hourglass? • A hourglass is a glass container which contains sand. There are two bulbs. The one on top has to hold the sand. Piece by piece the sand drops to the bottom, and when it’s done flip hourglass to start over.

4. The bulbs that the sand is in • The two bulbs were each blown separately with open throats. To join them so the sand would be allowed to flow from the top to the bottom ,the two halves were bonded together with a cord covered in wax.

5. The right sand • Sand found on beaches is attractive although it’s not the best for hourglass-making. For the simple fact that it is too angular and doesn’t flow smoothly. Marble dust , other rock dust and rock flour-powder from cutting glass-and round sand grains , like those of river sand are the best for sand clocks.

6. facts • The first hourglass was found in Europe. • Before the 14th century the hourglass were used in Italy. • The hourglass and clepsydra(or water clocks) have to follow the exact same principle.

7. facts • Sand clocks designs can also very considerably in size. • The smallest known hourglass are the size of a cufflink , and the largest are up to three feet (one meter) tall.

8. Sources • www.hourglass.com • www.theclockdepot.com • www.icr.org

9. questions • How are the hourglasses designed? • The smallest hourglass made is the size of what? • The largest hourglass is the height of what?

10. questions • The first hourglass was found where? • Before the 14th century hourglasses where used in where? • What is another name for a water clock is what? • The water glass and hourglass sure the same what?

11. Thank you !!!!!!! • Thanks for your time! • Thanks for watching this power point.         !!!!!!!!!!