How to Construct a Sand Clock

Today we just glance at a digital clock if we want to tell the time, but telling time was not always that easy. Long ago people had to use what was around them to tell time such as the sun, moon or stars. People even created their own clocks out of sand. This experiment will give students a better understanding of time and how it was calculated before the technology age. Follow these simple steps to create your very own sand clock.

Things You'll Need

• 1 gallon plastic milk container
• 1 2-liter plastic soda container
• Sand
• Piece of mesh screen
• Piece of cork
• Bucket
• Funnel
• Utility knife
• Drill
• Stop watch

Instructions

1. Cut the cork to fit the 2-liter soda bottle. You may have to shape it with your utility knife so that it fits. Once you have the cork sized you need to drill a hole through the middle of the cork. The hole must go all the way to the other side. This is a step that should be performed by an adult.

2. Collect some sand in a cup. Place the mesh screen over the top of the cup and sift out the sand into a bucket. This is going to take several cups, but it is important that all the sand gets sifted. If the sand isn't sifted it could get stuck in the cork which would ruin the experiment.

3. Pour the sifted sand through a funnel into the 2-liter bottle. If you do not have a funnel you can make one out of a sheet of paper. Just roll the paper up in a diagonal pattern until you only have a small hole at the bottom. Tape it in place and put the small hole into the 2-liter bottle. Fill the 2-liter bottle all the way up with sand.

4. Plug the 2-liter bottle up with the piece of fitted cork.

5. Place the 2-liter bottle upside down so that the other end of the cork goes in to the gallon milk jug. Immediately start your stopwatch.

6. Stop your stopwatch as soon as the sand runs out. However many minutes have passed, that is is your time increment for your sand clock. So every time you turn the jug over, that same amount of minutes will have elapsed.

Tips & Warnings

• Make sure your sand and plastic containers are completely dry before using them.

• Never allow a child to use a utility knife. This could result in unnecessary accidental injury.