For these experiments you will need the kit listed on the contents page in your box. You will also need the following –
- Sticky tape
- A bottle
- Four cups
Using a compass
Make sure you have your compass to hand whilst Chemical Cress explains how your compass works and how it should be used –
Making your compass bracelet
Here is Chemical Cress to show you how to make your own compass bracelet –
Making a sundial
Throughout the day, the sun moves across the sky and makes different shadows. We can actually tell the time using a sundial which casts different shadows depending on the time of day. If you were in another country, your sundial would look a bit different!
- First, get your sundial template – it is a semi-circle with numbers on it and a triangle. The triangle on a sundial is known as a ‘gnomon’.
- You can colour your sundial to make it more interesting but use light colours or colouring pencils so that you can still see the shadows the sun makes.
- Cut out the semi-circle (base) and the triangle (gnomon) Use sticky tape to stick your gnomon onto your semi-circle so that it looks like this…PHOTO.
- Place your sundial on a flat surface in a sunny area (outside is best). Use your compass to find north and make sure the number 12 is pointing towards the north like this…PHOTO.
When it is sunny, look at the shadow that your gnomon casts onto your base. Does it show you the right time? Check with your watch and then turn your sundial until the time is correct. Wait a little while and check it later. Is the time right now? Watches are much more accurate than sundials but before clocks were invented, people had to use the sun to tell the time. It wasn’t always exactly right but it was close enough!
One reason your sundial may not be completely accurate is because we are currently in British Summer Time. The sun hasn’t changed position in the sky but we change our clocks so we can make the most of the sunny days. Fixed sundials, like those you may find in gardens, are actually an hour out during British summer time.
Using a flint and steel
*Adult supervision required* Do this outside!
Flint and steel were used to light fires before we had things like matches and lighters. Some people still use them for lighting camp fires and as a survival tool, when they may not have access to matches or lighters.
Flint and steel works by striking flint (a hard piece of stone) against steel. This creates sparks which can be used to light wood and create a campfire.
Magnetic Maggie is going to show you how to use a flint and steel. It is really important to never create sparks towards someone, or towards something that could easily catch fire.
Do you know the difference between water in the oceans and water in rivers? Water in the oceans is salty! We call water in rivers and lakes fresh water. But is the water actually ‘fresh’? Although it is called fresh water, we can’t drink it like we do from a tap. This is because it can contain lots of bacteria from wildlife and contaminents like sticks and mud that can make us sick. You are going to do an experiment to try and clean some water using natural methods.
You will need your funnel, and a bottle and four cups.
- Fill one bottle half full with water and add soil to make it dirty, like water you might find in a pond or stream.
- Put your funnel in your empty cup.
- First of all you are just going to pour the water straight through the funnel into a cup. This is called your ‘control’ because this is what you will compare your other results to.
- Next, measure out half of your “dirty” water into a cup so that you have two samples.
- For your first sample, put your filter paper into the funnel and pour the sample through into an empty cup. How clean does the water look?
- Next, find something natural to use as a filter, this could be stones, grass, leaves or anything you think would make a good filter!
- Put your natural filter into the funnel and pour your next sample through into another empty cup.
- How does the water look?
- Which sample looks the cleanest? What could you do to make it cleaner?
Remember! Even though the water may look clean you should NOT drink it. Filters won’t filter out microscopic things like bacteria. If you were in the wilderness, and this was your only way to get fresh water, you should filter it 2 or 3 times AND boil it. Boiling it will kill bacteria and germs that don’t get filtered out.