Measure the air pressure and wow your friends with your weather forecast skills by making this home made Barometer.
Blow up a balloon to stretch it.
Cut the balloon in half.
Throw away the half of the balloon that has the air hole.
Stretch the rest of the balloon over a jar.
Secure the balloon tightly with an elastic band.
Attach a straw onto the top of the jar with some sticky tape.
Fix a sewing pin onto the end of the straw with some sticky tape.
Decorate a paper plate or piece of card with the sun on the top and the clouds on the bottom and make a stand for it using a paper cup.
Align the pin with the paper plate and make a mark on the plate where they meet. This is your base line.
HOW DOES IT WORK?