You will need:
- Large glass jar
- Balloon
- Rubber bands
- Chart paper, sketch pen
- Scissors & Fevicol
- Light weight drinking straw
- Pen and paper
Become the in-house weather man by predicting weather patterns by using a simple home-made barometer.
INSTRUCTIONS
- Take the straw and using your hands, flatten out 1 inch on only one end
of the straw. Using scissors cut the flattened part to look like a pointer.
Colour it with a sketch pen. - Cut a large piece off the balloon. Take this piece and stretch it across the
mouth of the glass jar. Secure it in place with the help of a rubber band. Make sure the balloon tightly seals the glass jar so that no air may go in or out. - Using a bit of fevicol attach the normal end of the straw to the balloon,
from the centre till the edge of the glass jar. At least 6 inches of the straw should extend out. - Place this contraption in an undisturbed part of the house.
- Take your chart paper, and draw a line marked NORMAL. Above the line, write HIGH and below it write LOW. Fix the chart paper behind the glass jar and straw in such a way that the pointy edge of the straw is on the NORMAL line.
- Note your observations for a few weeks.
RESULT
Depending on the change in weather conditions the home-made barometer will also move. If the air pressure is high, the pressure inside the glass jar will be lower and the outside pressure will force the balloon top downwards, making the straw go above the NORMAL line. And in case the air pressure is low, indicating cloudy weather which could result in rains or snow, then the air pressure inside the glass jar will be greater, making the balloon lid rise and the straw dip below the normal line.
