Barometers: Weather Ball
What is a Weather Ball?
The Weather Ball Barometer, another variation of the barometer, indicates changes in air pressure quickly and accurately. The readings are based on the amount of water in the spout; when the weather is good, the water level is low, while a high-water level in the spout forecasts rainy or windy weather.
How does the Weather Ball work?
The glass ball is filled with coloured water. Once filled, the air trapped inside the ball is no longer subject to variations in atmospheric pressure, but the the spout remains open and is directly affected by atmospheric pressure. When atmospheric pressure rises, the liquid is pushed down in the tube, indicating clear weather. During bad weather, the low air pressure can't push through the tube as well and so the liquid rises higher in the tube as the weather worsens.
