WiseAcres Art Globe Barometer Glass
It will predict barometric weather changes by observing the rise and fall of liquid in the storm glass. All you have to do is to add colored distilled water and it is ready to go. The instructions are included. You can use it free standing on it's own, or you can also work it into a project with a wood base and so on but not required. Reading The Instrument: Variations in barometric pressure are immediately indicated by the level of water in the spout. A low water level in the spout suggests "high pressure", representing fair weather. A high water level in the spout suggests "low pressure" and forecasts poor weather conditions. In cases of severe weather (or major storms), the water may even run out of the spout. How it works: There is "weight" associated with the high and low-pressure systems which bring about changes in the weather. When the storm glass is filled with water, air pressure in the main chamber is trapped and held constant. Any changes in the atmospheric pressure are visible by the rising or falling level of water in the spout. While the storm glass will not indicate exact barometric pressure in numerical values, it is still regarded as an accurate monitor of air pressure changes. Such changes can be visible on a smaller scale, as the instrument is sensitive enough to measure pressure changes between the attic and basement of a three-story house.