Tips for Changing Water in a Stormglass Barometer

To fill a glass barometer, you will need a tub of cold water and a tub of hot water. For safety reasons, the hot water should NOT be too hot to touch. The barometer should first be placed in the cold water. This will cause air in the barometer to cool and contract.

The barometer should be removed from the cold water and placed in the hot water, with the spout submerged. As the gas expands, water will be pulled into the barometer. Repeat this process until there is enough water in the barometer to cover the bottom opening of the spout.

To empty water, the process should be reversed.