These unique and decorative glasses react to the weather in a mysterious way and have been used on ships since the 1750s. It was even used by Charles Darwin to predict the weather when he was on his way to the Galápagos Islands. The crystals will change shape depending on the actual weather. When the crystals are visible, humid and foggy weather could be expected. A cloudy glass with small crystals would tell Charles Darwin a thunderstorm is on its way and clear glass will mean clear weather. So these decorative glasses will react to atmospheric changes. The Storm Glasses come in 3 different shapes, the Large & Small drops and the Globe. They all have their own beautiful unique packaging that would look great on your shelves. The drops are placed on a nice wooden plateau and can be placed anywhere. The Storm Glasses work best when they are placed near a window and have it settled for 2 weeks. Keep in mind that this very nice ornament is not always a 100% accurate barometer, but neither is the weatherman!