Predict the weather like the seafarers of old with the Weatherglass Barometer! This hand-blown glass bulb contains trapped air that expands and contracts with changes in atmospheric pressure, allowing the water inside to move up or down the spout accordingly. This hand blown glass bulb contains trapped air that expands and contracts with changes in atmospheric pressure.  When water moves up the spout, expect stormy conditions; when water moves down the spout, good weather is on its way.  Standing at approximately 15 cm (6 inches) tall, this barometer is a charming and functional addition to any home or office space. Join the ranks of the weather-wise with this timeless and simple forecasting device.. ~15 cm (6 inches) tall, includes syringe, tubing and instructions