Thunder glass barometer

This cast iron thunder glass (what a fantastic name that is) is a real heirloom piece. All generations can enjoy it, whether green fingered or not. It’s a simple barometer with a design that’s been used since the 17th century to observe and forecast the weather.

The glass vessel comes with a cast iron base, a syringe to fill it with water and a blue pigment for colouring. Once set up you can watch the water level to give you a heads-up about conditions outside.

High atmospheric pressure (ie on sunny days) forces the water down the spout and raises the level in the main compartment. When pressure is low on rainy or cloudy days, the spout water rises. You’ll see the most dramatic change when a storm is near. Water can reach the top of the spout and start to drip. A useful warning - especially if you’ve just pegged out the washing!