The Fitzroy's Storm Glass is one of those unusual yet amazing little things that you happen to stumble across from time to time. Put simply, it is a fancy bit of science that will help you to accurately predict the kind of weather that is looming on the horizon!

While this may seem somewhat unbelievable, Fitzroy's Storm Glass is a historical weather forecasting device that was used by seafarers on the HMS Beagle in the 1800's to predict windy weather or thunderstorms at sea!

Composed of a fully sealed, 23cm hand-blown glass tube filled with liquid, you can now forecast the weather by observing the appearance of the liquid in the glass. When the temperature and pressure of the atmosphere change with different weather patterns, the water and crystals inside the glass change too!

This is based on the principle that temperature and pressure affect solubility, sometimes resulting in clear liquid, and other times causing precipitants to form. The liquid in the glass is a mixture of several ingredients including distilled water, ethanol, potassium nitrate, ammonium chloride and camphor.

Written on the side of your Storm Glass is a key to assist you:

Clear liquid = Fair weather
Murky Liquid = Rainy weather
Crystals at the top = Thunderstorms
Large flaky crystals = Cloudy skies, snow in winter
Thread of crystals = Windy weather

The perfect gift for someone who loves their barometer and loves to predict how the weather will turn out!