The Admiral Fitzroy storm glass is an instrument which was proposed as a method for predicting weather. Especially popular after the admiral escaped from a storm when convoying Darwin in a world tour in 1836. It consisted of a special liquid placed inside a sealed transparent glass (mix of campher nitrate of potassium and alcool). The state of crystallization within the liquid was believed to be related to the weather. It might be of little value in weather prediction but definitely high as a curiosity!