Fitzroy Storm Glass.

Based on an instrument refined by Admiral Fitzroy (1805-1865)

History:-

The storm glass came into use in the early 1700's. Sailors attached the instrument to the mast of their ships and interpreted the changing crystal formations to forecast weather conditions at sea. 

Admiral Fitzroy, master of HMS Beagle during the famous Charles Darwin expedition of 1836 conducted a detailed study of the instrument and refined chemical formulation. 

How it works:-

How the storm glass works is a mystery but it is believed that electromagnetic changes associated with weather patterns activate the crystals.

How to read it :- 

Clear liquid = bright and clear weather.

Cloudy liquid = Cloudy weather and rain.

Small dots in liquid = Mist and fog.

Large flakey crystals = Cloud or snow.

Crystal threads at top = Wind.

Crystals at bottom = Frost is coming. 

Approx size:- 14cm high.