A beautiful weather forecasting device developed by Admiral Robert FitzRoy and used on his voyage with Charles Darwin. The liquid inside crystallises spectacularly in response to changes in temperature.
The Fitzroy Storm Glass is a sealed glass container filled with a liquid which responds to changes in the weather, which was designed to allow the observer to forecast the possibility of storms, snow, wind, rain or clear skies. While it was later found to only react to current temperature rather than be an effective tool for forecasting the weather, its visually beautiful changes make the storm glass an extremely attractive and conversational room ornament.
This specific mixture was developed by Admiral Robert FitzRoy and was used on his voyage with Charles Darwin on the HMS Beagle. FitzRoy documented the use of his storm glass as a tool for measuring the weather, claiming that:
In 1859, violent storms struck the British Isles. In response, the British Crown distributed storm glasses, then known as "FitzRoy's storm barometers," to many small fishing communities around the British Isles that were to be consulted by ships at port before setting sail.