Se basa en las diferentes formas de cristalización de una disolución en función de la presión y temperatura.
The liquid within the glass is a mixture of several ingredients, most commonly
distilled water,
ethanol,
potassium nitrate,
ammonium chloride, and
camphor. This specific mixture was developed by Admiral
Robert FitzRoy and used on his voyage with
Charles Darwin on the
HMS Beagle.
[1]
During the historic voyage, FitzRoy carefully documented how the storm glass would predict the weather:
[2]
- If the liquid in the glass is clear, the weather will be bright and clear.
- If the liquid is cloudy, the weather will be cloudy as well, perhaps with precipitation.
- If there are small dots in the liquid, humid or foggy weather can be expected.
- A cloudy glass with small stars indicates thunderstorms.
- If the liquid contains small stars on sunny winter days, then snow is coming.
- If there are large flakes throughout the liquid, it will be overcast in temperate seasons or snowy in the winter.
- If there are crystals at the bottom, this indicates frost.
- If there are threads near the top, it will be windy.
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.
http://en.wikipedia.org/wiki/Storm_glass
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