Galileo Thermometers

Galileo's 400-year-old principle of relative density. You can simply read the tag on the lowest floating coloured bubble to see the temperature of the room.

The science behind the thermometer was discovered 400 years ago by Galileo - he found that specifically weighted floating bubbles would predictably rise or sink in a liquid as the temperature of the liquid changed. Each float within the glass case weighs just grams more than the one above it, and the tags on which temperature is marked are attached to them by hand to ensure accuracy.

Some thermometers have Fitzroy's storm glass. A mysterious phenomenon, the special combination of liquids inside the glass is able to predict changes in weather. Admiral Robert Fitzroy used an incredible storm glass like this whilst sailing during the 18th century, including as the captain of HMS Beagle during Charles Darwin's famous voyage.