Galileo Thermometer

A Galileo Thermometer named after Italian physicist Galileo Galilei is a thermometer made of a sealed glass cylinder containing a clear liquid and sealed glass bulbs with weights attached. As the liquid changes temperature, its density changes and the bulbs rise or fall to a position where their density is either equal to that of the surrounding liquid or where they are brought to a halt by other bulbs. If the bulbs differ in density by a very small amount and are ordered such that the least dense is at the top and the densest at the bottom, they form a temperature scale, hence the Galileo Thermometer.

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