Originating in the 17th century, the Galileo Thermometer is a precursor to the modern mercury thermometer and an elegant yet still practical piece of history. It is a sealed glass cylinder that contains clear liquid and glass bulbs that are all different density. As the temperature changes, the balls rise and fall, giving you a temperature reading.

The temperature is read from the engraved metal discs that hang off each bulb – if a bulb is floating in the middle, that is the current temperature, or if some are at the top and some at the bottom the temperature will between the bulbs on either side of the gap.

This Galileo Thermometer is 56cm tall with 11 glass balls (temperature range 16°C to 34°C).