The Galileo Thermometer is named after an idea Galileo Galilei had, a great scientist who lived over 350 years ago.
Galileo cleverly discovered a method for measuring temperature by placing several precisely weighted balls in a cylinder filled with a certain fluid.
He found that the balls rose or fell according to the current temperature, therefore he was able to determine the correct temperature.
Based on the principle that the density of a liquid changes as temperature varies, each of the glass balls is individually weighted by partially filling the spheres with fluid.
When the temperature rises, the liquid in the cylinder becomes less dense and the heavier balls fall slowly to the bottom.
This 56cm tall Galileo Thermometer contains 11 colourful, carefully weighted balls of hand-blown glass and a temperature range of 16C and 36C.
Watch the temperature change by seeing the balls rise and fall as their densities change.
