Principle
In this experiment, the students observe the cooling of two wet thermometers in the air. One of the thermometers is soaked in water, the other in methylated spirit. They notice that a wet thermometer cools down even further in the air and that there is a clear difference between the cooling caused by the evaporation of water and the evaporation of alcohol. From this they conclude that the strength of the cooling during evaporation depends on the liquid used.