Galilean thermometer

• C+75+25

This thermometer has sealed glass bulbs with varying amounts of water and air inside of them floating within a container of ethanol. Since ethanol’s density changes fairly dramatically with response to temperature the balls will rise and fall accordingly as the temperature of the room changes. The one that is free-floating indicates the current temperature by means of an attached tag. A hairdryer and/or ice bath can be provided to show the motion of the bulbs due to temperature change.