Galilean Thermometer

I got this Galilean thermometer a few years ago for Christmas. I don't ever really use it, but I thought it was pretty. The glass bubbles are filled with different colored water, and each glass bubble represents a temperature. Based on which ones float or sink due to the change in water density, it tells you what the temperature is. I'm not sure it works properly, though, as the temperature reading on this one says it's 66°F or 19°C in this room, and it definitely feels much colder than that.