Galileo Thermometer. This is a triangular built one, not too often seen. Will stand on its own. Great item for a desktop or office furnishing. This is based on an idea by Galileo Galilei (1564-1642)
How it works: This thermometer works on the principle discovered by Galileo that the density of a liquid changes as temperature varies. Each glass bal is exactly weighted by partially filling the spheres with liquid. When the temperature rises the liquid in the glass cylinder becomes less dense, and the heavier balls sink slowly to the bottom.
How to read: The lowest temperature ball within the group at the top of the cylinder tells the correct temperature. The lowest floating ball indicated the current temperature. If all the balls float to the top, the temperature is below the lowest floating ball. If all the balls sink, the temperature is above the highest ball.