This relatively rare thermometer has a rather unusual display: lower temperatures are located at the top of the scale, higher ones at the bottom. A sphere on a chain floats in a suitable liquid, sinking at high temperatures when the density of the liquid decreases and rising in the increased density at low temperatures. With reasonable effort and experimental dexterity, you can construct this thermometer yourself using ordinary materials.iopscience.org/ped 3 The Galileo thermometer is also known as Galilei thermometer according to the Italian scientist's surname. The principle of the Galileo thermometer is described on Wikipedia (https://en.wikipedia.org/wiki/Galileo_thermometer). A more quantitative explanation can be found in [1]. See also: www.youtube.com/watch?v=uziOSFjIbbE, Galileo Thermometer-Studying Buoyancy, Density and Temperature.4 See footnote 3. 5 The company's name is now Moeller-Therm. 6 The Taiwanese company River City Clocks offers a sort of Galileo chain thermometer in its assortment.