TFA multi-coloured Galileo liquid thermometer with silver-coloured tags. Made of glass, after the idea of Galileo Galilei. Measuring range 18 to 26 degree C. Graduation 1 degree C, 7 balls. Measures 50 mm diameter by 438 mm height. In liquid, a solid body with the same weight and size is compelled to go down as the temperature rises. On the other hand the solid body goes up if the temperature falls. The glass balls differ in weight (calibrated to a hundredth of gram) and considering the density of the liquid, the lowest of the floating balls in the upper part of the cylinder indicates the right temperature.