Mercury-in-glass thermometer ushered in a new era of accuracy and precision in thermometry, and is still to this day regarded as one of the most accurate thermometers available. The thermometer was used by the originators of the Fahrenheit and Celsius scales. Anders Celsius, a Swedish scientist, devised the Celsius scale, which was described in his publication "The origin of the Celsius temperature scale" in 1742. Celsius used two fixed points in his scale: the temperature of melting ice and the temperature of boiling water. This wasn't a new idea, since Isaac Newton was already working on something similar. The distinction of Celsius
Frog thermometer the spheres' sluggish motion, this thermometer was also called infingardo [slothful, slow]. The invention of this model is attributed to Ferdinand II de' Medici. Frog thermometer The frog thermometer or - as the Cimento academicians defined it, the "botticino" [small-toad] thermometer - contained small glass spheres of different density, which were immersed in alcohol. The device was used as a clinical thermometer, tied to the wrist or the arm of the patient with the head of the frog facing upward. The variations in body temperature were registered by the movement of the spheres. The rise in temperature causes an increase