Anders Celsius (1701–1744) invented the centigrade scale that bears his name, but in his original thermometer the boiling point of water was marked as and the freezing point as : exactly the opposite of how we use it today. It was only after his death that the scale was inverted into the form we know.
Before standardisation, the fixed points proposed by various thermometer makers included the melting point of butter, the temperature of deep caves, and even “the hottest water a hand held still can bear”. The disorder was such that in 1776 the Royal Society of London had to appoint a committee, chaired by Cavendish, to establish definitive reference points (Oxford Handbook 2014, pp. 473–474).
Curiosity
The choice of fixed points for a temperature scale has never been “obvious”: it is the outcome of a long negotiation between experimental practicality and reproducibility. Modern physics has since anchored the absolute scale (kelvin) to fundamental constants, making it independent of any particular substance.
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Topics: Teoria cinetica dei gas Concepts: Temperatura
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