The cooling law and the search for a good temperature scale, from Newton to Dalton

The research on the cooling law has begun with a Newton’s article published in 1701. Later, many studies were performed by other scientists confirming or confuting Newton’s law. The present paper presents a description and an interpretation of the Newton’s article, provides a short overview of the research on the topic performed during the 18th century, and discusses the relationships between the research on cooling laws and the definition of a temperature scale, as it was treated in the Newton’s article and in the work of Dalton, including the Dalton’s search for the absolute zero of temperature. It is shown that these scientists considered the exponential cooling law as a fundamental principle rather than a conjecture to be tested by means of experiments. The faith in the simplicity of natural laws and the spontaneous idea of proportionality between cause and effect seem to have strongly influenced Newton and Dalton. The topic is developed in a way which can be suitable both for undergraduate student and general physicist.