Re: When was Newton's Law of Cooling discovered?

hi Tim,

Your question brought back horrible memories for me. When I was studying for my undergraduate biochemistry degree we had a practical class to study Newton's law of cooling, which involved measuring the temperature of an aluminium block wrapped in a tea-towel at regular intervals for 3 hours. The law itself is pretty straightforward: it states that the rate at which an object cools is proportional to the difference in temperature between the object and its surroundings. Usually I think that a practical demonstration is good but in this case, we all felt that we could have simply plotted a graph and saved ourselves 3 very boring hours!

Enough of that and on to your question. It's often quite difficult to know exactly when a discovery is made. Most scientific discoveries are announced after several years of work, so we take the date of the announcement (i.e. publication of the work as an article in a journal) as the date of the discovery.

Newton published his law of cooling in a journal called "Philosophical Transactions" which is now called Philosophical Transactions of the Royal Society of London. He published the article anonymously in Latin - it was entitled "Scala Graduum Caloris. Calorum Descriptiones & Figna" and appears in Volume 22, pages 824-829 in the year 1701. So I'm not surprised that you had difficulty in tracking it down. If you are interested, here is the reference, but you won't be able to read the full article without a subscription to the journal (and of course a good knowledge of Latin).

While I was researching your answer, I discovered another article, written in 1963 by James A. Ruffner, in a journal called "Archive for History of Exact Sciences" and entitled "Reinterpretation of the genesis of Newton's Law of Cooling". Huffner writes:

Now, most assuredly, NEWTON did not regard his generalization about the rate at which bodies lose heat as an empirical law, but there is little or nothing in the literature of the history or logic of science to suggest how the law was established, what its logical status was, or what factors surrounded its "discovery". Moreover, the dates proposed for the conception of this generalization are almost certainly wrong.

Reference: Ruffner JA. "Reinterpretation of the genesis of Newton's Law of Cooling" Archive for History of Exact Sciences 1963, vol 2, 138-153.