Count Rumford was born Benjamin Thompson in America, in 1753. He made the mistake of supporting the British during the American War of Independence and so was forced to flee to England in 1776, after the British were defeated. But Thompson was very resourceful, and a social climber too. By 1798 he was minister for war and police in the German state of Bavaria. He was also made a Count of the Holy Roman Empire, choosing for himself the title 'Count Rumford'.
One of his early jobs was to oversee the boring of cannons in the state arsenal. Thompson was struck by the enormous, and apparently unlimited, amount of heat generated by the process. He used a giant water bath to measure the amount of heat you can get when boring the hole into a cannon barrel and obtained a rough value for the mechanical equivalent of heat. His experiments also showed that heat was not a substance as predicted by the then popular caloric theory but is related to motion.
In 1781 Thompson was made a Fellow of the Royal Society on the basis of a paper on the relationship between various gunpowders and the apparent force with which the cannon balls were shot. Count Rumford clearly had a deep interest in guns and other weapons, as his research frequently returned to them. In 1797 he produced a gunpowder standard.
A lifelong interest in heat also led him to develop an interest in the manufacture of military uniforms. He went on to study insulation and came to the conclusion that heat was lost mainly through convection; thus soldiers' clothing should be designed to prevent this.
Read Rumford's own account of his experiments. If you were a journalist who had to summarise the account into 150 words for a newspaper what would you leave out? Does that bias the report? What do you know about motion and heat? Did that affect how you edited the original account?
Thompson's non-military research included studies of nutrition, controlling smoke from open fires and chimneys, coffee as an alternative to alcoholic drinks, luminous intensity, complementary colours and photosynthesis. In 1799 Thompson was one of the founders of the Royal Institution.
Thompson clearly had both scientific curiosity and talent as an experimenter. Perhaps his focus on military research was a result of the troubled times through which he lived. In his situation, do you think that you would have suffered moral doubts about military work? Explain your answer.
Cooke and Wheatstone