Born a poor farm boy in Massachusetts, Benjamin Thompson managed to become an apprentice in Boston where, at the age of 13, he developed a keen interest in science. At 19 he wrote a paper on the physics of electricity; so impressive, he was asked to be the schoolmaster in Rumford, New Hampshire. A loyalist and spy for the British during the American Revolution, Thompson had to flee to England in fear of his life.
In England he made powerful friends as he continued his scientific studies. For his work in guns and explosives he was elected into the Royal Society. For his dedication and service fighting the Americians, he was knighted and became Sir Benjamin Thompson. He traveled to Europe, eventually making it to Germany, where he rapidly reached high position. Among many accomplishments, he invented a double boiler, a coffeepot, the first kitchen range, and introduced James Watt's steam engine into wide use. The Bavarians were very grateful and made him a count. He took the name Count von Rumford.
Count Rumford is mentioned in most chemistry and physics texts because of his study of heat. Doing research to improve the manufacture of heavy cannons, Rumford noticed that when cannon barrels are bored, a great deal of heat is produced. In the late 18th century, most scientists believed heat was a substance (Lavoisier had given it the name "caloric"). The Count realized that friction during the boring of the cannon barrels was the source of the heat, which could be continuously produced. He found that no loss of mass occured during the boring and eventually stated that heat is not a substance but related to motion.
In 1804, Thompson moved to Paris and was married to the widow of Antoine Lavoisier for a short time. Ironically Marie-Anne was the wife of both the scientist who established that heat was a substance called caloric and the scientist who later corrected the mistake.