Thompson, Benjamin, Count Rumford

Brown, S. C. (1976). Thompson, Benjamin (Count Rumford). In Dictionary of Scientific Biography, ed. C. C. Gillispie, Vol. 13, pp. 350-352. New York Scribner. Brown, S. C. (1979). Benjamin Thompson, Count Rumford. Cambridge, MA MIT Press. 

British physicist Benjamin Thompson (Count Rumford) shows that work is convertible into heat and vice versa. 

In 1801 Count Rumford (Benjamin Thompson) obtained for Davy a position as assistant lecturer on chemistry and director of the laboratory at the Royal Institution. In the Philosophical Magazine one finds the following description of Davy s first lecture, which was on galvanism ... 

The question at once arises as to how much work must be done to produce this much heat. This question was answered by experiments carried out in Manchester, England, between 1840 and 1878 by James Prescott Joule (1818-1889), after Count Rumford (Benjamin Thompson, 1753-1814, an American Tory) had shown in 1798 that the friction of a blunt borer in a cannon caused an increase in temperature of the cannon. Joule s work led to essentially the value now accepted for the mechanical equivalent of heat, that is, the relation between heat and work ... 

Humphry Davy was not only an exceptionally gifted scientist, he also had remarkable social talents, and it is typical of him that already as a young man his career was sponsored by such luminaries in British science as Sir Joseph Banks, Henry Cavendish and Benjamin Thompson (Count von Rumford). He was also a great communicator, who from an early age made a name for himself in the popularization of science. At the same time, he had an intuition in scientific matters that allowed him to select problems that would prove to be fruitful and important. His work on electrolysis using Alessandro Volta s newly invented pile is a good example of this. He was convinced that in electrolysis the current induced the separation of compounds into their elementary components rather than the synthesis of new substances, as many scientists believed at the time. 

JGeorge E. Ellis, Memoir of Sir Benjamin Thompson, Count Rumford, with Notices of his Daughter" (Boston, 1873). 

Mrs. Fulhame made two, probably three, great discoveries. She was the first to demonstrate photoimaging and used salts of gold and other metals. The famous Count Rumford (Benjamin Thompson—see pp 356-359) differed with her chemical interpretation as opposed to a purely physical one." He was wrong — the photochemical reduction of gold or silver ions to the respective metals is... 

Figure 222 is from the Philosophical Transactions of the Royal Society ofLon don by Benjamin Thompson (Count Rumford) (1753-1814). A solid iron pipe (Fig. 1), normally bored to make a cannon, was machined to leave a short cylinder (9.8 inches in length and 7.75 inches in diameter) attached by a thin... 

FIGURE 222. The cannon-boring experiment of Benjamin Thompson (Count Rumford), which disproved the caloric theory (from Phihsophical Transactions of the Royal Society of London, Vol. 88 (1798) pp. 80-102). 

After only three years at Bristol, Davy was invited to become Assistant Lecturer in chemistry at the Royal Institution in London. The Royal Institution had been founded by Benjamin Thompson, Count Rumford, who had been born In Massachusetts In 1753, but had fought on the British side in the War of Independence. After the war he came to Europe and entered the service of the elector of Bavaria as Minister for War, during which time he performed his famous cannon-boring experiments (Chapter 13). By 1798 he was in London canvassing the idea of an institution to teach the applications of science and to popularise recent inventions. There was to be a school for mechanics and an exhibition of modern domestic appliances. He obtained sufficient subscribers, and the Royal Institution was founded in 1799. 

The notion of heat as an indestructible substance was the essence of the caloric theory. This theory was finally disproved by the cannon-boring experiments of Benjamin Thompson (Count Rumford) in the late eighteenth century, and in a more quantitative way by the measurement of the mechanical equivalent of heat by James Joule in the 1840s (see Sec. 3.7.2). 

Professor Horsford, who held the Rumford Chair of the Application of Science to the Useful Arts (how about that for a title ) at Harvard, named his original product Rumford Baking Powder after Benjamin Thompson, Count Rumford, an important American-bom physicist in the late eighteenth century who was one of the first to maintain that heat is a form of motion. Rumford also played a major role in ensuring the success of the newly established Royal Institution of Great Britain. 

Count Rumford (Benjamin Thompson), Phil Trans., 88, 80 (1798). 

Benjamin Thompson, Count Rumford, 1753-1814, was an American-Brltlsh physicist who abandoned his family and left America after the American revolution because of his royalist sympathies. He pursued a checkered career in various countries, including Bavaria (where he ingratiated himself with the Elector of Bavaria), France (where he married Lavoisier s widow), and England (where he founded the Royal Institution and hired Humphrey Davy as a lecturer). 

Count Rumford, Benjamin Thompson (1753-1814). (Courtesy of the Chemical Heritage... 

The early notion that heat was a fluid called caloric was disproved in 1798 by Benjamin Thompson (later. Count Rumford). While minister of war in Bavaria and boring cannon, he observed that heat could be produced continuously and endlessly from a given mass of iron, and so it could not be a fluid. In one of his experiments, he used a team of two horses to turn a lathe that bored a hole in a 51-kg piece of cannon iron. The iron was immersed in a wooden box containing 18.77 lb. of water. The assembly was initially at 60.°F and 1.00 atm. 

Benjamin Thompson (North Woburn, Massachusetts, 26 March 1753-Auteuil, nr. Paris, 21 August 1814), a Royalist American, contemporary of Benjamin Franklin, was for a time in the service of the Elector Palatine of Bavaria, who in 1792 created him Count Rumford of the Holy Roman Empire. He is known for important researches on the nature of heat and as the founder of the Royal Institution in London. Rumford was especially interested in the economic production of heat, and invented several ingenious fire-places and stoves." He expressed doubts on the caloric theory in 1797. In Munich he noticed the large amount of heat evolved in the boring of cannon, and from experiments with a blunt borer in a cylinder of metal turned by horses he concluded that it is extremely difficult, if not quite impossible, to form any distinct idea of anything capable of being excited and communicated in the manner the heat was excited and communicated in these experiments except it be motion . Rumford published other important researches. ... 

The science of food is veiy old, dating back to at least the second century B.c. when observations were made on the density of meat. In the 1700s chemist Antoine Lavoisier, the father of modern chemistiy, did experiments on the preparation of meat stock. Benjamin Thompson (better known as Count Rumford) invented the double boiler and the percolating coffeepot. For the most part, early food science focused on preserving food by canning. Kurti made a presentation at the Royal Society of London in 1969 which began the change toward food as a science. Kurti said, I think it is a sad reflection on our civilization that while we can... 

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