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People Behind the Science

Count Rumford (Benjamin Th ompson) (1753–1814)

ount Rumford was a U.S.-born in open fires and chimneys, such as the
Cphysicist who first demonstrated smoke shelf and damper. His search for an
conclusively that heat is not a fluid but a alternative to alcoholic drinks led to the
form of motion. He was born Benjamin promotion of coffee and the design of the
Thompson in Woburn, Massachusetts, first percolator.
on March 26, 1753. At the age of 19, he The work for which Rumford is best
became a schoolmaster as a result of much remembered took place in 1798. As mili-
self-instruction and some help from local tary commander for the elector of Bavaria,
clergy. He moved to Rumford (now named he was concerned with the manufacture of
Concord), New Hampshire, and almost cannons. These were bored from blocks of
immediately married a wealthy widow iron with drills, and it was believed that
many years his senior. the cannons became hot because as the
Thompson’s first activities seem to drills cut into the iron, heat was escaping
have been political. When the War of Inde- in the form of a fluid called caloric. How-
pendence broke out, he remained loyal to decided that soups would fit his require- ever, Rumford noticed that heat produc-
the British crown and acted as some sort ments. He devised many recipes and devel- tion increased as the drills became blunter
of secret agent. Because of these activities, oped cheap food emphasizing the potato. and cut less into the metal. If a very blunt
he had to flee to London in 1776 (having Soldiers were employed in gardening to drill was used, no metal was removed,
separated from his wife the year before). He produce the vegetables. Rumford’s enter- yet the heat output appeared to be limit-
was rewarded with government work and prise of manufacturing military uniforms less. Clearly, heat could not be a fluid in
an appointment as a lieutenant colonel in a led to a study of insulation and to the con- the metal but must be related to the work
British regiment. clusion that heat was lost mainly through done in turning the drill. Rumford also
In 1791, Thompson was made a count convection. Therefore, he designed cloth- studied the expansion of liquids of differ-
of the Holy Roman Empire in recogni- ing to inhibit convection—sort of the first ent densities and different specific heats,
tion of civil administration work he did in thermal clothing. and showed by careful weighing that the
Bavaria. He took his title from Rumford in No application of heat technology expansion was not due to caloric taking up
his homeland, and it is by this name that we was too humble for Rumford’s experi- the extra space.
know him today—Count Rumford. ments. He devised the domestic range— Rumford’s contribution to science in
Rumford’s early work in Bavaria com- the “fire in a box”—and special utensils to demolishing the caloric theory of heat was
bined social experiments with his lifelong go with it. In the interest of fuel efficiency, very important, because it paved the way to
interests concerning heat in all its aspects. he devised a calorimeter to compare the the realization that heat is related to energy
When he employed beggars from the streets heats of combustion of various fuels. and work, and that all forms of energy can
to manufacture military uniforms, he faced Smoky fireplaces also drew his attention, be converted to heat. However, it took sev-
the problem of feeding them. A study of and after a study of the various air move- eral decades to establish the understanding
nutrition led him to recognize the impor- ments, he produced designs incorporating that caloric does not exist and there was no
tance of water and vegetables, and Rumford all the features now considered essential basis for the caloric theory of heat.

Source: Modified from the Hutchinson Dictionary of Scientific Biography. © Research Machines plc 2003. All Rights Reserved. Helicon Publishing is a division of Research Machines.

order), for example, when a heat pump cools and condenses should therefore approach a limit of maximum disorder
the random, chaotically moving water vapor molecules into called the heat death of the universe. Th e heat death of the
the more ordered state of liquid water. When the energy source universe is the theoretical limit of disorder, with all mole-
for the production, transmission, and use of electrical energy is cules spread far, far apart, vibrating slowly with a uniform
considered, however, the total entropy will be seen as increas- low temperature.
ing. Likewise, the total entropy increases during the growth of The heat death of the universe seems to be a logical con-

a plant or animal. When all the food, waste products, and prod- sequence of the second law of thermodynamics, but scientists
ucts of metabolism are considered, there is again an increase in are not certain if the second law should apply to the whole
total entropy. universe. What do you think? Will the universe with all its
Th us, the natural process is for a state of order to degrade complexities of organization end with the simplicity of spread-
into a state of disorder with a corresponding increase in out and slowly vibrating molecules? As has been said, nature
entropy. This means that all the available energy of the uni- is full of symmetry—so why should the universe begin with a

verse is gradually diminishing, and over time, the universe bang and end with a whisper?

4-23 CHAPTER 4 Heat and Temperature 107