Today, Joseph Fourier. The University of Houston's
College of Engineering presents this series about
the machines that make our civilization run, and
the people whose ingenuity created them.

The eighteenth century
radiated a peculiar kind of genius. It gave us
people like Mozart, Jefferson, Euler, and Ben
Franklin. Isaac Newton led us *into* the
astonishing eighteenth century. And Joseph Fourier
might well have been the last of those greats.

If you've studied math, heat flow, or acoustics,
you've heard of Fourier. He was born in France in
1768. Orphaned at nine, he never-theless gained an
education in math and military engineering. Then he
walked a slippery path through the politics of the
French Revolution. He was jailed twice along the
way.

As the dust cleared, Fourier joined the faculty of
France's new École Polytechnique for
two-and-a-half years. He was then drafted into
foreign service and sent off on a ship to a secret
posting with Napoleon Bonaparte. It turned out he
was to be part of Napoleon's Egypt campaign -- the
Secretary of a so-called Cairo Institute, charged
with answering a vast array of Egypt-related
scientific and technical questions.

Napoleon abandoned his army in Egypt, returned to
Paris, staged a coup, and claimed the leadership of
France. He was already beginning his European
conquests while his Egypt forces were collapsing.
When they returned in defeat, Napoleon made Fourier
the Prefect of Isère -- kind of like an
American state governor.

Fourier went to work with astonishing energy. He
built roads and engineered a land-drainage program.
He also wrote papers on mechanics. He wrote a book
on Egypt. Meanwhile Napoleon's reign collapsed, and
he was exiled to Elba. When Napoleon tried to
return to power, Fourier fled. He'd had enough
entanglement. Some people are more dangerous as
friends than as enemies.

Fourier had started thinking heat flow long before,
back in Egypt. In Isère, he'd submitted a
study on the analytical theory of heat to the
Academy of Science. He showed how to describe heat
flow in solid bodies, but he did much more. He
created a whole new form of applied mathematics.
Using it, we'd now be able to solve problems that
previously seemed far out of reach.

Like any masterpiece, the paper broke rules.
Fourier's intuition led him where logic had a hard
time following. The work offended many great
mathematicians and, for fifteen years, he fought to
get it published. When it came out until 1822, it
was a full book -- the most important mathematical
work of that age.

Napoleon was now long gone, but Egypt lingered.
That's where Fourier's lifelong obsession had begun
-- an obsession with heat, with its healing powers,
and with its mathematical treatment. Fourier never
married. But, among his close friends was the first
great female applied mathematician, Sophie Germain. They corresponded
for years and died only nine months apart.

But Fourier, having succeeded in altering the very
character of both engineering and mathematics,
spent his last days swathed, mummy-like in warm
clothing, in his overheated Paris apartment.

I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.

(Theme music)

J. Fourier, *The Analytical Theory of Heat*
(transl. by A. Freeman). New York: Dover
Publications, Inc., 1955.
I. Gratton-Guiness, *Joseph Fourier
1768-1830* (With J. R. Ravetz). Cambridge: MIT
Press, 1979.

*Joseph Fourier Savant et Préfet
1768-1830,* Grenoble: Bibliotheques
Munici-pales, 1989. (no author given)

For some application of Fourier's work to heat
transfer, see J. H. Lienhard IV and J. H. Lienhard V, *A Heat Transfer Textbook*. 3rd
ed., Cambridge, MA: Phlogiston Press, 2004, **Click here for a free copy.**

This is a greatly revised version of Episode 186.

Jean Baptiste Joseph Fourier, 1768-1830

Click on the image for an
enlargement.

Napoleon shown contemplating the Sphinx (1895
*Century Magazine*).

The Engines of Our Ingenuity is
Copyright © 1988-2003 by John H.
Lienhard.