Today, Mrs. B gives me a lesson in good teaching.
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.
Jane Haldimand was born in
1769, the daughter of a wealthy London merchant. We
know little of her early life. She married a Swiss
doctor, Alexander Marcet, when she was thirty. He
was a fairly distinguished professor of medicine --
on his way to becoming quite wealthy. But Jane
Jane Marcet, was not one for a gilded cage.
Soon after her marriage, she began writing
instructive books for young people.
The title of her first book was Conversations
on Chemistry, intended more especially for
the female sex. It came out in 1806. The style is
arresting. It's a running conversation between a
Mrs. B and two young ladies, Caroline and Emily.
Listen as they talk about heat radiation. Mrs. B
Before I conclude the subject ... I must observe
that different surfaces [radiate heat] in different
Emily asks, "These surfaces [are all] the same
temperature?" Mrs. B answers, "Undoubtedly. I will
show you [an] ingenious apparatus." She produces a
cubical tin. One side is sanded, one rusted, one
covered with soot, one polished.
She fills the tin with hot water. Then she uses a
focusing mirror to reflect the heat from each side
onto a thermometer. She gets four different
readings. I'm going to recommend that experiment
for our thermal lab at the university.
Within a gentle parlor propriety, Mrs. Marcet and
her alter ego, Mrs. B, boldly take on
any subject. They talk about Watt's new steam
engine -- its valving and power takeoff mechanism.
Of course, the appeal of that kind of material
wasn't limited to young women. My American edition
belonged to someone named Charles Smith, who lived
in Baltimore in 1835. He's made marginal notes
about lime water and about the solubility of tree
After this book, Marcet wrote on political economy,
geology, and much more. Her book on political
economy was very popular. It sold over 160,000
copies in America alone.
A crinoline wall separated women and men
intellectually in 1800. Jane Marcet lived behind
that wall. Yet her books marched out into the
middle of the 19th century and helped transform it.
The year she wrote her book on chemistry, a
15-year-old boy worked in a London bookbindery. He
Michael Faraday. When Marcet's book passed
through, he read it. It transformed him. Faraday
went on to create our modern concepts of
The crowning irony is on page 105 in the 1833
edition of her chemistry book. On page 105 the
editor has added a version of the experiment in
which Faraday anticipated the electric motor.
Already the book bears the fruit of her first
edition. And Mrs. Marcet has given me -- a new role
model for my teaching.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
My biographical sources were the Dictionary of
National Biography articles on Jane and
Alexander Marcet and her uncle, Frederick Haldimand.
He was a hero of our French and Indian War.
Jones, T.P., New Conversations on
Chemistry... Philadelphia: John Grigg, 1833.
(This is an updating of Marcet's original book,
which was published in 1806. I couldn't lay my
hands on a copy of the original.)
Marcet, J. Conversations on Political
Economy ... , 5th ed. London: Longman etc.,
Marcet, J., The History of Africa ...
London: H. Colburn and R. Bentley, 1830.
Williams, L.P., Faraday, Michael. Dictionary
of Scientific Biography (C.C. Gilespie,
ed.). Charles Scribner's Sons, 1970-1980.
In modern terms, Mrs. B's radiation experiment
showed how the the radiant emittance of each side
of the tin is different. As that property varies,
so does the heat emitted from each side. The sooty
side emits about 95 percent of a theoretical
maximum. The polished side probably emits less than
5 percent. (For more on light and heat radiation, see: J. H. Lienhard IV and J. H. Lienhard V, A Heat Transfer Textbook, 5th ed., Dover Pubs. Inc., Mineola, NY, 2019. You can easily download the entire book, free of charge, at https://ahtt.mit.edu/ , Table 11.1, Chapter 10.)
Jane Marcet died in 1858 at the age of 89. By then,
she'd strongly influenced her good friend, the
famous English author Harriet Martineau. Martineau
began by writing her own version of Marcet's
Political Economy. She went on to
become a powerful advocate of religious liberalism
and the abolition of slavery.
For more on Marcet, see Episodes 741, 745,
828, 900, and 950.
The Engines of Our Ingenuity is
Copyright © 1988-1997 by John H.
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