Today, two 20th-century thinkers look at the end of
an era. One sees it. One does not. 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.
In 1916 Henry Mercer
finished building a castle of cast concrete in
Doylestown, Pennsylvania. It was a museum to hold
his collection of old wagons, fireplace tongs,
spinning wheels, salt boxes. He'd collected all the
remains of a civilization that he realized was
about to vanish before his eyes. Today, Mercer's
museum houses a whole class of technologies that
had been unchanged for centuries in 1900 and were
gone forever a few years later.
We get quite another slant on the same story when
we look at a hydraulics text by Edward Bowser, who
once taught civil engineering at Rutgers. Bowser
published the book in 1885, twelve years before
Mercer began building his museum. The last edition
came out in 1921, five years after the museum
opened.
The book offers a nice calculus-based course. It's
hardly the cookbook instruction that too many
engineers got a century ago. It reads like a
medieval text in logic. Propositions are set in
italics. They're followed by corollaries and
scholiums.
Bowser provides hundreds of examples -- from the
trajectories of water jets to the stability of
ships. But then, tucked away among the examples, we
see the same thing Mercer saw.
Medieval machines keep popping up, all through the
book. Bowser shows how to calibrate a medieval
water clock. He calculates the performance of a
flap valve pump -- the kind sailors began using to
pump bilge water from sailing vessels just after
Columbus.
But the real surprise is a long section on every
kind of water wheel -- undershot, overshot. Water
wheels were the power source that took medieval
Europe out of the Dark Ages. By the time Mozart was
a kid, engineers were finally figuring out how to
analyze them. When Bowser was born in 1845, modern
water turbines were suddenly starting to put water
wheels out of business. By the time his 1921
edition came out, a water wheel was as out of place
on its pages as an oar-driven ship would've been.
So the transition that Mercer saw coming was the
web that snared Bowser. Perhaps it helped that
Mercer was trained as an anthropologist. He was
able to see that technology was about to leave its
medieval past behind -- suddenly, abruptly, and
without a backward glance.
But Bowser's book sits there, with one foot in
industrial America and the other in King Arthur's
court. He was stuck in the same time warp that
separates us by a thousand years -- from the
technology of only a century ago.
I'm John Lienhard at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
Bowser, E. A., An Elementary Treatise on
Hydromechanics, 7th edition. New York: D. van
Nostrand Co., 1921. (Bowser was born in 1845 and died
in 1910 -- 11 years before this last edition came
out.)
Allen, F., The Tower of Tools. American
Heritage of Invention and Technology,
Spring/Summer 1989, pp. 26-31.
For more on Mercer and Mercer's Museum, see
Episode 271 and Episode 1205. I am grateful to
Pat Bozeman, Head of Special Collections, UH
Library, for spotting the Bowser book and making it
available to me.
See also the following website:
http://en.wikipedia.org/wiki/Henry_Mercer
From An Elementary Treatise
on Hydrodynamics,1921. Image courtesy of
Special Collections, UH Library.
Bowser's schematic diagram of an overshot water
wheel
The Engines of Our Ingenuity is
Copyright © 1988-1997 by John H.
Lienhard.
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