Today, we meet a man who reinvented Archimedes'
pump. 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.
Now and then I run into a
student who says, "I like engineering just fine;
but why should I hafta take philosophy?" He fails
to see that what we do is shaped by the way we
think about things -- that our technology and our
philosophy bend to fit each other. Here's an
example:
Archimedes invented a really clever pump in the
third century BC. It's been used all over the world
ever since. It looks like a tube coiled around a
long axle. You tilt the axle and put its lower end
in water. Then you turn it. The open end of the
tube picks up water, and, as the coil turns, water
passes from one loop to the next until it comes out
at the upper end.
It's a pretty subtle gadget -- not the sort of
thing you just stumble across. Archimedean pumps
were widespread in the Classical world, and Roman
authors described them. Well, they tried to. We've
just seen that they aren't easy to describe.
Archimedes' pump didn't do so well during the High
Middle Ages, when European attitudes were strongly
shaped by Aristotle's philosophy. Aristotle very
clearly separated motion into two kinds -- motion
in a straight line and rotary motion. These pumps
mixed the motions. They used rotation to move water
upward along an axis. They were anti-Aristotelian,
and they were hard to find during the Renaissance.
Now in 1565 a Renaissance agricultural engineer
named Giuseppe Ceredi patented an Archimedes pump.
He systematically described the installation and
use of batteries of these pumps for both irrigation
and drainage. But we wonder how he could be given a
patent for a known device.
When you compare Ceredi's dimensioned drawings,
flow calculations, and economic analysis with the
almost unreadable Roman descriptions, you begin to
see why. Ceredi might well have found the idea in
the old literature; but he put flesh and blood on
it. After Ceredi's work, these pumps were quickly
accepted across southern Europe. They were not, as
one author puts it, "something that would be
created spontaneously by peasants." And they
certainly weren't something that people would take
up naturally in a world that didn't want to mix
straight-line and rotary motion.
Ceredi had a right-brain ability to visualize. He
had a left-brain ability to execute and organize
detail. But he was also able to break the
strait-jacket of Aristotelian thinking. A few years
later, Galileo took up full-scale combat with
Aristotelian ideas of motion. And Ceredi's
reinvention of Archimedes' pump was a harbinger of
that philosophical revolution.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
From an article in Humana Civilitas: Sources and
Studies Relating to the Middle Ages and the
Renaissance, Vol. I, On Pre-Modern Technology
and Science. (B.S. Hall, D.C. West, eds.)
Malibu: Undena Publications, 1976.
I am grateful to Pat Bozeman, Head of Special
Collections, UH Library, for drawing my attention
to this source and making her uncatalogued copy
available to me.
This episode has been greatly revised as Episode 1543.
From the 1832 Edinburgh
Encyclopaedia
Spiral of Archimedes, or Archimedean pump
The Engines of Our Ingenuity is
Copyright © 1988-1997 by John H.
Lienhard.
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