Today, eccentric circular turning. 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.
Henry Bessemer received a patent for his
new steel-making process in 1855. But the
nineteenth century invented Bessemer as much as the
other away around. For this was the age of
steel. And, along with the hugely expanded use of
steel came new means for shaping and machining it.
Consider, say, a problem connected with planing a
piece of steel to a desired thickness. The cutting
stroke needs enormous force and it must be done
slowly. But you want to return the cutter for the
next stroke as quickly as possible. All kinds of
quick-return mechanisms appeared. A steadily
turning crankshaft might drive a cam or eccentric
gear. During
one cycle the cutter moves slowly in one direction
and rapidly in the other.
The latter nineteenth century offered vast
literature on the elaborate mechanisms that made up
heavy machines. And nonsymmetrical, or
eccentric, action was at the heart of it.
Now a colleague has shown me an old book by John
Ibbetson, titled, Eccentric Circular
Turning. This book went through many editions
and printings between 1817 and 1851 -- all long
before Bessemer and big steel.
Ibbetson's family had been lathe-makers in the
eighteenth century, and John Ibbetson had developed
a new eccentric chuck. It drove a cutting tool
through preset sequences of cuts, each a bit
different from the last, until it returned to a
starting point.
And he was no doodler, working in isolation. He
cited previous work by the French, and based his
work on that of the German, Holtzapffel. If you
know this kind of mechanical decoration, you've
heard Holtzapffel's name. He was its major
developer, although you find antecedents all the
way back to sixteenth-century Bavaria.
However, Ibbetson so catches my eye because his
book on deco-rative art has the look and feel of
Bessemer's world. He calls to my mind the artist
and designer of steam forges James Nasmyth. Nasmyth invented
the heavy steel forges of the mid-nineteenth
century, but he's also known for his lovely
paintings of those forges.
Reading Ibbetson we catch the same seamless
symbiosis. He sees no line between decorative art
and machinery. His machine itself is art,
as much as the pattern it produces. And we gain a
clearer picture of the forces behind the new
industrial world.
The driving force was then -- as it has always been
-- more aesthetic than utilitarian. But then,
invention has always been impelled by the magnetic
attraction of beauty, in its many forms.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
J. H. Ibbetson, Specimens in Eccentric Circular
Turning with Practical Instructions for Producing
Corresponding Pieces in the Art. 3rd ed.,
London: Longman, Ormé, Brown, Green and
Longman, [Probably 1838, although new 3rd editions
kept coming out until 1851.] All images on this page
are from this source.
I am grateful to Bobby Marlin, UH Library Archives,
for suggesting the topic, and for generously
providing material from Ibbetson's book.
Click here formore on the Ibbetson family.m
For a twentieth-century look at mechanisms, see the
treatise: Ingenious Mechanisms for Designers
and Inventors. (Franklin D. Jones, ed.) Vol.
I-IV, New York: Industrial Press Inc., 1968. My
thanks to Lewis Wheeler, UH Mechanical Department
for this fine set.
The output was an
elaborate and quite lovely decorative carving. These
carvings took forms that might resemble snowflakes,
or maybe fancy tile-work. Today,