Today, a skill eliminates itself. 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.
I found this dusty wordless book in
our library -- not one word! The title, in fine Victorian
print, says Descriptive Geometry: Plates. It
holds a hundred and thirty two carefully worked exercises
in mechanical drawing, nothing more. It was the companion
of a long forgotten textbook. It shows how to draw
perspective views of intersecting arched hallways -- how
to lay out the sheet-metal pattern of the skewed frustum of a skewed
cone.
In 1931, West Point cadet Harold Hughes signed this copy.
Yet the book had been in print since the Civil War. It
displayed constructions first devised by the great
renaissance artist Albrecht
Dürer. In the intervening half millennium, good
drafting books (like this one) have often had that kind
of staying-power.
If you're an older engineer, there's a good chance you
learned drafting from a book by Thomas French. It came
out in 1911. French died in 1944, and revisions of his
book are still in print. But the subject has migrated
from paper into our computers. If French came back today,
he wouldn't recognize his fourteenth edition.
Last week, a colleague gave me a 1904 text by a Tufts
professor. This one stayed in use over twenty years --
until French's book replaced it. It's shorter, but the
whole story is there. Here's the same lost tactile world
of drafting that I entered in 1946. First, the tools:
T-square, triangles, a scale (which is never to be called
a ruler), 4H and 6H Siberian-lead pencils and sandpaper
to sharpen them, a set of French curves, and thumb tacks
(the 3-M Company has yet to invent masking tape.) We also
have to invest in a case of instruments -- compasses,
dividers, ruling pens -- and in a bottle of India ink.
Next, we relearn lettering. A proper draftsman leaves the
cursive script of public schools behind forever. We learn
to draw a straight line in pencil, and ink it in with
thin lines or thick ones.
But all this is prelude. Now we learn to reduce vision to
a vocabulary of lines -- solid lines that we can see with
our eyes, hidden lines that we can see only in our mind.
We learn to turn objects about in space, but to do it on
two-dimensional paper.
These old books leave me with an aching sense of lost
beauty. I still have my old tools, but the computer has
grown too large. The old drawing skills shrink before it.
In 1952, when I taught advanced drafting to newly hired
engineers at Boeing, new technologies were already
hinting at the end of an era.
Now I hold these old books -- written before the
computer, even before Thomas French. If you focus upon
their brief contents, you too can do what Albrecht
Dürer did: Stand at the drafting board and watch
ideas flow from under your ink-stained fingers. You too
can own space and bring forth machines. But watch out!
Once you do, you will create a computer-driven,
electronically lit world, where these old skills can no
longer have any place.
I'm John Lienhard, at the University of Houston, where
we're interested in the way inventive minds work.
(Theme music)
Church, A. E., Plates to Descriptive Geometry: Shades,
Shadows and Linear Perspective. New York American Book
Company, 1864/1892
French, T. E., and Ives, F. W., Agricultural Drawing
and the Design of Farm Structures. New York:
McGraw-Hill Book Company, Inc., 1915.
French, T. E., A Manual of Engineering Drawing for
Students and Draftsmen. 4th ed., McGraw-Hill Book
Co., Inc., 1911, 1918, 1924, 1929. (This is the edition
on my desk. Amazon.com is presently (2001) showing the
fourteenth edition for sale. My fourth edition indicates
that 308,000 copies had been sold by 1929.)
Anthony, G. C., Elements of Mechanical Drawing: The
Use of Instruments; Theory of Projections and its
Application to Practice; and Numerous Problems Involving
both Theory and Practice. Boston: D. C. Heath &
Co., Publishers, 1894/1904. (I am grateful to Joseph
Davidson, Language and Culture Center, UH, for this
edition of the Anthony book.)
The Engines of Our Ingenuity is Copyright
© 1988-2001 by John H. Lienhard.
